JP2019025470A - Absorbent complex - Google Patents

Abstract

To provide an absorbent complex having excellent liquid absorbency and excellent durability under a wet condition.SOLUTION: An absorbent complex contains a nonionic crosslinked polymer and an absorptive base material. The absorptive base material contains a surface layer member and a thermal fusion fiber. The thermal fusion fiber has a melting temperature of 70-200°C. In the absorbent complex, an absorption core containing the nonionic crosslinked polymer and thermal fusion fiber is covered with the surface layer member.SELECTED DRAWING: None

Description

The present invention relates to an absorbent composite. More specifically, the present invention relates to an absorbent composite suitable for an ink absorbent, a cosmetic, a deodorant and the like.

Conventionally, water-absorbing materials mainly composed of polyacrylic acid (salt) have been developed. Sanitary field such as diapers and sanitary products, medical field, civil engineering / architectural field, food field, industrial field, soil It is used in a wide variety of fields such as modifiers, agriculture and horticulture.
For example, Patent Documents 1 and 2 disclose an absorbent composite or an ink absorber including a crosslinked body mainly composed of polyacrylic acid (salt) and a base material.

JP 2008-86590 A JP 2009-274302 A

As described above, various absorptive composites (ink absorbers) have been disclosed. However, conventional absorptive composites having a structure in which an absorbent core containing an absorbent resin and a binder is sandwiched between surface sheets are heat-resistant. , The binder is fused between the surface layer sheets, and the space between the surface layer sheets is restricted, so that the swelling of the absorbent resin due to the liquid absorption is restricted and the liquid absorption property is poor. Furthermore, when the binder coats the absorbent resin, the solution is less likely to come into contact with the absorbent resin and the liquid absorption is inhibited, or the swelling of the absorbent resin due to the liquid absorption is restricted, resulting in poor liquid absorption. It was. In addition, when the binder is not used or the amount of the binder is small, the swelling of the absorbent resin due to the liquid absorption is difficult to regulate, but when the absorbent composite is wetted by the liquid absorption, peeling occurs between the absorbent core and the surface layer sheet, It was inferior in durability.

This invention is made | formed in view of the said present condition, and aims at providing the absorptive composite_body | complex excellent in liquid absorbency and durability at the time of wetness.

The present inventor has made various studies on the absorbent composite, and as a result, the absorbent composite having a structure in which the absorbent core including the nonionic crosslinked polymer and the heat-fusible fiber is covered with the surface layer member is liquid absorbing and wet. I found it to be excellent in durability and time. Specifically, since the absorbent composite of the present invention has the above structure, the absorbent core and the surface layer member are bonded while maintaining a space that can be sufficiently swollen when the nonionic crosslinked polymer absorbs liquid. The present inventors have found that the state can be sufficiently maintained and have conceived that the above-mentioned problems can be solved brilliantly, and have reached the present invention.

That is, the present invention is an absorptive composite comprising a nonionic crosslinked polymer and an absorbent base material, wherein the absorbent base material includes a surface layer member and a heat fusion fiber, and the heat fusion fiber is melted. A temperature is 70-200 degreeC, and the said absorptive composite_body | complex is an absorptive composite_body | complex with which the absorption core containing this nonionic crosslinked polymer and a heat-fusion fiber is covered with the surface layer member.

The absorbent base further includes other fibers other than the heat-fusible fiber, and the absorbent composite includes a nonionic crosslinked polymer, a heat-fusible fiber, and other fibers other than the heat-fusible fiber. However, it is preferable that the surface layer member is covered.

The nonionic crosslinked polymer preferably has a structural unit derived from an amide monomer and / or a (poly) alkylene glycol monomer.

The other fibers preferably include hydrophilic fibers.
The hydrophilic fiber is preferably at least one selected from the group consisting of cellulosic fibers, polyamide fibers, animal fibers, and hydrophobic fibers having a hydrophilic surface.
The surface layer member is preferably in the form of a sheet or a bag.

The absorbent composite of the present invention has the above-described configuration, and can sufficiently exhibit both excellent liquid absorbency and durability when wet, so that it can be used in ink absorbents, cosmetics, deodorants, and the like. It can be used suitably.

Although the preferable form of this invention is demonstrated concretely below, this invention is not limited only to the following description, In the range which does not change the summary of this invention, it can change suitably and can apply. In addition, the form which combined each preferable form of this invention described below 2 or 3 or more also corresponds to the preferable form of this invention.

<Absorptive complex>
The absorbent composite of the present invention includes a nonionic crosslinked polymer and an absorbent base material.
In the absorptive composite, the mass ratio of the nonionic crosslinked polymer to the absorbing base material (nonionic crosslinked polymer / absorbing base material) is not particularly limited, but is preferably 0.1 to 15. If the mass ratio of the nonionic crosslinked polymer to the absorbent base is 0.1 or more, the nonionic crosslinked polymer can receive the liquid absorbed by the absorbent base more sufficiently. It is possible to sufficiently prevent the liquid from leaking out. If the said mass ratio is 15 or less, the quantity of the absorption base material with respect to a nonionic crosslinked polymer will become enough, and the liquid absorption rate of an absorptive composite will improve more.
More preferably, the mass ratio is 0.2 to 15.
When the absorptive complex has a planar shape such as a sheet, the absorptive complex is more preferably a mass ratio of the nonionic crosslinked polymer to the absorbent base material of 0.2 to 5. . More preferably, it is 0.5-3, Most preferably, it is 0.7-3.
When the absorbent composite has a planar bag shape, the absorbent composite preferably further has a mass ratio of 1 to 7 between the nonionic crosslinked polymer and the absorbent base material. More preferably, it is 2-5.
When the absorptive complex has a three-dimensional bag shape such as a pyramid shape, the absorptive complex preferably has a mass ratio of 3 to 15 between the nonionic crosslinked polymer and the absorbent base material. More preferably, it is 5-10.

The absorbent composite preferably has a heat-sealing fiber content of 1 to 50% by mass with respect to 100% by mass of the nonionic crosslinked polymer. As a result, the nonionic crosslinked polymer absorbs the liquid and swells sufficiently, and the balance between the absorption core and the adhesion between the surface layer member is further improved, and the liquid absorption and durability when wet are superior. Become. More preferably, it is 5-30 mass%.

The said absorptive composite_body | complex may contain other fibers other than the heat-fusion fiber mentioned later.
The content of the other fibers is preferably 0 to 200% by mass with respect to 100% by mass of the nonionic crosslinked polymer. More preferably, it is 30-100 mass%.

In the absorbent composite, the content of the surface layer member is preferably 5 to 50% by mass with respect to 100% by mass of the nonionic crosslinked polymer. More preferably, it is 10-30 mass%.

The form of the absorbent composite of the present invention is not particularly limited, but for example, a planar shape such as a sheet shape or a flake shape; a rod shape (cylindrical or square column), a spherical shape, a pyramid shape such as a triangular pyramid or a quadrangular pyramid, Examples thereof include a three-dimensional shape such as a cone shape or a lump shape.
The “sheet” in the present invention means a shape having a planar spread generally recognized as a sheet, and the area of the widest surface of the shape is a, and the length in the direction perpendicular to the surface (the It is preferable that [a ^(1/2) ] / b is 5 or more when the thickness of the shape is b. In addition, when the thickness of the said shape is not constant, let the maximum value of thickness be b.
The absorbent composite of the present invention is preferably in the form of a sheet or a pyramid.

When the absorbent composite has a planar shape such as a sheet, the absorbent base material absorbs the liquid instantly because the area where the absorbent base material and the nonionic crosslinked polymer come into contact with the liquid to be absorbed is large. The nonionic cross-linked polymer strongly receives and holds the solution absorbed by the absorbent base material, so that the liquid absorption speed of the solution as a whole is further improved, and the solution can be sufficiently diffused throughout the sheet. it can.
Moreover, when the form of an absorptive complex is a sheet form, even after absorbing a liquid, the change in the thickness of the absorptive complex is small and can be suitably used for applications in which the thickness is regulated.

When the absorbent composite has a three-dimensional shape such as a conical shape or a pyramid shape, the nonionic crosslinked polymer is packaged with a sheet-like absorbent base material, or filled and sealed in a bag-shaped absorbent base material. It is preferable that it is a package. Such an absorbent composite easily secures a space for the nonionic crosslinked polymer to absorb and swell, and the amount of the nonionic crosslinked polymer is adjusted in consideration of swelling of the nonionic crosslinked polymer. By doing, it can suppress that an absorption base material fractures | ruptures by an internal pressure, and can further improve the liquid absorption amount per volume of an absorptive composite.
Since the volume of the nonionic crosslinked polymer after swelling depends on the swelling rate, the amount of the nonionic crosslinked polymer in the package depends on the type of the crosslinked polymer and the liquid to be absorbed, but the nonion before the liquid absorption. The volume of the cross-linked polymer is preferably 2 to 35% with respect to 100% of the volume secured after the non-ionic cross-linked polymer is swollen. More preferably, it is 3 to 20%.

In the case where the absorbent composite has a planar shape such as a sheet shape, the absorbent composite preferably has a thickness of 0.01 to 50 mm. More preferably, it is 0.01-30 mm, More preferably, it is 0.01-20 mm, Especially preferably, it is 0.05-10 mm, More preferably, it is 0.1-7 mm. Depending on the application of the absorbent composite, the thickness may be 0.1 to 5 mm.
The absorbent composite preferably has a mass per unit area of 0.1 to 3000 g / m ² . More preferably, it is 0.5-2500 g / m < ² >, More preferably, it is 1-1500 g / m < ² >, Especially preferably, it is 50-1500 g / m < ² >, Most preferably, it is 100-1500 g / m < ² >.
The absorbent composite preferably has a mass per unit area of the nonionic crosslinked polymer of 50 to 1500 g / m ² . Thereby, the liquid absorption capability of an absorptive complex improves more. More preferably 100 to 1000 g / ^{m 2,} more preferably from 150 to 800 g / ^{m 2.}

The absorbent complex preferably has a water absorption capacity of 3 to 30 g per 1 g of the absorbent complex. More preferably, it is 5g or more, More preferably, it is 8g or more. More preferably, it is 10 g or more, and particularly preferably 15 g or more.

