JP4966763B2 - Absorbent articles - Google Patents

Description

  The present invention relates to an absorbent article having a deodorizing ability.

Conventionally, absorbent articles such as disposable diapers have been proposed to have a deodorizing effect by using a deodorant such as zeolite or activated carbon to prevent the smell of excrement from coming out of the absorbent article. (For example, see the following Patent Document 1 relating to the prior application of the present applicant).
The absorptive article given in patent documents 1 has the above-mentioned deodorizing effect by using the deodorant which has the pore which has a specific opening area in a specific ratio.

JP 2001-70339 A

  According to the absorbent article described in Patent Document 1, a considerable deodorizing effect is achieved. However, in the absorbent article, further improvement in the deodorizing effect is desired.

  Accordingly, an object of the present invention is to provide an absorbent article having a further excellent deodorizing effect.

The present invention relates to deodorized particles obtained by copolymerizing a monomer component containing a crosslinkable vinyl monomer and a vinyl monomer having a heteroaromatic ring and having a BET specific surface area of 10 m ² / g or more and containing metal ions. The said objective is achieved by providing the provided absorbent article.

  The absorbent article of the present invention has an excellent deodorizing effect by including deodorant particles that exhibit high deodorizing ability regardless of the properties of malodorous gas. The deodorizing particles have metal ions supported on the heteroaromatic rings in the polymer particles, so that the deodorizing ability is dramatically improved, and even the human urine, which is a complex odor of many malodorous components, has a very high deodorizing capacity. Shows odor ability. Therefore, the absorbent article of the present invention can effectively deodorize malodors caused by excrement.

  Hereinafter, the absorptive article of the present invention is explained based on the preferred embodiment. The absorbent article of the present invention is mainly used for absorbing and holding excretory body fluids such as urine and menstrual blood. The absorbent article of the present invention includes, for example, disposable diapers, incontinence pads, sanitary napkins, but is not limited thereto, and widely includes articles used to absorb liquid discharged from the human body. To do.

The absorbent article of the present invention typically includes a top sheet, a back sheet, and a liquid-retaining absorbent body disposed between both sheets. As the top sheet and the back sheet, materials usually used in the technical field can be used without particular limitation. For example, as the surface sheet, liquid permeable sheets such as various nonwoven fabrics and perforated films subjected to a hydrophilic treatment can be used. As the back sheet, a liquid-impermeable or water-repellent sheet such as a thermoplastic resin film or a laminate of the film and a nonwoven fabric can be used. The back sheet may have water vapor permeability.
The absorbent article may further include various members according to the specific application. Such members are known to those skilled in the art. For example, when the absorbent article is applied to a disposable diaper or a sanitary napkin, a pair of three-dimensional guards can be disposed on both the left and right sides of the absorbent article.

  The absorbent article of the present invention includes deodorant particles. The deodorant particles can be obtained by copolymerizing a monomer component containing a crosslinkable vinyl monomer and a vinyl monomer having a heteroaromatic ring.

  The crosslinkable vinyl monomer is a monomer having two or more vinyl groups. Examples of the crosslinkable vinyl monomer include divinylbenzene, trivinylbenzene, ethylene glycol di (meth) acrylate and the like, and divinylbenzene is preferable. As the proportion of the crosslinkable vinyl monomer in the monomer component increases, deodorized particles having a large BET specific surface area can be obtained. Therefore, the proportion of the crosslinkable vinyl monomer in all the monomer components is preferably 5% by mass or more, more preferably 20% by mass or more, and further preferably 50% by mass or more. 98 mass% or less is preferable and the upper limit of this ratio has more preferable 90 mass% or less.

  The vinyl monomer having a heteroaromatic ring is not particularly limited as long as it is a compound containing a vinyl group and a heteroaromatic ring. The heteroaromatic ring is a ring in a cyclic organic compound and includes an oxygen atom, a sulfur atom, a nitrogen atom and the like as a constituent element in addition to a carbon atom. Examples of those containing a nitrogen atom include those having one nitrogen atom such as pyridine, pyrrole and quinoline in the ring, and those having two nitrogen atoms such as imidazole, pyrimidine, pyrazine and pyrazole in the ring. Further, those having a sulfur atom such as thiophene and thiazole in the ring and those having oxygen such as furan in the ring are exemplified. It is considered that the lone pair of electrons of the hetero atom enhances the adsorption of malodorous substances and participates in the chemical bonding of metal ions. Among these, pyridine, imidazole, and pyrimidine are preferable. Examples of the vinyl monomer having a heteroaromatic ring include 2-vinylpyridine, 4-vinylpyridine, 1-vinylimidazole, 2-vinylpyrimidine, and the like, with 2-vinylpyridine and 4-vinylpyridine being preferred.

