Laser marking of fluoropolymer composition

• US 5,560,845 A
• Filed: 02/13/1995
• Issued: 10/01/1996
• Est. Priority Date: 02/28/1994
• Status: Expired due to Term

• Current Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Jenkins, Robert S., Spohn, Peter D., Hunt, James F., Walnock, James T., Birmingham, John N. Jr., Holtzen, Dwight A.
• Primary Examiner(s): Walberg, Teresa J.
• Assistant Examiner(s): Mills, Gregory L.
• Application Number:
  US08/387,987
• Time in Patent Office: 596 Days
• Field of Search: 219/121.6, 219/121.68, 219/121.69, 219/121.95, 430/945, 430/947, 427/555, 427/596, 264/22, 264/25, 264/482, 347/262, 347/264, 347/224
• US Class Current: 219/121.85
• CPC Class Codes: B41M 5/267 Marking of plastic artifacts, e.g. with laser
• CPC Class Codes: C01P 2004/02 obtained by optical microscopy
• CPC Class Codes: C01P 2004/62 Submicrometer sized, i.e. from 0.1-1 micrometer
• CPC Class Codes: C08K 9/06 with silicon-containing compounds
• CPC Class Codes: C08L 27/12 containing fluorine atoms
• CPC Class Codes: C09C 1/3684 Treatment with organo-silicon compounds
• CPC Class Codes: Y10S 430/146 Laser beam
• CPC Class Codes: Y10S 430/148 Light sensitive titanium compound containing

Abstract

Laser marking of pigmented fluoropolymer substrates is enhanced by using titanium dioxide pigment coated with organo silane.

Claims

1. In the method of laser marking a substrate comprising melt-fabricable fluoropolymer resin and titanium dioxide pigment, the improvement comprising conducting said laser marking wherein said pigment is coated with a coating comprising organo silane.

2. In the method of claim 1, wherein said substrate is cable jacket or electrical insulation.

3. The method of claim 1, wherein said fluoropolymer is copolymer of tetrafluoroethylene and hexafluoropropylene, copolymer of tetrafluoroethylene and perfluoro(alkyl vinyl ether), copolymer of ethylene and tetrafluoroethylene, copolymer of ethylene and chlorotrifluoroethylene, polyvinylidene fluoride, or vinylidene fluoride copolymer.

4. The method of claim 1 wherein the titanium dioxide of said pigment is crystalline.

5. The method of claim 4, wherein the average particle size of said pigment is 150 to 400 nm.

6. The method of claim 1 wherein the amount of said organo silane is 0.5 to 1.5 wt % based on the total weight:

of silane and said pigment.

7. The method of claim 1 wherein said organo silane is alkyl, cycloalkyl, aryl, or aralkyl silane.

8. The method of claim 1 wherein said substrate is the insulation or jacket for wire or cable.