JP7624892B2 - Antibacterial paper and its manufacturing method - Google Patents

Description

The present invention relates to antibacterial paper and a method for producing the same.

Antibacterial paper that has been given antibacterial properties is known. For example, Patent Document 1 describes paper to which an inorganic antibacterial agent such as antibacterial zeolite is added externally, and Patent Document 2 describes paper to which an antibacterial agent is added internally. Furthermore, Patent Document 3 proposes the production of antibacterial paper using an aqueous solution of chlorhexidine gluconate.

Japanese Patent Application Publication No. 09-003799 Japanese Patent Application Publication No. 09-003800 JP 2009-242299 A

Generally, a binder such as starch is applied to the surface of paper to improve the sizing, printing properties, and surface strength of the paper. The present inventors have investigated the external coating of an antibacterial agent to impart antibacterial properties to the paper, and have found that when an antibacterial agent is mixed into a coating solution containing additives such as a fluorescent dye, thickening and aggregation occur depending on the combination of the fluorescent dye and the antibacterial agent contained in the coating solution, making it difficult to produce antibacterial paper by external coating.

In view of this situation, the objective of the present invention is to provide a technology for producing excellent antibacterial paper by coating it with an antibacterial agent.

After extensive research into the above-mentioned problems, the inventors discovered that the use of a specific antibacterial agent provides good compatibility with the fluorescent dye, preventing aggregation or precipitation of the coating solution, and enabling the production of excellent antibacterial paper.

The present invention includes, but is not limited to, the following inventions.
[1] A method for producing antibacterial paper, comprising applying a nonionic antibacterial agent and/or a zwitterionic antibacterial agent and a fluorescent dye to a base paper.
[2] The method according to [1], wherein a coating solution containing the antibacterial agent and the fluorescent dye is applied to a base paper.
[3] The method according to [1] or [2], wherein the antibacterial agent comprises a surfactant.
[4] The method according to any one of [1] to [3], wherein the fluorescent dye is anionic.
[5] An antibacterial paper having a layer containing a nonionic antibacterial agent and/or a zwitterionic antibacterial agent and a fluorescent dye on a base paper.
[6] The antibacterial paper according to [5], wherein the layer containing the antibacterial agent and the fluorescent dye is a clear coating layer containing starch.
[7] The antibacterial paper according to [6], wherein the clear coating layer contains NaCl.
[8] The antibacterial paper according to any one of [5] to [7], which is a wood-free paper having no pigment coating layer.
[9] The antibacterial paper according to any one of [5] to [8], wherein the fluorescent dye is anionic.

The present invention provides excellent antibacterial paper and a method for producing the same. Furthermore, the antibacterial paper produced by the present invention has a significantly improved fluorescence intensity due to the combined use of a fluorescent dye and a specific antibacterial agent, and a synergistic effect has been confirmed by the combined use of a specific antibacterial agent and a fluorescent dye.

The present invention relates to antibacterial paper having an antibacterial layer on a base paper. The antibacterial paper according to the present invention has an antibacterial layer on the base paper that contains a nonionic antibacterial agent and/or a zwitterionic antibacterial agent and a fluorescent dye, and is obtained by applying a surface treatment liquid (coating liquid) on the base paper.

The antibacterial paper of the present invention has antibacterial properties, and has an antibacterial activity value of about 3.0 or more as measured based on the antibacterial test method of JIS L1902. However, since the antibacterial test measures the extent to which bacterial growth can be suppressed, if the sample has bacteriostatic (germicidal) properties to begin with, the inoculated bacteria may not grow and the antibacterial activity value may be low. Therefore, in the present invention, antibacterial properties are considered to be present even if the number of live bacteria immediately after inoculation in the antibacterial test is less than 20.

