JPH01297177A - Method for metallic coat finishing - Google Patents

Abstract

PURPOSE:To improve flatness, brightness, massive feeling, etc., of a metallic coat surface by applying a clear lacquer composed of a thermosetting resin compound to a surface coated with a metallic paint and by further applying a clear lacquer composed of a radically polymerized compound thereto. CONSTITUTION:After a metallic paint mainly composed of a metallic pigment and a thermosetting resin compound is applied to a surface, a clear lacquer mainly composed of a thermosetting resin compound is applied onto the coated surface. A clear lacquer mainly composed of a nonaqueous dispersion liquid, which is obtained by polymerizing a radically polymerizable monomer under the presence of a dispersant composed of fluoroolefin polymer of 5000-120000 in wt.av. MW and containing 1-60wt.% fluorine in a specified organic solvent, is further applied onto the coated surface. Then, a metallic coat finishing is carried out by heat-treating and curing these three coating film simultaneously.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a novel metallic finish coating method, and more particularly to a coating method for finishing a metallic coating film with excellent smoothness, sharpness, texture and weather resistance.

Conventional technology and its problems Conventionally, as a method of painting automobile exterior panels, etc., a metallic paint is applied, a clear paint is applied to the uncured painted surface, and then both coatings are heated and cured at the same time. A metallic finishing method using the two-coat-one-beta method (2CIB) is often adopted.

As the automobile industry and other industries increasingly seek luxury products, there is a strong demand for the development of coating methods that can finish automobile exterior panels with metallic coatings that have excellent weather resistance, smoothness, sharpness, and texture. . In order to achieve these demands, we have developed clear paints to replace conventional thermosetting acrylic resin or polyester resin paints.
Attempts have been made to use organic solution paints containing fluorine-containing resin as a main component, and improvements in weather resistance have been recognized as a result. However, when a fluorine-containing resin is used as a clear paint, it has been pointed out that the cost is extremely high and the improvement in texture is insufficient.

Means for Solving the Problems The present inventors have conducted intensive research on the effective use of fluorine-containing resins in metallic finishing.

As a result, in addition to the uncured clear coating surface of 2CIB, which uses a thermosetting resin coating as a clear coating, we added a clear coating whose main component is a non-aqueous dispersion containing a fluorine-containing polymer as a dispersion stabilizer. By painting and then heating (baking) to simultaneously cure the three-layer coating film, smoothness, sharpness, and sharpness are improved compared to when a clear coating film is formed using only fluorine-containing polymer paint. It has been found that it is possible to significantly improve the feeling of feeling, etc., and there is almost no decrease in weather resistance or increase in cost.

That is, the present invention provides the following steps: i) coating a metallic paint containing a metallic pigment and a thermosetting resin composition as main components, and ii) then applying a clear coating containing a thermosetting resin composition as a main component to the coated surface. iii) In the presence of a dispersant consisting of an organic solvent-soluble fluoroolefin polymer having a weight average molecular weight of about 5,000 to 120,000 and a fluorine atom content of about 1 to 60% by weight, a radically polymerizable monomer is A clear material whose main component is a non-aqueous dispersion obtained by polymerizing the radically polymerizable monomer in an organic solvent in which the polymer formed by the radically polymerizable monomer is soluble in the organic solvent and in which the polymer formed by the radically polymerizable monomer is insoluble. The present invention relates to a metallic finishing method characterized in that, after applying a paint to the above-mentioned clear coated surface, iv) heating is performed to simultaneously cure the above-mentioned three-layer coating film.

A feature of the present invention is that a clear paint (hereinafter sometimes abbreviated as "S-clear paint") whose main component is a conventionally used thermosetting resin composition is applied to the uncured metallic coating film-E. and a coating film made of a clear paint (hereinafter sometimes abbreviated as rFNAD-clear paint) whose main component is a non-aqueous dispersion containing a specific fluorine-containing polymer as a dispersion stabilizer. The purpose is to form and cure these three layer coatings at the same time. According to the method of the present invention, a coating film made of FNAD-clear paint can be formed only on the surface layer portion of the clear coating film (the total film thickness of S-clear coating film and FNAD-clear coating film is Even if the film thickness is comparable to that of a single-layer clear coating film, the desired purpose can be sufficiently achieved.

As a result, the technical effects described below are obtained.

(1) Feeling of texture: This is a visual experience of the three-dimensional thickness of the coating film, and when this "feel of texture" is excellent, it adds a luxurious feel to the coated object. For this reason, "texture" is an important function in terms of finished appearance for automotive top coat paints. In the past, the ``citrus skin'' on the surface of the paint film created three-dimensional unevenness, which gave a sense of thickness and gave the impression of ``fleshiness''. However, recently, there has been a growing demand for further improvements in the finished appearance of automobile paints, and in particular, there has been an increasing demand for "smoothness" and "sharpness" of the paint film surface. Therefore, the above-mentioned ``Yuzu skin'' that creates a ``fleshly feeling'' and these ``smoothness'' and ``sharpness'' are fundamentally contradictory, and ``smoothness'' and ``sharpness'' There was a need to improve the ``feeling of fleshiness'' without causing ``yuzu skin.'' At this point, the inventors have discovered that FNA
It has been found that D-clear paint is suitable for providing this "fleshly feeling". In other words, by applying FNAD-clear paint over the uncured surface of a clear paint (S-clear paint) whose main component is a thermosetting resin composition, the difference in the refractive index of both clear paint films allows It has been found that the presence of the clear coating film can be subtly detected visually, giving a three-dimensional effect, that is, a feeling of fleshiness. This effect can never be achieved with either clear coating alone. The refractive index of the cured S-clear paint film conventionally used in 2CIB is approximately 1.50 to 1.50. 55 (20°
C), and on the other hand, the refractive index of the cured film of FNAD-clear paint is 1.45 to 1.48 (20°C). This discrepancy in refractive index is thought to be what gives the two-layer clear coat its "textured feel."

