Six (6) Dow Patents on ‘Conventional’ PIPA Polyols

Title: POLYISOCYANATE POLYADDITION POLYOL MANUFACTURING PROCESS USING STABILIZERS  (and 5 more)

 Number/Link: WO2015038825 WO2015038826 WO2015038827 WO2015038828 WO2015038829 WO2015038830

Applicant/Assignee: Dow

Publication date: 19-03-2015

Gist”: PIPA polyols based on conventional polyols and their applications

Why it is interesting: Polyisocyanate polyaddition or PIPA polyols are a type of polymer polyol consisting of a base polyol and dispersed polyurethane particles. These polyols are prepared by dispersing and reacting in situ an isocyanate and a low molecular weight polyol (e.g. triethanolamine) in a ‘base’ polyol. The reaction is balanced such, that a controlled amount of grafting of the base polyol onto the PU particles results, which stabilizes the dispersion. The need for grafting is the reason why PIPA polyols are always based on EO-tipped (high primary OH) polyols, limiting their use mainly to the production high resilience (HR) foams. The current inventions by Dow devise ways to make PIPA polyols in ‘conventional’ (i.e. low primary OH) polyols either by the use of specific stabilizers (in the WO..25 application) or by pre-reacting part of the iso with the base-polyol before adding the low MW polyol (in the WO..26 application). The WO..27 to WO..29 applications are concerned with the use of these ‘conventional’ PIPA polyols to prepare conventional-, viscoleastic- and combustion modified flexible foams respectively.  W0..30 is concerned with thixotropic PIPA polyols based on urethane-modified isocyanurates.

Flexible foam blocks

Flexible foam blocks

 

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