JPH0454708B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention uses a mixture of a fluorine-containing copolymer containing hydroxyl groups (hereinafter simply referred to as fluororesin) and an acrylic copolymer to a curing agent containing a functional group that reacts with hydroxyl groups (hereinafter simply referred to as curing agent). Solid color paints with excellent water resistance, solvent resistance, and weather resistance are produced by heating and curing them with
Metallic paints, clear paints, etc. can be obtained, especially when used as metallic paints.
This invention relates to a thermosetting resin composition for paint that has the advantage of exhibiting a great effect on aluminum retention. It has been known that coatings with excellent weather resistance can be obtained by crosslinking fluororesins, but commercially available fluororesins do not mix with other resins or curing agents. It has poor compatibility and is expensive, so it could not be offered to the market as a coating composition at a low cost. In addition, top-coat metallic paints for automobiles can be applied using a two-coat, one-bake method in which a metallic base enamel paint is applied, then a clear paint is applied and then baked, or a clear paint is omitted and the metallic base enamel paint is applied and then left as is. A one-coat, one-bake method is used, and conventionally, cellulose acetate plasticate resin, nitrocellulose resin, etc. have been used for the purpose of aluminum retention, but if the amount of these resins used is small, the aluminum retention may be insufficient. If it is sufficient, but if it is too large, there are disadvantages such as poor weather resistance and poor interlayer adhesion between the metallic base enamel coating and the clear coating in a two-coat, one-bake metallic paint. The present inventors conducted various studies to overcome the above drawbacks, and found that the number of carbon atoms in the alkyl group is 10 to 18.
We have found that acrylic copolymers obtained from alkyl esters of acrylic acid or methacrylic acid exhibit compatibility with fluororesins. By mixing the acrylic copolymer with the fluororesin, the compatibility with the curing agent is improved, and the heat-cured coating film has the excellent water resistance that the fluororesin possesses. , solvent resistance, and weather resistance, it is possible to obtain solid color paints, metallic paints, and clear paints with excellent water resistance, solvent resistance, and weather resistance at low cost. The present invention was completed by discovering that this method is highly effective for aluminum fixings. That is, the present invention provides (A) (a) a fluorine-containing copolymer containing hydroxyl groups 2 to 70;
(b) 30-98% by weight of a copolymer containing an alkyl ester of acrylic acid or methacrylic acid (the alkyl group has 10 to 18 carbon atoms) and other acrylic acid monomers and containing a hydroxyl group. and (B) a curing agent containing a functional group that reacts with a hydroxyl group. Examples of the fluororesin used in the present invention include those derived from copolymerization of fluoroolefin and cyclohexyl vinyl ether, alkyl vinyl ether, hydroxyalkyl vinyl ether, etc., as disclosed in JP-A No. 57-34107. Commercial products such as Lumiflon LF-100, LF-200, manufactured by Asahi Glass Co., Ltd.
Examples include LF-300 and LF-400 (both trademarks). Alkyl ester of acrylic acid or methacrylic acid used in the present invention (the number of carbon atoms in the alkyl group is
A copolymer consisting of 10-18) (hereinafter simply referred to as acrylic ester) and other acrylic monomers contains a hydroxyl group, and the hydroxyl group is the same as other acrylic monomers. It can be introduced by copolymerization, but in some cases, it may be introduced by using an alkyl ester containing a hydroxyl group. Examples of the alkyl ester include decyl acrylate, decyl methacrylate, lauryl acrylate, lauryl methacrylate, tridecyl acrylate, tridecyl methacrylate, myristyl acrylate, myristyl methacrylate, cetyl acrylate, cetyl methacrylate, stearyl acrylate, and stearyl methacrylate. In addition, if the alkyl group of the acrylic ester has 9 or less carbon atoms, it is not compatible with the fluororesin, so the purpose of the present invention cannot be achieved, and if the alkyl group has 19 or more carbon atoms, synthesis is difficult. , and the various properties of the resulting coating film are insufficient. Other acrylic monomers used in the present invention include those having a hydroxyl group, such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, and 2-hydroxypropyl methacrylate. For example, acrylic acid, methacrylic acid, etc.