The absorbent complex preferably has an ethanol absorption capacity of 3 to 30 g per 1 g of the absorbent complex. Thereby, the said absorptive complex can be used suitably for the absorber for ink, cosmetics, and a deodorizer. More preferably, it is 5g or more, More preferably, it is 8g or more. More preferably, it is 10 g or more, and particularly preferably 15 g or more.
The ability of the absorbent complex to absorb ethanol and water is a value calculated by “(absorbable complex mass + absorbed solution amount) / absorbent complex mass”. The liquid absorption capacity of the absorbent composite can be measured by the method described in the examples.
The ability of the crosslinked polymer to absorb ethanol and water is a value calculated by “(crosslinked polymer mass + absorbed solution amount) / crosslinked polymer mass”. The liquid absorption capacity of the crosslinked polymer can be measured by the method described in Examples.

The said absorptive complex may contain another component in the range which does not inhibit the performance of an absorptive complex. Although it does not restrict | limit especially as another component, For example, powders, such as a general water absorbing polymer, a zeolite, activated carbon, are mentioned.

<Absorption base material>
The said absorption base material contains a heat-fusion fiber and a surface layer member.
The heat-fusible fiber has a melting temperature of 70 to 200 ° C. The melting temperature is preferably 80 to 180 ° C, more preferably 90 to 150 ° C.
The heat-fusible fiber may be a single component fiber, but is preferably a composite fiber of two or more components. More preferably, it is a bicomponent composite fiber.
When the heat-fusible fiber is a composite fiber, the melting temperature of one fiber may be 70 to 200 ° C., and the melting temperature of the other fiber is preferably higher than the melting temperature of the one fiber. The composite form of the composite fiber is not particularly limited, and fibers of two or more components may be combined in parallel, but may have a structure in which a fiber having a high melting temperature is coated with a component having a low melting temperature. preferable.

Examples of fibers having a melting temperature of 70 to 200 ° C. include polyamides such as low melting point polyester copolymer, polyvinyl acetate, polystyrene, polyurethane elastomer, polyester elastomer, polypropylene, nylon (low melting point, melting point 200 ° C. or less), high Examples thereof include thermoplastic resins such as density polyethylene, low density polyethylene, linear low density polyethylene, polypropylene copolymer, and polyethylene copolymer.
The fibers having a melting temperature of 70 to 200 ° C. are preferably high density polyethylene, low density polyethylene, linear low density polyethylene, polyethylene copolymer, polypropylene, and low melting point polyester copolymer, more preferably high density. Polyethylene, low density polyethylene, linear low density polyethylene, and polyethylene copolymer.

The fiber having a high melting temperature when the heat-fusible fiber is a composite fiber is not particularly limited as long as the melting temperature is higher than that of a fiber having a melting temperature of 70 to 200 ° C., but the melting temperature is 5 than that of the fiber. It is preferable that it is higher by at least ° C. More preferably, it is 10 ° C or higher, more preferably 15 ° C or higher. Specific examples include polyamides such as polyester and nylon (high melting point, melting point greater than 200 ° C.). Polyester is preferable.

The fineness of the heat-sealing fiber is not particularly limited, but is preferably 0.5 to 10 denier. More preferably, it is 1-7 denier.
Although the length in particular of the said heat-fusion fiber is not restrict | limited, It is preferable that it is 1-50 mm. More preferably, it is 3 to 10 mm.

It is preferable that the said absorption base material contains fibers other than a heat-fusion fiber as a fiber which comprises an absorption core. As a result, the nonionic cross-linked polymer and the heat-bonded fiber are entangled with other fibers, and these are uniformly held in the absorbent core, and the number of fixing points due to the heat-bonding of the fibers is reduced. Can swell more fully when liquid is absorbed.
That is, the absorbing base material further includes other fibers other than the heat-sealing fibers, and the absorbent composite includes the nonionic crosslinked polymer, the heat-sealing fibers, and other fibers other than the heat-sealing fibers. A form in which the core is covered with the surface layer member is also one of preferred forms of the present invention.

The other fiber is not particularly limited as long as it has a melting temperature exceeding 200 ° C. or does not melt even at 70 ° C. or higher, but preferably contains a hydrophilic fiber.
The hydrophilic fiber means a fiber having an official moisture content of 3% or more.
The official moisture content of the fiber can be measured by the method described in JIS L 0105.
Since the hydrophilic fiber has high liquid diffusibility, the nonionic crosslinked polymer receives the liquid absorbed by the absorbent base faster, thereby improving the liquid absorption speed of the entire absorbent composite. It will be. Moreover, the fiber itself retains the liquid, so that the liquid absorption capacity of the absorbent composite as a whole is improved.

The hydrophilic fiber is preferably at least one selected from the group consisting of cellulosic fibers, polyamide fibers, animal fibers, and hydrophobic fibers having a hydrophilic surface.
Examples of the cellulosic fibers include natural fibers such as cotton and hemp; regenerated fibers such as rayon, cupra, lyocell, and polynosic; semisynthetic fibers such as acetate and triacetate; pulp and the like.
Examples of the polyamide fiber include nylon.
Examples of the animal fiber include wool and silk.
The hydrophobic fiber whose surface is hydrophilized is, for example, a fiber in which the surface of a hydrophobic fiber such as polyester or high melting point polyamide is coated with a hydrophilic polymer such as polyethylene glycol.
The hydrophilic fibers are more preferably cellulosic fibers, and more preferably pulp.

It is preferable that content of the said hydrophilic fiber is 0-100 mass% with respect to 100 mass% of nonionic crosslinked polymers. Thereby, the liquid absorption capability of an absorptive complex improves more. More preferably, it is 10-80 mass% as content of a hydrophilic fiber, More preferably, it is 20-70 mass%.

The other fibers preferably include a hydrophilic fiber and further a hydrophobic fiber. Thereby, it will be excellent by durability at the time of wetness.
Examples of the hydrophobic fiber include polyester, polyvinyl chloride, acrylic, and polyurethane. The hydrophobic fiber is preferably polyester.

It is preferable that content of the said hydrophobic fiber is 0-80 mass% with respect to 100 mass% of other fibers. More preferably, it is 10-50 mass%.

The surface layer member is a member that covers the absorbent core.
Although the said surface layer member is not restrict | limited especially as long as a liquid can osmose | permeate an absorption core, For example, it is preferable that thickness is 0.01-3 mm. More preferably, it is 0.1-1 mm.

Examples of the material for the surface layer member include paper, cloth, wood, elastomer, resin foam, and porous substrate.
The paper is a paper defined by JIS P 0001, and the cloth is a general term for a sheet-like fiber product defined by JIS L 0206.
Examples of the fabric include woven fabrics, knitted fabrics, braided fabrics, laces, nets, and nonwoven fabrics. Preferred are woven fabrics, knitted fabrics, and nonwoven fabrics, and more preferred are nonwoven fabrics.
The resin foam and the porous base are not particularly limited, and examples thereof include foamed polyurethane, foamed polystyrene, and an inorganic porous material.

Although it does not restrict | limit especially as a fiber raw material which comprises the said surface layer member, The above-mentioned hydrophilic fiber and hydrophobic fiber are mentioned. Preferred are hydrophilic fibers, and more preferred are cellulose fibers and amide fibers.

Although the shape of the said surface layer member will not be restrict | limited especially if it covers an absorption core, It is preferable that it is a sheet form or a bag form.
When the surface layer member is in the form of a sheet, the absorbent composite may have a structure in which one sheet-like surface layer member is laminated on the absorbent core, but the absorption core is sandwiched between the two sheet-like surface layer members. It is preferable that it is the structure made. Further, two or more such absorbent composites may be laminated.
Moreover, when a surface layer member is a bag shape, it becomes a structure where the bag-shaped surface layer member was filled with the absorption core.

<Nonionic cross-linked polymer>
The absorbent composite of the present invention contains a nonionic crosslinked polymer (hereinafter also simply referred to as a crosslinked polymer). Conventional cross-linked products mainly composed of polyacrylic acid (salt) are limited to water or solutions containing a large amount of water. For example, although an organic solvent can be absorbed as an aqueous solution containing excessive water, water evaporates. However, when the concentration of the organic solvent component is increased, there is a problem that the liquid that has been absorbed cannot be retained and the liquid oozes out.
On the other hand, the absorptive composite of the present invention can absorb a high-concentration organic solvent by including a nonionic crosslinked polymer. Nonionic cross-linked polymer has a lower liquid absorption speed than conventional polyacrylic acid (salt) -based cross-linked product, but it can be made into a composite with an absorbent base material. When the liquid is absorbed, the absorbing base material first absorbs the liquid, and the nonionic crosslinked polymer absorbs the diffused liquid. For this reason, by forming a composite, the absorbent composite of the present invention can absorb liquid faster than the case of using a nonionic crosslinked polymer alone. Further, since the crosslinked polymer is nonionic, it is excellent in safety and can be suitably used for cosmetics.

The nonionic crosslinked polymer is a crosslinked polymer having a structural unit (a) derived from the nonionic monomer (A).
The nonionic monomer (A) is not particularly limited as long as it is a nonionic monomer. For example, amide monomers; unsaturated alcohols; (poly) alkylene glycol monomers; (Meth) acrylic acid esters; aromatic vinyl monomers; alkenes; vinyl ethers; vinyl carboxylates; vinyl ethylene carbonate and derivatives thereof.
The nonionic crosslinked polymer preferably has a structural unit derived from an amide monomer and / or a (poly) alkylene glycol monomer.

The amide monomer is not particularly limited as long as it has an amide structure and an ethylenically unsaturated hydrocarbon group. For example, a monomer having a lactam structure (hereinafter referred to as a lactam monomer (N- (Meth) acrylamide, N-monomethyl (meth) acrylamide, N-monoethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-isopropylacrylamide, etc. Substituted or unsubstituted (meth) acrylamides; Vinylacetamides such as N-vinylacetamide and N-vinyl-N-methylacetamide; N-substituted and unsubstituted such as N-vinylformamide and N-vinyl-N-methylformamide Vinyl formamides; vinyl oxazolidone and the like.

