JP7115220B2 - Ink, ink container, inkjet recording apparatus, and recording method - Google Patents

Description

The present invention relates to ink, an ink container, an inkjet recording apparatus, and a recording method.

Inkjet recording has become popular because of its simpler process than other recording methods, the ease with which full-color printing can be achieved, and the ability to obtain high-resolution images even with a simple device. It is spreading from personal use to office use, commercial printing and industrial printing. In such an inkjet recording method, a water-based ink composition using a water-soluble dye as a coloring material is mainly used. The development of pigment inks using pigments from

In inkjet printing for office use, plain paper is mainly used as a recording medium, and high image density is required. In general, when pigment ink is printed on plain paper, the pigment permeates into the paper without remaining on the surface of the paper, resulting in a lower pigment density on the paper surface and a lower image density. If the pigment concentration in the ink is increased, the image density is increased, but the viscosity of the ink is increased and the ejection stability is lowered.

In order to increase the drying speed of the ink adhering to the recording medium as a countermeasure for high-speed printing, a means for accelerating drying is taken by adding a penetrating agent such as a hydrophobic solvent to the ink to allow water to permeate the recording medium. there is
Satisfying the dispersion stability in both the environment of the water solvent pigment dispersion and the hydrophobic solvent ink is required.

In addition, the water-based pigment ink used for the above-mentioned inkjet recording method and writing instruments is different from the water-based dye ink that is prepared by dissolving the dye in water, and it is necessary to stably disperse the pigment in water for a long period of time. Therefore, various pigment dispersions have been developed.

For example, in Patent Document 1, a quinacridone-based pigment (a) and an anionic group-containing organic polymer compound are disclosed as a method for producing an aqueous pigment dispersion in which a pigment is stably dispersed and a good dispersion state can be maintained even during long-term storage. A mixture containing (c), a basic compound (d), a water-soluble organic compound (e) having a solubility parameter hydrogen bond term δh of 7 to 13, and a quinacridone pigment derivative (b) is kneaded at room temperature. A method for producing an aqueous pigment dispersion is disclosed, which comprises a kneading step of producing a solid pigment dispersion and a mixing step of mixing the pigment dispersion with an aqueous medium.
In addition, Patent Document 2 includes a mixture of quinacridone compounds having a novel specific structure that is effective in achieving both good storage stability of pigment dispersions and inks, and is also effective in realizing water-based inks with excellent ejection stability. An ink is disclosed.
Furthermore, Patent Document 3 discloses an ink containing at least a pigment, wax, a water-soluble solvent, and water, wherein the water-soluble solvent includes a solvent having an SP value of 9.0 or more and 11.0 or less. The ratio (by mass) of the wax content in the solvent to the content of the solvent having an SP value of 9.0 or more and 11.0 or less is in the range of 1.0:2.5 to 1.0:25.0 is disclosed. It is described that this ink provides an image with high image density and high chroma, and is excellent in abrasion resistance of the image, as well as in storage stability and ejection stability.

SUMMARY OF THE INVENTION An object of the present invention is to provide an ink which is excellent in storage stability and capable of recording with suppressed beading.

（式中、Ｒ¹，Ｒ²，Ｒ³およびＲ⁴は水素原子、ハロゲン原子、または炭素数１～４のアルキル基を表し、同一でも異なっていてもよい。また、Ｒ⁵およびＲ⁶は炭素数１～４のアルキル基を表し、同一でも異なっていてもよい。ｍ、ｎは０～２の整数を表す。ただし、ｍ、ｎが同時に０である場合を除く。） The above problem is solved by the following invention <1>.
<1> A pigment, a quinacridone derivative represented by the following general formula (1), and a solvent A having an SP value of 9.0 or more and 11.0 or less, and the content of the solvent A is less than 10% by mass. ink.

(In the formula, R ¹ , R ² , R ³ and R ⁴ represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms, and may be the same or different. Further, R ⁵ and R ⁶ are represents an alkyl group having 1 to 4 carbon atoms, which may be the same or different, and m and n represent integers of 0 to 2, except when m and n are 0 at the same time.)

According to the present invention, it is possible to provide an ink that has excellent storage stability and enables recording with suppressed beading.

1 is a perspective view schematically showing an example of a recording apparatus according to the invention; FIG. 1 is a perspective view schematically showing an example of an ink container according to the present invention; FIG.

In the ink of the present invention, a solvent having an SP value of 9.0 or more and 11.0 or less (referred to as solvent A) is used.
When solvent A with an SP value of 9.0 or more and 11.0 or less is added to the ink as a solvent, when this ink is applied to coated paper, the amount of residual solvent in the image area on the coat layer of the coated paper is reduced. , the effect of suppressing the occurrence of beading is obtained. However, on the other hand, solvent A passes through the coat layer and reaches the cellulose layer even for recording media with low water absorbency such as coated paper, so the amount of solvent remaining in the cellulose layer is reduced even after heat drying. It is difficult to For this reason, when prints are stacked, a problem called blocking occurs in which an image is transferred to the stacked paper due to the influence of the solvent remaining in the cellulose layer. In addition, the solvent A affects the storage stability of the ink dispersed using the quinacridone derivative represented by the general formula (1). It also adversely affects ejection using an inkjet, and may cause deterioration of image quality such as color developability.
Pigments are difficult to disperse, and even if they are dispersed only with a dispersing resin, problems may arise in storage stability. However, when the quinacridone derivative represented by the general formula (1) and a water-soluble solvent having an SP value of 9.0 or more and 11.0 or less are used in combination and dispersed, storage stability and ejection stability are improved. , It is possible to obtain a highly colored ink, and by limiting the water-soluble solvent with an SP value of 9.0 or more and 11.0 or less to less than 10% by mass, beading is suppressed, drying is high, and blocking is prevented. It has been found that the ability to prevent this makes it possible to obtain an ink capable of recording with good quality.
Based on these facts, the present inventors have invented the ink of the present invention, which has excellent color developability, stability, and drying property even on coated paper used for commercial printing paper.

The present invention <1> will be described in detail below, but since the embodiment includes the following <2> to <13>, they will also be described.

<2> The ink according to <1>, wherein the content of the solvent A is 2% by mass or more and 8% by mass or less.
<3> The ink according to <1> or <2>, wherein the content of the quinacridone derivative with respect to the pigment is 1% by mass or more and 10% by mass or less.
<4> The ink according to any one of <1> to <3>, wherein the content of the quinacridone derivative in the ink is 0.01% by mass or more and 1.00% by mass or less relative to the total amount of the ink.
<5> In <1> to <4>, the ratio of the content of the quinacridone derivative in the ink to the content of the solvent A (the quinacridone derivative/the solvent A) is 0.045 or more and 0.18 or less. Ink according to any one of the above.
<6> Solvent A of <1> to <5> is at least one selected from 3-ethyl-3-hydroxymethyloxetane, isopropylideneglycerol and N,N-dimethyl-β-butoxypropionamide Ink according to any one of the above.
<7> The ink according to any one of <1> to <6>, wherein the pigment is a quinacridone pigment.
<8> The pigment contains C.I. I. Pigment Red 122, C.I. I. Pigment Violet 19, C.I. I. Pigment Red 122 and C.I. I. Pigment Violet 19 mixed crystal, or C.I. I. Pigment Red 202 and C.I. I. The ink according to any one of <1> to <7>, which is a mixed crystal of Pigment Violet 19.
<9> The ink according to any one of <1> to <8>, wherein the ink further contains a resin emulsion, and the resin emulsion comprises an acrylic resin or a urethane resin.
<10> The ink according to any one of <1> to <9>, further comprising polyethylene wax.
<11> The ink according to any one of <1> to <10>, further comprising a polyether-modified siloxane compound.
<12> An ink container containing the ink according to any one of <1> to <11>.
<13> An inkjet recording apparatus comprising the ink container according to <12> and an ejection unit for ejecting ink supplied from the ink container.
<14> A recording method comprising an ink applying step of applying the ink according to any one of <1> to <11> to a recording medium.

（式中、Ｒ¹，Ｒ²，Ｒ³およびＲ⁴は水素原子、ハロゲン原子、または炭素数１～４のアルキル基を表し、同一でも異なっていてもよい。また、Ｒ⁵およびＲ⁶は炭素数１～４のアルキル基を表し、同一でも異なっていてもよい。ｍ、ｎは０～２の整数を表す。ただし、ｍ、ｎが同時に０である場合を除く。） The ink of the present invention contains a pigment, a quinacridone derivative represented by the following general formula (1), and a solvent A having an SP value of 9.0 or more and 11.0 or less, and the content of the solvent A is 10% by mass. is less than

(In the formula, R ¹ , R ² , R ³ and R ⁴ represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms, and may be the same or different. Further, R ⁵ and R ⁶ are represents an alkyl group having 1 to 4 carbon atoms, which may be the same or different, and m and n represent integers of 0 to 2, except when m and n are 0 at the same time.)

The quinacridone derivative represented by the general formula (1) can be obtained as a quinacridone derivative mixture by the reactions shown in the following reaction formulas (1) to (2).
First, as shown in the following reaction formula (1), the quinacridone compound (A-1) and an excess amount of chlorosulfonic acid were reacted in the absence of a solvent and washed with water to replace the chlorosulfonic acid group and the sulfonic acid group. A quinacridone mixture (A-2) is obtained. Next, the above (A-2) is reacted with a dialkylamine to obtain a quinacridone derivative mixture (A-3) as shown in reaction formula (2). The quinacridone derivative mixture thus obtained by the reaction contains quinacridone derivatives where m=1 and n=1 in the general formula (1). Further, among the quinacridone derivatives represented by m=1 and n=1 in the general formula (1), there are quinacridone derivatives in which the substitution positions of the sulfonic acid group and the dialkylaminosulfonic acid group are different. Also good.
In the present invention, the quinacridone derivative represented by the general formula (1) may be a mixture, and the quinacridone derivative mixture obtained by the above method can be used.

