JP2016216616A - Ink composition for inkjet recording and ink set - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink composition for inkjet recording, which achieves excellent image fastness and color developing property of a recorded matter to be obtained and has excellent initial filling property and continuous printing stability, and an ink set.SOLUTION: The ink composition of the present invention contains, as dyes, a first dye represented by formula (Bk-1) and a black second dye except for the first dye, in which a composition ratio of the first dye to the second dye is 8:2 or more and 9:1 or less and the total addition amount of the first dye and the second dye is 3.0 wt.% or more and 5.0 wt.% or less. The ink composition comprises an alkylene oxide adduct of acetylene glycol having 12 or more carbon atoms in the main chain, acetylene glycol having 10 or more carbon atoms in the main chain, and a polyoxyalkylene alkylether.SELECTED DRAWING: None

Description

  The present invention relates to an ink composition for ink jet recording and an ink set.

  The ink jet recording method is capable of recording high-definition images by supplying ink to a print head, ejecting ink droplets from the print head, and depositing the ink on a recording medium such as paper. Has made great progress. Among them, various studies have been made on improving the obtained image.

  For example, Patent Document 1 discloses at least two types of ink compositions for the purpose of providing an ink composition that can improve fastness such as light resistance and ozone resistance of an obtained image and can exhibit a desired hue. A black aqueous ink composition is disclosed that combines these dyes.

  In addition, for example, in Patent Document 2, in a printing method using an inkjet recording method, bubbles generated in ink are removed by a deaeration device or the like to eliminate defective ink discharge, thereby causing image defects and ink defects. A technique for improving the decrease in concentration is disclosed.

JP2013-253221A JP 2011-42104 A

  However, further improvement in image fastness and color developability of the obtained recorded matter is desired. In addition, even if the ink is degassed, it is difficult to maintain the degassed state of the ink because minute bubbles are likely to be mixed due to gas-liquid exchange accompanying ink consumption or ink consumption. Sex is inadequate.

  Some embodiments according to the present invention solve at least a part of the above-described problems, whereby the obtained recorded matter has excellent image fastness and color developability, and further has excellent initial filling property and continuous printing stability. An object is to provide a recording ink composition and an ink set.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

（式（Ｂｋ−１）中、Ｒ^１、Ｒ^２、Ｒ^５、Ｒ^６及びＲ^７は各々独立して水素原子、ハロゲン原子、シアノ基、ヒドロキシル基、カルボキシル基、スルホ基、スルファモイル基、Ｎ−アルキルアミノスルホニル基、Ｎ−フェニルアミノスルホニル基、ヒドロキシル基で置換されてもよい炭素数１以上４以下のアルキルスルホニル基、ホスホ基、ニトロ基、アシル基、ウレイド基、炭素数１以上４以下のアルキル基（ヒドロキシル基又は炭素数１以上４以下のアルコキシ基で置換されていてもよい）、炭素数１以上４以下のアルコキシ基（アルキル基はヒドロキシル基、炭素数１以上４以下のアルコキシ基、スルホ基又はカルボキシル基で置換されていてもよい）、アシルアミノ基、アルキルスルホニルアミノ基又はフェニルスルホニルアミノ基（フェニル基はハロゲン原子、アルキル基又はニトロ基で置換されていてもよい）を、Ｒ^３及びＲ^４は各々独立して水素原子、ハロゲン原子、シアノ基、カルボキシル基、スルホ基、ニトロ基、炭素数１以上４以下のアルキル基（ヒドロキシル基又は炭素数１以上４以下のアルコキシ基で置換されていてもよい）、炭素数１以上４以下のアルコキシ基（アルキル基はヒドロキシル基、炭素数１以上４以下のアルコキシ基、スルホ基又はカルボキシル基で置換されていてもよい）、アシルアミノ基、アルキルスルホニルアミノ基又はフェニルスルホニルアミノ基（フェニル基はハロゲン原子、アルキル基又はニトロ基で置換されてもよい）を、ｎは０又は１をそれぞれ表す。） [Application Example 1]
One aspect of the ink composition for inkjet recording according to the present invention is:
As the dye, including a first dye represented by the following general formula (Bk-1), and a black second dye other than the first dye,
The composition ratio of the first dye and the second dye is 8: 2 to 9: 1;
The total addition amount of the first dye and the second dye is 3.0% by mass or more and 5.0% by mass or less,
It contains an alkylene oxide adduct of acetylene glycol having a main chain having 12 or more carbon atoms, an acetylene glycol having 10 or more carbon atoms in the main chain, and a polyoxyalkylene alkyl ether.

(In formula (Bk-1), R ¹ , R ² , R ⁵ , R ⁶ and R ⁷ are each independently a hydrogen atom, halogen atom, cyano group, hydroxyl group, carboxyl group, sulfo group, sulfamoyl group, N -Alkylaminosulfonyl group, N-phenylaminosulfonyl group, alkylsulfonyl group having 1 to 4 carbon atoms which may be substituted with hydroxyl group, phospho group, nitro group, acyl group, ureido group, 1 to 4 carbon atoms An alkyl group (which may be substituted with a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms), an alkoxy group having 1 to 4 carbon atoms (the alkyl group is a hydroxyl group, an alkoxy group having 1 to 4 carbon atoms) Which may be substituted with a sulfo group or a carboxyl group), an acylamino group, an alkylsulfonylamino group, or a phenylsulfonyl group. Amino group (the phenyl group a halogen atom, an alkyl group or may be substituted by nitro group) to, R ³ and R ⁴ are each independently hydrogen atom, a halogen atom, a cyano group, a carboxyl group, a sulfo group, a nitro Group, an alkyl group having 1 to 4 carbon atoms (which may be substituted with a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms), an alkoxy group having 1 to 4 carbon atoms (an alkyl group is a hydroxyl group, a carbon atom) 1 to 4 or less alkoxy groups, which may be substituted with an alkoxy group, a sulfo group or a carboxyl group), an acylamino group, an alkylsulfonylamino group or a phenylsulfonylamino group (the phenyl group is substituted with a halogen atom, an alkyl group or a nitro group) And n represents 0 or 1 respectively.)

  According to the ink composition for ink-jet recording of Application Example 1, to provide an ink composition for ink-jet recording excellent in image fastness and color developability of the obtained recorded matter, and further excellent in initial filling property and continuous printing stability. Can do.

[Application Example 2]
In the inkjet recording ink composition of Application Example 1,
The amount of the second dye added may be 0.1% by mass or more and 2.0% by mass or less.

（上記式（Ｉ）中、Ｍは各々独立して水素原子またはアルカリ金属である）

（上記式（ＩＩ）中、Ｍは各々独立して水素原子またはアルカリ金属である）

（上記式（ＩＩＩ）中、Ｍは各々独立して水素原子またはアルカリ金属である）

（上記式（ＩＶ）中、Ｍは水素原子、アルカリ金属、アンモニア、および有機アミン類からなる群から選択される基の陽イオンを表し、ｍは１または２を表し、ｎは０または１を表す。） [Application Example 3]
In the ink composition for ink jet recording of Application Example 1 or Application Example 2,
The second dye is C.I. I. Direct black 154, C.I. I. Direct black 168, C.I. I. Acid Black 52, C.I. I. Reactive Black 39, C.I. I. It can be at least one selected from the group consisting of food black 2 and compounds represented by the following general formulas (I) to (IV).

(In the above formula (I), each M is independently a hydrogen atom or an alkali metal)

(In the above formula (II), each M is independently a hydrogen atom or an alkali metal)

(In the above formula (III), each M is independently a hydrogen atom or an alkali metal)

(In the above formula (IV), M represents a cation of a group selected from the group consisting of a hydrogen atom, an alkali metal, ammonia, and organic amines, m represents 1 or 2, and n represents 0 or 1) Represents.)

（式（Ｂｗ−１）中、Ｒ^２１、Ｒ^２２、Ｒ^２３、Ｒ^２４、Ｒ^２５、Ｒ^２６、Ｒ^２７及びＲ^２８は、各々独立して、水素原子；ハロゲン原子；スルホ基；カルボキシ基；スルファモイル基；カルバモイル基；炭素数１以上４以下のアルキル基；炭素数１以上４以下のアル
コキシ基；置換基として、ヒドロキシ基、炭素数１以上４以下のアルコキシ基、ヒドロキシ−炭素数１以上４以下のアルコキシ基、スルホ基、及びカルボキシ基よりなる群から選択される少なくとも１種類の基で置換された炭素数１以上４以下のアルコキシ基；炭素数１以上４以下のアルキルカルボニルアミノ基；カルボキシ基で置換された炭素数１以上４以下のアルキルカルボニルアミノ基；ウレイド基；モノ炭素数１以上４以下のアルキルウレイド基；ジ炭素数１以上４以下のアルキルウレイド基；置換基として、ヒドロキシ基、スルホ基、及びカルボキシ基よりなる群から選択される少なくとも１種類の基で置換されたモノ炭素数１以上４以下のアルキルウレイド基；置換基として、ヒドロキシ基、スルホ基、及びカルボキシ基よりなる群から選択される少なくとも１種類の基で置換されたジ炭素数１以上４以下のアルキルウレイド基；ベンゾイルアミノ基；ベンゼン環が、ハロゲン原子、炭素数１以上４以下のアルキル基、ニトロ基、スルホ基、及びカルボキシ基よりなる群から選択される少なくとも１種類の基で置換されたベンゾイルアミノ基；ベンゼンスルホニルアミノ基；又は、ベンゼン環が、ハロゲン原子、炭素数１以上４以下のアルキル基、ニトロ基、スルホ基、及びカルボキシ基よりなる群から選択される少なくとも１種類の基で置換されたフェニルスルホニルアミノ基；を表し、
Ｘは、２価の架橋基を表す。） [Application Example 4]
In the ink composition for inkjet recording according to any one of Application Examples 1 to 3,
Furthermore, a third dye represented by the following general formula (Bw-1) is included,
The amount of the third dye added may be 0.5% by mass or more and 1.5% by mass or less.

(In the formula (Bw-1), R ²¹ , R ²² , R ²³ , R ²⁴ , R ²⁵ , R ²⁶ , R ²⁷ and R ²⁸ are each independently a hydrogen atom; a halogen atom; a sulfo group; a carboxy group. A sulfamoyl group, a carbamoyl group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a hydroxy group, an alkoxy group having 1 to 4 carbon atoms, and a hydroxy-carbon number of 1 or more. An alkoxy group having 1 to 4 carbon atoms substituted with at least one group selected from the group consisting of an alkoxy group having 4 or less alkoxy groups, a sulfo group, and a carboxy group; an alkylcarbonylamino group having 1 to 4 carbon atoms; An alkylcarbonylamino group having 1 to 4 carbon atoms substituted with a carboxy group; a ureido group; an alkylureido group having 1 to 4 monocarbons; a dicarbon An alkylureido group having 1 or more and 4 or less; an alkylureido group having 1 to 4 monocarbons substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group, and a carboxy group as a substituent; As a substituent, an alkylureido group having 1 to 4 dicarbon atoms substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group, and a carboxy group; a benzoylamino group; A benzoylamino group substituted with at least one group selected from the group consisting of an atom, an alkyl group having 1 to 4 carbon atoms, a nitro group, a sulfo group, and a carboxy group; a benzenesulfonylamino group; or a benzene ring From a halogen atom, an alkyl group having 1 to 4 carbon atoms, a nitro group, a sulfo group, and a carboxy group A phenylsulfonylamino group substituted with at least one group selected from the group consisting of:
X represents a divalent crosslinking group. )

[Application Example 5]
In the ink composition for inkjet recording according to any one of Application Examples 1 to 4,
In addition, triethylene glycol monobutyl ether as a solvent,
The addition amount of the triethylene glycol monobutyl ether may be at least twice the addition amount of the polyoxyalkylene alkyl ether.

[Application Example 6]
In the ink composition of any one of Application Examples 1 to 5,
The dynamic contact angle with respect to the silicon wafer can be 22 ° or less at 100 msec after dropping and 7 ° or less at 5100 msec after dropping.

[Application Example 7]
One aspect of the ink set according to the present invention is:
The ink composition for ink jet recording according to any one of Application Examples 1 to 6 is provided.

  Several embodiments of the present invention will be described below. Embodiment described below demonstrates an example of this invention. The present invention is not limited to the following embodiments, and includes various modified embodiments that are implemented within a range that does not change the gist of the present invention. Note that not all of the configurations described below are essential configurations of the present invention.

（式（Ｂｋ−１）中、Ｒ^１、Ｒ^２、Ｒ^５、Ｒ^６及びＲ^７は各々独立して水素原子、ハロゲン原子、シアノ基、ヒドロキシル基、カルボキシル基、スルホ基、スルファモイル基、Ｎ−アルキルアミノスルホニル基、Ｎ−フェニルアミノスルホニル基、ヒドロキシル基で置換されてもよい炭素数１以上４以下のアルキルスルホニル基、ホスホ基、ニトロ基、アシル基、ウレイド基、炭素数１以上４以下のアルキル基（ヒドロキシル基又は炭素数１以上４以下のアルコキシ基で置換されていてもよい）、炭素数１以上４以下のアルコキシ基（アルキル基はヒドロキシル基、炭素数１以上４以下のアルコキシ基、スルホ基又はカルボキシル基で置換されていてもよい）、アシルアミノ基、アルキルスルホニルアミノ基又はフェニルスルホニルアミノ基（フェニル基はハロゲン原子、アルキル基又はニトロ基で置換されていてもよい）を、Ｒ^３及びＲ^４は各々独立して水素原子、ハロゲン原子、シアノ基、カルボキシル基、スルホ基、ニトロ基、炭素数１以上４以下のアルキル基（ヒドロキシル基又は炭素数１以上４以下のアルコキシ基で置換されていてもよい）、炭素数１以上４以下のアルコキシ基（アルキル基はヒドロキシル基、炭素数１以上４以下のアルコキシ基、スルホ基又はカルボキシル基で置換されていてもよい）、アシルアミノ基、アルキルスルホニルアミノ基又はフェニルスルホニルアミノ基（フェニル基はハロゲン原子、アルキル基又はニトロ基で置換されてもよい）を、ｎは０又は１をそれぞれ表す。） 1. Ink composition for ink jet recording The ink composition for ink jet recording of the present embodiment (hereinafter also simply referred to as “ink composition”) is a first dye represented by the following general formula (Bk-1) as a dye. And a black second dye other than the first dye, the composition ratio of the first dye and the second dye is 8: 2 to 9: 1, and the first dye and the second dye The total addition amount of the dye is 3.0 mass% or more and 5.0 mass% or less, and the alkylene oxide adduct of acetylene glycol having 12 or more carbon atoms in the main chain and the main chain having 10 or more carbon atoms. It contains a certain acetylene glycol and a polyoxyalkylene alkyl ether. Hereinafter, each component contained in the ink composition according to the present embodiment will be described.