For example, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, butyl acrylate, butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, cyclohexyl acrylate, Examples include cyclohexyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, and styrene. In order to obtain a copolymer consisting of the above acrylic ester and other acrylic monomers (hereinafter referred to as acrylic copolymer), at least 20% by weight of the acrylic ester, based on the total amount of the acrylic ester and other acrylic monomers, It is preferably used in an amount of at least 30% by weight (if it is less than 20% by weight, it does not show compatibility with the fluororesin and the purpose of the present invention cannot be achieved), and then an organic solvent, a polymerization initiator, etc. are added. using a conventional solution polymerization method, for example, reacting at 80 to 150°C for 3 to 6 hours. Examples of organic solvents used here include aliphatic hydrocarbons such as mineral spirits; aromatic hydrocarbons such as toluene and xylene;
Aromatic naphthas such as 100 (manufactured by Etsuso), (trademark) Sorbetsuso 150 (manufactured by Etsuso) (trademark); ethyl acetate;
Examples include esters such as butyl acetate; alcohols such as butanol; ketones such as methyl ethyl ketone; and ether alcohols such as butyl cellosolve; however, aromatic hydrocarbons, esters, and aromatic naphtha are preferred. In addition, the polymerization initiator used here is a compound that thermally decomposes to generate radicals,
For example, benzoyl peroxide, lauroyl peroxide, di-tert-butyl peroxide, methyl ethyl ketone peroxide, tert-
Examples include butyl peroxyisobutyrate. These polymerization initiators are used in proportion to the total amount of acrylic ester and other acrylic monomers.
Add at a concentration of 0.1 to 5.0% by weight. The hydroxyl equivalent of the obtained acrylic copolymer is preferably 500 to 2000, and preferably 650 to 1500.
It is particularly preferable that If the hydroxyl equivalent weight of the acrylic copolymer is less than 500, the mechanical strength of the resulting coating film will decrease, and if it exceeds 2,000, curing will be insufficient, resulting in poor water resistance and resistance of the resulting coating film. Solvent properties etc. decrease. Furthermore, the acid value of the obtained acrylic copolymer is 0.
~25 is preferable (if it exceeds 25, it is practically unfavorable in terms of the pot life and storage stability of the paint), and the reactivity of the curing agent, the pot life of the paint,
It may be determined as appropriate based on storage stability and the like. A copolymer mixture consisting of a fluororesin and an acrylic copolymer is obtained by mixing 2 to 70% by weight of the fluororesin and 30 to 98% by weight of the acrylic copolymer. If the amount of fluororesin is less than 2% by weight, it will not be able to provide the excellent performance that fluororesin possesses, and when used as a metallic base enamel paint, it will not have the effect of retaining aluminum, and
If it exceeds % by weight, the compatibility with the curing agent decreases, and the various properties of the resulting coating film deteriorate. Examples of the curing agent used in the present invention include alkyl etherified amino resins, isocyanate compounds, polycarboxylic acid compounds, chlorides of polycarboxylic acid compounds, and epoxy group-containing compounds. From the viewpoint of coating film performance, etc., alkyl etherified amino resin,
