JP2002256203A - Composition for water-based coating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorine-based composition for a water-based coating material, having excellent stability and film-forming properties as a dispersion, and capable of providing a coated film having improved blocking resistance, solvent resistance, weather resistance, waterproof properties, fouling resistance, transparency and adhesion. SOLUTION: This composition for the water-based coating material contains a fluorine-based copolymer comprising (a) a polymer unit based on a fluoroolefin, (b) a polymer unit based on propylene, (c) a polymer unit based on ethylene and/or (d) a polymer unit based on butylene, and (e) a polymer unit based on a vinyl monomer having a hydrolyzable silyl group, and having 40-150 deg.C melting point, and a curing catalyst such as an organotitanate compound and an organotin compound, dispersed in water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a composition for water-based paint.

[0002]

2. Description of the Related Art Conventionally, vinylidene fluoride resins have been widely used as baking type paints because they have good weather resistance, heat resistance and chemical resistance and are soluble in solvents at high temperatures. As this vinylidene fluoride resin, a vinylidene fluoride homopolymer or a copolymer of vinylidene fluoride and a fluoroolefin (tetrafluoroethylene, hexafluoropropylene, chlorotrifluoroethylene, etc.) has been proposed.

[0003] Copolymers of fluoroolefins with cyclohexyl vinyl ether and various other monomers are soluble in organic solvents at room temperature, and when used as coatings, have a high transparency and high gloss. It is known that a coating film having excellent properties such as weather resistance, water / oil repellency, stain resistance, and non-adhesion is provided (for example, see JP-A-55-4).
See No. 4083. ), And its use is increasing in the field of weather-resistant paints for interiors and exteriors of buildings and the like.

On the other hand, in recent years, from the viewpoint of environmental protection such as air pollution, the use of organic solvents has been increasingly regulated, and there has been an increasing social demand for aqueous paints and powder paints that do not use organic solvents.

[0005] From this viewpoint, fluororesins are also
A study has been made on aqueous dispersion, and in the case of vinylidene fluoride-based resin, a method of emulsion-polymerizing an acrylic monomer in the presence of vinylidene fluoride-based resin particles (see, for example,
See JP-A-8884, JP-A-4-325509 and the like. ) Has been proposed.

Aqueous dispersion of a copolymer of a fluoroolefin with cyclohexyl vinyl ether and other various monomers has been studied, and it has been reported that the copolymer can be produced by emulsion polymerization (for example, Japanese Patent Application Laid-Open No. 5
See JP-A-7-34107, JP-A-61-231044 and the like. ). Further, there has been proposed an aqueous dispersion in which a fluorinated copolymer containing a polymerized unit based on a macromonomer having a hydrophilic portion as an essential component is dispersed in water (for example, see JP-A-2-225550). ).
It is disclosed that this aqueous dispersion has excellent film-forming properties, good mechanical strength of a coating film, and can be produced without using an emulsifier or a hydrophilic organic solvent.

However, the stability of the aqueous dispersion of the vinylidene fluoride resin is not always good, and the transparency of the coating film is poor due to the crystallinity of the resin. When the crystallinity is lowered for improvement, there is a problem that the glass transition temperature of the coating film is too low and the stain resistance is deteriorated. These problems are alleviated by seed polymerization of acrylic monomers, but are not sufficient. There was also a problem in film forming properties. Further, the cost of the vinylidene fluoride-based resin increases because it is composed of only a fluoroolefin. Copolymers of fluoroolefins with cyclohexyl vinyl ether and other various monomers have good transparency and film forming properties and are sufficiently practical, but the monomers are relatively expensive. Further improvement was desired.

The present inventors have found that the above problems can be solved by an aqueous dispersion in which a fluoroolefin / ethylene / propylene copolymer and a (meth) acrylate copolymer are complexed. (See, for example, JP-A-2000-128934). Further, the present inventors, in the case of painting an article in a factory and performing heating and drying of the coating, if the coating film hardness is insufficient, by stacking the coated articles after drying, gloss reduction of the coating film, It has been found that scratches and the like occur, which causes uneven appearance. Further, in order to stack the coated articles efficiently, it is necessary to improve the coating efficiency, shorten the cooling time after heating and drying, and increase the number of stacked articles. Therefore, in order to increase the efficiency of commercialization of a coated article in a coating factory, it is necessary to increase the blocking resistance of the coating film so that no problem occurs in the stacking process.

[0009]

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems of the prior art, and is excellent in blocking resistance and water resistance of a coating film, as well as weather resistance and stain resistance. An object of the present invention is to provide a fluorine-based copolymer aqueous coating composition having excellent solvent resistance, adhesion, and transparency.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and according to the present invention, the following inventions are provided.

(1) (a) a polymerized unit based on a fluoroolefin, (b) a polymerized unit based on propylene,
A copolymer comprising (c) a polymerization unit based on ethylene and / or (d) a polymerization unit based on butylene, and (e) a polymerization unit based on a vinyl monomer having a hydrolyzable silyl group, A water-based coating composition, characterized in that a fluorine-based copolymer (A1) having a melting point in the range of 40 to 150 ° C and a curing catalyst (B) are dispersed in water.

(2) (a) a polymerized unit based on a fluoroolefin, (b) a polymerized unit based on propylene,
(C) a polymerization unit based on ethylene and / or (d) a polymerization unit based on butylene, (e) a polymerization unit based on a vinyl monomer having a hydrolyzable silyl group, and (f) a vinyl ester, a vinyl ether, or isopropenyl. A copolymer containing at least one polymer unit based on at least one selected from the group consisting of ether and allyl ether and / or (g) a polymer unit based on a macromonomer having a hydrophilic group, the melting point of which is 40 to 150 ° C. Wherein the fluorine-based copolymer (A2) and the curing catalyst (B) are dispersed in water.

(3) Fluorine containing (a) a polymerized unit based on a fluoroolefin, (b) a polymerized unit based on propylene, and (c) a polymerized unit based on ethylene and / or (d) a polymerized unit based on butylene. Copolymer (X1
(H) In the presence of 100 parts by mass of the particles of (A), (h) a (meth) alkyl ester of (meth) acrylic acid having 1 to 18 carbon atoms and (i) a hydrolyzable silyl group.
A composite particle (A3) obtained by emulsion polymerization of 5 to 100 parts by mass of a radical polymerizable monomer mixture (Y1A) containing an acrylate ester, and a curing catalyst (B) are dispersed in water. A composition for an aqueous coating composition, comprising:

(4) (a) polymerized units based on fluoroolefin, (b) polymerized units based on propylene,
(C) a polymerization unit based on ethylene and / or (d) a polymerization unit based on butylene, and (j) a polymerization unit based on a vinyl monomer having a reactive group that does not react with the hydrolyzable silyl group of the following (i). And a fluorine-containing copolymer (X2
(H) In the presence of 100 parts by mass of the particles of A), (h) an alkyl (meth) acrylate having 1 to 18 carbon atoms in the alkyl group, and (i) a (meth) acrylate having a hydrolyzable silyl group And (q) a (meth) acrylic acid and / or (meth) acryl having a reactive group other than a hydrolyzable silyl group capable of reacting with the reactive group of (j) to form a bond. A composite particle (A4) obtained by emulsion-polymerizing 5 to 100 parts by mass of a radical polymerizable monomer mixture (Y2A) containing an acid ester, and a curing catalyst (B) are dispersed in water. A composition for a water-based coating, comprising:

(5) The monomer mixture (Y2A) is
The above (4) further comprising (k) a (meth) acrylic ester having a hydrophilic group (excluding the above (q)).
The composition for an aqueous paint according to the above.

