Copolyesterimides derived from N,N′-bis-(hydroxyalkyl)-benzophenone-3,3′,4,4′-tetracarboxylic diimide and films made therefrom
AssigneeDuPont Teijin Films U.S. Limited Partnership
InventorsStephen William Sankey, David Turner, Howard Colquhoun, Stephen Jones
Life of this patent
Estimating the term…
Abstract
A copolyester includes repeating units derived from an aliphatic glycol, terephthalic acid, and the monomer of formula (I): wherein n=2, 3 or 4; Z is C═O; comonomer (I) constitutes a proportion of the glycol fraction of the copolyester and is present in a range of from about 5 to about 15 mol % of the glycol fraction of the copolyester; wherein said copolyester is semi-crystalline. A process tor making the copolyester includes annealing a copolyester of formula (I) at 20-80° C. below the crystalline melting point (Tm) and above the glass transition temperature (Tg).
Claims19
A copolyester which comprises repeating units derived from an aliphatic glycol, terephthalic acid, and the monomer of formula (I):
- wherein n=2, 3 or 4;
- Z is C═O;
- comonomer (I) constitutes a proportion of the glycol fraction of the copolyester and is present in a range of from about 5 to about 15 mol % of the glycol fraction of the copolyester;
- wherein said copolyester is semi-crystalline.
A process for the-manufacture of a semi-crystalline copolyester, which comprises repeating units derived from, an aliphatic glycol, terephthalic acid, and the monomer of formula (I):
- wherein n=2, 3 or 4;
- Z is C═O;
- comonomer (I) constitutes a proportion of the glycol fraction of the copolyester and is present in a range of from about 5 to about 15 mol % of the glycol fraction of the copolyester;
- wherein the process comprises annealing a copolyester of formula (I) at 20-80° C. below the crystalline melting point (Tm) and above the glass transition temperature (Tg), to provide a semi-crystalline copolyester of formula (I).
Dependencies are inferred from the claim text.