Patents by Inventor Rene M. De Keyzer

Rene M. De Keyzer has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5340690
    Abstract: According to the present invention there is provided a method for making a lithographic printing plate according to the DTR-process comprising the steps of:information-wise exposing an imaging element comprising on a support a silver halide emulsion layer and an image-receiving layer containing physical development nuclei anddeveloping said information-wise exposed imaging element with an alkaline processing liquid in the presence of developing agent(s) and silver halide solvent(s) characterized in that said silver halide solvents comprise a combination of (an) alkanolamine(s) and a thiosulfate wherein said thiosulfate is used in a total amount between 0.01% and 1% by weight in said alkaline processing liquid.
    Type: Grant
    Filed: March 15, 1993
    Date of Patent: August 23, 1994
    Assignee: Agfa-Gavaert, N.V.
    Inventors: Rene M. De Keyzer, Jean-Marie O. Dewanckele, Ludo L. Van Rompuy, Jos A. Vaes
  • Patent number: 5308738
    Abstract: The present invention provides a photographic material comprising on a support an image-receiving layer containing physical development nuclei, a photosensitive silver halide emulsion layer and a substantially light insensitive layer containing silver salt characterized in that said photosensitive silver halide emulsion layer contains silver halide particles having an average diameter of at least 0.6 .mu.m, said photosensitive silver halide emulsion layer being located between said image-receiving layer and said substantially light insensitive layer and said substantially light insensitive layer having a speed of at least a factor 10 less than said photosensitive silver halide emulsion layer. The present invention also provides a method for making an image therewith. The photographic material of the present invention is of high speed and can yield direct positive image with a low density in the non-image areas.
    Type: Grant
    Filed: June 5, 1992
    Date of Patent: May 3, 1994
    Assignee: Agfa-Gevaert, N.V.
    Inventors: Rene M. De Keyzer, Johan J. Lamotte
  • Patent number: 5200294
    Abstract: According to the present invention there is provided a method for making a lithographic printing plate according to the DTR-process comprising the steps of:information-wise exposing an imaging element comprising on a support a silver halide emulsion layer and an image-receiving layer containing physical development nuclei anddeveloping said information-wise exposed imaging element with an alkaline processing liquid in the presence of developing agent(s), silver halide solvent(s) and hydrophobizing agent(s) characterized in that said hydrophobizing agent(s) are present in said alkaline processing liquid in a total amount of at least 0.1 g/l and wherein at least one of said silver halide solvents is a compound corresponding to the following formula:Z--(R.sup.1 --S).sub.t --R.sup.2 --S--R.sup.3 --Y (I)wherein Z and Y each independently represents hydrogen, an alkyl group, an amino group, and ammonium group, a hydroxyl, a sulfo group, a carboxyl, an amino carbonyl or an aminosulfonyl, R.sup.1, R.sup.2 and R.sup.
    Type: Grant
    Filed: December 19, 1991
    Date of Patent: April 6, 1993
    Assignee: Agfa-Gevaert, N.V.
    Inventors: Rene M. De Keyzer, Jean-Marie O. Dewanckele, Ludo L. Van Rompuy, Jos A. Vaes
  • Patent number: 5162192
    Abstract: An aqueous alkaline processing liquid suitable for use in the silver complex diffusion transfer reversal (DTR-) process, wherein wherein said liquid contains a mixture of alkanolamines, the said mixture consisting of (I) N-methyl-diethanolamine and of (II) N,N-dimethyl-ethanolamine in a total amount in the range from 0.3 mol/l to 1.5 mol/l, and in a molar ratio of (I) to (II) from 1/20 to 20/1.
    Type: Grant
    Filed: September 9, 1991
    Date of Patent: November 10, 1992
    Assignee: Agfa-Gevaert, N.V.
    Inventors: Rene M. De Keyzer, Raymond L. Odeurs, Luc A. De brabandere
  • Patent number: 5124229
    Abstract: An aqueous alkaline processing liquid suitable for use in the silver complex diffusion transfer reversal (DTR-) process, wherein said liquid contains one or more alkanolamines, the said alkanolamine(s) consisting of one or more tertiary alkanolamines in an amount in the range from 0.3 mol to 1.5 mol/l, and one or more secondary alkanolamines in an amount from 0 mol % to 5 mol % with respect to the amount of tertiary alkanolamine(s), and said liquid also contains a mixture of a silver image toning agent A being 1-phenyl-1H-tetrazole-5-thiol or a tautomer thereof and at least one other silver image toning agent B being a 1-phenyl-1H-tetrazole-5-thiol or a tautomer thereof, wherein the phenyl nucleus is substituted with halogen, the toning agent A and toning agent(s) B being present in said liquid in a molar ratio from 1/15 to 15/1.
    Type: Grant
    Filed: May 17, 1990
    Date of Patent: June 23, 1992
    Assignee: AGFA-Gevaert, N.V.
    Inventors: Rene M. De Keyzer, Raymond L. Odeurs, Luc A. De Brabandere
  • Patent number: 5063136
    Abstract: An aqueous alkaline processing liquid suitable for use in the silver complex diffusion transfer (DTR-) process, wherein said liquid contains one or more alkanolamines, the said alkanolamine(s) consisting of one or more tertiary alkanolamines in an amount in the range from 0.15 mol to 1.5 mol/l, and one or more secondary alkanolamines in an amount higher than 5 mol % but not higher than 100 mol % with respect to the amount of tertiary alkanolamine(s), and said liquid also contains a mixture of a silver image toning agent A being 1-phenyl-1H-tetrazole-5-thiol or a tautomer thereof and at least one other silver image toning agent B being a 1-phenyl-1H-tetrazole-5-thiol or a tautomer thereof, wherein the phenyl nucleus is substituted with halogen, the toning agent A and toning agent(s) B being present in said liquid in a molar ratio from 1/15 to 15/1.
