Process for generation of unbuffered super-acid and for imaging

US5578424A · kind A · utility

Assignee

• Polaroid Corporation · US

Inventors

• Jurgen M. Grasshoff · Hudson, US
• John Marshall · Somerville, US
• Richard A. Minns · Arlington, US
• Anthony J. Puttick · Arlington, US
• Lloyd D. Taylor · Lexington, US
• Stephen J. Telfer · Arlington, US

Key dates

• Filing date: Jan 20, 1995
• Grant date: Nov 26, 1996
• Expiry date: Jan 20, 2015

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S430/146
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

Acid can be generated by exposing a mixture of a superacid precursor and a dye to actinic radiation of a first wavelength which does not, in the absence of the dye, cause decomposition of the superacid precursor to form the corresponding superacid, thereby causing absorption of the actinic radiation and decomposition of part of the superacid precursor, with formation of a protonated product derived from the dye, then irradiating the mixture with actinic radiation of a second wavelength, thereby causing decomposition of part of the remaining superacid precursor, with formation of unbuffered superacid. Preferably, following these irradiations, the imaging medium is heated while the superacid is admixed with a secondary acid generator capable of being thermally decomposed to form a second acid, the thermal decomposition of the secondary acid generator being catalyzed by the presence of the superacid. The acid generation process may be used for imaging by bringing the superacid or second acid into contact with an acid-sensitive material which changes color on contact with acid, or the superacid may be used to trigger polymerization, depolymerization or other reactions.