JPH03157460A - Curing type coating composition - Google Patents

Abstract

PURPOSE:To provide a composition having excellent long period weather resistance and pigment dispersibility and used for curable coatings by compounding a copolymer comprising a polymerizable UV stable monomer, a hydroxyl group- containing polymerizable monomer, an acidic functional group-containing polymerizable monomer, etc., with a specific crosslinking agent. CONSTITUTION:(A) A copolymer prepared by copolymerizing a monomer composition comprising (i) a 0.1-10wt.% of a polymerizable UV stable monomer preferably represented by the formula (R1 is H or cyano; R2 and R3 are H or 1-2C alkyl; X is imino or O; Y is H, 1-18C alkyl, etc.), (ii) 2.0-50wt.% of a hydroxyl group-containing polymerizable monomer, (iii) 0.1-10wt.% of an acidic functional group-containing polymerizable monomer and (iv) 97.8-30wt.% of other monomers is compounded with a crosslinking agent and further dissolved or dispersed in a solvent to provide the objective composition suitable for electric appliances, building materials, woodworking products, etc.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a coating composition that has excellent weather resistance, and in particular, it relates to a coating composition that has excellent weather resistance over a long period of time, that is, excellent gloss retention. A curable coating composition that exhibits crack resistance, blister resistance, and yellowing resistance, and is capable of forming a coating film with excellent drying properties, curability, gloss, chemical resistance, solvent resistance, etc. It provides:

[Prior Art] Acrylic resin and/or methacrylic resin [Hereinafter, in this specification, when "acrylic and/or methacrylic" are collectively indicated, the expression "(meth)acrylic" will be used. One of the typical uses of the resin in the paint field is as a resin for curable paints. For example, a monomer having a hydroxyl group such as hydroxyethyl (meth)acrylate is polymerized or copolymerized with other monomers to obtain an acrylic polyol, and a suitable crosslinking agent such as a polyisocyanate compound or an aminoplast resin is added to this. It has been applied as a resin composition for curing type paints such as room temperature curing type or bake curing type.

Such resin compositions for curable coatings have the property of being highly durable, and are therefore used, for example, for coating automobiles, home appliances, steel equipment, building materials, and the like.

Various resins have traditionally been used as paint resins, but from the viewpoint of paint film durability, especially weather resistance, (meth)acrylic resins are superior to other alkyd resins and polyester resins. It is widely used in applications that require particularly good weather resistance, such as paints for automobiles and building materials.

However, the gloss retention in the accelerated weathering test (Sunshine Weather-Ometer) was only at the level of 2,000 hours, which was insufficient from the viewpoint of long-term weatherability. Therefore, one of the ways to improve it is to
Improvements have been made by mixing and blending known ultraviolet absorbers. Although this method is effective to some extent, its sustainability is poor in the long term due to volatilization, bleed-out, decomposition, etc. of the UV absorber, and significant improvement has not been achieved. Techniques for increasing weather resistance by copolymerizing UV-absorbing monomers have also been proposed (Japanese Patent Publication No. 61-42751). Although these are effective in improving weather resistance to a certain level, However, it has problems such as yellowing due to the above, and is not necessarily sufficient from the viewpoint of long-term weather resistance.

In addition, in recent years, there has been a strong demand for long-term weather resistance of paints due to the trend toward higher-grade automobiles and maintenance-free construction of large structures, and paints with excellent long-term weather resistance include silicone-based and fluorine-based resins. The composition containing the main ingredient is in the spotlight. In particular, fluororesins are known to have excellent gloss retention properties in accelerated weathering tests of 4,000 to 5,000 hours or more. However, it is still unsatisfactory in terms of aesthetic appearance such as gloss value and stickiness, and workability including pigment dispersibility, and there are also cost issues, which severely limits its use.

[Problems to be Solved by the Invention] The present invention has been made in view of the above-mentioned circumstances, and its purpose is to provide long-term weather resistance that cannot be obtained with conventional (meth)acrylic resins. Curing that provides a coating film with gloss retention of 4,000 to 5,000 hours in an accelerated weathering test and with excellent gloss, buildability, pigment dispersibility, etc. at a relatively low cost. The present invention aims to provide a mold coating composition.

