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
  • G03C1/81—Photosensitive materials characterised by the base or auxiliary layers characterised by anticoiling means
• • 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
  • Y10S430/131—Anticurl layer

Definitions

• the invention relates to a method for producing a layer support for light-sensitive materials with an anti-roll layer on the back.
• gelatin layers Most photographic materials use gelatin to build up the silver halide emulsions, protective layers and backing layers. Gelatin layers, however, swell with water and have little mechanical strength when swollen. For this reason, they are usually hardened using suitable hardening agents. The hardening agents crosslink the gelatin molecules with one another and thereby reduce the water absorption or swellability of the layer, increase the melting point and improve the mechanical strength of the gelatin layer. Hardened gelatin layers are above all resistant to the photographic treatment baths.
• the light-sensitive gelatin-containing layers on the front of the carrier material are usually opposite gelatin-containing layers on the back of the carrier material.
• the swelling behavior in the photographic treatment baths and the behavior of the layers during subsequent drying should be kept as identical as possible, so that the material maintains a good flatness during the entire working process and during later use.
• the layers applied to the back are therefore referred to as anti-roll or anti-curl layers, and their layer thickness depends on the swelling behavior and the layer thickness of the front-side coating.
• the anti-roll layers usually also contain various additives. These can be wetting agents such as saponin, matting agents such as silica, plasticizers such as glycerin, organic acids such as citric acid, small amounts of other water-soluble high-polymer compounds such as polyvinyl alcohol or antistatic agents such as sodium nitrate.
• wetting agents such as saponin, matting agents such as silica, plasticizers such as glycerin, organic acids such as citric acid, small amounts of other water-soluble high-polymer compounds such as polyvinyl alcohol or antistatic agents such as sodium nitrate.
• the resistance of the anti-roll layers to the photographic treatment baths is achieved by hardening the gelatin with so-called hardening agents.
• Known hardening agents for gelatin include chromium (III) salts, aldehydes, dialdehyde polysaccharides, polyfunctional epoxides, aziridines, polyfunctional vinyl compounds, triacryl formal, substituted dichlorostriazines and others in chapter 2 of the book "The Theory of the Photographic Process” by TH Substances described by James (London, 1977).
• the hardening agents are either added to the gelatin-containing solutions before processing or they are applied as a separate solution to the gelatin layer already on a support. In the second case, the hardening agents diffuse into the gelatin layer, where they react with the peptide chains. Both methods can also be combined with one another in such a way that part of the hardening agent is added to the gelatin solution and another part is subsequently applied to the layer.
• a method for producing a photographic material which consists of a flexible support which carries a hydrophilic, colloidal layer on one side and a special anti-roll layer on the other side.
• the anti-roll and the antistatic layer are applied by means of tandem engraving coating, the anti-roll layer containing a hydrophilic, colloidal substance and the antistatic layer containing an antistatic and a hardening agent which acts as a hardener for the hydrophilic, colloidal substance in the anti-roll layer and that the curing agent diffuses from the antistatic layer into the anti-roll layer.
• the colloidal layer is gelatin, which is converted from the sol form to the gel form.
• the first gelatin layer contains a chromium (III) salt and the second hardening layer applied thereon contains formaldehyde as hardening agent.
• Each hardening agent known hitherto has one or the other disadvantage and does not have the wide range of possible uses, as is particularly desirable in the case of auxiliary gelatin layers which are applied to a support prior to emulsionation and are later in contact with the actual photographic layers.
• the main disadvantage is that the reaction of most hardening agents with gelatin is too slow and further processing of the coated material is often only possible after days or weeks of intermediate storage.
• Chromium (III) salts are known to also show this time-dependent post-hardening. (Journal for Scientific Photography, Vol. 57, 1963, Issue 9-12, page 155 paragraph 2 and DOS 24 17 779, page 45 paragraph 3).
