Low density oriented polymer composition with inert inorganic filler
OwnerKevin L. Nichols, Brett M. Birchmeier +6inventors
InventorsKevin L. Nichols, Brett M. Birchmeier, Ian M. Ward, Philip D. Coates, Phil Caton-Rose, Glen P. Thompson, Vijay Wani, Rajen M. Patel
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Abstract
An oriented polymer composition containing thirty to 95 weight-percent inert inorganic filler and a continuous phase of at least one orientable polymer contains void spaces due to cavitation and has a density of less than 0.8 grams per cubic centimeter, a flexural modulus of 1.4 gigapascals or more, cross section dimensions all greater than 1.5 millimeters, a delamination force value of 44.5 Newtons (ten pounds force) or more and little or no blowing agent.
Claims12
A process for solid state drawing a polymer composition to produce an oriented polymer composition article, the process comprising the steps:
- (a) providing a polymer composition comprising thirty weight-percent or more and 95 weight-percent or less of an inert inorganic filler based on polymer composition weight and a continuous phase of at least one orientable polymer, the polymer composition having a melt temperature;
- (b) conditioning the temperature of the polymer composition to a drawing temperature that is fifteen degrees Celsius or more and forty degrees Celsius or less below the polymer composition's softening temperature;
- (c) drawing the polymer composition though a drawing die at a drawing rate of at least 0.25 meters per minute and with a nominal draw ratio of 1.25 or more and 8 or less;
- and
- (d) optionally, cooling the polymer composition after it exits the drawing die;
- wherein the polymer composition comprises less than three weight-percent blowing agent based on polymer composition weight and wherein the oriented polymer composition article has a density of less than 0.8 grams per cubic centermeter, a flexural modulus of 1.4 gigapascals or more, cross sectional dimensions all greater than 1.5 millimeters, a delamination force value greater then 44.5 Newtons and void volume proximate to the inorganic filler.
Dependencies are inferred from the claim text.