JP2015089487A - Method for manufacturing antibacterial sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antibacterial sheet manufacturing method effectively preventing an occurrence of clogging caused by large objects of benzalkonium salts.SOLUTION: The antibacterial sheet manufacturing method includes a step of spraying water-based coating liquid containing benzalkonium-salt-based poorly water-soluble antibacterial agent and basic compound and having pH of 6.5 or more, to a fiber sheet including cellulose fibers. Preferably, anion may be an anionic active group including 6-20C linear or branched alkyl group or alkenyl group, and more preferably, alkyl phosphate.

Description

  The present invention relates to a method for producing an antibacterial sheet. The present invention also relates to an antibacterial sheet produced by the production method and an absorbent article having the antibacterial sheet.

  Benzalkonium salt is a quaternary alkylbenzylammonium salt and is known as an antibacterial agent. Various proposals have been made to incorporate benzalkonium salts into absorbent articles such as disposable diapers and sanitary napkins to develop deodorant and antibacterial effects. For example, Patent Document 1 describes that a fiber sheet covering an absorbent core in an absorbent article contains a quaternary ammonium salt. Patent Documents 2 and 3 describe that a sweat absorbent sheet is disposed on a disposable diaper and that the sweat absorbent sheet contains a benzalkonium salt for the purpose of preventing the occurrence of blisters.

JP 2006-191966 A JP 2007-301346 A JP 2007-325915 A

  By the way, the benzalkonium salt is difficult to dissolve in water depending on the type of anion to be paired. Therefore, when such a poorly water-soluble benzalkonium salt is contained in the sheet, the benzalkonium salt is dispersed in water. The liquid is often applied to the sheet by an external addition method such as spraying. However, when a poorly water-soluble benzalkonium salt is dispersed in water, as the concentration of the benzalkonium salt increases, a large number of coarse substances due to poor dispersion are generated. In addition, when a benzalkonium salt is dissolved in water containing metal ions such as calcium and magnesium, a coarse product made of scum is generated due to the metal soap generated thereby. As a result, there is a problem that the strainer is easily clogged due to the coarse material. In addition, when spraying an aqueous dispersion, there is also a problem that the spray nozzle is easily clogged and it is difficult to perform stable spraying.

  Therefore, the subject of this invention is providing the manufacturing method of the antimicrobial sheet which can eliminate the fault which the prior art mentioned above has.

  The present invention sprays an aqueous coating solution containing a poorly water-soluble antibacterial agent and a basic compound represented by the following formula (1) and having a pH of 6.5 or more onto a fiber sheet containing cellulose fibers. The manufacturing method of the antimicrobial sheet which has a process is provided.

  The present invention also provides an antibacterial sheet having a first surface and a second surface located on the opposite side, and manufactured by the above manufacturing method.

  Furthermore, this invention provides the absorbent article which has the said antimicrobial sheet.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the antimicrobial sheet in which generation | occurrence | production of the clogging resulting from the coarse thing of a benzalkonium salt was prevented effectively is provided.

FIG. 1 is a schematic diagram showing an apparatus for preparing an aqueous coating solution that is suitably used for carrying out the production method of the present invention. FIG. 2 is a schematic view showing an aqueous coating solution spraying apparatus suitably used for carrying out the production method of the present invention. FIG. 3 is a schematic view showing an application example of the antibacterial sheet obtained by the production method of the present invention.

  The present invention will be described below based on preferred embodiments with reference to the drawings. In the present invention, a water-based coating solution containing a poorly water-soluble antibacterial agent represented by the above formula (1) (hereinafter also simply referred to as “antibacterial agent”) is sprayed on a fiber sheet to obtain a target antibacterial sheet. obtain. As the fiber sheet to which the antibacterial agent is applied, a sheet containing cellulose fibers is used. Examples of the cellulose fiber include natural cellulose fibers such as wood pulp such as softwood kraft pulp and hardwood kraft pulp, cotton pulp, and straw pulp. Alternatively, regenerated cellulose fibers such as rayon and cupra can be used. Furthermore, semi-synthetic cellulose fibers such as acetate can also be used.

  Bulky cellulose fibers can also be used as the cellulose fibers. In the present specification, the term “bulky fiber” means that the fiber shape has a three-dimensional structure such as a twisted structure, a crimped structure, a bent and / or branched structure, or the fiber cross section is extremely thick (for example, the fiber roughness is 0. 0). 3 mg / m or more). Examples of preferred bulky cellulose fibers include fiber roughness of 0.3 mg / m or more, particularly 0.32 mg / m or more, 2 mg / m or less, especially 1 mg / m or less, especially 0.32 mg / m or more. Examples include cellulose fibers of 1 mg / m or less. “Fiber roughness” is used as a measure of fiber thickness in fibers with non-uniform fiber thickness, such as wood pulp. For example, a fiber roughness meter (FS-200, AJANI ELECTRONICS LTD.). Examples of cellulose fibers with a fiber roughness of 0.3 mg / m or more include softwood kraft pulp (“ALBACEL” (trade name) from Federal Paper Board Co. and “INDORAYON” (trade name) from PT Inti Indorayon Utama. )] And the like.

  Other examples of preferred bulky cellulose fibers include cellulose fibers having a roundness of the fiber cross section of preferably 0.5 or more, more preferably 0.55 or more, and preferably 1 or less. . Cellulose fibers having a roundness of the fiber cross section of 0.5 or more and 1 or less are preferable because the liquid movement resistance is small and the liquid permeation rate is high. The roundness of the fiber cross section can be measured, for example, by the method described in JP-A-8-246395.

