JPH02199110A - Resin composition for gel coat - Google Patents

Abstract

PURPOSE:To enable to form a resin composition for gel coat excellent in weathering resistance, scratch resistance, abrasion resistance, boiling resistance and moldability by mixing a specified acryl urethane resin prepared by using a cyclohexane ring-containing glycol with a reactive diluent. CONSTITUTION:This resin composition for gel coat comprises 100 pts.wt. acryl urethane resin (A) having ethylenically unsaturated groups on both ends, obtained by reacting 1g equivalent of a glycol component (1) containing 1-100wt.% cyclohexane skeleton-containing compound with 1.5-2.5g equivalents of a nonyellowing or hardly yellowing diisocyanate compound (2) and 1.5-2.5g equivalents of an ethylenically unsaturated monomer (3) having at least one hydroxyl in the molecule, and 1-100 pts.wt. in total of a reactive diluent comprising an ethylenically unsaturated monomer (B) and/or a crosslinkable monomer (C) having at least two double bonds and/or a crosslinkable oligomer (D).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a resin composition for gel coat that has excellent weather resistance, heat resistance, and boiling resistance.

[Conventional technology]

Molded products using unsaturated polyester resins are often coated with a gel coat for the purpose of improving their appearance and performance such as scratch resistance and crack resistance.

Examples of molded products to which gel coating is applied include FRP and cast products, such as residential equipment such as bathtubs and washstands, and outdoor equipment such as benches and boats.

As for the performance of the resin, as mentioned above, we place emphasis on the appearance, transparency that gives a deep sense of transparency, gloss, weather resistance, scratch resistance that makes small scratches less noticeable, crack resistance, Furthermore, water resistance, heat resistance, and boiling resistance are required for use in water surroundings such as bathtubs.

The resins conventionally used as gel coat resins are unsaturated polyester, unsaturated epoxy ester, etc., and in Japanese Patent Publication No. 1988-1988, unsaturated epoxy resin and unsaturated polyester resin were proposed as a method for improving scratch resistance. Blends of melamine resins have been reported in JP-A-57-3992.

Generally, the amount of gel coat resin used is very small, only a few percent of the entire molded product, so it is possible to use expensive special resins. , improvements in wear resistance have been reported.

However, in these gel coat resin compositions, the basic resin skeleton is unsaturated polyester resin, resins with poor weather resistance such as melamine are blended, and in most cases, styrene is the basic diluent monomer. As a result, the weather resistance as a gel coat is not good at present.

[Problem to be solved by the invention]

In addition to the above-mentioned Zelkova, conventional gel coat resins are usually based on unsaturated polyester resins, with styrene added as a diluent.

Furthermore, in order to improve toughness and hot water resistance, which are drawbacks when using unsaturated polyester resin, aromatic compounds were introduced into the resin, which tended to reduce its crack resistance and weather resistance. Ta.

Therefore, the present invention solves the above problems and improves weather resistance and
An object of the present invention is to provide a resin composition for gel coat that has excellent scratch resistance, abrasion resistance, boiling resistance, and moldability.

[Means to solve the problem]

As a result of intensive studies to solve the above problems, the present inventors have found that a urethane prepolymer with isocyanate groups at both terminals obtained from a glycol component having a cyclohexane ring and a non-yellowing or non-yellowing type diisocyanate, The inventors have found that the above-mentioned problems can be solved by using a resin composition consisting of an acrylic urethane resin modified with an ethylenically unsaturated monomer containing a hydroxyl group and a reactive diluent, and have completed the present invention.

That is, the present invention provides an acrylic urethane resin obtained by acrylic modification of a urethane prepolymer having isocyanate groups at both ends obtained by reacting a glycol component having a cyclohexane ring with a non-yellowing or non-yellowing type diisocyanate, and a reactive diluent. This is a gel coat resin composition consisting of a gel coat agent.

As the glycol component used in the present invention, compounds having a skeleton represented by the following general formula (1), (wherein R6
, R2 is an alkyl group which may be the same or different, R3
, R4, R2, and R6 are H, which may be the same or different.
A cyclohexane ring-containing polyester oligomer or polymer obtained by reacting a compound having a skeleton represented by the general formula (I) with a carboxylic acid or its anhydride; (Hereinafter, it will be abbreviated as cyclohexane ring-containing polyester oligomer.

) can be used.

Examples of the compound having the above-mentioned skeleton include cyclohexane dimetatool, hydrogenated bimataphenol A, cyclohexanediol, cyclohexanetriol, and the like.

