JP2023029998A - Novel emulsion and coating composition including the emulsion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel emulsion and a composition containing the emulsion.

SOLUTION: An emulsion of a (meth) acrylic polymer includes, as polymerization components, at least a reactive emulsifier (A) having a plurality of aromatic groups and a silane coupling agent (B) having a polymerizable unsaturated bond group.

SELECTED DRAWING: None

COPYRIGHT: (C)2023,JPO&INPIT

Description

The present invention relates to novel emulsions and the like.

BACKGROUND ART Interior and exterior paints (topcoats, overcoat paints) for buildings are shifting from solvent-based paints to water-based paints from the viewpoint of environmental consideration.

As such a water-based paint, for example, Patent Document 1 discloses a resin emulsion for topcoat paint of an acrylic resin using a styrene-based monomer and a silane group-containing monomer as raw materials.

JP 2017-179313 A

SUMMARY OF THE INVENTION It is an object of the present invention to provide a novel emulsion and a composition (particularly a coating composition) containing this emulsion.

Another object of the present invention is to provide an emulsion capable of efficiently forming a coating film having excellent water resistance and a composition containing this emulsion.

Another object of the present invention is to provide an emulsion having excellent thickening responsiveness and a composition containing this emulsion.

As in Patent Document 1, water-based paints using emulsions are known. In addition, it was found that problems such as peeling of the coating film may occur due to a decrease in coating film strength when the coating is exposed to rain or when coating is performed under high humidity such as in the rainy season.

In addition, the viscosity of the paint can be adjusted by adding a thickening agent. (i.e., the thickening response is not sufficient), may require high amounts of thickener, and the use of such high amounts of thickener can have an adverse effect on film formation. (For example, the water resistance of the coating film is lowered, and the viscosity increases over time during storage).

Under such circumstances, the present inventors have made further intensive studies to solve the above problems, and found that the polymerization component of the emulsion (or the polymer constituting the emulsion) is a reactive emulsifier (A) having a plurality of aromatic groups. And by comprising a polymer component containing at least a silane coupling agent (B) having a polymerizable unsaturated bond group, it is possible to form a coating film having excellent water resistance, and to improve or improve the thickening response. I found out things.

The present inventors have obtained various new findings other than those described above, and have completed the present invention through further intensive studies.

（式中、Ｄは下記式（Ｄ－１）又は（Ｄ－２）を示し、Ａは炭素数２～４のアルキレン基を示し、Ｔは水素原子又は－ＳＯ_３Ｍ（Ｍは、水素原子、アルカリ金属原子、アルカリ土類金属原子又はＮＨ_４）を示し、ｌは１～２を示し、ｍは１～３を示し、ｎは１～１０００を示す。）

（式中、Ｒ^１は水素原子又はメチル基を示す。）
［３］
重合成分が、さらに、脂環族基を有する単量体及び芳香族基を有する単量体から選択される１種以上の単量体を含む［１］又は［２］に記載のエマルション。
［４］
反応性乳化剤（Ａ）の割合が、重合成分全体に対して０．１～１０質量％である［１］～［３］のいずれかに記載のエマルション。
［５］
シランカップリング剤（Ｂ）の割合が、重合成分全体に対して０．０５～１０質量％である［１］～［４］のいずれかに記載のエマルション。
［６］
反応性乳化剤（Ａ）以外の乳化剤の割合が、重合成分全体に対して５質量％以下である［１］～［５］のいずれかに記載のエマルション。
［７］
（メタ）アクリル系ポリマーのガラス転移温度が－４０～８０℃である［１］～［６］のいずれかに記載のエマルション。
［８］
芳香族基を複数有する反応性乳化剤（Ａ）及び２－エチルヘキシル（メタ）アクリレートを少なくとも重合成分とする（メタ）アクリル系ポリマーのエマルション及びウレタン会合型増粘剤を含む塗料用組成物。
［９］
エマルションが［１］～［７］のいずれかに記載のエマルションである［８］に記載の組成物。
［１０］
［１］～［７］のいずれかに記載のエマルション又は［８］～［９］のいずれかに記載の組成物を含む塗料。
［１１］
［１０］に記載の塗料で形成された塗膜。
［１２］
［１１］に記載の塗膜を有する建築物。
［１３］
［１１］に記載の塗膜を有する建材。 That is, the present invention relates to the following inventions and the like.
[1]
A (meth)acrylic polymer emulsion comprising at least a reactive emulsifier (A) having a plurality of aromatic groups and a silane coupling agent (B) having a polymerizable unsaturated bond group as polymer components.
[2]
The emulsion according to [1], wherein the reactive emulsifier (A) contains a reactive emulsifier represented by the following formula (1).

(Wherein, D represents the following formula (D-1) or (D-2), A represents an alkylene group having 2 to 4 carbon atoms, T is a hydrogen atom or -SO ₃ M (M is a hydrogen atom , an alkali metal atom, an alkaline earth metal atom or NH ₄ ), l represents 1 to 2, m represents 1 to 3, and n represents 1 to 1000.)

(In the formula, R ¹ represents a hydrogen atom or a methyl group.)
[3]
The emulsion according to [1] or [2], wherein the polymerizable component further contains one or more monomers selected from monomers having an alicyclic group and monomers having an aromatic group.
[4]
The emulsion according to any one of [1] to [3], wherein the proportion of the reactive emulsifier (A) is 0.1 to 10% by mass with respect to the total polymerization components.
[5]
The emulsion according to any one of [1] to [4], wherein the proportion of the silane coupling agent (B) is 0.05 to 10% by mass with respect to the total polymerization components.
[6]
The emulsion according to any one of [1] to [5], wherein the proportion of the emulsifier other than the reactive emulsifier (A) is 5% by mass or less with respect to the total polymerization components.
[7]
The emulsion according to any one of [1] to [6], wherein the (meth)acrylic polymer has a glass transition temperature of -40 to 80°C.
[8]
A coating composition comprising a reactive emulsifier (A) having a plurality of aromatic groups, a (meth)acrylic polymer emulsion comprising at least a polymer component of 2-ethylhexyl (meth)acrylate, and a urethane associative thickener.
[9]
The composition according to [8], wherein the emulsion is the emulsion according to any one of [1] to [7].
[10]
A paint comprising the emulsion according to any one of [1] to [7] or the composition according to any one of [8] to [9].
[11]
A coating film formed from the paint according to [10].
[12]
A building having the coating film according to [11].
[13]
A building material having the coating film according to [11].

The present invention can provide novel emulsions and compositions containing these emulsions. Such emulsions and compositions are useful for paints and the like.

Another aspect of the present invention can provide an emulsion and composition capable of efficiently forming a coating film having excellent water resistance.

Another aspect of the present invention can provide an emulsion having excellent thickening responsiveness (which can improve or improve the thickening responsiveness) and a composition containing this emulsion.
In such an emulsion, sufficient viscosity can be obtained even if the blending amount of the thickening agent is reduced. Therefore, even with a small amount of thickening agent, a coating film can be efficiently formed, and in particular, a coating film having excellent water resistance as described above can be formed. Moreover, since it is not necessary to use a large amount of thickening agent, it is possible to reduce adverse effects (for example, increase in viscosity over time during storage) due to the use of a thickening agent in coating film formation.

<Emulsion>
The emulsion of the present invention comprises at least a reactive emulsifier (A) having a plurality of aromatic groups and a silane coupling agent (B) having a polymerizable unsaturated bond group as at least a polymer component (or a monomer component) (meth) It is an emulsion of an acrylic polymer (hereinafter sometimes referred to as (meth)acrylic polymer (a)).
In the present invention, the polymerization component of the (meth)acrylic polymer (a) contains the reactive emulsifier (A) (particularly, it is contained in combination with the silane coupling agent (B)), whereby the water resistance of the coating film is efficiently improved. can enhance or improve
Moreover, by using such a specific reactive emulsifier (A), an emulsion having excellent thickening responsiveness can be efficiently obtained. In particular, it seems that such thickening responsiveness can be further enhanced or improved by combining with the silane coupling agent (B).

The emulsion of the present invention is usually obtained by dispersing a (meth)acrylic polymer (or polymer particles) in an emulsion state in a solvent.

(Reactive emulsifier (A))
The reactive emulsifier (or reactive surfactant) (A) usually has a reactive group (or polymerizable group).
As the reactive group, a polymerizable unsaturated bond group (particularly a carbon-carbon double bond) is preferred.

In the reactive emulsifier (A), the aromatic group is not particularly limited, and examples thereof include C _6-20 aromatic hydrocarbon groups such as phenyl group and naphthyl group.
Also, the number of aromatic groups may be 2 or more, and may be, for example, 2 to 10, 2 to 8, 2 to 6, 2 to 4, and the like.

The reactive emulsifier (A) may be, for example, an anionic emulsifier, a nonionic emulsifier, a cationic emulsifier, an amphoteric emulsifier, etc. From the viewpoint of dispersibility of emulsion particles, etc., an anionic emulsifier is preferred.

Examples of anionic emulsifiers include sulfonate compounds and sulfate compounds.

（式中、Ｄは下記式（Ｄ－１）又は（Ｄ－２）を示し、Ａは炭素数２～４のアルキレン基を示し、Ｔは水素原子又は－ＳＯ_３Ｍ（Ｍは、水素原子、アルカリ金属原子、アルカリ土類金属原子又はＮＨ_４）を示し、ｌは１～２を示し、ｍは１～３を示し、ｎは１～１０００を示す。） As the reactive emulsifier (A), for example, a reactive emulsifier represented by the following formula (1) is preferable.

(Wherein, D represents the following formula (D-1) or (D-2), A represents an alkylene group having 2 to 4 carbon atoms, T is a hydrogen atom or -SO ₃ M (M is a hydrogen atom , an alkali metal atom, an alkaline earth metal atom or NH ₄ ), l represents 1 to 2, m represents 1 to 3, and n represents 1 to 1000.)

