METHOD OF PREPARING SMALL PARTICLES OF A SOLID POLYMER

• US 3,847,886 A
• Filed: 02/21/1973
• Issued: 11/12/1974
• Est. Priority Date: 05/17/1972
• Status: Expired due to Term

• Current Assignee: Blunt H
• Original Assignee: Blunt H
• Inventors: BLUNT H
• Application Number:
  US05/334,344
• Time in Patent Office: 629 Days
• US Class Current: 528/491
• CPC Class Codes: C08J 3/16 by coagulating dispersions C08J3/122 takes precedence

Abstract

1. A METHOD OF PREPARING SPHERICAL SMALL PARTICLES OF A NORMALLY SOLID, WATER-INSOLUBLE VINYL POLYMER SELECTED FROM THE CLASS CONSISTING OF ACRYLIC POLYMERS, POLY(VINYL CHLORIDE) AND POLY(VINYL ACETATE), WHICH PROCESS COMPRISES: (A) DISSOLVING SAID POLYMER IN A WATER-IMMISCIBLE, POLAR ORGANIC SOLVENT, (B) EMULSIFYING THE RESULTANT SOLUTION IN WATER, FORMING AN OIL-IN-WATER EMULSION, (C) ADDING TO SAID OIL-IN-WATER EMULSION A WATER-IMMISCIBLE ORGANIC LIQUID WHICH IS MISCIBLE WITH THE ORGANIC SOLVENT BUT WHICH IS A NONSOLVENT FOR THE POLYMER, AND (D) RECOVERING POLYMER PARTICLES FROM THE RESULTANT MIXTURE OF LIQUIDS.

Claims

1. A METHOD OF PREPARING SPHERICAL SMALL PARTICLES OF A NORMALLY SOLID, WATER-INSOLUBLE VINYL POLYMER SELECTED FROM THE CLASS CONSISTING OF ACRYLIC POLYMERS, POLY(VINYL CHLORIDE) AND POLY(VINYL ACETATE), WHICH PROCESS COMPRISES:

(A) DISSOLVING SAID POLYMER IN A WATER-IMMISCIBLE, POLAR ORGANIC SOLVENT, (B) EMULSIFYING THE RESULTANT SOLUTION IN WATER, FORMING AN OIL-IN-WATER EMULSION, (C) ADDING TO SAID OIL-IN-WATER EMULSION A WATER-IMMISCIBLE ORGANIC LIQUID WHICH IS MISCIBLE WITH THE ORGANIC SOLVENT BUT WHICH IS A NONSOLVENT FOR THE POLYMER, AND (D) RECOVERING POLYMER PARTICLES FROM THE RESULTANT MIXTURE OF LIQUIDS.