JPH03250016A - Resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition which is excellent in storage stability, is of a one-pack type, is curable at ordinary temperature and is desirable especially for automobile repair coating by mixing a vinyl copolymer having a plurality of siloxy groups with a polyisocyanate resin, a catalyst for dissociating the siloxy groups and a urethane formation catalyst. CONSTITUTION:A resin composition is obtained by mixing a vinyl copolymer having at least two siloxy groups in the molecule [e.g. trimethylsiloxyethyl (meth)acrylate] with a polyisocyanate resin (e.g. tolylene disocyanate polymer), a catalyst for dissociating the above siloxy groups (e.g. p-toluenesulfonic acid) and a urethane formation catalyst (e.g. dibutyltin diacetate). This composition is excellent in storage stability, is good in workability, is of a one-pack type, is curable at ordinary temperature and is desirable especially for automobile repair coating.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel and useful resin composition. More specifically, the present invention relates to a multi-component resin composition comprising a vinyl copolymer in which hydroxyl groups are blocked with two or more siloxy groups.

The resin composition of the present invention is particularly suitable for use as a coating resin composition, especially for automobile repair.

[Conventional technology]

In recent years, two-component paints made from a combination of acrylic polyol and polyisocyanate resin have been widely used in the automotive repair field due to their superior coating performance and ability to harden at room temperature. However, there are various problems due to the two-component type. For example, when mixed with a hardening agent at a painting site, subtle color differences may occur even if the same paint base is used, and there are major drawbacks in terms of workability due to pot life. The combination of an acrylic resin having a grade amino group as a functional group and a polyfunctional epoxy resin has been studied, and some studies have also put it into practice. This system also has major problems in terms of pot life.

By the way, from the viewpoint of a one-component type, it is possible to use an aminoblast system that uses a curing catalyst or an isocyanate prepolymer in the form of an isocyanate prepolymer blocked with an appropriate blocking agent, but both methods require curing at room temperature. is totally inadequate.

[Problem to be solved by the invention]

In this way, as long as conventional techniques are followed, at least from the viewpoint of ease of color matching and painting workability, paints that can be molded, have excellent storage stability, and can be cured at room temperature, among others, The current situation is that it is not possible to provide paints for automobile refinishing, and there is therefore an urgent need for the urgent development of such paints.

To this end, the present inventors have first achieved storage stability over a long period of time, good workability, and
In order to provide a resin composition that can be cured at room temperature, in other words, a one-component resin composition that has excellent stability and good workability, and that can be cured at room temperature, especially a resin composition for automobile repair. In order to provide this, we have begun earnest research.

Therefore, the problem to be solved by the present invention is to provide - excellent stability and good workability;
An object of the present invention is to provide a liquid type resin composition that can be cured at room temperature.

[Means to solve the problem]

However, in order to obtain an acrylic paint that satisfies the above-mentioned requirements, the present inventors have made extensive studies and found that a vinyl copolymer having two or more siloxy groups in one molecule can be used with conventional hydroxyl groups. The present inventors have now completed the present invention by discovering that sufficient stability can be obtained even when used in combination with an isocyanate prepolymer by using it in place of the vinyl copolymer containing it.

That is, the present invention includes, as essential components, a vinyl copolymer having at least two siloxy groups in one molecule;
The object of the present invention is to provide a resin composition comprising a polyisocyanate resin, a dissociation catalyst for the siloxy group, and a urethanization catalyst, and further comprising a water binder if necessary. This is what we are trying to provide.

First, the above-mentioned siloxy group-containing vinyl copolymer refers to one having two or more siloxane groups in one molecule, for example, as represented by the general formula % (1).

As a method for preparing the siloxy group-containing vinyl copolymer, any known and commonly used method can of course be adopted, but usually a siloxy group-containing vinyl monomer and a copolymer thereof are used. Preference is given to methods by copolymerization reactions with possible other monomers.

Among them, only the most representative ones as siloxy group-containing vinyl monomers are listed: trimethylsiloxyethyl (meth)acrylate, trimethylsiloxypropyl (meth)acrylate, and trimethylsiloxybutyl (meth)acrylate. acrylate, trialkylsiloxyalkyl (meth)acrylates such as triethylsiloxyethyl (meth)acrylate, triethylsiloxyprobyl (meth)acrylate, triethylsiloxybutyl (meth)acrylate or tributylsiloxypropyl (meth)acrylate; triphenylsiloxyalkyl (meth)acrylates; or dimethyl tert-butylsiloxyalkyl (meth)R, etc., but of course, in the present invention, the hydrogen atom of the hydroxyl group in the hydroxyl group-containing polymerizable unsaturated monomers is Any compound blocked with a silyl forming agent can be used, so it is not limited to the above-mentioned compounds.

