Lithographic printing plates and processes for preparing the lithographic printing plates are provided. The plates have excellent printing durability, staining resistance and staining resistance over time. The lithographic printing plate precursor includes: a substrate; a photosensitive layer provided on the substrate; and an extra layer optionally provided between the substrate and the photosensitive layer. The photosensitive layer or the extra layer adjacent to the substrate contains (A) a copolymer. The copolymer (A) includes: (a1) a repeating unit of formula (a1-1) below in a side chain, and (a2) a repeating unit having at least one of the structures represented by formulae (a2-1) to (a2-6) shown in the specification in a side chain. L
1
, Z
1
, R
1
, and R
21
, R
22
and R
23
in formula (a1-1) and the variables in formulae (a2-1) to (a2-6) are as defined in the specification.
提供了用于制备平版印刷版和制备平版印刷版的过程。该版具有良好的印刷耐久性、耐污染性和随时间的污染性。平版印刷版的前体包括:基板;设置在基板上的感光层;以及可选地设置在基板和感光层之间的额外层。感光层或靠近基板的额外层包含(A)共聚物。共聚物(A)包括:(a1)公式(a1-1)的重复单元在侧链中,以及(a2)重复单元在侧链中至少具有公式(a2-1)到(a2-6)所表示的结构中的一个。公式(a1-1)中的L1、Z1、R1和R21、
R22和R23以及公式(a2-1)到(a2-6)中的变量如规范中所定义。