Isocyanate compounds are preferred. Examples of the alkyl etherified amino resin include melamine resins, urea resins, and benzoguanamine resins that have been converted to alkyl ethers such as methyl ether, butyl ether, and isobutyl ether. In addition, in order to promote the curing reaction, an acid catalyst can be added as necessary. The mixing ratio of the copolymer mixture and the alkyl etherified amino resin is 60 to 95% by weight of the copolymer mixture and 5 to 40% by weight of the alkyl etherified amino resin. If the content of the alkyl etherified amino resin is less than 5% by weight, curing will be insufficient and the resulting coating film will have poor water resistance, solvent resistance, etc. If it exceeds 40% by weight, the resulting coating film will intensity,
Acid resistance etc. decrease. Examples of the isocyanate compounds include polyisocyanate compounds and blocked polyisocyanate compounds. Examples of the polyisocyanate compound include any conventionally known ones, such as ethylene diisocyanate, propylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, phenylene diisocyanate, tolylene diisocyanate, naphthylene diisocyanate, isophorone diisocyanate, 4,4 '-methylene bis(cyclohexyl isocyanate), lysine diisocyanate methyl ester, triphenylmethane triisocyanate, etc., are pyuret type adducts, isocyanuric ring type adducts, polyhydric alcohol adducts, etc. Among these, good In order to obtain good weather resistance, non-yellowing types such as hexamethylene diisocyanate, isophorone diisocyanate,
Preferred are Piuret type adducts such as 4,4'-methylenebis(cyclohexyl isocyanate) and lysine diisocyanate methyl ester, isocyanuric ring type adducts, and polyhydric alcohol adducts. Examples of the blocked polyisocyanate compound include those obtained by blocking the above-mentioned polyisocyanate compounds with a blocking agent. Examples of the blocking agent include phenol-based, alcohol-based, mercaptan-based, oxime-based, lactam-based, imine-based, and active methylene-based compounds. In addition, in order to accelerate the curing reaction, an organometallic compound such as dibutyltin dilaurate, tetrabutyl titanate, or zinc naphthenate can be used as a catalyst, if necessary. The mixing ratio of the copolymer mixture and the isocyanate compound is defined by the molar ratio of isocyanate groups/hydroxyl groups. The molar ratio is preferably
0.5 to 1.5, particularly preferably 0.7 to 1.3, and 0.5
If it is less than 1.5, the mechanical properties and chemical resistance of the resulting coating film will deteriorate, and if it exceeds 1.5, a large amount of isocyanate will remain inside the coating film after heat curing, and the weather resistance of the coating film will deteriorate. descend. When making a paint from the thermosetting resin composition for paint of the present invention, pigments, dyes, aluminum flakes, additives (such as dispersion stabilizers, Anti-sagging agents, leveling agents, anti-gelling agents, ultraviolet absorbers, light stabilizers, etc.) are added, and the equipment used in normal paint production, such as ball mills, paint sheakers, sand mills, triple rolls, kneaders, etc. Can be used. The resulting paint can be applied to metals, other inorganic materials, and organic materials such as plastics by conventional coating methods such as air spraying, airless spraying, electrostatic coating, and dipping. The resulting coating film can be stored at room temperature or at 70°C, depending on the type of curing agent used and the heat resistance of the coated material.
When cured by heating at ~250°C for 1 to 60 minutes, a smooth, glossy, cured film with excellent water resistance, solvent resistance, weather resistance, etc. can be obtained, and when used as a metallic base enamel paint. It is possible to obtain a cured coating film with good aluminum retention comparable to coatings of metallic paints using cellulose acetate butyrate resin without impairing weather resistance. Hereinafter, the present invention will be explained in further detail with reference to Production Examples, Examples, and Comparative Examples. In examples, parts are parts by weight, %
