JP2004196863A - Recording liquid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording liquid affording sharp prints when recorded on plain paper and exclusive paper for aqueous ink-jet recording and having excellent recorded image density, light and indoor discoloration resistances, etc. <P>SOLUTION: The recording liquid is characterized as comprising an aqueous medium and at least one kind of dye selected from a monoazo dye in the form of a free acid represented by general formula (1) [wherein, R<SB>1</SB>, R<SB>2</SB>and R<SB>3</SB>denote each independently a hydrogen atom, a halogen atom or the like; m denotes a number of 0, 1 or 2; R<SB>4</SB>denotes a hydrogen atom or a 1-9C substituted or unsubstituted alkyl group; R<SB>5</SB>denotes a hydrogen atom, a 1-18C substituted or unsubstituted alkyl group or the like; and Z denotes a group represented by general formula (2) or general formula (3)]. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００８】
（式中、Ｒ₁、Ｒ₂及びＲ₃は、それぞれ独立に、水素原子、ハロゲン原子、ヒドロキシル基、ニトロ基、ＣＯＯＨ基、炭素数１〜９の置換もしくは非置換のアルキル基、炭素数１〜９の置換もしくは非置換のアルコキシ基、置換もしくは非置換のカルバモイル基、置換もしくは非置換のスルファモイル基、置換もしくは非置換のアミノ基、炭素数１〜９の置換もしくは非置換のアルキルスルホニル基、炭素数６〜１５の置換もしくは非置換のアリールスルホニル基、スルホン酸エステル基又はカルボン酸エステル基を示し、
ｍは０、１又は２の数を示し、
Ｒ₄は、水素原子又は炭素数１〜９の置換もしくは非置換のアルキル基を示し、
Ｒ₅は、水素原子、炭素数１〜１８の置換もしくは非置換のアルキル基、炭素数２〜１８の置換もしくは非置換のアルケニル基、置換もしくは非置換のアリール基、置換もしくは非置換のアリサイクリック基又は置換もしくは非置換のヘテロサイクリック基を示し、
Ｚは下記一般式（２）
【０００９】
【化８】

【００１０】
（式中、Ｒ₆、Ｒ₇及びＲ₈は、それぞれ独立して、水素原子、ハロゲン原子、ヒドロキシル基、ニトロ基、ＣＯＯＨ基、炭素数１〜９の置換もしくは非置換のアルキル基、炭素数１〜９の置換もしくは非置換のアルコキシ基、置換もしくは非置換のカルバモイル基、置換もしくは非置換のスルファモイル基、置換アミノ基、スルホン酸エステル基又はカルボン酸エステル基を示し、ｎは１又は２を示す。ここで、ｎが１の場合にはスルホン酸基はパラ位に位置する。）又は下記一般式（３）
【００１１】
【化９】

