Toner compositions comprising polyester resin and polypyrrole

• US 6,743,559 B2
• Filed: 01/23/2003
• Issued: 06/01/2004
• Est. Priority Date: 11/28/2000
• Status: Expired due to Fees

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Moffat, Karen A., McDougall, Maria N. V., Combes, James R.
• Primary Examiner(s): Dote, Janis L.
• Application Number:
  US10/350,534
• Publication Number:
  US 20030175609A1
• Time in Patent Office: 495 Days
• Field of Search: 430/108.22, 430/110.2, 430/137.14, 430/137.12, 430/137.19, 430/137.2, 430/109.4, 430/137.11, 430/120, 399/285
• US Class Current: 430/123.56
• CPC Class Codes: G03G 9/0804 whereby the components are brought together in a liquid dispersing medium
• CPC Class Codes: G03G 9/0819 characterised by the dimensions of the particles
• CPC Class Codes: G03G 9/08755 Polyesters
• CPC Class Codes: G03G 9/08768 Other polymers having nitrogen in the main chain, with or without oxygen or carbon only
• CPC Class Codes: G03G 9/08795 characterised by their chemical properties, e.g. acidity, molecular weight, sensitivity to reactants
• CPC Class Codes: G03G 9/08797 characterised by their physical properties, e.g. viscosity, solubility, melting temperature, softening temperature, glass transition temperature
• CPC Class Codes: G03G 9/09741 cationic
• CPC Class Codes: G03G 9/09758 comprising a heterocyclic ring

Abstract

Disclosed is a toner comprising particles of a polyester resin, an optional colorant, and polypyrrole, wherein said toner particles are prepared by an emulsion aggregation process. Another embodiment of the present invention is directed to a process which comprises (a) generating an electrostatic latent image on an imaging member, and (b) developing the latent image by contacting the imaging member with charged toner particles comprising a polyester resin, an optional colorant, and polypyrrole, wherein said toner particles are prepared by an emulsion aggregation process.

Claims

1. A process which comprises (a) generating an electrostatic latent image on an imaging member, and (b) developing the latent image by contacting the imaging member with charged toner particles comprising a polyester resin, an optional colorant, and polypyrrole, wherein said toner particles are prepared by an emulsion aggregation process, wherein the toner particles comprise a core comprising the polyester resin and optional colorant and, coated on the core, a coating comprising the polypyrrole, wherein the polypyrrole has at least about 3 repeat monomer units and wherein the polypyrrole has no more than about 100 repeat monomer units.

2. A process according to claim 1 wherein the toner particles have an average particle diameter of no more than about 13 microns.

3. A process according to claim 1 wherein the polyester resin is polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polypentylene terephthalate, polyhexalene terephthalate, polyheptadene terephthalate, polyoctalene-terephthalate, poly(propylene-diethylene terephthalate), poly(bisphenol A-fumarate), poly(bisphenol A-terephthalate), copoly(bisphenol A-terephthalate)-copoly(bisphenol A-fumarate), poly(neopentyl-terephthalate), or mixtures thereof.

4. A process according to claim 1 wherein the polyester resin is a sulfonated polyester.

5. A process according to claim 1 wherein the polyester resin is a salt of a poly(1,2-propylene-5-sulfoisophthalate), a poly(neopentylene-5-sulfoisophthalate), a poly(diethylene-5-sulfoisophthalate), a copoly(1,2-propylene-5-sulfoisophthalate)-copoly-(1,2-propylene-terephthalate phthalate), a copoly(1,2-propylene-diethylene-5-sulfoisophthalate)-copoly-(1,2-propylene-diethylene-terephthalate phthalate), a copoly(ethylene-neopentylene-5-sulfoisophthalate)-copoly-(ethylene-neopentylene-terephthalate-phthalate), a copoly(propoxylated bisphenol A)-copoly-(propoxylated bisphenol A-5-sulfoisophthalate), a copoly(ethylene-terephthalate)-copoly-(ethylene-5-sulfoisophthalate), a copoly(propylene-terephthalate)-copoly-(propylene-5-sulfoisophthalate), a copoly(diethylene-terephthalate)-copoly-(diethylene-5-sulfoisophthalate), a copoly(propylene-diethylene-terephthalate)-copoly-(propylene-diethylene-5-sulfoisophthalate), a copoly(propylene-butylene-terephthalate)-copoly(propylene-butylene-5-sulfoisophthalate), a copoly(propoxylated bisphenol-A-fumarate)-copoly(propoxylated bisphenol A-5-sulfoisophthalate), a copoly(ethoxylated bisphenol-A-fumarate)-copoly(ethoxylated bisphenol-A-5-sulfoisophthalate), a copoly(ethoxylated bisphenol-A-maleate)-copoly(ethoxylated bisphenol-A-5-sulfoisophthalate), a copoly(propylene-diethylene terephthalate)-copoly(propylene-5-sulfoisophthalate), a copoly(neopentyl-terephthalate)-copoly-(neopentyl-5-sulfoisophthalate), or a mixture thereof.

