Patent ID: 7886581

Claim:
A method for inspecting an oil-based ink composition for ink jet recording, which assesses whether or not an oil-based ink composition that is obtained by dispersing at least a pigment component represented by the following general formula (2) in a mixed solvent comprising 0.02 to 4 parts by mass of a lactone solvent per 1 part by mass of a polyalkylene glycol dialkyi ether represented by the following general formula (1) is suitable for ink jet recording, characterized in that said oil-based ink composition is assessed as applicable to ink jet recording when, in analyzing a measuring sample prepared by adding 2 ml of N-methyl-2-pyrrolidone and 8 ml of acetonitrile to 100 mg of said oil-based ink composition by means of high speed liquid chromatography under the following measuring conditions, the concentration of a component having a peak at a holding time of 10.3 minutes is 0.4 ppm or less: R 11 —(OR 13 ) n —OR 12 General Formula (1) where R 11 and R 12 that may be identical with or different from one another, are each an alkyl group having 1 to 3 carbon atoms, R 13 is an ethylene or propylene group, and n is an integer of 2 to 4; where R stands for a hydrogen atom, a methyl group or a chlorine atom; and Measuring Conditions for High Speed Liquid Chromatography an ODS column of 4.6 mm in inner diameter and 25 cm in length is used; water (liquid A)/acetonitrile (liquid B) is used as an eluting solution at a flow rate of 1.0 ml/min and at such a mixing ratio that there is linear gradient elution occurring, wherein the eluting solution flows at a constant 50% by volume/50% by volume (A/B) from the start of elution (0 minute) to the elapse of 1 minute, and at a rate varying from 50% by volume/50% by volume (A/B) to 0% by volume to 100% by volume (A/B) from the elapse of 1 minute after the start of elution to the elapse of 25 minutes; the column temperature is at 40° C.; and the detection wavelength is at 254 nm±4 nm.