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
  • G03C5/00—Photographic processes or agents therefor; Regeneration of such processing agents
  • G03C5/18—Diazo-type processes, e.g. thermal development, or agents therefor
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03D—APPARATUS FOR PROCESSING EXPOSED PHOTOGRAPHIC MATERIALS; ACCESSORIES THEREFOR
  • G03D7/00—Gas processing apparatus

Definitions

• This invention relates to a process for developing photoprints on lacquered or unlacquered diazotype films or on lacquered diazotype papers by means of ammonia gas.
• Development generally is performed in a combined exposure and development apparatus in which the copying material is conveyed in contact'with the original around an exposure cylinder, then automatically separated from the original and subsequently passed through the development section, which is a chamber containing warm wet ammonia gas.
• the copying material In order to achieve smooth operation and a high copying performance, the copying material must be passed through the development section at least at the same speed as through the exposure section. Since reing materials in which the lightsensitive composition is embedded in a lacquer layer of cellulose ester or the like or in the cellulose ester film parts close to the surface. In this case, thedevelopment speed is considerably reduced by the required diffusion of ammonia and water vapor into'the lacquer layer. When using such transparent and translucent materials, it thus is often not possible to utilize the available copying performance of the exposure section of modern photoprinting apparatuses.
• the development speed can also be increased by increasing the ammonia partial pressure. This is done in the simplest way by taking ammonia gas from a cylinder. Normally, the ammonia gas is developed by vaporization of an aqueous concentrated ammonia solution. As described in US. patent specification No. 3,373,022, this development may be intensified by saturating the supply solution with nitrogen under pressure or by the addition of alcohol to the solution.
• lacquered or unlacquered diazotype films or of lacquered diazotype papers is not disclosed here as Well as an eifect of the alcohol other than the increase of the ammonia concentration in the gas chamber.
• the present invention provides a process by which photoprints on lacquered or unlacquered diazotype films or on lacquered diazotype papers can be developed with the use of ammonia more rapidly than has been possible hitherto.
• the present invention provides a process for developing photoprints on lacquered or unlacquered diazotype film or on lacquered diazotype papers, in which, prior to the action of the ammonia, the photoprint is exposed to an atmosphere which contains the vapor of an organic solvent or of a mixture of organic solvents.
• the azo dye image forms substantially more rapidly and achieves its full intensity.
• the surface of the lacquer layer in which the light-sensitive composition is embedded is swelled by the action of the solvent vapors so that diifusion of ammonia and water vapor into this layer and reaction of the layer constitutents can take place more rapidly.
• treatment with solvent vapor in accordance with the invention should begin prior to the action of ammonia in order to achieve a substantial reduction of the development time. It need not be completed, however, prior to the commencement of the action of ammonia but also may be continued within that time.
• the treatment temperature may range within wide limits and depends upon various factors, such as the type of the lacquer layer, the duration of treatment, the apparatus used and particlarly upon the nature and the vapor pressure of the solvent. In most cases, good results are achieved at temperatures in the range from about 30 to 90 C. Temperatures in the range from 40 to C. generally are preferred.
• solvents generally are used which, at standard conditions, boil below 200 C., preferably between 50 and 150 C.
• the nature of the solvent should be attuned to the type of the lacquer layer in which the diazotype compound is contained.
• the solvent should swell or soften the lacquer layer under the conditions of the treatment but not render it tacky.
• the suitability of a solvent or solvent mixture can be determined by simple preliminary tests, e.g. by dabbing the lacquer surface witha cloth soaked therewith. In order to achieve a particularly rapid and uniform action of the mixture of ammonia and water vapor later on, those solvents have proved particularly suitable which are at least partially miscible withwater.
• suitable solvents are: alcohols, such as methanol, ethanol, isobutanol, and n-amyl alcohol; ketones,” such as acetone or butanone; esters, such as ethyl acetate, n-butyl acetate, and ethylene glycol methyl ether acetategand ethers, such as ethylene glycol monomethyl ether and diisopropyl ether.
• alcohols such as methanol, ethanol, isobutanol, and n-amyl alcohol
• ketones such as acetone or butanone
• esters such as ethyl acetate, n-butyl acetate, and ethylene glycol methyl ether acetategand ethers, such as ethylene glycol monomethyl ether and diisopropyl ether.
• esters such as ethyl acetate, n-butyl acetate, and ethylene glycol methyl ether acetategand ethers
• mixtures of solvent vapors since, in this manner, it is possible to adjust to a desired vapor concentration or a certain dissolving or swelling action. It is also possible by suitable solvent combinations to produce mixtures which may be used for lacquer layers of different kinds. In most cases, it is also of particular advantage when the treatment atmosphere contains water vapor in addition to solvent vapors. Such vapor mixtures may be produced either from one vaporization source containing the liquid solvent mixture or from several vaporization sources for the iiidividual components.
