JPH0342315B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a resin composition for coating, and more particularly, it comprises a specific hydroxyl group-containing vinyl copolymer, an ε-caprolactone-modified polyester polyol, and further an isocyanate compound or an amino resin as essential components. The present invention relates to a composition. Recently, the range of coating base materials has gradually expanded from metal bases such as iron to flexible materials such as plastics and rubber, and as a result, coatings on the latter materials have become extremely common. Furthermore, there is a demand for flexible covering materials or coating materials used therein. In this way, in order to obtain a coating material or coating material that provides a flexible cured coating film, acrylic polyols with a low glass transition point, polyhydric alcohols and polyhydric carboxylic acids are used as coating film-forming resin components. Polyester polyols obtained from and the like are effective. However, although cured coatings obtained using such acrylic polyols with low glass transition points and isocyanate compounds or amino resins have flexibility, they do not have sufficient hardness and solvent resistance, and they are not compatible with polyester polyols. Cured coating films obtained using isocyanate compounds or amino resins do not have sufficient weather resistance or flexibility at low temperatures. As described above, it is unlikely that a cured coating film that satisfies all of weather resistance, solvent resistance, and flexibility can be obtained from coating resin compositions that have the above-mentioned combinations. However, the present inventors have obtained a coating resin composition that can provide a cured coating film with excellent weather resistance, solvent resistance, and flexibility on flexible substrates such as plastics or rubber. As a result of intensive studies, it was discovered that a resin composition consisting of a hydroxyl group-containing vinyl copolymer, an ε-caprolactone-modified polyester polyol, and an isocyanate compound or an amino resin meets these objectives, and the present invention has been completed. I reached it. That is, the present invention consists of 1 to 40% by weight of a hydroxyl group-containing monomer, 99 to 10% by weight of (meth)acrylic acid ester, and 0 to 50% by weight of other copolymerizable monomers. Hydroxyl group-containing vinyl copolymer (A)
50 to 90 parts by weight and 50 parts by weight of ε-caprolactone modified polyester polyol (B) with a hydroxyl value of 20 to 300.
10 parts by weight of the isocyanate compound (C) and an appropriate amount of the isocyanate compound (C) as essential components. 90 parts by weight, 50 to 10 parts by weight of the above ε-caprolactone-modified polyester polyol (B), and an appropriate amount of an amino resin (D) as essential components. It is. Here, typical examples of the above-mentioned hydroxyl group-containing monomers include β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate,
-Hydroxybutyl acrylate or β-hydroxybutyl methacrylate, 3-chloro-2-
Hydroxypropyl (meth)acrylate, di-
2-hydroxyethyl fumarate, mono-2-hydroxyethyl-monobutyl fumarate, or mono(meth)acrylate of polyethylene glycol or polypropylene glycol,
"Plaxel FM or FA monomer" [Caprolactone addition monomers manufactured by Daicel Chemical Co., Ltd.]
Hydroxyalkyl esters of α,β-ethylenically unsaturated carboxylic acids such as, or adducts of these with ε-caprolactone: (meth)acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid or citraconic acid unsaturated mono- or dicarboxylic acids such as, α,β-ethylenically unsaturated carboxylic acid hydroxyalkyl esters such as monoesters of these dicarboxylic acids and monohydric alcohols, and maleic acid, succinic acid, and phthalic acid. , hexahydrophthalic acid, tetrahydrophthalic acid, benzenetricarboxylic acid, benzenetetracarboxylic acid, "Himic acid" (product of Hitachi Chemical Co., Ltd.), anhydrides of polycarboxylic acids such as tetrachlorophthalic acid or dodecynylsuccinic acid. Various unsaturated carboxylic acids such as adducts of
"Cardilla E" (glycidyl esters of branched synthetic resin acids manufactured by Siel in the Netherlands), monoglycidyl esters of monovalent carboxylic acids such as coconut oil fatty acid glycidyl esters or glycidyl octylate esters or butyl glycidyl ether, ethylene oxide or adducts with monoepoxy compounds such as propylene oxide, or adducts with these and ε-caprolactone; (including degenerated types). In addition, typical examples of the above-mentioned (meth)acrylic esters include methyl (meth)acrylate, ethyl (meth)acrylate (meth)
n-butyl acrylate, i-(meth)acrylate
Butyl, 2-ethylhexyl (meth)acrylate,
Examples include lauryl (meth)acrylate and cyclohexyl (meth)acrylate. Furthermore, representative examples of the other copolymerizable monomers mentioned above include diesters of unsaturated dibasic acids such as styrene, dibutyl fumarate, dimethyl maleate, or dibutyl itaconate; Monomers containing acid groups, such as acrylic acid, fumaric acid or maleic acid, (meth)
Phosphorous atom-containing monomers such as acryloyloxyalkyl acid phosphates, silicon atom-containing monomers such as “KR-215” or “X-22-5002” [products of Shin-Etsu Chemical Co., Ltd.], or ( Acid amide monomers such as meth)acrylamide, etc.