• This task also has DOS 2417779, in which the general problem and the solution in the form of two layers to be applied one after the other, the first a gelatin layer and the second a hardening layer, combined with polysaccharides.
• Organic compounds are applied in the top coat as curing agents, but are incompatible with polyvinyl alcohol, as described on page 55 of the DOS.
• the swelling factor is measured after 10 minutes of treatment of a test strip in distilled water at 22 ° C. It is defined According to Examples 1 and 2 of DOS 24 17 779, the layer weight (dry) consists of approximately 60% by weight of gelatin which has been hardened.
• the lowest swelling factors in DOS are 3.0; based on gelatin this means a water absorption of 5g / 1g gelatin.
• Gelatin solutions are usually applied warm to the substrate and then pass through a solidification zone in which they convert from the sol form to the gel form. The layers are only dried after this conversion. (Ullmann's Encyclopedia of Technical Chemistry, 4th Edition, Volume 18, page 443). This conversion of the gelatin from the sol form to the gel form is an essential step. For example, gelatin solutions can only be hardened with chromium (III) salts if they can react in the gel state. Gelatinesols do not cross-link with chromium (III) salts. (Photographic Science And Engineering, Volume 3, No. 6, Nov.-Dec. 1959, page 277ff).
• the solidification zone described is state of the art.
• the conversion of the sol form to the gel form generally takes over 2 minutes. claim, where temperatures below 30 ° C are necessary. This inevitably requires slow coating machine speeds or long solidification zones.
• the water absorption of the gelatin layers from DOS 2417779 is certainly chosen correctly for emulsion layers, but too high for anti-roll layers applied on the back.
• the swelling capacity required for the trouble-free passage through the development baths is maintained, the water absorption capacity of the anti-roll layer should be as low as possible.
• Another object of this invention is to dispense with a solidification zone in the coating system for economic reasons and to harden the gelatin solution from the sol form, the time-dependent post-hardening known from chromium (III) salts being avoided.
• the immediate drying of the first coating means that drying begins immediately after the layer has been applied, without the conversion of the sol form of the gelatin into the gel form being carried out.
• the first coating consists of a gelatin solution which contains hardening agents in the amount and type that can be processed immediately after drying e.g. makes possible in tandem, but is not sufficient for the proper functioning of an anti-roll layer, as described above.
• the first coating Since the application of the second coating preferably takes place immediately after the drying of the first coating, the first coating must have a strength and surface hardness immediately after it has dried, which allows the second coating to be applied and metered.
• glyoxal has an accelerating effect on hardening with chromium (III) salts, so that in a special form of the process according to the invention the hardener combination for the first coating of chromium (III) salt and glyoxal in a ratio of 1: 3 up to 3: 1.
• the gelatin is pre-hardened so quickly that the second coating solution can be applied without problems in tandem coating systems immediately after the drying of the first coating solution.
• the sequence of process steps according to the invention makes it possible to harden the surface of anti-roll layers that come into contact with the photographic treatment baths in such a way that water absorption of ⁇ 2.5 g water / 1 g gelatin is achieved. At the same time, the depth of the hardened gelatin layer remains so elastic that there are no embrittlement cracks and the flatness of the entire carrier material is preserved.
• the elasticity of the anti-roll layer can be increased further by adding plasticizers such as glycerin, glycols, sorbitol, montmorillonite and the like to the first coating.
• Additional hardening agents for the first coating can be all substances corresponding to the state of the art and suitable for photographic processes, provided that these are dosed in combination with chromium (III) salt or chromium (III) salt and glyoxal in such a way that the overall system is quick and intense reacted enough.
• a preferred form of the chromium (III) salts is chromium alum, KCr (SO4) 2 ⁇ 12 H2O.
• the second coating solution contains chromium (III) salts, with chromium alum being preferred.
• concentration of this solution of chromium (III) salt is preferably between about 0.5% by weight and about 5% by weight and depends on the applied layer thickness, which is predetermined by the mechanical equipment and by the rheology of the solution and the type of chromium salt.
