Processing aids for use in manufacture extruded polystyrene foams using low global warming potential blowing agents
A foamable polymeric mixture is provided that includes a polymer composition and at least one blowing agent. The blowing agent may comprise any blowing agents known not to deplete the ozone or increase the prevalence of global warming, such as CO 2 , HFO, HFC and mixtures thereof. The foamable polymeric mixture may further includes at least one processing aid comprising an organic phase changing material. The inventive foamable mixture is capable of processing at a pressure range of 800 to 1200 psi (5.5 to 8.3 MPa).
1 . A foamed insulation product formed from a foamable polymeric mixture, the foamable polymeric mixture consisting of:
polystyrene;
a blowing agent consisting of carbon dioxide, wherein the carbon dioxide is present in an amount from 0.05 to 5 wt. % of the foamable polymeric mixture;
from 0.05 to 3 wt. % of an organic phase changing material, wherein the organic phase changing material has a transition temperature from liquid to solid at a temperature from −5 to 60° C., and wherein the organic phase changing material consists of microencapsulated synthetic beeswax; and
optionally, one or more of an infrared attenuating agent, a flame retarding agent, a nucleating agent, a pigment, a biocide, and a UV absorber,
wherein each wt. % is based upon the total weight of the foamable polymeric mixture,
wherein the foamed insulation product has an average cell size of from 0.16 to 0.2 mm,
wherein the foamed insulation product has an insulation R-value per inch of between 4 and 7; and
wherein the foamed insulation product has a compressive strength between 6 and 80 psi.
2 . The foamed insulation product of claim 1 , wherein the foamed insulation product is monomodal.
3 . The foamed insulation product of claim 1 , wherein the foamed insulation product has a density of from 1 to 5 lbs/ft 3 .
4 . The foamed insulation product of claim 1 , wherein the organic phase changing material has a transition temperature from liquid to solid of 24° C.
5 . The foamed insulation product of claim 1 , wherein the carbon dioxide comprises from 3.7 to 4.3 wt. % of the foamable polymeric mixture.
6 . The foamed insulation product of claim 1 , wherein the foamed insulation product is a closed cell, extruded foamed insulation product.
7 . The foamed insulation product of claim 1 , wherein the organic phase changing material is compounded in a carrier material to form a masterbatch.