JP2002035580A - Absorbent composition and absorbable article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an absorbent composition having excellent absorbing capacity (absorbing quantity, water holding quantity, absorbing speed, repeated absorbability or the like) with respect to blood as compared with a conventional water absorbable resin insufficient in the absorbing capacity of blood and to provide an absorbable article using the same. SOLUTION: The absorbent composition having excellent absorbing characteristics with respect to blood is obtained by treating a water absorbable resin with a surfactant having specific physical properties or the surfactant and carboxylic acids.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an absorbent composition. More specifically, an absorbent composition comprising a water-absorbent resin and a surfactant having specific physical properties, or a water-absorbent resin, a surfactant and an organic carboxylic acid, and particularly having excellent blood absorption properties, production The present invention relates to a method and an absorbent article using the same.

[0002]

2. Description of the Related Art As an attempt to improve the blood absorption characteristics of a water-absorbing resin which has been widely used as an absorbent composition for absorbent articles such as disposable diapers and sanitary napkins, an attempt has been made to improve the water-absorbing resin and anionic interface. Composition comprising a surfactant and / or a nonionic surfactant having a HLB of 7 or more
No. -32641) has been proposed. However, although this method improves the absorbability of blood to some extent, it is still insufficient for practical use, and has a problem that gel blocking and mamako tend to occur when it comes into contact with blood, and particularly poor repeat absorbability. The main purpose of this method is to prevent the blocking phenomenon between the swollen gels by modifying the surface state of the water-absorbent resin. However, although this method improves the first blood absorption characteristics to some extent, When blood is repeatedly absorbed, blood cell components and protein components of blood are deposited on the surface of the water-absorbent resin, or blood coagulation occurs before absorbing the next blood,
The blood absorption speed becomes extremely slow, and the blood absorption amount becomes low. These phenomena cannot be evaluated by measurement using artificial blood, artificial blood, or physiological saline. The reason is that, in addition to the high viscosity of blood, blood contains about 45% by volume of solid components such as blood cell components such as red blood cells, white blood cells, and platelets, and high molecular weight substances such as cells and proteins. This is because they aggregate or deposit and hinder the absorption of blood into the water absorbent resin. Specifically, in the case of the conventional water-absorbent resin, the water retention amount with respect to physiological saline is 40
g / g, even if the water holding capacity for artificial blood is 37 g / g, the water holding capacity for blood may be as low as about 10 g / g.

[0003]

The problem to be solved by the present invention is disclosed in Japanese Patent Application Laid-Open No. 11-4 / 1999.
Japanese Patent No. 7588 discloses that a water-absorbent resin has a content of 20 to 900.
Proposals have been made to improve the amount of blood drawn by including water by weight. According to this method, although the repetitive absorbability of blood is improved to some extent, when such a high water content is used, the fluidity of the water-absorbent resin powder itself is reduced, making it difficult to treat the powder as a powder. A problem arises in handling properties when processing into articles. In particular, when the water content is 100% or more, the water-absorbent resin is in a gel state, so that it is extremely difficult to uniformly mix with a fibrous material such as fluff pulp or synthetic fiber using a conventional apparatus, or to uniformly form tissue. Spraying becomes difficult. In addition,
As the blood absorbing composition, an absorbing composition containing a polyamino acid salt (JP-A-7-310021) and a reactive hydrophilic compound chemically bonded to a water-swellable polymer are contained to form a blood contact angle on the surface. , Etc. (Japanese Patent Application Laid-Open No. 9-509343) have been proposed, but they have not always been practically satisfactory in terms of the repeated absorption of blood. An object of the present invention is to obtain an absorbent composition having excellent blood absorption performance (absorption amount, water retention amount, absorption rate, and repeated absorption), and having good handling properties when processed into an absorbent article. Another object of the present invention is to provide an absorbent article using the absorbent composition of the present invention.

[0004]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, have reached the present invention. That is, the present invention comprises a water-absorbent resin (A) and the following surfactant (B), wherein the ratio of (A) to (B) is 100: (0.05 to 5) on a mass basis, and The absorption composition according to any one of claims 1 to 3, wherein the absorption rate of horse blood is 60 seconds or less for the first time and 500 seconds or less for the second time. [Surfactant (B)] The surface tension of a 1% aqueous solution at 25 ° C. is 40 mN / m or less, and the sedimentation rate of wool felt by the campus method of a 1% aqueous solution at 25 ° C. is 30 seconds or less. A surfactant; and a carboxylic acid (C) having a carbon number of 10 or less, wherein (A) and (C)
Is an absorbent composition having a ratio of 100: (0.1 to 10) by mass; and a method for producing the present absorbent composition; and an absorbent article using the absorbent composition of the present invention. . [Measurement method of blood absorption rate]: 0.5 g of the absorbent composition was evenly spread on a Petri dish of φ60 mm, and 2.5 g of horse blood was dropped at the center in 2 seconds until the absorption was completed. The time is measured and used as the first absorption rate. 1
Ten minutes after the end of the second measurement of the absorption rate, 2.5 g of horse blood is dropped again, and the time until the absorption is completed is measured to obtain the second absorption rate.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a water absorbent resin (A)
Examples thereof include a starch-acrylate copolymer cross-linked product, a starch-acrylonitrile copolymer saponified product, a polyacrylate cross-linked product, a self-cross-linked polyacrylate, (meth) acrylate-vinyl acetate Cross-linked saponified copolymer, cross-linked isobutylene / maleic anhydride copolymer, cross-linked polysulfonate, cross-linked polyacrylate / polysulfonate copolymer, polyacrylic acid / polyacrylamide copolymer A crosslinked product, a crosslinked polyacrylamide and a hydrolyzate thereof, a crosslinked polyvinylpyrrolidone, a crosslinked cellulose derivative and the like can be mentioned.
Preferably, a polymerizable monomer containing a carboxylate and / or carboxylic acid capable of absorbing and retaining a large amount of liquid by ionic osmotic pressure and having little water separation even when a load or an external force is applied is used as a main component. And more preferably a crosslinked product of a starch-acrylate copolymer and a crosslinked polyacrylate. When (A) is a water-absorbing resin in the form of a neutralized salt, the type of salt and the degree of neutralization are not particularly limited, and the type of salt is usually an alkali metal salt, preferably a sodium salt and a potassium salt. Yes, the degree of neutralization with respect to acid groups is usually 50 to 90 mol%, preferably 60 to 80 mol%.

