Patents Represented by Attorney Torger N. Dahl
  • Patent number: 4507377
    Abstract: A liquid electrostatic image developer is disclosed which forms self-fixing images on an electrostatic image-bearing surface which may be the image-forming surface. The developer comprises a plurality of particles composed of a compatible blend of at least one polyester resin and at least one polyester plasticizer. The plasticizer contains essentially no curable groups and is insoluble in the liquid carrier. Furthermore, images from certain preferred developers containing dispersed colorants are crack-resistant in addition to self-fixing.
    Type: Grant
    Filed: November 19, 1982
    Date of Patent: March 26, 1985
    Assignee: Eastman Kodak Company
    Inventor: Peter S. Alexandrovich
  • Patent number: 4496643
    Abstract: A two-component, dry electrostatic developer composition containing toner particles and coated-carrier particles is disclosed. The toner contains a binder polymer and a phosphonium, arsonium or stibonium charge-control agent dispersed in the toner binder. The carrier is coated with a fluoropolymer. The resulting developer exhibits reduced toner throw-off and other disclosed advantages.
    Type: Grant
    Filed: March 23, 1984
    Date of Patent: January 29, 1985
    Assignee: Eastman Kodak Company
    Inventors: John C. Wilson, Lawrence P. DeMejo, Thomas A. Jadwin, Stewart H. Merrill
  • Patent number: 4495263
    Abstract: Electrophotographic elements are disclosed containing an photoconductor layer overlying, in sequence, an electrically conducting layer, a polyamide interlayer and a support. In preferred embodiments, the element additionally comprises an integral screen layer between the support and the polyamide interlayer.
    Type: Grant
    Filed: June 30, 1983
    Date of Patent: January 22, 1985
    Assignee: Eastman Kodak Company
    Inventor: Paul D. VanderValk
  • Patent number: 4493881
    Abstract: An electrophotographic method is disclosed for forming a black (or neutral) toner separation image and a color toner separation image from a single original without cross-contamination of black toner in the color separation image and vice versa. The method entails composing an original containing "false-color" information--other than black or neutral--corresponding to the black separation image desired and color information corresponding to the color separation image desired. The false-color and color information are selected to absorb actinic light in mutually exclusive wavelength regions of the spectrum. When the original is illuminated, for example, with light having wavelengths in the false-color absorption region only, a light pattern is formed and employed to expose a charged photoreceptor. The resulting electrostatic image is developed with black--or neutral--toner, thereby forming the black separation image.
    Type: Grant
    Filed: June 20, 1983
    Date of Patent: January 15, 1985
    Assignee: Eastman Kodak Company
    Inventors: John D. Mitchell, Stephen Michel
  • Patent number: 4480022
    Abstract: A method for developing an electrostatic latent image on a nonporous surface using a self-fixing liquid developer is described. The developer contains a volatile, electrically insulating carrier, and toner particles, dispersed in the carrier, containing a polymer binder which has a Tg within the range from about -10.degree. C. to 30.degree. C. Upon application of the developer to a latent image and evaporating the liquid carrier from the image, the toner particles fix to the surface without externally applied heat other than from ambient conditions.
    Type: Grant
    Filed: September 27, 1982
    Date of Patent: October 30, 1984
    Assignee: Eastman Kodak Company
    Inventors: Peter S. Alexandrovich, Stewart H. Merrill
  • Patent number: 4473626
    Abstract: Electrically photosensitive materials comprising electrically photosensitive colorant particles dispersed in a liquefiable, electrically insulating carrier containing a binder polymer and electropolymerizable bisphenol-acrylate monomers or mixtures of such monomers are disclosed. The disclosed materials are employed in photoelectrophoretic processes wherein the colorant particles are caused to migrate by the action of light and an electric field, while the material is electrohardened by the electric field.
    Type: Grant
    Filed: April 25, 1983
    Date of Patent: September 25, 1984
    Assignee: Eastman Kodak Company
    Inventors: Michel F. Molaire, Paul L. Nielsen, Orville C. Rodenberg
  • Patent number: 4468444
    Abstract: Photoconductive compositions and elements comprising arylalkane photoconductors and pyrylium sensitizers are stabilized against adverse leuco base color shifts into the ultraviolet to blue spectral region by the incorporation of certain 1,4,5,8-naphthalene bis-dicarboximide compounds. The compositions and elements are particularly suited for electrophotographic image formation and thereafter for contact printing of the image onto sensitive material by ultraviolet or blue transmission through the composition or element.
    Type: Grant
    Filed: April 21, 1983
    Date of Patent: August 28, 1984
    Assignee: Eastman Kodak Company
    Inventor: Lawrence E. Contois
  • Patent number: 4465749
    Abstract: A method for amplifying an electrostatic, charge-differential pattern is disclosed. The method comprises (a) imagewise forming a first toner deposit by developing a first electrostatic pattern having a first charge differential per unit area whose maximum value is no greater than a preselected level, (b) in an image-amplification element comprising a charge-holding surface layer overlying a field-supporting electrode, forming a current-carrying path between the toner deposit and the field-supporting electrode, (c) under conditions in which nontoned regions are not photoexcited, overall charging the image-amplification element with sufficient charge to form an enhanced electrostatic charge pattern having a second charge differential per unit area whose maximum value is greater than the preselected value in step (a), and (d) developing the enhanced charge pattern into a second toner deposit.