(6) The aqueous coating composition according to any one of (1) to (5), wherein the solid content in the composition is 10%.
An aqueous coating composition in which 0.1 to 100 parts by mass of an inorganic silicon compound and / or an organic silicon compound is blended with respect to 0 parts by mass.

(7) At least one selected from the group consisting of an ultraviolet absorber, a film-forming aid and a thickener is blended with the aqueous coating composition according to any one of the above (1) to (6). Aqueous paint compositions.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be described in detail. One of the features of the coating composition of the present invention, the fluorine-based copolymer particles constituting the composition,
As will be described later, whether the compound is complexed or used as it is, a hydrolyzable silyl group must be present in the final particle. Due to the presence of the hydrolyzable silyl group, it is activated by hydrolysis in an aqueous dispersion, and the bond (adhesion) between the coating film formed from the coating composition containing the same and the surface of an inorganic building material or the like. And the coating properties can be improved.

In the present invention, (a) a polymerized unit based on a fluoroolefin, (b) a polymerized unit based on propylene, (c) a polymerized unit based on ethylene, and / or (d) a polymerized unit based on butylene. And (e) a vinyl monomer having a hydrolyzable silyl group, and an aqueous dispersion of a fluorine-based copolymer (A1).

Here, it is preferable that the fluorine-based copolymer (A1) is constituted by a composition ratio of polymerized units based on the following monomers (hereinafter, may be indicated by the monomer names).
That is,

(A) 20-70 mol% of fluoroolefin, (b) 10-60 mol% of propylene, (c) ethylene (2)-(40) mol%, (d) butylene (2)-(40) mol % (E) 1 to 30 mol% of a vinyl monomer having a hydrolyzable silyl group.

This composition ratio is more preferably (a) 25 to 65 mol% of a fluoroolefin, (b) 12 to 55 mol% of propylene, (c) ethylene (3) to (35) mol%, and (d) butylene. (3) to (35) mol% (e) 2 to 25 mol% of a vinyl monomer having a hydrolyzable silyl group.

Most preferably, (a) 30 to 60 mol% of a fluoroolefin, (b) 14 to 50 mol% of propylene, (c) ethylene (4) to (30) mol%, (d) butylene (4) to (30) mol% (e) 3 to 20 mol% of a vinyl monomer having a hydrolyzable silyl group.

Here, the composition ratio of the polymerization units (c) ethylene and (d) butylene is shown in parentheses (40),
The notations (35), (30) and the like have the following meanings. That is, as specified in the claims, at least one of (c) and (d) is always included, and the other may not be included at all.
(35), (30) and the like indicate the content of the contained component (c) or (d) alone. In addition,
When both (c) and (d) are contained, (4)
0), (35), (30) and the like indicate the total content of both components.

If the proportion of the polymerized unit (a) based on the fluoroolefin in the present invention is too small, the weather resistance is inferior. If the proportion is too large, the cost becomes higher as compared with the improvement in the weather resistance. Not preferred. The above range is selected in consideration of these.

Also, polymerized units (b) based on propylene
If the proportion is too small, the melting point will be too high, and the flexibility of the coating film will be insufficient. If it is too large, the fluorocopolymer will be rubbery and the hardness of the coating film will be insufficient. Thus, the above range is selected.

As described above, both the polymerized unit (c) based on ethylene and the polymerized unit (d) based on butylene may be used together, or only one of them may be used. One must be used. If the proportion of (c) and / or (d) is too large, the melting point will be too high, and the crystallization of the coating film will be large and the transparency will be reduced. Conversely, if the amount is too small, the fluorocopolymer becomes rubbery and the hardness is insufficient. The above range is selected as preferable in consideration of these.

If the proportion of the polymerized unit (e) based on the vinyl monomer having a hydrolyzable silyl group is too large, the stability of the aqueous dispersion when polymerized is lowered. Adhesion of the coating film is insufficient. The above range is selected as preferable in consideration of these.

In the present invention, the fluoroolefin of (a) includes trifluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene, vinylidene fluoride, trifluoropropylene, tetrafluoropropylene, pentafluoropropylene, hexafluoropropylene, tetrafluoropropylene, A fluoroolefin having about 2 to 4 carbon atoms containing a fluorine atom, such as fluorobutylene and pentafluorobutylene, is preferred, and a perfluoroolefin is particularly preferred. Most preferably, it is tetrafluoroethylene. Note that other halogen atoms such as a chlorine atom may be contained together with the fluorine atom.

In the present invention, 1-butylene, 2-butylene and isobutylene can be used as butylene of (d). Of these, isobutylene is most preferable in terms of availability. Further, a mixture thereof may be used.

In the present invention, examples of the vinyl monomer having a hydrolyzable silyl group (e) include the following (1) to
Vinyl ethers or isopropenyl ethers such as (4), vinyl silanes or isopropenyl silanes such as the following (5) to (8), and acrylates or methacrylates such as the following (9). . In the following (1) to (9), x is an integer of 1 to 8, y is an integer of 0 or 1, and R ⁵ is 1 to 8 carbon atoms such as a methyl group, an ethyl group, and a propyl group. Wherein R ⁶ is a hydrogen atom or a methyl group, and R ⁷ is a methyl group.

[0032] _{(1) CH 2 = CHO (} CH 2) x Si (OR 5) 3 (2) CH 2 = CHO (CH 2) x Si (CH 3) (OR
⁵ ) ₂ (3) CH ₂ ＣC (CH ₃ ) O (CH ₂ ) _x Si (O
R ⁵ ) ₃ (4) CH ₂ ＣC (CH ₃ ) O (CH ₂ ) _x Si (C
H ₃ ) (OR ⁵ ) ₂ (5) CH ₂ ＣＨCHSi (OR ⁵ ) ₃ (6) CH ₂ ＣＨCHSi (CH ₃ ) (OR ⁵ ) ₂ (7) CH ₂ ＣC (CH ₃ ) Si (OR ⁵ ) ₃ (8) CH ₂ ＣC (CH ₃ ) Si (CH ₃ ) (OR ⁵ ) ₂ (9) CH ₂ ＣC (R ⁶ ) COO (CH ₂ ) _x Si
(R ⁷ ) _y (OR ⁵ ) _3-y

The melting point of the fluorine-based copolymer (A1 or A2 described below) in the present invention is from 40 to 150 ° C., preferably from 60 to 120 ° C. Further, the range of the melting point of the fluorine-based copolymer (X1A or X2A) described below is
40 to 150 ° C. is preferred, and particularly preferably 60 to 12 ° C.
0 ° C. If the melting point is too low, the hardness of the coating film will be insufficient. If the melting point is too high, sufficient fluidity will not be obtained at the time of heating and coating will impair the appearance of the coating film.

In the present invention, the fluorinated copolymer (hereinafter referred to as "the copolymer")
Unless otherwise specified, A1, A2, X1A and X2A are included. The range of the glass transition temperature is -20 ° C to 80 ° C.
And more preferably 0 to 70 ° C. If the glass transition temperature is too low, the hardness of the coating film is insufficient, and if it is too high, sufficient fluidity cannot be obtained at the time of heating coating, and the appearance of the coating film is impaired.

The melting point was measured by a scanning differential calorimeter (DS).
The exothermic peak when the sample was heated at 10 ° C./min was determined by C), and the temperature at that time was determined as the melting point. In the case where the distribution of the melting point peaks was wide, the lowest point of the downwardly convex portion was defined as the melting point. The glass transition temperature was defined as the point where two tangents intersect at a portion where a rapid change in the temperature gradient occurs in the DSC temperature rise curve.

