WO2017104766A1 - Aqueous dispersion liquid, fluorine-containing coating material composition and coated article - Google Patents

Abstract

Provided are: an aqueous dispersion liquid which has excellent storage stability and provides a coating film that has excellent water resistance; a fluorine-containing coating material composition which contains this aqueous dispersion liquid; and a coated article which comprises a coating film that is formed from this fluorine-containing coating material composition. An aqueous dispersion liquid according to the present invention contains particles of a fluorine-containing polymer that has a unit derived from fluoroolefin and a unit derived from a monomer having no fluorine atom, an anionic surfactant and water. This aqueous dispersion liquid does not substantially contain a nonionic surfactant; the average particle diameter of the particles is 100 nm or less; and the absolute value of the zeta potential of the particles is 30 mV or more.

Description

Aqueous dispersion, fluorine-containing coating composition, coated article

The present invention relates to an aqueous dispersion, a fluorine-containing coating composition, and a coated article.

In recent years, from the viewpoint of protecting the natural environment, pollution such as global warming and photochemical smog due to organic solvent discharge has been a problem. Therefore, in the paint field, water-based paints containing a paint resin and using only water or a mixture of water and a water-soluble organic solvent as a medium have been developed. As the coating resin, a fluorine-containing polymer is preferably mentioned from the viewpoint of coating film properties such as weather resistance, water / oil repellency, and stain resistance.
As a method for producing an aqueous dispersion containing a fluoropolymer used as an aqueous paint, a fluoroolefin and a hydrophilic site in water under conditions where an anionic surfactant and a nonionic surfactant are present. There is known a method of polymerizing a macromonomer having a hydrogen atom (Patent Document 1).

Japanese Unexamined Patent Publication No. 7-179809

On the other hand, in recent years, there has been a demand for further improvement in the water resistance of coating films obtained from water-based paints. As described in Patent Document 1, the present inventors have disclosed an aqueous dispersion containing particles of a fluoropolymer by a polymerization method in water under the presence of an anionic surfactant and a nonionic surfactant. As a result of examining the water resistance of the coating film obtained using this aqueous dispersion, it was confirmed that the level required recently is not satisfied. In addition, an excellent aqueous storage stability is also required for an aqueous dispersion containing fluoropolymer particles.

This invention is made | formed in view of the said subject, Comprising: While providing the water resistance of a coating film, it aims at provision of the aqueous dispersion which is excellent also in storage stability.
Another object of the present invention is to provide a fluorine-containing coating composition containing an aqueous dispersion and a coated article.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a desired effect can be obtained by controlling the characteristics of the fluoropolymer particles, thereby completing the present invention.
That is, the present inventors have found that the above problem can be solved by the following configuration.
[1] A fluoropolymer particle having a unit based on a fluoroolefin and a unit based on a monomer having no fluorine atom, an anionic surfactant, and water,
Contains no nonionic surfactant or contains an amount of 0.1% by weight or less based on the aqueous dispersion;
An aqueous dispersion, wherein the average particle diameter of the particles is 100 nm or less, and the zeta potential of the particles is 30 mV or more in absolute value.

[2] The aqueous dispersion according to [1], wherein the monomer having no fluorine atom contains a monomer represented by the following formula (1).
Formula (1): XYZ
In formula (1), X represents a group having a radically polymerizable unsaturated group. Y represents a single bond or a divalent linking group. Z represents a hydrophilic group having a polyoxyalkylene chain represented by the formula — (C _m H _2m O) _n — (m represents an integer of 1 to 4. n represents an integer of 12 or more). To express.
[3] The aqueous dispersion of [2], wherein the polyoxyalkylene chain is a polyoxyethylene chain.
[4] The content of units based on the monomer represented by the formula (1) is 1.5 mol% or more based on the total units of the fluoropolymer, [2] or [ 3] aqueous dispersion.
[5] The aqueous dispersion according to any one of [1] to [4], wherein the anionic surfactant is a non-fluorinated anionic surfactant.
[6] The anionic surfactant is at least one hydrophilic selected from the group consisting of at least one lipophilic group selected from the group consisting of an alkyl group and an aryl group, and a sulfate group, sulfate group and a carboxylate group. An aqueous dispersion according to any one of [1] to [5], which is a salt of a compound having a group.
[7] The aqueous solution according to any one of [1] to [6], wherein the content of the anionic surfactant is 0.01% to 1.5% by mass with respect to the mass of the fluoropolymer. Dispersion.

[8] Polymerizing a fluoroolefin and a monomer represented by the following formula (1) in water under the condition that a nonionic surfactant is not present and a non-fluorine anionic surfactant is present. An aqueous dispersion in which particles of a fluoropolymer having units based on the fluoroolefin and units based on the monomer represented by the following formula (1) are dispersed in water is obtained. Liquid manufacturing method.
Formula (1): XYZ
In formula (1), X represents a radically polymerizable unsaturated group. Y represents a single bond or a divalent linking group. Z represents a hydrophilic group having a polyoxyalkylene chain represented by the formula — (C _m H _2m O) _n — (m represents an integer of 1 to 4. n represents an integer of 12 or more). To express.
[9] The amount of the monomer represented by the formula (1) is 1.5 mol% or more based on the total amount of the monomers used for the polymerization of the fluoropolymer. [8] The production method.
[10] The amount of the non-fluorinated anionic surfactant used is 0.01% to 1.5% by mass with respect to the total mass of monomers used for the polymerization of the fluoropolymer. [8] The production method according to [9].
[11] The production method of any one of [8] to [10], wherein the average particle size of the particles is 100 nm or less.
[12] The method according to any one of [8] to [11], wherein the zeta potential of the particles is 30 mV or more in absolute value.

[13] A fluorine-containing coating composition comprising the aqueous dispersion of any one of [1] to [7].
[14] The fluorine-containing coating composition according to [13], further comprising a thickener.
[15] A coated article having a substrate and a coating film disposed on the substrate and formed using the fluorine-containing coating composition of [13] or [14].

ADVANTAGE OF THE INVENTION According to this invention, while being excellent in the water resistance of a coating film, the aqueous dispersion liquid which is excellent also in storage stability can be provided.
Moreover, according to this invention, the fluorine-containing coating composition containing an aqueous dispersion and the coated article can also be provided.

In this specification, “unit based on monomer” means an atomic group directly formed by polymerization of one monomer molecule and an atomic group obtained by chemically converting a part of the atomic group. It is a generic name. Hereinafter, the unit based on the monomer is also simply referred to as “unit”.
The monomer represents a compound having a polymerizable carbon-carbon double bond.
The content (mol%) of each unit in the polymer is determined by analyzing the polymer by a nuclear magnetic resonance spectrum method, but can also be estimated from the charged amount of each monomer.
The number average molecular weight of the polymer is a number average molecular weight measured by gel permeation chromatography using polystyrene as a standard substance. The number average molecular weight is also simply referred to as “Mn”.
“(Meth) acrylic acids” is a general term for “acrylic acid”, “acrylate”, “methacrylic acid”, and “methacrylate”.
The fact that the aqueous dispersion of the present invention does not contain a nonionic surfactant or contains 0.1% by mass or less with respect to the aqueous dispersion is hereinafter referred to as “substantially containing a nonionic surfactant”. It's also not.

Features of the aqueous dispersion of the present invention are that it contains substantially no nonionic surfactant, and the average particle diameter and zeta potential of the fluoropolymer particles are within a predetermined range. Is mentioned.
In the patent document 1, the present inventors have found that a nonionic surfactant is related as a factor that decreases the water resistance of a coating film obtained from an aqueous dispersion. That is, it has been found that the water resistance of the coating film deteriorates when the nonionic surfactant in the aqueous dispersion is contained in the coating film. Therefore, the aqueous dispersion of the present invention does not substantially contain a nonionic surfactant.
Further, since the average particle diameter of the fluoropolymer particles is 100 nm or less, a coating film (hereinafter simply referred to as “coating”) obtained from the aqueous dispersion of the present invention (or the fluorine-containing coating composition containing the aqueous dispersion). It is presumed that the fluorine-containing polymer particles are likely to be packed tightly when forming the film. As a result, it is considered that the occurrence of pinholes in the coating film is suppressed and the water resistance of the coating film is improved. Further, since the absolute value of the zeta potential of the fluoropolymer particles is not less than a predetermined value, repulsion between the particles tends to occur, and as a result, the storage stability of the aqueous dispersion is improved.
In addition, as a method for obtaining the above particles, a predetermined amount or more of a monomer containing a polyoxyalkylene chain having a predetermined length is used in the production of the fluoropolymer, and an anionic surfactant is used. The method to be described later is used.

The aqueous dispersion of the present invention contains fluoropolymer particles having a predetermined unit, an anionic surfactant, and water.
Hereinafter, each component contained in the aqueous dispersion will be described in detail.
The particles of the fluoropolymer in the present invention are a unit based on a fluoroolefin (hereinafter also referred to as “unit A”) and a unit based on a monomer having no fluorine atom (hereinafter also referred to as “unit B”). )).
The fluoropolymer is dispersed in the form of particles in the aqueous dispersion.

