JPH083303A - Resin composition and its cured material - Google Patents

Abstract

PURPOSE:To provide a resin composition containing a polymer of a specific vinyl ether monomer and a curing catalyst, having excellent storage stability as a one-pack composition, giving a cured product having excellent acid resistance, weather resistance, etc., and good coating film appearance and useful in the field of automotive industry. CONSTITUTION:This resin composition contains (A) a polymer of a vinyl ether monomer of formula I (R1 is a 1-5C alkyl; (n) is 1-4) and (B) a curing catalyst. For example, the component A is a polymer produced by polymerizing a vinyl ether monomer of formula II by a solution radical polymerization using toluene, etc., as the solvent and the component B is e.g. a catalyst for opening a cyclocarbonate group, e.g. tetramethylammonium bromide. The amount of the component B is preferably 1-5 pts.wt. based on 100 pts.wt. of the solid content of the component A.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a thermosetting resin composition containing a specific polycyclocarbonate compound and a curing catalyst. In particular, the present invention relates to a very useful thermosetting resin composition excellent in storage stability and excellent in coating film appearance such as chemical resistance, weather resistance, heat resistance and smoothness, and a cured product thereof.

[0002]

2. Description of the Related Art In recent years, mainly in the automobile industry, there has been a movement to attach importance to the outside of the coating film, and in order to maintain the appearance of the coating film such as deterioration under exposure, especially deterioration of the appearance due to acid rain, the current situation is concerned. The coating material composed of the combination of the hydroxyl group-containing acrylic resin and the melamine-based curing agent has a problem that the appearance thereof is deteriorated due to acid rain as it becomes a high solid.
In view of such problems, development of a new curing type resin has been studied. Among them, 1) combination of hydroxyl group-containing resin and polyisocyanate, 2) combination of silanol group-containing resin and epoxy group-containing resin, 3) combination of hydroxyl group-containing resin and acid anhydride group-containing resin, 4) There are systems using a moisture-curable resin having a hydrolyzable silyl group, and 5) a combination of an acid group-containing resin and an epoxy group-containing resin. However, among the above-mentioned resin systems, the combination of the hydroxyl group-containing resin and the polyisocyanate and the combination of the acid group-containing resin and the epoxy group-containing resin have a short pot life and have major drawbacks in workability. Also, in the case of a combination of a silanol group-containing resin and an epoxy group-containing resin, or a moisture-curable resin containing a hydrolyzable silyl group,
There are various drawbacks such as changes in the coating film performance due to the change in the degree of crosslinking of the coating film formed by baking over time, and the unsatisfactory appearance.

[0003]

Further, in addition to such long-term storage stability and appearance of the coating film, a resin system capable of obtaining a coating film that can withstand acid rain mainly in the automobile industry. Development is required.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that it is a one-pack type resin composition having excellent storage stability, and that its cured product is acid resistant. , A resin composition excellent in weather resistance, coating film appearance, and the like, and a cured product thereof have been found. That is, the present invention is a polymer (A) of a vinyl ether monomer represented by the general formula (1).

[0005]

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(In the formula (1), R ₁ is a C _{1 to} C ₅ alkyl group and n is an integer of 1 to 4) and a curing catalyst (B). And a cured product thereof.

In the present invention, the polymer (A) of the vinyl ether monomer represented by the general formula (1) is used. Specific examples of the polymer (A) include, for example, vinyl ether monomers (for example,

[0008]

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[0009]

[Chemical 4]

[0010]

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[0011]

[Chemical 6]

[0012]

[Chemical 7]

And the like) can be mentioned as a polymer which can be obtained by polymerizing them with a conventional method. To prepare the polymer (A), a conventional method such as a solution polymerization method or a non-aqueous dispersion polymerization method may be used, but a solution radical polymerization method is the simplest. At the time of polymerization, particularly typical solvents to be used are, for example,
Toluene, xylene, cyclohexane, n-hexane,
Various hydrocarbon solvents such as solvent naphtha,

There are various ester solvents such as methyl acetate, butyl acetate, ethoxypropionate acetate and carbitol acetate, and various ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and methyl amyl ketone. These may be used alone or in combination of two or more. Further, particularly typical radical polymerization initiators are, for example, azo-based initiators represented by azobisisobutyronitrile, and peroxide-based initiators represented by benzoyl peroxide.
Furthermore, if necessary, various chain transfer agents such as lauryl mercaptan, octyl mercaptan, 2-mercaptoethanol, octyl thioglycolate, 3-mercaptopropionic acid or α-methylstyrene dimer can be used as a molecular weight modifier.

