JPS59230003A - Photo-polymerization initiator - Google Patents

Abstract

PURPOSE:To provide a photo-polymerization initiator composed of 2,4,5-triphenylimidazole dimer and an oxime ester, and capable of giving a photo-polymerized resin composition having excellent curability of the coating film and the adhesivity to the substrate. CONSTITUTION:The objective photo-polymerization initiator is obtained by mixing (A) 2,4,5-triphenylimidazole dimer and (B) an oxime ester {preferably a compound of formula [R1 and R2 are 1-10C alkyl, (un)substituted phenyl, naphtyl, anthryl, pyridyl or quinolyl wherein R1 and R2 together form a ring; R3 is 1-5C alkyl or (un)substituted phenyl], e.g. dimethylketone-O-acetyloxime, etc.} at a weight ratio (A/B) of 1/10-1/1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photopolymerization initiator, and specifically,
The present invention relates to a photopolymerization initiator used in a photopolymerizable resin composition in which only the exposed portion is cured by photopolymerization upon exposure to actinic rays and has excellent adhesion to a substrate.

Photopolymerizable resin compositions are used as actinic ray-curable inks, paints, or photoresists, but a major problem with these is the curability of the coating film upon exposure.

That is, the curability of the coating film is significantly affected by the thickness of the coating film. For example, in the case of photoresist or screen printing ink, the thickness of the coating film reaches 10 to 100 μm, which tends to result in poor curing of the inner surface of the coating film. Furthermore, when pigments or dyes are added to the photopolymerizable resin composition, this tendency is remarkable, and the expected curing performance does not appear, such as tack remaining on the surface of the coating film.

Attempts have been made to improve such curability problems by combining various photopolymerization initiators. For example, a combination of benzophenone or a derivative thereof and 4,4'-bis(diethylamino)benzophenone (Japanese Patent Publication No.
37902, Japanese Patent Publication No. 54-25943), and a combination of xanthone and 4,4-bis(dialkylamino)benzophenone (Japanese Patent Publication No. 52-92246).

However, although these photopolymerization initiators are effective, they tend to cause poor curing and poor adhesion to the substrate when the thickness of the coating exceeds 108 m, especially when dyes or pigments are added. , it still wasn't enough.

As a result of extensive studies to solve these problems, the present inventors have found that a coating solution can be achieved by using a mixture of 2.4.5-triphenylimidazole dimer and oxime ester as a photopolymerization initiator. It was discovered that a photopolymerizable composition having extremely excellent film curability and excellent adhesion to a substrate can be obtained, and the present invention was achieved.

That is, the present invention provides 2.4.5. - A photopolymerization initiator comprising a triphenylimidazole dimer and an oxime ester is provided.

The photopolymerization initiator of the present invention forms a photopolymerizable resin composition together with a photopolymerizable compound, a polymeric binder, or other additives, and will be specifically explained below, including these components.

The photopolymerizable compound for which the photopolymerization initiator of the present invention is suitably used is a photopolymerizable compound having one or more polymerizable double bonds in the molecule.

Examples of such compounds include styrenic compounds such as styrene, α-methylstyrene, and chlorostyrene;
Methyl (meth)acrylate, ethyl (meth)acrylate, roux and t-propyl (meth)acrylate,
'-Be(!- and t-)thyl(meth)acrylate-
Tetrahydrofurfuryl (meth)acrylate, 2
- Ethylhexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2uryl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, methoxyethyl (meth)acrylate, cyclohexyl (meth)acrylate, phenoxyethyl (meth)acrylate, ) Acrylate, methoxyethyl (meth)
Acrylate, ethoxyethyl (meth)acrylate,
-Functional (meth)acrylate compounds such as polyethylene glycol (meth-5 acrylate, polypropylene glycol (meth)acrylate, etc.), ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, etc. 'O-ru di(meth)acrylate, diglobylene glycol di(meth)acrylate, polyprolene glycol di(meth)acrylate,
Polyethylene glycol di(meth)acrylate, 1.
Trifunctional (4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate), 1,6-hexanediol di(meth)acrylate, etc.
meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)
Representative examples include trifunctional or higher functional (meth)acrylates such as acrylate and pentaerythritol tetra(meth)acrylate. These polymerizable compounds can be used alone or in combination, and are present in the photopolymerizable resin composition in an amount of 5 to 80% by weight, preferably 10 to 50% by weight.
used at a rate of

Examples of the polymer binder include polystyrene, polymethyl methacrylate, methyl methacrylate-ethyl acrylate copolymer, poly(meth)acrylic acid, styrene-(meth)acrylic acid copolymer, and (meth)acrylic acid-
Examples include methyl methacrylate copolymer, polyvinyl butyral, cellulose ester, polyacrylamide, and saturated polyester, which are selected depending on the purpose.