In the present invention, a layer containing an antibacterial agent and a fluorescent dye is provided on the base paper, and the amount of coating can be adjusted, for example, by adjusting the viscosity of the surface treatment solution or the coating speed. That is, by lowering the viscosity using a surfactant or the like, it is possible to make the coating solution more likely to penetrate into the paper, or by coating at high speed, it is possible to make the coating solution remain on the paper surface. In one embodiment of the present invention, polysaccharides such as starch are applied to the surface of the paper to improve not only the surface strength of the paper but also its stiffness, and the polysaccharides can also penetrate appropriately into the paper layers to improve interlayer strength.

The antibacterial paper obtained by the present invention can be used as it is for various purposes as a product without any restrictions, for example, printing paper, writing paper, book paper, newsprint, packaging paper, tissue paper, base paper for pigment coated paper, various information recording papers such as inkjet recording, thermal recording, carbonless copying, form paper, copy paper, and base paper for these. Considering the use as printing paper, the gloss after printing of the antibacterial paper of the present invention is preferably 40% or more, more preferably 50% or more, and even more preferably 60% or more. In a 10-point scale, 4 or more is good, and 7 or more is particularly good. In addition, from the viewpoint of suppressing troubles during printing, the interlayer strength in the MD direction is preferably 90 gf/15 mm or more, more preferably 100 gf/15 mm or more, and even more preferably 110 gf/15 mm or more.

The basis weight of the antibacterial paper according to the present invention is not particularly limited, but can be, for example, 25 to 500 g/m ² , 35 to 300 g/m ² , or 40 to 250 g/m ^2. In other embodiments, the basis weight of the antibacterial paper can be, for example, 45 to 100 g/m ² , 50 to 90 g/m ² , or 55 to 80 g/m ² .

The antibacterial paper of the present invention preferably has a relative air permeability of 1.4 or more, more preferably 3.0 or more or 5.0 or more. The antibacterial paper of the present invention also preferably has a breaking length in the CD direction of 3.0 km or more, more preferably 4.0 km or more or 4.5 km or more. If the relative air permeability or breaking length is too low, there is a risk of the paper tearing during the production of the antibacterial paper.

The ash content of the antibacterial paper of the present invention can be set as appropriate, but for example, can be from 0.1% to 40% by weight, and preferably from 5% to 30% by weight. If the ash content in the paper is higher than 30% by weight, the filler in the paper may inhibit the bonding between the fibers, resulting in a risk of the paper lacking in stiffness and strength. The ash content in the paper is measured in accordance with JIS-P8252.

In one embodiment, the antibacterial paper according to the present invention is an uncoated paper having no pigment coating layer, and may be an uncoated wood-free paper.
Base paper
The base paper used in the present invention comprises a pulp raw material. There is no particular restriction on the pulp raw material used, and in addition to wood pulp, bamboo pulp, linter pulp, non-wood pulp such as hemp, bagasse, kenaf, esparto grass, straw, etc., semi-synthetic fibers such as rayon and acetate, synthetic fibers such as polyolefin, polyamide, polyester, etc. can be used. Specifically, those generally used as raw materials for papermaking, such as mechanical pulp (MP), deinked pulp (DIP, also called waste paper pulp), hardwood kraft pulp (LKP), softwood kraft pulp (NKP), etc., can be suitably used, and one or more of these can be used in combination as appropriate. These pulps may be unbleached pulps that are not bleached, or bleached pulps that are bleached by one or several means. Examples of mechanical pulp include groundwood pulp (GP), refiner groundwood pulp (RGP), thermomechanical pulp (TMP), chemi-thermomechanical pulp (CTMP), chemi-ground pulp (CGP), and semi-chemical pulp (SCP). There are no particular limitations on the deinked pulp, so long as it is made from sorted waste paper such as fine paper, medium-quality paper, low-quality paper, newspapers, flyers, and magazines, or unsorted waste paper in which these are mixed, or office waste paper including copy paper, thermal paper, and carbonless paper, confidential waste paper, and paper cups. Cellulose nanofibers, cellulose nanofibrils, microfibril cellulose, microcrystalline cellulose, cellulose powder, and the like can also be used. There are no particular limitations on the base paper used in the present invention, and examples of the base paper that can be used include copy paper, newsprint, medium-quality paper, liner, and core base paper. In one embodiment, the base paper according to the present invention is fine paper, and only chemical pulp is used as the pulp for the base paper.

