Patents by Inventor Sundaram Krishnamurthy
Sundaram Krishnamurthy 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).
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Patent number: 5695921Abstract: A silver halide photographic element comprising a magenta dye forming coupler and a compound of formula (A) associated with the coupler: ##STR1## wherein: each R.sup.20 independently represents an alkyl, alkenyl, or heteroaryl group;Ar represents an aryl or heteroaryl group. Photographic elements of the present invention exhibit low thermal pinking, while still having good image stability and hue.Type: GrantFiled: April 4, 1996Date of Patent: December 9, 1997Assignee: Eastman Kodak CompanyInventors: Sundaram Krishnamurthy, Paul Patrick Spara, Rakesh Jain
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Patent number: 5677118Abstract: The invention provides a photographic element comprising a support bearing at least one silver halide emulsion layer having associated therewith a 5-pyrazolone photographic coupler represented by the formula (I): ##STR1## wherein a) substituents G.sup.1, G.sup.2 and G.sup.3 are individually selected from the group consisting of hydrogen, halogen, alkyl, alkoxy, aryloxy, acylamino, alkylthio, arylthio, sulfonamido, sulfamoyl, sulfamido, carbamoyl, diacylamino, alkoxycarbonyl, aryloxycarbonyl, alkoxysulfonyl, aryloxysulfonyl, alkylsulfonyl, alkylsulfoxyl, arylsulfoxyl, arylsulfonyl, alkoxycarbonylamino, aryloxycarbonylamino, alkylureido, arylureido, acyloxy, nitro, cyano, and carboxy groups;b) a and b are individually integers from 0 to 5, provided that the sum of the sigma values for G.sup.1 and G.sup.2 is at least 1.3; and c is an integer from 0 to 4;c) Z is a group of the formula (II): ##STR2## wherein R.sup.Type: GrantFiled: May 10, 1996Date of Patent: October 14, 1997Assignee: Eastman Kodak CompanyInventors: Paul Patrick Spara, Sundaram Krishnamurthy, Stanley Wray Cowan, Ruthann M. McGarry
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Patent number: 5627017Abstract: Low melting point epoxy scavenger compounds are disclosed which contain a pH dependent ionizable group to facilitate migration of the scavenger from an adjacent scavenger layer (that does not contain any coupler) to an imaging layer (containing coupler and emulsion) of a photographic element at the pH of development. One aspect of the invention comprises a process of forming an aqueous dispersion of an epoxy compound of the structural formula SI: ##STR1## wherein: R is H, an alkyl group, or an aryl group; L.sub.1 is an alkyl group or an aryl group; L.sub.2 is --O--, --CO--, --S--, --SO.sub.2 --, --PO.sub.2 --, --CO.sub.2 --, --NHCO-- or --NHSO.sub.2 --, wherein L.sub.2 may be orientated in either direction; L.sub.3 is an alkyl group; m is 0 or 1; p is 0 or 1; and X is ##STR2## wherein R' is H or an alkyl or aryl group, with the proviso that where L.sub.2 comprises an ionizable group, X may also be an alkyl group or an aryl group; wherein the compound has a melting point of less than about 50.degree. C.Type: GrantFiled: April 25, 1995Date of Patent: May 6, 1997Assignee: Eastman Kodak CompanyInventors: Krishnan Chari, Paul P. Spara, Sundaram Krishnamurthy
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Patent number: 5605787Abstract: Magenta image-dye couplers provide photographic elements and processes having superior photographic properties. The couplers are 3-anilino pyrazolone couplers having an aryl thio coupling-off group. The substituents of the coupler are specified to obtain advantageous properties.Type: GrantFiled: March 8, 1995Date of Patent: February 25, 1997Assignee: Eastman Kodak CompanyInventors: John L. Pawlak, David S. Bailey, William R. Schleigh, Charles E. Romano, Jr., Paul B. Merkel, Sundaram Krishnamurthy
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Patent number: 5571926Abstract: In the production of 1H-pyrazolo[1,5-b] [1,2,4]triazole couplers, substituted 3-amino-pyrazole compounds add to suitable organic nitriles in the presence of an acidic condensing agent such as aluminum chloride, stannic chloride or boron trifluoride to directly produce desired amidine intermediates in good yields, avoiding the generation of moisture sensitive intermediate imidate esters. Moreover, the availability of oxidation techniques to convert amidines to 1H-pyrazolo[1,5-b] [1,2,4]triazole couplers in a single step makes it possible to produce these couplers in a total of two steps compared to conventional multi-step synthetic schemes.Type: GrantFiled: October 2, 1995Date of Patent: November 5, 1996Assignee: Eastman Kodak CompanyInventor: Sundaram Krishnamurthy
