METHOD FOR MANUFACTURING POROUS PARTICLES WITH NON-POROUS SHELL

• US 20090098288A1
• Filed: 10/11/2007
• Published: 04/16/2009
• Est. Priority Date: 10/11/2007
• Status: Active Grant

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Nair, Mridula, Jones, Tamara K., Massa, Dennis J., Hamilton, Dale E.
• Granted Patent: US 8,940,362 B2
• Time in Patent Office: Days
• US Class Current: 427/212
• CPC Class Codes: C08J 2201/05 Elimination by evaporation or heat degradation of a liquid phase
• CPC Class Codes: C08J 2201/0502 the liquid phase being organic
• CPC Class Codes: C08J 2201/0504 the liquid phase being aqueous
• CPC Class Codes: C08J 3/16 by coagulating dispersions C08J3/122 takes precedence
• CPC Class Codes: C08J 9/28 by elimination of a liquid phase from a macromolecular composition or article, e.g. drying of coagulum

Abstract

The present invention is core-shell polymer particles comprising a common binder polymer for the core and the shell wherein the core has a porosity and the shell is non-porous The particles have a porosity from 10 to 70 percent.

Claims

1. A method of manufacturing porous core-shell polymer particles having a nonporous shell comprising:

providing a first organic solvent containing a dissolved polymer;

dispersing the organic solvent in an aqueous phase containing a stabilizer to form an emulsion;

adding the emulsion to a second organic solvent wherein the second organic solvent is miscible with water and the first organic solvent, and a non-solvent for the polymer; and

evaporating the first and second organic solvents from the emulsion to form core-shell polymer particles.

2. The method of claim 1 further comprising:

isolating the core-shell polymer particles.

3. The method of claim 2 further comprising:

drying the core-shell polymer particles.

4. The method of claim 1 wherein the polymer is formed from vinyl monomers, condensation monomers, condensation esters and mixtures thereof.

5. The method of claim 1 wherein the polymer is selected from the group consisting of polyesters;

polymers of styrenes, monoolefins, vinyl esters, vinyl chloride, methylene aliphatic monocarboxylic acid esters, vinyl ethers and vinyl ketones.

7. The method of claim 1 wherein the first organic solvent further contains colorants, waxes and charge control agents.

8. The method of claim 1 wherein the stabilizer comprises poylvinylpyrrolidone, polyvinylalchol, colloidal silica or latex particles.

9. The method of claim 1 wherein the first organic solvent comprises ethyl acetate, propyl acetate, chloromethane, dichloromethane, richloromethane, carbon tetrachloride, ethylene chloride, trichloroethane, toluene, xylene, cyclohexanone, cyclohexane and 2-nitropropane.

10. The method of claim 1 wherein second organic solvent comprises methanol, ethanol, butanol, isopropanol and propanol.