CN1697690A - Particulate water absorbent containing water absorbent resin as a main component - Google Patents

Particulate water absorbent containing water absorbent resin as a main component Download PDF

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CN1697690A
CN1697690A CN 200480000104 CN200480000104A CN1697690A CN 1697690 A CN1697690 A CN 1697690A CN 200480000104 CN200480000104 CN 200480000104 CN 200480000104 A CN200480000104 A CN 200480000104A CN 1697690 A CN1697690 A CN 1697690A
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water
water absorbent
absorbent containing
particulate water
absorbing resin
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CN100482339C (en
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足立芳史
北野贵洋
藤丸洋圭
池内博之
和田克之
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Nippon Shokubai Co Ltd
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Nippon Shokubai Co Ltd
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Abstract

PROBLEM TO BE SOLVED: To provide a particulate water absorbent showing excellent absorption ability for liquid such as urine and a sanitary material using the same.

Description

With the water-absorbing resin is the particulate water absorbent containing of main component
Technical field
The present invention relates to the water-absorbing resin is the particulate water absorbent containing of main component, more specifically says, relates to the particulate water absorbent containing that the liquid such as urine sample is had the good absorption ability.
Technical background
Recently, water-absorbing resin has been widely used as the composition of sanitary product, as paper nappy, sanitary napkin, and gatism with pad, with absorbed body fluid.The example of this water-absorbing resin comprises: the polyacrylic acid crosslinked polymkeric substance of part neutral; Starch and acrylic acid hydrolysis graftomer; The saponified copolymer of vinyl acetate resin and acrylate; The hydrolyzed copolymer of vinyl cyanide or acrylamide, or it is crosslinked; And the cross-linked polymer of cationic monomer.
Such water-absorbing resin requires to have good performance, is included in the ability of rapid absorption q.s liquid when sweat fluid as body fluid contacts.The performance of other requirement comprises gel-strength, and the gel infiltration rate reaches the ability that absorbs liquid from the starting material that contain aqueous fluid.In addition, narrow to size-grade distribution in recent years, or have the water-absorbent resin powder of high-absorbility and low water-soluble content that the requirement that grows with each passing day is arranged.This water-absorbent resin powder also must have under pressure high Test Liquid Permeability of Core is arranged under high specific absorption and the pressure.
For example, following document 1-24 discloses performance perameter and the measuring method that this water-absorbing resin is stipulated.
Specifically, document 1 (U.S. is issued patents 32,649 again) proposes a kind of water-absorbing resin, and it is outstanding aspect jelly grade, solubilized amount and receptivity.(English Patent 2,267 094B) proposes a kind of water-absorbing resin to document 2, and its Test Liquid Permeability of Core under no pressure is good, and excellent absorption rate and receptivity are arranged.In addition, document 3 (United States Patent (USP) 5,051,259) document 4 (United States Patent (USP) 5,419,956), document 5 (United States Patent (USP) 6,087,002), and document 6 (European patent 629,441) has proposed to draft the technology of size-grade distribution.
In addition, multiple have the water-absorbing resin of superior absorption capacity and measuring method thereof also to propose under various pressure.For example, proposed some water-absorbing resins, its performance or include only water-retaining capacity under the pressure perhaps also comprises other performance, be disclosed in the following document, as document 7 (European patent 707,603), document 8 (European patent 712,659), document 9 (European patent 1,029,886), document 10 (United States Patent (USP) 5,462,972), document 11 (United States Patent (USP) 5,453,323), document 12 (United States Patent (USP) 5,797,893), document 13 (United States Patent (USP) 6,127,454), document 14 (United States Patent (USP) 6,184,433), document 15 (United States Patent (USP) 6,297,335), reach document 16 (U.S. is issued patents Re37 again, 021).
In addition, the water-absorbing resin with excellent in resistance impact (representing with performance degradation) is also reported, see document 17 (United States Patent (USP) 5,140,076) and document 18 (United States Patent (USP) 6,414,214B1).
In addition, the water-absorbing resin of regulation amount of dust for example proposes in document 19 (United States Patent (USP) 5,994,440), and painted hardly water-absorbing resin for example proposes in document 20 (United States Patent (USP) 6,444,744).As for anti-urine corrodibility, document 21 (United States Patent (USP) 6,194,531) and document 22 (European patent 940,148) proposed to have excellent gel stability and with respect to water-absorbing resin such as the receptivity of the such liquid of L-aqueous ascorbic acid, and document 23 (European patent 1,153,656) discloses a kind of water-absorbing resin that good ventilation property is arranged.In addition, propose to contain hardly the water-absorbing resin of residual monomer at document 24 (European patent 605,215).
It is reported have the water-absorbing resin of specified property also to be applicable to have special performance, shape, and/or the absorbate of density polymer (diaper), see document 25 (United States Patent (USP) 5,147,343), document 26 (United States Patent (USP) 5,149,335), document 27 (European patent 532,002), document 28 (United States Patent (USP) 5,601,452), document 29 (United States Patent (USP) 5,562,646), document 30 (United States Patent (USP) 5,669,894), document 31 (United States Patent (USP) 6,150,582), document 32 (international publication WO02/53198), document 33 (United States Patent (USP) 5,843,059), reaches document 34 (Application No. 2001/4951).
Therefore some water-absorbing resins have been developed in view of these different performances, wherein some is produced and uses at this performance and the water-absorbing resin that possesses this performance, but still have problem, promptly enable control characteristic, water-absorbing resin still can not fully provide this specific character in practical application (as paper nappy).In detail, when water-absorbing resin is applied to sanitary product, wherein contain a large amount of water-absorbing resins and small amount of fibers material (water-absorbing resin ratio height), its performance is still good inadequately.
Disclosure of an invention
The present invention proposes in view of traditional water-absorbing resin, be to have considered various performances and develop (absorption rate, there is not the receptivity of pressing under (no-load), the receptivity under the pressure (load), gel-strength, durability, solvable amount, granularity etc.), the objective of the invention is to solve traditional problem, the adjustment and the design that are these performances can not produce the satisfied water-absorbing resin of performance in the practical application, and therefore a kind of water-absorbing resin that is suitable for practical application is provided.
Pass through broad research for this reason, the present inventor finds, receptivity is with the variation of salt concentration, promptly the variation of receptivity has a significant impact practical application (as diaper) under specified pressure, and when water-retaining agent (under pressure) just can make water-retaining agent better than traditional product when having constant receptivity and constant water-permeable, thereby finish the present invention.These performance nones can be realized with out-of-date methods.
In other words, the invention provides a kind of main component that contains and be the particulate water absorbent containing of water-resin for inhaling, it is to make water-soluble unsaturated monomer is crosslinked.This size range that water-absorbing resin shape is special and it is particles contained is for being no less than 106um and being less than 850um, and its quality is the 90-100% of water-absorbing resin total mass.Particulate water absorbent containing has the first salt concentration absorptive index, as estimating that as the salt concentration aqueous solution such as grade and by following formula (1) its value is not less than 0.60 with ion exchanged water.
(salt concentration absorptive index)=(receptivity of the reciprocity salt concentration aqueous solution under 4.83KPa pressure)/(receptivity of equity salt concentration aqueous solution during no pressure) ... .. (1)
Molecule is particulate water absorbent containing and waits 60 minutes receptivities under 4.83KPa pressure of salt concentration aqueous solution soaking in the formula, and denominator is particulate water absorbent containing and waits 60 minutes receptivities under no pressure of salt concentration aqueous solution soaking.
In addition, the invention provides with the water-absorbing resin is the particulate water absorbent containing of main component, and this water-absorbing resin forms by water-soluble unsaturated monomer is crosslinked.Special and the particles contained size range of water-absorbing resin shape is 106um-850um, and its quality is no less than 90% of water-absorbing resin total mass.Particulate water absorbent containing soaks 60 minutes receptivities under 4.83KPa pressure when it with ion exchanged water and is not less than 50g/g.
In order to more fully understand essence of the present invention and advantage, should consult subsequently detailed description and accompanying drawing.
Brief Description Of Drawings
Fig. 1 is a cross sectional representation, illustrates to measure gel infiltration exponential measuring apparatus.
Best mode for carrying out the invention
Describe in detail below according to particulate water absorbent containing of the present invention (water-retaining agent).Though the present invention can do various modifications and take other form, below with its special case of example in detail.But should be appreciated that doing like this is not to limit the invention to disclosed special shape, on the contrary, present invention resides in interior all modifications, Equivalent and the surrogate of the scope of the invention of attached power requirements definition.
Proposed a kind of salt brine solution (0.9% (quality) NaCl aqueous solution) and multiplely be used for assessing the synthetic urine of the various performances of water-absorbing resin as urine sample.But all these propose all to have ignored a fact, and promptly the people urinates composition and alters a great deal, and is disclosed as aforementioned publication.In fact, the composition of urine is uneven, and it is very big with environment, diet, age, season and various other factors vary.Even same people, according to situation or his physical appearance at that time, the composition per minute of urine all is on the turn.
The problem that the present invention exists in view of tradition and proposing.Tradition is with typical solution, as salt brine solution or the synthetic performance of assessing water-absorbing resin of urinating.In other words, traditional water-absorbing resin of practical application can not change fully adaptation to the urine composition.
By this problem, the present inventor has considered the variation of salt concentration in the urine.
In detail, have found that the ionic strength of adult's urine is substantially equal to the ionic strength of 0.8-1.0% (quality) the NaCl aqueous solution, and the ionic strength of baby's urine is substantially equal to the ionic strength of 0.30.7% (quality) the NaCl aqueous solution.For the newborn infant, the ionic strength of its urine is substantially equal to the ionic strength of 0.2-0.4% (quality) the NaCl aqueous solution.It is not always suitable also finding to assess with the tradition of salt brine solution (0.9% (quality) NaCl aqueous solution) assessment water-absorbing resin performance, and problem is in fact arranged in actual applications, because it does not consider the actual salt concentration urinated.
In addition, the reason that traditional water-absorbing resin does not possess the practical application desired properties is that urine is urinated experience ion-exchange when drainage is oozed out by diaper, so improvement (decline) gradually takes place salt concentration in the urine.In fact, when urine oozed out diaper, the salt concentration of urine changed with different rates at the diaper different sites.
Therefore, the present inventor finds, when particulate water absorbent containing is main component with the water-absorbing resin and forms by water-soluble unsaturated monomer is crosslinked, when this water-absorbing resin has special shape and its particulate size range is 106um-850um, its quality accounts for water-absorbing resin total mass 90-100%, and when the first salt concentration absorptive index of particulate water absorbent containing by formula (1) (definition later on) calculating and with ion exchanged water as etc. during the salt concentration aqueous solution, just can provide receptivity constant senior particulate water absorbent containing, no matter whether salt concentration changes.
Particulate water absorbent containing of the present invention provides good gel infiltration index, no matter whether salt concentration or institute's plus-pressure change.Therefore, when with this absorption agent as the abundant permeation liquid of absorbing material, thereby improve absorbate quantity.In fact can effectively prevent to leak with particulate water absorbent containing of the present invention.
Describe particulate water absorbent containing of the present invention below in detail.
(water-absorbing resin is the cross-linked polymer of water-soluble unsaturated monomer)
Water-retaining agent of the present invention is main component with the water-absorbing resin, and can comprise a small amount of other composition, comprises additive and water.The characteristic of this water-retaining agent is to contain water-absorbing resin, and the pure content of resin is roughly 50-100% (quality), and 70-100% is better, and 85-100% is better, and 95-100% is better.This water-retaining agent shape is special, the following describes.In addition, water-retaining agent has the physical property that meets particular value.
Water-absorbing resin of the present invention is a kind of cross-linked polymer, and its can bulking, and is water insoluble substantially and be the well-known bulking cross-linked polymer of the water-fast basically negatively charged ion of a kind of formation, nonionic or cationic hydrogel.This water-absorbing resin internal crosslinking also can surface-crosslinked or surface treatment.In the present invention, these multi-form water-absorbing resin general designations " water-absorbing resin ".But will there be the water-absorbing resin of surface-crosslinked water-absorbing resin and other tabulation hand-deliver connection to make a distinction under some situation as required.
