JP3588058B2 - Ink for inkjet printer - Google Patents

Description

【００８９】
実施例１
３００ｃｃのガラス製コンテナを付けたダイノミルＫＤＬ型に、
合成例１のシリコーン系グラフトポリマー １３０．０部
顔料としてＦａｓｔｏｇｅｎ Ｂｌｕｒｅ ＴＧＲ
（大日本インキ化学工業社製の銅フタロシアニンブルー顔料） ５７．０部
フタロシアニン顔料誘導体としてソルスパース５０００ ３．０部
メチルエチルケトン ３７．０部
ＫＦ−９６Ｌ−２ ３７．０部
３ｍｍφジルコニアビーズ ２５０ｃｃ
を仕込み、５℃の水で冷却し、回転数１０００ｒｐｍで２時間分散し、分散スラ
リーを得た。その後、
上記分散スラリー １３．２部
メチルエチルケトン ３０．９部
ＫＦ−９６Ｌ−２ ３０．９部
を混合し、混合液とした。
【００９０】
次に、シリコーン溶媒としてＫＦ−９６Ｌ−２を７５部秤取し、３００ｃｃナスフラスコに入れ、マグネチックスターラーで攪拌した。攪拌しながら、前記混合液をゆっくりと滴下し、粒状物質表面にシリコーン系グラフトポリマーを析出させた。
【００９１】
滴下後、メチルエチルケトンを減圧蒸留にて脱溶媒し、さらに、１２０℃で５時間架橋反応させ、顔料濃度４．７５％の分散液組成物を得た。得られた分散液組成物は、分散粒径が０．１２５μｍ（コールター社製のレーザードップラー方式の粒度分布計Ｎ４ ＰＬＵＳで測定）、また、この分散液組成物をＫＦ−９６Ｌ−１を使用して不揮発分濃度を５％に調整し、３３５００Ｇの遠心力を５時間かけ上澄みの不揮発分から遠心沈降による樹脂吸着量を測定したところ、粒状物質１００部に対して８０．５部のシリコーン系グラフトポリマーが吸着されていた。また、上記分散液組成物中の有機顔料のポリマーの吸着前と吸着後の透過型電子顕微鏡写真をそれぞれ図１及び図２に示す。図２に示されるように、ポリマーを吸着させた有機顔料には、図１における有機顔料単独の場合には見られないポリマーが明らかに顔料表面に吸着していることが確認できる。
【００９２】
さらにＫＦ‐９６−１０を１０部、上記分散液組成物を顔料換算で３部となる量（６３．１部）にＫＦ−９６Ｌ−２を加え全量１００部とし、口径１μｍのフィルターでろ過し、顔料濃度３％の油性インクジェットプリンター用インクを調製した。
【００９３】
このインクは、下記の表３に示すとおり、粒径や粘度はともに小さく、保存試験後の変化もなく沈降も見られなかった。また印字試験においても印字安定性や再吐出性にも非常に優れた特性を示した。
【００９４】
比較例１
５００ｃｃのプラスチック製ビンに、
顔料としてＦａｓｔｏｇｅｎ Ｂｌｕｅ ＴＧＲ
（大日本インキ化学工業社製の銅フタロシアニンブルー顔料） ３．０部
ＭＧＳ−Ｆ７５（日光ケミカルズ社製ノニオン界面活性剤） ０．５部
タマノル１３５（荒川化学社製ロジン系樹脂） ３．０部
テクノケア ＦＲＶ（東芝シリコーン社製シリコーンオイル） ２９．５部
テクノケア ＦＲＶ（東芝シリコーン社製シリコーンオイル） ５．０部
ＫＦ−９６Ｌ−２（信越化学社製ジメチルシロキサン） ３７．０部
オレイルアルコール ２２．０部
３ｍｍφジルコニアビーズ ３００部
を計り取り、ペイントシェーカー（エイシン社製）で２時間分散し、油性インクジェットインクを作製した。
【００９５】
このインクは、下記の表３に示すとおり、実施例１に比べ粒径や粘度が大きく、保存試験後粒径や粘度が大きくなり沈降も見られ印字安定性、再分散性に劣っていた。
【００９６】
実施例２
実施例１で使用したＦａｓｔｏｇｅｎ Ｂｌｕｅ ＴＧＲ顔料とＳｏｌｓｐｅｒｓｅ５０００のかわりにＣｉｎｑｕａｓｉａ Ｍａｇｅｎｔａ ＲＴ−３５５−Ｄ（チバスペシャリティーケミカル社製）を使用した以外は、実施例１と同様にして、下記の表２に示す分散液組成物を調製した。
【００９７】
さらに、実施例１と同様にして顔料濃度３％の油性インクジェットプリンター用インクを調整した。このインクは、表３に示すとおり、粒径や粘度はともに小さく、保存試験後の変化もなく沈降も見られなかった。また印字試験においても印字安定性や再吐出性にも非常に優れた特性を示した。
【００９８】
比較例２
実施例２で使用した合成例１のシリコーン系グラフトポリマー１３０．０部のかわりに合成例５のポリマー１２６．８部とメチルエチルケトン３．２部を使用した以外は、実施例１と同様にして、下記の表２に示す分散液組成物を調製した。
【００９９】
さらに、実施例２と同様にして顔料濃度３％の油性インクジェットプリンタ用インクを調整した。このインクは、下記の表３に示すとおり、実施例２に比べ粒径が大きく、保存試験後沈降が見られた。また印字試験においても吐出不良を起こし印字安定性や再吐出性にも劣っていた。
【０１００】
実施例３
実施例１で使用したＦａｓｔｏｇｅｎ Ｂｌｕｅ ＴＧＲ顔料とＳｏｌｓｐｅｒｓｅ５０００のかわりにＹｅｌｌｏｗ ＨＧ（クラリアント社製）を使用した以外は、実施例１と同様にして下記の表２に示す分散液組成物を調製した。
【０１０１】
さらに、実施例１と同様にして顔料濃度３％の油性インクジェットプリンタ用インクを調整した。このインクは、下記の表３に示すとおり、粒径や粘度はともに小さく、保存試験後の変化もなく沈降も見られなかった。また印字試験においても印字安定性や再吐出性にも非常に優れた特性を示した。
【０１０２】
実施例４
実施例１で使用したＦａｓｔｏｇｅｎ Ｂｌｕｅ ＴＧＲ顔料のかわりにＰｒｉｎｔｅｘ ８５（デグサ社製のカーボンブラック顔料）を使用した以外は、実施例１と同様にして下記の表２に示す分散液組成物を調製した。
【０１０３】
さらに、実施例１と同様にして顔料濃度３％の油性インクジェットプリンタ用インクを調製した。このインクは、下記の表３に示すとおり、粒径や粘度はともに小さく、保存試験後の変化もなく沈降も見られなかった。また印字試験においても印字安定性や再吐出性にも非常に優れた特性を示した。
【０１０４】
比較例３
５００ｃｃのプラスチック製ビンに、
顔料としてＰｒｉｎｔｅｘ ８５
（デグサ社製のカーボンブラック顔料） １０．０部
ノニオンＯＰ８０Ｒ（日本油脂社製ノニオン界面活性剤） ２．５部
タマノル５１０（荒川化学社製フェノール系樹脂） １５．０部
アイソパーＬオレイルアルコール ７５．０部
３ｍｍφジルコニアビーズ ３００部
を計り取り、ペイントシェーカー（エイシン社製）で２時間分散し、油性インクジェットインクを作製した。
【０１０５】
このインクは、下記の表３に示すとおり、上記実施例に比べ粒径や粘度が大きく、沈降が見られ印字安定性に劣っていた。
【０１０６】
実施例５
実施例１で使用した合成例１のシリコーン系グラフトポリマー１３０．０部とメチルエチルケトン３７部のかわりに合成例２のポリマー１３１．６部とメチルエチルケトン３５．４部を使用した以外は、実施例１と同様にして、下記の表２に示す分散液組成物を調製した。
【０１０７】
さらに、実施例１と同様にして顔料濃度１０％の油性インクジェットプリンタ用インクを調製した。このインクは、下記の表３に示すとおり、粒径や粘度はともに小さく、保存試験後の変化もなく沈降も見られなかった。また印字試験においても印字安定性や再吐出性にも非常に優れた特性を示した。
【０１０８】
実施例６
３００ｃｃのガラス製コンテナを付けたダイノミルＫＤＬ型に、
合成例３のシリコーン系グラフトポリマー １２７．７部
顔料としてＦａｓｔｏｇｅｎ Ｂｌｕｒｅ ＴＧＲ
（大日本インキ化学工業社製の銅フタロシアニンブルー顔料） ５７．０部
フタロシアニン顔料誘導体としてソルスパース５０００ ３．０部
メチルエチルケトン ３９．３部
ＫＦ−９６Ｌ−２ ３７．０部
３ｍｍφジルコニアビーズ ２５０ｃｃ
を仕込み、５℃の水で冷却し、回転数１０００ｒｐｍで２時間分散し、分散スラ
リーを得た。その後、
上記分散スラリー １３．２部
メチルエチルケトン ３０．９部
ＫＦ−９６Ｌ−２ ３０．９部
を混合し、混合液とした。
【０１０９】
次に、シリコーン溶媒としてＫＦ−９６Ｌ−２を７５部秤取し、３００ｃｃナスフラスコに入れ、マグネチックスターラーで攪拌した。攪拌しながら、前記混合液をゆっくりと滴下し、粒状物質表面にシリコーン系グラフトポリマーを析出させた。
【０１１０】
滴下後、メチルエチルケトンを減圧蒸留にて脱溶媒し、顔料濃度４．８５％の分散液組成物を得た。得られた分散液組成物は、分散粒径が０．１７４μｍ（コールター社製のレーザードップラー方式の粒度分布計Ｎ４ ＰＬＵＳで測定）、また、この分散液組成物をＫＦ−９６Ｌ−１を使用して不揮発分濃度を５％に調整し、３３５００Ｇの遠心力を５時間かけ上澄みの不揮発分から遠心沈降による樹脂吸着量を測定したところ、粒状物質１００部に対して８３部のシリコーン系グラフトポリマーが吸着されていた。
【０１１１】
さらにＫＦ‐９６−１０を１０部と上記分散液組成物を顔料換算で３部となる量（６１．９部）にＫＦ−９６Ｌ−２を加え全量１００部とし、口径１μｍのフィルターでろ過し、顔料濃度３％の油性インクジェットプリンタ用インクを調製した。
【０１１２】
このインクは、下記の表３に示すとおり、粒径や粘度はともに小さく、保存試験後の変化もなく沈降も見られなかった。また印字試験においても印字安定性や再吐出性にも非常に優れた特性を示した。
【０１１３】
実施例７
実施例５で使用した合成例２のシリコーン系グラフトポリマー１２７．７部とメチルエチルケトン３９．３部のかわりに合成例４のポリマー１２３．５部とメチルエチルケトン４３．５部を使用した以外は、実施例１と同様にして、下記の表２に示す分散液組成物を調製した。
【０１１４】
さらに、実施例５と同様にして顔料濃度３％の油性インクジェットプリンタ用インクを調製した。このインクは、下記の表３に示すとおり、粒径や粘度はともに小さく、保存試験後の変化もなく沈降も見られなかった。また印字試験においても印字安定性や再吐出性にも非常に優れた特性を示した。
【０１１５】
ここで顔料濃度は分散液組成物を約２ｇアルミシャーレに計り取り、２２０℃のオーブンで６０分乾燥して測定した。
【０１１６】
下記の表２における、分散粒径はコールター社製のレーザードップラー方式の粒度分布計Ｎ４ ＰＬＵＳで分散平均粒径を測定した。また、吸着量は分散液組成物をＫＦ−９６Ｌ−１（信越化学社製）を使用して不揮発分濃度を５％に調整し、３３５００Ｇの遠心力を５時間かけ上澄みの不揮発分から遠心沈降による顔料１００に対する樹脂吸着量を測定した。
【０１１７】
【表２】
表２

【０１１８】
次に油性インクジェットプリンタ用インクの特性を調べた。ここで粒径はコールター社製のレーザードップラー方式の粒度分布計Ｎ４ ＰＬＵＳで測定した。また、粘度は東機産業社製Ｒ型粘度計で回転数１００ｒｐｍで測定した。なお、１００ｒｐｍで測定できないものは、回転数を小さくし測定した。保存試験は６０ｃｃガラス製容器にインクを４０ｇ計り取り密閉して、６０℃の恒温槽に２週間放置した。その結果、沈降物が見られないものを○、沈降物が見られるものを×で表した。印字試験はエプソン社製Ｃ−５２０インクカートリッジに詰めてＣ−５２０インクジェットプリンターでＡ４用紙に印字し、印字安定性を電子工業協会のインジパターンを連続印字し、連続１０００枚以上安定して印字できたものを○、クリーニングを必要としたが連続１０００枚以上印字できたものを△、目詰まりを起こし印字できなくなったものを×で表した。再吐出性はインクをＣ−５２０インクジェットプリンタにセットして室温下１ヶ月放置した後、再度印字試験を行い、クリーニング１回内で安定した印字を示すものを○、クリーニング３回内で安定した印字を示すものを△、安定した印字を示さないものを×で表した。結果を表３に示す。
【０１１９】
【表３】
表３

【０１２０】
【発明の効果】
以上説明したように、本発明の油性インクジェットプリンター用インクは、顔料の沈降や保存安定性と言った分散安定性を高めるとともに、印字安定性も改良された。また、顔料と有機溶媒の利用により耐水性や耐光性とといった印字品質の向上もでき、さらに、安全性の高い高沸点のシリコーン系有機溶媒を使用することにより、インクの安全性も高めることができた。
【図面の簡単な説明】
【図１】実施例１における分散液組成物中の有機顔料のポリマー吸着前の電子顕微鏡写真である。
【図２】実施例１における分散液組成物中の有機顔料のポリマー吸着後の電子顕微鏡写真である。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ink for an inkjet printer in which a pigment is dispersed in an organic solvent. More specifically, the present invention relates to an ink for an inkjet printer having improved dispersion stability of a pigment.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in the field of ink for inkjet printers in which a pigment is dispersed in an organic solvent, a pigment is dispersed using a dispersant, and various improvements have been made in printing characteristics and storage stability. For example, JP-A-04-161467 and JP-A-04-248879 describe an ink containing a pigment, a resin, and a dispersant in a silicone-based organic solvent, and exhibit excellent print quality by exhibiting immediate drying. It is shown to gain.
