Patent Title: METHOD FOR PRODUCING A POLYISOCYANURATE COMPOSITE MATERIAL
Number/Link: WO 2017/191216 (German)
Applicant/Assignee: Covestro
Publication date: 9 November 2017
“Gist”: Partially trimerized aliphatic diisocyanates are mixed with glass fiber and reacted using a trimerization catalyst
Why it is interesting: Conventional fiber-reinforced composites based on unsaturated polyesters, epoxies, polyurethane and the like are not weather-stable and need to be coated for outdoor use. Weather stable polyisocyanurate composites are known (WO2007/096216 – Huntsman) but are based on aromatic diisocyanates and show high reactivity and short ‘pot life’. According to this invention, PIR composites with improved reaction profile and weatherability can be prepared from partially trimerized aliphatic diisocyanates with a diisocyanate monomer content of less than 20% (w/w). In the examples commercially available HDI and IPDI trimer is used together with short glass fiber and a potassium acetate/PEG 400 blend as catalyst cured at a temperature of 160 to 180°C.