LASER INDUCED IMAGING OF POSITIVE WORKING RADIATION SENSITIVE COMPOSITIONS CONTAINING A LARGE PROPORTION OF CARBON BLACK

摘要

Radiation sensitive lithographic compositions suitable for laser inducedimaging, which contain a positive working radiation sensitive compound, anaqueous alkali soluble resin and a relatively large proportion of carbon black.Such compositions, when coated on a metal substrate and imagewiseexposed to laser induced infrared radiation form a positive image afterdevelopment with an aqueous alkaline solution. Exposing is conducted withlaser light at a wavelength in the range of from about 800 to about 1100 nmat an energy level of from about 50 to about 250 mJ/cm2.