JPH01104666A - Thermosetting resin composition - Google Patents

Abstract

PURPOSE:To provide the title novel composition useful for a one-pack coating and composed of a vinyl resin obtained by copolymerizing a glycidyl-containing alpha,beta-ethylenic unsaturated monomer, t-butyl (meth)acrylate and a copolymerizable monomer. CONSTITUTION:The objective composition is composed of a vinyl resin produced by copolymerizing (A) 5-95wt.% of an alpha,beta-ethylenic unsaturated monomer containing glycidyl group [e.g. glycidyl (meth)acrylate], (B) 5-95wt.% of t-butyl (meth)acrylate and (C) 90-0wt.% of other copolymerizable monomer non- reactive with glycidyl group (e.g. 2-hydroxyethyl acrylate).

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a thermosetting resin composition, and more particularly to a novel resin composition for use in a one-component stable thermosetting one-component coating or powder coating. It is.

Prior Art A polymer compound having a glycidyl group, such as a glycidyl methacrylate copolymerized acrylic resin or an epoxy resin,
Thermosetting resin compositions composed of polybasic acids and polyamines are well known and are widely used in coatings and other fields.

In particular, the ester bond obtained by the reaction of a glycidyl group and a carboxylic acid is strong and stable, has excellent weather resistance, chemical resistance, heat resistance, etc., and does not cause coloring, so it is suitable for paint purposes.

However, the reactivity of glycidyl groups and carboxylic acid groups is quite high, and the reaction proceeds easily even at room temperature, so if they are allowed to coexist in a poor solution state, the viscosity increases and gels within a few days.

Therefore, it is necessary to mix a resin or compound containing a glycidyl group and a resin or compound with a carboxyl group immediately before use to create a so-called two-component type product, in which the glycidyl group and the carboxyl group are supported on the same resin, or they are mixed together immediately before use. It is almost impossible to prepare a resin or a group of compounds containing separate groups in a one-part form. In the field of powder coatings, for example, coatings containing glycidyl methacrylate copolymer resin and dicarboxylic acid have been put into practical use.
This is because the above reaction rate is slow because it is a solid phase. However, even in that case, if stored for several months or more, the reaction will gradually proceed, making it impossible to put it into practical use, and in particular, if stored at high temperatures, the reaction will proceed significantly.

Problems to be Solved by the Invention Although the invention ultimately utilizes the desired reaction between glycidyl groups and carboxyl groups, it is not possible to use a one-component paint;
Alternatively, there is a demand for a resin composition that can be prepared into a powder coating that can be stored stably for a long period of time and that can also be used as a two-component coating, and it is an object of the present invention to meet such problems.

Means for Solving the Problems According to the present invention, the above objects are (a) 5 to 95% by weight of glycidyl group-containing α,β-ethylenically unsaturated monomers (b) t-butyl acrylate or t-butyl 5 to 95% by weight of methacrylate (e) Thermosetting resin composed of a vinyl resin obtained by copolymerizing glycidyl groups and 90 to 0% by weight of other non-reactive copolymerizable monomers [Achieved by H type resin composition] be given That is, according to the present invention, a glycidyl group-containing α,β-ethylenically unsaturated monomer,
Provided is a thermosetting resin composition consisting solely of a vinyl resin copolymerized with t-butyl acrylate or monobutyl methacrylate and other copolymerizable monomers that do not react with glycidyl groups.

In terms of composition of the vinyl resin according to the present invention, among the (a) glycidyl group-containing α,β-ethylenically unsaturated monomers, for example, glycidyl acrylate, glycidyl methacrylate, etc. are most representative, but for example, 2 - Glycidyloxyethyl (meth) obtained by the reaction of hydroxyethyl (meth)acrylate and epichlorohydrin
- Any compound having a polymerizable ethylene bond and a glycidyl group, such as acrylate, is preferably used. The glycidyl group-containing α,β-ethylenically unsaturated monomer is selected within the range of 5 to 95% by weight of the total monomers, and (b) the monomer t-butyl acrylate or t-
Butyl methacrylate is also selected within the range of 5 to 95% by weight.

The vinyl resin of the present invention may be composed only of the monomers (a> and (b) above, and if desired, the vinyl resin may have a
Other copolymerizable monomers that are non-reactive with the glycidyl group can also be included as monomer (c) in a weight percent ratio.

In the present specification, the term "non-reactive with glycidyl groups" refers to temperatures ranging from room temperature to below the baking temperature, for example from 150 to 160°C.
It means a group that does not react with a glycidyl group at C or less, and therefore, polymerizable monomers containing a phenolic hydroxyl group, an amino group, an aldehyde group, a carboxyl group, etc. are excluded from the monomer (c). Typical monomers (c) are roughly classified into the following: (1) Hydroxyl group-containing monomers such as 2-hydroxyethyl acrylate, hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, and hydroxybutyl. Acrylate, hydroxybutyl methacrylate, allyl alcohol, methalyl alcohol, etc.

(a Alkyl acrylate or methacrylate such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, 2-ethylhexyl acrylate, etc.)

(3) Polymerizable amides such as acrylamide and methacrylic acid amide.
- 4) Polymerizable nitriles such as acrylonitrile and methacrylatetrile.