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Patent number: 5543276Abstract: Thermal and photochemical yellowing of a color photographic element, such as a color print, is inhibited by incorporating into the photographic element an ionizable epoxy compound having the formula: ##STR1## wherein: R is H, alkyl, substituted alkyl, aryl, or substituted aryl;L.sub.1 is alkyl, substituted alkyl, aryl, or substituted aryl;L.sub.2 is O, CO, S, SO.sub.2, PO.sub.2, C(O)O, NHCO or NHSO.sub.2 ;L.sub.3 is alkyl or substituted alkyl;m is 0 or 1;p is 0 or 1;X is selected from the group consisting of ##STR2## wherein: R' is H, alkyl, substituted alkyl, aryl or substituted aryl,or, if L.sub.2 comprises an ionizable group, X is alkyl, substituted alkyl, aryl or substituted aryl.Type: GrantFiled: June 8, 1994Date of Patent: August 6, 1996Assignee: Eastman Kodak CompanyInventors: Krishnan Chari, Wendell F. Smith, Jr., Paul P. Spara, Sundaram Krishnamurthy
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Patent number: 5508147Abstract: Yellowing of a processed photographic element is inhibited by incorporating a scavenger comound capable of reacting with magenta coupler, e.g. an epoxy compound, in a layer adjacent a layer containing the magenta coupler. In a preferred embodiment, the magenta coupler containing layer is sandwiched between layers containing the scavenger compound. Prior to processing at least one of these layers contains a solubilizing agent for the scavenger compound. In preferred embodiments, the processing solution used to process the photographic element containing an external solubilizing agent for the scavenger compound, preferably benzyl alcohol.Type: GrantFiled: January 4, 1993Date of Patent: April 16, 1996Assignee: Eastman Kodak CompanyInventors: Krishnan Chari, Wendell F. Smith, Sundaram Krishnamurthy
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Patent number: 5476756Abstract: Yellowing of a processed photographic element is inhibited by incorporating a scavenger compound capable of reacting with magenta coupler, e.g. an epoxy compound, in a layer adjacent a layer containing the magenta coupler. At least one of these layers contains a solubilizing agent for the scavenger compound. In preferred embodiments, the processing solution used to process the photographic element contains an external solubilizing agent for the scavenger compound, preferably benzyl alcohol.Type: GrantFiled: June 8, 1994Date of Patent: December 19, 1995Assignee: Eastman Kodak CompanyInventors: Krishnan Chari, Wendell F. Smith, Sundaram Krishnamurthy
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Patent number: 5447830Abstract: Magenta image-dye couplers provide photographic elements and processes having superior photographic properties. The couplers are 3-anilino pyrazolone couplers having an aryl thio coupling-off group. The substituents of the coupler are specified to obtain advantageous properties.Type: GrantFiled: June 25, 1993Date of Patent: September 5, 1995Assignee: Eastman Kodak CompanyInventors: John L. Pawlak, David S. Bailey, William R. Schleigh, Charles E. Romano, Paul B. Merkel, Sundaram Krishnamurthy
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Patent number: 5434040Abstract: A photographic element having at least one photosensitive silver halide layer and associated therewith both a particular type of color coupler and a particular type of stabilizer. The color coupler is of the general formula (1) or (2): ##STR1## wherein A and B represent the same or different electron-withdrawing group,X is H or a group which splits off on coupling with oxidized color developer,R is an alkyl, cycloalkyl, aryl or heterocyclic which may be substituted, --COR.sup.1, --CSR.sup.1, SOR.sup.1, SO.sub.2 R.sup.1, --NHCOR.sup.1, --CONHR.sup.1, --COOR.sup.1, --COSR.sup.1, --NHSO.sub.2 R.sup.1 wherein R.sup.1 is an alkyl, cycloalkyl, or aryl group any of which are optionally substituted, and wherein two or more of A, B, R, and X optionally form part of a ring,Link is a linking group andn is 0, 1 or 2.The stabilizer is of the general formula (I) below: ##STR2## wherein: M is Cu, Co, Ni, Pd or Pt;W.sup.2, W.sup.3, W.sup.4 and W.sup.5 are defined in the specification.Type: GrantFiled: April 2, 1993Date of Patent: July 18, 1995Assignee: Eastman Kodak CompanyInventors: Rakesh Jain, Thomas H. Jozefiak, Sundaram Krishnamurthy, John L. Pawlak, Hugh M. Williamson
