JP2004269596A - Recording liquid, method for ink-jet recording and equipment for recording using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for ink-jet recording with which high-grade image quality comparable to that of a laser printer can be obtained on plain paper by one-pass printing in spite of a permeation ink and to provide a recording ink. <P>SOLUTION: A recording liquid has 2-37 pl Mj (volume of one ink drop), 6-20 m/s Vj (speed of the ink drop), ≥1 KHz frequency and ≥300 dpi resolution. In the one-pass printing, the recording liquid has ≥10 wt.% of colorant concentration and ≥8 mPa s (25°C) ink viscosity and contains 2-methyl-2,4-pentanediol and 2-ethyl-1,3-hexanediol and is regulated to ≤500 ppm liberated monovalent anion concentration present in the recording liquid. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

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本発明で用いられる顔料としては、有機顔料としてアゾ系、フタロシアニン系、アントラキノン系、ジオキサジン系、インジゴ系、チオインジゴ系、ペリレン系、イソインドレノン系、アニリンブラック、アゾメチン系、ロ−ダミンＢレ−キ顔料、カ−ボンブラック等が挙げられ、無機顔料として酸化鉄、酸化チタン、炭酸カルシウム硫酸バリウム、水酸化アルミニウム、バリウムイエロ−、紺青、カドミウムレッド、クロムイエロ−、金属粉が挙げられる。
【００７０】
より具体的には、黒用顔料として、ファーネスブラック、ランプブラック、アセチレンブラック、チャンネルブラック等のカーボンブラック（Ｃ．Ｉ．ピグメントブラック７）類、又は銅酸化物、鉄酸化物（Ｃ．Ｉ．ピグメントブラック１１）、若しくは酸化チタン等の金属類、アニリンブラック（Ｃ．Ｉ．ピグメントブラック１）等の有機顔料を挙げることができる。
【００７１】
カラーインク用顔料としては黄色インク用でＣ．Ｉ．ピグメントイエロー１（ファストイエローＧ）、３、１２（ジスアゾイエローＡＡＡ）、１３、１４、１７、２３、２４、３４、３５、３７、４２（黄色酸化鉄）、５３、５５、７４、８１、８３（ジスアゾイエローＨＲ）、９５、９７、９８、１００、１０１、１０４、１０８、１０９、１１０、１１７、１２０、１２８、１３８、１５０、１５３
【００７２】
マゼンタ用でＣ．Ｉ．ピグメントレッド１、２、３、５、１７、２２（ブリリアントファーストスカーレット）、２３、３１、３８、４８：２（パーマネントレッド２Ｂ（Ｂａ））、４８：２（パーマネントレッド２Ｂ （Ｃａ））、４８：３（パーマネントレッド２Ｂ（Ｓｒ））、４８：４（パーマネントレッド２Ｂ（Ｍｎ））、４９：１、５２：２、５３：１、５７：１（ブリリアントカーミン６Ｂ）、６０：１、６３：１、６３：２、６４：１、８１（ローダミン６Ｇレーキ）、８３、８８、９２、１０１（べんがら）、１０４、１０５、１０６、１０８（カドミウムレッド）、１１２、１１４、１２２（ジメチルキナクリドン）、１２３、１４６、１４９、１６６、１６８、１７０、１７２、１７７、１７８、１７９、１８５、１９０、１９３、２０９、２１９
【００７３】
シアン用でＣ．Ｉ．ピグメントブルー１、２、１５（銅フタロシアニンブルーＲ）、１５：１、１５：２、１５：３（フタロシアニンブルーＧ）、１５：４、１５：６（フタロシアニンブルーＥ）、１６、１７：１、５６、６０、６３；等を使用することができる。
【００７４】
また中間色としてはレッド、グリーン、ブルー用として下記顔料を単独もしくは混合して用いることができる。
Ｃ．Ｉ．ピグメントレッド１７７、１９４、２２４、Ｃ．Ｉ．ピグメントオレンジ４３、Ｃ．Ｉ．ピグメントバイオレット３，１９，２３，３７、Ｃ．Ｉ．ピグメントグリーン７，３６
【００７５】
黒としてはカーボンブラックとしては、ファーネス法、チャネル法で製造されたカーボンブラックで、１次粒子が１５ｎｍから４０ｎｍ、ＢＥＴ吸着法による比表面積が５０〜３００ｍ^２／ｇ、ＤＢＰ吸油量が４０〜１５０ｍｌ／１００ｇ、揮発分が０．５〜１０％、ｐＨ２〜９を有するものが使用され、特にｐＨ６以下の酸性カーボンブラックが高濃度で好ましい。また次亜塩素酸化処理したカーボンブラックやスルホン化剤処理したカーボンブラック、ジアゾニュウム化合物にて処理してスルホン酸、カルボン酸等のアニオン性解離基を導入したカーボンブラックがさらに好ましい。
【００７６】
イエロー顔料としてはベンチジン骨格を含まないＣ．Ｉピグメントイエロー７４、１２８、１３８が好ましい。
マゼンタ顔料としてはキナクリドン系のＣ．Ｉ．ピグメントレッド１２２、２０９が好ましい。シアンはフタロシアニン化合物であるＣ．Ｉ．ピグメントブルー１５：３やアルミ配位フタロシアニン、無金属フタロシアニンが好ましい。これらカラー有機顔料も表面処理によりスルホン酸基、カルボン酸基が導入された顔料はさらに分散安定性が優れ、分散剤なしに分散安定性が得られるものは自己分散顔料として好適に用いることができる。また表面をカプセル化した顔料やポリマーをグラフトした顔料等も分散安定性に優れ信頼性の高いインクとすることができる。
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次に、表面処理を施した顔料分散液の調製方法を参考例１〜５として示す。
＜製造例１＞ 次亜塩素酸処理したカーボンブラック分散液１
市販のｐＨ２．５の酸性カーボンブラック（キャボット社製 商品名モナーク１３００）３００ｇを水１０００ミリリットルに良く混合した後に次亜塩素酸ソーダ（有効塩素濃度１２％）４５０ｇを滴下して、１００〜１０５℃で８時間撹拌した。この液に更に次亜塩素酸ソーダ（有効塩素濃度１２％）１００ｇを加え、横型分散機で３時間分散した。得られたスラリーを水で１０倍に希釈し、水酸化リチウムにてｐＨを調整し、電導度０．２ｍＳ／ｃｍまで限外濾過膜にて脱塩濃縮し顔料濃度２０％のカーボンブラック分散液とした。遠心処理により粗大粒子を除き、さらに１ミクロンのナイロンフィルターで濾過しカーボンブラック分散液１とした。Ｆｅ，Ｃａ，Ｓｉの含有量の総計がＩＣＰの測定により１００ｐｐｍ以下であった。また塩素イオン濃度も１０ｐｐｍ以下とした。マイクロトラックＵＰＡで測定した平均粒子径（Ｄ５０％）は９５ｎｍであった。
【００７８】
＜製造例２＞ スルホン化剤処理したカーボンブラック分散液２
市販のカーボンブラック顔料（デグサ社製「プリンテックス＃８５」）１５０ｇをスルホラン４００ｍｌ中に良く混合し、ビーズミルで微分散後、アミド硫酸１５ｇを添加して１４０〜１５０℃で１０時間攪拌した。得られたスラリーをイオン交換水１０００ｍｌ中に投入し、１２０００ｒｐｍで遠心分離機により表面処理カーボンブラックウエットケーキを得る。このカーボンブラックウエットケーキを２０００ｍｌのイオン交換水中に再分散し、水酸化リチウムにてｐＨを調整し、限外濾過膜により脱塩濃縮し顔料濃度２０重量％のカーボンブラック分散液とした。このものを１ミクロンのナイロンフィルターで濾過しカーボンブラック分散液２とした。Ｆｅ，Ｃａ，Ｓｉの含有量の総計はＩＣＰの測定により１００ｐｐｍ以下であった。また硫酸イオン濃度も１００ｐｐｍ以下であった。平均粒子径は８０ｎｍであった。
【００７９】
＜製造例３＞ ジアゾ化合物処理したカーボンブラック分散液３
表面積が２３０ｍ^２／ｇでＤＢＰ吸油量が７０ｍｌ／１００ｇのカーボンブラック１００ｇと、ｐ−アミノ−Ｎ−安息香酸３４ｇとを水７５０ｇに混合分散し、これに硝酸１６ｇを滴下して７０℃で撹拌した。５分後、５０ｇの水に１１ｇの亜硝酸ナトリウムを溶かした溶液を加え、更に１時間撹拌した。得られたスラリーを１０倍に希釈し遠心処理し粗大粒子を除き、ｐＨをジエタノールアミンにて調整しｐＨ８−９とし、限外濾過膜にて脱塩濃縮し顔料濃度２０重量％のカーボンブラック分散液とした。このものをポリプロピレンの０．５μｍフィルターにてカーボンブラック分散液３とした。Ｆｅ，Ｃａ，Ｓｉの含有量の総計はＩＣＰの測定により１００ｐｐｍ以下であった。また硝酸イオン濃度は１０ｐｐｍ以下であった。平均粒子径は９９ｎｍであった。
【００８０】
＜製造例４＞ ジアゾ化合物処理したカーボンブラック分散液４
２リットルの水と４３ｇのスルファニル酸を含む約７５℃の溶液を、撹拌しながら、２３０ｍ^２／ｇの表面積と７０ｍｌ／１００ｇのＤＢＰＡを有する ２０２ｇのカーボンブラックに添加した。この混合物を撹拌しながら室温まで冷やし、２６．２ｇの濃硝酸を添加した。水中の亜硝酸ナトリウムの２０．５ｇの溶液を添加した。４−スルホベンゼンジアゾニウム水酸化物内部塩を作製し、これをカーボンブラックと反応させた。発生した泡立ちが停止するまで分散系を撹拌した。得られたスラリーを希釈し、水酸化リチウムにてｐＨを調整しｐＨ８−９として粗大粒子を遠心処理にて除き、引き続いて限外濾過膜にて脱塩濃縮し顔料濃度２０％のカーボンブラック分散液とした。このものをポリプロピレンの１μｍフィルターにて濾過しカーボンブラック分散液４とした。Ｆｅ，Ｃａ，Ｓｉの含有量の総計はＩＣＰの測定により１００ｐｐｍ以下であった。また硝酸イオン濃度は５０ｐｐｍ以下であった。平均粒子径は９５ｎｍであった。
【００８１】
＜製造例５＞ 表面化学処理したカラー顔料分散液（イエロー分散液１、マゼンタ分散液１、シアン分散液１）
イエロー顔料としてＣ．Ｉ．ピグメントイエロー１２８を低温プラズマ処理しカルボン酸基を導入した顔料を作製した。これをイオン交換水に分散したものを、限外濾過膜にて脱塩濃縮し顔料濃度２０％のイエロー顔料分散液１とした。平均粒子径７０ｎｍ、Ｆｅ，Ｃａ，Ｓｉの含有量の総計は１００ｐｐｍ以下であった。
【００８２】
同様にマゼンタ顔料としてＣ．Ｉ．ピグメントマゼンタ１２２を用いて顔料濃度２０％のマゼンタ顔料分散液１を作製した。平均粒子６０ｎｍ、Ｆｅ，Ｃａ，Ｓｉの含有量の総計は１００ｐｐｍ以下であった。
【００８３】
同様にシアン顔料としてＣ．Ｉ．ピグメントシアン１５：３を用いて顔料濃度２０％のシアン顔料分散液１を作製した。平均粒子径８０ｎｍ、Ｆｅ，Ｃａ，Ｓｉの含有量の総計は１００ｐｐｍ以下であった。
【００８４】
また、本発明においては、顔料分散剤を用いた顔料分散液を用いることもできる。顔料分散剤としては親水性高分子として，天然系では、アラビアガム、トラガンガム、グ−アガム、カラヤガム、ロ−カストビ−ンガム、アラビノガラクトン、ペクチン、クインスシ−ドデンプン等の植物性高分子、アルギン酸、カラギ−ナン、寒天等の海藻系高分子、ゼラチン、カゼイン、アルブミン、コラ−ゲン等の動物系高分子、キサンテンガム、デキストラン等の微生物系高分子、半合成系では、メチルセルロ−ス、エチルセルロ−ス、ヒドロキシエチルセルロ−ス、ヒドロキシプロピルセルロ−ス、カルボキシメチルセルロ−ス等の繊維素系高分子、デンプングリコ−ル酸ナトリウム、デンプンリン酸エステルナトリウム等のデンプン系高分子、アルギン酸ナトリウム、アルギン酸プロピレングリコ−ルエステル等の海藻系高分子、純合成系では、ポリビニルアルコ−ル、ポリビニルピロリドン、ポリビニルメチルエ−テル等のビニル系高分子、非架橋ポリアクリルアミド、ポリアクリル酸及びそのアルカリ金属塩、水溶性スチレンアクリル樹脂等のアクリル系樹脂、水溶性スチレンマレイン酸樹脂、水溶性ビニルナフタレンアクリル樹脂、水溶性ビニルナフタレンマレイン酸樹脂、ポリビニルピロリドン、ポリビニルアルコ−ル、β−ナフタレンスルホン酸ホルマリン縮合物のアルカリ金属塩、四級アンモニウムやアミノ基等のカチオン性官能基の塩を側鎖に有する高分子化合物、セラック等の天然高分子化合物等が挙げられる。
特にアクリル酸、メタクリル酸、スチレンアクリル酸のホモポリマーや他の親水基を有するモノマーの共重合体からなるようなカルボン酸基を導入したものが高分子分散剤として好ましい。
【００８５】
また界面活性剤を用いる場合はポリオキシエチレンアルキルエーテル燐酸塩、ポリオキシエチレンアルキルエーテル酢酸塩等のアニオン界面活性剤、ノニルフェニルエーテル等ノニオン系界面活性剤を用いることもできる。
【００８６】
次に、顔料分散剤を用いた顔料分散液の製造例を製造例６として示す。
＜製造例６＞ 分散剤顔料分散液（界面活性剤分散によるイエロー分散液２、マゼンタ分散液２、シアン分散液２、高分子分散によるイエロー分散液３、マゼンタ分散液３、シアン分散液３）
顔料及び分散剤としては次のものを用いた。
イエロー顔料：Ｃ．Ｉ．ピグメントイエロー１２８、マゼンタ顔料：Ｃ．Ｉ．ピグメントレッド１２２、シアン顔料：Ｃ．Ｉ．ピグメントブルー１５：３
分散剤Ａ：花王社製ノニオン性界面活性剤「エマルゲン ９１３」）、ＨＬＢ１５．５
分散剤Ｂ：ジョンソンポリマー社製アクリル系樹脂水溶液「ジョンクリル ６１１」（アンモニア中和、固形分２０％）、酸価 ５７
【００８７】
上記の顔料及び分散材を用いて次の工程により顔料分散液を製造した。
▲１▼ ソルトミリング微細化工程
ステンレス製１ガロンニーダー（井上製作所社製）に上記の顔料２５０部、塩化ナトリウム２５００部およびジエチレングリコール２００部を仕込み，３時間混練した。つぎに，この混合物を２．５リットルの温水に投入し，約８０℃に加熱しながらハイスピードミキサーで約１時間撹拌してスラリー状とした後，濾過，水洗を５回くりかえして塩化ナトリウムおよび溶剤を除き、顔料の乾燥品を得た。
【００８８】
▲２▼表面処理工程
ペイントコンディショナーに、顔料２０部と上記Ａ，Ｂの分散剤と水を加え全量で１００部として３時間分散した。得られた水性顔料分散体に１５０００ｒｐｍで６時間の遠心分離を施した。
表面処理顔料２０部に３０％アンモニア水０．１部、精製水７９．９部を加え、ペイントコンディショナーで再分散し、顔料濃縮液を作製した。濃縮液は１μｍナイロンフィルターにて濾過，続いて０．５μｍのポリピロピレンフィルターにて濾過し使用分散液とした。
【００８９】
それぞれのＦｅ、Ｃａ，Ｓｉの含有量はいずれも１００ｐｐｍ以下であった。
この分散液の平均粒子径は次のとおりであった。
イエロー分散液２ ：９３ｎｍ、 イエロー分散液３ ：８０ｎｍ
マゼンタ分散液２ ：６０ｎｍ、 マゼンタ分散液３ ：５６ｎｍ
シアン分散液 ２ ：９０ｎｍ、 シアン分散液 ３ ：８７ｎｍ
【００９０】
本発明では色材として染料、顔料で着色された微粒子を用いることにより普通紙での定着性の改良、発色性の改良を行い、一価アニオン濃度を調整することで凝集等が起こりにくい着色微粒子記録液を得ることができる。着色微粒子としては微粒子が高分子からなるもの、シリカ、アルミナ等の無機微粒子からなるもののいずれも用いることができる。光沢性を付与する目的からは高分子微粒子を用いることが好ましい。
【００９１】
特にアクリル系やポリエステル系の微粒子に染顔料が含浸されたもの、即ち、表層もしくは内部、あるいは全体に染顔料が存在する着色高分子微粒子を用いることが好ましい。より具体的には特開平２０００−５３８９８号公報に開示された方法により製造された着色微粒子が挙げられる。
【００９２】
以下に、これに準じた着色微粒子の製造例を製造例７として示す。
＜製造例７＞
攪拌翼、冷却管、窒素ガス導入管を取り付けた密閉可能な反応容器に、重合溶媒としてメチルエチルケトン２０重量部、重合性不飽和モノマーとして下記の組成の初期仕込みモノマー及び重合連鎖移動剤を仕込み、窒素ガス置換を充分行った。
【００９３】
メタクリル酸メチル、モノマー １２．８重量部
メタクリル酸２−ヒドロキシエチル、モノマー １．２重量部
メタクリル酸、モノマー ２．９重量部
シリコーンマクロマー（チッソ（株）製 ＦＭ−０７１１） ２重量部
スチレンアクリルニトリルマクロマー １重量部
（東亜合成（株）製 ＡＮ−６）
メルカプトエタノール（重合連鎖移動剤） ０．３重量部
【００９４】
次いで、窒素雰囲気下、反応容器内の混合液を撹拌しながら６５℃まで昇温させた。
これとは別に、下記の滴下モノマー及び重合連鎖移動剤とメチルエチルケトン６０部と、２，２’−アゾビス（２，４−ジメチルバレロニトリル）０．２部とを混合し、充分窒素置換して得られた混合液を３時間かけて反応容器内に徐々に滴下した。
【００９５】
メタクリル酸メチル、モノマー ５１重量部
メタクリル酸２−ヒドロキシエチル、モノマー ４．２重量部
メタクリル酸、モノマー １１重量部
シリコーンマクロマー（チッソ（株）製 ＦＭ−０７１１） ８重量部
スチレンアクリルニトリルマクロマー ４重量部
（東亜合成（株）製 ＡＮ−６）
メルカプトエタノール（重合連鎖移動剤） １．２重量部
【００９６】
滴下が終了して２時間後、２，２’−アゾビス（２，４−ジメチルバレロニトリル）０．１重量部をメチルエチルケトン５重量部に溶解した溶液を加え、更に６５℃で２時間、７０℃で２時間熟成させることによりビニル系ポリマー溶液を得た。
得られたビニル系ポリマー溶液の一部を、減圧下、１０５℃で２時間乾燥させ、完全に溶媒を除去することによって単離した。重量平均分子量は約１０，０００、Ｔｇ１８０℃であった。
【００９７】
上記で得られたビニル系ポリマー溶液を減圧乾燥させて得られたビニル系ポリマー５ｇに、トルエン２５ｇおよびアントラキノン系染料
【００９８】
【化１８】

【００９９】
５ｇを加えて完全に溶解させ、水酸化ナトリウム水溶液を２ｇ加えてビニル系ポリマーの酸性基を一部中和した。次いで、イオン交換水３００ｇを加え、撹拌した後、乳化装置であるナノメーカーＴＭ（ナノマイザー社製）を用いて、３０分間乳化した。得られた乳化物を減圧下６０℃でトルエンを完全に除去し、更に一部の水を除去することにより濃縮し、限外濾過膜にてモノマー等不純物を除去し、精製された分散性染料を含浸させたビニル系ポリマー微粒子のマゼンタ分散液４（平均粒径；９８ｎｍ、固形分濃度；２０％）を得た。
【０１００】
同様にして染料をＣ．Ｉ．ディスパースイエロー１１８としてイエロー分散液４（平均粒径；９８ｎｍ、固形分濃度；２０％）、Ｃ．Ｉ．ディスパースブルー３６としてブルー分散液４（平均粒径；９８ｎｍ、固形分濃度；２０％）を得た。
【０１０１】
本発明では界面活性剤を使用することで記録紙への濡れ性を改善することができる。好ましい界面活性剤としては界面ポリオキシエチレンアルキルエーテル酢酸塩、ジアルキルスルホ琥珀酸塩、ポリオキシエチレンアルキルエーテル、ポリオキシエチレンアルキルフェニルエーテル、ポリオキシエチレンポリオキシプロピレンブロック共重合体、アセチレングリコール系界面活性剤が挙げられる。より具体的にはアニオン系界面活性剤としては、下記一般式（ＩＩ）で表されるポリオキシエチレンアルキルエーテル酢酸塩、及び／または下記一般式（ＩＩＩ）で表される炭素鎖が５〜７の分岐したアルキル鎖を有するジアルキルスルホ琥珀酸）を用いることで普通紙特性も改善されさらに着色剤の溶解・分散安定性が得られる。
【０１０２】
【化１９】

【０１０３】
【化２０】

【０１０４】
【０１０５】
好ましい非イオン系の界面活性剤としてポリオキシエチレンアルキルフェニルエーテルである一般式（ＩＶ）、アセチレングリコール系界面活性剤である一般式（Ｖ）の活性剤があげられる。これらを併用することによりさらに相乗効果として浸透性があげられ、これにより色境界にじみが低減されまた文字にじみも少ないインクが選られる。
【０１０６】
【化２１】

【０１０７】
【化２２】

【０１０８】
なお、このインクのｐＨを６以上にすることによりインクの保存安定性が得られ、また、オフィスで使用されているコピ−用紙や用箋等はｐＨが５〜６のものが多く、これらの記録紙にインクを９〜６０μｍの微細な吐出口より吐出し重量が２ｎｇ〜５０ｎｇの液滴として５〜２０ｍ／ｓで飛翔させ、単色での付着量を１．５ｇ／ｍ^２から３０ｇ／ｍ^２としてＪＩＳ Ｐ−８１２２試験法によるステキヒトサイズ度が３秒以上の所謂普通紙に記録するこにより高画質、高解像の記録画像を形成する記録方式を提供することができる。ただし、ｐＨが９以上では保存時に（ＩＩＩ）の活性剤では分解による物性変化が起こりやすいため（ＩＩＩ）を用いる場合はｐＨを６〜９とすることが好ましい。
【０１０９】
本発明に用いることができる（ＩＩ）、（ＩＩＩ）、（ＩＶ）（Ｖ）の添加量は０．０５〜１０重量％の間でプリンタ−システムにより要求されるインク特性に対し所望の浸透性をあたえることが可能である。ここで０．０５％以下ではいずれの場合も２色重ね部の境界でのにじみが発生し、１０重量％以上添加する場合は化合物自体が低温で析出しやすことがあり信頼性が悪くなる。
【０１１０】
次に本発明に用いる界面活性剤（ＩＩ）、（ＩＩＩ）を具体的に遊離酸型で示す。
【０１１１】
【化２３】

【０１１２】
【化２４】

【０１１３】
本発明のインクは水を液媒体として使用するものであるが、インクを所望の物性にするため、インクの乾燥を防止するために、また、本発明の化合物の溶解安定性を向上するため等の目的で下記の水溶性有機溶媒を使用することができる。
【０１１４】
エチレングリコ−ル、ジエチレングリコ−ル、トリエチレングリコ−ル、ポリエチレングリコ−ル、ポリプロピレングリコ−ル、１、３−プルパンジオール、１，３−ブタンジオール、１，４ブタンジオール、１，５ペンタンジオール、１、６ヘキサンジオ−ル、グリセロ−ル、１、２、６−ヘキサントリオ−ル、１、２、４−ブタントリオ−ル、１、２、３−ブタントリオ−ル、ペトリオール等の多価アルコ−ル類、エチレングリコ−ルモノエチルエ−テル、エチレングリコ−ルモノブチルエ−テル、ジエチレングリコ−ルモノメチルエ−テル、ジエチレングリコ−ルモノエチルエ−テル、ジエチレングリコ−ルモノブチルエ−テル、テトラエチレングリコ−ルモノメチルエ−テル、プロピレングリコ−ルモノエチルエ−テル等の多価アルコ−ルアルキルエ−テル類、エチレングリコ−ルモノフェニルエ−テル、エチレングリコ−ルモノベンジルエ−テル等の多価アルコ−ルアリ−ルエ−テル類；Ｎ−メチル−２−ピロリドン、Ｎ−ヒドロキシエチル−２−ピロリドン、２−ピロリドン、１，３−ジメチルイミダゾリジノン、ε−カプロラクタム等の含窒素複素環化合物；ホルムアミド、Ｎ−メチルホルムアミド、ホルムアミド、Ｎ，Ｎ−ジメチルホルムアミド等のアミド類；モノエタノ−ルアミン、ジエタノ−ルアミン、トリエタノ−ルアミン、モノエチルアミン 、ジエチルアミン、トリエチルアミン等のアミン類、ジメチルスルホキシド、スルホラン、チオジエタノ−ル等の含硫黄化合物類、プロピレンカ−ボネ−ト、炭酸エチレン、γ−ブチロラクトン等。
これらの溶媒は、水とともに単独もしくは、複数混合して用いられる。
【０１１５】
これらの中で特に好ましいものはジエチレングリコ−ル、チオジエタノ−ル、ポリエチレングリコ−ル２００〜６００、トリエチレングリコ−ル、グリセロ−ル、１，２，６−ヘキサントリオ−ル、１、２、４−ブタントリオ−ル、ペトリオール、１，３ブタンジオール、２，３ブタンジオール、１、４−ブタンジオール、１，５−ペンタンジオ−ル、Ｎ−メチル−２−ピロリドン，Ｎ−ヒドロキシエチルピロリドン、２−ピロリドン、１、３−ジメチルイミダゾリジノンであり、これらを用いることにより本化合物の高い溶解性と水分蒸発による噴射特性不良の防止に対して優れた効果が得られる。
特に本発明において着色剤の分散安定性を得るのに好ましい溶剤としてＮ−ヒドロキシエチル２ーピロリドン等のピロリドン誘導体が挙げられる。
【０１１６】
また、本発明の界面活性剤（ＩＩ）〜（Ｖ）以外で表面張力を調整する目的で添加される浸透剤としては、ジエチレングリコ−ルモノフェニルエ−テル、エチレングリコ−ルモノフェニルエ−テル、エチレングリコ−ルモノアリルエ−テル、ジエチレングリコ−ルモノフェニルエ−テル、ジエチレングリコ−ルモノブチルエ−テル、プロピレングリコ−ルモノブチルエ−テル、トリエチレングリコールモノブチルエーテル、テトラエチレングリコ−ルクロロフェニルエ−テル等の多価アルコ−ルのアルキル及びアリ−ルエ−テル類、２−エチル−１，３ヘキサンジオール、２，２、４−トリメチル−１，３−ペンタンジオール、２，２ジメチル１，３プロパンジーオール等のジオール類、ポリオキシエチレンポリオキシプロピレンブロック共重合体、フッ素系界面活性剤、エタノ−ル、２−プロパノ−ル等の低級アルコ−ル類が挙げられるが、特に好ましいのは多価アルコールアルキルエーテルとしてジエチレングリコ−ルモノブチルエ−テル、炭素数６以上のジオールとして２−エチル−１，３ヘキサンジオール及び２，２，４−トリメチル１，３ペンタンジオールである。
【０１１７】
ジオール類は水不溶性色材の凝集が発生しにくいということで好適である。添加量はその種類や所望の物性にもよるが０．１重量％〜２０重量％、好ましくは０．５重量％〜１０重量％で範囲で添加される。下限未満では浸透性が不十分であり上限以上では粒子化特性に悪影響を及ぼす。またこれらの添加にうよりインクジェットヘッド部材や記録器具への濡れ性も改善され、充填性が向上し気泡による記録不良が発生しにくくなる。
【０１１８】
本発明おけるインク物性は、そのシステムにより適宜調整可能である。ここでインクの表面張力とは紙への浸透性を示す指標であり、特に表面形成されて１秒以下の短い時間での動的表面張力を測定することがインクの浸透性と対応する。飽和時間で測定される静的表面張力とは異なる。測定法としては特開昭６３−３１２３７２号公報等に記載の従来公知の方法で１秒以下の動的な表面張力を測定できる方法であればいずれも使用できる。表面張力の値は５０ｍＮ／ｍ以下が好ましく、より好ましくは４０ｍＮ／ｍ以下とすると優れた乾燥性が得られる。これに対してインクの吐出安定性からは動的な表面張力が低下しすぎると粒子化が不安定となりやすい。安定に吐出できる動的な表面張力は１ｍ秒において好ましくは４０ｍＮ／ｍ以上である。
【０１１９】
粘度の範囲としては１ｍＰａ・ｓから１０ｍＰａ・ｓの間で吐出方式により適宜選定される。
インク中の顔料粒子径範囲としては１０ｎｍ〜３００ｎｍのものを用い平均粒子径が６０ｎｍ〜１２０ｎｍとすることが好ましい。インク中の固形分両は１〜２５重量％、水分量は２５〜９３重量％の範囲、より好ましくは５０〜８０重量％の範囲である。
【０１２０】
本発明ではインク中の顔料インク、また着色微粒子インクの粒子表面のζ電位等の関係から分散安定性を損なわない電導度範囲として１ｍＳ／ｃｍ〜６ｍＳ／ｃｍの範囲とすると顔料の凝集等の発生を起さず長期に渡って粒子径の変化の少ない信頼性の高いインクとすることができる。この範囲とするには通常は電導度調整剤等の添加が行われる。好ましい電導度調整剤としてはテトラメチルアンモニウム塩化物等の第４級アンモニウム塩、アルカノールアミン塩等が挙げられる。
【０１２１】
本発明のインクには上記着色剤、溶媒の他に従来より知られている添加剤を加えることができる。