is weight %. Production example 1 [Manufacture of acrylic copolymer (1)] Butanol 30 parts Solbetsuso 100 (manufactured by Etsuso, trademark, aromatic naphtha) 250〃 Solbetsuso 150 (manufactured by Etsuso, trademark, aromatic naphtha) 50〃 Above A solvent mixture having the following composition was gently refluxed at 140 to 144°C, and a mixture of an acrylic monomer and a polymerization initiator having the following composition was added dropwise to the mixture over 2 hours with stirring. Methyl methacrylate 175 parts 2-ethylhexyl acrylate 75〃 Acrylic ester SL (Mitsubishi Rayon Co., Ltd., trademark, mixture of lauryl methacrylate and tridecyl methacrylate) 150〃 2-hydroxyethyl methacrylate 85 parts 70% xylene solution of acrylic acid 14 〃 Benzoyl peroxide 5〃 Then, after continuing to reflux for another 1 hour, 2 parts of benzoyl peroxide and 60 parts of Solbetsuso 100 (manufactured by Etsuso Co., Ltd., mentioned above) were added, and the mixture was stirred at 145°C for 2 hours to make the resin solution non-volatile. The reaction was terminated when the time reached 55%. Then, after cooling to room temperature, 50 parts of Solbetsuso 100 (manufactured by Etsuso, mentioned above),
Add 54 parts of Solbetsuso 150 (manufactured by Etsuso, mentioned above),
An acrylic copolymer solution having a nonvolatile content of 50%, a resin acid value of 16.0, and a hydroxyl equivalent of 750 was obtained. Production example 2 [Production of acrylic copolymer (2)] Butanol 30 parts Solbetsuso 100 (manufactured by Etsuso, above - Production example 1)
250 parts Solbetsuso 150 (manufactured by Etsuso, mentioned above - Manufacturing Example 1)
50〃 A solvent mixture having the above composition was gently refluxed at 140 to 144°C, and a mixture of an acrylic monomer and a polymerization initiator having the composition shown below was added dropwise thereto over 2 hours with stirring. Methyl methacrylate 240 parts Cyclohexyl methacrylate 35〃 Stearyl methacrylate 125〃 2-Hydroxyethyl methacrylate 85〃 70% xylene solution of acrylic acid 16〃 Benzoyl peroxide 5〃 Next, after continuing to reflux for another hour, 2 parts of benzoyl peroxide, 60 parts of Solbetsuso 100 (manufactured by Etsuso, mentioned above - Production Example 1) was added and stirred at 145°C for 2 hours, and the reaction was terminated when the nonvolatile content of the resin solution reached 55%. Then, after cooling to room temperature, 48 parts of Solbetsuso 100 (manufactured by Etsuso Co., Ltd., mentioned above - Production Example 1) and Solbetsuso 150 (manufactured by Etsuso Co., Ltd.,
54 parts of Preparation Example 1) were added to obtain an acrylic copolymer solution having a nonvolatile content of 50%, a resin acid value of 18.2, and a hydroxyl equivalent of 750. Production Example 3 [Production of acrylic copolymer (3)] 270 parts of xylene, 130 parts of butyl acetate A solution mixture consisting of the above composition was gently refluxed at 130 to 140°C, and an acrylic monomer having the following composition and polymerization initiation were added. The mixture of agents was added dropwise with stirring over a period of 2 hours. Methyl methacrylate 240 parts Butyl methacrylate 27〃 Acrylic ester SL (manufactured by Mitsubishi Rayon Co., Ltd., above - Production example - 1) 150〃 2-Hydroxyethyl methacrylate 78〃 70% xylene solution of acrylic acid 7〃 Benzoyl peroxide 2 Then, after continuing to reflux for another 1 hour, 1 part of benzoyl peroxide and 33 parts of butyl acetate were added, and the mixture was stirred at 137°C for 2 hours, and the reaction was terminated when the nonvolatile content of the resin solution reached 53%. Then, after cooling to room temperature, 62 parts of xylene was added to give a mixture with a non-volatile content of 50%, a resin acid value of 8.0, and a hydroxyl equivalent of 830.
