摘要 |
The present invention relates to blowing agent compositions comprising tetrafluoropropene (HFO) and at least one co-blowing agent selected from carbon dioxide, water, alkanes and an alcohol used in the preparation of foamable thermoplastic compositions having low density. The HFOs include, but are not limited too, cis- and/or trans-1,3,3,3-tetrafluoropropene (HFO-1234ze), 2,3,3,3-tetrafluoropropene (HFO 1234yf), or mixtures thereof. The blowing agent compositions are useful in the production of low density insulating foams with improved R value. |