Method of manufacturing lithographic printing plate

Abstract

A method for manufacturing a lithographic printing plate is provided in which conditions for heating a support and a photosensitive coated layer in a drying and heating step can be changed rapidly over a wide range, and the photosensitive coated layer and the support are heated without being contacted.

1 . A method for manufacturing a lithographic printing plate, the method comprising:
 conveying a support, on which a photosensitive coating solution containing an organic solvent is coated such that a photosensitive coated layer is formed by the photosensitive coating solution;   drying the photosensitive coated layer by a first heating means to a dry-to-touch state;   heating the support and the photosensitive coated layer by a second heating means, which does not contact the support and the photosensitive coated layer, and which is provided at a downstream side of the first heating means, so that hardening of the photosensitive coated layer is promoted; and   changing an amount of heat supplied by the second heating means while the support is being conveyed,   wherein a conveying speed of the support is constant irrespective of a thickness of the support.   
     
     
         2 . The method for manufacturing a lithographic printing plate according to  claim 1 , wherein a thickness of the support is from 0.15 to 0.40 mm. 
     
     
         3 . The method for manufacturing a lithographic printing plate according to  claim 1 , wherein a heating condition of the second heating means is set in accordance with the thickness of the support. 
     
     
         4 . The method for manufacturing a lithographic printing plate according to  claim 3 , wherein the second heating means comprises a far infrared radiation heating device. 
     
     
         5 . The method for manufacturing a lithographic printing plate according to  claim 1 , wherein the first heating means heats the photosensitive coated layer to 90° C. or more. 
     
     
         6 . The method for manufacturing a lithographic printing plate according to  claim 1 , wherein the first heating means dries the photosensitive coated layer such that a remaining amount of the organic solvent in the photosensitive coated layer is 5 wt % or less of the photosensitive coated layer. 
     
     
         7 . The method for manufacturing a lithographic printing plate according to  claim 1 , wherein a heating system of the second heating means is a heat radiation system. 
     
     
         8 . The method for manufacturing a lithographic printing plate according to  claim 1 , wherein a heating system of the second heating means is an induction heating system. 
     
     
         9 . The method for manufacturing a lithographic printing plate according to  claim 1 , wherein the condition of heating by the second heating means is controlled in accordance with a type of the photosensitive coated layer formed on the support, such that a temperature of the photosensitive coated layer immediately after heating by the second heating means is a predetermined temperature which is set in accordance with the type of the photosensitive coated layer. 
     
     
         10 . The method for manufacturing a lithographic printing plate according to  claim 1 , further comprising forcibly cooling the support and the photosensitive coated layer by a cooling means provided at a downstream side of the second heating means. 
     
     
         11 . The method for manufacturing a lithographic printing plate according to  claim 10 , wherein the cooling comprises blowing air from an air-cooling system toward the photosensitive coated layer. 
     
     
         12 . The method for manufacturing a lithographic printing plate according to  claim 10 , further comprising forming an overcoat layer on the photosensitive coated layer after the cooling of the support and the photosensitive coated layer. 
     
     
         13 . The method for manufacturing a lithographic printing plate according to  claim 1 , wherein a heating condition of the second heating means is changed within one minute. 
     
     
         14 . A method for manufacturing a lithographic printing plate, the method comprising:
 conveying a support, on which a photosensitive coating solution containing an organic solvent is coated such that a photosensitive coated layer is formed by the photosensitive coating solution;   drying the photosensitive coated layer by a first heating means to a dry-to-touch state;   heating the support and the photosensitive coated layer by a second heating means, which does not contact the support and the photosensitive coated layer, and which is provided at a downstream side of the first heating means, so that hardening of the photosensitive coated layer is promoted; and   changing an amount of heat supplied by the second heating means while the support is being conveyed,   wherein a heating condition of the second heating means is changed within one minute.   
     
     
         15 . The method for manufacturing a lithographic printing plate according to  claim 14 , wherein the second heating means comprises a far infrared radiation heater. 
     
     
         16 . The method for manufacturing a lithographic printing plate according to  claim 14 , further comprising forcibly cooling the support and the photosensitive coated layer by a cooling means provided at a downstream side of the second heating means. 
     
     
         17 . The method for manufacturing a lithographic printing plate according to  claim 16 , wherein the cooling comprises blowing air from an air-cooling system toward the photosensitive coated layer. 
     
     
         18 . The method for manufacturing a lithographic printing plate according to  claim 16 , further comprising forming an overcoat layer on the photosensitive coated layer after the cooling of the support and the photosensitive coated layer.