JPH0448211B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a photosensitive image forming material, and more specifically, it is developable with an aqueous alkaline developer, has sufficient photosensitivity, and has excellent printing durability and oil sensitivity when used as a printing plate. The present invention relates to a photosensitive image forming material having the following properties.

[Formula] Skeleton (hereinafter referred to as cinnamic acid skeleton) performs a unique photoduplexing reaction, so various photosensitive resins with a cinnamic acid skeleton introduced into the side chain or main chain of the molecule have been studied. It is. Examples include polyvinyl alcohol, polyepichlorohydrin, polystyrene, acrylic resins, epoxy resins, and polyesters and polyamides having a cinnamic acid skeleton in the main chain, some of which have been put into practical use. For example, there are polyvinyl cinnamic esters produced by the reaction of polyvinyl alcohol and cinnamic acid chloride, and polyesters produced by the condensation of diethyl phenylene diacrylate and 1,4-di-β-hydroxyethoxycyclohexane. , these are used as image forming materials for printing plates, LSI devices, etc. Among the photoduplexing type photosensitive resins mentioned above, photosensitive polyester resins having a cinnamic acid skeleton in the molecular main chain produced by the condensation of phenylene diacrylic acid or its alkyl ester with glycol are relatively expensive. It is said to have photosensitivity. However, since these photosensitive resins exhibit solubility only in organic solvents, organic solvents are used as developing solutions when developing photosensitive layers made from these resins. When using an organic solvent as a developer, there are many problems in terms of development workability, safety and health of the working environment, economic efficiency, and prevention of air pollution and other pollution, and it is also more expensive than an aqueous developer. It is desired to develop a photosensitive resin that can be developed with an aqueous developer. In recent years, as such resins, photosensitive resins having a phenylene diacrylate group or a cinnamoyloxy group in the main chain and a sulfonate salt group adjacent to an aromatic nucleus (JP-A-18625-1862, JP-A-52-1999) have been developed.
130897, etc.), but when used as a photosensitive material for printed matter, such conventional resins can be developed with an aqueous developer, but moisture in the air causes the plate to become sticky. In some cases, these are still unsatisfactory in terms of poor oil sensitivity and printing durability, and improvements are desired. It is therefore an object of the present invention to provide an imaging material that is developable with an aqueous alkaline developer. Another object of the present invention is to provide a photosensitive image forming material that has sufficient photosensitivity, printing durability, and oil sensitivity when used as a photosensitive material for printing plates. The present inventors have developed a general formula as a method to achieve such an objective. (In the formula, A represents a linear polyester structural unit containing a photosensitive unsaturated double bond adjacent to an aromatic nucleus in the main chain, and R ₁ represents a tetravalent organic group.) Provided is a photosensitive image forming material that can be developed with an aqueous alkaline developer and is characterized in that the photosensitive layer contains a photosensitive polyester resin having the following properties. The photosensitive polyester resin used in the present invention has a dicarboxylic acid (hereinafter referred to as photosensitive unsaturated dicarboxylic acid) unit having a photosensitive unsaturated double bond adjacent to an aromatic nucleus, a glycol unit, and a line having a hydroxyl group at the terminal. It can be produced by a method of producing a linear polyester (hereinafter referred to as linear polyester) and then reacting the resin with an acid anhydride (hereinafter this method is referred to as the acid anhydride method). Examples of the photosensitive unsaturated dicarboxylic acid unit used in the acid anhydride method described above include the following general formulas (1) to
The derivatives of these dicarboxylic acids include dialkyl esters such as dimethyl ester and diethyl ester, di(ethylene glycol) ester, and di(propylene glycol) ester of these dicarboxylic acids. Examples include di(alkylene glycol) esters such as glycol esters, dicarboxylic acid halides such as dicarboxylic acid chlorides, and the like. (In the above general formulas (1) to (7), R ₂ and R ₂ ' are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, and 1 to 4 carbon atoms.
