Soil-resistant coating for glass surfaces

• US 20030228431A1
• Filed: 06/17/2003
• Published: 12/11/2003
• Est. Priority Date: 12/21/1998
• Status: Active Grant

• Current Assignee: Annette Krisko, Klaus Hartig, Oʼshaughnessy, Roger D.
• Original Assignee: Annette Krisko, Klaus Hartig, Oʼshaughnessy, Roger D.
• Inventors: Krisko, Annette, OʼShaughnessy, Roger D., Hartig, Klaus
• Granted Patent: US 6,939,446 B2
• Time in Patent Office: Days
• US Class Current: 428/34
• CPC Class Codes: C03C 17/245 by deposition from the vapour phase
• CPC Class Codes: C03C 17/3417 all coatings being oxide coatings
• CPC Class Codes: C03C 17/36 at least one coating being a metal
• CPC Class Codes: C03C 17/3618 Coatings of type glass/inorganic compound/other inorganic layers, at least one layer being metallic
• CPC Class Codes: C03C 17/3626 one layer at least containing a nitride, oxynitride, boronitride or carbonitride
• CPC Class Codes: C03C 17/3639 Multilayers containing at least two functional metal layers
• CPC Class Codes: C03C 17/3642 the multilayer coating containing a metal layer
• CPC Class Codes: C03C 17/3644 the metal being silver
• CPC Class Codes: C03C 17/3652 the coating stack containing at least one sacrificial layer to protect the metal from oxidation
• CPC Class Codes: C03C 17/366 Low-emissivity or solar control coatings
• CPC Class Codes: C03C 17/3681 the multilayer coating being used in glazing, e.g. windows or windscreens
• CPC Class Codes: C03C 2217/213 SiO2
• CPC Class Codes: C03C 2217/75 Hydrophilic and oleophilic coatings
• CPC Class Codes: C03C 2217/77 Coatings having a rough surface
• CPC Class Codes: C03C 2218/154 by sputtering
• CPC Class Codes: C03C 2218/155 by reactive sputtering
• CPC Class Codes: C03C 2218/365 Coating different sides of a glass substrate
• CPC Class Codes: C07K 2317/54 F(ab')2
• CPC Class Codes: C23C 14/10 Glass or silica
• CPC Class Codes: C23C 14/3464 using more than one target C23C14/56 takes precedence
• CPC Class Codes: C23C 14/568 : Transferring the substrates through a series of coating stations C23C14/562 takes precedence
• CPC Class Codes: Y10T 428/24421 : Silicon containing
• CPC Class Codes: Y10T 428/31 : Surface property or characteristic of web, sheet or block

Abstract

A glass article which has a water-sheeting coating and a method of applying coatings to opposed sides of a substrate are described. In one embodiment, a water-sheeting coating 20 comprising silica is sputtered directly onto an exterior surface of the glass. The exterior face of this water-sheeting coating is substantially non-porous but has an irregular surface. This water-sheeting coating causes water applied to the coated surface to sheet, making the glass article easier to clean and helping the glass stay clean longer. In one method of the invention, interior and exterior surfaces of a glass sheet are cleaned. Thereafter, the interior surface of the sheet of glass is coated with a reflective coating by sputtering, in sequence, at least one dielectric layer, at least one metal layer, and at least one dielectric layer. The exterior surface of the glass is coated with a water-sheeting coating by sputtering silica directly onto the exterior surface of the sheet of glass. If so desired, both the interior surface and the exterior surface can be applied during the same pass through the same sputter coating apparatus while the glass maintains a constant orientation wherein the interior surface is positioned above the exterior surface.

Claims

1. A glass article having an interior surface bearing a first water-sheeting coating and an exterior surface bearing a second water-sheeting coating, the first and second water-sheeting coatings each comprising silica sputtered directly onto the respective surface of the glass article and having an exterior face that is substantially non-porous but has an irregular surface, the first and second water-sheeting coatings each reducing the contact angle of water on the respective surfaces below 25°

and causing water applied thereto to sheet.

