JP2009235199A - Water-absorbing resin composition, absorbent, and absorptive article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-absorbing resin composition capable of preventing propagation of bacteria along with the lapse of time after urination and preventing occurrence of malodor even in application to an absorptive article such as a diaper and a pet sheet. <P>SOLUTION: The water-absorbing resin composition includes water-absorbing resin particles (A) and an antibacterial agent (B), which is an ammonium salt represented by general formula (1), is used. In formula (1) (R<SP>1</SP>)<SB>2</SB>N<SP>+</SP>(R<SP>2</SP>)<SB>2</SB>X<SP>-</SP>; R<SP>1</SP>is n-decyl group, R<SP>2</SP>is methyl group, and X<SP>-</SP>is chloride ion or gluconic acid anion. Based on the weight of the water-absorbing resin particles (A), a preferable content of the antibacterial agent (B) is 0.001-1 wt.%. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a water-absorbing resin composition, an absorbent body using the same, and an absorbent article.

Water-absorbent resin comprising a hydrophilic polymer, and a powder modifier such as a liquid modifier (ethylene glycol, propylene glycol, diethylene glycol, polyethylene glycol, etc.) and an inorganic powder (aluminum oxide, magnesium oxide, zinc oxide, etc.) Is known (Patent Document 1).
JP-A-9-278900

However, when the conventional water-absorbent resin is used in absorbent articles such as diapers and pet sheets, there is a problem that bacteria thrive as time passes after urination and a bad odor is generated. As a result, there are problems of stress on the skin when the absorbent article is worn and discomfort to the wearer and surrounding people.
That is, the object of the present invention is to provide a water-absorbent resin composition that can prevent the growth of bacteria over time after urination and prevent the generation of malodor even when used in absorbent articles such as diapers and pet sheets. That is.

The water-absorbent resin composition of the present invention is characterized by containing water-absorbent resin particles (A) and an antibacterial agent (B), and the antibacterial agent (B) is an ammonium salt represented by the general formula (1). Is the gist.

(R ¹ ) ₂ N ⁺ (R ² ) ₂ X ⁻ (1)

[R ¹ is an n-decyl group, R ² is a methyl group, and X ⁻ is a chloride ion or a gluconate anion. ]

  Even when the water-absorbent resin composition of the present invention is applied to absorbent articles such as diapers and pet sheets, it is possible to prevent the growth of bacteria due to the passage of time after urination. Therefore, malodor does not occur, and stress on the skin at the time of wearing and discomfort to the wearer and the surrounding people can be significantly reduced.

<About water-absorbent resin particles (A)>
The water-absorbent resin particles (A) include a water-soluble vinyl monomer (a1) and / or a cross-linked polymer having the vinyl monomer (a2) which becomes (a1) by hydrolysis and an internal cross-linking agent (b) as essential constituent units. If there is no particular limitation, known ones {for example, the following polymers (1) to (16), etc.} can be used as they are.
(1) A starch-acrylic acid (salt) graft-crosslinked copolymer described in JP-B-53-46199 or JP-B-53-46200.
(2) Crosslinked polyacrylic acid (salt) obtained by aqueous solution polymerization (adiabatic polymerization, thin film polymerization, spray polymerization, etc.) described in JP-A-55-133413.
(3) Cross-linked polyacrylic acid (salt) obtained by reverse phase suspension polymerization described in JP-B-54-30710, JP-A-56-26909, or JP-A-11-5808.
(4) A saponified product of a copolymer of a vinyl ester and an unsaturated carboxylic acid or a derivative thereof described in JP-A-52-14689 or JP-A-52-27455.
(5) A copolymer of acrylic acid (salt) and a sulfo (sulfonate) group-containing monomer described in JP-A-58-2312 or JP-A-61-36309.

