JPH11241030A - Water absorbent composition and absorbing article made therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water absorbent composition which can give an absorbing article which retains a good deodorant function even after a long term after absorption of urine, deteriorates less in its deodorant function even after a long-term storage before use, and has a high degree of whiteness by combining an extract of a conifer with a water-absorbing resin having a specified absorption index. SOLUTION: This composition contains an extract of a conifer and a water- absorbing resin having a pressure discontinuous absorption index of 0.80 or above. Such a water-absorbing resin can be obtained by crosslinking the part near the surface of a water-absorbing resin precursor synthesized by aqueous solution polymerization or reversed-phase suspension polymerization with a surface crosslinking agent to give to the part a crosslinking density higher than that of the inside. The composition is obtained by adding an extract of a conifer to a water-absorbing resin having a pressure discontinuous absorption index of 0.80 or above. The extract is desirably used in an amount of 0.01-20 pts.wt. per 100 pts.wt. water-absorbing resin (in terms of the solid matter). The extract is desirably one of a hinoki or a white cedar.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention relates to a water-absorbing agent composition and an absorbent article using the water-absorbing agent composition. The present invention relates to a water-absorbing agent composition capable of imparting a particularly excellent deodorizing function when it is used.

[0002]

2. Description of the Related Art In recent years, water-absorbent resins have been widely used as one of the constituent materials of sanitary materials such as disposable diapers, sanitary napkins and incontinence pads for the purpose of absorbing body fluids.

Examples of the water-absorbing resin include a crosslinked product of a partially neutralized polyacrylic acid, a hydrolyzate of a starch-acrylonitrile graft polymer, a neutralized product of a starch-acrylic acid graft polymer, and vinyl acetate-acrylic acid. Saponified ester copolymer, cross-linked carboxymethyl cellulose,
Hydrolyzate of acrylonitrile copolymer or acrylamide copolymer or cross-linked product thereof, cross-linked product of cationic monomer, cross-linked isobutylene-maleic acid copolymer, cross-linking of 2-acrylamido-2-methylpropane sulfonic acid and acrylic acid The body is known.

[0004] Conventionally, the water-absorbing properties desired for the above-mentioned water-absorbing resin include a high absorption capacity when contacted with an aqueous liquid such as a body fluid, an excellent absorption rate, a liquid permeability, a gel strength of a swollen gel,
A suction amount or the like for sucking water from a base material containing an aqueous liquid has been proposed.

[0005] In addition, various attempts have conventionally been made to add a deodorizing and antibacterial compound to the water-absorbing resin to give the resin an additional function.

[0006] Examples of these include a water absorbing agent comprising a water-absorbing resin and a leaf extract of a Camellia plant (Japanese Patent Application Laid-Open No. 60-158861).
Japanese Patent Application Laid-Open No. 63-135501), a disposable diaper containing a resin containing benzalkonium chloride and / or chlorhexidine gluconate in a water-absorbent resin, and a volatile monoterpene compound as a water-absorbent resin. A gel insecticide obtained by absorbing an aqueous emulsion as a component (Japanese Patent Application Laid-Open No. 4-139104), and a liquid obtained by dissolving or dispersing an antibacterial agent in a volatile solvent in a water-absorbing resin, and then applying the volatile A method for producing an antibacterial resin composition in which a solvent is removed and an antibacterial film is provided on the surface of a water-absorbent resin (Japanese Patent Laid-Open No. 3-59075)
Water-absorbing resin containing phosphate with antibacterial properties (JP-A-5-79053, JP-A-7-165981), deodorant resin composition in which zeolite particles are dispersed inside the water-absorbing resin (JP-A-8-176338) and the like are known.

[0007] However, it has been found that there is still a problem if only a deodorant compound generally added to a water-absorbent resin is added. That is, the present inventors have studied the deodorizing function of the water-absorbent resin in more detail, and as a result, have found that the deodorizing function is significantly reduced as time passes after absorbing liquid such as urine. It has also been found that the deodorizing performance of the resin may decrease with time before use. In addition, the use of sanitary materials and the like has been limited in some cases because the water-absorbent resin having a relatively excellent deodorizing function has been colored.

[0008]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an excellent deodorizing function even after a long time has passed after absorbing urine, and to maintain the deodorizing function even when left for a long time before use. An object of the present invention is to provide a water-absorbing composition having a high degree of whiteness without a decrease in function, and an absorbent article using the water-absorbing composition.

Accordingly, the present invention provides a novel water-absorbing agent composition capable of imparting extremely excellent deodorizing performance to sanitary materials for a long period of time, and a method for producing the same.

[0010]

Means for Solving the Problems The present inventors have conducted intensive studies from the viewpoint of imparting stable deodorizing performance over a long period of time, and as a result, when a specific compound is combined with a water-absorbing resin having properties of properties, and The inventors have found that the above object can be achieved when a powder carrying a specific compound and a water-absorbing resin are combined, and have completed the present invention.

That is, the water-absorbing agent composition according to the first aspect of the present invention has a coniferous tree extract and a discontinuous absorption index under pressure of 0.5.
It is characterized by containing more than 80 water-absorbing resins.

[0012] The water absorbing agent composition of the invention according to claim 4 is
Discontinuous absorption index under pressure of 0.80 including coniferous tree extract
It is characterized by the above.

The method for producing a water-absorbing agent composition according to the present invention is characterized in that a coniferous tree extract is added to a water-absorbent resin having a discontinuous absorption index of 0.80 or more under pressure.