例えば、防腐防黴剤としてはデヒドロ酢酸ナトリウム、ソルビン酸ナトリウム、２−ピリジンチオ−ル−１−オキサイドナトリウム、安息香酸ナトリウム、ペンタクロロフェノ−ルナトリウム、イソチアゾリン等が本発明に使用できる。
【０１２２】
その他ｐＨ調整剤としては、調合されるインクに悪影響をおよぼさずにｐＨを７以上に調整できるものであれば、任意の物質を使用することができる。
その例として、ジエタノ−ルアミン、トリエタノ−ルアミン等のアミン、水酸化リチウム、水酸化ナトリウム等のアルカリ金属元素の水酸化物、水酸化アンモニウム、第４級アンモニウム水酸化物、第４級ホスホニウム水酸化物、炭酸リチウム、炭酸ナトリウム、炭酸カリウム等のアルカリ金属の炭酸塩等が挙げられる。
【０１２３】
キレ−ト試薬としては、例えば、エチレンジアミン四酢酸ナトリウム、ニトリロ三酢酸ナトリウム、ヒドロキシエチルエチレンジアミン三酢酸ナトリウム、ジエチレントリアミン五酢酸ナトリウム、ウラミル二酢酸ナトリウム等がある。
【０１２４】
防錆剤としては、例えば、酸性亜硫酸塩、チオ硫酸ナトリウム、チオジグリコ−ル酸アンモン、ジイソプロピルアンモニイウムニトライト、四硝酸ペンタエリスリト−ル、ジシクロヘキシルアンモニウムニトライト等がある。
【０１２５】
その他目的に応じて水溶性紫外線吸収剤、水溶性赤外線吸収剤、消泡剤を添加することもできる。
消泡剤としては、油脂系、脂肪酸系、脂肪酸エステル系、アルコール系、リン酸エステル系、アミン系、アミド系、金属石鹸系、硫酸エステル系、シリコーン系等が挙げられる。これらは単独でもまたは二種以上で用いることができる。この中でも、シロキサン結合を有するシリコーン系消泡剤が、インクタンクのスポンジ吸収体負圧制御の容易性から好ましい。特にポリエチレンオキサイド及び／又はポリプロピレンオキサイドを付加したポリシロキサン系消泡剤が有効である。
【０１２６】
インク中における消泡剤の含有量としては、０．００００１〜１０重量％、より好ましくは０．０００１〜５重量％であり、０．００００１重量％未満では十分な消泡効果を示さず、１０重量％を超えると着色材の溶解度や分散安定性が低下したり、インクの吐出安定性が低下する等の問題が生じる。また、インク吸収体のインク保持のためには、インク吸収体に用いるウレタン、或いはポリプロピレン繊維等からなるスポンジ吸収体の繊維密度、構造等と、これに対する消泡剤の親和性等から上記含有量の範囲内で最適な消泡剤量を決めれば良い。
【０１２７】
本発明９における２−アミノ−２−エチル−１，３−プロパンジオールはｐＨ調整剤である。また、本発明１０におけるＮ−シクロヘキシル−２−アミノエタンスルホン酸は緩衝剤である。更に、本発明１１におけるベンゾトリアゾールは防錆剤である。
【０１２８】
次に、上記した本発明の水性顔料インクを用いて記録を行うのに好適な、本発明のインクジェット記録装置の一例を以下に説明する。先ず、熱エネルギーを利用したインクジェット記録装置の主要部であるヘッド構成の一例を図１に示す。図１は、インク流路に沿ったヘッド１３の断面図であり、ヘッド１３はインクを通す流路（ノズル）１４を有するガラス、セラミック、シリコン又はプラスチック板等と発熱素子基板１５とを接着して得られる。発熱素子基板１５は酸化シリコン、窒化シリコン、炭化シリコン等で形成される保護層１６、アルミニウム、金、アルミニウム−銅合金等で形成される電極１７−１及び１７−２、ＨｆＢ_２、ＴａＮ、ＴａＡｌ等の高融点材料から形成される発熱抵抗体層１８、熱酸化シリコン、酸化アルミニウム等で形成される蓄熱層１９、シリコン、アルミニウム、窒化アルミニウム等の放熱性のよい材料で形成される基板２０よりなっている。
【０１２９】
上記ヘッド１３の電極１７−１及び１７−２にパルス状の電気信号が印加されると、発熱素子基板１５のｎで示される領域が急速に発熱し、この表面に接しているインク２１に気泡が発生し、その圧力でメニスカス２３が突出し、インク２１がヘッドのノズル１４を通して吐出し、吐出オリフィス２２よりインク小滴２４となり、被記録材２５に向かって飛翔する。
【０１３０】
図２に、このヘッドを組み込んだインクジェット記録装置の一例を示す。図２において、６１はワイピング部材としてのブレードであり、その一端はブレード保持部材によって保持固定されており、カンチレバーの形態をなす。ブレード６１は記録ヘッド６５による記録領域に隣接した位置に配置され、又、本例の場合、記録ヘッド６５の移動経路中に突出した形態で保持される。
【０１３１】
６２は記録ヘッド６５の突出口面のキャップであり、ブレード６１に隣接するホームポジションに配置され、記録ヘッド６５の移動方向と垂直な方向に移動して、インク吐出口面と当接し、キャッピングを行う構成を備える。更に、６３はブレード６１に隣接して設けられるインク吸収体であり、ブレード６１と同様、記録ヘッド６５の移動経路中に突出した形態で保持される。上記ブレード６１、キャップ６２及びインク吸収体６３によって吐出回復部６４が構成され、ブレード６１及びインク吸収体６３によって吐出口面に水分、塵埃等の除去が行われる。
【０１３２】
６５は、吐出エネルギー発生手段を有し、吐出口を配した吐出口面に対向する被記録材にインクを吐出して記録を行う記録ヘッド、６６は記録ヘッド６５を搭載して記録ヘッド６５の移動を行うためのキャリッジである。キャリッジ６６はガイド軸６７と摺動可能に係合し、キャリッジ６６の一部はモーター６８によって駆動されるベルト６９と接続している（図示されていない）。これによりキャリッジ６６はガイド軸６７に沿った移動が可能となり、記録ヘッド６５による記録領域及びその隣接した領域の移動が可能となる。
【０１３３】
５１は被記録材を挿入するための紙給部、５２は不図示のモーターにより駆動される紙送りローラーである。これらの構成により記録ヘッドの６５吐出口面と対向する位置へ被記録材が給紙され、記録が進行するにつれて排紙ローラー５３を配した排紙部へ排紙される。以上の構成において記録ヘッド６５が記録終了してホームポジションへ戻る際、吐出回復部６４のキャップ６２は記録ヘッド６５の移動経路から退避しているが、ブレード６１は移動経路中に突出している。その結果、記録ヘッド６５の吐出口がワイピングされる。
【０１３４】
尚、キャップ６２が記録ヘッド６５の吐出面に当接してキャッピングを行う場合、キャップ６２は記録ヘッドの移動経路中に突出するように移動する。記録ヘッド６５がホームポジションから記録開始位置へ移動する場合、キャップ６２及びブレード６１は上記したワイピングの時の位置と同一の位置にある。この結果、この移動においても記録ヘッド６５の吐出口面はワイピングされる。上述の記録ヘッドのホームポジションへの移動は、記録終了時や吐出回復時ばかりでなく、記録ヘッドが記録のために記録領域を移動する間に所定の間隔で記録領域に隣接したホームポジションへ移動し、この移動に伴って上記ワイピングが行われる。
【０１３５】
図３は、記録ヘッドにインク供給部材、例えば、チューブを介して供給されるインクを収容したインクカートリッジの一例を示す図である。ここで４０は供給用インクを収納したインク収容部、例えば、インク袋であり、その先端にはゴム製の栓４２が設けられている。この栓４２に針（不図示）を挿入することにより、インク袋４０中のインクをヘッドに供給可能にする。４４は廃インクを受容するインク吸収体である。インク収容部としてはインクとの接液面がポリオレフィン、特にポリエチレンで形成されているものが好ましい。
【０１３６】
本発明で使用されるインクジェット記録装置としては、上述のようにヘッドとインクカートリッジとが別体となったものに限らず、図４に示すようなそれらが一体になったものにも好適に用いられる。図４において、７０は記録ユニットであり、この中にはインクを収容したインク収容部、例えば、インク吸収体が収納されており、かかるインク吸収体中のインクが複数オリフィスを有するヘッド部７１から液滴として吐出される構成になっている。インク吸収体の材料としてはポリウレタン、セルロース、ポリビニルアセテート又はポリオレフィン系樹脂を用いることが本発明にとって好ましい。又、インク吸収体を用いず、インク収容部が内部にバネ等を仕込んだインク袋であるような構造でもよい。７２はカートリッジ内部を大気に連通させるための大気連通口である。この記録ユニット７０は図２に示す記録ヘッド６５に換えて用いられるものであって、キャリッジ６６に対して着脱自在になっている。
【０１３７】
次に、力学的エネルギーを利用したインクジェット記録装置の好ましい一例としては、複数のノズルを有するノズル形成基板と、ノズルに対向して配置される圧電材料と導電材料からなる圧力発生素子と、この圧力発生素子の周囲を満たすインクを備え、印加電圧により圧力発生素子を変位させ、インクの小液滴をノズルから吐出させるオンデマンドインクジェット記録装置を挙げることができる。その記録装置の主要部である記録ヘッドの構成の一例を図５に示す。
【０１３８】
ヘッドは、図示されていないインク室に連通したインク流路８０と、所望の体積のインク滴を吐出するためのオリフィスプレート８１と、インクに直接圧力を作用させる振動板８２と、この振動板８２に接合され、電気信号により変位する圧電素子８３と、オリフィスプレート８１、振動板８２等を支持固定するための基板８４とから構成されている。
【０１３９】
図５において、インク流路８０は、感光性樹脂等で形成され、オリフィスプレート８１は、ステンレス、ニッケル等の金属を電鋳やプレス加工による穴あけ等により吐出口８５が形成され、表面にＰＴＦＥニッケルの共析メッキ等の撥インク層が設けられている。振動板８２はステンレス、ニッケル、チタン等の金属フィルム及び高弾性樹脂フィルム等で形成され、圧電素子８３は、チタン酸バリウム、ＰＺＴ等の誘電体材料で形成される。以上のような構成の記録ヘッドは、圧電素子８３にパルス状の電圧を与え、歪み応力を発生させ、そのエネルギーが圧電素子８３に接合された振動板を変形させ、インク流路８０内のインクを垂直に加圧しインク滴（不図示）をオリフィスプレート８１の吐出口８５より吐出して記録を行うように動作する。このような記録ヘッドは、図４に示したものと同様なインクジェット記録装置に組み込んで使用される。インクジェット記録装置の細部の動作は、先述と同様に行うもので差しつかえない。
【０１４０】
次に他の力学的エネルギーを利用したインクジェット記録装置の好ましい一例として静電アクチュエータを用いたインクジェットを示す。図１は本発明を適用したインクジェットヘッドの断面図であこれらの図に示すように、インクジェッドヘッド１は、シリコン基板２を挟み、上側に同じくシリコン製のノズルプレート３、下側にシリコンと熱膨張率が近いホウ珪酸ガラス基板４がそれぞれ積層された３層構造となっている。中央のシリコン基板２には、それぞれ独立した複数のインク室５、これらに共通に設けられた共通インク室６及びこの共通インク室６を複数のインク室５にそれぞれ接続しているインク供給路７としてそれぞれ機能する溝が、その表面（図中、上面）からエッチングを施すことにより形成されている。これらの溝がノズルプレート３によって塞がれて、各部分５、６、７が区画形成されている。
【０１４１】
ノズルプレート３には、各インク室５の先端側の部分に対応する位置に、インクノズル１１が形成されており、これらが各インク室５に連通している。また、ノズルプレート３には共通インク室６に連通するインク供給口が形成されている。インクは、外部の図示しないインクタンクから、インク供給口を通って共通インク室６に供給される。共通インク室６に供給されたインクは、インク供給路７を通って、互いに独立したインク室５にそれぞれ供給される。
【０１４２】
インク室５は、その底壁８が図１の上下方向に弾性変位可能なダイヤフラムとして機能するように薄肉に形成されている。したがって、この底壁８の部分を、以後の説明の都合上、ダイヤフラム８と称して説明することもある。
【０１４３】
次に、シリコン基板２の下面に接しているガラス基板４においては、その上面、即ちシリコン基板２との接合面には、シリコン基板２の各インク室５に対応した位置に、浅くエッチングされた凹部９が形成されている。したがって、各インク室５の底壁８は、非常に僅かの隙間を隔てて、ガラス基板４の凹部９の表面９２と対峙している。なお、ガラス基板４の凹部９はインク室５の底壁８に対向しているので、振動板対向壁あるいは単に対向壁９１と称する。
【０１４４】
ここで、各インク室５の底壁８は、それぞれ電荷を蓄えるための電極として機能する。そして、各インク室５の底壁８に対峙するように、ガラス基板４の凹部表面９２には、セグメント電極１０が形成されている。各セグメント電極１０の表面は無機ガラスからなる厚さＧ０の絶縁層により覆われている。このように、セグメント電極１０と各インク室底壁８とは、絶縁層１５を挟んで互いに対向電極（電極間距離をＧとする）を形成している。
【０１４５】
以下に本発明の実施例および比較例を示す。
【実施例１】
（ブラックインク１の調製）
【０１４６】
下記組成物を用いて混合し１日放置後、水酸化リチウムでｐＨを９にして０．５μｍポリプロピレンフィルターにて濾過し［ブラックインク１］とした。
【０１４７】
カーボン分散液１ （インク中固形分濃度として）１０重量％
２−メチル−２，４−ペンタンジオール １５重量％
グリセロ−ル １５重量％
２−エチル−１，３ヘキサンジオール １重量％
Ｎ−ヒドロキシエチルピロリドン ５重量％
具体例（ＩＩ−２）の活性剤 １重量％
デヒドロ酢酸ナトリウム ０．２重量％
２−アミノ−２−エチル−１，３−プロパンジオール ０．６重量％
Ｎ−シクロヘキシル−２−アミノエタンスルホン酸 ０．０５重量％
ベンゾトリアゾール ０．０５重量％
消泡剤（ＫＭ−７２Ｆ） ０．１重量％
高純水（１０ＭΩ） 残量
【０１４８】
得られたブラックインク１について、遠心式限外濾過ユニット（ウルトラフリー１５／分画分子量１万）（日本ミリポア社製）を用いて、液体成分と顔料とを分離し、該液体成分についてはイオンクロマトグラフＤＸ−５００（日本ダイオネクス株式会社製）を用いて、その遊離アニオン濃度を測定した。遊離アニオン濃度、すなわち塩素イオン濃度は１０ｐｐｍ以下であった。
以下分散液、染料の濃度はインク中の色材固形分濃度である。
【０１４９】
【実施例２】
（ブラックインク２の調製）
下記組成物を用いる以外は実施例１と同様にし、水酸化リチウムにてｐＨ８．８にして［ブラックインク２］を調製した。
【０１５０】
カーボン分散液２ １０重量％
２−メチル−２，４−ペンタンジオール １４重量％
１，２，６−ヘキサントリオール ８重量％
１，５−ペンタンジオ−ル ８重量％
２−エチル−１，３−ヘキサンジオール ２重量％
２−ピロリドン ８重量％
具体例（ＩＩ−３）の活性剤 １．０重量％
具体例（ＩＩＩ−１）の活性剤 １．２重量％
尿素 ５重量％
２−ピリジンチオ−ル−１−オキサイドナトリウム ０．２重量％
２−アミノ−２−エチル−１，３−プロパンジオール ０．６重量％
Ｎ−シクロヘキシル−２−アミノエタンスルホン酸 ０．０５重量％
ベンゾトリアゾール ０．０５重量％
消泡剤（ＫＭ−７２Ｆ） ０．１重量％
高純水（１０ＭΩ） 残量
【０１５１】
得られたブラックインク２について、遠心式限外濾過ユニット（ウルトラフリー１５／分画分子量１万）（日本ミリポア社製）を用いて、液体成分と顔料とを分離し、該液体成分についてはイオンクロマトグラフＤＸ−５００（日本ダイオネクス株式会社製）を用いて、その遊離アニオン濃度を測定した。遊離アニオン濃度、すなわち硫酸イオン濃度は１００ｐｐｍ以下であった。
【０１５２】
【実施例３】
（ブラックインク３の調製）
下記組成物を用いる以外は実施例１と同様にして、ｐＨを水酸化リチウムで９．５にして［ブラックインク３］を調製した。
カーボン分散液３ １２重量％
【０１５３】
２−メチル−２，４−ペンタンジオール ２０重量％
ジエチレングリコ−ル ５重量％
グリセロ−ル ５重量％
２−エチル−１，３−ヘキサンジオール ３重量％
２−ピロリドン ２重量％
スチレンアクリル酸重合体 ０．５重量％
（ＩＩ−２）の界面活性剤 １重量％
（ＶＩ）の活性剤 Ｒ：Ｃ_９Ｈ_１９ ｋ：１２ １重量％
デヒドロ酢酸ナトリウム ０．２重量％
２−アミノ−２−エチル−１，３−プロパンジオール ０．６重量％
Ｎ−シクロヘキシル−２−アミノエタンスルホン酸 ０．０５重量％
ベンゾトリアゾール ０．０５重量％
消泡剤（ＫＭ−７２Ｆ） ０．１重量％
イオン交換水 残量
【０１５４】
得られたブラックインク３について、遠心式限外濾過ユニット（ウルトラフリー１５／分画分子量１万）（日本ミリポア社製）を用いて、液体成分と顔料とを分離し、該液体成分についてはイオンクロマトグラフＤＸ−５００（日本ダイオネクス株式会社製）を用いて、その遊離アニオン濃度を測定した。遊離アニオン濃度、すなわち硝酸イオン濃度は１０ｐｐｍ以下であった。
【０１５５】
【実施例４】
（イエローインク１、マゼンタインク１、シアンインク１の調製）
＜イエローインク１＞
下記組成物を用いる以外は実施例１と同様にして、ｐＨを水酸化リチウムで９．５にして［イエローインク１］を調製した。
【０１５６】
イエロー分散液１ １０重量％
２−メチル−２，４−ペンタンジオール １３重量％
エチレングリコ−ル ５重量％
グリセロ−ル ２重量％
１，５−ペンタンジオール ８重量％
２−エチル−１，３−ヘキサンジオール ３重量％
２−ピロリドン ２重量％
ポリオキシエチレンポリオキシエチレンブロック共重合体 １重量％
具体例（ＩＩ−４）の活性剤 １重量％
具体例（Ｖ）の活性剤 ｐ、ｑ＝２０ ０．８重量％
尿素 ５重量％
安息香酸ナトリウム ０．２重量％
２−アミノ−２−エチル−１，３−プロパンジオール ０．６重量％
Ｎ−シクロヘキシル−２−アミノエタンスルホン酸 ０．０５重量％
ベンゾトリアゾール ０．０５重量％
消泡剤（ＫＭ−７２Ｆ） ０．１重量％
イオン交換水 残量
【０１５７】
＜マゼンタインク１＞
下記組成物を用いる以外は実施例１と同様にして、ｐＨを水酸化リチウムで９．１にして［マゼンタインク１］を調製した。
【０１５８】
マゼンタ分散液１ １０重量％
２−メチル−２，４−ペンタンジオール １５重量％
エチレングリコ−ル ５重量％
グリセロ−ル １５重量％
２−エチル−１，３−ヘキサンジオール ３重量％
２−ピロリドン ２重量％
ポリオキシエチレンポリオキシエチレンブロック共重合体 １重量％
具体例（ＩＩ−４）の活性剤 １重量％
具体例（Ｖ）の活性剤 ｐ、ｑ＝２０ ０．８重量％
尿素 ５重量％
安息香酸ナトリウム ０．２重量％
２−アミノ−２−エチル−１，３−プロパンジオール ０．６重量％
Ｎ−シクロヘキシル−２−アミノエタンスルホン酸 ０．０５重量％
ベンゾトリアゾール ０．０５重量％
消泡剤（ＫＭ−７２Ｆ） ０．１重量％
イオン交換水 残量
【０１５９】
＜シアンインク１＞
下記組成物を用いる以外は実施例１と同様にして、水酸化リチウムでｐＨを９．２にして［シアンインク１］を調製した。
【０１６０】
シアン分散液１ １０重量％
２−メチル−２，４−ペンタンジオール １５重量％
グリセロ−ル １５重量％
２−エチル−１，３−ヘキサンジオール １重量％
Ｎーヒドロキシエチルピロリドン ５重量％
具体例（ＩＩ−２）の活性剤 １重量％
デヒドロ酢酸ナトリウム ０．２重量％
２−アミノ−２−エチル−１，３−プロパンジオール ０．６重量％
Ｎ−シクロヘキシル−２−アミノエタンスルホン酸 ０．０５重量％
ベンゾトリアゾール ０．０５重量％
消泡剤（ＫＭ−７２Ｆ） ０．１重量％
高純水（１０ＭΩ） 残量
【０１６１】
【実施例５】
（イエローインク２、マゼンタインク２、シアンインク２の調製）
＜イエローインク２＞
下記組成物を用いる以外は実施例１と同様にして、ｐＨを水酸化ナトリウムで７．８にして［イエローインク２］を調製した。
【０１６２】
イエロー分散液２ １０重量％
２−メチル−２，４−ペンタンジオール １５重量％
トリエチレングリコ−ル ５重量％
ペトリオ−ル １０重量％
２−エチル−１，３−ヘキサンジオール ３重量％
Ｎ−メチルー２ーピロリドン ５重量％
ジエチレングリコールモノブチルエーテル ２重量％
具体例（ＩＶ）の活性剤 Ｒ：Ｃ_１０Ｈ_２１ Ｋ：７ １重量％
ヒドロキシエチル尿素 ５重量％
２−ピリジンチオ−ル−１−オキサイドナトリウム ０．２重量％
イオン交換水 残量
【０１６３】
＜マゼンタインク２＞
下記組成物を用いる以外は実施例１と同様にして、水酸化ナトリウムでｐＨを８．５にして［マゼンタインク２］を調製した。
【０１６４】
マゼンタ分散液２ １０重量％
２−メチル−２，４−ペンタンジオール １５重量％
トリエチレングリコ−ル ５重量％
ペトリオ−ル １０重量％
２−エチル−１，３−ヘキサンジオール ３重量％
Ｎ−メチルー２ーピロリドン ５重量％
ジエチレングリコールモノブチルエーテル ２重量％
具体例（ＩＶ）の活性剤 Ｒ：Ｃ_１０Ｈ_２１ Ｋ：７ １重量％
ヒドロキシエチル尿素 ５重量％
２−ピリジンチオ−ル−１−オキサイドナトリウム ０．２重量％
イオン交換水 残量
【０１６５】
＜シアンインク２＞
下記組成物を用いる以外は実施例１と同様にして、水酸化ナトリウムでｐＨを８．２にして［シアンインク２］を調製した。
【０１６６】
シアン分散液２ １０重量％
２−メチル−２，４−ペンタンジオール １５重量％
トリエチレングリコ−ル ５重量％
ペトリオ−ル １０重量％
２−エチル−１，３−ヘキサンジオール ３重量％
Ｎ−メチルー２ーピロリドン ５重量％
ジエチレングリコールモノブチルエーテル ２重量％
具体例（Ｖ）の活性剤 Ｒ：Ｃ_１０Ｈ_２１ Ｋ：７ １重量％
ヒドロキシエチル尿素 ５重量％
２−ピリジンチオ−ル−１−オキサイドナトリウム ０．２重量％
イオン交換水 残量
【０１６７】
【実施例６】
（イエローインク３、マゼンタインク３、シアンインク３の調製）
＜イエローインク３＞
下記組成物を用いる以外は実施例１と同様にして、ｐＨを水酸化リチウムで８にして［イエローインク３］を調製した。
【０１６８】
イエロー分散液３ １１重量％
２−メチル−２，４−ペンタンジオール ２０重量％
グリセロ−ル ７重量％
１、３−ブタンジオール ３重量％
２−エチル−１，３−ヘキサンジオール ３重量％
２−ピロリドン ８重量％
具体例（ＩＩ−１）の活性剤 ０．３重量％
（ＩＶ）活性剤 ｐ＋ｑ＝１５ ０．５重量％
（ＩＶ）活性剤 ｐ＋ｑ＝０ ０．５重量％
ヒドロキシエチル尿素 ５重量％
デヒドロ酢酸ナトリウム ０．２重量％
イオン交換水 残量
【０１６９】
＜マゼンタインク３＞
下記組成物を用いる以外は実施例１と同様にして、ｐＨを水酸化リチウムで８にして［マゼンタインク３］を調製した。
【０１７０】
マゼンタ分散液３ １１重量％
２−メチル−２，４−ペンタンジオール ２０重量％
グリセロ−ル ７重量％
１、３ブタンジオール ３重量％
２−エチル−１，３−ヘキサンジオール ３重量％
２−ピロリドン ８重量％
（ＩＶ）活性剤 ｐ＋ｑ＝１５ ０．５重量％
（ＩＶ）活性剤 ｐ＋ｑ＝０ ０．５重量％
ヒドロキシエチル尿素 ５重量％
デヒドロ酢酸ナトリウム ０．２重量％
イオン交換水 残量
【０１７１】
＜シアンインク３＞
下記組成物を用いる以外は実施例１と同様にして、ｐＨを水酸化リチウムで８にして［シアンインク３］を調製した。
【０１７２】
シアン分散液３ １１重量％
２−メチル−２，４−ペンタンジオール ２０重量％
グリセロ−ル ７重量％
１、３ブタンジオール ３重量％
２−エチル−１，３−ヘキサンジオール ３重量％
２−ピロリドン ８重量％
具体例（ＩＩ−１）の活性剤 ０．３重量％
テトラメチルアンモニウム硝酸塩（電導度調整剤） ０．４重量％
（ＩＶ）活性剤 ｐ＋ｑ＝１５ ０．５重量％
（ＩＶ）活性剤 ｐ＋ｑ＝０ ０．５重量％
ヒドロキシエチル尿素 ５重量％
デヒドロ酢酸ナトリウム ０．２重量％
イオン交換水 残量
【０１７３】
【実施例７】
（イエローインク４、マゼンタインク４、シアンインク４の調製）
＜イエローインク４＞
下記組成物を用いる以外は実施例１と同様にして、ｐＨを水酸化リチウムで９．５にして［イエローインク４］を調製した。
【０１７４】
イエロー分散液４ １２重量％
２−メチル−２，４−ペンタンジオール １５重量％
エチレングリコ−ル ５重量％
グリセロ−ル ２重量％
１，３−プロパンジオール ８重量％
２−エチル−１，３−ヘキサンジオール ３重量％
２−ピロリドン ２重量％
ポリオキシエチレンポリオキシエチレンブロック共重合体 １重量％
具体例（ＩＩ−４）の活性剤 ０．５重量％
尿素 ５重量％
安息香酸ナトリウム ０．２重量％
イオン交換水 残量
【０１７５】
＜マゼンタインク４＞
下記組成物を用いる以外は実施例１と同様にして、ｐＨを水酸化リチウムで９．１にして［マゼンタインク４］を調製した。
【０１７６】
マゼンタ分散液４ １２重量％
２−メチル−２，４−ペンタンジオール １０重量％
エチレングリコ−ル ５重量％
グリセロ−ル １５重量％
２−エチル−１，３−ヘキサンジオール ３重量％
２−ピロリドン ２重量％
ポリオキシエチレンポリオキシエチレンブロック共重合体 １重量％
具体例（ＩＩ−４）の活性剤 ０．３重量％
具体例（Ｖ）の活性剤 ｐ、ｑ＝２０ ０．２重量％
尿素 ５重量％
安息香酸ナトリウム ０．２重量％
イオン交換水 残量
【０１７７】
＜シアンインク４＞
下記組成物を用いる以外は実施例１と同様にして、ｐＨを水酸化リチウムで８．４にして［シアンインク４］を調製した。
【０１７８】
シアン分散液４ １２重量％
２−メチル−２，４−ペンタンジオール １５重量％
グリセロ−ル １５重量％
２−エチル−１，３−ヘキサンジオール １重量％
Ｎーヒドロキシエチルピロリドン ５重量％
具体例（ＩＩ−２）の活性剤 １重量％
デヒドロ酢酸ナトリウム ０．２重量％
高純水（１０ＭΩ） 残量
【０１７９】
【実施例８】
（イエローインク５、マゼンタインク５、シアンインク５、ブラックインク４の調製）
＜イエローインク５＞
【０１８０】
下記組成物を用いる以外は実施例１と同様にして、ｐＨを水酸化ナトリウムで７．８にして［イエローインク５］を調製した。
【０１８１】
具体例Ｙ１の染料 ５重量％
具体例Ｙ２の染料 ５重量％
乳酸 １重量％
２−メチル−２，４−ペンタンジオール １８重量％
１、５ペンタンジオール ５重量％
トリメチロールプロパン ７重量％
２−エチル−１，３−ヘキサンジオール ３重量％
２ーピロリドン ５重量％
ジエチレングリコールモノブチルエーテル ２重量％
具体例（ＩＶ）活性剤 ｐ＋ｑ＝１５ ０．５重量％
具体例（ＩＶ）の活性剤 Ｒ：Ｃ_１０Ｈ_２１ Ｋ：７ １重量％
ヒドロキシエチル尿素 ２重量％
２−ピリジンチオ−ル−１−オキサイドナトリウム ０．２重量％
イオン交換水 残量
【０１８２】
＜マゼンタインク５＞
下記組成物を用いる以外は実施例１と同様にして、ｐＨを水酸化リチウムで７．８にして［マゼンタインク５］を調製した。
【０１８３】
具体例Ｍ５の染料 ６重量％
Ｃ．Ｉ．アシッドレッド５２ ４重量％
２−メチル−２，４−ペンタンジオール １８重量％
１、５ペンタンジオール ５重量％
トリメチロールプロパン ７重量％
２−エチル−１，３−ヘキサンジオール ３重量％
２ーピロリドン ５重量％
ジエチレングリコールモノブチルエーテル ２重量％
（ＩＶ）活性剤 ｐ＋ｑ＝１５ ０．５重量％
具体例（Ｖ）の活性剤 Ｒ：Ｃ_１０Ｈ_２１ Ｋ：７ １重量％
ヒドロキシエチル尿素 ５重量％
２−ピリジンチオ−ル−１−オキサイドナトリウム ０．２重量％
イオン交換水 残量
【０１８４】
＜シアンインク５＞
下記組成物を用いる以外は実施例１と同様にして、ｐＨを水酸化リチウムで８にして［シアンインク５］を調製した。
