Fluorescent fluoroplastics

• US 5,888,424 A
• Filed: 07/24/1997
• Issued: 03/30/1999
• Est. Priority Date: 07/24/1997
• Status: Expired due to Fees

• 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: Torardi, Carmine, Ebnesajjad, Sina, Lichtchinski, Vadim Leonidovitch, Wheland, Robert Clayton
• Primary Examiner(s): YOON, TAE H
• Application Number:
  US08/899,936
• Time in Patent Office: 614 Days
• Field of Search: 252/301.5, 252/301.6 R, 252/301.45, 524/413, 524/420, 524/430
• US Class Current: 252/301.5
• CPC Class Codes: C08K 3/01 characterized by their specific function
• CPC Class Codes: C08L 27/12 containing fluorine atoms
• CPC Class Codes: C09K 11/02 Use of particular materials as binders, particle coatings or suspension media therefor
• CPC Class Codes: C09K 11/08 containing inorganic luminescent materials

Abstract

Fluoroplastics become identifiable as to source by incorporating 1 to 450 ppm of inorganic phosphor into the fluoroplastic which does not degrade the fluoroplastic upon processing at a temperature of 300° C. and does not discolor the fluoroplastic but does emit radiation which is characteristic of the phosphor when the fluoroplastic is exposed to excitation radiation.

Claims

1. Fluorescent fluoroplastic, said fluoroplastic being free of color other than provided by said fluoroplastic and being free of discoloration when processed at a temperature of at least 300°

C., said fluoroplastic emitting radiation when subjected to excitation radiation and containing at least one inorganic phosphor which provides said emitted radiation.

2. The fluorescent fluoroplastic of claim 1 wherein said fluoroplastic consists essentially of said fluoroplastic and said inorganic phosphor.

3. The fluorescent fluoroplastic of claim 2 wherein said fluoroplastic is melt-fabricable tetrafluoroethylene or chlorotrifluoroethylene copolymer.

8. The fluorescent fluoroplastic of claim 1 wherein the amount of said inorganic phosphor present in said fluorescent fluoroplastic is 0.5 to 450 ppm based on the weight of said fluoroplastic.

9. The fluorescent fluoroplastic of claim 8 wherein said amount is 1 to 100 ppm.

10. The fluorescent fluoroplastic of claim 1 containing a plurality of said inorganic phosphors which are excited by said incident radiation at either the same or different wavelength.

11. The fluorescent fluoroplastic of claim 10 wherein the total amount of said inorganic phosphors present is 1 to 100 ppm.

12. The fluorescent fluoroplastic of claim 11 wherein said total amount is 1 to 20 ppm.

4. Fluorescent polytetrafluoroethylene, said polytetrafluoroethylene being free of color other than provided by said fluoroplastic and being free of discoloration when processed at a temperature of at least 300°

, said fluoroplastic emitting radiation when subjected to excitation radiation and containing at least one inorganic phosphor which provides said emitted radiation.

5. The fluorescent polytetrafluoroethylene of claim 4 wherein the amount of said inorganic phosphor present in said fluorescent polytetrafluoroethylene is 0.5 to 450 ppm based on the weight of said polytetrafluoroethylene.

6. The fluorescent polytetrafluoroethylene of claim 5 wherein said amount is 1 to 100 ppm.

7. The fluorescent polytetrafluoroethylene of claim 4 wherein said excitation radiation is ultraviolet.