An acrylic copolymer solution was obtained. Production example 4 [Production of acrylic copolymer (4)] Butanol 30 parts Solbetsuso 100 (manufactured by Etsuso, above - Production example 1)
250〃 Solbetsuso 150 (manufactured by Etsuso, mentioned above - Production Example 1)
50〃 A solvent mixture having the above composition was gently refluxed at 140 to 144°C, and a mixture of an acrylic monomer and a polymerization initiator having the composition shown below was added dropwise thereto over 2 hours with stirring. Methyl methacrylate 150 parts Butyl methacrylate 53〃 Butyl acrylate 22〃 Lauryl methacrylate 175 parts 2-hydroxyethyl methacrylate 85〃 70% xylene solution of acrylic acid 14〃 Benzoyl peroxide 5〃 Then, after continuing to reflux for another hour, benzoyl peroxide 2 parts of oxide and 60 parts of Solbetsuso 100 (manufactured by Etsuso, mentioned above - Production Example 1) were added and stirred at 145°C for 2 hours, and the reaction was terminated when the nonvolatile content of the resin solution reached 55%. After cooling to room temperature, 50 parts of Solbetsuso 100 (manufactured by Etsuso, above-mentioned - Production Example 1) and 50 parts of Solbetsuso 150 (manufactured by Etsuso,
54 parts of the above-mentioned Production Example 1) were added to obtain an acrylic copolymer solution having a nonvolatile content of 50%, a resin acid value of 16.0, and a hydroxyl equivalent of 750. Production Example 5 [Production of acrylic copolymer (5)] Xylene 258 parts Butyl acetate 20 A solvent mixture having the above composition was gently refluxed at 135 to 140°C, and an acrylic monomer having the following composition and polymerization initiation were added. The mixture of agents was added dropwise with stirring over a period of 2 hours. Methyl methacrylate 246 parts Butyl acrylate 157〃 2-Hydroxyethyl methacrylate 61〃 70% xylene solution of acrylic acid 8〃 Benzoyl peroxide 4〃 Next, the mixture was further stirred at 135 to 140°C for 2 hours to reduce the non-volatile content of the resin solution to 61%. The reaction was terminated when the temperature reached . Then, after cooling to room temperature, 139 parts of xylene, 47 parts of cellosolve acetate,
Added 60 parts of butyl acetate, nonvolatile content 48%, resin acid value
9.7, an acrylic copolymer solution with a hydroxyl equivalent of 1000 was obtained. Production Example 6 [Production of 2-coat 1-bake metallic base enamel paint (1)] Acrylic copolymer solution obtained in Production Example 1 80 parts Fluororesin (manufactured by Asahi Glass Co., Ltd., trademark, Lumiflon)
LF100, chlorotrifluoroethylene 50.1 mol% and cyclohexyl vinyl ether 14.8 mol%
Copolymer of isobutyl vinyl ether 25.4 mol% and hydroxybutyl vinyl ether 9.7 mol%, hydroxyl value 26, number average molecular weight 7600, weight average molecular weight 17650, glass transition temperature 41°C, non-volatile content 50%) 20 Alkyl etherified amino Resin (Mitsui Toatsu Chemical Co., Ltd.
(manufactured by Toyo Aluminum Co., Ltd., trademark: Yuban 20SE-60, butyl etherified melamine resin solution, non-volatile content: 60%) Add 11 parts of 65%) dispersed in 11 parts of butyl acetate, stir,
By mixing, a metallic base enamel paint was obtained. Production Example 7 [Production of 2-coat, 1-bake metallic base enamel paint (2)] In Production Example 6, the acrylic copolymer solution obtained in Production Example 2 was replaced with the acrylic copolymer solution obtained in Production Example 1. Production example 6 except that a solution was used
In the same manner as above, a metallic base enamel paint was obtained. Production Example 8 [Production of 2-coat, 1-bake metallic base enamel paint (3)] Acrylic copolymer solution obtained in Production Example 3 80 parts Fluororesin (previously - Production Example 6) 20 parts Polyisocyanate compound [Sumitomo Made by Bayer Urethane Co., Ltd., trademark, Sumidiur N-75, hexamethylene diisocyanate derivative (Biuret type), NCO 16.5%, non-volatile content 75%] 14 parts Aluminum paste (previously described) Production example 6) Add 10 parts of butyl acetate dispersed in 10 parts of butyl acetate, stir and mix.
