CLAIMS
[Claim 1]
A presensitized plate comprising: a photosensitive layer containing (A) a sensitizing dye, (B) a polymerization initiator, (C) a polymerizable compound, and (D) a binder polymer; and a protective layer which are formed on a support in this order,
wherein the support is prepared from an aluminum alloy plate containing intermetallic compound particles with a circle equivalent diameter of 0.2 um or more at a surface density of 35,000 pcs/mm2 or more and aluminum carbide particles with a maximum length of 1 um or more in an amount of up to 30,000 pcs/g.
[Claim 2]
The presensitized plate according to claim 1, including the photosensitive layer having a weight ratio of the polymerizable compound to the binder polymer (polymerizable compound weight / binder polymer weight) of 2 to 4.
[Claim 3]
The presensitized plate according to claim 1 or 2, wherein the sensitizing dye is one having an absorption maximum at 350 to 450 nm.
[Claim 4]
The presensitized plate according to any one of claims 1 to 3, wherein the protective layer comprises a composition containing polyvinyl alcohol.
[Claim 5]
A presensitized plate comprising: an image recording layer containing (E) an infrared absorbing dye and (F) hydrophobic thermoplastic particles and formed on a support,
wherein the support is prepared from an aluminum alloy plate containing intermetallic compound particles with a circle equivalent diameter of 0.2 um or more at a surface density of 35,000 pcs/mm2 or more.
[Claim 6]

The presensitized plate according to claim 5, wherein the hydrophobic thermoplastic particles are styrene-acrylonitrile particles.
[Claim 7]
A presensitized plate comprising: an image recording layer containing (G) a sensitizing dye, (H) a polymerization initiator, (1) a polymerizable compound, and (J) a polymer and formed on a support, unexposed portions'of the image recording layer removed with printing ink and/or fountain solution,
wherein the support is prepared from an aluminum alloy plate containing intermetallic compound particles with a circle equivalent diameter of 0.2 urn or more at a surface density of 35,000 pcs/mm2 or more.
[Claim 8]
The presensitized plate according to claim 7, comprising an oxygen shield layer on the image recording layer. [Claim 9]
The presensitized plate according to claim 7 or 8, comprising no oxygen shield layer on the image recording layer.
[Claim 10]
The presensitized plate according to any one of claims 7 to
9, wherein the polymer (J) has an alkylene oxide chain.
[Claim 11]
The presensitized plate according to any one of claims 7 to
10, wherein the polymer (J) is particulate.
[Claim 12]
The presensitized plate according to any one of claims 5 to
11, wherein Al-Fe intermetallic compounds of the aluminum alloy
plate have peak count values as measured with an X-ray
diffractometer (XRD) of up to 400 cps.
[Claim 13]
The presensitized plate according to any one of claims 5 to
12, wherein AlFeSi intermetallic compounds of the aluminum alloy
plate have peak count values as measured with an X-ray
diffractometer (XRD) of up to 30 cps.

[Claim 14]
The presensitized plate according to any one of claims 5 to 13, wherein a micropore-bearing anodized film is formed on a surface side of the support on which the image recording layer is to be formed, an average pore size in a surface layer of the anodized film is from 10 to 75 ma, and a ratio of an average of a maximum diameter inside pores to the average pore size is from 1.1 to 3.0.
[Claim 15]
A presensitized plate comprising: an image recording layer containing (K) an infrared absorber and (L) an alkali-soluble resin and formed on a support, exposed portions of the image recording layer having an increased alkali solubility after exposure to infrared radiation,
wherein the support is formed from an aluminum alloy plate containing intermetallic compound particles with a circle equivalent diameter of 0.2 um or more at a surface density of more than 35,000 pcs/mm2.
[Claim 16]
The presensitized plate according to claim 15, wherein the alkali-soluble resin (L) is a phenol resin.
[Claim 17]
The presensitized plate according to claim 16, wherein the phenol resin is a novolac resin.
[Claim 18]
The presensitized plate according to any one of claims 5 to
17, wherein the aluminum alloy plate contains intermetallic
compound particles with a circle equivalent diameter of 1.0 um
or more at a density of up to 2,500 pcs/mm2.
[Claim 19]
The presensitized plate according to any one of claims 1 to
18, wherein the aluminum alloy plate is manufactured by a
continuous casting process.
[Claim 20] The presensitized plate according to claim 19, wherein the

aluminum alloy plate is obtained by the continuous casting process which includes feeding an aluminum alloy melt through a melt feed nozzle between a pair of cooling rollers and rolling the aluminum alloy melt while solidifying with the pair of cooling rollers. [Claim 21]
The presensitized plate according to any one of" claims 1 to 20, wherein the support is one obtained by subjecting a surface of the aluminum alloy plate to surface roughening treatment including electrochemical graining treatment. [Claim 22]
The presensitized plate according to claim 21, wherein the surface roughening treatment is one including anodizing treatment following the electrochemical graining treatment.
[Claim 23]
The presensitized plate according to claim 22, wherein the anodizing treatment is one using an electrolytic solution containing sulfuric acid or phosphoric acid.
[Claim 24]
A method of manufacturing a lithographic printing plate comprising the steps of: performing image recording on the presensitized plate according to claim 5 or 6; and rubbing a plate■surface with a rubbing member in the presence of a treatment solution in an automatic processor equipped with the rubbing member to remove non-image areas of the image recording layer.
[Claim 25]
A 'method of manufacturing a lithographic printing plate comprising:
an image recording step for recording an image on the presensitized plate according to any one of claims 15 to 17 by imagewise exposure; and
a development step for developing the presensitized plate having the image recorded thereon with a developer at a pH of 9 or more to obtain the lithographic printing plate.