The average particle diameter of the particles is 100 nm or less, the water resistance of the coating film is more excellent, and the storage stability of the aqueous dispersion is more excellent (hereinafter also referred to as “the effect of the present invention is more excellent”). 90 nm or less is preferable, 80 nm or less is more preferable, and 70 nm or less is more preferable. The lower limit is not particularly limited, but is usually 50 nm.
When the average particle diameter of the particles exceeds 100 nm, the water resistance of the coating film is poor.
In addition, the value of D50 calculated | required by the dynamic light scattering method using ELS-8000 (made by Otsuka Electronics Co., Ltd.) is made into an average particle diameter. In addition, D50 represents the particle diameter of 50 volume% of cumulative volume calculated from the small particle side in the particle size distribution of the particle measured by the dynamic light scattering method.

In addition, the absolute value of the zeta potential of the particles is 30 mV or more, and 40 mV or more is preferable and 45 mV or more is more preferable in that the effect of the present invention is more excellent. The upper limit is not particularly limited, but is usually 60 mV.
When the absolute value of the zeta potential of the particles is less than 30 mV, the storage stability of the aqueous dispersion is poor.
The value of the zeta potential may be a positive value or a negative value as long as the absolute value is within the above range. In addition, it is preferable that it is a negative value at the point which the effect of this invention is more excellent.
The zeta potential is measured by electrophoretic light scattering using ELS-8000 (manufactured by Otsuka Electronics Co., Ltd.).

The fluoroolefin which becomes the unit A by polymerization is a compound in which one or more hydrogen atoms of the olefin are substituted with fluorine atoms.
The carbon number of the fluoroolefin is preferably 2 to 8, and more preferably 2 to 6.
The number of fluorine atoms in the fluoroolefin is preferably 2 or more, more preferably 3-4. When the number of fluorine atoms is 2 or more, the weather resistance of the coating film is more excellent.
In the fluoroolefin, one or more hydrogen atoms not substituted with fluorine atoms may be substituted with chlorine atoms.
Examples of the fluoroolefin include CF ₂ = CF ₂ , CF ₂ = CFCl, CF ₂ = CHF, CH ₂ = CF ₂ , CF ₂ = CFCF ₃ , CF ₂ = CHCF _{3 and the} like. Therefore, CF ₂ = CF ₂ or CF ₂ = CFCl is preferable, and CF ₂ = CFCl is more preferable.
Only one type of fluoroolefin may be used, or two or more types may be used in combination.

The content of unit A is preferably 20 to 70 mol%, more preferably 30 to 70 mol%, still more preferably 30 to 60 mol%, and more preferably 40 to 60 mol%, based on all units of the fluoropolymer. Particularly preferred is 45 to 55 mol%. When the content of the unit A is 20 mol% or more, the weather resistance of the coating film is more excellent. If the content of the unit A is 70 mol% or less, the dispersibility of the particles in water is excellent.

Monomers having no fluorine atom that becomes unit B by polymerization include vinyl ethers, allyl ethers, vinyl esters, allyl esters, α-olefins, (meth) acrylic acids having no fluorine atom. Is mentioned. From the viewpoint of alternating copolymerization with a fluoroolefin, vinyl ethers having no fluorine atom or alkyl vinyl esters having no fluorine atom are more preferred.

One preferred embodiment of the monomer having no fluorine atom is a monomer represented by the formula (1) (hereinafter also referred to as “monomer 1”). Monomer 1 does not have a fluorine atom.
Formula (1): XYZ
The symbol in Formula (1) represents the following meaning.
X represents a group having a radically polymerizable unsaturated group. The radical polymerizable unsaturated group is a group having a carbon-carbon unsaturated double bond, and may have a divalent group having a hetero atom at the Y side terminal. The _{X, CH 2 = CH-, CH} 3 CH = CH-, CH 2 = C (CH 3) -, the formula ^{_{CH 2 = CHC (O) X}} A - , a group represented by the formula _CH 2 = C ( The group represented by CH ₃ ) C (O) X ^A —, CH ₂ ═CHOC (O) —, CH ₂ ═CHO—, and CH ₂ ═CHCH ₂ O— are preferred. From the viewpoint of alternating copolymerization with a fluoroolefin, CH ₂ ═CHO— and CH ₂ ═CHCH ₂ O— are particularly preferred. Here, X ^A represents a single bond, an etheric oxygen atom (—O—), or a group represented by the formula —NX ^A1 — (X ^A1 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms). To express.

Y represents a single bond or a divalent linking group.
Examples of the divalent linking group include a hydrocarbon group such as an alkylene group or an arylene group, a hydrocarbon group having a hetero atom such as an oxygen atom or a nitrogen atom, and the like.
The divalent linking group is preferably a divalent hydrocarbon group having 1 to 20 carbon atoms and having a hetero atom at the Z-side end. The Z-side terminal of the divalent hydrocarbon group is an etheric oxygen atom (—O—), —C (O) —, —C (O) O—, —C (O) NX ^A2 —, or —SO _2. It preferably has NX ^A2 — and has an etheric oxygen atom (—O—) or —C (O) O—. X ^A2 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.
Specific examples of the divalent hydrocarbon group include divalent saturated hydrocarbon groups such as alkylene groups, divalent unsaturated hydrocarbon groups such as alkenylene groups and alkynylene groups, and divalent aromatic carbon groups such as phenylene groups. A hydrogen group is mentioned. The divalent saturated hydrocarbon group may be linear, branched or cyclic, and preferably has 1 to 20 carbon atoms. The carbon number of the divalent aromatic hydrocarbon group is preferably 5-20.
The divalent linking group is preferably an alkyleneoxy group or alkylenecarbonyloxy group having 1 to 20 carbon atoms, particularly preferably an alkyleneoxy group. The alkylene moiety in these groups may be linear, branched or cyclic.

Z represents a hydrophilic group having a polyoxyalkylene chain represented by the formula — (C _m H _2m O) _n —, and the polyoxyalkylene chain represented by the formula — (C _m H _2m O) _n —R Nonionic hydrophilic groups having the following are preferred.
Here, m represents an integer of 1 to 4. m is preferably 1 to 3 and more preferably 2 in that the effect of the present invention is more excellent. Note that — (C _m H _2m O) _n — may include a plurality of — (C _m H _2m O) — having different _m .
n is the number of oxyalkylene units and represents an integer of 12 or more. n is preferably 13 or more and more preferably 15 or more in that the effect of the present invention is more excellent. The upper limit is preferably 40 and more preferably 20.
R represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or a phenyl group, preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, particularly preferably a hydrogen atom.
Since — (C _m H _2m O) _n —R is a hydrophilic group, it is more preferable that at least a part of the oxyalkylene unit is an oxyethylene group and that all of the oxyalkylene units are oxyethylene groups.
When the polyoxyalkylene chain has an oxyalkylene unit other than an oxyethylene group, the oxyalkylene unit other than the oxyethylene group is preferably an oxypropylene group. The bonding order of the oxyethylene group and the other oxyalkylene group may be random or block. The number of oxyethylene groups relative to the total number (n) of oxyethylene groups and other oxyalkylene groups is preferably 50% or more.

A preferable embodiment of the monomer 1 is a monomer represented by the formula X ¹ —Y ¹ — (C _m H _2m O) _n —R ^{1 in} that the effect of the present invention is more excellent.
The symbols in the formula represent the following meanings.
X ¹ _is, CH 2 = _CHO-, or _{CH 2} = CHCH 2 O- to _represent, CH 2 = CHO- are preferred.
Y ¹ represents a group represented by the formula —C _a H _2a O— (a represents an integer of 1 to 10), or a group represented by the formula —CH ₂ -cycloC ₆ H ₁₀ —CH ₂ O—. Represents. Here, “-cycloC ₆ H ₁₀ —” represents a cyclohexylene group. There are 1,4-, 1,3-, 1,2-bonding sites for the cyclohexylene group, but 1,4- is usually adopted.
m and n represent the same meaning as described above, and the preferred range is also the same.
R ¹ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, preferably a hydrogen atom.

The content of the unit based on the monomer 1 (hereinafter also referred to as “unit B1”) is 1.5 mol% or more of the total units of the fluoropolymer in that the effect of the present invention is more excellent. Is preferable, and 2 mol% or more is more preferable. The upper limit is usually 15 mol%, and 10 mol% is preferable in that the effect of the present invention is more excellent.

As another preferred embodiment of the monomer having no fluorine atom, a monomer other than the monomer 1 which does not contain a fluorine atom and has a non-aromatic cyclic hydrocarbon group in the side chain (Hereinafter also referred to as “monomer 2”).
The non-aromatic cyclic hydrocarbon group is preferably a cyclic saturated hydrocarbon group. Further, the cyclic hydrocarbon group may have a side chain group such as an alkyl group. Further, it may have a crosslinkable group bonded to a ring carbon atom or a side chain group.
The number of carbon atoms constituting the ring of the cyclic hydrocarbon group is preferably from 4 to 20, more preferably from 5 to 10, from the viewpoint of alternating copolymerizability with the fluoroolefin.
Specific examples of the cyclic hydrocarbon group include a monocyclic saturated hydrocarbon group such as a cyclobutyl group, a cycloheptyl group, and a cyclohexyl group, a bicyclic saturated hydrocarbon group such as a 4-cyclohexylcyclohexyl group, and a 1-decahydronaphthyl group. Polycyclic saturated hydrocarbon groups such as 2-decahydronaphthyl group, bridged cyclic saturated hydrocarbon groups such as 1-norbornyl group and 1-adamantyl group, spiro hydrocarbon groups such as spiro [3.4] octyl group Is mentioned.
When the ring has a side chain group, the side chain group is preferably an alkyl group or a crosslinkable group-containing alkyl group (such as a hydroxyalkyl group), and preferably has 6 or less carbon atoms. Two or more side chain groups may be present.

