JPS6021373B2 - Photosensitive resin composition with excellent storage stability - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photosensitive resin composition that has high storage stability and does not cause a decrease in sensitivity.

Traditionally, letterpress printing and metal-corrosion letterpress were the most commonly used printing plates, but these problems caused problems such as lead poisoning and lower back pain for workers due to transporting heavy objects, and water pollution caused by the etching solution used when working with metal-corrosion plates. As problems such as water pollution and poor workplace environments have become more apparent, printing using photosensitive resin as a plate material has become mainstream, as it has solved all of these problems.

It is predicted that this bidirectional printing will continue in the future, and that in the near future the majority of printing plates will be made up of photosensitive resin plates. - All of Taishi's photosensitive resin compositions contain a photosensitizer. This photosensitizer is present in the photosensitive resin, and when it is irradiated with actinic rays including ultraviolet rays, it is excited to a singlet state and changes into a triplet state, and then transfers energy to the photosensitive resin and emits light. Leads the photosensitive resin to become solvent-proof by either inducing a curing reaction or by decomposing itself with active light and activating the polymer or the photopolymerizable unsaturated monomer described below. It plays a pioneering role. Therefore, a fundamental question is raised here. That is, as mentioned above, since the photosensitive resin composition contains a photosensitizer, when exposed to actinic light that excites it, even if the illuminance of the actinic light is small, a photoresist reaction gradually occurs, resulting in liquid photosensitivity. With resin, the viscosity of the composition increases, leading to the disadvantage that defoaming is difficult and the thickness of the paper plate cannot be kept constant. Alternatively, gel components may be generated in some areas, resulting in not only poor developability but also a decrease in resolution. In addition, if the photopolymerizable unsaturated monomer contained in the photosensitive resin is heated or stored for a long period of time, the heat-linked polymerization inhibitor added will be decomposed and the photopolymerizable unsaturated monomer will react quickly. The polymerization progresses so quickly that the viscosity increases and finally solidifies.

Therefore, even if a photosensitive resin composition is stored in a place where it is not irradiated with actinic rays, the phenomenon of thickening or solidification is observed. In such a case, not only the quality deteriorates significantly but also the product loses its value as a product. A considerable amount of time passes from the time a manufacturer produces a photosensitive resin composition or a photosensitive resin master plate to the time it is delivered to each user, and the user also has to secure a certain amount to make printing plates. It may take a long time until it is used up, so there should be no change in quality during this time. Furthermore, while a cold light station environment is preferable for photosensitive resins during shipping and storage, it is desirable for photosensitive resins to maintain constant quality even under conditions of rising temperature and changing humidity. It is. Solid photosensitive resin master plates are supplied with a photosensitive resin layer of a certain thickness coated on aluminum, iron, or zinc plates, so they do not exhibit as noticeable changes in state as liquid photosensitive resins. However, if the storage stability is poor, there will be residual development on the shoulder area even if the development process is done quite vigorously, which may cause the characters to become thick when printed using this plate, or the prints may not be cut properly. I have no choice but to do so.

If the three-dimensional crosslinking reaction during storage progresses further, even if you try to develop it after applying a negative film and exposing it to light, it will not be able to be developed at all and will no longer be commercially viable. Usually, photosensitive resins include general radical inhibitors such as quinone compounds such as penzoquinone, p-toluquinone, and p-xyloquinone, hydroxyaromatic compounds such as hydroquinone, p-methoxyphenol, and p-te-butylcatechol, and phenyl -Q-naphthylamine, N. Amines such as N'-diphenyl-p-phenylenediamine are added.

However, it was confirmed that these compounds do not have sufficient storage stabilization ability for long-term storage of photosensitive resins. In addition, in any case, active intermediates are generated by the exposure to active light, which induces polymerization and crosslinking reactions, but the chemicals added as stabilizers harden the photosensitive resin due to light irradiation. Photosensitive resins that contain stabilizers that capture active intermediates during the process, hinder the photopolymerization reaction, or have staining properties may be severely colored, and the curing speed upon irradiation with light may be completely reduced. As a result of intensive research on these points, the present invention has been achieved.

