JP5721976B2 - Absorbent resin particles and method for producing the same - Google Patents

Description

  The present invention relates to absorbent resin particles, a production method thereof, an absorbent body including the same, and an absorbent article.

  Absorbent resin particles are resins that can absorb water several tens to several thousand times their own weight. For example, polyacrylic acid-based absorbent resins are known. These absorbent resins are widely used in disposable sanitary goods because of their high water absorption. However, it has been pointed out that conventional absorbent resin particles have a problem in terms of environmental load in the treatment method of sanitary products containing the resin particles, and the method of treatment in an incinerator causes global warming. . Under such circumstances, from the viewpoint of carbon neutral and the like, there is a strong demand for absorbent resin particles using plant-derived materials.

  As an absorptive resin using a plant-derived raw material, for example, a carboxymethylcellulose crosslinked body (Patent Documents 1 and 2), an alginate crosslinked body, a starch crosslinked body (Patent Document 3), a polyamino acid crosslinked body (Patent Documents 4 to 8), Galactomannan-metal ion crosslinked bodies (Patent Documents 9 to 11) and the like are known.

US Pat. No. 4,650,716 JP 2004-010634 A Japanese Patent Laid-Open No. 55-15634 JP 7-224163 A JP 7-309943 A JP-A-8-59820 JP-A-8-504219 JP-A-9-169840 JP-A-8-59891 Japanese Patent Publication No. 3-66321 JP 56-97450 A

  However, when the absorbent resin using these plant-derived raw materials is compared with the polyacrylic acid-based absorbent resin, the absorbent resin using the plant-derived raw materials has lower productivity and lower absorption performance. Has not yet been put to practical use.

  An object of the present invention is to provide absorbent resin particles containing a plant-derived raw material and having excellent absorption performance, and a method for producing the same.

The method for producing absorbent resin particles of the present invention comprises a monomer having an essential constituent monomer (a) comprising a water-soluble vinyl monomer (a1) and / or a hydrolyzable vinyl monomer (a2) and a crosslinking agent (a3). (1) After obtaining a crosslinked polymer (A) by copolymerizing (A) and the following cellulose solution (E) to obtain a crosslinked polymer / cellulose composite gel (A / B) Alternatively, a water-soluble vinyl monomer (a1) and / or a hydrolyzable vinyl monomer (a2) and a monomer having the crosslinking agent (a3) as an essential constituent monomer (a) and the following cellulose solution (E) are mixed. Then, the process comprises a step (2) of copolymerizing these to obtain a crosslinked polymer / cellulose composite gel (A / B), and the gist is that it contains cellulose having a type II crystal structure.
Cellulose solution (E): Cellulose is an ionic liquid (D), cellulose soluble solvent, LiCl / DMF solution (dimethylformamide solution of lithium chloride) and LiCl / DMAc solution (N, N-dimethylacetamide solution of lithium chloride) Solution dissolved in cellulose solvent (F) selected from

The gist of the absorbent body of the present invention is that it contains the absorbent resin particles obtained by the above production method .

  The gist of the absorbent article of the present invention is that the absorbent body is used.

The absorbent resin particles of the present invention exhibit high absorption performance despite using plant-derived materials (cellulose).
Moreover, according to the manufacturing method of the absorbent resin particle of this invention, although the plant-derived raw material (cellulose) is used, the absorbent resin particle which exhibits high absorption performance can be manufactured easily.
Moreover, since the absorber of this invention uses said absorbent resin particle, it exhibits high absorption performance.
Moreover, since the absorbent article of this invention uses said absorber, it exhibits high absorption performance.

  The water-soluble vinyl monomer (a1) is not particularly limited, and known {e.g., vinyl monomers disclosed in Japanese Patent No. 3648553, Japanese Patent Laid-Open No. 2003-165883, Japanese Patent Laid-Open No. 2005-75982, Japanese Patent Laid-Open No. 2005-95759} can be used. .

  The hydrolyzable vinyl monomer (a2) means a vinyl monomer that becomes a water-soluble vinyl monomer (a1) by hydrolysis, and is not particularly limited (for example, Japanese Patent No. 3648553, Japanese Patent Application Laid-Open No. 2003-16583, Japanese Patent Application Laid-Open No. 2003-16583). 2005-75982, JP-A-2005-95759} vinyl monomers, and the like can be used. The hydrolysis of the hydrolyzable vinyl monomer may be performed either during polymerization, after polymerization, or both of them, but is preferably after polymerization from the viewpoint of the absorption performance of the resulting absorbent resin particles.

Of these, water-soluble vinyl monomers (a1) are preferable from the viewpoint of absorption performance and the like, more preferably anionic vinyl monomers, next preferably vinyl monomers having a carboxy (salt) group or a sulfo (salt) group, A vinyl monomer having a carboxy (salt) group is preferred, (meth) acrylic acid (salt) is particularly preferred, and acrylic acid (salt) is most preferred.
Of these, water-soluble vinyl monomers (a1) are preferable from the viewpoint of absorption performance and the like, more preferably anionic vinyl monomers, and still more preferably a vinyl group-containing carboxylic acid (salt) having 3 to 30 carbon atoms. Saturated monocarboxylic acid (salt) ((meth) acrylic acid, crotonic acid, cinnamic acid and salts thereof); unsaturated dicarboxylic acid (salt) (maleic acid, fumaric acid, citraconic acid, itaconic acid and salts thereof) ); And monoalkyl (carbon number 1 to 8) ester of the unsaturated dicarboxylic acid (maleic acid monobutyl ester, fumaric acid monobutyl ester, maleic acid ethyl carbitol monoester, fumaric acid ethyl carbitol monoester, Citraconic acid monobutyl ester, itaconic acid glycol monoester, etc.}, particularly preferably unsaturated Carboxylic acid (salt), most preferably acrylic acid (salt).

  The water-soluble vinyl monomer means a vinyl monomer having a property of dissolving at least 100 g in 100 g of water at 25 ° C. The term “hydrolyzable” refers to the property of being hydrolyzed by the action of 50 ° C. water and, if necessary, the catalyst (acid or base) to make it water-soluble. Hydrolysis of the hydrolyzable vinyl monomer may be performed either during polymerization, after polymerization, or both of them, but from the viewpoint of the molecular weight of the resulting absorbent resin particles, etc., is preferable.

The “carboxy (salt) group” means “carboxy group” or “carboxylate group”, and the “sulfo (salt) group” means “sulfo group” or “sulfonate group”. Moreover, (meth) acrylic acid (salt) means acrylic acid, acrylate, methacrylic acid or methacrylate. Examples of the salt include an alkali metal (such as lithium, sodium and potassium) salt, an alkaline earth metal (such as magnesium and calcium) salt or an ammonium (NH ₄ ) salt. Among these salts, alkali metal salts and ammonium salts are preferable from the viewpoint of absorption performance and the like, more preferably alkali metal salts, and particularly preferably sodium salts.

  When either the water-soluble vinyl monomer (a1) or the hydrolyzable vinyl monomer (a2) is used as a structural unit, each may be used alone as a structural unit, or two or more kinds may be used as a structural unit if necessary. The same applies when the water-soluble vinyl monomer (a1) and the hydrolyzable vinyl monomer (a2) are used as constituent units. Further, when the water-soluble vinyl monomer (a1) and the hydrolyzable vinyl monomer (a2) are used as structural units, the content molar ratio (a1 / a2) is preferably 75/25 to 99/1, more preferably. 85/15 to 95/5, particularly preferably 90/10 to 93/7, and most preferably 91/9 to 92/8. Within this range, the absorption performance is further improved.

The cross-linking agent (a3) is not particularly limited, and known {eg, cross-linking agents disclosed in Japanese Patent No. 3648553, JP-A No. 2003-165883, JP-A No. 2005-75982, JP-A No. 2005-95759} can be used.
Among these, from the viewpoint of absorption performance and the like, a crosslinking agent having two or more ethylenically unsaturated groups is preferable, more preferably a poly (meth) allyl ether of a polyol having 2 to 10 carbon atoms, particularly preferably triallyl shea. Nurate, triallyl isocyanurate, tetraallyloxyethane and pentaerythritol triallyl ether, most preferably pentaerythritol triallyl ether.

  The content (mol%) of the crosslinking agent (a3) is preferably 0.001 to 5, more preferably 0.00 based on the number of moles of the water-soluble vinyl monomer (a1) and the hydrolyzable vinyl monomer (a2). 005 to 3, particularly preferably 0.01 to 1. Within this range, the absorption performance is further improved.

  In addition to these monomers, the water-soluble vinyl monomer (a1) and / or the hydrolyzable vinyl monomer (a2) and the cross-linking agent (a3) are essential monomers (a). Possible other vinyl monomers (a4) can be included.

  Other vinyl monomers (a4) that can be copolymerized are not particularly limited and are known {eg, hydrophobicity of Japanese Patent No. 3648553, Japanese Patent Laid-Open No. 2003-165883, Japanese Patent Laid-Open No. 2005-75982, Japanese Patent Laid-Open No. 2005-95759}. Vinyl monomers can be used.

  When the other vinyl monomer (a4) is included, the content (mol%) of the other vinyl monomer (a4) is based on the number of moles of the water-soluble vinyl monomer (a1) and the hydrolyzable vinyl monomer (a2). 0.01-5 is preferable, More preferably, it is 0.05-3, Next, Preferably it is 0.08-2, Most preferably, it is 0.1-1.5. In view of absorption performance and the like, it is most preferable not to use any other vinyl monomer (a4).

