JPS6057471B2 - Resin composition for anticorrosion coating - Google Patents

Description

[Detailed description of the invention] The present invention relates to a resin composition for anticorrosion coating.

More specifically, the present invention relates to a corrosion-resistant resin composition using an acrylic copolymer containing a silicone-containing monomer. Hitherto, oil-based resins such as CnH2n-Si-O-R3 resins and epoxy resins have been known as resins with excellent corrosion resistance.

However, although acrylic resins have excellent physical properties, no one with sufficient corrosion resistance has yet been obtained. Furthermore, many reports have already been made regarding silicone resins, but all of them have the drawback of poor anticorrosion ability. The present invention is aimed at improving the above-mentioned defects of acrylic resins and silicone resins, and relates to the use of a combination of a silicone-containing monomer copolymer and an acrylic copolymer as a resin composition for anticorrosion coating. It is something. That is, the present invention provides (i) 0.1 to 50% by weight, preferably 2 to 3% by weight of at least one silicone-containing monomer represented by the following general formula (in the above formula, R1 and R5 are hydrogen atoms or The methyl group, R2, R3 and R4 are alkyl groups having 1 to 4 carbon atoms, and n is an integer of 1 to 12.

) Styrene 5-5% heel weight, preferably 15-4 heel weight % and (meth)atalylic acid ester 94. Acrylic copolymer consisting of 5 to 3% heel weight, preferably 83 to 3% heel weight
Acrylic copolymer containing 5 parts by weight, preferably 10 to 3 parts by weight and 5 to 5% by weight of styrene (50 to 95%)
This relates to a resin composition for anticorrosion coating comprising 70 to 9 parts by weight, preferably 70 to 9 parts by weight.

The silicone-containing monomer used in the present invention is a mixture of aminoalkylalkoxysilane and glycidyl (meth)acrylate, or a derivative thereof.

For example, aminoalkylalkoxysilanes include aminomethyltrimethoxysilane, aminoethyltrimethoxysilane, aminopropyltriethoxysilane, aminopropyltrimethoxysilane, aminopropyltripropoxysilane, N-methylaminoethyltrimethoxysilane, N- Examples include methylhexyltributoxysilane, aminolaurylpropoxydimethoxysilane, and N-methylaminopropyltrimethoxysilane. Furthermore, silicone condensates of these compounds (m of the general formula
2 or more). The silicone-containing monomer used in the present invention is generally obtained by reacting the epoxy group of glycidyl (meth)acrylate with the amino group of aminoalkylalkoxysilane.

In addition to silicone-containing monomers and styrene, vinyl monomers to be copolymerized include vinyltoluene,
(meth)acrylic acid, (meth)acrylic acid ester [e.g. methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate Examples include acrylic monomers commonly used to obtain acrylic copolymers such as acrylate, 2-hydroxyethyl (meth)acrylate, and 2-hydroxypropyl (meth)acrylate], acrylonitrile, and vinyl acetate.

Acrylic copolymer (CF) containing 5 to 5% styrene used in the present invention! These are those commonly used except that they contain a limited amount of styrene.

The method for producing the copolymers (a) and (x) used in the resin composition for anticorrosive coating of the present invention is to place an organic solvent in a four-necked flask and heat the vinyl monomer at a temperature of 100 to 140°C.
It is obtained by dropping the mixture at a constant temperature and copolymerizing it.

Organic solvents used include alcohols (methanol, ethanol, propanol, butanol, etc.), acetic esters (ethyl acetate, propyl acetate, butyl acetate, etc.), alcoholic ethers (cellosolve, methyl cellosolve, etc.), ketones (methyl ethyl ketone, methyl Propyl ketone, methyl butyl ketone,
diethyl ketone, etc.), hydrocarbons (n-hexane, n-
(heptane, n-octane, xylene, toluene, etc.). In the present invention, if the silicone-containing monomer is less than 0.1% by weight in the copolymer (a), a coating film with good anticorrosion properties cannot be obtained, whereas if it exceeds 5% by weight, the anticorrosion effect remains constant and the cost is reduced. be at a disadvantage.

