JP3242177B2 - Paint resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin for plastic coatings which can be directly applied to hard-to-coat plastics and has greatly improved long-term storage stability, appearance, adhesion, coating film performance, weather resistance, etc. . Here, difficult-to-paint plastics refer to plastics, such as polyolefin resins such as polyethylene and polypropylene, and nylon resins, which have poor adhesion of coating films and are difficult to apply.

[0002]

[Prior art and its problems] In recent years, the application of plastic materials to industrial materials has been expanding more and more, and among them, polyolefin resins such as polyethylene and polypropylene have improved moldability, weight reduction, low cost and recyclability. Characteristically, the amount used for automotive parts, home appliances, etc. is increasing. However, polyolefin resins generally have high crystallinity and low polarity, and thus have the disadvantage that paints, printing inks, adhesives, and the like are difficult to adhere.

[0003] In order to solve the above drawbacks, some pretreatment has conventionally been required. Specifically, physical treatment such as polishing, chemical treatment such as a mixed solution of chromic acid and a solvent, and other methods such as plasma or corona discharge are required. Although treatment and the like can be mentioned, these pretreatment steps have problems that equipment is required, that the treatment cannot be performed uniformly depending on the shape of the object to be coated, and that the cost increases. In addition, various primers having good adhesion to a polyolefin-based substrate have been proposed, but the coating properties such as interlayer adhesion to a top coat and weather resistance are insufficient, and the practicability is poor.

[0004] As a coating resin composition having improved coating properties such as adhesion to a polyolefin material, solvent resistance and hardness, there is a resin composition comprising a chlorinated polyolefin and an acrylic copolymer. However, such a resin composition has the following problems. That is, when the chlorination rate of the chlorinated polyolefin is 50% by weight or more, the compatibility with the acrylic copolymer is improved, but the adhesion of the coating film is reduced. Is good, but the compatibility with the acrylic copolymer is extremely poor, and practical use of both is difficult. From these, it is considered appropriate that the chlorine content of the chlorinated polyolefin is in the range of 25 to 35% by weight. However, since the two components are basically incompatible with each other, there remains a problem in storage stability at a low temperature and the like, and it is difficult for practical use.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a process such as pretreatment or primer coating for a difficult-to-paint plastic such as a polyolefin resin such as polyethylene or polypropylene or a nylon resin, which has a poor adhesion and is difficult to apply. The purpose of the present invention is to provide a coating resin that can be coated without the need for a coating, and that can form a coating film having various excellent properties such as solvent resistance, weather resistance, and adhesion, and has excellent storage stability. I have.

[0006]

Means for Solving the Problems The present invention relates to (A). Chlorinated polyolefin having a chlorine content of 60% by weight or more (a-
1) A chlorinated polyolefin mixture comprising a chlorinated polyolefin (a-2) having a chlorine content of 50% by weight or less [provided that the chlorine content in the chlorinated polyolefin mixture exceeds 50% by weight] 10 (B). It is a coating resin obtained by polymerizing 90 to 10 parts by weight of a vinyl monomer selected from an acrylic monomer (b-1) and another copolymerizable monomer (b-2).

Hereinafter, the present invention will be described in detail.

The chlorinated polyolefin used in the present invention has a chlorine content of more than 50% by weight, preferably 60% by weight or more, and a chlorine content of 50% by weight or less, preferably 60% or more. A mixture with not more than 40% by weight of a chlorinated polyolefin (a-2),
An amount in which the total chlorine content in the mixture exceeds 50% by weight,
Preferably, the chlorinated polyolefin (a-1) and (a-2) are mixed so as to be at least 52% by weight.

A chlorinated polyolefin having a chlorine content of more than 50% by weight has compatibility with an acrylic polymer, weather resistance,
It is a component that improves heat resistance and the like. The chlorinated polyolefin is obtained by chlorinating a polyolefin such as polyethylene or polypropylene by a known method, and various commercially available ones can be used. For example, Super Clone 406 (chlorinated polypropylene manufactured by Sanyo Kokusaku Pulp Co., Ltd.), Super Clon 106L (Sanyo Kokusaku Pulp Co., Ltd.)
Various chlorinated polyolefin resins, such as chlorinated polypropylene (produced by chlorinated polypropylene) and Supercron 506 (chlorinated polyethylene, manufactured by Sanyo Kokusaku Pulp Co., Ltd.).

