Polycondensation catalyst for producing polyester and production of polyester using the same

Patent metadata

Field	Value
Publication number	US-11612882-B2
Application number	US-201816769313-A
Country	US
Kind code	B2
Filing date	Dec 11, 2018
Priority date	Dec 22, 2017
Publication date	Mar 28, 2023
Grant date	Mar 28, 2023

Abstract

The invention provides a polycondensation catalyst for producing polyester by an esterification reaction or a transesterification reaction of a dicarboxylic acid or an ester-forming derivative thereof and a glycol, wherein the polycondensation catalyst comprises particles of a water-insoluble or hardly water-soluble phosphate having on the surfaces a coating layer of titanic acid in an amount, of 0.1 to 100 parts by weight in terms of TiO 2 per 100 parts by weight of the phosphate.

First claim

The invention claimed is:

1. A polycondensation catalyst for producing polyester by an esterification reaction or a transesterification reaction of a dicarboxylic acid or a dialkyl ester thereof and a glycol,
wherein the polycondensation catalyst comprises particles of a water-insoluble or hardly water-soluble phosphate having on a surface thereof a coating layer of titanic acid in an amount of 0.1 to 100 parts by weight in terms of TiO 2 per 100 parts by weight of the phosphate, and
wherein a maximum amount of the phosphate that is soluble in 100 g of water at a temperature of 25° C. is 2.00 g or less.

2. The polycondensation catalyst according to claim 1 , wherein the phosphate is an orthophosphate, a metaphosphate, a pyrophosphate, a phosphate glass, a phosphite or a hypophosphite, and
a counter ion of the phosphate anion is at least one cation of a metal selected from the group consisting of alkaline earth metals, aluminum, titanium, zirconium, and zinc.

3. The polycondensation catalyst according to claim 2 , wherein the alkaline earth metal is calcium or magnesium.

4. The polycondensation catalyst according to claim 1 , wherein the phosphate is dibasic calcium phosphate, tribasic calcium phosphate, calcium pyrophosphate, calcium dihydrogenpyrophosphate, magnesium pyrophosphate or magnesium metaphosphate.

5. The polycondensation catalyst according to claim 1 , wherein the particles of the phosphate have on the surface thereof the coating layer formed of titanic acid in the amount of 1 to 50 parts by weight in terms of TiO 2 per 100 parts by weight of phosphate.

6. A method for producing polyester, comprising subjecting a dicarboxylic acid or a dialkyl ester thereof and a glycol to polycondensation by an esterification reaction or a transesterification reaction in the presence of the polycondensation catalyst according to claim 1 .

7. A method for producing polyester comprising preparing oligomers containing a bis(hydroxyalkyl) ester of an aromatic dicarboxylic acid by an esterification reaction or a transesterification reaction of the aromatic dicarboxylic acid or a dialkyl ester thereof and an alkylene glycol, and then subjecting the oligomers to melt-polycondensation in the presence of the polycondensation catalyst according to claim 1 .

8. A method for producing polyester comprising subjecting a dicarboxylic acid or a dialkyl ester thereof and a glycol to polycondensation by an esterification reaction or a transesterification reaction in the presence of the polycondensation catalyst according to claim 1 , wherein the polycondensation catalyst is present in an amount of 1 to 40 ppm in terms of titanium atom based on a weight of the polyester.

9. A method for producing polyester comprising preparing oligomers containing a bis(hydroxyalkyl) ester of an aromatic dicarboxylic acid by an esterification reaction or a transesterification reaction of the aromatic dicarboxylic acid or a dialkyl ester thereof and an alkylene glycol, and then subjecting the oligomers to melt-polycondensation in the presence of the polycondensation catalyst according to claim 1 , wherein the polycondensation catalyst is present in an amount of 1 to 40 ppm in terms of titanium atom based on a weight of the polyester.

10. A method for producing the polycondensation catalyst for producing polyester according to claim 1 , comprising:
while maintaining a water slurry containing water-insoluble or hardly water-soluble particles of a phosphate at a temperature in a range of 5 to 100° C., adding to the water slurry a titanium compound in an amount of 0.1 to 100 parts by weight in terms of TiO 2 relative to 100 parts by weight of the phosphate, and adding an alkali to the resulting mixture to hydrolyze the titanium compound at a pH in a range of 3 to 12 to form a coating layer of titanic acid on surfaces of the particles of the phosphate; and
drying and disintegrating the particles of the phosphate having the coating layer on the surfaces,
wherein a maximum amount of the phosphate that is soluble in 100 g of water at a temperature of 25° C. is 2.00 g or less.

Assignees

• Sakai Chemical Industry Co

Inventors

• SOGA Yuhei
• Kamon Akihiro

Classifications

• C08K2003/321

  Phosphates · CPC title

• C08G63/80

  Solid-state polycondensation · CPC title

• B01J27/1806 Primary

  with alkaline or alkaline earth metals · CPC title

• C08K2003/325

  Calcium, strontium or barium phosphate · CPC title

• C08K3/24

  Acids; Salts thereof {(C08K3/16 takes precedence)} · CPC title