Homebrew PCBs

Robert:

The much-repeated story about the banning of Dupont's Freon was that the 
patent was about to expire and that the material would become "generic" and
anyone would be able of manufacture it. So Dupont lobbied intensely (and 
successfully) to get the compound outlawed because of the "damage" it did to
the environment. The feds went for the story, and  Freon became highly 
restricted in the States, although it is still made and sold freely 
elsewhere.
Dupont had another compound that the feds immediately approved, and 
everyone went to using the new material.

I think that Freon is a lot heavier than atmosphere, and thus, when 
released into the atmosphere, it immediately drops to the ground where 
it is
absorbed. At least this is what a lot of people who worked with the 
stuff claimed.

So, the question is: was Dupont's claim about Freon being very dangerous 
to the environment really valid?
The stuff had been around for decades, and suddenly it was so bad it had 
to be restricted.

Roland F. Harriston, P.D.
*******************

Robert wrote:
>  
>
> Interesting...
>
> I can recall reading something about Dupont having been reported as 
> lobbying to ban hemp (not forming any opinions here, just saying I 
> read this) farming in the US during the 30s just as they had patented 
> then new wood pulp processing chemicals. we pretty much have all nylon 
> or cotton rope now, I don't know the specifics or if there may be any 
> similarity to the banning of resist chemical (in favor of Riston dry 
> film resists by Dupont), it might be stretching beyond I mean, but 
> then there are circumstances I am sure not at all uncommon where a 
> company has many pronged efforts to secure it's place, beyond just 
> making a really good product.
>



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