JP7428602B2 - Emulsion composition and its foam sheet - Google Patents

Description

The present invention relates to an emulsion composition and a foamed sheet thereof.

In order to prevent infections such as coronaviruses, resin molded products, fibers, sheets, etc. that have antiviral properties are being developed. Generally, these materials are manufactured by adding, impregnating, or coating a material with fillers (inorganic materials + titanium oxide, etc.) that adsorb/decompose viruses and bacteria.

For example, Patent Document 1 discloses that a resin molded article is brought into contact with a treatment liquid containing an antiviral compound (A) consisting of a quaternary ammonium halide having a molecular weight of 1500 or less, and the By performing the heat treatment, the antiviral compound (A) can be fixed to at least the surface of the resin molded product, and an excellent antiviral processed product with water resistance and washing durability can be obtained. Disclosed.

Furthermore, Patent Document 2 discloses that a photocatalyst-carrying sheet in which a photocatalyst layer containing titanium oxide and a copper compound is provided on at least one surface of a sheet base material containing a polymer resin has high antibacterial and antiviral properties. It is disclosed that the antibacterial and antiviral properties are fast-acting and last for a long period of time.

International Publication WO2016/009928 Japanese Patent Application Publication No. 2016-112480

The antiviral effect of resin molded products, fibers, sheets, etc. that have antiviral properties depends on the amount of exposure of the antiviral agent on the surface. For this reason, since the resin molded product of Patent Document 1 and the sheet of Patent Document 2 have a relatively small surface area, there is a risk that the antiviral effect may be insufficient. In addition, when using a tape with antiviral properties, that is, when it is desired to impart antiviral properties to an article that does not have antiviral properties (for example, a doorknob), a sheet such as that disclosed in Patent Document 2 is used. When used in the form of a tape, for example, the sheet has poor conformability to the shape of an article when attached, so it cannot follow the shape of, for example, a doorknob, resulting in floating portions. For this reason, there is a risk that the touch and texture may be poor, and the design may not be good. In addition, assuming that the tape is to be replaced at any time after it has been pasted and used, the adhesive strength of the tape is strong and there is a possibility that it may leave adhesive residue when it is removed and removed, making it time consuming to clean. There were cases in which the remaining adhesive stuck to hands, etc., making it unhygienic.

Therefore, the purpose of the present invention is to form a foam sheet that has excellent antiviral properties, has excellent tactile feel and texture due to its ability to follow shapes on curved surfaces, and has good workability during replacement due to its self-adhesive properties. An object of the present invention is to provide a possible emulsion composition and a foamed sheet formed by foaming and curing the emulsion composition.

The present inventors have made extensive studies to achieve the above object, and have found that an emulsion composition containing an antiviral agent and a surfactant at a specific concentration and a specific concentration ratio can solve the above problems. This discovery led to the completion of the present invention. That is, the present invention is as follows.

The present invention (1) is
An emulsion composition comprising a resin component, a surfactant, and an antiviral agent,
The solid content concentration ratio (Cs/ Cv) is 0.3 to 2.5,
The emulsion composition is characterized in that the total of the Cs and the Cv is 10 to 20% by mass.
The present invention (2) is
The emulsion composition according to the invention (1), wherein the antiviral agent is an inorganic antiviral agent.
The present invention (3) is
The emulsion composition according to the invention (1) or (2), wherein the surfactant has a pH of 7 or more.
The present invention (4) is
This is a foamed sheet obtained by foaming and curing the emulsion composition according to any one of the inventions (1) to (3).
The present invention (5) is
The emulsion composition according to the invention (4), wherein the foamed sheet has a density of 150 to 500 kg/m ³ .
The present invention (6) is
The emulsion composition according to the invention (4) or (5), wherein the foam sheet has a thickness of 0.5 to 1.5 mm.
The present invention (7) is
The foamed sheet is the emulsion composition according to any one of the inventions (4) to (6), characterized in that the stress at 25% compression in a 25° C. environment is 5 to 150 kPa.

According to the present invention, it is possible to form a foam sheet that has excellent antiviral properties, has excellent tactile feel and texture because it has the ability to follow shapes on curved surfaces, and has good workability when replacing because it has self-adhesive properties. It is possible to provide an emulsion composition and a foamed sheet formed by foaming and curing the emulsion composition.

1. Emulsion Composition The emulsion composition of the present invention includes a resin component, a surfactant, and an antiviral agent.

The emulsion composition of the present invention has a solid content that is between the solid content concentration (Cs) of the surfactant and the solid content concentration (Cv) of the antiviral agent when the mass of the entire solid content of the emulsion composition is 100% by mass. It is characterized by a concentration ratio (Cs/Cv) of 0.3 to 2.5.

The emulsion composition of the present invention is characterized in that the total amount of Cs and Cv is 10 to 20% by mass.

2. Raw materials for emulsion composition 2-1. Resin component The resin component according to the present invention is not particularly limited as long as it does not impede the effects of the present invention. Examples of the resin component include acrylic emulsions, styrene emulsions, urethane emulsions, ethylene vinyl acetate copolymer resin emulsions, vinyl chloride emulsions, and epoxy emulsions. These can be used alone or in combination. In particular, it is preferable to use an acrylic emulsion, a urethane emulsion, or an ethylene-vinyl acetate copolymer resin emulsion, more preferably an acrylic emulsion and a urethane emulsion, and even more preferable to use urethane. By using these materials, it is possible to obtain a foam sheet that has excellent antiviral properties, has excellent tactility and texture due to its ability to follow shapes on curved surfaces, and has good workability during replacement due to its self-adhesive properties. can.

