JPS58176207A - Coating resin composition - Google Patents

Abstract

PURPOSE:A coating resin composition excellent in compatibility, adhesion and solvent resistance, containing a graft copolymer prepared by polymerizing a specified chlorinated polyolefin with both a (meth)acrylate ester and an unsaturated carboxylic acid. CONSTITUTION:A resin composition containing a graft copolymer prepared by polymerizing a chlorinated polyolefin, chlorination degree <=50%, with (a) 40- 99wt% acrylate ester and/or methacrylate ester, (b) 1-10wt% unsaturated carboxylic acid and (c) 0-5wt% other vinyl monomer copolymerizable with components (a) and (b) so that the total of monomers (a), (b) and (c) is 100wt%, and that the weight ratio between the solids of the chlorinated polyolefin and the monomer mixture can fall within the range of 10:90-90:10.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a new and useful resin composition for coatings,
Its purpose is to serve as a primer for so-called unprocessed polyolefin base materials, such as films, sheets, or molded products that have not been subjected to any surface treatment, such as rice grains that need to be coated. It is an object of the present invention to provide a resin composition which has good adhesion and solvent resistance, and which can also be applied in a one-coat manner.

Conventional paints made of alkyd, acrylic, and epoxy resins have almost no adhesion to various molded products made of crystalline polyolefins, which have low polarity.
For this reason, it has been proposed to use primers such as atactic polypropylene modified with maleic anhydride or ethylene-propylene copolymers modified with maleic anhydride for coating such polyolefin base materials. All of these have good adhesion to such substrates, but have poor interlayer adhesion with the top coat (and when used as a clear paint, the coating film becomes cloudy, and on the other hand, the pigment When applied as an enamel paint containing , there was a problem that the pigment dispersion was significantly poor and the paint lacked stability.

Additionally, a method is known in which chlorinated polyolefin itself is used as a primer and acrylic resin is applied as a top coat. It has the disadvantage that it decreases.

Furthermore, although it is known to use chlorinated polyolefin itself as a top coat, the hardness, solvent resistance, and weather resistance of the coating film are significantly deteriorated, so this is also impractical and is not suitable for X, So polyolefin base materials. A coating composition that maintains long-term adhesion or interlayer adhesion with the top coat, and also has improved coating performance such as solvent resistance and hardness, is made from a chlorinated polyolefin and an acrylic copolymer. Although these resin compositions are effective, compositions formed by blending such acrylic copolymers and 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. However, in order to improve adhesion, the chlorination rate must be 50%.
The following could be possible by using a chlorinated polyolefin with a chlorination rate of around 55%, but on the other hand, it may lack compatibility with the acrylic copolymer and the stability of the paint may be affected. It is extremely difficult to put it to practical use, as it causes extremely bad results.

However, the present inventors have further improved the compatibility between a specific chlorinated polyolefin and an acrylic (co)polymer,
At the same time, as a result of intensive research to improve the adhesion to polyolefin base materials, we developed a vinyl monomer whose essential components are (meth)acrylic acid ester and unsaturated carboxylic acid, with a chlorination rate of 50%. A vinyl monomer is grafted onto a chlorinated polyolefin obtained by polymerizing the following specific chlorinated polyolefin.
In other words, we have completed the present invention by demonstrating that acrylic or vinyl-modified chlorinated polyolefins have excellent compatibility as well as good adhesion.

That is, the present invention applies (meth)acrylic acid ester/L to chlorinated polyolefin with a chlorination rate of 50% or less.
(a) 40-99% by weight and unsaturated carbon Kb) 1-1
0:1li1% and other vinyl monomer mel copolymerizable with these (&) and Xb), these (a), (b)
), (c) such that the total amount of the monomers is 100% by weight, and the solid content weight ratio of the chlorinated polyolefin and the monomer mixture is 10:90 to 90:10. The object of the present invention is to provide a coating resin composition comprising as a main component a graft copolymer obtained by polymerizing as follows.

