JPS62201973A - Curable resin composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. which has excellent storage curability and (low-temperature) curability and give a coating film having excellent weathering stability, by blending a copolymer having COOH groups with a compd. having at least two aziridinyl groups and a compd. having acryloyl group. CONSTITUTION:A copolymer (A) having COOH groups and a weight-average MW of 1,000-1,000,000, obtd. by copolymerizing 2-20wt% ethylenically unsaturated carboxylic acid [e.g., (meth)acrylic acid] with an ethylenically unsaturated monomer [e.g., methyl (meth)acrylate] is blended with a compd. (B) having at least two aziridinyl groups per molecule (e.g., tetramethylenebisethyleneurea) in a molar ratio of the COOH group in the component A to the aziridinyl group in the component B of 3/1-1/2 and a compd. (C) having acryloyl group (e.g., methyl acrylate) in a molar ratio of the acryloyl group in the component C to the aziridinyl group in the component B of 1/5-1.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a curable resin composition that provides a coating film with excellent weather stability.

Prior Art It has been proposed to use a combination of a carboquinyl group-containing acrylic J (polymer and a compound having at least two aziridinyl groups in one molecule as a pressure-sensitive adhesive or paint. (Japanese Patent Laid-Open No. 50-87433) Publication No., Japanese Patent Application Publication No. 1973
-89430 and JP-A-55-147563).

These compositions have excellent low-temperature curing properties, and the cured products have excellent water resistance, solvent resistance, and adhesion to substrates, but they have poor weather stability, such as yellowing when stored for long periods of time. not good.

Ode A to be Solved by the Invention The present invention improves the weather resistance stability of a coating film of a composition comprising a combination of a carboxyl Jr%-containing acrylic polymer and a compound having at least two aziridinyl groups in one molecule. The purpose is to

In order to solve the problem, the present inventors conducted various studies, and found that a third compound containing a carboquinyl group-containing acrylic co-adhesive compound and an azuro compound having at least two aziridinyl groups in one molecule was developed. It has been found that a composition that provides a coating film with excellent weather resistance stability can be obtained by blending an acryloyl group-containing compound as a component, and based on this knowledge, the present invention has been completed.

That is, the present invention provides (1) a carboxyl group-containing copolymer.

A curable resin composition containing (2) a compound having at least 62 aziridinyl groups in one molecule and (3) an acryloyl group-containing compound.

The jt=ff1 combination (1) used in the present invention is a copolymer composed of an ethylenically unsaturated carboxylic acid and an ethylenically unsaturated monomer.

Specific examples of ethylenically unsaturated carboxylic acids include acrylic acid, methacrylic acid, and itaconic acid.

Examples include maleic acid and fumaric acid. The content of ethylenically unsaturated carboxylic acid in the copolymer is usually about 2 to 20% by weight, preferably about 5 to 15iJfff.
It is about 1%.

On the other hand, examples of ethylenically unsaturated microorganisms include acrylate-1-s such as methyl acrylate, edyl acrylate, n-butyl acrylate, and 2-ethylhequinyl acrylate, methyl methacrylate, ethyl methacrylate-1-, Methacrylates such as n-butyl methacrylate, fatty acid vinyl esters such as vinyl acetate and vinyl propionate, and ethylene. Examples include fatty acid monoolefins such as propylene and isobutyne, aromatic monoolefins such as styrene and vinyltoluene, and acrylonitrile, vinyl chloride, and vinyl fluoride. Among the above monomers, copolymers mainly composed of acrylates and methacrylates are preferred from the viewpoint of weather resistance stability. The copolymer may contain one or more Qih1 bodies.

For the carboxyl group-containing cutting die combination, ethylenically unsaturated carboxylic acid and ethylenically unsaturated monomer are mixed in an aromatic hydrocarbon solvent such as toluene, an alcohol solvent such as isopropyl alcohol, or an ester solvent such as ethyl acetate. Using a radical polymerization initiator such as azobis-based or peroxide-based in the presence of these mixed solvents,
It is produced by copolymerization by a conventional method, using a chain transfer agent such as a mercaptan, if necessary. The carboxyl group-containing copolymer thus obtained contains at least 62 carboxyl groups in one molecule, and has a weight average molecular weight of about t, ooo to t, ooo, ooo.
Preferably, about 5,000 to 100,000 is appropriate.

The carboxyl group-containing copolymer can also be used in the form of an emulsion. This copolymer latex contains the above-mentioned two components, a suitable emulsifier, a suspending agent, and an electrolyte for pH adjustment.

It is produced by copolymerization using a conventional method in the presence of a water-soluble radical initiator (e.g., potassium persulfate, peroxides such as hydrogen peroxide, diazo compounds such as azobisisobutyroaminone hydrochloride, etc.). Ru.