It can be confirmed, for example, by mass spectrometry that the quinacridone derivative mixture contains the quinacridone derivative where m=1 and n=1 in the general formula (1).
For example, when the obtained quinacridone derivative mixture has a positive molecular ion peak of 556.1 ± 0.1 and a negative ion molecular ion peak of 554.1 ± 0.1 in mass spectrometry, the substitution position is Although it cannot be specified, it is confirmed that a quinacridone compound represented by the following formula where m=1 and n=1 is mixed. Further, when a positive molecular ion peak is observed at 611.2 in positive ion measurement, it is found that the quinacridone compound of m=2 and n=0 represented by the following formula is also mixed.
In mass spectrometry, the mass accuracy and resolution differ depending on the device, but the "±0.1" referred to here represents the error range of this mass spectrometry. If it falls within this range, it is assumed that the quinacridone derivative with m=1 and n=1 in the present invention has been specified.

Further, whether or not the ink contains the quinacridone derivative represented by the general formula (1) can be determined, for example, as follows.
First, the ink is separated into other ink components and a pigment component containing a quinacridone derivative. The components dissolved in the ink are separated by centrifugal sedimentation or ultrafiltration, and the components dispersed in the ink (fixing resin, etc.) Remove them by dissolving them in a solvent that dissolves them. This operation also varies depending on the materials contained in the ink. After the quinacridone derivative and the pigment are separated from other components in the ink, the quinacridone derivative represented by the general formula (1) is detected from the amount of sulfur-containing functional groups by a gas chromatograph-mass spectrometer (GC-MS). It is possible to

<Ink>
Organic solvents, water, coloring materials, resins, additives, and the like used in the ink are described below.

-coloring material-
In the present invention, a pigment is used as the coloring material. Pigments include surfactant-dispersed pigments in which pigments are dispersed with surfactants, resin-dispersed pigments in which pigments are dispersed in resin, resin-coated dispersed pigments in which pigment surfaces are coated with resin, and self-dispersed pigments in which hydrophilic groups are provided on the surface of pigments. Dispersed pigments and the like are available, but water-dispersible pigments are preferred.

The ink of the present invention is preferably a magenta ink.
Examples of the pigment include azo pigments, polycyclic pigments, dye chelates, nitro pigments, and nitroso pigments. Among these, polycyclic pigments are preferred, and quinacridone pigments are particularly preferred.
Examples of the pigment include C.I. I. Pigment Red 1, 2, 3, 5, 17, 22, 23, 31, 38, 48:2, 48:2 (Permanent Red 2B (Ca)), 48:3, 48:4, 49:1, 52: 2, 53:1, 57:1 (brilliant carmine 6B), 60:1, 63:1, 63:2, 64:1, 81, 83, 88, 101 (red red), 104, 105, 106, 108 ( cadmium red), 112, 114, 122 (quinacridone magenta), 123, 146, 149, 150, 166, 168, 170, 172, 177, 178, 179, 184, 185, 190, 193, 202, 209, 219, C. I. Pigment Violet 1 (rhodamine lake), 3, 5:1, 16, 19, 23, 38 and the like. Quinacridone pigments are preferred, C.I. I. Pigment Red 122, C.I. I. Pigment Violet 19, C.I. I. Pigment Red 122 and C.I. I. Pigment Violet 19 mixed crystal, or C.I. I. Pigment Red 202 and C.I. I. A mixed crystal of Pigment Violet 19 is more preferred.

The BET specific surface area of the pigment used is preferably about 10 m ² /g or more and about 1500 m ² /g or less, more preferably about 20 m ² /g or more and about 600 m ² /g or less, still more preferably about 50 m ² /g or more and about 300 m ² /g or less.
If the desired specific surface area is not readily available, general size reduction or grinding treatments (e.g., ball milling, jet milling, sonication) can be used to reduce the pigment to a relatively small particle size. good if
The volume average particle diameter (D50) of the water-dispersible pigment is preferably 10 nm or more and 200 nm or less in the ink.

The content of the coloring material in the ink is preferably 0.1% by mass or more and 15% by mass or less, more preferably 1% by mass or more and 10% by mass, from the viewpoints of improving image density, good fixability, and ejection stability. It is below.

In the present invention, a dye may be used in combination for the purpose of adjusting the color tone, but it should be used within a range that does not deteriorate the weather resistance.

-Pigment Derivatives-
In order to disperse the above pigment in water, a pigment derivative with a hydrophilic group may be used. Alternatively, a dispersion can be created by kneading. The use of a pigment derivative makes it possible to improve the stability of the dispersion, and a high effect can be expected by adding a small amount. Even if the structure of the hydrophobic part of the pigment and the pigment derivative used in the dispersion is different, it is possible to obtain sufficient adsorptive power, and it is possible to obtain sufficient storage stability. When the parts have the same structure, the adsorptive power is high and when the pigment derivative is adsorbed on the pigment surface, it is difficult to peel off, so that higher storage stability can be obtained. In the present invention, the quinacridone derivative represented by the general formula (1) is used as the pigment derivative, and the addition amount is preferably 1% by mass or more and 10% by mass or less based on the pigment, more preferably based on the pigment. It is 2 mass % or more and 8 mass % or less.
Moreover, the content of the quinacridone derivative represented by the general formula (1) in the ink is preferably 0.01% by mass or more and 1.00% by mass or less with respect to the total amount of the ink. When it is 0.01% by mass or more, sufficient storage stability and ejection stability can be obtained. Further, when the content is 1.00% by mass or less, the saturation of the printed matter does not decrease.
Furthermore, the ratio of the content of the quinacridone derivative in the ink to the content of the solvent A (the quinacridone derivative/the solvent A) is preferably 0.045 or more and 0.18 or less, and is within the above range. and high storage stability.
When the ink contains the quinacridone derivative represented by the general formula (1) as a mixture, the content of the quinacridone derivative represented by the general formula (1) is is the total content of the quinacridone derivative represented by the general formula (1), and refers to the content of the quinacridone derivative mixture represented by the general formula (1).

-Pigment Dispersant-
The dispersant used in the present invention is not particularly limited, and can be appropriately selected from dispersants used in preparation of the pigment dispersion according to the purpose.
For example, nonionic surfactants such as polyoxyethylene isodecyl ether, polyoxyethylene lauryl ether, polyoxyethylene-β-naphthyl ether, polyoxyethylene styrylphenyl ether, polyoxyethylene distyrylphenyl ether, or polyoxy Ethylene lauryl ether sulfate, polyoxyethylene-β-naphthyl ether sulfate, polyoxyethylene styryl phenyl ether phosphonate, polyoxyethylene distyryl phenyl carboxylate, lauryl ether phosphonate, octyl ether carboxylate, di Anionic surfactants such as styryl phenyl ether sulfate, styryl phenyl ether phosphonate and β-naphthyl ether carboxylate can be used as dispersants.

-Copolymer-
A copolymer can be used as a pigment dispersant in the present invention.
As the copolymer, an acrylic acid-based copolymer, a vinyl-based copolymer, a polyester-based copolymer, and a polyurethane-based copolymer can be used. Here, the acrylic acid-based copolymer refers to a copolymer using an acrylic acid derivative monomer and/or a methacrylic acid derivative monomer.

Furthermore, the present invention can have a repeating unit composed of a polymerizable monomer, which can be appropriately selected depending on the purpose without any particular limitation. Examples include polymerizable hydrophobic monomers, polymerizable hydrophilic monomers, Examples include polymerizable surfactants.
The hydrophobic monomer is not particularly limited, but unsaturated ethylene monomers having an aromatic ring such as benzyl (meth)acrylate, styrene, α-methylstyrene, 4-t-butylstyrene, 4-chloromethylstyrene; meth)methyl acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, dimethyl maleate, dimethyl itaconate, dimethyl fumarate, lauryl (meth)acrylate, tridecyl (meth)acrylate, (meth)acrylate ) tetradecyl acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, nonadecyl (meth) acrylate, eicosyl (meth) acrylate, henicosyl (meth) acrylate, (meth) Alkyl (meth)acrylates such as docosyl acrylate; 1-heptene, 3,3-dimethyl-1-pentene, 4,4-dimethyl-1-pentene, 3-methyl-1-hexene, 4-methyl-1- hexene, 5-methyl-1-hexene, 1-octene, 3,3-dimethyl-1-hexene, 3,4-dimethyl-1-hexene, 4,4-dimethyl-1-hexene, 1-nonene, 3, 5,5-trimethyl-1-hexene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, Examples include unsaturated ethylene monomers having an alkyl group such as 1-eicosene and 1-docose, and two or more of them may be used in combination.