【００１２】
（式中、Ｒ₉、Ｒ₁₀及びＲ₁₁は、それぞれ独立して、水素原子、ヒドロキシル基、ニトロ基、ＣＯＯＨ基又は置換もしくは非置換のアミノ基を示し、ｐは２又は３の整数を示す。）で表される基を示す。）
以下本発明を詳細に説明する。
【００１３】
【発明の実施の形態】
本発明で使用される色素は、遊離酸の形が上記一般式（１）で表されるものである。
上記一般式（１）において、Ｒ₁、Ｒ₂及びＲ₃は、それぞれ独立に、水素原子；フッ素原子、塩素原子、臭素原子等のハロゲン原子；ヒドロキシル基；ニトロ基；ＣＯＯＨ基；炭素数１〜９の置換もしくは非置換のアルキル基；炭素数１〜９の置換もしくは非置換のアルコキシ基；置換もしくは非置換のカルバモイル基；置換もしくは非置換のスルファモイル基；置換もしくは非置換のアミノ基；炭素数１〜９の置換もしくは非置換のアルキルスルホニル基；炭素数６〜１５の置換もしくは非置換のアリールスルホニル基；スルホン酸エステル基又はカルボン酸エステル基である。
【００１４】
ここで、炭素数１〜９の置換もしくは非置換のアルキル基としては、メチル基、エチル基、ｎ−プロピル基、イソプロピル基、ｎ−ブチル基、トリフルオロメチル基、ジメチルアミノメチル基等のハロゲン原子及びアミノ基からなる群より選ばれる置換基で置換されていてもよいアルキル基が挙げられ、このうち好ましくは炭素数１〜４のものであり、特に好ましくは炭素数１〜４のハロアルキル基であり、特に好ましくはトリフルオロメチル基である。
【００１５】
炭素数１〜９の置換もしくは非置換のアルコキシ基としては、メトキシ基、エトキシ基、イソプロポキシ基、ｎ−ブトキシ基、ヒドロキシエトキシ基等の水酸基で置換されていても良いアルコキシ基が挙げられ、このうち好ましくは炭素数１〜４のものであり、より好ましくは無置換の炭素数１〜４のアルコキシ基であり、特に好ましくはメトキシ基である。
【００１６】
置換もしくは非置換のカルバモイル基としては、カルバモイル基、Ｎ，Ｎ−ジメチルカルバモイル基、フェニルカルバモイル基等のアルキル基及びアリール基からなる群より選ばれる置換基で置換されていても良いカルバモイル基が挙げられ、このうち好ましくはカルバモイル基である。
置換もしくは非置換のスルファモイル基としては、スルファモイル基、Ｎ−メチルスルファモイル基、Ｎ−エチルスルファモイル基、Ｎ−エチル−Ｎ−フェニルスルファモイル基、Ｎ，Ｎ−ジメチルスルファモイル基、ｐ−カルボキシフェニルスルファモイル基等のアルキル基及びアリール基からなる群より選ばれる置換基で置換されていても良いスルファモイル基が挙げられ、このうち好ましくはスルファモイル基である。
【００１７】
置換もしくは非置換のアミノ基としては、Ｎ−メチルアミノ基、Ｎ，Ｎ−ジメチルアミノ基、Ｎ，Ｎ−ジエチルアミノ基、フェニルアミノ基、カルバモイルアミノ基、アセチルアミノ基等のアルキル基、アリール基、カルバモイル基及びアシル基からなる群より選ばれる置換基で置換されていても良いアミノ基が挙げられ、このうち好ましくはアシルアミノ基であり、特に好ましくはアセチルアミノ基である。
【００１８】
炭素数１〜９の置換もしくは非置換のアルキルスルホニル基としては、メチルスルホニル基、ヒドロキシエチルスルホニル基、ベンジルスルホニル基等の水酸基及びアリール基からなる群より選ばれる置換基で置換されていても良い炭素数１〜９のアルキルスルホニル基が挙げられ、このうち好ましくは炭素数１〜４のものであり、より好ましくは炭素数１〜４の無置換のアルキルスルホニル基であり、特に好ましくはメチルスルホニル基である。
【００１９】
炭素数６〜１５の置換もしくは非置換のアリールスルホニル基としては、フェニルスルホニル基、トリルスルホニル基等のアルキル基で置換されていても良いアリールスルホニル基が挙げられ、このうち好ましくはフェニルスルホニル基である
スルホン酸エステル基としては、メトキシスルホニル基、エトキシスルホニル基等のアルコキシスルホニル基又はフェノキシスルホニル基等のアリールオキシスルホニル基が挙げられ、このうち好ましくは炭素数１〜６のアルコキシスルホニル基、ベンジルオキシスルホニル基又はフェニルスルホニル基であり、より好ましくは炭素数１〜４のアルコキシスルホニル基である。
【００２０】
カルボン酸エステル基としては、メトキシカルボニル基、エトキシカルボニル基等のアルコキシカルボニル基又はフェノキシカルボニル基等のアリールオキシカルボニル基が挙げられ、このうち好ましくは炭素数１〜６のアルコキシカルボニル基、ベンジルオキシカルボニル基又はフェノキシカルボニル基であり、より好ましくは炭素数１〜４のアルコキシカルボニル基であり、特に好ましくはメトキシカルボニル基である。
【００２１】
このうち好ましくは、水素原子、ハロゲン原子、ＣＯＯＨ基、トリフルオロメチル基、置換もしくは非置換のカルバモイル基、置換もしくは非置換のスルファモイル基、スルホン酸の炭素数１〜４のアルキルエステル基又はカルボン酸の炭素数１〜４のアルキルエステル基である。
また、上記Ｒ₁〜Ｒ₃の好ましい置換基の組み合わせとしては、少なくとも１つが水素原子の場合であり、さらに上記Ｒ₁〜Ｒ₃のうちの少なくとも１つがＣＯＯＨ基、トリフルオロメチル基、置換もしくは非置換のカルバモイル基、置換もしくは非置換のスルファモイル基、スルホン酸の炭素数１〜４のアルキルエステル基及びカルボン酸の炭素数１〜４のアルキルエステル基からなる群より選ばれる置換基であり、その置換位置がアゾ基に対してオルト位であるものが好ましく、特にはＲ₁〜Ｒ₃のうちの２つがハロゲン原子とＣＯＯＨ基との組み合わせであることが好ましい。
【００２２】
ｍは０〜２の整数であり、このうち好ましくは０又は１である。
Ｒ₄は、水素原子又は炭素数１〜９の置換もしくは非置換のアルキル基であり、上記炭素数１〜９の置換もしくは非置換のアルキル基としては、Ｒ₁〜Ｒ₃の説明の項で例示したのと同様の基を挙げることができる。
このうち、Ｒ₄としては、水素原子が好ましい。
【００２３】
Ｒ₅は、水素原子、炭素数１〜１８の置換もしくは非置換のアルキル基、炭素数２〜１８の置換もしくは非置換のアルケニル基、置換もしくは非置換のアリール基、置換もしくは非置換のアリサイクリック基又は置換もしくは非置換のヘテロサイクリック基である。
上記炭素数１〜１８の置換もしくは非置換のアルキル基としては、メチル基、エチル基、ｎ−ブチル基、ｎ−オクチル基、エチルヘキシル基、ヒドロキシエチル基、カルボキシプロピル基、カルボキシシクロヘキシルメチル基、１−カルボキシ−２−メルカプトエチル基、１−カルボキシ−２−カルバモイル−エチル基、１−イソプロピル−１−カルボキシメチル基、１，２−ジカルボキシプロピル基、ベンジル基、１−カルボキシ−２−フェニル−エチル基、１−カルボキシ−２−ヒドロキシフェニルエチル基、４−カルボキシベンジル基等の水酸基、カルボキシル基、メルカプト基、カルバモイル基、アリサイクリック基及びアリール基からなる群より選ばれる置換基で置換されていても良いアルキル基（ここで前記アリサイクリック基及びアリール基はさらに水酸基、カルボキシル基又はアルキル基で置換されていても良い。）が挙げられ、このうち好ましくは無置換の炭素数１〜４のアルキル基であり、特に好ましくはメチル基である。
