HIGH-MOLECULAR MASS POLYESTER PRODUCTION PROCESS Russian patent published in 2006 - IPC C08G63/84 C08G63/183 C08G63/189 

FIELD: polymer production.

SUBSTANCE: invention relates to production of high-molecular mass polyesters for use as fiber-optic cable shell material and as extrusive structural and insulation materials. High-molecular mass (co)polyesters of invention are prepared via reaction terephthalic and/or 2,6-naphthalenedicarboxylic acid dimethyl ester with 1,4-butanediol and/or ethylene glycol, or reaction of above ester mixture with oligotetramethylene oxide in melt at 150-250°C in presence of boric acid or boric anhydride, or sodium borate, or mixture thereof with tetrabutoxytitanium. As thermostabilizer, synergetic mixture of pentaerythrityl-tetrakis(3.5-di-tert-butyl-4-hydroxyphenyl) propionate (sterically hindered tetraphenol) (0.1%), trinonylphenyl phosphite or tri(2,4-di-tert-butylphenyl) phosphite (0.35%), and hypophosphorous acid sodium or calcium salt (0.05%) is used, all percentages being based on the weight of (co)polyester. In the second stage, first-stage product is subjected to polycondensation at 220-290°C and residual pressure 0.1 mm Hg. Second-stage polyester product is finally subjected to solid-phase polycondensation at 200-250°C.

EFFECT: enabled production of high-molecular mass polyesters and increased temperature resistance of melt during extrusion treatment.

1 dwg, 1 tbl, 14 ex