JPS5946546B2 - Photocurable resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photocurable resin composition useful as a coating composition that cures quickly, provides a coating film with excellent appearance, adhesion, heat resistance, etc., and has good hardness.

Conventionally, photocurable compositions mainly contain acrylates such as epoxy acrylate, epoxy methacrylate, and polyester acrylate, unsaturated polyester, and the like as main components. However, acrylates have particularly poor adhesion to metals, and unsaturated polyester resins have particularly poor heat resistance and are intended for limited practical use. The present invention improves these drawbacks, and provides a composition that not only has better heat resistance and adhesion than both of the above-mentioned photocurable compositions using acrylates and unsaturated polyesters, but also has better other properties. The present invention provides a photocurable resin composition from which a coating film can be obtained. That is,
The present invention is characterized in that (2 to 10 mol% of maleic anhydride is added to the unsaturated epoxy ester resin, which is an addition reaction product of A polyepoxide and α/β monounsaturated acid, based on the hydroxyl groups of the unsaturated epoxy ester resin). The resin obtained by the reaction (Resin)
Average molecular weight per polymerizable double bond is 450-13
00 halogen-free unsaturated polyester resin and (O photosensitizer), (A and (B) are (AA publication, weight ratio 90/1).
0 to 50,150.

Component (A) used in the present invention is obtained by adding 2 to 10 mol % of anhydrous maI/inic acid to the hydroxyl group of an unsaturated epoxy ester resin.

The reason for limiting maleic anhydride to 2 to 10 mol% is 2.
If it is less than mol%, the characteristics of the present invention cannot be fully exhibited, and if it exceeds 10 mol%, gelation tends to occur during the reaction between the unsaturated epoxy ester resin and maleic anhydride. In the present invention, by modifying the unsaturated epoxy ester resin with maleic anhydride, the coating film obtained from the photocurable resin composition of the present invention has excellent properties such as heat resistance and adhesion, as well as good hardness. It is something that you have.

The unsaturated epoxy ester resin used in the present invention is obtained by addition reaction of polyepoxide and α/β monounsaturated acid, and the polyepoxide and α/β monounsaturated acid have equivalent amounts of epoxy groups and carboxyl groups Preferably, the ratio is 1 or approximately 1.

The reaction is carried out, for example, at 80 to 120°C in the presence of a polymerization inhibitor and a polymerization initiator. The above-mentioned polyepoxide is a compound containing one or more, preferably two or more, epoxy groups per molecule, such as glycidyl polyether of polyhydric alcohol or polyhydric phenol, epoxidized fatty acid or drying oil acid, epoxidized georefin,
Epoxidized diunsaturated acid esters are used, and oligomers thereof are also used. In addition, as α/β monounsaturated acids, α. β-unsaturated monobasic acids are preferred, and α·β monounsaturated dibasic acids are preferably used in an amount of 10 mol % or less of the unsaturated acids. Part of the α/β monounsaturated acid may be replaced with a saturated polybasic acid. Examples of saturated polybasic acids include phthalic anhydride, tetrahydrophthalic anhydride, and pyromellitic anhydride. Examples of addition catalysts include metal halides such as zinc chloride and lithium chloride, dimethyl sulfide,
Sulfides such as methylphenyl sulfide, sulfoxides such as dimethyl sulfoxide and methyl ethyl sulfoxide, tertiary amines such as N-N dimethylaniline, pyridine, triethylamine, benzyldimethylamine, and their hydrochlorides or bromates, tetramethylammonium chloride , quaternary ammonium salts such as towamethyldodecylbenzyl ammonium chloride, sulfonic acids such as para-toluenesulfonic acid, and mercaptans such as ethyl mercaptan and propyl mercaptan.

Examples of polymerization inhibitors include hydroquinone, tert-butylcatechol, p-benzoquinone, and 2,5-diterbutylhydroquinone.

