WO1999003577A1

WO1999003577A1 - Absorbent composition, process for producing the same, and absorbent article

Info

Publication number: WO1999003577A1
Application number: PCT/JP1998/003231
Authority: WO
Inventors: Hitoshi Takai; Tsuyoshi Yuki; Shingo Mukaida; Daisuke Tagawa; Kenji Tanaka
Original assignee: Sanyo Chemical Industries, Ltd.
Priority date: 1997-07-18
Filing date: 1998-07-17
Publication date: 1999-01-28
Also published as: AU8244098A; AU739387B2; DE19882553T1

Abstract

An absorbent composition having a structure comprising a water-absorbing resin (A) and a fine filler (B) contained therein, characterized by having a specific surface area larger by at least 10 % than that of the water-absorbing resin (A) not containing the fine filler (B); and a process for producing the absorbent composition involving the step of drying a polymer in an aqueous gel form to produce a water-absorbing resin (A), after a fine filler (B1) having a true density of 0.1 g/cm3 or lower and a particle diameter of 1 to 200 νm is incorporated into the polymer.

Description

Detail

Absorbent composition, method for producing the same, and absorbent article

The present invention relates to an absorbent composition, a method for producing the same, and an absorbent article.

In particular, an absorbent composition in which a microfilament is incorporated in a water-absorbent resin to improve the surface area and the absorption rate associated therewith; an absorbent composition in which the absorption rate to blood and the water retention are further improved; These production methods; and absorbent articles using these compositions. Background art

The absorption rate of the water-absorbing resin is influenced by its surface area. That is, in the case of the particulate water-absorbing resin having a constant mass, the larger the particle size of the particles, the smaller the surface area and the smaller the area in contact with water. Conversely, as the particle size becomes smaller, the surface くなる becomes larger, so that the absorption rate becomes faster. However, if the particle size is too small, when the water-absorbent resin comes into contact with water, a phenomenon occurs in which the fine particles associate with each other via water (a phenomenon called “mamako”). Speed slows down.

Conventionally, the following methods (1) to (4) have been proposed as methods for improving the absorption rate of a water-absorbing resin.

(1) Add surfactant and water-soluble polymer to the surface of fine particulate water-absorbent resin

How to prevent "mamako" (Japanese Patent Publication No. 2-303036);

(2) A method in which a low boiling point volatile solvent is added to the polymerization stock solution in the process of producing a water-absorbent resin, and the volatile solvent is vaporized by the heat of polymerization to make the resin porous. No. 7 1 2);

(3) A method in which a crosslinking agent and a pyrolytic foaming agent are mixed with a carboxyl S-containing water-absorbent resin and a glycidyl group-containing polyolefin resin, and the mixture is heated to form a foam. No. 37);

(4) A method of obtaining a porous water-absorbent resin by dispersing and polymerizing a foaming agent comprising an amino-containing azo compound in a monomer aqueous solution containing an unsaturated monomer and a crosslinking agent (Republished Patent W No. 0 9 6-1 7 8 8 4);

方法 A method of granulating fine particles using water or a heat-fusible resin binder.

However, the methods (1) to (4) show that, when the liquid to be absorbed is a low-viscosity liquid such as urine or salt water, a certain effect of improving the flute is recognized, but the manufacturing and quality aspects are as follows. It was not always satisfactory.

Since the water-absorbent resin obtained by the method (1) has too fine particles, when it is mixed with fibrous materials such as pulp to be used as an absorbent and applied to paper diapers etc., it is said that the fine particles will be released from the fibrous materials. There's a problem. Furthermore, the water-absorbent resin obtained by the method ① is treated with a surfactant or a water-soluble polymer, so that the powder fluidity deteriorates and fine particles cause dust generation. May cause environmental degradation problems.

In the method of making porous, the improvement of absorption rate is recognized to some extent, but special manufacturing equipment such as explosion-proof type is required because a low boiling point volatile solvent is used.

In the method using a thermal decomposition type blowing agent in (3), since the raw water-absorbent resin and polyolefin resin are hard and inflexible resins, the gas must be released at once when the gas pressure reaches a certain level. Therefore, there is a problem that the foam diameter is large and the cells become non-uniform, and it is difficult to obtain a constant absorption rate and absorption performance.

In the method of making porous, the amino group-containing azo compound is decomposed to generate nitrogen gas, and at the same time, radicals are generated. Therefore, the absorption performance is reduced due to a decrease in the molecular weight of the water-absorbing resin, and water-soluble components are not used. The problem arises of the increase of.

In the method of granulating the fine particles with a binder, the effect of improving the absorption rate becomes insufficient if the bond strength of the binder is increased. Conversely, if the adhesive force of the binder is weakened, the mechanical strength of the granulated material is weakened, and the granulation is broken by mechanical shear and mechanical friction in the powder feeder and the powder transfer process by wind pressure. This causes a problem of returning to the original fine particles.

In addition, when blood is used as the liquid to be absorbed, the blood is highly viscous and contains high molecular organic components such as blood cells, hemoglobin, cytoplasm, and protein components. Did not give good results.

Satisfies both the absorption capacity for water and the water retention and absorption rate, In fact, the emergence of a water-absorbent resin suitable for blood-absorbing articles such as kin is strongly desired. Conventionally, the following methods (1) to (3) have been proposed as methods for improving the absorption characteristics of the water-absorbent resin for blood.

(4) A method of adding a salt of an inorganic acid or an organic acid to a water-absorbing resin (Japanese Patent Application Laid-Open No. 58-501107);

(4) A method in which a part of the neutralized salt of the water-absorbing resin is converted to lithium or lithium salt (Japanese Patent Publication No. 6-255543);

(4) A method in which an aqueous solution of a polyamino acid (salt) is added to a water-absorbent resin and mixed, or a water-soluble unsaturated monomer is polymerized in the presence of a polyamino acid (salt) and a cross-linking agent. No. 10021).

However, although the method (1) can improve the blood absorption rate to some extent, it has a drawback that the absorption capacity and the water retention are reduced because a large amount of salts of inorganic or organic acids must be added.

In the method (1), although the absorption capacity for the blood coat is improved to some extent, the absorption rate of blood is not always a satisfactory level.

In the method (1), although the absorption performance with respect to physiological saline is excellent, the absorption capacity with respect to blood is as low as 6 to 11 times, and the absorption rate is not always at a satisfactory level.

A first object of the present invention is to provide an absorbent composition comprising a water-absorbent resin having an improved surface area and an accompanying improved absorption rate.

A second object of the present invention is to provide an absorbent composition in which the problems in the above methods (1) to (4) have been improved.

A third object of the present invention is to provide an absorbent composition having improved absorption capacity for blood and improved water retention and absorption speed.

A fourth object of the present invention is to provide an absorbent article using such an absorbent composition. Disclosure of the invention

The present invention relates to the following absorbent composition [1] [2]; a method for producing the absorbent composition [3; ~ [ Five ]; And absorbent articles [6].

[1] Absorbent composition

This is an absorbent composition with a structure in which the microfilament (B) is incorporated in the water-absorbent resin (A), and a comparison table with the water-absorbent resin (A) in which the microfilament (B) is not incorporated. An absorbent composition characterized in that the area is improved by 10% or more.

[2] absorbent composition

An absorbent composition according to the above [1], wherein the surface of the absorbent composition is further provided with a surfactant (C).

[3] Method for producing absorbent composition

Absorbent resin (A) and before the drying step to produce a hydrogel polymer Te絰, true density of less than 0. 1 g / cm ^a particle size of 1～200〃M micro filler (B1) This is a method for producing an absorbent composition in which is incorporated and dried.

[4] Method for producing absorbent composition

Before drying in the process of producing the water-absorbent resin (A) via the hydrogel polymer, a heat-expandable hollow filler (Β2 ') with a particle size of 1 to 15 O ^ m is built in and dried by heating. This is a method for producing an absorbent composition in which a fine filler (Β2) obtained by thermally expanding (Β2 ') is incorporated in a water-absorbent resin (Α).

[5] Method for producing absorbent composition

This is a method for producing an absorbent composition in which a surfactant (C) is further provided on the surface of the composition obtained by the production method according to [3] or [4].

[6] Absorbent articles

An absorbent article comprising the absorbent composition according to the above [1] or [2] and an absorbent layer comprising a fibrous material, which is wrapped in a surface protective sheet having a water-permeable portion. BEST MODE FOR CARRYING OUT THE INVENTION

[Specific examples of water absorbent resin (樹脂)]

Representative examples of the water-absorbent resin (II) in the absorbent composition [1] of the present invention include the following water-absorbent resins. Also, in addition to ①, the following water-absorbent resins ① to ④ can be exemplified. (1) One or more multifunctional compounds selected from the group consisting of a water-soluble or water-soluble radically polymerizable monomer (a), a crosslinking agent (bl) and a graft base (b2). (B) a water-absorbent resin obtained by polymerizing and, if necessary, hydrolyzing a water-insoluble water-swellable polymer having a crosslinked structure and / or a graft structure;

(2) The surface of a particulate polysaccharide is crosslinked to form a water-insoluble, water-swellable structure (for example, water-soluble polysaccharide such as guar gum, xanthan gum, cellulose, methylcellulose, ethylcellulose, carboxymethylcellulose, or a modified product thereof). Particles obtained by surface cross-linking using a polyfunctional cross-linking agent);

(3) In polymerizing a water-soluble radically polymerizable monomer, it is self-crosslinked to form a water-insoluble, water-swellable polymer (for example, a self-crosslinked polyacrylate);

(4) Water-soluble radically polymerizable monomers are polymerized and, if necessary, thermally cross-linked in the presence of a cross-linking agent to form a water-insoluble, water-swellable polymer (for example, acrylamide and acrylic acid. (Salt) And a copolymer obtained by heating the copolymer.

In the water-absorbent resin (1), the water-soluble radically polymerizable monomer (al) of the monomer (a) is, for example, a water-soluble monomer having an acid grave such as a carboxylic acid group, a sulfonic acid group, or a phosphate group. Water-soluble radical polymerizable monomer having all acid groups (all); nonionic water-soluble radical polymerizable monomer (al3); I can do it.

In (all), examples of the radically polymerizable water-soluble monomer having a carboxylic acid group include unsaturated mono- or polycarboxylic acids [(meth) acrylic acid (acrylic acid and / or methacrylic acid. Use the same description), crotonic acid, sorbic acid, maleic acid, itaconic acid, cinnamic acid, salts thereof, etc., and their anhydrides [non-maleic acid, etc.].

