| abstract |
The present invention relates to blowing agent compositions comprising (1) at least one hydrofluoroolefin (HFO) and (2) at least one hydrochlorofluoroolefin (HCFO) used in the preparation of foamable thermoplastic compositions. The HFOs of component (1) include, but are not limited too, 3,3,3-trifluoropropene (HFO-1243zf), 1,2,3,3,3-pentafluoropropene (HFO-1225ye), cis- and/or trans- 1,3,3,3-tetrafluoropropene (HFO-1234ze), and 2,3,3,3-tetrafluoropropene (HFO 1234yf), and mixtures thereof. The HCFOs of component (2) include, but are not limited to, 1-chloro-3, 3,3-trifluoropropene (HCFO-1233zd), 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and mixtures thereof. The blowing agent compositions are useful in the production of low density insulating foams with improved k-factor. |