Optical coating method, apparatus and product

Patent metadata

Field	Value
Publication number	US-2019010083-A1
Application number	US-201816128048-A
Country	US
Kind code	A1
Filing date	Sep 11, 2018
Priority date	Nov 30, 2011
Publication date	Jan 10, 2019
Grant date	—

Abstract

This disclosure is directed to an improved process for making glass articles having optical coating and easy-to clean coating thereon, an apparatus for the process and a product made using the process. In particular, the disclosure is directed to a process in which the application of the optical coating and the easy-to-clean coating can be sequentially applied using a single apparatus. Using the combination of the coating apparatus and the substrate carrier described herein results in a glass article having both optical and easy-to-clean coating that have improved scratch resistance durability and optical performance, and in addition the resulting articles are “shadow free.”

First claim

We claim:

1 . A method for coating a glass article with an optical coating and an easy-to-clean (ETC) coating, the method comprising:
loading a glass substrate on a magnetic substrate carrier having a substrate retention area, a substrate retention surface, and a base having an underside, and attaching the magnetic substrate carrier having the glass substrate thereon to a magnetic rotatable dome within a vacuum chamber so that one side of the glass substrate can be coated with the optical coating and ETC coating, wherein the substrate carrier does not include elements that project beyond the one side of the glass substrate; evacuating the vacuum chamber; rotating the magnetic rotatable dome and depositing the optical coating on the glass substrate; rotating the magnetic rotatable dome and depositing the ETC coating on top of the optical coating following deposition of the optical coating, wherein the optical coating is not exposed to ambient atmosphere prior to the deposition of the ETC coating; and removing the glass substrate having the optical coating and the ETC coating from the vacuum chamber to obtain a glass substrate having a uniform, shadow-free optical coating deposited on the glass substrate and the ETC coating deposited on the optical coating.

2 . The method according to claim 1 , wherein an adhesive material is positioned over the substrate retention surface in the substrate retention area to releasably affix the glass substrate to the substrate retention surface.

3 . The method according to claim 2 , wherein the magnetic substrate carrier further comprises a polymer film positioned between the retention surface and the adhesive material.

4 . The method according to claim 3 , wherein the polymer film comprises a thermoplastic polymer film.

5 . The method according to claim 3 , wherein the polymer film is a static film.

6 . The method according to claim 2 , wherein the adhesive material is a pressure sensitive adhesive.

7 . The method according to claim 2 , wherein the adhesive material is selected from the group consisting of acrylic adhesives, rubber adhesives, and silicone adhesives.

8 . The method according to claim 2 , wherein attaching the magnetic substrate carrier having the glass substrate thereon to the magnetic rotatable dome comprises using a plurality of magnets coupled to the underside of the substrate carrier base and positioned outside of a perimeter of the substrate retention area.

9 . The method according to claim 1 , further comprising:
positioning the glass substrate on the substrate retention surface and supporting the glass substrate with a plurality of pins, a spring system comprising a retractable pin held in place by a spring which biases the retractable pin into contact with the glass substrate when the substrate is positioned on the retention surface, and a plurality of side stoppers extending from the substrate carrier base for a distance such that, tops of the plurality of side stoppers are below the one side of the glass substrate.

10 . The method according to claim 1 further comprising:
supporting the glass substrate on the substrate retention surface with a plurality of pins, a housing with a retractable pin disposed in the housing, wherein the retractable pin is held in place by a spring, the retractable pin being outwardly biased from the housing and into contact with the glass substrate when the substrate is positioned on the retention surface, and a plurality of movable pins for holding an edge of the glass substrate when the substrate is positioned on the retention surface, wherein positions of the plurality of pins are adjustable to accommodate substrates of different shapes and dimensions.

11 . The method according to claim 1 , further comprising curing the ETC coating in air at room temperature or by heating the ETC coating.

12 . The method according to claim 1 , wherein the vacuum chamber is evacuated to a pressure of less than or equal to 10 −4 Torr.

13 . The method according to claim 1 further comprising densifying the optical coating as the optical coating is deposited.

14 . The method according to claim 1 , wherein the vacuum chamber contains at least one e-beam source for vaporizing source materials for the optical coating.

15 . The method according to claim 1 , wherein depositing the optical coating comprises depositing a multilayer optical coating comprising at least one period of a high refractive index material and a low refractive index material, wherein:
the high refractive index material is selected from the group consisting of ZrO 2 , HfO 2 , Ta 2 O 5 , Nb 2 O 5 , TiO 2 , Y 2 O 3 , Si 3 N 4 , SrTiO 3 , WO 3 ; and the low refractive index material is selected from the group consisting of SiO 2 , MgF 2 , YF 3 , YbF 3 and Al 2 O 3 .

16 . The method according to claim 1 , wherein the glass substrate is formed from ion-exchanged silica glass, non-ion-exchanged silica glass, aluminosilicate glass, borosilicate glass, aluminoborosilicate glass, or soda lime glass.

17 . The method according to claim 1 , wherein source material for the ETC coating is a alkyl perfluorocarbon silane of formula (RF) x SiX 4-x , where R F is a linear C 6 -C 30 alkyl perfluorocarbon, X=Cl or —OCH 3 — and x=2 or 3.

18 . The method according to claim 1 , wherein a variation in a thickness of the optical coating from a first edge of the optical coating to second edge of the optical coating of the glass substrate is less than or equal to 2%.

19 . A glass article made by the method according to claim 1 , the glass article comprising the optical coating and the easy-to-clean coating on top of the optical coating, the glass article being shadow free across an optically coated surface of the glass article, wherein:
the optical coating comprises a plurality of periods consisting of a layer of high refractive index material H having an index of refraction n greater than or equal to 1.7 and less than or equal to 3.0, and a layer of low refractive index material L having an index of refraction n greater than or equal to 1.3 and less than or equal to 1.6, the layer of high refractive index material H being a first layer of each period and the layer of low refractive index material L being a second layer of each period; and an SiO 2 capping layer having a thickness in a range greater than or equal to 20 nm and less than or equal to 200 nm applied on top of the plurality of periods.

20 . The glass article according to claim 19 , wherein the glass article has a water contact angle of at least 75° after 6,000 abrasion cycles.

21 . The glass article according to claim 19 , wherein after 8,000 abrasion cycles, scratches on a surface of the glass article are less than 2 mm in length.

22 . The glass article according to claim 19 , wherein a % Reflectance of the glass article after at least 8,000 abrasion/wiping cycles is substantially the same as the % Reflectance of an unabraded/unwiped glass article.

23 . The glass article according to claim 19 , wherein a % Transmission of the glass article after at least 8,000 abrasion/wiping cycles is substantially the same as the % Transmission of an unabraded/unwiped glass article.

24 . The glass article according to claim 15 , wherein a variation in a thickness of the optical coating from a first edge of the optical coating to second edge of the optical coating of the glass article is less than or equal to 2%.

Assignees

• Corning Inc

Inventors

• Lee Christopher Morton
• Lu Xiao-Feng
• Ouyang Michael Xy
• Zhang Junhong

Classifications

• C03C17/00 Primary

  Surface treatment of glass, not in the form of fibres or filaments, by coating (optical coatings of optical elements G02B1/10) · CPC title

• C03C17/002 Primary

  for flat glass, e.g. float glass · CPC title

• B05D1/60

  Deposition of organic layers from vapour phase (vapour phase deposition in general C23C14/00, C23C16/00) · CPC title

• B05D2203/35

  Glass · CPC title

• B05D5/083

  involving the use of fluoropolymers · CPC title