JP3060095B2 - Urethane resin composition, water absorbent and moisture absorbent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a urethane resin composition, a water-absorbing material and a moisture-absorbing / desorbing material, and more particularly, to a urethane resin using a water-absorbing resin dispersion having a fine dispersed particle size and good dispersion. The present invention relates to a composition, a water absorbing material and a moisture absorbing and releasing material.

[0002]

2. Description of the Prior Art It is known to use polymer polyols as part of the polyol component for producing polyurethane resins. For example, JP-A-54-13359
No. 9 discloses the use of a hydrophilic vinyl monomer for producing such a polymer polyol. However, although a polymer polyol using a non-hydrophilic vinyl monomer such as styrene or acrylonitrile has been demonstrated to be a stable dispersion, it is unknown when a hydrophilic vinyl monomer is used. It is. On the other hand, a dispersion obtained by mixing a water absorbent resin powder with a high molecular weight polyol is also known.

[0003]

However, Japanese Patent Application Laid-Open No.
In the production method described in 133335, when a hydrophilic vinyl monomer is used, a stable dispersion cannot be obtained. In addition, a mere mixture of a high molecular weight polyol and a water-absorbent resin powder not only has a detrimental effect that the water-absorbent resin is easily aggregated and sedimented, but also has a large water-absorbent resin particle diameter, so that the water-absorbing rate and the moisture-absorbing / desorbing rate are low. There is also the problem of being slow.

[0004]

The present inventors have repeatedly studied a urethane resin composition and a water-absorbing material which are easy to produce, have a fine water-absorbent resin particle diameter, and are well dispersed, and as a result, have found that the present invention has been made. Reached. That is, the present invention comprises a urethane resin (U) obtained by reacting a polyoxyalkylene compound (A) and a polyisocyanate compound (P) constituting a dispersion medium in the following water-absorbing spore dispersion (D). , (U) in which the water-absorbent resin (B) or its hydrogel is dispersed. Water-absorbent resin dispersion (D): One or more vinyl monomers (1) having a carboxyl group or a sulfonic acid group in the polyoxyalkylene compound (A) in the presence of water, a copolymerizable crosslinking agent (2) ) And, if necessary, a water-absorbent resin (B) formed by polymerizing another vinyl monomer (3), or a water-absorbent resin dispersion obtained by dispersing the water-absorbent gel thereof in (A). The present invention also relates to a polyoxyalkylene compound (A) comprising, in the presence of water, one or more vinyl monomers having a carboxyl group or a sulfonic acid group (1), a copolymerizable crosslinking agent (2), Thus, a water-absorbent resin (B) formed by polymerization of another vinyl monomer (3) or a water-absorbent gel thereof is dispersed in (A). Further, the present invention comprises mixing the following water-absorbent resin dispersion (D) and a polyisocyanate compound (P),
This is a method for producing a urethane resin composition in which a water-absorbing spore (B) or a hydrogel thereof is dispersed in a urethane resin composition (U) by a urethanization reaction. Water-absorbent resin dispersion (D): One or more vinyl monomers (1) having a carboxyl group or a sulfonic acid group in the polyoxyalkylene compound (A) in the presence of water, a copolymerizable crosslinking agent (2) ) And, if necessary, a water-absorbent resin (B) formed by polymerizing another vinyl monomer (3), or a water-absorbent resin dispersion obtained by dispersing the water-absorbent gel thereof in (A).

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The water-absorbent resin dispersion (D) used in the present invention is obtained by dispersing a water-absorbent resin (B) polymerized in (A) or a water-absorbing gel thereof in a polyoxyalkylene compound (A). It is a water-absorbent resin dispersion obtained.

The polyoxyalkylene compound (A) includes polyoxyalkylene mono- or polyol. Further, there may be mentioned etherified products and esterified products in which the hydroxyl group of the mono- or polyol is blocked with an alcohol or a carboxylic acid.

As the polyoxyalkylene monool, compounds having one active hydrogen atom (for example, C1 to C1)
C20 aliphatic, cycloaliphatic or araliphatic alcohols;
Compounds having a structure in which an alkylene oxide is added to monohydric phenols, dialkylamines, morpholine, and the like.

The polyoxyalkylene polyol includes compounds having at least 2 (preferably 2 to 8) active hydrogen atoms (eg, polyhydric alcohols, polyphenols, amines, polycarboxylic acids, phosphoric acids, etc.). Compounds having a structure to which an alkylene oxide is added and mixtures thereof are given. Preferred among these are polyhydric alcohols.

Examples of the polyhydric alcohol include dihydric to octahydric alcohols. Examples of the dihydric alcohol include ethylene glycol, diethylene glycol, propylene glycol, 1,3- or 1,4-butanediol,
Alkylene glycols such as 6-hexanediol and neopentyl glycol; and cyclohexanediols, kyrylene glycols and diols having a cyclic group described in JP-B No. 45-1474; and trihydric alcohols include glycerin and trimethylolpropane. , Trimethylolethane, hexanetriol, triethanolamine; tetrahydric alcohols include pentaerythritol, methyleneglycoside, diglycerin; pentahydric or higher alcohols include
Pentitol such as adonitol, arabitol, xylitol, sorbitol, mannitol, ibitol,
Hexitols such as talitol and dulcitol; saccharides such as monosaccharides such as glucose, mannose, fructose and sorbose; oligosaccharides such as sucrose, crehalose, lactose and raffinose; ethylene glycol;
Glycols such as propylene glycol, glycerin,
Glycosides of trimethylolpropane and hexanetriol; polyglycerins such as triglycerin and tetraglycerin; polypentaerythritol such as dipentaerythritol and tripentaerythritol; and tetrakis (hydroxymethyl) cyclohexanol.

