JP2712425B2 - Curable resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a novel and useful curable resin composition. More specifically, a resin composition comprising a specific base resin component and a curing agent component further comprises a specific organic phosphorus-containing compound as a curing accelerator component. And an excellent curable resin composition.

The composition of the present invention having such contents can be mainly applied to a wide range of uses such as paints, adhesives or sealants.

[Conventional technology]

In recent years, acrylic lacquers or polyisocyanate-curable urethane paints have been widely used as cold-drying paints with good weather resistance, but the former acrylic lacquers have the advantage of being low in price, but crosslinked paints Film properties are inferior in comparison. On the other hand, the latter case has drawbacks in terms of toxicity or cost due to the isocyanate compound, and it is hard to say that all are preferable. Therefore, development of a new curing system is desired.

The present inventors have conducted intensive studies in view of the actual situation as described above. As a result, as disclosed in JP-A-59-56423 and JP-A-59-142220, a resin composition having room temperature curability and high performance is disclosed. Invented something.

Such a resin composition comprises a vinyl polymer (a) containing a carboxylic anhydride group and, if necessary, a carboxyl group.
-1) and a compound (a-2) having both a group having an active hydrogen capable of reacting with one carboxylic anhydride group and a tertiary amino group in one molecule. It is a room-temperature-curable resin composition comprising the primary amino group-containing vinyl copolymer (I) and a polyepoxy compound as essential components. On the other hand, although the method for introducing a tertiary amino group into a vinyl copolymer is different from that of the above resin composition, it was disclosed in JP-A-52-76338 as a resin composition using a polyepoxy compound as a curing agent. As described above, there is a resin composition having room temperature curability. As such a resin composition,
(1) 0.2-30% by weight of a basic nitrogen-containing acrylic monomer, (2) 35-99.8% by weight of an ester of (meth) acrylic acid and an aliphatic monohydric alcohol or a mixture thereof,
(3) Others A vinyl copolymer comprising 0 to 60% by weight of a copolymerizable monomer, that is, a tertiary amino group-containing vinyl copolymer (II) mixed with a polyepoxy compound. As described above, these resin compositions are new and have room temperature curability. However, when such a tertiary amino group and a resin composition in the form of crosslinking by an epoxy compound are put to practical use as a paint, not only does it yellow when dried, especially when heated and dried, but also at low temperatures. It turned out that it had a disadvantage that it was inferior in curability.

That is, there is a defect that the performance of the cured coating film at a low temperature, which is a use condition in winter and cold regions, is insufficient.

[Problems to be solved by the invention]

For this reason, in order to use the above-mentioned resin composition suitably as a resin composition for paints, it is necessary to improve the curability at low temperatures.

In view of the above-mentioned various disadvantages in the related art, the present inventors provide a curable resin composition in which both hot yellowing during drying of a coating film and low-temperature curability are improved. As a result of intensive studies, the use of a specific organic phosphorus-containing compound as a curing accelerator makes it possible to obtain a resin composition comprising a tertiary amino group-containing vinyl copolymer and a polyepoxy compound with excellent low-temperature curability. And a resin composition capable of giving an excellent cured product which is free from yellowing during drying of a coating film, particularly during heating and drying, and which can be obtained. Thus, the present invention has been completed.

[Means for solving the problem]

That is, the present invention comprises, as essential components, a vinyl copolymer (A) having at least one tertiary amino group in one molecule and a polyepoxy compound (B) as a base resin component and a curing agent component. At least one compound (C) selected from the group consisting of organic trivalent phosphonium salts, organic trivalent phosphines, and organic trivalent phosphites as a curing accelerator component with respect to the resin composition comprising With respect to the vinyl copolymer (A), from 0.01 to 10
It is an object of the present invention to provide a curable resin composition which is excellent in low-temperature curability and heat-resistant yellowing of a coating film.

Here, a vinyl copolymer having at least one tertiary amino group in one molecule, which is one of the essential constituent components of the composition of the present invention and serves as a base resin component in the composition of the present invention ( Examples of A) include the following.

