JPH0488009A - Thermosetting composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition, composed of a specific acrylate- bases composition, an acrylic copolymer and a curing agent composed of an amino resin, etc., excellent in hardness, beautiful decorativeness, solvent and weather resistance with good acid and scuff resistance. CONSTITUTION:The objective composition is composed of (A) a composition composed of (i) 50-100 pts.wt. aliphatic and/or alicyclic urethane (meth)acrylate having >=3 (meth)acryloyl groups in one molecule, (ii) 0-50 pts.wt. radical- polymerizable compound, containing >=3 (meth)acryloyl groups in one molecule without any urethane bond and having >=300 molecular weight and (iii) 0.1-3.0 pts.wt. radical polymerization initiator, (B) an acrylic copolymer having carboxyl groups and hydroxyl groups and (C) a curing agent selected from an amino resin and a polyisocyanate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a thermosetting composition having excellent hardness, cosmetic properties, solvent resistance, and weather resistance, as well as good acid resistance and scratch resistance.

[Prior art and its problems It is generally known that coradically polymerizable unsaturated group-containing oligomers are cured by heating using a radical polymerization initiator, but these cured products are not inhibited by oxygen. It was thought that the hardness was insufficient due to the exposure to water, and that it did not have good solvent resistance, weather resistance, etc. Therefore, in polymerizable oligomer curing systems, it has been essential to use a photosensitizer and ultraviolet irradiation in combination.

However, even when heat-cured, the present inventors have achieved hardness and weather resistance similar to those found in acrylic resins by using radically polymerizable oligomers that have specific bonds and have a molecular weight above a certain level. can be expressed,
In addition, it has been found that good performance can be obtained in terms of acid resistance and scratch resistance, which were low in melamine crosslinked systems.

That is, the purpose of the present invention is to improve hardness, cosmetic properties, solvent resistance,
It is an object of the present invention to provide a thermosetting composition having excellent weather resistance and good acid resistance and scratch resistance.

[Means for Solving the Problems] The gist of the present invention is as follows: (a) an aliphatic and/or alicyclic urethane (meth)acrylate containing three or more (meth)acryloyl groups in one molecule; 50 to 100 parts by weight, (b) 0 to 50 parts by weight of a radically polymerizable compound containing three or more (meth)acryloyl groups in one molecule, containing no urethane bond, and having a molecular weight of 300 or more, and (C) The radical polymerization initiator is added in an amount of 0.1 to 3 parts by weight based on 100 parts by weight of the total amount of components (a) and (b). A thermosetting composition comprising a composition (A) consisting of ONN Gunbe, an acrylic copolymer having a carboxyl group and a hydroxyl group (B), and a curing agent (C) selected from amino resins and polyisocyanates. It's in things.

The above composition will be explained below.

The aliphatic and/or alicyclic urethane (meth)acrylate (a) containing three or more (meth)acryloyl groups in one molecule, which is the first component of the composition (A), is triisocyanate alone, diisocyanate, It can be synthesized by reacting a polyisocyanate such as a biuret, a multimer, or an adduct of triisoocyanate with a polyol, and a hydroxyl group-containing monomer. The compound (a) has a total amount of 10% of the components (a) and (b) in the composition (A) of the present invention.
Contains 50 to 100 parts by weight relative to 0 parts by weight,
If the amount is less than 50 parts by weight, weather resistance will deteriorate, which is not preferable.

Specific examples of polyisocyanates include ethylene diisocyanate, 1. 2-diisocyanatopropane, 1.
3-diisocyanatopropane, 4゜4-diphenylmethane diisocyanate, hexamethylene diisocyanate, lysine isocyanate, 4.4-methylenebis(
cyclohexyl) isocyanate, methyl cyclohegyusan 2. 4 diisocyanate, methyl cyclo to beef san 2
．． Diisocyanates such as 6-diisocyanate, 1,3-bis(incyanatomethyl)cyclohexane, inphorone diisocyanate, trimethylhexamethylene diisocyanate, tetramethylene diisocyanate, dimer acid diisocyanate, simple triisocyanates, biuret, and large amounts thereof Examples include the compound and its adduct with a polyol. Specific examples of polyols used in the adduct include ethylene glycol, propylene glycol, butylene glycol, polyethylene glycol, polypropylene glycol, polyphtylene gellicol, polytetramethylene glycol, trimethylolpropane, polytrimethylolpropane, pentaerythritol, Examples include alcohols and polyether polyols such as polypentaerythritol, sorbitol, mannitol, glycerin, and polyglycerin, polyester polyols synthesized from polyhydric alcohols and polybasic acids, and polyester polyols such as poly=4-caprolactone polyol.

