JP2832438B2 - Thermosetting composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to various kinds of coatings such as architectural exteriors, automobiles, industrial machines, steel furniture, household appliances, plastics, etc., particularly applications requiring durability. The present invention relates to a thermosetting composition used for painting.

(Conventional technology and problems) Fluorine-based copolymers have good weather resistance and ultraviolet resistance, and are used in paints and coating agents. Conventionally, thermoplastic fluorine-based copolymers have been used, but recently various types of curable fluorine-based copolymers have been developed due to the development of various fluorine-based monomers and advances in the analysis of copolymerizability. Also, the weather resistance is evaluated as being equal to or higher than that of the conventional thermoplastic fluorine-based copolymer. However, isocyanate, melamine, and the like are used as a curing crosslinking agent, and there are problems due to the curing agent, such as toxicity due to isocyanate and odor of melamine.

An object of the present invention is to provide a thermosetting composition free from the above-mentioned problems by using a hydrolyzable silyl group-containing vinyl copolymer instead of isocyanate and melamine.

On the other hand, the hydrolyzable silyl group-containing vinyl copolymer is
Due to features such as weather resistance, stain resistance, corrosion resistance, appearance, adhesion, and low-temperature curability, development has been promoted in the fields of exteriors, automobile repair, and the like.

An object of the present invention is to solve the above-mentioned problems and to further improve the durability characteristics of the fluorine-based copolymer and the hydrolyzable silyl group-containing vinyl copolymer.

(Means and Effects for Solving the Problems) The present invention relates to a hydroxyl-containing fluorine-containing copolymer having a hydroxyl value of 10 to 250 mgKOH / g, a hydrolyzable silyl-containing vinyl copolymer (B), and a curing catalyst (C). ) Is a thermosetting composition.

The present invention utilizes a crosslinking reaction between a hydroxyl group contained in a fluorine-based copolymer and a hydrolyzable silyl group contained in a vinyl-based copolymer, and provides a conventional crosslinking between a hydroxyl group, an isocyanate, and melamine. This is a new crosslinking reaction that is completely different from the reaction.

The hydroxyl group-containing fluorine-based copolymer (A) used in the present invention is a fluoroolefin such as chlorotrifluoroethylene, tetrafluoroethylene or trifluoroethylene; CH ₂ ＝ CHCOOCH ₂ CF ₃ , CH ₂ CC (CH ₃ ) COOCH ₂ CF ₃ , CH
_{2 = CHCOOCH (CF 3) 2} , CH 3 = C (CH 3) COOCH (CF 3) 2, CH 2 = CHC
OOCH ₂ CF ₂ CF ₂ CF ₃ , CH ₂ = CHCOOCF ₃ , CH ₂ = C (CH ₃ ) COOCH ₂ CF
A fluorine-containing vinyl monomer such as fluoroalkyl (meth) acrylate, including ₂ CF ₂ CF ₃ , CH ₂ CC (CH ₃ ) COOCF _{3 and the} like;
Hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, hydroxyalkyl vinyl ether such as hydroxyhexyl vinyl ether; 2-hydroxyethyl acrylate,
2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, N-methylol acrylamide, N-methylol methacrylamide, Alonix 5700 (manufactured by Toagosei Co., Ltd.), Placel FA-1 and FA-4, FM-1
Hydroxyl-containing vinyl monomers such as FM-4 (manufactured by Daicel Chemical Industries, Ltd.); alkyl vinyl ethers such as ethyl vinyl ether, propyl vinyl ether and butyl vinyl ether; cyclohexyl vinyl ether; maleic acid, fumaric acid, acrylic acid, methacrylic acid, and carboxylalkyl Carboxyl group-containing monomers such as vinyl ether; ethylene, propylene, vinyl chloride, vinylidene chloride, vinyl acetate; unsaturated carboxylic esters such as methyl methacrylate and methyl acrylate; vinyl triethoxysilane, γ- (meth) acryloyloxypropyl tri A hydroxyl value obtained by copolymerizing the above, such as a hydrolyzable silyl group-containing monomer such as methoxysilane;
It is 10-250 mgKOH / g.

