Copolyamide compositions with reduced crystallization rates
A copolyamide composition comprising a statistical copolyamide containing 70-99 wt % of diamine and dicarboxylic acid repeat units and 1-30 wt % of lactam or AA-BB repeat units, whereby incorporation of the comonomer lactam or AA-BB unit reduces the crystallization rate (longer crystallization times) while maintaining (1) high melting point, (2) low potential plate out, (3) low oxygen permeation, (4) high tensile strength and (5) puncture/tear resistance.
1. A copolyamide composition of Formula (3)
wherein in Formula (3):
c=90 wt %;
d=2-5, 7-16
e=10 wt %;
wherein the copolyamide composition has:
a number average molecular weight Mn of greater than 18,000 g/mol,
a relative viscosity according to ASTM D789 (9.34) in a range of 90-230, and
a melting point greater than 220° C.
2. The copolyamide composition according to claim 1 , wherein a first repeating diamine and dicarboxylic acid unit is PA66.
3. The copolyamide composition according to claim 1 , wherein the copolyamide composition has a delta end group value from 1 to 50 μeq.
4. The copolyamide composition according to claim 1 , wherein the copolyamide composition has an amine end group value from 5 to 79 μeq.
5. A film comprising the copolyamide composition according to claim 1 , wherein the film is one of a cast film, a blown film, and a biaxially oriented film.
6. A process for making a film comprising casting the copolyamide composition of claim 1 to make a cast film.
7. The process according to claim 6 , wherein casting includes melting pellets through a single screw extruder at a temperature of between 250° C. and 300° C. to form melted pellets, extruding the melted pellets through a slip die, and rolling onto a chilled roll through winding to form a cast film.
8. The process according to claim 6 , wherein the cast film has a stretch ratio of at least about 2.9× in the machine direction and at least about 3× in the transverse direction, and wherein the cast film demonstrates:
a puncture resistance according to ASTM F1306 of greater than 1770 N/mm, and
an elongation at break (machine direction) according to ASTM D882 of at least 75%.