JP2023136103A - Coating and method for producing coating - Google Patents

Abstract

To provide a coating that includes a water dispersion of polyurethane resin and can form a coating layer with excellent coating suitability and excellent antibacterial property.SOLUTION: A coating includes a water dispersion of polyurethane resin, and an antibacterial agent. The polyurethane resin includes (A) a polyurethane resin having a silanol group. The antibacterial agent includes (B) a silane compound having a quaternary ammonium salt structure and a silanol group.SELECTED DRAWING: None

Description

The present invention relates to a paint and a method for producing the paint.

BACKGROUND ART Conventionally, for example, building materials, vehicle interior materials, furniture materials, packaging materials, and the like have been coated with paint for the purpose of improving aesthetics and protecting them. In recent years, from the standpoint of environmental issues and safety, there has been a demand for water-based paints that use as little organic solvent as possible. In addition, polyurethane resins are widely used as binders for water-based paints from the viewpoint of excellent physical properties such as abrasion resistance and bending resistance of the paint film, and from the viewpoint of appearance such as texture and luxury.

For example, Patent Document 1 discloses a paint containing a siloxane-modified urethane resin, polyurethane gel particles, and a crosslinking agent as a paint for the skin layer of synthetic simulated leather (a general term for artificial leather and synthetic leather). There is. Furthermore, Patent Document 2 describes a polymer polyol, a compound having one or more active hydrogens in its molecule and a hydrophilic group, a dihydric alcohol, a polyisocyanate, and two primary amino groups and a A matte coating containing an aqueous polyurethane urea dispersion which is the reaction product of a polyamine having one or more secondary amino groups is disclosed. Furthermore, Patent Document 3 describes a polyol component containing a polymer polyol, a compound having one or more active hydrogens and a hydrophilic group in the molecule, a dihydric alcohol, and a trihydric or higher alcohol, and a polyisocyanate. and a polyamine having two primary amino groups and one or more secondary amino groups, and contains a polyurethaneurea aqueous dispersion with an acid value of 1 to 16 mgKOH/g in terms of solid content. A matte paint is disclosed.

Japanese Patent Application Publication No. 2009-001713 JP 2019-011408 Publication JP2020-097707A

On the other hand, in addition to the increasing awareness of hygiene in the living environment, the global spread of the new coronavirus has become a major factor, and various items surrounding the living environment, such as wallpaper, doorknobs, handles, instrument panels, tables, and sofas, The demand for antibacterial treatment is rapidly increasing.

In order to impart antibacterial properties to the paint film, an antibacterial agent may be added to the paint. However, as a result of studies conducted by the present inventors, it has been found that when a silver-based inorganic antibacterial agent, which is widely used as an antibacterial agent, is added to a paint that uses an aqueous dispersion of polyurethane resin, the silver-based inorganic antibacterial agent tends to precipitate. It was found that the suitability of the paint decreased. In the case of paints in which antibacterial agents tend to settle and have low dispersibility, there is a risk of uneven antibacterial properties in the paint film.

Therefore, the present invention aims to provide a paint using an aqueous dispersion of polyurethane resin that has good paint suitability and can form a coating film with good antibacterial properties. be.

According to the present invention, an aqueous dispersion of a polyurethane resin and an antibacterial agent are contained, the polyurethane resin includes a polyurethane resin (A) having a silanol group, and the antibacterial agent is a quaternary ammonium salt. A coating material is provided that includes a silane compound (B) having a structure and a silanol group.

According to the present invention, it is possible to provide a coating material using an aqueous dispersion of a polyurethane resin, which has good coating suitability and is capable of forming a coating film having good antibacterial properties. .

Embodiments of the present invention will be described below, but the present invention is not limited to the following embodiments.

<Paint>
The paint of one embodiment of the present invention (hereinafter, sometimes simply referred to as "paint" or "paint of this embodiment") contains an aqueous dispersion of polyurethane resin and an antibacterial agent. The above polyurethane resin includes a polyurethane resin (A) having a silanol group (hereinafter sometimes simply referred to as "polyurethane resin (A)" or "silanol group-containing polyurethane resin (A)"). . In addition, the above antibacterial agent is a silane compound (B) having a quaternary ammonium salt structure and a silanol group (hereinafter simply referred to as "silane compound (B)" or "quaternary ammonium salt-containing silane compound (B)"). ). In this specification, the term "silanol group" includes a group that produces a silanol group upon hydrolysis.

The paint of this embodiment contains an aqueous dispersion of a silanol group-containing polyurethane resin (A) and a quaternary ammonium salt-containing silane compound (B) which is an antibacterial agent, so it has good paint suitability, and , it is possible to form a coating film with good antibacterial properties. Specifically, it forms a coating film that has good antibacterial properties while exhibiting good paint suitability such as good dispersibility and resistance to sedimentation of polyurethane resin (A) and antibacterial agent (silane compound (B)). It is possible to do so.

In one aspect of the paint of this embodiment, the silane compound (B) can be contained separately from the polyurethane resin (A), that is, in a chemically unbonded state. . In this case, the polyurethane resin (A) and the silane compound (B) both have silanol groups, so when forming a coating film containing them separately, the polyurethane resin (A) and the silane compound (B) It is possible to carry out a condensation reaction with the silane compound (B). In addition, in one aspect of the coating material of the present embodiment, the silane compound (B) is used as a condensation reaction product of the silanol groups possessed by the polyurethane resin (A) and the silane compound (B), respectively. It is also possible to contain it in the resin (A) integrally, that is, in a chemically bonded state. In any of the above embodiments, the coating film formed from the paint does not contain an antibacterial agent because the quaternary ammonium salt-containing silane compound (B), which is an antibacterial agent, can be immobilized on the polyurethane resin (A). It can be expected to have a level of abrasion resistance comparable to that of other materials, and as a result, it can also be expected to have long-lasting antibacterial properties.

Each component of the paint of this embodiment will be described in detail below, including preferred configurations from the viewpoint of easily obtaining the intended paint.

[Aqueous dispersion of polyurethane resin (A)]
The paint of this embodiment contains an aqueous dispersion of a polyurethane resin (A) having a silanol group (a silanol group-containing polyurethane resin (A)) as an aqueous dispersion of a polyurethane resin. The paint of this embodiment may contain an aqueous dispersion of a polyurethane resin other than the aqueous dispersion of the polyurethane resin (A) within a range that does not impair its purpose. In this specification, "polyurethane resin" is a general term for polyurethane resin, polyurea resin, and polyurethane-urea resin.

The silanol group-containing polyurethane resin (A) preferably comprises a urethane prepolymer having an isocyanate group (hereinafter sometimes referred to as an "NCO group") and a compound having an amino group and an alkoxysilyl group (f ) can be obtained by reacting with an amine compound containing That is, the reactant (product) resulting from the reaction can be used as the silanol group-containing polyurethane resin (A). Further, the above-mentioned urethane prepolymer having an NCO group preferably contains a compound (a) having an anionic hydrophilic group other than a hydroxyl group and an active hydrogen-containing group other than the anionic hydrophilic group, a polyol, and a polyamine. It can be obtained by reacting a reaction component containing at least one compound (b) selected from the group consisting of polyisocyanate (e). That is, the reaction product (product) of the reaction component can be used as the above-mentioned urethane-based prepolymer having an NCO group.

The above urethane prepolymer having an NCO group contains, in addition to the above compound (a), compound (b), and polyisocyanate (e), a chain extender (c) and a polyurethane prepolymer having an active hydrogen-containing group. Preferably, it is obtained using siloxane (d). That is, the above urethane prepolymer having an NCO group contains a compound (a), a compound (b), a chain extender (c), a polysiloxane (d) having an active hydrogen-containing group, and a polyisocyanate ( Preferably, it is a reaction product with e). In this case, it is more preferable to use at least a polycarbonate polyol (b1) as the compound (b), and it is more preferable to use at least a dihydric alcohol as the chain extender (c).

In this specification, "active hydrogen-containing group other than anionic hydrophilic group" refers to a functional group having active hydrogen that is reactive with an isocyanate group, excluding the anionic hydrophilic group. means. Specific examples of such "active hydrogen-containing groups" include hydroxyl groups, mercapto groups, and amino groups.

