JPH045180B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel photosensitive resin composition, and more specifically, to a highly sensitive photosensitive resin composition suitable for making relief plates. In recent years, the development of photosensitive resins for use in printing plates has become active, and various resin plates have been developed for use in newspapers, newspapers, etc.
Their use is also increasing in many printing fields such as cardboard, flexible packaging, foam, and books. By the way, printing using plates is roughly divided into three types depending on the plate type: letterpress, lithography, and intaglio printing.Among these, letterpress printing is widely used in the above-mentioned printing field. As the name letterpress suggests, the plate material used for printing has a relief in the part where the ink is transferred to the paper, and in order to create a letterpress using photosensitive resin, active light is used. It is necessary to photocure a predetermined portion of the photosensitive resin layer corresponding to the relief. In this case, it goes without saying that the smaller the cured area is, such as the highlight part of a halftone dot in a photograph or the fine dot part, or the thicker the photocured layer, the longer the exposure time will be. On the other hand, recently, as photosensitive resin plates have come into full-scale use in the printing field as described above, there has been a strong demand for improved productivity in the production of the resin plates. Therefore, in order to meet this demand, measures have been taken mainly in exposure equipment, such as using more powerful light sources or increasing the area that can be exposed at one time. Equipment measures lead to high costs, and such measures alone are insufficient, and there is a strong demand for improving the sensitivity of the photosensitive resin itself. Conventionally, sensitivity adjustment of photosensitive resins, particularly photosensitive resins used for making relief plates, has been mainly carried out by using a combination of a photopolymerization initiator and a photosensitizer. However, this method cannot reach a sensitivity level that fully satisfies the above requirements. For example, 2,2-dimethoxy-2-phenylacetophenone (also known as 2-methoxybenzoin methyl ether), which is commonly used in photosensitive resin compositions for use in this field, is the most photosensitive among benzoins and acetophenones. Although it has the highest sensitivity and excellent storage stability as a polymerization initiator, its performance is insufficient to meet the above requirements. Furthermore, it is known that the sensitivity of a photosensitive resin composition can be increased by using a trivalent organic phosphorus compound in combination with such a photopolymerization initiator (Japanese Patent Publication No. 18913/1983). This composition has the disadvantage that sensitivity tends to decrease during storage and is difficult to use. Furthermore, in fields other than relief plate making, many photopolymerization initiators and sensitizer systems have been proposed for curing thin films such as UV inks and UV-enhanced paints containing photosensitive resins. (Japanese Unexamined Patent Publication No. 56-82802). however,
All of these have too strong light absorption by themselves and act as internal filters, so although they are suitable for forming thin films of 50 μm or less, they are generally unsuitable for making relief plates. In view of these circumstances, the present inventors have conducted intensive research to provide a photosensitive resin composition that has excellent storage stability and high sensitivity and is suitable for making relief plates. We discovered that a composition containing an ethylenically unsaturated monomer, a photopolymerization initiator, a certain compound, and a thermal polymerization inhibitor in an ethylenically addition-polymerizable prepolymer could achieve this purpose. Based on this, the present invention has been completed. That is, the present invention includes (A) a polyoxyethylene segment in the molecule, the average molecular weight of the segment is 500 or more, and it accounts for 5% of the total molecular weight.
At least one prepolymer selected from unsaturated polyurethane and unsaturated polyester having ethylenically addition polymerizable properties, (B) ethylenically unsaturated monomer, (C) photopolymerization initiator, (D) General formula [In the formula, X ₁ is a hydrogen atom, a hydroxyl group, or -OR ₁ group (however, R ₁ is an alkyl group or an aralkyl group having 1 to 10 carbon atoms), X ₂ is a hydrogen atom,
5 alkyl group or -OR ₁ group (however, R ₁ has the same meaning as above), at least one of R ₂ and R ₃ is an alkyl group having 1 to 5 carbon atoms, and the rest are hydrogen atoms] and (E) a thermal polymerization inhibitor. The ethylenic addition-polymerizable prepolymer used as component (A) in the composition of the present invention is a polyoxygenate having an average molecular weight of 500 or more and accounting for 5% or more of the molecular weight of the prepolymer in one molecule of the prepolymer. It has an ethylene segment. Examples of the ethylenic addition polymerizable prepolymer include those selected from the aforementioned unsaturated polyurethanes and unsaturated polyesters having polyoxyethylene segments. The polyoxyethylene segment in the ethylenic addition polymerizable prepolymer may be present as one block in the prepolymer, or may be divided into several small blocks. , its total average molecular weight is determined from the viewpoint of improving sensitivity.