  A cross-linked polymer (A) is obtained by copolymerizing a water-soluble vinyl monomer (a1) and / or a hydrolyzable vinyl monomer (a2) and a monomer having the cross-linking agent (a3) as an essential constituent monomer (a). Is obtained. Examples of the copolymerization method include known aqueous solution polymerization {adiabatic polymerization, thin film polymerization, spray polymerization method, etc .; JP-A-55-133413, etc.}, and known reverse-phase suspension polymerization {Japanese Examined Patent Publication No. 54-30710, No. 56-26909 and JP-A-1-5808 etc.}.

  The content (% by weight) of the crosslinked polymer (A) is based on the weight of the crosslinked polymer (A) and the cellulose (B) having a type II crystal structure, from the viewpoint of plant-derived raw material ratio and absorption performance, 40-95 are preferable, More preferably, it is 50-85, Most preferably, it is 60-70.

  Cellulose (B) having a crystal structure of type II means that the crystal structure of cellulose is type II, and diffraction angle 2θ = 12.3 °, 20.2 °, 21. A peak can be observed at 9 °.

  Cellulose is not particularly limited, and natural polysaccharides (cotton, wood-derived pulp, bacterial cellulose, lignocellulose, microbially produced polysaccharides, chitin, chitosan, etc.), regenerated cellulose (for example, cellophane and regenerated fiber, etc.) and microcrystals. A cellulose etc. are mentioned. Of these celluloses, natural polysaccharides and microcrystalline cellulose are preferable, natural polysaccharides are more preferable, and wood-derived pulp is particularly preferable.

  Cellulose includes cross-linked cellulose. Cellulose may be crosslinked by any known method, and may be crosslinked using a crosslinking agent, or may be crosslinked by radiation (radiation such as gamma rays, X-rays or electron beams) and / or heat. . When a crosslinking agent is used, examples of the crosslinking agent include N-methylol compounds having a cyclic moiety in the molecule (such as dimethylolethyleneurea and dimethyloldihydroxyethyleneurea), polycarboxylic acids (tricarbaryl acid citrate and butanetetracarboxylic acid). Etc.), epoxy compounds (ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, glycerol diglycidyl ether, etc.) and the like. These crosslinking agents may be used alone or in combination of two or more.

As a method for converting the crystal structure of cellulose to type II, dissolution treatment (ionic liquid (D), cellulose-soluble solvent, dimethylformamide (hereinafter abbreviated as DMF) solution of lithium chloride (hereinafter abbreviated as LiCl / DMF solution) Alternatively, there is a method such as a dissolution treatment of lithium chloride in an N, N-dimethylacetamide (hereinafter abbreviated as DMAc) solution (hereinafter abbreviated as LiCl / DMAc solution).
In the present invention, the cellulose solvent (F) means an ionic liquid (D), a cellulose-soluble solvent, a LiCl / DMF solution, and a LiCl / DMAc solution.
In the present invention, the cellulose solution (E) means a solution in which cellulose is dissolved in the cellulose solvent (F).

  In the dissolution treatment with the ionic liquid (D), the ionic liquid (D) is not particularly limited as long as the ionic liquid (D) can dissolve cellulose uniformly.

  The ionic liquid (D) includes an ionic liquid composed of an amidinium cation and an anion and an ionic liquid composed of a guanidinium cation and an anion.

  As the amidinium cation, an imidazolinium cation, an imidazolium cation, a tetrahydropyrimidinium cation, a dihydropyrimidinium cation, or the like can be used.

  Examples of imidazolinium cations include 1,2,3,4-tetramethylimidazolinium, 1,3,4-trimethyl-2-ethylimidazolinium, 1,3-dimethylimidazolinium, and 1,3-dimethyl. Examples include -2,4-diethylimidazolinium.

  Examples of the imidazolium cation include 1,3-dimethylimidazolium, 1,3-diethylimidazolium, 1-ethyl-3-methylimidazolium, 1-propyl-3-methylimidazolium, and 1-butyl-3-methylimidazole. And lithium, 1-hexyl-3-methylimidazolium, 1,2,3-trimethylimidazolium, and the like.

  Examples of the tetrahydropyrimidinium cation include 1,3-dimethyl-1,4,5,6-tetrahydropyrimidinium, 1,2,3-trimethyl-1,4,5,6-tetrahydropyrimidinium, Examples include 2,3,4-tetramethyl-1,4,5,6-tetrahydropyrimidinium and 1,2,3,5-tetramethyl-1,4,5,6-tetrahydropyrimidinium.

  Examples of the dihydropyrimidinium cation include 1,3-dimethyl-1,4-dihydropyrimidinium, 1,3-dimethyl-1,6-dihydropyrimidinium, 1,2,3-trimethyl-1,4- Dihydropyrimidinium, 1,2,3-trimethyl-1,6-dihydropyrimidinium, 1,2,3,4-tetramethyl-1,4-dihydropyrimidinium and 1,2,3,4- Examples include tetramethyl-1,6-dihydropyrimidinium.

  The guanidinium cation includes a guanidinium cation having an imidazolinium skeleton, a guanidinium cation having an imidazolium skeleton, a guanidinium cation having a tetrahydropyrimidinium skeleton, and a guanidinium having a dihydropyrimidinium skeleton. Cations and the like can be used.

  Examples of the guanidinium cation having an imidazolinium skeleton include 2-dimethylamino-1,3,4-trimethylimidazolinium, 2-diethylamino-1,3,4-trimethylimidazolinium, 2-diethylamino-1, Examples include 3-dimethyl-4-ethylimidazolinium and 2-dimethylamino-1-methyl-3,4-diethylimidazolinium.

  Examples of guanidinium cations having an imidazolium skeleton include 2-dimethylamino-1,3,4-trimethylimidazolium, 2-diethylamino-1,3,4-trimethylimidazolium, 2-diethylamino-1,3-dimethyl. Examples include -4-ethylimidazolium and 2-dimethylamino-1-methyl-3,4-diethylimidazolium.

  Examples of the guanidinium cation having a tetrahydropyrimidinium skeleton include 2-dimethylamino-1,3,4-trimethyl-1,4,5,6-tetrahydropyrimidinium, 2-diethylamino-1,3,4- Examples include trimethyl-1,4,5,6-tetrahydropyrimidinium and 2-diethylamino-1,3-dimethyl-4-ethyl-1,4,5,6-tetrahydropyrimidinium.

  Examples of guanidinium cations having a dihydropyrimidinium skeleton include 2-dimethylamino-1,3,4-trimethyl-1,4-dihydropyrimidinium and 2-dimethylamino-1,3,4-trimethyl-1. , 6-dihydropyrimidinium, 2-diethylamino-1,3,4-trimethyl-1,4-dihydropyrimidinium, 2-diethylamino-1,3,4-trimethyl-1,6-dihydropyrimidinium, Examples include 2-diethylamino-1,3-dimethyl-4-ethyl-1,4-dihydropyrimidinium and 2-diethylamino-1,3-dimethyl-4-ethyl-1,6-dihydropyrimidinium.

  As the anion, a halogen anion, a pseudohalogen anion, a carboxylate anion, a superacid anion, a sulfonate anion, a phosphate anion and the like can be used.

  Examples of the halogen anion include chlorine anion, bromine anion and iodine anion.

Examples of the pseudohalogen anion include cyan anion (CN ⁻ ), thiocyanate anion (SCN ⁻ ), cyanate anion (OCN ⁻ ), fluorinate anion (CNO ⁻ ) and azide anion (N ₃ ⁻ ).

  As a carboxylic acid anion, a C1-C18 monocarboxylic acid anion, a dicarboxylic acid anion, etc. are used, A formate anion, an acetate anion, a fumarate anion, an oxalate anion, a lactate anion, a pyruvate anion, etc. are mentioned.

  Examples of the super strong acid anion include a borofluoric acid anion, a tetrafluoroboric acid anion, a perchlorate anion, a hexafluorophosphate anion, a hexafluoroantimonate anion, and a hexafluoroarsenate anion.

  As the sulfonate anion, sulfonic acid having 1 to 26 carbon atoms is used, and methanesulfonate anion, p-toluenesulfonate anion, octylbenzenesulfonate anion, dodecylbenzenesulfonate anion, laurylbenzenesulfonate anion, octadecyl. Examples thereof include benzenesulfonate anion, eicosylbenzenesulfonate anion, octanesulfonate anion, dodecanesulfonate anion, and eicosanesulfonate anion.

As the phosphate anion, a phosphate anion (PO ₄ ⁻ ), a phosphate ester anion having 1 to 40 carbon atoms, and the like are used. Phosphate anion, methyl phosphate monoester anion, octyl phosphate monoester anion, octyl phosphate Examples include a diester anion, a lauryl phosphate monoester anion, a lauryl phosphate diester anion, a stearyl phosphate monoester anion, a stearyl phosphate diester anion, an eicosyl phosphate monoester anion, and an eicosyl phosphate diester anion.

  Of these ionic liquids (D), ionic liquids {imidazolium carboxylates and imidazolium halides, etc.] that are liquid at 100 ° C. are preferred from the viewpoint of solubility of cellulose, and more preferably imidazolium acetate and imidazole. Of these, 1-ethyl-3-methylimidazolium chloride and 1-ethyl-2,3-methylimidazolium acetate are particularly preferred.

