Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L15/00—Chemical aspects of, or use of materials for, bandages, dressings or absorbent pads
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L101/00—Compositions of unspecified macromolecular compounds
  • C08L101/12—Compositions of unspecified macromolecular compounds characterised by physical features, e.g. anisotropy, viscosity or electrical conductivity
  • C08L101/14—Compositions of unspecified macromolecular compounds characterised by physical features, e.g. anisotropy, viscosity or electrical conductivity the macromolecular compounds being water soluble or water swellable, e.g. aqueous gels
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L15/00—Chemical aspects of, or use of materials for, bandages, dressings or absorbent pads
  • A61L15/16—Bandages, dressings or absorbent pads for physiological fluids such as urine or blood, e.g. sanitary towels, tampons
  • A61L15/22—Bandages, dressings or absorbent pads for physiological fluids such as urine or blood, e.g. sanitary towels, tampons containing macromolecular materials
  • A61L15/225—Mixtures of macromolecular compounds
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L15/00—Chemical aspects of, or use of materials for, bandages, dressings or absorbent pads
  • A61L15/16—Bandages, dressings or absorbent pads for physiological fluids such as urine or blood, e.g. sanitary towels, tampons
  • A61L15/42—Use of materials characterised by their function or physical properties
  • A61L15/48—Surfactants
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L15/00—Chemical aspects of, or use of materials for, bandages, dressings or absorbent pads
  • A61L15/16—Bandages, dressings or absorbent pads for physiological fluids such as urine or blood, e.g. sanitary towels, tampons
  • A61L15/42—Use of materials characterised by their function or physical properties
  • A61L15/60—Liquid-swellable gel-forming materials, e.g. super-absorbents
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/22—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising organic material
  • B01J20/26—Synthetic macromolecular compounds
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
  • B01J20/28014—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their form
  • B01J20/28023—Fibres or filaments
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
  • B01J20/28014—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their form
  • B01J20/28033—Membrane, sheet, cloth, pad, lamellar or mat
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J3/00—Processes of treating or compounding macromolecular substances
  • C08J3/24—Crosslinking, e.g. vulcanising, of macromolecules
  • C08J3/246—Intercrosslinking of at least two polymers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2220/00—Aspects relating to sorbent materials
  • B01J2220/40—Aspects relating to the composition of sorbent or filter aid materials
  • B01J2220/44—Materials comprising a mixture of organic materials
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2300/00—Characterised by the use of unspecified polymers
  • C08J2300/14—Water soluble or water swellable polymers, e.g. aqueous gels
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
  • G02B6/4401—Optical cables
  • G02B6/4429—Means specially adapted for strengthening or protecting the cables
  • G02B6/44384—Means specially adapted for strengthening or protecting the cables the means comprising water blocking or hydrophobic materials
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T442/00—Fabric [woven, knitted, or nonwoven textile or cloth, etc.]
  • Y10T442/60—Nonwoven fabric [i.e., nonwoven strand or fiber material]
  • Y10T442/637—Including strand or fiber material which is a monofilament composed of two or more polymeric materials in physically distinct relationship [e.g., sheath-core, side-by-side, islands-in-sea, fibrils-in-matrix, etc.] or composed of physical blend of chemically different polymeric materials or a physical blend of a polymeric material and a filler material
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T442/00—Fabric [woven, knitted, or nonwoven textile or cloth, etc.]
  • Y10T442/60—Nonwoven fabric [i.e., nonwoven strand or fiber material]
  • Y10T442/674—Nonwoven fabric with a preformed polymeric film or sheet
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T442/00—Fabric [woven, knitted, or nonwoven textile or cloth, etc.]
  • Y10T442/60—Nonwoven fabric [i.e., nonwoven strand or fiber material]
  • Y10T442/68—Melt-blown nonwoven fabric
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T442/00—Fabric [woven, knitted, or nonwoven textile or cloth, etc.]
  • Y10T442/60—Nonwoven fabric [i.e., nonwoven strand or fiber material]
  • Y10T442/681—Spun-bonded nonwoven fabric
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T442/00—Fabric [woven, knitted, or nonwoven textile or cloth, etc.]
  • Y10T442/60—Nonwoven fabric [i.e., nonwoven strand or fiber material]
  • Y10T442/699—Including particulate material other than strand or fiber material

Definitions

• the present invention relates to a thermoplastic polymer blend composition comprising a superabsorbent polymer and method of preparation thereof.
• Superabsorbent polymers are well-known materials that are used in a variety of applications ranging from personal care articles such as diapers to water barrier applications in the construction industry to water blocking agents in communications cables to liquid absorbers in food packaging systems. These polymers are known to absorb several times their weight of, for example, moisture, water, saline solution, urine, blood, serous body fluids and the like.