(6) A saponified product of crosslinked isobutylene-maleic anhydride copolymer described in US Pat. No. 4,389,513.
(7) A starch-acrylonitrile copolymer hydrolyzate described in JP-A-46-43995.
(8) Crosslinked carboxymethylcellulose as described in US Pat. No. 4,650,716 and the like.
(9) A polyalkylene (ethylene, propylene, etc.) glycol cross-linked product as described in the latest trend of polymer gels (CMC Publishing Co., Ltd., published in 2004).
(10) A crosslinked polyvinyl alcohol as described in the latest trend of polymer gels (CMC Publishing, published in 2004).
(11) A starch radiation cross-linked product described in JP-A-2003-48997.
(12) A carboxyl group-containing crosslinked cellulose described in JP-A-9-85080.
(13) A polyamino acid radiation cross-linked product described in JP-A-10-251402.
(14) The crosslinked polyaspartic acid described in JP-A-2002-179770.
(15) A polyvalent metal ion cross-linked product of a polysaccharide described in JP-A No. 2001-120992.

(16) JP-A-2003-057422, JP-A-2003-082250, JP-A-2003-165683, JP-A-2003-176421, JP-A-2003-183528, JP-A-2003-192732 JP, 2003-225565, JP 2003-238696, JP 2003-335970, JP 2004-009673, JP 2004-121400, JP 2004-123835, JP JP 2005-075982, JP 2005-095759, JP 2005-186015, JP 2005-186016, JP 2006-110545, JP 2006-122737, JP 2006. -131767, JP 2006 160774, JP 2006-206777, JP 2006-219661, JP-performance water-absorbent resin described in 2007-069161, etc. {crosslinked polyacrylic acid (salt)}.

Among these, (1), (2), (3) and (16) are preferable, (1), (2) and (16) are more preferable, and (2) and (16) are particularly preferable.
The water absorbent resin particles (A) may be surface-crosslinked.

  The shape of the water-absorbent resin particles (A) is not limited as long as it is particulate, but is preferably indefinite (crushed), true spherical, plate-like, and rod-like, and more preferably indefinite (crushed), true spherical or A plate shape, particularly preferably an irregular shape (crushed shape) or a plate shape.

  The particle diameter range of the water absorbent resin particles (A) can be adjusted by a known method (sieving, sieving after pulverization, etc.) and the like.

  100-800 are preferable, as for the weight average particle diameter (micrometer) of a water absorbing resin particle (A), More preferably, it is 200-500, Most preferably, it is 300-400. Within this range, the moisture resistance of the absorbent article is further improved.

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

<Antimicrobial agent (B)>
The ammonium salt represented by the general formula (1) is a tetraalkylammonium salt, but if it is an alkyl group other than the n-decyl group (R ¹ ) and the methyl group (R ² ), it has the effect of preventing the growth of bacteria. Remarkably inferior. Furthermore, the powder fluidity of the water absorbent resin composition is remarkably inferior. Therefore, if it is other than di-n-decyldimethylammonium salt, generation of malodor cannot be effectively prevented. Moreover, the handleability of the water-absorbent resin composition is extremely inferior.

If it is an anion other than a chloride ion or a gluconate anion (X ⁻ ), the effect of preventing the growth of bacteria is significantly inferior. Furthermore, the powder fluidity of the water absorbent resin composition is remarkably inferior. Therefore, if it is other than di-n-decyldimethylammonium salt, generation of malodor cannot be effectively prevented. Moreover, the handleability of the water-absorbent resin composition is extremely inferior.

  The ammonium salt represented by the general formula (1) includes di-n-decyldimethylammonium chloride, di-n-decyldimethylammonium gluconate and a mixture thereof.

The ammonium salt represented by the general formula (1) can be produced by a usual method.
It can be obtained by reacting di-n-decylmethylamine or n-decyldimethylamine with an alkylating agent to make it quaternized. In addition, anion exchange is performed as necessary.

  Examples of the alkylating agent include dimethyl sulfate, dimethyl carbonate, methyl chloride, methyl bromide, methyl iodide, di-n-decyl sulfate, di-n-decyl carbonate, n-decyl chloride, n-decyl bromide, and n-decyl iodide. It is done.

  For quaternization, a known solvent (for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, etc.) may be used.

  The quaternization temperature (° C.) is preferably 50 to 200, more preferably 50 to 150.

  As a method for anion exchange, for example, a method of gradually adding a methanol solution of di-n-decyldimethylammonium methyl carbonate to an aqueous gluconic acid solution and distilling off the generated carbon dioxide and the solvent can be applied. The reaction temperature for anion exchange is preferably about 80 to 90 ° C.

