JPH0128060B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a photocurable resin composition that is easily cured by light and capable of forming a coating film on materials etc. that has excellent adhesion to metals and has excellent flexibility, flexibility, and impact resistance. . It is a well-known fact that epoxy resins containing tar have been used to prevent corrosion inside pipes such as iron pipes and corrosion on ship bottoms. However, from the standpoint of pollution, it is not desirable to include tar, and new iron coating materials are being developed to replace this. Among them,
Conventionally known epoxy resins and acrylic acid (or methacrylic acid) reaction products are effective materials, and their cured coatings are highly crosslinked, so
Although it has excellent hardness and chemical resistance, it is hard, has low elongation, lacks flexibility, and has poor adhesion to metals. Epoxy resins and acrylic acid (or methacrylic acid) reaction products have insufficient properties to replace tar-containing epoxy resins, due to thin coatings and curing damage caused by oxygen in the air. ing. On the other hand, in order to impart flexibility to the resin, methods are used in which liquid polybutadiene is blended or reacted and incorporated into the main chain. A method in which the resin obtained by such a method is cured by redox polymerization has the disadvantage of poor surface drying properties. In addition, in photocuring methods that use light, electron beams, etc., surface drying properties are poor;
The surface is sticky, and although it has excellent impact resistance and adhesion due to the use of polybutadiene resin, the crosslinking density is low, resulting in poor coating film properties, especially chemical resistance and solvent resistance. It has drawbacks. As a result of various studies, the present inventors found that in a polymerizable ester resin in which a polybutadiene resin having a carboxyl group at the end is incorporated into the main chain of an epoxy resin or a monobasic unsaturated carboxylic acid reaction product, the secondary By curing a resin in which maleic anhydride is added to the OH group of the It has been found that a film can be obtained. The present invention forms a coating film that is easily cured by light, has excellent adhesion to materials, especially metals, has excellent surface drying properties, flexibility, and flexibility, and has excellent impact resistance, chemical resistance, and solvent resistance. The epoxy resin and the polybutadiene resin having a carboxyl group at the terminal are mixed in such a way that the carboxyl group of the polybutadiene resin is 0.1 to 0.9 per chemical equivalent of the epoxy group of the epoxy resin. In a polymerizable ester resin obtained by reacting in a chemical equivalent ratio and then reacting with a monobasic unsaturated carboxylic acid in an approximately equivalent chemical equivalent to the chemical equivalent of the remaining epoxy group, the secondary 0.5 to 0.01 maleic anhydride per chemical equivalent of OH group
The present invention relates to a photocurable resin composition obtained by blending a polymerizable monomer and a photosensitizer with a polymerizable ester resin obtained by chemical equivalent reaction. In the present invention, the epoxy resin and the polybutadiene resin having a terminal carboxyl group are mixed in such a way that the carboxyl group of the polybutadiene resin having a terminal carboxyl group is 0.1 to 0.9 chemical equivalents, preferably 0.2 to 0.9 chemical equivalent of the epoxy group of the epoxy resin.
Preferably reaction temperature 120 ~ 0.8 chemical equivalent ratio
2 to 180℃, more preferably 130 to 160℃
An addition reaction is carried out for 5 hours to obtain an epoxy group-containing polyester resin. If the carboxyl group exceeds 0.9 chemical equivalent, the strength of the coating film will be weak, and if it is less than 0.1 chemical equivalent, the adhesion to metal and flexibility will decrease, making it impossible to achieve the object of the present invention. Further, although this reaction proceeds without a catalyst, the reaction may be carried out with the addition of a catalyst. Examples of the catalyst include triethylamine, dimethylbenzylamine, sodium benzoate, sodium p-toluenesulfonate, etc., and the amount added is preferably 0.01 to 0.5% by weight based on the epoxy resin and the above-mentioned polybutadiene resin. The epoxy resin used in the present invention is preferably a bisphenol A type epoxy resin, such as Epicote 828, 1001, 1004, 1007 (trade name manufactured by Ciel Chemical Co., Ltd.), DER331, 661, 664 (trade name manufactured by Dow Chemical Company), etc. be. In addition, alicyclic epoxy resins, novolak epoxy resins, aliphatic epoxy resins, etc. can also be used, and these epoxy resins may be used alone or in combination. Examples of polybutadiene resins having carboxyl groups at the terminals include C-1000, C-2000 (trade name manufactured by Nippon Soda), CTB2000×162, CTB2000×156,
CTBN1300×15, CTBN1300×8, CTBN1300
Examples include ×13 (product name manufactured by Ube Industries). In addition, a polybutadiene resin having a carboxyl group at the terminal, which is obtained by esterifying a terminal hydroxy polybutadiene resin by reacting an excessive amount of a saturated or unsaturated dibasic acid, can also be used. Next, to the epoxy group-containing polyester resin,
Approximately equivalent chemical equivalents of a monobasic unsaturated carboxylic acid such as acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, or sorbic acid are added to the remaining epoxy groups to form an epoxy group-containing polyester resin and a monobasic unsaturated carboxylic acid. 0.01 to 1% by weight of triethylamine, tributylamine, benzylmethylamine, trimethylbenzylammonium chloride, etc. as a catalyst, and 0.001% of hydroquinone, hydroquinone monomethyl ether, paratertiary butylcatechol, etc. as a polymerization inhibitor.
