JPH0273861A - Thermosetting composition excellent in preservation stability - Google Patents

Abstract

PURPOSE:To obtain the subject thermosetting composition, improved in preservation stability and suitable for coating automobiles, industrial machines, etc., by using and blending a hydroxyl group-containing resin with an alkoxysilane group-containing copolymer, hydrolyzable ester compound as a dehydrating agent and alkyl alcohol as a solvent in combination. CONSTITUTION:A composition obtained by blending (A) a hydroxyl group- containing resin (e.g., alkyd resin) having 20-300mg KOH/g hydroxyl value and 500-40000 number-average molecular weight with (B) an alkoxysilane group- containing copolymer containing 5-95wt.% alkoxysilanevinyl monomer units having polymerizable unsaturated double bond and alkoxysilane group in the molecule, (C) a dehydrating agent which is a hydrolyzable ester (e.g., methyl orthoacetate), (D) a solvent containing an alkyl alcohol and, as necessary, (E) a dehydration accelerator.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is applicable to, for example, automobiles, industrial machinery, steel furniture,
This invention relates to a thermosetting composition for use in coating home appliances, plastics, etc.

(Prior art and issues) In conventional thermosetting paints, melamine is used as a crosslinking agent, such as alkyd melamine, acrylic melamine, and epoxy melamine, and melamine fIB! Although the odor problem of II remained unresolved, an improvement was made in this case by using an alkoxysilane group-containing copolymer instead of melamine, and a patent application has already been filed for this. However, these base ingredient mixtures are not fully satisfactory in terms of storage stability, and a solution to this problem has been elusive.

(Means and effects for solving problems) Mr. Inventive,
As a result of intensive study to improve this storage stability,
It has been found that by using a hydrolyzable ester compound as a dehydrating agent in combination with an alkyl alcohol, a composition having the same remarkable storage stability as described above can be obtained.

That is, the present invention uses sesame oil (A) that scavenges hydroxyl groups, an alkoxysilane group-containing copolymer Q3), a dehydrating agent 0, and a solvent (D
The gist of the invention is a thermosetting composition whose main component is a composition consisting of:

The resin (4) having a hydroxyl group is an alkyd arm or oil-free alkyd resin with an oil length of 50% or less, which is conventionally used as a thermosetting paint, an acrylic modified alkyd resin, an acrylic resin, an epoxy resin, and a water-based silicone. oil, etc., and preferably has a number average molecular weight of 500 to 40,000 and a hydroxyl value of 20.
~500 Cape KOH/V. In addition, tree N (4) that grows hydroxyl groups and alkoxysilane group-containing copolymer 03
) The weight ratio of (A)/(B) is preferably 9/1 to 1.
It is 7B. The present invention utilizes a crosslinking reaction in which the hydroxyl groups of the tree B8 (A) react with the silyl groups of the alkoxy group-containing copolymer (B), thereby clearly distinguishing it from the conventional technology using melamine as a crosslinking agent. .

The hydroxyl group-containing resin (4) used in the present invention can be obtained by polymerization step 1 using conventional techniques. Further, the alkoxysilane group-containing copolymer (B) used in the present invention has a main chain consisting essentially of polyvinyl type bonds, and terminal or /J
A silyl group-containing vinyl compound having at least one silica atom in one molecule bonded to a hydrolyzable group in the R chain, (
It can be produced by cold-blending 4) and (B), or by partially reacting them by heating (hot-blending) after mixing.

The alkoxysilane group-containing copolymer (B) is obtained by co-polymerization of a vinyl monomer and a hydrolyzable silyl group-containing monomer, and may partially contain urethane bonds or siloxane bonds in the main chain or side chain. . There are no particular limitations on the vinyl monomers used at this time, including methyl (meth)acrylate, ethyl (meth)acrylate, butyl (
meth)acrylate, 2-ethylhexyl (meth)acrylate, stearyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, trifluoroethyl (meth)acrylate, pentafluoropropyl (meth)acrylate, polycarboxylic acid ( Styrene, a-
Aromatic hydrocarbon vinyl compounds such as methylstyrene, chlorostyrene, styrene sulfonic acid, 4-hydroxystyrene, and vinyltoluene; vinyl esters and allyl compounds such as vinyl acetate, vinyl propionate, and diallyl phthalate; Nitrile group-containing vinyl compounds such as KuchiniF・Ril; epoxy group-containing vinyl compounds such as glycidyl (meth)acrylate; amino acids such as dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, vinylpyridine, aminoethyl vinyl ether, etc. Vinyl compounds; (meth)acrylamide,
Itaconic acid diamide, α-ethyl (meth)acrylamide, crotonamide, maleic acid diamide, fumaric acid diamide, N-vinylpyrrolidone, N-butoxymethyl (meth)acrylamide, N,N-dimethylacrylamide,
N-methylacrylamide, acryloylmorpholine and other amide groups, H=)I'compounds; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxyethyl vinyl ether,
N-methylol (methanecrylamide, Aronix 57
00 (manufactured by Toagosei ■), Placel Fr~-1
, P1acc6] FA-4, Placel FM-1
, Placcel FM-4 (manufactured by Daicel Chemical); salts of (meth)acrylic acid, maleic acid, fumaric acid, itaconic acid and the like (alkali metal salts, ammonium salts, amine salts, etc.), unsaturated carboxylic acids such as maleic anhydride, acid anhydrides, or their salts; vinyl methyl ether, vinyl chloride, vinylidene chloride, chlorobrene, propylene, butadiene, isoprene, maleimide, N-vinylimidazole and other vinyl compounds such as vinyl sulfonic acid.