The lactam monomer is not particularly limited as long as it is a monomer having a cyclic N-vinyl lactam structure, but the following formula (1);

(In formula, R < ¹ >, R < ² >, R < ³ >, R < ⁴ > is the same or different, and represents the C1-C10 alkyl group which may have a hydrogen atom or a substituent. X is 0- It represents an integer of 4. y represents an integer of 1 to 3).
The number of carbon atoms of the alkyl group in the above ^R 1 to R ^4, 1 to 6, and more preferably from 1 to 4. The alkyl group is more preferably a methyl group or an ethyl group, and particularly preferably a methyl group.
The substituent in the R ¹ to R ^4, although not particularly limited, ethylenically unsaturated hydrocarbon group; a carboxyl group, a sulfonic acid group and esters thereof and salts; amino group, a crosslinking agent such as a condensation reactable hydroxyl Reactive functional groups and the like.
If at least one of R ^{1 to} R ⁴ in the above formula (1) is a C 1-10 alkyl group having a reactive functional group capable of condensation reaction with the above-mentioned crosslinking agent as a substituent, it will be described later (2 ) And (3) can form a crosslinked structure.
R ^{1 to} R ³ are preferably hydrogen atoms. R ⁴ is preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom.
x is preferably an integer of 0 to 2, more preferably an integer of 0 to 1, and most preferably 0.
y is preferably 1 or 2, and more preferably 1.

Examples of the compound represented by the above formula (1) include N-vinylpyrrolidone, N-vinyl-5-methylpyrrolidone, N-vinylpiperidone, N-vinylcaprolactam, 1- (2-propenyl) -2-pyrrolidone and the like. 1 type, or 2 or more types can be used. As N-vinyl lactam, an unsaturated monomer having a pyrrolidone ring is preferable. More preferred is N-vinylpyrrolidone.

Examples of the unsaturated alcohols include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, 3- (meth) allyloxy-1,2-dihydroxypropane, (meth) allyl alcohol, and isoprenol.

The (poly) alkylene glycol monomer is not particularly limited as long as it has a (poly) alkylene glycol chain and an ethylenically unsaturated hydrocarbon group. For example, an alkylene is added to the hydroxyl group of the above-mentioned unsaturated alcohol. Examples thereof include alkylene oxide adducts obtained by adding oxides and esters of unsaturated carboxylic acids such as (meth) acrylic acid and (poly) alkylene glycol.
As the (poly) alkylene glycol monomer, the following formula (2);

(In Formula (2), R < ⁵ > -R < ⁷ > is the same or different and represents a hydrogen atom or a methyl group. R < ⁸ > O is the same or different and represents a C2-C18 oxyalkylene group. R ⁹ represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms, p represents a number of 0 to 5, q represents a number of 0 or 1. n represents an average addition mole of an oxyalkylene group. It is preferably a structure represented by a number of 1 to 300.

In the above formula (2), R ^{5 to} R ⁷ are the same or different and represent a hydrogen atom or a methyl group, but at least one of R ⁵ and R ⁶ is preferably a hydrogen atom.

The oxyalkylene group represented by — (R ⁸ O) — in the above formula (2) is an oxyalkylene group having 2 to 18 carbon atoms, and when two or more oxyalkylene groups are present, random addition, Any addition form such as block addition or alternate addition may be used.
The oxyalkylene group represented by the above-(R ⁸ O)-is preferably an oxyalkylene group having 2 to 8 carbon atoms, and more preferably an oxyalkylene group having 2 to 4 carbon atoms.
These oxyalkylene groups are alkylene oxide adducts, and examples of such alkylene oxides include ethylene oxide, propylene oxide, butylene oxide, isobutylene oxide, 1-butene oxide, 2-butene oxide, and styrene oxide. More preferred are ethylene oxide, propylene oxide and butylene oxide, and still more preferred are ethylene oxide and propylene oxide.

The formula in ^{(2) - (R 8 O} ) - oxyalkylene group represented by, if those containing oxyethylene group ethylene oxide added, 50 to 100 oxyethylene groups in the total oxyalkylene groups in 100 mol% It is preferable to contain mol%. By containing oxyethylene groups in such a ratio, it is possible to suppress the increase in air entrainment, to facilitate the adjustment of the air amount, and to suppress the decrease in strength and freeze-thaw resistance. it can. More preferably, it is 60-100 mol%, More preferably, it is 70-100 mol%, Especially preferably, it is 80-100 mol%, Most preferably, it is 90-100 mol%.

R ⁹ in the above formula (2) represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. R ⁹ is preferably a hydrocarbon group having 1 to 20 carbon atoms or a hydrogen atom. More preferably, it is a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, more preferably a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, particularly preferably a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms. And most preferably a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms.
Hydrocarbon groups include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, hexyl and heptyl groups. Octyl group, nonyl group, decyl group, undecyl group, dodecyl group, isooctyl group, 2,3,5-trimethylhexyl group, 4-ethyl-5-methyloctyl group and 2-ethylhexyl group, tetradecyl group, octadecyl group, Linear or branched alkyl group such as icosyl group; cyclic alkyl group such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl; phenyl group, benzyl group, phenethyl group, o-, m- or p -Tolyl group, 2,3- or 2,4-xylyl group, Shichiru group, a naphthyl group, anthryl group, phenanthryl group, a biphenylyl group, a benzhydryl group, and aryl groups such as trityl group and pyrenyl group. Among these, a linear, branched or cyclic alkyl group is preferable.

In the above formula (2), p represents a number of 0 to 5, and q represents a number of 0 or 1, but a preferred combination of p and q is a combination of p being 1 or 2 and q being 0, or p Is a combination of 0 and q = 1.

N in the said Formula (2) represents the average addition mole number of an oxyalkylene group, and is the number of 1-300. Preferably it is 1-150, More preferably, it is 1-100, More preferably, it is 1-80, Especially preferably, it is 1-50, Most preferably, it is 1-30.

The (meth) acrylic acid ester is not particularly limited as long as it is an ester of (meth) acrylic acid and an alcohol having 1 to 20 carbon atoms. For example, methyl (meth) acrylate, ethyl (meth) acrylate , (Butyl) (meth) acrylate, cyclohexyl (meth) acrylate, 2-hydroxyethyl acrylate and the like.

Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, vinyl toluene, indene, vinyl naphthalene, and phenylmaleimide.
Examples of the alkenes include ethylene, propylene, butadiene, isobutylene, octene and the like.
Examples of the vinyl ethers include methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, and the like.
Examples of the vinyl carboxylates include vinyl acetate and vinyl propionate.

Among the nonionic monomers (A), amide monomers and (poly) alkylene glycol monomers are preferable.
That is, the nonionic crosslinked polymer of the present invention preferably has a structural unit derived from an amide monomer and / or a (poly) alkylene glycol monomer. More preferably, it has a structural unit derived from an amide monomer.

The crosslinked structure of the nonionic crosslinked polymer can be formed by, for example, the following (1) to (5).
(1) Polymerizing a monomer component containing a crosslinkable monomer to produce a polymer having a crosslinked structure (2) Obtained by polymerizing a monomer component containing a monomer having a reactive functional group (3) A monomer 1 having a reactive functional group, and the monomer 1 are formed by reacting the obtained polymer with a crosslinking agent having a plurality of functional groups that react with the reactive functional group. After the monomer component containing both the reactive functional group-reactive monomer and the monomer 2 having a reactive functional group is polymerized, the reactivity of the reactive functional group of monomer 1 and the reactivity of monomer 2 (4) A radical is generated in the polymer, and a crosslinked structure is formed between the polymers in which the radical is generated (self-crosslinking). In the present invention, a radical is generated and a polymer in which the radical is generated reacts with a crosslinkable monomer to form a crosslinked structure. Cross-linked structure of the bridge polymers (1) to (5) may be those formed by any, is preferably one formed by the above (1).

The crosslinkable monomer in the above (1) and (5) is as described later.
When the crosslinked polymer of the present invention has a crosslinked structure formed by the above (2) or (3), the crosslinked polymer of the present invention is the above nonionic monomer or other monomer (E ) Derived from a monomer having a reactive functional group.
The reactive functional group in the above (2) and (3) is not particularly limited, and examples thereof include a carboxyl group, a sulfonic acid group, and esters and salts thereof; an amino group, a hydroxyl group, a mercapto group, an isocyanate group, an oxazoline group, and the like. It is done.
When the crosslinked structure is formed by the above (3), the combination of reactive functional groups having reactivity with each other includes a carboxyl group (and its ester or salt), a hydroxyl group, and a sulfonic acid group (and its ester). And salt) and hydroxyl group, carboxyl group (and its ester and salt) and amino group, carboxyl group (and its ester and salt) and oxazoline group, sulfonic acid group (and its ester and salt) and amino group, isocyanate group and hydroxyl group An isocyanate group and an amino group, an oxazoline group and a hydroxyl group, an oxazoline group and a mercapto group, and the like. When the cross-linked structure of the cross-linked polymer of the present invention is formed by the above (2), the reactive functional group possessed by the monomer and the functional group reacting with the reactive functional group possessed by the cross-linking agent The example of combination is the same as this.
The crosslinking agent in (2) is not particularly limited as long as it has a plurality of functional groups capable of reacting with the reactive functional group. For example, ethylenediamine, hexamethylenediamine, phenylenediamine, oxazoline group-containing polymer ( Nippon Shokubai Epocross), butanediol, tolylene diisocyanate, hexamethylene diisocyanate and the like.

In the case where the nonionic crosslinked polymer contained in the absorbent composite of the present invention has a crosslinked structure formed by the above (1) or (5), the crosslinking monomer is at least two polymerizable molecules per molecule. And a compound having at least two radically polymerizable ethylenically unsaturated hydrocarbon groups per molecule.
The compound having a lactam structure and at least two ethylenically unsaturated hydrocarbon groups is included in both the N-vinyl lactam monomer and the crosslinkable monomer.

