JP2022191568A - Antibacterial paper and manufacturing method thereof - Google Patents

Abstract

To provide excellent antibacterial paper and a manufacturing method thereof.SOLUTION: Antibacterial paper is provided that has a layer involving an anionic antibacterial agent and/or an amphoteric ionic antibacterial agent and a size agent on base paper.SELECTED DRAWING: None

Description

ANTIBACTERIAL PAPER AND METHOD FOR MANUFACTURE THEREOF TECHNICAL FIELD The present invention relates to an antibacterial paper and a method for producing the same.

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

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

In general, a binder such as starch is applied to the surface of paper to improve its sizing properties, printing properties, surface strength, and the like. The inventors of the present invention have studied the external coating of an antibacterial agent on paper in order to impart antibacterial properties to paper. It was found that depending on the combination of the sizing agent and the antibacterial agent contained in the paper, thickening and aggregation may occur, making it difficult to produce antibacterial paper by external coating.

In view of such circumstances, an object of the present invention is to provide a technique for producing excellent antibacterial paper by applying an antibacterial agent.

The present invention includes, but is not limited to, the following inventions.
[1] A method for producing antibacterial paper, comprising applying an anionic antibacterial agent and/or a zwitterionic antibacterial agent and a surface sizing agent to a base paper.
[2] The method according to [1], wherein a coating liquid containing the antibacterial agent and the surface sizing agent is applied to the base paper.
[3] The method according to [1] or [2], wherein the antibacterial agent contains a surfactant.
[4] The method according to any one of [1] to [3], wherein the surface sizing agent contains an anionic surface sizing agent or an alkylketene dimer.
[5] An antibacterial paper having a layer containing an anionic antibacterial agent and/or a zwitterionic antibacterial agent and a surface sizing agent on the base paper.
[6] The antibacterial paper according to [5], wherein the layer containing the antibacterial agent and the surface sizing agent is a clear coating layer containing starch.
[7] The antibacterial paper according to [5] or [6], which is woodfree paper without a pigment coating layer.
[8] The antibacterial paper according to any one of [5] to [7], wherein the surface sizing agent contains an anionic surface sizing agent or an alkylketene dimer.

ADVANTAGE OF THE INVENTION According to this invention, the excellent antibacterial paper and its manufacturing method are provided.

TECHNICAL FIELD The present invention relates to an antibacterial paper in which an antibacterial layer is provided on base paper. The antibacterial paper according to the present invention has an antibacterial layer containing an anionic antibacterial agent and/or a zwitterionic antibacterial agent and a surface sizing agent on the base paper, and a surface treatment liquid (coating liquid) is applied on the base paper. obtained by

The antibacterial paper according to the present invention has antibacterial properties, and has an antibacterial activity value of about 3.0 or more as measured according to the antibacterial test method of JIS L1902. However, since the antibacterial test is about how much the growth of bacteria can be suppressed, if the sample has bacteriostatic (bactericidal) properties in the first place, the inoculated bacteria will not grow and the antibacterial activity value will be low. Therefore, in the present invention, even if the number of viable bacteria immediately after inoculation in the antibacterial test is less than 20, it is assumed to have antibacterial properties.

In the present invention, a layer containing an antibacterial agent and a surface sizing agent is provided on the base paper. can be adjusted. That is, it is possible to make it easier for the coating liquid to penetrate into the inside of the paper by lowering the viscosity using a surfactant or the like, or to make the coating liquid stay on the paper surface by applying it at high speed. . In one embodiment of the present invention, by applying a polysaccharide such as starch to the surface of the paper, not only the surface strength but also the stiffness of the paper is improved, and the polysaccharide moderately penetrates into the paper layer. By doing so, it is possible to improve the interlaminar strength.

The antibacterial paper obtained in the present invention can be used as it is as a product in various applications without limitation. , ink-jet recording, heat-sensitive recording, carbonless copying, and other various information recording papers, and their base papers. Considering the use as printing paper, the post-printing glossiness of the antibacterial paper according to the present invention is preferably 40% or more, more preferably 50% or more, and even more preferably 60% or more. On a scale of 10, 4 or more is good, and 7 or more is particularly good. 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, 25-500 g/m ² , 35-300 g/m ² , 40-250. In another aspect, the basis weight of the antibacterial paper may be, for example, 45-100 g/m ² , 50-90 g/m ² or 55-80 g/m ² .