【００２４】
炭素数２〜１８の置換もしくは非置換のアルケニル基としては、２−メチル−１−プロペニル基、ビニル基、アリル基等のアルキル基で置換されていても良いアルケニル基が挙げられ、このうち好ましくは炭素数４以下のものであり、特に好ましくはビニル基である。
アリール基としては、フェニル基、３，４−ジカルボキシフェニル基、４−ブチルフェニル基、４−カルボキシフェニル基等の水酸基、アルキル基及びカルボキシル基からなる群より選ばれる置換基で置換されていても良いフェニル基又はナフチル基が挙げられ、このうち好ましくはアルキル基及びカルボキシル基群より選ばれる置換基で置換されていても良いフェニル基又はナフチル基であり、特に好ましくはフェニル基である。
【００２５】
アリサイクリック基としては、シクロヘキシル基、４−カルボキシシクロヘキシル基等のカルボキシル基で置換されていても良い炭素数６〜１０のものが挙げられ、このうち好ましくはシクロヘキシル基である。
ヘテロサイクリック基としては、ピリジル基、チアジアゾリル基、ベンゾチアゾリル基、２，２，６，６−テトラメチルピペリジニル基等の炭素数１０以下のものが挙げられ、このうち好ましくは少なくともヘテロ原子として窒素原子を１又は２個有する含窒素複素環が挙げられ、特には５〜６員の含窒素複素環が挙げられ、このうち好ましくはピリジル基である。
【００２６】
このうち、Ｒ₅としては、水素原子、アルキル基又はアリール基が好ましく、特に好ましくは水素原子である。
Ｚは、上記一般式（２）又は（３）で表される基である。
一般式（２）で表される基において、Ｒ₆、Ｒ₇及びＲ₈は、それぞれ独立して、水素原子；フッ素原子、塩素原子、臭素原子等のハロゲン原子；ヒドロキシル基；ニトロ基；ＣＯＯＨ基；炭素数１〜９の置換もしくは非置換のアルキル基；炭素数１〜９の置換もしくは非置換のアルコキシ基；置換もしくは非置換のカルバモイル基；置換もしくは非置換のスルファモイル基；置換アミノ基；スルホン酸エステル基又はカルボン酸エステル基であり、このうち水素原子、ハロゲン原子、ヒドロキシル基、ニトロ基、ＣＯＯＨ基、炭素数１〜９の置換もしくは非置換のアルキル基、炭素数１〜９の置換もしくは非置換のアルコキシ基、置換もしくは非置換のカルバモイル基、置換もしくは非置換のスルファモイル基、スルホン酸エステル基又はカルボン酸エステル基が好ましい。
【００２７】
ここで、炭素数１〜９の置換もしくは非置換のアルキル基；炭素数１〜９の置換もしくは非置換のアルコキシ基；置換もしくは非置換のカルバモイル基；置換もしくは非置換のスルファモイル基；スルホン酸エステル基及びカルボン酸エステル基としては、上記Ｒ₁〜Ｒ₃の説明の部分で挙げられたのと同様の基を挙げることができ、置換アミノ基としては、Ｎ−メチルアミノ基、Ｎ，Ｎ−ジメチルアミノ基、Ｎ，Ｎ−ジエチルアミノ基、フェニルアミノ基、カルバモイルアミノ基、アセチルアミノ基トリアジニルアミノ基等のアルキル基、アリール基、カルバモイル基、アシル基及びヘテロ環基からなる群より選ばれる置換基で置換されていても良いアミノ基が挙げられる。
【００２８】
ｎは１又は２であり、ここでｎが１の場合には、スルホン酸基はパラ位に位置するものである。
上記一般式（３）において、Ｒ₉、Ｒ₁₀及びＲ₁₁は、それぞれ独立して、水素原子、ヒドロキシル基、ニトロ基、ＣＯＯＨ基又は置換もしくは非置換のアミノ基であり、ここで、置換もしくは非置換のアミノ基としては、上記Ｒ₁〜Ｒ₃の説明の部分で挙げられたのと同様の基を挙げることができる。
【００２９】
ｐは２又は３の整数を示し、好ましくは２である。
また、本発明で使用される上記一般式（１）で表される色素は構造中に、ＳＯ₃Ｈ基及びＣＯＯＨ基、並びに、これらの酸の塩の基を合計で少なくとも３個以上有するのが好ましく、また８個以下、好ましくは５個以下有するものが好ましい。
【００３０】
特には、スルホン酸基及び／又はその塩としては３又は４個、カルボキシル基及び／又はその塩として１又は２個有するものが好ましい。
本発明で使用される色素は一般式（１）で示されるような遊離酸型のまま使用してもよく、また、製造時に塩型で得られた場合はそのまま使用してもよいし、所望の塩型に変換してもよい。塩型の交換方法としては、公知の方法を任意に用いることができ、例えば以下の方法が挙げられる。
１） 塩型で得られた色素の水溶液に塩酸等の強酸を添加し、色素を遊離酸の形で酸析せしめたのち、所望の対イオンを有するアルカリ溶液（例えば水酸化リチウム水溶液）で色素酸性基を中和し塩交換する方法。
２） 塩型で得られたの色素の水溶液に、所望の対イオンを有する大過剰の中性塩（例えば、塩化リチウム）を添加し、塩析ケーキの形で塩交換を行う方法。
３） 塩型で得られた色素の水溶液を、強酸性イオン交換樹脂で処理し、色素を遊離酸の形で酸析せしめたのち、所望の対イオンを有するアルカリ溶液（例えば水酸化リチウム水溶液）で色素酸性基を中和し塩交換する方法。
４） 予め所望の対イオンを有するアルカリ溶液（例えば水酸化リチウム水溶液）で処理した強酸性イオン交換樹脂に、塩型で得られた色素の水溶液を作用させ、塩交換を行う方法。
【００３１】
また、本発明で使用される色素は、酸基の一部が塩型を取っているものであってもよく、塩型の色素と遊離酸型の色素が混在していてもよい。ここで、酸性基が遊離酸型をとるか、塩型を取るかは、色素のｐＫａとインクのｐＨに依存するが、通常、スルホン酸基が塩型を取り、カルボキシル基よりも多く塩型になっている方が、インクの目詰まりしにくさの点では好ましい。他方、カルボキシル基が酸型を取っている色素は、耐水性や耐滲み性を重視する場合に好ましく使用される。
【００３２】
本発明に用いられる色素は、ｐＨ２〜１２、好ましくはｐＨ２〜１０、より好ましくはｐＨ３〜９．５で用いられ、特に酸性インクとした場合にも優れた性能を示すものである。
上記の塩型の例としては、Ｎａ、Ｌｉ、Ｋ等のアルカリ金属の塩、アルキル基もしくはヒドロキシアルキル基で置換されていてもよいアンモニウムの塩、又は有機アミンの塩が挙げられる。有機アミンの例として、炭素数１〜６の低級アルキルアミン、ヒドロキシ置換された炭素数１〜６の低級アルキルアミン、カルボキシ置換された炭素数１〜６の低級アルキルアミン及び炭素数２〜４のアルキレンイミン単位を２〜１０個有するポリアミン等が挙げられる。これらの塩型の場合、その種類は１種類に限られず複数種混在していてもよい。
【００３３】
塩型を構成する対イオンの種類の選択についても、そのインクにおいて重視すべき特性に応じ、自由に選択される。色素の合成に用いられる中間体や試薬にＮａを含むものが多いので、一般にＮａ塩の形で得られるものが多いが、耐水性を重視する場合はＮＨ₄塩に変換されることが多く、また色素の溶解性を高めインクの目詰まり性をより高いレベルに維持する必要があるときなどは、Ｌｉ塩や、トリエタノールアミンに代表されるアルカノールアミン塩の形に変換されることもある。
【００３４】
これ等の色素の具体例としては、例えば以下のＮｏ．１−２３に示す構造の色素が挙げられる。
【００３５】
【化１０】

