Abstract: This invention discloses a copolyester which has been found to be optically anisotropic in the melt and which readily undergoes melt processing to form quality fibers and molded articles. These copolyesters are particularly suitable for use in making tire cord which has an outstanding combination of properties including tenacity, modulus, toughness and flex life. This invention specifically reveals a copolyester which is comprised of repeat units which are derived from (A) at least one member selected from the group consisting of phenyl hydroquinone, hydroxy benzoic acid and hydroxy naphthoic acid; (B) at least one diol selected from the group consisting of 1,4-bis(4-hydroxycumyl) benzene, 1,3-bis(4-hydroxycumyl) benzene, alkyl substituted 1,4-bis(4-hydroxycumyl) benzene, and alkyl substituted 1,3-bis(4-hydroxycumyl) benzene; and (C) a diacid component which is comprised of terephthalic acid and optionally up to about 10 mole percent isophthalic acid.

Abstract: This invention discloses a copolyester which has been found to be optically anisotropic in the melt and which readily undergoes melt processing to form quality fibers and molded articles. These copolyesters are particularly suitable for use in making tire cord which has an outstanding combination of properties including tenacity, modulus, toughness and flex life. This invention specifically reveals a copolyester which is comprised of repeat units which are derived from (A) at least one member selected from the group consisting of phenyl hydroquinone, hydroxy benzoic acid and hydroxy naphthoic acid; (B) at least one diol selected from the group consisting of 1,4-bis(4-hydroxycumyl) benzene, 1,3-bis(4-hydroxycumyl) benzene, alkyl substituted 1,4-bis(4-hydroxycumyl) benzene, and alkyl substituted 1,3-bis(4-hydroxycumyl) benzene; and (C) a diacid component which is comprised of terephthalic acid and optionally up to about 10 mole percent isophthalic acid.