（式中、Ｒ^１は水素原子又はメチル基を示す。）

(In the formula, R ¹ represents a hydrogen atom or a methyl group.)

In particular, a reactive emulsifier represented by the following formula (2) is preferred.

（式中、Ｍは、水素原子、アルカリ金属原子、アルカリ土類金属原子又はＮＨ_４を示し、ｍは１～３を示し、ｎは１～１０００を示す。）

(Wherein, M represents a hydrogen atom, an alkali metal atom, an alkaline earth metal atom or _NH4 , m represents 1-3, and n represents 1-1000.)

Examples of preferred alkali metal atoms for M in formulas (1) and (2) include sodium and potassium.
Moreover, as an alkaline-earth metal atom, magnesium, calcium, etc. are preferable, for example.

As the reactive emulsifier (A), commercially available products may be used. 2020 and the like.

You may use a reactive emulsifier (A) individually or in combination of 2 or more types.

In the polymerization component, the proportion of the reactive emulsifier (A) depends on the type of other monomers, but from the viewpoint of improving the water resistance of the coating film, for example, the total polymerization component (or the total monomer component) is 0 .1% by mass or more, preferably 0.5% by mass or more, more preferably 1% by mass or more, particularly preferably 1.3% by mass or more (e.g., 1.5% by mass or more, 2% by mass or more, etc.) may
In the polymerized components, the proportion of the reactive emulsifier (A) may be, for example, 20% by mass or less, preferably 15% by mass or less, more preferably 10% by mass or less, of the total polymerized components.

An appropriate range (eg, 1 to 10% by mass, 1.5 to 10% by mass, etc.) may be set by appropriately combining these upper and lower limits (the same applies to others).

In the polymerized component, the proportion of the reactive emulsifier (A) depends on the type of other monomers, but from the viewpoint of improving the water resistance of the coating film, for example, 0.01 mol% or more of the total polymerized component, preferably It may be 0.05 mol % or more, more preferably 0.1 mol % or more, and particularly preferably 0.13 mol % or more (for example, 0.15 mol % or more, 0.2 mol % or more, etc.).
In the polymerization components, the proportion of the reactive emulsifier (A) may be, for example, 20 mol% or less, preferably 15 mol% or less, more preferably 10 mol% or less, of the total polymerization components.

An appropriate range (eg, 0.1 to 10 mol %, 0.15 to 10 mol %, etc.) may be set by appropriately combining these upper and lower limits (the same applies to others).

(Silane coupling agent (B))
A silane coupling agent (B) usually has a polymerizable unsaturated bond group.
Examples of polymerizable unsaturated bond groups include vinyl groups, allyl groups, and (meth)acryloyl groups.
The number of polymerizable unsaturated bond groups is not particularly limited, and may be one or more.

Examples of the silane coupling agent (B) include those having a silyl group to which a hydrolyzable (condensable) group (eg, alkoxy group, halogen atom, etc.) is bonded.
The number of silicon (atoms) in the silane coupling agent (B) may be 1 or more, or may be 2 or more (for example, oligomeric or polymeric silane coupling agents).

The silane coupling agent (B) may be, for example, a silane coupling agent (compound) represented by the following formula (3).
(R2) _n1 -Si-(R3) _4-n1 (3)
(In the formula, R2 is the same or different and represents a group having a polymerizable unsaturated bond group. R3 is the same or different and is a hydrogen atom, a hydrolytically condensable group, a hydrocarbon group, an epoxy group (epoxy group containing group). n1 represents an integer of 1 to 3.)

Examples of the polymerizable unsaturated bond group for R2 include a vinyl group, an allyl group, and a (meth)acryloyl group.

Examples of hydrocarbon groups for R3 include alkyl groups and aryl groups (such as phenyl groups). Examples of the alkyl group include C _1-4 alkyl groups such as methyl group and ethyl group.

Examples of hydrolytically condensable groups for R3 include hydroxyl groups, halogen atoms (such as chlorine atoms), alkoxy groups, acyloxy groups, aryloxy groups (such as phenoxy groups), and mercapto groups.
In R3, the alkoxy group includes, for example, a C _1-4 alkoxy group such as a methoxy group and an ethoxy group.

In R3, the acyloxy group includes, for example, C _2-4 acyloxy groups such as acetyloxy group and propionyloxy group.

Among R3, the condensation bonds between the hydrolytically condensable groups, and the condensation bonds between the hydrolytically condensable groups and other polymers (for example, the hydroxyl groups that the other polymers bond to) form crosslinks between the polymers. , is preferably a hydrolytically condensable group.
Examples of hydrolytically condensable groups include hydroxyl groups, halogen atoms (such as chlorine atoms), alkoxy groups, acyloxy groups, aryloxy groups (such as phenoxy groups), and mercapto groups, and more preferably alkoxy groups and acyloxy groups. .

Specific silane coupling agents (B) include vinyl group-containing silanes (e.g., vinyl group-containing halosilanes (e.g., vinyl mono- to trihalosilanes such as vinyltrichlorosilane), vinyl group-containing alkoxysilanes [e.g., vinylalkoxysilane]. Silanes (e.g., vinyl mono- to trialkoxysilanes such as vinyltrimethoxysilane and vinyltriethoxysilane, preferably vinyl mono- to tri- _C1-4 alkoxysilanes), vinylalkoxyalkoxysilanes (e.g., vinyltri(methoxyethoxy)silane, vinyltris( vinyl mono to tri(C _1-4 alkoxyC _1-4 alkoxy)silanes such as β-methoxyethoxy)silanes, styryl group-containing silanes (for example, styryl mono to trialkoxysilanes such as p-styryltrimethoxysilane, preferably styryl mono to tri-C _1-4 alkoxysilane)]}, (meth)acryloyl group-containing silane {e.g., (meth)acryloyl group-containing alkoxysilane [e.g., 3-(meth)acryloxypropyltrimethoxysilane, 3-( (Meth)acryloxyalkyl mono- or trialkoxysilanes such as meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, preferably ( meth)acryloxy C _2-4 alkyl mono to tri-C _1-4 alkoxysilanes], hydroxysilanes having a (meth)acryloyl group [e.g., 3-(meth)acryloxypropylhydroxysilane, 3-(meth)acryloxypropyl (meth)acryloxyalkylhydroxysilanes such as methylhydroxysilane, preferably (meth)acryloxy C _2-4 alkylhydroxysilane]}.

Among them, from the viewpoint of improving the water resistance of the coating film, etc., alkoxysilanes having a (meth)acryloyl group are preferable, (meth)acryloxyalkyl mono to trialkoxysilanes are more preferable, and (meth)acryloxy C _2-4 alkyl mono to tri-C _1-4 alkoxysilanes [eg, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, etc.] are particularly preferred.

You may use a silane coupling agent (B) individually or in combination of 2 or more types.

In the polymerization component, the ratio of the silane coupling agent (B) depends on the type of other monomers, but from the viewpoint of improving the water resistance of the coating film, for example, 0.01% by mass or more of the total polymerization component, preferably may be 0.05% by mass or more, more preferably 0.1% by mass or more, and particularly preferably 0.15% by mass or more.
In the polymerization components, the proportion of the silane coupling agent (B) is, for example, 15% by mass or less, preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 3% by mass or less of the total polymerization components. may

An appropriate range (for example, 0.05 to 10% by mass) may be set by appropriately combining these upper and lower limits (the same applies to others).

In the polymerization component, the ratio of the silane coupling agent (B) depends on the type of other monomers, but from the viewpoint of improving the water resistance of the coating film, for example, 0.01 mol% or more of the total polymerization component is preferable. may be 0.05 mol % or more, more preferably 0.1 mol % or more, and particularly preferably 0.15 mol % or more.
In the polymerization components, the proportion of the silane coupling agent (B) is, for example, 15 mol% or less, preferably 10 mol% or less, more preferably 5 mol% or less, and particularly preferably 3 mol% or less of the total polymerization components. may

An appropriate range (for example, 0.05 to 10 mol %) may be set by appropriately combining these upper and lower limits (the same applies to others).

The silane coupling agent (B), which is a structural unit of the polymerization component (polymer), has a silane functional group (silyl group) in the structural unit, and the silyl group can crosslink the polymer (a) with each other. However, the mode of such cross-linking is not particularly limited, and may be either intramolecular cross-linking or intermolecular cross-linking, or both of these modes.
The mode of cross-linking may be, for example, bonding between silyl groups in the polymer (a) (intramolecular cross-linking), or silyl groups other than the silyl groups in the polymer (a) and the silyl groups in the polymer (a). Cross-linking (intermolecular cross-linking) with a functional group (for example, a hydroxyl group in a structural unit derived from a hydroxyl-containing (meth)acrylate such as 2-hydroxyethyl (meth)acrylate described later) may be possible.

Thus, the silane coupling agent (B) can crosslink the polymer (a). A monomer (crosslinking monomer) may be included.

(Crosslinking monomer)
In the crosslinkable monomers, the cross-linking can be, for example, cross-linking by polymerization, or by chemical reaction (e.g., reaction with isocyanate, reaction with epoxy, hydrolytic silylation reaction, reaction with hydrazine, reaction with aziridine etc.).

You may use a crosslinking monomer individually or in combination of 2 or more types.

The cross-linking monomer can cross-link the polymer (a), but the form of such cross-linking is not particularly limited, and can be appropriately selected depending on the type of the cross-linking monomer. Either cross-linking may be used, or both of these modes may be cross-linked.

Examples of crosslinkable monomers that can be polymerized include compounds having two or more polymerizable double bonds.