【０１８５】
具体例Ｃ１ ４重量％
具体例Ｃ２ ４重量％
アシッドブルー９ ２重量％
硝酸カルシウム ６重量％
２−メチル−２，４−ペンタンジオール １８重量％
トリエチレングリコ−ル ５重量％
トリメチロールプロパン ７重量％
２−エチル−１，３−ヘキサンジオール ３重量％
２ーピロリドン ５重量％
ジエチレングリコールモノブチルエーテル ２重量％
（ＩＶ）活性剤 ｐ＋ｑ＝１５ ０．５重量％
具体例（ＩＶ）の活性剤 Ｒ：Ｃ_１０Ｈ_２１ Ｋ：７ １重量％
ヒドロキシエチル尿素 １重量％
２−ピリジンチオ−ル−１−オキサイドナトリウム ０．２重量％
イオン交換水 残量
【０１８６】
＜ブラックインク４＞
下記組成物を用いる以外は実施例１と同様にして、ｐＨを水酸化リチウムで８にして［ブラックインク４］を調製した。
【０１８７】
具体例の染料ＢＫ１ ５重量％
具体例の染料Ｙ４ ５重量％
硝酸カルシウム ６重量％
２−メチル−２，４−ペンタンジオール １８重量％
トリエチレングリコ−ル ５重量％
トリメチロールプロパン ７重量％
２−エチル−１，３−ヘキサンジオール ３重量％
２ーピロリドン ５重量％
ジエチレングリコールモノブチルエーテル ２重量％
（ＩＶ）活性剤 ｐ＋ｑ＝１５ ０．５重量％
具体例（Ｖ）の活性剤 Ｒ：Ｃ_１０Ｈ_２１ Ｋ：７ １重量％
ヒドロキシエチル尿素 １重量％
２−ピリジンチオ−ル−１−オキサイドナトリウム ０．２重量％
イオン交換水 残量
【０１８８】
【実施例９】
（イエローインク６、マゼンタインク６、シアンインク６の調製）
＜イエローインク６＞
下記組成物を用いる以外は実施例１と同様にして、ｐＨを水酸化リチウムで７．２にして［イエローインク６］を調製した。
【０１８９】
具体例の染料Ｙ４ ５重量％
具体例の染料Ｙ５ ５重量％
２−メチル−２，４−ペンタンジオール ２３重量％
グリセロ−ル ７重量％
２−エチル−１，３−ヘキサンジオール ３重量％
２−ピロリドン ８重量％
トリエチレングリコールモノブチルエーテエル １０重量％
（ＩＶ）活性剤 ｐ＋ｑ＝１５ ０．５重量％
（ＩＶ）活性剤 ｐ＋ｑ＝０ ０．５重量％
尿素 ２重量％
デヒドロ酢酸ナトリウム ０．２重量％
イオン交換水 残量
【０１９０】
＜マゼンタインク６＞
下記組成物を用いる以外は実施例１と同様にして、ｐＨを水酸化リチウムで８．１にして［マゼンタインク６］を調製した。
【０１９１】
具体例Ｍ１の染料 ６重量％
具体例Ｍ２の染料 ４重量％
２−メチル−２，４−ペンタンジオール １３重量％
グリセロ−ル ７重量％
２−エチル−１，３−ヘキサンジオール ３重量％
２−ピロリドン ８重量％
トリエチレングリコールモノブチルエーテル ３重量％
（ＩＶ）活性剤 ｐ＋ｑ＝１５ ０．５重量％
（ＩＶ）活性剤 ｐ＋ｑ＝０ ０．５重量％
ヒドロキシエチル尿素 ５重量％
デヒドロ酢酸ナトリウム ０．２重量％
イオン交換水 残量
【０１９２】
＜シアンインク６＞
下記組成物を用いる以外は実施例１と同様にして、ｐＨを水酸化リチウムで９．５にしてシアンインク６を調製した。
【０１９３】
具体例Ｃ２の染料 ６重量％
具体例Ｃ３の染料 ４重量％
２−メチル−２，４−ペンタンジオール ２３重量％
グリセロ−ル ７重量％
２−エチル−１，３−ヘキサンジオール ３重量％
２−ピロリドン ８重量％
トリエチレングリコールモノブチルエーテル ３重量％
（ＩＶ）活性剤 ｐ＋ｑ＝１５ ０．５重量％
（ＩＶ）活性剤 ｐ＋ｑ＝０ ０．５重量％
ヒドロキシエチル尿素 ５重量％
デヒドロ酢酸ナトリウム ０．２重量％
イオン交換水 残量
【０１９４】
【実施例１０】
（イエローインク７、マゼンタインク７、シアンインク７の調製）
＜イエローインク７＞
下記組成物を用いる以外は実施例１と同様にして、ｐＨを水酸化リチウムで９．５にして［イエローインク７］を調製した。
【０１９５】
具体例の染料Ｙ７ ４重量％
具体例の染料Ｙ６ ３重量％
Ｃ．Ｉ．アシッドイエロー１７ ３重量％
２−メチル−２，４−ペンタンジオール ２３重量％
グリセロ−ル ７重量％
２−エチル−１，３−ヘキサンジオール ３重量％
２−ピロリドン ８重量％
トリエチレングリコールモノブチルエーテエル １０重量％
（ＩＶ）活性剤 ｐ＋ｑ＝１５ ０．５重量％
（ＩＶ）活性剤 ｐ＋ｑ＝０ ０．５重量％
尿素 ２重量％
デヒドロ酢酸ナトリウム ０．２重量％
イオン交換水 残量
【０１９６】
＜マゼンタインク７＞
下記組成物を用いる以外は実施例１と同様にして、ｐＨを水酸化リチウムで９．５にして［マゼンタインク７］を調製した。
【０１９７】
具体例Ｍ１の染料 ５重量％
具体例Ｍ２の染料 ５重量％
２−メチル−２，４−ペンタンジオール ２３重量％
グリセロ−ル ７重量％
２−エチル−１，３−ヘキサンジオール ３重量％
２−ピロリドン ８重量％
トリエチレングリコールモノブチルエーテル ３重量％
（ＩＶ）活性剤 ｐ＋ｑ＝１５ ０．５重量％
（ＩＶ）活性剤 ｐ＋ｑ＝０ ０．５重量％
ヒドロキシエチル尿素 ５重量％
デヒドロ酢酸ナトリウム ０．２重量％
イオン交換水 残量
【０１９８】
＜シアンインク７＞
下記組成物を用いる以外は実施例１と同様にして、ｐＨを水酸化リチウムで９．５にして［シアンインク７］を調製した。
【０１９９】
具体例Ｃ３の染料 ６重量％
具体例Ｃ２の染料 ４重量％
硝酸カルシウム １重量％
２−メチル−２，４−ペンタンジオール ２３重量％
グリセロ−ル ７重量％
１、３ブタンジオール ３重量％
２−エチル−１，３−ヘキサンジオール ３重量％
２−ピロリドン ８重量％
（ＩＶ）活性剤 ｐ＋ｑ＝１５ ０．５重量％
（ＩＶ）活性剤 ｐ＋ｑ＝０ ０．５重量％
ヒドロキシエチル尿素 ５重量％
デヒドロ酢酸ナトリウム ０．２重量％
イオン交換水 残量
【０２００】
【比較例１】
（ブラックインク５の調製）
実施例１において、２−メチル−２，４−ペンタンジオール、２−エチル−１，３−ヘキサンジオール、２−アミノ−２−エチル−１，３−プロパンジオール、Ｎ−シクロヘキシル−２−アミノエタンスルホン酸、ベンゾトリアゾール、消泡剤を除き、遊離アニオンとして混入している塩素イオンを塩化カリウムの形で加えて、遊離アニオン濃度、すなわち塩素イオン濃度を約８００ｐｐｍに調整した以外は同様にして［ブラックインク５］とした。
【０２０１】
【比較例２】
（ブラックインク６の調製）
実施例２において、２−メチル−２，４−ペンタンジオール、２−エチル−１，３−ヘキサンジオール、２−アミノ−２−エチル−１，３−プロパンジオール、Ｎ−シクロヘキシル−２−アミノエタンスルホン酸、ベンゾトリアゾール、消泡剤を除き、遊離アニオンとして混入している硫酸イオンを硫酸カリウムの形で加えて、遊離アニオン濃度、すなわち硫酸イオン濃度を約８００ｐｐｍに調整した以外は同様にして［ブラックインク６］とした。
【０２０２】
【比較例３】
（ブラックインク７の調製）
実施例３において、２−メチル−２，４−ペンタンジオール、２−エチル−１，３−ヘキサンジオール、２−アミノ−２−エチル−１，３−プロパンジオール、Ｎ−シクロヘキシル−２−アミノエタンスルホン酸、ベンゾトリアゾール、消泡剤を除き、遊離アニオンとして混入している硝酸イオンを硝酸カリウムの形で加えて、遊離アニオン濃度、すなわち硝酸イオン濃度を約８００ｐｐｍに調整した以外は同様にして［ブラックインク７］とした。
【０２０３】
【比較例４】
（イエローインク８、マゼンタインク８、シアンインク８の調製）
実施例４においてイエローインク１の２−メチル−２，４−ペンタンジオール、２−エチル−１，３−ヘキサンジオール、２−アミノ−２−エチル−１，３−プロパンジオール、Ｎ−シクロヘキシル−２−アミノエタンスルホン酸、ベンゾトリアゾール、消泡剤を除いた以外は同様にして［イエローインク８］とした。マゼンタインク１の２−メチル−２，４−ペンタンジオール、２−エチル−１，３−ヘキサンジオール、２−アミノ−２−エチル−１，３−プロパンジオール、Ｎ−シクロヘキシル−２−アミノエタンスルホン酸、ベンゾトリアゾール、消泡剤を除いた以外は同様にして［マゼンタインク８］とした。
同様にシアンインク１の２−メチル−２，４−ペンタンジオール、 ２−エチル−１，３−ヘキサンジオール、２−アミノ−２−エチル−１，３−プロパンジオール、Ｎ−シクロヘキシル−２−アミノエタンスルホン酸、ベンゾトリアゾール、消泡剤を除いた以外は同様にして［シアンインク８］とした。
【０２０４】
【比較例５】
（イエローインク９、マゼンタインク９、シアンインク９の調製）
実施例５のイエローインク２において、２−メチル−２，４−ペンタンジオールと２−エチル−１，３−ヘキサンジオールを除いた以外は同様にして［イエローインク９］とした。
同様にマゼンタインク２において、２−メチル−２，４−ペンタンジオールと２−エチル−１，３−ヘキサンジオールを除いた以外は同様にして［マゼンタインク９］とした。
同様にシアンインク３において、２−メチル−２，４−ペンタンジオールと２−エチル−１，３−ヘキサンジオールを除いた以外は同様にして［シアンインク９］とした。
【０２０５】
【比較例６】
（イエローインク１０、マゼンタインク１０、シアンインク１０の調製）
実施例６のイエローインク３において、２−メチル−２，４−ペンタンジオールと２−エチル−１，３−ヘキサンジオールを除いた以外は同様にして［イエローインク１０］とした。
同様にマゼンタインク３において、２−メチル−２，４−ペンタンジオールと２−エチル−１，３−ヘキサンジオールを除いた以外は同様にして［マゼンタインク１０］とした。
同様にシアンインク３において、２−メチル−２，４−ペンタンジオールと２−エチル−１，３−ヘキサンジオールを除いた以外は同様にして［シアンインク１０］とした。
【０２０６】
【比較例７】
（イエローインク１１、マゼンタインク１１、シアンインク１１の調製）
実施例７のイエローインク４において、２−メチル−２，４−ペンタンジオールと２−エチル−１，３−ヘキサンジオールを除いた以外は同様にして［イエローインク１１］とした。
同様にマゼンタインク４において、２−メチル−２，４−ペンタンジオールと２−エチル−１，３−ヘキサンジオールを除いた以外は同様にして［マゼンタインク１１］とした。
同様にシアンインク４において、２−メチル−２，４−ペンタンジオールと２−エチル−１，３−ヘキサンジオールを除いた以外は同様にして［シアンインク１１］とした。
【０２０７】
【比較例８】
（イエローインク１２、マゼンタインク１２、シアンインク１２の調製）
【０２０８】
実施例８のイエローインク５において、２−メチル−２，４−ペンタンジオールと２−エチル−１，３−ヘキサンジオールを除いた以外は同様にして［イエローインク１２］とした。
同様にマゼンタインク５において、２−メチル−２，４−ペンタンジオールと２−エチル−１，３−ヘキサンジオールを除いた以外は同様にして［マゼンタインク１２］とした。
同様にシアンインク５において、２−メチル−２，４−ペンタンジオールと２−エチル−１，３−ヘキサンジオールを除いた以外は同様にして［シアンインク１２］とした。
同様にブラックインク４において、２−メチル−２，４−ペンタンジオールと２−エチル−１，３−ヘキサンジオールを除いた以外は同様にして［ブラックインク８］とした。
【０２０９】
【比較例９】
（イエローインク１３、マゼンタインク１３、シアンインク１３の調製）
【０２１０】
実施例６のイエローインク６において、イエロー分散液３の配合量を４重量％にして、２−メチル−２，４−ペンタンジオールと２−エチル−１，３−ヘキサンジオールを除いた以外は同様にして［イエローインク１３］とした。
同様にマゼンタインク６において、マゼンタ分散液３の配合量を４重量％にして、２−メチル−２，４−ペンタンジオールと２−エチル−１，３−ヘキサンジオールを除いた以外は同様にして［マゼンタインク１３］とした。
同様にシアンインク６において、シアン分散液３の配合量を４重量％にして、２−メチル−２，４−ペンタンジオールと２−エチル−１，３−ヘキサンジオールを除いた以外は同様にして［シアンインク１３］とした。
【０２１１】
【比較例１０】
（イエローインク１４、マゼンタインク１４、シアンインク１４の調製）
実施例７のイエローインク７において、イエロー分散液４の配合量を１．０重量％にして、２−メチル−２，４−ペンタンジオールと２−エチル−１，３−ヘキサンジオールを除いた以外は同様にして［イエローインク１４］とした。
同様にマゼンタインク７において、マゼンタ分散液４の配合量を１．０重量％にして、２−メチル−２，４−ペンタンジオールと２−エチル−１，３−ヘキサンジオールを除いた以外は同様にして［マゼンタインク１４］とした。
同様にシアンインク７において、シアン分散液４の配合量を５重量％にして、２−メチル−２，４−ペンタンジオールと２−エチル−１，３−ヘキサンジオールを除いた以外は同様にして［シアンインク１４］とした。
【０２１２】
【評価試験】
つぎに上記［実施例１〜１０］及び［比較例１〜１０］のインクを用いて４色インクセットとして下記の試験を実施した。
【０２１３】
１）画像の鮮明性
サ−マルインクジェット方式の各色ノズル径１８μｍ、６００ｄｐｉピッチの３００ノズルを有するインクジェットプリンタ−及び積層ＰＺＴを液室流路の加圧に使用した各色ノズル径２８μｍ、２００ｄｐｉピッチの３００ノズルを有するインクジェットプリンタ−、静電アクチュエーターを液室流路の加圧に使用した各色３００ノズルを有するインクジェットプチンターにて印字を行い、２色重ね部境界の滲み、画像滲み、色調、濃度を目視により総合的に判断した。またＯＨＰ投影時の発色も評価した。
印字用紙は市販の再生紙、上質紙とボンド紙及び水溶性樹脂層の吸収層を持つ光沢フィルム、ＯＨＰシート
【０２１４】
＜官能評価におけるランク＞
評価のランク付けは次の基準で行った。
５：紙種によらず２色重ね部境界のにじみがなく、画像濃度が高く鮮明性、色再現性が高いもの
４：上記で画像濃度がやや低いもの
３：色境界滲みは少ないが紙種により２次色のむら等がみとめられるもの
２：紙種により色境界滲みが発生するもの
１：上記で画像濃度も低く鮮明性に劣るもの
【０２１５】
２）画像の耐水性
画像サンプルを３０℃の水に１分間浸漬し処理前後の画像濃度の変化をＸ−Ｒｉｔｅ９３８にて測定し、下記の式にて耐水性（耐色率％）を求めた。
耐色率（％）＝［１−（処理後の画像濃度／処理前の画像濃度）］×１００いずれの紙でも１０％以下を５、２０％以下となったものを４、３０％未満を３、３０％以上を２、５０％以上を１とした。
【０２１６】
３）画像の耐光性
画像サンプルをキセノンウェザオメーターＣｉ３５Ｗ（アトラス社製）にてボロシリ／ボロシリのフィルターを使用してブラックパネル温度６３℃、相対湿度５０％０．３５Ｗ／ｍ２で暴露試験を行い、２８時間後の褪色状態をＸ−Ｒｉｔｅ９３８にて色差にて判定した。ΔＥが各色６未満であるものは○、各色〜１５未満であるものは△、これ以上のものは×とした。
【０２１７】
４）画像の乾燥性
印字後の画像に一定条件で濾紙を押しつけインクが濾紙に転写しなくなるまでの時間を測定した。
いずれの紙でも１０秒以内で乾燥した場合に○と判定した。それ以上を×とした。
【０２１８】
５）保存安定性
各インクをポリエチレン容器に入れ、−２０℃、５℃、２０℃、７０℃でそれぞれの条件下で３カ月保存し、保存後の表面張力、粘度、及び沈澱物析出、粒子径の変化の有無を調べた。どの条件で保存しても、物性等の変化がないものを○とした。
【０２１９】
６）印字休止時信頼性
ノズル径３０μｍ１２８ノズルを有するＰＺＴで駆動するヘッドを有するプリンタ−を使用し動作中にキャップ、クリ−ニング等が行われないでどれだけ印字 休止しても復帰できるかを調べ、どれだけの時間で噴射方向がずれるか、あるいは吐出液滴の重量が変化するかでその信頼性を評価した結果を表に示す。
５：特に問題なし
４：滴重量の変化が小で噴射方向曲がり限度内
３：噴曲がり小
２：滴重量変化大であるが目詰まり発生はないもの
１：顕著な目詰まり発生
【０２２０】
【表１】

【０２２１】
【発明の効果】
本発明１によればインク中に特定の化合物を規定の重量比で含有するインクにおいて画像品質の高いインク処方を提供することができる。
本発明２〜５によればインク中に存在する遊離した一価アニオン濃度を規定することで色材の保存安定性を向上し連続及び休止後の吐出安定性を確保し、かつプリンターシステム内での接液する部材の耐久性を向上することができる。
【０２２２】
本発明６〜８によればインク中の特定化合物の含有量を規定することにより画像品質の高いインク処方を提供することができる。
本発明９〜１１によればインク中に色材として表面処理を施された顔料を含有するインク及びアニオン性染料を含有するインクにおいて特に大気安定したインク物性を有するインクをヘッドに供給できるインク処方を提供することができる。
【０２２３】
本発明１２によれば消泡剤の添加によりインク中の泡を低減し大気安定したインク物性を有するインクをヘッドに供給できるインク処方を提供することができる。
本発明１３によれば特に好ましいインク添加物の態様を示すことで顔料の環境変化による凝集が発生しにくい顔料インクを提供することができる。
【０２２４】
本発明１４によれば顔料粒子径分布の好ましい範囲を示すことで耐目詰まり性に優れ、かつヘッド内部のフィルター寿命を長期にわたって維持可能な顔料インクを提供することにある。
本発明１５によれば自己分散顔料を使用することで分散安定性に優れ、吐出特性の優れた顔料分散体を用いた顔料インクを提供することができる。
【０２２５】
本発明１６によれば自己分散顔料の粒径分布の好ましい範囲を示すことで耐目詰まり性に優れ、かつヘッド内部のフルター等の寿命を長期にわたって維持可能な顔料インクを提供することができる。
本発明１７によれば特に好ましい表面処理顔料の態様を示すことで耐水性が良好で文字滲み、カラー境界の滲みが少ない高信頼性の顔料インクを提供することができる。
【０２２６】
本発明１８によれば水溶性染料を使用することで発色性に優れ、耐水性のバランスされたインクを提供することができる。
本発明１９によれば着色樹脂微粒子を用いることで発色性に優れ、光沢紙等にも定着性が高い保存性に優れたインクを提供することができる。
本発明２０によれば着色微粒子の粒子径の範囲を限定することで耐目詰まり性に優れ、かつヘッド内部のフィルター等の寿命を長期にわたって維持可能とすることができる。
【０２２７】
本発明２１によれば特定のアニオン界面活性剤を添加することで画像特性に優れ高速印字に対応でいるインクを提供することができる。
本発明２２によれば残量検知や荷電制御方式のインクジェット等に好ましく使用できる物性範囲に調整され保存特性の優れたインクを提供することができる。本発明２３によればインクの粘度調整や保湿性を確保するのに好適に用いられ色材の凝集等が発生しない水溶性有機溶剤の添加されたインクを提供することができる。
【０２２８】
本発明２４によれば紙への濡れ性を改善し、浸透性を付与するのに好適なアニオン界面活性剤以外の界面活性剤の種類を特定し普通紙適正の改善されたインクを提供することができる。
本発明２５によれば紙への濡れ性を改善し、浸透性を付与する親水性溶剤を添加しあた普通紙適正の改善されたインクを提供することができる。
本発明２６によればプリンターに使用される部材とのマッチング特性に適切なインクｐＨ範囲を特性することで耐久性の高いプリンターとすることができる。
【０２２９】
本発明２７によれば該インクを用いることで普通紙に良好なカラー画像が形成できる。
本発明２８によれば該インクカートリッジを用いることで普通紙に良好なカラー画像が形成できる。
本発明の第２９によれば該インクを用いたインクジェット用機器を提供することで高速で普通紙に良好な画像を安定して印字することができる。
【図面の簡単な説明】
【図１】熱エネルギーを利用したインクジェット記録装置の主要部であるヘッド構成の一例を示す図である。
【図２】ヘッドを組み込んだインクジェット記録装置の一例を示す図である。
【図３】記録ヘッドにインク供給部材、例えば、チューブを介して供給されるインクを収容したインクカートリッジの一例を示す図である。
【図４】記録ヘッドとインクカートリッジとが一体となった例を示す図である。
【図５】記録装置の主要部である記録ヘッドの構成の一例を示す図である。
【図６】本発明を適用したインクジェットヘッドの断面図である。
【符号の説明】
１ インクジェッドヘッド
２ シリコン基板
３ ノズルプレート
４ ホウ珪酸ガラス基板
５ インク室
６ 共通インク室
７ インク供給路
８ 底壁
９ 凹部
９１ 対向壁
９２ 凹部表面
１０ セグメント電極
１１ インクノズル
１５ 絶縁層
Ｇ 電極間距離
１３ ヘッド
１４ ノズル
１５ 発熱素子基板
１６ 保護層
１７−１ 電極
１７−２ 電極
１８ 発熱抵抗体層
１９ 蓄熱層
２０ 基板
２１ インク
２２ 吐出オリフィス
２３ メニスカス
２４ インク小滴
２５ 被記録材
６１ ブレード
６２ キャップ
６３ インク吸収体
６４ 吐出回復部
６５ 記録ヘッド
６６ キャリッジ
６７ ガイド軸
６８ モーター
６９ ベルト
５１ 紙給部、
５２ 紙送りローラー
５３ 排紙ローラー
４０ インク収容部
４２ 栓
４４ インク吸収体
７０ 記録ユニット
７２ 大気連通口
８０ インク流路
８１ オリフィスプレート
８２ 振動板
８３ 圧電素子
８４ 基板
８５ 吐出口[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a recording liquid suitable for inkjet recording, and particularly to a recording liquid useful for forming an image on so-called plain paper.
[0002]
The present invention also relates to an aqueous ink composition (recording liquid) for an aqueous writing instrument, a recorder, and a pen plotter.
[Prior art]
1) Regarding reliability and storage stability of ink ejection characteristics, etc.
[0003]
2. Description of the Related Art In recent years, various studies have been made on ink jet printers for the purpose of improving printability on plain paper, in particular, water fastness and light fastness. In dye inks, addition of ultraviolet absorbers and antioxidants, examination of dye precipitants between colors by adding various water-soluble inorganic salts and polyvalent metal salts to reduce bleeding of color boundaries, and pH difference Investigations have been made to improve the image quality and the robustness. The problem here is that the reliability of the ejection characteristics and the like is reduced by the additive.
Ink jet printers and plotters using an ink using a pigment as a coloring material have been put on the market, but have a problem of reliability such as occurrence of clogging as compared with dye ink.
[0004]
In particular, when an attempt is made to add a highly permeable solvent for the purpose of controlling the wettability or the like, the aggregation of the pigment may occur due to a change in the characteristics of the dispersant. Therefore, Patent Documents 1 and 2 disclose surface treatment with a compound having a diazonium group of carbon black to introduce carboxylic acid and sulfonic acid as functional groups, thereby improving redispersibility and dispersion stability and improving reliability. Inks have been proposed. Further, Patent Literature 3 and Patent Literature 4 disclose inks containing trimethylolpropane, a urea derivative, or the like in order to improve the ejection stability of the first drop in an intermittent test using this ink.
[0005]
Further, with respect to organic pigments for color, Patent Literature 5 discloses a pigment in which a carboxylic acid or sulfonic acid group is introduced by surface treatment in the same manner as Patent Literature 1 or the like. Patent Document 6 discloses an organic pigment oxidized with sulfamic acid, and Patent Document 7 discloses an organic pigment in which a sulfonic acid group is introduced by a Friedel-Crafts reaction using a sulfonating agent.
These pigments can achieve dispersion stability without using a dispersant, but they do not use a polymer dispersant or the like, so they have improved abrasion resistance by adding a surfactant to improve fixability to recording paper. An ink is disclosed in US Pat.