That is, the present invention provides a photosensitive resin composition comprising a polymer A soluble in an aqueous solvent, a photopolymerizable unsaturated monomer B, a photosensitizer C, and a stabilizer ○, in which the stabilizer D has the general formula ( R,,R2
represents an alkyl group having 1 to 4 carbon atoms or a phenyl group.

) (R3 and R4 are alkyl groups or phenyl groups having 1 to 4 carbon atoms, M is a polyvalent metal of periods 1 and 0 of the periodic table, Machi and Wind groups, periods 4 and 5, lead, bismuth, 1 is 2 Represents an integer from ~4.

) (M2 is ammonium, periodic table 1~Hata group 3~6
Periodic metal, m represents an integer from 1 to 4.

) at least one compound selected from the group consisting of (1) thiurams, (0) dithiocarbamates, and (m) N-nitrosophenylhydroxylamine salts, wherein the stabilizer is added to polymer A. 0.0 against
It is a photosensitive resin composition characterized in that it is added in an amount of 0.01 to 5%.

The polymer A used in the present sardine may be any polymer that is soluble in water or a dilute alkali aqueous solution.
Maleic acid adducts of fin water of polyptadiene, polymers obtained by treating these adducts with sodium hydroxide, potassium hydroxide, lithium hydroxide, etc. (Tsubaki Sekisho 51-1 similar to 903), conjugated diolefin hydrocarbons E and Q,8 nitylenically unsaturated carboxylic acid F is essential, and a monoolefinically unsaturated compound G is added thereto in an amount of E: 10 to 90 mol%, F: 2 to 90 mol%, G: 0 to 85 mol%. A copolymer in which a portion of the Q, 3-ethylenically unsaturated carboxylic acid in the copolymer or nuclear polymer is an alkali Kanaya m salt, ammonium salt, or amine salt (Tsubaki Nuka Sho 51-50959, 51-8518
0 52-11241) is preferably used.

The above-mentioned conjugated diolefin hydrocarbon E is preferably 1,3-butadiene, isobrene, chloroprene, dimethylptadiene, etc., and the Q,8-ethylenically unsaturated carboxylic acid F is a monocarboxylic acid such as acrylic acid, methacrylic acid, etc. Acid, dicarboxylic acid such as maleic acid, fumaric acid, itaconic acid, acid anhydride such as maleic anhydride, itaconic anhydride, monoethyl maleate, monobutyl maleate, monoethyl fumarate, monobutyl fumarate, monoethyl itaconate, itaconic acid Monoesters of dicarboxylic acids such as monobutyl are suitable, and examples of monoolefin compounds include styrene, Q-methylstyrene, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, and the general formula (wherein R5 is hydrogen or a methyl group and & is (representing an alkyl group having 1 to 18 carbon atoms), benzyl acrylate, glycidyl acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate or their methacrylates, dimethyl maleate, dioctyl maleate, itaconic acid Dimethyl, dioctyl itaconate, etc., esters of 3-ethylenically unsaturated dicarboxylic acids, hydroxyalkyl alcohols such as 2-hydroxyethyl acrylate or methacrylate,
General formula (wherein R7 and R8 are hydrogen or a methyl group, R9 is an alkyl group having 1 to 12 carbon atoms, and n is an integer of 1 to 23.

