Method for producing printing plate, reusing method for printing plate, and printing machine

A method for making a reusable printing plate in which a hydrophobic image area is formed on at least a part of a hydrophilic surface containing a photocatalyst of the printing plate, comprising the steps of:

• carrying out a hydrophobic agent application process in which a solution, containing an organic compound having a property of reacting with or being fixed to the surface of said printing plate by a heating process and a property of being decomposed by the action of said photocatalyst when irradiated by light having a higher energy than a band gap energy of said photocatalyst, is applied as a hydrophobic agent on the surface of said printing plate;
• carrying out an image area formation process in which at least a part of the surface of said printing plate is subjected to a heating process to form said hydrophobic image area on at least part of said hydrophilic surface;
• and
• carrying out a non-image area formation process in which said organic compound applied to an area other than said hydrophobic image area on the surface of said printing plate is removed.