Ultraviolet filters with enhanced weatherability and method of making

• US 6,517,687 B1
• Filed: 03/17/1999
• Issued: 02/11/2003
• Est. Priority Date: 03/17/1999
• Status: Expired due to Term

• Current Assignee: Sabic Innovative Plastics IP BV (Government of Saudi Arabia)
• Original Assignee: General Electric Company
• Inventors: Iacovangelo, Charles Dominic
• Primary Examiner(s): PADGETT, MARIANNE L
• Application Number:
  US09/271,656
• Time in Patent Office: 1,427 Days
• Field of Search: 427/453, 427/455, 427/529, 427/530, 427/531, 427/564, 427/566, 427/567, 427/576, 427/580, 427/525, 427/527, 427/579, 204/192.38, 204/192.16, 204/192.22, 204/192.26, 204/192.29
• US Class Current: 204/192.26
• CPC Class Codes: G02B 5/208 for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation

Abstract

An ultraviolet radiation absorbing layer formed over a polymeric substrate is disclosed herein. The layer is a doped metal oxide coating. The layer exhibits excellent weatherability and UV absorbing properties. The layer is preferably deposited by arc plasma deposition or by sputtering.

Claims

1. A method of preparing a layered structure, said layered structure having improved chemical stability for use in glazing applications, said method comprising the steps of:

providing a transparent polymeric substrate selected from the group consisting of

polycarbonate, polyethercarbonate, polyethersulfone and polyetherimide; and

forming an indium doped zinc oxide layer, said layer having a composition of about In_0.02-0.15Zn_0.85-0.98O, directly on the polymeric substrate to provide a transparent structure wherein the optical density of the doped zinc oxide layer is greater than 2.0.

2. The method of claim 1, further comprising the step of forming an abrasion resistant layer on the doped zinc oxide layer.

3. The method of claim 2, wherein the abrasion resistant layer comprises at least one of silicon dioxide, alumina, or a plasma polymerized organosilicon.

4. The method of claim 1, wherein the doped zinc oxide layer has a thickness of between 1 and 1,000 nm.

5. The method of claim 1, wherein the doped zinc oxide layer has a thickness of between 300 and 600 nm.

6. The method of claim 1, wherein the doped zinc oxide layer has an optical density of at least 4 and exhibits substantially zero increase in haze after being subjected to an accelerated weathering test for at least 300 hours.

7. The method of claim 1, wherein the doped zinc oxide layer is formed in a first chamber of a coating apparatus.

8. The method of claim 7, further comprising the step of forming at least one of an abrasion resistant layer, an adhesion promoting layer, and a stress relief layer in said first chamber of the coating apparatus.

9. The method of claim 1, wherein the layer is formed by DC or RF magnetron sputtering.

10. The method of claim 1, wherein the steps of forming the doped zinc oxide layer comprise:

mounting the substrate on a support in a chamber;

mounting a target in the chamber;

introducing a sputtering gas into the chamber;

creating a sputtering gas plasma in the chamber;

directing the sputtering gas toward the target; and

sputtering a reactant vapor from the target toward the substrate.

11. The method of claim 10, wherein the target comprises an indium doped zinc oxide target;

and the sputtering gas comprises argon.

12. The method of claim 10, wherein the step of creating the sputtering gas plasma comprises applying a DC voltage to the target and applying a magnetic field to the plasma to carry out DC magnetron sputtering.

13. A method of forming an indium doped zinc oxide layer, said layer having a composition of about In_0.02-0.15Zn_0.85-0.98O, on a polymeric substrate to produce a layered structure with improved chemical stability for use in glazing applications, said method comprising the steps of:

placing the substrate in a sputtering chamber;

providing indium and zinc in at least one target; and

performing DC magnetron arc plasma deposition on the target to form an indium doped zinc oxide layer on the substrate.