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Patent number: 5426021Abstract: A photographic element containing a silver halide emulsion layer having associated therewith, a dye-forming coupler and a dye stabilizer which has a melting point of less than 150.degree. C. (and preferably less than 100.degree. C.) and is of the formula: ##STR1## wherein R, m, q, X, Y, r, and (R.sup.7).sub.n are defined in the specification.The element particularly contains a coupler which forms a yellow dye upon reaction with oxidized developer. A method of making stabilizers of the above type using particular solvents and a non-aqueous workup, is also provided.Type: GrantFiled: July 2, 1993Date of Patent: June 20, 1995Inventors: Sundaram Krishnamurthy, Rakesh Jain, Paul P. Spara, Thomas A. Rosiek
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Patent number: 5399467Abstract: Novel photographic silver halide materials contain dye-forming couplers represented by formula (I): ##STR1## wherein K is a coupler moiety based on pyrazolone, phenol, naphthol, enamine, or acylacetamide to which the ballast group is attached, are useful in photographic materials and processes. The containing the couplers exhibit increased coupling activity, and provide formation of dyes having improved maximum magenta image dye density, contrast, and development speed.Type: GrantFiled: October 29, 1993Date of Patent: March 21, 1995Assignee: Eastman Kodak CompanyInventors: Sundaram Krishnamurthy, Stanley W. Cowan
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Patent number: 5378587Abstract: A photographic element contains a photographic silver halide layer having associated therewith a bicyclic pyrazolo coupler having a ballast group represented by Formula (I):--C(R').sub.m --L--Y--Ar(R").sub.nwherein:L is a divalent linking group connecting the methylene group to the remainder of the ballast group and containing at least one group selected from the group consisting of --NR.sup.1 CO--, --CONR.sup.1 --, --NR.sup.1 SO.sub.2 -- and --SO.sub.2 NR.sup.1 --, wherein R.sup.1 is hydrogen or a substituent;Y is a divalent linking group connecting L to Ar and containing a member selected from the group consisting of --O--, --S--, and --NR.sup.1 -- wherein R.sup.1 is hydrogen or a substituent;Ar is an aryl group;each R' and R" is independently a substituent, provided that at least one R" is a substituted or unsubstituted alkyl or alkoxy group having at least 10 carbon atoms; andm and n are at least 1.Type: GrantFiled: December 18, 1992Date of Patent: January 3, 1995Assignee: Eastman Kodak CompanyInventors: Sundaram Krishnamurthy, Stanley W. Cowan
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Patent number: 5359065Abstract: An improved method of preparing an ortho-, meta- or para-silyl aromatic or heteroaromatic compound represented by the formula ##STR1## wherein X is oxygen or sulfur,R.sub.1 represents the atoms necessary to complete an unsubstituted or substituted aromatic or heteroaromatic ring, andR.sub.2, R.sub.3 and R.sub.Type: GrantFiled: December 7, 1992Date of Patent: October 25, 1994Assignee: Eastman Kodak CompanyInventor: Sundaram Krishnamurthy
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Patent number: 5318884Abstract: Photographic silver halide materials and processes employ at least one coupler having a coupling-off group which includes a carbocyclic or heterocyclic ring which bears a silyl substituent on at least one of its ring carbon atoms and is attached via another of its ring atoms either directly or through a linking group or atom to the coupling position of the coupler. The silyl substituent bears three groups which are independently aromatic groups, heterocyclic groups, aliphatic groups or additional silyl groups bonded through a linking atom to the silicon atom in said silyl substituent.Type: GrantFiled: December 7, 1992Date of Patent: June 7, 1994Assignee: Eastman Kodak CompanyInventor: Sundaram Krishnamurthy