As the acrylic emulsion, one manufactured by the following manufacturing method can be used.

The method for producing an acrylic emulsion involves using, for example, a (meth)acrylic acid ester monomer as an essential polymerizable monomer component in the presence of a polymerization initiator, an emulsifier and a dispersion stabilizer if necessary, and further It can be obtained by copolymerizing a mixture of these monomers and other polymerizable monomers, if necessary. Note that two or more types of acrylic emulsions may be used in combination. In addition, in this application, when described as (meth)acrylic ester, acrylic ester and methacrylic ester are included.

Polymerizable monomers that can be used in the production of acrylic emulsions include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)alrylate, and (meth)acrylate. Hexyl acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, octadecyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, nonyl (meth)acrylate, (meth)acrylate ) (meth)acrylic acid esters such as dodecyl acrylate, stearyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate, etc. System monomers: acrylic acid, methacrylic acid, β-carboxyethyl (meth)acrylate, 2-(meth)acryloylpropionic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, itaconic acid half ester, maleic acid half ester , unsaturated bond-containing monomers having carboxyl groups such as maleic anhydride, itaconic anhydride;
Glycidyl group-containing polymerizable monomers such as glycidyl (meth)acrylate and allyl glycidyl ether; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, glycerol mono(meth)acrylate; ) Hydroxyl group-containing polymerizable monomers such as acrylates;
Ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate Examples include meth)acrylate, diallyl phthalate, divinylbenzene, and allyl(meth)acrylate.

In addition, when using an emulsifier at the time of manufacturing an acrylic emulsion, a known emulsifier or the like may be used.

As the urethane emulsion, one manufactured by the following manufacturing method can be used.

Examples of methods for producing urethane emulsions include methods (I) to (III) below.
(I) If necessary, neutralize the organic solvent solution or organic solvent dispersion of the urethane resin having a hydrophilic group obtained by reacting an active hydrogen-containing compound, a compound having a hydrophilic group, and a polyisocyanate. A method to obtain a urethane emulsion by mixing aqueous solutions containing agents.
(II) A urethane prepolymer containing a terminal isocyanate group and having a hydrophilic group obtained by reacting an active hydrogen-containing compound, a compound having a hydrophilic group, and a polyisocyanate is mixed with an aqueous solution containing a neutralizing agent. Alternatively, a method in which a neutralizing agent is added in advance to a prepolymer, mixed with water to disperse the water, and then reacted with a polyamine to obtain a urethane emulsion.
(III) A urethane prepolymer containing a terminal isocyanate group and having a hydrophilic group obtained by reacting an active hydrogen-containing compound, a compound having a hydrophilic group, and a polyisocyanate is mixed with an aqueous solution containing a neutralizing agent and a polyamine. Alternatively, after adding a neutralizing agent to the prepolymer in advance, an aqueous solution containing a polyamine is added and mixed to obtain a urethane emulsion.

The polyisocyanates used in the production of the urethane emulsion include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, and 2,4-tolylene diisocyanate. '-Diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenylene diisocyanate, 3,3'-dichloro- 4,4'-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, dodecamethylene diisocyanate, trimethylhexamethylene diisocyanate, 1,3-cyclohexylene Diisocyanate, 1,4-cyclohexylylene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, hydrogenated xylylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 3,3'-dimethyl-4, Examples include 4'-dicyclohexylmethane diisocyanate. These can be used alone or in combination.

Examples of the compound having a hydrophilic group include polyolefin polyols such as polyester polyols, polyether polyols, polycarbonate polyols, polyacetal polyols, polyacrylate polyols, polyesteramide polyols, polythioether polyols, and polybutadiene-based polyolefin polyols. These can be used alone or in combination.

In the above-mentioned methods (I) to (III), an emulsifier can be further used within a range that does not impair the effects of the invention. Examples of emulsifiers include nonionic emulsifiers such as polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene styrenated phenyl ether, and polyoxyethylene sorbitol tetraoleate; fatty acid salts such as sodium oleate, and alkyl sulfates. Anionic emulsifiers such as ester salts, alkylbenzene sulfonates, alkyl sulfosuccinates, naphthalene sulfonates, alkanesulfonate sodium salts, alkyldiphenyl ether sulfonic acid sodium salts; polyoxyethylene alkyl sulfates, polyoxyethylene alkylphenyl sulfates, etc. nonionic anionic emulsifiers, etc. These can be used alone or in combination.

As the ethylene vinyl acetate copolymer resin emulsion, one manufactured by the following manufacturing method can be used.

As a method for producing an ethylene vinyl acetate copolymer resin emulsion, for example, polyvinyl alcohol or the like is used as a protective colloid, a cellulose derivative such as hydroxyethyl cellulose or a surfactant is used as an emulsifying dispersant, and ethylene and vinyl acetate monomers are combined. It can be obtained by copolymerizing by emulsion polymerization method.

The ethylene vinyl acetate copolymer resin emulsion may be one in which a vinyl monomer having a functional group such as a carboxyl group, an epoxy group, a sulfonic acid group, a hydroxyl group, a methylol group, or an alkoxy acid group is further copolymerized. .

The ethylene vinyl acetate copolymer resin emulsion can be used in combination of a plurality of ethylene vinyl acetate copolymer resin emulsions. By adjusting the blending amount of each ethylene vinyl acetate copolymer resin emulsion, its flexibility and material strength can be adjusted.

