JPS58152024A - Coating material composition for polypropylene resin - Google Patents

Abstract

PURPOSE:The titled coating material composition, consisting of a chlorinated polypropylene resin and dicyclopentadiene type petroleum resin, and capable of giving cured films having improved brightness, adhesive property, adhesive property after moisture resistance tests, solvent resistance, etc. CONSTITUTION:A coating material composition obtained by dissolving a chlorinated polypropylene resin and a dicyclopentadiene type petroleum resin preferably at 100:(30-70) weight ratio in a solvent, e.g. toluene, cyclohexane or trichloroethylene, and kneading the resultant solution in a sand grinding mill, ball mill, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coating composition for polypropylene resin.

Polypropylene resin is one of the plastics whose usage has been rapidly increasing recently, mainly for interior and exterior parts of automobiles (e.g. consoles, bumpers, fender aprons, blow boxes, etc.) due to its workability and price. be.

In the past, plastic was often used as a base material because it was low-priced and easy to color, but now it is being painted to increase added value.

The purpose of painting can be divided into two parts. One of them is.

It is a design effect, and it can be painted to freely set the level of gloss, or it can be finished in multiple colors. Ota.

Another purpose is to improve performance such as chemical resistance, moisture resistance, and solvent resistance through m-packing.

Among plastics, polypropylene resin has high stereoregularity, so it crystallizes easily and has a large self-cohesive force, so it has inferior paint adhesion compared to other resins.

Therefore, the polypropylene resin was coated after being subjected to methods such as acid etching with a chromic acid mixture, surface polishing, plasma treatment, and gas flame treatment.

1. The acid etching method using a chromic acid mixture has many problems in terms of safety, hygiene, and documentation, and the surface polishing method roughens the surface, so mold release agents are applied to the resulting uneven surface. There are drawbacks such as penetration and inhibition of adhesion, and plasma treatment and gas flame treatment methods have the drawback of requiring large equipment costs.

Therefore, recently, a method has been used in which a C% chlorinated polypropylene resin is used as a coating resin, and the coating is applied directly to the polypropylene resin by simply degreasing.

This chlorinated polypropylene resin has good adhesion properties because its solubility in agent I is increased by introducing chlorine into the polypropylene resin, and its polarity is similar to that of polypropylene resin. .

However, when chlorinated polypropylene resin or a paint composition containing pigments is applied to polypropylene resin, the resulting paint film has poor image clarity and poor adhesion after a humidity test. .

In view of the above-mentioned current situation, the present inventors have conducted extensive research and found that the above-mentioned drawbacks can be solved by adding dicyclopentadiene-based petroleum resin to chlorinated polypropylene resin, and have developed the present invention. It is completed.

Specifically, the present invention relates to a coating composition for polypropylene resin comprising a chlorinated polypropylene resin and a dicyclopentadiene petroleum resin.

The chlorinated polypropylene resin used in the present invention has a chlorine content of 20 to 40% by weight;
If the content of chlorine, which may have polar groups such as hydroxyl groups and carbonyl groups, is less than 20% by weight, it has poor solubility in solvents, and if it exceeds 40% by weight, it has adhesive properties (so-called - adhesion) becomes worse.

The synchropentadiene petroleum resin used in the present invention is a polymer obtained by refining the C5 fraction at °C and whose main raw material is nine monomers, and preferably has a molecular weight in the range of 300 to 1000.

If the molecular weight is less than 300, the resulting coating film will have poor adhesion, and if it exceeds 1000, the compatibility with the chlorinated polypropylene resin will be poor.

Examples of commercially available dicyclopentadiene-based petroleum resins include Finton manufactured by Nippon Zeon ■.

The coating composition for polypropylene resin of the present invention can be applied to 100 parts by weight of chlorinated polypropylene resin, [10 to 90 parts by weight per ft of dicyclopentadiene petroleum phase, especially 30 parts by weight]
It is preferable to mix up to 70 parts by weight.

If the amount of dicyclopentadiene petroleum resin is less than 10 parts by weight per 100 parts by weight of chlorinated polypropylene resin, the resulting coating film will have poor adhesion after the image clarity and moisture resistance test. If it exceeds this, the resulting coating film will become brittle.

In order to produce the coating composition for polypropylene resin of the present invention, generally, a chlorinated polypropylene resin and a dicyclopentadiene petroleum resin are mixed together (for example, an aromatic hydrocarbon such as toluene or xylene, or an aromatic hydrocarbon such as cyclohexane). alicyclic hydrocarbons, hagenated hydrocarbons such as dichloromethane, trichloroethylene, etc.), then use a Nando grind mill, attritor, Bo J%/Zulu, four-
It can be easily obtained by kneading with Lumil.

