JPS6245611A - Curable resin composition - Google Patents

Abstract

PURPOSE:The titled composition which is excellent in low-temperature curability and gives a film good in flexibility, chemical resistance, water resistance, impact resistance and corrosion resistance, comprising a specified copolymer and a blocked polyisocyanate. CONSTITUTION:A copolymer (A) having at least two amino groups and a MW of 1,000-1,000,000 is obtained by solution-polymerizing 1-40wt% aminoalkyl (meth)acrylate of the formula [wherein R<1> is H or methyl, R<2> is a 1-6C (hydroxy)alkylene and R<3> is H or a 1.6C alkyl] with 99-60wt% ethylenically unsaturated monomer (e.g., methyl acrylate) at 30-100 deg.C and normal pressure in an inert gas in the presence of a polymerization initiator (e.g., benzoyl peroxide). A blocked polyisocyanate compound (B) is obtained by reacting a polyisocyanate with a blocking agent (e.g., phenol) at an NCO/blocking agent equivalent ratio of 0.9-1.1. Component A is mixed with component B at such a mixing ratio that the equivalent ratio of the active hydrogen groups of component A to the regenerated isocyanate groups of component B is 0.3-3.0.

Description

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

Because it has excellent water resistance, impact resistance, and corrosion resistance, it is extremely useful as a baking paint or adhesive for metals, heat-resistant materials, inorganic materials, etc.

Conventional technology Generally, blocked polyisocyanates and polyester polyols, polyates, polyols, and acrylic μ polyols are used.
Paint resin compositions made of hydroxyl group-containing compounds such as epoxy resins have excellent corrosion resistance, chemical resistance, 9 mechanical properties, etc., and are therefore used in automobile exteriors, cationic electrodeposition, home appliances, pre-coated metals, etc. Widely used as a baking coating for flat μ electric wires, etc.

However, in general, baking-type paints made of blocked polyisocyanate and hydroxyl group-containing compounds require 14
Heating between 0-200°C 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, it is only slightly coated on thermosetting resin molded products such as phenol, area, melamine, unsaturated polyester, and epoxy, and is used for automobiles and electromagnetic shielding. 1) VC,A
BS, polypropylene.

Currently, molded products such as polyethylene and polycarbonate are lacquer type or room temperature drying type such as two-component urethane.

An object of the present invention is to provide a curable resin composition that has excellent low-temperature curability and excellent coating film properties, and uses thereof.

In view of the above-mentioned circumstances, the present inventors conducted extensive research and found that (1) aminoalkyl acrylate (4) or a copolymer composed of aminoalkyl acrylate and an ethylenically unsaturated monomer; It has been found that when combined with a blocked polyisocyanate compound (2), a coating film that cures at an extremely low temperature of less than 140°C and exhibits excellent physical properties can be obtained. Based on these findings, the present invention has been developed. It was completed.

That is, the present invention provides a curable resin containing (1) an aminoalkyl acrylate module, or a copolymer composed of an aminoalkyl acrylate and an ethylenically unsaturated monomer, and (2) a blocked polyisocyanate compound. This is a coating method characterized by applying a composition and the composition to a substrate, and curing the composition by heating at a temperature of less than 140°C.

The copolymer of the above (1) used in the present invention has the general formula (wherein R1 is hydrogen or a methyl/l/group, and R2 is an alkylene group having 1 to 6 carbon atoms or a hydroxyalkylene group). represents hydrogen or alkyl having 1 to 6 carbon atoms)
It is a copolymer composed of aminoalkyl acrylate or aminoalkyl methacrylate represented by the following formula and an ethylenically unsaturated monomer. Among the above copolymers, those in which R2 is a hydroxyalkylene group are preferred because they have excellent adhesion to the substrate.

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

Aminopropyl acrylate, amino-n-buty-acrylate, aminohexyl acrylate.

N-methyμ aminoethyl acrylate, M-tert-
Acrylates such as buty-aminoethyl acrylate, aminohydroxypropyl acrylate, aminomethyl methacrylate, aminoethyl methacrylate, amino-n-butyl methacrylate), N-methylaminoethyl methacrylate.

N-tert-buty-aminoethyl methacrylate.

Examples include methacrylates such as aminohydroxypropyl methacrylate. The content of these aminoalkyl acrylates in the copolymer is usually about 1 to 40% by weight,
Preferably it is about 5 to 30% by weight.

