JPS62251739A - Photosensitive composition - Google Patents

Abstract

PURPOSE:To obtain a PS plate good in development allowance by coating a support with a photosensitive composition dissolved or dispersed in a specified mixture of organic solvents and drying it. CONSTITUTION:The mixture of the organic solvents to be used for the photosensitive composition comprises the organic solvents of groups i-iv or groups i and ii, and group iv, and group iv weights 0.05-3wt% of the total weight of all the solvents. Each of group i has a boiling point of 40-100 deg.C, embodied by methanol, ethanol, and the like, each of group ii has a boiling point of 100-140 deg.C, embodies by n-butanol, isobutanol or the like; each of group iii has a boiling point of 140-210 deg.C, embodied by methyl n-amyl ketone, metyl n-hexyl ketone or the like; and each of group iv has a boiling point of >=210 deg.C, embodies by ethylene glycol monophenyl ether of the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fast-drying positive-working photosensitive composition suitable for continuous coating.

[Conventional technology]

A photosensitive composition is generally prepared by applying a solution dissolved or dispersed in an organic solvent onto the surface of a support such as aluminum, paper, plastic, S0□/Sj wafer, etc. that has been subjected to an appropriate surface treatment, and drying. used.

When applying and drying this photosensitive composition, the selection of an organic solvent is an important issue in order to fully demonstrate the performance of the photosensitive composition and to ensure economic efficiency and safety.

As an example of using a mixture of organic solvents having a boiling point of 210°C or higher, JP-A-60-24545 describes an alkali-soluble novolak resin and a 1,2-quinonediazide compound having a boiling point of 60 to 170°C. It is characterized by being dissolved in a mixed solvent in which a certain organic solvent and an organic solvent a3) having a boiling point of 180 to 350°C are mixed in a ratio of 50150 to 99/1 (weight ratio). Although a positive photosensitive composition is described, this refers to a positive photosensitive resin composition that is made from an alkali-soluble novolak resin and has extremely small striations after being spin-coated onto a substrate such as a silicon wafer. The purpose of this is to suppress drying during spin coating by adding a high boiling point solvent. Therefore, it is completely different from the present invention, which aims at continuous application and simple drying, and on the contrary requires a long drying time.

[Problem that the invention seeks to solve]

Particularly when industrially manufacturing photosensitive planographic printing plates (hereinafter referred to as "PS plates"), when a strip-shaped support is conveyed and coated and dried continuously, it is necessary to avoid increasing the length and complexity of the drying equipment. In order to ensure economic efficiency, it is necessary to dry in a short time. For this purpose, it is necessary to use a large amount of a low to medium boiling point solvent, but when a positive photosensitive composition is coated and dried with a low to medium boiling point solvent, development tolerance, which is an important performance for a PS plate, is It was found that the range was reduced.

Therefore, an object of the present invention is to provide a photosensitive composition that can be coated onto a support and then dried to obtain a PS plate with good development tolerance.

Another object of the present invention is to provide a photosensitive composition that can be dried in a short time after coating on a support to obtain a PS plate with good development tolerance.

Still another object of the present invention is to provide a photosensitive composition that can be coated onto a support and then dried using simple equipment to obtain a PS plate with good development tolerance.

[Means for solving problems]

As a result of our earnest efforts to solve the above-mentioned problems, the present inventors applied a photosensitive composition dissolved or dispersed in a specific mixed organic solvent and dried it to improve its performance as a lithographic printing plate. The present inventors have discovered that the present invention can be fully utilized, and have completed the present invention.

That is, the present invention covers the following groups (1), (ii), and (2).
and organic solvents of group (i), group (ii), and group (ii), wherein the components of the first group are in the range of 0.05 to 3% by weight based on the total weight of all organic solvents. A photosensitive composition characterized by the following.

(However, group (1) is an organic solvent with a boiling point in the range of 40°C or more and less than 100°C, group (11) is an organic solvent with a boiling point in the range of 100°C or more and less than 140°C, and ω group is an organic solvent with a boiling point in the range of 140°C or more. (Group 0 is an organic solvent having a boiling point of 210°C or higher.) The present invention will be described in detail below.

Supports used for PS plates and the like are dimensionally stable plate-like materials, and include those that have been used as supports for printing plates up to now, and can be suitably used. Such support and special holidays include paper, plastics (e.g. polyethylene,
Paper laminated with polypropylene, polystyrene, etc., e.g. aluminum (including aluminum alloys)
, metal plates such as zinc, iron, copper, etc., such as cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate acetate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal. Examples include plastic films such as those mentioned above, metal laminates or vapor-deposited paper or plastic films as mentioned above, and aluminum plates are particularly preferred. Aluminum plates include pure aluminum and aluminum alloy plates. Various aluminum alloys can be used, such as silicon,
An alloy of aluminum and metals such as copper, manganese, magnesium, chromium, zinc, lead, bismuth, and nickel is used. These compositions contain some iron and titanium as well as other negligible impurities.