Cellulose is highly crystalline and does not dissolve in common simple solvents {hexane, toluene, tetrahydrofuran, dimethylformamide, dimethyl sulfoxide, etc.}. As the cellulose-soluble solvent, those capable of uniformly dissolving cellulose can be used. Specifically, JP-A-2006-223152, JP-A-2006-008866, JP-A-2005-076026, JP-A-2002-178387, JP-A-10-080942, JP-A-09-164200, JP-A-2002-028968, JP-A-2001. Cellulose solvent or cellulose solvent described in JP-A No. 017072, JP-A No. 2000-117116, JP-A No. 11-315151, JP-A No. 11-279323, JP-A No. 10-272675, JP-A No. 10-272675, or JP-A No. 08-225681 ZnCl ₂ aqueous solution, Ca (SCN) ₂ aqueous solution, sodium thiocyanate aqueous solution, Cu (ethylenediamine) ₂ (OH) ₂ aqueous solution, Cd (ethylenediamine) ₃ (OH) ₂ aqueous solution, Co (ethylenediamine) ₃ (OH) ₂ Aqueous solution, Ni (ethylene diethylene _{Min) 3 (OH) 2} solution, Zn _{(ethylenediamine) 3 (OH) 2} aqueous solution and a _{Cu (NH 3) 4 (OH} ) 2 aqueous solution, and the like.

  The ionic liquid (D) and the cellulose-soluble solvent may be used alone or in combination. When the ionic liquid (D) and the cellulose-soluble solvent are used in combination, the weight ratio ((D) / cellulose-soluble solvent) is preferably 10/1 to 10/10, more preferably 10 from the viewpoint of absorption performance. / 2 to 10/5.

  As the LiCl / DMF solution and the LiCl / DMAc solution, any solution that can dissolve cellulose uniformly can be used without particular limitation.

  The amount of lithium chloride used (parts by weight) is preferably from 1 to 20, more preferably from 2 to 10, particularly preferably from 3 to 5, from the viewpoint of absorption performance with respect to 100 parts by weight of DMF or DMAc.

In order to dissolve cellulose with the cellulose solvent (F), the cellulose is mixed with the cellulose solvent (F) and dissolved. As a mixing device of cellulose and cellulose solvent (F), known devices {double arm type kneader, internal mixer (Banbury mixer), self-cleaning type mixer, gear compounder, screw type extruder, screw type kneader, mince Machine, cylindrical mixer, V-shaped mixer, ribbon-type mixer, screw-type mixer, double-arm-type mixer, pulverizing-type kneader, groove-type mixer, vertical-type mixer, etc.}. These can be used in combination.
The mixing time (minutes) between cellulose and the cellulose solvent (F) is preferably 5 to 120, more preferably 10 to 90, and particularly preferably 20 to 60, from the viewpoint of absorption performance.

  The mixing temperature (° C.) of the ionic liquid (D) and / or cellulose-soluble solvent and cellulose is preferably 30 to 120, more preferably 50 to 110, and particularly preferably 80 to 100, from the viewpoint of absorption performance. .

  The mixing temperature (° C.) of the LiCl / DMF solution or LiCl / DMAc solution and cellulose is preferably from 80 to 180, more preferably from 100 to 170, and particularly preferably from 120 to 150, from the viewpoint of absorption performance.

  As a method for dissolving cellulose in a LiCl / DMF solution or a LiCl / DMAc solution, it is preferable from the viewpoint of absorption performance that cellulose is dispersed in DMF or DMAc and then lithium chloride is dissolved.

  From the viewpoint of absorption performance, the amount (parts by weight) of cellulose used for mixing is preferably 1 to 180, more preferably 5 to 87, and particularly preferably 10 to 100 parts by weight of the cellulose solvent (F). 71.

The cellulose solution (E) obtained by mixing and dissolving cellulose and the cellulose solvent (F) can be used as it is. When the cellulose solution (E) is used as it is, it is preferable to remove the cellulose solvent (F) from the viewpoint of absorption performance after use. As a method for removing the cellulose solvent (F), it is preferable to remove it by washing with a washing solvent from the viewpoint of absorption performance. The washing solvent is not particularly limited as long as the cellulose solvent (F) is soluble and the cellulose is insoluble, and examples thereof include water, alcohol {methanol, ethanol, isopropyl alcohol, etc.}, acetone, and the like.
As a method for washing, after dispersing the crosslinked polymer / cellulose composite gel (A / B) obtained by mixing the crosslinked polymer (A) and the cellulose solution (E) in a large amount of washing solvent. The crosslinked polymer / cellulose composite gel (A / B) is preferably separated by filtration, centrifugation, or the like, and then washed by filtration, centrifugation, or the like. By removing the cellulose solvent (F), the cellulose becomes cellulose (B) having a type II crystal structure.

  The content (% by weight) of the ionic liquid (D) after removal is preferably 0 to 10, more preferably 0 to 5, particularly preferably 0 to 3, most preferably based on the weight of the absorbent resin particles. 0-1. Within this range, the absorption performance is further improved.

  The content (% by weight) of the ionic liquid is obtained by liquid chromatography after extraction with physiological saline for 3 hours.

  The content (% by weight) of the cellulose-soluble solvent after removal is preferably 0 to 10, more preferably 0 to 5, particularly preferably 0 to 3, and most preferably 0 based on the weight of the absorbent resin particles. ~ 1. Within this range, the absorption performance is further improved.

  In addition, content (weight%) of a cellulose soluble solvent is calculated | required by liquid chromatography etc. after extracting with physiological saline for 3 hours.

  The content (% by weight) of the LiCl / DMF solution or LiCl / DMAc solution after removal is preferably from 0 to 10, more preferably from 0 to 5, particularly preferably from 0 to 3, based on the weight of the absorbent resin particles. Most preferably, it is 0-1. Within this range, the absorption performance is further improved.

  The content (% by weight) of the LiCl / DMF solution or LiCl / DMAc solution can be obtained by liquid chromatography after extraction with physiological saline for 3 hours.

  When the washing solvent contains an organic solvent, the content (% by weight) of the organic solvent after removal is preferably 0 to 10, more preferably 0 to 5, particularly preferably 0, based on the weight of the absorbent resin particles. ~ 3, most preferably 0-1. Within this range, the absorption performance is further improved.

  When water is contained in the washing solvent, the water content (% by weight) after removal is preferably 0 to 20, more preferably 1 to 10, particularly preferably 2 to 8, most preferably based on the weight of the absorbent resin particles. Is 3-6. Within this range, the absorption performance and the breakability of the absorbent resin particles are further improved.

  In addition, the content of the organic solvent and the moisture are an infrared moisture measuring device {JE400 manufactured by Kett Science Laboratory Co., Ltd .: 120 ± 5 ° C., 30 minutes, ambient humidity before heating 50 ± 10% RH, lamp specification 100V , 40W}, obtained from the weight loss of the measurement sample before and after heating.

  The content (% by weight) of the cellulose (B) having a crystal structure of type II is preferably 5 to 60, more preferably 15 to 50, particularly based on the weight of the crosslinked polymers (A) and (B). Preferably it is 30-40. Within this range, the absorption performance is further improved.

  The absorbent resin particle of the present invention is a type II crystal based on the weight of the crosslinked polymer (A) and the cellulose (B) having a type II crystal structure from the viewpoint of plant-derived raw material ratio and absorbent performance of the absorbent article. The content (Z) (% by weight) of the cellulose (B) having a structure is 5 to 60, and the water retention amount (X) (g / g) and 6 of the absorbent resin particles after being immersed in physiological saline for 1 hour. When the absorption amount (Y) (g / g) of the absorbent resin particles after immersion for 1 hour in physiological saline under a load of 2 kPa is (Z) is 5 or more and 15 or less, the formulas (1) and (2 ), More than 15 and 30 or less, equations (3) and (4), 30 to 50 and less than equations (5) and (6), and more than 50 and 60 or less, equations (7) ) And (8) are preferably satisfied. Furthermore, from the viewpoint of the plant-derived raw material ratio and the absorbent performance of the absorbent article, when (Z) (% by weight) is 5 to 60 and (Z) is 5 or more and 15 or less, the formulas (9) and (10) When exceeding 15 and 30 or less, the expressions (11) and (12) are satisfied. When exceeding 30 and not more than 50, the expressions (13) and (14) are satisfied. When exceeding 50 and not more than 60, the expression (15) is satisfied. And (16) is preferably satisfied.

33 ≦ (X) ≦ 40 (1)
20 ≦ (Y) ≦ 28 (2)

30 ≦ (X) ≦ 37 (3)
15 ≦ (Y) ≦ 23 (4)

25 ≦ (X) ≦ 33 (5)
10 ≦ (Y) ≦ 20 (6)

21 ≦ (X) ≦ 28 (7)
7 ≦ (Y) ≦ 13 (8)

36 ≤ (X) ≤ 38 (9)
22 ≦ (Y) ≦ 26 (10)

32 ≦ (X) ≦ 35 (11)
17 ≦ (Y) ≦ 21 (12)

27 ≦ (X) ≦ 31 (13)
12 ≦ (Y) ≦ 18 (14)

23 ≦ (X) ≦ 26 (15)
9 ≦ (Y) ≦ 11 (16)

The water retention amount (X) is measured as follows.
<Measurement method of water retention>
1.00 g of a measurement sample is put into a tea bag (20 cm long, 10 cm wide) made of a nylon net having a mesh size of 63 μm (JIS Z8801-1: 2006), and 1,000 ml of physiological saline (saline concentration 0.9% by weight). After soaking for 1 hour without stirring, hang for 15 minutes and drain. Thereafter, each tea bag is placed in a centrifuge, centrifuged at 150 G for 90 seconds to remove excess physiological saline, and the weight (h1) including the tea bag is measured. Similarly, a blank test is performed using a tea bag that does not contain a measurement sample, the weight (h2) is measured, and the water retention amount is obtained from the following equation. In addition, the temperature of the physiological saline used and measurement atmosphere is 25 degreeC +/- 2 degreeC.