The 2.4.5-triph enylimidazole dimer of the present invention may have a substituent on each phenyl group, and those represented by the following general formula are preferred.

Although various forms of dimer bonding are possible, the form of the following general formula is preferable.

(General formula) [wherein R1 is hydrogen, 2-bromo, 2-chloro, 2-fluoro, 2-alkyl having 1 to 4 carbon atoms and 2,4-dichloro, R2 is hydrogen, 2-fluoro, -Bromo,
2-chloro, 2-fluoro, 4-chloro, 2-alkyl having 1 to 4 carbon atoms, 2-cyano and alkyl group being 2-alkoxy having 1 to 4 carbon atoms, R3 is hydrogen , 3.4-dimethoxy, 3.4-jethoxy, 2.3-dimethoxy, 2.4.6-)dimethoxy, 4-alkoxy and 3.4-methylenedi in which the alkyl group has 1 to 4 carbon atoms It's oxy. ] The oxime ester group of the present invention has the general formula R1-R
2 may be various organic compounds such as aromatic or aliphatic hydrocarbons or heterocyclic compounds, but preferred are the following (1) to (6).

That is, examples of R1 and R2 include the following (11 to (4)).

In this case, R1 and R11 may be the same or different.

(1) A linear or branched alkyl group having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms. (2) A substituted or unsubstituted phenyl group, naphthyl group, or anthryl group, with a substituent having 1 to 5 carbon atoms. ~10, preferably 1 to 5 linear or branched alkyl groups,
Alkoxyl group having 1 to 5 carbon atoms, halogen, amino group,
Dimethylamino group, diethylamino group, mercapto group, etc. (3) Pyridyl group such as 2-pyridyl group, quinolyl group such as 6-quinolyl group, or pyridyl group or quinolyl group having the same substituent as in (2) (4) Rt and R2
A fluorenyl group, etc., which are combined to form a ring, or (
The fluorenyl group having the same substituent as in 2).

Further, as R3, the following (5) to (6) are exemplified.

(5) Alkyl group having 1 to 5 carbon atoms such as methyl group, ethyl group, propyl group, t-propyl group, butyl group, t-butyl group, etc. 6) Phenyl group or substituted phenyl group, and the substituents are as described above. This is the same as the substituent shown in (2).

The oxime esters mentioned above include various ketone-0-acyl oximes, specifically dimethyl ketone-0-
Acetyloxime diethyl ketone-0-acetyloxime acetophenone-〇-acetyloxime acetophenone-O,-benzoyl oxime dimethyl-non-”
0” (p-methylbenzoyl)oxime p-methylacetophenone-〇-(p-)lylcarbonyl)oxime 9-anthrylmethylketone-〇-acetyloxime 2
-Naphthyl methyl ketone -0-benzoyloxime benzophenone -〇-acetyloxime benzophenone -〇-phenylacetyloxime benzophenone -〇-(p
-chlorobenzoyl)oxime p-dimethylaminoacetophenone -〇-acetyloxime p, p'-his(dimethylamino)benzophenone -〇-acetyloxime p,I/-his(diethylamino)benzophenone -〇-benzoyloxime fluorenone -〇- (p-Methylbenzoyl)oxime fluorenone-〇-acetyloxime 2-pyridylmethylketone-〇-acetyloxime d1
(2-pyridyl)ketone-0-acetyloxime 6-chyturylmethylketone-〇-ethylcarbonyloxime 6
-Quinolylphenylketone-〇-acetyloxime, etc.

These oxime esters or the aforementioned 2.4, S-
i) FW=-IL (=+y' 7 bottles) 1 bottle may be used in combination of two or more of each.

Furthermore, a known photosensitizer such as benzoin, pensoyl alkyl ether, benzone enone, benzyl, paraaminophenyl ketone, or a derivative thereof may be added to the photopolymerization initiator of the present invention.

2, 4 in the present invention. The ratio of the s-)riphenylimidazole dimer and oxime ester to be used is appropriately selected depending on the type thereof or the type of photopolymerizable compound, etc., but it is approximately 2,4゜5-triphenylimidazole in terms of weight ratio. Dimer/oxime ester = 1/10
They are used in a ratio of 0 to 10/1, preferably in a ratio of 1/10 to 1/1.

