Patents Assigned to VEB Filmfabrik Wolfen
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Patent number: 4419431Abstract: This invention relates to a one- or two-component diazo-type material with improved light stability and duplication capabilities. This is accomplished by using compounds of the general formula ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 being the same or different, represent hydrogen, alkyl with 1 to 5 carbon atoms, R.sub.1 and R.sub.2 and/or R.sub.3 and R.sub.4 represent the alkyl groups necessary for completion of a 5- or 6-membered heterocyclic ring, wherein the ring may comprise a further hetero atom, such as N, O or S;R.sub.5, R.sub.6 being the same or different, represent hydrogen, aryl, alkyl with 1 to 4 carbon atoms;Y represents --S--, --SO--, --SO.sub.2 --; andn is 0, 1, 2, 3,which are added to the material as fading inhibitors. These compounds can be easily synthesized and are compatible with the system, having an absorption maximum below 380 nm and reduced fogging tendency. They may also be employed in the form of their hydro salts.Type: GrantFiled: November 30, 1981Date of Patent: December 6, 1983Assignee: VEB Filmfabrik WolfenInventors: Regina Lischewski, Jorg Marx, Reinhard Walter, Peter Mockel
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Patent number: 4419440Abstract: The present invention relates to a process for the introduction of water-insoluble photographic additives, especially dye couplers, in aqueous media with the application of high-boiling organic solvents. The purpose of the invention is to develop an improved process for the introduction of hydrophobic photographic additives, especially dye couplers, in gelatin or other hydrophilic bonding agents in order to produce stable dispersions suitable for storage. This invention has the object of creating a new, high-boiling solvent for the dispersion of hydrophobic photographic additives. According to the invention, this aim is achieved by employing phosphonic acid diamides, methane bisphosphonic acid diamides, phosphonic acid esters, methane bisphosphonic acid esters or mixed phosphonic acid esters or methane bisphosphonic acid ester amides as high-boiling solvents.Type: GrantFiled: November 9, 1981Date of Patent: December 6, 1983Assignee: VEB Filmfabrik WolfenInventors: Lothar Kuhnert, Burkhard Costisella, Christoph Roth, Walter Kroha, Wolfgang Baumbach, Renate Hoppe
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Patent number: 4410624Abstract: The invention relates to a process of dispersing oil-soluble photographic additives having a silver-halide base for information recording materials.According to the invention, compounds of the following general formula: ##STR1## are used as auxiliary dispersing agents. The symbolsR represents hydrogen, alkyl with 1 to 8 C atoms,M represents hydrogen, alkali metal, ammonium, andX represents OR or SO.sub.3 M.Type: GrantFiled: March 26, 1982Date of Patent: October 18, 1983Assignee: VEB Filmfabrik WolfenInventors: Dieter Plaschnick, Christoph Roth, Bernd Noll, Walter Kroha, Lothar Kuhnert
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Patent number: 4400458Abstract: It is the purpose and object of the present invention to make better use of the emission range of light sources and to create the diazonium salts necessary for such purpose. The diazonium salts of the present invention of the general formula ##STR1## wherein Y is ##STR2## R.sub.1, R.sub.2 are equal or different and are, alkyl having 1 to 10 carbon atoms, aryl having 6 to 10 carbon atoms in a mono or polycylic ring;R.sub.3 is hydrogen, halogen, alkyl, alkoxy, cyano;R.sub.4 is hydrogen, halogen, alkyl, alkoxy; andX.sup.e is an anion,can be employed with all known couplers and additives in diazotype materials. They have an absorption range of 480 to 550 nm.Type: GrantFiled: September 14, 1981Date of Patent: August 23, 1983Assignee: VEB Filmfabrik WolfenInventors: Fred Walkow, Peter Czerney, Horst Hartmann, Jorg Marx
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Patent number: 4387159Abstract: A light-sensitive, color photographic silver halide multilayer material contains for the improvement of definition, grain and color rendition DIR-couplers which are substituted in coupling position by mercapto-azole-, mercaptobenz-azole- or mercapto-azine moieties, which themselves carry hydrophilic substituents. The DIR-couplers according to the invention may be used together with other couplers and additives or as sole color forming element and are noteworthy for their high color yields, inter- and intra-image effects. They may be added as well in hydrophobic state (in dispersed form) as in hydrophilic state (as alkaline solutions) and they may be used in single layers or as associated layers with a maximum three layers of a color forming unit and the layers may be arranged in any desired order within the whole combination of layers.Type: GrantFiled: May 8, 1981Date of Patent: June 7, 1983Assignee: VEB Filmfabrik WolfenInventors: Horst Engelmann, Rainer Redmann, Monika Bethke, Christa Melz, Gerd West, Jurgen Mistol, Udo Sydow
