Photosensitive recording material for use in the production of negative-working planographic printing plates with diazonium polycondensate and inorganic pigment

US4687726A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Gunter Schlogl · Kelkheim, DE
• Gerhard Mack · Bad Rodach, DE
• Manfred Michel · Wiesbaden, DE

Key dates

• Filing date: May 8, 1985
• Grant date: Aug 18, 1987
• Expiry date: May 8, 2005

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S430/151
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

Disclosed are a novel photosensitive recording material and a method for using the recording material in the production of planographic printing plates. The recording material comprises a support and a negative-working photosensitive layer that contains a diazonium salt polycondensation product as the photosensitive compound and, in addition, a colorless inorganic pigment which is insoluble in water and organic solvents and which has an average particle diameter from 1 to 20 .mu.m. The pigment is present in a quantity from 0.01 to 2% by weight, relative to the non-volatile constituents of the layer, and is evenly distributed in the layer. Due to the pigment content, a rough layer surface is formed, which has the effect of reducing the time required for creating a vacuum in a vacuum frame into which the recording material is mounted. The presence of the pigment in the layer also produces an improved tonal rendering in the print obtained.