JPH032196B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a new and useful resin composition for coatings, which is intended for use on various untreated films, sheets, molded products, etc. that are to be coated with paintability. It is an object of the present invention to provide a resin composition that has a function as a primer for so-called untreated polyolefin base materials, can be applied in a one-coat manner, and has good adhesion and solvent resistance. Conventional paints made of alkyd, acrylic, and epoxy resins have little adhesion to various molded products made of crystalline polyolefins, which have low polarity, and therefore it is difficult to apply coatings to these polyolefin-based substrates. As a primer,
In particular, it has been proposed to use atactic polypropylene modified with maleic anhydride or ethylene-propylene copolymer modified with maleic anhydride, but both of these have good adhesion to such substrates. However, it has poor interlayer adhesion with the top coat, and when used as a clear paint, the paint film may become cloudy or cloudy.
On the other hand, when applied as an enamel paint containing pigments, there were problems in that the pigment dispersion was extremely poor and the paint lacked stability. Also, a method is known in which chlorinated polyolefin itself is used as a primer and acrylic resin is applied to the top coat, but this method deteriorates interlayer adhesion with the top coat, solvent resistance, and long-term durable adhesion. There is a drawback that it does. Furthermore, although it is known to use chlorinated polyolefin itself as a top coat, this method is also impractical because the hardness, solvent resistance, and weather resistance of the coating film are significantly deteriorated. Coating compositions that maintain long-term adhesion to polyolefin substrates or interlayer adhesion with top coats and also have improved coating performance such as solvent resistance and hardness include chlorinated polyolefins and acrylics. Although resin compositions consisting of acrylic copolymers and chlorinated polyolefins are effective, compositions formed by blending such acrylic copolymers with chlorinated polyolefins include the following problems. In other words, when the chlorination rate is 50% by weight or more, although the compatibility between the chlorinated polyolefin and the acrylic copolymer improves, the adhesion and solvent resistance of the formed coating film decreases, making it difficult to put it into practical use. It can be said that it is really difficult. On the other hand, to improve adhesion, the chlorination rate must be 50% or less, e.g.
This is possible by using a chlorinated polyolefin with a chlorination rate of around 35%, but on the other hand, it lacks compatibility with the acrylic copolymer and the stability of the paint becomes significantly worse. However, it is extremely difficult to put it into practical use. However, as a result of intensive research by the present inventors in order to further improve the compatibility between a specific chlorinated polyolefin and an acrylic (co)polymer, and at the same time improve the adhesion to the polyolefin base material, we found that (meth) ) Chlorinated polyolefin obtained by polymerizing a vinyl monomer containing acrylic acid ester as an essential component with cyclized rubber and chlorinated polyolefin with a specific chlorination rate of 50% or less. A specific film-forming polymer binder, which is an acrylic or vinyl-modified copolymer in which a vinyl monomer as a grafting component is grafted onto a cyclized rubber backbone polymer, has extremely high compatibility and The present invention was completed based on the discovery that the adhesion properties were also good. That is, the present invention comprises 50 to 100% by weight of (meth)acrylic acid ester (a-1) and these (a-1)
Other vinyl monomer (a-2) copolymerizable with 0
Vinyl monomer mixture (A) consisting of ~50% by weight
In the presence of chlorinated polyolefin (B) and cyclized rubber (C) with a chlorination rate of 50% or less, for these chlorinated polyolefin (B) and cyclized rubber (C),
The above three components (A), (B) and (C) are each
Solid content: (A)/[(A)+(B)+(C)]=10~85% by weight, (B)/[(A)+(B)+(C)]=89~5% by weight %,and
(C)/[(A)+(B)+(C)]=1 to 10% by weight, and contains a graft copolymer obtained by polymerization as an essential film-forming polymer binder. The present invention provides a resin composition for coating material comprising the following steps. Here, the above-mentioned cyclized rubber (C) is obtained by reacting phenol, phosphoric acid, and a rubber component, and includes, for example, "CK-514" (manufactured by Hoechst, West Germany). In addition, the above-mentioned chlorinated polyolefin (B) has a chlorine content of 50% by weight or less, preferably 15% by weight or less.
This refers to polyolefins containing up to 40% by weight, and typical polyolefins include ethylene, propylene, butene-1,3-methyl-
Homopolymers or copolymers of α-olefins such as 1-pentene, 3-methyl-1-heptene, ethylene-vinyl acetate copolymers, ethylene-vinyl acetate copolymers, etc.
