JPS6230582A - Method for forming composite film - Google Patents

Abstract

PURPOSE:To form a high performance composite film three-dimensionally crosslinked and cured at ambient temp. or under heating at low temp., by using unsaturated resin paint containing a polymerization initiator as a base coat and urethane paint as a top coat. CONSTITUTION:In forming a composite film by a two-coat one-bake system, unsaturated resin paint based on a composition consisting of a polymerizable unsaturated group-containing resin, a polymerizable unsaturated vinyl monomer and a polymerization initiator is applied as a base coat. Subsequently, urethane paint based on an active hydrogen-containing resin and a polyisocyanate compound is applied as a top coat. Because both paints are crosslinked and curd in a temp. range from ambient temp. to about 120 deg.C, the formed composite film is also cured in the same temp. range and the composite film having the same capacity as one due to thermosetting resin is formed and the conservation of energy is also enabled.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a composite coating film, and more specifically,
The present invention provides a method for forming a three-dimensionally crosslinked and hardened composite coating film by heating at room temperature or low temperature.

Traditionally, metallic paints or solid color paints (base coats) containing metallic paints and/or coloring agents have been applied to the finishing of automobile bodies.
Next, after applying clear paint (top coat),
Composite coating films are often formed by the so-called two-coat, one-beta system in which both of these films are cross-linked and cured simultaneously by heating. The paints used in this method are mainly Amiha alkyd resin and Amiha acrylic.
□Heat-curable paints such as polyurethane resins and amino/borienether resins, and curing of composite coatings usually takes 1
This is done by heating to 40°C or higher, and the coating performance has almost reached a practical level [7].

However, based on the viewpoints of resource saving, energy saving, etc., we aim to have at least the same level of performance as the composite coating film produced by the heat curing method described above, and to cure the composite coating film at 140°C as described above.
There is a demand for the development of a method that can be carried out at a temperature as low as possible, so the present inventors have conducted extensive research into lowering the temperature lower than the two thermosetting paints mentioned above. As a result, the object of the present invention could be achieved by using a polyunsaturated resin-based paint containing a polymerization initiator as a base coat, such as a cretan-based paint.

That is, an unsaturated resin-based paint mainly composed of silk craftsmanship consisting of unexploded bait, polymerizable unsaturated group-containing G4 fat, a polymerizable unsaturated vinyl monomer, and a polymerization initiator is applied to the coating station 7 and then to the painted surface. An example of a method for forming a composite coating film is described below, in which a urethane-based paint containing active hydrogen-containing t\ fat and a polyisocyanate compound as the main components is applied, and the urethane-based paint is cured at room temperature or by heating.

Invented by Zero, the main purpose is to improve the conventional method of forming a composite coating film by high-temperature heating using the above-mentioned 2-coat-1-pater method. The unsaturated resin paint as a component is...
As a result, both of these PI-s are coated with urethane paints containing active hydrogen-containing resins and polyisocyanate compounds as main components.
Since cross-linking and curing occurs at a temperature of 20°C, the composite coating film formed by overcoating both of these pigments also cures within the same temperature range, and the cured coating film is equivalent to the composite coating film made of the thermosetting paint. It has higher performance than that, making it possible to save resources and energy.

Conventionally, the unsaturated resin-based paints have been known to have excellent chemical resistance, physical resistance, weather resistance, etc. when the surface of the coating film comes into contact with oxygen in the air, inhibiting curing and creating a sticky state. Although it has the following performance, it is not fully utilized. However, in the present invention, since the urethane-based paint is applied after the paint is applied and before curing inhibition occurs, the above-mentioned excellent performance can be fully utilized without causing curing inhibition.

Furthermore, since the method of the present invention allows crosslinking and curing at low temperatures as described above, it is easy to create composite coatings that have performance equivalent to or better than the thermosetting paints described above, even on plastics with low heat distortion temperatures. Just in case it is possible to form it. As a result, the entire exterior of automobiles, motorcycles, trucks, etc. whose parts or parts are being replaced by plastic materials, especially those where metal parts and plastic parts coexist, can be painted with a single paint. Next, a method for forming a composite coating film according to the present invention will be specifically explained.

