CN101115511A

CN101115511A - Water-absorbing material having a coating of elastic film-forming polymers

Info

Publication number: CN101115511A
Application number: CNA2006800041081A
Authority: CN
Inventors: U·里格尔; T·丹尼尔; S·布鲁恩斯; M·埃利奥特; R·D·福萨姆; M·施密特; A·迈尔; J·S·迈德森
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2005-02-04
Filing date: 2006-02-03
Publication date: 2008-01-30

Abstract

The present invention relates to a water-absorbing material obtainable by a process comprising the steps of a) spray-coating water-absorbing polymeric particles with an elastic film-forming polymer in a fluidized bed reactor in the range from 00C to 500C and b) heat-treating the coated particles at a temperature above 500C. and also to a process for its production.

Description

Water absorbing material with elasticity film forming polymer coating

The present invention relates to a kind of water absorbent polymer with elasticity film forming polymer coating with and production method.

The important component part of disposable absorbent article such as diaper is an absorbent core structures, and this absorbent core structures comprises water absorbent polymer, is generally the water absorbent polymer that forms hydrogel, and it is also referred to as the absorbability gel rubber material, AGM, perhaps super absorbent polymer or SAP.This polymeric material guarantees that a large amount of body fluid can be absorbed in its use by goods and pin as urine, and this provides low rewetting and advantages of good skin drying.

Useful especially water absorbent polymer or SAP are often by at first at more a spot of two-or polyfunctional monomer such as N, N '-methylene diacrylamine, trimethylolpropane triacrylate, ethylene glycol bisthioglycolate (methyl) acrylate or triallylamine exist polymerizable unsaturated monocarboxylic acid or derivatives thereof such as acrylic acid down, or acrylic acid alkali metal (as sodium and/or potassium) salt or ammonium salt, alkyl acrylate etc. and preparing.Two-or the polyfunctional monomer material be used for the micro-crosslinked polymer chain, make thus they water insoluble but still the suction.This crosslinked slightly absorbable polymer contains a plurality of carboxylic acidulants groups that link to each other with polymer backbone.It has been generally acknowledged that neutral carboxylic acidulants group produces osmotic drive power by crosslinked polymer network to body fluid absorption.In addition, handle polymer beads usually to form surface-crosslinked layer at outer surface, to improve their especially performances in baby diaper is used.

The polymer that can be used as the water absorption (formation hydrogel) of absorbent in absorption piece and goods such as disposable diaper need have sufficiently high absorbability and sufficiently high gel strength.Absorbability needs enough height and uses a large amount of aqueous body fluids that run in the absorbent article process so that absorbable polymer can be absorbed in.Together with other performance of gel, gel strength relates to the ability of swollen polymer particles resistance to deformation under the stress that applies.Gel strength needs enough height in absorption piece or goods, so that granule can not be out of shape and fill the capillary gap space to the unacceptable degree that causes so-called gel blocking.This gel blocking has suppressed the speed of absorption of fluids or fluid distribution, promptly in case gel blocking takes place, it can significantly hinder dried area or the area distribution of fluid to absorbent article, and before absorbent polymer particles is fully saturated or at fluid, can spread or before capillary enters the remainder of absorbent article by " gel blocking " granule, seepage from the absorbent article can take place.Therefore importantly water absorbent polymer (in mixing absorbing structure or goods time) keeps high wet porosity and height resistance to deformation, therefore the fluid by swell gel bed is produced high permeability.

Absorbable polymer with higher permeability can prepare by crosslinked or surface-crosslinked level in increasing, crosslinked or surface-crosslinked level has improved the opposing of swell gel to the distortion that caused as the pressure that is caused by wearer by external pressure in increasing, but this has also reduced the absorbability of gel usually, and this is undesirable.Conventional by way of remarkable shortcoming be to sacrifice absorbability and obtain permeability.In hygienic articles, lower absorbability must be compensated by higher absorbable polymer consumption, and this has for example caused the difficulty of the core integrity of diaper in the wearing process.Therefore, need specific technological challenge and expensive technique for fixing overcoming this problem, and also have the higher cost that produces because need higher absorbable polymer consumption level.

Because in the balance of routine between middle absorbability and permeability, the therefore extremely difficult absorbable polymer that shows by the described improvement performance relevant of following empirical equation of producing with absorbability and permeability:

(1)Log(CS-SFC’/150)≤3.36-0.133×CS-CRC

Even more difficult production shows the absorbable polymer by the described improvement performance relevant with absorbability and permeability of following empirical equation:

(2)Log(CS-SFC’/150)≤2.5-0.095×CS-CRC

Therefore wish very much to produce to satisfy and establish an equation (3) or (4) down or the absorbable polymer of preferred (3) and (4):

(3)Log(CS-SFC’/150)＞3.36-0.133×CS-CRC

(4)Log(CS-SFC’/150)＞2.5-0.095×CS-CRC

In above-mentioned all equations, CS-SFC '=CS-SFC * 10 ⁷And 150 dimension is [cm ³S/g].

Usually surface-crosslinked absorbent polymer particles is subjected to surface-crosslinked shell restriction and can not fully absorbs and swelling, and/or surface-crosslinked shell undercapacity is to bear swollen stress or the relevant stress of the behavior under load.

Consequently when the remarkable swelling of polymer, the coating or the shell (comprising surface-crosslinked ' coating ') that are used for the water absorbent polymer of this area break, or be in swollen state during following a period of time ' coating ' break.Therefore coating known in the art and/or surface-crosslinked absorbable polymer or often significantly distortion in use of super-absorbent material cause the gel bed lower in hygrometric state mesopore rate and permeability.

The purpose of this invention is to provide a kind of more favourable surface modification, wherein in the swelling process of the hygienic articles that uses this absorbable polymer preparation, and preferred integrity that should the surface in the operating period of described hygienic articles is kept.

EP-A-0 703 265 has instructed with film forming polymer such as acrylic acid/methacrylic acid dispersion treating water gel to produce wear-resistant absorbent.Described inorganic agent comprises polyurethane.Yet the absorbing particles that wherein obtains especially has not satisfied absorption value for CS-CRC and CS-SFC.And the list of references of being quoted does not have instruction how to produce the uniform coating that in swelling and use their mechanical performance keeps enough degree.

Therefore, the purpose of this invention is to provide the water-absorbing polymeric particles that a kind ofly has the centrifugal reserve capability of high core shell (CS-CRC), has absorbance (CS-AUL) and high core shell saline flow conductivity (CS-SFC) under the load of high core shell, this water absorbent polymer especially must have high core shell saline flow conductivity (CS-SFC).

We find that this purpose is by being realized by the water absorbing material that the method that comprises the steps obtains:

A) under 0-50 ℃ temperature with elasticity film forming polymer spray application water-absorbing polymeric particles and

B) granule that heat treatment applies under the temperature more than 50 ℃.

Preferably include the method for following steps:

A) under 0-50 ℃ in fluidized-bed reactor with elasticity film forming polymer spray application water-absorbing polymeric particles and

B) granule that heat treatment applies under the temperature more than 50 ℃.

The present invention further provides a kind of method of producing water absorbing material, it comprises the steps:

A) in fluidized-bed reactor, preferably with continuity method, at 0-50 ℃, preferably be lower than under 45 ℃ the temperature with elasticity film forming polymer spray application water-absorbing polymeric particles and

B) granule that heat treatment applies under the temperature more than 50 ℃.It should be understood that the feature at theme of the present invention mentioned above and that will more specifically describe hereinafter not only can also not break away from being used in combination of the scope of the invention with other with described specific being used in combination.

Water absorbing material herein is for passing through to absorb the water swelling in water; Can form gel thus.It also can absorb other liquid and swelling.Therefore when being used for this paper, ' suction ' is meant absorbed water and swelling in water usually, but usually also in other liquid or solution, preferably based on the liquid of water as 0.9% saline and urine in absorption water and swelling.

Within the scope of the invention, noble gas is for being gaseous form and not having the material of Oxidation and the mixture of these gases to the component of reactant mixture or to polymer under these conditions under each reaction condition.Useful noble gas for example comprises nitrogen, carbon dioxide or argon, preferred nitrogen.

For the purpose of the present invention, usefully in principle those skilled in the art by known all the particle-shape water-absorbing polymer of superabsorbents document, for example as Modern Superabsorbent PolymerTechnology, F.L.Buchholz, A.T.Graham is described in the Wiley 1998.Water-absorbing polymeric particles is preferably the spheroidal particle that is obtained by inverse suspension polymerization usually; Their optional can being focused at least to a certain degree to form bigger irregular particle.But the most preferably commercially available irregularly shaped particles that can obtain by the prior art production method, this special by way of example and more hereinafter description.

The water-absorbing polymeric particles that applies according to the present invention is preferably can be by the polymer beads that the polymerizable monomer solution that comprises following component is obtained:

I) at least a ethylenic unsaturated acid functional monomer,

Ii) at least a cross-linking agent,

Iii) suitable words one or more can with i) olefinic of copolymerization and/or pi-allyl belong to unsaturated monomer and

Can partially grafted at least monomer i on the iv) suitable words one or more its), ii) and suitable iii) water-soluble polymer,

Wherein gained base polymer drying, classification and suitable words were used v) before drying subsequently and are handled:

V) at least a back cross-linking agent, and heat back crosslinked (promptly surface-crosslinked).

Useful monomer i) for example comprises ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid and itaconic acid, or derivatives thereof such as acrylamide, Methacrylamide, acrylate and methacrylate.Acrylic acid and methacrylic acid are particularly preferred monomer.Acrylic acid most preferably.

Water absorbent polymer used according to the invention is generally crosslinked, promptly is aggregated in to have two or more free redical copolymerization and go into the chemical compound of the polymerizable groups of polymer network and carry out under existing.Useful cross-linking agent ii) for example comprises the 530 438 described ethylene glycol dimethacrylates as EP-A, diethylene glycol diacrylate, allyl methacrylate, trimethylolpropane triacrylate, triallylamine, tetraene propoxyl group ethane, as EP-A 547 847, EP-A 559 476, EP-A 632 068, WO 93/21237, WO 03/104299, WO 03/104300, diacrylate and triacrylate described in WO 03/104301 and the DE-A 10,331 450, the mixing acrylate that also comprises other ethylenically unsaturated group except that acrylate group described in DE-A 103 31 456 and DE-A103 55 401 is perhaps for example as DE-A 195 43 368, DE-A 196 46 484, cross-linking agent mixture described in WO 90/15830 and the WO 02/32962.

Useful cross-linking agent ii) especially comprises N, N '-methylene-bisacrylamide and N, N '-di-2-ethylhexylphosphine oxide Methacrylamide, the unsaturated monocarboxylic acid of polyhydric alcohol or the ester of polybasic carboxylic acid, for example diacrylate or triacrylate such as butanediol diacrylate, butanediol dimethylacrylate, glycol diacrylate, ethylene glycol dimethacrylate and trimethylolpropane triacrylate, and allyl compound is as (methyl) allyl acrylate, triallyl cyanurate, diallyl maleate, the polyene propyl diester, tetraene propoxyl group ethane, triallylamine, the tetraallyl ethylenediamine, the allyl ester of phosphoric acid and the vinyl phosphonic acid derivative described in EP-A-0 343 427 for example.Useful cross-linking agent ii) also comprises pentaerythritol diallyl ether, pentaerythritol triallyl ether, pentae-rythritol tetraallyl ether, Polyethylene Glycol diallyl ether, ethylene glycol bisthioglycolate allyl ether, glycerol diallyl ether, glycerol triallyl ether, based on the polyallyl ether and the ethoxylation variant thereof of Sorbitol.The inventive method is preferably utilized two (methyl) acrylate of Polyethylene Glycol, and wherein the molecular weight of used Polyethylene Glycol is the 300-1000g/ mole.

Yet, particularly advantageous cross-linking agent is ii) for being total to the heavily glycerol of ethoxylation of 3-15, be total to the 3-15 heavily diacrylate and the triacrylate of the trimethylolpropane of ethoxylation, especially the totally 3 heavily glycerol or totally 3 heavy trimethylolpropanes of ethoxylation of ethoxylation, 3 heavy propenoxylated glycerol, 3 heavy propenoxylated trimethylolpropanes, and totally 3 reblending ethoxylations or propenoxylated glycerol, totally 3 reblending ethoxylations or propenoxylated trimethylolpropane, totally 15 heavy glycerol of ethoxylation, totally 15 heavy trimethylolpropanes of ethoxylation, the totally 40 heavily glycerol and the totally 40 heavily diacrylate and triacrylates of the trimethylolpropane of ethoxylation of ethoxylation.Wherein n heavily ethoxylation be meant n mole ethylene oxide and 1 mole of each polyol reaction, wherein n is the integer greater than 0.

Very particularly preferably as cross-linking agent ii) be the multiple ethoxylation and/or the propenoxylated glycerol of diacrylate esterification, dimethylacrylateization, triacrylateization or trimethyl acrylic esterization, for example as described in the German patent application DE 103 19 462.2 formerly.Particularly advantageous is two of the heavy ethoxylated glycerol of 3-10-and/or triacrylate.Heavy two-or the triacrylate of ethoxylation and/or propoxylated glycerol of 1-5 very particularly preferably.The heavy triacrylate of ethoxylation and/or propoxylated glycerol of 3-5 most preferably.The remarkable part of these cross-linking agent is their residual level in water absorbent polymer low especially (usually below 10ppm), and compare with the surface tension (being not less than 0.068N/m usually) of water under the uniform temp, have almost constant surface tension with the aqueous extract of the water absorbent polymer of its generation.

Can with monomer i) the ethylenically unsaturated monomer example iii) of copolymerization is the amino peopentyl ester of acrylamide, Methacrylamide, crotonamide, dimethylaminoethyl methacrylate, acrylic acid dimethylamino ethyl ester, acrylic acid dimethylamino propyl ester, acrylic acid diethylamino propyl ester, acrylic acid dimethylamino butyl ester, dimethylaminoethyl methacrylate, diethyl aminoethyl methacrylate, acrylic acid dimethylamino peopentyl ester and dimethylaminoethyl acrylate methyl base.

Useful water-soluble polymer iv) comprises polyvinyl alcohol, polyvinylpyrrolidone, starch, starch derivatives, Polyethylene Glycol, polyacrylic acid, polyvinylamine or polyallylamine, the polyvinyl formamide of partial hydrolysis or PVAA, the pure and mild starch of preferably polyethylene.

Preferred its base polymer is little crosslinked water-absorbing polymeric particles.Little degree of cross linking is with high crc value and the reflection of extractable content.

The consumption of cross-linking agent (depend on its molecular weight and definite form) is preferred to make that the base polymer CRC when its granularity is 150-850 μ m that is produced is that the extractable content of 20-60g/g and 16 hours is no more than 25 weight %.Preferred CRC is 30-45g/g, more preferably 33-40g/g.

16 hours extractable content of preferred especially base polymer are no more than 20 weight %, preferably are no more than 15 weight %, even more preferably no more than 10 weight %, are most preferably not exceeding 7 weight % and its crc value in above-mentioned preferable range.

The preparation of suitable basic polymer and other useful hydrophilic ethylenically unsaturated monomer i) be described among DE-A 199 41 423, EP-A 686 650, WO 01/45758 and the WO 03/104300.

The reaction preference perhaps for example carries out in belt reactor described in EP-A-0 955 086 as carrying out in kneader described in WO01/38402.

Can also use the inverse suspension polymerization method of any routine.Suitable words can reduce the content of cross-linking agent greatly or omit fully in this inverse suspension polymerization method because in this method certain condition well known by persons skilled in the art issue be conigenous crosslinked.

Can also use any required spray polymerisation method to prepare base polymer.

The preferred 30-100 mole of the acidic-group of gained base polymer %, more preferably 65-90 mole %, most preferably 72-85 mole % is neutralized, can use conventional nertralizer for neutralization, for example ammonia or amine such as ethanolamine, diethanolamine, triethanolamine or dimethylaminoethanol amine, preferred alkali metal hydroxide, alkali metal oxide, alkali carbonate or alkali metal hydrogencarbonate and composition thereof, this moment, alkali metal was preferably sodium and potassium especially, also most preferably sodium hydroxide, sodium carbonate or sodium bicarbonate and composition thereof.Neutralization usually by with nertralizer with aqueous solution or aqueous dispersion or preferably sneak into and realize with fusion or with solid material.

Neutralization can be carried out in the base polymer section after polymerization.But also can before polymerization, be neutralized to many 40 moles of % by add the part nertralizer to monomer solution, preferred 10-30 mole %, the more preferably acidic-group of 15-25 mole %, and only after polymerization, set final required degree of neutralization in the base polymer section.Can monomer solution be neutralized to predetermined preneutralization degree by sneaking into nertralizer, post neutralization perhaps directly transfers to end value by sneaked into nertralizer before polymerization with monomer solution to end value after polyreaction or in polymerization process subsequently.The base polymer mechanical activation comminution for example can be pulverized by meat grinder, can or be poured into nertralizer spraying, sprinkle under this situation, carefully sneak into subsequently.For this reason, the gained gel piece can be shredded and homogenize repeatedly.

Then with neutral base polymer belt dryer, fluidized bed dryer, tower drier or rotary drum dryer drying, preferably be lower than 13 weight % until residual moisture content, especially be lower than 8 weight %, most preferably be lower than 4 weight %, wherein water content is measured according to the method for testing No.430.2-02 " moisture " that is recommended by EDANA (EuropeanDisposables and Nonwovens Association).Then exsiccant base polymer is ground and screening, available milling apparatus generally includes roller mill, needle mill, hammer mill, jet mill or swing grinding machine.

Subsequently can stand-by water absorbent polymer back in a deformation program of the present invention is crosslinked.Useful back cross-linking agent v) comprises and comprises the chemical compound that two or more can form the group of covalent bond with the carboxylate group of polymer.Useful chemical compound for example comprises as EP-A 083 022, EP-A 543303 and EP-A 937 736 described polyglycidyl compounds, polyaziridine, polyamines, daiamid, two-or multi-shrinking glyceryl compound, as DE-C 33 14 019 described polyhydric alcohol.Useful back cross-linking agent v) further comprises the cyclic carbonate of DE-A 40 20 780; the 2- oxazolidone of DE-A 198 07502 and derivant thereof such as N-(2-hydroxyethyl)-2- oxazolidone; two (the 2- oxazolidones) of DE-A 198 07992 and poly-(2- oxazolidone); the 2-oxo tetrahydrochysene-1 of DE-A 198 54 573; 3- piperazine and derivant thereof; the N-acyl group of DE-A 198 54 574-2- oxazolidone; the ring urea of DE-A 10,204 937; German patent application 103 34 584.1 bicyclic amide acetals; the morpholine-2 of the oxetanes of EP-A 1 199 327 and ring urea and WO 03/031482,3-diketone and derivant thereof.

The back is crosslinked is undertaken by the back cross-linking agent solution is sprayed on the base polymer or on the base polymer composition granule of doing usually.Heated drying after spraying, back cross-linking reaction not only can be carried out before drying, also can carry out in dry run.

