JP7250441B2 - Water absorbent resin particles and absorbent article - Google Patents

Description

The present invention relates to water absorbent resin particles and absorbent articles. More specifically, disposable diapers for children, disposable diapers for adults, napkins, blood retainers for medical use, pet sheets, panty liners, incontinence pads, sweat absorbing sheets, blood absorbent articles for medical use, wound protection materials, wound healing agents, and surgical waste fluids. The present invention relates to an absorbent article used as a treatment agent or the like and water absorbent resin particles suitable for producing the article.

Water-absorbent resins are required to have various functions and high physical properties as the performance of paper diapers, which is their main use, is improved. Specifically, such functions (physical properties) include gel strength, water-soluble matter, water content, water absorption speed, liquid permeability, particle size, in addition to the basic physical properties of water absorption capacity without pressure and water absorption capacity under pressure. distribution, urine resistance, antibacterial properties, damage resistance, powder fluidity, deodorizing properties, color resistance, low dust, low residual monomers, and the like.

Among the above functions (physical properties), in recent years, it has been required to add functions such as “deodorant” and “antibacterial” to water-absorbent resins. Addition of compounds to water absorbent resins has been investigated.

Specifically, a long-lasting antibacterial deodorant (Patent Document 1) consisting of a wasabi extract, mustard extract, etc., and an antibacterial deodorizing agent (water-absorbing gelling agent), a water-absorbent resin, and ammonia production A powdery deodorant/antibacterial water-absorbing agent composed of a compound having antibacterial function against bacteria and a drug having neutralizing ability or neutralizing ability and adsorption ability to ammonia (Patent Document 2) has been proposed. ing.

In addition, as a water-absorbing resin composition (water-absorbing agent) imparted with deodorizing and antibacterial functions and a method for producing the same, a method for forming an antibacterial coating on the surface of the water-absorbing resin (Patent Document 3), antibacterial phosphoric acid A water-absorbing resin composition containing salt (Patent Documents 4 and 5), a water-absorbing agent containing a natural antibacterial component extracted from grapefruit seeds and/or herbs (Patent Document 6), an antibacterial agent and a polyol during or after surface treatment A production method (Patent Document 7) and the like in which are added together have been proposed.

Furthermore, as a highly safe water-absorbing agent having antibacterial (bacteriostatic) and deodorant functions, a water-absorbent resin composition (Patent Document 8) in which a reflux extract of bamboo and green tea is blended with a water-absorbent resin has been proposed. ing.

On the other hand, as an attempt to impart a deodorant function and an antibacterial function to absorbent articles, disposable diapers using a water-absorbing resin containing benzalkonium chloride and/or chlorhexacidine gluconate (Patent Document 9) have been proposed. It is

However, all of these methods have focused on the odor generated during use of paper diapers, and have not paid attention to the odor generated during disposal after use of paper diapers.

In addition, even if the deodorant, antibacterial agent, and antifungal agent to be used are effective by themselves, the effect is weak when added to the water-absorbing resin, and some are completely ineffective, making selection easy. Rather, there has been a demand for an agent that is highly effective even when added to a water-absorbing resin.

JP-A-2000-51339 JP-A-2000-79159 JP-A-3-59075 JP-A-5-179053 JP-A-7-165981 JP-A-9-208787 Japanese Patent Application Publication No. 2010-540004 WO 2009/048145 pamphlet JP-A-63-135501

An object of the present invention is to provide water-absorbing resin particles that exhibit excellent deodorizing performance and antifungal performance both during use of absorbent articles such as disposable diapers and during disposal after use.

The present invention provides a crosslinked polymer (A) comprising a water-soluble vinyl monomer (a1) and/or a vinyl monomer (a2) that becomes a water-soluble vinyl monomer (a1) by hydrolysis, and a cross-linking agent (b) as essential constituent units. A water absorbent resin particle containing an organic iodine antifungal agent (B) (hereinafter also referred to as a water absorbent resin particle (P)), an absorbent body and an absorbent article using the same.

In the absorbent article of the present invention, since the absorbent body contains the absorbent resin particles (P) having the organic iodine antifungal agent (B), the liquid to be absorbed (body fluids such as sweat, urine and blood, and seawater) , underground water, muddy water, etc.), it has excellent antibacterial and antifungal properties. The excellent antibacterial and antifungal properties suppress the offensive odor of the absorbent article after use, making it possible to suppress the growth of mold even after disposal. By using the water-absorbing resin particles of the present invention in absorbent articles such as paper diapers, the absorbent article can be used comfortably without the odor generated after swelling during actual use, and the absorbent article can be disposed of. Odors and mold can be suppressed even during final processing, specifically when collecting garbage.

The water-absorbent resin particles (P) of the present invention comprise a water-soluble vinyl monomer (a1) and/or a vinyl monomer (a2) that becomes a water-soluble vinyl monomer (a1) by hydrolysis (hereinafter referred to as a hydrolyzable vinyl monomer (a2)). ) and a crosslinked polymer (A) containing a crosslinking agent (b) as an essential structural unit and an organic iodine antifungal agent (B).

The crosslinked polymer (A) possessed by the water absorbent resin particles (P) comprises water-soluble vinyl monomer (a1) and/or hydrolyzable vinyl monomer (a2) and crosslinking agent (b) as essential structural units.

The water-soluble vinyl monomer (a1) in the present invention is not particularly limited. vinyl monomers having saturated groups (e.g., anionic vinyl monomers, nonionic vinyl monomers and cationic vinyl monomers), anionic vinyl monomers disclosed in paragraphs 0009 to 0024 of JP-A-2003-165883, nonionic a carboxy group, a sulfo group, a phosphono group, a hydroxyl group, a carbamoyl group, an amino group and an ammonio group disclosed in paragraphs 0041 to 0051 of JP-A-2005-75982; Any vinyl monomer having at least one of the following can be used.

The hydrolyzable vinyl monomer (a2) is not particularly limited, and includes at least one hydrolyzable substituent that becomes a water-soluble substituent upon hydrolysis as disclosed in Japanese Patent No. 3648553, paragraphs 0024 to 0025. at least one hydrolyzable substituent [1,3-oxo-2-oxapropylene (-CO-O-CO- ) groups, acyl groups, cyano groups, etc.] can be used. The term "water-soluble vinyl monomer" is a concept well known to those skilled in the art, but if expressed in terms of quantity, it means, for example, a vinyl monomer that dissolves in 100 g of water at 25° C. in an amount of at least 100 g. In addition, the hydrolyzability of the hydrolyzable vinyl monomer (a2) is a concept well known to those skilled in the art. It means the property of being hydrolyzed and becoming water soluble. The hydrolysis of the hydrolyzable vinyl monomer (a2) may be carried out during polymerization, after polymerization, or both, but from the viewpoint of the absorption performance of the resulting water-absorbent resin particles, it is preferably carried out after polymerization.

Among these, the water-soluble vinyl monomer (a1) is preferable from the viewpoint of absorption performance and the like, and more preferable are the above-mentioned anionic vinyl monomers, carboxy (salt) group, sulfo (salt) group, amino group, carbamoyl group, A vinyl monomer having an ammonio group or a mono-, di- or tri-alkylammonio group, more preferably a vinyl monomer having a carboxy (salt) group or a carbamoyl group, particularly preferably a (meth)acrylic acid (salt) and (Meth)acrylamide, especially preferred (meth)acrylic acid (salt), most preferred acrylic acid (salt).

In addition, "carboxy (salt) group" means "carboxy group" or "carboxylate group", and "sulfo (salt) group" means "sulfo group" or "sulfonate group". (Meth)acrylic acid (salt) means acrylic acid, acrylate, methacrylic acid or methacrylate, and (meth)acrylamide means acrylamide or methacrylamide. Examples of salts include alkali metal (lithium, sodium, potassium, etc.) salts, alkaline earth metal (magnesium, calcium, etc.) salts, ammonium (NH ₄ ) salts, and the like. Among these salts, alkali metal salts and ammonium salts are preferable, alkali metal salts are more preferable, and sodium salts are particularly preferable, from the viewpoint of absorption performance and the like.

