JPH0418967A - Painting and finishing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a new and useful paint finishing method.

More specifically, the present invention uses top clear paint and L,
The present invention relates to a painting finishing method which comprises using a specific curable resin composition comprising a carboxyl group-containing vinyl polymer and a compound having both an epoxy group and a hydrolyzable silyl group in one molecule.

, Prior Art] In recent years, in automotive topcoating, not only metallic paint finishing methods in which paints containing metallic powder are applied, but also so-called solid color finishing methods in which paints containing colored pigments are applied, have been developed using base coats. After applying the paint, apply the top coat paint,
- The effectiveness of the so-called 2-coat, 1-bake finishing method, which involves baking at times, has been recognized.

In other words, the paint film obtained by this 2-coat, 1-bake finish is superior in appearance and texture, and is particularly superior to vinyl, which conventionally had significant shortcomings in weather resistance. For solid color paints whose main component is a polymer, such a two-coat, one-bake finish52 results in a coating film with poor weather resistance. There is a point.

Generally, such two-coat painting finishing method is as follows:
Apply amino alkyd resin paint or thermosetting acrylic resin paint as a base coat paint, leave it for 2 to 5 minutes to develop enough solvent to remove it, and then immediately apply the same type of door/vehicle paint. The coating is coated and then cured by baking at a temperature in a hot air drying oven of 140 to 150°C for 20 to 30 minutes.

However, in most cases, acrylic melamine clear paints are used as top coat paints from the viewpoint of weather resistance, and one drawback of this system is poor acid resistance. This is an issue related to acid rain, which has rapidly become a problem in recent years.For example, the appearance of the painted surface of a new car has been significantly damaged due to acid rain, and measures such as repainting have been taken. It is also related to the fact that so much damage has been caused that it is necessary to take action. in this way,
In the automotive top coating method, there is a strong need for the immediate development of a two-coat, one-bake paint with excellent film appearance and acid resistance.

;Problems to be Solved by the Invention] In order to meet the various demands of the industry mentioned above, the present invention provides a two-coat coating film that can provide a composite coating film with excellent coating appearance and acid resistance.
In addition to providing a one-bake painting finishing method, it is also an object to provide a three-coat, two-bake painting finishing method, and this is the problem to be solved by the present invention.

[Means for Solving the Problems] Therefore, in view of the drawbacks of the prior art described above and the strong demands of the industry, the inventors of the present invention, as a result of intensive studies, have found the following.
A resin composition consisting of a specific polyol component mixed with a polyisocyanate component or aminoplast is used as a base coat T4 material resin, and then a curable resin with a specific functional group (reactive group) is used as a top coat resin. It has been discovered that the above-mentioned required performance can be dramatically improved by using a resin, and the present invention has been completed.

That is, the present invention is based on the following: A door book clear paint and a curable paint comprising a carboxyl group-containing vinyl resin and a compound having both an epoxy group and a hydrolyzable noryl group in one molecule. It is an object of the present invention to provide a painting finishing method comprising the use of a resin composition, particularly a so-called laminated painting finishing method such as a two-coat/one-bake painting finishing method or a three-coat/two-bake painting finishing method.

Specifically, a base coat paint (BC-1) comprising a curable resin containing metallic powder and a 7' or colored pigment as essential components for forming a paint film is applied, and then the resulting paint Provides a two-coat, one-bake painting finishing method comprising coating a surface with a top clear paint (T(,-1) made of the above-mentioned specific curable resin composition, and then curing each coating film at the same time. At the same time, the above base coat paint (BC-1) is applied, and then S
The above specific door clear paint (T(, -1) is applied and each coating film is cured at the same time, and after a while, this top clear paint is further applied and cured again. In the 3-coat, 2-bake painting finishing method, the above base coat paint (BC-
As the resin component constituting 1), a resin composition formed by blending polyisocyanate (C) or aminoplast (D) with vinyl polymer polyol (A) or polyester polyol (B) is used, while the above-mentioned As a clear paint for top coat (TC-1), it contains a carboxyl group-containing vinyl polymer (E) and a compound (F) that has both an epoxy group and a hydrolyzable silyl group in one molecule as essential components. If necessary, a catalyst (G
) and/or the reaction catalyst (H
) The present invention aims to provide a coating finishing method (laminate coating finishing method) comprising forming a composite cured coating film by using a curable resin composition comprising the following.

