JPH0641477A - Stabilizer for thermosetting synthetic resin coating composition - Google Patents

Abstract

PURPOSE:To improve the light resistance and prevent the coloration of a coating film formed from a thermosetting synthetic resin coating compsn. by com pounding the compsn. with a specific 4-hydroxybenzoic ester and a specific hindered amine. CONSTITUTION:100 pts.wt. thermosetting synthetic resin coating compsn. is compounded with 0.01-5 pts.wt. 4-hydroxybenzoic ester of formula I (wherein R1 is a lower alkyl group; and R2 is an optionally substd. alkyl or aryl group) and 0.01-5 pts.wt. hindered amine of formula II (wherein R3 is an alkyl, acyl, or alkoxy; R4 is an alkyl; R5 is a residue formed by removing two hydroxyl groups from a dihydric alcohol; A is a residue formed by removing 1-4 carboxyl groups from a tetracarboxylic acid; n is 1-4; m is 0-3; and p is 0 or 1).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stabilizer for thermosetting synthetic resin coatings, and more particularly to a stabilizer for thermosetting synthetic resin coatings comprising a specific phenol compound and a specific hindered amine compound.

[0002]

2. Description of the Related Art Conventionally, paints used outdoors, such as paints for automobile exteriors, have long-term chemical resistance, solvent resistance, and physical performance. The light resistance of is required. In particular, due to the recent social demand for resource saving, the demand for light resistance has become more advanced. For example, in the case of passenger cars, a coating film guarantee of several years or more has been required.

The polymer compound in the paint forming the coating film is
It deteriorates under the action of light, causing cracks, lowering of gloss and discoloration, and significantly impairing the appearance of the coating film. In addition, in a two-coat, one-bake finish coating film, delamination may occur between the base coat layer and the top coat layer.

In order to solve the above-mentioned drawbacks of the paint, various ultraviolet absorbers are used as light stabilizers. However, these UV absorbers are not fully satisfactory. Therefore, for example, JP-B-1-14263 and JP-B-2-389 propose a stabilizer for a lacquer comprising a hindered amine compound and a benzopheno-type, oxalanilide-type or benzotriazole-type UV absorber. However, the effect was not yet satisfactory in practice.

[0005]

Means for Solving the Problems As a result of intensive studies made by the present inventors in view of the present situation, as a result, a stabilizer for a thermosetting synthetic resin coating composed of a specific phenol compound and a specific hindered amine compound has improved light resistance. The present invention has been completed by finding out that there is an improvement and there is almost no coloring on the coating film.

That is, the present invention provides a 4-hydroxybenzoic acid ester compound represented by the general formula (I) of the following [Chemical formula 3] (same as [Chemical formula 1]) and [Chemical formula 4] (Chemical formula 2) And a hindered amine compound represented by the general formula (II)).

[0007]

[Chemical 3]

[0008]

[Chemical 4]

The stabilizer of the present invention will be described in detail below.
In the above general formula (I) representing the 4-hydroxybenzoic acid ester compound which is a component of the stabilizer of the present invention, the lower alkyl group represented by R ₁ is an alkyl group having 1 to 4 carbon atoms, which is methyl. And groups such as ethyl, propyl, isopropyl, butyl, sec-butyl and tert-butyl. Further, the alkyl group which may have a substituent represented by R ₂ is preferably an alkyl group having 1 to 18 carbon atoms, methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl. , Amyl, isoamyl, hexyl, heptyl, octyl, isooctyl, 2-ethylhexyl, tertiary octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, 12
-Hydroxystearyl, oleyl, cyclohexyl,
Benzyl, phenylethyl, 2-hydroxyethyl,
2,3-epoxypropyl, dimethylaminopropyl,
Examples include groups such as methoxyethyl. The aryl group represented by R ₂ includes phenyl, 4-methylphenyl, 4-octylphenyl, 4-nonylphenyl, 2,
4-di-tert-butylphenyl, 2,4-di-tert-amylphenyl, 2,4-di-tert-octylphenyl, 2-tert-butyl-4-tert-octylphenyl and the like can be mentioned.

Therefore, 4- represented by the above general formula (I)
Examples of the hydroxybenzoic acid ester compound (phenol compound) include the following compounds (compounds 5 to 8) (compounds P-1 to P-4).