[0014] The water-absorbing composition of the invention according to claim 6 is characterized in that it contains a powder carrying a coniferous tree extract in powder form and a water-absorbing resin.

The weight ratio α of the water-absorbent resin to the total amount of the water-absorbent resin and the fibrous base material is as follows.
An absorbent article comprising an absorbent layer containing an absorbent having a particle size of 0.3 or more, a liquid-permeable top sheet, and a liquid-impermeable back sheet, wherein the water-absorbent resin is a coniferous tree extract and It is characterized by using a water-absorbing agent composition comprising a water-absorbing resin having a continuous absorption index of 0.80 or more.

The water-absorbing composition of the invention according to claim 8 is a water-absorbing composition having a whiteness of 65 or more and a discontinuous absorption index under pressure of 0.80 or more. The urine odor of the swollen gel after absorbing urine and leaving it at 37 ° C for 24 hours is reduced compared to the case where the same operation was performed using Aquaric CAW-4 manufactured by Nippon Shokubai as a standard water absorbent resin. It is characterized by becoming.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

The water-absorbing resin usable in the present invention has a discontinuous absorption index under pressure of 0.80 or more. Discontinuous absorption index under pressure refers to the absorption capacity of a gel that has absorbed a predetermined amount of liquid less than the saturated amount and then absorbed to the saturated absorption amount under a specific load after leaving it for 6 hours. It is represented by the ratio to the so-called absorption capacity under pressure in which the liquid is continuously absorbed up to the absorption amount. When this value is less than 0.80, even when combined with the compound of the present invention, the deodorizing function after a long time is not sufficient, which is not preferable. Preferably, the resin has a discontinuous absorption index under pressure of 0.90 or more, more preferably 0.95 or more.

Such a water-absorbent resin is generally obtained by a production method in which a specific water-absorbent resin precursor is subjected to surface crosslinking under specific conditions. The above-mentioned water-absorbent resin precursor preferably has an average particle size in the range of 100 μm to 600 μm, and more preferably has an average particle size in the range of 100 μm to 400 μm.

The water-absorbing resin precursor is synthesized, for example, by aqueous solution polymerization or reverse phase suspension polymerization. Specific examples of the water-absorbent resin precursor include, for example, a crosslinked product of partially neutralized polyacrylic acid, a hydrolyzate of starch-acrylonitrile graft polymer, a neutralized product of starch-acrylic acid graft polymer, and acetic acid. Saponified vinyl-acrylate copolymer, hydrolyzate of acrylonitrile copolymer or acrylamide copolymer or cross-linked product thereof, carboxyl group-containing cross-linked polyvinyl alcohol-modified product, cross-linked isobutylene-maleic anhydride copolymer, etc. Is mentioned.

The above-mentioned water-absorbing resin precursor is, for example, an unsaturated carboxylic acid such as (meth) acrylic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid, itaconic acid, β-acryloyloxypropionic acid or the like. After polymerizing or copolymerizing one or more monomers selected from neutralized products of the above, the polymer is subjected to operations such as pulverization and classification as necessary to adjust the average particle size to the above. can get. Among the above monomers, (meth) acrylic acid and their neutralized products are more preferable.

Further, the water-absorbing resin precursor may be a copolymer of the above monomer and another monomer copolymerizable with the monomer. As the other monomer, specifically,
For example, vinyl sulfonic acid, styrene sulfonic acid, 2-
(Meth) acrylamide-2-methylpropanesulfonic acid, 2- (meth) acryloylethanesulfonic acid, 2-
Anionic unsaturated monomers such as (meth) acryloylpropanesulfonic acid and salts thereof; acrylamide, methacrylamide, N-ethyl (meth) acrylamide, N
-N-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, methoxypolyethylene glycol (meth) ) Nonionic hydrophilic group-containing unsaturated monomers such as acrylate, polyethylene glycol mono (meth) acrylate, vinylpyridine, N-vinylpyrrolidone, N-acryloylpiperidine, N-acryloylpyrrolidine; N, N-dimethylaminoethyl ( (Meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylamide, and quaternary salts thereof And cationic unsaturated monomers such.

It is essential that the water-absorbing resin precursor is internally crosslinked by reacting or copolymerizing with a crosslinking agent having a plurality of polymerizable unsaturated groups or a plurality of reactive groups. Specific examples of the crosslinking agent include N, N'-methylenebis (meth) acrylamide, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, and trimethylolpropane. Di (meth) acrylate, trimethylolpropane tri (meth) acrylate, glycerin tri (meth) acrylate, glycerin acrylate methacrylate, ethylene oxide-modified trimethylolpropane tri (meth) acrylate pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meta) ) Acrylate, triallyl cyanurate, triallyl isocyanurate, triallyl phosphate, triallylamine, poly (meth) allyloxyalkane, (poly) ethylene glycol Chole diglycidyl ether, glycerol diglycidyl ether,
Ethylene glycol, polyethylene glycol, propylene glycol, glycerin, pentaerythritol,
Ethylenediamine, polyethyleneimine, glycidyl (meth) acrylate and the like can be mentioned. These crosslinking agents may be used alone or as a mixture of two or more. Among the compounds exemplified above, it is more preferable to use a compound having a plurality of polymerizable unsaturated groups as a crosslinking agent.

