JPH0196264A - Coating resin composition - Google Patents

Abstract

PURPOSE:To obtain a coating resin composition of one-pack and self-curing type, having excellent storage stability and low-temperature curing properties, comprising a specific vinyl copolymer containing siloxane group and isocyanate group. CONSTITUTION:The aimed composition comprising a vinyl copolymer obtained by copolymerizing (A) 99-1wt.% vinyl monomer containing a polymerizable unsaturated double bond and siloxy group in one molecule with (B) 1-99wt.% vinyl monomer containing a polymerizable unsaturated double bond and isocyanate group in 1mol. and optionally (C) 0-98wt.% copolymerizable vinyl monomer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a new and useful coating resin. A vinyl monomer having an unsaturated double bond and a siloxy group, a vinyl monomer (B) each having at least one polymerizable unsaturated double bond and an isocyanate group in one molecule, and if necessary, the above-mentioned A vinyl copolymer obtained by copolymerizing monomers (A) and (B) with another copolymerizable vinyl monomer (C), the copolymer comprising monomer components (
A) The present invention relates to a self-curing coating resin composition in which a hydroxyl group generated by decomposition of an introduced siloxy group is reactive with an isocyanate group introduced from a monomer component (B).

[Problems to be Solved by the Prior Art and the Invention] In recent years, the use of glass for outer panel parts, etc. has been rapidly progressing in the automobile industry and the home appliance industry.

Conventionally, when the material is a steel plate, a baking-liquid type paint using an aminoplast-based curing agent as a main ingredient such as an acrylic resin or an alkyd resin has usually been employed. However, when the material becomes plastic,
Some materials have a low heat resistance temperature, and for plastics, conventional baking has a high baking temperature of 140 to 150℃.
It is inappropriate to use liquid paints. Therefore, room temperature curing type and low temperature curing type paints are being considered or partially adopted for plastics. These paints include urethane paints that are a combination of polyol-type resins and isocyanate prepolymers, nixy paints that are a combination of acrylic resins with tertiary amino groups and polyfunctional epoxy resins, and low-temperature curing catalysts such as para-toluenesulfonic acid. There are paints that cure with aminoplast. However, among these paints, both urethane paints and epoxy paints that can be cured at room temperature are two-component paints. It has major drawbacks in terms of workability such as work life.゛On the other hand, aminoplast curing paints that use low-temperature curing catalysts are one-component because the main ingredient and curing agent are mixed in advance.
Although the baking temperature is lower than that of conventional products, it is only about 110°C, making it unsuitable for use in plastics.

In addition, if you use an isocyanate prepolymer blocked with an appropriate blocking agent, a one-component type 7? Although it is a 1J all type resin-blocked isocyanate prepolymer curing system, the dissociation temperature of the blocking agent is currently as high as 150° C. or higher, so it is difficult to call it a room temperature or low temperature curing resin system. As mentioned above, in the industry, from the viewpoint of painting workability, material conversion, and energy saving, - deep type with excellent long-term storage stability, various physical properties, weather resistance, etc. at room temperature or low temperature below 110℃ The current situation is that there is a need for the immediate development of curable resin paints.

[Means for solving problems]

However, the inventors of the present invention have made extensive studies to obtain a vinyl paint that meets the above-mentioned requirements, and have found that a vinyl monomer having at least one polymerizable unsaturated double bond and at least one siloxy group in each molecule has been developed. and a vinyl monomer each having at least one polymerizable unsaturated double bond and all isocyanate groups in one molecule, it was discovered that a copolymer obtained by using a vinyl monomer each having at least one polymerizable unsaturated double bond and all isocyanate groups can surprisingly improve these required performances. , we have completed the present invention.

That is, the present invention relates to a coating resin, and this coating resin contains vinyl monomers (A) 99 to 99, each having at least 41 polymerizable unsaturated double bonds and siloxy groups in one molecule. 1 to 99 parts by weight of the vinyl monomer (B) each having at least one polymerizable unsaturated double bond and isocyanate group in one molecule, and if necessary, the monomer (4), ( B
) and a copolymerizable vinyl monomer (C) having a weight ratio of 0 to 98%.

In the coating resin of the present invention, the siloxy group introduced into the vinyl monomer (A), which is one of the constituent components of the resin, is reacted with moisture in the air to generate a hydroxyl group, and the generated hydroxyl group is reacted with the isocyanate group introduced from the other component, the vinyl monomer (B), to form a strong coating film, which has excellent storage stability and low-temperature curability. A one-component self-curing coating resin can be provided.

