CN101410177B - Water absorbing agent, water absorbent core using the agent, and manufacturing method for water absorbing agent - Google Patents

Water absorbing agent, water absorbent core using the agent, and manufacturing method for water absorbing agent Download PDF

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CN101410177B
CN101410177B CN2007800109479A CN200780010947A CN101410177B CN 101410177 B CN101410177 B CN 101410177B CN 2007800109479 A CN2007800109479 A CN 2007800109479A CN 200780010947 A CN200780010947 A CN 200780010947A CN 101410177 B CN101410177 B CN 101410177B
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water absorbing
water
absorbing agent
particle
resin particle
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CN101410177A (en
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鸟井一司
柴田浩史
木村一树
中岛康久
井村元洋
植田裕子
和田克之
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Nippon Shokubai Co Ltd
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Nippon Shokubai Co Ltd
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Priority claimed from PCT/JP2007/056527 external-priority patent/WO2007116777A1/en
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Abstract

A water absorbing agent of the present invention has an internal crosslinking structure obtained by polymerization of a water-soluble unsaturated monomer. The agent satisfies conditions (a) to (d): (a) the agent contains water-insoluble inorganic particles at an amount of from 10 ppm to 1,900 ppm inclusive; (b) the agent contains 5 mass % or less particles which have such a size that they can pass through a sieve having a mesh opening size of 150 mu m; (c) the agent has an absorbency against a pressure of 4.83 kPa (AAP) of 18 g/g or more; and (d) the water-insoluble inorganic particles reside on a surface of the water absorbing resin or near the surface.

Description

Water absorbing agent, the water absorbent core that uses said water absorbing agent and the method for preparing water absorbing agent
Technical field
The present invention relates to water absorbing agent, the water absorbent core that uses said water absorbing agent and the method for preparing water absorbing agent.Particularly, the present invention relates to be applicable to disposable diaper, sanitary napkin, be called water absorbing agent, the water absorbent core of incontinence protection and other cleaning/hygienic material and the method for preparing said water absorbing agent.
Background technology
Contain such as the water absorbent core of the hydrophilic fibre of paper oar and water absorbing resin particle and be widely used usually so that can absorb body fluid such as the cleaning/hygienic material of disposable diaper, sanitary napkin and incontinence protection.Water absorbent core is used in such as the cleaning/hygienic material of disposable diaper, sanitary napkin and incontinence protection to absorb body fluid.
For better workability, there is the demand of the thickness that reduces these cleaning/hygienic materials recently.Therefore, hydrophilic fibers that the bulk density that reduces of usage ratio is low relatively and ratio increase have good water imbibition and the high relatively water absorbing resin particle of bulk density prepares water absorbent core.Therefore, use the relative quantity of the water absorbing resin particle in the water absorbent core sheet to obtain increase, this so that reduced the thickness of cleaning/hygienic material and do not damaged water imbibition and other physical characteristic.
Can reduce the ratio of hydrophilic fibers, but requirement can not further be lower than minimum amount.In order further to reduce the thickness of cleaning/hygienic material, need improve the physical characteristic of water absorbing resin particle.The example of this type of physical characteristic of water absorbing resin particle comprises water imbibition, fixed height absorption ability, quality average particle size particle size and liquid diffusion rate under centrifugal water holding capacity, salt solution water conservancy diversion rate (saline flow conductivity), the pressure.These physical characteristics of water absorbing resin particle need in predetermined scope or be excellent in actual use.
For example, in containing the diaper with cleaning/hygienic material of water absorbing resin particle at high proportion, water absorbing resin particle absorbs water and also is transformed into gel or similar state.It can cause a kind of phenomenon that is called gel blockage (gel blocking).The liquid that this phenomenon has reduced cleaning/hygienic material spreads when managing salt solution as test solution; The absorption bulbs of pressure that said water-absorbing resin appears are 10; 000Pa or lower, the absorption bulbs of pressure that said water-absorbing resin appears after beginning to absorb water 300 seconds are 80,000Pa or higher.Said water absorbent core expection obtains excellent diffusivity and the infiltration of low-level liquid.
Patent documentation 8 discloses the technology of a kind of three-dimensional sept of use (3D spacers) preparation water-absorbing resin.
Patent documentation 9 discloses a kind of particulate water-absorbing agent that contains water absorbing resin particle and permeability for liquids modifying agent.Monomer through polymerization (crosslinked) acrylic acid and/or its salt and make that the surface of the irregular pulverizing particulate of gained is further crosslinked to prepare said particle.Said water absorbing agent is expected at physical characteristic: capillary attraction and permeability for liquids aspect are all excellent.
Patent documentation 10 discloses a kind of water-absorbent resin composition, and said composition contains the monomer that has carboxyl and is used to improve deodorization functions and mobile aerosil.
Patent documentation 11 discloses a kind of technology of adding permeability for liquids modifying agent to water-absorbing resin with the preparation water-absorbing resin.
[patent documentation 1]: japanese unexamined patent publication 56-133028/1981 (spy opens clear 56-133028, and on October 17th, 1981 published)
[patent documentation 2]: japanese unexamined patent publication 64-4653/1989 (spy opens clear 64-4653, and on January 9th, 1989 published)
[patent documentation 3]: Japan Patent 3169133, specification (registration on March 16 calendar year 2001)
[patent documentation 4]: japanese unexamined patent publication 9-136966/1997 (spy opens flat 9-136966, and on May 27th, 1997 published)
[patent documentation 5]: japanese unexamined patent publication (spy opens) 2000-93792 (publication on April 4th, 2000)
[patent documentation 6]: japanese unexamined patent publication (spy opens) 2003-88551 (publication on March 25th, 2003)
[patent documentation 7]: japanese unexamined patent publication (spy opens) 2003-88553 (publication on March 25th, 2003)
[patent documentation 8]: U.S.'s publication application 2002/0128618, specification (September 12 calendar year 2001)
[patent documentation 9]: japanese unexamined patent publication (spy opens) 2004-261797 (publication on September 24th, 2004)
[patent documentation 10]: PCT application japanese publication translation (special table) 2003-500490 (publication on January 7th, 2003)
[patent documentation 11]: according to the international application (on August 19th, 2004) of PCT WO2004/69915 announcement
Summary of the invention
Above-mentioned listed routine techniques has following problems: it can not obtain as the water absorbing agent of the essential physical characteristic of water-absorbing resin or can not when preparing water-absorbing resin, produce limited dust.
Particularly, in the practical application of water-absorbing resin, require water-absorbing resin to present good physical characteristic (water imbibition, fixed height absorption ability, quality average particle size particle size, liquid diffusivity etc. under centrifugal water holding capacity, salt solution water conservancy diversion rate, the pressure).Up to now, the technology of routine fails to obtain enough values of these physical characteristics.A factor of failing to obtain above-mentioned effect is the choice between centrifugal water holding capacity and the salt solution water conservancy diversion rate, and it all is important physical characteristic for water-absorbing resin: if one of said physical characteristic is improved, another physical characteristic is just impaired.The value that two kinds of physical characteristics all obtain is difficult.
In addition, in the technology of routine, if add inorganic particulate to water-absorbing resin, the new problem of dust can take place to be produced by said inorganic particulate.Said dust can be able to reduce the production efficiency of water-absorbing resin, makes the physical characteristic degradation of water-absorbing resin, or causes the worry of safety/health.Especially, when in water-absorbing resin, using 0.2 quality % or more inorganic particulate, may produce dust because the inorganic particulate that uses is more than needed relatively.
The present invention who visualizes based on these common problems has following purpose: a kind of water absorbing agent and water absorbent core that demonstrates the excellent physical characteristic is provided, and it can not produce dust, and a kind of method for preparing said water absorbing agent.
In order to solve said problem, the real water absorbing agent of the present invention is characterised in that it contains the water absorbing resin particle with internal crosslinking structure through the polymerization acquisition of water-soluble unsaturated monomer.The characteristic of said water absorbing agent is that also it satisfies following condition (a) to (d):
(a) the water absorbing agent amount is from 10ppm to 1, the water-insoluble inorganic particle of 900ppm (containing);
(b) water absorbing agent contains 5 quality % or lower and has the particle of size that can be of a size of the sieve of 150 μ m through aperture openings;
(c) under the pressure of 4.83kPa (AAP), the water absorbing capacity of water absorbing agent is 18g/g or higher; And
(d) the water-insoluble inorganic particle remains on the surface of water-absorbing resin or near surface.
Water absorbing agent of the present invention is preferably the 10ppm to 990ppm (containing) that the water-insoluble inorganic particle accounts for water absorbing agent.
Water absorbing agent of the present invention is preferably the water-insoluble inorganic particle and contains the amino that remains at least on the particle surface.
Water absorbing agent of the present invention is preferably: the water-insoluble inorganic particle is a silica; And the concentration of the residual in its surface silanol group of silica is 1.7SiOH/nm 2Or it is lower.
The salt solution water conservancy diversion rate (SFC) that water absorbing agent of the present invention is preferably water absorbing agent is 30 (10 -7Cm 3Sg -1) or higher.
It is 20g/g to 30g/g (containing) that water absorbing agent of the present invention is preferably the absorbability of water absorbing agent under 4.83kPa (AAP) pressure.
The preferred further amount of water absorbing agent of the present invention is from least three value water-soluble multivalent metal salts of 0.1 quality % to 1 quality % (containing).
It is aluminum sulfate that water absorbing agent of the present invention is preferably water-soluble multivalent metal salt.
Water absorbing agent of the present invention is preferably water absorbing resin particle and contains the particle with loose structure.
The quality average particle size particle size that water absorbing agent of the present invention is preferably water absorbing agent is 200 μ m to 500 μ m (containing), and the logstandard deviation of particle size distribution, σ ζ were 0.20 to 0.40 (containing).
It is that 0.2 (mm/sec) is to 10.0 (mm/sec) that water absorbing agent of the present invention is preferably liquid distribution speed (LDV).
Water absorbing agent of the present invention preferably has negative triboelectric charge.
Water absorbing agent of the present invention preferably contains calculates 300ppm or lower dust in mass.
Water absorbing agent of the present invention preferably contains SiO in the dust 2Amount be 50 quality % or lower dust.
Water absorbing agent of the present invention is preferably through comprising that the preparation method that water absorbing resin particle is bestowed the step of silica being mixed with it after the mechanical damage obtains.
Water absorbing agent of the present invention preferably mixes preparation method's acquisition of the step of back pneumatic transportation silica and water absorbing resin particle through being included in silica with water absorbing resin particle.
In order to solve said problem, another kind of water absorbing agent of the present invention is characterised in that it contains the water absorbing resin particle through the polymerization acquisition of water-soluble unsaturated monomer.Said water absorbing agent also satisfies following condition (A) to (D):
(A) particle near surface crosslinked have or be coated with have monohydroxy at least surface crosslinking agent;
(B) particle at least from the teeth outwards or near surface contain multivalent metal salt and water-insoluble inorganic particle;
(C) the quality average particle size particle size of water absorbing agent is 200 μ m to 500 μ m (containing); And
(D) water absorbing agent contains 5 quality % or lower and has the particle of size that can be of a size of the sieve of 150-μ m through aperture openings.
Water absorbing agent of the present invention is preferably 0.01 quality % to the 1 quality % (containing) that said multivalent metal salt accounts for water absorbing agent.
Water absorbing agent of the present invention is preferably 0.001 quality % to the 0.4 quality % (containing) that said water-insoluble inorganic particle accounts for water absorbing agent.
It is silica that water absorbing agent of the present invention is preferably said water-insoluble inorganic particle.
The centrifugal water holding capacity that water absorbing agent of the present invention is preferably said water absorbing agent be 30g/g (containing) to 50g/g (containing), salt solution water conservancy diversion rate (SFC) is 10 (10 -7Cm 3Sg -1) or higher.
Water absorbing agent of the present invention preferably contains SiO in the dust 2Amount be 50 quality % or lower dust.
In order to solve said problem, water absorbent core of the present invention is characterised in that it contains above-mentioned any water absorbing agent.
In order to solve said problem; A kind of method for preparing water absorbing agent of the present invention is that it is the method that a kind of preparation contains the water absorbing agent of the water absorbing resin particle that the polymerization through water-soluble unsaturated monomer obtains, said water absorbing resin particle the quality average particle size particle size be 200 μ m to 500 μ m (containing).The characteristic of said method is that also it comprises following continuous step: the surface crosslinking agent crosslinked or coating at the near surface of water absorbing resin particle with at least one hydroxyl is used in (1); And mix multivalent metal salt and water-insoluble inorganic particle (2) with water absorbing resin particle.
Description of drawings
Fig. 1 is a profile of having described a kind of AAP measuring instrument relevant with embodiments of the invention.
Fig. 2 is the sketch map of a kind of SFC measuring instrument relevant with embodiments of the invention.
The specific embodiment
Hereinafter will describe the present invention in detail.Yet scope of the present invention is not subject to described content.Except the described embodiment of hereinafter, can not depart from spirit of the present invention through alternate manner correction embodiment of the present invention.Note that " weight " and " quality " is respectively the synonym of " wt% " and " quality % " in the present invention.In whole specification and claims, only use " quality " and " quality % ".Numerical expression " A to B " refers to more than or equal to A and the scope that is equal to or less than B.
At first define in the following description the abbreviation that uses.CRC is the initial of " centrifugal water holding capacity ".SFC is the initial of " salt solution water conservancy diversion rate ".AAP refers to the water imbibition under the 4.83kPa pressure.FHA is the initial of " fixed height absorption ability ".LDV is the initial of " liquid diffusion rate ".D50 refers to the quality average particle size particle size.σ ζ is the logstandard deviation that particle diameter distributes.Salt solution is the aqueous solution of sodium chloride.1ppm equals 0.0001 quality %.
One embodiment of the invention are described at present.The water absorbing agent of embodiment of the present invention contains water absorbing resin particle.Said water absorbing resin particle contains water-insoluble inorganic particulate (hereinafter possibly be called " water-insoluble fine inorganic particles ").
Water absorbing resin particle
The water absorbing resin particle that is used for embodiment of the present invention is the polymer particulates (hereinafter also possibly be called " water-absorbing resin ") through the water-insoluble of the polymerization preparation of water-insoluble unsaturated monomer, imbibition, formation hydrogel.
The specific embodiment of the polymer of water-insoluble, imbibition, formation hydrogel comprises: crosslinked acrylic acid polymer (United States Patent (USP) 4,625,001 specification, the United States Patent (USP) 4 of part neutralization; 654,039 specification, United States Patent (USP) 5; 250,640 specification, United States Patent (USP) 5; 275,773 specification, the specification of European patent 456136 etc.); Crosslinked starch-acrylic acid-grafted the polymer (United States Patent (USP) 4,076,663 specification) of part neutralization; Isobutene-acid/maleic acid copolymers (United States Patent (USP) 4,389,513 specification); The saponification resultant of vinyl acetate-acrylic copolymer (United States Patent (USP) 4,124,748 specification); The hydrolysate of acrylamide polymer (copolymer) (United States Patent (USP) 3,959,569 specification); The hydrolysate of acrylonitrile polymer (United States Patent (USP) 3,935,099 specification).
The water absorbing resin particle of embodiment of the present invention is preferably the water absorbing resin particle through the cross-linked polymer that contains poly propenoic acid acrylates base of the polymerization acquisition of the monomer that contains acrylic acid and/or its salt.In embodiments of the invention; The cross-linked polymer of said poly propenoic acid acrylates base refers to through polymerization and contains 50mol% at least; Preferred 70mol% at least, the more preferably monomer of the acrylic acid of 90mol% and/or its salt and the cross-linked polymer that obtains at least.
Acidic group in the cross-linked polymer, the ratio that is preferably with 50mol% to 90mol% (containing) is neutralized, and more preferably the ratio with 60mol% to 80mol% (containing) is neutralized.The example of polyacrylate can be alkali metal salt, ammonium salt or the amine salt such as sodium, potassium or lithium.A kind of preferred embodiment is a sodium salt.Said salt can form through neutralization before the polymerization, in promptly passing through and monomer, or in polymerization process or after the polymerization, neutralizes, in promptly passing through and polymer.Selectively, said any method can and be used.
If desired, except the monomer (acrylic acid and/or its salt) of principal component, can be suitable as the poly propenoic acid acrylates base cross-linked polymer of water absorbing resin particle of the present invention through other monomer preparation of copolymerization.The concrete example of other monomer comprises: such as the unsaturated anionic monomer of methacrylic acid, maleic acid, vinyl sulfonic acid, styrene sulfonic acid, 2-(methyl) acrylamide-2-methyl propane sulfonic acid, 2-(methyl) acryloxy ethane sulfonic acid and 2-(methyl) acryloxy propane sulfonic acid; Such as acrylamide, Methacrylamide, N-ethyl (methyl) acrylamide, N-n-pro-pyl (methyl) acrylamide, N-isopropyl (methyl) acrylamide, N, the non-ionic unsaturated monomer that contains hydrophilic radical of N-dimethyl (methyl) acrylamide, 2-hydroxyethyl (methyl) acrylic acid ester, 2-hydroxypropyl (methyl) acrylic acid ester, (methyl) acrylic acid methoxy poly (ethylene glycol) ester, (methyl) single polyalkylene glycol acrylate ester, vinylpyridine, N-vinyl pyrrolidone, N-acryloyl group piperidines, N-acryloyl group pyrrolidines and N-vinyl acetamide; And such as N; N-dimethylaminoethyl (methyl) acrylic acid ester, N; N-diethyllaminoethyl (methyl) acrylic acid ester, N, N-dimethylamino-propyl (methyl) acrylic acid ester, N, the unsaturated cationic monomer of N-lignocaine propyl group (methyl) acrylamide and quaternary ammonium salt thereof.The use amount of the monomer beyond these acrylic acid and/or its salt is preferably the 0mol% to 30mol% (containing) of monomer total amount, more preferably 0mol% to 10mol% (containing).
The water absorbing resin particle that uses in the embodiment of the present invention is the cross-linked polymer with internal crosslinking structure.Said internal crosslinking structure can be introduced into water absorbing resin particle; For example, through not using crosslinking agent self-crosslinking or the internal crosslinking agent through per molecule to contain the internal crosslinking agent copolymerization or the reaction (copolymerization or the reaction of preferred internal crosslinking agent) of two or more unsaturated polymerization property groups and/or two or more reactive groups.
The example of said internal crosslinking agent comprises: such as N; Trimethylolpropane tris (methyl) acrylic acid ester of N '-di-2-ethylhexylphosphine oxide (methyl) acrylamide, (gathering) ethylene glycol bisthioglycolate (methyl) acrylic acid ester, (gathering) propane diols two (methyl) acrylic acid ester, trimethylolpropane tris (methyl) acrylic acid ester, trimethylolpropane two (methyl) acrylic acid ester, glycerine three (methyl) acrylic acid ester, glycerine acrylate acrylic acid ester, oxirane modification, pentaerythrite four (methyl) acrylic acid ester, dipentaerythritol six (methyl) acrylic acid ester, TAC, cyamelide triallyl, TAP, triallylamine, gather (methyl) allyloxy alkane, (gathering) ethylene glycol diglycidylether, glycerine diglycidyl ether, ethylene glycol, polyethylene glycol, 1, the polyhydroxy-alcohol of 4-butanediol, propane diols, glycerine and pentaerythrite; Polymine; And glycidyl (methyl) acrylic acid ester.
Said arbitrary internal crosslinking agent can use separately, also can select to use two or more.In view of the water absorption character and the other factors of the water absorbing resin particle that obtains, preferred internal crosslinking agent must be a kind of compound that has two or more unsaturated polymerization property groups.The internal crosslinking agent that uses preferably accounts for the 0.005mol% to 3mol% (containing) of all monomers, more preferably accounts for 0.01mol% to 1.5mol% (containing), most preferably accounts for 0.05mol% to 0.2mol% (containing).
When polymerization, can add hydrophilic polymers such as cross-linked polymer such as starch-cellulose, starch-cellulose derivative, polyvinyl alcohol, polyacrylic acid (salt) or polyacrylic acid (salt), or such as the chain-transferring agent of hypophosphorous acid (hypophosphites).
Mode polymerization that can be through bulk polymerization, anti-phase suspension polymerisation or precipitation polymerization is as the monomer that contains aforesaid propylene acid and/or its salt of principal component.Yet,, be preferably and use the monomer that is dissolved in the water to carry out polymerisation in solution in view of the difficulty or ease of performance and control polymerization.These are aggregated in the following document and are described: for example, and the specification of the specification of the specification of the specification of the specification of United States Patent (USP) 4625001, United States Patent (USP) 4769427, the specification of United States Patent (USP) 4873299, United States Patent (USP) 4093776, the specification of United States Patent (USP) 4367323, United States Patent (USP) 4446261, the specification of United States Patent (USP) 4683274, United States Patent (USP) 4690996, the specification of United States Patent (USP) 4721647, the specification of United States Patent (USP) 4738867, the specification of United States Patent (USP) 4748076, the specification of u. s. published patent application 2002/40095.
In polymerization; Can use such as potassium peroxydisulfate, ammonium persulfate, sodium peroxydisulfate, tert-butyl hydroperoxide, hydrogen peroxide or 2 radical polymerization initiator of 2 '-azo two (2-amidine propane) dihydrochloride or such as the active energy ray of ultraviolet ray or electron beam.Under the situation of using radical polymerization initiator, can be used in combination a kind of reducing agent and carry out redox polymerization such as sodium sulfite, sodium hydrogensulfite, ferrous sulfate or L-ascorbic acid.The polymerization initiator that uses preferably accounts for the 0.001mol% to 2mol% (containing) of all monomers, more preferably accounts for 0.01mol% to 0.5mol% (containing).
Can use gel, suspended particulates and the similar substance of the dry polymerization of conventional drying machine or heating furnace.Selectively, can be through the dry said material of azeotropic dehydration.Drying machine can for, for example, drying machine, groove type stirring drier, rotary drier, disk drying machine, fluidized bed drying machine, pneumatic drier or infrared drier in the hot blast.
Preferably at 100-250 ℃, more preferably at 150-230 ℃, also more preferably at the 160-210 ℃ of said material of drying.
Preferably, solid content accounts for the 50-100 quality % (water content: 50-0 quality %), more preferably account for 85-100 quality % (water content: 15-0 quality %), also more preferably account for 90-98 quality % (water content: 10-2 quality %) of gained desciccate.Usually calculate the ratio of said solid content according to the weightlessness of 1g sample drying after 3 hours in 180 ℃ of aluminium cups or glass dish.
Can use following equipment crushing/pulverizing desciccate; For example; Vibrating mill, roll shaft comminutor are (referring to japanese unexamined patent publication 9-235378/1997 (spy opens flat 9-235378); 0174 section), pawl type pulverizer, roll shaft grinding machine (referring to PCT application japanese publication translation (special table) 2002-527547,0069 section), high-speed rotary pulverizer (pin type grinding machine, hammer grinding machine, screw rod grinding machine, ring-roller mill etc. (referring to japanese unexamined patent publication 6-41319/1994 (spy opens flat 6-41319), 0036 section); Or cylindric mixer (referring to japanese unexamined patent publication 5-202199/1993 (spy opens flat 5-202199), 0008 section).When using pneumatic drier or similar machine, product can be crushed simultaneously and be dry.
