Charge control agent combination of lecithin and pyrrolidone polymer for liquid toner and methods of use

Claim 2

Liquid toner composition for electrophotography comprising a dispersion including a carrier liquid having an electric resistance of at least 10 9 Ω cm. and a dielectric constant of not more than 3.5, a pigment or dye, a binder material selected from the group of resins, polymer binders and waxes wherein said binder is insoluble in said carrier liquid at room temperature, and a charge control agent, said charge control agent comprising lecithin and an alkylated N-vinyl pyrrolidone polymer, both said lecithin and said N-vinyl pyrrolidone polymer being soluble in said carrier liquid.

Claim 3

Liquid toner composition as recited in claim 1 wherein said N-vinyl pyrrolidone polymer comprises a C 12 -C 20 alkyl N-vinyl pyrrolidone polymer.

Claim 4

Liquid toner composition as recited in claim 1 wherein the non-volatile components are present in an amount of about 0.5-20 wt. % based on the total weight of said carrier liquid, said binder being present in an amount of from 30-99 wt. % based upon the total weight of said non-volatile components, said pigment or dye being present in an amount of from trace-50 wt. % based on the weight of said non-volatile components and wherein said charge control agent is present in an amount of from about 1×10 -4 -20 wt. % based upon the weight of said carrier liquid.

Claim 5

Liquid toner composition as recited in claim 1 wherein the weight ratio of lecithin:alkylated N-vinyl pyrrolidone polymer is from about 1:9 to 9:1.

Claim 6

Liquid toner composition as recited in claim 4 wherein the weight ratio of lecithin:alkylated N-vinyl pyrrolidone polymer is from about 3:7 to 1:9.

Claim 7

Liquid toner as recited in claim 1 wherein said carrier liquid comprises an isoparaffinic hydrocarbon fraction.

Claim 8

Liquid toner as recited in claim 4 wherein said alkylated N-vinyl pyrrolidone polymer comprises poly(vinyl pyrrolidone/1-hexadecene) homopolymer.

Claim 9

In a method of creating an image by applying an electrostatic charge to the image area of a substrate, the improvement comprising thereafter applying to said substrate a liquid toner composition comprising (i) a carrier liquid having an electric resistance of at least 10 9 Ω cm. and a dielectric constant of not more than 3.5, (ii) a color imparting pigment or dye, (iii) a binder material selected from the group consisting of resins, polymer binders, and waxes, said binder being insoluble in said carrier liquid at room temperature, and (iv) a charge control agent comprising lecithin and an alkylated N-vinyl pyrrolidone polymer, both said lecithin and said polymer being soluble in said carrier liquid.

Claim 10

In a method of creating an image by applying an electrostatic charge to the image area of a substrate, the improvement comprising thereafter applying to said substrate a liquid toner composition comprising (i) a carrier liquid having an electric resistance of at least 10 9 Ω cm. and a dielectric constant of not more than 3.5, (ii) a color imparting pigment or dye, (iii) a binder material selected from the group consisting of resins, polymer binders, and waxes, said binder being insoluble in said carrier liquid at room temperature, and (iv) a charge control agent comprising lecithin and an alkylated N-vinyl pyrrolidone polymer, both said lecithin and said polymer being soluble in said carrier liquid.

Claim 11

Method as recited in claim 8 wherein said polymer comprises a C 12 -C 20 alkyl N-vinyl pyrrolidone polymer.

Claim 12

Method as recited in claim 8 wherein the non-volatile components of said liquid toner composition are present in an amount of about 0.5-20 wt. % based on the total weight of said carrier liquid, said binder being present in an amount of from 30-99 wt. % based upon the total weight of said non-volatile components, said pigment or dye being present in an amount of from trace-50 wt. % based on the weight of said non-volatile components and wherein said charge control agent is present in an amount of from about 1×10 4 -20 wt. % based upon the weight of said carrier liquid.

Claim 13

Method as recited in claim 8 wherein the weight ratio of lecithin:alkylated N-vinyl pyrrolidone polymer is from about 1:9 to 9:1.

Claim 14

Method as recited in claim 11 wherein the weight ratio of lecithin:alkylated N-vinyl pyrrolidone polymer is from about 3:7 to 1:9.

Claim 15

Method as recited in claim 12 wherein said carrier liquid comprises an isoparaffinic hydrocarbon fraction.

Claim 16

Method as recited in claim 8 wherein said alkylated N-vinyl pyrrolidone polymer comprises poly(vinyl pyrrolidone/1-hexadecene) homopolymer.