• the total chromium (III) ion content of the anti-roll layer should be higher than 20 mg Cr / m 2, with more than half of the amount being applied by the second coating. Contrary to the representation from DOS 24 17 779, page 55, it is possible and even particularly advantageous if polyvinyl alcohol is added to this hardener solution. The addition of a fully saponified polyvinyl alcohol improves the rheological behavior of the hardener solution, the layer thickness can be adjusted better, the wetting is flawless and an exact straight edge run of the wet application is possible.
• Usual auxiliaries as are known in anti-roll layers on the back of layer supports for light-sensitive materials, can also be contained in the anti-roll layer according to the invention, wherein they are preferably added to the first coating solution.
• a base consisting of 175 g / m2 paper and a layer of 35 g / m2 polyethylene per side was coated with a first coating of the following composition: Water 84.75% by weight Gelatin 12% by weight Sodium nitrate 1% by weight Silica 1% by weight Glycerin 1% by weight Wetting agent 0.1% by weight Citric acid 0.02% by weight Chrome alum 0.1% by weight Triacryloylhexahydrotriazine sodium hydroxide solution up to pH 6.6 0.03% by weight
• This first coating applied to the back was dried in a hot air duct, the application weight was 6.0 g / m 2.
• the machine speed for both jobs was 100 m / min.
• the layer support from Example 1 was used.
• the composition of the recipe for the first coating was changed as follows: Basic recipe gelatin 12% by weight Sodium nitrate 1% by weight Silica 3% by weight glycerin 1% by weight Wetting agent 0.1% by weight citric acid 0.02% by weight Other additives in% by weight: Chrome alum Chromium (III) chloride 6-hydrate Triacrylhexahydrotriazine formaldehyde Glyoxal a 0.09 - - - 0.09 b 0.045 - - - 0.045 c 0.045 - - - 0.135 d 0.135 - - - 0.045 e - 0.09 - - 0.09 f 0.045 - 0.03 - - G - - - 0.045 0.09 100% by weight of Nasser added.
• the first coating applied to the back was dried in a hot air duct, the application weight was 8.5 g / m 2.
• a solution according to recipe 1b was applied to this first coating immediately after it had dried as the second coating and dried in the hot air duct.
• the application weight was a constant 250 mg / m2.
• the machine speed for both jobs was 100 m / min.
• the water absorption based on the amount of gelatin in the anti-roll layer, was determined by gravimetric evaluation after 10 minutes of treatment of a test strip in distilled water at 22 ° C. with subsequent drying Examples Water absorption right away after 4 weeks 1a 3.9 1) 3.3 1) 1b 1.8 1.7 1c 0.9 1.0 1d 0.9 1.0 1e, comparison 2.9 2.6 1f, comparison 3.6 2.8 1g, comparison 2.8 2.3 1h, comparison 3.1 2.6 Comparison of literature example from DOS 2417779 5.0 1) The reason for the relatively high values is the insufficient amount of chromium (III) ions in the second coating.
• the second coating could be applied smoothly to the first coating using a roller and air brush.
• doctor strips appeared. Examples Water absorption right away after 4 weeks 2a 0.8 0.8 2 B 2.3 2.4 2c 2.1 2.0 2d 0.6 0.6 2e 0.5 0.6 2f 2.4 2.3 2g, comparison 3.0 2.6
• the second coating could be applied without problems using a roller and air brush.
• Examples 2f and 2g were difficult to produce.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Paints Or Removers (AREA)
• Laminated Bodies (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Photoreceptors In Electrophotography (AREA)
• Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)
• Packaging Of Machine Parts And Wound Products (AREA)
• Printing Plates And Materials Therefor (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (3)

Family

ID=6330718

Family Applications (1)

Country Status (9)

Families Citing this family (7)

Citations (1)

Family Cites Families (7)

• 1987
  • 1987-07-02 DE DE19873721808 patent/DE3721808A1/de active Granted
• 1988
  • 1988-04-26 ES ES198888106625T patent/ES2028166T3/es not_active Expired - Lifetime
  • 1988-04-26 AT AT88106625T patent/ATE71746T1/de not_active IP Right Cessation
  • 1988-04-26 EP EP88106625A patent/EP0297240B1/de not_active Expired - Lifetime
  • 1988-04-26 DE DE8888106625T patent/DE3867729D1/de not_active Expired - Lifetime
  • 1988-06-28 JP JP63158239A patent/JP2710629B2/ja not_active Expired - Lifetime
  • 1988-06-30 AU AU18597/88A patent/AU609495B2/en not_active Ceased
  • 1988-06-30 CN CN88104001A patent/CN1029803C/zh not_active Expired - Fee Related
  • 1988-06-30 US US07/213,911 patent/US4977065A/en not_active Expired - Fee Related
• 1992
  • 1992-01-30 GR GR920400134T patent/GR3003701T3/el unknown

Patent Citations (1)

Also Published As

Similar Documents

Legal Events