Preferably, have predetermined size (little particle diameter distributes), for example, carry out classification before through resin surface crosslinked (hereinafter detailed description) through above-mentioned drying and water-absorbing resin that crushing/pulverizing obtained.Preferably, as non-condensation product water-absorbing resin (hereinafter detailed description), when needing, also make the condensation product of water absorbing resin particle have predetermined size through classification.
The shape of the water absorbing resin particle that is obtained by above-mentioned polymerization for example is amorphous broken shape, spherical, fibrous, bar-shaped, spherical or flat basically usually.Because if said particulate is when being amorphous broken shape, its can be at least on the surface of said particulate or the near surface of said particulate contain a large amount of silica (hereinafter detaileds description), so said particulate is preferably amorphous broken shape.
Preferably, water absorbing resin particle according to the present invention has in the crosslinked zone of near surface through organic surface crosslinking agent and/or water-soluble inorganic surface crosslinking agent.When this situation occurring, the water-absorbing resin that is included in the water absorbing agent has in the crosslinked zone of near surface through surface crosslinking agent.When the water absorbing agent that expands places pressure following time, said crosslinked area decreases the amount of the liquid that possibly ooze out.Thereby strengthened the water imbibition under the AAP pressure.
The example that can be used for surface-crosslinked surface crosslinking agent comprise have can with two or more the organic surface crosslinking agent and/or the water-soluble inorganic surface crosslinking agent of functional group of the functional group of water absorbing resin particle, particularly carboxyl reaction.The organic surface crosslinking agent of preferred water dissolubility.
Example comprises such as ethylene glycol, diethylene glycol, propane diols, triethylene glycol, TEG, polyethylene glycol, 1, ammediol, DPG, 2,2; 4-trimethyl-1,3-pentanediol, polypropylene glycol, glycerine, polyglycerol, 2-butene-1,4-glycol, 1; 3-butanediol, 1; 4-butanediol, 1,5-pentanediol, 1,6-hexylene glycol, 1; 2-cyclohexyl dimethanol, 1, polyalcohols such as 2-cyclohexanol, trimethylolpropane, diethanol amine, triethanolamine, PPOX, ethylene oxide-oxypropylene block copolymer, pentaerythrite and D-sorbite; Such as epoxides such as ethylene glycol diglycidylether, polyethyleneglycol diglycidylether, glycerine polyglycidyl ether, two glycerine polyglycidyl ethers, polyglycerol polyglycidyl ether, propylene glycol diglycidylether, polypropylene glycol diglycidyl ether and glycidols; Such as ethylenediamine, Diethylenetriamine, three second tetramines, tetren, five second hexamines and gather polyamine compounds such as Ethylenimine, with and inorganic salts or organic salt (for example, azidocarbonyl salt etc.); Such as 2, polyisocyanate compounds such as 4-benzyl support vulcabond and hexamethylene diisocyanate; Such as 1,2-ethylene two is the multivalence isoxazoline compound oh of azoles quinoline oh; Such as urea, thiocarbamide, guanidine, cyanoguanidines and 2-carbonic acid derivative such as oxazolidinedione oh; Such as 1,3-dioxolanes-2-ketone, 4-methyl isophthalic acid, 3-dioxolanes-2-ketone, 4,5-dimethyl-1; 3-dioxolanes-2-ketone, 4,4-dimethyl-1,3-dioxolanes-2-ketone, 4-ethyl-1,3-dioxolanes-2-ketone, 4-methylol-1; 3-dioxolanes--2-ketone, 1,3-diox-2-ketone, 4-methyl isophthalic acid, 3-diox-2-ketone, 4; 6-dimethyl-1,3-diox-2-ketone and 1,3-dioxy isopentane-carbonic acid alkylene ester compounds such as 2-ketone; Such as halogenated epoxides such as epoxychloropropane, epoxy bromopropane and Alpha-Methyl epoxychloropropane, with and polyamine addition product (Kymene (registration mark) that for example produces) by He Ke man of great strength group company (Hercules Incorporated); Silane coupler such as γ-Huan Yangbingyangbingjisanjiayangjiguiwan and gamma-aminopropyl-triethoxy-silane; And such as oxa-fourth cycle compounds such as 3-methyl-3-oxa-fourth ring methyl alcohol, 3-ethyl-3-oxa-fourth ring methyl alcohol, 3-butyl-3-oxa-fourth ring methyl alcohol, 3-methyl-3-oxa-fourth ring ethanol, 3-ethyl-3-oxa-fourth ring ethanol, 3-butyl-3-oxa-fourth ring ethanol, 3-chloromethyl-3-methyl oxa-fourth ring, 3-chloromethyl-3-ethyl oxa-fourth ring and multivalence oxa-fourth cycle compounds.
Can use in these surface crosslinking agents any separately; Also can select to use together in these surface crosslinking agents two or more.Wherein, preferably has monohydroxy at least surface crosslinking agent.Especially, because polyalcohol is as safe as a house, and can improve the hydrophily on water absorbing resin particle surface, so preferred polyol.
Preferably, the surface crosslinking agent of use accounts for 0.001 mass parts to 5 (containing) mass parts in per 100 mass parts of water absorbing resin particle solid content.
When surface crosslinking agent and water absorbing resin particle mixing, can make water.Preferably, the water of use accounts for 0.5 (not containing) mass parts to 10 mass parts (containing) in per 100 mass parts of water absorbing resin particle solid content, more preferably accounts for 1 mass parts (containing) to 5 mass parts (containing).
When surface crosslinking agent or its aqueous solution were mixed with water absorbing resin particle, hydrophilic organic solvent or tertium quid matter can be used as auxiliary agent and use.The example of this type of hydrophilic organic solvent comprises: such as lower alcohols such as methyl alcohol, ethanol, normal propyl alcohol, isopropyl alcohol, n-butanol, isobutanol and the tert-butyl alcohols; Ketone such as acetone; Such as ethers such as diox, oxolane and methoxyl group (gathering) ethylene glycol; Such as epsilon-caprolactams and N, the amide-type of dinethylformamide; Sulfoxide class such as dimethyl sulfoxide (DMSO); And such as ethylene glycol, diethylene glycol, propane diols, triethylene glycol, tetraethylene glycol, polyethylene glycol, 1, ammediol, DPG, 2,2; 4-trimethyl-1,3-pentanediol, polypropylene glycol, glycerine, polyglycerol, 2-butene-1,4-glycol, 1; 3-butanediol, 1; 4-butanediol, 1,5-pentanediol, 1,6-hexylene glycol, 1; 2-cyclohexanedimethanol, 1, polyalcohols such as 2-cyclohexanol, trimethylolpropane, diethanol amine, triethanolamine, polyoxypropylene, oxygen ethene-oxypropylene block copolymer, pentaerythrite and sorbierite.
Preferably, the hydrophilic organic solvent of use can account for 10 mass parts in per 100 mass parts of water absorbing resin particle solid content or lower, more preferably accounts for 0 mass parts to 5 mass parts (containing) or 0.1 mass parts to 5 mass parts (containing).Yet the use amount of hydrophilic organic solvent can change according to kind, particle diameter, moisture content and the other factors of water absorbing resin particle.
Tertium quid matter for example can be inorganic acid, organic acid or the polyaminoacid described in the specification of European patent 0668080.Said mixed aid can be used as surface crosslinking agent, but is preferably the water absorbing capacity that should not influence water absorbing resin particle after surface-crosslinked negatively.Preferably, the water absorbing resin particle of embodiment of the present invention is through being that the surface crosslinking agent of 100 ℃ or lower hydrophilic organic solvent mixes, heating is carried out crosslinked then with particulate with not containing boiling point.If water absorbing resin particle contains boiling point at 100 ℃ or following hydrophilic organic solvent, the hydrophilic organic solvent that is retained in the surface crosslinking agent of water-absorbent resin particle surface can volatilize, and changes environment.It may not obtain sufficient SFC and other physical property.
When surface crosslinking agent and water absorbing resin particle are mixed,, preferably also have water-soluble inorganic salt (being preferably persulfate) in order to obtain the more uniform mixture of water absorbing resin particle and surface crosslinking agent.Preferably, the water-soluble inorganic salt of use accounts for 0.01 mass parts to 1 mass parts (containing) in per 100 mass parts of water absorbing resin particle solid content, more preferably accounts for 0.05 mass parts to 5 mass parts (containing).Yet the use amount of water-soluble inorganic salt can be according to kind and the particle diameter and the other factors variation of water absorbing resin particle.In other words; Preferably, the water absorbing resin particle of embodiment of the present invention is through being that the organic surface crosslinking agent and/or the water-soluble inorganic surface crosslinking agent of the water-soluble inorganic salt (being preferably persulfate) of 0.01 quality % to 1.0 quality % (containing) mixes, adds then hot mixt and carry out crosslinked with particulate with containing with respect to the water absorbing resin particle ratio.
The method of blending surface crosslinking agent and water absorbing resin particle is not subject to any specific mode.For example, water absorbing resin particle can be immersed in the hydrophilic organic solvent, and as required be dissolved in water and/or hydrophilic organic solvent in surface crosslinking agent mix.The example of another kind of mixed method can be for directly being dissolved in the surface crosslinking agent spraying in water and/or the hydrophilic organic solvent or dripping to water absorbing resin particle.
After blending surface crosslinking agent and water absorbing resin particle, preferably heat usually to carry out cross-linking reaction.Though said heat treated temperature is transformable according to employed surface crosslinking agent, be preferably from 40 ℃ to 250 ℃ (containing), and more preferably from 150 ℃ to 250 ℃ (containing).If the heat treated temperature is lower than 40 ℃, AAP, SFC and other absorption characteristic possibly fail to be improved fully so.Should arouse attention, if heating-up temperature is higher than 250 ℃, the overheated water absorbing resin particle that possibly make is demoted, and therefore makes various physical characteristics degradations.The heat treated time is preferably from 1 minute to 2 hours (containing), and more preferably from 5 minutes to 1 hour (containing).
The water absorbing resin particle that is used for embodiment of the present invention preferably has 200 μ m to 500 μ m (containing), more preferably has the quality average particle size particle size of 300 μ m to 400 μ m (containing).If the quality average particle size particle size of water absorbing resin particle is outside scope 200 μ m to 500 μ m, liquid immersion property and diffusivity possibly descend significantly, or the water absorption rate big value that possibly descend.For example, if those water absorbing resin particles are used for diaper, may leak or exist other defective.
Preferably, 5 quality % of the water absorbing resin particle of embodiment of the present invention or lower particulate can be through the sieves of mesh 150-μ m, and more preferably, 3 quality % or lower particulate can be through the sieves of mesh 150-μ m.Use the amount that has limited the dust in the water absorbing agent that produces as the water absorbing resin particle in these scopes of water absorbing agent.Thereby in the preparation process of water absorbing agent, the fine grained in the water absorbing resin particle will can not wave to air, can not cause safety/hygienic issues.In addition, the physical characteristic of the water absorbing agent of generation can not demoted yet.If ratio surpasses 5 quality %, in the preparation process of water absorbing agent, possibly produce dust, possibly cause safety/hygienic issues or the physical characteristic of water absorbent core is demoted, thereby enumerate out some problems.
Water absorbing resin particle can be 300 μ m or littler micro mist shape water absorbing resin particle (when needing, hereinafter being called " micro mist ") for the quality average particle size particle size, and it is assembled, dry, adjustment particle diameter and surface-crosslinked.Alternatively, water absorbing resin particle can be pulverized brokenly, obtains primary particle by pulverizing, and it partly mixes with the condensation product of micro mist.When the condensation product of micro mist partly mixes with water absorbing resin particle, the water absorption character of the water absorbing agent of generation, for example water absorption rate and FHA further are improved.The amount of the condensation product of the micro mist that mixes with water absorbing resin particle is preferably 5 quality % or more, and more preferably 10 quality % or more further are preferably 15 quality % or more, most preferably are 20 quality % or more.Define the particle diameter of micro mist according to the mesh diameter of the sieve that uses in the classification.
Can prepare the micro mist condensation product through any known micro mist regeneration techniques.For example, micro mist can mix with warm water and dry (United States Patent (USP) 6,228,930 specification); Micro mist can with the aqueous solution and the polymerization (United States Patent (USP) 5,264,495 specification) of monomer.Add adding water to micro mist, this mixture is being higher than granulation under the surface pressing of particular value (specification of European patent the 844270th).Make micro mist fully wetting to form amorphous gel, subsequent drying is also pulverized (United States Patent (USP) 4,950,692 specification).Micro mist can mix (United States Patent (USP) 5,478,879 specification) with polymeric gel.
Preferably, micro mist mixes with warm water, and uses one of the method drying of as above summary.Water absorbing resin particle through said method granulation has loose structure (being equal to the structure of describing among japanese unexamined patent publication (spy opens) 2004-261797) and is fit to use.Preferably, the 5 quality % or the more particles of the water absorbing resin particle of embodiment of the present invention have loose structure, more preferably 10 quality % or more, and also preferred 15 quality % or more, most preferably 20 quality % or more have loose structure more.Comprise in the water absorbing resin particle micro mist condensation product that has loose structure make water absorbing resin particle can be at least from the teeth outwards or near surface contain effectively silica or other water insoluble inorganic particle (hereinafter detailed description).
The CRC of the water absorbing resin particle of embodiment of the present invention is preferably 5g/g or more, and more preferably 10g/g or more further is preferably 15g/g or more, even is preferably 25g/g or more, also is preferably 28g/g or more, most preferably is 30g/g or more.Though the maximum of CRC is not subject to any specific mode, be preferably 50g/g or still less, 45g/g or still less more preferably further is preferably 40g/g or still less.If CRC is lower than 10g/g, water absorbing resin particle is used for water absorbing agent, and said water absorbing agent absorbs very little amount.On the other hand, if CRC is higher than 50g/g, water absorbing resin particle is used for water absorbent core, and the gained water absorbing agent may not provide time per unit to have the water absorbent core of excellent liquid absorptivity.
The AAP of the water absorbing resin particle of embodiment of the present invention is preferably 16g/g or more; 17g/g or more more preferably; Even 18g/g or more more preferably, 19g/g or more more preferably also, also 20g/g or more more preferably; Be preferably 22g/g or more again, most preferably be 24g/g or more.Though the maximum of AAP is not subject to any specific mode, be preferably 30g/g or still less.If AAP is lower than 16g/g, water absorbing resin particle is used for water absorbing agent, and when water absorbing agent places pressure following time, the water absorbing agent of generation may not obtain low Test Liquid Permeability of Core or " wetting again ".
The SFC of the water absorbing resin particle of embodiment of the present invention is preferably 10 (10 -7Cm 3Sg -1) or higher, more preferably 15 (10 -7Cm 3Sg -1) or higher, further be preferably 30 (10 -7Cm 3Sg -1) or higher, even more preferably 50 (10 -7Cm 3Sg -1) or higher, also more preferably 70 (10 -7Cm 3Sg -1) or higher, and most preferably be 100 (10 -7Cm 3Sg -1) or higher.If SFC is lower than 10 (10 -7Cm 3Sg -1), even said particle contains silica or other water-insoluble inorganic particle (hereinafter detailed description), permeability for liquids can not improved yet.In addition, when water absorbing resin particle was used for water absorbing agent, the water absorbing agent of generation may not provide time per unit to have the water absorbent core of excellent liquid absorptivity.
But (water-extractable) polymer content of the extraction water of the water absorbing resin particle of embodiment of the present invention is preferably 35 quality % or lower, 25 quality % or lower more preferably, and further be preferably 15 quality % or lower.If but the polymer content of extraction water surpasses 35 quality %, said particle demonstrates inferior gel strength and permeability for liquids.If water absorbing resin particle is used for water absorbent core, when water absorbent core places pressure following time, the water absorbing agent of generation may not obtain low Test Liquid Permeability of Core or " wetting again ".
The water-insoluble inorganic particle
The water absorbing resin particle of embodiment of the present invention at least from the teeth outwards or near surface contain the water-insoluble inorganic particle." surface " of water absorbing resin particle refers to those and is exposed to airborne part." near surface " of term water absorbing resin particle refers between 1/10th the degree of depth of the surface of particle and about particle diameter (littler size) those and is exposed to airborne part.Particularly, under the situation of surface-crosslinked water absorbing resin particle, " near surface " of term water absorbing resin particle refers to those parts near surface-crosslinked layer.The thickness of said layer for example, can use SEM (SEM) to confirm.
At least on the surface of water absorbing resin particle or the water-insoluble inorganic particle that provides of near surface caused the improvement of the permeability for liquids of water absorbing agent.Therefore, the SFC that contains the water absorbing agent of water absorbing resin particle is improved.If the water-insoluble inorganic particle remains on the surface of water absorbing resin particle at least or near surface will be enough as far as the purpose of improving permeability for liquids.If particle residue is on the surface of water absorbing resin particle but not near surface, the physical characteristic of water absorbing agent will be improved better.Among the embodiment described in detail below, the water-insoluble inorganic particle is from the teeth outwards residual at least.In addition, through adding the water-insoluble inorganic particle, the ratio that remains in lip-deep water-insoluble inorganic particle is improved after polymerization.
Preferably, the water-insoluble inorganic particle that is used for embodiment of the present invention contains the functional group that can form ionic bond with the lip-deep functional group of water absorbing resin particle at least from the teeth outwards.The functional group that can form ionic bond is cation group more preferably, even more preferably amino (containing the season amino group).
In a kind of water absorbing agent of preferred form, remaining in the lip-deep functional group of water absorbing resin particle is carboxyl, and the lip-deep functional group that remains in the water-insoluble inorganic particle at least is for amino.
The concrete example that can be used for the water-insoluble inorganic particle of embodiment of the present invention comprises such as mineral substance products such as talcum, clay, kaolin, bleaching earth, bentonite, activated clay, bolognian stone, bitumen, strontium ore, ilmenite and perlites; Metal oxide such as silica and titanium oxide; Silicic acid (salt) such as natural zeolite and synthetic zeolite; Water-insoluble multivalent metal salt such as calcium sulfate and aluminium oxide; Hydrophily amorphous silicon di-oxide (seasoning for example: the ReolosilQS-20 of moral mountain company (Tokuyama Corporation).The precipitation method: Sipernat22S, the Sipernat2200 of Degussa Co., Ltd (Degussa AG)); The moisture compound (composite, water-containing hydratedoxides) (for example, seeing the international application of announcing according to PCT WO2005/010102) that contains the oxide that combines with water of zinc and silicon or zinc and aluminium; Complex oxide such as silica/magnesia compound (for example pacifying the Attagel#50 of lattice Hart company (ENGELHARD)), silica compound and silica/magnesia compound.United States Patent (USP) 5,164,459 also disclose the water-insoluble inorganic particle, also can use European patent 761241.Preferably silica and silicic acid (salt) in these examples.The special preferably silica and the silicic acid (salt) of fine particulate form, the fine grain average particle size particle size that records through Ku Erte (Coulter) counting method is from 0.001 to 200 μ m.
Some the concrete HDK that is exemplified as Wa Ke company (Wacker) (registration mark) H2015EP, H2050EP, H2150VP, H05TA, H13TA and H30TA of being used for the most preferred water-insoluble inorganic particle of embodiment of the present invention, it has the amino amorphous silica of (containing season amino) for having introduced in its surface.Also can use the emerging product of Japanese bright dipping Co., Ltd (Nippon Aerosil Co., RA200HS Ltd.).
When the particle of 4 quality % amount was dispersed in the methanol aqueous solution (volume ratio 1:1), the pH that is used for the water-insoluble inorganic particle of embodiment of the present invention was preferably 7 to 10.
The quality average particle size particle size of primary granule form that is used for the water-insoluble inorganic particle of embodiment of the present invention is preferably 5 to 50nm, and 90 quality % in the particle or mostly be the aggregated particle of primary granule.The quality average particle size particle size of the aggregated particle of primary granule is preferably 20 μ m or littler.
The water-insoluble inorganic particle that is used for embodiment of the present invention is the (2SiOH/nm of the silanol group that lip-deep silanol fiduciary point is whole from the teeth outwards 2) preferably have 20% or residual silanol group still less.
Be used for the specific area that the water-insoluble inorganic particle of embodiment of the present invention records through BET and be preferably 30 to 330m 2/ g.
Silica
Described above, in embodiments of the invention, the water-insoluble inorganic particle preferably contains silica.
Silica at least on the surface of water absorbing resin particle or the condition of near surface cause the improvement of the permeability for liquids of water absorbing agent.Therefore, the SFC that contains the water absorbing agent of water absorbing resin particle is improved.If water silica remains on the surface of water absorbing resin particle at least or near surface will be enough as far as the purpose of improving permeability for liquids.The near surface if silica is from the teeth outwards residual, the physical characteristic of water absorbing agent will be improved better.
Silica is preferably the amorphous white carbon through the seasoning preparation.Because " quartzy (Quartz) " and similar silica possibly cause healthy risk, so it is undesirable.Silica does not preferably experience self-induced gathering, and contains the residual silanol group of high concentration.The self-induction gathering of silica is the reason by the amount increase of the dust of water absorbing agent generation.Embodiment of the present invention are used the silica of the amount of particular range, and the residual silanol group that silica contains the concentration of particular range assembles with the self-induction that prevents silica, thus the increase of the amount of the dust that prevents to produce by water absorbing agent.
Keep flat nanometer (nm according to one 2) in the concentration of lip-deep residual silanol group of number definition silica of silanol group.In the present invention, applying unit " SiOH/nm 2".Can consult and to find residual silanol group concentration from catalogue or the similar file that silica manufacturer obtains.Selectively, also can measure (for example lithium aluminium hydride method) through known method.
In embodiments of the invention, the concentration of the residual silanol group on the silica surface is preferably 1.7SiOH/nm 2Or it is lower.In low residual silanol group concentration like this, silica is modified on the surface, thereby hydrophobic.If concentration surpasses 1.7SiOH/nm 2, silica possibly assembled, thereby produces dust, and this is undesirable.The surface modification of silica has stoped between the silanol group that to form hydrogen strong, thereby stops the silica aggregate of fine particulate form.The content of silica is low to moderate the 10ppm to 1 of water absorbing resin particle, 900ppm (containing).Use the silica of the non-gathering of low content like this, its fine grained is adsorbed to water absorbing resin particle through the interparticle cohesion such as electrostatic force and Van der Waals force.Therefore, because the condition of the silica in the water absorbing resin particle, the amount of the dust of generation is limited.
If the concentration of the residual silanol groups in the silica that uses surpasses 1.7SiOH/nm 2, the residual many silanol groups of meeting on the surface of silica; It is strong to form hydrogen between the silanol group, and the fine grained of silica is assembled.The fine grained of assembling is not adsorbed by water absorbing resin particle well, thereby is easy to come off.The formation dust thereby particulate waves.The amount of restriction dust is difficult.