The antibacterial agent (B) is used as a solvent solution (for example, an alcohol solution) or an aqueous solution used during production.
When the antibacterial agent (B) is a solution, the concentration (% by weight) of the antibacterial agent is preferably 1 to 80, more preferably 5 to 60, based on the weight of the solution. When it is in this range, it is easy to handle from the viewpoint of viscosity and the like, and when mixing with the water absorbent resin particles (A), the amount of unnecessary solvent can be limited.

  The content (% by weight) of the antibacterial agent (B) is preferably 0.001 to 1, more preferably 0.1 to 0.8, particularly preferably 0, based on the weight of the water absorbent resin particles (A). .3 to 0.5. Within this range, even when applied to absorbent articles such as diapers and pet sheets, it is possible to prevent the growth of bacteria over time after urination. Therefore, malodor does not occur, and stress on the skin at the time of wearing and discomfort to the wearer and the surrounding people can be significantly reduced.

  The water absorbent resin composition of the present invention can be easily obtained by uniformly mixing the water absorbent resin particles (A) and the antibacterial agent (B). As a step of mixing the water absorbent resin particles (A) and the antibacterial agent (B), in the step of producing the water absorbent resin particles (A), when the water absorbent resin particles (A) are obtained by solution polymerization, the surface Immediately after the crosslinking reaction step (heating step) is preferred. Moreover, when obtaining a crosslinked polymer particle (A) by reverse phase suspension, it is immediately after a drying process.

In any case, the water-absorbent resin particles (A) are preferably mixed in a dry state in which the water content is 12% by weight or less (preferably 10% by weight or less, more preferably 8% by weight or less).
The moisture is heated by an infrared moisture measuring instrument (for example, JE400 manufactured by Kett Science Laboratory: 120 ± 5 ° C., 30 minutes, ambient humidity 50 ± 10% RH before heating, lamp specification 100V, 40W). It is calculated | required from the weight loss of the water absorbing resin particle (A) before and behind heating.

Although it does not specifically limit as temperature (degreeC) of uniform mixing, 30-100 are preferable, More preferably, it is 40-80, Most preferably, it is 50-60.
The apparatus used to uniformly mix the water absorbent resin particles (A) and the antibacterial agent (B) may be an ordinary mixer, for example, a cylindrical mixer, a screw mixer, a screw extruder. , Turbulizer, nauter mixer, double-arm kneader, fluid mixer, V mixer, ribbon mixer, fluid mixer, airflow mixer, rotary disk mixer, conical blender and roll A mixer etc. are mentioned.

In the water-absorbent resin composition of the present invention, an optional step {in the production process of the water-absorbent resin particles (A), a polymerization step, a crushing step, a drying step, a pulverizing step, a surface cross-linking step, and / or these steps, if necessary. An additive can be added before and after the process.
Examples of additives include known additives (for example, Japanese Patent Application Laid-Open No. 2003-225565) {preservatives, fungicides, antioxidants, ultraviolet absorbers, colorants, deodorants, organic fibrous materials, etc.} These can be used, and one or more of these may be used in combination.

The water-absorbent resin composition of the present invention can produce absorbent articles by applying it to various absorbers. The absorber and the absorbent article are manufactured by a known method (for example, Japanese Patent Application Laid-Open No. 2005-186016).
Absorbent articles include sanitary products {paper diapers (children's disposable diapers and adult disposable diapers, etc.), napkins (sanitary napkins, etc.), vomiting absorption etiquette bags, paper towels, pads (incontinence pads and surgical underpads) Etc.) and pet sheets (pet sheets and heat insulation sheets etc.)}, and various household and industrial absorbent sheets {freshness retention sheets, drip absorbent sheets, etc.}.
Among these, the water-absorbent resin composition of the present invention is suitable for sanitary goods from the viewpoint of preventing the growth of bacteria with the passage of time after urination and preventing the generation of malodor, and further, disposable diapers, pads and sanitary napkins, pets Suitable for sheets, especially paper diapers and pet sheets.