Water retention amount (g / g) = (h1)-(h2)

In addition, the absorption amount (absorption amount under load) (Y) of the absorbent resin particles after being immersed in physiological saline under a load of 6.2 kPa for 1 hour is measured as follows.
<Absorption under load>
0.16 g of a measurement sample sieved to a particle diameter of 250 to 500 μm in a cylindrical plastic tube (inner diameter: 25 mm, height: 34 mm) having a nylon mesh of 63 μm (JIS Z8801-1: 2006) pasted on the bottom. Were weighed and the cylindrical plastic tube was placed vertically so that the measurement sample had a substantially uniform thickness on the nylon mesh, and then a weight (weight: 310.6 g, outer diameter: 24. 5mm,). After measuring the weight (M1) of the entire cylindrical plastic tube, a cylindrical type containing a measurement sample and a weight in a petri dish (diameter: 12 cm) containing 60 ml of physiological saline (salt concentration: 0.9% by weight). Stand the plastic tube vertically and immerse it with the nylon mesh side down, and let stand for 60 minutes. After 60 minutes, pull up the cylindrical plastic tube from the petri dish, tilt it diagonally, remove the dripping water drops, weigh the entire cylindrical plastic tube containing the measurement sample and weight (M2), and Obtain the amount absorbed under load. In addition, the temperature of the physiological saline used and measurement atmosphere is 25 degreeC +/- 2 degreeC.

Absorption under load (g / g) = {(M2)-(M1)} / 0.16

  The absorbent resin particles of the present invention can be easily obtained by the production method of the present invention described below.

A water-soluble vinyl monomer (a1) and / or a hydrolyzable vinyl monomer (a2) and a monomer having a crosslinking agent (a3) as an essential constituent monomer (a) are copolymerized to obtain a crosslinked polymer (A). After obtaining, (A) and cellulose are mixed to obtain a crosslinked polymer / cellulose composite gel (A / B) (1) or a water-soluble vinyl monomer (a1) and / or a hydrolyzable vinyl monomer ( a2) and a monomer having the crosslinking agent (a3) as an essential constituent monomer (a) and cellulose are mixed and then copolymerized to form a crosslinked polymer / cellulose composite gel (A / B). (2) which obtains.

<Step (1)>
In step (1), after obtaining the crosslinked polymer (A) obtained by the above-mentioned method, the crosslinked polymer (A) and cellulose are mixed to form a crosslinked polymer / cellulose composite gel (A / B). It is the process of obtaining.

  As a method of mixing the crosslinked polymer (A) and cellulose, (1) a method of mixing the crosslinked polymer (A) and a hydrous gel comprising water and cellulose; (2) the crosslinked polymer (A) ( A method of mixing dry particles) and cellulose. Among these, the method (1) is preferable from the viewpoint of absorption performance and the like.

  The amount of cellulose used (% by weight) (amount not containing a solvent such as water) is preferably 5 to 60 based on the weight of the crosslinked polymer (A) and cellulose, from the viewpoint of plant-derived raw material ratio and absorption performance. More preferably, it is 15-50, Most preferably, it is 40-50.

  The hydrogel comprising (A) and water obtained by polymerization can be chopped as necessary. When chopping, the size (longest diameter) of the gel after chopping is preferably 50 μm to 10 cm, more preferably 100 μm to 2 cm, and particularly preferably 1 mm to 1 cm from the viewpoint of the drying property of the gel.

  Shredding can be performed by a known method, and can be shredded using a normal shredding device {for example, a bex mill, rubber chopper, pharma mill, mincing machine, impact crusher and roll crusher}. .

  The crosslinked polymer (A) may be one type or a mixture of two or more types.

  The amount (% by weight) of the crosslinked polymer (A) used is preferably 40 to 95, more preferably 50 to 85, and particularly preferably 60 to 70, based on the weight of the crosslinked polymer (A) and cellulose. . Within this range, the absorption performance is further improved.

  The mixing temperature (° C.) of the crosslinked polymer (A) and cellulose is preferably 30 to 150, more preferably 40 to 120, and particularly preferably 50 to 100. Within this range, it becomes easier to mix evenly, and the absorption performance is further improved.

  As a mixing device of the cross-linked polymer (A) and cellulose, known devices {double arm type kneader, internal mixer (Banbury mixer), self-cleaning type mixer, gear compounder, screw type extruder, screw type kneader, Mincing machines, cylindrical mixers, V-shaped mixers, ribbon-type mixers, screw-type mixers, double-armed mixers, grinding kneaders, groove-type mixers, vertical mixers, etc.} can be used. These can be used in combination.

  As the cellulose used, it is preferable to use a cellulose solution (E) from the viewpoint of absorption performance.

  As a method of mixing the crosslinked polymer (A) and the cellulose solution (E), (1) a method of mixing the crosslinked polymer (A), a water-containing gel composed of water, and the cellulose solution (E); (2 ) A method of mixing the crosslinked polymer (A) (dry particles) and the cellulose solution (E) is included. Among these, the method (1) is preferable from the viewpoint of absorption performance and the like.

  The mixing temperature (° C.) of the crosslinked polymer (A) and the cellulose solution (E) is preferably 20 to 150, more preferably 25 to 120, and particularly preferably 30 to 100. Within this range, it becomes easier to mix evenly, and the absorption performance is further improved.

  As a mixing device of the crosslinked polymer (A) and the cellulose solution (E), a known device {double-arm kneader, internal mixer (Banbury mixer), self-cleaning mixer, gear compounder, screw-type extruder, Screw type kneader, minced machine, turbulizer, cylindrical mixer, V-shaped mixer, ribbon type mixer, screw type mixer, double arm type mixer, pulverizing type kneader, groove type mixer, vertical type mixer Can be used. These can be used in combination.

  By mixing the crosslinked polymer (A) and the cellulose solution (E), a crosslinked polymer / cellulose composite gel (A / B) is generated. From the viewpoint of absorption performance, it is preferable to remove the cellulose solvent (F) {(ionic liquid (D), cellulose-soluble solvent, LiCl / DMF solution and LiCl / DMAc solution} after this. As a removal method, it is preferable to remove the cellulose solvent (F) by washing with a washing solvent, which is particularly limited as long as the cellulose solvent (F) is soluble and the cellulose is insoluble. And water, alcohol {methanol, ethanol, isopropyl alcohol, etc.}, acetone, etc. The cellulose crystal structure after removing the cellulose solvent (F) is type II.

  As a method for washing the cellulose solvent (F), the crosslinked polymer / cellulose composite gel (A / B) is dispersed in a large amount of washing solvent and then separated by filtration, centrifugation, etc. It is preferable to wash the crosslinked polymer / cellulose composite gel (A / B) with a washing solvent, and then separate by filtration, centrifugation, or the like. By removing the cellulose solvent (F), the cellulose becomes cellulose (B) having a type II crystal structure.

  The content (% by weight) of the ionic liquid (D) after removal is preferably 0 to 10, more preferably 0 to 5, particularly preferably 0 to 3, most preferably based on the weight of the absorbent resin particles. 0-1. Within this range, the absorption performance is further improved.

  The content (% by weight) of the ionic liquid is obtained by liquid chromatography after extraction with physiological saline for 3 hours.

  The content (% by weight) of the cellulose-soluble solvent after removal is preferably 0 to 10, more preferably 0 to 5, particularly preferably 0 to 3, and most preferably 0 based on the weight of the absorbent resin particles. ~ 1. Within this range, the absorption performance is further improved.

  In addition, content (weight%) of a cellulose soluble solvent is calculated | required by liquid chromatography etc. after extracting with physiological saline for 3 hours.

  The content (% by weight) of the LiCl / DMF solution or LiCl / DMAc solution after removal is preferably from 0 to 10, more preferably from 0 to 5, particularly preferably from 0 to 3, based on the weight of the absorbent resin particles. Most preferably, it is 0-1. Within this range, the absorption performance is further improved.

  The content (% by weight) of the LiCl / DMF solution or LiCl / DMAc solution can be obtained by liquid chromatography after extraction with physiological saline for 3 hours.

  When the washing solvent contains an organic solvent, the content (% by weight) of the organic solvent after removal is preferably 0 to 10, more preferably 0 to 5, particularly preferably 0, based on the weight of the absorbent resin particles. ~ 3, most preferably 0-1. Within this range, the absorption performance is further improved.

  When water is contained in the washing solvent, the water content (% by weight) after removal is preferably 0 to 20, more preferably 1 to 10, particularly preferably 2 to 8, most preferably based on the weight of the absorbent resin particles. Is 3-6. Within this range, the absorption performance and the breakability of the absorbent resin particles are further improved.

  In addition, the content of the organic solvent and the moisture are an infrared moisture measuring device {JE400 manufactured by Kett Science Laboratory Co., Ltd .: 120 ± 5 ° C., 30 minutes, ambient humidity before heating 50 ± 10% RH, lamp specification 100V , 40W}, it is obtained from the weight loss of the measurement sample before and after heating.

<Step (2)>
If the water-soluble vinyl monomer (a1) and / or the hydrolyzable vinyl monomer (a2) and the monomer having the crosslinking agent (a3) as the essential constituent monomer (a) and cellulose can be mixed uniformly, the method can be used. There is no restriction | limiting in this, It can carry out by a well-known method.

  As a mixing device of monomer and cellulose, known devices {double-arm kneader, internal mixer (Banbury mixer), self-cleaning mixer, gear compounder, screw type extruder, screw type kneader, mincing machine, Turbulizers, cylindrical mixers, V-shaped mixers, ribbon-type mixers, screw-type mixers, double-arm type mixers, pulverizing kneaders, groove-type mixers, vertical mixers, etc. can be used. . A plurality of these may be combined.

  The amount of cellulose used (% by weight) is preferably 5 to 60, more preferably 15 to 50, based on the essential constituent monomer (a) and the weight of cellulose, from the viewpoint of plant-derived raw material ratio and absorption performance. Especially preferably, it is 30-40.

