Prodn. of porous articles from water-in-oil emulsions contg. monomers - by catalytic hardening under microwave heating

摘要

Aq. emulsions of monomers contg. 10-90% water, >=1 catalyst effective at below the b. pt. of the compsn., and opt. accelerators, inhibitors, plasticisers, crosslinking and crosslinkable materials, fillers and dyes, are cast to the required shape and polymerised by heating with microwaves of 1-300 mm. wavelength and 1-300 GHz frequency, opt. with additional irradiation. Used in continuous prodn. of sheets, strips, profiles etc. and mass prodn. of porous products from multicavity moulds. Moulding times are reduced by up to 95% with complete polymerisation in 30-60 s. or less. Compsns. with adequate pot life can be used. Energy consumption is small. Parts with heavy wall sections can be moulded in 2-4 mins. By using layers of foaming and non-foaming compsns., sandwich construction can be made.