Monomer 2 is a vinyl ether, allyl ether, vinyl ester, allyl ester which is a monomer other than monomer 1 and has no fluorine atom and has a non-aromatic cyclic hydrocarbon group. Acrylic acid esters, methacrylic acid esters, and the like, and more specifically, cycloalkyl vinyl ethers such as cyclohexyl vinyl ether.
Monomer 2 may be used alone or in combination of two or more.

A preferred embodiment of the monomer 2 includes a monomer represented by the formula X ² —Y ² —R ² .
The symbols in the formula represent the following meanings.
X ² represents CH ₂ ═CHC (O) O—, CH ₂ ═C (CH ₃ ) C (O) O—, CH ₂ ═CHOC (O) —, CH ₂ ═CHO—, or CH ₂ ═CHCH ₂ O— represents CH ₂ ═CHO—.
Y ² represents a single bond or an alkylene group having 4 or less carbon atoms.
R ² represents a monovalent non-aromatic cyclic hydrocarbon group having 4 to 20 carbon atoms, and the cyclic hydrocarbon group is preferably a cycloalkyl group having 5 to 10 carbon atoms. The cyclic hydrocarbon group which is R ² may have the side chain group.

The content of the unit based on the monomer 2 (hereinafter also referred to as “unit B2”) is 0 to 45 mol% of the total units of the fluoropolymer in that the effect of the present invention is more excellent. Preferably, it is 1 to 40 mol%, more preferably 3 to 35 mol%, still more preferably 5 to 30 mol%.

As another preferred embodiment of the monomer having no fluorine atom, a monomer other than the monomer 1 and the monomer 2, which is a monomer having no crosslinkable group and having no fluorine atom. A monomer (hereinafter also referred to as “monomer 3”). As will be described in detail later, when the fluorine-containing polymer has a crosslinkable group, the coating film can be cured by adding a curing agent to the fluorine-containing coating composition, and weather resistance, water resistance, chemical resistance The physical properties of the coating film such as properties and heat resistance can be further improved.
Incidentally, the formula _{- (C m H 2m O)} n - monomer containing a crosslinking group hydrophilic group having a polyoxyalkylene chain represented by are included in the monomer 1. A monomer containing a crosslinkable group and a non-aromatic cyclic hydrocarbon group is included in the monomer 2.
Specific examples of the crosslinkable group include functional groups having active hydrogen (hydroxy group, carboxy group, amino group, etc.), hydrolyzable silyl groups (alkoxysilyl group, etc.), epoxy groups, oxetanyl groups, and the like.
As the monomer 3, one type may be used alone, or two or more types may be used in combination.

A preferred embodiment of the monomer 3 includes a monomer represented by the formula X ³ —Y ³ —R ³ —V ³ .
The symbols in the formula represent the following meanings.
X ³ represents CH ₂ ═CHC (O) O—, CH ₂ ═C (CH ₃ ) C (O) O—, CH ₂ ═CHOC (O) —, CH ₂ ═CHO—, or CH ₂ ═CHCH ₂ O— represents CH ₂ ═CHO—.
Y ³ represents a single bond.
R ³ represents an alkylene group having 2 to 20 carbon atoms, which may be cyclic, and preferably an alkylene group having 2 to 8 carbon atoms.
V ³ is a hydroxy group, a carboxy group or an amino group, preferably a hydroxy group.

Monomers 3 include hydroxyalkyl vinyl ether (2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, etc.), hydroxyalkyl allyl ethers (hydroxyethyl allyl ether, etc.), hydroxyalkyl (meth) acrylate (hydroxyethyl ( (Meth) acrylate, etc.), and a hydroxyalkyl vinyl ether having a hydroxyalkyl group having 6 or less carbon atoms is preferred from the viewpoint of excellent alternating copolymerization with a fluoroolefin and better weather resistance of the coating film.

The content of the units based on the monomer 3 (hereinafter also referred to as “unit B3”) is 0 to 20 mol% of the total units of the fluoropolymer in that the effect of the present invention is more excellent. Preferably, 0 to 18 mol% is more preferable, and 0 to 15 mol% is more preferable.

As another preferred embodiment of the monomer having no fluorine atom, a monomer other than the monomer 1, the monomer 2 and the monomer 3, which is a fluorine atom, a cyclic hydrocarbon group, and a bridge A monomer having no ionic group (hereinafter also referred to as “monomer 4”).
Examples of the monomer 4 include vinyl ethers, allyl ethers, vinyl esters, allyl esters, olefins, acrylic esters, and methacrylic esters that do not have any fluorine atom, cyclic hydrocarbon group, or crosslinkable group. .
A preferred embodiment of the monomer 4 includes a monomer represented by the formula X ⁴ -Y ⁴ -R ⁴ .
The symbols in the formula represent the following meanings.
X ⁴ represents CH ₂ ═CHC (O) O—, CH ₂ ═C (CH ₃ ) C (O) O—, CH ₂ ═CHOC (O) —, CH ₂ ═CHO—, or CH ₂ ═CHCH ₂ O— represents CH ₂ ═CHOC (O) — or CH ₂ ═CHO—.
Y ⁴ represents a single bond.
R ⁴ represents an alkyl group having 2 to 20 carbon atoms. R ⁴ may be linear or branched.

As the monomer 4, alkyl vinyl ether (nonyl vinyl ether, 2-ethylhexyl vinyl ether, hexyl vinyl ether, ethyl vinyl ether, n-butyl vinyl ether, tert-butyl vinyl ether, etc.), alkyl allyl ether (ethyl allyl ether, hexyl allyl ether, etc.), Examples include vinyl esters of carboxylic acids (such as acetic acid, butyric acid, pivalic acid, benzoic acid, and propionic acid), allyl esters of carboxylic acids (such as acetic acid, butyric acid, pivalic acid, benzoic acid, and propionic acid), ethylene, propylene, and isobutylene. It is done.

The content of the unit based on the monomer 4 (hereinafter also referred to as “unit B4”) is 0 to 50 mol% of the total units of the fluoropolymer in that the effect of the present invention is more excellent. Preferably, it is 5 to 45 mol%, more preferably 15 to 40 mol%.

In the fluoropolymer in the present invention, the unit A, the unit B1, the unit B2, the unit B3, and the unit B4 are 30 to 70 mol% and 1.5 mol% in this order with respect to all units of the fluoropolymer. The content is preferably 0 to 45 mol%, 0 to 20 mol%, and 0 to 50 mol%.
In the fluorine-containing polymer, the molar ratio of unit A to unit B (unit A / unit B) is preferably 20/80 to 70/30, more preferably 30/70 to 30 from the viewpoint of better effects of the present invention. 60/40 is more preferable, and 40/60 to 60/40 is even more preferable.
The number average molecular weight (Mn) of the fluoropolymer is preferably 30,000 to 200,000, more preferably 50,000 to 180,000.

The anionic surfactant in the present invention is preferably a non-fluorinated anionic surfactant from the viewpoint of further improving the storage stability of the aqueous dispersion and the water resistance of the coating film.
The non-fluorinated anionic surfactant includes at least one lipophilic group selected from the group consisting of an alkyl group and an aryl group, a sulfate group (—OSO ₃ ⁻ ), a sulfate group (—SO ₃ ⁻ ), and a carboxylate group. A salt of a compound having at least one hydrophilic group selected from the group consisting of (—COO ⁻ ) is preferred, and a salt of a compound having the lipophilic group and a sulfate group or sulfate group is particularly preferred.

The counter ion forming the salt is preferably an alkali metal ion or an ammonium salt, more preferably an alkali metal ion, and particularly preferably a sodium ion from the viewpoint of suppressing coloring of the aqueous dispersion.
The lipophilic group preferably has 8 to 24 carbon atoms. The number of carbon atoms of the alkyl group in the lipophilic group is preferably 8 to 24, and particularly preferably 10 to 18. The aryl group in the lipophilic group is preferably a group having a benzene ring or a naphthalene ring, particularly preferably a phenyl group or a naphthyl group, and particularly preferably a phenyl group.
Moreover, the lipophilic group may be comprised from both the alkyl group and the aryl group, for example, may be a phenylalkyl group.
The content of the hydrophilic group is preferably 1 or 2 in one molecule, particularly preferably 1.
Specific examples of non-fluorinated anionic surfactants include fatty acid anionic surfactants, linear alkylbenzene anionic surfactants, higher alcohol anionic surfactants, alpha olefin anionic surfactants, normal Examples include paraffinic anionic surfactants, and more specific examples include sodium lauryl sulfate, sodium dodecylbenzene sulfonate, sodium alkyl sulfonate, sodium alkyl benzene sulfonate, sodium succinate dialkyl ester sulfonate, alkyl Examples include diphenyl ether disulfonic acid sodium salt.

