JPS61215554A - Developing solution for photosensitive lithographic plate - Google Patents

Abstract

PURPOSE:To obtain a developing soln. superior in each of developing power, developing stability, processing capacity, foaming inhibition property, etc., and suitable for developing a photosensitive lithographic plate contg. an o- quinonediazide compd. as a photosensitive component by incorporating specified amount of polyethylene glycol having weight average mol.wt. of >=300 with an aq. soln. of alkali silicate. CONSTITUTION:The developing soln. contains alkali silicate, such as alkali metal silicate or ammonium silicate, and polyethylene glycol having weight average mol.wt. of >=300 in an amt. of 0.0001-0.1wt% of the developing soln., and it is used for developing a PS plate. This plate is obtained by forming a photosensitive layer contg. an o-quinonediazide compd. on a support, preferably, made of pure aluminum or its alloy, and having a hydrophilic surface. When the PS plate is exposed to actinic rays, such as a carbon arc lamp, rich in such rays through a transparent original, the exposed parts are changed into an alkali-soluble type, and the exposed parts of the photosensitive layer is dissolved off by processing it with the developing soln. to disclose the hydrophilic surface of the support, thus permitting the lithographic plate to be obtained.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an improved developer for a photosensitive lithographic printing plate (hereinafter abbreviated as 28 plate) containing an 0-quinonediazide compound as a photosensitive component. be.

[Conventional technology]

It is known that the diazo group of an 0-quinonediazide compound is decomposed by irradiation with actinic rays, resulting in a compound having a carboxyl group. Therefore, when a photosensitive layer containing an 0-quinonediazide compound is treated with an alkaline developer after image exposure, the exposed area is removed and the unexposed area becomes an image. It is extremely important as a photoresist composition for photosensitive layers or coatings. In particular, a composition in which an alkali-soluble resin is mixed with an 〇-quinonediazide compound is advantageously used from the viewpoint of economy and practicality.

As the developing solution for these O-quinonediazide photosensitive layers, aqueous solutions of sodium triphosphate, sodium hydroxide, sodium silicate, potassium silicate, ammonium silicate, etc., alone or in combination, are used. However, aqueous solutions of sodium hydroxide and sodium triphosphate have a strong etching effect on metals such as aluminum, and are therefore inconvenient as developing solutions for 28 plates using such metal supports.

In addition, the development results are extremely variable, and furthermore, the developing ability is significantly reduced by repeated use, and the amount (processing ability) of the 28 plate that can be processed with a fixed volume of developer is very small.

Therefore, in recent years, an aqueous solution of aluminum silicate or an aqueous solution of potassium silicate has been used because it is relatively advantageous in dealing with such problems. It has a weak etching effect on metals, and at the same time, silicon oxide (SiOt) and sodium oxide (N
atO) or potassium oxide A (K, O) content ratio (general Ni S t O2 / Nat O or S > Ot /
This is because the development performance can be adjusted to some extent by adjusting the KtO molar ratio) and concentration. However, when trying to increase the developing power, development stability (the allowable development time range in which image quality is maintained at the optimum development time), a developer with poor development stability becomes more likely to cause image loss as the development time becomes longer. ), and when attempts were made to improve development stability, there was a tendency for development power and processing ability to be lacking.

In other words, the problem with this developer is that if the alkaline strength is increased, it will have excellent developing power and processing ability, but it lacks development stability, and in order to obtain sufficiently good development stability, the alkali concentration must be lowered. Therefore, it lacked processing power. Therefore, if development stability can be obtained in a state of high alkaline strength, a developer excellent in both developing power and processing ability can be obtained.

JP-A-50-51324 discloses a method of adding an anionic surfactant or an amphoteric surfactant to the developing solution as a method of obtaining development stability in a state of high alkaline strength, and a method of adding a water-soluble cationic acid or a chlorimer. is published in Japanese Unexamined Patent Application Publication No. 55-9
5946, and JP-A-56-142528 describes a method of adding a water-soluble amphoteric polymer electrolyte P. However, all of these developing solutions have the disadvantage that they foam during development when developed using an automatic processor.

[Purpose of the invention]

Therefore, an object of the present invention is to provide a developer suitable for a photosensitive lithographic printing plate containing an 0-quinonediazide compound as a photosensitive component, which is excellent in developing power, development stability, processing ability, foaming property, etc. be.

[Structure of the invention]

Polyethylene glyfur of 0.0001 to 0.1
It has been found that the above object can be achieved by containing the above amount by weight%.

The alkali silicate used in the present invention is preferably one that exhibits alkalinity when dissolved in water, such as alkali metal silicates such as sodium silicate, potassium silicate, lithium silicate, ammonium silicate, etc. These may be used alone or Two or more types can be used in combination.

