JP2964561B2 - Composition for paint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a coating material mainly composed of a vinylidene fluoride copolymer and an acrylic resin having excellent weather resistance of a coating film and being compatible with an acrylic resin. Composition.

[Problems to be Solved by the Prior Art / Invention] Homopolymer of vinylidene fluoride (hereinafter referred to as PVDF)
As is well known, is excellent in weather resistance, chemical resistance, corrosion resistance, and the like, and has good mechanical properties and workability, and is therefore widely used in molded articles, films, paints, and the like. In particular, in paints, it is used as a blend with a methyl methacrylate copolymer having good compatibility with PVDF in order to improve the light transmission.

However, because of the high crystallinity, the solvent capable of dissolving PVDF is limited to solvents having extremely high polarities such as N, N-dimethylformamide and N, N-dimethylacetamide and having a high boiling point. Use is limited. That is, at present, organosol dispersion-type and powder-type paints in which PVDF is dispersed in water or an organic solvent are commercially available, but both require high-temperature treatment for fixing after painting.

In recent years, an alternating copolymer of chlorotrifluoroethylene or tetrafluoroethylene and vinyl ether or vinyl ester, a polymer containing a crosslinkable functional group in a portion of vinyl ether, has been improved in ordinary temperature at room temperature. It has begun to be used as a curable fluororesin coating (Japanese Patent Publication No. 60-21686, Japanese Patent Application Laid-Open No. 59-102962). However, although this type of paint has improved workability, there remains a problem that weather resistance, stain resistance, corrosion resistance, and the like are not necessarily better than PVDF-based paint.

An object of the present invention is to provide a coating composition comprising a vinylidene fluoride copolymer and an acrylic resin, which has excellent weather resistance and stain resistance, and gives a coating film having good gloss. .

[Means for Solving the Problems] The present inventors have intensively studied to modify PVDF to obtain a copolymer which is soluble in a general-purpose solvent for coating and can be cured by reaction. As a result, surprisingly, even a hydrocarbon-based vinyl ether or vinyl ester monomer, which had been difficult to copolymerize with vinylidene fluoride monomer, was polymerized so as to have a specific composition range. In this case, the copolymer easily copolymerizes, and when the vinyl ether or vinyl ester monomer has a specific functional group, the obtained copolymer has excellent weather resistance, stain resistance and PVDF possessed by PVDF. It was found that the copolymer was imparted with reaction curability without lowering the corrosion resistance, and that it was also excellent in compatibility with general-purpose acrylic resins.This vinylidene fluoride copolymer and acrylic resin Consisting of Forming substance is found that it is possible to improve the adhesion and stain resistance to the fluororesin alone is a disadvantage in the case of the base material, thereby achieving the present invention.

The present invention relates to (A) 50 to 90 mol% of a structural unit represented by the general formula (I): -CH ₂ -CF _2- (I), (Wherein X represents a fluorine atom, a chlorine atom, a hydrogen atom or a trifluoromethyl group)
30 mol%, general formula (III): (Wherein R ¹ represents an alkylene group having 2 to 10 carbon atoms) 1 to 30 mol% of a structural unit represented by the following general formula (IV): (Wherein R ² represents an aromatic group or an alkyl group having 1 to 10 carbon atoms), 1 to 30 mol% of a structural unit represented by the following formula, and 0 to 30 mol% of a copolymerizable monomer (V) The present invention relates to a coating composition comprising a vinylidene fluoride copolymer comprising (A) and an acrylic resin (B).

[Actions and Examples] The vinylidene fluoride copolymer (A) of the present invention comprises structural units represented by the general formulas (I) to (IV), and may contain other structural units (V) as necessary. The number average molecular weight is preferably from 1000 to 500,000, more preferably from 3,000 to 50,000, measured by gel permeation chromatography (GPC), and measured at 30 ° C. using tetrahydrofuran (THF) as a solvent. Intrinsic viscosity [η]
Is preferably in the range of 0.01 to 2.0 dl / g. If the molecular weight of the copolymer is too large, solvent solubility tends to be poor,
If it is too small, the strength of the coating film tends to decrease, and cracks tend to occur. Further, the glass transition temperature of the copolymer is preferably in the range of -40 to 100 ° C. When the glass transition temperature is too low, when used as a coating, the coating film hardness tends to decrease, and when too high, the flexibility tends to decrease.

The structural unit represented by the general formula (I): —CH ₂ —CF ₂ — (I) in the copolymer (A) is a compound having a weather resistance of the obtained copolymer,
Stain resistance, corrosion resistance, chemical resistance etc. comparable to PVDF or PVDF
In particular, when the composition for a coating containing the copolymer is used for a coating, it is a component used for improving the obtained coating and coating film performance. The proportion of this unit in the copolymer is 50 to 90 mol%, preferably 60 to 80 mol%
It is. If this proportion exceeds 90 mol%, the solvent solubility of the copolymer and the gloss of the resulting coating film become insufficient, and the
The weather resistance, chemical resistance,
Corrosion resistance and stain resistance are reduced.