4 represents an alkoxyl group, a halogen atom or a nitro group, R ₃ represents an alkylene group having 2 to 4 carbon atoms, l represents an integer of 1 to 5, and n represents an integer of 1 to 4.
m represents an integer of 1 to 5. ) Preferred examples of the dicarboxylic acids or derivatives thereof include p-phenylene diacrylic acid, m-phenylene diacrylic acid, 2,5-dimethoxy-p-phenylene diacrylic acid, and 2-nitro-p-phenylene diacrylic acid. Diacrylic acid, p-carboxycinnamic acid, cinnamylidenemalonic acid, bis(p-cinnamic acid) diethylene glycol ether, bis(p-carboxybenzal)cyclohexanone, bis(p-carboxybenzal)cyclopentanone, P, Dicarboxylic acids such as P'-chalcone dicarboxylic acid or derivatives thereof can be mentioned. In producing the linear polyester resin, other polyhydric carboxylic acids or derivatives thereof can be used in combination with the above-mentioned photosensitive unsaturated dicarboxylic acids or derivatives thereof, and examples of such compounds include succinic acid, adipic acid, azelaic acid, Sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, tetrabromophthalic acid, tetrachlorophthalic acid, 1,4-cyclohexanedicarboxylic acid, maleic acid, fumaric acid, itaconic acid, 5- Dicarboxylic acids such as sodium sulfoisophthalic acid, anhydrides thereof, ester derivatives thereof, etc. can be used. However, the use of large amounts of these other dicarboxylic acids or their derivatives should be avoided since it will cause a decrease in the photosensitivity of the resin, and in order to obtain sufficiently high photosensitivity, the content of photosensitive unsaturated dicarboxylic acid units It is desirable that the amount is 30 to 100 mol% of the total dicarboxylic acid units in the linear polyester resin. On the other hand, the glycol unit can be derived from various types without particular limitations, such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, neopentyl glycol,
3-butylene glycol, 1,6-hexanediol, 2-butene-1,4-diol, 2,2,
4-trimethyl-1,3-pentanediol,
1,4-bis-β-hydroxyethoxycyclohexane, cyclohexanedimethanol, tricyclodecane dimethanol, hydrogenated bisphenol A,
Hydrogenated bisphenol F, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, ethylene oxide adduct of bisphenol F, propylene oxide adduct of bisphenol F, ethylene oxide of hydrogenated bisphenol A Adducts, propylene oxide adducts of hydrogenated bisphenol A, etc. can be used. When synthesizing a linear polyester resin having a hydroxyl group consisting of a dicarboxylic acid unit containing a unit derived from a photosensitive unsaturated dicarboxylic acid and a glycol unit, it is necessary to obtain a linear polyester resin having a hydroxyl group at both ends of the molecule. It is desirable to select a blending ratio such that the hydroxyl group of the glycol is 1 equivalent or more, preferably 1.1 to 2.0 equivalents, per 1 equivalent of a group derived from a carboxylic acid such as a carboxyl group or an ester group of the acid used in the reaction. . Linear polyester resins can be easily produced by means known in the field of conventional polyester resin synthesis. That is, it can be produced by preparing the above dicarboxylic acid component and glycol component in a predetermined blending ratio and reacting (esterification reaction or transesterification) in the presence of a catalyst and inhibitor added as necessary, and the reaction temperature is , 150～
250°C is preferred. In addition, when a relatively low molecular weight glycol is used during synthesis, the reaction may be carried out by adding an excess amount of the glycol component to the predetermined amount, and after the reaction is completed, the pressure in the reactor is gradually reduced to remove the excess amount. It can be produced by distilling glycol. The reaction temperature is preferably 150 to 250°C, and the reduced pressure is preferably 3 mmHg or less. Examples of catalysts used in producing linear polyester resins include tetraisopropyl titanate, tetraisopropyl titanate, tetrabutoxytitanate, dibutyltin oxide,
Organic metal compounds such as dibutyltin laurate, lithium ethoxide, zinc acetate, manganese acetate, and calcium acetate; inorganic metal compounds such as titanium dioxide, antimony trioxide, calcium oxide, and zinc chloride can be used. The amount used is preferably 50 to 10,000 ppm as a metal component. Inhibitors are used to minimize crosslinking and branching of ethylenically unsaturated groups that tend to occur during polycondensation reactions, and include, for example, phenothiazine, hydroquinone, hydroquinone monomethyl ether, 2,6-ditert -Butyl-p-cresol, p-benzoquinone, etc. can be used. The amount used is preferably 50 to 2000 ppm. The linear polyester resin produced as described above preferably has a hydroxyl value of 15 to 360. If the hydroxyl value is less than 15, it becomes difficult to develop with an aqueous solution of the image forming material of the present invention, and the hydroxyl value When is 360 or more, it becomes difficult to obtain sufficient sensitivity. Examples of acid anhydrides that can be used in the acid anhydride method described above include pyromellitic dianhydride, 3,
