Naphthenic-rich liquid crystalline polymer composition with improved flammability performance

摘要

A thermoplastic composition that comprises a naphthenic-rich, thermotropic liquid crystalline polymer blended with a flow modifier is provided. The flow modifier is an aromatic carboxylic acid that contains or more carboxyl functional groups. Without intending to be limited by theory, it is believed that the functional groups can react with the polymer chain to shorten its length and thus reduce melt viscosity. It is also believed that such acids can combine smaller chains of the polymer together after they have been cut during processing. This helps maintain the mechanical properties of the composition even after its melt viscosity has been reduced. As a result of the present invention, the melt viscosity of the thermoplastic composition is generally low enough so that it can readily flow into the cavity of a mold having small dimensions.

主权项

1. A molded part comprising a thermoplastic composition, wherein the thermoplastic composition comprises at least one aromatic carboxylic acid and at least one thermotropic liquid crystalline polymer having a total amount of repeating units derived from naphthenic hydroxycarboxylic and/or naphthenic dicarboxylic acids of more than 18 mol. %, wherein the thermoplastic composition has a melt viscosity of from about 0.1 to about 80 Pa·s, as determined in accordance with ISO Test No. 11443 at a shear rate of 1000 seconds−1 and temperature that is 15° C. above the melting temperature of the thermoplastic composition, wherein the molded part exhibits a total flame time of about 50 seconds or less, as determined in accordance with UL94 at a thickness of 0.8 mm after conditioning for 48 hours at 23° C. and 50% relative humidity.