• the mixing ratio in the" gas chamber preferably should be so adjusted that, in the case of condensation of liquid droplets on the lacquer layer, a homogeneous liquid phase is obtained.
• the solvent vapor should act from the sensitized side of the copying material; it thus advantageously acts only after exposure and separation of the original and the copying material.
• the treatment of the invention may be performed in a vapor chamber arranged before the development section. For reducing the duration of tre'atment,the solvent vapor may be blown from a slot die onto the copying material, for example.
• the treatment time further depends on various factors, e.g. on the temperature, the type of the lacquer layer, and the type of the solvent mixture.
• the necessary treatment time may vary between a few seconds and about 1 minute, depending on the conditions. It may be so adjusted by a suitable choice of the parameters that smooth operation is guaranteed in a combined continuous copying apparatus.
• Suitable diazotype materials which can be developed according to the process of the invention are lacquered and unlacquered photoprinting films and lacquered photopr-inting papers, e.g. cellulose acetate films,'lacquer ed polyesters or polycarbonate films, lacquered translucent papers or lacquered opaque photoprinting "papers, in which the light-sensitive composition is embedded in "the lacquer layer by diffusion sensitization or, in the case of films capable of diffusion sensitization, embedded in the surface of the film.
• lacquered and unlacquered photoprinting films and lacquered photopr-inting papers e.g. cellulose acetate films,'lacquer ed polyesters or polycarbonate films, lacquered translucent papers or lacquered opaque photoprinting "papers, in which the light-sensitive composition is embedded in "the lacquer layer by diffusion sensitization or, in the case of films capable of diffusion sensitization, embedded in the surface of the film.
• EXAMPLE 2 Translucent paperof a weight per square .r net er. of ,80 g, was coated on one side with the following solution: Cellulose acetate 'propionate' with a contentof about 58% of'propionic acid groups,-5% of acetic acid groups, and 1% of "hydroxyl I groups, and of an average molecular weight'* The lacquer was .dried for .l /z'minutes at C.” The lacquer-layer of a weight of-12 g./m. was sensitized with the solution described in Example l. I I
• EXAMPLE 3 Cellulose acetate film was coated with the following Three samples were taken from the diazotype material obtained and developed without exposure to light as follows: The first sample was passed three consecutive times through the development section of a commercial combined photoprinting machine adjusted to a speed of 1 m. per minute. The color density obtained was regarded as the maximum density to be achieved. The transmission density of the developed material was measured at ditferent places by means of a Kodak-Densitometer RT-230 with a green filter and the average value was determined from the values obtained. The second sample was passed once through the development section at a speed of 10 111. per minute and immediately thereafter was passed through the exposure section in order to interrupt the development operation. The density obtained was measured as above and was 75% of the maximum value.
• the third sample was suspended for two minutes in an exsiccator containing an atmosphere saturated with ethanol vapor at room temperature; It was then treated as the second sample. The color density obtained was 84%.
• the fourth sample was processed as was the third one but with the use of acetone vapor instead of ethanol. The density obtained was 93%. Prolongation of pretreatment with solvent vapor to 5 minutes involved a density increase to 88% in the case of ethanol and to about 97% in the case of acetone. In this case, the surface of the film treated with acetone was slightly tacky. The tackiness could be eliminated by using for this test the solvent atmosphere which forms above a mixture of equal parts of acetone and isopropanol.
• a process for developing two-component diazotype material comprising a film or paper support having a lacquer layer thereon or an unlacquered film which has a photosensitive composition embedded in the said lacquer layer or embedded in the surface of the said unlacquered film, said composition comprising a diazonium compound, an azo coupler, and an acidic stabilizer, which process comprises the steps of (A) exposing the photosensitive material imagewise to actinic light, (B) contacting the imagewise exposed material prior to development with an atmosphere containing at least one organic solvent in vapor form which swells or softens the film base and/or the lacquer layer but does not render them tacky during this treatment step, and (C) developing said diazotype material to form a dye image by contacting said diazotype material with ammonia gas.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)
• Inks, Pencil-Leads, Or Crayons (AREA)
• Photosensitive Polymer And Photoresist Processing (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=5796417

Family Applications (1)

Country Status (10)

Cited By (1)

• 1971
  • 1971-01-20 DE DE2102558A patent/DE2102558C3/de not_active Expired
• 1972
  • 1972-01-17 US US00218589A patent/US3794487A/en not_active Expired - Lifetime
  • 1972-01-17 CA CA132526A patent/CA920866A/en not_active Expired
  • 1972-01-17 AT AT37472A patent/AT311170B/de not_active IP Right Cessation
  • 1972-01-17 BE BE778147A patent/BE778147A/xx unknown
  • 1972-01-18 GB GB236272A patent/GB1372611A/en not_active Expired
  • 1972-01-18 IT IT47778/72A patent/IT948236B/it active
  • 1972-01-19 ES ES72399034A patent/ES399034A1/es not_active Expired
  • 1972-01-20 NL NL7200797A patent/NL7200797A/xx unknown
  • 1972-01-20 FR FR7201859A patent/FR2122542B1/fr not_active Expired

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