(In formula (Bk-1), R ¹ , R ² , R ⁵ , R ⁶ and R ⁷ are each independently a hydrogen atom, halogen atom, cyano group, hydroxyl group, carboxyl group, sulfo group, sulfamoyl group, N -Alkylaminosulfonyl group, N-phenylaminosulfonyl group, alkylsulfonyl group having 1 to 4 carbon atoms which may be substituted with hydroxyl group, phospho group, nitro group, acyl group, ureido group, 1 to 4 carbon atoms An alkyl group (which may be substituted with a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms), an alkoxy group having 1 to 4 carbon atoms (the alkyl group is a hydroxyl group, an alkoxy group having 1 to 4 carbon atoms) Which may be substituted with a sulfo group or a carboxyl group), an acylamino group, an alkylsulfonylamino group, or a phenylsulfonyl group. Amino group (the phenyl group a halogen atom, an alkyl group or may be substituted by nitro group) to, R ³ and R ⁴ are each independently hydrogen atom, a halogen atom, a cyano group, a carboxyl group, a sulfo group, a nitro Group, an alkyl group having 1 to 4 carbon atoms (which may be substituted with a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms), an alkoxy group having 1 to 4 carbon atoms (an alkyl group is a hydroxyl group, a carbon atom) 1 to 4 or less alkoxy groups, which may be substituted with an alkoxy group, a sulfo group or a carboxyl group), an acylamino group, an alkylsulfonylamino group or a phenylsulfonylamino group (the phenyl group is substituted with a halogen atom, an alkyl group or a nitro group) And n represents 0 or 1 respectively.)

（式（Ｂｋ−１）中、Ｒ^１、Ｒ^２、Ｒ^５、Ｒ^６及びＲ^７は各々独立して水素原子、ハロゲン原子、シアノ基、ヒドロキシル基、カルボキシル基、スルホ基、スルファモイル基、Ｎ−アルキルアミノスルホニル基、Ｎ−フェニルアミノスルホニル基、ヒドロキシル基で置換されてもよい炭素数１以上４以下のアルキルスルホニル基、ホスホ基、ニトロ基、アシル基、ウレイド基、炭素数１以上４以下のアルキル基（ヒドロキシル基又は炭素数１以上４以下のアルコキシ基で置換されていてもよい）、炭素数１以上４以下のアルコキシ基（アルキル基はヒドロキシル基、炭素数１以上４以下のアルコキシ基、スルホ基又はカルボキシル基で置換されていてもよい）、アシルアミノ基、アルキルスルホニルアミノ基又はフェニルスルホニルアミノ基（フェニル基はハロゲン原子、アルキル基又はニトロ基で置換されていてもよい）を、Ｒ^３及びＲ^４は各々独立して水素原子、ハロゲン原子、シアノ基、カルボキシル基、スルホ基、ニトロ基、炭素数１以上４以下のアルキル基（ヒドロキシル基又は炭素数１以上４以下のアルコキシ基で置換されていてもよい）、炭素数１以上４以下のアルコキシ基（アルキル基はヒドロキシル基、炭素数１以上４以下のアルコキシ基、スルホ基又はカルボキシル基で置換されていてもよい）、アシルアミノ基、アルキルスルホニルアミノ基又はフェニルスルホニルアミノ基（フェニル基はハロゲン原子、アル
キル基又はニトロ基で置換されてもよい）を、ｎは０又は１をそれぞれ表す。） 1.1. First Dye Represented by Formula (Bk-1) The ink according to the present embodiment includes a first dye represented by the following general formula (Bk-1) as a dye. Hereinafter, the first dye (azo compound or salt thereof) represented by the formula (Bk-1) will be described in detail.

(In formula (Bk-1), R ¹ , R ² , R ⁵ , R ⁶ and R ⁷ are each independently a hydrogen atom, halogen atom, cyano group, hydroxyl group, carboxyl group, sulfo group, sulfamoyl group, N -Alkylaminosulfonyl group, N-phenylaminosulfonyl group, alkylsulfonyl group having 1 to 4 carbon atoms which may be substituted with hydroxyl group, phospho group, nitro group, acyl group, ureido group, 1 to 4 carbon atoms An alkyl group (which may be substituted with a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms), an alkoxy group having 1 to 4 carbon atoms (the alkyl group is a hydroxyl group, an alkoxy group having 1 to 4 carbon atoms) Which may be substituted with a sulfo group or a carboxyl group), an acylamino group, an alkylsulfonylamino group, or a phenylsulfonyl group. Amino group (the phenyl group a halogen atom, an alkyl group or may be substituted by nitro group) to, R ³ and R ⁴ are each independently hydrogen atom, a halogen atom, a cyano group, a carboxyl group, a sulfo group, a nitro Group, an alkyl group having 1 to 4 carbon atoms (which may be substituted with a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms), an alkoxy group having 1 to 4 carbon atoms (an alkyl group is a hydroxyl group, a carbon atom) 1 to 4 or less alkoxy groups, which may be substituted with an alkoxy group, a sulfo group or a carboxyl group), an acylamino group, an alkylsulfonylamino group or a phenylsulfonylamino group (the phenyl group is substituted with a halogen atom, an alkyl group or a nitro group) And n represents 0 or 1 respectively.)

  In the ink composition according to the present embodiment, the first dye represented by the formula (Bk-1) is a dye that functions as a coloring material for the ink, and is used in combination with a second dye described later. By adjusting the content in the ink and the content ratio of these dyes, it is possible to improve the image fastness and color developability of the obtained recorded matter. That is, an image recorded using the ink according to the present embodiment has excellent gas resistance and light resistance due to the complementary action of the first dye and the second dye, and exhibits an excellent black hue. It will be a thing. In the present specification, excellent black means that at least one of the a * value and the b * value of the image is 20 or less. The a * value and the b * value are defined by the CIE (International Commission on Illumination) as an L * a * b * color system. It is more preferable that the a * value and b * value of the image are both within 10.

  In formula (Bk-1), the number of carbon atoms in the alkyl group, alkoxy group, acyl group, etc., which is not particularly described, is not particularly limited, but is usually about 1 to 20 carbon atoms, preferably carbon number 1 to 10 or less, and more preferably an alkyl group, an alkoxy group or an aliphatic acyl group having 1 to 4 carbon atoms, and an aromatic acyl group having 7 to 11 carbon atoms. Yes, specific examples include a benzoyl group and a naphthoyl group.

In the formula (Bk-1), as R ¹ , R ² , R ⁵ , R ⁶ and R ⁷ , examples of the N-alkylaminosulfonyl group include, for example, an N-methylaminosulfonyl group, an N-ethylaminosulfonyl group, N- (n-butyl) aminosulfonyl group, N, N-dimethylaminosulfonyl group, N, N-di (n-propyl) aminosulfonyl group and the like can be mentioned.

Examples of the alkylsulfonyl group having 1 to 4 carbon atoms that may be substituted with a hydroxyl group in R ¹ , R ² , R ⁵ , R ⁶ and R ⁷ in the formula (Bk-1) include, for example, methylsulfonyl , Ethylsulfonyl, propylsulfonyl, butylsulfonyl, hydroxyethylsulfonyl, 2-hydroxypropylsulfonyl and the like.

In the formula (Bk-1), as R ¹ , R ² , R ⁵ , R ⁶ and R ⁷ , preferred examples of the acyl group include alkyl having 1 to 4 carbon atoms such as acetyl, propionyl, butyryl or isobutyryl. Examples thereof include carbonyl, aromatic carbonyl having 7 to 11 carbon atoms, such as benzoyl and naphthoyl.

Examples of the alkyl group having 1 to 4 carbon atoms that may be substituted with a hydroxy group or an alkoxy group having 1 to 4 carbon atoms in R ¹ to R ⁷ in the formula (Bk-1) include, for example, methyl, Ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, methoxyethyl, 2-ethoxyethyl, n-propoxyethyl, Examples include isopropoxyethyl, n-butoxyethyl, methoxypropyl, ethoxypropyl, n-propoxypropyl, isopropoxybutyl, n-propoxybutyl and the like.

In formula (Bk-1), R ¹ to R ⁷ may be substituted with a substituent selected from the group consisting of a hydroxy group, an alkoxy group having 1 to 4 carbon atoms, a sulfo group, or a carboxyl group. Examples of the alkoxy group of 4 or less include, for example, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, 2-hydroxyethoxy, 2-hydroxypropoxy, 3-hydroxypropoxy, Methoxyethoxy, ethoxyethoxy, n-propoxyethoxy, isopropoxyethoxy, n-butoxyethoxy, methoxypropoxy, ethoxypropoxy, n-propoxypropoxy, isopropoxybutoxy, n-propoxybutoxy, 2-hydroxyethoxyethoxy, carboxymethoxy, - carboxyethoxy, 3-carboxypropoxy, 3
Examples include sulfopropoxy and 4-sulfobutoxy.

In formula (Bk-1), in R ¹ to R ⁷ , preferred acyl groups of the acylamino group include, for example, preferred acyl groups mentioned in the above-mentioned acyl group section, and preferred acylamino groups include, for example, acetylamino, propionyl Amino, butyrylamino, isobutyrylamino, benzoylamino, naphthoylamino and the like can be mentioned.

In formula (Bk-1), in R ¹ to R ⁷ , preferred examples of the alkylsulfonylamino group include methylsulfonylamino, ethylsulfonylamino, propylsulfonylamino and the like.

In the formula (Bk-1), preferred examples of the phenylsulfonylamino group which may be substituted with a group selected from the group consisting of a halogen atom, an alkyl group or a nitro group in R ¹ to R ⁷ include, for example, benzenesulfonylamino , Toluenesulfonylamino, chlorobenzenesulfonylamino, nitrobenzenesulfonylamino and the like.

In formula (Bk-1), preferred R ¹ and R ² each independently represent a hydrogen atom, a chlorine atom, a bromine atom, a cyano group, a carboxyl group, a sulfo group, a sulfamoyl group, an N-methylaminosulfonyl group, N -Phenylaminosulfonyl group, methylsulfonyl group, hydroxyethylsulfonyl group, phosphate group, nitro group, acetyl group, benzoyl group, ureido group, methyl group, methoxy group, ethyl group, ethoxy group, propyl group, propoxy group, 2 -Hydroxyethoxy group, 2-methoxyethoxy group, 2-ethoxyethoxy group, 3-sulfopropoxy group, 4-sulfobutoxy group, carboxymethoxy group, 2-carboxyethoxy group, acetylamino group, benzoylamino group, etc. More preferably, a hydrogen atom, a chlorine atom, a cyano group, a sulfamoyl group, an aceto group Group, a nitro group, a carboxyl group or a sulfo group, more preferably a hydrogen atom, a carboxyl group or a sulfo group. Further preferred R ¹ is a carboxyl group or a sulfo group, and a sulfo group is particularly preferred. R ² is particularly preferably a hydrogen atom.

In Formula (Bk-1), when the substitution position of R ¹ is ortho to the azo group, the substitution position of the nitro group is para to the azo group, and the substitution position of R ¹ is the azo group. On the other hand, in the para position, the substitution position of the nitro group is preferably ortho to the azo group.

In formula (Bk-1), preferred R ³ and R ⁴ are each independently a hydrogen atom, a cyano group, a carboxyl group, a sulfo group, a nitro group, a methyl group, a methoxy group, an ethyl group, an ethoxy group, or a propyl group. , Propoxy group, 2-hydroxyethoxy group, 2-methoxyethoxy group, 2-ethoxyethoxy group, 3-sulfopropoxy group, 4-sulfobutoxy group, carboxymethoxy group, 2-carboxyethoxy group or acetylamino group, More preferably, they are a hydrogen atom, a carboxyl group, a sulfo group, a methyl group, a methoxy group or a 3-sulfopropoxy group, and further preferably a hydrogen atom or a sulfo group. A combination in which R ³ is a sulfo group and R ⁴ is a hydrogen atom is particularly preferable.

In formula (Bk-1), preferred R ⁵ to R ⁷ each independently represents a hydrogen atom, a chlorine atom, a bromine atom, a cyano group, a carboxyl group, a sulfo group, a sulfamoyl group, an N-methylaminosulfonyl group, N -Phenylaminosulfonyl group, methylsulfonyl group, hydroxyethylsulfonyl group, phosphate group, nitro group, acetyl group, benzoyl group, ureido group, methyl group, methoxy group, ethyl group, ethoxy group, propyl group, propoxy group, 2 -Hydroxyethoxy group, 2-methoxyethoxy group, 2-ethoxyethoxy group, 3-sulfopropoxy group, 4-sulfobutoxy group, carboxymethoxy group, 2-carboxyethoxy group, acetylamino group, benzoylamino group, etc. More preferably, a hydrogen atom, a chlorine atom, a cyano group, a sulfamoyl group, an aceto group Group, a nitro group, a carboxyl group or a sulfo group, more preferably a hydrogen atom, a carboxyl group or a sulfo group. Particularly preferred R ⁵ is a hydrogen atom, a carboxyl group or a sulfo group, particularly preferred R ⁶ is a carboxyl group or a sulfo group, and particularly preferred R ⁷ is a hydrogen atom.