[0011]

[Chemical 5]

[0012]

[Chemical 6]

[0013]

[Chemical 7]

[0014]

[Chemical 8]

The amount of the above phenol compound added to the thermosetting synthetic resin paint is preferably 0.01 to 5 parts by weight, more preferably 0.01 to 3 parts by weight, based on 100 parts by weight of the resin component in the paint. Is.

In the general formula (II) representing the hindered amine compound which is a component of the stabilizer of the present invention, the alkyl group represented by R ₃ is preferably an alkyl group having 1 to 12 carbon atoms, such as methyl or ethyl. Groups such as propyl, isopropyl, butyl, secondary butyl, tertiary butyl, amyl, isoamyl, hexyl, heptyl, octyl, isooctyl, 2-ethylhexyl, tertiary octyl, nonyl, decyl, dodecyl, benzyl, and the like. _The alkoxy group represented by ₃ is preferably an alkoxy group having 1 to 12 carbon atoms, methoxyl, ethoxyl, propoxyl, isopropoxyl, butoxyl, secondary butoxyl, tertiary butoxyl, amyloxyl, hexoxyl, heptoxyl, octoxyl. , Isooctoxyl, 2-ethylhexoxyl, Three Okutokishiru, Nonirokishiru,
Examples thereof include groups such as decyloxyl, undecyloxyl, and dodecyloxyl. As the acyl group represented by R ₃ , an acyl group having 1 to 8 carbon atoms is preferable, and groups such as formyl, acetyl, propionyl and butyroyl can be mentioned. _Four
The alkyl group represented by is preferably an alkyl group having 1 to 30 carbon atoms, methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, amyl, isoamyl, hexyl, heptyl, octyl, isooctyl. , 2-ethylhexyl, tertiary octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl,
Octadecyl, eicosyl, henicosyl, tetracosyl, triacontyl, 12-hydroxystearyl, oleyl, cyclohexyl, benzyl, phenylethyl,
Groups such as 2-hydroxyethyl, 2,3-epoxypropyl, dimethylaminopropyl and methoxyethyl are mentioned, and dihydric alcohols giving the residue represented by R ₅ include ethylene glycol, propylene glycol and neopentyl glycol. , 1,2-butyldiglycol,
1,4-butyldiglycol, 1,6-hexanediol, 1,10-decanediol, diethylene glycol, triethylene glycol, 3,9-bis (1,1-
Dimethyl-2-hydroxyethyl) -2,4,8,10
-Tetraspiro [5.5] undecane and the like,
Further, as the carboxylic acid giving the residue represented by A,
For example, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, neodecanoic acid, 2-ethylhexylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, Isostearic acid, stearic acid, 12-hydroxystearic acid, behenic acid, montanic acid, elaidic acid, oleic acid, linoleic acid, linolenic acid, thioglycolic acid, mercaptopropionic acid, octylmercaptopropionic acid, benzoic acid, monochlorobenzoic acid, p-
Tert-butylbenzoic acid, dimethylhydroxybenzoic acid,
One of 3,5-di-tert-butyl-4-hydroxybenzoic acid, toluic acid, dimethylbenzoic acid, ethylbenzoic acid, cuminic acid, n-propylbenzoic acid, acetoxybenzoic acid, salicylic acid, p-tert-octylsalicylic acid, etc. Carboxylic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, citraconic acid, metaconic acid, itaconic acid, aconitic acid, thio Divalent carboxylic acids such as dipropionic acid, phthalic acid, isophthalic acid, terephthalic acid, oxyphthalic acid, chlorophthalic acid, tricarballylic acid, citric acid, butanetricarboxylic acid, butenetricarboxylic acid, butanetetracarboxylic acid, hemimellitic acid, Trivalent or tetravalent carboxylic acid such as trimellitic acid, melophanoic acid, and pyromellitic acid. Bonn acid, and the like.

Therefore, as the hindered amine compound represented by the above general formula (II), for example, the following [formula 9]
To the compounds of [Chemical Formula 16] (Compounds H-1 to H-8).

[0018]

[Chemical 9]

[0019]

[Chemical 10]

[0020]

[Chemical 11]

[0021]

[Chemical 12]

[0022]

[Chemical 13]

[0023]

[Chemical 14]

[0024]

[Chemical 15]

[0025]

[Chemical 16]

The amount of the above-mentioned hindered amine compound added to the thermosetting synthetic resin coating material is 100 resin components in the coating material.
The amount is preferably 0.01 to 5 parts by weight, more preferably 0.01 to 3 parts by weight, based on parts by weight.