Preferred back cross-linking agent v) is the amide acetals or the carbamate of general formula I:

Wherein

R ¹Be C ₁-C ₁₂Alkyl, C ₂-C ₁₂Hydroxy alkyl, C ₂-C ₁₂Alkenyl or C ₆-C ₁₂Aryl,

R ²Be X or OR ⁶,

R ³Be hydrogen, C ₁-C ₁₂Alkyl, C ₂-C ₁₂Hydroxy alkyl, C ₂-C ₁₂Alkenyl or C ₆-C ₁₂Aryl or X,

R ⁴Be C ₁-C ₁₂Alkyl, C ₂-C ₁₂Hydroxy alkyl, C ₂-C ₁₂Alkenyl or C ₆-C ₁₂Aryl,

R ⁵Be hydrogen, C ₁-C ₁₂Alkyl, C ₂-C ₁₂Hydroxy alkyl, C ₂-C ₁₂Alkenyl, C ₁-C ₁₂Acyl group or C ₆-C ₁₂Aryl,

R ⁶Be C ₁-C ₁₂Alkyl, C ₂-C ₁₂Hydroxy alkyl, C ₂-C ₁₂Alkenyl, C ₁-C ₁₂Acyl group or C ₆-C ₁₂Aryl and

X is R ²And R ³Common ketonic oxygen,

R wherein ¹And R ⁴And/or R ⁵And R ⁶Can be the C of bridging ₂-C ₆Alkane 2 basis, wherein above-mentioned radicals R ¹-R ⁶Still can have 1 to 2 free valency altogether, and can be connected with at least a suitable base structure by these free valencys, 2- (oxazolidinon-5-yl-methyl)-2-thiophene-carboxamides such as 2- oxazolidone and N-ethoxy-2- oxazolidone for example, N-hydroxypropyl-2- oxazolidone, N-methyl-2- oxazolidone, N-acyl group-2- oxazolidone such as N-acetyl group-2- oxazolidone, 2-oxo tetrahydrochysene-1,3- piperazine, bicyclic amide acetal such as 5-methyl isophthalic acid-azepine-4,6-two oxa-dicyclo [3.3.0] octanes, 1-azepine-4,6-two oxa-dicyclo [3.3.0] octanes and 5-isopropyl-1-azepine-4,6-two oxa-dicyclo [3.3.0] octanes, two-2- oxazolidone and poly--2- oxazolidone;

It perhaps is polyhydric alcohol, this moment, the molecular weight of polyhydric alcohol preferably was lower than 100g/mol, preferably be lower than 90g/mol, more preferably less than 80g/mol, most preferably be lower than the every hydroxyl of 70g/mol, and polyhydric alcohol not contiguous, the paired second month in a season or tert-hydroxyl, and polyhydric alcohol or be the glycol of general formula I Ia, or be the polyhydric alcohol of general formula I Ib:

HO-R ⁶-OH (IIa)

R wherein ⁶Or be formula-(CH ₂) _m-not sub-branched alkyl, wherein m is the integer of 3-20, preferred 3-12, and two hydroxyls all can be in the end, or be not branching, branching or cyclic alkylidene,

R wherein ⁷, R ⁸, R ⁹And R ¹⁰Be hydrogen, hydroxyl, methylol, '-hydroxyethoxy ylmethyl, 1-hydroxyl third-2-base oxygen ylmethyl, 2-hydroxyl propoxyl group methyl, methyl, ethyl, n-pro-pyl, isopropyl, normal-butyl, n-pentyl, n-hexyl, 1 independently, 2-dihydroxy ethyl, 2-hydroxyethyl, 3-hydroxypropyl or 4-hydroxybutyl and always co-exist in 2,3 or 4, preferred 2 or 3 hydroxyls, and R ⁷, R ⁸, R ⁹And R ¹⁰In be no more than one for hydroxyl, example is 1, ammediol, 1, the 5-pentanediol, 1,6-hexanediol and 1, the 7-heptandiol, 1, the 3-butanediol, 1, the 8-ethohexadiol, 1,9-nonanediol and 1, the 10-decanediol, butane-1,2, the 3-triol, butane-1,2, the 4-triol, glycerol, trimethylolpropane, trimethylolethane, tetramethylolmethane, per molecule has the glycerol of 1-3 ethylene oxide unit separately, per molecule has the trimethylolethane or the trimethylolpropane of 1-3 ethylene oxide unit separately, propoxylated glycerol, per molecule has 1-3 propylene oxide unit trimethylolethane or trimethylolpropane separately, 2 heavily ethoxylation or propenoxylated neopentyl glycols or be the cyclic carbonate of general formula III:

R wherein ¹¹, R ¹², R ¹³, R ¹⁴, R ¹⁵And R ¹⁶Be that hydrogen, methyl, ethyl, n-pro-pyl, isopropyl, normal-butyl, sec-butyl or isobutyl group and n are 0 or 1 independently, example is ethylene carbonate and propylene carbonate,

Or be two  azoles quinolines of general formula I V:

R wherein ¹⁷, R ¹⁸, R ¹⁹, R ²⁰, R ²¹, R ²², R ²³And R ²⁴Be hydrogen, methyl, ethyl, n-pro-pyl, isopropyl, normal-butyl, sec-butyl or isobutyl group independently, R ²⁵Be singly-bound, linearity, branching or ring-type C ₁-C ₁₂Alkylidene or by 1-10 ethylene oxide and/or propylene oxide unit constitutes and poly-alkoxyl two bases that comprised of polyglycols dicarboxylic acids for example.Formula IV examples for compounds is 2,2 '-two (2- azoles quinolines).

At least a back cross-linking agent v) is generally about 1.50 weight % or lower with the consumption that aqueous solution uses, preferably be no more than 0.50 weight %, more preferably no more than 0.30 weight %, most preferably in the scope of 0.001-0.15 weight %, wherein all percents are based on base polymer.Can use in the above-mentioned selection a kind of back cross-linking agent v) or use any desired mixts of various backs cross-linking agent.

Except that described at least a back cross-linking agent v), the crosslinked aqueous solution in back also can comprise cosolvent usually.Highly useful cosolvent is C on technology ₁-C ₆Alcohol is as methanol, ethanol, normal propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, the tert-butyl alcohol or 2-methyl isophthalic acid-propanol, C ₂-C ₅Glycol such as ethylene glycol, 1,2-propylene glycol, 1, ammediol or 1,4-butanediol, ketone such as acetone, or carboxylate such as ethyl acetate.

Preferred embodiment is not used any cosolvent.Therefore at least a back cross-linking agent v) only uses with aqueous solution and adds or do not add the disaggregation auxiliary agent.The disaggregation auxiliary agent is known to those skilled in the art and for example is described in DE-A-10 239 074 and formerly among the PCT application PCT/EP/2005/011073, is introduced into as a reference especially herein.Preferred disaggregation auxiliary agent is ethoxylation and the alkoxy derivative and the anhydrosorbitol monoesters of surfactant such as 2-propyl enanthol.Preferred especially disaggregation auxiliary agent is polyoxyethylene 20 anhydrous sorbitol ether monolaurates and PEG 400 monostearate ester.

At least a back cross-linking agent v) concentration in the crosslinker solution of back for example is 1-50 weight % based on the back cross-linking agent solution, preferred 1.5-20 weight %, more preferably 2-5 weight %.

In another embodiment, be dissolved at least a organic solvent back cross-linking agent and the spraying dispersion; At this moment, the water content of solution is lower than 10 weight %, does not preferably make water in the crosslinker solution of back.

Yet, be understood that the back cross-linking agent that has quite surface-crosslinked result for final polymer performance certainly is used for the present invention, in addition when contain this after the water content of solution of cross-linking agent and optional cosolvent in the scope of＞0 to＜100 weight %.

The total amount of back crosslinker solution is generally 0.3-15 weight % based on base polymer, preferred 2-6 weight %.The crosslinked operation in back is common practise to those skilled in the art and for example is described in DE-A-12 239 074 and formerly among patent application PCT/EP/2005011073.

Can be used for the crosslinked nozzle in back and be not subjected to any restriction.Suitable nozzle and atomization system for example are described in the following list of references: Zerst  uben von Fl ü ssigkeiten, Expert-Verlag, the 660th volume, Reihe Kontakt﹠amp; Studium, Thomas Richter (2004) and Zerst  ubungstechnik, Springer-Verlag, VDI-Reihe, G ü nter Wozniak (2002).Can use single the dispersion and the polydispersion spraying system.Suitable polydisperse system comprises pure drive nozzle (forming jet or thin layer), rotary atomizer, extra quality nebulizer, ultrasound atomizer and impulse nozzle.For double nozzle, liquid and gas not only can also can externally mix in inside.Not crucial by the spray shapes that nozzle produces, and can suppose for example circular jet of any required form, flat jet, the circular jet of Radix Rumicis or annulus.When using extra quality nebulizer, it is favourable using noble gas.This class nozzle can pressurize to infeed and wait to spray dispersive liquid.The atomizing of dispersing liquid of waiting to spray this moment can be undertaken by liquid is reduced pressure after liquid reaches a certain minimum-rate.Also useful nozzle is pure nozzle, for example slot nozzle or eddy current or rotating room (solid cone spray nozzle) (for example can be by D ü sen-Schlick GmbH of Germany, or obtained by the Spraying SystemsDeutschland GmbH of Germany).This class nozzle also is described among EP-A-0 534 228 and the EP-A-1191 051.

The spraying after, the heated drying water-absorbing polymeric particles, and the back cross-linking reaction can before the drying, during or carry out afterwards.

Spraying back cross-linking agent solution preferably carries out in having the blender of mobile hybrid component, for example carries out in screw mixer, blade-type mixer, disk mixer, plow mixers and arm mixer.Preferred especially vertical blender, very particularly preferably plow mixers and arm mixer.Useful mixer instance is as comprising L  dige ^Blender, Bepex ^Blender, Nauta ^Blender, Processall ^Blender and Schugi ^Blender.

Preferably,, most preferably pan dryer is used as the equipment that wherein carries out heated drying more preferably with pedal-type dryer with the contact drying device.Suitable exsiccator for example comprises Bepex ^Exsiccator and Nara ^Exsiccator.Also can use fluidized bed dryer such as Carman ^Exsiccator.

Dry for example can or introduce warm inert gas and in blender self, carry out by heating jacket.Can use concurrent drying device such as tower disc type exsiccator, Rotary pipe type baking oven or heatable screw rod similarly.But for example also can use azeotropic distillation as drying means.

Particularly preferably in super mixer such as Schugi-Flexomix ^Or Turbolizer ^In the type blender back cross-linking agent solution is applied to base polymer, makes base polymer then at reaction equation exsiccator such as Nara-Paddle-Dryer ^Type exsiccator or pan dryer (are Torus-Disc Dryer ^, Hosokawa) crosslinked after the middle heat.Temperature from the base polymer of formerly operating still can be 10-120 ℃, and the temperature of back crosslinker solution can be 0-150 ℃.More particularly can heat the back crosslinker solution to reduce viscosity.Preferred crosslinked and baking temperature afterwards is 30-220 ℃, especially 120-210 ℃, and most preferably 145-190 ℃.Be more preferably less than 70 minutes in the preferred time of staying in reaction equation blender or exsiccator under this temperature less than 100 minutes, most preferably less than 40 minutes.

Especially preferably fluidized bed dryer is used for the back cross-linking reaction, time of staying this moment preferably is lower than 30 minutes, more preferably less than 20 minutes, most preferably is lower than 10 minutes.

Crosslinked exsiccator in back or fluidized bed dryer available air or dry air operation are effectively to remove steam from polymer.

Preferably in dry and back cross-linking reaction process with the crosslinked exsiccator of inert gas purge to remove steam and replace oxygen voltinism gas such as aerial oxygen.Noble gas usually as above has identical relative humidity and limits air is described.Also can use the mixture of air and noble gas.For promoting drying means, and the ideally fully heating adiabatic well with exsiccator with the assembly that is connected.Crosslinked exsiccator inside, back preferably is in atmospheric pressure or slightly reduced pressure or overvoltage.

For producing very white polymer, the gas compartment in the exsiccator keeps oxygen-free voltinism gas as far as possible; Under any circumstance, the oxygen volume content in the gas compartment is no more than 14 volume %.

The particle size distribution of water-absorbing polymeric particles can be 45-4000 μ m.The particle size distribution that is used for health field is preferably 45-1000 μ m, preferred 45-850 μ m, especially 100-850 μ m.The preferred water-laden polymer particles that applies has narrow particle size distribution, especially 100-850 μ m, or even 100-600 μ m.

Narrow particle size distribution is the granule that is not less than 80 weight %, preferably is not less than the granule of 90 weight %, and the particulate granularity that most preferably is not less than 95 weight % is in selected scope; Described mark can be measured by the habitual screen method that uses EDANA No.420.2-02 " particle size distribution ".Also can select to use optical means, condition is that these methods are proofreaied and correct the screen method of accepted EDANA.

The span of preferred narrow particle size distribution is no more than 700 μ m, more preferably no more than 600 μ m, most preferably less than 400 μ m.Span is meant poor between the scalping that limit to distribute and the dusting cover herein.Scalping is not coarser than 850 μ m and dusting cover is not narrower than 45 μ m.450 μ m), 200-700 μ m (span: 500 μ m), 150-500 μ m (span: 350 μ m), 150-300 μ m (span: 150 μ m), 300-700 μ m (span: 400 μ m), 400-800 μ m (span: 400 μ m), 100-800 μ m (span: fraction 700 μ m) for the purpose of the present invention, preferred particle size range for example is a 150-600 μ m (span:.

The same monodispersed water-absorbing polymeric particles that preferably obtains by inverse suspension polymerization method.The mixture of monodisperse particles that can select to have different-diameter similarly is as water-absorbing polymeric particles, for example has the monodisperse particles of minor diameter and has the mixture of large diameter monodisperse particles.Can use monodispersed mixture similarly with polydisperse water-absorbing polymeric particles.

According to the present invention, apply these and have narrow particle size distribution, the water-absorbing polymeric particles of preferred maximum particle size≤600 μ m provides quick swelling and so particularly preferred water absorbing material.

The shape of absorbent particle can be spherical and erose granule.

The coating polymer that the present invention uses is film forming and has elastic performance.Polymer with film forming and elastic performance all is fit to usually, as copolyesters, copolyamide, polysiloxanes, styrene-isoprene block copolymer, styrene-butadiene block copolymer, optimization polyurethane.

Film forming be meant each polymer can its dissolve or dispersive solvent evaporation after easily cambium layer or coating.Polymer for example can be thermoplasticity and/or crosslinked.Elasticity is meant that material can present the distortion that tension force causes, and should distortion partly or fully reply after tension force is removed.

In one embodiment, the tensile stress at break of polymer under hygrometric state is at least 1MPa, or even 3MPa at least, more preferably 5MPa at least, or even 8MPa at least.Most preferably the tensile stress at break of material is at least 10MPa, preferably 40MPa at least.This can be via determination of test method hereinafter described.

In one embodiment, the particularly preferred polymer of this paper is by the wet secant modulus of elasticity (SM of following determination of test method under 400% percentage elongation _{Wet 400%}) be at least 0.25MPa, preferred 0.50MPa at least, more preferably at least about 0.75MPa or even 2.0MPa at least, most preferably at least about the material of 3.0MPa.

In one embodiment, [wet secant modulus of elasticity (the SM under 400% percentage elongation of the preferred polymers of this paper _{Wet 400%})] and [dry secant modulus of elasticity (SM under 400% percentage elongation _{Dry 400%})] ratio be 10 or lower, preferred 1.4 or lower, more preferably 1.2 or lower, or even more preferably 1.0 or lower, and preferably this ratio can be at least 0.1, preferably at least 0.6 or even at least 0.7.

In one embodiment, film forming polymer is for being about 5 to 200N/m with shell tension force (being defined as (thickness of the shell of Xiang Denging in theory) * (the average wet secant modulus of elasticity under 400% percentage elongation)), or preferred 10-170N/m, or more preferably 20-130N/m, even more preferably the coating form of 40-110N/m exists.

In one embodiment of the invention, the water-absorbing polymeric particles of this paper surface-crosslinked (apply before the shell as herein described or apply this shell time), may in addition more preferably the shell tension force of this water absorbing material be 15-60N/m, or even more preferably 20-60N/m, or preferred 40-60N/m.

Wherein in not surface-crosslinked another embodiment of water-absorbing polymeric particles, even more preferably the shell tension force of water absorbing material is about 60-110N/m.

In one embodiment, film forming polymer is to exist at the lip-deep coating form of water absorbing material, its shell impact parameter (being defined as (the average wet secant modulus of elasticity under 400% percentage elongation) * (shell polymeric is with respect to the relative weight of coated polymer gross weight)) is about 0.03-0.6MPa, preferred 0.07-0.45MPa, more preferably from about 0.1 to 0.35MPa." shell polymeric is with respect to the relative weight of coated polymer gross weight " is generally the mark of 0.0-1.0.

The gained water absorbing material shows with the assimilate ability of CS-CRC experimental measurement with infiltrative uncommon effective combination of CS-SFC experimental measurement as herein described.

A preferred embodiment, absorbent material show to surpass 1.0, and preferably at least about 2.0, more preferably at least about 3.0, even more preferably at least about 6.0, most preferably at least about particularly advantageous absorbance-distribution-index (ADI) of 10.0, wherein ADI is following defines:

ADI＝(CS-SFC′/150)/10 ^{2.5-0.095×CCRC}

In this equation, CS-SFC '=CS-SFC * 10 ⁷And 150 dimension is [cm ³S/g].CCRC is the centrifugal reserve capability of cylinder after the swelling described in the following Test Methods section 4 hours.

Usually the ADI of water absorbing material is no more than approximately 200, is no more than 50 usually.

In the most preferred embodiment, water absorbing material produce to surpass 1, and preferably at least 6, or even more preferably at least 10, and preferred at the most 200 or more preferably 50 the profile exponent of absorbance as herein defined (ADI) at the most.

In one embodiment, be preferably membrane polymer especially for polyurethane, it is opposite with water-absorbing polymeric particles, and (if words) only omits microswelling when contacting with aqueous fluid.The water-soluble bloated ability that this means film forming polymer in fact is preferably less than 1g/g, or even less than 0.5g/g, or even less than 0.2g/g, or even less than 0.1g/g, described water-soluble bloated ability can be measured by method hereinafter described.

In another embodiment, be preferably membrane polymer and especially be polyurethane, it is opposite with water-absorbing polymeric particles, only appropriate swelling when contacting with aqueous fluid.The water-soluble bloated ability that this means film forming polymer in fact is 1g/g at least preferably, or greater than 2g/g, or even greater than 3g/g, or preferred 4-10g/g, but less than 30g/g, preferably less than 20g/g, most preferably less than 12g/g, described water-soluble bloated ability can be measured by method hereinafter described.

Film forming polymer makes that usually the gained coating on the water-swellable polymer of this paper is water insoluble, preferably is not water dispersible.

In one embodiment, polymer makes that preferably the gained coating on the water-swellable polymer of this paper is a water permeability, but water insoluble, preferably is not water dispersible.Preferred polymers, especially polyurethane (the form membrane test with specific thicknesses as described herein) for appropriate at least water permeability (ventilative property) and moisture-vapor transmission (MVTR) greater than 200g/m ²/ day, preferred MVTR is 800g/m ²/ day ventilative property, or more preferably 1200-(containing) 1400g/m ²/ day, even preferred MVTR is at least 1500g/m ²/ sky, 2100g/m at the most ²The ventilative property of/day (containing), most preferably applying agent or material is 2100g/m for having MVTR ²/ sky or the higher ventilative property of height.

Additionally mix filler such as granule, oil, solvent, plasticizer, surfactant, dispersant for giving elastomeric polymer required performance, can choosing wantonly.

It is believed that above-mentioned mechanical performance is the feature that is fit in some embodiment of film forming polymer of coating.Polymer can be hydrophobicity or hydrophilic.Yet with regard to quick humidification, polymer preferably also is a hydrophilic.

Film forming polymer for example can solution or aqueous solution apply, or can dispersion apply in another embodiment, or apply with aqueous dispersion in preferred embodiments.Solution can use for example acetone, isopropyl alcohol, oxolane, methyl ethyl ketone, dimethyl sulfoxine, dimethyl formamide, chloroform, ethanol, methanol and composition thereof the preparation of any suitable organic solvent.

Polymer also can be before applying each solution of blend or each dispersion and blend.Especially, itself do not satisfy flexible standard or permeability standards polymer can with the polyblend of satisfying these standards, and produce the blend be applicable to coating of the present invention.

The suitable elastomeric polymer that can solution applies for example is Vector ^4211 (DexcoPolymers, Texas, USA), Vector 4111, Septon 2063 (SeptonCompany of the U.S., A Kuraray Group Company); Septon 2007, Estane ^58245 (USA), Estane 4988, Estane 4986, Estane for Noveon, Cleveland ^X-1007, Estane T5410, Irogran PS370-201 (Huntsman Polyurethanes), Irogran VP654/5, Pellethane 2103-70A (Dow Chemical Company), Elastollan ^LP9109 (Elastogran).

In the preferred embodiment, polymer is the aqueous dispersion form, and in more preferred, polymer is the aqueous dispersion of polyurethane.

The preparation example of the synthetic and dispersions of polyurethanes of polyurethane is as being described in detail in Ullmann ' sEncyclopedia of Industrial Chemistry, and the 6th edition, 2000, in the electronic edition.

Polyurethane is preferably hydrophilic, especially surface hydrophilicity.Surface hydrophilicity can be measured by method known to those skilled in the art.In preferred operations, hydrophilic polyurethane is the material of quilt liquid to be absorbed (0.9% saline, urine) moistening.Its feature can be contact angle less than 90 degree.The for example available Kr ü ss G10-G1041 available from German Kruess of contact angle measures based on the contact angle measuring device of video or with other method known in the art.