In the present invention, " bulking " is meant to immerse in the ion exchanged water and can absorbs 5g/g water at least, preferably be no less than the water of 50-1000g/g.Equally, among the present invention, " water insoluble basically " refers to that water-soluble amount (water-soluble amount of polymers) of water-absorbing resin is 050% (quality), and 0-20% (quality) is better, and 0.01-15% (quality) is better, and 0.1-10% (quality) also will get well.In these several different range, preferred especially 0.1-5% (quality), most preferably 0.1-3% (quality).(noticing that the method for receptivity and water-soluble amount of measuring is seen following example)
Water-absorbing resin is a kind of polymkeric substance, or two or more mixture of polymers.Say in detail, preferably a kind of polymkeric substance that contains acid group of water-absorbing resin, or contain the polymkeric substance of carboxylic acid or carboxyl (carboxylate salt) or these mixture of polymers.More detailed theory, the water-absorbing resin main component is preferably a kind of to be the cross-linked polymer that water-soluble cross-linking monomer of main component is polymerized with vinylformic acid and/or its salt (neutralizing agent), promptly the polyacrylic ester cross-linked polymer can contain the grafting composition if necessary.
Vinylformic acid that preferably contains 0-50% (mole) as the vinylformic acid and the acrylate of water-absorbing resin tectonic element and the acrylate (these material total amounts are no more than 100% (mole)) of 100-50% (mole), be more preferably vinylformic acid and contain 10-40% (mole), acrylate contains 90-60% (mole) (these material total amounts are no more than 100% (mole)).Acrylate is called " neutralization ratio " to the molar ratio of vinylformic acid and acrylate total amount.
Constituting unitary acrylate as water-absorbing resin is the vinylformic acid formation that neutralizes in water-absorbing resin.Neutralizing effect can be finished with monomeric form before polymerization, also can finish with polymer form in polymerization process He after the polymerization.On the other hand, neutralization can these neutralization method be finished jointly.Constitute the unit as water-absorbing resin, contained salt has: an alkali metal salt, and as (gathering) sodium acrylate, (gathering) potassium acrylate, and (gathering) vinylformic acid lithium; (gathering) ammonium acrylate; And (gathering) acrylic amine.
In order to promote polymerization and restriction colour developing, preferably contain p methoxy phenol (also being quinhydrones-methyl ether) as the vinylformic acid of the water-soluble unsaturated monomer of the present invention.Acrylic acid p methoxy phenol content is no more than 200ppm with respect to the vinylformic acid quality, and the 10-160ppm quality is better, and the 20-140ppm quality also will be got well, the 30-120ppm better quality.In these several scopes, 40-100ppm (quality) is preferred especially, and 50-90ppm (quality) most preferably.The quality of protoanemonin and/or furfural is acrylic acid 0-20ppm in the vinylformic acid, and 0-10ppm (quality) is better.In these scopes, 0-3ppm (quality) is preferred especially, and 0-1ppm (quality) most preferably.
Being used to produce the water-soluble unsaturated monomer of the present invention of water-absorbing resin, can having only vinylformic acid (or its salt) basically, also can be other several water-soluble unsaturated monomers.On the other hand, these different types of water-soluble unsaturated monomers comprise vinylformic acid (or its salt), can use together.The indefiniteness unsaturated monomer of non-vinylformic acid (and salt) comprising: the negatively charged ion unsaturated monomer, as methacrylic acid, toxilic acid, the vinyl sulfonic acid ester, styrene sulfonate, 2-(methyl) acrylamide-2-methyl propane sulfonic acid ester, 2-(methyl) acryloyl ethane sulfonic acid ester, 2-(methyl) acryloyl propane sulfonic acid ester and their salt: comprise hydrophilic radical non-ionic type unsaturated monomer, as acrylamide, Methacrylamide, N-(methyl) acrylamide ethyl ester, N-N-(methyl) acrylamide propyl ester, N-(methyl) acrylamide isopropyl ester, N-N-dimethyl (methyl) acrylamide, 2-hydroxyethyl (methyl) acrylate, 2-hydroxypropyl (methyl) acrylate, methoxy poly (ethylene glycol) (methyl) acrylate, polyethyleneglycol (methyl) acrylate, vinyl pyridine, N-vinyl pyrrolidone, N-Antiepilepsirin, N-acryloyl tetramethyleneimine, and N-vinyl acetamide; And positively charged ion unsaturated monomer, as N-N-diethylamino ethyl (methyl) acrylate, N-N-diethylamino ethyl (methyl) acrylate, N-N-dimethylaminopropyl (methyl) acrylate, N-N-dimethylaminopropyl (methyl) acrylamide, and their quaternary salt.These unsaturated monomers both can be used separately, but also two or more appropriate combination is used.
For making water-absorbing resin that desirable performance be arranged, the present invention is a main component with vinylformic acid and salt thereof.Can use other the water-soluble unsaturated monomer that exemplifies above in case of necessity together, its total amount is generally 0-30% (mole), and 0-20% (mole) is better, and 0-10% (mole) is better.
So that obtain water-absorbing resin of the present invention, can adopt mass polymerization or precipitation polymerization for making monomer polymerization.But consider the polymer properties of generation, the controllability of polymerization, the absorption characteristic of swell gel, better polymerization process is the aqueous polymerization and the reversible suspension polymerization of using monomer solution.When using monomer solution, monomer concentration is determined according to the temperature and the monomeric species of solution in the aqueous solution (to call " monomer solution " in the following text), therefore is not limited to arbitrary particular value.But this concentration is preferably 10-70% (quality), and 20-60% (quality) is better.When carrying out polymerization, can adopt the solvent of non-water as required with the aqueous solution.Solvent species is not limit.
In a kind of method of aqueous polymerization, monomer solution polymerization in a both arms kneader is pulverized the hydrogel cross-linked polymer that forms simultaneously.In another polymerization process, monomer solution is fed to predetermined container or travelling belt, and the equipment of application examples as meat-chopping machine will be pulverized because of the gel that polymerization produces.
For initiated polymerization, can use radical polymerization initiator, as Potassium Persulphate, Ammonium Persulfate 98.5, Sodium Persulfate, tertbutyl peroxide, hydrogen peroxide and 2, two (2-amidino groups-propane) dihydrochlorides of 2 '-azo; Or the use Photoepolymerizationinitiater initiater, as 2-hydroxy-2-methyl-1-phenyl-propane-1-ketone.These polymerization starters can use with reductive agent, can be beneficial to the decomposition of polymerization starter.That is, can use redox initiator, polymerization starter and reductive agent are combined.The indefiniteness example of reductive agent comprises: sulfurous acid (hydrosulfate), as S-WAT and sodium bisulfite; L-xitix (L-ascorbate salt); Reducing metal (reducing metal salt) is as ferrous salt; And amido.Consider residual monomer, absorption characteristic and other performance, the polymerization starter usage quantity is generally monomeric 0.001-2% (mole), and 0.01-1% (mole) is better.
Polymerization can cause by applying activation energy, as radiation, electron rays or ultraviolet ray, to reactive system.At this moment, above-mentioned polymerization starter can use together.The temperature of reaction of polyreaction is preferably in 15-130 ℃, and 20-120 ℃ better, but be not determinate, and they should be according to the polymerization starter kind of monomer kind, employing, and adjustment such as temperature of reaction.
Water-absorbing resin of the present invention has crosslinking structure (crosslinked in so-called) at its intramolecule.Crosslinked available any method produces in this, as long as the absorption agent finished product is water-fast.Specifically, also can finish interior crosslinked (self-crosslinking) without linking agent.But preferably crosslinked in finishing by the copolymerization building-up reactions of linking agent (internal crosslinker), these linking agents have at an intramolecularly and are no less than 2 polymerisable unsaturated groups or are no less than 2 active group.
The example of this internal crosslinker comprises: N, N '-methylene-bis (methyl) acrylamide, (gathering) ethylene glycol bis (methyl) acrylate, (gathering) propylene glycol two (methyl) acrylate, three (methacryloxypropyl methyl) propane, glycerine three (methyl) acrylate, glycerine esters of acrylic acid (methyl) acrylate, oxyethane sex change three (methacryloxypropyl methyl) propane, six (methyl) vinylformic acid pentaerythritol ester, triallyl cyanurate, triallyl isocyanurate, triallyl phosphate, amine triallyl, poly-(methyl) allyloxy alkane, (gathering) ethylene glycol diglycidylether, the glycerol diglycidylether, ethylene glycol, polyoxyethylene glycol, propylene glycol, glycerol, tetramethylolmethane, quadrol, ethylene carbonate, acrylate, polymine, and glycidyl methacrylate.
These internal crosslinkers can use separately, also can severally make appropriate combination and use.Internal crosslinker can once or divide and add in the reactive system several times.When using one or more internal crosslinkers, consider absorption characteristic or other performance of water-retaining agent finished product, will comprise that preferably the mixture of polymerisable unsaturated group more than two kinds is used for polymerization all the time.
In order to obtain to require the water-absorbing resin and the water-retaining agent of performance, the consumption of internal crosslinker is 0.001-2% (mole) with respect to the ratio of water-soluble unsaturated monomer (not comprising internal crosslinker), 0.005-1% (mole) is for well, 0.005-0.7% (mole) is better, 0.01-0.5% is better, 0.01-0.2% in this scope (mole) is preferred especially, and 0.03-0.15% (mole) most preferably.
When adopting internal crosslinker in that water-absorbing resin is inner when forming crosslinking structure, internal crosslinker before water-soluble polymerization of unsaturated monomers, among or add in the reactive system afterwards, or in water-soluble unsaturated monomer and the back add.
Note, when polymerization, can add the hydrophilic polymer (with respect to the quality of water-soluble unsaturated monomer) of following material to reactive system: 0-50% (quality), as starch and Mierocrystalline cellulose, starch and cellulosic derivative, polyvinyl alcohol, polyacrylic acid (polyacrylic ester), and cross linked polyacrylate (crosslinked polypropylene); The whipping agent of 0-10% (quality) (with respect to the quality of water-soluble unsaturated monomer), as (hydrogen) carbonic ether, carbonic acid gas, azo-compound, and nonactive organic solvent; Surfactant; Sequestrant; And chain-transfer agent, as Hypophosporous Acid, 50 (hypophosphate).
Dry during in polymerization or after the polymerization through hydrogel cross-linked polymer that polymerization process obtains.Bake out temperature is generally 60-250 ℃, and 100-220 ℃ better, and 120-200 ℃ best.Drying time is different with the long-pending stoving oven kind that reaches water-content and use of polymer surfaces.Usually drying time water-content was as requested elected 1 minute as-3 hours, and 10 minutes-2 hours better.The water-content of water-absorbing resin of the present invention is restriction especially not.(as term used herein, " water-content " is defined as institute's water content in the water-absorbing resin, with the ratio metering of its 1 gram water-absorbing resin weightlessness after drying 3 hours under 180 ℃ in the water-absorbing resin quality before drying).But consider that the water-absorbing resin finished product is a powder, at room temperature can flow that therefore for well, 0.3-15% (quality) is better with 0.2-30% (quality) for water-content, 0.5-10% (quality) is best.(noticing that term among the present invention " water-absorbing resin " also can be used even only contain the less water that is no more than 30% (quality)).
Manufacturing processed of the present invention comprises pulverizing process, and wherein the hydrogel cross-linked polymer drying operation that obtains with polymerization process is ground into granular water-absorbent resin with pulverizer again.The particle of this water-absorbing resin is not limited to a kind of shape, can be spherical, particle shape or irregular particle shape.But the hydrogel cross-linked polymer is preferably in and wears into irregular particle shape in the pulverizing process.
Among the present invention, the ratio of fine particle in water-retaining agent or water-absorbing resin preferably as far as possible little (granularity less than 106um, or less than 150um).Concrete scope is: fine grain ratio is less than 10% (quality), and is less than 5% for well, less than 3% better, less than 2% better, best less than 1%.In addition, in the present invention, a part of coarse particles in the water-absorbing resin (granularity is not less than 850um, or is not less than 500um) is preferably also few as far as possible.In other words, the particles contained diameter of water-absorbing resin of the present invention is 850-106um (preferably 850-150um), and the ratio that it accounts for is 90100% (quality), and 97-100% (quality) is for well, and 98-100% (quality) is better, and 99-100% (quality) is best.
Subsequently, granular water-absorbent resin becomes particulate water absorbent containing of the present invention by surface modification.Surface modification of the present invention both can also can be coated non-reactive additives at particle surface, as inorganic powder with particle surface or surface portion (the tens of microns of degree of depth 0.001um-).
