JPS59140269A - Paint resin composition - Google Patents

Abstract

PURPOSE:To provide a resin compsn. which can be used as a primer as well as one coat system and has excellent adhesion and solvent resistance, containing a hydroxyl group-contg. vinyl copolymer, a specified graft reaction mixture and an isocyanate compd. CONSTITUTION:A resin compsn. contains 50-80pts.wt. hydroxyl group-contg. vinyl copolymer (A) obtd. from 1-40wt% hydroxyl group-contg. monomer, 10- 99wt% acrylate and/or methacrylate ester and 0-50wt% other copolymerizable monomer, a graft reaction mixture (B) obtd. by polymerizing 50-100wt% acrylate and/or methacrylate ester and 0-50wt% other copolymerizable monomer in the presence of a chlorinated polyolefin having a degree of chlorination of 50% or below in such a proportion as to give a weight ratio of chlorinated polyolefin (on a solid basis) to the monomer of 90:10-50:50 and an isocyanate compd. (C) in a quantity of NCO/OH=0.5/1-1.2/1 by equivalent.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel and useful resin M acid compound for coatings, which can be applied to films or sheets or other various types of resins that have not been subjected to any of the various surface treatments to impart paintability. To provide a resin composition for paint that has a function as a brimer for so-called untreated polyolefin materials such as molded products, can be applied in a one-coat manner, and has good adhesion and solvent resistance. The purpose is to

Conventional paints made of alkyd, acrylic, and epoxy resins have little adhesion to various molded products made of crystalline polyolefins, which have low polarity. As a primer, it has been proposed to use, in particular, an acidic polypropylene modified with maleic anhydride or an ethylene-propylene copolymer modified with maleic anhydride, but these all have poor adhesion to such materials. Although it is good, it has poor glabella adhesion with the top coat, and when used as a clear paint, the coating film becomes cloudy.On the other hand, when applied as an enamel paint system containing pigments, There were problems in that the pigment dispersion was extremely poor and the stability of the paint was also lacking.

Furthermore, a method is known in which chlorinated polyolefin itself is used as a brimer and an acrylic resin or the like is applied as a top coat. However, such methods have the disadvantage that interlayer adhesion with the top coat, solvent resistance, and long-term durable adhesion are reduced.

Furthermore, it is known to use chlorinated polyolefin itself as a top coat, but the hardness, solvent resistance,
It is impractical because its weather resistance is extremely poor.

Resin compositions for coatings that maintain long-term adhesion to polyolefin materials and interlayer adhesion with top coats, and have improved coating performance such as solvent resistance and hardness include chlorinated polyolefins and acrylic ) polymers are effective, but compositions formed by blending acrylic (co)polymers and chlorinated polyolefins include the following problems. That is, the chlorination rate is 50% by weight (
(hereinafter abbreviated as %) or more, the compatibility between the chlorinated polyolefin and the acrylic (co)polymer improves, but the adhesion and solvent resistance of the formed coating film decreases, making it difficult to use for practical purposes. be. On the other hand, it is possible to improve adhesion by using a chlorinated polyolefin with a chlorination rate of 50% or less, for example around 35%, but it lacks compatibility with acrylic (co)polymers. However, the stability of the paint becomes extremely poor and the solvent resistance is also poor, making it difficult to use it practically.

However, the present inventors improved the compatibility between these chlorinated polyolefins and acrylic copolymers, and
As a result of intensive research to improve the adhesion and solvent resistance of various polyolefin materials, we developed a hydroxyl group-containing vinyl copolymer; a chlorinated vinyl monomer containing (meth)acrylic acid ester as an essential component. rate is 50
% or less; and a resin composition containing an isocyanate compound as an essential component has good adhesion,
The present invention was completed based on the discovery that a coating film having solvent resistance, particularly gasoline resistance, can be obtained.