The hydrolyzable silyl group-containing vinyl copolymer (B) used in the present invention has a main chain substantially consisting of a polyvinyl type bond, and one molecule of a silicon atom bonded to a terminal or side chain with a hydrolyzable group. A vinyl resin having at least one silyl group therein, which is obtained by copolymerization of a vinyl monomer and a hydrolyzable silyl group-containing monomer, and may partially contain a urethane bond or a siloxane bond in a main chain or a side chain. The vinyl monomer is not particularly limited, and may be methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) ) Crylate, trifluoroethyl (meth) acrylate, pentafluoropropyl (meth) acrylate, diester of a polycarboxylic acid (maleic acid, fumaric acid, itaconic acid, etc.) with a linear or branched alcohol having 1 to 20 carbon atoms or Esters of unsaturated carboxylic acids such as half esters; styrene,
Aromatic hydrocarbon-based vinyl compounds such as α-methylstyrene, chlorostyrene, styrenesulfonic acid, 4-hydroxystyrene, and vinyltoluene; vinyl esters and allyl compounds such as vinyl acetate, vinyl propionate, and diallyl phthalate; Vinyl compounds containing a nitrile group such as nitrile; vinyl compounds containing an epoxy group such as glycidyl (meth) acrylate; vinyl compounds containing an amino group such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, vinyl pyridine, and aminoethyl vinyl ether ; (Meth) acrylamide,
Itaconic acid diamide, α-ethyl (meth) acrylamide, crotonamide, maleic acid diamide, fumaric acid diamide, N-vinylpyrrolidone, N-butoxymethyl (meth) acrylamide, N, N-dimethylacrylamide, N-methylacrylamide, acryloyl Amide group-containing vinyl compounds such as morpholine; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth)
Acrylate, 2-hydroxyethyl vinyl ether, N
-Methylol (meth) acrylamide, Aronix 5700
(Manufactured by Toa Gosei Co., Ltd.), Placcel FA-1, Placcel FA-
4. Vinyl compounds containing hydroxyl group such as Placcel FM-1 and Placcel FM-4 (all manufactured by Daicel Chemical Co., Ltd.);
Crylic acid, maleic acid, fumaric acid, itaconic acid and salts thereof (alkali metal salts, ammonium salts, amine salts, etc.), unsaturated carboxylic acids such as maleic anhydride, acid anhydrides or salts thereof; vinyl methyl ether, Other vinyl compounds such as vinyl chloride, vinylidene chloride, chloroprene, propylene, butadiene, isoprene, maleimide, N-vinylimidazole, and vinyl sulfonic acid.

As the alkoxysilane vinyl monomer, specifically, And the like.

These alkoxysilane vinyl monomer units are preferably contained in the copolymer (B) in an amount of 5 to 90% by weight.

A method for producing a copolymer of an alkoxysilane vinyl monomer and a vinyl monomer is described in, for example, JP-A-54-3639.
5, methods 57-36109 and 58-157810 may be used. Solution polymerization using an azo radical initiator such as azobisisobutyronitrile is most preferred. If necessary, n-dodecyl mercaptan, t-dodecyl mercaptan, n-butyl mercaptan, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiphenyl _{ethoxysilane, (H 3 CO) 3 Si} -S-S-Si (OCH 3) 3, (CH 3 O) 3 Si
With -S ₈ -Si (OCH ₃₎ a chain transfer agent such as _3, can be a molecular weight modifier. In particular, when a chain transfer agent having a hydrolyzable silyl group in the molecule, for example, γ-mercaptopropyltrimethoxysilane, a hydrolyzable silyl group can be introduced into the terminal of the silyl group-containing vinyl copolymer. The polymerization solvent is a hydrocarbon (toluene, xylene, n-
Hexane, cyclohexane, etc.), acetates (ethyl acetate, butyl acetate, etc.), alcohols (methanol,
Ethanol, isopropanol, n-butanol, etc.),
There is no particular limitation as long as it is a non-reactive solvent such as ethers (ethyl cellosolve, butyl cellosolve, cellosolve acetate, etc.) and ketones (methyl ethyl ketone, ethyl acetoacetate, acetylacetone, diacetone alcohol, methyl isobutyl ketone, acetone, etc.).

