| 摘要 |
<p>1,201,105. Self-extinguishing phenol-formaldehyde resin foams; aminoplast compositions. COMPAGNIE DE SAINT GOBAIN. 19 April, 1968 [30 May, 1967], No. 18684/68. Headings C3C and C3R. Fire - resistant phenol - formaldehyde resin foams are made by introducing into an aq. solution containing the resin a surface-active silicone oil, a blowing agent and a nitrogen compound unreactive with uncombined formaldehyde in the resin, stable at the temperature of the process with respect to the blowing agent and releasing on heating a gas which does not support combustion. The nitrogen compound may be a partially condensed aminoplast resin, e.g. the reaction product of formaldehyde with urea, melamine, dicyandiamide or other amine, and optionally phenol, or it may be an ammonium salt, e.g. ammonium sulphite or sulphamate. In examples, phenol was condensed with formaldehyde in aq. solution using as catalyst NaOH, Ba(OH) 2 .8H 2 O or polyvinyl alcohol and then compounded with a silicone oil, trichlorofluoromethane as blowing agent, optionally talc or kieselguhr, and hydrochloric acid and a partially condensed aminoplast resin or ammonium salt.</p> |
