DE3338338A1 - Developer solution for positive-working presensitised offset printing plates - Google Patents

Abstract

An aqueous developer solution for positive-working presensitised offset printing plates having a photosensitive layer containing o-quinone diazide contains (a) an alkali-metal silicate and (b) a water-soluble organometallic surfactant.

Description

DEVELOPMENT SOLUTION FOR POSITIVE WORKERS, PRESENSITIZED PEOPLE

FLAT PRINT FORMS DEVELOPER SOLUTION FOR POSITIVE WORKERS, PRESENSITIZED FLAT PRINT FORMS The invention relates to an improved developer solution for developing positive working, presensitized planographic printing forms with an o-quinonediazide compound as a photosensitive component.

When o-quinonediazide compounds are irradiated with actinic light As is known, the diazo group decomposes and carboxyl group-containing substances are formed Links. During imagewise exposure and processing with an alkaline The developing solution therefore becomes the o-quinonediazide-containing photosensitive layer in the exposed areas removed while the non-exposed areas under Generation of an image lagging behind.

For this reason, o-quinonediazide compounds are widely called so-called positive working photosensitive components in the photosensitive layer of presensitized plates or in photoresist compositions for photoetching been used. Mixtures of an o-quinonediazide compound and an alkali-soluble one Resins have proven particularly advantageous and economical. For example are compositions of an o-quinonediazide compound and a phenol-formaldehyde novolak or a cresol-formaldehyde condensate has been used extensively.

As a developer for light-sensitive layers, the o-quinonediazides of this type contain, for example, aqueous solutions of tertiary sodium phosphate, sodium hydroxide, Sodium silicate, potassium silicate or ammonium silicate used alone or in combination. Aqueous solutions of sodium hydroxide, sodium tertiary phosphate or the like have, however, in the development of photosensitive materials with a metal support the disadvantage that they have a strong etching effect on the metal, e.g. aluminum, in Exercise depending on the development time. In addition, these enable aqueous Solutions extremely poorly reproducible development results and in some cases the images are already slightly exceeded the development time removed. Since the developability of these aqueous solutions with repeated Use can be severely impaired with a certain volume of these solutions only a limited amount of photosensitive materials can be developed (low Processing capacity).

Recently, there are aqueous solutions of sodium silicate or potassium silicate been used. These solutions have only a slight etching effect on metals. In addition, their ability to develop can be reduced to a certain extent by setting the Ratio of silicon oxide (SiO2) to sodium oxide (Na2O) or potassium oxide <K20) (generally expressed as the molar ratio SiO2 / Na2O or SiO2 / K2O), where the Oxides are constituents of sodium silicate or potassium silicate, and by adjusting whose concentration can be regulated. As the SiO2 content increases, so does the developability slowed down, but development stability increases. With increasing content of Nu 20 or K 20 increases developability while developing stability decreases. Development stability "refers to the stability of the image the development time, understood.

If you only increase the content of Na2O or K2O, there is a risk that the image is removed after a short development time.

Because the processing capacity of a certain volume of the developer solution with the content of Na2O or K2O increases, a sufficient processing capacity can be found together with a certain development stability and developability, considering the total concentration of the silicate by properly adjusting the ratio SiO2 / Na2O or SiO2 / K20 increased. However, this is still insufficient because even with satisfactory development ability the stability of the Developer is unsatisfactory.

On the other hand, if the development stability is usable, there is the developability and processing capacity insufficient.

In addition, since relatively high concentrations are used, form It is easy to precipitate and neutralize the consumed liquid a large amount of acid is required.

Well-known developer solutions that contain sodium hydroxide, tertiary sodium phosphate, Containing sodium silicate, potassium silicate or the like thus have the following disadvantages: increased base strength leads to insufficient stability, although the developability and processing capacity increase. To have sufficient development stability To achieve, the alkali concentration must be reduced, which is insufficient Processing capacity. Therefore, if sufficient development stability is achieved with a high base strength, a developer solution with excellent Developability and processing capacity.

