Patent ID: 6027771
Filing Date: 2000-02-22
Classification: B29C,B32B,C09K,H05K,Y10S,Y10T

Abstract:
A composite material comprising:(a) a first support membrane of synthetic polymer;(b) a nonporous stretched oriented film comprising a mixture of liquid crystal polymer and solid particulate material;said film containing sufficient solid particulate material to reduce thickness variability whereby the ratio of the standard deviation of thickness values to the mean thickness value of the film is 0.1 or less;(c) a second support membrane of synthetic polymer;said first and second support membranes and said nonporous stretched oriented film adhered together in laminar relationship to form a composite material having a sandwich structure comprising said nonporous stretched oriented film between said support membranes;said composite material being stretched in at least one direction to multiaxially orient the liquid crystal polymer of said nonporous stretched oriented film;said nonporous stretched multiaxially oriented film comprising a mixture of liquid crystal polymer and solid particulate material having substantially equal values in at least one physical property selected from the group consisting of tensile strength, tensile elongation, and thermal expansion, in the direction of stretch and in the direction normal to the direction of stretch; and wherein the ratio of the standard deviation of thickness values to the mean thickness value of the film is 0.1 or less.