The amount of the crosslinking agent used is preferably in the range of 0.01 mol% to 2 mol% with respect to the total amount of the above monomers,
More preferably, it is in the range of 3 mol% to 0.2 mol%. When the amount of the crosslinking agent used is less than 0.01 mol%, a surface cross-linking treatment described below is carried out, and the discontinuous absorption index under pressure is 0.80%.
Note that the above characteristics may not be easily obtained.

At the start of the polymerization, for example, potassium persulfate, ammonium persulfate, sodium persulfate,
t-butyl hydroperoxide, hydrogen peroxide, 2,
A radical polymerization initiator such as 2′-azobis (2-amidinopropane) dihydrochloride or an active energy ray such as an ultraviolet ray or an electron beam can be used. When an oxidizing radical polymerization initiator is used, redox polymerization may be performed using a reducing agent such as sodium sulfite, sodium hydrogen sulfite, ferrous sulfate, or L-ascorbic acid in combination. The amount of these polymerization initiators used is preferably in the range of 0.001 mol% to 2 mol%, more preferably in the range of 0.01 mol% to 0.5 mol%.

It is also preferable to increase the specific surface area by adding a foaming agent such as a carbonate or an azo compound, an inert gas, or the like to the monomer at the time of polymerization, and forming the resulting water-absorbent resin precursor into a porous structure. .

The water-absorbent resin precursor may be granulated in a predetermined shape, or may be in various shapes such as a sphere, a scale, an irregular crushed shape, and a granule. Further, the water absorbing resin precursor may be primary particles,
Granules of secondary particles may be used.

The above water-absorbent resin precursor generally has a discontinuous absorption index under pressure that does not satisfy the range in the present invention. For this reason, it is necessary to make the crosslink density near the surface of the water-absorbent resin precursor higher than that inside by using a surface crosslinker. That is, by cross-linking the vicinity of the surface of the water-absorbent resin precursor using the specific surface cross-linking agent, a water-absorbent resin as a base polymer usable in the present invention can be obtained.

That is, the water-absorbent resin according to the present invention is preferably a water-absorbent resin precursor obtained by the above-described aqueous solution polymerization, that is, having an average particle diameter in the range of 100 μm to 600 μm.
More preferably, it is obtained by heat-treating a product obtained by adjusting the polymerization, classification and the like so that the average particle size is in the range of 100 μm to 400 μm in the presence of a surface crosslinking agent.

The above-mentioned surface cross-linking agent has a functional group of the water-absorbent resin precursor, for example, a functional group capable of reacting with an acidic group. You.

When the functional group of the water absorbent resin precursor is, for example, a carboxyl group, ethylene glycol, diethylene glycol, propylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, 1,3-propanediol, Dipropylene glycol, 2,2,4-trimethyl-1,3-pentadiol, polypropylene glycol, glycerin, polyglycerin, 2-butene-
1,4-diol, 1,4-butanediol, 1,5-
Pentanediol, 1,6-hexanediol, 1,2
Polyhydric alcohol compounds such as cyclohexanedimethanol, 1,2-cyclohexanol, trimethylolpropane, diethanolamine, triethanolamine, polyoxypropylene, oxyethyleneoxypropylene block copolymer, pentaerythritol and sorbitol; ethylene glycol diglycidyl Ether, polyethylene diglycidyl ether, glycerol polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polyhydric epoxy compounds such as glycidol; ethylenediamine, diethylenetriamine, Triethylenetetramine, tetraethylenepentamine, pentae Renhekisamin, polyallylamine, polyamine compounds such as polyethyleneimine; 2,4
Polyvalent isocyanate compounds such as tolylene diisocyanate and hexamethylene diisocyanate; polyvalent oxazoline compounds such as 1,2-ethylenebisoxazoline;
1,3-dioxolan-2-one, 4-methyl-1,3
-Dioxolan-2-one, 4,5-dimethyl-1,3
Dioxolan-2-one, 4,4-dimethyl-1,3
-Dioxolan-2-one, 4-ethyl-1,3-dioxolan-2-one, 4-hydroxymethyl-1,3-
Dioxolan-2-one, 1,3-dioxan-2-one, 4-methyl-1,3-dioxan-2-one, 4,
6-dimethyl-1,3-dioxan-2-one, 1,3
Alkylene carbonate compounds such as dioxopan-2-one; epichlorohydrin, epibromohydrin, α
-A haloepoxy compound such as methyl epichlorohydrin;
Zinc, calcium, magnesium, aluminum, iron,
Polyhydric metal compounds such as hydroxides and chlorides such as zirconium; γ-glycidoxypropyltrimethoxysilane, γ
Silane coupling agents such as -aminopropyltriethoxysilane; and one or more silane coupling agents. Preferably, polyhydric alcohol compounds, polyamine compounds, polyepoxy compounds, and alkylene compounds
It contains at least one member selected from the group consisting of carbonate compounds.

The amount of the surface cross-linking agent used depends on the compound to be used and the combination thereof, but is preferably in the range of 0.001 to 5 parts by weight based on 100 parts by weight of the solid content of the water-absorbing resin precursor. And more preferably in the range of 0.01 to 1 part by weight. By using the above surface cross-linking agent, the water-absorbent resin precursor, that is, the cross-link density near the surface of the water-absorbent resin can be higher than the inside, the discontinuous absorption index under pressure required for the resin of the present invention. Can be enhanced. When the amount of the surface cross-linking agent exceeds 10 parts by weight, not only is it uneconomical, but also because the amount of the surface cross-linking agent becomes excessive in forming the optimum cross-linked structure in the water-absorbing resin, the absorption capacity is increased. Is undesirably reduced. The amount of the surface crosslinking agent used is 0.0
If the amount is less than 01 parts by weight, the discontinuous absorption index under pressure of the water-absorbent resin may not be easily improved.