[0006]
In this ink, the pH is increased to 7.5 to 8.0 by adding N, N-bis (hydroxyethyl) -2-aminoethanesulfonic acid and NaOH, which are good buffers, for the purpose of improving nozzle clogging and corrosion resistance. Adjusted to 9.
Patent Literature 9 discloses an ink in which a counter ion of a pigment having a water-soluble group introduced therein is replaced with quaternary ammonium from sodium and impurities are purified by an ultrafiltration method.
[0007]
Although inks with improved reliability have been studied by these methods, changes in ejection characteristics and storage stability due to a decrease in pH during high-temperature storage peculiar to a surface-treated pigment have not been sufficiently studied. For the ink ejected via thermal energy, the durability of the thermal element during long-term operation and the liquid contact with a head having a liquid chamber / supply unit made of silicon or glass members and / or metal members such as nickel and SUS. However, the ink itself deteriorates due to a significant drop in pH due to a change in temperature, causing corrosion and erosion, which adversely affects the ejection characteristics and the like.
[0008]
On the other hand, in dye-based inks, addition of a phosphate or the like to prevent corrosion and kogation of a heating element is disclosed in Patent Documents 10, 11 and 12; Japanese Patent Application Laid-Open Publication No. H11-163,086 discloses a method for preventing the above problem by including 1% by weight and 0.1 to 1% by weight of a hydroxide. However, when these are simply applied to a pigment system, there is a problem that aggregation of the pigment occurs.
[0009]
In order to solve the problem of pH stability in combination with a specific dye, sodium borate, N-tris (hydroxy) methyl-2-aminoethanesulfonic acid, N, N-bis (hydroxyethyl) are used as pH buffers. An ink to which glycine, triethanolamine and tris (hydroxymethyl) aminoethane are added is disclosed in Patent Document 14. Further, at least one compound selected from 2- (cyclohexylamino) ethanesulfonic acid, 3-N-cyclohexylamino-2-hydroxypropanesulfonic acid, 3-N-cyclohexylaminopropanesulfonic acid and glycine, and an alkali metal hydroxide Patent Document 15 discloses an ink containing a carbonate and adjusting the pH to 9.5 to 9.8 and causing a small decrease in pH even after being left at 60 ° C. for one week.
[0010]
However, these patents are concerned with the pH stability of a particular dye and the dye itself has some buffering action. Patent Document 16 discloses an ink containing a dye and a 2-amino-1,3-propanediol derivative as an organic weakly basic substance and adjusted to pH 8 to 10. These dyes also have a buffering property, making it possible to maintain the pH at 9 to 9.3 even after storage at 60 ° C.
On the other hand, pigments that have been subjected to surface treatment may aggregate when the ionic strength is high, so that the stability is ensured by removing low molecular compounds having dissociative groups as much as possible by ultrafiltration or the like. .
[0011]
Further, with respect to a pigment ink using a dispersant, Patent Literature 17 discloses an ink in which the ink pH is higher than 6 and lower than 8 by using a buffer solution using carbon black having a pH of 6 or less. Dispersant-dispersed carbon black has a problem in that redispersibility is lower than that of self-dispersed pigments.
[0012]
When a pigment is used in an inkjet ink, it is generally desirable that the pigment be stably dispersed in water and can be retained for a long period of time. Generally, one of the factors that hinders stable dispersion of a pigment is the incorporation of a polyvalent ionic substance having a polarity opposite to that of the coloring material used into the ink. For example, Patent Documents 18 and 19 describe reducing iron ions and barium ions to less than several ppm.
[0013]
However, no study has been made on ions having the same polarity as the coloring material used.
The coloring material containing a pigment may generate impurities during the synthesis process and may be mixed therein, or may mix during the pigment dispersion process. However, since such a coloring material is a dispersion system, it is generally difficult to accurately separate impurities in a subsequent process. If the impurities are ions of the opposite polarity to the color material, it is possible to separate them by an ion exchange method or the like. However, if the impurities are ions of the same polarity, the ions which are such impurities are separated. It is often difficult. For this reason, ions of the same polarity as the color material are easily mixed into the ink finally obtained.
When the penetrant and the humectant are specific water-soluble organic solvents, if the monovalent anion of the same polarity as the coloring material is present in the ink in a certain amount or more, the ink thickens as the ink is stored for a long time, Its storage stability was sometimes reduced.
[0014]
2) Regarding image quality of ink
Ink jet recording is conventionally known as an excellent recording method that does not select a recording material, and research and development of a recording apparatus, a recording method, a recording material, and the like have been actively performed.
However, in fact, in the ink jet recording apparatus which has been conventionally developed and commercialized, a special recording material specially developed for the ink jet such as an ink jet paper or an ink jet transparency film is not used. {Circle around (1)} good fixing property, [2] so-called "sharp", recorded image with no blur or bleeding (hereinafter referred to as feathering) in the periphery of characters and image, [3] optical density (Optical Density: It is difficult to obtain recorded images with high OD) and is generally used in office paper such as plain paper copier paper (PPC paper), letter paper, bond paper, postcards, letter paper, envelopes, report paper, etc., and at home. Paper, as well as transparent films (OHP films) ) And the like, it was not possible to satisfy the above characteristics at the same time when recording was performed by a conventionally known ink jet recording apparatus.
[0015]
Although the above properties can be satisfied by using ink jet paper, ink jet paper is generally expensive and ink jet paper is generally a single-side coated paper, so it is natural that ink jet paper is coated. When recording is performed on a non-existing surface, there is a disadvantage that fixability and print quality are remarkably deteriorated, and this is one of the causes of the general lack of use of ink jet recording apparatuses.
[0016]
Therefore, (1) excellent fixability, (2) a recorded image of excellent print quality without blurring or bleeding (hereinafter collectively referred to as feathering) in peripheral portions of characters and images, which is so-called "cut", and (3) Various developments have been made to obtain a recorded image having a high optical density (Optical Density: OD).
[0017]
For example, (1) a method using a strong alkaline ink having a pH of about 13 (Patent Documents 20, 21, and 22), and (2) a method of recording by heating a solid wax-like ink at room temperature and discharging the ink in a molten state. (Patent Documents 23 and 24), (3) A method of performing recording using an oil-based ink using a water-insoluble organic solvent as a liquid medium, and the like have been developed and commercialized. In addition, regarding only the purpose of (1) for obtaining good fixability, (4) a method using an ink containing a large amount of a surfactant (Patent Document 25), (5) glycerin and N-methyl-2-pyrrolidone (6) Making the pH of the ink strongly alkaline, and further adding a fluorine-based surfactant to the ink using a combination of a direct dye and a surfactant having a low surface tension of an amount of cmc or less and a low surface tension. (Patent Documents 27 and 28) are known.
[0018]
However, in the method (1), there is a danger in handling because the ink is strongly alkaline, and printing can be performed with good fixability and good print quality on acidic paper using rosin as a sizing agent. Neutral paper using alkyl ketene dimer, stearic anhydride, and the like, whose production has increased in Japan, also shows a significant decrease in fixability and a slight decrease in print quality.
In addition, this strong alkaline ink has a drawback that it is easily penetrated due to a large penetrating force into the inside of paper, and it is extremely difficult to perform double-sided recording.
[0019]
The method (2) is an excellent method that satisfies the above-mentioned characteristics (1)-(3). However, the printed portion swells, and the printed image may be transferred when a number of printed materials are left standing. However, there is a known drawback that the papers are stuck together, and furthermore, there is a problem that a device for heating the ink is required and the apparatus becomes complicated.
[0020]
The method (3) is particularly excellent in fixability, but requires consideration of the odor and safety of the organic solvent contained in the ink. Therefore, the production lot number is printed on the bottom of the can or on the outside of the box. It is used only for industrial purposes such as printing on orifices, and is not in a situation where it is used in ordinary homes.
[0021]
The method (4) using the ink has a problem in printing quality as disclosed in Patent Documents 29 and 30, and cannot be said to be an excellent method.
[0022]
The method of using the ink of (5) is, as clarified in the embodiment, the drying speed of the ink after printing (the "fixing property" in the present invention is about 8 to 15 seconds, and is conventionally known. It can be said that the fixing property is superior to that of the ink that has been used, but from the standpoint of using the recording device, the time of 8-15 seconds is felt long, and depending on the paper, it may come out of the recording device. If the printed matter is immediately picked up by hand, the hand may be stained with ink, and feathering may become remarkable depending on the type of paper. Therefore, further improvement is desired.
[0023]
For the ink of (6), the fixing time can be set to 5 seconds or less. The present inventors have confirmed that the ink is excellent in fixability. However, as described in the description of the method (1), the ink has excellent safety and fixability on neutral paper. -There is a problem in print quality and strike-through, which is not preferable.
[0024]
In addition, in general, it is desirable to use water-based ink in consideration of odor, safety, ink handling properties, and the like, in consideration of office use and general home use. If the recording material has stains such as fingerprints on the recording surface, feathering tends to occur only in that part, and depending on the paper, the printing quality may be significantly changed on the front and back of the paper. When setting in an ink jet recording apparatus, there is also a problem that careful attention must be paid to the handling of the recording material.
[0025]
Further, as is well known in the art, it contains 1-5% by weight of a water-soluble dye and 20-50% by weight of a water-soluble organic solvent such as glycols, and has a surface tension of about 40-55 dyne / cm. In a multi-nozzle ink jet recording apparatus using water-based ink, nozzles that do not perform printing (not used for printing) may be clogged even during printing due to evaporation of water from the nozzles. For example, if "-" is repeatedly printed for about 120 seconds and then "1" is printed, the nozzle used when printing "-" normally discharges, but the other nozzles do not discharge. In some cases, such a problem may occur that "1" cannot be correctly printed.
