Claims
- 1. Carrier comprised of a hard magnetic core, the pores thereof containing polymer, and thereover a coating.
- 2. Carrier comprised of a porous hard magnetic core and wherein a number of the pores thereof contain a (1) polymer, or a mixture of polymers and which carrier contains a (2) coating thereover of a polymer, or a mixture of polymers.
- 3. Carrier in accordance with claim 2 wherein substantially all of said carrier pores contain said polymer (1) and said polymer (2) and each (1) and/or (2) further contains conductive components.
- 4. Carrier in accordance with claim 2 wherein said core diameter is about 30 to about 100 microns.
- 5. Carrier in accordance with claim 2 wherein said polymer (1) is a crosslinked polymer and said polymer (2) is a crosslinked polymer.
- 6. Carrier in accordance with claim 2 wherein porous is represented by a BET area of about 500 to about 5,000 cm.sup.2 /gram.
- 7. Carrier in accordance with claim 2 wherein porous is represented by a BET area of about 1,000 to about 3,000 cm.sup.2 /gram.
- 8. Carrier in accordance with claim 2 wherein said core is a ferrite.
- 9. Carrier in accordance with claim 2 wherein said core is strontium ferrite.
- 10. Carrier in accordance with claim 2 wherein said core is strontium ferrite containing lanthanum in an amount of from about 1 to about 5 percent by weight, or from about 2 to about 4.5 percent by weight.
- 11. Carrier in accordance with claim 2 wherein said polymer (1), and said polymer (2) is a vinyl polymer or a condensation polymer.
- 12. Carrier in accordance with claim 2 wherein polymer (1) is polyvinylidenefluoride, polyethylene, polymethylmethacrylate, polytrifluoroethylmethacrylate, copolyethylenevinylacetate, copolyvinylidenefluoride, tetrafluoroethylene, polystyrene, tetrafluoroethylene, polyvinyl chloride, polyvinyl acetate, polyvinyl acetate, or mixtures thereof, and wherein said polymer (2) is polyvinylidenefluoride, polyethylene, polymethylmethacrylate, polytrifluoroethylmethacrylate, copolyethylenevinylacetate, copolyvinylidenefluoride, tetrafluoroethylene, polystyrene, tetrafluoroethylene, polyvinyl chloride, polyvinyl acetate, polyvinyl acetate, or mixtures thereof.
- 13. Carrier in accordance with claim 2 wherein said polymer (1) is polymethylmethacrylate, polystyrene, polytrifluoroethylmethacrylate, or mixtures thereof, and said polymer (2) is polymethylmethacrylate, polystyrene, polytrifluoroethylmethacrylate, or mixtures thereof.
- 14. Carrier in accordance with claim 2 wherein said polymer (1) and said polymer (2) is comprised of a mixture of polymethylmethacrylate, and polytrifluoroethylmethacrylate.
- 15. Carrier in accordance with claim 3 wherein said conductive component is conductive carbon black, metal oxide, metal, or mixtures thereof.
- 16. Carrier in accordance with claim 3 wherein said conductive component is carbon black.
- 17. Carrier in accordance with claim 2 wherein said polymer (1) and said polymer (2) is present in a total amount of from about 0.5 to about 10 percent by weight of said carrier.
- 18. Carrier in accordance with claim 2 wherein said polymer (1) and said polymer (2) is present in a total amount of from about 1 to about 5 percent by weight of said carrier.
- 19. Carrier in accordance with claim 3 wherein said conductive component is present in an amount of from about 10 to about 70 percent by weight of said polymer (1), and/or said polymer (2).
- 20. Carrier in accordance with claim 3 wherein said conductive component is present in an amount of from about 20 to about 50 percent by weight of said polymer (1), or said polymer (2).
- 21. Carrier in accordance with claim 2 with a triboelectric charge value of from about -80 to about 80 microcoulombs/gram.
- 22. Carrier in accordance with claim 2 with a conductivity of from about 10.sup.-17 to about 10.sup.-4 mho/cm.