The copolymerization temperature varies depending on the type of monomer and initiator and the desired molecular weight of the polymer, but is usually preferably 60 to 90°C. The molecular weight of the copolymer obtained by this method is usually 100,000. or more and often 1,000,0
It may exceed 00.

Examples of compounds having at least two aziryl or lower alkyl groups having 1 to 4 carbon atoms in one molecule of (2) used in the present invention include tetramethylenebisethyleneurea, hexamethylenebisethyleneurea, and hexamethylenebisethyleneurea. Ethylene urea, tris-1-aziridinylphosphine oxide, trimethylolpropane tri-β-aziridinylpropionate,
Examples include trimethylolpropane tri-β-<2-methylaziridinyl propionate, pentaerythritol tri-β-aziridinyl propionate, and the like.

Among the above, trimethylolpropane tri-[beta]-aziridinylpropionate is particularly preferred.

Examples of the acryloyl group-containing compound (3) used in the present invention include monoacrylates such as methyl acrylate, ethyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate.

Ethylene glycol diacrylate (1-,1,4-butanediol diacrylate, neobentyl glycol diacrylate),! , 6-hexanethiolnoacrylate 1
diacrylates such as trimethylolpropane triacrylate, triacrylates such as pentaerythritol tri-T acrylate, tetraacrylates such as pentaerythritol tetraacrylate, aliphatic or alicyclic diisocyanates, or an excess of these diisocyanates, e.g. Trimethylolprono (
urethane acrylate, methylene bisacrylamide, which consists of a polyisocyanate obtained by reacting with a low molecular weight active hydrogen compound such as carbon, triethanolamine, and water and a hydroxyargyl acrylate such as hydrogine ethyl acrylate and hydrogine ethyl acrylate; Acrylamides such as bisacrylamide methyl ether.

For example, Evoquin groups such as acrylic acid adducts of ethylene glycol diglycidyl ether, acrylic acid adducts of glycerin diglycidyl ether, acrylic acid adducts of bisphenol A diglycidyl ether, acrylic acid adducts of 0=cresol novola glycidyl ether, etc. acrylic acid is reacted with a compound containing ()-.

For example, diacrylate of polyester diol of succinic acid and propylene glycol, nool acrylate of polyester diol of phthalic acid and diethylene glycol, diacrylate of polyester diol of tetrahydrofucuric acid and diethylene glycol, diacrylate of polyester diol of adipic acid and trimethylpropane, propylene glycol, etc. Examples include polyester acrylates such as polyacrylates of polyester polyols.

Among the above, monoacrylates 1)-1- are preferred because the coating film has good weather resistance stability.

([) Carboxyl group-containing" (polymer and (2) aziridinyl group-containing compound The molar ratio of the carboxyl group in the copolymer to the aziridinyl group in the aziridinyl group-containing compound is approximately 3/1 to 1/2. If the mixing ratio exceeds 3/1, the curability of the composition will be poor, and if the mixing ratio is less than !/2, the acid resistance of the cured coating may be poor.

In the aziridinyl group-containing compound and the acryloyl group-containing compound, the molar ratio of the acryloyl group in the acryloyl group-containing compound to the aziridinyl group in the aziridinyl group-containing compound is preferably about 115 to 1/l. If the mixing ratio is less than 115, the effect of improving the weather resistance stability of the cured product will be less than that of 1, and if it exceeds 1, the chemical and physical properties of the cured coating may become poor.

The curable composition of the present invention is a two-component type, that is, the above three components may be mixed at the time of use, but the acryloyl group-containing compound is added in advance to the carboxyl group-containing copolymer and/or the aziridinyl group-containing compound. It can also be used as a mold.

The curable resin composition of the present invention can be prepared by: - For example, a solution of an ester solvent such as ethyl acetate, an alcohol solvent such as isopropyl alcohol, an aromatic 8 group hydrocarbon solvent such as toluene, etc. or as an emulsion dispersed in water. Further, other resins, plasticizers, fillers, stabilizers, pigments, etc. can be added as necessary.

Effects of the Invention The curable resin composition of the present invention not only has good storage stability, but also
Since it has good curing properties at low temperatures ranging from room temperature to about 120°C, it can be used to form coating films on plastics, wood, concrete, and other fields that cannot be heat treated. Of course, it can also be used to form coatings in fields where high-temperature treatment is possible, such as on metal materials. Furthermore, the composition of the present invention provides a coating film that is excellent in terms of water resistance, solvent resistance, and weather resistance stability, so it can be used for L-coating paints and the like. Furthermore, since the composition of the present invention has excellent adhesion to various substrates, it can be used as a necking agent and various types of brimers.