Examples of compounds having two or more polymerizable double bonds include diol di(meth)acrylates {e.g., alkanediol di(meth)acrylates [e.g., ethylene glycol di(meth)acrylate, 1,3-butane C _2-10 alkanediols such as diol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate di (meth) acrylate, etc.], polyalkylene glycol di (meth) acrylate [e.g., diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, etc.], alkylene oxide-modified alkylene glycol di (Meth)acrylates [e.g., ethylene oxide-modified 1,6-hexanediol di(meth)acrylate, propylene oxide-modified neopentyl glycol di(meth)acrylate], di(meth)acrylates of aromatic diols or their alkylene oxide adducts [ For example, bisphenol A di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate], poly(meth)acrylates of polyols having 3 or more hydroxy groups {e.g., pentaerythritol di to tetra(meth)acrylates [ For example, pentaerythritol monohydroxytri(meth)acrylate, pentaerythritol tetra(meth)acrylate, etc.], dipentaerythritol di or hexa(meth)acrylate [for example, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth) ) acrylate, dipentaerythritol (monohydroxy) penta(meth)acrylate, etc.], trimethylolpropane di to tri(meth)acrylate [e.g., trimethylolpropane tri(meth)acrylate, trimethylolpropane triethoxy tri(meth)acrylate , ethylene oxide-modified trimethylolpropane tri(meth)acrylate, etc.], ditrimethylolpropane di to tetra(meth)acrylate [e.g., ditrimethylolpropane tetra(meth)acrylate, etc.], glycerin di to tri(meth)acrylate [e.g., ethoxy modified glycerin tri(meth)acrylate, propylene oxide modified _{Polymethacrylates} such as poly(meth)acrylates of C _3-10 polyols such as glycerol tri(meth)acrylate, etc.]; alkadiene, etc.)]; aromatic hydrocarbons (e.g., divinylbenzene, etc.)]; compounds having multiple allyl groups such as diallyl dicarboxylate (e.g., diallyl phthalate) and triallyl isocyanurate; .

Examples of crosslinkable monomers that can be crosslinked by chemical reaction include epoxy group-containing monomers, carbonyl group-containing monomers, aziridinyl group-containing monomers, and isocyanato group-containing monomers.

Examples of epoxy group-containing monomers include epoxy group-containing (meth)acrylates [e.g., glycidyl (meth)acrylate, α-methylglycidyl (meth)acrylate, glycidyloxyalkyl (meth)acrylate (e.g., 2-glycidyloxy glycidyloxy C _2-4 alkyl (meth)acrylate such as ethyl (meth)acrylate], allyl glycidyl ether, etc., but the present invention is not limited to these examples.
These epoxy group-containing monomers may be used alone or in combination of two or more.

Examples of carbonyl group-containing monomers include aldehydes having a polymerizable double bond (e.g., acrolein, formylstyrene, (meth)acryloxyalkylpropenal, etc.), ketones having a polymerizable double bond (e.g., vinyl ethyl ketone, etc.), carbonyl group-containing (meth)acrylates [e.g., acetonyl (meth)acrylate, diacetone (meth)acrylate, 2-hydroxypropyl (meth)acrylate acetylacetate, butanediol-1,4-acrylate acetylacetate, 2 -(acetoacetoxy)ethyl (meth)acrylate, etc.], but the present invention is not limited only to such examples.
These carbonyl group-containing monomers may be used alone or in combination of two or more.

Examples of aziridinyl group-containing monomers include (meth)acryloylaziridine, aziridinyl group-containing (meth)acrylates (e.g., 2-aziridinylethyl (meth)acrylate), and the like. The examples are not intended to be limiting.
These aziridinyl group-containing monomers may be used alone or in combination of two or more.

Examples of isocyanato group-containing monomers include isocyanato group-containing (meth)acrylates.
Examples of isocyanato group-containing (meth)acrylates include, for example, 2-acryloyloxyethyl isocyanate (trade name: "Karenzu AOI (registered trademark)" manufactured by Showa Denko KK), 2-methacryloyloxyethyl isocyanate (trade name: Showa Denko Co., Ltd. "Karenzu MOI (registered trademark)", etc.), 1,1-bis(acryloyloxymethyl)ethyl isocyanate (trade name: Showa Denko Co., Ltd. "Karenzu BEI (registered trademark)", etc.), 5-methacryloyl Examples thereof include oxy-3-oxypentyl isocyanate (trade name: “Karenzu MOI-EG (registered trademark)” manufactured by Showa Denko KK), etc., but the present invention is not limited to such examples.
These isocyanato group-containing monomers may be used alone or in combination of two or more.

You may use a crosslinking monomer individually or in combination of 2 or more types.

When the polymerizable component contains a crosslinkable monomer, the proportion of the crosslinkable monomer in the total polymerizable component is, for example, 0.01 to 15% by mass, preferably 0.05 to 10% by mass, more preferably 0.1 to 5%. It may be on the order of % by mass.

(other monomers)
The (meth)acrylic polymer polymerization component may contain other monomers (monomers) other than the reactive emulsifier (A) and the silane coupling agent (B) (further, the crosslinkable monomer). good.
Representative other monomers include aliphatic (meth)acrylates.

Examples of aliphatic (meth)acrylates include alkyl (meth)acrylates [e.g., methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, ) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, sec-butyl (meth) acrylate, amyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate ) acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, n-lauryl (meth)acrylate, tridecyl (meth)acrylate, stearyl (meth)acrylate, etc. C _1-20 alkyl (meth) acrylate], alkoxyalkyl (meth)acrylate [eg, alkoxyalkyl (meth)acrylate (eg, C _1-12 alkoxy C _1-12 alkyl methacrylate of 2-methoxyethyl (meth)acrylate, etc.)], and the like.

You may use an aliphatic (meth)acrylate individually or in combination of 2 or more types.

Among these aliphatic (meth)acrylates, C _1-12 alkyl (meth)acrylates such as methyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, etc. Acrylates (eg C _1-8 alkyl (meth)acrylates) are preferred, especially 2-ethylhexyl (meth)acrylate.

In the polymerized component, the proportion of the aliphatic (meth)acrylate depends on the type of other monomers, but the proportion of the aliphatic (meth)acrylate in the total polymerized component is, for example, 10 to 90% by mass, preferably 20 to It may be about 90% by mass, more preferably 25 to 80% by mass, particularly preferably about 30 to 80% by mass.

In particular, when the polymerizable component contains 2-ethylhexyl (meth)acrylate, the proportion of 2-ethylhexyl (meth)acrylate in the total polymerizable component is, for example, 10% by mass or more (for example, , 10 to 90% by mass), preferably 20% by mass or more (e.g., 20 to 90% by mass), more preferably 25% by mass or more (e.g., 25 to 80% by mass), particularly preferably 30% by mass or more (e.g., , 30 to 80% by mass).

Examples of monomers other than aliphatic (meth)acrylates include alicyclic monomers (monomers having an alicyclic group), hydroxyl group-containing (meth)acrylates, and aromatic monomers. (Aromatic group-containing monomer), acid group-containing monomer (or anionic group-containing monomer), fluorine atom-containing monomer, nitrogen atom-containing monomer, ultraviolet absorbing monomer, hindered amine system monomers (ultraviolet-stable monomers).

(Alicyclic monomer)
Alicyclic monomers include monomers having an alicyclic structure (eg, C _4-20 cycloalkyl group, preferably C _4-10 cycloalkyl group).
Specific alicyclic monomers include, for example, alicyclic (meth)acrylates [e.g., cycloalkyl (meth)acrylates (e.g., C _4-20 cycloalkyl (meth)acrylates such as cyclohexyl (meth)acrylate, acrylates, preferably C _4-10 cycloalkyl (meth)acrylates), cycloalkylalkyl (meth)acrylates (e.g. cyclohexylmethyl (meth)acrylate, cyclohexylethyl (meth)acrylate, cyclohexylpropyl (meth)acrylate, 4-methyl C _4-10 cycloalkyl C _1-4 alkyl (meth)acrylates such as cyclohexylmethyl (meth)acrylate), bridged cyclic (meth)acrylates (e.g., isobornyl (meth)acrylate, adamantyl (meth)acrylate, etc.)], etc. is mentioned.

Among the alicyclic monomers, C _4-20 cycloalkyl (meth)acrylates are preferred, C _4-10 cycloalkyl (meth)acrylates are more preferred, and isobornyl (meth)acrylate and cyclohexyl (meth)acrylate are further preferred. preferable.

Alicyclic monomers may be used alone or in combination of two or more.

When the polymerizable component contains an alicyclic monomer, the proportion of the alicyclic monomer in the total polymerizable component is, for example, 5 to 80% by mass, preferably 10 to 70% by mass, more preferably 15 It may be up to 65% by mass, particularly preferably about 20 to 60% by mass.

Further, when the polymerization component contains an aliphatic (meth) acrylate and an alicyclic monomer, the ratio of these is aliphatic (meth) acrylate / alicyclic monomer (mass ratio) = 95/ It may be 5 to 5/95 (eg, 90/10 to 10/90), preferably 80/20 to 20/80, more preferably about 80/20 to 40/60.

(hydroxyl group-containing (meth)acrylate)
Examples of hydroxyl group-containing (meth)acrylates include hydroxyalkyl (meth)acrylates [e.g., 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxy Hydroxy C _2-10 alkyl (meth) acrylates such as butyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, preferably hydroxy C _2-6 alkyl (meth) acrylates, more preferably hydroxy C _2-4 alkyl ( meth)acrylates], (meth)acrylates of polyols having 3 or more hydroxy groups [for example, (meth)acrylates of tri- or hexahydroxy C _3-10 polyols such as glycerin mono(meth)acrylate].

You may use a hydroxyl-containing (meth)acrylate individually or in combination of 2 or more types.

Among hydroxyl group-containing (meth)acrylates, 2-hydroxyethyl (meth)acrylate and glycerin mono(meth)acrylate are preferred, and 2-hydroxyethyl (meth)acrylate is more preferred.

When the polymerizable component contains a hydroxyl group-containing (meth)acrylate, the proportion of the hydroxyl group-containing (meth)acrylate in the total polymerizable component is, for example, 0.1 to 20% by mass, preferably 0.3 to 10% by mass, more preferably may be 0.5 to 8% by mass, particularly preferably about 1 to 5% by mass.

