Patents by Inventor Jean-Marie O. Dewanckele

Jean-Marie O. Dewanckele 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: 5413897
    Abstract: The present invention provides a photographic material comprising on a support (i) photosensitive silver halide particles, (ii) substantially light insensitive silver salt particles having a speed at least a factor 10 less than said photosensitive silver halide particles under the same conditions of exposure and development of said photosensitive silver halide particles and (iii) a releasing compound capable of image-wise releasing under the conditions for image-wise development of said photosensitive silver halide to silver a chemical sensitizer, said chemical sensitizer rendering said substantially light insensitive silver salt particles developable. The present invention also provides a method for making an image therewith and a method for making a lithographic printing plate.
    Type: Grant
    Filed: May 4, 1994
    Date of Patent: May 9, 1995
    Assignee: Agfa-Gevaert, N.V.
    Inventors: Ludo L. Van Rompuy, Jean-Marie O. Dewanckele, Jos A. Vaes, Marcel J. Monbaliu
  • 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: 5324622
    Abstract: The present invention provides a photographic material comprising on a support (i) photosensitive silver halide particles, (ii) substantially light insensitive silver salt particles having a speed at least a factor 10 less than said photosensitive silver halide particles under the same conditions of exposure and development of said photosensitive silver halide particles and (iii) a releasing compound capable of image-wise releasing under the conditions for image-wise development of said photosensitive silver halide to silver a chemical sensitizer, said chemical sensitizer rendering said substantially light insensitive silver salt particles developable. The present invention also provides a method for making an image therewith and a method for making a lithographic printing plate.
    Type: Grant
    Filed: July 29, 1992
    Date of Patent: June 28, 1994
    Assignee: AGFA-Gevaert, N.V.
    Inventors: Ludo L. Van Rompuy, Jean-Marie O. Dewanckele, Jos A. Vaes, Marcel J. Monbaliu
  • Patent number: 5312711
    Abstract: A negatively-chargeable dry electrostatographic developer is disclosed containing fluorinated inorganic microparticles, and toner particles comprising an acidic binder resin having an acid value between 10 and 30 mg KOH/G and not comprising (a) charge-controlling agent(s). The developers according to this invention show excellent fluidity and have improved negative chargeability. According to a preferred mode, fluorinated silica-type microparticles are added to the developer as free flowing additive in an amount of 0.1 to 5% by weight with respect to the toner, which preferably comprises an acidic carbon black.
    Type: Grant
    Filed: July 16, 1991
    Date of Patent: May 17, 1994
    Assignee: AGFA-Gevaert, N.V.
    Inventors: Serge M. Tavernier, Paul F. Sterckx, Jean-Marie O. Dewanckele
  • Patent number: 5254443
    Abstract: A photographic direct positive material is disclosed comprising a support and one or more radiation sensitive emulsion layers containing internal latent image-forming silver halide grains characterized in that at least one of said emulsion layers further contains a masked stabilizer corresponding to general formula (I): ##STR1## wherein Z represents a lower alkyl group, a nitro group or a halogen atom, n=0 to 4, and M represents a positive counterion.Preferred compounds are 1-(2-sulphonatobenzoyl)-5-methyl-benzotriazole, 1-(2-sulphonatobenzoyl)-6-methyl-benzotriazole or a mixture of both.The masked stabilizer is preferably incorporated in the emulsion layer(s). The material preferably further contains a nucleating agent. Improved direct positive sensitometric properties and wider exposure latitude before encountering rereversal are obtained.
    Type: Grant
    Filed: July 21, 1992
    Date of Patent: October 19, 1993
    Assignee: Agfa-Gevaert, N.V.
    Inventors: Piet Kok, Jean-Marie O. Dewanckele
  • Patent number: 5236815
    Abstract: A new class of photographic masked stabilizers is disclosed showing following general chemical formula (Ia) or (Ib): ##STR1## wherein X and Y each independently represent N or CR, R being hydrogen or lower alkyl,Z represents a lower alkyl group, a nitro group, a halogen atom or hydrogen, andM represents a positive counterion, preferably an alkali cation, ammonium or substituted ammonium.The compounds are demasked by hydrolysis under alkaline conditions. They can be incorporated in a developing solution or in a photographic material, preferably in the backing layer. They show an enhanced solvability in water compared to the corresponding unmasked stabilizers.A preferred compound is 1-(2-sulphonatobenzoyl)-5-nitroindazole trimethylamine, sodium or potassium salt.
    Type: Grant
    Filed: August 3, 1992
    Date of Patent: August 17, 1993
    Assignee: Agfa-Gevaert, N.V.