Among (all), examples of the radically polymerizable water-soluble monomer having a sulfonic acid group include fatty acids or aromatic vinylsulfonic acids (vinylsulfonic acid, arylsulfonic acid, vinyltoluenesulfonic acid, styrenesulfonic acid, etc.) , (Meth) acrylalkyl sulfonic acid, [(meth) acrylic acid sulphoethyl, (meth) acrylic acid sulphob pill), (meth) acrylamide alkyl sulfonic acid [2-acrylamide 2-methylpropanesulfone Acid and the like], and salts thereof. Of (all), the radically polymerizable water-soluble monomer having a phosphate group includes, for example, (meth) acrylic acid hydroxyalkyl phosphate monoester [2-hydroxyshethyl (meth) acryloyl phosphate, , Phenyl-2-ethylacryloxyethyl phosphate, etc.].

Examples of the kind of the salt in (a12) include an alkali metal salt, an ammonium salt, an amine salt and the like, and preferably an alkali metal salt, particularly a sodium salt.

Examples of the nonionic water-soluble radically polymerizable monomer (al3) include (meth) acrylamide, vinyl vinylidone, 2-hydroxyethyl (meth) acrylate, and the like.

Among the monomers (a), the radically polymerizable monomers (a 2) which become water-soluble by hydrolysis include (meth) acrylonitrile, (meth) acrylic acid lower alkyl esters (alkyl groups having a carbon number of 1 4), maleic acid lower alkyl esters (1 to 4 carbon atoms in the alkyl group), vinyl acetate, and the like.

As the monomer (a), two or more of those exemplified above may be used in combination. When the water-absorbent resin (A) is a resin having an acid group and / or a salt thereof, the degree of neutralization of the acid group in the resin is preferably 50 to 90 mol%, particularly preferably 60 to 80 mol%. Mol%. This neutralization may be performed at the stage of the monomer before the polymerization, or may be performed after the polymerization.

Examples of the crosslinking agent (b1) include a bridging agent having two or more ethylenic unsaturated groups (b11), a crosslinking agent having at least one ethylenically unsaturated group and at least one reactive functional group (b12), Crosslinking agents (bl3) having two or more reactive functional groups are exemplified.

Specific examples of the cross-linking agent (b ll) include N, N, -methylenebis (meth) acrylate, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, and glycerol. Examples include phosphorus (di or tri) acrylate, trimethylpropane triacrylate, triallylamine, triallyl cyanurate, triallyl cisyanurate, tetraaryloxyphene, and pentaerythritol triallyl ether.

Specific examples of the crosslinking agent (bl2) include glycidyl (meth) acrylate, N-meth (Meth) acrylamide.

Specific examples of the crosslinking agent (bl3) include ethylene glycol, diethylene glycol, glycerin, propylene glycol, diethanolamine, trimethyl propylpropane, polyethyleneimine, ethylene glycol diglycidyl ether, and 'glycerol diglycidyl. Ether and polyglyceryl polyglycidyl ether.

Two or more of these crosslinking agents may be used in combination. Of these, preferred are crosslinking agents (b11), and particularly preferred are N, N'-methylenebisacrylamide, ethyleneglycoldiacrylate, trimethylolpropanetriacrylate, and tetraaryloxy. , Pentaerythritol triallyl ether and triarylamine.

Examples of the graft base (b2) include water-soluble polysaccharides such as starch, guar gum, xanthan gum, cellulose, methylcellulose, ethylcellulose, cellulose dimethylcellulose, and modified products thereof, polyvinyl alcohol, and polyester resins. And the like.

This water-absorbent resin (A) forms at least one multifunctional compound (b) selected from the group consisting of a crosslinking agent (bl) and a graft base (b2) in order to form a crosslinked structure and / or a graft structure. ) Is used.

The amount of the agent used for forming the crosslinked structure is usually 0.0015% based on the total mass of the monomer (a) and the agent (bl), and is preferably 0.001%. , 0.05 to 2%, more preferably 0.1 to 1%.

If the amount of the cross-linking agent (bl) is less than 0.001%, it becomes a sol when absorbing water, the water absorbing ability, which is a function of the water-absorbing resin, is reduced, and when it comes into contact with the aqueous liquid, And the apparent absorption rate is reduced. Also, the drying property is very poor and the productivity is inefficient. On the other hand, if it exceeds 5%, on the other hand, the crosslinking becomes too strong and does not exhibit sufficient water absorption / water retention capacity.

The amount of the graft base (b2) used for forming the graft structure does not usually exceed 30 based on the total mass of the monomer, the crosslinking agent (bl) and the graft base (b2). Amount, preferably 0.1 to 20% by mass, more preferably 1 to 10% by mass. % By mass.

Specific examples of the water-absorbing resin (1) include a saponified starch-acrylonitrile copolymer, a cross-linked starch-acrylate copolymer, a cross-linked polyacrylate, and (meth) acrylic acid. Saponified product of crosslinked ester monovinyl acetate copolymer, crosslinked product of isobutylene / maleic anhydride copolymer, crosslinked product of polysulfonate, polyacrylate salt, crosslinked product of polysulfonate copolymer, polyacrylic acid / poly Examples include crosslinked acrylamide copolymers, crosslinked polyacrylamides and hydrolysates thereof, crosslinked polyvinyl vinylidone, and crosslinked cellulose derivatives.

Preferred as the water-absorbing resin (A) are those which can absorb and hold a large amount of liquid due to ionic osmotic pressure, and have a salt of a carboxyl group and / or a lipoxyl group with little water separation even when a load or external force is applied. It is a water-absorbing resin containing a polymerizable monomer as a main component, and more preferably a crosslinked product of a starch-acrylate copolymer and a crosslinked product of a polyacrylate.

In the specific examples of the water-absorbent resin (A) as well, in the case of the neutralized salt form, the salt type and the degree of neutralization are preferably alkali metal salts, more preferably sodium salts and potassium salts. The degree of neutralization with respect to the acid groups is preferably 50 to 90 mol%, more preferably 60 to 80 mol%.

In order to obtain the water-absorbing resin (1), various additives, chain transfer agents (for example, thiol compounds, etc.) and surfactants are added to the polymerization system for polymerizing the monomer (a) and the polyfunctional compound (b) as necessary. It cannot be added even if an agent is added.

The polymerization method for producing the water-absorbent resin (A) is not particularly limited, and examples thereof include an aqueous solution polymerization method, an opaque polymerization method, a reversed-phase turbidity polymerization method, a spray S synthesis method, a photopolymerization method, and a radiation polymerization method. . A preferred polymerization method is a method of performing aqueous solution polymerization using a radical polymerization initiator. In this case, the type of radical polymerization initiator and the radical polymerization conditions are not particularly limited, and may be as usual.

[Specific examples of micro filler (B)]

The absorbent composition [1] of the present invention is an absorbent composition having a structure in which a fine filler (B) is incorporated in a water-absorbent resin (A). θ

Examples of the fine filler (Β) include a fine filler (B1) having a true density of 0.1 lg / cm ³ or less and a particle size of 1 to 20 O / m and a heat filler having a particle size of 1 to 150 / m. One example is a small filler (なる 2) formed by thermally expanding an expandable hollow filler (Β2 '). Both the small filler (B1) and the small filler (Β2) are water-absorbent resin (Α) in any ratio. It may be built inside.

The true density of the micro filler (B1) usually 0. lg / cm ³ or less, preferably 0. 0 8 g / cm ^a, particularly preferably ^{0. 01~0 · 06 g / cm 3} .

When the true density of (B) is greater than 0.1 g / cm ³ , the effect of improving the absorption rate of the obtained absorbent composition is poor because the increase in volume and the increase in surface area of the absorbent composition are small.

True density is a value measured by, for example, ACCUPYC 1330 PYCNOMETER. An example of a specific measurement operation is as follows.

PYCNOMETER has two chambers (chambers) connected by pulp, cell chamber and expansion chamber, and their volumes are indicated by V (c) and V (e). In the cell chamber, remove the sample material g (W) (the volume of this sample is V), close the valve connected to the expansion chamber, and fix the pressure in the cell chamber to P (1). The pressure of the expansion chamber at that time is P (a). Then, the pulp connected to the expansion chamber is sealed, and the pressure P (2) distributed to both chambers is measured. The sample volume is obtained from the volume and pressure of each chamber before and after opening the pulp, and the true density is calculated by the following equation.

True density = W + V = W ÷ [V (c V (e) x {P (a) -P (2) {P (l) -P (2)}]

The particle size of (B1) is usually 1 to 200 m, preferably 1 to 50 m, and more preferably 5 to 100 m. When the particle size of (B) is larger than 200, the uniformity of blending (B) with the hydrogel of (A) in the production method [3] of the present invention is poor, and the resulting absorbent composition is obtained. This is not preferred because the effect of improving the absorption rate of the water may be poor. On the other hand, when it is smaller than 1 m, when (B1) is mixed with the hydrogel of (A), aggregation of the (B1) is likely to occur, resulting in poor uniformity.

The material of (B1) is not particularly limited, and may be either organic or inorganic. Examples of organic materials include polyethylene, polypropylene, polystyrene, and polystyrene. L-xylylene, polyacrylate, polymethacrylate, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, fluororesin, polyacrylonitrile, polyvinyl ether, polybutadiene, polyamide, thermoplastic polyester, polycarbonate, polyphenylene oxide, polysulfone, Examples include thermoplastic polyurethane, polyethylene oxide, polypropylene oxide, polytetramethylene oxide, polyacetal, and cellulose derivatives. Those obtained by copolymerizing two or more monomers constituting these resins are also included.

Examples of inorganic materials include silicon oxide, aluminum oxide, iron oxide, titanium oxide, magnesium oxide, zirconium oxide, and the like.

These may be used in combination of two or more. Of these, preferred are organic materials, and more preferred are polyacrylate, polymethacrylate, polyvinylidene chloride, polyacetate biel, and polyacrylonitrile.

The shape of (B1) is not particularly limited, hollow, ₆ favored correct shape such as porous and the like are hollow.

Specific examples of the fine filler (B1) in the present invention include, for example, Matsumoto Microsphere F—50E manufactured by Matsumoto Yushi Co., Ltd., and Expanscel 551 DE and 46 manufactured by Nippon Ferrite Co., Ltd. 1 DE, 09 I DE, etc. These may be used in combination of two or more.

On the other hand, in the absorbent composition having a structure in which the fine filler (B2) is embedded in the water-absorbent resin (A), (B2) is a thermally expandable hollow filler (B2 ') having a particle size of 1 to 15 mm2. Is a minute filler that is thermally expanded.

Examples of the heat-expandable hollow filler (Β2 ′) include a fine hollow resin containing a gas or a volatile compound in a void.

Examples of the type of resin that forms the outer wall in this minute hollow resin include polyethylene, polypropylene, polystyrene, poly-xylylene, polyacrylate, polymethacrylate, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, and polyvinyl acetate. Resin, polyacrylonitrile, polyvinyl ether, polybutadiene, polyamide, thermoplastic polyester, polyacrylonitrile, polyphenylene oxide, polysulfone, thermoplastic polyurethane, polyethylene oxide, polyp W 99

11

Examples thereof include lenoxide, polytetramethylene glycol, polyacetal, and the like, and examples include those obtained by copolymerizing two or more monomers constituting these resins. These may be used in combination of two or more.

