INK COMPOSITION FOR HYDROUS CONTACT LENSES

摘要

The purpose of the present invention is to provide an ink composition for hydrous contact lenses, the ink composition being a composition that is discharged stably from the head of an inkjet printing apparatus when used for inkjet printing while effectively limiting the occurrence of clogging of the head due to drying of the ink composition and also being capable of effectively coloring intended areas of the lens and of effectively penetrating into the hydrous contact lens that is the object being colored. The ink composition for hydrous contact lenses is configured: so as to comprise a) a water-soluble organic solvent with a viscosity at 25°C of 10 cp or less and a boiling point of 100°C or higher, and b) a water-soluble organic thickener with a molecular weight of 1000 or less and a boiling point of 100°C or higher; and so that the weight loss rate LOD when heat treatment is performed at 60°C for 85 hours is 30% or less.