Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/52—Compositions containing diazo compounds as photosensitive substances
  • G03C1/56—Diazo sulfonates

Definitions

• This invention relates to the production of diazotype light sensitive layer wherein the lightsensitive agent is an aryl diazo-N-sulfonate and more particularly to the improvement of the stability and printing speed of such diazotype light sensitive layers.
• Reproduction media for the photoprinting of transparent or semi-transparent originals in which media the photosensitive material is a diazo compound are well known. They are generally produced by treating the surface of a suitable base, such as paper, with a solution of two dye components, one of which, the diazo component, is the photosensitive body and the other, known as the azo component or coupling component, is a compound capable of reacting under suitable conditions with the diazo component to form a dye.
• the diazo component of such a light sensitive layer decomposes upon exposure to light to a compound which can no longer combine with the coupling component to form a dye.
• 2,217,189 do not have as long a shelf life as the ammonia developable light sensitive layers coated with a solution of a diazo compound and an azo component. Furthermore, the coating solution is unstable and precipitates colored material after a short time which renders it un- This instability of the coating solution and shelf life of the coated paper can be improved by adding a quantity of sodium bisulfite to the coating solution as recommended in the patent. However, if sufficient 'sodium bisulfite is added to accomplish a commercially desirable stability and shelf life, the speed of printing by exposure to light is so retarded as to render the light sensitive layer unsuitable for any practical purpose.
• the coating solution can be sufficiently stabilized for all practical purposes and that the shelf life of the coated paper can be improved to an extent comparable with ammonia developable diazotype layers by adding ketones, ketonic acids or aromatic aldehydes or their substitution products, which will form addition products with bisulfites to the coating solution containing the diazo-N-sulfonate derived from a p-phenylene diamine, an
• ketonic acid is desirlight sensitive layer by adding at least molecularly equivalent amounts of the ketone, ketonic acid or aromatic aldehyde.
• Coating solutions which are stable for several days under ordinary ticularly adaptable to this process: Acetone, ketopentamethylene, cyclohexanone. acetonyl acetone, furfuraldehyde, levulinic acid, pyruvic acid, aceto acetic acid alkyl esters and benzaldehyde. It will be understood that the classification ketonic acids includes salts of such acids and their esters.
• a coating solution was prepared by stirring into solutionin 1,000 cc. of water:
• a zinc acetate precoated paper was coated with the above solution and dried in the usual manner. Samples of this coated paper were then exposed to light. under adiapositive and the thus exposed sensitized samples were developed by contact with heat. Qther samples of the unexposed, but coated paper together with the exposed and developed samples were then stored for the purpose of determining the stability of the light sensitive layer of the finished print. Similar tests were made at the same time on the same type of paper coated with a solution containing the same components as above with the exception of thebenzaldehyde. It was observed that the printing speed and stability of the papers coated with. the solution containing the benzaldehyde were far greater than the printing speed and stability of papers coated with the same solutionlacking. the benzaldehyde.
• a coating solution was prepared by stirring into solution in 1,000 cc. of water:
• Zinc acetate precoated paper samples were coated with this solution and dried in the usual manner. The same tests were made as i th e Of Example 1 and the. results compared with the results obtained from a paper coated with the same solution but omitting the acetone. It was found that the stability and light sensitivity or printing speed of paper coatings made with the solution of this example have the same improved characteristics as compared with the characteristics of the paper coated with the same solution lacking the acetone as were observed in the case of. Example I.
• a coating solution was prepared by stirring into solution in 950 cc. of water:
• Example II The resulting solution was coated on zinc acetate precoated paper and the coatings dried in the usual manner. Samples of these coatings were. then tested for stability'and sensitivity to light by exposing same'under a diapositive and developing the exposed light sensitive layers by heating. The thus exposed and developed prints and samples of unexposedcoatings were stored in the same manner as in Example I. It was found that the papers coated with the solution of this example had excellent characteristics as to stability and light sensitivity and showed a marked improvement over samples prepared from the same solution, but omitting the acetonyl acetone.
• a coating solution- was prepared by stirring into. solution in 950 cc. of water:
• a light sensitive layer on a suitable base comprising a mono diazo-N-sulfonate derivative of a p-phenylene diamine, an azo component, an alkali metal bisulfite, and a member of the group consisting of ketones, ketonic acids, and aromatic aldehydes Which form addition products withbisulfites.
• a light sensitive layer on a suitable base comprising a mono diazo-N-sulfonate derivative of p-phenylene diamine, an azo component, and an addition product of an alkali metal bisulfite with a member of the group consisting of ketones, ketonic acids and aromatic aldehydes which form addition products With bisulfites.
• a light sensitive layer on a suitable base comprising a mono diazo-N-sulfonate derivative of a p-phenylene diamine, an azo component, an alkali metal bisulfite and benzaldehyde.
• a light sensitive layer on a suitable base comprising a mono diazo-N-sulfonate derivative of a p-phenylene diamine, an azo component, an alkali metal bisulfite and acetone.
• a light sensitive layer on a suitable base comprising amono diazo-N-sulfonate derivative 01 a p-phenylene diamine, an azo component, an alkali metal bisulfite and pyruvic acid.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)

Priority Applications (4)

Applications Claiming Priority (1)

Publications (1)

Family

ID=23997952

Family Applications (1)

Country Status (4)

Cited By (10)

Families Citing this family (1)

Citations (5)

• 0
  • FR FR959577D patent/FR959577A/fr not_active Expired
• 1943
  • 1943-09-15 US US502466A patent/US2429249A/en not_active Expired - Lifetime
• 1947
  • 1947-12-29 GB GB34476/47A patent/GB641276A/en not_active Expired
• 1948
  • 1948-02-10 CH CH277044D patent/CH277044A/fr unknown

Patent Citations (5)

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