The content of the anionic surfactant in the aqueous dispersion of the present invention is preferably 0.001 to 5% by mass with respect to the total mass of the fluoropolymer in that the effect of the present invention is more excellent. From the viewpoint of water resistance when the coating film is immersed for a long time, the content is more preferably 0.01 to 1.5% by mass, and particularly preferably 0.1 to 0.4% by mass.

The content of the fluoropolymer particles in the aqueous dispersion of the present invention is preferably 10 to 70% by mass, and preferably 20 to 65% by mass with respect to the total mass of the aqueous dispersion in that the effect of the present invention is more excellent. Is more preferable.
The content of water in the aqueous dispersion of the present invention is preferably from 30 to 85% by mass, more preferably from 35 to 75% by mass, based on the total mass of the aqueous dispersion, from the viewpoint that the effects of the present invention are more excellent.

The aqueous dispersion of the present invention contains components other than the fluorine-containing polymer particles, the anionic surfactant and water (hereinafter also referred to as “other components”) as long as the effects of the present invention are not impaired. It may be.
However, the non-ionic surfactant is not substantially contained in the aqueous dispersion. As described above, “substantially free” means that the content of the nonionic surfactant is 0% by mass or 0.1% by mass or less based on the total mass of the aqueous dispersion. It means that there is. The content of the nonionic surfactant is preferably 0% by mass or less, more preferably 0% by mass, even if it is 0% by mass or included.
Specific examples of the nonionic surfactant include alkylphenyl polyoxyethylene, alkyl polyoxyethylene, alkyl polyoxyalkylene polyoxyethylene, fatty acid ester, alkylamineoxyethylene adduct, alkylamidooxyethylene adduct, alkylamineoxy Examples thereof include ethyleneoxypropylene adducts and alkylamine oxides.

Other components that may be included in the aqueous dispersion of the present invention include a water-soluble liquid medium and a color tone adjusting agent.
Examples of the water-soluble liquid medium include water-soluble organic solvents such as ethanol, ethanol, and butanol. When the aqueous dispersion of the present invention contains a water-soluble liquid medium, the content thereof is preferably 5% by mass or less, more preferably 1% by mass or less, and more preferably 0.1% by mass or less with respect to the total mass of water. Is particularly preferred. Most preferably, the aqueous dispersion of the present invention does not contain a water-soluble liquid medium.
Examples of the color tone adjusting agent include a fluorescent whitening agent and hydrogen peroxide for adjusting the color tone of the aqueous dispersion.
For example, when the color tone of the aqueous dispersion liquid of the present invention is adjusted to white, the aqueous white dispersion liquid may contain a fluorescent whitening agent. Examples of the fluorescent brightener include a coumarin fluorescent brightener and a benzoxazole fluorescent brightener. Specific examples of the optical brightener include 3- (4′-acetylaminophenyl) -7-acetylaminocoumarin, 3- (4′-carboxyphenyl) -4-methyl-7-diethylaminocoumarin, 2,5- Examples thereof include bis (5′-t-butylbenzoxazol-2′-yl) thiophene and 2,5-bis [5′-t-butylbenzooxazolyl] thiophene. The content of the optical brightener is preferably 0.001 to 500 ppm by mass, and more preferably 0.01 to 100 ppm by mass with respect to the total mass of the aqueous dispersion.
Also, when adjusting a color tone of the aqueous dispersion in whiteness, the aqueous dispersion may contain H ₂ O _2. The content of H ₂ O ₂ is preferably 0.001 to 1000 ppm by mass and more preferably 50 to 500 ppm by mass with respect to the total mass of the aqueous dispersion.

The method for producing an aqueous dispersion of the present invention is characterized in that a monomer mixture containing a fluoroolefin and a monomer having no fluorine atom is mixed with an anionic surfactant, water, and polymerization from the viewpoint of excellent productivity. And a method of polymerizing in the presence of an agent. This method corresponds to so-called emulsion polymerization, and an aqueous dispersion containing fluoropolymer particles is obtained by polymerization.
Various components (fluoroolefin, monomer having no fluorine atom, anionic surfactant, etc.) used in this method are as described above.
The amount of the anionic surfactant used relative to the total mass of the monomer mixture containing the fluoroolefin and the monomer having no fluorine atom is 0.01 to 1 in that the effect of the present invention is more excellent. 0.5% by mass is preferable, and 0.05 to 1% by mass is more preferable.

The polymerization initiator is appropriately selected from the polymerization formats. When the polymerization initiator is a radical polymerization format, a known radical initiator can be used. Specific examples of radical initiators include persulfates such as ammonium persulfate, redox initiators composed of combinations of hydrogen peroxide and sodium hydrogen sulfite, inorganic initiators such as ferrous salts and silver nitrate. And organic initiators such as dibasic acid peroxides such as disuccinic acid peroxide and diglutaric acid peroxide, and azobisbutyronitrile.
For example, 0.01 to 5% by mass of the polymerization initiator can be used with respect to the total mass of the mixture.

In addition, a trace amount of hydrogen chloride or hydrogen fluoride may be generated during the polymerization, and the polymerization system may contain a buffer (pH adjusting agent) as necessary. Buffers include inorganic bases such as sodium carbonate, potassium carbonate, sodium hydrogen orthophosphate, sodium thiosulfate, and sodium tetraborate, and organic bases such as triethylamine, triethanolamine, dimethylethanolamine, and diethylethanolamine. Can be mentioned.
Furthermore, the polymerization system may contain other components (for example, an organic solvent) as necessary.
The polymerization temperature is usually about 0 to 100 ° C., preferably 10 to 90 ° C.
The polymerization pressure is usually 0.1 to 10 MPa, preferably 0.2 to 5 MPa.

In polymerization, components such as a monomer mixture, an anionic surfactant, water, and a polymerization initiator may be charged as they are for polymerization, and a stirrer such as a homogenizer is added before adding the polymerization initiator. It may be pre-emulsified and then polymerized by adding a polymerization initiator. In addition, the method of charging the monomer mixture is a method of charging the entire amount into the reactor at once, a method of continuously charging the total amount of the monomer mixture, and dividing the total amount of the monomer mixture. A method of charging, a method of charging a part of the monomer mixture and reacting first, and then charging the remainder in a divided or continuous manner can be employed.

A preferred embodiment of the above-described method for producing an aqueous dispersion of the present invention (hereinafter also simply referred to as “production method of the present embodiment”) is a non-fluorinated anionic surfactant without a nonionic surfactant. Can be obtained by polymerizing the fluoroolefin and the monomer 1 in water under a condition in which the fluorine-containing polymer particles having the units A and B1 are dispersed in water.
According to the production method of this embodiment, the average particle diameter of the fluoropolymer particles contained in the aqueous dispersion can be easily controlled to 100 nm or less. Further, the zeta potential of the fluoropolymer can be easily controlled to 30 mV or more in absolute value. Therefore, the obtained aqueous dispersion is excellent in storage stability, and the water resistance of a coating film obtained using the aqueous dispersion is also excellent.
In the production method of the present embodiment, the amount of monomer 1 used is preferably 1.5 mol% or more, preferably 2 mol% or more, based on the total amount of monomers used for the polymerization of the fluoropolymer. Is more preferable. An upper limit in particular is not restrict | limited, Usually, it is 15 mol%, and 10 mol% is preferable at the point which the effect of this invention is more excellent.
In the production method of the present embodiment, the amount of the non-fluorinated anionic surfactant used is preferably 0.001 to 5% by mass with respect to the total mass of the monomers used for the polymerization of the fluoropolymer, 0.01 to 1.5% by mass is more preferable, and 0.1 to 0.4% by mass is particularly preferable.

The fluorine-containing coating composition of the present invention contains the aqueous dispersion of the present invention. The fluorine-containing coating composition of the present invention may contain a pigment, a curing agent, a curing aid, and other additives as necessary. Hereinafter, a component blended in the fluorine-containing coating composition is referred to as an additive.
The content of the aqueous dispersion in the fluorine-containing coating composition is preferably 10 to 80% by mass and more preferably 20 to 70% by mass with respect to the total mass of the coating composition. If the content of the aqueous dispersion is not less than the above lower limit value, the weather resistance of the coating film is more excellent, and if it is not more than the upper limit value, the film formability of the coating film is more excellent.
Examples of other additives include a film forming aid, a thickener, an antifoaming agent, a light stabilizer, a design agent, a surface conditioner, and an aqueous medium. An aqueous medium is used to dilute the aqueous dispersion.
Examples of the pigment include inorganic color pigments, organic color pigments, and extender pigments.

