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Removal of Surface Layer From Treated TEFLON

IP.com Disclosure Number: IPCOM000036062D
Original Publication Date: 1989-Aug-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Christie, F: AUTHOR [+2]

Abstract

Alkaline oxidizing solutions have been found to be very effective in removing the dark brown-to-black surface layers produced by treatment of TEFLON* with strong reducing agents such as non-aqueous solutions of sodium napthalenide. In particular, a solution of 50 to 60 g/l potassium permanganate and 20 to 40 g/l sodium hydroxide at about 160 degrees F can completely remove the black, surface-modified layer and restore the original TEFLON properties with only about a 10-second treatment time. Alkaline peroxydisulfate is also effective, but slower. Both processes are faster than the previously used method involving an hour immersion time at room temperature in bleach [*], a process which does not completely remove the modified layer. Alkaline sodium chlorite has only a mild effect on the black layer.

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Removal of Surface Layer From Treated TEFLON

Alkaline oxidizing solutions have been found to be very effective in removing the dark brown-to-black surface layers produced by treatment of TEFLON* with strong reducing agents such as non-aqueous solutions of sodium napthalenide. In particular, a solution of 50 to 60 g/l potassium permanganate and 20 to 40 g/l sodium hydroxide at about 160 degrees F can completely remove the black, surface-modified layer and restore the original TEFLON properties with only about a 10-second treatment time. Alkaline peroxydisulfate is also effective, but slower. Both processes are faster than the previously used method involving an hour immersion time at room temperature in bleach [*], a process which does not completely remove the modified layer. Alkaline sodium chlorite has only a mild effect on the black layer. Acidic oxidizing agents such as a mixture of chromium trioxide and sulfuric acid have little effect on this layer. * Trademark of E. I. du Pont de Nemours & Co.

Reference: D. W. Dwight and W. M. Riggs, "Fluoropolymer Surface Studies,"
J. Colloid and Interface Science 47, 3, 655 (June 1974).

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