Thermographic recording material with improved image tone

US6693062B2 · kind B2 · utility

Assignee

• Agfa-Gevaert NV · BE

Inventors

• Philip Dooms · Edegem, BE
• Ivan Hoogmartens · Wilrijk, BE
• Geert Defieuw · Kessel-Lo, BE

Key dates

• Filing date: Jun 27, 2002
• Grant date: Feb 17, 2004
• Expiry date: Sep 13, 2022

Classification

• Technology area (CPC G): Physics
• CPC primary: G03C1/4989
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A monosheet black and white substantially light-insensitive thermographic recording material comprising a thermosensitive element and a support, the thermosensitive element containing one or more substantially light-insensitive organic silver salts, one or more reducing agents consisting of one or more 1,2-dihydroxybenzene-compounds in thermal working relationship therewith and a binder, wherein the molar ratio of molar hydroxy-equivalents of the 1,2-dihydroxybenzene compounds to molar silver-equivalents of the substantially light-insensitive organic silver salts is between 1.2 and 6.0; the 1,2-dihydroxybenzene-compounds have a &#8212;(CH&boxH;CH)nR group in the 4 position wherein n is zero or an integer and R is a substituent with a Hammett &sgr;p constant >0.35 and <0.95 exclusive of a carboxy-group; and the benzene ring of the 1,2-dihydroxy-compounds is optionally further substituted with an entity selected from the group consisting of an alkyl, substituted alkyl, alkenyl, aryl, heteroaryl, alkoxy, thioalkyl, aryloxy, thioaryl, thioheteroaryl, acyloxy, thioacyl, amido, sulphonamido and halogen groups, an annelated aryl ring system and an annelated heteroaryl ring system; and a t…