| 摘要 |
<p>1417490 Foundry moulds; silicone compositions HOWMET CORP 19 Dec 1973 [10 Jan 1973] 58751/73 Headings C3N and C3T A method for the preparation of cores for use in the casting of high melting point metals comprises forming a core composition containing a filler, a polysiloxane and a catalyst system, preferably in an amount 0À05-3% by weight based on the polysiloxane comprising an anhydride of an organic carboxylic acid into a core configuration, and baking and firing the core configuration to effect cure of the polysiloxane and to convert the polysiloxane into a siliceous material to bond the filler. The anhydride may be phthalic anhydride, benzoic anhydride, isobutytric anhydride, cyclohexanoic anhydride, maleic anhydride, camphoric anhydride, diphemic anhydride or isatoic anhydride. The catalyst system may also include magnesium oxide. The filler may be graphite, silica, alumina or zircon. The core composition may also contain paraffin wax, styrene, phenolic resins, phenol, fatty amines such as N,N<SP>1</SP>-distearyl ethylenediamine or wood flour.</p> |