The number average molecular weight of the polymer (A) thus obtained is preferably in the range of 500 to 50,000 from the viewpoint of coating film performance, coatability, workability and the like.

The amount of the polymer (A) contained in the composition of the present invention is preferably 10 to 80% by weight, more preferably 15 to 60% by weight in the composition.

Next, in the present invention, the curing catalyst (B) is used. Examples of the curing catalyst (B) include a cyclocarbonate group ring-opening catalyst and an epoxy group ring-opening catalyst. Of these catalysts, the former cyclocarbonate group ring-opening catalyst is mainly important for cyclocarbonate group-based decarbonation (decarbonation gas) reaction. For example, tetramethylammonium bromide, trimethylbenzylammonium hydroxide, 2-hydroxypyridine, trimethylbenzylammonium methoxide, phenyltrimethylammonium chloride, phenyltrimethylammonium bromide, phenyltrimethylammonium hydroxyside, phenyltrimethylammonium iodide, stearium ammonium bromide. ,
Tetra-n-amyl ammonium iodide, tetra-
n-butylammonium bromide, tetra-n-butylammonium hydroxide, tetra-n-butylammonium phosphate, tetra-n-decylammonium trichloride, tetraethylammonium hydroxide, alkyldimethylbenzylammonium chloride, benzylcholine bromide, benzyl-n -Butylammonium bromide, betaine, quaternary ammonium salts such as trimethylvinylammonium bromide, allyltriphenylphosphonium chloride, n-amyltriphenylphosphonium bromide,
Benzyltriphenylphosphonium chloride, bromomethyltriphenylphosphonium bromide, 2-dimethylaminoethylphenylphosphonium bromide, ethoxycarbonylphosphonium bromide, phosphonium salts such as methyltriphenylphosphonium sulfate, phosphoric acid, p-toluenesulfonic acid, dimethylsulfate, etc. Examples thereof include acid catalysts and carbonates such as calcium carbonate.

The amount of the cyclocarbonate group ring-opening catalyst used is preferably 0.01 to 10 parts by weight, and particularly preferably 1 to 100 parts by weight of the solid content of the polymer (A). ~ 5 parts by weight.

Next, the ring-opening catalyst for the epoxy group is used to accelerate the ring-opening reaction of the epoxy group generated by the decarbonation reaction of the cyclocarbonate group. As such a compound, a basic catalyst usually used in an esterification reaction is preferable, and various quaternary ammonium salts as described above which also have the effect of a cyclocarbonate ring-opening catalyst are preferable. Further, the combined use of triphenylphosphine or the like with the quaternary ammonium salt catalyst is also effective. The amount of the epoxy group ring-opening catalyst used is preferably 0.01 to 10 parts by weight, and particularly preferably 1 to 5 parts by weight, based on 100 parts by weight of the solid content of the polymer (A).

Next, in the present invention, if necessary,
A compound (C) having at least one kind of functional group selected from a carboxyl group, an acid anhydride group and a hydroxyl group, and having neither an acid anhydride group nor a hydroxyl group at the same time, and a curing component having reactivity with the hydroxyl group ( D) can be used.
First, as the former compound (C), for example, vinyl copolymers, polyester resins, alkyd resins and low molecular weight compounds having such specific functional groups are typical. Among them, first of all, vinyl-based copolymers include carboxyl group-containing unsaturated monomers (for example, α, β-ethylenically unsaturated mono-monomers such as (meth) acrylic acid, maleic acid, fumaric acid, and itaconic acid). Or dicarboxylic acids, monobutyl maleate, monobutyl itaconic acid, monoester compounds such as reaction products of phthalic anhydride and 2-hydroxyethyl (meth) acrylate, etc.), or acid anhydride group-containing unsaturated monomer ( (For example, maleic anhydride, tetrahydrophthalic anhydride, etc.)
And / or a hydroxyl group-containing unsaturated monomer (for example, 2-
Hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 1,4-butanediol mono (meth) acrylate, 2-hydroxyethyl vinyl ether, and 1,4-butanediol mono. Hydroxyalkyl vinyl ethers such as vinyl ether, allyl compounds such as allyl alcohol and hydroxyethyl allyl ether, or those obtained by reacting ε-caprolactone with the above-mentioned hydroxyl group-containing unsaturated monomer. ) And another copolymerizable unsaturated monomer (for example, alkyl (meth) acrylate having an alkyl group having 1 to 22 carbon atoms, 2-ethoxyethyl (meth) acrylate, cyclohexyl (meth))
Various (meth) acrylates such as acrylate, glycidyl (meth) acrylate,

