Title: RIGID POLYURETHANE FOAM

 Number/Link: EP2591034A1

Applicant/Assignee: BASF

Publication date: 15-05-2013  (priority PCT/EP)

“Gist”: Use of novolac polyols in rigid (spray) foams to improve reactivity and flammability properties.

Why it is interesting: ‘Novolacs’ are phenol-formaldehyde (PF) resins which are produced at a p:f ratio of  >1 (as opposed to ‘resols’ where this ratio is <1) Novolacs are therefore phenol (OH) ended and can be used together with isocyanates to prepare hybrid polyurethanes. In this case novolacs with a functionality of about 4-8 are used together with conventional rigid foam polyol(s) in which the novolacs are dissolved (after heating and opt. melting) in an amount of about 40%. Together with polymeric MDI, water and conventional additives rigid (spray) foams are produced with improved flammibility, smoke, scorching and reactivity properties.

Novolac resin