(2) Smoothness and sharpness: Conventionally, in the case of a single coat of S-clear paint, in order to maintain the weather resistance of the cured film for a long period of time, the amount of curing agent blended was adjusted to the stoichiometric ratio with the base resin. The method is to increase the number of crosslinking points between curing agents by increasing the quantitative ratio. For this reason, the thermal fluidity of the coating film was poor, and there was a limit to the improvement of image clarity and smoothness. However, according to the method of the present invention, the weather resistance of the fluorine-containing resin itself in the FNAD-clear paint is overwhelmingly better than that of the S-clear paint, so the blending ratio of the curing agent in the S-clear paint is can be lowered. As a result, the heat curing properties of the S-clear paint become gentler, the heat fluidity during heating improves, and the coated surface becomes smooth (=
Improves the smoothness and sharpness of the finished painted surface. Also, F
By repeatedly applying NAD-clear paint, weather resistance can also be significantly improved. FNAD
- Even if the amount of curing agent added to a clear paint is small, there is almost no reduction in weather resistance.

(3) Weather resistance: By forming an FNAD-clear coating film on the surface layer portion of the clear coating film, weather resistance is improved compared to a single coating film of S-clear paint.

This weather resistance is approximately the same as that of a clear coating film formed using only FNAD-clear paint.

(4) Since the film thickness of the FNAD-clear coating film may be thin, the cost is lower than forming the clear coating film from the FNAD-clear paint alone, and weather resistance etc. are not deteriorated.

(5) Since both of the above clear paints are applied wet-on-wet, ■The finished appearance does not deteriorate even if the FNAD-clear paint is applied in a thin film.■The interlayer adhesion of both rear paints is excellent. There are effects such as

Next, the method of the present invention will be explained in more detail.

Metallic paint> This is a paint that contains a metallic pigment and a thermosetting resin composition as main components, and contains a coloring pigment if necessary, and any known paint can be used.

There is no need to blend a fluorine-containing polymer.

Examples of metallic pigments include aluminum powder, copper powder, mica powder, mica-like powder coated with titanium oxide, and MIO (mica-like iron oxide).As coloring pigments, ordinary inorganic or organic pigments for paints can be used. .

A thermosetting resin composition is a composition that is three-dimensionally crosslinked and cured by heating, and is composed of a base resin and a crosslinking agent. Examples of the base resin include acrylic resin, alkyd resin,
Examples include paints whose main component is one or a mixture of two or more of urethane resins, polyester resins, and epoxy resins.

However, when using epoxy resin, it is used as a mixed system with other resins. Further, in addition to these resins, resins that do not undergo curing and crosslinking reactions, such as cellulose acetate butyrate resins, may also be used. Preferred crosslinking agents include alkyl etherified melamine resins, polyisocyanate compounds, and blocked isocyanate compounds.

The amount of the metallic pigment to be used may be appropriately determined depending on the type thereof, but generally it may be about 1 to 30 parts by weight based on 100 parts by weight of the resin composition.

Coloring pigments can be blended as necessary, and their usage depends on the coloring power of the pigment, but generally the resin composition 10
It can be blended in an amount of about 1 to 100 parts by weight per 0 parts by weight.

The blending amount of the crosslinking agent is appropriately determined depending on the type of resin and crosslinking agent used, and is usually 100% of the base resin.
It is appropriate to add about 15 to 70 parts by weight.

Types of metallic paints using these ingredients include solution-type paints using organic solvents as a medium, non-aqueous dispersion paints, multi-component paints, powder paints, and powder slurry paints in which powder is dispersed in water. or any type of water-based paint dissolved or dispersed in water.

S-Clear paint> A paint that forms a transparent film that is applied to the uncured surface of the metallic paint.The main components are a base resin and a crosslinking agent, and when heated, both components undergo a three-dimensional crosslinking reaction. and harden. A fluorine-containing resin is not particularly required. The types and amounts of the base resin and crosslinking agent, as well as the type of paint, may be appropriately selected from those similar to those exemplified for the metallic paint.

Furthermore, a colored pigment can be added to this S-clear paint to the extent that it does not inhibit the metallic appearance of the metallic coating film.

According to the method of the present invention, the amount of crosslinking agent in the S-clear paint can be lower than usual, and although the amount of crosslinking agent varies depending on the type of base resin and the number of functional groups, etc., it is difficult to standardize it1. For example, in the melamine resin,
About 10 to 30 parts by weight per 100 parts by weight of the base resin,
For polyisocyanate compounds (including blocked compounds), there is almost no risk of deterioration in weather resistance, etc., even when the blending amount is about 0.8 to 0.9 mol of isocyanate groups per 1 mol of crosslinked functional groups in the base resin. .

