JP5704384B2 - Ink jet recording ink, cartridge, ink jet recording apparatus, image formed product - Google Patents

Description

  The present invention relates to an image forming method using a pretreatment liquid, an ink jet ink, a set with an ink jet recording ink, a cartridge, an ink jet recording method and apparatus, and an image formed article formed thereby.

  In recent years, as an image forming method, the process is simpler than other recording methods, and it is easy to achieve full color, and even with an apparatus with a simple configuration, there is an advantage that a high-resolution image can be obtained. Inkjet recording systems have become widespread.

  Inkjet recording methods use a bubble generated by heat, or a small amount of ink that is ejected by pressure generated using piezo or static electricity, and is attached to an image forming body such as paper and dried quickly (or an image forming body). An image forming apparatus that forms an image) and has been expanded to personal and industrial printers and printing applications.

In recent years, demand for industrial applications has increased, and high-speed printing and compatibility with various recording media (paper and other media) are desired. In particular, an ink jet printer equipped with a line head has become necessary as the speed increases.
In recent years, there has been an increasing demand for water-based inks from the viewpoints of environment and safety.

However, water-based ink is easily affected by the recording medium, and causes various problems in the image. This is particularly noticeable when non-smooth paper is used as the recording medium.
In the case of water-based ink, it takes time to dry and the compatibility with paper is good, so it has high permeability to paper, especially in the case of uncoated and relatively non-smooth paper, the coloring material penetrates into the paper. As a result, the color density of the formed color material becomes low, which is a problem not seen with solvent inks.

In particular, as high-speed printing progresses in recent years, in order to increase the drying speed of ink adhering to the medium, means for increasing the drying speed is taken by adding a penetrant to the ink and allowing water as a solvent to permeate the medium.
However, when a penetrating agent is included, not only water but also the permeability of the coloring material to the media is improved, and the problem that the image density is further lowered differs from the ink used for paints and ballpoint pens. Resulting in.

Conventionally, proposals have been made to use amphoteric surfactants in inks. For example, an amphoteric surfactant such as an alkylamine oxide or an alkylaminobetaine as an additive to an ink containing a pigment dispersed with a dispersant having a carboxy group in order to improve the ejection properties of the ink from the ink head during image formation Has been proposed (Patent Document 1).
As an example of the dispersant, use of alkyldimethylglycine is also described.

However, as described above, there is a problem that carbon black does not stay on the paper and penetrates into the paper and the image density decreases. In addition, when alkyldimethylglycine is used as a dispersant, carbon black can be dispersed up to the particle size and viscosity characteristics suitable for inkjet in the case of neutral or basic carbon black, but the dispersibility for acidic carbon black Is low and cannot be used for inkjet. In the case of neutral or basic carbon black, there is a problem that the image density is low as described above.
In order to improve the foaming property of the ink, an amphoteric surfactant such as alkylaminobetaine and an antifoaming agent are used as additives (Patent Document 2), and a cationic surfactant is added to the first ink. Although it has been proposed that the inclusion and the second ink contain an amphoteric surfactant (Patent Document 3), there is a problem that the dispersibility or the image density is low as described above.

  The present invention has been made in view of the above prior art, and when used in an ink jet ink with good dispersibility of pigment, an image forming method and an ink jet ink capable of realizing a high image density even on smooth paper and non-smooth paper It is an object to provide a liquid, a set of pretreatment liquid and ink for ink jet recording, a cartridge, an ink jet recording apparatus, and an image formed product.

The said subject is solved by following (1)-( 8 ) of this invention.
(1) “Pigment dispersion containing pigment particles finely dispersed in a dispersion medium liquid for preparing an ink for ink jet recording, wherein the pigment particles are acidic carbon black, and the following general formula (I A pigment dispersion for an ink for ink jet recording, comprising at least one compound represented by formula (1) and having a pH of 9.5 to 12.

（式中、ＭはＨまたはＬｉ、Ｎａ、Ｋ等のアルカリ金属、有機塩基を表し、ｎは１０〜１６の整数を表す。）」；
（２）「水、浸透剤、及び微分散された顔料を含むｐＨ９．５〜１１に調整されたインクジェット記録用インクであって、前記第（１）項に記載の顔料分散体を用いたことを特徴とするインクジェット記録用インク。」；
（３）「分散媒体液中に微分散された顔料粒子を含みインクジェット記録用インクの調製のための顔料分散体の製造方法であって、前記顔料粒子が酸性カーボンブラックであり、つぎの一般式（Ｉ）で表される化合物を少なくとも一種類以上含有する前記分散媒体液中で、該顔料粒子を、ｐＨが９．５〜１２の条件下で、微分散処理する工程を少なくとも有することを特徴とするインクジェット記録用インクのための顔料分散体の製造方法。

(Wherein M represents H or an alkali metal such as Li 2 , Na, K, or an organic base, and n represents an integer of 10 to 16). ”
(2) "water, penetrant, and an inkjet recording ink which is adjusted to pH9.5~11 containing finely dispersed pigment, wherein the first (1) for using the pigment dispersion according to claim Ink for ink-jet recording, characterized by: "
( 3 ) “A method for producing a pigment dispersion for the preparation of an ink for ink jet recording comprising pigment particles finely dispersed in a dispersion medium liquid, wherein the pigment particles are acidic carbon black, It has at least a step of finely dispersing the pigment particles under the condition of pH 9.5 to 12 in the dispersion medium liquid containing at least one compound represented by (I). A method for producing a pigment dispersion for an inkjet recording ink.

（式中、ＭはＨまたはＬｉ、Ｎａ、Ｋ等のアルカリ金属、有機塩基を表し、ｎは１０〜１６の整数を表す。）」；
（４）「水性液媒体中に、分散された顔料粒子を含むインクジェット記録用インクの製造方法において、分散媒体液中に微分散された酸性カーボンブラック顔料粒子とつぎの一般式（Ｉ）で表される化合物を少なくとも一種類以上含有しｐＨが９．５〜１２であるインクジェット記録用インクのための顔料分散体を、水および浸透剤を含む水系液媒体と混合してｐＨが９．５〜１１のインク液を調製する工程を少なくとも有することを特徴とする中にインクジェット記録用インクの製造方法。

(Wherein M represents H or an alkali metal such as Li 2 , Na, K, or an organic base, and n represents an integer of 10 to 16). ”
( 4 ) “In the method for producing an ink for inkjet recording containing pigment particles dispersed in an aqueous liquid medium, the acidic carbon black pigment particles finely dispersed in the dispersion medium liquid and the following general formula (I): A pigment dispersion for an ink jet recording ink containing at least one kind of compound and having a pH of 9.5 to 12 is mixed with an aqueous liquid medium containing water and a penetrant to have a pH of 9.5 to 9.5. 11. A method for producing an ink for ink jet recording, comprising at least a step of preparing 11 ink liquids.

