Brother Kogyo Kabushiki-kaisha

Tomoyo Hamajima

Narumi Koga

Narumi Kawai

Masaya Fujioka

Ryuji Kato

Kazuma Goto

Shunichi Higashiyama

Yasuhiro Taga

Noriatsu Aoi

Satoshi Okuda

Hideo Ohira

Junichiro Sugimoto

Masahiro Nishizaki

The present disclosure relates to ink-jet ink compositions, systems, and/or methods including a yellow ink, a magenta ink and a cyan ink for producing ink-jet printed matter having desirable color balance (e.g., difference in percent residual optical densities (ODs) between individual colors) and/or color retention (e.g., percent residual OD) following contact with water. For example, the absolute value of the difference in a percent residual OD of an image produced in accordance with some embodiments of the disclosure may be less than about 20%. The percent residual OD of an image produced in accordance with some embodiments of the disclosure may be more than about 40%.

Ink-jet ink set, producing method of ink-jet ink set, image forming method, and ink-jet recording apparatus

An ink set for ink-jet recording is provided defined by an evaluation indicator approximately corresponding to an evaluation sensed by human eyes without relying on a color difference (&#x394;E) or an optical density difference (&#x394;OD) at the time of evaluating long-term storage properties of the ink set for ink-jet recording. In the ink set for ink-jet recording which contains a yellow ink, a magenta ink and a cyan ink, values of hue angle change (&#x394;h), between before and after ozone resistance tests, of print regions corresponding to respective inks formed on glossy paper by using the yellow ink, the magenta ink and the cyan ink are not more than about 3&#xb0; for the yellow ink, not more than about 2&#xb0; for the magenta ink, and not more than about 6&#xb0; for the cyan ink.

Ink set for ink-jet recording, ink for ink-jet recording and method for forming image

An ink set for ink-jet recording is provided defined by an evaluation indicator approximately corresponding to an evaluation sensed by human eyes without relying on a color difference (&#x394;E) or an optical density difference (&#x394;OD) at the time of evaluating a long-term storage stability of the ink set for ink-jet recording. In the ink set for ink-jet recording which contains a yellow ink, a magenta ink and a cyan ink, values of hue angle change (&#x394;h), between before and after lightfastness tests, of print regions corresponding to respective inks formed on glossy paper by using the yellow ink, the magenta ink and the cyan ink are not more than about 3&#xb0; for the yellow ink, not more than about 2&#xb0; for the magenta ink, and not more than about 6&#xb0; for the cyan ink.

A magenta ink for ink-jet recording contains a coloring agent, water and a water soluble organic solvent. Different types of dyes are employed as the coloring agent. In particular, a dye (1) represented by the general formula (1) is used together with at least one dye selected from the group consisting of a dye (2) represented by the general formula (2) in a free acid form, C. I. Acid Red 289 and C. I. Acid Red 52. 

Magenta ink for ink-jet recording

An ink set for ink-jet recording is formed from a yellow ink in which C. I. Direct Yellow 132 and C. I. Direct Yellow 86 are employed, a magenta ink in which a specific pyrazolylazopyridine-based (or pyrazolylazopyrazine-based) dye and another specific dye are employed, and a cyan ink in which two specific types of copper phthalocyanine-based dyes are employed.

Ink set for ink-jet recording

A water-based ink set for ink-jet recording has a plurality of color inks. Each of at least one of the plurality of color inks contains a first ink and a second ink. The first ink has a first hue angle and the second ink has a second hue angle, wherein the first hue angle is not equal to the second hue angle and a differential range therebetween is a hue angle color range of a normal color of the at least one of the plurality of color inks; and a coloring agent of one of the first ink and the second ink is a pigment and a coloring agent of the other thereof is a dye.

Water-based ink set for ink-jet recording

The water-based ink set for ink-jet recording includes a magenta ink and a red ink with dynamic surface tensions thereof satisfying the following inequalities (I), (II), (III) and (IV)&#x3c3;&#x2266;about 49 mN/m&#x2003;&#x2003;(I)&#x3c3;+&#x3c3;&#x2266;about 100 mN/m&#x2003;&#x2003;(II)wherein &#x3c3;is the dynamic surface tension of the magenta ink at a lifetime of 30 ms and &#x3c3;is the dynamic surface tension of the red ink at a lifetime of 30 ms,&#x3c3;&#x2267;about 36 mN/m&#x2003;&#x2003;(III)&#x3c3;+&#x3c3;&#x2267;about 70 mN/m&#x2003;&#x2003;(IV)wherein &#x3c3;is the dynamic surface tension of the magenta ink at a lifetime of 1,000 ms and &#x3c3;is the dynamic surface tension of the red ink at a lifetime of 1,000 ms).