Unsaturated resin paint: A paint containing an unsaturated composition as a main component, the unsaturated composition consisting of a polymeric unsaturated group-containing resin, a polymerizable unsaturated group additive, and a polymerization initiator. O First, the polymerizable unsaturated group-containing resin has 1 polymerizable unsaturated group.
The resin has at least two in its molecule, and the position thereof may be in the main chain, side chain, or terminal of the resin, and any known resin can be used. Specifically, (1) unsaturated polybasic acids having one or more polymerizable unsaturated groups and two or more carboxyl groups in one molecule (for example,
A polybasic acid component containing maleic acid, maleic anhydride, fumaric acid, citraconic acid, mesaconic acid, itaconic acid, tetrahydrophthalic acid, crotonic acid, aconitic acid, glutaconic acid, etc.) and two or more hydroxyl groups in one molecule. An unsaturated polyester in which a polymerizable unsaturated phase system is introduced into the main chain by esterifying a polyhydric alcohol component having In place of basic acids (e.g. succinic acid, adipic acid, glutaric acid, azelaic acid, 7-talic acid, etc.), unsaturated polyesters can be substituted with unsaturated basic acids such as acrylic acid and methacrylic acid. Unsaturated polyesters obtained by adding an unsaturated polybasic acid and introducing polymerized unsaturated groups into the side chains or terminals of (1) above, (2) hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, etc. Acrylic acid is methacrylic acid hydroxy □ dialkyl (C2
~24) A hydroxyl group-containing acrylic resin or vinyl resin □ is obtained by polymerizing a hexamer containing a hydroxyl group-containing vinyl monomer that is an ester, and the hydroxyl group in the hydroxyl group is
Acrylic resin or vinyl resin having a polymerizable unsaturated group in the side chain by adding the unsaturated basic acid or unsaturated polybasic acid; Acrylic resin or vinyl resin having a polymerizable unsaturated group in its side chain by adding the above-mentioned hydroxyl group-containing vinyl monomer to the carboxyl group in the acrylic resin or vinyl resin containing a saturated polybasic acid in its skeleton; The above-mentioned unsaturated-basic acid is added to the glycidyl group or epoxy group in the glycidyl group-containing acrylic resin, vinyl resin, or epoxy group-containing epoxy resin obtained by copolymerizing glycidyl group-containing monomers such as glycidyl acrylate and glycidyl methacrylate. Resin by adding a polybasic acid and introducing a polymerizable unsaturated group into the side chain,
■ Hydroxyl group-containing polyester or acrylic resin,
Cretashi-modified unsaturated polyester or unsaturated acrylic resin obtained by adding the above-mentioned hydroxyl group-containing vinyl monomer via a diisocyanate compound (see below); Examples include unsaturated polysiloxane resins to which a hydroxyl group-containing vinyl monomer is added, but the present invention is not limited to these, and any resin having a polymerizable unsaturated group may be used.

These polymerizable unsaturated group-containing resins have an unsaturation equivalent of about 2
The number average molecular weight is preferably in the range of 400 to 100,000, particularly preferably 600 to 30,000. Furthermore, in the present invention, among the above, polymerizable unsaturated group-containing resins having an acrylic resin (resin containing 10% by weight, especially 25% by weight of an alkyl ester of acrylic acid or methacrylic acid) as a main skeleton are particularly preferred. .