Examples of hydrophilic monomers include, but are not limited to, (meth)acrylic acid or salts thereof, maleic acid or salts thereof, monomethyl maleate, itaconic acid, monomethyl itaconate, fumaric acid, 4-styrenesulfonic acid, 2-acrylamide- Anionic unsaturated ethylene monomers such as 2-methylpropanesulfonic acid, 2-methacryloxyethyl acid phosphoate, 1-methacryloxyethane-1,1-diphosphonic acid; 2-hydroxyethyl (meth)acrylate, diethylene glycol mono (Meth) acrylate, triethylene glycol mono (meth) acrylate, tetraethylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, (meth) acrylamide, N-methylol (meth) acrylamide, N-vinylformamide, N -Nonionic unsaturated ethylene monomers such as vinylacetamide, N-vinylpyrrolidone, acrylamide, N,N-dimethylacrylamide, Nt-butylacrylamide, N-octylacrylamide, Nt-octylacrylamide, diacetoneamide, etc. and may be used in combination of two or more.

Polymerizable surfactants include anionic or nonionic surfactants having at least one radically polymerizable unsaturated double bond group in the molecule.

Examples of the anionic surfactant include hydrocarbon compounds having a sulfate group and an allyl group (--CH ₂ --CH=CH ₂ ) such as an ammonium sulfate group ₍ --SO.sub.3 ^-- _NH.sub.4 ⁺ ), an ammonium sulfate group ₍ --SO.sub.3 ^- NH ₄ ⁺ ) and a hydrocarbon compound having a methacryl group [-CO-C(CH ₃ )=CH ₂ ], or a sulfate base such as an ammonium sulfate group (-SO ₃ ^- NH ₄ ⁺ ) and 1 and -propenyl group (-CH=CH ₂ CH ₃ ). Specific examples include Eleminol JS-20 and RS-300 manufactured by Sanyo Kasei Co., Ltd., Aqualon KH-10, Aqualon KH-1025, Aqualon KH-05, Aqualon HS-10, and Aqualon HS manufactured by Daiichi Kogyo Seiyaku Co., Ltd. -1025, Aqualon BC-0515, Aqualon BC-10, Aqualon BC-1025, Aqualon BC-20, and Aqualon BC-2020.

As the _{nonionic surfactant ,} a _hydrocarbon compound or an aromatic Hydrocarbon compounds are mentioned. Specific examples thereof include Aqualon RN-20, Aqualon RN-2025, Aqualon RN-30, and Aqualon RN-50 manufactured by Daiichi Kogyo Seiyaku Co., Ltd., and Latemul PD-104, Latemul PD-420, and Latemul PD manufactured by Kao Corporation. -430, and Latemul PD-450.

A copolymer is obtained by reacting a monomer component with a solvent in a flask equipped with a stirrer, a thermometer, and a nitrogen inlet tube at a temperature of about 50° C. or higher and 150° C. or lower in the presence of a polymerization initiator under nitrogen gas reflux. be done. The viscosity of the synthesized copolymer aqueous solution or aqueous dispersion can be adjusted by changing the molecular weight, and the monomer concentration, polymerization initiator amount, polymerization temperature, and polymerization time may be changed during polymerization.
With respect to the polymerization temperature, a short-time polymerization at a high temperature tends to yield a low-molecular-weight copolymer, while a long-time polymerization at a low temperature tends to yield a high-molecular-weight copolymer. With respect to the content of the polymerization initiator, the larger the content, the easier it is to obtain a low-molecular-weight copolymer, and the lower the content, the easier it is to obtain a high-molecular-weight copolymer. Regarding the monomer concentration during the reaction, a high concentration tends to yield a low-molecular-weight copolymer, and a low concentration tends to yield a high-molecular-weight copolymer. The weight-average molecular weight of the copolymer is not particularly limited and can be appropriately selected depending on the intended purpose. ,000 or more and 30,000 or less is more preferable. When the weight-average molecular weight is within the preferred range, it is advantageous in terms of good dispersion stability and ejection stability when used in an ink for inkjet recording.
The weight average molecular weight can be measured, for example, by gel permeation chromatography (GPC).

<Organic solvent>
The organic solvent used in the present invention is not particularly limited, and any water-soluble organic solvent can be used. Examples thereof include polyhydric alcohols, ethers such as polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, and sulfur-containing compounds.
Specific examples of polyhydric alcohols include ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, and 1,4-butane. Diol, 2,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol , 2,4-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, 1,5-hexanediol, glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-hexanediol, ethyl-1,2,4-butanetriol, 1,2,3-butanetriol, 2,2,4-trimethyl- 1,3-pentanediol, petriol and the like.
Examples of 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.
Examples of polyhydric alcohol aryl ethers include ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.
Nitrogen-containing heterocyclic compounds include 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, γ-butyrolactone and the like. mentioned.
Amides include formamide, N-methylformamide, N,N-dimethylformamide, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide and the like.
Amines include monoethanolamine, diethanolamine, triethylamine, and the like.
Examples of sulfur-containing compounds include dimethylsulfoxide, sulfolane, thiodiethanol and the like.
Other organic solvents include propylene carbonate and ethylene carbonate.
It is preferable to use an organic solvent having a boiling point of 250° C. or less because it not only functions as a wetting agent but also provides good drying properties.

As the organic solvent, polyol compounds having 8 or more carbon atoms and glycol ether compounds are also preferably used. Specific examples of polyol compounds having 8 or more carbon atoms include 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol.
Specific examples of glycol ether compounds include polyhydric alcohol alkyls such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether. Ethers; polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, and the like.

A polyol compound having 8 or more carbon atoms and a glycol ether compound can improve ink permeability when paper is used as a recording medium.

The content of the organic solvent in the ink is not particularly limited and can be appropriately selected according to the purpose. 20% by mass or more and 60% by mass or less is more preferable.

The ink of the present invention contains at least one solvent A having an SP value of 9.0 or more and 11.0 or less. As a result, the wettability to the recording medium is improved, and the ink component permeates even commercial printing paper such as coated paper having a coating layer with poor ink absorption, making it possible to suppress beading.

なお式（１）において、ΔＥ：凝集エネルギー密度、Ｖ：モル体積、Δｅ_ｉ：原子または原子団の蒸発エネルギー、Δｖ_ｉ：原子または原子団のモル体積、である。 The SP value is a solubility parameter, and is generally widely used as an index of the affinity and solubility of materials that are dissolved or dispersed in water or solvents, such as solvents, resins, and pigments. Various methods have been proposed for obtaining the SP value, such as a method of measuring by experiment, a method of calculating from the measurement of physical properties such as immersion heat, and a method of calculating from the molecular structure. A method of calculating from the molecular structure is used. This method is effective in that the SP value can be calculated if the molecular structure is known, and in that the difference from the experimentally measured value is small. In the Fedors method, the evaporation energy Δe _i and the molar volume Δv _i of each atom or atomic group at 25° C. are determined as shown in the table below, and the SP value can be obtained by substituting these values into the formula (1). . In the present invention, the SP value at 25° C. is used, and temperature conversion is not performed.

In formula (1), ΔE: cohesive energy density, V: molar volume, Δe _i : vaporization energy of an atom or atomic group, and Δv _i : molar volume of an atom or atomic group.

For example, the SP value of isopropylidene glycerol (iPDG) is calculated as follows from the values in Table 1 below.
SP value=(14150/139.8) ^1/2 =10.1 (cal/cm ³ ) ^1/2

As the solvent A, water-soluble ones are preferable, and in particular 3-ethyl-3-hydroxymethyloxetane (SP value 10.7), isopropylideneglycerol (SP value 9.8) and N,N-dimethyl-β-butoxy Propionamide (SP value 9.8) is preferred. These solvents are excellent in drying properties.
Organic solvents with an SP value of less than 9.0 generally have very low solubility in water and are likely to separate, and organic solvents with an SP value of more than 11.0 deteriorate drying and beading. Therefore, the ink cannot be composed only of these solvents, and it is necessary to mix them with a solvent A having an SP value of 9.0 or more and 11.0 or less.
The content of solvent A with an SP value of 9.0 or more and 11.0 or less is less than 10% by mass, preferably 2% or more and 8% or less by mass of the entire ink. If the content is 2% by mass or more, the beading suppressing effect is further improved. Further, when the content is less than 10% by mass, ejection stability is not deteriorated due to an increase in ink viscosity, and it is more preferably 8% by mass or less.
By using a gas chromatograph-mass spectrometer (GC-MS), it is possible to quantify organic compounds containing solvents, and to determine the content of solvent A in the ink.

<Water>
The content of water in the ink is not particularly limited and can be appropriately selected according to the purpose. % or more and 60 mass % or less is more preferable.

-Resin emulsions Resin emulsions with excellent film-forming properties (image forming properties), as well as high water repellency, high water resistance, and high weather resistance. It is useful for image recording, and examples thereof include condensed synthetic resins, addition synthetic resins, and natural polymer compounds.
Examples of the condensed synthetic resins include polyester resins, polyurethane resins, polyepoxy resins, polyamide resins, polyether resins, poly(meth)acrylic resins, acryl-silicone resins, fluorine-based resins, and the like. Examples of the addition type synthetic resins include polyolefin resins, polystyrene resins, polyvinyl alcohol resins, polyvinyl ester resins, polyacrylic acid resins, and unsaturated carboxylic acid resins. Examples of the natural polymer compound include celluloses, rosins, and natural rubber. Further, as the resin emulsion, a resin itself having a hydrophilic group and having self-dispersibility, or a resin having no dispersibility but being imparted with dispersibility by a surfactant or a resin having a hydrophilic group can be used. Among these, polyacrylic resins and polyurethane resins are particularly preferred, and two or more of the above resin emulsions may be used in combination.
In the case of emulsion polymerization of unsaturated monomers, the unsaturated monomer, polymerization initiator, surfactant, chain transfer agent, chelating agent, pH adjuster, etc. are added and reacted in water to form a resin emulsion. Therefore, the water-dispersible resin can be easily obtained, the resin structure can be easily changed, and the desired properties can be easily obtained.

