Hybrid Polyisocyanurates for Composites and Coatings


 Number/Link:WO2018/087395 WO2018/087396  WO2018/087399 (German)

Applicant/Assignee:  Covestro

Publication date: 17 May 2018

Gist”:  Di-isocyanate trimer is reacted with hydroxymethacrylates and polyacrylates in the presence of a trimerization catalyst. 

Why it is interesting: According to these inventions a reaction system with two curing modes can be prepared by mixing high functionality oligomeric isocyanate, ethylenically unsaturated compounds, unsaturated compounds containing isocyanate-reactive groups, timerization catalyst and a free-radical initiator at an NCO index of 100 to 200. The system shows a relatively low viscosity and can e.g. be used in fiber-reinforced composites and in coatings. In the examples HDI trimer is reacted with hexanedioldimethacrylate and hydroxypropylmethacrylate in the presence of potassium acetate and a peroxybenzoic acid.

HDI isocyanurate



Spray Foam with Increased Reactivity


 Number/Link: WO2016/162362

Applicant/Assignee: Covestro

Publication date: 13-10-2016

Gist”: Addition of dicarboxilic acid reduces cream time in amine catalyzed foams

Why it is interesting: A short cream time has advantages for rigid PU spray foam because it can reduce dripping of the material after application.  According to this invention the cream time of an amine-catalyzed, HFC-blown spray foam composition can -surprisingly-be reduced by addition of a dicarboxilic acid, preferably succinic or glutaric acid. The diacids are used in a ratio of about 2 equivalents acid to 1 equivalent of (free) amine. In the examples a clear reduction of cream time is shown compared to compositions with no diacid, a mono-acid or less than the required amount of diacid. However, all examples also contain some trimerization catalyst (2-hydroxypropyl trimethylammonium formate) next to the tert-amine catalyst (N,N-dimethylcyclohexylamine). It would be interesting to see an example without the trimerization catalyst i.m.o.

Succinic acid.

Succinic acid


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