Title: POLYURETHANE FOAMS WITH DECREASED ALDEHYDE EMISSIONS, A PROCESS FOR PREPARING THESE FOAMS AND A METHOD FOR DECREASING ALDEHYDE EMISSIONS IN POLYURETHANE FOAMS

 Number/Link: WO2013116092

Applicant/Assignee: Bayer

Publication date: 8-08-2013

“Gist”: Use of small amounts of hexamethylenediisocyanate trimer or small amounts of “PHD” polyols result in reduced aldehyde emissions from flex foams.

Why it is interesting: Reduction of VOC emissions and especially emissions of formaldehyde and acetaldehyde are an important issue for the polyurethane flexible foam industry, especially for bedding and automotive applications. This invention teaches two “tricks” to help solve the problem.  To a (preferably) TDI-based flex foam formulation which comprises at least one SAN or PIPA filled polyol, 0.5-3 pbw of trimerized hexamethylene diisocyanate is added on 100 pbw of the isocyanate.  Alternatively 2-3 pbw of PHD polyol is added on 100 pbw of the iso-reactive component. In the art “PHD polyol” usually stands for a polyurea ‘filled’ polyol (polyharnstoff dispersion), but in this case it stands for polyhydrazodicarnbonamide filled polyols. These PHD polyols are prepared by reacting a hydrazine with an isocyanate (pref TDI80) in a base polyol, so they are actually a subset of ‘conventional’ PHD dispersions.  The patent application is a bit confusing in this respect.

Hydrazodicarbonamide