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

In addition to the water-soluble vinyl monomer (a1) and the hydrolyzable vinyl monomer (a2), other vinyl monomers (a3) copolymerizable therewith are used as structural units of the crosslinked polymer (A). can be done. Other vinyl monomers (a3) may be used alone or in combination of two or more.

Other copolymerizable vinyl monomers (a3) are not particularly limited, and are known (for example, hydrophobic vinyl monomers disclosed in paragraphs 0028 to 0029 of Japanese Patent No. 3648553, Japanese Patent Laid-Open No. 2003-165883, 0025 paragraph and the vinyl monomers disclosed in JP-A-2005-75982 paragraph 0058) can be used, and specifically, for example, the following vinyl monomers (i) to (iii), etc. can be used.
(i) Aromatic ethylenic monomer having 8 to 30 carbon atoms Styrene such as styrene, α-methylstyrene, vinyltoluene and hydroxystyrene, and halogen-substituted styrene such as vinylnaphthalene and dichlorostyrene.
(ii) Aliphatic ethylenic monomers having 2 to 20 carbon atoms Alkenes (ethylene, propylene, butene, isobutylene, pentene, heptene, diisobutylene, octene, dodecene, octadecene, etc.); and alkadienes (butadiene, isoprene, etc.).
(iii) C5-C15 alicyclic ethylenic monomers monoethylenically unsaturated monomers (pinene, limonene, indene, etc.); and polyethylene vinyl monomers [cyclopentadiene, bicyclopentadiene, ethylidenenorbornene, etc.], and the like.

The content (mol %) of the other vinyl monomer (a3) units is, from the viewpoint of absorption performance and the like, based on the total number of moles of the water-soluble vinyl monomer (a1) units and the hydrolyzable vinyl monomer (a2) units. It is preferably 0 to 5, more preferably 0 to 3, particularly preferably 0 to 2, and most preferably 0 to 1.5. From the viewpoint of absorption performance etc., the content of other vinyl monomer (a3) units is 0 mol % is most preferred.

The cross-linking agent (b) is not particularly limited and is known (for example, a cross-linking agent having two or more ethylenically unsaturated groups disclosed in paragraphs 0031 to 0034 of Japanese Patent No. 3648553, which reacts with a water-soluble substituent. A cross-linking agent having at least one functional group and having at least one ethylenically unsaturated group and a cross-linking agent having at least two functional groups capable of reacting with a water-soluble substituent, JP-A-2003-165883 Cross-linking agents having two or more ethylenically unsaturated groups disclosed in paragraphs 0028 to 0031, cross-linking agents having ethylenically unsaturated groups and reactive functional groups, and cross-linking agents having two or more reactive substituents , the crosslinkable vinyl monomers disclosed in paragraph 0059 of JP-A-2005-75982 and the crosslinkable vinyl monomers disclosed in paragraphs 0015-0016 of JP-A-2005-95759) can be used. . Among these, from the viewpoint of absorption performance and the like, cross-linking agents having two or more ethylenically unsaturated groups are preferable, and more preferable are triallyl cyanurate, triallyl isocyanurate and polyols having 2 to 40 carbon atoms ( Meta)allyl ethers, particularly preferred are triallyl cyanurate, triallyl isocyanurate, tetraallyloxyethane, polyethylene glycol diallyl ether and pentaerythritol triallyl ether, most preferred is pentaerythritol triallyl ether. The crosslinking agent (b) may be used alone or in combination of two or more.

The content (mol %) of the cross-linking agent (b) units is the water-soluble vinyl monomer (a1) units and the hydrolyzable vinyl monomer (a2) units, and when other vinyl monomers (a3) are also used, (a1) Based on the total number of moles of (a3), it is preferably 0.001 to 5, more preferably 0.005 to 3, and particularly preferably 0.01 to 1. Within this range, the absorption performance is further improved.

As the polymerization method of the crosslinked polymer (A), known solution polymerization (adiabatic polymerization, thin film polymerization, spray polymerization, etc.; JP-A-55-133413, etc.) and known reverse phase suspension polymerization 54-30710, JP-A-56-26909 and JP-A-1-5808).

The crosslinked polymer (A) is obtained by polymerizing a monomer composition comprising a water-soluble vinyl monomer (a1) and/or a hydrolyzable vinyl monomer (a2) and a crosslinking agent (b) as essential components. can be done. Of the polymerization methods, the solution polymerization method is preferable, and the aqueous solution polymerization method and the reversed-phase suspension polymerization method are more preferable, since they do not require the use of an organic solvent or the like and are advantageous in terms of production cost.

When carrying out aqueous polymerization, a mixed solvent containing water and an organic solvent can be used. and mixtures of
When aqueous solution polymerization is carried out, the amount (% by weight) of the organic solvent used is preferably 40 or less, more preferably 30 or less, based on the weight of water.

When an initiator is used for polymerization, conventionally known initiators for radical polymerization can be used. hydrochloride, etc.], inorganic peroxides (hydrogen peroxide, ammonium persulfate, potassium persulfate, sodium persulfate, etc.), organic peroxides [benzoyl peroxide, di-t-butyl peroxide, cumene hydroperoxide, succinate acid peroxides and di(2-ethoxyethyl)peroxydicarbonate, etc.] and redox catalysts (alkali metal sulfites or bisulfites, reducing agents such as ammonium sulfite, ammonium bisulfite and ascorbic acid and alkali metal persulfates salts, ammonium persulfate, hydrogen peroxide, organic peroxides, etc.). These catalysts may be used alone, or two or more of them may be used in combination.
The amount (% by weight) of the radical polymerization initiator used is the water-soluble vinyl monomer (a1) and the hydrolyzable vinyl monomer (a2), or (a1) to (a3) when another vinyl monomer (a3) is also used. , preferably 0.0005 to 5, more preferably 0.001 to 2, based on the total weight.

At the time of polymerization, a polymerization control agent represented by a chain transfer agent may be used in combination as necessary. Specific examples thereof include sodium hypophosphite, sodium phosphite, alkyl mercaptans, alkyl halides. , thiocarbonyl compounds and the like. These polymerization control agents may be used alone, or two or more of them may be used in combination.
The amount (% by weight) of the polymerization control agent used is the water-soluble vinyl monomer (a1) and the hydrolyzable vinyl monomer (a2), or (a1) to (a3) when the other vinyl monomer (a3) is also used. , preferably 0.0005 to 5, more preferably 0.001 to 2, based on the total weight.

When a suspension polymerization method or a reverse-phase suspension polymerization method is employed as the polymerization method, polymerization may be carried out in the presence of a dispersant or surfactant, if necessary. Moreover, in the case of the reversed-phase suspension polymerization method, the polymerization can be carried out using a hydrocarbon solvent such as xylene, normal hexane and normal heptane.

The polymerization initiation temperature can be appropriately adjusted depending on the type of catalyst used, but is preferably 0 to 100°C, more preferably 2 to 80°C.

When a solvent (organic solvent, water, etc.) is used for polymerization, it is preferred to distill off the solvent after polymerization. When the solvent contains an organic solvent, the content (% by weight) of the organic solvent after distillation is preferably 0 to 10, more preferably 0 to 5, particularly preferably 0 to 5, based on the weight of the crosslinked polymer (A). is 0-3, most preferably 0-1. Within this range, the absorption performance of the water absorbent resin particles is further improved.

When the solvent contains water, the water content (% by weight) after distillation is preferably 0 to 20, more preferably 1 to 10, particularly preferably 2 to 9, based on the weight of the crosslinked polymer (A). Most preferably 3-8. Within this range, the absorption performance is further improved.

