WO2008020561A1

WO2008020561A1 - Process for producing cured magnesia cement foam, cured foam obtained by the process, and molded object comprising the cured object

Info

Publication number: WO2008020561A1
Application number: PCT/JP2007/065612
Authority: WO
Inventors: Eigo Sugiyama; Hideyuki Hatanaka; Masato Ohtsubo; Yasushi Kogi; Hiroyuki Suzuki
Original assignee: Nitto Boseki Co., Ltd.
Priority date: 2006-08-16
Filing date: 2007-08-09
Publication date: 2008-02-21
Also published as: JP2009256112A; TW200829532A

Abstract

A process for producing a cured magnesia cement foam which comprises preparing an aqueous solution of magnesium chloride, mixing this aqueous solution with a water-reducing agent and magnesium oxide, subsequently introducing a blowing agent thereinto, stirring them to prepare an aqueous slurry, and curing the aqueous slurry obtained, wherein the magnesium oxide and the magnesium chloride are used in a molar ratio of (7-13):1 and the water-reducing agent comprises a carboxylic acid type water-reducing agent and a sulfonic acid type water-reducing agent in a proportion of from 1:5 to 2:1 by weight. By the process, a cured magnesia cement foam can be produced which decreases only slightly in strength with decreasing density.

Description

Specification

Method for producing magnesia cement foam cured product, foamed cured product obtained by the production method, and molded product containing the cured product

Technical field

[0001] The present invention relates to a method for producing a magnesia cement foam cured product, a foam cured product obtained by the production method, and a molded product including the cured product. More specifically, using a specific compounding ratio of magnesium chloride and magnesium oxide, and using a carboxylic acid-based water reducing agent and a sulfonic acid-based water reducing agent at a specific weight ratio as water reducing agents, the bubble size is uniform and small. A method for producing a magnesia cement foam cured product that can obtain a magnesia cement foam cured product having excellent dimensional stability, strength, water absorption, etc. even at low density, and a foam cured product obtained by the production method and The present invention relates to a molded product containing the cured body.

Background art

[0002] Conventionally, cement has been widely used as a main raw material for concrete and mortar in the civil engineering industry, and many types of cement have been developed according to their use. As such a cement, magnesia cement (also called magnesium oxide chloride cement) is known together with the most typical Portland cement. Compared with Portland cement, this magnesia cement has features such as higher strength and adhesion to other materials, and less dust generation. It is widely used for building materials such as flooring. In order to further expand the application of magnesia cement, various studies have been made so far, such as improvement of water resistance (Patent Document 1) and production of foam (Patent Document 2)!

Not only magnesia cement, but cement generally has higher strength such as bending strength than gypsum, wood and fiber materials, but has a drawback of high density. When foam is used to reduce the density, there is a problem that it is brittle and easily broken. Furthermore, the foam has a problem that the amount of water absorption increases.

Accordingly, it has been desired to develop a magnesia cement that is small in strength reduction even if the density is reduced by foaming. Patent Document 1: JP-A-56-26755

Patent Document 2: Japanese Patent No. 53-12927

Disclosure of the invention

Problems to be solved by the invention

[0003] Accordingly, the object of the present invention is to produce a magnesia cement foamed cured product having a small decrease in strength and a small amount of water absorption even when the density of the foamed material is lowered, and foam curing obtained by the production method. It is providing the molded object containing a body and its hardening body.

Means for solving the problem

[0004] As a result of diligent research to solve the above problems, the present inventors have used magnesium chloride and magnesium oxide in a specific blending ratio, and specified a carboxylic acid-based water reducing agent and a sulfonic acid-based water reducing agent as water reducing agents. By using a weight ratio to produce a magnesia cement foam hardened body, it is possible to obtain a magnesia cement foam hardened body that is excellent in dimensional stability, strength, water absorption, etc. even if the cell size is uniform and the density is low and the density is low. As a result, the present invention was completed.

[0005] That is, the present invention is a method for producing a magnesia cement foam hardened body, in which an aqueous solution of magnesium chloride is prepared, a water reducing agent and magnesium oxide are mixed in the aqueous solution, and a foaming agent is added at the next stage. And stirring to prepare an aqueous slurry, and curing the resulting aqueous slurry to produce a magnesia cement foam cured product, using magnesium oxide and magnesium chloride in a molar ratio of 7 to 13: 1 As a water reducing agent, use a carboxylic acid type water reducing agent and a sulfonic acid type water reducing agent in a weight ratio of 1: 5 to 2: 1 to obtain a uniform and small bubble size! The present invention relates to a method of producing a foamed cured magnesia cement.