  In general, the cross section of wood pulp is flattened by delignification treatment, and most of its roundness is less than 0.5. In order to make the roundness of such wood pulp 0.5 or more, for example, such wood pulp may be mercerized to swell the cross section of the wood pulp. Thus, as the bulky cellulose fiber, mercerized pulp having a roundness of 0.5 or more and 1 or less obtained by mercerizing wood pulp is also preferable. Examples of commercially available mercerized pulp that can be used in the present invention include “FILTRANIER” (trade name) manufactured by ITT Rayonier Inc. and “POROSANIER” (trade name) manufactured by the same company. In addition, when a cellulose fiber having a fiber roughness of 0.3 mg / m or more and a roundness of the fiber cross section of 0.5 or more and 1 or less is used, a bulky network structure is more easily formed, and the liquid can pass therethrough. This is preferable because the speed is further increased.

  As another example of the bulky cellulose fiber, there is a crosslinked cellulose fiber obtained by crosslinking cellulose molecules within and / or between molecules. Such a crosslinked cellulose fiber has a feature that it can maintain a bulky structure even in a wet state. Although there is no restriction | limiting in particular in the method for bridge | crosslinking a cellulose fiber, For example, the crosslinking method using a crosslinking agent is mentioned. Examples of such crosslinking agents include N-methylol compounds such as dimethylolethyleneurea and dimethyloldihydroxyethyleneurea; polycarboxylic acids such as citric acid, tricarballylic acid and butanetetracarboxylic acid; polyols such as dimethylhydroxyethyleneurea A cross-linking agent for polyglycidyl ether compounds. In particular, a crosslinking agent of a polycarboxylic acid or a polyglycidyl ether compound that does not generate formalin or the like harmful to the human body during crosslinking is preferable.

  These various cellulose fibers can be used alone or in combination of two or more. Cellulose fibers having an appropriate fiber length are used depending on the fiber sheet production method and the specific use of the antibacterial sheet. For example, when a fiber sheet is produced by a wet papermaking method, the fiber length of the cellulose fiber is preferably 1 mm or more and 20 mm or less.

  The fiber sheet may be composed only of the above-described cellulose fibers, or may contain other fibers in addition to the cellulose fibers. Examples of other fibers include heat-fusible fibers. As the heat-fusible fiber, fibers that melt by heating and adhere to each other can be used. Specific examples of the heat-fusible fiber include polyolefin fibers such as reethylene, polypropylene and polyvinyl alcohol, polyester fibers, polyethylene-polypropylene composite fibers, polyethylene-polyester composite fibers, low melting point polyester-polyester composite fibers, and fiber surfaces. Examples thereof include hydrophilic polyvinyl alcohol-polypropylene composite fibers and polyvinyl alcohol-polyester composite fibers. When using a composite fiber, any of a core-sheath type composite fiber and a side-by-side type composite fiber can be used. These heat-fusible fibers can be used alone or in combination of two or more.

  The heat-fusible fiber has a fineness of 0.1 dtex or more, particularly 0.5 dtex or more, and preferably 3 dtex or less. Moreover, when manufacturing a fiber sheet, for example with a wet papermaking method, it is preferable that the heat-fusible fiber generally has a fiber length of 2 mm or more and 60 mm or less. Furthermore, it is preferable that the heat-fusible fiber is contained in the fiber sheet in an amount of 1% by mass to 30% by mass.

  The fiber sheet may contain other components in addition to the fiber components described above. Examples of other components include paper strength reinforcing agents. As the paper strength reinforcing agent, for example, polyamine / epichlorohydrin resin, dialdehyde starch, sponge, carboxymethylcellulose and the like can be used. These paper strength reinforcing agents can be used singly or in combination of two or more. The paper strength reinforcing agent is preferably contained in the fiber sheet in an amount of 0.01% by mass to 30% by mass, particularly 0.01% by mass to 20% by mass.

  As long as the cellulose fiber mentioned above is contained, the fiber sheet may have a single layer structure or a multilayer structure. Alternatively, the fiber sheet may be a stack of a plurality of sheets of two or more plies, and any one of the plurality of sheets may contain cellulose fibers.

A fiber sheet having an appropriate basis weight is used depending on the specific use of the antibacterial sheet. For example, when the antibacterial sheet is used for covering the absorbent core in the absorbent article, the basis weight of the fiber sheet is 8 g / m ² or more, particularly 13 g / m ² or more, and 45 g / m ² or less, particularly 20 g. / M ² or less is preferable.

As described above, the antibacterial agent contained in the aqueous coating solution applied to the fiber sheet is represented by the formula (1). In the present invention, one of the compounds represented by formula (1) can be used alone or in combination of two or more. In formula (1), as a preferable combination of R ¹ and R ² , for example, a combination in which R ¹ is a methyl group and R ² is a linear or branched alkyl group having 8 to 20 carbon atoms, Examples include a combination in which ¹ and R ² are the same group and the group is a linear or branched alkyl group having 8 to 20 carbon atoms. In these combinations, the alkyl group preferably has 10 to 18 carbon atoms.

Wherein (1), X ^- a monovalent anion represented by is preferably, for example, halide ions or anions active group. Particularly X ^- if a monovalent anion represented by is an anionic active group, since the antibacterial agents are known to be low solubility in water, in which case employing the manufacturing method of the present invention The effect becomes remarkable. The “anionic active group” refers to an ion having an anionic surface active ability.