[Means for Solving the Problems] The curable coating composition of the present invention comprises a polymerizable ultraviolet stable monomer (a), a hydroxyl group-containing polymerizable monomer (b), and an acidic functional group-containing polymerizable monomer. (c) and other polymerizable monomers (
A crosslinking agent (Y) is added to the copolymer (x) obtained by copolymerizing a polymerizable carmer containing d) as an essential component.
A compound having two or more functional groups capable of reacting with a hydroxyl group in one molecule is blended and dissolved or dispersed in a solvent. By crosslinking and curing the copolymer (X) with a crosslinking agent (Y), a coating film with excellent long-term weather resistance, solvent resistance, and chemical resistance is formed. .

[Function] The polymerizable ultraviolet-stable monomer (a) is an essential compound for imparting excellent weather resistance to the copolymer (X), and is particularly suitable for sterically hindered piperidinyl groups and polymerizable unsaturation. Prizes are given to substances having at least one group in the molecule, among which substances represented by general formula (I) are most typically used. That is, the substance represented by -formation (I) not only provides excellent weather resistance to the copolymer (X), but also improves the dispersibility of various pigments such as carbon black and the color mixing stability in composite pigment systems. The effect is also remarkable.

[In the formula, R1 is a hydrogen atom or a cyano group, R2゜R5 is each independently a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, X is an imino group or an oxygen atom, and Y is a hydrogen atom or a cyano group having 1 to 18 carbon atoms. Alkyl group also OR, R.

In the above definition, the alkyl group having 1 to 2 carbon atoms represented by R2 and R5 is methyl or ethyl, and the alkyl group having 1 to 18 carbon atoms represented by Y is (methyl, ethyl, propyl, Straight-chain or branched, represented by isopropyl, butyl, isobutyl, tertiary butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, etc. Hydrocarbon residues are indicated.

To exemplify more specific compound salts, examples of the polymerizable ultraviolet stable monomer (a) include 4-(meth)acryloyloxy-2°2.6.6-tetramethyl. piperidine, 4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 4-(
meth)acryloyloxy-1゜2.2,6.6-pentamethylpiperidine, 4-(meth)acryloylamino-1,2,2,6,6-pentamethylpiperidine, 4-
Cyano-4-(meth)acryloylamino-2,2,6
, Ii-tetramethylpiperidine, 1-(meth)acryloyl-4-(meth)acryloylamino-2,2,6
, 8-tetramethylpiperidine, 1-(meth)acryloyl-4-cyano-4-(meth)acryloylamino-
2,2,8゜6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 4-crotonoylamino-2,2,6,6-titramethylbiveridine, Examples include 1-crotonoyl-4-crotonoyloxy-2,2,6,6-titramethylbiperidine, and one type or two or more types of these can be used.

Examples of the hydroxyl group-containing polymerizable monomer (b) include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and caprolactone-modified hydroxy(meth)acrylate [for example, brand name Plaxel F
M, manufactured by Daicel Chemical Industries, Ltd.], and polymerizable monomers having hydroxyl groups such as mono(meth)acrylate of polyester diol obtained from phthalic acid and propylene glycol.

Examples of the acidic functional group-containing polymerizable monomer (c) include:
Polymerizable monomers containing carboxyl groups such as (meth)acrylic acid, crotonic acid, itaconic acid, maleic acid and maleic anhydride; containing sulfonic acid groups such as vinylsulfonic acid, styrenesulfonic acid and sulfoethyl (meth)acrylate. Polymerizable monomer: 2-(meth)acryloyloxyethyl acid phosphate, 2-(meth)acryloyloxypropyl acid phosphate, 2-(
Examples include acidic phosphoric acid ester polymerizable monomers such as meth)acryloyloxy-3-chloropropyl acid phosphate and 2-methacryloyloxyethylphenyl phosphoric acid.

Other polymerizable monomers (d) include, for example, methyl (meth)acrylate, ethyl (meth)acrylate,
Propyl (meth)acrylate, isopropyl (meth)
Acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, tertiary butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, methyl (Meth)acrylic acid alkyl esters such as cyclohexyl (meth)acrylate and tertiary butyl cyclohexyl (meth)acrylate; Epoxy group-containing polymerizable monomers such as glycidyl (meth)acrylate; (meth)
Nitrogen-containing polymerizable monomers such as acrylamide, N,N'-dimethylaminoethyl (meth)acrylate, vinylpyridine, and vinylimidazole; halogen-containing polymerizable monomers such as vinyl chloride and vinylidene chloride; styrene,
Aromatic polymerizable monomers such as α-methylstyrene and vinyltoluene; vinyl esters such as vinyl acetate: vinyl ether; polymerizable cyanide compounds such as (meth)acrylonitrile; and optionally 2,4-dihydroxybenzophenone or 2. 2°, 2-hydroxy-4-'(3-(meth)acryloxy-2-hydroxypropoxy]benzophenone obtained by reacting 4-trihydroxybenzophenone and glycidyl (meth)acrylate,
Examples include polymerizable ultraviolet absorbing monomers such as 2,2°-dihydroxy-4-[3-(meth)acryloxy-2-hydroxypropoxy]benzophenone, and one selected from these groups or Two or more types can be used.