Consider the performance of water-absorbing resin, surface-modifying agent is (as surface crosslinking agent in the water-absorbing resin of 100 parts (quality), or non-reactive additives, as water-fast fine particle) amount ranges be 0.001-10 part (quality), 0.01-8 part (quality) is better, 0.05-5 part (quality) is better, 0.1-2 part (quality) is best.
The surface-crosslinked cross-linking density of water-absorbing resin near surface that makes is higher than granule interior, thereby improves the water-absorbing resin performance.By adding one or more surface crosslinking agents (being called " second linking agent ") to water-absorbing resin, thereby only take place crosslinked when surface-crosslinked on the water-absorbing resin surface to be different from internal crosslinker.
The dehydrated crosslinking agent is used as surface crosslinking agent.When containing carboxyl in the water-absorbing resin, the special case of surface crosslinking agent comprises: the linking agent of hydroxyl, as polyvalent alcohol; Contain amino linking agent, as polyamines; And the ring-type linking agent, when ring is open, hydroxyl or amino be can produce, thereby hydroxyl or the amino crosslinking reaction that takes place made.The ring-type linking agent can be alkylene carbonate, Dan oxazolidone compound, Duo oxazolidone compound or oxetane compound (as 3-methyl-3-propylene oxide methyl alcohol).
The special case of dehydrated crosslinking agent has: polyol compound (as propylene glycol, 1,3-pentanediol, 2-methyl isophthalic acid, 3-pentanediol, glycerol, 1,4-butyleneglycol, and 1,5-pentanediol); The alkylene carbonate compound, as 1,3-dioxolane-2-ketone and 4-methyl isophthalic acid, 3-dioxolane-2-ketone; And (gathering) oxetane compound (as 3-methyl-3-oxetane methanol).In order to make the present invention that best effect be arranged, the dehydrated crosslinking agent of use is preferably selected polyvalent alcohol, alkylene carbonate, oxazolidone compound for use, is reached (gathering) oxetane compound.Preferably often use polyvalent alcohol.
Except above-mentioned dehydrated crosslinking agent, other example of surface crosslinking agent has: epoxy compounds (as the ethylene glycol bisthioglycolate Synthesis of Oligo Ethylene Glycol, and r-Racemic glycidol oxygen propyl trimethoxy silicane) Ji Ju oxazoline compound (as 1,2-Yi Xi bisoxazoline), silane coupling agent (as γ-An Bingjisanjiayangjiguiwan), the polyaziridine compound is (as 2, the two methylbutanes-three [3-(1-aziridinyl) propionic ester] of 2-), reach the non-dehydrated crosslinking agent of polyvalent metal (as beryllium, magnesium, calcium, strontium, zinc, aluminium, iron, chromium, manganese, titanium and zirconium).
Surface crosslinking agent used water and/or hydrophilic organic solvent mix with water-absorbing resin.
The water yield as solvent is 0.1-10 part of 100 parts of water-absorbing resin quality, and 0.5-8 part (quality) is better, and 1-5 part (quality) is best.
The example of hydrophilic organic solvent comprises: alcohol, as ethanol, propyl alcohol, Virahol; Ketone is as acetone; Ether, as diox, alkoxyl group (gathering) ethylene glycol, and tetrahydrofuran (THF); Acid amides is as ε-Ji Neixianan; And sulfoxide, as dimethyl sulfoxide (DMSO).The consumption of hydrophilic organic solvent is that 0-10 part of 100 parts of water-absorbing resin quality is better, and 0-5 part (quality) is better, and 0-3 part (quality) is best.
The blending means of surface crosslinking agent is not limited to a certain method.For example, surface crosslinking agent used water and hydrophilic organic solvent dissolve surface crosslinking agent separately and mix with water-absorbing resin.On the other hand, surface crosslinking agent can be dissolved in simultaneously in water and the hydrophilic organic solvent and mix.In addition, the surface crosslinking agent in water and/or the hydrophilic organic solvent can mix with dosage separately with water-absorbing resin.But surface crosslinking agent preferably mixes with solvent (water and/or organic solvent) earlier, adds in the water-absorbing resin with aqueous solution form subsequently.
Surface crosslinking agent also can mix with the hydrophilic or hydrophobic polymer phase of inorganic powder (being a kind of water-fast fine particle), surfactant in addition, as long as particulate water absorbent containing of the present invention still can work.
In these different blending meanss, the surface crosslinking agent in the water-soluble and/or hydrophilic organic solvent preferably dropwise mixes with water-absorbing resin.Surface crosslinking agent in the water-soluble and/or hydrophilic organic solvent sprays in the water-absorbing resin better.Mixed solution is atomised to 0.01-300um, and 0.01-200um is better.The temperature range of solution to be painted is the boiling point of 0 ℃-solution, and 5-50 ℃ better, and 10-30 ℃ best.Consider that mixing is convenient and stable, the powder temperature scope of water-absorbing resin is 0-80 ℃ before mixing, and considers that mixing is convenient, and 40-70 ℃ better.
The kind of the mixing tank that uses during mixing is unrestricted, as long as it can powerfully stir, reaches uniform mixing, produces powder.The example of this mixing tank has: cylindrical stirrer, double wall cone-type mixer, high-speed stirring formula amalgamator, wedge shape stirrer, strip-type mixing machine, screw mixer, fluid-bed furnace formula rotating disk mixing machine, pressurized air mixing machine, double-arm kneader, interior mixing machine, pulverizer, drum mixer, screw extrusion press.
When heating when in mixed processes, carrying out, heat-up time with 1-180 minute for well, better 5-100 minute was best in 3-120 minute.Heating temperature (by the definition of the temperature of heated medium or material) with 100-250 ℃ for well, 140-220 ℃ is better, 150-230 ℃ better, 160-220 ℃ is best.
The heating of available common drying machine or baker, for example plough groove type mixing drier, rotary-drum drier, disk dryer, fluidized bed type moisture eliminator, instrument air dryer, and infrared dryer.
When surface modification occurs in the water-absorbing resin production process of the present invention, can be with the surface-crosslinked while or do not take place simultaneously such as the such additive of inactive surfaces activator, inertia reodorant, nonactive fine inorganic particles.Refer to additive and water-absorbing resin Fails To Respond basically at this 'inertia'.Preferably inorganic or organic fine particle of surfactant and nonactive fine inorganic particles or lipid acid (as longer chain fatty acid or its salt) are stated as follows.These materials are preferably in when surface-crosslinked and add, and also can not add simultaneously.
Among the present invention, the cationic polymers mixing material that adds as the modifying surface of absorption resin additive can improve the performance of water-absorbing resin, as is easy to anchor on the sanitary product.For well, 5000-500000 is better with 2000-1000000 for the population mean molecular weight of cationic polymers mixing material, and 10000-500000 is best.Making the organic compound that the modifying surface of absorption resin additive uses is lipid acid or its salt, preferably longer chain fatty acid or its salt.
The cationic polymers mixing material can directly add, or adds with solution (aqueous solution) form.The preferred example of cationic polymers mixing material is: the partial hydrolysate of the condenses of polymine, polyvinylamine, polyacrylamide, polymeric amide and Epicholorohydrin, poly-amidine, poly-(N-vinyl formal), and the salt of these compounds.
In the present invention,, therefore can improve the perviousness of water-absorbing resin, when absorbing moisture, can improve the water-absorbing resin resistance to blocking owing to being additive with water-fast fine particle.The mean particle size that the water insoluble fine particle of organic or inorganic is suitable for is 0.0001-10um (diameter), and 0.001-1um is better, 0.001-0.1um better (particle diameter is measured with the Ku Erte counter).More detailed theory, water-fast fine grain material can be used silicon oxide (name of an article: Aerosil, by Nippon Aerosil Co., Ltd produces), titanium oxide or aluminum oxide.Blending means is just like dry blending or slurries blending.
Water insoluble fine grain consumption is to be no less than 10 parts of 100 parts of water-absorbing resin quality, and 0.001-5 part (quality) is better, and 0.01-2 part (quality) is best.
[manufacturing process of particulate water absorbent containing]
Following technology 1-3 is the preferred embodiment according to particulate water absorbent containing manufacturing process of the present invention.
[technology 1]
Polyacrylic acid (salt)-cross-linked polymer (water-absorbing resin) is with preceding method preparation, preferably uses the water soluble unsaturated monomer that contains a small amount of protoanemonin under the situation of methoxyphenol having.The water-absorbing resin that makes like this, its particle size is modulated to above-mentioned scope, and the receptivity of not having under the pressure for 0.90% (quality) NaCl aqueous solution (60 minutes values) is adjusted to 15-27g/g.Subsequently, preferably by the surface-crosslinked water-absorbing resin generation surface modification that makes, thereby form particulate water absorbent containing of the present invention, it is 10-27g/g for the receptivity (60 minutes values) that 0.90% (quality) NaCl aqueous solution does not have under the pressure, 12-27g/g is better, 15-27g/g is better, and 17-27g/g also will get well, and 18-22g/g is best.
[technology 2]
Polyacrylic acid (salt) cross-linked polymer (water-absorbing resin) is having under the situation of methoxyphenol water-soluble unsaturated monomer of use prepare as stated above.Subsequently the granularity of water-absorbing resin is transferred to above-mentioned specified range, and will 0.90% (quality) NaCl aqueous solution not had relative receptivity under the pressure (following definition) and be transferred to 10-27g/g, 12-27g/g is for well, and 15-27g/g is better, 17-25g/g is better, and 18-22g/g also will get well.After this, the fine inorganic particles by above-mentioned specified range is coated on the surface of the water-absorbing resin that its granularity and receptivity (not having 60 minutes values when pressing) are adjusted, thereby forms particulate water absorbent containing of the present invention.
[technology 3]
The water soluble unsaturated monomer of handy a small amount of protoanemonin prepares polyacrylic acid (salt) cross-linked polymer (water-absorbing resin) as stated above having under the situation of methoxyphenol.Subsequently the granularity of water-absorbing resin is adjusted to above-mentioned scope, will not have under the pressure the relative receptivity (values after 60 minutes) of 0.90% (quality) NaCl aqueous solution is adjusted to 17-25g/g, 18-22g/g is better.After this, lipid acid or its salt are coated in the surface of the adjusted water-absorbing resin of its granularity and receptivity (following 60 minutes values of no pressure), thereby form particulate water absorbent containing of the present invention.
Preferably crosslinked according to above-mentioned technology 2 and technology 3 at the granular water-absorbent resin that absorbs resin surface coating acquisition, make under the no pressure receptivity (60 minutes values) adjust to 10-27g/g to 0.90% (quality) NaCl aqueous solution, 12-27g/g is for well, 15-27g/g is better, 17-25g/g is better, and 18-27g/g is best.
" receptivity (60 minutes values) of 0.90% (quality) NaCl aqueous solution under the no pressure " used herein refers to particulate water absorbent containing in the receptivity of soaking 0.90% (quality) NaCl aqueous solution particulate water absorbent containing (water-absorbing resin) after 60 minutes under the pressure.At this, use excessive 0.90% (quality) NaCl aqueous solution, so it can not absorbed by particulate water absorbent containing all.
People think that easily traditional water-retaining agent (water-absorbing resin) has high receptivity.In fact, the receptivity of the main product of having bought in the market generally is not less than 30g/g, and it is better to be not less than 35g/g, and it is better to be not less than 40g/g.Although this trend is arranged, the present invention will not have water-absorbing resin under the pressure audaciously when novel particulate water absorbent containing is provided receptivity is limited in the scope that is lower than traditional water-absorbing resin.
In addition, water-retaining agent of the present invention through after the surface treatment to 0.90% (quality) NaCl aqueous solution in the receptivity under the pressure (60 minutes value) preferably in the 15-27g/g scope, 17-25g/g is better." to the receptivity (60 minute value) of 0.90% (quality) NaCl aqueous solution under pressure " used herein refers to that particulate water absorbent containing soaks (contact) 0.90% (quality) NaCl aqueous solution receptivity under 4.83KPa pressure in the time of 60 minutes.
