Minute capsules having walls of siliceous material-hydroxy-containing material complex and process for their manufacture

Abstract

Abstract A PROCESS IS DISCLOSED FOR MANUFACTURING MINUTE CAPSULES, EN MASSE, WHEREIN THE CAPSULE WALLS COMPRISE A HARDENED SILICATE MATERIAL. THE PROCESS INCLUDES LIQUIDLIQUID PHASE SEPARATION OF THE WALL MATERIAL SILICATE FROM SOLUTION AS SILICIC ACID IN AN AQUEOUS CAPSUL MANUFACTURING VEHICLE BY MEANS OF A GLYCOL PHASE-SEPARATION-INDUCING MATERIAL. PREFERRED STARTING MATERIALS FOR THE PRESENT PROCESS INCLUDE ALKALI-METAL WATER GLASS AND POLYETHYLENE GLYCOL, THE PRESENT LIQUID-LIQUID PHASE SEPARATION CAN BE CONSIDERED TO BE SIMILAR TO SO-CALLED "COMPLEX COACERVATION" OF THE PRIOR ART IN THAT A COMPLEX OF TWO POLYMERIC MATERIALS ARE CONCENTRATED IN THE EMERGENT LIQUID PHASE. THE CAPSULE WALLS ARE SOLIDIFIED BY REACTING THE SILCEOUS CAPSULE WALL MATERIAL WITH AN INORGANIC SALT, VIZ, ALUMINUM SULFATE, CALCIUM CHLORIDE, MAGNESIUM SULFATE, IRON CHLORIDE OR MAGNESIUM BROMIDE.

Inventors

• 👤 G Fanger

Bibliographic Details