Further, the alkoxysilane vinyl monomer used at this time is specifically OH.

0H1=OH81(C)OHs)1, OHt=O
H8i (OCR Jia) 薯, OH.

OH rent = OH000 (CHI) i8i (OCHg) t,
Oh! =OHOOOCOHt )g 81(OOHs
)s.

jH1 0Ht=O(OHs) 000 (OHt)s 8
i (C)0Hi )t, OH! =0(CHI)000
(CHI n18i(OOHs)s, 0Ht=O(
OHs)000(OHt)s81(OO!Hs)g, O
H.

0H1=O(OHs)000(OHt)s81(C)0
*Hi)t, etc.

These alkoxysilane vinyl monomer units are contained in the copolymer (B) preferably in an amount of 5 to eoxm%, more preferably 11 to 10% by weight.

Regarding the production method of a copolymer of an alkoxysilane vinyl monomer and a vinyl monomer, for example, JP-A No. 64-583
95, 57-88109, 5g-157810, etc. may be used. Solution polymerization using an azo radical initiator such as azobisisobutyronitrile is most preferred.

In addition, n-dodecylmercaptan, t-dodecylmercaptan, n-butylmercaptan, r-mercaptopropyltrimethoxysilane, r-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropyl Methyljethoxysilane, (HiOO)iSi-8-8-81
(C)014i)i, C0HsO)s81-
Molecular weight can be adjusted using a chain transfer agent such as 89-8i (OOHs)1. In particular, if a chain transfer agent having a hydrolyzable silyl group in the molecule, such as γ-mercaptopropyltrimethoxysilane, is used, the hydrolyzable silyl group can be introduced into the terminal t of the silyl group-containing vinyl copolymer.

Polymerization solvents include hydrocarbons (toluene, xylene, n-hexane, cyclohexane, etc.), acetic esters (ethyl acetate, butyl acetate, etc.), alcohols (methanol, ethanol, isopropanol, n-butanol, etc.), and ethers. (ethyl cellosolve, butyl cellosolve, cellosolve acetate, etc.), ketones (methyl ether ketone,
There is no particular limitation as long as it is a non-reactive solvent such as ethyl acetoacetate, acetylacetone, diacetone alcohol, methyl isobutyl ketone, acetone, etc.).

Specific examples of dehydrating agents include methyl orthoformate, ethyl orthoformate, methyl orthoacetate, ethyl orthoacetate, methyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, methylsilicate, ethylsilicate, etc. There are hydrolyzable ester compounds.

These hydrolyzable ester heptacompounds may be added during the polymerization of the alkoxysilane group-containing copolymer Q3) or may be added to the polymerization system.

It is possible to further enhance the effect by using the dehydration accelerator described below in combination with the dehydration agent.

Inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid; organic acids such as formic acid, acetic acid, oxalic acid, benzoic acid, phthalic acid, I)-) luenesulfonic acid, acrylic acid, methacrylic acid; alkyl titanates, octyl Metal salts of carboxylic acids such as lead acid; carboxylic acid-type organotin compounds such as tin octylate, dibutyltin dilaurate, and dioctyltin malate; sulfide-type and mercaptide-type knitted compounds such as monobutyltin sulfide and dioctyltin mercaptide; ; Organotin monooxide such as dioctyltin oxide; ■ Organotin compound obtained by reaction of tin oxide with an ester compound such as ethyl silicate, ethyl silicate 40, dimethyl maleate, dioctyl phthalate; tetraethylene pentamine, triethylene diamine, Amines such as N-β-aminoethyl-γ-aminopropyltrimethoxysilane; alkali catalysts such as potassium hydroxide and sodium hydroxide are effective; organic acids, inorganic acids, and organic tin compounds are particularly effective.

These catalysts are used in an amount of 0.001 to 2ON parts, preferably o, per 100ffi parts of the hydrolyzable ester compound.
oot to 10-layered tombs are used. .

The bath agent that can be used in the present invention is a solvent that dissolves both the tM resin containing hydroxyl groups and the alkoxysilane group-containing copolymer 03), or the resin BM containing hydroxyl groups! (4
) and alkoxysilane group-containing copolymer 03), any solvent that does not cause precipitation may be used, and 6H aliphatic hydrocarbons and aromatic hydrocarbons used in general paints, coatings, etc. , halogenated hydrocarbon GI, alcohols, ketones, esters, ethers, alcohol esters, ketone alcohols, ether alcohols,
C using ketone ethers, ketone esters, and ester ethers can be obtained. Furthermore, when these solvents contain alkyl alcohol, the stability of the composition of the present invention can be further improved.