As a result, the softening-fluidization-hardening reaction of the coating film during the heat curing process is gradual and volumetric shrinkage is small (as a result, the smoothness and sharpness of the coating surface can be improved compared to those containing a large amount of crosslinking agent).

<FNAD-Clear Paint> This is a transparent coating film-forming paint that is applied to the uncured surface of the above-mentioned S-clear paint, and is a non-aqueous dispersion type clear paint that uses a fluorine-containing polymer as a dispersion stabilizer.

Specifically, the fluorine-containing polymer used as a dispersion stabilizer contains a fluoroolefin as a constituent component, has a weight average molecular weight of about 5,000 to about 120,000 (number average molecular weight of 1,000 to 60,000), and contains a fluorine atom. Amount 1
-60% by weight of a polymer soluble in organic solvents at room temperature. The fluorine polymer is selected from a single polymer of fluoroolefins, a vinyl ether compound such as an alkyl vinyl ether, an alicyclic vinyl ether, a hydroxy vinyl ether, a glycidyl group-containing vinyl ether, and an olefin compound such as an olefin or a halo-olefin. It is a copolymer of fluoroolefins containing at least one unsaturated monomer (hereinafter referred to as "unsaturated monomer (A)") as a copolymerization component.

The amount of unsaturated monomer (A) used may be such that the amount of fluorine atoms in the copolymer is in the range of 1 to 60% by weight.

Examples of the fluoroolefins include fluoroolefins having 1 to 6 fluorine atoms and 2 to 3 carbon atoms, such as tetrafluoroethylene, tarolotrifluoroethylene, vinyl fluoride, and vinylidene fluoride.

Further, a carboxyl group-containing fluoroolefin can also be used.

In addition, examples of alkyl vinyl ethers that are other copolymerization components include ethyl vinyl ether, isobutyl vinyl ether, n-butyl vinyl ether, etc.; examples of alicyclic vinyl ether include cyclohexyl vinyl ether and its derivatives; examples of hydroxy vinyl ether include hydroxybutyl vinyl ether; As glycidyl group-containing vinyl ethers,
Examples include the above-mentioned vinyl ethers having a glycidyl group. Examples of olefins and haloolefins include ethylene, propylene, isobutylene, vinyl chloride, and vinylidene chloride.

These other copolymerization components, unsaturated monomers (A), are:
Each can be used alone or in combination of two or more. Furthermore, the above-mentioned unsaturated monomer (A)
A part of unsaturated carboxylic acid, ester of unsaturated carboxylic acid, carboxylic acid vinyl ester, vinyl aromatic compound,
Other unsaturated monomers (hereinafter referred to as "unsaturated monomer (B)") such as (meth)acrylonitrile may be substituted.

These unsaturated monomers (B) can be used up to about 20% by weight, preferably about 10% by weight of the total amount of unsaturated monomers (A) and (B).

Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, crotonic acid, maleic acid, and maleic anhydride. Examples of unsaturated carboxylic acid esters include methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, hexyl acrylate, octyl acrylate, lauryl acrylate, methyl methacrylate, ethyl methacrylate, and methacrylate. butyl methacrylate, isopropyl methacrylate, butyl methacrylate, hexyl methacrylate, octyl methacrylate,
C5-C18 alkyl ester of acrylic acid or methacrylic acid such as lauryl methacrylate; 02-CB of acrylic acid or methacrylic acid such as hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate
Examples include hydroxyalkyl ester, N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, and the like. Furthermore, examples of carboxylic acid vinyl esters include vinyl acetate, vinyl n-butyrate, and the like. Examples of vinyl aromatic compounds include styrene, α-methylstyrene, and vinyltoluene.

The fluorine atom content in the fluorine-containing polymer is approximately 1
-60% by weight, preferably about 10-40% by weight. If the fluorine atom content is less than 1%, the characteristics of the fluorine-containing polymer will not be fully exhibited, and if it exceeds 60%, the solubility in organic solvents will decrease.

Furthermore, a polymerizable double bond may be introduced into such a fluorine-containing polymer to achieve grafting with the dispersed particle window portion. In order to introduce this polymerizable double bond, for example, a carboxylic acid group-containing monomer is used as a copolymerization component of a self-fluorinated copolymer, and a glycidyl group-containing unsaturated monomer (for example, glycidyl methacrylate, glycidyl acrylate, allyl glycidyl ether, etc.), but of course it can also be done conversely by reacting a glycidyl group-containing acrylic copolymer with a carboxyl group-containing unsaturated monomer.

Other such combinations include acid anhydride groups and hydroxyl groups, acid anhydride groups and mercapto groups, isocyanate groups and hydroxyl groups, and the like. The general conditions under which addition reactions occur between such combinations of reactive groups are well known, and the temperatures at which these reactions occur depend on the particular combination of reactive groups chosen and can be controlled by the use of catalysts. Needless to say, it can be changed.

Of course, in the present invention, it is not necessary for the dispersion stabilizer resin to have a polymerizable double bond, but by introducing a polymerizable double bond, a covalent bond is formed between the polymer forming the particles and the dispersion stabilizer, Further improvements in storage stability and mechanical stability of the dispersion can be achieved. The polymerizable double bond is preferably present in an average of about 0.1 to 2 moles per mole of the dispersion stabilizer resin.