The thermosetting synthetic resin coating material to be stabilized by the stabilizer of the present invention includes, for example, a thermosetting resin coating material using an acrylic resin, an alkyd resin or an unsaturated polyester resin as a substrate. May optionally be modified with melamine / formaldehyde resin, epoxy resin or polyisocyanate resin.

The stabilizer of the present invention comprises the above compound and
2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-
2-Hydroxybenzophenones such as octoxybenzophenone and 5,5′-methylenebis (2-hydroxy-4-methoxybenzophenone); 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2
-(2'-hydroxy-3 ', 5'-di-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-
3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- ( 2'-hydroxy-5'-tertiary octylphenyl) benzotriazole, 2- (2'-hydroxy-3'.5'-dicumylphenyl) benzotriazole, 2,2'-methylenebis (4-tertiary octyl-
2- (2'- such as 6-benzotriazolyl) phenol
Hydroxyphenyl) benzotriazoles; 2-ethyl-2'-ethoxyoxanilide, 2-ethoxy-4 '
-Substituted oxanilides such as dodecyl oxanilide; ethyl-α-cyano-β, β-diphenyl acrylate, cyanoacrylates such as methyl-2-cyano-3-methyl-3- (p-methoxyphenyl) acrylate It can be used in combination with an ultraviolet absorber.

In addition, if necessary, the stabilizer of the present invention is
Used with conventional additives for paints, such as other light stabilizers, antioxidants, plasticizers, flow modifiers, accelerators, thickeners, dispersants, pigments, dyes, antistatic agents, etc. be able to.

The resin coating composition in which the stabilizer of the present invention can be used may be a solvent type, a liquid solventless type, a water-soluble type, a water-dispersed type, a powder, or the like, and is appropriately selected according to the purpose and application. be able to.

[0031]

EXAMPLES Next, the present invention will be specifically described by way of examples. However, the invention is not limited by these examples.

Example 1 In this example, the effect of the stabilizer of the present invention was observed on a two-layer metallic luster paint comprising a base coat paint containing a metal pigment and a top coat paint.

A) Base coat paint 100 g of methyl methacrylate, 66 g of n-butyl acrylate, 30 g of 2-hydroxyethyl methacrylate,
4 g of methacrylic acid, 80 g of xylene and 20 g of n-butanol were taken, and 2 g of azobisisobutyronitrile, 0.5 g of dodecyl mercaptan, 80 g of xylene and 20 g of n-butanol were stirred and heated at 110 ° C.
Was added dropwise over 3 hours. Then, the mixture was stirred at the same temperature for 2 hours to prepare an acrylic resin solution having a resin solid content of 50%.

12 parts by weight of the above acrylic resin solution, butoxylated methylol melamine (manufactured by Mitsui Toatsu Co .; U-Van 20S)
E60; resin solid content 60%) 2.5 parts by weight, cellulose acetate butyrate resin (20% butyl acetate solution) 5
0 parts by weight, aluminum pigment (manufactured by Toyo Aluminum Co., Ltd .;
Alpaste 1123N) 5.5 parts by weight, xylene 10
By weight, 20 parts by weight of butyl acetate and 0.2 parts by weight of copper phthalocyanine blue were mixed to obtain a base coat paint.

B) Topcoat paint 100 g of methyl methacrylate, 66 g of -n-butyl acrylate, 30 g of 2-hydroxyethyl methacrylate,
Methacrylic acid 4 g, compound H-2 (exemplified compound of [Chemical Formula 10]) 1.0 g, test compound (see [Table 1]) 2
g, 80 g of xylene and 20 g of n-butanol, and a solution consisting of 2 g of azobisisobutyronitrile, 0.5 g of dodecyl mercaptan, 80 g of xylene and 20 g of n-butanol was added dropwise thereto over 3 hours while stirring with heating at 110 ° C. did. Then, the mixture was stirred at the same temperature for 2 hours to prepare an acrylic resin solution having a resin solid content of 50%.

48 parts by weight of the acrylic resin solution, 10 parts by weight of butoxylated methylol melamine, 10 parts by weight of xylene and 4 parts by weight of butyl glycol acetate were mixed to obtain a top coat paint.