Next, the polymerizable unsaturated monomer is a low molecular weight compound having one or more polymerizable unsaturated groups in one molecule. Specifically, for example, acrylic acid, methacrylic acid, maleic acid,
Carboxyl group-containing monomers such as 7 malic acid: Hydroxyl group-containing vinyl monomers such as hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate: Glycidyl acrylate, glycidyl methacrylate, etc. Glycidyl group-containing monomers: methyl acrylate,
Alkyl acrylic acid or methacrylic acid (C1-18) such as methyl methacrylate, ethyl acrylate, ethyl methacrylate, isopropyl acrylate, n-butyl methacrylate, n-hexyl methacrylate, lacryl methacrylate, stearyl acrylate, etc.
Ester: ethylene glycol, diethylene 9”!J
Polyhydric alcohols such as nial, triethylene glycol, propylene glycol, tripropylene glycol, butylene glycol, 1,6-hexanediol, chrycerin, trimethylolethane, trimethylolpropane, pentaerythritol, dipene polyerythritol Di, tri, tetra, or hexaester of acrylic acid (and) or methacrylic acid: Esterified products of polybasic acids such as phthalic anhydride, adipic acid, succinic acid, and hexahydrophthalic anhydride with hydroxyl group-containing vinyl monomers: Allyl Alcohol, hydroxyl group-containing vinyl monomer,
Gooseberry alcohol, tarotonyl alcohol, hydroxydicyclopentadiene, cinnamic acid, unsaturated polybasic acid, N
- A polyisocyanate compound described below is added to a compound having a polymerizable unsaturated group and active hydrogen such as methylol acrylamide using OH/N CO.

1 based on the molar ratio of C0OH/NC01NH2/NCO
Examples include monomers that do not contain free NGOs and are added at a ratio of 1.2 to 1.2, and one or more selected from these monomers can be used.

In the present invention, the polymerizable unsaturated monomer, particularly a polyfunctional monomer having three or more polymerizable unsaturated groups in one molecule, may be contained in the polymerizable unsaturated monomer in the form of 50 or more. desirable.

In the unsaturated composition of the present invention, it is preferable that the polymerizable unsaturated group-containing resin and the polymerizable unsaturated monomer are mixed to form a transparent state, and the ratio of the linear components can be selected arbitrarily, but based on the total weight of both components, the polymerizable unsaturated group-containing resin is 20 to 80% by weight,
Especially 30-70% by weight, 80-2% of polymerizable unsaturated monomer
A range of 0% by weight, particularly from 70 to 30% by weight, is preferred.

As a polymerization initiator, 2,2'-azobisisobutyronitrile, 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,3,3-
trimethylbutyronitrile), 1.1'-azobis(cyclohexanecarbonitrile), 1.1'-azobis(
cyclooctanecarbonitrile), 2,2'-azobis(2,4-dimethyl4-methoxyvaleronitrile), 2
, 2'-azobis(2,4-dimethyl-4-n-butoxyvaleronitrile), 2,2'-azobis(2-phenyl-propionitrile) and other azo polymerization initiators: benzoyl peroxide, ditertiary butyl peroxide,
Peroxides such as Kumeshi hydroperoxide, 2,4-dichlorobenzoyl peroxide, methyl ethyl butoshi baroxide, cyclohexanone peroxide, etc.
11 is a polymerization initiator: etc.

The blending amount of these polymerization initiators is preferably 0.1 to 20 parts by weight, particularly preferably 0.5 to 8 parts by weight, per 100 parts by weight of the mixture of the polymerizable unsaturated group-containing resin and the polymerizable unsaturated monomer. .

Furthermore, if a peroxide-based polymerization initiator is used as a polymerization initiator, three-dimensional crosslinking of the coating film can be carried out at a higher density. It is preferable to use accelerators such as cobalt octenoate, manganese naphthenate, copper naphthenate, zinc naphthenate, zilfnicum naphthenate, octadecyl isocyanate, benzoin, etc., and the amount of these additives depends on the amount of the above-mentioned polymerizable unsaturated group-containing resin. 0.01 to 4 parts by weight per 100 parts by weight of the mixture of and polymerizable unsaturated monomer,
Particularly preferred is a range of 0.1 to 2 parts by weight.

The unsaturated resin-based paint used in the present invention has the above-mentioned unsaturated composition consisting of a polymerizable unsaturated group-containing resin, a polymerizable unsaturated monomer, and a polymerization initiator as a main component, In addition, necessary organic solvents, water, ultraviolet absorbers, light stabilizers, etc. can be added as appropriate.

Urethane paint: A paint that is applied to the coating surface of the unsaturated WJT resin paint, and contains an active hydrogen-containing resin and a polyisocyanate compound as main components. In this paint, active hydrogen and incyanate groups undergo a crosslinking reaction to form a cured paint film.