Among these resin types, preferred are polyacrylate, polyvinylidene chloride, and polyacrylonitrile.

The expansion start temperature of (Β2 ') can be variously changed depending on the softening temperature of the resin forming the outer wall, the type of gas present in the voids, and the type of the volatile compound, but is preferably 60 to 1 50 ° C., while the maximum expansion temperature is preferably 80-180. C. More preferably, the expansion start temperature is 70 to 120. C, the maximum expansion temperature is 90 ~ 150.

When the expansion start temperature is lower than 60 ° C., in the production method of the present invention, it may be necessary to cool the hydrogel, which is inefficient. On the other hand, when the expansion start temperature is higher than 150 ° C., in the production method [4] of the present invention, in the heating and drying step, the evaporation of the water in the hydrogel state (A) precedes. When the swelling starts, the swelling efficiency may decrease because the flexibility of the hydrogel may be reduced.

When the maximum expansion temperature is less than 80 ° C. or more than 18 (TC), the same phenomenon as described above may occur, which is not preferable.

As an example of the gas or the volatile compound contained in the hollow space of (部 2 ′), the boiling point at normal pressure is 150. It is a compound having a boiling point of not more than C, preferably not more than 120 ° C, more preferably not more than 100 ° C. Boiling point is 150. If it is larger than C, in the production method of the present invention, the thermal expansion start temperature of (B 2) becomes high, and heat treatment must be performed at a high temperature, which is inefficient. Further, the thermal expansion may be insufficient, and the effect of improving the absorption rate of the obtained absorbent composition may be poor.

Examples of the gas or volatile compound contained in the voids of (Β 2 ') include isoptan, isopentane, petroleum ether, η-butane, η-pentane, n-^^ xane, cyclopentane, and cyclohexane. Trifluoromethane, dichlorofluoromethane, butylene, methylene chloride and the like. These may be used in combination of two or more.

Preferred are isobutane, isopentane, n-butane, n-pentane, petroleum It is ether.

The particle size of (Β2 ′) is not particularly limited, but is usually 1 to 150 μπι, preferably 1 to 100 / zm or less. When the particle size of (2,) is larger than 150 m or smaller than 1 m, in the production method [4] of the present invention, the uniformity of blending of (Β2 ') into the hydrogel of (A) is improved. And the effect of improving the absorption rate of the obtained absorbent composition may be poor, which is not preferable.

The volume expansion ratio of (Β2 ′) is preferably 1 ° or more, particularly preferably 30 times or more. If the volume expansion ratio of (Β2 ′) is less than 10, the expansion rate of (Α) is low, and the effect of improving the absorption rate of the obtained absorbent composition may be poor.

Specific examples of the heat-expandable hollow filler (Β2 ′) in the present invention include Matsumoto Microspheres F-20, F-30, F-40, F-50, F-80S manufactured by Matsumoto Yushi Seiyaku Co., Ltd. , F-82, F-85, F-100, F-30VS, F-80GS, F-80VS, F-100SS, F-1300, F-1400, etc .; and Expansel 820 manufactured by Nippon Ferrite Co., Ltd. , 642, 551, 461, 051, 091, and the like, and two or more of these may be used in combination.

[Ratio of (A) and (B)]

In the absorbent composition [1] of the present invention, the mass ratio of (A) to (B) is preferably 100: (0.05 to 10), more preferably 100: (0.1 to 7), and Is 100: (0.5 ~ 5). When (B) is less than 0.05, the effect of improving the absorption rate is poor. On the other hand, when it exceeds 10, the absorption rate can be improved, but the volume increase becomes so large that the mechanical properties of the resulting absorbent composition particles are reduced. In this case, the mechanical strength tends to be weak, and the effect of improving the absorption rate of the resulting absorbent composition under pressure tends to be poor.

[Production method of absorbent composition [1]]

The absorbent composition [1] of the present invention can be obtained, for example, by a production method [3] using a microfilament (B1) or a production method [4] using a heat-expandable hollow filler ({2}). In the production method [3], the fine filler (B1) is incorporated and dried before drying in the step of producing the water-absorbent resin (A) via the hydrogel polymer to obtain an absorbent composition. An embodiment of the production method [3] includes a method of drying a hydrogel of the water-absorbing resin (A) containing the microfilament (B1) to obtain an absorbent composition. This embodiment is a case where the water-absorbent resin (A) is formed before drying, but other forms include a drying step or a drying step or after drying, a thermal crosslinking method or a surface crosslinking method. Thus, a water-absorbing resin can be formed.

In the production method [3] of the present invention, the fine filler (B1) is blended at any stage from before the polymerization of the water-absorbent resin (A) to before the drying. A preferred method is to add and knead the (A) hydrogel polymer in a stage after polymerization to before drying. This is because the addition of (B1) to (A) in the hydrogel state improves the absorption rate because (B1) is contained inside the water-absorbing resin particles.

(B1) can be added in any form of powder, water slurry, and water dispersion.However, in order to enhance the uniformity and the effect of improving the absorption rate of the obtained absorbent composition, water slurry or water It is preferable to add as a dispersion liquid and uniformly add it to the hydrogel.

The water content of the blend of the hydrogel (A) and (B1) is preferably 2 to 10 times the solid content of (A). If it is less than twice, the uniformity at the time of mixing will be low, and the effect of improving the absorption rate of the obtained absorbent composition may be poor. If it is higher than 10 times, it takes a long time to dry, which is not economical.

As a kneading apparatus for blending (B1) with (A) in a hydrogel state and uniformly dispersing the same, a conventionally known apparatus can be used. Specific examples of the device include a double-armed kneader, an internal mixer (bread palry mixer), a self-cleaning mixer, a gear compounder, a screw-type extruder, a screw-type kneader, and a mincing machine. These can be used in combination of two or more.

The drying temperature of the hydrogel formulation containing (B1) is usually from 60 to 230. C, preferably 100-200. C, especially 105-180. C. Drying temperature is 60. If it is less than C, it takes a very long time to dry and is not economical, whereas 230. C If the amount exceeds the above range, side reactions or decomposition of the resin may occur, leading to a decrease in absorption performance and absorption speed.

The device for drying the blend of (A) and (B1) in the hydrogel state may be a conventional device, such as a drum dryer, a parallel flow bread dryer (tunnel dryer), a ventilation band dryer, and a jet flow. (Nozzle jet) Dryer, box type hot air dryer, infrared dryer, etc. The heat source is not particularly limited. These dryers can be used in combination of two or more.

After drying, pulverization and particle size adjustment, the surface of the absorbent composition particles incorporating (B1) is coated with a functional group capable of reacting with acid groups such as lipoxyl graves and Z or its base. Can be surface-crosslinked with a crosslinking agent having at least two of the above to give the absorbent composition of the present invention.

Such a surface cross-linked type absorbent composition is suitable for the present invention because it has excellent absorption performance and absorption rate under normal pressure as well as under load, and also has a high gel strength.

Examples of the cross-linking agent used for the surface chair include polyglycidyl ether compounds (ethylene glycol diglycidyl ether, glycerin-1,3-diglycidyl ether, glycerin triglycidyl ether, polyethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, Polyol compounds (glycerin, ethylene glycol, polyethylene glycol, etc.); polyamine compounds (ethylene diamine, diethylene triamine, etc.); polyamine resins (boriamide polyamine ebichlorhydrin resin, polyamine ebik D) Hydrin resin), alkylene carbonate, aziridine compound, polyimine compound and the like. Preferred are a polyglycidyl ether compound and a polyamine-based resin in that a surface bridge can be formed at a relatively low temperature.

The amount of the cross-linking agent in the surface cross-linking is not particularly limited because it can be variously changed depending on the type of the cross-linking agent, cross-linking conditions, target performance, and the like. However, the amount is usually 0.0 with respect to the absorbent composition. The content is 0.1 to 3% by mass, preferably 0.01 to 2% by mass, and more preferably 0.05 to 1% by mass. When the amount of the crosslinking agent is less than 0.001% by mass, there is no great difference in performance from the water-absorbing resin not subjected to the Jie treatment. On the other hand, over 3% by mass If so, the absorption capacity and water retention tend to decrease, which is not preferable.

If necessary, a blend of (A) and (B1) in a hydrogel form may be used as an additive, as a brightener, a residual monomer reducing agent (eg, sodium sulfite, hydrogen peroxide, etc.), an antibacterial agent (eg, Quaternary ammonium salt compounds, chlorhexidine compounds, metal salt antibacterial agents, etc.), preservatives, fragrances, deodorants, coloring agents, antioxidants, silica, zeolite and the like. These additives can also be added during or after the drying step of the hydrogel composition.

The apparent density of this absorbent composition is lower than the case where (B1) is not blended. It was done. Therefore, the surface area per unit weight is dramatically increased, and the absorption rate is improved.

On the other hand, in the production method [4], a heat-expandable hollow filler (Β2 ') is incorporated and heated and dried before drying in the process of producing the water-absorbent resin (A) via the hydrogel polymer. This is a method for obtaining an absorbent composition in which a microfilament (Β2) formed by thermally expanding (Β2 ') in an aqueous resin (Α) is incorporated.

In an embodiment of the production method [4], the water-containing gel of the water-absorbent resin (Α) containing the heat-expandable hollow filler (Β2 ′) is heated and dried, and the above-mentioned fine filler is contained in the water-absorbent resin (Α). (1) A method for obtaining an absorbent composition incorporating (Β2). This embodiment is a case where the water-absorbent resin (Α) is formed before heating and drying. However, in another embodiment, it is possible to carry out thermal crosslinking or heat drying or after heat drying. It is also possible to form a water-absorbent resin by the surface bridging method.

In the production method [4] of the present invention, (Β2 ′) is combined before polymerization of the water-absorbent resin (Α), that is, in any stage from the step of adjusting the mixing of the raw materials for polymerization to the step of drying. You. Preferably, it is a method in which the mixture is added to the hydrogel polymer in the stage from the stage of mounting (i) to before drying, and the mixture is scoured. This is because (Α) in the hydrogel state has an appropriate flexibility to expand, and can be expanded in volume by heating in the subsequent drying step to increase the surface area. Further, when (Β) is blended with the hydrogel polymer in the stage from the polymerization of (Α) to before drying, a more uniform mixture can be obtained by using a crosslinking agent (for example, a polyglycidyl ether compound) together. Volumetric expansion Inflation can take place.