The support is surface-treated as necessary. For example, in the case of a photosensitive lithographic printing plate, the surface of the support is subjected to a hydrophilic treatment. There are various types of such hydrophilic treatment. For example, in the case of a support having a plastic surface, so-called surface treatment methods such as chemical treatment, electric discharge treatment, flame treatment, ultraviolet treatment, high frequency treatment, glow discharge treatment, activated plasma treatment, laser treatment, etc. (for example, US Pat. 2.76
No. 4.520, No. 3.497.407, No. 3.145
．． No. 242, No. 3.376, No. 208, No. 3.072.
No. 483, No. 3.475.193, No. 3.360.4
48, British Patent No. 788.365, etc.), and there are those in which a subbing layer is applied to the plastic after these surface treatments.

A variety of coating methods have been developed, including a multilayer method in which the first layer is a hydrophobic resin layer that adheres well to plastic and has good adhesion, and the second layer is a hydrophilic resin layer. There is a single layer method in which a layer of resin containing hydrophobic groups and parent wood groups is applied in the same polymer.

In addition, in the case of a support having a metal surface, especially aluminum, surface treatments such as graining treatment, immersion treatment in an aqueous solution of sodium silicate, potassium fluorozirconate, phosphate, etc., or anodization treatment are performed. Preferably.

Prior to graining the aluminum plate, if necessary, the surface may be pretreated to remove rolling oil from the surface and expose a clean aluminum surface. For the former, solvents such as trichlene, surfactants, etc. are used.

For the latter, a method using an alkaline etching agent such as sodium hydroxide or potassium hydroxide is widely used.

Mechanical, chemical, and electrochemical methods are all effective as the graining method.

Mechanical methods include ball polishing method, blast polishing method,
There is a brush polishing method in which a water-dispersed slurry of an abrasive such as pumice is rubbed with a nylon brush, and chemical methods include polishing with an aluminum salt of mineral acid as described in JP-A No. 54-31187. A method of immersion in a saturated aqueous solution is suitable, and a preferred electrochemical method is alternating current electrolysis in an acidic electrolyte such as hydrochloric acid, nitric acid or a combination thereof. Among these surface roughening methods, a surface roughening method that combines mechanical roughening and electrochemical roughening as described in Japanese Patent Application Laid-open No. 55-137993 is particularly suitable for oil-sensitive images. It is preferable because it has strong adhesive strength to the support.

Graining by the method described above is preferably carried out in such a range that the center line surface roughness (Ha) of the surface of the aluminum plate is 0.3 to 1.0 μ.

The thus grained aluminum plate is washed with water and chemically etched as required.

The etching solution is usually selected from aqueous base or acid solutions that dissolve aluminum. In this case, it is necessary that no film different from aluminum derived from the etching solution components is formed on the etched surface. Examples of preferred etching agents include basic substances such as sodium hydroxide, potassium hydroxide, trisodium phosphate, disodium phosphate, tripotassium phosphate, and dipotassium phosphate; acidic substances such as sulfuric acid and persulfuric acid. , phosphoric acid, hydrochloric acid, and their salts, but salts of metals having a lower ionization tendency than aluminum, such as zinc, chromium, cobalt, nickel, copper, etc., are not preferred because they form an unnecessary film on the etched surface.

These etching agents have a dissolution rate of 0.3 g/ml to 40 g/ml per minute of immersion time for the aluminum or alloy used, depending on the concentration and temperature settings.
It is most preferable to carry out the process as follows, but it may be more or less than this.

Etching is carried out by immersing the aluminum plate in the above-mentioned etching solution or applying the etching solution to the aluminum plate, and the etching amount is 0.5 to log/
It is preferable that the process be performed so as to fall within the range of m'.

As the above-mentioned etching agent, it is desirable to use an aqueous base solution because of its high etching rate. In this case, since smut is generated, desmut processing is usually performed. Acids used for desmutting include nitric acid,
Sulfuric acid, phosphoric acid, chromic acid, butic acid, hydrofluoric acid, etc. are used.

The etched aluminum plate is washed with water and anodized if necessary. Anodic oxidation can be performed by methods conventionally practiced in this field. Specifically, sulfuric acid, phosphoric acid, chromic acid, oxalic acid, sulfamic acid,
When a direct or alternating current is passed through aluminum in an aqueous or non-aqueous solution containing benzenesulfonic acid or the like or a combination of two or more thereof, an anodic oxide film can be formed on the surface of the aluminum support.

The processing conditions for anodic oxidation vary depending on the electrolyte used and cannot be determined unconditionally, but generally the electrolyte concentration is 1 to 80% by weight, the solution temperature is 5 to 70°C, and the current density is 0.
．． Appropriate ranges are 5 to 60 amperes/dm', voltage 1 to 100 cm, and electrolysis time 30 seconds to 50 minutes.

Among these anodizing treatments, the British Patent No. 1.
412.768 and U.S. Pat. No. 3.511.
．． The method described in No. 661, in which phosphoric acid is used as an electrolytic bath for anodic oxidation, is preferred.

The aluminum plate roughened as described above and further anodized may be subjected to a hydrophilic treatment if necessary. Preferred examples thereof include US Pat. No. 2,714.066 and US Pat. No. 3,11111. Alkali metal silicates such as aqueous sodium silicate solutions as disclosed in U.S. Pat.
There is a method of treatment with polyvinylphosphonic acid as disclosed in US Pat. No. 153.461.