- 23. Carrier in accordance with claim 2 with a triboelectric charge value of from about -60 to about 60 microcoulombs/gram and a conductivity of from about 10.sup.-15 to about 10.sup.-6 mho/cm.
- 24. Carrier in accordance with claim 2 with a magnetic coercivity of from about 300 to about 6,000 gauss.
- 25. Carrier in accordance with claim 2 with an induced magnetic moment of from about 20 to about 100 EMU/g in an applied field of about 1,000 gauss.
- 26. Carrier in accordance with claim 2 with a magnetic coercivity of from about 1,000 to about 3,000 gauss, and an induced magnetic moment of from about 30 to about 60 EMU/g in an applied field of about 1,000 gauss.
- 27. A process for the preparation of carrier comprised of mixing hard magnetic carrier core with monomer or a mixture of monomers and initiator, optional chain transfer agent, and optional crosslinking agent; polymerizing the monomer by heating thereby resulting in a polymer, contained in a number of the carrier pores and on the carrier surface; and optionally drying.
- 28. An insitu process for the preparation of carrier comprising mixing hard magnetic carrier core with monomer and initiator, optional chain transfer agent, and optional crosslinking agent; polymerizing the monomer by heating thereby resulting in a polymer contained in the carrier pores and on the carrier surface; removing excess monomer; mixing the carrier core containing polymer and monomer mixture inside the pores and on the carrier surface with water; completing the polymerization and optionally crosslinking by heating thereby resulting in a polymer, or crosslinked polymer in the carrier pores and on the carrier surface; removing the water from the mixture; and optionally drying.
- 29. A process in accordance with claim 27 wherein the monomer or monomer mixture further contains a conductive additive.
- 30. A process in accordance with claim 28 wherein excess monomer is removed by filtration; the water is removed from the mixture by filtration; and drying in an oven.
- 31. A process in accordance to claim 27 wherein the monomer and monomer mixture are heated at a temperature from about 50.degree. C. to about 95.degree. C., or from about 60.degree. C. to about 85.degree. C.
- 32. A process in accordance to claim 27 wherein the monomer or monomer mixture is heated for a period of from about 30 minutes to about 5 hours, or from about 30 minutes to about 3 hours.
- 33. A process in accordance to claim 27 wherein the monomer is selected from the group consisting of styrene, .alpha.-methyl styrene, p-chlorostyrene, monocarboxylic acids and the derivatives thereof; dicarboxylic acids with a double bond and their derivatives; vinyl ketones; vinyl naphthalene; unsaturated mono-olefins; vinylidene halides; N-vinyl compounds; fluorinated vinyl compounds; and mixtures thereof; and wherein said monomer is present in an amount of from about 0.5 to about 10 percent by weight, or from about 1 to about 5 percent by weight of said carrier core.
- 34. A process in accordance to claim 27 wherein the monomer is selected from the group consisting of acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, n-octyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methylalphachloracrylate, methacrylic acids, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acylonitrile, methacrylonitrile and acrylamide; maleic acid, monobutyl maleate, dibutyl maleate; as vinyl chloride, vinyl bromide, vinyl fluoride, vinyl acetate and vinyl benzoate; vinylidene chloride; pentafluoro styrene, allyl pentafluorobenzene, N-vinyl pyrrole, and trifluoroethyl methacrylate; and mixtures thereof; and wherein said monomer is present in an amount of from about 0.5 to about 10 percent by weight, or from about 1 to about 5 percent by weight of said carrier core.
- 35. A process in accordance to claim 27 wherein the monomer is methyl methacrylate, styrene, trifluoroethyl methacrylate, or mixtures thereof; and wherein said monomer is present in an amount of from about 0.5 to about 10 percent by weight, or from about 1 to about 5 percent by weight of said carrier core.
- 36. A process in accordance to claim 29 wherein the conductive additive is selected from the group consisting of conductive carbon blacks, metal oxides, metals, and mixtures thereof, and where the amount of said conductive additive is in the range of from about 10 to about 70 percent by weight, or from about 20 to about 50 percent by weight of said monomer.
