JPH03100069A - Curable coating composition - Google Patents

Abstract

PURPOSE:To obtain the title composition which can be cured at ordinary temperature or by heating or ultraviolet radiation in an atmosphere of air to form a coating film excellent in water resistance and strengths by compounding a specified amount of a specified polymerizable oligomer and a specified amount of a polyurethane. CONSTITUTION:This composition comprises at most 95wt.% polymerizable oligomer having at least two polymerizable unsaturated groups in the molecule (e.g. urethane diacrylate obtained by reacting isophorone diisocyanate with polycaprolactonediol and 2-hydroxyethyl acrylate) or a mixture thereof with a radical-polymerizable vinyl monomer (e.g. methyl acrylate), at most 5wt.% polyurethanepolyene of the formula [wherein R1 is a residue of a mol.wt.<=1000, derived derived by removing the isocyanate groups from a compound having (m) isocyanate groups in the molecule; (m)>=2, R2 is a residue of a mol.wt.<=500, derived by removing the hydroxy groups from a compound having (n) hydroxy groups in the molecule; (n)>=3; and mX(n-1)>=6] and optionally at most 1wt.% metallic drier (e.g. cobalt 2-ethylhexylate) and at most 10wt.% polymerization initiator (e.g. methyl ethyl ketone peroxide).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to novel curable coating compositions in which oligomer/monomer systems can be cured at room temperature, by heating or by ultraviolet light, even in the presence of air.

[Prior Art] Conventionally, compositions mainly composed of oligomers/monomers are
UV-curable paints and electron beam-curable paints are used for a variety of purposes, but for example, when trying to cure a molded object with a complex shape with UV-curable paints, the parts that are not exposed to UV rays are It remains uncrosslinked and sticky forever.

For this reason, even if the uncrosslinked portions are heated in an attempt to crosslink them after irradiation with ultraviolet rays, with conventional oligomer/monomer systems, the surface layer will not be crosslinked and will remain sticky forever. This is because the radical polymerization reaction is generally
This is because the curing reaction is inhibited by the polymerization inhibiting effect of oxygen in the air.

Therefore, if a composition containing an oligomer/monomer system with good air curability, which does not inhibit the curing reaction even in air, can be created, this would be an advantage of ultraviolet curable paints.
Can be cured in a short time, even in areas that have not been irradiated with ultraviolet rays, etc.
A curable composition is obtained.

By the way, various improvements have been made to improve air curing properties. For example, JP-A-62-5471
No. 6 discloses a composition in which a radically polymerizable resin is mixed with a urethane oligomer having an allyl ether group and a (meth)acryloyl group, and also includes U, S, P,
4. 520. No. 184 discloses compositions using oligomers of polyallyl glycidyl ether, but the former has insufficient air curing properties, and the latter has poor water resistance. However, there are various problems, and it has been desired to develop a curable coating composition with excellent air curability.

[Problems to be Solved by the Invention] The purpose of the present invention is to cure the oricomer/monomer in an air atmosphere at room temperature or by heating or by irradiating ultraviolet rays, and to have good water resistance and strong hardening. The present invention relates to a coating composition.

[Means for Solving the Problems] The gist of the present invention is as follows: (a> A polymerizable oligomer containing two or more polymerizable unsaturated groups in one molecule, or a polymerizable oligomer containing two or more polymerizable unsaturated groups in one molecule) A mixture of a polymerizable oligomer containing two or more of the following and a radically polymerizable vinyl monomer, 95% by weight or less, (b) polyurethane boene 5 represented by the following general formula
% by weight or more, RI [NHCOOR2(OCH2-CH-CH
2) n-1] s (1) However, RI is a residue excluding isocyanate of a compound having m isocyanates in one molecule, its molecular weight is 1000 or less, m is an integer of 2 or more, and R2 is 1 A residue excluding the hydroxyl group of a compound having n hydroxyl groups in the molecule, whose molecular weight is 500 or less,
n is an integer of 3 or more, and mx (n-1) is an integer of 6 or more.The composition includes (e) a total bending dryer of 0 to 1% by weight and (d) a polymerization initiator of 0 to 10% by weight.