The Q value as an index of the molecular weight of the fluorocopolymer in the present invention is preferably in the range of 0.1 to 10,000. More preferably 1 to 1000,
More preferably, it is 10 to 500. When the Q value is less than 0.1, the fluidity of the particles tends to decrease, and the film forming property and the smoothness of the coating film tend to decrease. If it exceeds 10,000, the mechanical strength of the coating film is impaired.

The Q value is determined by filling a cylinder having an inner diameter of 11.3 mm with a fluorine-based copolymer using a Koka type flow tester, and applying a diameter of 2.1 mm at 140 ° C. and a load of 68.6 N.
It is a value defined by the volume (mm ³ / sec) that is extruded from a 8.0 mm long nozzle and extruded per unit time.

The range of the particle size of the fluorine-based copolymer in the present invention is preferably from 50 nm to 300 nm, more preferably from 70 to 200 nm. If the particle size is less than 50 nm, mechanical stability tends to decrease, and film-forming properties tend to decrease. If it is larger than 300 nm, sedimentation stability, thermal stability, mechanical stability, and chemical stability are impaired. However, if it is less than 10% by mass, particles having a particle diameter outside this range may be mixed.

The particle size is an average particle size measured using a laser light scattering particle size measuring device (ELS-3000, manufactured by Otsuka Electronics Co., Ltd.).

The content of fluorine atoms in the fluorine-based copolymer in the present invention is preferably in the range of 20 to 65% by mass, and more preferably 30 to 60% by mass. If the content of the fluorine atom is too small, the weather resistance will be reduced, and if it is too large, the adhesion of the coating film to the substrate will be reduced.

The fluorine-based copolymer in the present invention may further comprise, in addition to the above-mentioned polymerized units based on the monomers (a) to (e),
(F) A copolymer (A2) containing a polymerized unit based on at least one monomer selected from the group consisting of vinyl ester, vinyl ether, isopropenyl ether and allyl ether may be used. When the (f) polymerized unit based on a monomer such as a vinyl ester is contained, not only the pigment dispersibility and the adhesion to the substrate are further improved, but also the affinity with the acrylic monomer is improved. It has the characteristic that the transparency and weather resistance of the coating film are improved.

If the amount of the polymerized units based on the monomer (f) such as vinyl ester is too large, the coating film becomes tacky,
On the other hand, if the amount is too small, the effect of improving the pigment dispersibility, the adhesion to the substrate, the affinity with the acrylic monomer, etc. is not sufficiently exhibited. Therefore, the content of the polymerized unit based on the (f) monomer is preferably about 5 to 20 mol%.

Examples of the vinyl ester include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pivalate, vinyl caproate, vinyl caprylate, vinyl stearate and the like. Examples of the vinyl ether include methyl vinyl ether, ethyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, and cyclohexyl vinyl ether.
Examples of the isopropenyl ether include methyl isopropenyl ether, ethyl isopropenyl ether, isopropyl isopropenyl ether, n-butyl isopropenyl ether, and cyclohexyl isopropenyl ether. Examples of the allyl ether include ethyl allyl ether, isopropyl allyl ether, n-butyl allyl ether, isobutyl allyl ether, and the like.

The fluorine-based copolymer of the present invention further comprises (g) a hydrophilic group in addition to the polymerized units based on the monomers (a) to (e) or (a) to (f). It may be a copolymer (A2) containing a polymerized unit based on a macromonomer (hereinafter sometimes abbreviated as a hydrophilic macromonomer).

When the polymer units (g) based on the hydrophilic macromonomer are contained, not only the mechanical stability and chemical stability of the aqueous dispersion of the present invention are improved, but also the film-forming properties and coating properties are improved. The film has excellent mechanical strength, and further has little or no use of an emulsifier for stabilization, thereby improving water resistance and stain resistance.

The macromonomer is a low molecular weight polymer or oligomer having a radically polymerizable unsaturated group in the molecule or at one end. That is, it is a compound having a radical polymerizable unsaturated group in the molecule or at one end and having at least four repeating units such as the following oxyethylene units in order to obtain sufficient aqueous dispersion stability. A compound having a radically polymerizable unsaturated group at one terminal is preferred because of its high polymerization reactivity. Although it depends on the type of the repeating unit, usually, a unit having 50 or less repeating units is preferably employed from the viewpoint of polymerizability, water resistance and the like.

The molecular weight of (g) the hydrophilic macromonomer is 250 or more. When the molecular weight is less than 250, the effect of stably dispersing the particles in water becomes insufficient.

Here, the radical polymerizable unsaturated group includes a vinyl group (CH ₂ ＝ CH—) and an allyl group (CH ₂ ＣC
HCH ₂ —), propenyl group (CH ₃ CH ＝ CH—), isopropenyl group (CH ₂ ＣC (CH ₃ ) —), acryloyl group (CH ₂ ＣＨCHCO—), methacryloyl group (CH ₂
ＣC (CH ₃ ) CO—), an alkenyl group (—CH ＝ CH)
−) And the like. In particular, one having a vinyl ether type or allyl ether type at one end is preferable.

As the hydrophilic group, a nonionic hydrophilic group is desirable. Polyoxyethylene chains (chains of oxyethylene units) or polyoxypropylene / polyoxyethylene chains (chains of oxyethylene units and oxypropylene units as appropriate) ) Is particularly preferable.

For example, (10) CH ₂ = CHOCH ₂ -cyclo-C ₆ H ₁₀ -CH ₂ O (CH ₂ CH ₂ O) _t X (where t is an integer of 4 to 40, and X is hydrogen atom,
It represents a lower alkyl group or a lower acyl group. )

(11) CH ₂ = CHO-RO- (CH ₂ CH ₂ O) _t X (where t and X have the same meanings as described above. R is a divalent carbon having 2 to 15 carbon atoms.) Represents a hydrogen group.)

[0052] _{(12) CH 2 = CHO-} RO- (CH 2 CH (CH 3) O) u -CH 2
_{O (CH 2 CH 2 O)} t X ( where, u is .R represents an integer of 1 to 10, t, X have the same meanings as defined above.)

(13) CH_Two= CHCH_TwoO-R-O- (CH_TwoCH (CH_Three) O)_u-
CH_TwoO (CH_TwoCH_TwoO)_tX (where R, u, t, and X have the same meanings as above)
You. ) Are exemplified. (-Cyclo-C₆H_Ten-) Result
There are 1,4-, 1,3-, 1,2-
Usually, 1,4- is adopted.

Above all, (g) a hydrophilic macromonomer having a vinyl ether type structure at one end is preferable because of its excellent alternating copolymerizability with fluoroolefin and good weather resistance of the copolymer coating film. For example, the following are exemplified.

(14) CH ₂ = CHOCH ₂ -cyclo-C ₆ H ₁₀ -CH ₂ O- (CH ₂ CH ₂ O) _n H (15) CH ₂ = CHO-C ₄ H ₈ -O- (CH _{2 CH 2 O) n H (16} ) CH 2 = CHO-C 4 H 8 -O- (CH 2 CH (CH 3) O) m -CH 2 O (CH 2 CH
₂ O) _n H In the above formulas (14), (15) and (16), m represents an integer of 1 to 10, and n represents an integer of 4 to 40.

These hydrophilic macromonomers (g) can be prepared by, for example, polymerizing formaldehyde with an alkyl vinyl ether or alkyl allyl ether having a hydroxyl group, or subjecting a compound having an alkylene oxide or lactone ring to ring-opening polymerization. Can be manufactured. It can also be produced by introducing a vinyl ether group, an allyl ether group or the like into the terminal of a hydrophilic polymer such as polyethylene glycol.