The above monomers (a), (b), (c) and (
Each of the above monomers (a), (b), (c) in the case of producing copolymer (X) from monomer components containing d)
) and (d) are used at a ratio of 0.1 to 10% by weight of the polymerizable ultraviolet stable monomer (a), 2.0 to 50% by weight of the hydroxyl group-containing polymerizable monomer (b), and The functional group-containing polymerizable monomer (c) is used in an amount of 0.1 to 10% by weight and the other monomer (d) is used in an amount of 97.8 to 30% by weight.

Here, the amount of the polymerizable ultraviolet stable monomer (a) used is 0.
When the amount is less than 1% by weight, the resulting copolymer (X) has insufficient photostability. On the other hand, if the amount exceeds 10% by weight, if the curable paint composition is used as a paint, the gloss and texture of the dormitory paint film will be insufficient, leaving an unsatisfied appearance, and the solvent resistance will deteriorate.
Chemical resistance may be poor.

The amount of hydroxyl group-containing polymerizable monomer (b) used is 2.0% by weight
When the amount is less, the crosslinking agent (Y) of the copolymer (X) of the present invention
), the durability of the coating film, ie, solvent resistance, crack resistance, blister resistance, etc., decreases. If it exceeds 50% by weight, disadvantages such as inducing instability during polymerization and lowering the water resistance of the resulting coating film occur, so it is preferably 4.0 to 40% by weight.
It is recommended to use it in a range of 5.0 to 30% by weight, more preferably 5.0 to 30% by weight.

The acidic functional group-containing polymerizable monomer (c) exhibits a useful action as an internal catalyst in the reaction between the copolymer (X) of the present invention and the crosslinking agent (Y), and the amount used is 0.1% by weight. If it is less than that, the crosslinking reaction will be slow and the curing and drying properties will be insufficient.
If it is used in an amount exceeding 10% by weight, it not only induces instability during polymerization, but also reduces the water resistance of the resulting coating film, inhibits the action of UV-stable monomers, and makes it difficult to obtain long-term weather resistance. There may be disadvantages such as:

The other polymerizable vehicle (d) is preferably selected so as not to impair the woody characteristics of the present invention. For example, aromatic polymerizable monomers that are commonly used from the viewpoints of gloss, stickiness, solvent resistance, and chemical resistance are negative from the viewpoint of long-term weather resistance, which is a feature of the present invention. It is recommended that the content of the polymerizable monomer be 20% by weight or less, preferably 10% by weight or less, and more preferably 5% by weight or less in all components (a) to (d) of the polymerizable monomers. Furthermore, in order to more significantly express the long-term weather resistance that is the woody characteristic of the present invention, the content of methacrylic acid ester is 50% by weight.
The above is particularly preferable.

However, the methacrylic acid ester here refers to the polymerizable ultraviolet stable monomer (a), the hydroxyl group-containing polymerizable monomer (
Among the monomers consisting of b) and other polymerizable monomers (d), it means those having a polymerizable unsaturated group derived from a methacryloyl group.

In particular, cycloalkyl group-containing (meth)acrylate (II) is preferable for applications that require long-term weather resistance as well as a beautiful appearance such as gloss and texture. The cycloalkyl group-containing (meth)acrylate is also an advantageous substance in terms of controlling the glass transition temperature, which will be described below.

4 CH2=C(If) C=O -z (In the formula, R4 represents a hydrogen atom or an alkyl group having 1 or 2 carbon atoms, and 2 represents a cycloalkyl group which may have a substituent.) Represented by Z Examples of the cycloalkyl group in the cycloalkyl group which may have a substituent include monocyclic saturated hydrocarbon residues such as cyclopentyl, cyclohexyl, and cyclododecyl. These cycloalkyl groups are
It may have an alkyl group having 1 to 6 carbon atoms as a substituent, and the alkyl group in these substituents is
Methyl, ethyl, propyl, isopropyl, butyl.