In addition, the mixing initiator of the present invention is a photopolymerizable composition (solid content)
It is used in a range of 01 to 20% by weight, preferably 1 to 10% by weight.

The photopolymerizable resin composition obtained according to the present invention is applied to a substrate by a known method, and then irradiated with actinic rays.
A photopolymerization reaction is induced.

The active light source used is a far ultraviolet light source (Hg-Xe lamp, low-pressure mercury lamp) that emits strong light at 200 to 300 nrn.
Examples include excimer lasers, Hg lamps, xenon lamps, and high-pressure mercury lamps having emission spectra of 3QQBm or more, as well as N2 lasers, argon lasers, He-Ne lasers, and the like.

Next, the present invention will be explained by examples.

Example polymethyl methacrylate (Sumipex-BH)
509 Trimethylolpropane triacrylate
25g Tet 2 ethylene glycol diacrylate
20. li+2.4.5-) Riphenylimidazole dimer 1.0g benzotriazole
o, zog leuco crystal violet 0.159N-
Methyljetanolamine O,0
,59 Victoria Blue
0.04p benzophenone-〇-acetyloxime 3.09 methyl ethyl ketone
After 1.37 g of the above composition was sufficiently mixed by mechanical stirring, it was coated on a copper plate to a thickness of 25 μm, and then dried at 75° C. for 5 minutes.

Next, step tablet (Fuji Fi1m 15
(stages) were stacked and irradiated with an ultra-high pressure mercury lamp (2M) for 10 seconds from a distance of 451 m. This was developed by washing out the unexposed areas with chlorocene.

As a result, a good image with up to 8 lines was produced.

Example 2゜Polymethyl methacrylate 5
0g trimethylolpropane triacrylate
45g2.4.5-) Riphenylimidazole dimer ogp-methylacetophenone-〇-acetyloxime 3.59benzotriazole
0.20g Victoria Blue
0.04p Methyl ethyl ketone 137g The above composition was coated, dried, exposed and developed in the same manner as in Example 1, and a good image of up to 9 stages was obtained.

Example 3 Trimethylolpropane triacrylate 4
0g2.4.5-) Riphenylimidazole dimer
1. Ogp-methylacetophenone-〇-acetyloxime 4.01! victoria blue
0.04p1.4-dioxa7
137 g of the above composition was coated, dried, and exposed in the same manner as in Example 1, and then developed with an IX sodium carbonate aqueous solution (40'C) to obtain a good image with up to 9 steps.

Example 4 Polymethyl methacrylate
50g trimethylolpropane triacrylate)
40. p2,4.5-triphenylimidazole dimer 1.5g Victoria Blue
0, o4g Methyl ethyl ketone 13711 When the above composition was coated, dried, exposed and developed in the same manner as in Example 1,
Good images up to 9 steps were obtained.

Example 5 The composition of Example 2 was applied to a thickness of 5 μm on a copper plate, dried, and then covered with a chrome mask (made of quartz) and heated at 500 W.
When the film was irradiated with a Hg-Xe lamp (manufactured by Ushio Inc.) and developed with chlorocene, a good image of up to 5 μm was obtained.

Comparative Example 1゜Polymethyl methacrylate
50g trimethylolpropane triacrylate
45g benzophenone-〇-acetyloxime
s,oy benzotriazole
0.20g Victoria Blue
0.04,9 Methyl ethyl ketone 137I When the above composition was treated in the same manner as in Example 1, even after 60 seconds of irradiation,
Most of the area was washed out like the unexposed area and no image was formed.

patent applicant Daicel Chemical Industries, Ltd.

Claims (2)

[Claims] (1) 2.4.57) A photopolymerization initiator consisting of a liphenylimidazole dimer and an oxime ester. (2) The photopolymerization initiator according to claim 1, wherein the oxime ester is represented by the following general formula. (General formula) In the formula, & and R2 may be the same or different, and have a carbon number of 1
~10 alkyl groups, substituted or substituted phenyl groups,
It is a naphthyl group, anthryl group, pyridyl group or quinolyl group, and R3 represents an alkyl group having 1 to 5 carbon atoms or a substituted or unsubstituted phenyl group.0(3)
The photopolymerization initiator according to claim 2, wherein R1 and R2 form a ring.