Method for producing package including hydrogen sulfide sustained release agent, hydrogen sulfide sustained release agent, hydrogen sulfide sustained release composite, and method for generating hydrogen sulfide using same

A method for producing a package comprising a layered double hydroxide having HS− and/or Sk2− (wherein k represents a positive integer) intercalated among layers, and a packaging material hermetically housing the layered double hydroxide, the method comprising:

• preparing a layered double hydroxide having an anion other than HS− and/or Sk2− (wherein k represents a positive integer) intercalated among layers, and a solvent;
• making the solvent to contain HS− and/or Sk2− under a nitrogen gas or rare gas atmosphere to provide a solution;
• bringing the layered double hydroxide having an anion other than HS− and/or Sk2− (wherein k represents a positive integer) intercalated among layers into contact with the solution under a nitrogen gas or rare gas atmosphere;
• separating a solid matter after the contact from the solution, and washing and drying the solid matter, under a nitrogen gas or rare gas atmosphere;
• and
• sealing the solid matter after drying in a packaging material.