[0021]

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[0022]

[Chemical 9]

Various (meth) acrylates containing a reactive functional group such as styrene, tert-butylstyrene, α
-Aromatic vinyl monomers such as methylstyrene, (meth) acrylamide, (meth) acrylamides such as N-alkoxymethyl (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylamino Various amino group-containing (meth) acrylates such as propyl (meth) acrylate, various fluorine-containing vinyl monomers such as tetrafluoroethylene and hexafluoropropylene, (meth) acrylonitrile, vinyl acetate and the like. And those obtained by copolymerizing

Furthermore, the polyester resin or alkyd resin is not special, and examples thereof include polybasic acids (eg, adipic acid, azelaic acid, sebacic acid, dimer acid, (succinic anhydride, 1,4-cyclohexanedicarboxylic acid). Acid, (anhydrous) phthalic acid, tetrahydro (anhydrous) phthalic acid, hexahydro (anhydrous) phthalic acid, methylhexahydro (anhydrous) phthalic acid, isophthalic acid, terephthalic acid, (anhydrous) trimellitic acid, methylcyclohexene tricarboxylic acid, ( Anhydrous) pyromellitic acid, etc.), polyhydric alcohols (for example, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, 1,
3-butanediol, 1,4-butanediol, 1,5
-Pentanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, octanediol, diethylpropanediol,
Butylethyl propanediol, 2-methyl-1,3-
Propanediol, 2,2,4-trimethylpentanediol, hydrogenated bisphenol A, alkylene oxide adduct of bisphenol A, hydrogenated bisphenol A alkylene oxide adduct, glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, tris Hydroxyethyl isocyanurate, etc.),
Alternatively, if necessary, those esterified with an acid having an α, β-ethylenically unsaturated group or a lower alcohol thereof (for example, (anhydrous) maleic acid, monomethyl maleate, monoethyl maleate, fumaric acid, (anhydrous) Itaconic acid and the like), fats and oils or fatty acids, ε-caprolactone, and further monobasic acids (for example, p-tret-butylbenzoic acid) and the like are condensed by a known and commonly used method.

Examples of the low molecular weight compound referred to in the present invention include carboxyl group-containing low molecular weight compounds such as adipic acid, phthalic acid, isophthalic acid and dimer acid, trimellitic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, Examples thereof include acid anhydride group-containing low-molecular compounds such as het anhydride, hymic anhydride, maleic anhydride, itaconic anhydride, and pyromellitic anhydride.

Next, the curing component (D) having reactivity with the above-mentioned hydroxyl group is, for example, a known conventional one such as amino resin, isocyanate prepolymer or blocked isocyanate. Specific examples of the amino resin include melamine resin, benzoguanamine resin, urea resin and the like, which are obtained by adding formaldehyde to melamine, benzoguanamine, and urea and then etherifying with an aliphatic alcohol having 1 to 4 carbon atoms.

Specific examples of the isocyanate prepolymer include tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, trimethylhexane diisocyanate, 4,4'-
Diisocyanate compounds such as methylenebis (cyclohexyl isocyanate), these diisocyanate compounds and ethylene glycol, polyether polyols (polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc.), polycaprolactone polyols, trimethylolpropane, trimethylolethane, and other polyhydric alcohols. And a reaction product with a polyester polyol, a hydroxyl group-containing acrylic polymer, or the like.