First, active hydrogen-containing resin has hydroxyl group (-OH), amine 7
A resin having two or more active hydrogen-containing functional groups such as a group (-NH2) and an imino group (>NH) in one molecule. Specific examples are as follows, but the invention is not limited to these examples only.

(r) A polyester resin made by reacting the already exemplified unsaturated or saturated polybasic acid and polyhydric alcohol as main components to leave hydroxyl groups.

The amount of hydroxyl groups is 30 to 200, especially 50 to 200, based on the hydroxyl value.
A range of 150 is preferred. The polyvarnish 7-' resin is
It also includes those modified with monobasic acids such as benzoic acid, fatty acids, oil components, etc.

(1) IE Kayuoo, □87□ia915:/u-e
:□ Acrylic resin containing one or more types of
:L < ,, ie = /I/ and □. . . A: Regarding vinyl monomers, examples of hydroxyl group-containing vinyl monomers include acrylic acid, which was exemplified above. -Methylol
1□ Methacrylamide, N-hydroxyethylamide
: and N-ato. ,,,,A/I/ 7 p 917
tlz ayodoka (□Which acrylic acid is methacrylic acid? □Di-hydroxyalkyl (C1-12) amides can also be used, and amino group-containing vinyl monomers can be used. Acrylic acid, methacrylamide, amines, etc. can also be used.
：'Imino group-containing vinyl monomers such as
□: N-1-propylacrylamide, t-butylene □No acrylamide, diacetone acrylamide, □N-methylol acrylamide,
N-n-butoxy □Dimethylacrylamide, diallylamine, N-methylolacrylamide butyl ether, methylacrylamide, N-ethyl methacrylamide, etc. are listed, and one or more selected from these can be used.

Acrylic resins or vinyl resins are obtained by copolymerizing vinyl monomers having these functional groups with other vinyl monomers, and their constituent proportions are based on the total amount of both monomers. It is preferable that the vinyl monomer having the above amount is 1 to 50@[1%, particularly 5 to 35% by weight, and the other vinyl monomer is 99 to 50% by weight, particularly 95 to 65% by weight.

As other vinyl monomers, compounds having one or more α,l-ethylenically unsaturated bonds that copolymerize with the vinyl monomer containing the above-mentioned functional groups are used, and specific examples include the following compounds. .

(4) Vinyl aromatic compounds such as styrene, vinyltoluene, α-methylstyrene, or other compounds such as pyronyl acetate, acrylonitrile, methacrylonitrile; (B Methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n -butyl acrylate, n-butyl methacrylate, i-butyl acrylate, i-butyl methacrylate, tert-
Acrylic acids such as butyl acrylate, tert-butyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, lacryl acrylate, lacryl methacrylate, stearyl acrylate, stearyl methacrylate, etc. or an acrylic monomer such as an alkyl or cycloalkyl ester having 1 to 24 carbon atoms of methacrylic acid, (c) N,N-dimethylacrylamide, N,N-
Amide monomers such as diethylmethacrylamide, ■
Glycidyl vinyl ethers such as glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether and methacryl glycidyl ether, glycidyl group-containing vinyl monomers such as glycidyl methyl acrylate and glycidyl methyl methacrylate.

Here, the acrylic resin refers to a copolymer containing the acrylic monomer (1) above at 10]jfi% or more, especially 25% by weight or more, and the content of the acrylic monomer is less than 10711fi% (0 ) is used as a vinyl resin. Furthermore, the number average molecular weight of both of these fatty acids is approximately 1000 to 200,000, particularly 5000 to 1
A range of 00,000 is preferred.

In the present invention, among the specific active hydrogen-containing resins exemplified in (1) and (II) above, (+) acrylic resins containing hydroxyl groups are most preferred, followed by amino groups and shikkeimino resins. Acrylic grains containing groups were suitable.