Since the resin emulsion causes molecular chain rupture such as dispersion destruction and hydrolysis under strongly alkaline or strongly acidic conditions, the pH is preferably 4 or more and 12 or less. 6 or more and 11 or less are more preferable, and 7 or more and 10 or less are still more preferable.

The average particle size (D50) of the resin emulsion is related to the viscosity of the dispersion, and if the composition is the same, the smaller the particle size, the higher the viscosity at the same solid content. The average particle size (D50) of the water-dispersible resin is preferably 50 nm or more so that the ink does not have an excessively high viscosity. Also, if the particle diameter is several tens of μm, it cannot be used because it is larger than the nozzle opening of the inkjet head. If there are particles in the ink that are smaller than the nozzle orifice but have a large particle diameter, the ejectability is deteriorated. Therefore, the average particle diameter (D50) is more preferably 200 nm or less, still more preferably 150 nm or less, so as not to impair the ink ejection property.

Further, the resin emulsion has a function of fixing the water-dispersible colorant to the surface of paper, and has a function of forming a film at room temperature to improve the fixability of the colorant. Therefore, the minimum film-forming temperature (MFT) of the resin emulsion is preferably 30° C. or lower. Further, when the glass transition temperature is -40°C or lower, the viscosity of the resin film increases and tackiness occurs in the printed matter, so the glass transition temperature is preferably -30°C or higher.
The solid content of the resin emulsion in the ink is preferably 0.5% by mass or more and 10% by mass or less, more preferably 1% by mass or more and 8% by mass or less.

-wax-
The ink according to the present invention may contain wax, and the wax may be either water-soluble or water-dispersible. As water-soluble waxes, waxes having hydrophilic groups such as hydroxyl groups, carboxyl groups, ethylene oxide groups, and amine groups can be used, and as water-dispersible waxes, wax emulsions can be mainly used.

Specifically, plant waxes such as carnauba wax, candelilla wax, beeswax, rice wax, and lanolin, animal waxes, paraffin waxes, microcrystalline waxes, polyethylene waxes, polypropylene waxes, oxidized polyethylene waxes, and petroleum waxes such as petrolatum. , mineral waxes such as montan wax and ozokerite, carbon wax, Hoechst wax, polyethylene wax, synthetic waxes such as stearic acid amide, natural and synthetic wax emulsions such as α-olefin/maleic anhydride copolymer, and blended waxes, etc. can be used alone or in combination. Other latexes, colloidal solutions, suspensions, etc. can also be used. In the present invention, polyethylene wax is desirable because it has good solubility and dispersibility in a water-soluble solvent.

Commercially available waxes can be used, and specific examples thereof include Cerosol 524 (carnauba wax, melting point 83° C., particle size 200 nm, manufactured by Chukyo Yushi Co., Ltd.), HYTEC E-6500 (polyethylene wax, melting point 140 ° C., particle size 60 nm, manufactured by Toho Chemical), HYTEC E-8237 (polyethylene wax, melting point 106 ° C., particle size 80 nm, manufactured by Toho Chemical), HYTEC P-9018 (polypropylene wax, melting point 156 ° C., particle size 60 nm, manufactured by Toho Chemical ), Nopcoat PEM-177 (polyolefin wax, melting point 105 ° C., particle size 10 nm, manufactured by San Nopco), AQUACER498 (paraffin wax, melting point 58 ° C., manufactured by BYK Chemie Japan), AQUACER535 (mixed wax, melting point 95 ° C., BYK Chemie Japan), AQUACER531 (polyethylene wax, melting point 130°C, particle size 123 nm, BYK Chemie Japan), AQUACER515 (polyethylene wax, melting point 135°C, particle size 33 nm, BYK Chemie Japan), and the like.

The melting point of the wax is preferably in the range of 70°C or higher and 170°C or lower, more preferably 100°C or higher and 140°C or lower. If the melting point is 70° C. or higher, the image will not be sticky, and image transfer will not occur even if the images are superimposed. If the melting point is 170° C. or less, the image is melted by frictional heat when the image is rubbed, and slipperiness is obtained, so that the image has good rub resistance.

The volume average particle size of the wax is preferably 200 nm or less, more preferably 20 nm or more and 150 nm or less. If it is 200 nm or less, it will not get caught on the nozzle or the filter in the head, and good ejection can be obtained.

The amount of the wax solid content added to the ink is preferably in the range of 0.05% by mass to 2% by mass, more preferably 0.1% by mass to 0.5% by mass. When the amount added is 0.1% by mass or more, it is possible to impart slipperiness to the image surface after printing, and to maintain high abrasion resistance of the image. Further, when the amount added is 0.5% by mass or less, the wax can be dissolved or dispersed in the solvent in the ink, so that the wax does not deposit and adhere to the head, so that the ink droplets can be ejected satisfactorily. becomes possible.

-Surfactant-
Any of silicone surfactants, fluorine surfactants, amphoteric surfactants, nonionic surfactants, and anionic surfactants can be used as surfactants.
Surfactants are broadly classified into anionic surfactants, nonionic surfactants, and amphoteric surfactants according to their hydrophilic groups, and can be broadly classified into fluorine surfactants, acetylenic surfactants, etc. according to their hydrophobic groups. can.

Examples of anionic surfactants include polyoxyethylene alkyl ether acetates, dodecylbenzenesulfonates, laurates, and salts of polyoxyethylene alkyl ether sulfates.

Examples of nonionic surfactants include polyols, glycol ethers, polyoxyethylene alkyl ethers, polyoxyethylene alkyl esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkylphenyl ethers, polyoxyethylene alkylamines, polyoxyethylene Alkylamides, acetylene glycol and the like can be mentioned.

The silicone-based surfactant is not particularly limited and can be appropriately selected depending on the purpose.
Among them, those that do not decompose even at high pH are preferable. Those having an oxyethylene group or a polyoxyethylene polyoxypropylene group are particularly preferred because they exhibit good properties as water-based surfactants. As the silicone-based surfactant, a polyether-modified silicone-based surfactant can also be used, and examples thereof include compounds in which a polyalkylene oxide structure is introduced into the side chain of the Si portion of dimethylsiloxane.

Examples of fluorine-based surfactants include perfluoroalkylsulfonic acid compounds, perfluoroalkylcarboxylic acid compounds, perfluoroalkylphosphoric acid ester compounds, perfluoroalkylethylene oxide adducts, and perfluoroalkyl ether groups in side chains. Polyoxyalkylene ether polymer compounds are particularly preferred due to their low foaming properties. Examples of the perfluoroalkylsulfonic acid compound include perfluoroalkylsulfonic acid and perfluoroalkylsulfonate. Examples of the perfluoroalkylcarboxylic acid compounds include perfluoroalkylcarboxylic acids and perfluoroalkylcarboxylic acid salts. As the polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in a side chain, a sulfuric acid ester salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in a side chain, and a perfluoroalkyl ether group in a side chain Examples thereof include salts of polyoxyalkylene ether polymers. Counter ions of salts in these _{fluorosurfactants} include Li, Na, K, _NH4 , _NH3CH2CH2OH , _{NH2 ( CH2CH2OH} ) ₂ , and _{NH ( CH2CH2OH} ). ₃ , etc.

Examples of amphoteric surfactants include laurylaminopropionate, lauryldimethylbetaine, stearyldimethylbetaine, lauryldihydroxyethylbetaine and the like.

Nonionic surfactants include, for example, polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkylamine, polyoxyethylene alkylamide, polyoxyethylene propylene block polymer, sorbitan fatty acid ester, polyoxyethylene sorbitan Examples include fatty acid esters and ethylene oxide adducts of acetylene alcohol.

Examples of anionic surfactants include polyoxyethylene alkyl ether acetates, dodecylbenzene sulfonates, laurates, and salts of polyoxyethylene alkyl ether sulfates.
These may be used individually by 1 type, or may use 2 or more types together.

（上記式中、Ｒ５は、水素原子又は炭素数１～４のアルキル基を表し、ｍは０～２３の整数、ｎは１～１０の整数、ａは１～２３の整数、ｂは０～２３の整数を表す。） -Polyether-modified siloxane compound-
A polyether-modified siloxane compound, which is a surfactant, can also be used as a material for the ink used in the present invention. This makes it difficult for the ink to wet the ink-repellent layer of the head nozzle plate, prevents ejection failure due to adhesion of the ink to the nozzles, and improves the ejection stability. In addition, the ink is less likely to adhere to the ink-repellent layer surface of the nozzle, which tends to cause problems, and is less likely to cause ejection failure. Among them, those represented by the following general formula (2) are preferable, and in particular, they do not impair dispersion stability depending on the type of water-dispersible colorant and the combination of organic solvents, have low dynamic surface tension, and have permeability and leveling properties. A higher value is preferred. These polyether-modified siloxane compounds may be used singly or in combination of two or more.

(In the above formula, R5 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, m is an integer of 0 to 23, n is an integer of 1 to 10, a is an integer of 1 to 23, b is 0 to represents an integer of 23.)

Examples of the compound represented by the general formula (2) include compounds represented by the following formulas (2-1) to (2-3).

