Resin syringe, prefilled syringe, and method for producing resin syringe

A method for producing a resin syringe, the method comprising:

• a preparation step comprising:
• preparing a syringe body made of polyolefin, and
• preparing an ink comprising components including:
• 15 to 40% by mass of toluene,
• in addition to the toluene, a dissolving component for dissolving the polyolefin, the dissolving component comprising an aromatic hydrocarbon, the aromatic hydrocarbon having:
• a benzene ring structure, and
• a hydrocarbon side chain having two or more carbon atoms,
• chlorinated polypropylene having a degree of chlorination in a range of 15 to 30%,
• a colorant, and
• a filler;
• an application step comprising applying the ink to at least a part of an outer surface of the syringe body, such that at least a part of the outer surface of the syringe body is dissolved by the dissolving component to form a plurality of recessed portions in the outer surface, and each of the plurality of recessed portions is filled with at least one of the components of the ink;
• and
• a drying step comprising drying the applied ink to form a printing layer that comprises the components including the chlorinated polypropylene, the colorant, and the filler, on the outer surface of the syringe body.