Specific examples of the crosslinkable monomer include N, N′-alkylenebis (meth) acrylamide having an alkylene group having 1 to 4 carbon atoms such as N, N′-methylenebis (meth) acrylamide; (Poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate and other (poly) alkylene glycol di (meth) acrylates having a C 1-4 alkylene group; trimethylolpropane tri (meta ) Trimethylolpropane (di, optionally modified with alkylene oxide having 1 to 4 carbon atoms such as acrylate, trimethylolpropane di (meth) acrylate, ethylene oxide modified trimethylolpropane tri (meth) acrylate, etc. Tri) (meth) acrylate; grease Glycerin (di, tri) (meth) acrylates such as phosphorus tri (meth) acrylate and glycerin acrylate methacrylate; Pentaerythritol (di, tri, tetra) (meth) acrylates such as pentaerythritol tetra (meth) acrylate; Dipentaerythritol hexa ( Dipentaerythritol (di, tri, tetra, penta, hexa) (meth) acrylate such as (meth) acrylate; Pentaerythritol (di, tri, tetra) (meth) such as pentaerythritol tri (meth) allyl ether Allyl ether; triallyl cyanurate (triallyl cyanurate), triallyl isocyanurate, triallyl phosphate, triallylamine and other C9-20 triallyl compounds; diallyl carbonate, 1,3-bis (allyloxy) C6-C20 diallyl compounds such as 2-propanol; (Di, tri) vinyl ether, divinyl ketone, (di, tri) vinylbenzene, divinyltoluene, divinylxylene, etc. Tri) vinyl compounds; diisocyanates having 2 to 20 carbon atoms such as tolylene diisocyanate and hexamethylene diisocyanate; poly (meth) allyloxyalkane, N, N′-divinyl-2-imidazolidinone, N, N′-1, Examples include 4-butylenebis (N-divinylacetamide), (di, tri, tetra, penta, hexa, hepta, octa) allyl sucrose. These may use only 1 type and may use 2 or more types together.
Among the crosslinkable monomers, a compound having two or more allyl groups, since the remaining monomer and soluble component (which is a non-crosslinked polymer component and soluble in water) tend to decrease. Is preferably used. Specifically, triallyl cyanurate, triallyl isocyanurate, triallyl phosphate, triallylamine, diallyl carbonate, 1,3-bis (allyloxy) -2-propanol, pentaerythritol (di, tri, tetra) (meth) allyl Ether, (di, tri, tetra, penta, hexa, hepta, octa) allyl sucrose are preferred, triallyl cyanurate, pentaerythritol (di, tri, tetra) (meth) allyl ether, (di, tri, tetra, penta) , Hexa, hepta, octa) allyl sucrose is more preferred.

The (poly) alkylene glycol di (meth) acrylate preferably has 2 or more and 50 or less, more preferably 2 or more and 20 or less, and further preferably 2 or more and 10 or less oxyalkylene groups per molecule. It is preferable that an oxyethylene group is 50-100 mol% with respect to 100 mol% of oxyalkylene groups which the said (poly) alkylene glycol di (meth) acrylate has, and it is more preferable that it is 80-100 mol%.
One molecule of trimethylolpropane (di, tri) (meth) acrylate when the above trimethylolpropane (di, tri) (meth) acrylate is modified with an alkylene oxide having an alkylene group having 1 to 4 carbon atoms It is preferable that the average number of added alkylene oxides is the same.

The structural unit derived from the crosslinkable monomer is a structural unit having the same structure as a structural unit in which at least one of the polymerizable carbon-carbon double bond groups of the crosslinkable monomer is a single bond. is there. That is, if the crosslinkable monomer has the same structure as the structural unit in which at least one of the polymerizable carbon-carbon double bond groups is a single bond, for example, a monomer other than the crosslinkable monomer may be used. The structural unit formed by post-crosslinking after polymerization is also included in the structural unit derived from the crosslinkable monomer.

The nonionic crosslinked polymer may have a structural unit (e) derived from a monomer (E) other than the nonionic monomer (A) and the crosslinkable monomer. Further, as long as the nonionic crosslinked polymer becomes nonionic, it may have a structural unit derived from an ionic monomer as the other monomer (E). Examples of the other monomer (E) include (i) unsaturated monocarboxylic acids such as acrylic acid and methacrylic acid, and salts thereof; (ii) fumaric acid, maleic acid, methylene glutaric acid, itaconic acid, and the like. (Iii) 3-allyloxy-2-hydroxypropane sulfonic acid, (meth) allyl sulfonic acid, isoprene sulfonic acid, (Iv) N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth); unsaturated sulfonic acids such as ethyl (meth) acrylate-2-sulfonate and derivatives thereof; and salts thereof; Unsaturated amines such as acrylamide, vinyl pyridine, vinyl imidazole and their salts or their quaternized compounds; (v) maleic anhydride, Unsaturated anhydrides such as water itaconic acid and the like.
These may use only 1 type and may use 2 or more types together.
In addition, as a salt in said (i)-(iii), a metal salt, ammonium salt, an organic amine salt, etc. are illustrated. Examples of the salt in (iv) include hydrochloride, sulfate and the like.

In the nonionic crosslinked polymer, the proportion of the structural unit (a) derived from the nonionic monomer (A) is all structural units (the structural unit (a) derived from the nonionic monomer (A) and other single units). It is preferable that it is 50-100 mol% with respect to 100 mol% of the structural unit derived from a monomer (E). More preferably, it is 70-100 mol%, More preferably, it is 80-100 mol%, Especially preferably, it is 90-100 mol%, Most preferably, it is 100 mol%.

When the nonionic crosslinked polymer has a structural unit derived from an amide monomer and / or a (poly) alkylene glycol monomer, the amide monomer and / or (poly) alkylene glycol monomer The proportion of structural units derived from is preferably 50 to 100 mol% with respect to 100 mol% of all structural units. More preferably, it is 70-100 mol%, More preferably, it is 80-100 mol%, Especially preferably, it is 90-100 mol%, Most preferably, it is 100 mol%.

In the nonionic crosslinked polymer, the proportion of the structural unit (e) derived from the other monomer (E) is preferably 0 to 50 mol% with respect to 100 mol% of all structural units. More preferably, it is 0-30 mol%, More preferably, it is 0-20 mol%, Especially preferably, it is 0-10 mol%, Most preferably, it is 0 mol%.

The nonionic crosslinked polymer preferably has a structural unit derived from a crosslinkable monomer and / or a crosslinking agent in an amount of 0.01 to 2 mol% with respect to 100 mol% of all structural units, 0.01 to It is more preferably 1 mol%, more preferably 0.05 to 1 mol%, and most preferably 0.1 to 1 mol%.
By adjusting the use amount of the crosslinkable monomer and / or crosslinking agent, the ability of the nonionic crosslinked polymer of the present invention to absorb and retain a solution such as an ink can be adjusted. Moreover, if the structural unit derived from a crosslinkable monomer and / or a crosslinking agent is 0.01 mol% or more, crushing at the time of producing a nonionic crosslinked polymer becomes easy.

The average particle diameter of the nonionic crosslinked polymer of the present invention is not particularly limited, but is preferably 0.1 μm or more and 2000 μm or less. More preferably, they are 0.1 micrometer or more and 1000 micrometers or less, More preferably, they are 1 micrometer or more and 1000 micrometers or less, Most preferably, they are 10 micrometers or more and 1000 micrometers or less, Most preferably, they are 50 micrometers or more and 850 micrometers or less. When the average particle diameter is in the above preferred range, the water absorption capacity of the nonionic crosslinked polymer of the present invention tends to be improved, and the liquid absorption speed is also in a suitable range. If the average particle diameter is 0.1 μm or more, it is possible to sufficiently suppress the formation of lumps when water or the like is absorbed. Furthermore, when processing into a sheet-like absorption base material, the fall-off | omission of the powder from a sheet-like absorption base material can fully be suppressed. If the average particle diameter is 2000 μm or less, an increase in the thickness of the sheet due to wetting in the absorbent core can be sufficiently suppressed. Moreover, the nonionic crosslinked body absorbs liquid, and the speed at which the liquid can be firmly held as the entire absorbent complex increases. In addition, the nonionic crosslinked polymer preferably has an average particle size of 300 μm or less, and in this case, it is possible to sufficiently ensure voids in which the nonionic crosslinked body can swell in the absorbent composite.
Moreover, when manufacturing a bag-like absorptive composite, it is preferable that an average particle diameter is 100-500 micrometers, and if an average particle diameter is 100 micrometers or more, it will bridge | crosslink from the eyes of a bag-shaped absorption base material. The combined leakage can be suppressed, and if it is 500 μm or less, the liquid absorption rate tends to be further improved.
The average particle diameter of the nonionic crosslinked polymer can be measured by the method described in Examples.

<Method for producing nonionic crosslinked polymer>
Although the production of the nonionic crosslinked polymer is not particularly limited, it can be produced by polymerizing the monomer component, and specific examples and preferred examples of the monomer component are as described above. The content ratio of nonionic monomer, other monomer (E) and crosslinkable monomer to 100 mol% of all monomers (nonionic monomer and other monomer (E)) component Is the same as the proportion of the structural units derived from the nonionic monomer, the other monomer (E), and the crosslinkable monomer with respect to 100 mol% of all the structural units described above.

The polymerization may be performed in the absence of a solvent, or a solvent may be used. The polymerization may be performed by various conventionally known methods such as bulk polymerization, solution polymerization, suspension polymerization, reverse phase suspension polymerization, emulsion polymerization, reverse phase emulsion polymerization, precipitation polymerization, or cast polymerization. A thin film polymerization method, a spray polymerization method, or the like can be employed. The stirring method for carrying out the polymerization reaction is not particularly limited, but when a gel-like cross-linked polymer is produced, a double-arm kneader is used as a stirring device, and the double-arm kneader It is more preferable to stir while subdividing with a shearing force. The polymerization step can be performed batchwise or continuously.

In the above polymerization step, the method of starting the polymerization of the monomer component containing the nonionic monomer includes a method of adding a polymerization initiator, a method of irradiating UV, a method of applying heat, and in the presence of a photopolymerization initiator. For example, a method of irradiating light can be employed.

In the polymerization step, when a solvent is used, examples of the solvent include one or more selected from water, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butyl alcohol, diethylene glycol, and other alcohols. .

In performing the polymerization in the polymerization step, it is preferable to use a polymerization initiator. Examples of the polymerization initiator include peroxides such as hydrogen peroxide and t-butyl hydroperoxide; persulfates such as sodium persulfate, potassium persulfate, and ammonium persulfate; dimethyl 2,2′-azobis (2 -Methylpropionate), 2,2'-azobis (isobutyronitrile), 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis (2-methylpropionamidine) dihydrochloride Salt, 2,2′-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate, 2,2′-azobis [2- (2-imidazolin-2-yl) propane], 2 , 2′-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, 2,2′-azobis [2- (2-imidazolin-2-yl) propane] disulfate hydrate, , 2′-azobis (1-imino-1-pyrrolidino-2-methylpropane) dihydrochloride, 2,2′-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] n hydrate, Azo compounds such as 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) propionamide]; benzoyl peroxide, lauroyl peroxide, peracetic acid, di-t-butyl peroxide, cumene hydroper Organic peroxides such as oxides; redox that generates radicals by combining oxidizing agents and reducing agents, such as ascorbic acid and hydrogen peroxide, sodium sulfoxylate and t-butyl hydroperoxide, persulfate and metal salts A mold initiator or the like is preferred. Of these polymerization initiators, hydrogen peroxide, persulfate, and azo compounds are preferable, and azo compounds are most preferable. Among them, 2,2′-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, 2,2′-azobis [2- (2-imidazolin-2-yl) propane], 2,2 '-Azobis [2- (2-imidazolin-2-yl) propane] disulfate hydrate, 2,2'-azobis (2-methylpropionamidine) dihydrochloride, 2,2'-azobis (2-methyl) Butyronitrile) is more preferred. These polymerization initiators may be used alone or in the form of a mixture of two or more.