Examples of polyhydric phenols include monocyclic polyhydric phenols such as pyrogallol, hydroquinone and phloroglucin; bisphenols such as bisphenol A and bisphenolsulfone; condensates of phenol and formaldehyde (novolak), for example, described in US Pat. No. 3,265,641. And the like.

The amines include ammonia, aliphatic amines, alicyclic amines, heterocyclic amines and aromatic amines. As the aliphatic amine, mono-, di-
And alkanolamines such as tri-ethanolamine, isopropanolamine and amine ethylethanolamine; C1-C20 alkylamines;
6, alkylenediamines such as ethylenediamine, propylenediamine, and hexamethylenediamine; and polyalkyleneamines such as diethylenetriamine and triethylenetetramine. As the alicyclic amine, isophorone diamine, cyclohexylene diamine,
And dicyclohexylmethanediamine. Examples of the heterocyclic amine include aminoethylpiperazine and others described in JP-B-55-21044. Examples of the aromatic amine include aniline, phenylenediamine, diaminotoluene, xylylenediamine, methylenedianiline, and diphenyletherdiamine.

As the alkylene oxide (hereinafter abbreviated as AO) to be added to the active hydrogen atom-containing compound, ethylene oxide and propylene oxide (hereinafter abbreviated as EO and PO), 1,2-, 1,3-, 1,1,2- 4-
Or 2,3-butylene oxide, styrene oxide, and the like, and combinations thereof. Preferred are propylene oxide and combinations of ethylene oxide and propylene oxide. The form of addition of the alkylene oxide is not particularly limited.
More than one kind of co-addition may be used, for example, block addition or random addition, and other addition modes described below. PO-AO added in order (tip) PO-AO-PO-AO added (balanced) AO-PO-AO added PO-AO-PO added Block adducts such as those (active secondary) Random adducts in which PO and AO are mixed and added In the order described in JP-A-57-209920, added in the order described in JP-A-53-13700 Random-block adducts such as those

Examples of etherified polyoxyalkylene monools include methyl ether, isopropyl ether and phenyl ether. Examples of the esterified product of the polyoxyalkylene monol include a methyl ester and a phenyl ester. Examples of etherified polyoxyalkylene polyols include dimethyl ether, diisopropyl ether and diphenyl ether. Examples of the esterified product of the polyoxyalkylene polyol include a dimethyl ester and a diphenyl ester.

In the present invention, together with (A), a polyester polyol, polybutadiene polyol, acrylic polyol, low molecular polyol (for example, the above-mentioned polyhydric alcohol, preferably a liquid at room temperature) or a combination thereof may be used.

The molecular weight of (A) is usually from 100 to 10,000.
0, preferably 500 to 50,000, more preferably 1,000 to 20,000. The polyoxyalkylene polyol has a hydroxyl value of usually from 5 to 280, preferably from 1 to 280.
Those having 0 to 200, more preferably 20 to 150 can be used. Further, the molecular weight per hydroxyl value is usually from 200 to 10,000, preferably from 280 to 550.
0, more preferably 400 to 2500.

The water-absorbent resin (B) is a polyoxyalkylene compound (A) comprising at least one vinyl monomer (1) having a carboxyl group or a sulfonic acid group in the presence of water, a copolymerizable crosslinking agent It is formed by polymerizing (2) and optionally another vinyl monomer (3).

Examples of the vinyl monomer having a carboxyl group (1) include (meth) acrylic acid, crotonic acid, sorbic acid, maleic acid, itaconic acid, cinnamic acid, and acid anhydrides thereof.

Examples of the vinyl monomer having a sulfonic acid group (1) include aliphatic or aromatic vinyl sulfonic acids [vinyl sulfonic acid, allyl sulfonic acid, vinyl toluene sulfonic acid, styrene sulfonic acid, etc.];
Acrylic sulfonic acid [sulfoethyl (meth) acrylate, sulfopropyl (meth) acrylate]; (meth) acrylamide sulfonic acid [2-acrylamide-
2-methylpropanesulfonic acid and the like].

The vinyl monomer (1) may be used as a salt of the carboxylic acid and the sulfonic acid. These salts include alkali metal salts (salts such as sodium, potassium and lithium) and alkaline earth metal salts (calcium,
Salts such as magnesium), ammonium salts and amine salts (salts of alkylamines such as methylamine and trimethylamine; salts of alkanolamines such as triethanolamine and diethanolamine). Preferred among these are alkali metal salts,
Particularly, sodium salts and potassium salts are preferred.

As the vinyl monomer (1), those exemplified above may be used alone or in combination of two or more. Preferred are vinyl monomers having a carboxyl group.

The copolymerizable crosslinking agent (2) includes (2-
1) a compound having at least two radically polymerizable double bonds; and (2-2) a compound having one radically polymerizable double bond and having a functional group (carboxyl) in a vinyl monomer (b) molecule Group, a sulfonic acid group, a hydroxyl group, and an ammonium group). Preferred is the compound of (2-1).