By the above polymerization method, the crosslinked polymer (A) can obtain a water-containing gel-like material (that is, the crosslinked polymer (A) which is a water-containing gel-like material; hereinafter abbreviated as a water-containing gel), Further, by drying the hydrous gel, a dry crosslinked polymer (A) can be obtained.
When using an acid group-containing monomer such as acrylic acid or methacrylic acid as the water-soluble vinyl monomer (a1), the water-containing gel may be neutralized with a base. The degree of neutralization of acid groups is preferably 50 to 80 mol %. If the degree of neutralization is less than 50 mol %, the resulting hydrous gel polymer will have high adhesiveness, and workability during production and use may deteriorate. Furthermore, the water-retaining capacity of the obtained water-absorbent resin particles may decrease. On the other hand, if the degree of neutralization exceeds 80%, the resulting resin will have a high pH and may be unsafe for human skin.
The neutralization may be carried out at any stage after the polymerization of the crosslinked polymer (A) in the production of the water-absorbent resin particles. exemplified.
As the neutralizing base, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and alkali metal carbonates such as sodium carbonate, sodium hydrogencarbonate and potassium carbonate can usually be used.

The hydrous gel obtained by polymerization can be chopped as needed. The size (maximum diameter) of the gel after shredding is preferably 50 μm to 10 cm, more preferably 100 μm to 2 cm, particularly preferably 1 mm to 1 cm. Within this range, the drying property in the drying step is further improved.

Shredding can be performed by a known method, and can be shredded using an ordinary shredding device {e.g., Vex mill, rubber chopper, farmer mill, mincing machine, impact pulverizer, and roll pulverizer}. .

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

After drying the hydrous gel to obtain the crosslinked polymer (A), it can be pulverized after drying. The method of pulverization is not particularly limited, and conventional pulverizers {eg, hammer pulverizer, impact pulverizer, roll pulverizer, jet stream pulverizer} and the like can be used. The pulverized crosslinked polymer can be adjusted in particle size by sieving or the like, if necessary.

The weight average particle size (μm) of the crosslinked polymer (A) when sieved as necessary is preferably 100 to 800, more preferably 200 to 700, next preferably 250 to 600, particularly preferably 300 to 500, Most preferably 350-450. Within this range, the absorption performance is further improved, and the entanglement with the hydrophilic fibers (C) is improved, resulting in good shape retention.

In addition, the weight average particle size was measured using a low-tap test sieve shaker and a standard sieve (JIS Z8801-1: 2006) according to Perry's Chemical Engineers Handbook 6th Edition (McGrow Hill Book Company, 1984). , page 21). That is, JIS standard sieves of 1000 μm, 850 μm, 710 μm, 500 μm, 425 μm, 355 μm, 250 μm, 150 μm, 125 μm, 75 μm and 45 μm and a saucer are combined in this order from the top. About 50 g of the particles to be measured are placed in the top sieve and shaken for 5 minutes with a Rotap test sieve shaker. The weight of the particles to be measured on each sieve and the tray is weighed, the total is 100% by weight, and the weight fraction of the particles on each sieve is obtained. ) and weight fraction} on the vertical axis, draw a line connecting each point, determine the particle diameter corresponding to a weight fraction of 50% by weight, and take this as the weight average particle diameter.

In addition, when pulverized, the smaller the content of fine particles contained in the crosslinked polymer (A) after pulverization, the better the absorption performance. below) is preferably 3 or less, more preferably 1 or less. The content of fine particles can be determined using the graph created when determining the weight-average particle size.

When pulverized, the shape of the crosslinked polymer (A) after pulverization is not particularly limited, and examples thereof include irregularly pulverized, scale-like, pearl-like, and rice grain-like. Among these, the irregular crushed shape is preferable from the viewpoint of good entanglement with the fibrous material and no fear of falling off from the fibrous material.

The crosslinked polymer (A) may contain a small amount of other components such as a residual solvent and a residual crosslinked component within a range that does not impair its performance.

The crosslinked polymer (A) preferably contains a hydrophobic substance (g) from the viewpoint of surface modification and liquid permeability.

The hydrophobic substance (g) includes a hydrophobic substance (g1) containing a hydrocarbon group, a hydrophobic substance (g2) containing a hydrocarbon group having a fluorine atom, and a hydrophobic substance (g3) having a polysiloxane structure. etc. are included.

Hydrophobic substances (g1) containing hydrocarbon groups include polyolefin resins, polyolefin resin derivatives, polystyrene resins, polystyrene resin derivatives, waxes, long-chain fatty acid esters, long-chain fatty acids and their salts, long-chain aliphatic alcohols, long-chain Chain fatty amides and mixtures of two or more thereof are included.

As the polyolefin resin, the weight of an olefin having 2 to 4 carbon atoms {ethylene, propylene, isobutylene, isoprene, etc.} as an essential constituent monomer (the content of the olefin is at least 50% by weight based on the weight of the polyolefin resin). Polymers having an average molecular weight of 1,000 to 1,000,000 {eg, polyethylene, polypropylene, polyisobutylene, poly(ethylene-isobutylene), isoprene, etc.} can be mentioned.

Polyolefin resin derivatives include polymers with a weight average molecular weight of 1,000 to 1,000,000 obtained by introducing a carboxy group (-COOH) or 1,3-oxo-2-oxapropylene (-COOCO-) into a polyolefin resin {for example, polyethylene heat Degraded product, polypropylene heat degraded product, maleic acid-modified polyethylene, chlorinated polyethylene, maleic acid-modified polypropylene, ethylene-acrylic acid copolymer, ethylene-maleic anhydride copolymer, isobutylene-maleic anhydride copolymer, maleated polybutadiene, ethylene-vinyl acetate copolymer, maleated ethylene-vinyl acetate copolymer, etc.}.

A polymer having a weight average molecular weight of 1,000 to 1,000,000 can be used as the polystyrene resin.

As the polystyrene resin derivative, a polymer having a weight average molecular weight of 1,000 to 1,000,000 containing styrene as an essential constituent monomer (the styrene content is at least 50% by weight based on the weight of the polystyrene derivative) {for example, styrene- maleic anhydride copolymer, styrene-butadiene copolymer, styrene-isobutylene copolymer, etc.}.

Waxes include waxes having a melting point of 50 to 200° C. {eg, paraffin wax, beeswax, carnauba wax, beef tallow, etc.}.

Examples of long-chain fatty acid esters include esters of fatty acids having 8 to 30 carbon atoms and alcohols having 1 to 12 carbon atoms {for example, methyl laurate, ethyl laurate, methyl stearate, ethyl stearate, methyl oleate, oleic acid, Ethyl, glycerol monolaurate, glycerine monostearate, monoglycerol oleate, pentaerythrityl monolaurate, pentaerythrityl monostearate, pentaerythrityl monooleate, sorbitol monolaurate, Sorbit monostearate, sorbitol monooleate, sucrose palmitate monoester, sucrose palmitate diester, sucrose palmitate triester, sucrose stearate monoester, sucrose stearate diester, sucrose tristearate ester and beef tallow, etc.].

Examples of long-chain fatty acids and salts thereof include fatty acids having 8 to 30 carbon atoms {eg, lauric acid, palmitic acid, stearic acid, oleic acid, dimer acid, behenic acid, etc.}, and salts thereof include zinc, calcium, Salts with magnesium or aluminum (hereinafter abbreviated as Zn, Ca, Mg, Al, respectively) {eg, Ca palmitate, Al palmitate, Ca stearate, Mg stearate, Al stearate, etc.}.