As the usage-amount of the said polymerization initiator, the usage-amount of a monomer (Total usage-amount of a nonionic monomer (A), the other monomer (E) mentioned above, and a crosslinkable monomer) 1 It is preferably 0.1 g or more and 10 g or less, more preferably 0.1 g or more and 7 g or less, and further preferably 0.1 g or more and 5 g or less with respect to mol.
By making the usage-amount of an initiator into such a ratio, the ratio of the unreacted monomer contained in the obtained crosslinked polymer can fully be reduced.

In the polymerization step, as a suitable dispersant when employing the reverse phase suspension polymerization method, specifically, for example, sorbitan fatty acid ester, sucrose fatty acid ester, glycerin fatty acid ester, polyglycerin fatty acid ester, ethyl cellulose, Examples thereof include cellulose esters such as cellulose acetate, cellulose ethers, and carboxyl group-containing polymers such as α-olefin-maleic anhydride copolymers. These dispersants may be used alone or in combination of two or more. In addition, the hydrophobic organic solvent provided when employing the reverse phase suspension polymerization method is not particularly limited.

In the polymerization step, the polymerization temperature is not particularly limited, but a relatively low temperature is preferable because the molecular weight of the crosslinked polymer is increased, and the polymerization rate is improved within the range of 20 ° C to 100 ° C. Therefore, it is more preferable. The reaction time may be appropriately set according to the reaction temperature, the type (property) and combination of the monomer component, the polymerization initiator, and the solvent, the amount used, etc. so that the polymerization reaction is completed. Good.

The material of the reaction vessel for performing the polymerization step is not particularly limited as long as the polymerization step can be performed, but it is preferable to use a reaction vessel made of a material such as stainless steel. Unreacted monomers (nonionic monomers, etc.) contained in the resulting cross-linked polymer by allowing the polymerization reaction to proceed sufficiently by carrying out the polymerization reaction using a reaction vessel made of a material that easily conducts heat. The content of can be reduced.
It is also preferable to use a reaction vessel made of a material such as polypropylene that does not elute iron. By using a reaction vessel made of these materials, the content of iron contained in the resulting crosslinked polymer can be reduced.

The nonionic crosslinked polymer may be produced by including an optional step in addition to the polymerization step. For example, a drying step, a pulverizing step, a classification step, a granulation step, a post-crosslinking step, and the like may be included.

The nonionic crosslinked polymer is preferably produced including a drying step.
In particular, when the nonionic crosslinked polymer is obtained by polymerization using a solvent and is in a gel form, that is, a gel-like crosslinked polymer containing a solvent, the gel-like crosslinked polymer is dried. It is preferable to provide a process. In the present invention, drying refers to a solid content raising operation, and the ratio of the solid content relative to the mass of the whole nonionic crosslinked polymer may be increased as compared with that before drying, preferably a crosslinked polymer. The solid content is increased to 95% by mass or more, more preferably 96% by mass or more with respect to 100% by mass as a whole. In addition, it is preferable that the upper limit of solid content is about 99 mass%. Drying may be performed at the same time as polymerization, and drying during polymerization and drying after polymerization may be used in combination, but more preferably, a drying step of drying using a drying apparatus after polymerization is provided. Here, the solid content of the crosslinked polymer is a value measured by the following method.
About 1 g of a crosslinked polymer is weighed (mass W2 (g)) in a weighing can (mass W1 (g)) having a bottom diameter of about 5 cm, and left to stand in a constant temperature dryer at 150 ° C. for 1 hour, followed by drying. Let The weight (W3 (g)) of the weighing can + the crosslinked polymer after drying is measured, and the solid content is obtained from the following formula.
Solid content (mass%) = ((W3 (g) −W1 (g)) / W2 (g)) × 100

The drying step is preferably performed in the range of 80 ° C. to 250 ° C. through 50% or more of the entire time of the drying step, more preferably through substantially all the drying steps. By being in the above range, various physical properties of the crosslinked polymer tend to be further improved.
The drying temperature is defined by the heat medium temperature, but if it cannot be defined by the heat medium temperature such as microwave, it is defined by the material temperature. The drying method is not particularly limited as long as the drying temperature is within the above range, and hot air drying, airless drying, reduced pressure drying, infrared drying, microwave drying and the like can be suitably used. Among these, it is more preferable to use hot air drying. The amount of drying air when hot air drying is used is preferably 0.01 to 10 m / sec, more preferably 0.1 to 5 m / sec. The range of the drying temperature is more preferably 110 ° C to 220 ° C, and further preferably 120 ° C to 200 ° C. The drying may be performed at a constant temperature or may be performed by changing the temperature. However, it is preferable that substantially all the drying steps are performed within the above temperature range.

The pulverization step is preferably performed using a pulverizer. When the production method of the present invention includes a drying step, pulverization may be performed before, during or after drying, but preferably after drying. The pulverizer is not particularly limited. For example, a roll pulverizer such as a roll mill, a hammer pulverizer such as a hammer mill, an impact pulverizer, a cutter mill, a turbo grinder, a ball mill, a pin mill, and a flash mill. A jet mill or the like is used. Among these, in order to control the particle size distribution, it is more preferable to use a roll mill, a hammer pulverizer, an impact pulverizer, a pin mill, or a jet mill. In order to control the particle size distribution, it is more preferable to pulverize continuously twice or more, and it is more preferable to pulverize continuously three times or more.
Moreover, when grind | pulverizing twice or more, each grinder may be the same or different. It is also possible to use different types of pulverizers in combination.
Further, when the nonionic crosslinked polymer is pulverized to an average particle size of 100 μm or less, it is preferable to use a jet mill.

For example, in order to control the nonionic crosslinked polymer of the present invention to a specific particle size distribution, a classification step and a granulation step may be provided. For the classification, a sieve with a specific opening may be used. The classifier used for classification with a sieve is not particularly limited. For example, a vibration sieve (unbalance weight drive type, resonance type, vibration motor type, electromagnetic type, circular vibration type, etc.), in-plane motion sieve (Horizontal motion type, horizontal circle-linear motion type, three-dimensional circular motion type, etc.), movable screen type screen, forced stirring screen, screen vibration screen, wind screen, sonic screen, etc. are used, preferably vibration screen An in-plane motion sieve is used.

When the nonionic crosslinked polymer has a crosslinked structure formed by the above (2) to (5), in the method for producing the crosslinked polymer, after performing a polymerization step of polymerizing monomer components. A post-crosslinking step for forming the crosslinked structure is performed.
Examples of the method of post-crosslinking in the post-crosslinking step (crosslinking after polymerization) include, for example, (i) a method of irradiating the polymer obtained in the polymerization step with UV, γ rays, and electron beams, and (ii) in the polymerization step. A method of adding a reaction accelerator such as a condensing agent to self-crosslink the obtained polymer, (iii) a method of applying heat to the polymer obtained in the polymerization step, and (iv) a method of obtaining in the polymerization step. A method of adding a radical generator to the obtained polymer and then applying heat to self-crosslink, (v) a radical-polymerizable cross-linking agent (cross-linkable monomer) and radical polymerization to the polymer obtained in the polymerization step. Examples of the method include heating and / or light irradiation after the initiator is contained.
In addition, as a polymer used for a post-crosslinking process, what was manufactured from the monomer component may be used and a commercially available polymer may be used.

When the nonionic crosslinked polymer of the present invention has the crosslinked structure formed by the above (2), the amount of the crosslinking agent used is the reactive functional group (reactive functional group that reacts with the crosslinking agent) of the polymer. Group) It is preferable that the functional group contained in the crosslinking agent is 30 to 100 mol% with respect to 100 mol%. More preferably, it is 50-100 mol%. By using a crosslinking agent at such a ratio, a sufficient crosslinked structure can be formed, and the amount of unreacted crosslinking agent remaining in the resulting crosslinked polymer can be reduced.

Examples of the reaction accelerator used in the method (ii) include acids such as sulfuric acid and phosphoric acid; bases such as sodium hydroxide and potassium hydroxide; condensing agents such as N, N′-dicyclohexylcarbodiimide and the like. More than seeds can be used.
As the radical generator used in the method (iv), the same polymerization initiator as that used in the polymerization step described above can be used. Among the polymerization initiators, hydrogen peroxide, t-butyl hydroperoxide, t-butyl peroxypivalate, octanoyl peroxide, succinic peroxide, t-hexylperoxy-2-ethylhexanoate, t- Peroxides such as butyl peroxy-2-ethylhexanoate, t-butyl peroxyisobutyrate, and t-butyl peroxymaleic acid are preferred.

When the nonionic crosslinked polymer of the present invention has the crosslinked structure formed by the above (5), the amount of the crosslinkable monomer used in the post-crosslinking is the polymer before the post-crosslinking step. It is preferable that it is 0.1-50 mass% with respect to 100 mass%. More preferably, it is 1-30 mass%. By using the crosslinkable monomer at such a ratio, it is possible to absorb the pigment when the pigment is contained in the ink by forming a sufficient crosslinked structure, and to obtain the crosslinked weight obtained. The amount of unreacted crosslinkable monomer remaining in the coalescence can also be reduced.

In the production of the nonionic crosslinked polymer, when an N-vinyl lactam monomer is used as the nonionic monomer, a step of adding an organic acid to the obtained nonionic crosslinked polymer after the polymerization reaction is included. Is preferred. By adding an organic acid to the obtained nonionic crosslinked polymer, the amount of the N-vinyl lactam monomer remaining in the crosslinked polymer can be reduced.
Although it does not restrict | limit especially as said organic acid, The organic compound which has acid groups, such as a carboxyl group, a sulfonic acid group, a phosphonic acid group, a sulfuric acid group, and a phosphoric acid group, is mentioned. Examples of such organic acids include malonic acid, oxalic acid, succinic acid, aspartic acid, citric acid, glutamic acid, fumaric acid, malic acid, maleic acid, phthalic acid, trimellitic acid, pyromellitic acid, propionic acid, Examples include heptanoic acid, octanoic acid, glycolic acid, salicylic acid, lactic acid, L-ascorbic acid, benzoic acid, methanesulfonic acid, benzenesulfonic acid, laurylbenzenesulfonic acid, p-toluenesulfonic acid, benzenephosphonic acid, and laurylsulfuric acid. .

