JPH0488012A - thermosetting composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention provides a thermosetting material that has excellent hardness, cosmetic properties, solvent resistance, weather resistance, and flexibility, as well as good acid resistance and scratch resistance. Regarding the composition.

[Conventional techniques and their problems] Conventionally, the formation of coating films using radically polymerizable unsaturated group-containing oligomers requires the combined use of photosensitizers and ultraviolet irradiation, and in the curing reaction by heating, hardness, solvent resistance, It was thought that a cured coating film with good properties such as weather resistance could not be obtained.

However, the present inventors have found that even when cured by heat, if the radically polymerizable oligomer has specific bonds and has a molecular weight above a certain level, it will exhibit hardness and weather resistance similar to those seen in acrylic resins. It has been found that good results can be obtained in terms of acid resistance and scratch resistance, which were low in melamine crosslinked systems.

That is, an object of the present invention is to provide a thermosetting composition that has excellent hardness, cosmetic properties, solvent resistance, weather resistance, and flexibility, as well as good acid resistance and scratch resistance. be.

[Means for Solving the Problems] The gist of the present invention is that (a) an aliphatic and/or alicyclic urethane (meth)acrylate containing three or more (meth)acryloyl groups in one molecule; , a mixture consisting of component A such that the glass transition temperature of the cured coating film as determined by dynamic viscoelasticity measurement is less than 40°C, and component B such that the cured coating film has a glass transition temperature of 60°C or higher, and whose glass transition temperature is 40°C.
50 to 100 parts by weight of a composition having a temperature of ~100°C; (b) 0 to 100 parts by weight of a radically polymerizable compound containing 3 or more (meth)acryloyl groups in one molecule, no urethane bond, and a molecular weight of 300 or more; 50 parts by weight, and 0.5 parts by weight of (C) radical polymerization initiator per 100 parts by weight of the total of components (a) and (b). It is characterized by comprising a composition (A) consisting of 1 to 3.0 parts by weight, an acrylic copolymer having carboxyl groups and hydroxyl groups (B), and a curing agent (C) selected from amine resins and polyisocyanates. It is a thermosetting composition.

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 glass transition temperature (hereinafter referred to as Tg) of the urethane (meth)acrylate polymer can be determined from the maximum value of the temperature dispersion curve by measuring the dynamic viscoelasticity of the crosslinked cured coating film.

In the present invention, the Tg obtained by mixing component A, which is a urethane (meth)acrylate with a Tg of 409C or less, and component B, which is a urethane (meth)acrylate with a Tg of 60C or more, is 40 to 100C. What becomes a composition (
a). The glass transition temperature of component A or component B is 40
If the temperature is higher than 60°C or lower than 60°C, the appearance will be unsatisfactory. Flexibility is insufficient when component A or component B is used alone.

In addition to this, the glass transition temperature of composition (a) is 40 to
It is necessary to adjust the temperature to a range of 100°C.

If the temperature is below 40°C, solvent resistance, scratch resistance, etc. will decrease, and 1
When the temperature exceeds 00°C, weather resistance decreases. Further, the usage range is 50 to 100 parts by weight, and if it 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''-methylene bis(cyclohexyl) incyanate, methylcyclohexane 2.4 diisocyanate, methylcyclohexane 2.6
-diisocyanate, 1. 3-bis(incyanatomethyl)cyclohegyusan, inphorone diisocyanate,
Diisocyanates such as trimethylhexamethylene diisocyanate, tetramethylene diisocyanate, dimer acid diisocyanate, simple triisocyanates, Piure 3. Examples include polymers thereof, adducts thereof with polyols, and the like. 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, pentaerythritol, and polyol. pentaerythritol, sorbitol,
Examples include alcohols such as mannitol, glycerin, and polyglycerin, polyether polyols, polyester polyols synthesized from polyhydric alcohols and polybasic acids, and polyester polyols such as polycaprolactone polyol.

Examples of hydroxyl group-containing vinyl monomers include 2-hydroxyethyl (meth)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.

Component A, which is an aliphatic and/or alicyclic urethane (meth)acrylate such that the glass transition temperature of the cured coating film is less than 40°C, includes inholonocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and tetramethylene. It can be obtained by reacting vinyl sotho or trimer such as diisocyanate with polyethylene glycol, polypropylene gellicol, polybutylene glycol, polytetramethylene glycol, polycaprolactone diol, etc., and the above-mentioned hydroxyl group-containing vinyl monomer.