First, as one example, a monomer having an acid anhydride group such as maleic anhydride or itaconic anhydride as disclosed in JP-A-59-56423 and JP-A-59-142220. Body and, if necessary, acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid or fumaric acid; monoalkyl maleate, monoalkyl fumarate or monoalkyl itaconate; or β-hydroxyethyl ( Meta)
A monomer having a carboxyl group such as an adduct of a nitrile monomer having a hydroxyl group such as acrylate and a polycarboxylic anhydride such as succinic anhydride or trimellitic anhydride, and further, each of these monomers A vinyl copolymer obtained by copolymerizing another vinyl monomer having copolymerizability can be used. Hereinafter, this is referred to as a copolymer (a
Abbreviated as -1).

If only typical examples of such other vinyl monomers having copolymerizability are given, methyl (meth)
Various (meth) acrylic acids such as acrylate, ethyl (meth) acrylate, n-, iso- or tert-butyl (meth) acrylate, lauryl (meth) acrylate, benzene (meth) acrylate or cyclohexyl (meth) acrylate A) alkyl or aralkyl esters or alkoxyalkyl (meth) acrylic esters such as ethoxyethyl (meth) acrylate; dialkyl esters of unsaturated dibasic acids such as itaconic acid, maleic acid or fumaric acid;
Aromatic unsaturated hydrocarbons such as styrene, α-methylstyrene or vinyltoluene; “Biscoat 8F, 8F
M, 3F, 3FM "(a fluorine-containing ((meth) acrylic monomer) manufactured by Osaka Organic Chemical Co., Ltd.) or (per) fluoroalkyl group-containing vinyl monomers such as perfluorocyclohexyl (meth) acrylate; mono [( (Meth) acryloyloxyethyl] acid-containing vinyl monomers such as acid phosphate; vinylethoxysilane, α- (meth) acryloyloxypropyltrimethoxysilane,
Trimethylsiloxyethyl (meth) acrylate, "KR
Silicon-based monomers such as "-215" or "X-22-5002" (all manufactured by Shin-Etsu Chemical Co., Ltd.);
-37 "or" LA-82 "(both manufactured by Adeka Argus Chemical Co., Ltd., respectively, a polymerizable ultraviolet absorber monomer or light stabilizer monomer); or vinyl acetate,
Vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, (meth) acrylonitrile, (meth) acrylamide, diacetone acrylamide, N, N-dimethylacrylamide, N-vinylpyrrolidone, and the like. A polyester resin having an unsaturated bond (including an oil-modified type) and a vinyl copolymer can also be used in the same manner.

And the amount of the monomer having an acid anhydride group as described above and the carboxyl group-containing monomer used as required, the curability, water resistance and alkali resistance, the former is 1 to 20 weight %, The latter is suitably in the range of 0 to 15% by weight, while the amount of the copolymerizable vinyl monomer as described above is suitably in the range of 99 to 65% by weight. is there.

The vinyl copolymer (a-1) can be prepared using any of the above-listed monomers by any known and commonly used method, but the solution radical polymerization method is most preferable. Preferably, it includes aromatic hydrocarbons such as toluene and xylene; aliphatic hydrocarbons such as hexane, heptane and cyclohexane; ethyl acetate, butyl acetate;
An ester solvent such as cellosolve acetate; or a ketone solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, and a known and commonly used polymerization initiator such as an azo or peroxide compound, are prepared by a conventional method. The polymerization may be performed by

At this time, it is also possible to use a molecular weight regulator such as mercaptans such as t-dodecyl mercaptan, lauryl mercaptan, alkyl thioglycolate, and β-mercaptopropionic acid, and α-methylstyrene dimer.

Next, the vinyl copolymer (a-1) is reacted with a compound (a-2) having both a group having an active hydrogen group capable of reacting with a carboxylic anhydride group in the polymer and a tertiary amino group. Then, a vinyl copolymer (A) having at least one tertiary amino group in one molecule as a base resin of the composition of the present invention is obtained.