Although the usage-amount of the said organic acid is not restrict | limited in particular, It is preferable that it is 0.01-5 mass% with respect to 100 mass% of N-vinyl lactam monomers prepared at the reaction process. When the amount of the organic acid used is in the above range, the amount of the organic acid (salt) can be reduced while reducing the amount of the N-vinyl lactam monomer remaining in the resulting crosslinked polymer. More preferably, it is 0.05-3 mass% as a usage-amount of an organic acid, More preferably, it is 0.1-1 mass%.
In addition, the said organic acid (salt) represents the salt of the said organic acid and organic acid, and the salt of an organic acid is a neutralized product of the base and organic acid which are mainly added in the neutralization process mentioned later.

The reaction time between the organic acid and the nonionic crosslinked polymer when the organic acid is added to the nonionic crosslinked polymer is not particularly limited, but is preferably 10 minutes to 3 hours. More preferably, it is 30 minutes to 2 hours.

The method for producing the nonionic crosslinked polymer preferably includes a step of aging the nonionic crosslinked polymer after the polymerization reaction. The temperature in the aging step is not particularly limited, but is preferably 70 to 150 ° C. When the aging temperature is within the above range, polymerization of the remaining monomer can be promoted. More preferably, it is 80-100 degreeC.
The aging time in the aging step is not particularly limited, but is preferably 10 minutes to 5 hours. More preferably, it is 30 minutes to 3 hours.
When the method for producing the nonionic crosslinked polymer includes a step of adding an organic acid, the aging step is preferably performed before the step of adding the organic acid.

The aging step is preferably performed while crushing the nonionic crosslinked polymer. When the step of adding the organic acid is included, the organic acid is sufficiently permeated into the crosslinked polymer by crushing, so that the amount of the N-vinyl lactam monomer remaining in the obtained polymer is reduced. It can be reduced more sufficiently. The above polymer can be crushed by a commonly used method, for example, a method of crushing using a screw extruder such as a kneader or meat chopper, a gel crusher such as a cutter mill, or the like.

The method for producing the nonionic crosslinked polymer is a case where an organic acid is added, and when the bag-like absorbent composite described later is produced as the absorbent composite of the present invention, It is preferable to include a neutralization step after the addition step. The neutralization method is not particularly limited, but it is preferable to add a base after reacting the organic acid with the polymer. The base is not particularly limited. For example, ammonia; aliphatic amines such as monoethanolamine, diethanolamine, and triethanolamine; aromatic amines such as aniline; alkali metal hydroxides such as sodium hydroxide and potassium hydroxide Etc. These may use only 1 type and may use 2 or more types together. Among these, ammonia, aliphatic amines, and alkali metal hydroxides are preferable, and ammonia, monoethanolamine, diethanolamine, sodium hydroxide, and potassium hydroxide are more preferable.

<Method for producing absorbent composite>
The method for producing the absorbent composite of the present invention is not particularly limited. For example, the production method described above includes a step of mixing a nonionic crosslinked polymer and a fiber containing a heat-fusible fiber to form an absorbent core and absorption. And a step of covering the core with a surface layer member.
In the step of forming the absorbent core, the method for mixing the nonionic crosslinked polymer and the fiber containing the heat-sealing fiber is not particularly limited, but dry mixing using a mixer is preferable.
In the step of forming the absorbent core, the nonwoven material is preferably formed using the mixture obtained by the mixing. As a result, the nonionic crosslinked polymer is dispersed in the absorption core. When the absorbent composite is in the form of a sheet, the non-woven material is a non-woven fabric and is preferably manufactured by papermaking the mixture. More preferably, it is made by air.

The step of covering the absorbent core with the surface layer member is not particularly limited, but the sheet-like surface layer member is overlaid on the absorbent core, or the absorbent core is sandwiched between two sheet-like surface layer members, or the bag-like surface layer member. It is preferable to heat-fuse the absorbent core and the surface layer member after filling the absorbent core.

The method for heat-sealing is not particularly limited, and examples thereof include a method using a hot plate such as a hot roll and a hot press, a method of blowing hot air, and the like.
The temperature of the heat fusion is not particularly limited as long as the heat fusion fiber is melted, but is preferably 90 to 180 ° C. More preferably, it is 100-130 degreeC.

<Uses of absorbent composite>
Since the absorbent composite of the present invention is excellent in the ability to absorb various liquids, it can be suitably used for cosmetics such as ink absorbents and moisturizing agents.
Moreover, the absorptive composite of this invention can also absorb the liquid and odor component containing a deodorizing component, and can be used suitably also for a deodorizing agent use.
The odor component capable of exerting the effect of the absorbent complex is not particularly limited, but thiols such as methyl mercaptan, amines such as ammonia, carboxylic acids such as acetic acid, aldehydes such as nonenal, diacetyl, etc. And diketones. That is, the absorptive complex of the present invention can exert a deodorizing effect on various odor components, and the reason is considered as follows. Since the absorptive complex of the present invention has a hygroscopic property, the water-soluble odor component is adsorbed through the absorbed water, or the crosslinked polymer of the present invention has a structural unit derived from an amide monomer. In this case, it is considered that an odor component is adsorbed at the N site or carbonyl group of the amide monomer. The absorptive complex of the present invention exhibits a more excellent deodorizing effect on carboxylic acids such as acetic acid among the odor components.

<Solution that absorbable complex can absorb>
Examples of the solution that can be absorbed by the absorbent composite of the present invention include water, water-soluble organic solvents, inks, and liquid cosmetic compositions.
Examples of the water-soluble organic solvent include glycerin, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,2-butanediol, 1,2-pentanediol, 1,2 -Hexanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol mono-n-propyl ether, ethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, ethylene glycol mono-n- Butyl ether, ethylene glycol mono-t-butyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monobutyl ether, diethylene glycol -T-butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-t-butyl ether, propylene glycol mono-n-propyl ether, propylene glycol monoisopropyl ether, propylene glycol mono-n-butyl ether, dipropylene glycol Mono-n-butyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol monoisopropyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol ethyl methyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether Ter, tetraethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, tripropylene glycol dimethyl ether, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, 2-butanol, tert-butanol, isobutanol, Alcohols or glycols such as n-pentanol, 2-pentanol, 3-pentanol, and tert-pentanol; Amide solvents (amides) such as N, N-dimethylformamide and N, N-dimethylacetamide Pyrrolidones such as 2-pyrrolidone and N-methyl-2-pyrrolidone; 2-oxazolidone; 1,3-dimethyl-2-imidazolidinone; 1,1,3,3-tetramethylurine Dimethyl sulfoxide; and sulfolane.
Preferred water-soluble organic solvents are glycerin, glycols, alcohols, amides, and pyrrolidones.

The component contained in the ink is not particularly limited, and examples thereof include water, the water-soluble organic solvent, a dye, a pigment, and other additives.
Examples of the dye include black azo compounds, copper phthalocyanine compounds, and magenta dyes.
Examples of the pigment include inorganic pigments such as carbon black and metal oxides, and organic pigments such as azo pigments and phthalocyanine pigments. The particle diameter of the pigment is not particularly limited, but is preferably 0.01 to 0.50 μm, and more preferably 0.02 to 0.20 μm.

Examples of the liquid cosmetic composition include basic cosmetics such as lotion, milky lotion, and beauty serum; makeup cosmetics such as liquid foundation and base emulsion; cleansing cosmetics such as liquid cleansing agents; sunscreen cosmetics And other cosmetics (including quasi-drugs); skin external preparations such as liniments and lotions.
The components contained in the liquid cosmetic composition are not particularly limited. For example, an oily base, a moisturizer / feel improver, a surfactant, a polymer, a thickener / gelator, a solvent / propellant, an oxidizer Inhibitors, reducing agents, oxidizing agents, preservatives / antibacterial agents, chelating agents, pH adjusters / acids / alkalis, powders, inorganic salts, UV absorbers, whitening agents, vitamins and their derivatives, anti-inflammatory agents, Anti-inflammatory agents, hair-growth agents / blood circulation promoters / stimulants, hormones, anti-wrinkle agents / anti-aging agents / squeeze agents / cooling agents / warm agents, wound healing promoters / stimulation mitigants / painkillers / cells Activators, plant / animal / microbe extracts, antipruritics, exfoliating / dissolving agents, antiperspirants, refreshing agents, astringents, enzymes, nucleic acids, fragrances, pigments / colorants / dyes / pigments, water, etc. Can be mentioned.
Specific examples of these components are the same as those described in JP-A-2007-45776.

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. Unless otherwise specified, “part” means “part by mass” and “%” means “% by mass”.