The dispersion medium of the emulsion composition is not particularly limited as long as it does not impede the effects of the present invention. Although water is an essential component of the dispersion medium of the emulsion composition, it may be a mixture of water and a water-soluble solvent. Water-soluble solvents include, for example, alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, ethyl carbitol, ethyl cellosolve, and butyl cellosolve, polar solvents such as N-methylpyrrolidone, etc., and these may be used alone or A combination of two or more can be used.

2-2. Surfactant The surfactant according to the present invention is not particularly limited as long as it does not inhibit the effects of the present invention. The surfactant can be used as a foaming agent or a foam stabilizer. As the surfactant, anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants can be used. These can be used alone or in combination. Among these, it is preferable to use an anionic surfactant and an amphoteric surfactant in combination.

Surfactants include those having a pH of 7 or more. Further, the upper limit of the pH of the surfactant is not particularly limited as long as it does not impede the effects of the present invention, but it can be set to, for example, pH 12 or lower, and pH 11 or lower is preferable. When the pH of the surfactant is within this range, it has excellent antiviral properties, has excellent tactile feel and texture because it can conform to curved surfaces, etc., and has self-adhesiveness, which makes it easier to replace. An emulsion composition capable of forming a good foam sheet can be obtained.

Anionic surfactants primarily function as foaming agents in emulsion compositions.

Specific examples of anionic surfactants include sodium laurate, sodium myristate, sodium stearate, ammonium stearate, sodium oleate, potassium oleate soap, potassium castor oil soap, potassium coconut oil soap, sodium lauroyl sarcosine, Sodium myristoyl sarcosine, sodium oleyl sarcosine, sodium cocoyl sarcosine, sodium coconut oil sulfate, sodium polyoxyethylene lauryl ether sulfate, sodium alkyl sulfosuccinate, sodium lauryl sulfoacetate, sodium alkylbenzene sulfonate, sodium α-olefin sulfonate, betaine Anionic surfactants can be created by adjusting the pH of amphoteric surfactants such as amphoteric surfactants, such as ammonium stearate, sodium alkylsulfosuccinate, and betaine. Anionic surfactants are preferred. These can be used alone or in combination. Further, it is preferable to use a combination of two or more anionic surfactants.

The anionic surfactant preferably has an HLB of 10 or more, more preferably 20 or more, and particularly preferably 30 or more, in order to facilitate dispersion in the emulsion composition. be.

By using an amphoteric surfactant in addition to an anionic surfactant, bubbles can be made fine and uniform.

In particular, when an anionic surfactant and an amphoteric surfactant are used together, the charges of the hydrophilic groups between the molecules of the anionic surfactant repel each other, and the molecules of the anionic surfactant maintain a certain distance from each other. In addition, by intercalating the electrically neutral bifacial active agent between the molecules of the anionic surfactant, the bubbles can be further stabilized and the size of the bubbles can be reduced. Therefore, the delamination strength can be improved. Therefore, it is preferable to use an anionic surfactant and an amphoteric surfactant together.

The amphoteric surfactant is not particularly limited as long as it does not impair the effects of the present invention, and for example, amino acid type, betaine type, amine oxide type, and other amphoteric surfactants can be used. Amphoteric surfactants can be used alone or in combination. Betaine-type amphoteric surfactants are preferred because they have higher effects. Furthermore, from the viewpoint of ease of infiltration between the molecules of the anionic surfactant, those having 10 to 12 carbon atoms are preferred.

Examples of amino acid type amphoteric surfactants include N-alkyl or alkenyl amino acids or salts thereof. N-alkyl or alkenyl amino acids have an alkyl or alkenyl group bonded to a nitrogen atom, and one or two "-R-COOH" (wherein R represents a divalent hydrocarbon group, preferably It is an alkylene group, preferably having 1 to 2 carbon atoms.) It has a structure in which a group represented by the following is bonded. In a compound in which one "-R-COOH" is bonded, a hydrogen atom is further bonded to the nitrogen atom. One "-R-COOH" is called a mono-form, and two "-R-COOH" are called a di-form. As the amphoteric surfactant according to the present invention, both of these mono- and di-forms can be used. In N-alkyl or alkenyl amino acids, the alkyl group or alkenyl group may be linear or branched. Specifically, amino acid type amphoteric surfactants include sodium lauryl diaminoethylglycine, sodium trimethylglycine, sodium cocoyl taurate, sodium cocoyl methyl taurate, sodium lauroyl glutamate, potassium lauroyl glutamate, lauroylmethyl-β-alanine, etc. be able to.

Examples of betaine-type amphoteric surfactants include alkylbetaines, imidazolinium betaines, carbobetaines, amidocarbobetaines, amidobetaines, alkylamidobetaines, sulfobetaines, amidosulfobetaines, and phosphobetaines. Specifically, betaine type amphoteric surfactants include lauryl betaine, stearyl betaine, lauryl dimethylamino acetic acid betaine, stearyl dimethyl amino acetic acid betaine, lauric acid amidopropyl dimethylamino acetic acid betaine, isostearic acid amidoethyl dimethylamino acetic acid betaine, Amidopropyl dimethylaminoacetate isostearate betaine, amidoethyl diethylaminoacetate betaine isostearate, amidopropyl diethylaminoacetic acid betaine isostearate, amidoethyl isostearate dimethylaminohydroxysulfobetaine, amidopropyl isostearate dimethylaminohydroxysulfobetaine, amidoethyl diethylamino isostearate Hydroxysulfobetaine, amidopropyl isostearate diethylaminohydroxysulfobetaine, N-lauryl-N,N-dimethylammonium-N-propylsulfobetaine, N-lauryl-N,N-dimethylammonium-N-(2-hydroxypropyl)sulfobetaine Betaine, N-lauryl-N,N-dimethyl-N-(2-hydroxy-1-sulfopropyl)ammonium sulfobetaine, laurylhydroxysulfobetaine, dodecylaminomethyldimethylsulfopropylbetaine, octadecylaminomethyldimethylsulfopropylbetaine, 2 -Alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine (2-lauryl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine) 2-stearyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, etc.), coconut oil fatty acid amidopropyl betaine, coconut oil fatty acid amidopropyl hydroxysultaine, and the like.