Here, first of all, the above-mentioned paint for skort (
A vinyl polymer polyol (A) that constitutes B(,-1) and is one of the essential components of the base coat coating composition.
is obtained by using a hydroxyl group-containing vinyl monomer (a-1) as an essential monomer component and, if necessary, also using another copolymerizable vinyl monomer (a-2),
Among them, as the hydroxyl group-containing vinyl hexamer (a-1), hydroxyalkyl (meth)acrylates such as β-hydroxyethyl (meth)acrylate, β-hydroxypropylene (meth)acrylate or β-hydroxybutyl (meth)acrylate are used. At first, N-methylolated (meth)acrylamide, "Plaxel FM
, FA” series [Daicel Chemical Industries, Ltd. product] YarTO
NET"FI-100, (a product of Union Carbide), which is made by adding ε-caprolactone to β-hydroxyethyl (meth)acrylate, or is represented by the common name polypropylene +, 1-coll methacrylate. 2-T + Rubbing 7 Blenmar P P-1000- and polyethylene glycol monomethacrylate "Both Blenmar PE and Freeze 5 products are manufactured by Nippon Oil & Fats ■:" Various unsaturated carboxylic acids such as acrylic acid, maleic acid, fumaric acid or icconic acid, and 1 Cardila El (glycidyl ester of branched fatty acids manufactured by Shell), glycidyl octylate ester or glycidyl coconut oil fatty acid. Typical examples include adducts of monovalent carboxylic acids with monoepoxy compounds typified by monoglycidyl esters such as esters or monoglycidyl ethers such as butyl glycidyl ether.

Next, typical copolymerizable vinyl monomers (a-2) other than the hydroxyl group-containing vinyl monomer (a-1) include alkyl (meth) having an alkyl group of C8 to C2□ in the side chain. Acrylate, styrene, vinyltoluene, t-butylstyrene, α-methylstyrene, glycidyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, (meth)acrylonitrile,
Including cyclohexyl (meth)acrylate, diesters of maleic acid or fumaric acid and C2-C18 monohydric alcohols, N,N-dialkylaminoalkyl (meth)acrylates, or phosphoric acid group-containing (meth)acrylates, These include vinyl acetate and fluorine-containing vinyl monomers such as hexafluoropropylene and tetrafluoroethylene. Of course, these vinyl monomers (a-2) may be used alone or in combination of two or more types depending on the desired coating film performance.

The vinyl polymer polyol (A) can be obtained by a known and commonly used method using the monomers listed above, such as a solution polymerization method using a radical generator.

-4. The polyester polyol (B) contains a polybasic acid such as isophthalic acid, phthalic anhydride, succinic anhydride, adipic acid or trimellitic anhydride, benzoic acid or P-tert-butylbenzoic acid as an acid component. Using a monobasic acid such as an acid, remove the 7/l/:l component and prepare neopentyl alcohol, trimethylolethane, trimethylolpropane, 1,6-hexanediol,
, 5-bentanediol, pentaerythritol, glycerin or ethylene glycol, as appropriate.
be synthesized. The polyester polyol may also be oil-modified, and usually has an oil length of 30% or less, and in terms of compatibility with resins and weather resistance, non-drying oils, especially coconut oil or its fatty acids or octylic acid, are used. or a monoglycidyl ester of a synthetic fatty acid such as "Cardura E".

