JPH04170415A - Curable resin composition - Google Patents

Abstract

PURPOSE:To obtain the title compsn. giving a coating film excellent in adhesion to a molded surface having minute pores and unevenness by incorporating a urethane (meth)acrylate obtd. by reacting a specific diisocyanate, a specific diol compd., and a (meth)acrylate in a specified ratio into the compsn. CONSTITUTION:The title compsn. contains a urethane (meth)acrylate obtd. by reacting a diisocyanate having a cyclohexane ring in the molecule (e.g. isophorone diisocyanate), a diol compd. of formula I [wherein m and n are each 0-10; and R1 is 1-6C divalent alkyl, a group of formula II (wherein R2 and R3 are each 2-10C divalent alkyl), or a group of formula III (wherein R4 is R2)], and a hydroxylated (meth)acrylate (e.g. 2-hydroxyethyl acrylate) in such a molar ratios among the molar number of NCO groups in the diisocyanate (X), that of OH group in the diol compd. (Y), and that of OH group in the (meth)acrylate (Z) as to satisfy X/Y=5/4-16/5 and Z>=(X-Y).

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a curable resin composition with excellent radical polymerizability that is suitable for use in paints, etc. More specifically, it relates to a coating film obtained by polymerization. However, the present invention relates to a curable resin composition that has excellent adhesion to molded products and molded products having pores and fine irregularities on the surface.

[Prior art] Molded and molded products that have pores and fine irregularities on their surfaces, such as FRP molded products and aluminum tie-cast molded products, are often painted on the surface with the intention of improving their appearance. However, pores on the surface can cause foaming and poor adhesion of the coating, and it is desired to apply a coating that does not have these problems.

Conventional paints include, for example, a type in which a high molecular weight polymer is diluted with a large amount of solvent.
Even if the adhesion is good, because a large amount of solvent is used, many air bubbles are generated in the paint film when it is cured.
I can't get something that looks good.

Furthermore, as a paint that can be used without a solvent, there is an active energy ray-curable paint. Among such paints, those currently in general use include those whose main component is polyester urethane polyacrylate using aliphatic polyester diol, which is disclosed in JP-A-60-235822. However, when these products are applied to molded products or molded products with pores on the surface, bubbles are likely to occur in the coating film, and even if they do not occur, the adhesion is poor, so they are not satisfactory. has not been obtained.

[Problems to be Solved by the Invention] The present invention has been developed in view of the above circumstances, and its purpose is to prevent coating when applied to molded products, molded products, etc. that have pores or minute irregularities on the surface. without forming bubbles etc. in the film.
Moreover, it is an object of the present invention to provide a curable resin composition that has good adhesion to the surface to which it is applied.

[Means for Solving the Problem] As a result of various studies to achieve the above object, the present inventors found that by using urethane acrylate with a specific structure, the paint film does not foam and has good adhesion. The present inventors have discovered that a curable resin composition that forms a coating film with excellent properties can be obtained, and have completed the present invention.

That is, the present invention provides (A) a diisocyanate having a cyclohexane ring in its molecular structure, (B) a diolized metal compound represented by the following formula (1) (where m and n are integers from 0 to 10, and R8 is the following: Any one of (1), (2>, (3))
Substituent of.

(1) A divalent alkyl group having 1 to 6 carbon atoms, (2) -820CR3C-, where R2 and Rs are each a divalent alkyl group having 2 to 10 carbon atoms, (3>-R4- C-1 where R4 has 2 to 10 carbon atoms
(C) Hydroxyl group-containing acrylate or hydroxyl group-containing methacrylate, each component shown in (A), (B) and (C) above, (A)
) is the number of moles of isocyanate groups present in the component shown in (
The number of moles of hydroxyl groups in the components shown in X) and (B) (
The reaction is carried out in a range where the relationship between Y) and the number of moles of hydroxyl groups (Z) in the component shown in (C) is X/Y = 5/4 to 1615 and Z≧(X-Y). This is a curable resin composition containing urethane acrylate or urethane methacrylate.

