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, compared to conventional foams.

Tris(acetylacetonato)iron(III)

Tris(acetylacetonato)iron(III)  (Wikipedia)

Optical Polyurethane Elastomers

Patent Title: COMPOSITION FOR TRANSPARENT SHAPED BODIES BASED ON POLYURETHANE

 Number/Link: WO2016/113295

Applicant/Assignee: Covestro

Publication date: 21-07-2016

Gist”: Use of amino-chelate-tin complex as delayed action catalyst for transparent PU elastomers

Why it is interesting: Lenses for eyeglasses are increasingly made from transparent organic polymers like polyurethane elastomers. The production requires a specialized casting process into glass moulds, followed by an exact tempering over many hours. According to this invention polyurethane elastomers, useful for the production of eyeglass lenses, can be made form a composition containing a polyol, a cycloaliphatic or araliphatic diisocyanate, an internal mould release agent and a thermo-latent catalyst. The catalyst is an inorganic metal complex comprising Sn (preferred) and at least one tert-amine containing chelating ligand. The composition is said to have a longer ‘open-time’ as the catalyst-free system.

Example of thermo-latent catalyst according to the invention

Example of thermo-latent catalyst according to the invention