  The use amount (% by weight) of the essential constituent monomer (a) is preferably 40 to 95 based on the weight of the essential constituent monomer (a) and cellulose, from the viewpoint of plant-derived raw material ratio and absorption performance, More preferably, it is 50-85, Most preferably, it is 60-70.

  As a method of copolymerizing a monomer having water-soluble vinyl monomer (a1) and / or hydrolyzable vinyl monomer (a2) and crosslinking agent (a3) as essential constituent monomer (a) after mixing with cellulose. Are known aqueous solution polymerization {adiabatic polymerization, thin film polymerization, spray polymerization method, etc .; JP-A-55-133413, etc.] and known reverse phase suspension polymerization {JP-B-54-30710, JP-A-56-26909. No. 1 and Japanese Patent Laid-Open No. 1-5808 etc.}.

  As the cellulose used, it is preferable to use a cellulose solution (E) from the viewpoint of absorption performance.

  Mixing the water-soluble vinyl monomer (a1) and / or the hydrolyzable vinyl monomer (a2) and the monomer having the crosslinking agent (a3) as an essential constituent monomer (a) with the cellulose solution (E) The method is not particularly limited as long as it can be uniformly mixed.

  When using a cellulose solution (E), the usage-amount (weight%) of an essential structural monomer (a) is 40-95 based on the weight of an essential structural monomer (a) and a cellulose solution (E). Is more preferable, 50 to 85 is more preferable, and 60 to 70 is particularly preferable. Within this range, the absorption performance is further improved.

By polymerization, a crosslinked polymer / cellulose composite gel (A / B) is produced.
When the cellulose solution (E) is used, it is preferable to remove the cellulose solvent (F) from the viewpoint of absorption performance, and the removal method of (F) is the same as the removal method in Step 1. The cellulose crystal structure after removal of (F) is type II.

The crosslinked polymer / cellulose composite gel (A / B) obtained in the step (1) or (2) can lead to absorbent resin particles by post-treatment.
Post-processing includes shredding, solvent evaporation (drying), pulverization, particle size adjustment, surface crosslinking, and mixing of additives. These post-processing may be performed in combination, or only one of them may be performed. Moreover, there is no restriction | limiting in the order of post-processing, Although it determines suitably, said order is preferable from a viewpoint of absorption performance. In addition, it is preferable to include drying from a viewpoint of absorption performance among these post-processing. Moreover, when employ | adopting aqueous solution polymerization, it is preferable that a grinding | pulverization is further included from a viewpoint of absorption performance.

<Shred>
Shredding can be performed by a known method, and can be shredded using a known shredding device {for example, a bex mill, rubber chopper, pharma mill, mincing machine, impact crusher and roll crusher}. .

  When shredding, the size (longest diameter) of the composite gel (A / B) after shredding is preferably 50 μm to 10 cm, more preferably 100 μm to 2 cm, and particularly preferably 1 mm to 1 cm. Within this range, in addition to being easier to handle, when the solvent is subsequently distilled off, the solvent is further easily distilled off, and when pulverizing thereafter, the pulverization is further facilitated.

<Solvent evaporation (drying)>
In the copolymerization in the step (1) or (2), when a solvent (such as an organic solvent and water) is used, it is preferable to distill off the solvent from the viewpoint of absorption performance.
When the solvent contains an organic solvent, the content (% by weight) of the organic solvent after the distillation is preferably 0 to 10, more preferably 0 to 5, particularly preferably 0, based on the weight of the absorbent resin particles. ~ 3, most preferably 0-1. Within this range, the absorption performance is further improved.

  When water is contained in the solvent, the water content (% by weight) after distillation is preferably 0 to 20, more preferably 1 to 10, particularly preferably 2 to 8, most preferably based on the weight of the absorbent resin particles. Is 3-6. Within this range, the absorption performance and the breakability of the absorbent resin particles are further improved.

  In addition, the content and moisture of the organic solvent are an infrared moisture measuring device {JE400 manufactured by Kett Science Laboratory Co., Ltd .: 120 ± 5 ° C., 30 minutes, atmospheric humidity before heating 50 ± 10% RH, lamp specification 100V, It is calculated | required from the weight loss of the measurement sample before and behind heating when heated by 40W}.

As a method of distilling off the solvent (including water), a method of distilling (drying) with hot air at a temperature of 80 to 230 ° C., a thin film drying method using a drum dryer heated to 100 to 230 ° C., (heating ) Vacuum drying, freeze drying, infrared drying, etc. can be applied.
Prior to distilling off the solvent, the solvent can be removed by decantation, filtration or the like.

<Crushing>
The pulverization is preferably performed after distilling off the solvent from the viewpoint of absorption performance.
The pulverization method is not particularly limited, and can be pulverized by a known pulverizer (for example, a hammer-type pulverizer, an impact-type pulverizer, a roll-type pulverizer, and a shet airflow-type pulverizer).

<Granularity control>
The size of the pulverized particles is adjusted by sieving or the like as necessary.
The weight average particle diameter (μm) of the pulverized particles is preferably 100 to 800, more preferably 200 to 500, and particularly preferably 300 to 400. Within this range, the absorption performance is further improved. Therefore, it is preferable to adjust the particle size so as to be in this range.

  In addition, the weight average particle size is obtained by measuring the particle size distribution of the measurement sample, and the logarithmic probability paper {horizontal axis: particle size, vertical axis: cumulative content (% by weight)} has a relationship between the cumulative content and the particle size. It is obtained by plotting and determining the particle size corresponding to a cumulative content of 50% by weight. The particle size distribution is measured in accordance with JIS Z8815-1994. For example, sieves having an inner diameter of 150 mm and a depth of 45 mm {openings: 850 μm, 710 μm, 500 μm, 300 μm, 150 μm and 106 μm} are passed through narrow sieves. And put 50 g of the measurement sample on the 710 μm sieve with the widest opening at the top, sieve for 10 minutes with a sieve vibrator, and measure the weight of the measurement sample remaining on each sieve. It is measured by determining the weight percent of the measurement sample remaining on each sieve based on the weight of the first measurement sample.

The smaller the content of fine particles, the better the absorption performance. Therefore, it is preferable to remove the fine particles by sieving or the like.
The content of fine particles of 106 μm or less (preferably 150 μm or less) in all particles is preferably 3% by weight or less, and more preferably 1% by weight or less.
The content of the fine particles can be determined using a plot created when determining the weight average particle diameter.

<Surface cross-linking>
The cut chopped gel or the pulverized particles can be subjected to surface cross-linking treatment with a surface cross-linking agent, if necessary.
As the surface crosslinking agent, known {for example, JP 59-189103, JP 58-180233, JP 61-16903, JP 61-2111305, JP 61-252212, Surface cross-linking agents {polyvalent glycidyl, polyhydric alcohol, polyvalent amine, polyvalent aziridine, polyvalent isocyanate, silane coupling agent and polyvalent metal of JP-A-51-136588 and JP-A-61-257235} Etc.} can be used. Of these surface cross-linking agents, from the viewpoint of economy and absorption performance, polyvalent glycidyl, polyhydric alcohol and polyvalent amine are preferable, more preferably polyvalent glycidyl and polyhydric alcohol, particularly preferably polyvalent glycidyl, Preferred is ethylene glycol diglycidyl ether.

  In the case of surface cross-linking, the amount (% by weight) of the surface cross-linking agent is not particularly limited because it can be changed variously depending on the type of surface cross-linking agent, cross-linking conditions, target performance, etc. From a viewpoint etc., based on the weight of an essential constituent monomer (a), 0.001-3 are preferable, More preferably, it is 0.005-2, Most preferably, it is 0.01-1.

  In the case of surface crosslinking, a known method {for example, Japanese Patent No. 3648553, Japanese Patent Laid-Open No. 2003-165883, Japanese Patent Laid-Open No. 2005-75982, Japanese Patent Laid-Open No. 2005-95759} can be applied.

<Mixing of additives>
For shredded gels, dry particles, pulverized particles or surface cross-linked particles, other additives (for example, known preservatives, fungicides, antibacterial agents (for example, Japanese Patent Application Laid-Open Nos. 2003-225565 and 2006-131767) Agent, antioxidant, ultraviolet absorber, colorant, fragrance, deodorant, inorganic powder, organic fibrous material, etc.}.
When other additives are mixed, the mixing method is not limited as long as uniform mixing is possible, and a known mixing method can be applied.

  The absorbent resin particle of the present invention comprises a water-soluble vinyl monomer (a1) and / or a hydrolyzable vinyl monomer (a2), and a crosslinked polymer (A) having a crosslinking agent (a3) as an essential constituent monomer (a). ) And cellulose having a crystal structure of type II (B), but the copolymer containing a monomer containing the essential constituent monomer (a) in the presence of cellulose (B) When obtaining, it is preferable that the graft ratio of a cellulose (B) and an essential structural monomer (a) is low from a viewpoint of absorption performance. The graft ratio (% by weight) is preferably 70 or less, more preferably 50 or less, particularly preferably 30 or less, then preferably 15 or less, then preferably 5 or less, and most preferably from the viewpoint of absorption performance. 0.

The graft ratio is measured as follows.
The absorbent resin particles are screened with a sieve having an opening of 1 mm, adjusted to a size of 1 mm or less, dried at 100 ° C. for 1 hour, and screened with a sieve having an opening of 150, 300 μm to measure 150 to 300 μm. Prepare a sample. 1.00 g (G1) of a measurement sample was swollen 50 times with water, dispersed in 200 g of 1-ethyl-3-methylimidazolium chloride stirred at 100 ° C. and 500 rpm, maintained for 24 hours, and then filtered. After that, the resin particles are washed with 100 g of 1-ethyl-3-methylimidazolium chloride three times, further washed with 100 g of methanol three times, dried at 100 ° C. for 1 hour, and then dried in weight. (G2) is measured, and the graft ratio is determined from the following equation. In addition, (Z) is content (%) of a cellulose (B) based on the weight of a crosslinked polymer (A) and a cellulose (B).