    Inventors: Jean-Marie O. Dewanckele, Richard A. Ooms, Marc B. Graindourze, Piet Kok
  • Patent number: 5200295
    Abstract: A method for the production of a silver image by the silver complex diffusion transfer reversal process, said method comprising the following steps:(I) image-wise photo-exposing a silver halide emulsion layer of a photographic silver halide emulsion having in waterpermeable relationship with the silver halide at least one developing agent,(II) wetting with a practically neutral aqueous liquid the said photo-exposed silver halide emulsion layer and/or wetting with said liquid a development nuclei containing layer of an image-receiving material as defined hereinafter and contacting said materials thereby bringing said layers into waterpermeable relationship with each other, and(III) separating the contacted materials after formation in the image-receiving material of a silver image,wherein said image-receiving material contains in co-operable relationship: (i) physical development nuclei, (ii) a silver halide solvent being a silver complexing agent or precursor thereof, (iii) a watersoluble sulfite or sulfite p
    Type: Grant
    Filed: December 10, 1991
    Date of Patent: April 6, 1993
    Assignee: AGFA-Gevaert N.V.
    Inventors: Leon L. Vermeulen, Robert S. Pauwels, Jean-Marie O. Dewanckele
  • 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: 5198333
    Abstract: A new class of electron-accepting compounds for photographic emulsions is disclosed represented by following general formula (I): ##STR1## wherein: each of Z and Q which may be the same or different represents the atoms necessary to complete an unsubstituted or substituted nitrogen-containing heterocyclic ring;each of T.sub.1 and T.sub.2 which may be the same or different represents alkyl, cycloalkyl, alkoxy, aryl, aryloxy, halogen, cyano, hydroxy, carboxyl, sulfo, carbamoyl, acyl, acylamino, sulfamoyl, sulfonamido or a benzocondensed ring, each of which can be further substituted or not;q=1, 2 or 3, and p and r=0, 1 or 2.In this formula the nitro containing heterocyclic nucleus is preferably nitropyridine or nitrothiazole.In a preferred embodiment of the invention electron-accepting compounds are incorporated in negative or direct positive roomlight emulsions. In the latter case the emulsion layer preferably contains in addition a nitroindazole or nitrobenzimidazole derivative.
    Type: Grant
    Filed: March 13, 1991
    Date of Patent: March 30, 1993
    Assignee: Agfa-Gevaert, N.V.
    Inventors: Jean-Marie O. Dewanckele, Paul R. Callant, Marc H. Van Bockstaele, Marc B. Graindourze
  • Patent number: 5188919
    Abstract: Particulate toner material for use in the development of latent electrostatic images, wherein said particulate toner material is capable of acquiring by triboelectric contact electrification a net negative charge and contains thermoplastic resin(s) as binder in combination with a colorant and a compound capable of imparting a negative charge to the particulate toner material in contact electrification, wherein the latter compound is an anthranilic acid derivative comprising a sulfonamido-group.
    Type: Grant
    Filed: August 13, 1991
    Date of Patent: February 23, 1993
    Assignee: Agfa-Gevaert, N.V.
    Inventors: Jean-Marie O. Dewanckele, Serge M. Tavernier, Jean-Pierre A. Ghekiere
  • Patent number: 5187054
    Abstract: A photographic material is disclosed containing in a non-light sensitive layer above the emulsion layer an anti-sludging compound corresponding to following general formula (I): ##STR1## wherein Ball represents a ballast group, L represents a divalent linking group and Z represents the necessary atoms to close a heterocyclic ring with the proviso that said heterocyclic ring contains no mercapto substituent. The divalent linking group is preferably chosen from the list of --O--, --S--, --CO--NR.sub.1 --, --NR.sub.2 --NR.sub.3 --,--SO.sub.2 --NR.sub.4 --, --O--CR.sub.5 R.sub.6 --CO--NH-- wherein each of R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, and R.sub.6 represents hydrogen, alkyl or aralkyl. The heterocyclic ring is preferably chosen from the list of imidazole, benzimidazole, 1,2,3-triazole, 1,2,4-triazole, benzotriazole, tetrazole, indazole, uracil and hydantoin.The non-light sensitive layer, wherein the anti-sludging compound is added, is preferably the top protective layer.
    Type: Grant
    Filed: June 1, 1992
    Date of Patent: February 16, 1993
    Assignee: Agfa-Gevaert N.V.
    Inventors: Jean-Marie O. Dewanckele, Emiel A. Hofman
  • Patent number: 5156940
    Abstract: A new class of photographic stabilizers is prepared and their use in photographic materials is disclosed. These compounds are 1-phenyl-3-pyrazolidinone derivatives corresponding to following general formula: ##STR1## wherein: A represents a group capable of adsorbing at the surface of silver halides;L is a divalent linking group and r is 0 or 1;R1 and R2 each represent hydrogen, lower alkyl or substituted lower alkyl.The photographic materials containing the substances of the invention are preferably DTR mono-sheet elements which after processing can serve as planographic printing plates.
