GB1399344A — Method of producing vesiculated particles of inorganic materials

USPTO Abstract

1399344 Vesicular microspheres of inorganic materials IMPERIAL CHEMICAL INDUSTRIES Ltd 19 May 1972 [3 June 1971] 18837/71 Heading C1A [Also in Division B1] Vesicular microspheres of inorganic materials containing vesicules having a diameter of less than 20Á and which occupy 5-95% of the total sphere volume and which have a particle size of 1-100Á, are prepared by forming a first emulsion consisting of (as the continuous phase) a soln. of an inorganic precursor in a solvent, and (as the disperse phase) a liquid immiscible with the soln.; forming a second emulsion consisting of (as the disperse phase) the first emulsion and (as the continuous phase) a liquid immiscible with the disperse phase; converting the second emulsion into a particulate suspension of the inorganic material and finally separating the particles from the liquid continuous phase. The inorganic precursor may be a silicate of an alkali metal, quaternary ammonium, or a metal, e.g. Al, Fe, Cr or Mn, or an organic silicate, e.g. quanidine silicate or ethyl silicate, or aluminium chloro-phosphate ethanolate. The second emulsion may be converted into the particulate suspension by: (a) heating the emulsion to a temp. between the b.pt. of the solvent and the non-miscible liquid, thereby liberating the solvent (having the higher b.pt.) and then heating to a higher temp. to convert the precursor into the inorganic material; (b) cooling the emulsion to a temp. between the b.pt. of the solvent and the non- miscible liquid, thereby freezing out the ptles. with the solvent (having a higher f.pt.) and then heating the ptles.; or (c) reacting the inorganic precursor with another chemical compound which may be present either in the continuous phase or the first emulsion or prevent in the second emulsion. The liquids used may be aliphatic or aromatic hydrocarbons, esters, ketones, ethers, alcohols or water. The non- miscible liquid in the first emulsion may be a polymerizable monomer containing dispersed or dissolved particles of pigment, fungicide, insecticide blowing agent or polymeric material. An emulsifying agent may be used.