Add ~0.1% by weight and react at 80~110°C for 6~15 hours, preferably when the acid value becomes 50 or less,
0.1 to 0.01 chemical equivalent of maleic anhydride is reacted with 1 chemical equivalent of secondary OH group in the resin produced, and when the value reaches 1/2 or less of the theoretical acid value of the added maleic anhydride, the end point is A polymerizable ester resin is obtained. When the amount of maleic anhydride exceeds 0.5 chemical equivalent, the polymerizable ester resin becomes gel-like. Furthermore, if the amount is less than 0.01 chemical equivalent, the chemical resistance and solvent resistance of the coating film will be poor.
In the polymerizable ester resin obtained in this way,
Preferably, 20 to 60% by weight of a polymerizable monomer and 0.5 to 5% by weight of a photosensitizer are blended with respect to the polymerizable ester resin to obtain a photocurable resin composition. In the present invention, a polymerizable monomer refers to a monomer that has the property of copolymerizing with a polymerizable ester resin when exposed to light, such as methyl methacrylate, 2-hydroxyethyl methacrylate, ethylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, and ethyl acrylate. , acrylates and methacrylates such as 2-hydroxyethyl acrylate, ethylene glycol diacrylate, 1,6-hexanediol acrylate, trimethylolpropane triacrylate, styrene, vinyltoluene, divinylbenzene, β-
Refers to vinyl compounds such as chlorostyrene, vinyl acetate, and vinyl propionate. Examples of photosensitizers include benzoin, benzoin ethyl ether, benzoin isopropyl ether, benzophenone, benzyl, and peroxides. Tertiary amines such as triethanolamine and Michler's ketone can also be used as sensitizing aids. Note that a radical initiator can also be added to the photocurable resin composition according to the present invention. The amount of the radical initiator added is 0.5 to 5% by weight, preferably 1 to 3% by weight, based on the polymerizable ester resin and the polymerizable monomer. If it exceeds 5% by weight, the pot life will be shortened and it will be difficult to use. Examples of radical initiators include acyl peroxides such as benzoyl peroxide and acetyl peroxide, hydroperoxides such as tertiary butyl peroxide and kyumene hydroperoxide, ketone peroxides such as methyl ethyl ketone peroxide, and ditertiary butyl peroxide. Oxyperoxide such as oxide is used. In addition, when using a radical initiator, iron, cobalt,
Naphthenates, octenoates, etc. of metals such as lead, manganese, nickel, tin, and zinc can be used in combination. The amount added is 0.5 to 5% by weight based on the polymerizable ester resin and polymerizable monomer, preferably,
The content is 1 to 3% by weight. In the present invention, materials other than those mentioned above may be mixed. Such materials include fillers and reinforcing materials such as aluminum hydroxide, calcium carbonate, silicon dioxide, antimony trioxide, hexabromobenzene, alumina, glass fiber, and organic fiber. The photocurable resin composition of the present invention is a composition that is easily cured by light and has excellent adhesion to metals, impact resistance, chemical resistance, solvent resistance, and drying properties of the coating surface. The photocurable resin composition of the present invention is cured by irradiation with a commercially available high-pressure mercury lamp. At this time, there is no need to heat it. Examples of the present invention will be described. Parts are by weight. Example Production of Resin Composition A A reaction flask equipped with a stirrer, a thermometer, and a reflux condenser was charged with Epikote 828 (epoxy equivalent: 198,
192 parts (1 equivalent) (manufactured by Ciel Chemical Co., Ltd.) and 260 parts (0.4 equivalent) of a polybutadiene resin having a carboxyl group at the terminal, trade name C-1000 (manufactured by Nippon Soda), and heated to 150°C.
The mixture was reacted for 3 hours to obtain an epoxy group-containing polyester resin. This acid value was 0.5. After cooling the above epoxy group-containing polyester resin, 47 parts (0.55 equivalents) of methacrylic acid, 0.5 parts of hydroquinone, and 1.5 parts of triethylamine were added to it, and the temperature
When the acid value reached 5 after reacting at 100℃ for 8 hours,
Add 4.9 parts (0.1 equivalent) of maleic anhydride and reduce the temperature
React at 100℃ for 1 hour (end point at acid value 10 or less)
A polymerizable ester resin was obtained. Styrene was added as a polymerizable monomer to the above polymerizable ester resin in an amount of 30% by weight based on the polymerizable ester resin, and benzoin ethyl ether was added as a photosensitizer in an amount of 3% by weight based on the polymerizable ester resin and styrene. A curable resin composition A was obtained. Production of resin composition B Using the synthesis equipment of resin composition A, Epicoat
192 parts (1 equivalent) of 828 and 260 parts (0.4 equivalent) of C-1000 were charged and reacted at 150°C for 3 hours to obtain an epoxy group-containing polyester resin. This acid value is
It was 0.5. After cooling the above epoxy group-containing polyester resin, 47 parts (0.55 equivalents) of methacrylic acid, 0.5 parts of hydroquinone, and 1.5 parts of triethylamine were added thereto and reacted at a temperature of 100°C for 8 hours until the acid value reached 5. was set as the end point, and a polymerizable ester resin was obtained. Add styrene as a polymerizable monomer to the above polymerizable ester resin at 30% by weight based on the polymerizable ester resin.
and benzoin ethyl ether as a photosensitizer to polymerizable ester resin and styrene.