  In order to sufficiently adsorb malodorous components and to carry a sufficient amount of metal salt, the ratio of vinyl monomers having a heteroaromatic ring in all monomer components is preferably sufficiently large, preferably 1% by mass or more. 2 mass% or more is more preferable, and 4 mass% or more is further more preferable. Further, when the absorption effect is enhanced by increasing the BET specific surface area of the deodorant particles, the ratio of the vinyl monomer having a heteroaromatic ring in all monomer components is preferably 50% by mass or less, and 30% by mass. % Or less is more preferable.

  In the deodorant particle in this invention, the monomer component can use other monomers copolymerizable with these besides the crosslinkable vinyl monomer and the vinyl monomer having a heteroaromatic ring. Examples of the other monomers include aromatic vinyl monomers, unsaturated acid esters, and unsaturated acids. Examples of aromatic vinyl monomers include styrene, α-methylstyrene, vinyl toluene, ethyl vinyl benzene, vinyl benzyl chloride, and the like, and unsaturated acid esters include methyl (meth) acrylate and ethyl (meth) acrylate. , (Propyl) (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, glycidyl (meth) acrylate, etc. Examples of the saturated acid include (meth) acrylic acid. Moreover, acrylonitrile, methacrylonitrile, etc. can also be used. Of these, aromatic vinyl monomers are preferred, and styrene is particularly preferred.

  In the present specification, (meth) acrylate means acrylate or methacrylate, and (meth) acrylic acid means acrylic acid or methacrylic acid.

The BET specific surface area of the deodorant particles in the present invention can be arbitrarily set by the ratio of the crosslinkable vinyl monomer and the selection of the organic solvent used for the polymerization, but the larger the value, the higher the deodorizing effect. From the viewpoint of having a high physical consumption Nioino is at 10 m ² / g or more, preferably at least 50 m ² / g, more preferably at least 200 meters ² / g, still more preferably at least 300m ² / g. The upper limit of the BET specific surface area is not particularly limited, but is preferably 800 m ² / g or less. In addition, a BET specific surface area is the value calculated | required by the BET 1 point method shown in the following Example.
The particle size of the deodorant particles is not particularly defined, and an appropriate one can be selected according to the absorbent article in which it is used. The deodorant particles may be granular with a particle size of about 0.1 to 5 mm, or may be powder with a particle size of about 0.1 to 100 μm. When deodorized particles having a particle size of 0.1 to 10 μm are used, blending with other materials is easy. When used in the wet papermaking method, the particle size is preferably 1-1000 μm, particularly preferably 10-200 μm.

  The deodorant particles in the present invention are preferably produced by an oil-in-water suspension polymerization method or a precipitation polymerization method.

  In the oil-in-water suspension polymerization method, a monomer component containing a crosslinkable vinyl monomer and a vinyl monomer having a heteroaromatic ring, an organic solvent, a surfactant, water and, if necessary, a polymerization initiator are mixed to obtain an oil-in-water solution. A mold emulsion is prepared. When the emulsion is heated and polymerized, polymer particles are produced by phase separation from the organic solvent. Thereafter, filtration is performed to remove water and the surfactant, and further, drying is performed to remove the organic solvent, whereby porous deodorant particles can be obtained.

  In the precipitation polymerization method, a monomer component containing a crosslinkable vinyl monomer and a vinyl monomer having a heteroaromatic ring, an organic solvent, and a polymerization initiator as necessary are mixed, and the mixture is heated to polymerize the polymer particles. Is generated. Thereafter, the organic solvent is removed by drying to obtain porous deodorant particles.

  Examples of the organic solvent used in the oil-in-water suspension polymerization method include at least one selected from aromatic compounds, aliphatic hydrocarbons, and alcohols. Specific examples include benzene, toluene, xylene, ethylbenzene, o-dichlorobenzene, hexane, heptane, octane, isooctane, decane, cyclohexane, n-butanol, t-butanol, 1-hexanol, and the like. Octane and toluene are preferred. From the viewpoint of not reducing the specific surface area of the particles, the proportion of the organic solvent used is preferably 5% by mass or more, more preferably 25% by mass or more, based on the total monomer mass used. Moreover, from a viewpoint of obtaining a favorable polymerization rate, 300 mass% or less is preferable with respect to the total monomer mass to be used, and 150 mass% or less is more preferable.

