Method for producing transparent protective coatings from silicon compounds

• US 4,762,730 A
• Filed: 09/03/1986
• Issued: 08/09/1988
• Est. Priority Date: 07/19/1986
• Status: Expired due to Fees

• Current Assignee: Leybold Aktiengesellschaft
• Original Assignee: Leybold-Heraeus GmbH (Leybold Aktiengesellschaft)
• Inventors: Zultzke, Walter, Enke, Knut
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US06/903,511
• Time in Patent Office: 706 Days
• Field of Search: 427/40, 427/41, 427/164, 427/255.3, 427/255.6, 427/322, 427/162
• US Class Current: 427/489
• CPC Class Codes: B05D 1/62 Plasma-deposition of organic layers plasma deposition in general C23C14/00, C23C16/00
• CPC Class Codes: B29D 11/00865 Applying coatings; tinting; colouring printing, marking or copying processes B41M; identification in general G09F3/00; producing decorative effects in general B44C; positioning or marking of lenses B24B13/0055
• CPC Class Codes: C08G 77/00 Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
• CPC Class Codes: C08J 7/123 Treatment by wave energy or particle radiation C08J7/18 takes precedence
• CPC Class Codes: C09D 4/00 Coating compositions, e.g. paints, varnishes or lacquers, based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond ; Coating compositions, based on monomers of macromolecular compounds of groups C09D183/00 - C09D183/16
• CPC Class Codes: G02B 1/105 Protective coatings
• CPC Class Codes: G02B 1/14 Protective coatings, e.g. hard coatings

Abstract

A method for producing a transparent protective coating on a plastic optical substrate surface is disclosed. In particular, a substrate is positioned between two electrodes on the cathode in a reaction chamber. Once positioned, a noble gas is introduced into the chamber and the surface of the plastic optical substrate is bombarded. A monomeric organic compound of either siloxane or silazane is introduced into the reaction chamber and a bias voltage of a value in the range of 80 to 500 volts is obtained to polymerize the compound on the substrate surface. Following the beginning of this polymerization, oxygen is introduced into the reaction chamber in an amount of about 5 times the amount of the monomeric organic compound to form a mixture with the compound.

Claims

1. A method for producing a transparent protective coating on a surface of a plastic optical substrate in a reaction chamber having at least two electrodes of opposed polarity, one of the electrodes functioning as a cathode, the method comprising the following steps:

(a) positioning the substrate on the cathode in the reaction chamber;

(b) introducing a noble gas into the reaction chamber;

(c) exposing the surface of the plastic optical substrate to ion bombardment in the noble gas plasma, the ion bombardment being produced between the electrodes by a bias voltage formed at the cathode by a radiofrequency means;

(d) introducing a monomeric organic compound into the reaction chamber comprising a member of the group of siloxane and silazane, the organic compound being polymerized by the plasma to coat the surface of the plastic optical substrates;

(e) setting the bias voltage at the cathode at a value in the range of -80 to -500 volts; and

(f) introducing oxygen into the reaction chamber during polymerization of the monomeric organic compound, the oxygen having a partial pressure of at least five times the partial pressure of the monomeric organic compound to form a mixture with the compound.

2. The method according to claim 1 wherein the siloxane is hexamethyldisiloxane of the formula:

space="preserve" listing-type="equation">(CH.sub.3).sub.3 --Si--O--Si--(CH.sub.3).sub.3.

3. The method according to claim 1, wherein the setting step (e) further comprises:

setting the bias voltage of the cathode to a value in the range of -80 to -250 volts to produce the ion bombardment.

4. The method according to claim 1, wherein the monomeric organic compound is polymerized at a pressure having a range of 10^-3 to 10 mbar.

5. The method according to claim 1, wherein the introducing of oxygen of step (f) further comprises:

introducing oxygen into the reaction chamber having a partial pressure of at least five times higher than a partial pressure of the monomeric organic compound introduced into the reaction chamber.