Component (a) used in the present invention has a usage range of 9
If it is 5% by weight or less, and if it is more than 95% by weight, the polyurethane polyene will inevitably be 5% by weight or less, resulting in poor air curability and undesirable O. Containing 2 or more polymerizable unsaturated groups per molecule. The polymerizable oligomer is not particularly limited, but examples thereof include polybasic acids such as phthalic acid and adipic acid, polyhydric alcohols such as ethylene glycol and butanediol, and (meth)acrylic acid. Polyester poly(meth)acrylate obtained by reaction, epoxy poly(meth)acrylate obtained by reaction of epoxy resin and (meth)acrylic acid, reaction of polyol, polyisocyanate, and hydroxyl group-containing monomer such as 2-hydroxyethyl acrylate and polysiloxane poly(meth)acrylate obtained by the reaction of polysiloxane and (meth)acrylic acid.

In addition, the radically polymerizable vinyl monomer is, for example, (meth)
Methyl acrylate, ethyl (meth)acrylate, (
Propyl meth)acrylate, n-(meth)acrylate
Butyl, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-(meth)acrylate
Nonyl, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, dicyclopentenyl (meth)acrylate, 2-dicyclopentenoxyethyl (meth)acrylate, methoxyethyl (meth)acrylate,
Ethoxyethyl (meth)acrylate, Butoxyethyl (meth)acrylate, Methoxyethoxyethyl (meth)acrylate, Ethoxyethoxyethyl (meth)acrylate, Tetrahydrofurfuryl (meth)acrylate, (meth)acrylic acid 2- Hydroxyethyl, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, (meth)acrylic acid,
(meth)acrylic acid and its esters such as (meth)acryloylmorpholine, N-vinyl-2-pyrrolidone, N
-Vinylimidazole, N-vinylcaprolactam, styrene, α-methylstyrene, vinyltoluene, allyl acetate, vinyl acetate, vinyl propionate, vinyl benzoate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate ) rate, triallyl cyanurate, l-lysine isocyanate, triallyl formal (1,3,5-triacryloylhexahydro-S-triazine), polyethylene glycol di(meth)acrylate, polybutylene glycol di(meth)acrylate ) acrylate, etc.

The radically polymerizable vinyl monomer can substitute up to 60% by weight of the aforementioned polymerizable oligomer containing two or more polymerizable unsaturated groups in one molecule. If it exceeds 60% by weight, coating film performance such as water resistance and solvent resistance will deteriorate.

The polyurethane polyene of general formula (I) used in the present invention is composed of polyisocyanates such as diisocyanates, triisocyanates, vinylets thereof, multimers, or adducts with polyols, and one hydroxyl group in one molecule. It is synthesized by reaction with a compound having two or more allyl ether groups, and the molecular weights of the residues R1 and R2 excluding each active group are 1000 or less and 500 or less, respectively.
It is as follows.

Specific examples of polyisocyanates include I-lylene diisocyanate, ethylene diisocyanate, 1,2-diisocyanatopropane, 1,3-diisocyanatopropane, 4,4-diphenylmethane diisocyanate, xylylene diisocyanate, and tetramethylxylylene diisocyanate. Isocyanate, hexamethylene diisocyanate, lysine isocyanate, 4,4-methylenebis(cyclohexyl)isocyanate, methylcyclohexane 2°4-diisocyanate, methylcyclohexane 2°6-
Diisocyanate, 1. 3-bis(isocyanatomethyl)cyclohexane, inphorone diisocyanate, trimethylhexamethylene diisocyanate, tetramethylene diisocyanate, dimer acid diisocyanate,
Examples include diisocyanates such as 2-isocyanatoethyl 2,6-di-natohexanoate, monobiuret triisocyanates, polymers thereof, and adducts thereof with polyols.