[0026]
Also, if the recording apparatus is left for a while after printing (for example, about two days and nights assuming weekends and holidays), a non-ejection phenomenon that is considered to be caused by an increase in ink viscosity due to evaporation of water from nozzles is often observed. Since it is necessary to perform an operation for solving the non-ejection phenomenon every time the recording apparatus is used, it is often said that the ink jet recording apparatus is difficult to use. Such troubles are relatively common when using a recording device that uses a relatively small amount of energy to fly ink, and the bubble jet (registered trademark) recording device has a greater effect than the ink jet recording device using a piezo element. However, because of the small ejection energy, it is often seen especially in bubble jet recording apparatuses, and various improvement measures have been devised.
[0027]
In order to prevent the above troubles, it is necessary to incorporate various recovery devices such as a cap and a pump into the printing apparatus, which is one of the causes of making the ink jet printing apparatus complicated and expensive.
[0028]
[Patent Document 1]
U.S. Pat. No. 5,571,311
[Patent Document 2]
Japanese Unexamined Patent Publication No. Hei 10-510862
[Patent Document 3]
U.S. Pat. No. 5,976,233
[Patent Document 4]
JP-A-10-3300665
[Patent Document 5]
U.S. Pat. No. 5,922,118
[Patent Document 6]
JP-A-10-273606
[Patent Document 7]
JP-A-11-246807
[Patent Document 8]
JP-A-11-181340
[Patent Document 9]
JP-A-11-222573
[Patent Document 10]
U.S. Pat. No. 5,032,892
[Patent Document 11]
U.S. Pat. No. 5,389,131
[Patent Document 12]
JP-A-7-268665
[Patent Document 13]
JP-A-7-102389
[Patent Document 14]
JP-A-4-226175
[Patent Document 15]
JP-A-8-41398
[Patent Document 16]
JP-A-9-268267
[Patent Document 17]
JP-A-4-149286
[Patent Document 18]
JP-A-8-31379
[Patent Document 19]
JP-A-8-31380
[Patent Document 20]
JP-A-56-57862
[Patent Document 21]
JP-A-57-102970
[Patent Document 22]
JP-A-57-102971
[Patent Document 23]
JP-A-61-159470
[Patent Document 24]
JP-A-62-48774
[Patent Document 25]
JP-A-55-29546
[Patent Document 26]
JP-A-56-49771
[Patent Document 27]
JP-A-56-57862
[Patent Document 28]
JP-A-57-102971
[Patent Document 29]
JP-A-55-80477
[Patent Document 30]
JP-A-56-49771
[0029]
[Problems to be solved by the invention]
A first object of the present invention is to provide an ink formulation having high image quality.
The second, third, fourth, and fifth objects of the present invention are to improve the storage stability of the coloring material, secure the discharge stability after continuous and pause, and improve the durability of the members that come into contact with the liquid in the printer system. Is to do.
A sixth, seventh, and eighth object of the present invention is to provide an ink formulation with high image quality.
[0030]
The ninth, tenth, and eleventh objects of the present invention are inks that can supply inks having ink properties that are particularly stable in the atmosphere among inks containing a pigment that has been subjected to a surface treatment as a coloring material and inks that contain an anionic dye. An object of the present invention is to provide a prescription and improve the durability of a member that comes into contact with a liquid in a printer system.
A twelfth object of the present invention is to provide an ink formulation capable of reducing the bubbles in the ink and supplying an ink having ink physical properties stable to the atmosphere to the head.
[0031]
A thirteenth object of the present invention is to provide a pigment ink in which aggregation of the pigment due to environmental changes is less likely to occur by showing a particularly preferred embodiment of the ink additive.
A fourteenth object of the present invention is to provide a pigment ink having excellent clogging resistance and capable of maintaining the filter life inside the head for a long period of time.
A fifteenth object of the present invention is to provide a pigment ink using a pigment dispersion having excellent dispersion stability and excellent ejection characteristics.
[0032]
A sixteenth object of the present invention is to provide a pigment ink having excellent clogging resistance and capable of maintaining the life of a filter or the like inside a head for a long period of time.
A seventeenth object of the present invention is to provide a highly reliable pigment ink which shows particularly preferable aspects of the surface-treated pigment, has good water resistance, blurs characters, and has little blur at color boundaries.
An eighteenth object of the present invention is to provide a dye ink which is excellent in color development and balanced in water resistance.
A nineteenth object of the present invention is to provide an ink which is excellent in storability and made of a coloring material comprising colored fine particles having excellent coloring properties and high fixability to glossy paper and the like.
[0033]
A twentieth object of the present invention is to provide an ink containing colored fine particles which is excellent in clogging resistance and can maintain the life of a filter or the like in a head for a long period of time.
A twenty-first object of the present invention is to provide an ink to which a specific anionic surfactant is added, which is particularly preferable and can improve the wettability to plain paper.
A twenty-second object of the present invention is to provide an ink having excellent storage characteristics adjusted to a physical property range which can be preferably used for a remaining amount detection or a charge control type ink jet.
A twenty-third object of the present invention is to provide an ink to which a water-soluble organic solvent which is preferably used for adjusting the viscosity of the ink and ensuring moisture retention and which does not cause aggregation of a coloring material or the like is added.
[0034]
A twenty-fourth object of the present invention is to provide an ink having an improved suitability for plain paper by specifying the types of surfactants other than anionic surfactants suitable for improving wettability to paper and imparting permeability. Is to do.
A twenty-fifth object of the present invention is to provide an ink with improved suitability for plain paper, to which a hydrophilic solvent for improving wettability on paper and imparting permeability is added.
A twenty-sixth object of the present invention is to provide a printer having high durability by specifying an ink pH range appropriate for matching characteristics with members used in the printer.
[0035]
A twenty-seventh object of the present invention is to provide a recording method capable of forming a good image using the ink.
A twenty-eighth object of the present invention is to provide an ink cartridge capable of forming a good image using the ink.
A twenty-ninth object of the present invention is to provide an ink jet device which can form a good image using the ink.
[0036]
[Means for Solving the Problems]
The present inventors have conducted intensive studies to solve the above problems, and as a result, Mj (capacity of one ink droplet) is 2 to 37 pl, Vj (ink droplet speed) is 6 to 20 m / sec, and the frequency is 1 KHz. As described above, in one-pass printing with a resolution of 300 dpi or more, 2-methyl-2,4-pentanediol is 15 to 40% by weight in an ink having a pigment concentration of 10% by weight or more and an ink viscosity of 8 mPa · s (25 ° C.) or more. -Ethyl-1,3-hexanediol is blended in an amount of 2 to 10 wt%, and the respective proportions are blended in a weight ratio of 20/1 to 15/10, so that the image density and strikethrough can be reduced as compared with the conventional ink formulation. The present invention has been completed based on the finding that image characteristics such as density, feathering, and color bleeding are greatly improved.
[0037]
That is, the present invention is as follows.
(1) It contains at least a coloring material, an organic solvent for dissolving or dispersing the same, water, an anion or a nonionic surfactant, a coloring material concentration of 10 wt% or more, and an ink viscosity of 8 mPa · s (25 ° C.) In the above recording liquid, 2-methyl-2,4-pentanediol and 2-ethyl-1,3-hexanediol are contained in a weight ratio of 20/1 to 15/10. .
(2) The recording liquid according to (1) above, wherein the concentration of free monovalent anions present in the recording liquid is 500 ppm or less.
(3) The recording liquid according to (1) above, wherein the concentration of free monovalent anions present in the recording liquid is 300 ppm or less.
(4) The recording liquid according to (1) above, wherein the concentration of free monovalent anions present in the recording liquid is 100 ppm or less.
(5) The method according to any one of (1) to (4), wherein the free monovalent anion present in the recording liquid is at least one of a halogen ion, a nitrate ion, and an organic acid ion. Recording liquid.
(6) The recording liquid according to the above (1), which contains 15 to 40% by weight of 2-methyl-2,4-pentanediol.
(7) The recording liquid according to the above (1), comprising 2 to 10% by weight of 2-ethyl-1,3-hexanediol.
(8) The recording liquid according to any one of (1) to (7) above, which contains at least one of 2-pyrrolidone, N-methyl-2-pyrrolidone, and N-hydroxyethyl-2-pyrrolidone. .
(9) The recording liquid according to any one of the above (1) to (8), which contains 2-amino-2-ethyl-1,3-propanediol.
(10) The recording liquid according to any one of the above (1) to (9), which comprises N-cyclohexyl-2-aminoethanesulfonic acid.
(11) The recording liquid according to any one of the above (1) to (10), which contains benzotriazole.
(12) The recording liquid according to any one of the above (1) to (11), which contains a silicone-based antifoaming agent.
(13) The method according to any one of the above (1) to (12), wherein the coloring material is a pigment, is dispersed in water by a dispersant, and a carboxyl group is bonded to the dispersant. Recording liquid.
(14) The recording liquid according to (13), wherein the pigment has a particle size of 10 nm to 300 nm.
(15) The recording liquid according to any one of (1) to (12) above, wherein the coloring material is a self-dispersing pigment having an anionic group on the surface.
(16) The recording liquid as described in (15) above, wherein the self-dispersion pigment has a particle size of 10 nm to 300 nm.
(17) The recording liquid according to the above (15) or (16), wherein at least one of the anionic groups is a carboxylic acid group.
(18) The recording liquid according to any one of the above (1) to (12), wherein the coloring material is a dye having at least one carboxylic acid group and / or sulfonic acid group.
(19) The recording liquid according to any one of the above (1) to (12), wherein the coloring material is fine particles colored with a dye or a pigment.
(20) The recording liquid according to the above (19), wherein the colored fine particles have a particle diameter of 10 nm to 300 nm.
(21) The recording liquid according to any one of the above (1) to (20), wherein the surfactant having an anionic group is a polyoxyethylene alkyl ether acetate and / or a dialkyl sulfosuccinate. .
(22) The recording liquid according to any one of the above (1) to (21), wherein the conductivity is 1 mS / cm or more.
(23) The organic solvent is glycerin, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 1,5-pentanediol, tetraethylene glycol, 1,6-hexanediol, polyethylene glycol, 1,2,4-butanetriol, 1,2,6-hexanetriol, thiodiglycol, 1,3-dimethyl-2 -The recording liquid according to any one of the above (1) to (22), which is one or more water-soluble organic solvents selected from imidazolidinones.
(24) It further contains at least one surfactant selected from acetylene glycol-based surfactant, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyethylene-polypropylene copolymer, and fluorine-based surfactant. The recording liquid according to any one of the above (1) to (23).
(25) The recording liquid according to any one of (1) to (24), further comprising a diol having 6 or more carbon atoms and an alkyl ether.
(26) The aqueous ink according to any one of the above (1) to (25), wherein the pH is adjusted to 6 or more and 11 or less.
(27) The recording liquid according to any one of the above (1) to (26) is caused to fly as fine droplets by thermal energy or mechanical energy, and the droplet is measured according to the JIS P-8122 test method. A recording method, wherein an image is formed by adhering to a recording material for 3 seconds or more.
(28) A recording liquid cartridge provided with a recording liquid storage section containing a recording liquid, wherein the recording liquid is the recording liquid according to any one of (1) to (26).
(29) An ink jet recording apparatus including a recording liquid storage section or a recording liquid cartridge containing a recording liquid, a head unit or a recording unit for dropping and discharging the recording liquid by the action of thermal energy, wherein the recording liquid is An ink jet recording apparatus comprising the recording liquid according to any one of (1) to (26).
Hereinafter, the inventions (1) to (29) are referred to as present inventions 1 to 29.
[0038]
BEST MODE FOR CARRYING OUT THE INVENTION
Mj (capacity of one ink drop) is 2 to 37 pl, Vj (ink drop speed) is 6 to 20 m / sec, frequency is 1 KHz or more, resolution is 300 dpi or more, pigment density is 10 wt% or more in one-pass printing, ink viscosity is 1 Blends 15% to 40% by weight of 2-methyl-2,4-pentanediol and 2% to 10% by weight of 2-ethyl-1,3-hexanediol in an ink of 8 mPa · s (25 ° C.) or higher. Is blended at a weight ratio of 20/1 to 15/10, image characteristics such as image density, strike-through density, feathering, and color bleed are greatly improved as compared with the conventional ink formulation.
[0039]
In the present invention, the concentration of free monovalent anions present in the ink is preferably 500 ppm or less, more preferably 300 ppm or less. Further, it is most preferably at most 100 ppm. When the concentration of the released monovalent anion in the ink is equal to or less than the above value, aggregation of the dispersed colorant (for example, pigment) can be suppressed when the ink is stored for a long time, and fluctuation of ink physical properties can be suppressed. Further, reliability such as ink ejection characteristics can be improved.
[0040]
Here, the free monovalent anion present in the ink is mainly a monovalent anion contained in the production process of the colorant dispersion, and is included in the ink from the colorant dispersion. It has become. Examples of such free monovalent anions include halogen ions such as chlorine, bromine, and element ions, and organic acid ions such as nitrate ion, hydrogen carbonate ion, hydroxyl ion, and acetate ion. Is typically mixed with a halogen ion, a nitrate ion, or an organic acid ion, and more typically a halogen ion such as chlorine or bromine. is there.
[0041]
In the present invention, as means for adjusting the monovalent anion concentration of the ink within the above range, for example, means for suppressing the incorporation of monovalent anions in the production stage of materials such as pigments and dispersants used in inks However, for example, it is also possible to adjust the monovalent anion concentration by means such as ultrafiltration of the pigment dispersion.
[0042]
In the present invention, the concentration of free monovalent anions present in the ink is determined, for example, by separating the ink into a pigment solid and a liquid component by a centrifugation method or an ultrafiltration method, and ion chromatography or liquid component. It can be determined by measuring with an ion electrode.
[0043]
The ink of the present invention is charged not only by ink using a pressure generated by PZT, by ink discharged by a vibrating plate bent by electrostatic force, but also by drop-on-demand ink jet printer of bubble jet (registered trademark) type utilizing film boiling. In addition, it can be favorably used for any printer of a so-called charge control system that vibrates with PZT. In particular, even a nozzle having a small nozzle diameter of 20 μm or less can be stably ejected from the viewpoint of high reliability.
[0044]
The addition amount of the coloring material in the ink of the present invention depends on the purpose of use, but is used in the range of 10 to 20% by weight, preferably 10 to 15% by weight. When the content is less than 10% by weight, the image density is low when used for high-speed printing at 300 dpi, and when it is more than 20%, it is difficult to eject the ink with a high viscosity.
[0045]
The water-soluble dye used in the present invention can be used by mixing with other coloring materials as necessary. As the water-soluble dye to be used, a dye classified into an acid dye, a direct dye, a basic dye, a reactive dye and an edible dye in color index and having excellent water resistance and light resistance is used. Specific examples of these dyes are as follows.
[0046]
(As acid dye and food dye)
C. I. Acid. Yellow 17,23,42,44,79,142
C. I. Acid. Red 1, 8, 13, 14, 18, 26, 27, 35, 37, 42, 52, 82, 87, 89, 92, 97, 106, 111, 114, 115, 134, 186, 249, 254, 289
C. I. Acid. Bull 9, 29, 45, 92, 249
C. I. Acid. Black 1,2,7,24,26,94
C. I. Hood. Yellow 3, 4
C. I. Hood. Red 7,9,14
C. I. Hood. Black 1,2
[0047]
(As direct dye)
C. I. direct. Yellow 1, 12, 24, 26, 33, 44, 50, 86, 120, 132, 142, 144
C. I. direct. Red 1,4,9,13,17,20,28,31,39,80,81,83,89,225,227
C. I. direct. Orange 26,29,62,102
C. I. direct. Blue 1, 2, 6, 15, 22, 22, 25, 71, 76, 7986, 87, 90, 98, 163, 165, 199, 202
C. I. direct. Black 19,22,32,38,51,56,71,74,75,77,154,168,171
[0048]
(As basic dye)
C. I. Basic. Yellow 1, 2, 11, 13, 14, 15, 19, 21, 23, 24, 25, 28, 29, 32, 36, 40, 41, 45, 49, 51, 53, 63, 64, 65, 67, 70, 73, 77, 87, 91
C. I. Basic. Red 2,12,13,14,15,18,22,23,24,27,29,35,36,38,39,46,49,51,52,54,59,68,69,70,73 , 78, 82, 102, 104, 109, 112
C. I. Basic. Blue 1,3,5,7,9,21,22,26,35,41,45,47,54,62,65,66,67,69,75,77,78,89,92,93, 105, 117, 120, 122, 124, 129, 137, 141, 147, 155
C. I. Basic. Black 2,8
[0049]
(As reactive dye)
C. I. Reactive. Black 3,4,7,11,12,17
C. I. Reactive. Yellow 1, 5, 11, 13, 14, 20, 21, 22, 25, 40, 47, 51, 55, 65, 67
C. I. Reactive. Red 1,14,17,25,26,32,37,44,46,55,60,66,74,79,96,97,180
C. I. Reactive. Blue 1, 2, 7, 14, 15, 23, 32, 35, 38, 41, 63, 80, 95
Etc. can be used. Particularly, acid dyes and direct dyes can be preferably used. Also, Projet (TM) series dyes such as Projet Cyan 2, Projet Magenta 2, and Projet Yellow-2 manufactured by Avicia and developed as ink jet dyes are preferable.
[0050]
Particularly preferred dyes are those in which sulfonic acid and carboxylic acid are introduced from the balance between water resistance and reliability.
[0051]
Although it is not limited to the following, specific examples of the free acid form are as follows.
[0052]
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[0053]
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[0054]
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[0055]
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[0056]
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[0057]
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[0058]
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[0059]
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[0060]
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[0061]
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[0062]
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[0063]
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[0064]
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[0065]
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[0066]
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[0067]
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[0068]
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[0069]
As the pigment used in the present invention, organic pigments such as azo, phthalocyanine, anthraquinone, dioxazine, indigo, thioindigo, perylene, isoindolenone, aniline black, azomethine, and rhodamine B Pigments and carbon black; and inorganic pigments include iron oxide, titanium oxide, barium calcium carbonate, aluminum hydroxide, barium yellow, navy blue, cadmium red, chrome yellow, and metal powder.
[0070]
More specifically, carbon blacks (CI pigment black 7) such as furnace black, lamp black, acetylene black, and channel black, or copper oxides and iron oxides (CI. Pigment Black 11), metals such as titanium oxide, and organic pigments such as aniline black (CI Pigment Black 1).
[0071]
As pigments for color inks, C.I. I. Pigment Yellow 1 (Fast Yellow G), 3, 12 (Disazo Yellow AAA), 13, 14, 17, 23, 24, 34, 35, 37, 42 (yellow iron oxide), 53, 55, 74, 81, 83 (Disazo Yellow HR), 95, 97, 98, 100, 101, 104, 108, 109, 110, 117, 120, 128, 138, 150, 153
[0072]
C. for magenta I. Pigment Red 1, 2, 3, 5, 17, 22 (Brilliant Fast Scarlet), 23, 31, 38, 48: 2 (Permanent Red 2B (Ba)), 48: 2 (Permanent Red 2B (Ca)), 48 : 3 (permanent red 2B (Sr)), 48: 4 (permanent red 2B (Mn)), 49: 1, 52: 2, 53: 1, 57: 1 (brilliant carmine 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81 (rhodamine 6G lake), 83, 88, 92, 101 (Bengara), 104, 105, 106, 108 (cadmium red), 112, 114, 122 (dimethylquinacridone), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 185, 190, 193, 209, 2 19
[0073]
C. for cyan I. Pigment Blue 1, 2, 15 (copper phthalocyanine blue R), 15: 1, 15: 2, 15: 3 (phthalocyanine blue G), 15: 4, 15: 6 (phthalocyanine blue E), 16, 17: 1, 56, 60, 63; etc. can be used.
[0074]
The following pigments can be used alone or as a mixture for red, green and blue as intermediate colors.
C. I. Pigment Red 177, 194, 224, C.I. I. Pigment Orange 43, C.I. I. Pigment Violet 3, 19, 23, 37, C.I. I. Pigment Green 7,36
[0075]
Black is carbon black produced by a furnace method or a channel method. The primary particles have a particle size of 15 to 40 nm and a specific surface area of 50 to 300 m by a BET adsorption method. ² / G, a DBP oil absorption of 40 to 150 ml / 100 g, a volatile matter of 0.5 to 10%, and a pH of 2 to 9 are used. Particularly, acidic carbon black having a pH of 6 or less is preferable at a high concentration. Further, carbon black subjected to hypochlorite oxidation treatment, carbon black treated with a sulfonating agent, and carbon black treated with a diazonium compound to introduce an anionic dissociating group such as sulfonic acid and carboxylic acid are more preferable.
[0076]
As a yellow pigment, a C.I. I Pigment Yellow 74, 128 and 138 are preferred.
As the magenta pigment, quinacridone-based C.I. I. Pigment Red 122 and 209 are preferred. Cyan is a phthalocyanine compound. I. Pigment Blue 15: 3, aluminum-coordinated phthalocyanine, and metal-free phthalocyanine are preferred. These color organic pigments are also pigments in which sulfonic acid groups and carboxylic acid groups have been introduced by surface treatment, and are more excellent in dispersion stability, and those capable of obtaining dispersion stability without a dispersant can be suitably used as self-dispersion pigments. . In addition, pigments having encapsulated surfaces or pigments grafted with polymers can also be used as highly reliable inks having excellent dispersion stability.
[0077]
Next, preparation methods of the pigment dispersion liquid subjected to the surface treatment are shown as Reference Examples 1 to 5.
<Production Example 1> Carbon black dispersion liquid 1 treated with hypochlorous acid
After 300 g of commercially available acidic carbon black (pH 2.5, Monarch 1300, manufactured by Cabot Corporation) is well mixed with 1000 ml of water, 450 g of sodium hypochlorite (effective chlorine concentration: 12%) is dropped, and 100 to 105 ° C. For 8 hours. 100 g of sodium hypochlorite (effective chlorine concentration: 12%) was further added to this liquid, and the mixture was dispersed by a horizontal disperser for 3 hours. The obtained slurry was diluted 10 times with water, the pH was adjusted with lithium hydroxide, and the concentrate was desalted and concentrated to an electric conductivity of 0.2 mS / cm with an ultrafiltration membrane. And The coarse particles were removed by centrifugation, and the mixture was further filtered through a 1-micron nylon filter to obtain a carbon black dispersion liquid 1. The total content of Fe, Ca, and Si was 100 ppm or less as measured by ICP. The chlorine ion concentration was also set to 10 ppm or less. The average particle size (D50%) measured by Microtrac UPA was 95 nm.
[0078]
<Production Example 2> Carbon black dispersion liquid 2 treated with a sulfonating agent
150 g of a commercially available carbon black pigment (“Printex # 85” manufactured by Degussa) was thoroughly mixed in 400 ml of sulfolane, finely dispersed by a bead mill, 15 g of amidosulfuric acid was added, and the mixture was stirred at 140 to 150 ° C. for 10 hours. The obtained slurry is put into 1000 ml of ion-exchanged water, and a surface-treated carbon black wet cake is obtained by a centrifugal separator at 12000 rpm. This carbon black wet cake was redispersed in 2000 ml of ion-exchanged water, the pH was adjusted with lithium hydroxide, and desalted and concentrated by an ultrafiltration membrane to obtain a carbon black dispersion having a pigment concentration of 20% by weight. This was filtered through a 1-micron nylon filter to obtain a carbon black dispersion 2. The total content of Fe, Ca, and Si was 100 ppm or less as measured by ICP. The sulfate ion concentration was also 100 ppm or less. The average particle size was 80 nm.
[0079]
<Production Example 3> Carbon black dispersion liquid 3 treated with a diazo compound
230m surface area ² 100 g of carbon black having a DBP oil absorption of 70 ml / 100 g and 34 g of p-amino-N-benzoic acid were mixed and dispersed in 750 g of water, and 16 g of nitric acid was added dropwise thereto, followed by stirring at 70 ° C. Five minutes later, a solution of 11 g of sodium nitrite dissolved in 50 g of water was added, and the mixture was further stirred for 1 hour. The obtained slurry was diluted 10-fold and centrifuged to remove coarse particles, the pH was adjusted to 8-9 by diethanolamine, and the concentrate was desalted and concentrated using an ultrafiltration membrane, and a carbon black dispersion having a pigment concentration of 20% by weight was obtained. And This was used as a carbon black dispersion 3 using a polypropylene 0.5 μm filter. The total content of Fe, Ca, and Si was 100 ppm or less as measured by ICP. The nitrate ion concentration was 10 ppm or less. The average particle size was 99 nm.