A liquid type metallic base enamel paint was obtained. Production Example 9 [Production of clear paint (1)] Acrylic copolymer solution obtained in Production Example 4 80 parts Alkyl etherified amino resin (Hoechst Synthesis Co., Ltd.)
Co., Ltd., trademark, Maprenal MF590, butyl etherified melamine resin solution, non-volatile content 55%)
31 parts 10% xylene solution of ultraviolet absorber (manufactured by Ciba Geigy, trademark, Tinuvin 900) 3 parts light stabilizer (manufactured by Ciba Geigy, trademark, Sanol
A clear paint was obtained by stirring and mixing 1 part of a 10% xylene solution of 292). Production Example 10 [Production of clear paint (2)] Acrylic copolymer solution obtained in Production Example 5 80 parts Alkyl etherified amino resin (previously mentioned - Production Example 9) 31 parts UV absorber (previously mentioned - Production Example A clear paint was obtained by stirring and mixing 3 parts of a 10% xylene solution of 9) and 1 part of a 10% xylene solution of the light stabilizer (preparation example 9). Production Example 11 [Production of clear paint (3)] Acrylic copolymer solution obtained in Production Example 5 80 parts Polyisocyanate compound (previously - Production Example 8)
12 parts of a 10% xylene solution of the ultraviolet absorber (preparation example 9), 3 parts of the light stabilizer (preparation example 9) and 1 part of a 10% xylene solution were mixed by stirring to form a two-part type. I got clear paint. Production Example 12 [Production of 1-coat, 1-bake metallic paint (1)] Acrylic copolymer solution obtained in Production Example 4 80 parts Fluororesin (previously - Production Example 6) 15 parts Alkyl etherified amino resin (previously) 37 parts of a 10% xylene solution of the light stabilizer (preparation example 9) Add 4 parts of aluminum paste (preparation example 6) to a mixture of the above composition and 4 parts of butyl acetate Add the dispersed ingredients to the mixture, stir, and mix.
A one-coat, one-bake metallic paint was obtained. Production Example 13 [Production of 1-coat, 1-bake metallic paint (2)] Acrylic copolymer solution obtained in Production Example 3 160 parts Fluororesin (previously produced - Production Example 6) 30 parts Polyisocyanate compound (previously produced) Example 8)
28 parts 10% xylene solution of light stabilizer (preparation example 9) 6 parts A mixture of the above composition with 7 parts of aluminum paste (preparation example 6) dispersed in 7 parts of butyl acetate. Add, stir, mix,
A two-component one-coat, one-bake metallic paint was obtained. Production Example 14 [Production of solid color paint (1)] Acrylic copolymer solution obtained in Production Example 4 80 parts Rutile titanium dioxide (manufactured by Teikoku Kako Co., Ltd., trademark,
JR-602) 6 parts of a 10% xylene solution of 48 parts alkyl etherified amino resin (previously mentioned - Production Example 9) and 37 parts light stabilizer (previously mentioned - Production Example 9) were mixed with stirring to form a solid color paint. Obtained. Production Example 15 [Production of 2-coat, 1-bake metallic base enamel paint (4)] Acrylic copolymer solution obtained in Production Example 1
100 parts cellulose acetate butyrate resin (manufactured by Eastman Kodatsu Company, trademark, EAB381-2)
20% butyl acetate solution 18 parts Alkyl etherified amino resin (preparation example 6) 36 parts Using the mixture consisting of the above composition, a metallic base enamel paint was obtained in the same manner as in production example 6. . Production Example 16 [Production of 2-coat, 1-bake metallic base enamel paint (5)] Acrylic copolymer solution obtained in Production Example 3
100 parts cellulose acetate butyrate resin (see above)
20% butyl acetate solution of Production Example 15) 15 parts Polyisocyanate compound (Preparation Example 8)
15 parts Using the mixture having the above composition, a metallic base enamel paint was obtained in the same manner as in Production Example 8. Production Example 17 [Production of 1-coat, 1-bake metallic paint (3)] Acrylic copolymer solution obtained in Production Example 4 95 parts Cellulose acetate butyrate resin (manufactured by Eastman Kodak, trademark, EAB531-1)