Examples include isobutyl, tertiary butyl, pentyl, hexyl, heptyl, and the like.

To give more specific compound names and explain them, for example, cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, tertiary butylcyclohexyl (meth)acrylate, etc. A species or two or more species can be used.

In order to fully express the essential features of the present invention, the glass transition temperature of the copolymer (X) of the present invention, as measured using a differential scanning calorimeter (DSC), is preferably 120 to 80°C. It is desirable to design the temperature to be in the range of 0 to 60°C, more preferably 10 to 50°C. Copolymer (X)
If the glass transition temperature of the material is too low, the coating film will exhibit excessive flexibility, resulting in insufficient long-term durability; on the other hand, if the glass transition temperature is too high, the coating film will become hard and brittle. Therefore, there is a disadvantage in crack resistance and blister resistance. From these points of view, we have decided to recommend the above range.

The number average molecular weight of the copolymer (X) of the present invention is 2.0
00-30,000, preferably 3,000-10,0
00, more preferably in the range of 3,500 to B,000. Copolymer (X)
If the number average molecular weight of Y is too low, it will not be possible to obtain a coating film with sufficient durability when the crosslinking agent (Y) is blended into the paint composition, while if it is too high, it will become unstable during polymerization. This causes disadvantages such as smearing, high viscosity and lack of coating suitability. From these points of view, we have decided to recommend the above range.

Furthermore, even if the number average molecular weight satisfies the above preferred range, if the copolymer (X) contains 10% or more of components with a number average molecular weight of 1,000 or less, such low molecular weight components Copolymers (X
) is the content of components with a number average molecular weight of 1,000 or less.
It is recommended that it be less than 0%.

Next, a method for producing the copolymer (X) of the present invention will be explained. The copolymer (X) comprises the polymerizable UV-stable JIL polymer (a), the hydroxyl group-containing polymerizable monomer (b), the acidic functional group-containing polymerizable monomer (c), and other polymerizable monomers. Quantity (
It is obtained by polymerizing the polymerizable monomer component consisting of d) by a known method 2, such as solution polymerization, emulsion polymerization, suspension polymerization, or bulk polymerization.

Solvents that can be used when employing the solution polymerization method include aromatic hydrocarbons such as toluene and xylene; acetate esters such as ethyl acetate and butyl acetate; ketones such as methyl ethyl ketone and methyl isobutyl ketone; isopropanol, These organic solvents include aliphatic alcohols such as n-butanol and 1so-butanol; alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and diethylene glycol monoethyl ether; Used alone or as a mixed solvent. However, in the case of using the copolymer (X) in combination with a polyisocyanate compound in the present invention, it is necessary to use the above-mentioned aliphatic alcohols, alkylene glycol monoalkyl ethers, or water, etc. Solvents that exhibit activity are not preferred.

Examples of the polymerization initiator include common radical polymerization initiators such as azobisisobutyronitrile, benzoyl peroxide, and ditertiary butyl peroxide. These polymerization catalysts are used in an amount of 0.1 to 10% by weight based on the total amount of polymerizable monomers, and the reaction temperature is in the range of room temperature to 200°C, preferably 40 to 140°C. Furthermore, when carrying out the polymerization reaction, chain transfer agents and regulators such as lauryl mercaptan, 2-mercaptoethanol, carbon tetrachloride, and carbon tetrabromide may be used for the purpose of controlling the molecular weight, and alkyd resins and epoxy resins may also be used. etc. may be added to denature it.

Copolymer (X) having the above-mentioned suitable molecular weight can be obtained by such a solution polymerization method.

When the copolymer (X) obtained in the present invention is used as a water-soluble or water-dispersible type, it may be neutralized with a basic compound if necessary.

Examples of basic compounds that can be used include ammonia, triethylamine, morpholine, and sodium hydroxide.

As the crosslinking agent (Y) of the present invention, polyisocyanate compounds and aminoblast resins are preferable. For example, the polyisocyanate compounds include hexamethylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, and derivatives of these diisocyanates. Examples include certain adduct polyisocyanate compounds, polyisocyanate compounds such as cresol-blocked products of tolylene diisocyanate, and n-butanol-blocked products of xylylene diisocyanate, or blocked products thereof.
One or a mixture of two or more of these can be used.

