On Apr 8, 2016, at 3:11 PM, Tom Gardner <t.gardner
at computer.org> wrote:
 Sorry, to a EE they are all epoxies, but:
 "BINDER: A polymer such as polyester-polyurethane used to bind magnetic
 particles together and adhere them to the base film in the manufacturing of
 magnetic media."
 
http://www.fujifilmusa.com/shared/bin/Magnetic_Media_Terminology.pdf
 "Polyester polyurethane is the workhorse of polyurethane films. It offers
 excellent strength and long-term stability"
 
http://www.apiusa.com/polyesterpolyure.html
 I think properly cured all binders used are pretty stable. 
That may be, but if so, there are some big name vendors who do not know
"properly".
        paul