20% butyl acetate solution 17 parts Alkyl etherified amino resin (preparation example 9) 37 parts 10% xylene solution of light stabilizer (preparation example 9) 4 parts Using a mixture consisting of the above composition, Thereafter, a 1-coat, 1-bake metallic paint was obtained in the same manner as in Production Example 12. Production Example 18 [Production of 1-coat, 1-bake metallic paint (4)] Acrylic copolymer solution obtained in Production Example 3
190 parts Cellulose acetate butyrate resin (as above)
20% butyl acetate solution of Production Example 17) 29 parts Polyisocyanate compound (Preparation Example 8)
29〃 10% xylene solution of light stabilizer (previously mentioned - Production Example 9) 6〃 Using the mixture consisting of the above composition, prepare a two-component one-coat one-bake metallic paint in the same manner as in Production Example 13. I got it. Example 1 The metallic base enamel paint obtained in Production Example 6 was treated with a mixed solvent of 50 parts of xylene and 50 parts of butyl acetate (hereinafter simply referred to as mixed solvent) to reduce the paint viscosity (Food Cup #4, 20°C, 15 seconds). ) was air-sprayed onto a steel plate that had been treated with zinc phosphate and then coated with a cationic electrodeposition paint and then an aminoalkyd intermediate paint (dry film thickness: 18 μm). Next, after setting at 20℃ for 3 minutes, the clear paint obtained in Production Example 10 was mixed with a mixed solvent for 20℃.
It was diluted to a second and coated with air spray (dry film thickness 30μ). Then, after setting at 20°C for 20 minutes, it was baked at 140°C for 30 minutes to obtain a cured coating film. As shown in Table 1, the obtained cured coating film was excellent in coating appearance, weather resistance, moisture resistance, and cycle test. Example 2 In Example 1, the metallic base enamel paint obtained in Production Example 6 was replaced with the metallic base enamel paint obtained in Production Example 7.
A cured coating film was obtained in the same manner as in Example 1. As shown in Table 1, the obtained cured coating film was excellent in coating appearance, weather resistance, moisture resistance, and cycle test. Example 3 In the same manner as in Example 1, the metallic base enamel paint obtained in Production Example 6 was air-sprayed onto a steel plate similar to that used in Example 1 (dry film thickness: 18 μm). Then, after setting at 20℃ for 15 minutes,
Bake at 140℃ for 15 minutes. Next, the clear paint obtained in Production Example 9 was diluted with a mixed solvent for 20 seconds and applied with air spray (dry film thickness
30μ). Then, after setting at 20°C for 20 minutes, it was baked at 140°C for 30 minutes to obtain a cured coating film. As shown in Table 1, the obtained cured coating film was excellent in coating appearance, weather resistance, moisture resistance, and cycle test. Example 4 In Example 1, the metallic base enamel paint obtained in Production Example 6 was replaced with the metallic base enamel paint obtained in Production Example 8, and the clear paint obtained in Production Example 10 was changed to Coating was carried out in the same manner as in Example 1, except that the clear paint obtained in Example 11 was used. Next, after setting at 20℃ for 20 minutes,
A cured coating was obtained by baking at ℃ for 30 minutes. As shown in Table 1, the obtained cured coating film was excellent in coating appearance, weather resistance, moisture resistance, and cycle test. Example 5 The one-coat, one-bake metallic paint obtained in Production Example 12 was diluted with a mixed solvent to the paint viscosity (Food Cup #4, 20°C, 15 seconds) and applied to a steel plate similar to that used in Example 1. Painted with air spray (dry film thickness 30μ). Then, after setting at 20℃ for 20 minutes,