In formula (Bk-1), preferred as R ¹ and R ² is one in which either one is a hydrogen atom or a sulfo group, and the other is a carboxyl group, a sulfo group, or an alkoxy group having 1 to 4 carbon atoms. Yes, more preferably, one is a hydrogen atom and the other is a carboxyl group or a sulfo group. n may be 0 or 1, but 1 is more preferable.

In the formula (Bk-1), R ³ and R ⁴ are preferably one of a sulfo group or an alkoxy group having 1 to 4 carbon atoms and the other being a hydrogen atom, a sulfo group, or 1 to 4 carbon atoms. More preferably, one is a sulfo group and the other is a hydrogen atom. In addition, preferred as R ⁵ , R ⁶ and R ⁷ are any one selected from a sulfo group, a carboxyl group, a sulfopropoxy group, a hydroxy group or a hydroxy-alkyl group having 1 to 4 carbon atoms, More preferably a sulfo group or a carboxyl group, still more preferably a sulfo group, and any one of them is a hydrogen atom, a sulfo group, a carboxyl group, an alkyl group having 1 to 4 carbon atoms, a nitro group or an aminosulfonyl group. More preferably a hydrogen atom, a sulfo group or a carboxyl group, and the remaining one is a hydrogen atom, a sulfo group, a toluenesulfonylamino group or an acetylamino group, more preferably a hydrogen atom.

  A combination of these preferable ones is more preferable, a combination of preferable ones and more preferable ones is further preferable, and a more preferable combination is most preferable.

（式（Ｂｋ−２）中、Ｚ^１、Ｚ^２、Ｚ^３、Ｚ^４は、各々独立して、アルキル基、ヒドロキシアルキル基、又はヒドロキシアルコキシアルキル基を示す。） The salt of the compound represented by the formula (Bk-1) is an inorganic or organic cation salt. Among them, specific examples of inorganic salts include alkali metal salts, alkaline earth metal salts, and ammonium salts. Preferred inorganic salts are lithium, sodium, potassium salts and ammonium salts, and organic cation salts. Examples of the salt include, but are not limited to, salts of compounds represented by the following general formula (Bk-2).

(In formula (Bk-2), Z ¹ , Z ² , Z ³ , and Z ⁴ each independently represent an alkyl group, a hydroxyalkyl group, or a hydroxyalkoxyalkyl group.)

In the formula (Bk-2), examples of the alkyl group of Z ¹ , Z ² , Z ³ , Z ⁴ include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, etc. Is mentioned. Examples of hydroxyalkyl groups are hydroxy-carbon numbers such as hydroxymethyl, hydroxyethyl, 3-hydroxypropyl, 2-hydroxypropyl, 4-hydroxybutyl, 3-hydroxybutyl, 2-hydroxybutyl, etc. Examples of the alkyl group include 1 or more and 4 or less. Examples of hydroxyalkoxyalkyl groups include hydroxyethoxymethyl, 2-hydroxyethoxyethyl, 3-hydroxyethoxypropyl, 2-hydroxyethoxypropyl, 4-hydroxyethoxybutyl, 3-hydroxyethoxybutyl, 2 -Hydroxy-C1-C4 alkoxy-C1-C4 alkyl groups, such as a hydroxyethoxybutyl group. Of these, hydroxyethoxy-alkyl groups having 1 to 4 carbon atoms are preferred. Particularly preferred are hydrogen atom; methyl group; hydroxymethyl group, hydroxyethyl group, 3-hydroxypropyl group, 2-hydroxypropyl group, 4-hydroxybutyl group, 3-hydroxybutyl group, 2-hydroxybutyl group, etc. Hydroxy-alkyl group having 1 to 4 carbon atoms; hydroxyethoxymethyl group, 2-hydroxyethoxyethyl group, 3-hydroxyethoxypropyl group, 2-hydroxyethoxypropyl group, 4-hydroxyethoxybutyl group, 3-hydroxyethoxybutyl And hydroxyethoxy-alkyl groups having 1 to 4 carbon atoms such as 2-hydroxyethoxybutyl group.

Specific examples of Z ¹ , Z ² , Z ³ and Z ^{4 in} the formula (Bk-2) are shown in Table 1.

  The compound represented by the formula (Bk-1) can be produced by a method described in Japanese Patent No. 4764829.

Although it does not specifically limit as a suitable example of a compound shown by a formula (Bk-1), The following structure is mentioned specifically.

  The first dye represented by the formula (Bk-1) has a composition ratio of 8: 2 to 9: 1 with the second dye described later. Further, the total addition amount of the first dye and the second dye is 3.0% by mass or more and 5.0% by mass or less. When the first dye and the second dye are within these ranges, it is possible to improve the image fastness and color developability of the obtained recorded matter. When the composition ratio is higher than 9: 1, the color developability is inferior, and when it is lower than 8: 2, the gas resistance and light resistance are inferior.

Further, the amount of the first dye represented by the formula (Bk-1) is preferably 2.4% by mass or more and 4.0% by mass or less, more preferably based on the total mass of the ink composition. Is 3.2% by mass
The content is 3.6% by mass or less. When the amount of the first dye represented by the formula (Bk-1) is within the above range, an ink composition for ink jet recording excellent in image fastness and color developability of the obtained recorded matter can be obtained.

1.2. Second Dye The ink composition according to the present embodiment includes a black second dye other than the first dye described above, and the composition ratio of the first dye to the second dye is 8: 2. 9: 1, and the total addition amount of the first dye and the second dye is 3.0% by mass or more and 5.0% by mass or less. Hereinafter, the second dye will be described in detail.

  In the ink composition according to the present embodiment, the second dye is a dye that functions as a colorant for the ink, and is used in combination with the first dye. Further, the content in the ink and the content of these dyes By adjusting the ratio, it is possible to improve image fastness and color developability of the obtained recorded matter. That is, an image recorded using the ink according to the present embodiment has excellent gas resistance and light resistance due to the complementary action of the first dye and the second dye, and exhibits an excellent black hue. It will be a thing.

  The amount of the second dye added is preferably 0.1% by mass or more and 2.0% by mass or less, more preferably 0.4% by mass or more and 1.6% by mass with respect to the total mass of the ink composition. It is below, More preferably, they are 0.6 mass% or more and 1.0 mass% or less. When the addition amount of the second dye is within the above range, the image fastness and color developability of the obtained recorded matter are improved.

  The second dye is not particularly limited, and examples of the water-soluble system include acidic dyes, direct dyes, reactive dyes, and basic dyes. Examples of the water-dispersed system include disperse dyes, oil-soluble dyes, and the like. Is mentioned. More specifically, examples of the acid dye include C.I. I. Acid Black 1, 2, 24, 52, 94, C.I. I. Examples of direct dyes such as food blacks 1 and 2 include C.I. I. Examples of direct black 19, 38, 51, 71, 154, 168, 195 and reactive dyes include C.I. I. Examples of basic dyes such as Reactive Black 3, 4, 5, 8, 13, 14, 31, 34, 35, 39 include C.I. I. Examples of oil-soluble dyes such as Basic Black 2 and 8 include C.I. I. Solvent black 3, 5, 7, 27, 28, 29, 34 etc. are mentioned. A dye may be used individually by 1 type and may use 2 or more types together.

  In particular, as the second dye, C.I. I. Direct black 154, 168, C.I. I. Acid Black 52, C.I. I. Reactive Black 39, C.I. I. It is preferable that it is at least 1 sort (s) selected from the group which consists of food black 2 and the compound represented by the following general formula (I)-(IV). These dyes may be used alone or in combination of two or more. In the ink according to the present embodiment, the use of these specific dyes improves the image fastness and color developability of the obtained recorded matter.

  The structural formulas of these compounds are as shown below.

（上記式（Ｉ）中、Ｍは各々独立して水素原子またはアルカリ金属である）

(In the above formula (I), each M is independently a hydrogen atom or an alkali metal)

（上記式（ＩＩ）中、Ｍは各々独立して水素原子またはアルカリ金属である）

(In the above formula (II), each M is independently a hydrogen atom or an alkali metal)

（上記式（ＩＩＩ）中、Ｍは各々独立して水素原子またはアルカリ金属である）

(In the above formula (III), each M is independently a hydrogen atom or an alkali metal)

（上記式（ＩＶ）中、Ｍは水素原子、アルカリ金属、アンモニア、および有機アミン類からなる群から選択される基の陽イオンを表し、ｍは１または２を表し、ｎは０または１を表す。）
なお、上記一般式（Ｉ）〜（ＩＶ）で表される化合物において、アルカリ金属としては、具体的にはＮａ、Ｋ、Ｌｉ等が挙げられる。

(In the above formula (IV), M represents a cation of a group selected from the group consisting of a hydrogen atom, an alkali metal, ammonia, and organic amines, m represents 1 or 2, and n represents 0 or 1) Represents.)
In the compounds represented by the general formulas (I) to (IV), specific examples of the alkali metal include Na, K, and Li.

  The dye represented by the general formula (IV) is a known dye described in US Pat. No. 4,963,189 and US Pat. No. 5,203,912, and can be produced with reference to those descriptions. It can also be produced by the method described in JP-A-2-140270, Color Index 3rd Edition (Color Index, Third Edition, The Society of Dies and Colorists).

  Specific examples of the dye represented by the above formula (IV) include Projet First Black 2 (trade name, manufactured by LANXESS) or compounds represented by the general formulas (V) to (VIII). is there.

  Since the dye represented by the formula (IV) has high color developability, it is possible to obtain high density printing even if the total amount of the color material is small.

  C. I. The direct black 154 is a mixture of compounds represented by the following general formulas (IX) and (X), and the composition ratio of the general formula (IX) :( X) is, for example, 9: 1.

C. I. Direct black 168 is a compound represented by the following general formula (XI).

C. I. Acid black 52 is a compound represented by the following general formula (XII).

C. I. Reactive black 39 is a compound represented by the following general formula (XIII).

C. I. Food Black 2 is a compound represented by the following general formula (XIV).

1.3. Third dye represented by formula (Bw-1) Hereinafter, the color material represented by formula (Bw-1) will be described in detail. The color material represented by the formula (Bw-1) is a dye for correcting the color of the color material represented by the formula (Bk-1). Therefore, the ink is used by adjusting the addition amount of the color material represented by the formula (Bk-1) and the color material represented by the formula (Bw-1) in the ink and the content ratio of these dyes. Thus, the hue of the image formed can be made close to an achromatic color easily. That is, the image recorded using the ink exhibits excellent gas resistance and light resistance due to the complementary action of the first to third dyes, and exhibits an excellent black hue.

  In addition, the color material represented by the formula (Bw-1) can be included in the ink together with the first and second dyes to obtain an image with excellent color development. In particular, even when an image is recorded with a high duty value using an ink containing the color material represented by the formula (Bk-1) and the color material represented by the formula (Bw-1), Bronze phenomenon is unlikely to occur. The “bronze phenomenon” is a phenomenon that is likely to occur when an image is recorded with a high duty value, and exhibits a hue different from the original hue, or shows a metallic luster, so that color developability and hue are reduced. It is a phenomenon that is damaged.

  Here, “duty value” means “duty (%) = number of actual ejection dots / (vertical resolution × horizontal resolution) × 100 (where“ actual ejection dots ”is the number of actual ejection dots per unit area). Yes, “vertical resolution” and “horizontal resolution are resolutions per unit area.”) ”.

In addition, the color material represented by the formula (Bw-1) has a property that is difficult to be decomposed in the ink, like the color material represented by the formula (Bk-1). Therefore, the ink is excellent in storage stability. Further, the color material represented by the formula (Bw-1) is irradiated with light or exposed to atmospheric gas, particularly ozone, like the color material represented by the formula (Bk-1). Even so, it is difficult to disassemble. For this reason, an image formed using ink is excellent in light resistance, gas resistance, and particularly ozone resistance, and therefore hardly undergoes discoloration or fading due to the influence of light or air. Note that the formula (Bk
Since the color material represented by -1) and the color material represented by the formula (Bw-1) act synergistically in the ink, the storage stability of the ink is further improved, or recording is performed using the ink. The color density, light resistance, ozone resistance and the like of the image to be produced are further improved.

  It is preferable that the addition amount of the 3rd dye represented by a formula (Bw-1) is 0.5 mass% or more and 1.5 mass% or less. When the addition amount of the third dye represented by the formula (Bw-1) is within the above range, the hue is further improved and closer to an achromatic color.