（式中、ＭはＨまたはＬｉ、Ｎａ、Ｋ等のアルカリ金属、有機塩基を表し、ｎは１０〜１６の整数を表す。）」；
（５）「前記第（２）項に記載のインクジェット記録用インクを容器中に収容したことを特徴とするカートリッジ。」；
（６）「前記第（５）項に記載のカートリッジを搭載したインクジェット記録装置。」；
（７）「記録液を微細な吐出口から液滴として吐出、飛翔させることにより、記録媒体に画像を形成するインクジェット記録方法であって、該記録液として、前記第（２）項に記載のインクジェット記録用インクを用いることを特徴とするインクジェット記録方法。」；
（８）「前記第（６）項に記載のインクジェット記録装置で印字された画像形成物。」。

(Wherein M represents H or an alkali metal such as Li 2 , Na, K, or an organic base, and n represents an integer of 10 to 16). ”
( 5 ) "A cartridge characterized in that the ink for ink jet recording according to item (2) is contained in a container."
( 6 ) "Inkjet recording apparatus including the cartridge according to item ( 5 )";
( 7 ) “An ink jet recording method for forming an image on a recording medium by ejecting and flying a recording liquid as droplets from a fine ejection port, wherein the recording liquid is described in (2) above. An ink jet recording method using an ink for ink jet recording. ";
( 8 ) “Image formed product printed by the ink jet recording apparatus according to item ( 6 )”.

  As will be understood from the following detailed and specific description, according to the present invention, high image density can be realized even on smooth paper and non-smooth paper, and an image forming method, an ink jet ink, a cartridge, an ink jet recording apparatus, An extremely excellent effect that an image formed product can be provided is achieved.

It is an inkjet recording device figure in this invention. 2 is an example of a recording head in the present invention. It is another example of the recording head in this invention. FIG. 3 is an external perspective view of the cartridge before being loaded into the recording apparatus according to the present invention. It is a front sectional view of the cartridge in the present invention.

Hereinafter, the present invention will be described in detail and specifically.
The pigment dispersion for the inkjet recording ink of the present invention includes pigment particles finely dispersed in a dispersion medium liquid, and the pigment particles are acidic carbon black, and are represented by the following general formula (I): It is characterized in that it contains at least one compound and has a pH of 9.5 to 12, and the ink for ink jet recording of the present invention comprises water, a penetrating agent, and a finely dispersed pigment. The ink for ink jet recording further comprises at least one compound represented by the following general formula (I), preferably having a pH of 9.5 to 11 It is characterized by being.
Dodecibis- (aminoethyl) glycine used in the present invention is represented by the general formula (I), has both a cationic site and an anionic site, and has a characteristic that the charge state changes depending on pH.

（式中、ＭはＨまたはＬｉ，、Ｎａ、Ｋ等のアルカリ金属、有機塩基を表し、ｎは１０〜１６の整数を表す。）」

(In the formula, M represents H or an alkali metal such as Li, Na, K, or an organic base, and n represents an integer of 10 to 16). "

Examples thereof include, but are not limited to, decyl diaminoethyl glycine, dodecyl diaminoethyl glycine, tetradecyl diaminoethyl glycine, hexadecyl diaminoethyl glycine, and the like. Two or more types can be used in combination.
Among them, it is more preferable in terms of image density to use an alkyl group having 12 to 14 carbon atoms.
The compound of the general formula (I) is characterized by a large number of cationic sites, unlike the alkylaminobetaine which is an amphoteric surfactant often used elsewhere, and is considered to have different charge fluctuation regions depending on pH.

The acidic carbon black used in the present invention is an acid having a functional group showing acidity on the surface due to incomplete combustion or oxidation treatment in general carbon black production, and having an acidic pH of 5 or less according to the measurement method of DIN EN ISO 787/9. It is carbon black which shows.
Examples of commercially available products include the following.
Mitsubishi Chemical Corporation # 2650, # 2350, # 1000, # 970, MA77, MA7, MA8, MA11, MA100, MA100R, MA100S, MA230, MA220, Degussa FW200, FW2, FW2V, FW1, FW18, S170, S160 , Special Black6, Special Black5, Special Black4, Special Black4A, Special Black550, Special Black350, Special Black250, Special Black100, PRINTEX150T, PRINTEX U, PRINTEX V, PRINTEX140U, PRINTEX140V, NEROX305, NEROX505, NEROX605, NERO 500, NEROX600, NIPEX150, NIPEX160IQ, NIPEX180IQ, NIPEX170IQ, MONARCH 1000 manufactured by Cabot Corp., MOGUL-L, but REGAL 400R and the like without limitation.

  The pigment dispersion pH and the ink pH are measured with a pH meter in a glass electrode, and in the present invention, are values measured with a pH meter MP220 manufactured by Mettler.

  The pH adjuster is not particularly limited as long as it can be adjusted to the pH range, and can be appropriately selected as necessary. For example, alkali metal such as lithium hydroxide, sodium hydroxide, potassium hydroxide, etc. Hydroxide, ammonium hydroxide, quaternary ammonium hydroxide, quaternary phosphonium hydroxide, alkali metal carbonates such as lithium carbonate, sodium carbonate, calcium carbonate, ammonia, diethanolamine, triethanolamine, etc. An organic amine etc. are mentioned.

  In particular, sodium hydroxide is preferable for adjusting the pH of the carbon black dispersion, and 2-amino-2-ethyl-1,3-propanediol is preferable for adjusting the pH of the ink.

The feature of the present invention is that the carbon black dispersion used exclusively for the black ink for ink jet employs acidic carbon black as the carbon black, and uses the compound represented by the general formula (I) as the dispersant. Then, the compound represented by the general formula (I) is adsorbed on the surface of the carbon black by being dispersed. It is highly preferred to disperse the pH under conditions of 9.5-12.
The pigment dispersion can be mixed with an aqueous liquid medium containing water and a penetrant to prepare the ink for inkjet recording of the present invention. This ink is very preferably prepared to have a pH of 9.5 to 11.

In general, amphoteric surfactants typified by alkylamine oxides and alkylaminobetaines are used in inkjet inks to adjust the surface tension of inks and to be used as ink additives as foam control agents. To do. And structurally, it has both a cationic site | part and an anionic site | part, and has the characteristic that an electric charge state changes with pH.
Even if the aqueous solution of the double-sided activator itself changes in pH, the charge state may fluctuate and characteristics such as the ability to adjust the surface tension may fluctuate, but aggregation and sedimentation do not occur.

However, when the amphoteric activator is adsorbed on the surface of carbon black and its charge repulsion is used for carbon black dispersion stability, the charge stability fluctuates due to pH fluctuations. It is thought that aggregation occurs.
In principle, if a carbon black dispersion dispersed using such an amphoteric surfactant is used for ink-jet ink, the ink is dispersed and stable in a certain pH region, but is discharged from a printer and recorded. When landing on paper, which is a medium, it is considered that the alkali component penetrates into the paper and the pH fluctuates on the acidic side, whereby carbon black aggregates and remains on the paper surface, thereby obtaining a high image density.

  Based on the above idea, double-sided surfactants were investigated as dispersants, but the pH at which the charge state of most amphoteric surfactants fluctuates is near neutral, and even if they are used for ink and land on paper, the pH of the paper In the neutral region, no effect of improving the image density was observed.

  As a result of further investigation, when the compound represented by the general formula (I) is used as a carbon black dispersant, the carbon black can be well dispersed only when the dispersion pH is 9.5 to 12, and the pH is 9 or less. In the case of, it was found that it was not dispersible (carbon black aggregated).

However, it has been found that even when a dispersion using a compound represented by the general formula (I) as a carbon black dispersant is simply used in an inkjet ink, the image density cannot always be improved.
The cause is considered to be that the pH variation when the ink landed on the paper was not so large, and the pH range of the ink did not reach the aggregation pH range of the carbon black dispersion.

