Title: USE OF POLY(BUTYLENE OXIDE) POLYOL TO IMPROVE DURABILITY OF MDI-POLYURETHANE FOAMS

Patent Number & Link:  US2013178548    (related case US2013178550 )   

Applicant/Assignee: Dow

Publication date: 11-07-2013 (priority PCT/US)

“Gist”: Use of a high molecular weight butyleneoxide monol to improve the compression set of viscoelastic foams.

Why it is interesting: Viscoelastic or “memory” flexible foams are currently popular for use in matresses and pillows. Much research and development has been done on these materials and the patent situation is a true minefield. Usually a mixture of EO-rich and PO-rich polyols of different molecular weights is used to control the glass transition temperature (Tg) of the softblock, wich in turn controls the energy absorption (and thus the resilience) of the foam. In this invention a butyleneoxide monol of high MW is used in addition to a mixture of EO-rich and PO-rich polyols. The BO-monol is used in an amount of 2-10% on the polyol  and supposedly improves compression set while retaining the open cell character (air flow) of the foam.
The related case (US2013/178550) is similar but uses a high MW PO polyol with a functionality between 1 and 4 instead of the BO monol.  It is not immediately clear to me whether this latter case is a real invention or is just plugging a hole in the minefield..

A viscoelastic flexible foam