# US 12,760,201 B2 · Scalable inter-diffused zwitterionic polyurethanes for durable antibacterial coatings

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- Number: US 12,760,201 B2
- Document ID: US12760201B2
- Status: Granted
- Kind: B2
- Application number: 18/465,342
- Filed: 2023-09-12
- Published: 2024-01-18
- Granted: 2026-10-13
- Earliest claimed: 2021-01-07
- Assignees: University of Houston System
- Applicants: University of Houston System
- Inventors: Hadi Ghasemi; Zixu Huang
- Web page: https://patentgrep.com/patent/US12760201B2

## CPC

- C09D 175/12: from compounds containing nitrogen and active hydrogen, the nitrogen atom not being part of an isocyanate group
- B05D 1/38: with intermediate treatment (intermediate treatment per se B05D3/00)
- B05D 7/546: {each layer being cured, at least partially, separately}
- C08G 18/10: Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
- C08G 18/3275: {containing two hydroxy groups}
- C08G 18/4263: {containing carboxylic acid groups}
- C08G 18/73: acyclic
- C08G 18/755: {and at least one isocyanate or isothiocyanate group linked to a secondary carbon atom of the cycloaliphatic ring, e.g. isophorone diisocyanate}
- C09D 5/14: Paints containing biocides, e.g. fungicides, insecticides or pesticides (C09D5/16 takes precedence)
- B05D 1/02: performed by spraying
- B05D 5/00: Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures
- B05D 2490/50: compositions varying with a gradient perpendicular to the surface
- B05D 2503/00: Polyurethanes
- C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D)
- B05D: PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL (conveying articles or workpieces through baths of liquid B65G, e.g. B65G49/02)
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS

## Abstract

Durable antibacterial coatings are prepared by inter-diffusing zwitterionic polyurethane in acrylic polyurethane. Bacterial attachment is substantially eliminated from the surface of the coatings due to the hydrophilicity of the zwitterionic polyurethane. Long-term antibacterial properties were observed for both Gram-negative and Gram-positive bacteria even when the coatings were constantly challenged by mechanical abrasion.

## Claims

### Claim 1

An antibacterial polyurethane coating prepared by a method comprising:
depositing an acrylic polyurethane base layer on a surface, wherein the acrylic polyurethane base layer is hydrophobic and comprises a ratio of hydroxyl groups to isocyanate groups of about 1.0/1.5;
allowing the acrylic polyurethane base layer to partially cure, to produce a semi-cured acrylic polyurethane base layer;
spraying a zwitterionic polyurethane on the semi-cured acrylic polyurethane base layer, wherein the zwitterionic polyurethane is hydrophilic and comprises a ratio of hydroxyl groups to isocyanate groups of about 1.1/1.0;
allowing the zwitterionic polyurethane to inter-diffuse into the acrylic polyurethane base layer to form an inter-diffused polyurethane coating; and
allowing the inter-diffused polyurethane coating to cure to form an antibacterial polyurethane coating, wherein the antibacterial polyurethane coating has a coating surface that is hydrophilic and lacks isocyanate groups.

### Claim 2 (depends on 1)

The antibacterial polyurethane coating of claim 1, wherein the zwitterionic polyurethane has a structure of:
wherein n is between 2 and 70.

### Claim 3 (depends on 1)

The antibacterial polyurethane coating of claim 1, wherein the antibacterial polyurethane coating comprises molecules having a structure of:

### Claim 4 (depends on 1)

The antibacterial polyurethane coating of claim 1, wherein the antibacterial polyurethane coating inhibits bacterial attachment and biofilm formation on the coating surface.

### Claim 5

An antibacterial polyurethane coating comprising molecules having a structure of:

### Claim 6 (depends on 5)

The antibacterial polyurethane coating of claim 5, wherein the antibacterial polyurethane coating inhibits bacterial attachment and biofilm formation on the coating surface.