General formula (II) in the copolymer (A): The structural unit represented by the formula (wherein X is the same as described above) is a component used for improving the polymerization reactivity at the time of synthesizing the copolymer or improving the solvent solubility of the copolymer.
The proportion of this unit in the copolymer is 1 to 30 mol%, preferably 5 to 20 mol%. If this proportion exceeds 30 mol%, the compatibility with the acrylic resin will be reduced, and if it is less than 1 mol%, the polymerization reaction rate will be slow and the molecular weight of the copolymer will be reduced.

General formula (III) in the copolymer (A): (Wherein R ¹ is the same as described above) is a component used for imparting a property of being cured by a reaction to the copolymer and eventually to the paint. The proportion of this unit in the copolymer is 1 to 30 mol%, preferably 5 to 20 mol%.
When the proportion exceeds 30 mol%, when the copolymer is blended with a curing agent, the composition is liable to crosslink, and the storage stability of the curing composition containing the copolymer becomes poor, and the proportion is less than 1 mol%. On the contrary, the curability decreases. When R ¹ is not the above-mentioned alkylene group, for example, a methylene group has poor curability, and an alkylene group having more than 10 carbon atoms has poor weather resistance. Specific examples of the -R ¹ OH, for example, 2-
A hydroxyl-containing group such as hydroxyethyl, 3-hydroxypropyl, 2-hydroxypropyl, 2-hydroxy-2-methylpropyl, 4-hydroxybutyl, 4-hydroxy-2-methylbutyl, 5-hydroxypentyl, or 6-hydroxyhexyl; can give.

General formula (IV) in the copolymer (A): The structural unit represented by the formula (wherein R ² is the same as described above) is a component used to increase the compatibility with the curing agent that reacts with the —OH group of the structural unit represented by the general formula (III). In addition, the solvent solubility of the copolymer is also improved, and ethyl acetate, butyl acetate, isobutyl acetate, ester solvents such as cellosolve acetate, acetone, methyl ethyl ketone, will be well dissolved in ketone solvents such as methyl isopropyl ketone, As a diluting solvent for these good solvents, aromatic hydrocarbon solvents such as toluene and xylene can be used. The proportion of this unit in the copolymer is from 1 to 30.
Mol%, preferably 3 to 20 mol%. This ratio is 30
It is difficult to obtain a copolymer having more than mol% due to poor copolymerization reactivity of the monomers of the structural units (I) and (II), and the weather resistance and chemical resistance of the copolymer are low. , Corrosion resistance,
When the content is less than 1 mol%, it is difficult to be compatible with the curing agent, and the amount of the solvent capable of dissolving the copolymer is reduced, which is limited. Specific examples of R ² include, for example, aromatic groups such as phenyl, p-methylphenyl, p-tert-butylphenyl, phenethyl and benzyl, and cyclic groups having 10 or less carbon atoms such as cyclohexyl, cyclopentyl, cycloheptyl and cyclooctyl. Alkyl group, methyl, ethyl, n-propyl, isopropyl,
n-butyl, isobutyl, tert-butyl, pentyl, hexyl, 2-methylhexyl, 2-ethylhexyl,
Straight-chain or branched alkyl groups having 1 to 10 carbon atoms, such as -methylhexyl and 2,2-dimethylhexyl.

Wherein Among R ^2, for example tert- butyl, 1-methyl-1-propyl butyl, 1-methyl-1-ethylpentyl, 1,1-dimethyl-hexyl, 1,1-dimethyl-heptyl, 1-methyl-1- Ethylhexyl, 1-methyl-1
The carbon next to the carbonyl group such as -propylpentyl is 4
Grade carbon groups are preferred because they can easily increase the polymerization rate when synthesizing the copolymer. Further, a methyl group, an ethyl group, or an n-propyl group is preferable in that the degree of polymerization can be easily increased during the synthesis of the copolymer.

When R ² is not the above-mentioned group, for example, in the case of an alkyl group having more than 10 carbon atoms, the polymerization reaction rate is reduced and the polymerization rate is reduced.

The copolymer (A) may contain two or more structural units represented by general formulas (II) to (IV).

In the copolymer (A), in addition to the structural units represented by the general formulas (I) to (IV), a range not deteriorating the physical properties of the copolymer, preferably 0 to 30 mol% in the copolymer. Other structural units (V) copolymerizable in the range may be included. Examples of other structural units include units derived from a copolymerizable monomer described below.

Next, a method for producing the vinylidene fluoride copolymer (A) will be described.

The copolymer includes, for example, vinylidene fluoride providing a structural unit represented by the general formula (I), and one or more fluoroolefin monomers providing a structural unit represented by the general formula (II); One or more vinyl ether monomers containing an -OH group, which is a monomer giving a structural unit represented by the general formula (III),
By radical copolymerization of one or more carboxylic acid vinyl ester monomers, which are monomers giving the structural unit represented by the formula, and, if necessary, a monomer copolymerizable therewith. You can get.

Among the monomers used for the copolymerization, general formula (II)
Specific examples of the fluoroolefin monomer which becomes the structural unit represented by are tetrafluoroethylene, chlorotrifluoroethylene, trifluoroethylene, and hexafluoropropylene.

