Patents by Inventor Philip T. S. Lau

Philip T. S. Lau 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: 5342943
    Abstract: Process for the formation of 1-H-pyrazolo[3,2-C]-1,2-4-triazoles useful in photographic chemistry as magenta couplers. The products have chlorine or bromine available at the coupling site, and the following formula: ##STR1## wherein X is chlorine or bromine, n is 0 to 6, and each R is an organic group as defined herein. The compounds are made from a hydrazone by reacting it ##STR2## with chlorine or bromine and a base. When the base is a substance such as sodium acetate, the reaction is conducted in one step. When the base is an amine such as a tertiary amine, reaction of (I) is conducted sequentially. Thus, in this second embodiment, (I) is first reacted with chlorine or bromine, and the reaction product thereby produced is treated with the tertiary amine.
    Type: Grant
    Filed: March 3, 1993
    Date of Patent: August 30, 1994
    Assignee: Eastman Kodak Company
    Inventors: Philip T. S. Lau, Ping-Wah Tang
  • Patent number: 5340708
    Abstract: Dye-forming couplers provided by the invention are tris coupler compounds, each comprising three coupling moieties bonded to a phosphorous-containing tris linking group represented by ##STR1## has the structure (I): ##STR2## wherein each --R-- is independently a substituted or unsubstituted alkylene, alkoxylene, arylene, or aryloxylene group. Dyes of the invention are the dyes that are formed by coupling reaction of an oxidized photographic color developing agent and the new tris couplers of the invention. Photographic elements of the invention each comprise a support having thereon a photographic silver halide emulsion layer and one or more of the new tris couplers of the invention.
    Type: Grant
    Filed: December 17, 1993
    Date of Patent: August 23, 1994
    Assignee: Eastman Kodak Company
    Inventors: Ping-Wah Tang, Philip T. S. Lau, Stanley W. Cowan
  • Patent number: 5262284
    Abstract: A photographic element including a support bearing a silver halide photographic emulsion and an image dye-forming coupler, wherein the image dye-forming coupler includes a ballasted arylidene pyrazolone which is also a filter dye that upon exposure and processing of the element is destroyed in both exposed and unexposed areas of said element or a masking coupler that upon exposure and processing is destroyed only in exposed areas of the element. The arylidene pyrazolone compound includes an oxygen-inclusive electron donating group in conjugation with the arylidene function, preferably positioned para to the arylidene function.
    Type: Grant
    Filed: July 15, 1991
    Date of Patent: November 16, 1993
    Assignee: Eastman Kodak Company
    Inventors: Philip T. S. Lau, Danny R. Thompson, Stephen P. Singer
  • Patent number: 5237030
    Abstract: Photographic elements are described containing a polymeric dye-forming coupler that has been formed by emulsion polymerization of ethylenically unsaturated monomers in the presence of a high-boiling organic coupler solvent. Couplers of high activity are obtained.
    Type: Grant
    Filed: March 2, 1990
    Date of Patent: August 17, 1993
    Assignee: Eastman Kodak Company
    Inventors: Ping-Wah Tang, Philip T. S. Lau, Stanley W. Cowan
  • Patent number: 5141844
    Abstract: Photographic elements are described containing polymeric dye-forming couplers in which the polymer contains coupler moieties that upon reaction with oxidized color developing agent yield dyes of a least two different hues. In one embodiment a neutral dye is formed. In another embodiment a minor proportion of one coupler moiety is used to modify or current the spectral absorption characteristics of another coupler moiety.
    Type: Grant
    Filed: May 7, 1990
    Date of Patent: August 25, 1992
    Assignee: Eastman Kodak Company
    Inventor: Philip T. S. Lau
  • Patent number: 5118599
    Abstract: Novel yellow image dye-forming couplers are disclosed. The couplers comprise an active open-chain keto-methylene group, an anilide group attached to the keto-methylene group, and a cyclic ether group attached to the keto-methylene group. The cyclic ether group comprises two oxygen atoms. Either the anilide group or the cyclic ether may carry a ballast group capable of immobilizing the coupler in the layer in which it is contained. Color photographic elements incorporating the novel couplers are also disclosed.