500 or more, and the ratio must be 5% or more based on the molecular weight of the prepolymer. If the average molecular weight is less than 500 or the ratio is less than 5%, the desired high sensitivity cannot be achieved and it is inappropriate. In addition, when the polyoxyethylene segment is made into small blocks and the total average molecular weight is set to 500 or more and 5% or more with respect to the prepolymer,
The average molecular weight of one small block is 300 or more, preferably 400 or more. Therefore, when forming small blocks, it is necessary to adjust the prepolymer production stage so that a plurality of small blocks are contained in one molecule of the prepolymer. For example, in the case of unsaturated urethane prepolymers, this can be easily achieved by chain extension, and in the case of unsaturated polyester prepolymers, this can be achieved by adjusting the molar ratio and acid value of the diol containing the segment in the diol component as specified. It can be easily adjusted by setting. Introduction of this polyoxyethylene segment into the prepolymer can be easily accomplished as described above by known methods. For example, if the prepolymer is an unsaturated polyurethane type,
Diol with an average molecular weight of 600 is
When using the above polyethylene glycol, ethylene oxide-propylene oxide copolymer (average molecular weight of polyoxyethylene segment part: 600 or more), etc. in combination with other diols or alone, or when using polyethylene glycol with an average molecular weight of less than 500, The chain may be extended by urethane bonds, ester bonds, etc. so that the total average molecular weight of the segments in the prepolymer is 500 or more. Here, the following can be exemplified as other diols that can be used in combination with the above diol, namely:
Examples of relatively low molecular weight diols include ethylene glycol, propylene glycol, propanediol, neopentyl glycol, and 1,6-
Mention may be made of linear alkylene diols having up to 20 carbon atoms, such as hexanediol and 1,3-butylene glycol. Examples of polymer diols include polyoxypropylene glycol, poly-1,4-oxybutylene glycol,
In addition to polyether diols such as polyepichlorohydrin and polylactones such as poly-ε-caprolactone and polyvalerolactone obtained by ring-opening polymerization of lactones using ethylene glycol as an initiator, aliphatic glycols and aliphatic dicarbons are also available. Examples include polyester diols such as polyethylene diadipate, polypropylene adipate, polybutylene adipate, polyethylene succinate, and polyhexamethylene adipate, which are acid condensates. In the case of the above-mentioned polyester diol, part of the dicarboxylic acid may be substituted with an unsaturated carboxylic acid such as maleic anhydride or fumaric acid, or an aromatic acid such as phthalic anhydride, isophthalic acid, or terephthalic acid, within a range that does not impair physical properties. It can also be used in place of carboxylic acid. In addition, various known diisocyanates can be used as the diisocyanate compound,
These materials may be used alone or in combination of two or more for the purpose of adjusting physical properties. Examples of such diisocyanate compounds include 2,4-tolylene diisocyanate, 2,6
-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 1,3-dimethylphenyl-2,4-diisocyanate, 1,3-dimethylphenyl-4,6
-diisocyanate, 1,4-dimethylphenyl-2,5-diisocyanate, 1-chlorophenyl-2,4-diisocyanate, 4,4'-diphenyl diisocyanate, 3,3'-dimethyl -4,
4'-diphenyl diisocyanate, 2,4'-diphenyl diisocyanate, 3,3'-dimethoxy-
4,4'-diphenylmethane diisocyanate,
3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,4-naphthalene diisocyanate, 1,5-naphthalene diisocyanate,
2,6-naphthalene diisocyanate, 2,7-
Naphthalene diisocyanate, p-xylylene diisocyanate, m-xylylene diisocyanate, 1,4-tetramethylene diisocyanate,
1,5-pentamethylene diisocyanate, 1,
6-hexamethylene diisocyanate, 1,7-
Heptamethylene diisocyanate, 1,8-octamethylene diisocyanate, 1,9-nonamethylene diisocyanate, 1,10-decamethylene diisocyanate, 2,2,4-trimethyl-1,
5-Pentamethylene diisocyanate, 2,2'-
Dimethyl-1,5-pentamethylene diisocyanate, 3-methoxy-1,6-hexamethylene diisocyanate, 3-ptoxy-1,6-hexamethylene diisocyanate, ω,ω'-dipropyl ether diisocyanate Examples of the diisocyanate include nitrate, 1,4-cyclohexyl diisocyanate, 1,3-cyclohexyl diisocyanate, and isophorone diisocyanate. The urethane-forming reaction between a polyol compound and a diisocyanate compound to obtain a polyurethane can be performed by a method known in the art. For example, if necessary, a urethanization catalyst such as a tertiary amine or a tin compound is used, and the reaction temperature is in the range of 40 to 100°C. Further, if [NCO]/[OH]>1, an isocyanate-terminated polyurethane can be obtained, and if [NCO]/[OH]<1, a hydroxyl-terminated polyurethane can be obtained. Introduction of unsaturated groups into polyurethane can be carried out by known methods. For example, isocyanate-terminated polyurethane may be reacted with acrylate or methacrylate containing at least one hydroxyl group according to a conventional method. This acrylate or methacrylate has the general formula (R ₄ in the formula is a hydrogen atom or a methyl group, R ₅ is -
CH ₂ −CH ₂ −,