Here, the vinyl monomer (A) is a vinyl monomer containing at least one polymerizable unsaturated double bond in each molecule and a siloxy group typically bonded to a carbon atom represented by the following formula. It is a type monomer.

-0-8i-R2 The method for producing the above vinyl monomer (A) is not particularly limited; phenylchlorosilane,
Refers to those obtained by reacting triallylchlorosilane, dialkylchlorosilane, dialkyldichlorosilane, dialkylhydrosilane, etc. with hydroxyl group-containing vinyl monomers as listed below, and among them, trimethylsiloxy is a typical example. Ethyl (meth)acrylate, trimethylsiloxypropyl (meth)acrylate,
Examples include trimethylsiloxybutyl (meth)acrylate, triethylsiloxyethyl (meth)acrylate, trimethylsiloxypropyl (meth)acrylate, and triphenylsiloxyalkyl (meth)acrylate.

These can be used alone or as a mixture of two or more.

The hydroxyl group-containing vinyl monomers used in the production of the vinyl monomer (A) mentioned above include β-hydroxyethyl (meth)acrylate, β-hydroxyglobil (meth)acrylate, and β-hydroxybutyl (meth)acrylate. ) hydroxyalkyl such as acrylate/l
/(meth)acrylates or N-methylolated (meth)acrylamide; β-hydroxyethyl (meth)acrylate with ε-cagrolatatone added; polypropylene glycol monomethacrylate polyethylene glycol monomethacrylate; (meth)acrylic acid, maleic acids, unsaturated carboxylic acids such as fumaric acid or itaconic acid, and glycidyl esters of branched fatty acids, monoglycidyl esters of monohydric caldic acids such as glycidyl octylate or glycysol ester of coconut oil fatty acids, or butyl glycidyl ether. Typical examples include adducts with monoepoxy compounds such as monoglycidyl ethers, and these hydroxyl group-containing vinyl monomers can be used alone or in a mixture of two or more.

The amount of the vinyl monomer cA) used is preferably 99 to 1 weight, preferably 90 to 5 weight. If the amount is less than 1 weight, no effect can be expected from the monomer.

Next, the other vinyl monomer (B) constituting the coating resin of the present invention is a vinyl monomer each having at least one polymerizable unsaturated double bond and an isocyanate group in one molecule.

Typical examples include isocyanate ethyl (meth)acrylate, isocyanate globil (meth)acrylate, isocyanate butyl (meth)acrylate, vinyl isocyanate, impropenyl isocyanate, and 2-hydroxyethyl (meth)acrylate with difunctional isocyanate. 1 mo A/: Examples include isocyanate group-containing (meth)acrylate monomers obtained by addition at 1 mole. Typical difunctional isocyanates that can be used in this case include aromatic diisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate or xylylene diisocyanate; aliphatic diisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate or trimethylhexane diisocyanate; Isophorone diisocyanate, methylcyclohexane-2,
4-(or 2.6-) diisocyanate, 4,4
Examples include alicyclic diisocyanates such as '-methylenebis(cyclohexyl isocyanate) and 1,3-di(isocyanatemethyl)-cyclohexane.The vinyl monomer (B) can be used alone or in a mixture of two or more.

The amount of vinyl monomer (Bl) used is preferably 1 to 99% by weight, preferably 5 to 90% by weight, and 1 to 1% by weight.
If the amount is less than %, no effect of the monomer can be expected.

Typical vinyl monomers (C) copolymerizable with the vinyl monomers (A) and (B) include alkyl (meth)acrylates having 1 to 22 carbon atoms, styrene, vinyl toluene, t-butylstyrene, α-methylstyrene, glycidyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, (meth)acrylonitrile, cyclohexyl (meth)acrylate, maleic acid or fumaric acid and monovalent C1 to C48 Diesters with alcohols, N,N-dialkylaminoalkyl (meth)acrylates, or phosphoric acid group-containing (meth)acrylates, fluorine-containing vinyl monomers such as vinyl acetate, hexafluoropropylene, and tetrafluoroethylene, etc. be.

These vinyl monomers (a) can be used alone or as a mixture of two or more types depending on the desired coating performance, and the amount used is O to 98 weight i-4.

In addition, in the coating resin of the present invention, as described above (N, (B)
) and (Q), as well as the hydroxyl group (-OH) generated from the vinyl monomer (A) and the isocyanate group (-NGO) of the vinyl monomer (B).
The ratio during curing with OH/NCO = 110.2 to 1/
It is preferable to set the range to 3 (half amount ratio).

