JPH02141752A - Positive/negative type photosensitive planographic printing plate and production of planographic printing plate by using this plate - Google Patents

Abstract

PURPOSE:To obtain the visible image characteristic and sensitivity improved by a negative type processing by providing a photosensitive layer formed of a photosensitive compsn. which contains an orthoquinone diazide compd. and an alkali soluble resin and contains at least one kind of acidic dyes on a base. CONSTITUTION:The photosensitive layer formed of the photosensitive compsn. which contains the orthoquinone diazide compd. and the alkali soluble resin and contains at least one kind of the acidic dyes is provided on the base to form the positive/negative type photosensitive planographic printing plate. The photosensitive planographic printing plate is subjected to image exposing then to a heat treatment and after the entire surface of the photosensitive layer is exposed, the layer is developed by an aq. alkaline developing soln. The exposed visible image characteristic and sensitivity improved in the processing process for obtaining the negative type image are obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photosensitive lithographic printing plate that can be used for both positive and negative types, and a method for producing a 69th lithographic printing plate using the same.

[Prior Art] In the process of producing a printing planographic plate, it is widely practiced to use two types of photosensitive planographic printing plates, positive type and negative type, in combination. However, since the materials forming the photoreceptor are different between the positive-working photosensitive lithographic printing plate and the negative-working photosensitive lithographic printing plate, different developers must be used in the development processing of the two. Therefore, when both a positive type and a negative type are used together, there is a significant reduction in work efficiency due to the replacement of the developer in the developing device and the accompanying cleaning of the equipment.

To address the above-mentioned problems, techniques are known that allow one type of photosensitive lithographic printing plate to be used for both positive and negative types. Examples of such technology include, for example, the
A method of forming a negative image by a specific method from a photosensitive lithographic printing plate using a positive photosensitive composition containing orthoquinone diazide as disclosed in US Pat. That is, in this method, a photosensitive lithographic printing plate that can be image-exposed and then subjected to development processing to obtain a positive image is used, and after image-exposure is carried out in the same manner,
A negative image is obtained by successively performing heat treatment, full exposure, and further development with a positive developer.

However, the above-mentioned photosensitive lithographic printing plates that can be used for both positive and negative types lack clarity in so-called exposed visible image quality, which distinguishes exposed areas and unexposed areas during or after image exposure, and they also do not produce a negative image. It has the disadvantage of insufficient sensitivity in the processing steps used to obtain it.

In particular, in order to improve the above-mentioned exposure visibility, crystal violet (CI 425
55), Victoria Pure Blue BOH (C1425
Even in photosensitive lithographic printing plates containing organic dyes such as 95), the visible image exhibits a dull brownish color and is unclear after heat treatment in the process of forming the negative image and during the subsequent full exposure. In some cases, the particles may disappear or disappear, resulting in a decrease in work efficiency.

[Object of the Invention] An object of the present invention is to provide a photosensitive lithographic printing plate that can be used for both positive and negative types and has improved exposure visibility and sensitivity in the processing process for obtaining negative images. .

Another object of the present invention is a method for producing a lithographic printing plate that provides improved exposure visibility and sensitivity values in a method for producing a negative-working lithographic printing plate from a photosensitive lithographic printing plate that normally exhibits positive action. The goal is to provide the following.

[Structure of the Invention] The above-mentioned object of the present invention is to provide a photosensitive layer formed from a photosensitive composition containing an orthoquinone diazide compound and an alkali-soluble resin, and containing at least one acidic dye on a support. A photosensitive lithographic printing plate that can be used for both positive and negative types, and the photosensitive lithographic printing plate is subjected to a heat treatment after being exposed to light, and then after the entire surface of the photosensitive layer is exposed to light, an aqueous alkaline developer is applied. This is achieved by a method for producing a lithographic printing plate, which is characterized by developing with.

The present invention will be explained in detail below.

