JPH09239312A - Formation of coating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel and highly useful method for forming a coating film capable of furnishing a coating film excellent especially in acid resistance, hardness, appearance, etc. SOLUTION: A hydroxyl-contg. acryl-modified chlorinated polyolefin as a resin component and a curing agent having reactivity toward hydroxyl are incorporated into an overcoat, and a hydroxyl-contg. vinyl polymer and a curing agent reactive to hydroxyl is incorporated into a base coat. Further, a vinyl polymer having two siloxyl groups in one molecule, a curing agent reactive to the hydroxyl generated from the polymer and a dissociation catalyst of the siloxy group are are incorporated into a clear coat, and the above-mentioned characteristics and performances are revealed to the maximum.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel and useful method for forming a coating film. More specifically, in the present invention, an undercoat paint is applied to a polyolefin base material to form an undercoat paint film, and then a base coat paint containing metallic powder and / or a coloring pigment is applied to the undercoat paint surface. Then, the present invention relates to a method for forming a coating film on a polyolefin-based substrate, which comprises coating the base coat paint with a clear coat paint.

[0002]

2. Description of the Related Art In recent years, in the automobile industry, weight saving has been attempted as an effective means for improving fuel consumption in view of resource saving, energy saving, environmental problems and the like. As one of them, the replacement of conventional metal materials with plastic materials is being actively promoted.

Among these, polyolefin base materials, which are inexpensive and have excellent moldability, have come to be used mainly for bumpers, but such polyolefin base materials are usually used for automobile cosmetics and cosmetics. It is often painted to give the product value of protection.

However, conventional paints formed of alkyd resin, acrylic resin, epoxy resin, etc. are not suitable for various molded products obtained from so-called crystalline polyolefin having a small polarity. In most cases, it does not have adhesiveness, and for this reason, it is known that chlorinated polyolefin having excellent adhesiveness is used for coating on such a polyolefin-based substrate.

However, in the case of such a method,
In particular, various properties such as hardness, solvent resistance, and weather resistance are poor, and the original functions of cosmetics and protection cannot be imparted, which is a fatal injury at present.

[0006] As a method for improving these various properties, Japanese Patent Publication No. 3-140269 discloses a resin composition which is cured with a hydroxyl group-containing acrylic modified chlorinated polyolefin and a polyisocyanate compound. Although the technology has been proposed, even if such a method significantly improves durability, hardness, and solvent resistance, it can be used in cases where it is exposed outdoors for a long period of time. Inevitably, the problem that the coating film deteriorates remains.

Therefore, the chlorinated polyolefin itself is used as the undercoating paint, and as the topcoating paint, both the base coat paint and the clear coat paint are used, and a hydroxyl group-containing alkyd resin, a hydroxyl group-containing acrylic resin, etc. are used. Although a method of applying by using a paint system that is combined with a melamine resin or a paint system that is combined with a polyisocyanate compound and a hydroxyl group-containing alkyd resin or a hydroxyl group-containing acrylic resin is known, However, such a method also has a drawback that the intercoat adhesion between the undercoat paint film and the overcoat paint film is low, and further, long-term durable adhesion to a polyolefin-based substrate is low. There is

In the case where a coating system in which a hydroxyl group-containing alkyd resin or a hydroxyl group-containing acrylic resin is combined with a polyisocyanate compound is used as the clear coat coating composition, such coating system is originally used. Since it is a two-component type, it is necessary to pay attention to the pot life.

If this pot life is adjusted within a practical range, it becomes difficult to obtain a coating film having a high hardness. Therefore, in order to increase the hardness, a alkyd resin containing a hydroxyl group or a hydroxyl group containing a hydroxyl group is contained. If the glass transition temperature (Tg) of acrylic resin or the like is increased or the amount of hydroxyl groups is increased, then the appearance of the coating film is deteriorated or the pot life is shortened.
It was not practical.

Further, when a coating system in which a melamine resin is combined with a hydroxyl group-containing alkyd resin or a hydroxyl group-containing acrylic resin as described above is used as a clear coat coating composition, such coating system is Although it has an excellent point that it is a one-pack type, it is difficult to say that the appearance of the coating film is excellent due to the heat shrinkage during curing, and moreover, the acid resistance of the melamine resin itself. Due to its poorness, there are still major problems such as deterioration of the coating film due to acid rain during exposure.

After all, a method of forming a coating film excellent in coating film properties such as acid resistance, coating film appearance, hardness and weather resistance on such a polyolefin-based substrate is The reality is that it has not yet been put to practical use.

[0012]

As described above, as long as the conventional technique is followed, the coating film has an excellent appearance and is excellent in the coating performance such as acid resistance and weather resistance. To find a highly practical and novel method of forming a coating film, which is excellent in adhesion to a polyolefin-based substrate and, in particular, gives a coating film which is durable in adhesion to the substrate for a long period of time. Was very difficult.

However, the inventors of the present invention are extremely practical in that they are particularly excellent in coating film performance such as appearance, acid resistance and weather resistance, and are also excellent in adhesion to a polyolefin-based substrate. In search of a high and innovative method of forming a coating film, he earnestly began research.

Therefore, the problem to be solved by the present invention is that it has an excellent coating film appearance and, in particular, is excellent in coating film properties such as acid resistance and weather resistance. It is an object of the present invention to provide a novel method of forming a coating film having extremely high practicability, which is to provide a coating film having excellent adhesion to the base material and excellent durability adhesion to the base material for a long period of time.

[0015]

Means for Solving the Problems Accordingly, the present inventors have:
Focusing on the problems to be solved by the invention as described above, as a result of earnestly and repeatedly studying, a specific undercoat paint was applied, and then, on the undercoated surface thus obtained,
By applying a base coat paint and then applying a specific clear coat paint on top of that base coat paint, we have found that such a problem can be solved brilliantly. The present invention has been completed here.

That is, basically, the present invention basically coats a polyolefin base material with an undercoat paint to form an undercoat paint film, and then forms a base coat on the coated surface of the undercoat paint. In a method for forming a coating film, which comprises coating a coating composition for a base coat, and then coating a coating composition for a clear coat on the coating composition for a base coat.

As the above-mentioned undercoat paint, a paint containing a hydroxyl group-containing acrylic modified chlorinated polyolefin (A) and a curing agent (B) having reactivity with a hydroxyl group as essential film-forming components is used. age,

Further, as the above base coating composition, a vinyl polymer (C) having a hydroxyl group and / or a polyester resin (D) having a hydroxyl group, which is mixed with metallic powder and / or a coloring pigment, and a hydroxyl group are reactive. And a curing agent (E) having

Further, as the above-mentioned clear coat coating composition, a vinyl polymer (F) having at least two siloxy groups in one molecule, and a curing compound having reactivity with a hydroxyl group produced from the polymer (F). An object of the present invention is to provide a method for forming a coating film, which comprises using a coating material containing the agent (G) and a siloxy group dissociation promoting catalyst (H) as essential coating film forming components.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The present patent application (hereinafter, abbreviated as "the present application") is directed to a polyolefin-based substrate, which is coated with an undercoat paint to form an undercoat paint film. In the method of forming a coating film, which comprises coating a base coat paint, and then applying a clear coat paint on the base coat paint.

As the above-mentioned undercoat paint, a paint containing a hydroxyl group-containing vinyl-modified chlorinated polyolefin (A) and a curing agent (B) having reactivity with the hydroxyl group as essential film-forming components is used.