Various internal additives may be added to the base paper used in the present invention as long as they do not impair the effects of the present invention. Examples of the internal additive chemicals include, but are not limited to, inorganic chemicals such as aluminum sulfate (aluminum sulfate), polyaluminum chloride, sulfuric acid, hydrochloric acid, sodium hydroxide, and sodium hydrogen carbonate; organic chemicals such as polyacrylamide polymers, polyvinyl alcohol polymers, oxidized starch, esterified starch, cationized starch, various modified starches, styrene-butadiene copolymers, latex, and vinyl acetate adhesives; cellulose derivatives such as carboxymethyl cellulose and hydroxyethyl cellulose; internal paper strength enhancers such as urea-formalin resin and melamine-formalin resin; internal sizing agents such as rosin-based sizing agents, AKD-based sizing agents, ASA-based sizing agents, petroleum-based sizing agents, and neutral rosin sizing agents; aluminum sulfate, retention improvers, retention aids, ultraviolet inhibitors, color-fading inhibitors, drainage improvers, coagulants, bulking agents, pH adjusters, slime control agents, colorants (dyes, pigments), and fluorescent dyes such as coumarin derivatives, pyrazoline derivatives, stilbene derivatives, and azole derivatives. Additionally, various cellulose nanofibers and fine fiber cellulose may be used as internal additives.

The base paper used in the present invention can be filled with commonly used fillers, for example, one or more inorganic or organic fillers. Examples of inorganic fillers include heavy calcium carbonate, light calcium carbonate, calcium sulfite, gypsum, talc, kaolin, engineered kaolin, calcined kaolin, white carbon, amorphous silica, delaminated kaolin, diatomaceous earth, magnesium carbonate, titanium dioxide, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide, papermaking sludge, and recycled inorganic particles from deinking floss. Examples of organic fillers include urea-formaldehyde resin, vinyl chloride resin, polystyrene resin, urea/formaldehyde resin, melamine resin, styrene/butadiene copolymer resin, phenolic resin, and hollow plastic particles.

The base paper of the present invention can be made by a known method. For example, the above-mentioned raw materials are mixed and diluted appropriately, and foreign matter is removed using a screen or cleaner as necessary. The diluted paper is then sprayed onto a papermaking wire from the head box of a papermaking machine to form a wet paper. The base paper of the present invention can be made using various papermaking machines, such as a fourdrinier type, a cylinder type, a cylinder multi-cylinder type, a short wire type, or a twin-wire type papermaking machine. Examples of twin-wire papermaking machines include a gap former and an on-top former. In addition, the base paper may be made using a crescent former type or a Yankee dryer type papermaking machine. The conditions in the pressing process and drying process after papermaking can be adjusted as appropriate.

The conditions for making the base paper may be neutral or acidic. Specifically, in the present invention, the pH of the stock during papermaking is preferably 3.0 to 9.0, and more preferably 4.0 to 8.0.

Coating (painting)
In the present invention, in order to impart antibacterial properties, a layer (antibacterial layer) containing at least a nonionic antibacterial agent and/or a zwitterionic antibacterial agent and a fluorescent dye is provided on the base paper. In the present invention, the coating amount (coating amount) of the antibacterial layer is not particularly limited, but can be, for example, in the range of 0.1 to 10 g/ ^m2 on both sides, preferably 0.5 to 6.0 g/ ^m2 , and more preferably 1.0 to 3.0 g/ ^m2 . If the coating amount is too large, the absolute amount of moisture increases, which increases the drying load and may make drying defects more likely to occur.