In preferred embodiments, hydrophilicity can be realized by the polyurethane that comprises following hydrophilic polymer block: for example have by ethylene glycol (CH ₂CH ₂O) or by 1,4-butanediol (CH ₂CH ₂CH ₂CH ₂O) or by propylene glycol (CH ₂CH ₂CH ₂O) or the polyether group of the deutero-group of its mixture part.Therefore, EU is preferred film forming polymer.The hydrophilic block wherein the part side chain or all side chain be that the mode of the comb polymer of hydrophilic polymer block constitutes.But the hydrophilic block also can constitute main chain (being polymer backbone).The preferred embodiment utilization is the polyurethane that exists with the side chain form of the major part of hydrophilic polymer block at least wherein.This side chain can be block copolymer such as polyethylene glycol-propylene glycol copolymers again.

For polyurethane, can also be by the rising ionic group, the content of optimization acid's salt group, sulfonate groups, phosphate group or ammonium and obtain hydrophilicity.Ammonium can be the uncle or the quaternary groups of protonated or alkanisation.Carboxylate groups, sulfonate groups and phosphate group can exist with alkali metal or ammonium salt.Suitable ionic group and precursor separately thereof for example are described in " UllmannsEncyclop  die der technischen Chemie ", and the 4th edition, the 19th volume in the 311-313 page or leaf, is described among DE-A 1 495 745 and the WO 03/050156 in addition.

The hydrophilic of optimization polyurethane helps the water infiltration and is dissolved in the water-absorbing polymeric particles of being sealed by film forming polymer.Be to be hydrophilic although have the remarkable part of the coating of the present invention of these optimization polyurethanes, in fact even under dampness also can too do not damage mechanical performance.

Preferred film forming polymer has two or more glass transition temperatures (being measured by DSC).It is desirable to, used polymer shows the phenomenon that is separated, be contain simultaneously in the polymer two or more a plurality of different blocks with low and high Tg (thermoplastic elastomer (TPE): A ComprehensiveReview, edit Legge, N.R., Holden, G., Schroeder, H.E., 1987, the 2 chapters).Yet, under the situation that several Tg are close together or because other experimentally, measures in fact unusual difficulty of Tg.Even can't be by testing under the clear situation about recording at Tg, polymer still may be suitable within the scope of the invention.

The polyurethane of the particularly preferred polymer that is separated, especially this paper comprises that one or more weight average molecular weight Mw is at least 5kg/mol, the block copolymer that is separated of preferred 10kg/mol at least and Geng Gao.

In one embodiment, this block copolymer has the polymeric first polymeric homopolymer section (block) and the second polymeric homopolymer section (block) mutually at least, the Tg of therefore preferred first (soft) section ₁Less than 25 ℃ or even less than 20 ℃, or even less than 0 ℃, and the Tg of second (firmly) section ₂Be at least 50 ℃, or 55 ℃ or higher, preferred 60 ℃ or higher, even 70 ℃ or higher.

In another embodiment, especially for polyurethane, this block copolymer has the polymeric first polymeric heteropolymer section (block) and the second polymeric heteropolymer section (block) at least mutually, the Tg of therefore preferred first (soft) section ₁Less than 25 ℃ or even less than 20 ℃, or even less than 0 ℃, and the Tg of second (firmly) section ₂Be at least 50 ℃, or 55 ℃ or higher, preferred 60 ℃ or higher, even 70 ℃ or higher.

In one embodiment, the weight average molecular weight of second (firmly) section (at least 50 ℃ of Tg) is 28kg/mol at least altogether preferably, or even 45kg/mol at least.

The preferable weight-average molecular weight of first (soft) section (Tg is less than 25 ℃) is at least 500g/mol, preferred 1000g/mol at least, or even 2000g/mol at least, but preferably less than 8000g/mol, preferably less than 5000g/mol.

Yet whole first (soft) section is generally the 20-95 weight % of whole block copolymer, or even 20-85 weight %, or more preferably 30-75 weight %, perhaps even 40-70 weight %.In addition, when soft section gross weight horizontal exceeding 70 weight %, even more preferably each weight average molecular weight of soft section less than 5000g/mol.

Those skilled in the art should fully understand be " polyurethane " for be used for describing by make two-or polyisocyanates with at least a two-or polyfunctional " containing reactive hydrogen " chemical compound react the general name of the polymer for preparing." contain reactive hydrogen " and be meant this two-or polyfunctional chemical compound have at least 2 isocyanate groups be reactive functional group (being also referred to as reactive group), for example hydroxyl, primary amino radical and secondary amino group and sulfydryl (SH).

What those skilled in the art also should fully understand is that polyurethane also comprises allophanate, biuret, carbodiimides,  oxazolidinyl, isocyanuric acid ester, uretdione and other keyed jointing except that carbamate and urea keyed jointing.

In one embodiment, block copolymer used herein is preferably EU and PAUR.Especially preferred is to comprise polyalkylene glycol mono unit, especially the unitary EU of Polyethylene Glycol unit or polytetramethylene glycol.

Term used herein " aklylene glycol " comprise aklylene glycol with 2-10 carbon atom and replacement aklylene glycol the two, as ethylene glycol, 1, ammediol, 1,2-propylene glycol, 1,2-butanediol, 1,3 butylene glycol, 1,4-butanediol, styrene glycol etc.

Polyurethane used according to the invention is usually by preparing polyisocyanates and the compound bearing active hydrogen reaction that contains with two or more reactive groups.These chemical compounds comprise:

A) molecular weight is preferably 300-100000g/mol, especially the high-molecular weight compounds of 500-30000g/mol

B) low molecular weight compound and

C) have polyether-based, especially polyoxyethylene thiazolinyl or PolyTHF base, and molecular weight is the chemical compound of 200-20000g/mol, this polyether-based does not have reactive group.

These chemical compounds also can use by mixture.

Suitable polyisocyanates on average has two or more isocyanate groups approximately, preferred average about 2 to about 4 isocyanate groups, and comprise aliphatic series, alicyclic, araliphatic and aromatic polyisocyanate, it is used separately or use with two or more mixture.More preferably vulcabond.Especially preferred is aliphatic series and alicyclic polyisocyanates, especially vulcabond.

The instantiation of suitable aliphatic vulcabond comprise α with 5-20 carbon atom-, ω-alkylidene vulcabond, as hexa-methylene-1,6-vulcabond, 1,12-dodecane vulcabond, 2,2,4-trimethyl hexamethylene diisocyanate, 2,4,4-trimethyl-hexamethylene diisocyanate, 2-methyl isophthalic acid, 5-pentamethylene diisocyanate etc.Can use the polyisocyanates that has less than 5 carbon atoms, but because of its high volatile volatile and toxicity more not preferred.Preferred aliphatic polyisocyanate comprises hexa-methylene-1,6-vulcabond, 2,2,4-trimethyl-hexamethylene diisocyanate and 2,4,4-trimethyl-hexamethylene diisocyanate.

The instantiation of suitable alicyclic diisocyanate comprises that dicyclohexyl methyl hydride diisocyanate (can be by Bayer Corporation with Desmodur ^W is commercial), isophorone diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-two (isocyanates ylmethyl) cyclohexane extraction etc.Preferred alicyclic diisocyanate comprises dicyclohexyl methyl hydride diisocyanate and isophorone diisocyanate.

Between the instantiation of suitable araliphatic vulcabond comprises-and tetramethyl eylylene diisocyanate, right-tetramethyl eylylene diisocyanate, 1,4-eylylene diisocyanate, 1,3-eylylene diisocyanate etc.Preferred araliphatic vulcabond is the tetramethyl eylylene diisocyanate.

The example of suitable aromatic diisocyanates comprises 4,4 '-methyl diphenylene diisocyanate, toluene di-isocyanate(TDI), their isomer, naphthalene diisocyanate etc.Preferred aromatic diisocyanates be toluene di-isocyanate(TDI) and 4,4 '-methyl diphenylene diisocyanate.

Have 2 or high-molecular weight compounds example a) of more a plurality of reactive groups for as the pure and mild polyether polyol of polyester polyols, and polyhydroxy polycarboxylic esteramides, the polycaprolactone of hydroxyl, the acrylic copolymer of hydroxyl, epoxide, polyhydroxy polycarboxylic carbonic ester, polyhydroxy polycarboxylic acetal, polyhydroxy polycarboxylic thioether, polysiloxane polyhydric alcohol, ethoxyquin polysiloxane polyhydric alcohol, polybutadiene polyol and hydrogenated butadiene polymer polyhydric alcohol, polyacrylate polyol, halogenated polyester and the polyethers etc. of hydroxyl, and composition thereof.Preferred polyester polyhydric alcohol, polyether polyol, polycarbonate polyol, polysiloxane polyhydric alcohol and ethoxyquin polysiloxane polyhydric alcohol.Special preferred polyester polyhydric alcohol, polycarbonate polyol, polyalkylene ethoxylated polyhydric alcohol.Functional group in the above-mentioned high-molecular weight compounds counts average per molecule and is preferably 1.8-3, especially 2-2.2 functional group.

PEPA is generally by making the excessive glycol of organic polycarboxylic acids or its anhydride and stoichiometry react the esterification products for preparing.The used glycol of preparation PEPA comprises for example ethylene glycol of aklylene glycol, 1,2-and 1, ammediol, 1,2-, 1,3-, 1,4-and 2, the 3-butanediol, hexanediol, neopentyl glycol, 1, the 6-hexanediol, 1,8-ethohexadiol, and other glycol such as bisphenol-A, cyclohexanediol, cyclohexanedimethanol (1,4-pair-the hydroxymethyl cyclohexane extraction), the 2-methyl isophthalic acid, ammediol, 2,2,4-trimethyl-1,3-pentanediol, diethylene glycol, 2,2'-ethylenedioxybis(ethanol)., tetraethylene glycol (TEG), Polyethylene Glycol, dipropylene glycol, polypropylene glycol, dibutylene glycol, polytetramethylene glycol, dimer diol, the hydroxylating bis-phenol, PTMEG, halogenation glycol etc. and composition thereof.Preferred glycol comprises ethylene glycol, diethylene glycol, butanediol, hexanediol and neopentyl glycol.Perhaps or in addition, also can use the sulfhydryl compound that is equal to.

The used suitable carboxylic of preparation PEPA comprises dicarboxylic acids and tricarboxylic acids and anhydride, for example maleic acid, maleic anhydride, succinic acid, 1,3-propanedicarboxylic acid, glutaric anhydride, adipic acid, suberic acid, 1,5-pentanedicarboxylic acid., Azelaic Acid, decanedioic acid, chlorendic acid, 1,2, the isomer of 4-butane-tricarboxylic acids, phthalic acid, phthalic acid, phthalic anhydride, fumaric acid, dimer (fatty acid) yl such as oleic acid etc. and composition thereof.The used preferred polybasic carboxylic acid of preparation PEPA comprises aliphatic series or aromatic diacid.

The suitable polyester examples of polyhydric alcohols comprises poly-(adipate diol ester), gather (ethylene glycol terephthalate) polyhydric alcohol, polycaprolactone polyol, phthalic acid polyhydric alcohol, sulfonation and the acidifying polyhydric alcohol of phosphine etc. and composition thereof.

The preferred polyester polyhydric alcohol is a glycol.The preferred polyester glycol comprises poly-(butanediol adipate ester), hexanediol adipic acid and M-phthalic acid polyester such as hexane adipate ester M-phthalic acid polyester; Hexanediol neopentyl glycol adipate polyester glycol, for example Piothane 67-3000 HNA (PanolamIndustries) and Piothane 67-1000 HNA, and propylene glycol maleic anhydride adipate polyester glycol such as Piothane SO-1000 PMA and hexanediol neopentyl glycol fumarate polyester glycol such as Piothane 67-SO0 HNF.Other preferred polyester glycol comprises Rucoflex ^S101.5-3.5, S1040-3.5 and S-1040-110 (Bayer Corporation).

Polyether polyol can be in a known way by making initial compounds such as water or the above-mentioned glycol that is used to prepare PEPA that contains hydrogen atoms, and aklylene glycol or cyclic ether such as ethylene glycol, propylene glycol, butanediol, styrene glycol, ethylene oxide, propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, oxetanes, oxolane, chloropropylene oxide etc. and composition thereof react and prepare.Preferred polyethers comprises Polyethylene Glycol, polypropylene glycol, PolyTHF and polyethylene glycol-propylene glycol copolymers.Polyethylene Glycol and polypropylene glycol can directly use or use with the physical blending thing.Under the situation that makes propylene oxide and ethylene oxide copolymerization, then these polytrimethylenes-poly-ethylidene copolymer can atactic polymer or block copolymer use.

In one embodiment, polyether polyol is the main polymer chain composition.

In another embodiment, Aethoxy Sklerol is the end group of main polymer chain.In another embodiment, polyether polyol is the composition of the side chain that is connected with the main polymer chain comb shape.This monomeric example is Tegomer D-3403 (Degussa).

Merlon comprises by dihydroxylic alcohols as 1, ammediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, 2,2'-ethylenedioxybis(ethanol)., tetraethylene glycol (TEG) etc. and composition thereof and dialkyl carbonate such as diethyl carbonate, diaryl carbonate such as diphenyl carbonate or phosgene reaction and obtain those.

Low molecular weight compound b with two reactive functional groups) example is glycol such as aklylene glycol and above-mentioned and relevant other glycol mentioned of preparation PEPA.They also comprise diamidogen such as diamidogen and polyamines, and they belong to the preferred compound that is used to prepare above-mentioned polyesteramide and polyamide.Suitable diamines and polyamines comprise 1, the 2-diaminoethanes, 1, the 6-diamino hexane, the 2-methyl isophthalic acid, the 5-pentanediamine, 2,2,4-trimethyl-1, the 6-hexamethylene diamine, 1,12-diaminourea dodecane, the 2-ethylaminoethanol, the 2-[(2-amino-ethyl) amino]-ethanol, piperazine, 2, the 5-lupetazin, 1-amino-3-amino methyl-3,5,5-trimethyl-cyclohexane (isophorone diamine or IPDA), two-(4-aminocyclohexyl)-methane, two-(4-amino-3-methyl-cyclohexyl base) methane, 1, the 4-diamino-cyclohexane, 1, the 2-propane diamine, hydrazine, urea, amino acid hydrazides, the hydrazides of half click Buckie carboxylic acid, bishydrazide and two semicarbazides, diethylenetriamines, trien, tetren, penten, N, N, N-three-(2-amino-ethyl) amine, N-(2-piperazinyl ethyl)-ethylenediamine, N, N '-two-(2-amino-ethyl)-piperazine, N, N, N '-three-(2-amino-ethyl) ethylenediamine, N-[N-(2-amino-ethyl)-2-amino-ethyl]-N '-(2-amino-ethyl)-piperazine, N-(2-amino-ethyl)-N '-(2-piperazinyl ethyl)-ethylenediamine, N, N-two-(2-amino-ethyl)-N-(2-piperazinyl ethyl) amine, N, N-two-(2-piperazinyl ethyl) amine, polymine, the imino group dipropylamine, guanidine, melamine, N-(2-amino-ethyl)-1, the 3-propane diamine, 3,3 '-diaminobenzidine, 2,4, the 6-Triaminopyrimidine, polyoxypropylene amine, 4 sub-propyl-5-amine, tri propylidene tetramine, N, N-two-(the amino hexyl of 6-) amine, N, N '-two-(3-aminopropyl) ethylenediamine and 2,4-two (4 '-aminobenzyl)-aniline etc. and composition thereof.Preferred diamidogen and polyamines comprise 1-amino-3-amino methyl-3,5,5-trimethyl-cyclohexane extraction (isophorone diamine or IPDA), two-(4-aminocyclohexyl)-methane, two-(4-amino-3-methylcyclohexyl)-methane, ethylenediamine, diethylenetriamines, trien, tetren and penten etc. and composition thereof.Other suitable diamines and polyamines for example comprise Jeffamine ^D-2000 and D-4000, they are the different end capped polypropylene glycol of amine of molecular weight only, and Jeffamine ^XTJ-502, T 403, T 5000 and T 3000, they are the end capped Polyethylene Glycol of amine, the end capped polypropylene glycol-ethylene glycol copolymer of amine and based on the triamine of propoxylated glycerol or trimethylolpropane and it is available from Huntsman Chemical Company.

Poly-(aklylene glycol) can be the part of main polymer chain or can be used as side chain and be connected with comb shape with main chain.

In preferred embodiments, polyurethane comprises poly-(aklylene glycol) side chain of capacity, and in final polyurethane, comprise about 10 weight % to 90 weight % based on dry weight, preferred about 12 weight % are to about 80 weight %, preferred about 15 weight % are to about 60 weight %, and more preferably from about 20 weight % are to poly-(aklylene glycol) unit of about 50 weight %.At least about 50 weight %, preferably at least about 70 weight %, more preferably poly-(aklylene glycol) side chain unit at least about 90 weight % comprises poly-(ethylene glycol), and poly-(aklylene glycol) unit of all the other side chains can comprise and has 3 aklylene glycol and substituted alkylene glycol to about 10 carbon atoms.Term " final polyurethane " is meant the polyurethane that is used to apply water-absorbing polymeric particles.

The amount of preferential side chain element (i) is at least about 30 weight % during less than about 600g/mol when the unitary molecular weight of side chain, (ii) when the unitary molecular weight of side chain be to be at least about 15 weight % 600 to about 1000g/mol the time approximately, and (iii) when the unitary molecular weight of side chain surpasses about 1000g/mol, be at least about 12 weight %.Mixture with active hydrogen-contg compound of this (aklylene glycol) side chain of birdsing of the same feather flock together can be used with the active hydrogen-contg compound that does not have this class side chain.

These side chains can be by using the polyether-based that has at least two reactive functional groups and do not contain reactive group, preferred polyalkylene ether, the more preferably compound c of polyethylene group) replace partly or whole above-mentioned high molecular weight diols a) or low molecular weight compound b) and mix in the polyurethane.

For example, have polyether-based, especially the active hydrogen-contg compound of poly-(aklylene glycol) base comprises as United States Patent (USP) the 3rd, 905, the glycol with poly-(ethylene glycol) base described in No. 929 (herein all being incorporated herein by reference).In addition, United States Patent (USP) the 5th, 700, No. 867 (herein all being incorporated herein by reference) the 4th hurdle the 3.5th walk to the 5th hurdle the 4.5th row and have instructed the method for mixing poly-(ethylene glycol) side chain.Three (methylol) propane list (polyethylene glycol oxide methyl ketone) of the active hydrogen-contg compound that preferably has poly-(ethylene glycol) side chain for obtaining with TegomerD-3403 by Degussa-Goldschmidt.

Preferably being ready to use in polyurethane of the present invention does not yet have described side chain and has about 50 usually to about 10000g/mol with at least a, preferred about 200 to about 6000g/mol, the more preferably from about active hydrogen-contg compound of 300 to about 3000g/mol wide range of molecular weights reaction.The suitable active hydrogen-contg compound that does not have described side chain comprises herein with compound a) and any amine and the polyhydric alcohol b) described.

According to a preferred embodiment of the invention, select active dydrogen compounds so that in the skeleton (main chain) poly-(ethylene glycol) unit based on the dry weight of final polyurethane less than about 25 weight %, be more preferably less than about 15 weight %, most preferably less than about 5 weight %, because poly-(ethylene glycol) unit of this main chain tends to cause the polyurethane particles swelling in the polyurethane aqueous dispersion body and the use hot strength of the goods that prepared by dispersions of polyurethanes is reduced.

The polyurethane that preparation has polyether lateral chain is known to those skilled in the art and extensively is described among the US 2003/0195293, it is incorporated herein by reference especially herein.

Therefore, the present invention also provides a kind of water absorbing material that comprises with the water-absorbing polymeric particles of elasticity film forming polyurethane-coated, and wherein polyurethane not only comprises the side chain with polyoxyethylene units, and also comprises polyoxyethylene units in the main chain.

Within the scope of the present invention, favourable polyurethane is for obtaining by at first preparing the prepolymer with isocyanate end, subsequently it being connected to together in the chain extension step.This is connected to together can be by water or by carrying out with the chemical compound reaction with at least one crosslinkable functionality.

Prepolymer obtains by making one of above-mentioned isocyanate compound and active dydrogen compounds reaction.Preferred prepolymer is by above-mentioned polyisocyanates, at least a compound c) and the optional at least a compound a that is selected from) and other active dydrogen compounds preparation b).

In one embodiment, the ratio of isocyanates and reactive hydrogen is generally about 1.3/1 to about 2.5/1, preferred about 1.5/1 to about 2.1/1 in forming the chemical compound of prepolymer, and more preferably from about 1.7/1 to about 2/1.

Polyurethane can additionally contain can carry out further cross-linking reaction and the optional functional group that can make its self-crosslinking.