Furthermore, the present invention relates to a magnesia cement foam hardened body obtained by the above production method.

Furthermore, the present invention relates to a molded product containing the magnesia cement foam cured body.

The invention's effect

[0006] In the present invention, a water reducing agent is used using magnesium chloride and magnesium oxide in a specific mixing ratio. As described above, by producing a magnetic cement foam cured body using a specific weight ratio of a carboxylic acid-based water reducing agent and a sulfonic acid-based water reducing agent, even if the density of the cured body with a uniform and small bubble size is low, An excellent magnesia cement foam hardened body with low dimensional shrinkage, excellent dimensional stability, high strength and low water absorption is obtained. This magnesia cement foam hardened body can be widely used for building materials, etc. by forming it into a board shape, sheet shape, column shape, block shape or the like.

BEST MODE FOR CARRYING OUT THE INVENTION

[0007] Magnesium chloride (MgCl) used in the present invention

2) is preferably magnesium chloride hexahydrate. Magnesium chloride may replace up to 50% by weight with magnesium sulfate. As magnesium sulfate, magnesium sulfate 7 hydrate is preferable. In the production method of the present invention, first, an aqueous solution of magnesium chloride is prepared. The concentration of the aqueous solution at this time is preferably 10% to 20% by weight of solid content concentration of magnesium chloride.

[0008] A water reducing agent is mixed in this aqueous solution. As the water reducing agent, a carboxylic acid type water reducing agent and a sulfonic acid type water reducing agent are used in a weight ratio of 1: 5 to 2: 1, and preferably in a ratio of 1: 4 to 3: 2. Examples of the carboxylic acid-based water reducing agent include polycarboxylic acids (for example, polystreptonic acid ether-based compounds), oxycarboxylic acids (for example, sodium oxycarboxylate), and the like. Examples of the sulfonic acid-based water reducing agent include lignin sulfonic acids (for example, calcium lignin sulfonate), aromatic sulfonic acids (for example, sodium naphthalene sulfonate monoformalin condensate), melamine sulfonic acids (for example, melamine resin). Sodium sulfonate monoformalin condensate etc.)

Yes

[0009] Further, magnesium oxide is mixed into the magnesium chloride aqueous solution. As the magnesium oxide, active magnesium having high activity obtained by baking magnesium hydroxide, magnesium carbonate or the like at a high temperature is preferable. In the present invention, magnesium oxide and magnesium chloride are used in a molar ratio of 7 to 13: 1, preferably 9 to 13: 1. A foam stabilizer may be mixed together with magnesium oxide. Examples of foam stabilizers include zinc stearate, calcium stearate, barium stearate, and aluminum stearate. , Magnesium stearate, calcium laurate, barium laurate and the like. Further, reinforcing fibers such as glass fiber, carbon fiber, and synthetic resin fiber, and fillers such as one microfiber may be mixed together.

[0010] Phosphoric acid or a phosphoric acid compound may be further mixed into the magnesium chloride aqueous solution.

Examples of the phosphoric acid compound include ammonium phosphate, polyphosphate, and hexametaphosphate. By using such phosphoric acid or a phosphoric acid compound, the wet strength of the aqueous slurry prepared before curing the magnetic cement can be improved and the viscosity can be increased.

In the present invention, the above-mentioned various components are mixed well in an aqueous magnesium chloride solution and then stirred well, and then a foaming agent is added. Examples of foaming agents include hydrogen peroxide (concentration 35% by weight is preferred! /), Sodium bicarbonate that generates carbon dioxide (reacts with acids such as hydrochloric acid during foaming), and metal aluminum powder. Can be mentioned.

[0012] It is preferable that the aqueous slurry obtained by thoroughly stirring after mixing the foaming agent has a solid content strength S of 50 wt% to 65 wt%, with the remainder being water. The amount of each component in the solid content in the aqueous slurry is, for example, 90% to 95% by weight of the total amount of magnesium chloride and magnesium oxide, 0.5% to 5% by weight of the water reducing agent, It is preferable that the phosphoric acid or phosphoric acid compound is 0.1 to 5% by weight, and the foam stabilizer is 0.1 to 5% by weight. The foaming agent is preferably added in an amount of 1 to 3% by weight with respect to the magnesium chloride aqueous solution after mixing the components. Then, the aqueous slurry is stirred well, poured into a suitable formwork, allowed to stand at room temperature or, if necessary, heated to about 30 ° C to 40 ° C, and dried. Use force S to obtain magnesia cement foam.