    Type: Grant
    Filed: June 20, 1983
    Date of Patent: August 14, 1984
    Assignee: Eastman Kodak Company
    Inventors: John W. May, Yee S. Ng
  • Patent number: 4463076
    Abstract: Electrically photosensitive complex cyanine colorant compounds, each comprising two merocyanine moieties joined by a cyanine moiety, are useful in electrically photosensitive materials for photoelectrophoretic (PEP) imaging processes. These compounds are symmetric or asymmetric and contain the structure: ##STR1## wherein: m and n, which are the same or different, are 0, 1 or 2;t and u, which are the same or different, are 0 or 1;p is 0, 1 or 2;R.sup.1 and R.sup.11, which are the same or different, represent an alkyl, aryl, aralkyl, alkaryl, carbocyclic or heterocyclic group or, when taken together and p is zero, are a one- or two-carbon alkylene bridge;R.sup.2 and R.sup.22, which are the same or different, represent an alkyl, aryl, aralkyl, alkaryl, carbocyclic or heterocyclic group;R.sup.3 and R.sup.33, which are the same or different, represent hydrogen or an alkyl group;R.sup.4 and R.sup.44, which are the same or different, represent hydrogen or an alkyl group;R.sup.4, which when taken together with R.sup.
    Type: Grant
    Filed: February 22, 1983
    Date of Patent: July 31, 1984
    Assignee: Eastman Kodak Company
    Inventors: Steven G. Link, Frank G. Webster
  • Patent number: 4463078
    Abstract: Polymeric photoconductors are disclosed comprising a condensation polymer backbone containing, as repeating units, the condensation residues of (1) a diacid, and (2) an organic difunctional compound capable of undergoing condensation polymerization with said diacid, and an arylamine photoconductor group appended to at least one of said diacid or said organic difunctional compound residues.A preferred polymeric photoconductor is ionic and comprises a condensation copolymer containing, in addition to the above described repeating units, the condensation residue of a second diacid containing an anionic iminodisulfonyl or sulfo group. In certain embodiments, the ionic arylamine-containing polymers are water-dispersible copolyesters.The polymeric photoconductors described are useful in photoconductive compositions and elements. Electrophotographic processes employing such elements are also disclosed.
    Type: Grant
    Filed: May 5, 1983
    Date of Patent: July 31, 1984
    Assignee: Eastman Kodak Company
    Inventors: John M. Noonan, Jerome H. Perlstein
  • Patent number: 4450216
    Abstract: A method for improving the sensitometric response of a persistently conductive photoreceptor is disclosed. This method involves charging and exposing the photoreceptor to form a latent electrostatic image and thereafter, within the period of persistence, recharging the photoreceptor to the same polarity and developing the latent electrostatic image.
    Type: Grant
    Filed: November 22, 1982
    Date of Patent: May 22, 1984
    Assignee: Eastman Kodak Company
    Inventors: George G. Fulmer, John R. Lawson
  • Patent number: 4442193
    Abstract: Photoconductive compositions comprising photoconductors and 1,4,5,8-naphthalene bis-dicarboximide sensitizing compounds are disclosed. Compositions and elements containing such compounds are sensitized to radiation below 400 nm. Embodiments are disclosed in which the photoconductor is an arylalkane leuco base. Such embodiments are advantageously nonsensitive to radiation above 400 nm and are also nonpersistent.
    Type: Grant
    Filed: February 22, 1983
    Date of Patent: April 10, 1984
    Assignee: Eastman Kodak Company
    Inventors: Chin H. Chen, Ralph H. Young, Michael Scozzafava
  • Patent number: 4424268
    Abstract: Protonic acid-free photoconductive compositions and elements comprising a photoconductor and, as a sensitizer, a 4-tertiaryaminobenzo?b!pyrylium salt or a 4-tertiaryaminobenzo?b!thiopyrylium salt. The resulting compositions and elements exhibit low persistent conductivity.
    Type: Grant
    Filed: November 22, 1982
    Date of Patent: January 3, 1984
    Assignee: Eastman Kodak Company
    Inventors: Martin A. Berwick, Lawrence E. Contois, George A. Reynolds
  • Patent number: 4423203
    Abstract: Disclosed are electrically photosensitive polymers in which recurring units contain vinylene-1,4-phenylene-imino-1,4-phenylene-vinylenearylene groups included in the polymer backbone. In one embodiment, the disclosed polymers are employed as the principal electrically photosensitive constituent in migration imaging dispersions and elements. In another embodiment, the polymers are employed as sensitizers for electrically photosensitive colorants having spectral absorption peaks in the 400-500 nm wavelength region of the spectrum. The polymers are employed in migration imaging dispersions and elements.
