JPS6187719A - Curable resin composition - Google Patents

Abstract

PURPOSE:The titled composition which has excellent low-temperature curability and can give a paint film of excellent properties, prepared by mixing a copolymer comprising an aminoalkyl (meth)acrylate and an ethylenically unsaturated monomer with a blocked polyisocyanate compound. CONSTITUTION:A curable resin composition prepared by mixing a copolymer (A) composed of an aminoalkyl (meth)acrylate [e.g., aminoethyl (meth)acrylate] and an ethylenically unsaturated monomer [e.g., ethyl (meth)acrylate, vinyl acetate or styrene] with a blocked polyisocyanate compound (B) [e.g., a compound comprising 1,3-bis(isocyanatomethyl)cyclohexane, trimethylolpropane and methyl ethyl ketoxime]. When heated, this composition undergoes crosslinking by reaction between the isocyanato groups and the amino groups forms a film excellent in flexibility, chemical resistance, water resistance, impact resistance, corrosion inhibition, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polyurethane-based curable resin composition that forms a wall film with excellent low-temperature curability. The resulting coating film is flexible, chemical resistant, water resistant, and impact resistant.

Due to its excellent corrosion resistance, it is extremely useful as a baking paint or adhesive for metals, heat-resistant plastics, inorganic materials, etc.

Conventional technology In general, resin compositions for coatings consisting of blocked polyisonanates and compounds containing hydroxyl groups such as polyester polyols, polyether polyols, acrylic polyols, and evoquino resins have excellent corrosion resistance and chemical resistance. , #l
Because of its high mechanical properties, it is widely used as a baking coating for automobile exteriors, cationic electrodeposition, home appliance coatings, pre-coated metals, enamel electric wires, etc.

However, in general, baking-type paints made of blocked polyisonanate and hydroxyl group-containing compounds require 14
Heating at 0-180°C for 20-40 minutes is required. Therefore, energy costs are high, and the objects to be coated are usually limited to metal products, and among these, there are few cases in which they are used for objects to be coated that have a large specific heat.

In the field of baking coating for plastic products, only a small amount of coating is applied to molded products of thermosetting resins such as phenol, urea, melamine, unsaturated polyester, and epoxy. A
Currently, molded products of BS, polypropylene, polyethylene, polycarbonate, etc. are used off-line as either a lacquer type or a room temperature drying type such as two-component urethane.

Problems to be Solved by the Invention The object of the present invention is to provide a curable resin composition that has excellent low-temperature curability and also has excellent coating film properties.

Means for Solving the Problems In view of the above-mentioned circumstances, the present inventors conducted intensive research and found that (1) a compound composed of aminoalkyl acrylate or aminoalkyl methacrylate and an ethylenically unsaturated monomer; It was discovered that by combining the copolymer (2) with the blocked polyisocyanate compound, a coating film that cures at extremely low temperatures and exhibits excellent physical properties can be obtained.Based on these findings, the present invention was completed. I ended up doing it.

That is, the present invention provides a curable resin composition comprising (1) a copolymer composed of aminoalkyl acrylate or aminoalkyl methacrylate and an ethylenically unsaturated monomer, and (2) a blocked polyisocyanate compound. It is.

The copolymer of Section 1111 (1) used in the present invention is:
General formula % Formula % (In the formula, R1 is hydrogen or a methyl group, R'' has 1 carbon number
~6 alkylene group or hydroquine alkylene group is R
3 represents hydrogen or an alkyl group having 1 to 6 carbon atoms) and an ethylenically unsaturated monomer.

Examples of aminoalkyl acrylate or aminoalkyl methacrylate include aminomethyl acrylate and aminoethyl acrylate.

Acrylates such as aminopropyl acrylate, amino-n-butyl acrylate, aminohexyl acrylate, N-methylaminoethyl acrylate, N-1ert-butylaminoethyl acrylate, and aminohydroxypropyl acrylate.

Aminomethyl methacrylate, aminoethyl methacrylate, amino-n-butyl methacrylate.

N-methylaminoethyl methacrylate), N-tert
Examples include methacrylates such as -butylaminoethyl methacrylate and aminohydroxypropyl methacrylate. The content of these aminoalkyl acrylates or aminoalkyl methacrylates in the copolymer is usually about 1 to 40% by weight, preferably about 2 to 80% by weight.

On the other hand, ethylenically unsaturated monomers include, for example, acrylates such as methyl acrylate, ethyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate; methacrylates such as methyl methacrylate, ethyl methacrylate, and n-butyl methacrylate;
Fatty acid vinyl esters such as vinyl acetate and vinyl propionate, aliphatic monoolefins such as ethylene, propylene and isobutyne, aromatic monoolefins such as styrene and vinyltoluene, and other acrylonitrile.

Examples include vinyl chloride and vinyl fluoride.