A photocurable resin composition B was obtained by adding and mixing in weight%. Resin composition A and resin composition B were each applied to a zinc phosphate-treated steel plate (0.8 x 70 x 150 mm) with a bar coater #28 to a cured film thickness of 50μ, and a 2KW high-pressure mercury lamp (product name H2000L/4, Toshiba Electric Materials Co., Ltd.) was used. (manufactured by),
It was irradiated with light at an irradiation distance of 10 cm to cure it, and its properties were measured. The results are shown in Table 1.

[Table] The results in Table 1 show that the resin composition of the present invention has excellent alkali resistance and acetone resistance without decreasing impact resistance. Production of resin composition C Using the synthesis apparatus of Example 1, 96 parts (0.5 equivalent) of Epicote 828 (epoxy equivalent: 198, Shell Chemical),
240 parts (0.5 equivalent) of Epikote 1001 (epoxy equivalent: 480, manufactured by Ciel Chemical Co., Ltd.) and 260 parts (0.4 equivalent) of C-1000 were charged and reacted at 150° C. for 3 hours to obtain an epoxy group-containing polyester resin. This acid value is 0.3
It was hot. After cooling the above epoxy group-containing polyester resin, add 47 parts (0.55 equivalents) of methacrylic acid, 0.5 parts of hydroquinone, and triethylamine.
Add 1.5 parts of maleic anhydride and react for 8 hours at 100°C, and when the acid value reaches 5, 4.9 parts of maleic anhydride (0.1 equivalent)
was added, and the reaction was carried out at a temperature of 100℃ for 1 hour (acid value
(end point: 10 or less) A polymerizable ester resin was obtained. Add styrene as a polymerizable monomer to the above polymerizable ester resin at 30% by weight based on the polymerizable ester resin.
and benzoin ethyl ether as a photosensitizer to polymerizable ester resin and styrene.
A photocurable resin composition C was obtained by adding and mixing in weight%. Production of Resin Composition D Using the synthesis apparatus of Example 1, 96 parts (0.5 equivalent) of Epicote 828 (epoxy equivalent: 198, Shell Chemical),
Epicote 1001 (epoxy equivalent 480, Ciel Chemical)
240 parts (0.5 equivalent) and 260 parts (0.4 equivalent) of C-1000 were charged and reacted at 150°C for 3 hours to obtain an epoxy group-containing polyester resin. The acid value was 0.3. After cooling the above epoxy group-containing polyester resin, 47 parts (0.55 equivalents) of methacrylic acid was added to it.
0.5 parts of hydroquinone and 1.5 parts of triethylamine were added, and the reaction was carried out at a temperature of 100° C. for 8 hours, and the end point was reached when the acid value reached 5, to obtain a polymerizable ester resin. Add styrene as a polymerizable monomer to the above polymerizable ester resin at 30% by weight based on the polymerizable ester resin.
A photocurable resin composition D was obtained by adding and mixing 3% by weight of benzoin ethyl ether as a photosensitizer to the polymerizable ester resin and styrene. Resin composition C and resin composition D were each applied to a zinc phosphate-treated steel plate (0.8 x 70 x 150 mm) with a bar coater #28 to a cured film thickness of 50μ, and a 2KW high-pressure mercury lamp (product name H2000L/4, Toshiba Electric Materials Co., Ltd.) was used. (manufactured by),
It was irradiated with light at an irradiation distance of 10 cm to cure it, and its properties were measured. The results are shown in Table 2.

[Table] *, **, *** are the same as Table 1. The results in Table 2 show that the resin composition of the present invention has excellent alkali resistance and acetone resistance without decreasing impact resistance. .

Claims (1)

[Claims] 1. An epoxy resin and a polybutadiene resin having a terminal carboxyl group are reacted at a ratio of 0.1 to 0.9 chemical equivalents of the carboxyl group of the polybutadiene resin per 1 chemical equivalent of epoxy group of the epoxy resin, and then the remaining epoxy In a polymerizable ester resin obtained by reacting approximately the same chemical equivalent of monobasic unsaturated carboxylic acid with respect to the chemical equivalent of the group, maleic anhydride A photocurable resin composition comprising a polymerizable ester resin obtained by reacting 0.5 to 0.01 chemical equivalents of a polymerizable monomer and a photosensitizer.