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

Claim 2

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° to about 650° 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.

Claim 3

The process of claim 1 wherein the heating of the article is performed in substantially inert atmosphere.

Claim 4

The process of claim 2 wherein the heating of the article is performed in a substantially inert atmosphere composed of nitrogen.

Claim 5

The process of claim 1 wherein the poly{[benzo(1,2-d:4,5-d')bisthiazole-2,6-diyl]-1,4-phenylene}, its cis isomer or mixtures thereof is fully polymerized prior to heating the article.

Claim 6

The process of claim 1 wherein the heat treated article has a modulus in the range of from about 1000 to about 3000 g./den., a tenacity in the range of from about 12 to about 30 g./den. and an elongation in the range of from about 0.5 to about 2.0%.

Claim 7

The process of claim 1 wherein the article is heated to a temperature in the range of from about 450° to about 550° C. stretched to obtain a stretch of from about 1 to about 4% and maintained under those conditions for from about 30 to about 120 seconds.

Claim 8

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° to about 200° 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° to about 650° 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.

Claim 9

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° to about 200° 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° to about 650° 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.

Claim 10

The process of claim 7 wherein the reaction of (i) and (ii) is performed in a substantially inert atmosphere.

Claim 11

The process of claim 7 wherein the steps of (d), (e) and (f) are performed in a substantially inert atmosphere.

Claim 12

The process of claims 8 or 9 wherein the atmosphere is composed of nitrogen.

Claim 13

The process of claim 7 wherein the heat treated article has a modulus in the range of from about 1000 to about 3000 g./den., a tenacity in the range of from about 12 to about 30 g./den. and an elongation in the range of from about 0.5 to about 2.0%.

Claim 14

The process of claim 7 wherein the article is heated to a temperature in the range of from about 450 to about 550° C., stretched to obtain a stretch of from about 1 to about 4% and maintained under those conditions for from about 30 to about 120 seconds.