The coating composition for polypropylene resin of the present invention may contain pigments (for example, inorganic pigments such as titanium dioxide, carpump hook, iron oxide, and yellow lead; cyanine green,
Organic pigments such as cyanine blue; extender pigments such as barium sulfate, Merck, mica, etc.), modifiers (e.g. cellulose acetate butyrate resins, epoxy resins, acrylic resins, almide resins, mefusun resins, etc.), additives Agents (for example, pigment dispersants, leveling agents, etc.) can be added.

In order to impart conductivity to the coating composition for polypropylene resin of the present invention, metal powder such as aluminum powder, copper powder, tin powder, conductive carbon black, etc. may be kneaded.

The coating composition for polypropylene resin obtained as described above is usually applied to a polypropylene resin using an 0Ilk coating method (for example, dip coating), spraying is painting, flow coating, etc. By baking for a few minutes, a cured coating film with excellent image clarity, adhesion, adhesion after humidity test, detergent resistance, etc. can be obtained.

Next, the present invention will be explained in more detail by giving examples and comparative examples.
a. In the examples, parts are parts by weight.

Example 1 Chlorinated polypropylene resin (1) 46 parts dicyclopentadiene petroleum resin (2) 2.

Cellulose acetate butyrate am 3# car pump hook 11 xylene
481 [Note] (1) Manufactured by Toyo Kasei Kogyo ■, Birdren 13, chlorine content 26-1 solid content 3
(2) Finton 0302 manufactured by Nippon Zeon Corporation, molecular weight approximately 400] was kneaded for 2 hours using an attritor to obtain a coating composition for polypropylene resin.

The obtained coating composition for polypropylene resin was dip-coated (dry film thickness: 20 μm) on a test plate (polyglopylene resin plate, 2 x 50 x 150 m), and then baked at 100° C. for 20 minutes to obtain a test piece.

Regarding the obtained test piece, temperature, sharpness, lead-silver hardness, adhesion,
Tests such as adhesion after a humidity test, temperature cycle test, and detergent resistance were conducted.

Table 1 shows the test results.

Example 2 Chlorinated polypropylene resin (1) 40 parts Dicyclopentadiene petroleum resin (1) 4゜cell tetraacetate butylene 1118#xylene
38I (Note) (1) A mixture consisting of the above-mentioned Example 1 and (the above-mentioned practical example bottle) was kneaded in a three-roll mill to obtain a coating composition for polypropylene resin.

The obtained coating composition for polypropylene resin was dipped into the test plate of Example 1 to form #19 (dry film thickness 20μ), and then 1
A test piece was obtained by baking at 00°C for 20 minutes.

The obtained test piece was subjected to the same test as in Example 1.

The test results are shown in Table 1.

Example 3 Probile chlorinated polyφ≠-density resin (1) 46 parts dicyclopentadiene petroleum resin (2) 2I carbon black 1# xylene
511 [Note] (l) Above-mentioned Example 1,
(2) Nippon Zeon ■, Finton 1500. Molecular weight 6
00 to 800] was kneaded for 2 hours using an attritor to obtain a coating composition for polypropylene resin.

The obtained polypropylene II@fat coating composition was dip-coated on the test plate of Example 1 (dry film thickness 20-), and then
A test piece was obtained by baking at 80°C for 60 minutes.

The obtained test piece was subjected to the same test as in Example 1.

The test drive results are shown in Table 1.

Comparative example 1 Chlorinated polypropylene resin (1) 46 parts cellulose acetate butylene) 1i1fi a#silcane black 1#xylene
50# [Note: (l) Above-mentioned Example 1] The mixture from above was mixed with an attritor for 2 hours to obtain a ℃ paint composition.

The obtained coating composition was applied to the test plate of Example 1 by dipping (dry film thickness: 20 μm) and then baked at 100° C. for 20 minutes to obtain a test piece.

A test similar to that in Example 1 was conducted on the obtained test piece.

The test results are shown in Table 1.

A mixture consisting of Carbon Black IN Xylene 531 (Note) (1) Example 1 above was mixed with an attritor for 2 hours to obtain a C coating composition.

The obtained coating composition was applied to the test plate of Practical Application 1 by dipping (dry film thickness: 20 μm), and then baked at 80° C. for 60 minutes to obtain a test piece.

The obtained test piece was subjected to the same test as in Example 1 at ℃.

The test results are shown in Table 1.

As is clear from the test results in Table 1 and above, the examples of the present invention have better image clarity, adhesion, adhesion after humidity tests, temperature cycle tests, and detergent resistance than the comparative examples. I can see that it is excellent.

Claims (1)

[Claims] A coating composition for polypropylene resin consisting of a chlorinated polypropylene resin and a dicyclopentadiene petroleum resin.