Long-chain fatty alcohols include fatty alcohols having 8 to 30 carbon atoms {eg, lauryl alcohol, palmityl alcohol, stearyl alcohol, oleyl alcohol, etc.}. Palmityl alcohol, stearyl alcohol, and oleyl alcohol are preferable, and stearyl alcohol is more preferable, from the viewpoint of anti-leakage property of the absorbent article.

Examples of long-chain aliphatic amides include amidates of long-chain aliphatic primary amines with 8 to 30 carbon atoms and carboxylic acids having a hydrocarbon group with 1 to 30 carbon atoms, ammonia, or primary amines with 1 to 7 carbon atoms. and an amide of a long-chain fatty acid having 8 to 30 carbon atoms, an amide of a long-chain aliphatic secondary amine having at least one aliphatic chain of 8 to 30 carbon atoms and a carboxylic acid having 1 to 30 carbon atoms, and Amidates of secondary amines having two aliphatic hydrocarbon groups of 1 to 7 carbon atoms and long-chain fatty acids of 8 to 30 carbon atoms can be mentioned.

As an amidated product of a long-chain aliphatic primary amine having 8 to 30 carbon atoms and a carboxylic acid having a hydrocarbon group having 1 to 30 carbon atoms, a product obtained by reacting the primary amine and carboxylic acid in a ratio of 1:1 and 1 : It is divided into the reacted products in 2. Examples of the 1:1 reaction product include N-octylamide acetate, N-hexacosylamide acetate, N-octylamide heptacosanoate and N-hexacosylamide heptacosanoate. Those reacted at 1:2 include N-octylamide diacetate, N-hexacosylamide diacetate, N-octylamide diheptacosanoate and N-hexacosylamide diheptacosanoate. In the case of a product obtained by reacting a primary amine and a carboxylic acid at a ratio of 1:2, the carboxylic acids used may be the same or different.

As an amidation product of ammonia or a primary amine having 1 to 7 carbon atoms and a long-chain fatty acid having 8 to 30 carbon atoms, a product obtained by reacting ammonia or a primary amine with a carboxylic acid at a ratio of 1:1 and a ratio of 1:2. It is divided into reactants. Nonanoic acid amide, nonanoic acid methylamide, nonanoic acid N-heptylamide, heptacosanoic acid amide, heptacosanoic acid N-methylamide, heptacosanoic acid N-heptylamide and heptacosanoic acid N-hexacosylamide etc. Dinonanoic acid amide, dinonanoic acid N-methylamide, dinonanoic acid N-heptylamide, dioctadecanoic acid amide, dioctadecanoic acid N-ethylamide, dioctadecanoic acid N-heptylamide, diheptacosanoic acid amide , diheptacosanoic acid N-methylamide, diheptacosanoic acid N-heptylamide and diheptacosanoic acid N-hexacosylamide. In addition, as a product obtained by reacting ammonia or a primary amine with a carboxylic acid at a ratio of 1:2, the carboxylic acids used may be the same or different.

Examples of the amidated product of a long-chain aliphatic secondary amine having at least one aliphatic chain having 8 to 30 carbon atoms and a carboxylic acid having 1 to 30 carbon atoms include N-methyloctylamide acetate and N-methylhexacosylate acetate. Acetate N-octylhexacosylamide, Acetate N-dihexacosylamide, Heptacosanoic acid N-methyloctylamide, Heptacosanoic acid N-methylhexacosylamide, Heptacosanoic acid N-octylhexacosylamide and Heptacosane and acid N-dihexacosylamide.

Examples of amidates of secondary amines having two aliphatic hydrocarbon groups of 1 to 7 carbon atoms and long-chain fatty acids of 8 to 30 carbon atoms include nonanoic acid N-dimethylamide, nonanoic acid N-methylheptylamide, nonanoic acid N-diheptylamide, heptacosanoic acid N-dimethylamide, heptacosanoic acid N-methylheptylamide, heptacosanoic acid N-diheptylamide and the like.

Hydrophobic substances (g2) containing a hydrocarbon group having a fluorine atom include perfluoroalkanes, perfluoroalkenes, perfluoroaryls, perfluoroalkyl ethers, perfluoroalkylcarboxylic acids, perfluoroalkyl alcohols and two of these. A mixture of more than one species is included.

Hydrophobic substances (g3) having a polysiloxane structure include polydimethylsiloxane, polyether-modified polysiloxane {polyoxyethylene-modified polysiloxane and poly(oxyethylene/oxypropylene)-modified polysiloxane, etc.}, carboxy-modified polysiloxane, Epoxy-modified polysiloxane, amino-modified polysiloxane, alkoxy-modified polysiloxane, etc. and mixtures thereof and the like are included.

The HLB value of the hydrophobic substance (g) is preferably 1-10, more preferably 2-8, and particularly preferably 3-7. Within this range, the anti-leak property of the absorbent article is further improved. In addition, the HLB value means the hydrophilic-hydrophobic balance (HLB) value, and is obtained by the Oda method (new introduction to surfactants, page 197, Takehiko Fujimoto, published by Sanyo Chemical Industries, Ltd., published in 1981). .

Of the hydrophobic substances (g), from the viewpoint of the resistance to leakage of the absorbent article, the hydrophobic substances (g1) containing a hydrocarbon group are preferred, more preferably long-chain fatty acid esters, long-chain fatty acids and salts thereof, long-chain fatty alcohols and long-chain fatty amides, more preferably sorbitol stearate, sucrose stearate, stearic acid, Mg stearate, Ca stearate, Zn stearate and Al stearate, particularly preferably Sucrose stearate and Mg stearate, most preferably sucrose monostearate.

The water absorbent resin particles of the present invention preferably have a structure in which the surface of the crosslinked polymer (A) is crosslinked by the surface crosslinking agent (d). By cross-linking the surface of the crosslinked polymer (A), the gel strength of the water-absorbent resin particles can be improved, and the desired water retention capacity and absorption under load of the water-absorbent resin particles can be satisfied. As the surface cross-linking agent (d), known (polyvalent glycidyl compounds, polyvalent amines, polyvalent aziridine compounds and polyvalent isocyanate compounds described in JP-A-59-189103, etc., JP-A-58-180233 And the polyhydric alcohol of JP-A-61-16903, the silane coupling agent described in JP-A-61-211305 and JP-A-61-252212, the JP-A-5-508425 described Alkylene carbonate, polyvalent oxazoline compounds described in JP-A-11-240959, and polyvalent metals described in JP-A-51-136588 and JP-A-61-257235) are used as surface cross-linking agents. can. Among these surface cross-linking agents, polyhydric glycidyl compounds, polyhydric alcohols and polyhydric amines are preferred from the viewpoint of economic efficiency and absorption properties, polyhydric glycidyl compounds and polyhydric alcohols are more preferred, and polyhydric alcohols are particularly preferred. A valent glycidyl compound, most preferred is ethylene glycol diglycidyl ether. One type of surface cross-linking agent may be used alone, or two or more types may be used in combination.

In the case of surface cross-linking, the amount (parts by weight) of the surface cross-linking agent used is not particularly limited because it can be varied depending on the type of surface cross-linking agent, cross-linking conditions, target performance, etc. However, there is no particular limitation. From the point of view, etc., it is preferably 0.001 to 3, more preferably 0.005 to 2, and particularly preferably 0.01 to 1.5, relative to 100 parts by weight of the crosslinked polymer (A).

Surface cross-linking of the cross-linked polymer (A) can be carried out by mixing the cross-linked polymer (A) and the surface cross-linking agent (d) and, if necessary, heating. Examples of the method for mixing the crosslinked polymer (A) and the surface cross-linking agent (d) include a cylindrical mixer, a screw mixer, a screw extruder, a turbulizer, a Nauta mixer, a twin-arm kneader, a fluid Crosslinked polymer (A) and surface crosslinking using a mixing device such as a mixer, a V-shaped mixer, a mincing mixer, a ribbon mixer, an airflow mixer, a rotating disc mixer, a conical blender and a roll mixer A method of uniformly mixing the agent (d) can be mentioned. At this time, the surface cross-linking agent (d) may be diluted with water and/or any solvent before use.

