Hybrid Polyisocyanurates for Composites and Coatings

Patent Title: DUAL-CURING ISOCYANURATE POLYMERS

 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

HDI-trimer


Catalyst System for Frothed Foams

Patent Title: METHOD FOR DELAYING CURING IN POLYURETHANE AND COMPOSITIONS AND ARTICLES MADE THEREFROM

 Number/Link: WO2018/075302

Applicant/Assignee:  Rogers

Publication date: 26-April-2018

Gist”: A mixture of  a metal acetylacetonate and a catalytic inhibitor prevents premature curing

Why it is interesting:  A catalyst system that prevents premature curing of frothed (PORON® – type) foams consists of  ferric acetylacetonate catalyst and a β-diketone inhibitor e.g. acetylacetone or dibenzoyl methane. The catalyst combination allows for handling of the raw materials at 55°C for 5 minutes without reacting.  Frothed foams tend to have improved properties, like compression set as compared to conventional foams.

Tris(acetylacetonato)iron(III)

Tris(acetylacetonato)iron(III)  (Wikipedia)

Polycarbonate PU Foams with Reduced VOC Emissions

Title: POLYURETHANE FOAMS BASED ON POLYETHER CARBONATE POLYOLS

Number/Link: WO2017/085201 (German)

Applicant/Assignee: Covestro

Publication Date: 26-may-2017

“Gist”: Use of urea reduces the formation of propylenecarbonate from polycarbonate polyols

Why it is interesting: Covestry is betting heavily on polyethercarbonate polyols for use in polyurethane foams, using the carbon-negative footprint as a selling point. The use of polyethercarbonate polyols in PU foams can, however, result in the formation of propylenecarbonate resulting from a retro reaction promoted by conventional amine catalysts. Propylenecarbonate will contribute to the total VOC emissions of foams and other materials. According to this invention, the retro reaction can -surprisingly- be prevented or reduced by using urea or urea-derivatives in the foam formulation. In the examples urea and dimethylaminopropylurea are used together with a tin catalyst,  polyethercarbonate polyols and TDI to produce flexible foams with reduced propylenecarbonate content.

Propylenecarbonate