The control method of the receptivity of particulate water absorbent containing is the quality of control surface reagent treatment and/or reaction conditions etc.Therefore, the cross-linking density of water-absorbing resin is adjusted before being preferably in surface treatment in the polymerization process, thereby makes it reach 40-15g/g, 35-16g/g, or 30-17g/g to the receptivity of 0.90% (quality) NaCl aqueous solution under no pressure.In addition, the granularity of water-absorbing resin is controlled in the above-mentioned specified range before the surface treatment.
[water-retaining agent of the present invention]
The particulate water absorbent containing of the present invention that obtains like this, its excellent performance part is that the receptivity under its pressure (AAP) depends on the salt concentration that absorbs liquid hardly, even under the 4.83KPa high pressure.More detailed theory, in actual applications, water-retaining agent of the present invention its performance with regard to receptivity is constant, no matter how many salt concentrations of urine is, in other words, the water absorbing properties of water-retaining agent remains on desired horizontal, no matter the vicissitudinous situation of salt concentration when using diaper or in the diaper.
Particulate water absorbent containing of the present invention is main component with the water-absorbing resin, and this water-absorbing resin is the cross-linked polymer of water-soluble unsaturated monomer.Particulate water absorbent containing comprises granular water-absorbent resin, and its size range is 106um (preferably being not less than 150um)-850um, accounts for the 90-100% of the contained water-absorbing resin total mass of particulate water absorbent containing.The granular water-absorbent resin that particulate water absorbent containing comprises, its granularity is preferably between the 150um-850um, accounts for more than 95% of contained water-absorbing resin total mass of particulate water absorbent containing (hereinafter to be referred as " particle "), is preferably in more than 98%.The ensemble average granularity of granular water-absorbent resin is preferably 200-700um, and 300-600um is better.In these different range, 350-550um is preferred especially, and 400-500um most preferably.
Diameter should not surpass 10% (quality) less than the particle total amount of 150um, because it can stop such as blood or urinate such diffusion of body fluids to water-retaining agent.Another reason is, when being absorption agent with this water-retaining agent, it increases the area of ingress of air, and particulate water absorbent containing is dissolved easily as a result.In addition, the particle total amount that surpasses 850um is should exceed 10% (quality) not also, because its reduces water-retaining agent rate of water absorption.
In addition, except the granularity of specialized range, the receptivity of particulate water absorbent containing of the present invention under pressure is constant, no matter salt concentration how.In the present invention, the solution (0-0.90% (quality) the NaCl aqueous solution) that is defined as different saltness of the receptivity under the pressure is soaking the receptivity that records behind the certain hour under the 4.83KPa pressure.Receptivity has found that it is to adapt to the variation of the body-fluid concentration as urine in the practical application most under the pressure thus defined.
More particularly, except the granularity of specialized range, water-retaining agent of the present invention has the first salt concentration absorptive index, is when waiting salt concentration aqueous solution, to record its value by formula (1) and be not less than 0.60 when using ion exchanged water.
(salt concentration absorptive index)=(in the receptivity of the inferior salt concentration aqueous solution of 4.83KPa pressure)
/ (receptivity of the inferior salt concentration aqueous solution of no pressure) ... ... (1)
In the formula, molecule is to soak (contact) the salt concentration aqueous solution of etc.ing receptivity under 4.83KPa pressure after 60 minutes when particulate water absorbent containing, and the denominator aqueous solution such as salt concentration such as grade that to be the particulate water absorbent containing immersion excessive receptivity under the no pressure after 60 minutes.
The first salt concentration absorptive index to be to be not less than 0.70 for well, is not less than 0.80 better, is not less than 0.90 better, is not less than 0.95 best.The first salt concentration absorptive index is bad less than 0.60, because at this moment to the receptivity under the specific salt concentration aqueous solution water-absorbing resin pressure along with salt concentration changes (decline), the i.e. salt concentration variation (decline) that causes by the diaper diffusion because of urine, and great changes have taken place (fluctuating).Enough performances are arranged when at this moment being difficult to guarantee practical application.When the first salt concentration absorptive index upper limit is too high, also have same phenomenon.Therefore, the upper limit of the first salt concentration absorptive index to be to be no more than 1.20 for well, is no more than 1.10 better.(it should be noted that index 0.60 and 0.600 is the same.After this manner, when the value of narration salt concentration absorptive index or salt tolerance index, only provide the first two numeral of radix point the right).
In addition, except the viscosity and the first salt concentration absorptive index of specialized range, particulate water absorbent containing of the present invention should have other following performance, to guarantee the variation (decline) along with the salt concentration of urine, the salt concentration that promptly sees through the urine of diaper changes (decline), and the absorption of urine is stable.
Specifically, particulate water absorbent containing of the present invention, its second salt concentration absorptive index preferably is not less than 0.80 when measuring with above-mentioned formula (1), and the wherein said second salt concentration absorptive index is the salt concentration absorptive index when waiting salt concentration aqueous solution to be 1% (quality) NaCl aqueous solution.The second salt concentration absorptive index is not less than 0.90 for well, is not less than 0.95 better, and the upper limit of the second salt concentration absorptive index is not more than 1.20, preferably is not more than 1.10.
In addition, except granularity and the first salt concentration absorptive index specialized range, particulate water absorbent containing of the present invention preferably have third and fourth, five, six salt concentration absorptive indexs, they wait the salt concentration aqueous solution respectively is 0.30%, 0.50%, 0.70%, 0.90% (quality) NaCl aqueous solution and measuring with above-mentioned formula (1), wherein said third and fourth, five, six salt concentration absorptive indexs have at least one to be not less than 0.90.3-6 salt concentration absorptive index preferably is not less than 0.95, and its upper limit generally is not more than 1.20, preferably is not more than 1.10.
In addition, except granularity and the first salt concentration absorptive index inside and outside specialized range, in the particulate water absorbent containing of the present invention, its average salt concentration absorptive index as in third and fourth, the mean value of five, six salt concentration absorptive indexs, preferably be not less than 0.90.Average salt concentration absorptive index preferably is not less than 0.95, and its upper limit generally is not more than 1.20, preferably is not more than 1.10.In addition, the standard tolerance of average salt concentration absorptive index is preferably 0-0.100, and 0-0.05 is better.
In addition, except granularity and the first salt concentration absorptive index inside and outside specialized range, first salt tolerance index of particulate water absorbent containing of the present invention is not less than 0.40 when calculating as the salt concentration aqueous solution such as grade and by following formula (2) with 0.10% (quality) NaCl aqueous solution.
(salt tolerance index)=(waiting the receptivity of the salt concentration aqueous solution under no pressure)/
(receptivity of ion exchanged water under no pressure) ... (2)
Molecule is that particulate water absorbent containing soaks the excessive salt concentration aqueous solution that waits and do not have water-retaining capacity pressure under in the time of 60 minutes in the formula, and denominator to be particulate water absorbent containing immersion ion exchanged water do not have the receptivity under the pressure in the time of 60 minutes.The lower limit of first salt tolerance index preferably is not less than 0.50, and the upper limit generally is not more than 1.20, preferably is not more than 1.10.
Receptivity (15-27g/g) in specialized range under the no pressure of particulate water absorbent containing of the present invention.For 0.90% (quality) NaCl aqueous solution, receptivity (60 minutes value) be 10-27g/g, and 12-27g/g is for well, and 15-27g/g is better, and 17-25g/g is better, and it is best to reach 18-22g/g.
In addition, particulate water absorbent containing of the present invention, its gel infiltration index (GPI, unit: 10 -7* cm 3* s * g -1, below omit and do not write) preferably be not less than 10.According to broad research result to the variety of issue of traditional water-retaining agent, the present inventor finds, the gel infiltration index (GPI) of tradition water-retaining agent is along with the increase of salt concentration (variation that causes salt concn by the ion-exchange or the motion of liquid in ambient environmental conditions or the absorption agent), or the increase of pressure (weight or posture by the personnel that use absorption agent change the pressure change that causes) and reducing greatly.Have found that this is unfavorable for the infiltration of expansible absorption agent to absorbent solution (as urine).On the other hand, particulate water absorbent containing of the present invention can guarantee that the gel infiltration rate is stable, no matter salt concentration or pressure have no change.Therefore, use particulate water absorbent containing of the present invention, solution is osmotic absorbent (diffusion area increase) fully.In addition, this absorption agent can absorb more solution and can not make leak of liquid.The value of GPI preferably is not less than 15, is not less than 20 better.Explain GPI in the example below in detail.
In particulate water absorbent containing of the present invention, the GPI to ion exchanged water under 2.07KPa pressure is not less than 10, is not less than 15 for well, is not less than 20 better.This scope of GPI is far above the GPI scope 0-1 of traditional absorption agent, and can not descend much with the raising of pressure.In addition, in particulate water absorbent containing of the present invention, the GPI of 0.3-0.9% (quality) the NaCl aqueous solution under 2.07KPa pressure is not less than 10, is not less than 20 for well, is not less than 50 better, is not less than 100 better, is not less than 150 best.These scopes of GPI are far above 0 to tens of the GPI of traditional absorption agent, and can not increase with salt concentration and descend a lot.In addition, in particulate water absorbent containing of the present invention, the GPI of 0.7% (quality) NaCl aqueous solution under 4.83KPa pressure is not less than 10, is not less than 15 for well, is not less than 20 better.These scopes of GPI are far above traditional absorption agent GPI 0-1, and it is a lot of can not descend with the salt concentration raising.In fact, the GPI of 0.3-0.9% (quality) the NaCl aqueous solution under 2.07KPa have only very little variation and be not less than 150 o'clock stable.As mentioned above, particulate water absorbent containing of the present invention is stable and GPI is high, does not change no matter salt concentration or pressure have, thereby good absorptive character (diffusion area is big, and uptake rate is fast) are arranged during in actual applications as absorption agent.
In addition, particulate water absorbent containing of the present invention has fine water-retaining capacity, and its receptivity (60 minutes values) to ion exchanged water under 4.83KPa pressure is not less than 50g/g, and it is better to be not less than 60g/g, and it is better to be not less than 70g/g.Should point out that the receptivity upper limit under the pressure can be without limits, and preferably have high value, consider manufacturing cost and other economic factors, the upper limit of receptivity is preferably 200g/g under the pressure, and 150g/g is better.
Therefore, the invention provides a kind of new-type particulate water absorbent containing, as follows.This particulate water absorbent containing is main component with the water-absorbing resin, and water-absorbing resin is the cross-linked polymer of water-soluble unsaturated monomer.Special and its particulate size range of water-absorbing resin shape is 106-850um, and its quality accounts for 90% of the contained water-absorbing resin total mass of particulate water absorbent containing.The receptivity of particulate water absorbent containing under pressure is not less than 50g/g when it is immersed in the water-retaining capacity that recorded in 60 minutes in the ion exchanged water under 4.83KPa pressure.This particulate water absorbent containing is used the receptivity of ion exchanged water is represented, performance is more superior than traditional specific absorption, and receptivity is strong especially when hyposaline concentration.The most handy salt concentration absorptive index of particulate water absorbent containing of the present invention, salt tolerance index, average salt concentration absorptive index and standard tolerance and its feature of gel infiltration exponent specification.
[other additives]
Except the additive of the hand-deliver of tabulation when surface treatment coupling, can add other additive (to call " other additive " in the following text) on demand.The example of this other additive comprises: reodorant, antiseptic-germicide, aromatoising substance, whipping agent, pigment, dyestuff, hydrophilic staple fibre, softening agent, tackiness agent, surfactant, fertilization medium, oxygenant, reductive agent, water, salt, sequestrant, sterilizing agent, hydrophilic polymer (as polyoxyethylene glycol and polymine), hydrophobic polymer (as paraffinic hydrocarbon), thermoplastic resin (as polyethylene and polypropylene), thermosetting resin (as vibrin and urea-formaldehyde resin).These additives can add in adding step, give water-absorbing resin various performances.These additives are preferably in to add in the step and add the water-absorbing resin surface to.
The consumption of these additives is roughly the 0-30% (quality) of 100% (quality) water-absorbing resin, and 0-10% (quality) is better, and 0-1% (quality) is better.
[application of water-retaining agent]
Particulate water absorbent containing of the present invention provides stable receptivity, no matter salt concentration how.This makes this particulate water absorbent containing can be applicable to a lot of fields, keeps product as the moisture of agricultural or horticulture, and industrial moisture maintenance product, remove to moisten agent or material of construction at siccative.But this water-retaining agent is particularly useful for the paper nappy to be the sanitary product of representative and to be used for the absorbed body fluid sanitary towel of (comprising ight soil, urine and blood).