(Antibacterial Agent)
In the present invention, an antibacterial agent is applied onto the base paper, and a nonionic antibacterial agent and/or a zwitterionic antibacterial agent is used as the antibacterial agent. The nonionic antibacterial agent and/or the zwitterionic antibacterial agent may be used alone or in combination of two or more antibacterial agents. In the present invention, the antibacterial agent means an agent that can impart antibacterial properties, and commercially available antibacterial agents, bactericides, disinfectants, etc. can be used. For example, an agent having not only antibacterial properties but also antiviral properties can be used as the antibacterial agent.

Preferred antibacterial agents include surfactant-based antibacterial agents, and examples of nonionic surfactant antibacterial agents include glycerol fatty acid esters and polyoxyethylene alkyl ethers, and examples of zwitterionic surfactant antibacterial agents include alkyldiaminoethylglycine chloride and alkylpolyaminoethylglycine. Commercially available surfactant-based antibacterial agents include, for example, Anhithol 20N, Emulgen 106, Amolden V-500HP, Poem M-200, Poem DL-100, Mydol 10, Mydol 12, Air heal, Tego 51 (registered trademark), and LAG (registered trademark).

In the present invention, organic antibacterial agents and inorganic antibacterial agents can be used within the scope of the present invention, and hybrid antibacterial agents of organic and inorganic antibacterial agents can also be used.

Examples of organic antibacterial agents include ethylene oxide, glutaraldehyde, orthophthalaldehyde, cresol, chitosan, hinokitiol, mustard extract, iodine-based agents such as povidone-iodine, biguanide-based agents such as chlorhexidine, dye-based agents such as acrinol, polyphenol-based agents, benzimidazole-based agents, phthalimide-based agents, isothisolone-based agents, pyridine-based agents, and nitrile-based antibacterial agents.

As inorganic antibacterial agents, for example, silver-based antibacterial agents, copper-based antibacterial agents, or zinc-based antibacterial agents can be used, and silver-based antibacterial agents are preferred from the viewpoint of safety, etc. As silver-based antibacterial agents, there are no particular limitations as long as they are inorganic compounds carrying silver ions, and specific examples thereof include inorganic adsorbents such as activated carbon, activated alumina, and silica gel, and inorganic ion exchangers such as zeolite, hydroxyapatite, zirconium phosphate, titanium phosphate, and potassium titanate. As copper-based antibacterial agents, there are no particular limitations as long as they are inorganic compounds carrying copper ions, and specific examples thereof include inorganic adsorbents such as activated carbon, activated alumina, and silica gel, and inorganic ion exchangers such as zeolite, hydroxyapatite, zirconium phosphate, titanium phosphate, and potassium titanate. As zinc-based antibacterial agents, there are no particular limitations as long as they are inorganic compounds carrying zinc ions, and specific examples thereof include inorganic adsorbents such as activated carbon, activated alumina, and silica gel, and inorganic ion exchangers such as zeolite, hydroxyapatite, zirconium phosphate, titanium phosphate, and potassium titanate. When using a zeolite-based antibacterial agent, antibacterial zeolite obtained by replacing a portion of the ion-exchangeable metals in zeolite with at least one metal selected from silver, copper, and zinc is preferably used.

Commercially available inorganic antibacterial agents include, for example, Silver Bread, Cozy Pack Air, AG Alpha (registered trademark) CF-01, AG Alpha (registered trademark) CF-04, Novalon, Kesmon, Allerimub, MP-102SVC13, Silver Ace, Zeomic, Lock-3, and Ion Pure.