Examples of hydroxyl group-containing vinyl monomers include 2-hydroxyethyl (ink) acrylate, 2-hydroxypropyl (
meth)acrylate, 3-hydroxypropyl(meth)
acrylate, hydroxyalkyl (meth)acrylates such as 4-hydroxybutyl (meth)acrylate,
2-Hydroxyethyl (such as adducts of 2-hydroxyethyl (meth)acrylate and ethylene oxide, adducts of 2-hydroxyethyl (meth)acrylate and propylene oxide, adducts of 2-hydroxyethyl (meth)acrylate and ε-caprolactone, etc. Examples include adducts of meth)acrylate and organic lactones.

The reaction between polyisocyanate and hydroxyl group-containing monomer is
A tin-based catalyst such as dibutyltin dilaurate is used so that incyanate and hydroxyl groups are approximately equal to 60 to 7
Finish by heating for several hours at 0°C.

The radically polymerizable compound which is the second component of the composition (A) (
b) has a molecular weight of 300 or more and does not have a urethane bond, and is preferably 0 to 50 parts by weight based on 100 parts by weight of the total amount of components (a) and (b) in the composition of the present invention. is added in an amount of 10 to 40 parts by weight, and if it exceeds 50 parts by weight, weather resistance deteriorates, which is not preferable. Specifically, polyester poly(meth)acrylate obtained by the reaction of polybasic acids such as phthalic acid and adipic acid, polyhydric alcohols such as ethylene glycol and butanediol, and (meth)acrylic acid compounds, and epoxy resins ( Epoxy poly(meth)acrylate obtained by reaction with meth)acrylic acid compound,
Examples include polysiloxane poly(meth)acrylate obtained by the reaction of polysiloxane and a (meth)acrylic acid compound, and polyamide poly(meth)acrylate obtained by the reaction of polyamide and a (meth)acrylic acid compound.

The radical polymerization initiator (C) is added in an amount of 0.1 to 3.0 parts by weight based on 100 parts by weight of the total amount of components (a) and (b) in the composition (A) of the present invention. If the amount is less than 1 part by weight, sufficient coating hardness cannot be obtained, and 3. If it exceeds 0 parts by weight, the stability of the coating material decreases, which is not preferable. Examples of the polymerization initiator used here include benzoyl peroxide, cumene hydroperoxide, di-t-butylhydrocarbon oxide, dicumyl peroxide, t-butyl peracetate, t-butyl perbenzoate, and t-butyl hydroperoxide. Peroxides such as peroxide, azobisisobutyronitrile, 2.2-azobis(2
-methylbutyronitrile), 1゜1-azobis (cyclohexane-1-carbonitrile), 2,2-azobis (214-dimethylvaleronitrile), 2,2-azobis (2-methylpropane), etc. Examples include azo compounds, but are not particularly limited.

Next, component (B) and component (C) will be explained. In forming a paint film, it is difficult to obtain sufficient properties in terms of sag control, adhesion to substrates and painted surfaces, etc. when using the above composition (A) alone; A)
This problem can be effectively solved by mixing it with

The carboxyl group in the acrylic copolymer that is component (B) functions as a catalyst, and the hydroxyl group functions as a crosslinking point, (
The curing reaction proceeds using the amino resin or polyisocyanate as the component C) as a crosslinking agent.