If desired, a photoreceptor-free layer can be applied to the aluminum plate treated as described above. Examples of these include gum arabic, carboxymethyl cellulose, carboxyethyl cellulose, carboxymethyl hydroxyethyl cellulose, alginic acid, polyacrylic acid, acrylic acid derivatives, condensation copolymers of vinyl methyl ether and maleic anhydride, vinyl acetate and maleic anhydride. copolymers with and their salts and water-soluble metal salts (
Mention may be made, for example, of zinc acetate) or yellow dyes, amine salts and fine particles of silica, titanium dioxide, and the like.

A layer of photosensitive composition is provided on the aluminum support thus treated. The photosensitive composition used in the present invention is preferably a positive photosensitive composition containing an 0-quinonediazide compound, and further containing an 0-quinonediazide compound and a phenolic resin.

The 0-quinonediazide compound used in the present invention is a compound having at least one 0-quinonediazide group, and its alkali solubility is increased by active irradiation, and examples of such compounds include compounds with extremely various structures. be able to. Examples of such O-quinonediazide compounds are described in John Wiley & Cosar, "Light-Sensitive Systems J".
S, Inc.), pages 339-352. Particularly suitable are sulfonic acid esters or sulfonamides of O-quinonediazide reacted with various aromatic polyhydroxy compounds or amines. Among such 0-quinonediazide compounds, Japanese Patent Publication No. 43-28
Benzoquinone (1,
2) - Ester of diazidesulfonic acid chloride and polyhydroxyphenyl or naphthoquinone - (1,2)
Most preferred are esters of -diazide sulfonic acid chloride and pyrogallol-acetone resin. Other suitable 0-quinonediazide compounds include U.S. Pat.
Benzoquinone-(1,2)-diazide sulfonic acid chloride or naphthoquinone-(1,2)-diazide sulfonic acid chloride described in No. 46.120 and No. 3.188.210.
2) - There is an ester of diazide sulfonic acid chloride and phenol formaldehyde resin. Other useful 0-quinonediazide compounds used in the present invention include:
Examples include those reported and known in numerous patents. For example, JP-A-47-5303, JP-A-48-6
No. 3802, No. 63803, No. 48-63, No. 48-96
No. 575, No. 49-38701, No. 133-1973
No. 54, No. 11222, No. 1122, No. 9610, No. 45
No. 49-17.481, U.S. Patent Nos. 2 and 7
No. 97.213, No. 3.454.400, No. 3.
No. 544.323, No. 3.573.917, No. 674.495, No. 3, 785.825, British Patent No. 1.227.602, No. 1, 251.345
No. 1.267, 005, No. 1.329.88
No. 8, No. 1.330.932, German Patent No. 854
．． Examples include those described in various specifications such as No. 890.

The phenolic resin used in the present invention refers to a novolak resin and a polyvinyl compound having a phenolic hydroxyl group, and the novolak resin is a resin obtained by condensing phenols and formaldehydes in the presence of an acidic catalyst. Also includes those modified with mesitylene. Representative examples of such novolac resins include phenol-formaldehyde resin, talesol-formaldehyde resin, phenol-cresol-formaldehyde resin, p-tert-butylphenol-formaldehyde resin, and phenol-modified xylene-11 resin.

Examples of the polyvinyl compound having a phenolic hydroxyl group include polyhydroxystyrene polymers and copolymers thereof, and halogenated polyhydroxystyrene polymers and copolymers.

The amount of 0-quinonediazide compound in the total photosensitive composition is 1
It is 0 to 50% by weight, more preferably 20 to 40% by weight. The amount of the phenolic resin blended is 45 to 79% by weight, preferably 50 to 70% by weight, based on the total photosensitive composition.

The positive-working photosensitive composition used in the present invention includes dyes for image identification, such as crystal violet, methyl violet, malachite green, tsuksin, baratushin, Victoria Blue B! ((Manufactured by Hodogaya Chemical Industry), Victoria Vinier Blue, 8011 (
[manufactured by Hodogaya Chemical Industry], Oil Blue #603 (manufactured by Orient Chemical Industry), Oil Pink #312 (manufactured by Orient Chemical Industry ■)
Orient Chemical Co., Ltd.), Oil Red 5B (Orient Chemical Co., Ltd.), Oil Green #502C Orient Chemical Co., Ltd.), etc., alone or in combination, in an amount of 0.3 to 15% by weight based on the total photosensitive composition. It is preferable to add

Furthermore, compounds that interact with these dyes to generate photodecomposition products that change the color tone, such as JP-A-50-3
○-naphthoquinone diazido 4 described in Publication No. 6209
-Sulfonic acid halogenides, trihalomethyl-2-pyrones and trihalomethyltriazines described in JP-A No. 53-36223, various 〇-naphthoquinonediazide compounds described in JP-A-55-62444, JP-A-55 −
A 2-trihalomethyl-5-aryl-1,3,4-oxadiazole compound described in Japanese Patent No. 77742, etc. can be added. These compounds can be used alone or in combination, and the amount added is preferably 0.3 to 15% by weight.

Sensitivity can be increased by adding an acid anhydride compound described in JP-A-52-80022 to the composition of the present invention.

These photosensitive composition components may contain a fluorosurfactant for the purpose of further improving coating properties.