(A) can be produced by polymerizing a water-soluble monomer with a crosslinking agent and / or a polysaccharide (starch, cellulose, etc.). Examples of the water-soluble monomer used in the production of (A) include a radical-polymerizable water-soluble monomer having a carboxyl group, a sulfonic acid group, and a phosphoric acid group, and salts thereof. Examples of the radically polymerizable water-soluble monomer having a carboxyl group include unsaturated mono- or poly (divalent to hexavalent) carboxylic acid [(meth) acrylic acid (acrylic acid and / or methacrylic acid.
Hereinafter, the same description is used), maleic acid, monoalkyl maleate (C1-9) ester, fumaric acid, monoalkyl fumarate (C1-9) ester, crotonic acid, sorbic acid, itaconic acid, itacone Monoalkyl (C1-9) ester, glycol itaconate monoether, cinnamic acid, citraconic acid, monoalkyl citraconic (C1-9) ester, etc.] and their anhydrides [maleic anhydride, etc.] And the like.

Examples of the radically polymerizable water-soluble monomer having a sulfonic acid group include fatty acids or aromatic vinyl sulfonic acids (vinyl sulfonic acid, allyl sulfonic acid, vinyl toluene sulfonic acid, styrene sulfonic acid, etc.),
(Meth) acrylalkyl sulfonic acid [sulfoethyl (meth) acrylate, sulfopropyl (meth) acrylate, etc.], (meth) acrylamidoalkyl sulfonic acid [2
-Acrylamide-2-methylpropanesulfonic acid and the like]
And the like. Examples of the radical polymerizable water-soluble monomer having a phosphate group include (meth) acrylic acid hydroxyalkyl phosphate monoester [2-hydroxyethyl (meth) acryloyl phosphate, phenyl-2-
Acryloyloxyethyl phosphate and the like]. Salts of the above-mentioned water-soluble monomers containing a carboxyl group, a sulfonic acid group, and a phosphoric acid group [eg, alkali metal salts (sodium salt, potassium salt, etc.), alkaline earth metal salts (calcium salt, magnesium salt, etc.), amines] Or ammonium salt). These may be used in combination of two or more. Preferred water-soluble monomers among these are
Radical polymerizable water-soluble monomers having a carboxyl group and salts thereof, more preferably unsaturated mono- or polycarboxylic acids and salts thereof, and particularly preferably (meth) acrylic acid and salts thereof.

Examples of the crosslinking agent used in the production of (A) include a crosslinking agent having two or more ethylenically unsaturated groups, a crosslinking agent having an ethylenically unsaturated group and a reactive functional group, and a reactive agent. Crosslinking agents having two or more functional groups are exemplified. Specific examples of the compound having two or more ethylenically unsaturated groups include N, N'-methylenebis (meth) acrylamide, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate,
Examples include propylene glycol di (meth) acrylate, glycerin (di or tri) acrylate, trimethylolpropane triacrylate, triallylamine, triallyl cyanurate, triallyl isocyanurate, tetraallyloxyethane, and pentaerythritol triallyl ether. Specific examples of the compound having an ethylenically unsaturated group and a reactive functional group include glycidyl (meth) acrylate, N-methylol (meth) acrylamide, and the like. Specific examples of the compound having two or more reactive functional groups include polyhydric alcohols (for example,
Examples include ethylene glycol, diethylene glycol, glycerin, propylene glycol, trimethylolpropane, etc.), alkanolamines (eg, diethanolamine, etc.), and polyamines (eg, polyethyleneimine, etc.). Two or more of these crosslinking agents may be used in combination. Of these, preferred are copolymerizable crosslinking agents having two or more ethylenically unsaturated groups, more preferably N, N'-methylenebisacrylamide, ethylene glycol diacrylate, trimethylolpropane triacrylate, tetramethyl Allyloxyethane, pentaerythritol triallyl ether and triallylamine.

The amount of the crosslinking agent used is usually 0.001 to 5% based on the total mass of the water-soluble monomer and the crosslinking agent,
Preferably 0.05-2%, particularly preferably 0.1-1
%. When the amount of the crosslinking agent is less than 0.001%, the water absorbing / water retaining ability, which is an important function of the water absorbent resin, becomes small, and the gel after water absorption becomes a sol. Furthermore, the drying properties of the hydrogel polymer after polymerization are poor, and the productivity is inefficient. On the other hand, if it exceeds 5%, on the other hand, the crosslinking becomes too strong, and the water absorption / water retention capacity decreases. Furthermore, the absorption rate is also slowed.

In the production of the water-absorbent resin (A), the polymerization method is not particularly limited, and examples thereof include an aqueous solution polymerization method, a reversed phase suspension polymerization method, a spray polymerization method, a photoinitiated polymerization method, and a radiation polymerization method. . A preferred polymerization method is a method of performing aqueous solution polymerization using a radical polymerization initiator. In this case, the kind and amount of the radical polymerization initiator and the radical polymerization conditions are not particularly limited, and may be normal. In addition, various additives, chain transfer agents (for example, thiol compounds, etc.) may be added to these polymerization systems as needed.

The water-containing gel-like polymer of the water-absorbent resin obtained by polymerization is dried, pulverized, and, if necessary, the particle size is adjusted to adjust the vicinity of the surface of the absorbent particles to an acid group such as a carboxyl group and / or Water-absorbing resin (A) by surface cross-linking with a cross-linking agent having at least two functional groups capable of reacting with the base
It can also be. Such a surface-crosslinked type water-absorbing resin is suitable for the present invention because it has excellent absorption performance and absorption speed under normal pressure as well as under pressure, and has high gel strength. As a cross-linking agent used for surface cross-linking, a known cross-linking agent which has been conventionally used can be applied. As a specific example, a polyglycidyl ether compound having 2 to 10 epoxy groups in one molecule [ethylene glycol diglycidyl ether, glycerin-1,3-diglycidyl ether, glycerin triglycidyl ether,
Polyethylene glycol (degree of polymerization 2-100) diglycidyl ether, polyglycerol (degree of polymerization 2-100)
Polyglycidyl ether, etc.]; divalent to 20-valent polyol compound [glycerin, ethylene glycol, polyethylene glycol (degree of polymerization 2 to 100), etc.]; divalent to 20
Polyamine compounds (e.g., ethylenediamine, diethylenetriamine); polyamine resins having a molecular weight of 200 to 500,000 (e.g., polyamide polyamine epichlorohydrin resin, polyamine epichlorohydrin resin), alkylene carbonates (e.g., ethylene carbonate), aziridine compounds, oxazoline compounds, polyimine compounds, etc. Is mentioned. Among them, preferred is that the surface crosslinking can be performed at a relatively low temperature.
A polyglycidyl ether compound, a polyamine resin and an aziridine compound.