A method for achieving sufficient development stability with a high base strength is described in JP-OS 51324/75. This is where the developer solution an anionic or amphoteric surfactant added.

Another method for achieving sufficient development stability with high base strength is described in JP-OS 142528/81, the solution being a water soluble cationic polymer is added. Both developer solutions have however, the disadvantage that in the spray development using an automatic Development machine the developer solution tends to foam.

In JP-OS 25100/80, which corresponds to CA-PS 1145190, is the addition of an ionic compound of a group IIA transition element, IIIA or IIIX of the periodic table. Although this addition is a roughness of the anodized aluminum support suppressed by the strong base, the development stability is insufficient.

The object of the invention is therefore to provide a developer solution for positive working, presensitized planographic printing plates with excellent developability, Development stability, processing capacity and low tendency to foam provide.

It has now been found that it is an excellent aqueous developing solution is obtained when an aqueous solution of an alkali silicate is a water-soluble organometallic surfactant adds. The invention therefore relates to an aqueous one Developer solution for positive working, presensitized planographic printing plates with an o-quinonediazide-containing photosensitive layer which is (a) an aqueous Alkali silicate solution and (b) a water-soluble organometallic surfactant.

Examples of alkali silicates which can be used according to the invention are sodium silicate, Potassium silicate, lithium silicate, ammonium silicate, amine silicate and combinations thereof. The SiO2 / M2O (M equals alkali metal) molar ratio of the alkali silicate is preferably 0.5: 1 to 3.0: 1, in particular 1.0: 1 to 2.0: 1. At a molar ratio greater than 3.0: 1 will decrease developability while at molar ratios of less than 0.5: 1 the base strength increases so that aluminum plates or the like commonly used as supports for presensitized planographic printing plates be etched.

The concentration of the alkali silicate in the developer solution is preferably 1 to 10, in particular 1.5 to 7% by weight.

At a concentration of more than 10% by weight, they form Rainfall or crystals and when the used liquid is neutralized it occurs for gel formation. On the other hand, at concentrations of less than 1% by weight developability and processing capacity.

The water-soluble organometallic used according to the invention Surfactants are surfactants that have a metal in the molecule other than an alkali metal contain. Preferred metals contained in the surfactant molecule are e.g. Si, Ti, Sr, Zr and Ge, with Ti and Si being particularly preferred. The water-soluble organometallic Surfactants can be, for example, cationic, anionic, non-ionic or high molecular weight be organometallic surfactants.

Examples of water-soluble organometallic surfactants which can be used according to the invention are described in “Surfactants Handbook” (published by Kogaku Tosho Kabushiki Kaisha and Kagaku Kogyo), Vol. 19, p. 147 (1966). Preferred examples are given below: (a) (C2H5) 3Si (CH2) nCOOH, (b) C6H5 (CH3) 2Si (CH2) 2COOH, (c) (CH3) 3Si (CH2) 2COOH, (d) HOOCC2H4Si (CH3 ) 2O (CH3) 2SiC2H4COOH, (e) (C113) 3SiOSi (CH2) 2SCH2COOH, (f) [(CH3) 3SiO2] 2Si (CH3) (CH2) 3OSO H, (g) (C4H9O) 2Si (OC2H4NH2) 22RCOOH (h) [(Cl2H25NH2) 4Si] Ct4, (i) [(CH3) 3SiO] 3Si (CH2) 3NH (CH2) 2NH2, (k) HO (C2H4O) 3SiC2H4COO (C2H4O) 3H, (l) (CH3) 3SiC6H4OC2H4OH, (m) C18H37Si [O (C2H4O) pH] 3, (n) (CH3O) 3TiO [Ti (OCH3) OCO17H35] nOTi OCH3) 2, (p) Si [(OCH2CH2) pOR] 4, (q) [RO (CH2CH2O) p] 2Ti (OC4H9) 2, Si or Ti can be replaced in these compounds by Ti or Si or by Ge, Zr or Sn. In these compounds, R and R 'denote hydrogen atoms or substituted or unsubstituted alkyl groups having 1 to 25 carbon atoms, m, n and 1 have a value of 1 to 5 and p, q, and s have a value of 1 to 50. The water-soluble organometallic surfactants are used in amounts of 0.001 to 0.5, preferably 0.003 to 0.3% by weight, based on the weight of the developer solution.

