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WO1993017066A1 - Polymeres absorbants et leur preparation - Google Patents

Polymeres absorbants et leur preparation Download PDF

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Publication number
WO1993017066A1
WO1993017066A1 PCT/GB1993/000357 GB9300357W WO9317066A1 WO 1993017066 A1 WO1993017066 A1 WO 1993017066A1 GB 9300357 W GB9300357 W GB 9300357W WO 9317066 A1 WO9317066 A1 WO 9317066A1
Authority
WO
WIPO (PCT)
Prior art keywords
water
silica
polymer
particles
process according
Prior art date
Application number
PCT/GB1993/000357
Other languages
English (en)
Inventor
Ian Michael Johnson
Original Assignee
Allied Colloids Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GB929203594A external-priority patent/GB9203594D0/en
Application filed by Allied Colloids Limited filed Critical Allied Colloids Limited
Publication of WO1993017066A1 publication Critical patent/WO1993017066A1/fr

Links

Classifications

    • 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
    • C08J3/12—Powdering or granulating
    • 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
    • A61L15/18—Bandages, dressings or absorbent pads for physiological fluids such as urine or blood, e.g. sanitary towels, tampons containing inorganic materials
    • 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
    • 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
    • C08J3/12—Powdering or granulating
    • C08J3/16—Powdering or granulating by coagulating dispersions
    • 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