When mixing the water-absorbing resin precursor and the surface crosslinking agent, it is preferable to use water as a solvent. The amount of water used depends on the type and particle size of the water-absorbing resin precursor, but is 0% based on 100 parts by weight of the solid content of the water-absorbing resin precursor.
And preferably not more than 20 parts by weight, more preferably in the range of 0.5 to 10 parts by weight.

When mixing the water-absorbing resin precursor with the surface crosslinking agent, a hydrophilic organic solvent may be used as a solvent, if necessary. As the above hydrophilic organic solvent,
For example, lower alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, t-butyl alcohol; ketones such as acetone;
Ethers such as dioxane and tetrahydrofuran;
Amides such as N-dimethylformamide; sulfoxides such as dimethyl sulfoxide; and the like. The amount of the hydrophilic organic solvent used depends on the type and particle size of the water-absorbing resin precursor, but is preferably 20 parts by weight or less, and more preferably 0.1 part by weight, based on 10 parts by weight of the solid content of the water-absorbing resin precursor. More preferably, it is within the range of 10 to 10 parts by weight.

When mixing the water-absorbing resin precursor and the surface crosslinking agent, for example, the water-absorbing resin precursor may be dispersed in the above-mentioned hydrophilic organic solvent, and then the surface crosslinking agent may be mixed. However, the mixing method is not particularly limited. Among various mixing methods, a method in which a surface cross-linking agent dissolved in water and / or a hydrophilic organic solvent, if necessary, is directly sprayed or dropped onto the water-absorbent resin precursor and mixed. In the case of mixing using water, fine powder insoluble in water, a surfactant or the like may be allowed to coexist.

The mixing device used for mixing the water-absorbent resin precursor and the surface crosslinking agent preferably has a large mixing force in order to uniformly and surely mix the two. As the mixing device, for example, a cylindrical mixer,
Double wall conical mixer, V-shaped mixer, ribbon mixer,
Suitable examples include a screw mixer, a fluid-type furnace rotary desk mixer, an airflow mixer, a double-arm kneader, an internal mixer, a pulverizing kneader, a rotary mixer, and a screw extruder.

After mixing the water-absorbing resin precursor and the surface cross-linking agent, a heat treatment is performed to crosslink the vicinity of the surface of the water-absorbing resin precursor. The temperature of the heat treatment depends on the surface cross-linking agent used, but is preferably from 40 ° C. to 250 ° C. When the treatment temperature is lower than 40 ° C., a uniform crosslinked structure is not formed, so that a water-absorbent resin having a discontinuous absorption index under pressure falling within the range of the present invention may not be obtained. If the treatment temperature exceeds 250 ° C., the water-absorbent resin may be degraded, and the performance of the water-absorbent resin may be reduced.

The above heat treatment can be carried out using a usual dryer or heating furnace. Examples of the dryer include a groove-type mixing dryer, a rotary dryer, a desk dryer, a fluidized-bed dryer, a flash dryer, and an infrared dryer.

The water-absorbing agent composition of the present invention can be obtained by adding a coniferous tree extract to the water-absorbing resin having a discontinuous absorption index of 0.80 or more under pressure obtained as described above.

The coniferous tree extract that can be used in the present invention refers to essential oil, distillate, etc., obtained by subjecting coniferous chips to steam distillation or the like. Only a single component contained in the coniferous tree is extracted. It is not what was taken out, but a total of various components. It is preferable to use a liquid that is slightly colored or hardly colored among these extracted extracts because the whiteness of the water-absorbing agent composition as a final product can be improved. Conifers that can be preferably used in the present invention are hinoki,
Hiba, cedar, hemlock, fir, larch, spruce, red pine, fir and the like can be exemplified. Preferred are hinoki and hiba extract, more preferably hiba oil and hiba distillate. In particular, those extracted from Aomori Hiba are particularly preferably used in the present invention.

The amount of these coniferous tree extract extracts used is as follows:
Although it depends on the intended deodorizing function, the amount of addition is preferably in the range of 0.01 to 20 parts by weight with respect to 100 parts by weight of the water-absorbent resin solids.

The method of adding the coniferous tree extract may be such that a desired amount of the coniferous tree extract is added when a water-absorbent resin having a discontinuous absorption index of 0.80 or more under pressure is used. A coniferous tree extract may be dissolved or dispersed in an aqueous liquid or various organic solvents, or the like, and may be directly sprayed or dropped onto the water-absorbent resin. It is preferable to mix the powder supported on the powder as it is because the deodorizing function can be maximized. In addition, when a powder in which a coniferous tree extract is previously supported on various inorganic or organic powders is used, an excellent deodorant function can be imparted regardless of the discontinuous absorption index under pressure of the water absorbent resin described above. From this viewpoint, it is preferable to use a powder in which a coniferous tree extract is supported in advance on various inorganic or organic powders.