), alkoxylalkyl acrylate or tacrylate, alkoxypolyalkylene glycol acrylate or methacrylate, etc. can be preferably mentioned. In addition to the monoolefinic unsaturated compounds mentioned above, photopolymerizable unsaturated monomers B include N,N'-methylenepisacrylamide or methacrylamide, ethylene glycol diacrylate or dimethacrylate, polyalkylene glycol (alkylene glycol), etc. Di-, tri-, and tetra-acrylates of polyhydric alcohols such as diacrylates or dimethacrylates of reel units 2 to 23), glycerin, bentaerythritol, trimethylolalkanes, and tetramethylolalkanes (alkanes include ethane, propane, etc.) or di-, tri-, tetramethacrylates, 2,2-bis(4-methacryloxydiethoxyphenyl)propane, 2,2-bis(4-acryloxydiethoxyphenyl)propane, 2,2-bis(
4-Acryloxypropyloxyphenyl)propane, diarylidenebentaerythritol, Aronics type monomer M-5500, M-570 manufactured by Toagosei Chemical Industry Co., Ltd.
0 M-6100. M-6300. M-8030, M-
8060 etc. can be exemplified.

These photopolymerizable unsaturated monomers contain 5 to 2
It is used in a range of 0% by weight, preferably in a range of 10 to 10% by weight.

Two or more types can be used in combination within this range. If it is less than 5% by weight, the curing speed when the photosensitive resin layer is exposed to light beams will be slow, and not only will the plate making time become longer, but a sufficient degree of curing cannot be expected, resulting in a decrease in the mechanical strength of the printing plate. .

If it exceeds 200% by weight, the photopolymerizable monomer in the photosensitive resin is too large, resulting in large volume shrinkage during photopolymerization and a momme point at which the printing plate does not faithfully reproduce a negative film.

Examples of the photosensitizer C used in the present invention include Q-diketones such as diacetyl and benzyl, which are commonly used as photoreaction initiators, acyloins such as benzoin and pivaloin, benzoin methyl ether, benzoin ethyl ether, and benzoin ethyl ether. Examples include acyloin ethers such as isopropyl ether, and polynuclear quinones such as anthraquinone and 1,4 naphthoquinone.

The amount of the photosensitizer added is 0.1 to 10% by weight, preferably 1 to 5% by weight, based on the weight of the polymer A.

If it is less than 0.1% by weight, the photocuring rate cannot be achieved to a sufficient value, and not only the exposure time must be increased, but also the crosslinking density becomes low, resulting in a decrease in the mechanical strength of the printing plate.

If the amount exceeds 1% by weight, not only is it uneconomical because all the added photosensitizer does not contribute to the photocuring reaction, but also the unreacted photosensitizer is extracted by the ink vehicle during printing, causing mechanical damage to the printing plate. This will have a negative effect on strength. The stabilizer D used in the present invention has the general formula (1) (R, , R2 is carbon number 1
~4 alkali group or phenyl group.

Examples of thiurams represented by ) include tetramethylthiuram monosulfide, tetraethylthiuram monosulfide, tetra-n-butylthiuram monosulfide, and N,N'-dimethyl-N,N'-diphenylthiuram monosulfide. Examples include sulfide, etc., and general formula (D) (R3, R
4 is an alkyl group having 1 to 4 carbon atoms or a phenyl group, M.
represents polyvalent metals of periods 1, 0 and W of the periodic table, periods 4 and 5 of the rainbow group, lead and bismuth, and 1 represents an integer from 2 to 4.

Examples of the dithiocarbamates represented by ) include zinc dimethyldithiocarbamate, zinc dietyldithiocarbamate, zinc sibutyldithiocarbamate, zinc ethyl phenyldithiocarbamate, copper dimethyldithiocarbamate, copper diethyldithiocarbamate, Cadmium dimethyldithiocarbamate, cadmium dimethyldithiocarbamate, lead dimethyldithiocarbamate, lead dimethyldithiocarbamate, bismuth dimethyldithiocarbamate, bismuth dimethyldithiocarbamate, selenium dimethyldithiocarbamate, selenium dimethyldithiocarbamate, tellurium dimethyldithiocarbamate, Tellurium tyldithiocarbamate, iron dimethyldithiocarbamate, iron dimethyldithiocarbamate,
Examples include nickel dimethyldithiocarbamate, nickel dimethyldithiocarbamate, nickel dibutyldithiocarbamate, and the general formula (m) (M2 is ammonium, a metal from period 1 to wind group 3 to 6 of the periodic table, m is 1 ~4
represents an integer.