    Type: Grant
    Filed: May 17, 1990
    Date of Patent: November 5, 1991
    Assignee: AGFA-Gevaert, N.V.
    Inventors: Rene M. De Keyzer, Raymond L. Odeurs, Luc A. De brabandere
  • Patent number: 4859565
    Abstract: Method for making images by image-wise exposing a silver halide emulsion layer, developing it with an alkaline processing solution in the presence of a silver halide solvent, development nuclei, and a density- and tone-controlling compound, transferring silver complexes from the emulsion layer to a non-light-sensitive image-receiving layer and forming an image therein, said density- and tone-controlling compound being contained in said image-receiving layer and/or in said processing solution and corresponding to the general formula: ##STR1## wherein R.sup.1, R.sup.2, and R.sup.3 (same or different) represent hydrogen, C.sub.1 -C.sub.8 alkyl, or Alk.sub.1 --X--Alk.sub.2 --Y--; Alk.sub.1 is (substituted) C.sub.1 -C.sub.8 alkyl; X is --O-- or --S--; Alk.sub.2 is (substituted) C.sub.1 -C.sub.8 alkylene; Y is a single bond, --O--, --S--, --CONH--, --SO.sub.2 NH--, or --NHCONH--; R.sup.3 can alternatively represent (substituted) C.sub.1 -C.sub.8 alkylthio; at least one of R.sup.1, R.sup.2, and R.sup.
    Type: Grant
    Filed: April 26, 1988
    Date of Patent: August 22, 1989
    Assignee: Agfa-Gevaert, N.V.
    Inventors: Rene M. De Keyzer, Robert J. Pollet, Leon L. Vermeulen
  • Patent number: 4859566
    Abstract: Image receiving material suited for use in the silver complex diffusion transfer reversal process which material contains a water-impermeable support coated with (1) an image-receiving layer containing physical development nuclei dispersed in a waterpermeable binder and (2) a waterpermeable top layer free from development nuclei and containing a hydrophilic colloid, characterized in that:(i) the total solids coverage of said two layers (1) and (2) is at most 2 g/m2,(ii) in layer (1) the coverage of said nuclei is in the range of 0.1 mg/m2 to 10 mg/m2, and the coverage of binder is in the range of 0.4 to 1.3 g/m2, and(iii) in said top layer (2) the coverage of hydrophilic colloid is in the range of 0.1 to 0.9 g/m2.
    Type: Grant
    Filed: August 4, 1988
    Date of Patent: August 22, 1989
    Assignee: Agfa-Gevaert, N.V.
    Inventor: Rene M. De Keyzer
  • Patent number: 4720447
    Abstract: Method of making images by image-wise exposing a silver halide emulsion layer, developing it with an alkaline processing solution in the presence of a silver halide solvent and causing silver complexes to diffuse from the emulsion layer into a non-light-sensitive image-receiving layer in the presence of development nuclei thereby to form a silver transfer image in that layer, said transfer image formation occurring in the presence of at least one heterocyclic azole compound, which influences the density and tone of said transfer image, said compound being contained in said image-receiving layer and/or in said processing solution and being a heterocyclic azole corresponding to the general formula: ##STR1## wherein Y is .dbd.N-- or .dbd.HC--; Z represents atoms completing a heterocycle; A is a chemical bond or the group --(L.sup.1).sub.n --Alk--(L.sup.2).sub.m -- wherein n is 0 or 1, L.sup.
    Type: Grant
    Filed: October 9, 1986
    Date of Patent: January 19, 1988
    Assignee: AGFA-Gevaert, N.V.
    Inventors: Rene M. De Keyzer, Leon L. Vermeulen, Robert J. Pollet
  • Patent number: 4686174
    Abstract: A photographic material for the production of continuous tone silver images by the diffusion transfer reversal process using at least two independently prepared silver halide emulsions of different photo-sensitivity and having a silver halide composition as defined in the description, either in admixture in a single supported emulsion layer or coated on the same support as separate superposed emulsion layers.
    Type: Grant
    Filed: January 7, 1986
    Date of Patent: August 11, 1987
    Assignee: Agfa-Gevaert N.V.
    Inventors: Rene M. De Keyzer, Jos A. Vaes, Jules R. Berendsen
  • Patent number: 4563410
    Abstract: A method for the preparation of a planographic printing plate wherein a sheet material, which comprises an exterior hydrophilic colloid layer having concentrated on its surface a silver image formed by the silver complex diffusion transfer process with NiS or mixed crystal NiS.Ag.sub.2 S development nuclei in which the molar ratio of NiS to Ag.sub.2 S is not smaller than 1:1, is treated with a liquid for hydrophobizing the silver image for planographic printing, such liquid containing in dissolved state a heterocyclic compound corresponding to one of the following tautomeric structures (A) and (B) or (C) and (D): ##STR1## wherein: R.sup.1 represents hydrogen, amino or acylamino,R.sup.2 represents an alkyl group, andR.sup.3 represents an alkyl group, or an alkanamido-arylene group.
    Type: Grant
    Filed: August 15, 1984
    Date of Patent: January 7, 1986
    Assignee: Agfa-Gevaert N.V.
    Inventors: Antoine A. De Jaeger, Alfons J. Bertels, Albert L. Poot, Rene M. De Keyzer, Francis J. Sels