The antibacterial paper according to 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. Moreover, the antibacterial paper according to the present invention 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 and breaking length are too low, paper breakage may occur in the production of the antibacterial paper.

The ash content in the paper of the antibacterial paper according to the present invention can be appropriately set, but can be, for example, 0.1% by weight or more and 40% by weight or less, preferably 5% by weight or more and 30% by weight or less. If the ash content in the paper is higher than 30% by weight, the filler in the paper inhibits the bonding between the fibers, possibly resulting in insufficient stiffness and strength of the paper. The ash content in paper is measured according to JIS-P8252.

In one embodiment, the antimicrobial paper according to the present invention is uncoated paper that does not have a pigment coating layer, and may be uncoated woodfree paper.
Base paper
The base paper used in the present invention comprises a pulp raw material. There are no particular restrictions on the pulp raw materials used, and in addition to wood pulp, non-wood pulp such as bamboo pulp, linter pulp, hemp, bagasse, kenaf, esparto grass, and straw, semi-synthetic fibers such as rayon and acetate, polyolefin, and polyamide. , synthetic fibers such as polyester can be used. Specifically, mechanical pulp (MP), deinked pulp (DIP, also called waste paper pulp), hardwood kraft pulp (LKP), softwood kraft pulp (NKP), etc. are commonly used as raw materials for papermaking. can be suitably used, and one or two or more of these may be blended and used as appropriate. These pulps may be unbleached pulps that have not been bleached, or bleached pulps that have been bleached by one or several means. Mechanical pulps include groundwood pulp (GP), refiner groundwood pulp (RGP), thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP), chemi-ground pulp (CGP), semi-chemical pulp (SCP), and the like. . As deinked pulp, office paper including fine paper, medium quality paper, low-grade paper, sorted waste paper such as newspaper, leaflet, magazine, unsorted waste paper mixed with these, copy paper, thermal paper, carbonless paper, etc. There is no particular limitation as long as it is deinked pulp made from waste paper, classified waste paper, paper cups, or the like. Cellulose nanofibers, cellulose nanofibrils, microfibril cellulose, microcrystalline cellulose, cellulose powder, and the like can also be used. The base paper used in the present invention is not particularly limited, but for example, copy paper, newsprint, medium-quality paper, liner, core base paper, etc. can be used. Only chemical pulps are used as base paper pulps.

Various internal additives may be added to the base paper used in the present invention as long as the effects of the present invention are not impaired. Examples of internal additives 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, and organic chemicals such as polyacrylamide. adhesives such as polymer, polyvinyl alcohol polymer, oxidized starch, esterified starch, cationized starch, other various modified starches, styrene-butadiene copolymer, latex, vinyl acetate; cellulose such as carboxymethyl cellulose and hydroxyethyl cellulose Derivatives; internal paper strength enhancers such as urea/formalin resins and melamine/formalin resins; 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 Agent; aluminum sulfate, retention aid, retention aid, UV inhibitor, anti-fading agent, drainage improver, coagulant, bulking agent, pH adjuster, slime control agent, colorant (dye, pigment) and A fluorescent dye or the like may be added. Furthermore, 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 fillers or organic fillers can be used. 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, and magnesium carbonate. , titanium dioxide, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide, papermaking sludge, recycled inorganic particles from deinked floss, etc. Examples of organic fillers include urea formalin resin, vinyl chloride Resins, polystyrene resins, urea/formalin resins, melamine resins, styrene/butadiene copolymer resins, phenolic resins, hollow plastic particles, and the like.