Carboxyl-containing vinyl monomers and hydroxyl group-containing vinyl monomers are used as monomers constituting the acrylic copolymer (B). Specific examples of carboxyl-containing vinyl monomers include (meth)acrylic acid, itaconic acid,
fumaric acid, crotonic acid, maleic acid, monomethyl itaconate, monobutyl itaconate, monomethyl maleate,
Examples include monobutyl maleate. Specific examples of hydroxyl group-containing vinyl monomers include hydroxyl group-containing vinyl monomers such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Alkyl (meth)acrylates, 2
- 2-hydroxyethyl such as adducts of hydroxyethyl (meth)acrylate and ethylene oxide, adducts of 2-hydroxyethyl (meth)acrylate and propylene oxide, adducts of 2-hydroxyethyl (meth)ticrylate and ε-caprolactone, etc. Examples include adducts of (meth)acrylate and organic lactones. Furthermore, other copolymerizable vinyl monomers include styrene, α-methylstyrene, styrene derivatives such as vinyltoluene,
Polymerizable unsaturated nitriles such as (meth)acroyl nitrile, vinyl esters such as vinyl acetate and vinyl propionate, N-methoxymethyl (meth)acrylamide, N
- N-alkoxy substituted amides such as ethoxymethyl (meth)acrylamide and N-butoxymethyl (meth)acrylamide, glycidyl (meth)acrylate, (meth)allyl glycidyl ether, metaglycidyl (meth)
Epoxy group-containing monomers such as acrylic acid esters, basic monomers such as dimethylaminoethyl (meth)acrylic acid, diethylamine ethyl (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate,
n-propyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, (
2-ethylhexyl meth)acrylate, lauryl (meth)acrylate, dodecyl (meth)acrylate, (
Examples include (meth)acrylic acid esters such as stearyl meth)acrylate.

The method for polymerizing the acrylic copolymer (B) in the present invention may be any known polymerization method such as solution polymerization, bulk polymerization, emulsion polymerization, etc., but solution polymerization is particularly preferred. In the case of solution polymerization, the monomer mixture is copolymerized in the presence of an organic solvent and a polymerization initiator.

Specific examples of the amine resin as component (C) include aminotriazine, urea, dicyandiamide, and N.

Examples include alkyl etherification of methylolated N-ethylene urea with cyclohexanol or an alkanol having 1 to 6 carbon atoms, and in particular those obtained from aminotriazine, such as methyl etherified melamine resin, butyl etherified melamine. Resin etc. are suitable.

Further, the polyisocyanate compound used as component (C) is a compound having two or more incyanate groups in one molecule, and specifically, a di(or tri)isocyanate compound, for example, tetramethylene. Diisocyanate, hexamethylene diisocyanate, decamethylene diisocyanate, ethylene diisocyanate, isophorone diisocyanate, aliphatic incyanate such as lysine diisocyanate, xylylene diisocyanate, methylxylylene diisocyanate, phenylene diisocyanate, tolylene diisocyanate, 4. 4'
-methylenebis(phenylisocyanate), 3,3°
-Diisocyanates Aromatic incyanates such as 1,4 dimethylbenzene and triphenylmethane diisocyanate, and fats such as 1-methyl-2,4-diisocyanate cyclohexanone, 4,4-methylenebis(cyclohexyl isocyanate), and cyclohexane diisocyanate. Examples include cyclic isocyanates, hexanol diisocyanate isocyanurate, and the like.

The addition ratio of component (B) and component (C) can be arbitrarily selected depending on the purpose and is not particularly limited. ,
Particularly preferred is a range of 60/40 to 90/10.

In addition, the mixing ratio of components (A), (B), and (C) is usually such that A/(B+C) is 90/10 to 20 in terms of weight ratio.
/80 range. Further, from the viewpoint of curing speed and coating performance, 80/20 to 50150 is preferable. -9 for boat fishing
If it is larger than 0/10, the base layer tends to return to the clear layer, and if it is smaller than 20/80, the coating film performance tends to deteriorate.

The thermosetting composition of the present invention has a temperature of 15 to 45
This can be achieved by changing the curing conditions for a few minutes. In addition, the cured product of the composition of the present invention has excellent hardness, cosmetic properties, weather resistance, and solvent resistance, as well as good acid resistance and scratch resistance.
It is useful as a paint or coating agent for the surfaces of inorganic materials (iron plates, tin plates, galvanized iron plates, aluminum plates, galvanized steel plates, roof tiles, etc.) and organic materials (wood, paper, plastic, organic paint films, etc.).

Furthermore, surface conditioners, anti-corrosion agents, ultraviolet absorbers, antioxidants, organic solvents, and other additives may be added as necessary.

The present invention will be explained in detail below using examples.

Production example of urethane (meth)acrylate (a)-1> 1 mol of hexamethylene diisocyanate biuret and 0.002 mol of dibutyltin dilaurate were added to a reaction vessel, and after raising the temperature to 70°C, 3 mol of propylene glycol was added. It was added dropwise for 1 hour, and then reacted for 3 hours at the same temperature. Furthermore, 3 mol of 2-hydroxypropyl methacrylate was added dropwise for 1 hour, and after the dropwise addition, the reaction mixture was reacted for 5 hours to form urethane (meth)acrylate (a)- I got 1.