【formula】

【formula】

[Formula] or

[Formula]) Compounds represented by the general formula (In the formula, R ₄ is the same as above, and R ₆ and R ₆ ' are linear or branched alkylene groups having 1 to 12 carbon atoms.) Compounds represented by the following, and the general formula (R ₄ in the formula has the same meaning as above, and R ₇ is -
CH ₂ −CH ₂ −O− or

Compounds represented by the following formula (n is an integer from 2 to 20) can be mentioned. Specific examples of the compound represented by the general formula () include N,N-dimethanol acrylamide, N,N-di(4-hydroxybutyl)acrylamide, and N-(2-hydroxyethyl)-N-
Examples include (2-hydroxypropyl)acrylamide and the corresponding methacrylamide. Among the compounds represented by the general formula (), when a compound containing two hydroxyl groups in one molecule is used, if necessary, after the reaction with isocyanate, the remaining hydroxyl groups and the dibasic acid Carboxyl groups may be introduced into the prepolymer by reacting with anhydride. Also, when introducing polyoxyethylene segments into unsaturated polyester prepolymers,
This can be carried out in accordance with known unsaturated polyester manufacturing techniques. The polyethylene glycol and ethylene oxide-propylene oxide copolymer used in this case are as described above, and the following compounds can be exemplified as other diols and dibasic acids that can be used in combination. That is, as glycols, for example, ethylene glycol, propylene glycol, 1,4-
Butanediol, 1,3-butanediol, 2,
3-butanediol, diethylene glycol, dibropylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, hydrogenated bisphenol A, trimethylene glycol, 2-
Ethyl-1,3-hexanediol, etc., and dibasic acids such as phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, hectic acid, tetrachlorophthalic anhydride, anthracene -Maleic anhydride adducts and the like can be mentioned. In addition, methods for introducing unsaturated groups include, for example, a method in which an unsaturated dibasic acid such as fumaric acid, maleic acid, or itaconic acid is used in combination with the above-mentioned dibasic acid, or a method in which glycidyl acrylate or glycidyl acrylate is used in polyester with a carboxyl group terminal. Examples include a method of adding methacrylate. The molecular weight of the prepolymer used in the composition of the present invention has a practically preferable range determined by the form of the intended photosensitive resin, and from the viewpoint of high sensitivity, which is the objective of the present invention, it is sufficient that it is at least 1000 or more, and the upper limit is is preferably about 80,000 in terms of photosensitive resin production. Examples of the ethylenically unsaturated monomer (B) used in the composition of the present invention, i.e., a crosslinking agent, include vinylpyridine, N-vinylcarbazole, acrylic acid, methacrylic acid, or an ester thereof, such as alkyl, cycloalkyl, tetrahydrocarbon Acrylates and methacrylates of furfuryl, allyl, glucidyl, hydroxyalkyl, mono- or di-acrylates and methacrylates of alkylene glycol, polyoxyalkylene glycol or mono-, di- or tri-acrylates and methacrylates of trimethylolpropane, mono-, di-, and di-acrylates of pentaerythritol, tri- or tetraacrylates and methacrylates, acrylamide, methacrylamide or derivatives thereof, such as N-methylolacrylamide and methacrylamide, N,
Styrene, vinyltoluene, N'-alkylene bisacrylamide and methacrylamide, diacetone acrylamide and methacrylamide, etc.
Divinylbenzene, diallyl phthalate, triacryl cyanurate, vinyl acetate, itaconic acid,
Addition-polymerizable unsaturated monomers such as fumaric acid, maleic anhydride, maleic acid and mono- and dialkyl esters of these acids, unsaturated polyester and alkyd resins, unsaturated polyurethane resins, active hydrogen such as hydroxyalkyl acrylates or methacrylates Examples include polyurethane resins modified with addition polymer monomers having the following. These crosslinking agents are used in an amount of 5 to 100 parts by weight per 100 parts by weight of the prepolymer, but the range of 30 to 70 parts by weight is easy to adjust from the viewpoint of plate properties. The photopolymerization initiator of component (C) used in the composition of the present invention has the general formula (R ₈ in the formula is a hydrogen atom or a linear or branched alkyl group having 1 to 8 carbon atoms, R ₉ is a hydrogen atom or -
OR ₈ group) benzoin, its derivatives,

