JPH02103205A - Photocurable composition - Google Patents

Abstract

PURPOSE:To provide the title composition giving excellent photosensitivity and curing rate when subjected to rays of wide wavelength range including ultraviolet light and visible rays, comprising an ethylenic unsaturated double bond-contg. compound capable of addition polymerization and a specific photopolymerization initiator. CONSTITUTION:The objective composition comprising (A) an ethylenic unsaturated double bond-contg. compound capable of addition polymerization (e.g., 2- hydroxyethyl methacrylate) and (B) a photopolymerization initiator made up of (1) an alpha-diketone compound of the formula (R<1> and R<2> are each alkyl, alkoxy or aryl, but being not alkoxy at the same time) (e.g., benzil), (2) an oxidizing agent having a reduction potential greater than -0.30V vs. SCE (e. g., diphenyl iodonium) and (3) as promoter, such an amine that among the carbon-contg. groups linked to the N-atoms, at least one is methylene group.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a photocurable composition having excellent photosensitivity and curing speed to light in a wide wavelength range including ultraviolet rays and visible light.

(Prior art) Photopolymerizable compositions that are cured by light irradiation are used for various purposes.
For example, it is widely used in photoresists, inks, printing plates, etc. The photocurable composition basically contains an addition polymerizable compound having an ethylenically unsaturated double bond and a photopolymerization initiator.

(Problems to be Solved by the Invention) As a result of studies on improving photopolymerization initiators for the purpose of improving photosensitivity, ketals, benzoin ethers, acetophenones, etc. are currently commercially available as photopolymerization initiators. has been done.

Although these commercially available photopolymerization initiators have somewhat satisfactory performance, it is desired to increase the curing rate. Increasing the curing speed makes it possible to lower the output of the light source and speed up the work.

(Means for Solving the Problems) The present inventors conducted studies to improve the curing speed of photocurable compositions, and as a result, they came up with the present invention.

That is, the present invention provides a photocurable composition containing an addition polymerizable compound having an ethylenically unsaturated double bond and a photopolymerization initiator, wherein the photopolymerization initiator is (a) represented by the following general formula [1
] [In the formula, Rl and R1 each independently represent alkyl,
represents an alkoxy and aryl group, but R' and R'' must not be an alkoxy group at the same time.
- a diketone compound, (b) an oxidizing agent having a reduction potential greater than -0,30V vs, S CE, and (c) containing as promoter an amine in which at least one of the carbons bonded to the nitrogen atom is a methylene group. A photocurable composition is provided.

A compound represented by the above general formula [1] (hereinafter referred to as component (a)
). ), the alkyl group of R'SR'' usually has 1 to 4 carbon atoms, such as methyl group, ethyl group, propyl group, butyl group, etc. The substituent of the substituted alkyl group has 1 to 4 carbon atoms. 4 alkyl group,
It may be an alkoxy group having 1 to 3 carbon atoms (for example, methoxy and ethquine groups), a halogen atom (for example, chlorine and bromine), or the like. The alkoxy group has 1 to 3 carbon atoms as listed above.
Examples include: Substituents of the phenyl group, which may have substituents, include alkyl groups having 1 to 4 carbon atoms, 1 to 4 carbon atoms,
It may also be an alkoxy group of 3, a halogen atom, a nitro group, etc. R' and R2 must not be both alkoxy groups. When R' and R1 are both alkoxy groups, compound (1) becomes a diester and exhibits almost no ability to initiate photopolymerization.

Specific examples of the compound represented by the general formula [11] include benzyl, 4,4'-dimethoxybenzyl, l-phenyl-
Examples include 1,2-propanedione, methylbenzoyl formate, 2,3-butanedione, and the like.

The oxidizing agent which is the component (b) of the present invention has a voltage of 10.30V vs.

It has a reduction potential greater than SCE (closer to O), preferably -0,15 to -0, 30V vs. SCE. Oxidizing agents with a reduction potential smaller than -0, 30V vs, SCE (more distant from O) include methylene blue (-0,32V vs, SCE), and onium salts other than diaryliodonium salts include 4-diazodiphenylamino Sulfate (-1,28V vs, S CE
), triphenylsulfonium salt (-1,36V vs,
SCE), etc., but all of them lack oxidizing power and are ineffective. An oxidizing agent having a reduction potential greater than -0.15 Vv+s, SCE, has too strong oxidizing power, resulting in poor system stability. The reduction potential is basically determined by the document name "Journal of Chemical Society J (J, C, 5) 80.
Volume, 4269 pages (1958), [Journal of
Polymer Science J (J, Po1y, 5ci) 22
Vol. 73 (1984), “Photographic Science and Engineering J”
r, Sci, Eng,) vol. 14, p. 72 (197
0 Year XPhotogr, Sci, Eng,) Volume 18, 4
75 (1974), but those not listed are usually measured using acetonitrile as the solvent, tetra-n-butylammonium perchlorate as the supporting electrolyte, and 5CE (saturated calomel electrode) as the indicator electrode. do. Examples of compounds that satisfy the above reduction potential include the formula:
A diaryliodonium salt represented by is used.