The amount of the cross-linking agent in the surface cross-linking can be variously changed depending on the type of the cross-linking agent, cross-linking conditions, target performance, and the like. 0.001 to 3% by weight, preferably 0.01 to 2% by weight, more preferably 0.05 to 1% by weight.
% By weight. When the amount of the crosslinking agent is less than 0.001% by weight, there is no significant difference in performance from a water-absorbing resin that does not undergo surface crosslinking.
On the other hand, if it exceeds 3% by weight, the absorption performance tends to decrease, which is not preferable. The average particle size (mass median particle size) of the powder of the water-absorbent resin (A) is not particularly limited.
Particles having a particle size of from 00 to 600 microns and a particle size in the range of from 100 to 850 microns can be used in such a manner that the particles are 95% by mass or more. Preferably the average particle size is 200
５550 microns, with particles ranging from 150 to 850 microns being 95% by weight or more. The amount of water-absorbent resin (A) absorbed in physiological saline is the same as that of a normal water-absorbent resin, and the amount of absorption is 30 to 70 g / g, preferably 3 to 70 g / g.
5 to 65 g / g. In addition, the absorption amount with respect to physiological saline was measured by the following method. [Measurement method of absorption amount in physiological saline]: Tea bag made of nylon mesh of 250 mesh (length 20c)
m, 10cm in width), 850-15 with JIS standard screen
1 g of an absorbent sample adjusted to a particle size of 0 μm is put therein, immersed in 500 ml of physiological saline (0.90% aqueous sodium chloride solution) for 30 minutes to absorb the suspension, suspended for 15 minutes and drained, and then the increased mass is measured. Measure to determine the amount of absorption for physiological saline.

The surfactant (B) in the present invention is 1%
The surface tension of the aqueous solution is 40 mN / m or less, preferably 10 mN / m.
-30 mN / m, particularly preferably 10-27 mN / m, and the sedimentation speed of wool felt by a 1% aqueous solution campus method is usually 30 seconds or less, preferably 0 to 20 mN / m.
Seconds, particularly preferably 0 to 10 seconds. When the surface tension of the 1% aqueous solution (B) is 10 to 40 mN / m, and the sedimentation speed of the 1% aqueous solution does not satisfy either or both of 30 seconds or more, the result is that the repetitive absorbability is poor. Only when a surfactant that satisfies both of these physical properties is used, excellent blood absorption properties are exhibited. The surface tension of a 1% aqueous solution of (B) was determined by the Willie-Helmy method (platinum pulling method,
25 ° C). The sedimentation rate of wool felt in the 1% aqueous solution by the canvas method was such that a 2 mm thick wool felt campus cut into 2 x 2 cm squares was gently floated on the surface of the aqueous solution (25 ° C). It is determined by measuring the time (in seconds) before starting to perform. For example, wool felt manufactured by Nippon Kaori can be used.

Specific examples of the surfactant (B) include: (1) polyoxyalkylene fatty acid ester: having 4 carbon atoms
Alkylene (2-4 carbon atoms) oxide (1-100 mol) adduct of a fatty acid having 24 to 24 moles [eg, 2-ethylhexanoic acid ethylene oxide 2 mol adduct, lauric acid ethylene oxide 4-5 mol adduct, stearin (2) Sorbitan fatty acid ester and its alkylene oxide adduct: fatty acid of sorbitan (carbon number of 8 to 1)
5) Ester (for example, sorbitan monolaurate, sorbitan monopalmitate) and its alkylene (2-4 carbon atoms) oxide addition (1-30)
(3) polyoxyalkylene modified silicone: alkylene (2-4 carbon atoms) modified (3-25 mol addition) silicone (siloxane polymerization) Degree: 3 to 15), and the addition of the alkylene oxide may be at any of the side chain, both terminals, and one terminal [for example, polyethylene oxide 10 mol side chain modified silicone (siloxane polymerization degree: 10), polypropylene-polyethylene oxide (PO / EO) Number of moles added: 1/19 to 19/1, either random addition or block addition is possible.) Modified silicone (siloxane polymerization degree;
3 to 15) and the like];

(4) Sulfonate: alkyl (having 2 carbon atoms)
-16) benzenesulfonate (sodium dodecylbenzenesulfonate), α-olefin sulfonate (sodium 1-decylsulfonate, 3-hydroxy-
Sodium 1-decylsulfonate), sulfosuccinic acid diester salt (sodium sulfosuccinate di-2-ethylhexyl ester, etc.), and Igepon T-type surfactant (N-
(5) Alkanolamine salt of fatty acid: having 8 to 24 carbon atoms.
Having 4 to 4 carbon atoms of a hydroxyalkyl group of a saturated fatty acid [e.g., caprylic acid, 2-ethylhexanoic acid, lauric acid, myristic acid, stearic acid, isostearic acid, etc.]
18 alkanolamines (1 to 3 tertiary) [for example, primary amines such as monoethanolamine and monopropanolamine, methyl monoethanolamine, methyl propanolamine, ethyl isopropanolamine, diethanolamine, diisopropanolamine, di-n- Secondary amines such as hexanolamine, tertiary amines such as triethanolamine and tripropanolamine] salts and the like; (6) fatty acid (C24-C24) alkanolamides:
It is a polyhydric alcohol type nonionic surfactant having an amide bond, and examples thereof include those synthesized by condensation of an alkanolamine and a fatty acid. The same alkanolamines and fatty acids as those described in the above (1) can be used. The fatty acid alkanolamide may be in the form of 1: 1 mol or 1: 2 mol. (1: 1 mol type is a condensation product of 1 mol of fatty acid and 1 mol of alkanolamine, and 1: 2 mol type is a condensation mixture of 2 mol of alkanolamine to 1 mol of fatty acid and 1 mol of alkanolamine. Is condensed with 1 mole of fatty acid and 1 mole of alkanolamine is loosely bound to the amide, specifically, [1: 1 mole of lauric acid diethanolamide, oleic acid diethanolamide, coconut oil fatty acid monoethanolamide, etc.] Type fatty acid alkanolamide, 1: 2 mol type fatty acid alkanolamide, etc.];