Further, commercially available polyether-modified siloxane compound surfactants exhibiting the same effect as the above compounds include 71ADDITIVE, 74ADDITIVE, 57ADDITIVE, 8029ADDITIVE, 8054ADDITIVE, 8211ADDITIVE, 8019ADDITIVE, 8526ADDITIVE, FZ- manufactured by TORAY Dow Corning. 2123, FZ-2191, TSF4440, TSF4441, TSF4445, TSF4446, TSF4450, TSF4452, TSF4460 manufactured by Momentive Performance Materials, Silface SAG002, Silface SAG003, Silface SAG005, manufactured by Nissin Chemical Industry Co., Ltd. Silface SAG503A, Silface SAG008, Silface SJM003, TEGO_Wet_KL245, TEGO_Wet_250, TEGO_Wet_260, TEGO_Wet_265, TEGO_Wet_270, TEGO_Wet_280 manufactured by Evonik, BYK-345, BYK-345, BYK-347 manufactured by BYK-Chemie Japan 375, BYK-377 and the like.

If necessary, the above polyether-modified siloxane compound surfactant may be used in combination with a fluorosurfactant, silicone surfactant, acetylene glycol or acetylene alcohol surfactant.

The content of the surfactant in the ink is preferably 0.001% by mass or more and 5% by mass or less, more preferably 0.5% by mass or more and 3% by mass or less. If it is 0.001% by mass or more, the effect of adding the surfactant can be obtained. However, if the amount exceeds 5 mass, the effect of addition is saturated, so increasing the amount is meaningless.

-Other ingredients-
In addition to the above components, the ink of the present invention may optionally contain various known additives. Examples thereof include penetrants, foam inhibitors (defoamers), pH adjusters, antiseptic and antifungal agents, chelating agents, rust inhibitors, antioxidants, ultraviolet absorbers, oxygen absorbers, light stabilizers, etc. are mentioned.

（上記式中、Ｒ′はメチル基又はエチル基、Ｒ″は水素又はメチル基、Ｒ″′はエチル基又はプロピル基である。） <Penetrant>
As the penetrant, at least one non-wetting agent polyol compound or glycol ether compound having 8 to 11 carbon atoms is preferable. Here, non-wetting agent means having a solubility of between 0.2% and 5.0% by mass in water at 25°C. Among these penetrants, 1,3-diol compounds represented by the following general formula (3) are preferable, and 2-ethyl-1,3-hexanediol [solubility: 4.2% (25°C)], 2 , 2,4-trimethyl-1,3-pentanediol [solubility: 2.0% (25° C.)] is particularly preferred.

(In the above formula, R' is a methyl group or an ethyl group, R" is a hydrogen or a methyl group, and R''' is an ethyl group or a propyl group.)

Other non-wetting agent polyol compounds include, for example, 2-ethyl-2-methyl-1,3-propanediol, 3,3-dimethyl-1,2-butanediol, 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-diol.
The content of the penetrant in the ink is preferably 0.5% by mass or more and 4% by mass or less, more preferably 1% by mass or more and 3% by mass or less. If it is 0.5% by mass or more, the effect of ink permeability is obtained, and the image quality is improved. Moreover, if it is 4% by mass or less, it is sufficiently soluble in the ink, so that problems such as separation and an increase in the initial viscosity of the ink do not occur.

<Antifoaming agent>
The antifoaming agent is not particularly limited, and examples thereof include silicone antifoaming agents, polyether antifoaming agents, and fatty acid ester antifoaming agents. These may be used individually by 1 type, or may use 2 or more types together. Among these, silicone-based antifoaming agents are preferred because of their excellent foam breaking effect.

<pH adjuster>
The pH adjuster is not particularly limited as long as it can adjust the pH to 7 or higher, and examples thereof include amines such as diethanolamine and triethanolamine.

<Preservative and antifungal agent>
The antiseptic and antifungal agent is not particularly limited, and examples thereof include 1,2-benzisothiazolin-3-one.

- Chelating reagent -
Chelating agents include, for example, sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, sodium uramil diacetate and the like.

<Antirust agent>
The rust inhibitor is not particularly limited, and examples thereof include acidic sulfites and sodium thiosulfate.

<Antioxidant>
Examples of antioxidants include phenol antioxidants (including hindered phenol antioxidants), amine antioxidants, sulfur antioxidants, phosphorus antioxidants, and the like.

<Ultraviolet absorber>
Examples of the ultraviolet absorber include benzophenone ultraviolet absorbers, benzotriazole ultraviolet absorbers, salicylate ultraviolet absorbers, cyanoacrylate ultraviolet absorbers, and nickel complex ultraviolet absorbers.

－Ink manufacturing－
The ink of the present invention is produced by dispersing or dissolving a pigment, the quinacridone derivative, an organic solvent, water, and other components added as necessary in an aqueous medium, and further stirring and mixing as necessary. This stirring and mixing can be performed by, for example, a sand mill, homogenizer, ball mill, paint shaker, ultrasonic disperser, etc. Stirring and mixing is performed by a stirrer using ordinary stirring blades, a magnetic stirrer, a high-speed disperser, etc. be able to.

-Ink properties-
The physical properties of the ink of the present invention are not particularly limited and can be appropriately selected according to the purpose.
However, if the static surface tension of the ink is 20 mN/m or more and the dynamic surface tension is 34 mN/m or less at a bubble lifetime of 15 msec according to the maximum bubble pressure method, sufficient wettability to the recording medium is ensured. In spite of the fact that it is possible to do so, it is difficult to wet the nozzle plate optool water-repellent film of the inkjet head, and the ejection stability can be ensured, so that the ink is extremely stable, which is preferable.
The viscosity of the ink at 25° C. is preferably 5 mPa·s or more and 25 mPa·s or less, more preferably 6 mPa·s or more and 20 mPa·s or less. If it is 5 mPa·s or more, the effect of improving print density and character quality can be obtained. Further, if the viscosity is 25 mPa·s or less, the ink ejection property can be ensured.
The viscosity can be measured at 25° C. using, for example, a viscometer (RE-550L, manufactured by Toki Sangyo Co., Ltd.).

The ink of the present invention can be used as an inkjet head to change the internal volume of the ink channel by deforming the vibration plate forming the wall surface of the ink channel using a piezoelectric element as a pressure generating means for pressurizing the ink in the ink channel. A so-called piezo type in which ink droplets are ejected (see Japanese Patent Application Laid-Open No. 2-51734), or a so-called thermal type in which a heating resistor is used to heat ink in the ink flow path to generate bubbles. Japanese Patent Application Laid-Open No. 61-59911), a vibration plate that forms the wall surface of the ink channel and an electrode are arranged opposite each other, and the vibration plate is deformed by an electrostatic force generated between the vibration plate and the electrode. It can be used favorably in printers equipped with any type of inkjet head, such as an electrostatic type that ejects ink droplets by changing the internal volume of the ink flow path (see Japanese Patent Application Laid-Open No. 6-71882).
Further, the ink of the present invention may be stored in an ink storage container such as an ink cartridge for use.

<Ink container>
The ink storage container of the present invention contains the ink of the present invention in the container, and further has other members appropriately selected as necessary.
The container is not particularly limited, and its shape, structure, size, material, etc. can be appropriately selected according to the purpose. preferably have at least

<Recording medium>
The recording medium on which recording can be performed using the ink of the present invention is not particularly limited and can be appropriately selected according to the purpose. Examples include sheets and general-purpose printing paper. However, the ink of the present invention is very excellent in that it can record as well on commercial printing paper as on other papers.
The term "commercial printing paper" as used herein refers to printing paper having a coating layer on at least one surface of a support. For example, printing paper using a filler such as calcium carbonate or kaolin as the coating layer material mentioned. Coated printing paper, which is an example of commercial printing paper, has a coating layer made of a white pigment such as clay (kaolin) or calcium carbonate and an adhesive (binder) such as starch.

A recorded matter having an image formed using the ink of the present invention has high image quality, does not bleed, and is excellent in stability over time. can be done.
Excellent image quality (image density, saturation, beading, color bleeding) among recording media, high glossiness, excellent smear fixability, and liquid absorption characteristics within a certain range. A recording medium within is suitable. Specifically, a commercial printing paper having a coating layer on at least one surface of a support can be mentioned, and the surface having the coating layer is treated with pure water at a contact time of 100 ms as measured by a dynamic scanning liquid absorption meter. transferred to the printing paper is 2 mL/m ² or more and 35 mL/m ² or less, and the amount of pure water transferred to the printing paper at a contact time of 400 ms is 3 mL/m ² or more and 40 mL/m ² or less. Printing paper is preferred. If the amount of pure water transferred is too small, beading (a phenomenon in which adjacent dots are attracted to each other, causing an image to appear uneven) and color bleeding (bleeding between colors) tend to occur. However, if the amount of transferred pure water is too large, the ink dot diameter after recording may become smaller than the desired diameter and the solid image may not be filled.

The amount of pure water transferred can be measured using a dynamic scanning liquid absorption meter (K350 series D type, manufactured by Kyowa Seiko Co., Ltd.). The amount of transfer at a contact time of 100 ms can be obtained by interpolation from the measured values of the amount of transfer at contact times adjacent to the contact time.

Examples of commercially available printing papers having liquid absorption properties within the aforementioned range include POD Gloss Coat, OK Top Coat+, OK Kinto+, SA Kinto+ (manufactured by Oji Paper Co., Ltd.), Super Midal, Aurora Coat, Space DX (manufactured by Nippon Paper Industries Co., Ltd.), α-mat, Mu-coat (manufactured by Hokuetsu Paper Co., Ltd.), Raicho Art, Raicho Super Art (manufactured by Chuetsu Pulp Industries, Ltd.), Pearl Coat N (manufactured by Mitsubishi Paper Mills, Ltd.), and the like.