Furthermore, there is no problem in using a portion of (meth)acrylonitrile or dimethylaminomethyl (meth)acrylate in combination. In order to prepare the above-mentioned hydroxyl group-containing vinyl copolymer (A) using the monomers listed above, aromatic systems such as toluene or xylene, ester systems such as ethyl acetate or butyl acetate, methyl ethyl ketone or methyl isobutyl Solution polymerization can be easily carried out using a ketone solvent such as ketone in the presence of a known and commonly used polymerization initiator that generates radical groups. On the other hand, in order to prepare the above-mentioned ε-caprolactone-modified polyester polyol (B), ε-
- This may be a method of adding caprolactone, or a method of adding ε-caprolactone to a polyhydric alcohol in advance and then esterifying a polyhydric carboxylic acid or even a monoepoxide or diepoxide. You can read it. Here, typical polyhydric alcohols include ethylene glycol, 1,4-butanediol, 1,6-hexanediol, glycerin, trimethylolpropane, and pentaerythritol, but of course, a mixture of these alcohols may be used. On the other hand, typical examples of the polycarboxylic acids mentioned above include succinic acid, adipic acid, azelaic acid, sebacic acid, decane-1,10-dicarboxylic acid, terephthalic acid, isophthalic acid, or phthalic acid (anhydride). Examples include acids, but these may of course be used in the form of a mixture. In addition to the compounds mentioned above, itaconic acid, fumaric acid, maleic acid, etc. can be used as the acid component, and oils and fats such as soybean oil, coconut oil, castor oil, tall oil, etc. can be used as acid components. Alternatively, there is no problem in using fatty acids obtained from the oil in combination with the above-mentioned compounds. Furthermore, typical monoepoxides or diepoxides mentioned above include "Carduura E" (glycidyl ester of Versateic acid manufactured by Schiel, Netherlands) and compounds commonly used as epoxy resins. The hydroxyl value of the thus obtained ε-caprolactone modified polyester polyol (B) is usually 20 to 300, but the isocyanate compound (C)
When used in combination with amino resin (D), the range is preferably from 25 to 200. On the other hand, when used in combination with amino resin (D), the range is preferably from 25 to 100. The polyester polyol (B) is used together with the hydroxyl group-containing vinyl copolymer (A) to constitute the "base polyol" component in the composition of the present invention. In other words, the hydroxyl group-containing vinyl copolymer (A) and this ε
-Caprolactone-modified polyester polyol (B)
The composition consisting of is cured with an isocyanate compound (C) or an amino resin (D), and the cured coating film thus obtained has excellent flexibility and solvent resistance. Here, the usage ratio (weight ratio) of the hydroxyl group-containing vinyl copolymer (A) and the ε-caprolactone modified polyester polyol (B): (A)/(B) = 50-90/50-10,
Preferably, (A)/(B)=60-80/40-20, and within this range, a coating film with good coating performance can be obtained. When the hydroxyl group-containing vinyl copolymer (A) is less than 50 parts by weight, the weather resistance is insufficient, and on the other hand, ε
-Caprolactone-modified polyester polyol (B)
If the amount is less than 10 parts by weight, it is not preferable because the flexibility of the coating film cannot be obtained. Next, in the present invention, typical isocyanate compounds (C) used as the curing agent (crosslinking agent) component include aromatic diisocyanates such as tolylene diisocyanate and diphenylmethane diisocyanate; hexamethylene diisocyanate, trimethyl Aliphatic diisocyanates such as hexane diisocyanate; isophorone diisocyanate, methylcyclohexane-2,4
(or 2,6-) diisocyanate, 4,
Alicyclic diisocyanates such as 4'-methylenebis(cyclohexyl isocyanate) and 1,3-di(isocyanatomethyl)cyclohexane; or these diisocyanates and ethylene glycol, polyether polyols (polyethylene glycol, polypropylene glycol, polycaprolactone polyols, etc.). ), polyhydric alcohols such as trimethylolethane and trimethylolpropane, low molecular weight polyester resins (including oil-modified types) that have functional groups that can react with isocyanate groups, acrylic copolymers, water, etc. Adducts; or biuret bodies, copolymers of diisocyanates (including oligomers); furthermore, 2-hydroxypropyl (meth)acrylate-hexamethylene diisocyanate equimolar adducts, and isocyanate groups such as isocyanate ethyl methacrylate; Copolymers Known and commonly used so-called prepolymers with free isocyanate groups that are reactive with active hydrogen, such as copolymers that contain vinyl monomers as essential components and unsaturated double bonds. etc. can be used,
Commercially available compounds (C) include "Barnoc D-750, DN-950" (products of Dainippon Ink & Chemicals Co., Ltd.) and "Desmodyur N".