6. A process according to claim 1 wherein the resin is present in the toner particles in an amount of at least about 75 percent by weight of the toner particles and wherein the resin is present in the toner particles in an amount of no more than about 99 percent by weight of the toner particles.

7. A process according to claim 1 wherein the toner particles further comprise a pigment colorant.

8. A process according to claim 1 wherein the toner particles contain a colorant, said colorant being present in an amount of at least about 1 percent by weight of the toner particles, and said colorant being present in an amount of no more than about 25 percent by weight of the toner particles.

9. A process according to claim 1 wherein the emulsion aggregation process comprises (1) shearing a first ionic surfactant with a latex mixture comprising (a) a counterionic surfactant with a charge polarity of opposite sign to that of said first ionic surfactant, (b) a nonionic surfactant, and (c) the polyester resin, thereby causing flocculation or heterocoagulation of formed particles of resin to form electrostatically bound aggregates;

and (2) healing the electrostatically bound aggregates to form aggregates of at least about 1 micron in average particle diameter.

10. A process according to claim 1 wherein the emulsion aggregation process comprises (1) preparing a colorant dispersion in a solvent, which dispersion comprises a colorant and a first ionic surfactant;

(2) shearing the colorant dispersion with a latex mixture comprising (a) a counterionic surfactant with a charge polarity of opposite sign to that of said first ionic surfactant, (b) a nonionic surfactant, and (c) the polyester resin, thereby causing flocculation or heterocoagulation of formed particles of colorant and resin to form electrostatically bound aggregates; and

(3) heating the electrostatically bound aggregates to form aggregates of at least about 1 micron in average particle diameter.

11. A process according to claim 1 wherein the emulsion aggregation process comprises (1) shearing an ionic surfactant with a latex mixture comprising (a) a flocculating agent, (b) a nonionic surfactant, and (c) the polyester resin, thereby causing flocculation or heterocoagulation of formed particles of resin to form electrostatically bound aggregates;

and (2) heating the electrostatically bound aggregates to form aggregates of at least about 1 micron in average particle diameter.

12. A process according to claim 1 wherein the emulsion aggregation process comprises (1) preparing a colorant dispersion in a solvent, which dispersion comprises a colorant and an ionic surfactant;

(2) shearing the colorant dispersion with a latex mixture comprising (a) a flocculating agent, (b) a nonionic surfactant, and (c) the polyester resin, thereby causing flocculation or heterocoagulation of formed particles of colorant and resin to form electrostatically bound aggregates; and

(3) heating the electrostatically bound aggregates to form aggregates of at least about 1 micron in average particle diameter.

13. A process according to claim 1 wherein the emulsion aggregation process comprises (1) preparing a colloidal solution comprising the polyester resin and the optional colorant, and (2) adding to the colloidal solution an aqueous solution containing a coalescence agent comprising an ionic metal salt to form toner particles.

14. A process according to claim 1 wherein the polypyrrole is of the formula

wherein D−

corresponds to the dopant and n is an integer representing the number of repeat monomer units.

15. A process according to claim 1 wherein the polypyrrole has at least about 6 repeat monomer units and wherein the polypyrrole has no more than about 100 repeat monomer units.

16. A process according to claim 1 wherein the polypyrrole is doped with iodine, molecules containing sulfonate groups, molecules containing phosphate groups, molecules containing phosphonate groups, or mixtures thereof.

17. A process according to claim 1 wherein the polypyrrole is doped with sulfonate containing anions of the formula RSO₃₋

wherein R is an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an arylalkyl group, an alkylaryl group, an arylalkyloxy group, an alkylaryloxy group, or mixtures thereof.