On the other hand, ethylenically unsaturated monomers include acrylates such as methacrylate, ethyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate, and methacrylates such as methyl methacrylate, ethyl methacrylate, and n-butyl methacrylate. ,
Vinyl acetate.

Fatty acid vinyl esters such as vinyl detetrapionate/L/, aliphatic monoolefins such as ethylene, propylene, and isobutyne, aromatic monoolefins such as styrene and vinyltoluene, and other acrylonitrile, vinyl chloride, and fluoride. You can give things like vinyl. The copolymer may contain one or more of the above monomers,
The content in the copolymer is usually about 60 to 99% by weight, preferably about 70 to 95% by weight.

Aminoalkyl acrylate or a copolymer consisting of aminoalkyl acrylate 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! ! As the polymerization initiator, an oil-soluble free radical-forming catalyst such as α,α'-azobisisobutyronitri-, pency-peroxide, lauroyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide is used. If necessary, it is also possible to use a redox catalyst in combination with an appropriate reducing substance. Furthermore, a small amount of a copolymer molecular weight regulator such as butymu-memucaptan, dodecyl-memucaptan, t-dodecy-memucaptan, beta-memucaptoethanol, etc. may be added. 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 approximately 1,000 to 1,000.
,000. Preferably it is about 5,000 to 500,000. The copolymer can be used as it is, but it may also be ketiminated with an aliphatic ketone or cyclic ketone, such as methi to ethyl .mu.ketone, methi .mu.isobuty .mu.ketone, and cyclohexanone.

The polyisocyanate used in the blocked polyisocyanate compound (2) used in the present invention is as follows:
For example, trimethylene diisocyanate, tetofumethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate), 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, 2,4,4-
1 or 2,2,4-trimethylhexamethylene diisocyanate, dodecamethylene diisocyanate.

2. Aliphatic diisocyanates such as 6-dicyanatomethy-caproate, such as 1,3-cyclopentane diisocyanate, 1.4-V chlorohexane diisocyanate), 1, 3-5"C" hexane diisocyanate, 8 -Methiisocyanato/I/-3,5,5-
trimethyμ cyclohexyμ isocyanate, 4,4
'-methylenebis(cyclohexyl isocyanate),
Methi/L'-2,4-cyclohexane diisocyanate, Methi IV-2. G-cyclohexane diisocyanate)
, 1,4-bis(isocyanatomethyl)cyclohexane, cycloalkylene diisocyanate of 1,3-bis(isocyanatomethyl)cyclohexanato, ta! : Eir! m-phenylene soisocyanate,
p-phenylene diisocyanate), 4,4'-diphenylene diisocyanate), 1,5-naphthalene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4- or 2,6-)lylene diisocyanate, 4,4' -) Aromatic diisocyanates such as luidine diisocyanate, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, such as ω,υ'-diisocyanate 1,3-
Dimethylbenzene, ω, ω′-diisocyanate 1,
4-dimethylbenzene, --.

ω′-diisocyanate 1,4-diethyl-benzene,
1,3-tetofumethyμ xylylene diisocyanate, 1
, 4-tetramethylxylylene diisocyanate.

triphenylmethane-4, 4', 4'-)
! j Ison Anate, 1. a, 5-) Liisocyanate benzene, 1. a.
- Triisocyanates such as ethyl isocyanate m2,6-dicyanatocaderoate, e.g. 4,4
Ketone isocyanates such as '-diphenymu dimethane-methane-2,2,5,5'-ketone isocyanate, polymerized polyisocyanates such as dimers and dimers made of diisocyanate monomers, polymethylene polyphenylene ~polyisocyanate or an excess of the above-mentioned isocyanate compounds and, for example, ethylene glycol~.

Propylene glycol ~, dibu p pylene glycol μ.

Diethylene glycol μ, triethylene glycol μ.

2.2.4-) Rimechi! vi, a-pentanedio-μ
, neobenchi-glyco-, hexanedio-μ, cyclohexane dimetatool, cyclohexanedio-~, hydrogenated bispheno-/L'A, xylylene glyco-y, glycerin, trimethylo-~ethane.

Trimethylo-μ propane, hexane trio-.

Pentaerythri,)-7M, Sovit, Sucrose, Castor oil, Ethylenediamine, Hexamethylene diamine, Ethanol-p amine.