(7) Quaternary ammonium salt: a tetraalkylammonium salt having one alkyl group having 1 to 1 carbon atom
And the alkyl groups may be the same or different, but at least one alkyl group has 8 carbon atoms.
~ 18. (For example, octyltrimethylammonium chloride, lauryltrimethylammonium chloride, dimethyldilaurylammonium chloride,
(8) Alkylene oxide adducts of alcohols: alkylenes of alcohols having 4 to 26 carbon atoms (2 to 4 carbon atoms), such as stearyltrimethylammonium methyl sulfate and tridecylmethylammonium chloride).
Oxide adducts (4 to 30 mol) [e.g., polypropylene / ethylene oxide (0 to 10 mol / 3 to 24 mol block or random) adducts of aliphatic (C4 to C26) branched alcohols (e.g., isolauryl alcohol 5 to 15 mol ethylene oxide adduct, 10 to 24 mol ethylene oxide adduct of isotetracosane alcohol, etc.): (8) Others: alkyl phosphate having 8 to 24 carbon atoms (for example, octyl acid phosphate, etc.) ), Salts of alkyl (4 to 13) amine ethylene oxide (1 to 30 mol) adducts of fatty acids (8 to 18 carbon atoms) (eg, salts of 2 mol of stearylamine ethylene oxide adduct of 2-ethylhexanoic acid) And the like, and one or more of these can be used.

Of these, preferred are polyoxyalkylene fatty acid esters, polyoxyalkylene modified silicones, sorbitan fatty acid esters, sulfonates, alkylene oxide adducts of alcohols and the like, which do not react with the water absorbing resin at 50 ° C. or lower. Surfactants, more preferred are polyoxyethylene fatty acid esters, polyoxyethylene modified silicones, alkylbenzene sulfonates, ethylene oxide adducts of alcohols, etc., and particularly preferred are ethylene oxide laurate (4 to 5 mol) adduct, 5 to 15 mol of ethylene oxide of isolauryl alcohol, 10 to 10 mol of ethylene oxide of isotetracosane alcohol
24 mole adduct, polyethylene oxide (5 to 15 moles) modified silicone (polymerization degree: 3 to 15), sodium alkylbenzene sulfonate and the like. When the surface tension of the 1% aqueous solution exceeds 40 mN / m or when the sedimentation velocity exceeds 30 seconds and both cases, the absorption performance of the absorbent composition to blood becomes insufficient.

The ratio of the water-absorbing resin (A) to the surfactant (B) is usually 100: (0.05 to 5), preferably 100: (0.1 to 3), particularly preferably 10: (mass basis).
0: (0.2 to 2). When the ratio of the surfactant (B) is less than 0.05, the effect of improving the blood absorption properties becomes insufficient. On the other hand, when the ratio of (B) exceeds 5, the effect of improving the blood absorption characteristics is recognized, but the blood absorption amount decreases. Furthermore, the powder fluidity (for example, angle of repose, spatula angle) of the obtained absorbent composition deteriorates.

In the present invention, by further using a carboxylic acid (C) having 10 or less carbon atoms, blocking of blood and formation of momako are prevented, and an absorbent composition having more excellent blood absorption properties can be obtained. it can. The carboxylic acids (C) having 10 or less carbon atoms are monovalent to 3
Or higher carboxylic acids and / or salts thereof can be used, and specific examples thereof include the following. (I) a saturated carboxylic acid having 1 to 10 or more carbon atoms, preferably 3 to 8 carbon atoms (for example, formic acid, acetic acid, propionic acid, butyric acid, amylic acid, succinic acid, benzoic acid, etc.); A hydroxyl group-containing carboxylic acid having 3 to 10 or more, preferably 3 to 6 carbon atoms (eg, lactic acid, malic acid, tartaric acid, glycolic acid, citric acid, p-hydroxybenzoic acid, salicylic acid, 3-hydroxypyrropionic acid) (III) a halogen-containing carboxylic acid having 3 to 10 or more carbon atoms, preferably 3 to 6 carbon atoms (eg, 2-chloropropionic acid, P-chlorobenzoic acid, etc.); (IV) 2 carbon atoms -10 or more, preferably an amino group-containing carboxylic acid having 2 to 6 carbon atoms (for example, glycine,
(V) unsaturated carboxylic acids having 4 to 10 or more carbon atoms, preferably 4 to 6 carbon atoms (e.g., maleic acid, maleic anhydride, fumaric acid, itaconic acid, etc.) , (V)
Is added after the polymerization of the water-soluble monomer in the production of (A)); and the salts of these (I) to (V) (alkali metal salts such as sodium and potassium, ammonium salts, Organic amine salts such as tributylamine salt), and one or more of these can be used.

Of these, preferred are (I) to (I)
I) and salts thereof, more preferably those having no reactivity with the water absorbent resin (A) and having an acid dissociation index (pKa) of 3
To 6 organic carboxylic acids, and specific examples thereof include propionic acid, succinic acid, benzoic acid, lactic acid, malic acid, tartaric acid, glycolic acid, salicylic acid, and salts thereof. Particularly preferred are succinic acid, lactic acid, malic acid,
Tartaric acid, salicylic acid, glycolic acid and the like, and among them, lactic acid, tartaric acid, glycolic acid and salicylic acid, among which are hydroxyl group-containing carboxylic acids. The acid dissociation index (pKa) is defined as follows. When AH is an acid, the formula AH → / ← A ⁻ + H ⁺
And the acid dissociation index pKa =
-LogKa [mol dm ^-3 ] / [mol dm ^-3 ]. Here, Ka = [A ⁻ ] · [H ⁺ ] / [AH],
[] Indicates the molar concentration. Incidentally, Ka can be determined by potentiometric titration. Specific values of pKa include, for example, lactic acid: 3.8, glycolic acid: 3.9, tartaric acid: 4.2, and propionic acid: 4.9.