【００３６】
【化１１】

【００３７】
【化１２】

【００３８】
【化１３】

【００３９】
【化１４】

【００４０】
上記一般式（１）で表されるモノアゾ色素は、それ自体周知の方法に従って製造することができる。例えばＮｏ．（１）で示される色素は、下記（Ａ）〜（Ｃ）の工程で製造できる。
（Ａ）２−アミノ安息香酸（アントラニル酸）と１−アミノ−８−ヒドロキシ−３，６−ナフタレンジスルホン酸（Ｈ酸）とから常法［例えば、細田豊著「新染料化学」（昭和４８年１２月２１日、技報堂発行）第３９６頁第４０９頁参照］に従って、ジアゾ化、カップリング工程を経てモノアゾ化合物を製造する。
（Ｂ）得られたモノアゾ化合物を塩化シアヌル懸濁液にｐＨ４〜６、温度０〜５℃を保持しながら加えて、数時間反応を行う。次いで室温にてアルカリ性にならない様に、４−アミノベンゼンスルホン酸（スルファニル酸）水溶液を加えて数時間縮合反応を行う。次いで、２５％水酸化ナトリウム水溶液を５０〜６０℃にて加え、強アルカリ性とし、加水分解反応を行い、反応を完結させる。
（Ｃ）冷却後、塩化ナトリウムで塩析することにより目的の色素Ｎｏ．（１）が得られる。
【００４１】
記録液中における前記一般式（１）の色素の含有量としては、記録液全量に対して０．５〜５重量％、特に２〜４重量％程度が好ましい。
本発明に用いられる溶剤としては、水及び水溶性有機溶剤として、例えばエチレングリコール、プロピレングリコール、ブチレングリコール、ジエチレングリコール、トリエチレングリコール、ポリエチレングリコール（＃２００）、ポリエチレングリコール（＃４００）、グリセリン、Ｎ−メチルピロリドン、Ｎ−エチルピロリドン、１，３−ジメチルイミダゾリジノン、チオジエタノール、ジメチルスルホキシド、エチレングリコールモノアリルエーテル、エチレングリコールモノメチルエーテル、ジエチレングリコールモノメチルエーテル、２−ピロリドン、スルホラン、エチルアルコール、イソプロパノール等を含有しているのが好ましい。これ等の水溶性有機溶剤は、通常記録液の全量に対して１〜５０重量％の範囲で使用される。一方、水は記録液の全量に対して４５〜９５重量％の範囲で使用される。
【００４２】
本発明の記録液に、その全量に対して０．１〜１０重量％、好ましくは０．５〜５重量％の尿素、チオ尿素、ビウレット、セミカルバジドから選ばれる化合物を添加したり、又０．００１〜５．０重量％の界面活性剤を添加することによって、印字後の速乾性及び印字品位をより一層改良することができる。
【００４３】
【実施例】
以下本発明について実施例をあげて更に詳細に説明するが、本発明はその要旨を越えない限りこれ等の実施例に限定されるものではない。
〔実施例１〕
ジエチレングリコール１０重量部、ジエチレングリコールモノブチルエーテル３重量部、前記Ｎｏ．１の色素３重量部に水を加え、１０％苛性ソーダ水溶液でｐＨを９に調整して全量を１００重量部とした。この組成物を充分に混合して溶解し、孔径１μｍのポリテトラフルオロエチレン製のフィルターで加圧濾過した後、真空ポンプ及び超音波洗浄機で脱気処理して記録液を調整した。
【００４４】
得られた記録液を使用し、インクジェットプリンター（商品名ＰＭ−７５０Ｃ、セイコーエプソン社製）を用いて、電子写真用紙（商品名「４０２４紙」ゼロックス社製）、スーパーファイン専用紙（商品名「ＭＪＡ４ＳＰ１」セイコーエプソン社製）、ＰＭマット紙（商品名「ＫＡ４５０ＰＭ」セイコーエプソン社製）及びＰＭ写真用紙（光沢）（商品名「ＫＡ４２０ＰＳＫ」セイコーエプソン社製）に各々インクジェット記録を行い、鮮明なマゼンタ色印字物を得た。
得られた印刷物及び記録液について、下記の各種試験を行った。結果を表１に示す。
【００４５】
［耐光性試験］
印字物にキセノンフェードメーター（アトラス社製）を用いて８０時間光照射した後の変褪色を観察した。試験前後の色調をグレタグマクベスＳＰＭ５０（グレタグマクベス社製）を用いて測定し、Ｌ^*ａ^*ｂ^*値を得た後、下記計算式（式中、Ｌ^* ₁、ａ^* ₁及びｂ^* ₁は耐光性試験前の色調測定から求められる値であり、Ｌ^* ₂、ａ^* ₂及びｂ^* ₂は耐光性試験後の色調測定から求められる値である。）により△Ｅ値を求めた。尚、△Ｅ値は小さいほど変褪色の度合いが低いことを示す。
【００４６】
【数１】

【００４７】
［耐室内変褪色試験］
遮光されたオゾン濃度１０ｐｐｍの槽内に印字物を４時間放置した後の変褪色を観察し、上記と同様にして△Ｅ値を求めた。
［印字品位試験］
印字物の彩度をグレタグマクベスＳＰＭ５０（グレタグマクベス社製）で測定し、いずれも高彩度であることを確認した。
【００４８】
［記録液の保存安定性試験］
記録液をポリテトラフルオロエチレン製容器に密閉し、５℃及び６０℃でそれぞれ１ケ月間保存した後の変化を調べた。
実施例２〜６
実施例１において前記Ｎｏ．１の色素の代わりに、表１に示す色素をそれぞれ使用した以外は同様にして記録液を調整し、印字を行ったところ、いずれの場合も鮮明な色調のマゼンダ色印字物を得た。
【００４９】
得られた印字物及び記録液について、実施例１と同様にして各種試験を行った。結果を表１に示す。
比較例１
実施例１において前記Ｎｏ．１の色素の代わりに、特開平８−７３７９１号公報に記載のＮｏ．１の色素を使用した以外は同様にして記録液を調整し、印字を行ったところ、鮮明な色調のマゼンダ色印字物を得た。
【００５０】
得られた印字物及び記録液について、実施例１と同様にして各種試験を行った。結果を表１に示す。
比較例２
実施例１において前記Ｎｏ．１の色素の代わりに、特開平１１−２７９４６９号公報に記載のＮｏ．２の色素を使用した以外は同様にして記録液を調整し、印字を行ったところ、鮮明な色調のマゼンダ色印字物を得た。
【００５１】
得られた印字物及び記録液について、実施例１と同様にして各種試験を行った。結果を表１に示す。
【００５２】
【表１】

【００５３】
【発明の効果】
本発明のインクジェット記録用色素は水溶解性に優れ、この色素を用いた本発明の記録液は、水系インクジェット記録用として、普通紙及び専用紙に記録した場合にも鮮明な印字物を得ることができる上に、その記録画像の濃度が高く、耐光性や耐室内変褪色性が優れており、長期間保存した場合の安定性も良好なものである。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a recording liquid. More specifically, the present invention relates to a recording liquid suitable for inkjet recording.
[0002]
[Prior art]
A so-called ink jet recording method has been put to practical use, in which droplets of a recording liquid containing a water-soluble dye such as a direct dye or an acid dye are fly from a minute ejection orifice to perform recording.
This recording liquid can be quickly fixed to recording paper generally used for general office work such as electrophotographic paper such as PPC (plain paper copier) paper and fan hold paper (continuous paper such as a computer), and furthermore, the print quality of printed matter. Is good, that is, it is required that the print has no blur and the outline is clear, and that the stability during storage as a recording liquid must be excellent. Limited.
[0003]
On the other hand, dyes for recording liquids have sufficient solubility in the limited solvents as described above, are stable even when stored as recording liquids for a long time, and have a density of printed images. Are required to be high in water resistance and light resistance, and various dyes have been studied for the purpose of simultaneously satisfying many of these requirements. Among them, a recording liquid using a 1-amino-8-naphthol-3,6-disulfonic acid (H acid) monoazo dye has a preferable color tone and a high density magenta color recording when recorded on plain paper. It is known that the above dyes have an anilino group substituted with a sulfonic acid group and an amino group as a substituent of the triazine ring, and the dyes having higher anilino groups in plain paper are known. It is known to have water fastness (see Patent Document 2).
[0004]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 8-73791 [Patent Document 2]
JP-A-11-279469
[Problems to be solved by the invention]
However, it has been found that the dyes described in the above-mentioned documents are still insufficient in light resistance and ozone resistance, and the appearance of a dye having a better performance balance is desired.
[0006]
[Means for Solving the Problems]
The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, among the above-mentioned dyes, a recording solution containing a dye which is a sulfonic acid group and an arylamino group having a specific substituent as a substituent of a triazine ring. Has been found to provide a recorded matter having excellent light fastness and ozone fastness, and the present invention has been achieved. That is, the gist of the present invention is to provide a recording liquid comprising an aqueous medium and at least one dye selected from monoazo dyes represented by the following general formula (1) in the form of a free acid; It exists in the monoazo dye for recording liquid shown in 1).
[0007]
Embedded image