The base paper in the present invention can be made by a known method. For example, the paper material mixed with the above raw materials is appropriately diluted, and if necessary, foreign substances are removed with a screen or a cleaner, and then the mixture is jetted from the headbox of the paper machine onto the papermaking wire to form a wet paper web. The base paper of the present invention can be produced by various paper machines such as fourdrinier, cylinder, cylinder and multi-cylinder, short mesh and twin wire machines. Twin wire paper machines include gap formers, on-top formers, and the like. Alternatively, the base paper may be produced using a Crescent former type or Yankee dryer type paper machine. The conditions in the press process and the drying process after papermaking can be appropriately adjusted.

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

coating (coating)
In the present invention, a layer (antibacterial layer) containing at least an anionic antibacterial agent and/or a zwitterionic antibacterial agent and a sizing agent is provided on the base paper in order to impart antibacterial properties. ^In the present invention, the coating amount ⁽ coating amount) of the antibacterial layer is not particularly limited. Preferably, 1.0 to 3.0 g/m ² is more preferable. If the coating amount is too large, the absolute amount of moisture increases, which increases the drying load and may cause poor drying.

(Antibacterial agent)
In the present invention, the base paper is coated with an antibacterial agent, and an anionic antibacterial agent and/or a zwitterionic antibacterial agent is used as the antibacterial agent. As for the anionic antibacterial agent and/or the zwitterionic antibacterial agent, only one antibacterial agent may be used, or two or more antibacterial agents may be used in combination. In the present invention, an antibacterial agent means an agent that can impart antibacterial properties, and commercially available antibacterial agents, disinfectants, disinfectants, etc. can be used. For example, it has not only antibacterial properties but also antiviral properties. Drugs can also be used as antimicrobial agents.

Preferred antibacterial agents include surfactant-based antibacterial agents. For example, anionic surfactant antibacterial agents include sodium linear alkylbenzene sulfonate, and zwitterionic surfactant antibacterial agents include: Chlorinated alkyldiaminoethylglycine, alkylpolyaminoethylglycine, and the like. Regarding surfactant-based antibacterial agents, commercially available products include, for example, Amphithol 20N, Neoperex G-15, Botanicle (registered trademark), REZOMA, Air Heal, Karaseed, Keisanit (registered trademark), Best Clean Mind, NS Soap. , OS soap, HYP-KK171 and the like.

In the present invention, an organic antibacterial agent or an inorganic antibacterial agent can be used as long as the effects of the present invention are not impaired, and a hybrid type antibacterial agent of an organic antibacterial agent and an inorganic antibacterial agent can be used. can also

Organic antibacterial agents include, for example, ethylene oxide, glutaraldehyde, orthophthalaldehyde, cresol, chitosan, hinokitiol, mustard extract, iodine compounds such as povidone iodine, biguanide compounds such as chlorhexidine, dye compounds such as acrinol, polyphenol compounds, and Examples include benzimidazole-based, phthalimide-based, isotisolone-based, pyridine-based, and nitrile-based antibacterial agents.

As the inorganic antibacterial agent, for example, a silver antibacterial agent, a copper antibacterial agent, a zinc antibacterial agent, or the like can be used, and a silver antibacterial agent is preferable from the viewpoint of safety. The silver-based antibacterial agent is not particularly limited as long as it is an inorganic compound that supports silver ions. Specific examples include inorganic adsorbents such as activated carbon, activated alumina, and silica gel, zeolite, hydroxyapatite, and zirconium phosphate. , titanium phosphate, potassium titanate, and other inorganic ion exchangers. The copper-based antibacterial agent is not particularly limited as long as it is an inorganic compound carrying copper ions. Specifically, inorganic adsorbents such as activated carbon, activated alumina, and silica gel, zeolite, hydroxyapatite, and zirconium phosphate are used. , titanium phosphate, potassium titanate, and other inorganic ion exchangers. The zinc-based antibacterial agent is not particularly limited as long as it is an inorganic compound carrying zinc ions. Specific examples include inorganic adsorbents such as activated carbon, activated alumina, and silica gel, zeolite, hydroxyapatite, and zirconium phosphate. , titanium phosphate, potassium titanate, and other inorganic ion exchangers. When using a zeolite-based antibacterial agent, an antibacterial zeolite obtained by substituting at least one metal selected from silver, copper, and zinc for a portion of the ion-exchangeable metals of the zeolite is preferably used.