The following are examples of the compound (2-1). Bis (meth) acrylamide; N, N-alkylene (c1-c6) bis (meth) acrylamide (for example, N, N-methylenebisacrylamide). Polyesters of polyols or polyepoxides with unsaturated mono- or polycarboxylic acids, such as those derived from ethylene glycol, trimethylolpropane, glycerin, polyoxyethylene glycol, polyoxypropylene glycol or cyclohexene diepoxide and (meth) acrylic acid or maleic acid Ruji
Or tri- (meth) acrylate and di- or trimaleate. Carbamyl ester: polyisocyanate [tolylene diisocyanate, hexamethylene diisocyanate,
4,4'-diphenylmethane diisocyanate and N
A carbamyl ester obtained by reacting a CO group-containing prepolymer (obtained by reacting the above polyisocyanate with an active hydrogen atom-containing compound) and hydroxyethyl (meth) acrylate. Polyvinyl compounds: divinylbenzene, divinyltoluene, divinylxylene, divinylether, divinylketone, trivinylbenzene and the like. Di- or poly- (meth) allyl ether of polyol: poly (meth) allyl ether of polyols [alkylene glycol, glycerin, polyalkylene glycol, polyalkylene polyol, carbohydrate, etc.] (for example, polyethylene glycol diallyl ether,
Allylated starch and allylated cellulose). Polyallyl esters of polycarboxylic acids: diallyl phthalate, diallyl adipate and the like. Esters of unsaturated mono- or polycarboxylic acids with mono (meth) allyl etherified polyols: (meth) acrylates of polyethylene glycol monoallyl ether. Polyallyloxyalkanes: Tetraallyloxyethane

In the compound of (2-2), a group reactive with a carboxyl group, a sulfonic acid group, a hydroxyl group or an ammonium base in the molecule of the vinyl monomer (1) includes a hydroxyl group, an epoxy group and a tertiary amine. Groups.
Examples of the compound (2-2) include a hydroxyl group-containing ethylenically unsaturated compound [such as N-methylol (meth) acrylamide]; an epoxy group-containing ethylenically unsaturated compound [such as glycidyl (meth) acrylate]; and a tertiary amino group. -Containing ethylenically unsaturated compounds [dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, etc.].

As the copolymerizable crosslinking agent (2), in particular, N,
N-methylenebisacrylamide, ethylene glycol diacrylate, trimethylolpropane triacrylate and tetraallyloxyethane are preferred.

The content of the vinyl polymer composed of (1) and (2) in the dispersion (D) is usually 1 to 70%, preferably 5%, based on the weight of (D), from the viewpoint of the stability of dispersibility. ~ 65
%, Particularly preferably 20 to 60%.

The content of (A) in the dispersion (D) is usually from 30 to 99% based on the weight of the dispersion, from the viewpoint of dispersibility.
Preferably 35 to 95%, particularly preferably 40 to 80%
It is.

The amount of water used must be 5 to 50%, preferably 5 to 45%, more preferably 5 to 50% based on the weight of the dispersion (D) from the viewpoint of easy production of the dispersion. Is 10 to 30%.

The amount of the vinyl monomer (1) used is usually 1 to 70% based on the total weight of (A) and all the vinyl monomers, from the viewpoint of handling of the dispersion and absorption capacity. Preferably it is 5 to 60%, more preferably 10 to 55%.

The amount of the copolymerizable crosslinking agent (2) used is usually 0.001% based on the weight of all the vinyl monomers (1), (2) and, if necessary, (3) from the viewpoint of absorption capacity. ~ 20
%, Preferably 0.01 to 10%, particularly preferably 0.1%.
1 to 5%.

Other vinyl monomers (3) used as required include aromatic vinyl monomers (3-1), unsaturated nitriles (3-2) and (meth) acrylic esters (3). -3), olefin (3-4), fluorinated vinyl monomer (3-5), amino group-containing vinyl monomer (3
-6) and both ends vinyl-modified silicon (3-7). Among them, (3-1), (3-2) and (3-3) are preferable from the viewpoint of copolymerizability and dispersion stability. Examples of (3-1) include styrene, α-methylstyrene, hydroxystyrene, chlorostyrene and the like. Examples of (3-2) include acrylonitrile and methacrylonitrile. Examples of (3-3) include alkyl (meth) acrylates having 1 to 30 carbon atoms in the alkyl group and hydroxypolyoxyalkylene ether mono (meth) acrylate.
Examples of the alkyl ester include methyl (meth) acrylate, butyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, and tetradecyl ( Examples thereof include (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, octadecyl (meth) acrylate, eicosyl (meth) acrylate, and docosyl (meth) acrylate.

Examples of (3-4) include ethylene and propylene, (3-5) include perfluorooctylethyl methacrylate, and perfluorooctylethyl acrylate, and (3-6) include diamino Ethyl methacrylate and morpholinoethyl methacrylate are exemplified.

The amount of the other vinyl monomer (3) used is usually 0 to 20%, preferably 0 to 10% based on the weight of all the vinyl monomers (1), (2) and (3). , More preferably 0 to 5%.

The dispersion (D) used in the present invention is:
A solution obtained by mixing (A) and, if necessary, an emulsifier is added dropwise to the aqueous solution or aqueous dispersion of (1), (2) and, if necessary, (3). By irradiating an electron beam, an ultraviolet ray or the like; an aqueous solution or an aqueous dispersion of (1), (2) and, if necessary, (3) is added dropwise to (A), and if necessary, using a radical polymerization catalyst and an emulsifier, An aqueous solution or aqueous dispersion of (1), (2) and, if necessary, (3) is added dropwise to a mixture of (A) and water, using a radical polymerization catalyst and an emulsifier as necessary. (A), a radical polymerization catalyst is optionally present in a dispersion liquid comprising an emulsifier and water, and (1), (2)
And if necessary, (3) can be obtained by dropping the mixture and then performing the same operation as described above.