In the above formula [11], the substituents R1i-R@ are each independently a hydrogen atom, a halogen atom (e.g., chlorine and bromine), a lower alkyl group (e.g., a methyl group, an ethyl group, a propyl group, and a t-butyl group). , a lower alkoxy group (e.g. methoxy group, ethoxy group, propoxy group) or a nitro group;
l2e, Bre, 1e), B “4@, PFt+”, As
You may also tear the Fee or Taha 5bFlle. General formula [■
] Compounds shown in [Journal of Polymer Science Polymer Symbodia J (J,
Polym, Sci, PolymSym,
), Vol. 56, pp. 383-395 (1976), for example, diphenyliodonium, bis(p-chlorophenyl)iodonium,
Examples include iodonium chlorides, bromides, borofluoride salts, hexafluorophosphate salts, hexafluoroarsenate salts, and hexafluorophosphate salts such as ditolyliodonium and bis(p-butylphenyl)iodonilla 11. .

Examples of amines in which at least one of the carbons bonded to the nitrogen atom is a methylene group (hereinafter sometimes referred to as component (c)) used in the present invention include triethylamine, N-methyldiethanolamine, triethanolamine, Examples include N-ethyl-N-hennoaniline, noethanolamine, N-phenylglycine, and benzyldimethylamine. In the present invention, this amine is believed to act as a polymerization initiation promoter.

The addition-polymerizable compound having an ethylenically unsaturated double bond used in the present invention is an ethylenically unsaturated double bond that is cured by addition polymerization under the action of a photopolymerization initiator and becomes substantially insolubilized. It is a compound with Examples of such compounds include unsaturated carboxylic acids such as acrylic acid and methacrylic acid, ethylene glycol, tetraethylene glycol, neopentyl glycol, propylene glycol, 1,2-butanediol, trimethylolpropane, pentaerythritol, and tripentyl glycol. Esters of polyhydroquine compounds such as erythritol and the above unsaturated carboxylic acids, trimedylolpropane borigrindyl ether, pentaerythritol polyclinonol ether,
Propylene glycol noclinodyl ether, epichlorohydrin and 2゜2-bis(4-hydroxyphenyl)
- reaction product with propane, addition reaction product of evoquinde with diglynodyl ester of phthalic acid and bipedally unsaturated carboxylic acid, acrylamide, ethylenebisacrylamide, ethylenehismethacrylamide, hexastyrenebisacrylamide, hexamethylene Examples include acrylamides and methacrylamides such as bismethacrylamide. Preferred are acrylic esters and methacrylic esters.

In the composition of the present invention, the ratio of the photopolymerization initiator and accelerator used is 0.01 to 0.3 mol of component (a) to 1 mol of the double bond-containing compound, preferably 0.025 to 0.02 mol.
2 mol, and component (b) in an amount of 0.01 to 0.2 mol, preferably 0.02 to 0. Imol, component (c) 0.00
5-0.5 mol, preferably 0.01-0.25 mol
It is l. When the amount of the photopolymerization initiator and accelerator is less than the above-mentioned amount, the photosensitivity decreases and the curing of the composition requires a long time. Moreover, if the amount is greater than the above upper limit, the strength and solvent solubility resistance of the formed film will be reduced.

The composition of the present invention comprises the above-mentioned double bond-containing compound and the components (
A photopolymerization initiator consisting of a combination of a), (b) and component (C) is an essential component, but other polymer components may be added as necessary, such as partially saponified polyhinyl acetate cellulose derivative, polyethylene oquinide. , sodium polyacrylate, polyamide, and the like may be added to the composition of the present invention. In addition, polyacrylic acid alkyl esters and acrylic acid alkyl esters are combined with acrylic acid, methacrylic acid, acrylonitrile, butadiene, styrene, etc.; , a copolymer with butadiene and styrene, etc. may be added.

Furthermore, if necessary, a polymerization inhibitor (e.g. 2.6 Note
-butyl-p-cresol, hydroquinone and p-
(methoquinophenol, etc.) may also be blended. The amount of the polymerization inhibitor to be blended is 0 to 5 parts by weight, preferably 0 to 2 parts by weight, per 100 parts by weight of the ethylenically unsaturated monomer.

The above-mentioned essential components and optional components are mixed by adding an appropriate liquid such as water or an organic solvent as necessary to obtain a photocurable composition.