Specific examples of polyols used in the adduct include ethylene glycol, propylene glycol, butylene glycol, polyethylene glycol, polypropylene glycol, polybutylene glycol, polytetramethylene glycol, trimethylolpropane, polytrimethylolpropane, pentaerythol, and polyol. Alcohols and polyether polyols such as pentaerythritol, sorbitol, mannitol, glycerin, polyglycerin,
Examples include polyester polyols synthesized from polyhydric alcohols and polybasic acids, polyester polyols such as polycaprolactone polyols, and the like.

Specific examples of compounds having one hydroxyl group and two or more allyl ether groups in one molecule include trimethylolmethane diallyl ether, trimethylolethane diallyl ether, trimethylolpropane diallyl ether, ditrimethylolpropane triallyl ether, Glycerin diallyl ether, diglycerin triallyl ether, pentaerythritol triallyl ether, dipentaerythritol pentaallyl ether, and trimethylolmethane, trimethylolethane, trimethylolpropane, ditrimethylolpropane, glycerin,
Polyols such as diglycerin, pentaerythritol, and dipentaerythritol include di-, tri-, and pentaallyl ethers of alkylene oxide adduct polyols such as ethylene oxide, propylene oxide, and tetramethylene oxide.

The reaction between the polyisocyanate and the monohydroxy polyallyl ether compound can be carried out by heating at 60 to 70°C for several hours using a tin-based catalyst such as dibutyltin dilaurate so that the isocyanate and hydroxyl groups are approximately equal. finish.

The number of allyl ether groups in the polyurethane polyene is 6
Must be greater than or equal to 1. If the number is less than 6, curing properties in air will be insufficient, which is not preferable.

The content of polyurethane polyene is 5% by weight or more, and if it is less than 5% by weight, curing properties at room temperature or under heat in an air atmosphere will be poor.

The metal dryer (c) is effective in significantly accelerating the curing of the composition of the present invention. Specific examples of metal dryers include cobalt, manganese, barium, cerium,
Salts of metals such as lead, zinc, calcium, titanium, zirconium, iron, copper, and tin and carboxylic acids such as acetylic acid, naphthenic acid, octylic acid, and tall oil fatty acids can be collected.

The amount of metal dryer added is 0 to 1% by weight.

If it exceeds 1% by weight, problems such as coloring and fading will occur, and storage stability will deteriorate, which is not preferable.

The metal dryer is typically used as a solution in a suitable solvent for the purpose of dispersing it throughout the composition.

Although the curing mechanism during coating film formation has not been completely elucidated, using only a metal dryer may result in a coated surface with poor smoothness, in which case a polymerization initiator may be added.

The polymerization initiator (d) is a free radical polymerization initiator, and specific examples thereof include benzoyl peroxide, lauroyl peroxide, cumene hydroperoxide, 1-butyl hydroperoxide, etc. Oxide, azobisisobutyronitrile, 2
．． 2-azobis(2-methylbutyronitrile), 2.2
- Primary azo compounds such as azobis(2-methylpropane) can be mentioned.

The usage range of the polymerization initiator is 0 to 10% by weight. 10
If it exceeds % by weight, the stability of the coating material decreases, which is not preferable.

When the composition of the present invention is cured by ultraviolet irradiation, it is preferable to incorporate a photoinitiator into the composition. Its blending amount is 0.801 to 10% by weight.

Specific examples include benzophenone, benzoin, isobutyl ether, benzoin isopropyl ether,
Benzyldimethylmetal, 2I2-jethoxyacetophenone, 2,2-dibutoxyacetophenone, 1-hydroxycyclohexylphenylketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2
-Methyl-1-[4-(methylthio)phenyl2-
Morpholino-propanone-1,2-benzyl-2-dimethylamine-1-(4-morpholinophenyl)-butanone-1, methylphenylglyoxylate, ethylphenylglyoxylate, 2-chlorothioxanthone, 2.4- Diethylthioxanthone, 2.4-diisopropylthioxane, 2. 4. Examples include 6-trimethylbenzoyldiphenoylphosphine oxide.

The composition of the present invention may optionally contain a leveling agent, a slip agent, an antifoaming agent, an anti-repellent agent, a wetting agent, a dispersant, an anti-settling agent, an anti-sagging agent, an ultraviolet absorber, an antioxidant, a polymerization inhibitor, Various additives such as coupling agents and volatile organic solvents can be added to adjust the viscosity.