[0008]
(Wherein, R ₁ , R ₂ and R ₃ each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a COOH group, a substituted or unsubstituted alkyl group having 1 to 9 carbon atoms, Substituted or unsubstituted alkoxy group, substituted or unsubstituted carbamoyl group, substituted or unsubstituted sulfamoyl group, substituted or unsubstituted amino group, substituted or unsubstituted alkylsulfonyl group having 1 to 9 carbon atoms, A substituted or unsubstituted arylsulfonyl group having 6 to 15 carbon atoms, a sulfonic acid ester group or a carboxylic acid ester group,
m represents a number of 0, 1 or 2;
R ₄ represents a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 9 carbon atoms,
R ₅ is a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 18 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted A click group or a substituted or unsubstituted heterocyclic group,
Z is the following general formula (2)
[0009]
Embedded image

[0010]
(Wherein, R ₆ , R ₇ and R ₈ are each independently a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a COOH group, a substituted or unsubstituted alkyl group having 1 to 9 carbon atoms, 1 to 9 represents a substituted or unsubstituted alkoxy group, a substituted or unsubstituted carbamoyl group, a substituted or unsubstituted sulfamoyl group, a substituted amino group, a sulfonic acid ester group or a carboxylic acid ester group, and n represents 1 or 2. Here, when n is 1, the sulfonic acid group is located at the para position.) Or the following general formula (3)
[0011]
Embedded image

