JP7061287B2 - Ink, ink container, and inkjet recording device - Google Patents

Description

The present invention relates to ink, an ink container, and an inkjet recording device.

Inkjet printers have become remarkably popular due to their advantages such as low noise and low running cost, and color printers that can print on plain paper have also been actively introduced to the market. However, image color reproducibility, scratch resistance, durability, light resistance, image dryness, character bleeding (feathering), color boundary bleeding (color bleeding), double-sided printability, ejection stability, etc. are required. It is very difficult to satisfy all the characteristics, and the ink to be used is selected according to the characteristics that are prioritized according to the application.

The ink used for inkjet recording is generally composed of water as a main component and containing a colorant and a water-soluble solvent such as glycerin having water retention property for the purpose of preventing clogging. Dyes have been used as colorants because of their excellent color development and stability, but the light resistance and water resistance of images are not sufficient. The water resistance has been improved to some extent by improving the inkjet-dedicated recording paper having an ink absorbing layer, but the plain paper is not satisfactory.

Ink using a pigment as a colorant is used to make up for the drawbacks of plain paper, and although the light resistance and water resistance of the image are greatly improved, the fixing property of the image is poor as compared with the dye ink. For the purpose of compensating for this, a resin is added to the ink and the pigment is bound onto the plain paper. However, since the viscosity of the ink increases when the resin is added to the ink, it is necessary to take a method of suppressing the increase in the viscosity due to the addition of the resin by reducing the functional materials such as the water-soluble solvent and the penetrant contained in the ink. The current situation is that we cannot get it. If the amount of the water-soluble solvent is reduced, the ink dries easily, so that the ink dries around the nozzle, and the nozzle may be blocked by the pigment or resin, resulting in ejection bending or clogging of the nozzle, resulting in non-ejection. Further, if the penetrant is reduced, the spread of the ink droplets landed on the paper becomes poor, and the ink cannot cover the entire paper, resulting in a decrease in image density.

In recent years, it has been pointed out that inkjet images are inferior in image density and saturation on plain paper to images produced by other processes such as printing and electrophotographic. This is because inkjet uses low-viscosity ink, so after landing on the surface of plain paper, the ink penetrates between the fibers of the paper, and the amount of pigment present on the surface of the paper that contributes to color development is reduced. By doing so.

Therefore, it has been proposed to use commercial printing paper such as coated paper as a means for keeping the image on the paper surface without infiltrating the color material component made of pigment or resin into the inside of the paper. Although coated paper significantly improves color development compared to plain paper, the penetration of vehicle components into the paper is slow and the image dries slowly, resulting in surface tension and heat until the image dries. Due to the influence, it flows, causing a problem of uneven shading called beading. A method of adding a solvent having a low boiling point to the ink has been proposed in order to speed up the drying, but problems such as deterioration of the storage stability of the ink and sticking of the dried ink around the ejection head occur. Further, although a method of heating and drying immediately after printing has been proposed, there is a problem that the equipment becomes large by equipping the drying equipment.

As an ink for inkjet that has excellent continuous jetting property and also excellent optical density, bleeding, intercolor bleeding, and drying time, Patent Document 1 describes that it is used in combination with an ink flocculant when printing an image, and at least a coloring material. , One or more polymer surfactants, and one or more water-soluble solvents, the solubility parameter of the hydrophobic group moiety of any one of the polymer surfactants, and the water-soluble solvent. Inks are disclosed in which the solubility parameters of any one of the above and their contents satisfy a particular relationship. In the examples, an ink containing a pigment, a polymer compound, a polyoxyethylene 2-ethylhexyl ether, and a solvent having an SP value of 9.0 or more and 11.0 or less is disclosed. However, regarding polymer compounds, there is no description regarding the mass ratio of their structural units.

An object of the present invention is to provide an ink having excellent storage stability and ejection stability, and to provide an ink capable of recording good quality with high drying property and suppressed beading.

The above problem is solved by the following invention <1>.
<1> A coloring material, a polymer compound, a compound represented by the following general formula (1), and a solvent S having an SP value of 9.0 or more and 11.0 or less are contained.
The polymer compound is a polymer compound having a structural unit derived from a vinyl monomer (A) having an aromatic group and a structural unit derived from a monomer (B) which is (meth) acrylic acid or an ester thereof. The ratio B / A (mass ratio) of the structural unit derived from the (meth) acrylic acid or the monomer (B) which is an ester thereof to the structural unit derived from the vinyl monomer (A) having an aromatic group is 0. .20 to 0.60,
An ink in which the content of the solvent S in the ink is 10% by mass or less.
However, in the general formula (1), R represents an alkyl group having 8 to 13 carbon atoms, R ₁ represents a hydrogen atom or a methyl group, and n represents an integer of 2 to 12.

