Process for the production of high molecular weight polyester resins
AssigneeM. & G. Ricerche S.p.A.
InventorGuido Ghisolfi
Life of this patent
Estimating the term…
Abstract
A process for the solid state polyaddition of a polyester resin in which the resin, blended in a molten state with a dianhydride of an aromatic tetracarboxylic acid is granulated, crystallized and then upgraded, characterized in that the crystallization and upgrading temperature is comprised in the range between the TG and 170.degree. C., preferably between 130.degree. and 170.degree. C.
Claims8
Process for the continuous production of high molecular weight polyester resin from polyester resin having a lower molecular weight, comprising the steps of blending the resin in a molten state with an additive selected from the group of the dianhydrides of the aromatic tetracarboxylic acids, granulating the resin, subjecting the granules first to crystallization and then to solid state polyaddition, characterized in that the crystallization and the polyaddition steps are carried out at a temperature comprised between the TG of the resin and 170.degree. C.
Dependencies are inferred from the claim text.