The above-mentioned compound (a-2) having both a group having an active hydrogen capable of reacting with a carboxylic anhydride group (hereinafter abbreviated as an active hydrogen-containing group) and a tertiary amino group is defined as the active hydrogen-containing group. A compound having each group such as a hydroxyl group, a primary or secondary amino group, or a thiol group is referred to. Among them, the most preferred compounds are alcohols having a tertiary amino group and tertiary amino groups. And primary or secondary amines having the formula: Among them, typical examples of the former amino alcohols include adducts of secondary amines and epoxy compounds. Typical examples of the secondary amines used herein include dimethylamine, diethylamine, and dipropylamine. There are amine, dibutylamine, ethyleneimine, morpholine, piperazine, piperidine, pyrrolidine, etc., and further contains a secondary amino group obtained by addition of a primary amine such as methylamine, ethylamine, butylamine and a mono or polyepoxy compound. There are amino alcohols and the like, while typical epoxy compounds include ethylene oxide, propylene oxide,
Butylene oxide, dodecene oxide, styrene oxide, cyclohexene oxide, butyl glycidyl ether or phenyl glycidyl ether; or p-te
Monoepoxy compounds such as rt-butyl benzoic acid glycidyl ester or "Cardura E10" (glycidyl ester of branched fatty acid manufactured by Ciel, The Netherlands); or ethylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexane Polyglycidyl ethers of polyhydric alcohols such as diol diglycidyl ether, diglycidyl ether of bisphenol A or triglycidyl ether of glycerin; diglycidyl esters of phthalic acid, diglycidyl esters of isophthalic acid or diglycidyl esters of adipic acid Polyglycidyl esters of polycarboxylic acids; or diglycidyl ether type epoxy resins of bisphenol A or bisphenol F, novolak type epoxy resins Or polyepoxy compounds such as various epoxy resins such as a hydantoin ring-containing epoxy resin, and further, glycidyl ester ether of p-oxybenzoic acid or various vinyl copolymers having an epoxy group in a side chain. .

Representative examples of the tertiary amino group-containing alcohols obtained by reacting such secondary amines with an epoxy compound include dimethylaminoethanol, diethylaminoethanol, di-n-propylaminoethanol, diisopropylaminoethanol, and diisopropylaminoethanol. n-butylaminoethanol, dimethylaminobutanol, dimethylaminohexanol, N- (2-hydroxyethyl) morpholine,
N- (2-hydroxyethyl) piperidine, N- (2-
(Hydroxyethyl) pyrrolidine, N- (2-hydroxyethyl) aziridine, N, N-dimethyl-2-hydroxypropylamine, N, N-diethyl-2-hydroxypropylamine, triethanolamine or tripropanolamine. Examples of the tertiary amino group-containing alcohols include, in addition to those listed above, amine alcohols such as ethanolamine and propanolamine, and dimethylamineethyl (meth) acrylate and diethylaminoethyl (meth) acrylate. An adduct with a (meth) acrylate monomer having a tertiary amino group, or a hydroxyl group-containing monomer such as β-hydroxyethyl (meth) acrylate, and the like. Tertiary side chain obtained by copolymerization with Vinyl copolymer having both the amino group and a hydroxyl group can also be used.

Separately, typical examples of the tertiary amino group-containing primary or secondary amines include N, N-dimethylethylenediamine and N, N-diethylethylenediamine such as N, N-diethylethylenediamine.
Dialkylethylenediamines, N, N-dimethyl-1,3-
N, N-dialkyl-1,3-propylenediamines such as propylenediamine, N, N-diethyl-1,3-propylenediamine; or N, N-dimethyl-1,6-hexamethylenediamine, N-methylpiperazine , N-alkylpiperazines such as N-ethylpiperazine; or the above tertiary amino group-containing (meth) acrylate monomers, ethylenediamine, propylenediamine, hexamethylenediamine, piperazine, methylamine, ethylamine, butylamine or ammonia. And the like.