The ratio of the water-absorbent resin (A) to the carboxylic acid (C) is usually 100: (0.1 to 10) on a mass basis,
Preferably 100: (0.2 to 7), particularly preferably 1
00: (0.5 to 5). When the ratio of (C) is less than 0.1, the effect of preventing gel blocking and mamako formation on blood is poor, and when the ratio of (C) exceeds 10, no further effect of improving blood absorption properties is observed, and It is economical and shows a tendency for absorption performance to decrease.

The absorbent composition can be obtained by mixing the water absorbing resins (A) and (B) or (A), (B) and (C). The method of adding (B), or (B) and (C) to the water-absorbent resin (A) is not particularly limited, and may be added at any point in the final product before the polymerization of (A). I just need. A preferred method is to mix (B) or (B) and (C) with the powder of the water-absorbent resin (A). When (B) and (C) are used together,
(B) and (C) may be added separately, or may be added simultaneously. When the particles of (A) are subjected to surface crosslinking, (B), or (B) and (C) may be added at the time of surface crosslinking, or may be added before, during or after surface crosslinking. In these cases, (B) or (B)
And (C) is a neat liquid or a liquid diluted by dissolving, emulsifying, or dispersing in water and / or a solvent (eg, methanol, ethanol, acetone, etc.), spraying on the powder surface of (A), or (A) Can be uniformly and efficiently mixed by dropping while stirring and mixing. In this case, the average particle size of the powder (A) is not particularly limited, but is usually 100 to 600 μm, and 100 to 85 μm.
What has been pulverized so that the particles in the range of 0 μm become 95% by mass or more can be used. Preferably, the average particle size is from 200 to 500 microns, with particles in the range of from 150 to 850 microns being at least 95% by weight.

The apparatus for mixing (B) or (B) and (C) with (A) is not particularly limited as long as it can uniformly spray and / or mix.
Cylindrical mixer, screw mixer, turbulizer, Nauter mixer, V mixer, ribbon mixer,
Examples include a double-arm kneader, a universal mixer, a fluidized-bed mixer, an airflow mixer, a rotating disk mixer, a conical blender, a roll mixer, and the like, and combinations thereof.
Although the action mechanism of the addition of these specific (B) or the addition of (B) and (C) is not clear, it is presumed to be a synergistic effect of the following actions. (1) (B) improves blood diffusibility by lowering the surface tension of blood; (2) (C) improves blood absorbency by preventing aggregation and deposition of blood cell components and the like; (3) (B) or (B) and (C) improve the absorbency by lowering the viscosity of the liquid to be absorbed by destroying blood cell components, etc. (4) (B) is the blood (A) Promotes internal penetration. Further, by controlling the water content in the absorbent composition to 3 to 20%, the above action is further promoted and the action of promoting the penetration of blood into (A) is obtained.

In the absorbent composition of the present invention, inorganic particles (eg, silica, zeolite, talc, calcium carbonate, shirasu balloon, etc.), antibacterial agents (eg, , Quaternary ammonium salt compounds, chlorhexidine compounds, metal salt antibacterial agents, etc.), preservatives, fragrances, deodorants, residual monomer reducing agents (eg, sodium sulfite, hydrogen peroxide, etc.), coloring agents, antioxidants Agents and the like can be added. These addition amounts are usually 10% by mass or less, preferably 5% by mass or less, based on the total mass of (A) and (B) or (A), (B) and (C).

The absorption amount of the absorbent composition of the present invention in physiological saline is almost the same as (B) or (A) before mixing (B) and (C), and the absorption amount is 30%. ~ 70
g / g. Preferably it is 35 to 65 g / g, more preferably 40 to 60 g / g. On the other hand, the absorption amount to blood is 20 g / g or more, preferably 22 to 50 g.
/ G. In addition, the water retention capacity for blood is 12 g / g or more, preferably 15 g / g or more, and more preferably 20 g / g.
/ G or more. The first absorption rate for blood is 60
Seconds or less, preferably 45 seconds or less, and more preferably 35 seconds or less. The second absorption rate for blood is 5
00 seconds or less, preferably 450 seconds or less, more preferably 400 seconds or less.

The amount of water absorbed, the amount of water retained, and the rate of absorption are determined by the following methods. [Measurement method of blood absorption amount]: Tea bag made of 250 mesh nylon net (length 20 cm, width 10 cm)
1.00 g of the absorbent composition, and 60 ml in 300 ml of horse blood (containing 3.8% citric acid; manufactured by Japan Lamb).
After immersion for a minute, the suspension is drained for 15 minutes, and then the increased mass is measured to determine the amount of absorbed blood. [Measurement method of blood water retention amount]: The tea bag containing the blood absorption gel after measuring the blood absorption amount is centrifugally dehydrated at 250 G for 90 seconds, and the increased mass is measured to obtain the blood water retention amount. [Measurement method of blood absorption rate]: 0.5 g of the absorbent composition was uniformly spread on a Petri dish of φ60 mm, and 2.5 g of horse blood (containing 3.8% citric acid; manufactured by Japan Lamb) was spread. Is dropped at the center for 2 seconds, and the time until the absorption is completed (visual confirmation that blood is absorbed) is measured and defined as the first absorption speed. Ten minutes after the end of the first measurement of the absorption rate, 2.5 g of horse blood was dropped again, and the time until the absorption was completed was measured to obtain the second absorption rate.

The method for applying the absorbent composition of the present invention to an absorbent article is not particularly limited, and a method for applying a general water-absorbent resin (A) can be employed. For example, (1) the absorbent composition of the present invention is mixed with a fibrous material (for example, fluff pulp, synthetic fiber, or a combination thereof) while being continuously charged with a screw feeder or the like, and pressed under pressure if necessary. And (2) a method in which the absorbent composition is spread on a fibrous material or water-absorbing paper, and another fibrous material or water-absorbing paper is placed thereon, sandwiched in layers, and embossed if necessary.