Further, as the above base coating material, a vinyl polymer (C) having a hydroxyl group and / or a polyester resin (D) having a hydroxyl group, which is mixed with metallic powder and / or a color pigment, and the hydroxyl group Using a coating material containing a reactive curing agent (E) as an essential coating film forming component,

Further, as the above-mentioned clear coat coating composition, a vinyl polymer (F) having at least two siloxy groups in one molecule, and a curing compound having reactivity with a hydroxyl group formed from the polymer (F). Claimed is a method for forming a coating film, which comprises using a coating material comprising an agent (G) and a siloxy group dissociation promoting catalyst (H) as essential coating film forming components.

The present application also claims the above-mentioned method of using at least one compound selected from the group consisting of polyisocyanate compounds and amino resins as the curing agent (B) having reactivity with a hydroxyl group. Is something that

Furthermore, the present application also claims the above-mentioned method of using at least one compound selected from the group consisting of polyisocyanate compounds and amino resins as the curing agent (E) having reactivity with a hydroxyl group. Is something that

Furthermore, the present application uses a compound having both a siloxy group which forms a hydroxyl group by hydrolysis and a hydrolyzable silyl group bonded to a carbon atom as the vinyl polymer (F). Is also a request,

In addition, in the present application, as the above-mentioned curing agent (G) having reactivity with a hydroxyl group, at least one compound selected from the group consisting of polyisocyanate compounds, carboxylic acid anhydride group-containing compounds and epoxy compounds. The method of using is also claimed.

<< Structure >>

The present invention will be described in more detail below.

First, the above-mentioned polyolefin base material used for carrying out the method for forming a coating film according to the present invention means ethylene, propylene, 1-butene or 3
Refers to various molded articles and structures such as homopolymers or copolymers of various α-olefins such as -methyl-1-heptene,

Not only various types of molded products and structures of pure polyolefin as described above, but also so-called polymer alloys in the form of blending different kinds of resin materials are included. Of course, those reinforced with glass fiber and the like, and those in which various fillers such as titanium oxide, talc or silica are mixed are also included.

The above-mentioned hydroxyl group-containing vinyl-modified chlorinated polyolefin (A) to be used in the undercoat paint, which is used in carrying out the method for forming a coating film according to the present invention, is a hydroxyl group-containing unsaturated monomer. A vinyl-modified chlorine obtained by polymerizing vinyl-based monomers as an essential component with a specific chlorinated polyolefin, which is obtained by grafting the vinyl-based monomer onto the chlorinated polyolefin. Is a modified polyolefin,

Preferably, vinyl monomers containing a hydroxyl group-containing unsaturated monomer and an unsaturated carboxylic acid as essential components are polymerized with respect to a specific chlorinated polyolefin having a chlorination rate of 50% or less. This is a vinyl-modified chlorinated polyolefin obtained by grafting a vinyl-based monomer onto the chlorinated polyolefin.

In particular, the chlorinated polyolefin (a-0) having a chlorination rate of 50% or less is unsaturated with about 5 to about 30% by weight of the hydroxyl group-containing vinyl monomer (a-1). 0.1% to about 3% by weight of the carboxylic acid (a-2) and 0 of the polyester resin (a-3) having a polymerizable unsaturated double bond (hereinafter, also referred to as unsaturated bond) capable of copolymerization. ~ About 1
0% by weight,

The above-mentioned (a-1) and (a-, respectively)
2) and (a-3) and about 50 to 97.9% by weight of the other vinyl-based monomer (a-4) copolymerizable with the above (a-1). , (A-2), (a-3)
And the total amount of each of the monomers (a-4) is 100% by weight.
So that

Moreover, the chlorinated polyolefin (a-
0) and the solid content weight ratio of the mixture of the respective monomers are
Set the ratio to about 10:90 to about 90:10,
It is particularly desirable that the graft copolymer has a number average molecular weight of about 3,000 to about 40,000, which is obtained by polymerization in the presence of an organic solvent.

Here, the above-mentioned chlorinated polyolefin (a-0) generally refers to a polyolefin having a chlorination rate of 50% or less, preferably 10 to 40%, and particularly as such a polyolefin. To exemplify only representative ones, ethylene,
Various α-, such as propylene, 1-butene, 3-methyl-1-butene or 3-methyl-1-heptene, etc.
Homopolymers or copolymers of olefins;

Or an ethylene-vinyl acetate copolymer,
Ethylene-butadiene copolymer or ethylene-acrylic acid ester copolymer, such as a copolymer of α-olefins and other vinyl monomers,
Therefore, if only typical examples of the chlorinated polyolefin (a-0) are given, chlorinated polyethylene, chlorinated polypropylene, chlorinated ethylene-propylene copolymer or chlorinated ethylene-vinyl acetate Polymers and the like.

With respect to the chlorination rate of the chlorinated polyolefin (a-0), if the chlorination rate exceeds 50%, the adhesion to the polyolefin-based substrate is apt to decrease, so The determination of the chlorination rate should be made mainly in consideration of various coating film performances such as (base material) adhesion, flexibility and hardness, and preferably 10 to 40%. It should be within the range, more preferably within the range of 15 to 35%, and in this manner, the composition having the most balanced coating film performances can be obtained.

Further, only the representative examples of the above-mentioned hydroxyl group-containing vinyl monomer (a-1) are exemplified, 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth). Acrylate, 3
-Hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, di- 2-hydroxyethyl fumarate or mono-2-hydroxyethyl-monobutyl fumarate.

Further, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate,
2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate or 4-hydroxybutyl (meth) acrylate or 3-chloro-2
-Hydroxypropyl (meth) acrylate, di-2-
Hydroxyethyl fumarate or mono-2-hydroxyethyl-monobutyl fumarate was subjected to addition reaction with ethylenoxide, propylene oxide, butylene oxide or ε-caprolactone usually in the range of 1 to 6 mol. A so-called long chain hydroxyl group-containing monomer and the like are also included.

These may be used alone, in a combination of two or more kinds, or in the form of a combination with such a hydroxyl group-containing monomer before the addition reaction, and there is no problem, and the ratio of these may be desired. Needless to say, it should be decided each time according to the softness to be taken.

By the way, if a particularly representative amount of the hydroxyl group-containing vinyl monomer (a-1) is used, when it is less than 5% by weight, the reactivity with the hydroxyl group is inevitable. When it is combined with the curing agent (B) having the above-mentioned properties, the solvent resistance and the chemical resistance are likely to be insufficient. On the other hand, if it exceeds 50% by weight, the adhesion to the polyolefin material is inevitable. Since it tends to decrease, it is about 5 to the total weight of the monomers.
A range of about 50% by weight, preferably 5 to 40% by weight is suitable.

Further, the unsaturated carboxylic acid (a-
If only representative ones are given as 2),
Various unsaturated dicarboxylic acids such as maleic anhydride, fumaric acid, itaconic acid or citraconic acid; or various unsaturated monocarboxylic acids such as (meth) acrylic acid.

Then, the unsaturated carboxylic acid (a-2)
If the amount of these is less than 0.1% by weight, in particular, when they are combined with a curing agent (B) having reactivity with a hydroxyl group, the curing property is If the amount is too much higher than 3% by weight, the water resistance of the coating film tends to be inevitably reduced. To about 3% by weight, preferably 0.2 to 1.5% by weight.