(Compound (a))
The compound (a) (hereinafter sometimes simply referred to as "compound (a)") having an anionic hydrophilic group other than a hydroxyl group and an active hydrogen-containing group other than the anionic hydrophilic group is a polyurethane-based It is suitably used as a component that imparts water dispersibility to the resin (A). By using the compound (a) as a raw material for the polyurethane resin (A), it is possible to obtain the polyurethane resin (A) into which an anionic hydrophilic group is introduced. As a result, the polyurethane resin (A) can be stably dispersed in water without using an emulsifier (surfactant), and the paint of this embodiment can be prepared as a water-based paint. It is.

In compound (a), active hydrogen is a hydrogen atom that reacts with an isocyanate group of polyisocyanate, and includes hydrogen atoms such as a hydroxyl group, a mercapto group, and an amino group. Among these, a hydrogen atom of a hydroxyl group is preferred. Further, in compound (a), the anionic hydrophilic group refers to an anionic group that exhibits affinity with water, and refers to a group that can ionize in water to produce an anion. Examples of anionic hydrophilic groups other than hydroxyl groups include carboxy groups, sulfo groups, and phosphoric acid groups. Among these, a carboxy group is preferred. The anionic hydrophilic group may be completely or partially neutralized.

Examples of compound (a) include 2,2-bis(hydroxymethyl)propionic acid (also known as dimethylolpropionic acid), 2,2-bis(hydroxymethyl)butyric acid (also known as dimethylolbutanoic acid), lactic acid, and carboxylic acid compounds such as glycine; and sulfonic acid compounds such as 2-aminoethanesulfonic acid (also known as taurine) and sulfoisophthalic acid polyester diol. One or more of these can be used. Among these, dihydric alcohol carboxylic acid compounds are preferred from the viewpoint of ease of availability and ease of adjusting acid value, and dimethylolalkanoic acids such as dimethylolpropionic acid and dimethylolbutanoic acid are preferable. is more preferable.

All or part of the anionic hydrophilic group may be neutralized with a neutralizing agent. The anionic hydrophilic group in the compound (a) may be neutralized, and a salt-type compound (a) having the neutralized anionic hydrophilic group may be used, or the compound (a) may be introduced into the polyurethane resin (A). A salt-type polyurethane resin (A) in which the anionic hydrophilic groups are neutralized may be used. Examples of neutralizing agents include alkylamines such as ethylamine, trimethylamine, triethylamine, triisopropylamine, and tributylamine; triethanolamine, N-methyldiethanolamine, N-phenyldiethanolamine, monoethanolamine, dimethylethanolamine, diethylethanol. Examples include amines and alkanolamines such as 2-amino-2-ethyl-1-propanol; alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; and the like. Among these, tertiary alkylamines such as triethylamine, tertiary alkanolamines such as dimethylaminoethanol, and sodium hydroxide are preferred.

The content (amount used) of the compound (a) in the reaction component can be set from the viewpoint of achieving both water dispersibility and water resistance of the resulting polyurethane resin (A). Specifically, the content (amount used) of compound (a) in the reaction component is preferably such that the acid value of the obtained polyurethane resin (A) is 2 to 200 mgKOH/g, and 5 to 200 mgKOH/g. More preferably, the amount is 100 mgKOH/g.

(Compound (b))
At least one compound (b) selected from the group consisting of polyols and polyamines (hereinafter sometimes simply referred to as "compound (b)") constitutes the main skeleton of the polyurethane resin (A). It is a moisturizing ingredient. Since a polyol and/or a polyamine is used for compound (b), it will be hereinafter referred to as "polyol (b),""polyamine(b)," and "polyol and/or polyamine (b)." There is. Among the compounds (b), it is preferable to use at least the polyol (b).

Polyol (b) is a compound having two or more hydroxyl groups in one molecule. As the polyol (b), one or more conventionally known polyols used in urethane synthesis can be used. As the polyol (b), a polyol having a number average molecular weight (Mn; determined by terminal functional group determination) of 500 or more, as well as a short chain diol and a trihydric or higher polyhydric alcohol suitable as the chain extender (c) described below, are used. can be mentioned.

Among the polyols (b), polyols having an Mn of 500 or more as determined by terminal functional group determination are preferred, and specific examples thereof include polyester polyols, polyether polyols, polycarbonate polyols, and other polyols. Among these, polycarbonate polyol (herein sometimes referred to as "polycarbonate polyol (b1)") is more preferred.

Polyester polyols include aliphatic dicarboxylic acids (e.g., succinic acid, adipic acid, sebacic acid, glutaric acid, azelaic acid, etc.) and/or aromatic dicarboxylic acids (e.g., isophthalic acid, terephthalic acid, etc.), Molecular weight glycols (e.g., ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,6-hexamethylene glycol, neopentyl glycol, 1,4-bishydroxymethylcyclohexane, etc.) ) and those obtained by condensation polymerization.

Specific examples of such polyester polyols include polyethylene adipate diol, polybutylene adipate diol, polyhexamethylene adipate diol, polyneopentyl adipate diol, polyethylene/butylene adipate diol, polyneopentyl/hexyl adipate diol, poly-3- Examples include methylpentane adipate diol, polybutylene isophthalate diol, polycaprolactone diol, and poly-3-methylvalerolactone diol.

Specific examples of polyether polyols include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and random/block copolymers thereof.

Specific examples of polycarbonate polyols include polytetramethylene carbonate diol, polypentamethylene carbonate diol, polyneopentyl carbonate diol, polyhexamethylene carbonate diol, poly(1,4-cyclohexane dimethylene carbonate) diol, and random / Polycarbonate diols such as block copolymers can be mentioned.

Specific examples of other polyols include dimer diol, polybutadiene polyol and its hydrogenated product, polyisoprene polyol and its hydrogenated product, polylactone polyol, acrylic polyol, epoxy polyol, polyether ester polyol, siloxane-modified polyol, α, Examples include ω-polymethyl methacrylate diol and α,ω-polybutyl methacrylate diol.

The number average molecular weight (Mn; determined by terminal functional group determination) of the polyol (b) is not particularly limited, but is preferably from 500 to 3,000. When the Mn of the polyol (b) is 3,000 or less, the cohesive force of the urethane bonds is likely to be expressed, and the mechanical properties tend to be improved. Furthermore, crystalline polyols with Mn of 3,000 or less are less likely to cause whitening when formed into a film.

Polyamine (b) is a compound having two or more amino groups in one molecule. The polyamine (b) is a component that can constitute the main skeleton of the polyurethane resin (A) when used alone or in combination with the above-mentioned polyol (b). Examples of the polyamine (b) include polyamines having a number average molecular weight (Mn; determined by terminal functional group determination) of 500 or more, and short-chain diamines suitable as the chain extender (c) described below. One or more types of polyamines (b) can be used. Among these, polyamines (b) having Mn of 500 or more are preferred, and specific examples thereof include long-chain alkylene diamines, polyoxyalkylene diamines, terminal amine polyamides, and siloxane-modified polyamines.

(Chain extender (c))
Examples of the chain extender (c) that can be used in the synthesis of the urethane prepolymer having an NCO group include short chain diols (dihydric alcohols), polyhydric alcohols having a valence of 3 or more, and short chain diamines. One or more types of chain extenders (c) can be used. Among the chain extenders (c), it is preferable to use at least short chain diols.

The short chain diol that can be used as the chain extender (c) is a diol compound having a number average molecular weight (Mn) of less than 500. The number average molecular weight of a short chain diol is an arithmetic average value of molecular weights calculated from the formula weight. Examples of short chain diols include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 1,6-hexamethylene glycol, and neopentyl. Aliphatic glycols such as glycols and their low molar alkylene oxide adducts (Mn less than 500); alicyclic glycols such as 1,4-bishydroxymethylcyclohexane and 2-methyl-1,1-cyclohexanedimethanol. , and low molar alkylene oxide adducts thereof (Mn less than 500); aromatic glycols such as xylylene glycol and low molar alkylene oxide adducts thereof (Mn less than 500); bisphenols such as bisphenol A, thiobisphenol, and sulfone bisphenol; and alkylene oxide low molar adducts thereof (Mn less than 500); and compounds such as alkyl dialkanolamines such as alkyl diethanolamine having an alkyl group having 1 to 18 carbon atoms. One or more short chain diols can be used.