  The anionic active group is an anionic active group having 6 or more carbon atoms, particularly 10 or more carbon atoms, and containing a linear or branched alkyl group or alkenyl group having 20 or less carbon atoms, particularly 18 or less carbon atoms. Is preferably used. As such an anion active group, for example, alkyl phosphate ester salt, alkyl carboxylate salt, alkyl sulfonate salt, and alkyl sulfate ester salt are preferably used from the viewpoint of antibacterial activity. In particular, it is preferable to use an alkyl phosphoric acid represented by the following formula (2) from the viewpoint that the antibacterial ability is further enhanced.

In Formula (2), a preferable combination of R ³ and R ^{4 includes} a combination in which R ³ is a hydrogen atom and R ⁴ is a linear or branched alkyl group having 8 to 20 carbon atoms. More preferably, the alkyl group has 10 to 18 carbon atoms.

  The antibacterial agent represented by the formula (1) is poorly water-soluble. In the present specification, “poorly water-soluble” means that a solution obtained by adding 2.0 g of the antibacterial agent to 100 g of pure water at 25 ° C. and stirring the mixture is used for a test sieve having an opening of 106 μm as defined in JIS Z8801-1. It means that the proportion of the mass of the antibacterial agent remaining on the mesh when filtered (hereinafter, this proportion is referred to as “residual rate”) is 3% or more with respect to the initial amount.

  The antibacterial agent is mixed with water to obtain an aqueous coating solution. Since the antibacterial agent is sparingly soluble in water, even if it is mixed with water, it may not be completely dissolved in water. However, as will be described later, by adjusting the pH of the aqueous coating solution, it is possible to effectively prevent the generation of a coarse product composed of the undissolved antibacterial agent. The concentration of the antibacterial agent in the aqueous coating solution is preferably 0.2% by mass or more, and more preferably 0.4% by mass or more, from the viewpoint of imparting sufficient antibacterial properties to the antibacterial sheet. . Further, from the viewpoint of preventing the viscosity of the aqueous coating solution from excessively increasing, the concentration of the antibacterial agent is preferably 3% or less, and more preferably 2% or less. Specifically, the concentration of the antibacterial agent is preferably 0.2% by mass or more and 3% by mass or less, and more preferably 0.4% by mass or more and 2% by mass or less.

  The aqueous coating solution containing the antibacterial agent preferably has a pH adjusted to 6.5 or higher, particularly 7.0 or higher. By setting the pH of the aqueous coating solution to be equal to or higher than this value, it is effectively prevented that a coarse product composed of the undissolved antibacterial agent is generated in the aqueous coating solution. The inventor believes that this is because dissociation between the cation moiety and the anion moiety in formula (1) is promoted by increasing the pH of the aqueous coating solution. The higher the pH of the aqueous coating solution is, the more preferable it is because the formation of a coarse product composed of the antibacterial agent is suppressed. However, if the pH is excessively high, dissolution of the antibacterial agent proceeds excessively, and the viscosity of the aqueous coating solution tends to increase rapidly. Therefore, in the present invention, the upper limit of the pH of the aqueous coating solution is preferably 9.0, particularly 8.5. Thus, the pH of the aqueous coating solution in the present invention is preferably 6.5 or more and 9.0 or less, and more preferably 7.5 or more and 8.5 or less. Since the pH of the aqueous coating solution depends on the temperature, the pH of the aqueous coating solution referred to in the present invention is the pH at the temperature of the aqueous coating solution when the aqueous coating solution is applied to the fiber sheet.

  In order to set the pH of the aqueous coating solution in the above-described range, it has been found by the inventors that it is effective to contain a basic compound in the aqueous coating solution. Examples of basic compounds include carbonates, bicarbonates, ammonia, and metal hydroxides. These basic compounds can be used alone or in combination of two or more. Of these basic compounds, from the viewpoint of low irritation to the skin, carbonates and bicarbonates are preferably used, and carbonates are particularly preferably used. As the carbonate, for example, an alkali metal carbonate such as sodium carbonate is preferably used from the viewpoint of lower irritation to the skin. The concentration of the basic compound contained in the aqueous coating solution is adjusted so that the pH of the aqueous coating solution becomes the above value. Further, in a working environment where the aqueous coating solution is sprayed, there are cases where it is desired to keep the pH low and to change from the alkaline side to the neutral side due to safety issues. In that case, within the above-mentioned pH range, after the coarse product composed of the antibacterial agent undissolved by the basic compound is effectively prevented from the aqueous coating solution, the pH is adjusted using an appropriate acidic substance. It can be adjusted appropriately.

  It is also preferable to contain a chelating agent in the aqueous coating solution. This is because the chelating agent forms a complex with a metal ion that may be contained as an impurity in the aqueous coating solution and suppresses the formation of scum caused by the antibacterial agent. From this viewpoint, the concentration of the chelating agent contained in the aqueous coating solution is preferably 0.1% by mass or more, particularly preferably 0.5% by mass or more. Moreover, it is preferable to set it as 2.0 mass% or less, especially 1.5 mass% or less. The concentration of the chelating agent contained in the aqueous coating solution is preferably 0.1% by mass or more and 2.0% by mass or less, and particularly preferably 0.5% by mass or more and 1.5% by mass or less.

  Examples of chelating agents include aminotri (methylenephosphonic acid), 1-hydroxyethylidene-1-diphosphonic acid, ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid), and salts thereof, 2-phosphonocarboxylic acid An organic acid or salt thereof such as aminopolyacetic acid or salt thereof such as acid or salt thereof, aspartic acid or salt thereof, amino acid or salt thereof such as glutamic acid or salt thereof, nitrilotriacetic acid or salt thereof, ethylenediaminetetraacetic acid or salt thereof; Examples thereof include citric acid or a salt thereof, pyro- and triphosphate. These chelating agents can be used alone or in combination of two or more.