    Type: Grant
    Filed: February 13, 1991
    Date of Patent: October 20, 1992
    Assignee: AGFA-Gevaert, N.V.
    Inventors: Piet Kok, Jos A. Vaes, Jean-Marie O. Dewanckele, Luc J. Wabbes
  • Patent number: 5155014
    Abstract: Method for the production of direct-positive images by image-wise exposing a light-sensitive silver halide material comprising a support and an internal latent image-type silver halide emulsion layer and developing said exposed material in the presence of at least one development nucleator and density-increasing amounts of a compound chosen from the class consisting of formic acid, oxalic acid, glyoxylic acid, or salts of these and/or of a compound chosen from the class consisting of polyethylene glycols, with a hydroquinone-type developing solution having a pH not higher than 12.0 and comprising less than 25 g per liter of a hydroquinone and 5 to 100 g per liter of at least one alkanolamine.
    Type: Grant
    Filed: August 14, 1991
    Date of Patent: October 13, 1992
    Assignee: Agfa-Gevaert, N.V.
    Inventors: Jozef P. De Prijcker, Fernand I. Ketels, Jean-Marie O. Dewanckele, Piet Kok
  • Patent number: 5141843
    Abstract: A developer liquid suited for use in development of photographic silver halide emulsion layer materials which liquid contains:1) hydroquinone or a substituted hydroquinone as sole developing agent or said hydroquinone as main developing agent in combination with an auxiliary developing agent in an amount less than 10 mole % with respect to the main developing agent,2) an inorganic compound yielding free sulphite ions in an amount of at least 5 grams per liter,3) an organic anti-fogging agent corresponding to the following general formula (Z): ##STR1## wherein: X.sup.2 represents an alkyl group or an aryl group including said groups in substituted form or an amino group including said group in substituted form;the amount of anti-fogging agent being in the range of 50 mg to 1 g per liter,4) a polymer containing a plurality of alkylene oxide units, and5) the necessary alkaline material to have in said liquid a pH of at least 10.5. Optional additives can also be present in the developing liquid.
    Type: Grant
    Filed: March 27, 1991
    Date of Patent: August 25, 1992
    Assignee: AGFA-Gevaert N. V.
    Inventors: Richard A. Ooms, Piet Kok, Jean-Marie O. Dewanckele
  • Patent number: 5122434
    Abstract: A halogen acceptor according to general chemical formula (I) is added to a photographic negative roomlight emulsion, consisting of at least 90% of silver chloride, having an average grain size smaller than 0.3 micron, and internally doped with an element of group VIII of the periodic table. ##STR1## In this formula: R.sup.1 =alkyl having at least 4 C-atoms, preferably between 4 and 9.In the coated emulsion layer, the halogen acceptors of the invention provide a clear print-out effect and an improved development latitude when the emulsion layer is developed in a "hard-dot Rapid Access" processing system.In a preferred embodiment R=--C.sub.6 H.sub.13 and the element of group VIII is Rhodium.
    Type: Grant
    Filed: March 13, 1991
    Date of Patent: June 16, 1992
    Assignee: AGFA-Gevaert, N.V.
    Inventors: Marc H. Van Bockstaele, Marc B. Graindourze, Jean-Marie O. Dewanckele
  • Patent number: 5116722
    Abstract: Method of forming a silver image by exposing a silver halide emulsion spectrally sensitized with a trinuclear merocyanine dye to light of 600-690 nm and wet-processing the emulsion with aqueous developing or activating solution and fixing solution, thereby dissolving away said dye from the resulting silver-image-containing material, said trinuclear merocyanine dye comprising at least 2 water-solubilizing groups.
    Type: Grant
    Filed: November 2, 1990
    Date of Patent: May 26, 1992
    Assignee: Agfa-Gevaert, N.V.
    Inventors: Paul R. Callant, Jean-Marie O. Dewanckele
  • Patent number: 5043245
    Abstract: Process for the production of a laminated article including a sheet support bearing a silver image produced by the silver complex diffusion transfer process in a layer containing developement nuclei, wherein such supported image is heat-laminated with a protective thermoplastic resin layer of sheet that covers it. The heat-lamination of the nuclei-containing layer with the silver image therein takes place in the presence of at least one of certain heterocyclic black-toning agents which are effective to prevent degradation of the neutral black coloration and density loss of the silver image as a result of heat-lamination.
    Type: Grant
    Filed: January 25, 1990
    Date of Patent: August 27, 1991
    Assignee: AGFA Gevaert, N.V.
    Inventors: Leon L. Vermeulen, Robert S. Pauwels, Piet Kok, Jean-Marie O. Dewanckele