Further, when the polymerization component contains an aliphatic (meth) acrylate and / or an alicyclic monomer, and a hydroxyl group-containing (meth) acrylate, the proportion of the hydroxyl group-containing (meth) acrylate is the aliphatic (meth) acrylate And/or 100 parts by mass of the alicyclic monomer, for example, 0.1 to 20 parts by mass, preferably 0.3 to 15 parts by mass, more preferably 0.5 to 10 parts by mass, particularly preferably may be about 1 to 8 parts by mass.

(Aromatic monomer)
Examples of aromatic monomers include styrene monomers [e.g., styrene, α-alkylstyrene (e.g., α-C _1-4 alkylstyrene such as α-methylstyrene), alkylstyrene (e.g., vinyltoluene, etc.), C _1-4 alkylstyrene), halostyrene (e.g., chlorostyrene, etc.), etc.], aromatic (meth)acrylates [e.g., aryl (meth)acrylates (e.g., C _6-10 aryl (e.g., phenyl (meth)acrylate, etc. meth)acrylates), aralkyl (meth)acrylates (e.g. C _6-10 aryl C _1-4 alkyl (meth)acrylates such as benzyl (meth)acrylate, phenethyl (meth)acrylate), aryloxyalkyl methacrylates (e.g. phenoxy C _6-10 aryloxy C _1-4 alkyl methacrylate such as ethyl methacrylate), etc.].

Among aromatic monomers, styrenic monomers are preferred.

You may use an aromatic-type monomer individually or in combination of 2 or more types.

When the polymerizable component contains an aromatic monomer, the proportion of the aromatic monomer in the total polymerizable component is, for example, 0.1 to 50% by mass, preferably 0.5 to 40% by mass, more preferably may be about 1 to 35% by mass (eg, 10 to 35% by mass).

(Acid group-containing monomer)
Acid group-containing monomers (anionic group-containing monomers) include, for example, carboxylic acid group-containing monomers [e.g., unsaturated monocarboxylic acids (e.g., aliphatic acids such as acrylic acid, methacrylic acid, crotonic acid, unsaturated monocarboxylic acids), unsaturated dicarboxylic acids (e.g., aliphatic unsaturated monocarboxylic acids such as maleic acid and fumaric acid), etc.], sulfonic acid group-containing monomers [e.g., styrene-based monomers (e.g., styrene sulfonic acid, etc.)] and the like.
The acid group-containing monomer may be anionized (or form a salt).

You may use an acid-group containing monomer individually or in combination of 2 or more types.

When the polymerizable component contains an acid group-containing monomer, the proportion of the acid group-containing monomer in the total polymerizable component is, for example, 0.01 to 10% by mass, preferably 0.02 to 5% by mass, more preferably may be about 0.05 to 3% by mass.

(Fluorine atom-containing monomer)
Examples of fluorine atom-containing monomers include fluorine atom-containing acrylic monomers [e.g., fluoroalkyl (meth)acrylates (e.g., trifluoroethyl (meth)acrylate, tetrafluoropropyl (meth)acrylate, octafluoropentyl fluoro-C _1-10 alkyl (meth)acrylates such as (meth)acrylates, preferably fluoro-C _2-6 alkyl (meth)acrylates, etc.] and the like.

You may use a fluorine-atom containing monomer individually or in combination of 2 or more types.

When the polymerizable component contains a fluorine atom-containing monomer, the proportion of the fluorine atom-containing monomer in the total polymerizable component is, for example, 0.01 to 10% by mass, preferably 0.02 to 5% by mass, more preferably may be about 0.03 to 3% by mass.

(Nitrogen atom-containing monomer)
Nitrogen atom-containing monomers include, for example, (meth)acrylamide compounds {e.g., (meth)acrylamide, N-substituted (meth)acrylamides [e.g., N-alkyl (meth)acrylamides (e.g., N,N-dimethyl N,N-diC _1-4 alkyl (meth)acrylamide such as (meth)acrylamide; N,N-dimethylaminopropyl (meth)acrylamide, etc.}, nitrogen atom-containing (meth)acrylate compounds {for example, N-substituted aminoalkyl (meth)acrylates [for example, N,N-diC _1-4 alkylamino C _2-4 alkyl (meth)acrylates such as dimethylaminoethyl (meth)acrylate and diethylaminoethyl (meth)acrylate], etc. } etc. are mentioned.

You may use a nitrogen-atom containing monomer individually or in combination of 2 or more types.

When the polymerizable component contains a nitrogen atom-containing monomer, the proportion of the nitrogen atom-containing monomer in the total polymerizable component is, for example, 0.01 to 10% by mass, preferably 0.02 to 5% by mass, more preferably may be about 0.03 to 3% by mass.

(Ultraviolet absorbing monomer)
Examples of ultraviolet absorbing monomers (monomers having ultraviolet absorbing groups) include benzotriazole ultraviolet absorbing monomers and benzophenone ultraviolet absorbing monomers.

Benzotriazole-based UV-absorbing monomers include benzotriazole-based UV absorbers having a polymerizable group (e.g., (meth)acryloyl group), such as 2-[2'-hydroxy-5'-(meth)acryloyl oxymethylphenyl]-2H-benzotriazole, 2-[2'-hydroxy-5'-(meth)acryloyloxyethylphenyl]-2H-benzotriazole, 2-[2'-hydroxy-5'-(meth)acryloyl oxymethylphenyl]-5-tert-butyl-2H-benzotriazole, 2-[2′-hydroxy-5′-(meth)acryloylaminomethyl-5′-tert-octylphenyl]-2H-benzotriazole, 2 -[2'-hydroxy-5'-(meth)acryloyloxypropylphenyl]-2H-benzotriazole, 2-[2'-hydroxy-5'-(meth)acryloyloxyhexylphenyl]-2H-benzotriazole, 2 -[2'-hydroxy-3'-tert-butyl-5'-(meth)acryloyloxyethylphenyl]-2H-benzotriazole, 2-[2'-hydroxy-3'-tert-butyl-5'-( meth) acryloyloxyethylphenyl]-5-chloro-2H-benzotriazole, 2-[2′-hydroxy-5′-tert-butyl-3′-(meth)acryloyloxyethylphenyl]-2H-benzotriazole, 2 -[2'-hydroxy-5'-(meth)acryloyloxyethylphenyl]-5-chloro-2H-benzotriazole, 2-[2'-hydroxy-5'-(meth)acryloyloxyethylphenyl]-5- Cyano-2H-benzotriazole, 2-[2′-hydroxy-5′-(meth)acryloyloxyethylphenyl]-5-tert-butyl-2H-benzotriazole, 2-[2′-hydroxy-5′-( β-(meth)acryloyloxyethoxy)-3′-tert-butylphenyl]-4-tert-butyl-2H-benzotriazole and the like.

Examples of benzophenone-based UV-absorbing monomers include benzophenone-based UV absorbers having a polymerizable group (e.g., (meth)acryloyl group), such as 2-hydroxy-4-(meth)acryloyloxybenzophenone, 2-hydroxy- 4-[2-hydroxy-3-(meth)acryloyloxy]propoxybenzophenone, 2-hydroxy-4-[2-(meth)acryloyloxy]ethoxybenzophenone, 2-hydroxy-4-[3-(meth)acryloyloxy -2-hydroxypropoxy]benzophenone, 2-hydroxy-3-tert-butyl-4-[2-(meth)acryloyloxy]butoxybenzophenone and the like.

You may use an ultraviolet-absorbing monomer individually or in combination of 2 or more types.

When the polymerization component contains an ultraviolet absorbing monomer, the proportion of the ultraviolet absorbing monomer in the total polymerization component is, for example, 0.01 to 10% by mass, preferably 0.02 to 5% by mass, more preferably may be about 0.03 to 3% by mass.

(Hindered amine monomer)
Hindered amine-based monomers (UV-stable monomers, photostabilizers having polymerizable groups, photostable monomers) include, for example, 4-(meth)acryloyloxy-2,2,6,6- Tetramethylpiperidine, 4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 4-(meth)acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4-(meth) ) acryloyl-1-methoxy-2,2,6,6-tetramethylpiperidine, 4-cyano-4-(meth)acryloyloxy-2,2,6,6-tetramethylpiperidine, 1-(meth)acryloyl- 4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 4-crotonoylamino-2,2,6,6-tetramethylpiperidine, 4-(meth)acryloylamino-1,2, 2,6,6-pentamethylpiperidine, 4-cyano-4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethyl Piperidine, 1-(meth)acryloyl-4-cyano-4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 1-crotonoyl-4-crotonoyloxy-2,2,6,6 -tetramethylpiperidine and the like.

You may use a hindered amine type-monomer individually or in combination of 2 or more types.

When the polymerizable component contains a hindered amine-based monomer, the proportion of the hindered amine-based monomer in the total polymerizable component is, for example, 0.01 to 20% by mass, preferably 0.05 to 10% by mass, more preferably 0.1 to 5%. It may be on the order of % by mass.

Among the other monomers mentioned above, alicyclic monomers [for example, C _4-20 cycloalkyl (meth)acrylate (preferably C _4-10 cycloalkyl (meth)acrylate, more preferably isobornyl ( meth)acrylate, cyclohexyl (meth)acrylate, etc.)] and aromatic monomers {e.g., styrenic monomers [e.g., styrene, α-alkylstyrene (e.g., α-C _1-4 alkylstyrene, etc.), alkylstyrene (e.g., C _1-4 alkylstyrene, etc.), halostyrene (e.g., chlorostyrene, etc.)]}, in particular, one or more selected from cyclohexyl methacrylate and styrene. preferably included.

In addition, you may use the other monomer of the said illustration individually or in combination of 2 or more types.