From the viewpoint of curability and the like, N, N-dialkylaminoethanol and N, N-dialkylaminopropylamine are particularly preferable compounds (a-2).

Then, the compound (a-1) and the compound (a-
From 2), in order to obtain the vinyl copolymer (A) as the base resin component in the composition of the present invention, one equivalent of the acid anhydride group in the compound (a-1) is used in the compound (a-2). The two compounds may be mixed at a ratio such that the active hydrogen-containing group is about 0.5 to 3 equivalents and reacted at a temperature ranging from room temperature to about 120 ° C.

Also, a tertiary amino group-containing vinyl copolymer (A) prepared by another method
As a method for producing the compound, there is a method disclosed in JP-A-52-76338. That is, (1) 0.2 to 30% by weight of a tertiary amino group-containing acrylic monomer and (2) 35 to 99.8% by weight of an ester of acrylic acid or methacrylic acid and an aliphatic monohydric alcohol or a mixture thereof. When,
(3) A vinyl copolymer (A) comprising 0 to 60 parts by weight of another copolymerizable vinyl monomer. Examples of the tertiary amino group-containing acrylic monomer used herein include derivatives of acrylic acid or methacrylic acid such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate or tert-butylaminoethyl (meth) acrylate. Preferably used, besides N-dimethylaminoethyl (meth) acrylamide,
(Meth) acrylamide derivatives such as N-diethylaminoethyl (meth) acrylamide or N-dimethylaminopropyl (meth) acrylamide can also be used. The use amount of these is suitably in the range of 0.2 to 30% by weight, but is preferably in the range of 0.5 to 15% by weight for reasons of performance and cost.

Further, as each monomer used in (2) and (3), other vinyl monomers having copolymerizability described in the first method of the production method may be used. Other monomers not described include hydroxy (meth) acrylates such as β-hydroxyethyl or β-hydroxypropyl (meth) acrylate; “FM monomers” or “FA monomers” [both are Daicel Chemical ( stock)
Ε-caprolactone-added monomers produced by the company]; methylol compounds of amide bond-containing monomers such as (meth) acrylamide or diacetone acrylamide; or
-Vinyl pyridine and the like can also be used.

The amount of the components (2) and (3) used is 35
Suitably, it is in the range of 99.8% by weight, preferably 50-80% by weight and 0-60% by weight, preferably 20-45% by weight.

To prepare the vinyl copolymer (A) from the above-mentioned various monomers, a known and commonly used polymerization method as described in the first method of the production method, using a known and commonly used solvent and a polymerization initiator. The polymerization may be performed by a conventional method. However, when only the effect of preventing coloring is required, the present invention is not limited to the above range.

Thus, according to each method, a vinyl copolymer (A) having at least one tertiary amino group in one molecule
Is obtained.

Next, as the polyepoxy compound (B), the polyepoxy compounds disclosed in the above-mentioned JP-A-59-56423 and JP-A-59-142220 may be used. That is, various epoxy compounds as described above, excluding the monoepoxy compound, can be used as they are.

The mixing ratio of the vinyl copolymer (A) and the polyepoxy compound (B) is such that, in the case of the first method among the methods for producing the vinyl copolymer (A), the vinyl copolymer (A) included,
The ratio is such that the epoxy group contained in the polyepoxy compound (B) is 0.5 to 2 equivalents to 1 equivalent of the total of the carboxyl group, the tertiary amino group and the unreacted acid anhydride group. In the case of using another method, the vinyl copolymer (A) and the polyepoxy compound (B)
The ratio of the basic nitrogen atom (gram atom) in the vinyl copolymer (A) to the oxygen atom (gram atom) of the epoxy group in the polyepoxy compound (B) is 1: 0.5-3. Thus, the polyepoxy compound (B) may be blended.

