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
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S430/00—Radiation imagery chemistry: process, composition, or product thereof
  • Y10S430/14—Dimensionally stable material

Definitions

• the present invention relates to improvements in the method of obtaining photographic contrasts by means of diazonium compounds described in the co-pending application Ser. No. 612,364 filed May 19, 1932 of de Boer, Dlppel and Alink.
• a carrier is provided with a light sensitive substance which consists of one or more diazonium compounds of which compounds at least one, upon exposure to actinic light in the presence of water, forms a phenol so substituted in .the benzene nucleus, that the phenol can be oxidized either by the non-decomposed portion of that particular diazonium compound or by some other diazonium compound provided on the carrier.
• a colored compound is thus formed without the addition of an azo component, whereby the diazonium compound oxidizes the phenol produced during the exposure much more rapidly than it would couple therewith to form an azo dye.
• a suitable compound for printing paper is parahydroxy benzene diazoniumchloride, upon exposure of which hydroquinone, nitrogen and hydrochloric acid are formed.
• the process of making heliographic prints by means of a carrier provided with a light sensitive diazonium compound described in the above application consists in locally exposing such car- 'rier to a light having a strongly actinic efiect on the light sensitive substance, after which the whole carrier is subjected to a second exposure, this time to a light which is only slightly actinic with regard to the light sensitive substance of the "carrier, so that part of the diazonium compound is converted into a phenol and this phenol is caused to be oxidized by the non-converted portions of the diazonium compound to form a colored oxidation product.
• the oxidization may be accelerated by moderate heating to about 80 C.
• contrasts can be greatly promoted by the addition of copper salts, such as copper nitrate.
• Excellent contrasts are obtained on a positive print made from a positive, for instance from a drawing, if the paper serving as carrier is soaked in a 0.25% alcoholic solution of -1-hydroxy-2-diazo-4-benzene-sulphonic acid, to which 0.55% of copper nitrate is added. After the paper is dried, the print is made by exposing the so treated carrier under the drawing to the light of a suitable highly actinic light source, for
• the present invention relates to an improvement in the method of the'above application.
• light sensitive carriers for instance, printing paper
• printing paper are generally stored for a considerable time prior to their use they are generally kept in closed containers to prevent access of light. It has been found however that a light sensitive carrier, for instance, printing paper made according to the prior invention, when subjected to prolonged storage in such containers decreased in light-sensitiveness and after several months the paper'loses practically all of its light-sensitiveness.
• the present invention therefore, relates to a method of drying a light-sensitive material, for instance, heliographic printing paper, made accordingto the invention of the prior application, to remove from it the moisture to such extent that chemical reactions inducive to the deterioration of the light sensitive properties of the material be prevented and to maintain said material in such a dry state during its storage.
• a light-sensitive material for instance, heliographic printing paper
• the light sensitive material, made according to the invention of the prior applicatiompermanently deteriorates in the presence of even a small amount of mo1sture and to maintain its initial and maximum .light sensitivity it has to be dried and kept dry tained during its storage in such dry condition whereby the decomposition of the diazonium compound is altogether prevented and the light sensitiveness of the material made according to the invention of the prior application can be maintained to its full extent.
• a suitable paper after being sensitized by means of an alcoholic solution of a diazonium compound of the nature above described, is dried under vacuum until its moisture content has been reduced to the above extent.
• Another method provides for the drying of such a sensitized paper in an enclosure which has an atmosphere maintained perfectly dry by a powerful drying agent, for instance, by phosphorus-pentoxide.
• tized paper is placed in a container and flushed with a gas, for instance, nitrogen or air, from which all moisture has been extracted either by means of a powerful drying medium, for instance, phosphorus-pentoxide, or by freezing the moisture out at a very low temperature. For instance, from air moisture can be completely frozen out at about 180 C.
• a gas for instance, nitrogen or air
• containers for instance glass receptacles which are sealed by a moisture-proof compound, for instance, a suitable sealing wax, and which container does not comprise moisture at all or the moisture content of which is so low that the paper can absorb no such quantities of moisture which would increase its moisture content above 1%.
• a moisture-proof compound for instance, a suitable sealing wax
• the dried light sensitive material may be stored in hermetically-sealed metal boxes or containers consisting of thin metal plates, the edges of which are welded or soldered together, and which have been freed from moisture.
• the generally used wrapping means for instance, cardboard containers or paraflin impregnated paper wrappers, which are entirelysuitable containers for other light sensitive materials, are deficient as containers or wrappers for light sensitive material according to the prior application, and even if such light sensitivematerial has been sharply dried by one of the previously described methods, sufiicient moisture will gain access to it and gradually destroy its light sensitive properties.
• the light sensitive material when placed in the container is provided with a protective wrapping of ordinary paper or similar material, such wrapping paper has also to be dried to a similar extent as the light sensitive material.
• a light-sensitive material comprising a diazonium compound which upon exposure to actinic light in the presence of water forms a phenol which is oxidized by the unconverted portions of a diazonium compound and forms a colored compound without the addition of an azo-component, comprising the steps 01' providing a carrier with said diazonium compound and removing from said material the moisture so that it forms less than 1% of the weight of the material.
• a light-sensitive material comprising a diazonium compound which upon exposure to actinic light in the presence oi water forms a phenol which is oxidized by the unconverted portions of a diazonium compound and forms a colored compound without the addition or an azo-component, comprising the steps of providing a carrier with -said diazonium compound andremoving from said material the moisture so that it forms less than 1% of the weight the material and enclosing said material in an air tightly sealed container having a substantially moisture-tree atmosphere.
• the method 01 producing a light-sensitive material comprising a diazonium compound which upon exposure to actinic light in the presence of water forms a phenol which is oxidized by the unconverted portions of a diazonium compound and forms a colored compound without the addition of an azo-component; comprising the steps of providing a carrier with said diazonium compound and placing said material in a closed container, evac said container to remove from said material e moisture so that it; forms less than 1% o! the weight of the marial.
• a light-sensitive material comprising a carrier such as paper provided with a light-sensitive layer, in which the light sensitive substance comprises a diazonium compound which upon exposure to actinic light in the presence oi water forms primarily a phenol so substituted in the benzene subjecting said material.

Landscapes

• 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)
• Packages (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=19750216

Family Applications (1)

Country Status (5)

• 0
  • NL NL38022D patent/NL38022C/xx active
  • FR FR745438D patent/FR745438A/fr not_active Expired
  • BE BE392172D patent/BE392172A/xx unknown
• 1932
  • 1932-11-03 GB GB31026/32A patent/GB391052A/en not_active Expired
  • 1932-11-10 US US642124A patent/US1973788A/en not_active Expired - Lifetime

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