Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/09—Photosensitive materials characterised by structural details, e.g. supports, auxiliary layers
  • G03F7/095—Photosensitive materials characterised by structural details, e.g. supports, auxiliary layers having more than one photosensitive layer

Definitions

• This invention relates to a presensitized material for use in the preparation of printing plates and which comprises an aluminum support having a first layer thereon containing a water-soluble salt of a para-diazodiphenylamine, and a second water-insoluble layer on the first layer, the second layer containing more than 50 percent by weight of at least one light-sensitive para-benzoquinone diazide or para-benziminoquinone diazide.
• the materials heretofore known which have been photosensitized by a water-soluble salt of a para-diazodiphenyl amine, or of a para-diazodiphenyl amine derivative obtained therefrom by substitution or condensation with an aldehyde in addition to many advantages, also have the advantage that they can be developed with water or aqueous liquids which are completely free from organic solvents. This advantage can be fully exploited only in the case of moderately large sizes, up to about the double size of a usual sheet of note paper. With an increase in the size, the fingerprint sensitivity connected with the considerable water-solubility has proved disadvantageous since handling such larger sizes is almost impossible without damaging the reproduction layer.
• the reproduction layer has been coated with a water-insoluble coating consisting substantially of a resin capable of being plasticized by means of organic solvents, but this effort has resulted in presensitized printing plate material which can not be developed with aqueous solutions containing no organic solvent and thus is undesirable in many respects.
• the material also is superior to material not having such a coating in that higher runs can be achieved with printing plates prepared therefrom. This advantage probably is based upon the fact that a reaction occurs between the light-sensitive substances of both layers, upon exposure to light.
• the layer which contains the watersoluble light-sensitive diazonium salt and which is applied as an aqueous solution to the aluminum support is coated with the second water-insoluble light-sensitive layer containing at least one parabenzoquinone diazide or parabenziminoquinone diazide from a solution substantially free from water (i.e. containing less than 1 percent by weight of water in the solvent).
• the benzoquinone diazides and benziminoquinone diazides used in accordance with the invention for the formation of the coating are known and also their use as light-sensitive substances in the material for the preparation of printing plates is known, e.g. from German Pats. Nos.
• the coating may contain, in known manner, additives, such as resins, plasticizers, activators, pigments, and dyestutfs, even such dyestuffs as are indicators.
• additives such as resins, plasticizers, activators, pigments, and dyestutfs, even such dyestuffs as are indicators.
• the total weight of all additives should be less than that of the light-sensitive benzoquinone diazide or benziminoquinone diazide compound. If the coating contains more than one of the light-sensitive compounds, the sum of their weights should be more than half of the total weight of the layer.
• Suitable resins are, for example, epoxy resins, phthalic, alkyd, maleic, polyvinyl, polyacryl, polyvinyl acetate, melamine, urea, and chlorinated rubber resins.
• Suitable dyestufis are, for example, azo dyes, triphenylmethane dyes, and phthalocyanines.
• the aluminum support Prior to the application of the water-soluble light-sensitive layer, the aluminum support advantageously is, as is known, subjected to a mechanical, chemical or electrochemical pretreatment. Crude rolled aluminum, for example is cleaned with a hot alkali phosphate or alkali carbonate solution or with a solution containing nitric acid, nitrate, chromate, hydro-peroxide or another suitable oxidizing agent, or roughened by brushing or is electrolytically oxidized. Prior to the application of the water-soluble light-sensitive layer, the aluminum support also may be provided with a layer which improves the adhesive properties thereof, e.g. a layer of silicate, a polyacrylic acid or a phosphonic acid.
• a layer which improves the adhesive properties thereof e.g. a layer of silicate, a polyacrylic acid or a phosphonic acid.
• the known salts of para-diazodiphenyl amine or of the derivatives of para-diazodiphenyl amine which carry substituents at one or both phenyl nuclei there are employed the known salts of para-diazodiphenyl amine or of the derivatives of para-diazodiphenyl amine which carry substituents at one or both phenyl nuclei.
• Such diazonium salts may be present as double salts with metal salts, e.g. with zinc or cadmium salts, or as metal salt-free salts.
• the salts in the form of their condensation products with formaldehyde in the metal salt-free form Preferably employed are the salts in the form of their condensation products with formaldehyde in the metal salt-free form.
• the preparation of different kinds of condensation products and of light-sensitive layers containing such products, inter alia, is described in German Pats. Nos.
• the water-soluble reproduction layer may contain, in 'known manner, one or more of the aforementioned additives.