• Mixtures of superabsorbent polymers and binders are characterized by a number of disadvantages and/or limitations, such as manufacturing and operating temperature limitations, lack of adhesion to the substrates to which the mixture is applied, and delaminating when the article is pulled in the tensile direction, that contribute to abrasion when the article is being fabricated and the like. Further, tapes add additional components in the construction of cables causing considerable unwanted increases in their costs and diameters. Cables using filler gels are characterized by a number of disadvantages and/or limitations such as manufacturing and operating temperature limitations, formation of voids which lead to paths of water migration, and difficulties meeting industry standards.
• films and laminates of superabsorbent polymers have been made from solutions of superabsorbent polymers followed by heating and/or removing the solvent.
• cross-linked superabsorbent polymer films and laminates see U.S. Pat. Nos. 3,926,891, 4,076,673 and 4,117,184.
• non-cross-linked superabsorbent polymer films see U.S. Pat. Nos. 3,935,099, 3,997,484 and 4,090,013.
• U.S. Pat. No. 3,669,103 describes a method to make thin foamed polyurethane thermoset sheet comprising superabsorbent polymer particles. Unfortunately, these methods of forming films, laminates and sheet are impractical for large-scale commercial use.
• the present invention is such a composition. It is a thermoplastic superabsorbent polymer blend composition comprising (a) a superabsorbent polymer (b) a thermoplastic resin and optionally (c) a surfactant wherein components (a) and (b) interact with each other ionically or covalently and the blend composition can be formed by extrusion, for example, into film, sheet, laminates, foams, profiles and injection molded articles.
• the present invention is a process for preparing the abovementioned extrudable thermoplastic superabsorbent polymer blend composition.
• the present invention involves a method of extruding or molding the abovementioned extrudable thermoplastic superabsorbent polymer blend composition.
• the invention involves extruded (e.g., film, sheet, foam, laminates, and the like) or molded articles of the abovementioned extrudable thermoplastic superabsorbent polymer blend composition.
• the invention involves articles comprising extruded or molded articles of the abovementioned extrudable thermoplastic superabsorbent polymer blend composition.
• blend compositions and extruded and molded articles of the present invention may be employed in a wide variety of uses as are known in the art, such as, for example, the assembly or construction of cable wrap components and various disposable absorbent articles, such as sanitary napkins, disposable diapers, hospital gowns, bed pads and the like.
• the superabsorbent water-swellable or lightly cross-linked hydrophilic polymers suitably employable in the present invention can be any of the known hydrophilic polymers that are capable of absorbing large quantities of fluids. These polymers are well known in the art and are widely commercially available.
• Preferred superabsorbent polymers are prepared from water-soluble ⁇ , ⁇ -ethylenically unsaturated monomers such as monocarboxylic acids, vinyl polycarboxylic acids, acrylamide and their derivatives. More preferred superabsorbent polymers are cellulosic or starch-graft copolymers, such as starch-g-poly(acrylonitrile), starch-g-poly(acrylic acid) and the like; polyacrylamides; polyvinyl alcohols; poly(acrylic acids); high molecular weight polymers, preferably cross-linked, of ethyleneoxide (EO) and propyleneoxide (PO); copolymers of sulfonic acid group containing monomers, such as vinyl sulfonic acid, sodium sulfoethyl methacrylate, 2-Acrylamido-2-Methylpropane-sulfonic acid or the sodium salt (AMPS) and the like.
• EO ethyleneoxide
• PO propyleneoxide
• Most preferred superabsorbent polymers are crosslinked, partially neutralized and/or surface treated.
• the level of crosslinking is selected to give the desired swelling characteristics for the particular application.
• the degree of neutralization is from about 30 to about 100 percent, more preferably from about 50 to about 80 percent.
• a preferred surface treatment consists of a post polymerization reaction to effect the surface crosslinking of the superabsorbent polymer.
• the amount of the superabsorbent polymer to be included in the thermoplastic superabsorbent polymer blend composition according to the present invention will vary depending, for example, upon the type of superabsorbent polymer used, the type of thermoplastic resin used, the desired extruded or molded product, the extruded or molded product's end use application, the desired level of blocking, absorbing or stopping the migration of water and/or other fluids in the end use application, etc.
• the superabsorbent polymer is present in an amount equal to or greater than about 1 part per weight, preferably equal to or greater than about 5 parts per weight, more preferably equal to or greater than about 10 parts per weight, even more preferably equal to or greater than about 15 parts per weight and most preferably equal to or greater than about 20 parts per weight based on the weight of the thermoplastic superabsorbent polymer blend composition.
• the amount of superabsorbent polymer is present in an amount equal to or less than about 70 part per weight, preferably equal to or less than about 65 parts per weight, more preferably equal to or less than about 60 parts per weight, even more preferably equal to or less than about 55 parts per weight and most preferably equal to or less than about 50 parts per weight based on the weight of the thermoplastic superabsorbent polymer blend composition.
• the blend composition of the present invention contains at least one thermoplastic resin that interacts (i.e., ionically, covalently, etc.) with the superabsorbent polymer.
• a thermoplastic resin having an acyl groups which can undergo nucleophilic attack resulting in a substitution reaction in which a leaving group, such as —OH, —Cl, —OOCR, —NH2 or —OR is replaced by another basic group present in the superabsorbent polymer.