The concentration of the residual silanol group on the silica surface is preferably 1.7SiOH/nm 2Or lower, more preferably from 0.7SiOH/nm 2To 1.7SiOH/nm 2(containing), further be preferably from 0.9SiOH/nm 2To 1.7SiOH/nm 2If concentration is lower than 0.7SiOH/nm 2, it is more hydrophobic that silica becomes, thus LDV drops, and this is undesirable.
The concrete example that is included in the silica in the water absorbing resin particle comprises HDK (registration mark) H15 (≌ 0.96SiOH/nm 2), H20 (≌ 1.00SiOH/nm 2), H30 (≌ 1.08SiOH/nm 2), H1303VP (≌ 0.36SiOH/nm 2), H2000/4 (≌ 0.60SiOH/nm 2), H2000T (≌ 0.36SiOH/nm 2) and H3004 (≌ 0.40SiOH/nm 2), it all can obtain from Wa Ke company.The example of silica comprises H05TD, H13TD, H20TD, H30TD, H05TM, H13TM, H20TM, H30TM, H05TX, H13TX, H20TX and H30TX, all has the about 0.40SiOH/nm of concentration 2Or lower residual silanol group.Other example comprises Aerosil (registration mark) R-972 (≌ 0.60SiOH/nm2), R-974 (≌ 0.39SiOH/nm 2), R805 (≌ 1.66SiOH/nm 2), R812 (≌ 0.44SiOH/nm 2), R812S (≌ 0.68SiOH/nm 2) and R202 (≌ 0.29SiOH/nm 2), it is all produced by the emerging product of Japanese bright dipping Co., Ltd, Reolosil (registration mark) MT-10 (C), DM-10 (C), DM-30, DM-30S, KS-20SC, HM-20L, HM-30S and PM-20 (L), and it is all produced by moral mountain company.
Water absorbing agent
The water absorbing agent of embodiment of the present invention contains the water absorbing resin particle with internal crosslinking structure through the polymerization acquisition of water-soluble unsaturated monomer.Said water absorbing agent satisfies following condition (a) to (d):
(a) the water absorbing agent amount is from 10ppm to 1, the water-insoluble inorganic particle of 900ppm (containing);
(b) water absorbing agent contains 5 quality % or lower and has the particle of size that can be of a size of the sieve of 150 μ m through aperture openings;
(c) under the pressure of 4.83kPa (AAP), the water absorbing capacity of water absorbing agent is 18g/g or higher; And
(d) the water-insoluble inorganic particle remains on the surface of water-absorbing resin or near surface.
The amount of the water-insoluble inorganic particle that the water absorbing agent in the embodiment of the present invention contains with respect to water absorbing agent from 10ppm to 1,900ppm (containing), more preferably 10 to 1,500ppm, most preferably 10 to 990ppm.If contain too many water-insoluble inorganic particle, may cause the misgivings of safety/health owing to particulate in the process of preparation water absorbent core waves, and the performance of water absorbent core can be demoted.If too many water-insoluble inorganic particle is used for water absorbent core, the water absorbing agent of generation possibly make water absorbent core not demonstrate enough vertical liquid absorption capacities (being fixed height absorption ability (FHA)).
In the water absorbing agent in the embodiment of the present invention, can use and not experience as yet that self-induction is assembled or self-induction is assembled and passed through, for example (residual silanol group concentration is 1.7SiOH/nm to the above-mentioned silica of silica replacement that is broken of mechanical force on the surface 2Or it is lower).Working concentration is 1.7SiOH/nm 2Or the silica of lower residual silanol group is merely one of mode of restriction silica self-induction gathering.Can confirm through the fine grained that leaches through analysis in amount (hereinafter detailed description) back of measuring dust whether the silica in the water absorbing resin particle has experienced or do not experienced as yet the self-induction gathering.For example, use SEM or X-ray microanalyser to observe the fine grained that leaches; If the maximum diameter of the silica dioxide granule of in fine grained, finding is 20 μ m to 100 μ m (containing); And those maximum diameters are that the silica dioxide granule of 20 μ m to 100 μ m (containing) is 10% or higher with respect to the ratio of the granule amount that leaches, and confirm that so silica has experienced the self-induction gathering.
In other words, the water absorbing agent of embodiment of the present invention contains the water absorbing resin particle with internal crosslinking structure through the polymerization acquisition of water-soluble unsaturated monomer.In said water absorbing agent, water absorbing resin particle through surface crosslinking agent crosslinked near surface, and at least from the teeth outwards or near surface contain silica.In addition, after the amount of the dust in measuring water absorbing agent, be in the particulate of 20 μ m to 100 μ m (containing) at the maximum diameter that leaches, silica comprises 10% or still less.In addition, the dioxide-containing silica in the water absorbing agent is 10ppm to 1,900ppm (containing).The quality average particle size particle size of water absorbing agent is from 200 μ m to 500 μ m (containing).The particle that is of a size of the sieve of 150 μ m through aperture openings accounts for 5 quality % or lower of whole water absorbing agent quality.
The water absorbing agent of embodiment of the present invention preferably contains at least 0.001 quality % to 5 quality % (containing), more preferably contains the multivalent metal salt of 0.01 quality % to 1 quality % (containing).The sufficiency of the multivalent metal salt in the water absorbing agent (being preferably three value water-soluble multivalent metal salts) makes and is keeping absorptive while under the 4.83kPa load also to improve the fixed height absorption ability of salt solution water conservancy diversion rate and water absorbing agent fully.When not having silica or other water-insoluble inorganic particle, said condition has also remedied at least on the surface of water absorbing agent or near surface lacks silica or other water-insoluble inorganic particle.Because the cooperative effect of silica or other water-insoluble inorganic particle and multivalent metal salt, the water absorbing agent of acquisition has more excellent physical characteristics.
The concrete example that can be used for the multivalent metal salt of embodiment of the present invention comprises sulfate, nitrate, carbonate, phosphate, acylate and the halide of Zn, Be, Mg, Ca, Sr, Al, Fe, Mn, Ti, Zr, Ce, Ru, Y, Cr and metalloid (for example chloride).Other be exemplified as the multivalent metal salt of in japanese unexamined patent publication (spy opens) 2005-11317, describing.
Said multivalent metal salt is most preferred to be the trivalent water-soluble metal salt.The concrete example of three value water-soluble multivalent metal salts comprises aluminium chloride, polyaluminium chloride, aluminum sulfate, aluminum nitrate, aluminum potassium sulfate, aluminum sodium sulfate, potassium alum, ammonia-alum, soda alum, sodium aluminate, iron chloride (III), cerium chloride (III), ruthenic chloride (III), yttrium chloride (III) and chromium chloride (III).
In addition, in view of the urine that absorbs and the dissolubility of other liquid, these salt of use preferably contain the crystallization water.Wherein, preferred especially aluminium compound, especially, preferred aluminium chloride, polyaluminium chloride, aluminum sulfate, aluminum nitrate, aluminum potassium sulfate, aluminum sodium sulfate, potassium alum, ammonia-alum, soda alum and sodium aluminate.Especially preferably sulfuric acid aluminium.Most preferably the aqueous solution of aluminum sulfate (hope be concentration be 90% or the saturated solution of higher aluminum sulfate).Can use in these compounds any separately; Selectively, also can use wherein two or more together.One of water absorbing agent of most preferred form in the embodiment of the present invention is for containing the water absorbing agent of silica and three value water-soluble multivalent metal salts.
The water absorbing agent of embodiment of the present invention produces low amounts of dust.If can there be (ifpresent at all) dust inevitably; As use Heubach dust gauge measured (hereinafter detailed description), be preferably 400ppm or lower, more preferably 355ppm or lower; Further be preferably 300ppm or lower, also 240ppm or lower more preferably.In the process of preparation water absorbing agent, as long as satisfy one of these conditions, if contain silica or other water-insoluble inorganic particle in the water absorbing agent, it will can not diffuse in the air, can not cause safety/hygienic issues.Equally, the physical characteristic of water absorbent core also can not be demoted.
The quality average particle size particle size size of water absorbing agent is preferably 200 μ m to 500 μ m (containing), more preferably 300 μ m to 400 μ m (containing).If quality average particle size particle size size is outside 200 μ m to 500 mu m ranges, permeability for liquids possibly reduce, and the liquid-absorbent rate of the time per unit of water absorbing agent also possibly reduce significantly.In other words, water absorption rate possibly reduce a big value, for example, if said water absorbing agent is used for diaper, may leak or exist other defective.
Preferably, can be the 5 quality % or lower that the particle of the sieve of 150-μ m accounts for water absorbing agent through mesh.More preferably, said ratio is 4 quality % or lower, and further is preferably 3 quality % or lower.If ratio surpasses 5 quality %; Even when containing silica or other water-insoluble inorganic particle in embodiment of the present invention; In the preparation process of water absorbing agent, particle also possibly wave, and possibly cause safety/hygienic issues or the physical characteristic of the water absorbent core of acquisition is demoted.
The particle size distribution of water absorbing agent preferably has the logstandard deviation (σ ζ) of 0.20 to 0.50 (containing), 0.20 to 0.40 (containing) more preferably, even 0.30 to 0.40 (containing) more preferably.If standard deviation is outside these scopes, permeability for liquids possibly reduce makes water absorbent core have very inferior time per unit water absorption rate.
The CRC of said water absorbing agent is preferably 5g/g or more, 10g/g or more more preferably, even 15g/g or more more preferably, and also 25g/g or more more preferably also is preferably 28g/g or more.Though the maximum of CRC is not subject to any specific mode, be preferably 50g/g or still less, 45g/g or still less more preferably, even 40g/g or still less more preferably.If CRC is lower than 5g/g, the amount of the liquid that water absorbing agent absorbs very little consequently can not be as diaper and other cleaning/hygienic material.If centrifugal water holding capacity (CRC) is greater than 50g/g, and the water absorbing agent that obtains is used for water absorbent core, and said core maybe not can demonstrate the liquid-absorbent rate of the time per unit that gets into the excellence in the water absorbent core.
The SFC of the water absorbing agent of embodiment of the present invention is preferably 10 (10 -7Cm 3Sg -1) or higher, more preferably 15 (10 -7Cm 3Sg -1) or higher, even more preferably 30 (10 -7Cm 3Sg -1) or higher, also more preferably 50 (10 -7Cm 3Sg -1) or higher, also more preferably 70 (10 -7Cm 3Sg -1) or higher, most preferably be 100 (10 -7Cm 3Sg -1) or higher.If SFC is lower than 10 (10 -7Cm 3Sg -1), even when adding silica or other water-insoluble inorganic particle, permeability for liquids can not improved yet.When the water absorbing agent that obtains is used for water absorbent core,, can not demonstrate the liquid-absorbent rate of excellent time per unit to water absorbent core.Though maximum SFC is not subject to any specific mode, is preferably 2,000 (10 -7Cm 3Sg -1) or lower.
The water absorbing agent of embodiment of the present invention preferably has the CRC and the SFC of well balanced.Particularly, if CRC is 5g/g or higher and be lower than 25g/g, SFC is preferably 100 (10 so -7Cm 3Sg -1) or 150 (10 -7Cm 3Sg -1) or higher, even more preferably 300 (10 -7Cm 3Sg -1) or higher.If CRC is 25g/g or higher and be lower than 30g/g, SFC is preferably 30 (10 so -7Cm 3Sg -1) or higher, even be preferably 70 (10 -7Cm 3Sg -1) or higher, most preferably be 100 (10 -7Cm 3Sg -1) or higher.If CRC is that SFC is preferably 10 (10 so from 30g/g (containing) to 50g/g (not containing) -7Cm 3Sg -1) or higher, more preferably 15 (10 -7Cm 3Sg -1) or higher, even more preferably 30 (10 -7Cm 3Sg -1) or higher, most preferably be 50 (10 -7Cm 3Sg -1).
If CRC and SFC are in one of these scopes, when water absorbing agent was used for water absorbent core, it demonstrated sufficiently high water imbibition, and it has remedied possible permeability for liquids.On the other hand, if permeability for liquids is high, even water absorbing agent absorbs a spot of liquid, liquid also spreads in water absorbing agent, makes it see through a wide zone and absorbs.Thereby when the water absorbing agent that produces was used for water absorbent core, it demonstrated the liquid-absorbent rate of excellent time per unit.
The absorbability of water absorbing agent under the pressure of 4.83kPa (AAP) is 18g/g or more.This is worth 20g/g or more more preferably, even 22g/g or more more preferably, most preferably is 24g/g or more.Though the maximum of AAP is not subject to any specific mode, be preferably 30g/g or still less.If the absorbability under the pressure of 4.83kPa (AAP) is lower than 18g/g, when water absorbing agent was used for water absorbent core, water absorbent core placed pressure following time, possibly cause big quantity of fluid infiltration, or " wetting again ".
In whole water absorbing agents, those particle diameters are preferably 90 quality % or more for the particle from 150 μ m to 850 μ m.More preferably, those particle diameters are preferably 90 quality % or more for the particle from 150 μ m to 600 μ m.
The polymer content that can absorb water in the water absorbing agent is preferably 35 quality % or still less, 25 quality % or still less more preferably, even 15 quality % or still less more preferably.If the polymer content that can absorb water in the water absorbing agent surpasses 35 quality %, gel presents inferior intensity and permeability for liquids.In addition, if water absorbing agent is used for diaper in during long-term, CRC and AAP etc. are along with the time may demote.
Preferably, water absorbing agent has negative electrical charge behind the experience fricting movement.This has stoped the gathering of silica and water absorbing agent, and has limited silica and come off from water absorbing resin particle.Therefore, reduced the amount of the dust of water absorbing agent.
The liquid diffusion rate of water absorbing agent is preferably 0.2mm/ second to 10.0mm/ second (containing), and more preferably 0.5mm/ second is to 10.0mm/ second (containing), in addition more preferably 0.8mm/ second to 10.0mm/ second (containing).
Correspondingly, the efficient liquid rate ground diffusion of water absorbing agent absorption.This has improved liquid-absorbent rate and the liquid diffusivity of water absorbent core of the time per unit of water absorbent core.Thereby, improved water absorbing capacity.
Plant component A1, chelating agent B1, other substance C 1 etc. can be added into water absorbing agent with very little amount to give the particulate water-absorbing agent different functions.
The amount of the additive A of using 1 to C1 can be according to the changes of function of object and increase.Usually, one of examples of such additives can be added with 0 to 10 mass parts with respect to 100 mass parts water absorbing agents, is preferably 0.001 to 5 mass parts, more preferably 0.002 to 3 mass parts.Usually, if amount is less than 0.001 mass parts, can not obtain the enough effects or the function of increase.If amount is 10 mass parts or more, the effect of acquisition can not be proportional with the amount of adding, or absorbability possibly reduce.
Plant component A1
The particulate water-absorbing agent of embodiment of the present invention can mix with plant component makes that water absorbing agent can deodorization.The preferred proportion of the plant component that mixes as stated.The plant component that can be used for embodiment of the present invention is preferably plant powder itself or plant extracts.Compound in the plant component is preferably at least a compound and caffeine or at least a compound that is selected from tannin, tannic acid, nutgall, Chinese gall and gallic acid that is selected from polyphenol, flavones and similar substance.As an example, at United States Patent (USP) 6,469,080, find to have instance in European patent 1352927 and the international application announced according to PCTWO2003/104349.The example that is mixed for the form of the plant component among the present invention comprises Essence (essential oil etc.), plant itself (plant powder etc.), plant rubbish and rubbish extract from plant extract, and said plant rubbish and rubbish extract are the byproduct in the manufacture process of plant processing industry and food-processing industry.
The particle diameter of the pulvis of the plant component A1 that provides with powder form and/or loading contain from the particle diameter of the pulvis of the Essence (essential oil) of the plant component A1 of plant extract and are generally from 0.001 μ m to 1, and 000 μ m is preferably from 1 μ m to 600 μ m.The quality average particle size particle size that contains the particle of plant component is preferably 500 μ m or littler, more preferably 300 μ m or littler.If the quality average particle size particle size is greater than 500 μ m, when contacting with urine, the active ingredient in the plant component can not work fully, may not obtain stable deodorizing capability.The quality average particle size particle size preferably less than the quality average particle size particle size of water-absorbing resin to obtain excellent deodorizing capability and stability.The example that contains the particle of plant component comprises plant powder of being processed by plant itself and the pelleted substrate that loads plant component.The example of examples of such carriers comprises that those contain from the loading Essence (essential oil) of the plant component of plant extract.Plant component can be used for form that the plant component in the embodiment of the present invention preferably adopts the liquid and/or the aqueous solution at normal temperature so that can be easy to be added into water-absorbing resin.
The interpolation of chelating agent B1
Preferably, mix chelating agent, particularly mix polyvalent carboxylic acid and salt thereof to obtain the particulate water-absorbing agent of embodiment of the present invention.
The chelating agent that can be used for the particulate water-absorbing agent of embodiment of the present invention is preferably a kind of chelating agent with high Fe or Cu sequester or sequestering power: promptly; About the stability constant of Fe ion is 10 or higher chelating agent; Be preferably 20 or higher; More preferably amino polyvalent carboxylic acid and salt thereof, even more preferably have the amino carboxylic acid and the salt thereof of three or more carboxyls.
Particularly; The polyvalent carboxylic acid is diethylene-triamine pentaacetic acid, teiethylene tetramine-hexacetic acid, cyclohexane-1,2-ethylenediamine tetraacetic acid (EDTA), N-ethoxy ethylene diamin(e) triacetic acid, ethylene glycol diethyl ether ethylenediamine tetraacetic acid (EDTA), ethylene diamin(e) four propionic acid acetate, N-alkyl-N '-carboxyl methylaspartic acid, N-thiazolinyl-N '-carboxyl methylaspartic acid and alkali metal salt, alkali salt, ammonium salt and amine salt.Wherein most preferred is diethylene-triamine pentaacetic acid, teiethylene tetramine-hexacetic acid, N-ethoxy ethylene diamin(e) triacetic acid and salt thereof.
Other substance C 1
If can obtain the particulate water-absorbing agent of embodiment of the present invention, can add or not add various additives, for example antiseptic, water-soluble polymer, insoluble polymer, water, surfactant, organic fine grained.
The water absorbing agent of embodiment of the present invention contains the water absorbing resin particle that can contain or not contain multivalent metal salt and water-insoluble inorganic particle.Particularly, the water absorbing agent of embodiment of the present invention can contain the water absorbing resin particle through the polymerization acquisition of water-soluble unsaturated monomer.Said water absorbing agent satisfies following condition (A) to (D):
(A) said particle near surface crosslinked have or be coated with have monohydroxy at least surface crosslinking agent;
(B) said particle at least from the teeth outwards or near surface contain multivalent metal salt and water-insoluble inorganic particle;
(C) the quality average particle size particle size of said water absorbing agent is 200 μ m to 500 μ m (containing); And
(D) said water absorbing agent contains 5 quality % or lower and has the particle of size that can be of a size of the sieve of 150-μ m through aperture openings.
Water absorbing resin particle in the water absorbing agent is through having the crosslinked or coating near surface of monohydroxy at least surface crosslinking agent.Be included in the water absorbing agent water-absorbing resin as stated, crosslinked or apply through having monohydroxy at least surface crosslinking agent near surface.When the water absorbing agent that expands places pressure following time, it has reduced the amount of the liquid that possibly ooze out.Therefore, increased absorbability or the AAP under the pressure.
The water absorbing resin particle that water absorbing agent obtains except the polymerization that contains through water-soluble unsaturated monomer and (A) to the condition of (D) is not subject to any specific mode.For example, water absorbing agent can be subject to above-mentioned with satisfy condition (a) to the relevant scope of the water absorbing agent of (d).In addition, condition (A) to (D) can be contracted to description with satisfy condition (a) to the relevant scope of the water absorbing agent of (d), to give the water absorbing agent excellent physical characteristics.
Satisfy condition (A) to (D) water absorbing agent preferably contain the water-insoluble inorganic particle.Said proportion of particles with respect to water absorbing agent is preferably from 0.001 quality % to 5 quality % (containing); More preferably from 0.01 quality % to 3 quality % (containing); Even more preferably from 0.01 quality % to 1 quality % (containing); Also, most preferably be from 0.05 quality % to 0.4 quality % (containing) more preferably from 0.01 quality % to 0.4 quality % (containing).The upper and lower bound that can suitably combine said number range.Preferred number range, as an example, for from 0.01 quality % to 0.4 quality % (containing).As stated, the water-insoluble inorganic particle is included on the surface of water absorbing agent or near surface at least.This has improved salt solution water conservancy diversion rate and powder fluidity when high humility.In addition, above-mentioned multivalent metal salt also remains on the surface of water absorbing agent particle or near surface at least.The cooperative effect of water-insoluble inorganic particle and multivalent metal salt has further improved the physical characteristic of the water absorbing agent that produces.
The absorbability of water absorbing agent under the pressure of 4.83kPa (AAP) is preferably 16g/g or more.Though maximum is not subject to any specific mode, be preferably 30g/g or still less.If the absorbability under the pressure of 4.83kPa (AAP) is lower than 16g/g, when the water absorbing agent that produces was used for water absorbent core, water absorbent core placed pressure following time, possibly cause the liquid infiltration of high relatively level, or " wetting again ".
The preparation method of water absorbing agent
The method (preparation method A) of the water absorbing agent of preparation embodiment of the present invention is the method that a kind of preparation contains the water absorbing agent of water absorbing resin particle, and said water absorbing resin particle has the internal crosslinking structure through the polymerization acquisition of water-soluble unsaturated monomer.In said method, water absorbing resin particle mixes with the water-insoluble inorganic particle before or after crosslinked when surface-crosslinked or said.Resin particle and organic surface crosslinking agent and/or water-soluble inorganic surface crosslinking agent are crosslinked near surface.The quality average particle size particle size of resin particle is 200 μ m to 500 μ m.Resin particle contains 5 quality % or lower and has the particle of size that can be of a size of the sieve of 150 μ m through aperture openings.Inorganic particle has the functional group that can form ionic bond with the lip-deep functional group of water absorbing resin particle at least in its surface.
The water absorbing resin particle of method that is used for preparing the water absorbing agent of embodiment of the present invention is preferably above-mentioned water absorbing resin particle.In addition, the water-insoluble inorganic particle of method that is used for preparing the water absorbing agent of embodiment of the present invention is preferably above-mentioned water-insoluble inorganic particle.
In the method for water absorbing agent of preparation embodiment of the present invention, the amount of the water-insoluble inorganic particle of interpolation is 1ppm to 10 with respect to the water absorbing agent particle, 000ppm, 5ppm to 1 more preferably, 500ppm, most preferably 10ppm to 990ppm.If contain too many water-insoluble inorganic particle,, may cause safety/hygienic issues, or make the performance degradation of water absorbent core because fine grained possibly wave in the process of preparation water absorbent core.In addition, when the water absorbing agent that produces is used for water absorbent core, possibly make water absorbent core not demonstrate excellent vertical liquid absorption capacity (being fixed height absorption ability (FHA)).