(Β2 ′) can be added in any form of powder, water slurry, or water dispersion, but is required to promote uniform expansion and the effect of improving the absorption rate of the resulting absorbent composition. Is preferably added in the form of a water slurry or a water dispersion and uniformly added to the hydrogel.

Further, the water content of the blend of the water-containing gel of (II) and (Β2 ′) is preferably 2 to 10 times the solid content of (II). If it is less than 2 times, the expansion ratio will be low, and the effect of improving the absorption rate of the obtained absorbent composition may be poor. If it is higher than 10 times, the drying time becomes longer and it is uneconomical.

As a kneading apparatus for mixing (Β2 ′) with (Α) in a hydrogel state and uniformly dispersing, (B) is mixed with (Α) in the production method [3] of the present invention exemplified above. However, the same kneading device as used for uniform dispersion can be used.

Heat drying temperature (B2 ') hydrogel formulations with added is usually sixty to two hundred thirty ° C, preferably 100 to 200 ^e C, in particular 105 to: L 80. C. If the drying temperature is below 60 ° C, drying takes a very long time and is not economical, whereas 230. If it exceeds C, side reactions or decomposition of the resin may occur, leading to a decrease in absorption performance and absorption speed.

The device for heating and drying the mixture of (A) and (Β2 ') in the form of a hydrogel may be a conventional device, such as a drum dryer, a parallel flow band dryer (tunnel dryer), a ventilation band dryer, Jet flow (nozzle jet) Dryers, box-type hot air dryers, infrared dryers, etc.

When a combustible compound is contained in the void of (Β2 ′), a direct-fired heat source is not preferable, but for a non-combustible compound, the heat source is not particularly limited. These dryers can be used in combination of two or more.

If necessary, after heating and drying, the surface of the absorbent composition particles obtained by pulverization and particle size adjustment is surfaced with a crosslinking agent having at least two functional groups capable of reacting with a carboxylic acid group and / or its base. The absorbent composition of the present invention can be crosslinked. Such a surface cross-linked type absorbent composition is excellent in absorption performance and absorption speed under normal pressure as well as under gravity, and also has a high gel strength, and is therefore preferred for the present invention. Suitable.

As the cross-linking agent to be used for the surface cross-linking, the same one as in the case of the surface cross-linking in the production method [5] of the present invention can be used, and the amount used is also the same.

In the blend of (A) and (Β2 ') in the form of hydrogel, if necessary, additives or thickeners may be used, such as residual monomer inhibitors (eg, sodium sulfite, hydrogen peroxide, etc.), antibacterial agents ( For example, quaternary ammonium salt compounds, chlorhexidine compounds, metal salt antibacterial agents, etc.), preservatives, fragrances, deodorants, coloring agents, antioxidants, silica, zeolites, etc. it can. These additives can also be added during or after the heating and drying step of the hydrogel composition.

[Shape and particle size distribution]

The preferred shape of the absorbent composition [1] of the present invention is particulate, for example, crushed particles obtained by polymerizing an aqueous solution and then drying and pulverizing, or a reverse phase turbidity polymerization method. May be obtained.

The average particle size of the absorbent composition [1] of the present invention is usually from 200 to 600 m, preferably from 250 to 550 Aim. The particle size distribution is usually 1000 π! The content in the range from 100 to 100 / m is 90% by mass or more, preferably 95% by mass or more.

If the average particle size exceeds 600 m or coarse particles exceeding 1000 m exist in excess of 10% by mass, the absorption rate tends to decrease. On the other hand, when fine particles having an average particle diameter of less than 200 m or less than 100 Aim are present in an amount of more than 10% by mass, problems such as a reduction in powder handling properties and a quantitative supply property by a sprayer, and generation of dust are caused. In many cases, the problem of deteriorating the work environment may occur.

[Specific surface area]

The absorbent composition [1] of the present invention is characterized in that the specific surface area is improved by 10% or more as compared with (A) in which (B) is not incorporated. Here, the specific surface area is a value measured by the BET method. Therefore, the specific surface area of (A) in which (B) is not incorporated is compared with the value measured by the BET method. The specific surface area of BE O 99/03577

18

The value measured by the T method is improved by 10% or more.

The specific surface area of the absorbent composition [1] of the present invention having a particle size of 150 to 500 m was 0.1 lm ² / g or more, particularly 0.15 m ² / g or more, as measured by the BET method. Preferably, there is.

[Bulk density]

The bulk density of the absorbent composition [1] of the present invention is usually 0.1 to 0.7 g / cm ³ , preferably 0.1 to 0.55 g cm ³ , particularly 0.2 to 0.5 g / cm ³ . cm ^3.

If it exceeds 0.7 g / cm ³ , the effect of increasing the surface plant per mass is insufficient. The bulk density is a value measured based on JISK 3362.

[Absorption speed, pressure absorption amount]

Since the absorbent composition [1] of the present invention has an improved specific surface area as described above, the absorption rate of physiological saline (Α) without (Β) is not incorporated ( The absorption rate is improved with respect to the absorption time, and the degree of improvement in the absorption rate is preferably 80% or less in time.

That is, the absorption rate of physiological saline (absolute time of absorption of a certain amount) of (1), in which (Β) is not incorporated, is compared with the absorption rate of physiological saline of absorbent composition [1] of the present invention (constant). Is preferably reduced to 80% or less.

The absorbent rate of the physiological saline solution of the absorbent composition [1] of the present invention is preferably 25 seconds or less, particularly 20 seconds or less. With such an absorbent rate, it can be used for sanitary articles such as disposable diapers. In this case, it is effective to improve dry feeling and reduce leakage.

In particular, the absorbent composition [1] of the present invention obtained by surface cross-linking has an improved absorption capacity under pressure and an absorption rate to physiological saline of preferably 25 seconds or less, particularly preferably 20 seconds or less. In addition, the absorption under pressure of 20 g / cm ² for physiological saline can be preferably 25 g / g or more, especially 28 gZg or more.When used for sanitary goods such as disposable diapers, The feeling is further improved and leakage can be further reduced, which is more effective.

Note that the absorption rate and the pressure absorption amount are values measured by the method described below. [Surfactant treatment]

The absorbent composition [2] of the present invention is obtained by further adding a surfactant (C) to the surface of the absorbent composition [1:].

Therefore, the shape and particle size distribution, specific surface area, bulk density, and other physical properties of the absorbent composition [2] of the present invention are basically the same as those of the absorbent composition [1]. The characteristic of fast absorption is maintained.

The type of surfactant (C) is not particularly limited, and any of nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants can be used.

Examples of nonionic surfactants include alkylphenols, aliphatic alcohols, carboxylic acids, aliphatic amines, fatty acid amides, ethylenoxide and active hydrogen-containing compounds such as polyphenylene-modified or amine-modified polysiloxanes.

Selectable from compounds with Z or propylene oxide added (random or block addition when ethylene oxide and propylene oxide are used together), polyhydric alcohols partially esterified with fatty acids, etc. One or more types are mentioned.

The following are specific examples of the non-ionic surfactant.

◎ C10-C24 aliphatic alcohols similarly alkoxylated.

◎ C10-C24 fatty acids similarly alkoxylated.

◎ C10-C24 aliphatic amines also alkoxylated.

◎ Also alkoxylated C10-C24 fatty acid amides.

◎ Polyoxyethylene modified silicone oil.

◎ C3-C6 polyhydric alcohol partially esterified with C10-C24 fatty acids

—2 to 20 moles of ethylene oxide and

And / or a compound to which propylene oxide is further added.

Examples of anionic surfactants include alkali metal salts of (C8-C24) -alkyl sulfonic acids, alkali metal salts of (C8-C24) -alkyl sulfates or Real alkanoammonium salts, sulfosuccinic acid diesters, sulfosuccinic acid monoesters, (C8 C24) -alkylarylsulfonic acids, alkylphenols, and sulfuric acid half-esters of products obtained by adding ethylene oxide to aliphatic alcohols, etc. No. These anionic surfactants can be used in combination of two or more, and can also be used in combination with the above-mentioned nonionic surfactants. Examples of the cationic surfactant include salts of inorganic acids (such as hydrochloric acid) and salts of organic acids (such as acetic acid and citrate) of higher aliphatic amines (such as laurylamine and stearylamine) and higher fatty acids such as lower amines. (Stearic acid, oleic acid, etc.), Solomin A-type quatin surfactant, Sapamin A-type quatin surfactant, Quaternary ammonium salt having long-chain (C10-C22) alkyl (Long-chain alkyl benzyl dimethyl ammonium chloride) And the like, and an inorganic acid or an organic acid salt of an alkylene oxide (such as ethylene oxide) adduct of an aliphatic amine. Examples of the amphoteric surfactant include a compound having at least one cationic group (for example, a quaternary ammonium group) and an anionic group (for example, a carboxylate group or a sulfate group) in the same molecule. Specific examples include dimethylcarboxydimethyl-fatty acid monoalkylamide ammonium quinones, and 3- (3-fatty acid amide doped lovir) dimethylammonium 2-hydroxyhydropropanesulfonates.

Preferred among these are nonionic surfactants having an HLB (Griffin) of 3 or more, especially 8-14. Here, HLB is an indicator indicating the balance between hydrophilicity and lipophilicity of a surfactant, and can be controlled by the type and number of functional groups, or the number of moles and molecular weight of alkylene oxide added.

In the absorbent composition [2] of the present invention, for example, a surfactant (C) is further added to the surface of the absorbent composition [1] obtained by the production method described in the above item [3] or [4]. It is obtained by doing.

The amount of the surfactant (C) is usually 0.1 to 5%, preferably 0.1 to 3%, particularly 0.2 to 2%, based on the quality of the absorbent composition [1]. . When the content of the fleas of (C) is less than 0.1%, the treatment effect of (C) is poor, and almost no improvement in the affinity between the obtained composition and blood can be expected. Things may not be obtained. On the other hand, if the amount of (C) exceeds 5%, it is effective for improving the absorption rate. However, the powder flowability of the resulting composition deteriorates, which may cause problems in powder handling properties, which is not preferred.

By applying the surfactant (C) to the surface of the absorbent composition [1], the surfactant (C) adheres to the surface, and if the surfactant has permeability, it penetrates into the interior of the composition. .

The method of adding the surfactant (C) to the absorbent composition [1] is not particularly limited. For example, the surfactant (C) is mixed with the absorbent composition using a normal mixing device. . The surfactant (C) may be as such or diluted in water or an aqueous liquid.

Examples of specific equipment include a V-type mixer, a repump blender, a turbula mixer, a universal mixer, a Nauta mixer, a fluidized bed mixer, a spray mixer, a line blender, a continuous mixer, and a panbury. Mixer, mortar mixer and the like. These can be used in combination of two or more. [Absorption rate for sheep blood]

The composition [2] of the present invention has an absorption rate to sheep blood of usually 30 seconds or less, preferably 25 seconds or less, and a water retention g after swelling in sheep blood for 30 minutes is usually 20 g /. g or more, preferably 23 g / g or more.