[0003]
Further, Japanese Patent Application Laid-Open No. 05-25417 discloses that an inkjet ink in which colored resin particles are dispersed in a non-polar insulating organic solvent has no bleeding on recording paper, has excellent print drying properties, and has no nozzle clogging. It is described as having excellent scratch resistance.
[0004]
However, when the above-mentioned silicone-based organic solvent is used, there is no suitable dispersant for finely dispersing the pigment, and the dispersed particle size of the pigment is as large as 0.5 to 5 μm. The quality will be reduced. Similarly, when the colored resin particles are used, since the colored resin particles are pulverized and dispersed, the dispersed particle diameter is largely settled, and the printing quality is reduced. In addition, since a hydrocarbon solvent is used as the organic solvent, there is a concern about safety for the human body.
[0005]
Furthermore, pigment type aqueous inkjet inks that are generally sold are not satisfactory in water resistance.
[0006]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to disperse a pigment stably in an organic solvent in fine particles, to prevent sedimentation even when stored for a long time, to excel in printing stability, and to improve the water resistance and light fastness of the printing quality. An object of the present invention is to provide an ink jet printer ink in which a pigment is dispersed in a solvent and which is excellent also in terms of safety to the human body.
[0007]
[Means for Solving the Problems]
The object is to provide an inkjet printer ink containing a pigment and an organic solvent, in which a silicone-based graft polymer is blended, and the silicone-based graft polymer is adsorbed on at least a part of the outer surface of the pigment, and the organic solvent is removed. The problem is solved by dispersing the particles into particles having a particle diameter in the range of 0.01 μm to 0.3 μm.
[0008]
According to the study of the present inventors, by dispersing the silicone-based graft polymer in the form of particles having a particle size of 0.01 μm to 0.3 μm in an organic solvent while adsorbing the silicone-based graft polymer on the surface of the pigment, It has been found that the steric repulsion can be enhanced to prevent the sedimentation of the pigment, the dispersion stability can be improved and the printing stability can be improved, and further, the printing quality can be improved by using the pigment and the organic solvent. Further, they have found that the use of a highly safe silicone-based organic solvent can enhance the safety of the ink.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
The ink for an inkjet printer of the present invention basically contains a pigment, an organic solvent, and a silicone-based graft polymer as essential components.
[0010]
The silicone-based graft polymer is a graft polymer having silicone, and is adsorbed on the surface of the pigment, and the pigment is dispersed in an organic solvent into particles of 0.01 μm to 0.3 μm. Although not particularly limited, those which self-disperse with a particle size of 0.01 μm to 0.3 μm, preferably 0.015 to 0.2 μm are more preferable. A more preferred particle size is from 0.015 μm to 0.1 μm.
[0011]
As used herein, the term "self-dispersing" means that the polymer is dispersed only in the graft polymer without the use of protective colloids or surfactants, which do not dissolve in organic solvents and protect special dispersion. Means For example, there is a phenomenon in which, when the solution is dissolved in an organic solvent that dissolves the graft polymer, and the solution is mixed with an organic solvent that does not dissolve the graft polymer, the mixture is not formed into a large lump but is dispersed in a granular form. The particle size of the graft polymer can be measured with a general known particle size distribution measuring device, for example, a laser type or light scattering type particle size distribution meter, a centrifugal sedimentation type particle size distribution meter, or the like.
[0012]
The particle diameter of the pigment to which the silicone-based graft polymer is adsorbed in the ink for an ink jet printer of the present invention is preferably 0.01 to 0.3 μm, and more preferably 0.01 to 0.2 μm, in consideration of a decrease in print quality. More preferred. Further preferred ranges are 0.01 to 0.1 μm, 0.05 to 0.25 μm, 0.1 to 0.3 μm or 0.08 to 0.16 μm.
[0013]
The particle size distribution of the primary particle diameter of the pigment in the ink of the present invention is preferably in the range of 0.01 μm to 0.29 μm, and more preferably in the range of 0.01 μm to 0.2 μm from the viewpoint of sedimentation of the pigment. The particle size distribution of the pigment may be, for example, a method of dry-grinding the coarse pigment with a ball mill or the like together with a grinding medium such as a ball, a method of grinding the coarse pigment in a kneader with ethylene glycol and a salt, and a method of grinding the coarse pigment in a solvent in a ball. By a method of wet grinding with a grinding medium, a method of dissolving a crude pigment in a specific solvent and then depositing (for example, a method of dissolving in sulfuric acid, adding water or adding to water to precipitate), and the like. It can be controlled within the range of ０．２0.29 μm.