(product of Bayer, West Germany). On the other hand, typical examples of the crosslinking agent that is the amino resin (D) include methylolization of an amino group-containing compound such as melamine, urea, or guanamine with an aldehyde such as formalin, and then a lower aliphatic alcohol. There are products in which at least two of the methylol groups are etherified, and typical commercially available products include "Betsukamine P-138",
Examples include "Supervetsucomin J-820" (product of Dainippon Ink & Chemicals Co., Ltd.) and "Cymel 300" (product of American Cyanamid, Inc.). In obtaining the composition of the present invention, the blending ratio of the base polyol component consisting of the above-mentioned hydroxyl group-containing vinyl copolymer (A) and ε-caprolactone-modified polyester polyol (B) and the curing agent component is as follows: Although it varies depending on the type of the curing agent component, it is roughly as follows. That is, it is appropriate that the solid content weight ratio of the base polyol component and the amino resin (D) component is in the range of 90/10 to 60/40, while the solid content weight ratio of the base polyol component and the isocyanate compound (C) component is An appropriate solid content weight ratio is within a range where the ratio of the number of hydroxyl groups in the base polyol component to the number of isocyanate groups in the isocyanate compound (C) is 1/0.5 to 1/1.5. , weather resistance and solvent resistance can be ensured. Both curing agents or crosslinking agent components listed above and each of the above-mentioned hydroxyl group-containing vinyl copolymers
The cured coating film obtained using the coating resin composition of the present invention, which has a base resin (base polyol) component consisting of (A) and ε-caprolactone-modified polyester polyol (B) as essential components, is extremely flexible. The composition of the present invention can be applied to a wide range of substrates because it has excellent flexibility and impact resistance, especially at low temperatures, and also has excellent weather resistance and solvent resistance. For example, the composition of the present invention can be used not only as a coating agent for painting metals but also on flexible materials such as plastics or rubber, as well as on wood products or concrete products. Suitable for materials that require flexibility, such as for automobile bumpers. Next, the present invention will be specifically explained with reference to Reference Examples, Examples, and Comparative Examples. In the following, all parts and percentages are based on weight unless otherwise specified. Reference Example 1 [Preparation example of hydroxyl group-containing vinyl copolymer (A)] 250 g of toluene and 500 g of butyl acetate were supplied to a reactor equipped with a stirrer and a cooler, and the temperature inside the reactor was raised to 120°C. Heat and maintain at the same temperature, add 200 g of styrene, 400 g of n-butyl methacrylate,
Dissolve 5 g of azobisisobutyronitrile and 5 g of t-butyl peroxybenzoate in a monomer mixture consisting of 195 g of n-butyl acrylate, 200 g of β-hydroxyethyl methacrylate, and 5 g of acrylic acid, and 250 g of toluene. The dissolved material was added dropwise into the reactor over a period of 4 hours, and the temperature was kept at the same temperature for 10 hours. The nonvolatile content (NV) was 50.2%, and the hydroxyl value of the copolymer solution was 50.2%.
A solution of the hydroxyl group-containing vinyl copolymer (A) No. 43 was obtained. Hereinafter, this will be abbreviated as copolymer (A-1). Reference example 2 (same as above) 250 g of toluene was placed in the same reaction vessel as in reference example 1.
and 500g of butyl acetate, and the temperature inside the container was
Raise the temperature to 120℃, and at the same temperature, add 150g of styrene, 400g of n-butyl methacrylate, and 195g of n-butyl acrylate.
g, β-hydroxyethyl methacrylate 250g,
A monomer mixture consisting of 5 g of acrylic acid and 5 g of azobisisobutyronitrile in 250 g of toluene.
and 5 g of t-butyl peroxybenzoate
NV was added dropwise over 4 hours and kept at the same temperature for 10 hours.