3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-diphenyltetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride anhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 4,4'-sulfonyldiphthalic dianhydride, 2,2-bis(3,
4-dicarboxyphenyl)propane dianhydride,
Bis(3,4-dicarboxyphenyl)ether dianhydride, 4,4'-[3,3'-(alkylphosphoryldiphenylene)-bis(iminocarbonyl)]diphthalic dianhydride, hydroquinone diacetate Aromatic tetracarboxylic dianhydrides such as adducts of diacetyldiamine and trimellitic anhydride, and adducts of diacetyldiamine and trimellitic anhydride; 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-
Cyclohexene-1,2-dicarboxylic anhydride (manufactured by Dainippon Ink & Chemicals KK, Epiclon B-
4400), 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, tetrahydrofuran tetracarboxylic dianhydride, and other alicyclic tetracarboxylic dianhydrides. Acid dianhydride; 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,4,5-
Aliphatic tetracarboxylic dianhydrides such as pentane tetracarboxylic dianhydride can be used. In the production of photosensitive polyester resin, the amount of acid anhydride used is 0.5 to 1 equivalent of hydroxyl group in linear polyester resin.
It is preferable to choose a range of 1.5 equivalents, preferably 0.7 to 1.2 equivalents. Hydroxyl group of linear polyester resin 1
When the number of equivalents of acid anhydride groups is less than 0.5 or more than 1.5 equivalents, the resulting photosensitive resin tends to have difficulty in obtaining sufficient photosensitivity. The reaction between linear polyester resin and acid anhydride is
○B A reaction system in which a predetermined amount of acid anhydride is added to a molten linear polyester resin, or ○B A reaction system in which a linear polyester resin is dissolved in an organic solvent and a predetermined amount of acid anhydride is added. It can be carried out. Preferred reaction conditions naturally vary depending on the reactivity of the acid anhydride used, the presence or absence of a catalyst, etc., but generally speaking, the reaction temperature is preferably from room temperature to 250°C. This reaction can be carried out by mixing and stirring the two in a melt or solution in a normal reactor, as well as
In the case of ○a, for example, the reaction can be caused by mixing both in an extruder. The organic solvents used in the above reaction include chlorinated solvents such as methylene chloride, chloroform, trichloroethane, trichloroethylene, chlorobenzene, dichlorobenzene, and carbon tetrachloride; ether solvents such as tetrahydrofuran and dioxane; glycol methyl ether acetate, Ester solvents such as glycol ethyl ether acetate and ethyl acetate; methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 4-methyl-4-
Ketone solvents such as methoxy-2-pentanone; dimethylformamide, dimethylacetamide, N
- Nitrogen-containing solvents such as methylpyrrolidone and nitrobenzene; dimethyl sulfoxide and the like; the above solvents can be used alone or in a mixture of two or more. For example, by the method described above It has a repeating unit represented by , and has an acid value of 15
A photosensitive polyester resin having an acid value of ~215 can be obtained, and a photosensitive polyester resin having an acid value in this range can be developed with an aqueous alkaline developer. It is desirable to use a photosensitive polyester resin having an acid value within this range for producing the photosensitive image forming material of the present invention. The image forming material according to the present invention is produced by preparing a composition in which the photosensitive polyester resin described above is dissolved in a suitable solvent, or if necessary, a sensitizer, a pigment, a dye, a filler, a stabilizer, and a crosslinking agent. This can be carried out by coating a composition containing additives such as a plasticizer and a plasticizer on a support. Suitable solvents vary depending on the composition and molecular weight of the resin, but are usually organic solvents used in the reaction of the linear polyester resin and acid anhydride; alcoholic solvents such as tetrahydrofurfuryl alcohol and benzyl alcohol; glycol monomethyl ether and glycols. Glycol monoalkyl ether solvents such as monoethyl ether; etc., and the above solvents can be used alone or in combination of two or more. Any sensitizer that can be used in this field can be used, including benzophenone derivatives,