As a specific example of the above-mentioned fluorine-containing polymer, for example, hydroxyl group-containing organic solvent-soluble "Lumiflon" series (for example, "Lumiflon LF200J (weight average molecular weight approximately 50
000, hydroxyl value 50, fluorine atom content U approximately 30wt%
,) "Lumiflon LF400" (weight average molecular weight 50
000, hydroxyl value 50, acid value 5, fluorine atom content 3
0wt%) "Lumif, Ron LF-4006J, (weight average molecular weight 25000, hydroxyl value 100, acid value 10, fluorine atom content 30wt%) all manufactured by Asahi Glass ■),"
Sephural Coat” (trademark: manufactured by Central Glass), r
Kynar SLJ rKynar ADSJ
(trademark: manufactured by Pennwalt Co.), etc.

The molecular weight of the fluorine-containing polymer is a weight average molecular weight of about 500.
0 to about 120,000 (number average molecular weight of about 1,000 to 6
0,000), preferably about 10,000 to 60,000.

If the average molecular weight is less than about 5,000, the stabilization of the dispersed particles is insufficient, and aggregation and sedimentation are likely to occur. On the other hand, if the molecular weight exceeds 120,000, the solubility of the fluorinated polymer in organic solvents decreases. This causes a decrease in the viscosity of the dispersion and a significant increase in the viscosity of the dispersion.

The production of the fluorine-containing polymer is usually carried out using a radical polymerization initiator. Examples of usable radical polymerization initiators include azo initiators such as 2,2'-azobisisobutyronitrile and 2,2'-azobis(2°4-dimethylvaleronitrile), benzoyl peroxide, and lauryl. Examples include peroxide-based initiators such as peroxide and tert-butyl peroctoate, and these polymerization initiators are generally used in an amount of 0.2 to 10 parts by weight, preferably 0.2 to 10 parts by weight, per 100 parts by weight of monomers to be subjected to polymerization. It can be used within the range of 0.5 to 5 weight. Generally, emulsion polymerization in an aqueous medium and solution polymerization in an organic solvent are employed as the reaction format. Various solvents can be used as the solvent,
In addition to aromatic hydrocarbons, alcohols, esters, ketones, gelcol ethers, etc., various commercially available thinners can also be used. These may be used alone or in combination of two or more in various proportions. The reaction temperature and reaction pressure are appropriately selected depending on the type of polymerization initiator, the type of solvent, and the reaction format.

The FNAD-clear paint is obtained by polymerizing at least one radically polymerizable monomer in an organic solvent solution using the above-mentioned fluorine-containing polymer as a dispersion stabilizer.

As the dispersion stabilizer, the above-mentioned fluorine-containing polymer may be used alone, or two copolymer compositions and molecular weights of different copolymer compositions may be used.
You may use it in combination of more than one kind.

In addition, if necessary, other dispersion stabilizers such as butyl etherified melamine-formaldehyde resin, alkyd resin, general acrylic resin, etc. may be added to 60% of the total amount of dispersion stabilizer.
They may be mixed up to about % by weight or less.

The organic solvent used in the polymerization does not substantially dissolve the dispersed polymer particles produced by the polymerization, but does not dissolve the dispersion stabilizer resin (fluorine-containing resin) and the radically polymerizable monomer. Includes organic liquids that serve as good solvents.

Specific examples of such organic liquids include aliphatic hydrocarbons such as hexane, heptane, and octane; benzene, toluene,
Aromatic hydrocarbons such as xylene; alcohol threads, ether-based, ester-based and carbon-based solvents such as isopropyl alcohol, n-butyl alcohol, i-butyl alcohol, octyl alcohol, cellosolve, butyl cellosolve, diethylene glycol monobutyl ether, methyl Examples include isobutyl ketone, diisobutyl ketone, ethyl acyl ketone, methylhexyl ketone, ethyl butyl ketone, ethyl acetate, isobutyl acetate, acyl acetate, 2-ethylhexylacetate-1, etc., and each of these may be used alone. Although it is possible to use a mixture of two or more types, in general, aliphatic hydrocarbons are the main component,
In addition, aromatic hydrocarbons and alcohols such as those mentioned above,
A combination of ether, ester or ketone solvents is preferably used. Furthermore, trichlorotrifluoroethane, meta-xylene hexafluoride, tetrachlorohexafluorobutane, etc. can also be used if necessary.

The monomers polymerized in the presence of the above-mentioned dispersion stabilizer and organic liquid are not particularly limited as long as they are radically polymerizable unsaturated monomers, and various monomers can be used. Typical examples are as follows.

(a) Esters of acrylic acid or methacrylic acid: for example, methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate,
Hexyl acrylate, octyl acrylate, lauryl acrylate, methyl methacrylate, ethyl methacrylate,
01-C1B alkyl esters of acrylic acid or methacrylic acid such as propyl methacrylate, isopropyl methacrylate, butyl methacrylate, hexyl methacrylate, octyl methacrylate, lauryl methacrylate; glycidyl acrylate, glycidyl methacrylate; allyl acrylate, allyl methacrylate, etc. C2-C8 alkenyl ester of acrylic acid or methacrylic acid;
02-C8 hydroxyalkyl esters of acrylic acid or methacrylic acid such as hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate; 03-CI of acrylic acid or methacrylic acid such as allyloxyethyl acrylate, allyloxymethacrylate
8 alkenyloxyalkyl ester.