The orthoquinonediazide compound used in the present invention is a compound having at least one orthoquinonediazide group, preferably an orthobenzoquinonediazide group or an orthonaphthoquinonediazide group, and has various known structures, such as J. “Light-3c
nsitive system cmsJ (JohnWi
ley & 5ons, Inc., 1965), pages 339-353. Particularly suitable are esters or amides of various hydroxyl compounds or amino compounds with 1,2-quinonediazide-4-sulfonic acid or 1,2-quinonediazide-5-sulfonic acid, and 1,2-quinonediazide-4-sulfonic acid. Particularly preferred are ester compounds. Preferred hydroxyl compounds include synthetic resins of phenols and carbonyl group-containing compounds, particularly resins obtained by condensation in the presence of an acidic catalyst.

Examples of the phenols include phenol, resorcinol, cresol, pyrogallol, etc., and examples of the carbonyl group-containing compound include aldehydes such as formaldehyde and benzaldehyde, and ketones such as acetone.

Especially phenol/formaldehyde resin, cresol/
Formaldehyde resin, pyrogallol acetone resin,
Resorcinol benzaldehyde resin is preferred.

Typical specific examples of the orthoquinonediazide compound used in the present invention include benzoquinone-(1,2)-diazide sulfonic acid, naphthoquinone-(1,2)-diazide sulfonic acid, phenol/formaldehyde resin, or cresol/ ester with formaldehyde resin,
Naphthoquinone-(1,2)-diazide, a sulfonic acid ester of naphthoquinone-(1,2)-diazide sulfonic acid and pyrogallol aretone resin described in U.S. Patent Box 3.635.70'1 -(2) -Synthesate of 4-sulfonic acid and resorcinol benzaldehyde resin, nano-1 to quinone-(1,2)-diazide-(2)-4
- Ester compounds of sulfonic acid and resorcinol/birogallol/acetone copolycondensates or pyrogallol/acetone copolycondensates, and other useful orthoquinonediazide compounds include the terminal compound described in JP-A-50-117503. Polyester and ortho with hydroxyl groups.

Esters with naphthoquinonediazide sulfonic acid, p as described in JP-A-50-113305,
Examples include esters of homopolymers of hydroxystyrene or copolymers with other monomers copolymerizable therewith with orthonaphthoquinonediazide sulfonic acid, and esters of trihydroxybenzophenone and orthoquinonediazide sulfonic acid.

In the present invention, the content m of these orthoquinone diazide compounds is preferably 5 to 60% by weight, particularly preferably 10 to 50% by weight, based on the total solid content of the photosensitive composition.

Although at least one acidic dye is used in the present invention,
The acidic dyes include azo dyes, anthraquinone dyes,
Compounds belonging to carbonium dyes are preferred, and examples of such compounds include Orange I (CI 1
4600), Suminol Fast Red B (CI
1468G), Eisen Opal Blue 2GCH (
CI 14880), Roserin (C115620)
, Eisen Opal Blue BH (0115706), Solar Red S (CI 1 (3045), Eisen Bonseau RH (Cl 16150), Amaranth (CI 16185), Eisen Brilliant Scarlet 3 F +-1 (CI 16255), Resorcin Brown G (CI 2017G), Acid Anthracene Red G (CI 2289G>,
Acid Anthracene Red 3 B L (CI 2
391G), eosin (CI 4538G), Phloxin B (CI 45410), erythrosin (
CI 4543G), O's Bengal <C1454
40), Suminol Leveling Blue AGG (CI62
125), Alizarin Astrol B (CI 61)
530), Alizarin Cyanine Green G (0161
570), acid nylon fast violet 6B
(CI 6200G), Thiazid Light Blue 2
A (CI G2055), Alizarin Saf? Examples include Eol 5E (C163000), and preferred examples include Orange 11 Eosin, Phloxine B1 Alizarin Cyanine Green G, and the like.

The above acidic dye is 0.0% based on the total solid content of the photosensitive composition.
It is contained in a range of 1 to 10% by weight, preferably 0.1 to 4% by weight.