18. A process according to claim 1 wherein the polypyrrole is doped with anions selected from p-toluene sulfonate, camphor sulfonate, benzene sulfonate, naphthalene sulfonate, dodecyl sulfonate, dodecylbenzene sulfonate, dialkyl benzenealkyl sulfonates, para-ethylbenzene sulfonate, alkyl naphthalene sulfonates, poly(styrene sulfonate), or mixtures thereof.

19. A process according to claim 1 wherein the polypyrrole is doped with anions selected from p-toluene sulfonate, camphor sulfonate, benzene sulfonate, naphthalene sulfonate, dodecyl sulfonate, dodecylbenzene sulfonate, 1,3-benzene disulfonate, para-ethylbenzene sulfonate, 1,5-naphthalene disulfonate, 2-naphthalene disulfonate, poly(styrene sulfonate), or mixtures thereof.

20. A process according to claim 1 wherein the polypyrrole is doped with a dopant present in an amount of at least about 0.1 molar equivalent of dopant per molar equivalent of pyrrole monomer and present in an amount of no more than about 5 molar equivalents of dopant per molar equivalent of pyrrole monomer.

21. A process according to claim 1 wherein the polypyrrole is doped with a dopant present in an amount of at least about 0.25 molar equivalent of dopant per molar equivalent of pyrrole monomer and present in an amount of no more than about 4 molar equivalents of dopant per molar equivalent of pyrrole monomer.

22. A process according to claim 1 wherein the polypyrrole is doped with a dopant present in an amount of at least about 0.5 molar equivalent of dopant per molar equivalent of pyrrole monomer and present in an amount of no more than about 3 molar equivalents of dopant per molar equivalent of pyrrole monomer.

23. A process according to claim 1 wherein the toner particles have an average bulk conductivity of no more than about 10⁻

12 Siemens per centimeter.

24. A process according to claim 1 wherein the toner particles have an average bulk conductivity of no more than about 10⁻

13 Siemens per centimeter, and wherein the toner particles have an average bulk conductivity of no less than about 10<sup>−

16</sup> Siemens per centimeter.

25. A process according to claim 1 wherein the toner particles have an average bulk conductivity of no less than about 10⁻

11 Siemens per centimeter.

26. A process according to claim 1 wherein the toner particles have an average bulk conductivity of no less than about 10^{31 7} Siemens per centimeter.

27. A process according to claim 1 wherein the polypyrrole is present in an amount of at least about 5 weight percent of the toner particle mass and wherein the polypyrrole is present in an amount of no more than about 20 weight percent of the toner particle mass.

28. A process according to claim 1 wherein the toner particles are charged triboelectrically.

29. A process according to claim 28 wherein the toner particles are charged triboelectrically by admixing them with carrier particles.

30. A process for developing a latent image recorded on a surface of an image receiving member to form a developed image, said process comprising (a) moving the surface of the image receiving member at a predetermined process speed;

(b) storing in a reservoir a supply of toner particles comprising a polyester resin, an optional colorant, and polypyrrole, wherein said toner particles are prepared by an emulsion aggregation process;

(c) transporting the toner particles on an outer surface of a donor member to a development zone adjacent the image receiving member; and

(d) inductive charging said toner particles on said outer surface of said donor member prior to the development zone to a predefined charge level, wherein the inductive charging step includes the step of biasing the toner reservoir relative to the bias on the donor member.

31. A process according to claim 30 wherein the donor member is brought into synchronous contact with the imaging member to detach toner in the development zone from the donor member, thereby developing the latent image.

32. A process according to claim 30 wherein the predefined charge level has an average toner charge-to-mass ratio of from about 5 to about 50 microCoulombs per gram in magnitude.

33. A process which comprises (a) generating an electrostatic latent image on an imaging member, and (b) developing the latent image by contacting the imaging member with charged toner particles comprising a polyester resin, an optional colorant, and polypyrrole, wherein said toner particles are prepared by an emulsion aggregation process, wherein the toner particles are charged by a nonmagnetic inductive charging process, wherein the toner particles are charged in a developing apparatus which comprises a housing defining a reservoir storing a supply of developer material comprising the toner particles;

a donor member for transporting toner particles on an outer surface of said donor member to a development zone;

means for loading a layer of toner particles onto said outer surface of said donor member; and

means for inductive charging said toner layer onto said outer surface of said donor member prior to the development zone to a predefined charge level, wherein said inductive charging means comprises means for biasing said toner reservoir relative to the bias on the donor member.

