Aqueous ink, ink cartridge, ink jet recording method, titanium oxide particle dispersion, method for producing titanium oxide particle dispersion and method for producing aqueous ink

A titanium oxide particle dispersion used in a production of an aqueous ink for ink jet recording, comprising:

• a titanium oxide particle;
• and
• a dispersant for the titanium oxide particle,
• wherein the titanium oxide particle contains titanium oxide, at least part of a surface of the titanium oxide is covered with alumina and silica,
• the dispersant for the titanium oxide particle comprises a compound represented by the following general formula (1),
• a proportion of the alumina in the titanium oxide particle is 0.50 times or more to 1.00 time or less a proportion of the silica in the titanium oxide particle in terms of a mass ratios, and
• a proportion of the titanium oxide in the titanium oxide particle is 90.0% by mass or more based on a total mass of the titanium oxide particle:
• where in general formula (1), R1, R2 and R5 are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, each R4 is independently an alkylene group having 2 to 4 carbon atoms, X is a single bond or an alkylene group having 1 to 6 carbon atoms, n is 6 to 24, a is 1 to 3, b is 0 to 2 and a+b=3.

A method for producing a titanium oxide particle dispersion used in a production of an aqueous ink for ink jet recording, comprising:

• providing a titanium oxide particle containing titanium oxide, at least part of a surface of the titanium oxide being covered with alumina and silica;
• and
• dispersing the titanium oxide particle in a liquid medium with a compound, represented by the following general formula (1), for dispersing the titanium oxide particle,
• wherein a proportion of the alumina in the titanium oxide particle is 0.50 times or more to 1.00 time or less a proportion of the silica in the titanium oxide particle in terms of a mass ratio, and
• a proportion of the titanium oxide in the titanium oxide particle is 90.0% by mass or more based on a total mass of the titanium oxide particle,
• where in general formula (1), R1, R2 and R5 are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, each R4 is independently an alkylene group having 2 to 4 carbon atoms, X is a single bond or an alkylene group having 1 to 6 carbon atoms, n is 6 to 24, a is 1 to 3, b is 0 to 2 and a+b=3.

An aqueous ink for ink jet recording, comprising:

• a titanium oxide particle;
• and
• a dispersant for the titanium oxide particle,
• wherein the titanium oxide particle contains titanium oxide, at least part of a surface of the titanium oxide is covered with alumina and silica,
• a proportion of an aluminum element in the titanium oxide particle is 0.57 times or more to 1.13 times or less a proportion of a silicon element in the titanium oxide particle in terms of a mass ratio, the proportions being obtained by inductively coupled plasma-optical emission spectrometry,
• a proportion of the titanium oxide in the titanium oxide particle is 90.0% by mass or more based on a total mass of the titanium oxide particle, and
• the dispersant for the titanium oxide particle comprises a compound represented by the following general formula (1):
• where in general formula (1), R1, R2 and R5 are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, each R4 is independently an alkylene group having 2 to 4 carbon atoms, X is a single bond or an alkylene group having 1 to 6 carbon atoms, n is 6 to 24, a is 1 to 3, b is 0 to 2 and a+b=3.