Emulsions may generally be produced by reaction in the presence of an emulsifier, as described below.
The emulsifier may be the reactive emulsifier (A), or in addition to the reactive emulsifier (A), it may contain other emulsifiers (surfactants) that do not belong to the category of the reactive emulsifier (A). good.

Other emulsifiers may be emulsifiers that do not belong to the category of reactive emulsifiers (A), such as anionic emulsifiers, nonionic emulsifiers, cationic emulsifiers (e.g., alkylammonium salts such as decyl ammonium chloride), amphoteric emulsifiers, emulsifiers (eg, betaine ester emulsifiers) and the like.

Examples of anionic emulsifiers include alkylsulfate salts such as ammonium dodecylsulfate and sodium dodecylsulfate; alkylsulfonate salts such as ammonium dodecylsulfonate and sodium dodecylsulfonate; alkylarylsulfonate salts such as ammonium dodecylbenzenesulfonate and sodium dodecylnaphthalenesulfonate; Polyoxyethylene alkyl sulfate salts; polyoxyethylene alkyl aryl sulfate salts; polyoxyethylene alkyl ether sulfates; dialkyl sulfosuccinates; aryl sulfonic acid-formalin condensates; be done.

Examples of nonionic emulsifiers include polyoxyethylene alkyl ethers, polyoxyethylene alkyl aryl ethers, condensates of polyethylene glycol and polypropylene glycol, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, fatty acid monoglycerides, ethylene oxide and aliphatic Condensates with amines and the like can be mentioned.

Other emulsifiers also include polymeric emulsifiers. Examples of polymer emulsifiers include anionic emulsifiers (poly(meth)acrylates such as sodium polyacrylate), nonionic emulsifiers (polyvinyl alcohol, polyvinylpyrrolidone, polyhydroxyalkyl(meth)acrylates such as polyhydroxyethyl acrylate). ), and polymers containing at least one of the monomers constituting these polymers as a copolymer component.

Further, the other emulsifier may be one having a reactive group (or a polymerizable group) (reactive emulsifier) from the viewpoint of coating film physical properties.
When the emulsion contains another reactive emulsifier, the other reactive emulsifier may be a polymerization component of the (meth)acrylic polymer (a) together with the reactive emulsifier (A).

Other reactive emulsifiers include, for example, anionic emulsifiers [e.g., propenyl-alkylsulfosuccinate ester salts, (meth)acrylic acid polyoxyethylene sulfonate salts, (meth)acrylic acid polyoxyethylene phosphonate salts [e.g., Sanyo Chemical Industries Co., Ltd., trade name: Eleminol RS-30, etc.], polyoxyethylene alkylpropenyl phenyl ether sulfonate salt [e.g., Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10, etc.], allyl sulfonate salts of oxymethylalkyloxypolyoxyethylene [for example, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon KH-10, etc.], sulfonate salts of propenylnonylphenyloxypolyoxyethylene [for example, Dai-ichi Kogyo Seiyaku Co., Ltd. ( Co., Ltd., trade name: Aqualon BC-10, etc.], allyloxymethyl nonylphenoxyethyl hydroxypolyoxyethylene sulfonate salt [for example, ADEKA Co., Ltd., trade name: Adekari Soap SE-10, etc.], allyloxy Methylalkoxyethyl hydroxypolyoxyethylene sulfate salts [for example, manufactured by ADEKA Corporation, trade names: Adekari Soap SR-10, SR-30, etc.], bis(polyoxyethylene polycyclic phenyl ether) methacrylate sulfonate salts [ For example, Nippon Nyukazai Co., Ltd., trade name: Antox MS-60, etc.], nonionic emulsifiers [eg, allyloxymethylalkoxyethylhydroxypolyoxyethylene [for example, ADEKA Co., Ltd., trade name: ADEKA Riasap ER-20, etc.], polyoxyethylene alkylpropenyl phenyl ether [e.g., Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon RN-20, etc.], allyloxymethyl nonylphenoxyethyl hydroxypolyoxyethylene [e.g., manufactured by ADEKA Co., Ltd., trade name: Adekari Soap NE-10, etc.] and the like].

Other emulsifiers may be used alone or in combination of two or more.

Among these other emulsifiers, anionic emulsifiers, particularly anionic reactive emulsifiers may be preferably used.

When the emulsion contains another emulsifier, the proportion of the other emulsifier in the total polymerization components is, for example, 30% by mass or less (eg, 0.01 to 30% by mass), preferably 20% by mass or less (eg, 0.01% by mass). 01 to 20% by mass), more preferably 10% by mass or less (eg, 0.01 to 10% by mass), particularly preferably 5% by mass or less (eg, 0.01 to 5% by mass). .

The proportion of the reactive emulsifier (A) in the total emulsifier is, for example, 10% by mass or more (eg, 10 to 100% by mass, 10 to 90% by mass), preferably 40% by mass or more (eg, 40 to 100% by mass, 40 to 90% by mass), more preferably 70% by mass or more (eg, 70 to 100% by mass, 70 to 90% by mass), particularly preferably 90% by mass or more (eg, 90 to 100% by mass). , and most preferably 100% by mass.

The emulsion may have a single layer structure (consisting of only one layer) or a multilayer structure (or core-shell structure) (even if an inner layer is and) may be configured.

When the emulsion has a multilayer structure, the number of layers may be 2 or more, for example, 2 to 6, preferably 2 to 5, more preferably 2 to 4 (eg, 2 to 3). , in particular three.

When the emulsion has a multilayer structure, at least one of the outer layer (shell) and the inner layer (core) may be composed of the (meth)acrylic polymer (a) (emulsion of), and the inner layer and the outer layer It may be composed of different polymers (resins).
The (meth)acrylic polymer (a) (emulsion thereof) may constitute either the outer layer or the inner layer, but preferably constitutes at least the outer layer.
Further, when one of the outer layer and the inner layer is composed of (an emulsion of) a polymer other than the (meth)acrylic polymer (a), the polymerization component of such a polymer may be the monomers exemplified above. (eg, other monomers exemplified above).

Also, the multilayer structure may be composed (relatively composed) of a hard layer (hard layer) and a soft layer (soft layer).
In such a case, either the outer layer or the inner layer may be a hard layer, that is, the outer layer may be a hard layer and the inner layer may be a soft layer. There may be. Moreover, when the inner layer is composed of a plurality of layers, the hard layer and the soft layer may be composed between the plurality of inner layers.

The mass ratio of the polymer constituting the inner layer and the polymer constituting the outer layer is, from the viewpoint of improving the water resistance of the coating film, the polymer constituting the inner layer: the polymer constituting the outer layer (mass ratio) is, for example, 95:5. ~5:95 (eg 90:10 to 10:90), preferably 88:12 to 12:88 (eg 85:15 to 15:85), 95:5 to 20:80 ( For example, 90:10 to 30:70, preferably 88:12 to 40:60).

In particular, when the emulsion has a three-layer structure, the ratio of the first layer is 20 to 70% by mass (e.g., 30 to 60% by mass), and the ratio of the second layer is 20 to 70% by mass, relative to the entire emulsion. 70% by mass (eg, 30 to 60% by mass), and the third layer may be approximately 20 to 70% by mass (eg, 30 to 60% by mass).

The glass transition temperature of the (meth)acrylic polymer (a) constituting the emulsion is, for example, −40° C. or higher (eg, −40 to 80° C., −40 to 40° C., etc.), preferably −30° C. or higher (eg, , −30 to 80° C., −30 to 40° C., etc.), more preferably −25° C. or higher (eg, −25 to 80° C., −25 to 40° C., etc.).
In the case of an emulsion with a multilayer structure, the glass transition temperature of the entire polymer constituting the emulsion with a multilayer structure may be within the above-exemplified range.

The glass transition temperature is the glass transition temperature of the homopolymer of the monomer used for the monomer component constituting the polymer.
Formula (I): 1/Tg=Σ(Wm/Tgm)/100 (I)
[Wherein, Wm is the content (% by mass) of the monomer m in the monomer component constituting the polymer, and Tgm is the glass transition temperature (absolute temperature: K) of the homopolymer of the monomer m. ]
It may be the temperature obtained based on the Fox equation represented by .

Further, when the emulsion has a multilayer structure, the glass transition temperature of the entire polymer constituting the emulsion of the multilayer structure is the mass fraction of each monomer in all the monomer components used during the multistage emulsion polymerization. and the glass transition temperature obtained from the glass transition temperature of the homopolymer of the corresponding monomer.

The glass transition temperature of the homopolymer is, for example, −70° C. for a 2-ethylhexyl acrylate homopolymer, 83° C. for a cyclohexyl methacrylate homopolymer, 100° C. for a styrene homopolymer, and γ-methacryloxypropyltrimethoxy. 70°C for silane homopolymer, 55°C for 2-hydroxyethyl methacrylate homopolymer, 105°C for methyl methacrylate homopolymer, 130°C for methacrylic acid homopolymer, tert-butyl methacrylate homopolymer 107° C. for 1,2,2,6,6-pentamethylpiperidyl methacrylate homopolymer, about 130° C. for diacetone acrylamide homopolymer, 77° C. for diacetone acrylamide homopolymer, 55° C. for glycerin monomethacrylate homopolymer, n It is 20°C for the homopolymer of -butyl methacrylate, and -56°C for the homopolymer of n-butyl acrylate.

For monomers with unknown glass transition temperatures such as special monomers and polyfunctional monomers, the total amount of monomers with unknown glass transition temperatures in the monomer components is the mass fraction. is 10% by mass or less, the glass transition temperature may be determined using only monomers whose glass transition temperatures are known.

When the total amount of monomers with unknown glass transition temperatures in the monomer component exceeds 10% by mass in terms of mass fraction, the glass transition temperature of the polymer is determined by differential scanning calorimetry (DSC), differential calorimetry (DTA), thermal mechanical analysis (TMA), or the like.