Definitions

  • This invention relates to aggregates of water swellable polymeric material.
  • water insoluble, water swellable, particulate polymeric materials formed from ethylenically unsaturated material wherein the polymeric material has a polymer structure that is formed of zones in which the polymer is substantially free of cross links between pendant groups in the polymer and the zones are interconnected by cross links through pendant groups in the polymer.
  • a polyvalent metal compound such as a compound of aluminium can be suitable for causing the cross linking between the polymer particles, and this will lead to ionic cross linking.
  • a suitable material for this purpose is aluminium sulphate or other polyvalent metal compound salt.
  • the cross linking compound is preferably one that leads to covalent cross linking and various hydroxy-containing and silane compounds are described for this purpose.
  • the technique is particularly valuable because it is capable of converting polymer fines into useful, coarser products, and that absorbent particles obtained in that invention, especially when the starting particles are cross linked sodium acrylate or similar particles, have particularly suitable properties when high gel capacity and high rate of absorption are required.
  • these processes are very successful for many purposes, it is sometimes found that the resulting aggregates crack or disintegrate during transport or use. It would be desirable to find a way of conducting the process, and producing products, that have satisfactorily low friability and advantageous properties from the point of view of total absorption and rate of absorption, for instance in diapers.
  • an absorbent product comprises water swellable, particulate aggregates which consist essentially of polymeric material derived from ethylenically unsaturated material and which each comprise zones of the polymeric material interconnected by linkages through an effective agglomerating amount of silica or silicate.
  • a process according to the invention for making water swellable, particulate aggregates from particles of a water swellable polymeric material derived from water soluble ethylenically unsaturated polymer comprises forming a gel mass by mixing the particles of polymeric material with water and an effective agglomerating amount of a silica or a silicate, and drying and comminuting the gel mass.
  • the mixing conditions must be such as to convert the mixture of polymer particles, water and silica or silicate to a gel mass, and if there is any tendency for the particles to remain separate it may be desirable to increase the force of mixing.
  • the gel mass may be formed in an extruder used for the comminution.
  • a mixture is formed of the polymer particles (generally in dry form) , the silica or silicate, and water.
  • the silica may be present as a suspension in water and the silicate may be present as a suspension or a solution in water, in which event the mixing stage can be conducted merely by mixing the polymer particles with the resultant aqueous suspension or solution.
  • dry particulate silica or silicate is mixed with the polymer particles generally while they are still wholly or substantially dry, and additional water is then mixed with the mixture to form the gel mass.
  • the preferred technique comprises dry mixing the polymer particles with dry silica particles, and then mixing the resultant mixture with water to form the gel mass.
  • the water that is used for mixing with the polymer particles may be a carrier for the silica or silicate.
  • the polymer contains pendant groups (e.g. carboxylic groups) the water may also contain cross linking agent that will cross link between such groups. Suitable cross linking agents are described in EP 401044, such as any of the hydroxy or epoxy or silane compounds mentioned therein as cross linking agents.
  • the silica is preferably a fumed or precipitated silica and so will have very large surface area when dispersed in water, for instance 50 to 1000 g/m and usually 100 to 750 g/m 2 .
  • the surface area is above 100 or 150 g/m , preferably above 200 g/m .
  • the particle size of the individual particles is generally below 30 ⁇ m and typically in the range 0.1 to lO ⁇ m, often below 5 ⁇ m, for instance 1 to 5 ⁇ m.
  • the silica is often supplied as aggregates, e.g. having a size of 10 to lOO ⁇ m.
  • insoluble silicates can be used although they are usually less effective.
  • the silicate is preferably silicic acid or a swelling clay, colloquially known as bentonite, which in practice is normally a smectite clay. If it is particulate, it should have small particle size and large surface area, e.g. as described above.
  • colloidal or true solutions of silicates or silicic acid may be used instead of suspensions of insoluble silicates, but again they are usually less effective than fumed or precipitated silica.
  • Sufficient water must be applied to convert the starting polymer fines to an aqueous gel mass and the actual amount in any particular process will depend on the moisture content of the polymer fines and the nature of the silica or silicate. For instance when, as is preferred, the silica is capable of absorbing significant amounts of water it is necessary to include sufficient water to allow for this absorption and for conversion of the particles to a gel mass.
  • the total amount of water typically ranges from 25 to 300% based on the dry weight of polymer particles, with the higher amounts of water (e.g., above 150%) being preferred when water absorbent silica is incorporated. As explained in EP 401044, the extent of cross linking of the polymer particles influences the amount of water that is optimum.
  • the amount of silica or silicate must be sufficient to provide sufficient linkages between adjacent starting polymer particles in each aggregate such that the dry aggregates do not disintegrate to any significant extent when they absorb urine or other liquid. If too much is used, it may act as a release or barrier coating and prevent linkages being formed. If too little is used, it may not permit adequate linkages to be formed.
  • the optimum depends on the material but is typically from 1 to 20% by weight based on the dry weight of polymer particles, with best results generally being obtained with amounts in the range about 3 or 5 to about 15%. However higher amounts, ⁇ •?• up to 25% or even more, may be appropriate in some instances especially when using a coarser or less effective material than fumed or precipitated silica.
  • the polymer particles that are aggregated in the invention can be water soluble polymer particles or, preferably, water swellable but water insoluble polymer particles.
  • the aggregates are preferably water insoluble.
  • the dry particles that are used to form the gel mass preferably have a substantial proportion of fine particles in them. Generally at least 30%, and often at least 50%, may be fines, for instance below 200 ⁇ m and usually below 150 ⁇ m, preferably below lOO ⁇ m. Particles below 50 ⁇ m can cause particularly serious dusting problems and so the invention is of particular value when applied to a fraction having at least 50%, and sometimes at least 90% by weight below 50 ⁇ m.
  • the initial particles can be a fraction sieved from a product, in which event at least 90% of the particles will generally be below 200 and usually below 150 ⁇ m, usually below lOO ⁇ m.
  • the invention is, however, also of value for upgrading the quality of a particulate product that does contain particles of a satisfactory size above 200 ⁇ m but also contains an unacceptably large proportion of fines.
  • the dry particulate product that is formed into the gel mass can be a product which is 0 to 70% by weight, often 0 to 50% by weight, above a chosen particle size and 30 to 100%, often 50 to 100% by weight below that particle size, generally 200 ⁇ m or 150 ⁇ m, more preferably lOO ⁇ m.
  • the dry particles may have been made by reverse phase bead polymerisation, generally followed by sieving to produce a fines fraction for use in the invention, but more usually is made by a process comprising drying and comminution of larger particles.
  • These larger particles may have been made by reverse phase bead polymerisation but, more usually, are made by comminution of gel made by bulk gel polymerisation.
  • the polymer in these particles can be linear but is generally a cross linked polymer. Usually it is a polymer formed from water soluble ethylenically unsaturated material comprising polyethylenically unsaturated cross linking agent with the result that the polymer is cross linked in the backbone of the polymer.
  • the water soluble ethylenically unsaturated material may be a single water soluble ethylenically unsaturated monomer or may be a water soluble blend of ethylenically unsaturated monomers.
  • the ethylenically unsaturated material can be non- ionic, anionic or cationic. If it is ionic, it can be a blend of non-ionic and ionic monomers, the amount of non- ionic monomer often being 0 to 90%, and usually 0 to 70%, by weight of the blend.
  • the preferred ethylenically unsaturated material is generally anionic and may be formed from anionic monomer alone or a blend of anionic and non-ionic monomers.
  • sulphonic monomers e.g., allyl sulphonate or 2- acrylamido-2-methyl propane sulphonate
  • the ethylenically unsaturated material should comprise carboxylic monomer, for instance methacrylic acid, maleic acid, itaconic acid, crotonic acid or, preferably acrylic acid.
  • Suitable non-ionic monomers include vinyl pyrollidone, methacrylamide or, preferably, acrylamide.
  • Suitable cationic monomers include dialkylaminoalkyl (meth) -acrylamides and -acrylates, usually as acid addition or quaternary salts. Examples are dimethylaminoethyl (meth) acrylates and dimethylaminopropyl; (meth) acrylamides.
  • Preferred polymers are formed from 10 to 100%, often 30 to 100%, acrylic acid with the balance being acrylamide. The acrylic acid can be entirely in the form of free acid but, provided this does not interfere with the cross linking reaction, at least 50% and usually at least 75% of the acid groups are present in the form of sodium or other alkali metal or other water soluble salt.
  • the dry particles will often have conventional dryness as a result of drying followed by exposure to the ambient atmosphere, for instance below 15% moisture, and so the process can be applied to the treatment of previously made product.
  • the process of the invention can also be conducted as part of the overall production process starting with polymerisation of the monomer or monomer blend and then the dry particles do not have to be dried fully before they are rewetted and can, instead, still be slightly moist, for instance having a moisture content up to 20 or 25%. The must however be sufficiently dry that they behave as fully dried particles rather than as sticky particles.
  • the aggregates are particulate and generally have a particle size of at least 90% by weight between 100 and lOOO ⁇ m. They generally have a gel capacity of at least 20
  • the absorbent products of the invention can be used as a replacement for conventional absorbent polymeric particles, e.g. in dewatering of mineral slurries or in absorbent articles such as diapers or sanitary napkins.
  • Fines (generally having a size in the range 3 to 50 ⁇ m) of cross linked sodium polyacrylate are dry blended with particulate fumed silica having a particle size below 4 ⁇ m and the mixture is then sprayed with sufficient water to convert the mixture to a substantially homogeneous a d sticky gel.
  • an appropriate amount of water is 35g per 50g fines, but when the amount of silica is 15% an appropriate amount of water is 105g.
  • the resultant gel is extruded, comminuted and dried, for instance in a fluid bed dryer, in a manner that is conventional for drying polymer gel.
  • the resultant product has very high absorbency and high gel strength both when dry and when swollen.
  • the gel strength in one example was 47,000 at a torque of 100,000 and an amplitude of 0.01A, compared to a gel strength of 36,000 when the silica was omitted and the water contained 0.1% ethylene glycol diglycidyl ether, as in EP 401044.
  • Example 3 The process of Example 1 is repeated except that 1% of that ether is incorporated in the water that is used for bonding the polymer-silica mixture.
  • the gel strength increases from 47,000 to 75,000. Further increase is obtainable when the ether is replaced by the silane cross linking agent used in the examples in EP 401044.
  • Example 3