The photosensitive o-quinonediazide layer on which the invention Developer solution is applied is a photosensitive copy layer that contains as a photosensitive component an o-quinonediazide compound, the alkali thereof solubility increases upon exposure to actinic light.

The positive working, presensitized plate made with the inventive Developing solution is essentially comprised of an aluminum plate and a photosensitive layer made of an o-quinonediazide thereon. Suitable Aluminum supports are e.g. panels made of pure aluminum or aluminum alloys. Even Plastic films with aluminum laminated on or vacuum vapor deposited can be used be used. The surface of the aluminum plate can be in several ways pretreated, e.g. by graining, dipping in aqueous solutions of sodium silicate, Potassium fluorozirconate or phosphate or by anodic oxidation. Are suitable Also aluminum plates that are grained and then placed in an aqueous sodium silicate solution Were immersed, and aluminum plates that are anodized and then placed in an aqueous Sodium silicate solution (U.S. Patent 3,181,461). The anodic oxidation can for example, by using an aluminum plate as an anode conducts a current through an electrolytic bath, which consists essentially of an aqueous or non-aqueous solution of an inorganic acid, such as phosphoric acid, chromic acid, Sulfuric acid or boric acid, or an organic acid such as oxalic acid or sulfamic acid, or whose salt consists. Also the galvanic described in US-PS 3658662 Deposition of silicate can be used.

Aluminum supports that are electrolytically grained (US-PS 4087341, JP-AS 27481/71 and JP-OS 30503/72) and then anodized are also suitable. More usable Carriers are aluminum plates that by graining, chemical etching and subsequent anodic oxidation (U.S. Patent 3,834,998). Such hydrophilization treatments are not just that applied to make the support surface hydrophilic, but they also prevent it an undesirable reaction of the photosensitive composition applied thereto and improve the adhesion between the support and the photosensitive layer.

The light-sensitive applied to the hydrophilic surface of the support Layer contains an o-quinonediazide compound. Particularly preferred o-quinonediazides are o-naphthoquinonediazide compounds, as for example in US-PS 3046110, 3046111, 3046121, 3046115, 3046118, 3046119, 3046120, 3046121, 3046122, 3046123, 3061430, 3102809, 3106465, 3635709 and 3647443 are described. Preferred o-naphthoquinonediazides are o-naphthoquinonediazide sulfonic acid ester or o-naphthoquinonediazide carboxylic acid ester of aromatic hydroxy compounds and o-naphthoquinonediazide sulfonic acid amides or o-naphthoquinonediazide carboxamides of aromatic amino compounds. Particularly these are preferred by esterifying a pyrogallol / acetone condensate with o-naphthoquinonediazide sulfonic acid obtained product (U.S. Patent 3,635,709); that by esterification of a hydroxyl group-containing Polyester with o-naphthoquinonediazide sulfonic acid or carboxylic acid obtained product (U.S. Patent 4,028,111); that by esterification of a homopolymer of p-hydroxystyrene or a copolymer of p-hydroxystyrene and another copolymerizable monomer with o-naphthoquinonediazidecarboxylic acid obtained product (GB-PS 1494043) and the by amidation of a copolymer of p-aminostyrene and another copolymerizable Monomer obtained with o-naphthoquinonediazide sulfonic acid or carboxylic acid (U.S. Patent 3,759,711).