Next, representative examples of the polyisocyanate I (C) which is a curing agent component of the various polyol components listed above include aromatic diisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, or xylene diisocyanate; tetramethylene diisocyanate; , aliphatic diisocyanates such as hexamethylene diisocyanate or trimethylhexane diisocyanate; isophorone diisocyanate, methylcyclohexane-2,4-(or 2,6-) diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate) or 1,3-( Alicyclic diisocyanates such as diisocyanate methyl)-cyclohexane, and polyhydric alcohols such as ethylene glycol, propylene glycol, neopentyl glycol or trimethylolpropane; having a functional group that reacts with isocyanates. , extremely low molecular weight polyester resins (including oil-modified types); or adducts with water etc., biuret forms, or isocyanates containing isocyanates (oligomers) obtained by polymerizing the above diisocyanates. ), etc.

In addition, at least one polymerizable inorganic compound in the molecule is represented by isocyanate ethyl (meth)acrylate, isocyanate propyl (meth)acrylate, isocyanate butyl (meth)acrylate, methacryloylisonanate, or isophorbenyl isocyanate. A copolymer of one or more vinyl monomers having both a saturated bond and an isocyanate group and a vinyl monomer other than the above-mentioned hydroxyl group-containing vinyl monomers can also be used as the polyisocyanate compound. Among the isocyanates, it is preferable to use polyisocyanate prepolymers, which are reaction products of aliphatic diisocyanates and polyhydric alcohols, in terms of weather resistance and low toxicity.

The blending ratio of these polyisocyanates (C) and the vinyl polymer polyol (A) or polyester polyol (B) is OH group/NCO group -1
A range of 10.5 to 1/3 (equivalent ratio) is preferable from the viewpoint of coating film performance.

On the other hand, typical examples of Aminoplus (D) which is a curing agent component of the various polyol components mentioned above include urea formaldehyde resin and melamine formaldehyde resin.

Carboxyl group-containing vinyl polymer (
E) is a carboxyl group-containing vinyl monomer (e-1)
is an essential component, and can be obtained by using other copolymerizable vinyl monomers (e2) as required. Such vinyl monomer (e-1) is (meth)
Carboxyl group-containing monomers such as acrylic acid, itaconic acid, maleic acid, fumaric acid, vinyl benzoate or vinyl p-tert-butylbenzoate are particularly representative, and other copolymerizable vinyl monomers (
e-2) as listed above, respectively (a-1
The hydroxyl group-containing vinyl monomer () and various molars (a-2) can be used. The carboxyl group-containing vinyl polymer (E) can be obtained by a known and commonly used method, for example, a radical solution polymerization method. In order to prepare the vinyl polymer (E) using the various vinyl monomers listed above, 0.5 of the carboxyl group-containing vinyl monomer (a-1) is required.
-100% by weight, preferably 1-70% by weight and 99.9% by weight of other vinyl monomers (e-2) copolymerizable therewith.
5 to 0% by weight, preferably 99 to 30% by weight, may be copolymerized.

To prepare the vinyl polymer (E) from the various monomers listed in F below, any conventionally known polymerization method can be applied, but the solution radical polymerization method is the simplest. .

Typical solvents used in this process include:
Toluene, xylene, cyclohexane, n-hexane,
Various hydrocarbons such as octane; methanol, ethanol, 1so-propanol, n-butanol, 1so-
Various alcohols such as butanol, Sec-butanol, ethylene glycol monomethyl ether; various esters such as methyl acetate, ethyl acetate, n-butyl acetate, amyl acetate; or acetone, methyl ethyl getone, methyl isobutyl ketone, cyclohexanone. There are various types of ketones, and these can be used alone or in combination.

Polymerization may be carried out in a conventional manner using such solvents and various known and commonly used radical polymerization initiators such as ab-based or peroxide-based radical polymerization initiators. Chain transfer agents such as lauryl mercaptan, octyl mercaptan, dodecyl mercaptan, 2-mercaptoethanol, octyl thioglycolate, 3-mercaptopropionic acid or α-methylstyrene dimer can also be used as agents.

Next, as the compound (F) having both an epoxy group and a hydrolyzable silyl group in one molecule, a vinyl polymer having both of these types of reactive groups and a silane cup having an epoxy group are used. A typical example is a ring agent.