That is, N-methylolated (meth)acrylamide,
β-hydroxyethyl (meth)acrylate with ε-caprolactone added, or polyoxyalkylene glycol (meth)acrylate i, respectively,
This is because silylated materials can also be used.

Next, only typical examples of other monomers that can be copolymerized with the siloxy group-containing vinyl monomer include alkyl (meth) having an alkyl group C+-Czz in the side chain. ) acrylate, cyclohexyl (meth)acrylate or 2-ethoxyethyl (meth)
Various non-functional (meth)acrylates such as acrylate; Various functional group-containing (meth)acrylates such as glycidyl (meth)acrylate; styrene, α
- Aromatic vinyl monomers such as methylstyrene, pt-butylstyrene or vinyltoluene; Vinyl monomers containing amide groups such as (meth)acrylamide;
Cyano group-containing vinyl monomers such as (meth)acrylonitrile; Unsaturated carboxylic acids such as (meth)acrylic acid, maleic acid, fumaric acid, or itaconic acid; Maleic acid or fumaric acid and a C9-C11 monohydric alcohol diesters with [;N,N-dialkylaminoalkyl (meth)acrylates; or phosphoric acid group-containing (meth)acrylates; or fluorine-containing vinyl monomers such as hexafluoropropylene or tetrafluoroethylene. , and even vinyl acetate. These various vinyl monomers can be used alone or as a mixture of two or more, depending on the desired coating performance. However, needless to say, it is not preferable to use a hydroxyl group-containing monomer. In order to obtain these copolymers, known and commonly used methods such as radical polymerization and ionic polymerization are used.

Furthermore, as described above, it is also possible to use a method in which the hydroxyl group-containing vinyl copolymer is obtained and then blocked with a silylating agent such as a trialkyl monochlorosilane compound.

The number average molecular weight Mn of the vinyl copolymer thus obtained is preferably in the range of 1,000 to 40,000. If the Mn of the copolymer is less than 1,000, the coating film performance will not be sufficient;
If it exceeds 40,000, defects are likely to appear in the appearance, gloss, texture, or painting workability of the coating film, which is not preferable.

Next, as the curing agent used in the present invention,
Polyisocyanates that react with the hydroxyl groups produced from the above-mentioned siloxy group-containing vinyl copolymer are used. In particular, the polyisocyanates include aromatic diisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate or xylylene diisocyanate; aliphatic diisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate or trimethylhexane diisocyanate, to mention only representative ones; Diisocyanate; or isophorone diisocyanate, methylcyclohexane-2,4-(or 2,6-) diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate) or 1,3-
In addition to alicyclic diisocyanates such as di(isocyanatomethyl)-cyclohexane, each of these diisocyanates and polyhydric alcohol groups such as ethylene glycol, propylene glycol, neopentyl glycol modi, or trimethylolpropane, and isocyanate groups. Polyester resins with extremely low molecular weight (including oil-modified types) that have functional groups that react with including, ), etc. The blending ratio of these polyisocyanates and the vinyl copolymer is the equivalent ratio of the generated hydroxyl groups to the isocyanate groups: (OH/
NGO) is preferably within the range of 110.2 to 1/3 from the viewpoint of coating film performance. In this case, either a 1-part solution in which the polyisocyanate is blended in advance or a 2-component solution in which the polyisocyanate is blended before coating may be used.

When the composition of the present invention is exposed to the atmosphere, it is hydrolyzed by reaction with moisture in the air to produce hydroxyl groups that can react with the curing agent. For this purpose, it is necessary to use a catalyst to promote this hydrolysis, that is, a siloxy group dissociation catalyst. Acidic catalysts such as esters or phosphoric acid esters containing unsaturated groups, p-)luenesulfonic acid and its amine salts, benzoic acid, trichloroacetic acid, trifluoroacetic acid, and naphthalene disphonic acid and its amine salts, as well as tetraethylammonium Compounds that generate halogen ions, such as fluoride and chloride, are effective. The amount of these catalysts added is 0.001 to 10% by weight, preferably 0.005% by weight based on the vinyl copolymer.
The content is preferably within a range of 8% by weight.

