Patent ID: 7338692
Filing Date: 2008-03-04
Classification: B01D,C08J,H01M,Y02E,Y02P,Y10T

Abstract:
1. A shaped article comprising: a) polyvinylidene fluoride or copolymers thereof; b) a sufficient quantity of nanometer-sized nucleating agent to initiate crystallization of the polyvinylidene fluoride or copolymers thereof at a significantly greater number of crystallization sites as compared to crystallization without the nucleating agent; c) a diluent with which the polyvinylidene fluoride or copolymers thereof are miscible, and in which the polyvinylidene fluoride or copolymers thereof will dissolve at or above the melting temperature of the polyvinylidene fluoride or copolymers thereof, and will phase separate upon cooling to a temperature at or below the crystallization or phase separation temperature of the polyvinylidene fluoride or copolymers thereof; wherein the diluent is glyceryl triacetate; wherein the shaped article is microporous and has been oriented in at least one direction at a stretch ratio of at least approximately 1.1 to 1.0; and wherein the sufficient quantity of nucleating agent is between approximately 0.2 percent to approximately 2.5 percent by weight of the polyvinylidene fluoride or copolymers thereof.