    Type: Grant
    Filed: February 7, 1991
    Date of Patent: June 2, 1992
    Assignee: Eastman Kodak Company
    Inventors: Philip T. S. Lau, Danny R. Thompson, Frederick R. Green, III
  • Patent number: 5091291
    Abstract: A coupler having as a coupling-off group an alkyl group substituted with an electron source capable of stabilizing carbonium ion.
    Type: Grant
    Filed: October 25, 1990
    Date of Patent: February 25, 1992
    Assignee: Eastman Kodak Company
    Inventors: Philip T. S. Lau, Danny R. Thompson
  • Patent number: 5055385
    Abstract: There are described color photographic elements containing novel release compounds which rapidly release a photographically useful group, such as a development inhibitor, from a timing group.
    Type: Grant
    Filed: March 15, 1991
    Date of Patent: October 8, 1991
    Assignee: Eastman Kodak Company
    Inventors: Wojciech Slusarek, John M. Buchanan, Philip T. S. Lau
  • Patent number: 5043469
    Abstract: Process for the introduction of functional or functionalizable substituents para to the amino group in 2-aminophenols and 3-aminophenols. The process proceeds in one step, with substitution occurring selectively at the position para to the amino group. Consequently, the reaction is surprisingly straightforward, with very little or no contamination by isomeric by-products. The process comprises reaction of (a) an aminophenol having an open para position to the amino function, with (b) an unhindered non-enolizable aldehyde, and (c) a thiol or sulfinic acid which acts as a nucleophile. In preferred embodiments, the process is conducted at a temperature of from about 50.degree. C. to about 100.degree. C., and in the presence of a polar solvent. The reaction is promoted by an acid having sufficient acidity to protonate the amino group of the aminophenol. Preferably, the acid promoter is a mineral acid, and it is present in an amount at least substantially equivalent to the amount of aminophenol reactant.
    Type: Grant
    Filed: April 13, 1990
    Date of Patent: August 27, 1991
    Assignee: Eastman Kodak Company
    Inventors: Philip T. S. Lau, Danny R. Thompson
  • Patent number: 5034311
    Abstract: There are described color photographic elements containing novel release compounds which rapidly release a photographically useful group, such as a development inhibitor, from a timing group.
    Type: Grant
    Filed: November 16, 1990
    Date of Patent: July 23, 1991
    Assignee: Eastman Kodak Company
    Inventors: Wojciech Slusarek, John M. Buchanan, Philip T. S. Lau, David T. Southby
  • Patent number: 4992359
    Abstract: Color photographic elements comprise a support, a silver halide emulsion layer and a polymeric dye-forming coupler comprising a polyester condensation polymer having a pendant coupler moiety in which the coupler is joined via its coupling position.
    Type: Grant
    Filed: June 4, 1990
    Date of Patent: February 12, 1991
    Assignee: Eastman Kodak Company
    Inventors: Ping-Wah Tang, Philip T. S. Lau, Stanley W. Cowan
  • Patent number: 4990436
    Abstract: Tetrahydroquinoline rings fused to a phenolic ring form novel cyan due-forming coupler compounds which produce dyes having improved resistance to ferrous ion reduction.Photographic recording materials containing such coupler compounds are also disclosed.
    Type: Grant
    Filed: January 23, 1990
    Date of Patent: February 5, 1991
    Assignee: Eastman Kodak Company
    Inventor: Philip T. S. Lau
  • Patent number: 4940812
    Abstract: Process for the introduction of functional or functionalizable substituents para to the amino group in 2-aminophenols and 3-aminophenols. The process proceeds in one step, with substitution occurring selectively at the position para to the amino group. Consequently, the reaction is surprisingly straightforward, with very little or no contamination by isomeric by-products. The process comprises reaction of (a) an aminophenol having an open para position to the amino function, with (b) an unhindered non-enolizble aldehyde, and (c) a thiol or sulfinic acid which acts as a nucleophile. In preferred embodiments, the process is conducted at a temperature of from about 50.degree. C. to about 100.degree. C., and in the presence of a polar solvent. The reaction is promoted by an acid having sufficient acidity to protonate the amino group of the aminophenol. Preferably, the acid promoter is a mineral acid, and it is present in an amount at least substantially equivalent to the amount of aminophenol reactant.