The fluorinated copolymer (A2) in the present invention
It is desirable that the polymer units (g) based on the hydrophilic macromonomer are contained in a proportion of 0.1 to 25 mol%, preferably 0.3 to 20 mol%. When the content of the polymerized unit based on the hydrophilic macromonomer is too small, the mechanical stability and the chemical stability of the aqueous dispersion cannot be remarkably improved. However, it is not preferable because the water resistance decreases.

In the present invention, by incorporating (j) a vinyl monomer having a reactive group into a fluorine-based copolymer as a base, a complexing treatment as described later is carried out to make the coating film transparent. It can also improve the performance. However,
The reactive group in (j) does not react with the hydrolyzable silyl group of (i) below.

The vinyl monomer having a reactive group (j) preferably has at least one functional group selected from the group consisting of a carboxyl group, an epoxy group and an amino group. Since the carboxyl group or amino group contained in the polymer has weak activity, the following (i)
Is not expected to react with the hydrolyzable silyl group.

The vinyl monomer having a carboxyl group as the above (j) includes acrylic acid, methacrylic acid,
Crotonic acid, isocrotonic acid, 10-undecenoic acid, 9
Monomers having a carboxyl group such as unsaturated fatty acids such as octadecenoic acid (oleic acid), fumaric acid, and maleic acid; and carboxylic acid group-containing monomers represented by the following formulas (17) and (18). Is exemplified.

[0061] ^{_{(17) CH 2 = CHOR 1}} OCOR 2 COOM (18) CH 2 = CHCH in ₂ OR ³ OCOR ⁴ COOM (formula, R ^1, R ³ is a divalent hydrocarbon group having from 2 to 15 carbon atoms R ² and R ⁴ are a saturated or unsaturated linear or cyclic divalent hydrocarbon group, and M is a hydrogen atom, a hydrocarbon group, an alkali metal or a nitrogen atom-containing group.)

Examples of the vinyl monomer having an epoxy group as (j) include epoxy group-containing alkyl vinyl ethers such as glycidyl vinyl ether; epoxy group-containing alkyl allyl ethers such as glycidyl allyl ether; glycidyl acrylate and glycidyl. Examples include an epoxy group-containing alkyl acrylate such as methacrylate or methacrylate.

Examples of the vinyl monomer having an amino group (j) include diethylaminoethyl (meth) acrylate and dimethylaminoethyl (meth) acrylate.

The proportion of the vinyl monomer having a reactive group (j) is preferably 0.1 to 30 mol%. If the content is too large, it becomes unstable at the time of polymerization. If the content is too small, the effect of transparency by the compounding treatment is small.

The fluorinated copolymer in the present invention is one dispersed in water. Here, the water-based coating composition of the present invention basically has excellent dispersion stability without using an emulsifier usually used in a water-based coating composition of a fluorine-based copolymer. It is not excluded.

As the emulsifier, a commonly used nonionic emulsifier or anionic emulsifier can be used alone or in combination.

The above-mentioned emulsifier is usually added and used at the time of polymerization, but the same kind of emulsifier and / or different kinds of emulsifier may be added to the aqueous dispersion after polymerization.

In the present invention, the initiation of emulsion polymerization is carried out by adding a polymerization initiator in the same manner as in the usual initiation of emulsion polymerization. As the polymerization initiator, a usual radical initiator can be used, and particularly, a water-soluble initiator is preferably employed. Specifically, persulfates such as ammonium persulfate; hydrogen peroxide; Sodium, redox initiators in combination with reducing agents such as sodium thiosulfate;
Inorganic initiator in the presence of silver sulfate or the like; or dibasic acid peroxide such as disuccinic peroxide or diglutaric peroxide; or organic initiator such as azobisisobutylamidine hydrochloride or azobisisobutyronitrile Agents are exemplified.

The amount of the polymerization initiator to be used can be appropriately changed depending on the kind thereof, emulsion polymerization conditions and the like, but is usually 0.005 to 100 parts by mass of the monomer to be emulsion-polymerized.
About 0.5 part by mass is preferred. Further, these polymerization initiators may be added all at once, or may be added in portions as needed.

For the purpose of increasing the pH of the emulsion, p
An H adjuster may be used. Examples of the pH adjusting agent 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. Is exemplified.

The amount of the pH adjuster is usually about 0.05 to 2 parts by weight, preferably about 0.1 to 2 parts by weight, per 100 parts by weight of the emulsion polymerization medium.

The starting temperature of the emulsion polymerization is selected as appropriate depending on the type of the polymerization initiator.
A temperature of 100 ° C, especially about 10 to 90 ° C, is preferably employed. The polymerization temperature is about 20 to 120 ° C. The reaction pressure can be appropriately selected, but is usually 0.1 to 10 M
It is desirable to adopt Pa, especially about 0.2 to 5 MPa.

In the emulsion polymerization of the present invention, additives such as a monomer, water, an emulsifier, a polymerization initiator and the like may be charged as they are, and polymerization may be carried out. For the purpose of improving various properties such as stability and gloss of the coating film, the emulsion may be pre-emulsified using a stirrer such as a homogenizer before the polymerization initiator is added, and then the initiator may be added and polymerized. . Further, the method of charging the monomer is a method of charging the entire amount of the monomer at a time, a method of continuously charging the entire amount of the monomer, and a method of charging the entire amount of the monomer separately. Various methods can be adopted, such as a method, a method in which a part of the monomer is charged and reacted first, and then the remaining is divided or continuously charged. In the case of divisional addition, the monomer composition may be different.

The fluorocopolymer in the present invention is obtained by further emulsifying a monomer having the same combination and composition as the particles in the presence of particles of the fluorocopolymer previously polymerized. It may be polymerized. By pre-existing copolymer particles in water in this way, gaseous monomers are easily absorbed, and the polymerization rate is improved. In this case, the stability of the dispersion liquid can be further improved by performing emulsion polymerization after diluting the particles of the fluorine-based copolymer that has been polymerized in advance.

In this case, it is desirable to carry out the polymerization at a ratio of 100 to 10,000 parts by mass of the monomer mixture with respect to 100 parts by mass of the fluorine-based copolymer particles previously charged at the time of the polymerization. If the ratio of the particles of the fluorine-based copolymer to be charged in advance is too small, the effect of improving the polymerization rate is small, and if it is too large, the yield of the aqueous dispersion obtained by one polymerization operation is reduced, which is not economical.

To further improve the gas absorption of the gaseous monomer into the aqueous dispersion, alcohols such as methanol, ethanol, isopropanol, n-butyl alcohol, isobutyl alcohol and t-butyl alcohol; A hydrophilic organic compound such as an alkylene glycol such as glycol or propylene glycol may be added during polymerization. In this case, the addition amount is preferably about 0.1 to 10% by mass relative to the water of the aqueous dispersion. More preferably, it is 1 to 5% by mass.

If the addition amount is less than this, the gas absorption effect is small, and if it is too large, the viscosity of the aqueous dispersion increases, making it difficult to form a coating.

In the present invention, excellent coating film properties can be obtained by emulsion-polymerizing a monomer mixture mainly containing an alkyl (meth) acrylate or the like based on the above-mentioned fluorine-based copolymer. To give an aqueous dispersion of a fluorinated copolymer that imparts the following.

That is, first, as defined in claim 3, (a) a polymerized unit based on a fluoroolefin, (b) a polymerized unit based on propylene, and (c) a polymerized unit based on ethylene and / or Or (d) an alkyl (meth) acrylate having an alkyl group having 1 to 18 carbon atoms in the presence of 100 parts by mass of particles of a fluorocopolymer (X1A) containing (d) a polymerized unit based on butylene. A radically polymerizable monomer mixture (Y) containing an ester and (i) a (meth) acrylate ester having a hydrolyzable silyl group.
Emulsion polymerization of 5 to 100 parts by mass of 1A) to form composite particles (A
3) (The composite particles are also referred to as core-shell particles.)
It is assumed that.