Hereinafter, although an example and a comparative example explain the present invention further, the present invention is not limited to these. Hereinafter, unless otherwise specified, parts are parts by weight.
<Production Example 1>
While stirring and mixing 88 parts of sodium acrylate, 22.85 parts of acrylic acid, 0.3 part of N, N′-methylenebisacrylamide, 293 deionized water and 0.001 part of dichlorotris (triphenylphosphine) ruthenium The temperature was kept at 1 to 2 ° C., and nitrogen was introduced into the mixed solution to make the dissolved oxygen concentration in the mixed solution 0.5 ppm or less. Subsequently, 0.3 part of a 1% by weight aqueous hydrogen peroxide solution, 0.8 part of a 0.2% by weight aqueous ascorbic acid solution and 2% by weight of an aqueous 2,2'-azobisamidinopropane dihydrochloride solution were added to this mixed solution. .8 parts was added and mixed to initiate polymerization, and after the reaction solution reached 80 ° C., polymerization was carried out at a polymerization temperature of 80 ± 2 ° C. for about 5 hours to obtain a water-containing resin (Gel 1).

  400 parts of this water-containing resin (Gel 1) was shredded at 25 ° C. for 5 minutes with a mincing machine (diameter hole diameter: 6 mm, 12VR-400K manufactured by Iizuka Kogyo Co., Ltd.), and then ventilated band dryer (135 ° C. 2.0 m / sec; manufactured by Inoue Metal Industry Co., Ltd.) to obtain a dry polymer.

  The dried polymer was pulverized with a juicer mixer (National MX-X53, manufactured by Matsushita Electric Industrial Co., Ltd.) and adjusted to a particle size range of 150 to 710 μm using a sieve having openings of 150 and 710 μm. While stirring at high speed (Hosokawa Micron Corporation, high-speed stirring turbulizer mixer: rotation speed 2000 rpm), 5% of a 1 wt% water / methanol mixed solution of ethylene glycol diglycidyl ether (weight ratio of water / methanol = 60/40) .5 parts were added and mixed while sprayed, and left at 140 ° C. for 30 minutes, followed by heat crosslinking (surface crosslinking) to obtain water-absorbing resin particles (A1).

<Production Example 2>
While stirring and mixing 81.8 parts of acrylic acid, 0.3 part of N, N′-methylenebisacrylamide and 241 parts of deionized water, the temperature is maintained at 1 to 2 ° C., and nitrogen is introduced into the mixture. Thus, the amount of dissolved oxygen in the mixed solution was set to 0.02 ppm or less. Subsequently, 1 part of a 1% by weight aqueous hydrogen peroxide solution, 1.2 parts of a 0.2% by weight aqueous ascorbic acid solution and 2% by weight of an aqueous 2,2′-azobisamidinopropane dihydrochloride 2.8% solution were added to this mixed solution. Part was added and mixed to initiate polymerization, and after the reaction temperature reached 70 ° C., polymerization was carried out at a polymerization temperature of 75 ± 5 ° C. for about 8 hours to obtain a water-containing resin (Gel 2).

  This water-containing resin (Gel 2) was shredded to a size of 3 to 7 mm with an internal mixer to obtain a shredded gel, and then 325 parts of the shredded gel was mixed with 67.5 parts of a 48 wt% aqueous sodium hydroxide solution. Was added to neutralize 72 equivalent% of the carboxyl groups to obtain a neutralized chopped gel. In addition, the neutralization degree of the neutralized chopped gel calculated from the acid value measured according to JIS K0113-1997 (using 0.1 N potassium hydroxide aqueous solution as a titrant, potentiometric titration method, inflection point method) Was 70.1 equivalent%.

  Next, this neutralized chopped gel is laminated to a thickness of about 5 cm on a stainless steel tray that is 20 cm long × 20 cm wide × 10 cm high, has no top plate, and has a 4 mm mesh wire mesh on the bottom plate. And it dried with the ventilation type | mold band dryer (made by Inoue Metal Industry Co., Ltd.) on the conditions of 150 degreeC and the wind speed of 2.0 m / s, and obtained the dry polymer.