<Recording device, recording method>
The ink of the present invention can be suitably used for various inkjet recording apparatuses, such as printers, facsimile machines, copiers, printer/facsimile/copier complex machines, stereolithography machines, and the like.
In the present invention, a recording apparatus and a recording method refer to an apparatus capable of ejecting ink, various treatment liquids, and the like onto a recording medium, and a method of performing recording using the apparatus. A recording medium means a medium to which ink or various processing liquids can adhere even temporarily.
This recording apparatus can include not only a head portion for ejecting ink, but also means for feeding, conveying, and discharging a recording medium, and other devices called pre-processing devices and post-processing devices. .
The recording apparatus and recording method may have heating means used in the heating process and drying means used in the drying process. The heating means and drying means include, for example, means for heating and drying the printing surface and the back surface of the recording medium. The heating means and drying means are not particularly limited, but for example, hot air heaters and infrared heaters can be used. Heating and drying can be performed before, during, or after printing.
Also, the recording apparatus and recording method are not limited to those that visualize significant images such as characters and graphics with ink. Examples include those that form patterns such as geometric patterns, and those that form three-dimensional images.
In addition, unless otherwise specified, the recording apparatus includes both a serial type apparatus in which the ejection head is moved and a line type apparatus in which the ejection head is not moved.
Furthermore, this recording device can be used not only as a desktop type, but also as a wide recording device that can print on A0 size recording media, and for example, can use continuous paper wound into a roll as a recording medium. A continuous feed printer is also included.
An example of a recording apparatus will be described with reference to FIGS. 1 and 2. FIG. FIG. 1 is a perspective explanatory view of the device. FIG. 2 is a perspective explanatory view of the main tank. An image forming apparatus 400 as an example of a recording apparatus is a serial image forming apparatus. A mechanical unit 420 is provided inside the exterior 401 of the image forming apparatus 400 . Each ink container 411 of the main tank 410 (410k, 410c, 410m, 410y) for each color of black (K), cyan (C), magenta (M), and yellow (Y) is packed with, for example, an aluminum laminated film. It is made up of members. The ink containing portion 411 is housed, for example, in a container case 414 made of plastic. Thus, the main tank 410 is used as an ink cartridge for each color.
On the other hand, a cartridge holder 404 is provided on the far side of the opening when the cover 401c of the apparatus main body is opened. A main tank 410 is detachably attached to the cartridge holder 404 . As a result, each ink discharge port 413 of the main tank 410 communicates with the ejection head 434 for each color via the supply tube 436 for each color, and ink can be ejected from the ejection head 434 onto the recording medium.

This recording apparatus can include not only a portion that ejects ink, but also devices called pre-processing devices and post-processing devices.
As an aspect of the pre-treatment device and the post-treatment device, it has a pre-treatment liquid and a post-treatment liquid in the same manner as in the case of inks such as black (K), cyan (C), magenta (M), and yellow (Y). There is a mode in which a liquid container and a liquid ejection head are added, and the pretreatment liquid and the posttreatment liquid are ejected by an inkjet recording method.
As another aspect of the pre-treatment device and the post-treatment device, there is an aspect in which a pre-treatment device and a post-treatment device using a method other than the inkjet recording method, such as a blade coating method, a roll coating method, and a spray coating method, are provided.

<Records>
The ink recorded matter of the present invention has an image formed on a recording medium using the ink of the present invention.
A recorded matter can be obtained by recording with an inkjet recording apparatus and an inkjet recording method.

The use of the ink of the present invention is not particularly limited and can be appropriately selected according to the intended purpose. Furthermore, it can be used not only as an ink to form two-dimensional characters and images, but also as a three-dimensional modeling material for forming a three-dimensional three-dimensional image (three-dimensional object).
A known three-dimensional modeling apparatus for forming three-dimensional objects can be used, and is not particularly limited. be able to. The three-dimensional object includes a three-dimensional object obtained by applying ink repeatedly. It also includes a molded product obtained by processing a structure obtained by applying ink onto a base material such as a recording medium. Molded processed products are, for example, products obtained by subjecting recorded matter or structures formed in the form of sheets or films to molding processes such as heat stretching and punching. It is suitably used for applications where molding is performed after the surface is decorated, such as electronic equipment, meters of cameras, etc., and operation panel panels.

In the present invention, the terms image formation, recording, printing, and printing are all synonymous.

The terms recording medium, medium, and printed material are all synonymous.

EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. "Parts" and "%" in the examples are "mass parts" and "mass%" unless otherwise specified.

<Quinacridone derivative mixture>
50 parts of chlorosulfonic acid was charged into a 200 mL four-necked flask cooled in an ice water bath, and C.I. I. Pigment Red 122 (Red No. 81 manufactured by Dainichiseika Co., Ltd.) (5 parts) was added little by little over 5 minutes at a temperature of 10 to 15°C. After further stirring at 80° C. for 3 hours and returning to room temperature, the reaction solution was added to 600 parts of ice water with stirring to precipitate a sulfonated product. Then, it was separated by filtration, washed with 300 parts of 0.1% hydrochloric acid, and further washed with 300 parts of deionized water to obtain a red intermediate wet cake. 150 mL of water was added to this wet cake, and the mixture was cooled to 4° C. in an ice water bath while stirring. 10.75 g of diethylamine was added dropwise thereto over 5 minutes, and the mixture was further stirred at a temperature of 70° C. for 3 hours. After cooling to room temperature, 15.6 g of concentrated hydrochloric acid was added while stirring, and the deposited red precipitate was collected by filtration. The wet cake was stirred, filtered and washed with ion-exchanged water, and dried under reduced pressure by heating at 60° C. for 2 days to obtain a maroon powdery quinacridone derivative mixture of the following formulas (1-1) and (1-2). 2.67 g of a mixture of

<Copolymer>
62.0 parts (525 mmol) of 1,6-hexanediol (manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in 700 mL of methylene chloride, and 20.7 parts (262 mmol) of pyridine was added. To this solution, a solution obtained by dissolving 50.0 parts (262 mmol) of 2-naphthalenecarbonyl chloride (manufactured by Tokyo Chemical Industry Co., Ltd.) in 100 mL of methylene chloride was added dropwise with stirring over 2 hours, followed by stirring at room temperature for 6 hours. did. After washing the resulting reaction solution with water, the organic phase is isolated, dried over magnesium sulfate and evaporated. The residue was purified by silica gel column chromatography using a mixed solvent of methylene chloride/methanol (volume ratio: 98/2) as an eluent to obtain 52.5 parts of 2-naphthoic acid-2-hydroxyethyl ester. .
Next, 42.1 parts (155 mmol) of 2-naphthoic acid-2-hydroxyethyl ester was dissolved in 80 mL of dry methyl ethyl ketone and heated to 60°C. To this solution, a solution obtained by dissolving 24.0 parts (155 mmol) of 2-methacryloyloxyethyl isocyanate (Kalenz MOI, manufactured by Showa Denko KK) in 20 mL of dry methyl ethyl ketone was added dropwise with stirring over 1 hour, and then the mixture was heated to 70°C. and stirred for 12 hours. After cooling to room temperature, the solvent was distilled off. The residue was purified by silica gel column chromatography using a mixed solvent of methylene chloride/methanol (volume ratio: 99/1) as an eluent to obtain 57.0 parts of a monomer having a structure represented by the following formula (3). got

Next, 1.20 parts (16.7 mmol) of acrylic acid (manufactured by Sigma-Aldrich) and 7.12 parts (16.7 mmol) of the monomer having the structure represented by the formula (3) were dissolved in 40 mL of dry methyl ethyl ketone. to prepare a monomer solution. Add 10% of the monomer solution to a 100 mL flask equipped with a condenser and heat to 75° C. under a stream of argon, then add 0.273 parts (10%) of the remaining monomer solution while stirring the solution. 1.67 mmol) of 2,2'-azoiso(butyronitrile) (manufactured by Tokyo Chemical Industry Co., Ltd.) was added dropwise over 1.5 hours, and the mixture was further stirred at 60°C for 15 hours. After cooling to room temperature, the resulting reaction solution was dropped into hexane. The precipitated copolymer was separated by filtration and dried under reduced pressure to obtain 8.13 parts of a copolymer. While dissolving the obtained copolymer in an aqueous solution of dimethylethanolamine so as to neutralize the acid by 100%, the concentration of the copolymer is adjusted with ion-exchanged water so that the concentration of the copolymer becomes 10%, thereby obtaining a copolymer. rice field. The weight average molecular weight of the resulting copolymer was 21,800.

[Example 1]
<Dispersion 1>
3.2 parts of the copolymer and 0.8 parts of dimethylaminoethanol are added to 81 parts of ion-exchanged water and dissolved, and the compound represented by the above formula (1-1) and the formula (1-2) are 1.0 parts of a <quinacridone derivative mixture>, which is a mixture of the compounds represented, and 14.0 parts of a quinacridone pigment (mixed crystal pigment of C.I. Pigment Red 202 and Pigment Violet 19, Cinquasia Magenta D4500J manufactured by BASF) were added. Pre-dispersion was performed for 10 minutes with an ultrasonic homogenizer. This is put into an Ultra Asspec Mill UAM015 type (manufactured by Kotobuki Kogyo Co., Ltd.) using 0.05 mm zirconia beads and subjected to dispersion treatment for 1 hour, and the resulting dispersion is filtered through a 1 μm filter to obtain a pigment. Dispersion 1 with a concentration of 14% was obtained.

