Date:         Thu, 3 Mar 2005 00:15:29 -0500
Reply-To:     Association for Recorded Sound Discussion List
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Sender:       Association for Recorded Sound Discussion List
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From:         "Richard L. Hess" <[log in to unmask]>
Subject:      Re: Info on Zonal tape required
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At 10:26 PM 3/2/2005, Scott Smith wrote:
>Also, to the best of my knowledge, there aren't any cases of binder
>hydrolysis related to acetate base material. (Richard Hess or Jim Wheeler
>may have some other commentary on this).

I agree with that assessment. But we should be clear that binder hydrolysis
is related to the chemistry of the binder and has (to the best of my
knowledge) nothing to do with the backing, other than certain backings were
used during times when binders were not prone to binder hydrolysis.

Another interesting note: acetate tape is theoretically subject to vinegar
syndrome which is an autocatalytic process. The last time Jim Wheeler and I
had talked about it, we hadn't seen any significant quantities of VS in
tape, while it is prevalent in film and devastating in mag film (the iron
is a catalyst).

One theory that I have (which has yet to be confirmed) is that the typical
cardboard box we store tape in potentially acts as an absorber of the
excess acetic acid. We all know that old tapes seem to be stored in
high-acid-content boxes. My question is were they made that way, or did
they absorb acid from the tape?

Cheers,

Richard

Richard L. Hess                           email: [log in to unmask]
Vignettes
Media                           web:   http://www.richardhess.com/tape/
Aurora, Ontario, Canada             (905) 713 6733     1-877-TAPE-FIX