Urethane (meth)acrylate (a) -2tDfl
J Example Production Example-1 except that 0.001 mol of dibutyltin dilaurate was used instead of 0.002 mol, butylene glycol was used instead of propylene glycol, and 2-hydroxybutyl acrylate was used instead of 2-hydroxypropyl methacrylate. Similarly, urethane (meth)
Acrylate (a)-2 was synthesized.

Production example of urethane (meth)acrylate (a)-3> Inphorone diisocyanate biuret is used instead of methylene diisocyanate biuret, 0.001 mol of dibutyltin dilaurate is used, and polyethylene glycol is used instead of propylene glycol. Urethane (meth)acrylate (a)-3 was synthesized in the same manner as in Production Example-1 except for this.

Production example of urethane (meth)acrylate (a)-4> 1 mol of hexamethylene diisocyanate and 0.001 mol of dibutyltin dilaurate were added to a reaction vessel, and 70
After raising the temperature to °C, 2 mol of polybutylene glycol was added dropwise over 1 hour, and then reacted at the same temperature for 3 hours. Furthermore, 2 mol of 2-hydroxyethyl acrylate was added dropwise over 1 hour. React for 5 hours to form urethane (meth)
Acrylate (a)-4 was obtained.

Production example of acrylic copolymer (B)〉Place Tsurpets #10 in a container equipped with a stirrer, temperature control device, and condenser.
0 was added in an amount of 53.3 parts by weight. While stirring, increase the temperature to 1
20°C and then add the following monomer mixture 10
0 parts by weight, 2 parts by weight of azobisin butyronitrile and t-
2 parts by weight of butylperoxyisopropyl carbonate was added dropwise over 3 hours. Thereafter, 0.1 part by weight of azobisisobutyronitrile was added four times at 30 minute intervals. Next, the mixture was heated and stirred at 120° C. for 2 hours to increase the reaction rate, and then 13.3 parts by weight of n-butyl acetate was added to terminate the reaction to obtain an acrylic copolymer (B).

[Monomer composition of acrylic copolymer] Styrene methacrylate n-butyl methacrylate t-butyl methacrylate 2-ethylhexyl methacrylate 2-hydroxyethyl methacrylate 25 parts by weight 3 parts by weight 20 parts by weight 5 parts by weight 29 parts by weight 18 parts by weight Unit double placement unit <Example of manufacturing a mixture of components (B) and (C)> Components (B) and (C) are mixed in the blending ratio shown below to form mixtures (1) and (2). I got it.

a): Melamine resin manufactured by Mitsui Toatsu Chemical Co., Ltd. b) Polyisocyanate manufactured by Nippon Polyurethane Co., Ltd. (Examples 1 to 6, Comparative Examples 1 to 7) After degreasing the steel plate, the various types shown in Table 1 The compositions were coated onto the above-mentioned steel plates to a dry film thickness of 35 μm, and after being left at room temperature for 10 minutes, they were baked under the curing conditions shown in Table 1. The coating film performance evaluation results of the obtained paint films are shown in Table 2, and the examples have better hardness, cosmetic properties, solvent resistance, weather resistance, acid resistance, and scratch resistance than those of the comparative examples. Both were excellent in terms of gender.

[Effects of the Invention] As detailed above, the composition of the present invention can be cured by heat, and the resulting cured coating film has good hardness, cosmetic properties,
It has excellent solvent resistance, weather resistance, acid resistance, and scratch resistance, and its industrial significance is extremely high.

Claims (1)

Scope of Claims: (a) 50 to 100 parts by weight of aliphatic and/or alicyclic urethane (meth)acrylate containing three or more (meth)acryloyl groups in one molecule; (b) in one molecule 0 to 50 parts by weight of a radically polymerizable compound containing three or more (meth)acryloyl groups and no urethane bonds and having a molecular weight of 300 sides, and (c) a radically polymerizable initiator to component (a) and ( b) A composition consisting of 0.1 to 3.0 parts by weight based on 100 parts by weight of the total amount of components (A), an acrylic copolymer having a carboxyl group and a hydroxyl group (B), and an amino resin and a polyisocyanate. A thermosetting composition comprising a curing agent (C) selected from the following.