Aromatic copolyester capable of forming an optically anisotropic melt
AssigneeE. I. Du Pont de Nemours and Company
InventorJohn Raymond Schaefgen
Life of this patent
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Abstract
This invention relates to a class of synthetic polyesters and copolyesters which display optical anisotrophy in the molten state and to the fibers, films, and other shaped articles obtained from the optically anisotropic melts.
Claims20
A fiber-forming, melt spinnable (co) polyester capable of forming an optically anisotropic melt and consisting essentially of recurring units selected from the group consisting of ##STR52## wherein units I and II are present in substantially equimolar amounts;
- R.sub.1 and R.sub.2 are radicals selected from the group of 1) single and fused siz-membered aromatic carbocyclic ring systems wherein the chain extending bonds of the ring system, if attached to the same ring, are positioned 1,4- to each other, and if attached to different rings, are in positions parallel and oppositely directed, and 2) multiple six-membered aromatic carbocyclic ring systems in which the individual rings are joined by a chemical bond or a trans-vinylene group, and in which the chain extending bonds of each ring are in the 1,4-positions;
- and with the proviso that R.sub.2 is unsubstituted in homopolymers of units I and II, said (co)polyester having a flow temperature in the range of 200.degree. C to 375.degree. C.
A fiber-forming, melt spinnable copolyester capable of forming an optically anisotropic melt and consisting essentially of recurring units selected from the group consisting of ##STR62## wherein R.sub.1 and R.sub.2 are radicals selected from the group of 1) single and fused six-membered aromatic carbocyclic ring systems wherein the chain extending bonds of the ring system, if attached to the same ring, are positioned 1,4- to each other, and if attached to different rings, are in positions parallel and oppositely directed, and 2) multiple six-membered aromatic carbocyclic rings systems in which the individual rings are joined by a chemical bond or a trans-vinylene group, and in which the chain extending bonds of each ring are in the 1,4-positions;
- and with the proviso that R.sub.1 is substituted, and up to 25 mol % of other aromatic polyester-forming units based on the total of such units I and II and wherein the I units and their replacements and the II units and their replacements are present in substantially equimolar amounts, said copolyester having a flow temperature in the range of 200.degree. C to 375.degree. C.
Dependencies are inferred from the claim text.