Further, examples of the trihydric or higher polyhydric alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and tris-(2-hydroxyethyl)isocyanurate. One or more types of polyhydric alcohols having a valence of 3 or more can be used.

The short chain diamine that can be used as the chain extender (c) is a diamine compound having a number average molecular weight (Mn) of less than 500. The number average molecular weight of a short chain diamine is an arithmetic average value of molecular weights calculated from the formula weight. Examples of short-chain diamines include aliphatic diamine compounds such as ethylenediamine, trimethylenediamine, hexamethylenediamine, and octamethylenediamine; phenylenediamine, 3,3'-dichloro-4,4'-diaminodiphenylmethane, 4,4 Aromatic diamine compounds such as '-methylenebis(phenylamine), 4,4'-diaminodiphenyl ether, and 4,4'-diaminodiphenylsulfone; cyclopentanediamine, cyclohexyldiamine, 4,4-diaminodicyclohexylmethane, 1,4 - alicyclic diamine compounds such as diaminocyclohexane and isophorone diamine; hydrazines such as hydrazine, carbodihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, and phthalic acid dihydrazide; and the like. One or more short chain diamines can be used.

(Polysiloxane (d) having active hydrogen-containing group)
A polysiloxane (d) having at least one active hydrogen-containing group in one molecule may be used to synthesize a urethane prepolymer having an NCO group. The polysiloxane (d) having an active hydrogen-containing group can be used when polyurethane resin (A) is modified with polysiloxane. By using polysiloxane (d) in the synthesis of polyurethane resin (A), polysiloxane segments can be contained in polyurethane resin (A). This polysiloxane segment is contained in the main chain of the polyurethane resin (A) or in a branched state. By modifying the polyurethane resin (A) with polysiloxane, it is expected that the scratch resistance and stain resistance of the coating film will be improved.

Examples of the polysiloxane (d) having an active hydrogen-containing group include amino-modified polysiloxane, epoxy-modified polysiloxane, alcohol-modified polysiloxane, and mercapto-modified polysiloxane. One or more of these can be used. Note that epoxy-modified polysiloxane is a polysiloxane that has been epoxy-modified using an active hydrogen-containing group, but since it can react with the isocyanate group of polyisocyanate to form the skeleton of the polyurethane resin (A), Included in polysiloxanes having at least one active hydrogen-containing group.

Examples of the amino-modified polysiloxane include compounds represented by each of the following general formulas (1) to (6).

Examples of the epoxy-modified polysiloxane include compounds represented by each of the following general formulas (7) to (12). In addition, the epoxy compounds represented by each of the following general formulas (7) to (12) may be used by reacting with polyol, polyamide, polycarboxylic acid, etc. to have an active hydrogen-containing group at the end. can.

Examples of the alcohol-modified polysiloxane include compounds represented by each of the following general formulas (13) to (19).

Examples of the mercapto-modified polysiloxane include compounds represented by each of the following general formulas (20) to (23).

The polysiloxane (d) having at least one active hydrogen-containing group listed above is a compound preferably used as a raw material for the polyurethane resin (A), but is not limited to the specific examples listed above. . Therefore, as the polysiloxane (d) having at least one active hydrogen-containing group, in addition to the specific examples listed above, other currently commercially available compounds or compounds that can be easily obtained from the market can be used. It is also possible. Among the polysiloxanes (d) having at least one active hydrogen-containing group, alcohol-modified polysiloxanes are preferred, and alcohol-modified polysiloxanes having two hydroxyl groups are more preferred.

(Polyisocyanate (e))
Polyisocyanate (e) is a compound having two or more isocyanate groups in one molecule. As the polyisocyanate (e), any of those conventionally used in the production of known polyurethanes can be used, and one type or two or more types can be used without particular limitation.

Specific examples of polyisocyanate (e) include tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), diphenylmethane diisocyanate (MDI), 4-methoxy-1,3-phenylene diisocyanate, 4-isopropyl-1,3- phenylene diisocyanate, 4-chloro-1,3-phenylene diisocyanate, 4-butoxy-1,3-phenylene diisocyanate, 2,4-diisocyanate diphenyl ether, 1,5-naphthalene diisocyanate, benzidine diisocyanate, o-nitrobenzidine diisocyanate, and Aromatic diisocyanates such as dibenzyl, 4'-diisocyanate; aliphatic diisocyanates such as methylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), and 1,10-decamethylene diisocyanate; , 4-cyclohexylene diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), 1,5-tetrahydronaphthalene diisocyanate, isophorone diisocyanate, hydrogenated MDI, and hydrogenated XDI; alicyclic diisocyanates; adducts of various diisocyanates; Isocyanate prepolymers such as isocyanurates of various diisocyanates, biurets of HDI, and allophanates of HDI; and various diisocyanates and low molecular weight polyols and/or polyamines are reacted so that the terminals become isocyanates. Examples include prepolymers having isocyanate groups at the terminals.

(Compound (f))
By reacting the above-mentioned compound (a), compound (b), and polyisocyanate (e), and optionally a reaction component containing a chain extender (c) and polysiloxane (d), a compound having an NCO group is produced. A urethane prepolymer can be obtained. This urethane prepolymer having an NCO group and a compound (f) having an amino group and an alkoxysilyl group (herein simply referred to as "compound (f)" or "amino group-containing silane compound (f)") The polyurethane resin (A) can be obtained by reacting with an amine compound containing the following: The amine compound used in this case reacts with the urethane prepolymer having an NCO group as a chain extender (second chain extender). By using at least the compound (f) as the amine compound, an alkoxysilyl group, which is a group that produces a silanol group upon hydrolysis, is introduced into the polyurethane resin (A). In addition, as an amine compound, other amine compounds (for example, the above-mentioned short chain diamine, etc.) may be used together with the amino group-containing silane compound (f).

Examples of the compound (f) include N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane. )-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, and 3-aminopropyltriethoxysilane. It is preferable to use at least one of these. Among these, compound (f) having one primary amino group and one secondary amino group in one molecule is more preferred. Among them, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane and N- (2-aminoethyl)-3-aminopropyltrimethoxysilane is more preferred.

When synthesizing a urethane prepolymer having an NCO group, the molar ratio (a/b) of compound (a) to compound (b) is preferably 0.05 to 2.0.

In addition, when synthesizing a urethane prepolymer having an NCO group, the total active hydrogen content of compound (a) and compound (b), and the chain extender (c) and polysiloxane (d) used as necessary. The equivalent ratio (NCO/active hydrogen) of the isocyanate group of polyisocyanate (e) to the group is preferably 1.1 to 5.0, more preferably 1.1 to 3.0, and 1.2 to 1.8. is even more preferable. By setting the equivalent ratio (NCO/active hydrogen) to 1.1 or more, it becomes possible to form the molecular terminal of the obtained urethane-based prepolymer into an NCO group. Further, by setting the equivalent ratio (NCO/active hydrogen) to 5.0 or less, unreacted polyisocyanate (e) can be prevented from remaining in the reaction system more than necessary. In a preferred embodiment, the equivalent ratio (NCO/active hydrogen) represents the equivalent ratio (NCO/OH) of the isocyanate groups of the polyisocyanate (e) to the total hydroxyl groups of the compounds (a) to (d).

In synthesizing the polyurethane resin (A), the amino groups (primary amino groups and secondary amino groups) of the amine compound containing the amino group-containing silane compound (f) are compared to the NCO groups of the urethane prepolymer having NCO groups. The equivalent ratio (amino group/NCO) is preferably from 0.001 to 1.0, more preferably from 0.01 to 0.6. Further, the amino group-containing silane compound (f) is more preferably used in an amount of 5 to 15% of the actually measured NCO% of the urethane prepolymer having NCO groups.

[Method for producing aqueous dispersion of polyurethane resin (A)]
The aqueous dispersion of polyurethane resin (A) can be produced according to a known method for producing polyurethane resins. For example, first, in the presence of an organic solvent that does not contain active hydrogen in the molecule, or in the absence of an organic solvent, compound (a), compound (b), polyisocyanate (e), and optionally a chain The reaction components containing the extender (c) and the polysiloxane (d) are reacted by a one-shot method or a multi-stage method at 20 to 150°C, preferably 60 to 110°C, until the reaction product is, for example, % theoretical NCO. In this way, a urethane prepolymer having NCO groups is obtained. The mixing ratio of the above reaction components may be such that a urethane prepolymer having an NCO group at the end is formed. In one embodiment, compound (a) is preferably 0.1 to 30% by mass, more preferably 5 to 20% by mass, and compound (b) is preferably may be 20 to 90% by weight, more preferably 50 to 85% by weight, and polysiloxane (d) may be preferably 0.01 to 50% by weight, more preferably 1 to 20% by weight.