Although these o-quinonediazide compounds can be used alone, preferably mixed with one alkali-soluble resin and uses this mixture as a photosensitive layer. Suitable alkali-soluble Resins are e.g. styrene-maleic anhydride copolymers and phenolic resins of the novolak type, especially phenol-formaldehyde; o-cresol-formaldehyde and m-cresol-formaldehyde resins. The mixture described in US Pat. No. 4,123,279 is particularly preferably one of the following called phenolic resins with a condensate of phenol or cresol, which by a Alkyl radical of 3 to 8 carbon atoms are substituted with formaldehyde, e.g.

t-butylphenol-formaldehyde resin. The amount of alkali-soluble resin is about 50 to 85, preferably 60 to 80 wt .-%, based on the weight of the photosensitive layer, the remainder of the layer being the o-quinonediazide compound is.

Optionally, the light-sensitive containing the o-quinonediazide Layer contain further additives, e.g.

Dyes, plasticizers and print-out agents. These materials are known and not limited to the examples below.

Dyes are used to mark the image area after exposure and developing the presensitized plate to contrast with the non-image area (the support surface) to give. Preferred dyes are alcohol-soluble Dyes such as C.I. 26, 105 (Oil-Red RR), C.I. 21, 260 (Oil Scarlet No. 308), C.I. 74, 350 (oil blue), C.I. 52, 015 (methylene blue) and C.I. 42, 555 (crystal violet).

These dyes are used in sufficient quantities to produce a clear color contrast between the hydrophilic surface of the uncovered support and the rest of the photosensitive layer. Generally amounts to the amount of dye no more than about 7% by weight, based on the total weight of the photosensitive composition.

Plasticizers are used to increase the flexibility of the light sensitive Increase layer on the support. Examples of suitable plasticizers are phthalate esters, such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dioctyl phthalate, Octyl capryl phthalate, dicyclohexyl phthalate, di- (tridecyl) phthalate, butyl benzyl phthalate, Diisodecyl phthalate and diallyl phthalate; Glycol esters, such as dimethyl glycol phthalate, Ethyl phthallyl ethyl glycolate, methyl phthallyl ethyl glycolate, butyl phthallyl butyl glycolate and triethylene glycol dicaprylate; Phosphate esters such as tricresyl phosphate and triphenyl phosphate; aliphatic dicarboxylic acid esters, such as diisobutyl adipate, dioctyl adipate, dimethyl sebacate, Dibutyl sebacate, dioctyl azelate and dibutyl maleate; Polyglycidyl methacrylate; Triethyl citrate; Glycerol triacetyl ester; and butyl laurate. The amount of plasticizer is no more than about 5% by weight based on the total amount of the photosensitive composition.

The expression means is used to immediately after the pictorial Exposure of the photosensitive layer of the presensitized plate to a visible one Image to yield.

Examples are the pH indicators described in GB-PS 1041463, the combination of o-naphthoquinonediazide-4-sulfonyl chloride described in US Pat. No. 3,969,118 with a dye and the photochromic compound described in JP-AS 6413/69. In addition, the cyclic acid anhydrides described in US Pat. No. 4,115,128 can be added to the photosensitive layer to increase its sensitivity.

The photosensitive composition containing o-naphthoquinonediazide is applied to the carrier as a solution in a suitable solvent. Usable Solvents are, for example, glycol ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether and 2-methoxyethyl acetate, ketones such as acetone, methyl ethyl ketone and cyclohexanone, and chlorinated hydrocarbons such as ethylene dichloride.

The amount of photosensitive layer applied to the support is about 0.5 to 7, preferably 1.5 to 3 g / m 2.

The positive-working, presensitized one obtained is exposed to light Plate with actinic light made of a carbon arc, mercury, metal halide, Xenon or tungsten lamp through an image-bearing slide, the exposed ones are exposed Areas soluble in alkali. Accordingly, the exposed area becomes the photosensitive Layer washed away by aqueous alkaline solutions and the hydrophilic support surface is exposed.