benzanthrone derivatives, quinones, aromatic nitro compounds, naphthothiazoline derivatives, benzothiazoline derivatives, ketocoumarin compounds, or
Pyrylium salts, thiapyrylium salts, etc. can be used. Examples of such sensitizers include Michler's ketone, diethylaminoethylbenzophenone, benzanthrone, (3-methyl-1,3-diaza-1,9-benz)anthrone picramide, 6,
11-dichlorobenzanthrone, 6-phenyl-
Benzanthrone, 1,8-dimethoxyanthraquinone, 1,2-benzanthraquinone, 5-nitroacenaphthene, 2-nitrofluorene, 2,
7-dinitrofluorene, 1-nitronaphthalene, 1,5-dinitronaphthalene, P-nitrodiphenyl, 2-dibenzoylmethylene-3-methylnaphthothiazoline, 2-benzoylmethylene-
1-Methylnaphthothiazoline, 2-bis(furoyl)methylene-3-methylbenzothiazoline, 2
-benzoylmethylene-3-methylbenzothiazoline, 3,3-carbonyl-bis(7-diethylaminocoumarin), 2,4,6-triphenylthiapyrylium perchlorate, 2,6-bis(p
-ethoxyphenyl)-4-(p-n-amyloxyphenyl)-thiapyrylium perchlorate and the like. The above photosensitive resin composition is formulated to have an appropriate viscosity so that it can be applied to commonly used coating techniques such as dip coating, curtain coating, roll coating, spray coating, air knife coating, doctor knife coating, and spinner coating. It is applied to the support by a well-known coating method such as. Specific examples of the support include aluminum plates, zinc plates, copper plates, stainless steel plates, and other metal plates;
Sheets and plates made of synthetic resins such as polyethylene terephthalate, polycarbonate, and cellulose derivatives; paper coated with synthetic resin by melt coating or synthetic resin solution, and metal layers applied to synthetic resin using techniques such as vacuum deposition and lamination. Composite materials; examples include silicon wafers. The image-forming material of the present invention is particularly suitable for use as a printing plate, and when used as a printing plate, the support may be made of mechanically, chemically or electrochemically roughened aluminum, copper, zinc or the like. A metal plate or the like is used, on which a photosensitive layer usually having a thickness of 0.1 to 2.5 microns is formed. The photosensitive layer of the image forming material of the present invention is subjected to imagewise exposure using a negative image to harden and insolubilize the exposed areas of the photosensitive layer, and then developed to dissolve and remove the unexposed areas, thereby forming a corresponding image on the support. An image can be formed. Suitable light sources used for exposure include carbon arc lamps, mercury lamps, xenon lamps, metal halide lamps, lasers, and the like. As described above, the photosensitive image forming material of the present invention is extremely effective for forming a photosensitive layer of a printing plate, but the use of the image forming material of the present invention is not necessarily limited to the photosensitive layer of a printing plate. For example, it can also be used as a photoresist for various types of microfabrication. EXAMPLES Hereinafter, the present invention will be specifically explained with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof. Examples 1 to 10 (1) Manufacturing method A of linear polyester units Each mixture having the composition listed in Table 1 was mixed with a catalyst (600 mg of dibutyltin oxide) and an inhibitor (60 mg of phenothiazine) in a stirring device and nitrogen gas. Pour into a reactor equipped with an inlet tube, a thermometer, and a distillation tube, and while stirring under a nitrogen gas atmosphere.
The reaction was started by heating to 190°C. Heating and stirring were then continued for 3 and a half hours to completely distill off the ethanol produced by the reaction, yielding a linear polyester resin having the hydroxyl value shown in Table 1. Method B A mixture having the formulation shown in Table 1 and an inhibitor (60 mg of phenothiazine) were placed in the same reactor as in Method A, heated to 150°C with stirring under a nitrogen gas atmosphere, and the catalyst (tetraisopropyl The reaction was started by adding 200 mg of titanate.
Thereafter, the temperature was raised to 220°C over 1 hour, and heating and stirring were continued at the same temperature for 1 hour to completely distill off the ethanol produced by the reaction.