（式（Ｂｗ−１）中、Ｒ^２１、Ｒ^２２、Ｒ^２３、Ｒ^２４、Ｒ^２５、Ｒ^２６、Ｒ^２７及びＲ^２８は、各々独立して、水素原子；ハロゲン原子；スルホ基；カルボキシ基；スルファモイル基；カルバモイル基；炭素数１以上４以下のアルキル基；炭素数１以上４以下のアルコキシ基；置換基として、ヒドロキシ基、炭素数１以上４以下のアルコキシ基、ヒドロキシ−炭素数１以上４以下のアルコキシ基、スルホ基、及びカルボキシ基よりなる群から選択される少なくとも１種類の基で置換された炭素数１以上４以下のアルコキシ基；炭素数１以上４以下のアルキルカルボニルアミノ基；カルボキシ基で置換された炭素数１以上４以下のアルキルカルボニルアミノ基；ウレイド基；モノ炭素数１以上４以下のアルキルウレイド基；ジ炭素数１以上４以下のアルキルウレイド基；置換基として、ヒドロキシ基、スルホ基、及びカルボキシ基よりなる群から選択される少なくとも１種類の基で置換されたモノ炭素数１以上４以下のアルキルウレイド基；置換基として、ヒドロキシ基、スルホ基、及びカルボキシ基よりなる群から選択される少なくとも１種類の基で置換されたジ炭素数１以上４以下のアルキルウレイド基；ベンゾイルアミノ基；ベンゼン環が、ハロゲン原子、炭素数１以上４以下のアルキル基、ニトロ基、スルホ基、及びカルボキシ基よりなる群から選択される少なくとも１種類の基で置換されたベンゾイルアミノ基；ベンゼンスルホニルアミノ基；又は、ベンゼン環が、ハロゲン原子、炭素数１以上４以下のアルキル基、ニトロ基、スルホ基、及びカルボキシ基よりなる群から選択される少なくとも１種類の基で置換されたフェニルスルホニルアミノ基；を表す。） A third dye chemical structural formula represented by the formula (Bw-1) is shown below.

(In the formula (Bw-1), R ²¹ , R ²² , R ²³ , R ²⁴ , R ²⁵ , R ²⁶ , R ²⁷ and R ²⁸ are each independently a hydrogen atom; a halogen atom; a sulfo group; a carboxy group. A sulfamoyl group, a carbamoyl group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a hydroxy group, an alkoxy group having 1 to 4 carbon atoms, and a hydroxy-carbon number of 1 or more. An alkoxy group having 1 to 4 carbon atoms substituted with at least one group selected from the group consisting of an alkoxy group having 4 or less alkoxy groups, a sulfo group, and a carboxy group; an alkylcarbonylamino group having 1 to 4 carbon atoms; An alkylcarbonylamino group having 1 to 4 carbon atoms substituted with a carboxy group; a ureido group; an alkylureido group having 1 to 4 monocarbons; a dicarbon An alkylureido group having 1 or more and 4 or less; an alkylureido group having 1 to 4 monocarbons substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group, and a carboxy group as a substituent; As a substituent, an alkylureido group having 1 to 4 dicarbon atoms substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group, and a carboxy group; a benzoylamino group; A benzoylamino group substituted with at least one group selected from the group consisting of an atom, an alkyl group having 1 to 4 carbon atoms, a nitro group, a sulfo group, and a carboxy group; a benzenesulfonylamino group; or a benzene ring From a halogen atom, an alkyl group having 1 to 4 carbon atoms, a nitro group, a sulfo group, and a carboxy group A phenylsulfonylamino group substituted with at least one group selected from the group consisting of:

  In the formula (Bw-1), X represents a divalent crosslinking group.

In formula (Bw-1), examples of the halogen atom in R ^{21 to} R ²⁸ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. In these, a fluorine atom, a chlorine atom, and a bromine atom are preferable, and a chlorine atom is especially preferable.

In formula (Bw-1), examples of the alkyl group having 1 to 4 carbon atoms in R ^{21 to} R ²⁸ include straight chain or branched chain groups, and straight chain groups are preferable. Examples of the alkyl group having 1 to 4 carbon atoms include linear groups such as methyl, ethyl, n-propyl, and n-butyl; branched groups such as isopropyl, isobutyl, sec-butyl, and t-butyl. It is done. Preferable specific examples include methyl and ethyl, and methyl is particularly preferable.

In formula (Bw-1), examples of the alkoxy group having 1 to 4 carbon atoms in R ^{21 to} R ²⁸ include linear or branched ones. Specific examples include straight chain such as methoxy, ethoxy, n-propoxy and n-butoxy; branched chain such as isopropoxy, isobutoxy, sec-butoxy and t-butoxy; Preferable specific examples include methoxy and ethoxy, and methoxy is particularly preferable.

In formula (Bw-1), as a substituent in R ^{21 to} R ²⁸ , a hydroxy group, an alkoxy group having 1 to 4 carbon atoms, a hydroxy-alkoxy group having 1 to 4 carbon atoms, a sulfo group, and a carboxy group The alkoxy group having 1 to 4 carbon atoms substituted with at least one group selected from the group consisting of these substituents on any carbon atom in the alkoxy group having 1 to 4 carbon atoms Things. The number of the substituents is usually 1 or 2, preferably 1. The position of the substituent is not particularly limited, but preferably the same carbon atom is not substituted with two or more oxygen atoms. Specific examples include hydroxy-C1-C4 alkoxy groups such as 2-hydroxyethoxy, 2-hydroxypropoxy, 3-hydroxypropoxy; methoxyethoxy, ethoxyethoxy, n-propoxyethoxy, isopropoxyethoxy, n- An alkoxy group having 1 to 4 carbon atoms such as butoxyethoxy, methoxypropoxy, ethoxypropoxy, n-propoxypropoxy, isopropoxybutoxy, n-propoxybutoxy, etc .; an alkoxy group having 1 to 4 carbon atoms; 2-hydroxyethoxyethoxy, etc. Hydroxy-Alkoxy group having 1 to 4 carbon atoms; Alkoxy group having 1 to 4 carbon atoms; Alkoxy group having 1 to 4 carboxy carbon atoms such as carboxymethoxy, 2-carboxyethoxy, 3-carboxypropoxy, etc .; 2-sulfoe Carboxymethyl, 3-sulfopropoxy, one or more sulfo carbon atoms such as 4-sulfobutoxy 4 an alkoxy group; and the like.

In the formula (Bw-1), examples of the alkylcarbonylamino group having 1 to 4 carbon atoms in R ^{21 to} R ²⁸ include linear or branched ones, and linear ones are preferable. Specific examples include straight chain such as acetylamino (methylcarbonylamino), ethylcarbonylamino, propylcarbonylamino, and butylcarbonylamino; branched chain such as isopropylcarbonylamino and t-butylcarbonylamino; It is done.

In the formula (Bw-1), specific examples of the alkylcarbonylamino group having 1 to 4 carbon atoms substituted with a carboxy group in R ^{21 to} R ²⁸ include, for example, 2-carboxyethylcarbonylamino, 3-carboxypropyl And alkylcarbonylamino groups having 1 to 4 carboxy carbon atoms such as carbonylamino. The number of substitution of the carboxy group is usually 1 or 2, preferably 1.

In formula (Bw-1), examples of the alkylureido group having 1 to 4 monocarbons in R ^{21 to} R ²⁸ include those in which the alkyl moiety is linear or branched. The substitution position of the alkyl having 1 to 4 carbon atoms is not particularly limited, but is preferably substituted with “N ′”. In this specification, “an alkylureido group having 1 to 4 monocarbons” means “an alkyl NH—CO—NH— group having 1 to 4 carbon atoms” or “H ₂ N—CO—N (carbon number). 1 to 4 or less alkyl)-”group, and in the benzene ring to which R ^{21 to} R ²⁸ are bonded, the nitrogen atom directly bonded to the benzene ring is“ N ”, and the nitrogen atom and the carbonyl (CO) group are A nitrogen atom bonded through the hydrogen atom is described as “N ′”. Therefore, the substitution position of the alkyl having 1 to 4 carbon atoms is “N ′” for the former and “N” for the latter. Specific examples thereof include branched mono-n'-isopropylureido, N'-isobutylureido, N'-t-butyllaid, etc., such as N'-ethylreido, N'-propylreido, N'-butylureido, etc. A chain; and the like.

In formula (Bw-1), examples of the alkylureido group having 1 to 4 carbon atoms in R ^{21 to} R ²⁸ include linear or branched ones. The substitution position of the alkyl having 1 to 4 carbon atoms is not particularly limited, and one for each of “N” and “N ′” according to the substitution position in the “alkylureido group having 1 to 4 monocarbons”. Or “N ′” may be substituted two, but the latter is preferred. Two alkyl having 1 to 4 carbon atoms may be the same or different, but the same is preferable. Specific examples thereof include linear mono-n such as N ′, N′-dimethylureido, N ′, N′-diethylureido, N ′, N′-dipropylureido, N ′, N′-dibutylureido and the like. And branched ones such as ', N'-disopropylureido, N', N'-disobutylureido; and the like.

In formula (Bw-1), the number of monocarbons substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group, and a carboxy group as a substituent in R ^{21 to} R ²⁸ 4 Examples of the following alkylureido groups include those having these substituents on any carbon atom in the alkylureido group having 1 to 4 monocarbons. The number of the substituents is usually 1 or 2, preferably 1. The position of the substituent is not particularly limited, but preferably the same carbon atom is not substituted with a nitrogen atom and a hydroxy group. Specific examples include N′-mono (hydroxy-alkyl having 1 to 4 carbon atoms) ureido groups such as N′-2-hydroxyethylureido and N′-3-hydroxypropylureido; N′-2-sulfoethyl N′-mono (alkyl having 1 to 4 sulfo carbon atoms) ureido groups such as ureido and N′-3-sulfopropylureido; N′-carboxymethylureido, N′-2-carboxyethylureido, N′-3 -N'-mono (alkyl having 1 to 4 carboxy carbon atoms) ureido groups such as -carboxypropylureido and N'-4-carboxybutylureido;

In formula (Bw-1), the number of dicarbons substituted by at least one group selected from the group consisting of a hydroxy group, a sulfo group, and a carboxy group as a substituent in R ^{21 to} R ²⁸ is 1 or more and 4 Examples of the alkylureido group below include those having these substituents on any carbon atom in the alkylureido group having 1 to 4 carbon atoms. The number of the substituents is usually 1 or 2, preferably 2. The position of the substituent is not particularly limited, but preferably the same carbon atom is not substituted with a nitrogen atom and a hydroxy group. Moreover, when it has two or more substituents, the kind may be same or different, but the same thing is preferable. Specific examples include N ′, N′-di (2-hydroxyethyl) ureido, N ′, N′-di (2-hydroxypropyl) ureido, N ′, N′-di (3-hydroxypropyl) ureido and the like. N ′, N′-di (hydroxy-alkyl having 1 to 4 carbon atoms) ureido group; N ′, N′-di (sulfocarbon number) such as N ′, N′-di (3-sulfopropyl) ureido 1) or more and 4 or less alkyl) ureido group; N ′, N′-di (carboxy having 1 or more and 4 or less alkyl) ureido group such as N ′, N′-di (carboxymethyl) ureido;

In formula (Bw-1), the benzene ring in R ^{21 to} R ²⁸ is a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are mentioned as the substituent, and a chlorine atom is particularly preferable). The benzoylamino group substituted with at least one group selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a nitro group, a sulfo group, and a carboxy group includes 1 to 3 of these substituents. Preferably, those having 1 or 2 are mentioned. When there are a plurality of substituents, the types may be the same or different, and the same type is preferred. Specific examples thereof include halogen-substituted benzoylamino groups such as 2-chlorobenzoylamino, 4-chlorobenzoylamino, 2,4-dichlorobenzoylamino; 2-methylbenzoylamino, 3-methylbenzoylamino, 4-methylbenzoyl C1-C4 alkyl-substituted benzoylamino groups such as amino; 2-nitrobenzoylamino, 4-nitrobenzoylamino, nitro-substituted benzoylamino groups such as 3,5-dinitrobenzoylamino; 2-sulfobenzoylamino, 4 -A sulfo-substituted benzoylamino group such as sulfobenzoylamino; a carboxy-substituted benzoylamino group such as 2-carboxybenzoylamino, 4-carboxybenzoylamino, 3,5-dicarboxybenzoylamino; and the like.

In formula (Bw-1), in R ^{21 to} R ²⁸ , benzene is at least one group selected from the group consisting of a halogen atom, an alkyl group having 1 to 4 carbon atoms, a nitro group, a sulfo group, and a carboxy group. Examples of the phenylsulfonylamino group having a ring substituted include those having 1 to 3, preferably 1 or 2, and more preferably 1 of these substituents. When having a plurality of substituents, the types thereof may be the same or different. Specific examples thereof include halogen atom-substituted phenylsulfonylamino groups such as 2-chlorophenylsulfonylamino and 4-chlorophenylsulfonylamino; 2-methylphenylsulfonylamino, 4-methylphenylsulfonylamino, 4-t-butylphenylsulfonylamino and the like. An alkyl-substituted phenylsulfonylamino group having 1 to 4 carbon atoms; a nitro-substituted phenylsulfonylamino group such as 2-nitrophenylsulfonylamino, 3-nitrophenylsulfonylamino, 4-nitrophenylsulfonylamino; 3-sulfophenylsulfonylamino , Sulfo-substituted phenylsulfonylamino groups such as 4-sulfophenylsulfonylamino; carboxy positions such as 3-carboxyphenylsulfonylamino and 4-carboxyphenylsulfonylamino Phenylsulfonylamino group; and the like.

In formula (Bw-1), R ^{21 to} R ²⁸ are each substituted with a hydrogen atom; a halogen atom; an alkyl group having 1 to 4 carbon atoms; an alkoxy group having 1 to 4 carbon atoms; a sulfo group or a carboxy group. A Cl-C4 alkoxy group; an alkylcarbonylamino group having 1 to 4 carbon atoms; Among these, a hydrogen atom, methyl, ethyl, t-butyl, 2-carboxyethoxy, 3-carboxypropoxy, 2-sulfoethoxy, 3-sulfopropoxy, 4-sulfobutoxy are more preferable. Furthermore, among these, a hydrogen atom, methyl, and 3-sulfopropoxy are particularly preferable.