Examples of amine oxide type amphoteric surfactants include lauryldimethylamine-N-oxide and oleyldimethylamine-N-oxide.

Among these amphoteric surfactants, betaine type amphoteric surfactants are preferably used, and among the betaine types, alkyl betaines, imidazolinium betaines, and carbobetaines are particularly preferable. Examples of alkyl betaines include stearyl betaine and lauryl betaine, and examples of imidazolinium betaines include 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine.

2-3. Antiviral Agent The antiviral agent according to the present invention is not particularly limited as long as the effect of the present invention is not inhibited. As an antiviral agent, organic antiviral agents, inorganic antiviral agents, and antiviral surfactants can be used, but inorganic antiviral agents are preferred from the viewpoint of chemical reaction with the foam and deterioration due to the environment. preferable. Examples of inorganic antiviral agents include photocatalysts, metal compounds, and inorganic compounds. Examples of photocatalysts include composites in which copper, iron, or the like is supported on titanium oxide, tungsten oxide, or the like. Moreover, these can also be used by being supported on a porous body such as zeolite. Examples of the metal compound include compounds containing silver ions and the like, and combinations of metal ions and porous inorganic compounds such as zeolite, silica gel, and diatomaceous earth. Examples of inorganic compounds include calcium oxide derived from shells, calcium hydroxide such as slaked lime, and dolomite. These can be used alone or in combination. Among these, it is more preferable to use a photocatalyst such as titanium oxide or tungsten oxide, and slaked lime, and even more preferable are zeolite or apatite carrying titanium oxide and slaked lime. Zeolite carrying titanium oxide and slaked lime are more preferable. Particularly preferred.

The average particle size of the inorganic antiviral agent can be 0.1 to 30 μm, preferably 0.1 to 20 μm, and more preferably 0.1 to 10 μm. If the average particle size of the inorganic antiviral agent is within this range, the inorganic antiviral agent will not be completely embedded within the walls of the cells when it is made into a foam sheet, and will be released from the surface (wall surface) of the cells. A portion of the inorganic antiviral agent can be exposed. Furthermore, since the particles of the inorganic antiviral agent are sufficiently small, the surface area of the inorganic antiviral agent exposed on the walls of the cells can be increased, making the foam sheet excellent in antiviral properties. can.

The average particle size of the inorganic antiviral agent is measured using a particle counter.

2-4. Other Additives The emulsion composition of the present invention may contain other additives as long as they do not impede the effects of the present invention. Other additives include crosslinking agents, surfactants for water-dispersible resin dispersion, antioxidants, ultraviolet absorbers, antibacterial agents, dispersants, fillers, colorants, and other known additives. be able to.

By using a crosslinking agent, it is possible to improve the strength of a foamed sheet obtained by foaming and curing an emulsion composition.

Such a crosslinking agent is not particularly limited, and may be added in a necessary amount depending on the intended use. Examples of crosslinking methods using a crosslinking agent include physical crosslinking, ionic crosslinking, and chemical crosslinking, and the crosslinking method can be selected depending on the type of water-dispersible resin. As the crosslinking agent, known crosslinking agents can be used, such as epoxy crosslinking agents, melamine crosslinking agents, isocyanate crosslinking agents, carbodiimide crosslinking agents, oxazoline crosslinking agents, etc. An appropriate amount can be used depending on the type of group and the amount of functional group. In order to improve adhesive strength, tack strength and interlayer peel strength, epoxy crosslinking agents and isocyanate crosslinking agents are preferred. Isocyanate-based and epoxy-based crosslinking agents can prevent material destruction of adherends and porous foams by increasing material strength. Among them, aliphatic isocyanates are more preferred. Two or more of these crosslinking agents may be used in combination.

A surfactant for dispersing water-dispersible resin is a surfactant for dispersing water-dispersible resin (unlike the anionic surfactant mentioned above, it does not need to have the effect as a foaming agent) . Such a surfactant may be appropriately selected depending on the selected water-dispersible resin.

3. Characteristics of emulsion composition 3-1. Viscosity The viscosity of the emulsion composition of the present invention is not particularly limited, but can be, for example, 3,000 to 20,000 mPa·s, preferably 5,000 to 18,000 mPa·s, and 8,000 to 15 ,000 mPa·s is more preferable. When the viscosity of the emulsion composition is within this range, the foam retaining power during molding is sufficient, finer cells can be molded, the adhesive strength tends to be stronger, and the shear force on the raw material during molding is reduced. Since the adhesive strength can be reduced, it is possible to prevent cells having a distorted shape from being formed, so that more sufficient self-adhesive strength can be obtained.

The viscosity of the emulsion composition also affects the stirring efficiency. Stirring efficiency is considered to be one of the important factors, for example, in the formation of foam when manufacturing foam sheets by the mechanical floss method. An increase in stirring efficiency makes it possible to form bubbles that have entered the raw material into finer and more uniform shapes. It is thought that this increases the adhesion area to the adherend, thereby improving the adhesive strength to the adherend. It is also presumed that this has an influence on the strong sucker effect brought about by the fine cells.