  Water-absorbent resin particles (A2) were obtained from this dried polymer by the same method (Crushing, surface cross-linking) as in Production Example 1.

<Production Example 3>
After 121.2 parts of cyclohexane and 0.9 part of sorbitan monostearate were uniformly mixed, nitrogen was introduced into the mixed solution, and the amount of dissolved oxygen in the mixed solution was adjusted to 0.02 ppm or less to obtain a reaction solvent.

  On the other hand, 70 parts of a carboxyl group was neutralized by adding 70 parts of a 25% by weight aqueous solution of sodium hydroxide to a mixed liquid of 45 parts of acrylic acid and 6.4 parts of water under ice cooling. Furthermore, 0.033 part of N, N′-methylenebisacrylamide, 0.0546 part of sodium hypophosphite, and 0.0313 part of 2,2′-azobisamidinopropane dihydrochloride were added to this neutralized mixture. To obtain a monomer solution.

  This monomer solution was added to the previous reaction solvent, stirred and dispersed, and raised to 60 ° C. in an oil bath while introducing nitrogen. Subsequently, the temperature of this dispersion was kept at 60 ° C., and polymerization was carried out for 2 hours while stirring. After 2 hours, the water-containing resin swollen with water (gel 3) was dispersed in cyclohexane to form a slurry. Next, the temperature of the oil bath was increased, and dehydration was performed by azeotropy of cyclohexane and water until the water content of the swollen water-containing resin (gel 3) became 20% by weight. After dehydration, stirring was stopped, and the water-containing resin (gel 3) that settled was separated from the cyclohexane phase by decantation. This water-containing resin (Gel 3) was dried under reduced pressure at 80 to 90 ° C. and 13.3 kPa to obtain a dry polymer.

  Water-absorbent resin particles (A3) were obtained from this dry polymer by the same method (surface crosslinking) as in Production Example 1.

<Production Example 4>
After reacting 56 parts of methanol, 274 parts (0.88 mole part) of di-n-decylmethylamine and 144 parts (1.6 mole part) of dimethyl carbonate at 120 ° C. for 20 hours, methanol and dimethyl carbonate were distilled off. Then, the concentration was adjusted to 70% by weight to obtain a methanol solution of di-n-decyldimethylammonium methyl carbonate.

  While maintaining a mixed aqueous solution composed of 157 parts (0.4 mol part) of a 50% by weight aqueous gluconic acid solution and 300 parts of water at 80 to 90 ° C., 70% by weight di-n-decyldimethylammonium methyl carbonate was added to this mixed aqueous solution. 229 parts (0.4 mole part) of methanol was added over 2 hours, the generated carbon dioxide was removed, the solvent (water and methanol) was distilled off, and the antibacterial agent (B1) {di-n-decyldimethyl Ammonium gluconate} was obtained.

<Example 1>
100 parts of the water-absorbent resin particles (A1) and 0.001 part of the antibacterial agent (B1) {di-n-decyldimethylammonium gluconate} are uniformly mixed with a conical blender (manufactured by Hosokawa Micron Co., Ltd.). A water absorbent resin composition (1) was obtained.

<Example 2>
A water-absorbent resin composition (2) was obtained in the same manner as in Example 1 except that the amount of the antibacterial agent (B1) used was changed from “0.001 part” to “0.1 part”.

<Example 3>
A water absorbent resin composition (3) was obtained in the same manner as in Example 1 except that the amount of the antibacterial agent (B1) used was changed from “0.001 part” to “0.3 part”.

<Example 4>
A water absorbent resin composition (4) was obtained in the same manner as in Example 1 except that the amount of the antibacterial agent (B1) used was changed from “0.001 part” to “0.5 part”.

<Example 5>
A water absorbent resin composition (5) was obtained in the same manner as in Example 1 except that the amount of the antibacterial agent (B1) used was changed from “0.001 part” to “0.8 part”.

<Example 6>
A water-absorbent resin composition (6) was obtained in the same manner as in Example 1 except that the amount of the antibacterial agent (B1) used was changed from “0.001 part” to “1 part”.