- 37. A process in accordance to claim 29 wherein the conductive additive is conductive carbon black.
- 38. A process in accordance to claim 27 wherein the initiator is selected from the group consisting of azo compounds, peroxides, and mixtures thereof, and where the amount of said initiator is from about 0.1 to about 20 percent by weight, or from about 0.5 to about 10 percent by weight of said monomer mixture or comonomer mixture.
- 39. A process in accordance to claim 27 wherein the initiator is selected from the group consisting of 2,2'azodimethylvaleronitrile, 2,2'azoisobutyronitrile, azobiscyclohexanenitrile, 2-methylbutyronitrile, benzoyl peroxides, lauryl peroxide, 1-1-(t-butylperoxy)-3,3,5-trimethylcyclohexane, n-butyl-4,4-di-(t-butylperoxy)valerate, dicumyl peroxide, and mixtures thereof.
- 40. A process in accordance to claim 27 wherein the crosslinking agent is selected from the group consisting of compounds having two or more polymerizable double bonds, and where the amount of said crosslinking agent is in the range of from about 0.1 to about 5 percent by weight, or from about 0.5 to about 3 percent by weight.
- 41. A process in accordance to claim 27 wherein the crosslinking agent is selected from the group consisting of divinylbenzene, divinylnaphthalene, ethylene glycol diacrylate, ethylene glycol dimethylacrylate, divinyl ether, divinyl sulfite, divinyl sulfone, and mixtures thereof.
- 42. A process in accordance to claim 27 wherein the chain transfer agent is selected from the group consisting of mercaptans and halogenated hydrocarbons, and where the amount of said chain transfer agent is in the range of from about 0.01 to about 1 percent by weight, or from about 0.05 to about 0.5 percent by weight of said monomer or comonomer mixture.
- 43. A process in accordance with to claim 27 wherein the chain transfer agent is selected from the group consisting of laurylmercaptan, butylmercaptan carbon tetrachloride, carbon tetrabromide and mixtures thereof.
- 44. A developer comprised of the carrier of claim 1 and toner.
- 45. Carrier in accordance with claim 1 wherein substantially all of said pores are filled with polymer.
- 46. Carrier in accordance with claim 45 wherein the coating is comprised of a polymer mixture of a first and second polymer.
- 47. Carrier in accordance with claim 2 wherein substantially all of said core pores contain polymer (1).
- 48. A developer comprised of the carrier of claim 2 and toner.
- 49. Carrier in accordance with claim 2 wherein said number of pores containing polymer (1) is from about 70 to about 100 percent.
- 50. Carrier in accordance with claim 49 wherein each of the carrier pores contains from about 50 to about 100 percent of the polymer.
- 51. Carrier in accordance with claim 1 wherein said number of pores containing polymer (1), polymer (2), or mixtures thereof is from about 70 to about 100 percent.
- 52. Carrier consisting essentially of a hard magnetic core, the pores thereof containing polymer, and thereover a coating.
- 53. Carrier consisting essentially of a porous hard magnetic core and wherein a number of the pores thereof contain a (1) polymer, or a mixture of polymers, and which carrier contains a (2) coating thereover of a polymer, or a mixture of polymers.
- 54. Carrier consisting of a porous hard magnetic core and wherein a number of the pores thereof contain a (1) polymer, or a mixture of polymers, and which carrier contains a (2) coating thereover of a polymer, or a mixture of polymers.
- 55. A developer comprised of the carrier of claim 52 and toner.
- 56. A developer comprised of the carrier of claim 53 and toner.
- 57. A developer comprised of the carrier of claim 54 and toner.
PENDING APPLICATION
In copending application U.S. Ser. No. 09/037,555, pending entitled Carrier, filed concurrently herewith, the disclosure of which is totally incorporated herein by reference there is recited a carrier comprised of a soft or porous magnetic core, the pores thereof being filled with polymer and thereover a coating.
US Referenced Citations (24)