Title: Reducing Emissions in Polyurethane Foam

 Number/Link: US2013137787

Applicant/Assignee: Air Products

Publication date: 30-50-2013 (priority PCT/US)

“Gist”: Use of reactive amine catalysts without primary hydroxyl groups, together with diacids results in flexible foams with good compression set and low emissions.

Why it is interesting: Reduction of VOC emissions is an important driver in the flexible foam industry and volatile amine catalysts are among the most commonly used additives that need to be removed. Current practice is to use isocyanate-reactive catalysts, sometimes combined with acids to get a ‘delayed-action’ effect which is useful to fill complex moulds. Isocyanate-reactive catalysts act as chain stoppers hoewever and can result in loss of properties, especially fatigue properties like compression set, and the acids used can contribute to the VOC emissions. According to this invention flexible foams with low emissions and with good compression set properties can be made by using a tert-amine catalyst comprising a reactive group which is chosen from amine, amide, urea or sec-hydroxyl ( so no primary hydroxyl) together with a di-acid like maleic-, succinic-, azaleic-, sebacic acid etc. To me it is not immediatly clear why this should work and no mechanism or explanation is given in the application.

DMAPA – a reactive catalysts according to the invention