) Examples of the N-nitrosophenylhydroxylamine salts represented by are ammonium-N-nitrosophenylhydroxylamine, sodium-N-nitrosophenylhydroxylamine, magnesium-N-nitrosophenylhydroxylamine, and aluminum-N-nitrosophenylhydroxylamine. Nitrosophenylhydroxylamine, tin-N-nitrosophenylhydroxylamine, vanadium-N-nitrosophenylhydroxylamine, chromium-N-nitrosophenylhydroxylamine, manganese-N-nitrosophenylhydroxylamine, iron-N-nitro Examples include sophenylhydroxylamine, nickel-N nitrosophenylhydroxylamine, and the like.

The amount of these stabilizers added is 0.001 to Polymer A.
-5% by weight, preferably 0.01-2% by weight, and within this range, several types of homologous compounds may be mixed, or several types of stabilizers (1) to (m) may be mixed. It is okay to mix them.

The amount of stabilizer added is 0. If the amount is less than 1% by weight, it will not be possible to provide a sufficient storage stabilizing effect to the photosensitive resin;
If the amount exceeds % by weight, the stabilizer will not be sufficiently dissolved in the photosensitive resin layer, resulting in significant negative effects such as a decrease in sensitivity as well as a decrease in the mechanical strength of the printing plate.

Among the commercially available photopolymerizable unsaturated monomers mentioned above, p
- Although a small amount of thermal polymerization inhibitor such as methoxyphenol is added, in order to use it in the present invention, this small amount of thermal polymerization inhibitor does not affect storage stability, sensitivity, etc. at all, so it is necessary to , the thermal polymerization inhibitor can be used as it is without being removed from the photopolymerizable unsaturated monomer. The liquid photosensitive resin according to the present invention is prepared by adding a photopolymerizable unsaturated monomer, a photosensitizer, and a stabilizer to a solution in which Polymer A has been synthesized, and mixing thoroughly before using it during polymerization. It is produced by removing the solvent or uniformly mixing a photopolymerizable unsaturated monomer, a photosensitizer, and a stabilizer with a polymer from which the polymerization solvent has been removed in advance. The photosensitive resin is produced by adding each drug to a polymer solution to make a homogeneous solution, and then casting it on a support, or by heating and depressurizing the homogeneous solution to remove the solvent. It is usually manufactured by hot press molding a resin composition onto a support through a spacer of a constant thickness.

As mentioned above, when storing a liquid photosensitive resin, if the storage stability is good, the viscosity of the composition will not change and no gel will occur, but if the storage stability is poor, the viscosity will change significantly. A gel is generated partially, and when stored further, the entire product finally solidifies.

Therefore, in order to investigate the storage stability, the viscosity of the Y liquid photosensitive resin immediately after production and after storage for a certain period of time was measured using a B-type rotational viscometer at 30'0, and the degree of viscosity increase was determined according to the formula below. This was used as a guideline for storage stability. Half-occupancy jacket=V,=Viscosity of liquid photosensitive resin immediately after production V2=
It represents the viscosity of liquid photosensitive resin after storage for a certain period of time.

In addition, in the case of solid photosensitive resin, the photosensitive resin original plate is dissolved in a solvent immediately after production and after being stored for a certain period of time, and the weight percent of the gel (gel percentage) with no insoluble area is calculated using the following formula, which is a guideline for storage stability. And so.

Autumn rate = death and X・oo However, Wo=sample weight (of W represents the weight (g) of the dissolved sample vinegar.

The photosensitive resin composition of the present invention not only has excellent storage stability, but also has no decrease in sensitivity, making it possible to provide an excellent photosensitive material for printing whose quality remains constant over a long period of time.

Furthermore, the photosensitive resin composition of the present invention can not only provide a photosensitive material for printing, but also be widely used as a photosensitive material for name plates, printed wiring, displays, and photoadhesives. EXAMPLES Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples as long as the gist thereof is not exceeded.