Since the composition [2] of the present invention has such a balance of absorption characteristics (absorption rate and water retention) for blood, it can be used for various absorbent articles (for example, sanitary napkins, panty liners, tampons, surgery) Underpads, puerperal mats, dressings for wound protection, etc.), especially when applied to sanitary napkins, improves the dryness of the surface, reduces leakage, and increases water retention compared to conventional water-absorbent resins. It is a target.

When the composition [2] of the present invention is surface-crosslinked, the amount of absorption under a load against sheep blood is further improved, and the absorption 虽 under a load of ²⁰ g / cm ^{2 is} reduced to 20 g. It is possible to make Z g or more.

Absorption rate to sheep blood, water retention after swelling in sheep blood for 30 minutes, absorption under load to sheep blood, dryness of napkin surface and napkin water retention measured by the methods described below twenty two

Value.

Conventionally, artificial blood (eg, about 0.9% sodium chloride, about 0.4% sodium bicarbonate, about 30% glycerin, about 30% carboxylate, Methylcell mouth sodium (about 0.18%, aqueous solution containing surfactants and coloring agents as needed) has been used, but the absorption behavior by this simulated blood and actual blood (human blood) have been used. , Bovine blood, bovine blood, sheep blood, etc.), it is necessary to use actual blood to determine the absorption performance for blood.

This is because actual blood contains about 45% by volume of 髙 molecular substances such as blood cells, hemoglobin, cytoplasm, and protein components.

[Absorptive articles]

The absorbent article of the present invention comprises an absorbent layer comprising the absorbent composition [1] or [2] of the present invention and a fibrous material wrapped in a surface protective sheet having a water-permeable portion. For example, in the case of adult and children's paper and sanitary products, the surface protection sheet usually consists of a water-impermeable sheet on the outer surface and a water-permeable sheet on the inner surface, depending on the form of use. The absorbent layer is wrapped between the two sheets, and the ends of the two sheets are joined to form a water absorbent article. If necessary, a water-absorbing paper, a liquid diffusion sheet and the like are used together with the absorbing layer between the two sheets.

The fibrous material used in the absorbent layer includes pulp, synthetic fiber, semi-synthetic fiber, natural fiber and the like, and is not particularly limited. The thickness and length of the fibrous material are not particularly limited. Example

Hereinafter, the present invention will be further described with reference to Examples, but the present invention is not limited thereto. Unless otherwise specified,% means mass%.

The measurement methods for the following items 1) to 10) of the water-absorbent resin, the absorbent composition and the napkin are shown below. O 99/03577

twenty three

[Shorted items]

Water absorbent resin and absorbent composition:

1) Specific surface area

Absorbent composition:

2) Absorption rate for 0.9% saline

3) Pressurized absorption halo for 0.9% saline

4) Water retention for 0.9% salt

5) Absorption rate for sheep blood

6) Water retention for sheep blood

7) Absorption under load to sheep blood.

Napkins;

8) Absorption rate for sheep blood

9) Sheep blood diffusion area

10) Surface dryness after sheep blood diffusion

1 1) Water retention for sheep blood

[Measuring method]

1) Measurement method of specific surface area:

The measurement was carried out by BET one-point method using a device manufactured by Cyuasa Ionics Inc. (Canleeve QS-19). The measurement conditions were as follows: He / Kr = 99.1 / 0.1.1 vo 1% for the measurement gas, N _{2 for} the detection gas, and a standard cell as the cell. The water-absorbent resin or absorbent sample used for the measurement was adjusted to 30 to 100 mesh in advance.

2) Method for measuring absorption rate of absorbent composition:

2.00 g of an absorbent composition adjusted to a particle size of 30 to 60 mesh with a JIS standard sieve is prepared as a sample.

A beaker (100 ml capacity) containing 50 g of 0.9% sodium chloride solution in a magnet (08 mm in diameter at the center, 7 mm in diameter at both ends, 30 mm in length, medium size coated with fluororesin) And place the beaker on the center of the magnetic stirrer. twenty four

Adjust the rotation speed of the magnetic stirrer to 600 ± 30 rpm, and confirm that the saline solution forms a stable ^.

As soon as possible, add the sample to the beaker as close to the inner wall of the beaker as possible and avoid contact with the wall. The operation so far is based on J IS K 7224.

The time when the vortex disappeared and the liquid level became horizontal was defined as the end point, and the time required for the end point was measured in seconds to determine the absorption rate.

3) Measuring method of pressure absorption amount of absorbent composition:

Absorbent composition sample adjusted to a particle size of 30 to 60 mesh with a JIS standard screen in a cylindrical plastic tube (inner diameter 30 mm> height 60 mm) with a 250 mesh nylon net attached to the bottom 0.1 'Add 0 g and level.

A weight having an outer diameter of 30 mm is placed on the absorbent composition so as to give a load of 20 g / cm ² . A plastic tube containing the absorbent composition is placed in a petri dish (diameter ø 12 cm) containing 60 ml of 0.9% by mass saline solution with the nylon mesh side facing down. The g of the absorbent composition increased by absorbing 0.9% saline was measured after 5 minutes and 60 minutes.

The 10-fold value of the measured value after 5 minutes was defined as the initial pressure absorption g in 0.9% saline, and the 10-fold value of the measured value after 60 minutes was defined as the pressure absorption amount in 0.9% saline solution.

4) Method for measuring the water retention of the absorbent composition:

In a tea bag (length 20 cm, width 10 cm) made of a 250 mesh nylon net, 1.00 g of the absorbent composition sample adjusted to a particle size of 30 to 60 mesh with a JIS standard sieve was added, and 0.9 mass% was added. Immersed in 500 ml of a saline solution for 60 minutes to absorb, suspended for 15 minutes, cut off, dehydrated with a centrifugal dehydrator at 150 G for 90 seconds, and measured the increased mass. The amount of water retained was 0.9% by mass of saline.

5) Method of measuring absorption rate of absorbent composition to sheep blood:

Prepare a sample of 10 g of the absorbent composition adjusted to a particle size of 30 to 60 mesh with JIS Toru Screen. Place 20 g of sample in a Petri dish (diameter 12 cm), flatten it, and inject 5 g of sheep blood (containing 3.8% of citric acid: made by Towa Jun-Ji) into the center. The time from the start of the infusion until the sheep blood was completely absorbed was measured and defined as the absorption rate.

6) Method of measuring water retention of sheep blood by absorbent composition:

A tea bag (length 20 cm, width 10 cm) made of 250 mesh nylon net, 1.0 g of an absorbent composition sample adjusted to a particle size of 30 to 60 mesh with a JIS standard sieve was put into sheep blood. After immersion for 30 minutes to absorb and swell, suspend by ice for 15 minutes, dehydrate with a centrifugal dehydrator at 250 G for 2 minutes, and measure the increase. This increased weight was defined as water retention for sheep blood.

7) Method for measuring absorption amount of absorbent composition under load to sheep blood:

In a cylindrical plastic tube (inner diameter ^ 30 mm, height 60 mm) with a 250 mesh nylon mesh attached to the bottom, 0.1 g of an absorbent composition sample adjusted to a particle size of 30 to 60 mesh with JIS standard sieve Add and level.

This causes multiplication the weight of the outer diameter ų 30 mm so that the load of 20 gZcm ² on the sample. Place the plastic tube containing the sample in a Petri dish (diameter ø 12 cm) containing 50 g of sheep blood with the nylon net side facing down. The mass of the sample that has absorbed the sheep blood is measured after 30 minutes. The 10-fold value of this measured value was taken as the absorption under load for sheep blood.

8) Measurement method of absorption rate of napkin:

A fluff pulp layer having a basis weight of 100 g / m ² is cut into a size of 6 cm x 15 cm, and 0.4 g of a sample of the absorbent composition is uniformly sprayed thereon. Furthermore, a fluff pulp layer of the same tsubo g and the same size is piled up and pressed on a wire mesh at 10 kgZcm ² for 30 seconds to form an absorber layer.

A leak-proof film larger than the absorber eyebrows is placed on the lower surface, and a rayon nonwoven fabric is placed on the upper surface, and the periphery is heat-sealed along the absorber layer to create a model napkin. Prepare an injection plate with a 12 mm diameter hole in the center of an acryl plate with the same area as the absorber layer of the model napkin, and a 12 mm inner diameter cylinder (10 cm long) fixed on the hole. This injection plate is placed on the model napkin, and a load of 20 g is evenly applied. 5 g of sheep blood is injected from the cylinder, and the time until 5 g of total S is absorbed is measured. This was measured three times and the average value was taken as the absorption rate.

9) Method for measuring napkin diffusion area: 26

After the absorption rate measurement, the area where the sheep blood was absorbed and spread in the absorber layer was determined, and the average value of the three measurements was taken as the diffusion area.

10) Measurement method of surface dryness of napkin:

After measuring the diffusion area, five panelists judge the dryness of the model napkin surface by finger touch. This operation was repeated three times, and the average of these was evaluated according to the following criteria.

®: Good dry feeling.

〇: Slightly moist feeling, but no practical problem.

Rum: There is little leaching of the liquid, but I feel a luck.

X: There is a lot of seepage of the liquid and it is wet.

11) Method for measuring napkin water retention:

Soak the model napkins in excess sheep blood for 5 minutes. Then, the nonwoven fabric was turned outward with centrifugal dehydration at 250 G for 2 minutes to determine the increased weight, and the value obtained by rounding off the first decimal place was used as the water retention capacity. (Example 1)

A 1 liter glass reaction vessel was charged with 77 g of sodium acrylate, 22.8 g of acrylic acid, 0.2 g of N, N, monomethylenebisacrylamide and 295 g of deionized water, stirred, mixed and mixed. While maintaining the temperature of the contents at 3'C.

After flowing nitrogen into the contents to reduce the dissolved oxygen content to 1 ppm or less, a 1% aqueous solution of hydrogen peroxide lg, a 1.2% aqueous solution of ascorbic acid 1.2 g and 2,2, azobisamidino 2.8 g of a 2% aqueous solution of propanedihydrochloride was added, and the mixture was mixed and the polymerization was started, followed by polymerization for about 5 hours to obtain a hydrogel polymer (A1G).

Hydrogel polymer (A1G) after shredding to a size of 3 to 7 mm in inter one internal mixer, Ekusupanseru 091DE (true density - 0. 03g / cm ^3; particle size 50 ~80 ^ m) 2% of the 100 g of the aqueous dispersion (B11) was added, and the mixture was mixed uniformly with an internal mixer. C. Drying was performed with a ventilated band dryer (Inoue Kinzoku Kogyo) at a wind speed of 2.0 m / sec. The obtained dried product was pulverized and adjusted to a particle size of 20 to 100 mesh to obtain an absorbent composition (1). 27

On the other hand, the hydrogel polymer (A1G) is shredded to a size of 3 to 7 mm with an internal mixer, and then is passed through a ventilated pan drier at 150 ° C and a wind speed of 2.0 m / sec. It was dry. The obtained dried product was pulverized and adjusted to a particle size of 20 to 100 mesh to obtain a water-absorbent resin (A1).