According to the present invention, it is possible to provide an ink having excellent storage stability and ejection stability, and to provide an ink having high drying property and capable of recording good quality with suppressed beading.

It is a perspective view schematically showing an example of the recording apparatus which concerns on this invention. It is a perspective view which shows typically an example of the ink container which concerns on this invention.

＜５＞前記インクが更に下記一般式（３）で表される化合物を含有する＜１＞から＜４＞のいずれかに記載のインク。
ただし、一般式（３）中、ｍ＝０～７、ｋ＝２～１５である。

＜６＞前記インクが更にポリエチレンワックスを含有する＜１＞から＜５＞のいずれかに記載のインク。
＜７＞＜１＞から＜６＞のいずれかに記載のインクを容器中に収容してなるインク収容容器。
＜８＞＜７＞に記載のインク収容容器と、前記インク収容容器から供給されるインクを吐出する吐出手段とを有するインクジェット記録装置。 Hereinafter, the present invention <1> will be described in detail, but the following <2> to <8> are also included in the embodiments thereof, and these will also be described.
<2> The ink according to <1>, wherein the solvent S contains at least one selected from 3-ethyl-3-hydroxymethyloxetane, isopropylideneglycerol and N, N-dimethyl-β-butoxypropionamide.
<3> The ink according to <1> or <2>, wherein the content of the solvent S in the ink is 3% by mass or more and 7% by mass or less.
<4> The structural unit derived from the vinyl monomer (A) having an aromatic group of the polymer compound is any one of <1> to <3>, which is a structural unit represented by the following general formula (2). The inks listed.
However, in the formula, R2 is a hydrogen atom or a methyl group, and L is an alkylene group having 2 to 18 carbon atoms.

<5> The ink according to any one of <1> to <4>, wherein the ink further contains a compound represented by the following general formula (3).
However, in the general formula (3), m = 0 to 7 and k = 2 to 15.

<6> The ink according to any one of <1> to <5>, wherein the ink further contains polyethylene wax.
<7> An ink container for containing the ink according to any one of <1> to <6>.
<8> An inkjet recording apparatus comprising the ink container according to <7> and an ejection means for ejecting ink supplied from the ink container.

Printing water-based inkjet inks containing pigments and polymer compounds on coated paper has the problem of beading on solid images, but beading is a phenomenon that occurs when images dry slowly. It is known, and it is necessary to devise ways to increase the penetration rate into the paper.
Penetration in coated paper is performed through ventilation holes (several nm) in the coat layer, but pigment particles in which polymer compounds are adsorbed on the surface of the ink and resin emulsions, which are aggregates of polymer compounds, are used. It is considered to be large compared to the size of the vent (several tens of nm to 200 nm) and will not block the vent. On the other hand, pigment particles on which the polymer compound is adsorbed on the surface or a state in which the polymer compound is separated on a molecular basis from the resin emulsion is called a "free polymer compound" and has the same size as the opening diameter of the vent. Due to its size, it closes the opening and prevents the vehicle components (components other than coloring materials and resins) from penetrating into the support layer made of cellulose fibers under the coat layer, which makes the image dry and beading. Is thought to occur.

Since the solvent S having an SP value of 9.0 to 11.0 has a high permeation rate and can permeate into the support layer before the ventilation holes are closed, beading can be suppressed. However, the solvent S tends to deteriorate the storage stability and the discharge stability, and cannot be added in a large amount, and the appropriate amount is 10% by mass or less. However, if it is 10% by mass or less, the permeation rate cannot be said to be sufficient.
The compound represented by the general formula (1) is a surfactant, has a function of preventing the liberated polymer compound from closing the ventilation holes, and can suppress beading. However, since it is particularly easily dissolved in the solvent S having an SP value of 9.0 to 11.0, both the solvent S and the general formula (1) are shared in order to obtain a good image without beading on the coated paper. There is a need to.