Further, as the above-mentioned curing accelerator (C), the following are mentioned as an organic trivalent phosphonium salt, an organic trivalent phosphine, and an organic trivalent phosphite used in the present invention. First, as the organic trivalent phosphonium salt, for example, triethylbenzylphosphonium chloride, tri-n-butylallylphosphonium chloride, tri-n-butylallylphosphonium bromide, tetra-n-butylphosphonium chloride, tetra-n-butylphosphonium chloride Bromide or tetra-n-butylphosphonium iodide is a typical example. As organic trivalent phosphines, for example,
Trimethylphosphine, triethylphosphine, tributylphosphine, triphenylphosphine, tri (p-
Methylphenyl) phosphine, tri (norylphenyl)
Representative examples include phosphine, methyldiphenylphosphine, dibutylphenylphosphine, tricyclohexylphosphine, and 1,2-bis (diphenylphosphine) methane. Representative examples of organic trivalent phosphites include triphenyl phosphite.
Each of the above-mentioned compounds may be used alone or in combination of two or more kinds. The amount of the compound added may be determined in consideration of the low-temperature curability of the obtained resin composition and the effect on the heat-resistant yellowing of the cured coating film. The range of 0.01 to 10% by weight of the solid content of the combined (A) is sufficient.

If the amount is less than 0.01% by weight, the desired low-temperature curability cannot be obtained, while if it exceeds 10% by weight, the pot life becomes extremely short, which is not preferable. Especially, 0.09-5%
Is preferable.

The curable resin composition of the present invention thus obtained may be used as a coating as it is, or, further,
If necessary, pigments, solvents or fibrous compounds such as cellulose acetate butyrate, chlorinated polyolefins, polyisocyanates, blocked polyisocyanates, polyester resins, other synthetic resins such as alkyd resins or ketone resins, further, UV absorbers such as benzotriazole-based, hydroxybenzophenone-based or unsaturated nitrile-based compounds, or an antioxidant or a light stabilizer such as a hindered phenol-based compound or a hindered amine-based compound may also be used. it can.

Paints obtained using the composition of the present invention, in the form of clear paint or enamel paint, for automobile repair, woodworking or building exterior, for building materials or for various plastic products, further for plants, for bridges, It can be used as a coating for inorganic materials, tiles, cement tiles, etc., and can also be used as a sealing agent or adhesive.

〔Example〕

Next, the present invention by reference examples, examples and comparative examples,
As will be described more specifically, all parts and percentages are by weight unless otherwise specified.

Reference Example 1 [Preparation example of tertiary amino group-containing vinyl copolymer (A)] In a reactor equipped with a stirrer, a thermometer, a nitrogen inlet tube and a reflux condenser, 392 parts of toluene and 408 parts of isobutanol were added. And heated to 80 ° C. under a nitrogen atmosphere, and 900 parts of methyl methacrylate, 100 parts of dimethylaminoethyl methacrylate, azobisisobutyronitrile (A
5 parts of tert-butyl peroxyoctoate (IBN)
Mixture 3 consisting of 5 parts of BPO) and 200 parts of toluene
It was dropped over time. After holding at the same temperature for 2 hours, AI
5 parts of BN, 448 parts of toluene and 37 parts of isobutanol
Parts of the mixture were added dropwise over 1 hour. Next, the solution was kept at the same temperature for 12 hours to obtain a solution of a tertiary amino group-containing vinyl copolymer (A) having a nonvolatile content (NV) of 40% and a number average molecular weight (n) of 12,000. Hereinafter, this polymer solution is abbreviated as polymer (A-1).

Reference Examples 2 and 3 (same as above) In the same manner as in Reference Example 1 except that the monomers shown in Table 1 were used instead of 900 parts of methyl methacrylate and 100 parts of dimethylaminoethyl methacrylate. And a solution of tertiary amino group-containing vinyl copolymers (A-2) and (A-3) having an NV of 40%. Hereinafter, these polymer solutions are used as polymers (A-2) and (A-3).
Abbreviated.