When the aqueous coating solution contains a chelating agent in the aqueous coating solution of the present invention, metal ions capable of forming metal soap in the aqueous coating solution, for example, alkaline earth metal elements such as calcium ions and magnesium ions. Even when ions are included, scum generation is effectively suppressed. Therefore, water having high hardness can be used as the water used in the aqueous coating solution. The concentration of alkaline earth metal element ions varies depending on the source of water such as river water and groundwater and the sampling location, but in the present invention, even if the water used for the aqueous coating solution has a high hardness exceeding 100 mg CaCO ₃ / L. If the concentration of the chelating agent contained in the aqueous coating solution is within the above range, the formation of scum can be effectively suppressed.

  The aqueous coating solution preferably has a viscosity of 80 mPa · s, particularly 65 mPa · s or less, particularly 20 mPa · s or less. By setting the viscosity below this value, the aqueous coating solution can be successfully sprayed onto the fiber sheet. Since the viscosity of the aqueous coating solution depends on the temperature, the viscosity of the aqueous coating solution referred to in the present invention is the viscosity at the temperature of the aqueous coating solution when the aqueous coating solution is applied to the fiber sheet. The viscosity of the aqueous coating solution can be adjusted by the concentration of the antibacterial agent and the pH of the aqueous coating solution. The viscosity of the aqueous coating solution is measured using a B-type viscometer TVB-10M (manufactured by Toki Sangyo Co., Ltd.).

  1 and 2 show an example of an apparatus for applying an aqueous coating liquid to a fiber sheet. As shown in FIG. 1, water, the antibacterial agent, and the basic compound that are components of the aqueous coating solution are charged into the stock solution tank 10, and a chelating agent is further charged as necessary. By thoroughly mixing these components using the stirring blade 11, a stock solution of an aqueous coating solution is prepared. The stock solution stored in the stock solution tank 10 is diluted with the dilution water W when it is transferred to the dilution tank 12. The aqueous coating solution obtained by diluting the stock solution with the dilution water W is sufficiently mixed in the dilution tank 12 using the stirring blade 13. The aqueous coating solution thus obtained passes through the strainer 14 to remove coarse substances, and is sent to the spray nozzle 16 by the pump 15.

  As shown in FIG. 2, the fiber sheet 20 that has been wet-made by a paper-making process (not shown) is transported to the transport belt 21 in a wet state and introduced into the Yankee dryer 22. A touch roll 23 is disposed at the introduction portion of the Yankee dryer 22 so as to face the peripheral surface of the Yankee dryer 22. The fiber sheet 20 is guided to the touch roll 23 together with the conveying belt 21 and introduced into the Yankee dryer 22. Then, immediately before the fiber sheet 20 is introduced into the Yankee dryer 22, the aqueous coating liquid sprayed from the spray nozzle 16 is applied to one surface of the fiber sheet 20 while being held on the peripheral surface of the touch roll 23. The Thus, in this step, the aqueous coating liquid is applied by spraying only from one surface (for example, the first surface) of the fiber sheet 20 having the first surface and the second surface located on the opposite side.

  The fiber sheet 20 to which the aqueous coating solution is applied is held on the peripheral surface of the Yankee dryer 22 while being wet and is conveyed. And it heats during the conveyance, a water | moisture content is removed, and it dries. The antibacterial sheet 24 thus obtained is peeled off from the peripheral surface of the Yankee dryer 22 by the doctor blade 25.

  The antibacterial sheet 24 obtained by the above method has a greater amount of the antibacterial agent on the first surface side, which is the application surface of the aqueous coating liquid, than the second surface of the first surface and the second surface. It exists. This is because the antibacterial agent is not completely dissolved in the aqueous coating solution, and undissolved aggregates are present in the aqueous coating solution. This is because the undissolved aggregate does not penetrate into the fiber sheet and remains on the surface of the spray surface, that is, the surface of the first surface.

Such antibacterial sheet 24 obtained by, the said antimicrobial agent 1.0 mg / ^{m 2} or more, it is preferable from the viewpoint of sufficient antibacterial expression that contains especially 2.5 mg / ^{m 2} or more. The upper limit of the content of the antibacterial agent is preferably 50.0 mg / m ² or less, particularly preferably 20.0 mg / m ² or less. The content of the antimicrobial agent, for example 1 mg / ^{m 2} or more 50.0 mg / ^{m 2} or less, and particularly preferably 2.5 mg / ^{m 2} or more 20.0 mg / ^{m 2} or less.

  The antibacterial sheet 24 can be applied to various fields using its antibacterial performance. FIG. 3 shows an example when the antibacterial sheet 24 is applied to an absorbent article such as a disposable diaper or a sanitary napkin. In the figure, an embodiment using an antibacterial sheet 24 as a covering sheet 31 covering the entire surface of the absorbent core 30 of the absorbent article is shown. The absorbent core 30 is configured to include liquid-absorbing fibers such as fluff pulp, or liquid-absorbing fibers and a superabsorbent polymer. Of the surfaces of the absorbent core 30, at least the surface facing the wearer's skin is covered with the antibacterial sheet 24. In this case, disposing the first surface 241 of the antibacterial sheet 24, that is, the surface on the side where a large amount of the antibacterial agent is present so as to face the wearer's skin, is the point of effectively expressing the antibacterial effect To preferred. The absorbent article generally includes a liquid-permeable top sheet, a liquid-impermeable or hardly-permeable back sheet, and a liquid-retaining absorbent disposed between the two sheets.

  As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the said embodiment. For example, in the above-described embodiment, the water-based coating liquid is applied only to one of the first surface and the second surface of the fiber sheet 20, that is, only to the first surface. An aqueous coating solution may be applied to both of the second surfaces.