Further, more preferably, a complex treatment of a fluorine-based copolymer / alkyl (meth) acrylate-based copolymer can be performed as described later. Here, the “composite treatment” means that the base fluoropolymer particles and the (meth) acrylate copolymer particles each contain a reactive group that can be bonded to each other, and are used during emulsion polymerization. This is a treatment in which part or all of the copolymers are bonded to each other to suppress phase separation.

The coating film formed by using the aqueous dispersion of the above-mentioned complexing treatment as a coating binder can be used in both polymerization and / or when the applied coating film is heated and the aqueous solvent is dried and removed. It is believed that the reactive groups of the coalescence create additional bonds and fuse strongly. Therefore, while maintaining the properties such as weather resistance of the base fluorocopolymer, the transparency of the coating film,
The mechanical strength and the like can be further improved.

As described above, by subjecting the particles of the fluorine-based copolymer as the base to the complexing treatment with (meth) acrylic acid ester or the like, the mechanical properties of the fluorine-based copolymer such as weather resistance are maintained. Stability, chemical stability, film forming property, transparency, pigment dispersibility, and workability can be further improved. It is also effective in that blocking resistance is improved.

That is, secondly, as defined in claim 4, (a) a polymerized unit based on a fluoroolefin, (b) a polymerized unit based on propylene, (c) a polymerized unit based on ethylene, and / or A fluorine-based copolymer (X2A) containing (d) a polymerized unit based on butylene, and (j) a polymerized unit based on a vinyl monomer having a reactive group that does not react with the hydrolyzable silyl group of the following (i). One of the particles
(H) an alkyl group having 1 carbon atom in the presence of 00 parts by mass;
To (18) alkyl (meth) acrylates, (i)
(Meth) acrylic acid ester having a hydrolyzable silyl group, and (q) having a reactive group other than the hydrolyzable silyl group capable of reacting with the reactive group of (j) to form a bond. , (Meth) acrylic acid and / or (meth) acrylic acid ester, from 5 to 100 parts by mass of a radically polymerizable monomer mixture (Y2A) by emulsion polymerization to form composite particles (A4). .

In the present invention, the monomer mixture (Y
2A) may further contain (k) a (meth) acrylic acid ester having a hydrophilic group (however, excluding the above (q)).

The proportion of the monomer mixture (Y1A or Y2A) is determined based on the fluorine-based copolymer (X1A or X1A) used as the base.
5 to 100 parts by mass, preferably 10 to 80 parts by mass, more preferably 20 parts by mass per 100 parts by mass of the particles of 2A).
５０50 parts by mass. Therefore, in order to obtain the composite particles (A3 or A4), 5 to 100 parts by mass of the above (h) is added to the reaction vessel in the presence of 100 parts by mass of the base fluorocopolymer (X1A or X2A). ), A monomer mixture (Y1A or Y2A) mainly containing (meth) acrylic acid alkyl ester or the like may be charged and emulsion polymerization may be performed.

Here, the alkyl (meth) acrylate (h) has an alkyl group having 1 to 18 carbon atoms.
For example, methyl (meth) acrylate,
Ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate,
N-Amyl (meth) acrylate, isoamyl (meth) acrylate, n-hexyl (meth) acrylate, (meth)
Examples thereof include isohexyl acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, and cyclohexyl (meth) acrylate. Among them, in particular, an alkyl group having 1 to 5 carbon atoms (meth)
Acrylic esters are preferred.

The preferred ratio of (h) in the monomer mixture (Y1A or Y2A) is 20 to 95% by mass. More preferably, the content is 30 to 80% by mass. (H)
If the ratio is too small, the weather resistance and gloss of the coating film will be poor, and if it is too large, the transparency and mechanical strength of the coating film will tend to be poor.

As the (i) (meth) acrylate having a hydrolyzable silyl group, the above-mentioned formula (9)
Is preferred. Specifically, γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, γ- (meth) acryloxypropyldimethoxysilane, γ- (meth) acryloxypropyltriisosilane And propenyloxysilane.

The preferred ratio of (i) in the monomer mixture (Y1A or Y2A) is 1 to 60% by mass. More preferably, it is 5 to 50% by mass. If the proportion of (i) is too small, the adhesion of the coating film will be insufficient, and the crosslinking will be insufficient, resulting in poor solvent resistance and the like. If too large, the stability of the emulsion and the weather resistance of the coating film will tend to be poor. is there.

(Q) (meth) acrylic acid and / or (meth) having a reactive group other than a hydrolyzable silyl group capable of reacting with the reactive group of (j) to form a bond. As the acrylate, a (meth) acrylate having at least one reactive group selected from the group consisting of a carboxyl group, an epoxy group (glycidyl group) and an amino group can be used.

Examples of (q) include (meth) acrylic acid, 2-carboxyethyl (meth) acrylic acid, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, and the like.

Since the above (q) reacts with the reactive group of the above (j) to form a bond, it is preferably used in a ratio of 0.5 to 5 times the number of moles of the above (j). desirable. In particular, a ratio of 0.8 to 4 times is preferable. Further, a preferable ratio of the (q) in the monomer mixture (Y2A) is 1 to 6
0% by mass. More preferably, it is 5 to 50% by mass.

As the hydrophilic group of (k) a (meth) acrylate having a hydrophilic group (excluding the above (q)), a nonionic hydrophilic group is usually preferable.
Among them, polyoxyethylene chains or polyoxypropylene /
A nonionic hydrophilic group comprising a polyoxyethylene chain or the like is preferred. In (k), the number of repeating units in the polyoxyethylene chain, polyoxypropylene / polyoxyethylene chain or the like as a hydrophilic group is 4 or more and 50 or more.
It is preferable that the number is not more than the number from the viewpoint of polymerizability and durability.
Specific examples of the (k) include, for example, NK-ester M90G (trade name: manufactured by Shin-Nakamura Chemical Co., Ltd.).

The preferred proportion of the (k) in the monomer mixture (Y2A) is 0.1 to 20% by mass.
More preferably, it is 0.5 to 15% by mass. If the proportion of (k) is too small, the stability of the aqueous dispersion will be poor, and if it is too large, the water resistance of the coating will tend to be poor.

In order to improve the gloss of the coating film,
Along with the above (h) to (k), other monomers copolymerizable with the above (h) to (k), for example, aromatic vinyl compounds such as styrene and α-methylstyrene, (meth) acrylonitrile, An amide compound such as (meth) acrylamide may be used in an amount of 50% by mass or less, preferably 30% by mass or less based on the monomer mixture (Y1A or Y2A).

The conditions for the emulsion polymerization of the monomer mixture (Y1A or Y2A) can be adopted according to the conditions for the emulsion polymerization for the above-mentioned fluorine-based copolymer (A1 or A2).

The composite particles (A3 or A4) in the present invention
Is preferably in the range of 40 to 150 ° C, more preferably 60 to 120 ° C. If the melting point is too low, the hardness of the coating film will be insufficient. If the melting point is too high, sufficient fluidity will not be obtained at the time of heating and the appearance of the coating film will be impaired.

The glass transition temperature of the composite particles (A3 or A4) is preferably in the range of -20 ° C to 80 ° C, more preferably 0 ° C to 70 ° C. If the glass transition temperature is too low, the film will be tacky, and if it is too high, the flexibility of the film will be impaired.

