the coating was exposed to the ultraviolet light of an ultra high pressure mercury lamp having an illuminance of 5 0 mw cm 2 for a dose of 50 mj cm 2 through a mask having a predetermined pattern subsequently the photocured resin was spray developed with ion exchange water for 30 seconds to thereby obtain an objective pattern the pattern had a film thickness of 5 u03bcm and the sensitivity of the resin as evaluated on the basis of the ugra step tablet was 8 the photosensitive resin solution was stored at 40 u00b0 c and variation in patterning characteristic was evaluated the results indicated that no variation in patterning characteristic was observed even after the solution had been stored for two weeks a vinyl acetate polymer polymerization degree 1100 saponification degree 80 100 g was dissolved in water 676 g and to the solution n methyl u03b3 p formylstyryl quinolinium metosulfate hereinafter referred to as sqq 8 3 g and oxalic acid 4 g were added followed by stirring at 30 u00b0 c for six hours propylene glycol 477 g and n butyl aldehyde 11 0 g were then added to the reaction mixture followed by further stirring at 30 u00b0 c for 14 hours ion exchange resin amberlyst ira 45 product of rohm amp haas co 52 ml was added to the solution and the resultant mixture was stirred at 50 u00b0 c for four hours to thereby neutralize the solution then the ion exchange resin was removed from the mixture through filtration subsequently propylene glycol 321 g and cyclohexane 50 g were added to the filtrate and the resultant mixture was subjected to azeotropic dehydration at 74 u00b0 c cyclohexane was removed from the mixture through distillation at 81 u00b0 c.