In formula (Bw-1), as R ^{21 to} R ²⁸ , an alkoxy group having 1 to 4 carbon atoms in which at least one is substituted with a sulfo group is preferable. Further, independently R ²¹ to R ²⁴ are each a hydrogen atom, an alkyl group, or a sulfo-substituted alkoxy group having 1 to 4 carbon atoms in the group having 1 to 4 carbon atoms, and, R ²¹ ~ R ²⁴ is an alkoxy group having 1 to 4 carbon atoms in which at least one of R ²⁴ is substituted with a sulfo group, and R ^{25 to} R ²⁸ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. preferable. Also, at least one of R ²¹ and R ²² is a sulfopropoxy group, at least one of R ²³ and R ²⁴ is a sulfopropoxy group, and R ^{25 to} R ²⁸ are alkyl groups having 1 to 4 carbon atoms. Is more preferable.

In formula (Bw-1), the substitution positions of R ^{21 to} R ²⁸ are not particularly limited, but in each benzene ring substituted by these, the substitution position of the nitrogen atom bonded to the triazine ring is the 1st position, and the substitution of the azo group It is preferable that R ^{21 to} R ²⁴ be substituted at the 2-position and R ^{25 to} R ²⁸ be substituted at the 5-position with the position being the 4-position.

In the formula (Bw-1), the crosslinking group representing X is not particularly limited as long as the compound represented by the formula (Bw-1) is divalent within the range in which the compound is soluble in water. Here, as the solubility of the compound represented by the formula (Bw-1) in water, the compound represented by the formula (Bw-1) with respect to 1 liter of water is usually 5 g or more, preferably 10 g or more. More preferably, it is 25 g or more, more preferably 50 g or more, and particularly preferably 100 g or more. Specific examples thereof include a divalent atom (preferably a divalent heteroatom) such as a nitrogen atom, an oxygen atom or a sulfur atom; an alkylenediamino group, an alkylenedioxy group or an alkylenedithio group each of C1-C8; N N′-hydrazinediyl group; an aminoalkoxyalkylamino group substituted with two alkylamino groups on an oxygen atom; and the end of an alkylene oxide chain containing one or more ether bonds such as an aminoalkoxyalkoxyalkylamino group In which one amino group and one alkylamino group are substituted; The divalent bridging group representing X is a group selected from the group consisting of a hydroxy group, a carboxy group, and an alkoxy group as a carbon atom substituent; and, as a nitrogen atom substituent, an alkyl moiety is a hydroxy group or Each may have an alkyl group optionally substituted with a carboxy group;

  In the formula (Bw-1), the divalent bridging group representing X includes a C1-C8 alkylenediamino group; a C1-C8 alkylenediamino group substituted with a hydroxy group or a carboxy group; An alkyl-C1-C6 alkylenediamino group; an alkyl-C1-C6 alkylenediamino group having 1 to 4 carbon atoms in which the alkyl moiety is substituted with a hydroxy group or a carboxy group; amino C1-C6 alkoxy C1-C6 alkylamino A group: an alkoxy having 1 to 4 amino carbons; an alkoxy having 1 to 4 carbons; an alkylamino group having 1 to 4 carbons; a xylylenediamine group; a piperazine-1,4-diyl group; Piperazine-1,4-dii substituted with an alkyl group of 4 or less or an alkoxy group of 1 to 4 carbon atoms Group; or phenylene amino group; or a group selected from the group consisting of is preferred. These divalent bridging groups are all “diamino” groups having two amino groups. Thus, the “diamino”, except for some groups such as piperazine-1,4-diyl, is bridged by any one nitrogen atom (ie, becomes N, N-diyl), or two different In the case of crosslinking with a nitrogen atom (that is, N, N′-diyl), both of them are included. Of these, the latter case of “N, N′-diyl” is particularly preferred.

  In formula (Bw-1), examples of the C1-C8 alkylenediamino group for X include straight-chain or branched-chain groups, and straight-chain groups are preferred. The range of carbon number is usually C1-C8, preferably C2-C8, more preferably C2-C6, and still more preferably C2-C4. Specific examples thereof include ethylene diamino, 1,3-propylene diamino, 1,4-butylene diamino, 1,5-pentylene diamino, 1,6-hexylene diamino, 1,7-heptylene diamino, , 8-octylenediamino, etc .; branched chain such as 2-methyl-1,3-propylenediamino, 3-methyl-1,4-butylenediamino, 4-methyl-1,6-hexylenediamino; Etc.

In formula (Bw-1), the C1-C8 alkylenediamino group substituted with a hydroxy group or a carboxy group in X has these substituents on any carbon atom in the C1-C8 alkylenediamino group. Is mentioned. The number of the substituent is not particularly limited, but is preferably 1 or 2. Moreover, when it has two or more substituents, the kind may be same or different, and the same thing is preferable. Specific examples thereof include hydroxy-substituted C1-C8 alkylene diamino groups such as 2-hydroxy-1,3-propylene diamino, 2-hydroxy 1,4-butylene diamino, 3-hydroxy-1,6-hexylene diamino; 1-carboxyethylenediamino, 1-carboxy-1,3-propylenediamino, 1-carboxy-1,4-butylenediamino, 1-carboxy-1,5-pentylenediamino, 1,5-dicarboxy-1,5 -Carboxy substituted C1-C8 alkylene diamino group such as pentylenediamino; and the like.

In formula (Bw-1), as X-alkyl-C1-C6 alkylenediamino group having 1 to 4 carbon atoms in X, one nitrogen atom of C1-C6 alkylenediamino group has 1 to 4 carbon atoms Substituted with an alkyl group. In the present specification, a nitrogen atom substituted with an alkyl group having 1 to 4 carbon atoms in a diamino group is represented as “N”, and the other nitrogen atom is represented as “N ′” as necessary. The range of the number of carbon atoms in the alkylene moiety is usually C1-C6, preferably C2-C4, particularly preferably C2 or C3. Examples of the alkyl group having 1 to 4 carbon atoms include straight-chain or branched-chain groups, and straight-chain groups are preferred. Specific examples thereof include alkyl-C1-C6 having 1 to 4 carbon atoms, such as N-methylethylenediamino group, N-ethylethylenediamino group, N-propylethylenediamino group, and N-butylethylenediamino group. Alkylenediamino group; N-branched alkyl group having 1 to 4 carbon atoms such as N-isopropylethylenediamino group, N-isobutylethylenediamino group, N-sec-butylethylenediamino group, and N-tert-butylethylenediamino group. -C6 alkylene diamino group; and the like.

  In formula (Bw-1), the N-C1-C6 alkylenediamino group having 1 to 4 carbon atoms in which the alkyl moiety in X is substituted with a hydroxy group or a carboxy group is the N-carbon number of 1 or more. What has these substituents in the arbitrary carbon atoms of the alkyl part of a C1-C4 alkyl group in a 4 or less alkyl-C1-C6 alkylene diamino group is mentioned. The position of the substituent is not particularly limited, but it is preferable that the nitrogen atom and the hydroxy group are not substituted with the same carbon atom. Examples of the range of the number of carbon atoms in the alkylene moiety include the same range as in the above-mentioned alkyl-C1-C6 alkylenediamino group having 1 to 4 carbon atoms. Further, the range of the carbon number of the alkyl moiety is usually 1 to 4 carbon atoms, preferably C2-C4, more preferably C2-C3. The number of the substituents is usually 1 or 2, preferably 1. Moreover, when it has two or more substituents, the kind may be same or different, but the same thing is preferable. Specific examples thereof include N- (2-hydroxyethyl) ethylenediamino group, N- (3-hydroxypropyl) ethylenediamino group, N- (2-hydroxypropyl) ethylenediamino group, N- (4-hydroxybutyl). N-hydroxy substituted 1 to 4 alkyl-C1-C6 alkylenediamino group such as ethylenediamino group; N- (carboxymethyl) ethylenediamino group, N- (2-carboxyethyl) ethylenediamino group, N- ( 3-carboxypropyl) ethylenediamino group, N- (4-carboxybutyl) ethylenediamino group and the like N-carboxy-substituted C1-C4 alkyldiamino group having 1 to 4 carbon atoms;

  In formula (Bw-1), examples of the amino C1-C6 alkoxy C1-C6 alkylamino group for X include straight-chain or branched-chain groups, and straight-chain groups are preferred. Among amino C1-C6 alkoxy C1-C6 alkylamino groups, those having a preferred carbon number range include amino C2-C4 alkoxy C2-C4 alkylamino groups, and those having a particularly preferred carbon number range. An amino C2-C3 alkoxy C2-C3 alkylamino group is mentioned. Specific examples thereof include aminoethoxyethylamino, aminoethoxypropylamino, aminopropoxypropylamino, aminoethoxypentylamino and the like.

  In formula (Bw-1), in X, an alkoxy having 1 to 4 amino carbons and an alkylamino group having 1 to 4 carbons having 1 to 4 carbon atoms are linear or branched. The straight chain is preferable. In addition, amino C1-C4 alkoxy C1-C4 alkoxy-C1-C4 alkoxyamino group C1-C4 alkylamino group having a preferable carbon number as an amino C2-C4 alkoxy C2-C4 An alkoxy C2-C4 alkylamino group can be mentioned, and an amino C2-C3 alkoxy C2-C3 alkoxy C2-C3 alkylamino group can be mentioned as a particularly preferred carbon number range. Specific examples thereof include a straight chain such as aminoethoxyethoxyethylamino, aminoethoxypropoxyethylamino, aminoethoxybutoxyethylamino; aminoethoxy (2-methylethoxy) ethylamino, aminoethoxy (2-methylpropoxy) ethyl Branched chain such as amino; and the like.

  In the formula (Bw-1), examples of the xylylenediamino group in X include o-xylylenediamino group, m-xylylenediamino group, and p-xylylenediamino group, and m-xylylenediamino group or A p-xylylenediamine group is preferred.

  In formula (Bw-1), the piperazine-1,4-diyl group substituted with an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms in X is a ring structure of a piperazine ring. Those having these substituents on any carbon atom of the atom are exemplified. The number of the substituents is usually 1 or 2, preferably 1. Moreover, when it has two or more substituents, the kind may be the same or different, and the same thing is preferable. Specific examples thereof include 2-methylpiperazine-1,4-diyl group, 2-ethylpiperazine-1,4-diyl group, 2,5-dimethylpiperazine-1,4-diyl group, 2,6-dimethylpiperazine. -1,4-diyl group, 2,5-diethylpiperazine-1,4-diyl group, 2-methyl 5-ethylpiperazine-1,4-diyl group; and the like.

  In formula (Bw-1), examples of the phenylenediamino group in X include o-, m-, and p-phenylenediamino groups, and m- or p-phenylenediamino groups are preferred.

  Among these, X is a C1-C8 alkylene diamino group; a C1-C8 alkylene diamino group substituted with a carboxy group; an N-carbon number of 1 to 4 alkyl-C1-C6 with an alkyl moiety substituted with hydroxy. An alkylenediamino group; an alkoxy having 1 to 4 amino carbon atoms, an alkoxy having 1 to 4 carbon atoms; an alkylamino group having 1 to 4 carbon atoms; a xylylenediamine group; or a piperazine-1,4-diyl group. It is preferable. Among these, X is more preferably a C1-C8 alkylenediamino group; a xylylenediamine group; or a piperazine-1,4-diyl group. Among these, preferred specific examples include 1,2-ethylenediamino: 1,3-propylenediamino; 1,4-butylene diamino; 1-carboxypentylene-1,5-diamino; N-2-hydroxyethyl- And ethylenediamino; aminoethoxyethoxyethylamino; m-xylylenediamine; or piperazine-1,4-diyl.

  In formula (Bw-1), the substitution positions of the four sulfo groups whose substitution positions are not specified are not particularly limited. The sulfo group substituted on the benzene ring having one azo bond may be substituted at the 2, 3 or 4 position, preferably at the 4 position, with the substitution position of the azo bond as the 1 position.

  The colorant represented by the formula (Bw-1) is preferably a compound represented by the following formula (Bw-1-1), and is a compound represented by the following formula (Bw-1-2). It is more preferable.

（上記式（Ｂｗ−１−１）中、Ｒ^２１〜Ｒ^２８及びＸは、式（Ｂｗ−１）におけるものと同じ意味を表す。）

（上記式（Ｂｗ−１−２）中、Ｒ^２１〜Ｒ^２８及びＸは、式（Ｂｗ−１）におけるものと同じ意味を表す。）

(In the above formula (Bw-1-1), R ^{21 to} R ²⁸ and X represent the same meaning as in the formula (Bw-1).)

(In the above formula (Bw-1-2), R ^{21 to} R ²⁸ and X represent the same meaning as in formula (Bw-1).)

Formula (Bw-1) ~ (Bw -1-2) in ^R 21 ^{to R 28,} the substitution position of ^R 21 ^{to R 28} in Formula (Bw-1), and formula (Bw-1) and Formula (Bw-1 As for the substitution position of sulfo in which the substitution position in -1) is not specified, compounds in which preferable ones are combined are more preferable, and those in which more preferable ones are combined are more preferable. The same applies to preferable combinations, preferable combinations and more preferable combinations.

  The salt of the compound represented by the formula (Bw-1) can be an inorganic or organic cation salt. Inorganic salts include alkali metal salts, alkaline earth metal salts, and ammonium salts. Among these, preferred inorganic salts are alkali metal salts such as lithium, sodium and potassium, and ammonium salts. Examples of organic cation salts include, but are not limited to, quaternary ammonium ions represented by the above formula (Bk-2).

Moreover, a mixture may be sufficient as the free acid of the coloring material represented by a formula (Bw-1), and those various salts. For example, a mixture of a sodium salt of the coloring material represented by the formula (Bw-1) and an ammonium salt of the coloring material represented by the formula (Bw-1), a coloring material represented by the formula (Bw-1) Mixture of free acid and sodium salt of coloring material represented by formula (Bw-1), lithium salt of coloring material represented by formula (Bw-1), coloring material represented by formula (Bw-1) Any combination such as a mixture of a sodium salt of A and a ammonium salt of a coloring material represented by the formula (Bw-1) may be used. Depending on the type of salt, the physical properties such as solubility may differ, and if necessary, select the type of salt as appropriate, or change the ratio when multiple salts are included. A mixture having excellent physical properties can be obtained.