• a thermoplastic resin containing carbonyl groups that can undergo a nucleophilic attack gaining a proton and adding another basic group present in the superabsorbent polymer. Under these conditions the reaction product of the thermoplastic resin and superabsorbent polymer may form a uniform and/or co-continuous non-separating polymer blend.
• thermoplastic resins have functional groups such as acyl or carbonyl groups (e.g., ⁇ , ⁇ -unsaturated carbonyl compounds, hydroxy acids, dicarboxylic acids, keto acids, anhydrides, carboxylic acids, aldehydes, ketones, acid halides, esters, amides, etc.), sulfonyls, sulfonyls halides, ethers, phenols, aryl halides, epoxides, carbohydrates, alcohols, azides, amines and the like.
• acyl or carbonyl groups e.g., ⁇ , ⁇ -unsaturated carbonyl compounds, hydroxy acids, dicarboxylic acids, keto acids, anhydrides, carboxylic acids, aldehydes, ketones, acid halides, esters, amides, etc.
• sulfonyls e.g., sulfonyls
• the preferred thermoplastic resins are acrylic polymers, with polyacrylic acid (PAA), ethylene and acrylic acid copolymers (EAA), ethylene, t-butylacrylate and acrylic acid terpolymer (EtBAAA), ethylene and methacrylic acid copolymers (EMAA), ionomers of ethylene and methacrylic acid copolymers especially the sodium and zinc ionomers, ethylene, vinyl acetate and carbon monoxide terpolymers (EVACO), ethylene and carbon monoxide copolymers (ECO), ethylene, acrylic acid and carbon monoxide terpolymers (EAACO), ethylene, n-butylacrylate and carbon monoxide terpolymers (EnBACO) and blends thereof being most preferred.
• PAA polyacrylic acid
• EAA ethylene and acrylic acid copolymers
• EtBAAA ethylene
• EtBAAA t-butylacrylate and acrylic acid terpolymer
• EEMAA ethylene and meth
• the most preferred thermoplastic resins are 1) an EAA copolymer, wherein the EAA copolymer may be a blend of two or more EAA copolymers, preferably having a composition from about 10 to about 20 weight percent acrylic acid based on the weight of the copolymer and a melt flow rate (MFR) from about 100 to about 200 grams per 10 minutes (g/10 min.) under conditions of 190° C. and an applied load of 2.16 kg., 2) ionomers of EMAA, preferably the zinc ionomer, 3) EVACO, preferably having a carbon monoxide content of at least 9 percent based on the weight of the terpolymer or 4) blends thereof.
• MFR melt flow rate
• thermoplastic resin is present in an amount equal to or greater than about 30 part per weight, preferably equal to or greater than about 35 parts per weight, more preferably equal to or greater than about 40 parts per weight, even more preferably equal to or greater than about 45 parts per weight and most preferably equal to or greater than about 50 parts per weight based on the weight of the thermoplastic superabsorbent polymer blend composition.
• the amount of thermoplastic resin is present in an amount equal to or less than about 99 parts per weight, preferably equal to or less than about 95 parts per weight, more preferably equal to or less than about 90 parts per weight, even more preferably equal to or less than about 85 parts per weight and most preferably equal to or less than about 80 parts per weight based on the weight of the thermoplastic superabsorbent polymer blend composition.
• thermoplastic resins e.g., EAA/EVACO, EMAA/EAA, a first EAA/a second EAA and the like.
• blend compositions of the present invention contain at least one superabsorbent polymer
• such blend compositions may or may not be superabsorbent, depending upon the level and absorbency of the superabsorbent polymer in the blend composition and the availability of the superabsorbent polymer to aqueous media.
• the blend compositions of the present invention can be further blended with other thermoplastic polymers, preferably low density polyethylene (LDPE), linear low density polyethylene (LLDPE), very low density polyethylene (VLDPE), polypropylene (PP), polystyrene (PS), ethylene and methylacrylate copolymer (EMA), ethylene and ethylacrylate copolymer (EEA), ethylene and n-butylacrylate copolymer (EnBA), polyethylene grafted with maleic anhydride grafted (PE g-MAH), ethylene and vinyl acetate copolymer (EVA), ethylene and vinyl acetate copolymer grafted with maleic anhydride grafted (EVA g-MAH), or combinations thereof.
• LDPE low density polyethylene
• LLDPE linear low density polyethylene
• VLDPE very low density polyethylene
• PP polypropylene
• PS polystyrene
• EMA ethylene and methylacrylate copolymer
• EAA
• the blend compositions of the present invention may further comprise additional additives commonly used in compositions of this type such as lubricants, extenders, compatibilizers, plasticizers, low and high molecular weight waxes, surfactants, stabilizers, pigments, carbon black and fillers such as talc, titanium dioxide (TiO 2 ), calcium carbonate (CaCO 3 ), magnesium oxide (MgO), mica and the like.