    Type: Grant
    Filed: August 20, 1982
    Date of Patent: December 27, 1983
    Assignee: Eastman Kodak Company
    Inventors: Peter J. Corvan, Jeanne E. Kaeding, Cesar Rodriguez, Norman G. Rule
  • Patent number: 4395475
    Abstract: Polymeric photoconductors are disclosed comprising a condensation polymer backbone containing, as repeating units, the condensation residues of (1) a diacid, and (2) an organic difunctional compound capable of undergoing condensation polymerization with said diacid, and an arylamine photoconductor group appended to at least one of said diacid or said organic difunctional compound residues.A preferred polymeric photoconductor is ionic and comprises a condensation copolymer containing, in addition to the above described repeating units, the condensation residue of a second diacid containing an anionic iminodisulfonyl or sulfo group. In certain embodiments, the ionic arylamine-containing polymers are water-dispersible copolyesters.The polymeric photoconductors described are useful in photoconductive compositions and elements. Electrophotographic processes employing such elements are also disclosed.
    Type: Grant
    Filed: July 20, 1981
    Date of Patent: July 26, 1983
    Assignee: Eastman Kodak Company
    Inventors: John M. Noonan, Jerome H. Perlstein
  • Patent number: 4385823
    Abstract: In a novel electrographic copying method and apparatus, a latent electrostatic image is formed on an insulating layer of an electrophotographic element and, before, during or after the formation of the latent electrostatic image, there is created a plurality of charge islands, such as by an exposure through a screen. These charge islands are distinct and in addition to any charge islands which result from the image-forming step. After establishment of the charge islands and the latent electrostatic image, the resulting charge pattern is developed with a developer which either is at least partially conductive, i.e., has a maximum resistance of about 10.sup.9 ohms, or is rendered so by the phenomenon of electrical breakdown.
    Type: Grant
    Filed: March 24, 1980
    Date of Patent: May 31, 1983
    Assignee: Eastman Kodak Company
    Inventors: George P. Kasper, Arthur S. Kroll, Michael Mosehauer
  • Patent number: 4382033
    Abstract: Novel phthalocyanine pigments having the structure: ##STR1## wherein: R.sub.1 represents ##STR2## n represents 1, 2, 3 or any combination of 1, 2 and 3. R.sub.2, R.sub.3, R.sub.4 and R.sub.5 represent alkyl, alkylaryl, alkoxy, alkoxyaryl, cycloalkyl, aryl, aralkyl or aryloxy;R.sub.6 represents hydrogen or chlorine andAlPc represents ##STR3## are useful in electrographic developers and photoelectrophoretic imaging materials and processes.
    Type: Grant
    Filed: October 5, 1981
    Date of Patent: May 3, 1983
    Assignee: Eastman Kodak Company
    Inventor: Michael T. Regan
  • Patent number: 4361636
    Abstract: Novel polyesters comprising repeating units from:(a) a diacid derived component comprising a group selected from the class consisting of an alkali metal or ammonium -sulfoarylene, -sulfoaryloxyarylene, -sulfocycloalkylene, -iminodisulfonylarylene, -iminobis(sulfonylarylene) or -sulfoaralkylarylene; and(b) a diol or diacid derived component comprising a group selected from the class consisting of bis(N-alkyl-N-alkyleneaminoaryl)arylalkane; bis(N-alkyl-N-alkyleneaminoaryl)diarylalkane; bis(N-alkyl-N-alkyleneaminoaryl)isoalkane; bis(N-alkyl-N-alkyleneaminoaryl)cycloalkane; dialkyleneaminotetraarylalkane; bis(alkylenearyl)arylamine and alkylenetriarylamine;are useful in electrically photosensitive composite particles, materials, layers and photoelectrophoretic imaging methods.
    Type: Grant
    Filed: April 22, 1981
    Date of Patent: November 30, 1982
    Assignee: Eastman Kodak Company
    Inventors: Henry V. Isaacson, Michael T. Regan
  • Patent number: 4350751
    Abstract: A plurality of aggregate photoconductive particles having a predominant particle size of less than about 1.0 micron are disclosed. Such particles are useful in heterogeneous photoconductive compositions, electrophotographic elements and electrophotographic imaging processes.
    Type: Grant
    Filed: July 6, 1981
    Date of Patent: September 21, 1982
    Assignee: Eastman Kodak Company
    Inventor: Lawrence E. Contois
  • Patent number: 4341894
    Abstract: Sensitizers for photoconductive compositions and elements are disclosed. The sensitizers are 2,4,6 tri substituted pyrylium dye salts wherein at least one of said substituents is a 5 or 6 membered heterocyclic ring having at least one atom selected from the group consisting of N, O and S.
    Type: Grant
    Filed: April 26, 1979
    Date of Patent: July 27, 1982
    Assignee: Eastman Kodak Company
    Inventors: Michael T. Regan, George A. Reynolds, Donald P. Specht, James A. VanAllan