Quinacridone pigments that are surface-functionalized with glycidyl methacrylate, maleic anhydride, or 4-methacryloxyethyl trimellitic anhydride to create a functionalized pigment. The functional groups are then activated to bond hydrophobic polymers, thereby coating the pigment with the hydrophobic polymers. The quinacridone pigments can be used for a variety of applications. They are well-suited for use in electro-optic materials, such as electrophoretic media for use in electrophoretic displays.

Quinacridone pigments that are surface-functionalized with glycidyl methacrylate, maleic anhydride, or 4-methacryloxyethyl trimellitic anhydride to create a functionalized pigment. The functional groups are then activated to bond hydrophobic polymers, thereby coating the pigment with the hydrophobic polymers. The quinacridone pigments can be used for a variety of applications. They are well-suited for use in electro-optic materials, such as electrophoretic media for use in electrophoretic displays.

An example of an inkjet ink composition includes a pigment, a dispersion synergist, a metal oxide, a polar solvent and water. The pigment is selected from the group consisting of a quinacridone and a phthalocyanine. The dispersion synergist has a structure of the pigment substituted with at least one solubilizing moiety selected from the group consisting of an ionic moiety, a non-ionic moiety, and a combination thereof.

An example of an inkjet ink composition includes a pigment, a dispersion synergist, a metal oxide, a polar solvent and water. The pigment is selected from the group consisting of a quinacridone and a phthalocyanine. The dispersion synergist has a structure of the pigment substituted with at least one solubilizing moiety selected from the group consisting of an ionic moiety, a non-ionic moiety, and a combination thereof.

There is provided a photoelectric conversion film including a quinacridone derivative represented by the following General formula and a subphthalocyanine derivative represented by the following General formula.

There is provided a photoelectric conversion film including a quinacridone derivative represented by the following General formula and a subphthalocyanine derivative represented by the following General formula.

A black inkjet ink composition includes a carbon black pigment; a dispersion synergist having an aromatic structure substituted with at least one solubilizing moiety selected from the group consisting of an ionic moiety, a non-ionic moiety, and a combination thereof; a polar solvent; and water. A method for making the black inkjet ink composition and a printing method using the same is also disclosed.

An object to be achieved by the present, invention is to provide a quinacridone pigment having hue that is yellowish and clear and having excellent storage stability, wherein the quinacridone pigment can be advantageously used in an ink-jet ink and the like. Provided is a quinacridone solid solution pigment comprising at least C. I. Pigment Violet 19 and C. I. Pigment Red 122, wherein the ratio of a diffraction peak intensity at a diffraction angle 2 of 14.80.2 to a diffraction peak intensity at a diffraction angle 2 of 11.90.2 is 1.20 or less, as measured by X-ray diffractometry with respect to the quinacridone solid solution pigment.

An object to be achieved by the present, invention is to provide a quinacridone pigment having hue that is yellowish and clear and having excellent storage stability, wherein the quinacridone pigment can be advantageously used in an ink-jet ink and the like. Provided is a quinacridone solid solution pigment comprising at least C. I. Pigment Violet 19 and C. I. Pigment Red 122, wherein the ratio of a diffraction peak intensity at a diffraction angle 2 of 14.80.2 to a diffraction peak intensity at a diffraction angle 2 of 11.90.2 is 1.20 or less, as measured by X-ray diffractometry with respect to the quinacridone solid solution pigment.

A technical problem of the present invention is to provide a condensed polycyclic organic pigment having excellent dispersion properties and dispersion stability. More specifically, the technical problem of the present invention is to provide a condensed polycyclic organic pigment in which a practically sufficient viscosity is achieved in terms of both the initial viscosity of a base ink and the viscosity over time of a base ink when used in the printing ink application. As a result of thorough studies on the surface state of organic pigment particles and interaction among components constituting a printing ink, it has been found that the technical problem can be solved by using a polyvalent metal inorganic salt in a condensed polycyclic organic pigment, thus accomplishing the present invention.