JP2579189B2 - Developer composition for photosensitive lithographic printing plate - Google Patents

Description

The present invention relates to an improved developer for a positive photosensitive lithographic printing plate.

(Prior art)

Positive photosensitive lithographic printing plate (hereinafter referred to as positive PS plate)
Is treated with an alkaline developing solution after image exposure, the exposed portions are removed, and the unexposed portions become images. For the positive PS plate, a composition obtained by mixing an alkali-soluble resin with an o-quinonediazide compound is advantageously used in practice, and a mixture obtained by mixing with a novolak resin is generally used. Further, as a developer for the positive PS plate, an alkali agent such as caustic soda, sodium silicate and sodium tertiary phosphate is used. However, since a highly alkaline developer is used,
Alkali activity easily fluctuates. Further, in a method in which replenishment is performed using a replenisher having a higher alkali concentration than that of the mother liquor, the fluctuation of the alkali activity may be further increased. When the fluctuation of the alkali activity is large, the PS
If the alkali activity is too high, small dots and fine lines are lost, and if the alkali activity is too low, the non-image area is stained during printing. Further, even if the alkali activity of the developing solution is the same, the developing property changes due to the fluctuation of the developing time and the developing temperature. Attempts have been made to minimize such variations in developability, and several techniques have been disclosed. JP-A-59-84241 and JP-A-60-1
No. 29750 discloses a technique for adding a specific surfactant. Although these certainly showed good performance with respect to overdevelopability, they were still insufficient, and were developers that easily foamed.

[Object of the invention]

In view of the above problems, an object of the present invention is to provide an improved developer composition for a photosensitive lithographic printing plate having less change in developability.

[Configuration of the invention]

The present inventors have conducted intensive studies to improve these points, and as a result, the above object of the present invention is characterized in that an aqueous solution of alkali silicate contains 0.001 to 10% by weight of polyethylene oxide and polypropylene oxide adducts of glycerin. And a developer composition for a photosensitive lithographic printing plate.

 Hereinafter, the present invention will be described in more detail.

The alkali silicate used in the present invention includes sodium silicate, potassium silicate, lithium silicate, ammonium silicate and the like, and can be used alone or in combination with another alkali agent. Other alkaline agents include sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate tribasic, potassium phosphate tribasic, sodium phosphate dibasic, potassium phosphate dibasic, Examples include ammonium phosphate, mono-, di- or triethanolamine and tetraalkylammonium hydroxide. 0.5 to 20% by weight of alkali silicate
Is preferred.

Various adducts of polyethylene oxide and polypropylene oxide of glycerin used in the present invention are used, but preferably, a form in which polyethylene oxide and polypropylene oxide are block-copolymerized with glycerin as represented by the following formula, The degree of polymerization is an integer of 0 to 300. Further, it is preferable that ethylene oxide is contained in an amount of 30 to 80% by weight in the total molecule.

Various additives can be added to the developer of the present invention. For example, organic solvents, anionic surfactants, cationic surfactants, amphoteric surfactants, sulfites and the like. In particular, when the developer of the present invention is used as a common developer adapted to both a negative PS plate and a positive PS plate, it is advantageous to include the above-mentioned additives.

As the PS plate used in the present invention, an o-quinonediazide compound, an acid-decomposable ether compound, or an ester compound can be given as a typical positive type which changes to alkali-soluble upon exposure. An aromatic diazonium salt or the like is given as a negative type whose solubility decreases upon exposure.

Specific examples of the o-quinonediazide compound include, for example, JP-A-47-5303, JP-A-48-63802, JP-A-48-63803, and
No. 49-38701, No. 56-1044, No. 56-1045, Tokiko Sho 41
No.-11222, No.43-28403, No.45-9610, No.49-1748
No. 1, U.S. Pat.Nos. 2,797,213, 3,046,120, 3,188,2
No. 10, No. 3,454,400, No. 3,544,323, No. 3,573,917
Nos. 3,674,495 and 3,785,825; British Patent 1,227,60
No. 2, 1,251,345, 1,267,005, 1,329,888,
No. 1,330,932 and German Patent No. 854,890.Examples of acid-decomposable compounds are JP-A-60-37549 and JP-A-60-10247.
And the compounds described in JP-A Nos. 60-3625, and these compounds can be preferably applied at least to a photosensitive material using these compounds alone or in combination as a photosensitive component.