That is, it is a compound having two or more isocyanate groups in one molecule. Specifically, di- or tri-isocyanate compounds: for example, tetramethylene diisocyanate, hexamethylene diisocyanate, -t, decamethylene diisocyanate, ethylene diincyanate, propylene diisocyanate, inphorone diisocyanate, inphorone diamine diisocyanate, lysine diisocyanate, Aliphatic incyanates such as guimaric acid diisocyanate, xylylene diisocyanate, methiflexylylene diisocyanate, phenylene diisocyanate, tolylene diisocyanate, naphthylene diisocyanate, 4,4'-methylenebis(phenylisocyanate), 414'-ethylenebis(phenyl) isocyanate)), 3.3'-diisocyanate 1.4
Dimethylbenzene, 3,3'-diisocyanate diethyl repensene, 3,3'-diisocyanate dimethyltoluene, 3,3'-diisocyanate dimethylxylene, 3 + 3'-di, incyanate diethyl Aromatic incyanates such as xylene, triphenylmeth〉diisocyanate, diphenylmecundiisocyanate, metaphenylene diisocyanate, diphenylmexitridisocyanate, and 1-methyl-2,4
Diisocyanate cyclohexa/cycloaliphatic incyanate such as 4,4'-methylenebis(cyclohexyl incyanate), ethylene bis(cyclohexylisocyanate), cyclohexane diisocyanate, hexamethylene diisocyanate incyanurate, incyanate adduct: or two or more in one molecule, preferably i
j is an incyanate adduct having 2 to 3 terminal free incyanate groups. Examples of the active hydrogen-containing compound include ethylene glycone propylene glycol, butylene glycol, neopentyl glycol, 29
214-)! J methyl 1.3 pentadiol, hexamethylenediglycol, cyclohexane dimetatool, trimethylolpropane, hexanetriol, chryserisi, penquerythritol sorbitol, sucrose, castor oil, ethylenediamine, monoethanolamine, jetanolamine, trietano -! Examples include raremin, hexamethylene diamine, water, polyether polyol, polyester polyol, polyamide, and hydroxyl group-containing acrylic resin.

The addition reaction between the di- or triisocyanate compound and the active hydrogen-containing compound can be carried out using known methods.

The urethane paint used in the present invention has the above-mentioned active hydrogen-containing resin and polyisocyanate compound as main components, and the ratio of both components can be arbitrarily selected depending on the purpose and is not particularly limited. Preference is given to 10 to 95% by weight of active hydrogen-containing resin, especially 60 to 90% by weight, and 90 to 5% by weight, especially 40 to 10% by weight of polyisocyanate compound, based on the total amount of.

! In addition, in addition to these two components, the urethane paint contains coloring pigments, extender pigments, metallic pigments, dyes,
pearl essence, glass flakes, aggregate, organic solvent,
Ultraviolet absorbers, light stabilizers, etc. can be added.

Painting process: First, the unsaturated resin-based paint can be applied directly to the object to be coated, and then it can be applied as an undercoat or as an intermediate coat to the object to be coated.

The material of the object to be coated is not particularly limited, and examples include various metals, wood, plastics, glass, inorganic materials, and one of these materials.
Examples include combinations of more than one species. These objects to be coated are preferably subjected to degreasing, surface treatment, etc., as necessary, prior to coating.

Lower v! , paints and intermediate coatings that are already known can be used. For example, as the primer coating, cationic or anionic electrodeposition coatings, room temperature drying or heat curing water-based or organic solvent-based primer coatings ( Primer)
Examples of intermediate coatings include polyester resin-based or fatty acid-modified alkyd resin-based paints.

The unsaturated resin paint can be applied to these surfaces by electrostatic coating, air spray coating, airless spray coating, curtain flow coater coating, bar coater coating, dip coating, bald coating, etc. Therefore, it is desirable to adjust the viscosity of the paint to a range that is compatible with these coating methods.

The thickness of the coating film of unsaturated/Japanese resin paint can be selected arbitrarily depending on the purpose, but it is approximately □5～
100μ, especially preferably in the range of 10 to 40μ.If the unsaturated resin paint contains a polymerization initiator, crosslinking may occur even at room temperature. It is preferable to apply the paint as soon as possible after preparing it.