• additional additives commonly used in compositions of this type such as lubricants, extenders, compatibilizers, plasticizers, low and high molecular weight waxes, surfactants, stabilizers, pigments, carbon black and fillers such as talc, titanium dioxide (TiO 2 ), calcium carbonate (CaCO 3 ), magnesium oxide (MgO), mica and the like.
• blend compositions of the present invention may further be blended with a solvent to form a dispersion or paste.
• a solvent to form a dispersion or paste.
• One skilled in the art can readily choose the type and amount of solvent depending on the particular end use.
• the phrase “extrudable thermoplastic superabsorbent polymer blend composition” means that: (1) the blend composition is melt processable in an extrusion, injection molding and/or blow molding process, (2) the extrudate is either commuted to pellets or directly extruded or molded by extrusion fabrication technique, (3) the pellets have a measurable melt flow rate, melt draw rate and melt strength sometimes referred to as melt tension and (4) the pellets can be re-extruded by an extrusion fabrication techniques.
• the blend compositions of the present invention do not cause plugging, die-face build up, surging, melt fracture, pinholes, tearing and/or poor extrudate properties (i.e., strand dropping, delamination, etc.) during the extrusion process.
• a melt indexer is used to determine melt flow rate (MFR), melt tension and draw down rate.
• MFR is determined by ASTM D 1238; the run conditions (i.e., temperature and applied load) depend upon the thermoplastic resin used.
• Melt tension is determined from a load cell attached at the bottom of the melt indexer which measures the load required to pull the extrudate from the die of the melt indexer to a take up reel at some given speed measured in feet per minute (fpm).
• the draw down rate (fpm) is determined by how fast the extrudate coming out of the melt indexer can be pulled before it breaks.
• MFR conditions are selected to give a MFR between about 0.1 and about 300 g/10 min.
• the thermoplastic superabsorbent polymer blend composition has a melt draw down rate between about 5 and about 100 fpm and a melt tension between about 0.1 and about 10.
• the components of the extruded blend composition can be co-continuous or separate phases (one being continuous and one or more being dispersed therein) as long as phase separation does not have a significant deleterious effect on the melt processability or performance of the blend composition.
• Preferred extrusion fabrication techniques include preparing melt blown or cast films; extrusion coating; (co)extruding nonwoven webs, including spun bond nonwoven webs, melt blown nonwoven webs, or composites comprising combinations thereof, sheets, foams, profiles, multilayer laminates, fibers including monofilament fibers and bicomponent monofilament fibers, tubes, rods or pipes; blow molding articles; injection molding articles (including solid, co-injection, structural foam and gas assist injection molding).
• Preferred nonwoven webs comprise spun bond nonwoven webs comprising one or more bicomponent fiber, melt blown nonwoven webs comprising one or more bicomponent fiber, and a composite structure comprising at least one layer of one or more spun bond nonwoven web and at least one layer of one or more melt blown nonwoven web wherein one or more layers of the composite comprise bicomponent fibers.
• thermoplastic superabsorbent polymer blend compositions of the present invention can be extruded into foam using a chemical or physical blowing agent. Further, the thermoplastic superabsorbent polymer can be blended with other miscible or compatible thermoplastic polymers such as LDPE, LLDPE, VLDPE, PP, PS, EEA, EMA, ENBA, PE g-MAH, EVA, EVA g-MAH or the like.
• One skilled in the art can choose the type and amount of blowing agent as well as other polymers to blend with the thermoplastic superabsorbent polymer for the particular end use in order to modify the cell size, structure, porosity, microcellular nature and absorbency characteristics of the thermoplastic superabsorbent polymer foam as desired.
• the blend compositions to make foam may further comprise additional additives commonly used in compositions of this type such as lubricants, extenders, nucleators, compatibilizers, plasticizers, low and high molecular weight waxes, surfactants, stabilizers, pigments, carbon black and fillers such as talc, TiO 2 , CaCO 3 , MgO, mica and the like.
• extruded pellets or sheet can be compression molded; calendered; vacuum formed or thermoformed.
• Preparation of the thermoplastic superabsorbent polymer blend compositions of this invention can be accomplished by any suitable mixing means known in the art.
• the components and any additional additives are blended in a tumbler or shaker in powder, particulate and/or pellet form with sufficient agitation to obtain thorough distribution thereof.
• the dry-blended formulation can further be subjected to shearing stresses at a temperature sufficient to heat soften and melt-mix the polymers, for example in an extruder, with or without a vacuum, or other mixing apparatuses (e.g., a Banbury mixer, roller mill, Henschel mixer, a ribbon blender, etc.).
• melt-mixed material can be extruded to make the finished article (i.e., film, sheet, foam, profile, etc.) or recovered in the form of a pellet, powder or flake, preferably a pellet.
• the extrudate may be commuted to pellets by any conventional means such as a strand chopper or an underwater die face cutter.
• the extrudate from the melt-mixing may be cooled by any method known in the art, such as air cooled, gas cooled, belt cooled, liquid cooled by passing through a liquid bath, and the like.
