Summary for black dye used in anodizing Discussion
Black dye used in anodizing process is the focus of this thread, where Alex Ko asked where to find the possible chemical contents of black anodizing dyes after fluorescence tests showed different spectra on black anodized aluminum plates. Ted Mooney replied that the best source is the MSDS from each anodizer, but warned that this may not reveal much because the dye formulations are proprietary and closely guarded by manufacturers. Ken Vlach added that *The Surface Treatment of Aluminum and Its Alloys* discusses dyeing and mentions one black dye of the anthraquinone type, which may help identify chemical classes and how they bond in anodic pores. He also suggested that some spectral variation may come from the sealing chemistry and from the anodic coating itself, which can contain varying amounts of sulphate. The thread later shifts to an unrelated request from a biologist asking generally about dyes and azo dyes.
Q. We have recently ran some fluorescence tests on black anodized Al plates and they show different fluorescence spectra. My question is where I can find out all the possible contents (chemical composition) in the black dye normally used for anodizing process.
Thanks for the help,
Alex Ko
– Kingston, Ontario, Canada
2003
 | A. These dyes are proprietary so no one is going to tell you their chemical composition. But there are many formulations and they are very different. One important difference is that some are ultra dark red dyes and some are ultra dark blue dyes — and they can look very different in artificial light situations. I remember a manufacturer of audio components having to correct this issue of their black equipment being a mix of dark red and dark blue under dim stage lighting.
2003 “The Surface
on Amazon or or A. Request the MSDS for the dye from each anodizer. This info probably won’t satisfy you; you are seeking proprietary information which the dye manufacturers jealously guard. The Surface Treatment of Aluminum and Its Alloys. I will speculate that some spectral variation is due to the sealing chemistry and the anodic coating itself, which contains varying amounts of sulphate. Ken Vlach [deceased]
– Goleta, California 2003 |
Q. Dear Sir/Madam,
I am a biologist doing my Ph.D and I would like to know basically about dye and its structure, composition, types and especially more about azodyes. I am interested in it as I am going a project about the biotransformation of azodyes by soil microbes. Kindly reply.
Thank you sincerely,
Shyamala [surname deleted for privacy by Editor]
– Chennai, Tamilnadu, India
2003