  The absorbent resin particles of the present invention may contain other additives (for example, known preservatives, fungicides, antibacterial agents, antioxidants, ultraviolet rays (for example, JP 2003-225565 A, JP 2006-131767 A). Absorbers, colorants, fragrances, deodorants, inorganic powders, organic fibrous materials, etc.}.

  100-800 are preferable, as for the weight average particle diameter (micrometer) of the absorptive resin particle | grains of this invention, More preferably, it is 200-500, Most preferably, it is 300-400. Within this range, the absorption performance is further improved.

  The smaller the content of fine particles, the better the absorption performance. Therefore, the content of fine particles of 106 μm or less (preferably 150 μm or less) in all particles is preferably 3% by weight or less, more preferably 1% by weight or less. .

  The shape of the absorbent resin particle of the present invention is not particularly limited, and examples thereof include an irregular crushed shape, a flake shape, a pearl shape, and a rice grain shape. Among these, when applied to a paper diaper or the like, from the viewpoint of good entanglement with the fibrous material, no fear of dropping off from the fibrous material, and from the viewpoint of absorption performance, an irregularly crushed shape and a pearl shape are preferable.

  The absorbent resin particles of the present invention can be used as an absorbent body together with a fibrous material. The structure and production method of the absorber are the same as those known in the art (Japanese Patent Laid-Open No. 2003-225565, Japanese Patent Laid-Open No. 2006-131767, Japanese Patent Laid-Open No. 2005-097569, etc.). Moreover, it is preferable that this absorber comprises absorbent articles {paper diapers, sanitary napkins, etc.}.

  Hereinafter, although an example and a comparative example explain the present invention further, the present invention is not limited to these. Unless otherwise specified, “part” means “part by weight” and “%” means “% by weight”. In addition, water retention amount (X) and absorption amount under load (Y) were measured by the method mentioned above.

<Production Example 1>
Water-soluble vinyl monomer (a1) {acrylic acid, manufactured by Mitsubishi Chemical Corporation, purity 100%} 131.5 parts, crosslinking agent (a3) {pentaerythritol triallyl ether, manufactured by Daiso Corporation} 0.43 parts 366.5 parts of ionic water was kept at 3 ° C. with stirring and mixing. Nitrogen was introduced into the mixture to bring the dissolved oxygen amount to 1 ppm or less, and then 0.53 parts of 1% aqueous hydrogen peroxide solution and 0.99 parts of 2% aqueous ascorbic acid solution were added and mixed to initiate polymerization. . After the temperature of the mixture rose and polymerization started, polymerization was performed for about 8 hours to obtain a crosslinked polymer hydrogel (A1).

<Production Example 2>
Water-soluble vinyl monomer (a1) {acrylic acid, manufactured by Mitsubishi Chemical Corporation, purity 100%} 108.5 parts, crosslinking agent (a3) {pentaerythritol triallyl ether, manufactured by Daiso Corporation} 0.35 parts and desorption Ion water (389.9 parts) was kept at 3 ° C. with stirring and mixing. Nitrogen was introduced into the mixture to bring the dissolved oxygen amount to 1 ppm or less, and then 0.43 part of 1% aqueous hydrogen peroxide solution and 0.81 part of 2% ascorbic acid aqueous solution were added and mixed to initiate polymerization. . After the temperature of the mixture rose and polymerization started, polymerization was performed for about 8 hours to obtain a crosslinked polymer hydrogel (A2).

<Production Example 3>
Water-soluble vinyl monomer (a1) {acrylic acid, manufactured by Mitsubishi Chemical Corporation, purity 100%} 77.45 parts, crosslinking agent (a3) {pentaerythritol triallyl ether, manufactured by Daiso Corporation} 0.25 parts 421.3 parts of ionic water was kept at 3 ° C. with stirring and mixing. Nitrogen was introduced into the mixture to reduce the dissolved oxygen amount to 1 ppm or less, and then 0.31 part of 1% aqueous hydrogen peroxide solution and 0.58 part of 2% ascorbic acid aqueous solution were added and mixed to initiate polymerization. . After the temperature of the mixture rose and polymerization started, polymerization was performed for about 8 hours to obtain a crosslinked polymer hydrogel (A3).

<Production Example 4>
Water-soluble vinyl monomer (a1) {acrylic acid, manufactured by Mitsubishi Chemical Corporation, purity 100%} 62.00 parts, crosslinking agent (a3) {pentaerythritol triallyl ether, manufactured by Daiso Corporation} 0.20 parts and desorption 437.0 parts of ionic water was kept at 3 ° C. with stirring and mixing. Nitrogen was introduced into the mixture to bring the dissolved oxygen amount to 1 ppm or less, and then 0.25 part of a 1% aqueous hydrogen peroxide solution and 0.47 part of a 2% aqueous ascorbic acid solution were added and mixed to initiate polymerization. . After the temperature of the mixture rose and polymerization started, polymerization was carried out for about 8 hours to obtain a crosslinked polymer hydrated gel (A4).

<Production Example 5>
While stirring 135.93 parts of DMF, 6.8 parts of cellulose (1) {KC Flock W-400G, manufactured by Nippon Paper Chemicals Co., Ltd.} are added and dispersed, and 4.08 parts of LiCl is further added. Uniform mixing at 60 ° C. for 60 minutes gave a cellulose solution (E1).

<Production Example 6>
While stirring 1814.80 parts of DMAc, 90.74 parts of cellulose (2) {Theolas TG-101, manufactured by Asahi Kasei Chemicals Co., Ltd.} is added and dispersed therein, and 90.74 parts of LiCl is further added at 150 ° C. By uniformly mixing for 20 minutes, a cellulose solution (E2) was obtained.

<Production Example 7>
While stirring 226.96 parts of 1-ethyl-3-methylimidazolium chloride, 22.70 parts of cellulose (3) {KC Flock W-100GK, manufactured by Nippon Paper Chemicals Co., Ltd.} was added to the mixture at 100 ° C. By uniformly mixing for 90 minutes, a cellulose solution (E3) was obtained.

<Production Example 8>
While stirring 244.74 parts of 1-ethyl-3-methylimidazolium chloride, 24.47 parts of cellulose (4) {Theolas TG-F20, manufactured by Asahi Kasei Chemicals Co., Ltd.} was added thereto, and the mixture was stirred at 100 ° C for 90 minutes. Uniform mixing was performed to obtain a cellulose solution (E4).

<Production Example 9>
While stirring 453.46 parts of 1-ethyl-3-methylimidazolium chloride, 45.35 parts of cellulose (5) {KC Flock W-200G, manufactured by Nippon Paper Chemicals Co., Ltd.} was added thereto, and the mixture was heated at 100 ° C. The mixture was uniformly mixed for 90 minutes to obtain a cellulose solution (E5).

<Production Example 10>
While stirring 475.67 parts of 1-ethyl-3-methylimidazolium chloride, 47.57 parts of cellulose (6) {KC Flock W-300G, manufactured by Nippon Paper Chemicals Co., Ltd.} was added thereto at 100 ° C. The mixture was uniformly mixed for 90 minutes to obtain a cellulose solution (E6).

<Production Example 11>
While stirring 756.31 parts of 1-ethyl-3-methylimidazolium chloride, 75.63 parts of cellulose (7) {NP fiber W-10MG2, manufactured by Nippon Paper Chemicals Co., Ltd.} was added to the mixture at 100 ° C. The mixture was uniformly mixed for 90 minutes to obtain a cellulose solution (E7).

<Production Example 12>
The amount of 1-ethyl-3-methylimidazolium chloride was changed from “226.96 parts” to “692.73 parts”, and the amount of cellulose (3) was changed from “22.70 parts” to “62.97”. A cellulose solution (E8) was obtained in the same manner as in Production Example 7 except that the part was changed to “parts”.

<Production Example 13>
The amount of 1-ethyl-3-methylimidazolium chloride was changed from “226.96 parts” to “907.40 parts”, and the amount of cellulose (3) was changed from “22.70 parts” to “90.74. A cellulose solution (E9) was obtained in the same manner as in Production Example 7 except that the part was changed to “parts”.

<Example 1>
While chopping 400 parts of the crosslinked polymer hydrogel (A1) obtained in Production Example 1 with a mincing machine (12VR-400K manufactured by ROYAL), add 86.93 parts of 48.5% aqueous sodium hydroxide and mix. Subsequently, 146.8 parts of the cellulose solution (E1) obtained in Production Example 5 was added and mixed to obtain a chopped gel. The obtained chopped gel was dispersed in 7000 parts of methanol for 5 hours, filtered, and then washed 3 times with 2000 parts of methanol. Further, the methanol-washed product was dried with a ventilation type band dryer {100 ° C., wind speed 2 m / sec} to obtain a dried product. The dried product was pulverized with a juicer mixer (Osterizer BLENDER manufactured by Oster), and then sieved to adjust the particle size to a particle size range of 710 to 150 μm to obtain pulverized particles. Subsequently, 100 parts of the pulverized particles were stirred at high speed (high-speed stirring turbulizer manufactured by Hosokawa Micron Co., Ltd .: rotation speed 2000 rpm), and a surface cross-linking agent {water / methanol mixture containing ethylene glycol diglycidyl ether at a concentration of 9% Solution (water / methanol = 70/30; weight ratio)} 5.5 parts was added, mixed uniformly, and then allowed to stand at 90 ° C. for 45 minutes to obtain absorbent resin particles (1) of the present invention. . As a result of confirming the obtained absorbent resin particles (1) by X-ray measurement, the cellulose had a type II crystal structure.