Preferred fluorosurfactants include (1) having 3 to 20 carbon atoms and containing 40% by weight or more of fluorine;
(ii) poly(oxyalkylene) acrylates; (ii) poly(oxyalkylene) acrylates; or a copolymer with poly(oxyalkylene) methacrylate, in which one unit of Rf group-containing acrylate or Rf group-containing methacrylate monomer is 10 to 70% by weight based on the weight of the copolymer; By using such a fluorosurfactant, a uniform photosensitive layer can be provided even if a large amount of a low boiling point solvent is used.

The fluoroaliphatic group Rf is a saturated and generally monovalent aliphatic group. It can be straight-chain, branched and, if sufficiently large, cyclic or combinations thereof (eg alkylcycloaliphatic groups). The fluoroaliphatic backbone chain may contain chain oxygen and/or trivalent nitrogen heteroatoms bonded only to carbon atoms, which provide a stable bond between the fluorocarbon groups and provide a stable bond between the fluorocarbon groups and the Rf group. does not interfere with the inert properties of In order to exhibit a sufficient effect, the Rf group must have 3 to 20, preferably 6 to 12 carbon atoms, and contain 40% by weight or more, preferably 50% by weight or more of fluorine bonded to the carbon atoms. It is something that you have. At least three terminal carbon atoms of the Rf group are fully fluorinated. The terminal of the Rf group is, for example, CF, (:F, CF,
-, and a preferred Rf group is a substantially fully or fully fluorinated alkyl group, such as CnF2R+1 (" is an integer greater than or equal to 3).

If the fluorine content of the Rf group is less than 40% by weight, the improvement in coating properties is insufficient. The effect is greater when the fluorine atom is localized at the end of the Rf group. Even if the number of carbon atoms in the Rf group is 2 or less, the fluorine content can be increased, but the total amount of fluorine atoms will be insufficient and the effect will be weak. The fluorine content in the copolymer can be increased by increasing the ratio of a fully fluorinated Rf group-containing monomer having 2 or less carbon atoms to the copolymer (even if the fluorine atoms are localized). Because it is not fully developed, sufficient effects cannot be obtained.

On the other hand, when the number of carbon atoms in the Rf group is 21 or more, when the fluorine content is high, the resulting copolymer has low solubility in a solvent (and when the fluorine content is low, the localization of fluorine atoms becomes low). It's not enough and you can't get the full effect.

The solubilizing moiety in the copolymer is a poly(oxyalkylene) group, (PR')X, where R' is an alkylene group having 2 to 4 carbon atoms, such as -CH2CH2-l-CH2
CII2CH2-1-CH(C11,) CH2-1 or -C)l(CH3)CH(CH,)- is preferred. The oxyalkylene units in the poly(oxyalkylene) group may be the same as in poly(oxypropylene), or two or more different oxyalkylenes may be randomly distributed. Often straight or branched oxypropylene and oxyethylene units, or may be present as blocks of straight or branched oxypropylene units and blocks of oxyethylene units. . The poly(oxyalkylene) III can include one or more chain bonds (e.g., mediated or included; if the chain bonds have a valence of three or more, it is a branched chain provides a means for obtaining oxyalkylene units of

In addition, when adding this copolymer to a photosensitive composition, in order to obtain the desired solubility, poly(oxyalkylene)
The appropriate molecular weight of the group is 250 to 2,500.

The copolymer used in the present invention includes, for example, fluoroaliphatic group-containing acrylate or fluoroaliphatic group-containing methacrylate, poly(oxyalkylene)acrylate or poly(oxyalkylene)methacrylate,
For example, they can be prepared by free-radically initiated copolymerization with monoacrylates or diacrylates or mixtures thereof. The molecular weight of polyacrylate oligomers can be adjusted by adjusting the concentration and activity of the initiator, monomer concentration and polymerization reaction temperature, and by adding chain transfer agents, such as thiols, such as n-octyl mercaptan. . - by way of example, acrylates containing fluoroaliphatic groups, Rf-R'-02C-CH=CL (where R' is, for example, sulfonamidoalkylene, carbonamidoalkylene or alkylene), such as C,F,
,SO,N(C,H9)CH2CH,0□CCll=C
H is poly(oxyalkylene) monoacrylate CH,
When copolymerized with =CHC(0) (OR'), OCH, a copolymer having the following repeating units is obtained.

+CH2-CH+ +CH2-[:If
toe. '=Oc=.

□ (UR'), 110
11'C:')l, R.

The above fluoroaliphatic group-containing acrylate is disclosed in U.S. Pat.
．． 803.615, 2.642.416, 2, 826.564, 3.102.103, 3.282.905 and 3.304,278
listed in the number. The poly(oxyalkylene) acrylates used in the preparation of the above copolymers, and other acrylates useful for this purpose, are commercially available hydroxypoly(oxyalkylene) materials, such as under the trade name "Pluronic" (Asahi Denka Industrial ■)〕
, ADEKA Polyether (manufactured by Asahi Denka Kogyo ■), “Carbowax” (manufactured by: Carbowax (Glyco Products) Co.)
], “Toriton”
n (Rohm and H
(manufactured by Dai-ichi Kogyo Seiyaku ■)] and P, Machi G (manufactured by Daiichi Kogyo Seiyaku ■) by reacting them with acrylic acid, methacrylic acid, acrylic chloride, or acrylic anhydride in a known manner. can. Separately,
Po IJ (oxyalkylene) diacrylate produced by a known method, CI (2=CHCO2(R'O), C0CH=CH2
, for example, CL・CHCfL (C2H40) + a
(C3HsO) 22 (C2H4D) +oCOCH
When =C)lx is copolymerized with the above-mentioned fluoroaliphatic group-containing acrylate, a polyacrylate copolymer having the following repeating units is obtained.