<Ink 1>
Dispersion 1 36.0 parts 3-ethyl-3-hydroxymethyloxetane 1.0 parts 3-methyl-1,3-butanediol 19.0 parts 1,2 - Propanediol ... 10.0 parts 2-Ethyl-1,3-hexanediol ... 2.0 parts Polyoxyethylene polyoxypropylene alkyl ether ... 1.0 parts (Emulgen LS-106, manufactured by Kao Corporation)
· 2-amino-2-ethyl-1,3-propanediol ... 0.5 parts · Antiseptic and antifungal agent ... 0.1 parts (Proxel LV, manufactured by Arch Chemicals Japan)
Ion-exchanged water...30.4 parts After dissolving the components other than Dispersion 1 in ion-exchanged water to prepare a vehicle, mixing with Dispersion 1 and filtering through a filter with an average pore size of 1 μm, the ink is obtained. got 1.

[Example 2]
In Ink 1 of Example 1, 1.0 parts of 3-ethyl-3-hydroxymethyloxetane was changed to 2.0 parts, and 19.0 parts of 3-methyl-1,3-butanediol was changed to 18.0 parts. Ink 2 was obtained using the same formulation and method as in Example 1, except for the above.

[Example 3]
In Ink 1 of Example 1, 1.0 parts of 3-ethyl-3-hydroxymethyloxetane was changed to 5.0 parts, and 19.0 parts of 3-methyl-1,3-butanediol was changed to 15.0 parts. Ink 3 was obtained using the same formulation and method as in Example 1, except for the above.

[Example 4]
Ink was prepared using the same formulation and method as in Example 3, except that 5.0 parts of 3-ethyl-3-hydroxymethyloxetane in Ink 3 of Example 3 was changed to 5.0 parts of tripropylene glycol monomethyl ether. Got 4.

[Example 5]
Ink 5 was prepared using the same formulation and method as in Example 3, except that 5.0 parts of 3-ethyl-3-hydroxymethyloxetane in Ink 3 of Example 3 was changed to 5.0 parts of methyltriglycol. Obtained.

[Example 6]
Ink 6 was prepared using the same formulation and method as in Example 3, except that 5.0 parts of 3-ethyl-3-hydroxymethyloxetane in Ink 3 of Example 3 was changed to 5.0 parts of isopropylideneglycerol. Obtained.

[Example 7]
The same formulation as in Example 3 except that in Ink 3 of Example 3, 5.0 parts of 3-ethyl-3-hydroxymethyloxetane was changed to 5.0 parts of N,N-dimethyl-β-butoxypropionamide , to obtain Ink 7.

[Example 8]
<Dispersion 2>
14.0 parts of the quinacridone pigment (C.I. Pigment Red 202 and Pigment Violet 19 mixed crystal pigment, Cinquasia Magenta D4500J manufactured by BASF) in Dispersion 1 of Example 1 is added to quinacridone pigment (C.I. Pigment Red 122, Dispersion 2 was obtained using the same formulation and method as Dispersion 1 except that 14.0 parts of Red No. 81) manufactured by Dainichiseika Co., Ltd. was used.
<Ink 8>
Ink 8 was obtained using the same formulation and method as for Ink 3 of Example 3, except that Dispersion 1 in Ink 3 of Example 3 was changed to Dispersion 2.

[Example 9]
<Dispersion 3>
14.0 parts of the quinacridone pigment (mixed crystal pigment of CI Pigment Red 202 and Pigment Violet 19, Cinquasia Magenta D4500J manufactured by BASF) in Dispersion 1 of Example 1 is added to the quinacridone pigment (CI Pigment Violet 19, Dispersion 3 was obtained using the same formulation and method as Dispersion 1 except that 14.0 parts of Ink Jet MAGENTA E5B (manufactured by Clariant Japan) was used.
<Ink 9>
Ink 9 was obtained using the same formulation and method as for Ink 3 of Example 3, except that Dispersion 1 in Ink 3 of Example 3 was changed to Dispersion 3.

[Example 10]
<Dispersion 4>
14.0 parts of the quinacridone pigment (C.I. Pigment Red 202 and Pigment Violet 19 mixed crystal pigment, Cinquasia Magenta D4500J manufactured by BASF) in Dispersion 1 of Example 1 was mixed with quinacridone pigment (C.I. Pigment Red 122 and Dispersion 4 was obtained using the same formulation and method as Dispersion 1 except that 14.0 parts of mixed crystal pigment Pigment Violet 19 (FASTGEN SUPER Magenta RE-05 manufactured by DIC) was used.
<Ink 10>
Ink 10 was obtained using the same formulation and method as for Ink 3 of Example 3, except that Dispersion 1 in Ink 3 of Example 3 was changed to Dispersion 4.

[Example 11]
<Dispersion 5>
14.0 parts of the quinacridone pigment (mixed crystal pigment of C.I. Pigment Red 202 and Pigment Violet 19, Cinquasia Magenta D4500J manufactured by BASF) in Dispersion 1 of Example 1 was added to azo pigments (C.I. Pigment Red 184, Dispersion 5 was obtained using the same formulation and method as Dispersion 1 except that Naphtol Carmine 6B) (manufactured by Cappelle Pigment NV) was changed to 14.0 parts.
<Ink 11>
Ink 11 was obtained using the same formulation and method as for Ink 3 of Example 3, except that Dispersion 1 in Ink 3 of Example 3 was changed to Dispersion 5.

[Example 12]
<Dispersion 6>
14.0 parts of the quinacridone pigment (mixed crystal pigment of C.I. Pigment Red 202 and Pigment Violet 19, Cinquasia Magenta D4500J manufactured by BASF) in Dispersion 1 of Example 1 was added to azo pigments (C.I. Pigment Red 150, Dispersion 6 was obtained using the same formulation and method as Dispersion 1, except that 14.0 parts of Fuji Pigment Red 150) was used.
<Ink 12>
Ink 12 was obtained using the same formulation and method as for Ink 3 of Example 3, except that Dispersion 1 in Ink 3 of Example 3 was changed to Dispersion 6.

[Example 13]
<Ink 13>
Dispersion 1 36.0 parts 3-ethyl-3-hydroxymethyloxetane 5.0 parts 3-methyl-1,3-butanediol 10.0 parts 1,2 - Propanediol ... 10.0 parts 2-Ethyl-1,3-hexanediol ... 2.0 parts Polyoxyethylene polyoxypropylene alkyl ether ... 1.0 parts (Emulgen LS-106, manufactured by Kao Corporation)
・ Urethane resin emulsion ... 12.5 parts (Takelac W-6110, manufactured by Mitsui Chemicals, Inc., 32.0% aqueous dispersion)
· 2-amino-2-ethyl-1,3-propanediol ... 0.5 parts · Antiseptic and antifungal agent ... 0.1 parts (Proxel LV, manufactured by Arch Chemicals Japan)
Ion-exchanged water...22.9 parts After dissolving the components other than Dispersion 1 in ion-exchanged water to prepare a vehicle, mixing with Dispersion 1 and filtering through a filter with an average pore size of 1 μm, the ink is obtained. 13 was obtained.

[Example 14]
<Ink 14>
Dispersion 1 36.0 parts 3-ethyl-3-hydroxymethyloxetane 5.0 parts 3-methyl-1,3-butanediol 10.0 parts 1,2 - Propanediol ... 10.0 parts 2-Ethyl-1,3-hexanediol ... 2.0 parts Polyoxyethylene polyoxypropylene alkyl ether ... 1.0 parts (Emulgen LS-106, manufactured by Kao Corporation)
- Acrylic resin emulsion ... 10.0 parts (NANOCLYL-S KPX, manufactured by Toyochem Co., Ltd., 40.0% aqueous dispersion) - 2-amino-2-ethyl-1,3-propanediol ... 0.0 parts. 5 parts antiseptic antifungal agent ... 0.1 part (Proxel LV, manufactured by Arch Chemicals Japan)
Ion-exchanged water...25.4 parts After dissolving the components other than Dispersion 1 in ion-exchanged water to prepare a vehicle, mixing with Dispersion 1 and filtering through a filter with an average pore size of 1 μm, the ink is obtained. 14 was obtained.

[Example 15]
In ink 3 of Example 3, except that 1.0 part of polyethylene wax (AQUACER531, manufactured by BYK, 45.0% aqueous dispersion) was added and the amount of deionized water was changed from 30.4 parts to 29.4 parts. Ink 15 was obtained using the same formulation and method as in Example 3.

[Example 16]
In ink 3 of Example 3, except that 1.0 parts of the polyether-modified siloxane compound represented by the above formula (2-2) was added and the amount of ion-exchanged water was changed from 30.4 parts to 29.4 parts. Using the same formulation and method as in Example 3, Ink 16 was obtained.

[Example 17]
In Ink 1 of Example 1, 1.0 parts of 3-ethyl-3-hydroxymethyloxetane was changed to 7.8 parts, and 19.0 parts of 3-methyl-1,3-butanediol was changed to 12.2 parts. Ink 17 was obtained using the same formulation and method as in Example 1, except for the above.