The most preferred form for preparing the method for water absorbing agent comprises the step that the solution (being preferably the aqueous solution) with at least a three value water-soluble multivalent metal salts mixes with water absorbing resin particle and the step of the insoluble inorganic particle of mixing water.
The water absorbing agent that can have the internal crosslinking structure through preparation, contains the water absorbing resin particle that the polymerization through water-soluble unsaturated monomer obtains prepares the water absorbing agent of embodiment of the present invention.Said water absorbing resin particle and surface crosslinking agent are crosslinked near surface.The quality average particle size particle size of water absorbing resin particle is 200 μ m to 500 μ m (containing).The concentration of residual silanol group is 1.7SiOH/nm 2Or lower silica be 0ppm to 1 based on the resin particle amount, the water absorbing resin particle of 900ppm mixes, and mixes being selected from the time that comprises following group at least: when surface crosslinking agent is crosslinked, before crosslinked and after crosslinked.This method is called as preparation method B.
In the method (preparation method B) of the water absorbing agent for preparing embodiment of the present invention, water absorbing resin particle is at first crosslinked near surface and surface crosslinking agent.Can use title is surface crosslinking agent and the method that " water absorbing resin particle " item is mentioned down.
The time of mixed silica or other water-insoluble inorganic particle and water absorbing resin particle can be selected from the group that comprises the following time at least: when surface crosslinking agent is crosslinked, before crosslinked and after crosslinked.The said time is not subject to any specific mode.The said time is preferably after crosslinked, more preferably in crosslinked back and when mechanically damaging particle.
In preparation method A, B; The concrete grammar of mixed silica or other water-insoluble inorganic particle and water absorbing resin particle can use any known agitating device: can enumerate some examples, oar blender, ribbon blender, rotary blender, cylinder formula rotating cylinder (jar tumbler), browse formula blender (browser mixer), sand oar mixer.These agitating devices can comprise the heater of the mixture of heating water absorbing resin particle and water-insoluble inorganic particle, can also comprise the cooling device of cooling by the warmed-up mixture of heater.
Though mixing time is not subject to any specific mode, is preferably 60 minutes or shorter, more preferably 30 minutes or shorter.
Because water absorbing resin particle and silica or other water-insoluble inorganic particle are dry liquid concentrates, it is important assembling when therefore preventing its mixture.Therefore, when the water-insoluble inorganic particle mixes with water absorbing resin particle or after mixing, preferred said water-insoluble inorganic particle of pneumatic transportation and water absorbing resin particle.Pneumatic transportation has stoped the gathering of water absorbing resin particle and silica or other water-insoluble inorganic particle.Therefore, silica or other water-insoluble inorganic particle can mix with water absorbing resin particle equably.The physical characteristic of the water absorbing agent that obtains has obtained enhancing.
In said preparation method (preparation method A, B); Multivalent metal salt and water absorbing resin particle preferably at least with surface crosslinking agent when crosslinked, before crosslinked or crosslinked back mixed, to prepare the water absorbing agent of a kind of centrifugal water holding capacity and salt solution water conservancy diversion rate excellence balanced.
Based on water absorbing resin particle, the amount of the multivalent metal salt of use is preferably from 0.001 quality % to 5 quality % (containing), more preferably from 0.01 quality % to 1 quality % (containing).
When mixing multivalent metal salt, said salt is preferably with aqueous solution.With respect to saturated concentration; The concentration that contains the water-soluble multivalent metal salt in the aqueous solution of multivalent metal salt is preferably 50% or higher; More preferably 60% or higher, even more preferably 70% or higher, also more preferably 80% or higher; Also more preferably 90% or higher, to stop infiltration and to diffuse in the water absorbing resin particle.Certainly use said salt in saturated concentration.In addition, above-mentioned hydrophilic organic solvent and organic acid (or its salt), for example lactic acid (or its salt) can be present in the aqueous solution that contains said multivalent metal salt at least together.Owing to has limited the polyvalent metal salt penetration at least and diffused in the water absorbing resin particle, and salt has obtained mixing better therefore preferred hydrophilic organic solvent and organic acid coexistence.
Be not subject to any specific mode though mix the agitating device of multivalent metal salt, it can be one of above-mentioned agitating device that is used in the water-insoluble inorganic particle.The situation that also can be similar to above-mentioned water-insoluble inorganic particle is specified mixing time.
In preparing the method for water absorbing agent, silica or other water-insoluble inorganic particle preferably mix after the water absorbing resin particle mechanical damage with water absorbing resin particle, to pulverize water absorbing resin particle brokenly.Because water absorbing resin particle is pulverized brokenly, silica or other water-insoluble inorganic particle can be included on the surface of water absorbing resin particle or near surface effectively at least, and have improved the physical characteristic of gained water absorbing agent.
Mechanical damage refers to collision water absorbing resin particles such as glass, metals to produce physical impact.
As long as water absorbing resin particle is impacted, can bestow mechanical damage to water absorbing resin particle through any way.For example, can shake be placed with water absorbing resin particle and glass bead glass container to bestow mechanical damage (coating vibration-testing (paint shaker test), hereinafter will further describe).Other method of water absorbing resin particle being bestowed mechanical damage comprises: a kind of water absorbing resin particle is placed the method (ball milling) of hydrostatic column and rotary container with bead; A kind of in the agitator of paddle is housed stirring method; A kind of method through blade dryer (heater/cooler of oar is housed); A kind of in milling apparatus abrasive method; A kind of method of pneumatic transportation; And a kind of method that makes the water absorbing agent particle collide each other or rub.
In addition; In order to obtain a kind of water absorbing agent with excellent SFC; Particularly preferably in the crosslinked back of particle surface water absorbing resin particle is bestowed mechanical damage, pulverized particles is mixed the water absorbing resin particle of pulverizing with multivalent metal salt; And then water absorbing resin particle bestowed mechanical damage, and add silica or other water-insoluble inorganic particle.
The water absorbing agent that can prepare embodiment of the present invention by the method that preparation contains the water absorbing resin particle that the polymerization through water-soluble unsaturated monomer obtains.Said water absorbing resin particle is through having the crosslinked or coating near surface of monohydroxy at least surface crosslinking agent, and the quality average particle size particle size of water absorbing resin particle is 200 μ m to 500 μ m (containing).Water absorbing resin particle crosslinked through surface crosslinking agent or apply after, multivalent metal salt and water-insoluble inorganic particle and water absorbing resin particle.This method is called preparation method C.
In the preparation method, water absorbing resin particle is at first through having the crosslinked or coating near surface of monohydroxy at least surface crosslinking agent.Surface crosslinking agent and the method that can use title " water absorbing resin particle " item to mention down.
Except cross-linking step, can implement the step of preparation method C through the corresponding steps of above-mentioned preparation method A, B.
Water absorbent core
The water absorbent core of embodiment of the present invention comprises above-mentioned water absorbing agent.For example, when said water absorbent core was used in combination with a kind of suitable material, it was suitable as the water accepting layer in cleaning/hygienic material.Hereinafter will be described water absorbent core.
Water absorbent core is the molding compounds of being processed by water absorbing agent and other material.This core is used in disposable diaper, sanitary napkin, incontinence protection, medical protection pad and the similar cleaning/hygienic material to absorb blood, body fluid, urine etc.One of other material that uses is exemplified as cellulose fibre.The specific embodiment of cellulose fibre comprises the mechanical pulp that makes from timber; Wooden paper pulp fiber such as chemical pulp, semichemical wood pulp and soluble pulp; Man-made cellulose fibers such as staple fibre and cellulose acetate.The optimum fiber cellulose fiber is a wood pulp cellulose, and cellulose fibre can partly comprise nylon, polyester fiber or other synthetic fibers.When the water absorbing agent of embodiment of the present invention during as the part water absorbent core, the quality optimization that is included in the water absorbing agent in the water absorbent core is 20 quality % or more, 30 quality % or more more preferably, even 40 quality % or more more preferably.Be lower than 20 quality % if be included in the quality of the water absorbing agent of the present invention in the water absorbent core, cannot obtain enough effects so.
Water absorbing agent and cellulose fibre that a kind of method known, that be fit to that is used to prepare water absorbent core can be chosen as by embodiment of the present invention prepare water absorbent core.For example, water absorbing agent can be sprayed on the thin slice of being processed by cellulose fibre or mat, can press from both sides more water absorbing agent betwixt if desired.Selectively, cellulose fibre mixes with water absorbing agent equably.A kind of preferable methods is that cellulose fibre and water absorbing agent are done mixed and compressed mixture.This method can suppress water absorbing agent well and drop from cellulose fibre.Preferably, being compressed in 50 ℃ to 200 ℃ (containing) heating carries out.At United States Patent (USP) 5,849, other method for optimizing of preparation water absorbent core has been described in 405 specification and the U.S. Patent application of announcement 2003/060112.
When the water absorbing agent of embodiment of the present invention was used for water absorbent core, it demonstrated excellent physical characteristics; The water absorbent core that produces has very excellent quality: it can promptly absorb liquid, only stays small amount of liquid in its surface.
The water absorbing agent of embodiment of the present invention has the excellent water-absorbing characteristic, therefore can be used as the water absorbing agent/water-loss reducer of multiple purpose: for example, be used for the water absorbing agent/water-loss reducer of water absorbing agent article, for example disposable diaper, sanitary napkin, incontinence protection, medical protection pad; The agricultural/horticultural water-loss reducer, for example sphagna substitute, the agent of soil modification and improvement, water-loss reducer and agricultural effectiveness continue agent; Such as the for building water-loss reducer of interior dress wall material with anti-agglomerating agent and cement additire; Release control agent; Cold-retaining agent; Disposable body warmer (disposable pocket stoves); The mud coagulating agent; Shelflife-improving agent for food; The ion-exchange column material; The dehydrating agent of mud/oil; Drier; And humidity adjustment agent.In addition, the water absorbing agent of embodiment of the present invention can be particularly suitable for absorbing the disposable diaper, sanitary napkin of excrement, urine or blood and similar cleaning/hygienic material.
When water absorbent core is used for such as cleaning/hygienic materials such as disposable diaper, sanitary napkin, incontinence protection and medical protection pads; Water absorbent core preferably be placed on permeability for liquids top-sheet that (a) contact user health is configured with (b) away from user's health, contact user clothing be configured between the sheet material of the impermeable back of liquid.Water absorbent core can be multilayer (two-layer or more than two-layer).In addition, as an example, water absorbent core can use with pulp layer.
Described like preceding text, in other words, the water absorbing agent of embodiment of the present invention is the water absorbing agent of the water absorbing resin particle with internal crosslinking structure that obtains of a kind of polymerization that contains through water-soluble unsaturated monomer.Said water absorbing resin particle is crosslinked at its near surface and surface crosslinking agent.Water absorbing resin particle at least from the teeth outwards or near surface contain silica.The concentration of the residual silanol group that silica has in its surface is 1.7SiOH/nm 2Or it is lower.Water absorbing resin particle contains 10ppm to 1, the silica of 900ppm (containing).The quality average particle size particle size of water absorbing agent is 200 μ m to 500 μ m (containing).Water absorbing agent contains 5 quality % or lower and has the particle of size that can be of a size of the sieve of 150 μ m through aperture openings.
According to said arrangement, the water absorbing resin particle in the water absorbing agent is crosslinked at its near surface and surface crosslinking agent.When the water absorbing agent that expands places pressure following time, it has reduced the amount of the liquid that possibly ooze out.In other words, increased absorbability under the 4.83kPa pressure.In addition, water absorbing resin particle at least from the teeth outwards or near surface contain silica.Because silica has the excellent liquid permeability, so the permeability for liquids that is improved of water absorbing agent.
In addition, because the strong thing that forms of limited hydrogen in the scope of appointment, only possibly take place the concentration of the residual silanol group in the silica by inference, it has suppressed the gathering of silica.In other words, the gathering and the diffusion of silica have been suppressed.Therefore, technological different with routine are even use silica, because the gathering of silica has stoped the generation of dust.In addition, the content of silica is in the scope of appointment.Therefore, the water absorbing agent of generation has the dust that excellent physical characteristics and amount have reduced.Can account for 5 quality % or lower of the whole water absorbing agent quality of acquisition through the particle of size that aperture openings is of a size of the sieve of 150 μ m.Because the reduction of fine particle content in the water absorbing agent, dust is given birth to limited volume production.
Therefore, the water absorbing agent of generation has following characteristics.In the preparation process of water absorbing agent, the silica in the water absorbing agent will can not wave to air with other particle, can not cause safety/hygienic issues.In addition, the physical characteristic of the water absorbent core of generation can not demoted yet.In addition, because the quality average particle size particle size of water absorbing agent in the scope of appointment, is used to absorb the permeability for liquids of liquid etc. is not interfered; Water absorbing agent has high permeability for liquids.
Based on water absorbing agent, water absorbing agent preferably at least on the surface of water absorbing resin particle or the near surface amount be the multivalent metal salt of 0.001 quality % to 5 quality % (containing).
Correspondingly, water absorbing agent contains multivalent metal salt (being preferably three value water-soluble multivalent metal salts).Therefore, the salt solution water conservancy diversion rate or the fixed height absorption ability that when the water imbibition that does not reduce in large quantities under the 4.83kPa pressure, are improved of water absorbing agent.In addition, when not having silica, at least on the surface of water absorbing agent or near surface remedied the replacing of the deficiency of silica.In addition, the cooperative effect of silica and multivalent metal salt makes water absorbing agent have better physical characteristic.
Water absorbing agent is preferably after surface-crosslinked and makes the water absorbing resin particle mechanical damage.
Correspondingly, water absorbing resin particle has the shape of pulverizing brokenly.Therefore, silica can comprise from the teeth outwards or near surface effectively at least.
The concentration that water absorbing agent is preferably the residual silanol group on silica surface is from 0.7SiOH/nm 2To 1.7SiOH/nm 2(containing).
Correspondingly, silica is hydrophobic within bounds, but suitably hydrophobic.This has stoped the reduction of the liquid diffusion rate of the water absorbing agent that obtains.
The liquid diffusion rate of water absorbing agent be preferably from 0.2 (mm/ second) to 10.0 (mm/ second) (containing).Said speed more preferably from 0.5 (mm/ second) to 10.0 (mm/ second) (containing), even more preferably from 0.8 (mm/ second) to 10.0 (mm/ second) (containing).
Correspondingly, the efficient liquid rate ground diffusion of water absorbing agent absorption.This has improved liquid-absorbent rate and the liquid diffusivity in the water absorbent core of the time per unit of water absorbent core.Thereby, improved water absorbing capacity.
Calculate in mass, water absorbing agent preferably contains 300ppm or dust still less.
Therefore, the water absorbing agent of generation even contain the dust of lower amount.Silica in the water absorbing agent will can not wave with other particle, can not cause safety/hygienic issues.The physical characteristic of water absorbing agent can not demoted yet.
Water absorbing agent preferably has negative triboelectric charge.
This has stoped the gathering of silica and water absorbing agent, comes off from water absorbing resin particle thereby suppressed silica.Therefore, the Dust Capacity that contains of water absorbing agent has reduced.
Water absorbent core is characterised in that it contains said water absorbing agent.
Therefore, the water absorbent core of generation has the dust that high-caliber physical characteristic and amount have reduced.
In other words, the method for water absorbing agent of preparation embodiment of the present invention is the method that a kind of preparation contains the water absorbing agent of the water absorbing resin particle with internal crosslinking structure that the polymerization through water-soluble unsaturated monomer obtains.Said method comprises that to make water absorbing resin particle crosslinked at its near surface and surface crosslinking agent.The quality average particle size particle size of water absorbing resin particle is 200 μ m to 500 μ m (containing).Said method also comprises mixes silica and water absorbing resin particle being selected from the time that comprises following group at least: when surface crosslinking agent is crosslinked, before crosslinked and after crosslinked.The amount of the silica that mixes in the water absorbing resin particle is that the concentration of the residual silanol group that 900ppm (containing), silica contain is 1.7SiOH/nm from 10ppm to 1 2Or it is lower.
According to said method, silica mixes with water absorbing resin particle.The water absorbing agent that makes has high-caliber physical characteristic, and the dust that reduced of packet content.
The said method for preparing water absorbing agent is preferably silica and after the water absorbing resin particle mechanical damage, mixes with water absorbing resin particle.
Correspondingly, silica mixes with water absorbing resin particle after particle is ground into irregular shape.Silica can be included on the surface of water absorbing resin particle or near surface effectively at least.The water absorbing agent that produces has the physical characteristic of improvement.
The method for preparing water absorbing agent be preferably multivalent metal salt at least when surface crosslinking agent is crosslinked, before crosslinked or after crosslinked, mix with water absorbing resin particle.
Correspondingly, water absorbing agent contains multivalent metal salt (being preferably three value water-soluble multivalent metal salts).Therefore, the salt solution water conservancy diversion rate or the fixed height absorption ability that when the water imbibition that does not reduce in large quantities under the 4.83kPa pressure, are improved of water absorbing agent.In addition, when not having silica, at least on the surface of water absorbing agent or near surface remedied the replacing of the deficiency of silica.In addition, the cooperative effect of silica and multivalent metal salt makes water absorbing agent have better physical characteristic.
The method for preparing water absorbing agent preferably includes when silica mixes with water absorbing resin particle or pneumatic transportation silica and water absorbing resin particle after mixing.
Correspondingly, the mixture through further mixed silica of pneumatic transportation and water absorbing resin particle.Do not assemble.Silica more effectively mixes with water absorbing resin particle.Therefore, silica mixes with water absorbing resin particle equably.This has improved the physical characteristic of the water absorbing agent that obtains.
In other words, the water absorbing agent of embodiment of the present invention contains the water absorbing resin particle with internal crosslinking structure through the polymerization acquisition of water-soluble unsaturated monomer.Said water absorbing resin particle is crosslinked near surface and organic surface crosslinking agent and/or water-soluble inorganic surface crosslinking agent.The quality average particle size particle size of water absorbing agent is 200 μ m to 500 μ m.Water absorbing agent contains 5 quality % or lower and has the particle of size that can be of a size of the sieve of 150 μ m through aperture openings.Water absorbing agent contains at least from the teeth outwards and has the water-insoluble fine inorganic particles that can form the functional group of ionic bond with the lip-deep functional group of water absorbing resin particle.The water-insoluble fine inorganic particles remain on the surface of water absorbing resin particle or near.
It is carboxyl that water absorbing agent is preferably the lip-deep functional group of water absorbing resin particle, and the lip-deep functional group at the water-insoluble fine inorganic particles is amino at least.
Water absorbing agent is preferably water absorbing resin particle and comprises the particle with cavernous structure.
When the water absorbing agent that contains water-absorbing resin and inorganic powder that was rendered as for from 7 to 10 (containing) as pH was dispersed in the liquid, the specific area that records through known BET (japanese unexamined patent publication (spy opens) 2000-93792) was 50cm 2/ g.Because this technology is not controlled the particle size or the fine grain quantity of water-absorbing resin, this technology can not solve the problem that is solved by the present invention.In addition, water-absorbing resin does not have enough permeabilitys for liquids; Water absorbent core does not demonstrate enough liquid-absorbent rates of time per unit.
In other words, the method for water absorbing agent of preparation embodiment of the present invention is the method that a kind of preparation contains the water absorbing agent of the water absorbing resin particle with internal crosslinking structure that the polymerization through water-soluble unsaturated monomer obtains.Said method comprises mixes water absorbing resin particle with the water-insoluble fine inorganic particles.Said water absorbing resin particle is crosslinked near surface and organic surface crosslinking agent and/or water-soluble inorganic surface crosslinking agent.The quality average particle size particle size of particle is 200 μ m to 500 μ m.Particle contains 5 quality % or lower and has the particle of size that can be of a size of the sieve of 150 μ m through aperture openings.The water-insoluble fine inorganic particles contains at least from the teeth outwards and has the functional group that can form ionic bond with the lip-deep functional group of water absorbing resin particle.When water absorbing resin particle is surface-crosslinked, or before step in or in follow-up step, mix.
Said preparation method is preferably through water absorbing resin particle is mixed and add hot mixt with organic surface crosslinking agent and/or water-soluble inorganic surface crosslinking agent and makes water absorbing resin particle crosslinked.Based on water absorbing resin particle, said crosslinking agent amount is preferably persulfate from the water-soluble inorganic salt of 0.01 quality % to 1.0 quality %.
Said preparation method is preferably through water absorbing resin particle is mixed and add hot mixt with organic surface crosslinking agent and/or water-soluble inorganic surface crosslinking agent and makes water absorbing resin particle crosslinked.The boiling point of hydrophilic organic solvent is 100 ℃ or lower, and does not contain hydrophilic organic solvent.
Said preparation method is preferably with 10 to 990ppm amount and adds the water-insoluble fine inorganic particles.
Said preparation method preferably also is included in when surface-crosslinked, or before step in or in follow-up step, the three value water-soluble multivalent metal salts of water absorbing resin particle with at least 0.0001 quality % to 5 quality % are mixed.
Said preparation method is preferably incorporated in the step of mixing transportation water-absorbing resin in back with the water-insoluble fine inorganic particles.
According to said arrangement; In the preparation of water absorbent core, even contain the water-insoluble fine inorganic particles, the water absorbing agent of generation makes fine grained can not wave with the method for preparing water absorbing agent; Can not cause safety/hygienic issues, and the physical characteristic of water absorbent core does not reduce.
In addition, according to said arrangement, the water absorbing agent of generation has excellent centrifugal water holding capacity (CRC) and/or salt solution water conservancy diversion rate (SFC), and it representes the amount of water absorbing agent absorption and the permeability for liquids of water absorbing agent respectively.Therefore, the water absorbing agent of generation makes water absorbent core have the excellent liquid absorptivity of time per unit with the method for preparing water absorbing agent.In addition, according to said arrangement, the water absorbing agent of generation has an equilibrium valve between the centrifugal water holding capacity (CRC) of excellence and the infiltrative salt solution water conservancy diversion of express liquid rate (SFC).Therefore, the water absorbing agent of generation makes water absorbent core have the excellent liquid absorptivity of time per unit with the method for preparing water absorbing agent.
In addition, according to said arrangement, the water absorbing agent of generation makes when water absorbing agent is used for water absorbent core with the method for preparing water absorbing agent, gives the excellent vertical liquid absorption capacity of water absorbent core (that is the fixed height absorption ability (FHA) of excellence).
According to said arrangement, the water absorbing agent of generation has excellent absorbability under the pressure of 4.83kPa (AAP).Therefore, when water absorbent core places pressure following time, the water absorbing agent of generation makes its limited liquid permeate with the method that prepare water absorbing agent, or " wetting again ".
In other words, the water absorbing agent of embodiment of the present invention is characterised in that it is the water absorbing agent of the water absorbing resin particle with internal crosslinking structure that obtains of a kind of polymerization that contains through water-soluble unsaturated monomer.Said water absorbing agent also has following characteristics.Water absorbing resin particle is near surface and have the crosslinked or coating of monohydroxy at least surface crosslinking agent.Water absorbing resin particle at least from the teeth outwards or near surface contain multivalent metal salt and water-insoluble inorganic particle.The quality average particle size particle size of water absorbing agent is 200 μ m to 500 μ m (containing).Water absorbing agent contains 5 quality % or lower and has the particle of size that can be of a size of the sieve of 150 μ m through aperture openings.