The Q value as an index of the molecular weight of the composite particles (A3 or A4) is preferably in the range of 0.1 to 10,000. More preferably, it is 1 to 1000, and still more preferably 10 to 500. Q value is 0.1
If it is less than 1, the fluidity of the particles tends to decrease, and the film forming property and the smoothness of the coating film tend to decrease. If it is more than 10,000, the mechanical strength of the coating film will be impaired.

The average particle size of the composite particles (A3 or A4) is preferably in the range of 50 nm to 300 nm. More preferably, it is 70 to 200 nm. When the particle diameter is less than 50 nm, mechanical stability is reduced,
Also, the film-forming properties tend to decrease. If it is larger than 300 nm, sedimentation stability, thermal stability, mechanical stability, and chemical stability are impaired. However, if it is less than 30% by mass, particles having a particle diameter outside this range may be present.

The aqueous coating composition of the present invention is obtained by mixing a curing catalyst (B) with an aqueous dispersion of the above-mentioned fluorine-based copolymer (A1 or A2) or the above-mentioned composite particles (A3 or A4). It is.

In the present invention, the curing catalyst (B) refers to a curing catalyst obtained by a condensation reaction of the hydrolyzable silyl groups in the fluorocopolymer (A1 or A2) or the composite particles (A3 or A4). Such compounds include organometallic compounds and compounds containing a phosphorus atom or a sulfur atom in the molecule. For example, organic titanate compounds such as isopropyl tri (isostearoyl) titanate and isopropyl tri (dioctyl pyrophosphate) titanate; Tin compounds; phosphate compounds such as monooctyl phosphate and dioctyl phosphate; and sulfonic acid compounds such as dodecylbenzenesulfonic acid and paratoluenesulfonic acid.

In addition to the curing catalyst (B), an appropriate amount of an inorganic acid is added to the coating composition of the present invention when used to adjust the pH of the emulsion to an acidic range of about 3 to 5. If it is, a coating film with further improved crosslinkability can be formed.

In the present invention, the compounding amount of the curing catalyst (B) is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the fluorocopolymer (A1 or A2). The amount is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the particles (A3 or A4).

When the coating composition of the present invention is used as a coating base to form a coating composition, it adheres to an inorganic or organic substrate to be coated, weather resistance, and chemical resistance. In order to further improve the stain resistance in addition to the properties and film forming properties, the aqueous coating composition according to any one of the above (1) to (5) may be added to an inorganic silicon compound and / or an organic silicon compound (hereinafter, referred to as an organic silicon compound). , An inorganic / organic silicon compound). Examples of such inorganic silicon compounds include water-soluble silicates such as water glass and water-dispersible colloidal silica.

Examples of the water-soluble silicate include those represented by the following formula (I): T ₂ O · kSiO ₂ (I) (where T is an alkali metal or N (CH ₂ CH ₂ O)
_{H) 4, -N (CH 2} OH) 4, -N (CH 2 CH 2 OH) 3
Alternatively, it is —C (NH ₂ ) ₂ NH, and k is 0.5 to 5. )). The water-soluble silicate may or may not have water of crystallization.

Examples of the colloidal silica include, for example, sodium removal from water glass (ion exchange method, acid decomposition method,
Peptization), and the primary particle diameter is 4 to
It has a thickness of 150 nm, preferably 5 to 50 nm, and is usually supplied as an aqueous dispersion, which can be used as it is in the present invention. (For example, Snowtex-O or Snowtex 20: manufactured by Nissan Chemical Industries, Ltd.)

As specific examples of the organosilicon compound, for example, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane and the like are preferable.

The ratio of the solid content of the fluorine-based copolymer or the like in the water-based coating composition of the present invention to the inorganic / organic silicon compound to be blended is 100 parts by mass of the solid / inorganic / organic silicon compound. The silicon compound is preferably 0.1 to 100 parts by mass.
More preferably, it is in the range of 1 to 50 parts by mass. When the ratio of the inorganic / organic silicon compound is less than 0.1, the non-staining property of the surface of the obtained coating film may be insufficient, and 1
When it exceeds 00, defects such as cracks are liable to occur in the coating film due to lack of flexibility at the time of forming the coating film or over time.

The water-based paint composition of the present invention can be used as a water-based paint as it is as a paint binder. However, if necessary, a coloring agent, a plasticizer, an ultraviolet absorber, an ultraviolet stabilizer, a leveling agent, an antifoaming agent, Additives usually added to aqueous paints, such as a pigment dispersant, a thickener, an anti-cissing agent, an anti-burr agent, and a curing agent, may be appropriately selected and mixed. Furthermore,
A metallic pigment such as an aluminum paste may be used.

In the present invention, the aqueous coating composition according to any one of the above (1) to (6),
A water-based coating composition containing at least one selected from the group consisting of a film-forming aid and a thickener can be exemplified as a preferable one.

Examples of the coloring agent include dyes, organic pigments, inorganic pigments and the like. Examples of the plasticizer include conventionally known plasticizers, for example, low molecular weight plasticizers such as dioctyl phthalate, and high molecular weight plasticizers such as vinyl polymer plasticizers and polyester plasticizers.

Examples of ultraviolet absorbers include 2-hydroxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-5-chlorobenzophenone,
2-aminobenzophenone, high molecular weight modified bensophenone (for example, trade name: T-5, manufactured by Adeka Argus Co., Ltd.)
Benzophenones such as 7); 2- (2′-hydroxy-)
5′-t-butylphenyl) benzotriazole, 2-
(2′-hydroxy-5′-t-butylphenyl) -5
-Chlorobenzotriazole, 2- (2'-hydroxy-5'-methoxyphenyl) benzotriazole, 2-
Benzotriazoles such as (2'-hydroxy-3 ', 5'-dineopentylphenyl) benzotriazole and high molecular weight modified benzotriazole (for example, trade names: Tinuvin 900, Tinuvin 1130, manufactured by Ciba Specialty Chemicals) And the like.

As the ultraviolet stabilizer, a high molecular weight modified hindered amine (for example, trade name: MARK LA 57, 62, 63, 67, 6 manufactured by Adeka Argus Co., Ltd.)
8), Tinuvin 292 (trade name) manufactured by Ciba Specialty Chemicals, and the like.

Examples of a film-forming auxiliary include dipropylene glycol-n-butyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether,
Polyhydric alcohol monoalkyl ethers such as diethylene glycol monobutyl ether and organic acid esters are used.

Examples of the thickener include cellulose thickeners represented by hydroxyethylcellulose, carboxymethylcellulose, etc., urethane thickeners, and polycarboxylic acid thickeners.

In order to improve the stability of the aqueous coating composition of the present invention, sodium carbonate, potassium carbonate,
A pH adjuster such as sodium orthophosphate, triethylamine and triethanolamine may be added.

[0118]

EXAMPLES The present invention will be specifically described below with reference to synthesis examples and examples, but the present invention is not limited to these examples and the like. The number of parts in the following examples indicates parts by mass unless otherwise specified, and% means mass%.

(Synthesis Example 1) (1) 1100 g of ion-exchanged water, 4.75 g of an anionic emulsifier (sodium lauryl sulfate), and a nonionic emulsifier (N-1110; Nippon Emulsifier Co., Ltd.) were placed in a 2 L stainless steel autoclave equipped with a stirrer. 24.7g and t-
39.8 g of butanol was charged, and air was removed by repeating deaeration with a vacuum pump and pressurization with nitrogen gas.
Next, (a) 70.4 g of tetrafluoroethylene,
8.3 g of (b) propylene, 1.1 g of (c) ethylene and 8.7 g of (e) γ-methacryloxypropyltrimethoxysilane were introduced into an autoclave.

