Patents by Inventor Siu C. Tsoi

Siu C. Tsoi 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: 6790585
    Abstract: The present invention relates to a method for developing an exposed high contrast photographic silver halide material, said photographic material comprising a support bearing at least one silver halide emulsion layer, containing at least one hydrazide nucleating agent. According to the invention, the nucleating agent has the formula (I) and the photographic material is developed in a hydroquinone-free developer, comprising a main developing agent of the ascorbic acid or ascorbic acid salt type, and as auxiliary developing agent a mixture of 3-pyrazolidones of which at least one has the formula (II): wherein at least one of the radicals R3 to R9 contains a solubilizing group. This combination enables photographic materials with ultrahigh contrast to be obtained.
    Type: Grant
    Filed: June 19, 2003
    Date of Patent: September 14, 2004
    Assignee: Eastman Kodak Company
    Inventors: Jacques Roussilhe, Siu C. Tsoi, John D. Goddard, Llewellyn J. Leyshon
  • Publication number: 20040023149
    Abstract: The present invention relates to a method for developing an exposed high contrast photographic silver halide material, said photographic material comprising a support bearing at least one silver halide emulsion layer, containing at least one hydrazide nucleating agent.
    Type: Application
    Filed: June 19, 2003
    Publication date: February 5, 2004
    Inventors: Jacques Roussilhe, Siu C. Tsoi, John D. Goddard, Llewellyn J. Leyshon
  • Patent number: 6087084
    Abstract: A class of pyrazolidone compounds suitable for use as electron transfer agents in photographic development comprises pyrazolidones substituted in the 1-position by an aromatic group that is substituted in the ortho, meta or para position by --O--CO--R, wherein R is a monovalent organic group having up to 24 carbon atoms. This ester group is hydrolyzable in an alkaline developer solution, thereby deactivating the electron transfer agents after a period of time and reducing the contamination effect of seasoning into the developer solution. Photographic recording materials can be developed in reactive association with the electron transfer agent. The electron transfer agent can be present in the photographic recording materials, or in develper solutions.
    Type: Grant
    Filed: June 24, 1999
    Date of Patent: July 11, 2000
    Assignee: Eastman Kodak Company
    Inventors: Siu C. Tsoi, Peter J. Twist
  • Patent number: 6033833
    Abstract: A new fogging photographic processing solution for a reversal process comprises a compound (I) and a bi-nucleophilic agent. Compound (I) corresponds to the following formula: ##STR1## wherein A is a group capable of being adsorbed to the silver halide surface, L is a linking group and r is 0 or 1, R.sub.1 and R.sub.2 are independently selected from an alkyl group, substituted or unsubstituted, and an aryl group substituted or unsubstituted. A process of producing a positive image by imagewise exposure of a reversal silver halide material comprises contacting the material with the above fogging solution or by imagewise exposure of such a material containing a compound (I) and contacting the material with a solution comprising a bi-nucleophilic agent.
    Type: Grant
    Filed: April 29, 1999
    Date of Patent: March 7, 2000
    Assignee: Eastman Kodak Company
    Inventors: Siu C. Tsoi, Peter J. Twist, David T. Southby
  • Patent number: 5972584
    Abstract: A class of pyrazolidone compounds suitable for use as electron transfer agents in photographic development comprises pyrazolidones substituted in the 1-position by an aromatic group that is substituted in the ortho, meta or para position by --O--CO--R, wherein R is a monovalent organic group having up to 24 carbon atoms. This ester group is hydrolyzable in an alkaline developer solution, thereby deactivating the electron transfer agents after a period of time and reducing the contamination effect of seasoning into the developer solution. Photographic recording materials can be developed in reactive association with the electron transfer agent. The electron transfer agent can be present in the photographic recording materials, or in develper solutions.
    Type: Grant
    Filed: February 23, 1999
    Date of Patent: October 26, 1999
    Assignee: Eastman Kodak Company
    Inventors: Siu C. Tsoi, Peter J. Twist
  • Patent number: 5962203
    Abstract: A new fogging photographic processing solution for a reversal process comprises a compound (I) and a bi-nucleophilic agent. Compound (I) corresponds to the following formula: ##STR1## wherein A is a group capable of being adsorbed to the silver halide surface, L is a linking group and r is 0 or 1, R.sub.1 and R.sub.2 are independently selected from an alkyl group, substituted or unsubstituted, and an aryl group substituted or unsubstituted. A process of producing a positive image by imagewise exposure of a reversal silver halide material comprises contacting the material with the above fogging solution or by imagewise exposure of such a material containing a compound (I) and contacting the material with a solution comprising a bi-nucleophilic agent.
    Type: Grant
    Filed: August 6, 1998
    Date of Patent: October 5, 1999
    Assignee: Eastman Kodak Company
    Inventors: Siu C. Tsoi, Peter J. Twist, David T. Southby
  • Patent number: 5942379
    Abstract: The present concerns compounds of the 3-pryazolidone type comprising solubilizing groups which are not directly attached to the phenyl ring or to the pyrazolidino ring. These compounds can be used as co-developing agents in the development of black and white photographic products.