There are copolymers of α-olefin and other vinyl monomers such as butadiene copolymer, ethylene-acrylic acid ester copolymer, etc., and therefore, typical examples of the chlorinated polyolefin (B) include Examples include chlorinated polyethylene, chlorinated polypropylene, chlorinated ethylene-propylene copolymer, or chlorinated ethylene-vinyl acetate copolymer. Regarding the chlorination rate of the chlorinated polyolefin (B), if the chlorination rate exceeds 50%, the adhesion to the polyolefin base material decreases, so the determination of the chlorination rate is based on such adhesion. This should be done while taking into consideration various coating properties such as flexibility and hardness, preferably from 15 to 40%, and in this way a resin composition with the most balanced coating properties can be obtained. can get. On the other hand, typical examples of the above-mentioned (meth)acrylic ester (a-1) include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, and (meth)acrylic acid. Isobutyl, hexyl (meth)acrylate, octyl (meth)acrylate, (meth)acrylic acid 2
- Ethylhexyl, lauryl (meth)acrylate, cyclohexyl (meth)acrylate, etc. may be used, but these may be used alone or in combination of two or more. There is no problem in using some monomers containing functional groups, such as, but copolymerization of such functional group-containing monomers is particularly recommended for improving solvent resistance and pigment dispersibility. Ru. In addition, the (meth)acrylic acid ester (a-
1) and other vinyl monomers (a-
Typical examples of 2) include styrene or diesters of unsaturated dibasic acids such as butyl fumarate, dimethyl malate or dibutyl itaconate, and these monomers can be used depending on the desired coating performance. However, the amount used should be 50% by weight or less of the total amount of monomers. If the amount of the (meth)acrylic acid ester (a-1) used is less than 50% by weight, the hardness and solvent resistance of the resulting coating film will be insufficient. The amount of acid ester (a-1) used should be 50% by weight or more, preferably 50 to 90% by weight. Therefore, when polymerizing the vinyl monomer mixture (A) with the chlorinated polyolefin (B) and cyclized rubber (C), these ((A), (B) and ( C)
The three components are used in a solid content of (A) in a range of 10 to 85% by weight, (B) in a range of 89 to 5% by weight, and (C) in a range of 1 to 10% by weight. The preferred range is 49 to 80% by weight of (A), 50 to 12% by weight of (B), and 1 to 8% by weight of (C). Here, if the vinyl monomer content is less than 10% by weight, the hardness and solvent resistance of the coating film will decrease;
If it exceeds % by weight, it is not preferable because the adhesion to the polyolefin material or base material decreases.
In addition, if the chlorinated polyolefin content is less than 5% by weight, this adhesion will decrease;
If it exceeds 10% by weight, it is undesirable because the weather resistance will decrease, and if it is less than 1% by weight, the solvent (gasoline) resistance will decrease, and if it exceeds 10% by weight, it will be undesirable. Both are undesirable because the weather resistance of the coating film decreases. In addition, by such polymerization, the vinyl monomer mixture (A) component mainly composed of (meth)acrylic acid ester as described above is grafted onto both the chlorinated polyolefin (B) and cyclized rubber (C) components. The result is a mixture of modified chlorinated polyolefin and modified cyclized rubber with good compatibility. Alternatively, solution polymerization is preferably carried out using a radical-generating polymerization initiator such as azobisisobutyronitrile. Thus, the composition of the present invention contains acrylic ester and/or methacrylic ester (a-1) in chlorinated polyolefin (B) and cyclized rubber (C).
are essential monomer components, or these (a-
The other vinyl monomer (a-2) that is copolymerizable with the monomer 1) is also added to the total amount of the total monomer mixture (A).
50% by weight or less, and if necessary, the above-mentioned functional group-containing monomers are also used in combination in an amount of 20% by weight or less of the total amount of the monomer mixture (A), and If necessary, the above-mentioned functional group-containing substance is also used in combination in an amount of 20% by weight or less of the total amount of the total monomer mixture (A), and is obtained by polymerization, and has excellent adhesion to polyolefin materials in particular. In addition, although it contains a mixture of so-called modified chlorinated polyolefin and modified cyclized rubber as an essential component, unmodified chlorinated polyolefin is added to the composition of the present invention in order to further strengthen this adhesion. You may let them. The thus obtained composition of the present invention has excellent long-term adhesion and adhesion in a broad sense such as interlayer adhesion with the top coat, as well as a cured coating film with excellent coating performance in solvent resistance. It can be widely applied to various polyolefin materials and base materials such as various molded products such as films and sheets. For example, it can be used as a primer in coating polyolefin molded products, and It can be used as a top coat for various structures and structures, and can also be used as a binder for printing inks, but it is especially useful for various molded products, structures, and structural articles made from polyolefin. . Thus, the composition of the present invention can be used as a coating for molded articles, structures, or structural articles made of homopolymers or copolymers of α-olefins such as ethylene, propylene, 1-butene, or 3-methyl-1-heptene. It can be applied particularly to polyolefin molded products containing fillers such as titanium oxide, talc or silica, and can be used as a clear paint or as a well-known and commonly used additive such as pigments and leveling agents. Of course, the components may be mixed together and used as an enamel paint. Next, the present invention will be specifically explained with reference to Examples and Comparative Examples. In the following, all parts and percentages are based on weight unless otherwise specified. Example 1 "Hardren 14LLB" (chlorinated polypropylene manufactured by Toyo Kasei Kogyo Co., Ltd.; chlorination rate = 28%, nonvolatile content = 30%) was placed in a reactor equipped with a stirrer and a cooler.