Specific examples of the vinyl ether monomer which becomes the structural unit represented by the general formula (III) include, for example, 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 2-hydroxypropyl vinyl ether,
2-hydroxy-2-methylpropyl vinyl ether,
4-hydroxybutyl vinyl ether, 4-hydroxy-2-methylbutyl vinyl ether, 5-hydroxypentyl vinyl ether, 6-hydroxyhexyl vinyl ether and the like.

Further, specific examples of the vinyl carboxylate monomer which is a structural unit represented by the general formula (IV) include, for example, aromatic vinyl esters such as vinyl benzoate and alkyl groups having 1 to 10 carbon atoms. Vinyl esters of aliphatic monocarboxylic acids and vinyl esters of cyclic aliphatic carboxylic acids such as vinyl cyclohexanecarboxylate. These are preferred monomers from the viewpoint of coating film hardness. Further, as described above, from the viewpoint of sufficiently increasing the polymerization rate of the copolymer, the carbon adjacent to the ester carbonyl group such as vinyl pivalate or vinyl versatate has a carbon number of 4%.
It is preferable to use vinyl esters which are grade carbon, vinyl acetate, vinyl propionate, and vinyl butyrate.

Other monomers (V) that can be copolymerized with the essential monomer components, if necessary, in addition to the essential monomer components
Examples thereof include methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, iso-butyl vinyl ether, tert-butyl vinyl ether, n-pentyl vinyl ether, n-hexyl vinyl ether, n-octyl vinyl ether, 2-ethylhexyl vinyl ether, 2-chloromethyl vinyl ether, and the like. Alkyl vinyl ethers; cycloalkyl vinyl ethers such as cyclopentyl vinyl ether, cyclohexyl vinyl ether, methylcyclohexyl vinyl ether, and cyclooctyl vinyl ether; vinyl ethers containing an aromatic group such as benzyl vinyl ether, phenethyl vinyl ether, and phenyl vinyl ether; 2,2,2-
Trifluoroethyl vinyl ether, 2,2,3,3-tetrafluoropropyl vinyl ether, 2,2,3,3,3-pentafluoropropyl vinyl ether, 2,2,3,3,4,4,5,5-
Octafluoropentyl vinyl ether, 2,2,3,3,4,4,
Fluoroalkyl vinyl ethers such as 5,5,6,6,7,7,8,8,9,9-hexadecafluorononyl vinyl ether, perfluoromethyl vinyl ether, perfluoroethyl vinyl ether and perfluoropropyl vinyl ether; and ethylene , Propylene, isobutylene,
Representative examples include vinyl chloride, vinylidene chloride, maleic anhydride, fumaric diesters, maleic diesters, and acrylonitrile. And
Among such copolymerizable monomers, it is preferable to use alkyl vinyl ethers and cycloalkyl vinyl ethers from the viewpoint of sufficiently increasing the polymerization rate.

The copolymerization is usually performed by an emulsion, suspension or solution polymerization method. The polymerization temperature is usually 0 in any polymerization method.
~ 150 ° C, preferably 5-95 ° C. The polymerization pressure is usually 1 to 100 kg / cm ² G in any polymerization method.

As the polymerization medium, water is used in the emulsion polymerization method, and water, tert-butyl alcohol, 1,1,2-trichloro-1,2,2-trifluoroethane, 1,2-dichloro-1 is used in the suspension polymerization method. , 1,2,2-tetrafluoroethane or a mixture thereof is used. In the solution polymerization method, esters such as methyl acetate, ethyl acetate, propyl acetate and butyl acetate, ketones such as acetone and methyl ethyl ketone, and mixtures thereof are used.

Examples of the polymerization initiator include a redox initiator comprising an oxidizing agent (eg, ammonium peroxide, potassium peroxide, etc.), a reducing agent (eg, sodium sulfite, etc.) and a transition metal (eg, iron sulfate, etc.) in the emulsion polymerization method, In the synthetic method and the solution polymerization method, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2-methylvaleronitrile), Azo compounds such as dimethyl 2'-azobis (2-cyclopropylpropionitrile) and 2,2'-azobisisobutyrate, and organic peroxides such as isobutyryl peroxide, octanoyl peroxide and diisopropyl-oxydicarbonate Is used.

In any polymerization method, hydrogen fluoride is desorbed from the monomer or the polymer during the polymerization, and the polymerization medium becomes acidic, and the polymer may be gelled. The desorbed hydrogen fluoride may be neutralized by adding sodium carbonate, potassium hydrogen carbonate, potassium carbonate, sodium phosphate, or the like.

