Photoresist Chemicals 2,7-Naphthalenedisulfonicacid, 3-hydroxy-4-[2-[4-(2-phenyldiazenyl)phenyl]diazenyl]-, sodium salt (1,CAS:6226-78-4 Cas：6226-78-4 Molecular Formula：C22H16 N4 O7 S2 . 2 Na