The weight average molecular weight of the (meth)acrylic polymer (a) constituting the emulsion is, from the viewpoint of improving the water resistance of the coating film, for example, 100,000 or more, preferably 300,000 or more, more preferably 550,000 or more, especially Preferably, it may be 600,000 or more.

The upper limit of the weight-average molecular weight of the (meth)acrylic polymer (a) is not particularly limited, but is preferably 5,000,000 or less from the viewpoint of improving film-forming properties.

The weight average molecular weight is measured using, for example, gel permeation chromatography [for example, manufactured by Tosoh Corporation, product number: HLC-8120GPC, column: using TSKgel G-5000HXL and TSKgel GMHXL-L in series] ( converted to polystyrene).

The average particle size of the emulsion particles is not particularly limited, but may be, for example, 50 nm or more, preferably 100 nm or more. .
The average particle size of the emulsion particles may typically be 50 to 300 nm (eg, 60 to 250 nm), preferably about 100 to 250 nm.

The average particle diameter of the emulsion particles is the volume-average particle measured using a particle size distribution analyzer [manufactured by Particle Sizing Systems, trade name: NICOMP Model 380] using a dynamic light scattering method. diameter.

The solid content (non-volatile content) of the particles (or solid content) in the emulsion is preferably 30% by mass or more, more preferably 40% by mass or more, from the viewpoint of productivity, etc., and from the viewpoint of improving handling properties. Therefore, it may be preferably 70% by mass or less, more preferably 60% by mass or less.

The non-volatile content of the particles in the emulsion is determined by, for example, weighing 1 g of the emulsion and drying it with a hot air dryer at a temperature of 110 ° C. for 1 hour.
Formula: [non-volatile content in emulsion (mass%)] = ([mass of residue] ÷ [emulsion 1g]) × 100
can be determined based on

The minimum film-forming temperature of the emulsion may be, for example, 60° C. or lower, preferably 50° C. or lower, more preferably 40° C. or lower, from the viewpoint of improving film-forming properties.
The minimum film-forming temperature of the emulsion can be adjusted, for example, by adjusting the glass transition temperature of the entire emulsion particles or the glass transition temperature of the outermost layer.

In this specification, the minimum film-forming temperature of the emulsion is obtained by, for example, coating a resin emulsion on a glass plate placed on a thermal gradient tester with an applicator so that the thickness is 0.2 mm, cracking can be obtained as the temperature at which

The content of the polymer in the emulsion (the content of the (meth)acrylic polymer (a), or the total content of the polymers composing the inner and outer layers in the case of a multilayer structure) is For example, 20% by mass or more (eg, 25 to 100% by mass), preferably 30% by mass or more (eg, 35 to 90% by mass), more preferably 40% by mass or more (eg, 45 to 85% by mass) may

(Method for producing emulsion)
Emulsions can be obtained by emulsion polymerization of polymerizable components (monomer components) in a solvent.

Examples of the solvent include aqueous solvents such as water and solvents containing water [mixed solvent of water and alcohol (C _1-4 alcohol such as methanol, ethanol, etc.)].
You may use a solvent in combination of 1 type(s) or 2 or more types.

Methods for emulsion polymerization of monomer components include, for example, a method in which a solvent (solution) containing an emulsifier is mixed (such as dropwise) with the monomer components for polymerization, and a method in which previously emulsified monomer components are Examples include a method of mixing (dripping, etc.) in a solvent and polymerizing, but the present invention is not limited to such a method.

The amount of the solvent (medium) may be appropriately set in consideration of the amount of non-volatile matter contained in the resulting emulsion.

Polymerization may be carried out in the presence of a polymerization initiator.
Examples of polymerization initiators include azobisisobutyronitrile, 2,2-azobis(2-methylbutyronitrile), 2,2-azobis(2,4-dimethylvaleronitrile), 2,2-azobis ( azo compounds such as 2-diaminopropane) hydrochloride, 4,4-azobis(4-cyanovaleric acid), 2,2-azobis(2-methylpropionamidine); persulfates such as potassium persulfate; Examples include hydrogen, benzoyl peroxide, parachlorobenzoyl peroxide, lauroyl peroxide, and peroxides such as ammonium peroxide.
You may use a polymerization initiator in combination of 1 type or 2 or more types.

When a polymerization initiator is used, the amount of the polymerization initiator per 100 parts by mass of the polymerization component is preferably 0.05 from the viewpoint of increasing the polymerization rate and reducing the residual amount of unreacted monomer components. It is at least 0.1 part by mass, more preferably at least 0.1 part by mass, and preferably at most 1 part by mass, more preferably at most 0.5 part by mass, from the viewpoint of coating film properties and the like.

The method of adding the polymerization initiator is not particularly limited.
Also, from the viewpoint of accelerating the completion of the polymerization reaction, a part of the polymerization initiator may be added into the reaction vessel before or after the completion of adding the polymerization components into the reaction system.

In order to accelerate the decomposition of the polymerization initiator, for example, a reducing agent such as sodium bisulfite and a decomposing agent for the polymerization initiator such as a transition metal salt such as ferrous sulfate are added to the reaction system in an appropriate amount. good too.

In addition, if necessary, additives such as a chain transfer agent such as a compound having a thiol group (tert-dodecyl mercaptan, etc.), a pH buffer, a chelating agent, and a film-forming aid may be present in the reaction system. good too.

The atmosphere during polymerization is not particularly limited, but may be an inert gas such as nitrogen gas from the viewpoint of polymerization efficiency.

The polymerization temperature is not particularly limited, but may be, for example, 50 to 100°C, preferably 60 to 95°C. The polymerization temperature may be constant or may be changed during the polymerization reaction.

The polymerization time is not particularly limited, and may be appropriately set according to the progress of the polymerization reaction. time).

Moreover, an emulsion having a multilayer structure can be obtained by carrying out the above-exemplified emulsion polymerization in multiple stages.

<Composition>
The present invention also includes a composition containing a (meth)acrylic polymer emulsion containing at least a reactive emulsifier (A) having a plurality of aromatic groups as a polymerization component, and a urethane associative thickener.
The compositions of the invention can be used in particular for coatings.
In such a composition, the reactive emulsifiers (A) exemplified above can be used as the reactive emulsifier (A).

In addition, in the composition, the polymerizable component of the (meth)acrylic polymer contains the above-exemplified monomers (e.g., silane coupling agent (B), crosslinkable monomer, other monomers, etc.). may

The (meth)acrylic polymer in the composition may be the (meth)acrylic polymer (a) exemplified above, and the emulsion in the composition may be the emulsion exemplified above.

As the urethane associative thickener, for example, a urethane resin can be preferably used. The urethane-based resin is preferably water-soluble.

The urethane-based resin preferably has a hydrophobic site (hydrophobic group) and a hydrophilic site (hydrophilic group).

The bonding site of the hydrophobic group in the urethane resin is not particularly limited, and the hydrophobic group may be present at the end of the urethane resin, may be present at one end of the urethane resin, or may be present at both ends. It may be present at the ends, and preferably at both ends.
In addition, the hydrophobic group can act as an association site.
For example, in a solvent (water, an aqueous solvent containing water), the hydrophobic group site (especially the terminal hydrophobic group) associates (physically bonds) with the emulsion particle surface of the (meth)acrylic polymer (a). and/or association of the hydrophobic groups with each other can thicken the emulsion of the (meth)acrylic polymer (a).

Hydrophobic groups include, for example, hydrocarbon groups (eg, C _1-30 aliphatic hydrocarbon groups, C _3-30 aliphatic hydrocarbon groups, etc.) and the like.

The bonding site of the hydrophilic group in the urethane-based resin is not particularly limited, and the hydrophilic group may be included in the main chain of the urethane-based polymer or may be included in the side chain.

The hydrophilic site (hydrophilic group) is not particularly limited, but includes, for example, a site having an ether bond (for example, an oxyalkylene unit such as polyoxyethylene). A site having an ether bond may be, for example, a unit derived from a polyol, which is a structural unit of a urethane-based resin.

The urethane associative thickener may be one that is readily commercially available.

Examples of urethane associative thickeners include ADEKA NOL UH-420, ADEKA NOL UH-438, ADEKA NOL UH-450VF [manufactured by ADEKA Co., Ltd., trade names], etc., but the present invention provides only such examples. is not limited to
Among these, Adekanol UH-420 and the like are preferable.
The urethane associative thickeners may be used alone or in combination of two or more.

In the composition, the mass ratio of (meth)acrylic polymer:urethane associative thickener is, for example, 100:0.01 to 100:1, preferably 100:0.1 to 100:0.8, more preferably may be from 100:0.15 to 100:0.5.
In the present invention, by using the reactive emulsifier (A), it is possible to efficiently form a paint even if the ratio of the thickener to the (meth)acrylic polymer (active ingredient) is relatively small. can.

The composition may contain other thickeners than the urethane associative thickener.
Other thickeners are, for example, acrylic resins that dissolve in water (alkali-soluble) by adding a base [e.g., (meth)acrylic acid-derived units and alkyl (meth)acrylates (e.g., methyl ( meth)acrylic resin containing at least units derived from acrylate]. Such acrylic resins can thicken solutions by dissolving them in alkaline solutions.
In addition, such an acrylic resin may have an association site (for example, a hydrophobic group in the urethane resin illustrated above).

Other thickeners may be readily commercially available.
Other thickeners include, for example, Acryset WR-507 and Acryset WR-650 (manufactured by Nippon Shokubai Co., Ltd., trade names), but the present invention is limited only to such examples. not something.
Other thickeners may be used alone, respectively, or two or more of them may be used in combination.

When the composition contains other thickeners, the weight ratio of urethane associative thickener: other thickener is, for example, from 100:1 to 100:100, preferably from 100:5 to 100:90, and more. Preferably, it may be from 100:10 to 100:80.