(Fluorescent dye)
In the present invention, the above antibacterial agent and a fluorescent dye are used in combination. In the present invention, various fluorescent dyes can be used, such as 4,4'-diaminostilbene-2,2'-disulfonic acid derivatives, 4,4-bis{2-sodiumsulfanyl-4-di(hydroxyethyl)amino-1,3,5-triazinyl-(6)-amino}stilbene-2,2-disulfonic acid sodium, umbelliferone, 4,4'-bis(2-sulfonatostyryl)biphenyl disodium, 4'-(2-cyanostyryl)-4-stilbenecarbonitrile, 4,4'-bis(2-benzoxazolyl)stilbene, 1,2-bis(5-methylbenzoxazol-2-yl)ethene, Examples of fluorescent dyes include acenaphthylene, 1,4-bis(2-benzoxazolyl)naphthalene, 4,4'-stilbenedicarboxylic acid, 4,4'-bis(5-methyl-2-benzoxazolyl)stilbene, 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene, o-(chloromethyl)benzonitrile, 4,4'-bis(diethylphosphonomethyl)biphenyl, 2,5-thiophenedicarboxylic acid, 4-tert-butyl-2-nitrophenol, 2,5-bis(benzoxazol-2-yl)thiophene, and benzoxazole derivatives, and anionic fluorescent dyes are preferred. When using a fluorescent dye, the solids concentration in the surface treatment solution is preferably 0.01 to 5.0% by weight, more preferably 0.03 to 1.5% by weight.

The weight ratio of antibacterial agent to fluorescent dye can be, for example, 0.1-1000, preferably 1-100, or may be 2-80 or 3-60.
(glue)
In the present invention, a surface coating liquid containing a polysaccharide such as starch as an adhesive (binder) can be applied to the base paper, thereby imparting surface strength, water resistance, printability, and the like to the paper.

Adhesives containing polysaccharides include, but are not limited to, starch, cellulose, chitin, glycogen, agarose, pectin, etc. As for starch, for example, corn starch, tapioca starch, potato starch, wheat starch, rice starch, etc. can be suitably used.

When the antibacterial agent and adhesive are applied together, the solids weight ratio of the antibacterial agent to the adhesive can be, for example, 2:1 to 1:200, preferably 1:1 to 1:150, and may be 1:2 to 1:100 or 1:3 to 1:50.

In addition, in the present invention, starch that has been modified by various known methods may be used. Modification methods include, for example, enzyme modification using α-amylase, esterification, cationization, acetylation, aldehyde conversion, hydroxyethylation, and other treatments. Esterification includes acetate esterification and phosphate esterification, and etherification includes carboxy etherification and hydroxy etherification. In order to highly demonstrate the retrogradation stability improving effect of the present invention, it is preferable to use self-modified starch that has been modified in a paper mill to reduce its viscosity using acetylated tapioca starch as a raw material, in particular APS-modified starch that has been thermochemically modified by adding ammonium persulfate (APS) as an oxidizing agent, or enzyme-modified starch that has been hydrolyzed using α-amylase. Self-modified starch that is modified in a paper mill allows easy adjustment of the viscosity at the manufacturing site and is also advantageous in terms of cost.

The adhesive used for the surface treatment is not particularly limited as long as it contains at least a polysaccharide, but in addition to starch, for example, cellulose derivatives such as carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, cellulose nanofiber, fine fiber cellulose, guar gum, xanthan gum, gum arabic, dextrin, alginic acid, hyaluronic acid, xylan, glucomannan, carrageenan, polyacrylamide, polyvinyl alcohol, carboxyl-modified polyvinyl alcohol, acetoacetylated polyvinyl alcohol, and other modified alcohols, latex, styrene-butadiene copolymers, polyvinyl acetate, vinyl chloride-vinyl acetate copolymers, polyvinyl chloride, polyvinylidene chloride, polyacrylic acid esters, and the like may be used alone or in combination. In the present invention, it is preferable that the proportion of polysaccharides such as starch in the adhesive in the antibacterial layer is 50% or more. More preferably, it is 80% or more. If it is less than 50%, the viscosity of the surface treatment solution decreases, which may cause problems such as deterioration in strength and stiffness, and the cost will also increase.