The inorganic or organic powder preferably used for supporting the coniferous tree extract of the present invention includes:
For example, silicon dioxide, titanium dioxide, aluminum oxide, magnesium oxide, zinc oxide, clay, talc, calcium phosphate, barium phosphate, silicic acid or a salt thereof,
Clay, diatomaceous earth, silica gel, zeolite, bentonite, kaolin, hydroxyapatite, hydrotalcite, vermiculite, perlite, isolite,
Activated clay, silica sand, silica stone, strontium ore, fluorite, bauxide, and other inorganic powders; polyethylene, polypropylene, polyvinyl chloride, polystyrene, nylon, melamine resin, polymethyl methacrylate, starch, dextrin, cyclodextrin, cellulose ,
Examples include organic powders such as ethyl cellulose, wood flour, activated carbon, and tea leaves, and one or more of these can be used. Preferred are starch and dextrin.

Of these inorganic or organic powders, particles having a particularly fine particle diameter are particularly preferred. Particles having a particle size of 100 μm or less, preferably 50 μm or less, more preferably 10 μm or less can be used. In addition, it is preferable to use a powder that is slightly colored or hardly colored among these inorganic or organic powders because the whiteness of the water-absorbing agent composition as a final product can be improved.

When the coniferous tree extract is mixed with an inorganic or organic powder, the coniferous tree extract may be mixed alone, but the coniferous tree extract may be mixed with a solution of water or various organic solvents. And then mix. In the present invention,
To mix the water-insoluble particulate compound and the crosslinking agent, the water-insoluble particulate compound is sprayed or dropped with the crosslinking agent, for example, as an aqueous solution, a hydrophilic organic solvent solution, a mixed solvent solution or a dispersion. It is common to mix.

As described above, the amount of the extract of coniferous tree used is based on 100 parts by weight of the solid content of the water-absorbent resin.
It is preferred that the amount be in the range of 0.01 to 10 parts by weight, and generally 100 parts by weight of inorganic or organic powder, 1 to 500 parts by weight of coniferous tree extract, preferably 5 to 50 parts by weight. It is. 50 percentage of inorganic or organic powder
If it exceeds 0 parts by weight, the mixture tends to be in a slurry state,
Reaction and absorption start at the time of mixing with the water-absorbing resin, and it may be difficult to keep the deodorant function stable over time. When the ratio of the coniferous tree extract is less than 1 part by weight, the ratio of the inorganic or organic powder carrying the coniferous tree extract to the water-absorbent resin to be modified becomes large, and the resin is obtained. The water absorbing agent composition tends to have poor water absorbing properties.

In the present invention, a water-absorbent resin and a coniferous tree extract, a coniferous tree extract and an inorganic or organic powder, or a water-absorbent resin and an inorganic or organic powder carrying a coniferous tree extract are mixed. As the device used in this case, a conventional device may be used, for example, a cylindrical mixer, a screw mixer, a screw extruder, a turbulizer, a Nauter mixer, a V mixer, a ribbon mixer. , A double-arm type kneader, a flow type mixer, an air-flow type mixer, a rotating disk type mixer, a roll mixer, a tumbling type mixer, and the like, and the mixing speed may be high or low.

In the present invention, after mixing the water-absorbing resin with the coniferous tree extract, water, steam, or an aqueous liquid comprising water and a hydrophilic organic solvent may be added as necessary. The amount of water used in this case varies depending on the type and particle size of the water-absorbent resin, but is usually 10 parts by weight or less, preferably 1 to 100 parts by weight based on the solid content of the water-absorbent resin. The range is 5 parts by weight. Similarly, the amount of the hydrophilic organic solvent used is generally 10 parts by weight or less, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the solid content of the water-absorbent resin.

The water-absorbing agent composition obtained by the above-mentioned production method contains a coniferous tree extract, has a discontinuous absorption index of 0.80 or more under pressure, and contains a powder having the coniferous tree extract on a powder and a water-absorbing agent. And a discontinuous absorption index under pressure of 0.8 with whiteness of 65 or more.
0 or more water-absorbing agent compositions, wherein 2.0 g of the water-absorbing agent composition absorbs 50 g of adult urine and after standing at 37 ° C. for 24 hours, the odor of the urine of the swollen gel is defined as a standard water-absorbing resin ( This is a reduction from the case where the same operation is performed using Aquaric CAW-4 manufactured by Nippon Shokubai Co., Ltd.

Such a water-absorbing agent composition of the present invention can maintain its deodorizing function well even after a long time has passed after absorbing urine, and can maintain its deodorizing function even if left for a long time before use. It shows very excellent performance without reduction, and can be used for a wide range of sanitary materials because of no coloring of the resin.

Further, in the absorbent article of the present invention, the weight ratio α of the water-absorbing resin to the total amount of the water-absorbing resin and the fiber base is 0.5.
An absorbent article comprising an absorbent layer containing an absorbent body that is 3 or more, a liquid-permeable top sheet, and a liquid-impermeable back sheet, wherein the water-absorbent resin is a coniferous tree extract and discontinuous under pressure. It is characterized by using a water-absorbing agent composition containing a water-absorbing resin having an absorption index of 0.80 or more. The weight ratio α of the water absorbent resin to the total amount of the water absorbent resin and the fiber base is 0.
If it is less than 3, the amount of the water-absorbing resin used is relatively small, and the deodorizing function may not be sufficiently exhibited. Further, in the case where the liquid impermeable sheet has the property of permeating vapor, a problem of odor has conventionally occurred, but by using the water absorbing agent composition of the present invention, an excellent deodorizing function is imparted. A liquid-impermeable sheet having good air permeability and good air permeability can be used without any problem.