<Measurement of average particle size of nonionic crosslinked polymer>
The cumulative 50% value measured by a dry type particle size distribution measuring apparatus (Spectris Co., Ltd., Malvern Division, Model: Mastersizer 3000 dry type) was defined as the average particle size. The measurement conditions are shown below.
<Measurement conditions>
Dry laser diffraction scattering dispersion pressure: 1 bar
Particle refractive index: 1.52
Particle absorption rate: 0.01
Particle shape: Non-spherical Solvent name: Air (AIR)
Measurement range: 0.1-3500 μm

<Evaluation of Nonionic Crosslinked Polymer Solvent (including Deionized Water) and Solution Absorption Capability>
About 0.1 g of the crosslinked polymer was accurately weighed (mass W5 (g)), placed in a 4 cm × 5 cm non-woven tea bag, and sealed by heat sealing. The above operation was performed in a room at a temperature of 23 ± 2 ° C., a relative humidity of 50 ± 5%, and a normal pressure. This tea bag is placed in a screw tube made of glass and having a specified capacity of 50 mL, and is placed in a solvent or solution (conductivity 10 μS / cm or less in the case of deionized water) at room temperature (temperature 23 ± 2 ° C.) at normal pressure. Soaked for hours. In addition, in the case of oil etc. with a slow liquid absorption speed, after being immersed at 40 degreeC for 24 hours, it stood to cool for 10 minutes. Next, the end of the tea bag was grasped with tweezers, the tea bag was pulled up, placed on a Kim towel (manufactured by Nippon Paper Crecia Co., Ltd.) with one side of the tea bag down, and allowed to stand for 5 seconds. Next, the liquid was drained by placing it on the Kim towel with the opposite side down and leaving it to stand for 5 seconds, and then the mass (W6 (g)) of the tea bag was measured. Separately, the same operation was performed without using a crosslinked polymer, and the mass (W4 (g)) of the tea bag at that time was determined as a blank. The liquid absorption capacity calculated according to the following formula was defined as the liquid absorption capacity.
Liquid absorption ratio (g / g) = (W6 (g) -W4 (g)) / W5 (g)

<Production Example 1>
130.0 parts of N-vinylpyrrolidone (manufactured by Nippon Shokubai Co., Ltd., hereinafter also referred to as VP), 0.52 part of triallyl cyanurate (hereinafter also referred to as CTA) as a crosslinking agent (0.18 mol% relative to VP), 304.6 parts of deionized water was charged into a desktop kneader (PNV-1H type, manufactured by Chuo Rika Co., Ltd.). Subsequently, nitrogen substitution was performed at 100 ml / min for 30 minutes. Next, nitrogen was introduced at 30 ml / min, and the temperature was raised to 56 ° C. After stabilizing the liquid temperature to 56 ° C., 15 mass of 2,2′-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride (hereinafter also referred to as “VA-044”) as an initiator. Polymerization was started by adding 1.96 parts of a% aqueous solution (0.25 g based on 1 mol of the total amount of VP and CTA used). After the polymerization reaction progressed and a gel was formed, aging was performed at 90 ° C. for 60 minutes while crushing the gel by rotating a kneader blade to complete the polymerization. Next, 65.0 parts of a 1% by weight aqueous solution of malonic acid was added over 3 minutes, and the mixture was stirred at 90 ° C. for 60 minutes. Further, 32.5 parts of a 2% by weight aqueous solution of diethanolamine was added over 3 minutes and stirred for 30 minutes. Next, the obtained gel was dried at 120 ° C. for 2 hours (manufactured by Yamato Kagaku Precision Incubator Model DF42, maximum aperture, external size 232 × 297 × 50H (mm) using 2 stainless steel bats), A combined dry product was obtained. Subsequently, the obtained crosslinked polymer was pulverized with a pulverizer, classified using a JIS standard sieve having an opening of 500 μm, and the powder that passed through the 500 μm sieve was used as a particulate VP crosslinked polymer (1). . It was 288 micrometers when the average particle diameter of the obtained VP crosslinked polymer (1) was measured by said method.

<Production Example 2>
10.0 parts of VP (1000.0 parts), pentaerythritol triallyl ether (trade name: Neoallyl P-30M, made with diethanolamine at pH 6 or higher) as a crosslinkable monomer (0 with respect to VP) .65 mol%), 2368.33 parts of deionized water, and a desktop kneader (PNV-5H type, manufactured by Chuo Rika Co., Ltd.). Subsequently, nitrogen substitution was performed at 400 ml / min for 40 minutes. Next, nitrogen was introduced at 30 ml / min, and the temperature was raised to 56 ° C. After the liquid temperature was stabilized at 56 ° C., 47.37 was added as a 15 mass% aqueous solution of 2,2′-azobis (2-methylpropionamidine) dihydrochloride (hereinafter also referred to as “V-50”) as an initiator. Part (0.78 g with respect to 1 mol of the total amount of VP and pentaerythritol triallyl ether used) was added to initiate polymerization. After the polymerization reaction progressed and a gel was formed, aging was performed at 90 ° C. for 60 minutes while crushing the gel by rotating a kneader blade to complete the polymerization. Next, 500.0 parts of a 1.4% by weight aqueous solution of malonic acid was added over 3 minutes, and the mixture was stirred at 90 ° C. for 60 minutes. Further, 250.0 parts of a 2.8% by mass aqueous solution of diethanolamine was added over 3 minutes and stirred for 30 minutes. Next, the obtained gel was dried at 120 ° C. for 3 hours (manufactured by Yamato Kagaku precision thermostat Model DF42 with maximum aperture, outer size 232 × 297 × 50H (mm), two stainless bats, outer size 206 × 267 × 40H (mm ) Using 8 stainless bats), a dried VP crosslinked polymer was obtained. Subsequently, the obtained crosslinked polymer is pulverized by a pulverizer, classified using a JIS standard sieve having openings of 250 μm and 500 μm, and the powder remaining on the 250 μm sieve through VP crosslinking is passed through the 500 μm sieve. The polymer (2) was obtained. It was 393 micrometers when the average particle diameter of the obtained VP crosslinked polymer (2) was measured by said method.

<Production Example 3>
Acrylic containing 27 g of methoxypolyethylene glycol acrylate (NK Nakamura Chemical Industries, Ltd. NK ester AM-90G, EO addition mole number 9 mol, hereinafter also referred to as “AM-90G”), and 0.2% by mass of ethylene glycol diacrylate as impurities 3 g of 2-hydroxyethyl acid (manufactured by Nippon Shokubai) (hereinafter also referred to as HEA) and 70 g of pure water were charged into a 250 ml PP container. Next, stirring was started with a magnetic stirrer, and nitrogen substitution was performed at 100 ml / min for 30 minutes. Subsequently, it heated up to 40 degreeC, continuing stirring. After stabilizing the liquid temperature at 40 ° C., 0.1 g of a 20 mass% aqueous solution of V-50 was added as an initiator to initiate polymerization. After the polymerization reaction progressed and a gel was formed, aging was performed at 90 ° C. for 30 minutes to complete the polymerization. The obtained gel was crushed with a table kneader (PNV-1H type, manufactured by Chuo Rika Co., Ltd.) and dried at 120 ° C. for 2 hours (precision incubator made by Yamato Kagaku, model DF42, maximum aperture, external size 206 × 267 × 40H (mm) ) Using a single stainless bat) to obtain a PEG acrylate / HEA cross-linked polymer (ethylene oxide cross-linked polymer (3)).

<Example 1>
The following sheet-like absorbent composite was prepared using the VP cross-linked polymer (1) obtained in Production Example 1 as Example 1.
7.2 g of VP cross-linked polymer (1), 1.4 g of polyester heat-sealing fiber (surface polyethylene) and 5.7 g of polyester fiber were dry-mixed using a mixer. Subsequently, the obtained mixture is air-made on a wire screen formed to 400 mesh (mesh size 38 μm) using a batch type air-making device, thereby a web (sheet-like shape) having a size of 120 mm × 400 mm. Fiber, absorbent core). Further, the web was sandwiched between two non-woven fabrics made of rayon and pressed at 130 ° C. for 5 seconds to obtain a basis weight of about 330 g / m ² , a VP crosslinked polymer (1) content of 150 g / m ² , and VP crosslinked. A sheet (absorbent composite (1) of the present invention) having a polymer / absorbing substrate mass ratio of 0.8 and a thickness of 1.8 mm was obtained.
The following evaluation was performed with respect to the obtained absorptive complex (1). The results are shown in Table 1.

(Evaluation method of absorbent capacity of solvent and solution of absorbent composite)
The sheet-like absorbent composite was cut into 50 mm × 50 mm in a room at a temperature of 23 ± 2 ° C., a relative humidity of 50 ± 5% and a normal pressure, and the mass (W7 (g)) was measured accurately. This absorbent composite was placed in a polypropylene container and immersed in a solution (conductivity of 10 μS / cm or less in the case of deionized water) at room temperature (temperature 23 ± 2 ° C.) and normal pressure for 24 hours. Next, the end of the absorbent composite was grasped with tweezers and pulled up, placed on a Kim towel (manufactured by Nippon Paper Crecia Co., Ltd.) with one side of the absorbent composite down, and allowed to stand for 5 seconds. Next, after removing the liquid by placing it on the Kim towel with the opposite side down and leaving it to stand for 5 seconds, the mass (W8 (g)) of the absorbent composite was measured. The liquid absorption capacity calculated according to the following equation was defined as the liquid absorption capacity of various solutions.
Liquid absorption ratio (g / g) = W8 (g) / W7 (g)
In addition, when the surface layer member and the absorbent core are completely peeled off and / or when the nonionic cross-linked polymer is dropped from the absorbent composite by 50% (mass) or more, the liquid absorption capacity cannot be measured, and the liquid absorption ratio is 1. It was.

(Durability evaluation method when wet)
The sheet-like absorbent composite was cut into 50 mm × 50 mm in a room with a temperature of 23 ± 2 ° C., a relative humidity of 50 ± 5% and a normal pressure. Durability of the absorbent composite after placing the absorbent composite in a polypropylene container and immersing it in deionized water (conductivity of 10 μS / cm or less) at room temperature (temperature 23 ± 2 ° C.) and normal pressure for 24 hours. Sex was evaluated. When the surface layer member and the absorbent core are completely peeled off and / or when the nonionic cross-linked polymer is removed from the absorbent composite by 50% (mass) or more, x, the surface layer member is not completely peeled off from the absorbent core, but peeled off Is 20% (area) or more and / or when nonionic cross-linking polymerization is 20% (mass) or more and less than 50% (mass) is removed from the absorbent composite, Δ, otherwise.

<Example 2>
The following sheet-like absorbent composite was prepared using the VP crosslinked polymer (2) obtained in Production Example 2 as Example 2.
7.2 g of VP cross-linked polymer (2), 1.4 g of polyester heat-sealing fiber (surface layer polyethylene) and 6.5 g of pulp fiber were dry mixed using a mixer. Subsequently, the obtained mixture is air-made on a wire screen formed to 400 mesh (mesh size 38 μm) using a batch type air-making device, thereby a web (sheet-like shape) having a size of 120 mm × 400 mm. Fiber, absorbent core). Further, the web was sandwiched between two non-woven fabrics made of rayon and pressed at 130 ° C. for 5 seconds to obtain a basis weight of about 350 g / m ² and a VP crosslinked polymer (2) content of 150 g / m ² . A sheet (absorbent composite (2) of the present invention) having a polymer / absorbing substrate mass ratio of 0.8 and a thickness of 1.8 mm was obtained.