These compounds may be used alone or as a mixture. Further, it may be used in combination with the above-mentioned glycol component that does not have a skeleton.

Examples of the glycol component without a cyclohexane skeleton include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, 1,3-phthylene glycol, 2,3-butylene glycol, 14-butylene glycol, neo Examples include pentyl glycol, hexylene glycol, and octylene glycol.

The compound having a cyclohexane ring, which is the glycol component, has no double bond in the molecule due to its skeleton, so it has the advantage of being excellent in weather resistance. It also provides a resin that is generally hard and has excellent chemical resistance and water resistance.

When using a linear glycol that does not have a cyclohexane ring, there is a risk that the strength and hardness of the final molded product may not be obtained. Therefore, as a glycol component, a compound that has a cyclohexane ring is used, assuming that the entire glycol component is 100. It is desirable to contain 50% or more.

When using the above-mentioned cyclohexane ring-containing polyester oligomer or polymer as the glycol component, its performance is determined by the acid component contained in the polyester oligomer or polymer. A material that does not adversely affect weather resistance is desirable.

Examples of the carboxylic acid or its acid anhydride used in the synthesis of the cyclohexane ring-containing polyester oligomer or polymer include succinic acid, adipic acid, cepacic acid, azelaic acid, hexahydrophthalic anhydride, phthalic anhydride, fumaric acid, Examples include itaconic acid and citraconic acid.

When the above polyester oligomer or polymer is used as a glycol component, its acid value is preferably O, but
At least 5 or less.

In addition, when polyester polyol is used as a component other than cyclohexane skeleton-containing glycol, it is important to note that the properties of the component will vary greatly depending on the number of methylene groups forming the skeleton, the presence or absence of ether bonds, the number of hydroxyl groups contained, etc. must be taken into consideration.

Examples of the polyester polyols include glycerin, trimethylolpropane, 1.2.6-hexanetriol, trimethylolethane, pentaerythritol, polyethylene glycol, polypropylene glycol, polyethylenepropylene glycol, poly(oxytetramethylene) glycol, and the like. It will be done.

As the diisocyanate used in the present invention, non-yellowing or hardly yellowing types are used, such as propylene diisocyanate, butylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, 2,4.4(2,4,4)- Trimethylhexamethylene diisocyanate, lysine diisocyanate, cyclopentane diisocyanate, 1,4-cyclohexane diisocyanate, α-incyanatoethylcyclohexene-3-isocyanate, bis(isocyanatomethyl)-cyclohexane, hydrated toluylene diisocyanate, hydrogenated 414゛-diphenylmethane Diisocyanate, inphorone diisocyanate, bis(3-methyl, 4-isocyanatecyclohexyl)methane, xylylene diisocyanate, α-isocyanate ethylbenzene-3-isocyanate, diethyl fumarate diisocyanate, and the like.

Examples of the ethylenically unsaturated monomer having at least one hydroxyl group in the molecule used in the present invention include 2-hydroxyethyl methacrylate and 2-hydroxyethyl acrylate.
Examples include hydroxyethyl, 2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, and 3-hydroxypropyl acrylate.

The above reaction between the glycol component and the diisocyanate is carried out by adding 1.5 to 2.5 g equivalent, preferably 1.9 to 2 g equivalent, of diisocyanate to 1 g equivalent of the glycol component, and adding 1.5 to 2.5 g equivalent, preferably 1.9 to 2 g equivalent, of the diisocyanate at a reaction temperature of 30 to 60°C. React for ~5 hours, then add 1.5 to 2.5 g equivalent, preferably 1.9 to 2 g equivalent, of an ethylenically unsaturated monomer having at least one hydroxyl group in the molecule, and heat to 50 to 70°C. Te3~
Reaction is carried out for 5 hours, and the reaction is continued until NC0% - 〇.If NC0%>0, add alcohol and reduce
It is more advantageous to set it to %-0.

Note that a reaction catalyst may be added if necessary.

The obtained urethane acrylate usually has a considerably high viscosity and cannot be used as a gel coat as it is, so dilution is required.

Among the reactive diluents used here, the amount of ethylenically unsaturated monomer used is 1/1 of the obtained acrylic urethane resin.
00 parts by weight, 1 to 99 parts by weight, preferably 5 to 5 parts by weight
0 parts by weight, more preferably 10 to 30 parts by weight.

