GB1409476A - Silicone fluid compositions - Google Patents

Abstract

1409476 Silicone fluid composition TORAY INDUSTRIES Inc 27 July 1973 35801/73 Heading C3T A silicone fluid composition not containing free water and comprising a thermally resistant polyorganosiloxane having a vsicosity of from 50-10,000 cs at 25‹ C. and precipitated silica containing constitution water in an amount which extends the gel time. The amount of precipitated silica is preferably from 0À1-30% wt. based on the silicone fluid. The silicone fluid is preferably a polyorganosiloxane having the unit formula RnSiO (4-n)/2 where n = 1À1-2À9, and R is an alkyl, cycloalkyl, aralkyl, aryl or alkaryl radical or a halogenated derivative thereof, or a cyanoalkyl radical or a radical containing ether, carboxylate, or ester groups, and may have a M.Wt. of from 200-100,000. Optional ingredients include fumed silica and carboxylic acids or derivatives thereof such as esters, amides, imides, acylhalides and anhydrides of carboxylic acids, preferably in an amount of more than 0À1% wt. of the precipitated SiO 2 . The total amount of precipitated SiO 2 and carboxylic acid or derivative thereof is preferably not more than 50% wt. of the composition. In the examples compositions are prepared using a precipitated SiO 2 consisting of 94À5% wt. SiO 2 , 0À23% Fe 2 O 3 +Al 2 O 3 , 0À23% Na 2 SO 4 , and having a moisture content of 4À6% after drying for 2 hours at 105‹ C., an ignition loss (2 hrs., 1000‹ C.) of 4À53%, and a pH value (5% aqueous suspension) of 6À3 and (1) a methylphenyl silicone fluid of viscosity 300 cs and a phenyl/methyl mol ratio of 1 : 3 alone or with terephthalic acid or trimellitic acid; (2) a dimethylsilicone fluid of viscosity 1000 cs; (3) a methylphenylsilicone fluid as in (1) but of viscosity 500 cs and any one of the following carboxylic acids or derivatives thereof: terephthalic acid, pyromelletic acid, succinic anhydride, sebacic acid, adipic acid, hexahydrophthalic acid, dimethyl naphthalene dicarboxylate, trimethyl trimellitate, trimelletic acid or anhydride, parahydroxybenzoic acid, phthalic anhydride, #-oxyethylphthalate, terephthalic acid, dimethyl terephthalate, and isophthalic acid; (4) a methylphenyl silicone fluid of viscosity 450 cs, and a phenyl/methyl mol ratio of 1 : 1, and a mixture of isophthalic acid and phthalic anhydride. The gel times of the compositions are determined. The compositions can be applied to a spinneret for melt spinning a thermoplastic polymer at a temperature not less than 270‹ C.