Method for rapid spinning of a polybenzazole fiber
AssigneeThe Dow Chemical Company
InventorsSteven Rosenberg, George J. Quarderer, Jr., Ashish Sen, Masaru Nakagawa, Timothy L. Faley, Myrna Serrano, Yoshihiko Teramoto, Chieh-Chun Chau
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Abstract
Polybenzazole polymer dopes are spun through a spinneret having more than 2 per cm.sup.2, of orifices in relatively close proximity. The dope filaments formed, then pass through an air gap which has a temperature of 50.degree. to 100.degree. C. and a gas flow sufficient to uniformly reduce the temperature of the dope filaments. The filaments cool in the air gap and are then coagulated.
Claims4
A process for making a fiber made up of more than one filament from a liquid-crystalline dope that contains a solvent and a polybenzazole polymer which is polybenzoxazole, polybenzothiazole or a copolymer thereof, said process comprising the steps of:
- (1) spinning the dope at a temperature greater than 100.degree. C. through a spinneret that contains a plurality of orifices, wherein the density of orifices in the spinneret is at least 2.0 per cm.sup.2, whereby a plurality of dope filaments is formed;
- (2) drawing the dope filaments across an air gap that contains a gas at a temperature of 50.degree. C. to 100.degree. C., wherein the gas flows through the air gap at a rate sufficient to uniformly reduce the temperature of the dope filaments;
- (3) contacting the drawn dope filaments with a fluid such that the solvent is removed from the filaments, and;
- (4) conducting the process such that the filaments are combined into one or more fibers before, during or after the time said filaments are contacted with said fluid.
Dependencies are inferred from the claim text.