JPS5974103A - Ultraviolet ray-curable resin composition - Google Patents

Abstract

PURPOSE:The titled composition which is stable to natural light but cures rapidly upon irradiation with ultraviolet rays, prepared by adding a specified sensitizer to a cation-polymerizable compound to which an aromatic quinone compound has been added as a polymerization catalyst. CONSTITUTION:As a sensitizer (promotor) is used an aromatic quinone compound of formula I or II, wherein R1, R2, R3, and R4 are each a 1-4C alkyl, phenyl or phenoxy, a halogen, nitro, or cyano, and (R1 and R2) or (R3 and R4) may be combined together to form an aromatic ring. Namely, a cation-polymerizable compound (e.g., novolak epoxy resin) is mixed with an aromatic iodinium salt (e.g., diphenyliodinium tetraborate) and about 0.01-5wt%, based on the total composition, above aromatic quinone compound.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention exhibits pseudo-storage stability under natural light and
The present invention relates to an ultraviolet curable resin composition that can be rapidly cured by irradiation with ultraviolet light of 0 Dnm or less.

In general, epoxy resins have good adhesion to substrates and have well-balanced properties. General Electric Co. and others have developed photodegradable aromatic onium salts as catalysts that enable photocuring of such epoxy resins. Patent applications (Japanese Patent Publication No. 50-151997, Japanese Patent Publication No. 52-14278) have been filed.

However, the manufacturing cost of the aromatic onium salt is very high, and in order to obtain the practically required curing speed, it is necessary to add several percent (by weight, the same shall apply hereinafter) or more of the onium salt, and the The manufacturing cost is also very high. Furthermore, if the amount of aromatic onium salt added is 1 to 2% or less, the curing speed becomes extremely slow, and a long period of ultraviolet irradiation is required to obtain a sufficiently cured product.

For the above reasons, the uses of ultraviolet curable epoxy resins containing only the aromatic onium salt are extremely limited due to cost issues.

The present inventors have conducted extensive research into photosensitizers for efficiently photodegrading aromatic iodonium salts in order to improve the above-mentioned drawbacks and to produce UV-curable resin compositions that cure rapidly at low cost. The results showed that aromatic quinone compounds such as anthraquinone and β-naphthoquinone are excellent sensitizers for aromatic iodonium salts, and that the addition of the aromatic quinone compounds improves the curing speed of resin compositions by ultraviolet irradiation. I discovered that scales can dramatically improve

That is, by adding the aromatic quinone compound, a resin composition having a practically sufficient ultraviolet curing speed can be obtained even when the amount of aromatic iodonium salt added is 1 to 2% or less.

The present invention comprises (a) one or more cationic polymerizable compounds, (b) an aromatic iodonium salt as a polymerization catalyst, (c) a sensitizer used as a co-catalyst, and one or more compounds belonging to the series consisting of aromatic quinone compounds. The present invention relates to an ultraviolet curable resin composition that is stable under natural light and rapidly cures under ultraviolet irradiation.

The cationic capacity compound used in the composition of the present invention is an oxygen- or sulfur-containing saturated double violet ring compound (especially 6.
oxirane compounds such as ethylene oxide, propylene oxide, epichlorohydrin, styrene oxide, phenyl glycidyl ether or butyl glycidyl ether, trioxane, 1,6-dioxolane or 1.3 .6- Cyclic acetal compounds such as trioxa-cyclooctane, β-propiolactone, ε-
Examples include cyclic lactone compounds such as caprolactone or their alkyl derivatives, chetane compounds such as ethylene sulfide, 1,2-propylene sulfide or thioepichlorohydrin, chetane compounds such as 1,6-propylene sulfide or 3,5-dimethyl chetane, etc. It will be done. Further, other cationically polymerizable compounds used in the compositions of the present invention include ethylenically unsaturated compounds that can be polymerized by a cationic mechanism, such as isobutylene,
- mono- or diolefin compounds such as octene, butadiene or isoprene, vinyl ether compounds such as vinyl methyl ether, vinyl isobutyl ether or ethylene glycol dihinyl ether, vinyl X ster compounds such as vinyl acetate or vinyl stearate, N-vinyl Examples include N-vinyl compounds such as pyrrolidone or N-vinylcarbazole, styrene, allylbenzene, or vinylcyclohexane.