<Ink>
Hereinafter, the organic solvent, water, coloring material, resin, additive, etc. used for the ink will be described.

<Color material>
The coloring material is not particularly limited, and pigments and dyes can be used.
As the pigment, an inorganic pigment or an organic pigment can be used. These may be used alone or in combination of two or more. Further, a mixed crystal may be used.
As the pigment, for example, a black pigment, a yellow pigment, a magenta pigment, a cyan pigment, a white pigment, a green pigment, an orange pigment, a glossy color pigment such as gold or silver, a metallic pigment, or the like can be used.
As inorganic pigments, carbon black produced by known methods such as contact method, furnace method, thermal method, in addition to titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, and chrome yellow. Can be used.
Examples of organic pigments include azo pigments and polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, quinophthalone pigments, etc.). , Dye chelate (for example, basic dye type chelate, acid dye type chelate, etc.), nitro pigment, nitroso pigment, aniline black and the like can be used. Among these pigments, those having a good affinity with a solvent are preferably used. In addition, resin hollow particles and inorganic hollow particles can also be used.
As a specific example of the pigment, for black, carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, or copper, iron (CI pigment black 11) , Metals such as titanium oxide, and organic pigments such as aniline black (CI pigment black 1).
Further, for color, C.I. I. Pigment Yellow 1, 3, 12, 13, 14, 17, 24, 34, 35, 37, 42 (yellow iron oxide), 53, 55, 74, 81, 83, 95, 97, 98, 100, 101, 104 , 108, 109, 110, 117, 120, 138, 150, 153, 155, 180, 185, 213, C.I. I. Pigment Orange 5, 13, 16, 17, 36, 43, 51, 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 Calcium 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81, 83, 88, 101 (Bengara), 104, 105, 106, 108 ( Cadmium Red), 112, 114, 122 (Quinacridone Magenta), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 184, 185, 190, 193, 202, 207, 208, 209, 213, 219, 224, 254, 264, mixed crystal (Pigment Red 122 / Pigment Violet 19), mixed crystal (Pigment Red 202 / Pigment Violet 19), C.I. I. Pigment Violet 1 (Rhodamine Lake), 3, 5: 1, 16, 19, 23, 38, C.I. I. Pigment Blue 1, 2, 15 (phthalocyanine blue), 15: 1, 15: 2, 15: 3, 15: 4 (phthalocyanine blue), 16, 17: 1, 56, 60, 63, C.I. I. Pigment Greens 1, 4, 7, 8, 10, 17, 18, 36, etc.
The dye is not particularly limited, and acid dyes, direct dyes, reactive dyes, and basic dyes can be used, and one type may be used alone or two or more types may be used in combination.
As the dye, for example, C.I. I. Acid Yellow 17, 23, 42, 44, 79, 142, C.I. I. Acid Red 52,80,82,249,254,289, C.I. I. Acid Blue 9,45,249, C.I. I. Acid Black 1,2,24,94, C.I. I. Hood Black 1, 2, C.I. I. Direct Yellow 1,12,24,33,50,55,58,86,132,142,144,173, C.I. I. Direct Red 1,4,9,80,81,225,227, C.I. I. Direct Blue 1,2,15,71,86,87,98,165,199,202, C.I. I. Dilekdo Black 19,38,51,71,154,168,171,195, C.I. I. Reactive Red 14, 32, 55, 79, 249, C.I. I. Reactive Black 3, 4, 35 can be mentioned.

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 viewpoint of improving the image density, good fixing property and ejection stability. It is as follows.

As a method of dispersing the pigment to obtain an ink, a method of introducing a hydrophilic functional group into the pigment to obtain a self-dispersible pigment, a method of coating the surface of the pigment with a resin and dispersing it, and a method of dispersing using a dispersant are used. The method, etc. can be mentioned.
As a method of introducing a hydrophilic functional group into a pigment to obtain a self-dispersing pigment, for example, a method of adding a functional group such as a sulfone group or a carboxyl group to a pigment (for example, carbon) so that the pigment can be dispersed in water. Can be mentioned.
Examples of the method of coating the surface of the pigment with a resin and dispersing the pigment include a method of encapsulating the pigment in microcapsules so that the pigment can be dispersed in water. This can be rephrased as a resin-coated pigment. In this case, it is not necessary that all the pigments blended in the ink are coated with the resin, and the uncoated pigments and the partially coated pigments are dispersed in the ink as long as the effect of the present invention is not impaired. May be.
Examples of the method of dispersing using a dispersant include a method of dispersing using a known low-molecular-weight dispersant and high-molecular-weight dispersant represented by a surfactant.
As the dispersant, for example, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant and the like can be used depending on the pigment.
As the dispersant, RT-100 (nonionic surfactant) manufactured by Takemoto Oil & Fat Co., Ltd. and a naphthalene sulfonic acid Na formalin condensate can also be suitably used as the dispersant.
The dispersant may be used alone or in combination of two or more.