  Moreover, in the said embodiment, although the example which applied the antibacterial sheet 24 to the absorbent article was given, the use which needs antibacterial property, for example, food packaging, in order to prevent the growth of other fungi and molds The antibacterial sheet 24 may be applied to materials, trays, air-conditioning filters, flooring materials, building materials such as wall materials, medical masks, sheets, gloves, clothing, wet tissues, disinfecting cleaners, and wiping sheets.

＜２＞
前記式（１）において、Ｒ^１がメチル基であり、Ｒ^２が炭素数８以上２０以下の直鎖又は分岐鎖のアルキル基であり、
前記アルキル基の炭素数は、１０以上１８以下であることが更に好ましい前記＜１＞に記載の抗菌性シートの製造方法。
＜３＞
前記式（１）において、Ｒ^１及びＲ^２が同一の基であり、かつ該基が炭素数８以上２０以下の直鎖又は分岐鎖のアルキル基であり、
アルキル基の炭素数は、１０以上１８以下であることが更に好ましい前記＜１＞に記載の抗菌性シートの製造方法。
＜４＞
２５℃の純水１００ｇに２．０ｇの前記水難溶性抗菌剤を添加し撹拌した液を、ＪＩＳ Ｚ ８８０１−１で規定される目開き１０６μｍの試験用ふるいで濾過したときに、メッシュ状に残る該水難溶性抗菌剤の量の割合が、初めの量に対して３％以上である前記＜１＞ないし＜３＞のいずれか１に記載の抗菌性シートの製造方法。
＜５＞
前記式（１）中、Ｘ⁻で表される一価のアニオンが、ハロゲン化物イオン又はアニオン活性基である前記＜１＞ないし＜４＞のいずれか１に記載の抗菌性シートの製造方法。 In relation to the above-described embodiment, the present invention further discloses the following method for producing an antibacterial sheet.
<1>
An aqueous coating solution containing a poorly water-soluble antibacterial agent and a basic compound represented by the following formula (1) and having a pH of 6.5 or more, particularly 7.0 or more is applied to a fiber sheet containing cellulose fibers. A method for producing an antibacterial sheet having a spraying step.

<2>
In the formula (1), R ¹ is a methyl group, R ² is a linear or branched alkyl group having 8 to 20 carbon atoms,
The method for producing an antibacterial sheet according to <1>, wherein the alkyl group preferably has 10 to 18 carbon atoms.
<3>
In the formula (1), R ¹ and R ² are the same group, and the group is a linear or branched alkyl group having 8 to 20 carbon atoms,
The method for producing an antibacterial sheet according to <1>, wherein the carbon number of the alkyl group is more preferably 10 or more and 18 or less.
<4>
When a solution obtained by adding 2.0 g of the poorly water-soluble antibacterial agent to 100 g of pure water at 25 ° C. and stirring is filtered through a test sieve having an aperture of 106 μm defined in JIS Z8801-1, it remains in a mesh shape. The method for producing an antibacterial sheet according to any one of <1> to <3>, wherein the ratio of the amount of the poorly water-soluble antibacterial agent is 3% or more with respect to the initial amount.
<5>
The method for producing an antibacterial sheet according to any one of <1> to <4>, wherein the monovalent anion represented by X ⁻ in the formula (1) is a halide ion or an anion active group.

<6>
X in Formula (1) ^- is a linear or manufacturing method of antimicrobial sheet according to any one of from the <1> not an anionic active group containing an alkyl or alkenyl group branched <5> .
<7>
The method for producing an antibacterial sheet according to <5> or <6>, wherein the anion active group has 6 or more carbon atoms, particularly 10 or more carbon atoms, 20 or less carbon atoms, and particularly 18 or less carbon atoms.
<8>
X in Formula (1) ^- is 6 or more carbon atoms and 20 or less, preferably to the <1> not an anionic active group containing an alkyl group or an alkenyl group of straight or branched chain having 10 to 18 carbon atoms The method for producing an antibacterial sheet according to any one of <7>.
<9>
The method for producing an antibacterial sheet according to any one of <5> to <8>, wherein the anion active group is an anion having an anionic surface active ability.
<10>
X in Formula (1) ^- is an alkyl phosphate ester salt, alkyl carboxylates, antibacterial sheet according to any one of from the <1> to an alkyl sulfonate or alkyl sulfate <9> Manufacturing method.

＜１２＞
前記式（２）中、Ｒ^３が水素原子であり、Ｒ^４が炭素数８以上２０以下、好ましくは炭素数１０以上１８以下の直鎖又は分岐鎖のアルキル基である前記＜１１＞に記載の抗菌性シートの製造方法。
＜１３＞
前記式（２）中、Ｒ^３が水素原子であり、Ｒ^４が炭素１６の直鎖又は分岐鎖のアルキル基である前記＜１２＞に記載の抗菌性シートの製造方法。
＜１４＞
前記水系塗布液中の前記水難溶性抗菌剤の濃度が、０．２質量％以上であることが好ましく、０．４質量％以上であることが更に好ましく、また前記水難溶性抗菌剤の濃度は３％以下であることが好ましく、２％以下であることが更に好ましい前記＜１＞ないし＜１３＞のいずれか１に記載の抗菌性シートの製造方法。
＜１５＞
前記水系塗布液中の前記水難溶性抗菌剤の濃度が、０．２質量％以上３質量％以下、好ましくは０．４質量％以上２％質量％以下である前記＜１＞ないし＜１４＞のいずれか１に記載の抗菌性シートの製造方法。
＜１６＞
前記水系塗布液のｐＨが９．０以下、特に８．５以下である前記＜１＞ないし＜１５＞のいずれか１に記載の抗菌性シートの製造方法。 <11>
The method for producing an antibacterial sheet according to any one of <1> to <10>, wherein X ⁻ in the formula (1) is an alkyl phosphoric acid represented by the following formula (2).