These photosensitive components include an aromatic hydroxy compound o-
Quinonediazide carboxylic acid esters and aromatic amino compounds o-quinonediazidesulfonic acid or o-quinonediazidocarboxylic acid amide, and these o-quinonediazide compounds used alone and mixed with an alkali-soluble resin, Is provided as a photosensitive layer.

The alkali-soluble resin includes a novolak type phenol resin, and specifically includes a phenol formaldehyde resin, a cresol formaldehyde resin, a phenol cresol mixed formaldehyde resin, a cresol xylenol mixed formaldehyde resin, and the like. Further, as described in JP-A-50-125806, together with the above-mentioned phenol resin, phenol or cresol substituted with an alkyl group having 3 to 8 carbon atoms, such as t-butylphenol formaldehyde resin, and formaldehyde are used. A condensate of the above is also applicable. The photosensitive layer containing the o-quinonediazide compound as a photosensitive component may further contain, if necessary, additives such as a dye, a plasticizer, and a component for providing printout performance.

The present invention can be applied to a photosensitive layer containing an o-quinonediazide compound as a photosensitive component, preferably in an amount per unit area of about 0.5 to 7 g / m ² .

Representative photosensitive components of the negative photosensitive layer are diazo compounds, for example, diazonium salts and / or diazo resins which are condensates of p-diazophenylamine and formaldehyde, described in JP-B-52-7364. P-
Examples of the phenol salt or fluorocaprate salt of diazophenylamine, such as 3 described in JP-B-49-48001
Diazo resin comprising an organic solvent-soluble salt of a copolycondensate of 4-methoxydiphenylamine-4-diazonium chloride, 4-nitrodiphenylamine and formaldehyde, 2-methoxy-4-hydroxy-condensate of p-diazodiphenylamine and formaldehyde 5-benzoylbenzenesulfonate; tetrafluoroborate, hexafluorophosphate of a condensate of p-diazophenylamine and formaldehyde; and the like. The present invention can be preferably applied at least to a negative photosensitive material containing these as a photosensitive component.

The present invention can be applied not only to the use of these diazo compounds alone but also to the use of a mixture of various resins in order to improve the physical properties of the photosensitive layer. Examples of such a resin include, in addition to shellac and polyvinyl alcohol derivatives, copolymers having an alcoholic hydroxyl group in a side chain described in JP-A-50-118802, and JP-A-55-1553.
No. 55, a copolymer having a phenolic hydroxyl group in a side chain.

These resins include copolymers containing at least 50% by weight of a structural unit represented by the following general formula; (In the formula, R ₁ represents a hydrogen atom or a methyl group, R ₂ represents a hydrogen atom, a methyl group, an ethyl group or a chloromethyl group, and n is an integer of 1 to 10.) and an aromatic hydroxyl group Having from 1 to 80 mol% of monomer units, and from 5 to 90 mol% of acrylate and / or methacrylate ester monomer units;
Polymer compounds having an acid value of 0 are included.

The photosensitive layer of the negative photosensitive material to which the developer composition and the developing method of the present invention are applied may further contain additives such as a dye, a plasticizer, and a component for providing printout performance.

The amount per unit area of the photosensitive layer is at least 0.1 to 7 g /
the present invention can be applied for a range of m ^2.

As the support used in the photosensitive material according to the present invention,
Paper, plastic (eg, polyethylene, polypropylene, polystyrene, etc.) laminated paper, metal plates such as aluminum (including aluminum alloys), zinc, copper, etc., cellulose diacetate, cellulose triacetate, cellulose propionate, polyethylene terephthalate, Examples include plastic films such as polyethylene, polypropylene, polycarbonate, and polyvinyl acetal; paper on which the above-described metal is laminated or vapor-deposited; and chrome-plated steel plate.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to specific examples, but the present invention is not limited thereto.

