Title: VISCOELASTIC POLYURETHANE FOAM

 Number/Link:WO 2014/058857

Applicant/Assignee: BASF

Publication date: 17-04-2014

“Gist”: Using TDI, two high MW and high EO polyether triols, hydrolizable PDMS and DELA results in a flexible foam with a low Tg ánd a low resilience.

Why it is interesting: While viscoelastic or “memory” foams are popular in the furniture industry they are currently not used in e.g. car seats because of their limited use temperature. Typically these foams become too stiff at lowish temperatures and often too soft and resilient at higher temperatures. The current invention is about viscoelastic foams which are useful for transport applications because they show constant properties over a wide temperature range. This is accomplished by reacting TDI with a (about) 4000 MW,  75% EO triol, an EO-capped 6500 MW, 75% EO triol, quite some diethanolamine (DELA), and quite some (2.5 pdw in the examples)  hydrolyzable polydimethylsiloxane copolymer (PDMS), together with water and catalysts. The foams show two Tg’s one at about -20°C and a minor one at about -55°C (probably due to a seperate PDMS phase) which keeps the foams resilient at low temperatures. The -20°C polyether phase is probably mixed with the DELA-TDI phase resulting in a wide transition reaching to over 0°C. This results in a resilience of  about 30% which is quite high for a typical ‘memory’ foam.

Polyurethane “memory foam”