As a result of further intensive studies, it has been found that the above can be solved by using acidic carbon black as carbon black.
This is considered to be because acidic carbon black promotes the pH variation of the ink to the acidic side when the ink reaches the paper and the alkaline component penetrates the paper.

  Furthermore, the effect is further improved by setting the ink pH to 9.5-11.

  In short, the present invention uses a compound represented by the general formula (I) as a dispersant for acidic carbon black, and disperses the dispersion under conditions of 9.5 to 12, so that the pH range is 9. If it is 5 or more, the carbon black particle size is small and there is dispersion stability, but if the pH is 9 or less, the dispersion stability is lost and aggregation occurs. Through such a process, it became possible to produce a good carbon black dispersion of the present invention.

  Moreover, although the above-described carbon black dispersion is used for inkjet ink and the ink pH is adjusted to 9.5-11, the ink liquid is stable, but even with slight pH fluctuations after the ink has landed on the paper, acidic carbon It is considered that carbon black can be aggregated because black promotes ink pH fluctuation, and a high image density can be realized.

  In the “pigment dispersion” and “ink jet recording ink” of the present invention, the amount of the compound represented by the general formula (I) needs to be appropriately selected depending on the type of carbon black. On the other hand, 0.005 to 5 parts by weight is preferable. Even if 0.01 to 2 parts by weight with respect to 1 part by weight of the pigment, a uniform dispersion having no practical problem can be obtained, but the most preferable is 0.02 to 0.5 parts by weight with respect to 1 part by weight of the pigment. When the content is in the range of 0.01 to 2 parts by weight, the dispersibility of the pigment is improved and the aging stability of the pigment dispersion and the ink tends to be improved. Particularly in the range of 0.02 to 0.5 parts by weight, the temporal stability of the pigment dispersion and the ink is most improved.

In addition, it can be used in combination with other dispersants as long as the above effects are not impaired. However, as described above, it is necessary to pay attention because the image density effect cannot be obtained even if the compound represented by the general formula (I) is added after carbon black is dispersed with another dispersant.
As other dispersants, various surfactants such as anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, and polymer type dispersants are used in combination as long as the image density effect is not impaired. It is possible to use.

  Examples of the anionic surfactant include alkyl sulfocarboxylates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, N-acyl amino acids and salts thereof, N-acyl methyl taurate, alkyl sulfate polyoxy Alkyl ether sulfate, alkyl sulfate polyoxyethylene alkyl ether phosphate, rosin acid soap, castor oil sulfate ester salt, lauryl alcohol sulfate ester salt, alkylphenol type phosphate ester, naphthalene sulfonate formalin condensate, alkyl type phosphate ester, Examples include alkylallylsulfone hydrochloride, diethylsulfosuccinate, and dioctylsulfosuccinate of diethylhexylsulfosuccinate.

Examples of the cationic surfactant include 2-vinylpyridine derivatives and poly-4-vinylpyridine derivatives.
Examples of amphoteric surfactants include lauryldimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, polyoctylpolyaminoethylglycine and others Examples include imidazoline derivatives.

Nonionic surfactants include the following.
Ether systems such as polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, polyoxyethylene alkyl ether and polyoxyallylalkyl alkyl ether;
Polyoxyethylene oleic acid, polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate and polyoxyethylene stearate Ester systems such as
2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol and 3,5-dimethyl-1-hexyn-3-ol Acetylene glycol system such as

  The dispersion medium of the pigment dispersion desirably contains water, but various organic solvents may be used in combination as necessary. For example, as water-soluble organic solvents, alcohols such as methanol, ethanol, 1-propanol and 2-propanol, polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol and glycerin, N-methylpyrrolidone, 2-pyrrolidone and the like Pyrrolidone derivatives, ketones such as acetone and methyl ethyl ketone, alkanolamines such as monoethanolamine, diethanolamine, and triethanolamine.

In the present invention, it is also possible to use the ink and a pretreatment liquid that causes aggregation / thickening action.
If an image is formed with the ink of the present invention after the surface of the recording medium is processed with the pretreatment liquid, an effect on the image density is further observed.

Although the pretreatment liquid of the present invention contains the following polyvalent metal salt, the pretreatment liquid is preferably one that exhibits acidity.
Examples of the following multivalent ions include alkali metal ions, divalent metal ions such as Ca, Cu, Ni, Mg, Zn, and Ba, and trivalent metal ions such as Al, Fe, and Cr.
As anions constituting the water-soluble metal salt, organic acid ions such as citric acid, tartaric acid, acetic acid, lactic acid, oxalic acid, carbonic acid, fumaric acid, salicylic acid, benzoic acid, OH, Cl, NO ₃ , I, Br, Inorganic ions of ClO _{3 and} the like can be mentioned. Moreover, aluminum potassium sulfate, aluminum sulfate, etc. are mentioned.
The water-soluble metal salt is preferably added in an amount of 1% to 10% with respect to the pretreatment agent.

  As necessary, the pretreatment liquid may be a resin, a wetting agent, a surfactant, a penetrating agent, a pH adjuster, an antiseptic / antifungal agent, a chelating reagent, an antirust agent, an antioxidant, an ultraviolet absorber, an oxygen absorber, Various additives such as a light stabilizer can be blended. Since these additives are the same as those of the pigment dispersion, details will be described later.

Further, a water-soluble metal salt (CaCl ₂ or the like), an alkyleneamine (long-chain alkyl isocyanate-modified polyethyleneimine or the like), an acid (lactic acid or maleic acid), or the like can be used as the ink aggregating agent.

  As a method for treating the surface of the recording medium with the pretreatment liquid, a known method such as an ink jet method, spraying, roll coating, or wire-bar can be used.

In addition to black ink, color ink / colorless ink can also be used in the inkjet recording system of the present invention.
Examples of the magenta pigment include Pigment Red 5, 7, 12, 48 (Ca), 48 (Mn), 57 (Ca), 57: 1, 112, 122, 123, 168, 184, 202, Pigment Violet 19, and the like. It is done.
Examples of the cyan pigment include pigment blue 1, 2, 3, 15, 15: 3, 15: 4, 16, 22, 60, and bat blue 4, 60.
Examples of the yellow pigment include pigment yellow 1, 2, 3, 12, 13, 14, 16, 17, 73, 74, 75, 83, 93, 95, 97, 98, 114, 120, 128, 129, 138, 150. 151, 154, 155, 180 and the like.
By using Pigment Yellow 74 as the yellow pigment, Pigment Red 122 and Pigment Violet 19 as the magenta pigment, and Pigment Blue 15 as the cyan pigment, it is possible to obtain a balanced ink with excellent color tone and light resistance.
The pigment concentration in the pigment dispersion or pigment ink is preferably 0.1 to 50% by weight, particularly preferably 0.1 to 30% by weight.
These can be used by dispersing with the above-described dispersant or the like.

For pigment dispersions and inks, resins, wetting agents, surfactants, penetrants, pH adjusters, antiseptic / antifungal agents, chelating reagents, rust preventives, antioxidants, UV absorbers, oxygen absorbers as necessary Various additives such as an agent and a light stabilizer can be blended.
Examples of the wetting agent are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include polyhydric alcohols, polyhydric alcohol alkyl ethers, polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides. , Amines, sulfur-containing compounds, propylene carbonate, ethylene carbonate, other wetting agents and the like. These may be used alone or in combination of two or more.