Next, it is important to apply urethane paints because the activity of the polymerizable unsaturated groups present on the coating surface of the unsaturated resin paints is inhibited by oxygen in the air. be. Specifically, within 2 hours after applying the unsaturated resin paint,
It is preferable to apply the flexure paint within minutes, especially within 5 minutes (based on 20℃).
If Cretashi-based paint is applied after this time has elapsed, curing may be inhibited on the surface of the unsaturated resin-based paint, resulting in poor interlayer adhesion between the surface coatings. I don't like it because there is.

The urethane-based paint can be applied in the same manner as the unsaturated resin-based paint, and the coating film thickness is 5 to 50%, including the cured film.
10011I Particularly preferably 10 to 50 seconds 0 Both of the above vocal membranes will be cross-linked and cured three-dimensionally even if left at room temperature, but it goes without saying that the curing time can be shortened by heating to 60 to 120°C, for example, compared to room temperature. Since cross-linking and curing can be carried out sufficiently, coating film performance such as hardness, solvent resistance, water resistance, moisture resistance, impact resistance, etc. can be significantly improved.

In addition, in the method of the present invention, if the polymerizable unsaturation-containing resin in the unsaturated resin paint has an active hydrogen-containing functional group such as a hydroxyl group, an amino group, or an imino group, the coating surface of the paint can be coated. A part of the polyisocyanate contained in the urethane paint penetrates into the unsaturated resin paint film, reacts with the above functional groups, and impairs the physical and chemical performance of the paint film itself. Furthermore, the adhesion to the 1-cretane paint film is also improved.

Below, the content of the present invention will be further explained in detail with reference to Examples and Comparative Examples.

1. Production of polymerizable unsaturated group-containing resin ■ = acrylic acid is added to a copolymer (molecular weight s, o o o) consisting of 2-, droxyethyl methacrylate, butyl acrylate, and glycidyl methacrylate to obtain an unsaturated equivalent of 830 , an unsaturated acrylic resin varnish (60% xylene solution) with a hydroxyl value of 9° is carefully selected.

■: Copolymer consisting of 2-upper 2-xyethyl methacrylate, butyl acrylate-turglycidyl acrylate (
(molecular weight 10,000) was added with methacrylic acid to obtain an unsaturated acrylic resin varnish (50% xylem solution) with an unsaturated equivalent of 830 and a hydroxyl value of 9o.

■: To a copolymer (molecular weight 5000) of 2-, droxyethyl acrylate, and methyl methacrylate, equimolar reactants of inphorone diisocyanate and hydroxyethyl acrylate are added per mole of hydroxyl groups in the copolymer. An unsaturated acrylic resin varnish (50% xylene solution) with an unsaturated equivalent of 500 and a hydroxyl value of 40 added at a ratio of 0.6 mol was prepared.

■: Acrylic acid is condensed to a copolymer of 2-, droxyethyl methacrylate, and butyl acrylate (molecular weight 5ooo) using balatoluenesulfonic acid as a catalyst,
An unsaturated acrylic resin varnish (50% xylene solution) having an unsaturated equivalent of 1000 and a hydroxyl value of 60 was obtained.

2. Production of active hydrogen-containing resin (A): Copolymerization of n-butyl acrylate, 2-hydroxyethyl methacrylate, 2-ethylhexyl methacrylate, and acrylic acid using azobisisobutyronitrile as a reaction catalyst. Number average molecular weight 10,000
, acrylic polyol Im with a hydroxyl value of 120 and an acid value of 23
WiI varnish (50% xylene solution) was obtained.