Example 1 A JIS1050 aluminum plate having a thickness of 0.24 mm was immersed in a 2% aqueous sodium hydroxide solution and subjected to a degreasing treatment.
The surface was electrochemically roughened in a diluted hydrochloric acid solution, washed well, and then anodized in a diluted hydrochloric acid solution to form an oxide film of 2.5 g / m ² on the surface of the aluminum plate.

After the obtained aluminum plate was washed with water and dried, a photosensitive solution having the following composition was applied so as to have a dry weight of 2.5 g / m ² and dried to obtain a positive PS plate. The dimensions of the plate were 1003 × 800 mm.

Photosensitive solution-1 Naphthoquinone-1, a resorcin-benzaldehyde resin
2-diazide (2) -5-sulfonic acid ester (JP-A-5
(Described in Example 1 of Public Relations No. 6-1044) ... 1
Part cresol-phenol-formaldehyde resin ... 3
Part: naphthoquinone-1,2-diazide (2) -5-sulfonic acid ester of tert-butylphenol-benzaldehyde resin (described in Example 1 of JP-A-60-31138) 0.1 part crystal Violet (manufactured by BASF. Dye) ... 0.05
Part Ethylene glycol monomethyl ether 20 parts A transparent positive film and a step tablet were brought into close contact with this positive PS plate, and exposure was performed for 60 seconds from a distance of 70 cm with a 2-kW metal halide lamp.

 Next, developer composition I was prepared as follows.

Developer composition [I]-Potassium silicate A (potassium silicate manufactured by Nippon Chemical Industry Co., Ltd.) 20 parts by weight-Water 1000 parts by weight-Benzoic acid 20 parts by weight-Nikkor defoamer No. 20 (Nikko Chemicals Co., Ltd.) )) 0.8
Parts by weight ・ 20 parts by weight of 50% potassium hydroxide The pH was adjusted to 13.00 at 25 ° C. after the preparation.

Next, the positive PS plate was processed under the following conditions using an automatic developing machine PSQ-910 (manufactured by Konica Corporation).

25 ° C, 20 seconds 27 ° C, 30 seconds 30 ° C, 40 seconds On the other hand, Nikkor defoamer N in the developer composition [I]
Except for o.20, adjusted to PH13.00, developer composition (II)
And The results of development using the positive PS plate and the developer compositions [I] and [II] under the conditions shown in Table 1 are also shown in Table 1. The results in Table 1 are shown by the number of clear stages / the number of solid stages.

As shown in Table 1, the developer [I] of the present invention has a smaller variation in the number of clear stages and the number of solid stages when the developing conditions are used, as compared with the comparative developer [II]. Further, the developing solution of the present invention showed little foaming in the automatic developing machine.

Example 2 An aluminum plate having a thickness of 0.24 mm was immersed in a 20% aqueous sodium phosphate solution to be degreased. This was subjected to electric field polishing at a current density of 3 A / m ^{2 in} a 0.2N hydrochloric acid solution, and then anodized in a sulfuric acid solution. did. At this time, the amount of anodization was 4 g / m ² . Further, the aluminum plate was sealed with a sodium metasilicate aqueous solution to prepare an aluminum plate used for a lithographic printing plate. Next, the following photosensitive solution-2 was applied on this aluminum plate to prepare a negative PS plate, and after graining, photosensitive solution-3 was applied to an anodized aluminum plate to obtain a positive PS plate. Coating is performed with a rotary coating machine and 100
Dry at 4 ° C. for 4 minutes. 2.5 g for both plates
/ m ² .

