WE CLAIM:
[Claim 1]
A precursor for lithographic printing comprising at least a heat
sensitive layer and an ink repellent layer wherein the ink
repellent layer has an elastic modulus of the plate surface
under the surface load of 14000 N/m2 of at least 25 MPa and up
to 35 MPa.
[Claim 2]
A precursor for lithographic printing according to claim 1
further comprising an organic layer provided on the heat
sensitive layer on the side opposite to the ink repellent layer.
[Claim 3]
A precursor for lithographic printing according to claim 2
wherein the organic layer contains at least 51% by weight and
up to 65% by weight of a polyurethane resin and at least 27%
by weight and up to 35% by weight of an epoxy resin.
[Claim 4]
A precursor for lithographic printing according to any one of
claims 1 to 3 wherein the ink repellent layer has a surface
roughness Ra of up to 0.40 µm.
[Claim 5]
A precursor for lithographic printing according to any one of
claims 1 to 4 wherein the ink repellent layer is a layer
comprising a silicone rubber.
[Claim 6]
A precursor for lithographic printing according to claim 5
wherein the silicone rubber has a structure derived from (a)
a SiH group-containing compound and (b) a vinyl
group-containing polysiloxane.
[Claim 7]
A precursor for lithographic printing according to claim 6
wherein, in solid 29Si NMR spectrum of the silicone rubber, the
peak corresponding to the dimethylsiloxane unit represented by
the following general formula (i) and the peak corresponding
to the siloxane unit represented by the following general
formula (ii) are observed, and ratio of the peak areas (ii)/(i)

is 0.00240 to 0.00900:
Si-O-Si*(CH3)2-O-Si (i)
-CH2-Si*(CH3)2-O-Si (ii) [Claim 8]
A precursor for lithographic printing according to any one of claims 1 to 7 wherein the ink repellent layer contains an ink repellent liquid, and the ink repellent liquid has a boiling point at 1 atmosphere of at least 150°C. [Claim 9]
A precursor for lithographic printing according to claim 8 wherein the ink repellent liquid has a surface tension at 25°C of at least 15 mN/m and up to 30 mN/m. [Claim 10]
A precursor for lithographic printing according to claim 8 or 9 wherein the ink repellent layer contains at least 4% by weight and up to 40% by weight of the ink repellent liquid. [Claim 11]
A precursor for lithographic printing according to claim 8 or 9 wherein the ink repellent layer contains at least 4.5% by weight and up to 14% by weight of the ink repellent liquid. [Claim 12]
A precursor for lithographic printing according to any one of claims 8 to 11 wherein the ink repellent liquid is a silicone oil.
[Claim 13]
A precursor for lithographic printing according to any one of claims 6 to 12 wherein the SiH group-containing compound (a) is a copolymer of siloxane structural unit represented by the following general formula (I) and siloxane structural unit represented by the formula (II):
-[SiH(CH3)-O-]- (I)
-[Si(CH3)2-O-]- (II) [Claim 14]
A precursor for lithographic printing according to claim 13 wherein content of the siloxane structural unit represented by the general formula (I) in relation to total (100% by mole) of

the siloxane structural unit represented by the general formula
(I) and the siloxane structural unit represented by the general
formula (II) in the SiH group-containing compound (a) is at
least 50% by mole.
[Claim 15]
A precursor for lithographic printing according to any one of
claims 6 to 14 wherein the vinyl group-containing polysiloxane
(b) has a weight average molecular weight of at least 30,000
and up to 100,000.
[Claim 16]
A precursor for lithographic printing according to any one of
claims 6 to 15 wherein molar ratio of number of the SiH groups
in the SiH group-containing compound (a) to number of the vinyl
groups in the vinyl group-containing polysiloxane (b) (number
of the SiH groups / number of the vinyl groups) is at least 2
and up to 6.
[Claim 17]
A lithographic printing plate produced by the steps of exposing
the precursor for lithographic printing of any one of claims
1 to 16 according to image, and developing the exposed precursor
and removing the ink repellent layer.
[Claim 18]
A method for producing a lithographic printing plate comprising
the steps of exposing the precursor for lithographic printing
of any one of claims 1 to 16 according to image, and developing
the exposed precursor and removing the ink repellent layer.
[Claim 19]
A method for producing a printed material comprising the steps
of allowing an ink to adhere to the surface of the lithographic
printing plate of claim 17, and transferring the ink to the
printing substrate either directly or via a blanket.
[Claim 20]
A method for producing a printed material according to claim
19 further comprising the steps of irradiating the ink
transferred to the printing substrate with an active energy ray.