The unsaturated polyester resin used as component (B) used in the present invention has an average molecular weight of 4 per polymerizable double bond.
50 to 1300 resins are used. Polymerizable double bond 1
If the average molecular weight per unit is less than 450, the crosslinking density will be excessive and the adhesion will be reduced, and if it exceeds 1,300, the crosslinking density will be small and a tough film will not be obtained, which is not preferred in practice. Component (g) according to the present invention comprises a polymerizable unsaturated polybasic acid, a polyhydric alcohol, and optionally a saturated polybasic acid,
Obtained by condensation reaction with monobasic acid etc. Unsaturated polybasic acid components include polymerizable unsaturated acids such as alpha- and beta-monounsaturated dibasic acids such as maleic anhydride, fumaric acid, itaconic acid, and citraconic acid, and saturated polybasic acids include phthalic anhydride. There are non-polymerizable unsaturated acids such as isophthalic acid, terephthalic acid, hexahydrophthalic acid, adipic acid, sebacic acid, succinic acid, tetrahydrophthalic acid, and endomethylenetetrahydrophthalic acid.As monobasic acids, These include benzoic acid, synchropentanenyl monomaleate, and soybean oil fatty acids. In addition, polyhydric alcohol components include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, glycerin, trimethylolpropane, pentaerythritol, hydrogenated bis Phenol etc. are used. The acid component and the alcohol component preferably have a total number of carboxyl groups/total number of hydroxy groups of 1/1 to 1/1.2, and the reaction is performed, for example, by heating to 150 to 250°C in an inert gas atmosphere to generate condensed low molecules. This is done while removing things. During the reaction, it is preferable to add hydroquinone, p-tertiarybutylcatechol, or the like as an antioxidant.
When the prisoner component of the present invention is applied alone to a photocurable coating,
Although the coating surface is severely wrinkled and cannot be put to practical use, if an appropriate amount of unsaturated polyester is used in combination as component (B), the coating surface becomes smooth and at the same time, toughness is obtained.

The reason why the weight ratio of (A)/(B) is limited to 90/10 to 50/50 is that if it exceeds 90/10, the above characteristics will not be improved. Further, if the ratio is less than 50/50, the curability becomes poor and the toughness of the film cannot be obtained, which is not preferable. CA)/
(B is preferably blended in a weight ratio of 80/20 to 60/40. (.A) component according to the present invention and (
For practical purposes, it is preferable that the system in which the components B) are combined be dissolved in a reactive monomer.

Reactive monomers include styrene, vinyltoluene, α-
Methylstyrene, divinylbenzene, diallyl phthalate, acrylic acid or methacrylic esters (2-hydroxyethyl acrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, polyethylene glycol diacrylate, etc.)
, etc. may be used alone or in combination of two or more.
The amount of reactive monomer is 0.0% based on the total weight of (A) and (B).
It is preferably used in a range of 5 to 5 times, particularly 1 to 3 times. When it is less than 0.5 times, the viscosity of the resulting photocurable resin composition tends to increase, and when it exceeds 5 times, the final coating film obtained becomes brittle.

(The zero-component photosensitizers include benzoin, benzoin alkyl ethers such as benzoin ethyl ether, benzoin isopropyl ether, benzoin phenyl ether, benzointhioethers, benzophenone,
2-ethylanthraquinone, decyl chloride, etc. can be used for acetophenol.

The amount used is preferably 0.5 to 10% by weight, particularly 1 to 5% by weight, based on all polymerizable components [total amount of (self), (B) and, if necessary, reactive monomers]. If it is less than 0.5% by weight, the curing speed will be slow, and if it exceeds 10% by weight, it will tend to be difficult to form a film.

Note that a radical initiator can be added to the photocurable resin composition according to the present invention. This allows, for example, when the composition is applied to a workpiece with a complex shape, and therefore, even if there are parts where light does not pass through or is insufficiently transmitted, curing of such parts is accelerated. be able to.
However, in this case, it is cured by heating. The amount of the radical initiator added is 0.5 to 5% by weight based on the total polymerizable components.
Particularly preferred is 1 to 3% by weight. 5% by weight, there is a risk that the composition will gel during storage.

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 cyclohexanone peroxide, and ditertiary peroxides. Oxyperoxides such as butyl peroxide and dicumyl peroxide are used. In addition, when using a radical initiator, iron, cobalt, lead,
Naphthenates, octenoates, etc. of metals such as manganese, nickel, tin, and zinc can be used in combination. The amount used is preferably 0.5 to 5% by weight, particularly 1 to 3% by weight. ``In the present invention, other materials than those mentioned above may be mixed.

Such materials include fillers and reinforcing materials such as aluminum hydroxide, calcium carbonate, silicon dioxide, alumina, glass fibers, and organic fibers. Example 1 570 parts of epoxy resin Epicoat 828 (epoxy equivalent: 192) manufactured by Shell Chemical, USA, 260 parts of methacrylic acid, 3 parts of benzyldimethylamine, and 0.06 part of hydroquinone were charged and reacted at 105° C. for 6 hours.

The acid value at that time was 2. To this, maleic anhydride 1
5 parts were added and reacted at the same temperature for 3 hours, and the acid value of the reaction product was 13. 40 parts of styrene was added to 60 parts of this resin to obtain a resin liquid, which was used as component (A). Further, 29.4 parts of maleic anhydride, 134 parts of dipropylene glycol, and 102 parts of adipic acid were added and reacted at 220°C until the acid value reached 20 to obtain a reaction product with an average molecular weight of 783 per polymerizable double bond. Ta.