The viscosity of the emulsion composition is measured by a Brookfield viscometer (25°C).

3-2. Glass Transition Temperature The glass transition temperature of the emulsion composition is not particularly limited, but can be from -30°C to 30°C, more preferably from -25°C to 25°C. When the glass transition temperature of the emulsion composition is within this range, it is possible to prevent the emulsion composition from increasing hardness or decreasing tack even when used in a low-temperature environment.

The glass transition temperature of the emulsion composition was measured using a dynamic viscoelasticity device in accordance with JIS-K7198 under the conditions of -80°C to 150°C, temperature rising at 5°C/min, and frequency of 1Hz. The temperature showing the peak value of tan δ is measured as the glass transition temperature.

4. Method for producing emulsion composition 4-1. Amount of Raw Materials In the present application, the components constituting the "solid content" of the emulsion composition are the components of the emulsion composition excluding the dispersion medium. Specifically, it contains a surfactant, other additives, etc. in addition to resin. The solid content refers to the residue left after removing the volatile components of the emulsion composition and drying it. The preferred blending ratio of the foam according to the present invention will be explained below. It should be noted that the blending amounts and blending ratios in the following description are based on solid content unless otherwise specified.

The emulsion composition preferably contains a solid content of 10 to 90% by mass based on the total amount of the emulsion composition, that is, the total amount of solid content and non-solid content is 100% by mass. It is more preferably 20 to 80% by mass, and even more preferably 30 to 75% by mass.

The solid content of the resin component (emulsion) can be 70 to 90% by mass, preferably 75 to 90% by mass, when the mass of the entire solid content of the emulsion composition is 100% by mass. It should be noted that the blending amounts and blending ratios in the following description are based on solid content unless otherwise specified.

The solid content of the surfactant can be 1 to 10% by mass, preferably 2 to 8% by mass, and preferably 2.5 to 7% by mass, when the mass of the entire solid content of the emulsion composition is 100% by mass. .5% by mass is more preferred, and 5 to 7.5% by mass is even more preferred. By setting this range, we can create a foam sheet that has excellent antiviral properties, has excellent tactility and texture due to its ability to follow shapes on curved surfaces, and has good workability when replacing due to its self-adhesive properties. , a formable emulsion composition can be obtained.

As the surfactant, it is preferable to use an anionic surfactant and an amphoteric surfactant in combination, and in that case, the mass of the solid content of the anionic surfactant (Ma) and the mass of the solid content of the amphoteric surfactant (Mz ) ratio (Ma:Mz) can be from 20:1 to 1:1, preferably from 15:1 to 5:1, more preferably from 15:1 to 10:1. By setting this range, we can create a foam sheet that has excellent antiviral properties, has excellent tactility and texture due to its ability to follow shapes on curved surfaces, and has good workability when replacing due to its self-adhesive properties. , a formable emulsion composition can be obtained.

The solid content of the antiviral agent can be 3 to 15% by mass, preferably 5 to 12% by mass, and preferably 6 to 12% by mass, when the mass of the entire solid content of the emulsion composition is 100% by mass. is more preferable, and even more preferably 8.5 to 11.5% by mass. By setting this range, we can create a foam sheet that has excellent antiviral properties, has excellent tactility and texture due to its ability to follow shapes on curved surfaces, and has good workability when replacing due to its self-adhesive properties. , a formable emulsion composition can be obtained.

The solid content concentration ratio (Cs/Cv) between the solid content concentration (Cs) of the surfactant and the solid content concentration (Cv) of the antiviral agent in the emulsion composition of the present invention is 0.3 to 2.5. , preferably 0.3 to 2.0, more preferably 0.34 to 1.84. By setting this range, we can create a foam sheet that has excellent antiviral properties, has excellent tactility and texture due to its ability to follow shapes on curved surfaces, and has good workability when replacing due to its self-adhesive properties. , a formable emulsion composition can be obtained.

The total (Cs+Cv) of the solid concentration (Cs) of the surfactant and the solid concentration (Cv) of the antiviral agent in the emulsion composition of the present invention is 10 to 20% by mass, and 11 to 19% by mass. Preferably, 11.6 to 18.6% by mass is more preferable. By setting this range, we can create a foam sheet that has excellent antiviral properties, has excellent tactility and texture due to its ability to follow shapes on curved surfaces, and has good workability when replacing due to its self-adhesive properties. , a formable emulsion composition can be obtained.

4-2. Blending The emulsion composition of the present invention can be prepared by mixing each raw material. Although the mixing method is not particularly limited, for example, the components may be mixed while being stirred in a container such as a mixing tank in which the components are mixed.

5. Application of emulsion composition The emulsion composition of the present invention can be used as a foam sheet by foaming and curing. The foam sheet according to the present invention has self-adhesive properties and can be bonded to an adherend without an adhesive. Therefore, by pasting it onto an article that has not been given antiviral properties, it is possible to impart antiviral properties to that article. Examples of articles include, but are not particularly limited to, those that come into contact with the human body, particularly doorknobs, handles, handles, and the like.

5-1. Properties of foamed sheet The density of the foamed sheet of the present invention can be 50 to 800 kg/m ³ , preferably 150 to 500 kg/m ³ , more preferably 150 to 400 kg/m ³ , and 150 to 230 kg/m ³ is more preferred, and 150 to 200 kg/m ³ is particularly preferred. When the density of the foam sheet is within this range, it has excellent antiviral properties, has excellent tactile feel and texture because it can conform to curved surfaces, etc., and has good workability when replacing because it has self-adhesive properties. It becomes a foam sheet.