Next, the obtained urethane prepolymer having NCO groups is emulsified with water and a neutralizing agent, and then the amino group-containing silane compound (f) and other amine compounds are added as necessary to form the urethane prepolymer having NCO groups. A chain prepolymer is subjected to a chain extension reaction to generate urea bonds. Thereafter, after removing the solvent as necessary, an aqueous dispersion of the polyurethane resin (A) can be obtained. Further, as will be described later, after the chain elongation reaction to generate the above-mentioned urea bond, a quaternary ammonium salt-containing silane compound (B), which is an antibacterial agent, may be further added to perform hydrolysis and condensation reactions.

The weight average molecular weight (Mw) of the polyurethane resin (A) obtained as described above is 1,000 to 500,000, since properties such as flexibility, adhesiveness, and abrasion resistance are more effective. This is preferable because it is more likely to be exhibited.

Further, in the synthesis of the polyurethane resin (A) as described above, a catalyst can be used as necessary. Examples of catalysts include salts of metals and organic and inorganic acids such as dibutyltin laurate, dioctyltin laurate, stannath octoate, zinc octylate, and tetra-n-butyl titanate, as well as organometallic derivatives and organic and inorganic acids such as triethylamine. Examples include amines and diazabicycloundecene catalysts.

Furthermore, as described above, the polyurethane resin (A) may be synthesized without a solvent, or may be synthesized using an organic solvent if necessary. Suitable organic solvents include those that are inert to isocyanate groups or less active than the reactants. For example, ketone solvents (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), aromatic hydrocarbon solvents (toluene, xylene, Swazol (aromatic hydrocarbon solvent manufactured by Cosmo Oil Co., Ltd.), Solvesso (Exxon Chemical Co., Ltd.) Company-manufactured aromatic hydrocarbon solvents), aliphatic hydrocarbon solvents (n-hexane, etc.), alcohol solvents (methanol, ethanol, isopropanol, etc.), ether solvents (dioxane, tetrahydrofuran, etc.), ester solvents Solvents (ethyl acetate, butyl acetate, isobutyl acetate, etc.), glycol ether ester solvents (ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, 3-methyl-3-methoxybutyl acetate, ethyl-3-ethoxypropionate, etc.) ), amide solvents (dimethylformamide, dimethylacetamide, etc.), and lactam solvents (n-methyl-2-pyrrolidone, etc.). Among these, methyl ethyl ketone, ethyl acetate, acetone, and tetrahydrofuran are preferred in consideration of solvent recovery, solubility during urethane synthesis, reactivity, boiling point, and emulsification dispersibility in water.

[Antibacterial agent]
The paint of this embodiment contains a silane compound (B) having a quaternary ammonium salt structure and a silanol group as an antibacterial agent. The paint may contain an antibacterial agent other than the quaternary ammonium salt-containing silane compound (B) as long as the object of the present invention is not impaired.

In one embodiment of the coating material, the quaternary ammonium salt-containing silane compound (B) can be contained in a chemically unbonded state (unreacted state) with the above-mentioned polyurethane resin (A). In this case, the polyurethane resin (A) and the quaternary ammonium salt-containing silane compound (B) both have silanol groups, so when forming a coating film containing them separately (for example, when applying the coating material) during drying), it is possible to subject them to a condensation reaction. Further, in one embodiment of the paint, the quaternary ammonium salt-containing silane compound (B) and the polyurethane resin (A) are contained in a chemically bonded state as a condensation reaction product due to the silanol groups they have. I can do it. In this way, since the polyurethane resin (A) and the quaternary ammonium salt-containing silane compound (B) can be condensed in advance or during coating film formation, the quaternary ammonium salt-containing antibacterial agent can be used in the coating film. The silane compound (B) can be immobilized on the polyurethane resin (A). As a result, the coating film can be expected to have abrasion resistance comparable to that of a coating that does not contain an antibacterial agent, and as a result, long-lasting antibacterial properties can also be expected. Note that an embodiment in which the polyurethane resin (A) and the compound (B) are condensed during coating film formation is easier to manufacture and has better storage stability than an embodiment in which they are contained in a chemically bonded state. It is preferable from the viewpoint of properties (maintenance of dispersibility of the matting agent when prepared as a matting paint), etc.

Since the paint of this embodiment contains the aqueous dispersion of the above-mentioned polyurethane resin (A), in this specification, the silanol group possessed by the quaternary ammonium salt-containing silane compound (B) is A group that produces a silanol group is also included. If we distinguish between a silanol group (-SiOH) and a group that generates a silanol group (-SiOH) by hydrolysis, the quaternary ammonium salt-containing silane compound (B) has a silanol group and a group that generates a silanol group (-SiOH) by hydrolysis. It suffices if it has at least one of the groups that give rise to.

Groups that produce silanol groups upon hydrolysis include groups bonded to silicon atoms, such as alkoxy groups, acyloxy groups, alkenyloxy groups, and alkoxy-substituted alkoxy groups. Among these, an alkoxy group bonded to a silicon atom (alkoxysilyl group including a silicon atom) is preferred. The number of carbon atoms in the alkoxy group is preferably 1 to 4, more preferably 1 to 3. Preferred alkoxy groups include methoxy, ethoxy, n-propoxy, and isopropoxy groups.

The quaternary ammonium salt structure in the quaternary ammonium salt-containing silane compound (B) has a structure in which 3 or 4 hydrocarbon groups (alkyl group, alkylene group, etc.) are bonded to a quaternary ammonium cation. preferable. More preferably, the total number of carbon atoms in the hydrocarbon groups bonded to the quaternary ammonium cation is 1 to 30.

The quaternary ammonium salt-containing silane compound (B) preferably has a siloxane bond (-Si-O-Si-) containing a silicon atom in a silanol group (-SiOH). The number of quaternary ammonium salt structures in one molecule of the quaternary ammonium salt-containing silane compound (B) is preferably one or two. Further, the number of silanol groups in one molecule of the quaternary ammonium salt-containing silane compound (B) is preferably 1 to 4, more preferably 2 to 4, and even more preferably 3 or 4. preferable.

As the quaternary ammonium salt-containing silane compound (B), commercially available products can be used because they are easily available. For example, as a commercially available quaternary ammonium salt-containing silane compound (B) that has a siloxane bond, two quaternary ammonium salt structures (quaternary ammonium cations), and four silanol groups in one molecule. Examples include the trade names "X-12-1126" and "X-12-1139" (both manufactured by Shin-Etsu Chemical Co., Ltd.). Also, for example, a quaternary ammonium salt-containing silane compound having one quaternary ammonium salt structure (quaternary ammonium cation) and three alkoxy groups (groups that produce silanol groups upon hydrolysis) in one molecule. Commercial products of (B) include the product name "KBM-9418-40" (manufactured by Shin-Etsu Chemical Co., Ltd.), the product name "Niccanon RB-40" (manufactured by NICCA Chemical Co., Ltd.), and the product name "SANITIZED T99-". 19'' (manufactured by SANITIZED AG).

The content of the quaternary ammonium salt-containing silane compound (B) is preferably 0.1 to 20 parts by mass, and preferably 0.5 to 15 parts by mass, based on 100 parts by mass of the polyurethane resin (A). It is more preferable that the amount is 1 to 10 parts by mass.

[Crosslinking agent]
It is preferable that the coating material of this embodiment further contains a crosslinking agent. The crosslinking agent is at least one selected from the group consisting of isocyanate crosslinking agents (including block type isocyanate crosslinking agents), carbodiimide crosslinking agents, oxazoline crosslinking agents, epoxy crosslinking agents, and metal complex crosslinking agents. It is more preferable to include seeds. Among these, crosslinking agents that can react with carboxy groups and/or silanol groups present in the molecules of the polyurethane resin (A), silanol groups and/or quaternary ammonium cations present in antibacterial agents, etc. are preferred, such as , carbodiimide-based crosslinking agents are more preferred.