Table 1 shows the results of measuring the specific surface area of the water-absorbent resin (A1) and the absorbent composition (1), and calculating the rate of increase in the specific surface area. Table 2 shows the performance evaluation results of the absorbent composition (1).

(Example 2)

While stirring 100 g of the absorbent composition (1) at a high speed, 2 g of a 10% water / methanol mixed solution of ethylene glycol diglycidyl ether (water / methanol = 70/30) was added and mixed. Crosslinking by heating for 30 minutes was performed to obtain a surface crosslinked type absorbent composition (2).

On the other hand, 100 g of the water-absorbent resin (Al) obtained in Example 1 was stirred at a high speed while 2 g of a 10% water / methanol-toluene solution of ethylene glycol diglycidyl ether (water methanol = 70/30) was added. After adding and mixing 140. Heat-crosslinking was performed for 30 minutes at C to obtain a surface-crosslinkable water-absorbent resin (A2).

Table 1 shows the results of measuring the specific surface area of the water absorbent resin (A2) and the absorbent composition (2), and calculating the rate of increase in the specific surface area. Table 2 shows the performance evaluation results of the absorbent composition (2).

(Examples 3, 4)

100 g of the dried product having a particle size of 20 to 100 mesh obtained in the same manner as in Example 1 except that the addition of the dispersion liquid (B11) in Example 1 was changed to 25 g or 250 g, Surface cross-linking was performed in the same manner as in Example 1 to obtain an absorbent composition (3) and an absorbent composition (4).

The specific surface area of the absorbent composition (3), (4) was measured, and the water-absorbent resin (A2)

Table 1 shows the results of calculating the rate of increase of the specific surface area with respect to. Table 2 shows the performance evaluation results of the absorbent compositions (3) and (4).

(Examples 5, 6)

In Example 1, the following dispersion layer (B12) or (B12) was used instead of the dispersion liquid (B11). 28

Except that 13)-was used in the same manner as in Example 1, and the surface was crosslinked in the same manner as in Example 2 to obtain an absorbent composition (5) and an absorbent composition (6).

◎ Dispersion (B12): 2% aqueous dispersion of Expanscel 46 1 DE (true density-0.06 g / cm ³ ; particle size 20 to 40 m).

Table 1 shows the results of measuring the specific surface area of the absorbent compositions (5) and (6) and calculating the rate of increase of the specific surface area with respect to the water-absorbent resin (A2). Table 2 shows the performance evaluation results of the absorbent compositions (5) and (6).

(Example 7)

A 1-liter glass reaction vessel was charged with 77 g of sodium acrylate: 22.8 g of acrylic acid, 0.2 g of Ν, Ν'-methylenebisacrylamide and 293 g of deionized water, and stirred. While mixing, 2 g of Expanscel 09 IDEj was added to keep the contents at a temperature of 3.

After introducing nitrogen into the contents to reduce dissolved oxygen 虽 to 1 ppm or less, a 1% aqueous solution of hydrogen peroxide lg, a 1.2% aqueous solution of ascorbic acid 1.2 g and 2,2, -azo 2.8 g of a 2% aqueous solution of bisamidinopropanedihydrochloride was added and mixed to start polymerization, and polymerization was carried out for about 5 hours to obtain a hydrogel polymer composition (AB1G).

The hydrogel polymer composition (AB1G) was chopped with an internal mixer, and then dried with a ventilated pan drier at 150 ° C and a wind speed of 2.0 m / sec.

The obtained dried product was pulverized and adjusted to a mesh size of 20 to 100 meshes, and 100 g of this product was stirred at a high speed while a 10% water / methanol mixed solution of ethylene glycol diglycidyl ether (permanent / 2 g of methanol (70/30) was added and mixed, followed by heat crosslinking at 140 for 30 minutes to obtain a surface-crosslinkable absorbent composition (7).

Table 1 shows the results obtained by measuring the specific surface area of the absorbent composition (7) and calculating the increase rate of the specific surface area with respect to the water absorbent resin (A2). Table 2 shows the performance evaluation results of the absorbent composition (7). (Example 8)

A 1 liter glass reaction vessel was charged with 81.8 g of acrylic acid, 0.2 g of N, N, -methyl bis (acrylamide) and 241 g of deionized water, and the contents were stirred and mixed. Temperature was kept at 3 ^eC .

After injecting nitrogen into the contents to reduce the dissolved oxygen content to lppm or less, 1% aqueous solution of hydrogen peroxide lg, 0,2% aqueous solution of ascorbic acid 1,2g and 2,2'-azobisamidinopropanedihyd 2.8 g of a 2% solution of D-chloride was added and mixed, and polymerization was started. Polymerization was carried out for about 5 hours to obtain a hydrogel polymer.

This hydrogel polymer was shredded with an internal mixer, and 109.1 g of a 30% aqueous sodium hydroxide solution was added and kneaded, whereby the hydrogel was neutralized with 72 mol% of the carboxylic acid. A polymer (A3G) was obtained.

The same 2% aqueous dispersion (BID 100 g) as in Example 1 was added to the hydrogel polymer (A3G), and the mixture was uniformly mixed using an internal mixer. It dried with the ventilation type band dryer of the conditions.

The obtained dried product is pulverized, adjusted to a particle size of 20 to 100 mesh, and 100 g of this is stirred at a high speed while a 10% water / methanol mixed solution of ethylene glycol diglycidyl ether (water / methanol). = 70/30) was added and mixed, followed by heat crosslinking at 140 for 30 minutes to obtain a surface-framed absorbent composition (8).

On the other hand, the hydrogel polymer (A3G) was uniformly mixed with an internal mixer, and then dried with a ventilated band dryer at 150 ° C and a wind speed of 2. Om / sec. The obtained dried product was pulverized and adjusted to a particle size of 20 to 100 mesh. Then, 100 g of this product was stirred at a high speed while a 10% water / methanol mixed solution of ethylene glycol diglycidyl ether (water / methanol = 70). / 30) and add 2 g and mix. By heating and crosslinking with C for 30 minutes, a surface-Ji bridge type water-absorbent resin (A3) was obtained. The specific surface areas of the water-absorbent resin (A3) and the absorbent composition (8) were measured, and the results obtained by calculating the addition ratio of the specific surface area are shown in Table 1. Also, the performance evaluation of the absorbent composition (8) Table 2 shows the results.

(Comparative Example 1) The water absorbent resin (A1) obtained in Example 1 was used as a comparative absorbent composition (cl), and the performance evaluation results are shown in Table 2.

(Comparative Example 2)

The water absorbent resin (A2) obtained in Example 2 was used as a comparative absorbent composition (c2), and the performance evaluation results are shown in Table 2.

(Comparative Examples 3, 4)

100 g of a dried product having a particle size of 20 to 100 mesh obtained in the same manner as in Example 1 except that the amount of the dispersion liquid (B11) added was changed to 2 g or 600 g in Example 1, Surface cross-linking was performed in the same manner as in Example 2 to obtain a comparative absorbent composition (c3) and a comparative absorbent composition (c4).

Table 1 shows the results obtained by measuring the specific surface 稂 of the comparative absorbent compositions (c 3) and (c 4) and calculating the rate of increase of the specific surface area with respect to the water-absorbent resin (A 2).

Table 2 shows the performance evaluation results of the comparative absorbent compositions (c3) and (c4).

(Comparative Example 5)

100 g of a dried product having a particle size of 20 to 100 mesh obtained in the same manner as in Example 1 except that the same amount of the following dispersion liquid (B14) is used in place of the dispersion liquid (B11) in Example 1 Was subjected to surface crosslinking in the same manner as in Example 2 to obtain a comparative absorbent composition (c5).

Table 1 shows the results of measuring the specific surface area of the comparative absorbent composition (c5) and calculating the rate of increase of the specific surface area with respect to the water absorbent resin (A2). Table 2 shows the performance evaluation results of the comparative absorbent composition (C5).

Dispersion (BU): 2% aqueous dispersion of Mazumoto Mike D-Sfair-1 MF L80 QTA (true density: 0.2 g / cm3; particle size: 20 m, manufactured by Matsumoto Yushi Jie Co., Ltd.).

(Comparative Example 6)

The hydrogel polymer (A1G) obtained in Example 1 was shredded to a size of 3 to 7 mm with an internal mixer, and then thermally decomposed foaming agent “Vinihole AZ-S” (decomposition) Temperature 100. C, main component: azobisisobutyronitrile, manufactured by Eiwa Kasei Kogyo Co., Ltd.) was added at 2% based on the solid content of (A 1 G), and then uniformly mixed with an internal mixer. Ventilation band drying at 150 ° C, wind speed 2. Om / sec 31

Machine). The obtained dried product is pulverized and adjusted to a particle size of 20 to 100 mesh. Then, 100 g of the dried product is stirred at a high speed while a 10% water / methanol mixed solution of ethylene glycol diglycidyl ether (water / methanol = 70). / 30) was added and mixed, followed by heating at 140 ° C. for 30 minutes to obtain a comparative absorbent composition (c6) of a surface cross-linked type.

Table 1 shows the results of measuring the specific surface area of the comparative absorbent composition (c6) and calculating the rate of increase of the specific surface area with respect to the water absorbent resin (A2). Table 2 shows the performance evaluation results of the comparative absorbent composition (c6).

(table 1 )

: Table 2)

Absorbent composition Absorption rate Initial pressure water absorption: § Pressure water absorption 水 Water retention

(Sec) (g / g) (g / g) (g / g) Example 1 (1) 17 14 17 53 Example 2 (2) 15 24 33 41 Example 3 (3) 19 23 34 41 Example 4 (4) 11 27 33 41 Example 5 (5) 18 23 34 41 Example 6 (6) 17 25 33 41 Example 7 (7) 16 24 33 41 Example 8 (8) 16 26 36 44 Comparative example 1 (cl) 35 5 16 53 Comparative Example 2 (c2) 34 18 33 41 32

(Example 9)

A hydrogel polymer (A 1 G) was obtained in the same manner as in Example 1.

After slicing the hydrogel polymer (A1G) to a size of 3 to 7 mm with an internal mixer, "Matsumoto Microsphere; F-30" (expansion start temperature 85 to 90. C, maximum expansion temperature 130-140 ° C, expansion ratio approx. 72 times) /. Add 10 g of the aqueous dispersion (B21), mix evenly with an internal mixer, and dry with a ventilated band dryer (made by Inoue Metal Industry) at 150 ° C and a wind speed of 2.0 m / sec. did. The obtained dried product was pulverized and adjusted to a particle size of 20 to 100 mesh to obtain an absorbent composition (9).