Water-based ink set for ink-jet recording and ink-jet recording method

The water-based ink set for ink-jet recording includes a cyan ink and a blue ink with dynamic surface tensions thereof satisfying the following inequalities (I), (II), (III) and (IV)&#x3c3;&#x2266;about 49 mN/m&#x2003;&#x2003;(I)&#x3c3;+&#x3c3;&#x2266;about 100 mN/m&#x2003;&#x2003;(II)wherein &#x3c3;is the dynamic surface tension of the cyan ink at a lifetime of 30 ms and &#x3c3;is the dynamic surface tension of the blue ink at a lifetime of 30 ms,&#x3c3;&#x2267;about 36 mN/m&#x2003;&#x2003;(III)&#x3c3;+&#x3c3;&#x2267;about 70 mN/m&#x2003;&#x2003;(IV)wherein &#x3c3;is the dynamic surface tension of the cyan ink at a lifetime of 1,000 ms and &#x3c3;is the dynamic surface tension of the blue ink at a lifetime of 1,000 ms.

A cyan ink for ink-jet recording contains a coloring agent, water and a water soluble organic solvent. Different types of dyes are employed as the coloring agent. In particular, a dye represented by the general formula (1) is used together with at least one dye selected from the group consisting of a dye represented by the general formula (2), a dye represented by the general formula (3) and C. I. Direct Blue 86. In the formulas, Pc(Cu) is a copper phthalocyanine nucleus. 

Cyan ink for ink-jet recording

A water-based ink set for ink-jet recording is provided. According to this ink set, graininess in a low density printed part can be reduced without reducing a color reproduction range in red and magenta directions in a high density printed part. In addition, the color reproduction range in the red direction can be extended to improve the vividness of red color. The water-based ink set for ink-jet recording includes a magenta ink and a red ink. The magenta ink is a light magenta ink having a lightness (L*) of about 50 or more in the L*a*b* colorimetric system. Preferably, the ink set further includes a light cyan ink having a lightness (L*) of about 60 or more and a blue ink and/or a green ink.

The water-based ink set for ink-jet recording includes a cyan ink and a blue ink, or a cyan ink and a green ink. The cyan ink is a light cyan ink having a lightness (L*) of about 60 or more in the L*a*b* colorimetric system. A normal cyan ink having a lightness (L*) of about 60 or less in the L*a*b* calorimetric system is not included in the ink set.

A water-based ink set for ink-jet recording is provided which is capable of: reducing graininess in a low-density printed part without reducing the color reproduction range in red and magenta directions in a high-density printed part; extending the color reproduction range in the red direction; improving the vividness of the red color; and improving the light fastness and gas resistance. The water-based ink set for ink-jet recording includes a magenta dye ink and a red pigment ink. The magenta dye ink is a light magenta dye ink having a lightness (L*) of about 50 or more in the L*a*b* calorimetric system.

A water-based ink set for ink-jet recording is provided which is capable of: reducing graininess in a low-density printed part in a cyan direction without reducing the color reproduction range in the cyan direction in a high-density printed part; extending the color reproduction range in a blue direction and/or a green direction; and improving gas resistance and the vividness in the blue direction and/or the green direction. The water-based ink set for ink-jet recording includes a cyan dye ink employing dye as a coloring agent and a blue pigment ink employing pigment as a coloring agent and/or a green pigment ink employing pigment as a coloring agent. The cyan dye ink is a light cyan dye ink having a lightness (L*) of about 60 or more in the L*a*b* colorimetric system.

A water-based ink set for ink-jet recording is provided which is capable of: reducing graininess in a low-density printed part without reducing the color reproduction range in red and magenta directions in a high-density printed part; extending the color reproduction range in the red direction; improving the vividness of the red color; and improving the light fastness and gas resistance. The water-based ink set for ink-jet recording includes a magenta pigment ink and a red dye ink. The magenta pigment ink is a light magenta pigment ink having a lightness (L*) of about 50 or more in the L*a*b* colorimetric system.

A water-based ink set for ink-jet recording is provided which is capable of: reducing graininess in a low-density printed part in a cyan direction without reducing the color reproduction range in the cyan direction in a high-density printed part; extending the color reproduction range in a blue direction and/or a green direction; improving the vividness of the blue color and/or the green color; and improving gas resistance in a printed part in the cyan direction. The water-based ink set for ink-jet recording includes a cyan pigment ink employing pigment as a coloring agent and a blue dye ink employing dye as a coloring agent and/or a green dye ink employing dye as a coloring agent. The cyan pigment ink is a light cyan pigment ink having a lightness (L*) of about 60 or more in the L*a*b* colorimetric system.

Growing community of inventors

Nagoya, Japan

Tomoyo Hamajima