  Examples of polyhydric alcohols include glycerin, diethylene glycol, 1,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, propylene glycol, dipropylene glycol, trimethylolpropane, trimethylolethane, Ethylene glycol, tripropylene glycol, tetraethylene glycol, hexylene glycol, polyethylene glycol, polypropylene glycol, 1,5-pentanediol, 1,6-hexanediol, glycerol, 1,2,6-hexanetriol, 1,2, Examples include 4-butanetriol, 1,2,3-butanetriol, and petriol.

  Examples of the polyhydric alcohol alkyl ethers include 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, and the like. It is done.

  Examples of polyhydric alcohol aryl ethers include ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.

Examples of the nitrogen-containing heterocyclic compound include 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethylimidazolidinone, ε-caprolactam, γ-butyrolactone, and the like. Is mentioned.
Examples of amides include formamide, N-methylformamide, N, N-dimethylformamide, and the like.
Examples of amines include monoethanolamine, diethanolamine, triethanolamine, monoethylamine, diethylamine, triethylamine, and the like.
Examples of the sulfur-containing compounds include dimethyl sulfoxide, sulfolane, thiodiethanol, and the like.

Other humectants are preferably sugars. Examples of saccharides include monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides), polysaccharides, and the like. Specific examples include glucose, mannose, fructose, ribose, xylose, arabinose, galactose, maltose, cellobiose, lactose, sucrose, trehalose, maltotriose, and the like. Here, the polysaccharide means a saccharide in a broad sense, and is used to include a substance that exists widely in nature such as α-cyclodextrin and cellulose. Examples of derivatives of these saccharides include reducing sugars of the aforementioned saccharides (for example, sugar alcohols represented by the general formula: HOCH ₂ (CHOH) nCH ₂ OH (n = 2 to 5)), oxidized sugars ( For example, aldonic acid, uronic acid, etc.), amino acids, thioic acid and the like. Among these, sugar alcohols are preferable, and specific examples include maltitol and sorbit.
Among the above wetting agents, glycerin, diethylene glycol, triethylene glycol, 1,3-butanediol, 3-methyl-1,3-butanediol, 2-pyrrolidone, N-methyl from the viewpoint of storage stability and ejection stability. 2-pyrrolidone is particularly preferred.

The blending ratio of the pigment and the wetting agent has a great influence on the stability of ink ejection from the head. If the blending amount of the wetting agent is small even though the pigment solid content is high, the evaporation of water near the ink meniscus of the nozzle may progress, resulting in ejection failure.
The content of the wetting agent in the ink is about 20 to 35% by weight, but more preferably 22.5 to 32.5% by weight. Within this range, the results of ink drying, storage test, reliability test and the like are very good. If the content is less than 20% by weight, the ink may easily dry on the nozzle surface, resulting in ejection failure. If the content exceeds 35% by weight, the dryness on the paper surface is poor and the character quality on plain paper is poor. May decrease.

As the surfactant, those having a low surface tension and a high leveling property are used, depending on the type of pigment and the combination with the wetting agent. For example, fluorine-based surfactants and silicone-based surfactants can be mentioned, and fluorine-based surfactants are preferable.
As the fluorine-based surfactant, those having 2 to 16 carbon atoms substituted by fluorine are preferable, and those having 4 to 16 carbon atoms are more preferable. When the fluorine-substituted carbon number is less than 2, the effect of fluorine may not be obtained, and when it exceeds 16, problems such as ink storage stability may occur.
Examples of fluorosurfactants include perfluoroalkyl sulfonic acid compounds, perfluoroalkyl carboxylic acid compounds, perfluoroalkyl phosphate ester compounds, perfluoroalkyl ethylene oxide adducts, and perfluoroalkyl ether groups in the side chain. And polyoxyalkylene ether polymer compounds. Among these, a polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain is particularly preferable because of its low foaming property.

Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid, perfluoroalkyl sulfonate, and the like.
Examples of the perfluoroalkyl carboxylic acid compound include perfluoroalkyl carboxylic acid and perfluoroalkyl carboxylate.
Examples of the perfluoroalkyl phosphate compound include perfluoroalkyl phosphate esters, perfluoroalkyl phosphate salts, and the like.
The polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain includes a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain, and a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain. And a salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain.
As counter ions of salts in these fluorosurfactants, Li, Na, K, NH ₄ , NH ₃ CH ₂ CH ₂ OH, NH ₂ (CH ₂ CH ₂ OH) ₂ , NH (CH ₂ CH ₂ OH) ₃ etc. are mentioned.

  As a fluorine-type surfactant, what was synthesize | combined suitably may be used, or a commercial item may be used. Examples of commercially available products include DuPont FS-300, Neos FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW, and OM-nova PF-151N. Is mentioned.

  The silicone-based surfactant is not particularly limited and may be appropriately selected depending on the purpose, and those that do not decompose even at high pH are preferable. For example, side-chain modified polydimethylsiloxane, both-end modified polydimethylsiloxane, piece Examples include terminal-modified polydimethylsiloxane and side-chain both-end-modified polydimethylsiloxane, and those having a polyoxyethylene group or polyoxyethylene polyoxypropylene group as a modifying group exhibit good properties as an aqueous surfactant. preferable.

As a silicone type surfactant, you may use what was synthesize | combined suitably or may use a commercial item. Commercially available products can be easily obtained from, for example, Big Chemie, Shin-Etsu Silicone, Toray Dow Corning Silicone.
The content of the surfactant in the ink is preferably 0.01 to 3.0% by weight, and more preferably 0.5 to 2% by weight. If the content is less than 0.01% by weight, the effect of adding the surfactant may be lost. If the content exceeds 3.0% by weight, the permeability to the recording medium becomes higher than necessary, and the image density decreases. And strikethrough may occur.

The penetrant preferably contains at least one polyol compound having a solubility in water at 20 ° C. of 0.2 to 5.0% by weight. Examples of such a polyol compound include 2-ethyl-2-methyl-1,3-propanediol, 3,3-dimethyl-1,2-butanediol, and 2,2-diethyl-1,3-propanediol. 2-methyl-2-propyl-1,3-propanediol, 2,4-dimethyl-2,4-pentanediol, 2,5-dimethyl-2,5-hexanediol, 5-hexene-1,2- Examples thereof include aliphatic diols such as diol and 2-ethyl-1,3-hexanediol.
Among these, 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol are particularly preferable.

  Other penetrants that can be used in combination are not particularly limited as long as they can be dissolved in the ink and adjusted to the desired physical properties, and can be appropriately selected according to the purpose. For example, diethylene glycol monophenyl ether, ethylene Examples thereof include alkyl and aryl ethers of polyhydric alcohols such as glycol monophenyl ether, ethylene glycol monoallyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether and tetraethylene glycol chlorophenyl ether, and lower alcohols such as ethanol.

  The content of the penetrant in the ink is preferably 0.1 to 4.0% by weight. If the content is less than 0.1% by weight, quick-drying may not be obtained and a blurred image may be obtained. If the content exceeds 4.0% by weight, the dispersion stability of the colorant is impaired, and the nozzle is easily clogged. Or the permeability to the recording medium is unnecessarily high, and the image density may be lowered or the image may be broken through.

