Aqueous polyurethane dispersion comprising a terephthalic acid polyester

Patent metadata

Field	Value
Publication number	US-9790317-B2
Application number	US-201314416688-A
Country	US
Kind code	B2
Filing date	Jul 23, 2013
Priority date	Jul 26, 2012
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

The present invention relates to an aqueous polyurethane dispersion obtainable by the reaction of at least: (A) one polyisocyanate with two or more isocyanate groups, (B) one polyester component comprising (B1) a polyesterpolyol with a mean molecular weight of 300 to 900 g/Mol, having structural units derived from terephthalic acid, (C) one ionic group introducing compound with at least one sulphonate and/or carboxylate group and at least one isocyanate reactive group, (D) one diol with a mean molecular weight of 62 to 400 g/Mol, (E) one polyol with a mean molecular weight of 62 to 400 g/Mol, having three or more hydroxyl groups, (F) one amino functional and/or aminohydroxyl functional compound, its use to coat a substrate and a coating obtained by using the dispersion.

First claim

The invention claimed is:

1. An aqueous polyurethane dispersion obtained by the reaction of at least:
(A) 30 to 60% per weight of one polyisocyanate with two or more isocyanate groups,
(B) 15 to 50% per weight of one polyester component comprising
(B1) a polyesterpolyol with a weight average molecular weight of 300 to 900 g/Mol, comprises structural units derived from derived from 3-methyl-1,5 pentandiol,

(C) 1.5 to 8% per weight of one ionic group introducing compound with at least one sulphonate and/or carboxylate group and at least one isocyanate reactive group,
(D) 1 to 8% per weight of one diol with a weight average molecular weight of 62 to 400 g/Mol,
(E) 0.1 to 4% per weight of one polyol with a weight average molecular weight of 62 to 400 g/Mol, having three or more hydroxyl groups,
(F) 0.5 to 12% per weight of one amino functional and/or aminohydroxyl functional compound, wherein the sum of all percentages adds up to 100.

2. The dispersion according to claim 1 , wherein the weight average molecular weight of the polyesterpolyol (B1) is 400 to 800.

3. The dispersion according to claim 1 , wherein the polyol component (B) additionally comprises a polyesterpolyol (B2) with a weight average molecular weight of 1000 to 4000 g/Mol, having structural units derived from terephthalic acid.

4. The dispersion according to claim 3 , wherein the weight average molecular weight of the polyesterpolyol (B2) is 1500 to 3500.

5. The dispersion according to claim 3 , wherein the polyesterpolyol (B2) comprises structural units derived from 3-methyl-1,5 pentandiol.

6. The dispersion according to claim 3 , wherein the ratio between the polyesterpolyol (B1) and the polyesterpolyol (B2) is between 100:0 to 40:60.

7. The dispersion according to claim 1 , wherein the polyisocyanate (A) has two isocyanate groups.

8. The dispersion according to claim 1 , wherein the ionic group introducing compound (C) comprises N-(2-aminoethyl)-2-aminoethane sulphonate and/or dimethylol propionic acid.

9. The dispersion according to claim 1 , wherein the diol (D) comprises one or more compounds selected from the group consisting of ethanediol, di-ethyleneglycol, tri- ethyleneglycol, tetraethyleneglycol, 1,2-propanediol, di-propyleneglycol, tri-propyleneglycol, tetrapropyleneglycol, 1,3-propanediol, butanediol-1,4, butanedio-1,3, butanediol-2,3, pentanedio-1,5, hexanedio-1,6, 2,2-dimethyl-1,3-propanediol, 1,4-dihydroxycyclohexane, 1,4-dimethylolcyclohexane, octanedio-1,8, decanediol-1,10, dodecanediol-1,12, neopentylglycol, 1,4-cyclohexanediol, 1,4-cyclohexane-dimethanol, 1,4-, 1,3-, 1,2-dihydroxybenzene, 2,2-bis-(4-hydroxyphenyl)-propane (bisphenol (A)), and 3-Methyl-1,5-pentandiol.

10. The dispersion according to claim 1 , wherein the polyol (E) comprises one or more compounds selected from the group consisting of trimethylolpropane, glycerine, pentaerythrite, and dipenthaerytrite.

11. The dispersion according to claim 1 , wherein the amino functional and/or aminohydroxyl functional compound (F) comprises one or more compounds selected from the group consisting of 1,2-ethanediamine, 1-amino-3,3,5-trimethyl-5-aminomethyl-cyclohexane, diethylenetriamine, diethanolamine, ethanolamine, N-(2-hydroxyethyl)-ethylenediamine and N,N-bis(2-hydroxyethyl)-ethylenediamine.

12. A method comprising coating a substrate with the dispersion according to claim 1 .

13. A coating obtained by applying the dispersion according to claim 1 .

14. The dispersion according to claim 1 , wherein the polyisocyanate (A) comprises one or more compounds selected from the group consisting of hexamethylene diisocyanate, 1,4-diisocyanatocyclohexane, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane, 4,4′-diisocyanato-dicyclohexyl-methane, and 4,4′-diisocyanato-dicyclohexylpropane-(2,2).

Assignees

• Bayer Materialscience Ag
• Covestro Deutschland Ag

Inventors

• Nazaran Pantea
• Gertzmann Rolf
• Morita Hiroshi
• Makoto Nakao

Classifications

• C08G18/6644

  having at least three hydroxy groups · CPC title

• C08G18/664 Primary

  with compounds of group C08G18/3203 · CPC title

• C08G18/0828

  containing sulfonate groups or groups forming them · CPC title

• C08G18/6655

  with compounds of group C08G18/3271 · CPC title

• C08G18/758

  containing two or more cycloaliphatic rings · CPC title