[0013] Bubbles in the magnesia cement foam hardened material obtained by the production method of the present invention are uniform in size and usually have a long diameter of 0.2 to 2 mm, and the difference between the long diameter and the short diameter is small. Usually smaller than 0.3mm. By forming such bubbles in the cured body, even if the density of the cured body is low, excellent magnesia cement foaming with low dimensional shrinkage, excellent dimensional stability, high strength and low water absorption. A cured product is obtained.

[0014] In the method for producing a magnesia cement foam cured body of the present invention, the above-described reinforcing fiber is used. In addition to fillers and fillers, various additives can be mixed as necessary. For example, in order to increase heat insulation, inorganic lightening fillers such as glass, beads, lightweight aggregate, resin-based foam beads, silica vanolene, shirasu balloon, and expanded vermiculite can be mixed. Further, in order to increase flexibility and water resistance, latex, for example, styrene butadiene rubber, polyacrylic acid ester, ethylene vinyl acetate, polyvinyl acetate and vinyl alcohol are used as long as the fire resistance of magnesia cement is not extremely reduced. Organic resins such as methenoresenololose, unsaturated polyester, epoxy resin, and urethane resin can also be added. It is also possible to mix commonly used flame retardants, colorants, mold release agents, antifungal agents, antifreeze agents, and cryogens.

In the present invention, when the aqueous slurry described above is cured, it can be made into a cured body of various shapes depending on the use of the resulting cured body. Examples of such shapes include a board shape, a sheet shape, a column shape, a cylinder shape, and a block shape. In addition, by molding the cured body into such a shape, the resulting molded product can be used as it is for building materials such as boards, wall materials, interior materials, outer wall materials, and other building materials. May be used in combination. For example, a glass cloth or the like can be arranged on a suitable plate, and the above aqueous slurry can be poured thereon to form a board for building materials. In addition, molded products having various shapes such as a columnar shape, a block shape, a spherical shape, or a shape obtained by combining them can be obtained by a molding method such as extrusion molding or cast molding.

In particular, it is preferable to use the magnesia cement foam hardened body produced in the present invention as a board and use it for a building panel. Such a building material panel is, for example, a combination of a magnesia cement foam hardened board obtained by the production method of the present invention and at least one selected from ceramic materials, metal materials, plastic materials and wooden materials. Can be manufactured. Specifically, for example, ceramic materials such as rock wool plates, tile plates, stone plates, siding materials; metal materials such as stainless steel plates, plating steel plates, iron plates; urethane foam plates, thermoplastic resin plates, heat-resistant thermoplastic resins Plastic materials such as boards; particle boards, plywood, wooden materials such as MDF, etc., together with the magnesium cement foamed hardened board produced in the present invention, can be used for interiors or in the usual manner using adhesives, etc. An exterior building panel can be manufactured. [0016] Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. The present invention is not limited to these examples.

Example 1

Magnesium chloride hexahydrate 146. 3 g is dissolved in water 216. Og. Next, to this magnesium chloride aqueous solution, phosphoric acid 2. Og and a carboxylic acid-based water reducing agent (Rebuild SP8SB LL, manufactured by Emmenby Co., Ltd.) 4.7 g and a sulfonic acid-based water reducing agent (Cell Flow 110 manufactured by Daiichi Pharmaceutical Co., Ltd.) 37.4 g was mixed. Next, a mixture prepared by previously mixing 341.5 g of acid magnesium carbonate, 4.4 g of zinc stearate, and 3.3 g of reinforcing fiber (alkali-resistant glass fiber manufactured by Nippon Electric Glass Co., Ltd.) is added to the above magnesium chloride aqueous solution and stirred. A slurry was obtained. Further, 29.9 g of hydrogen peroxide was added to the obtained slurry and stirred, and the slurry was poured into a mold (length 220 mm × width 220 mm × 40 mm).

This was left at room temperature for a whole day and night, and further dried for 12 hours in an atmosphere of 40 ° C., and then extracted from the mold to obtain a test specimen.

Using the obtained specimen, the compressive strength and water absorption were measured according to JIS A9511. The measurement results are shown in Table 1.

[0017] Example 2

221.0 g of water to dissolve magnesium chloride hexahydrate, carboxylic acid-based water-reducing agent (Leobuild SP8SB LL, manufactured by Emmenby Corporation) 9.4 g and sulfonic acid-based water-reducing agent (Cell Flow 110, manufactured by Daiichi Pharmaceutical Co., Ltd.) 28. A specimen was obtained in the same manner as in Example 1 except that the amount was 2 g. Table 1 shows the results of measurements such as the compressive strength of this specimen.