• a stainless steel belt cooler for example manufactured by Sandvik Process Systems, Sweden or a Compact Conti Cooler manufactured by BBA AG, Switzerland, or an aqueous liquid bath, preferably where the pH is less than 1.0 or an aqueous liquid bath with a water hardness of greater than 25 French Degrees, more preferably an aqueous liquid bath with a specific gravity greater than about 1.05 as measured with a desitometer is used.
• the aqueous bath preferably contains a saturated salt solution containing a Group 1 metal ion, preferably sodium, such as sodium chloride (NaCl), sodium sulfate (Na 2 SO 4 ), sodium bicarbonate (NaHCO 3 ) and the like.
• a Group 1 metal ion preferably sodium, such as sodium chloride (NaCl), sodium sulfate (Na 2 SO 4 ), sodium bicarbonate (NaHCO 3 ) and the like.
• Blowing cool air in the pellet-collecting vessel such as the use of a fluidized bed cooler, to drive away the remaining moisture on the pellets further improves the drying process.
• melt-mixed material can be re-extruded or molded to make the finished article.
• Dry blends of the blend compositions can also be directly injection molded or metered into another melt fabrication process without pre-melt-mixing.
• extrudable thermoplastic superabsorbent polymer blend compositions of the present invention are useful in the pellet, flake or powder form for use in cat litter, solidified gases/fluids, gelled ice, soil conditioner, frost control, agricultural delivery systems, gelled biohazards, spill control, for the fabrication of articles such as foams, such as closed, semi-porous or microcellular or open cell, bicomponent fibers and waterproof or waterblocking coating systems, thick film or sheet for such applications as disposable absorbent articles, such as sanitary napkins, disposable diapers, hospital gowns, bed pads and the like, films for such applications as moisture sensitive systems, moisture, such as water, absorbing structures, for example in packaging, transportation, construction applications and the like, diaper backing, meat trays, carpet backing or power and communication cable water-blocking tapes, film for laminate structures such as laminated foam structures, laminated non-woven structures, film for laminates for such applications as cable shielding tapes for use in power cables or communication cables, such as fiber optical cables, copper pair cables, co
• a cable structure comprising an extrudable thermoplastic superabsorbent polymer blend composition resists penetration, sometimes referred to as water blocking, of water through the cable in the longitudinal direction.
• thermoplastic resins are melt blended in a Brabender Plasticoder with CABLOCTM 850-13 a sodium polyacrylate superabsorbent polymer that is surface cross-linked having a particle size distribution of about 1 to about 300 micrometers available as a powder from Stockhausen and supplied by the Stewart Superabsorbents LLC. Unless otherwise noted, the ratio of superabsorbent polymer to thermoplastic resin is 40:60.
• the Brabender Plasticoder conditions are: Barrel temperature ranging from 275 to 420° F. depending on the thermoplastic resin being used; Mixing revolutions per minute (RPM) are 80; and Mixing times range from 1.5 to 2 minutes.
• a melt indexer is used to determine the melt flow rate, melt tension and melt draw down rate of the polymer blends
• Table 1 lists the compositions for Comparative Examples A to ZZ and Examples 1 to 13 and their properties.
• blend compositions which can be melt blended in some fashion and pressed into a shape or molded into a sheet or an article, but do not meet the criteria set forth herein as extrudable are designated not extrudable.
• Comparative Examples AB to AN and Examples 14 to 17 are compounded on a WP ZK30 twin screw extruder.
• the SAP and the polymer are fed separately into the feed section of the extruder, the vent port of the extruder is open to the atmosphere and the extrudate is air-cooled.
• compositions of Comparative Examples AB to AN and Examples 14 to 17 and extruder temperatures are given in Table 2, the superabsorbent polymer is present in parts by weight based on the weight of the thermoplastic superabsorbent polymer blend composition.
• compositions that demonstrate die face build-up and/or plugging are designated “not” extrudable.
• Ethylene-Styrene Interpolymer G 4.75 No OO ESI DS 201 Dow Chemical Co.
• Ethylene-Styrene Interpolymer G 5.6 No PP ELVAX TM 3180 DuPont EVA, 28% VA E 13.68 No QQ ELVAX VOW DuPont EVA, 49% VA B 1.5 No RR GRILTEX TM 9 EMS Am. Grilon, Inc CoPolyester hot melt adhesive C 4.4 No SS GRILTEX D EMS Am.
• Comparative Examples AO to AW are different neat thermoplastic resins
• Comparative Example AU is neat superabsorbent polymer CABLOC 850-13
• AV is the neat superabsorbent polymer CABLOC 80HS
• AW is the neat superabsorbent polymer CABLOC 88HS
• Examples 18 to 30 are different thermoplastic resins compounded with a superabsorbent polymer.
• a ZSK 58 millimeter (mm) co-rotating bi-lobe twin screw extruder having a low shear mixing screw and 10 temperature zones is used.
• the superabsorbent polymer is fed using a side port powder screw feeder between zones 4 and 5. Mixing occurs in zone 6.