As the thickener, known thickeners can be used, such as urethane thickeners, polyacrylic thickeners, polyamide thickeners, cellulose thickeners, thickeners such as clay minerals such as bentonite. Agents can be used. Of these, urethane thickeners are preferred. The urethane thickener is a so-called associative thickener and has good compatibility with the fluoropolymer particles contained in the aqueous dispersion of the present invention. For this reason, the fluorine-containing coating composition containing a urethane-based thickener is unlikely to sag.
Examples of the urethane thickener (urethane associative thickener) include compounds having a urethane bond and a polyether chain in the molecule and a hydrophobic group at the terminal. It is known that a urethane-based thickener effectively exhibits a thickening action when urethane bonds are associated with each other in an aqueous medium. Specific examples of commercially available urethane thickeners include “UH-420”, “UH-450”, “UH-462”, “UH-472”, “UH-540”, “UH-752”. , “GT-1306” (all products of ADEKA Corporation), “SN thickener 612”, “SN thickener 621N”, “SN thickener 625N”, “SN thickener 627N”, “SN thickener 660T” (all San Nopco shares) Company products).
The content of the urethane thickener is preferably 0.01 to 3% by mass, more preferably 0.05 to 1% by mass, based on the total mass of the fluorine-containing coating composition.

In addition, when the thickener includes a thickener having a hydrophobic interaction (hereinafter, also simply referred to as “hydrophobic thickener”), the thixotropic property (viscosity change with time) is excellent. It is possible to prepare a coating composition. In the present specification, the thixotropic property is evaluated by a TI value measured with a B-type viscometer, and the TI value of the fluorine-containing coating composition of the present invention when a hydrophobic thickener is included is preferably 7 or less. 6 or less is more preferable. The lower limit is not particularly limited as long as the TI value exceeds 1.
A hydrophobic thickener is a compound having a hydrophilic group and a hydrophobic group in its molecular structure. The hydrophobic thickener exhibits a good balance between the cohesive force due to the hydrophobic group and the dispersive force due to the hydrophilic group in an aqueous dispersion which is a highly polar medium, and exhibits excellent thixotropy.
Examples of the hydrophilic group include a group having a hydroxyl group, a carboxy group, an amino group, a carbamate group, a urea group, an amide group, or a sulfo group. Part or all of the hydrophilicity in the hydrophobic thickener may form a salt (sodium salt, potassium salt, etc.).
Examples of the hydrophobic group include aliphatic hydrocarbon groups (alkyl groups, polyoxyalkylene alkyl groups, alkylene groups, polyoxyalkylene groups, etc.), aromatic hydrocarbon groups (phenyl groups, naphthyl groups, etc.), and fluorinated carbonization. And a hydrogen group (perfluoroalkyl group, perfluoro (polyoxyalkylenealkyl) group, perfluoro (polyoxyalkylene) group, etc.).
As the hydrophobic thickener, a (meth) acrylic acid thickener that is a copolymer of (meth) acrylic acid and a monomer having a hydrophobic group, a polyurethane thickener having a hydrophobic group, Urethane-urea thickener having a urethane chain in which at least a part of the main chain is composed of a hydrophobic group, and amide-urea thickening having an amide chain in which at least a part of the main chain is composed of a hydrophobic group Agents and the like. The hydrophobic thickener is preferably a (meth) acrylic thickener from the viewpoint of compatibility with the fluoropolymer in the aqueous dispersion.
The (meth) acrylic acid is preferably acrylic acid or methacrylic acid. Moreover, you may use acrylic acid amide and methacrylic acid amide.
Examples of the monomer having a hydrophobic group include styrene and alkyl (meth) acrylate.
Further, among all the units of the copolymer constituting the (meth) acrylic thickener, the unit derived from (meth) acrylic acid is preferably 10 to 90 mol%, and the monomer having a hydrophobic group The derived unit is preferably 10 to 90 mol%.
When the hydrophobic thickener is in the form of a polymer, its number average molecular weight (Mn) is not particularly limited, but is preferably 50,000 to 1,000,000.
Specific examples of the hydrophobic thickener include GT-1306 (urethane thickener: ADEKA), SN thickener (urethane thickener: San Nopco), BYK-425 (urea modified urethane thickener). Agent: BYK-Chemie), BYK-420 (urethane-urea thickener: BYK-Chemie), BYK-430 (amide-urea thickener: BYK-Chemie), SN thickener 660T SN thickener 665T (urethane-based thickener: manufactured by San Nopco), RHEOLATE 216 (urethane-urea-based thickener: manufactured by ELEMENTIS), Primal RM-12W, primal RM-895 (urethane-based thickener: Dow Chemical) Manufactured).
The content of the hydrophobic thickener in the fluorine-containing coating composition of the present invention is preferably 0.01 to 3.0% by mass, and 0.05 to 2.0% by mass with respect to the total mass of the fluorine-containing coating composition. % Is more preferable.

When the fluorine-containing polymer in the aqueous dispersion of the present invention has a crosslinkable group, the coating film is cured by including a curing agent in the fluorine-containing coating composition, and weather resistance, water resistance, chemical resistance, The physical properties of the coating such as heat resistance can be further improved.
Examples of the curing agent include blocked polyisocyanate compounds or emulsion dispersions thereof, melamine resins such as methylol melamine and butyl etherified methylol melamine, and urea resins such as methylol urea and butyl etherified methylol urea.
The content of the curing agent is preferably 0.1 to 50% by mass with respect to the total mass of the aqueous dispersion.
The fluorine-containing coating composition of the present invention may be a one-pack type or a two-pack type, but when a curing agent is included, it is a two-pack type, and both liquids are mixed immediately before use. Is preferred.

The coated article of the present invention comprises a substrate and a coating film formed on the substrate by the above-mentioned fluorine-containing coating composition (a coating formed on the substrate and formed using the above-mentioned fluorine-containing coating composition). Film). Hereinafter, the coating film formed from the fluorine-containing coating composition of the present invention is a cured coating film in the case of a composition containing a fluorinated polymer having a crosslinkable group and a curing agent that crosslinks the crosslinkable group. means. In the case of a composition containing a fluorinated polymer having a crosslinkable group and not containing a curing agent, the formed coating film may be a coating film containing a fluorinated polymer having a crosslinkable group.
As a base material, the base material which consists of a nonmetallic material and a metallic material is mentioned. Nonmetallic materials include organic materials such as resin, rubber, and wood, and inorganic materials such as concrete, glass, ceramics, and stone. Examples of the metal material include iron, iron alloy, aluminum, and aluminum alloy.
Examples of the base material include, in the case of building materials, building materials manufactured by high heat treatment of non-metallic raw materials such as clay, silica sand, limestone, and more specifically, glass plates, tiles, bricks, glass fiber reinforced. A cement board, an asbestos cement board, a wood piece cement board, a cement calcium silicate board, a gypsum slag board, etc. are mentioned. As a base material, it is not restricted to building materials, The below-mentioned various base materials are mentioned.
The thickness of the coating film is preferably 10 to 100 μm. If the thickness of a coating film is more than a lower limit, the blocking property of a coating film will be more excellent, and if it is below an upper limit, the weather resistance of a coating film will be more excellent. Moreover, as will be described later, the salt water resistance, water resistance and the like are more excellent.

The coated article can be produced, for example, by applying a fluorine-containing coating composition on the surface of a substrate and drying it to form a coating film. When the fluorine-containing coating composition contains a fluoropolymer having a crosslinkable group and a curing agent that crosslinks the crosslinkable group, the dried coating film is cured to obtain a cured coating film. Drying and curing may be performed continuously.
The fluorine-containing coating composition may be applied directly to the surface of the substrate, or may be applied after performing a known surface treatment (such as a base treatment) on the surface of the substrate. Furthermore, after forming an undercoat layer on the substrate, it may be applied onto the undercoat layer.
As a method for applying the fluorine-containing coating composition, a known method can be used, and examples thereof include a method using a coating apparatus such as a brush, a roller, dipping, a spray, a roll coater, a die coater, an applicator, and a spin coater.
The drying temperature and curing temperature after coating are preferably from room temperature to 300 ° C.

In addition, as one of the suitable aspects of the coating film in this invention, the coating film whose water contact angle is 60 degrees or less is mentioned. In particular, such a coating film is obtained when the unit B1 is contained in the fluoropolymer, and the content thereof is 1.5 mol% or more of the total units of the fluoropolymer.
Among these, from the viewpoint of improving the antifogging property, the water contact angle of the coating film is preferably 60 ° or less, more preferably 50 ° or less, and further preferably 40 ° or less. The lower limit is not particularly limited, but the water contact angle is preferably 1 ° or more.
As a method for measuring the water contact angle, a water droplet having a diameter of 1 to 2 mm is dropped on the coating film, and after 30 seconds, the water droplet is photographed with a video camera for image analysis. The water contact angle is twice the angle between the line connecting the apex and end point of the water droplet and the coating film.

Note that, as described above, when the fluorine-containing polymer in the coating film contains a predetermined amount of unit B1, the coating film is excellent in scratch resistance and chemical resistance. That is, even when the coating film is rubbed with a predetermined chemical, the water contact angle of the coating film is unlikely to decrease. This is because the unit B1 contributing to the reduction of the water contact angle is incorporated in the fluoropolymer, so that even if the coating film is rubbed, the hydrophilic component is difficult to peel off from the coating film. It is considered that the properties of the coating film are difficult to change (for example, the water contact angle is difficult to decrease).

