Thermally stable polyester, process for its preparation and its use
AssigneeInvista Technologies S.A R.L.
InventorsUwe Bayer, Jürgen Popp, Thomas Wehrmeister
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Abstract
A polyester with a carbon black content of up to 20% by weight, based on the polyester, is condensed, after transesterification of DMT with diol, or after esterification of terephthalic acid with diol, with the aid of a titanium-based catalyst. The carbon black is added in the form of a carbon black dispersion together with the polycondensation catalyst to the transesterification product or esterification product. The carbon black dispersion comprises gas black or furnace black and a dispersing agent, and these are dispersed in diol. The diameter of the carbon black particles is below that of carbon black particles in a polyester using an antimony compound as catalyst.
Claims32
A thermally stable polyester resin comprising:
- polyester;
- from 1 to 100 ppm of titanium, in the form of a titanium compound, as a polycondensation catalyst, based on the amount of polyester;
- from 0.01 to 20% by weight of agglomerated carbon black, based on the weight of the polyester;
- and from 0 to 200 ppm of phosphorous, in the form of a phosphorous compound, based on the amount of polyester.
A process for preparing a polyester comprising:
- reacting dimethyl terephthalate and a lower-aliphatic diol or, respectively, terephthalic acid and a lower-aliphatic diol to produce a prepolymer blend;
- polycondensing said prepolymer blend with the aid of a Ti compound as polycondensation catalyst, admixing from 0.01 to 20% by weight of carbon black, based on the weight of the polyester, which has been dispersed in a lower-aliphatic diol together with a dispersing agent, and optionally mixing phosphorus-containing compounds as additives with the other components of the reaction.
Dependencies are inferred from the claim text.