Regarding inorganic antibacterial agents, commercially available products include, for example, Silver Bullet, Cozy Pack Air, AG Alpha (registered trademark) CF-01, AG Alpha (registered trademark) CF-04, Novalon, Kesmon, Allele Move, MP-102SVC13 , Silver Ace, Zeomic, Lock-3, and Ion Pure.

(Surface sizing agent)
In the present invention, the above antibacterial agent and surface sizing agent are used in combination. Various sizing agents can be used in the present invention. AKD), alkenyl succinic anhydride (ASA), etc. may be used. When a surface sizing agent is used, the solid concentration in the surface treatment liquid is preferably 0.05 to 5% by weight, more preferably 1 to 3% by weight.

The weight ratio of the antimicrobial agent to the surface sizing agent can be, for example, 99:1 to 1:99, preferably 90:10 to 10:90, 80:20 to 20:80 or 70:30 to 30: 70 may be used.

(glue)
In the present invention, a surface coating solution containing a polysaccharide such as starch as an adhesive (binder) can be applied to the base paper, thereby imparting surface strength, water resistance, printability, etc. to the paper. can.

Adhesives containing polysaccharides include, but are not limited to, starch, cellulose, chitin, glycogen, agarose, pectin, and the like. 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 solid content weight ratio of the antibacterial agent and adhesive can be, for example, 2:1 to 1:200, preferably 1:1 to 1:150, It may be 1:2 to 1:100 or 1:3 to 1:50.

In addition, in the present invention, starch that has undergone various modifications by known methods may be used. Examples of modification methods include enzymatic modification using α-amylase, esterification, cationization, acetylation, aldehyde formation, hydroxyethylation, and the like. Esterification includes treatments such as acetic esterification and phosphate esterification, and etherification may include treatments such as carboxyetherification and hydroxyetherification. In order to highly express the aging stability improvement effect of the present invention, acetylated tapioca starch or the like is used as a raw material, and autologous modified starch is made low in viscosity by modification treatment in a paper mill. It is preferable to use APS-modified starch thermochemically modified by adding ammonium sulfate (APS) or enzyme-modified starch hydrolyzed with α-amylase. Self-modified starch that is modified in a paper mill facilitates adjustment of viscosity at the manufacturing site and is advantageous in terms of cost.

The adhesive used for surface treatment is not particularly limited as long as it contains at least a polysaccharide, but other than starch, for example, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, cellulose derivatives such as cellulose nanofibers, fine fiber cellulose, guar gum, Xanthan gum, gum arabic, dextrin, alginic acid, hyaluronic acid, xylan, glucomannan, carrageenan, polyacrylamide, polyvinyl alcohol, carboxyl-modified polyvinyl alcohol, denatured alcohol such as acetoacetylated polyvinyl alcohol, latex, styrene-butadiene copolymer, Polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, polyacrylic acid ester and the like may be used alone or in combination of two or more. In the present invention, polysaccharides such as starch preferably account for 50% or more of the adhesive in the antibacterial layer. More preferably, it is 80% or more. If it is less than 50%, the viscosity of the surface treatment liquid is lowered, which may cause adverse effects such as deterioration of strength and stiffness, and also increases the cost.

Furthermore, the surface treatment liquid (coating liquid) of the present invention may optionally contain various auxiliary agents such as a dispersant, a thickener, a water retention agent, an antifoaming agent, a water resistance agent, a coloring agent, and a conductive agent. may be used.
A device (coater) for applying the surface treatment liquid is not particularly limited, and a known device can be used. As the coater, not only a pound type size press, a film transfer type gate roll coater and a lot metering size press, but also a blade coater, a spray coater, a curtain coater and the like can be used. In addition, so-called calender sizing, in which an applicator or a spray is used in a calender, super calender, or the like, can also be performed. Furthermore, the coating liquid can be sprayed and applied in front of the Yankee dryer.

In the present invention, another layer may be provided in addition to the layer containing the sizing agent and the antimicrobial agent. That is, in addition to the layer containing the polysaccharide and the antibacterial agent, for example, a clear coating layer or a pigment coating layer may be provided.

