JPS63191867A - Paint resin composition - Google Patents

Abstract

PURPOSE:To provide a paint resin compsn. which gives a coating film having gloss, alcohol resistance, adhesion to the molded products of untreated polyolefins, etc., by using an acrylic polymer contg. a specified chlorinated polyolefin as main component. CONSTITUTION:10-100wt.% cyclopentyl (meth)acrylate (A) of the formula (wherein R is H or methyl) is mixed with 90-0wt.% vinyl monomer (B) copolymerizable with the component A (e.g., methyl methacrylate) in such a proportion that the total amount is 100wt.%. 95-50pts.wt. resulting monomer mixture is polymerized in the presence of 5-50pts.wt. chlorinated polyolefin having a chlorine content not higher than 50wt.% (e.g., chlorinated polypropylene or chlorinated polyethylene). The resulting acrylic polymer contg. the chlorinated polyolefin is blended with a solvent and additives such as a pigment, a curing agent, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a resin composition for paint. The present invention particularly relates to molded articles, sheets, and films that have not been subjected to any of the various surface treatments for imparting paintability. The present invention relates to a resin composition for paint that can provide a coating film with excellent properties such as adhesion and gloss without performing a primer treatment on a plastic substrate such as untreated polyolefin.

(Prior Art) Recently, attempts have been made to use synthetic resins such as polyolefins in place of metals in automobiles, home appliances, and various other industrial fields for weight reduction, rust prevention, and other purposes. In this case, since the surface of the molded product is usually coated, it is required that the surface of the molded product has good paintability. However, coatings applied to the surfaces of molded articles made of plastics such as polyolefins such as polyethylene and polypropylene are generally inferior in coating film performance such as adhesion, gloss, and resin appearance.

Therefore, many attempts have been proposed to improve coating film performance such as adhesion, gloss, and resin appearance to molded articles made of plastics such as polyolefins. For example, there is a method of improving adhesion by subjecting the surface of these molded products to surface treatments such as degreasing treatment and chromic acid treatment. In addition, after applying a chlorinated polyolefin or a polyolefin modified with maleic acid or its anhydride in a solution or dispersed state to the surface of the molded product and performing a primer treatment,
There are methods of painting with paints that have excellent film performance (for example,
JP-A-58-83042, JP-A-58-1188
09, JP-A-59-30830, etc.).

On the other hand, a composition comprising an epoxy resin, a curing agent for epoxy resin, and a polyolefin or ethylene copolymer having a functional group that reacts with an epoxy group is used as a coating composition that improves the adhesion of a paint film to a polyolefin molded article. It has been proposed (for example, Japanese Patent Application Laid-Open No. 56-72053,
JP-A-56-50971, JP-A-58-1011
(See Publication No. 22, etc.) In addition, compositions made of an acrylic resin having a functional group that reacts with NGO compounds and chlorinated polyolefin, and compositions made of a chlorinated polyolefin-modified acrylic resin having a functional group that reacts with NGO compounds have been proposed (for example, Tokuko Sho 57-14767
Publication No. 17174/1983, Japanese Patent Application Laid-open No. 17174/1983
(See Publication No. 27968, etc.). Furthermore, acrylic-modified chlorinated polyolefin resin compositions comprising an acrylic resin and a chlorinated polyolefin have been proposed (for example, JP-A-58-183718, JP-A-58-194959).
(See Japanese Patent Laid-Open No. 59-30830, etc.).

(Problems to be Solved by the Invention) However, the surface treatment method described above cannot sufficiently improve coating film performance such as adhesion. In addition, with the method of applying primer treatment described above, a coating film with excellent adhesion may be obtained depending on the type of chlorinated polyolefin or modified polyolefin, but the operation of applying the primer is complicated, and the primer treatment The disadvantages are that it requires a lot of time and effort, and that the cost of painting increases. Furthermore, it cannot be said that the above-mentioned epoxy compositions and urethane compositions have sufficient adhesion to plastic molded articles such as polyolefins. Also,
Since it is a two-component type, it takes time to mix it, and furthermore, since it is a curing type, there are disadvantages such as pot life and workability must be taken into consideration.