The temperature at which the crosslinked polymer (A) and the surface cross-linking agent (d) are mixed is not particularly limited, but is preferably 10 to 150°C, more preferably 20 to 100°C, and particularly preferably 25 to 80°C. .

After mixing the crosslinked polymer (A) and the surface cross-linking agent (d), heat treatment is performed. The heating temperature is preferably 100 to 180°C, more preferably 110 to 175°C, particularly preferably 120 to 170°C, from the viewpoint of breaking resistance of the resin particles. Heating at 180° C. or less enables indirect heating using steam, which is advantageous in terms of facilities. Heating temperatures below 100° C. may result in poor absorption performance. The heating time can be appropriately set depending on the heating temperature, but from the viewpoint of absorption performance, it is preferably 5 to 60 minutes, more preferably 10 to 40 minutes. It is also possible to further surface-crosslink the water-absorbing resin obtained by surface-crosslinking using a surface-crosslinking agent that is the same as or different from the surface-crosslinking agent used first.

After cross-linking the surface of the cross-linked polymer (A) with the surface-cross-linking agent (d), the particle size is adjusted by sieving if necessary. The average particle size of the obtained particles is preferably 100-600 μm, more preferably 200-500 μm. The content of fine particles is preferably as small as possible, the content of particles of 100 μm or less is preferably 3% by weight or less, and the content of particles of 150 μm or less is more preferably 3% by weight or less.

The water absorbent resin particles (P) contain a crosslinked polymer (A) and an organic iodine antifungal agent (B). Organic iodine antifungal agents (B) include 3-iodo-2-propynylbutylcarbamate, p-chlorophenyl-3-iodopropargyl formal, 1-[[(3-iodo-2-propynyl)oxy]methoxy]-4 -Methoxybenzene, 3-bromo-2,3-diiodo-2-propenylethyl carbonate, diiodomethyl-p-tolylsulfone and 1-(4-chlorophenyl)-3-iodopropargyl formal, etc., deodorizing and antifungal diiodomethyl-p-tolylsulfone is preferred from the viewpoint of compatibility.

The content of the organic iodine antifungal agent (B) in the water absorbent resin particles (P) can be adjusted according to the use of the water absorbent resin particles. It is preferably 0.001 to 10% by weight, more preferably 0.1 to 5% by weight, and most preferably 0.3 to 1% by weight, based on the total weight of the mold agent (B). be. Within this range, the absorbability and antifungal performance of the water-absorbent resin particles are improved, which is more preferable.

The water absorbent resin particles (P) can be obtained by mixing the crosslinked polymer (A) and the organic iodine antifungal agent (B). Mixing methods for the organic iodine antifungal agent (B) include a cylindrical mixer, a screw mixer, a screw extruder, a turbulizer, a Nauta mixer, a double-arm kneader, a fluid mixer, a V A method of uniform mixing using a known mixing device such as a type mixer, a mincing mixer, a ribbon type mixer, an air flow type mixer, a rotating disk type mixer, a conical blender and a roll mixer can be used.

For mixing the crosslinked polymer (A) and the organic iodine antifungal agent (B), it is preferable to add the organic iodine antifungal agent (B) to the crosslinked polymer (A) while stirring. The organic iodine antifungal agent (B) to be added may be added at the same time as water and/or solvent.
When the organic iodine anti-mold agent (B) is added simultaneously with water and / or a solvent, a solution of the organic iodine anti-mold agent (B) dissolved in water and / or a solvent, or the organic iodine anti-mold agent (B ) in water and/or a solvent is preferably added, and it is more preferable to add a dispersion from the viewpoint of workability and the like. When adding a solution or dispersion, it is preferably added by spraying or dropwise.

When using an aqueous solution in which the organic iodine antifungal agent (B) is dissolved in water, the content of the organic iodine antifungal agent (B) contained in the aqueous solution is 5 to 70% by weight based on the total weight of the aqueous solution. is preferred, and more preferably 10 to 60% by weight.

The aqueous solution obtained by dissolving the organic iodine antifungal agent (B) in water may be an aqueous solution obtained after the monomer composition is polymerized in water. For example, an aqueous solution obtained by dissolving in water by a method such as dissolving in water using a mixing vessel equipped with an impeller-type stirring device may be used.
In addition, the aqueous solution may contain additives such as arbitrary stabilizers as necessary. Stabilizers include, for example, commercially available chelating agents [diethylenetriamine (salt), triethylenetetramine (salt), ethylenediaminetetraacetic acid (salt), citric acid (salt), tartaric acid (salt), malic acid (salt), etc.] , commercially available inorganic reducing agents [sulfite (salt), hydrogen sulfite (salt), phosphorous acid (salt) and hypophosphorous acid (salt)], commercially available pH adjusters [phosphoric acid (salt), boric acid ( salts), alkali metals (salts) and alkaline earth metals (salts)], commercially available antioxidants [vitamin C (ascorbic acid), vitamin E (tocopherol), dibutylhydroxytoluene (also called BHT), butylhydroxyanisole (also referred to as BHA), sodium erythorbate, propyl gallate, sodium sulfite, etc.].

The temperature at which the crosslinked polymer (A) and the organic iodine antifungal agent (B) are mixed is not particularly limited, but is preferably 10 to 150°C, more preferably 20 to 100°C, and particularly preferably 25 to 80°C. is.

After mixing the crosslinked polymer (A) and the organic iodine antifungal agent (B), the mixture may be further heat-treated. The heating temperature is preferably 25 to 180°C, more preferably 30 to 175°C, particularly preferably 35 to 170°C, from the viewpoint of breaking resistance of the resin particles. If it is heated at 180° C. or less, indirect heating using steam is possible, which is advantageous in terms of facilities. Moreover, when the heating is not performed, the water and the solvent used in combination remain excessively in the water-absorbing resin, and the absorption performance may deteriorate.
When heating after mixing the crosslinked polymer (A) and the organic iodine antifungal agent (B), the heating time can be appropriately set depending on the heating temperature, but from the viewpoint of absorption performance, preferably 5 to 60 minutes. , more preferably 10 to 40 minutes. The water absorbent resin obtained by mixing the crosslinked polymer (A) and the organic iodine antifungal agent (B) is treated with an organic iodine antifungal agent of the same or different kind as the organic iodine antifungal agent (B) used first. It is also possible to further surface-treat using a mold agent (B).

The surface of the water absorbent resin particles (P) may be further coated with inorganic powder. Preferred inorganic powders include glass, silica gel, silica sol, silica, clay, carbon fiber, kaolin, talc, mica, bentonite, sericite, asbestos and shirasu. Among inorganic powders, silica sol, silica and talc are preferred.

The shape of the inorganic powder may be amorphous (crushed), spherical, film-like, rod-like or fibrous, preferably amorphous (crushed) or spherical, more preferably spherical. .

The content (% by weight) of the inorganic powder is preferably 0.01 to 3.0, more preferably 0.05 to 1.0, next preferably 0.05 to 1.0, based on the weight of the crosslinked polymer (A). 07 to 0.8, particularly preferably 0.10 to 0.6, most preferably 0.15 to 0.5. Within this range, the rash resistance of the absorbent article is further improved.

The water-absorbing resin particles (P) may contain other additives {for example, known antiseptic agents (Japanese Unexamined Patent Publication No. 2003-225565, Japanese Unexamined Patent Publication No. 2006-131767, etc.), antifungal agents, antibacterial agents, antioxidants, ultraviolet Absorbents, coloring agents, fragrances, deodorants, organic fibrous materials, etc.} may also be included. When these additives are contained, the content (% by weight) of the additives is preferably 0.001 to 10, more preferably 0.01 to 5, especially 0.01 to 5, based on the weight of the crosslinked polymer (A). It is preferably between 0.05 and 1, most preferably between 0.1 and 0.5.