According to said arrangement, the water absorbing resin particle in the water absorbing agent is near surface and surface crosslinking agent is crosslinked or coating.When the water absorbing agent that expands places pressure following time, it has reduced the amount of the liquid that possibly ooze out.In other words, increased absorbability under the 4.83kPa pressure.In addition, water absorbing resin particle at least from the teeth outwards or near surface contain multivalent metal salt and water-insoluble inorganic particle.The water-insoluble inorganic particle has the excellent liquid permeability.Therefore, water absorbing agent has the permeability for liquids of improvement.
In addition, multivalent metal salt and water-insoluble inorganic particle all remain on the surface of water absorbing resin particle or near surface at least.Therefore, can infer through static reaction, have the coordinate bond of polyvalent metal and suppressed the water-insoluble inorganic particle and wave by the numerator mediated coordinate bond of water in air and hydrogen are strong.Therefore, technological different with routine even use the water-insoluble inorganic particle, also can stop because the generation dust that waves of water-insoluble inorganic particle.In addition, the amount of water-insoluble inorganic particle is in the scope of appointment.Therefore, the water absorbing agent of generation has the dust that excellent physical characteristics and amount have reduced.Can account for 5 quality % or lower of the whole water absorbing agent quality of acquisition through the particle of size that aperture openings is of a size of the sieve of 150 μ m.Because the reduction of fine particle content in the water absorbing agent, dust is given birth to limited volume production.
Therefore, the water absorbing agent of generation has following characteristics.In the preparation process of water absorbing agent, the water-insoluble inorganic particle in the water absorbing agent will can not wave with other particle, can not cause safety/hygienic issues.In addition, the physical characteristic of water absorbent core can not demoted yet.In addition, because the quality average particle size particle size of water absorbing agent in the scope of appointment, is used to absorb the permeability for liquids of liquid etc. is not interfered; Water absorbing agent has high permeability for liquids.
Based on water absorbing agent, water absorbing agent preferably at least on the surface of water absorbing resin particle or the near surface amount be the multivalent metal salt of 0.001 quality % to 5 quality % (containing).
Correspondingly, the water absorbing agent of generation contains multivalent metal salt (being preferably three value water-soluble multivalent metal salts).Therefore, the salt solution water conservancy diversion rate or the fixed height absorption ability that when the water imbibition that does not reduce in large quantities under the 4.83kPa pressure, are improved of water absorbing agent.In addition, when not having the water-insoluble inorganic particle, at least on the surface of water absorbing agent or near surface remedied the deficiency of water-insoluble inorganic particle.In addition, the cooperative effect of water-insoluble inorganic particle and multivalent metal salt makes water absorbing agent have better physical characteristic.
Said water absorbing agent is preferably such that the water-insoluble inorganic particle is a silica.
Correspondingly, remain on the surface of water absorbing resin particle at least or interaction that the multivalent metal salt of near surface and the silanol group that remains on the silica surface take place.This has limited the amount of dust effectively.
Water absorbing agent is preferably after surface-crosslinked and makes the water absorbing resin particle mechanical damage.
Correspondingly, water absorbing resin particle has the shape of pulverizing brokenly.Therefore, the water-insoluble inorganic particle can comprise from the teeth outwards or near surface effectively at least.
Water absorbing agent preferably has the centrifugal water holding capacity and 10 (10 of 30g/g (containing) -7Cm 3Sg -1) or higher salt solution water conservancy diversion rate.
Correspondingly, the water absorbing agent of generation has the excellent balance value between centrifugal water holding capacity and salt solution water conservancy diversion rate.
Water absorbing agent preferably has 16g/g to the 30g/g water absorbing capacity of (containing) under 4.83kPa pressure.
Correspondingly, the liquid that reduced of water absorbing agent discharge under 4.83kPa pressure.In actual use, the water absorbent core of generation can only ooze out a spot of liquid.
Water absorbing agent is preferably such that the particle size distribution of water absorbing agent has the logstandard deviation of 0.20 to 0.40 (containing).
Correspondingly, particle size distribution is narrow.This has stoped the liquid-absorbent rate of time per unit of permeability for liquids and the water absorbent core of water absorbing agent to reduce significantly.
Calculate in mass, water absorbing agent preferably contains 400ppm or dust still less.
Therefore, the water absorbing agent of generation can even contain the dust of lower amount.Water-insoluble inorganic particle in the water absorbing agent will can not wave with other particle, can not cause safety/hygienic issues.The physical characteristic of water absorbing agent can not demoted yet.
In other words, the water absorbing agent of embodiment of the present invention is characterised in that it contains said water absorbing agent.
Therefore, the water absorbent core of generation has the dust that high-caliber physical characteristic and amount have reduced.
In other words, the method for water absorbing agent of preparation embodiment of the present invention is characterised in that it is the method that a kind of preparation contains the water absorbing agent of the water absorbing resin particle with internal crosslinking structure that the polymerization through water-soluble unsaturated monomer obtains.The characteristic of said method also be it comprise water absorbing resin particle (the quality average particle size particle size is 200 μ m to 500 μ m (containing)) near surface with to contain monohydroxy at least surface crosslinking agent crosslinked or apply; And after or coating crosslinked, mix water absorbing resin particle and water-insoluble inorganic particle with multivalent metal salt with surface crosslinking agent.
According to said method, the water-insoluble inorganic particle mixes with water absorbing resin particle and multivalent metal salt.The water absorbing agent that makes has high-caliber physical characteristic, and the dust that reduced of packet content.
The said method for preparing water absorbing agent is preferably and makes water absorbing resin particle after mechanical damage, mix with multivalent metal salt and water-insoluble inorganic particle.
Correspondingly, after pulverizing brokenly, water absorbing resin particle mixes with multivalent metal salt and water-insoluble inorganic particle.Therefore, multivalent metal salt and water-insoluble inorganic particle can be included on the surface of water absorbing resin particle or near surface effectively at least.The water absorbing agent that produces has the physical characteristic of improvement.
The method for preparing water absorbing agent be preferably make water absorbing resin particle before mix with multivalent metal salt with to contain monohydroxy surface crosslinking agent at least crosslinked or apply.
Correspondingly, the water absorbing agent of generation contains multivalent metal salt (being preferably three value water-soluble multivalent metal salts).Therefore, the salt solution water conservancy diversion rate or the fixed height absorption ability that when the water imbibition that does not reduce in large quantities under the 4.83kPa pressure, are improved of water absorbing agent.In addition, when not having the water-insoluble inorganic particle, at least on the surface of water absorbing agent or near surface remedied the replacing of the deficiency of water-insoluble inorganic particle.In addition, the cooperative effect of water-insoluble inorganic particle and multivalent metal salt makes water absorbing agent have better physical characteristic.
The said method for preparing water absorbing agent preferably includes when the water-insoluble inorganic particle mixes with water absorbing resin particle or mixes back said water-insoluble inorganic particle of pneumatic transportation and water absorbing resin particle.
Correspondingly, the mixture through insoluble inorganic particle of the further mixing water of pneumatic transportation and water absorbing resin particle.Do not assemble.The water-insoluble inorganic particle more effectively mixes with water absorbing resin particle.Therefore, the water-insoluble inorganic particle mixes with water absorbing resin particle more equably.This has improved the physical characteristic of the water absorbing agent that obtains.
Water absorbing resin particle preferably mixes with the water-insoluble inorganic particle after mixing with multivalent metal salt.Therefore, at least on the surface of water absorbing resin particle or near surface, the water-insoluble inorganic particle through the static reaction, have the coordinate bond of polyvalent metal and by the numerator mediated coordinate bond of water in air and hydrogen is strong is attached on the multivalent metal salt.The amount of the dust that is produced by waving of water-insoluble inorganic particle has obtained minimizing.
Embodiment
Hereinafter will more specifically be described the present invention through the mode of embodiment.Embodiment never limits the present invention.Hereinafter, be merely for the purpose of the convenience, " mass parts " sketched " part ", " liter " sketches " L ".In addition, " quality % " sketches " wt% ".
Measure the performance of water absorbing resin particle or water absorbing agent through following method.Except as otherwise noted, all measurements all are under the condition of room temperature (20-25 ℃) and 50RH% humidity, to carry out.
Be used under the situation such as the finished product of cleaning/hygienic material at water absorbing agent, water absorbing agent has absorbed moisture.Therefore before measuring, from finished product, suitably isolate water absorbing agent and in decompression, low temperature drying (for example, under 1mmHg or lower pressure) down 60 ℃ of dryings 12 hours.Be used for the embodiment of the invention and Comparative Examples used water absorbing agent contain 6 quality % or lower water.
Centrifugal water holding capacity (CRC)
Centrifugal water holding capacity or CRC are through 30 minutes absorbabilities to 0.90 quality % salt solution under the no-load.CRC is also referred to as " absorbability under the no-load ".
Water absorbing resin particle or the water absorbing agent of 0.200 gram placed non-weaving cloth equably, and (" Heatron paper " GSP-22, the bag of southern part of the country pulp industry Co., Ltd (Nangoku Pulp Kogyo Co. Ltd.) makes) is (among the 85mm * 60mm).Behind heated sealant, at room temperature be immersed in the salt solution (sodium-chloride water solution) of 0.90 quality % of excessive greatly (usually also 500mL).From salt solution, take out pocket after 30 minutes, (" centrifuge " H-122 was by centrifugation in the Ku Sen Co., Ltd (Kokusan Co. Ltd.) makes) 3 minutes at whizzer under the centrifugal force of in edanaABSORBENCY II441.1-99, describing (250G).Measure the quality W1 (g) of bag then.Do not use water absorbing resin particle or water absorbing agent to carry out same processing, measure the quality W0 (g) of bag.Calculate centrifugal water holding capacity (CRC) by W1, W0 with g/g according to following formula:
Centrifugal water holding capacity (CRC) (g/g)=(W1 (g)-W0 (g))/(quality of water absorbing resin particle or water absorbing agent (g))-1
4.83kPa the absorbability under the pressure (AAP)
4.83kPa absorbability under the pressure or AAP be 0.90 quality % salt solution under 4.83kPa pressure through 60 minutes absorbability.AAP is also referred to as the absorbability under the 4.83kPa.Fig. 1 is the cutaway view of AAP measurement mechanism 10.
In the measurement mechanism shown in Fig. 1 10, the absorbability under the gaging pressure (AAP).(aperture openings size 38 μ m) are fused to the bottom that internal diameter is the plastic support cylinder 1 of 60mm with 400 purpose stainless (steel) wires 2.Relative humidity at room temperature (from 20 ℃ to 25 ℃ (containing)) and 50RH% is sent 0.900g water absorbing resin particle or water absorbing agent forth on net 2 equably.Piston 4 and loading 5 are placed on water absorbing resin particle or the water absorbing agent with this in proper order, or test case 3.The external diameter of piston 4 and loading 5 is slightly less than 60mm so that very close to each other between piston and the support cylinder 1, and does not hinder the upper and lower of piston and support cylinder to move.Adjustment piston 4 and loading 5 are so that can apply the loading of 4.83kPa (0.7psi) equably.Measure the quality Wa (g) of entire measuring device 10 thus.
With measure the glass filter 7 that diameter is 90mm (by mutual physics and chemistry learn the limited manufactured of nitre making (Sogo Laboratory Glass Works Co., Ltd.); Aperture 100-120 μ m) being placed on the measurement diameter is petri diss 6 inboards of 150mm.The salt solution 9 (from 20 ℃-25 ℃ (containing)) of pouring 0.90 quality % into is until the level identical with the end face of glass filter 7.On filter 7, placing and measuring diameter is filter paper 8 (" JIS P 3801, No.2 ", the ADVANTEC Japan Co., Ltd of 90mm; Thickness 0.26mm, but trapped particles size 5 μ m) so that the surface of filter paper 8 can be all wetting.Remove excessive solution.
Said a whole set of measurement mechanism 10 is placed on the wetting filter paper with absorbent solution under load.After 1 hour, promote a whole set of measurement mechanism 10, measure its quality Wb (g).Calculate absorbability (AAP) 4.83kPa under by the Wa that records, Wb with g/g according to following formula.
4.83kPa under absorbability (AAP)=(Wb (g)-Wa (g))/(quality of water absorbing resin particle or water absorbing agent (0.900) g)
Salt solution water conservancy diversion rate (SFC)
Salt solution water conservancy diversion rate, or SFC are the values of expression its permeability for liquids when water absorbing resin particle or water absorbing agent have expanded.SFC is big more, and the permeability for liquids of water absorbing resin particle or water absorbing agent is high more.The embodiment that describes in the specification according to United States Patent (USP) 5849405 carries out the SFC test.Fig. 2 is the sketch map of SFC measurement mechanism 20.
In the measurement mechanism shown in Fig. 2 20, glass tube 22 is inserted in the groove 21.The salt solution 23 that the lower end of glass tube 22 is configured to 0.69 quality % can remain on the 5cm place, top, gel 34 bottoms in the pond (cell) 31.The salt solution 23 of 0.69 quality % in the groove 21 via have cock " L " pipe 24 be transported to pond 41 (?).Below pond 31, be provided with the collection container 38 that the solution in pond 31 has been passed through in collection.Collection container 38 places on the balance 39.The internal diameter in pond 31 is 6cm, and on the bottom, is provided with No. 400 stainless (steel) wires (mesh 38 μ m).Have hole 37 in the bottom of piston 36, can suitably pass through through hole 37 solution.In addition, piston 36 has the high-level infiltrative glass filter 35 that is connected with its bottom, so that water absorbing resin particle, water absorbing agent or its expansion gel can not get into hole 37.Pond 31 is placed on the platform (base).The table top that contacts with pond 31 is arranged to can not hinder the stainless (steel) wire 33 through solution.
The artificial urine (1) that here uses is the mixture of 0.25g two hydration calcium chloride, 2.0g potassium chloride, 0.50g Magnesium dichloride hexahydrate, 2.0g sodium sulphate, 0.85g ammonium dihydrogen phosphate (ADP), 0.15g diammonium hydrogen phosphate and 994.25g pure water.
Under the load of 2.07kPa (0.3psi), make the water absorbing resin particle or the water absorbing agent (0.900g) that are placed on equably in the container 30 in artificial urine (1), expand 60 minutes, use the measurement mechanism 20 shown in Fig. 2 with preparation gel 34.Write down the gel layer height of gel 34 subsequently.Then, under constant hydrostatic pressing, the salt solution 23 of 0.69 quality % passes through the expanded gel layer from groove 21 under the load of 2.07kPa (0.3psi).Carry out the SFC test in room temperature (from 20 ℃ to 25 ℃ (containing)).Use a computer with balance 39 with the interval in 20 seconds record as the amount of the liquid through gel layer of the function of time 10 minutes.With mass incremental (g) is that unit confirms the flow Fs (T) through the solution of expansion gel 34 (mainly between gel particle) divided by incremental time (s) and with g/s.With the time that obtains constant hydrostatic pressing and stable flow rate be Ts, the data computation flow rate that obtains in during only begin from time T s 10 minutes.The flow rate calculation Fs (T=0) that obtains in during begin from Ts 10 minutes, or the initial flow through gel layer.Through being extrapolated to T=0 to the result of the least square method of time, Fs (T) obtains Fs (T=0).
Salt solution water conservancy diversion rate (SFC)
＝(Fs(T＝0)×L0)/(ρ×A×ΔP)
＝(Fs(T＝0)×L0)/139506
Here, the flow rate of Fs (T=0) for representing by g/s; The serve as reasons height of gel layer of centimetre expression of L0; ρ is the density (=1.003g/cm of NaCl solution 3); A is the area (=28.27cm of gel layer topsheet surface in the pond 31 2); And Δ P be applied to hydrostatic pressing on the gel layer (=4,920dyne/cm 2).And the unit of SFC value is 10 -7Cm 3Sg -1
Fixed height absorption ability (FHA)
Measure fixed height absorption ability or FHA according to the method for describing among the U.S. Patent application 2005/000319A1 that announces.The height setting of measuring among the present invention is 20cm.
The logstandard deviation of quality average particle size particle size D50 and particle size distribution, σ ζ
Be used for the quality average particle size particle size according to what describe in the international application of announcing according to PCT WO2004/69915, or the logstandard deviation of D50 and particle size distribution, these two kinds of parameters of method of testing measurement of σ ζ.
Use the JIS standard screen screening water absorbing resin particle or the water absorbing agent of various aperture openings sizes (for example 850 μ m, 710 μ m, 600 μ m, 500 μ m, 425 μ m, 300 μ m, 212 μ m, 150 μ m and 45 μ m).On logarithmic probability paper, draw retained percentage R.According to this figure, read particle size, as quality average particle size particle size D50 corresponding to R=50 quality %.Draw the logstandard deviation of particle size distribution, σ ζ according to following formula.σ ζ value is more little, and particle size distribution is narrow more.
σζ＝0.5×1n(X2/X1)
Wherein X1 and X2 are respectively the particle sizes of R=84.1% and R=15.9%.
In order to measure the logstandard deviation σ ζ of quality average particle size particle size D50 and particle size distribution, carry out following classification.10.0g water absorbing resin particle or water absorbing agent place each JIS standard screen (Iida test sieve: diameter 8cm).The aperture openings of sieve is of a size of 850 μ m, 710 μ m, 600 μ m, 500 μ m, 425 μ m, 300 μ m, 212 μ m, 150 μ m and 45 μ m.Use vibro-classifier (Iida vibrating sieving machine, ES-65, sequence number 0501) to vibrate 5 minutes with the said water absorbing resin particle/water absorbing agent of classification in room temperature (from 20 ℃ to 25 ℃ (containing)) and 50RH% humidity.
Liquid distribution speed (LDV)
(spy opens flat 5-200068 to use japanese unexamined patent publication 5-200068/1993; Be equal to EP532002) in describe draw index measurement measurement device liquid distribution speed or LDV.Measure being used for by SUS304 stainless steel 2B level processing and preparing groove thin slice.
At first, 0 to 20cm mark the water absorbing resin particle of 1.00g ± 0.005g or the water absorbing agent groove ditch from the groove thin slice that is set to 20 ° of angles is sprayed equably.Use spatula to spread water absorbing resin particle or water absorbing agent more equably out then.
Liquid to be drawn is the salt solution (sodium-chloride water solution) of 0.9 quality %; With the ratio of every 1L salt solution 0.01g add " food analogue is with blue No. 1 " (can be from Tokyo chemical industry Co., Ltd (Tokyo Chemical Industry Co. Ltd.) obtains) to wherein with dyeing.
Adjust so that the 0.5cm place above the minimum point in groove of the liquid surface in the liquid container.After this, when stainless (steel) wire mesh (400 order) contact liq, begin to measure the liquid drawing time (WT).The time of showing with stopwatch that the liquid drawing time is spent when (WT) liquid is drawn into 10cm sign place.The speed that liquid in the liquid container and the stainless (steel) wire mesh edge direction vertical with liquid surface are down flooded the 0.5cm place, minimum point top to the groove is 1.35-1.40mm/s.According to computes liquid distribution speed LDV:
LDV(mm/s)＝100(mm)/WT(s)。
The proportion of particles of the size through 150-μ m aperture openings
Carry out and the logstandard deviation of measuring quality average particle size particle size D50 and particle size distribution, the hierarchical processing that σ ζ is identical.Calculate the ratio of representing with quality % of the particle of sieve that can be through having 150-μ m aperture openings according to the amount of the particle of the sieve through having 150-μ m aperture openings.
Water absorbs polymeric content (water-soluble component)
The salt solution of preparation 184.3g0.90 quality % in plastic containers with cover (250ml capacity).In this aqueous solution, add 1.00g water absorbing resin particle or water absorbing agent.Through the rotating spoon 16 hours of stirring the mixture to extract the polymer content that extracts in the resin.Liquid extract filters (" No. 3801,2, JIS P ", ADVANTEC Japan Co., Ltd (AdvantecToyo Kaisha, Ltd.), thickness 0.26mm, but trapped particles size 5 μ m) through filter paper.The filtrating of reserving the 50.0g acquisition is used for measuring as sample solution.
Add at first separately in the salt solution of the NaOH aqueous solution to 0.90 quality % of 0.1N, to pH10.With the titration that does not add water absorbing resin particle or water absorbing agent to pH10.Then, the HCl aqueous solution that adds 0.1N to pH2.7 to measure blank titration amount ([bNaOH] mL, [bHCl] mL).
Sample solution is carried out same titration operation to measure titer ([NaOH] mL, [HCl] mL).
For example; Under the situation of water absorbing resin particle of processing by the acrylic acid and the sodium salt thereof of known quantity or water absorbing agent, can calculate the polymer content that extracts in water absorbing resin particle or the water absorbing agent by the mean molecule quantity of monomer with by the titer that said process is measured according to following formula.If water absorbing resin particle or water absorbing agent are processed by the acrylic acid and the sodium salt thereof of unknown quantity, according to the mean molecule quantity that calculates monomer through the neutralization ratio of titration determination.
The polymer content that can extract (quality %)=0.1 * mean molecule quantity * 184.3 * 100 * ([HCl]-[bHCl])/1,000/1.0/50.0
Neutralization ratio (mol%)=(1-([NaOH]-[bNaOH])/([HCl]-[bHCl])) * 100
The amount of dust (characteristic that dust is relevant)
Under the condition that is discussed in more detail below,, measure the amount of the increment of the dust quality of passing through the glass fiber filter absorption and collecting as dust in the water absorbing agent through the time of scheduled period.With measurement pattern I operation, on the Heubach dust gauge of making by German Heubach Engineering Co., Ltd (Heubach EngineeringGmbH), measure.Atmospheric conditions during measuring are 25 ℃ of temperature (± 2 ℃), relative humidity 20-40% and normal pressure.Specific procedure is following:
(1) in going barrel 200, places 100.00g sample (water-absorbing resin).
(2) measuring diameter with 0.00001 gram precision (" Da " gram) is the quality (but trapped particles size 5 μ m (JIS P3801)) of the glass fiber filter of 50mm.For example, through the glass fibre GC-90 of braiding Advantec, or the glass fibre that any diameter equals 50mm prepares filter.
(3) large-scale particle separator 201 is connected with going barrel 200.Also connect the filter big envelope 202 that glass fiber filter 204 is housed.
(4) on the control section 203 of dust gauge, set following condition.Measure.
Drum slewing rate=30R/min
Absorption of air volume=20L/min
Time (during the measurement)=30 minute
(5) after the scheduled period, measure the quality of glass fiber filter 204 with 0.00001 gram precision (" Db ").