Herein, such a hydrolyzable silyl group is defined by the general formula %.
2 is also a halogen atom:'! It represents an alkokynyl group, an acyloxy group, or a phenokynodi group, and a is a natural number of 0.1 or 21.
It refers to reactive groups that are easily hydrolyzed such as halosilyl group, alkoxysilyl group, acyloxysilyl group, phenoxysilyl group, iminooxysilyl group, or alkenyloxysilyl group shown in 1.

In order to prepare the vinyl polymer (F) having a specific re-reactive group as described above, any known method can be used. (meth)acryloyloxypropylmethyldimethoxysilane, r-(meth)acryloyloxypropyltriisopropenyloxysilane,
hydrolyzable silyl groups such as r-(meth)acryloyloxypropyltriiminooxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyl(tris-β-methoxyethoxy)silane, vinyltriacetoxysilane or vinyltrichlorosilane. and vinyl monomers having an epoxy group such as (β-methyl)glycidyl (meth)acrylate, allyl glycidyl ether, di(β-methyl)glycidyl maleate or di(β-methyl)glycidyl fumarate. If necessary, the amino group-containing vinyl monomer can be copolymerized with the various monomers listed above as other vinyl monomers that can be copolymerized with the amino group-containing vinyl monomer. , or ■T-mercaptopropyltrimethoxysilane, T-mercaptopropyltriethoxysilane,
γ-Mercaptopropylmethyldimethoxysilane, T-
In the presence of a chain transfer agent such as mercaptopropyltriisopropenyloxysilane or T-mercaptopropyltriiminooxysilane, a monomer mixture containing the above-mentioned epoxy group-containing vinyl monomers as an essential component is converted into a solution radical. A simple method includes (co)polymerization.

Then, by the above-mentioned method (■), the compound is obtained! ! ! 7
Of course, in preparing 1(F), the hydrolyzable silyl group-containing monomers mentioned above can also be used in combination.

Next, typical examples of the above-mentioned epoxy group-containing silane coupling agents include γ-glycidoxyprobyltrimethoxysilane, γ-glycidoxyprobyltriethoxysilane, and T-glycidoxypropylmethyljet. Addition of glycidol with toxysilane, T-glycidoxypropyltriisopropenyloxysilane, T-glycidoxypropyltriiminooxysilane, γ-isocyanatepropyltriisoprobenyloxysilane or T-isocyanatepropyltrimethoxysilane, etc. thing:
Alternatively, it may be an adduct of T-aminopropyltrimethoxysilane or the like and a jepoxy compound.

The curable resin composition (TC-1) used in the practice of the present invention comprises the catalyst (G) for hydrolysis to condensation of hydrolyzable silyl groups mentioned above and/or the vinyl polymer mentioned above. When the reaction catalyst (H) between the carboxyl group of (E) and the epoxy group of compound (F) is added, - layer,
Good curability can be obtained.

Typical examples of such catalysts (G) include basic compounds such as sodium hydroxide, lithium hydroxide, potassium hydroxide or sodium methylate; tetraisopropyl titanate, tetrabutyl titanate, tin octylate, lead octylate. , cobalt octylate, zinc octylate, calcium octylate, lead naphthenate, cobalt naphthenate, dibutyltin diacetate, di-n-butyltin dioctate, dibutyltin dilaurate or di-n-butyltin malate; Alternatively, there may be acidic compounds such as p-toluenesulfonic acid, trichloroacetic acid, phosphoric acid, monoalkylphosphoric acid, dialkylphosphoric acid, monoalkylphosphoric acid or dialkylphosphoric acid, monoalkylphosphorous acid or dialkylphosphorous acid.

Typical catalysts (H) include imidazoles such as imidazole, 2-methylimidazole, and 2-dodecylimidazole; amines such as triethylamine and tributylamine; tetrabutylammonium chloride, cetyltrimethylammonium Examples include quaternary ammonium salts such as bromide; and phosphorus-containing compounds such as triphenyl phosphate, triethyl phosphate, and triphenylphosphine.