[0014]
The pigment to which the silicone-based graft polymer is adsorbed in the ink of the present invention preferably has a charge from the viewpoint of dispersion stability. For example, as the charge of the pigment, the absolute value of the ζ potential is preferably from 10 to 300 mV, more preferably from 15 to 200 mV.
[0015]
Pigments that can be used in the ink jet printer ink of the present invention include, for example, inorganic pigments, organic pigments, and dyes that are insoluble in solvents. These pigments can be used alone or in combination of two or more.
[0016]
Examples of the inorganic pigment include carbon black, titanium oxide, zinc oxide, zinc oxide, tripon, iron oxide, aluminum oxide, silicon dioxide, kaolinite, montmorillonite, talc, barium sulfate, calcium carbonate, silica, alumina, cadmium red, Vengara, molybdenum red, chrome vermillion, molybdate orange, graphite, chrome yellow, cadmium yellow, yellow iron oxide, titanium yellow, chromium oxide, pyridian, cobalt green, titanium cobalt green, cobalt chrome green, ultramarine, ultramarine blue , Navy blue, cobalt blue, cerulean blue, manganese violet, cobalt violet, mica and the like. Carbon black is particularly preferred.
[0017]
Organic pigments include C.I. I. Quinacridone pigments such as CI Pigment Red 122, Red 202, Red 207, Red 209, and Violet 19; I. Quinacridone quinone pigments such as CI Pigment Orange 48 and Orange 49; I. Dioxazine pigments such as CI Pigment Violet 23 and Violet 37; I. Pigment Blue 15, Blue 15: 1, Blue 15: 2, Blue 15: 3, Blue 15: 4, Blue 15: 6, Blue 16, Blue 68, Green 7, Green 36, etc. Phthalocyanine pigments; C.I. I. Anthrapyrimidine pigments such as CI Pigment Yellow 108; I. Pigments such as CI Pigment Orange 77 and Red 168; I. Pigment Blue 60 and the like; C.I. I. Flavanthrone pigments such as CI Pigment Yellow 24; I. Anthraquinone pigments such as CI Pigment Yellow 196 and Red 177; I. Perylene pigments such as CI Pigment Red 123, Red 149, Red 178, Red 179, Red 190, and Red 224; I. Perinone pigments such as CI Pigment Yellow 196 and Orange 43; I. Quinophthalone pigments such as CI Pigment Yellow 138; I. Diketopyrrolopyrrole-based pigments such as CI Pigment Orange 71, Orange 73, Red 254, Red 255, Red 264, and Red 272; I. Thioindigo pigments such as CI Pigment Red 88, Red 181 and Brown 27; I. Isoindoline pigments such as CI Pigment Yellow 139, Yellow 185, Orange 69, and Red 260; I. Isoindolinone-based pigments such as CI Pigment Yellow 109, Yellow 110, and Yellow 173; I. Azomethine pigments such as CI Pigment Yellow 101, Yellow 129 and Orange 65; I. Pigment Yellow 151, Yellow 154, Yellow 175, Yellow 180, Yellow 181, Orange 36, Red 175, Red 176, Red 185, and other benzimidazolone-based pigments; I. Pigment Yellow 1, Yellow 65, Yellow 73, Yellow 74, Yellow 116, Red 3, Red 48: 1, Red 48: 2, Red 48: 3, Red 53: 1, Red Monoazo pigments such as C.57: 1, Red 115; C.I. I. Disazo pigments such as CI Pigment Yellow 12, Yellow 13, Yellow 17, Yellow 81, Yellow 81, Yellow 83, and Orange 16; I. Pigment Yellow 93, Yellow 95, Yellow 128, Red 144, Red 144, Red 166, Red 220, Red 221 and the like. The pigment may be a powdery, granular, or massive dry pigment, or may be a wet cake or a slurry.
[0018]
As the dye which does not dissolve in the solvent, an azo type, anthraquinone type, indigo type, phthalocyanine type, carbonyl type, quinone imine type, methine type, quinoline type and nitro type are preferable, and among these, disperse dyes are particularly preferable.
[0019]
In the ink for an inkjet printer of the present invention, it is particularly preferable to use an organic pigment and / or carbon black as a pigment.
[0020]
In the ink for an inkjet printer of the present invention, the amount of the silicone-based graft polymer relative to the pigment (for example, organic pigment and / or carbon black) is in the range of 5 to 3000 parts by weight based on 100 parts by weight of the pigment. It is preferable that Further, it is more preferable that the amount of the silicone-based graft polymer adsorbed on the pigment is in the range of 20 to 1,000 parts by weight based on 100 parts by weight of the pigment. When the amount of the silicone-based graft polymer is 5 parts by weight or more, the dispersion stability is good, and when the amount is 3000 parts by weight or less, the content of the pigment in the dispersion composition does not decrease. A sufficient pigment concentration can be obtained. In the ink for an inkjet printer of the present invention, a more preferable range of the amount of the silicone-based graft polymer with respect to the pigment is in the range of 30 to 1,000 parts by weight based on 100 parts by weight of the pigment.
[0021]
Although the exact mechanism of adsorption of the silicone-based graft polymer to the pigment (eg, organic pigment and / or carbon black) is not clear, chemical bonding (eg, basic sites on the pigment surface due to electron deflection and silicone-based graft polymer) Acid-base bonds, such as tertiary amino groups introduced on the pigment surface and carboxyl groups introduced into the silicone-based graft polymer, to form a divalent or higher valent metal ion and a silicone-based graft polymer. Ionic bond by salt, covalent bond to polymerize based on active group on pigment surface, etc.), physical adsorption (for example, adsorption by cohesive force in which silicone-based graft polymer becomes insoluble in solvent and aggregates) Dispersion by mechanical adsorption, etc.) or physicochemical adsorption (for example, Disperse the cone-based graft polymer and the pigment, and react the active group on the pigment surface with the silicone-based graft polymer while adsorbing the silicone-based graft polymer on the surface of the pigment. It is considered that the silicone-based graft polymer is adsorbed on the pigment surface.
[0022]
The method of measuring the amount of the silicone-based graft polymer adsorbed on the pigment can be determined by a known and commonly used method. For example, the concentration can be measured indirectly by adjusting the concentration of the nonvolatile components in the ink to 5%, centrifuging the ink until the supernatant liquid becomes transparent, and measuring the concentration of the silicone-based graft polymer in the supernatant liquid.
[0023]
The organic solvent which can be used in the ink for an ink jet printer of the present invention has a small polarity,⁹Those having an electrical resistivity of Ω · cm or more are preferable. Generally, the upper limit of electric resistivity is 10¹⁸It is about Ω · cm. Suitable organic solvents for this purpose include, for example, aliphatic hydrocarbon solvents such as hexane and mineral spirit; silicone organic solvents such as dialkylpolysiloxane and cyclic polydialkylsiloxane; olive oil, safflower oil, sunflower Vegetable oils such as oil, soybean oil and linseed oil; aromatic hydrocarbon solvents such as benzene, toluene and xylene; ester solvents such as butyl acetate; alcohol solvents such as methanol and butanol; methyl ethyl ketone, isobutyl Ketone solvents such as methyl ketone; aprotic polar solvents such as dimethylformamide, dimethylsulfoxide, N-methylpyrrolidone, pyridine and the like; These solvents can be used alone or in combination of two or more. Among these solvents, in view of affecting the human body, silicone-based organic solvents are preferable, and among them, methylpolysiloxane and cyclic methylpolysiloxane are more preferable. Further, in consideration of safety such as ignition, a silicone organic solvent having a boiling point of 200 ° C. or more is preferable.
[0024]
The proportion of the organic solvent in the ink for an inkjet printer of the present invention is preferably in the range of 50 to 10000 parts by weight, more preferably 100 to 3000 parts by weight, based on 100 parts by weight of the pigment. When the amount of the organic solvent is less than 50 parts by weight with respect to 100 parts by weight of the pigment, the viscosity becomes too high, so that it is not preferable to perform printing. On the other hand, if the amount of the organic solvent exceeds 10,000 parts by weight with respect to 100 parts by weight of the pigment, it is not preferable because the printed matter becomes too light in color.
[0025]
The silicone-based graft polymer preferably has a polar group in order to finely disperse the pigment and to improve the dispersion stability of the pigment. Examples of the polar group suitable for such a purpose include, but are not particularly limited to, a basic group, an acidic group, and a hydroxyl group.In particular, for finely dispersing the pigment, and for causing a crosslinking reaction, an acidic group is used. Hydroxyl groups are preferred. Although it does not specifically limit as a basic group, A primary, secondary, tertiary, quaternary amino group, etc. are mentioned. Examples of the acidic group include, but are not particularly limited to, a carboxyl group, a sulfonic acid group, a phosphonic acid group, and the like. Particularly, the acid strength is low due to the difficulty in causing aggregation of the dispersion composition and the reaction rate of the crosslinking reaction. Carboxyl groups are more preferred.
