Cylindrical printing plate, cylindrical printing plate precursor, method for manufacturing cylindrical printing plate precursor, and method for manufacturing cylindrical printing plate

A cylindrical printing plate precursor comprising:

• a relief forming layer having a first hard layer, a soft layer, and a second hard layer in this order from a printing surface side,
• wherein a hardness K1 of the first hard layer is 10 MPa or more and less than 20 MPa,
• a ratio K1/K2 of the hardness K1 of the first hard layer with respect to a hardness K2 of the soft layer is 2.7 or more,
• a ratio K3/K2 of a hardness K3 of the second hard layer with respect to the hardness K2 of the soft layer is 1.2 or more,
• a thickness of the first hard layer is 0.05 mm or more and 0.3 mm or less, and
• a thickness of the soft layer is 0.3 mm or more and 2.0 mm or less.

A method for manufacturing a cylindrical printing plate precursor comprising:

• an uncured layer forming step of forming, on a peripheral surface of a cylindrical support, an uncured relief forming layer having a first uncured layer which becomes a first hard layer, a second uncured layer which becomes a soft layer, and a third uncured layer which becomes a second hard layer in this order from the cylindrical support;
• and
• a curing step of curing the formed first uncured layer, second uncured layer, and third uncured layer to form a relief forming layer having the first hard layer, the soft layer, and the second hard layer,
• wherein a hardness K1 of the first hard layer after curing is 10 MPa or more and less than 20 MPa,
• a ratio K1/K2 of the hardness K1 of the first hard layer with respect to a hardness K2 of the soft layer after curing is 2.7 or more,
• a ratio K3/K2 of a hardness K3 of the second hard layer with respect to the hardness K2 of the soft layer after curing is 1.2 or more,
• a thickness of the first hard layer after curing is 0.05 mm or more and 0.3 mm or less, and
• a thickness of the soft layer after curing is 0.3 mm or more and 2.0 mm or less.