Patent ID: 6899751

Claim:
An ink for ink jet recording used for an ink jet printer in which at least a portion of a member being in contact with the ink is formed by any one of a borosilicate glass, a soda lime glass, a photosensitive glass, single crystal silicon, polysilicon, a silicon oxide film, a titanium nitride film, a zirconium film, a titanium oxide film, and a silicon nitride film, wherein the total of the content of alkali metals in the ink is 700 ppm or less, and 30% or more of a phosphonium ion represented by Formula 1 based on the equivalent of an anionic compound which is contained in the ink is contained: wherein Ra, Rb, Rc and Rd represent a linear, branched, or cyclic alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group, a halogenated alkyl group and a substituted or non-substituted phenyl group, and X − represents a counter ion.