Title: PROCESS FOR THE PREPARATION OF A POLYOL COMPOSITION

 Number/Link: WO2014/037558

Applicant/Assignee: SHELL

Publication date: 13-03-2014

“Gist”: A PIPA polyol is made from TDI,  TELA and a high sec-OH polyol which is added in two stages.

Why it is interesting: PIPA polyols are a class of ‘filled’ polyols containing dispersed polyurethane particles and are often used in flexible foams to improve hardness and air flow. These polyols are usually produced by dispersing an olamine, like triethanolamine (TELA), in an EO-tipped EO/PO polyether polyol and reacting it with isocyanate under mixing.  Producing PIPA polyols from a high secondary-OH containing (“conventional”) polyol, i.e. an all- PO or EO/PO random polyol would have cost advantages but -according to SHELL- results in an unstable polyol which produces closed-celled flexible foam. The trick they invented to solve this problem is to produce the particle dispersion from TELA and TDI in about 50% of the total amount of polyol used and adding the remainder of the polyol in a second step.  Remarkably this simple trick appears to be new and patentable.

Triethanolamine