The pH adjuster is not particularly limited as long as it can adjust the pH to 7 to 11 without adversely affecting the ink to be prepared, and can be appropriately selected according to the purpose. And alkali metal hydroxides, ammonium hydroxides, phosphonium hydroxides, alkali metal carbonates, and the like. When the pH is less than 7 or exceeds 11, the amount of the ink-jet head or ink supply unit that melts out increases, and problems such as ink deterioration, leakage, and ejection failure may occur.
Examples of alcohol amines include diethanolamine, triethanolamine, 2-amino-2-ethyl-1,3-propanediol, and the like.
Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, and potassium hydroxide.
Examples of the ammonium hydroxide include ammonium hydroxide, quaternary ammonium hydroxide, quaternary phosphonium hydroxide, and the like.
Examples of the alkali metal carbonate include lithium carbonate, sodium carbonate, and potassium carbonate.

Examples of the antiseptic / antifungal agent include sodium dehydroacetate, sodium sorbate, 2-pyridinethiol-1-oxide sodium, sodium benzoate, sodium pentachlorophenol, and the like.
Examples of the chelating reagent include sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, sodium uramil diacetate, and the like.
Examples of the rust preventive include acidic sulfite, sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, dicyclohexylammonium nitrite and the like.

Examples of the antioxidant include phenol-based antioxidants (including hindered phenol-based antioxidants), amine-based antioxidants, sulfur-based antioxidants, phosphorus-based antioxidants, and the like.
Examples of phenolic antioxidants (including hindered phenolic antioxidants) include butylated hydroxyanisole, 2,6-di-tert-butyl-4-ethylphenol, stearyl-β- (3,5- Di-tert-butyl-4-hydroxyphenyl) propionate, 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2′-methylenebis (4-ethyl-6-tert-butylphenol), 4 , 4′-butylidenebis (3-methyl-6-tert-butylphenol), 3,9-bis [1,1-dimethyl-2- [β- (3-tert-butyl-4-hydroxy-5-methylphenyl) Propionyloxy] ethyl] -2,4,8,10-tetrixaspiro [5,5] undecane, 1,1,3-tris (2-Methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene And tetrakis [methylene-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate] methane.

  Examples of amine-based antioxidants include phenyl-β-naphthylamine, α-naphthylamine, N, N′-di-sec-butyl-p-phenylenediamine, phenothiazine, N, N′-diphenyl-p-phenylenediamine, 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butylphenol, 2,4-dimethyl-6-tert-butyl-phenol, butylhydroxyanisole, 2,2′-methylenebis (4 -Methyl-6-tert-butylphenol), 4,4'-butylidenebis (3-methyl-6-tert-butylphenol), 4,4'-thiobis (3-methyl-6-tert-butylphenol), tetrakis [methylene- 3 (3,5-di-tert-butyl-4-dihydroxyphenyl) propionate And methane, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, and the like.

Examples of the sulfur-based antioxidant include dilauryl-3,3′-thiodipropionate, distearyl thiodipropionate, lauryl stearyl thiodipropionate, dimyristyl-3,3′-thiodipropionate, distearyl. -Β, β'-thiodipropionate, 2-mercaptobenzimidazole, dilauryl sulfide and the like.
Examples of the phosphorus antioxidant include triphenyl phosphite, octadecyl phosphite, triisodecyl phosphite, trilauryl trithiophosphite, and trinonylphenyl phosphite.

Examples of the ultraviolet absorber include a benzophenone ultraviolet absorber, a benzotriazole ultraviolet absorber, a salicylate ultraviolet absorber, a cyanoacrylate ultraviolet absorber, and a nickel complex ultraviolet absorber.
Examples of benzophenone-based ultraviolet absorbers include 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-n-dodecyloxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone and the like can be mentioned.
Examples of the benzotriazole ultraviolet absorber include 2- (2′-hydroxy-5′-tert-octylphenyl) benzotriazole, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- ( 2'-hydroxy-4'-octoxyphenyl) benzotriazole, 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole and the like.
Examples of salicylate-based ultraviolet absorbers include phenyl salicylate, p-tert-butylphenyl salicylate, p-octylphenyl salicylate, and the like.
Examples of the cyanoacrylate ultraviolet absorber include ethyl-2-cyano-3,3′-diphenyl acrylate, methyl-2-cyano-3-methyl-3- (p-methoxyphenyl) acrylate, and butyl-2- And cyano-3-methyl-3- (p-methoxyphenyl) acrylate.
Examples of the nickel complex ultraviolet absorber include nickel bis (octylphenyl) sulfide, 2,2′-thiobis (4-tert-octylferrate) -n-butylamine nickel (II), 2,2′-thiobis ( 4-tert-octylferrate) -2-ethylhexylamine nickel (II), 2,2′-thiobis (4-tert-octylferrate) triethanolamine nickel (II), and the like.

The pigment dispersion in the present invention is a known method, for example, a pigment dispersion raw material such as pigment, water, water-soluble organic solvent, surfactant, sand mill, ball mill, roll mill, bead mill, nanomizer, homogenizer, ultrasonic disperser, etc. Is sufficiently dispersed using a filter, coarse particles are filtered with a filter, a centrifugal separator or the like, and degassed as necessary.
In the present invention, the solid content concentration of the carbon black of the pigment dispersion may be set conveniently depending on the type of pigment, the use of the ink, and the amount of pigment contained in the ink, and is usually in the range of 0.1 wt% to 30 wt%. Is set.
The pigment solid content of the pigment dispersion necessary for allowing the ink to contain the pigment amount optimal for the image density of the ink jet is 10% by weight to 25% by weight, preferably 15% by weight to 20% by weight.
As for the particle diameter of the carbon black after dispersion, the volume average particle diameter D50 is preferably 50 nm to 500 nm. If it is 50 nm or less, if the rubbing resistance of the image at the time of image formation exceeds 500 nm, the ink ejection from the ink jet head tends to deteriorate.

The ink for ink jet recording containing the pigment used in the present invention may be prepared by a known method such as a pigment dispersion, water, a water-soluble organic solvent, a surfactant, a sand mill, a ball mill, a roll mill, a bead mill, a nanomizer, a homogenizer, It is obtained by stirring and mixing using a sonic disperser or the like, filtering coarse particles with a filter, a centrifugal separator or the like, and deaeration as necessary.
The concentration of the pigment in the ink is preferably 1 to 20% by weight with respect to the total amount of the ink. If it is less than 1% by weight, the image density is low, so that the printing is not clear. If it is more than 20% by weight, not only the viscosity of the ink tends to be high, but also nozzle clogging tends to occur.
The content of the water-soluble organic solvent is 50% by weight or less, preferably 5 to 40% by weight, more preferably 10 to 35% by weight, based on the total amount of the ink.
In addition, the ink may be blended with additives similar to those described in the additives for the pigment dispersion, if necessary.

The pretreatment liquid and ink jet recording ink can be accommodated in a container and used as a cartridge.
Further, the set of the pretreatment liquid of the present invention and the ink for ink jet recording can be accommodated in a container to form a cartridge, and the image can be obtained by printing on a recording medium using an ink jet recording apparatus equipped with the cartridge.
As a printing method, there are a continuous jet type and an on-demand type, and examples of the on-demand type include a piezo method, a thermal method, and an electrostatic method.