<Example 7>
Other than changing “antibacterial agent (B1) 0.001 part” to “antibacterial agent (B2) {di-n-decyldimethylammonium chloride: cation DDC-50, manufactured by Sanyo Chemical Industries, Ltd.} 0.01 part” In the same manner as in Example 1, a water absorbent resin composition (7) was obtained.

<Example 8>
A water-absorbent resin composition (8) was obtained in the same manner as in Example 1, except that "0.001 part of the antibacterial agent (B1)" was changed to "0.1 part of the antibacterial agent (B2)".

<Example 9>
A water absorbent resin composition (9) was obtained in the same manner as in Example 1, except that "0.001 part of the antibacterial agent (B1)" was changed to "0.3 part of the antibacterial agent (B2)".

<Example 10>
A water-absorbent resin composition (10) was obtained in the same manner as in Example 1, except that “0.001 part of the antibacterial agent (B1)” was changed to “0.5 part of the antibacterial agent (B2)”.

<Example 11>
A water absorbent resin composition (11) was obtained in the same manner as in Example 1, except that "0.001 part of the antibacterial agent (B1)" was changed to "0.8 part of the antibacterial agent (B2)".

<Example 12>
A water absorbent resin composition (12) was obtained in the same manner as in Example 1, except that "0.001 part of the antibacterial agent (B1)" was changed to "1 part of the antibacterial agent (B2)".

<Example 13>
Changed “Water Absorbent Resin Particles (A1)” to “Water Absorbent Resin Particles (A2)” and changed the usage of “Antimicrobial Agent (B1)” from “0.001 part” to “0.3 part” A water-absorbent resin composition (13) was obtained in the same manner as in Example 1 except that.

<Example 14>
Changed “Water Absorbent Resin Particles (A1)” to “Water Absorbent Resin Particles (A3)” and changed the usage of “Antimicrobial Agent (B1) from“ 0.001 part ”to“ 0.3 part ” Except having carried out, it carried out similarly to Example 1, and obtained the water absorbing resin composition (14).

<Comparative Example 1>
100 parts of water-absorbing resin particles (A1), 5 parts of powdering modifier {Epomin P-1000 (manufactured by Nippon Shokubai Co., Ltd.), and 5 parts of Flowsen UF-1.5 (manufactured by Sumitomo Seika Co., Ltd.) Homogeneous mixture} and 0.1 part were uniformly mixed with a table kneader (PN-1 type, manufactured by Irie Shokai Co., Ltd.) to obtain a comparative water absorbent resin composition (H1).

<Comparative Example 2>
Comparative water-absorbent resin composition (H2) in the same manner as in Comparative Example 1, except that “powdering modifier 0.1 part” was changed to “liquid modifier {Epomin P-1050} 1 part”. Got.

<Comparative Example 3>
After reacting 56 parts of methanol, 274 parts (0.88 mole part) of di-n-decylmethylamine and 189 parts (1.6 mole part) of diethyl carbonate at 120 ° C. for 20 hours, methanol and diethyl carbonate were distilled off. The concentration was adjusted to 70% by weight to obtain a methanol solution of di-n-decylmethylethylammonium methyl carbonate.

  While maintaining a mixed aqueous solution composed of 157 parts (0.4 mole part) of 50% by weight gluconic acid aqueous solution and 300 parts of water at 80 to 90 ° C., 70% by weight di-n-decylmethylethylammonium methyl was added to this mixed aqueous solution. Carbonate methanol solution 237 parts (0.4 mol part) was added over 2 hours, carbon dioxide generated was removed, solvent (water and methanol) was distilled off, antibacterial agent (HB1) {di n-decyl Methyl ethyl ammonium gluconate} was obtained.

  100 parts of water-absorbent resin particles (A1) and antibacterial agent (HB1) {di-n-decylmethylethylammonium gluconate} 0.3 parts are uniformly mixed in a conical blender (manufactured by Hosokawa Micron Corporation) for comparison. Water absorbent resin composition (H3) was obtained.

<Comparative example 4>
After reacting 56 parts of methanol, 298 parts (0.88 mole part) of di-n-undecylmethylamine and 144 parts (1.6 mole part) of dimethyl carbonate at 120 ° C. for 20 hours, methanol and dimethyl carbonate were distilled off. The concentration was adjusted to 70% by weight to obtain a methanol solution of di-n-undecyldimethylammonium methyl carbonate.