[0026]
The acid value of the silicone-based graft polymer is preferably in the range of 5 to 100 KOHmg / g. When the acid value is 5 KOHmg / g or more, the affinity for the pigment is increased, whereby a fine ink for an ink jet printer can be obtained, and the dispersion stability is improved. Further, if the content is less than 100 KOHmg / g, the acid strength of the silicone-based graft polymer is suppressed from becoming strong, self-dispersion is easily caused, gelation during synthesis is prevented, and synthesis is facilitated.
[0027]
The hydroxyl value of the silicone-based graft polymer is preferably in the range of 5 to 100 KOHmg / g. When the hydroxyl value is 5 KOHmg / g or more, the affinity with the pigment is increased, and a fine ink for an inkjet printer can be obtained, and the dispersion stability is improved. Further, when the amount is not more than 100 KOHmg / g, the acid strength of the silicone-based graft polymer is suppressed from being increased, self-dispersion is easily caused, gelation during synthesis is prevented, and synthesis is facilitated.
[0028]
The amine value of the silicone-based graft polymer is preferably in the range of 5 to 100 KOHmg / g. When the amine value is 5 KOHmg / g or more, the affinity with the pigment is increased, and a fine ink for an ink jet printer can be obtained, and the dispersion stability is improved. Further, when the content is 100 KOHmg / g or less, the acid strength of the silicone-based graft polymer is suppressed from becoming strong, self-dispersion is easily caused, gelation during synthesis is prevented, and synthesis is facilitated.
[0029]
The number average molecular weight of the silicone-based graft polymer is preferably in the range of 2,000 to 50,000. When the number average molecular weight is 2000 or more, the pigment can be finely dispersed and sedimentation of the pigment can be prevented. When the molecular weight is 50,000 or less, the compound is easily dissolved in a solvent, and the viscosity of the ink for an ink jet printer can be prevented from becoming too high. A more preferred range is 3,000 to 30,000.
[0030]
Preferred examples of the silicone-based graft polymer include acrylic, polyester, polyurethane, epoxy, and amino polymer compounds. These polymer compounds can be used alone or in combination of two or more. Among these types, an acrylic polymer compound is more preferable because of ease of synthesis and grafting and ease of introduction of a polar group.
[0031]
Further, in consideration of the easiness of self-dispersion in an organic solvent, a grafted acrylic polymer compound is particularly preferable. This is because the portion adsorbed on the pigment and the portion having an affinity for the organic solvent are branched on the branch, so that the pigment is easily self-dispersed. That is, since the terminal of the graft trunk does not solvate, self-dispersion becomes easy. Further, an amphoteric polymer compound having both an acidic group and a basic group is also preferable.
[0032]
The grafted acrylic polymer compound preferably has a graft portion having a molecular weight in the range of 500 to 10000, more preferably 1000 to 8000.
[0033]
As the graft portion, silicone is preferable because of its good affinity for a solvent.
[0034]
The method for producing a silicone-based graft polymer includes those obtained by reacting a monomer having a polar group, a macromonomer, and a monomer having a silicone in a non-reactive solvent in the presence or absence of a catalyst. Among them, those obtained by polymerizing a monomer having a polar group and a silicone-based macromonomer as essential components are preferable. Further, a method of synthesizing an acrylic polymer having a reactive group and then reacting with a reactive silicone to graft the acrylic polymer is also preferable. The silicone-based graft polymer is preferably one that does not become a lump even when polymerized, and dissolves or disperses in a fine state, and particularly preferably has a particle size of 0.01 μm to 0.3 μm.
[0035]
Among the polar group-containing acrylic monomers used in the present invention, preferred monomers having an acidic group as a polar group include acrylic acid, methacrylic acid, crotonic acid, ethacrylic acid, propylacrylic acid, isopropylacrylic acid, and itaconic acid. , Monomers having a carboxyl group such as fumaric acid, acroyloxyethyl phthalate, and acroyloxysuccinate; sulfonic acid groups such as ethyl acrylate-2-ethyl methacrylate 2-ethyl sulfonate and butylacrylamidosulfonic acid; Monomers having a phosphonic acid group such as 2-ethyl methacrylate, 2-ethyl phosphonate and 2-ethyl phosphonate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl acrylate, methacrylate Monomers mentioned with such hydroxyl Le hydroxypropyl, and more preferably monomers having inter alia carboxyl group or a hydroxyl group.
[0036]
Examples of the monomer having a basic group include monomers having a primary amino group such as acrylamide, aminoethyl acrylate, aminopropyl acrylate, methacrylamide, aminoethyl methacrylate, and aminopropyl methacrylate; Methylaminoethyl acrylate, methylaminopropyl acrylate, ethylaminoethyl acrylate, ethylaminopropyl acrylate, methylaminoethyl methacrylate, methylaminopropyl methacrylate, ethylaminoethyl methacrylate, ethylaminopropyl methacrylate, etc. Monomers having a secondary amino group, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, dimethylaminopropyl acrylate, diethylaminopropyl acrylate, dimethyl methacrylate Monoethyl, diethylaminoethyl methacrylate, dimethylaminopropyl methacrylate, diethylaminopropyl methacrylate, etc., monomers having a tertiary amino group, dimethylaminoethyl methyl chloride acrylate, dimethylaminoethyl methyl methacrylate, acrylic acid Monomers having a quaternary amino group such as dimethylaminoethylbenzyl chloride salt and dimethylaminoethylbenzyl methacrylate chloride salt are preferred.
[0037]
Examples of the silicone-based macromonomer for introducing a graft portion include a polyether-based compound in which a siloxane oxide is added to a hydroxyalkylene monomethacrylate using a cationic catalyst, polyesterification of a polybasic acid and a hydroxyl-containing silicone, and then glycidyl methacrylate and an ester. Particularly preferred is a compound obtained by introducing methacrylate into the terminal after methoxylation using a modified ester or water glass as a starting material.
[0038]
As the silicone-based macromonomer, a macromer in which dimethylsiloxane is bonded to a methacryloyl group directly or via an alkyl group is particularly preferable. For example, X-22-174DX (manufactured by Shin-Etsu Chemical Co., Ltd.), AK-5, AK-30, AK-32 (manufactured by Toagosei Co., Ltd.) and the like.
[0039]
Other preferable monomers that can be polymerized include methyl acrylate, ethyl acrylate, isopropyl acrylate, n-propyl acrylate, n-butyl acrylate, t-butyl acrylate, benzyl acrylate, methyl methacrylate , Ethyl methacrylate, isopropyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, tridecyl methacrylate, benzyl methacrylate, 2-ethylhexyl acrylate, methacrylic acid 2-ethylhexyl, octyl acrylate, octyl methacrylate, lauryl acrylate, lauryl methacrylate, cetyl acrylate, cetyl methacrylate, stearyl acrylate, stearyl methacrylate, behenyl acrylate, behe (Meth) acrylates such as methacrylate; styrene monomers such as styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-tert-butylstyrene; benzyl itaconate Maleic esters such as dimethyl maleate; fumaric esters such as dimethyl fumarate; acrylonitrile, methacrylonitrile, vinyl acetate; 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate; Hydroxyl-containing monomers such as hydroxypropyl acrylate and hydroxypropyl methacrylate; aminoethyl ethyl acrylate, aminopropyl acrylate, methacrylamide, aminoethyl methacrylate, aminopropyl methacrylate And amino group-containing monomers such as dimethylaminoethyl acrylate and dimethylaminoethyl methacrylate; and α-olefins such as ethylene.
[0040]
Examples of the catalyst include peroxides such as t-butyl peroxybenzoate, di-t-butyl peroxide, cumper hydroxide, acetyl peroxide, benzoyl peroxide, lauroyl peroxide; azobisisobutylnitrile, azobis-2. An azo compound such as 2,4-dimethylvaleronitrile and azobiscyclohexanecarbonitrile is preferred.
[0041]
Non-reactive solvents include aliphatic hydrocarbon solvents such as hexane and mineral spirit; aromatic hydrocarbon solvents such as benzene, toluene and xylene; ester solvents such as butyl acetate; methanol and butanol. Alcohol solvents such as methyl ethyl ketone and isobutyl methyl ketone; aprotic polar solvents such as dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone and pyridine; Further, these solvents may be used in combination.
[0042]
As the reaction method, known general methods such as bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, and redox polymerization are preferable, and among them, solution polymerization is more preferable because the reaction method is simple.
[0043]
The reaction conditions differ depending on the polymerization initiator and the solvent, but the reaction temperature is 180 ° C or lower, preferably 30 to 150 ° C, and the reaction time is 30 minutes to 40 hours, preferably 2 hours to 30 hours.
[0044]
As described above, in the present invention, the silicone graft polymer is adsorbed on the pigment to stabilize the dispersion of the pigment and prevent sedimentation. If the graft polymer is crosslinked and adsorbed on the particulate matter, the dispersion stability can be further improved.
[0045]
The bonding method of the crosslinking is preferably an ester bond, an amino bond, a urethane bond, an ether bond or a C—C bond by a radical reaction, and particularly preferably an ester bond from the viewpoint of the reaction rate, the reaction time, and the stability at the time of dispersion of the particulate matter. .
[0046]
As a method of crosslinking the silicone-based graft polymer to be self-dispersed, a method using a crosslinking agent and a method of introducing a crosslinking functional group into a polymer compound to be self-dispersed are preferable.