<12>
In the above formula (2), R ³ is a hydrogen atom, and R ⁴ is a linear or branched alkyl group having 8 to 20 carbon atoms, preferably 10 to 18 carbon atoms, Manufacturing method of antibacterial sheet.
<13>
In the above formula (2), R ³ is a hydrogen atom, a manufacturing method of antimicrobial sheet according to the R ⁴ is a straight or branched chain alkyl group having a carbon 16 <12>.
<14>
The concentration of the poorly water-soluble antibacterial agent in the aqueous coating solution is preferably 0.2% by mass or more, more preferably 0.4% by mass or more, and the concentration of the poorly water-soluble antibacterial agent is 3. % Or less, and more preferably 2% or less. The method for producing an antibacterial sheet according to any one of <1> to <13>.
<15>
<1> to <14>, wherein the concentration of the poorly water-soluble antibacterial agent in the aqueous coating solution is 0.2% by mass or more and 3% by mass or less, preferably 0.4% by mass or more and 2% by mass or less. The manufacturing method of the antibacterial sheet of any one.
<16>
The method for producing an antibacterial sheet according to any one of <1> to <15>, wherein the pH of the aqueous coating solution is 9.0 or less, particularly 8.5 or less.

<17>
The antibacterial sheet according to any one of <1> to <16>, wherein the basic compound is one or more selected from carbonates, bicarbonates, ammonia, and metal hydroxides. Method.
<18>
The method for producing an antibacterial sheet according to any one of <1> to <17>, wherein the basic compound is a carbonate.
<19>
The method for producing an antibacterial sheet according to <18>, wherein the carbonate is an alkali metal carbonate such as sodium carbonate.
<20>
The method for producing an antibacterial sheet according to any one of <1> to <19>, wherein the aqueous coating solution further contains a chelating agent.
<21>
The concentration of the chelating agent contained in the aqueous coating solution is preferably 0.1% by mass or more, particularly preferably 0.5% by mass or more, and 2.0% by mass or less, particularly 1.5% by mass or less. The method for producing an antibacterial sheet according to <20>, preferably.

<22>
The chelating agent is aminotri (methylenephosphonic acid), 1-hydroxyethylidene-1-diphosphonic acid, ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid), and salts thereof, 2-phosphonocarboxylic acid And salts thereof, amino acids such as aspartic acid and salts thereof, glutamic acid and salts thereof, salts thereof, nitrilotriacetic acid and salts thereof, aminopolyacetic acids such as ethylenediaminetetraacetic acid and salts thereof, and organic acids and salts thereof such as The method for producing an antibacterial sheet according to <20> or <21>, which is one or more selected from acids and salts thereof, and pyro- and triphosphates.
<23>
The method for producing an antibacterial sheet according to any one of <1> to <22>, wherein the aqueous coating solution further contains ethylenediaminetetraacetic acid or a salt thereof.
<24>
The method for producing an antibacterial sheet according to any one of <20> to <23>, wherein water used for the aqueous coating solution has a hardness exceeding 100 mg CaCO ₃ / L.
<25>
Any of the above <1> to <24>, wherein the viscosity of the aqueous coating solution at the time of applying the aqueous coating solution to the fiber sheet is 80 mPa · s, particularly 65 mPa · s or less, particularly 20 mPa · s or less. 1. A method for producing an antibacterial sheet according to 1.
<26>
The antibacterial sheet according to any one of <1> to <25>, wherein the aqueous coating liquid is sprayed only on the first surface of the fiber sheet having the first surface and the second surface located on the opposite side. Production method.

<27>
The method for producing an antibacterial sheet according to <26>, including a step of mixing and stirring water, the antibacterial agent, and the basic compound that are components of the aqueous coating solution before the spraying step.
<28>
The method for producing an antibacterial sheet according to <26> or <27>, further including a step of introducing the fiber sheet into a Yankee dryer after the spraying step.
<29>
The antibacterial sheet which has the 1st surface and the 2nd surface located on the opposite side, and was manufactured by the manufacturing method of any one of said <1> thru | or <28>.
<30>
The antibacterial sheet according to <29>, which contains 1 mg / m ² or more of the poorly water-soluble antibacterial agent.
<31>
The antibacterial sheet, the antibacterial agent 1 mg / ^{m 2} or more, in particular contains 2.5 mg / ^{m 2} or more, and 50.0 mg / ^{m 2} or less, particularly 20.0 mg / ^{m 2} or less comprise that the < The antibacterial sheet according to 29> or <30>.

<32>
The antibacterial sheet according to any one of <29> to <31>, wherein the poorly water-soluble antibacterial agent is present more on the first surface side than the second surface.
<33>
An absorbent article comprising the antibacterial sheet according to any one of <29> to <32>.
<34>
The absorbent article according to <33>, wherein the first surface of the antibacterial sheet is disposed so as to face the wearer's skin.
<35>
The absorbent article according to <33> or <34>, wherein the absorbent article has a liquid-retaining absorbent core, and the surface of the absorbent core that faces the wearer's skin is covered with the antibacterial sheet. .
<36>
The absorbent article according to <35>, wherein the basis weight of the fiber sheet is 8 g / m ² or more, particularly 13 g / m ² or more, and 45 g / m ² or less, particularly 20 g / m ² or less.

  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. Unless otherwise specified, “%” means “mass%”.