However, among the ethylenically unsaturated monomers used, compounds such as aromatic amines that can significantly reduce weather resistance are not used unless there is a particular reason, and even if used, it is preferably 5 parts by weight or less. is 3 parts by weight or less.

Further, the amount of the crosslinkable unsaturated monomer and crosslinkable oligomer having at least two or more double bonds in the molecule is 1 to 99 parts by weight.

The total amount of these reactive diluents used is adjusted to 1 to 100 parts by weight based on 100 parts by weight of the acrylic urethane resin.

When the amount of reactive diluent is less than 1 part by weight, the resin viscosity is too high, making coating work difficult, and even if coating is possible, it is impossible to adjust the film thickness or smooth the surface. Furthermore, if the amount of the reactive diluent exceeds 100 parts by weight, the effects thereof are significant and the desired gel coat layer cannot be obtained.

Among the reactive diluents used in the present invention, examples of ethylenically unsaturated monomers include methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, Propyl methacrylate, isopropyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-methacrylate
Hydroxypropyl, methacrylic acid and its esters such as methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, propyl acrylate, isopropyl acrylate, 2-ethylhexyl acrylate, uryl acrylate, 2-hydroxy acrylate Acrylic acid and its esters such as ethyl, acrylic acid, etc.
Examples include vinyl acetate, acrylate, acrylamide, methacrylamide, styrene, α-methylstyrene, and the like.

In addition, examples of ethylenically unsaturated monomers with relatively little odor include methoxydiethylene glycol methacrylate,
Methoxytetraethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, β-methacrylooxyethyl hydrogen phthalate, β-methacrylooxyethyl hydrogen succinate, nonylphenoxyethyl methacrylate, phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, phenoxypolyethylene glycol acrylate, methoxytri Ethylene glycol acrylate, methoxypolyethylene glycol acrylate, β-acryloyloxyethyl hydrogen phthalate, β-acryloyloxypropyl hydrogen phthalate, β
-acryloyloxyethyl hydrogen succinate, butoxydiethylene glycol acrylate, nonylphenoxyethyl acrylate, and the like.

In addition, examples of crosslinkable unsaturated monomers include ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate,
．． 3-butylene glycol dimethacrylate, 1.3-
Propylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, polypropylene glycol dimethacrylate, 1,6-hexanethiol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, trimethylolethane triacrylate Acrylate, Trimethylolethane trimethacrylate, Tetramethylolethane trimethacrylate, Tetramethylolmethane triacrylate, Tetramethylolmethane trimethacrylate, Tetramethylolmethanetetraacrylate, 2.2-bis[4-
(Methacryloxyethoxy)phenyl]propane, pentaerythritol triacrylate, dipentaerythritol hexaacrylate, and the like.

Examples of crosslinkable oligomers include oligoester acrylates, oligoester methacrylates, urethane acrylate oligomers, urethane methacrylate oligomers, acrylic-modified epoxy oligomers, epoxy-modified acrylic urethane oligomers, acrylate oligomers, methacrylate oligomers, and the like.

As described above, the gel coat resin composition obtained in the present invention has an acrylic urethane resin, an ethylenically unsaturated monomer, and a crosslinkable unsaturated monomer, instead of the conventional combination of an unsaturated polyester resin and styrene. The combination of polyester and crosslinkable oligomer provides molded products with excellent weather resistance, scratch resistance, and strength.

〔Example〕

EXAMPLES Hereinafter, in order to explain the present invention more specifically, Examples and Comparative Examples will be given and explained, but the present invention is not limited to these Examples.

Examples 1 to 4 144.21 g of cyclohexane dimetatool and 444.3 g of isophorone diisocyanate were added to a flask equipped with a thermometer and a stirrer, and a reaction was carried out at 50° C. for 3 hours.

Furthermore, 260 g of hydroxyethyl methacrylate was added and the reaction was carried out at 50°C to 70°C for 3 hours.
After confirming that the votes are 0, obtain acrylic urethane... fat (1).

For the obtained (1), each gel coat resin composition was obtained by formulating C as shown in Table 1.

Examples 5 to 7 230 g of cyclohexane dimetatool, 30 g of propylene glycol, and 290 g of adipic acid were added to a flask equipped with a thermometer, a stirrer, and a dehydrator, and the reaction was carried out at 200°C, resulting in a polyester oligomer of 500 g.
380 g of hexamethylene diisocyanate) was added to the reaction mixture, and the reaction was carried out at 40 to 50°C for 3 hours.
The reaction is carried out at 70°C for 3 hours, and after confirming NC0%-〇, acrylic urethane resin (II) is obtained.