Specific examples of the blocked polyisocyanate are those obtained by blocking the above diisocyanate compound by a conventional method. Specific examples of the blocking agent include phenol compounds such as phenol, cresol and xylenol, and methanol. , Alcohol compounds such as ethanol, isopropanol, n-butanol and benzyl alcohol, oxime compounds such as formaldoxime, acetaldoxime and methyl ethyl ketone oxime, lactam compounds such as ε-caprolactam,
Examples thereof include imidazole compounds such as 2-methylimidazole.

The above-mentioned compound (c) mainly acts as a cross-linking agent for the polymer (A) having a cyclocarbonate group. Further, it is crosslinked by the above-mentioned curing component (D). The amount of the compound (C) used is the polymer (A)
0 to 200 parts by weight is preferable for 100 parts by weight of the solid content.

Further, regarding the amount of the functional group of the compound (C), in the case of a carboxyl group, the acid value (mg / KOH / g) is preferably 5 to 200, particularly preferably 10 to 150.
Is. On the other hand, in the case of a hydroxyl group, the hydroxyl value is 10 to 20.
0 is preferable and 20 to 150 is particularly preferable.

Next, as the amount of the curing component (D) used,
0 to 1 based on 100 parts by weight of the solid content of the polymer (A).
00 parts by weight is preferred. Further, in the composition of the present invention, if necessary, various conventionally known leveling agents, defoamers, ultraviolet absorbers, light stabilizers, antioxidants, pigment dispersants, cellulosic compounds, plasticizers, A pigment, an inorganic filler or the like can be added. The composition of the present invention is obtained by dissolving, mixing and dispersing each component, additive and the like.

As a method for curing the resin composition of the present invention,
It can be cured by heating at 60 to 180 ° C.

[0033]

EXAMPLES The present invention will be described in more detail below with reference to examples. The parts in the examples are parts by weight. (Synthesis Example of Polymer (A) of Vinyl Ether Monomer) Synthesis Example 1 A flask equipped with a thermometer, a cooling tube, a stirrer and a nitrogen gas introducing tube was charged with 500 parts of xylene and 300 parts of n-butanol in a nitrogen stream. , A vinyl ether monomer represented by the following formula (ISP
Made by the company, product name PEPC) 1208 parts

[0034]

[Chemical 10]

200 parts of xylene, 10 parts of azobisisobutyronitrile and tert-butylperoxy-2-
5 parts of a mixture of 20 parts of ethyl hexanoate at the same temperature
After dropping over a period of time, after the dropping was completed, the temperature was kept at the same temperature for 7 hours to cause a reaction, and a resin solution (A-1) having a nonvolatile content of 55.3% and a number average molecular weight of 9,000 was obtained. .

(Synthesis Example of Compound (C) that is a Vinyl Copolymer Having a Carboxyl Group) Synthesis Example 2 250 parts of methyl amyl ketone and 200 parts of n-butanol were placed in the same reactor as in Synthesis Example 1 in a nitrogen stream. And ter
After charging 2 parts of t-butyl peroxide and heating to 120 ° C., a mixture of 80 parts of acrylic acid, 320 parts of 2-ethylhexyl methacrylate, 300 parts of methyl methacrylate, 200 parts of styrene and 100 parts of Nn-butoxymethylacrylamide was added. A mixture of 309 parts of xylene, 6 parts of azobisisobutyronitrile, 45 parts of tert-butyl hydroperoxide, and 5 parts of tert-butyl peroxybenzoate was added dropwise over about 6 hours, and 1
Hold at 20 ℃ for 12 hours and then cool to obtain solid acid value (mg
/ KOH / g) 60 and a hydroxyl value of 2 or less, and a compound (C-1) having a nonvolatile content of 60% was obtained.

(Synthesis Example of Compound (C) which is Polyester Resin Having Both Carboxyl Group and Hydroxyl Group) Synthesis Example 3 100 parts castor oil, 576 hexahydrophthalic anhydride
Part, 161 parts of trimethylolpropane and 211 parts of neopentyl glycol are charged and heated to 150 ° C.,
Then, the temperature was raised to 180 ° C. in about 2 hours. Further, after reacting at the same temperature for 5 hours, the mixture was cooled and 430 parts of xylene, n
-Built-in 108 parts butanol, non-volatile part 65.2
%, The solid content acid value (mgKOH / g) was 60, and the solid content hydroxyl value was 70 (C-2).

