Abstract Copolyesters of poly(ethylene terephthalate) modified with greater than 10 to about 40 mol % trans-4,4'-stil-benedicarboxylic acid can be melt spun to give as-spun fibers with exceptionally low shrinkage at elevated temperatures and with tensile strengths and moduli equivalent to those of fully oriented poly(ethylene terephthalate). They may be drafted to give fibers with tenacities >8 g/den and moduli >150 g/den. In addition to the unobviously high tenacities and moduli of as-spun fibers, oriented shaped articles, such as films and bottles, of copolyesters of this invention have lower gas permeabilities than poly(ethylene terephthalate). For example, the oxygen permeability of these copolyesters is 25 to 50% lower than that of poly(ethylene terephthalate).
Oriented shaped article formed from a copolyester containing repeating units from less than 90 to about 60 mol % terephthalic acid, greater than 10 to about 40 mol % trans-4,4'-stilbenedicarboxylic acid and repeating units from ethylene glycol, said oriented shaped article being further characterized in that it has an oxygen permeability of less than 5 cc-mil/100 in 2 -24 hr-atm.
Claim 2
Dependent Claim
60 words
Oriented shaped article formed from a copolyester containing repeating units from less than 90 to about 60 mol % terephthalic acid, greater than 10 to about 40 mol % trans-4,4'-stilbenedicarboxylic acid and repeating units from ethylene glycol, said oriented shaped article being further characterized in that it has an oxygen permeability of less than 5 cc-mil/100 in 2 -24 hr-atm.
Claim 3
Dependent Claim
57 words
Oriented shaped article of claim 1 wherein the repeating units of terephthalic acid are present in the amount of 85 to 65 mol %, the repeating units from trans-4,4'-stilbenedicarboxylic acid are present in the amount of 15 to 35 mol % and the repeating units from ethylene glycol are present in the amount of 100 mol %.
Claim 4
Dependent Claim
43 words
Oriented shaped article of claim 1 wherein up to about 15 mol % or the repeating units from the terephthalic acid component of the copolyester are replaced with repeating units from at least one other dicarboxylic acid containing 3 to 20 carbon atoms.
Claim 5
Dependent Claim
38 words
Oriented shaped article of claim 1 wherein up to about 15 mol % of the repeating units of the ethylene glycol is replaced with repeating units from at least one other glycol containing 3 to 20 carbon atoms.
Claim 6
Dependent Claim
12 words
Oriented shaped article of claim 1 wherein said article is a film.
Claim 7
Dependent Claim
12 words
Oriented shaped article of claim 1 wherein said article is a bottle.