2. A multi-pane insulated glass unit comprising:

a) first and second panes of glass held in a spaced-apart relationship by a spacer to define a sealed interpane space, the first pane having an exterior surface oriented away from the second pane and exposed to periodic contact with water, the second pane having an interior surface exposed to the interpane space and an exterior surface oriented away from the first pane;

b) a first water-sheeting coating carried on the exterior surface of the first pane; and

c) a second water-sheeting coating carried on the exterior surface of the second pane;

the first and second water-sheeting coatings each comprising silica sputtered directly onto the respective surface of the first and second panes and having an exterior face that is substantially non-porous but has an irregular surface, the first and second water-sheeting coatings each reducing the contact angle of water on the respective surface of the first and second panes to below 25° and

causing water applied thereto to sheet.

3. A method of rendering surfaces of a pane of glass resistant to soiling and staining, comprising:

a) providing a sheet of glass having a clean interior surface and a clean exterior surface;

b) sputtering silica directly onto the interior surface of the sheet of glass, thereby yielding a first water-sheeting coating having a contact angle with water below about 25°

which causes water applied to said interior surface to sheet; and

c) sputtering silica directly onto the exterior surface of the sheet of glass, thereby yielding a second water-sheeting coating having a contact angle with water below about 25°

which causes water applied to said exterior surface to sheet.

4. The method of claim 3 further comprising exposing one of the interior and exterior surfaces of the sheet of glass to periodic contact with water, the water-sheeting coating on the exposed surface reducing soiling and staining that would otherwise result from the periodic contact with water.

5. The method of claim 3 wherein the first and second water-sheeting coatings are sputtered from a silicon target in an oxygen-containing sputtering chamber.

6. A method of coating two sides of a pane of glass in a single pass through a coating apparatus, comprising:

a) providing a sheet of glass having a clean first surface and a clean second surface;

b) providing a sputtering chamber having a plurality of rollers that define a substrate support therein, the chamber having an upper target positioned above the support and being adapted to downwardly sputter, the chamber having a lower target positioned below the support and being adapted to upwardly sputter;

c) positioning the sheet of glass in the chamber such that the first surface of the sheet of glass rests on one or more of the rollers and is oriented toward the lower target, whereby the second surface of the sheet of glass is oriented toward the upper target;

d) sputtering the lower target to deposit a first water-sheeting coating on the first surface of the glass, the first water-sheeting coating having a contact angle with water below about 25°

which causes water applied to said first surface to sheet; and

e) sputtering the upper target to deposit a second water-sheeting coating on the second surface of the glass, the second water-sheeting coating having a contact angle with water below about 25°

which causes water applied to said second surface to sheet.

7. The method of claim 6 wherein the upper and lower targets are sputtered substantially simultaneously.

8. The method of claim 6 wherein the upper and lower targets comprise silicon and are sputtered in an oxidizing atmosphere.

9. A method of rendering a glass surface resistant to soiling and staining, comprising:

a) providing a sheet of glass having a clean interior surface and a clean exterior surface;

b) providing a sputtering line comprising a series of sputtering chambers, each sputtering chamber having a plurality of rollers that define a substrate support, the sputtering line having an upward sputtering chamber with a lower target positioned below the rollers in that chamber;

c) positioning the sheet of glass in the upward sputtering chamber such that the exterior surface of the sheet of glass rests on two or more of the rollers in that chamber; and

d) sputtering the lower target to deposit silica directly onto the exterior surface of the glass, thereby yielding a water-sheeting coating having a contact angle with water below about 25°

which causes water applied to the exterior surface to sheet, the sputtered silica travelling between said two or more rollers before being deposited on the exterior surface of the sheet of glass.

10. The method of claim 9 wherein the lower target comprises silicon and is sputtered in an oxidizing atmosphere.