Furthermore, if the amount of styrene in the copolymer (a) is less than 5% by weight, there will be drawbacks such as water marks on the coated surface, while if it exceeds 5% by weight, the anticorrosion effect will decrease. Furthermore, copolymer (
C7) & Here too, if the amount of styrene is less than 5% by weight, the condition of the coated surface deteriorates, such as water marks, and on the other hand, if the amount of styrene exceeds 5% by weight, there are defects such as a decrease in the anticorrosion effect. Next, add the acrylic copolymer (A) to the acrylic copolymer (A).
When used in combination with acrylic copolymer (a), if the amount is less than 5 parts by weight, the anticorrosion effect will be reduced, and if it exceeds 5 parts by weight, there will be defects such as poor compatibility.

Next, the present invention will be explained in more detail with reference to Examples.
In the examples, all parts and percentages are expressed by weight. Example 1 (a) Synthesis of silicone-containing resin Styrene 25 parts Adduct of mono-aminopropyltrimethoxysilane and glycidyl methacrylate 25 parts n-butyl acrylate
45 parts methyl methacrylate
5 parts tertiary butyl peroctate 0.
05 parts, 43 n-butyl acetate in a 2' four-necked flask
The above mixture was added dropwise over 5 hours to the mixture heated to reflux temperature under stirring while nitrogen gas was introduced.

As an additional catalyst, 0.05 part of azobisisovaleronitrile was added dropwise over about 1 hour at the above temperature, and the reaction was further carried out at the above temperature for 3 hours to obtain a silicone-containing resin. The nonvolatile content of this resin is 60%, and W
(25°C), and the number average molecular weight was about 30,000. (
b) Synthetic styrene made from acrylic resin
25 parts n-butyl acrylate
35 parts n-butyl methacrylate 4-azobisisobutyronitrile 0.05 parts 43 parts 1 of n-butyl acetate was placed in a 2e four-bottle flask, and heated to reflux temperature under stirring while nitrogen gas was introduced. The above mixture was added dropwise to the solution over a period of 4 hours.

As an additional catalyst, 0.05 part of azobisvaleronitrile was added dropwise over about 1 hour at the above temperature, and the reaction was continued for an additional 3 hours to obtain an acrylic resin. The non-volatile content of this resin is 60%
It measured S (25°C) using a Gardner Holtz bubble viscometer and had a number average molecular weight of about 25,000. A resin composition was prepared by mixing 25 parts of (A) and 75 parts of (C). Example 2 (a) Synthesis of silicone-containing resin Styrene 5 parts Adduct of N-methylaminopropyltrimethoxysilane and glycidyl methacrylate (Sub) part 2-ethylhexyl acrylate 25 parts, methyl methacrylate
Kabe Tertiary Butyl Peroctate 0
．． 05 parts The above mixture was copolymerized in the same manner as in Example 1,
A silicone-containing resin was obtained.

This resin had a nonvolatile content of 60%, a number average molecular weight of about 30,000, and a viscosity of U (25° C.) as measured by a Gardner-Holtz bubble viscometer. j) Synthetic styrene of acrylic resin
(branch) part n-butyl acrylate
(4) Azobisvaleronitrile
0.05 parts of the above mixture was reacted in the same manner as in Example 1 to obtain an acrylic resin.

This resin had a nonvolatile content of 60%, a number average molecular weight of about 30,000, and a viscosity of T (25° C.) as measured by a Gardtorholtz bubble viscometer. A resin composition was prepared by mixing 5 parts of (a) and 95 parts of (b). Example 3 a) Synthesis of silicone-containing resin Styrene (branch) Adduct of aminoethyltrimethoxysilane and glycidyl methacrylate 0.1 part 2-hydroxypropyl acrylate 2α? Methyl methacrylate
29 blade azobisvaleronitrile
A silicone-containing resin was obtained by reacting 1 part of the above mixture with 67 parts of cellosolve in the same manner as in Example 1, except that the temperature was 135°C.