Here, the blending amount of the polyisocyanate compound is preferably 0.6 to 1.4 equivalents of isocyanate groups per 1 equivalent of hydroxyl groups contained in the copolymer (X), and 0.6 equivalents. If it is less than that, it is difficult to obtain a durable coating film due to insufficient crosslinking, and water resistance, solvent resistance, crack resistance, and blister resistance may deteriorate. Also 1,
If the amount exceeds 4 equivalents, there will be disadvantages such as loss of gloss and stickiness of the coating film. More preferably 0.8-1
．． A range of 2 equivalents is recommended. Furthermore, it is recommended that the isocyanate groups be used in substantially the same equivalent amount as the hydroxyl groups contained in the copolymer.

Furthermore, in order to more clearly exhibit the yellowing resistance of the present invention, non-yellowing types such as hexamethylene diisocyanate and modified products thereof are particularly recommended.

In addition, examples of the aminoblast resin include methyl etherified melamine resin, butyl etherified melamine resin,
Butyl etherified benzoguanamine 84 resin, butyl etherified cyclohexyl benzoguanamine resin, etc. can be mentioned, and these 1f! ! Alternatively, a mixture of two or more types can be used.

The amount of aminoblast resin used is copolymer (X) 100
It is preferable to mix it in a ratio of 5 to 70 parts by weight. If the amount of aminoblast resin used is less than 5 parts by weight, crosslinking will be insufficient and it will be difficult to obtain a durable coating film, resulting in decreased water resistance, solvent resistance, crack resistance, and blister resistance. do. If it is used in an amount exceeding 70 parts by weight, there may be disadvantages such as loss of gloss and stickiness of the coating film, and as a result, the content of the copolymer (x) will be reduced, resulting in poor long-term weather resistance. It becomes difficult. It is recommended to use it preferably in a proportion of 10 to 55 parts by weight, more preferably 15 to 40 parts by weight.

The coating composition of the present invention contains a curing catalyst for accelerating the reaction, a solvent such as an organic solvent and/or water, a filler, a leveling agent, a dispersant, a plasticizer, a stabilizer, a dye, a pigment, etc. ! Paint additives, modifying resins (e.g. alkyd resins, epoxy resins, cellulose derivatives, chlorinated rubber, etc.)
etc. can be used by appropriately blending them.

Pigments used in the paint of the present invention include, for example, inorganic pigments such as white pigments such as titanium oxide, antimony trioxide, zinc white, lithopone, lead white, carbon black, yellow lead,
Coloring pigments such as molybdenum red, red iron oxide, yellow iron oxide, and yellow flower, and organic pigments include azo compounds such as benzidine and Hansa yellow, and phthalocyanines such as phthalocyanine blue, and one or more of these. can be used.

In addition, it is recommended to select pigments with good weather resistance so as not to reduce the weather resistance of the coating film.For example, for titanium oxide, which is a white pigment,
Using rutile-type titanium oxide provides better results in terms of weather resistance of the coating film than using anatase-type titanium oxide.

Even though it is referred to as a rutile type, chlorine-method titanium oxide is more preferable than sulfuric acid-based titanium oxide in terms of long-term weather resistance.

[Effects of the Invention] Since the coating composition of the present invention is obtained using a polymerizable monomer component having a specific composition, it has extremely excellent long-term weather resistance. Furthermore, since it has excellent pigment dispersibility, inorganic and organic pigments can be dispersed using known pigment dispersion methods to obtain colored paints.

The coating composition of the present invention has outstanding long-term weather resistance, the ability to form a coating film with excellent gloss, stickiness, and solvent resistance, and excellent workability, and is suitable for use in home appliances. product,
It can be used for a wide range of applications, including steel equipment, large structures, automobiles, building materials, and woodworking.

[Example] The present invention will be explained below using Examples and Comparative Examples.

Note that "1 part" or "1%" means parts by weight or % by weight, respectively, unless otherwise specified.