3. Manufacture of unsaturated resin paint Paint ■ (% by weight) Unsaturated acrylic resin varnish ■ 75 Trimethylolpropane triacrylate 15 Azobisisovaleronitrile 2 Aluminum powder
8 Paint ■ Unsaturated acrylic resin varnish ■ 7゜ Dipecyrythritol hexaacrylate 15 Methyl methacrylate 5 Azobisisovaleronitrile 2 Aluminum powder
8 (+#1830YL Toyo Aluminum ■) Paint ■ Unsaturated acrylic resin varnish ■ 75 Dipentaerythritol hexaacrylate 15 Azobisisovaleronitrile 2 Aluminum powder
8 Paint ■ Unsaturated acrylic resin varnish ■ 75 dipentaerythritol hexaacrylate 15 azobisisovaleronitrile 2 aluminum powder
8 Paint ■ Unsaturated acrylic resin varnish ■ 75 Trimethylolpropane trimethacrylate 15 Azobisisovaleronitrile 2 Aluminum powder
84. Manufacture of urethane paint Manufacture of paint Acrylic polyol tri solution ■ 65 Adduct of 3 moles of hexamethylene diisocyanate and 1 mole of trimethylol propane 25 Kizirol 10 Manufacture of paint ■ Acrylic polyol resin ■ 63 Hexamethylene Diisocyanate incyanurate 27 (Dismodur N-3390゜Order Bayer ■) Kijiroru 105, Examples and Comparative Examples PosiPride Donna 3030 (manufactured by Nippon Parker Lysin ■,
Elecrona 92 is applied to a steel plate chemically treated with zinc phosphate (zinc phosphate).
00 (manufactured by Kansai Paint ■, epoxy polyamide-based cationic electrodeposition paint) was applied by a conventional method, and heated at 170°C for 30°C.
Separate baking is done next (film thickness 20μ), and then Amirac N-2
Apply sealer (manufactured by Kansai Paint ■, amino polyester resin intermediate coating paint) (film thickness 25μ), 3 at 140℃.
The unsaturated resin-based paint and urethane-based paint obtained in the above production example as shown in Table 1 were applied to the coated plate baked for 0 minutes in the next step.

In Table 1, the film thicknesses are all based on the cured coating film, and the setting conditions are the temperature and time until the next step. After painting both songs, heat them to harden both songs. In Comparative Example 6, “■” in the unsaturated resin paint column
" is Magiklon TB-300 Silver Meclic (manufactured by Kansai Basito ■, Silver Nuclic thermosetting acrylic resin paint), and the "C" in Cretashi-based paint is!
DIKROSHI TC50 CLEAR - (manufactured by Kansai Paint ■, thermosetting acrylic resin clear paint).

6. Results of coating film performance tests Various coating film performance tests were conducted using the coated plates obtained in the above Examples and Comparative Examples. The results are shown in Table 2. The performance test method is as follows.

& Gel fraction: Composite coating film/It amount of remaining coating film after 6-hour immersion in circulating acetone solution Glossiness 2 60° specular reflectance (JIS K 540
0) Impact resistance: JIS K 5400-1979 6
．． 13. According to the 3B method, a weight of 500 f is dropped onto the painted surface at 20°C, and the maximum drop lIi# (3) that does not cause cracking or peeling on the painted surface is determined.

Adhesiveness: Make 100 pieces of 1 x 1 inch squares with a knife so that they reach the base, stick adhesive cellophane tape on the surface, then peel off rapidly. I looked into it.

Hardness: Pencil hardness (20°C) Alkali resistance: Keep the test piece at room temperature and examine the 7'jl/ION coating for cracks, blistering, peeling, gloss, and color changes.

◎There is no change in the condition of the painted surface compared to before dipping. do not have Slight shine, blurring, and color changes are observed. Ru ×Remarkable changes observed Cracks, blisters, and peeling of the paint film after removal Check for changes in texture, gloss, and color.

The Y1 constant standard is the same as the alkali resistance test.

Paint film such as peeling, blistering, wrinkles, peeling etc. Check for abnormalities.

Judgment criteria are the same as the alkali resistance test.

Claims (1)

[Claims] An unsaturated resin paint whose main component is a composition consisting of a polymerizable unsaturated group-containing resin, a polymerizable unsaturated vinyl monomer, and a polymerization initiator is applied, and then an active hydrogen-containing resin and a polyisocyanate compound are applied to the painted surface. A method for forming a composite coating film by applying a urethane-based paint containing as the main components and curing both coatings at room temperature or by heating.