<Example 3>
The following sheet-like absorbent composite was prepared using the ethylene oxide-based crosslinked polymer (3) obtained in Production Example 3 as Example 3.
7.2 g of ethylene oxide-based crosslinked polymer (3), 1.4 g of polyester heat-sealing fiber (surface polyethylene) and 6.5 g of pulp fiber were dry-mixed using a mixer. Subsequently, the obtained mixture is air-made on a wire screen formed to 400 mesh (mesh size 38 μm) using a batch type air-making device, thereby a web (sheet-like shape) having a size of 120 mm × 400 mm. Fiber, absorbent core). Further, the web was sandwiched between two non-woven fabrics made of rayon and pressed at 130 ° C. for 5 seconds, whereby the basis weight was about 350 g / m ² , and the content of the ethylene oxide-based crosslinked polymer (3) was 150 g / m ² , A sheet having a mass ratio of ethylene oxide-based crosslinked polymer / absorbing substrate of 0.8 and a thickness of 1.8 mm (absorbent composite (3) of the present invention) was obtained.

<Example 4>
The following sheet-like absorbent composite was prepared using the VP crosslinked polymer (1) obtained in Production Example 1 as Example 4.
7.2 g of VP cross-linked polymer (1), 1.0 g of polyester heat-sealing fiber (surface layer polyethylene) and 3.8 g of polyester fiber were dry-mixed using a mixer. Subsequently, the obtained mixture is air-made on a wire screen formed to 400 mesh (mesh size 38 μm) using a batch type air-making device, thereby a web (sheet-like shape) having a size of 120 mm × 400 mm. Fiber, absorbent core). Furthermore, the surface layer of this web is sprinkled with polyethylene powder, sandwiched between two layers of non-woven fabric made of rayon (2.7 g for 2 sheets), and pressed at 130 ° C. for 5 seconds, the basis weight is about 330 g / m ² , Sheet having a VP cross-linked polymer (1) content of 150 g / m ² , a VP cross-linked polymer / absorbing substrate mass ratio of 1.0 and a thickness of 1.8 mm (absorbent composite (4) of the present invention) )
The obtained absorbent composite (4) was evaluated as in Example 1. The results are shown in Table 1.

<Example 5>
The following sheet-like absorbent composite was prepared using the VP crosslinked polymer (2) obtained in Production Example 2 as Example 5.
14.4 g of VP cross-linked polymer (2), 2.4 g of polyester heat-sealing fiber (surface layer polyethylene), 4.8 g of polyester fiber, and 4.8 g of pulp fiber were dry-mixed using a mixer. Subsequently, the obtained mixture is air-made on a wire screen formed to 400 mesh (mesh size 38 μm) using a batch type air-making device, thereby a web (sheet-like shape) having a size of 120 mm × 400 mm. Fiber, absorbent core). Furthermore, the surface layer of this web is sprinkled with polyethylene powder, sandwiched between two layers of non-woven fabric made of rayon (2.7 g for 2 sheets), and pressed at 130 ° C. for 5 seconds, the basis weight is about 630 g / m ² , Sheet with content of VP cross-linked polymer (2) of 300 g / m ² , mass ratio of VP cross-linked polymer / absorbing substrate of 1.0 and thickness of 5.2 mm (absorbent composite (5) of the present invention) )
The obtained absorbent composite (5) was evaluated as in Example 1. The results are shown in Table 1.

<Example 6>
The following sheet-like absorbent composite was prepared using the VP crosslinked polymer (2) obtained in Production Example 2 as Example 6.
21.6 g of VP cross-linked polymer (2), 3.8 g of polyester heat-sealing fiber (surface layer polyethylene), 7.7 g of polyester fiber, and 7.7 g of pulp fiber were dry-mixed using a mixer. Subsequently, the obtained mixture is air-made on a wire screen formed to 400 mesh (mesh size 38 μm) using a batch type air-making device, thereby a web (sheet-like shape) having a size of 120 mm × 400 mm. Fiber, absorbent core). Furthermore, the surface layer of this web is sprinkled with polyethylene powder, sandwiched between two layers of non-woven fabric made of rayon (2.7 g for two sheets), and pressed at 130 ° C. for 5 seconds, the basis weight is about 930 g / m ² , Sheet having a VP cross-linked polymer (2) content of 450 g / m ² , a VP cross-linked polymer / absorbing base material mass ratio of 1.0 and a thickness of 7.0 mm (absorbent composite (6) of the present invention) )
The obtained absorbent composite (6) was evaluated as in Example 1. The results are shown in Table 1.

<Comparative Example 1>
As Comparative Example 1, the following sheet-like absorbent composite was prepared using the VP crosslinked polymer (2) obtained in Production Example 2.
Two pieces of pulp / polypropylene nonwoven fabric (TRUSCO nonwoven fabric roll waste, material pulp / polypropylene) were cut into a size of 100 mm × 50 mm. 0.55 g of VP cross-linked polymer (2) was uniformly dispersed on one non-woven fabric (non-woven fabric A). After water is sprayed from above the sprayed VP crosslinked polymer (2), the other nonwoven fabric (nonwoven fabric B) is overlaid on the nonwoven fabric A sprayed with the VP crosslinked polymer (2), and 5 ° C. at 150 ° C. By press-bonding for 2 seconds, the VP cross-linked polymer (2) content is about 100 g / m ² , the VP cross-linked polymer / absorbing substrate mass ratio is 0.8, and the sheet-like absorbency is 1.0 mm. A complex (7) was obtained.
Evaluation similar to Example 1 was performed with respect to the obtained absorptive complex (7). The results are shown in Table 1.

<Comparative example 2>
As Comparative Example 2, the following sheet-like absorbent composite was prepared using the VP crosslinked polymer (2) obtained in Production Example 2.
Two pieces of pulp / polypropylene nonwoven fabric (TRUSCO nonwoven fabric roll waste, material pulp / polypropylene) were cut into a size of 100 mm × 50 mm. A VP cross-linked polymer gel swollen with water (a gel obtained by adding 2.7 g of ion-exchanged water to 0.3 g of VP cross-linked polymer (2)) was uniformly applied onto one non-woven fabric (non-woven fabric A). Similarly, the other nonwoven fabric (nonwoven fabric B) was coated with VP crosslinked polymer gel swollen with water. Next, the gel surfaces of the non-woven fabric A and the non-woven fabric B were overlapped and pressure-bonded. Then, by drying for 60 minutes at 150 ° C. using a dryer, the content of the VP crosslinked polymer (2) is 110 g / m ² , the mass ratio of the VP crosslinked polymer / absorbing substrate is 0.9, and the thickness A sheet-like absorbent composite (8) having a thickness of 1.0 mm was obtained.
Evaluation similar to Example 1 was performed with respect to the obtained absorptive complex (8). The results are shown in Table 1.

<Comparative Example 3>
As Comparative Example 3, the following sheet-like absorbent composite was prepared using the VP crosslinked polymer (1) obtained in Production Example 1.
Two pieces of pulp / polypropylene nonwoven fabric (TRUSCO nonwoven fabric roll waste, material pulp / polypropylene) were cut into a size of 100 mm × 50 mm. 0.6 g of VP cross-linked polymer (1) and 0.6 g of hot melt particles were uniformly dispersed on one nonwoven fabric (nonwoven fabric A). The other non-woven fabric (non-woven fabric B) is superimposed on the non-woven fabric A on which the VP cross-linked polymer (1) and the hot-melt particles are dispersed, and press-bonded at 150 ° C. for 5 seconds to obtain a VP cross-linked polymer (1). The sheet-like absorptive complex (9) whose content is about 120 g / m ² , VP cross-linked polymer / absorbing base material mass ratio is 1.0, and thickness is 1.0 mm was obtained.
Evaluation similar to Example 1 was performed with respect to the obtained absorptive complex (9). The results are shown in Table 1.

<Comparative example 4>
As Comparative Example 4, the following sheet-like absorbent composite was prepared using the VP crosslinked polymer (1) obtained in Production Example 1.
7.2 g of VP cross-linked polymer (1) and 5.5 g of polyester fiber were dry mixed using a mixer. Subsequently, the obtained mixture is air-made on a wire screen formed to 400 mesh (mesh size 38 μm) using a batch type air-making device, thereby a web (sheet-like shape) having a size of 120 mm × 400 mm. Fiber, absorbent core). Further, this web was sandwiched between two non-woven fabrics made of rayon and pressed at 130 ° C. for 5 seconds to obtain a basis weight of about 300 g / m ² , a VP crosslinked polymer (1) content of 150 g / m ² and a VP crosslinked. A sheet-like absorbent composite (10) having a polymer / absorbing substrate mass ratio of 1.0 and a thickness of 3.0 mm was obtained.
Evaluation similar to Example 1 was performed with respect to the obtained absorptive complex (10). The results are shown in Table 1.

From the above results, it can be seen that the sheet-like absorbent composite of the present invention is excellent in the ability to absorb various solutions and durability when wet.

<Example 4>
The liquid absorption capacity of deionized water, ethanol, and linoleic acid of the crosslinked polymers obtained in Production Examples 1 to 3 was measured by the above method. The results are shown in Table 2.

Claims (6)

An absorbent composite comprising a nonionic crosslinked polymer and an absorbent base material,
The absorbent base material includes a surface layer member and a heat-sealing fiber,
The heat-fusible fiber has a melting temperature of 70 to 200 ° C.,
The absorbent composite is characterized in that an absorbent core containing the nonionic crosslinked polymer and heat-bonded fibers is covered with a surface layer member. The absorbent substrate further includes other fibers other than the heat-sealing fibers,
2. The absorbent core according to claim 1, wherein an absorbent core including a nonionic crosslinked polymer, a heat-fusible fiber, and other fibers other than the heat-fusible fiber is covered with a surface layer member. Absorbable complex. The absorbent composite according to claim 1 or 2, wherein the nonionic crosslinked polymer has a structural unit derived from an amide monomer and / or a (poly) alkylene glycol monomer. body. The said other fiber contains a hydrophilic fiber, The absorptive composite_body | complex of Claim 2 or 3 characterized by the above-mentioned. The absorption according to claim 4, wherein the hydrophilic fiber is at least one selected from the group consisting of a cellulose fiber, a polyamide fiber, an animal fiber, and a hydrophobic fiber having a hydrophilic surface layer. Sex complex. The said surface layer member is a sheet form or a bag shape, The absorptive composite body in any one of Claims 1-5 characterized by the above-mentioned.