In addition, as the catalyst that promotes the reaction between the generated hydroxyl group and the polyisocyanate as a curing agent, that is, the urethanization catalyst, any of the known and commonly used urethanization catalysts can be used. It is not particularly limited.

Metal salts of carboxylic acids such as alkyl titanate, octylate, dibutyltin dilaurate or lead octylate; or monobutyltin sulfide or dioctyltin mercaptite, to mention only the most representative ones. These include sulfide type or methylcaptide type organic tin compounds.

The amount of these used is 0.001 to 10% by weight based on the vinyl copolymer, preferably o, oos
The content is preferably within a range of 5% by weight.

In addition, the composition of the present invention does not generate hydroxyl groups that can react with a curing agent unless exposed to the atmosphere, so the composition of the present invention can be made into a one-component paint with good stability. . However, in order to ensure long-term storage stability,
All you have to do is capture the amount of moisture that enters for some reason. That is, it can be said that adding a water binder that is reactive with moisture is an effective means to ensure long-term stability. Moreover, there is no problem in mixing this water binder in advance at an early stage of producing the vinyl copolymer. 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 orthoborate such as tributyl orthoborate, triethyl orthoborate; Tetra(substituted) such as tetramethylsilicate, tetraethylsilicate, tetrabutylsilicate, tetra(2-methoxyethyl)silicate or tetra(2-chloroethyl)silicate Simple alkyl silicates; substances with the same effect as the above tetra (substituted) alkyl silicates such as tetraphenyl silicate and tetrabenzyl silicate (hereinafter abbreviated as the simple substance); or glycimer trimer, tetramer, or hexamer of tetraethyl silicate; ethyl silicate; 40"
Hydrolyzed esterified metals such as individual tetra(substituted) alkyl silicates such as (Colcoat product, mixture of tetramer, pentamer and hexamer of tetraethyl silicate), and condensates of the same silicates, Examples include compounds having an isocyanate group, such as phenyl isocyanate, p-chlorophenyl isocyanate, benzenesulfonyl isocyanate, p-trienesulfonyl isocyanate, and isocyanate ethyl methacrylate (NCO group-containing monomer manufactured by Dow Chemical Company, USA).

The amount used is 0.1% based on the vinyl copolymer.
A range of 30% to 30% by weight, preferably 0.5 to 20% by weight is suitable.

The thus obtained resin composition of the present invention can be used as it is as a clear paint, or can be further mixed with a pigment to be used as an enamel paint. Furthermore, various conventional additives such as a leveling agent, an ultraviolet absorber, or a pigment dispersant can be mixed into the composition of the present invention, if necessary.

Further, known and commonly used cellulose compounds, plasticizers, polyester resins, etc. can also be used.

A wide range of curing methods can be used, from drying at room temperature to forced drying at around 70°C, which are used during automobile repair. Optimal curing conditions can be designed according to the combination of

[Example] Next, the present invention will be explained by reference examples, examples, and comparative examples.
Although the layers will be specifically explained, all parts and percentages hereinafter are based on weight unless otherwise specified.

Reference Example 1 [Preparation example of a vinyl copolymer containing a siloxy group] 700 parts of toluene was charged into a four-loaf flask equipped with a stirring device, an inert gas inlet, a thermometer, and a condenser, and the temperature was raised to 110°C. After that, 280 parts of trimethylsiloxyethyl methacrylate, 220 parts of styrene, rSL
methacrylate” (CI manufactured by Mitsubishi Rayon Co., Ltd.)
a monomer mixture consisting of 100 parts of methacrylate with an alkyl group of t = Cl 3, 30 parts of toluene
0 parts and 25 parts of azobisisobutyronitrile were added dropwise over 5 hours. Further, the reaction was carried out at the same temperature for 6 hours, and the nonvolatile content was 50.3%, the viscosity (Gardner viscosity at 25°C; the same applies hereinafter) was P, the number average molecular weight was 12.000, and 0 parts. A target copolymer solution having a value of 38 was obtained.