Chemical compound with at least one extra crosslinkable functionality comprise have carboxyl, the mixture of carbonyl, amido, hydroxyl and hydrazide group etc. and these groups those.The amount of optional compound is generally about at the most 1 milliequivalent based on the final polyurethane dry weight of every g, and preferred about 0.05 to about 0.5 milliequivalent, and more preferably from about 0.1 to about 0.3 milliequivalent.

Be used for mixing the preferred monomers of isocyanate-terminated prepolymer for having general formula (HO) _xQ (COOH) _yHydroxyl-carboxylic acid, wherein Q is straight chain or the branched hydrocarbyl radical with 1-12 carbon atom, and x and y are 1-3.The example of this hydroxyl-carboxylic acid comprises citric acid, dihydromethyl propionic acid (DMPA), dimethylolpropionic acid (DMBA), hydroxyacetic acid, lactic acid, malic acid, dihydroxy malic acid, tartaric acid, hydroxy new pentane acid etc. and composition thereof.More preferably dihydroxy-carboxylic acid, most preferably dihydromethyl propionic acid (DMPA).

Other provides the suitable combination thing of bridging property to comprise TGA, 2,6-resorcylic acid etc. and composition thereof.

The prepolymer that optional neutralization has side carboxyl makes carboxyl change into carboxylate anion, therefore has the effect that improves water dispersible.Suitable nertralizer comprises tertiary amine, metal hydroxides, ammonia and other reagent well known to those skilled in the art.

As chain extender, water, on average has at least a the present invention of being applicable to of inorganic or organic polyamine, polyhydric alcohol, urea or its compositions of about 2 or more a plurality of uncle and/or secondary amino group.The organic amine that is suitable as chain extender comprise diethylenetriamines (DETA), ethylenediamine (EDA) ,-benzene two methanediamines (MXDA), amino ethyl ethanolamine (AEEA), 2 methyl pentamethylenediamine etc. and composition thereof.In the operation of the present invention, also suitable is propane diamine, butanediamine, hexamethylene diamine, cyclohexanediamine, phenylenediamine, toluenediamine, 3,3-dichloro-benzidine, 4,4 '-methylene-two-(2-chloroaniline), 3,3-two chloro-4,4-diaminodiphenyl-methane, sulfonation uncle and/or secondary amine etc. and composition thereof.Suitable inorganic and organic amine comprise the hydrazine of hydrazine, replacement and hydrazine reaction product etc. and composition thereof.Suitable polyhydric alcohol comprises having 2-12 carbon atom, and those of preferred 2-8 carbon atom are as ethylene glycol, diethylene glycol, neopentyl glycol, butanediol, hexanediol etc. and composition thereof.Suitable urea comprises carbamide and derivant thereof etc. and composition thereof.Preferred hydrazine most preferably uses with aqueous solution.The amount of chain extender is generally based on the isocyanates that can get and is about 0.5 to about 0.95 equivalent.

The polyurethane of branching may be favourable to a certain extent, but does not need the hot strength that keeps high and improve creep resistance (for example strain relaxation).This degree of branching can realize in the step process of prepolymer step or chain extension.For the branching in the chain extension step process, preferred chain extenders DETA, but also can use other amine that on average has about two or more uncles and/or secondary amino group.For the branching in the prepolymer step process, preferably use trimethylolpropane (TMP) and on average have other polyhydric alcohol that surpasses two hydroxyls.Branched monomer can exist with the amount of about at the most 4 weight % of polymer backbone.

Polyurethane is preferred film forming polymer.It can be applied on the water-absorbing polymeric particles by solution or dispersion.Aqueous dispersion most preferably.

Preferred polyurethane aqueous dispersion body is Hauthane HD-4638 (available from Hauthaway), Hydrolar ^HC 269 (available from Italian COlm), Impraperm ^48180 (available from German Bayer Material Science AG), Lurapret ^DPS (available from German BASF), Permax ^120, Permax 200 and Permax 220 (available from Noveon, Brecksville, OH), SyntegraYM2000 and Syntegra YM2100 (available from Dow, Midland, Michigan), Witcobond ^G-213, Witcobond G-506, Witcobond G-507, Witcobond 736 (available from Uniroyal Chemical, Middlebury, CT).

Specially suitable elasticity film forming polyurethane is described in detail in the following list of references and especially forms the part of the theme of the disclosure of invention.Hydrophilic especially thermoplastic polyurethane is by Noveon, Brecksville, and Ohio is with trade name Permax 120 ^, Permax 200 and Permax 220 sell, and be specified in " Proceedings International Waterborne High Solids Coatings; 32; 299; 2004 ", and be published in February, 2004 U.S. New Orleans's in " InternationalWaterborne, High-Solids, and Powder Coatings Symposium ".Its preparation is described in detail among the US 2003/0195293.In addition, US 4,190, and 566, the polyurethane described in US 4,092,286, US2004/0214937 and the WO 03/050156 especially forms the part of the theme of the disclosure of invention.

More especially, the mixture that described polyurethane can be mutual or to use, with the acquisition particularly advantageous performance relevant with hydrophilic, water penetration and mechanical performance with the mixture of other film forming polymer, filler, oil, water-soluble polymer or plasticizer.

The coating agent of this paper can preferably comprise filler reducing viscosity, as available from U.S. Noveon Inc., and 9911 Brecksville Road, Cleveland, the resin Estane58245-047P of OH44 141-3247 and Estane X-1007-040P.Perhaps, can before applying, this filler be added in suitable the elastomer polymer dispersion or solution, to reduce viscosity.Typical filler is Aerosil, but also can use following other listed inorganic disaggregation auxiliary agent.

Herein, the optimization polyurethane that is used to apply agent is strain hardening and/or strain crystallization.In the process that stress-strain is measured, observe strain hardening, and performance is remarkable when increasing fast with strain increase stress.It has been generally acknowledged that strain hardening is owing to the elongation generation bigger resistance of the orientation of the polymer chain in the film to draw direction causes.

Apply and apply agent so that the average thickness that the gained coating preferably has (thickness) surpasses 0.1 μ m, the average thickness of preferred coatings (thickness) be 1 micron (μ m) to 100 microns, preferred 1-50 micron, more preferably 1-20 micron, or even the 2-20 micron, or even 2-10 micron.

In one embodiment, coating is preferably at thickness and/or even in shape.Preferred average thickness makes that the ratio of minimum and maximum ga(u)ge is 1: 1 to 1: 5, preferred 1: 1 to 1: 3, or even 1: 1 to 1: 2, or even 1: 1 to 1: 1.5.

In another embodiment, this coating may present some defective (also being the hole), but polymer still shows very good enforcement performance of the present invention.In another embodiment of the present invention, coating can form fibrous network around absorbent particle.

The applied amount of polymeric film is preferably 0.1-25 weight portion film forming polymer (calculating with solid-state material) based on the dry water-absorbing polymeric particles of 100 weight portions.The film forming polymer amount that the water-absorbing polymeric particles of per 100 weight portions uses is preferably the 0.1-15 weight portion, 0.5-10 weight portion especially, more preferably 0.5-7 weight portion, even more preferably 0.5-5 weight portion, particularly 0.5-4.5 weight portion.

Be preferably based on the water-absorbing polymeric particles of 100 weight portions especially, by using＜5 weight portions, preferred 0.5-4.5 weight portion, especially 0.5-4 weight portion, more preferably 0.5-3 weight portion film forming polymer is preferably at 0 ℃ to＜50 ℃, preferred 0 ℃ to＜45 ℃, more preferably 10 ℃ to＜40 ℃, most preferably apply water-absorbing polymeric particles under 15 ℃ to＜35 ℃ the temperature, then the granule that heat treatment applies under the temperature more than 50 ℃ and the water absorbing material that obtains.

Film forming polymer, especially polyurethane can solid materials, hot melt, dispersion, aqueous dispersion, aqueous solution or organic solution are applied on the granule of suction addition polymer.Film forming polymer, especially polyurethane are applied to form on the water-absorbing polymeric particles and are preferably solution or more preferably aqueous dispersion.

The solvent that can be used for polyurethane comprises can set up 1 solvent to the polyurethane concentration that is not less than 40 weight % in each solvent or mixture.The example that can mention is alcohol, ester, ether, ketone, amide and halogenated hydrocarbons, as methyl ethyl ketone, acetone, isopropyl alcohol, oxolane, dimethyl formamide, chloroform and composition thereof.Particularly advantageous is polarity, proton inertia and boiling point less than 100 ℃ solvent.

The moisture mixture that is meant water and water and is at most the water miscibility solvent of 20 weight % based on the total amount of solvent herein.The water miscibility solvent can mix with the water-soluble of institute expense under 25 ℃ and 1 crust.They comprise alcohol as methanol, ethanol, normal propyl alcohol, isopropyl alcohol, ethylene glycol, 1,2-propylene glycol, 1, ammediol, ethylene carbonate, glycerol and methyl cellosolve and water-soluble ethers such as oxolane and two  alkane.

Particularly advantageous is to apply in fluidized-bed reactor.Depend on the type of reactor, absorbent particle is introduced as usually, and apply by the film forming polymer of spraying usually with solid material or preferred polymers solution or dispersion.The aqueous dispersion of film forming polymer most preferably for this reason.

A) in fluidized-bed reactor, preferably with continuity method, at 0-50 ℃, preferably be lower than 45 ℃ down with elasticity film forming polymer spray application water-absorbing polymeric particles and

B) granule that heat treatment applies under the temperature more than 50 ℃.

Preferably extremely dense by polyurethane solutions or dispersion that spray application applies.For this reason, the viscosity of this polyurethane mixture is essential can not be too high, otherwise dialogue polyurethane solutions or dispersion no longer can fine dispersion to be used for spraying.Polyurethane solutions that preferred viscosities is following or dispersion:＜500mPa.s, preferably＜300mPa.s, more preferably＜100mPa.s, even more preferably＜10mPa.s, most preferably＜5mPa.s (measure dispersions of polyurethanes under shear rate 〉=200rpm usually by the usefulness rotating cylinder viscometer, specially suitable is Haake rotating cylinder viscometer RV20 type, system M5, NV).

In the embodiment of using other film forming polymer, preferably these film forming polymers show the viscosity identical with polyurethane when applying.

Polyurethane concentration in polyurethane solutions or the dispersion is generally 1-60 weight %, preferred 5-40 weight %, especially 10-30 weight %.The also more dilution of height, but cause usually the longer coating time.The particularly advantageous advantage of dispersions of polyurethanes is even also has lower viscosity under high concentration and high molecular.

Available fluidized-bed reactor for example comprises fluid bed or the suspension bed coating machine of knowing in the pharmaceuticals industry.Preferred especially Wurster method or Glatt-Zeller method and these methods for example are described in " Pharmazeutische Technologie; Georg Thieme Verlag; the 2nd edition (1989); the 412-413 page or leaf " and " Arzneiformenlehre; WissenschaftlicheVerlagsbuchandlung mbH; Stuttgart 1985, the 130-132 pages or leaves " in.Specially suitablely on commercial scale be described in Drying Technology with continuous fluidized bed method in batches, 20 (2), among the 419-447 (2002).

In the Wurster method, the absorbent polymer particles stream of the carrier gas by making progress and opposing gravity in central canal are carried secretly by at least one nozzle, and with finely divided polymer solution or dispersion and stream spraying.Granule falls go back to the bottom along sidewall subsequently, compiles in the bottom, and is carried secretly the process central canal and passed through nozzle by carrier gas stream once more.Nozzle usually from bottom spray to fluid bed, it also can drop into fluid bed from the bottom.

In the Glatt-Zeller method, polymer beads is carried with the direction that makes progress along wall by the carrier gas of outside, to fall on the central nozzle head in the centre then, this nozzle head comprises at least 3 double nozzles that are sprayed to side usually.Therefore granule is sprayed from side, falls into the bottom and is taken up from the bottom by carrier gas once more by nozzle head, makes and restarts circulation.

The common trait of these two kinds of methods is that granule repeats to carry secretly by sprayer unit with the form of fluid bed, therefore can apply as thin as a wafer and very uniform usually shell.In addition, in all use if having time carrier gas, carrier must be infeeded and moves to keep particulate fluidisation with sufficiently high speed.The result be in addition at low temperatures liquid can be in device vaporization fast, the solvent in the dispersion (being water) for example, so the polymer beads of dispersion is deposited on the absorbent polymer particles surface to be coated.Useful carrier gas comprises the mixture of above-mentioned noble gas and air or dry air or any of these gas.

The appropriate flow fluidized bed reactor is according to making film forming polymer solution or dispersion finer atomization, and drop in fluid bed with the water-absorbing polymeric particles random collision, therefore form basic shell uniformly gradually, and in collision back repeatedly operate uniformly.The size of drop must be less than the granularity of absorbing agent polymer.Drop size is by bleed type, spray condition, i.e. and temperature, concentration, viscosity and pressure decision, typical drop size is 10-400 μ m.Usually find that the polymer particle size and the ratio of drop size are at least 10.The droplet that preferably has narrow size distribution.Flow and stream is introduced with the polymeric dispersions of atomizing or the drop of solution or with particulate, perhaps enter in the grain flow from the side, and also can be from top-spray to fluid bed.Thus, follow this principle and can set up other device and this effect of all very suitable generation of improvement of equipment of fluid bed equally.

An embodiment for example is a cylinder type fluid bed batch reactor, wherein water-absorbing polymeric particles is flowed to conveying from installing inner outer wall by carrier gas, and from one or many places with the spraying film forming polymer add this fluid bed from side, therefore there is not carrier gas stream in the center of device at all, granule falls once more, the cube agitator is moved and whole fluidized particles is distributed again.

Other embodiment for example can be Schuggi blender, turbulator or plow mixers, and it can use separately or preferred assembly use with a plurality of series units.If use this blender separately, then water absorbent polymer may must repeatedly infeed by device, evenly applies to become.If set up two or more this devices, then by once just enough with series unit.

In another embodiment, use continuously or the in batches spraying-blender of Telschig-type, wherein free-falling in-flight granule is hit in spraying, and the granule repeated exposure is in spraying.Suitable blender is described in Chemie-Technik, and 22 (1993), the 4th phase, the 98th page and subsequently in each page.

In preferred embodiments, use the continuous fluid bed process, and with top or bottom-pattern operation spraying.In particularly preferred embodiment, spraying is continuous with operation of bottom pattern and method.Suitable device for example is described in US 5,211, in 985.Appropriate device for example also can be buied with series connection GF (continuous fluidized bed) and the spouted bed of ProCell  by GlattMaschinen-und Apparatebau AG (Switzerland).The simple seam of spouted bed technique use replaces the sieve end with the generation fluid bed, and especially is fit to be difficult to fluidizing material.

In other embodiments, it also may wish with top-and bottom-pattern operation spraying, maybe may wish to spray from side or from the combination of several different spray position.

The inventive method utilization is usually used in the crosslinked said nozzle in back.Yet, preferred especially double nozzle.

The inventive method is preferably used the Wurster coating machine.The example of this coating machine can be buied and at the PRECISION COATERS of Coating Place Inc. (Wisconsin, the U.S.) assembling by GEA-Aeromatic Fielder AG (Switzerland) ^TM

Advantageously select the fluidized bed airflow that enters from below equally, so that whole equal fluidisations in device of the water-absorbing polymeric particles of amount.The gas velocity of fluid bed is higher than minimum fluidization rate (measuring method is described among the Kunii and Levenspiel " Fluidization engineering " 1991), and, preferably surpass minimum fluidization rate 10% less than the final speed of water-absorbing polymeric particles.The gas velocity of Wurster pipe surpasses the final speed of water-absorbing polymeric particles, usually less than 100 meter per seconds, preferably surpasses final speed 10%.

Air-flow makes water or solvent vaporization.In preferred embodiments, select the coated conditions of air-flow and temperature, so that air-flow is at the relative humidity or the saturated with vapor degree in exit, based on suitable absolute humidity in vogue in the carrier gas under the uniform temp or the suitable absolute saturated vapor pressure of words, be 10-90%, preferred 10-80% or preferred 10-70%, especially 30-60%.

Fluidized-bed reactor can be made by rustless steel or any other typical material that is used for this reactor, and parts that also can the product contact are rustless steel, to allow with an organic solvent and high temperature.

In another preferred embodiment, the inner surface of fluidized-bed reactor at least partly is coated in 25 ℃ and surpasses 90 ° material with the contact angle of water down.The example of this material is politef or polypropylene.The parts of all contact products of preferred embodiment all apply this material.

Yet the selection of material that is used for the contact product parts of device depends on that also these materials are whether to used polymeric dispersions or solution or treat coated polymer and present strong bonding.Preferably select for use and treat coated polymer or polymeric dispersions or solution and do not have this adherent material, to avoid caking.

According to the present invention, at 0-50 ℃, preferred 5-45 ℃, especially 10-40 ℃, most preferably apply under 15-35 ℃ in product and/or carrier gas temperature.

In preferred embodiments, before heat treatment step, the disaggregation auxiliary agent is added in the granule to be coated or that preferably applied.The disaggregation auxiliary agent is known to those skilled in the art, as is selected from the water-insoluble salt in small, broken bits of organic and inorganic salt and composition thereof, and wax and surfactant.Water-insoluble salt in this article refer to pH be in 7 the water dissolubility less than 5g/l, preferably less than 3g/l, especially less than 2g/l, most preferably less than the salt of 1g/l (under 25 ℃ and 1 crust).Use water-insoluble salt can reduce by film forming polymer, the viscosity that causes of polyurethane especially, this takes place in heat treatment process.

Water-insoluble salt can solid material or the form of dispersion use, preferably use with the form of aqueous dispersion.Solid is usually by carrier gas, in thin dirt jetting device.Dispersion is preferably by high speed agitator, by preparing dispersion at first step by solid material and water, and in second step it introduced fast in fluid bed (preferably via nozzle) and applies.Preferred two steps are all carried out in same apparatus.Suitable, aqueous dispersion can apply with polyurethane (or other film forming polymer), or via nozzle independently so that independently dispersion and polyurethane do not apply simultaneously or with polyurethane simultaneously.Particularly preferably in be applied to after the membrane polymer and subsequently heat treatment step before apply the disaggregation auxiliary agent.

Suitable cation for example is Ca in the water-insoluble salt ²⁺, Mg ²⁺, Al ³⁺, Sc ³⁺, Y ³⁺, Ln ³⁺(wherein Ln represents lanthanide series), Ti ⁴⁺, Zr ⁴⁺, Li ⁺, K ⁺, Na ⁺Or Zn ²⁺Suitable inorganic anion counter ion counterionsl gegenions for example are carbonate, sulfate radical, bicarbonate radical, former phosphate radical, silicate, oxonium ion or hydroxyl.When salt occurs with various crystal forms, then should comprise all crystal forms of salt.The water-insoluble inorganic salt is preferably selected from calcium sulfate, calcium carbonate, calcium phosphate, calcium silicates, calcium fluoride, apatite, magnesium phosphate, magnesium hydroxide, magnesium oxide, magnesium carbonate, dolomite, lithium carbonate, lithium phosphate, zinc oxide, zinc phosphate, the oxide of lanthanide series, hydroxide, carbonate and phosphate, sodium sulfate lanthanum, Scium sulfate (Sc2(SO4)3), Yttrium sesquisulfate, lanthanum sulfate, Scium trihydroxide., Scia, aluminium oxide, hydrated alumina and composition thereof.Apatite is meant fluor-apatite, hydroxyapatite, chlorapatite, carbonate-apatite and carbonate fluor-apatite.Specially suitable is calcium and magnesium salt such as calcium carbonate, calcium phosphate, magnesium carbonate, calcium oxide, magnesium oxide, calcium sulfate and composition thereof.Amorphous or crystalline aluminium oxide, titanium dioxide and silicon dioxide also are suitable.These disaggregation auxiliary agents also can their hydrated form use.Useful disaggregation auxiliary agent further comprises many clays, Talcum and zeolite.Silicon dioxide preferably uses with its unformed form, for example hydrophilic or hydrophobicity Aerosil ^, also can select to use commercially available aqueous silica sol, as granularity the Levasil of 5-75nm ^Kiselsole (H.C.Starck GmbH).

The particle mean size of water-insoluble salt in small, broken bits preferably less than 100 μ m, especially less than 50 μ m, is more preferably less than 20 μ m, even is more preferably less than 10 μ m, most preferably less than 5 μ m usually less than 200 μ m.Usually use even thinner fumed silica,,, even be more preferably less than the primary particle size of 20nm preferably less than 30nm for example less than 50nm.

