| 摘要 |
<p>1302446 Polysiloxane resin moulding compositions WACKER-CHEMIE GmbH 21 April 1970 [23 April 1969] 18987/70 Heading C3T A moulding composition comprises (a) an organopolysiloxane containing Si-bound OH and phenyl groups, (b) a filler, (c) a catalytic inorganic lead compound, and (d) 0À1-15 wt. per cent of (a) of a ketone of b.p. at least that of acetylacetone at 760 mm. Hg and m.p. below the moulding temperature of the composition, or of a metal enolate of such a ketone. Preferably (a) contains at least 0À1 wt. per cent OH and up to 3 wt. per cent of alkoxy groups, 0À3- 1À2 Ph groups per Si and 0À9-1À7 Si-bound organic groups per Si; (b) may be e.g. pyrogenic, precipitated or aerogel silica, quartz meal, mica meal, Mg or Ca or Zr silicate, asbestos or glass fibres or powder, TiO 2 , Al 2 O 3 or gound porcelain; (c) may be e.g. Pb 3 (OH) 2 (CO 3 ) 2 , PbCO 3 , PbO or PbO 2 ; and (d) may be a longchain aliphatic or an aromatic ketone or enolate. In examples, methyl phenyl-polysiloxane resins, having 0À1 wt. per cent OH and Ph : (Ph+Me) : Si ratio 0À75 : 1À0 : 1, or 0À1% OH plus 1% OEt and ratio 0À726 : 1À1 : 1, or 4% OH plus 1% OEt and ratio 0À6 : 1À1 : 1, are dissolved in CH 2 Cl 2 or acetone and mixed with ground quartz or Ca silicate or quartz plus treated glass fibre (as filler), Ca stearate (mould release agent), iron oxide black or red (pigment), Pb 3 (OH) 2 (CO 3 ) 2 (catalyst), and the ketone or enolate, and the mixture is dried or powdered. The ketones and enolates used are: acetylacetone, di-heptadecyl ketone, phenylacetone, benzoylacetone, benzophenone and acetophenone; and Al, Zn, Co, and Ti acetylacetonates and Al benzoylacetonate.</p> |