Jetanolamine, triethanolamine, water.

Polyisocyanate adducts obtained by reacting low-molecular active hydrogen-containing compounds such as ammonia and urea, or high-molecular active hydrogen-containing compounds such as various polyether polyols, polyether polyols, acrylic polyols, and epoxy polyols, or these These include allophanate and biuret compounds.

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

The blocking agent used to block the above-mentioned polyisocyanate F includes a blocking agent known to be used for blocking isocyanate,
For example, pheno-y type, tuctum type, active methylene type,
Blocking agents such as Alreco μ type, Maycaptan type, acid amide thread, imide type, amine type, imidazo-μ type, urea type, force μ bamate type, imine type, oxime type, or sulfite type. Any of these may be used, but pheno-μ, octum, alcohol, imine, and oxime blocking agents are particularly advantageous.

By combining the above-mentioned blocked polyisocyanate compound with copolymer (1), it is possible to cure at a much lower temperature than conventional ones, regardless of the type of blocking agent. Specifically, in the case of a pheno-μ block agent, it hardens at a very low temperature of about 50 to 100°C. Lactam-based blocking agents and oxime-based blocking agents are approximately 90~
It cures at 120°C and exhibits excellent storage stability and coating film properties. 1 μco, -y type blocking agent is about 120 ~
It cures at 140°C and has excellent storage stability and coating film properties.

Specific examples of blocking agents include the following:

Pheno-μ-based blocking agents: Pheno-y, RiVcyy, xyleno-〃, nitrobueno-μ, chloropheno-μ, ethyl-phenol-, p-hydroxydipuenyl-, t-butyμphenol-μ, O-isopropyl- Pheno-μ,. -r3ec-butiμphenoμ,
p-no 2 μ pue no μ.

pt-octiμbuenoμ, hydroxybenzoic acid, hydroxybenzoic acid ester μ, etc.

Tectam-based blocking agents: ε-cablocktam, δ-μ reroloctam, γ-butyroloctam, β-propioctam, etc.

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

Alcohol-μ based blocking agents: methanol μ, ethanol μ, n-globi I-Aμ, isoglopy-Aμ, n-buty-P-A-K, isobuty-A-μ, t-butyl-A-μ koiμ, n-ami~apkoμ, t-amip~a~kop, wouriμaμkoρ
, ethylene glyco-mu monomethy-ethyl ether, ethylene glycol monobutylene ethyl ether, ethylene glycol monobutylene ether, diethylene glyco-mu monoethyl ether.

Propylene glyco-monomethyl ether μ, benzyl alpha, methoxymethano-y, glyco-acid, methyl glyco-yate, glyco-ethyl acid.

Glyco-y acid esters such as buty-glyco-y acid.

Lactic acid, methyl lactate, ethyl lactate, butyl lactate, etc. (F)
3M ester, methylo-μ urea, methylolmewomine,
Diacene alcohol, ethylene chlorohydrin, ethylene bromohydrin, 1,3-dichloro-2-globanol, ω-hydroborfyoloycol, acetocyanohydrinato.

Mercaptan-based blocking agent: Petit y mercaptan, Pekin μ me μ captan.

t-butymu-captan, t-dodecyme-captan,
2-MeN-kagtopenzothiazole~, thiopheno-y, methiμthiophenol/l/, ethyl~thiopheno-ρ, etc.

Acid amide blocking agent: acetanilide, acedoanidicito, acetodruid,
Acrylamide, methacrylamide, acetamide, stearamide, benzamide, etc.

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

Amine-based blocking agent Diphenylamine, phenyl-naphthalamine.

Xylidine, N-pheni-xylidine, carbazole Dibutylamine, buty-phenylene-amine, etc.

Imidazo-based blocking agent: imidazo-μ, 2-e, 1,000-p imidazo-μ, etc.

Urea-based blocking agent: urea, thiourea, ethylene urea, ethylene thio is, t
, a-dipheniμ urea, etc.

Powerμ bamate-based blocking agent: N-phenylcarbamate, 2-oxazolidone, etc.

Imine blocking agent: Ethyleneimine, globyleneimine, etc.

Oxime-based blocking agents; foyamidoxime, acedo-doxime, acetoxime, methoxyketoxime, diacetiμ monoxime, benzophenone oxime, cyclohexane oxime, etc.