Through the computes Dust Capacity:
Dust Capacity (ppm)=(Db-Da)/100.00 * 1,000,000
The coating vibration-testing
In coating vibration-testing (PS); The glass container 6 of diameter 6cm, high 11cm is equipped with bead and 30g water absorbing resin particle or the water absorbing agent of 10g diameter 6mm; Glass container 6 is loaded in the coating vibrator (No. 488; The smart mechanism of Japan is done in the limited company (Toyo Seiki SeisakushoCo., Ltd.)), to vibrate 800 weeks of per minute (CPM).The detailed content of this kind device is referring to japanese unexamined patent publication 9-235378/1997 (spy opens flat 9-235378).
The test that time of vibration is set at 30 minutes and 10 minutes is designated as coating vibration-testing 1 and coating vibration-testing 2 respectively.
After vibration, use the JIS standard screen (aperture openings 2mm) to remove bead, stay the water absorbing resin particle or the water absorbing agent that have damaged.
Triboelectric charge
In the glass screwed pipe, place water absorbing agent and the sealing of 25g.Said screwed pipe is No. 7 screwed pipes, can obtain from Maruemu company, and the internal diameter that records is that 23mm, external diameter are 35mm and highly are 78mm.Its lid is polypropylene, and uses heat-resisting Highsheet packing.
Continuous shaking screwed pipe 20 seconds, water absorbing agent is sealed in the said screwed pipe.Can use machine or manually vibrate.Per second vibrating tube 3 to 5 times, the displacement of each vibration are 10 to 20cm.Vibration need be carried out to such an extent that the water absorbing agent in the screwed pipe is moved as far as possible greatly and soon.
After vibration 20 seconds, the wide and unfertile land on thin slice of the water absorbing agent in making at once in the screwed pipe is spread out.The operation manual of being prepared by manufacturer (Instruction Manual) according to subsidiary electricity meter uses contactless static electricity meter (" FMX-002 ", Japanese Simco joint-stock company (Simco Japan Inc.)) to measure the charge potential of water absorbing agent.Charge potential measure to such an extent that accomplish in after water absorbing agent wide and unfertile land on thin slice is spread out 15 seconds.Like what indicate in the operation manual, the distance during measuring between static electricity meter and the water absorbing agent is 25mm ± 1mm.Through reading the charge potential that shows on the static electricity meter after 15 seconds the Measuring Time at once.If the charge potential that reads is shown as negative electrical charge, think that then triboelectric charge is a negative electrical charge.
More specifically, if the charge potential that the static electricity meter shows thinks that then triboelectric charge is a positive charge in+0.01 to+20.00kv scope.If the charge potential that the static electricity meter shows in-20.00 to-0.01kv scope, is then thought the triboelectric charge negative electrical charge.The charge potential that in triboelectric charge is measured, records is preferably from-10.00kv to-0.01kv (containing), more preferably from-5.00kv to-0.01kv (containing) to keep low travelling speed stability index.
The thin slice that uses in the measurement is that " the thick type of Vinytop (Vinytop Thick Model), " is derived from Showa gloves company (Showa GloveCo.) from the piece of a kind of 12cm x12cm of gloves cutting-out.The outside of gloves is Corvic (a non-phthalate ester plasticiser), and the inboard is the artificial silk hair.
When water absorbing agent wide and unfertile land on thin slice was spread out, the outside of gloves was used as the top side of thin slice.Spread water absorbing agent out in the top side of thin slice so that water absorbing agent can be in heaps and not be flowed out thin slice.In this state measurement triboelectric charge." heap " of water absorbing agent refers to, and for example water absorbing agent is spread out at thin slice, form highly be 2 to 4cm and base diameter be 7 to 12cm taper or similar shape.Being 23 ± 2 ℃ in temperature is to carry out the measurement of triboelectric charge in 40 ± 3% the space with relative humidity.
SiO in the dust 2Ratio
SiO in the dust of representing with quality % that in the dust of the measuring amount of collecting, records 2Ratio as SiO in the dust 2Ratio.
Through elements of Na, aluminium and silicon in the analysis dust and by calculating water-absorbing resin and SiO according to the neutralization ratio of water-absorbing resin and the result of weight average molecular weight analysis 2Mass ratio to the SiO in the dust 2Quantitatively (is the situation of sodium salt in neutralized reaction product or salt).
If the salt of the neutralization of water-absorbing resin is the unit price basic salt/ammonium salt of potassium, lithium etc., can confirm SiO in the dust through similar method 2Ratio.For example, under the situation of sylvite, can measure SiO in the dust through the mass percent of analytical element potassium, aluminium and silicon 2Ratio.
Use SEM/EDS (energy dispersion X-ray spectrometer method (energy dispersive x-rayspectrometer)) elements of Na, aluminium, silicon etc. to be carried out quantitative analysis through ZAF.
Through the dust of collecting appropriate amount from the glass fiber filter of use the dust of quantitative measurment and the dust sample that its carbon ribbon part preparation that is transferred to the 5mm x5mm that is attached to SEM sample bottom (sample bases) is used to analyze.When so operating, spray dust on carbon ribbon so that dust can distribute equably.
Analysis condition is listed for as follows.
Device: SEM (available from the flying-spot microscope JSM-5410LV of JOEL).
Accelerating potential: 20kv
Enlargement ratio: 20X
Measured zone: about 900 μ m x1,200 μ m
The 50 volume % or more measurement of the whole measured zone that dust is covered more.
Si peak: SiK1.739KeV
Na peak: NaK1.041KeV
Al peak: AlK1.486KeV
If note the overlap of peaks of these peaks and other element (for example, NaK and ZnLa), the peak value that then deducts other overlapping element (situation at Zn is ZnKa) is to proofread and correct.
The neutralization ratio N of the water-absorbing resin of representing according to the mass percent (hereinafter possibly sketched and be " Si% ") of the mass percent (hereinafter possibly sketched and be " Al% ") of the mass percent (hereinafter possibly sketched and be " Na% ") of elements of Na, element aluminum, elemental silicon, with mol%; And the molecular weight Mw of counterpoise unit's polymer (polymer-unit-weight-average), SiO in the dust of representing with quality % through computes 2Ratio:
Molecular weight Mw=72.06x (the 1-N/100)+94.05xN/100 of counterpoise unit's polymer (polymer-unit-weight-average)
Polymer content P=(Na%/23)/(N/100) xMw
SiO 2Content S=(Si%/28.08) x60.08
Aluminum sulfate content A=(Al%/26.98) x630.4/2
SiO in the dust of representing with quality % 2Ratio=S/ (P+S+A) x100
In equation, " N " is the neutralization ratio of water-absorbing resin, can be through being used to measure the identical method of polymer content that water can extract and measuring with above-mentioned.
SiO in the dust 2Ratio be preferably through said method and measure.When having not perhaps many other composition of principal component, elementary analysis or other conventional known method can be used for measuring.
The waving property of dust
The 100g water absorbing agent is placed stainless steel funnel (ISO/TR15, the steel pattern number X5CrNiMo17-12-3 of appointment in 510; Internal diameter 10mm; Height 145mm; 20 ° at oblique angle).It is the cylindrical beaker of 8cm for the 12cm diameter highly that the funnel that comprises water absorbing agent is fallen into from the height of 30cm.When funnel bump beaker, from visually observing the difficulty or ease that produce dust.In measurement, near cylindrical beaker, be placed with a blackboard to be easier to observe the dust of generation.
The waving property of dust is divided into following 5 kinds of levels.
Waving property 1: be difficult to produce.
Waving property 2: produce a little.
Waving property 3: produce.
Waving property 4: produce a lot of.
Waving property 5: produce many.
The quantitative approach of silica in the water absorbing agent
Can measure the amount of silica in the water absorbing agent through elementary analysis or similar known method.Can use any measuring method.Be described below and be merely example.
(1) the 0.500g water absorbing agent is placed polypropylene beaker (capacity 250mL).Add the sodium carbonate (anhydrous) of 0.5g SILVER REAGENT.
(2) use the 100-mL plastic cylinder 80 ℃ of deionized waters that in the polypropylene beaker, add 100mL (grade 3, ISO3696).Temperature keeps 80 ℃, and the content in the stirred flask 2 hours is with dissolved solid silica.
(3) through pleating quantitative filter paper filtering content thing (5C number, 185mm, ToyoRoshi Kaisha Co., Ltd) in the plastic funnel.Filtrating is contained in the plastic cylinder of 100-mL.
(4) when on the filter paper in the plastic funnel during remaining a little liquid (behind the ≌ 1 hour), use plastics Komagome pipette add 3mL 6N hydrochloric acid so that gel shrink as much as possible.
(5) the 6N hydrochloric acid that adds 3mL is to the filtrating that obtains.Subsequently, add the ammonium molybdate solution of the 5 quality % of 4mL twice.The deionized water that adds appropriate amount is to increase the volume of content.The sealing graduated cylinder also shakes well.
(6) use spectrophotometer (IU-1100, Co., Ltd of Hitachi (Hitachi) in 5 to 20 seconds after generation is painted; Wavelength 410nm, cell thickness 10mm) measures the absorbance (ABS) of the coloring solution that obtains in (5).Use deionized water on blank sample, carry out same processing (grade 3, ISO3696).
(7) deduct the absorbance of blank sample from the absorbance of the coloring solution that obtains.The acquisition value is identified as the absorbance of specimen.Confirm the fine grain amount of silica in the specimen (hereinafter description) according to calibration curve.
Draw calibration curve
Silica fine grained through adding 0 mass parts, 0.03 mass parts, 0.06 mass parts, 0.1 mass parts, 0.2 mass parts, 0.3 mass parts, 0.5 mass parts, 1.0 mass parts respectively (for example; Aerosil (registration mark) available from Japanese Aerosil Co., Ltd) to the not silica containing water-absorbing resin (for example, hereinafter is with the water-absorbing resin (1-30) that details) of 100 mass parts.
Measure the absorbance that the silicon dioxide microparticle content wherein represent with quality % is known these standard samples through said process.Draw calibration curve according to the absorbance that records.
Embodiment 1
With 436.4g acrylic acid, 4, the PAA aqueous solution of 617.9g37 quality %, 381.0g pure water and 11.40g polyethyleneglycol diacrylate (molecular weight 523) are dissolved in the reactor (10 liters of internal capacities) that adds upper cover on the stainless die both arms of the jacketed type kneader with two ∑ type blades and form with preparation feedback liquid.Then, under nitrogen atmosphere to this reactant liquor deaeration 20 minutes.Subsequently, when stirring, in reactant liquor, add the sodium persulfate aqueous solution of 38.76g10 quality % and the L-aqueous ascorbic acid of 24.22g0.1 quality %, after its 25 second, begin polymerization.When the gel that crushing generates, make and be aggregated in 20-95 ℃ and carry out.Take out moisture gel cross-linked polymer after 0 minute at polyase 13.The moisture gel cross-linked polymer of gained is by the about 5mm of comminution to size or littler.
The moisture gel cross-linked polymer of this comminution is spread out on 50 purpose wire nettings, and in 180 ℃ of hot blasts dry 50 minutes.Use the broken dry thing of roller abrasive dust, and use the JIS standard screen of aperture openings size 710 μ m and 175 μ m to carry out classification.Thus, water absorbing resin particle (1) has the shape of pulverizing brokenly.The quality average particle size particle size D50 of resin particle (1) is 341 μ m.The logstandard deviation of the particle size distribution of particle (1), σ ζ are 0.33.The centrifugal water holding capacity (CRC) of water absorbing resin particle (1) is the polymer content that 35.4g/g and the water that contains 7.3 quality % can extract.
The water absorbing resin particle (1) of 100 mass parts that obtain evenly mixes with surface crosslinking agent, and said crosslinking agent is 1 of 0.384 mass parts, the sodium peroxydisulfate mixed solution of the propane diols of 4-butanediol, 0.632 mass parts, the pure water of 3.39 mass parts and 0.1 mass parts.Add hot mixt at 212 ℃ then.Different mixtures uses different preparations heat time heating time: 30 minutes, 35 minutes, 40 minutes and 45 minutes.Then, the particle of division generation can be of a size of the JIS standard screen of 710 μ m through aperture openings until it.Subsequently; Make the particle of division carry out coating vibration-testing 1 to prepare surface-crosslinked water absorbing resin particle sample: a kind of sample heats 30 minutes with preparation water absorbing resin particle (1-30); Another kind of sample heats 35 minutes with preparation water absorbing resin particle (1-35); Another kind of sample heated 45 minutes with preparation water absorbing resin particle (1-45) with preparation water absorbing resin particle (1-40) in 40 minutes in another kind of sample heating.
Add a kind of surface-crosslinked water absorbing resin particle sample of acquisition of solution to 100 mass parts then respectively.Said solution is the mixture of propane diols of sodium lactate aqueous solution and 0.002 mass parts of 60 quality % of aluminum sulfate aqueous solution (the aluminium oxide aqueous solution that is equivalent to 8 quality %), 0.134 mass parts of 27.5 quality % of 0.4 mass parts.After adding solution, said sample is 60 0Drying is 1 hour in the no wind environment of C.After drying, the division sample can be of a size of the JIS standard screen of 710 μ m through aperture openings until it.Subsequently; Make the particle of division carry out coating vibration-testing 2: from water absorbing resin particle (1-30) preparation water absorbing resin particle (1-30A) to prepare the water absorbing resin particle sample; From water absorbing resin particle (1-35) preparation water absorbing resin particle (1-35A), from water absorbing resin particle (1-40) preparation water absorbing resin particle (1-40A) and from water absorbing resin particle (1-45) preparation water absorbing resin particle (1-45A).
Add water absorbing resin particle (1-30A) available from HDK (registration mark) H2050EP to 100 mass parts of 0.040 mass parts of Wa Ke company, (1-35A), (1-40A) and (1-45A) and (1-4) respectively with preparation water absorbing agent (1-1), (1-2), (1-3).
Similarly, add water absorbing resin particle (1-30A) available from HDK (registration mark) H2050EP to 100 mass parts of 0.070 mass parts of Wa Ke company, (1-35A), (1-40A) and (1-45A) and (1-8) respectively with preparation water absorbing agent (1-5), (1-6), (1-7).
Comparative Examples 1
Following test is carried out with reference to comparative example 1, embodiment 1 and the embodiment 2 of japanese unexamined patent publication (spy opens) 2000-93792.
1.70 the trimethylolpropane triacrylate of mass parts is dissolved in the PAA aqueous solution that the neutralization ratio of 5,500 mass parts is 75mol% (monomer concentration 38%) with preparation feedback liquid.Then, reactant liquor deaeration 30 minutes under nitrogen atmosphere.Carry the reactor (internal volume 10L) that adds upper cover on reactant liquor to the stainless die both arms of the jacketed type kneader and form then with two ∑ type blades.When keeping reactant liquor, make nitrogen replacement system at 30 ℃.Subsequently, when stirring, in reactant liquor, add the sodium peroxydisulfate of 2.46 mass parts and the L-ascorbic acid of 0.10 quality, after it is 1 minute, begin polymerization.Make and be aggregated in 30 ℃ to 80 ℃ (containing) and carry out.Take out moisture gel cross-linked polymer after 60 minutes in polymerization.The moisture gel cross-linked polymer of gained is by the about 5mm of comminution to size.
The moisture gelatinous polymer of this comminution is spread out on 50 purpose wire nettings, and in 150 ℃ of hot blasts dry 90 minutes.Use vibromill to pulverize dry thing, and use 20 purpose wire nettings to carry out classification.Thus, the water-absorbing resin precursor of pulverizing brokenly (A) has the average particle size particle size of 330 μ m.
The water-absorbing resin precursor (A) of 100 mass parts that obtain mixes with surface crosslinking agent equably, and said crosslinking agent is the mixed solution of isopropyl alcohol of water and 1 mass parts of ethylene glycol diglycidylether, 3 mass parts of propane diols, 0.05 mass parts of 1 mass parts.Then 210 ℃ of thermally treated mixtures 40 minutes to obtain contrast water absorbing resin particle (1-1).Measure the water absorbing capacity and the water absorbing capacity under pressure of contrast water absorbing resin particle (1-1) through the method for describing among japanese unexamined patent publication (spy opens) 2000-93792; CRC is 31g/g, and AAP is 33g/g.
Mixes with acquisition with the contrast water absorbing resin particle (1-1) of 100 mass parts as the hydrophobic silica of 0.05 mass parts of organic powder (RA200HS that makes by Japanese Aerosil Co., Ltd) and to contrast water absorbing agent (1-1).Said hydrophobic silica is the cationic dispersing liquid of pH7.5 or higher 4%, and the specific area that records through BET (P91) is 145 ± 15m 2/ g.
The water-absorbing resin precursor (A) of 100 mass parts that obtain mixes with surface crosslinking agent equably, and said surface crosslinking agent is the mixed solution of isopropyl alcohol of water and 1.5 mass parts of ethylene glycol diglycidylether, 4.5 mass parts of 0.1 mass parts.200 ℃ of thermally treated mixtures 35 minutes to obtain contrast water absorbing resin particle (1-2).Measure the water absorbing capacity and the water absorbing capacity under pressure of contrast water absorbing resin particle (1-2) through the method for describing among japanese unexamined patent publication (spy opens) 2000-93792; CRC is 32g/g, and AAP is 31g/g.
Add the contrast water absorbing resin particle (1-2) of water to 100 mass parts of 1 mass parts.Subsequently, the organic powder of 0.1 mass parts (RA200HS that is made by Japanese Aerosil Co., Ltd) mixes with acquisition with the similar product of said circumstances and contrasts water absorbing agent (1-2).
Table 1 show water absorbing resin particle (1), (1-30), (1-35), (1-40), (1-45), (1-30A), (1-35A), (1-40A) and (1-45A), water absorbing agent (1-1), (1-2), (1-3), (1-4), (1-5), (1-6), (1-7) and (1-8), contrast water absorbing resin particle (1-1) with (1-2) and the measurement result that contrasts water absorbing agent (1-1) and physical characteristic (1-2).
Embodiment 2
With 436.4g acrylic acid, 4, the PAA aqueous solution of 617.9g37 quality %, 381.0g pure water and 11.40g polyethyleneglycol diacrylate (molecular weight 523) are dissolved in the reactor (10 liters of internal capacities) that adds upper cover on the stainless die both arms of the jacketed type kneader with two ∑ type blades and form with preparation feedback liquid.Then, under nitrogen atmosphere to this reactant liquor deaeration 20 minutes.Subsequently, when stirring, in reactant liquor, add the sodium persulfate aqueous solution of 29.07g10 quality % and the L-aqueous ascorbic acid of 24.22g0.1 quality %, after it is 1 minute, begin polymerization.When the gel that crushing generates, make and be aggregated in 20-95 ℃ and carry out.Take out moisture gel cross-linked polymer after 0 minute at polyase 13.The moisture gel cross-linked polymer of gained is by the about 5mm of comminution to size or littler.
The moisture gel cross-linked polymer of this comminution is spread out on 50 purpose wire nettings, and in 180 ℃ of hot blasts dry 50 minutes.Use the broken dry thing of roller abrasive dust, and use the JIS standard screen of aperture openings size 710 μ m and 175 μ m to carry out classification.Thus, water absorbing resin particle (2) has the shape of pulverizing brokenly.The quality average particle size particle size D50 of particle (2) is 341 μ m.The logstandard deviation of the particle size distribution of particle (2), σ ζ are 0.33.The centrifugal water holding capacity (CRC) of water absorbing resin particle (2) is the polymer content that 33.5g/g and the water that contains 9.0 quality % can extract.
The water absorbing resin particle (2) of 100 mass parts that obtain evenly mixes with surface crosslinking agent, and said crosslinking agent is 1 of 0.384 mass parts, the sodium peroxydisulfate mixed solution of the propane diols of 4-butanediol, 0.632 mass parts, the pure water of 3.39 mass parts and 0.1 mass parts.Then 212 ℃ of thermally treated mixtures 50 minutes.The particle that division produces can be of a size of the JIS standard screen of 710 μ m through aperture openings until it.Subsequently, make the particle of division carry out coating vibration-testing 1 to obtain surface-crosslinked water absorbing resin particle (2-50).
Add water absorbing resin particle (2-50) sample of the HDK available from Wa Ke company (registration mark) H2050EP to 100 mass parts of different amounts: the HDK that adds 0.010 mass parts to one of sample with preparation water absorbing agent (2-1); Add 0.020 mass parts with preparation water absorbing agent (2-2); Add 0.040 mass parts with preparation water absorbing agent (2-3), add 0.070 mass parts to prepare water absorbing agent (2-4) and to add 0.100 mass parts with preparation water absorbing agent (2-5).
Comparative Examples 2
The water absorbing resin particle (2-50) that adds 100 mass parts that obtain among the HDK available from Wa Ke company (registration mark) H2050EP to embodiment 2 of 0.300 mass parts is with preparation contrast water absorbing agent (2-1).Add 0.3000 mass parts available from Aerosil (registration mark) 200 the water absorbing resin particles (2-50) of Japanese Aerosil Co., Ltd to another 100 mass parts with preparation contrast water absorbing agent (2-2).
Table 2 show water absorbing resin particle (2) and (2-50), water absorbing agent (2-1), (2-2), (2-3), (2-4) and (2-5) and the measurement result of contrast water absorbing agent (2-1) and physical characteristic (2-2).
Embodiment 3
At the polypropylene containers that is coated with styrenic foams (heat-insulating material) (internal diameter 80mm; 1 liter of internal capacity) mixed solution (A1) and solution (B1) in.When using magnetic stirrer to stir, in open system, promptly mix through adding solution (B1) to solution (A1).Solution (A1) is the mixture of diethylene triamine pentacetic acid (DTPA) five sodium water solutions of 1.0 quality % of polyethyleneglycol diacrylate (molecular weight 523) and the 1.35g of 220.81g acrylic acid, 1.154g.Solution (B1) is the mixture of ion exchange water of sodium hydrate aqueous solution and 179.94g of the 48.5 quality % of 184.49g, and its temperature is adjusted to 50 ℃.The result who mixes is a kind of monomer solution, because the heat of neutralization has been increased to 100 ℃ with the analgesic temperature wherein of branch.
The sodium persulfate aqueous solution of the 3 quality % of interpolation 12.26g is to the monomer solution that obtains.After stirring several seconds, solution is poured in the rustless steel container of the pellet type in the open system.In when falling solution, container is heated so that surface temperature reaches 100 ℃ on a heat dish (Neo heat dish H1-1000 is by As One manufactured).Container has a bottom (250x250mm), and the inboard of container is coated with Teflon (registration mark).Its top is 640x640mm, highly is 50mm.The cross section of intermediate portion is trapezoidal.Its top is an opening.
Be poured in the pallet soon at monomer solution, polymerization begins.Produce steam during polymerization is carried out, solution is in all directions foaming/expansion.Subsequently, content is contracted to the size of being a bit larger tham the tray bottom.Expand and contraction completion in 1 minute.In container, keep after 4 minutes, remove aqueous polymers.
Use square to be of a size of the meat grinder (aqueous polymers that the aqueous polymers that is obtained by Iidzuka Industrial Co., Ltd (IidzukaIndustries Co., the meat grinder VR400K of imperial family (Royal) that Ltd.) makes) crushing grinds with acquisition of 9.5mm.
