Liquid developer compositions

Abstract

A liquid developer comprised of thermoplastic resin particles, and a charge director comprised of an ammonium AB diblock copolymer of the formula ##STR1## wherein X - is a conjugate base or anion of a strong acid, R is hydrogen or alkyl, R' is alkyl, R" is an alkyl group containing from about 6 to about 20 carbon atoms, and y and x represent the number average degree of polymerization (DP) wherein the ratio of y to x is in the range of from about 10 to 2 to about 100 to 20.

What is claimed is: 
     
       1. A liquid developer comprised of thermoplastic resin particles, and a charge director comprised of an ammonium AB diblock copolymer of the formula ##STR4## wherein X -  is a conjugate base or anion of a strong acid, R is hydrogen or alkyl, R' is alkyl, R" is an alkyl group containing from about 6 to about 20 carbon atoms, and y and x represent the number average degree of polymerization (DP) wherein the ratio of y to x is in the range of from about 10 to 2 to about 100 to 20. 
     
     
       2. A liquid developer comprised of a liquid component, thermoplastic resin, and a charge director comprised of (1) a protonated AB diblock copolymer of poly[2-dimethylammoniumethyl methacrylate bromide co-2-ethylhexyl methacrylate], poly[2-dimethylammoniumethyl methacrylate tosylate co-2-ethylhexyl methacrylate], poly[2-dimethylammoniumethyl methacrylate chloride co-2-ethylhexyl methacrylate], poly[2-dimethylammoniumethyl methacrylate bromide co-2-ethylhexyl acrylate], poly[2-dimethylammoniumethyl acrylate bromide co-2-ethylhexyl methacrylate], poly[2-dimethylammoniumethyl acrylate bromide co-2-ethylhexyl acrylate], poly[2-dimethylammoniumethyl methacrylate tosylate co-2-ethylhexyl acrylate], poly[2-dimethylammoniumethyl acrylate tosylate co-2-ethylhexyl acrylate], poly[2-dimethylammoniumethyl methacrylate chloride co-2-ethylhexyl acrylate], poly[2-dimethylammoniumethyl acrylate chloride co-2-ethylhexyl acrylate], poly[2-dimethylammoniumethyl methacrylate bromide co-N,N-dibutyl methacrylamide], poly[2-dimethylammoniumethyl methacrylate tosylate co-N,N-dibutyl methacrylamide], poly[2-dimethylammoniumethyl methacrylate bromide co-N,N-dibutylacrylamide], or poly[2-dimethylammoniumethyl methacrylate tosylate co-N,N-dibutylacrylamide], and an optional charge adjuvant. 
     
     
       3. A liquid electrostatographic developer comprised of (A) a liquid with a viscosity of from about 0.5 to about 20 centipoise and resistivity greater than or equal to 5×10 9  ; (B) thermoplastic resin particles with an average volume particle diameter of from about 0.1 to about 30 microns; (C) a charge director comprised of a protonated AB diblock copolymer of the formula ##STR5## wherein X -  is a conjugate base or anion of a strong acid, R is hydrogen or alkyl, R' is alkyl, R" is an alkyl group containing from about 6 to about 20 carbon atoms, and y and x represent the number average degree of polymerization (DP) wherein the ratio of y to x is in the range of from about 10 to 2 to about 100 to 20; and (D) an optional charge adjuvant. 
     
     
       4. A developer in accordance with claim 1 wherein the charge director is comprised of a protonated AB diblock copolymer of poly[2-dimethylammoniumethyl methacrylate bromide co-2-ethylhexyl methacrylate], poly[2-dimethylammoniumethyl methacrylate tosylate co-2-ethylhexyl methacrylate], poly[2-dimethylammoniumethyl methacrylate chloride co-2-ethylhexyl methacrylate], poly[2-dimethylammoniumethyl methacrylate bromide co-2-ethylhexyl acrylate], poly[2-dimethylammoniumethyl acrylate bromide co-2-ethylhexyl methacrylate], poly[2-dimethylammoniumethyl acrylate bromide co-2-ethylhexyl acrylate], poly[2-dimethylammoniumethyl methacrylate tosylate co-2-ethylhexyl acrylate], poly[2-dimethylammoniumethyl acrylate tosylate co-2-ethylhexyl acrylate], poly[2-dimethylammoniumethyl methacrylate chloride co-2-ethylhexyl acrylate], poly[2-dimethylammoniumethyl acrylate chloride co 2-ethylhexyl acrylate], poly[2-dimethylammoniumethyl methacrylate bromide co-N,N-dibutyl methacrylamide], poly[2-dimethylammoniumethyl methacrylate tosylate co-N,N-dibutyl methacrylamide], poly[2-dimethylammoniumethyl methacrylate bromide co-N,N-dibutylacrylamide], poly[2-dimethylammoniumethyl methacrylate tosylate co-N,N-dibutylacrylamide], or mixtures thereof. 
     
