JPS6399201A - Photopolymerization initiator - Google Patents

Abstract

PURPOSE:To obtain a photopolymerization initiator showing high photopolymerization ratio, capable of improving physical properties, solvent resistance, etc., of prepared polymer, consisting of an S-phenyl thiobenzoate derivative. CONSTITUTION:An S-phenyl derivative shown by formula I (R1 is H, alkyl, halogen, benzoyl or acetyl; R2, R3 and R4 are H, alkyl or halogen) is used as a photopolymerization initiator. The compound shown by formula I, for example, can be obtained by reacting a compound shown by formula I with a compound shown by formula II and triphenylphosphine in the presence of a solvent such as anhydrous acetonitrile, etc., under heating. 100pts.wt. ethylenic unsaturated double bond-containing compound [e.g. methyl acrylate, propylenebis(methacrylamide), etc.] is blended with usually 0.5-5pts.wt. of the photopolymerization initiator to give a photopolymerization composition. The composition is useful as print plate making material, ultraviolet-curing coating component, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Needle I!P) The present invention relates to a novel photopolymerization initiator and a photopolymerizable composition containing the same.

(Prior Art) Photopolymerizable compositions have the property of polymerizing and faecesizing when irradiated with light and becoming insoluble in water or various solvents, so they are used as printing plate-making materials such as resin letterpress plates and lithographic printing plates. It is widely used in dry film resists, microlithography resists, UV curing paints, UV curing inks, etc. These photopolymerizable compositions are obtained by combining a photopolymerization initiator and a polymerizable monomer.

(Problems to be Solved by the Invention) An issue to be solved in order to obtain a photopolymerizable composition with high practical value is to improve the photopolymerization yield. In order to solve this problem, various approaches can be considered, but it is suitable to improve the photopolymerization yield by improving the performance of the photopolymerization initiator.

(Means for solving the problem) S-phenyl thiobenzoate derivatives and/or photopolymerization initiators exhibiting a higher photopolymerization yield than conventional photopolymerization initiators.
Alternatively, the problem is to be solved by a photopolymerizable composition containing the same.

That is, the gist of the present invention is ^ 1 < 2 In the formula 5, RI is hydrogen, an alkyl group (preferably a carbon number of 1
~20) represents a halogen, a benzoyl group or an acetyl group, and R2, Ro and R4 are the same or different and represent hydrogen, an alkyl group (preferably having 1 to 20 carbon atoms) or a halogen. ] A photopolymerization initiator is provided.

The present invention also provides a photopolymerizable composition comprising a combination of the photopolymerization initiator and a compound having at least 1 gI of ethylenically unsaturated double bonds.

The photopolymerization initiator (1) of the present invention is usually obtained according to the following reaction formula: [In the formula, R8-R4 have the same meanings as above, and Ph represents a phenyl group. ] Of course, the reaction is not limited to the above reaction.

The reaction is carried out in the presence of a solvent and under heating. Anhydrous acetonitrile is suitable as the solvent. The obtained product is separated and purified by an appropriate method.

The photopolymerization initiator of the present invention is blended with a known compound having at least one ethylenically unsaturated double bond to form a photopolymerizable composition.

Examples of compounds having at least one ethylenically unsaturated double bond include methyl acrylate, ethyl acrylate, n-propyl acrylate, β-hydroxyethyl acrylate, β-hydroxypropyl acrylate, polyethylene glycol monoacrylate, polypropylene glycol monoacrylate, phenyl Diethylene glycol monoacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, methoxypolyethylene glycol monoacrylate, ethoxypolyethylene glycol monoacrylate,
Glycerol diacrylate, pentaerythritol diacrylate, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, methyl methacrylate, ethyl acrylate, n-propyl methacrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl methacrylate, polyethylene glycol monomethacrylate, polypropylene Glycol monomethacrylate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, methoxypolyethylene glycol monomethacrylate, ethoxypolyethylene glycol monomethacrylate, glycerol dimethacrylate, pentaerythritol dimethacrylate, trimethylolpropane trimethacrylate, tetramethylolmethanetetramethacrylate, acrylamide, N - medirollacrylamide, n-butoxymethylacrylamide, isobutoxyacrylamide, n-p~butylacrylamide,
Methylenebis(acrylamide), ethylenebis(acrylamide), propylenebis(acrylamide), methacrylamide, N-methylolmethacrylamide, n
-butoxymethylmethacrylamide, isobutoxymethacrylamide, n-p-butylmethacrylamide, methylenebis(methacrylamide), ethylenebis(methacrylamide), propylenebis(methacrylamide), and the like.