Among the above-mentioned cationically polymerizable compounds, important compounds which are particularly frequently used are epoxy compounds used as epoxy resins, especially compounds having mono-, di- or poly-epoxy groups.

These epoxy compounds are usually cured at room temperature or under heat using a curing agent such as amine, phenol, carboxylic acid or dicarboxylic anhydride, but when using the catalyst system of the present invention, the curing agent may be used. It can be optically cured as a one-component system without any additives.

If desired, curing can also be carried out photochemically using a curing agent other than amines. Epoxy compounds used for this purpose may have two or more oxirane rings in one molecule, and bisphenol A epoxy resins, novolac epoxy resins, alicyclic epoxy resins, epoxidized polybutadiene, and the like are preferred.

As a bisphenol type epoxy resin, Epicor) 8
28, Epineat 864, Epicote 866, Epicote 1001, Epinea) 1004, Epicote 1
007 (above, oil-based shell epoxy ■i), DKR
331, DER5 Otsu 2, DKR661, DKR664
, DFjR667 (manufactured by Dow Chemical Company), Araldite 260, Araldite 280, Araldite 60
71, Araldite 6084, Araldite) 609
7 (all manufactured by Ciba Geigy), etc.

As a novolac type epoxy resin, Epicoat 152,
Epiny) 154 (manufactured by Yuka Shell Epoxy Corporation), Araldite EPN 1138, Araldite EPN 1139, Araldite EON 1235, Araldite Ealq 1273, Araldite EaN1
280, Araldite BON 1299 (manufactured by Ciba Geigy), DEN 451, DEN 43B
(all manufactured by Dow Chemical Company), etc.

The ring type epoxy tree H is aY 175, ay
177, CY 179, OY 184, OY 192
(all manufactured by Ciba Geigy), etc.

EPB 12B is the epoxidized polybutadiene.

Examples include Epn27 (manufactured by Nippon Soda).

The various epoxy resins mentioned above may be used alone or as a mixture. It is also possible to use a monofunctional epoxy compound within a range where the properties of the cured product of the epoxy resin do not deteriorate significantly.

Examples of monofunctional engineered poxy compounds include phenylquinosidyl ether, t-butylphenylglycidyl ether,
Examples include neopentyl glycidyl ether, p-oxybenzoic acid glycidyl ester, m-propenylphenyl glycidyl ether, and glycidyl methacrylate.

The composition of the present invention using one or a mixture of the above epoxy compounds can be polymerized by irradiation with ultraviolet light.

The aromatic iodonium salt used in the present invention is ultraviolet rays (wavelength 3
It is a known compound that releases a Lewis acid and initiates cationic polymerization upon irradiation with a wavelength of 00 nm or less.

Examples of the aromatic iodonium salts include those described in the Journal of the American Chemical Society (
J, Am, Ohem, Soc,) 752705
342 (1959), etc., and the anions of these a-donium salts include complex halide anions, such as BF2-1P'F6"-1sbo16-1AsF6
-, Fe074-, etc. are preferred.

The aromatic iodonium salt has the general formula (I); CArx-
NiAr2]" [MQnl-(I) (wherein Ar or Ar a is a phenyl group, a naphthyl group, an alkyl group having 1 to 8 carbon atoms, a phenyl group, a phenoxy group, a halogen atom, a nitro group, or a carbon atom, respectively. Refers to a phenyl group substituted with one or more alkoxy groups having 1 to 5 atoms, Ar and Ar2 may be the same or different, and M is BlP, ke, Sb, Sn, Bi and Fe. Q represents a fluorine or chlorine atom, and n represents a number 1 greater than the valence of M.

Among the aromatic iodonium salts represented by the general formula (I), preferred ones are Ar□, Ara represents a phenyl group or tosyl group, and [MQ]- represents BF-1
14 of anions such as PF-1ABF-1SbF6-
6 Six things shall be hailed.