  Although it does not specifically limit as a suitable specific example of the coloring material represented by Formula (Bw-1), The compound etc. which are represented with the structural formula shown below are mentioned. In each table, functional groups such as a sulfo group and a carboxy group are described in the form of a free acid for convenience.

  The method for synthesizing the color material represented by the formula (Bw-1) is not particularly limited, but for example, the method described in JP 2012-172031 A can be used.

  The addition amount of the color material represented by the formula (Bw-1) is preferably 0.050% by mass or more and 3.0% by mass or less, and more preferably 0.10% by mass or more with respect to the total amount of the ink. It is 2.0 mass% or less, More preferably, it is 0.50 mass% or more and 1.5 mass% or less. When the addition amount of the coloring material represented by the formula (Bw-1) is within the above range, it tends to exhibit excellent black color by visual observation.

1.4. The alkylene oxide adduct of acetylene glycol having a main chain having 12 or more carbon atoms The ink composition of the present embodiment contains an acetylene glycol alkylene oxide adduct having a main chain having 12 or more carbon atoms. By including an alkylene oxide adduct of acetylene glycol, the initial filling property is improved, color reproducibility and bleeding are suppressed, and the image quality tends to be further improved.

  An alkylene oxide adduct of acetylene glycol having a main chain having 12 or more carbon atoms (hereinafter also referred to as “acetylene glycol A”) is included in an acetylene glycol surfactant (nonionic surfactant). . The nonionic surfactant has an action of spreading the ink uniformly on the recording medium. Therefore, when ink jet recording is performed using an ink containing a nonionic surfactant, a relatively high-definition image with little bleeding can be obtained. In the present specification, “main chain” means a main chain based on the IUPAC nomenclature.

  In particular, since acetylene glycol A has 12 or more carbon atoms in the main chain, it has excellent wettability with respect to foreign substances that can contribute to the generation of bubbles in a polymer member such as rubber or plastic that constitutes the ink flow path and ink. . Therefore, by using acetylene glycol A, it is possible to suppress the generated bubbles from remaining on the flow path surface of the polymer member from the ink tank to the head. In addition, this makes it possible to improve the initial filling property and to prevent the dot growth due to the growth of the remaining bubbles and the detachment of the bubbles adhering to the flow path surface, thereby improving the continuous printing stability. Furthermore, since acetylene glycol A is an alkylene oxide adduct, it has excellent solubility in ink.

The HLB (Hydrophile-Lipophile Balance) value of acetylene glycol A is preferably 4 or more and 15 or less because the above-described wettability is further improved. Here, the HLB value is an HLB value defined by the Griffin method.

上記式（１）中、Ｒ^１、Ｒ^１’、Ｒ^２、及びＲ^２’は互いに独立して炭素数１以上５以下のアルキル基を表し、主鎖の炭素数は１２以上であり、−ＯＲ^３は−ＯＨ又は−Ｏ（Ｃ_２Ｈ_４Ｏ）_ｍＨを表し、−ＯＲ^３’は−ＯＨ又は−Ｏ（Ｃ_２Ｈ_４Ｏ）_ｎＨを表す。その際、ｍ及びｎは互いに独立して０．５以上２５以下の小数を含む値であり、ｍ＋ｎは１以上４０以下の小数を含む値である（ただし、−ＯＲ^３及び−ＯＲ^３’が共に−ＯＨである場合を除く。）。 Although not limited to the following as acetylene glycol A, For example, the compound represented by following formula (1) is mentioned.

In the above formula (1), R ¹ , R ^{1 ′} , R ² and R ^{2 ′} each independently represent an alkyl group having 1 to 5 carbon atoms, the main chain has 12 or more carbon atoms, OR ³ represents —OH or —O (C ₂ H ₄ O) _m H, and —OR ^{3 ′} represents —OH or —O (C ₂ H ₄ O) _n H. In this case, m and n are values including a decimal number of 0.5 or more and 25 or less independently of each other, and m + n is a value including a decimal number of 1 or more and 40 or less (provided that -OR ³ and -OR ^{3 '} are Except when both are —OH).

  Specific examples of acetylene glycol A are not particularly limited. For example, 2,5,8,11-tetramethyl-6-dodecin-5,8-diol ethoxylate and 5,8-dimethyl-6-dodecin- An ethoxylated product of 5,8-diol may be mentioned. Among the alkylene oxide adducts of acetylene glycol, an ethylene oxide adduct of acetylene glycol and a propylene oxide adduct of acetylene glycol are preferable, and an ethylene oxide adduct of acetylene glycol is more preferable.

The added mole number of the alkylene oxide unit in acetylene glycol is preferably 1 mol or more and 20 mol or less in each of R ³ and R ^{3 ′} . The total number of added moles (total of R ³ and R ^{3 ′} ) is preferably 2 mol or more and 40 mol or less. When the total number of added moles of alkylene oxide is 40 moles or less, static and dynamic surface tension can be reduced, and ink absorption performance is improved.

  Examples of commercially available acetylene glycol A include, but are not limited to, Olfin EXP4300 (trade name, manufactured by Nissin Chemical Industry CO., Ltd., carbon number 12-ethylene oxide adduct). It is done.

  Acetylene glycol A may be used individually by 1 type, and may be used in combination of 2 or more type.

  The addition amount of acetylene glycol A contained in the ink is preferably 0.050% by mass or more and 2.5% by mass or less, more preferably 0.10% by mass or more and 2.0% by mass with respect to the total amount of the ink. Or less, more preferably 0.50% by mass or less and 1.5% by mass or more. When the addition amount of acetylene glycol A is 0.050% by mass or more, the wettability to the hydrophobic surface is increased and the filling property tends to be further improved. Moreover, when the addition amount of acetylene glycol A is 2.5 mass% or less, there exists a tendency for melt | dissolution stability to improve more.

1.5. Acetylene glycol having 10 or more carbon atoms in the main chain The ink composition according to this embodiment contains acetylene glycol having 10 or more carbon atoms in the main chain. Acetylene glycol having 10 or more carbon atoms in the main chain is excellent in defoaming properties and can effectively defoam bubbles generated during the introduction of ink into an ink container or the like. Thereby, initial filling property and continuous printing stability are improved.

  The HLB value of acetylene glycol having 10 or more carbon atoms in the main chain is preferably 7 or less, more preferably 5 or less, and even more preferably 4 or less. The lower limit is preferably 3 or more. When the HLB value is within the above range, the antifoaming property tends to be more excellent.

上記式（２）中、Ｒ^４、Ｒ^４’、Ｒ^５、及びＲ^５’は、互いに独立して、直鎖状又は分岐状の、炭素数１〜５のアルキル基を表す。また、アセチレングリコールの主鎖の炭素数は１０以上であり、好ましくは１０以上１４以下である。 The acetylene glycol having 10 or more carbon atoms in the main chain is not particularly limited, and specific examples include acetylene glycol represented by the following formula (2).

In the above formula (2), R ⁴ , R ⁴ ′, R ⁵ , and R ⁵ ′ each independently represent a linear or branched alkyl group having 1 to 5 carbon atoms. Further, the carbon number of the main chain of acetylene glycol is 10 or more, preferably 10 or more and 14 or less.

  The acetylene glycol having 10 or more carbon atoms in the main chain is not particularly limited. Specifically, 2,5,8,11-tetramethyl-6-dodecin-5,8-diol (manufactured by Air Products; Surfynol DF110D), 5,8-dimethyl-6-dodecin-5,8-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol (manufactured by Air Products; Surfynol 104PG50) ) And 4,7-dimethyl-5-decyne-4,7-diol.

  Acetylene glycol having 10 or more carbon atoms in the main chain may be used alone or in combination of two or more. The addition amount of acetylene glycol having 10 or more carbon atoms in the main chain is preferably 0.05% by mass or more and 0.30% by mass or less with respect to the total mass (100% by mass) of the ink-jet ink, More preferably, it is 0.10% by mass or more and 0.20% by mass or less. When the addition amount is in the above range, the continuous printing stability tends to be more excellent.

  The total addition amount of acetylene glycol having 10 or more carbon atoms in the main chain and the above-described acetylene glycol A (hereinafter also referred to as “acetylene glycol compound”) is 0.1% by mass or more and 0.6% by mass or less. Is preferable, and 0.1 mass% or more and 0.5 mass% or less are more preferable. When the addition amount is in the above range, the solubility in water becomes better, and it tends to more effectively prevent the formation of aggregates when these acetylene glycols are blended.

  The mass ratio of the addition amount of acetylene glycol having 10 or more carbon atoms in the main chain and the addition amount of acetylene glycol A described above is 10 or more carbon atoms in the main chain with respect to the addition amount 1 of the alkylene oxide adduct. The addition amount of acetylene glycol is preferably 0.5 or more and 2.5 or less, more preferably 0.5 or more and 2.0 or less, and further preferably 0.5 or more and 1.5 or less. preferable. When the mass ratio is in the above range, the initial filling property and the continuous printing stability are more excellent.

1.6. Polyoxyalkylene alkyl ether The ink composition according to this embodiment contains a polyoxyalkylene alkyl ether. By containing polyoxyalkylene alkyl ether, the solubility and dispersibility of the above-mentioned acetylene glycol A are further improved, and the initial filling property is improved. In addition, polyoxyalkylene alkyl ether hardly affects the low dynamic surface tension of acetylene glycol A described above.

  By the way, since the ink continuous supply system (CISS) often uses an ink flow path and an ink tank made of a hydrophobic material, each ink is relatively hydrophobic in the ink set used in the ink continuous supply system. It is effective to use a surfactant. From this viewpoint, it is effective to use acetylene glycol A. From the viewpoint of improving dissolution stability, initial filling property, and continuous printing stability while obtaining the effects of acetylene glycol A, this embodiment is particularly preferred. When the ink composition according to the above is used for a recording apparatus equipped with a continuous ink supply system (CISS), it is preferable that the ink contains a polyoxyalkylene alkyl ether.

  Here, the “ink supply system” refers to an ink container (ink tank) having an air inlet, a print head having a nozzle for discharging the liquid in the ink container, the ink container, and the print head. And an ink supply path for supplying the liquid from the ink container to the print head.

  The “ink channel” refers to a channel for distributing ink in the ink jet recording apparatus. As the ink flow path, for example, an ink supply path for supplying ink from an ink container that stores ink to the ink jet recording head, or a flow path for distributing ink to the nozzle opening in the ink jet recording head Is mentioned.

  The HLB value of the polyoxyalkylene alkyl ether is preferably 11 or more and 16 or less, more preferably 12 or more and 15 or less. When the HLB value of the polyoxyalkylene alkyl ether is within the above range, the initial filling property and the continuous printing stability tend to be further improved.

Examples of the polyoxyalkylene alkyl ether include, but are not limited to, compounds represented by the following formula (2). By using such a polyoxyalkylene alkyl ether, storage stability and continuous printing stability tend to be further improved.
R ⁶ O (C ₂ H ₄ O) _w (C ₃ H ₆ O) _x (C ₂ H ₄ O) _y (C ₃ H ₆ O) _z H (2)
In the above formula (2), R ⁶ represents an alkyl group having 1 to 20 carbon atoms, preferably an alkyl group having 5 to 15 carbon atoms, more preferably an alkyl group having 10 to 15 carbon atoms. Represent. Further, w is a value of 1 or more and 20 or less, and x, y, and z are 0 or a value of 1 or more and 20 or less independently of each other. Furthermore, w, x, y, and z satisfy 5 ≦ w + x + y + z ≦ 30, and preferably satisfy 5 ≦ w + x + y + z ≦ 25. By using the polyoxyalkylene alkyl ether as described above, it tends to be more excellent in storage stability and continuous printing stability.

Although it does not specifically limit as polyoxyalkylene alkyl ether, Specifically,
_{C 12 H 25 O (C 2} H 4 O) 6 (C 3 H 6 O) 2 (C 2 H 4 O) 6 (C 3 H 6 O) 8 H,
_{C 13 H 27 O (C 2} H 4 O) 6 (C 3 H 6 O) 2 (C 2 H 4 O) 6 (C 3 H 6 O) 8 H,
_{C 12 H 25 O (C 2} H 4 O) w (C 3 H 6 O) x (C 2 H 4 O) y (C 3 H 6 O) z H,
(Where w + y = 15, x + z = 4),
_{C 13 H 27 O (C 2} H 4 O) w (C 3 H 6 O) x (C 2 H 4 O) y (C 3 H 6 O) z H,
(Where w + y = 15, x + z = 4),
_{C 12 H 25 O (C 2} H 4 O) 8 (C 3 H 6 O) 2 (C 2 H 4 O) 6 H,
_{C 13 H 27 O (C 2} H 4 O) 8 (C 3 H 6 O) 2 (C 2 H 4 O) 6 H,
_{C 12 H 25 O (C 2} H 4 O) 12 (C 3 H 6 O) 2 (C 2 H 4 O) 12 H,
_{C 13 H 27 O (C 2} H 4 O) 12 (C 3 H 6 O) 2 (C 2 H 4 O) 12 H,
_{CH 3 (CH 2) 9 (} CH 3) CHO (C 2 H 4 O) 7 (C 3 H 6 O) 4.5 H,
_{CH 3 (CH 2) 11 (} CH 3) CHO (C 2 H 4 O) 7 (C 3 H 6 O) 4.5 H,
_{CH 3 (CH 2) 9 (} CH 3) CHO (C 2 H 4 O) 5 (C 3 H 6 O) 3.5 H,
_{CH 3 (CH 2) 11 (} CH 3) CHO (C 2 H 4 O) 5 (C 3 H 6 O) 3.5 H,
_{C 14 H 29 O (C 2} H 4 O) 14 (C 3 H 6 O) 2 H,
C ₁₁ H ₂₃ O (C ₂ H ₄ O) ₈ H,
C ₁₀ H ₂₁ O (C ₂ H ₄ O) ₁₁ H, and C ₁₂ H ₂₅ O (C ₂ H ₄ O) ₁₅ H.