<Pigment dispersion>
It is possible to obtain an ink by mixing a material such as water or an organic solvent with a pigment. It is also possible to produce an ink by mixing a material such as water or an organic solvent with a pigment dispersion obtained by mixing a pigment and other water or a dispersant.
The pigment dispersion is obtained by mixing and dispersing water, a pigment, a pigment dispersant, and other components as necessary, and adjusting the particle size. It is good to use a disperser for dispersion.
The particle size of the pigment in the pigment dispersion is not particularly limited, but the maximum frequency is 20 nm or more in terms of the maximum number because the dispersion stability of the pigment is good and the image quality such as ejection stability and image density is also high. It is preferably 500 nm or less, and more preferably 20 nm or more and 150 nm or less. The particle size of the pigment can be measured using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrac Bell Co., Ltd.).
The content of the pigment in the pigment dispersion is not particularly limited and may be appropriately selected depending on the intended purpose, but is 0.1% by mass from the viewpoint of obtaining good ejection stability and increasing the image density. 50% by mass or more is preferable, and 0.1% by mass or more and 30% by mass or less is more preferable.
It is preferable to degas the pigment dispersion by filtering the coarse particles with a filter, a centrifuge, or the like, if necessary.

<Solvent S with SP value of 9.0 or more and 11.0 or less>
The ink of the present invention contains at least one solvent S 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 into commercial printing paper such as coated paper having a coating layer and having poor ink absorption, and it becomes 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。例えば、イソプロピリデングリセロール（ｉＰＤＧ）のＳＰ値は、下記表１の値より次のように計算される。
ＳＰ値＝（１４１５０／１３９．８）^1/2＝１０．１ （cal/cm³）^1/2
となる。 The SP value is a dissolution parameter, and is generally widely used as an index of affinity and solubility of a material such as a solvent, a resin, or a pigment, which is dissolved or dispersed in water or a solvent. 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. In the present invention, Fedors proposed. A method calculated 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 the difference between the measured value by the experiment is small. In the Fedors method, the evaporation energy Δe _i and the molar volume Δvi _i at 25 ° C. of each atom or atomic group are determined as shown in the table below, and the SP value can be obtained by substituting these values into the equation (1). .. In the present invention, the SP value at 25 ° C. is used, and temperature conversion or the like is not performed.

In the formula (1), ΔE: aggregation energy density, V: molar volume, Δe _i : evaporation energy of atom or atomic group, Δv _i : molar volume of atom or atomic group. For example, the SP value of isopropyrideneglycerol (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
Will be.

The solvent S is preferably water-soluble, and is preferably 3-ethyl-3-hydroxymethyloxetane (SP value: 10.7), isopropyrideneglycerol (SP value: 10.1), N, N-dimethyl-β-. Butoxypropionamide (SP value: 9.8), tripropylene glycol monomethyl ether (SP value: 9.4), methyltriglycol (SP value: 10.1), N, N-dimethyl-β-methoxypropionamide (SP value: 10.1) SP value: 10.3), 3-methoxy-1-butanol (SP value: 10.0), dipropylene glycol monopropyl ether (SP value: 9.5) and the like, and in particular 3-ethyl-3- Hydroxylmethyloxetane, isopropylideneglycerol and N, N-dimethyl-β-butoxypropionamide are preferred.

An organic solvent having an SP value of less than 9.0 cannot be used for a water-based ink as in the present invention because its solubility in water is generally very low and separation is likely to occur.
The SP value is a value defined by the regular solution theory introduced by Hildebrand, and is a measure of the solubility of a two-component solution. The SP value in the present invention is a value calculated by the Fedors method. It is expressed by the square root of the cohesive energy density in the regular solution theory, and the unit is (cal / cm ³ ) ^1/2 . It can be calculated with popular simple software.