[Formula] Examples include eosin, thionine, and diphenyl sulfide. Among these, the compounds represented by the general formula () and

[Formula] is effective when the resin layer to be cured is thick. These photopolymerization initiators may be used alone or in combination of two or more, and the amount of the photopolymerization initiator is 0.01 to 10% relative to the sum of the prepolymer and the ethylenically unsaturated monomer. A weight percent range is preferred. More preferably, amounts in the range 0.1 to 5% by weight are used to obtain suitable photospeeds. General formula of component (D) used in the composition of the present invention [In the formula, X ₁ is a hydrogen atom, a hydroxyl group, or -OR ₁ group (however, R ₁ is an alkyl group or an aralkyl group having 1 to 10 carbon atoms), X ₂ is a hydrogen atom,
5 alkyl group or -OR ₁ group (however, R ₁ has the same meaning as above), R ₂ and R ₃ have 1 to 5 carbon atoms
or one of which is a hydrogen atom and the other is an alkyl group having 1 to 5 carbon atoms], examples thereof include monomethylaminobenzaldehyde, dimethylaminobenzaldehyde, monoethylaminobenzaldehyde,
Diethylaminobenzaldehyde, mono- or di-n-propylaminobenzaldehyde, mono-
or mono- or dialkylaminobenzaldehydes such as diisopropylaminobenzaldehyde, mono- or dimethylaminobenzoic acid, mono-
or diethylaminobenzoic acid, mono- or di-n
-propylaminobenzoic acid, mono- or di-n-
Mono- or dialkylaminobenzoic acids such as pentylaminobenzoic acid, N-methyl-N-ethylaminobenzoic acid, N-methyl-N-n-butylaminobenzoic acid, and methyl, ethyl, n-propyl of the above benzoic acids. , isopropyl, n-butyl, sec-butyl, t-butyl, n-pentyl,
Examples include mono- or dialkylaminobenzoic acid alkyl esters such as isoamyl, n-octyl, and n-decyl esters. These compounds may be used alone or in a mixture of two or more. Among these compounds, mono- or dialkylaminobenzoic acid alkyl esters are preferred from the viewpoint of stability, and particularly A dialkylamino compound is preferred. In addition,