The copolymer may contain one or more of the above monomers, and the copolymer usually contains about 60 to 99% by weight, preferably about 20 to 80% by weight.

A copolymer consisting of aminoalkyl acrylate or aminoalkyl methacrylate and an ethylenically unsaturated monomer is advantageously produced, for example, by solution polymerization, and the solvent used in the reaction is the same as the solvent of the resin composition when carrying out the present invention. It is preferable to use Generally, the total monomer concentration is about 20-80% by weight, and the polymerization initiator is an oil-soluble free radical-forming catalyst such as α,α'-azobisisobutyronitrile, benzoyl peroxide,
Lauroyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, etc. are used, and if necessary, it is possible to use a redox catalyst in combination with an appropriate reducing substance. Furthermore, a small amount of butylmercaptan, dodecylmercaptan, [-dodenylmercaptan, β-mercaptoethanol, etc.] may be added as a molecular Nil adjustment agent for the copolymer. Polymerization is carried out in an inert gas at normal pressure and around 30 to 100°C.

The copolymer thus obtained contains at least two amino groups and has a molecular weight of about 1.000 to too
, ooo, preferably about 5,000 to 500,000. The copolymer may be used as it is, or may be ketiminated with an aliphatic ketone or cyclic ketone such as methyl ethyl ketone, methyl isobutyl ketone, or cyclohexanone.

The polyisocyanate used in the blocked polyisocyanate compound (2) used in the present invention is as follows:
For example, trimethylene diisonoanate. Tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisonoanate,! , 2-propylene diisocyanate.

2.3-Butylene diisocyanate, (1), 3-butylene diisocyanate, 2.4.4- or 2,2°4-trimethylhexamethylenenoisonoano-t.

Aliphatic diisocyanates such as dodecamylene diisonanate, 2,6-diisocyanatomethyl caproate, e.g. 1,3-cyclopentane diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-
Cyclohexanediisonoisocyanate, 3-isocyanatomethyl-3.5.5-trimethylchlorohequinolisonanate, 4.4'-methylenebis(cyclohexyl isocyanate).

Methyl-2,4-cyclohexane diisonoanate, methyl-2,6-cyclohexane diisocyanate, l,
4-bis(isocyanatomethyl)chlorohexane, l
, cycloalkylene diisocyanates such as 3-bis(isocyanatomethyl)cyclohexane, e.g.
- phenylene diisonanate, p-phenylene diison anate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 4,4'-diphenylmethane isocyanate, 2,4- or 2,
6-Drylene diisonanate, 4.4'-toluidine diisonanate, dianisinone diisonanate, 4
．． Aromatic diisocyanates such as 4'-diphenyl ether diisocyanate, such as ω, ω'-diisonanate to 1,3-dimethylbenzene, ω, ω'-diisocyanate to 1,4-dimethylbenzene.

Aroaliphatic diisocyanates such as ω, ω′-diisocyanate)-1,4-diethylbenzene, 1,3-tetramethylxylylene diisocyanate, and 1,4-tetramethylxylylene diisocyanate.

For example, triphenylmethane-4,4', 4'-triisocyanate, l,3,5-triisocyanatebenzene, 1,3,5-triisocyanatecyclohexane, 2,4,6-dryisonanatetoluene, ω- triisocyanates such as isocyanate ethyl-2,6-diisocyanatocaproate, tetraisocyanates such as 4,4'-diphenyldimethylmethane-2,2', 5,5'-tetraisocyanate, e.g. diisocyanate monomers; Polymerized polyisocyanate such as 21-mer or trimer consisting of polymethylene polyphenyl polyisonanate or an excess of the above-mentioned isonoanate compounds, such as ethylene glycol, propylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, etc.゜2.4-Trimethyl-1,3-bentanediol.

Neopentyl glycol, hexanediol, cyclohexane dimetatool, cyclohexanediol, hydrogenated bisphenol A, xylylene glycol.

Glycerin, trimethylolethane, trimethylolpropane, hexanetriol, pentaerythritol,
Sorbitol, sorbitol, sucrose, castor oil, ethylenediamine, hexamethylenediamine 1 ethanolamine, jetanolamine.

Polyisocyanates obtained by reacting low-molecular active hydrogen-containing compounds such as triethanolamine, water, ammonia, and urea, or high-molecular active hydrogen-containing compounds such as various polyether polyols, polyester polyols, acrylic polyols, and evoquinboliol. Alternatively, they are allophanates, biuret compounds, etc.

The above isonoanate compounds can be used alone or as a mixture of two or more.

Blocking agents used for blocking polyisonanates include those known to be used for blocking isocyanates, such as phenol-based, lactam-based, active methylene-based, and alcohol-based blocking agents. , mercaptan type, acid amide type, imide type,
Any blocking agent such as amine, imidazole, urea, carbamate, imine, oxime, or sulfite may be used, but especially phenol.