Examples of the radical polymerization catalyst include azo compounds [azobisisobutyronitrile, azobiscyanovaleric acid, 2,2'-azobis (2-aminodipropane) dihydrochloride, etc.], inorganic peroxides [hydrogen peroxide] ,
Ammonium persulfate, potassium persulfate, sodium persulfate, etc.], organic peroxides [benzoyl peroxide, di-t-
Butyl peroxide, cumene peroxide,
Redox catalysts [reducing agents such as alkali metal sulfites or bisulfites, ammonium sulfite, ammonium bisulfite, ascorbic acid, and alkali metal persulfate]; succinic peroxide, di (2-ethoxyethyl) peroxydicarbonate, etc. Consisting of a combination of an oxidizing agent such as a salt, ammonium persulfate, and peroxide]; and a combination of two or more of these. The amount of the catalyst used is usually 0.0005 to 5%, preferably 0.001 to 2%, based on the total weight of (1), (2) and if necessary (3).

Examples of the emulsifier include nonionic surfactants [lauryl alcohol ethylene oxide adduct, lauric acid ethylene oxide adduct, sorbitan lauric acid monoester, stearylamine ethylene oxide adduct, nonylphenol ethylene oxide adduct, etc.]; Cationic surfactants [lauryl alcohol sulfate, sodium alkylbenzene sulfonate, aerosol OT, dithiophosphate ester salts, etc.]; cationic surfactants [laurylamine acetate, triethanolamine monostearate formate, etc.]; Two or more of them may be used in combination. Preferred are nonionic surfactants. The amount of the emulsifier to be used is generally 0 to 10% by weight, preferably 0.1 to 5% by weight, based on the dispersion.

The urethane resin composition of the present invention is prepared by removing the dispersion (D) from water if necessary, and adding an organic polyisocyanate (P) and, if necessary, a urethane-promoting catalyst, a crosslinking agent, a foaming agent and a foam stabilizer. It is obtained by reacting in the presence of an agent or the like. For this production, one-shot method,
It can be performed by a known method such as a semi-prepolymer method or a prepolymer method. In addition, a foamed or non-foamed water-absorbent polyurethane molded product can be produced by reacting in a closed mold or an open mold using a low-pressure or high-pressure molding device.

As the organic polyisocyanate (P),
Those conventionally used for polyurethane production can be used. As such a polyisocyanate, an aromatic polyisocyanate having 6 to 20 carbon atoms (excluding carbon in the NCO group) (for example, 2,4- and / or 2,6-
-Tolylene diisocyanate (TDI), crude TDI,
2,4′- and / or 4,4′-diphenylmethane diisocyanate (MDI), crude MDI [condensation product of crude diaminophenylmethane} formaldehyde and aromatic amine (aniline) or a mixture thereof: diaminodiphenylmethane and a small amount ( A phosgenated product of a mixture with a trifunctional or higher polyamine (for example, 5 to 20% by weight): polyallyl polyisocyanate (PAPI), etc.]; aliphatic polyisocyanate having 2 to 18 carbon atoms (for example, hexamethylene diisocyanate, lysine diisocyanate, etc.) Alicyclic polyisocyanate having 4 to 15 carbon atoms (eg, isophorone diisocyanate, dicyclohexylmethane diisocyanate);
5 aromatic aliphatic polyisocyanates (eg, xylylene diisocyanate); and modified products of these polyisocyanates (urethane group, carbodiimide group, allophanate group, urea group, buret group, uretdione group, uretonimine group, isocyanurate group, Oxazolidone group-containing modified products); and JP-A-61-7
No. 6517, other polyisocyanates described above;
And mixtures of two or more of these. Preferred among these are the commercially available polyisocyanates such as 2,4- and 2,6-T
DI, and mixtures of these isomers, crude TDI,
4,4′- and 2,4′-MDI, and mixtures of isomers thereof, PAPI also referred to as crude MDI, and urethane groups, carbodiimide groups, allophanate groups, urea groups, and urea groups derived from these polyisocyanates. Modified polyisocyanates containing a let group and an isocyanurate group. In the present invention, the isocyanate index [NCO /
The equivalent ratio of active hydrogen atom-containing groups x 100] is usually 80 to
140, preferably 85 to 120, particularly preferably 9
5 to 115. The polyisocyanurate can also be introduced into the polyurethane with an isocyanate index significantly higher than the above range (e.g. 300 to 1000 or more).

As the urethanization-promoting catalyst, a catalyst usually used for polyurethane reaction [for example, an amine-based catalyst (eg, triethyleneamine, N-ethylmorpholine or the like)
Secondary amines), tin-based catalysts (such as stannous octylate, dibutyltin dilaurate), and other metal catalysts (such as lead octylate). The amount of the catalyst used is about 0.001 to about 5% based on the total weight of the dispersion of the present invention and the organic polyisocyanate.

As a foaming agent, methylene chloride, monofluorotrichloromethane, water and the like can be used. Examples of the foam stabilizer include a silicone surfactant (polysiloxane-polyoxyalkylene copolymer).

Other additives that can be used include known flame retardants, reaction retarders, colorants, internal release agents, antioxidants, antioxidants, plasticizers, bactericides, carbon black, and other fillers. Additives may be mentioned.

