JPS6134008A - Coating resin - Google Patents

Abstract

PURPOSE:A coating resin soluble in mineral turpentine and excellent in compatibility with a long-oil alkyd resin, obtained by copolymerizing specified two compounds with monoethylenically unsaturated copolymerizable compound. CONSTITUTION:A mixture of 65-99wt% compound of formula I (wherein R1 is a 2-20C alkyl) and 1-5wt% compound of formula II (wherein R2 is H or CH3 and R3 is CH3 or C2H5) is copolymerized with 0-30wt% monoethylenically unsaturated copolymerizable compound [e.g., (meth)acrylic acid] in the presence of a radical-generating initiator (e.g., azobisisobutyro-nitrile) and, optionally, a chain transfer agent such as n-dodecyl mercaptan.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an acrylic copolymer that has good compatibility with alkyd resins.

More specifically, the present invention relates to an acrylic copolymer that can impart the properties of an acrylic resin while maintaining the properties of an alkyd coating by dissolving it in an alkyd coating.

(Conventional technology) Alkyd resins have been widely used as paints, but they have poor coating performance such as durability, UV resistance, chemical resistance, and stain resistance. Studies have been conducted on coating resin compositions in which acrylic resins, which have excellent durability, UV resistance, chemical resistance, stain resistance, etc., are blended with alkyd resins.

(Problems to be Solved by the Invention) However, acrylic resins generally have problems such as poor compatibility with alkyd resins and difficulty in dissolving in mineral turpentine (a bath additive with a low content of aromatic compounds). .

With the aim of improving the above-mentioned problems, the present inventors have made intensive studies and found that acrylic resin is soluble in mineral turpentine and has excellent compatibility with alkyd resin, and by blending it with alkyd resin. The present invention was completed by discovering an excellent new acrylic copolymer that can provide the following properties.

(Structure of the Invention) That is, the present invention provides a compound represented by (1) CH2=CCH3COOR1 (wherein R1 is an alkyl group having a carbon number of - to θ), which has a weight coefficient of +2>0H.
2=CR2(1'oo(CH,)2N(R3)2 (where R2 is hydrogen or methyl group, R3 is methyl or ethyl group)
(8) Acrylic type with good compatibility with long oil type alkyd resin obtained by copolymerizing 1 to 5% by weight of a compound represented by (8) 0 to 30% by weight of other copolymerizable warp ethylenically unsaturated compounds. The present invention provides a copolymer.

(1) CH2-0CR3COOR used in the present invention
Examples of the compound represented by 1 include butyl methacrylate, cyclohexyl methacrylate, coethylhexyl methacrylate, stearyl methacrylate, etc., but butyl methacrylate is particularly preferred.

Mata, invention 1: for iso h 6 (2) CH2=C
Examples of R2COO(CH2)2N(Rx)2 include diethylaminoethyl methacrylate and diethylaminoethyl methacrylate, but preferably,
Diethylaminoethyl methacrylate.

Copolymerizing these compounds in amounts of /~5% by weight is effective in improving the compatibility with the alkyd resin, which is a feature of the present invention.

If the amount of this compound is less than the /weight ratio, the compatibility with the alkyd resin becomes unstable and phenomena such as cloudiness and two-layer separation occur, which is not preferable. Moreover, if the amount is more than J weight factor, it is not preferable because it will be colored after being mixed with the alkyd resin.

In addition to (1) or (2) above, specific examples of (8) other copolymerizable monoethylenically unsaturated compounds used in the present invention include acrylic acid, methacrylic acid, or (
Examples include acrylates and methacrylates other than 1) and (2).

One or more of these are used in a range of 0 to 3θ weight to obtain the desired coating performance.

For example, it is desirable to use a higher methacrylic ester such as benzyl methacrylate to provide a high degree of water resistance, and a lower acrylic ester such as butyl acrylate to provide a high degree of adhesion.

When the amount of these monoethylenically unsaturated compounds exceeds 300 parts by weight, the adhesiveness of the resin decreases, making it difficult to obtain a solid powder.