Table 3 shows the results of measuring the specific surface area of the absorbent composition (9) and measuring the rate of increase of the specific surface area with respect to the water-absorbent resin (A1). Table 4 shows the performance evaluation results of the absorbent composition (9).

(Example 10)

Absorbent composition (9) 100 g of high-speed stirring was added to 2 g of a 10% water / methanol mixed solution (water / methanol = 70/30) of ethylene glycol diglycidyl ether, followed by mixing. Crosslinking by heating for 30 minutes at C gave a surface crosslinked type absorbent composition (10).

Table 3 shows the results of measuring the specific surface area of the absorbent composition (10) and calculating the rate of increase of the specific surface area with respect to the surface-crosslinked type water-absorbent resin (A2). Table 4 shows the performance evaluation results of the absorbent composition (10).

(Examples 11 and 12)

In Example 9, except that the addition amount of the dispersion liquid (B21) was changed to 2.5 g and 25 g, respectively, a dried product having a particle size of 20 to 100 mesh and 10 Og obtained in the same manner as in Example 9, The surface was crosslinked in the same manner as in Example 10 to obtain an absorbent composition (1.1) and an absorbent composition (12). 33

Table 3 shows the results of measuring the specific surface areas of the absorbent compositions (11) and (12) and calculating the rate of increase of the specific surface area with respect to the surface-crosslinkable water-absorbent resin (A2). Table 4 shows the performance evaluation results of the absorbent compositions (11) and (12).

(Examples 13, 14)

In Example 9, the following dispersion liquid was used instead of the dispersion liquid (B21).

An absorbent composition (13) and an absorbent composition (14) were obtained in the same manner as in Example 9 except that the same g of (B2Z) or (B23) was used, and surface-crosslinked in the same manner as in Example 10. .

Dispersion (B23): 20% aqueous dispersion of Matsumoto Microsphere: F-40j (expansion temperature: 10D to 105 ° C, maximum expansion temperature: 130 to: I40, expansion ratio: 46 times).

Dispersion (B24): A 20% aqueous dispersion of "Matsumoto Microsphere I F-20" (expansion temperature 80-85. C, maximum expansion temperature 105-115 C, expansion ratio about 43 times). Table 3 shows the results of measuring the specific surface areas of the absorbent compositions (13) and (1) and calculating the rate of increase in the specific surface area with respect to the surface-crosslinkable water-absorbent resin (A2). Table 4 shows the performance evaluation results of the absorbent compositions (13) and (14).

(Example 15)

A 1 liter glass reaction vessel was charged with 77 g of sodium acrylate, 22.8 g of acrylic acid, 0.2 g of N, N, methylenebisacrylamide and 293 g of deionized water, stirred and mixed. While adding 2 g of "Matsumoto mylos F-30", the temperature of the contents was kept at 3 ° C.

After flowing nitrogen into the contents to reduce the accumulated acid concentration to 1 ppm or less, a 1% aqueous solution of hydrogen peroxide (lg), a 1.2% aqueous solution of ascorbic acid (1.2 g) and 2,2, -azo 2% aqueous solution 2. added 8 g of bis amidinopropane Jihai Dorokurorai de, mixed combined to initiate the polymerization, to obtain hydrogel polymer formulation (AB 2 G) by polymerizing about 5 hours ₀

The hydrogel polymer blend (AB 2G) was shredded with an internal mixer, and then dried with a ventilated pan drier at 150 ° C and a wind speed of 2.0 m / sec.

The obtained dried product is pulverized and adjusted to a particle size of 20 to 100 mesh. 34

While stirring 1.00 g of the mixture at a high speed, 2 g of a 10% aqueous solution of ethylene glycol diglycidyl ether (water / methanol = 70/30) was added and mixed, followed by heating at 140 for 30 minutes. As a result, a surface frame type absorbent composition (15) was obtained.

Table 3 shows the results obtained by measuring the specific area of the absorbent composition (15) and calculating the rate of increase in the specific surface area with respect to the surface-absorbing water-absorbent resin (A2). In addition, Table 4 shows the performance evaluation results' of the absorbent composition (15).

(Example 16)

In the same manner as in Example 8, a hydrogel polymer (A3G) in which 72 mol% of the carboxylic acid was neutralized was obtained.

10 g of the same dispersion coat (B21) as in Example 9 was added to the hydrogel polymer (A 3 G), and the mixture was uniformly mixed with an internal mixer. C, Drying was performed with a ventilated pan drier at a wind speed of 2.0 msec.

The obtained dried product is pulverized, adjusted to a particle size of 20 to 100 mesh, and 100 g of the obtained product is stirred at a high speed while a 10% water / methanol mixed solution of ethylene glycol diglycidyl ether (water / methanol = 70/30) was added and mixed, followed by heat crosslinking at 14 CTC for 30 minutes to obtain a surface crosslinked absorbent composition (16).

The specific surface area of the absorbent composition (16>) was measured, and the result of calculating the rate of increase of the specific surface area with respect to the surface-crosslinkable water-absorbent resin (A3) obtained in Example 8 is shown in Table 3. Table 4 shows the results of evaluating the performance of the agent composition (16).

(Comparative Examples 7, 8)

In Example 9, 100 g of a dried product having a particle size of 20 to 100 mesh obtained in the same manner as in Example 9 except that the added amount of the dispersion liquid (B21) was changed to 0.2 g or 60 respectively, Surface cross-linking was performed in the same manner as in Example 10 to obtain a comparative absorbent composition (c7) and a comparative absorbent composition (c8).

Table 3 shows the results of measuring the specific surface area of the comparative absorbent compositions (c7) and (c8), and calculating the rate of increase of the specific surface area with respect to the surface-crosslinked type water-absorbent resin (A2). Table 4 shows the performance evaluation results of comparative absorbent compositions (c7) and (c8). 35

(Table 3)

(Table 4

(Example 17)

An absorbent composition (9) was obtained in the same manner as in Example 9.

100 g of this absorbent composition (9) is placed in a V-type mixer (capacity 300 ml), and while rotating, a polyoxyethylene-modified silicone oil (“Shin-Etsu Silicone KF-618”, Shin-Etsu Chemical; HLB = 14)

0.1 g was added and mixed to obtain an absorbent composition (17) of the present invention. Table 5 shows the performance evaluation results of the absorbent composition (17).

(Example 18)

Using 100 g of the absorbent composition (9) obtained in Example 9, a 5% aqueous solution of ethylene glycol diglycidyl ether in methanol and methanol (water Z methyl alcohol = 70 / 30) was added 2.5 times, and the mixture was heated at 140 ° C for 30 minutes to form a surface crosslinked absorbent composition.

(18 ').

100 g of this absorbent composition (18 ') is placed in a V-type Nami-ai machine (capacity: 300 ml), and while being rotated, 0,1 g of the same polyoxyethylene-modified silicone oil as in Example 17 is added and mixed. Thereby, the absorbent composition (18) of the present invention was obtained. Table 5 shows the performance evaluation results of the absorbent composition (18).

(Examples 19 and 20)

In the same manner as in Examples 11 and 12, an absorbent composition (11) and an absorbent composition (12) were obtained.

Put 100 g of each of the absorbent compositions (11) and (12) in a V-type mixer (capacity: 300 ml), and add 0.1 g of the same polyoxyethylene-modified silicone oil as in Example 17 while rotating. Then, the absorbent compositions (19) and (20) of the present invention were obtained by mixing. Table 5 shows the results of these performance evaluations.

(Example 21 ^ 24)

Absorbent compositions (2) and (5) were obtained in the same manner as in Examples 2 and 5. Further, absorbent compositions (13) and (14) were obtained in the same manner as in Examples 13 and 14.

100 parts of each of these absorbent compositions (2), (5), (13) and (14) were placed in a ¥ -type mixer (capacity: 300 ml), and the same polyoxyethylene-modified silicone oil as in Example 17 was rotated while rotating. By adding and mixing 0.1 g of the absorbent, the absorbent compositions (21) to (24) of the present invention are obtained. Table 5 shows the results of these performance evaluations.

(Examples 25 to 28)

In Example 18, the absorbent composition of the present invention (25) to (28) was prepared in the same manner as in Example 18 except that the following surfactant was used in the same amount instead of the polyoxyethylene-modified silicone oil. I got Table 5 shows the results of the evaluation of these properties. 37

Used for the absorbent composition (25): Polyoxyethylene lauryl 'myristyl ether (“Nonipol Soft SS-50” manufactured by Sanyo Chemical Industries; HLB = 10.6).

Used for the absorbent composition (26): polyoxyethylene nonylphenol ("NOPOL 40" manufactured by Sanyo Chemical Industries; HLB = 8.9).

Used for absorbent composition (27): Polyoxyethylene lauryl ether sodium sulfate (“Sanded ENj Sanyo Chemical Industries; anionic surfactant”).

Used in absorbent composition (28): polyoxyethylene lauroyl ethanolamide disodium succinate ("Bulite A-5000" manufactured by Sanyo Chemical Industries; amphoteric surfactant).

(Example 29)

In the same manner as in Example 15, an absorbent composition (15) was obtained. This absorbent composition (1

5) 100 g was placed in a V-type mixer (capacity: 300 ml), and while rotating, 0.1 g of the same polyoxyethylene-modified silicone oil as in Example 17 was added and mixed, whereby the absorbent composition of the present invention was obtained. A product (29) was obtained. Table 5 shows the performance evaluation results of (29).

(Example 30)

In the same manner as in Example 16, an absorbent composition (16) was obtained. This absorbent composition (1

6) Put 100 g into a mold mixer (capacity: 300 ml), add and mix 0.1 g of the same polyoxyethylene-modified silicone oil as in Example 17 while rotating, and mix the absorbent composition of the present invention ( 30) was obtained. Table 5 shows the results of the performance evaluation of the composition (30).

(Table 5) Evaluation results of absorbent composition by bulk density and sheep blood O 99/03577 38

(Comparative Example 9)

The comparative absorbent composition (c1) obtained in Comparative Example 1 was used as a comparative absorbent composition (c9), and the results of measurement of bulk density and evaluation using sheep blood are shown in Table 6.

Comparative Example 10

The comparative absorbent composition (c 2) obtained in Comparative Example 2 was used as a comparative absorbent composition (c 10), and the results of measurement of bulk density and evaluation using sheep blood are shown in Table 6.

Comparative Example 11-16

Absorbent composition (9) obtained in Example 9, surface-crosslinked type absorbent composition (18 ') obtained in Example 18, absorbent composition (2) obtained in the same manner as in Examples 2 and 5. ), (5), Absorbent compositions (13), (14) obtained in the same manner as in Examples 13 and 14 are referred to as comparative absorbent compositions (cll) to (cl6), respectively. Table 6 shows the evaluation results.