The water-absorbent resin (B) dispersed in the urethane resin (U) of the present invention has an average particle size of usually 0.01 to 1
It is 00 μm, preferably 0.05 to 10 μm, particularly preferably 0.1 to 5 μm. Dispersion average particle size is 100μ
m, the water absorption speed becomes slow, and 0.01 μm
If it is less than 30, the problems such as aggregation of the particles in the dispersion (D) occur.

The urethane resin composition of the present invention can be used as it is as a water-absorbing, moisture-absorbing polyurethane resin.

When the urethane resin composition of the present invention is used as a water-absorbing material, the content of the water-absorbing resin (B) in the urethane resin (U) is usually 30% by weight from the viewpoint of dispersibility and absorptivity. The content is at least 70 wt%, preferably at least 33 wt% and at most 65 wt%, particularly preferably at least 35 wt% and at most 60 wt%.

Examples of use when the urethane resin composition of the present invention is used as a water absorbing material include absorbent articles used for sanitary materials such as disposable diapers.

For example, in an absorbent article having a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorber layer provided between the two sheets, the absorbent layer contains the urethane resin composition of the present invention, In this case, a material is used.

When the urethane resin composition and the water-absorbing material of the present invention are used in the absorbent layer of the absorbent article, the shape is not particularly limited, and examples thereof include plate, needle, sphere, chip, and fiber.

When the urethane resin composition of the present invention and a water-absorbing material are used for the absorbent layer of an absorbent article, for example, if the shape is plate-like, the layer of the water-absorbing paper may be formed as a single layer or a plurality of layers, if necessary. Overlaid, a liquid-permeable topsheet or non-woven fabric is placed on these surfaces, a liquid-impermeable backsheet is placed on the back side, and further equipped with gathers, tape for attachment to the human body, etc., it can be finished into a paper diaper etc. . The material and type of the liquid-permeable top sheet, the liquid-impermeable back sheet, the gathers and the mounting tape, and the method for manufacturing the disposable diaper are not particularly limited, and known disposable diapers used in the related art are used. it can.

When the urethane resin composition of the present invention is used as a moisture-absorbing and releasing material, the content of the water-absorbing resin (B) in the urethane resin (U) is usually 1 wt% from the viewpoint of the rate of moisture absorption and desorption and the amount of moisture absorption. And less than 30 wt%, preferably
3 wt% or more and 27 wt% or less, particularly preferably 5 wt%
% Or more and 25 wt% or less.

[0049]

EXAMPLES The present invention will be further described with reference to examples and use examples, but the present invention is not limited to these examples. Parts in Examples and Usage Examples are parts by weight. The compositions of the raw materials used in Synthesis Examples 1 to 8, Examples 1 to 8 and Comparative Examples 1 to 6, Use Examples 1 to 3, and Comparative Use Examples 1 to 4 are as follows. Polyoxyalkylene compound (A): Polyol A1: PO is added to glycerin and then EO
A polyether polyol having a hydroxyl value of 33 (E
O content 13%). Polyol A2: a polyether polyol having a hydroxyl value of 33 obtained by adding PO to glycerin. Polyol A3: a polyether polyol having a hydroxyl value of 55 obtained by adding PO to glycerin. Polyol A4: a polyether polyol having a hydroxyl value of 34 obtained by adding PO to glycerin. Vinyl monomer (1): acrylic acid (manufactured by Nippon Shokubai Kagaku) Copolymerizable crosslinking agent (2): methylenebisacrylamide (manufactured by Nitto Chemical Industry Co., Ltd.) Radical polymerization catalyst: 2,2′-azobis (2- Aminodipropane) dihydrochloride Emulsifier: Sorbitan lauric acid monoester Amine catalyst: Triethylenediamine (DABCO) Tin catalyst: Stanas octoate (T-9) Tin catalyst: Dibutyltin dilaurate (DBTDL) Isocyanate: Tolylene diisocyanate (TDI) −
80) Foam stabilizer: Silicone foam stabilizer ("L-5" manufactured by Nippon Unicar)
20 ") Water-absorbent resin: Sunfresh ST-500TM (manufactured by Sanyo Kasei Kogyo Co., Ltd., starch acrylic acid grafted product) Water-absorbent resin: Sunwet PA-200 (manufactured by Sanyo Kasei Kogyo, crosslinked sodium polyacrylate Water-absorbent resin)

[Volume-Based Particle Diameter Measurement Method] The water-absorbent resin dispersion was diluted with the polyoxyalkylene compound used in the water-absorbent resin dispersion so that the transmittance of the laser beam became 70 to 90%. The particle diameter was measured by a distribution measuring device (laser diffraction / scattering type particle size distribution measuring device LA-700; manufactured by Horiba, Ltd.).

The absorption amount and absorption rate of physiological saline were measured by the following methods. [Absorption] 1 g of a water-absorbing member was placed in a 250-mesh nylon net tea bag, immersed in a large excess of 0.9% physiological saline for 1 hour to absorb, and then pulled up.
Drain for a minute and measure the weight gain. This value was taken as the absorption amount. [Absorptive speed] 1 g of a water-absorbing member is placed in a 250 mesh nylon net tea bag, immersed in a large excess of physiological saline for 2 minutes, pulled up and drained for 15 minutes, and the increased weight is measured. This value was taken as the absorption rate.