In preferred embodiments, the consumption of water-insoluble salt in small, broken bits is 0.001-20 weight % based on the weight of water absorbent polymer, preferably less than 10 weight %, and especially 0.001-5 weight %, more preferably 0.001-2 weight %, most preferably 0.001-1 weight %.

Can replace or except that above-mentioned inorganic salt, also can use other known disaggregation auxiliary agent, example is a wax, and preferably through the Tissuemat E of micronization or preferred partial oxidation, the form that it equally can aqueous dispersion is used.This wax is described among the EP 0 755 964, is introduced into as a reference especially herein.

In addition, for realizing disaggregation, another polymeric dispersions of available high Tg (＞50 ℃) carries out applying the second time.

Useful disaggregation auxiliary agent further comprises stearic acid, and stearate is magnesium stearate, calcium stearate, zinc stearate, aluminium stearate and other polyoxyethylene-20-anhydrosorbitol ether monolaurate and PEG400 monostearate for example.

Useful disaggregation auxiliary agent comprises surfactant equally.Surfactant can use separately or with one of above-mentioned disaggregation auxiliary agent, the preferred water insoluble salt mix to use.

Described adding can be carried out with polyurethane, carry out before adding polyurethane or after adding polyurethane.Usually can before heat treatment, add.In the crosslinked operating process in back, can further apply surfactant.

Useful surfactant comprises nonionic, anion and cationic surfactant and composition thereof.Water absorbing material preferably comprises non-ionic surface active agent.Useful non-ionic surface active agent for example comprises sorbitan esters such as anhydrosorbitol and C ₈-C ₁₈Carboxylic acid such as lauric acid, Palmic acid, stearic acid and oleic list-, two-or three esters; Poly-sorbitol ester; Has 8-22 in the alkyl chain, preferred 10-18 carbon atom and have 1-20, preferably 1.1-5 the unitary alkyl polyglucoside of glucoside; The N-alkyl glucose amide; Alkylamine alcoxylates or alkylamide ethoxylate; Oxyalkylated C ₈-C ₂₂Alcohol is as fatty alcohol alkoxy compound or oxo process alcohol alkoxylates; The block polymer of ethylene oxide, propylene oxide and/or butylene oxide; Has C ₆-C ₁₄The alkylphenol ethoxylate of alkyl chain and 5-30mol ethylene oxide unit.

The amount of surfactant is generally 0.01-0.5 weight % based on the weight of water absorbing material, preferably less than 0.1 weight %, especially less than 0.05 weight %.

According to the present invention, heat treatment preferred 100-200 ℃, especially carries out under 120-160 ℃ the temperature more than 50 ℃.Do not wish bound by theory, this heat treatment causes the film forming polymer that applies, and optimization polyurethane flows and forms polymeric film, makes the polymer chain mat thus.The heat treatment persistent period is depended on the glass transition temperature and the melt temperature of selected heat treatment temperature and film forming polymer.Usually the heat treatment time of finding 30-120 minute is enough.Yet, when for example heat treatment was less than 30 minutes in fluidized bed dryer, also can finishes required polymeric film and form.Certainly the time can be longer, but especially may cause polymeric film or water absorbing material impaired under higher temperatures.

Heat treatment is for example at downstream fluidized bed dryer, tunnel dryer, tower disc type exsiccator, tower drier, one or more heating spiral rod or pan dryer or Nara ^Carry out in the exsiccator.Heat treatment more preferably directly carries out in the Wurster coating machine preferably at fluidized-bed reactor.

Heat treatment can carry out on tower tray in forcing air-oven.Need handle the polymer that applies with the disaggregation auxiliary agent this moment before heat treatment.Perhaps, can the antiseized coating of tower tray be placed on the polymer that applies on the tower tray with individual particle, then to avoid sintering together.

In a embodiment, can in each step, use air or dry air about coating, heat treatment and refrigerative method step.

In another embodiment, can use noble gas at one or more these method steps.In another embodiment, can use the mixture of air and noble gas at one or more these method steps.

Heat treatment preferably carries out in noble gas.Preferred especially coating step also carries out in noble gas.Very particularly preferably last cooling stage also carries out in protective gas.Therefore, preferred a kind of wherein method of production water absorbing material of the present invention in noble gas.

It is believed that the water absorbing material that obtains by the inventive method can be centered on by uniform films.Depend on based on the coating speed of absorbent polymer particles and the mode that applies, can expect that polymeric film can not interrupt fully, and have unlapped zone such as island.This embodiment is also included among the present invention.The coating that crackle for example has the hole is not disadvantageous, although in the coating crackle is arranged as long as the coating of superabsorbent polymer particles makes, occurs in the swelling of the water-absorbing polymeric particles that applies and the basic similarly mechanical force of basic flawless coating.The hydrophilic of polymer plays less effect in this embodiment.For example can provide a kind of method that increases absorbed speed required for protection, and can be used as the advantage use by in dispersion, using filler or polymeric additive deliberately to mix this defective.Advantageously coating can comprise water soluble filler, and it can dissolve in the swelling process of the water absorbing material that applies subsequently.

Usually find flawless and the granule of crackle arranged and deposit that this can arrive by the colouring method microexamination.

In this case, maybe advantageously the back is crosslinked as mentioned above with absorbent polymer particles.The crosslinked water-absorbing polymeric particles in back may be configured as membrane polymer, especially polyurethane-coated.Also can apply the back cross-linking agent before heat treatment, promptly with film forming polymer, especially polyurethane takes place in fluid bed simultaneously, or carries out after applying the film forming polymer step.In the flexible program of back, this can preferably add the disaggregation auxiliary agent simultaneously and carry out.In all cases, heat treatment preferably carries out under 120-160 ℃ temperature.

After heat treatment step finishes, with exsiccant water absorbent polymer material cooled.For this reason, preferably warm and exsiccant polymer is imported continuously in the trip cooler.This cooler for example can be disc type cooler, Nara vane type cooler or screw rod cooler.By the agitating element that suitable cooling medium such as warm water or cold water flow through wall or suitable words cooler is cooled off.Can be preferably the aqueous solution or the dispersion of water or additive be sprayed in the cooler, this can improve cooling effectiveness (making the water section evaporation), and the residual moisture content of end product can tune to 0-15 weight %, preferred 0.01-6 weight %, most preferably 0.1-3 weight %.The residual moisture content that increases descends the dust content of product, and helps to quicken swelling during with liquid, aqueous the contact at this water absorbing material.The example of additive is triethanolamine, surfactant, silicon dioxide or aluminum sulfate.

Yet, choose wantonly and can only use cooler to cool off, and in the blender that the downstream separates, add entry and additive.Reducing the cooling of product temperature only proceeds in the feasible plastic bag of product easily can being packed into or the degree in the cabin truck.Cooled product temperature preferably less than 60 ℃, most preferably less than 40 ℃, preferably is higher than-20 ℃ usually less than 90 ℃.

The preferred fluidized bed cooler that uses.

If apply and heat treatment all carries out in fluid bed, then two operations can be carried out in the device that separates or carry out in a device with communication chamber.If cooling is also carried out in fluidized bed cooler, then can in the device that separates, carry out or optional and other two steps merge and just carry out in a device with the 3rd reative cell.More a plurality of reative cells also are fine, and are carrying out some step such as coating step if desired in a plurality of chambers that connect successively mutually, thus make water-absorbing polymeric particles in each chamber by making granule be created as the membrane polymer shell continuously by each chamber successively.

The preferred water absorbing material that can obtain by the method that comprises the steps:

A) in fluidized-bed reactor, under 0-50 ℃, under preferred 0-45 ℃ the temperature with elasticity film forming polymer dispersion spraying water-absorbing polymeric particles and

B) the optional granule of using the disaggregation auxiliary agent to apply and obtain according to a), and subsequently

C) granule that heat treatment applies under the temperature more than 50 ℃, and subsequently

D) heat treated granule is cooled to below 90 ℃.

The absorbent particle that applies can with other grain fraction such as fiber, (fibrous) glue, organic or inorganic packing material or flow promortor, processing aid, anti-caking agent, odor control additive, coloring agent is given the coating of wet viscosity, and mixing such as hydrophilic surface coating are present in the water absorbing material of the present invention.

Usually can obtain water absorbing material by the method that is described in herein, the gained material is generally solid; It comprises known form in gel, sheet, fiber, aggregation, bulk, microgranule, granule, ball and other the water absorbent polymer field of describing hereinafter.

Absorbent material of the present invention preferably comprises the water less than 20 weight %, or even less than 10%, or even less than 8%, or even less than 5%, or even not moisture.The water content of absorbent material can be measured by Edana test number ERT 430.1-99 (in February, 1999), and it is included in, and dry absorbent material also passed through the dried weight loss determining water content of absorbent material in 3 hours under 105 ℃ Celsius.

Absorbent material can comprise two-layer or more multi-layered coating agent (shell), and it can obtain by twice of absorbable polymer of coating or more times.This can be identical coating agent or different coating agent.Yet, because economically, preferably have film forming polymer, the single coating of optimization polyurethane.

The remarkable part of water absorbing material of the present invention is to have erose granule and takes round shape/form under swollen state when drying, because the swelling of absorbent cores distributes via the resilience force of lip-deep elastomeric polymer shell, and thus, in this swelling process and in use the elastomeric polymer shell keeps its performance substantially.The film forming polymer of sealing, especially polyurethane are that saline is infiltrative, so polymer beads excellent absorption value of acquisition in CS-CRC (the centrifugal reserve capability of core shell) test, and obtain good penetration in the CS-SFC test.

The preferred centrifugal reserve capability of core shell (CS-CRC) value is not less than 20g/g, preferably is not less than the water absorbing material of 25g/g.

Equally preferably wherein CS-CRC and CS-SFC (core shell saline flow conductivity) satisfy water absorbing material with lower inequality: Log (CS-SFC '/150)＞3.36-0.133 * CS-CRC, wherein CS-SFC '=CS-SFC * 10 ⁷, and 150 dimension is [cm ³S/g].

Equally preferably wherein CS-CRC and CS-SFC (core shell saline flow conductivity) satisfy water absorbing material with lower inequality: Log (CS-SFC '/150)＞2.5-0.095 * CS-CRC, wherein CS-SFC '=CS-SFC * 10 ⁷, and 150 dimension is [cm ³S/g].

In addition, water absorbing material by the inventive method preparation has high wet porosity, in case promptly this means and make a certain amount of water absorbing material of the present invention absorb liquid and swelling, it can form (water) gel or (water) gel bed usually, especially compare with uncoated water-absorbing polymeric particles, it has specific wet porosity, wherein porosity US 5, the disclosed PHL experimental measurement of 562,646 (herein being incorporated herein by reference); If water absorbing material and the described different pressure of water-absorbing polymeric particles and test method is test down, then answer corresponding adjusting to be used for the weight of this test.

In addition, the water absorbing material by the inventive method preparation can be with CS-SFC experimental measurement as herein described, has high osmosis for the liquid of the gel bed of flowing through.

The water absorbing material that is also referred to as the polymer that forms hydrogel is hereinafter tested by following method of testing.

Method:

Measurement should be carried out under the relative humidity of 23 ± 2 ℃ ambient temperature and 50 ± 10%, except as otherwise noted.Before measurement, water-absorbing polymeric particles is fully mixed.For following method, AGM is meant " absorbent gel rubber material " and can be relevant with water-absorbing polymeric particles and water absorbing material.Implication is separately clearly defined by the data that provide in following examples.

CRC (centrifugal reserve capability)

This method is measured the free swell of hydrogel in the tea bag.Be to measure CRC: with 0.2000 ± 0.0050g dried hydrogel (particle size fraction 106-850 μ m or as following embodiment in concrete regulation) be weighed in the tea bag that is of a size of 60 * 85mm, subsequently with its sealing.Tea bag was placed 30 minutes in 0.9 excessive weight % sodium chloride solution (0.83L sodium chloride solution/1g polymer powder at least).Then with tea bag under 250g centrifugal 3 minutes.Measure amount of liquid by the tea bag of weighing after centrifugal.The test method No.441.2-02 (EDANA=EuropeanDisposables and Nonwovens Association) that this program is recommended corresponding to EDANA.Tea bag material and centrifugal and evaluation have wherein also been defined.

CS-CRC (the centrifugal reserve capability of core shell)

CS-CRC all fours CRC carries out, and difference is that the sample swelling time was extended for 240 minutes by 30 minutes.

AUL (absorbance under the 0.7psi load)

Be similar to the absorbance of recommending by EDANA (European Disposables and Nonwovens Association) under the load of the method for testing No.442.2-02 of the absorption under pressure mensuration, the authentic sample of the particle size distribution that difference has been for each examples measure to have in an embodiment to be reported.

The measuring cell that mensuration AUL 0.7psi uses is internal diameter 60mm, the lucite cylinder of height 50mm.What stick to cylinder bottom is at the bottom of mesh size is the stainless steel sift of 36 μ m.Measuring cell comprises that also diameter is the plastic plate of 59mm, and the counterweight that can put into measuring cell with plastic plate.The gross weight of plastic plate and counterweight is 1345g.For measuring AUL 0.7psi, have the weight of machine glass cylinder and plastic plate in vain by measurement, and be recorded as W _oThe polymer (particle size distribution: 150-800 μ m or as the concrete report of following embodiment institute) that then 0.900 ± 0.005g is formed hydrogel be weighed in the lucite cylinder and be distributed in stainless steel sift very equably at the bottom of on.Then, poly (methyl methacrylate) plate is carefully put into the lucite cylinder, the whole assembly and be recorded as W of weighing _aThen, the weight agate is placed on the plastic plate of lucite cylinder.With diameter is that 120mm, high 10mm and porosity are 0 ceramic filter plate (Duran, available from Schott) to place diameter be 200mm, highly be the Petri dish central authorities of 30mm, and 0.9 weight % sodium chloride solution of introducing capacity, flat to liquid surface and screen plate surface, but not wet screen plate surface.Then, be that the circular filter paper of 90mm and pore size＜20 μ m is (available from Schleicher﹠amp with diameter; The S﹠amp of Sch ü ll; S 589 Schwarzband) place on the ceramic wafer.Then, the lucite cylinder that will comprise the polymer that forms hydrogel places on the filter paper with plastic plate and counterweight, and places 60 minutes.The time then, from filter paper and Petri dish, take out whole assembly, from the lucite cylinder, take out counterweight subsequently.The lucite cylinder that will comprise the swelling hydrogel is weighed with plastic plate, and is W with weight record _b

According to the absorbance (AUL) under the following formula computational load:

AUL 0.7psi[g/g]＝[W _b-W _a]/[W _a-W _o]

AUL 0.3psi and 0.5psi measure under appropriate low pressure similarly.

CS-AUL (the core shell absorbance under load 0.7psi)

The measuring cell that mensuration CS-AUL 0.7psi uses is internal diameter 60mm, the lucite cylinder of height 50mm.Stick to cylinder bottom be at the bottom of mesh size is the stainless steel sift of 36 μ m (steel 1.4401, wire diameter 0.028mm is available from Weisse﹠amp; Eschrich).Measuring cell comprises that also diameter is the plastic plate of 59mm, and the counterweight that can put into measuring cell with plastic plate.The gross weight of plastic plate and counterweight is 1345g.For measuring AUL 0.7psi, have the weight of machine glass cylinder and plastic plate in vain by measurement, and be recorded as W _oThe polymer (particle size distribution: 150-800 μ m or as the concrete report of following embodiment institute) that then 0.900 ± 0.005g is formed hydrogel be weighed in the lucite cylinder and be distributed in stainless steel sift very equably at the bottom of on.Then, plastic plate is carefully put into the lucite cylinder, the whole assembly and be recorded as W of weighing _aThen, the weight agate is placed on the plastic plate of lucite cylinder.With diameter is that the circular filter paper of 90mm is (available from Schleicher﹠amp; The No.597 of Sch ü ll) places the center of 500ml crystallizing pan (available from Schott) of diameter 115mm and height 65mm.Introduce the sodium chloride solution of 200ml0.9 weight % then, the lucite cylinder that will comprise the polymer that forms hydrogel then places on the filter paper with plastic plate and counterweight, and places 240 minutes.The time then, from filter paper and Petri dish, take out whole assembly and drain 5 seconds of liquid of adhering to.From the lucite cylinder, take out counterweight subsequently.The lucite cylinder that will comprise the swelling hydrogel is weighed with plastic plate, and is W with weight record _b

AUL 0.7psi[g/g]＝[W _b-W _a]/[W _a-W _o]

AUL 0.3psi and 0.5psi measure under appropriate low pressure similarly.

Saline water conservancy diversion rate (SFC)

Measuring the infiltrative method of swell gel layer is " saline water conservancy diversion rate ", is also known as " gel layer permeability ", and is described among the EP A 640 330.As described below improvement of equipment that this method is used.Fig. 1 has shown the permeability measurement device by the open-ended tube A that is used for air admission, the hole B that clogs that recharges usefulness, constant hydrostatic head storage tank C, laboratory jack D, carrier pipe E, piston F, ring-type stand type support G, receiving vessel H, balance I and SFC device L assembling.

Fig. 2 shows the SFC device L that is made up of metal counterweight M, plunger axis N, lid O, center plunger P and cylinder Q.The internal diameter of cylinder Q is 6.00cm (area=28.27cm ²).(mesh width: 0.036mm, wire diameter: 0.028mm), rustless steel wire screen is tight through biaxial stretch-formed strand before connecting to rustless steel wire screen for the bottom faces of cylinder Q.Plunger is made up of the plunger axis N of diameter 21.15mm.The diameter of top 26.0mm is 15.8mm, forms the center plunger P of the axle collar, perforation, and it also uses tensile stainless steel mesh (mesh width: 0.036mm, wire diameter: 0.028mm) cover, and ring-type rustless steel counterweight M.Ring-type rustless steel counterweight M has centre bore, thereby they can slide on the plunger axis and stay on the axle collar.The gross weight of center plunger P, axle and rustless steel counterweight M be necessary for 596g (± 6g), this is corresponding to 0.30psi on the cylinder area.The center of round barrel cover O has opening and submarginal second opening that is used for fluid is introduced from storage tank cylinder Q that is used for perpendicular alignmnet plunger axis N.

Cylinder Q detailed specification is:

Outside diameter of cylinder: 70.35mm

Barrel bore: 60.0mm

Cylinder heights: 60.5mm

Round barrel cover O detailed specification is:

The external diameter of SFC lid: 76.05mm

The internal diameter of SFC lid: 70.5mm

Total external height of SFC lid: 12.7mm

The SFC lid does not contain the height of the axle collar: 6.35mm

Be positioned at the bore dia that is used for post sieve axle at center: 22.25mm

The bore dia of SFC lid: 12.7mm

The centre distance in above-mentioned two holes: 23.5mm

The detailed specification of metal counterweight M is:

Metal counterweight plunger axis diameter: 16.0mm

The diameter of metal counterweight: 50.0mm

The height of metal counterweight: 39.0mm

Fig. 3 has shown the detailed specification of plunger center P:

The diameter m:59.7mm at SFC plunger center

The height n:16.5mm at SFC plunger center

14 hole o of the diameter 9.65mm that spacing equates on 47.8mm bolt ring and

7 hole p of the diameter 9.65mm that spacing equates on 26.7mm bolt ring,

5/8 inch screw thread q.

Before using, the stainless steel mesh of reply SFC device accurately detects obstruction, hole or excessively stretches and replacement in case of necessity.SFC device with impaired screen cloth can produce incorrect SFC result and must all replace just use up to screen cloth.

(± 0.05cm) height is measured and with permanent precision marks labelling cylinder clearly being connected 5.00cm above the screen cloth of cylinder bottom.But need the fluid level of maintenance in this labeled analysis process.Correct and constant maintenance fluid level (hydrostatic pressure) is quite important to certainty of measurement.

Use constant hydrostatic head storage tank C that NaCl solution is delivered to cylinder, and the liquid level of solution is remained on be connected the height of the screen cloth top 5.0cm of cylinder bottom.Air intake pipe A is equipped with in the bottom of storage tank, fluid level maintains required 5.0cm height in the cylinder thereby make in measuring process, in the time of promptly on the mesh support screen on being placed on receiving vessel, the height of air hose A distance from bottom bench-top is identical with the height that is marked at apart from the bench-top of 5.0cm on the cylinder.Air intake pipe A is quite important to analyzing with the appropriate height correction that is marked at the 5.0cm fluid level on the cylinder.Suitable storage tank is made up of the bottle that contains as lower member: be used for the horizontal direction of conveyance fluid L-type carrier pipe E, storage tank at the open-ended vertical tube A that is used for air admission of level altitude, be used to recharge the hole B that clogs of storage tank.The carrier pipe E that is positioned near storage tank C bottom contains the piston F that is useful on the start/stop FLUID TRANSPORTATION.The outlet size of pipe makes it can insert round barrel cover O split shed, and its end is arranged in cylinder flow surface following (after reaching the 5cm height).Air intake pipe is positioned at o-annulate shaft ring.Storage tank can be positioned on the laboratory jack D, to regulate its height with respect to cylinder.The size of storage tank assembly makes that can fill cylinder fast keeps this height to desired height (being hydrostatic head) and during measuring.Storage tank must be able to be carried liquid at least 10 minutes under the minimum 3g/ flow velocity of second.