From the (E) and (F) ingredients listed above, and further from the (G) and/or (H) ingredients, so-called so-called 2-coat 1-bake method, 3-coat 2-bake method, etc. To for laminated paint finish.

In order to prepare a curable resin composition for clear paint for coating (TC-1), the amount of epoxy groups present in component (F) is 0.1 equivalent to 1 equivalent of carboxyl group present in component (E). What is necessary is just to mix|blend in the ratio which becomes about 2-5 equivalent. In addition, (G) and/or (H
) component with respect to the total amount of both components (E) and (F).
．． It may be added in an amount of about 0.01 to 10% by weight.

The room temperature curable resin composition further includes, if necessary,
Filled with organic or inorganic pigments, fluidity regulator,
Color separation inhibitors, ultraviolet absorbers or antioxidants, etc.
Various known and commonly used additives; cellulose derivatives such as nitrocellulose or cellulose acetate butyrate; or various resins such as chlorinated polyethylene, chlorinated polypropylene, petroleum resin, or chlorinated rubber are added or blended. You can also do that.

In order to carry out the painting finishing method of the present invention using each resin composition obtained as described above, first, a base coat paint (BC-1) is applied as a second layer, and a semi-dry or dry state is applied. After reaching 1, apply top coat paint (TC-1) as a second layer, and then apply 1
What is necessary is just to heat-cure for 20 to 40 minutes at a temperature of about 20 to 160°C.

When carrying out the painting finishing method of the present invention as described in 2), the respective base coat paints and), 7,
Air spray painting methods and electrostatic spraying methods are suitable for achieving the full cosmetic effect, and the film thickness (dry film thickness) of base coat paints is Thickness (same below) is 5 to 5
The thickness of the top coat paint is preferably within the range of 10 to 100 microns, preferably 10 to 60 microns. A range of microns is appropriate.

In addition, the coating interval between the base coat and top coat is within the range of 1 to 45 minutes at a temperature of approximately 20°C.
Preferably, the range of 2 to 20 minutes is appropriate;
Further, when the base coat film is forced to dry, it is only necessary to heat it with warm air at 60 to 80'C for 0.5 to 5 minutes.

That is, the l-knob coat is preferably applied after the base coat film has reached a touch-dry or semi-hardened state under the drying conditions as described above.

On the other hand, in the case of heat drying a top coat, drying with hot air at 120 to 160°C for about 20 to 40 minutes is usually preferable in terms of curability and productivity. There is no problem in changing these drying and curing conditions as appropriate depending on the types and properties of the base coat paint (BC-1) and top coat paint (TC-1). .

The painting finishing method of the present invention can be applied to any field and any object to be coated in which the 2-coat/1-bench method or the 3-coat/2-bench method is adopted. In particular, including automobile painting, etc.
Desirable for products in heavy industry related fields such as electric heaters, escalator tractors, and bulldozers.

[Example] Next, the present invention will be specifically explained based on reference examples and examples. In the following, all parts and percentages are based on weight unless otherwise specified.

15 Example I Preparation example of C vinyl polymer polyol (A)] 560 parts of toluene and 240 parts of n-butyl acetate were added to a reaction vessel equipped with a stirring device, a thermometer, a reflux condenser tube, and a nitrogen introduction tube. The temperature was raised to 80'C under a nitrogen atmosphere, and 450 parts of methyl methacrylate, 390 parts of ethyl acrylate, 150 parts of β-hydroxyethyl methacrylate, 10 parts of methacrylic acid, and azobisisobutyronitrile (AIBN) were added. ), 10 parts of tert-butyl peroxyoctoate (TBPO), 140 parts of toluene, and 60 parts of n-butyl acetate were added dropwise over a period of 4 hours, and the temperature was maintained at the same temperature after the completion of the addition. When the polymerization reaction was continued by holding for 8 hours at g
A solution of the desired polyol was obtained.

Hereinafter, this will be abbreviated as polyol (A-1).