An example of the image forming method of the present invention and an ink jet recording apparatus for carrying out the method will be described with reference to the drawings.
The ink jet recording apparatus of FIG. 1 is equipped with a cartridge (20) containing pretreatment liquid and ink, and the pretreatment liquid and ink are supplied from this cartridge to the recording head. Here, the cartridge (20) is mounted in a state where the pretreatment liquid and the ink for each color are separated.
The recording head (1) is mounted on a carriage (18) and moved while being guided by guide shafts (21) and (22) by a timing belt (23) driven by a main scanning motor (24). On the other hand, the recording material is placed at a position facing the recording head by the platen.

FIG. 2 is an enlarged view of a nozzle surface of an example of the recording head. A nozzle (31) for discharging the pretreatment liquid is provided in the vertical direction, and yellow ink, magenta ink, cyan ink, and black ink are discharged from the nozzles (32), (33), (34), and (35), respectively.
Further, as shown in FIG. 3, it is possible to arrange all the nozzles of the recording head in the horizontal direction. The nozzles (36) and (41) in the figure are pretreatment liquid discharge nozzles, and yellow ink, magenta ink, cyan ink, and black ink are discharged from the nozzles (37), (38), (39), and (40), respectively. Is done. In the recording head of this aspect, since the pretreatment liquid discharge nozzles are provided at the left and right ends, printing is possible in both the forward path and the backward path in which the recording head reciprocates on the carriage. In other words, it is possible to attach the pretreatment liquid first in both the forward pass and the return pass and then attach the color ink from the top, or vice versa, and the difference in image density due to the difference in the moving direction of the recording head. Does not occur.
The ink jet recording apparatus can be replenished with pretreatment liquid and ink by replacing the cartridge. Further, this cartridge may be integrated with the recording head.

4 and 5 show cartridges that can store the pretreatment liquid and ink. This cartridge can store both the pretreatment liquid and the ink.
Most preferably, the ink and the pretreatment liquid are discharged from the recording head in the same location. However, in the present invention, for example, the pretreatment liquid is thinned out and applied, and the ink is overlaid on the pretreatment liquid enlarged by bleeding or the like, or the pretreatment liquid is applied only to the contour portion of the image, and the ink is formed thereon. A sufficient effect can be obtained by overlapping a part of the above.

EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated further more concretely, this invention is not limited by these Examples.
In Examples and Comparative Examples, pigment dispersions were prepared and inks were prepared using the pigment dispersions. Moreover, the pre-processing liquid was created, respectively. In the examples, “parts” and “%” are based on weight.

<Preparation of pigment dispersion of Example 1>
After pre-mixing materials with the following formulation, disperse for 5 minutes at a peripheral speed of 10 m / s and a liquid temperature of 10 ° C. using 0.3 mm zirconia beads with a disk-type bead mill (KDL type batch type manufactured by Shinmaru Enterprises). did. Subsequently, coarse particles were separated by a centrifugal separator (Model-3600, manufactured by Kubota Corporation) to obtain a carbon black pigment dispersion 1 having an average particle diameter of about 120 nm and a standard deviation of 51.2 nm.

(Pigment dispersion formulation of Example 1)
・ Carbon black (manufactured by degussa: gas black, NIPEX150)
20.0 parts · Dodecibis- (aminoethyl) glycine sodium aqueous solution (solid content 30%) 8.3 parts · NaOH aqueous solution (solid content 20%) 1.4 parts · Distilled water 70.3 parts

<Creation of Ink of Example 1>
Ink 1 was prepared by mixing and stirring materials having the following formulation for 30 minutes.
(Ink formulation of Example 1)
-Pigment dispersion of Example 1 (pigment concentration 20%) 40.0 parts-Glycerol 5.5 parts-1,3-butanediol 16.5 parts-2-ethyl-1,3-hexanediol 2.0 parts Fluorosurfactant (solid content 40%) 2.5 parts (DuPont: Zonyl FS-300)
Fluoroethylene / vinyl ether alternating copolymer (solid content 50%) 6.0 parts (Asahi Glass Co., Ltd .: Lumiflon FE4300, average particle diameter 150 nm, MFT 30 ° C. or less)
・ 1.5 parts of 2-amino-2-ethyl-1,3-propanediol aqueous solution (solid content 40%) ・ 26.0 parts of distilled water

(Pigment dispersion)
In place of the dispersant dodecyldiaminoethylglycine of Example 1, tetradecyldiaminoethylglycine was used, and the parts by weight of the NaOH aqueous solution described in Example 1 (pigment dispersion formulation of Example 1) were changed to the dispersion described in Table 1. The pigment dispersion of Example 2 was prepared in the same manner as in Example 1 except that distilled water was adjusted so that the total pH was adjusted to 100 parts by weight.
(Ink liquid)
In Example 1 (ink formulation of Example 1), the pigment dispersion of Example 2 was used instead of the pigment dispersion of Example 1, and an aqueous 2-amino-2-ethyl-1,3-propanediol solution was used. The ink liquid of Example 2 was obtained in the same manner as in Example 1 except that distilled water was adjusted so that the parts by weight were adjusted to the ink pH shown in Table 1, and the total weight part was 100 parts by weight accordingly. It was.

(Pigment dispersion)
In place of the dispersant dodecyldiaminoethylglycine of Example 1, decyldiaminoethylglycine was used, and the parts by weight of the NaOH aqueous solution described in Example 1 (pigment dispersion formulation of Example 1) were changed to those of the dispersion described in Table 1. The pigment dispersion of Example 3 was prepared in the same manner as in Example 1 except that the distilled water was adjusted so that the pH was adjusted to 100 parts by weight.
(Ink liquid)
In Example 1 (ink formulation of Example 1), the pigment dispersion of Example 3 was used instead of the pigment dispersion of Example 1, and the aqueous 2-amino-2-ethyl-1,3-propanediol solution was used. The ink liquid of Example 3 was obtained in the same manner as in Example 1 except that distilled water was adjusted so that the parts by weight were adjusted to the ink pH shown in Table 1, and the total part by weight was 100 parts by weight. It was.

(Pigment dispersion)
Hexadecyldiaminoethylglycine was used in place of the dispersant dodecyldiaminoethylglycine of Example 1, and the parts by weight of the NaOH aqueous solution described in Example 1 (pigment dispersion formulation of Example 1) were changed to the dispersion described in Table 1. A pigment dispersion of Example 4 was prepared in the same manner as in Example 1 except that distilled water was adjusted so that the total pH was adjusted to 100 parts by weight.
(Ink liquid)
In Example 1 (ink formulation of Example 1), the pigment dispersion of Example 4 was used instead of the pigment dispersion of Example 1, and the aqueous 2-amino-2-ethyl-1,3-propanediol solution was used. The ink liquid of Example 4 was obtained in the same manner as in Example 1 except that the weight part was adjusted to the ink pH shown in Table 1 and distilled water was adjusted so that the total weight part was 100 parts by weight. It was.

(Pigment dispersion)
The weight part of the NaOH aqueous solution described in Example 1 (pigment dispersion formulation of Example 1) is adjusted to the pH of the dispersion described in Table 1, and accordingly, the total weight part is 100 parts by weight. A pigment dispersion of Example 5 was prepared in the same manner as in Example 1 except that distilled water was adjusted.
(Ink liquid)
In Example 1 (ink formulation of Example 1), the pigment dispersion of Example 5 was used instead of the pigment dispersion of Example 1, and an aqueous 2-amino-2-ethyl-1,3-propanediol solution was used. The ink liquid of Example 5 was obtained in the same manner as in Example 1 except that distilled water was adjusted so that the parts by weight were adjusted to the ink pH shown in Table 1, and the total part by weight was 100 parts by weight. It was.