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

The blocked polyisocyanate compound is produced by reacting the above-mentioned polyisocyanate and a blocking agent by a known method. This reaction can be carried out in a solvent without active hydrogen or without any solvent. Examples of solvents without active hydrogen include ethyl acetate and butylene acetate.

Cellosoμ acetate, force pitot y acetate.

Ester types such as dimethic acid esters of dibasic acids.

Methyμethyμketone, methylisobutylketone.

Examples include ketone solvents such as cyclohexanone, and aromatic solvents such as toluene, xylene, Tsurpets+100, and Somube'/Sen50.

As a specific means for this reaction, the polyisocyanate and the blocking agent are mixed at a ratio of HCO/blocking agent (equivalent ratio) of about 0.
9 to 1.1, preferably about 0.95 to 1.0, the isocyanate monomer and the blocking agent are
After reacting the blocking agent (equivalence ratio) at about 161 to 3.0, preferably about 1.2 to 2.0, the above-mentioned low-molecular active hydrogen-containing compound and/or high-molecular active hydrogen-containing compound is added thereto. Means for reacting isocyanate monomer and low molecular and/or high molecular active hydrogen-containing compound by NGO
/active hydrogen is about 1.5 to 10.0, preferably about 2.0
Examples include means for reacting with a blocking agent after reacting with 7.0. For the reaction, for example, 3
Known catalysts such as grade amines and organic metals may also be used.

The curable resin composition of the present invention can be obtained by blending the above-mentioned copolymer (1) with the blocked polyisocyanate compound (2). The blending ratio is copolymer (1
) The equivalent ratio of the active hydrogen groups in (2) to the regenerated isocyanate groups in the blocked polyisocyanate compound (2) is approximately 0.
．． 3. -3.0, preferably about 0.5-2.0. When the copolymer (1) contains -OH in addition to -NHR3 as an active hydrogen group, it is blended so that the equivalent ratio of the regenerated isocyanate group to -NHR3 is approximately 1, and the OH group is added to the coating film. It is preferable to leave .

The compositions include, for example, pigments and leveling agents.

Additives such as antifoaming agents, dissociation catalysts, and ultraviolet absorbers, or ketone resins, xylene resins, phenoxy resins, 7μ loins, vinylμ resins, and the like may be mixed.

A tough coating film can be obtained by applying this curable resin composition to a substrate and curing it by heating at a temperature of less than 140°C.

Examples of the base material include metals such as iron, 7 μm, copper, and stainless steel, plastic molded products such as phenol, mewomine, urea, unsaturated polyester μ, and epoxy, and inorganic materials.

As a means of painting, for example, Airs Gray.

Airless spray, roll coater, 70-coater,
Examples include guipping coat and electrostatic coating. For heating, use hot air, direct flame, infrared rays or far infrared heaters,
High frequencies are used.

The thickness of the coating film varies depending on the product being coated; for home appliances, it is approximately 30-50μ, and for automobiles, it is approximately 50-8μ.
0μ, and in the case of pre-coated metal, it is about 15 to 80μ.

"Effects of the Invention" The curable resin composition of the present invention cures at several times lower temperatures than commonly used baking paints made of hydroxyl group-containing resins and 10-carbon polyisocyanate compounds. It is useful as paint, adhesive, etc. When heated, crosslinking occurs through the reaction between diisocyanate groups and amino groups, resulting in a coating film with excellent flexibility, chemical resistance, water resistance, gBs resistance, corrosion resistance, etc.; It can be used to coat objects such as inorganic materials, and can be used to coat home appliances, automobiles, building materials, etc.

Hereinafter, the present invention will be explained in more detail with reference to Reference Examples, Examples, and Comparative Examples. In Reference Examples, Examples, and Comparative Examples, parts indicate parts by weight.

Reference example methacrylate (70 parts, n-butyμ acrylate)
A copolymer having a composition of 15 parts of aminoethyl methacrylate and 115 parts of aminoethyl methacrylate, an average molecular weight of ii, s, 10,000, and a non-volatile content of 50% in toluene/glutyl acetate (50150) solution.

Copolymer (B) 30 parts of methacrylate, styrene aoi.

