Patent ID: 6881532

Claim:
A method of processing a light sensitive planographic printing plate precursor comprising a support, and provided thereon, a light sensitive layer and an overcoat layer in that order, the method comprising the steps of: imagewise exposing the light sensitive planographic printing plate precursor; pre-washing the exposed light sensitive planographic printing plate precursor with a pre-washing solution in the presence of a compound represented by the following formula (1) or (2), or an N-alkyliminodiacetic acid or its salt, the alkyl being a methyl group, an ethyl group, a propyl group, an isopropyl group, a hydroxyl group-substituted methyl group, a hydroxyl group-substituted ethyl group, a hydroxyl group-substituted propyl group, or a hydroxyl group-substituted isopropyl group; and developing the pre-washed light sensitive planographic printing plate precursor with a developer, wherein A 1 , A 2 , A 3 , and A 4 independently represents —CH 2 OH, —PO 3 (M 1 ) 2 , or —COOM, in which M and M 1 independently represent a hydrogen atom, an ammonium group, an alkali metal atom or an organic ammonium group, and may be the same or different; and X represents an alkylene group having a carbon atom number of 2 to 4 or —(B 1 O) n —(B 2 )—, in which B 1 and B 2 independently represent an alkylene group having a carbon atom number of 1 to 5, and may be the same or different, and n is an integer of 1 to 8, wherein X1, Y and Z independently represents —CH 2 —, —(CH 2 ) 2 —, or —CHOH—, and n1 is 0 or 1.