Reference Example 4 (same as above) In the same reactor as in Reference Example 1, 300 parts of toluene and 400 parts of butyl acetate were charged, and the temperature was raised to 110 ° C under a nitrogen atmosphere. Then 100 parts of styrene, 400 parts of methyl methacrylate, 300 parts of n-butyl methacrylate, n
130 parts of butyl acrylate, 30 parts of acrylic acid, 40 parts of maleic anhydride, 10 parts of AIBN, 5 parts of TBPO, tert-
A mixture consisting of 5 parts of butylperoxybenzoate (TBPB) and 300 parts of toluene was added dropwise over 3 hours, then kept at the same temperature for 15 hours to continue the reaction, with an NV of 50% and n 10,000 solutions of the vinyl copolymer (a-1) having an acid anhydride group and a carboxyl group were obtained. Hereinafter, this solution is abbreviated as vinyl copolymer (a-1-1).

Next, the temperature of the vinyl copolymer (a-1-1) was lowered to 70 ° C., 40 parts of N, N-dimethylaminoethanol was added thereto, and the temperature was maintained at the same temperature for 5 hours.
-270 parts of butanol was added to obtain a solution of the polymer (A) containing a tertiary amino group and a carboxyl group and having an NV of 45%. Hereinafter, this polymer solution is referred to as polymer (A-4).
Abbreviated.

Reference Example 5 (same as above) 1,000 parts of the vinyl copolymer (a-1-1) having an acid anhydride group and a carboxy group obtained in Reference Example 4 was heated to 90 ° C. under a nitrogen stream, 20.8 parts of N, N-dimethyl-1,3-propylenediamine was added, and the mixture was kept at the same temperature for 6 hours to perform a dehydration reaction. During this time, the acid value at the beginning of the reaction
From 22.7, it dropped to 12.5 at the end of the reaction. From this, it is clear that about 90 mol% of the amide bond once formed was converted to an imide ring.

According to the IR spectrum analysis, the absorption of the amide bond disappeared, and instead, the absorption at 1700 cm ^{−1 due} to the imide ring was confirmed.

135 parts of n-butanol were added to the imide ring-containing polymer solution thus obtained to obtain a polymer (A) solution having an NV of 45% and a Gardner color of 1 or less.
Hereinafter, this polymer solution is abbreviated as polymer (A-5).

Examples 1 to 6 and Comparative Example 1 Each of the polymer solutions (A) obtained in each of the reference examples was used as a base resin component. Was prepared.

Next, each paint was diluted with a mixed solvent of xylene / toluene / n-butanol / cellosolve acetate = 30/40/20/10 (weight ratio) until the spray viscosity was reached,
Paint on slate board and PP board, and then
It was left to cure at room temperature and 0 ° C. for 7 days.

When the performance of each coating film thus obtained was evaluated, the results shown in Table 3 were obtained.

[Effects of the Invention] The coating obtained from the composition of the present invention is sufficiently cured by drying at room temperature for several hours after application, or by drying at 40 to 100 ° C for about 10 to 60 minutes.
It has excellent curability at a low temperature of about 10 ° C. and excellent yellowing resistance during drying, and gives a cured film with good physical properties, stain resistance and alkali resistance.

Claims (3)

(57) [Claims] 1. A resin composition comprising a vinyl copolymer (A) having at least one tertiary amino group in one molecule as a base resin component and a polyepoxy compound (B) as a curing agent component. And at least one compound (C) selected from the group consisting of an organic trivalent phosphonium salt, an organic trivalent phosphine and an organic trivalent phosphite as a curing accelerator component, and the vinyl copolymer (A) A curable resin composition having excellent low-temperature curability, in particular, in the range of 0.01 to 10% by weight. 2. The above-mentioned vinyl copolymer (A) having at least one tertiary amino group in one molecule comprises a carboxylic anhydride-containing vinyl copolymer (a-1) and this carboxylic anhydride. 2. A reaction product with a compound having both a group having an active hydrogen capable of reacting with a group and a tertiary amino group.
3. The curable composition according to item 1. 3. The vinyl copolymer (A) having at least one tertiary amino group in one molecule is a vinyl monomer having a tertiary amino group-containing vinyl monomer as an essential monomer component. The curable resin composition according to claim 1, which is a copolymer of a mixture of monomers.