Method for the production of unsupported thin film particles

• US 6,376,018 B1
• Filed: 06/17/1998
• Issued: 04/23/2002
• Est. Priority Date: 06/17/1998
• Status: Expired due to Fees

• Current Assignee: The Wilfred C. Kittler Trust
• Original Assignee: Wilfred C. Kittler Jr
• Inventors: Kittler, Wilfred C. Jr.
• Primary Examiner(s): PIANALTO, BERNARD D
• Application Number:
  US09/098,845
• Time in Patent Office: 1,406 Days
• Field of Search: 427/356, 427/357, 427/404, 427/407.1, 427/416, 427/294, 204/192.1
• US Class Current: 427/294
• CPC Class Codes: C01P 2004/20 extending in two dimensions, e.g. plate-like
• CPC Class Codes: C09C 1/0015 Pigments exhibiting interference colours, e.g. transparent platelets of appropriate thinness or flaky substrates, e.g. mica, bearing appropriate thin transparent coatings
• CPC Class Codes: C09C 1/0018 uncoated and unlayered plate-like particles
• CPC Class Codes: C09C 2220/20 PVD, CVD methods or coating in a gas-phase using a fluidized bed
• CPC Class Codes: C23C 14/0005 Separation of the coating from the substrate
• CPC Class Codes: C23C 14/568 Transferring the substrates through a series of coating stations C23C14/562 takes precedence

Abstract

A method and an apparatus for producing unsupported thin film particles are provided. The apparatus includes: (a) a vacuum chamber; (b) a rotatable drum disposed within the vacuum chamber; (c) means within the vacuum chamber for depositing a surface coating onto the drum when the drum is rotating; (d) means for depositing at least one thin film layer onto the surface coating to provide a thin film structure disposed atop the surface coating; and (e) a knife blade disposed proximate to the surface of the drum, such that a thin film structure deposited onto the drum can be scraped away from the drum by the rotation of the drum. In the method, a surface coating, such as a wax, is applied directly to the moving surface. Thereafter, one or more thin film layers is deposited upon the surface coating. The thin film layer or layers are thereafter scraped away from the surface coating using the knife blade. Residual surface coating material is removed from the thin film flakes and is then recycled for redeposition onto the drum.

Claims

1. A method for the production of unsupported thin film composite particles comprising the steps of:

(a) within a vacuum chamber, depositing a surface coating onto a rotating drum, the rotating drum being temperature controllable to temperatures below a preselected maximum temperature;

(b) depositing a first thin film layer onto the surface coating;

(c) depositing a second thin film layer onto the first thin film layer to form a thin film composite;

(d) scraping the thin film composite from the surface coating;

(e) within a vacuum chamber, depositing additional surface coating onto the rotatable drum; and

(f) continuously repeating steps (b)-(e).

2. The method of claim 1 wherein the vacuum chamber comprises a plurality of discrete subchambers wherein within subchamber a different material is deposited onto the rotating drum.

3. The method of claim 1 wherein the surface coating is a wax.