The density of the foamed sheet is measured in accordance with JIS K7222:2005 "Foamed plastics and rubber - How to determine apparent density."

The thickness of the foamed sheet of the present invention is not particularly limited as long as the effects of the present invention are not impaired, but it can be 0.1 to 3.0 mm, preferably 0.5 to 1.5 mm, and 0.6 to 3.0 mm. 1.5 mm is more preferable, and 1 to 1.5 mm is even more preferable. When the thickness of the foamed sheet is within this range, it is possible to obtain a foamed sheet that has excellent tactile feel and texture because it has shape followability on curved surfaces and the like.

The stress of the foamed sheet of the present invention at 25% compression in a 25° C. environment (sometimes referred to as compression hardness (25% CLD) in this application) can be 5 to 150 kPa. When the compression hardness (25% CLD) of the foam sheet is within this range, the foam sheet has excellent shape conformability to curved surfaces and has excellent texture and texture.

The compression hardness (25% CLD) of the foamed sheet is measured by method D described in JIS K6254-2:2016 "Vulcanized rubber and thermoplastic rubber - How to determine stress-strain characteristics".

The adhesive strength of the foamed sheet of the present invention to a stainless steel (SUS) plate in a 25° C. environment can be 0.1 to 4.0 N/24 mm, preferably 0.4 to 1.2 N/24 mm. If the adhesive strength of the foam sheet to a stainless steel (SUS) plate in a 25°C environment is within this range, it will exhibit sufficient adhesive strength to various adherends and will be easy to attach and detach when replacing. The workability at the time of replacement is excellent.

The adhesive strength of the foamed sheet of the present invention to a stainless steel (SUS) plate in a 25°C environment is measured according to the 90° peel test described in JIS Z 0237:2009 "Adhesive tape/adhesive sheet testing method".

The tensile strength of the foam sheet of the present invention in a 25° C. environment can be 0.1 to 4.0 MPa, preferably 0.1 to 3.0 MPa. When the tensile strength of the foam sheet in a 25° C. environment is within this range, the effect that no material remains when peeled off can be obtained.

The tensile elongation at break of the foam sheet of the present invention in a 25°C environment can be 50% or more, preferably 100 to 400%, and more preferably 150 to 350%. When the tensile elongation at break of the foam sheet in a 25° C. environment is within this range, the effect of having curved surface followability can be obtained.

The tensile strength and tensile elongation at break of the foam sheet in a 25°C environment are measured according to JIS K6251:2010 "Vulcanized rubber and thermoplastic rubber - How to determine tensile properties".

The average cell diameter (sometimes referred to as average cell diameter) of the foam sheet can be 10 to 500 μm, preferably 20 to 300 μm, and more preferably 30 to 200 μm. When the average cell diameter of the foam sheet is within this range, it becomes possible to increase the surface area of the foam sheet, and the antiviral agent can be exposed on the wall surface of the foam sheet. Therefore, a foamed sheet with excellent antiviral properties can be obtained.

To measure the average bubble diameter of a foam sheet, the cross section of the foam sheet is photographed using a scanning electron microscope, and the photographed image is processed using commercially available software to determine the average projected area of each bubble on the image. The average bubble diameter is calculated using the area as the area of a circle.

5-2. Method for producing foamed sheet A foamed sheet can be obtained by foaming and curing the emulsion composition of the present invention.

5-2-1. Foaming method and foaming conditions As the foaming method used in the method for producing a foamed sheet according to the present invention, a mechanical floss (mechanical foaming) method is used. The mechanical floss method is a method in which the emulsion composition is stirred with a stirring blade or the like to mix air in the atmosphere into the emulsion composition and foam it. As the stirring device, any stirring device generally used in the mechanical floss method can be used without any particular restriction, but for example, a homogenizer, a dissolver, a mechanical floss foaming machine, etc. can be used. According to this mechanical floss method, porous foams with densities suitable for various uses can be obtained by adjusting the mixing ratio of the emulsion composition and air. It is possible to use other foaming methods in combination, but if foaming methods using chemical foaming agents are used in combination, the proportion of closed cells will increase, resulting in increased density and loss of flexibility of the porous foam. Therefore, it is not desirable.

The time for mixing the emulsion composition and air is not particularly limited, but is usually 1 to 10 minutes, preferably 2 to 6 minutes. The mixing temperature is also not particularly limited, but is usually room temperature. In addition, the stirring speed in the above mixing is preferably 200 rpm or more (more preferably 500 rpm or more) in order to make the bubbles finer, and preferably 2000 rpm or less (800 rpm or less is more preferable) in order to smoothly discharge the foam from the foaming machine. more preferred).

5-2-2. Formation of foamed sheet The emulsion composition foamed as described above (foamed emulsion composition) is formed into a foamed material such as a sheet having a desired thickness using known means such as a doctor knife or a doctor roll. be done.

5-2-3. Curing A known method can be used to cure the foam sheet. Although the foam sheet can be self-crosslinked, the foam sheet may also be cured by applying energy to crosslink the resin constituting the emulsion via a crosslinking agent. The step of applying energy is not particularly limited, but may include, for example, a heating step (thermal crosslinking).

In the heating step, the dispersion medium in the foamed emulsion composition formed into a sheet is evaporated. The drying method at this time is not particularly limited, but for example, hot air drying or the like may be used. Further, the drying temperature and drying time are not particularly limited, but may be, for example, about 80° C. for about 1 to 3 hours.