Component B, which is an aliphatic and/or alicyclic urethane (meth)acrylate such that the glass transition temperature of the cured coating film is 60° C. or higher, is ethylene diisocyanate, 1.2
-diisocyanatopropane, 1,3-diisocyanatopropane, 4,4-diphenylmethane diisocyanate, hexamethylene diisocyanate, lysine isocyanate, 4I4-monethylenebis(cyclohexyl)incyanate, methylcyclohexane 2,4-diisocyanate, methylcyclohexane Diisocyanates such as 2,6-diisocyanate, 1,3-bis(incyanatomethyl)cyclohexane, inphorone diisocyanate, trimethylhexamethylene diisocyanate, tetramethylene diisocyanate, dimer acid diisocyanate, simple triisocyanates, burets and polymers thereof It can be produced by reacting a diol having 4 or less carbon atoms such as ethylene glycol or propylene glycol with the above-mentioned hydroxyl group-containing vinyl monomer.

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 contains 0 to 50 parts by weight per 100 parts by weight of the total amount of components (8) and (b) in the composition (A) of the present invention. If the amount exceeds 50 parts by weight, the weather resistance will deteriorate, which is not preferred. Specifically, polybasic acids such as phthalic acid and adipic acid, polyhydric alcohols such as ethylene glycol and butanediol, and (meth)
Polyester poly(meth)acrylate obtained by reaction with acrylic acid compound, epoxy poly(meth)acrylate obtained by reaction between epoxy resin and (meth)acrylic acid compound, reaction between polysiloxane and (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 the composition in the present invention (
0.0% per 100 parts by weight of the total amount of components (a) and (b) in A). 1 to 3.0 parts by weight is added, and if it is less than 0.1 part by weight, sufficient coating film hardness cannot be obtained, and if it exceeds 3.0 parts by weight, the stability of the coating material decreases, which is not preferable.

Examples of the polymerization initiator used here include penzoyl oxide, cumene hydroperoxide, di-
Peroxides such as t-butyl hydroperoxide, dicumyl, f-oxide, t-butyl peracetate, t-butyl perbenzoate, t-butyl hydroperoxide, azobisisobutyronitrile, 2,2-azobis( 2-methylbutyronitrile), 1,1-azobis(cyclohexane-1-carbonitrile), 2,2--
Azobis(2,4-dimethylvaleronitrile), 2.2
Examples include azo compounds such as -azobis(2-methylpropane), and 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 (meth)acrylate and ethylene oxide adduct, 2-hydroxyethyl (meth)acrylate and propylene oxide adduct, 2-hydroxyethyl (meth)acrylate and ε-caprolactone adduct, 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, diethylaminoethyl (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 amino resin of 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.

The polyisocyanate compound used as component (C) is a compound having two or more incyanate groups in one molecule, and specifically, di(or tri)incyanate compounds, such as tetra Fat 111i1 incyanates such as methylene diisocyanate, hexamethylene diisocyanate, decamethylene diisocyanate, ethylene diisocyanate, isophorone diisocyanate, lysine diisocyanate, xylylene diisocyanate, methyl xylylene diisocyanate, phenylene diisocyanate, tolylene diisocyanate, 4.
4'-methylenebis(phenylisocyanate), 3,
Aromatic incyanates such as 3'-diisocyanate 1,4-dimethylbenzene, triphenylmethane diisocyanate, and 1-methyl-2,4-diisocyanate cyclohexanone, 4,4-methylenebis(cyclohexyl incyanate), cyclohexane diisocyanate Examples include alicyclic isocyanates such as hexamethylene diisocyanate isocyanurate.

The addition ratio of component (B) and component (C) can be arbitrarily selected depending on the purpose and is not particularly limited, but the weight ratio of (B)/(C) is 10/90 to 9515, Particularly preferred is a range of 60/40 to 90/10.

In addition, the mixing ratio of components (A), (B), and (C) is as follows:
Usually, the weight ratio of A/(B+C) is 9°/10~20/
Used in the 80 range. Further, from the viewpoint of curing speed and coating performance, 80/20 to 50150 is preferable. -90 for boat fishing
When it is larger than /10, the base layer tends to return to the clear layer, and when 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-cissing 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.

Measuring method of glass transition temperature> A coating film with a dry film thickness of Zooμm baked at 140°C for 40 minutes was measured using a dynamic viscoelasticity measuring instrument (RH made by Toyo Baldwin Co., Ltd.).
The glass transition temperature was determined by reading the temperature at the maximum value of the dynamic viscoelastic temperature dispersion curve using an EOVIBRON DDV-II-EP.

Production example of polyurethane (meth)acrylate (a)-1> 1 mol of hexamethylene diinocyanate Beauleft and 0.002 mol of dibutyltin dilaurate were added to a reaction vessel, and after heating to 70°C, polybutylene glycol 1 mol was added dropwise over 1 hour, then reacted at the same temperature for 3 hours, and then pentaerythritol triacrylate 3
mol was added dropwise over 1 hour, and after the addition, the reaction was further carried out for 5 hours.
Urethane (meth)acrylate (a)-1 having a glass transition temperature of 117°C was obtained.

