| 摘要 |
<p>1325268 Oxymethylene polymer-silica compositions CELANESE CORP 15 June 1971 [16 June 1970] 27915/71 Heading C3P A composition comprises (a) an oxymethylene polymer and (b) 0À001 to 2À0% of the polymer weight of a hydrophobic silica having a particle size of 10 to 100 millimicrons, a surface area of 50 to 400 square metres per gram, a bulk density of 2 to 25 pounds per cubic foot, and a pH of 3À5 to 10. The silica component may be a silica aerogel, fume silica or a precipitated silica, and may be rendered hydrophobic by treatment with a polysiloxane oil or an organo-silicon. In examples, a formaldehyde homopolymer or a trioxan-ethylene oxide-(optionally) butane diol diglycidyl ether copolymer is blended with various hydrophobic silicas conforming to the above limitations, and coated with dimethyl- or methyl hydrogen polysiloxane or an alkyl siloxane.</p> |
