fadenformige structure by type of mikrokapseln and procedures for their production

摘要

1392508 Cored filaments SNAM PROGETTI SpA and PROTEZIONE RICERCA INDUSTRIALE SA 24 April 1972 [22 April 1971] 18963/72 Heading B8C A filamentary product, comprising a hollow filament having a diameter not greater than 100Á and comprising a core containing an active substance which is released when the filament wall is ruptured, is made by conventional concentric spinning methods using fluid core and sleeve materials. Preferably both are liquids and the sleeve material is one which may be solidified by passage through a chemical hardening bath, e.g. cellulose acetate or xanthate, or polyacrylamide. Alternatively, the sleeve material may be a thermoplastic, e.g. polyethylene. The core may be placed centrally or eccentrically and may be a liquid such as a solution of an adhesive (e.g. a CS 2 solution of polyisobutylene) or an enzyme (e.g. invertase in aqueous glycerol), an aqueous suspension of an insoluble particulate material or a liquifiable solid, e.g. stearic acid. Preferably, the viscosities of the liquid core and sleeve materials are approximately equal, that of the core material being adjusted if necessary.