A Silver-Free, Single-Sheet Imaging Medium Based on Acid Amplification
John L. Marshall,*
Stephen J. Telfer,*
Michael A. Young,
Edward P. Lindholm,
Richard A. Minns,
Larry Takiff
We describe a photographic medium that uses acid-amplified imaging
(AAI) rather than silver halide development to amplify a latent image.
The latent image is captured when small amounts of superacid are
generated by the photolysis of iodonium salts sensitized by cationic
dyes. During thermal processing, the quantity of acid is multiplied in
a process catalyzed by strong acid, resulting in a much larger amount
of a weaker acid. Acid-sensitive indicator dyes that diffuse into
regions where acid has been produced form a colored image. The AAI
system is not sufficiently sensitive for direct use in cameras but is
suitable for many printing applications.
Instant Digital Printing, Polaroid Corporation, 1265 Main Street,
Building W4, Waltham, MA 02451, USA.
*
To whom correspondence should be addressed. E-mail:
marshaj{at}polaroid.com (J.L.M.); telfers{at}polaroid.com
(S.J.T.)
Present address: Flexplay Technologies Inc., 3H Gill Street,
Woburn, MA 01801, USA.
Present address: Aprilis, Inc., 5 Clock Tower Place, Suite
200, Maynard, MA 01754, USA.