  While maintaining a mixed aqueous solution composed of 157 parts (0.4 mol part) of 50% by weight gluconic acid aqueous solution and 300 parts of water at 80 to 90 ° C., 70% by weight di-n-undecyldimethylammonium methyl was added to this mixed aqueous solution. Carbonate methanol solution 245 parts (0.4 mol part) was added over 2 hours, carbon dioxide generated was removed, solvent (water and methanol) was distilled off, antibacterial agent (HB2) {di-n-un Decyldimethylammonium gluconate} was obtained.

  100 parts of water-absorbing resin particles (A2) and 0.5 part of antibacterial agent (HB2) {di-undecyldimethylammonium gluconate} are uniformly mixed with a conical blender (manufactured by Hosokawa Micron Corporation) for comparison. Water absorbent resin composition (H4) was obtained.

<Comparative Example 5>
By reacting 171 parts (1 mole part) of n-nonyldimethylamine and 162.5 parts (1 mole part) of n-nonyl chloride at 90 ° C., a comparative antibacterial agent (HB3) {di-n-nonyldimethylammonium chloride }.

  Water absorbing resin particles (A3) 100 parts and antibacterial agent (HB3) {di-n-nonyldimethylammonium chloride} 0.5 parts are uniformly mixed with a conical blender (manufactured by Hosokawa Micron Co., Ltd.) for water absorption for comparison. A resin composition (H5) was obtained.

<Comparative Example 6>
By reacting 171 parts (1 mole part) of n-nonyldimethylamine and 222.9 parts (1 mole part) of n-decyl bromide at 90 ° C., a comparative antibacterial agent (HB4) {n-decyl n-nonyldimethyl Ammonium bromide} was obtained.

  100 parts of the water-absorbent resin particles (A1) and 0.3 part of the antibacterial agent (HB4) {n-decyl n-nonyldimethylammonium bromide} are uniformly mixed with a conical blender (manufactured by Hosokawa Micron Corporation) for comparison. A water absorbent resin composition (H6) was obtained.

  With respect to the water-absorbent resin compositions (1) to (14) and (H1) to (H6), the water retention amount, powder flowability and antibacterial properties were evaluated by the following methods, and these results are shown in Table 1.

<Water retention amount>
1.00 g of a measurement sample is placed in a tea bag (20 cm long, 10 cm wide) made of a nylon mesh (JIS Z8801-1: 2006) having a nominal aperture of 63 μm, and physiological saline (saline concentration 0.9% by weight) 1, After being immersed in 000 cc for 1 hour without stirring, it was suspended for 15 minutes to drain water. Thereafter, each tea bag was placed in a centrifuge, centrifuged at 150 G for 90 seconds to remove excess physiological saline, and the weight (h1) including the tea bag was measured to obtain the water retention amount from the following formula. The physiological saline used and the temperature of the measurement atmosphere were 25 ° C. ± 2 ° C.

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

(H2) is the weight of the tea bag measured by the same operation as described above when there is no measurement sample.

<Powder flowability>
The angle of repose was determined using a powder tester (manufactured by Hosokawa Micron Corporation, a sieve having a nominal opening of 710 μm), and this angle of repose was defined as powder flowability. The larger the angle of repose, the worse the powder fluidity.

<Antimicrobial properties>
After dissolving 3.45 g of sensitive broth medium and 150 ml of water in a 300 cc flask, the medium was prepared by autoclaving. After adding 1.0 g of a measurement sample to this medium and stirring (the measurement sample absorbed water and swollen), Escherichia coli was inoculated so that the initial strain number was 1 × 10 ⁶ cells / ml. This sample was cultured with shaking at 37 ° C., sampled after 2 hours and 10 hours, and diluted 100-fold with sterile saline.

  After 1 ml of this diluted product was put into a sterile petri dish, 20 ml of agar medium was poured, and the dispersion was uniformly dispersed and solidified on the petri dish and cultured at 37 ° C. for 2 days in an air atmosphere. After culturing, the colonies were counted, and the number of viable strains was obtained by multiplying the dilution factor. The number of viable strains was measured by a mixed plane culture method.