40 parts of styrene was added to 60 parts of this reaction product to obtain a resin liquid, which was used as component (B). Next, 20 parts of the resin solution of component (B) and 3 parts of benzoin ethyl ether as a photosensitizer were added to 80 parts of the resin solution of component (4) to obtain a photocurable resin composition. This is zinc phosphate treated steel plate (0.8
x 70 x 150 mm) using bar coater #28 (cured film thickness, 35 to 40 μm), and irradiated with light using a 2 KW mercury lamp at an irradiation distance of 10 crrL to measure the curing characteristics.
The results are shown in Table 1. Example 2 340 parts of epoxy resin Epicoat 828 (epoxy equivalent: 192) manufactured by Ciel Chemical, 340 parts of Epicoat 1001 (epoxy equivalent: 481), 215 parts of methacrylic acid, 3 parts of benzyldimethylamine, and 0.06 part of hydroquinone were charged and heated at 105°C. The reaction was allowed to proceed for 6 hours.

The acid value at that time was 3.5. 15 parts of maleic anhydride was added to this and reacted at the same temperature for 3 hours, and the acid value of the reaction product was 15. 40 parts of styrene was added to 60 parts of this resin to obtain a resin liquid, which was used as component (4). Also, (B)
Using the same resin as in Example 1 as the component resin liquid, the curing characteristics after light irradiation were measured using the same treatment method as in Example 1.

The results are shown in Table 1. Comparative Example 1 3 parts of benzoin ethyl ether was added as a photosensitizer to 100 parts of the resin liquid of the prisoner component obtained in Example 1, and the curing characteristics of the coating film after irradiation with light were evaluated using the same treatment method as in Example below. was measured.

The results are shown in Table 1. Comparative Example 2 3 parts of benzoin ethyl ether was added as a photosensitizer to 100 parts of the resin solution of component (B) obtained in Example 1, and the curing characteristics after light irradiation were evaluated using the same treatment method as in Example 1. It was measured.

The results are shown in Table 1. Comparative Example 3 A 60% styrene solution of commercially available epoxy dimethacrylate (bisphenol A type epoxy system) was prepared, and 3 parts of benzoin ethyl ether was added as a photosensitizer to 100 parts of this resin solution. Using the same treatment method, the curing characteristics were measured after light irradiation.

The results are shown in Table 1. Comparative Example 4 570 parts of epoxy resin Epicoat 828 (epoxy equivalent: 192) manufactured by Shell Chemical, USA, 260 parts of methacrylic acid, 3 parts of benzyldimethylamine, and 0.0 parts of hydroquinone.
6 parts were charged and reacted at 105°C for 6 hours.

Add 40 parts of styrene to 60 parts of this resin to obtain a resin liquid,
(A) Component. The procedure of Example 1 was followed except that this component (4) was used. Comparative Example 5 53.9 parts of maleic anhydride, 1 part of dipropylene glycol
34 parts and 65.8 parts of adipic acid at 220°C with an acid value of 2.
The reaction was carried out to obtain a reaction product having an average molecular weight of 414 per polymerizable double bond.

40 parts of styrene was added to 60 parts of this reaction product to obtain Jugetsugoya. This resin liquid was designated as component (B).

The procedure of Example 1 was followed except that this component (B) was used. Example 3 In Example 1, (adipic acid 1 which is the raw material for component B)
The procedure of Example 1 was repeated except that 103.6 parts of phthalic anhydride was used instead of 2 parts of phthalic anhydride.

In Example 3, the molecular weight per polymerizable double bond of the unsaturated polyester obtained was 788. Comparative Example 6 In Example 1, 200 parts of tetrachlorophthalic anhydride was used instead of 102 parts of adipic acid, which is the raw material for component (B).
The procedure of Example 1 was followed except that 1.

In addition, in Comparative Example 6, the molecular weight per polymerizable double bond of the unsaturated polyester obtained was 1109. In Example 3 and Comparative Examples 4 to 6, the curing characteristics were measured in the same manner as in Example 1. The results are shown in Table 2.

The coating composition according to the invention has high toughness (tensile, elongation),
It exhibits excellent properties such as adhesion to metals and heat resistance,
In addition to ordinary coating materials, it can be applied to a wide range of heat-resistant materials.

Claims (1)

[Scope of Claims] 1 (A) An unsaturated epoxy ester resin which is an addition reaction product of a polyepoxide and an α/β-unsaturated acid has 2 to 10
Resin obtained by reacting mol% of maleic anhydride, (
B) Average molecular weight per polymerizable double bond is 450~
1300 halogen-free unsaturated polyester resin and (C) a photosensitizer, (A) and (B) have a weight ratio of (A)/(B) of 90/10 to 50/50. A photocurable resin composition comprising: