| 摘要 |
A presensitized plate for use in making a lithographic printing plate requiring no fountain solution excellent in scratch resistance and press life is disclosed, which comprises support and, formed thereon in order from support, a photosensitive layer and a silicone rubber layer, wherein the silicone rubber layer is a crosslinked and cured product obtained by addition reaction of (a) polysiloxane having alkenyl groups with (b) hydrogen polysiloxane having 3BOND Si-H groups so that the number of 3BOND Si-H groups in (b) is from 11 to 30 based on the number of alkenyl groups in (a), wherein polysiloxane (a) has at least two alkenyl groups directly bonded to silicon atoms per molecule, average repeating number x of -[Si(R1)(R2)-O]x- group of 100 </=x</=600 (wherein R1 and R2 each represents a alkyl group, aryl group, aralkyl group, alkenyl group, polydimethylsiloxane group or halogenated hydrocarbon group, provided that 70% or more of R1 and R2 are methyl groups), and alkyl groups or alkenyl groups directly bonded to the terminal silicon atoms, and wherein the hydrogen polysiloxane (b) is formula (I): R3-Si(R4)2-O-[SiH(R4)-O]y-[Si(R4)2-O]z-Si(R4)2-R3 (I) wherein R3 represents a hydrogen atom or a methyl group; R4 represents an alkyl group, an aryl group, or an aralkyl group, provided that 70% or more of R4 is a methyl group; y is from 4 to 100, and z is from 0 to 100.
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