Polyol pre-mixes having improved shelf life

Abstract

A polyol pre-mix containing at least one halogenated hydroolefin blowing agent and having improved shelf life stability is provided, wherein each polyol combined with the halogenated hydroolefin blowing agent has an apparent pH of between 3 and 11.4. Controlling the apparent pH of the polyol(s) enables the polyol pre-mix to be stored for extended periods of time and then used in combination with organic polyisocyanate to produce foam formulations having gel times and tack free times not significantly different from those exhibited when freshly prepared polyol pre-mix is used.

1 . A polyol pre-mix comprising:
 a) at least one blowing agent, including HCFO-1233zd; and   b) a polyol component comprised of at least one polyol;
 wherein each polyol of the polyol component has an apparent pH of at least 4 but no greater than 10 
 whereby the polyol pre-mix, after being stored for six months at 23°, exhibits an increase of less than 40% in at least one of gel time or tack free time when combined with an organic polyisocyante. 
   
     
     
         2 - 3 . (canceled) 
     
     
         4 . The polyol pre-mix of  claim 1 , wherein each polyol of the polyol component has an apparent pH of at least 4 but no greater than 9. 
     
     
         5 . The polyol pre-mix of  claim 1 , wherein the polyol component is comprised of one more polyols selected from the group consisting of polyether polyols, polyester polyols, polyether/ester polyols and combinations thereof. 
     
     
         6 . The polyol pre-mix of  claim 1 , wherein the polyol component is comprised of one or more polyols having functionalities of from 2 to 7. 
     
     
         7 . The polyol pre-mix of  claim 1 , wherein the polyol component is comprised of at least one polyether polyol and at least one polyester polyol. 
     
     
         8 . The polyol pre-mix of  claim 1 , wherein the polyol component contains 0 to 100 parts by weight polyester polyol per 100 parts by weight total polyol component and 100 to 0 parts by weight polyether polyol per 100 parts by weight total polyol component. 
     
     
         9 . The polyol pre-mix of  claim 1 , wherein the polyol component contains 10 to 90 parts by weight polyester polyol per 100 parts by weight total polyol component and 90 to 10 parts by weight polyether polyol per 100 parts by weight total polyol component. 
     
     
         10 . The polyol pre-mix of  claim 1 , wherein the polyol component contains 20 to 80 parts by weight polyester polyol per 100 parts by weight total polyol component and 80 to 20 parts by weight polyether polyol per 100 parts by weight total polyol component. 
     
     
         11 . The polyol pre-mix of  claim 1 , wherein the polyol component is comprised of at least one polyether polyol and at least one aromatic polyester polyol. 
     
     
         12 . The polyol pre-mix of  claim 1 , wherein each polyol of the polyol component has a viscosity of from 400 to 60,000 cps at 25° C. 
     
     
         13 . The polyol pre-mix of  claim 1 , wherein each polyol of the polyol component has a number average molecular weight of from 250 to 6500 Daltons. 
     
     
         14 - 15 . (canceled) 
     
     
         16 . The polyol pre-mix of  claim 1 , additionally comprising at least one surfactant. 
     
     
         17 . The polyol pre-mix of  claim 1 , additionally comprising at least one catalyst. 
     
     
         18 . The polyol pre-mix of  claim 1 , additionally comprising at least one surfactant and at least one catalyst. 
     
     
         19 . A polyurethane or polyisocyanurate foam which is the reaction product of a polyol pre-mix in accordance with  claim 1  and at least one organic polyisocyanate. 
     
     
         20 . A method of making a polyurethane or polyisocyanurate foam, comprising reacting a polyol pre-mix in accordance with  claim 1  and at least one organic polyisocyanate. 
     
     
         21 . The method of  claim 20 , wherein the polyol pre-mix is prepared by blending the at least one blowing agent and the polyol component and aging the resulting polyol pre-mix for at least one month at ambient temperature prior to reacting the polyol pre-mix with the at least one organic polyisocyanate. 
     
     
         22 . A method of making a polyol pre-mix having improved shelf life, comprising selecting a polyol or plurality of polyols, measuring the apparent pH of each polyol, confirming that the measured apparent pH of each polyol is within the range of 4 to 10, and combining the polyol or plurality of polyols with at least one blowing agent, HCFO-1233zd, to form the polyol pre-mix, whereby the polyol pre-mix, after being stored for six months at 23, exhibits an increase of less than 40% in at least one of gel time or tack free time when combined with an organic polyisocyante. 
     
     
         23 . The method of  claim 22 , comprising an additional step of adjusting the apparent pH of at least one polyol prior to combining the polyol or plurality of polyols with the at least one blowing agent. 
     
     
         24 . The method of  claim 23 , wherein the adjusting of the apparent pH is carried out by combining the polyol with at least one C1 to C15 carboxylic acid or ester containing at least one carboxyl functional group (—COOH). 
     
     
         25 . The polyol pre-mix of  claim 1 , wherein the at least one blowing agent consists essentially of HFCO-1233zd. 
     
     
         26 . The method of  claim 22 , wherein the at least one blowing agent consists essentially of HFCO-1233zd.