Example 1 Butadiene/methyl noacrylic acid methacrylate synthesized by radical polymerization using methanol as a solvent and 2,2'-azobisisobutyronitrile as a catalyst = 54/28
/18 (molar ratio) 114.8 methanol solution of 61% by weight copolymer was placed in a 300 [separable flask], and 49 molar of tetradecaethylene glycol dimethacrylate, 1.4 molar of benzoin isopropyl ether, 0.35 ml of tetramethylthiuram monosulfide was added and stirred until a homogeneous solution was obtained.

A liquid photosensitive resin composition was prepared by immersing a separate flask in a water bath controlled at about 40° C. and completely distilling off the solvent methanol while shaking the flask. The composition was placed on a polyester film (8 x 8 skin thickness 100 mm) for about 9 days, and passed through a 1.5 rib thick substrate.
A polyester film with a thickness of 100 µm was placed on the composition, and a glass plate with a thickness of 5 ribs was further placed on top of the polyester film and pressed to form a layer of the composition with a thickness of 1.5 ribs.

After irradiating the glass plate with ultraviolet rays from a 250W ultra-high pressure mercury lamp for 5 seconds from the top surface of the glass plate, the glass plate and the upper polyester film are removed.The upper polyester is covered with a photocured photosensitive resin layer, while the lower polyester is uncured. A viscous steel body remained. The upper polyester film with the cured layer was sprayed with a 0.5% aqueous sodium hydroxide solution for 1 minute to completely remove uncured areas, washed with water, and then dried for IQ minutes at 80 qo. When the thickness of the hardened layer was measured, it was found to be 310 peaks. Therefore, the degree of phosphorescence of the composition is 62 f/s
It is c. The composition was placed in a clear glass sample bottle above the capacity loo, and the viscosity was measured at 3000 ps and found to be 2500 ps. The sample pin containing the photosensitive resin composition was placed in a constant temperature bath controlled at 30 qo under a fluorescent lamp that cut off active rays of 50 m or less to examine storage stability. After storage for 6 months, the viscosity was measured and found to be 2500 ps, with no change at all, indicating extremely high storage stability.

Further, the above-mentioned photocuring speed value was 62 r/sec, with no change at all, and no decrease in sensitivity was observed. Approximately 5 days of the photosensitive resin composition, which had been stored for 6 months, was placed on a sand-supported aluminum plate (8 x 8 squares, 300 mm thick), and the composition was surrounded by a base plate with a thickness of 0.8 mm.

On the other hand, a negative film was placed on a glass plate designed to be able to be subjected to reduced pressure, and covered with a durable 1,2-polybutadiene film having a thickness of 20 peaks, the negative film was brought into close contact with the glass surface under reduced pressure. The negative film side of this glass plate was pressure-bonded to the composition on the aluminum support mentioned above to form a photosensitive layer having a thickness of 0.8. was irradiated for 1 minute. When the unirradiated areas were removed by spraying with a 0.5% aqueous sodium hydroxide solution for 1 minute, a leaf that was truly faithful to the original drawing could be produced. When printing with letterpress ink and ink using this printing plate, printed matter with excellent ink transfer properties was obtained. therefore,
It was found that this photosensitive resin composition has extremely high stability even when stored at 300° C. for 6 months, with no change in quality at all. Comparative Example 1 A liquid photosensitive resin composition was prepared in the same manner as in Example 1 except that the stabilizer tetramethylthiuram monosulfide was replaced with hydroquinone.