Preferred specific examples of the vinylidene fluoride copolymer (A) include, for example, vinylidene fluoride (VdF) / tetrafluoroethylene (TFE) / vitroxybutyl vinyl ether (HBVE) / vinyl pivalate (VPi) copolymer, VdF
/ Chlorotrifluoroethylene (CTFE) / HBVE / VPi copolymer, VdF / TFE / HBVE / Veovar 10 (vinyl versatate, Veova-10 manufactured by Shell Chemical Co.), VdF / CTFE / HB
VE / Veova-10 copolymer, VdF / TFE / HBVE / vinyl acetate (VA
c) Copolymer, VdF / CTFE / HBVE / VAc copolymer, VdF / TFE / HB
VE / vinyl propionate (VPr) copolymer, VdF / CTFE / HBV
E / VPr copolymer, VdF / TFE / HBVE / vinyl butyrate (VBu) copolymer, VdF / CTFE / HBVE / VBu copolymer, VdF / hexafluoropropylene (HFP) / HBVE / VPi copolymer, VdF / HFP / HBVE
/ Veova-10 copolymer, VdF / HFP / HBVE / VAc copolymer, VdF /
HFP / HBVE / VPr copolymer, VdF / HFP / HBVE / VBu copolymer, Vd
F / TFE / HBVE / VPi / ethyl vinyl ether copolymer, VdF / C
Examples include TFE / HBVE / VPi / cyclohexyl vinyl ether copolymer, but are not limited thereto, and may include two or more types of each of the structural units (II) to (V).

The copolymer (A) may be used alone or in combination of two or more.

The copolymer (A) prepared by each of the above polymerization methods can be used as a lacquer type paint as it is, but when used together with the acrylic resin (B), the adhesion to the substrate and the stain resistance are further improved. The composition for coating of the present invention is obtained.

Examples of the acrylic resin (B) include those conventionally used for coatings. In particular, (i) a homopolymer or copolymer of an alkyl ester of (meth) acrylic acid having 1 to 10 carbon atoms, and ( ii) A (meth) acrylate copolymer having a curable functional group at the side chain and / or main chain terminal is preferably employed.

Examples of the acrylic resin (i) include methyl (meth) acrylate, ethyl (meth) acrylate,
Butyl (meth) acrylate, cyclohexyl (meth)
Examples include homopolymers such as acrylates and copolymers thereof with an ethylenically unsaturated monomer copolymerizable therewith. As the copolymerizable ethylenically unsaturated monomer,
For example, (meth) acrylates having an aromatic group, α
Having a fluorine atom or a chlorine atom at the position, fluoroalkyl (meth) acrylates having an alkyl group substituted by a fluorine atom, vinyl ethers, vinyl esters, aromatic vinyl monomers, ethylene, propylene, isobutylene, chloride Vinyl, vinylidene chloride, fumaric acid diesters, maleic acid diesters, (meth) acrylonitrile and the like. Commercially available acrylic resins of this type include, for example, those manufactured by Hitachi Chemical Co., Ltd. such as Hitaloid 1005, Hitaloid 1206, Hitaloid 2230-60, Hitaloid 4001, and Hitaloid 1628A; such as Diamond LR-1065 and Diamond LR-90. Manufactured by Mitsubishi Rayon Co., Ltd .; Paraloid B-44, Paraloid A
Rohm & Haas such as -21 and Paraloid B-82; and DuPont such as ELVACITE2000.

Examples of the acrylic resin of the type (ii) include a copolymer of a monomer having a hydroxyl group, an epoxy group, an amino group, or the like as a curable functional group and (meth) acrylate. Specific examples include, for example, hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl vinyl ether,
-Hydroxyethyl vinyl ether, glycidyl (meth) acrylate, 2-aminoethyl (meth) acrylate, a copolymer of 2-aminopropyl (meth) acrylate, etc., and a lower alkyl ester of the (meth) acrylate, or a copolymer thereof with the ethylene Examples thereof include copolymers with unsaturated monomers, but are not limited thereto. Commercial products of the acrylic resin (ii) include Hitaloid 3004, Hitaloid 3018, and Hitaloid 3046.
C and others manufactured by Hitachi Chemical Co., Ltd .; Acrydeik A
810-45, Acrydeik A814, Acrydeik 47-540
Manufactured by Dainippon Ink and Chemicals, Inc .; manufactured by Mitsubishi Rayon Co., Ltd. such as Dianal LR-257 and Dianal LR-1503; Oyster Q166, Oyster Q185
And those manufactured by Mitsui Toatsu Chemical Co., Ltd.

The number average molecular weight of the acrylic resin (B) was 3 measured by GPC.
000 to 200,000, preferably 5000 to 100,000, and when it is large, the solvent solubility tends to be reduced. When it is small, the strength of the coating film is reduced and cracks tend to be easily generated.

In the composition of the present invention, the ratio of the vinylidene fluoride copolymer (A) to the acrylic resin (B) is such that the acrylic resin (B) is 1 to 100 parts (parts by weight, hereinafter the same) of the copolymer (A). 900900 parts, preferably 3 to 300 parts. When blended in this range, the pigment dispersibility of the paint is good, and the resulting coating film is excellent in light transmittance and gloss.

The coating composition of the present invention is used by dissolving the components (A) and (B) in a solvent at a concentration of 5 to 95% by weight, preferably 10 to 70% by weight. As the solvent, for example, ethyl acetate,
Esters such as butyl acetate, isopropyl acetate, isobutyl acetate and cellosolve acetate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; cyclic ethers such as tetrahydrofuran and dioxane; N, N-dimethylformamide, N, N- Amides such as dimethylacetamide; aromatic hydrocarbons such as toluene and xylene; mixed solvents thereof.

