Production of low density polypropylene foam
AssigneeAmoco Corporation
InventorsJosef Alteepping, Juergen P. Nebe
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Abstract
A method of producing a foamed product having a density less than 0.2 g/cm.sup.3, which comprises foaming a composition comprising a major proportion of a low viscosity polypropylene component having a melt viscosity (at 190.degree. C. and a shear rate of 1000 sec.sup.-1) of less than 2.times.10.sup.3 poise and a minor proportion of a high viscosity polypropylene component having a melt viscosity (at 190.degree. C. and a shear rate of 1000 sec.sup.-1) of greater than 2.5.times.10.sup.3 poise.
Claims25
A method of producing a foamed product having a density less than 0.2 g/cm.sup.3 which comprises foaming a composition comprising a major proportion of a low viscosity polypropylene component having a melt viscosity (at 190.degree. C. and a shear rate of 1000 sec.sup.-1) of less than 2.times.10.sup.3 poise and a minor proportion of a high viscosity polypropylene component having a melt viscosity (at 190.degree. C. and a shear rate of 1000 sec.sup.-1) of greater than 2.5.times.10.sup.3 poise.
A method of producing a foamed product having a density less than 0.2 g/cm.sup.3 which comprises foaming a composition comprising a major proportion of a low viscosity polypropylene component having a weight average molecular weight in the range from 100,000 to 500,000 and a minor proportion of a high viscosity polypropylene component having a weight average molecular weight greater than 500,000.
Dependencies are inferred from the claim text.