JPH0364059B2 - - Google Patents

Description

[Detailed description of the invention]

(a) Industrial application field The present invention relates to a photosensitive lithographic printing plate (hereinafter referred to as "PS plate") which is formed by coating a photosensitive composition on the surface of a support such as aluminum foil, paper, or plastic film. It relates to developers, and in particular PS plates whose photosensitive composition is mainly composed of diazo compounds (hereinafter referred to as "negative type PS plates") and PS plates whose photosensitive composition is mainly composed of quinonediazide compounds (hereinafter referred to as "positive type PS plates"). Both types of
This invention relates to a developer that can be suitably used for PS plates. (b) Prior Art A PS plate is used for lithographic printing by exposing it to light to create lipophilic ink-attached areas that form image areas and hydrophilic areas that form non-image areas. There are two types of PS versions: one is a negative type PS version, and the other is a positive type PS version. In the former, a photo-insoluble diazo compound is coated on a support, and the hardened diazo compound remains in the exposed areas and becomes a lipophilic ink attachment area, and the non-exposed areas are removed to become hydrophilic areas. It is something.
On the other hand, in the latter case, a photo-soluble quinonediazide compound is coated on a support, and the decomposed quinonediazide compound in the exposed area is removed and becomes a hydrophilic part, and the quinonediazide compound in the non-exposed area becomes a lipophilic ink. This is the attachment part. In either type, the diazo compound or decomposed quinonediazide compound must be removed, and this is generally accomplished by dissolving it in an aqueous alkaline solution. Since aqueous alkaline solutions alone have poor developing effects, anionic or amphoteric surfactants and alcohols are appropriately blended and used depending on each type. (c) Problems to be solved by the invention However, this requires the use of different developers for the negative type PS plate and the positive type PS plate.
Using two different types of developing solutions is complicated in performing the developing work, and is uneconomical as it requires two developing machines to increase work efficiency. Therefore, in order to solve this drawback, the present inventors have already filed a patent application for a developer that can successfully develop both types of PS plates (Japanese Patent Application No. 1983-
(Refer to No. 240754/Japanese Unexamined Patent Publication No. 130741/1983). The present invention relates to an improvement on the invention of Japanese Patent Application No. 58-240754, and further improves the developing ability. (d) Means and effects for solving the problems That is, the present invention provides (a) ethylene glycol monophenyl ether or ethylene glycol monobenzyl ether, (b) an anionic surfactant, and (c) an alkali metal. A photosensitive lithographic plate comprising a hydroxide, (d) a silicate, (e) a reducing agent, (f) a tetrafluoroborate, and (g) ethylenediaminetetraacetic acid or a salt thereof. This relates to a developer for printing plates. In the present invention, ethylene glycol monophenyl ether or ethylene glycol monobenzyl ether is used as the first component. These are used alone or in combination, and are mainly used to dissolve diazo compounds or decomposed quinonediazide compounds. Examples of the anionic surfactant, which is the second component used in the present invention, include fatty acid salts, alkylbenzene sulfonates, alkyl sulfonates, alkylnaphthalene sulfonates, α-olefin sulfonates, dialkyl sulfosuccinates, α −
Sulfonated fatty acid salt, N-methyl-N-oleyl taurine, alkyl sulfate, polyoxyethylene alkyl ether sulfate, alkyl phosphate, polyoxyethylene alkyl ether phosphate, polyoxyethylene alkyl phenyl ether sulfate, Polyoxyethylene alkyl phenyl ether phosphates, naphthalene sulfonate formaldehyde condensates, naphthalene sulfonates, etc. can be used, but among these, alkylbenzene sulfonates, alkylnaphthalene sulfonates, polyoxyethylene alkyl phenyl ethers A sulfate, particularly an alkylnaphthalene sulfonate, is suitable in combination with an ether compound as the first component, since a small amount can produce a developing effect. Anionic surfactants function to improve the solubility of the ether compound, which is the first component, in water, and to improve the permeability of the ether compound and other components into the photosensitive composition. . The third component of the alkali metal hydroxide used in the present invention includes sodium hydroxide,
Lithium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, and francium hydroxide can be used. This dissolves in water to become an alkaline aqueous solution, which functions to dissolve diazo compounds and decomposed quinonediazide compounds. In particular, alkali metal hydroxides dissolve both diazo compounds and quinonediazide compounds well, and are important components in the present invention. If a substance other than the alkali metal hydroxide, such as soda carbonate, is used, it has the ability to dissolve the diazo compound but has a poor ability to dissolve the quinonediazide compound, and cannot be used in the present invention. As the silicate used as the fourth component in the present invention, potassium silicate, calcium silicate, sodium silicate, lithium silicate, magnesium silicate, etc. can be used. This is intended to prevent corrosion of the PS plate support, which is made of aluminum, and to provide a versatile developer. That is, the alkali metal hydroxide is strongly alkaline and has a corrosive effect on the aluminum support, and the silicate acts to alleviate this effect. As the reducing agent used as the fifth component in the present invention, hydrogen iodide, hydrogen sulfide, sulfite, lithium aluminum hydride, sodium sulfide, ammonium sulfide, ferric salts, stannic salts, etc. can be used. This serves to prevent oxidation of the aluminum surface in the developer when the PS plate support is aluminum. Examples of the tetrafluoroborates used as the sixth component in the present invention include ammonium tetrafluoroborate, sodium tetrafluoroborate,