Particulate water absorbent containing stable performance of the present invention and balance, this makes this particulate water absorbent containing can be applicable to highdensity hygienic absorption product, so-called density is water-absorbing resin weight and the ratio of water-absorbing resin and filamentary material gross weight, stopping composition density ratio definition by following formula (3), its value is 30-100% (quality), 40-100% (quality) is better, and 50-95% (quality) is better.
(stopping composition density ratio)=(particulate water absorbent containing quality)/(particulate water absorbent containing quality+mass of fibre material)
....(3)
Absorbing material (absorbing the matrix material of stopping composition and water-retaining agent) can be attached in the sanitary product with any form.For example, absorbing material can be a sandwich structure, and wherein water-retaining agent is placed between each sheet hydrophilic fibers material; Also can be the fusion structure, wherein water-retaining agent and hydrophilic fibers material mixing.
[embodiment]
Following with reference to embodiment and Comparative Examples detailed description the present invention.But should recognize fully that the present invention is only limited to following special shape.In addition, as term used herein, " umber " refers to " umber of quality (weight) ", except as otherwise noted.
Notice that except as otherwise noted, all measurements are to be 25 ℃ ± 1 ℃ in free air temperature and fluid temperature, under atmospheric pressure, relative humidity is less than carrying out under 5% the condition.
In addition, when doing the measurement of water-retaining agent or the above-mentioned coefficient of water-absorbing resin (explanation later on), the water-retaining agent of use or water-absorbing resin all are not do any improvement to handle.But when water-retaining agent or the excessive moisture of water-absorbing resin absorption, be that water-retaining agent or water-absorbing resin are taken from such as the such absorbent item of diaper, then will be after finishing following steps measure: water-retaining agent or water-absorbing resin be drying treatment suitably under low pressure for example again, make it for example constant quality arranged under 60 ℃, its water content is adjusted to and is not more than 7 ± 1% (quality), preferably be not more than 5 ± 1%<<
The preparation of<solution 〉
In order to assess the absorptive character of water-retaining agent or water-absorbing resin (particulate water absorbent containing), the present invention has used the NaCl aqueous solution that ion exchanged water and salt concentration do not wait.
-solution S 0Ion exchanged water
-solution S 1: the aqueous solution of 0.10% quality (weight) NaCl
-solution S 2: the aqueous solution of 0.20% quality (weight) NaCl
-solution S 3: the aqueous solution of 0.30% quality (weight) NaCl
-solution S 4: the aqueous solution of 0.40% quality (weight) NaCl
-solution S 5: the aqueous solution of 0.50% quality (weight) NaCl
-solution S 6: the aqueous solution of 0.70% quality (weight) NaCl
-solution S 7: the aqueous solution of 0.90% quality (weight) NaCl
<water-retaining capacity (60 minutes receptivities (GV, gel volume) of no pressure) 〉
The water-absorbing resin (or water-retaining agent) of 0.20g is distributed on nonwoven fabric belts, and (in the 60mm * 60mm), cloth bag is immersed in S 0To S 7Every kind of excessive (100g at least) solution in.After 60 minutes, take out cloth bag, with 250G acceleration running 3 minutes, remove the water in the cloth bag, measure the heavy W2 (g) of bag with the ion isolation machine.
Notice that when the swelling coefficient of water-absorbing resin (or water-retaining agent) is bigger, when cloth bag weight W 2 (g) were greater than 15 (g) simultaneously, the dosage of water-absorbing resin (or water-retaining agent) can suitably be adjusted to and be not more than 0.20g in the bag.Specifically, to solution S 0-S 3, the dosage of water-absorbing resin (or water-retaining agent) is transferred to 0.01-0.05g.Equally, solution S 4, S 5Dosage be 0.05-0.15g, solution S 6, S 7Dosage be transferred to 0.10-0.20g.By this way, the heavy W2 of bag (g) is adjusted in 5-15 (g) scope.
The empty bag that does not contain water-retaining agent or water-absorbing resin is also done like this, and measures the weight W 1 (g) of empty bag.Then, separate following formula (4), with the weight W that records 1And W 2Obtain receptivity (g/g):
Figure A20048000010400211
Receptivity under the<pressure (AAP) 〉
Stainless steel 400 purpose standard filter screens (size of mesh 38 μ m) are attached to the plastic support cylinder bottom face of internal diameter 60mm, evenly spray water-absorbing resin or the water-retaining agent of 0.9000g on filter screen.Piston external diameter is slightly less than 60mm, is finish-machined to seamlessly to be assembled in the shoring, but can does free vertical movement in cylinder.Piston is adjusted to the power that can evenly apply 4.83KPa (0.7psi) on water-absorbing resin or water-retaining agent.The following order of magnitude of piston and load is added on water-absorbing resin or the water-retaining agent, measures the total mass Wa (g) of time measuring apparatus.Then, the glass filter of a diameter 90mm (is produced by Japanese Sougo RikagaKu Garasu SeisaKusho company limited; Aperture 100-120 μ m) is placed on the having in the cover glass dish of diameter 150mm, adds every kind of solution to glass filter end face level.
The filter paper of a diameter 90mm (ADANTEC Toyo Kaisha Ltd makes, trade(brand)name: (qualitative filter paper, JSPP 3801, NO.2), thick 0.26mm, minimum-value aperture 5 μ m) puts into glass filter), thereby complete wetting filter paper, and absorb too much solution.
Subsequently survey instrument is placed on the wet filter paper solution of absorbing contact under pressure.After 1 hour, mention survey instrument, measure the weight W of survey instrument b(g), the W that records aAnd W bValue is used the receptivity (g/g) under following formula (5) calculating pressure:
<salt concentration absorptive index 〉
Salt concentration absorptive index of the present invention has pressure or does not have the solution (S that depresses according to what record 0, S 1-S 7) water-retaining capacity calculate:
" receptivity under the pressure " is that water-absorbing resin or water-retaining agent soak the receptivity under 4.83KPa pressure in the time of 60 minutes such as (contact) the salt concentration aqueous solution in the formula, and do not have the receptivity under the pressure 60 minutes the time in " receptivity under the no pressure " to be water-absorbing resin or water-retaining agent be immersed in salt concentration aqueous solution such as excessive.
The first salt concentration absorptive index used herein is the brine concentration absorptive index when being the medium salt concentration aqueous solution of following formula (1) with the ion exchanged water.Equally, the second salt concentration absorptive index be with 0.10% (quality) NaCl aqueous solution be in the formula (1) wait the salt concentration aqueous solution time the salt concentration absorptive index.The 3rd salt concentration absorptive index be with 0.30% (quality) NaCl aqueous solution be in the formula (1) wait the salt concentration aqueous solution time the salt concentration absorptive index.The 4th salt concentration absorptive index be with 0.50% (quality) NaCl aqueous solution be in the formula (1) wait the salt concentration aqueous solution time the salt concentration absorptive index.The 5th salt concentration absorptive index be with 0.70% (quality) NaCl aqueous solution be in the formula (1) wait the salt concentration aqueous solution time the salt concentration absorptive index.The 6th salt concentration absorptive index be with 0.90% (quality) NaCl aqueous solution be in the formula (1) wait the salt concentration aqueous solution time the salt concentration absorptive index.
<salt tolerance index 〉
According to the receptivity under the no pressure that records, available following formula (2) is obtained salt tolerance index.
Figure A20048000010400231
" receptivity under the no pressure " is that water-absorbing resin or water-retaining agent soak the receptivity of the salt concentration aqueous solution in the time of 60 minutes such as (contacts) in the formula.At this, first salt tolerance index is the salt tolerance index when being the medium salt concentration aqueous solution of following formula (2) with 0.1% (quality) NaCl aqueous solution.
<weight (quality) median size 〉
With the JIS standard filter screen screening water-absorbing resin or the water-retaining agent that comprise various size of meshes such as 850 μ m, 710 μ m, 600 μ m, 500 μ m, 425 μ m, 300 μ m, 212 μ m, 150 μ m, 106 μ m and 75 μ m, the percentage ratio of remainder particulate is painted on the probability logarithmic paper with curve.This graphic representation is drawn weight average particle diameter (D50).
The water-absorbent resin powder of 10.00g or water-retaining agent put into (the IIDA testing sieve: internal diameter 80mm) its size of mesh comprises 850 μ m, 710 μ m, 600 μ m, 500 μ m, 425 μ m, 300 μ m, 212 μ m, 150 μ m, 106 μ m and 75 μ m on the JIS standard filter screen, and water-absorbent resin powder or water-retaining agent are made 10 minutes size classification with the screen cloth shaking apparatus (IidaSeisakusho Co., the ES-65 screen cloth shaking apparatus that Ltd produces) of low relief outlet.Note, the term of Ying Yonging here, " weight average particle diameter (D50) " is the filter screen size, can take this to use screen cloth shaking apparatus (United States Patent (USP) 5051259) and work 10 minutes, with the particle classification of water-absorbing resin or water-retaining agent particle gross weight 50%.
<water-soluble amount (solvable amount) 〉
Weigh up 0.50% (quality) NaCl aqueous solution of 184.3g, be put in the 250ml plastic containers with cover.Then, in order to obtain solvable amount, 1.00g water-absorbing resin or water-retaining agent are added in this aqueous solution, the mixture of using for example magnetic stirrer (with the 250-350rpm rotating speed) stirring to obtain again reaches 16 hours, the length of its agitating vane is 40mm, diameter be 8mm (as A type agitating vane, Sougo RiKagaKuGlass SeisaKusho Co., the Ltd product), the about deeply 2cm of consequent whirlpool.Extracting solution with a filter paper filtering (produce trade(brand)name by ADVANTEC Toyo Kaisha Ltd.: (qualitative filter paper, JISP3801, No.2), thick 0.26mm, minimum-value aperture 5 μ m), take out 50.0g filtrate as measuring solution.
Subsequently, to be titrated to pH value with the 0.1N NaOH aqueous solution be 10 to the salt brine solution that does not contain water-absorbing resin or water-retaining agent.Afterwards, to be titrated to pH value with the 0.1N HCL aqueous solution be 2.7 to salt brine solution.Titration can obtain blank titration degree ([bNaOH] mL, [bHCl] mL).
Can do same titration with measuring solution, obtain titre ([NaOH] mL, [HCl] mL).
After this, calculate the solvable amount of water-absorbing resin or water-retaining agent from the titre of blank titration degree and measurement solution.For example, for the water-absorbing resin or water-retaining agent that contain known quantity vinylformic acid and salt thereof (sodium acrylate), monomeric molecular-weight average of available vinylformic acid (sodium acrylate) and above-mentioned titre are calculated solvable amount from following formula (6.1).
For the water-absorbing resin or water-retaining agent of content the unknown, obtain neutralization ratio with the titre value of measuring according to following formula (6.2) earlier, calculate monomeric molecular-weight average.Calculate the solvable amount of water-absorbing resin or water-retaining agent with following formula (6.1) with the molecular-weight average of calculating like this.
Figure A20048000010400242
The Performance Evaluation of<absorbent item (utilizes little chubby child's doll Kewpie Doll Test 〉
Produce the suction articles for use that are used for Performance Evaluation by the following method.At first, general<example〉and following<comparative example in the water-absorbing resin (water-retaining agent) of 50 parts (weight) obtaining make dry blending with the comminuted wood pulp of 50 parts of weight with stirrer.This mixture is pressed into 120mm * 400mm thin plate with fed batch formula air press molding machine on 400 order wire screens (size of mesh 38 μ m).2kg/cm subsequently pressurizes on this thin plate 2(196.14KPa) 5 seconds.The result obtains the about 0.047g/cm of ground mass 2Absorbing material.
Then, will be with the base plate that the part rivel is arranged (waterproof plate) of opacity polypropylene manufacturing, absorbing material, and it is superimposed with double-sided tape to press this order by the top board (porous disc) that the polypropylene of porous is made, connect adhesive tape with two subsequently and be attached on this superimposed material, form absorbent item (being paper nappy).
This absorbent item is covered the Doll at Kewpie On the doll (high 55cm, heavy 5kg), and with KewpieDoll Face and transfer.Subsequently, at absorbent item and Kewpie Doll Pipe of middle insertion, solution (S0-S7) is delivered to the zone that expectation can be run into urine by this pipe.At this moment, sent into 50ml every 20 minutes after solution is heated to 37 ℃, deliver to always that absorbent item can not absorb again and spillage solution till, measure the solution total amount of sending into up to now.