As the crosslinking agent, it is preferable to use a commercially available product from the viewpoint of easy availability. Examples of commercially available isocyanate-based crosslinking agents include the "Duranate" series (manufactured by Asahi Kasei Corporation) under the trade name and the "Aquanate" series (manufactured by Tosoh Corporation) under the trade name. Examples of commercially available epoxy crosslinking agents include the "jER Cure" series (manufactured by Mitsubishi Chemical Corporation) under the trade name. Examples of commercially available carbodiimide crosslinking agents include the "Carbodilite" series (manufactured by Nisshinbo Chemical Co., Ltd.) under the trade name. Examples of commercially available oxazoline crosslinking agents include the "Epocross" series (manufactured by Nippon Shokubai Co., Ltd.) under the trade name. Commercially available metal complex crosslinking agents include, for example, organic titanium chelate compounds under the trade name "ORGATIX TC" series, organic zirconium chelate compounds under the trade name "ORGATIX ZC" series, and organic aluminum chelate compounds. Product name: "Orgatics Al" series (manufactured by Matsumoto Fine Chemicals Co., Ltd.), and product name: "Nasem" series, which is an acetylacetone metal complex of metals such as aluminum, chromium, cobalt, copper, iron, nickel, vanadium, and zinc. (manufactured by Nippon Kagaku Sangyo Co., Ltd.).

Using an appropriate amount of a crosslinking agent is effective in improving the durability, heat resistance, light resistance, etc. of the coating film. From this point of view, the content of the crosslinking agent in the paint is preferably 40 parts by mass or less, and 0.5 to 30 parts by mass, in terms of solid content, based on 100 parts by mass of the polyurethane resin (A). The amount is more preferably 0.5 to 20 parts by mass.

[Flatting agent]
The paint of this embodiment may further contain a matting agent. It is possible to prepare matte paints by including a matting agent. As the matting agent, both organic particles and inorganic particles can be used. Specific examples of the matting agent include silica particles, silicone resin particles, fluororesin particles, acrylic resin particles, polyurethane gel particles, silicone-modified polyurethane gel particles, polyethylene particles, and reactive siloxanes. One or more of these can be used. Furthermore, when a matting agent is used, a dispersing agent for dispersing the matting agent may be used in combination.

It is preferable that the paint of this embodiment contains at least one kind of matting agent selected from the group consisting of polyurethane gel particles and silica particles, and as the matting agent, it contains both polyurethane gel particles and silica particles. It is more preferable. By using this specific matting agent in combination with the specific antibacterial agent mentioned above, properties required for water-based matting paints (such as dispersibility, anti-settling properties, matting properties (60° gloss value), This makes it easier to obtain a matte paint that has good adhesion to substrates, vacuum formability, stain resistance, abrasion resistance, bending resistance, light resistance, heat resistance, etc.).

(Polyurethane gel particles)
Polyurethane gel particles can be easily obtained by emulsion polymerization or the like, and commercially available products can also be used. Examples of commercially available polyurethane gel particles include the product name "Art Pearl" (manufactured by Negami Kogyo Co., Ltd.). The polyurethane gel particles are preferably spherical and have a volume average particle diameter of about 0.1 to 30.0 μm. The volume average particle diameter in this specification can be determined from a 50% cumulative average value measured using a dynamic light scattering particle size distribution analyzer (trade name "Microtrac UPA", manufactured by Nikkiso Co., Ltd.).

The content of the polyurethane gel particles is preferably 3 to 100 parts by mass, more preferably 10 to 90 parts by mass, and 20 to 80 parts by mass based on 100 parts by mass of the polyurethane resin (A). It is even more preferable that there be.

(Silica particles)
Both natural and synthetic silica particles can be used. Examples of synthetic silica particles include precipitated silica, gel silica, and dry silica. Among these, precipitated silica and dry silica are preferred. If the volume average particle diameter of the silica particles is about 0.5 to 15.0 μm, porous particles having irregular shapes or irregular surfaces can be used. By using such silica particles, they easily react with the silanol groups present in the molecules of the polyurethane resin (A), so it is possible to form a coating film with further improved durability.

The content of silica particles is preferably 0.5 to 20 parts by weight, more preferably 1 to 15 parts by weight, and 2 to 10 parts by weight based on 100 parts by weight of the polyurethane resin (A). It is more preferable that

[Liquid medium]
The paint of this embodiment contains water because it contains the aqueous dispersion of the polyurethane resin described above, and therefore can be prepared as an aqueous paint. As water, it is preferable to use ion-exchanged water. Furthermore, the paint can contain a liquid medium other than water, if necessary. As the liquid medium, a water-soluble organic solvent is preferred. Examples of water-soluble organic solvents include methanol, ethanol, 1-propanol, isopropanol, ethylene glycol, propylene glycol, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, and diethylene glycol dimethyl ether. , and diethylene glycol diethyl ether. One or more water-soluble organic solvents can be used.

The content of the liquid medium containing water and a water-soluble organic solvent in the paint is preferably 5 to 99% by mass, more preferably 30 to 90% by mass, even more preferably 40% by mass, based on the total mass of the paint. ~90% by mass. On the other hand, the solid content concentration of the paint is preferably 1 to 95% by weight, more preferably 10 to 70% by weight, and even more preferably 10 to 60% by weight, based on the total weight of the paint.

[Other additives]
The coating material may contain conventionally known resins and various additives as long as they do not impede the object of the present invention. Additives include antioxidants (hindered phenol type, phosphite type, thioether type, etc.), light stabilizers (hindered amine type, etc.), ultraviolet absorbers (benzophenone type, benzotriazole type, etc.), gas discoloration stabilizers ( hydrazine-based, etc.), hydrolysis inhibitors (carbodiimide, etc.), metal deactivators (hydrazine-based, etc.), fungicides, preservatives, flame retardants, lubricants, slip agents, leveling agents, thickeners, antifoaming agents, Examples include dispersants, emulsifiers, surfactants, pigments, and colorants. One or more types of additives can be used.

<Paint manufacturing method>
The paint of this embodiment includes an aqueous dispersion of a polyurethane resin (A), a quaternary ammonium salt-containing silane compound (B), a crosslinking agent, and, if necessary, the above-mentioned matting agent, liquid medium, and others. It can be manufactured by mixing additives etc. in water. The content of the polyurethane resin (A) is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, and 20 to 40% by mass based on the mass of the solid content of the paint. It is even more preferable that there be. The content of the quaternary ammonium salt-containing silane compound (B) is preferably 0.5 to 20% by mass, more preferably 0.5 to 15% by mass, based on the mass of the solid content of the paint. The amount is more preferably 1 to 10% by mass. The content of the crosslinking agent is preferably 0.1 to 40% by mass, more preferably 0.5 to 30% by mass, and 1 to 20% by mass based on the mass of the solid content of the paint. It is even more preferable that there be.

When carrying out the process from manufacturing an aqueous dispersion of polyurethane resin (A) to manufacturing a paint, first, as explained in the above "Method for manufacturing an aqueous dispersion of polyurethane resin (A)", the polyurethane resin is A urethane prepolymer having NCO groups, which is a precursor of (A), is produced. Then, the precursor of the polyurethane resin (A) (urethane prepolymer having an NCO group) is subjected to a chain extension reaction with an amine compound containing a compound (f) having an amino group and an alkoxysilyl group to form a silanol group. A polyurethane resin (A) having the following properties is obtained. Next, adding a silane compound (B) having a quaternary ammonium salt structure and a silanol group to the aqueous dispersion of the polyurethane resin (A); and crosslinking the aqueous dispersion of the polyurethane resin (A). A coating material can be manufactured by adding an agent.

Furthermore, in one embodiment, the quaternary ammonium salt-containing silane compound (B) is added to the aqueous dispersion of the polyurethane resin (A), so that the polyurethane resin (A) and the silane compound (B) are combined. It is also preferable to carry out a condensation reaction using the silanol groups that the silanol groups have to form a chemical bond. Specifically, the quaternary ammonium salt-containing silane compound (B) is added to an aqueous dispersion of the polyurethane resin (A), and the mixture is heated at 50 to 70°C for 0.5 to 2 hours in a pH range of 7 to 11. Hydrolysis and dehydration condensation reactions may be carried out as needed.