  The organic solvent used in the precipitation polymerization method is water-soluble such as methanol, ethanol, 1-propanol, isopropanol, 1-butanol, methyl isobutyl carbinol, in addition to the organic solvent used in the oil-in-water suspension polymerization method. High alcohols can be used alone or mixed with other organic solvents so that the absolute value of the solubility parameter difference with the monomer component is 0 to 2.0. The proportion of the organic solvent used is preferably 100% by mass or more based on the total monomer mass used, from the viewpoint of preventing the specific surface area of the particles from being reduced and preventing the gelation of the solution and stirring uniformly. The above is more preferable. Moreover, from a viewpoint of obtaining a favorable polymerization rate, 1000 mass% or less is preferable with respect to the total monomer mass to be used, and 500 mass% or less is more preferable.

In order to obtain deodorized particles having a sufficient BET specific surface area by the oil-in-water suspension polymerization method and the precipitation polymerization method, it is desirable that the difference between the solubility parameter of the monomer component and the organic solvent is small. The solubility parameter is calculated by the method of Fedors [RFFedors, Polym. Eng. Sci., 14, 147 (1974)], and the unit is represented by (cal / cm ³ ) ^1/2 . The solubility parameter is one of indices indicating the affinity between the monomer component and the organic solvent, and the closer the value, the higher the compatibility between the two.

The solubility parameter δ of the compound is obtained by the following equation.
δ = (ΔE / V) ^1/2 (cal / cm ³ ) ^1/2
(In the formula, ΔE represents evaporation energy and V represents molar volume.)

Further, the solubility parameter δ _mix of a mixture composed of two or more compounds is represented by the following equation.
δ _mix = Σδ _i φ _i (cal / cm ³ ) ^1/2
(In the formula, δ _i represents the solubility parameter of each component constituting the mixture, and φ represents the volume fraction of that component.)

  If the difference in solubility parameter between the monomer component and the organic solvent is too large, the BET specific surface area of the resulting deodorant particles will be significantly reduced. Therefore, in order to obtain deodorant particles having a large BET specific surface area, the absolute value of the difference in solubility parameter between the monomer component and the organic solvent is preferably set to 0 to 2.0. The absolute value of the difference in solubility parameter is more preferably 1.6 or less. When producing deodorant particles by the oil-in-water suspension polymerization method, the lower limit of the absolute value of the difference in solubility parameter is not particularly limited. When producing deodorant particles by precipitation polymerization, the absolute value of the difference in solubility parameter is preferably 0.5 or more, more preferably 1.0 or more.

  The surfactant used in the oil-in-water suspension polymerization method should be capable of forming a stable oil-in-water emulsion when a monomer component containing a crosslinkable vinyl monomer and a vinyl monomer having a heteroaromatic ring is mixed with water. There is no particular limitation. Examples of the surfactant include an anionic surfactant such as dodecyl sulfate, dodecyl benzene sulfonate, N-stearyl taurate, sulfate salt of polyoxyethylene nonyl phenyl ether, polyoxyethylene nonyl phenyl ether, Nonionic surfactants such as polyoxyethylene dodecyl phenyl ether, sorbitan monostearate, polyoxyethylene sorbitan monostearate, polyvinyl alcohol and the like can be mentioned, and sodium N-stearyl taurate or polyvinyl alcohol is preferred. The amount of the surfactant to be used is not particularly limited as long as the oil-in-water emulsified state is stable, but the concentration is preferably 0.01 to 3% by mass with respect to water, and 0.1 to 1% by mass. It is more preferable that

  The polymerization initiator is one that initiates the addition polymerization of a monomer by radical decomposition with heat. For example, oil-soluble peroxodisulfates, peroxides, azobis compounds, and the like are common.

  The deodorant particles in the present invention further contain a metal ion. The deodorant particles can carry metal ions on their pore surfaces by coordination bonds with the heteroaromatic ring present in the polymer surface layer. In this case, malodorous gases such as ammonia, amines, mercaptans, and fatty acids are adsorbed by coordination bonds with metal ions. That is, the deodorizing particles carrying metal ions are particles having a remarkably high deodorizing ability that has both a physical deodorizing ability due to a large BET specific surface area and a chemical deodorizing ability due to the carried metal ions.

  Examples of metal ions include silver ions, zinc ions, aluminum ions, cobalt ions, zirconium ions, cerium ions, iron ions, copper ions, nickel ions, platinum ions and the like, and silver ions and zinc ions are preferable.