This moisture gel cross-linked polymer that grinds is spread out on 50 purpose wire nettings, and in 180 ℃ of hot blasts dry 50 minutes.Use the broken dry thing of roller abrasive dust, and use the JIS standard screen of aperture openings size 710 μ m and 175 μ m to carry out classification.Thus, water absorbing resin particle (3) has the shape of pulverizing brokenly.The quality average particle size particle size D50 of particle (3) is 329 μ m.The logstandard deviation of the particle size distribution of particle (3), σ ζ are 0.31.The centrifugal water holding capacity (CRC) of water absorbing resin particle (3) is the polymer content that 33.0g/g and the water that contains 9.0 quality % can extract.
The water absorbing resin particle (3) of 100 mass parts that obtain mixes with surface crosslinking agent, and said crosslinking agent is 1 of 0.36 mass parts, the propane diols of 4-butanediol, 0.6 mass parts and the pure water mixed solution of 3.2 mass parts.Use Loedige mixer mixing mixed liquor and 200 ℃ of thermally treated mixtures 50 minutes.Divide said particle and can be of a size of the JIS standard screen of 710 μ m through aperture openings until it.Subsequently, make the particle of division carry out coating vibration-testing 1 to obtain surface-crosslinked water absorbing resin particle (3-50).
Add a kind of surface-crosslinked water absorbing resin particle (3-50) of acquisition of solution to 100 mass parts.Said solution is the mixture of propane diols of sodium lactate aqueous solution and 0.002 mass parts of 60 quality % of aluminum sulfate aqueous solution (the aluminium oxide aqueous solution that is equivalent to 8 quality %), 0.134 mass parts of 27.5 quality % of 0.40 mass parts.After adding solution, said particle in 60 ℃ no wind environment dry 1 hour.After drying, the division particle can be of a size of the JIS standard screen of 710 μ m through aperture openings until it.Subsequently, make the particle of division carry out coating vibration-testing 2 to obtain water absorbing resin particle (3-50A).
Add the sample of water absorbing resin particle (3-50A) of the HDK available from Wa Ke company (registration mark) H2050EP to 100 mass parts of different amounts: the HDK that adds 0.020 mass parts to one of sample with preparation water absorbing agent (3-1); Add 0.040 mass parts with preparation water absorbing agent (3-2); Add 0.060 mass parts with preparation water absorbing agent (3-3); Add 0.080 mass parts with preparation water absorbing agent (3-4); Add 0.0990 mass parts with preparation water absorbing agent (3-5), add 0.1250 mass parts to prepare water absorbing agent (3-6) and to add 0.1500 mass parts with preparation water absorbing agent (3-7).
Embodiment 4
Add 0.100 mass parts available from the sample of the water absorbing resin particle (3-50A) of 100 mass parts of preparation among the Aerosil (registration mark) 200 to embodiment 3 of Japanese Aerosil Co., Ltd to obtain water absorbing agent (4-1).The Aerosil that adds 0.1250 mass parts to the particle (3-50A) of another 100 mass parts to obtain contrast water absorbing agent (4-2).
Table 3 show water absorbing resin particle (3), (3-50) and (3-50A), water absorbing agent (3-1), (3-2), (3-3), (3-4), (3-5), (3-6) and (3-7) and the measurement result of water absorbing agent (4-1) and physical characteristic (4-2).
Embodiment 5
At the polypropylene containers that is coated with styrenic foams (heat-insulating material) (internal diameter 80mm; 1 liter of internal capacity) mixed solution (A) and solution (B) in.When using magnetic stirrer to stir, in open system, promptly mix through adding solution (B) to solution (A).Solution (A) is the mixture of diethylene triamine pentacetic acid (DTPA) five sodium water solutions of 1.0 quality % of polyethyleneglycol diacrylate (molecular weight 523) and the 1.35g of 221.92g acrylic acid, 1.53g.Solution (B) is the mixture of ion exchange water of sodium hydrate aqueous solution and 182.55g of the 48.5 quality % of 180.33g, and its temperature is adjusted to 50 ℃.The result who mixes is a kind of monomer solution, because the heat of neutralization has been increased to about 100 ℃ with the analgesic temperature wherein of branch.
The sodium persulfate aqueous solution of the 3 quality % of interpolation 12.32g is to the monomer solution that obtains.After stirring several seconds, solution is poured in the rustless steel container of the pellet type in the open system.In when falling solution, container is heated so that surface temperature reaches 100 ℃ on a heat dish (Neo heat dish H1-1000 is by As One manufactured).Container has a bottom (250x250mm), and the inboard of container is coated with Teflon (registration mark).Its top is 640x640mm, highly is 50mm.The cross section of intermediate portion is trapezoidal.Its top is an opening.
Be poured in the pallet soon at monomer solution, polymerization begins.Produce steam during polymerization is carried out, solution is in all directions foaming/expansion.Subsequently, content is contracted to the size of being a bit larger tham the tray bottom.Expand and contraction completion in 1 minute.In container, keep after 4 minutes, remove aqueous polymers.
The aqueous polymers of aqueous polymers that meat grinder (by the imperial meat grinder VR400K of the Iidzuka Industrial Co., Ltd manufacturing) crushing of using square to be of a size of 9.5mm obtains to obtain to grind.
This moisture gel cross-linked polymer that grinds is spread out on 50 purpose wire nettings, and in 180 ℃ of hot blasts dry 50 minutes.In the roller mill, pulverize dry thing then, and use the JIS standard screen of aperture openings size 710 μ m and 175 μ m to carry out classification.Thus, water absorbing resin particle (5) has the shape of pulverizing brokenly.The quality average particle size particle size D50 of particle (5) is 342 μ m.The logstandard deviation of the particle size distribution of particle (5), σ ζ are 0.34.The centrifugal water holding capacity (CRC) of water absorbing resin particle (5) is the polymer content that 31.0g/g and the water that contains 8.0 quality % can extract.
The water absorbing resin particle (5) of 100 mass parts that obtain mixes with surface crosslinking agent equably, and said crosslinking agent is 1 of 0.31 mass parts, the propane diols of 4-butanediol, 0.49 mass parts and the pure water mixed solution of 2.4 mass parts.Then 195 ℃ of thermally treated mixtures 50 minutes.Divide said particle and can be of a size of the JIS standard screen of 710 μ m through aperture openings until it.Subsequently, make the particle of division carry out coating vibration-testing 1, to obtain surface-crosslinked water absorbing resin particle (5-50).
Add a kind of surface-crosslinked water absorbing resin particle (5-50) of acquisition of solution to 100 mass parts.Said solution is the mixture of propane diols of sodium lactate aqueous solution and 0.0025 mass parts of 60 quality % of aluminum sulfate aqueous solution (the aluminium oxide aqueous solution that is equivalent to 8 quality %), 0.16 mass parts of 27.5 quality % of 0.50 mass parts.After adding solution, particle in 60 ℃ no wind environment dry 1 hour.After drying, the division sample can be of a size of the JIS standard screen of 710 μ m through aperture openings until it.Subsequently, make the particle of division carry out coating vibration-testing 2 to obtain water-absorbing resin (5-50A).
Add the sample of water absorbing resin particle (5-50A) of the HDK available from Wa Ke company (registration mark) H2050EP to 100 mass parts of different amounts: the HDK that adds 0.040 mass parts to one of sample with preparation water absorbing agent (5-1), add 0.080 mass parts with preparation water absorbing agent (5-2) and add 0.1250 mass parts with preparation water absorbing agent (5-3).
Table 4 shows the measurement result of water absorbing resin particle (5), (5-50), (5-50A) and water absorbing agent (5-1), (5-2) and physical characteristic (5-3).
Figure G2007800109479D00591
*1 unit: 10 -7Cm 3Sg -1
*2 are of a size of the proportion of particles of size of the sieve of 150 μ m through aperture openings
WARPs: water absorbing resin particle
WAA: water absorbing agent
C-WARPs: contrast water absorbing resin particle
C-WAA: contrast water absorbing agent
As shown in table 1; When comparing with water absorbing resin particle (1); Through adding the sample of surface crosslinking agent to water absorbing resin particle (1); Surface glue joins mixture, and product is carried out coating vibration-testing 1 demonstrates relatively low CRC with the water absorbing resin particle (1-30) to (1-45) that produces mechanical damage and obtain, but demonstrates the AAP and the SFC of improvement.
The contrast of water absorbing resin particle (1-30) to (1-45) clearly illustrates that the physical characteristic that can regulate the water absorbing resin particle of acquisition heat time heating time through changing.
Demonstrate low slightly AAP through using aluminum sulfate aqueous solution to handle water absorbing resin particle (1-30) to (1-45) and product is carried out coating vibration-testing 2 with the water absorbing resin particle (1-30A) to (1-45A) that produces the mechanical damage acquisition, but the SFC that improves greatly.
Water absorbing agent (1-1) to (1-4) through adding hydrophobic silica to water absorbing agent particle (1-30A) to (1-45A) acquisition in fact maintains good CRC and AAP, also demonstrates very high SFC.In other words, obtained to have high CRC, the useful water absorbing agent of AAP and SFC value.
Though contrast water absorbing resin particle (1-1) with (1-2) be to use hydrophobic silica to prepare; But because said particle is through using the classification of JIS standard screen, it contains the particle of size that can be of a size of the sieve of 150 μ m through aperture openings greater than 5 quality %.For contrasting water absorbing agent (1-1) and situation (1-2) too.Because these contrast water absorbing resin particles contain a high proportion of particle of size that can be of a size of the sieve of 150 μ m through aperture openings with the contrast water absorbing agent, it has low permeability for liquids.Therefore, its SFC is very low.Its AAP and FHA are also very low.Can produce a large amount of dust.
Figure G2007800109479D00611
All water absorbing resin particles in the table 2 and water absorbing agent have the dust of comparison than water absorbing agent (2-1) and amount much less (2-2).Though the inorganic particle that has added same amount contrasts water absorbing agent (2-1) and produces less dust and demonstrate better SFC and AAP to contrasting water absorbing agent (2-1) and (2-2).
Water absorbing agent (2-1) to (2-4) has extra high FHA.
All water absorbing resin particles in the table 3 and water absorbing agent (particularly, water absorbing agent (3-1) is to (3-7)) the considerably less dust of the amount of having.Particularly, though added inorganic particle to the water absorbing agent (3-6) and the contrast water absorbing agent (4-2) of same amount, water absorbing agent (3-6) produces less dust.
Water absorbing agent (3-1) to (3-5) demonstrates good especially FHA.
Figure G2007800109479D00651
As shown in table 4ly go out, water absorbing agent (5-1) to (5-3) demonstrates excellent liquid permeability (SFC) and produces considerably less dust.
Embodiment 6
Except the HDK available from Wa Ke company (registration mark) H20 that adds 0.050 mass parts replace the water absorbing resin particle (1-30A), (1-35A), (1-40A) of the HDK available from Wa Ke company (registration mark) H2050EP to 100 mass parts of adding 0.040 mass parts and (1-45A), carry out with embodiment 1 in identical process to obtain water absorbing agent (6-1), (6-2), (6-3) and (6-4) respectively.
Table 5 shows the kind and the quantity of the silica of interpolation, and the measurement result of water absorbing agent (6-1), (6-2), (6-3) and CRC (6-4), AAP, SFC, FHA, D50 and be of a size of the proportion of particles of the sieve of 150 μ m through aperture openings.
Figure G2007800109479D00671
As shown in table 5ly go out, water absorbing agent (6-1) to (6-4) demonstrates excellent liquid permeability (SFC) and high AAP and FHA and produces considerably less dust.
Embodiment 7
With 436.4g acrylic acid, 4, the PAA aqueous solution of 617.9g37 quality %, 381.0g pure water and 7.6g polyethyleneglycol diacrylate (molecular weight 523) are dissolved in the reactor (10 liters of internal capacities) that adds upper cover on the stainless die both arms of the jacketed type kneader with two ∑ type blades and form with preparation feedback liquid.Then, under nitrogen atmosphere to this reactant liquor deaeration 20 minutes.Subsequently, when stirring, in reactant liquor, add the sodium persulfate aqueous solution of 29.07g10 quality % and the L-aqueous ascorbic acid of 24.22g0.1 quality %, after it is 1 minute, begin polymerization.When the gel that crushing generates, make and be aggregated in 25-95 ℃ and carry out.Take out moisture gel cross-linked polymer after 0 minute at polyase 13.The moisture gel cross-linked polymer of gained has been milled to the about 5mm of size or littler.
This moisture gel cross-linked polymer that grinds is spread out on 50 purpose wire nettings, and in 180 ℃ of hot blasts dry 50 minutes.Use the broken dry thing of roller abrasive dust, and use the JIS standard screen of aperture openings size 710 μ m and 175 μ m to carry out classification.Thus, water absorbing resin particle (7) has the shape of pulverizing brokenly.The quality average particle size particle size D50 of particle (7) is 471 μ m.The logstandard deviation of the particle size distribution of particle (7), σ ζ are 0.37.The centrifugal water holding capacity (CRC) of water absorbing resin particle (7) is the polymer content that 38.0g/g and the water that contains 11.0 quality % can extract.
The water absorbing resin particle (7) of 100 mass parts that obtain evenly mixes with surface crosslinking agent, and said crosslinking agent is 1 of 0.3 mass parts, the propane diols of 4-butanediol, 0.5 mass parts and the pure water mixed solution of 2.7 mass parts.Then 212 ℃ of thermally treated mixtures 40 minutes.The division particle can be of a size of the JIS standard screen of 850 μ m through aperture openings until it.Subsequently, the particle of division carries out coating vibration-testing 1 to obtain surface-crosslinked water absorbing resin particle (7-40).
Add a kind of water absorbing resin particle (7-40) of acquisition of solution to 100 mass parts then respectively.Said solution is the mixture of propane diols of sodium lactate aqueous solution and 0.002 mass parts of 60 quality % of aluminum sulfate aqueous solution (the aluminium oxide aqueous solution that is equivalent to 8 quality %), 0.134 mass parts of 27.5 quality % of 0.40 mass parts.After adding solution, said sample in 60 ℃ no wind environment dry 1 hour.After drying, the division sample can be of a size of the JIS standard screen of 710 μ m through aperture openings until it.Subsequently, make the sample of division carry out coating vibration-testing 2 to obtain water absorbing resin particle (7-40A).
Add water absorbing resin particle (7-40A) sample of the HDK available from Wa Ke company (registration mark) H20 to 100 mass parts of different amounts: amount part is with preparation water absorbing agent (7-2); Add 0.070 mass parts with preparation water absorbing agent (7-3), and add 0.100 mass parts with preparation water absorbing agent (7-4).
Table 6 shows the kind and the quantity of the silica of interpolation, and water absorbing resin particle (7), (7-40) and (7-40A) and the measurement result of water absorbing agent (7-1), (7-2), (7-3) and CRC (7-4), AAP, SFC, FHA, LDV, D50 and be of a size of the proportion of particles of the sieve of 150 μ m through aperture openings.Also measured the amount of dust, its result has been shown in the table 6.
Embodiment 8
The water absorbing resin particle (7-40A) that adds 100 mass parts that prepare among the HDK available from Wa Ke company (registration mark) H20 to embodiment 7 of 0.200 mass parts is to obtain water absorbing agent (8-1).
Add 0.200 mass parts available from the water absorbing resin particle (7-40A) of 100 mass parts of preparation among the Aerosil (registration mark) 200 to embodiment 7 of Japanese Aerosil Co., Ltd to obtain water absorbing agent (8-2).
Add 0.200 mass parts available from the water absorbing resin particle (7-40A) of 100 mass parts of preparation among Aerosil (registration mark) R-972 to embodiment 7 of Japanese Aerosil Co., Ltd to obtain water absorbing agent (8-3).
Table 6 shows the kind and the quantity of the silica of interpolation, and the measurement result of water absorbing agent (8-1), (8-2) and CRC (8-3), AAP, SFC, FHA, LDV, D50 and be of a size of the proportion of particles of the sieve of 150 μ m through aperture openings.Also measured the amount of dust, its result has been shown in the table 6.
Figure G2007800109479D00701
Water absorbing agent in the table 6 (7-1) to (7-4) and (8-1) show that the water absorbing agent of acquisition produces very small amount of dust and demonstrates high-caliber SFC to the measurement result of (8-3).Any water absorbing agent (7-1) to (7-4) and (8-1) be less than or equal to 400ppm to the amount of the dust of (8-3).The water absorbing agent of preparation can not produce dust.
Water absorbing agent (7-1) to (7-4) demonstrates good especially AAP and FHA.Water absorbing agent (7-1) to (7-4), (8-1) and (8-2) demonstrate excellent LDV.The amount of water absorbing agent (7-1) to the dust of (7-3) is low especially, and some is low for the amount of the dust of water absorbing agent (7-4).Water absorbing agent (8-1) and (8-3) have low Dust Capacity equally.Though silica to the water absorbing agent (8-1) that has added same amount is to (8-3), water absorbing agent (8-2) than water absorbing agent (8-1) and (8-3) produces more dust and demonstrates lower AAP and SFC.
Embodiment 9
At the polypropylene containers that is coated with styrenic foams (heat-insulating material) (internal diameter 80mm; 1 liter of internal capacity) mixed solution (A) and solution (B) in.When using magnetic stirrer to stir, in open system, promptly mix through adding solution (B) to solution (A).Solution (A) is the mixture of diethylene triamine pentacetic acid (DTPA) five sodium water solutions of 1.0 quality % of polyethyleneglycol diacrylate (molecular weight 523) and the 1.35g of 221.92g acrylic acid, 1.53g.Solution (B) is the mixture of ion exchange water of sodium hydrate aqueous solution and 182.55g of the 48.5 quality % of 180.33g, and its temperature is adjusted to 50 ℃.The result who mixes is a kind of monomer solution, because the heat of neutralization has been increased to about 100 ℃ with the analgesic temperature wherein of branch.
The sodium persulfate aqueous solution of the 3 quality % of interpolation 12.32g is to the monomer solution that obtains.After stirring several seconds, solution is poured in the rustless steel container of the pellet type in the open system.In when falling solution, container is heated so that surface temperature reaches 100 ℃ on a heat dish (Neo heat dish H1-1000 is by As One manufactured).Container has a bottom (250x250mm), and the inboard of container is coated with Teflon (registration mark).Its top is 640x640mm, highly is 50mm.The cross section of intermediate portion is trapezoidal.Its top is an opening.
Be poured in the pallet soon at monomer solution, polymerization begins.Produce steam during polymerization is carried out, solution is in all directions foaming/expansion.Subsequently, content is contracted to the size of being a bit larger tham the tray bottom.Expand and contraction completion in 1 minute.In container, keep after 4 minutes, remove aqueous polymers.
The aqueous polymers of aqueous polymers that meat grinder (by the imperial meat grinder VR400K of the Iidzuka Industrial Co., Ltd manufacturing) crushing of using square to be of a size of 9.5mm obtains to obtain to grind.
This moisture gel cross-linked polymer that grinds is spread out on 50 purpose wire nettings, and in 180 ℃ of hot blasts dry 50 minutes.In the roller mill, pulverize dry thing then, and use the JIS standard screen of aperture openings size 710 μ m and 175 μ m to carry out classification.Thus, water absorbing resin particle (9) has the shape of pulverizing brokenly.The quality average particle size particle size D50 of particle (9) is 342 μ m.The logstandard deviation of the particle size distribution of particle (9), σ ζ are 0.34.The centrifugal water holding capacity (CRC) of water absorbing resin particle (9) is the polymer content that 31.0g/g and the water that contains 8.0 quality % can extract.
The water absorbing resin particle (9) of 100 mass parts that obtain mixes with surface crosslinking agent equably, and said crosslinking agent is 1 of 0.31 mass parts, the propane diols of 4-butanediol, 0.49 mass parts and the pure water mixed solution of 2.4 mass parts.Then 195 ℃ of thermally treated mixtures 50 minutes.The particle that division produces can be of a size of the JIS standard screen of 710 μ m through aperture openings until it.Subsequently, make the particle of division carry out coating vibration-testing 1 to obtain surface-crosslinked water absorbing resin particle (9-50).
Add a kind of surface-crosslinked water absorbing resin particle (9-50) of acquisition of solution to 100 mass parts.Said solution is the mixture of propane diols of sodium lactate aqueous solution and 0.0025 mass parts of 60 quality % of aluminum sulfate aqueous solution (the aluminium oxide aqueous solution that is equivalent to 8 quality %), 0.16 mass parts of 27.5 quality % of 0.40 mass parts.After adding solution, particle in 60 ℃ no wind environment dry 1 hour.After drying, the division sample can be of a size of the JIS standard screen of 710 μ m through aperture openings until it.Subsequently, make the particle of division carry out coating vibration-testing 2 to obtain water-absorbing resin (9-50A).
Add the sample of water absorbing resin particle (9-50A) of the HDK available from Wa Ke company (registration mark) H20 to 100 mass parts of different amounts: the HDK that adds 0.020 mass parts to one of sample with preparation water absorbing agent (9-1); Add 0.040 mass parts with preparation water absorbing agent (9-2), add 0.070 mass parts to prepare water absorbing agent (9-3) and to add 0.100 mass parts with preparation water absorbing agent (9-4).
Add the sample of water absorbing resin particle (9-50A) of acquisition of Aerosil (registration mark) R-972 to 100 mass parts of making by Japanese Aerosil Co., Ltd of different amounts: the Aerosil that adds 0.040 mass parts to one of sample with preparation water absorbing agent (9-5); Add 0.070 mass parts with preparation water absorbing agent (9-6), and add 0.100 mass parts with preparation water absorbing agent (9-7).
Add the sample of water absorbing resin particle (9-50A) of the HDK available from Wa Ke company (registration mark) H15 to 100 mass parts of different amounts: the HDK that adds 0.020 mass parts to one of sample with preparation water absorbing agent (9-8); Add 0.040 mass parts with preparation water absorbing agent (9-9), add 0.070 mass parts to prepare water absorbing agent (9-10) and to add 0.100 mass parts with preparation water absorbing agent (9-11).
Table 7 shows the kind and the quantity of the silica of interpolation, and water absorbing resin particle (9), (9-50) and (9-50A) and the measurement result of the CRC of water absorbing agent (9-1) to (9-11), AAP, SFC, FHA, LDV, D50 and be of a size of the proportion of particles of the sieve of 150 μ m through aperture openings.Also measured the amount of dust, its result has been shown in the table 7.
Figure G2007800109479D00741
The contrast of water absorbing agent in the table 7 (9-1) to (9-4) clearly illustrates that SFC improves along with the increase of the quantity of the silica that adds.For the situation of water absorbing agent (9-5) to (9-7) and water absorbing agent (9-8) to (9-11) too.
As shown in table 7, the amount of any water absorbing resin particle (9-50A) and water absorbing agent (9-1) to the dust of (9-11) is less than or equal to 300ppm.The water absorbing agent of preparation can not produce dust.
Water absorbing agent (9-1) to (9-4) and (9-8) demonstrate excellent LDV to (9-11).