Specific examples of the curing catalyst of the component (C) include organic tin compounds such as dibutyltin dilaurate, dibutyltin dimaleate, dioctyltin dilaurate, dioctyltin dimaleate, and tin octylate; phosphoric acid, monomethyl phosphate, monoethyl phosphate, Monobutyl phosphate, monooctyl phosphate, monodecyl phosphate, dimethyl phosphate, diethyl phosphate, dibutyl phosphate, dioctyl phosphate,
Phosphoric acid or phosphoric acid ester such as didecyl phosphate; propylene oxide, butylene oxide, cyclohexene oxide, glycidyl methacrylate, glycidol, acrylic glycidyl ether, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane Γ-glycidoxypropylmethyldimethoxysilane, Cardaura E (Yuka Kasei Co., Ltd.), Epikote 828
Addition reaction products of epoxy compounds such as (Yuika Ciel Co., Ltd.) and Epikote 1001 (Yuika Ciel Co., Ltd.) with phosphoric acid and / or monoacid phosphate; organic titanate compounds; organic aluminum compounds; Acidic compounds such as acid and p-toluenesulfonic acid; amines such as hexylamine, di-2-ethylhexylamine, N, N-dimethyldodecylamine and dodecylamine; reactants of these amines with acidic phosphate esters; And alkaline compounds such as sodium and potassium hydroxide. Among these curing catalysts, organotin compounds, acid phosphates, reactants of acid phosphates and amines, saturated or unsaturated polycarboxylic acids or anhydrides thereof, reactive silicon compounds, organic titanate compounds, Organoaluminum compounds or mixtures thereof have high activity and are excellent.

The mixing ratio of (A) and (B) is arbitrary, but preferably (A) / (B) is 9/1 to 1/9, and (A) and (B) are cold-blended or mixed. After that, heating (hot blending) or the like may be performed to cause a partial reaction.

Also, an alkyd resin having a hydroxyl group, an oil-free alkyd resin, an acrylic-modified alkyd resin, an acrylic resin,
It is possible to improve the physical properties by adding a resin or a compound which can be co-crosslinked with the composition of the present invention, such as a polyester resin, an epoxy resin, a hydroxyl group-containing silicone oil, a silanol group-containing compound, and a silanol group-containing polysiloxane.

The curing catalyst (C) can be used in an amount of 0 to 20 parts by weight, preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the solid content of (A) and (B).

Although a dehydrating agent may or may not be used in the composition of the present invention, a dehydrating agent can be used in order to ensure long-term stability and stability without any problem even when used repeatedly. As the dehydrating agent, specifically, methyl orthoformate, ethyl orthoformate, methyl orthoacetate, ethyl orthoacetate,
There are hydrolyzable ester compounds such as methyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, methylsilicate and ethylsilicate. These hydrolyzable ester compounds may be added during the polymerization of the silyl group-containing vinyl copolymer (B) or may be added to the polymerization system. It is also possible to add alcohols from the viewpoint of storage stability, and improvement can be obtained by using methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol or the like.

The composition of the present invention may contain additives such as various solvents, diluents, pigments (including extenders), ultraviolet absorbers, anti-settling agents, leveling agents, etc., depending on the intended use; nitrocellulose, cellulose acetate butyrate, etc. Resin such as epoxy resin, melamine resin, vinyl chloride resin, chlorinated polyolefin, chlorinated rubber and polyvinyl butyral.

The composition of the present invention is applied at a temperature of 30 ° C. or higher, preferably 55 ° C., after being applied to a substrate by a conventional method such as dipping, spraying, or brushing.
Can be cured between ℃ and 350 ℃.

(Example) Next, an example of the present invention will be described. In the examples, “parts” and “%” are based on weight.

(Resin Production Example) 45.9 parts of xylene was charged into a reaction vessel equipped with a stirrer, thermometer, reflux condenser, N ₂ gas introduction tube, and dropping funnel, and the temperature was raised to 110 ° C. while introducing N ₂ gas. Thereafter, the mixture (a) shown below was dropped at a constant speed for 5 hours using a dropping funnel.