[0047]
As the crosslinking agent, those which react with the polar group in the silicone-based graft polymer are preferable, and amino resins such as melamine resin, benzoguanamine resin and urea resin, tolylene diisocyanate-based prepolymer, polyfunctional aromatic polyisocyanate, and diphenylmethane diamine Isocyanate resin such as isocyanate, hexamethylene diisocyanate prepolymer, xylene diisocyanate prepolymer and lysine isocyanate prepolymer, epoxy resin such as bisphenol A and acrylic resin having glycidyl group, Ti, Al, Zr And the like are preferred. Among these, amino resins and epoxy resins are particularly preferred in terms of reaction rate, reaction temperature and the like. Since the acrylic polymer compound has only one type of functional group, a cross-linking agent may be required.
[0048]
As the crosslinking functional group introduced into the silicone-based graft polymer, an amino group, a hydroxyl group, a methoxy group, and a glycidyl group are preferable. Among them, a hydroxyl group and a glycidyl group are particularly preferable in terms of reaction rate and reaction temperature.
[0049]
Examples of a method for introducing a cross-linking functional group include a method of polymerizing or condensing a monomer having a cross-linking functional group, a polyhydric alcohol, hydroxyamine or polyamine during the synthesis of a polymer compound having an acidic group, A method is preferred in which a prepolymer of a high molecular compound having a group is synthesized, and then a crosslinking functional group is introduced by polymerization, condensation or addition reaction. In particular, it goes without saying that the polymer compound self-disperses after the introduction of the crosslinking functional group.
[0050]
Monomers having a crosslinking functional group used in the synthesis of the silicone-based graft polymer include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, glycerol monomethacrylate, and polyethylene glycol monoacrylate. Hydroxyl-containing monomers such as methacrylate, propylene glycol monomethacrylate, polyethylene glycol monoacrylate, and propylene glycol monoacrylate; glycidyl group-containing monomers such as glycidyl acrylate and glycidyl methacrylate; and methoxy groups such as methoxypolyethylene glycol acrylate and methoxypolyethylene glycol methacrylate Amines such as monomers, acrylamide, methacrylamide, etc. Is preferably a group containing monomer, among others glycidyl group-containing monomer is caused to react after hydroxyl group, and more preferable because of improving the charge of particulate material.
[0051]
Further, in a method of introducing a crosslinking functional group by polymerization, condensation or addition reaction after synthesizing a prepolymer of a silicone-based graft polymer, a compound having a crosslinking functional group for introduction by polymerization, condensation or addition reaction is used. Has only to have two or more reactive groups, and is preferably a polyhydric alcohol, polyamine, hydroxyamine, bisphenol A, or polyisocyanate.
[0052]
In the ink for an ink jet printer of the present invention, a surfactant may be contained, if necessary, in addition to the above-mentioned basic components of the pigment, the organic solvent, and the silicone-based graft polymer.
[0053]
Surfactants are used to improve the surface tension of the ink and the wettability of the pigment, prevent drying in the head, and prevent bleeding into paper. Examples of the surfactant used in the ink for an inkjet printer of the present invention include an anionic surfactant, a cationic surfactant, a nonionic surfactant, and an amphoteric surfactant. Among these, particularly preferred surfactants are anionic surfactants and nonionic surfactants.
[0054]
Examples of the anionic surfactant include sodium stearate, fatty acid salts such as potassium soap oleate and semi-hardened tallow fatty acid soda soap, sodium lauryl sulfate, alkyl sulfates such as triethanolamine lauryl sulfate and higher alcohol sodium sulfate, Alkyl benzene sulfonates such as sodium dodecylbenzene sulfonate, alkyl naphthalene sulfonates such as sodium alkyl naphthalene sulfonate, alkyl sulfosuccinates such as sodium dialkyl sulfosuccinate, alkyl diphenyl ether disulfonates such as sodium alkyl diphenyl ether disulfonate, Alkyl phosphates such as potassium alkyl phosphate, sodium polyoxyethylene lauryl ether sulfate and polyoxyethylene alkyl sulfate Polyoxyethylene alkyl sulfate ester salts such Noruamin, alkyl aryl sulfates such as polyoxyethylene alkyl phenyl ether sodium sulfate, polyoxyethylene alkyl phosphate, naphthalene sulfonic acid formalin condensates preferred.
[0055]
Examples of the cationic surfactant include alkylamine salts such as coconutamine acetate and stearylamine acetate, quaternary ammonium salts such as lauryltrimethylammonium chloride, stearyltrimethylammonium chloride and alkylbenzyldimethylammonium chloride, laurylbetaine and stearylbetaine. And amine oxides such as lauryl dimethylamine oxide.
[0056]
Examples of the nonionic surfactant include polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene alkyl ether such as polyoxyethylene oleyl ether and polyoxyethylene higher alcohol ether, and polyoxyethylene octyl. Polyoxyethylene alkyl allyl ethers such as phenyl ether and polyoxyethylene nonylphenyl ether, polyoxyethylene derivatives, oxyethylene / oxypropylene block copolymers, sorbitan fatty acid esters, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate , Polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan tristearate Nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monooleate and polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitol fatty acid esters such as polyoxyethylene sorbite tetraoleate, and glycerin fatty acid esters Agents are preferred.
[0057]
The viscosity of the ink for an inkjet printer of the present invention is preferably in the range of 1 to 20 mP · s. If it is 1 mP · s or more, leakage of the ink from the cartridge is prevented, and if it is 20 mP · s or less, the flying property of the ink is stabilized. Further, considering high-speed response, 2 to 15 mP · s is more preferable.
[0058]
The ink for an ink jet printer of the present invention includes, for example, a dispersion obtained by dispersing a pigment (for example, an organic pigment) in an organic solvent in which the silicone-based graft polymer is dissolved by using a self-dispersing silicone-based graft polymer; The silicone-based graft polymer is precipitated by mixing with an organic solvent in which the system-based graft polymer does not dissolve and is adsorbed on the pigment, and then, if necessary, solvent replacement, addition of various additives, pigment concentration adjustment or filtration. And the like.
[0059]
More specifically, a dispersion step A in which a pigment (for example, an organic pigment) is dispersed in an organic solvent in which the silicone-based graft polymer is dissolved using a silicone-based graft polymer, and the silicone is dispersed in the dispersion obtained in the dispersion step A. The silicone-based graft polymer is precipitated by injecting an organic solvent in which the silicone-based graft polymer is not dissolved or by injecting and mixing the dispersion obtained in the dispersion step A into the organic solvent in which the silicone-based graft polymer is not dissolved. The dispersion composition is prepared by a production method comprising a mixing step B for adsorbing and adsorbing the pigment, a crosslinking step C for fixing the silicone-based graft polymer by crosslinking, if necessary, and a concentration step D for distilling off the solvent, if necessary. After the product is manufactured, various additives are added, the pigment concentration is adjusted, or filtration is performed.
[0060]
In the dispersion step A, after dissolving the silicone-based graft polymer in an organic solvent and adding a pigment, if necessary, using a dispersion medium such as glass beads, steel beads or zirconia beads, a bead mill such as a Dyno mill or a DSP-mill, Dispersion is obtained by a disperser such as a high-pressure injection mill such as a roll mill, a sand mill, an attritor, a kneader or a nanomizer to obtain a dispersion. If necessary, various additives such as a surfactant, a pigment dispersant, a pigment derivative, and a charge generating agent may be added.
[0061]
Dispersion conditions for dispersing with a dispersing machine depend on the type of pigment and the type of dispersing machine, but in consideration of economy and the like, the temperature is preferably in the range of 0 ° C. to 150 ° C. It is preferable in the range of time to 10 hours / kg in terms of productivity. The dispersed particle diameter after dispersion is preferably not more than submicron in volume average diameter, and more preferably not more than 0.5 micron in consideration of sedimentation and aggregation.
[0062]
The method for measuring the dispersed particle size is not particularly limited, but a known and commonly used method is used, for example, a particle size distribution measuring device of a laser scattering system or a centrifugal sedimentation system. Further, a crosslinking agent for crosslinking the silicone-based graft polymer is mixed before or after dispersion. In particular, it is preferable to mix after dispersion because there is no influence of a reaction or the like at the time of dispersion. The proportion of the crosslinking agent is not particularly limited as long as the silicone graft polymer can be fixed to the pigment by crosslinking, but is preferably in the range of 2 to 100 parts by weight with respect to 100 parts by weight of the silicone graft polymer. A range of parts by weight is more preferred.
[0063]
Next, in the mixing step B, an organic solvent in which the silicone-based graft polymer is not dissolved is added to the dispersion prepared in the dispersion step A, or an organic solvent in which the silicone-based graft polymer is not dissolved in the dispersion obtained in the dispersion step A. Add to the solvent slowly and mix. In this case, at or after the addition, the dispersion is uniformly mixed using a simple stirrer such as a three-one motor, a magnetic stirrer, a disper, or a homogenizer. Further, using a mixer such as a line mixer, the organic solvent in which the silicone-based graft polymer is not dissolved and the dispersion produced in the dispersion step A are mixed at once. Further, after the addition, a dispersing machine such as a bead mill or a high-pressure jet mill may be used in order to further refine the precipitated particles.
