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Re: NEON- Phosphor Binder



Hey Frank and Tom,

NO, please don't take pure phosphorous, either the white, red or black!

What we (the Europies) use to adhere the luminous powder (also called phosphor) to the 
inner side of the tube is mostly a mixture of 
15 vol % concentrated orthophosphoric acid (H3PO4) of 68% content
85 vol % methanol or ethanol (C2H5OH, well known formula...)

The mixture will get hot during preparation, because the alcohol forms 
esters (should be C2H7PO4 + H2O, but not sure at the moment). 
So the binder is a mixture of orthophosphoric methyl ester, remaining 
orthophosphoric acid and suplus alcohol. 
What happens when this comes to the glass: The acid will etch the surface, 
The alcohol is for regular distribution and solving the rest of water for 
co-evaporation, and the ester does the binding when the powder is applied. 

(The exact chemistry is much complicated, but this seems this is enough for
understanding the main mixture)

Marcus

> Frank had asked me a question re. the sponge coating binder in my video and
> asked me to pass this post & response to the list.
> 
> >> >Hi Tom,
> >> >
> >> >BTW do you know what the binder is that they used when coating the
> >> >tubes?
> >>
> >> Frank-
> >>
> >> I'm not so familiar with the terms and we struggled to come up with the
> >> English translation of the words the Dutch were using for the contents.
> >> But, what they told me (several sources) was that it consists of Phosphorus
> >> (30%) and medically pure Alcohol (70%).  I think it was perhaps secretive
> >> because it is also sold as a premixed binder.
> >>
> >> Let me know if you try it...or are familiar with "Phosphorus."
> >>
> >> Tom
> 
> 
> 


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