[0010] Chlorinated polyolefins having a chlorine content of 50% by weight or less are effective components for improving the adhesion to hard-to-paint plastics. The chlorinated polyolefin is obtained by chlorinating a polyolefin such as polyethylene or polypropylene by a known method, and various commercially available products can be used. For example, Supercron L (chlorinated polyolefin manufactured by Sanyo Kokusaku Pulp Co., Ltd.), Supercron 83
2L (chlorinated polyolefin manufactured by Sanyo Kokusaku Pulp Co., Ltd.), Supercron 822 (modified chlorinated polyolefin manufactured by Sanyo Kokusaku Pulp Co., Ltd.), Hard Len 14LLB
Various chlorinated polyolefin resins such as (chlorinated polyolefin manufactured by Toyo Kasei Kogyo Co., Ltd.) and Hardlen B-13 (modified chlorinated polyolefin manufactured by Toyo Kasei Kogyo Co., Ltd.).

Chlorinated polyolefin (a-1) / (a-
The ratio of 2) cannot be unconditionally determined depending on the chlorine content of the chlorinated polyolefin to be used and the requirements of the intended coating film performance, but is, for example, in the range of 50 to 90/50 to 10 (weight ratio). .

The present invention uses the specific amounts of the chlorinated polyolefin (a-1) having a high chlorine content and the chlorinated polyolefin (a-2) having a low chlorine content as described above, and comprises When the chlorine content is more than 50% by weight, it is characterized in that a coating resin having a good balance of long-term storage stability, appearance, adhesion, weather resistance, coating film performance, etc. can be obtained. Things.

Further, an acrylic monomer (b-1) and / or
Or, other vinyl monomers of the copolymerizable monomer (b-2) are basic performances for forming a coating film, that is, coating workability, drying property, hardness, solvent resistance, weather resistance. It is a component effective for improving water resistance and the like. Acrylic monomer (b-
As 1), for example, methyl (meth) acrylate,
Ethyl (meth) acrylate, normal butyl (meth)
Acrylate, isobutyl (meth) acrylate, tertiary butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, 2- Hydroxyethyl (meth) acrylate,
2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, polyethylene Glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, "Placcel FM or F
A "(trade name; caprolactone-added monomer manufactured by Daicel Chemical Co., Ltd.).

Further, other copolymerizable monomers (b-
Examples of 2) include styrene derivatives such as styrene, α-methylstyrene, p-tert-butylstyrene, and vinyltoluene; unsaturated carboxylic acids such as (meth) acrylic acid, itaconic acid, maleic acid, and fumaric acid; Polymerizable unsaturated nitriles such as acrylonitrile, (meth)
Polymerizable amides such as acrylamide, N-methylol (meth) acrylamide, butoxy (meth) acrylamide, unsaturated carboxylic esters such as diethyl maleate, dibutyl maleate, dibutyl fumarate, diethyl itaconate, dibutyl itaconate, vinyl acetate And vinyl esters such as vinyl propionate.

These monomers (b-1) and (b-2)
Can be used alone or in combination of two or more.

Acrylic monomer (b-1) and other copolymerizable monomer (b-2) in vinyl monomer
And (b-1) / (b-2) = 50/10
0 to 50/0 weight ratio. When a monomer having a hydroxyl group in the molecule is used in the component (b-1), the amount is preferably 1 to 45 parts by weight.

The chlorinated polyolefin mixture (A)
And the amount of the vinyl monomer mixture (B) used is (A) /
(B) = 10/90 to 90/10 (weight ratio), and if it is out of this range, it is difficult to obtain the coating resin intended for the present invention.

The polymerization of the vinyl monomer mixture (B) in the presence of the chlorinated polyolefin mixture (A) can be carried out according to a known and commonly used method. For example, using a radical polymerization initiator, 60 to 180 ° C, more preferably 75 to 180 ° C.
A method such as continuing the reaction at a reaction temperature of 100 ° C. for 6 to 12 hours can be employed. Although the polymerization method is not particularly limited,
Solution polymerization is advantageous in terms of productivity and performance. As the organic solvent, aromatic hydrocarbons such as toluene and xylene, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ethyl acetate and esters such as n-butyl acetate are preferably used. It is an aromatic hydrocarbon.