Photosensitive solution-2 N- (4-hydroxyphenyl) methacrylamide:
Acrylonitrile: ethyl acrylate: methacrylic acid = 27: 33: 41: 6 (weight ratio) copolymer (acid value 80)… 5.
Hexafluorophosphate of paraformaldehyde condensate of p-diazodiphenylamine: 0.5 g Julimer AC10L (trade name, manufactured by Nippon Junyaku Co., Ltd., acrylic acid polymer): 0.05 g Tartaric acid: 0.05 g・ Victoria Pure Blue BOH (trade name, dye, manufactured by Hodogaya Chemical Industry Co., Ltd.) 0.1 g Novolak resin (PP-3121) (manufactured by Gunei Chemical Co., Ltd.)
0.15 g-Pluronic L-64 (trade name, manufactured by Asahi Denka Co., Ltd., surfactant) ... 0.005 g-Methyl cellosolve ... 100 ml Photosensitive solution-3-Naphthoquinone- (1,2) -diazide- ( 2) Condensation diagram of -5-sulfonic acid chloride and resormine-benzaldehyde resin ...... 3.5 g ・ m-cresol formaldehyde novolak resin "MP
-707 "(manufactured by Gunei Chemical Industry Co., Ltd.) 9 g naphthoquinone- (1,2) -diazide- (2) -4-
Sulfonyl chloride ... 0.15 g ・ Victoria Pure Blue BOH (trade name, dye made by Hodogaya Chemical Industry Co., Ltd.) ... 0.2 g ・ Methyl cellosolve ... 100 g Negative type and positive type PS thus obtained plate was exposed using a 2K _w metal halide lamp through a step wedge of density difference 0.15. Thereafter, development processing was performed at 25 ° C. with an automatic developing machine using the following developer composition [III].

The developer [III] was diluted with 5 times the amount of water before use.

Developer composition [III]-Potassium silicate A (trade name, manufactured by Nippon Chemical Industry Co., Ltd.) Potassium silicate-450 g-Propylene glycol-25 g-Sodium hydroxide-165 g-pt-butyl benzoic acid- … 100g ・ β-anilinoethanol …… 25g ・ Sodium sulfite …… 50g ・ Emulgen 147 (trade name, Kao Corporation, nonionic surfactant) …… 1g ・ Nikkor defoamer No.20 (trade name, Nonionic surfactant manufactured by Nikko Chemicals Co., Ltd.) 25 g ・ Pure water 250 g The negative and positive PS plates were indiscriminately developed using the above-mentioned developer. Both plates were successfully developed. When the PS plate obtained by the development processing was subjected to printing by a printing machine, a good printed matter without stain was obtained for both the negative PS plate and the positive PS plate.

Example 3 A positive PS plate was produced in the same manner as in Example 1. Next, a developer composition [IV] and a comparative developer [V] were prepared as follows.

Developer composition [IV]-5.0 parts by weight of sodium silicate 3 (JIS sodium silicate)-5.0 parts by weight of water-2.0 parts by weight of p-tert-butylbenzoic acid-Nikkor defoamer No10 (manufactured by Nikko Chemicals Co., Ltd.)
0.1 part by weight 50% sodium hydroxide 2.8 parts by weight Comparative developer [V] A developer obtained by removing the defoaming agent from the above-mentioned developer [IV] was used as a developer [V] for comparison.

The dilution ratio of the above two developers with tap water is 5 times and 6 times 2
Processing was performed in an automatic developing machine in the same manner as in Example 1 at various dilution rates. However, the development temperature was 27 ° C. and the development time was 25 seconds. Table 2 shows the results.

As shown in Table 2, the developer [IV] of the present invention does not change much in the number of clear plates and the number of solid plates when the dilution ratio is 5 times or 6 times. On the other hand, when the dilution ratio of the comparative developer [V] is 5 times or 6 times, both the number of clear stages and the number of solid stages greatly vary.

〔The invention's effect〕

According to the present invention, it has been possible to provide an improved photosensitive lithographic printing plate developer composition having little change in developing property and little foaming.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-34156 (JP, A) JP-A-61-63842 (JP, A) JP-A-62-73270 (JP, A) JP-A 61-63270 63843 (JP, A) JP-A-64-44445 (JP, A) JP-A-64-44936 (JP, A) JP-A-63-202742 (JP, A) JP-A-1-129250 (JP, A) JP-A-63-169645 (JP, A)

Claims (1)

(57) [Claims] (1) An aqueous solution of an alkali silicate is prepared by adding an adduct of polyethylene oxide and polypropylene oxide of glycerin.
A developer composition for a photosensitive lithographic printing plate characterized by containing 0.001 to 10% by weight.