Furthermore, dyes, pigments, etc. can be added to the composition of the present invention for the purpose of coloring it.

The composition of the present invention can be cured by simply leaving it in the air after being coated on the object to be coated, and its curing can be accelerated by heating. It can also be rapidly cured by irradiating it with ultraviolet rays such as a mercury lamp, an ultra-high pressure mercury lamp, a xenon lamp, a gallium lamp, a metal halide lamp, or sunlight.

The coating film formed from the composition of the present invention can be cured by heating at room temperature or relatively low temperature, so it can be applied to plastic products that would otherwise deform and deteriorate when heated at high temperatures, making it unnecessary to heat at high temperatures. Since there is no metal, it is possible to save energy, and it can also be applied to wood, glass, inorganic materials, etc., and it is also possible to realize integral coating of metal and plastic on automobile exterior panels.

The present invention will be explained below with reference to Examples.

1 mol of hexamethylene diisocyanate trimer and 0.001 mol of dibutyltin dilaurate of polyurethane polyene were charged into a reaction vessel, the temperature was raised to 70°C, 3 mol of trimethylolpropane diallyl ether was added dropwise over 1 hour, and then, The mixture was reacted at the same temperature for 5 hours to synthesize the desired polyurethane polyene (A) having 6 allyl groups in one molecule.

Production Example 1 Using 1 mol of polyurethane polyene "12 hexamethylene diisocyanate biuret, 0.001 mol of dibutyltin dilaurate, and 3 mol of pentaerythritol triallyl ether.
A target polyurethane polyene (B) having 9 allyl groups in one molecule was synthesized in the same manner as above.

3 mol of polyurethane polyene 3 isophorone diisocyanate and 0.002 mol of dibutyltin dilaurate were charged into a reaction vessel, and the temperature was raised to 70°C, and 1 mol of trimethylolpropane was added to this at 60°C.
After heating and keeping it warm to make it liquid, it was added dropwise over 1 hour, then reacted at the same temperature for 3 hours, and then 3 mol of ditrimethylolpropane triallyl ether was added dropwise over 1 hour, and after the dropwise addition, the mixture was allowed to react for 5 hours. A target polyurethane polyene (C) having nine allyl groups in one molecule was synthesized.

Production of polyurethane polyene 4 Using 1 mole of inphorone diisocyanate dimer, 0.001 mole of dibutyltin dilaurate, and 3 moles of bentaerythritol ethyleneoxide-modified triallyl ether, one molecule of interest was prepared in the same manner as in Production Example 1. A polyurethane polyene (D) having 9 allyl groups therein was synthesized.

5. Using 1 mol of xylylene diisocyanate, 0.001 mol of dibutyltin dilaurate, and 2 mol of trimethylolpropane diallyl ether of polyurethane polyene. A polyurethane polyene (E) having four groups was synthesized.

Charge 1.0 mol of chrycerin, 1.0 mol of 2-hydroxyethyl acrylate, and 1.0 mol of trimethylolpropane diallyl ether into a reaction vessel, add 2.0 mol of isophorone diisocyanate dropwise while keeping the temperature below 50°C, and react. A desired urethane oligomer (F) containing an allyl ether group and a (meth)acryloyl group was obtained.

Preparation of oligomer of polyallyl glycidyl ether 41.6 g of ethylene glycol and 5 g of boron trifluoride ethyl ether as a catalyst were placed in a reaction vessel, heated to 80°C, and 856 g of allyl glycidyl ether was added dropwise over 2 hours. After that, the mixture was cooled to 20°C, 3 g of catalyst was added, the temperature was raised to 80°C again, 856 g of allyl glycidyl ether was added dropwise over 2 hours, the reaction was continued at the same temperature for 30 minutes, and the mixture was cooled to room temperature. The desired oligomer (G) of polyallyl glycidyl ether containing an OH group was obtained.