With respect to the obtained (It), according to the camphor mixture shown in Table 1,
Each gel coat resin composition is obtained.

Examples 8 to 10 378 g of hydrogenated bisphenol A and 4 neopentyl glycol were placed in a flask equipped with a thermometer, a stirrer, and a dehydrator.
2g of dicyclohexyldimethylmethane p,p'-diisocyanate was added to 500g of the obtained polyester resin by adding 2g of maleic anhydride, and 154g of hexahydrophthalic anhydride, and carrying out the reaction at 200 to 210°C.
Add 60 g of hydroxyethyl methacrylate for 5 hours at 40-50°C, then add 180 g of hydroxyethyl methacrylate and react for 3 hours at 70°C. Get [[).

The obtained (Itl) was blended as shown in Table 1 to obtain each resin composition for gel coat.

Comparative Examples 1 to 3 152 g of propylene glycol and 444.3 g of isophorone diisocyanate were placed in a flask equipped with a thermometer and a stirrer.
g and reacted at 50°C for 3 hours, further added 260g of hydroxyethyl methacrylate, and reacted at 50°C.
The reaction was carried out at 70°C for 3 hours, and after confirming NC0%-〇, an acrylic urethane resin (IV) was obtained.

With respect to the obtained (IV), by the formulation shown in Table 1,
Each gel coat resin composition is obtained.

Comparative Examples 4 to 6 Gel coat resin compositions based on gel coat resin R-2150 manufactured by Mitsui Toatsu Chemical.

The evaluation results of Examples 1 to 10 and Comparative Examples 1 to 6 are shown in Table 1.

Evaluation Results (Moldability) Crank: ◎... Not produced at all ○... Produced on a part of the edge △... Surface ×... Gloss produced on the entire surface: O... Very good O...Good Δ...Partially lack luster ×...No gloss (weather resistance) O...5M0N ΔB<30 at 500 hours...
・l 4kuΔE<8Δ...
9〈ΔE〉12×... #13〈ΔE [Effect of the invention] The resin composition for gel coat of the present invention is based on an acrylic urethane resin, and contains an ethylenically unsaturated monomer with good weather resistance and a crosslinkable unsaturated monomer. It is useful as a high-grade gel coat resin that can replace conventional unsaturated ester resins by diluting it with saturated monomers and crosslinkable oligomers, and as a resin that gives gloss, depth, and weather resistance to molded products in various applications.

Patent applicant: Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Claims] 1. (A) (1) A compound having a cyclohexane skeleton, 1 to 10
(2) 1.5 to 2.5 g equivalent of non-yellowing or non-yellowing type diisocyanate compound and (3) ethylenic monomer having at least one hydroxyl group in the molecule, per 1 g equivalent of glycol component containing 0% by weight. (B) As a reactive diluent, 100 parts by weight of an acrylic urethane resin having ethylenically unsaturated groups at both ends obtained by reacting 1.5 to 2.5 g equivalent of a saturated monomer, unsaturated monomer and/or (C) crosslinkable unsaturated monomer having at least two or more double bonds in the molecule and/or (D) crosslinkable oligomer, (B) to (D ) in a total amount of 1 to 100 parts by weight. 2. A compound having a cyclohexane skeleton is a saturated or unsaturated compound having a hydroxyl group at both ends, which is obtained by reacting a compound having a cyclohexane skeleton represented by the following general formula (I) with a saturated or unsaturated carboxylic acid or its anhydride. The gel coat resin composition according to claim 1, which is an unsaturated polyester oligomer. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (In the formula, R_1 and R_2 are alkyl groups that may be the same or different, and R_3, R_4, R_5, and R_6 are R and C_1 that may be the same or different. ~ C_1_0 represents an alkyl group or halogen.) 3. Claim 2 wherein the saturated or unsaturated polyester oligomer having hydroxyl groups at both ends has a molecular weight of 1000 or less.
The gel coat resin composition described above. 4. The resin composition for gel coat according to claim 1, 2 or 3, wherein the glycol components other than the compound having a cyclohexane skeleton are polyester polyols. 5. The resin composition for gel coat according to claim 1, wherein the compound having a cyclohexane skeleton is a compound having a cyclohexane skeleton represented by the general formula (I) according to claim 2. 6. The resin composition for gel coat according to claim 1, 2, 3 or 5, wherein the glycol components other than the compound having a cyclohexane skeleton are glycol compounds.