Further, the above-mentioned polyester resin (a-3) having an unsaturated bond capable of copolymerization is, of course, used for so-called pigments having a small oil absorption, such as acid value titanium or halo. In short, above all, quinacridone,
It is used when it is desired to improve the dispersibility of various organic pigments such as phthalocyanine-based or azo-based pigments and pigments such as carbon black, which have poor dispersibility and have a relatively large oil absorption. In that sense, it can be said that the polyester resin does not contribute so much to the coating film performance itself.

As the polyester resin (a-3), only typical ones are exemplified, so-called alkyd resins modified with oils or fatty acids, and further these oils and fats. Depending on the kind,
Although any of the so-called oil-free alkyd resins in the unmodified form can be used, in the present invention, among these various alkyd resins, particularly, copolymerizable with various vinyl monomers It is possible to say that those having an unsaturated bond are particularly suitable.

At this time, as such an alkyd resin, either a saturated fatty acid or a non-drying oil (fatty acid) modified type which does not have a copolymerizable unsaturated bond or has a small number of unsaturated bonds, or further, For the type of oil-free alkyd resin which is not modified with oil or fatty acid, a copolymerizable unsaturated bond to be a grafting point for other various vinyl monomers,
Needless to say, it is necessary to introduce various unsaturated carboxylic acids such as (anhydrous) maleic acid and fumaric acid into the alkyd resin.

The alkyd resin thus obtained is usually used in the range of 0 to about 10% by weight, but when it is used in an excessively large amount exceeding about 10% by weight, Inevitably, it becomes inferior in solvent resistance and stain resistance, which is not preferable.

Then, each of the above (a-
1), (a-2) and (a-3) and other vinyl-based monomer (a-4) copolymerizable therewith, styrene, various aromatic vinyl monomers such as α-methylstyrene, vinyltoluene, α-chlorostyrene;

Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, iso (i- or iso-) propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) ) Acrylate, tert-butyl (meth)
Acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, norbornyl (meth) acrylate, isobornyl (meth) acrylate, dibromopropyl (meth) acrylate, tribromophenyl Various (meth) acrylates such as (meth) acrylate or alkoxyalkyl (meth) acrylate;

Glycidyl (meth) acrylate, β-
Various epoxy group-containing monomers such as methyl glycidyl (meth) acrylate or (meth) allyl glycidyl ether;

2,3-carbonate propyl (meth) acrylate, 2-methyl-2,3-carbonate propyl (meth) acrylate, 4-methyl-3,4-carbonate butyl (meth) acrylate, 3-methyl-3,
Various cyclocarbonate group-containing vinyl monomers such as 4-carbonate butyl (meth) acrylate and 5-ethyl-5,6-carbonate hexyl (meth) acrylate;

Diesters of various unsaturated dicarboxylic acids such as maleic acid, fumaric acid or itaconic acid with monohydric alcohols; vinyl acetate, vinyl benzoate or "Veova" (branched Ciel, Netherlands) Of various vinyl esters such as vinyl aliphatic monocarboxylic acid vinyl ester);

"Biscoat BF, BFM, 3F or 3FM" [trade name of fluorine-containing acrylic monomer manufactured by Osaka Organic Chemical Co., Ltd.], perfluorocyclohexyl (meth) acrylate, diperfluorocyclohexyl fumarate or N -Vinyl esters, -vinyl ethers,-(meth) acrylates or -unsaturated carvone containing various (per) fluoroalkyl groups such as -i-propyl perfluorooctanesulfonamidoethyl (meth) acrylate. Various fluorine-containing compounds such as acid esters;

Alternatively, there are various nitrogen atom-containing compounds such as (meth) acrylamide or (meth) acrylonitrile; various halogenated olefins such as vinyl chloride, vinylidene chloride, vinyl fluoride or vinylidene fluoride.

When the above-mentioned various monomers (mixture) are polymerized with the above-mentioned chlorinated polyolefin (a-0), these chlorinated polyolefin and monomer ( The ratio of the mixture) to be used is within the range of the solid content weight ratio of about 10:90 to about 90:10, preferably 15:85 to 60: 4.
It is suitable that the solid content weight ratio is 0.

Through such a polymerization reaction, the vinyl-based monomer component is grafted to the chlorinated polyolefin component, and as a result, a so-called graft, which is a modified chlorinated polyolefin in a form in which good compatibility is imparted. Although a copolymer is obtained, as a method of such a polymerization reaction, a known method such as benzoyl peroxide or azobisisobutyronitrile is usually used at a polymerization temperature in the range of about 60 to 100 ° C. It is preferable to carry out solution polymerization using various conventional radical-generating polymerization initiators.

In this case, the above-mentioned ratio of the chlorinated polyolefin (a-0) to the monomer (mixture) exceeds about 10: about 90 in terms of solid content weight ratio, If the amount of the chlorinated polyolefin is too small, the adhesion to the polyolefin-based substrate tends to be inevitably decreased, which is not preferable. On the other hand, if it exceeds about 90:10, too, When the amount of the chlorinated polyolefin increases, the solvent resistance of the resulting coating film is inevitably lowered, which is not preferable.

Here, only the representative examples of the above-mentioned organic solvents are exemplified, and toluene and xylene are well known as good solvents for chlorinated polyolefins. In addition to these, butyl acetate, especially n-butyl acetate, butanol, or the like can be used within a range that does not impair the solubility.

The graft copolymer thus obtained has a number average molecular weight (Mn) of about 3,0.
0 to about 40,000, preferably about 5,000 to 30,000, for molecular weights below about 3,000. Inevitably, in terms of mechanical strength, etc., it tends to be insufficient, while on the other hand, about 4
When the molecular weight is higher than 10,000, it tends to be difficult to obtain a sufficient molecular weight in terms of spraying workability and the like, which is not preferable in any case.

Next, as the above-mentioned curing agent (B) having reactivity with a hydroxyl group, which is one of the essential components constituting the above-mentioned undercoat paint used in carrying out the method of the present invention. It is usually desirable to use amino resins and / or polyisocyanate compounds. Above all, this amino resin is particularly preferable from the viewpoint of ease of use.

As the amino resins, only representative ones are exemplified, and the alkyl etherified melamine resins and the like are given, and only the particularly representative alkyl etherified melamine resins are exemplified. ,

"Super Beckamine L-117-6
0 "[Dainippon Ink and Chemicals Co., Ltd. product] or" Uban 225 "[Mitsui Toatsu Chemicals Co., Ltd. product], butoxymethyl melamine resin;" Cymel # 300 "
Or # 303 ”[Mitsui Cyanamid product]
Or various methoxymethyl melamine resins such as "Sumimar M-100" [product of Sumitomo Chemical Co., Ltd.];

Alternatively, various methoxy / poxy mixed etherified methyl melamine resins such as "Cymel # 1130" (product of the same company) or "Sumimar M-66B" (product of the same company) are used.

The amount of the amino resin used is appropriately in the range of 5 to 40% by weight, preferably 10 to 30% by weight, based on the total amount of the resin. is there.

In the present invention, a so-called curing catalyst can be used to accelerate the curing of the undercoat paint, but as a curing agent (B) having reactivity with a hydroxyl group,
In the case of using an amino resin, only representative ones of such curing catalysts are exemplified. Paratoluenesulfonic acid (p-toluenesulfonic acid), dodecylbenzenebenzenesulfonic acid or dinonylnaphthalenedisulfonic acid or Various acid catalysts such as these amines and blocked compounds, half-esterified compounds of tetrachlorophthalic anhydride and monohydric alcohol, and various organic acids such as trichloroacetic acid;

Alternatively, various phosphoric acid compounds such as monoalkyl phosphoric acid, dialkyl phosphoric acid, monoalkyl phosphorous acid or dialkyl phosphoric acid, or triphenylphosphine can be used. And, as the usage amount of the curing catalyst,
A suitable range is about 0.1 to about 10% by weight based on the total amount of the resin.