Potassium tetrafluoroborate and the like can be used. This is true when the PS plate support is aluminum.
It acts on the aluminum surface and creates a clean surface. In the present invention, ethylenediaminetetraacetic acid or a salt thereof is used as the seventh component. This has the effect of capturing (chelating) calcium and magnesium contained in the water in the developer and softening hard water. The blending ratio of each component in the developer according to the present invention is 100 parts (by weight, the same applies hereinafter) of the ether compound as the first component, 500 to 1,500 parts of the anionic surfactant, and 500 to 1,500 parts of the alkali metal hydroxide. 50 things
~200 parts, 50-400 parts of silicate, 50-150 parts of reducing agent
1 to 6 parts of tetrafluoroborate and 0.5 to 3 parts of ethylenediaminetetraacetic acid or its salt. Among these, the more preferred blending ratio of the anionic surfactant is around 1000 parts, and the more preferred blending ratio of the alkali metal hydroxide is around 100 parts. The ratio of anionic surfactants, alkali metal hydroxides, silicates, etc. to the ether compound, which is the first component, is not critical, but if the anionic surfactant is less than 500 parts, The main effects of anionic surfactants, namely the effect of improving the solubility of ether compounds in water and the effect of improving the permeability of ether compounds and alkali metal hydroxides into photosensitive compositions, are insufficient. On the other hand, if the amount exceeds 1500 parts, there is less tendency to have a positive effect on the development effect. The alkali metal hydroxide exerts a direct action to dissolve the photosensitive composition together with the ether compound, which is the first component, and when it is less than 50 parts, it has no ability to dissolve diazo compounds and decomposed quinone diazide compounds. If the amount is less than 200 parts, the development speed tends to be slow, and if the amount is more than 200 parts, there is a tendency to corrode the support such as aluminum, and there is also a risk of damaging the image area. If the amount of silicate is less than 50 parts, the effect of alleviating the strong alkalinity of alkali metal hydroxide will be reduced,
If the amount exceeds 400 parts, the alkali metal hydroxide tends to inhibit its ability to dissolve diazo compounds and the like. If the reducing agent is less than 50 parts, the effect of preventing oxidation on the aluminum surface, which is the support, will be poor;
If the amount is more than 30%, the aluminum surface will be reduced and the hydrophilic function of the aluminum surface that has been anodized in advance will be impaired. If the amount of tetrafluoroborate is less than 1 part, the cleaning effect on the aluminum surface of the support is poor, and if it is more than 6 parts, the aluminum surface tends to be corroded too much. If the amount of ethylenediaminetetraacetic acid or its salt is less than 0.5 part, the water softening effect of the developer will be poor;
If the amount is more than 3 parts, it tends to act on other components, such as aluminum metal hydroxides and silicates, and have an adverse effect. In the present invention, the above seven components are essential, but preservatives, alcohols such as benzyl alcohol and cyclohexanone, and ketones may also be mixed. When using the developer according to the present invention, it is prepared as an aqueous solution in the same manner as in the conventional case.
The adjustment should be such that the amount of the first component, the ether compound, is 0.2 to 5 parts per 100 parts of water. (E) Example (i) Composition of developer A developer was prepared with the following blending ratio. Example 1 Ethylene glycol monophenyl ether 10g Sodium alkylnaphthalene sulfonate 60g Sodium hydroxide 5g Sodium silicate (water glass; No. 3, solid content 50
%) 5g Sodium sulfite 5g Potassium tetrafluoroborate 0.2g Ethylenediaminetetraacetic acid 0.1g Water 1000g Example 2 Ethylene glycol monophenyl ether 10g Sodium alkylnaphthalene sulfonate 50g Sodium hydroxide 10g Potassium silicate 3g Lithium aluminum hydride 0.3g Tetrafluoroboric acid Sodium 1.0g Sodium ethylenediaminetetraacetate 0.3g Water 500g Example 3 Ethylene glycol monobenzyl ether 10g α-sulfonated fatty acid sodium 70g Sodium hydroxide 20g Sodium silicate (water glass; No. 3, solid content 50
%) 5g Sodium sulfite 7g Potassium tetrafluoroborate 0.4g Ethylenediaminetetraacetic acid 0.1g Water 300g Comparative example 1 Ethylene glycol monophenyl ether 10g Sodium alkylnaphthalene sulfonate 60g Sodium hydroxide 5g Sodium silicate (water glass; No. 3, solid content 50
%) 5g Sodium tetraborate 0.5g Water 919.5g Next, positive and negative image films were superimposed on commercially available positive type PS plates (Ulstar PS) and negative type PS plates (Ulstar NS) manufactured by Nippon Seifaku Co., Ltd., respectively. The sample was exposed for 40 seconds from a distance of 1 m using a 4KW ultra-high pressure mercury lamp. The exposed PS plate was immersed in each of the above-mentioned developers for 20 seconds at room temperature (20°C) and then washed with water to obtain a lithographic printing plate. (ii) Number of printed sheets This printing plate was printed on high-quality paper using a Heidel KORD printing machine. We were able to print more than 50,000 copies of the lithographic printing plate without any problems. (iii) Development processing capacity In addition, each PS plate after the above exposure was developed at 20°C for 60 seconds using an automatic processor 600E (manufactured by Fuji Photo Film Co., Ltd.), and the processing capacity at that time was determined. Examined. As a result, for both positive type and negative type PS plates, the developer solution of Examples 1 to 3 had an area of 25 m ² /or more, whereas the developer solution of Comparative Example 1 had an area of 15 m ² /. (iv) Development speed The development speed was measured at room temperature (20°C) using the following commercially available PS plates and the following commercially available developers, the developers of Examples 1 to 3, and the developer of Comparative Example 1. .