Every kind of solution weight repetition measurement of S0-S7 four times is obtained four observed values and is got mean value, and this mean value be can be regarded as solution (S0-S7) value of being absorbed (QP absorbed dose (g)).Believe in the assessment that absorbed dose is big more, the absorbent item performance is good more.
After the solution supply, seal with adhesive tape on absorbent item four limits, with the excision of absorbent item top layer, so can watch absorbent item from supply solution one side, then, in order to obtain diffusivity (%), measures a part of absorbing material of absorbent solution from supply side.The calculating of diffusivity (%) is divided by the absorbing material total area with absorbing material exhausted area.
As mentioned above, measure 4 solution total amounts and calculate the QP absorbed dose.Therefore, obtain the diffusivity (%) of each measurement, with the mean value of 4 diffusivitys (%) QP diffusivity (%) as every kind of solution of S0-S7.It is believed that in the assessment that the QP diffusivity is high more, the absorbent item performance is good more.
<gel infiltration index/GPI 〉
Use international disclosed WO9522356 (corresponding to the salt brine solution water conservancy diversion experimental installation of explanation in the day patent publication No. 509591/1977 of the present disclosure (ToKuhyouhei 9-509591), and with ion exchanged water and the S0-S7NaCl aqueous solution as swelling solution and percolating solution, obtain gel infiltration index (GPI).
At length, measuring apparatus shown in Figure 1 can be used for measuring GPI.This measuring apparatus comprises: dress percolating solution 33 in the container 31; Groove 41, solution are supplied with the gel coat of being made up of the water-absorbing resin of swelling or water-retaining agent 44 therein; Collector 48 is used to collect the solution that passes gel; Reach table scale 49, be used for the weight of the solution of measurement collection.
Insert a Glass tubing 32 in the container 31.The position of the lower end of Glass tubing 32 makes the penetrating fluid of supplying with groove 41 remain on the above 5cm in gel coat bottom surface.Penetrating fluid in the container 31 is supplied with groove 41 by the L type pipe that valve 35 is housed.
Groove 41 is reservoirs, and penetrating fluid sees through therein and comprises the water-absorbing resin of swelling or the gel coat 44 of water-retaining agent.The internal diameter 6cm of groove 41 has a Stainless Steel Cloth 42 (400 orders, mesh size 38 μ m) in groove 41 bottom surfaces.Groove 41 also comprises a piston 46, can press to the surface of gel coat 44.Piston 46 has some holes of passing its lower part 47.The size in hole 47 can be passed through penetrating fluid.The lower part of piston 46 has glass filter 45, and its outstanding rate of permeation can prevent water-absorbing resin or water-retaining agent, or its swelling gel enters in the hole 47.Groove 41 rests on the pallet.Pallet contacts with groove and comprises stainless wire mesh 43, and therefore, percolating solution can freely pass through pallet.
Collection container 48 is for collecting the percolating solution usefulness, is held in place on the platform balance 49 of wire cloth 43 belows of support slot 41.This platform balance is measured the weight of the penetrating fluid of being collected by collection container 48.
Measuring apparatus is measured the method for GPI and is stated as follows.Filling water-absorbing resin or water-retaining agent (0.900g) are to the neat face height of groove 41.In groove 41, water-absorbing resin or water-retaining agent are with swelling liquid swelling 60 minutes under 0.3psi (2.07KPa) or 0.7psi (4.83KPa) predetermined pressure.Then, the height of record gel coat 44, gel coat is the water-absorbing resin or the water-retaining agent of swelling and gel.After this, penetrating fluid under the constant hydrostatic pressure from container drain and under same pressure swelling, thereby penetrate gel coat 44.Notice that the swelling liquid that penetrating fluid used herein and swelling are used is same solution.For example, when with S0 solution swelling, just with S0 solution as penetrating fluid.
Secondly, the total amount (g) of the penetrating fluid by gel coat 44 curve (Fig. 1) that write down once and drew in time in per 20 seconds in the clock time at 10 minutes with computer and platform balance.Penetrating fluid by gel coat 44 (most of penetrating fluid between blob of viscose by gel coat 44), its flow rate Fs (t) be to pass through the weight (g) of penetrating fluid of gel coat 44 in the given time divided by this scheduled time (s) (g/s).
Gel infiltration index (GPI) calculates with following formula (7), a data (flow rate Fs (t)) that the percolating solution total amount that needs utilization to write down in the clock time at 10 minutes obtains.In 10 fens clock times that begin from ts, hydrostatic pressure will be stablized, thereby obtains stable flow rate.
Figure A20048000010400261
In the formula (7), the evaluation of the primary rate Fs (t=0) of expression by gel coat 44, the curve of the flow rate of can drawing Fs (t) and time t (behind the ts in 10 minutes) and with method of least squares with curve extrapolation, the value when obtaining t=0.In the formula (7), L 0Be gel coat thickness (cm), ρ is NaCl solution density (g/cm 3), A is gel coat top surface area (28.27cm in the groove 41 2), Δ P is the hydrostatic pressure (4920dyne/cm that acts on the gel coat 2).The unit of GPI is 10 -7* cm 3* S * g -1
<reference example 1 〉
The preparation of solution (1) is that the polyethyleneglycol diacrylate of 14.6g (add oxyethane average mol be 8) is dissolved in the sodium acrylate aqueous solution of 4500g (39% weight memo bulk concentration), through caustic soda and the vinylformic acid that includes the protoanemonin that can not survey (ND) amount (less than 1ppm) and the p methoxy phenol (with respect to vinylformic acid weight) of furfural and 50ppm) the neutralization ratio of the mixed solution sodium acrylate aqueous solution one glass neutralize 71.3% (mole).
Solution (1) deoxygenation 30 minutes in nitrogen atmosphere enters reactor again, and reactor is the double-arm kneader of 10L stainless steel of two sigma type paddles and a chuck to be arranged and be added with lid.With the original air of nitrogen replacement, the temperature that keeps solution (1) simultaneously is 30 ℃ in the reflecting device.In addition, the aqueous solution and the stirring that add 2.46g Sodium Persulfate and 0.10g L-xitix in the solution (1).Begin polyreaction after about one minute, under 30-90 ℃, reacted 60 minutes, produce hydrogel cross-linked polymer (1).
Hydrogel cross-linked polymer (1) diameter that obtains is about 5mm..Several pieces hydrogel cross-linked polymers (1) are sprayed at (aperture 300 μ m) on the 50 purpose screen clothes, and use 150 ℃ of hot air dries 90 minutes thereon.Hydrogel cross-linked polymer (1) after the oven dry is pulverized with the oscillatory type masher and is classified and blending by 20 eye mesh screens (aperture 850 μ m).Its product is water absorbing resin particle in irregular shape (a).
<reference example 2 〉
The preparation of solution (2) is that the polyethyleneglycol diacrylate of 11.7g (add oxyethane average mol be 8) is dissolved in the sodium acrylate aqueous solution of 5200g (39% weight memo bulk concentration), and this aqueous solution is by caustic soda and the vinylformic acid of the protoanemonin that includes immeasurability (less than 1ppm) and the p methoxy phenol of furfural and 50ppm (with respect to vinylformic acid weight)) mix that to reach neutralization ratio be 60.0% (mole).
Solution (2) is followed deoxygenation and is filled in the reactor, and reflecting device adds lid on the double-arm kneader of 10L stainless steel (two sigma type paddles and a chuck are arranged), and example 1 sees reference.With the gas in the nitrogen replacement reflecting device and keep 30 ℃ temperature.After this, the aqueous solution and the stirring that add 2.88g Sodium Persulfate and 0.10g L-xitix in the solution (2).Begin polyreaction after about one minute, be reflected at and carried out under 30-90 ℃ 60 minutes, produce hydrogel cross-linked polymer (2) (being diameter 5mm particle).Product is pressed reference example 1 described oven dry.
After the oven dry, hydrogel cross-linked polymer (2) is pulverized with the oscillatory type masher and is classified and blending by 20 eye mesh screens (aperture 850 μ m).Product is water absorbing resin particle in irregular shape (b).
<reference example 3 〉
The preparation of solution (3) is that the polyethyleneglycol diacrylate of 58.5g (add oxyethane average mol be 8) is dissolved in the aqueous solution of sodium acrylate (monomer density (weight) is 37%) of 5650g, this aqueous solution by with caustic soda with in the neutralization ratio that mixes neutralize 75.0% (mole) of the p methoxy phenol (with respect to vinylformic acid weight) of the vinylformic acid that contains protoanemonin that measurement do not go out and furfural and 50ppm is arranged.
In the injecting reactor, reflecting device adds lid and forms on the double-arm kneader of 10L stainless steel (two sigma type paddles and a chuck are housed), of reference example 1,2 after solution (3) deoxygenation.With in the nitrogen replacement reflecting device and keep 30 ℃ temperature.After this, add 2.88g Sodium Persulfate and 0.10g L-xitix in the solution (3), stir simultaneously.Begin polyreaction after about one minute, be reflected at and carried out under 30-90 ℃ 60 minutes, obtain hydrogel cross-linked polymer (3) (being diameter 5mm particle).Product is pressed reference example 1 and 2 described oven dry.
After the oven dry, hydrogel cross-linked polymer (3) is pulverized with the oscillatory type masher and is classified and blending by 20 eye mesh screens (aperture 850 μ m).Product is water absorbing resin particle in irregular shape (c).
<reference example 4 〉
The preparation of solution (4) is that the polyethyleneglycol diacrylate of 4.4g (the oxyethane average mol of interpolation is 8) is dissolved in the aqueous solution of sodium acrylate (monomer concentration is 33% weight) of 5330g, and this aqueous solution is by with the p methoxy phenol (with respect to vinylformic acid weight) of caustic soda with vinylformic acid that contains immeasurability protoanemonin and furfural and 50ppm) the neutralization ratio that mixes neutralize 75.0% (mole).
In solution (4) deoxygenation and the injecting reactor, reflecting device is added a cover on the double-arm kneader of 10L stainless steel (two sigma type paddles and a chuck are arranged) and formed, and is of reference example 1,2 and 3.In the nitrogen replacement reflecting device, keep 30 ℃ of temperature.After this, in solution (4), add the aqueous solution of 2.88g Sodium Persulfate and 0.10g L-xitix, stir simultaneously.Begin polyreaction after about one minute, be reflected at and carried out under 30-90 ℃ 60 minutes, obtain hydrogel cross-linked polymer (4) (being diameter 5mm droplet).Product is pressed reference example 1,2,3 oven dry.
After the oven dry, hydrogel cross-linked polymer (4) is pulverized with the oscillatory type masher and is classified and blending by 20 eye mesh screens (aperture 850 μ m).Product is water absorbing resin particle in irregular shape (d).
<reference example 5 〉
The preparation of solution (5) is that the polyethyleneglycol diacrylate of 63.0g (the oxyethane average mol of interpolation is 8) is dissolved in the aqueous solution (monomer concentration 37% weight) of the sodium acrylate of 5650g, this aqueous solution is by mixing the neutralization ratio of neutralize 60.0% (mole) with caustic soda with the p methoxy phenol (with respect to vinylformic acid weight) of vinylformic acid that contains a small amount of protoanemonin and furfural and 50ppm.
Solution (5) is pressed reference example 1-4 deoxygenation, and in the injecting reactor, reflecting device is described with reference example 1-4 to be to add lid on the double-arm kneader of a 10L stainless steel (two sigma type paddles and a chuck are arranged) to form, with 30 ℃ of homothermic nitrogen replacement reflecting device inside.After this, in solution (5), add the aqueous solution of 2.88g Sodium Persulfate and 0.10g L-xitix, stir simultaneously.Begin polyreaction after about one minute, be reflected at and carried out under 30-90 ℃ 60 minutes, obtain hydrogel cross-linked polymer (5) (being diameter 5mm droplet), press the described oven dry of reference example 1-4.
After the oven dry, hydrogel cross-linked polymer (5) is pulverized with the oscillatory type masher and is classified and blending by 20 eye mesh screens (aperture 850 μ m).Product is water absorbing resin particle in irregular shape (e).