     
       5. A developer in accordance with claim 1 wherein the resin is a copolymer of ethylene and an α, β ethylenically unsaturated acid selected from the group consisting of acrylic acid and methacrylic acid; a copolymer of ethylene acrylic or methacrylic acid, alkylester of acrylic or methacrylic acid; or a copolymer of ethylene and methacrylic acid with a melt index at 90° C. of 500. 
     
     
       6. A developer in accordance with claim 2 wherein the resin is a copolymer of ethylene and an α, β ethylenically unsaturated acid selected from the group consisting of acrylic acid and methacrylic acid; a copolymer of ethylene acrylic or methacrylic acid, alkylester of acrylic or methacrylic acid; or a copolymer of ethylene and methacrylic acid with a melt index at 190° C. of 500. 
     
     
       7. An electrostatic developer in accordance with claim 1 containing a colorant, pigment, or dye. 
     
     
       8. An electrostatic developer in accordance with claim 7 wherein the colorant is present to about 60 percent by weight based on the total weight of the developer solids. 
     
     
       9. An electrostatic developer in accordance with claim 2 containing a colorant, pigment, or dye. 
     
     
       10. A developer in accordance with claim 9 wherein the pigment is black, cyan, magenta, yellow, or mixtures thereof. 
     
     
       11. A developer in accordance with claim 10 wherein the pigment is carbon black. 
     
     
       12. A developer in accordance with claim 1 wherein the charge director is present in an amount of from about 0.1 to about 10 weight percent based on the weight of the developer solids and there is enabled a negatively charged toner. 
     
     
       13. A developer in accordance with claim 3 wherein component (A) is present in an amount of from about 85 percent to about 99.9 percent by weight, based on the total weight of the liquid developer, the total weight of developer solids is from about 0.1 percent to about 15 percent by weight, and component (C) is present in an amount of from about 0.25 to about 1,500 milligrams/gram developer solids. 
     
     
       14. A developer in accordance with claim 3 wherein component (D) is present in an amount of from about 0.1 to about 15 percent by weight based on the total weight of developer solids. 
     
     
       15. A developer in accordance with claim 3 further containing a charge adjuvant selected from the group consisting of polyhydroxy compounds which contain at least 2 hydroxy groups, amino alcohol, polybutylene succinimide and metallic soaps. 
     
     
       16. A developer in accordance with claim 1 wherein the liquid is an aliphatic hydrocarbon. 
     
     
       17. A developer in accordance with claim 2 wherein the liquid is an aliphatic hydrocarbon. 
     
     
       18. A developer in accordance with claim 16 wherein the aliphatic hydrocarbon is a mixture of branched hydrocarbons of from about 12 to about 20 carbons atoms. 
     
     
       19. A developer in accordance with claim 17 wherein the aliphatic hydrocarbon is a mixture of branched hydrocarbons of from about 12 to about 20 carbons atoms. 
     
     
       20. A developer in accordance with claim 16 wherein the aliphatic hydrocarbon is a mixture of normal hydrocarbons of from about 10 to about 20 carbon atoms. 
     
     
       21. A developer in accordance with claim 17 wherein the aliphatic hydrocarbon is a mixture of normal hydrocarbons of from about 10 to about 16 carbon atoms. 
     
     
       22. A developer in accordance with claim 1 wherein the resin is an alkylene polymer, a styrene polymer, an acrylate polymer, a polyester, or mixtures thereof. 
     
     
       23. A developer in accordance with claim 2 wherein the resin is an alkylene polymer, a styrene polymer, an acrylate polymer, a polyester, or mixtures thereof. 
     
     
       24. A developer in accordance with claim 3 wherein the resin is an alkylene polymer, a styrene polymer, an acrylate polymer, a polyester, or mixtures thereof. 
     
     
       25. An imaging method which comprises forming an electrostatic latent image followed by the development thereof with the liquid developer of claim 1. 
     
     
       26. A liquid developer comprised of a liquid component, thermoplastic resin, and a charge director comprised of an ammonium protonated AB diblock copolymer. 
     
     
       27. A liquid electrostatographic developer comprised of (A) a liquid having viscosity of from about 0.5 to about 20 centipoise and resistivity greater than 5×10 9  ; (B) thermoplastic resin particles with an average volume particle diameter of from about 0.1 to about 30 microns; (C) a charge director comprised of a protonated AB diblock copolymer; and optionally (D) a charge adjuvant. 
     
     
       28. A developer in accordance with claim 2 wherein there is selected a mixture of said charge directors. 
     
     
       29. A liquid electrostatographic developer in accordance with claim 1 with two of said AB diblock copolymers with from about 0.1 to about 99.9 weight percent of one polymer and from about 0.1 to about 99.9 weight percent of a second polymer. 
     
     
       30. A developer in accordance with claim 1 wherein R is alkyl with from 1 to about 25 carbon atoms. 
     
     
       31. A developer in accordance with claim 30 wherein alkyl is methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl or decyl. 
     
     
       32. A developer in accordance with claim 1 wherein R" contains about 6 to about 12 carbon atoms.