<Example of paint usage>
The material of the object to which the paint of this embodiment is applied is not particularly limited, and includes, for example, plastic, concrete, metal, paper, and cloth such as woven fabric and nonwoven fabric. Among these, plastic is preferred.

Examples of plastics to which the paint is applied include olefin resins (polyethylene, polypropylene, etc.), ethylene propylene diene resins, styrene acrylonitrile resins, polysulfone resins, polyphenylene ether resins, acrylic resins, and silicones. resins, fluorine resins, polyester resins, polyamide resins, polyimide resins, polystyrene resins, polyurethane resins, polycarbonate resins, norbornene resins, cellulose resins, polyvinyl alcohol resins, polyvinyl formal resins, polyvinyl Butyral resin, polyvinylpyrrolidone resin, polyvinyl acetate resin, polyvinyl acetal resin, polyvinyl chloride, engineering plastic, biodegradable plastic, thermoplastic olefin elastomer (TPO), thermoplastic styrene elastomer (TPS), Examples include polyester thermoplastic elastomer (TPEE). The plastic object may be a plastic molded product having a shape corresponding to various product shapes, or may be a plastic film or a plastic sheet.

After applying a paint to the above-mentioned plastic so that the film thickness after drying is 5 to 25 μm, heat treatment is performed at 100 to 120°C for 20 minutes or at 150 to 180°C for 5 to 10 minutes. , can form a coating film. For example, when manufacturing vehicle interior materials (instrument panels, door trims, console boxes, etc.), a two-component water-based urethane resin is coated on a TPO base sheet, and then For example, a method is used in which the paint according to an embodiment of the present invention is applied by spray painting or gravure coating to form a coating film, and then vacuum forming is performed.

It is also useful for a method in which the paint of this embodiment is directly applied to a plastic molded product, and a mold forming method in which polypropylene, urethane resin, etc. is placed in a mold after spray coating the paint of this embodiment on a mold. It is. In addition, when applying the paint of this embodiment to a plastic molded product with poor adhesiveness, it is preferable to perform a primer treatment on the surface of the plastic molded product in advance.

As described in detail above, the paint and the method for manufacturing the same according to one embodiment of the present invention can have the following configuration.
[1] Contains an aqueous dispersion of polyurethane resin and an antibacterial agent,
The polyurethane resin includes a polyurethane resin (A) having a silanol group,
The antibacterial agent is a paint containing a silane compound (B) having a quaternary ammonium salt structure and a silanol group.
[2] The coating material according to [1] above, wherein the silane compound (B) is contained in the polyurethane resin (A) in a chemically unbonded state.
[3] The silane compound (B) is chemically added to the polyurethane resin (A) as a condensation reaction product of the silanol group possessed by the silane compound (B) and the silanol group possessed by the polyurethane resin (A). The paint according to the above [1], wherein the paint is contained in a state of being bound together.
[4] The polyurethane resin (A) is a reaction product of a urethane prepolymer having an isocyanate group and an amine compound,
The urethane prepolymer contains a compound (a) having an anionic hydrophilic group other than a hydroxyl group and an active hydrogen-containing group other than the anionic hydrophilic group, and at least one member selected from the group consisting of polyols and polyamines. A reaction product of a reaction component containing a compound (b) and a polyisocyanate (e),
The paint according to any one of [1] to [3] above, wherein the amine compound contains a compound (f) having an amino group and an alkoxysilyl group.
[5] The urethane prepolymer contains the compound (a), the polycarbonate polyol (b1), the chain extender (c), the polysiloxane (d) having an active hydrogen-containing group, and the polyisocyanate (e). ) The paint according to the above [4], which is a reaction product with.
[6] The compound (f) is N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, The paint according to [4] or [5] above, containing at least one member selected from the group consisting of ethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, and 3-aminopropyltriethoxysilane. .
[7] It further contains a crosslinking agent, and the crosslinking agent is at least one selected from the group consisting of isocyanate crosslinking agents, carbodiimide crosslinking agents, oxazoline crosslinking agents, epoxy crosslinking agents, and metal complex crosslinking agents. The paint according to any one of [1] to [6] above.
[8] The paint according to any one of [1] to [7] above, further containing at least one matting agent selected from the group consisting of polyurethane gel particles and silica particles.
[9] The method for producing the paint according to any one of [1] to [8] above,
subjecting the precursor of the polyurethane resin (A) to a chain extension reaction with an amine compound containing a compound (f) having an amino group and an alkoxysilyl group to obtain the polyurethane resin (A) having the silanol group; and adding the silane compound (B) to the aqueous dispersion of the polyurethane resin (A).
[10] The silane compound (B) is added to the aqueous dispersion of the polyurethane resin (A), and the polyurethane resin (A) and the silane compound (B) are condensed with the silanol groups they have. The method for producing a paint according to the above [9], which includes reacting and chemically bonding.

EXAMPLES Hereinafter, a paint according to an embodiment of the present invention will be specifically described based on Examples, but the present invention is not limited to the following Examples. In addition, "part" in the following text indicates parts by mass, and "%" indicates mass %.

<Production of water dispersion of polyurethane resin>
(Manufacturing example 1: PUD-1)
After purging the reaction vessel equipped with a stirrer, reflux condenser, thermometer, nitrogen blowing tube, and manhole with nitrogen gas, 10.0 parts of dimethylolpropionic acid was added as compound (a), and polycarbonate diol was added as compound (b). (polyhexamethylene carbonate diol; number average molecular weight 2,000; trade name "Plaxel CD220", manufactured by Daicel Corporation) 100.0 parts, 1,3-butanediol as chain extender (c) 2.0 parts, poly 10.0 parts of alcohol-modified polysiloxane (number average molecular weight 1,900) represented by the following formula (15-1) as siloxane (d) and 120.0 parts of acetone were added and uniformly dissolved.
Subsequently, 51.0 parts of hexamethylene diisocyanate (HDI) was used as polyisocyanate (e) (the equivalent ratio of NCO groups in polyisocyanate (e) to the total hydroxyl groups in (a) to (d) above (NCO/OH ) was added, and the reaction was carried out at 80° C. until the NCO content became 100% with respect to the active hydrogen groups, thereby obtaining a urethane prepolymer having NCO groups.
Thereafter, the system was cooled to 50°C, and 440.0 parts of ion-exchanged water and 7.5 parts of triethylamine as a neutralizing agent (amount equivalent to the anionic hydrophilic group (-COOH)) were added to homogenize the system. emulsified into. Next, 15.2 parts of ethylenediamine (an amount equivalent to the measured NCO%) was added as an amine compound, and a chain extension reaction was performed on the urethane prepolymer having NCO groups. Finally, the acetone in the system was vacuum degassed and recovered.
In this way, an aqueous dispersion of polyurethane resin PUD-1 having a nonvolatile content (solid content) concentration of 30% was obtained.

(Manufacturing example 2: PUD-2)
After purging the reaction vessel equipped with a stirrer, reflux condenser, thermometer, nitrogen blowing tube, and manhole with nitrogen gas, 10.0 parts of dimethylolpropionic acid was added as compound (a), and polyhexane was added as compound (b). 100.0 parts of methylene carbonate diol (number average molecular weight 2,000; trade name "Plaxel CD220", manufactured by Daicel Corporation), 2.0 parts of 1,3-butanediol as a chain extender (c), polysiloxane (d ) and 10.0 parts of alcohol-modified polysiloxane (number average molecular weight 1,900) represented by the above formula (15-1) and 120.0 parts of acetone were added and uniformly dissolved.
Subsequently, 51.0 parts of hexamethylene diisocyanate (HDI) was used as polyisocyanate (e) (the equivalent ratio of NCO groups in polyisocyanate (e) to the total hydroxyl groups in (a) to (d) above (NCO/OH ) was added, and the reaction was carried out at 80° C. until the NCO content became 100% with respect to the active hydrogen groups, thereby obtaining a urethane prepolymer having NCO groups.
After that, the system was cooled to 50°C, and 450.0 parts of ion-exchanged water and 7.5 parts of triethylamine as a neutralizing agent (amount equivalent to the anionic hydrophilic group (-COOH)) were added to homogenize the system. emulsified into. Next, 13.7 parts of ethylenediamine (the amount corresponding to 90% of the actually measured NCO%) was used as the amine compound, and 5.6 parts of N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane (the amount corresponding to 90% of the actually measured NCO%) was added as the compound (f). %) was added to perform a chain elongation reaction. Finally, the acetone in the system was vacuum degassed and recovered.
In this way, an aqueous dispersion PUD-2 of polyurethane resin (A) having a nonvolatile content (solid content) concentration of 30% was obtained.