Mixture (a) Styrene 12.8 parts Methyl methacrylate 50.1〃 Stearyl methacrylate 6.9〃 γ-methacryloxypropyltrimethoxysilane 30.2〃 Xylene 13.5〃 2,2'-azobisisobutyronitrile 4.5〃 Dropping of mixture (a) is completed Thereafter, 0.5 parts of 2,2'-azobisisobutyronitrile and 5 parts of toluene were added dropwise at a constant speed over 1 hour. After dropping, aging at 110 ° C for 2 hours, cooling,
Xylene was added to the resin solution to adjust the solid content to 60%.
Table 1 shows the properties of the obtained resin solution [A].

Examples 1 to 3 and Comparative Example 1 As a hydroxyl group-containing fluorine-based copolymer, lumifuron LF-100 (trade name of Asahi Glass Co., Ltd., solid content concentration 50), which is a copolymer of fluoroolefin, hydroxyalkyl vinyl ether and alkyl vinyl ether, was used. Weight%, hydroxyl value 32),
The test was performed using the resin solution [A] of the resin production example as a hydrolyzable silyl group-containing vinyl resin. A resin solution A, Lumiflon LF-100, TN801 (curing catalyst; dioctyltin malate, manufactured by Sakai Chemical Engineering Co., Ltd.) and a toluene composition shown in Table 2 were coated with a No. 40 bar coater to give a coating having a thickness of 25 μm. A membrane was made.

The gel fraction was determined by coating on a polyethylene film or a fluororesin film by the above-described method, peeling after baking, and extracting with an acetone. The gel fraction after immersion in 60 ° C hot water for 20 days was determined by painting on a polyethylene film or fluorine resin film by the above method, baking, immersing in 60 ° C warm water for 20 days, and then extracting with acetone. Was. The magic contamination was determined by painting on an aluminum (A-5052) plate by the above method, applying red magic and black magic 3 days after baking.
One day later, it was wiped with methanol and the surface condition was observed. Table 2 shows the results.

HMDI: Coronate EX (manufactured by Nippon Polyurethane Industry) Melamine resin: Uban 20SE (manufactured by Mitsui Toatsu) Adhesive life: 3 days after baking at 90 ° C. for 20 minutes, 25 mm squares were cut with 25 cutters, and a cellophane tape peeling test was performed. Number is 25
Indicates that the film is not peeled off, and 0 indicates that the film is completely peeled off.

The secondary adhesion is an evaluation after immersion in hot water at 40 ° C. for 10 days.

* Gel fraction after immersion in hot water at 60 ° C for 20 days It can be seen that the composition of the present invention (Examples 1 and 2) forms a stable crosslinked coating film. Also, when no curing catalyst is contained (Example 3), the gel fraction immediately after baking is low, but it can be seen that a stable crosslinked coating film is formed by immersion in warm water.

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiro Nambu 7-1722-20 Tsutsujigaoka, Tarumi-ku, Kobe-shi, Hyogo (56) References JP-A-2-34605 (JP, A) JP-A-63-89559 (JP) JP-A-62-185740 (JP, A) JP-A-62-7767 (JP, A) JP-A-61-60748 (JP, A)

Claims (3)

(57) [Claims] (A) a hydroxyl group-containing fluorine-containing copolymer having a hydroxyl value of 10 to 250 mg KOH / g; (B) a hydrolyzable silyl group-containing vinyl copolymer; (C) a solid copolymer of (A) and (B); 0-2 for 100 parts by weight of mold
0 parts by weight of a curing catalyst were added, and the molar ratio of hydroxyl groups to silicon, OH / Si, was 1.0
A thermosetting composition of about 2.0. 2. The thermosetting composition according to claim 1, wherein the hydrolyzable silyl group of the hydrolyzable silyl group-containing vinyl copolymer (B) is an alkoxysilyl group. 3. A curing catalyst (C) comprising an organotin compound, an acid phosphate, a reaction product of an acid phosphate and an amine, a saturated or unsaturated polycarboxylic acid or an acid anhydride thereof,
The thermosetting composition according to claim 1, which is a reactive silicon compound, an organic titanate compound, an organic aluminum compound or a mixture thereof.