Reference example 2 (same as above) “Plaxel FM-3J made by Daicel Industries, Ltd., β-
150 parts of the reaction product of [3 moles of ε-caprolactone added to hydroxyethyl methacrylate] and trimethylchlorosilane, 100 parts of styrene, n-
The same procedure as in Reference Example 1 was performed, except that 100 parts of butyl methacrylate, 400 parts of isobutyl methacrylate, 100 parts of n-butyl acrylate, and 150 parts of rSL-methacrylate J were used, and the nonvolatile content was reduced to 50. 8%, the viscosity is I, and the number average molecular weight is 1.
A solution of the desired copolymer having an OH value of 1.000 and an OH value of 8 was obtained.

Reference Example 3 (same as above) 270 parts of triphenylsiloxyethyl methacrylate, 400 parts of styrene, 2 parts of n-butyl methacrylate
00 parts, 130 parts of n-butyl acrylate, and A
Except for using 55 parts of IBN, the same procedure as in Reference Example 1 was carried out to obtain a sample with a non-volatile content of 49.6%, a viscosity of A, a number average molecular weight of 3.500, and a hydroxyl value. A solution of the desired copolymer having a particle size of 18 was obtained.

Reference example 4 (same as above) 135 parts of trimethylsiloxyethyl methacrylate,
A non-volatile content of 50.8% and a viscosity of A solution of the desired copolymer having a number average molecular weight of 15,000 and an OH value of 19 was obtained.

Reference example 5 (same as above) 360 parts of trimethylsiloxyethyl methacrylate,
150 parts of styrene, 42 parts of isobutyl methacrylate
70 parts of "0 parts rSL-methacrylate" and AIBN
By the same operation as in Reference Example 1, except for changing to use 25 parts of
A solution of the desired copolymer was obtained.

Reference Example 6 (Preparation example of vinyl copolymer for control) 300 parts of B-hydroxyethyl methacrylate, 200 parts of styrene, 400 parts of n-butyl methacrylate, rS
100 parts of "L-methacrylate" and 3 parts of butyl acetate
The same procedure as in Reference Example 1 was carried out, except that 00 parts were used, and the non-volatile content was 50.1%, the viscosity was W, the number average molecular weight was 13.000, and the OH number was 45. A control vinyl copolymer solution was obtained.

Reference Example 7 (Same as above) Changed to use 250 parts of triphenylsiloxyethyl methacrylate, 80 parts of β-hydroxyethyl methacrylate, 400 parts of styrene, 140 parts of n-butyl methacrylate, and 130 parts of n-butyl acrylate. Other than that, perform the same operations as in Reference Example 1,
A solution of a control vinyl copolymer having a nonvolatile content of 50.9%, a viscosity of Y, a number average molecular weight of 14,000, and a valence of 0]1 of 35 was obtained.

Examples 1 to 5 and Comparative Examples 1 and 2 Various paints were obtained by blending in a conventional manner according to the blending ratios shown in Table 1.

Next, each paint was spray-coated separately on a zinc phosphate-treated mild steel plate to a dry film thickness of 40 μm, and then forced dry at 60°C for 40 minutes and then left at room temperature for 3 days. Curing conditions (condition ■) of leaving at room temperature for 3 days and/or curing conditions (condition ■) of leaving at room temperature for 3 days and performing “normal temperature drying”
A cured coating film was prepared according to the following.

Various performances of the thus obtained paints and cured coatings were evaluated.

The results are summarized in Table 1.

Note that the evaluation of various performances was performed in the following manner.

Adhesion...When removing 100 dots drawn on the paint film with a size of 1 cm" using cellophane tape, check whether some number (X) of dots remain. , rX/100J.

Xylene rubbing: After rubbing back and forth with lO, the degree of scratches on the surface of the coating film was visually determined.

Humidity resistance: 24℃ at constant temperature and humidity of 50℃ and 98%RH
After holding for 0 hours, changes in the surface of the coating film were visually determined.

Storage stability of paint: Judgment was made based on the change in state after being kept in a constant temperature room at 40°C for one month.

〔Effect of the invention〕

As is clear from Table 1, the resin composition of the present invention has excellent storage stability and can be cured at room temperature.
Moreover, it is known to have an excellent balance of physical properties.

Claims (1)

[Claims] 1. It is characterized by containing a vinyl copolymer having two or more siloxy groups in one molecule, a polyisocyanate resin, a dissociation catalyst for the siloxy groups, and a urethanization catalyst. A resin composition. 2. The resin composition according to claim 1, wherein the vinyl copolymer having two or more siloxy groups in one molecule has a number average molecular weight of 1,000 to 40,000.