Here, the above-mentioned chlorinated polyolefin refers to a polyolefin with a chlorination rate of 50% or less, preferably 10 to 40%. Typical polyolefins include ethylene, propylene, 1-butene,
Homopolymers or copolymers of α-olefins such as 6-methyl-1-butene, 3-methyl-1-heptene, or ethylene-□1=yaco□-o1. ka57ka2,7□engineering,
.

There are copolymers of α-olefins and other vinyl monomers such as tyrene-acrylic acid ester copolymers, and therefore, typical examples of such chlorinated polyolefins include chlorinated polyethylene and chlorinated polypropylene. , chlorinated ethylene-propylene copolymer or chlorinated ethylene-vinyl acetate copolymer.

Regarding the chlorination rate of the chlorinated polyolefin, if the chlorination rate exceeds 50%, the adhesion to the polyolefin base material decreases. This should be done while taking into account various coating film properties such as hardness and hardness, and should preferably be 10 to 40%, more preferably 15 to 35%, and in this way the most balanced coating film can be obtained. A resin composition with properties can be obtained.

On the other hand, typical examples of the above-mentioned (meth)acrylic acid ester A(a) include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate,
Examples include isobutyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, or cyclohexyl (meth)acrylate. Either one type or two or more types may be used (and for these, there is no problem even if some monomers containing functional groups such as hydroxyl groups, glycidyl groups, or acid groups are used in combination). Copolymerization of such functional group-containing monomers is particularly recommended for improving solvent resistance, pigment dispersibility, and the like.

If the amount of the (meth)acrylic acid ester A(a) is less than 40Mt%, the hardness and solvent resistance of the resulting coating film will be insufficient. It should be at least 40% by weight of the total amount of monomers, but if it exceeds 99% by weight, problems tend to occur in terms of compatibility, so it is preferably 45 to 9% of the total amount of monomers.
A range of 0% by weight is suitable. Typical examples of other vinyl monomers c) copolymerizable with the (meth)acrylic acid ester/L(a) include styrene or diptyl fumarate. , diesters of unsaturated dibasic acids such as dimethyl malate or dibutyl itaconate, etc. These monomers are used as appropriate depending on the desired coating performance, but the amount used depends on the total amount of monomers. It should be less than 50-fold.

Furthermore, typical examples of the unsaturated carboxylic acid (mb) include maleic anhydride, fumaric acid, itaconic acid, citraconic acid, and (meth)acrylic acid.

And, the usage amount of the unsaturated carvone [b) is as follows:
If these are less than 1% by weight, the pigment dispersibility will be insufficient, and if they are more than 10% by weight, the water resistance of the resulting film will be reduced.
] i amount%, preferably 1 to 5% by weight is suitable.

Therefore, when polymerizing the above-mentioned monomers (mixture) to the chlorinated polyolefin, the usage ratio of these chlorinated polyolefins and monomers (mixture) is 1.
o:90-90:10, preferably 15:85-60
:40.

In addition, by such polymerization, a vinyl monomer component such as (meth)acrylic acid ester (a) is grafted onto the chlorinated polyolefin component, and as a result, a modified chlorinated polyolefin with good compatibility is obtained. However, as a method for such polymerization, it is usually best to carry out solution polymerization at a polymerization temperature of 60 to 100°C using a radical-generating polymerization initiator such as benzoyl peroxide or azobisisobutyronitrile. When the ratio of chlorinated polyolefin and monomer (mixture) described above exceeds 10:90 in solid weight ratio and the amount of chlorinated polyolefin decreases, the adhesion to the polyolefin base material decreases. Therefore, it is not preferable, and on the contrary, it is 90
: If the amount of chlorinated polyolefin increases beyond 10, it is undesirable because the solvent resistance of the resulting coating film will significantly decrease. Or methacrylic acid ester A (a) and unsaturated carvone! ! I
(b) is an essential monomer component.

Other vinyl monomers C) copolymerizable with both types of monomers (a) and b) may also be added to 50% of the total amount of all monomers.
If necessary, functional group-containing monomers such as those described above may be used in combination within a range of not more than 20% of the total weight of all monomers.
Obtained by polymerization in combination with J11% or less,
In particular, it has excellent adhesion to polyolefin base materials.
Although the main component is a so-called modified chlorinated polyolefin, an unmodified chlorinated polyolefin may be added to the composition of the present invention in order to further strengthen the adhesion.