That is, the present invention uses 1 to 40% by weight of the hydroxyl group-containing monomer (a-1) and 10 to 40% by weight of the acrylic ester and/or methacrylic ester (a-2) as essential components.
99% by weight and 50 to 50% of other copolymerizable monomer (a-3)
Acrylic ester and/or methacrylic ester (a -2) 50~io
o weight i% and 0 to 50 of the other copolymerizable monomer (a-3)
% by weight of the chlorinated polyolefin and the monomer (a-
2), solid content weight ratio with (a-3) is 90:10 to 50
: Grafting reaction mixture (B) obtained by polymerization in a ratio of 50% and isocyanate compound (C
) and the hydroxyl group-containing vinyl copolymer (A) is 50 to 8
0 parts by weight, the grafting reaction mixture (B) is 20 to 50 parts by weight.
The hydroxyl group (OH) in the hydroxyl group-containing vinyl copolymer (A) and the isocyanate compound (
The equivalent ratio with the isocyanate group (NGO) in C) is
010H=0.5/1 to 1.2/1.

Here, typical examples of the hydroxyl group-containing monomer (a-1) include β-hydroxyethyl (meth)acrylate, β-hydroxypropyl (meth)acrylate, and β-hydroxybutyl (meth)acrylate. .

Further, typical examples of the acrylic ester and/or methacrylic ester (a-2) include methyl (meth)acrylate, ethyl (meth)acrylate, (
Examples include isobutyl meth)acrylate, isobutyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, and cyclohexyl (meth)acrylate.

Further, typical examples of the other copolymerizable monomer (a-3) include diesters of unsaturated dibasic acids such as styrene, dibutyl fumarate, dimethyl maleate, or dibutyl itaconate; ) Acid group-containing monomers such as acrylic acid, fumaric acid, maleic acid or itaconic acid. Further, there is no problem in partially using (meth)acrylonitrile or dimethylaminomethyl (meth)acrylate in combination.

Each of these monomers (a-1,), (a-2) and (a
-3) using the hydroxyl group-containing vinyl copolymer (A
), using a solvent such as an aromatic solvent such as toluene or xylene, an ester solvent such as ethyl acetate or butyl acetate, or a ketone solvent such as methyl ethyl ketone or methyl isobutyl ketone, and the presence of an initiator that generates a radical group. It can be easily obtained by solution polymerization.

Next, the chlorinated polyolefin has a chlorination rate of 50%.
Hereinafter, polyolefins preferably having a content of 10 to 45% will be referred to, and representative polyolefins include ethylene, propylene, x-butene, 3-methyl-1-butene, 3-methyl-1-heptene, etc. There are homopolymers or copolymers of α-olefins, or copolymers of α-olefins with other vinyl monomers such as ethylene-vinyl acetate, ethylene-butadiene, ethylene-acrylic acid ester, etc. Typical examples of the chlorinated polyolefin include chlorinated polyethylene, chlorinated polypropylene, chlorinated ethylene-propylene copolymer, and 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, so the determination of the chlorination rate is based on the adhesion and flexibility. This should be done while taking into consideration various coating film performances such as hardness and hardness, preferably 10 to 4.
It should be 5%, more preferably 15-35%, in this way a resin composition with the most balanced coating performance is obtained.

In addition, the acrylic ester and/or methacrylic ester (a-2) used in preparing the grafting reaction mixture (B) may also contain other copolymerizable monomers (
The monomers a-3) listed above can also be used as they are, but in this case, the monomer (a-2) may be used alone or in combination of two or more. For the monomer (a-2), there is no problem even if a part of the monomer containing a functional group such as a hydroxyl group, a glycidyl group or an acid group is used in combination. Polymerization is particularly recommended for improving solvent resistance and pigment dispersibility.

If the amount of the (meth)acrylic ester (a-2) used is less than 50% by weight, the resulting coating film will have insufficient hardness and solvent resistance, so the amount used should be 50% by weight. or more, preferably 60 to 90
The weight is the weight.

On the other hand, the type of monomer (a-3) is appropriately determined depending on the desired coating performance, but the amount used should be less than 50% by weight.

In polymerizing the monomers described above in the presence of the chlorinated polyolefin, the abundance ratio of the chlorinated polyolefin and the monomer (mixture) is 90:10 to 50:50,
Preferably, a solid content weight ratio of 8515 to 6o':4o is suitable.