<reference example 6 〉
Water absorbing resin particle in irregular shape (f) is pressed the method manufacturing of reference example 4, but uses the polyethyleneglycol diacrylate (the oxyethane average mol of interpolation is 8) of 88.2g.
<example 1 〉
100 parts of the water-absorbing resin that reference example 1 obtains (a) with contain 0.5 part of propylene glycol, 0.3 part 1, the surface crosslinking agent of 4-butyleneglycol and 3 parts of water mixes mutually.This mixture postheating to 220 ℃ is incubated 90 minutes, obtains comprising the water-retaining agent (1) of surface-treated water-absorbing resin.
<example 2 〉
Press the method in the example 1, the water-absorbing resin (b) that obtains with reference example 2 replaces water-absorbing resin (a), obtains comprising the water-retaining agent (2) of surface-treated water-absorbing resin.
<example 3 〉
At Le Dige the mixing machine ((Gebr of Le Dige Harmann Berstorff, Maschinenbau GmbH, Lodige Maschinenbau, GmbH) product, model M5R) inject 0.3 part the hydrophilic silicon dioxide (with respect to the quality of 100 parts of water-absorbing resins (c)) that is obtained by reference example 3 in, the water-retaining agent of generation has comprised the surface-treated water-absorbing resin in (3).
<example 4 〉
Press the method in the example 3, replace hydrophilic silicon dioxide, obtain containing the water-retaining agent (4) of surface-treated water-absorbing resin with calcium stearate.
<example 5 〉
The water-absorbing resin (e) that obtains with reference example 5 with comprise 0.5 part of propylene glycol, 0.3 part 1, the surface crosslinking agent of 4-butyleneglycol and 3 parts of water mixes.This mixture postheating to 220 ℃ is incubated 40 minutes, and the water-retaining agent that obtains (5) comprises the surface-treated water-absorbing resin.
<example 6 〉
Press the method in the example 5, replace water-absorbing resin (e) with the water-absorbing resin (f) that obtains in the reference example 6, the water-retaining agent that obtains (6) comprises the surface-treated water-absorbing resin.
<comparative example 1 〉
100 parts of water-absorbing resins that obtain by reference example 1 (a) with comprise 0.5 part of propylene glycol, 0.3 part 1, the surface crosslinking agent of 4-butyleneglycol and 3 parts of water mixes mutually.This mixture postheating to 210 ℃ is incubated 40 minutes, and the comparison water-retaining agent (1) that obtains has comprised the surface-treated water-absorbing resin.
<comparative example 2 〉
100 parts of water-absorbing resins that obtain by reference example 4 (d) with comprise 0.02 part of ethylene glycol bisthioglycolate Synthesis of Oligo Ethylene Glycol, 0.3 part 1, the surface crosslinking agent of 4-butyleneglycol, 0.4 part of propylene glycol and 2 parts of water mixes mutually.195 ℃ of this mixture postheating are incubated 50 minutes, and the comparison water-retaining agent (2) that obtains has comprised the surface-treated water-absorbing resin.
<comparative example 3 〉
Except at 210 ℃ down the heating 40 minutes, the method for still pressing comparative example 3 obtains containing the comparison water-retaining agent (3) of surface-treated water-absorbing resin.
<comparative example 4 〉
The water-absorbing resin (c) that is obtained by reference example 3 heated 90 minutes down at 220 ℃, did not mix with surface crosslinking agent, can obtain comparison water-retaining agent (4).
<result 〉
Table 1 illustrates the various performances of water-absorbing resin (a)-(f), comprises to the receptivity of 0.90% (weight) NaCl aqueous solution under no pressure solvable amount (weight percent (wt) %), and size-grade distribution (weight wt%).Table 2 and 3 illustrates the receptivity under no pressure to solution S 0-S7, and wherein table 2 expression contains water-retaining agent (1)-(6) of surface-treated water-absorbing resin, and water-retaining agent (1)-(4) are compared in table 3 representative and supply water-absorbing resin (c) relatively.The receptivity (AAP) of table 4 to pressure table 7 illustrate, salt concentration absorptive index, and the average and standard deviation of salt concentration absorptive index.
Table 8 illustrates uses water-retaining agent (1) and (2) and the assessment result of the performance (QP absorbed dose) of the water-retaining agent product of water-retaining agent (1), (2), (3) relatively.Water-retaining agent (1) and comparison water-retaining agent (3) were at two different pressures (gel infiltration index under 0.3psi (2.07Kpa) and the 0.7psi (4.83KPa) when table 9 illustrated employing solution S 6 (0.7% quality (weight) the NaCl aqueous solution).Table 10 illustrates and adopts solution S 0, S3, S6, water-retaining agent during S7 (1) and the gel infiltration index of comparison water-retaining agent (3) under 0.3psi (2.07KPa).Table 11 illustrates when adopting water-retaining agent (1) and comparing water-retaining agent (1), (3), the assessment result of water-retaining agent product performance (QP absorptive index).
Table 12 and 13 illustrates the salt tolerance index of water-retaining agent (1)-(6) that contain the surface treatment water-absorbing resin.Table 12 and 13 also illustrates comparison water-retaining agent (1)-(4), and for the salt tolerance index of relatively using water-absorbing resin (c).
Table 1
Water-absorbing resin (a) Water-absorbing resin (b) Water-absorbing resin (c) Water-absorbing resin (d) Water-absorbing resin (e) Water-absorbing resin (f)
Receptivity under the no pressure (g/g) (the 0.9%NaCl aqueous solution) ??32.0 ??30.0 ??20.1 ??40.0 ??20.2 ??14.8
Solvable amount (wt, %) ??10.0 ??9.0 ??2.0 ??12.0 ??1.8 ??0.9
The size-grade distribution 500 μ m of water-absorbing resin are qualified ??94 ??96 ??96 ??93 ??96 ??94
300 μ m are qualified ??24 ??26 ??26 ??25 ??26 ??24
150 μ m are qualified ??3 ??2 ??5 ??4 ??5 ??3
106 μ m are qualified ??1 ??1 ??2 ??3 ??2 ??1
Quality mean particle size D 50 (μ m) ??350 ??340 ??340 ??350 ??340 ??350
Table 2
Receptivity under the no pressure (g/g) Water-retaining agent (1) Water-retaining agent (2) Water-retaining agent (3) Water-retaining agent (4) Water-retaining agent (5) Water-retaining agent (6)
NaCl concentration (wt, %) 0.0 ??73.8 ??68.0 ??56.8 ??58.0 ??54.5 ??36.1
??0.1 ??45.0 ??43.0 ??39.7 ??44.0 ??36.4 ??28.1
??0.2 ??36.3 ??35.0 ??33.5 ??38.0 ??30.3 ??23.2
??0.3 ??30.9 ??29.0 ??31.6 ??33.0 ??26.0 ??21.0
??0.4 ??24.7 ??24.0 ??29.8 ??30.0 ??24.5 ??19.0
??0.5 ??23.2 ??22.0 ??27.1 ??27.0 ??22.5 ??17.0
??0.7 ??20.1 ??19.0 ??24.0 ??24.0 ??20.0 ??14.5
??0.9 ??18.0 ??17.0 ??20.1 ??20.0 ??18.1 ??13.5
(wt, %) 500 μ m are qualified for the water-absorbing resin size-grade distribution ??95 ??96 ??95 ??93 ??93 ??93
300 μ m are qualified ??24 ??26 ??25 ??25 ??25 ??25
150 μ m are qualified ??2 ??3 ??4 ??4 ??4 ??4
106 μ m are qualified ??1 ??1 ??3 ??3 ??3 ??3
Mean particle size ??350 ??340 ??350 ??350 ??350 ??350
Table 3
Receptivity under the no pressure (g/g) Compare water-retaining agent (1) Compare water-retaining agent (2) Compare water-retaining agent (3) Compare water-retaining agent (4) Water-absorbing resin (c)
NaCl concentration (wt, %) 0.0 ??130.2 ??281.6 ??207.5 ??55.9 ??61.9
??0.1 ??56.4 ??111 ??82.4 ??43.2 ??44.2
??0.2 ??45.7 ??87.3 ??63.5 ??36.7 ??37.7
??0.3 ??38.7 ??69.6 ??56.3 ??33.1 ??32.9
??0.4 ??34.8 ??62 ??50.1 ??28.7 ??29.7
??0.5 ??32.8 ??57.8 ??45.0 ??27.8 ??26.4
??0.7 ??28.1 ??51.8 ??38.6 ??24.6 ??22.3
??0.9 ??28 ??47.7 ??32.0 ??21.1 ??20.1
(wt, %) 500 μ m are qualified for the water-absorbing resin size-grade distribution ??95 ??93 ??97 ??96 ??96
300 μ m are qualified ??24 ??26 ??25 ??26 ??26
150 μ m are qualified ??3 ??4 ??4 ??5 ??5
106 μ m are qualified ??2 ??2 ??3 ??3 ??2
Mean particle size ??350 ??350 ??340 ??340 ??340
Table 4
Receptivity under the pressure (g/g) Water-retaining agent (1) Water-retaining agent (2) Water-retaining agent (3) Water-retaining agent (4) Water-retaining agent (5) Water-retaining agent (6)
NaCl concentration (wt, %) 0.0 ??71.7 ??70.0 ??46.7 ??51.0 ??59.3 ??42.8
??0.1 ??40.6 ??42.0 ??36.4 ??38.0 ??35.3 ??29.4
??0.2 ??32.4 ??33.0 ??29.4 ??30.0 ??29.6 ??25.8
??0.3 ??28.5 ??30.0 ??27.7 ??29.0 ??26.0 ??22.0
??0.4 ??25.4 ??25.8 ??24.7 ??25.2 ??23.5 ??21.0
??0.5 ??23.9 ??24.0 ??23.8 ??24.1 ??23.2 ??20.6
??0.7 ??21.5 ??22.0 ??21.3 ??21.4 ??19.8 ??18.3
??0.9 ??18.6 ??19.0 ??18.0 ??18.3 ??19.3 ??17.8
Table 5
Receptivity under the pressure (g/g) Compare water-retaining agent (1) Compare water-retaining agent (2) Compare water-retaining agent (3) Compare water-retaining agent (4) Water-absorbing resin (c)
NaCl concentration (wt, %) 0.0 ??66.4 ??12.1 ??39.8 ??31.5 ??19.1
??0.1 ??45.2 ??10.3 ??43.9 ??24.1 ??23.9
??0.2 ??37.7 ??9.4 ??38.0 ??20.5 ??19.8
??0.3 ??33.2 ??9.4 ??33.2 ??20.9 ??19.2
??0.4 ??30.9 ??8.6 ??29.0 ??20.4 ??18.1
??0.5 ??28.7 ??8.4 ??28.3 ??20.7 ??17.0
??0.7 ??25.8 ??8.3 ??26.1 ??18.1 ??17.0
??0.9 ??24.0 ??7.6 ??25.0 ??18.3 ??17.0
Table 6
The salt concentration absorptive index Water-retaining agent (1) Water-retaining agent (2) Water-retaining agent (3) Water-retaining agent (4) Water-retaining agent (5) Water-retaining agent (6)
NaCl concentration (wt, %) 0.0 ??0.97 ??1.03 ??0.82 ??0.88 ??1.09 ??1.19
??0.1 ??0.90 ??0.98 ??0.92 ??0.86 ??0.97 ??1.05
??0.2 ??0.89 ??0.94 ??0.88 ??0.79 ??0.98 ??1.11
??0.3 ??0.92 ??1.03 ??0.88 ??0.88 ??1.00 ??1.05
??0.4 ??1.03 ??1.08 ??0.83 ??0.84 ??0.96 ??1.11
??0.5 ??1.03 ??1.09 ??0.88 ??0.89 ??1.03 ??1.21
??0.7 ??1.07 ??1.16 ??0.89 ??0.89 ??0.99 ??1.26
??0.9 ??1.03 ??1.12 ??0.90 ??0.92 ??1.07 ??1.32
The mean value of salt concentration absorptive index ??0.98 ??1.05 ??0.87 ??0.87 ??1.01 ??1.16
The standard deviation of salt concentration absorptive index ??0.0041 ??0.0045 ??0.0009 ??0.0013 ??0.0477 ??0.0776
Table 7
The salt concentration absorptive index Compare water-retaining agent (1) Compare water-retaining agent (2) Compare water-retaining agent (3) Compare water-retaining agent (4) Water-absorbing resin (c)
NaCl concentration (wt, %) 0.0 ??0.51 ??0.04 ??0.19 ??0.56 ??0.31
??0.1 ??0.80 ??0.09 ??0.53 ??0.56 ??0.54
??0.2 ??0.82 ??0.11 ??0.60 ??0.56 ??0.53
??0.3 ??0.86 ??0.14 ??0.59 ??0.63 ??0.58
??0.4 ??0.89 ??0.14 ??0.58 ??0.71 ??0.61
??0.5 ??0.88 ??0.15 ??0.63 ??0.74 ??0.64
??0.7 ??0.92 ??0.16 ??0.68 ??0.74 ??0.76
??0.9 ??0.86 ??0.16 ??0.78 ??0.87 ??0.85
The mean value of salt concentration absorptive index ??0.82 ??0.12 ??0.57 ??0.67 ??0.60
The standard deviation of salt concentration absorptive index ??0.0146 ??0.0014 ??0.0256 ??0.0110 ??0.0229
Table 8
QP absorbs total amount (g) Water-retaining agent (1) Water-retaining agent (2) Compare water-retaining agent (1) Compare water-retaining agent (2) Compare water-retaining agent (3)
The solution S 0 that absorbs Concentration (wt, %) 0.0 ??300 ??300 ??225 ??90 ??90