As an example of an absorbent article, not only the above-mentioned sheet-like material but also this sheet-like absorbent article (absorbent) may be used with a water-permeable surface material (for example, nonwoven fabric, mesh sheet, etc.), a water-impermeable material. Examples include a form sandwiched between sheet materials (eg, a polyethylene film and a polyethylene laminated nonwoven fabric), a form in which these are fixed with an adhesive, and a form in which gathers and tapes are arranged. Fibrous material used for these absorbent articles, water-absorbing paper, water-permeable surface material,
The water-impermeable sheet material, the material such as adhesive, the composition, the basis weight, the thickness, the type, and the size of the obtained absorbent article are not particularly limited, and may be the same as in the case of a normal water-absorbent resin. . In addition, the amount of the absorbent composition of the present invention, the method of use, the method of applying the absorbent composition to an absorbent article, the equipment necessary for application, and the like may be normal.

More specific examples of the absorbent articles include disposable disposable diapers (such as children's disposable diapers and adult disposable diapers), sanitary napkins, incontinent pads, breast milk pads, and the like.
Examples include hygiene and medical supplies such as surgical underpads, puerperal mats, and dressings for protecting wounds. In addition, various household and industrial absorbent sheets (for example,
Pet urine absorbing sheet, freshness retaining sheet, drip absorbing sheet, paddy rice seedling raising sheet, concrete curing sheet, water running prevention sheet for cables, etc.). Furthermore, for applications where the powdered absorbent composition is applied (for example, soil water retention agents, sludge solidifying agents, solidifying agents such as waste blood and aqueous waste liquid, urine gelling agents, and electrolyte gelling agents for batteries). Can also be suitably used. Preferably, it is particularly useful for applications such as sanitary napkins, surgical underpads, puerperal mats, dressings for protecting wounds, drip absorbing sheets, and solidifying agents for waste blood, which are used for the purpose of absorbing blood.

[0030]

The present invention will be further described with reference to the following examples and comparative examples, but the present invention is not limited to these examples. Example 1 77 g of sodium acrylate, 22.7 g of acrylic acid, 0.3 g of N, N'-methylenebisacrylamide and 295 of deionized water were placed in a 1-liter glass reaction vessel.
g, and the temperature of the contents was kept at 3 ° C. while stirring and mixing. Introduce nitrogen into the contents to reduce dissolved oxygen by 0.3pp
m, 1 g of a 1% aqueous solution of hydrogen peroxide, 1.2 g of a 0.2% aqueous solution of ascorbic acid, and 2.8 g of a 2% aqueous solution of 2,2′-azobisamidinopropane dihydrochloride are added and mixed. Then, polymerization was started, and polymerization was carried out for about 5 hours to obtain a hydrogel polymer (A1).
(A1) was shredded to a size of about 2 to 5 mm using an internal mixer, 1 g of a 10% aqueous solution of ethylene glycol diglycidyl ether was added, and the mixture was uniformly mixed using an internal mixer. It was dried with a ventilated band dryer (manufactured by Inoue Metal Industry) at 0 m / sec. The obtained dried product was pulverized and adjusted to a particle size of 850 to 150 μm to obtain a water-absorbent resin powder (AD1). 100 g of this powder (AD1) was put into an air-flow type mixer, and 4.5 mol of ethylene oxide laurate adduct (1%
(Surface tension of aqueous solution: 27 mN / m, sedimentation speed by campus method: 3 seconds) (B1) 0.5 g is added and mixed. Further, the mixture is uniformly mixed by stirring with a Nauter-type mixer for 30 minutes, and the average particle diameter is 430 microns.
I got Table 1 shows the performance evaluation results of the absorbent composition (1).

Example 2 While stirring 100 g of the water-absorbent resin powder (AD1) of Example 1 at a high speed, a 10% water / methanol mixed solution of ethylene glycol diglycidyl ether (water / methanol = 3)
(0/70) was added and mixed, and then heat-crosslinked at 140 ° C. for 30 minutes to obtain a surface-crosslinkable water-absorbent resin powder (AS1). 100 g of this powder (AS1) is put into an air-flow mixer, and a 10% aqueous solution of (B1) 5 is stirred.
The powders (AS1) and (B1) are mixed by atomizing g and spraying. Further, the mixture was stirred with a Nauter mixer for 30 minutes and mixed uniformly to obtain an absorbent composition (2) having an average particle diameter of 390 microns. Table 1 shows the performance evaluation results of the absorbent composition (2).

Example 3 An absorbent composition (3) was prepared in the same manner as in Example 2 except that 10 g of a 10% aqueous solution of (B1) was used instead of 5 g of a 10% aqueous solution of (B1). Obtained. Table 1 shows the performance evaluation results of the absorbent composition (3).

Example 4 An absorbent composition (4) was prepared in the same manner as in Example 2 except that 3 g of a 10% aqueous solution of (B1) was used instead of 5 g of a 10% aqueous solution of (B1). Obtained. Table 1 shows the performance evaluation results of the absorbent composition (4).

Example 5 In Example 2, instead of 5 g of a 10% aqueous solution of (B1), 7 mol of adduct of isotetracosa alcohol ethylene oxide (surface tension of 1% aqueous solution: 27 mN / m, sedimentation velocity by campus method) : 2 seconds) An absorbent composition (5) was obtained in the same manner as in Example 2 except that the same amount of the (B2) 10% aqueous solution was used. Table 1 shows the performance evaluation results of the absorbent composition (5).

Example 6 In Example 2, a polyether modified silicone oil (SH-3746 manufactured by Toray Silicone Co., Ltd., surface tension of 1% aqueous solution: 24 m) was used instead of 5 g of a 20% aqueous solution of (B1).
N / m, sedimentation speed in the campus method: 2 seconds) An absorbent composition (6) was obtained in the same manner as in Example 2 except that 0.5 g of (B3) was used. Table 1 shows the performance evaluation results of the absorbent composition (6).

Example 7 In Example 2, 2.5 g of a 10% aqueous solution of (B1) and lactic acid (C1) 3 were used instead of 5 g of a 10% aqueous solution of (B1).
Except for using g, the absorbent composition (7) was obtained in the same manner as in Example 2. Table 1 shows the performance evaluation results of the absorbent composition (7).