When the coating composition of the present invention is used as a curing coating, a curing agent is added. Copolymer (A) as curing agent
In addition, for example, isocyanates, amino resins, acid anhydrides, etc., which are crosslinked by reacting with the cured site of the curable functional group-containing acrylic resin (B), are usually used.

Specific examples of the isocyanates include, for example, 2,
4-tolylene diisocyanate, diphenylmethane-4,
4'-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, lysine methyl ester diisocyanate, methylcyclohexyl diisocyanate, trimethylhexamethylene diisocyanate,
Hexamethylene diisocyanate, n-pentane-1,4
-Diisocyanates, trimers thereof, adducts obtained by blocking them, and polymers of these having two or more isocyanate groups, but are not limited thereto.

Specific examples of the amino resins include, but are not limited to, methylol urea resin, methylol melamine resin, methylol benzoguanamine resin, and resins obtained by etherifying these with alcohols such as methanol, ethanol, and butanol. Not something.

Specific examples of the acid anhydrides include, for example, phthalic anhydride, picomellitic anhydride, and melitic anhydride, but are not limited thereto.

The amount of the curing agent is determined by the amount of the functional group (—OH group) in the vinylidene fluoride copolymer (A) and the acrylic resin (B).
0.1 to 5 equivalents to 1 equivalent of the total amount of the functional groups in the
Preferably it is 0.5 to 1.5 equivalents. The composition of the present invention can be usually cured at 0 to 200 ° C. for several minutes to about 10 days.

The coating composition of the present invention may further contain various additives that are added to a general coating composition.
Examples of the additives include a curing accelerator, a pigment, a pigment dispersant, a leveling agent, an antifoaming agent, an anti-gelling agent, an ultraviolet absorber, and an antioxidant.

Examples of the curing accelerator include an organotin compound, an acid phosphate, a reaction product of an acid phosphate and an amine, a saturated or unsaturated polycarboxylic acid or an acid anhydride thereof, an organic titanate compound, an amine compound, And lead octylate.

Specific examples of the organotin compound include dibutyltin dilaurate, dibutyltin maleate, dioctyltin maleate, dibutyltin diacetate, dibutyltin phthalate, tin octylate, tin naphthenate, dibutyltin methoxide, and the like.

In addition, the acidic phosphate ester, Phosphate ester containing moieties, such as (Wherein b represents 1 or 2 and R ³ represents an organic residue). In particular And so on.

Examples of the organic titanate compound include titanates such as tetrabutyl titanate, tetraisopropyl titanate, and triethanolamine titanate.

Further, specific examples of the amine compound include butylamine, octylamine, dibutylamine, monoethanolamine, diethanolamine, triethanolamine, diethylenetriamine, triethylenetetramine, oleylamine, octylamine, cyclohexylamine, benzylamine, and diethylaminopropylamine. , Xylylenediamine, triethylenediamine,
Guanidine, diphenylguanidine, 2,4,6-tris (dimethylaminomethyl) phenol, morpholine, N
Amine compounds such as -methylmorpholine and 1,8-diazabicyclo (5,4,0) undecene-7 (DBU), and salts thereof such as carboxylic acids, and low amounts obtained from excess polyamines and polybasic acids Examples include polyamide resins and reaction products of excess polyamine and epoxy compounds.

One type of curing accelerator may be used, or two or more types may be used in combination.

The mixing ratio of the curing accelerator is 0.0 with respect to a total of 100 parts of the vinylidene fluoride copolymer (A) and the acrylic resin (B).
About 5 to 10 parts are preferable, and about 0.1 to 5 parts is more preferable.

The composition of the present invention can be prepared by thoroughly mixing the above components.

The composition of the present invention has good gloss and provides a coating film excellent in weather resistance, corrosion resistance, chemical resistance, post-processability, adhesion to a substrate, hardness, etc. Similarly, it can be applied directly to metals, concrete, plastics, etc. as indoor or indoor paints, or overlaid on primers such as wash primers, rust preventive paints, epoxy paints, acrylic resin paints, polyester resin paints.

Hereinafter, the present invention will be described more specifically with reference to Production Examples, Examples, and Comparative Examples.

Production Example 1 (Production / Evaluation of Vinylidene Fluoride Copolymer (A)) In a stainless steel autoclave having an inner volume of 3 and having a stirrer of 1000 ml, ethyl acetate, 4-hydroxybutyl vinyl ether (HBVE) and vinyl pivalate (VPi) were added. Is 1/1
(Molar ratio) of a mixed solution of 4.8 g, and after removing dissolved air by nitrogen replacement and deaeration, 52.8 g of tetrafluoroethylene (TFE) and vinylidene fluoride (Vd
F) 400.8 g of each was charged, and the autoclave was heated. After the internal temperature reached 40 ° C., 2.0 g of diisopropyl peroxydicarbonate (IPP) was introduced to initiate polymerization. At the start, the reaction pressure was 18.0 kg / cm ² . Then, due to the pressure drop, 151.2 kg of a mixed monomer having VdF and TFE of 88/12 (molar ratio) and 74.1 g of a mixed monomer having HBVE and VPi of 1/1 (molar ratio) were introduced. , Total IPP in the meantime
The polymerization was continued by adding 7.0 g.