The resin composition for a coating composition of the present invention includes a brightener such as aluminum paste and mica; a coloring agent such as titanium oxide, carbon black and quinacridone; a non-acrylic resin such as an alkyd resin, an epoxy resin and a cellulose resin. An auxiliary additive such as a surface conditioner, an ultraviolet absorber, an antioxidant, a curing catalyst, a pigment sedimentation inhibitor and the like are selected as needed and added by a general compounding method to form a paint.

In the case where the coating resin of the present invention contains a hydroxyl group, a melamine resin or an isocyanate compound is mixed as a crosslinking agent component to improve the coating properties such as solvent resistance, water resistance and weather resistance. Can be achieved.

Specific examples of the melamine resin include n-butylated melamine resin and methylated melamine resin. Further, a specific example of the isocyanate may be a polyisocyanate compound having a free isocyanate group or a blocked isocyanate compound. Specifically, aliphatic diisocyanates such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate, isophorone diisocyanate, methylcyclohexane-2,4- (or 2,6-) diisocyanate, and 4,4'-methylenebis (cyclohexyl isocyanate) Cycloaliphatic diisocyanates such as 1,3 di (isocyanatomethyl) -cyclohexane, tolylene diisocyanate,
Aromatic diisocyanates such as xylene diisocyanate, these organic diisocyanates themselves, or adducts of these organic diisocyanates with excess amounts of polyhydric alcohols, water, etc., polymers of the organic diisocyanates, and isocyanate burettes Body and the like.

The isocyanate compound is NCO / OH = 0.1 / 1 in equivalent ratio to the hydroxyl group-containing component in the coating resin.
It is preferably used in the range of 3/1.

The method for forming a coating film using the coating resin of the present invention is carried out by a known and commonly used method. In general, after dilution with an appropriate organic solvent, spray coating is performed by a spray gun in a dry film thickness range of about 10 to 80 μm.

[0024]

The present invention will be described below with reference to examples. In the description, "parts" and "%" represent parts by weight and% by weight, respectively.

Example 1 A four-necked flask equipped with a cooler, a thermometer, a dropping funnel, and a stirrer was charged with 80 parts of toluene and 14 liters of "Hard Len".
B "(chlorinated polyolefin manufactured by Toyo Kasei Kogyo Co., Ltd., chlorination rate 27%, solid content 30%, toluene solution) 33 parts,
"Supercron HP-205" (chlorinated polypropylene manufactured by Sanyo Kokusaku Pulp Co., Ltd., chlorination rate 67%) 20
And 0.2 parts of benzoyl peroxide, and the internal temperature of the flask was raised to 80 ° C. After stirring for 1 hour, a mixed solution of 30 parts of methyl methacrylate, 15 parts of isobutyl methacrylate, 14 parts of lauryl methacrylate, 10 parts of styrene, 1 part of methacrylic acid, and 3 parts of benzoyl peroxide was added dropwise over 3 hours. After 1 hour and 2 hours, benzoyl peroxide was added to 0.3 parts each.
After 2 hours, 47 parts of toluene were added and the mixture was cooled to obtain a resin for coating (A-1) having a heating residue of 40%.

Examples 2 to 4 In the same manner as in Example 1, polymerization was carried out using the polymerization compositions shown in Table 1 to obtain coating resins (A-2) to (A-4).

Comparative Example 1 A four-necked flask equipped with a cooler, a thermometer, a dropping funnel, and a stirrer was charged with 80 parts of toluene and "14 L of hardlen".
B ”(Chlorinated polyolefin manufactured by Toyo Kasei Kogyo Co., Ltd.
A chlorination ratio of 27%, a solid content of 30%, and a toluene solution (50 parts) were charged, and the internal temperature of the flask was raised to 80 ° C. Next, a mixed solution of 43 parts of methyl methacrylate, 31 parts of isobutyl methacrylate, 10 parts of styrene, 1 part of methacrylic acid, and 3 parts of benzoyl peroxide was dropped over 3 hours. One hour and two hours later, 0.3 parts of benzoyl peroxide was added, and two hours later, toluene was added.
Five parts were added and cooled to obtain a resin composition (A'-1) having a heating residue of 40%.

