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
  • G03C1/76—Photosensitive materials characterised by the base or auxiliary layers
  • G03C1/825—Photosensitive materials characterised by the base or auxiliary layers characterised by antireflection means or visible-light filtering means, e.g. antihalation
• • 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
  • G03C1/76—Photosensitive materials characterised by the base or auxiliary layers
  • G03C1/775—Photosensitive materials characterised by the base or auxiliary layers the base being of paper
  • G03C1/79—Macromolecular coatings or impregnations therefor, e.g. varnishes
• • 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
  • G03C8/00—Diffusion transfer processes or agents therefor; Photosensitive materials for such processes
  • G03C8/42—Structural details
  • G03C8/52—Bases or auxiliary layers; Substances therefor

Definitions

• the invention relates to opaque water-resistant papers and methods of making such papers suitable for use as base material for light-sensitive coatings for photographic purposes. According to the invention a sealing coat is applied to the paper base to prevent damage to the paper by application of the other coatings particularly aqueous or waterbound coatings.
• the invention relates to opaque water-resistant papers and a method of making opaque water-resistant papers, suitable for use as base material for light-sensitive coatings, that is to say as paper-based emulsion supports, which, with the aid of a combination of coatings,-of which, on one side at least, one is light absorbent-are made waterproof on both sides and opaque on one side and are thus suitable, in particular, for use in self-developing cameras.
• the coating of raw paper with aqueous dispersions of plastics has disadvantages, however, which come to the fore particularly in diffusion transfer processes and affect the quality of photographs made with such papers.
• the action of water on the unprotected paper has an adverse efi'ect on the high-grade sheet and surface structure achieved by the paper making machine, in the production of raw paper, by contactdrying on cylinders. Because of the partial swelling of the fibers associated with the irregularity of raw paper, because of the raising of the surface fibers caused by water and because of the nonuniformity of stress resulting from free drying in tunnel or hanging frames at necessarily rather high temperatures, which, as is well known, detract from flatness, not only is the surface spoilt, but the structure of the sheet as a whole.
• the sealing coat may be applied by extrusion coating. All resins that can be extruded from the melt are suitable for this process. For preference, polyalkylenes with carbon-black fillers should be used.
• the thickness of the coating which will be determined by the structure of the paper as a whole and by the particular purposes for which it is required, should preferably be in the range 0.008 mm. to 0.02 mm.
• the sealing coat may also be applied within the papermaking machine by the use of water-soluble binders and/or aqueous dispersions of plastics.
• a material feature in this case is that the addition of waterbound colors is carried out only when the drained paper has dried sufficiently to be entirely free from stresses. After a brief predrying of the coating, the coated paper is then dried throughout with the aid of heated cylinders.
• the sealing coat in this case should preferably be in the range 0.005 mm. to 0.015 mm.
• the sealing coat be pigmented with titanium dioxide or carbon black, for example.
• Carbon black in particular is advantageous, in any technically usable portion, as regards the opacity required in the end product.
• the effect of electrical surface treatment is that there is practically no limit to the choice of binders for the outer coating.
• One binding medium that is to be preferred for lacquers is nitrocellulose, whereas preference should be given to mixed polyacrylate polymers and/or gelatine as the binding medium for coatings made from an aqueous phase.
• the thickness of the light-absorbent rear coating is approximately 0.015 mm. to 0.03 mm.
• Carbon black should preferably be used by way of light-absorbent pigment.
• Other light-absorbent substances may also be used, so long as they serve to provide or improve opacity.
• To test opacity the following method may be employed. A highly sensitive photographic paper (speed about 30/ DIN) is brought into contact with the test piece in a printing frame. An exposure of 1 minute is then given, with an intensity of illumination of approximately 25,000 lux. When the photographic material thus exposed is developed, the nonopaque portions show as black or grey dots on a white ground. Papers rendered opaque by the invention method show fewer then 10 pinhead-sized dots to the square meter.
• the opaque rear coating may have properties specially called for in particular cases.
• it may be antistatic, hot-sealing, matt and/or capable of being written upon.
• it may have special sliding properties, as is particularly necessary with certain self-developing cameras. These sliding properties are obtained either by the addition of the usual lubricating agents to the opaque coating or, preferably, by the application of a separate lubricating coating characterized by the fact of its containing, in addition to a suitable binder, finely dispersed graphite and/or finely dispersed tetrafluorethylene (co- )polymer.
• Papers coated for opacity in accordance with the invention are used in the self-developing camera as a base both for negative emulsions and also for positive emulsions. On the other side, accordingly, they cannot only be coated with ordinary white-pigmented lacquers or white-pigmented polyalkylene, but can also carry a coating of ordinary gelatine-sized barium sulfate.
• papers rendered opaque and water-resistant in accordance with the invention by extrusion-coating followed by lacquering or other coating, can be still further improved by calendering after the coating processes.
• the calendering is carried out either after the coating of the rear side or after completion of the base and should preferably be done with the aid of highly polished steel rolls.