[Method of Evaluating Moisture Absorption and Desorption] The polyurethane foam was allowed to stand in a thermo-hygrostat at a humidity of 80% (25 ° C.), and the change over time in water absorption was measured. Then, a humidity of 40% (25
C) in a thermo-hygrostat, and the amount of water discharged was measured. The amount of water absorption and the amount of water discharge are indicated by the amount (g) of water absorbed or discharged per 50,000 cubic centimeters of apparent volume of the polyurethane foam.

The evaluation methods of Use Examples 1 to 3 and Comparative Use Examples 5 were performed by the following methods. [Absorptive speed] An acrylic plate (weight: 0.5 kg) having the same size as the disposable diaper area, centered on a measuring cylinder (inner diameter: 3 cm), is placed on the disposable diaper, and a load of 4.5 kg is placed on the acrylic plate. Put on. 80 in graduated cylinder
ml of artificial urine (colored with blue ink) was poured, and the time until it was absorbed into the disposable diaper was measured to determine the first absorption rate. After 30 minutes, an additional 80 ml of artificial urine is injected, and the second absorption rate is measured. 80 ml after 30 minutes in the same way
, And the third absorption rate is measured.

[Diffusion area] The area where artificial urine was absorbed and spread after the third absorption rate was measured (colored blue).
Was measured and defined as a diffusion area.

[Surface Dryness] After measuring the diffusion area, the feeling of dryness on the surface of the disposable diaper was judged by 10 panelists' finger touch, and evaluated by the following four grades. This average was defined as surface dryness. ◎: Good dry feeling ○: Slightly wet but satisfactory level of dry feeling △: Poor dry feeling and wet state ×: No dry feeling and wet state

[Shape Retention] The disposable diaper was twisted by hand 30 minutes after the third injection of artificial urine, and the shape retention after 5 minutes was visually evaluated and evaluated in the following three steps. ◎: Restored to the original shape. ：: Almost restored to the original shape, satisfactory level. ×: The form is collapsed.

Synthesis Example 1 In a 2 l four-necked flask equipped with a temperature controller, a vacuum stirring blade, a nitrogen inlet and an outlet, the temperature was 25 ° C. at 40 ° C. or lower.
350 parts of an aqueous sodium hydroxide solution and 200 parts of a vinyl monomer (1) ("Acrylic acid" manufactured by Nippon Shokubai Kagaku) are stirred and mixed, and then a copolymerizable crosslinking agent (2) (Nitto Chemical Co., Ltd.
(Methylenebisacrylamide) (0.02 parts) was further added and mixed with stirring to obtain a homogeneous solution (). Also 500ml
Polyoxyalkylene compound (A): glycerin and propylene oxide (P
O) and then ethylene oxide (EO), and a polyether polyol having a hydroxyl value of 34 (EO content: 20%) ("SANNIX KC" manufactured by Sanyo Chemical Industry Co., Ltd.).
-209 ") and 4 parts of an emulsifier (" Emulmin 140 "manufactured by Sanyo Chemical Industry Co., Ltd.) were mixed and stirred to form a uniform solution (). Next, the solution () was continuously charged over 1 hour while stirring the solution () at a temperature of 40 ° C. or lower while blowing into a nitrogen solution to prepare a W / O emulsion. Further, a solution prepared by dissolving 0.02 part of a radical polymerization catalyst (“ADVN” manufactured by Otsuka Chemical Co., Ltd.) in 0.1 part of toluene is added in advance, and the mixture is heated to 50 ° C. with stirring to form a water-absorbent resin dispersion (D1). Synthesized.

Synthesis Example 2 A water-absorbent resin dispersion (D2) was synthesized in the same manner as in Synthesis Example 1 except that the polyoxyalkylene compound was changed to the following compound and the amount was changed as follows in Example 1. Oxyalkylene chain-containing compound: glycerin and PO
And then EO added to the polyether polyol having a hydroxyl value of 50 (EO content: 70%) (“SANIX FA-103” manufactured by Sanyo Chemical Industries, Ltd.) = 600 parts

Synthesis Example 3 In Example 1, the vinyl monomer was replaced with 2-acrylamide-
A water-absorbing dispersion (D3) was synthesized in the same manner as in Example 1 except that 2-methylpropanesulfonic acid was used. Synthesis Example 1
Table 2 shows the particle diameters and viscosities of the dispersions D1 to D3 obtained in Nos. 1 to 3. The value of the particle size in Table 2 indicates a particle size corresponding to 50% of the cumulative distribution of the volume-based particle size distribution.

Synthesis Examples 4 to 8 In a 1 L four-necked flask equipped with a temperature controller, a vacuum stirring blade, a nitrogen inlet and an outlet, at a temperature of 40 ° C. or lower,
Table 1 shows water, sodium hydroxide, vinyl monomer (1), copolymerizable crosslinking agent (2), radical polymerization catalyst and emulsifier.
Was used in the amount described in Table 1. Thereafter, the polyols A1 and A2 used in the amounts shown in Table 1 were gradually added under stirring, and W /
Make an O-type emulsion, then 50-80 ° C under stirring
Polymerizes the vinyl monomer (1) with water-absorbent resin dispersion (D
4-D8) were synthesized. Table 2 shows the particle diameters and viscosities of the dispersions D4 to D8 obtained in Synthesis Examples 4 to 8.

[0061]

[Table 1]

[0062]

[Table 2]

Examples 1 and 2 The dispersions obtained in Synthesis Examples 1 and 2, water, DABCO and L-520 were mixed in the amounts shown in Table 3, and then about 2
The temperature was adjusted to 5 ° C. Next, the amount of T-9 shown in Table 3 was added and mixed for 10 seconds. To the resulting mixture was added TDI-80 at 25 ° C. in the amount shown in Table 3 and mixed for 7 seconds to form polyurethane foams F1 and F2. Table 5 shows the foam characteristics (foam density, 0.9% saline absorption amount, absorption rate) of the obtained polyurethane foam.

