Process for the production of high molecular weight polyester
AssigneeThe Goodyear Tire & Rubber Company
InventorBen Duh
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Abstract
A process for the continuous production of high molecular weight polyethylene terephthalate wherein the crystallized prepolymer having an intrinsic viscosity of at least 0.3 is dried, preheated and polymerized in a single moving bed reaction zone. The method is characterized by an inert gas atmosphere and a reaction zone with a temperature gradiant ranging from about 170.degree. C. at the uppermost portion and a higher temperature of about 225.degree. C. at the lowermost portion.
Claims3
In a process for the continuous solid state polymerization of crystalline linear polyester prepolymer wherein the crystalline polyester is further polymerized, the improvement comprising introducing a crystalline linear polyester prepolymer having an appreciable moisture content to a single moving bed reaction zone, countercurrently contacting said polyester within the reaction zone with a heated inert gas wherein the temperature of the crystalline polyester is increased from about 170.degree. C. to its polymerization temperature of about 200.degree. C. to 225.degree. C. whereby said polyester is further polymerized in its crystalline form without severe degradation of the polyester.
A method for the solid state polymerization of polyester resins comprising heating a crystallized prepolymer into a single moving bed reaction zone for a time sufficient to dry and solid state polymerize the polyester to a desirable I.V. wihtout severe degradation due to a high moisture content of the polyester, wherein there is a temperature gradiant of from 170.degree. C. at the uppermost section to about 225.degree. C. at the lowermost section.
A method for the solid state polymerization of polyethylene terephthalate comprising feeding a crystalline polyethylene terephthalate characterized by an I.V. of at least 0.3 and an initial moisture content of up to 0.35 percent by weight, into a single moving bed reaction zone wherein said zone there is a counter-current flow of hot inert gas and there is a temperature gradiant of from about 170.degree. C. at the upper most section of said zone and from about 225.degree. C. at the lower most section of said zone.
Dependencies are inferred from the claim text.