The present invention will be explained in detail below.

The curable resin composition of the present invention, urethane acrylate or urethane methacrylate, contains diisocyanate, diol, and hydroxyl group-containing acrylate or methacrylate (hereinafter, acrylate or methacrylate is referred to as (meth)acrylate). It is obtained by reacting.

There are various known diisocyanates that have a cyclohexane ring in their molecular structure, and specific examples include bis(4-isocyanatocyclohexyl)methane, methylcyclohexane 2,4-diisocyanate, and methylcyclohexane. Examples include 2,6-diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, and isophorone diisocyanate.

Specific examples of the diol compound represented by the general formula (1) used in the present invention include 2,2-bis(4-hydroxycyclohexyl)propane and polyether diols and polyester diols obtained by modifying this. be able to.

As the polyether diol, those synthesized by polymerizing 2,2-bis(4-hydroxycyclohexyl)propane with aldehyde, alkylene oxide, or glycol by a known method can be used, such as formaldehyde, Examples include polyether diols obtained by addition polymerizing ethylene oxide, propylene oxide, tetramethylene oxide, evichlorbitrin, etc. under appropriate conditions.

In addition, as the polyester diol, saturated polycarboxylic acids and/or their acid anhydrides and 2,2-bis(
4-bitroxycyclohexyl)propane in an excess amount, and 2.2
A polyester diol obtained by ring-opening polymerization of -bis(4-hydroxycyclohexyl)propane and a hydroxycarboxylic acid and/or a lactone that is an intramolecular ester thereof can be used.

Examples of saturated polycarboxylic acids include oxalic acid, malonic acid, succinic acid, methylsuccinic acid, 2,3-dimethylsuccinic acid, hexylsuccinic acid, glutaric acid, 2,2-dimethylglutaric acid, 3,3-dimethyl Glutaric acid, 3.
3-diethylcurtaric acid, adipic acid, pimelic acid, schelic acid, acelaic acid, sebacic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1.4-cyclohexanedicarboxylic acid, 1,1
-cyclobutanedicarboxylic acid and halo and alkyl derivatives of the above acids.

Hydroxycarboxylic acids include lactic acid, glycolic acid,
Examples include α-hydroxylactic acid, β-hydroxylactic acid, α-hydroxyisolactic acid, hydroxystearic acid, resilic acid, β-hydroxypivalic acid, and γ-hydroxyvaleric acid.

Specific examples of hydroxyl group-containing (meth)acrylates include 2- and droxyethyl (meth)acrylate, 2
-Hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 3-chloro-2-
Hydroxypropyl (meth)acrylate, 3-bromo-2-hydroxypropyl (meth)acrylate, 2-
Examples include chloro-1-(hydroxymethyl)ethyl (meth)acrylate, 2-bromo-1-(hydroxymethyl)ethyl (meth)acrylate, and the like.

In the present invention, the components (A), (B), and (C) constituting the urethane (meth)acrylate are (A
) The number of moles of isocyanate groups (X) present in component (B) and the number of moles of hydroxyl groups (Y) in component (B) are X/
It is necessary that Y=5/4 to 1615 and that the number of moles (Z) of hydroxyl groups present in component (C) is 2≧(xy). If X/Y is smaller than 5/4, it is not preferable in terms of curability. Also, X/Y is 1615
If it is larger, it is not preferable in terms of curability and toughness of the cured coating film.

In the present invention, urethane (meth)acrylate can be obtained by simultaneously mixing and reacting a diisocyanate compound, a diol compound, and a hydroxyl group-containing (meth)acrylate. Alternatively, a diol compound and a diisocyanate compound are reacted to form a urethane isocyanate intermediate containing one or more incyanate groups per molecule, and then this intermediate and a hydroxyl group-containing (meth) A method of reacting a diisocyanate compound with a hydroxyl group-containing (meth)acrylate,
Examples include a method in which a urethane acrylate intermediate containing one or more incyanate groups per molecule is formed, and then this intermediate is reacted with a diol compound.