Example 3 After the temperature of the dispersion (D3) was adjusted to 25 ° C., the amount of T-9 shown in Table 3 was added and mixed for 10 seconds. TDI-80 in the amount shown in Table 3 at 25 ° C. was added to the obtained mixture, and after mixing for 7 seconds, the obtained urethane resin F3 was applied on a nonwoven fabric with a thickness of 0.1 mm using a bar coater. Table 5 shows the absorption amount and absorption rate of 0.9% physiological saline in the obtained urethane resin.

Examples 4 to 7 Dispersions (D4 to D7), polyol A3, water, DABC
O and L-520 were mixed in the amounts shown in Table 4 and then adjusted to about 25 ° C. Next, the amount of T-9 shown in Table 4 was added and mixed for 10 seconds. The resulting mixture was added at 25 ° C.
The amounts of TDI-80 shown in Table 2 were added and mixed for 7 seconds to prepare polyurethane foams F4 to F7. Table 6 shows the moisture absorption / desorption performance of the obtained polyurethane foam.

Example 8 The dispersion (D8) and the polyol A3 were mixed in the amounts shown in Table 4, and then adjusted to about 25 ° C. Next, the amount of T-9 shown in Table 4 was added and mixed for 10 seconds. To the resulting mixture was added TDI-80 at 25 ° C.
After mixing for 2 seconds, the obtained polyurethane resin F8 was applied on a nonwoven fabric with a thickness of 0.1 mm using a bar coater. Table 6 shows the moisture absorption / desorption performance of the obtained polyurethane resin.

Comparative Examples 1 and 2 The polyoxyalkylene compound (polyol A) used in Synthesis Example 1 was used in the same manner as in Example 1 by using the components shown in Table 3 to obtain Comparative Examples 1 and 2. Polyurethane foams RF1 and RF2 were prepared. Foam properties (foam density, 0.9%
Table 5 shows the amount of physiological saline absorbed and the rate of absorption.

Comparative Example 3 The amount of the water-absorbing resin shown in Table 3 was added to the polyoxyalkylene compound (polyol A) used in Synthesis Example 1, and
Mix for 0 seconds, then adjust the resulting mixture to 25 ° C. The obtained mixture was added at 25 ° C. to the amount of T-9 shown in Table 3.
Was added and mixed for 10 seconds. To the resulting mixture was added TDI-80 in an amount shown in Table 3 at 25 ° C., and after mixing for 7 seconds, the obtained comparative urethane resin RF3 was placed on a nonwoven fabric to a thickness of 0.1 mm.
It was applied with a bar coater at 1 mm. Table 5 shows the absorption amount and absorption rate of 0.9% physiological saline in the obtained urethane resin.

Comparative Examples 4 and 5 The same operations as in Example 4 were carried out using the components shown in Table 4 to produce polyurethane foams RF4 and RF5 of Comparative Examples 4 and 5. Table 6 shows the moisture absorption / desorption performance of the obtained polyurethane foam.

Comparative Example 6 Using the components shown in Table 4, a polyurethane resin RF6 obtained in the same manner as in Example 8 was applied on a nonwoven fabric with a thickness of 0.1 mm by a bar coater. Table 6 shows the moisture absorption / desorption performance of the obtained polyurethane resin.

[0071]

[Table 3]

[0072]

[Table 4]

[0073]

[Table 5]

[0074]

[Table 6]

Use Examples 1 and 2 The polyurethane foams F1 to F3 of the present invention were placed in a size of 14 cm.
(Vertical) x 36cm (horizontal) x 5mm (thickness) cut into rectangles, water-absorbing paper of the same size as the absorber layer is placed above and below each, and the polyethylene sheet used for ordinary paper diapers is backed. Then, model paper diapers P1 and P2 were prepared by disposing a nonwoven fabric on the surface. Table 7 shows the results of evaluating the absorption rate, diffusion area, surface dryness, and shape retention of these model disposable diapers.

Comparative Use Examples 1 and 2 Comparative model disposable diapers RP1 and RP2 were prepared in the same manner as in Use Example 1 using comparative polyurethane foams RF1 and RF2. Table 7 shows the results of evaluating the absorption rate, diffusion area, surface dryness, and shape retention of these model disposable diapers.

Comparative Use Example 3 Sheath-core type composite fiber having polypropylene as a core component and polyethylene as a sheath component (“ES Fiber EAC” manufactured by Chisso Corporation;
30 parts of low melting point component 110 ° C), fluff pulp 70
Part and cross-linked sodium polyacrylate-based water-absorbent resin (“San wet PA-20” manufactured by Sanyo Chemical Industry Co., Ltd.)
0 ") and a mixture obtained by mixing 50 parts with an air-flow type mixing apparatus was uniformly laminated so as to have a basis weight of 400 g / m ² . Next, a comparative model paper diaper RP3 was prepared by performing the same operation as in Use Example 1 on the absorber layer prepared by performing a hot air treatment at 130 ° C. for 3 minutes. Table 7 shows the results of evaluating the absorption rate, diffusion area, surface dryness, and shape retention of these model diapers.
Show.

