High Performance Coatings              

DEPARTMENT OF NAVY
NAVAL RESEARCH LABORATORY
4555 OVERLOOK AVE SW
WASHINGTON DC 20375-5320

IN REPLY REFER TO



21st Century Coatings, Inc.
301 N. Fairfax Street
Alexandria, VA 22314

3 February 1997

Dear 21st Century,

This is in response to your inquiry concerning the availability of test data concerning PTFE pigmented fluoropolyurethanes. During the past year or more extensive searches for the original papers have been conducted in our files to find the relevant test data. These searches have been relatively fruitless for a number of reasons. First and foremost among the reasons is because of the nature of how the product was developed, i.e., not funded by any one specific program. Next, Don Field passed away and I believe that many of the notes are in his personal files, no longer available to us here at NRL. Lastly, I would also guess that some of the files have been misplaced over the past twenty-five years.

I have just finished conducting a review of some of the literature where we reported on our findings concerning this unique coating system. I can categorically state that the test results that we reported in these papers were accurate and as you yourself have recently shown, can be duplicated. I have reviewed the list of test results and identified the paper where that test was reported in the following list:

REPORT/PAPER

Carderock Division, Naval Surface Warfare Centre, Ships Materials Engineering Department Research and Development report CADEROCKDIV-SME-90-89 July 1992, "Evaluation of New Coating Systems on SSBN-726 Class Submarines"

ASTM B-117 Salt fog 3200 hours no deterioration (page 35)
Navy sewage immersion test - passed with no deterioration (pages 33 & 36)
Navy DTNSMDC/SME-85/23 Hot water immersion test - passed (page 32)

"Fluorinated Polyepoxy and Polyurethane Coatings" by Donald E. Field, Naval Research Laboratory. Presented at the 53rd annual meeting of the Federation of Societies for Coating Technology in Los Angeles, CA, 30 October 1975 and printed in the Journal of Coatings Technology, Volume 48, No. 615, April 1976.

ASTM-B287-62 Acidulated Salt Fog 1500 hours - no deterioration (page 45)
MIL-C-81773 A/AS all tests - passed (page 45)
NRL marine boring organism barrier test for five months - no penetration (page 46)
Weather-Ometer tests projected an extended weather durability (page 45)

"Fluorinated Naval Coatings" by James R. Griffith and John D. Bultman, Naval Research Laboratory. Presented at the Division of Organic Coatings and Plastics Chemistry, 173rd National Meeting of the American Chemical Society, New Orleans, LA 22 March 1977 and published by the American Chemical Society, 1978.

Low water absorption - six months immersion 0.35% by weight (page 1)
Hydrophobicity as it relates to corrosion prevention (page 1)
Marine fouling at underwater interfaces tests (page 2)

"Cross-Linked Fluoropolymer Coatings" by Donald E. Field and James R. Griffith, Naval Research Laboratory, printed in the Industrial and Engineering Chemical Product Research and Development, Vol. 14, page 52, March 1975 by the American Chemical Society.

Surface tension tests (18 dyn/cm) (page 53)
Ultraviolet light exposure - essentially unaffected (page 53)
Low coefficients of friction (0.10-0.19 static and 0.04-0.08 kinetic) (page 54)
Over 15 aircraft tests evaluating fluoropolyurethane vs. aircraft acrylic (MIL-L-81352), epoxy-polyamide (MIL-C-232750C) and aliphatic polyurethane (MIL-C-81773A/AS) - superior in all respects (page 54)

I have observed that during the past year you have conducted several of the above tests with similar results, such as ASTM-B117 Salt Fog for 4775 hours and 28 weeks of NRL Fuel Storage lining test involving immersion in distilled water, JP5 fuel and air at 135 deg. F.

I hope that the above information helps answer the question regarding test data for this unique coating system.


Desmond Sheehan
Head, Materials Chemistry Branch
Chemistry Division
Code 6120