    Type: Grant
    Filed: January 21, 1998
    Date of Patent: August 24, 1999
    Assignee: Eastman Kodak Company
    Inventors: Jacques Roussilhe, Siu C. Tsoi
  • Patent number: 5932399
    Abstract: A class of pyrazolidone compounds suitable for use as electron transfer agents in photographic development comprises pyrazolidones substituted in the 1-position by an aromatic group that is substituted in the ortho, meta or para position by -O-CO-R, wherein R is a monovalent organic group having up to 24 carbon atoms. This ester group is hydrolyzable in an alkaline developer solution, thereby deactivating the electron transfer agents after a period of time and reducing the contamination effect of seasoning into the developer solution. Photographic recording materials can be developed in reactive association with the electron transfer agent. The electron transfer agent can be present in the photographic recording materials, or in develper solutions.
    Type: Grant
    Filed: November 14, 1997
    Date of Patent: August 3, 1999
    Assignee: Eastman Kodak Company
    Inventors: Siu C. Tsoi, Peter J. Twist
  • Patent number: 5780212
    Abstract: The present invention concerns a developer for silver halide photographic products comprising a co-developing agent of the 1-phenyl-3-pyrazolidinone type. These co-developing agents comprise solubilizing groups which are not attached directly to the phenyl ring or the pyrazolidine ring, and improve the stability of the developer composition.
    Type: Grant
    Filed: June 24, 1997
    Date of Patent: July 14, 1998
    Assignee: Eastman Kodak Company
    Inventors: Jacques Roussilhe, Siu C. Tsoi
  • Patent number: 5554492
    Abstract: The invention provides a color photographic material comprising at least one silver halide emulsion layer having associated therewith a dye image-forming coupler and which contains in a layer thereof an ETA (electron transfer agent) releasing compound of the general formula: ##STR1## wherein R.sup.1 is an alkyl group,R.sup.2 to R.sup.6 are individually H or an alkyl group with the proviso that when one or both of R.sup.5 or R.sup.6 are H, R.sup.3 and R.sup.4 must not be H,R.sup.7 to R.sup.11 are individually H, or an alkyl or alkoxy group,A is H or an alkyl group and B is an alkyl group or, together with the atoms to which they are attached, A and B complete a carbocyclic or heterocyclic ring group,or,when A and B are not linked together, A and R.sup.2 may together complete an aromatic or nonaromatic carbocyclic group or an aromatic or nonaromatic heterocyclic group,with the proviso that if R.sup.7 to R.sup.11 are all hydrogen then neither R.sub.3 nor R.sub.4 are methyl or hydroxymethyl.
    Type: Grant
    Filed: April 7, 1995
    Date of Patent: September 10, 1996
    Assignee: Eastman Kodak Company
    Inventor: Siu C. Tsoi
  • Patent number: 5411842
    Abstract: A method for making a photographic silver halide developer composition, preferably immediately before use, by electrolysing an aqueous medium containing a developing agent precursor composition which forms or releases a silver halide developing agent at an electrode upon electrolysis.
    Type: Grant
    Filed: April 7, 1994
    Date of Patent: May 2, 1995
    Assignee: Eastman Kodak Company
    Inventors: Michael Ridgway, Nigel E. Milner, Siu C. Tsoi, Paul C. Ward
  • Patent number: 5385816
    Abstract: This invention provides a color photographic element comprising, in an adjacent silver halide emulsion layer,(1) a development inhibitor releasing developer (IRD) which comprises a hydrazide, sulphonamidophenol, sulphonamidonaphthol, or hydroquinone moiety attached directly or via a linking group to a development inhibitor moiety which compound is oxidizable during silver halide development enabling release of the development inhibitor moiety under alkaline conditions,(2) a sulphonhydrazide color developing agent, and(3) a color coupler capable of forming image dye with the sulphonhydrazide during silver halide development.
    Type: Grant
    Filed: March 11, 1993
    Date of Patent: January 31, 1995
    Assignee: Eastman Kodak Company
    Inventors: Paul L. R. Stanley, Siu C. Tsoi
  • Patent number: 4978605
    Abstract: A non-diffusible, yellow dye image-forming benzoylacetanilide coupler having an aryloxy coupling-off group where (a) the benzoyl group comprises a substituent R.sup.1 O-- wherein R.sup.1 is an alicyclic or aliphatic, unsubstituted or substituted, branched or unbranched hydrocarbon group; and, (b) at least one of the benzoyl group and acetanilide group comprise a substituent that comprises a branched alkyl group containing at least 4 carbon atoms wherein the alkyl chains are uninterrupted or interrupted by hetero atoms or groups, enables improved solubility in coupler solvents in a photographic material, and the yellow dyes resulting from such couplers upon oxidative coupling have improved light stability. Such couplers are advantageous in photographic silver halide elements and processes.
    Type: Grant
    Filed: January 6, 1989
    Date of Patent: December 18, 1990
    Assignee: Eastman Kodak Company
    Inventor: Siu C. Tsoi
  • Patent number: 4758501
    Abstract: Novel photographic acetanilide dye-forming couplers comprise a group comprising a stabilizer moiety represented by the formula: ##STR1## wherein R is halogen or alkoxy having 1 to 4 carbon atoms; R.sub.1 is hydrogen, halogen, alkyl or alkoxy; R.sub.2 and R.sub.3 are individually alkyl; and, X is a linking group. Such couplers provide advantageous stability in dyes formed from the couplers. These couplers are useful in photographic silver halide materials and processes.
    Type: Grant
    Filed: June 5, 1987
    Date of Patent: July 19, 1988
    Assignee: Eastman Kodak Company
    Inventors: Paul R. Buckland, Siu C. Tsoi