<Example 2>
“146.8 parts of the cellulose solution (E1) obtained in Production Example 5” was changed to “149.5 parts of the cellulose solution (E2) obtained in Production Example 6”, and “Surface Crosslinking Agent 5.5” Part ”was changed to“ 5.0 parts of a surface cross-linking agent ”, and the absorbent resin particles (2) of the present invention were obtained in the same manner as in Example 1. As a result of confirming the obtained absorbent resin particles (2) by X-ray measurement, the cellulose had a type II crystal structure.

<Example 3>
Absorbent resin particles (3) of the present invention were obtained in the same manner as in Example 2 except that “5.0 parts of surface cross-linking agent” was changed to “4.5 parts of surface cross-linking agent”. As a result of confirming the obtained absorbent resin particles (3) by X-ray measurement, the cellulose had a type II crystal structure.

<Example 4>
Except having changed "the cellulose solution (E1) 146.8 parts obtained in manufacture example 5" into "the cellulose solution (E3) 249.7 parts obtained in manufacture example 7", it carried out similarly to Example 1, and having changed. The absorbent resin particles (4) of the present invention were obtained. As a result of confirming the obtained absorbent resin particles (4) by X-ray measurement, the cellulose had a type II crystal structure.

<Example 5>
Absorbent resin particles (5) of the present invention were obtained in the same manner as in Example 4, except that “5.5 parts of the surface crosslinking agent” was changed to “4.5 parts of the surface crosslinking agent”. As a result of confirming the obtained absorbent resin particles (5) by X-ray measurement, the cellulose had a type II crystal structure.

<Example 6>
“146.8 parts of the cellulose solution (E1) obtained in Production Example 5” was changed to “269.2 parts of the cellulose solution (E4) obtained in Production Example 8”, and “Surface crosslinking agent 5.5”. Part ”was changed to“ 4.5 parts of a surface cross-linking agent ”, and the absorbent resin particles (6) of the present invention were obtained in the same manner as in Example 1. As a result of confirming the obtained absorbent resin particles (6) by X-ray measurement, the cellulose had a type II crystal structure.

<Example 7>
Absorbent resin particles (7) of the present invention were obtained in the same manner as in Example 6 except that “4.5 parts of surface crosslinking agent” was changed to “3.5 parts of surface crosslinking agent”. As a result of confirming the obtained absorbent resin particles (7) by X-ray measurement, the cellulose had a type II crystal structure.

<Example 8>
“400 parts of the crosslinked polymer hydrogel (A1) obtained in Production Example 1” was changed to “400 parts of the crosslinked polymer hydrogel (A2) obtained in Production Example 2”, and “Manufacturing Example 5 Absorption of the present invention was the same as in Example 1, except that 146.8 parts of the obtained cellulose solution (E1) was changed to “498.8 parts of the cellulose solution (E5) obtained in Production Example 9”. Resin particles (8) were obtained. As a result of confirming the obtained absorbent resin particles (8) by X-ray measurement, the cellulose had a type II crystal structure.

<Example 9>
Absorbent resin particles (9) of the present invention were obtained in the same manner as in Example 8, except that “5.5 parts of surface cross-linking agent” was changed to “4.5 parts of surface cross-linking agent”. As a result of confirming the obtained absorbent resin particles (9) by X-ray measurement, the cellulose had a type II crystal structure.

<Example 10>
Absorbent resin particles (10) of the present invention were obtained in the same manner as in Example 8, except that "5.5 parts of surface crosslinking agent" was changed to "3.5 parts of surface crosslinking agent". As a result of confirming the obtained absorbent resin particles (10) by X-ray measurement, the cellulose had a type II crystal structure.

<Example 11>
“146.8 parts of the cellulose solution (E1) obtained in Production Example 5” was changed to “523.2 parts of the cellulose solution (E6) obtained in Production Example 10” and “Surface crosslinking agent 5. Absorbent resin particles (11) of the present invention were obtained in the same manner as in Example 1 except that “5 parts” was changed to “4.5 parts of surface cross-linking agent”. As a result of confirming the obtained absorbent resin particles (11) by X-ray measurement, the cellulose had a type II crystal structure.

<Example 12>
Absorbent resin particles (12) of the present invention were obtained in the same manner as in Example 11 except that “4.5 parts of surface cross-linking agent” was changed to “3.5 parts of surface cross-linking agent”. As a result of confirming the obtained absorbent resin particles (12) by X-ray measurement, the cellulose had a type II crystal structure.

<Example 13>
Absorbent resin particles (13) of the present invention were obtained in the same manner as in Example 11 except that “4.5 parts of surface crosslinking agent” was changed to “5.0 parts of surface crosslinking agent”. As a result of confirming the obtained absorbent resin particles (13) by X-ray measurement, the cellulose had a type II crystal structure.

<Example 14>
“400 parts of the crosslinked polymer hydrated gel (A1) obtained in Production Example 1” was changed to “400 parts of the crosslinked polymer hydrated gel (A3) obtained in Production Example 3”, and “In Production Example 5” Absorption of the present invention was the same as in Example 1, except that 146.8 parts of the obtained cellulose solution (E1) was changed to “831.9 parts of the cellulose solution (E7) obtained in Production Example 11.” Resin particles (14) were obtained. As a result of confirming the obtained absorbent resin particles (14) by X-ray measurement, the cellulose had a type II crystal structure.

<Example 15>
Water-soluble vinyl monomer (a1) {acrylic acid, manufactured by Mitsubishi Chemical Corporation, purity 100%} 62.00 parts, crosslinker (a3) {pentaerythritol triallyl ether, manufactured by Daiso Corporation} 0.20 parts and production 831.9 parts of the cellulose solution (E7) obtained in Example 11 was kept at 3 ° C. with stirring and mixing. Nitrogen was introduced into the mixture to bring the dissolved oxygen amount to 1 ppm or less, and then 0.25 part of a 1% aqueous hydrogen peroxide solution and 0.47 part of a 2% aqueous ascorbic acid solution were added and mixed to initiate polymerization. . After the temperature of the mixture rose and polymerization started, polymerization was performed for about 8 hours to obtain a crosslinked polymer gel (A5).
While cutting 484.8 parts of the obtained crosslinked polymer gel (A5) with a mincing machine (12VR-400K, manufactured by ROYAL), 51.14 parts of 48.5% aqueous sodium hydroxide solution was added and mixed. A gel was obtained. The obtained chopped gel was dispersed in 10,000 parts of methanol for 5 hours, filtered, and then washed three times with 2000 parts of methanol. Further, the methanol-washed product was dried with a ventilation type band dryer {100 ° C., wind speed 2 m / sec} to obtain a dried product. The dried product was pulverized with a juicer mixer (Osterizer BLENDER manufactured by Oster), and then sieved to adjust the particle size to a particle size range of 710 to 150 μm to obtain pulverized particles. Subsequently, 100 parts of the pulverized particles were stirred at high speed (high-speed stirring turbulizer manufactured by Hosokawa Micron Co., Ltd .: rotation speed 2000 rpm), and a surface cross-linking agent {water / methanol mixture containing ethylene glycol diglycidyl ether at a concentration of 9% Solution (water / methanol = 70/30; weight ratio)} 5.5 parts was added, mixed uniformly, and then allowed to stand at 90 ° C. for 45 minutes to obtain absorbent resin particles (15) of the present invention. . As a result of confirming the obtained absorbent resin particles (15) by X-ray measurement, the cellulose had a type II crystal structure.

<Example 16>
“400 parts of the crosslinked polymer hydrogel (A1) obtained in Production Example 1” was changed to “400 parts of the crosslinked polymer hydrogel (A4) obtained in Production Example 4”, and “In Production Example 5” Absorption of the present invention is the same as in Example 1, except that 146.8 parts of the obtained cellulose solution (E1) is changed to “692.7 parts of the cellulose solution (E8) obtained in Production Example 12”. Resin particles (16) were obtained. As a result of confirming the obtained absorbent resin particles (16) by X-ray measurement, the cellulose had a type II crystal structure.

<Example 17>
Absorbent resin particles (17) of the present invention were obtained in the same manner as in Example 16, except that “5.5 parts of the surface crosslinking agent” was changed to “4.5 parts of the surface crosslinking agent”. As a result of confirming the obtained absorbent resin particles (17) by X-ray measurement, the cellulose had a type II crystal structure.

<Example 18>
Absorbent resin particles (18) of the present invention were obtained in the same manner as in Example 16, except that "Surface cross-linking agent 5.5 parts" was changed to "Surface cross-linking agent 6.0 parts". As a result of confirming the obtained absorbent resin particles (18) by X-ray measurement, the cellulose had a type II crystal structure.

<Example 19>
“400 parts of the crosslinked polymer hydrogel (A1) obtained in Production Example 1” was changed to “400 parts of the crosslinked polymer hydrogel (A4) obtained in Production Example 4”, and “In Production Example 5” Absorption of the present invention was carried out in the same manner as in Example 1, except that “146.8 parts of the obtained cellulose solution (E1)” was changed to “998.1 parts of the cellulose solution (E9) obtained in Production Example 13”. Resin particles (19) were obtained. As a result of confirming the obtained absorbent resin particles (19) by X-ray measurement, the cellulose had a type II crystal structure.