Furthermore, the surface treatment liquid (coating liquid) of the present invention may contain various auxiliary agents, such as salts such as sodium chloride, dispersants, thickeners, water retention agents, defoamers, water resistance agents, colorants, and conductive agents, as necessary.

The device (coater) for applying the surface treatment liquid is not particularly limited, and known devices can be used. As the coater, a pond type size press, a film transfer type gate roll coater or a lot metering size press, as well as a blade coater, a spray coater, a curtain coater, etc. can be used. In addition, so-called calendar sizing can be performed in which application is performed using an applicator or spray in a calendar or super calendar. Furthermore, the coating liquid can be sprayed and applied in front of the Yankee dryer.

In the present invention, other layers may be provided in addition to the layer containing the antibacterial agent, i.e., for example, a clear coating layer or a pigment coating layer may be provided in addition to the layer containing the polysaccharide and the antibacterial agent.
After the clear coating layer is applied to the base paper, the paper may be passed through a known finishing device, such as a supercalender, gloss calender, soft calender, or high-temperature soft nip calender, to perform product finishing, or may be left untreated or may be bypassed.

The present invention will be illustrated below with specific examples, but it is not intended that the present invention be limited to the following examples. In this specification, unless otherwise specified, "parts" and "%" are by weight, and numerical ranges are stated to include their endpoints.

Experiment 1. Confirmation of compatibility Antimicrobial agents with different ionic properties were mixed with a fluorescent dye to confirm the compatibility of the two. Specifically, 5 ml of the undiluted fluorescent dye and 5 ml of the antimicrobial agent diluted to 5% were mixed in a 20 ml vial, and the vial was then capped and vigorously shaken by hand for 30 seconds.
(Antibacterial Agent)
・Cationic surfactant (Sanisol B-50, Kao, solids concentration: 50%)
・Anionic surfactant (Neopelex G-15, Kao, solids concentration: 16%)
・Ampholytic surfactant (Amphitol 20N, Kao, solids concentration: 35%)
・Nonionic surfactant (Emulgen 106, Kao, solids concentration: 94%)
(Fluorescent dye)
Fluorescent dye A (Blancofer Z-NSP, Bayer, anionic, concentration: 55%)
Fluorescent dye B (Sun White BUL-TC, Sunrise Chemical anionic, concentration: 67%)
After shaking, the mixture was allowed to stand for 24 hours, and the compatibility was evaluated visually based on the following criteria.
(Evaluation Criteria for Compatibility)
○ (Good): Clear or uniformly dispersed state is maintained. × (Bad): Precipitation or aggregation occurs, resulting in a paste or gel-like state.

When cationic antibacterial agents were mixed with fluorescent dyes, gel-like white aggregates were formed. When anionic antibacterial agents were mixed with fluorescent dyes, white aggregates and precipitation occurred. On the other hand, when nonionic or zwitterionic antibacterial agents were mixed with fluorescent dyes, the properties of the mixture were good even 24 hours after mixing.

Experiment 2. Production and evaluation of antibacterial paper (1) Production of antibacterial paper 200 g of coating solution was prepared by mixing the raw materials in the following ratio. Specifically, in a 500 mL container, water (ion-exchanged water) with a liquid temperature of 40° C. was mixed with the raw materials, and the mixture was stirred with a spatula for 3 minutes to prepare the coating solution.