Embodiment 10
With 425.2g acrylic acid, 4, the PAA aqueous solution of 499.5g37 quality %, 538.5g pure water and 6.17g polyethyleneglycol diacrylate (molecular weight 523) are dissolved in the reactor (10 liters of internal capacities) that adds upper cover on the stainless die both arms of the jacketed type kneader with two ∑ type blades and form with preparation feedback liquid.Then, under nitrogen atmosphere to this reactant liquor deaeration 20 minutes.Subsequently, when stirring, in reactant liquor, add the sodium persulfate aqueous solution of 28.3g10 quality % and the L-aqueous ascorbic acid of 23.6g0.1 quality %, after it is 1 minute, begin polymerization.When the gel that crushing generates, make and be aggregated in 25-95 ℃ and carry out.Take out moisture gel cross-linked polymer after 0 minute at polyase 13.The moisture gel cross-linked polymer of gained has been milled to the about 5mm of size or littler.
This moisture gel cross-linked polymer that grinds is spread out on 50 purpose wire nettings, and in 170 ℃ of hot blasts dry 65 minutes.Use the broken dry thing of roller abrasive dust, and use the JIS standard screen of aperture openings size 850 μ m to carry out classification.Thus, water absorbing resin particle (10) has the shape of pulverizing brokenly.The quality average particle size particle size D50 of particle (10) is 458 μ m.The logstandard deviation of the particle size distribution of particle (10), σ ζ are 0.40.The centrifugal water holding capacity (CRC) of water absorbing resin particle (10) is the polymer content that 42g/g and the water that contains 13 quality % can extract.
The water absorbing resin particle (10) of 100 mass parts that obtain mixes with surface crosslinking agent equably, and said crosslinking agent is 1 of 0.35 mass parts, the propane diols of 4-butanediol, 0.5 mass parts and the pure water mixed solution of 3.0 mass parts.Then 212 ℃ of thermally treated mixtures 40 minutes.The division particle can be of a size of the JIS standard screen of 850 μ m through aperture openings until it.Subsequently, the particle of division carries out coating vibration-testing 1 to obtain water absorbing resin particle (10) surface-crosslinked or that apply.
Add a kind of water absorbing resin particle (10) surface-crosslinked or that apply of solution to 100 mass parts then.Said solution is the mixture of propane diols of sodium lactate aqueous solution and 0.025 mass parts of 60 quality % of aluminum sulfate aqueous solution (the aluminium oxide aqueous solution that is equivalent to 8 quality %), 0.134 mass parts of 27.5 quality % of 0.9 mass parts.After adding solution, said particle in 60 ℃ no wind environment dry 1 hour.After drying, the division sample can be of a size of the JIS standard screen of 850 μ m through aperture openings until it.The water absorbing resin particle that is obtained by water absorbing resin particle (10) is designated as (10-A).
Add mixing with preparation water absorbing agent (10) of 0.20 mass parts available from the water absorbing resin particle (10-A) of 100 mass parts of Aerosil (registration mark) 200 to the above-mentioned acquisition of Japanese Aerosil Co., Ltd and with it.Table 8 shows the kind and the quantity of the water-insoluble inorganic particle of interpolation, and the measurement result of the CRC of water absorbing resin particle (10-A) and water absorbing agent (10), AAP, SFC, D50 and be of a size of proportion of particles and the amount of dust of the sieve of 150 μ m through aperture openings.
Embodiment 11
Add mixing to obtain water absorbing agent (11) of 0.30 mass parts available from the water absorbing resin particle (10-A) of 100 mass parts of preparation among the Aerosil (registration mark) 200 to embodiment 10 of Japanese Aerosil Co., Ltd and with it.Table 8 shows the kind and the quantity of the water-insoluble inorganic particle of interpolation, and the measurement result of the CRC of the water absorbing agent (11) that obtains, AAP, SFC, D50 and be of a size of proportion of particles and the quantity of dust of the sieve of 150 μ m through aperture openings.
Embodiment 12
Use with embodiment 10 in the moisture gel cross-linked polymer that grinds until acquisition of identical method.
This moisture gel cross-linked polymer that grinds is spread out on 50 purpose wire nettings, and in 170 ℃ hot blast dry 65 minutes.Use the broken dry thing of roller abrasive dust, and use the JIS standard screen of aperture openings size 850 μ m to carry out classification.Thus, water absorbing resin particle (12) has the shape of pulverizing brokenly.The quality average particle size particle size D50 of particle (12) is 330 μ m.The logstandard deviation of the particle size distribution of particle (12), σ ζ are 0.35.The centrifugal water holding capacity (CRC) of water absorbing resin particle (12) is the polymer content that 42g/g and the water that contains 13 quality % can extract.
The water absorbing resin particle (12) of 100 mass parts that obtain mixes with surface crosslinking agent equably, and said crosslinking agent is 1 of 0.35 mass parts, the propane diols of 4-butanediol, 0.55 mass parts and the pure water mixed solution of 3.0 mass parts.Then 212 ℃ of thermally treated mixtures 40 minutes.The particle that division produces can be of a size of the JIS standard screen of 850 μ m through aperture openings until it.Subsequently, the particle of division carries out coating vibration-testing 1 to obtain water absorbing resin particle (12) surface-crosslinked or that apply.
Add a kind of water absorbing resin particle (12) surface-crosslinked or that apply of solution to 100 mass parts then.Said solution is the mixture of propane diols of sodium lactate aqueous solution and 0.025 mass parts of 60 quality % of aluminum sulfate aqueous solution (the aluminium oxide aqueous solution that is equivalent to 8 quality %), 0.134 mass parts of 27.5 quality % of 0.9 mass parts.After adding solution, said particle in 60 ℃ no wind environment dry 1 hour.After drying, the division particle can be of a size of the JIS standard screen of 850 μ m through aperture openings until it.The water absorbing resin particle that is obtained by water absorbing resin particle (12) is designated as (12-A).
Add mixing with preparation water absorbing agent (3C) of 0.20 mass parts available from the water absorbing resin particle (12-A) of 100 mass parts of Aerosil (registration mark) 200 to the above-mentioned acquisition of Japanese Aerosil Co., Ltd and with it.Table 8 shows the kind and the quantity of the water-insoluble inorganic particle of interpolation, and the measurement result of the CRC of water absorbing agent (12), AAP, SFC, D50 and be of a size of proportion of particles and the amount of dust of the sieve of 150 μ m through aperture openings.
Embodiment 13
Add the water absorbing resin particle (10) surface-crosslinked or that apply for preparing among a kind of embodiment 10 of material to 100 mass parts.Said material be 27.5 quality % of 0.9 mass parts aluminum sulfate aqueous solution (the aluminium oxide aqueous solution that is equivalent to 8 quality %), 0.134 mass parts 60 quality % sodium lactate aqueous solution, 0.025 mass parts propane diols and as a kind of Theaceae plant (" FS-80MO " that contains polyphenol and caffeine that is derived from of a kind of 15 quality % of 0.5 mass parts of plant component; Can obtain from Shiraimatsu pharmaceutical Co. Ltd; Be positioned at 37-1; Ukawa; The mixture of the aqueous solution of the extract of leaf Mizuguchi-cho, Kouga-gun, Shiga)).After adding said material, said particle in 60 ℃ no wind environment dry 1 hour.After drying, the division particle can be of a size of the JIS standard screen of 850 μ m through aperture openings until it, is designated as (13-A) with the preparation water absorbing resin particle.
Add mixing with preparation water absorbing agent (13) of 0.20 mass parts available from the water absorbing resin particle (13-A) of 100 mass parts of Aerosil (registration mark) 200 to the above-mentioned acquisition of Japanese Aerosil Co., Ltd and with it.Table 8 shows the kind and the quantity of the water-insoluble inorganic particle of interpolation, and the measurement result of the CRC of water absorbing agent (13), AAP, SFC, D50 and be of a size of proportion of particles and the amount of dust of the sieve of 150 μ m through aperture openings.
Embodiment 14
Add the water absorbing resin particle (12) surface-crosslinked or that apply for preparing among a kind of embodiment 12 of material to 100 mass parts.Said material be 27.5 quality % of 0.9 mass parts aluminum sulfate aqueous solution (the aluminium oxide aqueous solution that is equivalent to 8 quality %), 0.134 mass parts 60 quality % sodium lactate aqueous solution, 0.025 mass parts propane diols and as a kind of Theaceae plant (" FS-80MO " that contains polyphenol and caffeine that is derived from of a kind of 15 quality % of 0.5 mass parts of plant component; Can obtain from Shiraimatsu pharmaceutical Co. Ltd; Be positioned at 37-1; Ukawa; The mixture of the aqueous solution of the extract of leaf Mizuguchi-cho, Kouga-gun, Shiga)).After adding said material, said particle in 60 ℃ no wind environment dry 1 hour.After drying, the division particle can be of a size of the JIS standard screen of 850 μ m through aperture openings until it, is designated as (14-A) with the preparation water absorbing resin particle.
Add mixing with preparation water absorbing agent (14) of 0.20 mass parts available from the water absorbing resin particle (14-A) of 100 mass parts of Aerosil (registration mark) 200 to the above-mentioned acquisition of Japanese Aerosil Co., Ltd and with it.Table 8 shows the kind and the quantity of the water-insoluble inorganic particle of interpolation, and the measurement result of the CRC of water absorbing agent (14), AAP, SFC, D50 and be of a size of proportion of particles and the amount of dust of the sieve of 150 μ m through aperture openings.
The comparative example 3
Add mixing to obtain contrast water absorbing agent (3) of 0.20 mass parts available from the water absorbing resin particle (10) of 100 mass parts of preparation among the Aerosil (registration mark) 200 to embodiment 10 of Japanese Aerosil Co., Ltd and with it.Table 8 shows the kind and the quantity of the water-insoluble inorganic particle of interpolation, and the measurement result of the CRC of the water absorbing agent (3) that obtains, AAP, SFC, D50 and be of a size of proportion of particles and the amount of dust of the sieve of 150 μ m through aperture openings.
The comparative example 4
Add mixing to obtain contrast water absorbing agent (4) of 0.30 mass parts available from the water absorbing resin particle (10) of 100 mass parts of preparation among the Aerosil (registration mark) 200 to embodiment 10 of Japanese Aerosil Co., Ltd and with it.Table 8 shows the kind and the quantity of the water-insoluble inorganic particle of interpolation, and the measurement result of the CRC of the water absorbing agent (4) that obtains, AAP, SFC, D50 and be of a size of proportion of particles and the amount of dust of the sieve of 150 μ m through aperture openings.
The comparative example 5
Use with embodiment 10 in the moisture gel cross-linked polymer that grinds until acquisition of identical method.
This moisture gel cross-linked polymer that grinds is spread out on 50 purpose wire nettings, and in 170 ℃ hot blast dry 65 minutes.Use the broken dry thing of roller abrasive dust, and use the JIS standard screen of aperture openings size 850 μ m to carry out classification.Thus, contrast water absorbing resin particle (5) has the shape of pulverizing brokenly.Comparative particle's (5) quality average particle size particle size D50 is 440 μ m.The logstandard deviation of comparative particle's (5) particle size distribution, σ ζ are 0.50.The centrifugal water holding capacity (CRC) of contrast water absorbing resin particle (5) is the polymer content that 42g/g and the water that contains 13 quality % can extract.
The water absorbing resin particle (5) of 100 mass parts that obtain mixes with surface crosslinking agent equably, and said crosslinking agent is 1 of 0.35 mass parts, the propane diols of 4-butanediol, 0.55 mass parts and the pure water mixed solution of 3.0 mass parts.Then 212 ℃ of thermally treated mixtures 40 minutes.
The particle that division produces can be of a size of the JIS standard screen of 850 μ m through aperture openings until it.Subsequently, the particle of division carries out coating vibration-testing 1 to obtain contrast water absorbing resin particle (5) surface-crosslinked or that apply.
Add a kind of contrast water absorbing resin particle (5) surface-crosslinked or that apply of solution to 100 mass parts then.Said solution is the mixture of propane diols of sodium lactate aqueous solution and 0.025 mass parts of 60 quality % of aluminum sulfate aqueous solution (the aluminium oxide aqueous solution that is equivalent to 8 quality %), 0.134 mass parts of 27.5 quality % of 0.9 mass parts.After adding solution, said particle in 60 ℃ no wind environment dry 1 hour.After drying, the division sample can be of a size of the JIS standard screen of 850 μ m through aperture openings until it.The contrast water absorbing resin particle that is obtained by contrast water absorbing resin particle (5) is designated as (5-A).
Add mixing with preparation contrast water absorbing agent (5) of 0.20 mass parts available from the contrast water absorbing resin particle (5-A) of 100 mass parts of Aerosil (registration mark) 200 to the above-mentioned acquisition of Japanese Aerosil Co., Ltd and with it.Table 8 shows the kind and the quantity of the water-insoluble inorganic particle of interpolation, and contrast water absorbing resin particle (5-A) is of a size of the proportion of particles and the Dust Capacity of the sieve of 150 μ m with the measurement result of the CRC that contrasts water absorbing agent (5), AAP, SFC, D50 with through aperture openings.
Figure G2007800109479D00811
Water absorbing agent in the table 8 (10) shows the amount of both using multivalent metal salt also to use the water-insoluble inorganic particle in restriction AAP degradation, also can improve SFC and reducing dust with contrast water absorbing agent (3) and water absorbing agent (11) with the contrast that contrasts water absorbing agent (4).In addition, the contrast of water absorbing agent (10) and contrast water absorbing agent (5) be illustrated in through aperture openings be of a size of the proportion of particles of sieve of 150 μ m when high SFC can reduce.
In addition, the water absorbing resin particle and the water absorbing agent that have added aluminum sulfate produce a spot of dust and demonstrate excellent SFC and AAP.
Table 9 show above-mentioned water absorbing agent with the contrast water absorbing agent dust in SiO 2The measurement result of the waving property of content and dust.
Figure G2007800109479D00831
Be appreciated that the SiO in dust according to table 9 2When content hangs down, can not produce dust.Also be appreciated that the SiO in the dust 2Content is low more, and the possibility that produces dust is more little.
For example, the SiO in the dust 2Content is preferably 50 quality % or lower, 30 quality % or lower more preferably, even 15 quality % or lower more preferably, and also 10 quality % or lower more preferably most preferably are 7 quality % or lower.
The invention is not restricted to the description of above-mentioned embodiment, those skilled in the art can change within the scope of the claims.Embodiment based on the appropriate combination of disclosed technological means in the different embodiments is also included within the technical scope of the present invention.
Practicality
Have the excellent water-absorbing characteristic and can not produce dust according to water absorbing agent of the present invention and water absorbent core and through the water absorbing agent that the preparation method who is used for water absorbing agent according to the present invention obtains, so it is applicable to the suction/water-loss reducer of various purposes.
Some application be exemplified as the suction/water-loss reducer that is used for absorbing articles such as disposable diaper, sanitary napkin, incontinence protection and medical protection pad etc.; Use water-loss reducer such as agricultural/horticulturals such as the lasting agent of sphagna substitute, soil conditioner, water-loss reducer and pesticide effectiveness; Such as the for building water-loss reducer of interior dress wall material with anti-agglomerating agent and cement additire; Release control agent; Cold-retaining agent; The disposable body warmer; The mud coagulating agent; Shelflife-improving agent for food; The ion-exchange column material; The dehydrating agent of mud/oil; Drier; And humidity adjustment agent.
Water absorbing agent of the present invention can be suitable for absorbing the disposable diaper, sanitary napkin of excrement, urine or blood and similar cleaning/hygienic material especially.

Claims (22)

1. the water absorbing agent of the water absorbing resin particle that obtains of a polymerization that contains through water-soluble unsaturated monomer with internal crosslinking structure, said water absorbing agent satisfies following condition (a) to (d):
(a) said water absorbing agent contains with respect to absorb water dosage from 10ppm to 1, the water-insoluble inorganic particle of 900ppm;
(b) said water absorbing agent contains 5 quality % or lower and has the particle of size that is of a size of the sieve of 150 μ m through aperture openings;
(c) under the pressure of 4.83kPa, the water absorbing capacity of said water absorbing agent is 18g/g to 30g/g; And
(d) the water-insoluble inorganic particle remains on the surface of water-absorbing resin or near surface,
Wherein, said water-insoluble inorganic particle is a silica; And
The concentration of the silanol group that silica is residual in its surface is 1.7SiOH/nm 2Or it is lower.
2. water absorbing agent according to claim 1 is characterized in that said water-insoluble inorganic particle accounts for the 10ppm to 990ppm of water absorbing agent.
3. according to one of claim 1 and 2 described water absorbing agent, it is characterized in that said water-insoluble inorganic particle contains the amino that remains at least on the particle surface.
4. according to one of claim 1 and 2 described water absorbing agent, it is characterized in that the salt solution water conservancy diversion rate of said water absorbing agent is 30 (10 -7Cm 3Sg -1) or higher.
5. according to one of claim 1 and 2 described water absorbing agent, it is characterized in that the absorbability of said water absorbing agent under 4.83kPa pressure is 20g/g to 30g/g.
6. according to claim 1 and one of 2 described water absorbing agents, it is characterized in that, said water absorbing agent also at least amount from the three value water-soluble multivalent metal salts of 0.1 quality % to 1 quality %.
7. water absorbing agent according to claim 6 is characterized in that, said water-soluble multivalent metal salt is an aluminum sulfate.
8. according to one of claim 1 and 2 described water absorbing agent, it is characterized in that said water absorbing resin particle contains the particle with loose structure.
9. according to one of claim 1 and 2 described water absorbing agent, it is characterized in that the quality average particle size particle size of said water absorbing agent is 200 μ m to 500 μ m, the logstandard deviation of particle size distribution, σ ζ are 0.20 to 0.40.
10. according to one of claim 1 and 2 described water absorbing agent, it is characterized in that the liquid distribution speed of said water absorbing agent is that 0.2 (mm/sec) is to 10.0 (mm/sec).
11., it is characterized in that said water absorbing agent has negative triboelectric charge according to one of claim 1 and 2 described water absorbing agent.
12., it is characterized in that said water absorbing agent contains calculates 300ppm or lower dust in mass according to one of claim 1 and 2 described water absorbing agent.
13., it is characterized in that said water absorbing agent contains SiO in the dust according to one of claim 1 and 2 described water absorbing agent 2Amount be 50 quality % or lower dust.
14. water absorbing agent according to claim 1 is characterized in that, said water absorbing agent obtains through comprising the preparation method that water absorbing resin particle is bestowed the step of silica being mixed with it after the mechanical damage.
15. water absorbing agent according to claim 1 is characterized in that, said water absorbing agent mixes preparation method's acquisition of the step of back pneumatic transportation silica and water absorbing resin particle through being included in silica with water absorbing resin particle.
16. the water absorbing agent of the water absorbing resin particle that a polymerization that contains through water-soluble unsaturated monomer obtains, said water absorbing agent satisfies following condition (A) to (D):
(A) said particle near surface crosslinked have or be coated with have monohydroxy at least surface crosslinking agent;
(B) said particle at least from the teeth outwards or near surface contain multivalent metal salt and water-insoluble inorganic particle;
(C) the quality average particle size particle size of said water absorbing agent is 200 μ m to 500 μ m; And
(D) said water absorbing agent contains 5 quality % or lower and has the particle of size that is of a size of the sieve of 150 μ m through aperture openings,
Wherein, said water-insoluble inorganic particle is a silica; And
The concentration of the silanol group that silica is residual in its surface is 1.7SiOH/nm 2Or it is lower.
17. water absorbing agent according to claim 16 is characterized in that, said multivalent metal salt accounts for 0.01 quality % to 1 quality % of water absorbing agent.
18., it is characterized in that said water-insoluble inorganic particle accounts for 0.001 quality % to 0.4 quality % of water absorbing agent according to one of claim 16 and 17 described water absorbing agent.
19. according to one of claim 16 and 17 described water absorbing agent, it is characterized in that,
The centrifugal hold facility of said water absorbing agent is 30g/g to 50g/g, and salt solution water conservancy diversion rate is 10 (10 -7Cm 3Sg -1) or higher.
20., it is characterized in that said water absorbing agent contains SiO in the dust according to one of claim 16 and 17 described water absorbing agent 2Amount be 50 quality % or lower dust.
21. a suction core, said core contains the described water absorbing agent of one of claim 1 to 2.
22. a method for preparing the water absorbing agent of the water absorbing resin particle that the polymerization that contains through water-soluble unsaturated monomer obtains, the quality average particle size particle size of said water absorbing resin particle is 200 μ m to 500 μ m,
Said method comprises following continuous step:
(1) uses that to have a monohydroxy at least surface crosslinking agent crosslinked or apply water absorbing resin particle at the near surface of water absorbing resin particle; And
(2) multivalent metal salt and water-insoluble inorganic particle are mixed with water absorbing resin particle,
Wherein, said water-insoluble inorganic particle is a silica; And
The concentration of the silanol group that silica is residual in its surface is 1.7SiOH/nm 2Or it is lower.
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EP3115382B1 (en) * 2010-04-07 2019-07-10 Nippon Shokubai Co., Ltd. Method for producing water absorbent polyacrylic acid (salt) resin powder, and water absorbent polyacrylic acid (salt) resin powder
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EP2781259B1 (en) * 2011-11-15 2021-07-07 Nippon Shokubai Co., Ltd. Water absorbent composition and method for producing same, as well as storage and stocking method for same
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JP2016027070A (en) * 2014-06-23 2016-02-18 ザ プロクター アンド ギャンブルカンパニー Absorbent resin and method for producing the same
KR101596623B1 (en) * 2015-01-30 2016-02-22 에스케이이노베이션 주식회사 Water-absorbing resin and preparing method thereof
KR20170132800A (en) * 2015-03-30 2017-12-04 가부시키가이샤 닛폰 쇼쿠바이 Particulate absorbent
JP7471295B2 (en) * 2019-07-05 2024-04-19 住友精化株式会社 Method for producing water-absorbent resin particles and aqueous monomer solution
CN111819944B (en) * 2020-07-21 2023-06-06 鲁东大学 Desalting method for repairing saline soil by combining plant bionic and salt crystallization inhibitor
CN112352493B (en) * 2020-10-24 2022-05-13 湖南高尔园林绿化工程有限公司 Sponge urban ecological moisturizing system and application thereof in urban engineering

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1455802A (en) * 2001-01-26 2003-11-12 株式会社日本触媒 Water absorbing agent and method for production thereof and water absorbing article

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6107358A (en) * 1996-08-23 2000-08-22 Nippon Shokubai Co., Ltd. Water-absorbent resin and method for production thereof
US6927268B2 (en) * 2000-06-21 2005-08-09 Nippon Shokubai Co., Ltd. Production process for water-absorbent resin
JP4749679B2 (en) * 2003-05-09 2011-08-17 株式会社日本触媒 Water absorbent resin and method for producing the same

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1455802A (en) * 2001-01-26 2003-11-12 株式会社日本触媒 Water absorbing agent and method for production thereof and water absorbing article

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