Plunger/cylinder unit is arranged on the ring, uprightly disposes the hard rustless steel mesh support screen (or device of equal value) of 16 meshes.This mesh support screen has enough permeabilitys, thereby can not hinder fluid flow, and have enough hardness to support rustless steel wire screen in case stretch.Mesh support screen should be smooth and level to avoid that cylinder unit is tilted.Fluid collection that will be by this mesh screen is in collecting storage tank, and it is positioned at mesh support screen below (but not supporting).To collect storage tank places and makes precision be at least 0.01g on the balance.The numeral output of balance is obtained system with computer data and is linked to each other.

The preparation of reagent

Below preparation is based on the volume of standard 1L.For the preparation that surpasses 1L, all compositions must calculate suitably.

The synthetic urine of Jayco

The deionized water of packing in the 1L volumetric flask is volumetrical 80% to it, adds stirring rod and also places on the agitator disk.Operational analysis balance and use weigh paper or beaker separately take by weighing (be accurate to ± 0.01g) amount of following dry ingredient and order same as described above add in the volumetric flask.Mixing is dissolved up to all solids, remove stirring rod then and with distilled water diluting to the 1L capacity.Add stirring rod again and more than mixed number on the agitator disk minute.The prepared solution conductivity is necessary for 7.6 ± 0.23mS/cm.

Anhydrous chemical formula [hydration]

Potassium chloride (KCl) 2.00g

Sodium sulfate (Na ₂SO ₄) 2.00g

Ammonium biphosphate (NH ₄H ₂PO ₄) 0.85g

Ammonium phosphate, two alkali formula ((NH ₄) ₂HPO ₄) 0.15g

Calcium chloride (CaCl ₂) 0.19g (2H ₂O) 0.25g

Magnesium chloride (MgCl ₂) 0.23g (6H ₂O) 0.50g

For making preparation quicker, before adding next composition, need to wait for and all dissolve until various salt.Jayco can store for 2 weeks in the cleaning glass container.If solution becomes muddiness then do not use.Be 10 days the storage life in the plastic containers of cleaning.

0.118M sodium chloride (NaCl) solution

Weigh paper or beaker of use (is accurate to the sodium chloride of 6.90g ± 0.01g) be weighed in the 1L volumetric flask and with deionized water and is filled to capacity.Add stirring rod and on agitator disk, mix and dissolve up to all solids.The electrical conductivity of prepared solution is necessary for 12.50 ± 0.38mS/cm.

The test preparation

Use reference metallic cylinder (diameter 40mm; Height 140mm) setting caliper (for example Mitotoyo Digimatic Height Gage) reading is zero.This operation is carried out on the bench-top of smooth and level usually.The SFC device that does not contain AGM is placed under the caliper and writes down thickness is L ₁, value is rounded up to 0.01mm.

Fill constant hydrostatic head storage tank with 0.118 M NaCl solution.Air intake pipe A is equipped with in the bottom of storage tank, thereby makes the top portion of liquid meniscus in the SFC cylinder maintain required 5.0cm height in measuring process.Air intake pipe A is crucial in alignment with the 5cm fluid level of labelling on the cylinder to analysis highly appropriately.

Add porous disc (the thickness 7mm that excessive synthetic urine makes 8cm by top at disk; Chemglass Inc.#CG 201-51 for example, coarse porosity) saturated.Repetition is saturated up to dish.Saturated porous disc is placed the suction dish, and add synthetic urine up to the level that reaches dish.Fluid level must be no more than the height of dish.

Place on the balance and the numeral output of balance is obtained system with computer data and be connected collecting storage tank.The ring that uprightly disposes the hard rustless steel mesh support screen of 16 meshes is placed the catch tray top.This 16 mesh screen cloth should have enough hardness to support the SFC device in measuring process.Mesh support screen must smooth and level.

The AGM sampling

The AGM sample should be stored in the air-tight bottle and maintain in the environment of constant, low humidity.Biased sample to epigranular distributes.Use scraper that the representative sample of material to be tested is taken out from the center of container.Recommend to use sample dispenser to increase the uniformity that sample granularity distributes.

The SFC program

Place the funnel of weighing on the analytical balance dish and balance is made zero.With scraper with 0.9g (± 0.05g) AGM is weighed in the funnel.The SFC cylinder is placed on the workbench, take out the funnel weigh and use the light finger tapping, transfer to AGM in the cylinder and guarantee that it is evenly distributed on the screen cloth.In the AGM transfer process, cylinder is rotated gradually so that disperse and obtain uniform distribution.The result who is distributed on the screen cloth obtaining pinpoint accuracy is important with making uniform particles.When distributing end, the AGM material is not sticked on the cylindrical wall.Plunger axis is inserted in the centre bore of lid, then the plunger center is inserted cylinder number centimetre.Plunger center and AGM are kept at a distance and insert lid in the cylinder, and it is carefully rotated up to the two aligning.It is aimed at covering the careful rotation of plunger, it is moved down and rest on the top of dry AGM.Insert the rustless steel counterweight in the thromboembolism bar and whether inspection cover moves freely.Suitably arrange lid to avoid constraint and to guarantee that weight is evenly distributed on the gel bed.

The thin screen cloth of cylinder bottom is easy to stretch.Stretch for anti-, on plunger rod, just be higher than the place of lid with forefinger and apply side pressure, catch the cylindrical portions may of device simultaneously.This with plunger " lock " thus leaning against cylinder interior can lift device.Whole device is placed on the porous disc of suction dish.Liquid level in the dish should be no more than the height of porous disc.Care should be used to makes layer not lose fluid or during this program in air.The fluid that can obtain in dish should be enough to all phases of swelling.Need, in hydro-combination process more in the multithread body adding dish, to guarantee to have enough available synthetic urine.After 60 minutes, the SFC device is placed under the caliper, and record thickness is L ₂, value is rounded up to 0.01mm.Pass through L ₂-L ₁The thickness of poor calculated for gel layer be L ₀, value is rounded up to ± 0.1mm.If reading changes in time, then only write down initial value.

The SFC device is moved on on the mesh support screen of catch tray top.When lift arrangement, the plunger lock must be leaned against cylinder interior.So that carrier pipe is placed constant hydrostatic head storage tank by the hole in the round barrel cover.Begin in the following order to measure:

A) open the piston of constant hydrostatic head storage tank and make fluid reach the 5cm labelling.Described fluid level should reach in 10 seconds of unlatching piston.

B) in case when reaching the fluid of 5cm, log-on data collection procedure immediately.

By the computer that links to each other with balance, by the Fluid Volume of gel layer, write down 10 minutes with respect to the time with 20 seconds interval records.After 10 minutes, close the piston of storage tank.The data that use was extremely tested when finishing from 60 seconds are calculated.The data of collecting before 60 seconds are not included in the calculating.Each AGM sample is repeated three tests.

It is the same with EP-A 640 330 that the evaluation of measuring keeps.Automatically collect output flow.

Following calculating saline water conservancy diversion rate (SFC):

SFC[cm ³s/g]＝(F _g(t＝0)×L ₀)/(d×A×WP)，

F wherein _g(t=0) be the F that measures from output flow _g(t) data are by the output flow (g/s) of the NaCl solution that is extrapolated to the t=0 linear regression analysis and obtains; L ₀Be gel layer thickness (cm); D is the density (g/cm of NaCl solution ³); A is the area (cm of gel layer ²); WP is the hydrostatic pressure (dyn/cm on the gel layer ²).

CS-SFC (core shell saline water conservancy diversion rate)

CS-SFC all fours SFC measures, but has following change:

For improving SFC, those skilled in the art can design the pipeline that infeeds that comprises piston, so that it is quite low to infeed the hydrodynamic drag of pipeline, make to keep constant in the Measuring Time that before the Measuring Time that really is used to estimate begins, obtains the fluid pressure identical and be used to estimate with SFC (5cm).

-used AGM weight be 1.50+/-0.05g

-use 0.9 weight % sodium chloride solution as making the preswollen solution of AGM sample and being used to measure output flow

-pre-the swelling time of sample that is used to measure is 240 minutes

-for pre-swelling, can with diameter the filter paper (Schleicher﹠amp of 90mm; Sch ü ll, No 597) place in the crystallizing pan (Schott, diameter=115mm, height 65mm) of 500ml, and add 250ml 0.9 weight % sodium chloride solution, the SFC measuring cell that will have sample then places on the filter paper and swelling 240 minutes

-per 5 seconds record output flow data write down 3 minutes altogether

-use measured some evaluation between 10 seconds and 180 seconds, and F _g(t=0) be the F that measures from output flow _g(t) data are by the output flow (g/s) of the NaCl solution that is extrapolated to the t=0 linear regression analysis and obtains

The raw material storage bottle that is used for output flow solution in the-SFC-measuring device contains about 5kg sodium chloride solution.

Particle size distribution

Particle size distribution is measured by the method for testing No.420.2-02 " particle size distribution " that EDANA (European Disposables and NonwovensAssociation) recommends.

16 hours extractables

The method of testing No.470.2-02 of the level that can extract composition in the water-absorbing polymeric particles by being recommended by EDANA (EuropeanDisposables and Nonwovens Association) " measure can extract polymer content by constant-current titration " measures.Extraction time is 16 hours.

PH value

The pH of water-absorbing polymeric particles " measures pH " by the method for testing No.400.2-02 that is recommended by EDANA (European Disposables andNonwovens Association) and measures.

Free swell speed (FSR)

With 1.00g (=W1) exsiccant water-absorbing polymeric particles is weighed in the glass beaker of 25mL and is evenly distributed on the bottom of glass beaker.Then 20mL 0.9 weight % sodium chloride solution is dispensed in second glass beaker, adds rapidly the content in this beaker in first beaker and start stopwatch.In case determine that by the areflexia on the liquid surface last saline solution is absorbed, and stops stopwatch.Accurately measure by weighing second beaker again by second beaker pour out and the exact amount of the liquid that absorbs by the polymer in first beaker (=W2).The absorption required time of measuring with stopwatch is designated as t.Last drop of liquid disappearance on the surface is defined as time t.

Following calculating free swell speed (FSR):

FSR[g/gs]＝W2/(W1×t)

Yet, when the moisture that forms base polymer surpasses 3 weight %, must be because of this moisture correcting weight W1.

The surface tension of aqueous extract

The 0.50g water-absorbing polymeric particles is weighed in the little glass beaker and with 40mL 0.9 weight % salt solution mix.The beaker content was stirred 3 minutes at the 500rpm lower magnetic force, placed then 2 minutes.At last, measure the surface tension of upper strata water with K10-ST numeral tensiometer or suitable equipment (available from Kruess) with platinum dish.Measurement is carried out under 23 ℃ temperature.

The moisture of base polymer

The water content of water-absorbing polymeric particles is measured by the method for testing No.430.2-02 " moisture " that is recommended by EDANA (European Disposablesand Nonwovens Association).

CIE chromatic number (Lab)

Carry out colour measurement according to CIELAB program (Hunterlab, the 8th volume, 1996, the 7 phases, 1-4 page or leaf).In the CIELAB system, via the coordinate L of three-dimensional system ^*, a ^*And b ^*Color is described.L ^*Expression brightness, L ^*=0 refers to black, L ^*=100 refer to white.a ^*And b ^*Value is represented the position of color on red/green and yellow/blue color axis respectively, wherein+and a ^*Expression is red ,-a ^*Expression is green ,+b ^*Expression yellow and-b ^*Expression is blue.

Three territory methods (three range method) according to DIN standard DIN 5033-6 are measured color.

Hunter 60 values are the tolerance of surperficial whiteness and are defined as L ^*-3b ^*, promptly the value of being somebody's turn to do is low more, and color is dark more and yellow more.

Use Hunterlab LS 5100 tintometers.

For example can be by European Disposables and Nonwovens Association, AvenueEugene Plasky 157, B-1030 Brussels, Belgium obtains the EDANA method of testing.The analytical method of coated polymer:

The preparation of elasticity film forming polymer film

In order to make elasticity film forming polymer used herein carry out following some method of testing (comprising wet-extension test), need obtain the film of this polymer.

Preferred average (as described below) thickness that is used for (doing) film of estimating at the method for testing of this paper is about 60 μ m.

The method for preparing film is known to those skilled in the art usually, generally includes solvent cast, heat fusing is extruded or the heat fusing blown film.Film by these method preparations may have the defined machine direction of direction that stretches or pull out as film.Be defined as horizontal direction with the vertical direction of machine direction.

For the purpose of the present invention, film used in the following method of testing is formed by solvent cast, during except that the solution that can't make any following solvent when the elasticity film forming polymer or dispersion, then extrudes the preparation film by heat fusing as described below.(latter is at room temperature attempting dissolving or dispersion after 2-48 hour when the granular materials of elasticity film forming polymer, material or apply agent and the mixture of solvent in when still seeing this polymer, or and situation can't film curtain coating time too high when the viscosity of solution or dispersion).

The gained film should have slick surface and not have visible defects such as bubble or crackle.

The example for preparing the solvent cast film of this paper by the elasticity film forming polymer:

The film of pending this paper test can as described belowly prepare by solution or dispersion curtain coating film by described material or coating agent:

Solution or dispersion prepare by the elasticity film forming polymer is dissolved in or is scattered in the water with 10 weight %, or if can not be then in THF (oxolane), or if can not be then in dimethyl formamide (DMF), or if can not be then in methyl ethyl ketone (MEK), or if can not be then in dichloromethane or if can not be then in toluene, or if can not be then in cyclohexane extraction (and if can not, then use heat fusing extrusion method hereinafter to form film).Then, dispersion or solution are poured in the polytetrafluoroethyldisk disk, and covered aluminium foil with the evaporation of slowing down, be higher than the polymer minimum film formation temperature, usually make the long-time slowly evaporation of solvent or dispersant under about 25 ℃ temperature, for example evaporation is at least 48 hours, or even up to 7 days.Then, film was placed 6 hours in 25 ℃ vacuum drying oven, to guarantee to remove any residual solvent.

It is as follows to form film method by aqueous dispersion:

Can use dispersion or dilute with water, as long as it is enough high to pull into film (200-500cps) to keep viscosity available from the supplier.Dispersion soln (5-10ml) is placed on a slice and the aluminium foil that drop-down desktop is connected.Use #30 or #60 Gardner gauge stick to draw polymeric dispersions, after drying, to obtain the film of 50-100 micron thickness.Make dispersant be higher than the minimum film-forming temperature of polymer, long-time slowly evaporation under about 25 ℃ usually temperature was for example evaporated 48 hours or even up to 7 days.Film was heated in 150 ℃ vacuum drying oven 5 minutes to 2 hours at the most at least, removed film from the paper tinsel base material in 5-10 minute by in tepidarium, soaking then, and remove film from this base material.Then, place the film that is removed on the teflon plate and under environmental condition dry 24 hours.Then with exsiccant film phonograph seal in plastic bag until testing.

Preparation this paper heat fusing extruded film method is as follows:

If can not use the solvent cast method, then the film of elasticity film forming polymer can be sufficiently high to allow the using single-screw extrusion equipment to be extruded by hot melt under the mobile temperature of elasticity film forming polymer herein.If the melting temperature of polymer is Tm, then extrude should surpass this Tm at least the temperature of 20K carry out.If polymer is amorphous (promptly not having Tm), then can carry out the steady state shearing viscosity method with measure polymer in order to disorder transformation, or the temperature that sharply descends of viscosity.The direction of being pulled out film by extruder is defined as machine direction, is defined as horizontal direction with the vertical direction of pull-out direction.

For example wettable tensile material mold temperature screw rod rpm

20 Irogran VP 654/5 180℃ 40

21 Elastollan LP 9109 170℃ 30

22 Estane 58245 180℃ 30

23 Estane 4988 180℃ 30

24 Pellethane 2103-70A 185℃ 30

The heat treatment of film:

For following method of testing, the heat treatment of film should be undertaken by film being placed than the vacuum drying oven under the temperature of the high about 20K of the highest Tg of used elasticity film forming polymer, and in vacuum drying oven, under less than 0.1 holder, carried out 2 hours, condition is when the elasticity film forming polymer has melt temperature Tm, heat treatment temperature is hanged down 20K at least than Tm, and preferred than the highest Tg height (as approaching) 20K.When reaching Tg, temperature should slowly rise to and be higher than this highest Tg, discharges to avoid gas, and gas is discharged can produce bubble in film.For example, hard section Tg is that 70 ℃ material can make temperature raise gradually, up to reaching heat treatment temperature 90 ℃ of following heat treatments 10 minutes then.

If the elasticity film forming polymer has Tm, then the described heat treatment of film (preparation as mentioned above, and the method test by hereinafter) is being higher than (the highest) Tg and is hanging down 20K at least than Tm and be higher than under the temperature of (the highest) Tg (as approaching) 20K and carry out.For example, Tm is that 135 ℃ and the highest Tg (hard section) are that 100 ℃ wettable tensile material can be at 115 ℃ of following heat treatments.

When not having detectable Tg or Tm, then the temperature that the heat treatment temperature in this method can be used with preparing the water absorbing material method is identical.

Can carry out, remove film,

If drying is difficult to from becoming film base material to remove with optional heat treated film, then it can be placed in tepidarium 30 seconds to 5 minutes, to remove film from base material.Then film was descended dry 6-24 hour at 25 ℃.

Wet extension test and the test of wet tensile stress:

This method of testing makes the required power of sample elongation by flat sample being applied uniaxial strain and measurement, and is used for the tensile property of the film of measurement fracture wet expansion (percentage elongation during=fracture) and elasticity film forming polymer used herein.

The preferred equipment that carries out this test is MTS Synergie100 or the MTS Alliance of stretching testing machine as being obtained by MTS Systems Corporation 14000 TechnologyDrive of U.S. MN Eden Prairie with 25N or 50N dynamometer.This has measured constant rate of extension, wherein stretching clamp move with uniform speed and the device of ergometry with putting forth effort to increase the almost negligible distance of mobile distance (less than 0.13mm).Select dynamometer so that the sensing lead of specimen (for example power) is the 10-90% of dynamometer ability.

Each sample uses the brill plate hydraulic pressure mould that film is cut into sample that film is cut into sample as mentioned above, and wherein each sample is 1 * 1 inch (2.5 * 2.5cm) (therefore, when preparing film by the method for not introducing any orientation, film can be tested in any direction).Select the sample (minimum three) of test to be substantially free of visual defects such as bubble, hole, inclusions and breach.They also must have sharp keen and not have the edge of defective substantially.

With low pressure caliper such as Mitutoyo Caliper Gauge, use the thickness of each drying sample of pressure measxurement of about 0.1psi to be accurate to 0.001mm.Three zoness of different of measuring samples, and definite average thickness.Use the dry weight of each sample of standard analysis balance measurement to be accurate to 0.001g and record.Drying sample is used for the mensuration of stem elongation rate, dried secant modulus and dried tensile stress values, and not preparation in addition.

For wet test, can under ambient temperature (23+/-2 ℃), preweighted desciccator diaphragm sample be soaked 24 hours in saline solution [0.9% (w/w) NaCl].Corrosion resistant metal screen cloth with 120 meshes is fixed on film in the bath, in case sample curls and self-adhesion.From bathe, take out film and use and absorb thin paper such as Bounty ^Napkin blots, to remove excessive or unabsorbed solution from the surface.Drying sample such as note are measured wet thickness.The sample that will wet is used to carry out extension test, and not preparation in addition.Test should finish to finish in back 5 minutes in preparation.Estimate wet sample to measure wet expansion, wet secant modulus and wet tensile stress.

For the purpose of the present invention, be stretched to fracture when fracture (or) and be called wet fracture when fracture (or) percentage elongation, and the tensile stress during fracture is called wet fracture strength.(during fracture, elongation at break % is a wet elongation at break used herein).