Further, in this heating step, the dispersion medium evaporates from the foamed emulsion composition, and the path through which this vapor escapes is communicated from the inside of the porous foam to the outside. Therefore, in the foam sheet, the passage for this water vapor to escape remains as open cells, so that at least some of the cells present in the porous foam become open cells. Here, if the mixed foaming gas remains as it is, it becomes closed cells in the obtained porous foam, and the mixed foaming gas is communicated with when the steam escapes in this process. In some cases, the resulting porous foam has open cells. That is, in the present invention, a part of the cells in the porous foam are open cells, and the remaining cells are closed cells, resulting in a semi-open cell structure in which open cells and closed cells coexist.

When a crosslinking agent is added, the heating step progresses and completes the crosslinking reaction of the raw materials. Specifically, the raw materials are crosslinked with each other by the above-mentioned crosslinking agent, and a cured porous foam is formed. The heating means at this time is not particularly limited as long as it can sufficiently heat the raw material and crosslink the raw material, and for example, a tunnel heating furnace or the like can be used. Further, the heating temperature and heating time may be any temperature and time that can crosslink the raw materials, for example, about 1 hour at 80 to 150°C (particularly preferably about 120°C).

<<Preparation of emulsion composition>>
<Raw materials>
<Water dispersible resin>
・Acrylic resin emulsion 1: Acrylic copolymer, solid content 54%, pH 9, viscosity 12,000 mPa・s, Tg = -20°C (calculated value), (manufactured by Aica Kogyo Co., Ltd.)
・Urethane resin emulsion 1: Polycarbonate type, solid content 60%, pH 8
・Ethylene-vinyl acetate copolymer emulsion 1: Solid content 55%, pH 8.5, viscosity 2,500 mPa・s, Tg -18°C (manufactured by Sumika Chemtex)
<Surfactant>
・Anionic surfactant 1: ammonium stearate, pH 11, solid content 33%
・Anionic surfactant 2: Sodium alkyl sulfosuccinate, pH 9.4, solid content 30%, HLB 39.7
・Anionic surfactant 3: Alkyl betaine, fatty acid alkanolamide, diethanolamine, anionic surfactant mixed system, pH 10, solid content 30.5%
・Ampholytic surfactant: alkyl betaine, pH 10, solid content 40%
<Antiviral agent>
Antiviral agent 1: Zeolite + titanium oxide, particle size: 0.2 to 0.4 μm
Antiviral agent 2: Apatite + titanium oxide, particle size: 3 to 8 μm
Antiviral agent 3: Plaster (slaked lime)
<Crosslinking agent>
Crosslinking agent 1: Hydrophobic HDI isocyanurate: Number of functional groups: 3.5

<Preparation of emulsion composition>
<Emulsion composition of Example 1>
Acrylic resin emulsion 1 and urethane resin emulsion 1 are used as main ingredients, and based on the total amount of the emulsion (the total amount of solid content and non-solid content is 100 parts by weight), 4 parts by weight for each 50:50 parts by weight parts by weight of anionic surfactant 1, 3 parts by weight of anionic surfactant 2, 3 parts by weight of anionic surfactant 3, 1 part by weight of amphoteric surfactant, 15 parts by weight of antiviral agent 1, 2 The emulsion composition of Example 1 was prepared by mixing 0.0 parts by weight of crosslinking agent.
<Emulsion compositions of Examples 2 to 14 and Comparative Examples 1 to 5>
The emulsions of Examples 2 to 14 and Comparative Examples 1 to 5 were prepared in the same manner as the emulsion composition of Example 1 except that the raw materials were blended in the proportions shown in Tables 1 to 2 (corresponding to Examples 2 to 14). A composition was prepared.

<<Preparation of foam sheet>>
<Production of foam sheet>
Air was added to the obtained emulsion compositions of Examples and Comparative Examples to foam them using the mechanical floss method (foaming conditions: 100 to 1000 rpm), and after casting on a base material, heat treatment (oven or drying oven) was performed. As a result, foamed sheets of each Example and Comparative Example were obtained.

<<Measurement/Evaluation>>
<Thickness>
The thickness of the foamed sheets of each Example and Comparative Example was measured using a thickness gauge. The results are shown in Tables 1 and 2.

<Density measurement>
The density of the foamed sheets of each Example and Comparative Example was measured according to JIS K7222:2005 "Foamed plastics and rubber - How to determine apparent density." Specifically, it was measured by calculating the weight per unit volume. The results are shown in Tables 1 and 2.

<Compression hardness (25% CLD) measurement>
The compression hardness of the foamed sheets of each example and comparative example is based on the compression of JIS K6254:2016 "Vulcanized rubber and thermoplastic rubber - How to determine stress-strain properties", and the compression hardness is determined when compressed by 25% of the thickness. The load was measured. Specifically, the load is when a φ50 sample is crushed by 25% of its thickness (to 75% of the original sample thickness) at a speed of 1.0 mm/min using a 100φ compression plate. was measured and the compression hardness was calculated. The results are shown in Tables 1 and 2.

<Adhesive strength (SUS) measurement>
The foam sheets of each Example and Comparative Example were punched out into 24 mm width x 150 mm, and to eliminate the influence of elongation, single-sided adhesive tape was fixed on the surface (non-adhesive side) of the foam. The tape was pasted on a sheet of paper (manufactured by Sangetsu Co., Ltd., model number LB-9721), pressed back and forth twice with a 2 kg roller, and left at room temperature for 24 hours. Thereafter, using an Instron type material testing machine (Autograph manufactured by Shimadzu Corporation), the crosshead speed was increased to 300 mm/min, and a 90° peel test was performed to determine the adhesive strength. The test was conducted according to the 90° peel test described in JIS Z 0237:2009 "Adhesive Tape/Adhesive Sheet Test Method". The results are shown in Tables 1 and 2.

