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US 6,441,129 B2Granted
High temperature solid state polymerization of poly (trimethylene terephthalate)
AssigneeShell Oil Company
InventorsBen Duh, Ann Marie Corey
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AssigneeShell Oil Company
InventorsBen Duh, Ann Marie Corey
Estimating the term…
The present invention is a process for producing poly(trimethylene terephthalate) (PTT) at an increased solid state polymerization rate, wherein 1,3-propane diol and an aromatic acid or a dialkyl ester thereof are esterified or transesterified, the esterification or transesterification product is polycondensed, and the polycondensation product is pelletized and then subjected to continuous solid state polymerization at a temperature of 200 to 225° C., preferably 210 to 225° C. In one embodiment of the present invention, the temperature range is 200 to 220° C., and the pellet size of the polymer to be solid state polymerized is from 1.0 to 1.5 g/100. In another embodiment of the present invention, the solid state polymerization is carried out at 210 to 225° C. for from 1 to 20 hours and then the temperature is increased to above the initial melting point of the polymer to produce a PTT polymer with an intrinsic viscosity of 1.3 dl/g or greater.
A process for producing poly(trimethylene terephthalate) and achieving an increased solid state polymerization rate wherein 1,3-propanediol, and optionally other diols, and an aromatic acid or diester thereof are esterified or transesterified, the esterification or transesterification product is polycondensed to produce a prepolymer, and the prepolymer is subjected to continuous solid state polymerization at a temperature of 210 to 225° C. and then at a temperature above the normal melting point of the prepolymer for 1 to 20 hours to produce a polymer with an intrinsic viscosity of 1.3 d/g or greater using a prepolymer with an intrinsic viscosity from 0.50 to 0.70 dl/g.
A process for producing poly(trimethylene terephthalate) and achieving an increased solid state polymerization rate wherein 1,3-propanediol, and optionally other diols, and an aromatic acid or diester thereof are esterified or transesterified, the esterification or transesterification product is polycondensed to produce a prepolymer, and the prepolymer is subjected to batch solid state polymerization at a temperature of 210 to 225° C. and then at a temperature above the normal melting point of the prepolymer for 1 to 20 hours to produce a polymer with an intrinsic viscosity of 1.3 dl/g or greater using a prepolymer with an intrinsic viscosity from 0.50 to 0.70 dl/g.
Dependencies are inferred from the claim text.