[0012]
(Wherein, R ₉ , R ₁₀ and R ₁₁ each independently represent a hydrogen atom, a hydroxyl group, a nitro group, a COOH group or a substituted or unsubstituted amino group, and p represents an integer of 2 or 3. )). )
Hereinafter, the present invention will be described in detail.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
The dye used in the present invention has a free acid form represented by the general formula (1).
In the above general formula (1), R ₁ , R ₂ and R ₃ each independently represent a hydrogen atom; a halogen atom such as a fluorine atom, a chlorine atom and a bromine atom; a hydroxyl group; a nitro group; a COOH group; Substituted or unsubstituted alkoxy group having 1 to 9 carbon atoms; substituted or unsubstituted carbamoyl group; substituted or unsubstituted sulfamoyl group; substituted or unsubstituted amino group; A substituted or unsubstituted alkylsulfonyl group having 1 to 9 carbon atoms; a substituted or unsubstituted arylsulfonyl group having 6 to 15 carbon atoms; a sulfonic acid ester group or a carboxylic acid ester group.
[0014]
Here, the substituted or unsubstituted alkyl group having 1 to 9 carbon atoms includes a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a trifluoromethyl group, a dimethylaminomethyl group and the like. And an alkyl group which may be substituted with a substituent selected from the group consisting of an atom and an amino group. Among them, preferred are those having 1 to 4 carbon atoms, and particularly preferred are haloalkyl groups having 1 to 4 carbon atoms. And particularly preferably a trifluoromethyl group.
[0015]
Examples of the substituted or unsubstituted alkoxy group having 1 to 9 carbon atoms include an methoxy group, an ethoxy group, an isopropoxy group, an n-butoxy group, an alkoxy group which may be substituted with a hydroxyl group such as a hydroxyethoxy group, Among them, those having 1 to 4 carbon atoms are preferred, more preferred are unsubstituted alkoxy groups having 1 to 4 carbon atoms, and particularly preferred are methoxy groups.
[0016]
Examples of the substituted or unsubstituted carbamoyl group include a carbamoyl group which may be substituted with a substituent selected from the group consisting of an alkyl group and an aryl group such as a carbamoyl group, an N, N-dimethylcarbamoyl group and a phenylcarbamoyl group. And preferably a carbamoyl group.
Examples of the substituted or unsubstituted sulfamoyl group include a sulfamoyl group, an N-methylsulfamoyl group, an N-ethylsulfamoyl group, an N-ethyl-N-phenylsulfamoyl group, and an N, N-dimethylsulfamoyl group. And a sulfamoyl group which may be substituted with a substituent selected from the group consisting of an alkyl group and an aryl group such as p-carboxyphenylsulfamoyl group, and among them, a sulfamoyl group is preferable.
[0017]
Examples of the substituted or unsubstituted amino group include an alkyl group such as an N-methylamino group, an N, N-dimethylamino group, an N, N-diethylamino group, a phenylamino group, a carbamoylamino group and an acetylamino group, an aryl group, Examples include an amino group which may be substituted with a substituent selected from the group consisting of a carbamoyl group and an acyl group, of which an acylamino group is preferred, and an acetylamino group is particularly preferred.
[0018]
The substituted or unsubstituted alkylsulfonyl group having 1 to 9 carbon atoms may be substituted with a substituent selected from the group consisting of a hydroxyl group such as a methylsulfonyl group, a hydroxyethylsulfonyl group and a benzylsulfonyl group and an aryl group. Examples thereof include an alkylsulfonyl group having 1 to 9 carbon atoms, preferably an alkylsulfonyl group having 1 to 4 carbon atoms, more preferably an unsubstituted alkylsulfonyl group having 1 to 4 carbon atoms, and particularly preferably methylsulfonyl. Group.
[0019]
Examples of the substituted or unsubstituted arylsulfonyl group having 6 to 15 carbon atoms include an arylsulfonyl group which may be substituted with an alkyl group such as a phenylsulfonyl group and a tolylsulfonyl group. Examples of the sulfonic acid ester group include an alkoxysulfonyl group such as a methoxysulfonyl group and an ethoxysulfonyl group and an aryloxysulfonyl group such as a phenoxysulfonyl group. Of these, an alkoxysulfonyl group having 1 to 6 carbon atoms, preferably a benzyloxy group It is a sulfonyl group or a phenylsulfonyl group, more preferably an alkoxysulfonyl group having 1 to 4 carbon atoms.
[0020]
Examples of the carboxylate group include an alkoxycarbonyl group such as a methoxycarbonyl group and an ethoxycarbonyl group and an aryloxycarbonyl group such as a phenoxycarbonyl group. Of these, an alkoxycarbonyl group having 1 to 6 carbon atoms and a benzyloxycarbonyl group are preferred. Or a phenoxycarbonyl group, more preferably an alkoxycarbonyl group having 1 to 4 carbon atoms, and particularly preferably a methoxycarbonyl group.
[0021]
Of these, a hydrogen atom, a halogen atom, a COOH group, a trifluoromethyl group, a substituted or unsubstituted carbamoyl group, a substituted or unsubstituted sulfamoyl group, a sulfonic acid alkyl ester group having 1 to 4 carbon atoms, or a carboxylic acid Is an alkyl ester group having 1 to 4 carbon atoms.
Further, as a preferable combination of the substituents of R _{1 to} R ₃ , at least one of them is a hydrogen atom, and at least one of R _{1 to} R ₃ is a COOH group, a trifluoromethyl group, a substituted or substituted group. An unsubstituted carbamoyl group, a substituted or unsubstituted sulfamoyl group, a substituent selected from the group consisting of a sulfonic acid alkyl ester group having 1 to 4 carbon atoms and a carboxylic acid having 1 to 4 carbon atoms, It is preferable that the substitution position is ortho to the azo group, and it is particularly preferable that two of R _{1 to} R ₃ are a combination of a halogen atom and a COOH group.
[0022]
m is an integer of 0 to 2, and preferably 0 or 1.
R ₄ is a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 9 carbon atoms. Examples of the substituted or unsubstituted alkyl group having 1 to 9 carbon atoms include R _{1 to} R _{3 in} the description of R _{1 to} R _3. The same groups as exemplified can be mentioned.
Among them, R ₄ is preferably a hydrogen atom.
[0023]
R ₅ is a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 18 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted It is a click group or a substituted or unsubstituted heterocyclic group.
Examples of the substituted or unsubstituted alkyl group having 1 to 18 carbon atoms include a methyl group, an ethyl group, an n-butyl group, an n-octyl group, an ethylhexyl group, a hydroxyethyl group, a carboxypropyl group, a carboxycyclohexylmethyl group, -Carboxy-2-mercaptoethyl group, 1-carboxy-2-carbamoyl-ethyl group, 1-isopropyl-1-carboxymethyl group, 1,2-dicarboxypropyl group, benzyl group, 1-carboxy-2-phenyl- Substituted with a substituent selected from the group consisting of a hydroxyl group such as an ethyl group, a 1-carboxy-2-hydroxyphenylethyl group and a 4-carboxybenzyl group, a carboxyl group, a mercapto group, a carbamoyl group, an alicyclic group and an aryl group. Alkyl group which may be And the aryl group may be further substituted with a hydroxyl group, a carboxyl group or an alkyl group.), Of which an unsubstituted alkyl group having 1 to 4 carbon atoms is preferable, and a methyl group is particularly preferable. .
[0024]
Examples of the substituted or unsubstituted alkenyl group having 2 to 18 carbon atoms include an alkenyl group which may be substituted with an alkyl group such as a 2-methyl-1-propenyl group, a vinyl group, and an allyl group. Has 4 or less carbon atoms, and is particularly preferably a vinyl group.
The aryl group is substituted with a substituent selected from the group consisting of a hydroxyl group such as a phenyl group, a 3,4-dicarboxyphenyl group, a 4-butylphenyl group and a 4-carboxyphenyl group, an alkyl group and a carboxyl group. And a phenyl group or a naphthyl group, which is preferably a phenyl group or a naphthyl group which may be substituted with a substituent selected from the group consisting of an alkyl group and a carboxyl group, and particularly preferably a phenyl group.
[0025]
Examples of the alicyclic group include those having 6 to 10 carbon atoms which may be substituted with a carboxyl group such as a cyclohexyl group and a 4-carboxycyclohexyl group. Of these, a cyclohexyl group is preferable.
Examples of the heterocyclic group include those having 10 or less carbon atoms, such as a pyridyl group, a thiadiazolyl group, a benzothiazolyl group, and a 2,2,6,6-tetramethylpiperidinyl group. Examples include a nitrogen-containing heterocyclic ring having one or two nitrogen atoms, particularly a 5- to 6-membered nitrogen-containing heterocyclic ring, and among them, a pyridyl group is preferable.
[0026]
Among them, R ₅ is preferably a hydrogen atom, an alkyl group or an aryl group, and particularly preferably a hydrogen atom.
Z is a group represented by the general formula (2) or (3).
In the group represented by the general formula (2), R ₆ , R ₇ and R ₈ are each independently a hydrogen atom; a halogen atom such as a fluorine atom, a chlorine atom and a bromine atom; a hydroxyl group; a nitro group; A substituted or unsubstituted alkoxy group having 1 to 9 carbon atoms; a substituted or unsubstituted carbamoyl group; a substituted or unsubstituted sulfamoyl group; a substituted amino group; A sulfonic acid ester group or a carboxylic acid ester group, of which a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a COOH group, a substituted or unsubstituted alkyl group having 1 to 9 carbon atoms, and a substitution having 1 to 9 carbon atoms Or an unsubstituted alkoxy group, a substituted or unsubstituted carbamoyl group, a substituted or unsubstituted sulfamoyl group, a sulfonic ester group or Rubonate groups are preferred.
[0027]
A substituted or unsubstituted alkyl group having 1 to 9 carbon atoms; a substituted or unsubstituted alkoxy group having 1 to 9 carbon atoms; a substituted or unsubstituted carbamoyl group; a substituted or unsubstituted sulfamoyl group; Examples of the group and the carboxylate group include the same groups as those described in the description of R _{1 to} R ₃ , and the substituted amino group includes an N-methylamino group and an N, N- Selected from the group consisting of alkyl groups such as dimethylamino group, N, N-diethylamino group, phenylamino group, carbamoylamino group, acetylamino group and triazinylamino group, aryl group, carbamoyl group, acyl group and heterocyclic group. Examples include an amino group which may be substituted with a substituent.
[0028]
n is 1 or 2, wherein when n is 1, the sulfonic acid group is located at the para position.
In the general formula (3), R ₉ , R _10, and R ₁₁ are each independently a hydrogen atom, a hydroxyl group, a nitro group, a COOH group, or a substituted or unsubstituted amino group. Examples of the unsubstituted amino group include the same groups as those described in the description of R _{1 to} R ₃ .
[0029]
p represents an integer of 2 or 3, and is preferably 2.
Further, the dye represented by the above general formula (1) used in the present invention has at least three or more SO ₃ H groups and COOH groups, and at least three salt groups of these acids in the structure. Are preferred, and those having 8 or less, preferably 5 or less are preferred.
[0030]
In particular, those having 3 or 4 sulfonic acid groups and / or salts thereof and 1 or 2 carboxyl groups and / or salts thereof are preferable.
The dye used in the present invention may be used as it is in a free acid form represented by the general formula (1), or may be used as it is when obtained in a salt form at the time of production. May be converted to a salt form. As the salt type exchange method, any known method can be used, and examples thereof include the following methods.
1) A strong acid such as hydrochloric acid is added to an aqueous solution of a dye obtained in a salt form, and the dye is acid-precipitated in the form of a free acid. Then, the dye is treated with an alkaline solution having a desired counter ion (for example, an aqueous solution of lithium hydroxide). A method of neutralizing acidic groups and performing salt exchange.
2) A method in which a large excess of a neutral salt (for example, lithium chloride) having a desired counter ion is added to an aqueous solution of the dye obtained in a salt form, and salt exchange is performed in the form of a salting-out cake.
3) An aqueous solution of the dye obtained in the salt form is treated with a strongly acidic ion exchange resin, and the dye is acid-precipitated in the form of a free acid, and then an alkaline solution having a desired counter ion (for example, an aqueous solution of lithium hydroxide). And neutralize the acidic group of the dye with a salt.
4) A method in which an aqueous solution of a dye obtained in the form of a salt is allowed to act on a strongly acidic ion exchange resin previously treated with an alkali solution having a desired counter ion (for example, an aqueous solution of lithium hydroxide) to effect salt exchange.
[0031]
Further, the dye used in the present invention may be one in which a part of the acid group is in a salt form, and a salt type dye and a free acid type dye may be mixed. Here, whether the acidic group takes the free acid form or the salt form depends on the pKa of the dye and the pH of the ink, but usually, the sulfonic acid group takes the salt form, and the sulfonic acid group takes a salt form more than the carboxyl group. Is preferred in terms of the difficulty of ink clogging. On the other hand, a dye having a carboxyl group in an acid form is preferably used when emphasis is placed on water resistance and bleeding resistance.
[0032]
The dye used in the present invention is used at pH 2 to 12, preferably at pH 2 to 10, more preferably at pH 3 to 9.5, and shows excellent performance even when it is used as an acidic ink.
Examples of the above salt type include salts of alkali metals such as Na, Li, and K, salts of ammonium which may be substituted with an alkyl group or a hydroxyalkyl group, and salts of organic amines. Examples of the organic amine include a lower alkylamine having 1 to 6 carbon atoms, a hydroxy-substituted lower alkylamine having 1 to 6 carbon atoms, a carboxy-substituted lower alkylamine having 1 to 6 carbon atoms and a lower alkylamine having 2 to 4 carbon atoms. Examples thereof include polyamines having 2 to 10 alkyleneimine units. In the case of these salt types, the type is not limited to one type, and a plurality of types may be mixed.
[0033]
The type of the counter ion constituting the salt form is also freely selected according to the characteristics to be emphasized in the ink. Since many intermediates and reagents used in the synthesis of dyes contain Na, many are generally obtained in the form of Na salts, but when water resistance is important, they are often converted to NH ₄ salts, When it is necessary to increase the solubility of the dye and maintain the clogging of the ink at a higher level, it may be converted into a Li salt or an alkanolamine salt represented by triethanolamine.
[0034]
Specific examples of these dyes include, for example, the following Nos. Dyes having the structure shown in 1-23 are exemplified.
[0035]
Embedded image