In order to adjust the viscosity to a desired level, the resin composition of the present invention contains diluents such as organic solvents and radically polymerizable vinyl monomers, and thickeners such as acrylic polymers and m-line polymers. It's okay.

Examples of organic solvents include ketone compounds such as acetone, methyl ethyl ketone, and cyclohexanone; ester compounds such as methyl acetate, ethyl acetate, butyl acetate, ethyl lactate, and methoxyethyl acetate; and ether compounds such as diethyl ether, ethylene glycol dimethyl ether, and dioxane. Compounds: Aromatic compounds such as toluene, xylene, etc. #I: Aliphatic compounds such as bentane, hexane, etc. Halogenated hydrocarbons such as methylene chloride, chlorohenzene, chloroform, etc. can be used. Examples of radically polymerizable vinyl monomers include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, 2- Ethylhexyl (meth)
Acrylate, n-nonyl (meth)acrylate, 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, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, (meth)acrylic acid, (meth)
(meth)acrylate monomers such as acryloylmorphosone, and N-vinyl-2-pyrrolidone, N-vinylimidazole, N~ruvinylcaprolactam styrene, α
-Methylstyrene, vinyltoluene, allyl acetate, vinyl acetate, vinyl propionate, vinyl benzoate, etc. can be used.

Various known acrylic polymers can be used, including (meth)acrylic monomers such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and butyl (meth)acrylate; Examples include homopolymers and copolymers such as vinyl-based polymers such as styrene, vinyltoluene, and vinyl acetate.

Various known cellulose polymers can be used, such as nitrocellulose, cellulose acetate, cellulose acetate butyrate, and the like.

Further, the resin composition of the present invention may contain a polyfunctional (meth)acrylate in order to improve performance such as curing speed and surface hardness.

Specific examples of polyfunctional (meth)acrylates include trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, triallyl cyanurate, triallyl isocyanurate, triallyl formal, 1,:], 5- triacryloylhexahydro-3-triazine, polybrobylene glycol di(meth)acrylate, polyethylene glycol di(
Examples include meta)acrylate.

Additionally, additives such as lubricants, abrasives, rust preventives, and antistatic agents may be added to the resin composition of the present invention.

The curable resin composition according to the present invention produced as described above is applied to, for example, an FRP molded product and then cured.

Methods used for curing the resin composition according to the present invention include a method of irradiating active energy rays, a method using thermal polymerization, etc. 7. Methods used for curing the resin composition according to the present invention As active energy rays,
Examples include ultraviolet rays, electron beams, and gamma rays.

When ultraviolet rays are used as the active energy beam, it is usually preferable to include a photocatalytic compound consisting of one or more of a photopolymerization initiator, a photosensitizer, a photoaccelerator, etc. in the composition.

As the photocatalytic compound, any known compound can be used.

Specific examples of the photopolymerization initiator include benzoin monomethyl ether, henzoin isopropylether, benzophenone, hensyl dimethyl ketal, 2,2-jethoxyacetophenone, and 1-hydroxycyclohexylphenyl ketone. .

Specific examples of the photosensitizer include 2-chlorothioxanthone, 2,4-diethylthioxanthone, and 2,4-diisopropylthioxanthone.

Specific examples of photoaccelerators include ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, and p-dimethylaminobenzoate.
2-n-butoxyethyl -dimethylaminobenzoate, 2-dimethylaminoethyl benzoate, and the like.

In order to cure the resin composition of the present invention by thermal polymerization, it is preferable to include a thermally decomposable polymerization catalyst.

As the thermally decomposable polymerization catalyst, any known catalyst can be used, and specific examples thereof include azo compounds such as azobisisobutyronitrile, hendiyl peroxide, and carbonyl peroxide. Examples include peroxides such as -butyl, dicumyl peroxide, t-butyl perbenzoate, methyl ethyl ketone peroxide, and cyclohexanone peroxide.

The amounts of each of the above catalysts and the like may also be within the ranges normally incorporated.

[Example] In the examples, parts indicate parts by weight.

