Highly abrasion-resistant, flexible coatings for soft substrates

• US 5,679,413 A
• Filed: 10/11/1996
• Issued: 10/21/1997
• Est. Priority Date: 03/03/1994
• Status: Expired due to Term

• Current Assignee: Morgan Advanced Ceramics Inc.
• Original Assignee: Monsanto Company (Bayer AG)
• Inventors: Daniels, Brian Kenneth, Petrmichl, Rudolph Hugo, Kimock, Fred M., Knapp, Bradley J.
• Primary Examiner(s): TURNER, ARCHENE A
• Application Number:
  US08/730,478
• Time in Patent Office: 375 Days
• Field of Search: 427/534, 427/527, 427/563, 427/562, 427/577, 427/579
• US Class Current: 427/534
• CPC Class Codes: B05D 1/62 Plasma-deposition of organic layers plasma deposition in general C23C14/00, C23C16/00
• CPC Class Codes: B29C 59/16 by wave energy or particle radiation , e.g. infrared heating B29C59/007 takes precedence
• CPC Class Codes: C08J 7/123 Treatment by wave energy or particle radiation C08J7/18 takes precedence
• CPC Class Codes: C23C 16/0245 by etching with a plasma
• CPC Class Codes: C23C 16/30 Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
• CPC Class Codes: C23C 16/513 using plasma jets
• CPC Class Codes: G02B 1/105 Protective coatings
• CPC Class Codes: G02B 1/111 using layers comprising organic materials
• CPC Class Codes: G02B 1/14 Protective coatings, e.g. hard coatings
• CPC Class Codes: Y10S 428/913 Material designed to be responsive to temperature, light, moisture
• CPC Class Codes: Y10T 428/263 Coating layer not in excess of 5 mils thick or equivalent
• CPC Class Codes: Y10T 428/265 1 mil or less
• CPC Class Codes: Y10T 428/31507 Of polycarbonate
• CPC Class Codes: Y10T 428/31663 As siloxane, silicone or silane

Abstract

An abrasion wear resistant coated substrate product is described comprising a substrate and an abrasion wear resistant coating material comprising carbon, hydrogen, silicon, and oxygen. The abrasion wear resistant coating material has the properties of Nanoindentation hardness in the range of about 2 to about 5 GPa and a strain to microcracking greater than about 1% and a transparency greater than 85% in the visible spectrum. The coated products of the present invention are suitable for use in optical applications such as ophthalmic lenses or laser bar code scanner windows. In the method for making the products, the substrate is first chemically cleaned to remove contaminants. In the second step, the substrate is inserted into a vacuum chamber, and the air in said chamber is evacuated. In the third step, the substrate surface is bombarded with energetic ions and/or reactive species to assist in the removal of residual hydrocarbons and surface oxides, and to activate the surface. After the substrate surface has been etched, a protective, abrasion-resistant coating is deposited by plasma or ion beam deposition. Once the chosen thickness of the coating has been achieved, the deposition process on the substrates is terminated, the vacuum chamber pressure is increased to atmospheric pressure, and the coated substrate products having improved abrasion-resistance are removed from the vacuum chamber.

Claims

1. A method for depositing onto a parent substrate an abrasion wear resistant coating material consisting of C, H, Si and O which comprises:

(a) chemically cleaning the surface of said substrate to remove contaminants;

(b) mounting said substrate in a deposition vacuum chamber and evacuating the air from said chamber;

(c) etching the surface of said substrate with a material selected from the group consisting of energetic ions, reactive species and mixtures thereof to further remove residual contaminants, and to activate the surface;

(d) depositing onto the surface of said substrate a layer of said abrasion wear resistant material by exposing said substrate to a deposition flux containing carbon, hydrogen, silicon and oxygen and generated by a plasma, whereby said deposition flux is activated by said plasma and said substrate is bombarded by energetic ions during the deposition;

(e) increasing the vacuum chamber pressure to atmospheric pressure; and

(f) recovering a product coated with said abrasion wear resistant material having the properties of a Nanoindentation hardness in the range of about 2 to about 5 GPa and a strain to microcracking greater than about 1%.

2. The method of claim 1 wherein said substrate comprises a material selected from the group consisting of a metal and a polymer.

3. The method of claim 1 wherein said deposition flux also contain nitrogen and said abrasion wear resistant coating material also contains nitrogen.

4. The method of claim 1 wherein said deposition flux is activated by a radio frequency plasma.

5. The method of claim 1 wherein said deposition flux is activated by a microwave plasma.

6. The method of claim 1 wherein said deposition flux is activated by a direct current plasma.

7. The method of claim 1 wherein the chemical precursors for said deposition flux contains materials selected from the group consisting of siloxanes, silanes, silazanes, and mixtures thereof.

8. The method of claim 1 wherein the chemical precursors for said deposition flux contains materials selected from the group consisting of hexamethyldisiloxane, tetramethylcyclotetrasiloxane, octamethylcyclotetrasiloxane, and mixtures thereof.

9. A method for depositing onto a parent substrate an abrasion wear resistant coating material consisting of C, H, Si and O which comprises:

(a) chemically cleaning the surface of said substrate to remove contaminants;

(b) mounting said substrate in a deposition vacuum chamber and evacuating the air from said chamber;

(c) etching the surface of said substrate with a material selected from the group consisting of energetic ions, reactive species and mixtures thereof to further remove residual contaminants, and to activate the surface;

(d) depositing onto the surface of said substrate an intermediate layer of said abrasion wear resistant material by exposing said substrate to a deposition flux containing carbon, hydrogen, silicon and oxygen having the properties of a Nanoindentation hardness in the range of about 2 to about 5 GPa and a strain to microcracking greater than about 1% and generated by a plasma, whereby said deposition flux is activated by said plasma and said substrate is bombarded by energetic ions during the deposition;

(e) depositing onto said intermediate layer an outer layer of diamond-like carbon;

(f) increasing the vacuum chamber pressure to atmospheric pressure; and

(g) recovering a coated abrasion wear resistant product.

10. The method of claim 9 wherein said deposition flux is activated by a radio frequency plasma.

11. The method of claim 9 wherein said deposition flux is activated by a microwave plasma.

12. The method of claim 9 wherein said deposition flux is activated by a direct current plasma.

13. The method of claim 9 wherein the chemical precursors for said deposition flux contains materials chosen from the group of siloxanes, silanes, silazanes, and mixtures thereof.

14. The method of claim 9 wherein the chemical precursors for said deposition flux contains materials chosen from the group of hexamethyldisiloxane, tetramethylcyclotetrasiloxane, octamethylcyclotetrasiloxane, and mixtures thereof.

15. The method of claim 9 wherein said deposition flux also contains nitrogen and said abrasion wear resistant coating material also contains nitrogen.

16. The method of claim 9 wherein said abrasion wear resistant material has a transparency greater than 85% in the visible spectrum.