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  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Dispersion Chemistry (AREA)
  • Hematology (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Epidemiology (AREA)
  • Medicinal Chemistry (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Inorganic Chemistry (AREA)
  • Processes Of Treating Macromolecular Substances (AREA)
  • Compositions Of Macromolecular Compounds (AREA)

Abstract

Particules absorbantes, essentiellement composées de zones d'un matériau polymère, réciproquement reliées par des liaisons effectuées par l'intermédiaire d'une quantité agglomérante efficace de silice ou de silicate. On prépare ces particules en formant une masse de gel obtenue en mélangeant des particules d'un matériau polymère avec de l'eau et une quantité agglomérante efficace de silice ou de silicate, et en séchant et broyant la masse de gel.
PCT/GB1993/000357 1992-02-20 1993-02-19 Polymeres absorbants et leur preparation WO1993017066A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB929203594A GB9203594D0 (en) 1992-02-20 1992-02-20 Absorbent polymers and their production
GB9203594.8 1992-02-20
US85750292A 1992-03-25 1992-03-25

Publications (1)

Publication Number Publication Date
WO1993017066A1 true WO1993017066A1 (fr) 1993-09-02

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Family Applications (1)

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PCT/GB1993/000357 WO1993017066A1 (fr) 1992-02-20 1993-02-19 Polymeres absorbants et leur preparation