The viscosity of this composition was 2,700 specific ps, the optical rate was 59/sec, and the performance immediately after production was almost the same as that of the composition of Example 1. When the storage stability was investigated in the same manner as in Example 1, gel was deposited at the bottom of the sample bottle, indicating that the three-dimensional crosslinking reaction had proceeded, and at the same time the viscosity increased to 64,800 specific ps, indicating the degree of viscosity increase. is 2
It became 3. An attempt was made to make a plate using this material, but the viscosity was too high, making it impossible to maintain a constant plate thickness, and the developability deteriorated, making it difficult to produce a satisfactory printing plate. Therefore, the storage stabilizing effect of hydroquinone is much weaker than that of tetramethylthiuram monosulfide, and in order to stably store a composition containing hydroquinone, it has been necessary to store it at a very low temperature. Examples 2 to 11 Liquid photosensitive resin compositions were prepared in the same manner as in Example 1 except that tetramethylthiuram monosulfide was replaced with the stabilizer shown in Table 1, and the viscosity increase rate and photocuring before and after storage were determined. The speed was measured and the results shown in Table 1 were obtained.

Table 1 Although the storage stabilizing effect is slightly lower than that of the tetramethylthiuram used in Example 1, there is no problem in using it as a liquid photosensitive resin at this level of viscosity increase. When a plate was made from the photosensitive resin composition, a printing plate with good sensitivity and developability was produced, and very good printed matter was obtained from this printing plate.

Examples 12 to 10 Comparative Examples 2, 3 A liquid photosensitive resin composition was prepared in exactly the same manner as in Example 1 except that the amount of tetramethylthiuram monosulfide added was changed as shown in Table 2, and the viscosity increased, before and after storage. The photocuring speed was measured and the results shown in Table 2 were obtained.

All of the photosensitive resin compositions shown in Table 2 Examples had good storage stability, and it was possible to produce sufficiently satisfactory plates and printed matter from the photosensitive resin compositions after storage for 6 months.

The storage stability of the composition shown in Comparative Example 2, in which the amount of tetramethylthiuram monosulfide added was small, was poor, and the degree of increase in viscosity increased after storage for 6 months, making it difficult to prepare a sufficient printing plate from this composition. was difficult. The composition of Comparative Example 3 in which the added amount of tetramethylthiuram monosulfide was increased had a high storage stabilizing effect, but the photocuring speed was slow, making it difficult to produce a printing plate that could be put to practical use in the future.

Examples 17-19 Tetramethylthiuram monosulfide was used as the stabilizer in Table 3, and tetradecaethylene glycol dimethacrylate was used as the stabilizer in Table 3.
, 2-bis(4-acryloxydiethoxyphenyl)propane/ethoxyethyl methacrylate = 4/1 (weight) except that a liquid photosensitive resin composition was prepared in the same manner as in Example 1, The degree of viscosity increase and the photocuring speed before and after storage were measured, and the results shown in Table 3 were obtained.

Table 3 There was no problem with storage stability in any case, and the photocuring rate hardly changed before and after storage, indicating that these stabilizers are effective.

Furthermore, a solid plate having a thickness of 3 was prepared from the photosensitive resin composition of the example shown in Table 3 by exposing the entire surface to light without using a negative film. The tensile strength of this solid plate was measured according to JIS K6301, and the results are shown in Table 4. Table 4 Tensile strength (&I) Example 17 90 18 87 19 140 The tensile strength of the plate can be increased by adding a stabilizer such as tetramethylthiuram monosulfide to N-nitrosophenylhydroxylamine salts. Understood.

Good printing plates and printed matter with excellent ink transfer properties were produced from the photosensitive resin compositions of Examples 17 to 19 after storage. Example 20 5% by weight methanol solution of butadiene/acrylonitrile/methacrylic acid = 45/33/22 (mole ratio) copolymer synthesized using methanol as a solvent and 2,2'-azobisisobutyronitrile as a catalyst. 100% of the copolymer was put into a 300ml upper separable flask, and 50ml of water containing 50% of IJ hydroxide was added thereto while stirring to neutralize 70% of the carboxyl groups contained in the copolymer.

Next, nonaethylene glycol dimethacrylate 17
．． After 5 minutes, 7.5 minutes of 2-hydroxyethyl methacrylate, 1 night of benzoin isopropyl ether, and 0.25 minutes of zinc diethylcarbamate were added and thoroughly mixed until completely mixed. The separable flask was immersed in a water bath at 40:00, and methanol and water were removed under reduced pressure to obtain a solid photosensitive resin composition.

