| 摘要 |
A continuous process for manufacturing quick-setting phenolic foams is improved by using as the hardening agent a concentrated, substantially anhydrous solution of boron trioxide, and using as the blowing agent an organic liquid having a boiling point of 20 DEG -80 DEG C. Curing times are shortened and the resultant foam, having uniformly molecularly dispersed therein about 0.25-10.5% by weight of boron, calculated as boric anhydride, has substantially uniform cells, improved fire resistance characteristics and superior mechanical properties. |