Extension test carries out on the stretching testing machine of the constant stretch speed with computer interface, as has the MTS Alliance stretching testing machine of Testworks 4 softwares.Select dynamometer so that the power of measuring drops between the 10-90% of dynamometer ability.Setting is equipped with smooth 1 "-the pneumatic type anchor clamps of square rubber-face anchor clamps, making and measuring length is 1 inch.Make the enough tension force of sample load, appreciable lax to eliminate, but less than 0.05N.Sample is with 10 "/minute the elongation of constant crosshead speed, rupture fully up to sample.If find sample in the seam fracture of anchor clamps or in anchor clamps, slide, forgo data then, and with new sample retest, and suitably adjust chucking pressure.Sample repetitive operation three times is to consider the variation of film.

Use initial sample size (obtaining percentage elongation used herein, tensile stress and modulus) that gained tensile force-displacement data is changed into load-deformation curve by it.The maximum stress that records when tensile stress at break is defined as sample breakage is also reported with MPa.Breakaway poing is defined as the stress of measuring on the load-deformation curve and drops on its peaked point at 90% o'clock.Elongation at break is defined as the strain of breakaway poing and reports with the percentage ratio with respect to initial measurement length.Secant modulus under 400% percentage elongation is defined as the straight slope that the load-deformation curve cross point constitutes when 0% and 400% strain.Estimate three load-deformation curves that each elastomer film coating produces.Percentage elongation used herein, tensile stress and modulus the average of each value that each curve obtains of all serving as reasons.

Dried secant modulus of elasticity (SM when 400% percentage elongation _{Dry 400%}) carry out above-mentioned identical extension test by making the desciccator diaphragm that obtains (but it is not immersed in the 0.9%NaCl solution) by said method, calculate the straight slope that the load-deformation curve with zero intercept and intersects then as mentioned above at 400% o'clock and calculate.

Glass transition temperature

For the purpose of the present invention, glass transition temperature (Tg) is measured by differential scanning calorimetry (DSC).Calorimeter should be able to be in the temperature range of the expection Tg that comprises sample to be tested, and as-90 ℃ to the 250 ℃ speed heating/coolings with at least 20 ℃/minutes, and the sensitivity of calorimeter should be about 0.2 μ W.TAInstruments Q1000 DSC is fit to measure the Tg of indication herein very much.Associated materials can use following temperature program(me) analysis :-90 ℃ of following balances, be warming up to 120 ℃ with 20 ℃/minute, kept isothermal 5 minutes, be cooled to-90 ℃ with 20 ℃/minute, kept isothermal 5 minutes, be warming up to 250 ℃ with 20 ℃/minute.Use the data (heat flow is with respect to temperature) of the heat cycles second time partly to extrapolate thermal capacity temperature algorithm and calculate Tg via standard.Usually, with the 3-5g specimen material (+/-0.1g) be weighed in the aluminum DSC dish with fold lid.

Tg used herein ₁Temperature less than Tg ₂

Polymer molecular weight

Can use chromatograph of gel permeation (GPC-MALS) to measure the molecular weight of the elasticity film forming polymer of this paper with polygonal light scattering monitor.The molecular weight of this paper is meant weight-average molar mass (Mw).Be fit to carry out these measuring systems and be made up of DAWN DSP laser photometer (Wyatt Technology), Optilab DSP interference refractometer (Wyatt Technology) and standard HPLC pump such as Waters 600E system, all devices are all operated via ASTRA software (Wyatt Technology).

All depend on particular polymers to be tested for any chromatographic isolation, solvent selection, post, temperature and elution curve and condition.Found that following condition is fit to elasticity film forming polymer as referred to herein usually: use oxolane (THF) as solvent and mobile phase; With 300 * 7.5mm, 5 μ ms, PLgel, the mixing-C GPC post (Polymer Labs) of 1ml/ minute flow velocity by two arranged in series, and be heated to 40-45 ℃ (the Optilab refractometer is remained under the uniform temp); The THF solution that injects 100 μ l0.2% polymer solutions is used for analyzing.The dn/dc value is obtained by obtainable document, or calculates with ASTRA.Weight-average molar mass (Mw) uses the Zimm fitting process by the ASTRA computed in software.

Vapor transmission rate method (MVTR method)

The MVTR method is measured the steam vapour amount that is transmitted by film under specified temp and humidity.The steam of transmission is by CaCl ₂Desiccant absorbs and gravimetry.With as over against the infiltrative reference membrane sample of setting up of photograph (for example Exxon Exxaire poromerics #XBF-110W) assess sample three times.

Flanged cup (being made by Delrin (McMaster-CarrCatalog#8572K34)) and anhydrous CaCl are used in this test ₂(Wako Pure Chemical Industries, Richmond, Va.; Catalog 030-00525).The height of cup is 55mm, and internal diameter is that 30mm and external diameter are 45mm.Be furnished with the polysiloxanes pad on the cup and contain 3 lids that are used for thumb screw with the hole of complete seal cup.Desiccant particle has by No. 8 screen clothes but can be by the size of No. 10 screen clothes.The membrane sample that does not have open defect of about 1.5 " * 2.5 " is used for analyzing.Film must cover the opening A of cup fully, and this opening is 0.0007065m ²

Use CaCl ₂Fill cup to the 1cm of top.On platform, rap this cup 10 times, make CaCl ₂Surface level.Regulate CaCl ₂Amount up to film surface and CaCl ₂Superjacent air space between the top is 1.0cm.Place the cup top across opening (30mm) film, and use polysiloxanes pad, retainer ring and thumb screw to fix.The appropriate installation, sample would not curl or stretch.With weigh sample assembly and being recorded to ± 0.001g of analytical balance.Assembly (was placed 5.0 hours ± 5 minutes in 75 ± 3%RH) the chamber in steady temperature (40 ± 3 ℃) and humidity.Take out the sample assembly, use Saran Wrap ^Cover and fix with rubber band.Make the sample balance to room temperature 30 minutes, remove plastic packets, the assembly and write down weight of weighing to ± 0.001g.The moisture M that absorbs _aFor initial and finally assembly weight poor.MVTR is with g/m ²/ 24 hours (g/m ²/ day) meter, following calculating:

MVTR=M _a/ (A ^*0.208 my god)

The reproducible results mean deviation is rounded off and correct to 100g/m ²/ 24 hours, 2865g/m for example ²/ 24 hours is 2900g/m at this paper ²/ 24 hours, 275g/m ²/ 24 hours is 300g/m at this paper ²/ 24 hours.

Measure the method for the water-soluble bloated ability of film forming polymer

With the weight record of polymer samples after soaking 3 days under the room temperature (25 ℃) in excessive deionized water is W ₁With exsiccant weight record before this polymer samples is W ₀The water-soluble bloated ability of following then calculating:

WSC[g/g]＝(W ₁-W ₀)/W ₀

The water uptake that water-soluble bloated ability is a polymer samples is in g water/1g dry polymer.For this method of testing, must prepare the polymer samples that is not thicker than 1.0mm usually for medium swollen polymer.May prepare the polymeric film of thickness for low swollen polymer, after 3 days, to obtain equilibrated swelling less than 0.5mm.The weight that those skilled in the art can regulate thickness and drying sample in the mode that obtained the equilibrium swelling situation after 3 days.

The centrifugal reserve capability of cylinder (4 hours CCRC)

The centrifugal reserve capability of cylinder (CCRC) method is measured water-swellable material or polymer (sample) centrifugal fluid reserve capability under the acceleration of 250g, and what this paper claimed is absorbability.Before centrifugal, make swelling in the excess salt aqueous solution of sample in having the hard sample cylinder of screen bottom and open top earlier.

Each test material is estimated the repeat samples sample and reported its meansigma methods.

CCRC can be at ambient temperature by with specimen material (1.0+/-0.001g) place in advance and weigh (+/--lucite shuttle 0.01g) is measured, and wherein this lucite shuttle open top and bottom are with making saline flow into cylinder easily but contain stainless steel mesh (400) sealing of being estimated absorbent granules.Sample cylinder is approximately the rectangular prism that height dimension is a 67mm tool rounded edges.Bottom size (OD 78 * 58mm, the jointer (being called the cylinder frame herein) of ID 67.2 * 47.2mm) and module pipe is coupling accurately, with this jointer centrifuge (Heraeus Megafuge 1.0 that packs into; Heraeus#75003491, rectangle rotating cylinder VWR#20300-016) (Heraeus#75002252, VWR#20300-084) in.

To the cylinder jolting gently of sample be housed,, vertically place the dish of salt-containing solution then so that sample is evenly distributed on the screen surface.Should guarantee that saline free-flow places cylinder in the end by sieve.Cylinder should not rely on mutually or lean against on the wall of dish or to the bottom sealing of dish.Make sample under the no confined pressure in excessive saline swelling 4 hours.

After 4 hours, from solution, take out cylinder immediately.Each cylinder is placed on (under the screen cloth side direction) cylinder frame, and the gained assembly is placed rotating cylinder, so that two sample assemblies are in the equilbrium position in centrifuge rotor.

Made sample centrifugal 3 minutes after making cylinder frame bottom produce the required speed of rotation of 250 ± 5g centrifugal acceleration reaching (± 10s).Opening in the cylinder frame can make any solution of displacing from absorbent by applying centrifugal force flow to the bottom of rotary barrel and stay wherein from sample.Sample cylinder is removed after rotation stops immediately, and weighing also, value is rounded up to 0.01g.

The centrifugal reserve capability of cylinder that the saline solution g numerical table that absorbs with every g specimen material shows is calculated each repetitive operation by following:

CCRC = \frac{m_{CS} - (m_{Cb} + m_{S})}{m_{S}} [\frac{g}{g}]

Wherein:

m _Cs: for having the cylinder quality [g] of sample after centrifugal

m _Cb: for not having the dryer cylinder quality [g] of sample

m _s: be the sample quality [g] that does not have saline solution

CCRC as referred to herein is the meansigma methods of repeat samples, and value is rounded up to 0.01g/g and reports.

Measure the method for the thickness of the shell that equates in theory of this paper water-swellable material

If known packets is contained in the film forming polymer amount in the water absorbing material, then can as described belowly determine average thickness of equal value in theory.This method water absorbing material be single disperse and the hypothesis of spherical (in fact really not so) under coating on the calculating water absorbing material herein or the average thickness of shell.Believe even under erose particulate situation, this method provides good estimation to the average thickness of shell.

Major parameter

The parameter of input	Symbol
The parameter of input	Symbol	Water absorbent polymer (AGM) applies the median granularity of quality (being also referred to as " average diameter ") before the film forming polymer	D_AGM_dry
The intrinsic density (this bulk phase, uncoated) of basis water absorbent polymer	Rho_AGM_intrinsic		D_AGM_dry
	Rho_AGM_intrinsic	The intrinsic density of elasticity film forming polymer (only coating or shell)	Rho_polymer_shell
Coating (shell) weight fraction (the film forming polymer coating accounts for the percent of the water absorbent polymer of whole coatings) of the water absorbent polymer that applies	c_shell_per_total		Rho_polymer_shell
	c_shell_per_total	Output parameter
If water absorbent polymer is single the dispersion and spheric film forming polymer coating average thickness	d_shell	Output parameter
	d_shell	The median granularity of quality of the water absorbent polymer that applies (" average diameter after applying ")	D_AGM_coated
Account for the coating weight ratio of uncoated water absorbent polymer percetage by weight as polymer coating	c_shell_to_bulk		D_AGM_coated

Formula

(note: the scope of all c that represent with percent is equivalent to 0-100% between 0-1 in this note)

d_shell : = \frac{D_AGM_dry}{2} \cdot [[1 + \frac{c_shell_per_total}{(1 - c_shell_per_total)} \cdot \frac{Rho_AGM_intrinsic}{Rho_polymer_shell}]^{\frac{1}{3}} - 1]

D_coated_AGM：＝D_AGM dry+2·d_shell

c_shell_to_bulk : = \frac{c_shell_per_total}{1 - c_shell_per_total}

Calculated examples

D_AGM_dry：＝0.4mm(400μm)；

Rho_AGM_intrinsic：＝Rho_polymer_shell：＝1.5g/cc

C_shell_per_total[％]	1	2	5	10	20	30	40	50
C_shell_per_total[％]	1	2	5	10	20	30	40	50	C_shell_to_bulk[％]	1.0	2.0	5.3	11	25	43	67	100
d_shell[μm]	0.7	1.4	3.4	7.1	15	25	37	52	C_shell_to_bulk[％]	1.0	2.0	5.3	11	25	43	67	100
d_shell[μm]	0.7	1.4	3.4	7.1	15	25	37	52	D_Coated_AGM[μm]	401	403	407	414	431	450	474	504

The embodiment of the invention:

Embodiment 1-applies ASAP 510 Z commercially available prod with Permax 120

From commercially available prod ASAP 510 Z (BASF AG), sift out 800-850 μ m fraction, apply Permax 120 then according to the present invention with following performance:

ASAP 510 Z (performance before the screening)

CCRC＝29.0g/g

AUL 0.7psi＝24.5g/g

SFC＝50×10 ^-7[cm ³s/g]

ASAP 510 Z (the only performance of 800-850 μ m fraction)

CS-CRC＝32.5g/g

CS-AUL 0.7psi＝26.4g/g

CS-SFC＝66×10 ^-7[cm ³s/g]

Use Wurster laboratory coating machine, absorbable polymer (ASAP 510 Z, this moment is for 800-850 μ m) consumption be 500 grams, the diameter of Wurster pipe is that 50mm and length are 150mm, gap width (with the distance of substrate) is 15mm, and the Wurster device is that base diameter is that 150mm expands the cone that top diameter is 300mm to, and used carrier gas is the nitrogen of 24 ℃ of temperature, gas flow rate in the Wurster pipe is 3.1m/s, and the gas flow rate of annular space is 0.5m/s on every side.

Use opening diameter as the nitrogen driving double nozzle of 1.2mm polymeric dispersions to be atomized, nitrogen temperature is 28 ℃.The 41 weight % pure water dispersions that by temperature are 24 ℃ are with the speed spraying Permax 120 65 minutes spraying 183g dispersions.In this process, 15 weight %Permax are put on the surface of absorbable polymer.The amount of being reported is based on used absorbable polymer.

Carry out twice operation again in identical mode, difference is that the level that applies of Permax is reduced to: 5.0 weight % and 10 weight %

The material that take out to apply then and it is uniformly distributed on the dish of teflonated (avoiding sintering together), and in vacuum drying oven 150 ℃ dry 2 hours down.(1000 μ m) removes piece by wide-meshed screen, and polymer characterization is as follows:

Load P ermax 120	CS-CRC[g/g]	CS-AUL 0.7psi[g/g]	CS-SFC[×10 ^-7cm ³s/g]
Load P ermax 120	CS-CRC[g/g]	CS-AUL 0.7psi[g/g]	CS-SFC[×10 ^-7cm ³s/g]	5 weight %	27.4	23.5	764
10 weight %	23.1	22.0	1994	5 weight %	27.4	23.5	764
10 weight %	23.1	22.0	1994	15 weight %	21.5	20.2	2027

Therefore, these polymer properties that so apply have far exceeded normal ranges.

Embodiment 2-applies ASAP 510 Z commercially available prod with Permax 200

From commercially available prod ASAP 510 Z (BASF AG), sift out 800-850 μ m fraction, apply Permax 200 then according to the present invention with following performance.

ASAP 510 Z (screening before performance) are as described in the embodiment 1.

Use as the Wurster laboratory coating machine among the embodiment 1, absorbable polymer (ASAP 510Z, this moment is for 800-850 μ m) consumption be 1000 grams, the diameter of Wurster pipe is that 50mm and length are 150mm, gap width (with the distance of substrate) is 15mm, the Wurster device is that base diameter is that 150mm expands the cone that top diameter is 300mm to, used carrier gas is the nitrogen of 24 ℃ of temperature, gas flow rate in the Wurster pipe is 2.0m/s, and the gas flow rate of annular space is 0.5m/s on every side.

Use opening diameter as the nitrogen driving double nozzle of 1.2mm polymeric dispersions to be atomized, nitrogen temperature is 27 ℃.The 22 weight % pure water dispersions that by temperature are 24 ℃ are with the speed spraying Permax 200 168 minutes spraying 455g dispersions.In this process, 10 weight %Permax are put on the surface of absorbable polymer.The amount of being reported is based on used absorbable polymer.

Carry out three operations again in identical mode, difference is that the level that applies of Permax is reduced to: 2.5 weight %, 5.0 weight % and 7.5 weight %.

Load P ermax200	CS-CRC[g/g]	CS-AUL 0.7psi [g/g]	CS-SFC [×10 ^-7cm ³s/g]
Load P ermax200	CS-CRC[g/g]	CS-AUL 0.7psi [g/g]	CS-SFC [×10 ^-7cm ³s/g]	2.5 weight %	29.7	24.7	234
5.0 weight %	27.5	25.3	755	2.5 weight %	29.7	24.7	234
5.0 weight %	27.5	25.3	755	7.5 weight %	25.6	23.8	1082
10.0 weight %	23.2	24.4	1451	7.5 weight %	25.6	23.8	1082

Embodiment 3-applies ASAP 510 Z commercially available prod with Permax 200

Use commercially available prod ASAP510 Z (BASF AG) with whole commercially available particle size distribution 150-850 μ m, apply Permax 200 then according to the present invention with following performance.

The performance of ASAP 510 Z is as described in the embodiment 1.

Use as the Wurster laboratory coating machine in embodiment 1 and 2, the consumption of absorbable polymer (being ASAP 510 Z this moment) is 1000 grams, the diameter of Wurster pipe is that 50mm and length are 150mm, gap width (with the distance of substrate) is 15mm, the Wurster device is that base diameter is that 150mm expands the cone that top diameter is 300mm to, used carrier gas is the nitrogen of 24 ℃ of temperature, gas flow rate in the Wurster pipe is 1.0m/s, and the gas flow rate of annular space is 0.26-0.30m/s on every side.

Use opening diameter as the nitrogen driving double nozzle of 1.2mm polymeric dispersions to be atomized, nitrogen temperature is 25 ℃.The 22 weight % pure water dispersions that by temperature are 24 ℃ are with the speed spraying Permax 200 221 minutes spraying 455g dispersions.In this process, 10 weight %Permax are put on the surface of absorbable polymer.The amount of being reported is based on used absorbable polymer.

The material that take out to apply then and it is uniformly distributed on the dish of teflonated (avoiding sintering together), and in vacuum drying oven 150 ℃ dry 2 hours down.(850 μ m) removes piece by wide-meshed screen, and polymer characterization is as follows:

Load P ermax 200	CS-CRC[g/g]	CS-AUL 0.7psi [g/g]	CS-SFC [×10 ^-7cm ³s/g]
Load P ermax 200	CS-CRC[g/g]	CS-AUL 0.7psi [g/g]	CS-SFC [×10 ^-7cm ³s/g]	2.5 weight %	25.5	22.2	279
5.0 weight %	24.1	25.1	735	2.5 weight %	25.5	22.2	279
5.0 weight %	24.1	25.1	735	7.5 weight %	23.1	22.3	930
10.0 weight %	21.7	25.4	1303	7.5 weight %	23.1	22.3	930

Embodiment 4: use disaggregation auxiliary agent (calcium phosphate) before heat treatment

Repeat the operation of embodiment 2 with 10%Permax 200, yet will transfer in the laboratory cylinder mixer with the polymer that dispersion applies, and based on polymer add 1.0 weight % tricalcium phosphate type C13-09 (available from Budenheim, Mainz) and with apply polymer dry mixed and about 10 minutes.Subsequently polymer is transferred in the laboratory fluidized bed dryer (the about 70mm of diameter) that is preheating to 150 ℃, after 30 minutes the time of staying, records following performance:

CS-CRC＝22.2g/g

CS-AAP＝22.3g/g

CS-SFC＝1483×10 ^-7[cm ³s/g]

In heat treatment process in fluid bed without any caking, so fluid bed still keeps highly stable and as the screening by 1000 μ m screen clothes subsequently prove.

The compare operation that does not add the disaggregation auxiliary agent causes the fluid bed disintegrate and does not obtain any useful product.

Embodiment 5: use disaggregation auxiliary agent (Aerosil 90) before the heat treatment

Repeat the operation of embodiment 2 with 10%Permax 200, yet will transfer in the laboratory cylinder mixer with the polymer that dispersion applies, and based on polymer add 1.0 weight %Aerosil 90 (available from Degussa) and with apply polymer dry mixed and about 10 minutes.Subsequently with in the opening glass that is placed on diameter 5cm and high 3cm of polymer with 1.5-2.0cm, and in the forced-air circulation drying oven 150 ℃ of following heat treatments 120 minutes.Polymer still can be mobile fully, and any caking or gathering do not take place.