The deodorized particles carrying metal ions are brought into contact with the slurry after the completion of the polymerization, or the dried particles from which the organic solvent has been removed, and the solvent in which the metal salt is dissolved, and if necessary, the temperature is 30 to 80 ° C. It can be produced by mixing while heating.
The amount of metal ions supported is preferably 0.01% by mass or more, and more preferably 0.1% by mass or more with respect to the polymer particles. The upper limit of the amount of metal ions supported is not particularly limited, but is preferably 10% by mass or less, and more preferably 5% by mass or less.

  The metal salt used for supporting metal ions on the deodorant particles is not particularly limited as long as it dissolves in water or an organic solvent. Examples of the metal salt include silver nitrate, aluminum nitrate, cobalt nitrate, zirconium nitrate, cerium nitrate, iron (II) nitrate, iron (III) nitrate, copper nitrate, nickel nitrate, silver acetate, cerium chloride, iron chloride (II). ), Iron (III) chloride, zinc chloride, copper chloride, silver perchlorate, aluminum perchlorate, platinum perchlorate, zinc perchlorate, zirconium perchlorate, silver sulfate, aluminum sulfate, copper sulfate, zinc sulfate These may be used, and these may be used alone or in combination of two or more. Particularly preferred are silver nitrate, silver acetate, and zinc chloride.

  The solvent for dissolving the metal salt is not particularly limited as long as the metal salt to be used dissolves and the deodorant particles are uniformly dispersed. Examples of the solvent include alcohols such as water, diethyl ether, acetone, methanol, ethanol, 1-propanol, isopropanol, and glycerin. These may be used alone or in combination of two or more. Good.

  The configuration in which the absorbent article includes deodorant particles is not particularly limited, but in a typical form of the absorbent article including an absorbent body disposed between a top sheet, a back sheet, and both sheets, for example, (a ) A configuration in which deodorant particles are supported on the constituent fibers of the absorber in the form of particles, and (b) a particle-adhered sheet formed by attaching the deodorant particles to the fiber material is between the surface sheet and the absorber. The structure arrange | positioned between an absorber or between an absorber and a back surface sheet is mentioned.

The configuration in which the deodorant particles in (a) are supported on the constituent fibers of the absorber in the form of particles is, for example, by spreading the deodorant particles on an assembly of constituent fibers such as a short fiber or a long fiber web, They are obtained by covering them with a backing paper. A superabsorbent polymer can be further supported on the constituent fibers. In that case, it is convenient to mix the deodorant particles and the superabsorbent polymer in advance before spraying, and spray the mixture onto the aggregate of the constituent fibers. Further, the deodorant particles may be attached to the superabsorbent polymer in advance, and the attached matter may be dispersed on the assembly of the constituent fibers.
The amount of the deodorant particles to be blended in the absorbent article is not particularly limited. For example, in the case of an absorbent article that absorbs 100 ml of urine, 40 mg or more per article is preferable.

  The fiber material in the particle-adhered sheet of (b) is preferably capable of wet papermaking. Examples of preferable fiber materials include cellulosic fibers such as pulp and rayon. In addition to these fibers, a small amount of heat-fusible fibers made of a thermoplastic resin can be used in combination.

  The particle-attached sheet of (b) may be in the form of a single layer sheet containing deodorant particles, or may be in the form of a laminated sheet in which a plurality of sheets containing deodorant particles are laminated. When the particle-adhered sheet is in the form of a single-layer sheet, the sheet is produced, for example, by a wet papermaking method using a slurry containing a fiber material and deodorant particles as a raw material.

  When the particle-adhered sheet is in the form of a laminated sheet, an example of the sheet is a multilayer sheet having the form shown in FIG. The particle-adhered sheet 1 shown in FIG. 1 is wider than these pulp sheets 2 and 3 between two rectangular sheets of the same size, that is, between the first pulp sheet 2 and the second pulp sheet 3. It is a laminated sheet formed by interposing a rectangular inner layer sheet 4 having a short direction length. The inner layer sheet 4 is the same as the sheet of fiber material to which the deodorant particles are attached, that is, the single layer sheet described above. The inner layer sheet 4 is sandwiched between the two pulp sheets 2 and 3 at the center in the width direction. The inner layer sheet 4 and the pulp sheets 2 and 3 are laminated by papermaking.