The vinyl copolymer of the present invention can be obtained by a known method using the monomers listed above, typically a solution polymerization method using a radical generator. As the radical generator used during polymerization, any of those commonly used in the polymerization of vinyl monomers can be used, but representative examples include azobisisobutyronitrile, Examples of solvents include aromatic hydrocarbons such as toluene or xylene; acetate esters such as ethyl acetate, butyl acetate or cellosolve acetate; methyl ethyl ketone or Ketones such as methyl isobutyl ketone can also be used.

If necessary, commonly used chain transfer agents such as mercaptans, α-methylstyrene and diintene can also be used.

The coating resin of the present invention thus obtained has a number average molecular weight (
Mn) is preferably in the range of 500 to so, ooo.

If the Mn of the resin is less than 500, the physical properties of the coating film may not be sufficient, and the hydroxyl value generated after trialkylsiloxy groups, etc. of the resin are liberated in an attempt to achieve the physical properties of the coating film. (Hereinafter, this will be referred to as "r OH value").If the value is increased, the coating film will become brittle, which is not preferable.
On the other hand, when it exceeds 50,000, defects are likely to appear in the appearance, gloss, texture, or painting workability of the coating film, which is not preferable.

When the coating resin of the present invention is exposed to the atmosphere, the cisyloxy group is hydrolyzed by reaction with moisture in the air, and reacts with the isocyanate group in the resin to produce a hydroxyl group.

Promote this hydrolysis.

In order to further enhance the curing performance of the resin of the present invention and enable it to be cured even at low temperatures of 100° C. or lower, it is preferable to use a catalyst.

Such catalysts include phosphoric acid, phosphoric esters, phosphorous esters, p-toluene, sulfonic acids and their amine salts, benzoic acid, and trichloroacetic acid.

Acidic catalysts such as trifluoroacetic acid, naphthalene disulfonic acid and its amine salts, ethylenediamine, N-β-aminoethyl-r-aminoglopyltrimethoxysilane, butylamine, diptylamine.

Amines such as t-butylamine, hexylamine, triethylamine, alkali catalysts such as potassium hydroxide, lithium hydroxide, sodium hydroxide, alkyl titanates,
Metal salts of caldic acid such as octylate, diptyltin silacrate, and lead octylate; sulfide type and mercaptide type organic tin compounds such as motuptyltin sulfide and dioctyltin mercagutite; tetraethylamsonium fluoride; cesium fluoride, etc. Compounds that generate fluorine ions are effective. The amount of these curing catalysts added is 0.001 to 10% by weight, preferably 0.001% to 10%, preferably 0%
．． It is best to use a weight of 005 to 8.

Furthermore, since the resin of the present invention does not react with a curing agent to form hydroxyl groups unless exposed to the atmosphere, it is possible to obtain a one-component coating composition with good stability. However, in order to ensure long-term storage stability, it is sufficient to trap trace amounts of moisture that enter for some reason. That is, adding an ice binder that is reactive with moisture ensures long-term stability. Further, this water binder may be mixed into the coating resin at the initial stage of production. Examples of water binding agents reactive with moisture include trialkyl orthoformates such as trimethyl orthoformate, triethyl orthoformate, and tributyl orthoformate; trialkyl orthoacetates such as trimethyl orthoacetate, triethyl orthoacetate, and tributyl orthoacetate Trialkyl orthoborates such as tributyl orthoborate and triethyl orthoborate; Tetra(substituted) such as tetramethylsilicate, tetraethylsilicate, tetrabutylsilicate, tetra(2-methoxyethyl)silicate or tetra(2-chloroethyl)silicate Single alkyl silicates; Substances with the same effect as the above-mentioned tetra(f-substituted) alkyl silicates such as tetraphenyl silicate and tetrabenzyl silicate (hereinafter abbreviated as the same simple substance); or dimers, trimers, tetramers, hexamers, and oxides of tetraethyl silicate. Hydrolyzable ester compounds such as individual tetra(fi-substituted)alkyl silicates listed above, such as mixtures of tetramers, pentamers, and hexamers of tetraethyl silicate, and condensates of the same silicates, and phenyl isocyanate. ), p-chlorophenyl isocyanate, benzenesulfonyl isocyanate, p-trienesulfonyl isocyanate, isocyanate ethyl methacrylate, and other compounds having an isocyanate group.

The amount used is 0.1 to 30% by weight, preferably 0.5 to 20% by weight, based on the coating resin.

