Antimicrobial coating
The present invention relates to a process for producing an antimicrobial coating on a glass substrate, an antimicrobial coated glass substrate prepared by the process and use thereof, the process comprising the steps of: i) providing a glass substrate having a first surface and a second surface; ii) providing a silicon containing solution and a particle containing solution; iii) mixing together the silicon containing solution and the particle containing solution to form a silica coating composition; iv) contacting at least said first surface of the substrate with the silica coating composition to deposit a layer of silica on the glass substrate; and iv) curing the silica coating composition deposited on the glass substrate to form a silica matrix coating layer, wherein the particles are deposited on and/or within the silica matrix coating layer wherein the particles are deposited on and/or within the silica matrix coating layer in an amount of from 0.1 to 20% by weight.
1 . A process for producing an antimicrobial coating on a glass substrate, the process comprising the steps of:
i) providing a glass substrate having a first surface and a second surface;
ii) providing a silicon containing solution and a particle containing solution which comprises particles;
iii) mixing together the silicon containing solution and the particle containing solution to form a silica coating composition;
iv) contacting at least said first surface of the substrate with the silica coating composition to deposit a layer of the silica coating composition on the glass substrate; and
v) curing the silica coating composition deposited on the glass substrate to form a silica matrix coating layer, wherein the particles are deposited on and/or within the silica matrix coating layer in an amount of from 0.1 to 20% by weight, resulting in an antimicrobial coated glass substrate;
wherein the silica coating composition further comprises at least 1.0% by weight aluminium relative to the amount of silica in the silica matrix coating layer;
wherein the particle containing solution comprises metal particles and/or metal agglomerates, and the metal particles and/or metal agglomerates comprise copper; and
wherein the antimicrobial coated glass substrate provides at least a 2 log reduction against gram positive and/or gram negative bacteria within 2 hours at 37° C.
2 . The process according to claim 1 , wherein the metal particles comprise a size range of from 10 nm to 150 nm, and wherein the metal agglomerates comprise a size range of from 1 μm to 4 μm.
3 . The process according to claim 1 , wherein the silicon containing solution and the particle containing solution each comprise a solvent.
4 . The process according to claim 3 , wherein the solvent is selected from the group consisting of: ethanol, methanol, isopropyl alcohol, diacetone alcohol, 1-methoxy 2-propoanol (PGME), propylene glycol, methyl isobutyl ketone (MIBK) and mixtures thereof.
5 . The process according to claim 1 , wherein the silica coating composition comprises at least 65% by weight silica.
6 . The process according to claim 1 , wherein the silica matrix coating layer is based on: a polysilazane of formula:
[R 1 R 2 Si—NR 3 ] n ,
wherein R 1 , R 2 , and R 3 are each independently selected from H or C 1 to C 4 alkyl, and n is an integer; or
tetraethyl orthosilicate, (TEOS).
7 . The process according to claim 1 , wherein the silica coating composition is applied directly in contact with the glass substrate.
8 . The process according to claim 1 , wherein the aluminium is present in or on the silica matrix coating layer in the form of an oxide of aluminium.
9 . The process according to claim 1 , wherein the silica coating composition is applied to the glass substrate by means of one or more of: dip coating; spin coating; curtain coating; roller coating; spray coating; air atomisation spraying; ultrasonic spraying; or slot-die coating.
10 . The process according to claim 9 , wherein the silica coating composition is applied to the glass substrate by roller coating or spray coating.
11 . The process according to claim 1 , further comprising the step of cleaning the surface of the glass substrate before applying the silica coating composition.
12 . The process according to claim 11 , wherein cleaning comprises the step of treating the surface of the glass substrate by one or more of: abrasion with ceria; washing with alkaline aqueous solution; rinsing with deionised water; and/or plasma treatment.
13 . The process according to claim 1 , wherein curing the silica coating composition comprises irradiating the glass substrate with applied silica coating composition with ultraviolet radiation and/or heating to a temperature in the range 90° C. to 450° C.
14 . The process according to claim 1 , wherein curing the silica coating composition comprises heating the glass substrate and silica coating composition to a temperature in the range 90° C. to 250° C.
15 . The process according to claim 1 , wherein the silica matrix coating layer is deposited to a thickness in the range 5 nm to 200 nm.
16 . The process according to claim 1 , wherein a transparent conductive oxide coating is applied to the glass substrate before deposition of the silica coating composition.
17 . The process according to claim 1 , wherein the glass substrate is an architectural or automotive glazing.