??S1 ??0.1 ??290 ??300 ??230 ??100 ??100
??S2 ??0.2 ??285 ??290 ??230 ??100 ??230
??S3 ??0.3 ??280 ??285 ??235 ??90 ??235
??S4 ??0.4 ??275 ??270 ??240 ??90 ??240
??S5 ??0.5 ??265 ??270 ??240 ??90 ??240
??S6 ??0.7 ??250 ??260 ??250 ??80 ??250
??S7 ??0.9 ??260 ??250 ??270 ??80 ??270
Absorb total amount ??2205 ??2225 ??1920 ??720 ??1655
Table 9
Pressure (KPa) GPI (10 in the 0.7%NaCl aqueous solution -7×cm 3×S×g -1)
Water-retaining agent (1) Compare water-retaining agent (1)
??2.07 ??4.83 ?210 ?30 ??30 ??4
Table 10
2.07KPa under GPI (10 -7×cm 3×S×g -1) Water-retaining agent (1) Compare water-retaining agent (1)
The solution that absorbs Concentration (wt, %)
??S0 ??0.0 ??22 ?1
??S3 ??0.3 ??191 ?21
??S6 ??0.7 ??210 ?30
??S7 ??0.9 ??242 ?30
Table 11
QP diffusivity (%) Water-retaining agent (1) Compare water-retaining agent (1) Compare water-retaining agent (3)
The solution that absorbs HCL concentration (wt, %)
??S0 ??0.0 ?85 ?57 ?26
??S3 ??0.3 ?83 ?58 ?29
??S6 ??0.7 ?67 ?60 ?58
??S7 ??0.9 ?64 ?60 ?60
Table 12
Salt tolerance index Water-retaining agent (1) Water-retaining agent (2) Water-retaining agent (3) Water-retaining agent (4) Water-retaining agent (5) Water-retaining agent (6)
NaCl concentration (wt, %)
??0.1 ??0.61 ??0.63 ??0.70 ??0.76 ??0.67 ??0.78
??0.2 ??0.49 ??0.51 ??0.59 ??0.66 ??0.56 ??0.64
??0.3 ??0.42 ??0.43 ??0.56 ??0.57 ??0.48 ??0.58
??0.4 ??0.33 ??0.35 ??0.52 ??0.52 ??0.45 ??0.53
??0.5 ??0.31 ??0.32 ??0.48 ??0.47 ??0.41 ??0.47
??0.7 ??0.27 ??0.28 ??0.42 ??0.41 ??0.37 ??0.40
??0.9 ??0.24 ??0.25 ??0.35 ??0.34 ??0.33 ??0.37
Table 13
Salt tolerance index Compare water-retaining agent (1) Compare water-retaining agent (2) Compare water-retaining agent (3) Compare water-retaining agent (4) Water-absorbing resin (c)
NaCl concentration (wt.%)
??0.1 ??0.43 ??0.39 ??0.40 ??0.77 ??0.71
??0.2 ??0.35 ??0.31 ??0.31 ??0.66 ??0.61
??0.3 ??0.30 ??0.25 ??0.27 ??0.59 ??0.53
??0.4 ??0.27 ??0.22 ??0.24 ??0.51 ??0.48
??0.5 ??0.25 ??0.21 ??0.22 ??0.50 ??0.43
??0.7 ??0.22 ??0.18 ??0.19 ??0.44 ??0.36
??0.9 ??0.22 ??0.17 ??0.15 ??0.38 ??0.32
Above-mentioned the present invention obviously can have a lot of variations, and such variation can not be considered as departing from the spirit and scope of the invention, and all such variations it will be apparent to those skilled in the art that, should be included in the scope of claim of the present invention.
Industrial Applicability A
Why particulate water absorbent containing of the present invention has good performance regardless of service condition, thereby can be applicable to various fields, and such as the moisture maintenance of agricultural or gardening, industrial moisture keeps, drier, dehumidizer or construction material. Particulate water absorbent containing of the present invention is specially adapted to the amenities take paper nappy as representative and absorbs the sanitary napkin of body fluid (comprising ight soil, urine, blood).

Claims (19)

1. particulate water absorbent containing, its contained water-absorbing resin forms by water-soluble unsaturated monomer is crosslinked; Special and the particles contained granularity of water-absorbing resin shape is being not less than 106 μ m and less than the scope (106~850 μ m) of 850 μ m, its quality is no less than 90% of water-absorbing resin total mass;
Particulate water absorbent containing has the first salt concentration absorptive index, and its value is calculated by following formula (1) and is not less than 0.60 when with the ion exchanged water being the aqueous solution such as salt concentration such as grade:
(salt concentration absorptive index)=(in the receptivity of the inferior salt concentration aqueous solution of 4.83KPa pressure)
/ (receptivity of the inferior salt concentration aqueous solution of no pressure) ... (1)
Molecule is when the salt concentration aqueous solution such as particulate water absorbent containing immersion receptivity under 4.83KPa pressure after 60 minutes in the formula, and denominator is when the salt concentration aqueous solution such as particulate water absorbent containing immersion receptivity under the no pressure after 60 minutes.
2. particulate water absorbent containing, its contained water-absorbing resin forms by water-soluble unsaturated monomer is crosslinked; Special and the particles contained granularity of water-absorbing resin shape is being not less than 106 μ m and less than the scope (106~850 μ m) of 850 μ m, its quality is not less than 90% of water-absorbing resin total mass;
This particulate water absorbent containing receptivity under 4.83KPa pressure after soaking 60 minutes with ion exchanged water is not less than 50g/g.
3. particulate water absorbent containing as claimed in claim 1, wherein, particulate water absorbent containing has the second salt concentration absorptive index, when etc. the salt concn aqueous solution when being 0.10% (quality) NaCl aqueous solution its value calculate with formula (1) and be not less than 0.80.
4. as claim 1 or 3 described particulate water absorbent containings, wherein, particulate water absorbent containing ought be respectively with 0.30% (quality), 0.50% (quality), 0.70% (quality) and 0.90% (quality) NaCl aqueous solution its value when waiting salt concentration aqueous solution has the 3rd by formula (1) calculating, the the four, the five and the 6th salt concentration absorptive index; And wherein, the three, four, five, six salt concentration absorptive indexs have at least one to be not less than 0.90.
5. particulate water absorbent containing as claimed in claim 4, wherein, particulate water absorbent containing has with the three, four, and the mean value of five, six salt concentration absorptive indexs is its average salt concentration absorptive index, and its value is not less than 0.90.
6. particulate water absorbent containing as claimed in claim 5, wherein, the standard deviation of average salt concentration absorptive index is 0-0.100.
7. as each described particulate water absorbent containing of claim 1 to 6, wherein, particulate water absorbent containing has first salt tolerance index, and its value is calculated by following formula (2) and is not less than 0.40 when with 0.10% (quality) NaCl aqueous solution serving as the aqueous solution such as salt concentration such as grade:
(salt tolerance index)=(receptivity of the inferior salt concentration aqueous solution of no pressure)/
(receptivity of ion exchanged water under the no pressure) ... (2)
Molecule is the salt concentration aqueous solution such as particulate water absorbent containing immersion receptivity under the no pressure after 60 minutes in the formula, and denominator to be particulate water absorbent containing soak ion exchanged water receptivity under the no pressure after 60 minutes.
8. as each described particulate water absorbent containing of claim 1-7, wherein, particulate water absorbent containing soak 0.90% (quality) NaCl aqueous solution after 60 minutes the water-retaining capacity under the no pressure be 10-27g/g.
9. as each described particulate water absorbent containing of claim 1-8, wherein, particulate water absorbent containing soak 0.90% (quality) NaCl aqueous solution after 60 minutes the water-retaining capacity under 4.83KPa pressure be 10-27g/g.
10. as each described particulate water absorbent containing of claim 1-9, wherein, particulate water absorbent containing also comprises water-fast particulate.
11. as each described particulate water absorbent containing of claim 1-10, wherein, particulate water absorbent containing has the gel infiltration index, it is not less than 15 to the value of ion exchanged water under 2.07KPa pressure.
12. as each described particulate water absorbent containing of claim 1-11, wherein, particulate water absorbent containing is not less than 50 for the gel infiltration index of 0.30% (quality) NaCl aqueous solution under 2.07KPa pressure.
13. as each described particulate water absorbent containing of claim 1-12, wherein, particulate water absorbent containing is not less than 15 for the gel infiltration index of 0.70% (quality) NaCl aqueous solution under 4.83KPa pressure.
14. as each described particulate water absorbent containing of claim 1-13, wherein, water-absorbing resin can be by surface modification treatment.
15. particulate water absorbent containing as claimed in claim 14, wherein, surface modification treatment makes water-absorbing resin surface-crosslinked.
16. as each described particulate water absorbent containing of claim 1-15, wherein, granular water-absorbent resin contains carboxyl.
17. each described particulate water absorbent containing of claim 1-16, wherein, water-soluble unsaturated monomer comprises vinylformic acid and/or acrylate.
18. a sanitary product that is used for absorbed body fluid, it comprises each particulate water absorbent containing of claim 1-17.
19. sanitary product as claimed in claim 18 also comprises absorption layer, its sandwich layer density is being not less than 0.3 to the scope (0.3-1.0) that is not more than 1.0 as calculating by following formula (3):
(sandwich layer density)=(particulate water absorbent containing quality)/(particulate water absorbent containing quality+mass of fibre material) ... (3).
CNB2004800001047A 2003-02-10 2004-02-09 Particulate water absorbent containing water absorbent resin as a main component Expired - Lifetime CN100482339C (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102844340A (en) * 2010-02-08 2012-12-26 Lg化学株式会社 Absorbent resin, the surface of which is modified with a cationic polymer compound
CN104277404A (en) * 2007-02-09 2015-01-14 赢创德固赛有限公司 Water-absorbing polymer structure having great ammonia-binding capacity
CN105848776A (en) * 2013-12-20 2016-08-10 株式会社日本触媒 Polyacrylic acid (salt) water absorbent, and method for producing same
CN110983753A (en) * 2019-12-13 2020-04-10 江阴开源非织造布制品有限公司 Antibacterial hydrophilic non-woven fabric modifier and preparation method thereof

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104277404A (en) * 2007-02-09 2015-01-14 赢创德固赛有限公司 Water-absorbing polymer structure having great ammonia-binding capacity
CN102844340A (en) * 2010-02-08 2012-12-26 Lg化学株式会社 Absorbent resin, the surface of which is modified with a cationic polymer compound
CN105848776A (en) * 2013-12-20 2016-08-10 株式会社日本触媒 Polyacrylic acid (salt) water absorbent, and method for producing same
CN105848776B (en) * 2013-12-20 2019-09-03 株式会社日本触媒 Polyacrylic acid (salt) is water absorbing agent and its manufacturing method
CN110983753A (en) * 2019-12-13 2020-04-10 江阴开源非织造布制品有限公司 Antibacterial hydrophilic non-woven fabric modifier and preparation method thereof

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