The proportion of the photopolymerization initiator used in the photopolymerizable composition of the present invention is 0.1 to 20 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the ethylenically unsaturated monomer. . If it is less than 0.1 part by weight, photocuring will not be sufficient, and if it exceeds 20 parts by weight, the polymer will have an apparent upper molecular weight, resulting in disadvantages such as not being able to obtain sufficient hardness. .

In addition to the above essential components, other polymer components may be added as necessary.
For example, partially saponified polyvinyl acetate cellulose derivatives, polyethylene oxide, sodium polyacrylate, polyamides, etc. may be added to the composition of the invention. moreover,
Polyacrylic acid alkyl ester, copolymer of acrylic acid alkyl ester and acrylic acid, methacrylic acid, acrylonitrile, butadiene, styrene, etc.; polymethacrylic acid alkyl ester, copolymer of methacrylic acid alkyl ester and acrylic acid, methacrylic acid, acrylonitrile, butadiene, A copolymer with styrene or the like may also be added.

These polymer components are contained in an amount of 0 to 1000 parts by weight, preferably 0 to 100 parts by weight of the ethylenically unsaturated monomer.
~200 parts by weight.

Furthermore, if necessary, a polymerization inhibitor (e.g. 2,6-jet
-butyl-p-cresol, hydroquinone, p-methoxyphenol), dyes (for example, rose bengal, eosin, methylene blue, malachite green), etc. may be blended. The blending amount of the polymerization inhibitor is 0 to 5 parts by weight, preferably 0 to 2 parts by weight, based on 100 parts by weight of the above ethylenically unsaturated monomer, and the blending amount of the dye or pigment is 0 to 50 parts by weight, preferably It is 0 to 20 parts by weight.

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 photopolymerizable composition.

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

As an exposure light source that can be applied to the photopolymerizable 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 can be used.

Note that JP-A-60-70444 proposes a ketone compound having a sulfonyl group that releases free radicals when irradiated with light, but the purpose of this is to obtain colored images and to improve productivity. is irrelevant.

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

Synthesis example 1 Benzoic acid I in a dry 50 mQ eggplant flask.

224! (0.01 mol), diphenyl disulfide 2°189 (0.01 mol), and triphenylphosphine 2°629 (0.01 mol) were added in this order, followed by 20 mQ of anhydrous acetonitrile. Insert a magnetic stirrer, attach a reflux condenser with a calcium chloride drying tube, and stir and reflux all day and night on an oil bath. After the reaction, the solvent of the human part was distilled off under reduced pressure, and chloroform 5xQ was added and dissolved.
Add a small amount of silica gel (approximately 2 g). Chloroform was distilled off from the mixture under reduced pressure and adsorbed onto Mysilica gel. The silica gel adsorption phase was placed on a silica gel column (diameter 2CIX length 25cm), and petroleum ether (bp 40-60℃) was added.
Develop with a mixed solvent of ethyl ether (95:5). First, thiophenol and unreacted disulfide are distilled off, followed by unreacted triphenylphosphine. At this point, the proportion of ethyl ether is gradually increased to 15% and a fraction of the product is separated. The solvent is distilled off under reduced pressure to obtain phenylthiol benzoate. The product was S-phenyl thiobenzoate [yield t, 03y (48% of theory), mp 52-54°C]. NMRCCDCQ
2. δ): 8.0 to 7.9 (m.

2H), 7.5-7.2 (m, 8H) Synthesis Example 2 In the same manner as in Synthesis Example 1, 4-bromobenzoic acid 2°029(
0.01mol, diphenyl disulfide 2゜189(
0.01mol), triphenylphosphine 2゜62g
(0.01 mol) was used to produce 4-bromothio-cheap S-phenyl phosphate [Yield Ei 10.46 g (16% of theory), melting point 96-98°C]. NMR (CDCQ
3, δ) + 7, 65 (dd, 4 If), 7.
35 (bs, 5 Synthesis Example 3 3.4-dichlorobenzoic acid 1.9 in the same manner as Synthesis Example 1)
2g (0.01 mol), diphenyl disulfide 2.
181? (0.01 mol), triphenylphosphine 2. S-phenyl 3,4-dichlorothiobenzoate was produced using G29 (0.01 mol) [yield 1°5
0g (', 53% of theory), melting point 88-9.1'C]
.

NMR (CDC(!3.δ): 8.0-7.53(m
,3■),7,liO(bs,5F-1) Synthesis Example 4 4-benzoylbenzoic acid 2.26 was prepared in the same manner as in Synthesis Example I.
g (0.01 mol), diphenyl disulfide 2.1
8g (0.01mol), triphenylphosphine 2
, 629 (0.01 mol) was used to produce S-phenyl 4-benzoylthiobenzoate [Collection ff11. of
3 g (33% of theory), melting point tot, o~I O2,
5℃]. N M n (CD CQ 3.δ); 7.
9 (dd, 41-D, 7.7Cm, 2H), 7.48
(m, 3H), 7.38 (bs.