A cured coating film was obtained by baking at 140°C for 30 minutes. As shown in Table 1, the obtained cured coating film was excellent in coating appearance, weather resistance, moisture resistance, and cycle test. Example 6 In Example 5, the procedure was the same as in Example 5, except that the 1-coat, 1-bake metallic paint obtained in Production Example 12 was replaced with the 1-coat, 1-bake metallic paint obtained in Production Example 13. (dry film thickness 30μ). Then, after setting at 20°C for 20 minutes, it was baked at 80°C for 30 minutes to obtain a cured coating film. As shown in Table 1, the resulting cured coating film had somewhat good weather resistance, but was excellent in coating appearance, moisture resistance, and cycle test. Example 7 The solid color paint obtained in Production Example 14 was tested with a mixed solvent to change the paint viscosity (Food Cup #4, 20°C,
23 seconds) and coated with air spray on a steel plate similar to that used in Example 1 (dry film thickness:
35μ). Then, after setting at 20℃ for 20 minutes,
A cured coating film was obtained by baking at 140°C for 30 minutes. As shown in Table 1, the obtained cured coating film had excellent coating appearance, weather resistance, and moisture resistance. Comparative Example 1 In Example 1, the metallic base enamel paint obtained in Production Example 6 was replaced with the metallic base enamel paint obtained in Production Example 15.
A cured coating film was obtained in the same manner as in Example 1. As shown in Table 1, the resulting cured coating had good coating appearance and weather resistance, but poor moisture resistance, some blistering, and cycle tests showed that the metallic base coating and the clear coating had good coating appearance and weather resistance. A whitening phenomenon occurred due to poor interlayer adhesion between the coating films. Comparative Example 2 In Example 4, a cured coating film was prepared in the same manner as in Example 4, except that the metallic base enamel paint obtained in Production Example 8 was replaced with the metallic base enamel paint obtained in Production Example 16. Obtained. As shown in Table 1, the resulting cured coating had good coating appearance and weather resistance, but poor moisture resistance, some blistering, and cycle tests showed that the metallic base coating and the clear coating had good coating appearance and weather resistance. A naturalization phenomenon occurred due to poor interlayer adhesion between the coating films. Comparative Example 3 In Example 5, the same procedure as in Example 5 was carried out except that the 1-coat, 1-bake metallic paint obtained in Production Example 12 was replaced with the 1-coat, 1-bake metallic paint obtained in Production Example 17. , a cured coating film was obtained. The obtained cured coating film had good coating appearance and moisture resistance, but the gloss decreased in weather resistance and cycle tests. Comparative Example 4 In Example 6, the procedure was the same as in Example 6, except that the 1-coat, 1-bake metallic paint obtained in Production Example 13 was replaced with the 1-coat, 1-bake metallic paint obtained in Production Example 18. , a cured coating film was obtained. The obtained cured coating film had good coating appearance and moisture resistance, but the gloss decreased in weather resistance and cycle tests.

【table】

【table】

Claims (1)

[Scope of Claims] 1 (A)(a) Fluorine-containing copolymer containing hydroxyl group 2
~70% by weight, and (b) 30-98% by weight of a copolymer containing an alkyl ester of acrylic acid or methacrylic acid (the alkyl group has 10 to 18 carbon atoms) and other acrylic monomers and containing a hydroxyl group. and (B) a curing agent containing a functional group that reacts with a hydroxyl group. 2. The copolymer mixture is 60 to 95% by weight, and the curing agent containing a functional group that reacts with a hydroxyl group is an alkyl etherified amino resin, in a mixing ratio of 5 to 40% by weight. Thermosetting resin composition for paint according to item 1. 3. Claim 1, wherein the curing agent containing a functional group that reacts with a hydroxyl group is an isocyanate-based compound, and the mixing ratio with the copolymer mixture is from 0.5 to 1.5 in molar ratio of isocyanate group/hydroxyl group. Thermosetting resin composition for paints as described in 2.