[0064]
The organic solvent in which the silicone-based graft polymer is not dissolved is not particularly limited as long as the silicone-based graft polymer is not dissolved, but an organic solvent having a solubility parameter of 7.8 or less is particularly preferred. Examples of the organic solvent having a solubility parameter of 7.8 or less include aliphatic hydrocarbons such as hexane, mineral spirit, and Isopar series manufactured by Exxon Chemical Co., and silicone cones such as dialkyl polysiloxane and cyclic polydialkyl siloxane. And vegetable oils such as olive oil, safflower oil, sunflower oil, soybean oil and linseed oil, and diethyl ether. The proportion of the organic solvent used here is preferably in the range of 0 to 10,000 parts by weight based on 100 parts by weight of the silicone-based graft polymer in order to increase the pigment concentration in the dispersion composition to be produced.
[0065]
In the crosslinking step C in which the silicone-based graft polymer is fixed by crosslinking, the crosslinking method is not particularly limited, and examples thereof include a crosslinking method using heating, ultraviolet rays, an electron beam, or the like. In particular, a method by heating is preferred because of the reactivity and the fact that the reaction can be carried out with a simple apparatus. The temperature of the crosslinking by heating is not particularly limited as long as the dispersion state of the pigment is not destroyed, but is preferably 200 ° C. or lower, more preferably 180 ° C. or lower.
[0066]
The concentration step D is performed according to the pigment concentration and the ink characteristics. Further, the concentration step may be performed before the crosslinking step C. As a method for concentrating the solvent, a general normal pressure or reduced pressure distillation method can be used. For example, when an ink-jet ink is formed using a silicone-based solvent, an organic solvent that dissolves the silicone-based graft polymer is concentrated by normal pressure or reduced-pressure distillation using a solvent having a boiling point lower than that of the silicone-based solvent. On the other hand, when an inkjet ink is formed using an organic solvent that dissolves the silicone-based graft polymer, a silicone-based solvent having a boiling point lower than that of the organic solvent that dissolves the silicone-based graft polymer is used, and concentrated by distillation under normal pressure or reduced pressure. .
[0067]
Further, the ink for an inkjet printer of the present invention is adjusted to a predetermined particulate matter concentration or a predetermined binder concentration by adding a binder and / or an organic solvent according to each application. As the binder, for example, natural proteins, celluloses, polyvinyl alcohol, polyacrylamide, aromatic amide, polyacrylic acid, polyvinyl ether, polyvinylpyrrolidone, acrylic, polyester, alkyd, urethane, amide resin, melamine resin, ether resin, fluorine Resins, synthetic polymers such as styrene acrylic resin and styrene maleic resin, photosensitive resins, thermosetting resins, ultraviolet curable resins, and electron beam curable resins are preferred.
[0068]
The ink for an inkjet printer according to the present invention, if necessary, may include an anti-peeling agent, a leveling agent, a charge control agent such as metal soap and lecithin, a wetting agent, a preservative, a deodorant, a fragrance, a pigment dispersant, and a pigment derivative. Can be further blended.
[0069]
The method of adjusting by adding the binder, the organic solvent and various additives to the ink for an ink jet printer of the present invention may use a simple stirrer such as a disperser, and does not require a conventional disperser or the like. Energy saving and low-cost production.
[0070]
As a printer to which the ink for an inkjet printer of the present invention is applied, a recording head having a plurality of ink ejection ports and energy conversion means for converting electrical energy into ink ejection energy corresponding to the plurality of ejection ports is provided. It is an inkjet printer equipped with. For example, a known general piezo system or a thermal system such as a bubble jet printer is used. In particular, a piezo-type printer is preferable in view of safety because an organic solvent is used.
[0071]
【Example】
Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. In the following description, “parts” and “%” mean “parts by weight” and “% by weight” unless otherwise specified. In addition, all reagents without precautionary statements used were reagent grade 1 manufactured by Wako Pure Chemical Industries.
Synthesis Example 1(Preparation of silicone-based graft polymer)
16.1 parts of n-butyl methacrylate
Lauryl methacrylate 10.0 parts
Styrene 35.0 parts
6.9 parts of methacrylic acid
Glycidyl methacrylate 12.0 parts
X-22-174DX (Shin-Etsu Chemical Co., Ltd.) 20.0 parts
Perbutyl O (Peroxyester manufactured by NOF Corporation) 8.0 parts
These components were mixed to prepare a solution.
[0072]
Next, 100 parts of methyl ethyl ketone (Wako Pure Chemical Industries, Ltd. reagent grade 1) was weighed into a reaction vessel equipped with a nitrogen inlet tube, and the temperature was raised to 75 ° C. while sealing with nitrogen. The solution was added dropwise over 4 hours, and after the completion of the addition, the solution was reacted at 75 ° C. for 6 hours. The solution after the reaction was a silicone-based graft polymer having a nonvolatile content of 46.1%, an acid value of 44.0 KOH mg / g, and a number average molecular weight of 11,800.
[0073]
One part of this polymer compound was diluted with dimethylsiloxane solvent KF-96L-1.0 (manufactured by Shin-Etsu Chemical Co., Ltd.). When 0.5 part of the dimethylsiloxane solvent was added, the dispersion was self-dispersed to obtain a dispersion having an average particle size of 0.045 μm (measured with a laser Doppler type particle size distribution meter N4 PLUS manufactured by Coulter).
[0074]
Further, 1 part of this polymer compound was diluted with an aliphatic hydrocarbon solvent Isoaper G (manufactured by Exxon Chemical Co., Ltd.). When 1.0 part of Isopar G was added, the dispersion was self-dispersed to obtain a dispersion having an average particle size of 0.048 μm (measured with a laser Doppler type particle size distribution meter N4 PLUS manufactured by Coulter).
[0075]
Synthesis Example 2(Preparation of silicone-based graft polymer)
n-butyl methacrylate 21.0 parts
Styrene 25.0 parts
15.0 parts of 2-hydroxyethyl methacrylate
Lauryl methacrylate 10.0 parts
X-22-174DX (Shin-Etsu Chemical Co., Ltd.) 20.0 parts
Glycidyl methacrylate 12.0 parts
Butyl O (Peroxyester manufactured by NOF Corporation) 8.0 parts
These components were mixed to prepare a solution.
[0076]
Next, 100 parts of methyl ethyl ketone (Wako Pure Chemical Industries, Ltd. reagent grade 1) was weighed into a reaction vessel equipped with a nitrogen inlet tube, and the temperature was raised to the boiling point while sealing with nitrogen. The solution was added dropwise over 4 hours, and after the completion of the addition, the mixture was reacted for 6 hours while refluxing. The solution after the reaction was a polymer compound having a nonvolatile content of 45.6%, a hydroxyl value of 64.0 KOH mg / g, and a number average molecular weight of 10,400.
[0077]
One part of this polymer compound was diluted with dimethylsiloxane solvent KF-96L-1.0 (manufactured by Shin-Etsu Chemical Co., Ltd.). When 0.5 part of a dimethylsiloxane solvent was added, the dispersion was self-dispersed to obtain a dispersion having an average particle size of 0.105 μm (measured by a laser Doppler type particle size distribution meter N4 PLUS manufactured by Coulter).
[0078]
Synthesis Example 3(Preparation of silicone-based graft polymer)
28.1 parts of n-butyl methacrylate
Lauryl methacrylate 10.0 parts
Styrene 35.0 parts
6.9 parts of methacrylic acid
X-22-174DX (Shin-Etsu Chemical Co., Ltd.) 20.0 parts
Perbutyl O (Peroxyester manufactured by NOF Corporation) 8.0 parts
These components were mixed to prepare a solution.
[0079]
Next, 100 parts of methyl ethyl ketone (Wako Pure Chemical Industries, Ltd. reagent grade 1) was weighed into a reaction vessel equipped with a nitrogen inlet tube, and the temperature was raised to the boiling point while sealing with nitrogen. The solution was added dropwise over 2 hours, and after the completion of the addition, the mixture was reacted for 14 hours under reflux. The solution after the reaction was a silicone-based graft polymer having a nonvolatile content of 47.0%, an acid value of 44.5 KOH mg / g, and a number average molecular weight of 9,900.
[0080]
One part of this polymer compound was diluted with dimethylsiloxane solvent KF-96L-1.0 (manufactured by Shin-Etsu Chemical Co., Ltd.). When 0.3 part of the dimethylsiloxane solvent was added, the dispersion was self-dispersed to obtain a dispersion having an average particle size of 0.119 μm (measured with a laser Doppler type particle size distribution meter N4 PLUS manufactured by Coulter).
[0081]
Synthesis Example 4(Preparation of silicone-based graft polymer)
26.8 parts of n-butyl methacrylate
Styrene 30.0 parts
2-hydroxyethyl methacrylate 10.5 parts
12.7 parts of 4-vinylpyridine
X-22-174DX (Shin-Etsu Chemical Co., Ltd.) 20.0 parts
Perbutyl O (Peroxyester manufactured by NOF Corporation) 8.0 parts
These components were mixed to prepare a solution.
[0082]
Next, 100 parts of methyl ethyl ketone (Wako Pure Chemical Industries, Ltd. reagent grade 1) was weighed into a reaction vessel equipped with a nitrogen inlet tube, and the temperature was raised to the boiling point while sealing with nitrogen. The solution was added dropwise over 2 hours, and after the completion of the addition, the mixture was reacted for 14 hours under reflux. The solution after the reaction was a polymer compound having a nonvolatile content of 48.6%, a hydroxyl value of 44.0 KOH mg / g, an amine value of 65.1 KOH mg / g, and a number average molecular weight.