• the transition point between zone 8 and 9 is the vent port.
• the temperature range for the first 3 zones is from 65 to 120° F., for zones 4 and 5 it is from 240 to 255° F., for zones 6 to 8 it is from 320 to 335° F. and for zones 9 and 10 it is from 270 to 330° F.
• the melt temperature is maintained at 310° F.
• the blend compositions are extruded through a 24 hole underwater die having hole diameters of 0.110 inch into a liquid bath containing a NaHCO 3 solution having a specific gravity of greater than 1.05 as measured with a desitometer with a temperature maintained below 20° C.
• a Gala underwater pelletizer with 3 cutting blades is used to pelletize the extrudate.
• the distance from the underwater pelletizer to the separating dryer is optimized to minimize the adsorption of water. Further, cool air is blown on the pellets in the pellet-collecting vessel driving away any remaining moisture on the pellets.
• thermoplastic superabsorbent polymer blend compositions a sample determined to contain 1 gram of the superabsorbent polymer (based on the percent superabsorbent polymer in the blend composition) weighing W 1 is placed in 1.5 liter of distilled water and is shaken on a shaker for 2 hours. The water is filtered from the swollen particles through a 75 micrometer sieve. The weight of the swollen particles (W 2 ) is then measured. The amount of water absorbed, W a , is W 2 -W 1 .
• WAC pure water
• thermoplastic superabsorbent polymer is melt blended in a Brabender Plasticoder with a 70:30 LLDPE:LDPE polymer blend.
• the thermoplastic superabsorbent polymer comprises 40 weight percent CABLOC T5066-F which is a sodium polyacrylate superabsorbent polymer that is surface cross-linked having a particle size distribution of about 1 to about 60 micrometers available as a powder from Stockhausen and supplied by the Stewart Superabsorbents LLC and 60 weight percent of a 50:50 PRIMACOR 5980:PRIMACOR 3460 polymer blend.
• the Brabender Plasticoder conditions are: Barrel temperature is set at 275° F.; Mixing RPM is 80; and Mixing times range from 1.5 to 2 minutes.
• a melt indexer is used to determine the melt flow rate, melt tension and melt draw down rate of the polymer blends.
• the blend compositions are considered extrudable.
• the compositions of Examples 31 to 38 and their MFR, melt tension and draw rates are given in Table 4.
• Examples 39 to 42 are monolayer films of thermoplastic superabsorbent polymer blend compositions produced using a cast line process.
• the thermoplastic superabsorbent polymer blend compositions comprise a thermoplastic resin and CABLOC 850-13.
• the temperature zones for the cast film process range from 250° F. to 320° F.
• the feedblock and die temperatures range from 270° F. to 320° F. Smooth to textured uniformed film having a thickness greater than 6.0 mils or web film having a thickness less than 6.0 mils can be made depending on the take up speed.
• compositions and properties of monolayer films Examples 39 to 42 are shown in Table 5, the superabsorbent polymer is present in parts by weight based on the weight of the thermoplastic superabsorbent polymer blend composition. Absorption capacity in pure water was determined by as described hereinabove. TABLE 5 CABLOC Example Thermoplastic Resin 850-13, parts Water Absorption, g 39 SURLYN 1702 35 25 40 SURLYN 1702 45 226 41 PRIMACOR blend (a) 40 219 42 ELVALOY EP4924 40 238
• Examples 43 to 46 are mono layer films containing a surfactant.
• the thermoplastic superabsorbent polymer is melt blended in a Brabender Plasticoder with a commercially available polyethylene containing surfactant compound.
• the polyethylene containing surfactant is available from AMPACET as ANTIFOG PE MB and contains 10 weight percent active surfactant, mono- and di- glycerides, in a LLDPE/LDPE base polymer.
• the thermoplastic superabsorbent polymer comprises 40 weight percent CABLOC T5066-F a sodium polyacrylate superabsorbent polymer that is surface cross-linked having a particle size distribution of about 1 to about 60 micrometers available as a powder from Stockhausen and supplied by the Stewart Superabsorbents LLC and 60 weight percent of a 50:50 PRIMACOR 5980:PRIMACOR 3460 polymer blend.
• the Brabender Plasticoder conditions are: Barrel temperature is set at 275° F.; Mixing RPM is 80; and Mixing times range from 1.5 to 2 minutes. Water absorption and rate of absorption is measured by placing a 2 inch disc sample of a 5 to 7 mil compression molded film in a 2 inch diameter cylinder.
• a fine mesh screen that is 75 micronmeter or less.
• a Teflon disk is placed on top of the film sample to secure it in place during the testing.
• the cylinder containing the sample is placed on top of 4 inch glass fret so that the film sample and screen faced the glass fret.
• a filter paper is placed between the cylinder and the glass fret.
• the glass fret, filter and the cylinder is placed in a container that contains water so that the height of the water reaches the height of the glass fret. The water continuously being removed and replenished. The entire set up sits on a Mettler PG3001-S balance.