  In the side portions 1a and 1b of the particle adhesion sheet 1, the inner layer sheet 4 is not interposed over the entire length direction, and the two pulp sheets 2 and 3 are laminated on the side portions 1a and 1b. It has a two-layer structure. By joining the pulp sheets 2 and 3 in the side portions 1a and 1b, respectively, both end portions of the particle adhesion sheet 1 are sealed, and deodorant particles are prevented from falling off from the side end portions. The width of the side portions 1a and 1b is preferably 0.1 to 20 cm, and more preferably 1 to 6 cm from the viewpoint of sufficiently preventing the deodorant particles from falling off and fully expressing the function of the deodorant particles.

  As described above, the fiber material sheet to which the deodorant particles are attached (that is, the single-layer sheet and the inner layer sheet 4 described above) is manufactured by a wet papermaking method using a slurry containing the fiber material and the deodorant particles as a raw material. From the viewpoint of increasing the amount of deodorant particles attached to the fiber material, a flocculant may be added to the slurry. As the aggregating agent, for example, polyacrylamide is preferably used. The amount of the deodorant particles in the slurry is preferably 0.1 to 50 parts by mass, particularly 0.5 to 30 parts by mass with respect to 100 parts by mass of the fiber material. The concentration of the fiber material in the slurry is preferably 0.5 to 5.0% by mass, particularly 1.0 to 3.0% by mass.

The content of the deodorizing particles in the sheet obtained by the wet papermaking method (that is, the single layer sheet and the inner layer sheet 4 described above) is preferably 0.1% by mass or more, more preferably 0.5% by mass or more. 2 mass% or more is still more preferable. Although there is no restriction | limiting in particular in the upper limit of content, From an economical viewpoint, it is preferable that it is 30 mass% or less. Although it depends on the specific application, the basis weight of the sheet is preferably 10 to 100 g / m ² , more preferably 10 to 50 g / m ² .

The particle-adhered sheet can be used by chopping it into small pieces. For example, a particle adhesion sheet chopped into broken pieces can be used by being supported on the constituent fibers of the absorber.
Also, a high-concentration slurry of fiber material with deodorant particles attached is extruded into a strand form from an extruder, cut into a predetermined size into a granular shape, and used by supporting it on the constituent fibers of the absorber Can do.

The particle-attached sheet is disposed, for example, between the liquid-permeable top sheet and the liquid-retaining absorbent, the absorbent body, or the absorbent and the liquid-impermeable or water-repellent back sheet. be able to. FIG. 2 shows a state in which the absorber is covered with the multilayer particle adhesion sheet shown in FIG. The particle adhesion sheet 1 may be a single layer. The absorbent body 10 is composed of pulp fibers and highly absorbent polymer particles. The absorber 10 is covered with the particle adhesion sheet 1 so that the one side part 1a and the other side part 1b of the particle adhesion sheet 1 are overlapped. Under this state, the absorbent body 10 is sandwiched between a top sheet (not shown) and a back sheet (not shown).
Therefore, in this embodiment, the particle adhesion sheet 1 is disposed between the top sheet and the absorbent body 10 and between the back sheet and the absorbent body 10 in the absorbent article.

  Moreover, the particle adhesion sheet 1 can be arrange | positioned in an absorber. Specifically, as shown in FIG. 4, in the absorbent body 10 including the assembly 13 of the constituent fibers and the mount 14 that wraps the constituent fibers, the particle adhesion sheet 1 encloses the assembly 13 of the constituent fibers and the mount 14. It is arrange | positioned with the form enclosed by. The absorber 10 is sandwiched between the top sheet 11 and the back sheet 12.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such examples. In the following examples, “%” means “% by mass” unless otherwise specified.

[Example 1-1]
Deodorized particles were obtained by the oil-in-water suspension polymerization method shown below. In 112.5 g of octane and 37.5 g of toluene, 100 g of a monomer (styrene / divinylbenzene / 2-vinylpyridine = 12.5% / 75% / 12.5%) and 3 g of lauroyl peroxide were dissolved. 500 g of water in which 1.5 g of sodium stearyl taurate was dissolved was added to the polymerization tank. At this time, the solubility parameters of the monomer mixture and the organic solvent were 9.32 (cal / cm ³ ) ^1/2 and 7.92 (cal / cm ³ ) ^1/2 , respectively, and the difference was 1.40 (cal / cm cm ³ ) ^1/2 . Thereafter, the mixed solution thus prepared is emulsified by stirring at 10,000 rpm for 5 minutes using a homogenizer, and this is polymerized by heating at 85 ° C. for 4 hours and further at 95 ° C. for 3 hours under a stirring condition of 200 rpm. Then, water and the organic solvent were removed by filtration and dried to obtain deodorized particles. The volume average diameter of the deodorant particles was 7.3 μm. 100 g of the obtained deodorant particles were added to 1000 g of ethanol in which 0.5 g of silver nitrate was dissolved, and the mixture was stirred at room temperature for 6 hours for carrying treatment. This was filtered and then washed with water to obtain silver nitrate-supported deodorant particles. The obtained deodorant particles had a BET specific surface area of 416 m ² / g and a silver ion content of 0.27%. The volume average diameter, BET specific surface area and silver ion content were measured by the following methods.