(Manufacturing example 3: PUD-3)
After purging the reaction vessel equipped with a stirrer, reflux condenser, thermometer, nitrogen blowing tube, and manhole with nitrogen gas, 10.0 parts of dimethylolpropionic acid was added as compound (a), and polyhexane was added as compound (b). 100.0 parts of methylene carbonate diol (number average molecular weight 2,000; trade name "Plaxel CD220", manufactured by Daicel Corporation), 2.0 parts of 1,3-butanediol as a chain extender (c), polysiloxane (d ) and 10.0 parts of alcohol-modified polysiloxane (number average molecular weight 1,900) represented by the above formula (15-1) and 120.0 parts of acetone were added and uniformly dissolved.
Subsequently, 51.0 parts of hexamethylene diisocyanate (HDI) was used as polyisocyanate (e) (the equivalent ratio of NCO groups in polyisocyanate (e) to the total hydroxyl groups in (a) to (d) above (NCO/OH ) was added, and the reaction was carried out at 80° C. until the NCO content became 100% with respect to the active hydrogen groups, thereby obtaining a urethane prepolymer having NCO groups.
Thereafter, the system was cooled to 50°C, and 480.0 parts of ion-exchanged water and 7.5 parts of triethylamine as a neutralizing agent (an amount equivalent to the anionic hydrophilic group (-COOH)) were added to cool the system. It was emulsified uniformly. Next, 13.7 parts of ethylenediamine (the amount corresponding to 90% of the actually measured NCO%) was used as the amine compound, and 5.6 parts of N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane (the amount corresponding to 90% of the actually measured NCO%) was added as the compound (f). %) was added to perform a chain elongation reaction. Then, as antibacterial agent 1, a predetermined amount (5% amount based on solid content) of a quaternary ammonium salt-containing silane compound (B1) (trade name "X-12-1139", manufactured by Shin-Etsu Chemical Co., Ltd.) was added. Hydrolysis and dehydration condensation reactions were carried out under conditions of pH 7 to 11, 60° C., and 1 hour. Finally, the acetone in the system was vacuum degassed and recovered.
In this way, a polyurethane resin containing a polyurethane resin (A) and a quaternary ammonium salt-containing silane compound (B1) in a chemically bonded state has a nonvolatile content (solid content) concentration of 30%. Aqueous dispersion PUD-3 of (A) was obtained.

Table 1 summarizes the manufacturing conditions for the polyurethane resin aqueous dispersions PUD1-3 of Production Examples 1-3 above.

<Manufacture of paint>
(Examples 1 to 6, Comparative Examples 1 to 3)
Each component (unit: part) shown in the upper row of Table 2 (Table 2-1 and Table 2-2) was mixed to prepare a matte paint for each Example and Comparative Example. Note that the amounts of antibacterial agents 1 to 4 shown in Table 2 represent the amounts in terms of active ingredients (solid content). Furthermore, the antibacterial agents 1 to 4, matting agents 1 and 2, and crosslinking agents shown in Table 2 are as follows.

・Antibacterial agent 1: Quaternary ammonium salt-containing silane compound (B1) (trade name "X-12-1139", manufactured by Shin-Etsu Chemical Co., Ltd.; active ingredient (silane compound having two dimethyloctadecyl ammonium chloride structures) concentration 30% liquid)
・Antibacterial agent 2: Quaternary ammonium salt-containing silane compound (B2) (trade name "Nikkanon RB-40", manufactured by NICCA CHEMICAL CO., LTD.; active ingredient (trimethoxysilane compound with quaternary ammonium salt added) concentration 40% liquid)
・Antibacterial agent 3: Quaternary ammonium salt-containing silane compound (B3) (trade name "Sanitized T99-19", manufactured by SANITIZED AG; active ingredient (tetradecyl[3-(trimethoxysilyl)propyl]dimethylaminium chloride) liquid with a concentration of 40%)
・Antibacterial agent 4: Silver-based inorganic antibacterial agent (trade name "Million Guard PG711", manufactured by Koa Glass Co., Ltd.; active ingredient (silver-containing phosphate glass powder) powder with a concentration of 97% or more)
- Matting agent 1: Polyurethane gel particles (trade name "Art Pearl C-800 Transparent", manufactured by Negami Kogyo Co., Ltd.; volume average particle diameter 6 μm, white powder with Tg -13°C)
- Matting agent 2: Silica particles (trade name "ACEMATT TS-100", manufactured by EVONIK; dry silica with a volume average particle diameter of 9.5 μm)
・Crosslinking agent: Carbodiimide crosslinking agent (trade name "Carbodilite V-04", manufactured by Nisshinbo Chemical Co., Ltd.; active ingredient (non-volatile content: aqueous crosslinking agent made by adding a hydrophilic segment to polycarbodiimide resin) aqueous with a concentration of 40% liquid)

<Paint evaluation>
[Paint suitability]
The paints produced in each Example and Comparative Example were evaluated for dispersibility, sedimentation, storage stability, and applicability as described below.

(dispersibility)
The paint immediately after preparation was visually observed, and the dispersibility (degree of aggregation) of the polyurethane resin and matting agent was evaluated according to the following evaluation criteria.
A: Almost uniformly dispersed without any problem.
B: Slight coarse particles are observed.
C: Coarse particles are confirmed.

(sedimentation)
The paint was visually observed 6 hours after preparation, and the settling properties of the polyurethane resin and matting agent were evaluated according to the following evaluation criteria.
A: There was no problem, and almost no sediment was observed.
B: A slight amount of sediment is observed.
C: Sediment is confirmed.

(Storage stability)
The prepared paint was left standing at room temperature (23° C.) for 3 months and then visually observed, and the degree of aggregation and sedimentation of the polyurethane resin and matting agent were evaluated according to the following evaluation criteria.
A: No precipitate is formed, or the precipitate can be easily subdivided.
B: Part of the material solidified on the bottom and it is difficult to redisperse it.
C: The entire precipitate solidifies and does not redisperse.

(Applicability)
The prepared paint was applied to hiding rate measuring paper (trade name "LENETA N2C-2", manufactured by Leneta Company, Inc.) using a bar coater, and evaluated according to the following evaluation criteria.
A: It was applied without any problem.
B: Slight surface unevenness is observed.
C: Surface unevenness is observed.

<Preparation and evaluation of coating film>
The paints produced in each example and comparative example were applied to each base sheet used in the evaluation described below using a bar coater, dried at 100°C for 2 minutes, and then aged at 50°C for 24 hours to increase the thickness. A coating film with a thickness of about 9 μm was formed. The coating film was subjected to the following tests and evaluations. The results of each evaluation are shown in the lower part of Table 2.

[Antibacterial]
Using a test piece (painted test piece) in which a coating film was provided on a PET film (product name "Lumirror S10", manufactured by Toray Industries, Inc.) as a base sheet, the coating film of the test piece was tested according to JIS Z2801:2010 (ISO 22196:2007), an antibacterial test was conducted. Specifically, the test was conducted according to the following steps.
(1) 0.4 mL of bacterial liquid was dropped onto the coated side of a 5 cm square test piece and covered with a 4 cm square film. As a blank test piece, a test piece (non-painted test piece) having only a base material (PET film) without a coating film was subjected to the same procedure. Escherichia coli and Staphylococcus aureus were used as the bacterial solution.
(2) The test piece was cultured for 24 hours at a temperature of 35±1°C and a relative humidity of 90% or higher.
(3) After the specimen was allowed to stand, the test bacteria on the test piece were washed out and collected, and the number of viable bacteria per 1 cm ² was measured.
(4) Antibacterial activity value R was calculated using the following formula. The larger the antibacterial activity value R, the higher the antibacterial property.
R=U _t -A _t
U _t : Average value of the logarithm of the number of viable bacteria per 1 cm ² of the blank test piece after 24 hours A _t : Average value of the log value of the number of viable bacteria per 1 cm ² of the test piece (painted test piece) after 24 hours Average value

[Matte]
The gloss value (60° incident light/60° reflected light) of the coating film provided on the base sheet shown below was measured using a direct reading haze computer HGM-2DP (manufactured by Suga Test Instruments Co., Ltd.).
・TPO (olefin thermoplastic elastomer)
・PVC black (black polyvinyl chloride)
・PVC light color (light color polyvinyl chloride)
・PU synthetic leather (polyurethane synthetic leather)

[Abrasion resistance]
The coating film provided on the above-mentioned "PU synthetic leather" as a base sheet was abraded using a Gakushin type abrasion tester under the conditions of No. 6 canvas and a load of 1 kg, and the coating film surface was removed every 100 times of abrasion. The number of wears until the appearance changed was measured by visual observation. Two measurements were taken for each test piece, and the average value was taken.