• Comparative Examples AX to AZ and Examples 47 to 49 are multilayer films of thermoplastic superabsorbent polymer blend compositions produced using a blown film process.
• the extruder temperature zones for the thermoplastic superabsorbent polymer blend composition (layer 1) range from 250° F. to 300° F.
• the extruder temperature zones for layers 2 and 3 range from 250° F. to 400° F.
• die temperatures range from 250° F. to 400° F.
• Table 7 The compositions and descriptions of multilayer blown film Comparative Examples AX to AZ and Examples 47 to 49 are shown in Table 7.
• Examples 50 to 53 are multilayer blown films prepared as described herein above wherein the level of CABLOC 850-13 is varied in a PRIMACOR blend resin while the composition and ratios of layers 2 and 3 are kept constant.
• the absorption capacity as described hereinabove and the time to gel block in pure water is determined.
• the time for the superabsorbent polymer to gel the water at its absorption capacity in pure water for the superabsorbent films, referred to as gel block is measured according to the following procedure.
• a sample of the thermoplastic superabsorbent film composition comprising 0.15 gram of superabsorbent polymer in a vial containing 25.6 grams of distilled water. The mixture was shaken by hand until it was gel blocked.
• the swell initiation time is the time from when the water is added to the first observable swelling of the superabsorbent polymer.
• Table 8 lists the compositions and film gauge for multilayer films Comparative Example AAA and Examples 50 to 53.
• Table 9 lists the water absorption, swell initiation time and time to gel block properties for multilayer films Comparative Examples AAA and Examples 50 to 53 and neat CABLOC 850-13 (Comparative Example AAB). TABLE 7 Exam- Com. Layer ratio Gauge ple Ex.
• Examples 54 to 57 use a 2.0 mil multilayer blown film.
• the multilayer film comprises as layer 1 a thermoplastic superabsorbent polymer blend comprising 60 weight percent of a 50:50 blend of PRIMACOR 3460/PRIMACOR 5980 and 40 weight percent CABLOC T5066 F, as layer 2 a LDPE 4005 and as layer 3 PLEXAR 107 an EVA g-MAH from Equistar.
• the extruder temperature zones for the thermoplastic superabsorbent polymer blend composition (layer 1) range from 250° F. to 300° F.
• the zone temperatures for layer 2 range from 305° F. to 310° F.
• the zone temperatures for layer 3 range from 350° F. to 370° F.
• the thickness ratio for layers 1:2:3 is 30:50:20.
• Layer 1 the thermoplastic superabsorbent layer, of the multilayer film is sprayed with a surfactant solution ranging from 0 to 8 percent surfactant.
• the surfactant used for the study is an alcohol ether sulfate. After the film is sprayed, it is placed in an air circulating oven to dry at a temperature of 50° C. for 1-2 minutes. Water absorption and rate of absorption is measured according to procedures in the aforementioned section. Table 10 summarizes the water absorption amounts and rates for Examples 54 to 57.
• Example 58 is the multilayer film described in Example 53 laminated to 6.0 mils Electrically Chrome Coated Steel (ECCS) via a heat lamination process.
• the adhesive layer of the film (layer 3) is used to bond the film to the steel surface.
• the superabsorbent film/metal laminate can find usefulness in power cable and communication cable construction.
• the metallic substrate can provide shielding and the thermoplastic superabsorbent polymer layer can be used to bond to itself or another substrate and can function to stop, block and absorb water in cables.
• Table 11 shows the adhesion properties for Example 57 superabsorbent film and metal laminate. TABLE 11 Peel Strength (a), Heat Seal (a) Jacket (b) Bond Example Film Metal Type (lb/in) Strength, (lb/in) Strength, (lb/in) 58
• Example 53 ECCS 5.0 13.1 31.8
• thermoplastic superabsorbent polymer laminate (Examples 59 to 62, Table 12) is compared to cables comprising ZETABON CJBS262 armor tape available from the Dow Chemical Company (Comparative Example AAC) and additionally comprising a non-woven superabsorbent tape 3E252 produced by Lantor Inc. (Comparative Example AAD).
• Non-woven superabsorbent tapes are the wire and cable industry standard for use in dry cable designs.
• the non-woven superabsorbent tape comprises superabsorbent particles sandwiched between two non-woven materials.
• the non-woven superabsorbent tape is helically wrapped around the copper pair cable core before placing the cable core inside the formed armor tape.
• the non-woven superabsorbent tape is typically longitudinal formed around the cable core.
• Water blocking performance of the cables is determined by the EIA/TIA-455-82A (“L-test”).
• the end of the cable core is taped or sealed so that water can not migrate through the wires of the cable core.
• the cable length is 1 meter
• test duration is 24 hours
• the water column is 1 meter and time to penetration is measured.
• Superabsorbent films were laminated to the ECCS.
• the superabsorbent layer of the film is either pre- or post-coated with an alcohol ether sulfate surfactant solution.
• concentration of the surfactant solution ranges from 2 weight percent to 8 weight percent.
• An antifoaming agent, Dow Coming Anti Foam 1520-US, is also used.