Fifteen hours after the initial addition of IPP, the reaction was stopped by cooling the polymerization tank with water, and after cooling to room temperature, unreacted monomers were purged and the autoclave was opened. The obtained copolymer solution was poured into normal hexane to precipitate a product, which was washed and dried to obtain a copolymer. The yield of the copolymer was 301 g.

Intrinsic viscosity [η] of the obtained copolymer (in THF, 30 ° C)
Is 0.12dl / g, GPC method (polystyrene standard, developing solvent TH
The number average molecular weight according to F) is 4500 and the weight average molecular weight is 9000
Met. The thermal decomposition onset temperature (measured in the air using a differential thermal / thermogravimeter at a heating rate of 10 ° C / min)
207 ° C. The composition of the copolymer determined by ¹⁹ F-NMR and ¹ H-NMR measurements was VdF / TFE / VPi / HBVE = 74/12/7/7
(Mol%).

The solvent solubility of the vinylidene fluoride copolymer and the compatibility with the acrylic resin were examined by the following method. The results are shown in Table 1.

(Solvent solubility) 30 g of vinylidene fluoride copolymer is added to 70 g of each solvent of butyl acetate, ethyl acetate, methyl ethyl ketone and acetone at room temperature with stirring, and the solubility / insolubility is visually determined. In the evaluation, 可 represents soluble and × represents insoluble.

(Compatibility) 100 parts of vinylidene fluoride copolymer and polymethyl methacrylate (manufactured by DuPont, ELVACITE2000) (hereinafter referred to as PMMA
100 parts) and press-molded under the conditions of 180 ° C. and 10 kg / cm ² to produce a 0.1 mm thick plate, and visually observe the transparency of the obtained plate.

Production Example 2 Under the same conditions as in Production Example 1, a vinylidene fluoride copolymer in which TFE was replaced with chlorotrifluoroethylene (CTFE) was synthesized.

The yield of the obtained copolymer was 303 g, and the intrinsic viscosity [η] was 0.3.
The thermal decomposition initiation temperature was 11 dl / g and 210 ° C. The composition of the copolymer determined from the NMR measurement results was VdF / CTFE / VPi / HBVE = 7
4/11/8/7 (mol%).

Further, in the same manner as in Production Example 1, solvent solubility and compatibility were examined. The results are shown in Table 1.

Production Examples 3 to 14 Vinylidene fluoride copolymer (A) having the composition shown in Table 1
Was produced under the same conditions as in Production Example 1. Table 1 shows the yield and intrinsic viscosity [η] of each copolymer, and the results obtained by examining the solvent solubility and compatibility in the same manner as in Production Example 1.

Comparative Production Example 1 A fluorine-containing copolymer having the composition shown in Table 1 was produced in the same manner as in Production Example 1. The yield, intrinsic viscosity [η], solvent solubility, and compatibility with PMMA of the obtained copolymer were examined in the same manner as in Production Example 1.

 The results are shown in Table 1.

Comparative Production Example 2 12.5 g of ethyl vinyl ether (EVE), 12.5 g of HBVE, 50 g of vinyl-2,2-dimethylhexanoate (VDMHe) and 53.8 methyl isobutyl ketone were placed in a 250 cc SUS autoclave.
g, azobisisovaleronitrile 1.25 g, tert-butyl peroxyoctoate 1.25 g and 1,2,2,6,6-pentamethylpiperidyl 0.75 g were charged, and the mixture was replaced with nitrogen and degassed. And 12.5 g of VdF, respectively, and reacted at 55 ° C. for 15 hours while stirring, and then heated to 85 ° C.
The reaction was continued for an hour to obtain 85 g of a fluorinated copolymer.

Table 1 shows the composition, intrinsic viscosity [η], solvent solubility, and compatibility with PMMA of this fluorinated copolymer.

Comparative Production Example 3 A fluorinated copolymer having the composition shown in Table 1 was prepared in Comparative Production Example 2.
It was manufactured in the same manner as described above. The yield, intrinsic viscosity [η], solvent solubility, and compatibility with PMMA of each obtained copolymer were the first.
It is shown in the table.

Comparative Production Example 4 To a stainless steel autoclave having an inner volume of 260 cc, 61.1 g of xylene and 17.5 g of ethanol were added, 21.2 g of cyclohexyl vinyl ether (CHVE), 20.2 g of ethyl vinyl ether (EVE), 13.0 g of HBVE, and 2.0 g of potassium carbonate.
And 0.48 g of azobisisobutyronitrile (AIBN) were charged, and dissolved air was removed by solidification and degassing with liquid nitrogen. Thereafter, 65.3 g of CTFE was introduced into the autoclave, and the temperature was gradually raised. When the temperature in the autoclave reached 65 ° C., the pressure showed 6.3 kg / cm ² . Thereafter, the reaction was continued under stirring for 8 hours. When the pressure dropped to 0.65 kg / cm ² , the autoclave was cooled with water to stop the reaction. After reaching room temperature, unreacted monomers were purged and the autoclave was opened. The obtained polymer solution was filtered with a glass filter, and potassium carbonate was separated by filtration. Then, 0.48 g of hydroquinone monomethyl ether was added. Next, the ethanol was removed by a rotary evaporator and concentrated.
The polymer yield obtained by measuring the polymer concentration is 110 g
Met. Table 1 shows the composition, intrinsic viscosity [η], solvent solubility, and compatibility with PMMA of this fluorinated copolymer.