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Patent number: 4360587Abstract: This invention relates to a radiation-sensitive, silver-free recording material for direct optical recording with high sensitivity, characterized by its exceptional resistance to light and heat and large solubility. This is achieved by the fact that the recording material contains as coloring substances, azo dyestuffs of the general formula ##STR1## R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 are the same or different and are halogen, alkoxy, alkyl, acetyl, amino; R.sub.8 hydroxy, alkoxy or acetylamino. The material distinguishes itself by the different processing variations that are possible so that with a same basic type, it is possible to obtain pictures operating according to a positive principle as well as according to a negative principle.Type: GrantFiled: August 10, 1981Date of Patent: November 23, 1982Assignee: VEB Filmfabrik WolfenInventors: Carmen Haessner geb. Michael, Heinz Mustroph, Jorg Marx
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Patent number: 4312941Abstract: The present invention is directed to a photographic material based upon silver halide emulsions comprising an emulsion layer containing a diffusible dye, and an antihalation layer containing a mordant for fixing the diffusible dye superimposed directly over the emulsion layer, the antihalation layer having its maximum degree of absorption in the same spectal range as the maximum degree of sensitivity of the emulsion layer.Type: GrantFiled: May 29, 1980Date of Patent: January 26, 1982Assignee: VEB Filmfabrik WolfenInventors: Martin Scharf, Ulrich Meisel
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Patent number: 4286054Abstract: A light-sensitive, color photographic silver halide multilayer material contains for the improvement of definition, grain and color rendition DIR-couplers which are substituted in coupling position by mercapto-azole-, mercaptobenz-azole- or mercapto-azine moieties, which themselves carry hydrophilic substituents. The DIR-couplers according to the invention may be used together with other couplers and additives or as sole color forming element and are noteworthy for their high color yields, inter- and intra-image effects. They may be added as well in hydrophobic state (in dispersed form) as in hydrophilic state (as alkaline solutions) and they may be used in single layers or as associated layers with a maximum three layers of a color forming unit and the layers may be arranged in any desired order within the whole combination of layers.Type: GrantFiled: May 29, 1980Date of Patent: August 25, 1981Assignee: VEB Filmfabrik WolfenInventors: Horst Englemann, Rainer Redmann, Monika Bethke, Christa Melz, Gerd West, Jurgen Mistol, Udo Sydow
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Patent number: 4131470Abstract: A process for the stabilization of and the prevention or substantial reduction of fogging in the use of photographic silver halide emulsions, characterized in that compounds selected from the group consisting of those represented by the general formulas I, II, and III: ##STR1## are added to the emulsion, before or during chemical sensitization and before coating of the emulsions onto a support therefor, wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are as herein described.Type: GrantFiled: December 21, 1976Date of Patent: December 26, 1978Assignee: VEB Filmfabrik WolfenInventors: Gunther Fischer, Beate Wenzel, Steffen Scheithauer, Udo Franz, Karl-Wilhelm Junge, Christof Schroter, Siegfried Gahler, Johannes Morgenstern
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Patent number: 4120726Abstract: An improved photographic silver-halide emulsion containing a sensitizer additive which is an asymmetrical disulfide of the formula(W).sub.a (X).sub.b A--S--S--B(Y).sub.c (Z).sub.dwherein:A and B are each aryl, alkyl or aralkyl radicals,X and Y are each carboxyl or alkoxycarbonyl groups,W and Z are each amino groups which may be alkylated or acylated,a, b, c, d are each 0 to 3 anda + d .gtoreq. 1 and b + c .gtoreq. 1.Type: GrantFiled: August 12, 1977Date of Patent: October 17, 1978Assignee: VEB Filmfabrik WolfenInventors: Gerhard Hanisch, Gunther Fischer, Seigfried Gahler, Udo Franz, Karl Kuschel, Roland Mayer, Gunther Bach, Karl-Wilhelm Junge
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Patent number: 4030928Abstract: Method for increasing the sensitivity of a photographic silver halide-gelatin emulsion comprising at the beginning of the chemical ripening adding to the emulsion of a dithioester of the formula: ##STR1## in which R is alkyl, .alpha.-hydroxyalkyl, .alpha.-hydroxyaralkyl, condensed aryl, or o- or p-substituted phenyl or .alpha.-naphthyl, the o- or p- located substituent being a F, OH, dialkylamino, sulfo, phenyl, phenylazo or anilidocarbonyl group and R.sub.1 is alkyl or aralkyl.Type: GrantFiled: November 18, 1975Date of Patent: June 21, 1977Assignee: VEB Filmfabrik Wolfen-Fotochemisches KombinatInventors: Siegfried Gahler, Karl-Wilhelm Junge, Gunther Fischer, Steffen Scheithauer, Horst Viola
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Patent number: 3998688Abstract: A process for the preparation of cellulose fibers from cellulose containing chips wherein the cellulose containing chips are subjected to a chemical process for the purpose of separating the cellulose from lignin and other extraneous chemicals which prior to digestion of the chips subjecting the chips to a two-step pre-treatment by:1. contacting said chips with an aqueous solution of an alkali metal, alkaline earth metal or ammonium sulfite or bi-sulfite metal; and,2. thereafter radiating the so pre-treated chips by contacting them with charged particles.Type: GrantFiled: September 4, 1974Date of Patent: December 21, 1976Assignee: VEB Filmfabrik Wolfen-Fotochemisches KombinatInventors: Klaus Fischer, Josef Ringel