(OR')
U.S. Patent No. 2.592.069, U.S. Patent No. 2,995.5
No. 42, No. 3.078.245, No. 3.081.
No. 274, No. 3,291.843 and No. 3.32
No. 5.163, ethylenically unsaturated materials suitable for preparing the terminal ethylenically unsaturated monomers containing fluoroaliphatic groups are described in U.S. Pat.
listed in the number.

Preferred copolymers for use in the present invention are copolymers of fluoroaliphatic group-containing acrylates or fluoroaliphatic group-containing methacrylates and poly(oxyalkylene) acrylates or poly(oxyalkylene) methacrylates, wherein the fluoroaliphatic It contains 10 to 70% by weight of one unit of the group group-containing monomer based on the weight of the oligomer. If the amount of one unit of the fluoroaliphatic group-containing monomer is less than 10% by weight, the effect will not be sufficient, and if it is more than 70% by weight, the solubility in the solvent will be too low, which is undesirable. The molecular weight of the copolymer used in the present invention is 2,500 to 100.
000 is preferred; if it is less than 2,500, the effect will not be sufficient, and if it is more than 100,000, the solubility in solvents will decrease, which is not preferred.

Among these copolymers, 50 to 100% by weight of fluoroaliphatic group-containing acrylate is used as the fluoroaliphatic group-containing upper polymer based on one unit of the fluoroaliphatic group-containing monomer, and poly(oxyalkylene) Those obtained by using 15% by weight or more of acrylate monomer unit based on the total weight of the copolymer are preferred, and copolymers of fluoroaliphatic group-containing acrylate and poly(oxyalkylene) acrylate are particularly preferred. When the fluoroaliphatic group-containing methacrylate is 50% by weight or more based on one unit of the fluoroaliphatic group-containing monomer, the solvent solubility decreases. In addition, when the poly(oxyalkylene) acrylate monomer is less than 15% by weight based on the total weight of the copolymer,
Pinholes are more likely to occur in the paint film.

The preferred range of use of these fluorosurfactants is 0.01 to the photosensitive composition (coating components excluding solvent).
-5% by weight, and a more preferable usage range is 0.5% by weight.
It is in the range of 0.05 to 3% by weight.

If the amount of fluorosurfactant used is less than 0.01% by weight, the effect will be insufficient, and if it is more than 5% by weight, the coating film may not dry sufficiently or the performance as a photosensitive material (for example, (Developability) is adversely affected.

- In addition, fillers and plasticizers such as dibutyl phthalate, butyl glycolate, tricresyl phosphate, and dioctyl adipate may be added to the composition of the present invention to improve the physical properties of the coating film. Various additives can be added. Adding a filler not only makes it possible to further improve the physical properties of the coating film (but also makes it possible to make the surface of the photosensitive layer matte, which improves vacuum adhesion during image printing and eliminates so-called printing blur). Such fillers include talc powder, glass powder, clay, starch, wheat flour, corn flour, Teflon powder, and the like.

The photosensitive composition of the present invention is prepared by dissolving or dispersing each of the above-mentioned components in a mixture of the following organic solvents, and is used by coating the composition on the support and drying it.

Specific examples of organic solvents of group (i) with a boiling point in the range of 40°C or more and less than 100°C include: Methyl alcohol 64.5°C Ethyl alcohol 78.3°C n-propyl alcohol 97.2°C Iso-propyl alcohol 82 .3℃ unibutyl alcohol
99.5℃ acetone 56.
2℃ Methyl ethyl ketone 79.6℃ Benzene 80.1℃ Cyclohexane 80.7℃ Methyl acetate
57.8℃ ethyl acetate
? ? , 1 t: iso-propyl acetate
89℃ Ethyl formate 54.3
°C Propyl formate 81.3 °C Isobutyl formate 98 °C Methyl propionate 79.7 °C Ethyl propionate
99.1℃chloroform
61.2℃ Carbon tetrachloride 76.7
°C Methylene dichloride 40.4 °C Ethylene dichloride 83.5 °C 1.1.1-)
Lichloroethane 74℃ isopropyl ether
68.3°C Tetrahydrofuran 6
Examples include tetrahydropyran at 6°C, ethylene glycol dimethyl ether at 85.2°C, and the like.