A copolymer consisting of 120 parts of ethyl acrylate and 20 parts of amino-n-butyl methacrylate, with an average molecular weight of 2.
xylene/butylacetate μ (5015) with 50% non-volatile content
0) Solution 70 parts of methyμ methacrylate, 15 parts of n-butyμ acrylate, 15 parts of aminohydroxypropyμ methacrylate
A copolymer with an average molecular weight of 18,000 yen and a non-volatile content of 50% toluene/butylacetate/L/<50150
) Solution-blocked polyisocyanate compound (D) 1, a-bis(isocyanatomethymu)V chlorohexane 582.6
parts, 134.1 parts of trimethylo-propane, 261.1 parts of methyμethylketoxime. A blocked polyisocyanate having the composition of part a, ethyl acetate tv/with a non-volatile content of 60%.
Ethoxyethyl p-acetate) (5015 (l) Solution-blocked polyisocyanate compound (E) 666.9 parts of 3-isocyanatomethyl-3,5,5-1-rimethycyclohexyμ isocyanate.

A blocked polyisocyanate consisting of 1 part of trimethylo-trimethyl, 9.6 parts of C-cablocktam 3B, 1.582.6 parts of 3-bis(incyanatomethyl)cyclohexane, 1.3-bis(incyanatomethyl)cyclohexane solution with 60% non-volatile content; Trimethylo-propane 114.1 parts,
ethyl acetate/I// with a non-volatile content of 60%;
Ethoxyethyl acetate (50750) solution acrylic polyolefin (methyl methacrylate) a O part, styrene 2 (1゜n
-Toluene solution of 60% non-volatile content of acrylic polyol-μ consisting of 130 parts of butyl acrylate and 20 parts of hydroxyethyl μ acrylate Example 1: 862 parts of copolymer (A), 545 parts of blocked polyisocyanate compound (D) , 505 parts of Taibake 0R-90 (titanium oxide, manufactured by Kaisei Sangyo Co., Ltd.), and 194 parts of xylene were kneaded for 24 hours in a Bebu micro-micrometer to obtain a white dill. This white two-name μ was applied to a 0.8 ff thick mild steel plate treated with iron phosphate to a thickness of 40 to 50 μm, and heated to 80 μm at 110°C.
Baking was carried out at 140° C. for 80 minutes. The coating film performance is shown in Table 1.

Example 2 862 parts of copolymer (A), 634 parts of blocked polyisocyanate compound (E), Tybake CR-90540
and 218 parts of xylene were kneaded in the same manner as in Example 1, and baked after application in the same manner to conduct a coating film test.

The test results are shown in Table @1.

Example 3 785 parts of copolymer (B), 545 parts of blocked polyisocyanate compound (D), 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 application in the same manner. The test results are shown in Table 1.

Example 4 785 parts of copolymer (B), 684 parts of blocked polyisocyanate compound (E), Tybake CR-90515
1 part and 213 parts of xylene were kneaded in the same manner as in Example 1, and baked after coating in the same manner as in Example 1. A test was conducted. The test results are shown in Table 1.

Example 5 862 parts of copolymer (A), 416 parts of blocked polyisocyanate compound (F), Tybake CR-90454
200 parts of xylene were kneaded in the same manner as in Example 1, and after coating in the same manner, baking was performed at 110° C. for 30 minutes, and a coating film test was performed. The results are shown in Table 1.

Example 6 880 parts of copolymer (C), blocked polyisocyanate compound (C3545 parts, Tybake CR-90511
220 parts of xylene were kneaded in the same manner as in Example 1, coated in the same manner, and baked at 110° C. for 30 minutes to perform a coating film test. The results are shown in Table 1.

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

(Left below) (Note) Hardness: Damaged hardness ethyl acetate rubbing test by Mitsubishi Pencil UN Engineer Impregnate gauze with ethyl acetate rho and rub the painted surface vigorously.

Bending test Erichsen test using a mandrel bending tester Extrusion height acid resistance test and alkali resistance test using an Erichsen tester Immerse at room temperature to observe changes in the painted surface.

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Claims (1)

[Claims] 1. A curable product prepared by blending (1) a copolymer composed of aminoalkyl acrylate or aminoalkyl methacrylate and an ethylenically unsaturated monomer, and (2) a blocked polyisocyanate compound. Resin composition. 2. A curable resin composition containing (1) a copolymer composed of aminoalkyl acrylate or aminoalkyl methacrylate and an ethylenically unsaturated monomer and (2) a blocked polyisocyanate compound as a base material A coating method characterized by applying the coating to the surface and curing it by heating at a temperature of less than 140°C.