Although it does not specifically limit as a commercial item of polyoxyalkylene alkyl ether, Specifically,
Noigen ^{_{DL-0415 (R 6 O (}} C 2 H 4 O) W (C 3 H 6 O) x (C 2 H 4 O) y (C 3 H 6 O) z H, ^{"R 6":} 12 carbon atoms , 13 alkyl, w + y = 15, x + z = 4, HLB value 15.0),
Neugen ET-116B (R ⁶ O (C ₂ H ₄ O) ₇ (C ₃ H ₆ O) _4.5 H, “R ⁶ ”: alkyl having 12 and 14 carbon atoms, HLB value 12.0),
Neugen ET-106A (R ⁶ O (C ₂ H ₄ O) ₅ (C ₃ H ₆ O) _3.5 H, “R ⁶ ”: alkyl having 12 and 14 carbon atoms, HLB value 10.9),
Neugen DH-0300 (R ⁶ O (C ₂ H ₄ O) ₂ H, “R ⁶ ”: alkyl having 14 carbon atoms, HLB value 4.0),
Neugen YX-400 (R ⁶ O (C ₂ H ₄ O) ₄₀ H, “R ⁶ ”: alkyl having 12 carbons, HLB value 18.1),
Neugen EA-160 (C ₉ H ₁₉ C ₆ H ₄ O (C ₂ H ₄ O) _16.8 H, HLB value 15.4) (above, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and Emulgen 1108 (manufactured by Kao Corporation) Trade name, R ⁶ O (C ₂ H ₄ O) ₈ H, “R ⁶ ”: alkyl having 11 carbon atoms, HLB value 13.4).

  A polyoxyalkylene alkyl ether may be used individually by 1 type, and may be used in combination of 2 or more type.

  The addition amount of the polyoxyalkylene alkyl ether contained in the ink composition according to the present embodiment is preferably 0.10% by mass or more and 10% by mass or less, more preferably 0.50% by mass with respect to the total amount of the ink. It is 7.5 mass% or less, More preferably, it is 1.0 mass% or more and 5.0 mass% or less. When the addition amount of the polyoxyalkylene alkyl ether is within the above range, the storage stability and the continuous printing stability are further improved.

  The addition amount of the polyoxyalkylene alkyl ether is preferably 1.0 part by mass or more and 5.0 parts by mass or less, more preferably 1.5 parts by mass with respect to 1.0 part by mass of the addition amount of acetylene glycol A. It is not less than 3.0 parts by mass. When the addition amount of the polyoxyalkylene alkyl ether is within the above range, the acetylene glycol A is sufficiently solubilized and the water solubility tends to be good. For this reason, it is possible to suppress the occurrence of aggregates and the occurrence of variations in ink absorbency when blended.

1.7. Surfactants other than those described above The ink used in the present embodiment may contain a surfactant other than those described above. Although it does not specifically limit as the said surfactant, For example, at least any one of a fluorine-type surfactant and a silicone type surfactant is preferable.

  The fluorosurfactant is not particularly limited. For example, perfluoroalkyl sulfonate, perfluoroalkyl carboxylate, perfluoroalkyl phosphate, perfluoroalkyl ethylene oxide adduct, perfluoroalkyl betaine, perfluoroalkyl betaine, A fluoroalkylamine oxide compound is mentioned. Although it does not specifically limit as a commercial item of a fluorochemical surfactant, For example, S-144, S-145 (Asahi Glass Co., Ltd. product); FC-170C, FC-430, Fluorard-FC4430 (Sumitomo 3M Co., Ltd. product) FSO, FSO-100, FSN, FSN-100, FS-300 (manufactured by Dupont); FT-250, 251 (manufactured by Neos Co., Ltd.) and the like. A fluorine-type surfactant may be used individually by 1 type, and may use 2 or more types together.

  Examples of silicone surfactants include polysiloxane compounds and polyether-modified organosiloxanes. Although it does not specifically limit as a commercial item of a silicone type surfactant, Specifically, BYK-306, BYK-307, BYK-333, BYK-341, BYK-345, BYK-346, BYK-347, BYK -348, BYK-349 (above trade name, manufactured by Big Chemie Japan Co., Ltd.), KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-640 , KF-642, KF-643, KF-6020, X-22-4515, KF-6011, KF-6012, KF-6015, KF-6017 (all trade names, manufactured by Shin-Etsu Chemical Co., Ltd.), and the like.

1.8. Solvent The ink composition according to this embodiment may further contain a solvent. Although it does not specifically limit as a solvent, For example, an organic solvent or water can be used.

  Examples of water include water from which ionic impurities have been removed as much as possible, such as pure water such as ion exchange water, ultrafiltration water, reverse osmosis water, and distilled water, and ultrapure water. In addition, when water sterilized by ultraviolet irradiation or addition of hydrogen peroxide is used, generation of mold and bacteria can be prevented when the ink is stored for a long period of time. This tends to improve the storage stability.

Among organic solvents, volatile water-soluble organic solvents are more preferable. The organic solvent is not particularly limited, and specifically, glycerin, trimethylglycine, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol mono-n-propyl ether, ethylene glycol mono-iso- Propyl ether, diethylene glycol mono-iso-propyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol mono-t-butyl ether, diethylene glycol mono-n-butyl ether, triethyl Glycol monobutyl ether, diethylene glycol mono-t-butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-t-butyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-iso-propyl ether, propylene glycol Mono-n-butyl ether, dipropylene glycol mono-n-butyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-iso-propyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol ethyl methyl ether , Jiechire Glycol butyl methyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, tripropylene glycol dimethyl ether, methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, n-butanol, 2 Alcohols or glycols such as butanol, tert-butanol, iso-butanol, n-pentanol, 2-pentanol, 3-pentanol, and tert-pentanol, N, N-dimethylformamide, N, N- Dimethylacetamide, 2-pyrrolidone, N-methyl-2-pyrrolidone, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone, dimethyl Sulfoxide, sulfolane, and 1,1,3,3-tetramethylurea.

  A solvent may be used individually by 1 type and may be used in combination of 2 or more type. The addition amount of the organic solvent is not particularly limited, and can be appropriately determined as necessary. For example, in order to improve the permeability and moisture retention of the ink to the recording medium, at least one selected from the group consisting of glycerin, trimethylglycine, triethylene glycol monobutyl ether, and 2-pyrrolidone is used. It is preferable.

  The addition amount of the organic solvent is preferably 5% by mass or more and 25% by mass or less, more preferably 7.5% by mass or more and 20% by mass or less, and further preferably 10% by mass with respect to the total amount of the ink. The content is 15% by mass or less.

  Among these, as a solvent, it is preferable that triethylene glycol monobutyl ether is included, and it is preferable that the addition amount of triethylene glycol monobutyl ether is 2 times or more of the addition amount of polyoxyalkylene alkyl ether. The amount of triethylene glycol monobutyl ether added is preferably 2.0% by mass or more and 15% by mass or less, more preferably 2.5% by mass or more and 12.5% by mass or less, and further preferably 3. It is 0 mass% or more and 10 mass% or less. When the addition amount of triethylene glycol monobutyl ether is within the above range, continuous printing stability is improved.

1.9. pH adjuster The ink composition used in the present embodiment may contain a pH adjuster. The pH adjuster can easily adjust the pH value of the ink. Although it does not specifically limit as a pH adjuster, For example, inorganic acids (for example, sulfuric acid, hydrochloric acid, nitric acid, etc.), inorganic bases (for example, lithium hydroxide, sodium hydroxide, potassium hydroxide, ammonia, etc.), organic bases ( Triethanolamine, diethanolamine, monoethanolamine, tripropanolamine), organic acids (for example, adipic acid, citric acid, succinic acid, etc.) and the like. A pH adjuster may be used individually by 1 type, and may be used in mixture of 2 or more types.

1.10. Other components The ink composition according to the present embodiment is a dissolution aid for maintaining good storage stability and ejection stability from the head, for improving clogging, or for preventing ink deterioration, Various additives such as viscosity modifiers, pH adjusters, antioxidants, preservatives, antifungal agents, corrosion inhibitors, and chelating agents for capturing metal ions that affect dispersion are added as appropriate. You can also

1.11. Ink Preparation Method The ink composition according to this embodiment can be obtained by mixing the components described above in an arbitrary order, and removing impurities by filtering or the like as necessary. As a method for mixing the components, a method in which materials are sequentially added to a container equipped with a stirring device such as a mechanical stirrer or a magnetic stirrer and stirred and mixed is suitably used. As a filtration method, centrifugal filtration, filter filtration, or the like can be performed as necessary.

1.12. Ink properties according to the present embodiment are measured by using PCA-1 manufactured by Kyowa Interface Science as a measuring device and setting the amount of ink droplets to 0.5 μL at room temperature and humidity from the viewpoint of initial filling properties. When the interval is measured every 100 msec after the first dropping, and every 1000 msec after the first dropping, the dynamic contact angle with respect to the silicon wafer is 22 ° or less at 100 msec after dropping and 7 ° or less at 5100 msec after dropping. preferable. A small dynamic contact angle indicates that the wettability to the adhesion target is high. Therefore, when the dynamic contact angle is small, for example, in the flow path in the head made of silicon, air bubbles are filled without remaining when ink is filled, so that the ink ejection stability is improved. The dynamic contact angle is more preferably 20 ° or less at 100 msec after dropping and 5 ° or less at 5100 msec after dropping.

  In the ink composition according to the present embodiment, the surface tension at 20 ° C. is preferably 20 mN / m or more and 50 mN / m or more, and 25 mN / m or more, from the viewpoint of the balance between the recording quality and the reliability as an inkjet ink. More preferably, it is 40 mN / m or less. The surface tension is measured by using an automatic surface tension meter CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.) by confirming the surface tension when the platinum plate is wetted with ink in an environment of 20 ° C. be able to.

  From the same viewpoint, the viscosity at 20 ° C. of the ink composition according to this embodiment is preferably 1 mPa · s or more and 8 mPa · s or less, and more preferably 2 mPa · s or more and 6 mPa · s or less. . The viscosity can be measured using a vibration viscometer VM-100AL (manufactured by Yamaichi Electronics Co., Ltd.).

2. Ink Set The ink set according to the present embodiment is characterized by including at least one ink composition for inkjet recording described above.

  The ink composition according to the present embodiment is excellent in image fastness and color developability of the obtained recorded matter. Therefore, when printing is performed using an ink set including the ink composition, the image fastness and color developability are excellent. A record is obtained.

3. EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited only to these examples.

3.1. Preparation of ink composition Before performing various evaluations, an ink composition was first prepared. The main materials for the ink compositions used in the following Examples and Comparative Examples are as shown in Table 2 below.

  Each ink composition was obtained by mixing each component so that it may become a composition of Table 2, fully stirring, and also filtering with a membrane filter with a hole diameter of 5 micrometers. In Table 2, the unit of numerical values is mass%, and the total is 100.0 mass%.

The components used in Table 2 are as follows.
(1) First dye, Bk-1: see below (2) Second dye, Bk-2-a: see below, mixture of formulas (I) to (III), Bk-2-b: Projet First Black 2 (trade name, manufactured by LANXESS Co., Ltd.), see below for general formula (IV)
・ C. I. Direct Black 154 (manufactured by Daiwa Kasei Co., Ltd.)
・ C. I. Direct Black 168 (manufactured by Clariant Japan)
・ C. I. Acid Black 52
・ C. I. Reactive Black 39
・ C. I. Food Black 2 (Mitsubishi Chemical Corporation)
(3) Third dye Bw-1: See below

（上記式（Ｉ）中、Ｍはナトリウムである）

(In the above formula (I), M is sodium)

（上記式（ＩＩ）中、Ｍはナトリウムである）

(In the above formula (II), M is sodium)

（上記式（ＩＩＩ）中、Ｍはナトリウムである）

(In the above formula (III), M is sodium)

（上記式（ＩＶ）中、Ｍは水素原子、アルカリ金属、アンモニア、および有機アミン類からなる群から選択される基の陽イオンを表し、ｍは１または２を表し、ｎは０または１を表す。）

(In the above formula (IV), M represents a cation of a group selected from the group consisting of a hydrogen atom, an alkali metal, ammonia, and organic amines, m represents 1 or 2, and n represents 0 or 1) Represents.)