Comparative Example 17

100 g of the comparative absorbent composition (c9) obtained in Comparative Example 9 was put in a V-type mixer (volume: 300 ml), and the same polyoxyethylene-modified silicone oil as in Example 17 was rotated while rotating. 1 g was added and mixed to obtain a comparative absorbent composition (c17). Table 6 shows the performance evaluation results of the comparative absorbent composition (c17). Comparative Example 18

The hydrogel polymer (AB 2 G) obtained in Example 15 was cut into a size of 3 to 7 mm with an internal mixer, and then 150. C, wind speed 2. Dried with a ventilated band dryer at Om / sec. The obtained dried product is pulverized and adjusted to a particle size of 20 to 1 Q0 mesh. The dried product having the adjusted particle size is subjected to surface crosslinking as in Example 2. 39

With this, a comparative absorbent composition (c18) was obtained. Table 6 shows the evaluation results of the comparative absorbent composition (c18).

Comparative Example 19

The hydrogel polymer (A1G) obtained in Example 1 was cut into pieces having a size of 3 to 7 mm using an internal mixer, and then a thermal decomposition type foaming agent “Vinihole AZ—S j ( Decomposition temperature 100 C, main component: azobisisobutyronitrile, manufactured by Eiwa Kasei Kogyo Co., Ltd.) was added at 2% to the solid content of (A 1 G), and after uniform mixing with an internal mixer, At 150 ° C and a wind speed of 2.0 m / sec with a ventilated band dryer.The dried product obtained was pulverized and adjusted to a particle size of 20 to 100 mesh to obtain a comparative absorbent composition ( Table 6 shows the evaluation results of the comparative absorbent composition (c19).

(Table 6) Evaluation results of comparative absorbents by bulk density and sheep blood

(Examples 31 to 37)

Absorbent compositions (17) to (20) obtained in Examples 17 to 20, Absorbent compositions (23) obtained in Example 23, Absorbent compositions (25) obtained in Example 25 And Model napkins were prepared using the absorbent composition (29) obtained in Example 29, and the results of evaluating these performances are shown in Table 7. 40

(J: Comparative example 20-25)

Comparative absorbent composition obtained in Comparative Example 9 (c 9), Comparative absorbent composition obtained in Comparative Example 11 (c 11), Comparative absorbent composition obtained in Comparative Example 15 (C15) and comparative absorbent compositions (cl7) to (cl9) obtained in Comparative Examples 17 to 19, comparative model napkins were prepared and their performance was evaluated. Table 7 shows the results.

(Table 7) Evaluation results using model napkins

Industrial applicability

The absorbent composition and the production method of the present invention have the following features and effects. (1) Since the absorption rate under normal pressure is high and the initial pressure absorption amount (absorption rate under pressure) is excellent, when used as an absorbent for sanitary goods, for example, the effect of improving the initial dry feeling and reducing the leakage is obtained. Demonstrate.

②Excellent water retention and pressure absorption.

(3) The effects of (1) and (2) are exhibited even with a normal particle size, so the powder is excellent in handling. Moreover, unlike a granulated product of fine particles, there is almost no generation of fine particles due to mechanical shearing force or friction. ④ Since the effects of (1) and (2) are exhibited even with a normal particle size, when mixed with a woven material such as pulp to form an absorber, even if external force such as vibration is applied, the fiber Almost no detachment.

Unlike the improvement of the absorption rate by the thermal decomposition type foaming agent, there is no generation of radicals and the like during heating and drying, so that an absorbent composition having excellent absorption performance and a small amount of water-soluble components can be obtained.

⑥ Ru can improve the absorption rate in a simple method of heat drying by blending fine filler to hydrogel of any stage before the polymerization of the water-absorbent resin to a dry炫前₆

もの Surfactants treated with surfactants have a high absorption rate for blood and blood, and have excellent water retention properties. For example, when used as an absorbent for sanitary goods (especially sanitary napkins), the surface dryness can be improved. It has an excellent effect on the reduction of leaks. It also exhibits excellent absorption performance and absorption rate for other body coats (urine, breast milk, amniotic fluid at birth, etc.).

もの Applied to absorbent articles, such as sanitary napkins, to improve absorption rate, diffusion area, surface dryness, water retention, etc., compared to conventional water-absorbent resins An excellent napkin is obtained.

Due to the above effects, the absorbent composition of the present invention can be used for various absorbent articles, for example, disposable disposable diapers (children and adult disposable diapers), sanitary napkins, pads for incontinent persons, breast milk pads. It is particularly suitable for sanitary and medical products such as a pad, a surgical underpad, a puerperium mart, and a dressing material for wound protection. It is also suitable for use with various absorbent sheets (eg, urine absorbent sheet, freshness preserving sheet, drip absorbing sheet, paddy rice seedling seedling sheet, concrete curing sheet, water running prevention sheet for cables, etc.). be able to. Furthermore, it is used in applications where powders of absorbent compositions are applied (for example, soil preservatives, sludge solidifying agents, solidifying agents such as waste blood and aqueous effluents, urine gelling agents, battery electrolyte gelling agents, etc.). Can also be suitably used.

Claims

The scope of the claims

1. An absorbent composition with a structure in which a fine filler (B) is incorporated in the water-absorbent resin (A). The ratio is higher than that of the water-absorbent resin (A) in which the fine filler (B) is not incorporated. An absorbent composition having a surface area improved by 10% or more.

2. The absorption rate of the water-absorbent resin (A) in which the fine filler (B) is not incorporated is 80% or less of the absorption rate of physiological saline (time for absorbing a certain amount). Absorbent composition.

3.A particulate absorbent composition having an average particle size of 200 to 600 m, and having a particle size of 150 to 500 in, has a specific surface area of at least 0.1 lm ² / g as measured by the BET method. 3. The absorbent composition according to claim 1 or 2.

4. The absorbent composition according to any one of claims 1 to 3, wherein the absorption rate of physiological saline is 25 seconds or less.

5. The absorbent composition according to any one of claims 1 to 4, wherein the mass ratio of the water-absorbent resin (A) to the fine filler (B) is 100: (0.05 to 10).

6. The fine filler (B1) according to any one of claims 1 to 5, wherein the fine filler (B) is a fine filler (B1) having a true density of 0.1 g / cm ³ or less and a particle size of 1 to 20 O ^ m. The absorbent composition according to any one of the preceding claims.

7. The fine filler (B1) is a hollow filler made of at least one resin material selected from the group consisting of polyacrylate, polymethacrylate, polypinylidene chloride, polyvinyl acetate and polyacrylonitrile. The absorbent composition as described in the above.

8. The absorbent composition according to claim 6, wherein the water-containing gel of the water-absorbent resin (A) in which the fine filler (B1) is incorporated is obtained by drying.

9. Particles obtained by drying and pulverizing the fine particles (B1) embedded in the water-containing gel of the water-absorbent resin (A) are surface-crosslinked, and the water-absorbent resin (A) is surface-crosslinked. The absorbent composition according to any one of claims 6 to 8, wherein the composition is formed as particles.

10. The fine filler (B2) according to any one of claims 1 to 5, wherein the fine filler (B) is a fine filler (B2) obtained by thermally expanding a thermally expandable hollow filler (B2 ') having a particle size of 1 to 150 m. Absorbent composition.

11. The absorbent composition according to claim 10, wherein the thermally expandable hollow filler (B2 ') is a minute hollow resin containing a gas or a volatile substance in a void.

12. The absorbent composition according to claim 10 or 11, wherein a volume expansion ratio of the thermally expandable hollow filler (B2 ') due to thermal expansion is 10 times or more.

13. The heat-expandable hollow filler (# 2 ') has a thermal expansion start temperature of 60 to 150. C. The absorbent composition according to any one of claims 10 to 10, which is a thermally expandable hollow filler having a property of a maximum expansion temperature of 80 to 18 CTC.

14. The absorbent composition according to any one of claims 10 to 13, wherein a substance in which the thermally expandable hollow filler (# 2 ') is incorporated in the hydrogel of the water absorbent resin (A) is heated and dried. object.

15. Particles obtained by heating, drying and pulverizing the water-absorbent resin (Β2) incorporated in the hydrogel of the water-absorbent resin (Α) are subjected to surface cross-linking, and the water-absorbent resin (樹脂) is subjected to surface treatment. 15. The absorbent composition according to claim 10, which is formed as cross-linked particles.

16. An absorbent composition having a structure in which microfilaments (B) are incorporated in a water-absorbent resin (A), and having a physiological saline absorption rate of 25 seconds or less.

17. bulk density 0. 1~0. 55 g / cm ³ and an average particle size of the absorbent composition of claim 16 which is a particulate 200 to 600 m.

18. water-absorbing resin (A) is a water-absorbent resin having a surface cross-linked structure, pressurized intake yield of the composition at 20 gZ cm ² Conditions saline is 25 g / g or more, claim 18. The absorbent composition according to 16 or 17.

19. An absorbent composition obtained by further adding a surfactant (C) to the surface of the absorbent composition according to any one of claims 1 to 18.

20. The absorbent composition according to claim 19, wherein the surfactant (C) is a nonionic surfactant of HLB 8-14.

21. The surface of the absorbent particles mainly composed of water-absorbent resin (A), having a bulk density of 0.1 to 0.55 g / cm ³ and an average particle size of 200 to 600 Aim, ), Wherein the absorbent composition has an absorption rate for sheep blood of 30 seconds or less and a water retention capacity after swelling in sheep blood for 30 minutes of 20 gZg or more.

22. The absorbent榭脂(A) and before the drying step to produce a hydrogel polymer Te絰, below the true density of 0. 1 g / cm ^a, particle size of 1 to 200 m micro FILLER A method for producing an absorbent composition, wherein (A1) is incorporated and dried.

23. Before drying in the process of manufacturing the water-absorbent resin (A) through the hydrogel polymer, heat-dry with a built-in heat-expandable hollow filler ('2') having a particle size of 1 to 150 m to absorb water. A method for producing an absorbent composition in which a micro-filler (Β2) formed by thermally expanding a thermally-expandable hollow filler () 2 ') is incorporated in a water-soluble resin (Α).

24. A method for producing an absorbent composition, wherein the particles of the absorbent composition obtained by the production method according to claim 22 or 23 are surface-crosslinked.

25. A method for producing an absorbent composition, wherein the surface of the composition obtained by the production method according to any one of claims 22 to 24 is further provided with a surfactant (C).

26. An absorbent article, wherein the absorbent layer comprising the absorbent composition according to any one of claims 1 to 21 and a fibrous material is wrapped in a surface protective sheet having a water-permeable portion.