[Example 1]
(1) Preparation of aqueous coating solution Benzalkonium cetyl phosphate ("Sanisol P" (registered trademark) of Kao Corporation) was used as a poorly water-soluble antibacterial agent. The residual ratio of this antibacterial agent was 3.7%. Sodium carbonate was used as the basic compound. As the chelating agent, sodium ethylenediaminetetraacetate (EDTA) was used. These were mixed with groundwater to obtain an aqueous coating solution. The hardness of this groundwater was 75 mgCaCO ₃ / L. The concentration of each component in the aqueous coating solution is as shown in Table 1. The pH and viscosity of the aqueous coating solution are also as shown in the same table. The coarse 100 μm mesh residue rate measured for each aqueous coating solution is also as shown in the table. The mesh residue ratio is obtained by filtering the aqueous dispersion with a mesh having an opening of 100 μm, drying the coarse product separated by filtration, measuring its mass, and dividing the measured mass by the mass of the aqueous dispersion before filtration. And further multiplied by 100. The results of visual observation of the appearance of each aqueous coating solution are also shown in the table.

(2) Manufacture of fiber sheet Wet papermaking was carried out using a paper stock containing 90% of softwood kraft pulp and 10% of hardwood kraft pulp as a raw material, and paper having a basis weight of 14 g / m ² was manufactured. This paper was used as a fiber sheet.

(3) Production of antibacterial sheet An antibacterial sheet was produced using the apparatus shown in FIGS. 1 and 2. The mesh of the strainer mesh was 100 μm.

(4) Evaluation of production stability (after 2 hours) The production of the antibacterial sheet was visually evaluated for the occurrence of clogging of the spray nozzle and the strainer. The case where clogging was not observed was indicated by “◯”, the case where slight clogging was observed was indicated by “Δ”, and the case where clogging was observed significantly was indicated by “X”. The results are shown in Table 1. Furthermore, the yield of the antibacterial agent was calculated. In the calculation, first, the nozzle condition for uniformly applying the aqueous coating solution to the fiber sheet is determined, and the discharge amount A (g / min) per minute of the aqueous coating solution is appropriately determined under the condition that there is no fiber sheet. Weighed in a large container. And the basis weight C of the antibacterial agent per unit area sprayed on the fiber sheet from the concentration B (%) of the antibacterial agent in the aqueous coating solution and the area W (m ² ) of the fiber sheet applied per minute A × B ÷ 100 ÷ W (g / m ² ) was determined. Next, the basis weight D (g / m ² ) of the antibacterial agent actually contained in the antibacterial sheet in the antibacterial sheet after spraying and drying the aqueous coating liquid on the fiber sheet was measured by the method described below. The yield E, which is the ratio remaining in the antibacterial sheet with respect to the sprayed amount of the antibacterial agent, was obtained from the equation E = D / C × 100 (%). The cause of the decrease in the yield of the antibacterial agent is that the spray liquid is dissipated by the turbulent air flow caused by the rotation of the Yankee dryer 22 while a part of the spray liquid of the aqueous coating liquid reaches the fiber sheet 20 from the nozzle 16. The conveying belt 21 (not substantially coated on the fiber sheet 20 or when being niped by the touch roll 23 passes through the fiber sheet and is in contact with the back surface of the coated surface when the water-based coating liquid sprays. It is thought to penetrate into the blanket.

(5) Evaluation of antibacterial sheet The amount of the antibacterial agent contained in the antibacterial sheet was measured with a liquid chromatograph / mass spectrometer (6140 LC / MS manufactured by Agilent, ionization method: ESI). First, in order to prepare a calibration curve, about 0.05 g of an active ingredient of an antibacterial agent was weighed and dissolved in 10 mmol / L acetic acid-containing methanol to make 100 mL (500 μg / mL). This solution was diluted to prepare 0.01, 0.05, 0.1, and 0.5 μg / mL calibration curve solutions as effective components. Next, the 10 cm × 10 cm square antibacterial sheet was immersed in 30 mL of a 10 mmol / L acetic acid-containing methanol solution, irradiated with ultrasonic waves for 10 minutes, and the extract was collected in a 100 mL volumetric flask. This extraction operation was repeated three times and adjusted to 100 mL with the acetic acid-containing methanol. This solution was appropriately diluted 2 to 10 times and filtered through a 0.45 μm membrane filter to obtain a filtrate as an antibacterial sheet extract. The measurement mode was set to selected ion monitoring, and m / z = 276 (C10 M +), 304 (C12 M +), 332 (C14 M +) and 360 (C16 M +) were set as monitoring ions. A calibration curve is created using the total value of the peak areas of C10, C12, C14, and C16 of the calibration curve solution, and the concentration of the antibacterial agent in the extract (μg / mL) from the measurement of the extract of the antibacterial sheet Was converted into basis weight D (g / m ² ) of the antibacterial sheet. In addition, the bacteriostatic activity of the antibacterial sheet was performed for Escherichia coli and Staphylococcus aureus. In the measurement, the bacteriostatic activity of the antibacterial sheet was measured for each of Escherichia coli and Staphylococcus aureus by the microbial liquid absorption method of JIS L 1902 ²⁰⁰⁸ . Specifically, the test bacterial solution is inoculated on a 0.4 g test piece of the antibacterial sheet, and the viable bacterial count (M ₀ ) immediately after the test bacterial solution inoculation and the viable bacterial count after culturing at 37 ° C. for 18 hours ( M _c ) was measured. For the cotton standard white cloth, the number of viable bacteria (M _a ) immediately after inoculation with the test bacterial solution and the number of viable bacteria after culture (M _b ) were similarly measured, and the bacteriostatic activity value S was determined from the following formula. In the formula, “log” is a common logarithm.
_{S = (log 10 M b -log} 10 M a) - (log 10 M c -log 10 M 0)
Furthermore, an absorbent core was produced by coating an absorbent core with an antibacterial sheet, urine was injected into the absorbent body, and the strength of urine odor after being allowed to stand at 36 ° C. for 24 hours was evaluated. The absorptive core was made of a mixed fiber having a basis weight of fluff pulp of 150 g / m ² and a basis weight of superabsorbent polymer of 160 g / m ² , and had a mass of 4.1 g. The antibacterial sheet had a size of 70 cm × 190 cm, and the entire area of the absorbent core was coated so that the spray surface of the aqueous coating liquid faced outward. The evaluation criteria are “5” when the urine odor is strong, “4” when the urine odor is slightly strong, “3” when the urine odor is weak, and “2” when the urine odor is known. The case where the odor was not recognized was set to a slight “1”, and the case where there was no odor was set to “0”. The results are shown in Table 1. In addition, as a standard for urine odor, we also manufactured a fiber sheet that does not spray an aqueous coating solution and does not substantially contain an antibacterial agent. The strength of the body's urine odor was evaluated as “5”.