（４）界面活性剤
・親水性界面活性剤；製品名オルフィンＥ１０１０（製造元：エアープロダクツジャパン株式会社、販売元：信越化学工業株式会社、主鎖の炭素数が１２以上であるアセチレングリコールのアルキレンオキサイド付加物、ＨＬＢ値１３〜１４）
・親水性界面活性剤；製品名サーフィノール４６５（製造元：エアープロダクツジャパン株式会社、販売元：信越化学工業株式会社、主鎖の炭素数が１０のエチレンオキサイド付加物、ＨＬＢ値１３）
・疎水性界面活性剤；製品名サーフィノール１０４ＰＧ５０（製造元：エアープロダクツジャパン株式会社、販売元：信越化学工業株式会社、主鎖の炭素数１０以上のアセチレングリコール、ＨＬＢ値４）
（５）溶剤
ヘキサエチレングリコールモノエチルヘキシルエーテル；製品名ニューコール１００６（製造元：日本乳化剤株式会社、ポリオキシアルキレンアルキルエーテル）
ジプロピレングリコール−ｎ−プロピルエーテル
トリエチレングリコール
トリエチレングリコールモノブチルエーテル
グリセリン
（６）ｐＨ調整剤
トリエタノールアミン

(4) Surfactant / hydrophilic surfactant; Product name Olfine E1010 (Manufacturer: Air Products Japan, distributor: Shin-Etsu Chemical Co., Ltd., alkylene oxide of acetylene glycol having a main chain having 12 or more carbon atoms) Adduct, HLB value 13-14)
-Hydrophilic surfactant; product name Surfinol 465 (manufacturer: Air Products Japan Co., Ltd., distributor: Shin-Etsu Chemical Co., Ltd., ethylene oxide adduct having 10 main chain carbon atoms, HLB value 13)
Hydrophobic surfactant; product name Surfinol 104PG50 (manufacturer: Air Products Japan, distributor: Shin-Etsu Chemical Co., Ltd., acetylene glycol having 10 or more carbon atoms in the main chain, HLB value 4)
(5) Solvent Hexaethylene glycol monoethylhexyl ether; product name New Coal 1006 (manufacturer: Nippon Emulsifier Co., Ltd., polyoxyalkylene alkyl ether)
Dipropylene glycol-n-propyl ether Triethylene glycol Triethylene glycol monobutyl ether Glycerin (6) pH adjuster Triethanolamine

3.2. Evaluation of ink composition 3.2.1. Color development Inkjet printer (trade name “PM-A750”, manufactured by Seiko Epson Corporation), and further using the above ink, photo paper <gloss> (trade name, model number “KA4100PSKR”, manufactured by Seiko Epson Corporation) In addition, a printed matter is produced by solid printing with a resolution of 720 × 720 dpi and a duty of 50%, and a *, b * (L * a defined by CIE (International Lighting Commission)) of the image of the obtained recorded matter. * B * color system) was measured using a spectrophotometer i1 (trade name, manufactured by X-rite). Based on the obtained a * value and b * value, the hue was evaluated according to the following evaluation criteria.
(Evaluation criteria)
A: The a * value and the b * value are within 10.
B: At least one of the a * value and the b * value is greater than 10 and 20 or less.
C: At least one of the a * value and the b * value is greater than 20.

Note that “duty” is a value calculated by the following equation, and can be translated into a printing duty or a printing rate.
duty (%) = number of actual printing dots / (vertical resolution × horizontal resolution) × 100
(In the formula, “actual print dot number” is the actual print dot number per unit area, and “vertical resolution” and “horizontal resolution” are resolutions per unit area. Also, “duty 100%” is a unit. (This means the maximum ink weight of a single color per pixel.)

3.2.2. Gas resistance Using an ink jet printer (trade name “PM-A803”, manufactured by Seiko Epson Corporation) and further printing on photographic paper <gloss> using the above ink, resolution of 1440 × 1440 dpi, duty 100% A recorded matter of a solid pattern image was prepared and allowed to stand in a dark place at room temperature for 1 day. Thereafter, the evaluation sample was placed in an ozone weather meter OMS-L type (trade name, manufactured by Suga Test Instruments Co., Ltd.), and ozone was used for 40 hours under conditions of a temperature of 23 ° C., a relative humidity of 50% RH, and an ozone concentration of 5 ppm. An exposure test was conducted. The OD value (D0) before exposure and the OD value (D) after exposure of the image of the obtained recorded matter were measured using a spectrophotometer i1 (trade name, manufactured by X-rite), and optically calculated by the following formula. A concentration residual ratio (ROD) was determined, and gas resistance was evaluated according to the following criteria. The determination was made based on ROD at 4 points of around 2.0, 1.5, 1.0, and 0.5 where the OD concentration was maximum.
ROD (%) = (D / D0) × 100
(Evaluation criteria)
A: ROD does not decrease to 70% by 80 hours.
B: ROD decreases to 70% over 60 hours and 80 hours or less.
C: ROD decreases to 70% over 40 hours and 60 hours or less.

3.2.3. By using an ink jet printer (trade name “PM-A805A”, manufactured by Seiko Epson Corporation) and further printing on photographic paper <gloss> using the above ink, a solid of resolution 1440 × 1440 dpi and duty 100% is obtained. A recorded pattern image was prepared and allowed to stand in a dark place at room temperature for 1 day. After that, the recorded matter was placed in a Xenon light resistance tester XL-75s (trade name: manufactured by Suga Test Instruments Co., Ltd.), and exposed for 30 days under conditions of a temperature of 23 ° C., a relative humidity of 50% RH, and an illuminance of 75 klux. Went. The OD value (D0) before exposure and the OD value (D) after exposure of the image of the obtained recorded matter were measured using a spectrophotometer i1 (trade name, manufactured by X-rite), and optically calculated by the following formula. A concentration residual ratio (ROD) was determined, and light resistance was evaluated according to the following criteria. The determination was made based on ROD at 4 points of around 2.0, 1.5, 1.0, and 0.5 where the OD concentration was maximum.
ROD (%) = (D / D0) × 100
(Evaluation criteria)
A: ROD does not decrease to 70% by 18 days.
B: ROD decreases to 70% over 12 days and 18 days or less.
C: ROD decreases to 70% over 6 days and 12 days or less.

3.2.4. Initial fillability 3.2.3. The ink tank of the ink jet printer used for the light resistance was filled. According to the initial filling sequence, the initial filling operation to the head was performed. Thereafter, a nozzle check was performed to confirm whether ink could be ejected from all nozzles of the head. When there was a nozzle that could not eject ink, the head was cleaned (suction of ink in the nozzle), and then the nozzle check was performed again. Based on the number of cleanings required until ink can be ejected from all nozzles, the initial filling property was evaluated according to the following evaluation criteria.
(Evaluation criteria)
A: Normal discharge is performed from all nozzles only in the initial filling sequence.
B: The number of cleanings required until ink can be ejected from all nozzles is one.
C: The number of cleanings required until ink can be ejected from all nozzles is 2 or more.

3.2.5. Continuous printing stability After confirming that ink can be ejected from all nozzles of the head by evaluating the initial filling property, the head idle time of 40 seconds + ink idle driving (flushing) under conditions of a temperature of 40 ° C. and a relative humidity of 25% RH ) Was repeated 5 times, and then two ruled lines were printed on the photographic paper <glossy>. The obtained printed matter was visually confirmed, and the continuous printing stability was evaluated according to the following criteria.
(Evaluation criteria)
A: The ruled lines are printed normally for both the first and second lines.
B: The first ruled line is not printed normally.

3.2.6. PCA-1 manufactured by Kyowa Interface Science was used as a dynamic contact angle measuring device, the ink droplet volume was set to 0.5 μL at room temperature and normal humidity, and the dynamic contact angle with respect to the silicon wafer was measured at 100 msec and 5100 msec after dropping. .

3.2.7. Evaluation results The results of the above evaluation tests are as shown in Table 2 above. The ink according to the example contains the first dye and the second dye in a predetermined ratio, so that the obtained recorded matter is excellent in image fastness (gas resistance and light resistance) and color developability, and is initially The filling property and continuous printing stability were also excellent. In particular, in Example 11 in which the third dye was also added, all evaluations were A. In Example 12, since the addition amount of triethylene glycol monobutyl ether was less than twice the addition amount of polyoxyalkylene alkyl ether, ejection failure due to surfactant separation at the inkjet head nozzle occurred, and continuous printing stability Was inferior to the others.

On the other hand, in Comparative Example 1 in which the composition ratio of the first dye and the second dye was 5: 5, the image fastness was inferior, and in Comparative Example 2 not containing the second dye, The result was inferior in color development. In Comparative Examples 3 and 5 that do not contain an alkylene oxide adduct of acetylene glycol having a main chain having 12 or more carbon atoms and an acetylene glycol having 10 or more carbon atoms in the main chain, color developability and image fastness As a result, the initial filling property was inferior. Similarly, Comparative Example 4 containing no polyoxyalkylene alkyl ether also resulted in poor color development, image fastness and initial filling property. Furthermore, Comparative Example 6 not containing acetylene glycol having 10 or more carbon atoms in the main chain also resulted in inferior color development, image fastness and initial filling properties. In Comparative Examples 3 to 6, the value of the dynamic contact angle is large and the wettability to the ink jet flow path member is insufficient, so that the initial filling property is inferior due to bubbles remaining in the ink. I think that the.

  The present invention is not limited to the embodiments described above, and various modifications are possible. For example, the present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same objects and effects). In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that exhibits the same operational effects as the configuration described in the embodiment or a configuration that can achieve the same object. In addition, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

Claims (7)

As a dye, a first dye represented by the following formula (Bk-1), and a black second dye other than the first dye,
The composition ratio of the first dye and the second dye is 8: 2 to 9: 1;
The total addition amount of the first dye and the second dye is 3.0% by mass or more and 5.0% by mass or less,
An ink composition for inkjet recording, comprising an alkylene oxide adduct of acetylene glycol having a main chain having 12 or more carbon atoms, an acetylene glycol having a main chain having 10 or more carbon atoms, and a polyoxyalkylene alkyl ether.

(In formula (Bk-1), R ¹ , R ² , R ⁵ , R ⁶ and R ⁷ are each independently a hydrogen atom, halogen atom, cyano group, hydroxyl group, carboxyl group, sulfo group, sulfamoyl group, N -Alkylaminosulfonyl group, N-phenylaminosulfonyl group, alkylsulfonyl group having 1 to 4 carbon atoms which may be substituted with hydroxyl group, phospho group, nitro group, acyl group, ureido group, 1 to 4 carbon atoms An alkyl group (which may be substituted with a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms), an alkoxy group having 1 to 4 carbon atoms (the alkyl group is a hydroxyl group, an alkoxy group having 1 to 4 carbon atoms) Which may be substituted with a sulfo group or a carboxyl group), an acylamino group, an alkylsulfonylamino group, or a phenylsulfonyl group. Amino group (the phenyl group a halogen atom, an alkyl group or may be substituted by nitro group) to, R ³ and R ⁴ are each independently hydrogen atom, a halogen atom, a cyano group, a carboxyl group, a sulfo group, a nitro Group, an alkyl group having 1 to 4 carbon atoms (which may be substituted with a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms), an alkoxy group having 1 to 4 carbon atoms (an alkyl group is a hydroxyl group, a carbon atom) 1 to 4 or less alkoxy groups, which may be substituted with an alkoxy group, a sulfo group or a carboxyl group), an acylamino group, an alkylsulfonylamino group or a phenylsulfonylamino group (the phenyl group is substituted with a halogen atom, an alkyl group or a nitro group) And n represents 0 or 1 respectively.) In claim 1,
An ink composition for ink jet recording, wherein the amount of the second dye added is 0.1% by mass or more and 2.0% by mass or less. In claim 1 or claim 2,
The second dye is C.I. I. Direct black 154, C.I. I. Direct black 168, C.I. I. Acid Black 52, C.I. I. Reactive Black 39, C.I. I. An ink composition for ink jet recording, which is at least one selected from the group consisting of Food Black 2 and compounds represented by the following general formulas (I) to (IV).

(In the above formula (I), each M is independently a hydrogen atom or an alkali metal)

(In the above formula (II), each M is independently a hydrogen atom or an alkali metal)

(In the above formula (III), each M is independently a hydrogen atom or an alkali metal)

(In the above formula (IV), M represents a cation of a group selected from the group consisting of a hydrogen atom, an alkali metal, ammonia, and organic amines, m represents 1 or 2, and n represents 0 or 1) Represents.) In any one of Claims 1 to 3,
Furthermore, a third dye represented by the following formula (Bw-1) is included,
An ink composition for ink jet recording, wherein the amount of the third dye added is 0.5% by mass or more and 1.5% by mass or less.

(In the formula (Bw-1), R ²¹ , R ²² , R ²³ , R ²⁴ , R ²⁵ , R ²⁶ , R ²⁷ and R ²⁸ are each independently a hydrogen atom; a halogen atom; a sulfo group; a carboxy group. A sulfamoyl group, a carbamoyl group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a hydroxy group, an alkoxy group having 1 to 4 carbon atoms, and a hydroxy-carbon number of 1 or more. An alkoxy group having 1 to 4 carbon atoms substituted with at least one group selected from the group consisting of an alkoxy group having 4 or less alkoxy groups, a sulfo group, and a carboxy group; an alkylcarbonylamino group having 1 to 4 carbon atoms; An alkylcarbonylamino group having 1 to 4 carbon atoms substituted with a carboxy group; a ureido group; an alkylureido group having 1 to 4 monocarbons; a dicarbon An alkylureido group having 1 or more and 4 or less; an alkylureido group having 1 to 4 monocarbons substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group, and a carboxy group as a substituent; As a substituent, an alkylureido group having 1 to 4 dicarbon atoms substituted with at least one group selected from the group consisting of a hydroxy group, a sulfo group, and a carboxy group; a benzoylamino group; A benzoylamino group substituted with at least one group selected from the group consisting of an atom, an alkyl group having 1 to 4 carbon atoms, a nitro group, a sulfo group, and a carboxy group; a benzenesulfonylamino group; or a benzene ring From a halogen atom, an alkyl group having 1 to 4 carbon atoms, a nitro group, a sulfo group, and a carboxy group A phenylsulfonylamino group substituted with at least one group selected from the group consisting of:
X represents a divalent crosslinking group. ) In any one of Claims 1 thru | or 4,
In addition, triethylene glycol monobutyl ether as a solvent,
An ink composition for ink jet recording, wherein the addition amount of the triethylene glycol monobutyl ether is at least twice the addition amount of the polyoxyalkylene alkyl ether. In any one of Claims 1 thru | or 5,
An ink composition for ink jet recording, wherein a dynamic contact angle with respect to a silicon wafer is 22 ° or less at 100 msec after dropping and 7 ° or less at 5100 msec after dropping.   An ink set comprising the ink composition for ink jet recording according to any one of claims 1 to 6.