Examples of the compound represented by the general formula (I) include diphenyliodonium tetrafluoroborate, diphenyliodonium hexafluorophosphate, di(p-)lyl)-iodonium hexafluoroarsenate, di(4-nitrophenyl)-iodonium pentane Fluorostanate, di(4-t-butylphenyl)-iodonium hexafluorostibiate, di-2
- naphthyruiodonium tetrafluoroborate,
Di(4-diphenyl)-iodonium hexafluorophosphate, di(6-medoxyphenyl)-iodonium hexafluoroarsenate, phenyl-naphthyl-iodonium tetrafluoroborate, phenyl-4-fluorophenyl-iodonium hexafluorophosphate or phenyl -(6,5-diisopropylphenyl)-iodonium bentafluorosta 4
- etc.

The aromatic iodonium salt alone dissolved in a cationically polymerizable compound can also undergo a polymerization reaction by irradiation with ultraviolet rays. However, since these aromatic iodonium salts have an absorption band in the short wavelength region (wavelength 500 nm or less), ordinary ultraviolet light sources such as high-pressure mercury lamps, medium-pressure mercury lamps, low-pressure mercury lamps, xenon lamps, carbon lamps, arc lamps, etc. are used. In this case, the photolysis efficiency is very low, and the absorption band of the cationic polymerizable compound often overlaps with the absorption band of the cationically polymerizable compound, making the effect even worse.

Therefore, if only aromatic iodonium salt is added, the curing speed is very slow, and it takes a very long time to cure the hard coating on the back side of the coating.In practice, the amount of aromatic iodonium salt added is The effect will not be observed unless it is reduced to ~20%. Moreover, since the manufacturing cost of the aromatic iodonium salt is very high, the manufacturing cost of the clothing composition is also very high, which limits the range of use.

However, by adding one or more compounds belonging to the group consisting of aromatic quinone compounds used in the present invention as a sensitizer, the photosensitive region of the resin composition can be expanded to about 400 nm, and thus the curing speed can be significantly improved. . Therefore, in the present invention, when the amount of aromatic iodonium salt added is in the range of 0.1 to 5%, practically sufficient ultraviolet curability can be obtained.

The aromatic quinone compound used as the sensitizer used in the present invention has the general formula (■): or the general formula (■): 3 (wherein, R, R2, R3, and R4 are hydrogen atoms, and have 1 to 1 carbon atoms. 4, an aromatic ring is formed by any one of the alkyl group, phenyl group, phenoxy group, halogen atom, nitro group, cyan group, or a combination of R, R2 or R3, and R4, and the aromatic ring is a benzene ring. or a naphthalene ring, which may be substituted with one or more alkyl groups having 1 to 4 carbon atoms, phenyl groups, phenoxy groups, hydroxyl groups, halogen atoms, nitro groups, or cyano groups. It is a compound.

The aromatic quinine compounds are known compounds that are used as triplet sensitizers in various photoreactions and as dehydrogenation reagents in photochemical reactions, and are published, for example, in the Journal of the Chemical Society (T.
Ohem, Soc, X 1951) 1664, (1953) 3405, etc. However, when combined with the aromatic iodonium salt as in the present invention, the curing speed is significantly improved by ultraviolet irradiation compared to the case of using only the iodonium salt, and the curing reaction does not proceed under natural light, making it stable. Can be stored.

Examples of the aromatic quinone compounds include benzoquinones such as p-benzoquinone, chloranil, 1,2-benzoquinone, and tetrachloro-1,2-benzoquinone, or derivatives thereof, naphthoquinone, 1,2-naphthoquinone, and hijiroxina 7-toquinone. , 6,4-dichloro-1,2
- Naphthoquinones such as 7-enanthraquinone or their derivatives, anthraquinone, 7-enanthraquinone, 2-methylanthraquinone, and the like.

Among the aromatic quinones, naphthoquinones, anthraquinones, and phenanthraquinones are particularly preferred and effective. is 0.05~
It is desirable to add 0.5%.

The compositions according to the invention may contain the usual additives known in the art of curable resin compositions, such as pigments, dyes, fillers, reinforcing materials, glass fibers, flame retardants, antistatic agents, plasticizers, thixotropic agents or It is also possible to further contain an anti-cissing agent or the like.

