Patent Title: VISCOELASTIC POLYURETHANE FOAMS WITH REDUCED TEMPERATURE SENSITIVITY
Number/Link: WO2018/169833
Applicant/Assignee: Covestro
Publication date: 20 September 2018
“Gist”: A polyol blend comprising a relatively low-EO monol, diol and triol is foamed with TDI
Why it is interesting: Viscoelastic or “memory” foams are popular materials for pillows and mattresses. One drawback of these materials is the sensitivity of hardness to room temperature variations. According to this invention the hardness variations can be reduced by preparing the foams form TDI and a polyol blend comprising a monofuntional polyether with an EO content of less than 20%, a polyether diol and a polyether triol both with an EO content of less than 45% together with water, catalysts and other additives. The polyol blend can optionally be made in situ. The foams show an E'(15°C)/E'(30°C) ratio between 1 and 4, a Tg of less than 20°C (defined as the temperature of max. tanδ), together with high air flow and tear strength values.

DMTA trace of foam according to the invention