Next, each coating liquid was applied using a wire bar to one side of a base paper for fine paper (basis weight: approximately 60 g/ ^m2 , neutral paper) that had neither pigment coating nor clear coating, and the paper was then air-dried overnight to produce fine paper.
(2) Evaluation of antibacterial paper The coated surface of the prepared fine paper was evaluated as follows. When evaluating, the paper was left to stand overnight in a constant temperature and humidity room (25° C., relative humidity: 50%) to adjust the humidity.
(a) Antibacterial activity
Based on the antibacterial test method of JIS L1902, a 2.8cm x 2.8cm wood-free paper sample was used as the test piece. 0.2mL of a test solution containing Staphylococcus aureus (test bacteria concentration: ^1.0x105 to ^3.0x105 CFU/mL) was inoculated onto the surface of the test piece, and then the test piece was cultured at 37°C for 18 to 24 hours. Immediately after the inoculation and after the culture, 20mL of washout solution was added to wash out the test bacteria from the test piece, the viable bacteria count in the washout solution was measured, and the antibacterial activity value (A) was calculated by the following formula. Washed cotton cloth (cotton No. 3-1) was used as a control sample (JIS L0803).

(b) Opacity Using a whiteness spectrophotometer (CMS-35SPX), the opacity of a sample was measured by stacking a number of sheets so that no bleed-through occurred. A light trap was also set up and a single sample was sandwiched between the sheets, and the measurement was performed in the same manner. The opacity was calculated from the measured value of UV-in "Y" based on the following formula.

Opacity (%) = UV-in Y (one sample) ÷ UV-in Y (multiple samples)
(c) ISO Whiteness: Measured using a whiteness spectrophotometer (CMS-35SPX). Whiteness was evaluated using the UV-in ISO-B value.
(d) Color Tone The color tone was measured using a whiteness spectrophotometer (CMS-35SPX) (C light source, 2° field of view). The color tone was evaluated using the UV-cut L*, a*, and b* values.
(e) Fluorescence intensity was measured using a whiteness spectrophotometer (CMS-35SPX). Fluorescence intensity was evaluated using the UV-cut F1 value.

The coating solution containing a cationic or anionic antibacterial agent and a fluorescent dye caused aggregation or precipitation (samples A3-A4, B3-B4). When the coating solution causing aggregation or precipitation was applied with a wire bar, it was possible to impart antibacterial activity to the fine paper, but it was not possible to improve the fluorescence intensity as in the examples of the present invention (samples A5-A6, B5-B6).

On the other hand, when a coating solution containing a zwitterionic or nonionic antibacterial agent and a fluorescent dye was used based on the present invention, the coating solution did not aggregate or precipitate, and the coating solution could be applied smoothly (samples A5-A6, B5-B6).

In addition, when the fluorescent dye and antibacterial agent were used in combination according to the present invention, the fluorescent intensity of the fine paper was significantly improved, and it was believed that a synergistic effect was produced by the combined use of the fluorescent dye and antibacterial agent. Furthermore, according to the present invention, the L ^* value was increased, the b ^* value was decreased, and antibacterial paper with higher whiteness and less dullness was obtained.

Claims (9)

A method for producing antimicrobial paper, comprising applying a nonionic and/or zwitterionic antimicrobial agent and an anionic fluorescent dye to a base paper. The method of claim 1, in which a coating solution containing the antibacterial agent and the fluorescent dye is applied to the base paper. The method of claim 1 or 2, wherein the antimicrobial agent comprises a zwitterionic surfactant. The method according to any one of claims 1 to 3, wherein the weight ratio of the antibacterial agent to the fluorescent dye (antibacterial agent/fluorescent dye) is 0.1 to 1000 . An antibacterial paper having a layer containing a nonionic antibacterial agent and/or a zwitterionic antibacterial agent and an anionic fluorescent dye on a base paper. An antibacterial paper according to claim 5, wherein the layer containing the antibacterial agent and the fluorescent dye is a clear coating layer containing starch. The antibacterial paper according to claim 6, wherein the clear coating layer contains NaCl. An antibacterial paper according to any one of claims 5 to 7, which is a wood-free paper that does not have a pigment coating layer. The antibacterial paper according to any one of claims 5 to 8, wherein the layer containing the antibacterial agent and the fluorescent dye contains an adhesive, and the solids weight ratio of the antibacterial agent to the adhesive is from 2:1 to 1:200 .