On the other hand, the number of viable strains when cultured in the same manner as above except that no measurement sample was added as a blank was 5 × 10 ⁸ cells / ml after 2 hours and 6 × 10 ⁹ cells / ml after 10 hours. ml.

Antibacterial activity was evaluated in the same manner as described above except that E. coli (initial strain number 1 × 10 ⁶ cells / ml) was changed to ammonia-producing bacteria (initial strain number 1 × 10 ⁷ cells / ml). On the other hand, the number of viable strains when no measurement sample was added as a blank was 8 × 10 ⁷ cells / ml after 2 hours and 4 × 10 ⁹ cells / ml after 10 hours.

<Example 15>
A mixture obtained by mixing 100 parts of fluff pulp and 100 parts of the water-absorbent resin composition (1) obtained in Example 1 with an airflow type mixing device {Padformer manufactured by Autech Co., Ltd.} has a basis weight of about 400 g / m. ² was uniformly laminated on a sheet made of nylon net having a mesh size of 63 μm, and pressed at a pressure of 5 kg / cm ² for 30 seconds to obtain an absorbent body (K1).
Absorbent body (K1) is cut into a 40cm x 30cm rectangle, and the same size (14cm x 36cm) water absorbent paper (basis weight 15.5g / m ² : manufactured by Advantech Toyo Co., Ltd., filter paper No. 2) After sandwiching the two sheets, a polyethylene sheet (polyethylene film UB-1, manufactured by Tamapoly Co., Ltd., 14 cm × 36 cm) is further provided on the back surface, and a nonwoven fabric (basis weight 20.0 g / m ² , 14 cm × 36 cm: manufactured by Asahi Kasei Co., Ltd.) One absorptive article (1) was created by arranging (Eltus guard) on the surface.

<Examples 16 to 28>
Except having changed "water-absorbent resin composition (1)" into "any of water-absorbent resin compositions (2)-(14)", it carried out similarly to Example 15, and absorber (K2)-( K14) was prepared, and absorbent articles (2) to (14) were prepared.

<Comparative Examples 7-12>
Except that the “water absorbent resin composition (1)” was changed to “any of the water absorbent resin compositions (H1) to (H6)”, in the same manner as in Example 15, the absorbent bodies (HK1) to ( HK6) was prepared, and further absorbent articles (H1) to (H6) were prepared.

  For the absorbent articles (1) to (14) and (H1) to (H6), the foul odor prevention test was performed by the following method, and the results are shown in Table 2.

<Odor test>
After adding 80 ml of fresh urine to the center of the measurement sample (absorbent article) and absorbing it, it was sealed in a 5 liter jar and stored in a thermostat set at 40 ° C. for 10 hours. Thereafter, the lid of the wide-mouth bottle was opened in the odorless room to smell the odor, and the odor intensity was evaluated in the following six stages. Evaluation was carried out by 10 panelists whose odor judging ability was confirmed by the T & T olfactometer method, and the average value of 10 persons was obtained.
As fresh urine, dog urine provided by an animal hospital was used.

0: Odorless 1: Odor that can be finally detected (Sensitive Iki Value Concentration)
2: Weak odor that understands what kind of odor (recognized Iki value concentration)
3: Smell that can be easily detected 4: Strong smell 5: Strong smell

Claims (4)

A water absorbent resin composition comprising water absorbent resin particles (A) and an antibacterial agent (B), wherein the antibacterial agent (B) is an ammonium salt represented by the general formula (1).

(R ¹ ) ₂ N ⁺ (R ² ) ₂ X ⁻ (1)

[R ¹ is an n-decyl group, R ² is a methyl group, and X ⁻ is a chloride ion or a gluconate anion. ]   The water absorbent resin composition according to claim 1, wherein the content of the antibacterial agent (B) is 0.001 to 1% by weight based on the weight of the water absorbent resin particles (A).   An absorbent comprising the water-absorbent resin composition according to claim 1 or 2 and fibers.   An absorbent article comprising the absorbent body according to claim 3.