[Example 1] 50 parts by weight of urethane diacrylate (U) obtained by the reaction of inphorone diisocyanate, polycaprolactone diol, and 2-hydroxyethyl acrylate, 50 parts by weight of polyurethane polyene (A), 71 parts by weight of cobalt 2-ethylhexylate. A composition consisting of 0.2 parts by weight of a 12% cyclohexane solution and 2 parts by weight of methyl ethyl ketone peroxide was applied to a tin plate to a film thickness of 40 μm, and when left at room temperature for 7 days, the coating was completely cured. did. Table 1 shows the performance evaluation results of this coated board.

[Example 2 80 parts by weight of urethane diacrylate (U) obtained by the reaction of coinphorone diisocyanate, polycaprolactone diol, and 2-hydroxyethyl acrylate, 20,111 parts of polyurethane polyene (B), 12% of cobalt 2-ethylhexylate A composition consisting of 0.8 parts by weight of Cyclohexan solution and 1 part by weight of cyclohexanone peroxide was applied to a tin plate to a film thickness of 40 μm,
When heated at 80° C. for 30 minutes, the coating film was completely cured. Table 1 shows the performance evaluation results of this coated board.

[Example 3] 60 parts by weight of urethane diacrylate (U) obtained by the reaction of inphorone diisocyanate, polycaprolactone diol, and 2-hydroxyethyl acrylate, 40 parts by weight of polyurethane polyene (C), and cobalt 2-ethylhexylate. 12% cyclohexane solution 0. A composition consisting of 4 parts by weight of methyl ethyl ketone peroxide and 2 parts by weight of methyl ethyl ketone peroxide was applied to a tin plate to a film thickness of 40 μm and left at room temperature for 7 days, whereupon the coating film was completely cured.

Table 1 shows the performance evaluation results of this coated board.

[Example 4] 70 parts by weight of epoxy diacrylate (e) obtained by reaction of bisphenol A type epoxy resin and acrylic acid,
Polyurethane polyene (D) 30 heavy jlL 12% cyclohexane solution of cobalt 2-ethylhexylate 0.
A composition consisting of 4 parts by weight and 3 parts by weight of t-butylperoxy-2-ethylhexanoate was coated on a tin plate with a film thickness of 40%.
The coating film was coated to a thickness of .mu.m and heated at 70.degree. C. for 30 minutes, and the coating film was completely cured. Table 1 shows the performance evaluation results of this coated board.

[Example 5] 40 parts by weight of epoxy diacrylate (e) obtained by reaction of bisphenol A type epoxy resin and acrylic acid,
Polyurethane polyene (A) 60 weight Jll, 12% cyclohexane solution of cobalt 2-ethylhexylate 0.4
A composition consisting of 1 part by weight and 2 parts by weight of methyl ethyl ketone peroxide was applied to a tin plate to a film thickness of 40 μm, and heated at 60° C. for 30 minutes, after which the coating film was completely cured. Table 1 shows the performance evaluation results of this coated board.

[Example 6] A composition consisting of 60 parts by weight of urethane diacrylate (U) obtained by the reaction of coinphorone diisocyanate, polycaprolactone diol, and 2-hydroxyethyl acrylate and 40 parts by weight of polyurethane polyene (B) was applied to a tin plate. Coat to a film thickness of 40 μm and heat at 140'C.
When heated for 30 minutes, the coating film was completely cured. Table 1 shows the performance evaluation results of this coated board.

[Example 7] 70 parts by weight of polyester diacrylate (a) obtained by the reaction of a condensate of adipic acid and neopentyl glycol with acrylic acid, 12 parts by weight of polyurethane polyene (B) ao weight s, and 12 parts by weight of cobalt 2-ethylhexylate. % cyclohexane solution, 2 parts by weight of methyl ethyl ketone peroxide was applied to a tin plate to a film thickness of 40 μm, and when heated at 70°C for 30 minutes, the coating was completely cured. . Table 1 shows the performance evaluation results of this coated plate.