[0018] Example 3

Magnesium chloride · 225.0 g of water to dissolve hexahydrate, carboxylic acid-based water reducing agent (Leobuild SP8SB LL manufactured by Emmenby Co., Ltd.) 14. Og and sulfonic acid-based water reducing agent (Cell Flow 110 manufactured by Daiichi Pharmaceutical Co., Ltd.) ) A specimen was obtained in the same manner as in Example 1 except that the amount was 18.7 g. Table 1 shows the results of measurements such as the compressive strength of this specimen.

[0019] Example 4

A test specimen was obtained in the same manner as in Example 1 except that the carboxylic acid-based water reducing agent was Demol EP from Kao Corporation and the sulfonic acid-based water reducing agent was Demol N from Kao Corporation. this Table 2 shows the measurement results such as the compressive strength of the specimen.

[0020] Example 5

A test specimen was obtained in the same manner as in Example 2, except that the carboxylic acid-based water reducing agent was Demol EP from Kao Corporation and the sulfonic acid-based water reducing agent was Demol N from Kao Corporation. Table 2 shows the results of measurements such as compressive strength of this specimen.

[0021] Comparative Example 1

Magnesium chloride · 211.0 g of water to dissolve hexahydrate, without using carboxylic acid-based water reducing agent (Lemu build SP8SB LL manufactured by Emmenby Co., Ltd.), sulfonic acid-based water reducing agent (Cell Flow 110 manufactured by Daiichi Pharmaceutical Industry Co., Ltd.) 47. A specimen was obtained in the same manner as in Example 1 except that Og was used. Table 1 shows the results of measurements such as the compressive strength of this specimen.

[0022] Comparative Example 2

Magnesium chloride · 300.0 g of water to dissolve hexahydrate, carboxylic acid-based water reducing agent (Rheobuild SP8SB LL, manufactured by Emmenby Co., Ltd.) 18.8 g and sulfonic acid-based water reducing agent (Cell Flow 110, manufactured by Daiichi Pharmaceutical Co., Ltd.) ) A specimen was obtained in the same manner as in Example 1 except that the amount was 4 g. Table 1 shows the results of measurements such as the compressive strength of this specimen.

[0023] Comparative Example 3

A test specimen was obtained in the same manner as in Comparative Example 1 except that the carboxylic acid-based water reducing agent was Demol EP from Kao Corporation and the sulfonic acid-based water reducing agent was Demol N from Kao Corporation. Table 2 shows the results of measurements such as compressive strength of this specimen.

[0024] [Table 1]

[] 0052

[0026] As is apparent from Tables 1 and 2, the magnesia cement foam cured product obtained by the present invention has a small difference between the major axis and the minor axis where the bubble size is small, and the compressive strength is small even when the density is small. It is excellent in water absorption, and it is also excellent!

[0027] Example 6

A slurry was obtained in the same manner as in Example 1, and a magnesia cement board having a thickness of 20 mm was produced. Next, the produced magnesia cement board was cut and cut to a width of 80 mm to produce a magnesia cement board having a thickness of 20 mm and a width of 80 mm.

A set of stainless steel plates that have been processed in advance to become the front and back materials of building material panels (Thickness 0.5 mm) was prepared. One of the set of stainless steel plates (hereinafter referred to as stainless steel plate A) can be fitted after the flat plate force S, and the other (hereinafter referred to as stainless steel plate B) can be fitted after both sides in the length direction are used as building material panels. A fitting part is formed. The fitting part has a substantially convex shape in which one side of the lengthwise sides protrudes from the central part in the thickness direction of the building material panel, and the remaining side has a substantially concave shape with a groove into which a substantially convex protruding part can be fitted. is there.

The above-mentioned magnesia cement board cut so as to be in contact with the inside of both sides in the length direction of the stainless steel plate B was arranged so that the width direction of the magnesia cement board was the thickness direction of the building material panel.

Next, an adhesive was applied to a portion of the stainless steel plate B between the two magnesia cement boards arranged on the stainless steel plate B. Further, a rock wool plate (thickness 80 mm) was inserted between the two magnesia cement boards described above and bonded to the stainless steel plate B. The space formed between the stainless steel plate B fitting and the magnesia cement board was filled with rock wool granular cotton. Adhesive was applied to the inserted rock wool plate and adhered to stainless steel plate A to produce a building material panel.

Figure 1 shows a cross-sectional view of the produced building material panel.

Example 7

A slurry was obtained in the same manner as in Example 1, and a 12 mm thick magnesia cement board was produced.

An adhesive was applied to the front and back surfaces of a urethane foam board (thickness 63 mm), and the above-mentioned magnetic cement board was bonded together to produce a composite board. Next, this composite plate was cut into a size excluding the fitting portion of a later-described Meki steel plate.