[0080]
<Production Example 4> Carbon black dispersion liquid 4 treated with a diazo compound
A solution of about 75 ° C. containing 2 liters of water and 43 g of sulfanilic acid was stirred for 230 m ² / G and a surface area of 70 g / g and a DBPA of 70 ml / 100 g. The mixture was cooled to room temperature with stirring and 26.2 g of concentrated nitric acid was added. A solution of 20.5 g of sodium nitrite in water was added. An internal salt of 4-sulfobenzenediazonium hydroxide was prepared and reacted with carbon black. The dispersion was stirred until the bubbling that had ceased. The obtained slurry was diluted, the pH was adjusted with lithium hydroxide to pH 8-9, and coarse particles were removed by centrifugation. Subsequently, desalting and concentration were performed using an ultrafiltration membrane to disperse carbon black with a pigment concentration of 20%. Liquid. This was filtered through a polypropylene 1 μm filter to obtain a carbon black dispersion liquid 4. The total content of Fe, Ca, and Si was 100 ppm or less as measured by ICP. The nitrate ion concentration was 50 ppm or less. The average particle size was 95 nm.
[0081]
<Production Example 5> Color pigment dispersion liquid subjected to surface chemical treatment (yellow dispersion liquid 1, magenta dispersion liquid 1, cyan dispersion liquid 1)
C.I. I. Pigment Yellow 128 was subjected to low-temperature plasma treatment to prepare a pigment into which a carboxylic acid group was introduced. This was dispersed in ion-exchanged water and desalted and concentrated by an ultrafiltration membrane to obtain a yellow pigment dispersion 1 having a pigment concentration of 20%. The average particle diameter was 70 nm, and the total content of Fe, Ca, and Si was 100 ppm or less.
[0082]
Similarly, C.I. I. Pigment magenta 122 was used to prepare a magenta pigment dispersion 1 having a pigment concentration of 20%. The average particle content was 60 nm, and the total content of Fe, Ca, and Si was 100 ppm or less.
[0083]
Similarly, C.I. I. Pigment Cyan 15: 3 was used to prepare a cyan pigment dispersion 1 having a pigment concentration of 20%. The average particle diameter was 80 nm, and the total content of Fe, Ca, and Si was 100 ppm or less.
[0084]
In the present invention, a pigment dispersion using a pigment dispersant can also be used. As a pigment dispersant, as a hydrophilic polymer, in the natural system, plant polymers such as gum arabic, gum guar gum, guar gum, karaya gum, locust bean gum, arabinogalactone, pectin, quinceide starch, alginic acid, Seaweed polymers such as carrageenan and agar, animal polymers such as gelatin, casein, albumin and collagen, microbial polymers such as xanthene gum and dextran, and methylcellulose and ethylcellulose in semi-synthetic systems , Hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, etc., fibrous polymers, starch starch glycolate, sodium starch phosphate, etc., starch polymers, sodium alginate, alginic acid Seaweed polymer such as propylene glycol ester Pure synthetic systems include polyvinyl alcohol, polyvinyl pyrrolidone, vinyl polymers such as polyvinyl methyl ether, non-crosslinked polyacrylamide, polyacrylic acid and alkali metal salts thereof, acrylic resins such as water-soluble styrene acrylic resin, Water-soluble styrene maleic acid resin, water-soluble vinyl naphthalene acrylic resin, water-soluble vinyl naphthalene maleic resin, polyvinyl pyrrolidone, polyvinyl alcohol, alkali metal salt of β-naphthalene sulfonic acid formalin condensate, quaternary ammonium, amino group, etc. And a natural polymer compound such as shellac and the like having a cationic functional group salt in the side chain.
In particular, those into which a carboxylic acid group such as a homopolymer of acrylic acid, methacrylic acid, or styrene acrylic acid or a copolymer of a monomer having another hydrophilic group is introduced are preferable as the polymer dispersant.
[0085]
When a surfactant is used, an anionic surfactant such as polyoxyethylene alkyl ether phosphate and polyoxyethylene alkyl ether acetate, and a nonionic surfactant such as nonylphenyl ether can also be used.
[0086]
Next, a production example of a pigment dispersion using a pigment dispersant is shown as Production Example 6.
<Production Example 6> Dispersant pigment dispersion liquid (Yellow dispersion liquid 2, magenta dispersion liquid 2, cyan dispersion liquid 2 by surfactant dispersion, yellow dispersion liquid 3, magenta dispersion liquid 3, cyan dispersion liquid 3 by polymer dispersion)
The following pigments and dispersants were used.
Yellow pigment: C.I. I. Pigment Yellow 128, magenta pigment: C.I. I. Pigment Red 122, cyan pigment: C.I. I. Pigment Blue 15: 3
Dispersant A: Nonionic surfactant "Emulgen 913" manufactured by Kao Corporation), HLB 15.5
Dispersant B: Acrylic resin aqueous solution “Johncryl 611” (ammonia neutralized, solid content 20%) manufactured by Johnson Polymer, acid value 57
[0087]
A pigment dispersion was produced by the following steps using the above pigment and dispersant.
(1) Salt milling refinement process
250 parts of the above pigment, 2500 parts of sodium chloride and 200 parts of diethylene glycol were charged into a stainless steel 1 gallon kneader (manufactured by Inoue Seisakusho) and kneaded for 3 hours. Next, the mixture was poured into 2.5 liters of warm water, stirred for about 1 hour with a high-speed mixer while heating to about 80 ° C. to form a slurry, and then filtered and washed with water five times to repeat sodium chloride and Except for the solvent, a dried pigment product was obtained.
[0088]
(2) Surface treatment process
To a paint conditioner, 20 parts of the pigment, the dispersants of A and B and water were added, and the total amount was 100 parts, followed by dispersion for 3 hours. The obtained aqueous pigment dispersion was subjected to centrifugation at 15000 rpm for 6 hours.
To 20 parts of the surface-treated pigment, 0.1 part of 30% aqueous ammonia and 79.9 parts of purified water were added, and the mixture was redispersed with a paint conditioner to prepare a pigment concentrate. The concentrated solution was filtered through a 1 μm nylon filter, and subsequently filtered through a 0.5 μm polypropylene filter to obtain a dispersion for use.
[0089]
Each content of Fe, Ca, and Si was 100 ppm or less.
The average particle size of this dispersion was as follows.
Yellow dispersion 2: 93 nm Yellow dispersion 3: 80 nm
Magenta dispersion 2: 60 nm Magenta dispersion 3: 56 nm
Cyan dispersion 2: 90 nm Cyan dispersion 3: 87 nm
[0090]
In the present invention, fine particles colored with dyes and pigments are used as coloring materials to improve fixability on plain paper, improve coloring properties, and adjust the concentration of monovalent anions to prevent the occurrence of aggregation and the like. A recording liquid can be obtained. As the colored fine particles, any of fine particles composed of a polymer and those composed of inorganic fine particles such as silica and alumina can be used. For the purpose of imparting gloss, it is preferable to use polymer fine particles.
[0091]
In particular, it is preferable to use acrylic or polyester-based fine particles impregnated with a dye / pigment, that is, colored polymer fine particles in which the dye / pigment exists in the surface layer, inside, or as a whole. More specifically, colored fine particles produced by the method disclosed in JP-A-2000-53898 can be mentioned.
[0092]
Hereinafter, a production example of colored fine particles according to this is shown as Production Example 7.
<Production Example 7>
In a sealable reaction vessel equipped with a stirring blade, a cooling pipe, and a nitrogen gas introduction pipe, 20 parts by weight of methyl ethyl ketone as a polymerization solvent, and an initially charged monomer and a polymerization chain transfer agent having the following composition as a polymerizable unsaturated monomer were charged. Gas replacement was sufficiently performed.
[0093]
Methyl methacrylate, monomer 12.8 parts by weight
2-hydroxyethyl methacrylate, monomer 1.2 parts by weight
Methacrylic acid, monomer 2.9 parts by weight
2 parts by weight of silicone macromer (FM-0711 manufactured by Chisso Corporation)
Styrene acrylonitrile macromer 1 part by weight
(AN-6 manufactured by Toa Gosei Co., Ltd.)
0.3 parts by weight of mercaptoethanol (polymerization chain transfer agent)
[0094]
Next, the temperature of the mixed solution in the reaction vessel was raised to 65 ° C. while stirring in a nitrogen atmosphere.
Separately, the following dropping monomer and polymerization chain transfer agent, methyl ethyl ketone (60 parts), and 2,2′-azobis (2,4-dimethylvaleronitrile) (0.2 part) are mixed and sufficiently substituted with nitrogen. The obtained mixture was gradually dropped into the reaction vessel over 3 hours.
[0095]
Methyl methacrylate, monomer 51 parts by weight
2-hydroxyethyl methacrylate, monomer 4.2 parts by weight
Methacrylic acid, monomer 11 parts by weight
8 parts by weight of silicone macromer (FM-0711 manufactured by Chisso Corporation)
Styrene acrylonitrile macromer 4 parts by weight
(AN-6 manufactured by Toa Gosei Co., Ltd.)
1.2 parts by weight of mercaptoethanol (polymerization chain transfer agent)
[0096]
Two hours after the completion of the dropwise addition, a solution prepared by dissolving 0.1 part by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) in 5 parts by weight of methyl ethyl ketone was added, and further added at 70 ° C. for 2 hours at 65 ° C. For 2 hours to obtain a vinyl polymer solution.
A part of the obtained vinyl polymer solution was dried under reduced pressure at 105 ° C. for 2 hours, and was isolated by completely removing the solvent. The weight average molecular weight was about 10,000 and Tg was 180 ° C.
[0097]
25 g of toluene and an anthraquinone dye were added to 5 g of the vinyl polymer obtained by drying the vinyl polymer solution obtained above under reduced pressure.
[0098]
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[0099]
5 g was added to completely dissolve, and 2 g of an aqueous sodium hydroxide solution was added to partially neutralize acidic groups of the vinyl polymer. Next, 300 g of ion-exchanged water was added, and the mixture was stirred, and then emulsified for 30 minutes using a nano maker TM (manufactured by Nanomizer) as an emulsifying apparatus. The resulting emulsion was completely removed by removing toluene at 60 ° C. under reduced pressure, and further concentrated by removing a part of water, and impurities such as monomers were removed by an ultrafiltration membrane. To obtain a magenta dispersion 4 of vinyl polymer fine particles impregnated with (average particle size: 98 nm, solid content concentration: 20%).
[0100]
In the same manner, C.I. I. Disperse Yellow 118, Yellow Dispersion Liquid 4 (average particle size: 98 nm, solid content concentration: 20%), C.I. I. As Disperse Blue 36, Blue Dispersion Liquid 4 (average particle size: 98 nm, solid content concentration: 20%) was obtained.
[0101]
In the present invention, the use of a surfactant can improve the wettability to recording paper. Preferred surfactants include interfacial polyoxyethylene alkyl ether acetate, dialkyl sulfosuccinate, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene polyoxypropylene block copolymer, and acetylene glycol-based surfactant. Agents. More specifically, examples of the anionic surfactant include a polyoxyethylene alkyl ether acetate represented by the following general formula (II) and / or a carbon chain represented by the following general formula (III) having 5 to 7 carbon atoms. (Dialkylsulfosuccinic acid having a branched alkyl chain) improves the properties of plain paper, and also provides the dissolution and dispersion stability of the colorant.
[0102]
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[0103]
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[0104]
[0105]
Preferred nonionic surfactants include the general formula (IV) which is a polyoxyethylene alkylphenyl ether and the general formula (V) which is an acetylene glycol surfactant. By using these in combination, permeability can be further increased as a synergistic effect, whereby ink that reduces color boundary bleeding and has less character bleeding can be selected.
[0106]
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[0107]
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[0108]
The storage stability of the ink can be obtained by setting the pH of the ink to 6 or more. In addition, many copy papers and tags used in offices have a pH of 5 to 6, The ink is ejected from a fine ejection opening of 9 to 60 μm onto paper as a droplet having a weight of 2 ng to 50 ng at a flow rate of 5 to 20 m / s, and the attached amount of a single color is 1.5 g / m. ² To 30g / m ² It is possible to provide a recording method for forming a high-quality, high-resolution recording image by recording on a so-called plain paper having a degree of Stiggent size of 3 seconds or more according to the JIS P-8122 test method. However, if the pH is 9 or more, the activator of (III) is likely to undergo a change in physical properties due to decomposition during storage, so when (III) is used, the pH is preferably 6 to 9.
[0109]
The addition amount of (II), (III), (IV) and (V) which can be used in the present invention is in the range of 0.05 to 10% by weight. Can be given. Here, if the content is 0.05% or less, bleeding occurs at the boundary of the two-color overlapped portion in any case, and if 10% by weight or more is added, the compound itself may easily precipitate at a low temperature, resulting in poor reliability.
[0110]
Next, the surfactants (II) and (III) used in the present invention are specifically shown in free acid form.
[0111]
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[0112]
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[0113]
The ink of the present invention uses water as a liquid medium. However, in order to make the ink have desired physical properties, to prevent drying of the ink, and to improve the dissolution stability of the compound of the present invention. The following water-soluble organic solvents can be used for the purpose of the above.
[0114]
Ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,3-pulpanediol, 1,3-butanediol, 1,4 butanediol, 1,5 pentane Polyvalents such as diol, 1,6 hexanediol, glycerol, 1,2,6-hexanetriol, 1,2,4-butanthrol, 1,2,3-butanthrol and petriol Alcohols, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether Multivalent Al such as Tel Polyalkyl alcohol ethers such as -alkyl ethers, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether; N-methyl-2-pyrrolidone, N-hydroxyethyl-2 Nitrogen-containing heterocyclic compounds such as -pyrrolidone, 2-pyrrolidone, 1,3-dimethylimidazolidinone, ε-caprolactam; amides such as formamide, N-methylformamide, formamide, N, N-dimethylformamide; monoethanolamine Amines such as diethanolamine, triethanolamine, monoethylamine, diethylamine and triethylamine; sulfur-containing compounds such as dimethyl sulfoxide, sulfolane and thiodiethanol; propylene carbonate; ethylene carbonate; and γ-butyrolactone.
These solvents are used alone or in combination with water.
[0115]
Of these, particularly preferred are diethylene glycol, thiodiethanol, polyethylene glycol 200 to 600, triethylene glycol, glycerol, 1,2,6-hexanetriol, 1,2,4 -Butantriol, petriol, 1,3 butanediol, 2,3 butanediol, 1,4-butanediol, 1,5-pentaneddiol, N-methyl-2-pyrrolidone, N-hydroxyethylpyrrolidone, 2 -Pyrrolidone, 1,3-dimethylimidazolidinone, and by using these, excellent effects can be obtained on the high solubility of the present compound and the prevention of poor jetting characteristics due to water evaporation.
Particularly, in the present invention, a preferable solvent for obtaining the dispersion stability of the colorant is a pyrrolidone derivative such as N-hydroxyethyl 2-pyrrolidone.
[0116]
Examples of the penetrant added for the purpose of adjusting the surface tension other than the surfactants (II) to (V) of the present invention include diethylene glycol monophenyl ether, ethylene glycol monophenyl ether, and ethylene glycol. Polyhydric alcohols such as glycol monoallyl ether, diethylene glycol monophenyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, triethylene glycol monobutyl ether and tetraethylene glycol chlorophenyl ether Diols such as alkyl and aryl ethers, 2-ethyl-1,3 hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2 dimethyl 1,3 propanediol and poly; Oxyethylene polyoxypropylene block Lower alcohols such as coalescable, fluorine-based surfactants, ethanol, and 2-propanol. Particularly preferred are diethylene glycol monobutyl ethers having 6 or more carbon atoms as polyhydric alcohol alkyl ethers. The diols are 2-ethyl-1,3 hexanediol and 2,2,4-trimethyl-1,3 pentanediol.
[0117]
The diols are suitable because the aggregation of the water-insoluble coloring material hardly occurs. The amount of addition depends on the type and desired physical properties, but is added in the range of 0.1% by weight to 20% by weight, preferably 0.5% by weight to 10% by weight. If it is less than the lower limit, the permeability is insufficient, and if it is more than the upper limit, the particle formation characteristics are adversely affected. In addition, the addition thereof improves the wettability to the ink jet head member and the recording apparatus, improves the filling property, and makes it difficult for recording defects due to bubbles to occur.
[0118]
The physical properties of the ink in the present invention can be appropriately adjusted by the system. Here, the surface tension of the ink is an index indicating the permeability to the paper. In particular, measuring the dynamic surface tension in a short time of 1 second or less after the surface is formed corresponds to the permeability of the ink. Different from static surface tension measured at saturation time. As a measuring method, any method can be used as long as it can measure a dynamic surface tension of 1 second or less by a conventionally known method described in JP-A-63-313372. The surface tension is preferably 50 mN / m or less, and more preferably 40 mN / m or less, whereby excellent drying properties can be obtained. On the other hand, if the dynamic surface tension is too low from the ejection stability of the ink, the particle formation tends to be unstable. The dynamic surface tension that enables stable ejection is preferably 40 mN / m or more in 1 msec.
[0119]
The range of the viscosity is appropriately selected from 1 mPa · s to 10 mPa · s depending on the ejection method.
The pigment particles in the ink have a particle size range of 10 nm to 300 nm, and preferably have an average particle size of 60 nm to 120 nm. The solid content in the ink is 1 to 25% by weight, and the water content is in the range of 25 to 93% by weight, more preferably 50 to 80% by weight.
[0120]
In the present invention, if the electric conductivity range does not impair the dispersion stability in the range of 1 mS / cm to 6 mS / cm from the relationship between the イ ン ク potential of the pigment ink in the ink and the particle surface of the colored fine particle ink, the occurrence of aggregation of the pigment and the like will occur. It is possible to obtain a highly reliable ink with a small change in particle diameter over a long period of time without causing any problem. Usually, an electric conductivity adjuster or the like is added to make the content within this range. Preferred conductivity adjusters include quaternary ammonium salts such as tetramethylammonium chloride, and alkanolamine salts.
[0121]
Conventionally known additives can be added to the ink of the present invention in addition to the coloring agent and the solvent.
For example, as the antiseptic / fungicide, sodium dehydroacetate, sodium sorbate, sodium 2-pyridinethiol-1-oxide, sodium benzoate, sodium pentachlorophenol, isothiazoline and the like can be used in the present invention.
[0122]
In addition, as the pH adjuster, any substance can be used as long as it can adjust the pH to 7 or more without affecting the prepared ink.
Examples thereof include amines such as diethanolamine and triethanolamine, hydroxides of alkali metal elements such as lithium hydroxide and sodium hydroxide, ammonium hydroxide, quaternary ammonium hydroxide, and quaternary phosphonium hydroxide. And alkali metal carbonates such as lithium carbonate, sodium carbonate and potassium carbonate.
[0123]
Examples of chelating reagents include sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, and sodium uramildiacetate.
[0124]
Examples of the rust preventive include acid sulfite, sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, dicyclohexylammonium nitrite and the like.
[0125]
In addition, a water-soluble ultraviolet absorber, a water-soluble infrared absorber, and an antifoaming agent can be added according to the purpose.
Examples of the defoaming agent include oils and fats, fatty acids, fatty acid esters, alcohols, phosphates, amines, amides, metal soaps, sulfates, and silicones. These can be used alone or in combination of two or more. Among them, a silicone-based antifoaming agent having a siloxane bond is preferable because of easy control of the negative pressure of the sponge absorber in the ink tank. In particular, a polysiloxane-based antifoaming agent to which polyethylene oxide and / or polypropylene oxide is added is effective.
[0126]
The content of the antifoaming agent in the ink is 0.00001 to 10% by weight, more preferably 0.0001 to 5% by weight. If the content is less than 0.00001% by weight, a sufficient antifoaming effect is not exhibited. If the amount is more than 10% by weight, problems such as a decrease in the solubility and dispersion stability of the coloring material and a decrease in the ejection stability of the ink occur. Further, in order to hold the ink in the ink absorber, the above content is determined from the fiber density, structure, etc. of the sponge absorber made of urethane or polypropylene fiber used for the ink absorber, and the affinity of the defoaming agent for this. The optimum amount of the antifoaming agent may be determined within the range described above.
[0127]
The 2-amino-2-ethyl-1,3-propanediol in the present invention 9 is a pH adjuster. Further, N-cyclohexyl-2-aminoethanesulfonic acid in the present invention 10 is a buffer. Further, the benzotriazole in the eleventh invention is a rust inhibitor.
[0128]
Next, an example of the inkjet recording apparatus of the present invention suitable for performing recording using the above-described aqueous pigment ink of the present invention will be described below. First, FIG. 1 shows an example of a configuration of a head which is a main part of an ink jet recording apparatus using thermal energy. FIG. 1 is a cross-sectional view of the head 13 along an ink flow path. The head 13 adheres a heating element substrate 15 to a glass, ceramic, silicon, or plastic plate having a flow path (nozzle) 14 through which ink passes. Obtained. The heating element substrate 15 includes a protective layer 16 formed of silicon oxide, silicon nitride, silicon carbide, and the like, electrodes 17-1 and 17-2 formed of aluminum, gold, an aluminum-copper alloy, and the like, and HfB. ₂ , TaN, TaAl, etc., a heating resistor layer 18 formed of a high melting point material, a thermal storage layer 19 formed of thermally oxidized silicon, aluminum oxide, or the like, and a material having good heat dissipation properties, such as silicon, aluminum, or aluminum nitride. Substrate 20.
[0129]
When a pulse-like electric signal is applied to the electrodes 17-1 and 17-2 of the head 13, a region indicated by n of the heating element substrate 15 rapidly generates heat, and bubbles are generated in the ink 21 in contact with the surface. Is generated, the meniscus 23 protrudes by the pressure, and the ink 21 is ejected through the nozzle 14 of the head, becomes the ink droplet 24 from the ejection orifice 22, and flies toward the recording material 25.
[0130]
FIG. 2 shows an example of an ink jet recording apparatus incorporating this head. In FIG. 2, reference numeral 61 denotes a blade as a wiping member, one end of which is held and fixed by a blade holding member, and forms a cantilever. The blade 61 is arranged at a position adjacent to a recording area of the recording head 65, and in this example, is held in a form protruding into the movement path of the recording head 65.
[0131]
Reference numeral 62 denotes a cap on the protruding opening surface of the recording head 65, which is disposed at a home position adjacent to the blade 61, moves in a direction perpendicular to the moving direction of the recording head 65, abuts on the ink ejection opening surface, and performs capping. It has a configuration to perform. Further, reference numeral 63 denotes an ink absorber provided adjacent to the blade 61, and is held in a form protruding into the movement path of the recording head 65, similarly to the blade 61. The blade 61, the cap 62, and the ink absorber 63 constitute an ejection recovery unit 64, and the blade 61 and the ink absorber 63 remove moisture, dust, and the like from the ejection port surface.
[0132]
Reference numeral 65 denotes a recording head which has ejection energy generating means and performs recording by discharging ink on a recording material opposed to a discharge port surface provided with discharge ports, and 66 denotes a recording head 65 on which the recording head 65 is mounted. This is a carriage for performing movement. The carriage 66 is slidably engaged with the guide shaft 67, and a part of the carriage 66 is connected to a belt 69 driven by a motor 68 (not shown). As a result, the carriage 66 can move along the guide shaft 67, and the recording head 65 can move the recording area and the adjacent area.
[0133]
Reference numeral 51 denotes a paper feed unit for inserting a recording material, and reference numeral 52 denotes a paper feed roller driven by a motor (not shown). With such a configuration, the recording material is fed to a position facing the discharge port surface 65 of the recording head, and is discharged to a discharge section provided with a discharge roller 53 as recording proceeds. In the above configuration, when the recording head 65 finishes recording and returns to the home position, the cap 62 of the ejection recovery unit 64 is retracted from the moving path of the recording head 65, but the blade 61 protrudes into the moving path. As a result, the ejection openings of the recording head 65 are wiped.