[Example 8] Polysiloxane dimethacrylate (S
), 1 part by weight of 70 parts by weight, 30 parts by weight of polyurethane polyene (C), 4 parts by weight of 12% cobalt 2-ethylhexylate I&O dissolved in cyclohexane, and 2 parts by weight of methyl ethyl ketone peroxide.
The coating film was completely cured when the coating was applied at a thickness of m and heated at 70°C for 30 minutes. Table 1 shows the performance evaluation results of this coated board.

[Comparative Example 1] 70 parts by weight of urethane diacrylate (U) obtained by the reaction of inphorone diisocyanate, polycaprolactone diol, and 2-hydroxyethyl acrylate, 30 parts by weight of polyurethane polyene (E), 11 parts by weight of cobalt 2-ethylhexylate. 1ffl of 12% cyclohide beef starch 00
A composition consisting of 4 parts by weight and 2 parts by weight of methyl ethyl ketone peroxide was applied to a tin plate to a film thickness of 40 μm and heated at 70°C for 30 minutes, but the coating did not harden and tack remained on the surface. Ta.

[Comparative Example 2] Urethane diacrylate (U) obtained by reaction of isophorone diisocyanate, polycaprolactone diol, and 2-hydroxyethyl acrylate, 100 weight jlN, 2
- 0.4 parts by weight of 12% cyclohexane solution of cobalt ethylhexylate, 2 parts by weight of methyl ethyl ketone peroxide
The composition consisting of parts by weight was applied to a tin plate to a film thickness of 40 μm and heated at 70° C. for 30 minutes, but the coating did not harden and tack remained on the surface.

[Comparative Example 3] 70 parts by weight of urethane diacrylate (11) obtained by the reaction of inphorone diisocyanate, polycaprolactone diol, and 2-hydroxyethyl acrylate, 30 parts by weight of oligomer (F), 12% of cobalt 2-ethylhexylate. A composition consisting of 0.4 parts by weight of cyclohexane solution and 2 parts by weight of methyl ethyl ketone peroxide was applied to a tin plate to a film thickness of 40 μm, and heated at 70°C for 30 minutes.
When heated for 0 minutes, the coating film was completely cured. Table 1 shows the performance evaluation results of this coated board.

[Comparative Example 4] 70 parts by weight of urethane diacrylate (U) obtained by the reaction of inphorone diisocyanate, polycaprolactone diol, and 2-hydroxyethyl acrylate, 30 parts by weight of oligomer (G), and 12 parts by weight of cobalt 2-ethylhexylate. A composition consisting of 0.4 parts by weight of % cyclohexane solution and 2 parts by weight of methyl ethyl ketone peroxide was applied to a tin plate to a film thickness of 40 μm, and heated at 70°C for 3 parts by weight.
When heated for 0 minutes, the coating film was completely cured. Table 1 shows the performance evaluation results of this coated board.

C.Effects of the Invention As detailed above, the composition of the present invention can be treated in an air atmosphere at room temperature or by heating or by irradiating with ultraviolet rays.
Because the oligomer/monomer can be cured, it has good water resistance, and can provide a strong coating film, so it is suitable for painting objects that cannot be cured at high temperatures or objects that have complex shapes. It is particularly effective, and its effects are extremely large.

Claims (1)

[Scope of Claims] (a) A polymerizable oligomer containing two or more polymerizable unsaturated groups in one molecule, or a polymerizable oligomer containing two or more polymerizable unsaturated groups in one molecule and radical polymerization 95% by weight or less, (b) polyurethane polyene 5 represented by the following general formula;
Weight% or more, R_1-[NHCOO-R_2-(O-CH_2-CH
=CH_2)_n_-_1]_m(I) However, R_1
is the residue excluding isocyanate of a compound having m isocyanates in one molecule, its molecular weight is 1000 or less, m is an integer of 2 or more, and R_2 is the hydroxyl group of a compound having n hydroxyl groups in one molecule. residues to be removed, the molecular weight of which is 500 or less, n is an integer of 3 or more, m x (n-1) is an integer of 6 or more, (c) metal dryer 0 to 1% by weight, and (d) polymerization initiator 0 ~10% by weight.