Boiling point is in the range of 100°C or more and less than 140°C (ii)
A specific example of the organic solvent in this group is n-butyl alcohol.
117.7℃iso-butyl alcohol
107.9°C Methyl n-propyl ketone 103.
3℃ Methyl n-butyl ketone 127.5℃ Methyl iso-butyl ketone 115.9℃ Diethyl ketone 102.2℃ Toluene
110.6℃ m-xylene
139.1°C p-xylene 138
．． 4℃ n-propyl acetate 101.6℃ n-butyl acetate 126.5℃ iso-acetate
Butyl Unibutyl acetate 118.3℃
112.5℃ n-butyl formate
l O6,8℃ amyl formate 1
30.4℃ Methyl butyrate 102.3
°C Ethyl butyrate 121.3 °C Monochlorobenzene 131.5 °C Dioxane
Examples include 101.3°C ethylene glycol monomethyl ether 124, 4°C ethylene glycol monoethyl ether 134, 8°C ethylene glycol diethyl ether 121, 1°C propylene glycol monomethyl ether 120°C.

Specific examples of organic solvents of the (to) group with a boiling point in the range of 140°C or higher and lower than 210°C include methyl n-amyl ketone, 150.2°C methyl n
-hexyl ketone 172.9-173.5℃ ethyl n
-Butyl ketone 147.8°C Di-n-propyl ketone 143.7°C Diiso-butyl ketone
168.1℃ acetylacetone
140℃ Cyclohexanone 155.7℃
Methylcyclohexanone 169-170.5 °C Diacetone alcohol 167.9 °C Acetonylacetone 192-194 °C 0-xylene
144.4℃ n-amyl acetate
147.6℃isoamyl acetate
142.5°C Methyliso-amyl acetate 146.
3℃ Methoxybutyl acetate 173℃ Seconic hexyl acetate 146.3℃ 2-ethylbutyl acetate 162.4℃ Cyclohexyl acetate
173.5-174.5℃ Methyl acetoacetate
169.5℃ Ethyl acetoacetate 1
80.8℃ n-butyl propionate 145.4
°C n-butyl butyrate 166.4 °C Isoamyl butyrate 184.8 °C n-butyl ether 142 °C 2-ethoxytetrahydropyran 147 °C ethylene glycol monomethyl ether acetate)
1 4 5. 1℃ ethylene glycol monoethyl ether acetate)
1 5 6
．． 4℃ Ethylene glycol monoisopropyl ether 139-143℃ Ethylene glycol monobutyl ether j, 71.2
°C ethylene glycol monoiso-butyl ether 160,
5℃ ethylene glycol monobutyl ether acetate)
1
91.5℃ ethylene glycol isoamyl ether 1
81°C Ethylene glycol monohexyl ether 208, 1°C Ethylene glycol monoacetate) 182°C Ethylene glycol diacetate 190.2°C Methoxymethoxyethanol 167.5°C Diethylene glycol monomethyl ether 194, 2°C Diethylene glycol monoethyl ether 201, 9°C Diethylene glycol dimethyl ether 162℃ diethylene glycol methyl ethyl ether 170-180
℃ Diethylene glycol diethyl ether 188, 9℃ Diethylene glycol monoisopropyl ether
2 0 7.
3℃Propylene glycol 188.2℃Propylene glycol monomethyl ether acetate
1 4 5. 4 °C Propylene glycol monoethyl ether acetate Propylene glycol monobutyl ether 171, 1 °C Dipropylene glycol monomethyl ether 190 °C Cyfrobylene glycol monoethyl ether 197, 8
℃ Dibropylene glycol dimethyl ether dipropylene glycol methyl ethyl ether dipropylene glycol jetyl ether hequinlene glycol 1
97.1°C 3-methoxy-3-methoxybutanol 17
4°C N,N-dimethylformamide 149.6°C Dimethyl sulfoxide 189°C T-butyrolactone
203-204℃ γ-valerolactone
Examples include 205 to 207°C.

Specific examples of organic solvents in the ω group with a boiling point of 210°C or higher include ethylene glycol monophenyl ether 244, 7°C ethylene glycol monophenyl ether acetate -
to
2 5 9. 7°C Ethylene glycol benzyl ether 256°C Ethylene glycol butyric acid monoester 220°C Ethylene glycol propionic acid diester 210, 3°C Ethylene glycol butyric acid diester 240°C Diethylene glycol monomethyl ether acetate Diethylene glycol monoethyl ether acetate -
to
2 1? , 4℃ diethylene glycol monobutyl ether 230, 4℃ diethylene glycol monoisobutyl ether 220℃ diethylene glycol monobutyl ether acetate -
to
2 4 6. 8°C diethylene glycol dibutyl ether 254, 6°C diethylene glycol monoacetate diethylene glycol diacetate 250°C dipropylene glycol monoethyl ether acetate triethylene glycol monomethyl ether 249°C triethylene glycol monoethyl ether 255, 9
°C Triethylene glycol monobutyl ether 271,2
°C Triethylene glycol dimethyl ether 216 °C Triglycol dichloride 240.9 °C 1-Butoxyethoxypropanol 229.4 °C Tripropylene glycol heptafluoromethyl ether 243 Tetraethylene glycol dimethyl ether 275,3
Examples include ℃.

When selecting and using one organic solvent from groups (ii) to (ii) among the organic solvents in each of the above groups, select an organic solvent from each group in which the other photosensitive composition components are easily soluble. have to choose. However, when selecting two or more types of organic solvents from one group, it is sufficient that the other photosensitive composition components are readily soluble in at least one type of the group; , preferably has the highest boiling point among the selected ones. Since the organic solvents of group (i) evaporate earlier than the organic solvents of groups (ii) to (e) during drying, there are no restrictive conditions.

