| abstract |
1,253,608. Coated fabrics. STAUFFERWACKER SILICONE CORP. 4 Dec., 1969 [5 Dec., 1968], No. 59357/69. Heading B2E. [Also in Division C3] Unprimed fabrics, e.g. cotton, wool, asbestos, nylon or especially glass fibres are coated with an organopolysiloxane composition comprising: (I) an organopolysiloxane having a viscosity of 100,000-750,000 centistokes at 25 C, (II) a second hydroxyl terminated organopolysiloxane, present at 2-10% by wt. of I, having a viscosity of 40-100 centistokes at 25C, (III) a curing agent and (IV) sufficient filler to provide an uncured composition having a penetrometer value of 250-350 as measured by the ASTM D 217-65T procedure. I may have the formula (RR'SiO) x in which R and R' are independently alkyl, alkenyl, aryl or a halo- or cyano-substituted organic radicals. I may contain 0.05-0.35 mole % of vinyl groups, e.g. methylvinyl groups. II may be a dimethylpolysiloxane IV, e.g. silica and/or titania may be present at 10-100% by wt. of I. The composition may additionally contain a blowing agent, e.g. ammonium carbonate. The composition may be cured by heating, e.g. >110C for at least 3 minutes, preferably followed by a post-cure at up to 250C. |