When curing the ultraviolet curable resin composition according to the present invention, ultraviolet rays in the wavelength range of 250 to 400 nm are the most efficient. Therefore, the light source can be a low-pressure mercury lamp, medium-pressure mercury lamp, high-pressure mercury lamp, or xenon lamp. , a carbon arc lamp, etc., and can also be cured by irradiation with an electron beam.

Examples of applications in which the ultraviolet curable resin composition of the present invention is used include protective films, decorative films, insulating films, printing inks, marking inks, sealants, adhesives, photoresists, and laminates. It will be done.

Next, the composition of the present invention will be explained in more detail using Examples and Comparative Examples, but the present invention is not limited only to these Examples.

Examples 1 to 4 and Comparative Example 1 1 part of 4,4-dimethyldiphenyliodonium hexafluorophosphate was added to 100 parts (parts by weight, the same applies hereinafter) of epoxy-novolac resin (manufactured by Dow Chemical Company, trade name DEN 431). A resin composition was prepared by adding 0.3 part of the aromatic quinone compound listed in Table 1 to the dissolved solution.

The resin composition was coated on an aluminum plate using a bar coater for 10 minutes.
It was coated to a thickness of 0 μm, irradiated with ultraviolet rays, and the curing speed was measured.

The measurement results are shown in Table 1.

The conditions for ultraviolet irradiation were as follows: Mitsubishi Electric High Pressure Mercury Lamp H25-'OVA was used as the light source, irradiation distance was 15 cm, and moving speed was 12 m/min.

The curing rate is the number of irradiations required until the surface of the film becomes non-adhesive under the above-mentioned ultraviolet irradiation conditions, and one time of ultraviolet irradiation corresponded to an irradiation time rate of 0.25 seconds.

After the UV irradiation, only the surface layer of the coating film was non-adhesive.

Table 1 Examples 5 to 8 and Comparative Example 2 A resin composition was prepared in the same manner as in Example 1, coated on an aluminum plate, and irradiated with ultraviolet rays five times at a moving speed of 4 m/min. The coatings to which the aromatic quinone compound was added were completely cured to the back surface in all cases, and the surface hardness was 5H on a pencil hardness. was uncured.

The results are shown in Table 2.

Table 2 Agent: Shin Kuzuno (1 person)

Claims (5)

[Claims] (1) (a) one or more cationically polymerizable compounds, (b) an aromatic iodonium salt as a polymerization catalyst, (c) one or more compounds belonging to the series of aromatic quinone compounds as a sensitizer used as a co-catalyst; An ultraviolet curable resin composition that is stable under natural light and rapidly cures under ultraviolet irradiation. (2) Component (a) is an epoxy compound, a mixture of an epoxy compound and another cationic polymerizable compound, or a mixture of two or more epoxy compounds (
The composition described in item 1). (3) The component (b) has the general formula (I): [MQrX)-(I) (in the formula, Ar or A
r2 is phenyl substituted with one or more of a phenyl group, a naphthyl group, an alkyl group having 1 to 8 carbon atoms, a phenyl group, a phenoxy group, a halogen atom, a nitro group, or an alkoxy group having 1 to 5 carbon atoms, respectively; Hail to the group, A
r engineering, Ar 2 can be the same or different <, M
represents a metal or metalloid atom selected from the group consisting of BlP, AS, Sb, Sn, Bi and Fe, Q represents a fluorine or chlorine atom, and n is a number 1 greater than the valence of M. The composition according to claim 1, which is an aromatic iodonium salt prepared by: (4) The above component (c) has the general formula (■): or the general formula (
III) 3 (wherein, R, R8, R3, R4 are any one of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group, a phenoxy group, a halogen atom, a nitro group, a cyan group, or RR or a combination of R3 and R4 gives an aromatic 12 ring, and these aromatic rings are an alkyl group having 1 to 4 carbon atoms, a phenyl group, a phenoxy group, a halogen atom,
The composition according to claim 1, which is an aromatic quinone compound (optionally substituted with one or more hydroxyl group, nitro group, or cyano group). (5) The composition according to claim (4), wherein the aromatic ring is a benzene ring or a naphthalene ring.