The water-absorbent resin particles (P) are crosslinked polymer particles that absorb 40 times their own weight of physiological saline in 40 to 170 seconds, more preferably 55 to 120 seconds, and particularly preferably 70 to 100 seconds. preferable.
Within this range, the rash resistance of the absorbent article is further improved. By adjusting the content of the hydrophobic substance (g), the average particle size and the apparent density of the crosslinked polymer within the above preferable range, the absorption time of physiological saline can be adjusted within a preferable range, and the crosslinked polymer (A) can be By adjusting the apparent density, the weight average particle size, and the like within the above preferred ranges, it is possible to adjust them to more preferred ranges.
Incidentally, the physiological saline absorption time is the time measured by the following method in a room at 25±2° C. and 50±10% humidity. The temperature of the physiological saline solution to be used is adjusted in advance to 25°C ± 2°C.

The water retention capacity (g/g) of the water absorbent resin particles (P) is preferably 25 to 60, more preferably 26 to 55, and particularly preferably 27 to 50, from the viewpoint of anti-rash of the absorbent article. Incidentally, the water retention capacity of the crosslinked polymer particles is measured by the method described later.

The gel elastic modulus (N/m ² ) of a 30-fold swollen gel obtained by absorbing 30 parts by weight of artificial urine with 1 part by weight of the water-absorbing resin particles (P) is preferably 2,000 to 3,000, more preferably. is 2,025 to 2,950, particularly preferably 2,050 to 2,900, most preferably 2,075 to 2,850. Within this range, when the absorbent resin particles (P) of the present invention are applied to absorbent articles, more excellent leakage resistance is exhibited. In addition, the gel elastic modulus (N/m ² ) is a value obtained by a measuring method described later.

In the present invention, the absorbent refers to a structure containing water absorbent resin particles (P) and fibrous material. The absorber is a part that absorbs aqueous liquids, and examples of aqueous liquids include body fluids such as urine, sweat and blood, and aqueous liquids used for various purposes (industrial, medical, agriculture, forestry and fisheries, etc.). mentioned.

In the absorbent body of the present invention, the fibrous material is a member for diffusing the absorbed liquid, and examples thereof include hydrophilic fibers (C) and synthetic fibers. Hydrophilic fibers (C) include various fluff pulps, cotton-like pulps, etc., hydrophilic fibers conventionally used in absorbent articles {raw materials (soft and hardwoods, etc.), manufacturing methods [chemical pulp, semi-chemical pulp and Chemi-thermomechanical pulp (CTMP), etc.]} and sheet-like materials such as tissues are not particularly limited in terms of form. Synthetic fibers can be used alone or in combination with the fluff pulp or cotton-like pulp described above, and may be in the form of a non-woven sheet. Synthetic fibers include polyolefin fibers (polyethylene fibers, polypropylene fibers, etc.), polyester fibers (polyethylene terephthalate fibers, etc.), polyolefin/polyester composite fibers, polyamide fibers, polyacrylonitrile fibers, and the like.

The length and thickness of the hydrophilic fiber (C) are not particularly limited, and the preferred range is usually 1 to 200 mm in length and 0.1 to 100 denier (0.11 to 110 dtex) in thickness. The shape is not particularly limited as long as it is fibrous, and examples thereof include a web shape, a thin cylindrical shape, a cut split yarn shape, a staple shape and a filament shape.

In the absorbent body of the present invention, the water absorbent resin particles (P) and the fibrous material may be uniformly mixed, or one of them may be unevenly distributed.
By applying the water absorbent resin particles (P) to various absorbents, absorbent articles having excellent absorbent performance can be produced. The absorber is composed of water-absorbing resin particles (P) and fibrous material, and (1) water-absorbing resin particles (P ) in a form of scattering; (2) a form in which fibrous materials such as pulp and heat-fusible fibers are mixed with water-absorbing resin particles (P); A form in which the water absorbent resin particles (P) are sandwiched together with the fibrous material, if necessary, may be mentioned.

The amount of the water absorbent resin particles (P) of the present invention added to the absorbent body can be varied depending on the type and size of the absorbent body and the target absorption performance. It is preferably 10 to 95% by weight, more preferably 30 to 95% by weight, and particularly preferably 50 to 95% by weight, based on the total weight of the bulk material. Within this range, the absorption capacity of the obtained absorbent tends to be even better.

An adhesive binder may be added to bond the fibers together in order to enhance shape retention before and during use of the absorbent body. Such adhesive binders include, for example, heat-fusible synthetic fibers, hot-melt adhesives, adhesive emulsions, and the like.

Examples of heat-fusible synthetic fibers include all-melting binders such as polyethylene, polypropylene, and ethylene-propylene copolymers, and non-all-melting binders having a side-by-side or core-sheath structure of polypropylene and polyethylene. In the non-total melting binder described above, only the polyethylene portion is heat-sealed.

Hot melt adhesives include, for example, base polymers such as ethylene-vinyl acetate copolymers, styrene-isoprene-styrene block copolymers, styrene-butadiene-styrene block copolymers, and amorphous polypropylene with tackifiers, plasticizers, and antioxidants. and the like.

Examples of adhesive emulsions include polymers of at least one or more monomers selected from the group consisting of methyl methacrylate, styrene, acrylonitrile, 2-ethylhexyl acrylate, butyl acrylate, butadiene, ethylene, and vinyl acetate. be done. These adhesive binders may be used alone or in combination of two or more.

An absorbent article can be obtained using the water absorbent resin particles of the present invention. The absorbent article is preferably an absorbent article comprising an absorbent body, a liquid-permeable sheet and a breathable back sheet, more preferably an absorbent article as sanitary goods. Sanitary products include paper diapers (child diapers and adult paper diapers, etc.), napkins (sanitary napkins, etc.), paper towels, pads (pads for incontinent persons, surgical underpads, etc.), and pet sheets (pet urine absorption sheets). etc. Of these sanitary articles, paper diapers are more suitable. As for the configuration and manufacturing method of these absorbent articles, known ones can be applied.

For example, absorbent articles such as sanitary napkins and disposable paper diapers can be formed by sandwiching the absorbent body between a liquid-permeable sheet and a liquid-impermeable sheet.

Materials for the liquid-permeable sheet include, for example, polyolefins such as polyethylene and polypropylene, nonwoven fabrics made of polyester, polyamide, polyurethane, and the like, and porous synthetic resin films.

Materials for the liquid-impermeable sheet include, for example, synthetic resin films made of polyethylene, polypropylene, ethylene vinyl acetate, polyvinyl chloride, etc.; and a woven fabric. This liquid-impermeable sheet may have the property of being permeable to vapor.

The absorbent article of the present invention is not only used for sanitary products as described above, but also can be used as a pet urine absorbent, a urine gelling agent for portable toilets, a freshness preserving agent for fruits and vegetables, a drip absorbent for meat and seafood, a cooling agent, It is also useful for various applications such as disposable body warmers, gelling agents for batteries, water retention agents for plants and soil, dew condensation prevention agents, water stopping materials, packing materials, and artificial snow.

EXAMPLES The present invention will be further described with reference to examples below, but the present invention is not limited to these examples. Hereinafter, unless otherwise specified, % means % by weight, and part means part by weight.