Production Example 1 25 parts of toluene and 25 parts of butyl acetate were charged under a nitrogen gas stream into a four-bottle flask equipped with a stirrer, a thermometer, a condenser, and a nitrogen gas inlet tube, and while the temperature was raised to 100°C, 4-
Methacryloyloxy-2゜2.13.6-tetramethylpiperidine 1.0 parts, cyclohexyl methacrylate 12.5 parts, butyl methacrylate 5.0 parts, stearyl methacrylate 6.0 parts, butyl acrylate 6.0 parts
10.0 parts of methyl methacrylate, 9.0 parts of hydroxyethyl methacrylate, 0.5 parts of methacrylic acid and 1.0 parts of azobisisobutyronitrile were added dropwise over 2 hours. Further at 100℃ 4
The copolymer of the present invention has a non-volatile content of 50.1
%, number average molecular weight 4,100 solution [copolymer solution (1
). Other special values are shown in Table 1.

(2 blank spaces below) Production Examples 2 to 12 and Comparative Production Examples 1 to 6 The polymerizable polymer, solvent, polymerization initiator, and temperature during the polymerization reaction used in Production Example 1 are shown in Tables 1 and 2. This is a manufacturing example except for the following! Repeat the same operation to prepare the copolymer solution (
2) to (!2) and comparative copolymer solutions (1) to (6)
) was obtained.Production Example 13 Into the same reactor used in Production Example 1, 40 parts of isopropyl alcohol was charged under a nitrogen gas stream, and the temperature was heated to 80°C.
4-methacryloyloxy-2,2
, 3 parts of 6,6-tetramethylbiperidine, 19.5 parts of cyclohexyl methacrylate, 10 parts of stearyl methacrylate, 8.0 parts of butyl acrylate, 12.5 parts of methyl methacrylate, 5 parts of hydroxyethyl acrylate.
, 0 parts of acrylic acid, and 2 parts of azobisisobutyronitrile were added dropwise over 4 hours, and after further holding at 80°C for 4 hours, 10.8 parts of triethylamine was added. The copolymer of the present invention was made into a solution with a nonvolatile content of 60.1% and a number average molecular weight of 6,500 [
Copolymer solution (13)] was obtained. Other characteristic values are shown in Table 1.

Comparative Production Example 8 A comparative copolymer solution (8) was obtained by repeating the same operation as Production Example 13, except that the polymerizable monomers used in Production Example 13 were changed as shown in Table 2. .

Copolymer solutions (1), (2) obtained in Examples 1, 2, 3, 4.5 and Comparative Examples 1, 2.3 Production Examples 1, 2.11 and Comparative Production Example 1.2゜7, (11) and comparative copolymer solutions (1), (2), and (7) were used to create curable coating compositions (1) to (5) and comparative curable coating compositions according to the formulations shown in Table 3. Things (1), (2),
(3) was obtained.

(Margins below 0) These paint compositions were spray-coated onto a white board that had been previously coated with two-component urethane resin enamel on a zinc phosphate-treated board, baked at 80 tons for 30 minutes, and dried for one day. The film thickness was 30 μm.

As shown in Table 4, the results show that Examples 6, 7, 8, 9, 10, 11 and Comparative Examples 4, 5. It
, 7 Production Examples 1, 5, 9, 10.12 and Comparative Production Example 1
, copolymer solutions (1), (5) obtained in 3.4,
Using (9), (10), (12) and comparative copolymer solutions (1), (3), (4), curable coating compositions (6), (7), and the formulations shown in Table 5 were prepared. (
8), (9), (10).

(11) and comparative curable coating composition (4),
(5).

(6) and (7) were obtained.

These coating compositions were spray-coated in advance onto a zinc phosphate-treated board, baked at 80° C. for 30 minutes, and dried for one day. The resulting test pieces were used to test coating film performance. The film thickness was 40 μm. As shown in Table 6, the results showed that it had excellent weather resistance.

Examples 12, 13, 14.15 and Comparative Examples 8, 9.1
Copolymer solutions (3), (4), (6) obtained in Production Examples 3.4 and 6.7 and Comparative Production Examples 5 and 6.7
(7) and comparative copolymer solutions (5), (13)
, (7) were used to obtain curable coating compositions (12) to (15) and comparative curable coating compositions (8), (9), and (1G) with the formulations shown in Table 7.

(Margin below.) These paint compositions were spray-coated onto a white board that had previously been coated with two-component urethane resin enamel on a zinc phosphate-treated board, baked at 160°C for 20 minutes, and then dried for one day. The coating performance was tested using the test piece obtained in this manner.As shown in Table 8, the coating film had excellent weather resistance.

