Carbon based black toners prepared via limited coalescence process

• US 8,546,057 B2
• Filed: 01/31/2011
• Issued: 10/01/2013
• Est. Priority Date: 01/31/2011
• Status: Expired due to Fees

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Tyagi, Dinesh, Granica, Louise
• Primary Examiner(s): RODEE, CHRISTOPHER D
• Application Number:
  US13/017,384
• Publication Number:
  US 20120196221A1
• Time in Patent Office: 974 Days
• Field of Search: 430/137.1, 430/137.14
• US Class Current: 430/137.1
• CPC Class Codes: G03G 9/0804 whereby the components are brought together in a liquid dispersing medium
• CPC Class Codes: G03G 9/0819 characterised by the dimensions of the particles
• CPC Class Codes: G03G 9/08702 comprising macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: G03G 9/08755 Polyesters
• CPC Class Codes: G03G 9/08791 characterised by the presence of specified groups or side chains
• CPC Class Codes: G03G 9/08795 characterised by their chemical properties, e.g. acidity, molecular weight, sensitivity to reactants
• CPC Class Codes: G03G 9/08797 characterised by their physical properties, e.g. viscosity, solubility, melting temperature, softening temperature, glass transition temperature
• CPC Class Codes: G03G 9/0904 Carbon black

Abstract

A black toner composition comprising toner particles prepared by a chemical process of manufacture comprising carbon black pigment, a first addition polymer comprising carboxylic acid groups along the polymer backbone, and a thermoplastic second polymer binder distinct from the first polymer, wherein the first polymer has an Acid Value of from 30 to 220 and is present at a weight ratio of greater than 1:2 relative to the amount of carbon, and at a relatively lower weight percent than the second polymer. A process for preparation of such toner particles comprising: preparing a masterbatch comprising a carbon black and a first addition polymer comprising carboxylic acid groups along the polymer backbone and having an Acid Value of from 30 to 220, where the first polymer is present at a weight ratio of greater than 1:2 relative to the amount of carbon; dissolving a thermoplastic second polymer binder in an organic solvent; adding the masterbatch to the solution of second polymer binder to form an organic phase, wherein the first polymer is present at a lower weight percent than the second polymer; dispersing the organic phase in an aqueous phase comprising a particulate stabilizer to form a dispersion; and removing the solvent from the organic phase to form toner particles comprising the first polymer, the second polymer binder and carbon black.

Claims

1. A process for preparation of toner particles comprising carbon black and polymeric binder, comprising:

preparing a masterbatch comprising carbon black particles and a first addition polymer comprising carboxylic acid groups along the polymer backbone and having an Acid Value of from 50-200, where the first addition polymer is present at a weight ratio of greater than 1;

2 relative to the amount of carbon;

dissolving a thermoplastic second polymer binder in an organic solvent;

adding the masterbatch to the solution of second polymer binder to form an organic phase, wherein the first addition polymer is present at a lower weight percent than the second polymer;

dispersing the organic phase in an aqueous phase comprising a particulate stabilizer to form a dispersion; and

removing the solvent from the organic phase to form toner particles comprising the first addition polymer, the second polymer binder, and carbon black.

2. A process according to claim 1, wherein the first addition polymer is present at a weight ratio of up to 4:

1 relative to the amount of carbon.

3. A process according to claim 1, wherein the first addition polymer is present at a weight ratio of from 1:

1 to 3;

1 relative to the amount of carbon.

4. A process according to claim 1, wherein the first addition polymer is present at a weight ratio of from 1:

1 to 2;

1 relative to the amount of carbon.

5. A process according to claim 1, wherein the first addition polymer has a weight average molecular weight Mw of from 3,000-20,000.

6. A process according to claim 1, wherein the first addition polymer has a weight average molecular weight Mw of from 4,000-10,000.

7. A process according to claim 1, wherein the formed toner particles have a mean volume-average diameter of less than about 8 μ

m, and include 1 wt. % to 20 wt. % carbon pigment.

8. A process according to claim 1, wherein the formed toner particles have a mean volume-average diameter of from 3 μ

m to 7 μ

m, and include 3 wt. % to 10 wt. % of carbon pigment.

9. A process according to claim 1, wherein the second polymer binder comprises a polyester.

10. A process for preparation of toner particles comprising carbon black and polymeric binder, comprising:

preparing a masterbatch comprising carbon black particles and a first addition polymer comprising carboxylic acid groups along the polymer backbone and having an Acid Value of from 50-150, where the first addition polymer is present at a weight ratio of greater than 1;

2 relative to the amount of carbon;

dissolving a thermoplastic second polymer binder in an organic solvent;

adding the masterbatch to the solution of second polymer binder to form an organic phase, wherein the first addition polymer is present at a lower weight percent than the second polymer;

dispersing the organic phase in an aqueous phase comprising a particulate stabilizer to form a dispersion; and

removing the solvent from the organic phase to form toner particles comprising the first addition polymer, the second polymer binder, and carbon black.