The composition was placed on a grained aluminum plate (8 x 8, 300 mm thick) for about 3 days and pressed through a 0.5 mm thick surfacer at 100°C and 100 k9/sha for 3 days. A solid photosensitive resin original plate was produced by molding. Peel off the resin layer of the original plate, put 2.0 liters of it into a 25-inch square flask, add 18 liters of a mixed solvent of 50/50 (weight ratio) of ethanol/water, mix well, and let it stand at room temperature. After leaving it for 2 minutes, it was further filtered and filtered through a Millipore filter with a pore diameter of 1 mm.The amount of solids in the furnace liquid was measured, and a value of 1% by weight was obtained, indicating the composition of the photosensitive resin of the original plate. The material showed no gel content.

This original plate was placed in a glass container, placed in a room where the atmosphere was controlled to 30 qo and light of 50 m or less was cut off, and stored for 6 months. After storage, the dissolution test of the resin layer was performed as described above, and the result was 1% by weight, indicating that it was completely dissolved in the methanol/water mixed solvent and had excellent storage stability without gel formation. I understand.
By attaching a negative film to the original plate under reduced pressure before and after storage, irradiating it with ultraviolet rays from a 250W ultra-high pressure mercury lamp for 1 minute from a distance of 60 skins above the original plate, and spray developing it with 40qo warm water, a printing plate that is completely faithful to the original image can be obtained. It was found that there was no difference between the plates before and after storage, and there was no decrease in sensitivity. Comparative Example 4 A solid photosensitive resin original plate was prepared in the same manner as in Example 20, except that p-methoxyphenol, which is commonly used as a thermal polymerization inhibitor, was used instead of zinc diethylcarbamate.

The resin layer of the original plate before storage was completely dissolved in the methanol/water mixed solvent, but in the dissolution test of the resin layer after 6 months of storage, it was already dissolved in methanol/water before being filtered through the Millipore filter.
An insoluble area in the mixed solvent at water temperature was observed, and when the gel rate was measured, it was found that 65% by weight of the original plate had been gelled.
Although attempts were made to use this original plate, it was difficult to produce a satisfactory printing plate due to its poor developability. Comparative Examples 5 to 7 A liquid photosensitive resin composition was prepared in the same manner as in Example 1 except that tetramethylthiuram monosulfide was replaced with the stabilizer shown in Table 5. The curing speed was measured and the results shown in Table 5 were obtained.

．． Table 5 Photo-curing rate viscosity 〃/sec Comparative example Stabilizer Rise rate Before storage After storage 5
2 We apologize for the inconvenience. 48 51 Trimethylben 6 Dilammonium 36 57 Muchloride 7 Dimethylnitro 45 65 Soamine All compositions have a high viscosity increase and cannot be used for plate making.
It was found that each of the stabilizers shown in Table 5 had no stabilizing effect.

Claims (1)

[Claims] 1. In a photosensitive resin composition comprising a polymer A soluble in an aqueous solvent, a photopolymerizable unsaturated monomer B, a photosensitizer C and a stabilizer D, the stabilizer D is generally Formulas ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (R_1 and R_2 represent an alkyl group or phenyl group with 1 to 4 carbon atoms.) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (R_3 and R_4 are 4 alkyl group or phenyl group, M_1 is group I, II, VI, VIII group 4 of the periodic table
, 5 periods of polyvalent metals and lead, bismuth, 1 represents an integer from 2 to 4. ) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (M_2 is ammonium, periodic table 1 ~ VIII group 3 ~
6 periods of metal, m represents an integer from 1 to 4. ) at least one selected from the group consisting of (I) thiurams, (II) dithiocarbamates, and (III) N-nitrosophenylhydroxylamine salts.
a compound in which the stabilizer is 0.0% relative to Polymer A;
A photosensitive resin composition characterized in that the content of the photosensitive resin composition is 0.001 to 5% by weight.