Production example of urethane (meth)acrylate (a)-2〉 Inphorone diisocyanate burette was used instead of the methylene diisocyanate puret, and 0.00 mol of dibutyltin dilaurate was used instead of 0.002 mol.
Production example except using 1 mol and 2-hydroxypropyl acrylate instead of polybutylene glycol -
In the same manner as in Example 1, urethane (meth)acrylate (a)-2 having a glass transition temperature of 94°C was obtained.

Production example of urethane (meth)acrylate (a)-3> 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, then reacted at the same temperature for 3 hours, and then added 2-hydroxypropyl methacrylate 3.
mol was added dropwise over 1 hour, and after the addition, the reaction was further carried out for 5 hours.
Urethane (meth)acrylate (a)-3 having a glass transition temperature of 62°C was obtained.

Production example of urethane (meth)acrylate (a)-4> 0.001 mol of dibutyltin dilaurate instead of 0.002 mol, and 3 mol of butylene glycol instead of 1 mol of polybutylene glycol-17=col, and 2 instead of pentaerythritol triacrylate
-Urethane with a glass transition temperature of 56°C (
Meth)acrylate (a)-4 was obtained.

Production example of urethane (meth)acrylate (a)-5> Production example = except that 3 moles of polyethylene glycol was used instead of 1 mole of polybutylene glycol, and 2-hydroxypropyl methacrylate was used instead of 2-hydroxypropyl acrylate. In the same manner as in 2, urethane (meth)acrylate (a) with a glass transition temperature of 49°C -
Got 5.

<Production example of urethane (meth)acrylate (a)-6> Hexamethylene diisocyanate trimer instead of hexamethylene diisocyanate biuret, 0.001 mole of dibutyltin dilaurate instead of 0.002 mole
Polyurethane (meth) with a glass transition temperature of 27°C was prepared in the same manner as in Production Example 1, except that 3 moles of polybutylene glycol were used instead of 1 mole, and 2-hydroxyethyl acrylate was used instead of pentaerythritol triacrylate. ) Acrylate (a)-6 was obtained.

Production example of urethane (meth)acrylate (a)-7> Hexamethylene diisocyanate instead of hexamethylene diisocyanate trimer, 2 moles of polybutylene glycol instead of 3 moles, and 3 moles of 2-hydroxyethyl acrylate. Urethane (meth)acrylate (a)-7 having a glass transition temperature of 38° C. was obtained in the same manner as Production Example-6 except that 2 mol was used instead.

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. Then, after increasing the temperature to 120° C. with stirring, the following monomer mixture 10
0 parts by weight, 2 parts by weight of azobisisobutyronitrile and t-
A mixture of 2 parts by weight of butylberoxyisopropyl carbonate was added dropwise over 3 hours. Next, while stirring the mixture, 0.1 part by weight of azobisisobutyronitrile was added four times at 30 minute intervals. Furthermore, after heating and stirring at 120°C for 2 hours to increase the reaction rate, n-butyl acetate 1
3.3 parts by weight was added, the reaction was terminated, and an acrylic copolymer (B) was obtained.

(Monomer mixture) Styrene 26 parts by weight Methacrylic acid 2 parts by weight n-butyl methacrylate 20 parts by weight t-butyl methacrylate 5 parts by weight 2-ethylhexyl methacrylate 29 parts by weight 2-hydroxyethyl methacrylate 18 parts by weight (Component (B) and (C) ) Example of manufacturing a mixture of components> Components (B) and (C) were mixed at the blending ratio shown below to obtain mixtures (1) and (2).

Unit double placement part a): Melamine resin manufactured by Mitsui Toatsu Chemical Co., Ltd. b) Polyisocyanate manufactured by Nippon Polyurethane Co., Ltd. (Examples 1 to 7, Comparative Examples 1 to 8) After degreasing the steel plate, Table - Each of the compositions shown in Table 1 was coated on the above steel plate to a dry film thickness of 35 μm, left at room temperature for 10 minutes, and then 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, flexibility, and better appearance than the comparative examples.
Both acid resistance and scratch resistance were excellent.

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

Claims (1)

[Scope of Claims] (a) Glass transition of a cured coating film determined by dynamic viscoelasticity measurement of an aliphatic and/or alicyclic urethane (meth)acrylate containing three or more (meth)acryloyl groups in one molecule. A mixture consisting of component A that has a temperature of less than 40°C and component B that has a temperature of 60°C or higher, and has a glass transition temperature of 40°C.
50 to 100 parts by weight of a composition having a temperature of ~100°C, (b) a radically polymerizable compound containing three or more (meth)acryloyl groups in one molecule, containing no urethane bonds, and having a molecular weight of 300 sides. ~50 parts by weight, and (c) a composition (A) consisting of 0.1 to 3.0 parts by weight of a radical polymerization initiator based on 100 parts by weight of the total amount of components (a) and (b), A thermosetting composition comprising an acrylic copolymer (B) having a carboxyl group and a hydroxyl group, and a curing agent (C) selected from amino resins and polyisocyanates.