Volume average diameter: Deodorized particles were crushed with a coffee mill and measured with a Coulter Counter (manufactured by Coulter Corporation) in a state of being dispersed in hexane.
BET specific surface area: Determined by the BET 1-point method using Flowsorb 2300 (manufactured by Shimadzu Corporation). As the adsorption gas, a gas of 30% by volume of nitrogen and 70% by volume of helium was used. As pretreatment of the sample, the adsorbed gas was circulated at 120 ° C. for 10 minutes. Thereafter, the cell containing the sample was cooled with liquid nitrogen, heated to room temperature after completion of adsorption, and the surface area of the sample was determined from the amount of desorbed nitrogen. The specific surface area was determined by dividing by the mass of the sample.
Silver ion content: Measured using monochrome excited EDX fluorescent X-rays.

A model absorbent article having a structure shown in FIG. 3 was produced using the obtained deodorant particles. Specifically, 2 g of the pulp fiber aggregate 13 was used as the constituent fiber of the absorbent body 10, and 20 mg of deodorant particles and 2 g of the superabsorbent polymer were dispersed and supported on the aggregate 13. This was wrapped with mount 14 (basis weight 15 g / m ² ) to form the absorbent body 10.
And the absorber 10 was wrapped so that it might be pinched | interposed with the surface sheet 11 (air through nonwoven fabric: 25 g / m < ² >) and the back surface sheet 12 (moisture-permeable film: 40 g / m < ² >). In this way, a model absorbent article was produced.

[Example 1-2]
The content of deodorant particles in the absorbent body 10 was 40 mg. Other than that is the same as Example 1-1.
[Example 1-3]
The content of deodorant particles in the absorbent body 10 was 78 mg. Other than that is the same as Example 1-1.

[Example 2-1]
Deodorized particles were obtained by the precipitation polymerization method shown below.
To 225 g of octane and 75 g of toluene, 100 g of a monomer (styrene / divinylbenzene / 2-vinylpyridine = 12.5% / 75% / 12.5%) and 3 g of lauroyl peroxide were dissolved and added to the polymerization tank. At this time, the solubility parameters of the monomer mixture and the organic solvent were 9.32 (cal / cm ³ ) ^1/2 and 7.92 (cal / cm ³ ) ^1/2 , respectively, and the difference was 1.40 (cal / cm cm ³ ) ^1/2 . Then, after superposing | polymerizing by heating the prepared liquid mixture at 85 degreeC for 4 hours and also at 95 degreeC for 3 hours, it dried and obtained deodorant particle | grains. 100 g of the obtained deodorant particles were added to 1000 g of ethanol in which 0.5 g of silver nitrate was dissolved, and the mixture was stirred at room temperature for 6 hours for carrying treatment. This was filtered and then washed with water to obtain silver nitrate-supported deodorant particles. The obtained deodorant particles had a BET specific surface area of 486 m ² / g and a silver ion content of 0.28%.
A model absorbent article was produced in the same manner as in Example 1-1 except that the method for producing deodorant particles was different.

[Example 2-2]
The amount of deodorant particles in the absorber was 40 mg. Other than that is the same as Example 2-1.
[Example 2-3]
The amount of deodorant particles in the absorber was 78 mg. Other than that is the same as Example 2-1.

[Comparative Examples 1-1 to 1-3]
In Comparative Examples 1-1 to 1-3, as compared with Examples 1-1 to 1-3, respectively, the same amount of zinc chloride activated activated carbon is used instead of the deodorant particles. Otherwise, a model absorbent article was produced in the same manner as in Example 1-1.