When the developer solution according to the invention is used, the following are achieved Advantages achieved: it increases the development stability so that a slight Control of development conditions is possible. The processing capacity will increased so that a large amount of photosensitive material with a small Amount of developer solution can be developed. The amount of liquid used is so small that wastewater treatment does not cause any problems.

The following examples illustrate the invention. All parts and percentages relate to weight, unless otherwise stated.

Example 1 o, 8 part of a naphthoquinone-1, 2-diazido-5-sulfonic acid polyhydroxyphenyl ester, obtained by polycondensation of acetone and pyrogallol (JP-AS 28403/68; U.S. Patent 3,635,709), 2.2 parts of a m- and p-cresol-formaldehyde novolak resin, 0.02 Part of an octylphenol novolak resin, 0.08 part phthalic anhydride, 0.08 part 2-trichloromethyl-5- (p-butoxystyryl) -1.3, 4-oxadiazole and 0.03 Part of crystal violet p-toluenesulfonate are in a mixture of 20 parts of methyl cellosolve acetate and 8 parts of methyl ethyl ketone mixed to a photosensitive solution.

A 0.3 mm thick aluminum plate grained with a nylon brush is etched with alkali and then electrolytically etched in aqueous nitric acid. The plate is then anodized in 10% aqueous sulfuric acid (amount of oxide film formed: 2.7 g / m2) and treated with a 1% aqueous zinc acetate solution from 700C. The plate is then thoroughly washed and dried.

A slinger is used on the treated aluminum plate the photosensitive solution obtained above applied and dried, whereby a positive working, presensitized planographic printing form with a photosensitive one Layer received in an amount of 2.0 g / m2. This presensitized plate will using a vacuum frame in close contact with a step wedge of a Density difference of 0.15 and a halftone dot wedge. Then exposed the plate with a 2 kW metal halide lamp.

Separately, developer solutions are prepared by adding the compounds listed in Table 1 to 1 liter of a 2% aqueous sodium silicate solution with an SiO2 / Na2O molar ratio of about 1.1. Table 1 Solution no. Connection (1) connection 2 CH3 CH3 CH3 # # # 1 CH3 SiO - # - SiO - # - # - SiO - # - Si-CH3 0.03 part # # # m, n = 1 - 5 CH3 CH3 m # np = 10 O (CH2CHO) p (CH2CH2O) qH q = 20-30 # CH3 CH3 CH3 CH3 CH3 CH3 # # # # # Tetrasodium ethylene 2 CH3-SiO - # - SiO - # - # - SiO - # - # - SiO - # - Si-CH3 0.015 part diamine tetraacetate # # # # # m, n, l = 1 - 5 (4H2O) CH3 CH3 m # n R l CH3 p = 20 - 30 0.5 part (CH2) 3O (CH2CH2O) pH CH3 CH3 CH3 CH3 # # # # 3 CH3H27- (OCH2CH2) pO (CH2) 3-SiO - # - SiO - # - # - SiO - # - Si- (CH2) 3-O- (CH2) 3-O- (CH2CH2O) qH # # # # CH3 CH3 m # CH3 0.05 part (CH2) 3O- (CH2CH2O) pH m, n = 1 - 5 p = 20-30 Table 1 (continued) Solution no. Connection (1) connection (2) CH3 CH3 CH3 CH3 m, n = 1 - 5 trisodium nitrilo- # # # # p = 10 triacetate 4 CH3-SiO - # - SiO - # - # - SiO - # - Si-CH3 q = 20 - 30 # # # # CH3 CH3 m # n CH3 (CH2) 3O- (CH2CHO) p (CH2CH2O) qC4H9 # CH3 0.01 part 0.1 part # (OCH2CH2) pOH # # # p, q = 20 - 30 5 H7C3O - # - Ti --- O ------- # - C3H7 0.03 part # # # (OCH2CH2) qOH # 6 (CH3) 3Si (CH2) COOH 0.03 part disodium methylene diamine tetraacetate 0.1 part 7 (CH3) 3Si (CH2) 4COOH 0.05 part trisodium nitrilo- triacetate 0.1 part Comparative Example 1 No addition No addition

Two presensitized plates that have been exposed and printed are immersed in each of the developing solutions kept at 250C. A plate is removed after 1 minute, the other after 5 minutes. Then you wash them Plates with water. Table 2 shows the solved levels and halftone dot reproducibility of the highlight areas of the halftone dot wedge.