[0134]
When capping is performed with the cap 62 in contact with the ejection surface of the recording head 65, the cap 62 moves so as to protrude into the movement path of the recording head. When the recording head 65 moves from the home position to the recording start position, the cap 62 and the blade 61 are at the same positions as the positions at the time of the wiping described above. As a result, the ejection port surface of the recording head 65 is also wiped during this movement. The above-described movement of the print head to the home position is performed not only at the end of printing and at the time of ejection recovery, but also at a predetermined interval while the print head moves through the printing area for printing to the home position adjacent to the printing area. Then, the wiping is performed along with this movement.
[0135]
FIG. 3 is a diagram illustrating an example of an ink cartridge that stores ink supplied to a recording head via an ink supply member, for example, a tube. Here, reference numeral 40 denotes an ink storage unit storing the supply ink, for example, an ink bag, and a rubber stopper 42 is provided at the end thereof. By inserting a needle (not shown) into the stopper 42, the ink in the ink bag 40 can be supplied to the head. An ink absorber 44 receives the waste ink. It is preferable that the ink container has a surface in contact with the ink made of polyolefin, particularly polyethylene.
[0136]
The ink jet recording apparatus used in the present invention is not limited to the one in which the head and the ink cartridge are separated as described above, and is also suitably used in an integrated one as shown in FIG. Can be In FIG. 4, reference numeral 70 denotes a recording unit, in which an ink storage unit for storing ink, for example, an ink absorber is stored, and the ink in the ink absorber is transferred from a head unit 71 having a plurality of orifices. It is configured to be discharged as droplets. It is preferable for the present invention to use polyurethane, cellulose, polyvinyl acetate or polyolefin resin as the material of the ink absorber. Further, a structure may be employed in which the ink storage unit is an ink bag in which a spring or the like is provided inside without using an ink absorber. Reference numeral 72 denotes an atmosphere communication port for communicating the inside of the cartridge with the atmosphere. This recording unit 70 is used in place of the recording head 65 shown in FIG. 2, and is detachable from the carriage 66.
[0137]
Next, as a preferable example of an ink jet recording apparatus using mechanical energy, a nozzle forming substrate having a plurality of nozzles, a pressure generating element made of a piezoelectric material and a conductive material disposed to face the nozzles, An on-demand ink jet recording apparatus that includes ink filling around the generating element, displaces the pressure generating element by an applied voltage, and discharges a small droplet of ink from a nozzle can be given. FIG. 5 shows an example of a configuration of a recording head which is a main part of the recording apparatus.
[0138]
The head includes an ink flow path 80 communicating with an ink chamber (not shown), an orifice plate 81 for discharging ink droplets of a desired volume, a vibration plate 82 for directly applying pressure to ink, and a vibration plate 82 And a substrate 84 for supporting and fixing the orifice plate 81, the vibration plate 82 and the like.
[0139]
In FIG. 5, an ink flow path 80 is formed of a photosensitive resin or the like, and an orifice plate 81 has a discharge port 85 formed by electroforming or pressing a metal such as stainless steel or nickel. Is provided with an ink repellent layer such as eutectoid plating. The vibration plate 82 is formed of a metal film such as stainless steel, nickel, or titanium, and a high elastic resin film, and the piezoelectric element 83 is formed of a dielectric material such as barium titanate or PZT. The recording head having the above-described configuration applies a pulse-like voltage to the piezoelectric element 83 to generate a strain stress, and the energy of the energy deforms the diaphragm joined to the piezoelectric element 83, causing the ink in the ink flow path 80 to move. Is pressed vertically, and an ink droplet (not shown) is ejected from the ejection port 85 of the orifice plate 81 to perform printing. Such a recording head is used by being incorporated in an ink jet recording apparatus similar to that shown in FIG. The detailed operation of the ink jet recording apparatus may be the same as that described above.
[0140]
Next, an ink jet using an electrostatic actuator will be described as a preferred example of an ink jet recording apparatus using other mechanical energy. FIG. 1 is a cross-sectional view of an ink jet head to which the present invention is applied. As shown in these figures, an ink jet head 1 has a silicon substrate 2 sandwiched therebetween, a nozzle plate 3 also made of silicon on the upper side, and silicon on the lower side. It has a three-layer structure in which borosilicate glass substrates 4 having close thermal expansion coefficients are laminated. In the central silicon substrate 2, a plurality of independent ink chambers 5, a common ink chamber 6 provided in common therewith, and an ink supply path 7 connecting the common ink chamber 6 to the plurality of ink chambers 5, respectively. Are formed by etching from the surface (upper surface in the figure). These grooves are closed by the nozzle plate 3 to define the respective portions 5, 6, and 7.
[0141]
In the nozzle plate 3, ink nozzles 11 are formed at positions corresponding to the front end portions of the respective ink chambers 5, and these are communicated with the respective ink chambers 5. In addition, an ink supply port communicating with the common ink chamber 6 is formed in the nozzle plate 3. The ink is supplied from an external ink tank (not shown) to the common ink chamber 6 through an ink supply port. The ink supplied to the common ink chamber 6 is supplied to the independent ink chambers 5 through the ink supply path 7.
[0142]
The ink chamber 5 is formed thin so that its bottom wall 8 functions as a diaphragm that can be elastically displaced in the vertical direction in FIG. Therefore, the bottom wall 8 may be referred to as a diaphragm 8 for convenience of the following description.
[0143]
Next, in the glass substrate 4 which is in contact with the lower surface of the silicon substrate 2, the upper surface thereof, that is, the bonding surface with the silicon substrate 2 was shallowly etched at a position corresponding to each ink chamber 5 of the silicon substrate 2. A recess 9 is formed. Therefore, the bottom wall 8 of each ink chamber 5 faces the surface 92 of the concave portion 9 of the glass substrate 4 with a very small gap. Since the concave portion 9 of the glass substrate 4 faces the bottom wall 8 of the ink chamber 5, it is referred to as a diaphragm facing wall or simply a facing wall 91.
[0144]
Here, the bottom wall 8 of each ink chamber 5 functions as an electrode for storing a charge. A segment electrode 10 is formed on the concave surface 92 of the glass substrate 4 so as to face the bottom wall 8 of each ink chamber 5. The surface of each segment electrode 10 is covered with an insulating layer made of inorganic glass and having a thickness of G0. As described above, the segment electrode 10 and the bottom wall 8 of each ink chamber form a counter electrode (the distance between the electrodes is G) with the insulating layer 15 interposed therebetween.
[0145]
Hereinafter, examples and comparative examples of the present invention will be described.
Embodiment 1
(Preparation of Black Ink 1)
[0146]
After mixing using the following composition and leaving it to stand for 1 day, the mixture was adjusted to pH 9 with lithium hydroxide and filtered through a 0.5 μm polypropylene filter to obtain [Black Ink 1].
[0147]
Carbon dispersion liquid 1 (as solid content concentration in ink) 10% by weight
15% by weight of 2-methyl-2,4-pentanediol
Glycerol 15% by weight
2-ethyl-1,3 hexanediol 1% by weight
5% by weight of N-hydroxyethylpyrrolidone
Activator of specific example (II-2) 1% by weight
0.2% by weight of sodium dehydroacetate
0.6% by weight of 2-amino-2-ethyl-1,3-propanediol
N-cyclohexyl-2-aminoethanesulfonic acid 0.05% by weight
Benzotriazole 0.05% by weight
0.1% by weight of defoamer (KM-72F)
High purity water (10MΩ)
[0148]
Using a centrifugal ultrafiltration unit (ultra-free 15 / fraction molecular weight 10,000) (manufactured by Nippon Millipore), the liquid component and the pigment were separated from the obtained black ink 1, and the liquid component was ionized. The free anion concentration was measured using a chromatograph DX-500 (manufactured by Nippon Dionex KK). The free anion concentration, that is, the chloride ion concentration was 10 ppm or less.
Hereinafter, the concentrations of the dispersion and the dye are the concentration of the solid content of the coloring material in the ink.
[0149]
Embodiment 2
(Preparation of Black Ink 2)
[Black Ink 2] was prepared in the same manner as in Example 1 except that the following composition was used, and the pH was adjusted to 8.8 with lithium hydroxide.
[0150]
Carbon dispersion 2 10% by weight
14% by weight of 2-methyl-2,4-pentanediol
1,2,6-hexanetriol 8% by weight
1,5-pentanediole 8% by weight
2-ethyl-1,3-hexanediol 2% by weight
8% by weight of 2-pyrrolidone
Activator of specific example (II-3) 1.0% by weight
Activator of specific example (III-1) 1.2% by weight
Urea 5% by weight
Sodium 2-pyridinethiol-1-oxide 0.2% by weight
0.6% by weight of 2-amino-2-ethyl-1,3-propanediol
N-cyclohexyl-2-aminoethanesulfonic acid 0.05% by weight
Benzotriazole 0.05% by weight
0.1% by weight of defoamer (KM-72F)
High purity water (10MΩ)
[0151]
Using a centrifugal ultrafiltration unit (ultra-free 15 / fraction molecular weight 10,000) (manufactured by Nippon Millipore), a liquid component and a pigment were separated from the obtained black ink 2, and the liquid component was ionized. The free anion concentration was measured using a chromatograph DX-500 (manufactured by Nippon Dionex KK). The free anion concentration, that is, the sulfate ion concentration was 100 ppm or less.
[0152]
Embodiment 3
(Preparation of Black Ink 3)
[Black ink 3] was prepared in the same manner as in Example 1 except that the following composition was used and the pH was adjusted to 9.5 with lithium hydroxide.
12% by weight of carbon dispersion 3
[0153]
20% by weight of 2-methyl-2,4-pentanediol
Diethylene glycol 5% by weight
Glycerol 5% by weight
2-ethyl-1,3-hexanediol 3% by weight
2-pyrrolidone 2% by weight
Styrene acrylic acid polymer 0.5% by weight
1% by weight of surfactant (II-2)
Activator of (VI) R: C ₉ H ₁₉ k: 12 1% by weight
0.2% by weight of sodium dehydroacetate
0.6% by weight of 2-amino-2-ethyl-1,3-propanediol
N-cyclohexyl-2-aminoethanesulfonic acid 0.05% by weight
Benzotriazole 0.05% by weight
0.1% by weight of defoamer (KM-72F)
Deionized water remaining
[0154]
Using a centrifugal ultrafiltration unit (ultra-free 15 / fraction molecular weight 10,000) (manufactured by Nippon Millipore), a liquid component and a pigment were separated from the obtained black ink 3, and the liquid component was ionized. The free anion concentration was measured using a chromatograph DX-500 (manufactured by Nippon Dionex KK). The free anion concentration, that is, the nitrate ion concentration was 10 ppm or less.
[0155]
Embodiment 4
(Preparation of yellow ink 1, magenta ink 1, and cyan ink 1)
<Yellow ink 1>
[Yellow Ink 1] was prepared in the same manner as in Example 1 except that the following composition was used and the pH was adjusted to 9.5 with lithium hydroxide.
[0156]
Yellow dispersion 1 10% by weight
13% by weight of 2-methyl-2,4-pentanediol
Ethylene glycol 5% by weight
Glycerol 2% by weight
1,5-pentanediol 8% by weight
2-ethyl-1,3-hexanediol 3% by weight
2-pyrrolidone 2% by weight
1% by weight of polyoxyethylene polyoxyethylene block copolymer
Activator of specific example (II-4) 1% by weight
Activator of specific example (V) p, q = 20 0.8% by weight
Urea 5% by weight
Sodium benzoate 0.2% by weight
0.6% by weight of 2-amino-2-ethyl-1,3-propanediol
N-cyclohexyl-2-aminoethanesulfonic acid 0.05% by weight
Benzotriazole 0.05% by weight
0.1% by weight of defoamer (KM-72F)
Deionized water remaining
[0157]
<Magenta ink 1>
[Magenta Ink 1] was prepared in the same manner as in Example 1 except that the following composition was used, and the pH was changed to 9.1 with lithium hydroxide.
[0158]
Magenta dispersion 1 10% by weight
15% by weight of 2-methyl-2,4-pentanediol
Ethylene glycol 5% by weight
Glycerol 15% by weight
2-ethyl-1,3-hexanediol 3% by weight
2-pyrrolidone 2% by weight
1% by weight of polyoxyethylene polyoxyethylene block copolymer
Activator of specific example (II-4) 1% by weight
Activator of specific example (V) p, q = 20 0.8% by weight
Urea 5% by weight
Sodium benzoate 0.2% by weight
0.6% by weight of 2-amino-2-ethyl-1,3-propanediol
N-cyclohexyl-2-aminoethanesulfonic acid 0.05% by weight
Benzotriazole 0.05% by weight
0.1% by weight of defoamer (KM-72F)
Deionized water remaining
[0159]
<Cyan ink 1>
[Cyan Ink 1] was prepared by adjusting the pH to 9.2 with lithium hydroxide in the same manner as in Example 1 except that the following composition was used.
[0160]
Cyan dispersion 1 10% by weight
15% by weight of 2-methyl-2,4-pentanediol
Glycerol 15% by weight
2-ethyl-1,3-hexanediol 1% by weight
5% by weight of N-hydroxyethylpyrrolidone
Activator of specific example (II-2) 1% by weight
0.2% by weight of sodium dehydroacetate
0.6% by weight of 2-amino-2-ethyl-1,3-propanediol
N-cyclohexyl-2-aminoethanesulfonic acid 0.05% by weight
Benzotriazole 0.05% by weight
0.1% by weight of defoamer (KM-72F)
High purity water (10MΩ)
[0161]
Embodiment 5
(Preparation of Yellow Ink 2, Magenta Ink 2, and Cyan Ink 2)
<Yellow ink 2>
[Yellow Ink 2] was prepared in the same manner as in Example 1 except that the following composition was used, and the pH was changed to 7.8 with sodium hydroxide.
[0162]
Yellow dispersion 2 10% by weight
15% by weight of 2-methyl-2,4-pentanediol
Triethylene glycol 5% by weight
Petriol 10% by weight
2-ethyl-1,3-hexanediol 3% by weight
5% by weight of N-methyl-2-pyrrolidone
Diethylene glycol monobutyl ether 2% by weight
Activator of specific example (IV) R: C ₁₀ H ₂₁ K: 7 1% by weight
Hydroxyethyl urea 5% by weight
Sodium 2-pyridinethiol-1-oxide 0.2% by weight
Deionized water remaining
[0163]
<Magenta ink 2>
[Magenta Ink 2] was prepared in the same manner as in Example 1 except that the following composition was used and the pH was adjusted to 8.5 with sodium hydroxide.
[0164]
Magenta dispersion 2 10% by weight
15% by weight of 2-methyl-2,4-pentanediol
Triethylene glycol 5% by weight
Petriol 10% by weight
2-ethyl-1,3-hexanediol 3% by weight
5% by weight of N-methyl-2-pyrrolidone
Diethylene glycol monobutyl ether 2% by weight
Activator of specific example (IV) R: C ₁₀ H ₂₁ K: 7 1% by weight
Hydroxyethyl urea 5% by weight
Sodium 2-pyridinethiol-1-oxide 0.2% by weight
Deionized water remaining
[0165]
<Cyan ink 2>
[Cyan Ink 2] was prepared in the same manner as in Example 1 except that the following composition was used, and the pH was adjusted to 8.2 with sodium hydroxide.
[0166]
Cyan dispersion 2 10% by weight
15% by weight of 2-methyl-2,4-pentanediol
Triethylene glycol 5% by weight
Petriol 10% by weight
2-ethyl-1,3-hexanediol 3% by weight
5% by weight of N-methyl-2-pyrrolidone
Diethylene glycol monobutyl ether 2% by weight
Activator of specific example (V) R: C ₁₀ H ₂₁ K: 7 1% by weight
Hydroxyethyl urea 5% by weight
Sodium 2-pyridinethiol-1-oxide 0.2% by weight
Deionized water remaining
[0167]
Embodiment 6
(Preparation of Yellow Ink 3, Magenta Ink 3, and Cyan Ink 3)
<Yellow ink 3>
[Yellow Ink 3] was prepared in the same manner as in Example 1 except that the following composition was used, and the pH was adjusted to 8 with lithium hydroxide.
[0168]
Yellow dispersion 3 11% by weight
20% by weight of 2-methyl-2,4-pentanediol
Glycerol 7% by weight
1,3-butanediol 3% by weight
2-ethyl-1,3-hexanediol 3% by weight
8% by weight of 2-pyrrolidone
Activator of specific example (II-1) 0.3% by weight
(IV) Activator p + q = 15 0.5% by weight
(IV) Activator p + q = 0 0.5% by weight
Hydroxyethyl urea 5% by weight
0.2% by weight of sodium dehydroacetate
Deionized water remaining
[0169]
<Magenta ink 3>
[Magenta Ink 3] was prepared in the same manner as in Example 1 except that the following composition was used and the pH was changed to 8 with lithium hydroxide.
[0170]
Magenta dispersion 3 11% by weight
20% by weight of 2-methyl-2,4-pentanediol
Glycerol 7% by weight
1,3 butanediol 3% by weight
2-ethyl-1,3-hexanediol 3% by weight
8% by weight of 2-pyrrolidone
(IV) Activator p + q = 15 0.5% by weight
(IV) Activator p + q = 0 0.5% by weight
Hydroxyethyl urea 5% by weight
0.2% by weight of sodium dehydroacetate
Deionized water remaining
[0171]
<Cyan ink 3>
[Cyan Ink 3] was prepared by adjusting the pH to 8 with lithium hydroxide in the same manner as in Example 1 except for using the following composition.
[0172]
Cyan dispersion 3 11% by weight
20% by weight of 2-methyl-2,4-pentanediol
Glycerol 7% by weight
1,3 butanediol 3% by weight
2-ethyl-1,3-hexanediol 3% by weight
8% by weight of 2-pyrrolidone
Activator of specific example (II-1) 0.3% by weight
0.4% by weight of tetramethylammonium nitrate (conductivity regulator)
(IV) Activator p + q = 15 0.5% by weight
(IV) Activator p + q = 0 0.5% by weight
Hydroxyethyl urea 5% by weight
0.2% by weight of sodium dehydroacetate
Deionized water remaining
[0173]
Embodiment 7
(Preparation of Yellow Ink 4, Magenta Ink 4, and Cyan Ink 4)
<Yellow ink 4>
[Yellow Ink 4] was prepared by adjusting the pH to 9.5 with lithium hydroxide in the same manner as in Example 1 except for using the following composition.
[0174]
Yellow dispersion 4 12% by weight
15% by weight of 2-methyl-2,4-pentanediol
Ethylene glycol 5% by weight
Glycerol 2% by weight
1,3-propanediol 8% by weight
2-ethyl-1,3-hexanediol 3% by weight
2-pyrrolidone 2% by weight
1% by weight of polyoxyethylene polyoxyethylene block copolymer
Activator of specific example (II-4) 0.5% by weight
Urea 5% by weight
Sodium benzoate 0.2% by weight
Deionized water remaining
[0175]
<Magenta ink 4>
[Magenta Ink 4] was prepared in the same manner as in Example 1 except that the following composition was used and the pH was changed to 9.1 with lithium hydroxide.
[0176]
Magenta dispersion 4 12% by weight
2-methyl-2,4-pentanediol 10% by weight
Ethylene glycol 5% by weight
Glycerol 15% by weight
2-ethyl-1,3-hexanediol 3% by weight
2-pyrrolidone 2% by weight
1% by weight of polyoxyethylene polyoxyethylene block copolymer
Activator of specific example (II-4) 0.3% by weight
Activator of specific example (V) p, q = 20 0.2% by weight
Urea 5% by weight
Sodium benzoate 0.2% by weight
Deionized water remaining
[0177]
<Cyan ink 4>
[Cyan Ink 4] was prepared by adjusting the pH to 8.4 with lithium hydroxide in the same manner as in Example 1 except for using the following composition.
[0178]
Cyan dispersion 4 12% by weight
15% by weight of 2-methyl-2,4-pentanediol
Glycerol 15% by weight
2-ethyl-1,3-hexanediol 1% by weight
5% by weight of N-hydroxyethylpyrrolidone
Activator of specific example (II-2) 1% by weight
0.2% by weight of sodium dehydroacetate
High purity water (10MΩ)
[0179]
Embodiment 8
(Preparation of yellow ink 5, magenta ink 5, cyan ink 5, black ink 4)
<Yellow ink 5>
[0180]
[Yellow Ink 5] was prepared in the same manner as in Example 1 except that the following composition was used and the pH was changed to 7.8 with sodium hydroxide.
[0181]
5% by weight of dye of specific example Y1
5% by weight of dye of specific example Y2
Lactic acid 1% by weight
18% by weight of 2-methyl-2,4-pentanediol
1,5 pentanediol 5% by weight
7% by weight of trimethylolpropane
2-ethyl-1,3-hexanediol 3% by weight
5% by weight 2-pyrrolidone
Diethylene glycol monobutyl ether 2% by weight
Specific Example (IV) Activator p + q = 15 0.5% by weight
Activator of specific example (IV) R: C ₁₀ H ₂₁ K: 7 1% by weight
Hydroxyethyl urea 2% by weight
Sodium 2-pyridinethiol-1-oxide 0.2% by weight
Deionized water remaining
[0182]
<Magenta ink 5>
[Magenta Ink 5] was prepared in the same manner as in Example 1 except that the following composition was used, and the pH was changed to 7.8 with lithium hydroxide.
[0183]
Dye of specific example M5 6% by weight
C. I. Acid Red 52 4% by weight
18% by weight of 2-methyl-2,4-pentanediol
1,5 pentanediol 5% by weight
7% by weight of trimethylolpropane
2-ethyl-1,3-hexanediol 3% by weight
5% by weight 2-pyrrolidone
Diethylene glycol monobutyl ether 2% by weight
(IV) Activator p + q = 15 0.5% by weight
Activator of specific example (V) R: C ₁₀ H ₂₁ K: 7 1% by weight
Hydroxyethyl urea 5% by weight
Sodium 2-pyridinethiol-1-oxide 0.2% by weight
Deionized water remaining
[0184]
<Cyan ink 5>
[Cyan Ink 5] was prepared by adjusting the pH to 8 with lithium hydroxide in the same manner as in Example 1 except for using the following composition.
[0185]
Specific example C1 4% by weight
Specific example C2 4% by weight
Acid Blue 9 2% by weight
6% by weight calcium nitrate
18% by weight of 2-methyl-2,4-pentanediol
Triethylene glycol 5% by weight
7% by weight of trimethylolpropane
2-ethyl-1,3-hexanediol 3% by weight
5% by weight 2-pyrrolidone
Diethylene glycol monobutyl ether 2% by weight
(IV) Activator p + q = 15 0.5% by weight
Activator of specific example (IV) R: C ₁₀ H ₂₁ K: 7 1% by weight
Hydroxyethyl urea 1% by weight
Sodium 2-pyridinethiol-1-oxide 0.2% by weight
Deionized water remaining
[0186]
<Black ink 4>
[Black Ink 4] was prepared by adjusting the pH to 8 with lithium hydroxide in the same manner as in Example 1 except for using the following composition.
[0187]
5% by weight of specific example of dye BK1
5% by weight of a specific example of dye Y4
6% by weight calcium nitrate
18% by weight of 2-methyl-2,4-pentanediol
Triethylene glycol 5% by weight
7% by weight of trimethylolpropane
2-ethyl-1,3-hexanediol 3% by weight
5% by weight 2-pyrrolidone
Diethylene glycol monobutyl ether 2% by weight
(IV) Activator p + q = 15 0.5% by weight
Activator of specific example (V) R: C ₁₀ H ₂₁ K: 7 1% by weight
Hydroxyethyl urea 1% by weight
Sodium 2-pyridinethiol-1-oxide 0.2% by weight
Deionized water remaining
[0188]
Embodiment 9
(Preparation of Yellow Ink 6, Magenta Ink 6, and Cyan Ink 6)
<Yellow ink 6>
[Yellow Ink 6] was prepared in the same manner as in Example 1 except that the following composition was used and the pH was 7.2 with lithium hydroxide.