Specific examples of such absorbent articles include hygienic materials such as adult diapers, which have been growing rapidly in recent years, diapers for children, sanitary napkins, so-called incontinence pads, and the like. Although not intended to be used, the water-absorbing agent composition present in the absorbent article has a very excellent deodorizing function, and the deodorizing function is not reduced before use. It also exhibits a very excellent deodorizing function, and can greatly reduce the burden on the wearing person and the caregiver.

[0053]

The water-absorbing agent composition of the present invention can maintain its deodorizing function well even after a long time has passed after absorbing urine, and its deodorizing function decreases even if it is left for a long time before use. No water absorbing agent composition. Although the cause is not clear, the water-absorbent resin having a specific value of discontinuous absorption index under pressure is because the surface state of the swelling gel is always stable for a long time even if urine is absorbed, or coniferous trees In the case where the extract is previously supported on various inorganic or organic powders, the conifer extract can be present outside the particle surface regardless of the surface state of the water-absorbent resin. It is considered that the shift to the periphery occurs efficiently without hindering for a long time, and an excellent deodorizing function can be provided for a long time.

The absorbent article of the present invention contains the water-absorbing agent of the present invention and can impart an excellent deodorizing function.
It can be particularly suitably used for sanitary materials such as disposable diapers and sanitary napkins, adult incontinence pads, and adult diapers.
Since the absorption capacity under pressure is also stable for a long time, excellent absorption characteristics can be maintained for a long time.

[0055]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. The various properties of the water-absorbent resin were measured by the following methods.

(A) Absorption capacity 0.2 g of a water-absorbent resin (or water-absorbing agent composition) was uniformly placed in a nonwoven bag (60 mm × 60 mm), and immersed in a 0.9% by weight aqueous sodium chloride solution (physiological saline). . After 60 minutes, the bag was lifted, and after draining with a centrifuge at 250 G for 3 minutes, the weight W1 (g) of the bag was measured. The same operation was performed without using a water absorbing agent, and the weight W
0 (g) was measured. And these weights W1, W0
From the following formula, absorption capacity (g / g) = (weight W1 (g) −weight W0 (g)) /
The absorption capacity (g / g) was calculated according to the weight (g) of the water absorbent resin.

(B) Absorption Capacity Under Pressure First, a measuring apparatus used for measuring the absorption capacity under pressure will be briefly described with reference to FIG.

As shown in FIG. 1, the measuring device is a balance 1
And a container 2 having a predetermined capacity mounted on the balance 1, an outside air suction pipe 3, a conduit 4, a glass filter 6, and a measuring unit 5 mounted on the glass filter 6. I have. The container 2 has an opening 2a at the top and an opening 2b at the side surface thereof.
The outside air suction pipe 3 is fitted into the opening a, and the conduit 4 is attached to the opening 2b. The container 2 contains a predetermined amount of physiological saline solution 11 (aqueous solution of 0.9% by weight of sodium chloride). The lower end of the outside air suction pipe 3 is submerged in the physiological saline 11. The glass filter 6 has a diameter of 70 mm. The container 2 and the glass filter 6 are in communication with each other by the conduit 4. The upper part of the glass filter 6 is fixed at a position slightly higher than the lower end of the outside air suction pipe 3. The measuring unit 5 includes a filter paper 7, a support cylinder 8, a wire mesh 9 attached to a bottom of the support cylinder 8,
And a weight 10. Then, the measuring unit 5 places the filter paper 7 and the support cylinder 8 (that is, the wire mesh 9) on the glass filter 6 in this order, and places the weight 10 inside the support cylinder 8, that is, on the wire mesh 9. It has been. The support cylinder 8 has an inner diameter of 60 mm. The wire mesh 9 is made of stainless steel and has a mesh of 400 mesh (mesh size of 38 μm).
m). Then, a predetermined amount of the water-absorbing resin (or water-absorbing agent composition) is evenly spread on the wire mesh 9. The weight of the weight 10 is adjusted so that a load of 20 g / cm 2 can be uniformly applied to the wire mesh 9, that is, the water-absorbing resin.

The absorption capacity under pressure was measured using the measuring apparatus having the above-mentioned structure. The measuring method will be described below.

First, predetermined preparation operations were performed, such as putting a predetermined amount of physiological saline 11 into the container 2 and fitting the outside air suction pipe 3 into the container 2. Next, the filter paper 7 was placed on the glass filter 6. On the other hand, in parallel with these placing operations, 0.9 g of the water-absorbing resin (or water-absorbing agent composition) was evenly spread on the inside of the support cylinder, that is, on the wire mesh 9, and the weight 10 was placed on the water-absorbing resin. .

Next, on the filter paper 7, the wire cylinder 9, that is, the support cylinder 8 on which the water-absorbent resin and the weight 10 were placed was placed.

Then, the weight W2 (g) of the physiological saline solution 11 absorbed by the water-absorbent resin was measured using the balance 1 for 60 minutes after the support cylinder 8 was placed on the filter paper 7. Then, from the above weight W2, the absorption capacity under pressure (g) 60 minutes after the start of absorption according to the following equation: absorption capacity under pressure (g / g) = weight W2 (g) / weight of water absorbent resin (g) / g)
Was calculated.