Further, it goes without saying that a block isocyanate, an epoxy resin or the like can be used as a curing agent, if necessary.

In the present invention, the undercoating paint has a hydroxyl value (OH value) of about 50 to about 200,
Moreover, linear or branched polyester polyols and / or polyether polyols can be used as required.

As typical examples of the polyol, polyethylene glycol ether, polypropylene glycol ether, polytetramethylene glycol, polycaprolactone polyol and the like can be mentioned, and these can be used alone or in combination of two or more kinds. But it's okay.

The type of the polyol component and the amount thereof to be used should be determined by the hardness of the resin skeleton such as acrylic resin or amino resin, and the glass transition temperature (Tg) of the acrylic resin used. When a polyol having a low hydroxyl value is used, it is preferable that the amount of the polyol used is small and the hydroxyl value is high.

The amount used is 10% of the solid content of the above-mentioned hydroxyl group-containing vinyl-modified chlorinated polyolefin (A).
A proportion of less than about 50 parts by weight with respect to 0 parts by weight is suitable. If it is used in an excessively large amount, exceeding about 50 parts by weight, the solvent resistance is inevitably deteriorated, which is not preferable.

The above-mentioned base coat paint used in the present invention means a vinyl polymer (C) and / or polyester resin (D) having a hydroxyl group, respectively, in a form in which metallic powder and / or a coloring pigment are blended. ) And a curing agent (E) having reactivity with the hydroxyl group as essential film-forming components, and various known and conventional types may be used. .

Specifically, a vinyl polymer (C) such as a commonly used acrylic resin having a hydroxyl group and / or a conventionally used polyester resin (D) having a hydroxyl group and a polyisocyanate compound, respectively. And / or a curable resin composition in the form of a combination of a hydroxyl group which is an amino resin and a curing agent (E) having reactivity,
Metallic powder and / or a coloring pigment are blended as an essential coating film forming component.

The polyester resin as used herein also includes an alkyd resin modified with an oil or a fatty acid. Further, cellulose acetate butyrate or the like may be used.

To give only representative examples of the paint for the base coat, organic solvent-soluble resins, non-aqueous dispersion resins, etc.
Further, any type of so-called water-based base coat containing a water-soluble resin and / or an emulsion resin as a main component can be used.

Next, the above-mentioned clear coat paint, which is one of the main constituents used in carrying out the method for forming a coating film according to the present invention, will be explained. The coating material for coating is a vinyl polymer (F) having at least two siloxy groups in one molecule, a curing agent (G) having reactivity with a hydroxyl group generated from the polymer (F), It refers to a coating system in which a siloxy group dissociation promoting catalyst (H) is contained as an essential coating film forming component.

Here, the above-mentioned vinyl polymer (F) having at least two siloxy groups in one molecule.
And has at least two siloxy groups represented by the following general formula [I] in one molecule, and
It refers to a compound having a structure in which the siloxy group is bonded to a carbon atom.

[0080]

Embedded image

[Wherein R ¹ has ¹ to 18 carbon atoms]
Or an phenyl group, an aryl group or an aralkyl group, and R ² and R ³ are the same or different and each represent a hydrogen atom or a halogen atom, or At least one atomic group selected from the group consisting of an alkyl group, a cycloalkyl group, an alkoxyl group, a cycloalkoxy group, an aryl group, an aryloxy group, an alkanoyloxy group, an aralkyl group, an aralkyloxy group, a nitrile group and a halogen atom. An alkyl group having 1 to 18 carbon atoms, which may or may not be substituted with, or an aryl group, a cycloalkyl group, an aralkyl group, an alkanoyl group, an alkoxyl group, an aryloxy group, a cycloalkoxy Group, aralkyloxy group or alkanoyloxy group Shall be represented. ]

To give only examples of such typical siloxy groups, trimethylsiloxy group, triethylsiloxy group, triphenylsiloxy group,
Examples thereof include a dimethylethoxysiloxy group and a triethoxysiloxy group, and above all, a trialkylsiloxy group or a trialkoxysiloxy group has a preferable structure.

To obtain the vinyl polymer (F), for example, a vinyl monomer having a siloxy group as described above is polymerized alone, or the siloxy group-containing vinyl monomer is used. Of the hydroxyl group-containing vinyl polymers previously prepared by copolymerizing the polymer with other monomers copolymerizable with the monomer, such as chlorosilane. The siloxy group-containing vinyl polymer (F) can be prepared by reacting with a silylating agent, or by a method such as an alcohol exchange reaction between an alkoxysilane and a hydroxyl group. However, the method (3) is preferable because of its ease of preparation.

Only typical examples of the siloxy group-containing vinyl-based monomer (f-1) used when the vinyl-based polymer (F) is prepared by the above-mentioned method are exemplified. If it stops, 2-trimethylsiloxyethyl (meth) acrylate, 2-trimethylsiloxypropyl (meth) acrylate, 4-trimethylsiloxybutyl (meth) acrylate, 2-triethylsiloxyethyl (meth) acrylate, 3-tributylsiloxypropyl ( And (meth) acrylate, 2-trimethylsiloxyethyl vinyl ether, 4-trimethylsiloxybutyl vinyl ether or 2-trimethylsiloxyethyl-allyl ether.

Such siloxy group-containing monomer (f-1)
Is used alone or in 2 of the monomer (f-1).
It goes without saying that more than one kind may be used in combination.

The siloxy group-containing vinyl monomer (f-
As the other monomers (f-2) copolymerizable with 1), the above-mentioned hydroxyl group-containing vinyl monomer (a-1) and unsaturated carboxylic acid (a-3) are respectively listed. Alternatively, it may be used by appropriately selecting from various monomers such as vinyl-based monomer (a-4).

Among these monomers (f-2), the vinyl-based polymer (F) having at least two siloxy groups in one molecule as described above, the present invention is further effective. In order to form a coating film having excellent properties such as acid resistance, coating film appearance, hardness and weather resistance on a polyolefin-based substrate, it is bonded to a carbon atom. It is desirable that a hydrolyzable silyl group (hereinafter referred to as a hydrolyzable silyl group) be present together.

Here, the vinyl polymer (A)
The above-mentioned hydrolyzable silyl group, which should be present together with the siloxy group, means a compound represented by the following general formula [II].

[0089]

Embedded image

[Wherein R ⁴ is a hydrogen atom or an alkyl group, an aryl group or an aralkyl group, and R ⁵ is a halogen atom or a (substituted) alkoxy group, an acyloxy group, a phenoxy group, a mercapto group, an amino group or an iminooxy group. Group or an alkenyloxy group,
In addition, a is an integer of 0, 1 or 2. ]

As only specific examples of such hydrolyzable silyl group, halosilyl group, alkoxysilyl group, acyloxysilyl group, phenoxysilyl group, mercaptosilyl group, aminosilyl group,
Although it is an iminooxysilyl group or an alkenyloxysilyl group, it can be said that the alkoxysilyl group has a preferable structure in terms of not generating an undesirable volatile component during curing.

In order to allow the hydrolyzable silyl group to be contained in the vinyl polymer (F), the above-mentioned monomer (which is used when the vinyl polymer (F) is prepared ( In part or all of f-2), a hydrolyzable silyl group-containing vinyl monomer [wherein the monomer is (f
-3). ] Is used.