A pair of steel plates (thickness 0.4 mm) were prepared in advance so as to become the front and back materials of the building material panel. One of the pair of steel plates (hereinafter referred to as “Metsuki Steel Plate A”) is a flat plate, but the other (hereinafter referred to as “Metsuki Steel Plate B”) can be fitted after both sides in the length direction are used as building material panels. A fitting part is formed. The fitting part has a substantially convex shape with one of the two sides in the length direction protruding from the central part in the thickness direction of the building material panel, and the other side having a substantially concave shape with a groove into which a substantially convex protruding part can be fitted. It is.

Next, an adhesive was applied to the inside of the location excluding the fitting portion of the steel plate B. In addition, turn off The cut composite plate was bonded to the portion of the steel plate B where the adhesive was applied. Rock wool granular cotton was filled into the space formed between the mating part of the steel plate B and the composite plate. Adhesive was applied to the inserted composite sheet, and it was bonded to Metsuki Steel Sheet A to produce a building material panel.

Fig. 2 shows a cross-sectional view of the produced building material panel.

Industrial applicability

[0029] According to the present invention, even when the cell size is uniform and small, and the density of the cured body is low, an excellent magnetic cement having a small dimensional shrinkage ratio, excellent dimensional stability, high strength, and low water absorption. A foam hardened body is obtained. This magnesia cement foam hardened body can be widely used in building materials by forming it into a board, sheet, column, block, etc. In particular, it can be suitably used for producing a building material panel.

Brief Description of Drawings

FIG. 1 shows a cross-sectional view of a building material panel produced in Example 6.

FIG. 2 shows a cross-sectional view of a building material panel produced in Example 7.

Explanation of symbols

[0031] 1 Stainless steel sheet A

2 Stainless steel plate B

3 Approximate convex shape of mating part

4 Approximate concave shape of mating part

6 Rock unole plate

7 Rock wool granular cotton

8 Urethane foam

9 Metsuki steel plate A

10 Metsuki Steel B

Claims

The scope of the claims

[I] A method for producing a foamed cured magnesia cement, which is prepared by preparing an aqueous solution of magnesium chloride, mixing a water reducing agent and magnesium oxide into the aqueous solution, then adding the foaming agent and stirring to prepare an aqueous slurry. When the resulting aqueous slurry is cured to produce a magnesia cement foamed cured product, magnesium oxide and magnesium chloride are used in a molar ratio of 7 to 13: 1; and a carboxylic acid-based water reducing agent as a water reducing agent. Method for producing foamed cured magnesia cement, characterized in that a hardened body having a uniform cell size is obtained by using an agent and a sulfonic acid-based water reducing agent in a weight ratio of 1: 5 to 2: 1. .

[2] The process according to claim 1, wherein the major axis of the bubble is 0.2 mm to 2 mm, and the difference between the major axis and the minor axis is 0.3 mm or less.

[3] The method according to claim 1 or 2, wherein magnesium oxide and magnesium chloride are used in a molar ratio of 9 to 13: 1.

[4] Carboxylic acid-based water reducing agent and sulfonic acid-based water reducing agent are used at a weight ratio of 1: 4, et al., 3: 2.

The manufacturing method according to any one of claims 1 to 3, which is V.

[5] The production method according to any one of claims 1 to 4, wherein phosphoric acid or a phosphoric acid compound is mixed in an aqueous solution of magnesium chloride.

[6] The production method according to any one of claims 1 to 5, wherein a foam stabilizer is used together with the foaming agent.

[7] The process according to any one of claims 1 to 6, wherein when preparing the aqueous solution of magnesium chloride, the solid content concentration of magnesium chloride is S, and is 10 wt% to 20 wt%.

[8] The production method according to any one of claims 1 to 7, wherein the solid content concentration of the aqueous slurry is 50 wt% to 65 wt%.

[9] The method according to any one of [1] to [8], wherein magnesium chloride in which up to 50% by weight of magnesium chloride is substituted with magnesium sulfate is used.

[10] A magnesia cement foam hardened body obtained by the production method according to any one of claims 1 to 9.

[I I] A molded article comprising the magnesia cement foam hardened body according to claim 10.

12. The molded article according to claim 11, wherein the molded article is a board.

13. The molded article according to claim 12, wherein the molded article is a building material panel. [14] The molded article according to claim 13, which is a building material panel manufactured by combining at least one selected from ceramic materials, metal materials, plastic materials and wooden materials together with the magnesia cement foam cured body according to claim 10. .