Process for heat treating shaped articles of poly {[benzo(1,2-d:4,5-d')bisthiazole-2,6-diyl]-1,4-phenylene}, its cis isomer or mixtures thereof
AssigneeCelanese Corporation
InventorEdward C. Chenevey
Life of this patent
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Abstract
The properties of shaped articles of poly {[benzo(1,2-d:4,5-d')bisthiazole-2,6-diyl]-1,4-phenylene}, its cis isomer and mixtures thereof are improved by a process of heat treatment under tension. The articles may be prepared from a dope obtained by dissolving the formed polymer in an appropriate solvent or by forming the polymer under conditions which enable the article to be prepared directly from the reaction medium.
Claims12
A process for heat treating a shaped article of poly{[benzo(1,2-d:4,5-d')bisthiazole-2,6-diyl]-1,4-phenylene}, its cis isomer or mixtures thereof on a continuous basis comprising:
- (a) heating the article to a temperature in the range of from about 375.degree. to about 650.degree. C.;
- (b) stretching the article to obtain a stretch of from about 0.5 to about 4%;
- and
- (c) maintaining the article under the conditions of (a) and (b) for from about 5 to about 300 seconds.
A process for preparing heat treated shaped articles of poly{[benzo(1,2-d:4,5-d')bisthiazole-2,6-diyl]-1,4-phenylene}, its cis isomer or mixtures thereof on a continuous basis comprising:
- (a) dissolving ##STR8## in polyphosphoric acid in about equimolar amounts of (i) to (ii);
- (b) reacting (i) and (ii) at a temperature in the range of from about 150.degree. to about 200.degree. C. to obtain a polymer having the recurring unit ##STR9## or mixtures thereof;
- (c) forming a shaped article from the polymer;
- (d) heating the article to a temperature in the range of from about 375.degree. to about 650.degree. C.;
- (e) stretching the article to obtain a stretch of from about 0.5 to about 4% and
- (f) maintaining the article under the conditions of (d) and (e) for from about 5 to about 300 seconds.
Dependencies are inferred from the claim text.