[Formula] Group

The relative positional relationship with the group [Formula] on the benzene ring may be ortho, meta, or para. In addition, the substituent other than the hydrogen atom introduced as the -X ₂ group is an alkyl group having 1 to 5 carbon atoms or -OR ₁
(However, R ₁ is an alkyl group or aralkyl group having 1 to 10 carbon atoms.) Among the -OR ₁ groups, the -OCH ₃ group has less steric hindrance and improves sensitivity. It is highly effective and preferable. The blending amount of this component (D) is 0.1 to 10% by weight based on the sum of the prepolymer and the ethylenically unsaturated monomer.
Preferably it is in the range of 0.5 to 5% by weight. If this amount is less than 0.1% by weight, there will be no sensitivity improvement effect, and
If it exceeds 10% by weight, the effect will not increase significantly considering the amount, and it is rather unfavorable in terms of cost. The thermal polymerization inhibitor (E) in the composition of the present invention is used for the purpose of stably storing the photosensitive resin composition. The thermal polymerization inhibitor can be added at the same time as mixing the components of the composition, or it can be added to each component in advance before mixing the components. Thermal polymerization inhibitors that can be used in the present invention include hydroquinone, mono-tert-butylhydroquinone, benzoquinone, 2,5-diphenyl-p-benzoquinone, picric acid, di-p-
-fluorophenylamine, p-methoxyphenol, 2,6-di-tert-butyl-p-cresol, and the like. It is desirable that these thermal polymerization inhibitors prevent the thermal polymerization reaction (dark reaction) without affecting the photocrosslinking reaction. Therefore, the blending amount of the thermal polymerization inhibitor is:
The amount is preferably in the range of 0.001 to 5.0% by weight based on the sum of the prepolymer and the ethylenically unsaturated monomer. For the purpose of appropriately adjusting the surface properties of the cured product, mechanical properties, water resistance, solvent resistance, etc. of the photosensitive resin composition of the present invention, various auxiliaries may be added to 100 parts by weight of the composition. Additives from 0.01 to 100 parts by weight can be used. The term "auxiliary additives" as used herein means anything other than the essential components (A) to (E) above. Typical examples include dioctyl phthalate, process oil, and silicone oil. The photosensitive resin composition of the present invention has a wavelength of 300 to 700n.
Advantageously, the curing is carried out by actinic radiation of m. Therefore, active light sources used for the photosensitive resin composition of the present invention include carbon arc lamps, ultra-high pressure mercury lamps, high-pressure mercury lamps, xenon lamps, ultraviolet fluorescent lamps, metal halide lamps,
Sunlight is preferable. Further, if necessary, an LED, a He-Ne laser, an Ar ion laser, or the like having an emission distribution in the above wavelength range may be used as a light source. When the photosensitive resin composition of the present invention is exposed through a negative (or positive) film having transparent image lines,
The exposed image area becomes an insoluble cured product in about 5 seconds to 5 minutes, although this varies depending on the light source used, the area of the image area, the thickness of the resin layer to be photocured, etc. Non-image areas that are not exposed to light can be sufficiently developed with an aqueous surfactant solution or an aqueous alkaline solution, but it goes without saying that the dissolution and removal phenomenon can also be achieved with organic solvents such as tricrene, perchlorene, chlorocene, acetone, methyl ethyl ketone, and ethyl acetate. After development, drying, and post-exposure, it is used as a printing plate. The characteristics of the present invention are that an ethylenic addition polymerizable prepolymer having a specific segment and a general formula (In the formula, X ₁ , X ₂ , R ₂ and R ₃ have the same meanings as above) By using a compound represented by The object of the present invention is that it is possible to provide a photosensitive resin composition that is stably highly sensitive and that cannot be obtained using conventional techniques. Conventionally, some of the ethylenic addition-polymerizable prepolymers having specific segments used in the present invention have been known as shown in the above-mentioned patent publications, but the effect of increasing sensitivity is not known, much less. General formula (), which is a feature of the present invention