    Type: Grant
    Filed: July 17, 1989
    Date of Patent: July 10, 1990
    Assignee: Eastman Kodak Company
    Inventors: Philip T. S. Lau, Danny R. Thompson
  • Patent number: 4914005
    Abstract: The reduction of cyan image dye to a leuco compound in a color photographic element by ferrous ion contained in a bleach processing solution is inhibited by the presence in the element of a polymeric latex having recurring units that are derived from certain lower alkoxyacrylate monomers optionally copolymerized with recurring units derived from certain acrylic ionomers.
    Type: Grant
    Filed: August 11, 1989
    Date of Patent: April 3, 1990
    Assignee: Eastman Kodak Company
    Inventors: Philip T. S. Lau, Ping W. Tang, Stanley W. Cowan
  • Patent number: 4804620
    Abstract: Color photographic elements contain polymeric dye-forming couplers in which the coupler moiety is joined to the polymer backbone via a linking group containing an ether moiety. Increased dye density yield is obtained.
    Type: Grant
    Filed: September 15, 1987
    Date of Patent: February 14, 1989
    Assignee: Eastman Kodak Company
    Inventors: Ping-Wah Tang, Philip T. S. Lau, Stanley W. Cowan, Harold I. Machonkin, Tien-Teh Chen
  • Patent number: 4777120
    Abstract: A photographic masking coupler containing in the coupling position a coupling-off group that is capable of reacting with oxidized color developing agent to form a water-insoluble dye in non-image areas and a water-soluble compound in image areas of a color photographic element enables formation of a colored integral mask for color correction upon exposure and processing of the element. The masking couplers are essentially colorless in a color photographic element. Such a photographic masking coupler is advantageous in a color photographic element and process.
    Type: Grant
    Filed: May 18, 1987
    Date of Patent: October 11, 1988
    Assignee: Eastman Kodak Company
    Inventor: Philip T. S. Lau
  • Patent number: 4552834
    Abstract: The bleaching from photographic elements of silver produced by the development of silver halide having a dye adsorbed to its surface by employing as a bleaching agent a ferric complex of a polycarboxylic acid is improved by the presence of a compound of the formula: ##STR1## wherein Ar is an aromatic linking group,R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are hydroxy substituted lower alkyl groups,R.sup.5 and R.sup.6 are lower alkanediyl groups,X is a charge balancing counter ion,x and y are 0 or 1, andz is 0, 1, or 2.
    Type: Grant
    Filed: March 28, 1985
    Date of Patent: November 12, 1985
    Assignee: Eastman Kodak Company
    Inventors: Philip T. S. Lau, Gary M. Einhaus
  • Patent number: 4435495
    Abstract: Photographic reagents can be released, under alkaline conditions, from certain photographic reagent releasing compounds by means of oxidized 3-pyrazolidone developing agents. Particularly useful are acyclic and cyclic compounds in which the photographic reagent is linked, through a hetero atom, to a carbon atom which is adjacent to or in conjugation with a carbonyl group or an imino group. Upon reaction, under alkaline conditions, with an oxidized 3-pyrazolidone developing agent, the bond between the hetero atom and the carbon atom is cleaved. Photographic assemblages containing photographic reagent releasing compounds and processes of releasing photographic reagents in photographic elements and assemblages are described.
    Type: Grant
    Filed: January 22, 1982
    Date of Patent: March 6, 1984
    Assignee: Eastman Kodak Company
    Inventor: Philip T. S. Lau
  • Patent number: 4401752
    Abstract: Couplers of good reactivity contain an aryloxy coupling-off group having in an ortho position a polarizable carbonyl, sulfonyl or phosphinyl substituent group which is free of photographic dye groups and photographic reagent groups.
    Type: Grant
    Filed: November 23, 1981
    Date of Patent: August 30, 1983
    Assignee: Eastman Kodak Company
    Inventor: Philip T. S. Lau
  • Patent number: T103402
    Abstract: Couplers of good reactivity contain an aryloxy coupling-off group having in an ortho position a polarizable carbonyl, sulfonyl or phosphinyl substituent group which is free of photographic dye groups and photographic reagent groups.
    Type: Grant
    Filed: February 3, 1983
    Date of Patent: September 6, 1983
    Inventor: Philip T. S. Lau