Negative-acting photolithographic printing plate with improved pre-burn performance

[0069]A solution in Dowanol™ solvent PM (Dow Chemical Wilmington, Del.) and MEK consisting of 2 g of the acetal resin 1 0.02 g of CYMEL™ 303 (American Cyanamid Co., Wayne, N.J.), 0.02 g TTT, (2,4,6-tris(trichloromethyl)-1,3,5-triazine PCAS, France), 0.0072 g malachite green (Aldrich Chemicals, Milwaukee, Wis.) and 0.003 g of 2,2-bis(hydroxymethyl)-2,3-dihydro-1H-perimidine based squarylium dye made according to U.S. Pat. No. RE 38,251 1d was coated with a No. 6 coating rod (R&D Specialties, Webster, N.Y.) onto 200 micron-thick grained and anodized aluminum printing plate base and dried in an oven at 90° C. for 3 minutes.

[0070]A solution in Dowanol™ solvent PM (Dow Chemical Wilmington, Del.) and MEK consisting of 2 g of the acetal resin 2 0.02 g of CYMEL™ 303 (American Cyanamid Co., Wayne, N.J.), 0.02 g TTT, (2,4,6-tris(trichloromethyl)-1,3,5-triazine PCAS, France), 0.0072 g malachite green (Aldrich Chemicals, Milwaukee, Wis.) and 0.003 g of 2,2-bis(hydroxymethyl)-2,3-dihydro-1H-perimidine based squarylium dye made according to U.S. Pat. No. RE 38,251 1d was coated with a No. 6 coating rod (R&D Specialties, Webster, N.Y.) onto 200 micron-thick grained and anodized aluminum printing plate base and dried in an oven at 90° C. for 3 minutes.

[0071]The plates thus prepared of comparative example 1, example 2 and example 3 were imaged on a Newsetter® 70 made by Creo, Inc. using 15 W. Plates were subsequently pre-heated at a range of temperatures and developed in 830N developer (Southern Lithoplate Inc., Youngsville, N.C.) for 30s, the exposed areas remained and the unexposed areas were washed off to leave a n

[0072]A solution in Dowanol™ solvent PM (Dow Chemical Wilmington, Del.) and MEK consisting of 2 g of the acetal resin 1 0.02 g of CYMEL 303 (American Cyanamid Co., Wayne, N.J.), 0.02 g TTT, (2,4,6-tris(trichloromethyl)-1,3,5-triazine PCAS, France), 0.0072 g crystal violet (Aldrich Chemicals, Milwaukee, Wis.). 0.003 g of 2,2-bis(hydroxymethyl)-2,3-dihydro-1H-perimidine based squarylium dye made according to U.S. Pat. No. RE 38,251 1d and 0.001 g surfactant FC430 (Minnesota Mining and Manufacturing Co), was coated with a No. 6 coating rod (R&D Specialties, Webster, N.Y.) onto 200 micron-thick grained and anodized aluminum printing plate base and dried in an oven at 90° C. for 3 minutes. The plates of comparative example 1, example 2 and example 3 were imaged on a Newsetter™ 70 made by Creo, Inc. using 15 W. Plates were subsequently pre-heated at a range of temperatures and developed in 830N developer Southern Lithoplate, Youngsville, N.C.) for 30 seconds (s), the exposed areas remained a