[Synthesis Examples 1 to 2, Comparative Synthesis Examples 1 to 3] Add (A) to (C) to component (A) and solvent in the amounts shown in Table 1.
Dibutyltin dilaurate was added in an amount of 0.02 parts per 100 parts of the total amount of ingredients, and while keeping it at 40 ° C. Table 1
After dropping component (B) in the amount shown in Table 1 and reacting for a sufficient time, add 0.1 part per 100 parts of the total amount of components (A) to (C) to component (C) in the amount shown in Table 1. A certain amount of dissolved pytroquinone was added dropwise and the mixture was left for a sufficient period of 75 minutes.
After heating and stirring at ℃, urethane acrylate (UA-1,
2,5-7) were obtained.

[Synthesis Examples 3 to 4, Comparative Synthesis Examples 4 to 5] Components (A) to (C) were added to component (A) and solvent in the amounts shown in Table 1.
Add dibutyltin dilaurate in an amount of 0.02 parts per 100 parts of the total amount of ingredients, and while keeping it at 40 ° C. Table 1
(A) to (C) to the amounts of components (B) and (C) shown in
) Sum of ingredients! A solution of pytroquinone in an amount of 0.1 part per 100 parts was added dropwise, and the mixture was heated and stirred at 75°C for a sufficient period of time.
A-3, 4, 8, 9) were obtained.

[Examples 1 to 4, Comparative Examples 1 to 5] Each component with the composition shown in Table 2 was weighed into a beaker, mixed uniformly, and the resulting paint was coated on a white PVC film attached to an iron plate using a bar coater #. 40, dry the solvent at room temperature, and apply ultraviolet rays from a high-pressure mercury lamp (1 lamp) of 80 W/cm at a conhair speed of g 10 from a height of 20 cm.
It was irradiated for 7 minutes.

This sample was subjected to a substrate test according to the test method of JIS K-5400. The number of stitches remaining after a peel test with tape is shown. The results obtained are shown in Table 2. □ [Examples 5 to 8, Comparative Examples 6 to 10] Weigh each component in a beaker with the composition shown in Table 2, mix it uniformly, and apply the resulting paint onto a white PVC film attached to an iron plate using a bar coater. Coated using #40 and heated at 150℃
and cured for 3 minutes.

This sample was subjected to a substrate test according to the JIS -5400 test method. The number of stitches remaining after a peel test with tape is shown. The results obtained are shown in Table 3.

[Effects of the Invention] Since the present invention was constructed as described above, the adhesion of the coating films produced thereby was good as shown in Examples 1 to 4. Moreover, no air bubbles were observed in the coating film formed above, and the composition of the present invention forms a good painted surface.

Patent applicant: Mitsubishi Rayon Co., Ltd.

Claims (1)

[Claims] (A) A diisocyanate having a cyclohexane ring in its molecular structure; (B) A diol compound represented by the following general formula (I) ▲There are numerical formulas, chemical formulas, tables, etc.▼...(I) ( However, m and n are integers from 0 to 10, and R_1 is any one of the substituents shown in (1), (2), and (3) below. (1) A divalent group having 1 to 6 carbon atoms. Alkyl group, (2)▲There are mathematical formulas, chemical formulas, tables, etc.▼, where R_
2, R_3 is a divalent alkyl group with 2 to 10 carbon atoms, (3) ▲There are numerical formulas, chemical formulas, tables, etc.▼, where R_
4 is a divalent alkyl group having 2 to 10 carbon atoms), (C) hydroxyl group-containing acrylate or hydroxyl group-containing methacrylate, each component shown in (A), (B) and (C) above, ( A
) is the number of moles of isocyanate groups present in the component shown in (
The number of moles of hydroxyl groups in the components shown in X) and (B) (
The reaction occurs in the range where the relationship between Y) and the number of moles of hydroxyl groups (Z) in the component shown in (C) is X/Y = 5/4 to 16/5 and Z≧(X-Y). A curable resin composition containing urethane acrylate or urethane methacrylate.