Ann Marie Corey

6441129, Aug 27, 2002

May 15, 2001

09/858171

Ben Duh - Tallmadge OH
Ann Marie Corey - Akron OH

Shell Oil Company - Houston TX

C08F 600

528503, 528302, 528308, 5283086, 528481

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 225Â C. , preferably 210 to 225Â C. In one embodiment of the present invention, the temperature range is 200 to 220Â 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 225Â 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.

6461575, Oct 8, 2002

May 11, 1999

09/309921

Ben Duh - Tallmadge OH
Ye-Mon Chen - Sugar Land TX
Ann Marie Corey - Akron OH

Shell Oil Company - Houston TX

B01D 900

4222451

The pelletized product of melt condensation polymerization of 1,3-propanediol and terephthalic acid is crystallized in a vessel designed for continuous fluidized bed flow of the pellets in water at a temperature within the range of about 65 to about 100Â C. Hot-water treatment in the vessel permits crystallization of the pellets in a continuous operation and results in an increase of the crystallinity of the polymer to greater than about 35% and an increase in pellet density.

62973150, Oct 2, 2001

May 11, 1999

9/309923

Ben Duh - Tallmadge OH
Ye-Mon Chen - Sugar Land TX
Ann Marie Corey - Akron OH

Shell Oil Company - Houston TX

C08L 6702

524605

The pelletized product of melt condensation polymerization of 1,3-propanediol and terephthalic acid (or alkyl ester thereof) is crystallized by immersion in water at a temperature within the range of 60 to about 100. degree. C. Hot-water treatment increases the crystallinity of the polymer to at least about 35% and increases pellet density to about 1. 33 g/cm. sup. 3.