Comparative Examples 2-3 In the same manner as in Example 1, polymerization was carried out with the polymerization compositions shown in Table 1 to obtain coating resins (A'-2) to (A'-3).

[Performance Test] The coating resins (A-1) to (A-4) obtained in Examples 1 to 4 and the coating resins (A'-1) to (A'-) obtained in Comparative Examples. The storage stability of each of 3) was tested. In addition, paint resins (A-1) to (A-
4) and paint resins (A'-1) to (A ') obtained in Comparative Examples.
Using -3), the components shown in Table 1 were blended and dispersed by a known method to prepare plastic paints. These paints were treated with toluene / xylene / ethyl acetate / n-butyl acetate = 6.
0/25/10/5 thinner for Ford Cup #
After diluting with 15 for 15 seconds, spray coating on a 3 mm thick plate molded from Mitsubishi Yuka's polypropylene resin "Noblen BC-3B" so as to have a dry film thickness of 40μ, and leave for 10 minutes Thereafter, it was dried by heating at 80 ° C. for 30 minutes, and the performance of the obtained coated plate was evaluated. Table 1 shows the results of Examples 1 to 4 and Comparative Examples 1 to 3.

[0030]

[Table 1]

As is clear from Table 1, the coating resin of the present invention has excellent storage stability, and the coating film formed by using the coating resin of the present invention has good appearance, adhesion, weather resistance, and the like.
Excellent gasoline resistance, etc.

The coating film performance in the table was evaluated by the following method.

[Appearance] By visual judgment, evaluation was made in three grades: good, slightly poor, and poor.

[Adhesiveness] The adhesiveness was evaluated by the adherence rate by a cellophane tape peeling test on a square (1 mm interval). The initial and three months later were evaluated respectively.

[Weather resistance] Sunshine WOM, 10
The appearance after 00 hours was visually judged. The evaluation was made in three grades: good, slightly poor, and poor.

[Gasoline resistance] Gauze was impregnated with gasoline, and the appearance after rubbing 16 times was visually determined.
The evaluation was made in three grades: good, slightly poor, and poor.

In Table 1, .largecircle. Indicates good, .DELTA. Indicates slightly defective, and x indicates defective.

[0038]

The coating resin of the present invention having the constitution as described above has excellent storage stability over a long period of time.
Further, the paint for plastics prepared by using the resin for coating has good adhesion to hard-to-paint plastics, and can be directly applied without performing pretreatment or primer coating. And, since it has excellent paint appearance, weather resistance, gasoline resistance, etc. and can form an excellent coating film that does not deteriorate various performances over a long period of time, bumpers, wheel caps, mudguards, lamp housings, etc. It can be used for hard-to-adhere materials such as polyolefins such as automotive exterior parts, automotive interior parts such as instrument panels and console boxes, and home appliances. Therefore,
The coating resin of the present invention greatly contributes to the expansion and development of applications of difficult-to-paint plastics.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-83042 (JP, A) JP-A-58-176208 (JP, A) JP-A-58-183718 (JP, A) JP-A-59-183 138271 (JP, A) JP-A-58-194959 (JP, A) JP-A-61-215666 (JP, A) JP-A-62-41202 (JP, A) (58) Fields investigated (Int. ⁷ , DB name) C08F 289/00 C09D 151/06

Claims (1)

(57) [Claims] (A). A chlorinated polyolefin mixture comprising a chlorinated polyolefin (a-1) having a chlorine content of 60% by weight or more and a chlorinated polyolefin (a-2) having a chlorine content of 50% by weight or less [provided that chlorine in the chlorinated polyolefin mixture is The content is more than 50% by weight.] (B). Vinyl monomer 9 selected from acrylic monomer (b-1) and other copolymerizable monomer (b-2)
A coating resin obtained by polymerizing 0 to 10 parts by weight.