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Patent number: 5306604Abstract: Photographic silver halide materials are disclosed comprising a support and a silver halide emulsion layer having associated therewith a coupler having in a non-coupling position a silyl substituent represented by the formula: ##STR1## wherein R.sub.1 through R.sub.4 individually are unsubstituted or substituted aliphatic, aromatic or heterocyclic groups, R.sub.5 is an unsubstituted or substituted aliphatic, aromatic or heterocyclic group which can be bonded to a non-coupling position of a second coupler moiety, and n=0, 1 or 2. In a preferred embodiment, the coupler is a photographic image dye-forming coupler. Processes for developing images in the photographic materials are also disclosed.Type: GrantFiled: December 7, 1992Date of Patent: April 26, 1994Assignee: Eastman Kodak CompanyInventor: Sundaram Krishnamurthy
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Patent number: 5262292Abstract: Pyrazolone magenta dye-forming couplers having a particular arylthio coupling-off group enhance the photographic properties and improve the manufacturing and handling characteristics of materials and processes employing such couplers. The coupler contains an N-phenyl group, a 3-anilino group and a 4-(arylthio) coupling off group containing a particular aryloxymethylacylamino group as an ortho substituent. A broad range of improvements are realized including stability, reactivity, hue, and dye density in addition to simplified and safer manufacture.Type: GrantFiled: April 23, 1992Date of Patent: November 16, 1993Assignee: Eastman Kodak CompanyInventors: Sundaram Krishnamurthy, Thomas A. Rosiek, Vincent J. Flow, David S. Bailey, David J. Giacherio, John L. Pawlak, Stephen P. Singer
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Patent number: 5250400Abstract: Novel pyrazolotriazole couplers containing a ballast group of formula (I): ##STR1## are useful in photographic materials and processes. The couplers exhibit increased coupling activity, and provide formation of dyes having improved maximum magenta image dye density, contrast, and development speed when employed in color photographic materials and processes.Type: GrantFiled: February 26, 1992Date of Patent: October 5, 1993Assignee: Eastman Kodak CompanyInventors: Sundaram Krishnamurthy, Ping-Wah Tang, Stanley W. Cowan
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Patent number: 5234805Abstract: Pyrazolotriazole couplers having a ballast-containing group of the formula (I) attached to the pyrazolotriazole ring group ##STR1## wherein: R, R.sup.2, R.sup.a and R.sup.b represent hydrogen or a substituent;L is a divalent linking group connecting the ballast containing group to the pyrazolotriazole ring;L' is a linking group connecting the --BD group to the phenylene ring;n is 0 or 1;B represents --N(R.sup.c)--SO.sub.2 --, wherein R.sup.c represents hydrogen or a substituent; andD represents substituted or unsubstituted alkyl are useful in silver halide photographic materials and processes. The couplers exhibit increased coupling efficiency, and provide formation of dyes having improved maximum magenta image dye density when employed in color photographic materials and processes.Type: GrantFiled: February 26, 1992Date of Patent: August 10, 1993Assignee: Eastman Kodak CorporationInventors: Ping-Wah Tang, Sundaram Krishnamurthy, Stanley W. Cowan
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Patent number: 4853319Abstract: Novel pyrazolone photographic couplers contain in the coupling position a coupling-off group represented by the formula: ##STR1## wherein: L.sub.1 and L.sub.2 individually are unsubstituted or substituted methylene or ethylene;m and n individually are 0 or 1;Y is R.sub.1 or ZR.sub.2 ;R.sub.1 is an unsubstituted or substituted aryl or heterocyclic group, or is a secondary or tertiary carbon group represented by ##STR2## wherein R.sub.3 and R.sub.4 are selected from the group consisting of halogen, R.sub.2 and Z.sub.1 R.sub.b ; wherein Z is O, S, or NR.sub.a ; Z.sub.1 is O, S, or NR.sub.c ; and R.sub.2 is an unsubstituted or substituted alkyl, aryl, or heterocyclic group. R.sub.5, R.sub.6, R.sub.a, R.sub.b and R.sub.c are as defined in the specification. R.sub.3 optionally joins together with at least one of R.sub.4 and R.sub.Type: GrantFiled: December 14, 1987Date of Patent: August 1, 1989Assignee: Eastman Kodak CompanyInventors: Sundaram Krishnamurthy, Brian H. Johnston, Kenneth N. Kilminster, David C. Vogel, Paul R. Buckland