Reference Example 2 (Preparation example of 71 ester polymer, 1ol (B); In a reaction vessel equipped with a stirrer, a thermometer and a water separator, 200 parts of isophthalic acid, 200 parts of phthalic acid, and 237 parts of adipic acid were added. 365.3 parts of neopentyl glycol and 124 parts of trimethylolpropane,
While stirring, the temperature was raised to -)180°Ct.

Next, the temperature was raised from 180°C to 230°C at a constant rate over 5 hours, and then
It was held at 30'C.

Furthermore, 720 parts of xylene was gradually added to switch to the azeotropic condensation method. The acid value of the resin was monitored while the reaction temperature was maintained at 230°C, and the reaction was terminated when the acid value reached 4.0.

The solution of the target polyester polyol thus obtained had a hydroxyl value of 54 and a nonvolatile content of 60%. Hereinafter, this will be abbreviated as polyol (B-1).

Reference Example 3 [Preparation example of carboquine group-containing vinyl polymer (E)] 200 parts of xylene and 100 parts of n-butanol were charged into a reaction vessel equipped with a stirring device, a thermometer, a reflux condenser, and a nitrogen introduction tube. The temperature was raised to 125°C under a nitrogen atmosphere, and 120 parts of styrene, 240 parts of methyl methacrylate, 180 parts of butyl acrylate, 10 parts of methacrylic acid, 6 parts of azobisisobutyronitrile, and tertiary fluoride were added. A mixture of 9 parts of rhubarb octoate and 100 parts of xylene was added dropwise over a period of 6 hours.

After the dropwise addition, the same temperature was maintained for 8 hours to continue the polymerization reaction, and the nonvolatile content was 60.5%, the viscosity was W-X, and the solution acid value was 39 (KOH/g > A solution of polymer (E) was obtained, which will be abbreviated as polymer (E-1).

Reference Example 4 (same as above) A non-volatile sample was prepared in exactly the same manner as Reference Example 3, except that methacrylic acid was not used at all, and instead, 5 parts of acrylic acid and 5 parts of fumaric acid were used in combination. 61.2%, viscosity is Y, and solution acid value is 33.1
A solution of the desired polymer (E) (mgKOH7'g) was obtained. This is abbreviated as polymer (E-2).

Reference Example 5 (same as above) Instead of acrylic acid and fumaric acid, 120 parts of methyl methacrylate, 240 parts of butyl methacrylate,
A nonvolatile content of 59.8% and a viscosity of 7 were prepared in the same manner as in Reference Example 3, except that 60 parts of 2-ethylhexyl acturate and 180 parts of methacrylic acid were used.
1 to Z2, and the solution acid value is 117 (■KO) I/g
) A solution of the desired polymer (E) was obtained. This is made into a polymer (
It is abbreviated as E-3).

Reference Example 6 (Example of Preparation of Compound (F) Having an Epoxy Group and a Hydrolyzable Silyl Group) 300 parts of xylene was charged into the same reaction vessel as in Reference Example 3, and the temperature was raised to 110°C under a nitrogen atmosphere. Warm and add 168 parts of glycidyl methacrylate, 150 parts of T-methacryloyloxypropyltrimethoxysilane, 282 parts of ethyl acrylate, 03 parts of AIBN, 18 parts of TBPO.
A mixture of 100 parts of xylene and 100 parts of xylene was added dropwise over a period of 6 hours, and even after the addition was completed, the polymerization reaction was continued by maintaining the same temperature for 3 hours. A solution of the target compound (F) having B-C and an epoxy equivalent of 838 was obtained. This is compounded with Th(F-
It is abbreviated as 1).

Examples 1 to 5 and Comparative Example 1 The respective resin solutions obtained in Reference Examples 1 to 6 and the first
The various compounds shown in the table are made into paints separately according to the formulation shown in the table by a conventional method.
After preparing a topcoat clear paint with a carboxyl group/epoxy group-1/1 (equivalent ratio) and a base coat paint, xylene/toluene/ethyl acetate-301 was prepared.
It was diluted to a spray viscosity with a mixed solvent of 50/20 (weight ratio). Next, a uniform air bath was applied so that the dry film thicknesses of the base coat paint and the T-7 coat clear paint were 15 microns and 40 microns, respectively, and the interval between coatings of these two paints was 2 minutes. - and then heated at 140°C for 25 minutes to obtain a cured coating.