When the coating film exhibits the water contact angle, the coated article can be used for various applications. For example, the coating film can be used to impart antifogging properties to articles such as mirrors and glass. That is, the coating film can be used as an antifogging film. Accordingly, the aqueous dispersion and the fluorine-containing coating composition can be suitably used as a fluorine-containing polymer water-soluble dispersion for forming an antifogging film and a fluorine-containing coating composition for forming an antifogging film, respectively.
In addition to the above, the coating film showing the water contact angle can also be used for fins of automobiles, outdoor units and the like, exterior building materials, and the like.

Further, when the fluorine-containing polymer contains a unit having a polyoxyalkylene chain in the side chain, for example, a fluorine-containing heavy containing a unit based on the monomer represented by the formula (1), unit A and unit B The fluorine-containing coating composition of the present invention (hereinafter also simply referred to as “specific coating”) in the case of a coalescence (hereinafter also simply referred to as “specific polymer”) can be applied to various uses. For example, the specific paint can be used as a marine organism adhesion prevention paint applied to the surface of a ship, a marine structure or an underwater structure in order to prevent marine organisms from adhering.
The present inventors have adsorbed or adsorbed biopolymers such as proteins or cells on a specific fluoropolymer or a cured product thereof in a coating film (hereinafter also referred to as “specific coating film”) formed from a specific paint. It has been found that it has an effect that it is difficult to adhere, and that marine organisms (shellfish such as barnacles, squirts, cell plastics, mussels and mussels, and algae such as aonori and aosa) are less likely to adhere.
The attachment of marine organisms is considered to occur when the marine organism considers the attachment object as a solid and determines that it is a suitable habitat environment. In the specific coating film, the side chain polyoxyalkylene chain of the specific polymer is oriented on the surface of the specific coating film, and at least a part of the surface of the specific coating film is caused by the interaction between the hydrophilic polyoxyalkylene chain and water. Is considered hydrated or swollen. Therefore, it is considered that marine organisms regard the specific coating film as water instead of solid and do not adhere to the specific coating film. That is, the specific coating film expresses a marine organism adhesion prevention mechanism.
Moreover, according to the specific paint, a coating film excellent in salt water resistance and weather resistance can be formed. That is, the specific coating film has excellent marine organism adhesion prevention properties over a long period of time, and also has excellent salt water resistance and weather resistance that can withstand environmental changes (air exposure, temperature changes, etc.).

The specific paint is preferably applied to the painting of a ship, an offshore structure or an underwater structure.
Ships, offshore structures or underwater structures that are objects to be painted are those used in the ocean (including nearby areas), such as bridges, fishing nets, wave-dissipating blocks, breakwaters, submarine cables, tanks, pipelines. , Submarine drilling equipment, marine floats, seawater intake and discharge outlets at seaside power plants, seawater piping (cooling water piping) at seaside power plants, ship hulls (especially ship bottoms and drafting parts), ship screws, ship dredging Etc. The material of the object may be any of metal, resin, rubber, stone, glass, and concrete.
Moreover, the shape and state (contact state with seawater) of the coating object are not particularly limited.
For example, seawater pipes (cooling water pipes) of coastal power plants that have bent shapes in the pipe shape and that can greatly change the flow velocity and temperature of seawater in the pipes have a coating film on the inner surface of the pipe. As a result, the marine organism adhesion preventing function and the anticorrosive property are expressed over a long period of time.

When a specific paint is used as the marine organism adhesion preventing paint, a compound having a marine organism adhesion preventing action can be contained in the specific paint as the additive. Examples of such additives include polyglycolic acid and silicone organic polymers. The specific paint containing polyglycolic acid or a silicone-based organic polymer is more suitable as the marine organism adhesion preventing paint described above.
The polyglycolic acid is preferably polyglycolic acid obtained by ring-opening polymerization of 70 to 100% by mass of glycolide and 30 to 0% by mass of another cyclic monomer.
The Mw (weight average molecular weight) of the polyglycolic acid is preferably 30,000 to 800,000, more preferably 50,000 to 300,000. The molecular weight distribution (Mw / Mn) of polyglycolic acid is preferably 1.5 to 4.0, and more preferably 1.8 to 2.5. The terminal carboxyl group concentration of polyglycolic acid is preferably ⁶ to 200 eq / 10 ⁶ g, and more preferably 10 to 80 eq / 10 ⁶ g.

Glycolide is a bimolecular cyclic ester of glycolic acid, which is a kind of hydroxylcarboxylic acid. The proportion of glycolide is preferably 80% by mass or more, more preferably 90% by mass or more, and further preferably 99% by mass or more.
Examples of other cyclic monomers include bimolecular cyclic esters of other hydroxycarboxylic acids such as lactide, lactones, trimethylene carbonate, 1,3-dioxane, and the like.
Specific examples of the polyglycolic acid include polyglycolic acid described in International Publication 2011/132537 pamphlet.
The content of polyglycolic acid is preferably 10 to 50% by mass with respect to the specific polymer.

The silicone-based organic polymer is preferably a polymer obtained by polymerizing a monomer composition containing an organosilicon-containing monomer.
The monomer composition comprises an organosilicon-containing monomer represented by the formula CH ₂ ═CR ^S1 C (O) O— (R ^S2 O) _n —Si (R ^S3 ) ₃ (hereinafter simply “monomer”). And a monomer other than the monomer S (hereinafter also simply referred to as “monomer R”).
The symbols in the formula represent the following meanings.
R ^S1 represents a hydrogen atom or a methyl group.
R ^S2 represents a divalent hydrocarbon group having 1 to 10 carbon atoms, preferably an alkylene group having 1 to 3 carbon atoms.
Three R ^{S3 s} may be the same or different and each represents a monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms.
n represents an integer of 0 to 10, and preferably an integer of 0 to 3.
The monomer R may be any monomer that can be copolymerized with the monomer S. For example, (meth) acrylic acids, vinyl esters, vinyl ethers, maleic esters, fumaric esters, croton Examples include acid esters, itaconic acid esters, citraconic acid esters, and vinyl monomers.

Examples of the polymer include polymers described in JP2010-235877A.
Specifically, in the monomer composition, the monomer includes 1 to 70% by mass of the monomer S in which n is 1 to 3 with respect to the total mass of all monomers, and the monomer in which n is 0 1 to 70% by mass of S, preferably 1 to 98% by mass of monomer R, and 5 to 20% of monomer S with n being 1 to 3 with respect to the total mass of all monomers. It is particularly preferable that it contains 40 to 70% by mass of the monomer S containing n% by weight and 20 to 50% by mass of the monomer R.
The content of the polymer is preferably 10 to 50% by mass with respect to the specific polymer.

Further, as described above, the specific polymer and the cured product thereof have an effect that a biopolymer such as a protein and a cell are hardly adsorbed or adhered, that is, an effect that a propagation nutrient source of mold or algae is difficult to adhere.
In other words, the specific coating itself forms an unsuitable environment for the growth of mold or algae, and has a fungicide / algae control mechanism that does not depend on the fungicidal action of the fungicide (preservative) or the algae. Yes. Therefore, the specific coating film has a low environmental load and can exhibit excellent antifungal and antialgal properties over a long period of time. In addition, the specific coating film has high water resistance (low water vapor permeability) and air shielding (low oxygen permeability) that prevent water from accumulating, and forms an environment that is not suitable for the growth of mold or algae. Yes. In other words, the specific coating film not only exhibits excellent antifungal and algal resistance over a long period of time, even in an environment where mold and algae are likely to be generated and propagated, such as in a wet or wet environment. Furthermore, it has excellent water resistance and weather resistance that can withstand environmental changes (air exposure, temperature changes, etc.).

As described above, the specific paint expresses a fungicide / algae control mechanism by the specific polymer itself, but may further contain a fungicide or an algae preventive from the viewpoint of further enhancing the effect.
Examples of the fungicide or the algae preventive include known fungicides or algae, and an agent containing a halogen atom-containing compound as an active ingredient is preferable from the viewpoint of compatibility with a specific polymer. When a specific polymer containing a chlorine atom (for example, a specific polymer in which the fluoroolefin is CF ₂ ═CFCl) is used, a compound having a chlorine atom, a bromine atom, or an iodine atom is used as an active ingredient. Agents are preferred.
The content of the fungicide or the algae is preferably 0.01 to 5% by mass with respect to the specific polymer.

Specific paints are applied to the coating of articles used in wet or wet environments. In the present specification, the wet environment means an environment having a humidity of 40% or more, and the wetted environment means an environment that is always in contact with water or sometimes in contact with water.
Articles used in wet or wet environments include, for example, bathtubs, ceiling panels, wall panels, floor pans, doors, faucets, drainage units, ventilation fans, mirrors, sinks, toilets, low tanks, hand-washers, etc. Indoor structures around water, underground structures such as water pipes and sewage pipes, outdoor structures such as water storage tanks and buildings. The material of the article may be any of metal, resin, rubber, stone, glass, and concrete.

