Cellulose nanomaterial (CN) based waterborne polyurethane coating

Patent metadata

Field	Value
Publication number	US-11827795-B2
Application number	US-202016989257-A
Country	US
Kind code	B2
Filing date	Aug 10, 2020
Priority date	Aug 13, 2019
Publication date	Nov 28, 2023
Grant date	Nov 28, 2023

Abstract

The present disclosure relates to a novel cellulose nanomaterial (CN) based waterborne polyurethane coating, and to methods of making and using the novel cellulose nanomaterial (CN) based waterborne polyurethane coating.

First claim

We claim:

1. A cellulose nanomaterial (CN) based waterborne polyurethane coating, wherein the polyurethane coating is a reaction product of a mixture consisting of CN, water, and at least one water-dispersible blocked polyisocyanate, wherein said CN is an active polyol, contributes at least 40-90 wt % of the total weight of the polyurethane coating, and comprises cellulose nanocrystals (CNC) or cellulose nanofibrils (CNF).

2. The CN based waterborne polyurethane coating of claim 1 , wherein the polyurethane coating is formed under an elevated temperature of 70-200° C.

3. The CN based waterborne polyurethane coating of claim 1 , wherein the polyurethane coating is formed through crosslinking reaction between hydroxyl groups of said CN and blocked isocyanate groups of the at least one water-dispersible blocked polyisocyanate, wherein said CN and the at least one water-dispersible blocked polyisocyanate are crosslinked through carbamate functional groups.

4. The CN based waterborne polyurethane coating of claim 1 , wherein the at least one water-dispersible blocked polyisocyanate is selected from the group consisting of diphenylmethane 4, 4′-diisocyanate (MDI) based water-dispersible blocked polyisocyanate, hexamethylene diisocyanate (HDI) based water-dispersible blocked polyisocyanate, bis(4-isocyanatocyclohexyl) methane based water-dispersible blocked polyisocyanate, isophorone diisocyanate (IPDI) based water-dispersible blocked polyisocyanate, toluene diisocyanate (TDI) based water-dispersible blocked polyisocyanate, and any combination thereof.

5. A method of preparing the cellulose nanomaterial (CN) based waterborne polyurethane coating of claim 1 , wherein the method consists of:
providing a CN aqueous suspension;
providing an aqueous suspension of at least one water-dispersible blocked polyisocyanate;
mixing the CN aqueous suspension and the aqueous suspension of at least one water-dispersible blocked polyisocyanate to provide a substantially homogenous mixture;
applying a layer of the substantially homogenous mixture to a substrate; and
curing the layer of the substantially homogenous mixture at an elevated temperature to provide the CN based waterborne polyurethane coating.

6. The method of claim 5 , wherein the substrate is a metal, glass, polymer, or ceramic material.

Assignees

• Purdue Research Foundation

Inventors

• Youngblood Jeffrey Paul
• Chowdhury Reaz Ahmed
• El Awad Azrak Sami Miguel

Classifications

• C09D101/02 Primary

  Cellulose; Modified cellulose · CPC title

• C08G18/6484

  Polysaccharides and derivatives thereof · CPC title

• C08G18/73

  acyclic · CPC title

• C08G18/7621

  being toluene diisocyanate including isomer mixtures · CPC title

• C08G18/7692

  containing at least one isocyanate or isothiocyanate group linked to an aromatic ring by means of an aliphatic group · CPC title