Oxime-based, lactam-based, imine-based blocking agents are advantageously used.

Phenolic blocking agent used in the present invention (1)
When combined with a copolymer, it cures at an extremely low temperature of approximately 50 to 100°C. Oxime-based blocking agents and lactam-based blocking agents cure at about 90 to 120°C and exhibit excellent storage stability and coating film properties. The alcohol type cures at about 120 to 140°C and has excellent storage stability and coating film properties. Specific examples of blocking agents include the following.

Phenolic blocking agents: phenol, cresol, quinlenol, nitrophenol, chlorophenol, ethylphenol.

p-hydroxydiphenyl, t-butylphenol.

0-isopropylphenol, o-5ee-butylphenol, p-nonylphenol, pt-octylphenol, hydroxybenzoic acid, hydroquine benzoate, and the like.

Lactam-based blocking agents; ε-caprolactam, δ-valerolactam, γ-butyrolactam, β-propiolactam, etc.

Active methylene blocking agents: diethyl malonate, dimethyl malonate, ethyl acetoacetate, methyl acetoacetate, acetylacetone, etc.

Alcohol blocking agent: methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, t-butyl alcohol.

n Amyl alcohol, L-amyl alcohol, lauryl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, benzyl alcohol, methoxymethanol, glycolic acid , glycolic acid esters such as methyl glycolate, ethyl glycolate, and butyl glycolate; lactic acid esters such as lactic acid, methyl lactate, ethyl lactate, and butyl lactate.

Methylol urea, methylol melamine, diacetone alcohol, ethylene chlorohydrin, ethylene bromohydrin, 1,3-dichloro-2-propatol, ω-hydroperfluoroalcohol, acetocyanhydrin, etc.

Mercaptan-based blocking agents Nibutyl mercaptan, Hequin mercabutan, t-butyl mercaptan, t-dodenyl mercaptan.

2-mercaptobenzothiazole, thiophenol, methylthiophenol, ethylthiophenol, etc.

Acid amide blocking agent: acetanilide, acedoanidicite, acetotoluide,
Acrylamide, methacrylamide, acetamide, stearamide, benzamide, etc.

Imide blocking agents: succinimide, phthalic imide, maleic imide, etc.

Amine blocking agents Nidiphenylamine, phenylnaphthylamine, xylidine, N-phenylquinolinone, carbazole.

Aniline, naphthylamine, butylamine, butylamine, butylphenylamine, etc.

Imidazole blocking agent; imidazole, 2-ethylimidazole, etc.

Urea-based blocking agent: urea, thiourea, ethylene urea, ethylene thiourea, 1
．． 3-diphenylurea etc.

Carbamate-based blocking agents such as phenyl N-phenylcarbamate and 2-oxacylidone.

Imine blocking agent: Ethyleneimine, propyleneimine, etc.

Oquine-based blocking agents: formamidoxime, acetaldoxime, acetoxime, methylethylgatoquinome, acetylmonoxime, benzophenone oxime, cyclohexane oxime, etc.

Sulfite-based blocking agent: Sodium bisulfite, potassium bisulfite, etc.

Blocked polyisocyanate is produced by reacting the above-mentioned polyisocyanate with a blocking agent by a known method. This reaction can be carried out in a solvent that does not contain active hydrogen or without a solvent. Examples of solvents without active hydrogen include esters such as ethyl acetate, butyl acetate, cellosolve acetate, carpitol acetate, trimethyl ester of dibasic acid,
Methyl ethyl ketone, methyl isobutyl ketone, ivy (
Ketones such as J-hexanone, toluene, and quinoa.

Examples include aromatic solvents such as Tsurupetz #1OO and Tsurupetz #150.

As a specific reaction method, an isocyanate monomer or its adduct and a blocking agent are mixed at a ratio of NCO/blocking agent (equivalent ratio) of about 0.9 to 1.1. Preferably about 0.95
~1.0, the isocyanate monomer and blocking agent are NGO/blocking agent (equivalent ratio) is approximately 1.1 ~
3.0. Preferably after reacting at about 1.2 to 2.0,
A means for reacting the above-mentioned low-molecular active hydrogen-containing compound and/or high-molecular active hydrogen-containing compound, and a means for reacting the isocyanate monomer with the low-molecular and/or high-molecular active hydrogen-containing compound so that the NCO/active hydrogen is approximately 1.5. ~10.0. Preferably, after reacting at a temperature of about 2.0 to 7.0, it is possible to react with a blocking agent. For the reaction, known catalysts such as tertiary amines and organic metals may be used.