(Left below) Example 18.17.18, 19, 20.21 and Comparative Example 11, 12゜13, 14.15 Production Example 1, 2.4.8 & Comparative Production Example 1.3.4 Obtained copolymer solutions (1), (2), (4),
(fl) and comparative copolymer solutions (1), (3)
, (4) were used to prepare curable coating compositions (16), (17), (18), (
19), (20).

(21) and comparative curable coating composition (11),
(12).

(13), (14), and (Is) were obtained.

These coating compositions were spray-coated onto a zinc phosphate-treated board, baked at 160'C for 20 minutes, and then dried for one day. Using test pieces obtained, coating film performance was tested. The film thickness was 40 μm. As shown in Table 10, the results show that the copolymer solutions (1
3) and the comparative copolymer solution (8) were used to prepare a curable coating composition (22) with the formulation shown in Table 11.Methylated melamine resin Sumimaru-405 80% aqueous solution (parts) Sumitomo Chemical ■ These curable paint compositions were spray-coated on a zinc phosphate-treated white board coated with two-component urethane resin enamel, baked at 140 x 20 minutes, and dried for one day. The coating performance was tested using

As shown in Table 12, the results showed that it had excellent weather resistance.

(Margin below)ゝゝ・ Table Note 1 Sunshine Weather-Ometer after 4000 hours (
(For gloss retention rate, time is shown in the table) Note 2 Surface condition after 10 days immersion in water 3 Surface condition judgment criteria after rubbing 100 times with a cloth moistened with xylene ◎ Excellent, ○ Good, Δ
Normal,
, (11), (16), (21) and comparative curable coating compositions (a), (7), (1
4).

(15) was mixed in the formulation shown in Table 'MS13 to obtain curable coating compositions (23), (24) and comparative curable coating compositions (17) and (18).

These curable paint compositions are spray applied to a tin plate, and when the paint film is half dry (it will become stringy if you touch it with your fingers), touch a part of the paint film with your fingers. The color difference between the rubbed surface and the sprayed surface thus obtained and the gloss value of the θ sprayed surface were tested. As shown in Table 13, the results showed that the pigment had excellent dispersibility.

(Margin below) (department)

Claims (11)

[Claims] (1) Polymerizable UV-stable monomer (a) 0.1 to 10% by weight, hydroxyl group-containing polymerizable monomer (b) 2.0 to 50% by weight, acidic functional group-containing polymerizable monomer ( c) 0.1-10% by weight and other polymerizable monomers (d) 97.8-30%
Weight% [However, the total of (a), (b), (c) and (d) is 10
A cross-linking agent ( 1. A curable coating composition characterized in that Y) is dissolved or dispersed in a solvent. (2) The polymerizable UV-stable monomer (a) has the general formula (I
) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (I) [However, in the general formula (I), R_1 is a hydrogen atom or a cyano group, and R_2 and R_3 are each independently a hydrogen atom or an alkyl having 1 to 2 carbon atoms. group; The curable coating composition according to claim (1), comprising the copolymer (X) according to claim (1). (3) Hydroxyl group 1 contained in the copolymer (X) using a polyisocyanate compound or its modified product as a crosslinking agent (Y)
The curable coating composition according to claim 1 or 2, wherein the isocyanate group is blended in a ratio of 0.8 to 1.4 equivalents. (4) The curable coating material according to claim (1) or (2), wherein aminoblast resin is blended as the crosslinking agent (Y) in a proportion of 5 to 70 parts by weight per 100 parts by weight of the copolymer (X). Composition. (5) Claims (1) to (4) wherein the content of styrene in all polymerizable monomer components (a) to (d) is 20% by weight or less.
The curable coating composition according to any one of the above. (6) The composition for a curable paint according to any one of claims (1) to (5), which contains 50% by weight or more of methacrylic acid and methacrylic acid ester in all polymerizable monomer components (a) to (d). thing. (7) The curable coating composition according to any one of claims (1) to (6), wherein the copolymer (X) has a glass transition temperature in the range of 0 to 60°C. (8) The number average molecular weight of the copolymer (X) is 3,000 to 1
0,000, the curable coating composition according to any one of claims (1) to (7). (9) The curable coating composition according to claim (8), wherein the component having a number average molecular weight of 1,000 or less in the copolymer (X) is less than 10%. (10) The curable coating composition according to any one of claims (1) to (9), which contains a pigment. (11) Claim in which chlorine-method titanium oxide is used as the pigment (
10) The curable coating composition described above.