Comparative Production Example 5 A fluorinated copolymer having the composition shown in Table 1 was prepared in Comparative Production Example 4.
It was manufactured in the same manner as described above. Table 1 shows the yield, intrinsic viscosity [η], solvent solubility, and compatibility with PMMA of the obtained copolymer.

In addition, the symbol of the monomer in Table 1 shows the following, respectively.

VdF: vinylidene fluoride TFE: tetrafluoroethylene CTFE: chlorotrifluoroethylene HFP: hexafluoropropylene HBVE: 4-hydroxybutyl vinyl ether VPi: vinyl pivalate Veova-10: vinyl versatate manufactured by Shell Chemical Company VAc: vinyl acetate VPr : Vinyl propionate VBu: Vinyl butyrate VDMHe: Vinyl 2,2-dimethylhexanoate EVE: Ethyl vinyl ether CHVE: Cyclohexyl vinyl ether Example 1 A fluorine-containing copolymer and an acrylic resin shown in Table 2 were dissolved in a mixed solvent (ethyl acetate / butyl acetate / xylene = 40/30/30 weight ratio) so that the solid content was 25% by weight. I let it. The second step was performed so that the equivalent ratio of OH groups to NCO groups would be 1.0.
An isocyanate-based curing agent shown in the table was blended to prepare a coating composition.

The obtained coating composition was applied on an aluminum plate (AM-712 treatment, manufactured by Nippon Test Panel Co., Ltd.) by spraying and left at room temperature for 7 days. The following test was performed on this coated aluminum plate.

 The results are shown in Table 2.

(Pencil hardness) Perform according to JIS K 5400.

(Adhesiveness) Cut 100 squares of 1 mm square on the coating film with a knife and check the number of remaining squares after repeating adhesion and peeling ten times with adhesive tape.

(Solvent resistance) The surface is rubbed with a Kimwipe impregnated with xylene, and the number of times until the coating film becomes white is examined. Evaluation is based on the following criteria.

 ◎: No whitening occurs even over 100 days.

 :: whitening occurs 60 to 100 times.

 ×: Whitening occurs in less than 60 times.

(Magic stain resistance) Red magic ink (Product name: Sakura Pen Touch Red)
Is applied on the coating film in a 2 cm × 2 cm square, left for 24 hours, wiped off with ethanol, and visually observed for the remaining state of the ink. Evaluation is based on the following criteria.

 A: Completely removed.

 ：: Slightly remaining.

 Δ: Slightly left.

 ×: Remains considerably.

(Composite contamination resistance) Peat moss / cement / kaolin / silica gel / carbon black / ferric oxide / liquid paraffin in weight ratio
After applying a composite contaminant with the composition of 38/17/17/17 / 1.75 / 0.5 / 8.75 to the coating film, it was tested for 100 hours with an iSuper UV tester (weather tester manufactured by Iwasaki Electric Co., Ltd.) and washed with water I do. Using this as one cycle, the gloss retention and color difference after 5 cycles are examined with a color computer SM-4 (manufactured by Suga Test Instruments Co., Ltd.). In addition, the appearance at that time is visually observed and evaluated according to the following criteria.

 A: Almost no dirt remains.

 ：: Slightly remaining.

 Δ: Partially remained.

 X: Remarkably remains on the entire surface.

(Glossiness) Measure the 60-degree specular glossiness of JIS K 5400.

(Weather resistance) Sunshine weatherometer (Suga Test Machine Co., Ltd.)
Rain / irradiation cycle: 12 hours / 60 minutes, humidity: 50%, black panel temperature: 63 ° C, 4000 hours
Perform a time exposure test. It is evaluated by gloss retention (%) after exposure.

The acrylic resin and the curing agent in Table 2 are as follows.

[Acrylic resin] Hitachiloid 3004: Polyol acrylic resin solution manufactured by Hitachi Chemical Co., Ltd.

Hitaroid 1005: Lacquer type acrylic resin solution manufactured by Hitachi Chemical Co., Ltd.

Hitachiloid 1206: Lacquer type acrylic resin solution manufactured by Hitachi Chemical Co., Ltd.

Paraloid B-44: a lacquer type acrylic resin solution manufactured by Loin & Ham.

Diamond LR1065: A lacquer type acrylic resin solution manufactured by Mitsubishi Rayon Co., Ltd.

Diamond LR90: A lacquer type acrylic resin solution manufactured by Mitsubishi Rayon Co., Ltd.

Olester Q166: Polyol acrylic resin solution manufactured by Mitsui Toatsu Chemicals, Inc.

Olester Q185: Polyol acrylic resin solution manufactured by Mitsui Toatsu Chemicals, Inc.

Acrydic A-180-45: Polyol acrylic resin solution manufactured by Dainippon Ink and Chemicals, Inc.