(C) Discontinuous Absorption Index Under Pressure The discontinuous absorption index under pressure was measured using the measuring apparatus having the configuration described in the section on absorption capacity under pressure. The measuring method will be described below. First, the inside of the support cylinder 8, that is, the wire mesh 9
0.9 g of a water-absorbing resin (or water-absorbing agent composition) is evenly spread on the top. Add 13.5 g of physiological saline to a separately prepared Petri dish, place a wire mesh with water-absorbing resin on it without applying a load, and allow the resin to absorb the physiological saline in the Petri dish by 15-fold swelling gel And allowed to stand for 6 hours.

After 4 hours, a weight 10 was placed on the swollen water-absorbent resin. Next, the filter paper 7 was placed on the glass filter 6. Next, the supporting cylinder 8 on which the wire mesh 9, that is, the water-absorbent resin and the weight 10 was placed, was placed on the filter paper 7.

The weight W 3 (g) of the physiological saline solution 11 absorbed by the water-absorbent resin was measured using the balance 1 for 60 minutes after the support cylinder 8 was placed on the filter paper 7. Then, from the above-mentioned weight W3, the following discontinuous absorption index under pressure = [(weight W3 (g) +13.5) / weight of water-absorbent resin (g) / absorption capacity under pressure (g / g)] The discontinuous absorption index under pressure was calculated.

(D) Deodorizing test 50 ml of human urine collected from 10 adults was added to a 120 ml polypropylene cup with a lid, and 24102.0 g of a water-absorbing resin (or water-absorbing agent composition) was added thereto to form a swollen gel. Was formed. Human urine was used within 2 hours after excretion. The container was capped and the swollen gel was kept at 37 ° C. After 1 hour and 24 hours, the lid was opened, and 10 adult panelists smelled the odor from a position about 3 cm from the top of the cup, and the deodorizing effect was determined.

1: (odorless), 2: (almost no noticeable odor), 3: (perceptible but acceptable odor),
Scores were given on a five-point scale for each person on the basis of 4: (strong smell) and 5: (strong smell), and the average value was calculated. The deodorizing test result of Aqualic CA-W4 manufactured by Nippon Shokubai Co., Ltd., which was selected as a standard product, was 4.

(E) Whiteness SZ-II (Sigma) 80 type COLOUR M manufactured by Nippon Denshoku Industries Co., Ltd.
After calibrating the XYZ values with a standard white plate using the EASURING SYSTEM, the color of the water-absorbing agent composition was measured, and the so-called Hunter whiteness (Z / 1.18) was determined to be the whiteness. [Reference Example 1] To 5500 g of an aqueous solution of sodium acrylate having a neutralization rate of 75 mol% (monomer concentration: 33%),
4.48 g of polyethylene glycol diacrylate (average number of moles of ethylene oxide added: 8) was dissolved to prepare a reaction solution. Next, this reaction solution was degassed for 30 minutes under a nitrogen gas atmosphere. Next, an internal volume of 10 L having two sigma type blades
The above reaction solution is supplied to a reactor formed by attaching a lid to a jacketed stainless steel double-arm kneader of
While maintaining the temperature at 30 ° C., the system was replaced with nitrogen gas. Subsequently, 2.46 g of sodium persulfate and L
When 0.10 g of ascorbic acid was added, polymerization started about 1 minute later. Then, polymerization is performed at 30 ° C to 80 ° C,
60 minutes after the start of the polymerization, the hydrogel polymer was taken out. The obtained hydrogel polymer was subdivided into a diameter of about 5 mm. This finely divided hydrogel polymer is
It was spread on a 50-mesh wire net and dried with hot air at 150 ° C. for 90 minutes. Next, the dried product is ground using a vibration mill,
The average particle size is 280 by classifying with a 20 mesh wire mesh.
A μm-shaped irregularly crushed water-absorbent resin precursor (a) was obtained.

The obtained water-absorbent resin precursor (a) was composed of 100 parts by weight of propylene glycol, 0.05 parts by weight of ethylene glycol diglycidyl ether, 3 parts by weight of water, and 1 part by weight of isopropyl alcohol. The surface crosslinking agent was mixed. The mixture was heated at 210 ° C. for 45 minutes to obtain a water-absorbent resin (1). The water absorbing resin (1) had an absorption capacity under pressure of 34 (g / g) and a discontinuous absorption index under pressure of 0.91.

Reference Example 2 100 parts by weight of the water-absorbent resin precursor (b) obtained by changing the polyethylene glycol diacrylate (average number of moles of ethylene oxide added: 8) to 1.98 g in Reference Example 1, and adding glycerin 0.5 Parts by weight and water 2
A surface crosslinking agent consisting of 1 part by weight of isopropyl alcohol and 1 part by weight of isopropyl alcohol was mixed. The above mixture was heated at 190 ° C. for 50 minutes to obtain a water absorbent resin (2). The water absorbing resin (2) had an absorption capacity under pressure of 30 (g / g) and a discontinuous absorption index under pressure of 0.67.

Example 1 100 parts by weight of the water-absorbent resin (1) obtained in Reference Example 1 was mixed with 2 parts by weight of a powder having 20% of Hiba oil supported on dextrin, and a water-absorbing agent composition (1) was prepared. I got Table 1 summarizes various physical properties and deodorizing function of the water absorbing agent composition (1).

Example 2 100 parts by weight of the water-absorbent resin (1) obtained in Reference Example 1 was mixed with 1 part by weight of a powder having 20% of Hiba oil supported on starch, and a water-absorbing agent composition (2) I got Table 1 similarly summarizes various physical properties and a deodorizing function of the water-absorbing agent composition (2).

