SILICONE WAX-CONTAINING TONER PARTICLES WITH CONTROLLED MORPHOLOGY

• US 20090017396A1
• Filed: 07/13/2007
• Published: 01/15/2009
• Est. Priority Date: 07/13/2007
• Status: Active Grant

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Yang, Xiqiang, Tyagi, Dinesh
• Granted Patent: US 7,687,218 B2
• Time in Patent Office: Days
• US Class Current: 430/137.140
• CPC Class Codes: G03G 9/0804 whereby the components are brought together in a liquid dispersing medium
• CPC Class Codes: G03G 9/0827 characterised by their shape, e.g. degree of sphericity
• CPC Class Codes: G03G 9/08702 comprising macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: G03G 9/08782 Waxes
• CPC Class Codes: G03G 9/0902 Inorganic compounds
• CPC Class Codes: G03G 9/0904 Carbon black
• CPC Class Codes: G03G 9/0918 Phthalocyanine dyes

Abstract

The present invention is a method for the preparation of electrostatographic toner including the following steps. A first dispersion is prepared with a solvent, a silicone wax, and a hyperdispersant. The first dispersion is added to an organic solvent containing a polymer material to form an organic phase. The organic phase is dispersed in an aqueous phase containing a particulate stabilizer to form a second dispersion. The second dispersion is homogenized. The organic solvent is evaporated from the second dispersion and the resultant product is recovered, washed and dried. In an alternate method the hyperdispersant is added directly to the organic phase before mixing with the aqueous phase.

Claims

1. A method for the preparation of electrostatographic toner comprising the steps of:

a) combining a solvent, a dispersing agent, and a silicone wax to form a dispersion;

b) mixing the dispersion with a polymer material to form an organic phase;

c) dispersing the organic phase in an aqueous phase comprising a particulate stabilizer and homogenizing the resultant mixture;

d) evaporating the solvent; and

e) washing and drying the resultant product.

2. The method of claim 1 wherein a charge control agent is added in step b).

3. The method of claim 1 wherein a pigment is added in step b).

4. The method of claim 1 wherein a promoter is added in step c).

5. The method of claim 1 wherein the solvent is selected from chloromethane, dichloromethane, ethyl acetate, n-propyl acetate, iso-propyl acetate, vinyl chloride, methyl ethyl ketone, trichloromethane, carbon tetrachloride, ethylene chloride, trichloroethane, toluene, xylene, cyclohexanone and 2-nitropropane.

6. The method of claim 1 wherein the solvent is ethyl acetate.

7. The method of claim 1 wherein the particulate stabilizer is selected from the group consisting of highly cross-linked latex polymeric material, and SiO₂.

8. The method of claim 1 wherein the amount of particulate stabilizer is between 1 to 15 parts based on 100 parts of total solids in the toner.

9. The method of claim 1 wherein the relationship between the aqueous phase and the organic phase, by volume, ranges from 1:

1 to 9;

1.

10. The method of claim 1 wherein the amount of wax used is greater than 4 weight percent based on the total weight of the electrophotographic toner.

11. The method of claim 1 wherein the silicone wax is selected from the group consisting of Dow Corning AMS-C30 and Dow Corning 2-5088.

12. The method of claim 1 wherein the polymer material is selected from, olefin homopolymers and copolymers, such as, polyethylene, polypropylene, polyisobutylene and polyisopentylene;

polytrifluoroolefins, such as polytetrafluoroethylene and polytrifluorochloroethylene;

polyamides, such as polyhexamethylene adipamide, polyhexamethylene sebacamide, and polycaprolactam;

acrylic resins, such as polymethylmethacrylate, polymethylacrylate, polyethylmethacrylate and styrene-methylmethacrylate;

ethylene-methylacrylate copolymers, ethylene-ethyl acrylate copolymers, ethylene-ethyl methacrylate copolymers, polystyrene and copolymers of styrene with unsaturated monomers, cellulose derivatives, polyesters, polyvinyl resins and ethylene-allyl alcohol copolymers.

13. The method of claim 3 wherein a pigment is selected from the group consisting of TiO₂;

carbon black such as channel black, furnace black, acetylene black, thermal black, lamp black and aniline black;

phthalocyanine pigments such as copper phthalocyanine, mono-chlor copper phthalocyanine, and hexadecachlor copper phthalocyanine;

organic pigments such as anthraquinone vat pigments such as vat yellow 6GLCL1127, quinone yellow 18-1, indanthrone CL1106, pyranthrone CL1096, brominated pyranthrones such as dibromopyranthrone, vat brilliant orange RK, anthramide brown CL1151, dibenzanthrone green CL1101, flavanthrone yellow CL1118;

azo pigments such as toluidine red C169 and hansa yellow; and

metallized pigments such as azo yellow and permanent red.

14. The method of claim 3 wherein the pigment is selected from bridged aluminum phthalocyanine and carbon black.

15. A method for the preparation of electrostatographic toner comprising the steps of:

a) combining a solvent, and a silicone wax to form a dispersion;

b) mixing the dispersion with a polymer material and a hyperdispersant to form an organic phase;

c) dispersing the organic phase in an aqueous phase comprising a particulate stabilizer and homogenizing the resultant mixture;

d) evaporating the solvent; and

e) washing and drying the resultant product.

16. The method of claim 15 wherein the solvent is selected from chloromethane, dichloromethane, ethyl acetate, n-propyl acetate, iso-propyl acetate, vinyl chloride, methyl ethyl ketone, trichloromethane, carbon tetrachloride, ethylene chloride, trichloroethane, toluene, xylene, cyclohexanone and 2-nitropropane.

17. The method of claim 15 wherein the particulate stabilizer is selected from the group consisting of highly cross-linked latex polymeric material, and SiO₂.

18. The method of claim 15 wherein the silicone wax is selected from the group consisting of Dow Corning AMS-C30 and Dow Corning 2-5088.

19. The method of claim 15 wherein the polymer material is selected from, olefin homopolymers and copolymers, such as, polyethylene, polypropylene, polyisobutylene and polyisopentylene;

polytrifluoroolefins, such as polytetrafluoroethylene and polytrifluorochloroethylene;

polyamides, such as polyhexamethylene adipamide, polyhexamethylene sebacamide, and polycaprolactam;

acrylic resins, such as polymethylmethacrylate, polymethylacrylate, polyethylmethacrylate and styrene-methylmethacrylate;

ethylene-methylacrylate copolymers, ethylene-ethyl acrylate copolymers, ethylene-ethyl methacrylate copolymers, polystyrene and copolymers of styrene with unsaturated monomers, cellulose derivatives, polyesters, polyvinyl resins and ethylene-allyl alcohol copolymers.