The specific coating film should just be formed in the outermost surface of the articles | goods exposed to a wet environment or a wet-contact environment. That is, the specific paint may be applied directly to the surface of the article, or may be applied to the outermost surface via the undercoat layer.
In addition, even if the article on which the specific coating film is placed is an article in a shading environment such as the outer wall of the north and west buildings with poor sunlight, the inner surface of the water storage tank, the water pipe, and the sewage pipe, Articles having a specific coating film on the surface due to the above-mentioned mold / algae-proof mechanism are excellent in mold-proof / algae-proof properties over a long period of time and have a low environmental load.

Furthermore, the specific paint can be used for purposes other than the paint. For example, a composition obtained by blending a specific paint with a flame retardant can also be used as a flame retardant treatment for wood or the like. Specifically, wood can be flame-retardant by impregnating the wood with the flame retardant agent.
The reason why such an effect is obtained is that the particle diameter of the fluoropolymer particles is small, so that the particles easily penetrate into the wood together with the flame retardant, and the specific polymer has a polyoxyalkylene chain in the side chain. Because it has high affinity with wood (cellulose), the retention rate of particles in wood is high, water resistance and weather resistance derived from a specific polymer can be imparted to the wood, and the specific polymer is wood The point that a preservative effect can be given to is mentioned.
Examples of the flame retardant include brominated flame retardants such as tetrabromobisphenol A, decabromobiphenyl, and pentabromodiphenyl ether, chlorinated flame retardants such as chloroparaffin and chloropolyethylene, and phosphorous flame retardants such as phosphate esters and ammonium polyphosphate. Examples of the flame retardant include boron-based flame retardants such as sodium polyborate, borax, and zinc borate.
The content of the flame retardant is preferably 20 to 30% by mass with respect to the specific polymer.

When the wood is impregnated with the flame retardant treatment agent, the wood may be in either a humidity-controlled state or a saturated state, and the moisture content of the wood is preferably adjusted to 10 to 50% by weight in advance.
Moreover, as a method of impregnating wood with the flame retardant treatment agent, it is preferable to immerse the flame retardant treatment agent in wood using a reduced pressure or pressure injection method.

Hereinafter, the present invention will be described in detail with reference to examples. However, the present invention is not limited to these examples.
The evaluation methods and materials used in each example are shown below.

[Measurement and evaluation method of aqueous dispersion]
(Measurement method of average particle size)
The particle diameter of the fluoropolymer particles in the aqueous dispersion was measured by a dynamic light scattering method using ELS-8000 (manufactured by Otsuka Electronics Co., Ltd.), and the value of D50 was taken as the average particle diameter.
(Measurement method of zeta potential)
The zeta potential of the fluoropolymer particles in the aqueous dispersion was measured by electrophoretic light scattering using ELS-8000 (manufactured by Otsuka Electronics Co., Ltd.).
(Measuring method of aggregate ratio)
The aggregate remaining on the mesh when the aqueous dispersion was filtered through a metal mesh (aperture 74 μm) was dried, and the aggregate ratio was calculated by the following formula.
Aggregate ratio = Aggregate amount (mass) / Fluoropolymer amount (mass) × 100
(Storage stability)
The storage stability of the aqueous dispersion was evaluated by the following test.
50 cc of the aqueous dispersion was placed in a centrifuge tube and allowed to stand at room temperature for 2 weeks. The amount of sediment (fluorinated polymer particles) settled on the bottom of the centrifuge tube was read from a scale and evaluated according to the following criteria.
A: 0 to 0.1 cc
○: More than 0.1 cc and less than 0.5 cc ×: 0.5 cc or more

[Evaluation of coating film]
(Preparation of test plate)
V-Selan (registered trademark) # 700 manufactured by Dainippon Paint Co., Ltd. was applied to the surface of a slate plate having a length of 120 mm, a width of 60 mm, and a thickness of 15 mm by air spray so that the dry film thickness was 20 μm. An undercoat film was formed by drying at 200 ° C. for 210 seconds.
Next, the fluorine-containing coating composition was applied onto the undercoat film by air spray so that the dry film thickness was 40 μm, and dried at 100 ° C. for 210 seconds to form a coating film, whereby a test plate was obtained. .
The obtained test plate was evaluated as follows.

(Water resistance evaluation 1)
The test plate was immersed in warm water at 60 ° C. for 18 hours, then immersed in cold water at 5 ° C. for 15 hours, and then dried at 5 ° C.
After drying, the appearance of the coating film was evaluated according to the following criteria.
○: No whitening or blistering was observed in an area of 80% or more of the coating surface.
X: Generation | occurrence | production of whitening and blistering was recognized in the area over 20% of the coating-film surface.

(Water resistance evaluation 2)
The test plate was immersed in warm water at 60 ° C. for 2 weeks and then dried at 5 ° C.
After drying, the appearance of the coating film was evaluated according to the following criteria.
○: No whitening or blistering was observed in an area of 80% or more of the coating surface.
(Triangle | delta): Generation | occurrence | production of whitening or blistering was not recognized in the area of 60 to 80% of the coating-film surface.
X: Generation | occurrence | production of whitening and blistering was recognized in the area over 40% of a coating-film surface.

(Anti-fogging evaluation)
The test plate was left to stand in a thermostatic bath at 98 ° C. and 50 ° C. for 3.5 minutes for testing.
The appearance was evaluated according to the following criteria.
○: No cloudiness was observed in an area of 80% or more of the coating surface.
X: Cloudiness was recognized in the area of more than 20% of the coating surface.

(Measurement method of water contact angle)
The water contact angle of the coating film in the test plate was measured by the following method.
Specifically, a water droplet having a diameter of 1 to 2 mm is dropped on the coating film in the test plate, and the water droplet after 30 seconds is photographed with a video camera and analyzed. The water contact angle of the coating film is defined as twice the angle between the line connecting the apex and end points of the water drop and the test plate.

(Liquid sag evaluation)
The fluorine-containing coating composition was applied to an aluminum plate made vertical by air spray, and the film thickness at which dripping occurred was examined. Evaluation was made according to the following criteria.
○: No dripping was observed even when the film thickness was 60 μm.
X: Liquid sagging was observed when the film thickness was less than 60 μm.

[Measurement method of TI value]
The viscosity of the fluorine-containing coating composition was measured with a B-type viscometer, and the TI value was calculated by the following formula. In addition, the temperature at the time of measurement of a fluorine-containing coating material composition was set to 23 degreeC.
TI value = (viscosity at 6 rpm) / (viscosity at 60 rpm)

[Materials used to produce aqueous dispersion]
CTFE: chlorotrifluoroethylene (Asahi Glass Co., Ltd.).
CHVE: cyclohexyl vinyl ether (manufactured by BASF).
EVE: Ethyl vinyl ether (manufactured by BASF).
CHMVE: 4-hydroxymethylcyclohexylmethyl vinyl ether (manufactured by BASF)
CM-15EOVE: CH ₂ ═CHOCH ₂ —cycloC ₆ H ₁₀ —CH ₂ O (CH ₂ CH ₂ O) _n1 H, n1: 15, average molecular weight 830 (manufactured by Nippon Emulsifier Co., Ltd.).
CM-10EOVE: CH ₂ ═CHOCH ₂ —cycloC ₆ H ₁₀ —CH ₂ O (CH ₂ CH ₂ O) _n2 H, n2: 10, average molecular weight 550 (manufactured by Nippon Emulsifier Co., Ltd.).
NL-100: polyoxyethylene alkyl ether (HLB: 13.8) (nonionic surfactant).
SLS: sodium lauryl sulfate (anionic surfactant) (manufactured by Nikko Chemicals Co., Ltd.).

[Materials used for production of fluorine-containing paint composition]
Film-forming aid: EHG manufactured by Nippon Emulsifier Co., Ltd.
Thickener: PRIMAL (registered trademark) TT-615 (polyacrylic thickener) manufactured by Rohm & Haas.
Antifoaming agent: Dehydran (registered trademark) 1620 manufactured by BASF Corporation.

[Example 1]
(Production of aqueous dispersion)
In an autoclave with a stirrer made of stainless steel having an internal volume of 2500 mL (manufactured by Pressure Glass Industrial Co., Ltd.), CHVE (181 g), EVE (185 g), CM-15EOOVE (176 g), ion-exchanged water (1031 g), potassium carbonate (1031 g) K ₂ CO ₃ ) (2.1 g), SLS (2.1 g), and ammonium persulfate (0.2 g) were charged, cooled with ice, and pressurized with nitrogen gas to 0.7 MPa and degassed. This pressure degassing was repeated twice, and after degassing to 0.01 MPa to remove dissolved air, CTFE (490 g) was charged and a polymerization reaction was performed at 60 ° C. for 24 hours.
After the polymerization reaction, the autoclave is cooled from 60 ° C. to 20 ° C., and an aqueous dispersion (D1) containing fluoropolymer particles (average particle size 69 nm, zeta potential −48 mV) having a solid content concentration of 49.7% by mass. Got.
The contents of units derived from CHVE, EVE, CM-15EOVE, and CTFE in the fluoropolymer were as shown in Table 1 below.

(Manufacture of fluorine-containing paint composition)
Add aqueous dispersion (D1) (80 g) obtained in Example 1, film-forming aid (6 g), thickener (0.4 g), antifoaming agent (0.6 g), ion-exchanged water (13 g) And mixed to obtain a fluorine-containing coating composition (1).

