| 摘要 |
<p>1365939 Thermoset foam sheets DOW CHEMICAL CO 17 Dec 1971 [21 Dec 1970] 58725/71 Headings C3C and C3R [Also in Division B5] Thermoset foam sheets 22 are obtained by mixing two reactants between constraining substrates, the mixing taking place at 11 between nip rollers 5. As shown, the reactants are separately coated on to the substrates; alternatively one reactant is applied to the substrates, the second then being applied by spraying at 11. The substrates may be constituted by endless belts 21 which also form a sizing device, or may be layers which are fed through rolls 5 and a separate sizing device before removal from the sheet (see also Division B5). The foam may be a polyurethane, preferably rigid or semi-rigid, obtained by reacting a polyol and a polyisocyanate, an epoxy resin obtained by reacting a polyepoxide with a curing agent, polyesters, polyvinyl esters or phenolics. Other additives, e.g. foaming agents, e.g. trichloromonofluoromethane are included. In an example, a polyurethane is obtained as part of a laminated construction by reacting (1) polymethylene polyphenylisocyanate with (2) propylene oxide-diethylenetriamine polyol mixed with silicone oil, dibutyltin dilaurate and CFCl 3 .</p> |
