| 摘要 |
<p>A method of insulating an article against high temperatures and flames comprises interposing between the article and the source of heat and flames a layer of an insulating composition comprising a refractory filler in an unfoamed matrix of a cured polyurethane polymer. The composition may be coated, e.g. by trowelling, before curing, over that surface of the article against which the flames would otherwise impinge and is then cured in situ. Alternatively, it may be premoulded and cured and then be bonded into place with additional quantities of the uncured composition as a cement which is then cured in situ. In examples, liquid prepolymers are prepared from excess toluene diisocyanate and (1) castor oil, (2) and (3) polyester from adipic acid, ethylene glycol and propylene glycol. The refractory material may be chrysolite, crocidolite, asbestos, silicon carbide, alumina, flint quartz, diatomaceous earth, ceramic fibres, glass fibres and fibrous magnesium silicate talc. Cross-linking agents specified are aliphatic alcohols and aminoalcohols such as castor oil, ricinoleyl alcohol, triisopropanolamine. They may be used together with 2,4,6-tri -(dimethylaminomethyl)phenol or N,N, N1,N1 - tetrakis - (2 - hydroxypropyl)ethylene diamine. In examples (4) to (7) prepolymer is mixed with various refractories and catalysts to give compositions which can be applied by trowelling.</p> |