The nonvolatile content of this resin is 60%, the number average molecular weight is approximately 30,000,
The viscosity was R (25°C) using a Gardner Holtz bubble viscometer. ]) Synthetic styrene of acrylic resin
5 parts ethyl acrylate
85 parts methacrylic acid 1
An acrylic resin was obtained by reacting the above mixture with 67 parts of cellosolve in the same manner as in Example 1, except that the temperature was 135°C.

This resin had a nonvolatile content of 60%, a number average molecular weight of about 20,000, and a viscosity measured by Gardner-Holtz bubble viscometer T (25°C). A resin composition was prepared by mixing 95 parts of (A) and 5 parts of (A). Seven comparative examples 1 a) Synthesis of silicone-containing resin Styrene (1) Adduct of aminopropyltriethoxysilane and glycidyl methacrylate 0.05 parts 2-hydroxypropyl acrylate ■ Part methyl methacrylate
29.95 parts azobisbutyronitrile
A silicone-containing resin was obtained by reacting one part of the above mixture in the same manner as in Example 1, except that cellosolve was used as a solvent and the temperature was 135°C.

This resin had a nonvolatile content of 60%, a number average molecular weight of about 20,000, and a viscosity of W (25° C.) as measured by a Gardner-Holtz bubble viscometer. (b) Synthetic styrene in acrylic resin
4 parts n-butyl acrylate
96 parts tertiary butyl peroctate 0.0
5 parts An acrylic resin was obtained by using the above mixture in the same manner as in Example Cjl, except that Cellosolve was used as the solvent and the temperature was 135°C.

The nonvolatile content of this resin was 60%, the number average molecular weight was about 30,000, and the adhesiveness was P (25°C) as measured by a Gardner-Holtz bubble viscometer. (A) The seal part and the (mouth) gong part were mixed to form a resin composition. Comparative Example 2 (a) Synthesis of silicone-containing resin Styrene 4 parts Adduct of N-methylaminopropyltriethoxysilane and glycidyl acrylate 5 parts 2-ethylhexyl acrylate 8? Methyl methacrylate
11 parts Azobisbutyronitrile 1 part The above mixture was reacted in the same manner as in Example 1 except that the solvent was 67 parts Cellosolve and the temperature was 135°C to obtain a silicone-containing resin.

This resin had a nonvolatile content of 60%, a number average molecular weight of about 20,000, and a viscosity of T (25° C.) as measured by a Gardner-Holtz bubble viscometer. (b) Synthetic styrene in acrylic resin
6CBSn-butyl methacrylate
40 parts Azobisbutyronitrile 1
1 part of the above mixture, 67 parts of cellosolve as a solvent, and 13 parts of temperature as a solvent.
An acrylic resin was obtained by reacting in the same manner as in Example 1 except that the temperature was 5°C.

This resin had a non-volatile content of 60%, a number average molecular weight of approximately 20,000, and a viscosity of R (25°C) measured using a Gardner-Holtz bubble viscometer.4 parts of (a) and 96 parts of (x) were mixed to form a resin composition. did. Experimental Examples Each resin composition obtained in Examples 1 to 3 and Comparative Examples 1 to 2 was polished on a mild steel plate (approximately 150 x 70 x 1 Wf1
) was coated to a dry film thickness of 30μ, and after sufficiently drying, a salt spray test was conducted (JISK5
4OO).

The results after the 100 hour test are shown in Table 1 (adhesion deterioration width, TfWL).

Claims (1)

[Scope of Claims] 1 (a) 0.1 to 50% by weight of at least one silicone-containing monomer represented by the following general formula, ▲ mathematical formula, chemical formula,
There are tables etc. ▼ (In the above formula, R_1 and R_5 are hydrogen atoms or methyl groups, R_2, R_3 and R_4 are alkyl groups having 1 to 4 carbon atoms, and n is an integer of 1 to 12.) Styrene 5 Acrylic copolymer 5 consisting of ~50% by weight and 94.9% by weight or less of (meth)acrylic acid ester
A resin composition for anticorrosive coating, comprising 50 to 95 parts by weight of an acrylic copolymer containing 50 to 50 parts by weight of (b) styrene.