(b) Vinyl aromatic compounds: for example, styrene, α-methylstyrene, vinyltoluene, p-chlorostyrene vinylpyridine.

(C) α,β-ethylenically unsaturated acids: eg acrylic acid, methacrylic acid, itaconic acid.

(d) Others: acrylonitrile, methacrylonitrile, methyl isopropenyl ketone; vinyl acetate, beoba monomer (Shell Chemicals), vinyl propionate, vinyl pivalate, etc.

Particularly preferred among these monomers are monomers or monomer mixtures containing at least 40% by weight of esters of acrylic acid or methacrylic acid.

Polymerization of the above monomers is carried out using a radical polymerization initiator. Examples of usable radical polymerization initiators include azo initiators such as 2,2'-azoisobutyronitrile and 2,2'-azobis(2,4-dimethylvaleronitrile), benzoyl peroxide, and lauryl. Examples include peroxide-based initiators such as peroxide and tert-butyl peroctoate, and these polymerization initiators are generally used in an amount of 0.2 to 1 per 100 parts by weight of the monomer to be subjected to polymerization.
It can be used in an amount of 0 parts by weight, preferably in a range of 0.5 to 5 parts by weight.

Further, the amount of the dispersion stabilizer used can vary widely depending on its type, etc., but in general, it is 5 to 80% by weight based on the total amount of the monomer to be polymerized and the dispersion stabilizer.
Preferably within the range of about 10 to about 60% by weight is advantageous.

Furthermore, the total concentration of the radically polymerizable monomer and dispersion stabilizer in the organic solvent solution is generally 30 to 70% by weight.
degree, preferably about 30 to 60% by weight.

Polymerization can be carried out by a method known per se, and the reaction temperature during polymerization can generally be in the range of about 60 to about 160°C, and the reaction usually takes about 1 to about 15 hours to complete. can be set.

The non-aqueous dispersion produced by the method described above has extremely excellent dispersion stability.

In the present invention, in the non-aqueous dispersion obtained by the above method,
A dispersion stabilizer and a curing agent for crosslinking and curing the dispersed particles are blended, and this is used as an FNAD-clear paint.

The non-aqueous dispersion may be used alone or in combination of two or more of different copolymer compositions and molecular nails. Furthermore, if necessary, other top coat coating resins, such as alkyd resins and acrylic resins, may be added to the non-aqueous dispersion with a solid content of 10%.
It may be added up to about 50 parts by weight relative to 0 parts by weight.

As the curing agent, common curing agents such as methylolated and/or alkyl etherified melamine resins, polyisocyanate compounds, blocked polyisocyanate compounds, amino resins, epoxy resins, etc. are used. The composition of the curing agent (2) is normally selected appropriately within the range of 5 to 50% by weight of the total amount of the dispersion stabilizer, dispersed particles, and curing agent, but according to the coating method of the present inventor, FNAD- Even when the amount of curing agent in the clear paint is as small as 5 to 25% by weight, there is almost no decrease in weather resistance.

Furthermore, a colorant, a plasticizer, etc. can be added to the FNAD-clear paint, if necessary.

Colorants include dyes, organic pigments, inorganic pigments, etc. Plasticizers include known ones, such as low molecular weight plasticizers such as dimethyl phthalate and dioctyl phthalate, vinyl polymer plasticizers, and polyester plasticizers. Examples include polymeric plasticizers, and these can be used by being mixed into the non-aqueous dispersion, or they can be dissolved in, for example, radically polymerizable monomers during the production of the non-aqueous dispersion, and the resulting dispersion can be It can also be distributed in liquid dispersed polymer particles.

In the present invention, weather resistance can be further improved by incorporating an ultraviolet absorber and a light stabilizer into the metallic paint and/or the clear paint. The ultraviolet absorber absorbs ultraviolet energy, is compatible with each paint resin, or can be uniformly dispersed, and does not easily decompose and lose its effectiveness when baked into the paint film. For example, benzophenone type, benzotriazole type, phenyl salicylate type, diphenyl acrylate type and others such as hydroxy-5-methoxy-acetophenone, 2-hydroxy-naphthophenone, 2-ethoxyethyl-para- Methoxycinnamate, nickel-bisoctylphenyl sulfide, [2,2'-thiobis(4-t-octylphenolado)]-n-butylamine-nickel, ethanediamide/N-(2-ethoxyphenyl)-N'-( 4
-isododecylphenyl), among which only one type may be blended into the metallic paint or both the metallic paint and the clear paint, or two or more types may be blended simultaneously.

