Process for preparing colored toner particles

• US 20050244738A1
• Filed: 04/30/2004
• Published: 11/03/2005
• Est. Priority Date: 04/30/2004
• Status: Active Grant

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Tyagi, Dinesh, Johnston, Bret Martin, Yoon, Hichang, Regan, Michael Thomas
• Granted Patent: US 7,169,528 B2
• Time in Patent Office: Days
• US Class Current: 430/137.100
• CPC Class Codes: G03G 9/08706 Polymers of alkenyl-aromatic compounds
• CPC Class Codes: G03G 9/08711 with esters of acrylic or methacrylic acid
• CPC Class Codes: G03G 9/08755 Polyesters

Abstract

A process for the preparation of colored polymeric toner particles includes: forming an organic phase by dissolving an organic polymer and, optionally, one or more additives in a water-immiscible organic solvent; forming a dispersion by combining the organic phase with an aqueous phase comprising a particulate stabilizer, a colorant, and, optionally, a promoter, with the proviso that when the colorant is carbon black, it is an acidic carbon black having a pH less than 7; homogenizing the dispersion to form droplets containing the organic solvent, organic polymer, and colorant; removing the organic solvent from the droplets to form colored polymeric toner particles; and separating and drying the toner particles.

Claims

1. A process for the preparation of colored polymeric toner particles comprising:

a) forming an organic phase by dissolving an organic polymer and, optionally, one or more additives in a water-immiscible organic solvent;

b) forming a dispersion by combining the organic phase with an aqueous phase comprising a particulate stabilizer, a colorant, and, optionally, a promoter, with the proviso that when the colorant is carbon black, said carbon black is an acidic carbon black having a pH less than 7;

c) homogenizing the dispersion, thereby forming droplets containing the organic solvent, organic polymer, and colorant;

d) removing the organic solvent from the droplets, thereby forming colored polymeric toner particles; and

e) separating and drying the colored polymeric toner particles.

2. The process of claim 1 wherein said organic polymer is a vinyl polymer or copolymer.

3. The process of claim 2 wherein said organic polymer is a styrene-acrylic copolymer.

4. The process of claim 1 wherein said organic polymer is a monomer condensation copolymer.

5. The process of claim 4 wherein said organic polymer is a polyester.

6. The process of claim 1 wherein said additive is a charge control agent, a wax, or a lubricant.

7. The process of claim 6 wherein said additive is a charge control agent, the amount of said charge control agent being about 0.1-5 wt. % based on the weight of said toner particles.

8. The process of claim 1 wherein said water-immiscible organic solvent is selected from the group consisting of dichloromethane, ethyl acetate, propyl acetate, methyl ethyl ketone, trichloromethane, carbon tetrachloride, ethylene chloride, trichloroethane, toluene, xylene, cyclohexanone, and 2-nitropropane.

9. The process of claim 8 wherein said water-immiscible organic solvent is selected from the group consisting of dichloromethane, ethyl acetate, and propyl acetate.

10. The process of claim 1 wherein said particulate stabilizer is a crosslinked latex polymer or an inorganic oxide.

11. The process of claim 10 wherein said particulate stabilizer is colloidal silica.

12. The process of claim 1 wherein said promoter is selected from the group consisting of sulfonated polystyrenes, alginates, carboxymethyl cellulose, methoxycellulose, gelatin, glue, casein, albumin, gluten, tetramethylammonium hydroxide, tetramethylammonium chloride, diethylaminoethylmethacrylate, water-soluble resinous amine-dicarboxylic acid condensation products, such as the products of diethanol amine and adipic acid, and water-soluble condensation products of ethylene oxide, urea and formaldehyde and polyethyleneimine.

13. The process of claim 12 wherein said promoter is poly(adipic acid-co-methylaminoethanol).

14. The process of claim 1 wherein said promoter is present in an amount of about 0.2 parts to about 0.6 parts per 100 parts of said aqueous phase.

15. The process of claim 1 wherein said colorant is a pigment or a dye.

16. The process of claim 1 wherein said colorant is in the form of a dry powder.

17. The process of claim 1 wherein said colorant is in the form of an aqueous dispersion.

18. The process of claim 1 wherein said colorant is in the form of a wet cake.

19. The process of claim 1 wherein said colorant is present in an amount of about 1 wt. % to about 30 wt. % based on the weight of said toner particles.

20. The process of claim 19 wherein said colorant is present in an amount of about 2 wt. % to about 15 wt. % based on the weight of said toner particles.