<Production example of crosslinked polymer particles>
<Example 1>
Water-soluble vinyl monomer (a1) {acrylic acid} 155 parts (2.15 mol parts), cross-linking agent (b) {pentaerythritol triallyl ether} 0.6225 parts (0.0024 mol parts) and deionized water 340. 27 parts were kept at 3°C while stirring and mixing. After nitrogen was introduced into this mixture to make the dissolved oxygen content 1 ppm or less, 0.62 parts of a 1% aqueous hydrogen peroxide solution, 1.1625 parts of a 2% ascorbic acid aqueous solution and 2% 2,2'-azobis [ 2-Methyl-N-(2-hydroxyethyl)-propionamide] aqueous solution (2.325 parts) was added and mixed to initiate polymerization. After the temperature of the mixture reached 90° C., the mixture was polymerized at 90±2° C. for about 5 hours to obtain hydrous gel (1).
Next, 128.42 parts of a 48.5% sodium hydroxide aqueous solution was added and mixed while chopping 502.27 parts of this hydrous gel (1) with a mincing machine, followed by hydrophobic substance (g) {Mg stearate } 1.9 parts were added and mixed to obtain shredded gel (2). Further, the shredded gel (2) was dried with a ventilated band dryer {150° C., wind speed 2 m/sec} to obtain a dry product. The dried product was pulverized with a juicer mixer and then adjusted to a particle size of 150 to 710 μm using sieves with mesh openings of 150, 300, 500, 600 and 710 μm to obtain dried particles. 5 parts of a 2% water/methanol mixed solution of ethylene glycol diglycidyl ether (water/methanol weight ratio = 70/30) was added to 100 parts of the dried particles while being stirred at high speed and mixed. C. for 30 minutes for surface cross-linking to obtain a cross-linked polymer (A). While stirring 100 parts of this crosslinked polymer at high speed, organic iodine antifungal agent (B) {Pacific Beam Mold PBM-OK: manufactured by M.I.C. Co., Ltd., diiodomethyl-p-tolylsulfone} was added to 50% water. Two parts of the dispersion were added and mixed while spraying, and the mixture was allowed to stand at 80° C. for 30 minutes to obtain water absorbent resin particles (P-1). The water absorbent resin particles (P-1) had a weight average particle diameter of 400 μm and an apparent density of 0.58 g/ml. The weight average particle size and apparent density were measured by the following methods.

<Measurement of weight average particle size>
Standard sieves having openings of 1000 μm, 850 μm, 710 μm, 500 μm, 425 μm, 355 μm, 250 μm, 150 μm, 125 μm, 75 μm and 45 μm were stacked in order and assembled on a tray. About 50 g of water-absorbing resin particles were placed on the uppermost sieve and shaken for 5 minutes with a low-tap test sieve shaker. The weight of the particles remaining on each sieve and the tray is weighed, the total is 100% by weight, and the weight fraction of the particles on each sieve is obtained. Particle diameter) and weight fraction} on the vertical axis, then a line connecting each point was drawn to determine the particle diameter corresponding to a weight fraction of 50% by weight, which was taken as the weight average particle diameter.

<Measurement of apparent density>
It was measured in accordance with JIS K7365:1999 under an environment of 25°C.

<Example 2>
"Adjusted to a particle size of 150 to 710 μm using sieves with openings of 150, 300, 500, 600, and 710 μm" is adjusted to a particle size of 150 to 500 μm using sieves with openings of 150, 300, and 500 μm. Water-absorbent resin particles (P-2) were obtained in the same manner as in Example 1, except for changing to . The water absorbent resin particles (P-2) measured in the same manner as in Example 1 had a weight average particle diameter of 300 μm and an apparent density of 0.66 g/ml.

< Reference example 3>
Water absorbent resin particles (P-3) were obtained in the same manner as in Example 1, except that the hydrophobic substance (g) was not used. The water absorbent resin particles (P-3) measured in the same manner as in Example 1 had a weight average particle diameter of 400 μm and an apparent density of 0.64 g/ml.

< Reference example 4>
145.4 parts of acrylic acid was diluted with 9.4 parts of water and neutralized by adding 242.3 parts of 25% sodium hydroxide aqueous solution while cooling to 30-20°C. To this solution, 0.09 parts of ethylene glycol diglycidyl ether, 0.0146 parts of sodium hypophosphite monohydrate and 0.0727 parts of potassium persulfate are added and dissolved, and a biomixer (Nippon Seiki Co., Ltd.) is added and dissolved at 25 ° C. The mixture was stirred and dispersed for 2 minutes using an ABM-2 type manufactured by the company to obtain an aqueous monomer solution.

Next, 624 parts of cyclohexane are placed in a reaction vessel equipped with a stirrer, reflux condenser, thermometer and nitrogen gas inlet tube, and polyoxyethylene octylphenyl ether phosphate (Daiichi Kogyo Seiyaku Co., Ltd., product After adding and dissolving 1.56 parts of Plysurf A210G), nitrogen substitution was performed while stirring, and the temperature was raised to 70°C. Then, while maintaining the temperature at 70° C., the monomer aqueous solution was added dropwise at 6.6 parts/minute for 6 minutes and maintained at 75° C. for 15 minutes. Dripped. Then, after aging for 30 minutes at 75 ° C., the moisture content of the resin is about 20% by azeotroping water with cyclohexane (infrared moisture meter: FD-100 type, manufactured by Kett, measured at 180 ° C. for 20 minutes). was removed until After cooling to 30°C and stopping stirring, the water-containing absorbent resin particles settled down, so the absorbent resin particles and the cyclohexane layer were separated by decantation, filtered, dried under reduced pressure at 80°C, and dried. Particles were obtained. 0.06 parts of ethylene glycol diglycidyl ether as a surface cross-linking agent (d), and 0.42 of methanol were added to 100 parts of the dried particles while stirring at high speed (high-speed stirring turbulizer manufactured by Hosokawa Micron; number of revolutions: 2000 rpm). parts and 0.18 parts of ion-exchanged water were added, mixed uniformly, and then heated at 135° C. for 30 minutes to obtain a surface-crosslinked crosslinked polymer (A). While stirring 100 parts of this crosslinked polymer at high speed, organic iodine antifungal agent (B) {Pacific Beam Mold PBM-OK: manufactured by M.I.C. Co., Ltd., diiodomethyl-p-tolylsulfone} was added to 50% water. 0.6 part of the dispersion liquid was added while spraying and mixed, and allowed to stand at 80° C. for 30 minutes to obtain water absorbent resin particles (P-4). The water absorbent resin particles (P-4) measured in the same manner as in Production Example 1 had a weight average particle diameter of 320 μm and an apparent density of 0.50 g/ml.

<Comparative Example 1>
In Example 1, the 50% aqueous dispersion of the organic iodine antifungal agent (B) {Pacific Beam Mold PBM-OK: manufactured by M.I.C. Co., Ltd., diiodomethyl-p-tolylsulfone} was not added. Except for this, the same operation as in Example 1 was performed to obtain water absorbent resin particles (R-1) for comparison.

<Comparative Example 2>
In Example 1, "50% aqueous dispersion of organic iodine antifungal agent (B) {Pacific Beam Mold PBM-OK: manufactured by M.I.C. Co., Ltd., diiodomethyl-p-tolylsulfone}" was changed to " Water-absorbent resin particles (R-2) for comparison were obtained in the same manner as in Example 1, except that the antibacterial agent {benzalkonium chloride} was changed to a 50% aqueous solution.

Regarding the water absorbent resin particles (P-1) to (P-4) of Examples 1 and 2 and Reference Examples 3 and 4 and the water absorbent resins (R-1) to (R-2) of Comparative Examples 1 and 2 As a performance evaluation result, the time to absorb 40 times its own weight in physiological saline [physiological saline (40 times) absorption time], water retention amount and gel elastic modulus were measured by the following methods, weight average particle size and apparent density are listed in Table 1 together.

<Measurement of physiological saline (40 times) absorption time>
40 g of physiological saline (salt concentration: 0.9% by weight) was added to each 100 ml beaker containing 1.00 g of water absorbent resin particles (P). After that, the sample was allowed to stand without stirring, and the time until the physiological saline was completely absorbed was measured (at the end of water absorption, the beaker was tilted slightly to check for remaining liquid), and the physiological saline (40 times) was absorbed. time. The physiological saline solution used and the temperature of the measurement atmosphere were 25°C ± 2°C.