(Synthesis Example of Compound (C) which is Polyester Resin Having Hydroxyl Group) Synthesis Example 4 312 parts of hexahydrophthalic anhydride, 297 adipic acid
Parts, 72 parts of trimethylolpropane, 427 parts of neopentyl glycol and 0.5 parts of dibutyltin oxide are charged and heated to 150 ° C., then 230 parts in about 4 hours.
The temperature was raised to ℃, and after reacting at the same temperature for 1 hour, xylene
Parts were charged, the reaction was continued for further 7 hours, cooled, and 508 parts of xylene were charged to obtain a compound (C-3) having a nonvolatile content of 65.0% and a solid hydroxyl value of 98.

Examples 1 to 4 and Comparative Example 1 According to the composition of Table 1, the polymer (A-1) having a cyclocarbonate group prepared in Synthesis Example 1 and the carboxyl prepared in Synthesis Examples 2 to 4 were used. A total of 100 parts by weight per solid content of a resin component comprising a compound having a group and / or a hydroxyl group (C-1, C-2, C-3) and a butyletherified melamine resin (D component), and then a curing catalyst ( B) was blended and then a solvent was blended to prepare a resin composition. The obtained resin composition is spray-coated on a zinc phosphate-treated steel plate to a film thickness of about 30 μ, and then 1
It heated at 30 degreeC for 20 minutes, and obtained the cured coating film. Various performances were evaluated. The results are collectively shown in Table 1.
The evaluation of various properties of the resin composition and the cured coating film was performed by the following methods.

Stability of resin composition: The composition was allowed to stand at 50 ° C. for 7 days, and the degree of change in viscosity was observed. Gel fraction: Cured coating in methyl ethyl ketone at room temperature 2
After soaking for 4 hours, the insoluble matter was measured. Pencil hardness: Evaluated according to JIS K5400. Acid resistance: After being immersed in a 5% aqueous solution of sulfuric acid at 40 ° C. for 24 hours, the state change of the coating film was visually determined. Weather resistance: 100 using a sunshine weatherometer
After conducting an accelerated weathering test for 0 hours, the 60 ° gloss retention is expressed in%. Appearance of coating film: Each coating material was spray-coated on the glass surface, and after heat curing, the smoothness of the skin of the cured coating film was visually evaluated.

[0041]

Table 1 Example 1 2 3 4 Polymer obtained in Synthesis Example 1 (A-1) 180.8 108.5 108.5 99.4 Compound obtained in Synthesis Example 2 (C-1) 66.7 Compound obtained in Synthesis Example 3 (C-2) 66.7 Compound obtained in Synthesis Example 4 (C-3) 38.5 Trimethylbenzylammonium hydroxide 1.0 2-Hydroxypyridine 1.0 Triethylammonium chloride 1.0 1.0 Butyletherified melamine resin 20 Solvent naphtha 50 Xylene 20 n-Butanol 10 Cellosolve Acetate 20 Stability No change No change No change No change Gel fraction (%) 98.5 98.1 98.3 99.2 Pencil hardness 5H 3H 3H 6H Acid resistance No change No change No change Weather resistance (%) 80 78 79 81 Coating appearance Good good good good

As is clear from the evaluation results in Table 1, the storage stability is good, the cured coating film has a high gel fraction, the pencil hardness, the acid resistance and the weather resistance are excellent, and the coating film appearance is also good. .

[0043]

The resin composition of the present invention, as a one-pack type,
It has excellent storage stability, and the cured product has excellent acid resistance, weather resistance, etc. and a good coating film appearance.

Claims (2)

[Claims] 1. A polymer (A) of a vinyl ether monomer represented by the general formula (1): (In the formula, R ₁ is a C _{1 to} C ₅ alkyl group, and n is an integer of 1 to 4) and a curing catalyst (B) are contained in the resin composition. 2. A cured product of the resin composition according to claim 1.