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WO (1) WO1993017066A1 (fr)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0629411A1 (fr) * 1993-06-18 1994-12-21 SANYO CHEMICAL INDUSTRIES, Ltd. Composition absorbante et couche à jeter contenant cette composition
US5539019A (en) * 1994-08-01 1996-07-23 Leonard Pearlstein High performance absorbent particles and methods of preparation
US5849816A (en) * 1994-08-01 1998-12-15 Leonard Pearlstein Method of making high performance superabsorbent material
US5951970A (en) * 1996-06-19 1999-09-14 Haarmann & Reimer Gmbh Drying composition comprising an odoriferous substance
WO2000031157A1 (fr) * 1998-11-26 2000-06-02 Basf Aktiengesellschaft Hydrogels absorbant des liquides aqueux
EP1123945A2 (fr) * 1992-05-09 2001-08-16 Surfachem Group Limited Conversion de polymères en poudre
WO2006008645A2 (fr) * 2004-07-14 2006-01-26 Sp Healthcare Limited Composition superabsorbante
US7026375B1 (en) 1998-08-26 2006-04-11 Pvaxx Research And Development Limited PVA-containing compositions
US7195777B2 (en) 2000-03-01 2007-03-27 Pvaxx Research & Development Limited Method and apparatus for blowmoding capsules of polyvinylalcohol and blowmolded polyvinylalcohol capsules
KR101673474B1 (ko) * 2015-10-29 2016-11-07 주식회사 불스원 겔 상의 방향제 조성물
KR20180037795A (ko) * 2016-10-05 2018-04-13 주식회사 불스원 겔 상의 방향제 조성물의 제조방법

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0413592A1 (fr) * 1989-08-18 1991-02-20 Ciba Specialty Chemicals Water Treatments Limited Agglomération de matières particulaires
EP0450922A2 (fr) * 1990-04-02 1991-10-09 Nippon Shokubai Kagaku Kogyo Co. Ltd. Procédé de préparation d'un agrégat stable à la fluidité

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0413592A1 (fr) * 1989-08-18 1991-02-20 Ciba Specialty Chemicals Water Treatments Limited Agglomération de matières particulaires
EP0450922A2 (fr) * 1990-04-02 1991-10-09 Nippon Shokubai Kagaku Kogyo Co. Ltd. Procédé de préparation d'un agrégat stable à la fluidité

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
DATABASE WPIL Derwent Publications Ltd., London, GB; AN 89-353795[48] *

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1123945A2 (fr) * 1992-05-09 2001-08-16 Surfachem Group Limited Conversion de polymères en poudre
EP1123945A3 (fr) * 1992-05-09 2001-09-05 Surfachem Group Limited Conversion de polymères en poudre
EP0629411A1 (fr) * 1993-06-18 1994-12-21 SANYO CHEMICAL INDUSTRIES, Ltd. Composition absorbante et couche à jeter contenant cette composition
US5539019A (en) * 1994-08-01 1996-07-23 Leonard Pearlstein High performance absorbent particles and methods of preparation
US5549590A (en) * 1994-08-01 1996-08-27 Leonard Pearlstein High performance absorbent particles and methods of preparation
US5849816A (en) * 1994-08-01 1998-12-15 Leonard Pearlstein Method of making high performance superabsorbent material
US5951970A (en) * 1996-06-19 1999-09-14 Haarmann & Reimer Gmbh Drying composition comprising an odoriferous substance
US7026375B1 (en) 1998-08-26 2006-04-11 Pvaxx Research And Development Limited PVA-containing compositions
US8552071B1 (en) 1998-11-26 2013-10-08 Basf Se Hydrogels absorbing aqueous fluids
WO2000031157A1 (fr) * 1998-11-26 2000-06-02 Basf Aktiengesellschaft Hydrogels absorbant des liquides aqueux
US7195777B2 (en) 2000-03-01 2007-03-27 Pvaxx Research & Development Limited Method and apparatus for blowmoding capsules of polyvinylalcohol and blowmolded polyvinylalcohol capsules
WO2006008645A2 (fr) * 2004-07-14 2006-01-26 Sp Healthcare Limited Composition superabsorbante
WO2006008645A3 (fr) * 2004-07-14 2006-05-18 Sp Healthcare Ltd Composition superabsorbante
KR101673474B1 (ko) * 2015-10-29 2016-11-07 주식회사 불스원 겔 상의 방향제 조성물
KR20180037795A (ko) * 2016-10-05 2018-04-13 주식회사 불스원 겔 상의 방향제 조성물의 제조방법
KR101998552B1 (ko) 2016-10-05 2019-07-10 주식회사 불스원 겔 상의 방향제 조성물의 제조방법

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