A linear polyester resin having the acid production group values listed in Table 1 was obtained. (2) Production of photosensitive polyester resin 100 g of the above linear polyester resin was heated to 140°C, stirred, and the tetracarboxylic dianhydride listed in Table 2 was charged, and the tetracarboxylic dianhydride listed in Table 2 was heated under a nitrogen atmosphere at room temperature. After continuing stirring under the conditions (reaction time) shown, a side chain carboxy group-containing photosensitive polyester resin having the acid value listed in Table 2 was obtained. (3) Measurement of photosensitivity of photosensitive image forming materials (3)-1 Method for making photosensitive plate Prepare a solution by dissolving 4 g of the resin from (2) above in 96 g of cyclohexanone, and add to this solution.
0.2 g (5% by weight based on resin) of 2-benzoylmethylene-1-methyl-β-naphthothiazoline and 0.4 g (10% by weight based on resin)
A photosensitive composition containing a phthalocyanine pigment was prepared. This composition was coated with a flourer on a grained and anodized aluminum plate, and dried to produce a photosensitive plate having a photosensitive layer with a thickness of about 1 μm. (3)-2 Conditions for measuring photosensitivity A step wedge with a step height of 0.15 is brought into close contact with the photosensitive plate obtained in (3)-1 above, and a 1 m
The photosensitive plate was exposed for 15 seconds using a metal halide lamp (Idolfin 1000, manufactured by Iwasaki Electric Co., Ltd.) with an output of 1 KW installed in an adjacent position. Thereafter, this photosensitive plate was developed with a developer having the following composition, and the maximum number of insolubilized steps was defined as the photosensitivity.

[Table] (4) Evaluation of printing durability and oil sensitivity (ink receptivity) when a photosensitive image forming material is used as a printing plate A test pattern is printed on a photosensitive plate prepared in the same manner as in (3) above. A negative film was placed in close contact with the negative film, and a metal halide lamp with an output of 1KW (Idolfin 1000, manufactured by Iwasaki Electric Co., Ltd.) was placed 1 meter away from the film, and the exposure time was set to a sensitivity of 6. A printing plate was produced by developing with the same developer as in (3) above. The printing plate produced in this way was attached to a four-color lithographic printing machine, and printed using standard ink for lithographic printing under conditions similar to actual lithographic printing. and liposensitivity was evaluated.
Printing durability is evaluated by whether a print that is faithful to the original image can be obtained without thickening of halftone dots or plate skipping, etc., and oil sensitivity is evaluated by whether the print is clear and has no blurring or poor ink adhesion. The evaluation was made based on whether or not a clear image could be obtained. The contents and results of each of the above examples are summarized in Table 2.

【table】

【table】

【table】

[Table] Represents the number of equivalents of anhydride groups.

Claims (1)

[Claims] 1. General formula (In the formula, A represents a linear polyester structural unit containing a photosensitive unsaturated double bond adjacent to an aromatic nucleus in the main chain, and R ₁ represents a tetravalent organic group.) 1. A photosensitive image forming material developable with an aqueous alkaline developer, characterized in that the photosensitive layer contains a photosensitive polyester resin having the following properties. 2. The image forming material according to claim 1, wherein the photosensitive polyester resin has an acid value of 15 or more. 3. Image formation according to claim 1 or 2, wherein the dicarboxylic acid unit having a photosensitive unsaturated double bond adjacent to the aromatic nucleus is a unit represented by the following general formulas (1) to (7). material. (In the above general formulas (1) to (7), R ₂ and R ₂ ' each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxyl group having 1 to 4 carbon atoms, a halogen atom, or a nitro group. , R ₃ represents an alkylene group having 2 to 4 carbon atoms, l represents an integer of 1 to 5, and n
represents an integer of 1 to 4, and m represents an integer of 1 to 5. ) 4 The content of dicarboxylic acid units having a photosensitive unsaturated double bond adjacent to the aromatic nucleus is within the scope of claim 1.
The image forming material according to claim 1, 2 or 3, wherein the amount is 30 to 100 mol% of the total dicarboxylic acid units in the linear polyester structural unit represented by A in the general formula of claim 1. 5. The image according to claim 1, 2, 3, or 4, wherein the photosensitive layer is coated on a support having a roughened metal surface and is used as a printing plate. Forming material.