Method for producing ο-phthalate polyester polyols with low cyclic ester content

Patent metadata

Field	Value
Publication number	US-9487467-B2
Application number	US-201214004887-A
Country	US
Kind code	B2
Filing date	Mar 7, 2012
Priority date	Mar 16, 2011
Publication date	Nov 8, 2016
Grant date	Nov 8, 2016

Abstract

A method for producing a polyester polyol is disclosed. The method comprises reacting phthalic anhydride with a diol selected from the group consisting of ethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 1,6-hexanediol, polyethylene glycols having a number average molecular weight within the range of 200 g/mol to 600 g/mol, and mixtures thereof at a diol to phthalic anhydride molar ratio within the range of 1.1 to 1.6. The resulting o-phthalate polyester polyol has a hydroxyl value in the range of 18 to 400 mg KOH/g, an acid value in the range of 0.2 to 5.0 mg KOH/g, and 1 wt. % or less of cyclic esters.

First claim

We claim:

1. A method which comprises reacting phthalic anhydride with a diol selected from the group consisting of propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, neopentyl glycol, polyethylene glycols having a number average molecular weight within the range of 200 g/mol to 600 g/mol, mixtures of ethylene glycol and at least one polyethylene glycol having a number average molecular weight within the range of 200 g/mol to 600 g/mol, and mixtures thereof in the presence of a catalyst comprising titanium at a diol to phthalic anhydride molar ratio within the range of 1.1:1 to 1.6:1 to produce an o-phthalate polyester polyol having a hydroxyl value in the range of 18 to 400 mg KOH/g, an acid value in the range of 0.2 to 5.0 mg KOH/g, and 1 wt. % or less of cyclic esters.

2. The method of claim 1 wherein the molar ratio of ethylene glycol to polyethylene glycol is within the range of 0.2:1 to 3.0:1.

3. The method of claim 1 wherein the polyethylene glycol in said mixtures of ethylene glycol and at least one polyethylene glycol has a number average molecular weight within the range of 250 to 400 g/mol.

4. The method of claim 1 wherein the molar ratio of diol to phthalic anhydride is within the range of 1.1:1 to 1.4:1.

5. The method of claim 1 wherein the polyester polyol has a hydroxyl value within the range of 56 to 320 mg KOH/g.

6. The method of claim 1 wherein the polyester polyol has an acid value within the range of 0.5 to 3.0 mg KOH/g.

7. The method of claim 1 wherein the charged amount of phthalic anhydride is at least 30 wt. % based on the combined amounts of diol and phthalic anhydride.

8. The method of claim 1 wherein the charged amount of phthalic anhydride is within the range of 35 to 70 wt. % based on the combined amounts of diol and phthalic anhydride.

9. The method of claim 1 wherein the polyester polyol has a number average molecular weight within the range of 500 to 2000 g/mol.

10. The method of claim 1 wherein 0.5 wt. % or less of cyclic esters are produced based on the amount of polyester polyol.

11. The method of claim 1 wherein 0.2 wt. % or less of cyclic esters are produced based on the amount of polyester polyol.

12. The method of claim 1 wherein phthalic anhydride and diol are reacted in the presence of a natural oil.

13. A one- or two-component polyurethane adhesive made with a polyester polyol produced by the method of claim 1 .

14. A polyurethane coating, sealant, elastomer, flexible foam, or rigid foam made with a polyester polyol produced by the method of claim 1 .

Assignees

• Hillshafer Douglas
• Guo Andrew
• Stepan Co

Inventors

• Hillshafer Douglas
• Guo Andrew

Classifications

• C08G18/4252

  derived from polyols containing polyether groups and polycarboxylic acids · CPC title

• C08G18/4211

  derived from aromatic dicarboxylic acids and dialcohols · CPC title

• C08G63/181 Primary

  Acids containing aromatic rings · CPC title

• C09J175/06

  from polyesters · CPC title

• C09D175/06

  from polyesters · CPC title