	US 12,104,013 B2
	Method for preparing polyesters
Eckhard Seidel, Frankfurt am Main (DE); and Rainer Linke, Butzbach (DE)
Assigned to Technip Zimmer GMBH, Frankfurt am Main (DE)
Appl. No. 16/630,943
Filed by TECHNIP ZIMMER GMBH, Frankfurt am Main (DE)
PCT Filed Jul. 17, 2017, PCT No. PCT/EP2017/068057 § 371(c)(1), (2) Date Jan. 14, 2020, PCT Pub. No. WO2019/015745, PCT Pub. Date Jan. 24, 2019.
Prior Publication US 2020/0157277 A1, May 21, 2020
Int. Cl. C08G 63/85 (2006.01); C08G 63/183 (2006.01); C08K 3/34 (2006.01)

CPC C08G 63/85 (2013.01) [C08G 63/183 (2013.01); C08K 3/34 (2013.01); C08K 2201/005 (2013.01)]

10 Claims

1. A process for preparing polyesters comprising reacting, a dicarboxylic acid with a diol, wherein the diol is exclusively butanediol, in the presence of a catalyst, wherein in the process an aluminosilicate is present and wherein the aluminosilicate is a 4A-type zeolite;

wherein the process comprises the steps of esterification, prepolycondensation and polycondensation; and

wherein the esterification is carried out with a concentration of the aluminosilica between 100 and 1000 ppm with respect to the final product.