Acrydic 47-540 A polyol acrylic resin solution manufactured by Dainippon Ink and Chemicals, Inc.

[Curing agent] Coronate EH: A hexamethylene diisocyanate trimer solution manufactured by Nippon Polyurethane Co., Ltd.

Takenate D140N: Isophorone diisocyanate adduct solution manufactured by Takeda Pharmaceutical Company Limited.

Takenate D170N: a hexamethylene diisocyanate trimer solution manufactured by Takeda Pharmaceutical Co., Ltd.

Takenate XD170HN: a modified solution of hexamethylene diisocyanate trimer manufactured by Takeda Pharmaceutical Company Limited.

Takenate XD170HN-M1: A modified solution of hexamethylene diisocyanate trimer manufactured by Takeda Pharmaceutical Company Limited.

Example 2 A fluorinated copolymer and an acrylic resin shown in Table 3 were used at 80/2
The mixture was mixed at a weight ratio of 0 (in terms of solid content), and the obtained mixture was mixed with a melamine resin as a curing agent so that the weight ratio of mixture / melamine resin (in terms of solid content) was 70/30. A phosphoric acid catalyst (XL-391 manufactured by Hoechst) and an ultraviolet absorber (Nihon Ciba Geigy Co., Ltd.) were used for 100 parts by weight of this mixture.
5 parts by weight, 2 parts by weight and 1 part by weight of Tinuvin 900 manufactured by Nippon Ciba Geigy Co., Ltd.) and a light stabilizer (Tinuvin 144 manufactured by Nippon Ciba Geigy Co., Ltd.) were added and mixed to prepare a coating composition. As the solvent, the same mixed solvent as in Example 1 was used.

This coating composition was applied to a substrate with a spray gun, and the coating film was heated and cured at 140 ° C. for 30 minutes to obtain a test plate (film thickness 4).
0-50 μm). The board is made of a steel plate for automobile (manufactured by Nippon Test Panel Co., Ltd.) with a white intermediate coating (Nippon Paint Co., Ltd.)
Olga P-2) / undercoat for overcoating (Acrydic A322 manufactured by Dainippon Ink and Chemicals, Super Beckamine L-117-60 manufactured by the company, Color Black FW-200 manufactured by Degussa, and Toyo) 80 parts by weight, 120 parts by weight of Alpaste 1109MA manufactured by Aluminum Co., Ltd.
Parts by weight and 1 part by weight of the paint) and
For 30 minutes.

For the obtained test plate, pencil hardness,
The adhesiveness, solvent resistance, composite stain resistance, glossiness and weather resistance were examined, and the moisture resistance was examined according to the following method. The composite contamination resistance was determined only by observing the appearance (evaluation criteria are described in Example 1), and the weather resistance was also evaluated by visual observation.

 The results are shown in Table 3.

(Moisture resistance) The test plate is left in the atmosphere of 50 ° C and RH98% for 240 hours.
Those with severe deterioration of the coating film and those with blisters and cracks were judged to be rejected.

The melamine resin abbreviations in Table 3 indicate the following.

Cymel 303: A fully alkylated melamine resin manufactured by Mitsui Cyanamid Co., Ltd.

Cymel 370: Methylolated melamine resin manufactured by Mitsui Cyanamid Co., Ltd.

[Effect of the Invention] The coating composition of the present invention is soluble in a general-purpose solvent for coating and can be cured by a reaction. further,
The resulting coating film has good gloss, weather resistance, stain resistance, adhesion to a substrate, hardness, and the like.

Continued on the front page (72) Inventor Akira Senda 1-1, Nishiichitsuya, Settsu-shi, Osaka Daikin Industries, Ltd. Yodogawa Works (72) Inventor Atsushi Sakakura 1-1-1, Nishiichitsuya, Settsu-shi, Osaka Daikin Industries (56) References JP-A-62-292814 (JP, A) JP-A-62-292813 (JP, A) JP-A-2-41350 (JP, A) (58) Fields studied (Int .Cl. ⁶ , DB name) C09D 127 / 12,133 / 04 CA (STN) CAOLD (STN) REGISTRY (STN)

Claims (4)

(57) [Claims] (A) A structural unit represented by the general formula (I): —CH ₂ —CF ₂ — (I) 50 to 90 mol%, a general formula (II): (Wherein X represents a fluorine atom, a chlorine atom, a hydrogen atom or a trifluoromethyl group)
30 mol%, general formula (III): (Wherein R ¹ represents an alkylene group having 2 to 10 carbon atoms) 1 to 30% of a structural unit represented by the following general formula (IV): (Wherein, R ² represents an aromatic group or an alkyl group having 1 to 10 carbon atoms), and 1 to 30 mol% of a structural unit represented by the following formula: A coating composition comprising: a fluorinated copolymer comprising: and (B) an acrylic resin. 2. The composition according to claim 1, further comprising a curing agent. 3. The composition according to claim 1, wherein the acrylic resin is a homo- or copolymer of an alkyl ester of (meth) acrylic acid having 1 to 10 carbon atoms. 4. The composition according to claim 1, wherein the acrylic resin is a (meth) acrylate copolymer having a curable functional group at a side chain and / or a main chain terminal.