Comparative Use Example 4 In the absorbent layer prepared in Comparative Use Example 3, the composite fiber /
Ratio of fluff pulp / water-absorbent resin = 30/70/50
Instead of using a composite fiber / fluff pulp / water absorbent resin ratio of 0/100/100, an absorber layer prepared in the same manner as the absorber layer of Comparative Use Example 3 was subjected to the same operation as in Use Example 1. As a result, a comparative model paper diaper RP4 was prepared. Table 7 shows the results of evaluating the absorption rate, diffusion area, surface dryness, and shape retention of these model disposable diapers.

[0079]

[Table 7]

As shown in Table 5, when the urethane resin composition according to the present invention was used as a water-absorbing material, it was found that excellent absorption performance was maintained. Further, as shown in Table 7, when the water-absorbing material is used, for example, as an absorbent layer of an absorbent article, it has an excellent absorption rate, diffusion area, surface dryness, shape retention, and is useful as an absorbent article. I understand.

When the urethane resin composition according to the present invention was used as a moisture absorbing / releasing material, as shown in Table 6, it was found that excellent moisture absorbing / releasing performance was maintained.

[0082]

The urethane resin composition, the water-absorbing material and the moisture-absorbing / desorbing material of the present invention have a water-absorbent resin dispersed uniformly as fine particles having a size of 100 μm or less, and have excellent absorption performance (absorption amount and absorption speed). Has moisture absorption / release performance. Due to the above-mentioned effects, the urethane resin composition, the water-absorbing material and the moisture-absorbing / desorbing material obtained by the present invention are useful for various sanitary materials and water-absorbing articles such as disposable diapers and sanitary articles when used as a water-absorbing material. In addition, it has remarkable utility in applications such as sealing materials, freshness preserving materials for fruits and vegetables, drip absorbents, moisture or humidity adjusting materials, seedling raising sheets for rice, concrete curing sheets, and waterproofing materials for communication cables and optical fiber cables. Demonstrate. Also, when used as a moisture absorbing / releasing material, it is extremely useful for applications such as a humidity control material, a dew condensation preventing material, and a desiccant.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI C08L 35/00 C08L 35/00 41/00 41/00 // (C08G 18/62 101: 00) C08L 75:04 Examiner Fujii Akira (56) References JP-A-54-133599 (JP, A) JP-A-57-150958 (JP, A) JP-A-7-62226 (JP, A) JP-A-3-203921 (JP, A) JP-A-2-88619 (JP, A) JP-A-2-84418 (JP, A) JP-A-63-86712 (JP, A) JP-A-59-120653 (JP, A) JP-A-56-131616 (JP, A) JP-A-56-11941 (JP, A) JP-A-53-138500 (JP, A) Fusayoshi Masuda, “Superabsorbent polymer”, published on November 15, 1987, Kyoritsu Shuppan Co., Ltd. Pp. 37-42 (58) Fields investigated (Int.Cl. ⁷ , DB name) C08L 75/00-75/16 C08G 18/00-18/87

Claims (8)

(57) [Claims] 1. A urethane resin (U) obtained by reacting a polyoxyalkylene compound (A) and a polyisocyanate compound (P) constituting a dispersion medium in the following water absorbent resin dispersion (D), A urethane resin composition in which the water-absorbent resin (B) or a hydrogel thereof is dispersed in U).
Water-absorbent resin dispersion (D): One or more vinyl monomers (1) having a carboxyl group or a sulfonic acid group in the polyoxyalkylene compound (A) in the presence of water, a copolymerizable crosslinking agent (2) ) And, if necessary, a water-absorbent resin (B) formed by polymerizing another vinyl monomer (3), or a water-absorbent resin dispersion obtained by dispersing the water-absorbent gel thereof in (A). 2. The urethane resin composition according to claim 1, wherein the content of the water-absorbent resin (B) in the urethane resin (U) is 1 to 70 wt%. 3. The average particle diameter of (B) dispersed in the urethane resin (U) or its water-absorbing gel is 0.01 to 1
The urethane resin composition according to claim 1 or 2, which has a thickness of 00 µm. 4. The polyurethane foam obtained by a foaming reaction between the polyoxyalkylene compound (A) and the polyisocyanate compound (P) constituting the dispersion medium in the dispersion (D), wherein the urethane resin (U) is used. The urethane resin composition according to any one of claims 1 to 3. 5. A water-absorbing material comprising the urethane resin composition according to claim 1. 6. A moisture absorbing / releasing material comprising the urethane resin composition according to claim 1. 7. In the polyoxyalkylene compound (A), in the presence of water, at least one vinyl monomer having a carboxyl group or a sulfonic acid group (1), a copolymerizable crosslinking agent (2) and, if necessary, A water-absorbent resin (B) formed by polymerizing another vinyl monomer (3) or a water-absorbent resin dispersion (D) obtained by dispersing a water-absorbent gel thereof in (A). 8. The following water-absorbent resin dispersion (D) and a polyisocyanate compound (P) are mixed and urethanized to form a water-absorbent resin (B) in a urethane resin composition (U).
Alternatively, a method for producing a urethane resin composition in which the hydrogel is dispersed. Water absorbent resin dispersion (D): one or more vinyl monomers (1) having a carboxyl group or a sulfonic acid group in the polyoxyalkylene compound (A) in the presence of water, a copolymerizable crosslinking agent (2) ) And a water-absorbent resin (B) formed by polymerizing another vinyl monomer (3) if necessary, or a water-absorbent resin dispersion obtained by dispersing the water-absorbent gel thereof in (A).