In the present invention 4, a curable resin composition prepared by blending the copolymer (1) and the blocked polyisonoanate compound (2) is applied to various objects to be coated and heated. A tough coating film can be obtained. The equivalent ratio of the active hydrogen groups in the copolymer (1) to the regenerated isocyanate groups in the blocked polyisocyanate compound (2) is about 0.3 to 3.0.
．． Preferably, it is blended so that it is about 0°5 to 2.0, and additives such as pigments, leveling agents, antifoaming agents, dissociation catalysts, and ultraviolet absorbers, or ketone resins,
Xolene resins, phenoxy resins, celluloses, vinyl resins, etc. may be mixed.

An example of a painting method is air spray.

Airless spray, roll coater, flow coater,
Examples include dipping coat and electrostatic coating. For heating, use hot air, direct flame, infrared rays or far infrared heaters,
High frequencies are used.

"Effects of the Invention" The curable resin composition of the present invention cures at a temperature several times lower than that of commonly used baking paints made of hydroxyl group-containing resins and blocked polyisocyanate compounds. Useful as adhesive, etc. When heated, crosslinking occurs due to the reaction between isocyanate groups and amino groups, resulting in coatings with excellent flexibility, chemical resistance, water resistance, impact resistance, corrosion resistance, etc. It can be used for coating objects such as home appliances, automobiles, and building materials.

Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Reference η Example Preparation of Copolymer Copolymer (A) A copolymer consisting of 70 parts of methyl methacrylate, 15 parts of n-butyl acrylate, and 15 parts of aminoethyl methacrylate, with an average molecular weight of 1,800,000.

Toluene/acetic acid butylene (50150) solution with 50% non-volatile content.

Copolymer (B) 30 parts of methyl methacrylate, 30 parts of Steref.

A copolymer consisting of 20 parts of ethyl acrylate and 20 parts of amino-n-butyl methacrylate with an average molecular weight of I2
10,000, 50% nonvolatile xylene/vinegar vinegar (50150)
Solution blocked polyisocyanate compound (C) 1,3-bis(isocyanatomethyl)cyclohexane 582.6
Ethyl acetate/ethoxyethyl acetate (50150) solution blocked polyisocyanate compound (D) 3 with a composition of 134.1 parts of trimethylolpropane and 261.3 parts of methyl ethyl ketoxime, with a non-volatile content of 60%. -Methyl isocyanate-3,5,5-trimethylchlorohexyl isocyanate 666.9L Trimethylol 134.
1 part, 30 parts of acrylic polyol methylnuccrylate, 20 parts of styrene.

Example 1 Triene solution with non-volatile content of 50% in an acrylic polyol consisting of 30 parts of n-butyl acrylate and 20 parts of hydroquine ethyl acrylate: 862 parts of copolymer (A), 545 parts of blocked polyisocyanate compound (C), Tybake CR-90 (titanium oxide manufactured by 6 Hara Sangyo Co., Ltd.) 505 parts, xylene 194
The mixture was kneaded in a pebble mill for 24 hours to obtain white enamel. This white enamel was applied to a 0.81-thick mild steel plate treated with iron phosphate to a thickness of 40 to 50 μm, and baked at 110° C. for 30 minutes and at 140° C. for 30 minutes. The coating performance is shown in Table 1.-0 Example 2 862 parts of copolymer (A), 634 parts of blocked polyisocyanate compound (D), Tybake CR-90540
and 218 parts of xylene were kneaded in the same manner as in Example 1, followed by baking in the same manner as in Example 1, and a coating film test was conducted.

The test results are shown in Table 1.

Example 3 785 parts of copolymer (B), 545 parts of blocked polyisocyanate compound (C), Tybake CR-90480
A coating film test was conducted by kneading 189 parts of xylene and 189 parts of xylene in the same manner as in Example 1, and baking after coating in the same manner. The test results are shown in Table 1.

Example 4 785 parts of copolymer (B), 515 parts of blocked polyisocyanate compound (D) 6341 Tybake CH-90, and 213 parts of xylene were kneaded in the same manner as in Example 1,
A coating film test was conducted in the same manner by baking after application. The test results are shown in Table 1.

Comparative Example 1160 parts of acrylic polyol, 545 parts of blocked polyisocyanate compound (C), Tybake CR-90
605 parts of xylene and 209 parts of xylene were kneaded in the same manner as in Example 1, and baked in the same manner after application to conduct a coating film test. The test results are shown in Table 1.

(Left below) (fU: hardness) Damaged hardness by Mitsubishi Pencil UNI Vinegar Rubbing Test Gauze impregnated with ethyl acetate and U-painted surface rubbed vigorously.

Bending test Erichsen test using mandrel bending tester Extrusion height acid resistance test using Erichsen testing machine.

Alkali resistance test) Dip at room temperature and observe changes in the painted surface.

Claims (2)

[Claims] (1) A copolymer composed of aminoalkyl acrylate or aminoalkyl methacrylate and an ethylenically unsaturated monomer, and (2) A curable resin composition containing a blocked polyisocyanate compound.