| Title: SELF REINFORCED THERMOPLASTIC COMPOSITE LAMINATE Inventor(s):
A. Isayev
Disclosure 163 U.S. Patent 5,268,225
Disclosure 163-DIV U.S. Patent 5,238,638
Composite laminates are prepared from thin sheets of thermotropic liquid crystal
polymer blends. A preferred blend contains 2 thermotropic liquid crystal polymers i.e., a
first liquid crystal polymer in LCP-1, and a second liquid crystal polymer (LCP-2), the
second liquid crystal polymer having a higher melting point than the first. The second
liquid crystal polymer is molecularly oriented and is preferably at least partially in the
form of microscopic fibers in a matrix of the first liquid crystal polymer. The two liquid
crystal polymers are phase separated in the solid phase and have overlapping melt
processing temperatures.
The laminates may be formed so that the direction of molecular orientation is either
the same in all layers or different in successive layers. The blends give composites
having mechanical properties, e.g., tensile strength and secant modulus, which are as good
or nearly as good (and in some cases better than) those of either pure LCP, at
substantially lower cost. The process of this invention saves energy than those processes
required to form otherwise similar laminates containing preformed reinforced fibers.
This technology is ideally suited for automotive (i.e. bodies), aircraft and marine
(i.e. hulls) industries. In general, composites of this invention are useful in making
articles or parts where high tensile strength, high modulus and/or high impact strength
are advantageous, particularly where reasons of weight reduction it is desirable to use
reinforced plastic instead of metal. |