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 film with excellent solvent resistance. It provides a coating film and can be widely applied to various polyolefin materials or 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. It can also be used as a top coat □ for rice structures and structures, and it can also be used as a binder for printing inks, but especially for various molded products, structures or structures made from polyolefin. Useful for structures.

Thus, the composition of the present invention can be used as a coating for molded articles, structures, or structures 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 In a reactor equipped with a stirrer and a cooler, 5 o
II 15 g of maleic anhydride and 80 g of toluene were added, the temperature inside the vessel was raised to 80°C, and 595I methyl methacrylate, 24 g of isobutyl methacrylate, and 0.4 g of toluene were added.
g of benzoyl peroxide and 0.4! A solution prepared by dissolving azobisisobutyronitrile (i) in 55 g of toluene was added dropwise over 3 hours, and the mixture was further maintained at the same temperature for 12 hours to reach a solid content (non-volatile content) of 40.3%. Acrylic-modified chlorinated polypropylene was obtained.Next, 100 parts of this resin was mixed with 1 part of "Pulpaste".
After blending 6.8 parts of 109MAJ (Toyo Aluminum ■ product), the viscosity was adjusted using thinner so that it would take 15 seconds in an Iwata cup. A sheet with a thickness of 5w5x made from the above was spray-coated and then force-dried at 60°C for 30 minutes.

The coating film thus obtained had a metallic feel, had good adhesion, and good solvent (gasoline) resistance, and also had good results in the goggle test (durable adhesion) after being left for 6 months. Ta. These results are summarized in Table 1.

Example 2 Using the same amount of itaconic acid instead of maleic anhydride,
Ka, the amount of toluene, benzoyl peroxide and azobisisobutyronitrile is 50II, 0°! Acrylic-modified chlorinated polypropylene having a nonvolatile content of 40.5% was obtained in the same manner as in Example 1, except that the amounts were changed to 15 g and Q to 3 g.

Thereafter, the same operations as in Example 1 were repeated to form a paint.
First, 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 6 Example, except that the same amount of cyclohexyl methacrylate was used in place of isobutyl methacrylate, and the amounts of benzoyl peroxide and azobisisobutyronitrile were changed to 0.3 g and 0.5 g. A vinyl-modified chlorinated polypropylene having a nonvolatile content of 4Q and 2% was obtained in the same manner as in Example 1.

Thereafter, the same operations as in Example 1 were repeated to form a paint.
A coating film was then obtained.

The evaluation tests for initial and durable adhesion and gasoline and alcohol resistance of this coating film are summarized in Table 1.

Comparative Example 1 In the same reactor as in Example 1, "Super Chron 507" was used.
(Chlorinated polypropylene manufactured by Sanyo Kokusaku Pulp ■; chlorination rate = 66%, solid content = 40%) 57.577 and toluene 97, 59 were added, the temperature inside the vessel was raised to 80°C, and methyl methacrylate 59. 5g, isobutyl methacrylate 24g, maleic anhydride t5Ii and toluene 30g
, benzoyl peroxide of α3511 and α3
A solution containing g of azobisisobutyronitrile was added dropwise over 3 hours, and the mixture was kept at the same temperature for 12 hours to obtain acrylic-modified chlorinated polypropylene with a nonvolatile content of 40.5%.

Thereafter, this resin was made into a coating in the same manner as in Example 1, and a coating film for comparison was also obtained.

This coating film was also subjected to evaluation tests for initial and durable adhesion as well as gasoline and alcohol resistance, as shown in Table 1.

Claims (1)

[Claims] For a chlorinated polyolefin with a chlorination rate of 50% or less, (&) an acrylic ester and/or a methacrylic ester 40 to 99%, and (b) an unsaturated carboxylic acid 1 to 1011f. %and,(
e) 0 to 50% of other vinyl monomers copolymerizable with Ha) and A graft copolymer obtained by polymerizing the chlorinated polyolefin and the monomer mixture so that the amount of S is %, and the solid content weight ratio of the chlorinated polyolefin and the monomer mixture is 10:90 to 90:10. A paint resin composition comprising: