Method for cleaning an ink holding material

摘要

Disclosed is an ink holding material to be put in an ink tank of an ink jet recording device, which is such that when it is extracted with pure water, the electrical conductivities and the surface tensions of the water before and after the extraction satisfy relationship (1): 350 >/= gamma r/ sigma r- gamma s/ sigma s>/=0(1) wherein gamma r represents the surface tension (mN/m) of pure water before extraction; sigma r represents the electrical conductivity (mS/m) of pure water before extraction; gamma s represents the surface tension (mN/m) of pure water after extraction; and sigma s represents the electrical conductivity (mS/m) of pure water after extraction.