I'm writing to see if any of you have information about historical lacquer
formulas used to make instantaneous discs in the 1930s-1950s.
At NEDCC we're trying to develop conservation treatments for delaminating
discs, but we need some more background info about the chemistry of the
lacquer to make sure there are no surprise reactions.
From Pickett & Lemcoe and Paton et al. (1997) I understand that it's
nitrocellulose lacquer plasticized with castor oil. Contemporary sources
mention that other resins, lubricants, dyes and solvents may have been added
as well, but I can't find out what these were, or in what proportions.
If any of you have historical formulations or chemical analyses of the
lacquer, or know somebody I should get in contact with, I'd appreciate it.