The thus obtained coating resin of the present invention can be used not only in the form of a solution but also in the form of a non-aqueous dispersion system or in the form of a powder. It can also be used in a wide variety of applications for pre-coating metals, including automobiles, home appliances, and building exteriors, but its effectiveness is especially noticeable in areas where liquid foam requires storage stability. .

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 1 300 parts of trimethylsiloxyethyl methacrylate,
100 parts of styrene, 230 parts of isocyanate ethyl methacrylate, 270 parts of n-butyl methacrylate, and SL-methacrylate (C12 manufactured by Mitsubishi Rayon ■)
200 parts of a monomer mixture consisting of 100 parts of methacrylate having an alkyl of ~C13, 500 parts of toluene, 200 parts of isobutyl acetate, 5 parts of azobisisobutyronitrile (AIBN) and t@, rt-butylper Benzony) (t-nPB) was charged into a four-way flask equipped with a stirrer, an inert gas inlet, a thermometer, and a condenser and held at 90°C for 1 hour, and then heated to 115°C over 30 minutes. The temperature was raised to ℃, and at the same temperature, 800 parts of the remaining monomer mixture, 300 parts of isobutyl acetate, and t-
A mixture consisting of 10 parts of BPB and parts of AIBNS is maintained to have a non-volatile content of 50.1% and a particle size (Gardner viscosity at 25°C; the same applies hereinafter) 22-2. A resin solution (1) having a number average molecular weight of 12,000 was obtained.

Reference example 2 3 to 1 mole of β-human 90xethyl methacrylate
Reaction product 2 of hydroxyl group-containing vinyl monomer with mole of C-cabrolactone added and trimethylchlorosilane
50 parts, 100 parts of styrene, 175 parts of n-butyl methacrylate, 174 parts of isobutyl methacrylate, n
-100 parts of butyl acrylate, SL-methacrylate is.

By the same operation as in Reference Example 1, except that 51 parts of methacryloyl isocyanate were used, a non-volatile content of 49.8%, a viscosity of S-T, and a number average molecular weight of 1300 were obtained.
A resin solution (2) of 0 was obtained.

Reference Example 3 250 parts of triphenylsiloxyethyl methacrylate, 400 parts of styrene, 10 parts of n-butyl methacrylate
0 parts, n-butyl acrylate 54 parts, and isocyanate butyl methacrylate 196 parts.
．． 9. A resin solution (3)t having a viscosity of 2-21 and a number average molecular weight of 1300 was obtained.

Reference Example 4 The same operation as in Reference Example 1 except that 200 parts of trimethylsiloxyethyl acrylate L/-), 400 parts of methyl methacrylate, 235 parts of n-butyl methacrylate, and 165 parts of isocyanate ethyl methacrylate were used. -Non-volatile content 50.3%, viscosity z2
-23, resin solution with number average molecular weight 13000 - (4)
I got it.

Example 1 1.0 part of p-toluenesulfonyl isocyanate was added to 100 parts of the resin solution-m obtained in Reference Example 1.
-93J (manufactured by Ishihara Sangyo ■, rutile type titanium oxide) 20
The mixture was mixed into a paint according to a conventional method, spray-painted on a zinc phosphate-treated steel plate, and baked at 110°C for 20 minutes. After baking, it was left at room temperature for 3 days, and then a physical property test was conducted.

Gloss (60 parts reflectance) 92, pencil hardness F, installation property (removal of cellophane tape) 100/100, alkalinity (5% NaOH, 24 hours), acid resistance (
5% H2SO4, 24 hours), no abnormalities were observed. Furthermore, the storage stability of the paint was also determined, and no gluing occurred after it was left at room temperature for 3 months.

Examples 2 to 6 In order to evaluate various physical properties of the resin solutions obtained in each reference example, the compositions listed in Table 1 were made into paints according to the conventional coating method, and then the paints shown in the table were made into paints. We also conduct physical property tests on each item. The results are summarized and shown in the same table.

〔Effect of the invention〕

The coating resin of the present invention is a self-curing resin that has excellent low-temperature curability and excellent storage stability. It is also excellent.

Claims (1)

[Claims] Vinyl monomer (A) each having at least one polymerizable unsaturated double bond and siloxy group in one molecule
99 to 1% by weight, 1 to 99% by weight of a vinyl monomer (B) each having at least one polymerizable unsaturated double bond and isocyanate group in one molecule, and further, if necessary, the monomer (A). , (B) and 0 to 98% by weight of a copolymerizable vinyl monomer (C).