Example 3 0.4 parts by weight of hiba oil was mixed with 100 parts by weight of the water absorbent resin (1) obtained in Reference Example 1 to obtain a water absorbing agent composition (3). Table 1 similarly summarizes physical properties and deodorant functions of the water-absorbing agent composition (3).

Example 4 100 parts by weight of the water-absorbent resin (1) obtained in Reference Example 1 was mixed with 2 parts by weight of a powder containing 20% of Hiba oil in dextrin and put in a polyethylene bag for 3 months The mixture was left for a while to obtain a water absorbing agent composition (4). Table 1 summarizes various physical properties and deodorizing function of the water absorbing agent composition (4).

Example 5 100 parts by weight of the water-absorbent resin (2) obtained in Reference Example 2 was mixed with 2 parts by weight of a powder in which 20% of Hiba oil was supported on dextrin, and a water-absorbing agent composition (5) I got Table 1 summarizes various physical properties and deodorizing function of the water absorbing agent composition (5).

Comparative Example 1 0.4 parts by weight of hiba oil was mixed with 100 parts by weight of the water absorbent resin (2) obtained in Reference Example 2 to obtain a comparative water absorbing agent composition (1). Comparative water-absorbing composition (1)
Are shown in Table 1.

Comparative Example 2 0.5 part by weight of hinokitiol was mixed with 100 parts by weight of the water-absorbent resin (1) obtained in Reference Example 1,
A comparative water absorbing agent composition (2) was obtained. Table 1 summarizes various physical properties and deodorant functions of the comparative water-absorbing agent composition (2).

Comparative Example 3 A commercially available deodorant comprising green tea dry distilled extract in 100 parts by weight of the water-absorbent resin (1) obtained in Reference Example 1.
2 parts by weight were mixed to obtain a comparative water absorbing agent composition (3). Table 1 summarizes various physical properties and deodorant function of the comparative water absorbing agent composition (3).

[Comparative Example 4] A commercially available deodorant comprising green tea dry distilled extract in 100 parts by weight of the water absorbent resin (2) obtained in Reference Example 2.
2 parts by weight were mixed to obtain a comparative water absorbing agent composition (4). Table 1 summarizes various physical properties and deodorant functions of the comparative water-absorbing agent composition (4).

Comparative Example 5 0.5 part by weight of activated carbon was mixed with 100 parts by weight of the water absorbent resin (1) obtained in Reference Example 1 to obtain a comparative water absorbing agent composition (5). Table 1 summarizes various physical properties and deodorant functions of the comparative water-absorbing agent composition (5).

Comparative Example 6 0.5 part by weight of activated carbon was mixed with 100 parts by weight of the water-absorbent resin (1) obtained in Reference Example 1, placed in a polyethylene bag and allowed to stand for 3 months. 6)
I got Table 1 summarizes various physical properties and deodorant functions of the comparative water-absorbing agent composition (6).

Comparative Example 7 100 parts by weight of the water absorbing resin (1) obtained in Reference Example 1 was mixed with 0.5 part by weight of sodium iron chlorophyllin to obtain a comparative water absorbing agent composition (7). Table 1 summarizes various physical properties and deodorant functions of the comparative water-absorbing agent composition (7).

[0083]

[Table 1]

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a measuring device used for measuring an absorption capacity under pressure, which is one of the properties exhibited by a water-absorbent resin.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Balance 2 Container 3 External air suction pipe 4 Conduit 5 Measurement part 6 Glass filter 7 Filter paper 8 Support cylinder 9 Wire mesh 10 Weight 11 Physiological saline

──────────────────────────────────────────────────続 き Continued on front page (51) Int.Cl. ⁶ Identification code FI C08K 9/04 C08K 9/04

Claims (8)

[Claims] 1. A water-absorbing agent composition comprising a coniferous tree extract and a water-absorbing resin having a discontinuous absorption index under pressure of 0.80 or more. 2. The water-absorbing agent composition according to claim 1, wherein the coniferous tree extract is supported on a powder. 3. The water-absorbing composition according to claim 1, wherein the extract of coniferous tree is in the range of 0.01 to 20 parts by weight based on 100 parts by weight of the solid content of the water-absorbing resin. 4. A water-absorbing agent composition comprising a coniferous tree extract and having a discontinuous absorption index under pressure of 0.80 or more. 5. A method for producing a water-absorbing agent composition, comprising adding a coniferous tree extract to a water-absorbent resin having a discontinuous absorption index of 0.80 or more under pressure. 6. A water-absorbing agent composition comprising a powder carrying a coniferous tree extract in powder form and a water-absorbing resin. 7. An absorbent layer containing an absorbent having a weight ratio α of the water-absorbent resin to the total amount of the water-absorbent resin and the fiber base of 0.3 or more, a liquid-permeable topsheet, and a liquid-impermeable backsheet. An absorbent article comprising a sheet, wherein an absorbent article comprising a coniferous tree extract and a water absorbent resin having a discontinuous absorption index under pressure of 0.80 or more is used as the water absorbent resin. . 8. A discontinuous absorption index under pressure of a whiteness of 65 or more is 0.5.
80 or more water-absorbing agent compositions, 2.0 g of the water-absorbing agent composition absorbs 50 g of adult urine, and after standing at 37 ° C. for 24 hours, the odor of the urine of the swollen gel, as a standard water-absorbing resin ( A water-absorbing agent composition which is reduced as compared with the case where the same operation is performed using Aquaric CAW-4 manufactured by Nippon Shokubai Co., Ltd.