Table 2 Example of the number of steps in the step wedge 1 min. 5 min Development Development 1 3 4 150 lines / 2.54 cm, 2% halftone dots are at 5 Min.

Reproduced development.

2 3 4 3 3 4 II 4 3 4 5 3 4 6 3 5 7 3 4 11 Comparative example 1 6 13 150 lines / 2.54 cm, 2% halftone dots at 5 min.

Development not reproduced.

The results of Table 2 show that the developing solutions No. 1 to 7 in comparison to Comparative Example 1, where an aqueous sodium silicate solution is used independently, have extremely good development stability. In terms of processing capacity, the developing solutions No. 1 and No. 1 retain 2 even after developing 3 m2 / liter of presensitized panels, an ex- reaching Development ability.

Example 2 The procedure of Example 1 is repeated but used the developer solutions No. 8 to 14. These solutions are using a 2.5% aqueous potassium silicate solution with an SiO2 / K2O molar ratio of 1.2 instead of the sodium silicate in developer solutions No. 1 to 7. The same results as in Example 1 are obtained.

Claims (12)

Claims 1. Aqueous developer solution for positive working, presensitized planographic printing plates with a photosensitive containing o-quinonediazide Layer, indicated that it is (a) an aqueous alkali silicate solution and (b) contains a water soluble organometallic surfactant. 2. developer solution according to claim 1, characterized in that the Alkali silicate sodium silicate, potassium silicate, lithium silicate, ammonium silicate and / or is an amine silicate. 3. developer solution according to claim 1 or 2, characterized in that that the alkali silicate has a SiO2 / M20 molar ratio of 0.5 to 3.0: 1, where M is an alkali metal. 4. developer solution according to claim 3, characterized in that the Alkali silicate has an SiO2 / M2O molar ratio of 1.0 to 2.0: 1, where M is an alkali metal is. 5. developer solution according to one of claims 1 to 4, characterized in that that the concentration of the alkali silicate in the developer solution is 1 to 10% by weight amounts to. 6. developer solution according to claim 5, characterized in that the The concentration of the alkali silicate in the developer solution is 1.5 to 7% by weight. 7. developer solution according to one of claims 1 to 6, characterized in that that the water-soluble organometallic surfactant is selected from ionic, nonionic and high molecular weight organometallic surfactants that are a metal the group Ti, Si, Sn, Zr and Ge included. 8. developer solution according to claim 7, characterized in that the water-soluble organometallic surfactant is selected from those in the description compounds of the formulas (a) to (aa) mentioned. 9. developer solution according to claim 8, characterized in that in these water-soluble organometallic surfactants Si or Ti by Ti or Si or may be replaced by Ge, Zr or Sn, R and R 'hydrogen atoms or optionally substituted alkyl groups of 1 to 25 carbon atoms, m, n and 1 are one Value from 1 to 5 and p, q, around s have a value from 1 to 50. 10. developer solution according to one of claims 1 to 9, characterized in that that they use the water-soluble organometallic surfactant in an amount of 0.001 to Contains 0.5% by weight. 11. developer solution according to claim 10, characterized in that they use the water-soluble organometallic surfactant in an amount of 0.003 to 0.3 Contains wt .-%. 12. Development process, characterized in that one imagewise exposed, positive working, presensitized printing form on an aluminum carrier has a photosensitive layer containing an o-quinonediazide compound, treated with an aqueous developer solution according to any one of claims 1 to 11.