(5) α-olefin For example, ethylene, propylene, etc.

(6) Vinyl compound For example, vinyl acetate, vinyl propionate, etc.

+71 di-engine compound For example, butadiene, isoprene, etc.

(a) Polymerizable aromatic compounds such as styrene, α-methylstyrene, vinyltoluene, t-butylstyrene, etc.

These monomers may be used alone or in combination.

Polymerization can be carried out by conventional emulsion polymerization, NAD polymerization, solution polymerization, bulk polymerization, etc., but it goes without saying that consideration should be taken to avoid decomposition of the monomer having a glycidyl group. Examples of the initiator include lauroyl peroxide, di-t-butyl peroxide, benzoyl peroxide, t-butyl perbenzoate, t-butyl peroxy-2-ethylhexanoate, azobisisobutyronitrile, 2. 2'-azobis(2,4-dimethylvaleronitrile) and the like are used.

In this way, the resin of the present invention has glycidyl groups and t-
Characterized by pendant butyl ester groups6
The present inventors believe that such resins can be used at room temperature to 150 to 160°C.
It is stable within the high temperature range of about 170℃, and the normal baking temperature is 170℃.
It was discovered that when the temperature exceeds ℃, t-butyl ester is thermally decomposed, generating isobutene gas and carboxyl groups, and this carboxyl group causes thermosetting by reaction with glycidyl, forming a tough coating film. The present invention has been completed by determining the composition ratio of each vinyl resin based on the thermal decomposition of t-butyl ester, thermosetting reaction, and coating film performance. The vinyl resin of the present invention is novel in that a specific proportion of glycidyl groups and t-butyl ester groups are intentionally pendant with the intention of thermal decomposition and thermosetting at baking temperatures.
Thus, the resin composition of the present invention can be used as it is as a resin vehicle for a single-residue type thermosetting paint, and is also useful as a binder resin for a powder paint. Of course, if desired, the resin composition of the present invention can be further combined with a compound having two or more active hydrogens in the molecule, and used as a two-component thermosetting resin composition.

The present invention will be explained below with reference to Examples. In the following, unless otherwise specified, parts and percentages are by weight.

Example 1 70 parts of xylene and 20 parts of n-butanol were charged into a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen gas introduction tube, and a dropping funnel, and the mixture was heated to 100°C while introducing nitrogen gas.
After heating, the following mixture was added dropwise at a constant rate over 3 hours using a dropping funnel.

Mixture A Glycidyl methacrylate 5 parts t-butyl methacrylate 5 parts Methyl methacrylate
45 parts 1-butyl acrylate 45 parts t-butylperoxy-2-ethylhexanoate
After dropping 1 part of the above mixture, the mixture was kept warm for 30 minutes, and a mixed solution of 0.5 parts of t-butylperoxy-2-ethylhexanoate and 10 parts of xylene was added dropwise at a uniform rate over 30 minutes.

After completion of the dropwise addition, the mixture was aged at 100° C. for 3 hours and then cooled to obtain resin solution A-1.

Examples 2 to 12 and Comparative Examples 1 to 2 Reactions were carried out in the same manner as in the same reaction vessel as in Example 1 with the compositions shown in Table 1, and resin solutions A-2 to A-12 and B-
1 to B-2 were obtained 6 Examples 13 to 26 and Comparative Examples 3 to 4 Resin solutions A-1 to A-12 and B-1 to B obtained in Examples 1 to 12 and Comparative Examples 1 to 2 -2 was coated on a tin plate using a bar coater and heated at 170°C and 200°C.
℃ for 30 minutes each. After cooling to room temperature, a rubbing test was performed with xylene and acetone. The results are shown in Table 2. In addition, each resin solution was heated at 40°C for 1
Table 3 shows the results after storage for several months.

Comparative Example 5 Resin solution C-1 obtained by reacting a mixture with the following composition in the same manner as in Example 1 was mixed with resin solution B-2 obtained in Comparative Example 2 in equal amounts. The mixed solution was applied onto a tin plate using a bar coater, and heated at 170°C and 200°C.
Bake for 30 minutes each. After cooling to room temperature, a rubbing test was performed with xylene and acetone. The results are shown in Table 2.

Furthermore, Table 3 shows the results of storing each resin solution at 40° C. for one month.

Composition of resin solution C-1: xylene 80 parts n-butanol 20 parts methacrylic acid
30 parts methyl methacrylate
40 parts n-butyl acrylate 30
Part t-7 tilveroxy-2-I thylhexanoate
1.5 parts; 2 and 2' 1. Rubbing test Soak gauze in xylene or acetone and visually judge the condition of the film after moving it back and forth on the film surface 100 times.

O: Good with no change Δ: Film whitening ×: Film elution 2, storage stability The resin solution was stored at 40° C. for one month, and the change in viscosity after storage was measured.

Claims (1)

Scope of Claims: (a) 5-95% by weight of α,β-ethylenically unsaturated monomer containing a glycidyl group (b) 5-95% by weight of t-butyl acrylate or t-butyl methacrylate (c) Glycidyl group A thermosetting resin composition comprising a vinyl resin obtained by copolymerizing 90 to 0% by weight of another non-reactive copolymerizable monomer.