Until now, it was unknown that the desired high sensitivity could be stably achieved only when used in combination with the compound represented by The present invention makes it possible to obtain a highly sensitive photosensitive resin composition that was previously unattainable even with various changes in the photopolymerization initiator, crosslinking agent, prepolymer, etc. In addition, if necessary, if the exposure time does not need to be changed, the light source intensity of the exposure equipment can be lowered, reducing equipment costs and utility costs such as electricity costs. can. Although the present invention is primarily intended for use in making relief plates, it can also be used for various plastics that are cured by actinic rays, such as paints, coating materials, adhesives, films, and molds. EXAMPLES Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples in any way. Example 1 Commercially available polypropylene adipate (acid value 2.0 mg
KOH/g, hydroxyl value 43.6mgKOH/g) 257.3g
(0.1 mol), commercially available polyethylene glycol (hydroxyl value 52.0 mgKOH/g) 215 g (0.1 mol), tolylene diisocyanate 52.3 g and a catalyst.
When 0.01% by weight of BTL (dibutyltin laurate) was added and the mixture was reacted for 2 hours at 80°C under a nitrogen atmosphere, a transparent sticky substance _A1 was obtained. The reaction rate of this OH was 99%. Next, this reaction product was mixed with 32 g of glycerin monomethacrylate under an air atmosphere.
(0.2 mol) and BHT (3,5-di-t-butyl-
When 0.1% by weight of 4-hydroxytoluene was added and the vinyl group introduction reaction was carried out for 2 hours, NCO
No absorption was observed on the IR chart. Furthermore, 20 g (0.2 mol) of succinic anhydride was added, and a half-esterification reaction was carried out until the acid value became 21 mg KOH/g, to obtain a terminally carboxylated polyurethane prepolymer. To 100 g of this prepolymer, 30 g of 2-hydroxypropyl methacrylate, 20 g of tetraethylene glycol methacrylate, 2 g of benzoin isobutyl ether, and 0.1 p-methoxyphenol were added.
2 g of p-(N,N-dimethylamino)benzoic acid ester were added to obtain a photosensitive resin composition. This material was exposed for 12 seconds using an ultra-high pressure mercury lamp,
Next, 1% sodium borate and 1% dispersant (manufactured by Lion Corporation, Liporan AO 15%, Liponox 15%)
(aqueous solution) was spray-developed at a pressure of 1 Kg/cm ² , washed with water and dried, and then the thickness of the photocured portion was measured at each step. The result is the first
Shown in the table. Example 2 Polycaprolactone (hydroxyl value 220mgKOH/
g, acid value 0.20mgKOH/g) 50.9g (0.1 mol) and ethylene oxide-propylene oxide copolymer (hydroxyl value 72mgKOH/g, number of moles of ethylene oxide 16) 155.6g (0.1 mol), 1,6-hexamethylene When 67.2 g (0.4 mol) of diisocyanate was added and reacted in an air atmosphere at 80° C. for 3 hours, the OH reaction rate was 100%. Next, 58.5 g (0.45 mol) of 2-hydroxyethyl methacrylate and 0.1% by weight of BHT were added to the reaction mixture, and the reaction was allowed to proceed until the absorption of NCO disappeared on the IR chart. To 100 g of the urethane prepolymer thus obtained, 40 g of 2-hydroxyethyl methacrylate, 20 g of polypropylene glycol dimethacrylate (average molecular weight of polypropylene glycol 600), 2,2-dimethoxy-
1.6 g of 2-phenylacetophenone,
A photosensitive resin composition was obtained by adding 0.16 g of BHT and 1 g of p-(N,N-dimethylamino)benzaldehyde. This material was exposed in the same manner as in Example 1. The results are shown in Table 1. Example 3 200 g (0.2 mol) of ethylene oxide-propylene oxide copolymer (hydroxyl value: 112 mg KOH/g, number of moles of ethylene oxide added: 8 mol), 41.8 g (0.24 mol) of tolylene diisocyanate, and
When 0.01% by weight of BTL was added and the mixture was reacted at 85°C for 4 hours in an air atmosphere, the OH reaction rate was 98%. Next, 50 g (0.05 mol) of polypropylene glycol monomethacrylate (molecular weight 1000) and 0.1 g of BHT were added, and the mixture was allowed to react until the absorption of NCO disappeared on the IR chart to obtain a urethane prepolymer. 100g of this, 30g of 2-hydroxyethyl methacrylate, 10g of trimethanolpropane trimethacrylate, 10g of diethylene glycol dimethacrylate, 1.5g of benzoin-n-propyl ether, 0.01g of BHT, p-(N-methyl-N-isoamylamino)benzoic acid Isoamyl ester 2
g was added to obtain a photosensitive resin composition. This composition was exposed in the same manner as in Example 1.
The results are shown in Table 1. Example 4 Fumaric acid/adipic acid/isophthalic acid at 0.2/
0.6/0.2 mole ratio, propylene glycol/polyethylene glycol (average molecular weight 400) 0.2/
0.8 mole ratio and dibasic acid/diol = 1/
The reaction was carried out at a molar ratio of 1.1, and the reaction was stopped when an acid value of 20 mgKOH/g was reached, yielding an unsaturated polyester prepolymer having a number average molecular weight of about 2,800. 100g of this, 25g of 2-hydroxyethyl methacrylate, 10g of tetraethylene glycol monomethacrylate, 15g of cyclohexyl methacrylate, 2.2g of benzoin-isobutyl ether,
A photosensitive resin composition was obtained by adding 0.1 g of BHT and 1.5 g of p-(N,N-diethylamino)benzoic acid ethyl ester. This composition was exposed in the same manner as in Example 1.
The results are shown in Table 1.