In a preferred embodiment of the present invention, the alkali silicate is an alkali metal silicate or ammonium silicate, and the S
i O2/M! O molar ratio (M represents an alkali metal atom or an ammonium group) is 0.5 to 3.0, particularly preferably 1.0 to 2.0, the concentration of alkali silicate is 1 to 15% by weight, Particularly preferably 1.5 to 10% by weight
An example of this is an embodiment.

The range is from 400 to 6000, and the particularly preferred range is 5.
00-1500. The content of polyethylene glycol contained in the developer is 0.0001 to 0.1% by weight
and the preferable content is 0.001 to 0.05% by weight
When the content is less than o, oooi weight %, the effect of improving development stability is poor, and when the content exceeds 0.1 weight %, the developing ability is significantly reduced.

The following additives can be added to the developer of the present invention in order to further improve the developing performance. For example, JP-A-5
NaCl described in Publication No. 8-75152.

Neutral salts such as KCI and KBr, JP-A-58-1909
Chelating agents such as EDTA and NTA described in No. 52, (Co (N
Hs) a) CJs, C.

Complexes such as C1t.6H,0, sodium alkylnaphthalenesulfonate described in JP-A-50-51324, N-
Anionic or amphoteric surfactants such as tetradecyl-N, N-dihydroxyethylbetaine, U.S. Pat. No. 4,37
Nonionic surfactants such as tetramethyldecynediol described in No. 4.920, JP-A-55-95946
Cationic polymers such as methyl chloride quaternized product of p-dimethylaminomethyl polystyrene described in the publication No.
Ampholytic polymer electrolyte such as a copolymer of vinylbenzyltrimethylammonium chloride and sodium acrylate described in JP-A-56-142528, JP-A-57-19
Reducing inorganic salts such as sodium sulfite described in Publication No. 2951,
Inorganic lithium compounds such as lithium chloride described in JP-A-58-59444, organometallic surfactants containing 81% Ti and the like as described in JP-A-59-75255, and organometallic surfactants as described in JP-A-59-84241. Organic boron compound, iodine
Examples include quaternary ammonium salts such as tetraalkylammonium oxides described in Patent No. 7 Patent No. 101.010.

On the other hand, the PS plate to which the developer of the present invention is applied has a photosensitive layer containing an O-quinonediazide compound on a support having a hydrophilic surface.

Preferred examples of the support include pure aluminum plates and aluminum alloy plates, as well as plastic films laminated or vapor-deposited with aluminum. The surface of the aluminum plate is preferably subjected to a surface treatment such as graining treatment, immersion treatment in an aqueous solution of sodium silicate, potassium fluorozirconate, phosphate, or the like, or anodization treatment. Also, U.S. Patent No. 2.714
．． As described in the specification of No. 066, an aluminum plate was grained and then immersed in an aqueous sodium silicate solution, and an aluminum plate was anodized as described in Japanese Patent Publication No. 1983-5125. Those which are later immersed in an aqueous solution of an alkali metal silicate are also preferably used. The above-mentioned anodizing treatment may be carried out by electrolysis using an aqueous or non-aqueous solution of an inorganic acid such as phosphoric acid, chromic acid, nitric acid, or boric acid, or an organic acid such as oxalic acid or sulfamic acid, or a salt thereof alone or in combination of two or more. This is carried out by passing an electric current through a liquid using an aluminum plate as an anode.

Also effective is silicate electrodeposition as described in US Pat. No. 3,658,662.
□Furthermore, a support coated with relaxed grains as disclosed in U.S. Pat. Anodized products are also useful.

Further, chemical processing is performed after graining as described in U.S. Pat. No. 3,834,998.

Aluminum plates that have been anodized and then anodized are also preferred. These hydrophilic treatments are performed not only to make the surface of the support hydrophilic, but also to prevent harmful reactions with the photosensitive composition provided thereon, and to improve the adhesion with the photosensitive layer. It is applied for various purposes, such as to improve the quality of life.

The photosensitive layer provided on the hydrophilic surface of the support contains an O-quinonediazide compound. Particularly preferred 0-quinonediazide compounds are 0-naphthoquinonediazide compounds, such as those described in U.S. Pat. No. 3.046.110;
Same No. 3.046.111, Same No. 3.046, 121, Same No. 3.046.115, Same No. 3.046.118
No. 3.046.119, No. 3.046.12
No. 0, No. 3, No. 046.122, No. 3.046.1
No. 23, No. 3.061゜430, No. 3.102.
No. 809, No. 3.106.465, No. 3.635
．． It is also described in specifications such as No. 707 and No. 3.647.443.

Among these compounds, O-naphthoquinonediazide sulfonic acid ester or O-naphthoquinonediazidecarboxylic acid ester of an aromatic hydroxy compound, and O-naphthoquinonediazide sulfonamide or O-naphthoquinonediazidecarboxylic acid amide of an aromatic amino compound are preferred. In particular, the ester of 1,2-diazobenzoquinonesulfonic acid chloride and bolyhydroxyphenyl described in JP-A No. 56-1044, or the 1,
Esters of 2-diazonaphthoquinonesulfonic acid chloride and resorcinol-benzaldehyde resin are preferred.