34. A process according to claim 33 wherein the toner particles have an average particle diameter of no more than about 13 microns.

35. A process according to claim 33 wherein the toner particles comprise a core comprising the polyester resin and optional colorant and, coated on the core, a coating comprising the polypyrrole.

36. A process according to claim 33 wherein the polyester resin is polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polypentylene terephthalate, polyhexalene terephthalate, polyheptadene terephthalate, polyoctalene-terephthalate, poly(propylene-diethylene terephthalate), poly(bisphenol A-fumarate), poly(bisphenol A-terephthalate), copoly(bisphenol A-terephthalate)-copoly(bisphenol A-fumarate), poly(neopentyl-terephthalate), or mixtures thereof.

37. A process according to claim 33 wherein the polyester resin is a sulfonated polyester.

38. A process according to claim 33 wherein the polyester resin is a salt of a poly(1,2-propylene-5-sulfoisophthalate), a poly(neopentylene-5-sulfoisophthalate), a poly(diethylene-5-sulfoisophthalate), a copoly(1,2-propylene-5-sulfoisophthalate)-copoly-(1,2-propylene-terephthalate phthalate), a copoly(1,2-propylene-diethylene-5-sulfoisophthalate)-copoly-(1,2-propylene-diethylene-terephthalate phthalate), a copoly(ethylene-neopentylene-5-sulfoisophthalate)-copoly-(ethylene-neopentylene-terephthalate-phthalate), a copoly(propoxylated bisphenol A)-copoly-(propoxylated bisphenol A-5-sulfoisophthalate), a copoly(ethylene-terephthalate)-copoly-(ethylene-5-sulfoisophthalate), a copoly(propylene-terephthalate)-copoly-(propylene-5-sulfoisophthalate), a copoly(diethylene-terephthalate)-copoly-(diethylene-5-sulfoisophthalate), a copoly(propylene-diethylene-terephthalate)-copoly-(propylene-diethylene-5-sulfoisophthalate), a copoly(propylene-butylene-terephthalate)-copoly(propylene-butylene-5-sulfoisophthalate), a copoly(propoxylated bisphenol-A-fumarate)-copoly(propoxylated bisphenol A-5-sulfoisophthalate), a copoly(ethoxylated bisphenol-A-fumarate)-copoly(ethoxylated bisphenol-A-5-sulfoisophthalate), a copoly(ethoxylated bisphenol-A-maleate)-copoly(ethoxylated bisphenol-A-5-sulfoisophthalate), a copoly(propylene-diethylene terephthalate)-copoly(propylene-5-sulfoisophthalate), a copoly(neopentyl-terephthalate)-copoly-(neopentyl-5-sulfoisophthalate), or a mixture thereof.

39. A process according to claim 33 wherein the resin is present in the toner particles in an amount of at least about 75 percent by weight of the toner particles and wherein the resin is present in the toner particles in an amount of no more than about 99 percent by weight of the toner particles.

40. A process according to claim 33 wherein the toner particles further comprise a pigment colorant.

41. A process according to claim 33 wherein the toner particles contain a colorant, said colorant being present in an amount of at least about 1 percent by weight of the toner particles, and said colorant being present in an amount of no more than about 25 percent by weight of the toner particles.

42. A process according to claim 33 wherein the emulsion aggregation process comprises (1) shearing a first ionic surfactant with a latex mixture comprising (a) a counterionic surfactant with a charge polarity of opposite sign to that of said first ionic surfactant, (b) a nonionic surfactant, and (c) the polyester resin, thereby causing flocculation or heterocoagulation of formed particles of resin to form electrostatically bound aggregates;

and (2) healing the electrostatically bound aggregates to form aggregates of at least about 1 micron in average particle diameter.

43. A process according to claim 33 wherein the emulsion aggregation process comprises (1) preparing a colorant dispersion in a solvent, which dispersion comprises a colorant and a first ionic surfactant;

(2) shearing the colorant dispersion with a latex mixture comprising (a) a counterionic surfactant with a charge polarity of opposite sign to that of said first ionic surfactant, (b) a nonionic surfactant, and (c) the polyester resin, thereby causing flocculation or heterocoagulation of formed particles of colorant and resin to form electrostatically bound aggregates; and

(3) heating the electrostatically bound aggregates to form aggregates of at least about 1 micron in average particle diameter.

