Polyurethane aqueous dispersion, adhesive, synthetic leather and paint

Patent metadata

Field	Value
Publication number	US-12473392-B2
Application number	US-202318860460-A
Country	US
Kind code	B2
Filing date	Apr 7, 2023
Priority date	Apr 28, 2022
Publication date	Nov 18, 2025
Grant date	Nov 18, 2025

Abstract

There is provided an aqueous polyurethane dispersion that makes it possible to prepare an adhesive, a paint, and the like capable of forming an adhesion layer as a cured film whose physical properties such as strength are unlikely to be changed even by a change in temperature, the aqueous polyurethane dispersion having excellent storage stability. The aqueous polyurethane dispersion is an aqueous polyurethane dispersion containing: resin particles formed with a polyurethane having a hydroxy group at a terminal thereof; and water as a dispersion medium, wherein the polyurethane has a structure derived from a urethane prepolymer, the urethane prepolymer has a constituent unit derived from a polyol containing a polyether polyol; a constituent unit derived from a polyisocyanate containing an aliphatic polyisocyanate and an alicyclic polyisocyanate; and a constituent unit derived from an acidic group-containing polyol, the polyurethane has an acid value of 30 mgKOH/g or lower, the polyol further contains a polycarbonate polyol, and the mass ratio of the polyether polyol (C) to the polycarbonate polyol (D), (C):(D), is 20:80 to 95:5.

First claim

The invention claimed is:

1 . An aqueous polyurethane dispersion comprising:
resin particles formed with a polyurethane having a hydroxy group at a terminal thereof; and water as a dispersion medium, wherein the polyurethane has a structure derived from a urethane prepolymer, the urethane prepolymer comprises:
a constituent unit derived from a polyol, the polyol comprising:
a polyether polyol,
a polycarbonate polyol, and
an acidic group-containing polyol; and

a constituent unit derived from a polyisocyanate comprising an aliphatic polyisocyanate and an alicyclic polyisocyanate,
the polyurethane has an acid value of 30 mgKOH/g or lower, the polyurethane has a hydroxyl value in a range from 0.5 mg/KOH/g to 35.9 mgKOH/g, and the mass ratio of the polyether polyol (C) to the polycarbonate polyol (D), (C): (D), is in a range from 20:80 to 95:5.

2 . The aqueous polyurethane dispersion according to claim 1 , wherein
the urethane prepolymer is a reaction product having an isocyanate group at a terminal thereof, the reaction product obtained by reacting the polyisocyanate and the polyol in a ratio of an isocyanate group (NCO group) in the polyisocyanate to a hydroxy group (OH group) in the polyol, [NCO group/OH group (molar ratio)], of larger than 1, and the polyurethane is a reaction product obtained by reacting the urethane prepolymer and an alkanolamine.

3 . The aqueous polyurethane dispersion according to claim 2 , wherein the polyurethane is a reaction product obtained by reacting 10 mol % or more of the alkanolamine based on the amount of isocyanate group in the urethane prepolymer.

4 . The aqueous polyurethane dispersion according to claim 2 , wherein the alkanolamine is an alkanolmonoamine.

5 . The aqueous polyurethane dispersion according to claim 2 , wherein the urethane prepolymer is a reaction product obtained by reacting the polyisocyanate and the polyol in a ratio of the isocyanate group (NCO group) in the polyisocyanate to the hydroxy group (OH group) in the polyol, [NCO group/OH group (molar ratio)], of larger than 1 but not exceeding 1.7.

6 . The aqueous polyurethane dispersion according to claim 1 , wherein the molar ratio of the aliphatic polyisocyanate (A) to the alicyclic polyisocyanate (B), (A): (B), is in a range from 10:90 to 90:10.

7 . The aqueous polyurethane dispersion according to claim 1 , wherein the mass ratio of the polyether polyol (C) to the polycarbonate polyol (D), (C): (D), is in a range from 25:75 to 90:10.

8 . The aqueous polyurethane dispersion according to claim 1 , wherein the resin particles have a cumulative 50% particle size (D 50 ) in a range from 5 to 500 nm in the particle size distribution on a volume basis.

9 . An adhesive comprising:
the aqueous polyurethane dispersion according to claim 1 ; and an isocyanate-based curing agent.

10 . Synthetic leather comprising an adhesion layer formed with the adhesive according to claim 9 .

11 . A paint comprising the aqueous polyurethane dispersion according to claim 1 .

Assignees

• Dainichiseika Color Chem

Inventors

• Muto Kazuaki
• Ino Ryohei

Classifications

• C08G18/755

  and at least one isocyanate or isothiocyanate group linked to a secondary carbon atom of the cycloaliphatic ring, e.g. isophorone diisocyanate · CPC title

• C08G18/4854

  Polyethers containing oxyalkylene groups having four carbon atoms in the alkylene group · CPC title

• C08G18/0823

  containing carboxylate salt groups or groups forming them · CPC title

• D06N3/146

  characterised by the macromolecular diols used · CPC title

• C08G18/6659

  with compounds of group C08G18/34 · CPC title