After providing the clear coating layer on the base paper, the product may be finished by passing the paper through a known official finishing device such as a super calender, gloss calender, soft calender, high temperature soft nip calender, etc., or untreated or May be bypassed.

The present invention will be examined in detail by specific examples below, but the present invention should not be limited to the following specific examples. In this specification, unless otherwise specified, "parts" means "parts by weight", "%" means "% by weight", and numerical ranges are described including their end points.

Experiment 1. Confirmation of compatibility Various antibacterial agents were evaluated for compatibility with sizing agents and the like according to the following procedure.
(1) Compatibility between Various Antibacterial Agents and Sizing Agents Antibacterial agents with different ionic properties were mixed with sizing agents, and compatibility between the two was confirmed. Specifically, 5 ml of the antibacterial agent and 5 ml of the sizing agent were placed in a 20 ml vial, which was then capped and vigorously shaken by hand for 30 seconds.
(Antibacterial agent)
・Nonionic surfactant (Emulgen 106, Kao, solid concentration: 94%)
・ Anionic surfactant (Neopelex G-15, Kao, solid concentration: 16%)
・Zwitterionic surfactant (Amphitol 20N, Kao, solid concentration: 35%)
(Surface sizing agent)
・Surface sizing agent A (anionic copolymer, Polymaron 1308S, Arakawa Chemical Industries, concentration: 20%)
・Surface sizing agent B (alkyl ketene dimer, SE-2380, Seiko PMC, concentration: 25%)
After shaking, the mixture was allowed to stand for 20 minutes, and compatibility was visually evaluated based on the following criteria.
○ (Good): Maintains a clear or uniform dispersion state × (Poor): Sedimentation occurs, viscosity increases, paste or gelation occurs

When a nonionic antibacterial agent and a surface sizing agent were mixed, the viscosity increased significantly (anionic copolymer) and aggregation occurred (alkylketene dimer). On the other hand, even when the anionic antibacterial agent or the amphoteric antibacterial agent and the surface sizing agent were mixed, the properties of the mixed solution were good.
(2) Compatibility of Various Antibacterial Agents and Antifoaming Agents Antibacterial agents with different ionic properties were mixed with antifoaming agents, and compatibility between the two was confirmed. Compatibility was evaluated in the same manner as for the sizing agent, except that the sizing agent was replaced with the following antifoaming agent.
(Antifoaming agent)
・Antifoaming agent A (emulsion antifoaming agent, Bismer S-108, Nisshin Chemical Laboratory, solid content concentration: 1%)
・Antifoaming agent B (emulsion antifoaming agent, Kurileth 480, Kurita Water Industries, solid concentration: 1%)

Mixing a nonionic antibacterial agent and an antifoaming agent resulted in a large increase in viscosity, while mixing an anionic antibacterial agent or zwitterionic antibacterial agent with a surface sizing agent gave a good mixture.