(2) When the temperature in the autoclave reached 65 ° C., the pressure showed 2.42 MPa. Thereafter, 7 mL of a 30% aqueous solution of ammonium persulfate was added to start the reaction. (A) 59.1 mol% of tetrafluoroethylene,
(B) propylene 20.4 mol%, (c) ethylene 2
630 g of a 0.5 mol% mixed gas was continuously added to continue the reaction. Also, (e) 70 g of γ-methacryloxypropyltrimethoxysilane was added in five portions from a press-fit tube.

After 15 hours, the supply of the mixed gas was stopped, and the autoclave was cooled with water to reach room temperature. Then, the unreacted monomer was purged, and the autoclave was opened to release the solid content.
A 5% aqueous dispersion was obtained.

(3) The obtained aqueous dispersion was settled by a centrifugal separator, and the polymer was filtered through a glass filter.
After removing water for 5 hours under a reduced pressure of 32 Pa, the mixture was pulverized with an impact hammer mill to obtain a powder of a fluorine-based copolymer. The results of compositional analysis of this copolymer by ¹³ C-NMR were as follows: (a) 55 mol% of polymerized units based on tetrafluoroethylene, (b) 19 mol% of polymerized units based on propylene, and (c) polymerized units based on ethylene. 19 mol%,
(E) 7 mol% of polymerized units based on γ-methacryloxypropyltrimethoxysilane. The melting point is 10
1.2 ° C. Table 1 shows the results.

(Synthesis Example 2) (1) 1100 g of ion-exchanged water and potassium carbonate (K _{2) were} placed in a ₂ L stainless steel autoclave equipped with a stirrer.
3.2 parts of CO ₃ ), a nonionic emulsifier (N-1110;
20.7 parts of Nippon Emulsifier Co., Ltd., 7.3 g of an anionic emulsifier (sodium lauryl sulfate), t-butanol.
4 g, (e) 17.3 g of γ-methacryloxypropyltrimethoxysilane, and (f) 2.6 g of vinyl acetate were charged, and air was removed by repeating deaeration with a vacuum pump and pressurization with nitrogen gas. Next, (a) 69.2 g of tetrafluoroethylene, (b) 7.2 g of propylene, (c)
1.1 g of ethylene were introduced into the autoclave.

(2) When the temperature inside the autoclave reached 65 ° C., the pressure showed 2.35 MPa. Thereafter, 10 mL of a 30% aqueous solution of ammonium persulfate was added to start the reaction. While maintaining the pressure as the pressure drops,
630 g of a mixed gas of (a) 60 mol% of tetrafluoroethylene, (b) 29 mol% of propylene, and (c) 11 mol% of ethylene was continuously added, and the reaction was continued. Further, a mixed solution of (e) 184.5 g of γ-methacryloxypropyltrimethoxysilane and (f) 64 g of vinyl acetate was added in five portions through a press-fit tube.

(3) After 12 hours, the supply of the mixed gas was stopped, and the autoclave was cooled with water to reach room temperature. After that, unreacted monomers were purged, and the autoclave was opened to obtain a concentration of 37.
A 2% emulsion was obtained. The obtained emulsion is settled by a centrifugal separator, the polymer is filtered with a glass filter, and water is removed under reduced pressure of 532 Pa for 5 hours, and then pulverized with an impact hammer mill to obtain a powder of a fluorine-based copolymer. I got The results of composition analysis of this copolymer by ¹³ C-NMR were as follows: (a) 52 mol% of polymerized units based on tetrafluoroethylene, (b) 25 mol% of polymerized units based on propylene, and (c) polymerized units based on ethylene. 10
Mol%, (f) 5 mol% of polymerized units based on vinyl acetate,
(E) 8 mol% of polymerized units based on γ-methacryloxypropyltrimethoxysilane. The melting point is 61.
4 ° C. Table 1 shows the results.

(Synthesis Examples 3 to 6) The monomer compositions used in the emulsion polymerization were changed as shown in Table 1, and otherwise the aqueous dispersions of the fluorine-based copolymers were prepared according to the methods described in Synthesis Examples 1 and 2. Obtained.

(Synthesis Example 7) A 500-mL glass flask equipped with a thermometer, stirrer, reflux and condenser was prepared as shown in Table 1.
Was charged with 300 g of the aqueous dispersion obtained in Synthesis Example 4 (the amount of the fluorine-based copolymer in the dispersion was 116 g).
Heated to 0 ° C. When it reaches 80 ° C, (i)
γ-methacryloxypropyltrimethoxysilane 2.9
g, (h) 20.3 g of t-butyl methacrylate, (h)
5.8 g of methyl methacrylate, a nonionic emulsifier (N-
1110; 0.3 g of an anionic emulsifier (sodium lauryl sulfate), water 29.7
g of the aqueous dispersion was added dropwise over 1 hour. Immediately thereafter, 1 mL of a 2% aqueous solution of ammonium persulfate was added to start the reaction. After a reaction time of 3 hours, the temperature in the flask was raised to 90 ° C., and the reaction was further performed for 1 hour to complete the polymerization. The fluororesin and methacrylate polymer were mixed at 80:20.
In terms of (mass ratio), an aqueous dispersion having a solid content concentration of 39.2% was obtained. Table 2 shows the results.

(Synthesis Examples 8 to 12) An aqueous dispersion was obtained according to the method described in Synthesis Example 7 except that the monomer composition used in the emulsion polymerization was changed as shown in Table 2.

[0129]

[Table 1]

The abbreviations in Table 1 are as follows. _{EOVE: CH 2 = CHO-C} 4 H 8 -O- (CH 2 CH 2 O) n H ( average molecular weight 5
20),

[0131]

[Table 2]

In each composition, for example, the composition of tetrafluoroethylene “72/55” means that the composition “72” of the molecule is 72 mol% in the monomer of the raw material, and the denominator "55" indicates that the polymerization units based on tetrafluoroethylene in the copolymer are 55%.

Example 1 The hydrofluoric acid obtained according to Synthesis Example 1 was used.
71 parts of an aqueous dispersion of a silicone-based copolymer,
2 g of propyl triisostearoyl titanate, silicic acid
Lithium (SiO _Two/ Li_TwoO molar ratio 4.5: lithium lithium
3.5 g, film forming aid
5.4 g, thickener 0.3 g, dispersant 0.8 g, defoamer
0.6 g and ion-exchanged water 10.3 g for the amount shown in Table 2.
And a clear paint formulation. Note that the film-forming auxiliary is C
s-12 (manufactured by Chisso Corporation) and a thickener, Leobis CR (F
Kist Gosei Co., Ltd.), dispersant is Noscosperse 44-C
(Manufactured by San Nopco), antifoaming agent is FS Antifoam 9
0 (manufactured by Dow Corning).

(Examples 2 and 3) Coating was carried out in the same manner as in Example 1 except that the aqueous dispersions of the fluorocopolymer were obtained according to Synthesis Examples 2 and 3, respectively.

Comparative Example 1 Example 1 was repeated except that the aqueous dispersion of the fluorocopolymer was obtained according to Synthesis Example 4.
The paint was compounded in the same manner as described above.

Example 4 70 parts of an aqueous dispersion of the fluorine-based copolymer obtained in Synthesis Example 7, 2 g of dibutyltin dilaurate as a curing catalyst, colloidal silica (Snowtex C: manufactured by Nissan Chemical Industries, Ltd.) 5 g, film forming aid
4 g, thickener 0.3 g, dispersant 0.8 g, defoamer 0.6
g and 10.3 g of ion-exchanged water were used to formulate a clear paint. The film forming aid was butyl carbitol acetate, the thickener was Leobis CR (manufactured by Hoechst Gosei), the dispersant was Noscosperse 44-C (manufactured by San Nopco), and the antifoaming agent was FS Antifoam 90.
(Manufactured by Dow Corning).

