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
  • G03C1/85—Photosensitive materials characterised by the base or auxiliary layers characterised by antistatic additives or coatings

Definitions

• the invention relates to a photographic material which contains at least one silver halide emulsion layer on one side of a polyolefin-coated paper base and an antistatic layer on the other side of the base.
• the antistatic finish prevents the light-sensitive layers of a photographic material from being impaired by so-called flashing, which can be caused, for example, by electrical discharges during transport of the material during casting, during assembly or in processing devices.
• Static electrical charges can be caused, for example, by the friction of the photographic material on the rollers or other parts of the device through which the material passes, or by contact with rough surfaces.
• the photographic material is through electrostatic discharges exposed. Irregular stripes, lines or dark spots then appear after the photographic processing.
• the electrostatic charging of the surface of a photographic material can be prevented by adding matting agents to the protective layers, which reduce the adhesion of two materials lying on top of one another. Once a charge has been created, it can be removed using electrically conductive additives. You can also combine both options.
• a disadvantage of the known antistatic layers is the lack or inadequate development of properties which are particularly important for photographic materials, in particular those which are to be processed by machine. This includes a high resistance to abrasion on the transport rollers during the application of the emulsion layers or when going through so-called printers, the fact that the antistatic properties cannot be influenced by photo photographic processing fluids, and the safety from contamination of these fluids by components of the antistatic layer, no sticking of the A ntistatik für, even at high winding friction as well as good printability and writability with the usual pastes or inks including ballpoint pen pastes.
• a particularly disturbing disadvantage of the known antistatic layers is their contamination in roller transport developing machines. Especially in machines that are designed for processing sheet material and that contain textile-covered rollers, dirt films from developer oxidation products are deposited on the back of the processed material, especially when starting up the machines and at low throughputs.
• the invention has for its object to develop an antistatic layer with the abrasion resistance required for machine processing of the photographic material, which is also printable and writable and which enables machine processing of sheet material without the disadvantages described above.
• Sodium magnesium silicates suitable as antistatic agents (A) are commercially available.
• the composition of an excellently suitable sodium magnesium silicate is:
• the rest is structured water.
• the succinic acid half-ester compounds described are compounds which can be prepared in a simple manner by known processes, the compounds denoted by R 1 Part within the scope of the definition given for R 1 has relatively little influence on the properties of the compounds of interest for the present application.
• succinic acid semi-ester compounds contain as R 1 one of the monounsaturated aliphatic radicals -C 12 H 23 , -C 15 H 29 or -C 18 H 35 , the formation of which can be explained by multiple addition of propylene.
• succinic acid half-esters The preparation of succinic acid half-esters is generally known and can be carried out very simply by esterification of alcohols with succinic anhydrides using acidic or basic catalysts (e.g. diazabicyclooctane).
• acidic or basic catalysts e.g. diazabicyclooctane
• the production is e.g. B. in BE-PS 756 476, CA-PS 835 420 or US-PS 3,689,271.
• the succinic acid semiesters can be used individually or as a mixture of several of these compounds. They are expediently used as oil / water emulsions. Together with the sodium magnesium silicate, these emulsions provide particularly adhesive and abrasion-resistant layers.
• the antistatic layer according to the invention contains 30 to 150 mg per m 2 of the mixture of sodium magnesium silicate and polystyrene sulfonic acid sodium (A) and preferably 30 to 100 mg / m2, and 40 to 200 mg / m z , preferably 80 to 120 mg / m 2 , Succinic acid semi-ester (B).
• the mixing ratio of sodium magnesium silicate and sodium polystyrene sulfonate in parts by weight can be 0.5: 1 to 12: 1 and is preferably 4: 1 to 7: 1.
• the antistatic layer can contain the additives known for photographic auxiliary layers.
• additives known for photographic auxiliary layers include natural or synthetic binders, e.g. Proteins, cellulose derivatives, polysaccharides, polyvinyl alcohol, polyvinyl pyrrolidone, but especially gelatin, coating aids such as e.g. Wetting agents, matting agents or bactericides, further thickening agents such as cellulose sulfate or carboxymethyl cellulose.
• the usual agents such as the sodium salts of dioctyl sulfosuccinate, dibutylnaphthalenesulfonic acid, triisopropylnaphthalenesulfonic acid and in particular dodecylbenzenesulfonic acid are used.
• the present antistatic layers are applied in the usual way by dipping, spraying or knife coating applied to the back of the photographic support.
• pretreatment is recommended, for example by corona radiation in accordance with DE-AS 1 159 159.
• the photosensitive photographic silver halide emulsion layers and auxiliary layers can then be applied to the other side of the support.
• Papers which are coated with the polymer of an ⁇ -olefin having 2 to 20 carbon atoms e.g. with polyethylene, polypropylene or copolymers of ethylene and propylene.
• the antistatic layers of the invention are suitable for black and white as well as for color photographic materials, and the latter are preferred.
• the properties of the photographic layers are in no way adversely affected by the antistatic layer according to the invention.
• the antistatic properties of the layers according to the invention are impaired by the processing liquids used in conjunction with the photographic materials, nor the processing liquids by components of the antistatic layers according to the invention.
• the antistatic layers are outstandingly resistant to abrasion and are therefore advantageous for photographic materials which are intended for processing in machines equipped with textile rollers.
• composition of the antistatic casting solution 2.1 is changed as follows:
• Test method The tendency of an antistatic layer to pick up dirt when the photographic material passes through a processing machine is tested in the following way: A textile roller covered with a polypropylene fabric, which is in contact with a pressure roller made of steel, is immersed in a bowl filled with developer. The textile roller is driven by a motor. The developer is circulated via a thermo and tempered it to 30 ° C. A developer is used for the test, through whom air was passed for 2 days in preparation for the test. The degree of dirt pick-up is assessed using the number scale 1 (heavy soiling) to 5 (no noticeable soiling).
• 1 liter of the developer contains:
• the test of the abrasion is done in the following way: 1200 m of the inventive A ntistatik GmbH equipped material in a width of 8.9 cm are passed through a commercially available color printer. After the web of material has passed through the device, the surface of the rollers which have come into contact with the antistatic layer is checked and the amount of abrasion left on the surface is graded with 1 to 5, 1 "strong abrasion” and 5 "no abrasion "means.
• the printability and inscribability of the antistatic layers is checked as follows: The back of the material provided with the antistatic layer is printed on the one hand by means of typewriter types on a black ribbon and on the other hand labeled with a ballpoint pen. If the printing or lettering is flawless, the result is rated 5. The worse results get grades from 4 to 1.
• the surface resistance was determined in accordance with DIN 53482.
• succinic acid half-esters used replace the group -C 18 H 35 which stands for R 1 with one of the groups -C 12 H 23 and -C 15 H 29 mentioned on page 6, the results obtained are comparably advantageous.
• the results are shown in Table 2.
• the latices used for comparison are named in the table.
• the latices commercially available with solids contents of 33 to 55% by weight were each used at 30% by weight.

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

Applications Claiming Priority (2)

Publications (3)

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ID=6235190

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Citations (1)

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• 1984
  • 1984-05-08 DE DE19843416897 patent/DE3416897A1/de not_active Withdrawn
• 1985
  • 1985-04-26 US US06/727,551 patent/US4582783A/en not_active Expired - Fee Related
  • 1985-04-30 DE DE8585105192T patent/DE3565609D1/de not_active Expired
  • 1985-04-30 EP EP85105192A patent/EP0160912B1/fr not_active Expired
  • 1985-05-02 JP JP60093956A patent/JPS60249144A/ja active Pending

Patent Citations (1)

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