Blowing agent compositions for insulating foams

Abstract

Disclosed is a blowing agent composition comprising a hydrofluoroolefins (HFO) and a branched hydrocarbon, and a foamable polymer composition comprising the blowing agent composition. Also disclosed is a method of making a polymer foam utilizing a blowing agent composition comprising an HFO and a branched hydrocarbon.

What is claimed is: 
     
         1 . A foamable polymer composition comprising:
 a matrix polymer composition comprising polystyrene; and   a blowing agent composition comprising:
 from 1 to 5 wt. % of a hydrofluoroolefin (HFO) blowing agent comprising HFO-1234ze; 
 from 0.05 to 1 wt. % of a branched hydrocarbon blowing agent; and 
 from 0.05 to 5 wt. % of a hydrofluorocarbon (HFC) blowing agent, 
   wherein the foamable polymer composition contains essentially no water, and   wherein each wt. % is based upon the total weight of the foamable polymer composition.   
     
     
         2 . The foamable polymer composition of  claim 1 , wherein the blowing agent composition consists of the HFO blowing agent, the branched hydrocarbon blowing agent, and the HFC blowing agent. 
     
     
         3 . The foamable polymer composition of  claim 1 , wherein the branched hydrocarbon blowing agent is selected from the group consisting of: isobutane; isopentane; neopentane; isohexane; 3-methylpentane; 2,3-dimethylbutane; neohexane; isoheptane; 3-methylhexane; 2,2-dimethylpentane; 2,3-dimethylpentane; 2,4-dimethylpentane; 3,3-dimethylpentane; 3-ethylpentane; 2,2,3-trimethylbutane; and combinations thereof. 
     
     
         4 . The foamable polymer composition of  claim 3 , wherein the branched hydrocarbon blowing agent consists of isobutane. 
     
     
         5 . The foamable polymer composition of  claim 1 , wherein:
 the HFO blowing agent consists of HFO-1234ze;   the branched hydrocarbon blowing agent consists of isobutane; and   the HFC blowing agent consists of 1,1-difluoroethane.   
     
     
         6 . The foamable polymer composition of  claim 1 , wherein the foamable composition comprises less than 0.03 moles HFO blowing agent per 100 grams of matrix polymer. 
     
     
         7 . A foamable polymer composition comprising:
 a matrix polymer composition comprising polystyrene; and   a blowing agent composition comprising:
 from 1 to 5 wt. % of a hydrofluoroolefin (HFO) blowing agent comprising HFO-1234ze; 
 from 0.05 to 1 wt. % of a branched hydrocarbon blowing agent; and 
 from 0.05 to 5 wt. % of a co-blowing agent comprising carbon dioxide, 
   wherein the foamable polymer composition contains essentially no water, and   wherein each wt. % is based upon the total weight of the foamable polymer composition.   
     
     
         8 . The foamable polymer composition of  claim 7 , wherein the blowing agent composition consists of the HFO blowing agent, the branched hydrocarbon blowing agent, and the carbon dioxide. 
     
     
         9 . The foamable polymer composition of  claim 7 , wherein the branched hydrocarbon blowing agent is selected from the group consisting of: isobutane; isopentane; neopentane; isohexane; 3-methylpentane; 2,3-dimethylbutane; neohexane; isoheptane; 3-methylhexane; 2,2-dimethylpentane; 2,3-dimethylpentane; 2,4-dimethylpentane; 3,3-dimethylpentane; 3-ethylpentane; 2,2,3-trimethylbutane; and combinations thereof. 
     
     
         10 . The foamable polymer composition of  claim 9 , wherein the branched hydrocarbon blowing agent consists of isobutane. 
     
     
         11 . The foamable polymer composition of  claim 7 , wherein:
 the HFO blowing agent consists of HFO-1234ze;   the branched hydrocarbon blowing agent consists of isobutane; and   the co-blowing agent consists of carbon dioxide.   
     
     
         12 . The foamable polymer composition of  claim 7 , wherein the foamable composition comprises less than 0.03 moles HFO blowing agent per 100 grams of matrix polymer. 
     
     
         13 . A method of manufacturing polymer foam, comprising:
 a) providing a matrix polymer composition comprising polystyrene;   b) melting the matrix polymer composition in an extruder;   c) injecting a blowing agent composition comprising into the molten matrix polymer composition within the extruder to form a foamable polymer composition, wherein the blowing agent composition comprises:
 from 1 to 5 wt. % of a hydrofluoroolefin (HFO) blowing agent comprising HFO-1234ze; 
 from 0.05 to 1 wt. % of a branched hydrocarbon blowing agent; and 
 from 0.05 to 5 wt. % of a co-blowing agent comprising a hydrofluorocarbon (HFC), carbon dioxide, or combinations thereof, 
 wherein each wt. % is based upon the total weight of the foamable polymer composition, 
 wherein the foamable polymer composition contains essentially no water or carbon dioxide; and 
   d) extruding the foamable polymer composition to form a polymer foam.   
     
     
         14 . The method of  claim 13 , wherein the polymer foam has an R value from 4 to 7.