The present invention will be explained in more detail below by reference examples, examples, and comparative examples. Parts and percentages shown in Reference Examples, Examples, and Comparative Examples are by weight.

Reference example! A reactor equipped with a thermometer, a stirrer, 2 dropping funnels, a reflux condenser, and a nitrogen inlet tube was charged with toluene/isopropanol (7
0/30) Charge 150 parts of a mixed solvent, heat to about 80°C under nitrogen introduction, and prepare 60 parts of methyl methacrylate and 30 parts of n-butyl methacrylate.

10 parts of methacrylic acid and 0.5 part of 2.2'-azobisisobutyronitrile were added dropwise over 6 hours.

Two hours after the completion of dropping, add toluene/isopropanol (70
/30) Add 0.15 parts of 2,2'-azobisisobutyronitrile dissolved in 10 parts of the mixed solvent, continue polymerization,
Polymerization continued for a total of 10 hours. The obtained polymer had a nonvolatile content of 38.5% and a weight average molecular weight of about 40,000.

Reference examples 2 to 5 The copolymers shown in the table below were obtained in the same manner as in Reference Example 1.

Below is the margin 1 Table Reference Example 6 112 parts of water and 0.25 parts of sodium lauryl sulfate were charged into a reactor equipped with a thermometer, a stirrer, a sample supply device, a reflux condenser, and a nitrogen introduction tube, and about 7
Heat to 0°C, maintain at 78-80°C, add 0.2 parts of potassium persulfate dissolved in 5 parts of water, 60 parts of methyl methacrylate, 33 parts of n-butyl acrylate,
A mixture of 7 parts of acrylic acid and 1.34 parts of sodium lauryl sulfate were dissolved in 19.6 parts of water and added simultaneously over a period of 2 hours. Next, 0.11 part of potassium persulfate was dissolved in 1 liter of water, 24 parts, and the solution was added, and the mixture was heated for another 2 hours at 70-8
It was kept at 0°C. After cooling, the coarse coagulated material was filtered off to obtain a copolymer latex. The latex obtained had a copolymer content of 41% and an average molecular m of more than 1 million.

Example 1 Reference Example Copolymer solution I&too part and titanium dioxide 33
and 7 parts of trimethylolpropane tri-β-aziridinylpropione+-a and 4.5 parts of trimedylolpropane triacrylate were added (
Carboxyl group/aziridinyl group/acryloyl group -=
1/l/1), cured coating film is 40-50μm
The coating film, which was applied to a mild steel plate and cured for one week at room temperature, has excellent adhesion and chemical resistance (immersion in boiling water for 3 hours,
No change in 5% caustic soda aqueous solution spot test for 1 week and 5% sulfuric acid spot test for 1 week), solvent resistance (ethyl acetate rubbing 50 times, unleaded gasoline immersion 120 times)
There was no change over time). Accelerated weathering tester (
Yellowing degree after 1500 hours of irradiation (△b)
is 0.8. The gloss retention rate was 96%.

Examples 2 to 5 Using the copolymer solutions of Reference Examples 2 to 5, white A paint was prepared and applied to a mild steel plate.

The coating film, which was cured for [weeks] at room temperature, showed excellent adhesion, chemical resistance, and solvent resistance. The results of the accelerated weathering test (1° 500 hours) are as follows.

Example 6 and Comparative Example 1 Trimedyllolbrobantri-β was added to the copolymer of Reference Example 4.
-Aziridinylpropionate and n-butyl acrylate were blended to prepare a clear resin, which was applied as a top coat onto the painted plate obtained in Example I. The physical properties of the clear coating film are as follows. As a comparative example, a clear resin was prepared without adding an acryloyl group-containing compound, and the physical properties of a clear coating film obtained by coating in the same manner as above are shown.

Example 7 33 parts of titane dioxide were dispersed in 100 parts of the copolymer emulsion of Reference Example 6 using a sand mill, and 5.4 parts of trimethylolpropane tri-β-aziridinylpropionate were added.
3.6 parts of trimedylolbrobentriacrylate was added and applied to a mild steel plate so that the cured coating film was 40 to 50 μm thick. The coating film cured for one week at room temperature has excellent adhesion,
It showed chemical resistance, solvent resistance, and weather resistance.

Claims (1)

[Claims] 1. A curable resin composition containing (1) a carboxyl group-containing copolymer, (2) a compound having at least two aziridinyl groups in one molecule, and (3) an acryloyl group-containing compound. thing. 2. Curing according to claim 1, in which the acryloyl group-containing compound (3) is blended with the carboxyl group-containing copolymer (1) and/or the compound (2) having at least two aziridinyl groups in one molecule. resin composition.