Example 8 In Example 5, 2.5 g of a 10% aqueous solution of (B2) and lactic acid (C1) 3 were replaced with 5 g of a 10% aqueous solution of (B2).
Except using g, it carried out similarly to Example 5, and obtained the absorbent composition (8). Table 1 shows the performance evaluation results of the absorbent composition (8).

Example 9 In Example 6, (B3) was changed to (B3) instead of 0.5 g.
3) Example 6 except that 0.25 g and 3 g of (C1) were used.
In the same manner as in the above, an absorbent composition (9) was obtained. Table 1 shows the performance evaluation results of the absorbent composition (9).

Example 10 An absorbent composition (10) was obtained in the same manner as in Example 9, except that the same amount of glycolic acid (C2) was used instead of 3 g of (C1). Table 1 shows the performance evaluation results of the absorbent composition (10).

Example 11 The hydrogel polymer (A1) obtained in Example 1 was chopped to a size of about 2 to 5 mm with an internal mixer, and then a 10% aqueous solution of ethylene glycol diglycidyl ether was added to 1 part.
g and knead it uniformly with an internal mixer.
Further, 0.5 g of (B3) was added, and the mixture was again uniformly mixed with the intimal mixer. 130 ° C, wind speed 2.0
It dried with the ventilation type band dryer of the conditions of m / sec. The obtained dried product is pulverized, adjusted to a particle size of 850 to 150 μm, and an absorbent composition having an average particle size of 400 μm (11).
I got Table 1 shows the performance evaluation results of the absorbent composition (11).

Example 12 While stirring 100 g of the water-absorbing agent composition (11) obtained in Example 11, a 10% water / methanol mixed solution (water / methanol = 30/70) of ethylene glycol diglycidyl ether was added thereto. After adding and mixing 2 g, the mixture was heat-crosslinked at 140 ° C. for 30 minutes to obtain a surface-crosslinkable water-absorbent resin powder (AS2). This powder (AS2) was put into an air-flow type mixer, and 3 g of (C1) was added under stirring and (A1).
S2) and (C1) are mixed. Further, the mixture was stirred with a Nauter mixer for 30 minutes and uniformly mixed to obtain an absorbent composition (12) having an average particle diameter of 385 μm. Table 1 shows the performance evaluation results of the absorbent composition (12).

Example 13 Acrylic acid was placed in a 1-liter glass reaction vessel.
7 g, pentaerythritol triallyl ether 0.3
g and 241 g of deionized water, and the temperature of the contents was kept at 3 ° C. while stirring and mixing. After flowing nitrogen into the contents to reduce the amount of dissolved oxygen to 0.3 ppm or less, 1 g of a 1% aqueous solution of hydrogen peroxide, 1.2 g of a 0.2% aqueous solution of ascorbic acid, and 2,2′-azobisamidinopropane 2.8 g of a 2% aqueous solution of dihydrochloride was added and mixed to start polymerization, and polymerization was carried out for about 5 hours to obtain an acid-type hydrogel polymer. While shredding the acid-type hydrogel polymer into a size of about 2 to 5 mm with an internal mixer, 109 g of a 30% aqueous sodium hydroxide solution was added and kneaded to obtain about 72 mol% of the carboxylic acid groups. To obtain a hydrogel polymer (A2) neutralized. (A2)
1 g of a 10% aqueous solution of ethylene glycol diglycidyl ether was added to the mixture, and the mixture was uniformly mixed with an internal mixer, and then dried with a ventilated band dryer at 150 ° C. and a wind speed of 2.0 m / sec. The obtained dried product is pulverized, and 850
Water absorbent resin powder (AD
3) was obtained. This powder (AD3) was subjected to surface crosslinking in the same manner as in Example 2 to obtain a surface-crosslinked type water-absorbing resin (AS).
2) was obtained. (AS2) By spraying 5 g of a 10% aqueous solution of (B1) into 100 g of (AS2) in the form of a mist, (AS2)
And (B1). Furthermore, it is 30 with Nauta type mixer.
The mixture was stirred for 1 minute and mixed uniformly to obtain an absorbent composition (13) having an average particle diameter of 420 microns. Absorbent composition (13)
Table 1 shows the performance evaluation results.

Example 14 In Example 13, 2.5 g of a 10% aqueous solution of (B1) and 3 g of (C1) were used instead of 5 g of a 10% aqueous solution of (B1).
Except for using, an absorbent composition (14) was obtained in the same manner as in Example 13. Table 1 shows the performance evaluation results of the absorbent composition (14).

Example 15 In Example 13, 2.5 g of a 10% aqueous solution of (B1) and 3 g of (C2) were used instead of 5 g of a 10% aqueous solution of (B1).
Absorbent composition (15) was obtained in the same manner as in Example 13 except for using. Table 1 shows the performance evaluation results of the absorbent composition (15).

Comparative Example 1 The water-absorbent resin powder (AD1) obtained in Example 1 was used as a comparative absorbent (a), and the performance evaluation results are also shown in Table 1.

Comparative Example 2 The surface-crosslinked water-absorbent resin powder (AS) obtained in Example 2
1) was taken as comparative absorbent (b), and the performance evaluation results are also shown in Table 1.

Comparative Example 3 The water absorbent resin powder (AD3) obtained in Example 13 was used as a comparative absorbent (c), and the performance evaluation results are also shown in Table 1.

Comparative Example 4 The surface-crosslinked type water-absorbing resin (AS) obtained in Example 13
2) was used as a comparative absorbent (d), and the performance evaluation results are also shown in Table 1.

Comparative Example 5 100 g of the water-absorbent resin powder (AS1) obtained in Example 2
While stirring at a high speed, 25% aqueous 10% sodium alum solution.
By adding g, a comparative absorbent (e) having a water content of 26.8% was obtained. Table 1 also shows the performance evaluation results of the comparative absorbent (e).