• EXAMPLE 1 A bright rolled aluminum foil which was cleaned by rinsing it for minutes with a trisodium phosphate solution at a temperature of 80 C. and immersing it for 3 minutes in a 5 percent sodium silicate solution at a temperature of 85 C. was dried and coated with a 1 percent aqueous solution of a zinc chloride salt of a diazo compound which had been prepared from 1 mole of 4-diazodiphenylamine and 1 mole of formaldehyde, by condensation in sulfuric acid, and dried.
• the presensitized printing plates obtained were insensitive to fingerprints and tropical working conditions and could be stored in the dark for many months.
• the exposed areas were not attacked by the developer even at working temperatures of about 35 C. After rinsing with water, the printing plate thus prepared was inked up with greasy ink. Long runs could be achieved therewith in a printing machine.
• EXAMPLE 2 An electrolytically-roughened aluminum tape which had been pretreated with a 1 percent polyacrylic acid solution was sensitized as in Example 1 with an aqueous solution of a condensation product of 4-diazodiphenylamine and formaldehyde. It was then coated with a solution of:
• EXAMPLE 3 An electrolytically-roughened aluminum tape which had been pretreated in known manner with a phosphonic acid solution was sensitized with an aqueous solution of 0.8 percent of a crude condensate prepared from 3-methoxy-diphenyl-amine-4-diazonium chloride and paraformaldehyde by condensation in phosphoric acid (the solution containing the phosphoric acid used for condensation) and 0.1 percent of polyvinyl acetate, and then was provided with coating from a solution of:
• the coating then was dried.
• EXAMPLE 4 An aluminum foil was pretreated, as in Example 1, and sensitized with the same aqueous solution. A solution of 0.8 percent of benzoquinone-(1,4)-diazide-(4)-2-(N-finap hthyD-sulfonarnide, and 99.2 percent of ethylene dichloride was then applied and dried.
• EXAMPLE 5 A mechanically roughened aluminum tape was chemically pretreated in a phosphonic acid bath and sensitized with a 0.6 percent aqueous solution of a condensation product of paraformaldehyde and diphenylamine-4-diazonium chloride. A solution was then coated thereon containing:
• EXAMPLE 6 An aluminum foil was pretreated, as in Example 3, and sensitized with the same aqueous diazo solution. The foil was then coated with a solution of:
• Example 3 a coating solution of 0.8 percent of the benzoquinone diazide of Example 3, 0.5 percent of polyvinyl acetal as in Example 3,
• a presensitized printing plate comprising an aluminum support, a first layer on the support comprising a light sensitive water-soluble salt of at least one compound selected from the group consisting of a para-diazodiphenylamine and a para-diazodiphenylamine condensed with an aldehyde, and a second water-soluble layer on the first layer, the second layer containing at least about 50 percent by weight based upon the total weight of the said second layer of at least one light-sensitive compound selected from the group consisting of a para-benzoquinone diazide and a para-benziminoquinone diazide the light decomposition products of the light-sensitive ingredients in both layers being insoluble in an aqueous developer solution.
• a process for making a printing plate which comprises exposing light-sensitive coatings on an aluminum support to light under a master and developing the said coatings with an aqueous developer to remove the unexposed areas of the said coatings, the coating comprising a first layer including a water-soluble salt of at least one compound selected from the group consisting of a para-diazodiphenylamine and a para-diazodiphenylamine condensed with an aldehyde, and a second Water-insoluble layer on the first layer, the second layer containing at least about percent by weight based upon the total weight of the said second layer of at least one light-sensitive compound selected from the group consisting of a para-benzequinone diazide and a para-benziminoquinone diazide.

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• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Structural Engineering (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Photosensitive Polymer And Photoresist Processing (AREA)
• Printing Plates And Materials Therefor (AREA)

Applications Claiming Priority (1)

Publications (1)

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ID=7229475

Family Applications (1)

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Cited By (7)

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Citations (6)

• 0
  • ZA ZA6705261D patent/ZA6705261B/xx unknown
• 1966
  • 1966-09-02 DE DE1522501A patent/DE1522501C3/de not_active Expired
• 1967
  • 1967-07-10 US US652024A patent/US3522042A/en not_active Expired - Lifetime
  • 1967-08-23 NL NL676711600A patent/NL151522B/xx not_active IP Right Cessation
  • 1967-08-30 AT AT796567A patent/AT272381B/de active
  • 1967-08-30 SE SE12026/67A patent/SE311596B/xx unknown
  • 1967-08-30 BE BE703277D patent/BE703277A/xx not_active IP Right Cessation
  • 1967-09-01 CH CH1226867A patent/CH481399A/de not_active IP Right Cessation
  • 1967-09-01 GB GB40097/67A patent/GB1192088A/en not_active Expired
  • 1967-09-02 JP JP5634067A patent/JPS5336364B1/ja active Pending

Patent Citations (6)

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