A solution of the hydroxyl group-containing vinyl copolymer (A) having a hydroxyl value of 50.5% and a hydroxyl value of 54 was obtained. Hereinafter, this will be abbreviated as copolymer (A-2). Reference Example 3 [Preparation example of ε-caprolactone modified polyester polyol (B)] 398.6 g of adipic acid, trimethylolpropane
153.9g, 404g of 1,6-hexanediol and 180g of isophthalic acid.
Next, 428.6 g of ε-caprolactone was added to this for an addition reaction, and the hydroxyl value of the solid content was 105.
An ε-caprolactone modified polyester polyol was obtained. Afterwards, this polyester polyol
A solution of ε-caprolactone-modified polyester polyol (B) having an NV of 60.5% and a hydroxyl value of 63 was obtained by dissolving it in 666.6 g of xylene and 285.7 g of methyl isobutyl ketone. Hereinafter, this will be abbreviated as polyol (B-1). Reference Example 4 (Same as above) An esterification reaction was carried out using 369.6 g of phthalic anhydride, 157.6 g of trimethylolpropane, and 517 g of "Carduura E", and then an addition reaction was carried out by adding 259.2 g of ε-caprolactone. An ε-caprolactone modified polyester polyol having a hydroxyl value of 123.5 was obtained. Afterwards, this polyester polyol
A solution of ε-caprolactone modified polyester polyol (B) having an NV of 60.1% and a hydroxyl value of 74 was obtained by dissolving it in 604 g of xylene and 259 g of methyl isobutyl ketone. Hereinafter, this will be abbreviated as polyol (B-2). Example 1 100% of the copolymer (A-1) obtained in Reference Example 1
of the polyol (B-1) obtained in Part and Reference Example 3.
35.7 parts and then "Taipeke R-820"
After mixing 47.6 parts of methyl-type titanium oxide manufactured by Ishihara Sangyo Co., Ltd. and dispersing it with a sand mill, the mixture was further mixed with ``Barnok DN-950'' [Dainippon Ink Chemical Industry Co., Ltd.].
After adding 39.2 parts of Isocyanate Compound (manufactured by Co., Ltd.) and diluting with thinner to adjust the viscosity of the paint, it was spray-painted on a mild steel plate and force-dried at 80°C for 30 minutes. Physical property tests were conducted on the cured coating film obtained here, and the results shown in Table 1 were obtained. Examples 2 to 4 and Comparative Example 1 Coating resin compositions were obtained at the blending ratios shown in Table 1, and then cured coating films were obtained using the respective coating resin compositions. Physical property tests on the membrane were conducted in the same manner as in Example 1. The results are summarized in the same table, and the evaluation criteria are as follows. ◎...Excellent〇...Good ×...Unsatisfactory

【table】

[Table] Examples 5 to 8 and Comparative Example 2 First, the hydroxyl group-containing vinyl copolymer (A) and the ε-caprolactone-modified polyester polyol (B) were mixed at the blending ratios shown in Table 2, and then the ε-caprolactone modified polyester polyol (B) was mixed. Disperse "Tiepeke R-820" with a sand mill,
Furthermore, after adding "Super Betsukamine L-117-60" [melamine resin manufactured by Dainippon Ink & Chemicals Co., Ltd.], dilute it with thinner to adjust the viscosity of the paint, and then apply each of the resulting paints. It was spray painted on a mild steel plate and then baked at 150°C for 20 minutes. Physical property tests were conducted on each of the cured coating films thus obtained, and the results shown in the table were obtained. The evaluation criteria for each physical property are as follows. ◎...Excellent〇...Good ×...Unsatisfactory

【table】

Claims (1)

[Scope of Claims] 1 1 to 40% by weight of a hydroxyl group-containing monomer, and (meth)
50 to 90 parts by weight of a hydroxyl group-containing vinyl copolymer (A) consisting of 99 to 10% by weight of acrylic ester and 0 to 50% by weight of other copolymerizable monomers, and a hydroxyl value of 20 A resin composition for coating, characterized in that it contains 50 to 10 parts by weight of an ε-caprolactone-modified polyester polyol (B) of ~300 and an isocyanate compound (C) as essential components. 2 1 to 40% by weight of hydroxyl group-containing monomer and (meth)
50 to 90 parts by weight of a hydroxyl group-containing vinyl copolymer (A) consisting of 99 to 10% by weight of acrylic ester and 0 to 50% by weight of other copolymerizable monomers, and a hydroxyl value of 20 A resin composition for coating, characterized in that it contains 50 to 10 parts by weight of an ε-caprolactone-modified polyester polyol (B) of ~300 and an amino resin (D) as essential components.