[Comparative Example 2]
The particles were obtained by the suspension polymerization method shown below. Otherwise, a model absorbent article was produced in the same manner as in Example 1-3.
100 g of monomer (styrene / divinylbenzene = 25% / 75%) and 3 g of lauroyl peroxide are dissolved in 112.5 g of octane and 37.5 g of toluene, and 500 g of 1.5 g of sodium N-stearyl taurate dissolved therein. Was added to the polymerization tank. At this time, the solubility parameters of the monomer mixture and the organic solvent were 9.27 (cal / cm ³ ) ^1/2 and 7.92 (cal / cm ³ ) ^1/2 , respectively, and the difference was 1.35. . Thereafter, the mixed solution thus prepared is emulsified by stirring at 10,000 rpm for 5 minutes using a homogenizer, and this is polymerized by heating at 85 ° C. for 4 hours and further at 95 ° C. for 3 hours under a stirring condition of 200 rpm. Then, water and the organic solvent were removed by filtration and dried to obtain particles. The obtained particles had a BET specific surface area of 427 m ² / g.

[Comparative Example 3]
In Comparative Example 3, GP-1B (made by Toyo Styrene Co., Ltd .: BET specific surface area 0.17 m ² / g), which is non-porous polystyrene particles, is used instead of the deodorant particles as compared with Example 1-3. Are used in the same amount. Otherwise, a model absorbent article was produced in the same manner as in Example 1-3.

[Comparative Example 4]
Compared with Example 1-1, the said deodorizing particle was abbreviate | omitted. Otherwise, a model absorbent article was produced in the same manner as in Example 1-1.

[Evaluation method of deodorizing ability]
500 ml of human urine prepared by mixing 100 ml of urine of 5 adult males is prepared. 30 g of human urine is absorbed in the model absorbent articles obtained in the above Examples and Comparative Examples, and quickly put into a closed container (Tight Box No. 3: manufactured by Butterfly Plastic Industry Co., Ltd.) having a volume of 1.2 liters. And airtight. After 60 minutes, the container was opened, and the smell in the container was evaluated by five monitors. The evaluation criteria are as follows. The average of five people's evaluation was computed and the value was made into the sensory value of odor intensity. The sensory value means that the smaller the value, the weaker the odor. The same human urine was used in the examples and comparative examples. The evaluation results are shown in Table 1 below.

〔Evaluation criteria〕
3.0; Strongly feel the odor peculiar to urine 2.0; Feel the smell peculiar to urine 1.0; Feel the odor but not the smell of urine odor 0.0; Do not smell

  As is clear from the results shown in Table 1, in the examples of the present invention (Examples 1-1 to 1-3 and Examples 2-1 to 2-3), the deodorized particles are provided, so that the activated carbon is used. It turns out that the deodorizing ability equivalent to or more than the conventional deodorant (Comparative Examples 1-1 to 1-3) is obtained. The deodorant made of activated carbon exhibits a black color, whereas the deodorant particles in the present invention are white and are particularly suitable as a deodorant for absorbent articles. Moreover, the particle | grains (comparative example 2) which do not contain the vinyl monomer which has a hetero aromatic ring, and the particle | grains (comparative example 3) with a small BET specific surface area have low deodorizing performance.

  Moreover, the difference of the deodorizing ability by the difference in the structure of an absorbent article was evaluated using the following Examples 3-1 to 3-3 and the said Examples 1-1 to 1-3.

[Example 3-1]
Using the same deodorant particles as the deodorant particles in Example 1-1, a particle-attached sheet was prepared by the wet papermaking method shown below.
Deodorized particles, softwood kraft pulp, wet paper strength agent (WS4024: manufactured by Seiko PMC) and polyacrylamide polymer flocculant (Acofloc A95: manufactured by Mitsui Aqua Polymer) were added and mixed to obtain a slurry. The pulp used was a CSF adjusted to 200 ml by beating. The pulp concentration in the slurry is 2%, the deodorant particle concentration is 3% with respect to the pulp, the wet paper strength agent concentration is 0.5% with respect to the pulp, and the polymer flocculant concentration is 0 with respect to the pulp. It was 1%. Using this slurry as a raw material, a particle adhering sheet of 25 cm × 25 cm was obtained by a handsheet paper machine. The basis weight was 30 g / m ² . This sheet was cut into 20 cm × 20 cm to obtain a particle-adhered sheet 1. The amount of deodorant particles in the particle-adhered sheet 1 was 20 mg.

And the model absorbent article of the structure shown in FIG. 4 was produced using this particle adhesion sheet. Specifically, 2 g of the pulp fiber aggregate 13 was used as the constituent fiber of the absorbent body 10, and 2 g of the superabsorbent polymer was dispersed and supported on the aggregate 13. This was wrapped with the particle adhesion sheet 1 and further wrapped with a mount 14 to form the absorbent body 10.
Then, the absorbent body 10 was wrapped so as to be sandwiched between the top sheet 11 and the back sheet 12. In this way, a model absorbent article was produced. The points that are not particularly described are the same as those in Example 1-1.