(Examples 5 and 6) Coating was carried out in the same manner as in Example 4 except that the aqueous dispersions of the fluorocopolymer were obtained according to Synthesis Examples 8 and 9, respectively.

(Comparative Examples 2, 3, and 4) Coating was carried out in the same manner as in Example 4 except that the aqueous dispersion of the fluorine-based copolymer was obtained by Synthesis Examples 10, 11, and 12. Was.

(Coating Film Test) An acrylic emulsion primer (Bonflon aqueous primer S: manufactured by Asahi Glass Coat and Resin Co.) was applied to the slate plate with the paints obtained in Examples 1 to 6 and Comparative Examples 1 to 4. Air-spray on the painted test specimen to a dry film thickness of 40 μm.
It was dried at 0 ° C. for 40 minutes to obtain a test piece. These test pieces were tested for blocking resistance, solvent resistance, weather resistance, water resistance, stain resistance, adhesion and transparency. The test method was as follows.

Blocking resistance test: Two test pieces were superposed on each other and a load of 0.05 MPa was applied.
After standing for a period of time, the state of the coating film when the test piece was separated was observed. ○ indicates no change in the coating film surface, △ indicates that the coating film was partially damaged, and x indicates that the entire coating film was damaged.

Solvent resistance test: The state of the coating film when rubbed 50 times with gauze impregnated with xylene was observed.
○ indicates no change in the coating film surface, Δ indicates that the gloss of the coating film surface was reduced, and x indicates that the coating film was melted.

Evaluation of weather resistance: When the gloss was significantly reduced after 3000 hours of a QUV test using a fluorescent ultraviolet weathering tester manufactured by Q Panel Co., it was evaluated as x, and when the gloss was not significantly reduced, it was evaluated as ○.

Water resistance evaluation: After immersion in warm water at 60 ° C. for one week, the coating was evaluated for blistering or peeling. A sample without swelling or peeling was rated as "O", and a sample with swelling or the like was rated as "x".

Contamination resistance: Exposure was performed outdoors at 45 ° on the south side for 1 year.
Those exceeding 5 were evaluated as x.

Transparency: The test piece was heated at 200 ° C. for 10 minutes, and completely transparent when visually observed was evaluated as ○, slightly cloudy as Δ, and considerably cloudy as ×.

Adhesion: A tape peeling test was performed based on JIS K5400.剥離 indicates that no complete peeling was observed, △ indicates partial peeling, and x indicates fairly peeling. The results are shown in Tables 3 and 4.

[0147]

[Table 3]

[0148]

[Table 4]

[0149]

Industrial Applicability The composition for a water-based coating of a fluorocopolymer of the present invention is a coating film having excellent blocking resistance, solvent resistance, weather resistance, water resistance, stain resistance, adhesion, and transparency. Which is extremely useful as a weather-resistant water-based paint.

Since the fluorocopolymer composition of the present invention is basically based on a stable aqueous dispersion which does not use an organic solvent, it is subject to restrictions such as solvent regulations. And can be applied to a wide range of applications. For example, it is particularly useful for weather-resistant coating of exterior inorganic building materials such as glass, metal and cement.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08F 214/18 C08F 214/18 230/08 230/08 290/06 290/06 291/04 291/04 C09D 5/02 C09D 5/02 123/08 123/08 123/14 123/14 123/20 123/20 129/06 129/06 129/10 129/10 131/02 131/02 133/02 133/02 133 / 08 133/08 143/04 143/04 155/00 155/00 183/07 183/07 F term (reference) 4J011 PA64 PA66 PC02 PC06 4J026 AA12 AA13 AA14 AA26 AA31 AA47 AA63 AC06 AC25 AC34 BA27 BA43 BB03 BB04 DA04 DA07 DA14 DB04 DB08 DB14 DB24 FA04 GA09 4J027 AC03 AC04 AC07 BA02 BA04 BA07 CB02 CC02 CD08 4J038 CB081 CD091 CD101 CD121 CR062 GA02 GA03 GA06 GA07 GA09 GA10 GA12 GA15 HA446 HA466 HA486 JA34 JB38 JC13 JC23 JC34 MAC14 MA08 NA03 NA04 NA05 NA10 NA12 PA19 PB05 4J100 AA02R AA03Q AA04S AA05S AA06S AC24P AC25P AC26P AC28P AC31P AE09T AL08T AP16T BA77T CA06 DA24 JA01

Claims (7)

[Claims] 1. A polymerization unit based on (a) a fluoroolefin, (b) a polymerization unit based on propylene, (c) a polymerization unit based on ethylene and / or (d) a polymerization unit based on butylene, and (e) hydrolysis. A fluorine-containing copolymer (A1) having a melting point in the range of 40 to 150 ° C., and a curing catalyst (B). And (c) are dispersed in water. 2. Polymerized units based on (a) fluoroolefins, (b) polymerized units based on propylene, (c) polymerized units based on ethylene and / or (d) polymerized units based on butylene, (e) hydrolysable A polymerized unit based on a vinyl monomer having a silyl group, and (f) a vinyl ester;
A copolymer containing at least one polymer unit based on at least one selected from the group consisting of vinyl ether, isopropenyl ether and allyl ether, and / or (g) a polymer unit based on a macromonomer having a hydrophilic group, and having a melting point of Fluorine-based copolymer (A in the range of 40 to 150 ° C)
2) and a curing catalyst (B) are dispersed in water. 3. A polymerized unit based on (a) a fluoroolefin, (b) a polymerized unit based on propylene, and (c)
In the presence of 100 parts by mass of particles of a fluorocopolymer (X1A) containing a polymerized unit based on ethylene and / or a polymerized unit based on (d) butylene, (h) the alkyl group has 1 to 18 carbon atoms. Emulsion polymerization of 5 to 100 parts by mass of a radically polymerizable monomer mixture (Y1A) containing the (meth) acrylic acid alkyl ester and (i) a (meth) acrylic acid ester having a hydrolyzable silyl group. An aqueous coating composition, wherein the obtained composite particles (A3) and the curing catalyst (B) are dispersed in water. 4. A polymerized unit based on (a) a fluoroolefin, (b) a polymerized unit based on propylene, (c) a polymerized unit based on ethylene and / or (d) a polymerized unit based on butylene, and (j) (h) alkyl in the presence of 100 parts by mass of particles of a fluorocopolymer (X2A) containing a polymerized unit based on a vinyl monomer having a reactive group that does not react with the hydrolyzable silyl group of (i). An alkyl (meth) acrylate having 1 to 18 carbon atoms in the group,
(I) a (meth) acrylic acid ester having a hydrolyzable silyl group, and (q) a reactivity other than the hydrolyzable silyl group capable of reacting with the reactive group of (j) to form a bond. Composite particles (A4) obtained by emulsion polymerization of 5 to 100 parts by mass of a radically polymerizable monomer mixture (Y2A) containing a (meth) acrylic acid and / or a (meth) acrylic acid ester having a group. And a curing catalyst (B)
And (A) are dispersed in water. 5. The aqueous solution according to claim 4, wherein the monomer mixture (Y2A) further contains (k) a (meth) acrylate ester having a hydrophilic group (excluding the (q)). Compositions for paints. 6. The aqueous coating composition according to claim 1, wherein the amount of the inorganic silicon compound and / or the organic silicon compound is 0.1 to 100 parts by mass of the solid content in the composition. A composition for water-based paint in which about 100 parts by mass are blended. 7. A water-based paint in which at least one selected from the group consisting of an ultraviolet absorber, a film-forming aid and a thickener is blended with the water-based paint composition according to any one of claims 1 to 6. Composition.