As only specific examples of the hydrolyzable silyl group-containing vinyl monomer (f-3), 3- (meth) acryloyloxypropyltrichlorosilane and 2- (meth ) Acryloyloxypropyldichlorosilane, allylmethyldichlorosilane; 3- (meth) acryloyloxypropyltrimethoxysilane, 3- (meth) acryloyloxypropyltriethoxysilane, 3- (meth) acryloyloxypropylmethyldimethoxysilane, allyltri Methoxysilane; vinyltriphenoxysilane, bis (dimethylamino) methylvinylsilane, etc., but are by no means limited to these examples.

It goes without saying that the hydrolyzable silyl group-containing vinyl monomer (f-3) may be used alone or in combination of two or more kinds.

Various known and conventional methods can be applied to prepare the vinyl polymer (F) from various vinyl monomers as listed above.
Above all, the solution polymerization method using a radical polymerization initiator, that is, a method such as a solution radical polymerization method is the simplest.

The amount of siloxy groups to be introduced into the vinyl polymer (F) is in terms of curability and the like.
The repeating unit having a siloxy group is appropriately within the range of about 1 to 100% by weight, preferably within the range of 3 to 100% by weight, based on the solid content of the polymer (F).

Further, the number average molecular weight of the polymer in a state where the vinyl copolymer (F) has produced a hydroxyl group by hydrolysis is appropriately in the range of about 1,000 to about 50,000. On the other hand, the hydroxyl value of the polymer in the same state is appropriately within the range of about 20 to about 200.

In the case of a vinyl polymer which does not fall within these ranges, the curability and the like are inevitably deteriorated, and the storage stability is remarkably deteriorated. Is also not preferable.

Next, as the above-mentioned curing agent (G) having reactivity with a hydroxyl group, any compound can be used as long as it is a compound having at least two hydroxyl group-reactive groups in the molecule (hydroxyl group reactive group). Can also be used,
In particular, at least one compound selected from the group consisting of polyisocyanate compounds, carboxylic acid anhydride group-containing compounds and epoxy compounds from the viewpoint of acid resistance, ease of handling, and the performance of the coating film formed. Is preferred.

Of the compounds (G), only representative polyisocyanate compounds are exemplified, and various aromatic diisocyanates such as tolylene diisocyanate or diphenylmethane diisocyanate; or hexa Various aliphatic diisocyanates such as methylene diisocyanate or trimethylhexane diisocyanate;

Isophorone diisocyanate, methylcyclohexane-2,4 (2,6) -diisocyanate,
Various alicyclic diisocyanates such as 4,4-methylenebis (cyclohexylisocyanate) or 1,3- (isocyanatomethyl) cyclohexane;

Various diisocyanates such as those mentioned above, various polyhydric alcohols such as ethylene glycol, trimethylolethane or trimethylolpropane, and various polyethers such as polyethylene glycol or polypropylene glycol. Additives with relatively low molecular weight polyester resins (including oil-modified types) and acrylic copolymers such as polyols and polycaprolactone / polyols having functional groups that react with isocyanate groups;

Alternatively, a polyisocyanate having a so-called buret structure, which is obtained by reacting various diisocyanates as described above with water; or a so-called isocyanurate ring-containing product, which is obtained by cyclopolymerizing diisocyanates Examples include polyisocyanates.

Among the curing agents (G), only the typical ones of the carboxylic acid anhydride group-containing compound and the epoxy compound, respectively, will be exemplified. A vinyl polymer and a polyester polymer will be given. , Various polymers such as polyether polymers or epoxy resins, and the presence of carboxylic acid anhydride groups and epoxy groups in the various polymers and resins listed above. , Various compounds and the like.

Of the above curing agents (G), only those particularly representative as vinyl polymers will be exemplified.
Examples thereof include acrylic type, vinyl ester type, aromatic vinyl type, polyolefin type, chlorinated olefin type, or fluoroolefin type vinyl polymer.

The vinyl polymer of the curing agent (G) can be obtained by homopolymerizing a vinyl monomer having a carboxylic acid anhydride group, an epoxy group, or the like, or copolymerizable as described above. It can be easily prepared by copolymerizing with other monomers (f-2).

Here, of the curing agents (G), only typical vinyl monomers having an acid anhydride group, which are used when preparing the vinyl polymer, are exemplified. If so, maleic anhydride, itaconic anhydride or methacrylic anhydride, various carboxylic acid anhydride group-containing unsaturated monomers, and the like,

Specific examples of the vinyl-based monomer having an epoxy group include only glycidyl (meth) acrylate, allyl glycidyl ether, 3,4-epoxycyclohexyl (meth) acrylate or vinylglycidyl. There are various epoxy group-containing unsaturated monomers such as ether, but of course, in particular,
It is by no means limited to the compounds of these examples only.

Of the curing agents (G), compounds having a carboxylic acid anhydride group, which are particularly representative of compounds other than vinyl polymers, are listed below. Trimellitate) or various polyhydric carboxylic acid anhydrides represented by anhydrous ethylene glycol di (trimellitate).

Further, among the curing agents (G), compounds having an epoxy group, which are particularly representative as compounds other than vinyl-based polymers, are exemplified. Ethylene glycol diglycidyl Various polyglycidyl ethers of various polyhydric alcohols such as ethers, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether or glycerin triglycidyl ether;

Various polyglycidyl esters of various polycarboxylic acids such as diglycidyl ester of phthalic acid, diglycidyl ester of isophthalic acid or diglycidyl ester of adipic acid; or glycidyl ether type of bisphenol A or bisphenol F Epoxy resin, novolac type epoxy resin or epoxy resin containing hydantoin ring;

An alicyclic epoxy resin having at least two alicyclic oxirane groups in one molecule, as represented by "Eporide GT series" [a product of Daicel Chemical Industries, Ltd.] or p And so-called polyepoxy compounds such as various epoxy resins such as glycidyl ester ether of oxybenzoic acid.

Further, the above-mentioned dissociation promoting catalyst (H) used in carrying out the method for forming a coating film according to the present invention means that the siloxy group contained in the above-mentioned vinyl polymer (F) becomes water. It is a compound which is hydrolyzed by the reaction of and promotes regeneration of hydroxyl groups. Among them, to mention only representative ones, phosphoric acid, phosphoric acid ester, phosphorous acid ester, unsaturated group-containing phosphoric acid ester,

P-toluenesulfonic acid or an amine salt thereof; various acidic catalysts such as benzoic acid, trichloroacetic acid, naphthalenedisulphonic acid or an amine salt thereof;

Tetramethylammonium fluoride, tetraethylammonium chloride, tetramethylammonium bromide, trimethylbenzylammonium hydroxide, 2-hydroxypyridine, trimethylammonium methoxide, phenyltrimethylammonium chloride, phenyltrimethylammonium bromide, phenyltrimethylammonium hydroxide. Side, phenyltrimethylammonium iodide, phenyltrimethylammonium bromide, phosphocholine chloride sodium salt,

Stearyl ammonium bromide, tetra-n-butylammonium hydroxide, tetra-n-butylammonium phosphate, tetra-n
-Dodecyl ammonium trichloride, tetraethyl ammonium hydroxide, tetraethyl ammonium tetrafluoroborate, acetylcholine bromide, alkyldimethylbenzyl ammonium chloride, benzyl choline bromide, benzyl-n-butyl ammonium bromide, betaine, butyryl chloride, bis (tetra Various quaternary ammonium salts, such as -n-butylammonium) dichromate or trimethylvinylammonium bromide;