<Tensile strength measurement, tensile elongation at break measurement>
The tensile strength and tensile elongation at break of the foamed sheets of each Example and Comparative Example were measured in accordance with JIS K6251:2010 "Vulcanized rubber and thermoplastic rubber - How to determine tensile properties". Specifically, a dumbbell-shaped No. 3 test piece was created from the foam sheets of each example and comparative example, and the crosshead speed was measured using an Instron type material testing machine (manufactured by Shimadzu Corporation, Autograph). A tensile test was conducted at 200 mm/min, and the stress and elongation at break were measured. The results are shown in Tables 1 and 2.

<Moldability evaluation>
The surface of the foamed sheets of each Example and Comparative Example was visually observed to evaluate the moldability. If the cell diameter was uniform, 5 points were given, if cells coalesced, 3 points were given, and if surface cracking occurred, 0 points were given. The results are shown in Tables 1 and 2.

<Evaluation of shape followability>
The shape followability of the foam sheets of each example and comparative example was determined by the amount of air trapped when each foam sheet was processed into a length of 160 mm x width of 50 mm and attached to a doorknob (manufactured by Miwa Lock Co., Ltd., model: MIWA HM). was evaluated by observing with the naked eye. The evaluation was given as 1 point if the adhesive could be pasted without entrapping air, and 0 point if air was entrapped. The results are shown in Tables 1 and 2.

<Tactile evaluation>
The foam sheets of each Example and Comparative Example were processed to have a length of 160 mm and a width of 50 mm, and were attached to a doorknob (manufactured by Miwa Lock Co., Ltd., model: MIWA HM). Five evaluators who selected the doorknob at random used the doorknob to evaluate the feel of the foam sheet based on the following criteria. The evaluation for which more than half of the judgment results of five people was given was regarded as the tactile evaluation. The results are shown in Tables 1 and 2.
2 points: Softness and smoothness are clearly felt.
1 point: Soft, but with some tackiness.
0 point: Feels hard and feels uncomfortable.

<Evaluation of adhesive residue>
The foam sheets of each example and comparative example were processed into a length of 160 mm x width of 50 mm, pasted on a doorknob (manufactured by Miwa Lock Co., Ltd., model: MIWA HM), left for one week, and then peeled off by hand. The adhesive residue was observed with the naked eye and evaluated using the following criteria. The results are shown in Tables 1 and 2.
2 points: If there is no adhesive residue on the peeled surface of the doorknob 1 point: If there is adhesive residue on less than 50% of the peeled surface of the doorknob 0 points: If there is glue residue on more than 50% of the peeled surface of the doorknob or foam sheet If the is broken

<Antiviral activity value evaluation>
(Examples 1 to 13, Comparative Examples 1 to 5)
The antiviral activity values of the foamed sheets of Examples 1 to 13 and Comparative Examples 1 to 5 were measured in accordance with JIS R1706:2013 "Fine ceramics - Antiviral test method for photocatalytic materials - Method using bacteriophage Qβ" did. Specifically, the foamed sheets of Examples 1 to 13 and Comparative Examples 1 to 5 were irradiated with ultraviolet light with an ultraviolet light intensity of 0.25 mW/cm ² for 4 hours, and the antiviral activity values were calculated. The results are shown in Tables 1 and 2.
(Example 14)
The antiviral activity value of the foamed sheet of Example 14 was measured in accordance with JIS R1706:2013 "Fine ceramics - Antiviral property testing method for photocatalytic materials - Method using bacteriophage Qβ". Specifically, the foamed sheet of Example 14 was allowed to stand still for 4 hours in the dark, and the antiviral activity value was calculated. The results are shown in Tables 1 and 2.
(Evaluation criteria)
The antiviral activity values obtained by the above method were evaluated using the following criteria. The results are shown in Tables 1 and 2.
5 points: If the antiviral activity value is 3.0 or more 3 points: If the antiviral activity value is 2.0 or more and less than 3.0 0 points: If the antiviral activity value is less than 2.0

<Overall Judgment>
The evaluation scores for the above evaluation items were totaled, and an overall judgment was made based on the following judgment criteria. The results are shown in Tables 1 and 2.
○: Total score is 14 to 15 points △: Total score is 10 to 13 points ×: Total score is 9 points or less

Claims (7)

An emulsion composition comprising a resin component, a surfactant, and an antiviral agent,
The solid content concentration ratio (Cs/ Cv) is 0.3 to 2.5,
An emulsion composition characterized in that the total of the Cs and the Cv is 10 to 20% by mass when the mass of the entire solid content of the emulsion composition is 100 % by mass. The emulsion composition according to claim 1, wherein the antiviral agent is an inorganic antiviral agent. The emulsion composition according to claim 1 or 2, wherein the surfactant has a pH of 7 or more. A foamed sheet obtained by foaming and curing the emulsion composition according to any one of claims 1 to 3. The foam sheet according to claim 4, wherein the foam sheet has a density of 150 to 500 kg/m ³ . The foam sheet according to claim 4 or 5, wherein the foam sheet has a thickness of 0.5 to 1.5 mm. The foam sheet according to any one of claims 4 to 6, wherein the foam sheet has a stress of 5 to 150 kPa at 25% compression in a 25°C environment.