[0036]
Embedded image

[0037]
Embedded image

[0038]
Embedded image

[0039]
Embedded image

[0040]
The monoazo dye represented by the general formula (1) can be produced according to a method known per se. For example, no. The dye represented by (1) can be produced by the following steps (A) to (C).
(A) From 2-aminobenzoic acid (anthranilic acid) and 1-amino-8-hydroxy-3,6-naphthalenedisulfonic acid (H acid) by a conventional method [for example, Yutaka Hosoda, “Shin Dye Chemistry” (Showa 48) (Published by Gihodo Co., Ltd., December 21, 2013), p. 396, p. 409] to produce a monoazo compound through a diazotization and coupling step.
(B) The obtained monoazo compound is added to the cyanuric chloride suspension while maintaining the pH at 4 to 6 and the temperature at 0 to 5 ° C, and the reaction is carried out for several hours. Next, an aqueous solution of 4-aminobenzenesulfonic acid (sulfanilic acid) is added so as not to become alkaline at room temperature, and a condensation reaction is performed for several hours. Next, a 25% aqueous sodium hydroxide solution is added at 50 to 60 ° C. to make the mixture alkaline, and a hydrolysis reaction is performed to complete the reaction.
(C) After cooling, the desired dye No. (1) is obtained.
[0041]
The content of the dye of the general formula (1) in the recording liquid is preferably 0.5 to 5% by weight, particularly preferably about 2 to 4% by weight, based on the total amount of the recording liquid.
Examples of the solvent used in the present invention include water and water-soluble organic solvents such as ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol (# 200), polyethylene glycol (# 400), glycerin, N -Methylpyrrolidone, N-ethylpyrrolidone, 1,3-dimethylimidazolidinone, thiodiethanol, dimethylsulfoxide, ethylene glycol monoallyl ether, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, 2-pyrrolidone, sulfolane, ethyl alcohol, isopropanol, etc. Is preferable. These water-soluble organic solvents are usually used in the range of 1 to 50% by weight based on the total amount of the recording liquid. On the other hand, water is used in the range of 45 to 95% by weight based on the total amount of the recording liquid.
[0042]
0.1 to 10% by weight, preferably 0.5 to 5% by weight, of a compound selected from urea, thiourea, biuret and semicarbazide is added to the recording liquid of the present invention. By adding 001 to 5.0% by weight of a surfactant, quick drying after printing and print quality can be further improved.
[0043]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples unless it exceeds the gist.
[Example 1]
10 parts by weight of diethylene glycol, 3 parts by weight of diethylene glycol monobutyl ether, Water was added to 3 parts by weight of the first dye, and the pH was adjusted to 9 with a 10% aqueous sodium hydroxide solution to make the total amount 100 parts by weight. This composition was sufficiently mixed and dissolved, filtered under pressure through a polytetrafluoroethylene filter having a pore size of 1 μm, and then deaerated by a vacuum pump and an ultrasonic cleaner to prepare a recording liquid.
[0044]
Using the obtained recording liquid, an electrophotographic paper (trade name "4024 paper" manufactured by Xerox Co., Ltd.) and a paper dedicated to Super Fine (trade name "PM-750C, manufactured by Seiko Epson Co., Ltd.") MJA4SP1 (manufactured by Seiko Epson Corporation), PM matte paper (trade name "KA450PM" manufactured by Seiko Epson Corporation) and PM photo paper (glossy) (trade name "KA420PSK" manufactured by Seiko Epson Corporation) are each inkjet-printed, and vivid magenta A color print was obtained.
The following various tests were performed on the obtained printed matter and recording liquid. Table 1 shows the results.
[0045]
[Light fastness test]
Using a xenon fade meter (manufactured by Atlas), the printed matter was observed for discoloration after light irradiation for 80 hours. The color tone before and after the test was measured using a Gretag Macbeth SPM50 (manufactured by Gretag Macbeth), and after obtaining L ^* a ^* b ^* values, the following formulas (where L ^* ₁ , a ^* _1, and b ^* _{1 are used)} Is the value obtained from the color tone measurement before the light fastness test, and L ^* ₂ , a ^* ₂ and b ^* ₂ are the values obtained from the color tone measurement after the light fastness test.). The smaller the ΔE value, the lower the degree of discoloration.
[0046]
(Equation 1)