As mentioned above, a technique for obtaining a lithographic printing plate that can be used for both positive and negative types from a photosensitive lithographic printing plate made of a positive-working photosensitive composition is known. In these techniques, it was essential to add a basic substance to the photosensitive composition in order to obtain a negative image and a positive image from the same photosensitive printing plate, but surprisingly, the present inventors et al. discovered that the same objective could be achieved by adding an acidic dye other than the above-mentioned basic substance.

An alkali-soluble resin is used in the present invention.

Such a resin preferably contains 11 phenol groups, carboxyl groups, sulfonic acid groups, and phosphorus W! It is a compound having an alkali-soluble group such as an i group, and the alkali-soluble resin is preferably one obtained by condensing phenols and ketones or aldehydes in the presence of an acidic catalyst. Examples of the phenols include phenol, cresol, and p-fll rough phenol. Examples of the aldehydes include aretaldehyde and formaldehyde, with formaldehyde being preferred. Acetone is preferred as the ketone.

Preferred alkali-soluble resins include, for example, phenol-formaldehyde resin, cresol-formaldehyde resin, phenol-cresol-formaldehyde copolycondensate resin as described in JP-A-55-57841, and JP-A-55-127553. Copolycondensate resins of p-substituted phenol and phenol or cresol and formaldehyde, condensates of benzaldehyde and polyhydric phenols such as resorcinol-benzaldehyde resins, pyrogallol-benzaldehyde resins, and pyrogallol as described in publications. Examples include copolycondensates of polyhydric phenol and acetone such as -resorcinol-acetone resin, and xylenol-formaldehyde resin. The content m of these alkali-soluble resins is preferably 30 to 901 m% based on the total solid content of the photosensitive composition, particularly 5
0 to 85% by weight is preferred.

In addition to the materials described above, the photosensitive composition used in the photosensitive lithographic printing plate of the present invention can also contain the following additives, if necessary.

In other words, various low molecular weight compounds (e.g. phthalates, triphenyl phosphates, maleate esters, etc.) as plasticizers, surfactants (e.g. fluorine surfactants, ethyl cellulose polyalkylene) as coating properties improvers, etc. nonionic activators represented by ethers, etc.), acid anhydrides, etc. as sensitizers for positive photosensitive compositions. Furthermore, compounds that generate acid or free M groups upon exposure to light and interact with the wired dye to change the color tone of the dye can also be included. Compounds that generate acids or free radicals upon exposure to light include, for example, JP-A-50-36
0-Naphthoquinonediazide-4- described in Publication No. 209
Sulfonic acid halogenide, trihalomethyl-2-pyrone and trihalomethyl-triazine described in JP-A No. 53-36223, and orthonaphthoquinonediazide-4-sulfonic acid chloride described in JP-A-55-6244 and electron-withdrawing. Ester compounds with phenols or anilines having sexual substituents, JP-A-55-77742
Examples include halomethyl-vinyl-oxazole compounds and diazonium salts described in Japanese Patent Publication No. Although these compounds vary depending on their type, their addition m is generally 0.01 to 20% by weight based on the total solid content of the photosensitive composition.
, preferably 0.05 to 10% by weight.

The photosensitive lithographic printing plate of the present invention may further contain organic dyes as described below. That is, for example, Victoria Pure Blue BOH [Hodogaya Chemical] (CI 42'595
), 4 Il Blue #603 [manufactured by Orient Chemical Industry]
, Patent Pure Blue [manufactured by Sumitomo Mikuni Chemical] (CI
42045), crystal violet (CI
A2555), brilliant green (CI 4
204G), ethyl violet, methyl violet (CI 42535), methyl green (CI
45285), erythrosin B (Cl 4543)
0), Pesic Tsuksin (CI 4251G),
Malachite green (CI 42000), oil red <C160505), m-cresol purple, rhodamine B (CI 45170), auramine (CI 41000), 4-1)-diethylaminophenylimino naphthoquinone, cyano-p-diethylaminophenyl acetanilide, etc. Typical examples include triphenylmethane-based, diphenylmethane-based, oxazine-based, oxatene-based, iminonaphthoquinone-based, azomethine-based, and anthraquinone-based dyes.