Spray the base coat paint on a primer-treated steel plate to a dry film thickness of 20 μ, and
After being left to dry for 0 minutes, the top coat paint was sprayed so that the dry film thickness was 30 μm. After leaving for 15 minutes, 1
A test piece was prepared by baking at 40 ° C. for 30 minutes.

This test piece was placed in a weatherometer and the time until the cracking of the coating film was generated was measured.

The results are shown in Table 1 below.

[0040]

[Table 1]

Example 2 Palm oil-modified alkyd resin (manufactured by Dainippon Ink; Betucozol 1323; resin solid content 60) as a top coat paint
%) 70 parts by weight, butoxylated methylol melamine (Uban 20SE60) 30 parts by weight, compound H-2 (exemplified compound of [Chemical Formula 10]) 0.5 part by weight and test compound (see [Table 2]) 1.0. A test piece was prepared in the same manner as in Example 1 except that the parts by weight of the mixture were used.

This test piece was put in a weatherometer and the time until the crack of the coating film was generated was measured.

The results are shown in Table 2 below.

[0044]

[Table 2]

Example 3 20 g of styrene, 20 g of methyl methacrylate, 20 g of butyl acrylate, 2-ethylhexyl methacrylate 2
2 g, 15 g of 2-hydroxyethyl methacrylate, 3 g of methacrylic acid, 3 g of compound P-1 (exemplified compound of [Chemical Formula 5]) and 1.5 g of test compound (see [Table 3]).
Was copolymerized with azobisbutyronitrile in xylene to prepare an acrylic resin solution having a solid content of 50%.

15 parts by weight of the acrylic resin solution, 3 parts by weight of butoxylated methylol melamine (Uban 20SE60), epoxy resin (Asahi Denka; ADEKA RESIN EP-1)
3) 2 parts by weight, aluminum pigment (Alpaste 112
3 N) 6 parts by weight and 10 parts by weight of xylene were mixed well to prepare a paint.

A test piece was prepared by spraying the above-mentioned paint on a primer-treated steel sheet so that the dry coating film had a thickness of 40 μm, leaving it for 10 minutes, and baking it at 140 ° C. for 30 minutes.

This test piece was placed in a weatherometer and 3
The gloss (60 degree gloss) after irradiation for 000 hours was measured.

The results are shown in Table 3 below.

[0050]

[Table 3]

Example 4 Polyester resin (manufactured by Bayer; L / Ue6108) 7
5 parts by weight, blocked polyisocyanate (manufactured by Bayer; L / Ue6109) 25 parts by weight, titanium dioxide 30
Parts by weight, 1 part by weight of phthalocyanine blue, compound P-1
0.75 parts by weight of the exemplified compound of [Chemical Formula 5] and 1.5 parts by weight of a test compound (see [Table 4]) were added to toluene 7
0 parts by weight, 80 parts by weight of xylene and 100 parts of butyl acetate
It was well dispersed in a mixed solvent of parts by weight to prepare a paint.

The above paint was sprayed onto a primer-treated steel sheet to a dry film thickness of 30 μ, and after standing for 15 minutes,
A test piece was prepared by baking at 180 ° C. for 30 minutes.

This test piece was put in a weatherometer, and 1
The gloss after irradiation for 000 hours was measured.

The results are shown in Table 4 below.

[0055]

[Table 4]

As is clear from the results shown in [Table 1] to [Table 4] above, when the phenol compound or the specific hindered amine compound, which is a component of the stabilizer of the present invention, is added to the coating alone, However, the effect of improving the light resistance is small, and the performance is insufficient even when a phenol compound and a hindered amine compound other than the present invention are used in combination.

On the other hand, when the stabilizer of the present invention is added to the coating composition, an unpredictable synergistic effect is observed when used alone.

[0058]

INDUSTRIAL APPLICABILITY The stabilizer for thermosetting synthetic resin coating material of the present invention can provide a thermosetting synthetic resin coating material excellent in light resistance by adding the stabilizer to the coating material.

Claims (1)

[Claims] 1. A compound represented by the following general formula (I)
-A stabilizer for a thermosetting synthetic resin coating, which comprises a hydroxybenzoic acid ester compound and a hindered amine compound represented by the general formula (II) of [Chemical Formula 2]. [Chemical 1] [Chemical 2]