Ink Composition for High-Quality/High-Definition Screen Printing, Printed Matter Produced by the Screen Printing Ink Composition, and Method for Producing the Printed Matter

An ink composition for high-quality/high-definition screen printing, comprising:

• an ink composition having a measured flow radius value of 14.0 to 19.0 mm after 1 minute from a start of measurement by a flow property measuring method using a spread meter at 25° C. according to JIS K5701-1:2000, and wherein the ink composition satisfies “F60”-“F45”≦1.0 mm, where “F60” is defined as the measured flow radius value after 1 minute and “F45” is defined as the measured flow radius value after 45 seconds from the start of measurement by a flow property measuring method using the spread meter,
• the ink composition is one that, when producing printed matter by screen printing onto an object to be printed using a 360-mesh screen printing plate formed by a high-strength, non-deforming stainless steel mesh with a filament diameter of 25 μm, produces printed matter with a printed image edge spreading width of no more than 10 μm from image design dimensions of the printing plate,
• the ink composition including a solvent with a boiling point of at least 170° C. at a wt % of at least 70 wt % of a total of the solvent, and one of a prepolymer and polymer with a weight-average molecular weight of at least 2000 at a wt % of at least 2 wt % with respect to a total of the ink composition, and
• having a viscosity of 30 to 180 Pa·s as measured with a BH-type rotating viscosimeter at 25° C., and a thixotropic index (TI) of 2.0 to 8.0.