[0083]
One part of this polymer compound was diluted with dimethylsiloxane solvent KF-96L-1.0 (manufactured by Shin-Etsu Chemical Co., Ltd.). When 0.3 part of the dimethylsiloxane solvent was added, the dispersion was self-dispersed to obtain a dispersion having an average particle size of 0.09 μm (measured by a laser Doppler type particle size distribution meter N4 PLUS manufactured by Coulter).
[0084]
Synthesis Example 5(Preparation of polymer)
16.1 parts of n-butyl methacrylate
Lauryl methacrylate 30.0 parts
Styrene 35.0 parts
6.9 parts of methacrylic acid
Glycidyl methacrylate 12.0 parts
Perbutyl O (Peroxyester manufactured by NOF Corporation) 8.0 parts
These components were mixed to prepare a solution.
[0085]
Next, 100 parts of methyl ethyl ketone (Wako Pure Chemical Industries, Ltd. reagent grade 1) was weighed into a reaction vessel equipped with a nitrogen inlet tube, and the temperature was raised to the boiling point while sealing with nitrogen. The solution was added dropwise over 4 hours, and after the completion of the addition, the mixture was reacted for 6 hours while refluxing. The solution after the reaction was a polymer compound having a nonvolatile content of 47.3%, an acid value of 44.2 KOHmg / g, and a number average molecular weight of 9,800.
[0086]
One part of this polymer compound was diluted with dimethylsiloxane solvent KF-96L-1.0 (manufactured by Shin-Etsu Chemical Co., Ltd.). When 0.8 part of the dimethylsiloxane solvent was added, the dispersion became cloudy and agglomerated, resulting in a dispersion having an average particle size of 1.25 μm (measured with a laser Doppler type particle size distribution meter N4 PLUS manufactured by Coulter).
[0087]
Table 1 shows various characteristics of Synthesis Example 1 to Synthesis Example 5.
[0088]
[Table 1]
Table 1

[0089]
Example 1
Dinomill KDL type with 300cc glass container,
130.0 parts of silicone-based graft polymer of Synthesis Example 1
Fastogen Blue TGR as a pigment
(Copper phthalocyanine blue pigment manufactured by Dainippon Ink and Chemicals, Inc.) 57.0 parts
Solsperse 5000 as a phthalocyanine pigment derivative 3.0 parts
Methyl ethyl ketone 37.0 parts
KF-96L-2 37.0 parts
3mmφ zirconia beads 250cc
And cooled with water at 5 ° C., and dispersed at 1,000 rpm for 2 hours.
Got Lee. afterwards,
13.2 parts of the above dispersed slurry
Methyl ethyl ketone 30.9 parts
KF-96L-2 30.9 parts
Were mixed to obtain a mixed solution.
[0090]
Next, 75 parts of KF-96L-2 was weighed as a silicone solvent, placed in a 300 cc eggplant flask, and stirred with a magnetic stirrer. While stirring, the mixture was slowly added dropwise to precipitate a silicone-based graft polymer on the surface of the granular material.
[0091]
After the dropwise addition, the solvent was removed from the methyl ethyl ketone by distillation under reduced pressure, followed by a crosslinking reaction at 120 ° C. for 5 hours to obtain a dispersion composition having a pigment concentration of 4.75%. The obtained dispersion composition has a dispersion particle size of 0.125 μm (measured with a laser Doppler type particle size distribution meter N4 PLUS manufactured by Coulter Co., Ltd.), and this dispersion composition is prepared using KF-96L-1. The concentration of non-volatile components was adjusted to 5%, and the centrifugal force of 33,500 G was applied for 5 hours to measure the amount of resin adsorbed by centrifugal sedimentation from the non-volatile components of the supernatant. Was adsorbed. 1 and 2 show transmission electron micrographs before and after adsorption of the polymer of the organic pigment in the dispersion composition, respectively. As shown in FIG. 2, it can be confirmed that the polymer which is not seen in the case of the organic pigment alone in FIG. 1 is clearly adsorbed on the pigment surface in the organic pigment having the polymer adsorbed thereon.
[0092]
Further, 10 parts of KF-96-10 and KF-96L-2 were added to the dispersion composition in an amount of 3 parts (63.1 parts) in terms of pigment to make the total amount 100 parts, and the mixture was filtered through a 1 μm filter. , To prepare an oil-based inkjet printer ink having a pigment concentration of 3%.
[0093]
As shown in Table 3 below, this ink had a small particle size and a low viscosity, did not change after the storage test, and did not show sedimentation. Also in the printing test, it showed very excellent characteristics in printing stability and re-discharge property.
[0094]
Comparative Example 1
In a 500cc plastic bottle,
Fastogen Blue TGR as a pigment
(Copper phthalocyanine blue pigment manufactured by Dainippon Ink and Chemicals, Inc.) 3.0 parts
MGS-F75 (Nonionic surfactant manufactured by Nikko Chemicals) 0.5 part
Tamanor 135 (Rosin resin manufactured by Arakawa Chemical Co.) 3.0 parts
Techno Care FRV (Toshiba Silicone Silicone Oil) 29.5 parts
Techno Care FRV (Toshiba Silicone Silicone Oil) 5.0 parts
KF-96L-2 (Shin-Etsu Chemical's dimethylsiloxane) 37.0 parts
Oleyl alcohol 22.0 parts
300 parts of 3mmφ zirconia beads
Was measured and dispersed with a paint shaker (manufactured by Aishin) for 2 hours to produce an oil-based inkjet ink.
[0095]
As shown in Table 3 below, this ink was larger in particle size and viscosity than in Example 1, and increased in particle size and viscosity after storage test, sedimentation was observed, and was inferior in print stability and redispersibility.
[0096]
Example 2
The same as Example 1 except that Fastogen Blue TGR pigment used in Example 1 and Cinquasia Magenta RT-355-D (manufactured by Ciba Specialty Chemical Co.) were used instead of Solsperse 5000, as shown in Table 2 below. A dispersion composition was prepared.
[0097]
Further, an oil-based inkjet printer ink having a pigment concentration of 3% was prepared in the same manner as in Example 1. As shown in Table 3, this ink had a small particle size and a low viscosity, did not change after the storage test, and did not show any sedimentation. Also in the printing test, it showed very excellent characteristics in printing stability and re-discharge property.
[0098]
Comparative Example 2
In the same manner as in Example 1 except that 126.8 parts of the polymer of Synthesis Example 5 and 3.2 parts of methyl ethyl ketone were used instead of 130.0 parts of the silicone-based graft polymer of Synthesis Example 1 used in Example 2, The dispersion compositions shown in Table 2 below were prepared.
[0099]
Further, an oil-based inkjet printer ink having a pigment concentration of 3% was prepared in the same manner as in Example 2. As shown in Table 3 below, this ink had a larger particle size than Example 2, and sedimentation was observed after the storage test. Also, in the printing test, ejection failure occurred, and the printing stability and re-ejection property were poor.
[0100]
Example 3
A dispersion composition shown in Table 2 below was prepared in the same manner as in Example 1 except that Yellow HG (manufactured by Clariant) was used instead of Fastogen Blue TGR pigment and Solsperse 5000 used in Example 1.
[0101]
Further, an oil-based inkjet printer ink having a pigment concentration of 3% was prepared in the same manner as in Example 1. As shown in Table 3 below, this ink had a small particle size and a low viscosity, did not change after the storage test, and did not show sedimentation. Also in the printing test, it showed very excellent characteristics in printing stability and re-discharge property.
[0102]
Example 4
A dispersion composition shown in Table 2 below was prepared in the same manner as in Example 1 except that Printex 85 (carbon black pigment manufactured by Degussa) was used instead of the Fastogen Blue TGR pigment used in Example 1. .
[0103]
Further, an oil-based inkjet printer ink having a pigment concentration of 3% was prepared in the same manner as in Example 1. As shown in Table 3 below, this ink had a small particle size and a low viscosity, did not change after the storage test, and did not show sedimentation. Also in the printing test, it showed very excellent characteristics in printing stability and re-discharge property.
[0104]
Comparative Example 3
In a 500cc plastic bottle,
Printex 85 as pigment
(Carbon black pigment manufactured by Degussa) 10.0 parts
Nonion OP80R (Nonionic surfactant manufactured by NOF Corporation) 2.5 parts
Tamanoru 510 (Arakawa Chemical Co., Ltd. phenolic resin) 15.0 parts
Isopar L oleyl alcohol 75.0 parts
300 parts of 3mmφ zirconia beads
Was measured and dispersed with a paint shaker (manufactured by Aishin) for 2 hours to produce an oil-based inkjet ink.
[0105]
As shown in Table 3 below, this ink was larger in particle size and viscosity than in the above examples, settled out, and was poor in print stability.
[0106]
Example 5
Example 1 was repeated except that 131.6 parts of the silicone-based graft polymer of Synthesis Example 1 and 37 parts of methyl ethyl ketone used in Example 1 were replaced with 131.6 parts of the polymer of Synthesis Example 2 and 35.4 parts of methyl ethyl ketone. Similarly, dispersion compositions shown in Table 2 below were prepared.
[0107]
Further, an oil-based inkjet printer ink having a pigment concentration of 10% was prepared in the same manner as in Example 1. As shown in Table 3 below, this ink had a small particle size and a low viscosity, did not change after the storage test, and did not show sedimentation. Also in the printing test, it showed very excellent characteristics in printing stability and re-discharge property.
