High strength polyethylene terephthalate yarn and cord produced therefrom

Claim 2

A polyethylene terephthalate filamentary cord made from polyethylene polymer consisting of two or more yarns twisted together in which the intrinsic viscosity of the polymer is at least 0.90 0.91 dl. per gram and which have uniform properties of breaking strength in pounds of at least about 69, an elongation at break in percent of at least about 18, a translational efficiency in percent of at least about 87, a toughness index in grams centimeter per denier centimeter of at least about 0.72, and a shrinkage in percent not greater than about 5.

Claim 3

Polyethylene terephthalate cord according to claim 3 in the form of rubber reinforcements.

Claim 4

A vulcanized rubber article reinforced with a polyethylene terephthalate fibrous structure consisting essentially of having an intrinsic viscosity of at least 0.90 dl. per gram and which have uniform properties of breaking strength in pounds of at least about 69, an elongation at break in percent of at least about 18, a translational efficiency of at least about 87, a toughness index in grams centimeter per denier centimeter of at least about 0.72, and a shrinkage in percent not greater than about 5.

Claim 5

In a pneumatic tire including a tread member, inextensible beads, and a body member, the improvement which consists essentially of a plurality of plies of tire cord fabric embedded in rubber, said fabric being prepared from yarn of a linear terephthalate polyester having an intrinsic viscosity of at least 0.90 dl. per gram and which have uniform properties of breaking strength in pounds of at least about 69, an elongation at break in percent of at least about 18, a translational efficiency of at least about 87, a toughness index in grams centimeter per denier centimeter of at least about 0.72, and a shrinkage in percent not greater than about 5.

Claim 6

An improved industrial yarn characterized by resistance to thermal degradation when embedded in rubber consisting essentially of filaments of a linear terephthalate polyester having an intrinsic viscosity of at least 0.90 dl. per gram and which have uniform properties of breaking strength in pounds of at least about 69, an elongation at break in percent of at least about 18, a translational efficiency of at least about 87, a toughness index in grams centimeter per denier centimeter of at least about 0.72, and a shrinkage in percent not greater than about 5.