[Example 18]
In Ink 1 of Example 1, 1.0 parts of 3-ethyl-3-hydroxymethyloxetane was changed to 8.5 parts, and 19.0 parts of 3-methyl-1,3-butanediol was changed to 11.5 parts. Ink 18 was obtained using the same formulation and method as in Example 1, except for the above.

[Example 19]
In Ink 1 of Example 1, 1.0 parts of 3-ethyl-3-hydroxymethyloxetane was changed to 9.8 parts, and 19.0 parts of 3-methyl-1,3-butanediol was changed to 10.2 parts. Ink 19 was obtained using the same formulation and method as in Example 1, except for the above.

[Comparative Example 1]
In Ink 3 of Example 3, 5.0 parts of 3-ethyl-3-hydroxymethyloxetane was changed to 12.0 parts, and 15.0 parts of 3-methyl-1,3-butanediol was changed to 8.0 parts. Ink 20 was obtained using the same formulation and method as in Example 3, except for the above.

[Comparative Example 2]
Ink 21 was obtained using the same formulation and method as in Example 3, except that in Ink 3 of Example 3, 5.0 parts of 3-ethyl-3-hydroxymethyloxetane was changed to 5.0 parts of 2-pyrrolidone. rice field.

[Comparative Example 3]
Ink 22 was obtained using the same formulation and method as in Example 3, except that 5.0 parts of 3-ethyl-3-hydroxymethyloxetane in Ink 3 of Example 3 was changed to 5.0 parts of glycerin.

[Comparative Example 4]
<Dispersion 7>
In Dispersion 1 of Example 1, 1.0 parts of <quinacridone derivative mixture>, which is a mixture of the compound represented by the above formula (1-1) and the compound represented by formula (1-2), was not added, Quinacridone pigment (mixed crystal pigment of CI Pigment Red 202 and Pigment Violet 19, Cinquasia Magenta D4500J manufactured by BASF) 14.0 parts was changed to 15.0 parts, the same formulation and method as Dispersion 1 to obtain Dispersion 7.
<Ink 23>
Ink 23 was obtained using the same formulation and method as in Example 3, except that Dispersion 1 was changed to Dispersion 7 in Ink 3 of Example 3.

なお、粘度の測定には、粘度計（ＲＥ８０Ｌ、東機産業社製）を使用し、５０回転又は１００回転で２５℃における粘度を測定した。評価結果を表３に示す。
［評価基準］
Ａ：粘度の変化率が±５％以内
Ｂ：粘度の変化率が±５％を超え、±１０％以内
Ｃ：粘度の変化率が±１０％を超え、±３０％以内
Ｄ：粘度の変化率が±３０％を超える（ゲル化して評価不能） <Ink Storage Stability>
Each ink was filled in an ink cartridge and stored at 70° C. for 14 days, and the rate of change in viscosity after storage relative to viscosity before storage was obtained from the following formula and evaluated according to the following criteria.

For viscosity measurement, a viscometer (RE80L, manufactured by Toki Sangyo Co., Ltd.) was used, and the viscosity was measured at 25° C. at 50 or 100 rotations. Table 3 shows the evaluation results.
[Evaluation criteria]
A: Viscosity change rate within ±5% B: Viscosity change rate exceeding ±5% and within ±10% C: Viscosity change rate exceeding ±10% and within ±30% D: Viscosity change Rate exceeds ±30% (cannot be evaluated due to gelation)

<Ink ejection device>
A commercially available inkjet printer (IPSiO GX-e5500 manufactured by Ricoh Co., Ltd.) was set with the inks prepared in Examples and Comparative Examples, and an operation was performed to print 1000 sheets of a print chart with a print area of 5%. After a rest period of 24 hours from the end of printing, the following <discharge stability>, <chroma>, <beading>, and <drying properties> were evaluated. Evaluation criteria are shown below. Table 3 shows the results.

<Ejection stability>
Using the ink ejection device, droplets were discharged from all the nozzles for 1 hour.
After 1 hour, a nozzle check pattern was printed on glossy inkjet paper (Gassai Photofinishing Value, manufactured by FUJIFILM Corporation), and the number of ejection nozzles that ejected ink out of the total number of 384 nozzles was confirmed. Evaluation was made according to the following criteria. Table 3 shows the results.
[Evaluation criteria]
A: The number of ejection nozzles is 384 (all nozzles ejection)
B: The number of ejection nozzles is 368 or more (a level that poses no problems in actual use)
C: The number of discharge nozzles is 192 or more and less than 368 D: The number of discharge nozzles is less than 192

<Saturation>
A solid image of 5 cm x 5 cm was formed on a recording medium (OK top coat + rice basis weight of 104.7 g/m ² (manufactured by Oji Paper Co., Ltd.)) with a pixel density of 1200 dpi x 1200 dpi, and the internal temperature was adjusted to 100°C. The printed part was dried for 30 seconds in the set constant temperature bath. Using a reflective color spectrophotometric densitometer (manufactured by X-Rite), the values of L*a*b* are measured, and the C ^* value is calculated from the measured values of a* and b*, and the following evaluation criteria are used. Based on the evaluation. Note that ranks A and B are within the allowable range.
〔Evaluation criteria〕
A: C ^* is 75 or more B: C ^* is 70 or more and less than 75 C: C ^* is 65 or more and less than 70 D: C ^* is less than 65

<Beading>
The beading of a solid image of 5 cm×5 cm formed using the same method as the <chroma> evaluation was visually confirmed and evaluated according to the following criteria.
〔Evaluation criteria〕
A: None (not visible from a distance of 15 cm)
B: There is very little
(Visible from a distance of 15 cm, but not visible from a distance of 50 cm)
C: Slightly
(Visible from a distance of 50cm, but not visible from a distance of 1m)
D: Strong (visible from a distance of 1m)

<Drying>
An unprinted paper (4 cm × 4 cm) was placed on a solid image of 5 cm × 5 cm formed using the same method as the <chroma> evaluation, and a 2 cm long × 2 cm wide × 0.2 cm thick image was placed on top of it. A rubber sheet was placed in the center of the paper, a weight was placed on the rubber sheet so that the pressure applied from the rubber sheet to the paper was 0.5 kgf/cm ² , and the paper was placed under an environment of 23°C and 50% RH for 12 hours. left for time. After standing, the superimposed papers were peeled off, and the state of transfer of the pigment to the unprinted paper was visually observed, and the transferability was evaluated according to the following evaluation criteria.
〔Evaluation criteria〕
A: Little transfer of pigment to paper, no sticking between papers B: Little transfer of pigment to paper, but sticking between papers C: Slight transfer to paper Pigment transfer is visible (less than 10% area transfer on the whole paper)
D: Clear transfer of pigment to paper is observed (transfer of 10% or more area of the entire paper)

400 Image forming apparatus 401 Exterior of image forming apparatus 401c Cover of apparatus main body 404 Cartridge holder 410 Main tank 410k, 410c, 410m, 410y For black (K), cyan (C), magenta (M), and yellow (Y) main tank 411 ink storage unit 413 ink discharge port 414 storage container case 420 mechanism unit 434 ejection head 436 supply tube

JP 2014-065872 A JP 2017-014150 A JP 2016-145313 A

Claims (14)

An ink containing a pigment, a quinacridone derivative represented by the following general formula (1), and a solvent A having an SP value of 9.0 or more and 11.0 or less, wherein the content of the solvent A is less than 10% by mass.

(In the formula, R ¹ , R ² , R ³ and R ⁴ represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms, and may be the same or different. Further, R ⁵ and R ⁶ are represents an alkyl group having 1 to 4 carbon atoms, which may be the same or different, m represents an integer of 1 to 2, and n represents an integer of 0 to 2.) 2. The ink according to claim 1, wherein the content of the solvent A is 2% by mass or more and 8% by mass or less. 3. The ink according to claim 1, wherein the content of the quinacridone derivative with respect to the pigment is 1% by mass or more and 10% by mass or less. The ink according to any one of claims 1 to 3, wherein the content of the quinacridone derivative in the ink is 0.01% by mass or more and 1.00% by mass or less with respect to the total amount of the ink. 5. The ratio of the content of the quinacridone derivative in the ink to the content of the solvent A (the quinacridone derivative/the solvent A) is 0.045 or more and 0.18 or less. ink. 6. The solvent A according to any one of claims 1 to 5, wherein the solvent A is at least one selected from 3-ethyl-3-hydroxymethyloxetane, isopropylideneglycerol and N,N-dimethyl-β-butoxypropionamide. ink. The ink according to any one of claims 1 to 6, wherein the pigment is a quinacridone pigment. The pigment is C.I. I. Pigment Red 122, C.I. I. Pigment Violet 19, C.I. I. Pigment Red 122 and C.I. I. Pigment Violet 19 mixed crystal, or C.I. I. Pigment Red 202 and C.I. I. 8. The ink according to any one of claims 1 to 7, which is a mixed crystal of Pigment Violet 19. 9. The ink according to any one of claims 1 to 8, wherein the ink further contains a resin emulsion, and the resin emulsion comprises an acrylic resin or a urethane resin. 10. The ink according to any one of claims 1 to 9, wherein said ink further contains polyethylene wax. 11. The ink according to any one of claims 1 to 10, further comprising a polyether-modified siloxane compound. An ink container containing the ink according to any one of claims 1 to 11. 13. An ink jet recording apparatus comprising: the ink container according to claim 12; and ejection means for ejecting ink supplied from the ink container. A recording method comprising an ink applying step of applying the ink according to any one of claims 1 to 11 to a recording medium.

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