Experiment 2. Production and evaluation of antibacterial paper (1) Production of antibacterial paper (Samples 1-4)
In a 1 L container, 533.7 g of starch solution (Nippon Shokuhin Kako, Nisshoku MS#3800, solids concentration: 6.6%), 1.05 g of anionic surface sizing agent (Polymaron 1308S, Arakawa Chemical Industries, solids concentration: 20%) and 14.0 g of an emulsion-based antifoaming agent (Kurileth 480, Kurita Kogyo, solid content concentration: 1%) are mixed, and then the following surfactant-based antibacterial agent is added to reduce the liquid volume to 600 g. A coating liquid was prepared by further adding ion-exchanged water (liquid temperature: 40° C.) so that the
(Antibacterial agent)
・Zwitterionic antibacterial agent (Amphitol 20N, Kao, solid content concentration: 35%) 0.87 g
・ Anionic antibacterial agent (Neopelex G-15, Kao, solid content concentration: 16%) 3.87 g
・Nonionic antibacterial agent (Amolden V-500HP, Daiwa Chemical Industry, solid concentration: 42%) 33.65g
Next, on both sides of base paper for woodfree paper (basis weight: about 60 g/m ² , neutral paper) that is neither pigment-coated nor clear-coated, ), and then air-dried for a whole day and night to prepare fine paper.
(2) Production of antibacterial paper (Samples 5-8)
In a 1 L container, 533.7 g of starch solution (Nihon Shokuhin Kako, Nisshoku MS#3800, solid content concentration: 6.6%), 0.84 g of surface sizing agent (alkylketene dimer, SE-2380, Seiko PMC, Solid content concentration: 25%), 14.0 g of emulsion antifoaming agent (Bismer S-108, Nisshin Chemical Laboratory, solid content concentration: 1%), 7.0 g of sodium chloride (Namishio, Naikai salt industry, concentration : 1%) was mixed, the following antibacterial agent was added, and ion-exchanged water (liquid temperature: 40°C) was further added so that the liquid volume became 600 g to prepare a coating liquid.
(Antibacterial agent)
・Zwitterionic surfactant (Amphitol 20N, Kao, solid content concentration: 35%) 0.87 g
・ Anionic surfactant (Neopelex G-15, Kao, solid concentration: 16%) 3.87 g
・Nonionic antibacterial agent (Emulgen 106, Kao, solid concentration: 94%) 33.65g
Next, on both sides of base paper for woodfree paper (basis weight: about 60 g/m ² , neutral paper) that is neither pigment-coated nor clear-coated, ), and then air-dried for a whole day and night to prepare fine paper.
(3) Evaluation of antibacterial paper The following evaluations were performed on the produced woodfree paper. When performing the evaluation, the sample was allowed to stand overnight in a constant temperature and humidity room (25° C., relative humidity: 50%) and used after being subjected to humidity conditioning.
(a) Application amount The basis weights before and after application were measured, and the application amount (g/m ² ) was calculated from these basis weights.
(b) antibacterial activity
Based on the antibacterial test method of JIS L1902, a fine paper sample of 2.8 cm × 2.8 cm was used as a test piece. After inoculating 0.2 mL of a test solution containing Staphylococcus aureus (test bacteria concentration: 1.0×10 ⁵ to 3.0×10 ⁵ CFU/mL) on the surface of the test piece, culture at 37° C. for 18 to 24 hours. did. Immediately after inoculation and after culturing, 20 mL of washing solution was added to wash out the test bacteria from the test piece, the number of viable bacteria in the washing solution was measured, and the antibacterial activity value (A) was calculated by the following formula. As a control sample, a washed cotton cloth (cotton No. 3-1) was used (JIS L0803).

As is clear from the table, simply applying starch to the paper substrate failed to impart antibacterial properties (Samples 1 and 5). Moreover, when a nonionic antibacterial agent was used, the antibacterial agent could not be applied to the base paper due to thickening or aggregation of the coating liquid (Samples 4 and 8).

On the other hand, by applying an antibacterial agent to the paper surface according to the present invention, fine paper having excellent antibacterial properties could be produced (Samples 2, 3, 6 and 7).

Claims (8)

A method of making an antimicrobial paper comprising applying an anionic antimicrobial agent and/or a zwitterionic antimicrobial agent and a surface sizing agent to a base paper. 2. The method of claim 1, wherein a coating solution containing said antimicrobial agent and said surface sizing agent is applied to the base paper. 3. The method of claim 1 or 2, wherein the antimicrobial agent comprises a surfactant. The method according to any one of claims 1 to 3, wherein the surface sizing agent comprises an anionic surface sizing agent or an alkylketene dimer. An antimicrobial paper having a layer on the base paper comprising an anionic antimicrobial agent and/or a zwitterionic antimicrobial agent and a surface sizing agent. 6. The antimicrobial paper of claim 5, wherein the layer containing the antimicrobial agent and the surface sizing agent is a clear coat layer containing starch. 7. The antibacterial paper according to claim 5 or 6, which is a fine paper without a pigment coating layer. The antibacterial paper according to any one of claims 5 to 7, wherein the surface sizing agent comprises an anionic surface sizing agent or an alkylketene dimer.