Such specific dyes are based on the total solid content of the photosensitive composition.
Preferably 0.01 to 5% by weight, more preferably 0.1
Contained at ~3% by weight.

The photosensitive lithographic printing plate of the present invention can be obtained by dissolving the photosensitive composition described above in a suitable solvent and coating the solution on a support. Examples of solvents used include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acedate, ethylene glycol monomethyl ether, ethylene glycol monobutyl needle, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and pyrene glycol. , propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate, and propylene glycol monobutyl ether. In addition, dioxane, Ethers such as tetrahydrofuran and tetrahydrobilane; Ketones such as methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, methyl amyl ketone, diethyl ketone, diacetone alcohol, cyclopentanone, and cyclohexanone: methanol, ethanol, propatool, isopropylene Alcohols such as Patul, n-butanol, 5ec-butanol, tert-butanol, n-pentanol, isobentanol, n-hexanol, isohexanol; ethyl acetate, propyl acetate, butyl acetate, amyl acetate, hexyl acetate, Esters such as ethyl propionate and butyl propionate can also be used.

Examples of the support used in the photosensitive lithographic printing plate of the present invention include aluminum plates, metal plates such as zinc, copper, and iron, paper on which metals are vapor-deposited, and plastic films, but aluminum plates are most preferred. . Particularly preferred is an aluminum plate that has been subjected to surface treatments such as graining, anodizing, and, if necessary, sealing. Further, the coating m of the photosensitive composition on the support varies depending on the use, but - 0.5 to 3.5 as solid content in the film.
A range of g/f is appropriate.

From the photosensitive lithographic printing plate obtained as described above, a positive image can be obtained by developing with a positive developer after image exposure. Further, a negative image can be obtained by subjecting the entire surface to a heat treatment after image exposure, further exposing the entire surface of the photosensitive layer to light, and then developing with an aqueous alkaline developer.

Image exposure of the photosensitive lithographic printing plate in the present invention includes, for example,
The image-formed translucent film is used as an original in close contact with a photosensitive lithographic printing plate, and then exposed to a fluorescent tube, xenon lamp,
This can be carried out by various commonly used methods, such as using a publicly available light source such as a high-pressure mercury lamp charged with a metal halide or a carbon arc lamp.

Further, in the present invention, it is preferable that the heat treatment following the above image 1gIn light is carried out at a temperature in the range of 80 to 200°C, preferably 90 to 160°C, for 1 to 30 minutes, preferably 3 to 15 minutes, If the heating temperature is too low, problems such as the photosensitive layer dissolving in the developer during development may occur.
Furthermore, if the heating temperature is too high, problems such as the entire surface of the photosensitive layer being cured may occur.

Such heat treatment is generally carried out by leaving the photosensitive lithographic printing plate in heated air for the above-mentioned period of time after image exposure; It is also possible to do so.

Prelude to the above]! l! The subsequent full-surface exposure can be performed using the same apparatus as the image exposure.

Further, as the aqueous alkaline developer used for developing the photosensitive lithographic printing plate in the method of the present invention, the following developer can be mentioned.

That is, the developer according to the present invention is an alkaline aqueous solution, and the alkaline agents used are preferably potassium silicate, lithium silicate, sodium silicate, sodium hydroxide, potassium hydroxide, lithium hydroxide, and tertiary phosphorus. Examples include sodium acid, sodium diphosphate, potassium triphosphate, potassium diphosphate, sodium carbonate, potassium carbonate, and the like. Among these, a developer containing an alkali silicate such as potassium silicate, lithium silicate, or sodium silicate is preferable because it has good development gradation, and the composition of the alkali silicate is [8i 02 ] in molar ratio.
/ [M] -0,5~1.5 (cl::Ic[
8102], [M] LtSotlPtLS i 02
(D) Shows the molar concentration of bilIlf and total alkali metals. ), and a developer containing 0.8 to 8 weight percent of 5iQ2 is preferably used. Behind this alkali silicate composition, especially in molar ratio [Si 02 ]/[M]
=0.5~0.751' ant, and 5102 is 0.8~
A developer with a concentration of 4% by weight is preferably used because it is easy to neutralize developer waste due to its low concentration, while a developer with a concentration of 4% by weight exceeds 0.75 and is 1.3% by weight.
A developer containing 1 to 8% by weight of Ka5i02 is preferably used because it has a high buffering power and a high throughput.