The content of the solvent S having an SP value of 9.0 or more and 11.0 or less is preferably 10% by mass or less, more preferably 3% by mass or more and 7% by mass or less of the entire ink. When the content is 3% by mass or more, the beading suppressing effect on commercial printing paper can be sufficiently obtained. Further, when the content is 7% by mass or less, the ejection stability does not deteriorate due to the increase in the viscosity of the ink.

<Polymer compound>
The polymer compound that can be used in the present invention has a structural unit derived from a vinyl monomer (A) having an aromatic group and a structural unit derived from a monomer (B) that is (meth) acrylic acid or an ester thereof. It is a polymer compound that has. Since the structural unit derived from the vinyl monomer (A) exhibits hydrophobicity and the structural unit derived from the monomer (B) which is (meth) acrylic acid or an ester thereof exhibits hydrophilicity, the ratio of structural units B / A ( When the mass ratio) is smaller than 0.20, the hydrophobicity is strong and the dispersibility in the water-based ink vehicle is deteriorated, so that the storage stability and the ejection stability are deteriorated. On the other hand, if the B / A is larger than 0.60, the hydrophilicity is strong and it dissolves in the water-based ink vehicle. Therefore, the liberated polymer blocks the ventilation holes (several nm) in the coat layer for beading. Will get worse. In the present invention, by setting the B / A to 0.20 to 0.60, the storage stability and ejection stability of the ink are good, and a good image with less beading can be obtained.

（メタ）アクリル酸またはそのエステルであるモノマー（Ｂ）に由来する構造単位としては、（メタ）アクリル酸またはそのエステルであるモノマー（Ｂ）が、アクリル酸、メタクリル酸、であることが好ましい。 As the structural unit derived from the vinyl monomer (A) having an aromatic group, a structural unit derived from styrene, benzyl acrylate, benzyl methacrylate, and a structural unit represented by the following general formula (2) are preferable, and the following general formula is used. It is more preferable that the structural unit is represented by (2).
However, in the formula, R2 is a hydrogen atom or a methyl group, and L is an alkylene group having 2 to 18 carbon atoms.

As the structural unit derived from the monomer (B) which is (meth) acrylic acid or an ester thereof, it is preferable that the monomer (B) which is (meth) acrylic acid or an ester thereof is acrylic acid or methacrylic acid.

In the ink, other than the polymer compound having the structural unit derived from the vinyl monomer (A) having an aromatic group and the structural unit derived from the monomer (B) which is (meth) acrylic acid or an ester thereof. The polymer compound may be contained, and the type thereof is not particularly limited and may be appropriately selected depending on the intended purpose. For example, urethane resin, polyester resin, acrylic resin, vinyl acetate resin, styrene resin, etc. Examples thereof include resins, butadiene resins, styrene-butadiene resins, vinyl chloride resins, acrylic styrene resins, and acrylic silicone resins.
These polymer compounds are added to the ink as a pigment dispersant, as a fixing resin, or in a form having the functions of a pigment dispersant and a fixing resin. When added to the ink as a fixing resin, the resin particles may be added to the ink in the form of a resin emulsion in which water is used as a dispersion medium. As the resin particles, those synthesized as appropriate may be used, or commercially available products may be used. Further, these may be used alone or in combination of two or more kinds of resin particles.
The composition and ratio of the structure of the polymer compound contained in the ink can be known by, for example, specifying the composition of the monomer by GC-MASS and then separating the peaks derived from each monomer by NMR.

The volume average particle size of the resin particles is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of obtaining good fixability and high image hardness, 10 nm or more and 1,000 nm or less are preferable. More than 200 nm is more preferable, and 10 nm or more and 100 nm or less is particularly preferable.
The volume average particle size can be measured using, for example, a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrac Bell Co., Ltd.).

The content of the resin is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of fixability and storage stability of the ink, 1% by mass or more and 30% by mass or less with respect to the total amount of the ink. Is preferable, and 5% by mass or more and 20% by mass or less is more preferable.