Allyltriphenylphosphonium chloride, n-amyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride,
Bromomethyltriphenylphosphonium bromide,
2-dimethylaminoethyltriphenylphosphonium bromide, ethoxycarbonylphosphonium bromide, n-heptyltriphenylphosphonium bromide, methyltriphenylphosphonium bromide,
Various phosphonium salts such as tetrakis (hydroxymethyl) phosphonium sulphate or tetraphenylphosphonium bromide;

Metal salts of various carboxylic acids such as alkyl titanates, octylates, dibutyltin dilaurates or lead octylates; various sulfide-type or mercaptide-type organic compounds such as monobutyltin sulfide or dioctyltin mercaptide Various alkaline catalysts such as lithium hydroxide or potassium hydroxide;

Amines such as ethylenediamine, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, butylamine, dibutylamine, tert-butylamine, hexylamine, 2-ethylhexylamine, triethylamine, diethanolamine and triethanolamine;

1,8-diazabicyclo (5,4,0) undecene-7 or 1,4-diazabicyclo (2,3)
2,2) various basic catalysts such as octane; or various carbonates such as calcium carbonate.

The addition amount of these catalysts is about 0.001 to about 10 with respect to the vinyl polymer (F) described above.
% Is suitable, and preferably 0.005
A range of 6% is suitable.

In order to further improve the stability of the clear coat coating composition used in the present invention thus obtained, a so-called water binder (water scavenger) is added.
Can also be added.

Of the compounds which can be used as such a water-binding agent, only typical ones are exemplified, and various trialkyl orthoformates such as trimethyl orthoformate, triethyl orthoformate or tributyl orthoformate; Various trialkyl orthoacetates such as trimethyl orthoacetate, triethyl orthoacetate or tributyl orthoacetate; various trialkyl orthoborates such as trimethyl orthoborate, triethyl orthoborate or tributyl orthoborate;

Various tetra (substituted) alkyl silicates simple substances such as tetramethyl silicate, tetraethyl silicate, tetrabutyl silicate, tetra (2-methoxyethyl) silicate or tetra (2-chloroethyl) silicate; tetraphenyl silicate or tetrabenzyl Various same-effect substances (hereinafter referred to as the following) of the above-mentioned tetra (substituted) alkyl silicates such as silicate
It is abbreviated as a single effect. );

Alternatively, various types such as "ethyl silicate 40" (trade name of tetramer, tetramer, pentamer or hexamer of tetraethyl silicate, manufactured by Colcoat Co., USA) such as dimer, trimer, tetramer or hexamer of tetraethyl silicate. A variety of hydrolyzable ester compounds such as the above-mentioned tetra (substituted) alkyl silicates simple substance and condensates of the same effective simple substance of the silicates;

Further, phenyl isocyanate, p-
Such as chlorophenyl isocyanate, benzene sulfonyl isocyanate, p-toluene sulfonyl isocyanate or isocyanate ethyl methacrylate,
Examples include various isocyanate group-containing compounds.

When various water binders are added as described above, the amount of the water binder to be used is 0. 1 with respect to the total amount of resin solids constituting the clear coating composition. 1 to 20% by weight, preferably
It may be about 0.5 to 10% by weight.

The clear coating composition for use in the present invention thus obtained is, if necessary, a known conventional agent such as a leveling agent, a rheology control agent, a light stabilizer or an ultraviolet absorber. It is also possible to mix various additives of the above.

Various known and commonly used cellulosic compounds, plasticizers, polyester resins and the like can also be incorporated.

As a method for forming a coating film on a polyolefin-based material by using the undercoat paint, the base coat paint and the clear coat paint used in the present invention, a usual method may be used. Can be done.

That is, although the polyolefin-based material may not be subjected to a pretreatment for painting, it is usually used.
A so-called pretreatment is carried out for the purpose of removing the mechanical oil and the release agent adhering to the surface of the plastic molded product, and improving the adhesiveness.

Examples of the pretreatment method include solvent wiping for the purpose of removing the adhesive on the surface, water-based cleaning using a water-based cleaning agent, steam cleaning with trichloroethane, etc., and flame treatment. Alternatively, there is plasma treatment or the like.

In the method for forming a coating film according to the present invention, an undercoat paint, a base coat paint and a clear coat paint are applied. As the coating method at that time, spray coating, electrostatic coating and the like are preferable. Although the coating intervals are not particularly limited, when applying the clear coat paint, after applying the base coat paint, the base coat paint is dried to the touch or semi-cured. It is particularly desirable to do this at some point.

Drying conditions after applying the respective coatings may be room temperature drying or heat drying. The coating equipment and drying equipment at that time, the type of each coating and their characteristics, etc. According to this, it may be determined appropriately.

Thus, the film thickness of each coating film formed by the method of the present invention is, as a dry film thickness, about 5 to about 15 micrometers (μ) in the case of an undercoat paint.
m), in the case of base coat paint, about 15 to about 30μ
m, and about 20 for clear coat paint
It is desirable to adjust the thickness to about 60 μm.

[0136]

EXAMPLES Next, the present invention will be described more specifically with reference examples, examples and comparative examples. However, the present invention is by no means limited to only these illustrative examples. Absent. In the following, all parts and percentages are by weight unless otherwise specified.

Reference Example 1 [Preparation Example of Vinyl-Modified Chlorinated Polyolefin (A)] In a reaction vessel equipped with a stirrer and a cooler, "Hardlen 14ML" [trade name of chlorinated polypropylene manufactured by Toyo Kasei Co., Ltd.] Chlorination rate = 26%, solid content (nonvolatile content) = 30%] and 800 parts of toluene
The temperature inside the container was raised to 80 ° C.

There, methyl methacrylate (MMA)
200 parts, isobutyl methacrylate (IBMA) 200 parts, ethyl acrylate (EA) 300 parts, 2
-Hydroxyethyl methacrylate (HEMA) 14
A dissolved product obtained by dissolving 0 part and 10 parts of methacrylic acid (MAA), 5 parts of benzoyl peroxide (BPO) and 5 parts of azobisisobutyronitrile (AIBN) in 350 parts of n-butyl acetate. And were added dropwise over 3 hours.

After that, when the polymerization reaction was continued by keeping the same temperature for 12 hours, the nonvolatile content was 40.2.
A solution of vinyl-modified chlorinated polyolefin (A), which was a chlorinated polypropylene-modified acrylic resin and had a number average molecular weight of 25,000, was obtained. Hereinafter, this is abbreviated as a copolymer (A-1).

Reference Example 2 (Same as above) A reaction vessel similar to Reference Example 1 was charged with "Hardlen 14M.
660 parts of "L" and 688 parts of toluene were added, and the temperature inside the container was raised to 80 ° C.

There, 350 parts of MMA, 180 parts of cyclohexyl methacrylate (CHMA), and 262 of "Plaxel FM-1" [trade name of hydroxyethyl methacrylate-ε-caprolactone adduct manufactured by Daicel Industries, Ltd.] Parts and 10 of methacrylic acid (MAA)
And 6 parts of benzoyl peroxide (BPO) and 4 parts of azobisisobutyronitrile (AIBN),
A lysate dissolved in 350 parts of n-butanol was mixed with 3 parts.
Dropped over time.

After that, when the polymerization reaction was continued by keeping the same temperature for 12 hours, the nonvolatile content was 40.8.
A solution of vinyl-modified chlorinated polyolefin (A), which is a chlorinated polypropylene-modified acrylic resin and has a number average molecular weight of 27,000, was obtained. Hereinafter, this is abbreviated as copolymer (A-2).