In addition, it is preferable that the alkali silicate contains 20 mol% or more of potassium as the alkali metal in all the alkali metals, since the generation of insoluble matter in the developer is small, and more preferably 90 mol% or more of potassium. The most preferred case is ioo mole % of potassium.

The I)H value of the developer according to the present invention is 12 at 25°C.
or more, preferably 12.5 to 14.0.

Furthermore, water-soluble sulfites such as sodium 1illI acid, potassium sulfite, lithium sulfite, and magnesium sulfite can be added to the developer.

The preferred content of sulfite in the developer is 0.05
-4% by weight, more preferably 0.1-1% by weight.

Further, in the developer, anionic surfactants and amphoteric surfactants such as those described in JP-A-50-51324 and JP-A-59-75255 and JP-A-Sho 60-
By containing at least one kind of nonionic surfactants such as those described in JP-A No. 111246 and JP-A No. 60-213943, or by
By containing a polymer electrolyte as described in JP 5-95946 and JP 56-142528,
It is preferable because it can improve the wettability to the photosensitive composition and further improve the raw A property. Although there is no particular restriction on the amount of surfactant added, a concentration of 0.003 to 3% by weight is preferable, and a concentration of 0.006 to 1% by weight is particularly preferable.

Furthermore, the developer used in the present invention can contain an antifoaming agent. Suitable antifoaming agents include organosilane compounds.

Various conventionally known methods can be used to develop the photosensitive lithographic printing plate of the present invention which has been imagewise exposed with the developer described above. Specifically, for example, a method in which the image-exposed photosensitive lithographic printing plate is immersed in a developer, a method in which a developer is ejected from a number of nozzles onto the photosensitive layer of the photosensitive lithographic printing plate, and a developer. Examples include a method of wiping the photosensitive layer of the photosensitive lithographic printing plate with a sponge moistened with a sponge, and a method of applying a developer to the surface of the photosensitive layer of the photosensitive lithographic printing plate with a roller. Further, after applying the developer to the photosensitive layer of the photosensitive lithographic printing plate in this manner, the surface of the photosensitive layer may be lightly rubbed with a brush or the like. The developing conditions can be appropriately selected depending on the developing method. - For example, in a developing method by immersion, a method in which the material is immersed in a developer at a temperature of about 10 to 40° C. for about 10 to 80 seconds is selected.

[Examples] The present invention will be explained below using Examples, but the present invention is not limited thereto.

Example 1 A photosensitive solution having the following composition was prepared and coated on a grained aluminum plate using a roll coater to reduce the solid content to 1.
A photosensitive lithographic printing plate sample 1 was obtained by coating to a coating weight of 8 Q/f and drying.

(Photosensitive liquid composition) ・Trihydroxybenzophenone and naphthoquinone (1
, 2) Ester compound with -diazide-4-sulfonic acid chloride 2.3 parts by weight Phenol, m-2D
- Copolycondensation resin of mixed cresol and formaldehyde (the molar ratio of phenol, ■-cresol and p-cresol is 48:32:20)
6.7 parts by weight・Novolac resin synthesized from paraoctylphenol and formalin 0.9 parts by weight・2
-Trichloromethyl-5-(β-benzofuryl vinyl)
- 0.05 parts by weight of 1,3,4-oxadiazole, 8 parts by weight of ethylene glycol monomethyl ether, ψ 37 parts by weight of ethylene glycol monoethyl ether, 0,731 m parts of orange IO. Photosensitive lithographic printing plates 2 to 7 were prepared in the same manner except that the compounds shown in 1 were used.