[0189]
5% by weight of a specific example of dye Y4
5% by weight of dye Y5 of a specific example
23% by weight of 2-methyl-2,4-pentanediol
Glycerol 7% by weight
2-ethyl-1,3-hexanediol 3% by weight
8% by weight of 2-pyrrolidone
Triethylene glycol monobutyl ether 10% by weight
(IV) Activator p + q = 15 0.5% by weight
(IV) Activator p + q = 0 0.5% by weight
Urea 2% by weight
0.2% by weight of sodium dehydroacetate
Deionized water remaining
[0190]
<Magenta ink 6>
[Magenta Ink 6] was prepared in the same manner as in Example 1 except that the following composition was used and the pH was adjusted to 8.1 with lithium hydroxide.
[0191]
6% by weight of dye of specific example M1
Specific example M2 dye 4% by weight
13% by weight of 2-methyl-2,4-pentanediol
Glycerol 7% by weight
2-ethyl-1,3-hexanediol 3% by weight
8% by weight of 2-pyrrolidone
3% by weight of triethylene glycol monobutyl ether
(IV) Activator p + q = 15 0.5% by weight
(IV) Activator p + q = 0 0.5% by weight
Hydroxyethyl urea 5% by weight
0.2% by weight of sodium dehydroacetate
Deionized water remaining
[0192]
<Cyan ink 6>
A cyan ink 6 was prepared in the same manner as in Example 1 except that the following composition was used and the pH was adjusted to 9.5 with lithium hydroxide.
[0193]
6% by weight of the dyestuff of Example C2
Dye of specific example C3 4% by weight
23% by weight of 2-methyl-2,4-pentanediol
Glycerol 7% by weight
2-ethyl-1,3-hexanediol 3% by weight
8% by weight of 2-pyrrolidone
3% by weight of triethylene glycol monobutyl ether
(IV) Activator p + q = 15 0.5% by weight
(IV) Activator p + q = 0 0.5% by weight
Hydroxyethyl urea 5% by weight
0.2% by weight of sodium dehydroacetate
Deionized water remaining
[0194]
Embodiment 10
(Preparation of yellow ink 7, magenta ink 7, and cyan ink 7)
<Yellow ink 7>
[Yellow Ink 7] was prepared by adjusting the pH to 9.5 with lithium hydroxide in the same manner as in Example 1 except for using the following composition.
[0195]
Dye Y7 of a specific example 4% by weight
Dye Y6 of a specific example 3% by weight
C. I. Acid Yellow 17 3% by weight
23% by weight of 2-methyl-2,4-pentanediol
Glycerol 7% by weight
2-ethyl-1,3-hexanediol 3% by weight
8% by weight of 2-pyrrolidone
Triethylene glycol monobutyl ether 10% by weight
(IV) Activator p + q = 15 0.5% by weight
(IV) Activator p + q = 0 0.5% by weight
Urea 2% by weight
0.2% by weight of sodium dehydroacetate
Deionized water remaining
[0196]
<Magenta ink 7>
[Magenta Ink 7] was prepared in the same manner as in Example 1 except that the following composition was used and the pH was adjusted to 9.5 with lithium hydroxide.
[0197]
5% by weight of dye of specific example M1
Specific example M2 dye 5% by weight
23% by weight of 2-methyl-2,4-pentanediol
Glycerol 7% by weight
2-ethyl-1,3-hexanediol 3% by weight
8% by weight of 2-pyrrolidone
3% by weight of triethylene glycol monobutyl ether
(IV) Activator p + q = 15 0.5% by weight
(IV) Activator p + q = 0 0.5% by weight
Hydroxyethyl urea 5% by weight
0.2% by weight of sodium dehydroacetate
Deionized water remaining
[0198]
<Cyan ink 7>
[Cyan Ink 7] was prepared by adjusting the pH to 9.5 with lithium hydroxide in the same manner as in Example 1 except for using the following composition.
[0199]
6% by weight of the dyestuff of Example C3
4% by weight of the dyestuff of Example C2
1% by weight calcium nitrate
23% by weight of 2-methyl-2,4-pentanediol
Glycerol 7% by weight
1,3 butanediol 3% by weight
2-ethyl-1,3-hexanediol 3% by weight
8% by weight of 2-pyrrolidone
(IV) Activator p + q = 15 0.5% by weight
(IV) Activator p + q = 0 0.5% by weight
Hydroxyethyl urea 5% by weight
0.2% by weight of sodium dehydroacetate
Deionized water remaining
[0200]
[Comparative Example 1]
(Preparation of black ink 5)
In Example 1, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, 2-amino-2-ethyl-1,3-propanediol, N-cyclohexyl-2-aminoethane Except for the sulfonic acid, benzotriazole and antifoaming agent, chloride ion mixed as free anion was added in the form of potassium chloride to adjust the free anion concentration, that is, the chloride ion concentration to about 800 ppm. Black Ink 5].
[0201]
[Comparative Example 2]
(Preparation of Black Ink 6)
In Example 2, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, 2-amino-2-ethyl-1,3-propanediol, N-cyclohexyl-2-aminoethane Except for the sulfonic acid, benzotriazole, and antifoaming agent, the same procedure was repeated except that sulfate ions mixed as free anions were added in the form of potassium sulfate to adjust the free anion concentration, that is, the sulfate ion concentration to about 800 ppm. Black Ink 6].
[0202]
[Comparative Example 3]
(Preparation of black ink 7)
In Example 3, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, 2-amino-2-ethyl-1,3-propanediol, N-cyclohexyl-2-aminoethane Except for the sulfonic acid, benzotriazole and antifoaming agent, nitrate ions mixed as free anions were added in the form of potassium nitrate to adjust the free anion concentration, that is, the nitrate ion concentration to about 800 ppm. Ink 7].
[0203]
[Comparative Example 4]
(Preparation of yellow ink 8, magenta ink 8, and cyan ink 8)
In Example 4, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, 2-amino-2-ethyl-1,3-propanediol, and N-cyclohexyl-2 of the yellow ink 1 were used. -[Yellow Ink 8] was prepared in the same manner except that aminoethanesulfonic acid, benzotriazole and the antifoaming agent were removed. 2-Methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, 2-amino-2-ethyl-1,3-propanediol, N-cyclohexyl-2-aminoethanesulfone of magenta ink 1 [Magenta Ink 8] was prepared in the same manner except that the acid, benzotriazole and antifoaming agent were removed.
Similarly, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, 2-amino-2-ethyl-1,3-propanediol, and N-cyclohexyl-2-amino of cyan ink 1 [Cyan Ink 8] was prepared in the same manner except that ethanesulfonic acid, benzotriazole and the antifoaming agent were removed.
[0204]
[Comparative Example 5]
(Preparation of yellow ink 9, magenta ink 9, and cyan ink 9)
Yellow ink 9 was prepared in the same manner as in Yellow ink 2 of Example 5, except that 2-methyl-2,4-pentanediol and 2-ethyl-1,3-hexanediol were not used.
Similarly, magenta ink 2 was prepared in the same manner except that 2-methyl-2,4-pentanediol and 2-ethyl-1,3-hexanediol were omitted.
Similarly, in Cyan Ink 3, [Cyan Ink 9] was prepared in the same manner except that 2-methyl-2,4-pentanediol and 2-ethyl-1,3-hexanediol were removed.
[0205]
[Comparative Example 6]
(Preparation of Yellow Ink 10, Magenta Ink 10, and Cyan Ink 10)
[Yellow Ink 10] was prepared in the same manner as in Yellow Ink 3 of Example 6, except that 2-methyl-2,4-pentanediol and 2-ethyl-1,3-hexanediol were omitted.
Similarly, magenta ink 10 was prepared in the same manner as in magenta ink 3, except that 2-methyl-2,4-pentanediol and 2-ethyl-1,3-hexanediol were omitted.
Similarly, in Cyan Ink 3, [Cyan Ink 10] was prepared in the same manner except that 2-methyl-2,4-pentanediol and 2-ethyl-1,3-hexanediol were removed.
[0206]
[Comparative Example 7]
(Preparation of yellow ink 11, magenta ink 11, and cyan ink 11)
[Yellow Ink 11] was prepared in the same manner as in Yellow Ink 4 of Example 7, except that 2-methyl-2,4-pentanediol and 2-ethyl-1,3-hexanediol were omitted.
Similarly, magenta ink 4 was prepared in the same manner as in [magenta ink 11] except that 2-methyl-2,4-pentanediol and 2-ethyl-1,3-hexanediol were omitted.
Similarly, in Cyan Ink 4, [Cyan Ink 11] was prepared in the same manner except that 2-methyl-2,4-pentanediol and 2-ethyl-1,3-hexanediol were removed.
[0207]
[Comparative Example 8]
(Preparation of yellow ink 12, magenta ink 12, and cyan ink 12)
[0208]
[Yellow Ink 12] was prepared in the same manner as in Yellow ink 5 of Example 8, except that 2-methyl-2,4-pentanediol and 2-ethyl-1,3-hexanediol were omitted.
Similarly, magenta ink 12 was prepared in the same manner as in magenta ink 5, except that 2-methyl-2,4-pentanediol and 2-ethyl-1,3-hexanediol were not used.
Similarly, in Cyan Ink 5, [Cyan Ink 12] was prepared in the same manner except that 2-methyl-2,4-pentanediol and 2-ethyl-1,3-hexanediol were removed.
Similarly, black ink 4 was referred to as [black ink 8] except that 2-methyl-2,4-pentanediol and 2-ethyl-1,3-hexanediol were omitted.
[0209]
[Comparative Example 9]
(Preparation of yellow ink 13, magenta ink 13, and cyan ink 13)
[0210]
The same as the yellow ink 6 of Example 6, except that the amount of the yellow dispersion 3 was changed to 4% by weight and 2-methyl-2,4-pentanediol and 2-ethyl-1,3-hexanediol were removed. To [Yellow Ink 13].
Similarly, in the magenta ink 6, the amount of the magenta dispersion 3 was changed to 4% by weight, and 2-methyl-2,4-pentanediol and 2-ethyl-1,3-hexanediol were removed. [Magenta ink 13].
Similarly, in the cyan ink 6, except that the amount of the cyan dispersion liquid 3 was changed to 4% by weight and 2-methyl-2,4-pentanediol and 2-ethyl-1,3-hexanediol were removed. [Cyan ink 13].
[0211]
[Comparative Example 10]
(Preparation of yellow ink 14, magenta ink 14, and cyan ink 14)
In the yellow ink 7 of Example 7, except that the blending amount of the yellow dispersion liquid 4 was set to 1.0% by weight and 2-methyl-2,4-pentanediol and 2-ethyl-1,3-hexanediol were removed. Is [Yellow Ink 14] in the same manner.
Similarly, in magenta ink 7, except that the amount of magenta dispersion liquid 4 was changed to 1.0% by weight and 2-methyl-2,4-pentanediol and 2-ethyl-1,3-hexanediol were removed. To [Magenta Ink 14].
Similarly, in the cyan ink 7, except that the amount of the cyan dispersion liquid 4 was changed to 5% by weight and 2-methyl-2,4-pentanediol and 2-ethyl-1,3-hexanediol were removed. [Cyan ink 14].
[0212]
【Evaluation test】
Next, the following tests were carried out using the inks of Examples 1 to 10 and Comparative Examples 1 to 10 as a four-color ink set.
[0213]
1) Image sharpness
An ink jet printer having a thermal ink jet system having 300 nozzles with a nozzle diameter of 18 μm and a pitch of 600 dpi, and an ink jet printer using a laminated PZT having a nozzle diameter of 28 μm and a nozzle pitch of 200 dpi with a pressure of 200 dpi. Printing is performed with an ink jet print printer having 300 nozzles of each color using an electrostatic actuator to pressurize the liquid chamber flow path, and comprehensive determination of visual bleeding, image bleeding, color tone, and density at the boundary of the two-color overlapping portion is made. did. The color development during OHP projection was also evaluated.
Printing paper is commercially available recycled paper, high-quality paper and bond paper, glossy film with water-soluble resin layer absorbing layer, OHP sheet
[0214]
<Rank in sensory evaluation>
The evaluation was ranked according to the following criteria.
5: No blur at the boundary of the two-color overlapped portion regardless of the paper type, high image density, high sharpness and high color reproducibility
4: Image density is slightly lower in the above
3: Color boundary bleeding is small, but secondary color unevenness etc. can be recognized depending on the paper type.
2: Color boundary blur occurs depending on paper type
1: The image density is low and the sharpness is poor as described above
[0215]
2) Water resistance of images
The image sample was immersed in water at 30 ° C. for 1 minute, and the change in image density before and after the treatment was measured by X-Rite 938, and the water resistance (color resistance%) was determined by the following equation.
Color fastness (%) = [1− (image density after processing / image density before processing)] × 100 10% or less of 5 and 20% or less of 4 and less than 30% 3, 30% or more was 2, and 50% or more was 1.
[0216]
3) Image light fastness
An image sample was subjected to an exposure test using a xenon weatherometer Ci35W (manufactured by Atlas) at a black panel temperature of 63 ° C and a relative humidity of 50% of 0.35 W / m2 using a borosili / borosili filter, and faded after 28 hours. The state was determined by a color difference using X-Rite 938. When ΔE was less than 6 for each color, it was evaluated as ○, when ΔE was less than 15 for each color, as Δ, and when ΔE was more than 6, it was evaluated as ×.
[0219]
4) Dryness of image
The filter paper was pressed against the image after printing under certain conditions, and the time until the ink was not transferred to the filter paper was measured.
If any of the papers dried within 10 seconds, it was judged as ○. Anything higher than that was marked as x.
[0218]
5) Storage stability
Each ink was placed in a polyethylene container and stored at −20 ° C., 5 ° C., 20 ° C., and 70 ° C. for 3 months under the respective conditions, and there was no change in surface tension, viscosity, precipitate precipitate, and particle size after storage. Was examined. No change in physical properties and the like was observed regardless of the conditions of storage.
[0219]
6) Printing pause reliability
Using a printer having a head driven by PZT having a nozzle diameter of 30 μm and 128 nozzles, investigate how much printing can be resumed even after printing is stopped without capping, cleaning, etc. during operation. The results of evaluating the reliability depending on whether the ejection direction is shifted or the weight of the discharged droplet changes are shown in the table.
5: No problem
4: Change in drop weight is small and within the bending limit of jetting direction
3: Small bend
2: Large change in drop weight but no clogging
1: Significant clogging occurred
[0220]
[Table 1]

[0221]
【The invention's effect】
According to the first aspect of the present invention, it is possible to provide an ink formulation having high image quality in an ink containing a specific compound in a specified weight ratio in the ink.
According to the inventions 2 to 5, the concentration of the free monovalent anion present in the ink is regulated to improve the storage stability of the coloring material, to secure the ejection stability after continuous and resting, and The durability of the member that comes into contact with the liquid can be improved.
[0222]
According to the present inventions 6 to 8, it is possible to provide an ink formulation with high image quality by defining the content of the specific compound in the ink.
According to the present inventions 9 to 11, an ink formulation capable of supplying to a head an ink having particularly stable ink physical properties in an ink containing a pigment subjected to a surface treatment as a coloring material and an ink containing an anionic dye. Can be provided.
[0223]
According to the twelfth aspect of the invention, it is possible to provide an ink formulation capable of reducing the bubbles in the ink by adding an antifoaming agent and supplying an ink having stable ink physical properties to the head.
According to the thirteenth aspect of the invention, by showing a particularly preferable aspect of the ink additive, it is possible to provide a pigment ink in which aggregation due to environmental change of the pigment is less likely to occur.
[0224]
According to the fourteenth aspect, it is an object of the present invention to provide a pigment ink having excellent clogging resistance by showing a preferable range of the pigment particle size distribution and capable of maintaining the filter life inside the head for a long period of time.
According to the fifteenth aspect, by using a self-dispersion pigment, it is possible to provide a pigment ink using a pigment dispersion having excellent dispersion stability and excellent ejection characteristics.
[0225]
According to the sixteenth aspect of the invention, it is possible to provide a pigment ink having excellent clogging resistance and exhibiting a long life of a filter or the like inside the head for a long period of time by indicating a preferable range of the particle size distribution of the self-dispersion pigment.
According to the seventeenth aspect, by showing a particularly preferred embodiment of the surface-treated pigment, it is possible to provide a highly reliable pigment ink having good water resistance, bleeding of characters, and little bleeding at a color boundary.
[0226]
According to the eighteenth aspect of the invention, by using a water-soluble dye, it is possible to provide an ink having excellent color developability and balanced water resistance.
According to the nineteenth aspect, by using the colored resin fine particles, it is possible to provide an ink which is excellent in color developability, has high fixability to glossy paper and the like, and has excellent storage stability.
According to the twentieth aspect of the invention, by limiting the range of the particle diameter of the colored fine particles, the clogging resistance is excellent, and the life of the filter and the like inside the head can be maintained for a long time.
[0227]
According to the twenty-first aspect, by adding a specific anionic surfactant, it is possible to provide an ink having excellent image characteristics and corresponding to high-speed printing.
According to the twenty-second aspect of the present invention, it is possible to provide an ink having excellent storage characteristics adjusted to a physical property range that can be preferably used for a remaining amount detection, a charge control type inkjet, and the like. According to the twenty-third aspect of the present invention, it is possible to provide an ink to which a water-soluble organic solvent which is preferably used for adjusting the viscosity of the ink and ensuring moisture retention and which does not cause aggregation of the coloring material or the like is added.
[0228]
According to the twenty-fourth aspect of the present invention, it is possible to improve the wettability to paper and to specify the type of surfactant other than the anionic surfactant suitable for imparting permeability, and to provide an ink with improved suitability for plain paper. Can be.
According to the twenty-fifth aspect of the present invention, it is possible to provide an ink with improved suitability for plain paper to which a hydrophilic solvent for improving wettability to paper and imparting permeability is added.
According to the twenty-sixth aspect of the invention, a printer with high durability can be provided by characterizing an ink pH range appropriate for matching characteristics with members used in the printer.
[0229]
According to the twenty-seventh aspect, a good color image can be formed on plain paper by using the ink.
According to the twenty-eighth aspect of the present invention, a good color image can be formed on plain paper by using the ink cartridge.
According to the twenty-ninth aspect of the present invention, by providing an inkjet device using the ink, a good image can be stably printed on plain paper at high speed.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an example of a head configuration that is a main part of an ink jet recording apparatus using thermal energy.
FIG. 2 is a diagram illustrating an example of an inkjet recording apparatus incorporating a head.
FIG. 3 is a diagram illustrating an example of an ink cartridge that stores ink supplied to a printhead via an ink supply member, for example, a tube.
FIG. 4 is a diagram showing an example in which a recording head and an ink cartridge are integrated.
FIG. 5 is a diagram illustrating an example of a configuration of a recording head that is a main part of the recording apparatus.
FIG. 6 is a sectional view of an ink jet head to which the present invention is applied.
[Explanation of symbols]
1 Inkjet head
2 Silicon substrate
3 Nozzle plate
4. Borosilicate glass substrate
5 Ink chamber
6 Common ink chamber
7 Ink supply path
8 Bottom wall
9 recess
91 Opposing wall
92 Surface of recess
10 segment electrode
11 Ink nozzle
15 Insulation layer
G Distance between electrodes
13 head
14 nozzles
15 Heating element substrate
16 Protective layer
17-1 electrode
17-2 electrode
18 Heating resistor layer
19 Thermal storage layer
20 substrates
21 ink
22 Discharge orifice
23 Meniscus
24 ink droplets
25 Recording material
61 blade
62 cap
63 Ink absorber
64 Discharge recovery section
65 Recording Head
66 carriage
67 Guide shaft
68 motor
69 belt
51 paper feeder,
52 Paper feed roller
53 Paper ejection roller
40 ink storage section
42 stopper
44 Ink absorber
70 Recording unit
72 Atmospheric communication port
80 Ink channel
81 Orifice plate
82 diaphragm
83 Piezoelectric element
84 substrate
85 Discharge port

Claims (29)

Recording containing at least a coloring material, an organic solvent for dissolving or dispersing the same, water, an anion or a nonionic surfactant, a coloring material concentration of 10 wt% or more, and an ink viscosity of 8 mPa · s (25 ° C.) or more A recording liquid comprising 2-methyl-2,4-pentanediol and 2-ethyl-1,3-hexanediol in a weight ratio of 20/1 to 15/10. 2. The recording liquid according to claim 1, wherein the concentration of the free monovalent anion present in the recording liquid is 500 ppm or less. 2. The recording liquid according to claim 1, wherein the concentration of the free monovalent anion present in the recording liquid is 300 ppm or less. 2. The recording liquid according to claim 1, wherein the concentration of the free monovalent anion present in the recording liquid is 100 ppm or less. The recording liquid according to any one of claims 1 to 4, wherein the free monovalent anion present in the recording liquid is at least one of a halogen ion, a nitrate ion, and an organic acid ion. 2. The recording liquid according to claim 1, comprising 15 to 40% by weight of 2-methyl-2,4-pentanediol. 2. The recording liquid according to claim 1, comprising 2 to 10% by weight of 2-ethyl-1,3-hexanediol. The recording liquid according to any one of claims 1 to 7, further comprising at least one of 2-pyrrolidone, N-methyl-2-pyrrolidone, and N-hydroxyethyl-2-pyrrolidone. The recording liquid according to any one of claims 1 to 8, comprising 2-amino-2-ethyl-1,3-propanediol. The recording liquid according to any one of claims 1 to 9, further comprising N-cyclohexyl-2-aminoethanesulfonic acid. The recording liquid according to any one of claims 1 to 10, further comprising benzotriazole. The recording liquid according to claim 1, further comprising a silicone-based antifoaming agent. The recording liquid according to any one of claims 1 to 12, wherein the coloring material is a pigment, dispersed in water by a dispersant, and a carboxyl group is bonded to the dispersant. 14. The recording liquid according to claim 13, wherein the pigment has a particle size of 10 nm to 300 nm. The recording liquid according to claim 1, wherein the coloring material is a self-dispersion pigment having an anionic group on a surface. The recording liquid according to claim 15, wherein the self-dispersion pigment has a particle size of 10 nm to 300 nm. 17. The recording liquid according to claim 15, wherein at least one of the anionic groups is a carboxylic acid group. 13. The recording liquid according to claim 1, wherein the coloring material is a dye having at least one carboxylic acid group and / or sulfonic acid group. The recording liquid according to claim 1, wherein the coloring material is fine particles colored with a dye or a pigment. 20. The recording liquid according to claim 19, wherein the colored fine particles have a particle size of 10 nm to 300 nm. 21. The recording liquid according to claim 1, wherein the surfactant having an anionic group is polyoxyethylene alkyl ether acetate and / or dialkyl sulfosuccinate. The recording liquid according to any one of claims 1 to 21, wherein the conductivity is 1 mS / cm or more. The organic solvent is glycerin, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 1,5 -Pentanediol, tetraethylene glycol, 1,6-hexanediol, polyethylene glycol, 1,2,4-butanetriol, 1,2,6-hexanetriol, thiodiglycol, 1,3-dimethyl-2-imidazolidy The recording liquid according to any one of claims 1 to 22, wherein the recording liquid is at least one water-soluble organic solvent selected from non-soluble solvents. Further, it contains at least one surfactant selected from acetylene glycol-based surfactant, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyethylene-polypropylene copolymer, and fluorine-based surfactant. The recording liquid according to any one of claims 1 to 23, wherein 25. The recording liquid according to claim 1, further comprising a diol having 6 or more carbon atoms and an alkyl ether. The aqueous ink according to any one of claims 1 to 25, wherein the pH is adjusted to 6 or more and 11 or less. 27. The recording liquid according to any one of claims 1 to 26, which is jetted as fine droplets by thermal energy or mechanical energy, and has a Steckigt sizing degree of 3 seconds or more according to JIS P-8122 test method. A recording method, wherein an image is formed by adhering to an agent. 27. A recording liquid cartridge provided with a recording liquid storage section containing a recording liquid, wherein the recording liquid is the recording liquid according to claim 1. A recording liquid storage unit or a recording liquid cartridge containing a recording liquid, an ink jet recording apparatus including a head unit or a recording unit for dropping and discharging the recording liquid by the action of thermal energy, wherein the recording liquid is used. 26. An ink jet recording apparatus comprising the recording liquid according to any one of items 26 to 26.

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