In addition, by using light stabilizers together with ultraviolet absorbers,
The weather resistance of the metallic paint film and the clear paint film can be further improved, and specifically, the weather resistance of the metallic paint film and the clear paint film can be further improved. Any type of baking may be used as long as it is easily decomposed by temperature and does not lose its effectiveness. Specific examples of light stabilizers include bis(2,2,6,6
-tetramethyl-4-piperidyl) sebacate, bis(
1,2,2,6,6-bentamethyl-4-piperidyl)
Sebacate, 2-(3,5-ditertiary-butyl-
4-hydroxybenzyl)-2-n-butylmalonate bis(1,2,2,6-bentamethyl-4-piperidyl),
Tetrakis (2゜2.6.6-tetramethyl-4-piperidyl)-1+ 2.3.4-butanetetracarboxylate, Tetrakis (1,2,2,6,6-bentamethyl-4-piperidyl)-1, Examples include 2,3,4-butanetetracarboxylate, among which only one type may be used in combination with the ultraviolet absorber, or two or more types may be used in combination.

Ultraviolet absorbers and light stabilizers are effective even when used alone, but when they are used together, they have a synergistic effect and exert greater power to improve weather resistance.
One or more types of light stabilizers are used in combination.

The amount of ultraviolet absorber and light stabilizer to be blended is 0.00% relative to the resin solid content of the metallic paint or clear paint.
The coloring may be about 5 to 5% by weight, preferably 1 to 2% by weight.

Coating Method> The metallic finishing method in the present invention is carried out using the above-mentioned metallic paint and both clear paints. That is, first, adjust the viscosity of the metallic paint to about 10 to 30 seconds (Ford Cup #4/20°C), and apply it directly to the material (steel plate, aluminum plate, plastic plate, etc.) or with a primer (for example, cation type or The substrate is coated with anionic electrodeposition paint (anionic electrodeposition paint) and further with an intermediate paint so that the cured film thickness is about 10 to 30 μm.

The coating is performed, for example, by spray coating, electrostatic coating, etc. Next, after leaving it for several minutes, without curing the metallic coating,
Reduce the viscosity for about 20 to 40 seconds (Ford Cup #4/20°
C): Apply the A-conditioned S-clear paint by spray painting, electrostatic painting, etc. so that the cured film thickness is about 20 to 30 μm.

Subsequently, after leaving it for several minutes, apply a viscosity of about 20 to 40 seconds (Ford Cup #4/20) to the uncured S-clear coating surface.
FNAD-clear paint adjusted to 15°C) is applied by spray painting, electrostatic painting, etc. so that the cured film has a thickness of about 15 to 20 μm.

Next, it is left at room temperature for several minutes and then heated at about 80° C. to 1609° C. for about 10 to 30 minutes to simultaneously cure the metallic coating film and both clear coating films, thereby obtaining the metallic finish that is the object of the present invention.

Effects of the Invention According to the method of the present invention, a metallic coating film that is excellent in weather resistance, smoothness, sharpness, texture, etc. can be obtained at a relatively low cost.

Examples Next, examples and comparative examples related to the present invention will be described. Note that parts and percentages are, in principle, based on weight.

Production example 1, production example of metallic paint (M-1): 15% styrene, 15% methyl methacrylate, 40% butyl methacrylate, 13% 2-ethylhexyl acrylate, 1.15% hydroxyethyl methacrylate, and acrylic acid. 2% was copolymerized in Kizilol using a polymerization initiator azobisisobutyronitrile, heating residue 50%, solution acid value 80, solution viscosity Y (Gardner, 2
(5°C) (7) 7 Grill resin solution AC-1 was obtained.

A solution-type metallic paint (M-1) containing this acrylic resin solution AC-1 was created.

50% AC-1160 parts 60% melamine formaldehyde resin (Note 1) 40 parts Aluminum paste-A (Note 2) 12 parts Organic yellow pigment (Note 3) 0.01 part Carbon black (
Note 4) 0.0005 parts 10% ultraviolet absorber solution (Note 5) 10 parts 222.015 parts (Note 1) Product name manufactured by Mitsui Toatsu Chemical ■ Trade name Kneepan 208E-60 (n-butanol modified melamine resin solution) (Note 2) Product name Aluminum Paste 4919H manufactured by Toyo Aluminum ■ (Note 3) Product name Irgajinero-3RLTN manufactured by Ciba Geigy Co., Ltd. (Note 4) Product name Neo 5pectra Beads A manufactured by Columbia Carbon ■
G (Note 5) Manufactured by Ciba Geigy ■Product name Tinuvin 90010
1 part was added to 90 parts of doluol and dissolved.

Next, apply this metallic paint (M-1) to Dorall 4.
0 parts, Swasol #1000 (manufactured by Cosmo Oil ■, trade name) 30 parts, butyl acetate 20 parts, and n-butanol 10 parts with a viscosity of 14 seconds (Ford Cup #4/
20°C).

(M-2): Using 210 parts of a graft product of poly-12-hydroxystearic acid and methacrylic acid copolymer as a dispersion stabilizer, vinyl monomers (30% styrene, 30% methyl methacrylate, 2-ethyl Hexyl acrylate 23%,
Hydroxyethyl acrylate 15%, acrylic acid 2%
A non-aqueous dispersion resin was prepared by dispersion polymerizing 100 parts of a mixture consisting of the following in n-hebutane in a conventional manner. The heating residue of the disversion is 50%
, the degree of disversion was 20%.

Using this non-aqueous dispersion resin, a non-aqueous dispersion type metallic paint (M-2) containing an ultraviolet absorber was prepared in the following formulation.

