Plasma coating system for non-planar substrates

• US 7,390,573 B2
• Filed: 03/08/2005
• Issued: 06/24/2008
• Est. Priority Date: 03/09/2004
• Status: Active Grant

• Current Assignee: Exatec, LLC (Government of Saudi Arabia)
• Original Assignee: Exatec, LLC (Government of Saudi Arabia)
• Inventors: Korevaar, Bastian A., Miebach, Thomas, Iacovangelo, Charles D., Mercedes, Michael W.
• Primary Examiner(s): Gulakowski; Randy
• Assistant Examiner(s): Figueroa; John J
• Application Number:
  US11/075,341
• Publication Number:
  US 20050202259A1
• Time in Patent Office: 1,204 Days
• Field of Search: 428/447
• US Class Current: 428/447
• CPC Class Codes: B05D 1/62 Plasma-deposition of organic layers plasma deposition in general C23C14/00, C23C16/00
• CPC Class Codes: C23C 16/513 using plasma jets
• CPC Class Codes: Y10T 428/31663 As siloxane, silicone or silane

Abstract

A non-planar article includes a plasma deposited abrasion resistant coating with a substantially uniform thickness and a substantially uniform abrasion resistance with delta haze (%) in the range between about +/−0.25 of the mean value.

Claims

1. A process for coating a non-planar substrate defining a working distance variation in the range of 6 cm to 16 cm, comprising:

generating a plasma from one or more stationary expanding thermal plasma sources;

injecting a first set of vaporized reagents into the plasma to form a first coating on the substrate; and

injecting a second set of vaporized reagents into the plasma to form one or more coatings over the first coating, the plasma having an Ar flow and arc current that determine the total ion flux that provides substantially uniform properties at various working distances from the expanding thermal plasma source to the substrate, the total ion flux being calculated based on an uncorrected ion flux determined as a function of radial distance across the plasma at a given working distance from the plasma source and fitting the data to a Gaussian distribution, the area under the Gaussian distribution and the width determining the total ion flux.

2. The process of claim 1 wherein the uniform coating property is the coating thickness.

3. The process of claim 1 wherein the uniform coating property is the abrasion resistance of the coating.

4. The process of claim 1 wherein the abrasion resistant coating is a plasma polymerized organosilicon.

5. The process of claim 4 wherein the organosilicon is selected from the group consisting of octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, hexamethyldisiloxane, tetramethyldisiloxane, tetramethyltetravinylcyclotetrasiloxane, vinyltrimethylsilane and dimethyldimethoxysilane.

6. The process of claim 1 wherein the abrasion resistant coating is deposited as two or more layers.

7. The process of claim 6 wherein the first layer has an oxygen content that is lower than the oxygen content of the other layers.

8. The process of claim 7 wherein the layers other than the first layer have the same composition.

9. The process of claim 1 further comprising a plastic substrate and one or more functional layers deposited between the substrate and the abrasion resistant coating.

10. The process of claim 9 wherein the hardness and thickness of the abrasion resistant layer is adjusted based on the hardness of the underlying coatings.

11. The process of claim 9 wherein a functional layer is a silicone hardcoat with organic UV absorbers.

12. The process of claim 11 further comprising a primer layer between the silicone hardcoat and the plastic substrate.

13. The process of claim 9 wherein the functional coating includes inorganic UV filters, IR coatings, AR coatings, TOOs, barrier coatings, and combined multi layers.

14. The process of claim 1 wherein an uncorrected ion flux is measured as a function of radial distance across the plasma at a given working distance from the substrate.

15. The process of claim 14 wherein data associated with the measured uncorrected ion flux is fitted to a Gaussian distribution, the area under the Gaussian distribution and the width providing the ion flux.

16. The process of claim 1 wherein the steps of generating the plasma and injecting the vaporized reagents are done with an Ar flow at 1 .65-2.5 slm, an 0₂ flow at 0.3-1 slm, an octamethylcyclotetrasiloxane flow at up to 0.19 slm, and an arc current of up to 70 amps.