Multilayer Coatings By Plasma Enhanced Chemical Vapor Deposition

• US 20080095954A1
• Filed: 09/02/2005
• Published: 04/24/2008
• Est. Priority Date: 09/27/2004
• Status: Abandoned Application

• Current Assignee: Dow Global Technologies, Inc. (Dow, Inc.)
• Original Assignee: Dow Global Technologies, Inc. (Dow, Inc.)
• Inventors: Lambert, Christina, Gabelnick, Aaron
• Application Number:
  US11/661,055
• Publication Number:
  US 20080095954A1
• Time in Patent Office: Days
• US Class Current: 427/579
• CPC Class Codes: B05D 1/62 Plasma-deposition of organic layers plasma deposition in general C23C14/00, C23C16/00
• CPC Class Codes: B05D 2201/00 Polymeric substrate or laminate
• CPC Class Codes: B05D 7/53 Base coat plus clear coat type
• CPC Class Codes: C08J 7/123 Treatment by wave energy or particle radiation C08J7/18 takes precedence
• CPC Class Codes: C23C 16/0272 Deposition of sub-layers, e.g. to promote the adhesion of the main coating
• CPC Class Codes: C23C 16/401 containing silicon

Abstract

The present invention provides a process for preparing a multiple layer coating on the surface of an organic polymeric substrate by means of atmospheric pressure plasma deposition, the steps of the process comprising depositing a layer (first layer) of a plasma polymerized, optically clear, highly adherent, organosilicon compound onto the surface of the organic polymeric substrate by atmospheric pressure plasma deposition of a gaseous mixture comprising an organosilicon reagent compound and optionally an oxidant in a first step and thereafter in a second step depositing a substantially uniform layer (second layer) of a silicon oxide compound onto the exposed surface of said first layer by atmospheric pressure plasma deposition of a gaseous mixture comprising an oxidant and an organosilicon reagent compound, wherein the molar ratio of oxidant to organosilicon reagent compound in the gaseous mixture is greater in the second step than in the first step.

Claims

1. A process for preparing a multiple layer coating on the surface of an organic polymeric substrate by means of atmospheric pressure plasma deposition, the steps of the process comprising depositing a layer (first layer) of a plasma polymerized, optically clear, highly adherent, organosilicon compound onto the surface of the organic polymeric substrate by atmospheric pressure plasma deposition of a gaseous mixture comprising a tetraalkylorthosilicate compound and optionally an oxidant in a first step and thereafter in a second step depositing a substantially uniform layer (second layer) of a silicon oxide compound onto the exposed surface of said first layer by atmospheric pressure plasma deposition of a gaseous mixture comprising an oxidant and a tetraalkylorthosilicate compound, wherein the molar ratio of oxidant to tetraalkylorthosilicate compound in the gaseous mixture used is greater in the second step than in the first step.

2. The process of claim 1 wherein the organosilicon compound used in the first and second steps is a tetraalkylorthosilicate.

3. The process of claim 2 wherein the tetraalkylorthosilicate is tetraethylorthosilicate.

4. The process of claim 1 wherein the surface of the substrate is not pretreated by metallization or by chemical or physical oxidation processes in the absence of a silicon compound.

5. The process of any one of claims 1-4 wherein the organic polymer substrate is a polycarbonate.

6. The process of claim 5 wherein the oxidant is O₂.

7. A process for preparing a multiple layer coating on the surface of an organic polymeric substrate by means of atmospheric pressure plasma deposition, the steps of the process comprising depositing a layer (first layer) of a plasma polymerized, optically clear, organosilicon compound of the formula SiN_wC_xO_yH_z onto the surface of the organic polymeric substrate by atmospheric pressure plasma deposition of a gaseous mixture comprising a tetraalkylorthosilicate compound and optionally an oxidant in a first step and thereafter in a second step depositing a substantially uniform layer (second layer) of a silicon oxide compound onto the exposed surface of said first layer by atmospheric pressure plasma deposition of a gaseous mixture comprising an oxidant and a tetraalkylorthosilicate compound, wherein the molar ratio of oxidant to tetraalkylorthosilicate compound in the gaseous mixture used in the second step is greater than in the first step.

8. The process of claim 7 wherein the silicon oxide compound corresponds to the formula:

SiN_w′

C_x′

O_y′

H_z′

, wherein;

w is a number from 0 to 1.0

x is a number from 0.1 to 3.0,

y is a number from 0.5 to 5.0,

z is a number from 0.1 to 5.0,

w′

is a number from 0 to 1.0,

x′

is a number from 0 to 0.5

y′

is a number from 1.0 to 5.0, and

z′

is a number from 0.1 to 10.0.

9. The process of claim 7 wherein the tetraalkylorthosilicate compound used in the first and second steps is the same.

10. The process of claim 9 wherein the tetraalkylorthosilicate compound is tetraethylorthosilicate.

11. The process of claim 7 wherein the surface of the substrate is not pretreated by metallization or by chemical or physical oxidation processes.

12. The process of any one of claims 7 to 11 wherein the organic polymer substrate is a polycarbonate.

13. The process of any one of claims 7 to 11 wherein the organic polymer substrate is a poly(meth)acrylate.

14. The process of claim 12 or 13 wherein the oxidant is O₂.