PREPARATING FIRE RETARDANT ORGANO SILOXANE FOAM AND FOAM PREPARED THEREFROM

摘要

1522637 Fire retardant organo siloxane foams DOW CORNING CORP 10 Oct 1975 [30 Oct 1974] 41607/75 Heading C3C and C3T A fire retardant organosiloxane foam is made by mixing at ambient temperature (1) an organo-hydrogensiloxane having an average of at least 3 silicon-bonded hydrogen atoms/ molecule, an average of no more than 1 siliconbonded hydrogen atom/silicon atom and an organic radical which is C1-6 alkyl, phenyl or 3,3,3-trifluoropropyl, (2) a hydroxylated organosiloxane having an average of 1À0-2À5 siliconbonded hydroxyl radicals/molecule and having an average of at least one organic radical (as defined in (1) above)/silicon atom, and (3) 5-200 parts by wt. of a catalyst to foam and cure the organosiloxane which is platinum or a compound thereof/one million parts by wt. of total composition, (1) and (2) being present in amounts sufficient to provide a molar ratio of silicon-bonded hydrogen atoms to siliconbonded hydroxyl radicals of 2À5-40. The mixture having a viscosity of less than 100,000 cs. at 25‹ C., and allowing a foam to form. The above molar ratio may be 0À5-40 when a benzene-soluble vinyl containing triorganosiloxy end blocked polydiorganosiloxane is present in the above composition. In the examples foams were made from mixtures of phenylmethylvinylsiloxy end blocked polydimethylsiloxane, trimethylsiloxy end blocked polymethylhydrogensiloxane (optionally containing dimethylsiloxane) hydroxyl end blocked poly dimethylsiloxane, polymethylvinylsiloxane cyclics and/or diphenylmethyl-silanol and optionally zinc oxide, carbon black, quartz 3- methyl-1-butyne-3-ol and/or calcium carbonate using as catalyst a chloroplatinic acid complex with sym. divinyltetramethyldisoloxane.