5t() Synthesis example 5 In the same manner as in Synthesis Example 1, 4-acetyl ammonium, nitric acid! .

64g (0.01mol), diphenyl disulfide 2
S-phenyl 4-acetylthiobenzoate was produced using 18 g (0.01 mol) of triphenylphosphine and 2.62 g (0.01 mol) of triphenylphosphine [yield 10.99
(35% of theoretical value), melting point 114.5-115.5t. NMR (CDCQ3.δ); 7, 95 (bs,
4 H), 7.45 (bs, 5H), 2.60 (s,
3H) Synthesis Example 6 In the same manner as in Synthesis Example 1, 1.22 g of benzoic acid (0, Olm
ol), bis(4-octylphenyl) disulfide 4
．． 42 g (0.01 mol) and triphenylphosphine 2.62 g (0.01 mol) were used to produce 4-octylphenylthiobenzoate [Yield: 11.31 g
('40% of theory), melting point 43-44°C]. NMR (
CDCffs, δ); 0,9(t,3H), 1.2~
1.8 (m.

120), 2.64 (t, 2T, I), 7.2-7.6
(m.

7tl), s, o(a, 2rO Examples 1 to 5) For each compound obtained in Synthesis Examples 1 to 5, 5× 10-2mo110
．． A solution was prepared. Next, 3.02 ml of this solution was placed in each cylindrical metal container (vertical i15, 5 cm),
(Irradiate light with a 3KW high-pressure mercury lamp from a distance of 30cm. Lightly press the surface of the object to be irradiated with a spaticle of width 7x, w, and wait for 71111 seconds until no trace remains (time required for EI conversion). The results are shown in Table 1.

Table 1 Koi Koi 1 Using 4-n-octylphenylthiobenzoate obtained in Synthesis Example 6, the curing time was measured in the same manner as in Examples 1 to 5, and it was 60 seconds. Note that the cured product was cloudy.

Example 7 Curing time was measured in the same manner as Examples 1 to 5 using 4-n-butylphenylthiobenzoate, and the result was 60
It was seconds.

Example 8 Phenyldiethylene glycol monoacrylate (manufactured by Toagosei Co., Ltd., trade name Aroex M-101) 2.0+
Dissolve σ in benzene lx (!) and dissolve the compound obtained in Synthesis Example 4 in this to obtain lx 10-'mat of this compound.
/C solution was obtained. Next, this solution was placed in a Pyrex irradiation tube and irradiated with light for 3 minutes using a Nori-Go-Rand light irradiator using a 300W mercury lamp.

After light irradiation, the cured product was washed with methanol and vacuum dried, and then the weight of the cured product was measured to determine the yield. Light irradiation was performed for 6 minutes, 10 minutes, 15 minutes, and 20 minutes in the same manner, and the yield was determined. The results are shown in FIG. 1 by points Δ. Furthermore, the results obtained when benzoin monomethyl ether, a commercially available photopolymerization initiator, was used under the same conditions are also shown at one point in FIG.

As is clear from FIG. 1, the compound obtained in Synthesis Example 4 according to the present invention has a sensitivity equivalent to that of a commercially available photoinitiator,
It can be seen that the photopolymerization yield is even higher.

(Effects of the Invention) The photopolymerization initiator of the present invention has a sensitivity equal to or higher than that of commercially available initiators, and exhibits a high photopolymerization yield. Therefore, it is possible to improve the physical properties, solvent resistance, etc. of the obtained polymer.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the results of Example 8, and shows the results of Synthesis Example 4.
The results for the compound are shown below, and the results for the commercially available benzoin monomethyl ether compound are shown below.

Claims (1)

[Claims] 1. General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (I) [In the formula, R_1 represents hydrogen, an alkyl group, a halogen, a benzoyl group, or an acetyl group, and R_2, R_3 and R_4 are Same or different and represent hydrogen, alkyl group or halogen. ] A photopolymerization initiator represented by: 2. The photopolymerization initiator according to item 1, wherein the halogen is chlorine or bromine. 3. (a) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (I) [In the formula, R_1 represents hydrogen, an alkyl group, a halogen, a benzoyl group, or an acetyl group, and R_2, R_3, and R_4 are the same or different. represents hydrogen, an alkyl group, or a halogen. ]; and (b) a photopolymerizable composition containing a compound having at least one ethylenically unsaturated double bond. 4. The photopolymerizable composition according to item 3, wherein the halogen of the photopolymerization initiator (a) is chlorine or bromine.