10 g of "CK-514" (a cyclized rubber made by Hoechst, West Germany) and 80 g of toluene were supplied to bring the reactor temperature to 80°C, and 60 g of methyl methacrylate and 15 g of isobutyl methacrylate were added thereto. 0.4 g of benzoyl peroxide (hereinafter abbreviated as BPO) and 0.4 g of azobisisobutyronitrile (hereinafter abbreviated as ABIN) were added to 35 g of toluene. After the dissolved material was added dropwise over 3 hours and maintained at the same temperature for 12 hours, the solid content (non-volatile content) became 40.3%. A mixture of chlorinated polypropylene modified with an acrylic monomer and cyclized rubber modified with this monomer was obtained. Next, "Alpaste 1109MA" (product of Toyo Aluminum Co., Ltd.) was added to 100 parts of this modified resin mixture.
After blending 6.8 parts of the above, the viscosity was adjusted using thinner to give a viscosity of 15 seconds using an Iwata cup. The sheet was spray painted and then forced dry at 60°C for 30 minutes. The coating film thus obtained has a metallic feel,
Adhesion was good, solvent (gasoline) resistance was also good, and the results of the cross-cut test (durability) after being left for 6 months were also good. These results are the first
Shown in the table. Example 2 In the same manner as in Example 1, except that the same amount of cyclohexyl methacrylate was used instead of isobutyl methacrylate, chlorinated polypropylene modified with an acrylic monomer and chlorinated polypropylene with a nonvolatile content of 40.5% were prepared, respectively. A mixture with cyclized rubber was obtained. Thereafter, the same operations as in Example 1 were repeated to form a paint, and then a coating film was obtained. This coating film was also subjected to performance evaluation tests for initial adhesion, durable adhesion, gasoline resistance and alcohol resistance, and the results are summarized in Table 1. Example 3 The amounts of "CK-514", methyl methacrylate, BPO and ABIN were changed to 5 g, 58.5 g, 0.3 g and 0.5 g, respectively, and 1.5 g of maleic anhydride was also used. Except for this, a mixture of chlorinated polypropylene and cyclized rubber each modified with a vinyl monomer and having a nonvolatile content of 40.5% was obtained in the same manner as in Example 1. Thereafter, the same operations as in Example 1 were repeated to form a paint, and then a coating film was obtained. This coating film was also subjected to performance evaluation tests for initial adhesion, durable adhesion, gasoline resistance and alcohol resistance, but these results were
They are summarized in the table. Comparative Example 1 In a reactor similar to Example 1, a “Super Chron”
37.5 g of "507" (chlorinated polypropylene manufactured by Sanyo Kokusaku Pulp Co., Ltd.; chlorination rate = 66%, non-volatile content = 40%)
Add 97.5g of toluene and set the internal temperature to 80℃.
and add thereto 60 g of methyl methacrylate, 25 g of cyclohexyl methacrylate and 30 g of toluene.
A solution prepared by dissolving 0.35 g of BPO and 0.3 g of ABIN was added dropwise over 3 hours to the sample, and the mixture was further maintained at the same temperature for 12 hours to be modified with an acrylic monomer with a non-volatile content of 40.5%. A chlorinated polypropylene was obtained. Thereafter, this modified product was used to form a paint in the same manner as in Example 1, and then a coating film was obtained. This coating film was also subjected to performance evaluation tests for initial adhesion, durable adhesion, gasoline resistance and alcohol resistance, and the results are summarized in Table 1.

【table】

【table】

Claims (1)

[Claims] 1 (A) 50 to 100% by weight of acrylic ester and/or methacrylic ester (a-1);
A vinyl monomer mixture consisting of 0 to 50% by weight of the above (a-1) and other copolymerizable vinyl monomer (a-2) is added to (B) with a chlorination rate of 50% by weight. % or less of chlorinated polyolefin and (C) cyclized rubber, the above-described (A), (B) and (C) are added to these chlorinated polyolefin (B) and cyclized rubber (C).
A graft obtained by polymerizing three components in a solid content of 10 to 80% by weight of (A), 89 to 5% by weight of (B), and 1 to 10% by weight of (C), respectively. A resin composition for paint, comprising a copolymer as a film-forming polymeric binder.