[Table] The results are shown in Tables 1 and 2, and the developer solutions of Examples 1 to 3 according to the present invention were

[Table] (Note) Development speed is expressed in seconds.

[Table] (Note) Development speed is expressed in seconds.
It can be applied to all commercially available negative type and positive type PS plates, and its development speed is comparable to conventional products. The development speeds in Tables 1 and 2 are as follows: Pour 100 ml of developer into a stainless steel vat with bottom dimensions of 15 x 18 cm, insert a PS plate with dimensions of 10 x 10 cm, and immerse it every 10 seconds. The plate was taken out, washed with water, and the surface of the plate was wiped with protect ink, and the immersion time was indicated by the time when no stain was observed. (v) Developing solution life Pour 100 ml each of the commercially available developing solution used above, the developing solution of Examples 1 to 3, and the developing solution of Comparative Example 1 into the vat used in the development speed measurement, and then
It was left at ℃ for 18 hours. Next, water in an amount reduced by the above-mentioned standing was added to the residual developer in each vat to make 100 ml, and the developing speed was measured in the same manner as above using these developers. The results are shown in Tables 3 and 4. In the case of the developers of Examples 1 to 3 according to the present invention, there was hardly any decrease in the developing effect due to leaving the developer. It was confirmed that it has a long lifespan.

【table】

[Table] (Note) Development speed is expressed in seconds.

[Table] (Note) Development speed is expressed in seconds.
(F) Effects of the Invention As is clear from the above description, the developer according to the present invention can develop well both commercially available negative type and positive type PS plates, and furthermore, Even compared to developer,
It also exhibits excellent effects in terms of the number of plate prints, development speed, and developer life. Also, special request in 1982
Even when compared to the invention of No.-240754, it is about 1.5 to 2 times better in development processing ability. Furthermore, when aluminum is used as a support for the PS plate, the reducing agent, tetrafluoroborate, and ethylenediaminetetraacetic acid or its salt exert the above-mentioned effect on the aluminum surface against the water in the developer, and the aluminum surface It has the effect of improving the hydrophilicity of the lithographic plate, and therefore it also has the effect of making it possible to print beautiful printed matter from the obtained lithographic plate.

Claims (1)

[Claims] 1. (a) ethylene glycol monophenyl ether or ethylene glycol monobenzyl ether, (b) anionic surfactant, (c) alkali metal hydroxide, and (d) silicate. , (e) a reducing agent, (f) a tetrafluoroborate, and (g) ethylenediaminetetraacetic acid or a salt thereof. 2. The developer for photosensitive lithographic printing plates according to claim 1, wherein the anionic surfactant is an alkylnaphthalene sulfonate.