Examples of the solvent in which the photosensitive composition is easily soluble include ketones, esters, ethylene glycol (or propylene glycol) mono(C5-C2) alkyl ether or diethyl ether in group (ii);
Ketones, ethylene glycol (or propylene glycol) mono(01-C2) alkyl ether are preferred, and methyl isobutyl ketone and brobylene glycol monomethyl (or ethyl) ether are most preferred.

Also in this group, ketones, ethylene glycol (or propylene glycol) mono(C3-Cs) alkyl ether, mono(01-C1) alkyl ether acetate, diethylene glycol (or dipropylene glycol) mono(CI=Cs) alkyl ether, (
C+ to C2) Alkyl ether, methyl ethyl ether, N,N-dimethylformamide, dimethyl sulfoxide, T-butyrolactone, etc., acetylacetone, cyclohexanone, diacetone alcohol, ethylene glycol mono(C1 to C4) alkyl ether acetate , diethylene glycol (or dipropylene glycol) di(C, to C2) alkyl ether or methyl ethyl ether, N,N-dimethylformamide, dimethyl sulfoxide, r-butyrolactone are preferred.

Furthermore, in the group ■, derivatives of polyhydric alcohols (ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, tetraethylene glycol), namely monoalkyl ethers, monoalkyl ether esters (especially monoalkyl ether acetates) ),
Mention may be made of dialkyl ethers, monoesters, and diesters.

The mixing ratio of the solvents used in the present invention is based on the weight of all solvents used, and the total amount of solvents in each group is 20 to 70% by weight for group (2) to 70% by weight for group (11), and 10 to 79% by weight for group (11). The weight ratio is 0 to 30% by weight for the (total) group, and 0.05 to 3% by weight for the head group.

The boiling point of the solvents in group (1) is 40°C or more and less than 100°C, but solvents with a temperature of less than 40°C require cooling during application, making production difficult. Further, the larger the amount of group (i) solvent used, the less the drying load of the composition will be, but the drying will be rapid, making it difficult to obtain a uniform film thickness.

If the content of group (i) is less than 20% by weight, the drying load will be too large, and if it is more than 70% by weight, it will be difficult to obtain a uniform film thickness. When using a large amount of group (i), it is preferable to add a fluorosurfactant as described above.

(The boiling point of the ω group solvent is 100°C or more and less than 140°C, but the amount used is 10 to 79% by weight, and if it is less than 10% by weight, the drying load will be large when the amount of group (i) is insufficient. On the other hand, if the amount of group (i) is sufficient, sufficient performance will not be obtained due to the rapid change in solvent composition from the fi1 group to the (conversion) group.Also, if the amount is 79% by weight or more, the drying load will become large. Too much.

The boiling points of the solvents in group (2) are 140° C. or higher and lower than 210° C., but this group can be added if necessary. The amount used is 0 to 30% by weight, but if it exceeds 30% by weight, the drying load becomes too large. Generally (2)
Among the group, those with low boiling points (140-180℃) can be used in large quantities, but conversely those with high boiling points (180℃) can be used in large quantities.
~210°C) is preferably used in a small amount (0 to 5% by weight).

■The boiling point of group solvents is 210℃ or higher, but the amount used is
It is 0.05 to 3% by weight. If it is less than 0.05% by weight, the effect will not be sufficient, and if it is more than 3% by weight, the drying load will become large or a large amount of solvent will remain after drying.

When the photosensitive composition of the present invention is rapidly dried after coating, the drying load is small and sufficient performance can be obtained after drying. This is considered to be because the drying is performed with appropriate changes in the solvent composition ratio, so that a more uniform photosensitive film can be obtained after drying.

The photosensitive composition of the present invention is dissolved or dispersed at a solid content concentration of 2 to 50% by weight, coated on a support, and dried.

Application methods include roll coating, reverse roll coach ink, tip coating, air knife coating, gravure coating, gravure offset coating, hopper coach ink, flade coating, rod coating, wire doctor coating, spray coating, curtain coating,
Methods such as extrusion-ting are used, especially at 10-/m
A coating liquid amount range of '~100 mp/m' is suitable.

Drying is done with heated air. Heating is 30
The temperature range is preferably from 40°C to 140°C, particularly from 40°C to 140°C. In addition to a method in which the drying temperature is kept constant during drying, a method in which it is increased stepwise can also be implemented.

Also, good results may be obtained by dehumidifying the dry air. Heated air is placed at a distance of 0.1 m from the coating surface.
It is suitable to supply at a rate of 0.5 m/sec to 20 m/sec, particularly 0.5 m/sec to 20 m/sec.

〔Effect of the invention〕

The photosensitive composition of the present invention has a small drying load and can simplify drying equipment, and can fully exhibit performance such as development tolerance as a 25th plate.

Furthermore, the present invention is particularly effective in photosensitive lithographic printing plates obtained by conveying a strip-shaped support, continuously coating a photosensitive composition dissolved or dispersed in an organic solvent, and drying. It will be done.

