×

Polymer coated pigment particles and a process for their preparation

  • US 3,897,586 A
  • Filed: 08/04/1972
  • Issued: 07/29/1975
  • Est. Priority Date: 08/05/1970
  • Status: Expired due to Term
First Claim
Patent Images

1. A PROCESS FOR PREPARING POLYMER-COATED FINELY DIVIDED INORGANIC PARTICLES WHICH COMPRISES SUSPENDING FINELY DIVIDED HYDROPHILIC INORGANIC PARTICLES SELECTED FROM THE GROUP CONSISTING OF METAL OXIDES, CLAY, COLLOIDAL SILICA, AND ZINC CHROMATE IN A NON-AQUEOUS LIQUID REACTION MEDIUM SELECTED FROM THE GROUP CONSISTING OF ALUPHATIC HYDROCARBONS AND CYCLOHEXANE WITHOUT THE PRESENCE OF A SURFACE-ACTIVE AGENT, ADDING POLYMERIZABLE ETHYLENICALLY UNSATURATED MONOMER SELECTED FROM THE GROUP CONSISTING OF ACRYLIC ESTERS, METHACRYLIC ESTERS, VINYL ESTERS, VINYL HALIDES, VINYLIDENE HALIDES, ACRYLIC ACID, AND METHACRYLIC ACID AND A FREE-RADICAL INITIATOR TO THE MEDIUM AT A RATE WHICH APPROXIMATES THE RATE OF POLYMERIZATION, AND POLYMERIZING THE MONOMER IN SITU ONTO THE PARTICLES UNTIL A POLYMER LOADING OF AT LEAST ABOUT 0.5 WEIGHT PERCENT IS REACHED, SAID LIQUID REACTION MEDIUM BEING A SOLVENT FOR THE MONOMER AND INITIATOR AND A NON-SOLVENT FOR THE POLYMER FORMED AS A COATING ON THE PARTICLES.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×