• the amount of antifoam used is 2500 ppm.
• the coated laminate is slit into 1.375 inch wide steel tape.
• the tape is used to make armored cables Examples 63 to 68 (Table 13).
• the steel tape is corrugated to 32 corrugations per inch (corrugation can be achieved with or without oil).
• the corrugated tape is longitudinal formed through a series of forming dies.
• An HDPE core tube available from United States Plastic Corporation, having an outside diameter of 0.375 inch is placed inside the formed armored tape.
• a jacketing resin is then extruded onto the formed armor tape to make a final cable.
• the final gap between the inner jacket and the armor tape is calculated to be around 0.020 inch (0.508 mm).
• thermoplastic superabsorbent polymer laminate (Examples 63 to 68) is compared to cables comprising ZETABON CJBS262 armor tape available from the Dow Chemical Company (Comparative Example AAC).
• Examples 69 to 77 are extruded foams of thermoplastic superabsorbent polymer blend compositions. About 12 parts per hundred (pph) HCFC 142B physical blowing agent is used. The extruder temperature zones range from 110° C. to 150° C. and the die temperature range from 85° C. to 90° C. The compositions and description of the foam are shown in Table 14. The resulting foams are soft, flexible and non-friable. The superabsorbent particulates are uniformly distributed on the skin and throughout the cell structure of the foam.
• the absorption capacity in pure water (WAC) of thermoplastic superabsorbent foam Examples 78 to 80 (Table 15) extruded by the abovementioned extrusion foam process is shown in Table 16.
• the WAC is measured according to the following procedure: the foam is cut in 0.125 inch by 0.625 in by 0.1.25 to 0.25 inch and an amount of the cut foam sample determined to contained 0.1 gram of the superabsorbent polymer (based on the percent superabsorbent polymer in the foam composition) weighing W1 is placed in 0.150 liter of distilled water and is shaken on a shaker for 2 hours. The water is filtered from the foam through a 75 micrometer sieve. The weight of the swollen foam (W2) is then measured. The amount of water absorbed, (Wa) is calculate by the following formula:
• thermoplastic superabsorbent polymer blends of the present invention comprising one or more superabsorbent polymer and one or more thermoplastic resin wherein the thermoplastic resin comprises a functional group that interacts with the superabsorbent polymer yields the best balance of superabsorbent polymer containment, processability, formability and absorption properties.
• the present invention provides improved thermoplastic superabsorbent polymer blend compositions and processes for preparing, among other things, monolayer films, multilayer films, nonwoven webs, sheets, foams, profiles, multilayer laminates, fibers, tubes, rods, pipes and the like. It can be seen that the resulting parts or structures according to the present invention are surprisingly improved by the use of the described extrudable thermoplastic superabsorbent polymer blend compositions and that extruded, shaped or otherwise fabricated articles will ease manufacture, improve performance and reduce costs of absorbent articles constructed therefrom.

Landscapes

• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Materials Engineering (AREA)
• Animal Behavior & Ethology (AREA)
• Veterinary Medicine (AREA)
• Public Health (AREA)
• General Health & Medical Sciences (AREA)
• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Epidemiology (AREA)
• Analytical Chemistry (AREA)
• Hematology (AREA)
• Dispersion Chemistry (AREA)
• Polymers & Plastics (AREA)
• Medicinal Chemistry (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Laminated Bodies (AREA)
• Absorbent Articles And Supports Therefor (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)
• Orthopedics, Nursing, And Contraception (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=22823899

Family Applications (1)

Country Status (11)

Cited By (67)

Families Citing this family (23)

Citations (10)

Family Cites Families (7)

• 2001
  • 2001-07-11 CZ CZ2003176A patent/CZ2003176A3/cs unknown
  • 2001-07-11 AU AU2453102A patent/AU2453102A/xx active Pending
  • 2001-07-11 CA CA2414197A patent/CA2414197C/fr not_active Expired - Fee Related
  • 2001-07-11 JP JP2002513523A patent/JP2004504446A/ja active Pending
  • 2001-07-11 IL IL15402901A patent/IL154029A0/xx unknown
  • 2001-07-11 WO PCT/US2001/021869 patent/WO2002007791A2/fr active IP Right Grant
  • 2001-07-11 KR KR10-2003-7001015A patent/KR20030031129A/ko not_active Abandoned
  • 2001-07-11 US US09/903,362 patent/US20020039869A1/en not_active Abandoned
  • 2001-07-11 EP EP01984308A patent/EP1311620A2/fr not_active Withdrawn
  • 2001-07-11 MX MXPA03000200A patent/MXPA03000200A/es active IP Right Grant
  • 2001-07-11 AU AU2002224531A patent/AU2002224531B2/en not_active Ceased
  • 2001-07-11 CN CNB018129269A patent/CN1180032C/zh not_active Expired - Fee Related
• 2003
  • 2003-01-19 IL IL154029A patent/IL154029A/en not_active IP Right Cessation

Patent Citations (10)

Also Published As