<Resin emulsion>
As a resin emulsion, one having excellent film-forming property (image forming property), high water repellency, high water resistance, and high weather resistance is used for image recording with high water resistance and high image density (high color development). It is useful, and examples thereof include condensation-based synthetic resins, addition-based synthetic resins, and natural polymer compounds.
Examples of the condensation-based synthetic resin include polyester resin, polyurethane resin, polyepoxy resin, polyamide resin, polyether resin, poly (meth) acrylic resin, acrylic-silicone resin, and fluororesin. Examples of the additive synthetic resin include a polyolefin resin, a polystyrene resin, a polyvinyl alcohol resin, a polyvinyl ester resin, a polyacrylic acid resin, an unsaturated carboxylic acid resin and the like. Examples of the natural polymer compound include celluloses, rosins, and natural rubbers. Further, as the resin emulsion, one in which the resin itself has a hydrophilic group and has self-dispersity can be used, and one in which the resin itself does not have dispersibility and is imparted with dispersibility by a surfactant or a resin having a hydrophilic group can be used. Among these, acrylic resin or urethane resin is particularly preferable, and two or more of the above resin emulsions may be used in combination.
In the case of emulsion polymerization of unsaturated monomer, the resin emulsion is formed by reacting in water containing unsaturated monomer, polymerization initiator, surfactant, chain transfer agent, chelating agent, pH adjuster and the like. Therefore, the water-dispersible resin can be easily obtained, the resin composition can be easily changed, and the desired properties can be easily obtained.

The pH of the resin emulsion is preferably 4 to 12, because the molecular chain breakage such as dispersion fracture and hydrolysis is caused under strong alkaline and strong acid conditions, and the pH is particularly preferably 6 from the viewpoint of miscibility with the water-dispersible colorant. ~ 11 is more preferable, and 7 to 10 is even more preferable.
The average particle size (D50) of the resin emulsion is related to the viscosity of the dispersion liquid, and in the case of the same composition, the smaller the particle size, the larger 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 viscosity does not become excessively high when inked. Further, when the particle size is several tens of μm, it cannot be used because it becomes larger than the nozzle opening of the inkjet head. If particles with a large particle diameter are present in the ink even if they are smaller than the nozzle opening, the ejection property is deteriorated. Therefore, the average particle diameter (D50) is more preferably 200 nm or less, and further 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 on the paper surface, 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 becomes strong and the printed matter is tacked. Therefore, the glass transition temperature is preferably −30 ° C. or higher.
The content of the resin emulsion in the ink is preferably 0.5 to 10% by mass, more preferably 1 to 8% by mass in terms of solid content.

<Surfactant>
The ink of the present invention contains a compound represented by the above general formula (1), which is a surfactant.
As the surfactant, any of a nonionic surfactant, an anionic surfactant, a silicone-based surfactant, a fluorine-based surfactant, and an amphoteric surfactant can be used in combination.

ただし、一般式（１）中、Ｒは炭素数８～１３のアルキル基を示し、Ｒ₁は水素原子又はメチル基を示し、ｎは２～１２の整数を示す。
一般式（１）で表される化合物は界面活性剤であり、インクの表面張力を下げる浸透剤としての機能を有する。一般式（１）のＲ部分が疎水基、ｎのカッコ内部分が親水基として働き、親水部分がｎ＝１２よりも多い場合、あるいは逆に疏水部分Ｒの炭素数が８よりも小さい場合には、一般式（１）の親水性が強くなることでインクの表面張力が高くなり、吐出に悪影響を与えることがある。
一般式（１）で表される化合物は、インク中０．００１質量％以上５質量％以下含有されることが好ましく、０．１質量％以上０．５質量％以下含有されることがより好ましい。 <Nonion-based surfactant>
Examples of the nonionic surfactant include polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ester, polyoxypropylene alkyl ester, polyoxyethylene alkyl amine, polyoxyethylene alkyl amide, polyoxyethylene propylene block polymer, and sorbitan fatty acid. Examples thereof include esters, polyoxyethylene sorbitan fatty acid esters, and polyethylene oxide adducts of acetylene alcohols.
The ink of the present invention contains the polyoxyethylene alkyl ester of the general formula (1), has a feature of high surface tension and less foaming as compared with other surfactants, and has an effect of suppressing the occurrence of beading. Is obtained. The surfactants of structural formulas (1) -1 to (1) -4 shown in Table 2 can be used particularly usefully.