The composition of the invention may be prepared in a conventional manner.

For example, the above-mentioned essential components and optional components may be used as is or in a solvent (e.g., methyl ethyl ketone,
Ketone solvents such as acetone and cyclohexanone,
Ester solvents such as ethyl acetate and butyl acetate, aromatic solvents such as toluene and xylene, cellosolve solvents such as methyl cellosolve, ethyl cellosolve and butyl cellosolve, alcohol solvents such as methanol, ethanol and propatool, tetrahydrofuran and dioxane, etc. (ether-based solvents) and mixing in a cool, dark place using, for example, a Ni-Goo or a mixer.

The photocurable composition obtained here can be used as it is or molded into any shape and used as UV curable ink, UV curable coating material, printing plate material, dry film resist, resist for microphosphorography, and the like.

As the exposure light source that can be applied to the photocurable composition of the present invention, general-purpose light sources such as high-pressure mercury lamps, medium-pressure mercury lamps, xenon lamps, and metal halide lamps may be used.

(Effects of the Invention) The photocurable composition of the present invention exhibits high sensitivity to light, particularly ultraviolet light, and has a fast curing speed.

(Example) The present invention will be explained in more detail with reference to Examples.

The invention is not limited to these examples.

Preparation of photocurable composition 0 Method A Ingredient (a
), (b) and (C) (the number of moles shown in Table 1) were dissolved to obtain a solution of a photocurable composition (photosensitive liquid-A).

0 Method B Components (a), (b) and (C) (the number of moles shown in Table 2) are dissolved in 2-hydroxypropyl methacrylate lQ and methyl ethyl ketone 250z12, and a solution of the photocurable composition (photosensitive liquid-B ) was obtained.

The components (a), (b) and (c) used are shown below.

Benzyl 4.4°-dimethoxybenzyl l-phenyl-1,2-propanedione methylbenzoyl formate 2.3-butanedione diphenyliodonium chloride (-0,20V vs, 5CE) b-2 diphenyliodonium tetrafluoroborate (-0 , 26V vs, 5CE) c-IN-methyljetanolamine Commercially available initiators for comparison, benzyl dimethyl ketal (Irgacure 651 manufactured by Ciba Geigy) and l
-Hydroxy-1-cyclohexylacetophenone (Irgacure 184 manufactured by Ciba Geigy) and component (b)
Methylene blue (-0,32V vs, 5CE
) and triphenylsulfonium hexafluoroantimonate (-1,36V vs, 5CE), the number of moles shown in Tables 1 and 2 was dissolved under the same conditions, respectively. Solutions (namely, photosensitive solutions -A and -B) were obtained.

Method A The photosensitive solution A39 was placed in an aluminum cylindrical can with a diameter of 55 mm and a depth of 7 R11, and light from an ultra-high pressure mercury lamp (3Kw) manufactured by Oak Seisakusho Co., Ltd. was irradiated vertically above the 60G scrap. After irradiation, a metal needle weighing 30 g and a diameter of 0,5*x at the tip was allowed to fall freely from the vertical direction law, and the irradiation time (seconds) until the tip no longer entered the cured film was measured.
This was used as an evaluation standard for photosensitivity.

Method B: Put the photosensitive liquid -889 into a hard glass bottle with a diameter of 23 x g, and irradiate it with light from a Toshiba high-pressure mercury lamp (400 W) from a horizontal direction of 18 cm. The increase in the viscosity of the liquid was measured, and the irradiation time until the viscosity of the photosensitive liquid reached 500 ps was measured, and this was used as an evaluation standard for photosensitivity.

As is clear from Comparative Examples 1 to 4 and 7 to 10, when any one of components (a) to (C) is absent in the photocurable composition, the photosensitivity is significantly reduced. Also, Comparative Example 5.6
．． As is clear from 11.12, the photocurable composition of the present invention has better photosensitivity than those using conventional commercially available initiators. Based on these facts, Nippon Paint Co., Ltd. is a patent distributor that features a photocurable composition that can be put to practical use in a variety of applications.

Claims (1)

[Scope of Claims] 1. A photocurable composition containing an addition-polymerizable compound having an ethylenically unsaturated double bond and a photopolymerization initiator, wherein the photopolymerization initiator has (a) the following general formula [I ] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [I] [R^1 and R^2 in the formula are each independently alkyl,
Although it represents an alkoxy and an aryl group, μm and R^1 must not be an alkoxy group at the same time. ], (b) -0.30Vvs. A photocurable composition comprising an oxidizing agent having a reduction potential greater than SCE, and (c) an amine in which at least one of the carbons bonded to a nitrogen atom is a methylene group as an accelerator.