44. A process according to claim 33 wherein the emulsion aggregation process comprises (1) shearing an ionic surfactant with a latex mixture comprising (a) a flocculating agent, (b) a nonionic surfactant, and (c) the polyester resin, thereby causing flocculation or heterocoagulation of formed particles of resin to form electrostatically bound aggregates;

and (2) heating the electrostatically bound aggregates to form aggregates of at least about 1 micron in average particle diameter.

45. A process according to claim 33 wherein the emulsion aggregation process comprises (1) preparing a colorant dispersion in a solvent, which dispersion comprises a colorant and an ionic surfactant;

(2) shearing the colorant dispersion with a latex mixture comprising (a) a flocculating agent, (b) a nonionic surfactant, and (c) the polyester resin, thereby causing flocculation or heterocoagulation of formed particles of colorant and resin to form electrostatically bound aggregates; and

(3) heating the electrostatically bound aggregates to form aggregates of at least about 1 micron in average particle diameter.

46. A process according to claim 33 wherein the emulsion aggregation process comprises (1) preparing a colloidal solution comprising the polyester resin and the optional colorant, and (2) adding to the colloidal solution an aqueous solution containing a coalescence agent comprising an ionic metal salt to form toner particles.

47. A process according to claim 33 wherein the polypyrrole is of the formula

wherein D−

corresponds to the dopant and n is an integer representing the number of repeat monomer units.

48. A process according to claim 33 wherein the polypyrrole has at least about 3 repeat monomer units.

49. A process according to claim 33 wherein the polypyrrole has at least about 6 repeat monomer units and wherein the polypyrrole has no more than about 100 repeat monomer units.

50. A process according to claim 33 wherein the polypyrrole is doped with iodine, molecules containing sulfonate groups, molecules containing phosphate groups, molecules containing phosphonate groups, or mixtures thereof.

51. A process according to claim 33 wherein the polypyrrole is doped with sulfonate containing anions of the formula RSO₃₋

wherein R is an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an arylalkyl group, an alkylaryl group, an arylalkyloxy group, an alkylaryloxy group, or mixtures thereof.

52. A process according to claim 33 wherein the polypyrrole is doped with anions selected from p-toluene sulfonate, camphor sulfonate, benzene sulfonate, naphthalene sulfonate, dodecyl sulfonate, dodecylbenzene sulfonate, dialkyl benzenealkyl sulfonates, para-ethylbenzene sulfonate, alkyl naphthalene sulfonates, poly(styrene sulfonate), or mixtures thereof.

53. A process according to claim 33 wherein the polypyrrole is doped with anions selected from p-toluene sulfonate, camphor sulfonate, benzene sulfonate, naphthalene sulfonate, dodecyl sulfonate, dodecylbenzene sulfonate, 1,3-benzene disulfonate, para-ethylbenzene sulfonate, 1,5-naphthalene disulfonate, 2-naphthalene disulfonate, poly(styrene sulfonate), or mixtures thereof.

54. A process according to claim 33 wherein the polypyrrole is doped with a dopant present in an amount of at least about 0.1 molar equivalent of dopant per molar equivalent of pyrrole monomer and present in an amount of no more than about 5 molar equivalents of dopant per molar equivalent of pyrrole monomer.

55. A process according to claim 33 wherein the polypyrrole is doped with a dopant present in an amount of at least about 0.25 molar equivalent of dopant per molar equivalent of pyrrole monomer and present in an amount of no more than about 4 molar equivalents of dopant per molar equivalent of pyrrole monomer.

56. A process according to claim 33 wherein the polypyrrole is doped with a dopant present in an amount of at least about 0.5 molar equivalent of dopant per molar equivalent of pyrrole monomer and present in an amount of no more than about 3 molar equivalents of dopant per molar equivalent of pyrrole monomer.

57. A process according to claim 33 wherein the toner particles have an average bulk conductivity of no less than about 10⁻

11 Siemens per centimeter.

58. A process according to claim 33 wherein the toner particles have an average bulk conductivity of no less than about 10^{31 7} Siemens per centimeter.

59. A process according to claim 33 wherein the polypyrrole is present in an amount of at least about 5 weight percent of the toner particle mass and wherein the polypyrrole is present in an amount of no more than about 20 weight percent of the toner particle mass.

60. A process according to claim 33 wherein the predefined charge level has an average toner charge-to-mass ratio of from about 5 to about 50 microCoulombs per gram in magnitude.