[Examples 2 to 4, Comparative Examples 1 to 3]
Aqueous dispersions (D2) to (D7) were obtained in the same manner as in Example 1 except that the amount of each component used was changed as shown in Table 1. Further, in the same manner as in Example 1 except that the aqueous dispersions (D2) to (D7) were used in place of the aqueous dispersion (D1), the fluorinated coating compositions (2) to (7) were prepared. Obtained.

The storage stability was evaluated using the aqueous dispersions (D1) to (D7). The results are shown in Table 1. In addition, using the fluorine-containing coating compositions (1) to (7), a test plate was prepared according to the procedure described above, water resistance evaluation (water resistance evaluation 1 and 2), antifogging evaluation, and water contact angle. The measurement method was performed. The results are shown in Table 1.
In Table 1, mol% in the “CTFE” column to the “CM-10EOVE” column in the “Content of fluoropolymer unit” column is the unit based on each monomer relative to the total units in the fluoropolymer. The content (mol%) is intended.
Moreover, wt% (mass%) of each component of the "other component" column in Table 1 represents the content ratio (mass%) of each component with respect to the total mass of the fluoropolymer.

As shown in Table 1, it was confirmed that the desired effect was obtained when the aqueous dispersion of the present invention was used. Moreover, in each Example, it was confirmed that the average particle diameter and zeta potential of the fluoropolymer particles are in a predetermined range as described above. Further, from the comparison between Examples 1 and 2 and 3, when the content of the unit based on the monomer represented by the formula (1) is 2 mol% or more of the total units of the fluoropolymer, It was confirmed that the storage stability was more excellent. Further, from the comparison between Examples 3 and 4, when the content of the anionic surfactant is within the range of 0.1% by mass or more and less than 0.5% by mass with respect to the total mass of the aqueous dispersion (implementation) Example 3) It was shown that the water resistance (water resistance evaluation 2) of the coating film when immersed for a long period of time was more excellent.
On the other hand, in Comparative Examples 1 and 2 in which the average particle diameter and the zeta potential of the particles are not within a predetermined range, the desired effect was not obtained. In addition, Comparative Examples 1 and 2 both correspond to the mode in which the anionic surfactant described in Patent Document 1 and the nonionic surfactant are used in combination. Moreover, in Comparative Example 3 in which neither an anionic surfactant nor a nonionic surfactant was used, the storage stability of the aqueous dispersion was poor.

[Example 5]
The fluorine-containing coating composition (8) was changed in the same manner as in Example 2 except that the thickener was changed to hydrophobic modified polyether urethane (trade name: Adecanol GT-1306, manufactured by ADEKA) (urethane thickener). )
In addition, using the obtained fluorine-containing coating composition (8), a test plate was prepared according to the procedure described above, and as a result of water resistance evaluation (water resistance evaluation 1 and 2) and antifogging evaluation, Example 2 and Similar results were obtained.

Liquid dripping was evaluated using the fluorine-containing paint compositions (2) and (8) obtained in the above examples. The results are shown in Table 2.

<Manufacture and evaluation of mirrors>
[Example 6]
Silver plating was applied to one side of a 3 mm thick glass substrate so that the thickness was 800 mg / m ² . Next, on the silver-plated film, a lead-free epoxy resin-based back coating for mirrors (manufactured by Dainippon Paint Co., Ltd., “SM product name COAT DF”) is applied so that the film thickness of the dried coating film becomes 60 μm. The film was applied with a curtain flow coater, and the coating film was cured in a drying oven at 180 ° C. Then, the mirror with a rust-proof cured coating film was obtained by cooling the glass plate which has the coating film in which the hardening process was performed with a cooling furnace.
Next, the fluorine-containing coating composition (1) obtained in Example 1 was applied to the surface of the glass substrate of the mirror with a rust-proof cured coating film so as to have a film thickness of 1 μm, and was then heated in an oven at 150 ° C. for 20 minutes. It was dried for a minute to form a coating film on the surface of the glass substrate to obtain a test mirror.
As a result of confirming the antifogging property of the obtained test mirror, it was confirmed that no fogging was observed on the surface of the glass substrate and excellent antifogging property was exhibited in a high humidity environment.
Further, 50 wipes of ethanol-containing Kimwipe were rubbed against the coating film. Thereafter, the coating film was washed with water. As a result of confirming the antifogging property using the test mirror having the obtained coating film in the same manner as described above, no fogging was observed on the surface of the glass substrate, and the chemical resistance was excellent. In addition, even when a commercially available shampoo or a commercially available toothpaste was used in place of the ethanol, no fogging was observed on the glass substrate surface.

[Example 7]
Fluorinated paint compositions (9) and (10) were obtained in the same manner as in Example 5 except that the type and content of the thickener were changed as shown in Table 3. BYK-420 (urethane-urea thickener: BYK-Chemie) and BYK-425 (urea-modified urethane thickener: BYK-Chemie) are hydrophobic thickeners.
Then, the TI values of the fluorine-containing coating compositions (8), (9) and (10) were measured, and a test plate was prepared in the same manner as in Example 1 to evaluate the antifogging property of the coating film. did. The results are shown in Table 3.

Japanese Patent Application No. 2015-247848 filed on December 18, 2015, Japanese Patent Application No. 2015-254094 filed on December 25, 2015, Japanese Patent Application filed on February 09, 2016 Application No. 2016-023026, Japanese Patent Application No. 2016-088145 filed on Apr. 26, 2016, Japanese Patent Application No. 2016-088454 filed on Apr. 26, 2016, and Application No. 24 Aug. 2016 The entire contents of the specification, claims and abstract of Japanese Patent Application No. 2016-163846, which are incorporated herein by reference, are incorporated herein by reference.

Claims (15)

1. A fluoropolymer particle having a unit based on a fluoroolefin and a unit based on a monomer having no fluorine atom, an anionic surfactant, and water,
   Contains no nonionic surfactant or contains an amount of 0.1% by weight or less based on the aqueous dispersion;
   The average particle diameter of the particles is 100 nm or less,
   The particle has a zeta potential of 30 mV or more in absolute value,
   An aqueous dispersion characterized by the above.
2. The aqueous dispersion according to claim 1, wherein the monomer having no fluorine atom comprises a monomer represented by the following formula (1).
   Formula (1): XYZ
   In formula (1), X represents a group having a radically polymerizable unsaturated group. Y represents a single bond or a divalent linking group. Z represents a hydrophilic group having a polyoxyalkylene chain represented by the formula — (C _m H _2m O) _n — (m represents an integer of 1 to 4. n represents an integer of 12 or more). To express.
3. The aqueous dispersion according to claim 2, wherein the polyoxyalkylene chain is a polyoxyethylene chain.
4. Content of the unit based on the monomer represented by said Formula (1) is 1.5 mol% or more with respect to all the units which the said fluoropolymer has, The Claim 2 or 3 Aqueous dispersion.
5. The aqueous dispersion according to any one of claims 1 to 4, wherein the anionic surfactant is a non-fluorinated anionic surfactant.
6. The anionic surfactant comprises at least one lipophilic group selected from the group consisting of an alkyl group and an aryl group, and at least one hydrophilic group selected from the group consisting of a sulfate group, a sulfate group, and a carboxylate group. The aqueous dispersion according to any one of claims 1 to 5, which is a salt of a compound having
7. The aqueous dispersion according to any one of claims 1 to 6, wherein the content of the anionic surfactant is 0.01% to 1.5% by mass with respect to the mass of the fluoropolymer. liquid.
8. In the presence of a nonionic surfactant and a non-fluorinated anionic surfactant, the fluoroolefin and the monomer represented by the following formula (1) are polymerized in water, Production of an aqueous dispersion characterized by obtaining an aqueous dispersion in which particles of a fluoropolymer having units based on a fluoroolefin and units based on a monomer represented by the following formula (1) are dispersed in water Method.
   Formula (1): XYZ
   In formula (1), X represents a radically polymerizable unsaturated group. Y represents a single bond or a divalent linking group. Z represents a hydrophilic group having a polyoxyalkylene chain represented by the formula — (C _m H _2m O) _n — (m represents an integer of 1 to 4. n represents an integer of 12 or more). To express.
9. The usage-amount of the monomer represented by said Formula (1) is 1.5 mol% or more with respect to the total amount of the substance of the monomer used for superposition | polymerization of the said fluoropolymer. The manufacturing method as described in.
10. The amount of the non-fluorinated anionic surfactant used is 0.01% to 1.5% by mass with respect to the total mass of monomers used for the polymerization of the fluoropolymer. Or the manufacturing method of 9.
11. The production method according to any one of claims 8 to 10, wherein an average particle diameter of the particles is 100 nm or less.
12. The production method according to any one of claims 8 to 11, wherein the particle has a zeta potential of 30 mV or more in absolute value.
13. A fluorine-containing paint composition comprising the aqueous dispersion according to any one of claims 1 to 7.
14. The fluorine-containing paint composition according to claim 13, further comprising a thickener.
15. A coated article having a base material and a coating film disposed on the base material and formed using the fluorine-containing coating composition according to claim 13 or 14.