Next, the physical properties of each cured coating film thus obtained were evaluated, and the results are summarized in the same table.

Example 6 In Example 2, the base coat paint and the top coat clear paint were respectively applied and heated, and then the same top clear paint was applied on top of the cured paint film until the dry film was 40%. The coating was layered with air spray so as to have a micron thickness, and then dried under heating at 140° C. for 20 minutes to obtain a cured coating film.

Thereafter, various performances of the thus obtained cured coating film were evaluated, and the following results were obtained.

A gold sand coating film can be formed.

Therefore, according to the method of the present invention, the product is more acid resistant than when using conventional paints such as thermosetting acrylic resin paints and amino alkyd resin paints, and also has a good painted finish. can.

Claims (1)

[Scope of Claims] 1. A curable resin composition containing as essential components a carboxyl group-containing vinyl polymer and a compound having both an epoxy group and a hydrolyzable silyl group in one molecule, as a top clear coating. A painting finishing method characterized by using. 2. The top clear paint must contain a carboxyl group-containing vinyl polymer, a compound having both an epoxy group and a hydrolyzable silyl group in one molecule, and a catalyst for hydrolysis or condensation of the hydrolyzable silyl group. A painting finishing method characterized by using a curable resin composition containing as a component. 3. As the base coat paint, a curable resin composition containing polyols and polyisocyanates or aminoplasts as essential components is used, while as the top clear paint, a carboxyl group-containing vinyl polymer and one molecule A painting finishing method characterized by using a curable resin composition containing as an essential component a compound having both an epoxy group and a hydrolyzable silyl group. 4. As the base coat paint, a curable resin composition containing polyols and polyisocyanates or aminoplasts as essential components is used, while as the top clear paint, a carboxyl group-containing vinyl polymer and one molecule It is characterized by using a curable resin composition containing as essential components a compound having both an epoxy group and a hydrolyzable silyl group therein, and a catalyst for hydrolysis or condensation of the hydrolysable silyl group. , Paint finishing method. 5. Apply a base coat paint containing a curable resin containing metallic powder and/or colored pigment as an essential component for forming a coating film, and then apply the curable resin as an essential component to the thus obtained painted surface. In the two-coat/one-bake finishing method, which consists of applying a top coat clear paint containing as an ingredient and then curing it, polyols and polyisocyanates or aminoplasts are essential as the base coat paint. A curable resin composition is used as a component, while the base coat clear paint is a curable resin containing a carboxyl group-containing vinyl resin and a compound having both an epoxy group and a hydrolyzable silyl group in one molecule. A painting finishing method characterized by using a composition. 6. Apply a base coat paint containing a curable resin containing metallic powder and/or colored pigment as an essential component for forming a coating film, and then apply a coating film of the curable resin to the thus obtained painted surface. Apply and harden the top clear paint that contains it as an essential component for forming.
Then, in a three-coat/two-bake finishing method consisting of further coating and curing this top clear paint, the base coat paint contains polyols and polyisocyanates or aminoplasts as essential components. On the other hand, as the top clear paint, a carboxyl group-containing vinyl polymer, a compound having both an epoxy group and a hydrolyzable silyl group in one molecule, and A painting finishing method characterized by using a curable resin composition containing a hydrolysis or condensation catalyst as an essential component. 7. Claim 1, wherein the compound having both an epoxy group and a hydrolyzable silyl group in one molecule has the above-mentioned epoxy group and hydrolyzable silyl group at the end of the main chain and/or at the side chain. The painting finishing method described in ~6. 8. The painting finishing method according to claims 3 to 6, wherein the polyol is at least one selected from the group consisting of vinyl polymers and polyesters.