The viscosity of the composition is, for example, 1000 to 20000 mPa s, preferably 1500 to 10000 mPa s, more preferably 2000 to 8000 mPa s, at 25 ° C. at a rotation speed of 20 rpm with a BH type viscometer. good.

The composition may contain a solvent, or may be a composition in which an emulsion and a thickening agent are dispersed (or dissolved) in a solvent.

As the solvent, any of the solvents exemplified above can be used, preferably an aqueous solvent such as water or a solvent containing water [e.g., a mixed solvent containing water and an alcohol (lower alcohol such as methanol or ethanol)]. be.
In particular, the composition may be a composition (aqueous composition) in which an emulsion and a thickening agent are dispersed (or dissolved) in an aqueous solvent.

In the composition containing a solvent, the ratio of the total amount of the emulsion and the thickening agent can be appropriately selected depending on the application. It may be up to about 80% by mass.

The composition may contain other ingredients in addition to the above ingredients (eg, emulsion and thickener).
Other components include, for example, pigments (such as pigments described later), pigment dispersants, suspending agents, ultraviolet absorbers, light stabilizers, film forming aids, thickeners, surface conditioners, preservatives and antifungal agents. , leveling agents, antifreeze agents, wetting agents, pH adjusters, antifoaming agents and the like.
You may use these components individually or in combination of 2 or more types.

The method for producing the composition is not particularly limited, and for example, the composition can be produced by mixing the emulsion and the thickening agent (and, if necessary, the solvent and other components).

(Use of emulsion and composition)
The emulsion and composition of the present invention are particularly suitable for paint (coating). Such emulsions and compositions may be used, for example, for surface finishing of substrates formed of various materials (eg, metal, glass, porcelain, concrete, siding board, resin, etc.).

Among others, the emulsion and composition of the present invention can be suitably used for topcoats (or topcoat materials, for example, topcoats for interior materials (building materials) and exterior materials).

Exterior materials include, for example, various building materials (e.g., flexible boards, calcium silicate boards, gypsum slag perlite boards, wood chip cement boards, precast concrete boards, ALC boards, inorganic building materials such as gypsum boards; e.g., roof tiles, exterior wall materials, etc. ceramic building materials, etc.). Ceramic building materials are made by, for example, adding an inorganic filler, a fibrous material, etc. to a hydraulic glue that is a raw material for an inorganic hardening material, molding the resulting mixture, and curing and hardening the resulting molding. obtained by

A topcoat material (aqueous paint) is usually applied to the surface of such an exterior material (building material) in order to impart a desired design or the like. More specifically, top coats or overcoat materials (water-based paints) are paints (architectural and used as an exterior paint). The composition of the present invention can be suitably used as this topcoat or topcoat material (aqueous paint).

In particular, among paints, it can be used as an exterior paint that is directly applied to the outer wall (exterior material) of a building and dried and cured (normal temperature drying) in a natural environment.
Since the coating formed from the emulsion or composition of the present invention has excellent water resistance of the resulting coating film, it can exhibit sufficient coating film strength even when used for such an exterior coating.

The state of the surface coating film formed using the exterior paint can be in various forms, from transparent to colored translucent to colored and hidden, but the lower coating film layer formed on the exterior material or the old For the purpose of concealing the top coat layer (improvement purpose), there are particularly many ones in the state of coloring and concealing.
Therefore, the paint composition (paint) may contain a pigment.

The pigment is not particularly limited, and known pigments can be used.
The pigment may be a colorant or an extender (weighting agent).
Typical pigments include, for example, inorganic pigments (e.g., titanium oxide, iron oxide, aluminum, inorganic coloring pigments such as pearl pigments), organic pigments (e.g., quinacridone, anthraquinone, perylene, diketopyrrolopyrrole, organic coloring pigments such as benzimidazolone, isoindolinone, anthrapyrimidine, phthalocyanine, threne, dioxazine, and carbon black), extender pigments (eg, calcium carbonate, barium sulfate, kaolin, mica, talc, etc.). .
You may use a pigment individually or in combination of 2 or more types.

In particular, it is preferable to use at least titanium oxide because it has a high glossiness on the surface of the coating film and has high color-hiding properties. The blending amount of the pigment is, for example, 5 to 70 parts by weight, preferably 7 to 65 parts by weight, more preferably 10 parts by weight with respect to 100 parts by weight of the solid content of the polymer component (or emulsion) in the dried coating film. It may be up to about 60 parts by mass.

When the composition of the present invention is used as a paint (coating), it may be applied as a single layer, or may be applied as two or more layers. When two or more layers are overcoated, only some of the layers may be formed from the composition of the present invention, or all the layers may be formed from the composition of the present invention. Overcoating is performed by, for example, applying a first layer (e.g., undercoat layer) paint to an object that has been subjected to primer treatment or sealer treatment and drying it, and then applying a second layer (e.g., topcoat layer). Examples include a method of topcoating and drying the paint, but the present invention is not limited to such a method. When applying the paint, for example, a spray, a roller, a brush, a trowel, or the like can be used.

EXAMPLES Next, the present invention will be described in more detail based on examples, but the present invention is not limited only to these examples. In addition, in the following examples, "part" means "mass part."

(Example 1)
A flask equipped with a dropping funnel, stirrer, nitrogen inlet tube, thermometer and reflux condenser was charged with 475 parts of deionized water.
465 parts of deionized water in a dropping funnel, 120 parts of 25% aqueous solution of emulsifier (Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon AR-10), 2-ethylhexyl acrylate (2EHA) 333 parts, methyl methacrylate (MMA) ) 460 parts, 200 parts of styrene (St), 5 parts of 2-hydroxyethyl methacrylate (HEMA), and 2 parts of a silyl group-containing monomer (trade name: KBM-503). was added into the flask, the temperature was raised to 80°C while gently blowing nitrogen gas, and polymerization was initiated by adding 60 parts of a 5% aqueous solution of potassium persulfate into the flask.

Next, the remainder of the pre-emulsion for dropping was uniformly dropped into the flask over 180 minutes. After the completion of dropping, the content of the flask was maintained at 80° C. for 60 minutes, and 25% aqueous ammonia was added to the flask so that the pH was 8-10 to complete the polymerization reaction.

After cooling the resulting reaction solution to room temperature, it was filtered through a wire mesh of 300 mesh (JIS mesh, hereinafter the same) to obtain a resin emulsion.

(Examples 2-6)
A resin emulsion was obtained in the same manner as in Example 1, except that the types and blending ratios of the monomers were as shown in Table 1.
In Table 1, BA indicates butyl acrylate and AA indicates acrylic acid.
The emulsifier SR-10 used in Example 3 is trade name: Adekaria Soap SR-10 (allyloxymethylalkoxyethyl polyoxyethylene sulfate) manufactured by ADEKA Corporation.
The emulsifier NF-08 used in Example 4 is manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Hytenol NF-08 (polyoxyethylene alkyl ether sulfate).

(Example 7)
A flask equipped with a dropping funnel, stirrer, nitrogen inlet tube, thermometer and reflux condenser was charged with 461 parts of deionized water.
A pre-emulsion for dropping was prepared in a dropping funnel, consisting of 59 parts of deionized water, 80 parts of a 25% aqueous solution of an emulsifier (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon AR-10), and 200 parts of styrene. was added to the flask, the temperature was raised to 80°C while gently blowing nitrogen gas, and 60 parts of a 5% aqueous solution of potassium persulfate was added to initiate polymerization.
Next, the remainder of the pre-emulsion for dropping was uniformly dropped into the flask over 60 minutes. After the addition was complete, the contents of the flask were maintained at 80°C for 60 minutes.

Then, 382 parts of deionized water, 80 parts of 25% aqueous solution of emulsifier (Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon AR-10), 240 parts of 2-ethylhexyl acrylate, 553 parts of methyl methacrylate, 2-hydroxyl A second-stage pre-emulsion consisting of 5 parts of ethyl methacrylate and 2 parts of a silyl group-containing monomer (trade name: KBM-503) was uniformly dropped into the flask over 60 minutes. After the addition was complete, the contents of the flask were maintained at 80°C for 60 minutes.

Finally, 25% aqueous ammonia was added to the flask to adjust the pH to 8-10 to terminate the polymerization reaction. After cooling the resulting reaction solution to room temperature, it was filtered through a wire mesh of 300 mesh (JIS mesh, hereinafter the same) to obtain a resin emulsion.

(Example 8)
A flask equipped with a dropping funnel, stirrer, nitrogen inlet tube, thermometer and reflux condenser was charged with 435 parts of deionized water.
A pre-emulsion for dropping was prepared in a dropping funnel, consisting of 59 parts of deionized water, 80 parts of a 25% aqueous solution of an emulsifier (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon AR-10), and 200 parts of styrene. was added to the flask, the temperature was raised to 80°C while gently blowing nitrogen gas, and 60 parts of a 5% aqueous solution of potassium persulfate was added to initiate polymerization.
Next, the remainder of the pre-emulsion for dropping was uniformly dropped into the flask over 60 minutes. After the addition was complete, the contents of the flask were maintained at 80°C for 60 minutes.

Then, 166 parts of deionized water, 80 parts of 25% aqueous solution of emulsifier (Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon AR-10), 212 parts of 2-ethylhexyl acrylate, 180 parts of methyl methacrylate, 2-hydroxyl A second stage pre-emulsion consisting of 5 parts of ethyl methacrylate and 3 parts of a silyl group-containing monomer (trade name: KBM-503) was dropped uniformly into the flask over 60 minutes. After the addition was complete, the contents of the flask were maintained at 80°C for 60 minutes.

Next, 166 parts of deionized water, 80 parts of 25% aqueous solution of emulsifier (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon AR-10), 167 parts of 2-ethylhexyl acrylate, 220 parts of methyl methacrylate, acrylic acid A third stage pre-emulsion consisting of 10 parts and 3 parts of a silyl group-containing monomer (trade name: KBM-503) was uniformly dropped into the flask over 60 minutes. After the addition was complete, the contents of the flask were maintained at 80°C for 60 minutes.

