Title: REINFORCED PULTRUDED POLYURETHANE AND PRODUCTION THEREOF
Number/Link: US2013/0309924
Applicant/Assignee: Bayer
Publication date: 21-11-2013 (priority PCT/DE)
“Gist”: A pultrusion matrix material is formulated from of an immiscible polyol blend together with one or more epoxides and MDI
Why it is interesting: Pultrusion matrix systems need a decent pot-life and, after curing, a high glass transition temperature and modulus. According to the invention this can be achieved by using an immiscible polyol mixture prepared from a) a relatively high MW PO polyol (e.g. PPG4000) and b) a blend of low MW polyols and chain extenders/crosslinkers, where the amount of a) is about 10-30% on the total polyol. This polyol system together with an epoxide (e.g. bisphenol A or the triglycidylether of trimethylolpropane) an isocyanate (e.g polymeric MDI) and optional additives results in a system useful for a pultrusion process. The examples show a pot-life of about 30 minutes and a Tg of about 150°C. The immiscible high MW PO polyol probably forms a seperate phase, thus increasing the Tg of the hard phase.
Diagram of the Putrusion Process (Wikipedia)
Innovation in Polyurethanes 