The acrylic resin used in the present invention can be prepared using a known suspension polymerization method.
It can be obtained by emulsion polymerization.

As the initiator, commonly used radical generating initiators,
For example, azobisisobutyronitrile, lafuroyl peroxide, benzoyl peroxide, etc. can be used.

As a chain transfer agent, n-dodecyl mercaptan, n-
Mercaptans such as octyl mercaptan are used as necessary.

The properties of the alkyd resin used in the present invention can generally be varied by changing the types, amounts, and combinations of each component, such as animal and vegetable oils, fatty acids, polybasic acids, and polyhydric alcohols. By changing the amount of animal and vegetable oils or fatty acids, it is possible to obtain long-oil, medium-oil, and short-oil alkyd resins.

The acrylic resin of the present invention has an oil length j0~
Excellent compatibility with long-oil type alkyd resins with a coefficient of ♂θ. The oil length herein refers to the content of the latter, that is, the oil content, as it is composed of two components: phthalic acid glyceride, which is an alkyd resin, and fatty acid triglyceride.

Preparation of test piece A resin paint made from a blend of acrylic resin and alkyd resin was applied to a tin plate (θ, ♂ x 70X/3; θ■) that had been degreased with a mixed solution of equal amounts of ethanol and toluene to a film thickness of 25 to 30.
It was coated with an applicator so that it was .mu.m, dried at room temperature, and evaluated.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Examples 7 to 6, Comparative Example 1-2 200 parts by weight of water, 0.3 parts by weight of emulsifier, 0.7 parts by weight of initiator, and 0.7 parts by weight of emulsifier were added to 200 parts by weight of water in a Nishitsurov 2 Scooter equipped with a stirrer, a reflux condenser, and a thermometer.
The mixture was heated to 7θ°C, and 10θ parts by weight of the monoyer mixture shown in Table 1 was continuously added over about 7 hours, and the reaction was further carried out at 70°C for 1 hour. After the reaction was completed, the desired acrylic resin was obtained by salting out, washing, and drying. The obtained acrylic resin is made into industrial gasoline (mineral turpentine)! It was dissolved at a concentration of θ, mixed with an equal amount of a commercially available long oil alkyd resin (Harifthal, manufactured by Harima Kasei), and its compatibility was observed. The results are shown in Table-7.

(Leaving space below) Table 7 List of turpentine solubility and compatibility evaluation evaluation rank symbols Examples 2~/4t, Comparative Example 3 The respective acrylic resins and alkyd resins used in Examples/~B and Comparative Example Bv alkyd resin = 3/2, ♂/2.9// (weight ratio) was blended, metal soap was added, and the coating film was evaluated according to JIq Ni-j'100.

The evaluation results of coating film performance are shown in Table-C.

Comparative Example: The coating film performance was evaluated in the same manner as in Example No./4t using a commercially available Flukyd resin (Harifthal, manufactured by Harima Kasei). The results are shown in Table-2.

The evaluation results are shown in Table-/ and Table-1.

As is clear from the results in Table 2, if the amount of diethylaminoether methacrylate in the copolymer is less than 7 parts, the copolymer loses its compatibility with the alkyd resin.

Moreover, if it exceeds 5 parts, the water resistance is poor and there is a practical problem. On the other hand, the acrylic resin of the present invention is soluble in turpentine and can be blended with an alkyd resin at any mixing ratio, so an appropriate blending ratio can be determined to obtain the desired coating performance. For example, the acrylic resin of Example G has good adhesion even in areas where the acrylic resin concentration is high. The coating composition using the acrylic resin in Example 2 had good water resistance.

Claims (3)

[Claims] (1) CH_2=CCH_3COOR_1 (However, R_1
is an alkyl group having 2 to 20 carbon atoms) 65 to 99% by weight (2) CH_2=CR_2COO(CH_2)_2N(
R_3)_2 (However, R_2 is hydrogen or methyl group, R_
3 is a methyl or ethyl group)
weight% (3) An acrylic copolymer having good compatibility with a long oil type alkyd resin and obtained by copolymerizing 0 to 30% by weight of other copolymerizable monoethylenically unsaturated compounds.