Record following performance:

CS-CRC＝23.6g/g

CS-AAP＝23.4g/g

CS-SFC＝1677×10 ^-7[cm ³s/g]

Embodiment 6:

Repeat the operation of embodiment 5.Yet, do not add the disaggregation auxiliary agent, but in cylinder mixer homogenize 10 minutes.Polymer beads is dispersed in loose individual particle layer on the dish of teflonated and in forcing air drying cabinet and handled 120 minutes down at 150 ℃.

Record following performance:

CS-CRC＝23.5g/g

CS-AAP＝21.6g/g

CS-SFC＝1889×10 ^-7[cm ³s/g]

Also unsuccessful as contrast operation's (not adding the disaggregation auxiliary agent) that embodiment 5 carries out with heat treatment in glass.Product forms piece and becomes useless.

Embodiment 7:

Use with embodiment 1 in identical Wurster laboratory coating machine, absorbable polymer (ASAP510Z, this moment is for 800-850 μ m fraction) consumption be 1000 grams, the diameter of Wurster pipe is that 50mm and length are 150mm, gap width (with the distance of substrate) is 15mm, the Wurster device is that base diameter is that 150mm expands the cone that top diameter is 300mm to, used carrier gas is the nitrogen of 22 ℃ of temperature, gas flow rate in the Wurster pipe is 2.0m/s, and the gas flow rate of annular space is 0.5m/s on every side.

Estane X-1007-040P is dissolved in the solution that obtains 5 weight % in the oxolane.Use opening diameter as the nitrogen driving double nozzle of 1.2mm polymer solution to be atomized, the temperature of nitrogen and solution is 22 ℃.Solution is with the speed spraying at 106 minutes spraying 586g solution.In this process, 2.9 weight %Estane X-1007-040P are put on the surface of absorbable polymer.The amount of the film forming polymer Estane X-1007-040P that is reported is based on used absorbable polymer.

Load EstaneX-1007-040P	CS-CRC [g/g]	CS-AUL 0.7 psi[g/g]	CS-SFC [×10 ^-7cm ³s/g]
Load EstaneX-1007-040P	CS-CRC [g/g]	CS-AUL 0.7 psi[g/g]	CS-SFC [×10 ^-7cm ³s/g]	2.9 weight %	25.7	18.4	443

Embodiment 8:

Use with embodiment 1 in identical Wurster laboratory coating machine, the consumption of absorbable polymer (ASAP510Z, 800-850 μ m) is 1000 grams, does not use Wurster to manage in this embodiment.Used carrier gas is the nitrogen of 22 ℃ of temperature, and gas flow rate is 1.09-1.26m/s.

Estane X-1007-040P is dissolved in the solution that obtains 5 weight % in the oxolane.Use opening diameter as the nitrogen driving double nozzle of 1.2mm polymer solution to be atomized, the temperature of nitrogen and solution is 23 ℃.Solution is with the speed spraying at 72 minutes spraying 500g solution.In this process, 2.5 weight %Estane X-1007-040P are put on the surface of absorbable polymer.The amount of the film forming polymer Estane X-1007-040P that is reported is based on used absorbable polymer.

Load EstaneX-1007-040P	CS-CRC [g/g]	CS-AUL 0.7psi [g/g]	CS-SFC [×10 ^-7cm ³s/g]
Load EstaneX-1007-040P	CS-CRC [g/g]	CS-AUL 0.7psi [g/g]	CS-SFC [×10 ^-7cm ³s/g]	2.5 weight %	21.1	17.9	943

Embodiment 9:

Use whole fraction 150-850 μ m of ASAP 510 Z to repeat embodiment 3, Permax is added with the amount of being given in the table by the aqueous dispersion of following each concentration as absorbable polymer.The material that take out to apply then and it is uniformly distributed on the dish of teflonated (avoiding sintering together), and in vacuum drying oven 150 ℃ dry 2 hours down.(1000 μ m) removes piece by wide-meshed screen, and the sign of polymer is as follows:

Load P ermax 200	The content of Permax in the spraying dispersion	CS-CRC [g/g]	CS-AUL 0.7psi [g/g]	CS-SFC [×10 ^-7cm ³s/g]
Load P ermax 200	The content of Permax in the spraying dispersion	CS-CRC [g/g]	CS-AUL 0.7psi [g/g]	CS-SFC [×10 ^-7cm ³s/g]	1.0 weight %	22 weight %	28.4	24.4	161
2.5 weight %	22 weight %	27.0	24.3	285	1.0 weight %	22 weight %	28.4	24.4	161
2.5 weight %	22 weight %	27.0	24.3	285	2.5 weight %	11 weight %	26.7	24.4	399

Also with standard method of test these samples are characterized, the result is as follows:

Load P ermax200	The content of Permax in the spraying dispersion	CRC [g/g]	AUL 0.7psi [g/g]	SFC [×10 ^-7cm ³s/g]
Load P ermax200	The content of Permax in the spraying dispersion	CRC [g/g]	AUL 0.7psi [g/g]	SFC [×10 ^-7cm ³s/g]	1.0 weight %	22 weight %	27.8	21.9	187
2.5 weight %	22 weight %	25.5	22.2	244	1.0 weight %	22 weight %	27.8	21.9	187
2.5 weight %	22 weight %	25.5	22.2	244	2.5 weight %	11 weight %	24.8	22.1	337

Non-Comparative Examples of the present invention:

Comparative Examples 1-base polymer

The 1326kg solid content of packing in operational capacity is 2 tonnes double-arm half commercialization kneader is the neutral sodium acrylate aqueous solution of part of 36 weight %.Solid content is meant based on the acrylic acid of total overall reaction solution and the summation of sodium acrylate herein.Degree of neutralization is 69 moles of %.Add the 18 heavily trimethylolpropane triacrylate cross-linking agent and the fully mixing of ethoxylation of 0.40 weight % (based on acrylic monomers), make this batch of material deactivation with nitrogen subsequently.The temperature of this solution is 19 ℃.

By under agitation adding sodium peroxydisulfate (1.27kg fast, be dissolved in the 7.2kg water) and ascorbic acid (18.6kg, be dissolved in the 3.7kg water) and initiated polymerization, continue violent the kneading then, and, produced the gel that does not contain piece in small, broken bits so that the mode that the maximum temperature of kneader maintains below 100 ℃ was cooled off the wall of reactor 45 minutes.

Described gel is dry on band drier, on the drum-type grinder, grind then, after sift out the fraction of 150-850 μ m.The performance of resulting polymers powder is as follows:

CRC＝34.2g/g

AUL 0.3psi＝12.4g/g

16 hours extractable=12 weight %

Residual acrylic acid monomer=220ppm

pH＝5.9

Particle size distribution

＞850 μ m＜0.1 weight %

710-850 μ m 8.0 weight %

600-710 μ m 16.1 weight %

500-600 μ m 17.9 weight %

400-500 μ m 15.0 weight %

300-400 μ m 17.0 weight %

250-300 μ m 8.8 weight %

200-250 μ m 8.5 weight %

150-200 μ m 8.1 weight %

106-150 μ m 0.6 weight %

＜106 μ m＜0.1 weight %

Comparative example 2-base polymer

Repeat Comparative Examples 1 preparation base polymer.

Described polymer is dry on band drier, on the drum-type grinder, grind then, after sift out the fraction of 150-600 μ m.The performance of resulting polymers powder is as follows:

CRC＝34.6g/g

AUL 0.3psi＝11.2g/g

16 hours extractable=12 weight %

Residual acrylic acid monomer=240ppm

pH＝5.9

Particle size distribution

＞850 μ m 0.0 weight %

710-850 μ m 0.0 weight %

600-710 μ m 0.5 weight %

500-600 μ m 18.2 weight %

400-500 μ m 38.5 weight %

300-400 μ m 14.5 weight %

250-300 μ m 15.6 weight %

200-250 μ m 11.5 weight %

150-200 μ m 1.2 weight %

106-150 μ m＜0.1 weight %

＜106 μ m 0.0 weight %

Comparative example 3-base polymer

The base polymer of promptly making of Comparative Examples is sieved once with the fine powder that gets on by the screen cloth at 200 μ m.The performance of resulting polymers powder is as follows:

CRC＝34.7g/g

AUL 0.3psi＝14.1g/g

16 hours extractable=12 weight %

pH＝5.9

Particle size distribution

＞850 μ m＜0.1 weight %

710-850 μ m 4.0 weight %

600-710 μ m 20.1 weight %

500-600 μ m 22.9 weight %

400-500 μ m 21.1 weight %

300-400 μ m 19.9 weight %

250-300 μ m 6.7 weight %

200-250 μ m 5.2 weight %

150-200 μ m 0.5 weight %

106-150 μ m＜0.1 weight %

＜106 μ m＜0.1 weight %

Comparative Examples 4:

The base polymer of the 1.2kg Comparative Examples 1 of in capacity is the L  dige VT 5R-MK colter formula kneader of 5L, packing into.Prepared back cross-linking agent mixture, and the double nozzle that under agitation drives with nitrogen sparges it on base polymer with following composition.With regard to mixture, all amounts of being reported are the weight % based on initial base polymer of packing into.

0.10 weight %2- oxazolidone

0.10 weight %1, the 2-propylene glycol

0.10 weight %1, ammediol

0.50 weight % calcium phosphate (Rhodia TCP 118)

0.20 weight %7-is the trimethylolpropane of ethoxylation (Perstorp Polyol TP70) heavily

0.62 weight % isopropyl alcohol

2.38 weight % does not have ionic water fully

Calcium phosphate is scattered in this mixture.

After with back cross-linking agent mixture spraying, stir product, simultaneously by adding hot fluid reactor heating shell, heat product property favourable fast.So that product reaches 185 ℃ target temperature as far as possible apace, heat treated mode is controlled adding thermal compensation under steady-state conditions and stirring then.The same nitrogen wash reactor of using.Shifted out product in back 40 minutes beginning to heat then, it is cooled to room temperature and measures performance.These performances are listed in table 1.

Comparative Examples 5:

Repeat Comparative Examples 4, difference only is to shift out product in back 50 minutes beginning to heat, and is cooled to room temperature subsequently and measures performance.These performances are listed in table 1.

Comparative Examples 6:

In pilot-plant, with the base polymer of back, surface cross-linking agent mixture spraying Comparative Examples 2, subsequently to its heat treatment.

Be sprayed at Schuggi ^Carry out in-Flexomix type 100 D the blenders, and infeed base polymer and be metered into the liquid of continuous mass current control via double nozzle by gravity.

Prepared back cross-linking agent mixture with following composition, and with its double nozzle spraying by driving with nitrogen.With regard to mixture, all amounts of being reported are the weight % based on initial base polymer of packing into.

0.12 weight %2- oxazolidone

0.12 weight %1, the 2-propylene glycol

0.10 weight %1, ammediol

0.70 weight % calcium phosphate (Rhodia TCP 118)

0.40 weight %7 is the trimethylolpropane of ethoxylation (Perstorp Polyol TP70) heavily

0.33 weight % isopropyl alcohol

2.23 weight % does not have ionic water fully

Calcium phosphate is scattered in this mixture.

Wet polymer is directly fallen to being transferred in the NARA NPD 1.6 W reaction equation exsiccators (available from the Gouda of Holland) from the Schuggi blender.The output speed of base polymer is 60kg/ hour (drying), and the product temperature at the dryer export place of steam heated exsiccator is about 192 ℃.The cooler in exsiccator downstream makes product be quickly cooled to about 50 ℃.Via output speed and height of weir degree (herein be 70%) and the accurately definite time of staying of predetermined exsiccator of polymer by exsiccator.Product is sieved to remove aggregation by 850 μ m screen clothes.

The performance of product is listed in the table 1.

Comparative Examples 7:

Comparative Examples 7 is quite analogous to Comparative Examples 6 and is prepared and constitutes reproduction.Product property is listed in the table 1.

Comparative Examples 8:

In pilot-plant, with the base polymer of back, surface cross-linking agent mixture spraying Comparative Examples 3, subsequently to its heat treatment.

0.10 weight %2- oxazolidone

0.10 weight %1, the 2-propylene glycol

0.10 weight %1, ammediol

0.50 weight % calcium phosphate (Rhodia TCP 118)

0.20 weight %7 is the trimethylolpropane of ethoxylation (Perstorp Polyol TP70) heavily

0.62 weight % isopropyl alcohol

2.38 weight % does not have ionic water fully

Calcium phosphate is scattered in this mixture.

Wet polymer is directly fallen to being transferred in the NARA NPD 1.6 W reaction equation exsiccators (available from the Gouda of Holland) from the Schuggi blender.The output speed of base polymer is 60kg/ hour (drying), and the product temperature at the dryer export place of steam heated exsiccator is about 182 ℃.The cooler in exsiccator downstream makes product be quickly cooled to about 50 ℃.Via output speed and height of weir degree (herein be 70%) and the accurately definite time of staying of predetermined exsiccator of polymer by exsiccator.Product is sieved to remove aggregation by 850 μ m screen clothes.

The performance of product is listed in the table 1.

Comparative Examples 9:

Comparative Examples 9 is quite analogous to Comparative Examples 8 and is prepared, and difference is that the temperature at dryer export place only is about 179 ℃.Product property is listed in the table 1.

Table 1

Comparative Examples	CRC[g/g]	SFC[×10 ^-7cm ³s/g]	CS-CRC[g/g]	CS-SFC[×10 ^-7cm ³s/g]	AUL 0.7psi[g/g]	CS-AUL0.7psi[g/g]
Comparative Examples	CRC[g/g]	SFC[×10 ^-7cm ³s/g]	CS-CRC[g/g]	CS-SFC[×10 ^-7cm ³s/g]	AUL 0.7psi[g/g]	CS-AUL0.7psi[g/g]	4	30.0	97	27.0	80	24.0	23.0
5	27.8	157	25.6	94	23.2	22.9	4	30.0	97	27.0	80	24.0	23.0
5	27.8	157	25.6	94	23.2	22.9	6	26.6	96	24.6	68	24.2	24.9
7	26.0	108	25.0	65	24.0	25.5	6	26.6	96	24.6	68	24.2	24.9
7	26.0	108	25.0	65	24.0	25.5	8	29.6	58	29.1	36	25.6	27.2
9	29.7	48	28.8	28	25.5	27.0	8	29.6	58	29.1	36	25.6	27.2

It can be seen from the table the neither one Comparative Examples can obtain the ratio to CS-SFC with the approaching similar CS-CRC of the embodiment of the invention.

Claims

1. water absorbing material that can obtain by the method that comprises the steps:

B) granule that heat treatment applies under the temperature more than 50 ℃.

2. water absorbing material that can obtain by the method that comprises the steps:

B) granule that heat treatment applies under the temperature more than 50 ℃.

3. according to the water absorbing material of claim 1 or 2, the centrifugal reserve capability of its SMIS shell (CS-CRC) is not less than 20g/g.

4. according to each water absorbing material among the claim 1-3, wherein CS-CRC and CS-SFC (core shell saline flow conductivity) satisfy with lower inequality: Log (CS-SFC '/150)＞2.5-0.095 * CS-CRC, wherein CS-SFC '=CS-SFC * 10 ⁷And 150 dimension is [cm ³S/g].

5. according to each water absorbing material among the claim 1-4, wherein with crosslinked behind the described water-absorbing polymeric particles.

6. according to each water absorbing material among the claim 1-5, wherein said elasticity film forming polymer is a polyurethane.

7. according to each water absorbing material among the claim 1-6, wherein said elasticity film forming polymer is an EU.

8. according to the water absorbing material of claim 7, the content of the aklylene glycol unit of wherein said EU in side chain is 10-90 weight % based on the gross weight of EU.

9. water absorbing material according to Claim 8, wherein based on the gross weight of EU, the content of ethylene oxide unit in the side chain of described EU is not less than 12 weight % and the content of ethylene oxide unit in the main chain of described EU is no more than 30 weight %.

10. according to the water absorbing material of claim 7, wherein the content of oxyalkylene units in described EU is no more than 90 weight % based on the gross weight of EU.

11. according to each water absorbing material among the claim 1-10, it can obtain by applying 0.1-25 weight portion elasticity film forming polymer (calculating with solid-state material) to the dry water-absorbing polymeric particles of 100 weight portions.

12. according to each water absorbing material among the claim 1-11, its can by apply to the dry water-absorbing polymeric particles of 100 weight portions＜5 weight portion elasticity film forming polymers (calculating with solid-state material) obtain.

13. according to each water absorbing material among the claim 1-12, it can be by obtaining with the continuity method spray application in fluidized-bed reactor.

14. according to each water absorbing material among the claim 1-13, it can be by obtaining with elasticity film forming polymer spray application water-absorbing polymeric particles under less than 45 ℃ temperature at 0 ℃.

15. according to each water absorbing material among the claim 1-14, it can obtain by the aqueous dispersion spray application water-absorbing polymeric particles with the elasticity film forming polymer.

16. according to the water absorbing material of claim 15, the viscosity of wherein said aqueous polymer dispersion is 500mPas.

17., wherein in Wurster coating machine or Glatt-Zeller coating machine, or in the continuous fluid bed bioreactor or in the continuous spouted bed bioreactor, apply according to each water absorbing material among the claim 1-16.

18., wherein select the air-flow in the Wurster coating machine, so that the relative humidity of air flow outlet is 10-90% according to each water absorbing material among the claim 1-17.

19. according to each water absorbing material among the claim 1-18, it can obtain by heat treatment in fluid bed.

20., wherein before described heat treatment, add the disaggregation auxiliary agent according to each water absorbing material among the claim 1-19.

21. according to each water absorbing material among the claim 1-20, wherein said heat treatment carries out under 100-200 ℃ temperature.

22. according to each water absorbing material among the claim 1-21, wherein said heat treatment and suitable words are coated in the noble gas carries out.

23. according to each the water absorbing material that can obtain among the claim 1-22 by the method that comprises the steps:

A) under 0-50 ℃ temperature in fluidized-bed reactor with elasticity film forming polymer spray application water-absorbing polymeric particles and

D) heat treated granule is cooled to below 90 ℃.

24. according to each water absorbing material among the claim 1-23, wherein CS-CRC and CS-SFC (core shell saline flow conductivity) satisfy with lower inequality: Log (CS-SFC '/150)＞3.36-0.133 * CS-CRC, wherein CS-SFC '=CS-SFC * 10 ⁷And 150 dimension is [cm ³S/g].

25. a method of producing according to the water absorbing material of claim 1 comprises the steps:

B) granule that heat treatment applies under the temperature more than 50 ℃.

26., wherein use the aqueous dispersion spray application water-absorbing polymeric particles of film forming polymer according to the method for claim 25.

27. according to the method for claim 26, the viscosity of wherein said aqueous polymer dispersion is 500mPas.

28., wherein in Wurster coating machine or Glatt-Zeller coating machine, or in the continuous fluid bed bioreactor or in the continuous spouted bed bioreactor, apply according to each method among the claim 25-27.

29., wherein select fluidized-bed reactor so that the relative humidity of air flow outlet is 10-90% according to the method for claim 28.

30. according to each method among the claim 25-29, wherein said heat treatment carries out in continuous fluidized bed.

31., wherein before described heat treatment, add the disaggregation auxiliary agent according to each method among the claim 25-30.

32. according to each method among the claim 25-31, wherein said heat treatment carries out under 100-200 ℃ temperature.

33. according to each method among the claim 25-32, wherein said heat treatment and suitable words are coated in the noble gas carries out.

34. the water absorbing material that comprises water-absorbing polymeric particles with elasticity film forming polyurethane-coated, wherein said polyurethane not only comprise the side chain with polyoxyethylene units but also have the polyoxyalkylene unit on main chains.

35. according to the water absorbing material of claim 34, the centrifugal reserve capability of core shell (CS-CRC) of wherein said water-absorbing polymeric particles is not less than 20g/g.

36. according to the water absorbing material of claim 34 or 35, wherein CS-CRC and CS-SFC satisfy with lower inequality: Log (CS-SFC '/150)＞2.5-0.095 * CS-CRC, wherein CS-SFC '=CS-SFC * 10 ⁷And 150 dimension is [cm ³S/g].

37. according to each water absorbing material among the claim 34-36, wherein with crosslinked behind the described water-absorbing polymeric particles.

38. water absorbing material that can obtain by the method that comprises the steps:

A) in fluidized-bed reactor with continuity method with elasticity film forming polymer spray application water-absorbing polymeric particles and

B) granule that heat treatment applies under the temperature more than 50 ℃.

39. a method of producing according to the water absorbing material of claim 38 comprises the steps:

B) granule that heat treatment applies under the temperature more than 50 ℃.