In addition, through such polymerization, a polymeric monomer component such as a (meth)acrylic acid ester is grafted onto a chlorinated polyolefin component, and as a result, a graft containing an acrylic-modified chlorinated polyolefin with good compatibility is obtained. A reaction mixture is obtained, and the method for such polymerization is usually solution polymerization at a polymerization temperature of 60 to 100° C. using a radical-generating polymerization initiator such as benzoyl peroxide or azobisisobutyronitrile. In this case, when the ratio of each chlorinated polyolefin to the monomer mentioned above exceeds 50:50 in solid weight ratio and the amount of chlorinated polyolefin decreases, the adhesion to the polyolefin base material decreases. On the other hand, when the amount of chlorinated polyolefin increases beyond 90:10, it is not preferable because the solvent resistance of the resulting coating film decreases significantly.

Thus, the grafting reaction mixture (B) contains acrylic ester and/or in the presence of chlorinated polyolefin.
Alternatively, methacrylic acid ester (a-2) is used as an essential monomer component, or other vinyl monomer (a-3) copolymerizable with these monomers (a-2) is used as a total monomer. The monomers containing functional groups as described above may be used in combination in an amount of 50% by weight or less based on the total amount of the monomer components, and if necessary, a functional group-containing monomer as described above may also be used in combination in an amount of 20% by weight or less based on the total amount of monomer components. The main component is a so-called modified chlorinated polyolefin, which has particularly excellent adhesion to polyolefin base materials.

Further, typical isocyanate compounds (C) include diisocyanates such as tolylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate; or adducts of these diisocyanates with polyhydric alcohols, but more preferably is a derivative of hexamethylene diisocyanate having a biuret structure, [Duranate 24A-1
00J (product of Asahi Kasei Kogyo) or "Desmodur To" (product of Bayer AG, West Germany), and "Coronate EIIJ" (product of Nippon Polyurethane Industries), which is an adduct of hexamethylene diisocyanate and cyanuric acid.

The usage ratio of the compound (C) and the hydroxyl group-containing vinyl copolymer (A> is determined by the number of isocyanate groups (NGO) in one molecule and the number of hydroxyl groups (OH) in one molecule, respectively.
It is appropriate that the ratio to the number of NGO10H is in the range of 0.5/1 to 1.2/1; if it is out of this range, a coating film with excellent solvent resistance will not be obtained.

The composition of the present invention thus contains the hydroxyl group-containing vinyl copolymer (A), the grafting reaction mixture (B), and the isocyanate compound (C) as essential components. There is no problem in incorporating an unmodified chlorinated polyolefin into the composition of the present invention in order to further improve the properties.

The composition of the present invention thus obtained has excellent long-term adhesion and adhesion in a broad sense such as interlayer adhesion with the top coat, as well as coating film performance with excellent solvent resistance. It provides a cured coating film and 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 brimer in coating polyolefin molded products. It can also be used as a top coat for various structures and structures, and it can also be used as a binder for printing inks, but it can also be used for various molded products and structures made of polyolefin. Useful for the body or structures.

Thus, the composition of the present invention can be applied as a coating to molded articles, structures, or structures made of homopolymers or copolymers of α-olefins such as ethylene, propylene, niebutene, or 3-methyl-1-heptene. In particular, it exhibits excellent adhesion to polyolefin molded products containing fillers such as titanium oxide, talc, or silica, and can be used as a clear coating or as a well-known and commonly used additive component such as pigments and leveling agents. Of course, it may be used as an enamel paint in a mixed form.

Next, the present invention will be specifically explained with reference to Reference Examples and Examples. In the following, all parts and percentages are based on weight unless otherwise specified.

Reference Example 1 [Preparation example of hydroxyl group-containing vinyl copolymer (A)] 80 g of toluene was placed in a reactor equipped with a stirrer and a cooler.
was charged, the temperature inside the reactor was set to 105°C, and a monomer mixture consisting of 60 g of methyl methacrylate, 24 g of isobutyl methacrylate, 15 g of 1β-hydroxyethyl methacrylate, and 1 g of methacrylic acid, and 0.5 g of azobisisobutyronitrile (AIBN) were added. A solution of 5 g in toluene at 20 F was added dropwise over a period of 3 hours.