<Measurement of water retention>
Put 1.00 g of water-absorbing resin particles (P) in a tea bag (20 cm long, 10 cm wide) made of nylon mesh with an opening of 63 μm (JIS Z8801-1: 2006), and add physiological saline (salt concentration 0.9 weight %) was immersed in 1,000 ml for 1 hour without stirring. Thereafter, the tea bag was removed from the physiological saline solution, hung for 15 minutes to drain water, placed in a centrifuge together with the tea bag, and dehydrated by centrifugation at 150 G for 90 seconds to remove excess physiological saline solution. The weight (h1) including the tea bag after dehydration was measured. Further, the weight of the tea bag was measured in the same manner except that the crosslinked polymer particles were not added (h2), and the water retention amount was obtained from the following equation.
Water retention amount (g/g) = (h1) - (h2)
The physiological saline used and the temperature of the measurement atmosphere were set to 25°C ± 2°C.

<Measurement of gel elastic modulus>
Artificial urine [200 parts by weight of urea, 80 parts by weight of sodium chloride, 8 parts by weight of magnesium sulfate (heptahydrate), 3 parts by weight of calcium chloride (dihydrate), 2 parts by weight of ferric sulfate (heptahydrate), ions Exchanged water 9704 parts by weight] 60.0 g is weighed into a 100 ml beaker (inner diameter 5 cm), and in the same manner as described in JIS K7224-1996, 2.0 g of the water absorbent resin particles (P) are weighed accurately. It was put into a beaker to prepare a 30-fold swollen gel. Then, the beaker containing the 30-fold swollen gel was wrapped and allowed to stand in an atmosphere of 40 ± 2 ° C. for 3 hours and further in an atmosphere of 25 ± 2 ° C. for 0.5 hours. The rate was measured using a card meter Max ME-500 manufactured by Itec Techno Engineering Co., Ltd. under the following conditions.
(Conditions of card meter)
・Pressure-sensitive shaft: 8mm
・Spring: for 100g ・Load: 100g
・Rise rate: 1 inch/7 seconds ・Test properties: rupture ・Measurement time: 6 seconds ・Measurement ambient temperature: 25±2°C

<Example 5>
50 parts of the hydrophilic fiber (C) {fluff pulp} and 50 parts of the water-absorbing resin particles (P-1) are mixed in an airflow mixing device {pad former} to obtain a mixture, and then the basis weight of the mixture is It was evenly laminated on an acrylic plate (thickness: 4 mm) so as to have a weight of 250 g/m ² and pressed at a pressure of 5 kg/cm ² for 30 seconds to obtain Absorbent (1). This absorber (1) was cut into rectangles of 10 cm x 40 cm, and water-permeable sheets of the same size as the absorber {basis weight 15.5 g/m ² , manufactured by Advantech, filter paper No. 2} were placed above and below each piece. Then, an absorbent body (2) was obtained. Furthermore, as a back sheet, a polyethylene sheet (polyethylene film UB-1 manufactured by Tamapoly Co., Ltd.) is placed on the back side, and a non-woven fabric {non-woven fabric basis weight: 25 g/m ² , Toyobo Co., Ltd. 2.2T 44-SMK} is placed on the front side to improve absorbency. Article (1) was prepared. The weight ratio of the water-absorbing particles and the hydrophilic fibers (the weight of the water-absorbing resin particles/the weight of the hydrophilic fibers) was 50/50.

<Example 6>
An absorbent article (2) was prepared in the same manner as in Example 5, except that the water absorbent resin particles (P-1) were changed to the water absorbent resin particles (P-2).

< Reference example 7>
An absorbent article (3) was prepared in the same manner as in Example 1, except that the water absorbent resin particles (P-1) were changed to the water absorbent resin particles (P-3).

< Reference example 8>
An absorbent article (3) was prepared in the same manner as in Example 1, except that the water absorbent resin particles (P-1) were changed to the water absorbent resin particles (P-4).

<Comparative Example 3>
An absorbent article (H1) was prepared in the same manner as in Example 5, except that the water absorbent resin particles (P-1) were changed to the water absorbent resin particles (R-1).

<Comparative Example 4>
An absorbent article (H2) was prepared in the same manner as in Example 5, except that the water absorbent resin particles (P-1) were replaced with the water absorbent resin particles (R-2).

The absorbent articles (1 to 4) obtained in Examples 5 and 6 and Reference Examples 7 and 8 and the comparative absorbent articles (H1 and H2) obtained in Comparative Examples 3 and 4 were subjected to an odor test by the following method. and antifungal properties were evaluated, and the results are shown in Table 2.

Human urine was prepared for the odor test and antifungal test. The human urine was collected from 8 adults within 2 hours after excretion and used as a human urine mixture.
<Odor test>
A metal ring (inner diameter: 70 mm, length: 50 mm) was set in the center of each of the absorbent articles obtained in Examples 5 and 6, Reference Examples 7 and 8, and Comparative Examples 3 and 4, and 160 ml of a human urine mixture was injected, As soon as urine had been absorbed {until no urine gloss was observed}, the metal ring was removed and left for 5 minutes. The measurement atmosphere and the storage atmosphere were 25±5° C. and 55±10% RH. Subsequently, the absorbent article was sealed and stored in a cool and dark place at room temperature (25° C.), and after one day had passed, its odor was confirmed.

The odor was confirmed by randomly selected monitors (10 adults). The odor of the absorbent article was evaluated according to the following criteria, with the odor of the human urine mixture after one day being regarded as "Level 5".
Level 5: Strong odor (smell of human urine mixture after 1 day)
Level 4 Strong odor Level 3 Easily recognizable odor Level 2 Weak odor level 1 that allows you to recognize what it smells Level 0 barely perceivable odor Level 0 Odorless

Evaluation was made by averaging (rounding off) the scores of all the above monitors.

<Antifungal test>
Storage in a cool dark place at room temperature (25° C.) and a relative humidity of 90% or more was continued, and after four days had passed, the absorbent article was observed to confirm the presence or absence of mold.

As can be seen from Table 2, the absorbent articles of the present invention were superior to the absorbent article for comparison in malodor suppression and mildew resistance. Therefore, when the absorbent article of the present invention is used, it can be easily predicted that there will be no unpleasant odor after use and no mold generation at the time of disposal.

The absorbent articles of the present invention include paper diapers for children, paper diapers for adults, napkins, pet sheets, panty liners, incontinence pads, perspiration sheets, blood absorbent articles for medical use, wound protection materials, wound healing agents, waste fluid treatment agents for surgical operations, and the like. useful for

Claims (4)

A water-soluble vinyl monomer (a1) and/or a vinyl monomer (a2) that becomes a water-soluble vinyl monomer (a1) by hydrolysis, and a crosslinked polymer (A) having a crosslinking agent (b) as essential structural units, and an organic iodine-based inhibitor Water absorbent resin particles containing a fungicide (B), wherein the organic iodine fungicide (B) is diiodomethyl-p-tolylsulfone, and the crosslinked polymer (A) is sorbitol stearate. , At least one hydrocarbon group-containing hydrophobic substance (g1) selected from the group consisting of sucrose stearate, stearic acid, Mg stearate, Ca stearate, Zn stearate and Al stearate and containing only an organic iodine-based antifungal agent (B) as an antibacterial agent (antifungal agent) .
2. The water absorbent resin particles according to claim 1 , wherein the content of the organic iodine antifungal agent (B) is 0.001 to 10% by weight based on the weight of the water absorbent resin particles. An absorbent body comprising the water absorbent resin particles according to claim 1 or 2 and a fibrous material. An absorbent article using the absorbent body according to claim 3 .