[Bending resistance]
A test piece in which a coating film was provided on the above-mentioned "PVC black" as a base sheet was subjected to a cold resistance flexibility test under the following conditions, and the condition of the coating film surface was evaluated by visually observing.
・Equipment: Dematcher bending tester with low temperature chamber (manufactured by Yasuda Seiki Seisakusho Co., Ltd.)
・Size of test piece: 150mm x 50mm
・Evaluation range: 100mm x 50mm
・Test conditions: -10℃ condition / 72 to 108% bending / 30,000 times ・Evaluation criteria:
○: No cracks.
×: Cracks occur.

[Light resistance]
For each coating film provided on the base sheet "TPO", "PVC black", and "PU synthetic leather", changes in the appearance of the coating film were confirmed using a xenon lamp type light resistance tester, and the following tests were conducted. The light resistance of the coating film was evaluated according to evaluation criteria. When the base sheet was TPO and PU synthetic leather, the irradiation amount was 300 Mj, and when the base sheet was PVC black, the irradiation amount was 200 Mj.
○: No change.
×: Whitening occurred.

[Stain resistance]
Add 1 g of coffee liquid (a solution prepared by dissolving 1 g of instant coffee powder (product name "Nescafé", manufactured by Nestlé Japan Co., Ltd.) in 100 mL of water) on the coating film provided on the above "PVC light color" as a base sheet, or By dropping 1 g of mustard (trade name "French's mustard", manufactured by HEINZ) and wiping it off with ion-exchanged water after 24 hours, observing changes in the appearance of the paint film, the paint film was evaluated according to the following evaluation criteria. The stain resistance was evaluated.
○: No change.
×: There is dirt.

The paints of Examples 1 to 6 show good paint suitability to the same extent as the paint of Comparative Example 1 (paint containing no antibacterial agent) and are capable of forming a paint film with good antibacterial properties. This was recognized. On the other hand, the paint of Comparative Example 2 (paint containing a silver-based inorganic antibacterial agent) had antibacterial properties, but was poor in dispersibility and sedimentation.

Moreover, the paint of Comparative Example 3 did not exhibit antibacterial properties. This is considered to be because the polyurethane resin in PUD-1 used in the paint of Comparative Example 3 does not have silanol groups. That is, in the paint of Comparative Example 3, there was no condensation reaction between the polyurethane resin and the antibacterial agent (silane compound (B1) containing a quaternary ammonium salt) both in the paint and during coating film formation, and the antibacterial agent This is thought to be because it is not fixed in the system resin. On the other hand, since the polyurethane resin (A) in PUD-2 used in the paints of Examples 1 to 5 has silanol groups, when forming the coating film, the polyurethane resin (A) and the antibacterial agent (fourth It is thought that a condensation reaction occurred between the silane compounds (B1), (B2), and (B3) containing class ammonium salts. It is considered that this caused the antibacterial agent to be immobilized on the polyurethane resin (A), so that a coating film with good antibacterial properties was formed. In addition, in the paint of Example 6, the polyurethane resin (A) and the antibacterial agent (the quaternary ammonium salt-containing silane compound (B1)) in PUD-3 were used as condensation reaction products by the silanol groups they each had. It is thought that because it was contained in a chemically bonded state, a coating film with good antibacterial properties was formed.

In addition, a predetermined adhesion test (test under the conditions of lamination at 120° C./10 kg/1 minute) was conducted on a test piece in which a coating film was provided on “TPO” as a base sheet. As a result, the paints of Examples 1, 2, and 6 using antibacterial agent 1 (silane compound containing a quaternary ammonium salt (B1)) were as good as the paint of Comparative Example 1, which did not contain an antibacterial agent. It was confirmed that it was possible to form a coating film with adhesive properties.

Further, a predetermined heat resistance test (test under the conditions of 120° C./400 hours) was conducted on a test piece in which a coating film was provided on “PVC light color” as a base material sheet. As a result, the paints of Examples 1 to 3 and 6 using antibacterial agent 1 (silane compound containing quaternary ammonium salt (B1)) were as good as the paint of comparative example 1 which did not contain antibacterial agent. It was confirmed that it was possible to form a heat-resistant coating film.

Furthermore, a predetermined vacuum formability test (test under conditions of surface temperature of 160 to 170°C) was conducted on a test piece in which a coating film was provided on "TPO" as a base sheet. As a result, the coating film of Example 4 using antibacterial agent 2 (silane compound containing quaternary ammonium salt (B2)) and the coating film of Example 4 using antibacterial agent 3 (silane compound containing quaternary ammonium salt (B3)) were found. It was observed that the coating film of Example 5 exhibited superior moldability compared to the coating film of Comparative Example 1 which did not contain an antibacterial agent.

Claims (10)

Contains an aqueous dispersion of polyurethane resin and an antibacterial agent,
The polyurethane resin includes a polyurethane resin (A) having a silanol group,
The antibacterial agent is a paint containing a silane compound (B) having a quaternary ammonium salt structure and a silanol group. The paint according to claim 1, wherein the silane compound (B) is contained in the polyurethane resin (A) in a chemically unbonded state. The silane compound (B) is chemically bonded to the polyurethane resin (A) as a condensation reaction product of the silanol group possessed by the silane compound (B) and the silanol group possessed by the polyurethane resin (A). The coating material according to claim 1, wherein the coating material is contained in a state where the coating material is The polyurethane resin (A) is a reaction product of a urethane prepolymer having an isocyanate group and an amine compound,
The urethane prepolymer contains a compound (a) having an anionic hydrophilic group other than a hydroxyl group and an active hydrogen-containing group other than the anionic hydrophilic group, and at least one member selected from the group consisting of polyols and polyamines. A reaction product of a reaction component containing a compound (b) and a polyisocyanate (e),
The paint according to any one of claims 1 to 3, wherein the amine compound contains a compound (f) having an amino group and an alkoxysilyl group. The urethane prepolymer is composed of the compound (a), the polycarbonate polyol (b1), the chain extender (c), the polysiloxane (d) having an active hydrogen-containing group, and the polyisocyanate (e). The paint according to claim 4, which is a reactant. The compound (f) is N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)- The paint according to claim 4 or 5, containing at least one selected from the group consisting of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, and 3-aminopropyltriethoxysilane. Furthermore, it contains a crosslinking agent,
Any one of claims 1 to 6, wherein the crosslinking agent contains at least one selected from the group consisting of an isocyanate crosslinking agent, a carbodiimide crosslinking agent, an oxazoline crosslinking agent, an epoxy crosslinking agent, and a metal complex crosslinking agent. The paint described in item 1. The paint according to any one of claims 1 to 7, further comprising at least one matting agent selected from the group consisting of polyurethane gel particles and silica particles. A method for producing a paint according to any one of claims 1 to 8, comprising:
subjecting the precursor of the polyurethane resin (A) to a chain extension reaction with an amine compound containing a compound (f) having an amino group and an alkoxysilyl group to obtain the polyurethane resin (A) having the silanol group; and adding the silane compound (B) to the aqueous dispersion of the polyurethane resin (A). Adding the silane compound (B) to the aqueous dispersion of the polyurethane resin (A) and causing the polyurethane resin (A) and the silane compound (B) to undergo a condensation reaction with the silanol groups they have, The method for producing a paint according to claim 9, which comprises chemically bonding.