After that, the reaction was continued at the same temperature for 0 hours, and a desired copolymer with a non-volatile content (N V) of 50.4% was obtained.Hereafter, this was referred to as resin (A-1). Abbreviated.

Reference Example 2 (same as above) 29 g of n-butyl methacrylate was used instead of isobutyl methacrylate, 10 g of β-hydroxymethyl methacrylate was used instead of β-hydroxyethyl methacrylate, and 0.0 g of β-hydroxymethyl methacrylate was used instead of AIBN. Except for changing to use 6g of benzoyl peroxide.
A desired copolymer having an N V of 50.8% was obtained in the same manner as in Reference Example 1. Hereinafter, this will be abbreviated as resin (A-2).

Reference Example 3 [Example of Preparation of Grafting Reaction Mixture (B)] In a reactor equipped with a stirrer and a cooler, a
LBJ (chlorinated polypropylene manufactured by Toyo Kasei Kogyo ■; N
6 (log, 8 g of methyl methacrylate, 2 g of isobutyl methacrylate, and 0.05 g of AIBN) (toluene solution with v of 15%) were charged, and the temperature inside the reactor was raised to 80.
When the temperature was raised to 'C and held at the same temperature for 12 hours, the NV was 1.
A desired reaction mixture of 6.5% was obtained. Hereinafter, this will be abbreviated as resin (B-1).

Reference Example 4 [Same - H] "The amount of Birdren 14LL old was changed to 533 g, the amount of methyl phosphate was changed to 16 g, the amount of isobutyl methacrylate was changed to 4 g, and the amount of AIBN was changed to 0.1 g. Other than that, refer to Example 1. 100 parts of resin (A-1) (7).
0" [rutile type titanium oxide made by Ishiya Sangyo fi] was blended and kneaded in a ball mill.
B-1) 84.2S and [Coronate EHJ 1
The viscosity was adjusted by adding 1.2 parts to 25 seconds using a Ford Cup 4 with thinner.

Next, the paint obtained here was labeled as “Noblen BC3B”.
Spray paint on a 3-thick sheet made of J (polypropylene made by Mitsubishi Yuka@), then apply 4 coats at 60"C.
Force drying was performed for 0 minutes.

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

Example 2 "Coronate E) A coating film was obtained in the same manner as in Example 1, except that the amount of IJ was changed to 7.5 parts.

The physical properties of this coating film are summarized in Table 1.

Example 3 [Tie Bake l? -820J was changed to 44 parts, and instead of resin (B-1), 112.6 parts of wood 1M (B-
A coating film was obtained in the same manner as in Example 1, except that Example 2) was used.

The physical properties of this coating film are summarized in Table 1.

Example 4 In the same manner as in Example 3, except that the same amount of resin (A-2) was used instead of resin (A-1), and the amount of Coronate EHJ was changed to 7.5 parts. A coating film was obtained.

The physical properties of this coating film are summarized in Table 1.

Claims (1)

[Scope of Claims] (A) Hydroxyl group-containing monomer (a-1), 1 to 40% by weight and acrylic ester and/or methacrylic ester (a-2) 10 to 99% by weight
and another copolymerizable monomer (a-3) 0 to 50% by weight hydroxyl group-containing vinyl copolymer 50-8
0 parts by weight, (B) copolymerizable by weight with 50 to 100 weight percent of acrylic ester and/or methacrylic ester (a-2) in the presence of a chlorinated polyolefin with a chlorination rate of 50% or less 0 to 50% by weight of the monomer (a-3) is added to the solid content of the chlorinated polyolefin and the monomer (a-2).
), the weight ratio with (a-3) is 90:10 to 50:
50 to 20 parts by weight of the grafting reaction mixture obtained by polymerization so that the ratio is 50%, and (C) isocyanate compound NGO10H = 0.5/1 to 1.2/1 (equivalent ratio) as essential components. A paint resin composition comprising: a paint resin composition having good adhesion to polyolefin materials.