Comparative Example 6 In Example 3, 50 g of nonylphenol ethylene oxide adduct (surface tension of a 1% aqueous solution: 50 mN / m, sedimentation rate by campus method: 380) was used instead of 10 g of a 10% aqueous solution of (B1). Second Comparative Example) A comparative absorbent (f) was prepared in the same manner as in Example 3 except that the same amount of a 10% aqueous solution was used.
I got Table 1 shows the performance evaluation results of the comparative absorbent (f).
It is described together.

Comparative Example 7 In Example 3, a 10% aqueous solution of (B1) was replaced with 10 g of a pluronic-type polyoxyethylene / polyoxypropylene copolymer (Newpol) as exemplified in JP-A-54-70694. PE-62; manufactured by Sanyo Chemical Industries; 1
(Aqueous solution (g)) was obtained in the same manner as in Example 3 except that the same amount of a 10% aqueous solution having a surface tension of a 45% aqueous solution and a sedimentation rate of 25 seconds in a campus method was used.
Table 1 also shows the performance evaluation results of this comparative absorbent (g).

Comparative Example 8 Comparative Example 8 was carried out in the same manner as in Example 3 except that 1 g of glycerin exemplified in JP-A-6-58952 was used instead of 10 g of the 10% aqueous solution of (B1). Agent (h) was obtained. Table 1 also shows the performance evaluation results of the comparative absorbent (h).

[0053]

[Table 1]

[0054]

The absorbent composition and the absorbent article of the present invention have the following features and effects. The absorbent composition of the present invention is excellent in blood absorption characteristics (absorption amount, water retention amount). In particular, it exhibits excellent blood water retention, blood absorption rate and repetitive absorption performance not found in conventional water absorbent resins. Aggregation and deposition due to blood cell components and the like in blood can be prevented. Blood diffusivity, non-gel blocking properties, and permeability into the resin are significantly improved. An absorbent article using the absorbent composition of the present invention exhibits excellent blood absorption characteristics. By a simple method of adding a surfactant or a surfactant and an organic carboxylic acid and / or a salt thereof to a water-absorbing resin and mixing them, the absorption characteristics to blood can be improved. Accordingly, the absorbent composition and absorbent article of the present invention are used for the purpose of absorbing blood, for example, sanitary napkins, surgical underpads, puerperal mats, wound protecting dressings, drip absorbing sheets, It is particularly useful as a solidifying agent for waste blood.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08K 5/103 C08K 5/42 5/17 C08L 101/14 5/42 (C08L 101/14 C08L 101/14 71:00 // (C08L 101/14 83:12) 71:00 A61F 13/18 307B 83:12) (72) Inventor Kenji Tanaka 11-11 Hitotsubashi Nohonmachi, Higashiyama-ku, Kyoto Sanyo Kasei Kogyo Co., Ltd. Terms (reference) 4C003 AA24 4F070 AA29 AA36 AB13 AC38 AC40 AC43 AC92 AE14 FA01 FB05 FB09 FC03 FC07 4G066 AA13D AB06A AB06D AB07A AB07D AB10D AB13D AB21D AB23A AC17B AC22D AC28D AC35B AE06 FA1A1BA36 FA36A01BA36 BF021 BG011 BG031 BG071 BG101 BG131 BH021 BJ001 BQ001 CH022 CP182 EF037 EF057 EF077 EF097 EH046 EH156 EL147 EN006 EN117 EN136 EP016 EV256 EW046 FD010 FD312 FD316

Claims (10)

[Claims] 1. A composition comprising a water-absorbent resin (A) and the following surfactant (B), wherein the ratio of (A) to (B) is 1 based on mass.
00: (0.05-5), and the first time the horse blood absorption rate by the following blood absorption rate measurement method is 60 seconds or less,
The absorbent composition, wherein the second time is 500 seconds or less. [Surfactant (B)] The surface tension of a 1% aqueous solution at 25 ° C. is 40 mN / m or less, and the sedimentation rate of wool felt by the campus method of a 1% aqueous solution at 25 ° C. is 30 seconds or less. Surfactant. [Measurement method of blood absorption rate]: 0.5 g of the absorbent composition was evenly spread on a Petri dish of φ60 mm, and 2.5 g of horse blood was dropped at the center in 2 seconds until the absorption was completed. The time is measured and used as the first absorption rate. 1
Ten minutes after the end of the second measurement of the absorption rate, 2.5 g of horse blood is dropped again, and the time until the absorption is completed is measured to obtain the second absorption rate. 2. The absorbent composition according to claim 1, wherein the blood absorption rate is 45 seconds or less at the first time and 450 seconds or less at the second time. 3. The method according to claim 1, wherein (B) is at least one member selected from the group consisting of polyoxyalkylene aliphatic esters, polyoxyalkylene modified silicones, sorbitan fatty acid esters and alkylene oxide adducts thereof, and sulfonates. Or the absorbent composition according to 2. 4. The composition according to claim 1, further comprising a carboxylic acid (C) having 10 or less carbon atoms, wherein the ratio of (A) to (C) is 100: (0.1 to 10) on a mass basis. 4. The absorbent composition according to any one of 3. 5. The method according to claim 1, wherein said (C) is a saturated carboxylic acid having 1 to 10 carbon atoms, a carboxylic acid having 3 to 10 carbon atoms, or a carboxylic acid having halogen, a 2 to 10 carbon atoms having an amino group, The absorbent composition according to any one of claims 1 to 4, wherein the absorbent composition is at least one selected from the group consisting of Formulas 4 to 10 unsaturated carboxylic acids and salts thereof. 6. The absorbent composition according to claim 1, wherein (C) is a carboxylic acid having an acid dissociation index of 3 to 6. 7. The absorbent composition according to claim 1, wherein (A) is a surface-crosslinked water-absorbent resin. 8. The absorbent composition according to claim 1, wherein the water retention capacity for blood is 20 g / g or more. 9. (B) or (B) and (C),
Alternatively, a liquid obtained by diluting them with water and / or a solvent is mixed with the particles of (A) obtained by drying and pulverizing the hydrogel polymer (A) of (A), if necessary, by mixing (A) with stirring. While spraying, dripping or mixing, or (2) (A)
The method for producing an absorbent composition according to any one of claims 1 to 8, wherein when the particles are crosslinked, they are added at the time of (A) or after the surface crosslinking. 10. An absorbent article using the absorbent composition according to claim 1.