Although these photosensitive components, which are O-quinonediazide compounds, can form a photosensitive layer by themselves, it is preferable to mix a resin or the like into the carrier of the photosensitive layer for the purpose of improving the physical properties of the photosensitive layer.

Examples of the above resins include phenol formaldehyde resin, cresol formaldehyde resin, p-te
Alkali-soluble resins such as rt-butylphenol resin and phenol-modified xylene resin are preferably used. The alkali-soluble resin is preferably contained in the photosensitive layer in an amount of 40 to 80% by weight.

The photosensitive layer may further contain additives such as dyes, plasticizers, components for imparting printout performance, and the like.

The photosensitive layer is applied onto the support using a suitable solvent solution. The coating amount of the photosensitive layer is preferably 0.1 to 7,j
ii/tFl'', more preferably 0.5-39/r
It is rl.

When such a PS plate is exposed through a transparent original to a light beam rich in actinic rays such as a carbon arc burner, a mercury lamp, a metal halide lamp, a xenon lamp, a tungsten lamp, etc., that part becomes alkali-soluble. Therefore, when treated with the developer of the present invention, the photosensitive portion of the photosensitive layer is eluted, the hydrophilic surface of the support is exposed, and a lithographic printing plate is obtained.

The preferred temperature at which the development process is carried out is 10°C to 35'C, and the more preferred range is 5°C to 35'C.

〔Effect of the invention〕

By using the developer of the present invention, development stability is increased and development conditions can be extremely easily managed.

In addition, processing capacity is increased, and more PS plates can be developed with a smaller amount of developer.

Therefore, the developer of the present invention has significant advantages when used as a developer and replenisher when developing large quantities of PS plates, compensating for developer fatigue by adding a replenisher.

〔Example〕

Hereinafter, the present invention will be explained in more detail using examples. Note that "%" indicates heavy Ik% unless otherwise specified.

Example 1 An aluminum plate with a thickness of 0.3fi was electrochemically roughened in a nitric acid solution, thoroughly washed, and then anodized in a sulfuric acid solution to remove a 2.51//g oxide film from the aluminum plate. formed on the plate surface.

After washing with water and drying, esterified product 3 of resorcin benzaldehyde resin and naphthoquinone 1,2-diazido-5-sulfonyl chloride synthesized according to the example of JP-A-56-1044! Is and 9 parts of cresol formalin novolac resin and Victoria Pure Blue B
A photosensitive solution prepared by dissolving 0.12 parts of OH (manufactured by Hodoya Kagaku Kogyo Co., Ltd.) in 100 parts of 2-methoxyethanol was coated on the above support using a rotary coater and dried to give a coating of 2.811/
A photosensitive lithographic printing plate having a black photosensitive layer was obtained.

This PS plate was exposed using a 2 kW metal halide lamp through a step wedge with a density difference of 0.15. On the other hand, as a developer, SiO with a S10t/NatO molar ratio of 1.7 and silicic acid with a content of 5%) I
A developer was prepared by adding polyethylene glycol to a Jium aqueous solution. Table 1 shows the molecular weight and amount of added polyethylene glyfur.

Two exposed PS plates were immersed in each developer solution maintained at 5°C, one plate was taken out after 1 minute, and the other plate was taken out after 5 minutes and washed with water. As shown in Table 2, the developing solutions of Examples 1 to 3 to which the polyethylene glycol of the present invention was added had extremely high developability compared to aqueous solutions of sodium silicate alone or Comparative Examples 1 to 3. It is found to be stable.

Examples 4, 5 and 6 The same 28 plates as in Example 1 were exposed in the same manner as in Example 1. On the other hand, an image source was prepared by adding polyethylene glycol to an aqueous potassium silica solution having an SjO*/KtO molar ratio of 1.1 and a 5rOt content of 1.3%. Table 3 shows the molecular weight and amount of added polyethylene glyfur. Two exposed 28 plates each at 5℃
After 1 minute, one sheet was immersed in each developer solution maintained at
The other one was taken out after 5 minutes and washed with water. Table 4 shows the step sea urchins eluted from Table 4. Comparative Example 4, an aqueous solution of potassium silicate alone, and Comparative Examples 5 to 7, which used polyethylene glyfur other than the present invention, showed that the polyethylene glyfur of the present invention was added. It can be seen that the developing solutions of Examples 4.5 and 6 have extremely stable developability.

Applicant: Konishiroku Photo Industry Co., Ltd. Procedural amendment June 11, 1986

Claims (1)

[Claims] Development of a photosensitive lithographic printing plate having a photosensitive layer containing an o-quinonediazide compound, characterized in that an aqueous solution containing an alkali silicate contains 0.0001 to 0.1% by weight of polyethylene glycol having a weight average molecular weight of 300 or more. liquid.