[Example 3-2]
It is the same as Example 3-1 except that the concentration of the deodorizing particles is 6% with respect to the pulp and the amount of the deodorizing particles in the particle-adhering sheet 1 is 36 mg.

[Example 3-3]
It is the same as Example 3-1 except that the concentration of the deodorizing particles is 10% with respect to the pulp and the amount of the deodorizing particles in the particle-adhered sheet 1 is 60 mg.

  Examples 1-1 to 1-3 and Examples 3-1 to 3-3 were evaluated by the above-mentioned [Method for evaluating deodorizing ability]. The evaluation results are shown in Table 1 and Table 2 below.

  As is clear from the results shown in Tables 1 and 2, the deodorant particles are supported on the constituent fibers of the absorber in the form of particles (Examples 1-1 to 1-3), and the deodorant particles are particles. It turns out that the same deodorizing ability is acquired with the form (Examples 3-1 to 3-3) included in the adhesion sheet.

Example 4
Deodorized particles were obtained by the oil-in-water suspension polymerization method shown below. 100 g of monomer (divinylbenzene / 2-vinylpyridine = 75% / 25%) and 3 g of lauroyl peroxide were dissolved in 30 g of toluene and 20 g of t-butanol, and 1.5 g of sodium N-stearyl taurate was dissolved therein. 500 g of water was added to the polymerization tank. The solubility parameters of the monomer mixture and the organic solvent are 9.37 (cal / cm ³ ) ^1/2 and 9.40 (cal / cm ³ ) ^1/2 , respectively, and the difference is 0.03 (cal / cm ³ ). ^1/2 . Thereafter, the mixed liquid prepared was emulsified by stirring at 10,000 rpm for 5 minutes using a homogenizer, and this was polymerized by heating at 55 ° C. for 4 hours and at 65 ° C. for 3 hours under a stirring condition of 200 rpm. Water and the organic solvent were removed by filtration and dried to obtain deodorized particles. The volume average diameter of the deodorant particles was 5.3 μm. 100 g of the obtained deodorant particles were added to 100 g of ethanol in which 0.5 g of silver nitrate was dissolved, and a supporting treatment was performed at room temperature for 6 hours. This was filtered and then washed with water to obtain silver nitrate-supported deodorant particles. The obtained deodorant particles had a BET specific surface area of 18.3 m ² / g and a silver ion content of 0.14%.
A model absorbent article was prepared in the same manner as in Example 1-1 except that the production method of the deodorant particles was different and the amount of the deodorant particles was 50 mg, and evaluated by the above [deodorization ability evaluation method]. did. The evaluation results are shown in Table 3 below.

It is a perspective view which shows the particle adhesion sheet in one Embodiment of the absorbent article of this invention. It is a perspective view which shows the state which coat | covered the absorber with the particle adhesion sheet shown in FIG. It is sectional drawing of the width direction of the absorbent article produced in Example 1-1. It is sectional drawing of the width direction of the absorbent article produced in Example 3-1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Particle adhesion sheet 2,3 Pulp sheet 4 Inner layer sheet 10 Absorber 11 Top sheet 12 Back sheet

Claims (5)

Obtained by copolymerizing a monomer component containing a crosslinkable vinyl monomer and a vinyl monomer having a heteroaromatic ring ,
The ratio of the crosslinkable vinyl monomer in all monomer components is 50 to 98% by mass, the ratio of the vinyl monomer having the heteroaromatic ring is 2 to 50% by mass,
A deodorizing particle having a BET specific surface area of 300 to 800 m ² / g and containing silver ions ,
It has a top sheet, a back sheet, and an absorber disposed between both sheets,
The deodorizing particles are absorbent articles that are carried on constituent fibers of the absorber in the form of particles . 2. The product obtained by copolymerizing the monomer component containing an aromatic vinyl monomer copolymerizable with these monomers in addition to the crosslinkable vinyl monomer and the vinyl monomer having a heteroaromatic ring. The absorbent article as described. The absorbent article according to claim 2, wherein the crosslinkable vinyl monomer is divinylbenzene, the vinyl monomer having a heteroaromatic ring is 2-vinylpyridine, and the aromatic vinyl monomer is styrene. The absorptive article according to any one of claims 1 to 3 whose particle size is 0.1-10 micrometers. The absorbent article according to any one of claims 1 to 4, wherein a supported amount of silver ions is 0.1 to 5 mass% with respect to the deodorant particles.

Images