〔Example〕

Hereinafter, the present invention will be explained in more detail based on examples. However, the present invention is not limited to these Examples. In addition, % in an example shows weight %.

Examples 1 to 7 and Comparative Examples a to d An aluminum strip having a thickness of 0.3 s and a width of 1.000 mm was transported and first passed through a 10% aqueous solution of tribasic sodium phosphate kept at 80°C for 1 minute. Then, the oil was removed. The surface was then grained using a nylon plan and 400 mesh of pumice water suspension, and thoroughly washed with water.

This plate was placed in a 25% aqueous sodium hydroxide solution at 45°C for 9
Dip for a second to perform etching, and after washing with water, add another 20%
It was immersed in nitric acid for 20 seconds and washed with water. The amount of etching on the grained surface at this time was approximately 8 g/m''.Next, this plate was coated with a DC anodic oxide film of 3 g/m'' using 7% sulfuric acid as an electrolyte at a current density of 15 A/dn+2. , washed with water, dried and led to the coating process.

In the coating process, the following coating liquids were prepared.

Composition of coating liquid (photosensitive composition) Ester compound of naphthoquinone-1,2-diazide-5-sulfonyl chloride and pyrogallol-acetone resin (Note 2)...0°80g Cresol-formaldehyde resin... ...2. OOgt
-7'Tylphenol-formaldehyde resin (Note ■)
...0.05 g Tetrahydrophthalic anhydride ...0.15
g Naphthoquinone-1,2-diazide-4-sulfonyl chloride...0.0
3g Oil Blue #6 (13 (Orient Chemical Industry ■
(manufactured by)...0.05 g Fluorine surfactant (Note ■)...0.0
1 g mixed solvent (Table 1) 34 g
Note ■ What is described in Example 1 in the specification of U.S. Patent No. 3.635.709 Note ■ What is described in the specification of U.S. Patent No. 4.123.279 ■ N-": jf Ruberfluorooctane sulfonamide ethyl acrylate CaF, ?SO,N(C,H9)CH,C)1.0cO
cH=c)12 50% poly(oxyalkylene)acrylate C)! ,0(,C2)140)tcOc)l=
c) 50% of 12 (copolymer, molecular weight 20,000) The above coating solution was continuously applied onto grained aluminum strips at a rate of 30 g/m', and then heated in a hot air drying zone at 100°C for 45 seconds. Alternatively, it was dried by passing for 1 minute to form a photosensitive layer.

In Table 1, the development tolerance is determined by printing a gray scale (manufactured by Fuji Photo Film) with a density difference of 0.15, and then developing it using the company's developer DP-4 (1:8) at 25°C for 30 seconds. and 5
Changes in the number of solid plates in minutes [time] and at 25°C for 1 minute (1:
8) and (1:6), the change in the number of solid throws [density] is calculated, and the lower the value, the wider the tolerance.

Comparative example d is a conventional technique. It can be seen that in Comparative Example C, which was dried for a short time, the development tolerance was deteriorated. On the other hand, in Comparative Examples, the development tolerance was poor even though a solvent with a low boiling point was used. It can be seen that Examples 1 to 7 of the present invention have improved development acceptability compared to Comparative Examples 1 and 2, despite the short drying time. However, Comparative Example a, in which a large amount of diethylene glycol monomethyl ether acetate of Group 1 was used, resulted in poor development tolerance. Also, Example 1~
No. 7 was coated on a lithographic printing plate and obtained good performance results.

Examples 8 to 10 In the same manner as in Examples 2 to 4, the molecular weight of the fluorosurfactant was 50,000, and a mixed solvent was applied with the composition shown in Table 2.
When dried, good results were obtained as in Examples 2-4.

Example 11.12 When a mixed solvent having the composition shown in Table 3 was applied and dried in the same manner as in Examples 1 to 7, an improvement in development tolerance was observed compared to the comparative example.

Examples 13-15 Group (1), group (ii),
Good results were obtained when mixed solvents having the compositions shown in Table 4 consisting of group (2) were used.

Claims (4)

[Claims] (1) The following groups (i), (ii), (iii), and (iv), or (i), (ii), and (
A photosensitive composition comprising an organic solvent of group iv), characterized in that the component of group (iv) ranges from 0.05 to 3% by weight, based on the total weight of all organic solvents. (However, group (i) is an organic solvent with a boiling point in the range of 40°C or more and less than 100°C, group (ii) is an organic solvent with a boiling point in the range of 100°C or more and less than 140°C, and group (iii) is an organic solvent with a boiling point in the range of 100°C or more and less than 140°C. (Group (iv) is an organic solvent whose boiling point is in the range of 210°C or higher.) (2) The organic solvent components of each group are based on the total weight of all organic solvents: (i) 20 to 70% by weight, (ii) 10 to 79% by weight, and (iii) 0 to 30% by weight. Claim No. (1) characterized in that the group (iv) is in the range of 0.05 to 3% by weight.
The photosensitive composition described in . (3) The photosensitive composition according to claim (1), which is a positive photosensitive composition containing an o-quinonediazide compound. (4) Claim No. 1, which is a positive photosensitive composition containing an o-quinonediazide compound and a phenolic resin.
The photosensitive composition described in .