[Table] Examples 5 to 8 Using the prepolymers of Examples 1 to 4, respectively,
A photosensitive resin composition having the composition shown in Table 2 was prepared and exposed in the same manner as in Example 1. The results are shown in Table 2.

[Table] Comparative Example 1 Polypropylene glycol (hydroxyl value 53.0) was used instead of polyethylene glycol in Example 1.
mgKOH/g) 211 g (0.1 mol) was used.
A photosensitive resin composition was obtained in the same manner as in Example 1 and exposed. The results are shown in Table 3. Comparative Example 2 Ethylene oxide-propylene oxide copolymer in Example 2 (hydroxyl value 72 mgKOH/g,
A urethane prepolymer was prepared in the same manner as in Example 2, except that 220 g (0.1 mol) of the same copolymer (hydroxyl value 51 mgKOH/g, number of mols of ethylene oxide added 10 mol) was used instead of ethylene oxide (mol number 16). was prepared. Next, using this product, p-
A photosensitive resin composition was obtained and exposed in the same manner as in Example 2 except that (N,N-dimethylamino)-benzaldehyde was used. The results are shown in Table 3.

[Table] Example 9, Comparative Example 3 The photosensitive resin compositions obtained in Examples 1 and 2,
Using photosensitive resin compositions (referred to as compositions A and B, respectively) in which 0.2% by weight of triphenylphosphine was added to the photosensitive resin compositions used in Comparative Examples 1 and 2, Sensitivity and storage stability tests were conducted. The results are shown in Table 4.

[Table] As is clear from this table, the photosensitive resin composition of the present invention stably maintains a high sensitivity level even during storage. Application example Two coats of the photosensitive resin composition obtained in Example 1 were applied to the adhesive side of a 0.1 mm polyester sheet support coated with a polyurethane adhesive to a thickness of about 10 μm.
It was applied to a thickness of mm, then covered with a 12μ polypropylene film, a negative film was placed on top of it, and a glass plate was placed in close contact with the film. First, apply a chemical lamp (Toshiba FL-20BL) from the opposite side of the negative film.
After irradiating for 15 seconds from a distance of 10cm, a 2kW ultra-high pressure mercury lamp was used from a distance of 50cm from the negative film side.
When exposed for 30 seconds and developed as in Example 1, a relief plate with a total plate thickness of 2.1 mm and a relief height of 1.8 mm was obtained, and independent points with a diameter of 150 μm were formed on the negative film. On the other hand, the photosensitive resin composition obtained in Comparative Example 1 was used and exposed in the same manner as described above. Exposure to chemical lamp for 30 seconds and ultra-high pressure mercury lamp for 75 seconds, total plate thickness 2.1 mm, relief height 1.8
A relief plate of mm was obtained, but the diameter of the independent points formed on the plate was only 200μ on the negative film surface.

Claims (1)

[Claims] 1 (A) A polyoxyethylene segment is contained in the molecule, and the average molecular weight of the segment is 500 or more,
and at least one prepolymer selected from unsaturated polyurethanes and unsaturated polyesters having ethylenically addition polymerizable properties, which account for 5% or more of the total molecular weight; (B) an ethylenically unsaturated monomer; (C) Photoinitiator, (D) General formula [In the formula, X ₁ is a hydrogen atom, a hydroxyl group, or -OR ₁ group (however, R ₁ is an alkyl group or an aralkyl group having 1 to 10 carbon atoms), X ₂ is a hydrogen atom,
5 alkyl group or -OR ₁ group (however, R ₁ has the same meaning as above), at least one of R ₂ and R ₃ is an alkyl group having 1 to 5 carbon atoms, and the rest are hydrogen atoms] and (E) a thermal polymerization inhibitor.