• EXAMPLE I l A very smooth white, untreated photographic paper (approx. 80 g./sq.m.) is extrusion coated on one side with a mixture of polyethylene and carbon black (for example, 95:5 The thickness of the coating is approx. 0.012 mm. The surface of the polyethylene is electrically treated by corona discharge. 2. A standard lacquer made of nitrocellulose, softener, carbon black and solvent is applied to the coating of polyethylene and carbon black. The thickness of the dried coat of lacquer is approximately 0.025 mm. The content of carbon black is about percent in relation to the total solid.
• a lubricating coating consisting, for example, of colloidal graphite and ethyl cellulose in alcohol solution, is applied over the coating of lacquer.
• the paper coated on one side as in (1H3) above is extrusion-coated on the other side, in the conventional way, with a mixture of polyethylene and titanium dioxide (85:15,) to a thickness of approximately 0.025 mm.
• the surface is rendered matt and is electrically treated.
• This polyethylene coating is coated with a normal adhesive for light-sensitive emulsions.
• EXAMPLE ll An untreated photographic paper is painted on one side or both sides, in the usual way, within the paper making machine with a normal waterbound color containing, for example, clay and/or titanium dioxide (and perhaps also some carbon black) as the pigment, and reduced starch and a commercial latex (Dow Latex 5l2-R, for example) as the binder medium.
• the body content of the color and the addition of further secondary substances depend on the coating composition used and the condition of the color. It is of advantage to adjust the body content to 45-50 percent with the aid of a sizing press.
• the rate of application should preferably be 8 to 10 g./sq.m.
• a second coating device within the papermaking machine may be used to apply a 0.5-3 percent solution of a colloidal preparation of silicic acid (such as Ludox).
• a lacquer containing carbon black may be applied by conventional means, to give the paper whatever properties are desired in each particular case (such as sealability, low friction, acceptance of writing and so forth).
• the carbon black content of the lacquer is about 25 percent of the total solids.
• the coating is approximately 0.3 mm. thick.
• EXAMPLE Ill 1 A white photographic paper is given a sealing coat on one side, as in example I or II.
• a waterbound color containing carbon black is applied evenly with the aid of an airbrush, for example.
• the color contains a styrene/butadiene latex, which is film forming at room temperature, and by way of pigment a 3:2 mixture of titanium dioxide and carbon black.
• the ratio of pigment to binder is 3:2.
• a pigment-free lubricating coating is applied, consisting of ethylcellulose in alcohol/toluol, for instance.
• the front side may be coated as in examples I or ll.
• An improved photographic base paper consisting essentially of:
• a. paper sheet having a front side and back side
• said front side having adhered thereto a nonaqueous polyalkylene sealing coat of thickness ranging from about 0,005 to 0.02 mm. and containing from 0 to about 15 percent titanium dioxide pigment,
• said back side having adhered thereto a nonaqueous polyalkylene sealing coat of thickness ranging from about 0.005 to 0.02 mm. and containing from 0 to about 5 percent carbon black pigment,
• said front side sealing coat having adhered thereto a water proof plastic overlayer selected from polyalkylene plastic and lacquer containing titanium dioxide pigment
• said backside sealing coat having adhered thereto a water proof plastic overlayer selected from polyalkylene plastic lacquer and styrene/butadiene latex containing a pigment selected from carbon black and mixtures of carbon black and titanium dioxide
• said base paper having a relative mottling of less than about 3, an opacity of less than about 10 inhead-sized dots per square meter, and exhibiting improved tear characteristics for use in self-developing camera film.
• a base paper as in claim 2 which includes a photosensitive layer adhered to said front side overlayer.
• a base paper as in claim 2 which includes a lubricating coating applied to said back side overlayer.
• An improved photographic base paper consisting essentially of:
• a. paper sheet having a front side and a back side
• said front side having adhered thereto a nonaqueous polyalkylene sealing coat of thickness ranging from about 0.005 to 0.02 mm. and containing from 0 to about percent titanium dioxide pigment,
• said back side having adhered thereto a nonaqueous polyalkylene sealing coat of thickness ranging from about 0.005 to 0.02 mm. and containing from 0 to about 5 percent carbon black pigment,
• said back side sealing coat having adhered thereto a water proof overlayer selected from lacquer and styrene/butadiene latex containing a pigment selected from carbon black, titanium dioxide, and mixtures thereof, said overlayer having a thickness of about 0.6 mm., and
• said base paper having a relative mottling of less than about 3, an opacity of less than about I0 pinhead-sized dots per square meter, and exhibiting improved tear characteristics for use in self-developing camera film.

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• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• General Physics & Mathematics (AREA)
• Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Architecture (AREA)
• Structural Engineering (AREA)
• Paper (AREA)
• Laminated Bodies (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=7434849

Family Applications (1)

Country Status (7)

Cited By (2)

Families Citing this family (6)

• 1966
  • 1966-03-31 DE DE1696264A patent/DE1696264B2/de active Granted
• 1967
  • 1967-03-17 CH CH391567A patent/CH490695A/de not_active IP Right Cessation
  • 1967-03-21 US US624736A patent/US3615550A/en not_active Expired - Lifetime
  • 1967-03-22 GB GB03396/67A patent/GB1183613A/en not_active Expired
  • 1967-03-23 NL NL6704295A patent/NL6704295A/xx unknown
  • 1967-03-28 FR FR100410A patent/FR1515669A/fr not_active Expired
  • 1967-03-31 BE BE696382D patent/BE696382A/xx unknown

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