Each of the samples 1 to 7 obtained above was cut into two pieces, and one of them was exposed to a positive type original image, and then 4% sodium metasilicate was prepared.
A clear positive image was obtained by immersion in a wired solvent-free developer solution containing 0.1% sodium benzenesulfonate at a temperature of 27°C for 20 seconds (under JX). (The image obtained by this process is referred to as a positive image.) Exposure was carried out at 2KW using a step tablet for sensitivity measurement (No. Light using a metal halide lamp (Idolfin 2000 manufactured by Iwasaki Electric) as a light source 8. The test was performed at OmW/Ct' for 70 seconds.

For the other sample, a negative original was exposed under the same conditions as above, left in an air constant temperature bath kept at 140°C for 5 minutes, and then the entire surface was exposed under the same conditions as the above image exposure without using the original. did. After that, when it was immersed for 20 seconds in a positive developing solution (a developer prepared by diluting SDR-1 manufactured by Konica (■) six times with water) at a temperature of 27°C, a clear negative image was obtained (hereinafter referred to as The image obtained in this way is called a negative-positive image.) The image formation state of the step tablet image formed on this negative-positive image and the evaluation of the exposed visible image are shown in Table 1. After heat treatment The visible image was clear in both cases after full-surface exposure.

Comparative Example 1 Photosensitive lithographic printing plate sample 8 was prepared in the same manner as sample 1 using a photosensitive liquid having the same composition as in example 1 except that Orangeye was removed. Comparative Example 1 was carried out in the following manner.

When a C positive image and a negative image were formed on the obtained sample, the positive image was stably formed, but the negative image was not stably formed.

Comparative Example 2 Photosensitive lithographic printing plate sample 9 was prepared using a photosensitive liquid having the same composition as in Example 1 except that Orange ■ was replaced with Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.). Comparative Example 2 was conducted in the same manner as above. When both positive and negative images were formed on the obtained sample, a negative image was formed which was as stable as a positive image. Table 1 shows the results of evaluating visibility.

Comparative Example 3 In Example 1, instead of the ester compound of trihydroxybenzophenone and naphthoquinone-(1,2)-diazide-4-sulfonic acid chloride, pyrogallol acetone resin and 1,2-naphthoquinonediazide-5-sulfonic acid were used. After preparing photosensitive lithographic printing plate sample 10 using a photosensitive solution having exactly the same composition except that Jetanolamine was used in place of Orange I, a photosensitive lithographic printing plate sample 10 was prepared in the same manner as in Example 1. Comparative Example 3 was conducted.

The results are shown in Table-1.

As is clear from Table 1, samples N0.1 to 7 of the present invention using acidic dyes are all different from sample N0.1 containing no dye.
Sample No. 19 provides a more stable negative-positive image than Sample No. 008 and further contains an organic dye other than the acid dye of the present invention.
It has excellent exposure visible image performance and sensitivity compared to .

[Advantageous Effects of the Invention 1] According to the present invention, a photosensitive lithographic printing plate for both positive and negative types is provided which can obtain improved visible image quality and sensitivity through negative processing.

Patent applicant: Konica Corporation (and 1 other person) representative: Patent attorney: Miyao Ichinose

Claims (2)

[Claims] (1) A positive type/negative film characterized by having on a support a photosensitive layer formed from a photosensitive composition containing an orthoquinone diazide compound and an alkali-soluble resin, and containing at least one acidic dye. Photosensitive lithographic printing plate that can be used as a mold. (2) After image exposure of a photosensitive lithographic printing plate having a photosensitive layer formed on a support from a photosensitive composition containing an orthoquinone diazide compound and an alkali-soluble resin and containing at least one acidic dye. . A method for preparing a lithographic printing plate, which comprises performing heat treatment, then exposing the entire surface of the photosensitive layer to light, and then developing with an aqueous alkaline developer.