[0108]
Example 6
Dinomill KDL type with 300cc glass container,
127.7 parts of silicone-based graft polymer of Synthesis Example 3
Fastogen Blue TGR as a pigment
(Copper phthalocyanine blue pigment manufactured by Dainippon Ink and Chemicals, Inc.) 57.0 parts
Solsperse 5000 as a phthalocyanine pigment derivative 3.0 parts
39.3 parts of methyl ethyl ketone
KF-96L-2 37.0 parts
3mmφ zirconia beads 250cc
And cooled with water at 5 ° C., and dispersed at 1,000 rpm for 2 hours.
Got Lee. afterwards,
13.2 parts of the above dispersed slurry
Methyl ethyl ketone 30.9 parts
KF-96L-2 30.9 parts
Were mixed to obtain a mixed solution.
[0109]
Next, 75 parts of KF-96L-2 was weighed as a silicone solvent, placed in a 300 cc eggplant flask, and stirred with a magnetic stirrer. While stirring, the mixture was slowly added dropwise to precipitate a silicone-based graft polymer on the surface of the granular material.
[0110]
After the dropwise addition, the solvent was removed from the methyl ethyl ketone by distillation under reduced pressure to obtain a dispersion composition having a pigment concentration of 4.85%. The obtained dispersion composition has a dispersion particle size of 0.174 μm (measured with a laser Doppler type particle size distribution meter N4 PLUS manufactured by Coulter Co., Ltd.), and this dispersion composition is prepared using KF-96L-1. The non-volatile content was adjusted to 5%, and the amount of resin adsorbed by centrifugal sedimentation from the supernatant non-volatile content was measured by applying a centrifugal force of 33,500 G for 5 hours. It had been.
[0111]
Further, KF-96L-2 was added to 10 parts of KF-96-10 and 3 parts (61.9 parts) of the above-mentioned dispersion composition in terms of pigment to make the total amount 100 parts, and the mixture was filtered through a filter having a diameter of 1 μm. And an oil-based inkjet printer ink having a pigment concentration of 3% was prepared.
[0112]
As shown in Table 3 below, this ink had a small particle size and a low viscosity, did not change after the storage test, and did not show sedimentation. Also in the printing test, it showed very excellent characteristics in printing stability and re-discharge property.
[0113]
Example 7
Example 13 Except that 123.5 parts of the polymer of Synthesis Example 4 and 43.5 parts of methyl ethyl ketone were used instead of 127.7 parts of the silicone-based graft polymer of Synthesis Example 2 and 39.3 parts of methyl ethyl ketone used in Example 5. In the same manner as in Example 1, a dispersion composition shown in Table 2 below was prepared.
[0114]
Further, an oil-based inkjet printer ink having a pigment concentration of 3% was prepared in the same manner as in Example 5. As shown in Table 3 below, this ink had a small particle size and a low viscosity, did not change after the storage test, and did not show sedimentation. Also in the printing test, it showed very excellent characteristics in printing stability and re-discharge property.
[0115]
Here, the pigment concentration was measured by weighing about 2 g of the dispersion composition in an aluminum dish and drying it in an oven at 220 ° C. for 60 minutes.
[0116]
In Table 2 below, the dispersion particle size was measured by a laser Doppler type particle size distribution meter N4 PLUS manufactured by Coulter Corporation. The amount of adsorption was determined by adjusting the dispersion composition to KF-96L-1 (manufactured by Shin-Etsu Chemical Co., Ltd.) to adjust the non-volatile content to 5%, and applying a centrifugal force of 33,500 G for 5 hours to centrifugal sedimentation from the non-volatile content of the supernatant. The amount of resin adsorbed on the pigment 100 was measured.
[0117]
[Table 2]
Table 2

[0118]
Next, the characteristics of the oil-based inkjet printer ink were examined. Here, the particle size was measured with a laser Doppler type particle size distribution meter N4 PLUS manufactured by Coulter Corporation. The viscosity was measured with an R-type viscometer manufactured by Toki Sangyo Co., Ltd. at a rotation speed of 100 rpm. In the case where the measurement could not be performed at 100 rpm, the measurement was performed at a reduced rotation speed. In the storage test, 40 g of the ink was weighed and sealed in a 60 cc glass container, and left in a 60 ° C. constant temperature bath for 2 weeks. As a result, な い indicates that no sediment was observed, and X indicates that sediment was observed. The printing test was performed by filling in Epson C-520 ink cartridges and printing on A4 paper with a C-520 ink jet printer.た indicates that cleaning was required but continuous printing of 1,000 or more sheets was performed, and △ indicates that clogging occurred and printing became impossible. The re-ejecting property was as follows. The ink was set in a C-520 ink jet printer, left at room temperature for one month, and a printing test was performed again. Those indicating printing were indicated by Δ, and those not showing stable printing were indicated by X. Table 3 shows the results.
[0119]
[Table 3]
Table 3

[0120]
【The invention's effect】
As described above, the ink for an oil-based inkjet printer of the present invention has improved dispersion stability such as sedimentation and storage stability of a pigment, and has improved printing stability. In addition, the use of pigments and organic solvents can improve print quality such as water resistance and light resistance, and the use of highly safe, high boiling point silicone-based organic solvents can increase the safety of ink. did it.
[Brief description of the drawings]
FIG. 1 is an electron micrograph of an organic pigment in a dispersion composition in Example 1 before polymer adsorption.
FIG. 2 is an electron micrograph of an organic pigment in a dispersion composition in Example 1 after adsorption of a polymer.

Claims (22)

In an inkjet printer ink containing a pigment and an organic solvent,
A silicone-based graft polymer is blended, and the silicone-based graft polymer is adsorbed on at least a part of the outer surface of the pigment, and has a particle size of 0.01 μm to 0.3 μm in the organic solvent. An ink for an ink-jet printer, characterized by being dispersed in the form of particles having the following formula: The inkjet according to claim 1, wherein the pigment is selected from the group consisting of an inorganic pigment, an organic pigment, and a dye that does not dissolve in a solvent, and a particle size of the pigment is in a range of 0.01 µm to 0.3 µm. Printer ink. 2. The ink for an ink jet printer according to claim 1, wherein the silicone-based graft polymer is adsorbed within a range of 5 parts by weight to 3000 parts by weight with respect to 100 parts by weight of the pigment. 3. The pigment is an organic pigment and / or carbon black, and the silicone-based graft polymer is adsorbed on at least a part of the outer surface of the organic pigment and / or carbon black. 3. The ink for an ink jet printer according to claim 1, wherein the ink is dispersed into particles having a particle diameter in a range of 0.3 μm. The organic solvent is a solvent having a small polarity and an electric resistivity of 10 ⁹ Ω · cm or more, and the organic solvent is blended in a proportion within a range of 50 to 10000 parts by weight with respect to 100 parts by weight of the pigment. The ink for an ink jet printer according to claim 1, wherein: 6. The ink for an ink jet printer according to claim 1, wherein the organic solvent is a silicone-based organic solvent. 7. The ink for an ink jet printer according to claim 6, wherein the silicone-based organic solvent has a methylpolysiloxane and / or cyclic methylpolysiloxane structure. The ink for an inkjet printer according to claim 1, wherein the silicone-based graft polymer has a polar group. The ink for an inkjet printer according to claim 8, wherein the polar group is selected from at least a carboxyl group, a hydroxyl group, and an amino group. The ink for an ink jet printer according to claim 1, wherein the silicone graft polymer has an acid value in a range of 5 to 100 KOHmg / g. The ink for an inkjet printer according to claim 1, wherein the hydroxyl value of the silicone-based graft polymer is in a range of 5 to 100 KOHmg / g. 2. The ink for an ink jet printer according to claim 1, wherein the amine value of the silicone-based graft polymer is in the range of 5 to 100 KOHmg / g. The ink for an inkjet printer according to claim 1, wherein the number average molecular weight of the silicone-based graft polymer is 2,000 or more and 50,000 or less. The ink for an ink jet printer according to claim 1, wherein the silicone-based graft polymer is an acrylic polymer compound. The ink for an ink jet printer according to claim 1, wherein the molecular weight of the graft portion of the silicone-based graft polymer is in the range of 500 to 10,000. The ink for an inkjet printer according to claim 1, wherein the silicone-based graft polymer is cross-linked and further adsorbed on the pigment. 17. The ink for an ink jet printer according to claim 16, wherein the cross-linking is an ester bond. The ink for an inkjet printer according to claim 1, wherein the silicone-based graft polymer has two or more crosslinking functional groups capable of undergoing a crosslinking reaction with an acidic group. 19. The ink according to claim 18, wherein the crosslinking functional group is a glycidyl group or a hydroxyl group. Claims: Used for an ink jet printer having a recording head having a plurality of ink ejection ports and energy conversion means for converting electrical energy into ink ejection energy corresponding to the plurality of ejection ports. Item 7. An ink for an ink jet printer according to item 1. From the group consisting of binders, organic solvents, anionic, cationic and nonionic surfactants, preservatives, deodorants, anti-peeling agents, fragrances, pigment dispersants, pigment derivatives, leveling agents, charge control agents and wetting agents The ink for an inkjet printer according to claim 1, further comprising at least one additional additive selected. The ink for an ink jet printer according to claim 1, having a viscosity in the range of 1 to 20 mP · s.

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