(Pigment dispersion)
The weight part of the NaOH aqueous solution described in Example 1 (pigment dispersion formulation of Example 1) is adjusted to the pH of the dispersion described in Table 1, and accordingly, the total weight part is 100 parts by weight. A pigment dispersion of Example 6 was prepared in the same manner as in Example 1 except that distilled water was adjusted.
(Ink liquid)
In Example 1 (ink formulation of Example 1), the pigment dispersion of Example 6 was used instead of the pigment dispersion of Example 1, and the aqueous 2-amino-2-ethyl-1,3-propanediol solution was used. The ink liquid of Example 6 was obtained in the same manner as in Example 1 except that distilled water was adjusted so that the parts by weight were adjusted to the ink pH shown in Table 1, and the total part by weight was 100 parts by weight. It was.

(Pigment dispersion)
The weight part of the NaOH aqueous solution described in Example 1 (pigment dispersion formulation of Example 1) is adjusted to the pH of the dispersion described in Table 1, and accordingly, the total weight part is 100 parts by weight. A pigment dispersion of Example 7 was prepared in the same manner as in Example 1 except that distilled water was adjusted.
(Ink liquid)
In Example 1 (ink formulation of Example 1), the pigment dispersion of Example 7 was used instead of the pigment dispersion of Example 1, and the aqueous 2-amino-2-ethyl-1,3-propanediol solution was used. The ink liquid of Example 7 was obtained in the same manner as in Example 1 except that distilled water was adjusted so that the parts by weight were adjusted to the ink pH shown in Table 1, and the total weight part was 100 parts by weight accordingly. It was.

(Pigment dispersion)
The weight part of the NaOH aqueous solution described in Example 1 (pigment dispersion formulation of Example 1) is adjusted to the pH of the dispersion described in Table 1, and accordingly, the total weight part is 100 parts by weight. A pigment dispersion of Example 8 was prepared in the same manner as in Example 1 except that distilled water was adjusted.
(Ink liquid)
In Example 1 (ink formulation of Example 1), the pigment dispersion of Example 8 was used instead of the pigment dispersion of Example 1, and the aqueous 2-amino-2-ethyl-1,3-propanediol solution was used. The ink liquid of Example 8 was obtained in the same manner as in Example 1 except that distilled water was adjusted so that the parts by weight were adjusted to the ink pH shown in Table 1, and the total weight part was 100 parts by weight accordingly. It was.

(Pigment dispersion)
The weight part of the NaOH aqueous solution described in Example 1 (pigment dispersion formulation of Example 1) is adjusted to the pH of the dispersion described in Table 1, and accordingly, the total weight part is 100 parts by weight. A pigment dispersion of Example 9 was prepared in the same manner as in Example 1 except that distilled water was adjusted.
(Ink liquid)
In Example 1 (ink formulation of Example 1), the pigment dispersion of Example 9 was used in place of the pigment dispersion of Example 1, and an aqueous 2-amino-2-ethyl-1,3-propanediol solution was used. The ink liquid of Example 9 was obtained in the same manner as in Example 1 except that distilled water was adjusted so that the parts by weight were adjusted to the ink pH shown in Table 1, and the total weight part was 100 parts by weight accordingly. It was.

(Pigment dispersion)
Carbon black (manufactured by Degussa: Gas Black, NIPEX 150) described in Example 1 (pigment dispersion formulation of Example 1) was changed to carbon black (manufactured by Degussa: Gas Black, FW200), and the weight part of the NaOH aqueous solution was A pigment dispersion of Example 10 was prepared in the same manner as in Example 1 except that the distilled water was adjusted so that the dispersion pH shown in Table 1 was adjusted to 100 parts by weight. .
(Ink liquid)
In place of the pigment dispersion of Example 1 described in Example 1 (ink formulation of Example 1), the pigment dispersion of Example 10 was used, and an aqueous 2-amino-2-ethyl-1,3-propanediol solution was used. The ink of Example 10 was adjusted in the same manner as in Example 1 except that distilled water was adjusted so that the ink pH was adjusted to the ink pH shown in Table 1 and the total weight part was 100 parts by weight. A liquid was obtained.

<Preparation of pretreatment liquid>
・ Lactic acid aqueous solution (20% by weight) 40.0 parts ・ Glycerin 5.5 parts ・ 1,3-butanediol 16.5 parts ・ 2-ethyl-1,3-hexanediol 2.0 parts ・ Fluorine surfactant (Solid content concentration 40% by weight) 2.5 parts (DuPont, Zonyl FS-300)
・ 33.5 parts distilled water

(Pigment dispersion) and (Ink liquid)
The pigment dispersion of Example 11 and the ink of Example 11 were prepared in the same manner as in Example 1.
These results and the evaluation results for use in printing are summarized in Table 1.

[Comparative Example 1]
The parts by weight of the aqueous NaOH solution described in Example 1 (pigment dispersion formulation of Example 1) are adjusted to the dispersion pH of Comparative Example 1 described in Table 2, and the total weight is 100 parts by weight accordingly. Thus, distilled water was adjusted and an attempt was made to prepare a pigment dispersion of Comparative Example 1, but it was in a paste state and could not be dispersed.

[Comparative Example 2]
The parts by weight of the aqueous NaOH solution described in Example 1 (pigment dispersion formulation of Example 1) are adjusted to the dispersion pH of Comparative Example 2 described in Table 2, and the total weight is 100 parts by weight accordingly. As described above, the distilled water was adjusted to prepare the pigment dispersion of Comparative Example 2, but it was in a paste state and could not be dispersed.

[Comparative Example 3]
The carbon black (made by Degussa: Gas Black, NIPEX150) described in Example 1 (pigment dispersion formulation of Example 1) was changed to carbon black (made by Degussa: NIPEX60), and the parts by weight of NaOH aqueous solution are shown in Table 2. The pigment dispersion of Comparative Example 3 was prepared in the same manner as in Example 1 except that distilled water was adjusted so that the dispersion pH of Comparative Example 3 was adjusted to 100 parts by weight. Created.