Reference Examples 3 and 4 (preparation examples of undercoat paint) 1 each of copolymer (A-1) or (A-2)
12.5 parts, 40 parts of titanium oxide and 20 parts of xylene
The white enamel was obtained by kneading each part with a sand mill for 1 hour.

Next, to each of these white enamel, 25 parts of "Super Beckamine L-117-60" (trade name of amino resin manufactured by the above-mentioned company; solid content = 60%) and "Nature Cure N-5225" were added. 1.6 parts of [trade name of dodecylbenzene sulfonate amine blocked product manufactured by Kusumoto Kasei Co., Ltd.] were added, and then toluene / xylene / n-butanol = 20/60/20 (weight part ratio) )
It was diluted to a spray viscosity with a thinner. Hereinafter, the one using the copolymer (A-1) is abbreviated as the undercoat paint (P-1), and the one using the copolymer (A-2) is the undercoat paint (P-2). Is abbreviated.

Reference Example 5 (Preparation Example of Base Coat Paint) A resin composition for paint which was formulated by a conventional paint manufacturing method so as to have the following ratio was used as a solvent for dilution [xylene / toluene]. / N-butyl acetate / methyl ethyl ketone = 30/30/20/20 (parts by weight ratio)], Ford Cup NO. In step 4, the viscosity was adjusted so as to be 11 to 12 seconds, whereby a base coat paint was prepared. Hereinafter, this paint for base coat is referred to as (BC-1)
Abbreviated.

77 parts of "Beckolite GF-542" [trade name of hydroxyl group-containing polyester resin manufactured by Dainippon Ink and Chemicals, Inc .; nonvolatile content = 65%] "Super Beckamine L-117-60" 42 parts ( Trade name of n-butylated melamine resin manufactured by the above-mentioned company; nonvolatile content = 60%) "CAB-381-0.5" 25 parts (trade name of cellulose acetate butyrate manufactured by Eastman Kodak Company, USA) ) "EPOLEN N-10" 15 parts (wax manufactured by the same company) "Alpaste 1860YL" 23 parts [trade name of aluminum paste manufactured by Toyo Aluminum Co., Ltd .; nonvolatile content = 65%] "Nakeure N-5225" 1 copy

Reference Example 6 (Same as above) A resin composition for paints, which was prepared by a conventional paint production method so as to have the following ratio, was diluted with a solvent for dilution [xylene / toluene / n-butyl acetate]. / Methylethylketone = 30/30/20/20 (parts by weight ratio)], Ford Cup No. In step 4, the viscosity was adjusted to 13 to 14 seconds to obtain a base coat paint. Hereinafter, this base coat coating material is (BC-2)
Abbreviated.

“Acridic 47-712” 160 parts [trade name of hydroxyl group-containing acrylic resin manufactured by Dainippon Ink and Chemicals; non-volatile content = 50%] “Super Beckamine L-117-60” 33 parts “ Alpaste 1860YL ”23 parts“ Fastgen Blue NK ”2 parts [trade name of cyanine blue pigment manufactured by Dainippon Ink and Chemicals, Inc.]“ Nature Cure N-5225 ”1 part

Reference Example 7 (same as above) A resin composition for paints, which was formulated by a conventional paint production method so as to have the following ratio, was diluted with a solvent for dilution [xylene / toluene / n-butyl acetate]. / Methylethylketone = 30/30/20/20 (parts by weight ratio)], Ford Cup No. In step 4, the viscosity was adjusted so as to be 11 to 12 seconds, whereby a base coat paint was prepared. Hereinafter, this base coat coating material is (BC-3)
Abbreviated.

“Acridic 47-567” 100 parts [Product name of hydroxyl group-containing acrylic resin manufactured by Dainippon Ink and Chemicals; non-volatile content = 50%] “Bernock DN-950” 18 parts (manufactured by the same company) Of the polyisocyanate compound; non-volatile content = 75%) "Taipaque CR-93" 60 parts [trade name of titanium oxide manufactured by Ishihara Sangyo Co., Ltd.]

Reference Example 8 [Preparation Example of Vinyl Polymer (F)] In a reaction vessel similar to that of Reference Example 1, 500 parts of toluene and 50 parts of n-butyl acetate were placed and the temperature inside the vessel was 110 ° C.
The temperature was raised to.

Then, a monomer mixture containing 300 parts of styrene, 280 parts of trimethylsiloxyethyl methacrylate, 270 parts of IBMA, 50 parts of 3-methacryloyloxypropyltrimethoxysilane and 100 parts of lauryl methacrylate, and azo. A mixture of 50 parts of isobutyronitrile and 450 parts of n-butyl acetate was added dropwise over 5 hours,

Further, by keeping the same temperature for 10 hours, the non-volatile content is 50%, the number average molecular weight is 15,000, and the O generated from the siloxy group is generated.
A polymer solution having an H value of 86 per nonvolatile matter was obtained. Hereinafter, the solution of the vinyl polymer (F) was treated with (F-
Abbreviated as 1).

Reference Example 9 (Same as above) In a reaction vessel similar to that of Reference Example 1, 500 parts of toluene and 50 parts of n-butyl acetate were placed and the temperature inside the vessel was 110 ° C.
The temperature was raised to.

Then, a monomer mixture consisting of 200 parts of styrene, 230 parts of trimethylsiloxyethyl methacrylate, 400 parts of n-butyl methacrylate, 150 parts of n-butyl acrylate, 50 parts of azoisobutyronitrile and A mixture of 450 parts of n-butyl acetate was added dropwise over 5 hours.

Further, by keeping the same temperature for 10 hours, the nonvolatile content was 50%, the number average molecular weight was 16,000, and the O generated from the siloxy group was generated.
A polymer solution having an H value of 70 per nonvolatile matter was obtained. Hereinafter, the solution of the vinyl polymer (F) was treated with (F-
Abbreviated as 2).

Reference Example 10 (Same as above) In a reaction vessel similar to that of Reference Example 1, 500 parts of xylene and 50 parts of n-butyl acetate were placed and the temperature inside the vessel was 110 ° C.
The temperature was raised to.

Next, 200 parts of styrene, "Plaxel FM-1" (commercial name manufactured by the above-mentioned company, a compound in which 1 mol of ε-caprolactone is added to 2-hydroxyethyl methacrylate), and trimethyl A monomer mixture consisting of 290 parts of the reaction product with chlorosilane, 300 parts of n-butyl methacrylate, 150 parts of n-butyl acrylate and 40 parts of acrylic acid, 50 parts of azoisobutyronitrile and acetic acid. A mixture consisting of 500 parts of n-butyl was added dropwise over 5 hours.

Further, by keeping the same temperature for 10 hours, the non-volatile content is 50%, the number average molecular weight is 14,000, and the O generated from the siloxy group is generated.
A polymer solution having an H value of 66 per nonvolatile matter was obtained. Hereinafter, the solution of the vinyl polymer (F) was treated with (F-
Abbreviated as 3).

Reference Example 11 [Preparation Example of Curing Agent (G)] In a reaction vessel similar to that of Reference Example 1, 500 parts of toluene, 50 parts of n-butyl acetate and 100 parts of maleic anhydride were placed, and the temperature inside the vessel was adjusted. Was heated to 110 ° C.