[0047]
[Room discoloration resistance test]
The printed matter was allowed to stand for 4 hours in a light-shielded ozone concentration of 10 ppm tank, and the discoloration was observed, and the ΔE value was determined in the same manner as described above.
[Print quality test]
The chroma of the printed matter was measured using a Gretag Macbeth SPM50 (manufactured by Gretag Macbeth), and it was confirmed that all of the prints had high chroma.
[0048]
[Storage stability test of recording solution]
The recording liquid was sealed in a polytetrafluoroethylene container, and the change after storage at 5 ° C. and 60 ° C. for one month each was examined.
Examples 2 to 6
In Example 1, the above No. A recording liquid was prepared and printed in the same manner except that the dyes shown in Table 1 were used in place of the dye No. 1, and a magenta color print having a clear color tone was obtained in each case.
[0049]
Various tests were performed on the obtained printed matter and recording liquid in the same manner as in Example 1. Table 1 shows the results.
Comparative Example 1
In Example 1, the above No. In place of the dye No. 1, No. 1 described in JP-A-8-73791. The recording liquid was prepared in the same manner except that the dye No. 1 was used, and printing was performed. As a result, a magenta printed matter having a clear color tone was obtained.
[0050]
Various tests were performed on the obtained printed matter and recording liquid in the same manner as in Example 1. Table 1 shows the results.
Comparative Example 2
In Example 1, the above No. No. 1 described in JP-A-11-279469. The recording liquid was prepared in the same manner except that the dye No. 2 was used, and printing was performed. As a result, a magenta printed matter having a clear color tone was obtained.
[0051]
Various tests were performed on the obtained printed matter and recording liquid in the same manner as in Example 1. Table 1 shows the results.
[0052]
[Table 1]

[0053]
【The invention's effect】
The dye for inkjet recording of the present invention is excellent in water solubility, and the recording liquid of the present invention using this dye can obtain clear printed matter even when recorded on plain paper and special paper for aqueous inkjet recording. In addition, the density of the recorded image is high, the light resistance and the indoor discoloration resistance are excellent, and the stability when stored for a long period of time is good.

Claims (3)

A recording liquid comprising an aqueous medium and at least one dye selected from monoazo dyes represented by the following general formula (1) in the form of a free acid.

(Wherein, R ₁ , R ₂ and R ₃ each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a COOH group, a substituted or unsubstituted alkyl group having 1 to 9 carbon atoms, Substituted or unsubstituted alkoxy group, substituted or unsubstituted carbamoyl group, substituted or unsubstituted sulfamoyl group, substituted or unsubstituted amino group, substituted or unsubstituted alkylsulfonyl group having 1 to 9 carbon atoms, A substituted or unsubstituted arylsulfonyl group having 6 to 15 carbon atoms, a sulfonic acid ester group or a carboxylic acid ester group,
m represents a number of 0, 1 or 2;
R ₄ represents a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 9 carbon atoms,
R ₅ is a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 18 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted A click group or a substituted or unsubstituted heterocyclic group,
Z is the following general formula (2)

(Wherein, R ₆ , R ₇ and R ₈ are each independently a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a COOH group, a substituted or unsubstituted alkyl group having 1 to 9 carbon atoms, 1 to 9 represents a substituted or unsubstituted alkoxy group, a substituted or unsubstituted carbamoyl group, a substituted or unsubstituted sulfamoyl group, a substituted amino group, a sulfonic acid ester group or a carboxylic acid ester group, and n represents 1 or 2. Here, when n is 1, the sulfonic acid group is located at the para position.) Or the following general formula (3)

(Wherein, R ₉ , R ₁₀ and R ₁₁ each independently represent a hydrogen atom, a hydroxyl group, a nitro group, a COOH group or a substituted or unsubstituted amino group, and p represents an integer of 2 or 3. )). ) m is 0, and at least one of R _{1 to} R ₃ is a trifluoromethyl group, a COOH group, a substituted or unsubstituted carbamoyl group, a substituted or unsubstituted sulfamoyl group, or a sulfonic acid having 1 to 4 carbon atoms. A substituent selected from the group consisting of an alkyl ester group and an alkyl ester group having 1 to 4 carbon atoms of a carboxylic acid, wherein the substitution position is ortho to the azo group, and at least one of the remaining is a hydrogen atom The recording liquid according to claim 1, wherein: A monoazo dye for a recording liquid having a free acid form represented by the following general formula (1).

(Wherein, R ₁ , R ₂ and R ₃ each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a COOH group, a substituted or unsubstituted alkyl group having 1 to 9 carbon atoms, Substituted or unsubstituted alkoxy group, substituted or unsubstituted carbamoyl group, substituted or unsubstituted sulfamoyl group, substituted or unsubstituted amino group, substituted or unsubstituted alkylsulfonyl group having 1 to 9 carbon atoms, A substituted or unsubstituted arylsulfonyl group having 6 to 15 carbon atoms, a sulfonic acid ester group or a carboxylic acid ester group,
m represents a number of 0, 1 or 2;
R ₄ represents a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 9 carbon atoms,
R ₅ is a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 18 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted A click group or a substituted or unsubstituted heterocyclic group,
Z is the following general formula (2)

(Wherein, R ₆ , R ₇ and R ₈ are each independently a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a COOH group, a substituted or unsubstituted alkyl group having 1 to 9 carbon atoms, 1 to 9 represents a substituted or unsubstituted alkoxy group, a substituted or unsubstituted carbamoyl group, a substituted or unsubstituted sulfamoyl group, a substituted amino group, a sulfonic acid ester group or a carboxylic acid ester group, and n represents 1 or 2. Here, when n is 1, the sulfonic acid group is located at the para position.) Or the following general formula (3)

(Wherein, R ₉ , R ₁₀ and R ₁₁ each independently represent a hydrogen atom, a hydroxyl group, a nitro group, a COOH group or a substituted or unsubstituted amino group, and p represents an integer of 2 or 3. )). )