In addition, the adhesion of the acrylic-modified chlorinated polyolefin composition is affected by the amount of chlorinated polyolefin,
If an attempt is made to obtain sufficient adhesion, the appearance, gloss, and other performance of the resin will deteriorate. Therefore.

The drawback is that it is impossible to adjust properties such as adhesion, resin appearance, and gloss.

The present invention solves the above-mentioned drawbacks and provides a coating film that can be applied directly to the surface of a molded product without surface treatment, and has excellent properties such as adhesion, gloss, and alcohol resistance. The purpose is to provide a resulting resin composition.

(Means for Solving the Problems) The present invention provides that (a) general formula (I): [in the formula R represents hydrogen or a methyl group] and (b) 0 to 90% by weight of another vinyl monomer copolymerizable with component (a).

A paint comprising a chlorinated polyolefin-containing acrylic polymer obtained by polymerizing 95 to 50 parts by weight of monomers in which the total amount of components (a) and (b) is 100% by weight. The present invention relates to a resin composition for use.

The above-mentioned chlorinated polyolefins include polyethylene resins, polypropylene resins, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, etc. having a chlorine content of 50% by weight or less. When the chlorine content exceeds 50% by weight,
Adhesion to polyolefin base materials decreases. Therefore, the chlorine content should be determined while taking various coating film performances into consideration, and is preferably 15 to 35% by weight.

Examples of the monomer represented by the general formula (1) include cyclopentyl methacrylate and cyclopentyl acrylate.

Regarding the amount of the monomer that is component (a), if it is less than 10% by weight based on the total amount of monomers, water resistance, gloss,
Resin appearance deteriorates. Therefore, 1 for the total amount of monomers
It is used in an amount of 0 to 100% by weight, preferably 20 to 100% by weight.

Component (b) is preferably an alkyl ester of acrylic acid or methacrylic acid other than the above-mentioned component (a), such as methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, and acrylic acid. Acrylic acid alkyl esters such as lauryl acid, cyclohexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate,
Examples include methacrylic acid alkyl esters such as lauryl methacrylate and cyclohexyl methacrylate, and (b)
Ingredients further include hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate, aminomethyl methacrylate, N-methylaminomethyl methacrylate, and N, N methacrylate.
- Aminoalkyl methacrylates such as diethylaminoethyl, aminomethyl acrylate, N-methylaminomethyl acrylate, aminoalkyl acrylates such as N-acrylate, N-diethylaminoethyl, glycidyl methacrylate, glycidyl acrylate, methacrylic acid, acrylic Acids, styrenic monomers such as methacrylamide, acrylamide, styrene, vinyltoluene, α-methylstyrene, vinyl derivatives such as vinyl chloride, vinylidene chloride, vinyl acetate, isopropyl acetate, unsaturated monomers such as maleic acid, fumaric acid, etc. Examples include basic acids, acid anhydrides thereof, monoesters thereof such as monomethyl ester and monoethyl ester, and diesters such as dimethyl ester and diethyl ester thereof. In addition, here, alkyl also includes the meaning of cycloalkyl, among these, hydroxyl group.

A polymerizable monomer having a functional group such as a glycidyl group, a carboxyl group, an amide group, or an amino group is used in an amount of 0 to 5% by weight based on the total amount of the polymerizable monomers (a) and (b). It is preferable that the amount of these is too large, and the adhesion to the polyolefin tends to decrease.

In the present invention, the weight ratio of the chlorinated polyolefin and the polymerizable monomer mixture is 5/95 to 50 in terms of the former/latter.
It is blended at a ratio of 150%. This weight ratio is 5
If it exceeds 0150, solvent resistance and hardness will decrease. Moreover, when the weight ratio is less than 5795, the adhesion to the polyolefin base material decreases. This weight ratio is 10/
It is preferable that it is 90-35/65.

The polymerizable monomer blend in the presence of the chlorinated polyolefin is carried out by a known radical polymerization method, and the method is not particularly limited.
Solution polymerization is carried out at 30°C.

