| 摘要 |
<p>1335754 Silicon dioxide fibres BAYER AG 19 Aug 1971 [20 Aug 1970] 38945/71 Heading C1A SiO 2 gel or quartz fibres are spun from a soln. of a tetraalkoxysilane which has been hydrolysed with at least 2 mols. of H 2 O per mol. silane or of a sole. of a alkoxypolysiloxane which has been hydrolysed with at least 0À5 mol. H 2 O per alkoxy group present, in the presence of a dissolved poly-lower alkylene oxide. The alkoxy group may have 1-4 carbon atoms. An alcohol with 1-4 carbon atoms and a strong acid, e.g. HCl may be present in the soln. to act as a solubilizer and catalyst respectively. The gel fibres formed contain 70-100% by wt. SiO 2 , 0-20% by wt. H 2 O, 0-20% by wt. alkoxy groups and <2% by wt. acid radicals. The gel fibres may be heated in air or N 2 at 100-1000‹ C. to give amorphous fibres having a tensile strength of 30-120 kp./mm.<SP>2</SP>, a Young's modulus of 1000-7300 kp./mm.<SP>2</SP>, a S.A. of <1m.<SP>2</SP>/g. and a carbon content of <15% by wt.</p> |