[Examples 2 to 5 and Comparative Example 1]
As the aqueous coating solution, those shown in Table 1 were used. Except this, it carried out similarly to Example 1, and obtained the antimicrobial sheet. The obtained antibacterial sheet was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 2]
This comparative example is an example in which an antibacterial agent is applied to a fiber sheet by internal addition. An antibacterial sheet was obtained by adding 2.4% of the antibacterial agent to the paper stock for producing the fiber sheet prepared in Example 1 with respect to the mass of the pulp in the stock and performing wet papermaking. . The obtained antibacterial sheet was evaluated in the same manner as in Example 1. Furthermore, the presence or absence of foaming of papermaking white water during wet papermaking was visually evaluated. The case where foaming was not observed was indicated by “◯”, the case where slight foaming was observed was indicated by “Δ”, and the case where foaming was observed significantly was indicated by “X”. The results are shown in Table 1.

  As is clear from the results shown in Table 1, in each Example, it is understood that clogging of the spray nozzle and the strainer is not observed in the production process of the antibacterial sheet, and the antibacterial sheet can be obtained with a high yield. Moreover, it turns out that the antibacterial performance of the obtained antibacterial sheet is high. On the other hand, in the comparative example, a large amount of coarse material was generated in the aqueous coating solution composed of the undissolved antibacterial agent, and due to this, clogging of the spray nozzle and strainer was observed. In addition, the yield is low due to that, and the antibacterial performance of the obtained antibacterial sheet is low. In Comparative Example 2 using the internal addition method, white paper foaming occurred during wet paper making, and paper making troubles occurred. Moreover, it turns out that a yield becomes very low and is not suitable for industrial manufacture.

DESCRIPTION OF SYMBOLS 10 Stock solution tank 11 Stirring blade 12 Dilution tank 13 Stirring blade 14 Strainer 15 Pump 16 Spray nozzle 20 Fiber sheet 21 Conveying belt 22 Yankee dryer 23 Touch roll 24 Antibacterial sheet 25 Doctor blade

Claims (15)

Antibacterial having a step of spraying an aqueous coating solution containing a poorly water-soluble antibacterial agent and a basic compound represented by the following formula (1) and having a pH of 6.5 or more onto a fiber sheet containing cellulose fibers. Manufacturing method of adhesive sheet.

It is an antimicrobial sheet manufacturing method according to claim 1, wherein the anionic active group containing an alkyl group or an alkenyl group of straight or branched chain having 6 to 20 carbon atoms ^- X in the formula (1). It is an antimicrobial sheet manufacturing method according to claim 1 or 2 alkyl phosphates represented by the following formula (2) ^- X in the formula (1).

  The method for producing an antibacterial sheet according to any one of claims 1 to 3, wherein the concentration of the poorly water-soluble antibacterial agent in the aqueous coating solution is 0.2% by mass or more and 3% by mass or less.   The method for producing an antibacterial sheet according to any one of claims 1 to 4, wherein the aqueous coating solution has a pH of 9.0 or less.   The method for producing an antibacterial sheet according to any one of claims 1 to 5, wherein the basic compound is a carbonate.   The method for producing an antibacterial sheet according to any one of claims 1 to 6, wherein the aqueous coating solution further contains a chelating agent.   The method for producing an antibacterial sheet according to any one of claims 1 to 7, wherein the aqueous coating solution further contains ethylenediaminetetraacetic acid or a salt thereof.   The method for producing an antibacterial sheet according to any one of claims 1 to 8, wherein the aqueous coating liquid is sprayed only on the first surface of the fiber sheet having the first surface and the second surface located on the opposite side. .   The antibacterial sheet which has the 1st surface and the 2nd surface located on the opposite side, and was manufactured by the manufacturing method as described in any one of Claim 1 thru | or 9. Antibacterial sheet according to the sparingly water-soluble antimicrobial agent in claim 10 comprising 1 mg / m ² or more.   The antibacterial sheet according to claim 10 or 11, wherein more of the poorly water-soluble antibacterial agent is present on the first surface side than on the second surface.   An absorbent article comprising the antibacterial sheet according to any one of claims 10 to 12.   The absorbent article of Claim 13 arrange | positioned so that the 1st surface in the said antibacterial sheet may oppose a wearer's skin.   The absorbent article according to claim 13 or 14, wherein the absorbent article has a liquid-retaining absorbent core, and a surface of the absorbent core facing the wearer's skin is covered with the antibacterial sheet.

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