Regarding the alkyl alcohol used for this purpose, alcohols in which the alkyl has 1 to 10 carbon atoms are preferred, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, 8eC -butyl alcohol,
tart-butyl alcohol, n-amyl alcohol,
Isoamyl alcohol, hexyl alcohol, octyl alcohol, cellosolve, etc. are used. The amount of solvent is
It varies depending on the molecular weight or III composition of the silyl group-containing vinyl polymer, and is used in accordance with the practically required solid content concentration or viscosity.

The composition of the present invention may contain various N solvents, diluents, pigments (including extender pigments), ultraviolet!! additives such as absorbers, anti-settling agents, leveling agents, etc.: nitrocellulose, cellulose. Resins such as a!/# such as acetate butyrate, base; epoxy resins, melamine resins, vinyl chloride resins, chlorinated polypropylene, salt rubber, and polyvinyl butyral can be added.

The composition of the present invention can be cured at a temperature of 30 DEG C. or higher, preferably 55" to 350 DEG C., after being applied to the object by a conventional method such as dipping, spraying or brushing.

(Example) Next, an example of the present invention will be described. In the examples, "Part J" and "F% J" are based on weight.

am production example 1 45.9 parts of xylene was charged into a reaction vessel equipped with a stirrer, a sieve, a reflux condenser, a N2 gas introduction tube, and a dropping funnel, and the temperature was raised to 110°C while introducing Nl gas. Thereafter, mixture (a) shown below was added dropwise at a constant rate over 5 hours using a dropping funnel.

Mixture (a) Styrene 12.3 parts Methyl methacrylate 50.1 Stearyl methacrylate (,9//γ-methacryloxypropyltrimethoxysilane SO,2/1 Xylene 15.6/12.
4.5 parts of 2'-azobisisobutyronitrile After completing the dropwise addition of mixture (a), 0.5 parts of 2,2'-azobisisobutyronitrile and 6 parts of toluene were added dropwise at a constant rate over 1 hour. After dropping, mature at 110"C for 2 hours, cool, add xylene to the resin gi, and macerate the solid content to 60%.
T, ta. Table 1 shows the properties of the resin solution (A) obtained.

Resin Production Example 2 Butyl acetate 3 was used instead of the polymer compound (a) in Resin Production Example 1.
Add 1.6 parts of xylene, 1 part of xylene, and mix the following mixture (
A resin solution (B) was obtained in the same manner as in Resin Production Example 1 except that b) was used.

Mixture (b) Xylene 18 parts Styrene 2 g, 5 // Methyl methacrylate 7.1 Acrylic Mn
-Butyl 5,6 methacrylic acid
0.3〃Plaxel FM-1 (
Note 1) 31.8 //2.2'-Azobisisobutyronitrile 1.8 (Note 1) Daicel Chemical: 2-hydroxyethyl methacrylate/ε-caprolactone = 1/1 adduct mixture Q: 1 ), 0.2 parts of 2,2'-azobisisobutyronitrile and 3.8 parts of toluene were added dropwise at a constant rate over 1 hour. After dropping, mature at 110°C for 2 hours, cool, and reduce the solid content of the resin fg liquid to 60% with xylene.
Adjusted to. Table 1 shows the properties of the obtained m fat solution.

Table Examples 1-5, Comparative Examples 1-2 tI! Fat production example 1 and! FI obtained with! Fat solution solution 2
The composition was prepared as shown in . A storage test was performed on this at 60°C for 4 days and 18 days under sealed conditions, and the viscosity before and after storage was measured at 25°C using a B-type viscometer, and the rate of change in viscosity after storage compared to before storage was determined. , the results are shown in Table 3.

Margin table below! As is clear from the evaluation results in Table 3, it can be seen that Examples 1.2.6 have significantly improved storage stability.

Patent applicant Kanebuchi Chemical Industry Co., Ltd.

Claims (8)

[Claims] (1) A thermosetting composition whose main components are a resin having a hydroxyl group (A), an alkoxysilane group-containing copolymer (B), a dehydrating agent (C), and a solvent (D). (2) The resin (A) having a hydroxyl group has a hydroxyl value of 20 to 3
00mgKOH/g, number average molecular weight is 500-40,
000. The thermosetting composition according to claim 1, wherein the thermosetting composition is 000. (3) The alkoxysilane group-containing copolymer (B) contains 5 to 90% by weight of alkoxysilane vinyl monomer units having a polymerizable unsaturated double bond and an alkoxysilane group in the molecule.
The thermosetting composition according to claim 1, which comprises: (4) The thermosetting composition according to claim 1, wherein the dehydrating agent (C) is a hydrolyzable ester compound. (5) The thermosetting composition according to claim 1, wherein the solvent (D) contains an alkyl alcohol. (6) The thermosetting composition according to claim 1, wherein the dehydrating agent (C) is methyl orthoacetate. (7) Methyl orthoacetate as a dehydrating agent (C) and a solvent (
The thermosetting composition according to claim 1, comprising an alkyl alcohol as D). (8) Methyl orthoacetate as a dehydrating agent (C) and a solvent (
The thermosetting composition according to claim 1, which contains an alkyl alcohol and a dehydration accelerator as D).