[Comparative Example 4]
(Pigment dispersion)
Instead of the aqueous solution of sodium dodecibis- (aminoethyl) glycine described in Example 1 (pigment dispersion formulation of Example 1) (solid content 30%), diethylamine salt (25%) of styrene-acrylate-methacrylic acid was replaced with 10 The pigment of Comparative Example 4 was used by adjusting the distilled water so that the weight of the aqueous NaOH solution was adjusted to the dispersion pH shown in Table 2, and the total weight was 100 parts by weight. A dispersion was created.
(Ink liquid)
In Example 1 (ink formulation of Example 1), the pigment dispersion of Comparative Example 4 was used instead of the pigment dispersion of Example 1, and a sodium dodecibis- (aminoethyl) glycine sodium solution (solid content 30%) 3.3 parts by weight were added, and the parts by weight of the 2-amino-2-ethyl-1,3-propanediol aqueous solution were adjusted to the ink pH shown in Table 2, and the total parts by weight were 100 parts by weight accordingly. An ink liquid of Comparative Example 4 was obtained in the same manner as in Example 1 except that distilled water was adjusted so that

[Comparative Example 5]
(Pigment dispersion)
Carbon black (manufactured by Degussa: Gas Black, NIPEX 150) described in Example 1 (pigment dispersion formulation of Example 1) is CI direct black (water-soluble dye), and parts by weight of NaOH aqueous solution are described in Table 2. Distilled water was adjusted so that the total dispersion was 100 parts by weight, and a dye solution of Comparative Example 5 was prepared in the same manner as in Example 1.
(Ink liquid)
The dye solution of Comparative Example 5 was used in place of the pigment dispersion of Example 1 described in Example 1 (ink formulation of Example 1), and an aqueous 2-amino-2-ethyl-1,3-propanediol solution was used. Comparison was made in the same manner as in Example 1 except that the weight part was adjusted to the ink pH of Comparative Example 5 described in Table 2, and distilled water was adjusted so that the total weight part was 100 parts by weight. The ink liquid of Example 5 was obtained.

[Comparative Example 6]
(Pigment dispersion)
Instead of the aqueous dodecibis- (aminoethyl) glycine sodium solution (solid content 30%) described in Example 1 (pigment dispersion formulation of Example 1), the dispersant of Comparative Example 6 described in Table 2 was used and NaOH was added. The pigment dispersion of Comparative Example 6 was prepared by adjusting the weight part of the aqueous solution to the dispersion pH shown in Table 2 and adjusting the distilled water so that the total weight part was 100 parts by weight.
(Ink liquid)
Instead of the aqueous dodecibis- (aminoethyl) glycine sodium solution (solid content 30%) described in Example 1 (pigment dispersion formulation of Example 1), the dispersant of Comparative Example 6 described in Table 2 was used and NaOH was added. The water part of the aqueous solution was adjusted to the ink liquid pH of Comparative Example 6 shown in Table 2, and distilled water was adjusted so that the total weight part was 100 parts by weight. Created.

[Comparative Example 7]
(Pigment dispersion)
Instead of the aqueous dodecibis- (aminoethyl) glycine sodium solution (solid content 30%) described in Example 1 (pigment dispersion formulation of Example 1), the dispersant of Comparative Example 7 described in Table 2 was used and NaOH was added. The pigment dispersion of Comparative Example 7 was prepared by adjusting the weight part of the aqueous solution to the dispersion pH of Comparative Example 7 shown in Table 2 and adjusting the distilled water so that the total weight part was 100 parts by weight. It was created.
(Ink liquid)
Instead of the aqueous dodecibis- (aminoethyl) glycine sodium solution (solid content 30%) described in Example 1 (pigment dispersion formulation of Example 1), the dispersant of Comparative Example 7 described in Table 2 was used and NaOH was added. The ink liquid of Comparative Example 7 was prepared by adjusting the weight part of the aqueous solution so that the ink liquid pH shown in Table 2 was adjusted, and adjusting the distilled water so that the total weight part was 100 parts by weight.
The storage stability of the inks of the above examples and comparative examples was evaluated by the following method, and the cartridges of the inks of the above examples and comparative examples and the pretreatment liquid (used only in Example 8) were filled in the cartridges. A printing experiment was conducted with the ink jet printer shown in FIG. 1, and the image density and storage stability were evaluated as follows. The results are shown in Tables 1 and 2.

(1) Image Density PPC paper 4024 (non-smooth paper) manufactured by Xerox Co., Ltd. was printed with the ink jet printer shown in FIG.
Larger numbers are better.

  According to the above results, the present invention can achieve a high image density even on smooth paper and non-smooth paper, and is extremely excellent in that it can provide an image forming method, an ink jet ink, a cartridge, an ink jet recording apparatus, and an image formed product. It turns out that there exists an effect.

DESCRIPTION OF SYMBOLS 1 Recording head 2 Main body housing | casing 7 Processing liquid and recording liquid common cartridge 16 Gear mechanism 17 Sub scanning motor 18 Carriage 20 Recording liquid cartridge 21 Guide shaft 22 Guide shaft 23 Timing belt 24 Main scanning motor 25 Main scanning motor 26 Main scanning motor 27 Main scanning motor 31 Nozzle for discharging processing liquid Nozzle for discharging recording liquid 33 Nozzle for discharging recording liquid Nozzle for discharging recording liquid 35 Nozzle for discharging recording liquid 36 Processing liquid is discharged Nozzle 37 Nozzle for discharging recording liquid 38 Nozzle for discharging recording liquid 39 Nozzle for discharging recording liquid 40 Nozzle for discharging recording liquid 41 Cartridge housing 42 Liquid absorber 43 Case 44 Upper lid member 45 Liquid supply port 46 Seal ring 47 Air release port 48 Groove 50 Cap 51 leakage preventing projection 53 the cap member 55 recess A space for the seal member 71 cartridge positioning portion 81 cartridge detachable protruded portion 81a cartridge for attaching and detaching the finger hook portion 82 cartridge detachable

Japanese Patent No. 4049533 JP 2009-41022 A Japanese Patent No. 3679481

Claims (8)

A pigment dispersion for preparing an inkjet recording ink, comprising pigment particles finely dispersed in a dispersion medium liquid, wherein the pigment particles are acidic carbon black, and are represented by the following general formula (I): A pigment dispersion for an inkjet recording ink, comprising at least one compound having a pH of 9.5 to 12.

(In the formula, M represents H or an alkali metal such as Li 2 , Na, or K, or an organic base, and n represents an integer of 10 to 16) Water, penetrant, and an inkjet recording ink which is adjusted to pH9.5~11 containing finely dispersed pigment ink jet recording characterized by using the pigment dispersion according to claim 1 ink. A method for producing a pigment dispersion for preparing an ink for inkjet recording, comprising pigment particles finely dispersed in a dispersion medium liquid, wherein the pigment particles are acidic carbon black, and are represented by the following general formula (I): Ink jet recording, comprising at least a step of finely dispersing the pigment particles in the dispersion medium liquid containing at least one of the compounds represented by pH of 9.5 to 12 For producing a pigment dispersion for an industrial ink.

(In the formula, M represents H or an alkali metal such as Li 2 , Na, or K, or an organic base, and n represents an integer of 10 to 16) In a method for producing an ink jet recording ink comprising pigment particles dispersed in an aqueous liquid medium, acidic carbon black pigment particles finely dispersed in the dispersion medium liquid and a compound represented by the following general formula (I): An ink liquid having a pH of 9.5 to 11 is prepared by mixing a pigment dispersion for an inkjet recording ink containing at least one kind and having a pH of 9.5 to 12 with an aqueous liquid medium containing water and a penetrant. A method for producing an ink for ink jet recording, comprising at least a step of preparing the ink.

(In the formula, M represents H or an alkali metal such as Li 2 , Na, or K, or an organic base, and n represents an integer of 10 to 16) A cartridge comprising the ink jet recording ink according to claim 2 contained in a container. An ink jet recording apparatus equipped with the cartridge according to claim 5 . An inkjet recording method for forming an image on a recording medium by ejecting and flying the recording liquid as droplets from a fine ejection port, wherein the ink for inkjet recording according to claim 2 is used as the recording liquid. An inkjet recording method characterized by the above. An image formed product printed by the ink jet recording apparatus according to claim 6 .

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