Finally, 25% aqueous ammonia was added to the flask to adjust the pH to 8-10 to terminate the polymerization reaction. After cooling the resulting reaction solution to room temperature, it was filtered through a wire mesh of 300 mesh (JIS mesh, hereinafter the same) to obtain a resin emulsion.

(Example 9)
A resin emulsion was obtained in the same manner as in Example 8, except that the types and blending ratios of the monomers were changed as shown in Table 1.

(Example 10)
A resin emulsion was obtained in the same manner as in Example 1, except that the types and blending ratios of the monomers were as shown in Table 1.

(Comparative example 1)
A resin emulsion was obtained using the method described in Example 1 of Patent Document 1.

(Reference example 1)
As an emulsifier, instead of Aqualon AR-10, ADEKA Co., Ltd., trade name: Adekaria Soap SR-10 (allyloxymethylalkoxyethyl polyoxyethylene sulfate) was used in the same manner as in Example 1. to obtain a resin emulsion.

(Reference examples 2-3)
A resin emulsion was obtained in the same manner as in Example 1, except that Adekaria Soap SR-10 was used as the emulsifier instead of Aqualon AR-10, and the type and mixing ratio of the monomers were as shown in Table 2. rice field.

(Reference example 4)
Same as Example 1 except that Aqualon BC-10 (sulfonate salt of propenyl nonylphenyloxypolyoxyethylene) manufactured by Daiichi Kogyo Seiyaku Co., Ltd. was used as the emulsifier instead of Aqualon AR-10. to obtain a resin emulsion.

(Reference example 5)
As an emulsifier, in place of Aqualon AR-10, Daiichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon KH-10 (sulfonate salt of allyloxymethylalkyloxypolyoxyethylene) was used as in Example 1. A resin emulsion was obtained in the same manner.

(Reference example 6)
As an emulsifier, in place of Aqualon AR-10, Daiichi Kogyo Seiyaku Co., Ltd., trade name: Hytenol NF-08 (polyoxyethylene alkyl ether sulfate) was used in the same manner as in Example 1. , to obtain a resin emulsion.

The physical properties of the obtained resin emulsion were measured as follows.
[Glass transition temperature (Tg)]
The glass transition temperature, using the glass transition temperature of the homopolymer of the monomer used in the monomer component constituting the polymer,
Formula (I): 1/Tg=Σ(Wm/Tgm)/100 (I)
[Wherein, Wm is the content (% by mass) of the monomer m in the monomer component constituting the polymer, and Tgm is the glass transition temperature (absolute temperature: K) of the homopolymer of the monomer m. ]
It was calculated as the temperature determined based on the Fox equation represented by .

Further, when the emulsion has a multilayer structure, the glass transition temperature of the entire polymer constituting the emulsion of the multilayer structure is the mass fraction of each monomer in all the monomer components used during the multistage emulsion polymerization. and the glass transition temperature of the homopolymer of the corresponding monomer.

[Solid content (NV)]
The non-volatile content (solid content) in the emulsion is obtained by weighing 1 g of the emulsion, drying it at a temperature of 110 ° C. for 1 hour with a hot air dryer, and using the resulting residue as a non-volatile content.
Formula: [non-volatile content in emulsion (mass%)] = ([mass of residue] ÷ [emulsion 1g]) × 100
sought based on

[viscosity]
The viscosity at 25° C. at a rotational speed of 20 rpm was determined using a BH type viscometer (manufactured by Tokyo Keiki Co., Ltd.).

[TI]
TI (thixotropic coefficient) was obtained by dividing the viscosity at a rotation speed of 2 rpm by the viscosity at 20 rpm with a BH type viscometer.
TI = Viscosity (2 rpm)/Viscosity (20 rpm)

[Volume average particle size]
The average particle size (volume average particle size) of the emulsion particles was measured using a particle size distribution measuring device (manufactured by Particle Sizing Systems, trade name: NICOMP Model 380) using a dynamic light scattering method. .

[Minimum film-forming temperature (MFT)]
A resin emulsion is applied with an applicator to a thickness of 0.2 mm on a glass plate placed on a thermal gradient tester (manufactured by Tester Sangyo Co., Ltd.), and the temperature when cracks occur is the minimum film formation temperature. and

Next, the obtained resin emulsion was evaluated by the following methods.

[Method for evaluating enamel coating gloss]
(1) Preparation of pigment paste 210 parts by mass of deionized water, dispersant [manufactured by Kao Corporation, trade name: Demoll EP, dispersant (solid content) concentration 25% by mass aqueous solution] 60 parts by mass, dispersant [Daiichi Kogyo Pharmaceutical Co., Ltd., product name: Discoat N-14, dispersant (solid content) concentration 30% by mass aqueous solution] 50 parts by mass, wetting agent [manufactured by Kao Corporation, product name: Emulgen LS-106, wetting agent (solid (Min) concentration 100% by mass] 10 parts by mass, 60 parts by mass of propylene glycol, 1000 parts by mass of titanium oxide [manufactured by Ishihara Sangyo Co., Ltd., product number: CR-95] and 200 parts by mass of glass beads (diameter: 1 mm) by homodisper. It was prepared by stirring for 60 minutes at a rotation speed of 3000 rpm. After that, in order to remove the glass beads, the mixture was filtered through a 60-mesh wire mesh to obtain a pigment paste.

(2) Preparation of enamel paint and response to thickening 2,2,4-trimethyl-1,3-pentanediol isobutyrate [manufactured by JNC Corporation, Product number: CS-12] 7 parts by mass were added, and the mixture was stirred for 10 minutes at a rotational speed of 1500 rpm with a homodisper. 42 parts by mass of the above pigment paste was added while stirring was continued. The amount of the pigment paste added was adjusted so that the amount of the pigment was 14% by volume (40% by mass) with respect to the total amount of the non-volatile matter. Furthermore, an appropriate amount of dilution water is added so that the nonvolatile content is 50% by mass, and 0.3% by mass of a silicone antifoaming agent [manufactured by San Nopco Co., Ltd., trade name: SN Deformer 777] with respect to the total amount of the paint. was added to the mixture. 5% by mass of a thickening agent [manufactured by ADEKA Co., Ltd., trade name: Adekanol UH-420] so that the viscosity at 25 ° C. at a rotational speed of 20 rpm is 4500 mPa s with a BH type viscometer [manufactured by Tokyo Keiki Co., Ltd.] An aqueous solution was added to the mixture. After that, the required thickening agent amount (unit: g) was evaluated by further stirring at 1500 rpm for 30 minutes.

[Paint film strength after submersion]
To 100 parts by mass of the aqueous resin dispersion, 7 parts by mass of 2,2,4-trimethyl-1,3-pentanediol isobutyrate [manufactured by JNC Co., Ltd., product number: CS-12] was added as a film forming aid. was used as a clear paint.
The clear paint was applied to a glass plate (length: 150 mm, width: 70 mm, thickness: 2 mm) using a 10 mil applicator and dried in the air at 23°C for 1 week to obtain a clear paint film. The obtained coating film was immersed (submerged) in water adjusted to 25° C. and scratched with a fingernail to evaluate the coating film strength according to the following criteria.
⊚: Slight scratches, but no lifting or peeling.
◯: Slightly scratched, but lifting and peeling occur partially.
x: Lifting and peeling occurred.

Table 1 shows the evaluation results of Examples, and Table 2 shows the evaluation results of Comparative Examples and Reference Examples.

As is clear from the results in Table 1 above, according to the emulsions of Examples 1 to 9, the coating films exhibited excellent water resistance, and the coating film strength after immersion in water was also excellent.
Further, according to the emulsions of the examples, the amount of thickener added to the paint could be reduced.

INDUSTRIAL APPLICABILITY The present invention can provide emulsions and compositions useful for paints and the like.

Claims (13)

A (meth)acrylic polymer emulsion comprising at least a reactive emulsifier (A) having a plurality of aromatic groups and a silane coupling agent (B) having a polymerizable unsaturated bond group as polymer components. The emulsion according to claim 1, wherein the reactive emulsifier (A) contains a reactive emulsifier represented by the following formula (1).

(Wherein, D represents the following formula (D-1) or (D-2), A represents an alkylene group having 2 to 4 carbon atoms, T is a hydrogen atom or -SO ₃ M (M is a hydrogen atom , an alkali metal atom, an alkaline earth metal atom or NH ₄ ), l represents 1 to 2, m represents 1 to 3, and n represents 1 to 1000.)

(In the formula, R ¹ represents a hydrogen atom or a methyl group.) 3. The emulsion according to claim 1 or 2, wherein the polymerizable component further contains one or more monomers selected from monomers having an alicyclic group and monomers having an aromatic group. 4. The emulsion according to any one of claims 1 to 3, wherein the proportion of the reactive emulsifier (A) is 0.1 to 10% by mass with respect to the total polymerization components. The emulsion according to any one of Claims 1 to 4, wherein the proportion of the silane coupling agent (B) is 0.05 to 10% by mass with respect to the total polymerization components. The emulsion according to any one of claims 1 to 5, wherein the proportion of the emulsifier other than the reactive emulsifier (A) is 5% by mass or less with respect to the total polymerization components. The emulsion according to any one of claims 1 to 6, wherein the (meth)acrylic polymer has a glass transition temperature of -40 to 80°C. A coating composition comprising a reactive emulsifier (A) having a plurality of aromatic groups, a (meth)acrylic polymer emulsion comprising at least a polymer component of 2-ethylhexyl (meth)acrylate, and a urethane associative thickener. The composition according to claim 8, wherein the emulsion is the emulsion according to any one of claims 1-7. A paint comprising the emulsion according to any one of claims 1-7 or the composition according to any one of claims 8-9. A coating film formed from the coating material according to claim 10 . A building having the coating film according to claim 11 . A building material having the coating film according to claim 11 .