50% non-aqueous dispersion 160 parts 60% melamine formaldehyde resin (Note 1) 33.3 parts Aluminum paste-B (Note 6) 12 parts Organic yellow pigment (Note 7) 0.01 part Carbon black (Note 4) ) 0.005 parts 10% ultraviolet absorber solution (
Note 5) 50 parts 20% light stabilizer solution (Note 8)
5 parts (Note 6) Product name Aluminum Paste 55-519 manufactured by Toyo Aluminum Co., Ltd. (Note 7) Product name Irgajinero-3RCTN manufactured by Ciba Geigy Mari Co., Ltd. (Note 8) Kijirol solution 2.8 of Sanol LS292 manufactured by Sankyo ■ Production example of clear paint (S-1): 30% styrene, 30% butyl methacrylate, 23% 2-ethylhexyl methacrylate, 15% hydroxyethyl methacrylate, 2% acrylic acid in Kyjirol using polymerization initiator azobisisobutyronitrile. Copolymerization was performed to obtain an acrylic resin solution having a heating residue of 50%, a solution acid value of 9.0, and a solution viscosity of H (Gardner, 25° C.).

A solution-type S-clear paint (S-1) was prepared using this acrylic resin solution.

50% acrylic resin solution 160 parts 60% melamine formaldehyde resin (Note 9) 33 parts 10% ultraviolet absorber solution (Note 5) 10 parts 20% light stabilizer solution (Note 8) 5 parts (Note 9) Manufactured by Hitachi Chemical ■ Product name: Melan #28 (butanol-modified melamine resin) Next, a mixed solvent consisting of 60 parts of Swasol #1000 (manufactured by Cosmo Oil ■, product name) and 40 parts of n-butanol was used to reduce the viscosity to 30 seconds (Ford cup #4/20°C). After adjustment, an S-clear paint (S-1) was obtained. (Refractive index of single coating film: 1.55) (S-2): 10 parts of methyl methacrylate, 30 parts of isobutyl methacrylate, 12 parts of n-butyl methacrylate, 20 parts of 2-ethylhexyl methacrylate, 25 parts of 2-hydroxyethyl methacrylate. and 3 parts of methacrylic acid in a xylene solution in the same manner as above to obtain an acrylic resin liquid 16 with a weight average molecular weight of 10,000 and a resin content of 50%.
After stirring and mixing 0 parts, 60% Kneepan 208E-6033 parts and 1% Raybow No. 3 [manufactured by Raybow Chemical Co., Ltd., 10.1 parts of silicone additive], the viscosity was 25 seconds using Swasol #1000 (Ford Cup No. 0.4/ 20'C) to obtain an S-clear paint (S-2). (Refractive index of single coating film: 1.52) 3. Manufacturing example of FNAD-clear paint (FNAD-clear (1)): Heptane 102 parts n-butyl acetate 8 parts Number stabilizer (manufactured by Asahi Glass Co., Ltd. [Lumiflon LF40064 weight average Molecular weight: 19,000, fluorine atom content: 30%, hydroxyl value: 100, acid value: 5) 108 parts were placed in a flask and heated to reflux, and the following monomers and polymerization initiator were added dropwise over 3 hours. After further aging for 2 hours, acetic acid n
-26 parts of butyl were added.

Styrene 15 parts Methyl methacrylate 40 parts Acrylonitrile
30 parts 2-hydroxyethyl methacrylate 15 parts T-hydroxyethyl peroxy 2-ethylhexanony 1.5 parts The obtained non-aqueous dispersion had a non-volatile content of 47%, a viscosity A, and a particle size of the polymer particles ( Measured using an electron microscope, hereinafter the same) 0.15 μm
It was a milky white stable low viscosity polymer dispersion. No precipitation or coarse particles were observed even after being left at room temperature for 3 months.

15 parts (solid content) of an amino resin (Note 1) is blended per 100 parts of resin solid content in this dispersion, and a 10% ultraviolet absorber solution (Note 5) is added per 100 parts of the total solid content of both resins. ) and 5 parts of 20% light stabilizer solution (Note 8), adjusted the viscosity to 20 to 40 seconds (Ford Cup #4/20°C) with Swasol #1000, and prepared FNAD-
Clear (1) was obtained. (Refractive index of single coating film 1.48)
(FNAD-Clear (2)): [200 parts of Lumiflon LF400J (nonvolatile content 50%, acid value 5, weight average molecular weight about 5000, hydroxyl group measurement 50, fluorine atom content a about 30%), glycidyl methacrylate 1-o, g part 0.02 part of 4-tart-butylpyrocatechol 0.1 part of dimetalaminoethanol was added, and a reflux reaction was carried out for 5 hours to introduce a copolymerizable double bond into the dispersion stabilizer molecular chain. did.

The decrease in the resin acid value was suppressed to within 0.02, and the number of double bonds introduced per molecular chain was within one.

Heptane 80 parts n-butyl acetate 8 parts Above dispersion stabilizer
130 parts of the mixture was placed in a flask, heated and refluxed, and the following monomers and polymerization initiator were added dropwise over 3 hours.After aging for 2 hours, 26 parts of n-butyl acetate was added.

