摘要 |
A poly(trimethylene terephthalate) polymer composition (a) comprising repeat units derived from terephthalic acid and 1,3- propanediol, (b) having a b value of less than about 10, and (c) having an intrinsic viscosity (IV) in the range from about 0.74 to about 2.0. The poly(trimethylene terephthalate) polymer composition does not contain a blue masking pigment. It is prepared by a process comnprising contacting, in the presence of a catalyst comprises tin and titanium. A copolymer that contains up to 20 mole percent of another acid and/or a second alcohol is also disclosed. Further disclosed is a composition of, or comprising, a bis (3-hydroxypropyl) terephthalalte prepolymer. The bis (3-hydroxypropyl) terephthalalte prepolymer and poly(trimethylene terephthalalte) can each contain 10 to 100 ppm tin and 10 to 200 ppm titanium relative to the terephthalic acid content.
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