<Example 20>
Water-soluble vinyl monomer (a1) {acrylic acid, manufactured by Mitsubishi Chemical Corporation, purity 100%} 49.60 parts, cross-linking agent (a3) {pentaerythritol triallyl ether, manufactured by Daiso Corporation} 0.16 parts and production 19996.3 parts of the cellulose solution (E2) obtained in Example 6 was kept at 3 ° C. with stirring and mixing. Nitrogen was introduced into the mixture to bring the dissolved oxygen amount to 1 ppm or less, and then 0.20 parts of a 1% aqueous hydrogen peroxide solution and 0.37 parts of a 2% aqueous ascorbic acid solution were added and mixed to initiate polymerization. . After the temperature of the mixture rose and polymerization started, polymerization was performed for about 8 hours to obtain a crosslinked polymer gel (A6).
While cutting 2040.6 parts of the resulting crosslinked polymer gel (A6) with a mincing machine (12VR-400K, manufactured by ROYAL), 49.62 parts of 48.5% aqueous sodium hydroxide solution was added and mixed. A gel was obtained. The obtained chopped gel was dispersed in 20000 parts of methanol for 5 hours, filtered, and washed 3 times with 2000 parts of methanol. Further, the methanol-washed product was dried with a ventilation type band dryer {100 ° C., wind speed 2 m / sec} to obtain a dried product. The dried product was pulverized with a juicer mixer (Osterizer BLENDER manufactured by Oster), and then sieved to adjust the particle size to a particle size range of 710 to 150 μm to obtain pulverized particles. Subsequently, 100 parts of the pulverized particles were stirred at high speed (high-speed stirring turbulizer manufactured by Hosokawa Micron Co., Ltd .: rotation speed 2000 rpm), and a surface cross-linking agent {water / methanol mixture containing ethylene glycol diglycidyl ether at a concentration of 9% Solution (water / methanol = 70/30; weight ratio)} 5.5 parts was added, mixed uniformly, and then allowed to stand at 90 ° C. for 45 minutes to obtain absorbent resin particles (20) of the present invention. . As a result of confirming the obtained absorbent resin particles (20) by X-ray measurement, the cellulose had a type II crystal structure.

<Comparative Example 1>
4000 parts of a 5% aqueous solution of carboxymethyl cellulose (Aldrich, substitution degree 0.7) and 1000 parts of a 5% aqueous solution of polyvinyl alcohol (Wako Pure Chemical Industries, Ltd., weight average molecular weight 44000, saponification degree 88 mol%) Was stirred and mixed at 80 ° C. for 5 hours to obtain a mixed aqueous solution. Next, 50 parts of 40% glyoxal aqueous solution and 2.5 parts of concentrated sulfuric acid were added to this mixed aqueous solution, stirred uniformly, and then allowed to stand in a hot air dryer at 100 ° C. for 7 hours to dry the crosslinking reaction. As a result, a dried product was obtained. The dried product was pulverized with a juicer mixer (Osterizer BLENDER, manufactured by Oster Co., Ltd.) and then sieved with a sieve having openings of 710 μm and 150 μm to obtain comparative absorbent resin particles (H1).

<Comparative Example 2>
While 100 parts of the absorbent resin particles (H1) obtained in Comparative Example 1 were stirred at high speed (high speed stirring turbulizer manufactured by Hosokawa Micron Corporation: rotation speed 2000 rpm), a surface crosslinking agent {ethylene glycol diglycidyl ether was added thereto. 5.0 parts of water / methanol mixed solution (water / methanol = 70/30; weight ratio) contained at a concentration of 9% was added, mixed uniformly, and then allowed to stand at 90 ° C. for 45 minutes for comparison. Absorbent resin particles (H2) were obtained.

<Comparative Example 3>
Absorbent resin particles (H3) for comparison were obtained in the same manner as in Comparative Example 1 except that the standing time in the hot air dryer was changed from “7 hours” to “10 hours”.

  About the absorptive resin particle obtained in Examples 1-20 and Comparative Examples 1-3, the amount of water retention and the amount of absorption under load were evaluated, and these results are shown in Table 1.

  As can be seen from Table 1, the absorbent resin particles (Examples 1 to 20) of the present invention have a water retention amount, an absorbed amount under load, and a type II crystal structure as compared with the absorbent resin particles of Comparative Examples 1 to 3. The balance of the content of cellulose (B) contained was remarkably excellent.

  Using the absorbent resin particles obtained in Examples 1 to 20 and Comparative Examples 1 to 3, absorbers and absorbent articles (paper diapers) were prepared as follows, and surface dryness values by the SDME method were evaluated. The results are shown in Table 2.

<Preparation of absorbent articles (paper diapers)>
120 parts of fluff pulp and 80 parts of an evaluation sample {absorbent resin particles} were mixed with an airflow type mixing apparatus {Pad former manufactured by Autech Co., Ltd.} to obtain a mixture. m ² and so as to uniformly acrylic plate stacked on (thickness 4 mm), and pressed for 30 seconds at a pressure of 5Kg / cm ^2, to obtain an absorbent. The absorbent body is cut into a 14 cm × 36 cm rectangle, and water absorbent paper (basis weight: 15.5 g / m ² , manufactured by Advantech Co., Ltd., filter paper No. 2) having the same size as the absorbent body is arranged above and below each. A paper diaper was prepared by arranging a polyethylene sheet (polyethylene film UB-1 manufactured by Tamapoly Co., Ltd.) on the back surface and a non-woven fabric (basis weight 20 g / m ² , Eltas Guard manufactured by Asahi Kasei Co., Ltd.) on the surface.

<Surface dryness value by SDME method>
A disposable diaper (artificial urine (0.03% by weight of potassium chloride, 0.08% by weight of magnesium sulfate, 0.08% by weight of magnesium sulfate, 0.8% by weight of sodium chloride) in which the detector of the SDME (Surface Dryness Measurement Equipment) tester (manufactured by WK system) % And deionized water 99.09% by weight) and a paper diaper was soaked for 60 minutes. }, A 0% dryness value was set, and then the detector of the SDME tester was prepared by drying a paper diaper {paper diaper at 80 ° C. for 2 hours by heating. } Was set to 100% dryness, and the SDME tester was calibrated. Next, set a metal ring (inner diameter 70 mm, length 50 mm) in the center of the paper diaper to be measured, inject 80 ml of artificial urine, and absorb the artificial urine {until no gloss can be confirmed by artificial urine}, immediately The metal ring was removed, an SDME detector was placed in the center of the paper diaper, and measurement of the surface dryness value was started. The value 5 minutes after the start of measurement was taken as the surface dryness value. The artificial urine, measurement atmosphere, and standing atmosphere were 25 ± 5 ° C. and 65 ± 10% RH.

  As can be seen from Table 2, the absorbent article using the absorbent resin particles of the present invention has a surface dryness value and a type II crystal structure as compared with an absorbent article using comparative absorbent resin particles. The balance of the content of (B) was remarkably excellent. Therefore, it is easily predicted that the absorbent article to which the absorbent resin particles of the present invention are applied has little environmental load and there is no fear of leakage or fog.

  The absorbent resin particles of the present invention can be applied to an absorbent body containing absorbent resin particles and a fibrous material, and absorbent articles {paper diapers, sanitary napkins, and medical blood retaining bodies comprising the absorbent body. It is useful for the agent}. In addition, pet urine absorbent, urine gelling agent for portable toilets, freshness preservation agent for fruits and vegetables, drip absorbent for meat and seafood, cooler, disposable warmer, battery gelling agent, water retention agent for plants and soil, dew condensation It can also be used in various applications such as inhibitors, water-stopping agents, packing agents and artificial snow.

Claims (5)

A water-soluble vinyl monomer (a1) and / or a hydrolyzable vinyl monomer (a2) and a monomer having a crosslinking agent (a3) as an essential constituent monomer (a) are copolymerized to obtain a crosslinked polymer (A). (1) After obtaining (A) and the following cellulose solution (E) to obtain a crosslinked polymer / cellulose composite gel (A / B) or water-soluble vinyl monomer (a1) and / or water A monomer having the decomposable vinyl monomer (a2) and the crosslinking agent (a3) as an essential constituent monomer (a) and the following cellulose solution (E) are mixed and then copolymerized to form a crosslinked polymer. / The manufacturing method of the absorbent resin particle which contains the process (2) which obtains a cellulose composite gel (A / B), and contains the cellulose which has a II type crystal structure.
Cellulose solution (E): Cellulose is an ionic liquid (D), cellulose soluble solvent, LiCl / DMF solution (dimethylformamide solution of lithium chloride) and LiCl / DMAc solution (N, N-dimethylacetamide solution of lithium chloride) Solution dissolved in cellulose solvent (F) selected from
The content (Z) (% by weight) of (B) based on the weight of the crosslinked polymer (A) and the cellulose (B) having a type II crystal structure is 5 to 60, and after being immersed in physiological saline for 1 hour The water retention amount (X) (g / g) of the absorbent resin particles and the absorption amount (Y) (g / g) of the absorbent resin particles after being immersed in physiological saline under a load of 6.2 kPa for 1 hour, When (Z) is 5 or more and 15 or less, the formulas (1) and (2) are satisfied. When it is greater than 15 but 30 or less, the expressions (3) and (4) are satisfied. ) And (6), the method of producing absorbent resin particles according to claim 1 satisfying the formulas (7) and (8) when the ratio exceeds 50 and is 60 or less.
33 ≦ (X) ≦ 40 (1)
20 ≦ (Y) ≦ 28 (2)

30 ≦ (X) ≦ 37 (3)
15 ≦ (Y) ≦ 23 (4)

25 ≦ (X) ≦ 33 (5)
10 ≦ (Y) ≦ 20 (6)

21 ≦ (X) ≦ 28 (7)
7 ≦ (Y) ≦ 13 (8) Based on the weight of the crosslinked polymer (A) and the cellulose (B) having the type II crystal structure, the content of (A) is 40 to 95% by weight, and the content of (B) is 5 to 60% by weight. The manufacturing method of the absorptive resin particle of a certain 1 or 2. The absorber containing the absorptive resin particle obtained by the manufacturing method in any one of Claims 1-3. An absorbent article using the absorber according to claim 4 .