Styrene 15 parts Methyl methacrylate 40 parts Acrylonitrile
30 parts 2-hydroxyethyl methacrylate 15 parts tertiary-butylperoxy 2-ethylhexanony 1-1.5 parts The obtained non-aqueous dispersion had a nonvolatile content of 47%, a viscosity D, and a particle size of 0.18.
It was a stable, low-viscosity polymer dispersion with a milky white color. No precipitation or coarse particles were observed even after being left at room temperature for 3 months.

Per 100 parts by weight of resin solid content in this dispersion liquid, 15 parts (solid content) of amino resin (Note 1) is blended, and furthermore, 1096 parts of ultraviolet absorber solution (solid content) is added per 100 parts of total solid content of both resins.
Blend 10 parts of Note 5) and 5 parts of 20% light stabilizer solution (Note 8), adjust the viscosity to 20 to 40 seconds (Ford Cup #4/20°C) with Swasol #1000, and prepare FN.
A D-clear (2) was obtained. (Refractive index of single coating film 1
．． 47) (FNAD-Clear (3)): Heptane 102 parts n-butyl acetate 8 parts Lumiflon LF200
108 parts were placed in a flask, heated to reflux, and the following monomers and polymerization initiator were added dropwise over 3 hours.
After further aging for 2 hours, 26 parts of n-butyl acetate was added.

Styrene 15 parts Methyl methacrylate - 1 17 parts Acrylonitrile
30 parts 2-hydroxyethyl methacrylate 15 parts glycidyl methacrylate 20
1 part metaxolic acid 3 parts tert-butyl peroxy 2-ethylhexanoate 1.5 parts The non-volatile content of the obtained non-aqueous dispersion was 46%, viscosity B, particle size 0.12μ
It was a milky white stable low viscosity polymer dispersion of m. No precipitation or generation of coarse particles was observed even after being left at room temperature for 3 months.

Per mole of hydroxyl group contained in the resin in this dispersion,
A polyisocyanate compound (manufactured by Nippon Polyurethane Co., Ltd., non-yellowing block isocyanate -D C-2725) was blended so that the number of isocyanate groups was 1 mole, and further 10% ultraviolet absorber solution (Note 5) IO part and Add 0.5 parts of 20% light stabilizer solution (Note 8) per 100 parts of resin solids, and then adjust the viscosity to 20-40 with cellosolve acetate.
FNA adjusted to seconds (Ford Cup #4/20°C)
D-clear (3) was obtained. (Refractive index of single coating film: 1.4
7) Examples and Comparative Examples A coated plate was prepared by applying a cationic electrodeposition primer for automobiles and an intermediate coating surfer to a mild steel plate that had been subjected to degreasing and phosphate chemical conversion treatment according to a conventional method. Apply the above-mentioned metallic paint to the painted surface using an air spray gun (manufactured by Iwata Painting Machine, trade name: Wider 71).
μ), after being left at room temperature for 3 minutes, the viscosity-adjusted S-clear paint was applied wet-on-wet using an air spray gun (manufactured by Iwata Painter, trade name: Wider 71) to a dry film thickness of 25μ. Afterwards, it was left for 1 minute. Next, FNAD-clear paint was coated in the same manner so that the dried film had a thickness of 15 μm, and was left for 10 minutes.Then, the metallic paint film and both clear paint films were heated in an electric hot air dryer at 140°C for 30 minutes. were cured at the same time.

These V-no metallic paints, S-clear paints and F
The coating process of the NAD-clear paint and the performance test results of the resulting metallic finish coating are shown in Table 1.

The test methods in Table 1 are as follows.

(*1) Each paint marked with an O mark was applied as described above and cured by heating.

(*2) After preparing the test plate as described in (*1) above, a performance test was immediately conducted.

(*3) Light reflectance (%) at incident angles of 60″ and 20° (*4) Sharpness PGD (Portable Glass Dist
Inctness) Visibility tester (*5) Visual judgment of fleshiness ◎: Good to ×: Poor (*6) Contact angle of water Pure water was placed on the painted surface using a syringe, and the contact angle was determined using a microscope. .

(*7) Smoothness Visual judgment ◎：Good △: Occurrence of yuzu skin is observed.

(*8) Performance tests were conducted on coated plates after 24 months of exposure at Okinoerabu.

(*9) QUV Accelerated Exposure Tester (Q Pane1
A test was conducted on the coating film after 120 cycles of UV irradiation at 16 hours/60°C and water coagulation at 150°C for 8 hours using an accelerated weathering tester (manufactured by Co., Ltd.).

(that's all)

Claims (1)

[Claims] (1) i) applying a metallic paint containing a metallic pigment and a thermosetting resin composition as a main component; ii) then applying a clear paint containing a thermosetting resin composition as a main component to the painted surface; iii) The radically polymerizable monomer is soluble in the presence of a dispersant consisting of an organic solvent-soluble fluoroolefin polymer having a weight average molecular weight of about 5,000 to 120,000 and a fluorine atom content of about 1 to 60% by weight. , and a clear paint whose main component is a non-aqueous dispersion obtained by polymerizing the radically polymerizable monomer in an organic solvent in which the polymer formed by the radically polymerizable monomer is insoluble, A metallic finishing method, which comprises: after coating the above-mentioned clear coated surface, iv) heating to simultaneously cure the above-mentioned three-layer coating film.