Photosensitive composition

1. A photosensitive composition comprising (i) a titanocene compound, (ii) a compound selected from a pyridine compound represented by formula (1) shown below and a cyan compound represented by formula (3) shown below, and (iii) a compound capable of undergoing a reaction with at least one of a radical and an acid to irreversibly change its physical or chemical property:

wherein R 1 , R 2 , R 3 , R 4 and R 5 each independently represents a hydrogen atom, a halogen atom or an organic group, or at least one of R 1 and R 2 , R 2 and R 3 , R 3 and R 4 , and R 4 and R 5 may be combined with each other to form a ring, provided that at least one of R 1 , R 2 , R 3 , R 4 and R 5 represents an organic group represented by formula (2) shown below, and wherein when R 1 or R 5 represents an organic group represented by formula (2), R 3 represents a hydrogen atom, a halogen atom, an alkyl group, a substituted alkyl group, an aryl group, an alkenyl group, a substituted alkenyl group, an alkynyl group, a substituted alkynyl group, a hydroxy group, a substituted oxy group, a mercapto group, a substituted thio group, an amino group, a substituted amino group, a substituted carbonyl group, a sulfo group, a sulfonato group, a substituted sulfinyl group, a substituted sulfonyl group, a phosphono group, a substituted phosphono group, a phosphonato group, a substituted phosphonato group, a cyano group, a nitro group or a silyl group;

wherein R 6 , R 7 and R 8 each independently represents a hydrogen atom, a halogen atom or an organic group, or R 7 and R 8 , R 6 and R 7 , or R 6 and R 8 may be combined with each other to form a ring; and L represents a divalent connecting group containing a hetero atom;

wherein R 1′ , R 2′ and R 3′ each independently represents a hydrogen atom, a halogen atom or an organic group, or R 1′ and R 2′ , R 2′ and R 3′ , or R 1′ and R 3′ may be combined with each other to form a ring; and L represents a divalent connecting group containing a hetero atom.

2. The photosensitive composition as claimed in claim 1 , wherein the compound of (ii) is the pyridine compound represented by formula (1).

3. The photosensitive composition as claimed in claim 1 , wherein the compound of (ii) is the cyan compound represented by formula (3).

4. The photosensitive composition as claimed in claim 1 , wherein the compound capable of undergoing a reaction with at least one of a radical and an acid to irreversibly change its physical or chemical property is a compound having an ethylenically unsaturated double bond.

5. A lithographic printing plate precursor comprising a photosensitive layer including the photosensitive composition according to claim 1 .

6. A lithographic printing plate precursor comprising:

an aluminum support having a surface subjected to a surface roughening treatment; and

a photosensitive layer on the surface of the aluminum support, the photosensitive layer comprising the photosensitive composition of claim 1 .