Then, a monomer mixture consisting of 300 parts of styrene, 300 parts of n-butyl methacrylate and 300 parts of n-butyl acrylate, 50 parts of azoisobutyronitrile and tert-butyl peroctoate (t).
ert-butyl peroctate) and 50 parts of acetic acid
-A mixture of 450 parts of butyl was added dropwise over a period of 5 hours.

Further, by holding at the same temperature for 10 hours, a polymer solution having a nonvolatile content of 50% and a number average molecular weight of 5,000 was obtained. Less than,
This solution is abbreviated as a curing agent (G-1).

Reference Examples 12 to 15 (Preparation Examples of Clear Coat Coatings) Each of the vinyl polymers (F-1) to (F-3) obtained in Reference Examples 8 to 11 and a curing agent. (G-1)
And a commercially available polyisocyanate compound, an epoxy compound, etc. were blended separately according to the blending ratio as shown in Table 1, and the diluent solvent [xylene / toluene / n-butyl acetate / methyl ethyl ketone = 30] was added. / 30 /
20/20 (parts by weight)] to obtain various clear coat paints by diluting to a spray viscosity.

[0164]

[Table 1]

<< Footnotes in Table 1 >> (Note 1) "DN-990S" ..... "Barnock
DN-990S "[trade name of polyisocyanate compound manufactured by Dainippon Ink and Chemicals, Inc .; Isocyanate content = 18.0]
%] Abbreviation

(Note 2) GTGE: an abbreviation for glycerin triglycidyl ether, which is a compound having an epoxy equivalent of 145.

(Note 3) TBACL: Abbreviation for tetrabutylammonium chloride

(Note 4) PTSI …………………… p
-Abbreviation for toluene sulfonyl isocyanate

(Note 5) "Tinuvin 900" ... Product name of UV absorber manufactured by Ciba-Geigy Co., Ltd., Switzerland

(Note 6) "Sanol LS292" ... Product name of light stabilizer manufactured by Sankyo Co., Ltd.

[0171]

[Table 2]

Reference Example 16 (Preparation Example of Control Undercoat Paint) Instead of the copolymer (A-1), "Acridic A
-801-P "[trade name of hydroxyl group-containing acrylic resin manufactured by Dainippon Ink and Chemicals, Inc .; nonvolatile content = 50%] except that 90 parts were used in the same manner as in Reference Example 3. , A control undercoat paint was prepared. Hereinafter, this is abbreviated as undercoat paint (RP-1).

Reference Example 17 (Preparation Example of Control Clear Coat Coating) A control sample was prepared in the same manner as in Reference Example 13 except that the composition was changed according to the following mixing ratio.
A clear coat paint was prepared. Hereinafter, this is abbreviated as clear coat paint (RC-1).

"Acridic A-345" 100 parts [Product name of hydroxyl group-containing acrylic resin manufactured by Dainippon Ink and Chemicals, Inc .; nonvolatile content = 55%] "Super Beckamine L-117-60" 40 parts " Nakyur N-5225 "1 copy" Tinubin 900 "1 copy" Sanol LS292 "1 copy

Examples 1 to 4 and Comparative Examples 1 and 2 Using the undercoat paints, base coat paints and clear coat paints obtained in each of the Reference Examples, and paints based on conventional techniques for comparison and control. Table 2 lists the various conditions for coating on the pretreated polypropylene resin coating material and the results of the evaluation / judgment test on the obtained coated plate.

Here, the outline of the evaluation / determination test of various performances shown in Table 2 is as follows.

(1) Gloss Suga Tester Co., Ltd., using a digital variable angle gloss meter.

(2) Vividness Suga Tester Co., Ltd., using a PGD image clarity tester.

(3) Deterioration of the appearance of the coating film after a 0.2 ml·liter droplet of an acid resistant 5% sulfuric acid aqueous solution was placed on the coating surface and left in an atmosphere of 70 ° C. for 30 minutes. The state was visually evaluated and evaluated.

(4) Pencil hardness “UNI” [trade name of pencil manufactured by Mitsubishi Pencil Co., Ltd.] was used, and this was carried out by a conventional method.

(5) Accelerated Weathering Resistance Due panel optical control weather meter was used to visually evaluate the appearance of the coating film after the accelerated exposure test for 1,000 hours.

(6) Durability Adhesion A cutter or a cutter is applied to the coating film after the accelerated weather resistance test described above.
After making a cross-cut with a knife, so-called cellophane tape peeling was performed, and the state of adhesion of the coating film was visually evaluated and evaluated.

[0183]

[Table 3]

[0184]

[Table 4]

<< Footnotes in Table 2 >> The symbols in the table have the following meanings.

⊙: very good ∘, good ∘, bad ×, extremely poor

[0187]

[Table 5]

[0188]

[Table 6]

[0189]

[Table 7]

[0190]

[Table 8]

As described above, the products of the present invention according to Examples 1 to 4 according to the method for forming a coating film according to the present invention are also compared with Comparative Examples 1 and 2 according to the conventional technique. As is apparent, in the case of the coating film forming method of the present invention, it is possible to form a coating film excellent in acid resistance, hardness and coating film appearance, among others,
Therefore, it can be reasonably understood that it is extremely practical, especially for the use of polyolefin-based materials used for automobiles and building materials.

[0192]

As described above in detail, according to the method for forming a coating film of the present invention, it is possible to form a coating film excellent in acid resistance, hardness and appearance of the coating film. Therefore, the present invention can provide a method for forming a coating film, which is extremely highly practical.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B05D 7/24 302 B05D 7/24 302Y 302T 302S 302U 303 303C C09D 5/00 PPF C09D 5/00 PPF 123/28 PFA 123/28 PFA 125/08 PFB 125/08 PFB 167/02 PLB 167/02 PLB 183/07 PMS 183/07 PMS

Claims (5)

[Claims] 1. A base coat is formed by applying a base coat to a polyolefin-based substrate to form a base coat, and then the base coat is coated on the coated surface of the above base coat, and then the base coat is coated on the base coat. In the method for forming a coating film, which comprises coating with a clear coat coating composition, a vinyl group-containing chlorinated polyolefin (A) having a hydroxyl group and a curing agent (reactive with the hydroxyl group) And a vinyl polymer (C) having a hydroxyl group and / or a metallic powder and / or a coloring pigment as a base coat paint, which is used as a base coat paint.
Alternatively, a coating composition containing a polyester resin (D) having a hydroxyl group and a curing agent (E) having reactivity with a hydroxyl group as essential coating film forming components is used as the above-described clear coat coating composition in at least one molecule. A vinyl polymer (F) having two siloxy groups, a curing agent (G) having reactivity with a hydroxyl group formed from the polymer (F), and a siloxy group dissociation promoting catalyst (H), A method for forming a coating film, which comprises using a coating material as an essential coating film forming component. 2. The method according to claim 1, wherein the curing agent (B) having reactivity with a hydroxyl group is at least one compound selected from the group consisting of polyisocyanate compounds and amino resins. 3. The method according to claim 1, wherein the curing agent (E) having reactivity with a hydroxyl group is at least one compound selected from the group consisting of polyisocyanate compounds and amino resins. 4. The vinyl polymer (F) according to claim 1, wherein the vinyl polymer (F) has both a siloxy group which forms a hydroxyl group by hydrolysis and a hydrolyzable silyl group bonded to a carbon atom. the method of. 5. The above-mentioned curing agent (G) having reactivity with a hydroxyl group is at least one compound selected from the group consisting of polyisocyanate compounds, carboxylic acid anhydride group-containing compounds and epoxy compounds. The method according to 1.