In this case, aromatic solvents such as toluene and xylene, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate and butyl acetate, and chlorine solvents such as carbon tetrachloride are used as organic solvents. Ru. Further, in the polymerization, organic peroxides such as benzoyl peroxide, dicumyl peroxide, and dibutyl peroxide, and azobis-based compounds such as azobisisobutyronitrile and azobisvaleronitrile are used as polymerization initiators. It is preferable to use the polymerizable monomer mixture by mixing the monomers to be blended in advance, but they may be added separately during polymerization, or the mixture may be added in portions.

The chlorinated polyolefin-containing polymer thus obtained is dissolved in a suitable organic solvent to form a resin composition for coating. As the organic solvent, those exemplified as the organic solvent for solution polymerization can be used.

Therefore, when a chlorinated polyolefin-containing polymer is synthesized by solution polymerization, a coating resin composition can be obtained as soon as the polymerization is completed.

Furthermore, the composition of the present invention may contain inorganic pigments such as titanium white, cadmium yellow, and carbon black, organic pigments such as phthalocyanine pigments and azo pigments, and other additives, and may optionally contain a curing agent. be able to.

The resin composition for paint according to the present invention can be applied by spray coating, roll coater coating, etc., and the amount of organic solvent is appropriately determined so as to have an appropriate solid content suitable for each coating method. For painting, use Ford Cup #4
It is preferable to adjust the viscosity to 12 to 20 seconds at (25°C).

The composition of the present invention thus obtained can be used as a top coat, enamel paint, primer, etc. for polyolefin materials such as polyolefin molded articles, sheets, and films, or polyolefin substrates.

(Example) Next, Examples of the present invention will be shown. Hereinafter, parts and % refer to parts by weight and weight %.

Examples 1 to 4 and Comparative Examples 1 to 4 A 15% solid toluene solution of chlorinated polypropylene (chlorine content 26%) with the solid content shown in Table 1, chlorinated polyethylene (chlorine content 26%) with the solid content shown in Table 1 Content rate 26%)
A toluene solution with a solid content of 20% and toluene were placed in a reactor equipped with a stirrer and a cooler so that the total amount was 50 parts by weight, and heated to 100°C. A mixture in which 1 part of benzoyl peroxide was uniformly dissolved was added dropwise over 3 hours, and the mixture was reacted at the same temperature for 5 hours.

After cooling, toluene was added to about 41-42% solids. Next, toluene/butyl cellosolve is 95
12 in Ford Cup #4 with a mixed solvent of 75 (weight ratio)
The viscosity was adjusted to ~13 seconds. Thereafter, the obtained coating resin composition was spray-coated onto an unmodified polypropylene molded plate, heated at 60° C. for 30 minutes, and then allowed to stand at room temperature for 24 hours. The thickness of the coating film was set to 3 μs. Adhesion, hardness, gloss, and alcohol resistance were tested using the obtained coated molded board.

The test method is as follows.

Adhesion: Based on JIS K 5400 cross-cut Sellotape test method.

Luminosity: Measured using 60 degree specular reflectance.

Alcohol resistance: Measured by rubbing test with a load of 1 kg, and the results are shown with the symbols below.

0 150 times or more 0 100-149 X 99 times or less The test results are shown in Table 1.

(The following is a blank space) (Effects of the Invention) The resin composition for paint according to the present invention has excellent adhesion to plastics such as untreated polyolefin, gloss, and alcohol resistance in a well-balanced manner.

(, Pa Ri-8

Claims (1)

[Claims] 1. In the presence of 5 to 50 parts by weight of a chlorinated polyolefin resin with a chlorine content of 50% by weight or less, (a) General formula: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [In the formula, R represents hydrogen or a methyl group] and (b) 0 to 90% by weight of another vinyl monomer copolymerizable with the above component (a). A coating resin containing a chlorinated polyolefin-containing acrylic polymer obtained by polymerizing 95 to 50 parts by weight of monomers in which the total amount of components a) and (b) is 100% by weight. Composition.