Browse Prior Art Database

IMAGING METHOD BASED ON PHOTO-INDUCED DEPOLYMERIZATION OF POLY(ACETALDEHYDE)

IP.com Disclosure Number: IPCOM000022797D
Original Publication Date: 1976-Feb-29
Included in the Prior Art Database: 2004-Mar-26
Document File: 2 page(s) / 188K

Publishing Venue

Xerox Disclosure Journal

Abstract

Poly(acetaldehyde) is prepared with photodegradable end~-caps such as phenyl glyoxylate groups. The end~-caps may be destroyed by direct irradiation or by photosensi~ tization with an appropriate sensitizer having a (n,lT *) triplet state whose energy is greater than the triplet energy of phenyl glyoxylate, e.g. benzophenone. Upon destruction of the end~caps, the polymer depolymerizes to the monomeric state which is a gas at ambient tempera~ tures. when the poly(acetaldehyde) is dispersed in a suitable passive matrix, preferably of a thermoplastic resinous material, the depolymerization reaction in the light struck areas results in the liberation of molecular acetaldehyde and the coalescence of these molecules to

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

XEROX DISCLOSURE JOURNAL

IMAGING METHOD BASED ON PHOTO~- Proposed Classification

INDUCED DEPOL~4ERIZATION OF U.S. Cl. 96/48
~ mt. Cl, G03c 5/24
William W. Limburg
Dana G. Marsh

Poly(acetaldehyde) is prepared with photodegradable
end~-caps such as phenyl glyoxylate groups. The end~-caps

may be destroyed by direct irradiation or by photosensi~
tization with an appropriate sensitizer having a (n,lT *)
triplet state whose energy is greater than the triplet
energy of phenyl glyoxylate, e.g. benzophenone. Upon
destruction of the end~caps, the polymer depolymerizes
to the monomeric state which is a gas at ambient tempera~
tures. when the poly(acetaldehyde) is dispersed in a
suitable passive matrix, preferably of a thermoplastic
resinous material, the depolymerization reaction in the
light struck areas results in the liberation of molecular
acetaldehyde and the coalescence of these molecules to

form micro bubbles which are trapped in the matrix, These
micro bubbles form light scattering centers which create
a visible image. Mild heating or infrared irradiation
causes the micro bubbles to expand thereby enhancing the
image.

Volume 1 Number 2 February 1976 17

[This page contains 1 picture or other non-text object]

Page 2 of 2

18 XEROX DISCLOSURE JOURNAL

Volume 1 Number 2 February 1976

[This page contains 1 picture or other non-text object]