However, in the general formula (1), R represents an alkyl group having 8 to 13 carbon atoms, R ₁ represents a hydrogen atom or a methyl group, and n represents an integer of 2 to 12.
The compound represented by the general formula (1) is a surfactant and has a function as a penetrant for lowering the surface tension of the ink. When the R portion of the general formula (1) acts as a hydrophobic group, the portion in parentheses of n acts as a hydrophilic group, and the hydrophilic portion is more than n = 12, or conversely, the carbon number of the water-sucking portion R is smaller than 8. The increase in hydrophilicity of the general formula (1) increases the surface tension of the ink, which may adversely affect ejection.
The compound represented by the general formula (1) is preferably contained in the ink in an amount of 0.001% by mass or more and 5% by mass or less, and more preferably 0.1% by mass or more and 0.5% by mass or less. ..

<Silicone-based surfactant>
A polyether-modified siloxane compound can also be used as the surfactant. As a result, the ink is hard to get wet with the ink-repellent layer of the head nozzle plate, the ejection failure due to the adhesion of the ink nozzles is prevented, and the ejection stability is improved. In addition, the ink is less likely to adhere to the nozzle ink-repellent layer surface, which tends to be a problem, and the ink is less likely to cause ejection defects. Among them, those represented by the following general formula (3) are preferable, and in particular, the dispersion stability is not impaired by the type of water-dispersible coloring material and the combination of organic solvents, the dynamic surface tension is low, and the permeability and leveling property are low. Higher is preferable. These polyether-modified siloxane compounds may be used alone or in combination of two or more.
Of these, those that do not decompose even at high pH are preferable, and examples thereof include side chain modified polydimethylsiloxane, double-ended modified polydimethylsiloxane, single-ended modified polydimethylsiloxane, side chain double-ended modified polydimethylsiloxane, and the like. Those having an oxyethylene group and a polyoxyethylene polyoxypropylene group are particularly preferable because they exhibit good properties as an aqueous surfactant. Further, 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 Si portion side chain of dimethylsiloxane.

As commercially available polyether-modified siloxane compound surfactants, 71ADDITIVE, 74ADDITIVE, 57ADDITIVE, 8029ADDITIVE, 8054ADDITIVE, 8211ADDITIVE, 8019ADDITIVE, 8526ADDITIVE, FZ-2123, FZ-2123, FZ-2123, FZ-2 TSF4440, TSF4441, TSF4445, TSF4446, TSF4450, TSF4452, TSF4460, Silface SAG002, Silface SAG003, Silface SAG005, Silface SAG503A, Silface SAG008, Silface, manufactured by Materials. SJM003, TEGO_Wet_KL245, TEGO_Wet_250, TEGO_Wet_260, TEGO_Wet_265, TEGO_Wet_270, TEGO_Wet_280, Big Chemie Japan, BYK-345, BYK-347, BYK-347

ただし、一般式（３）中、ｍ＝０～７、ｋ＝２～１５である。 In the present invention, it is particularly preferable to use the polyether-modified siloxane compound represented by the general formula (3). The structural formula (3) -1 or the structural formula (3) -2 shown in Table 3 can be used particularly usefully.

However, in the general formula (3), m = 0 to 7 and k = 2 to 15.

Examples of the fluorosurfactant include a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic acid compound, a perfluoroalkyl phosphate ester compound, a perfluoroalkyl ethylene oxide adduct, and a perfluoroalkyl ether group in the side chain. Polyoxyalkylene ether polymer compounds are particularly preferred because they have low foaming properties. Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid and perfluoroalkyl sulfonic acid salt. Examples of the perfluoroalkylcarboxylic acid compound include perfluoroalkylcarboxylic acid and perfluoroalkylcarboxylic acid salt. The polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain includes a sulfate ester salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain and a perfluoroalkyl ether group in the side chain. Examples thereof include salts of polyoxyalkylene ether polymers. The counter ions of the salts in these fluorine-based surfactants include Li, Na, K, NH ₄ , NH ₃ CH ₂ CH ₂ OH, NH ₂ (CH ₂ CH ₂ OH) ₂ , and NH (CH ₂ CH ₂ OH). ₃ etc. can be mentioned.

Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, lauryl salt, polyoxyethylene alkyl ether sulfate salt and the like.

Examples of the amphoteric tenside include laurylaminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, and lauryl dihydroxyethyl betaine.

These may be used alone or in combination of two or more.
Further, if necessary, the above-mentioned polyether-modified siloxane compound surfactant may be used in combination with a fluorine-based surfactant, a silicone-based surfactant, an acetylene glycol or an acetylene alcohol-based surfactant.
The content of the surfactant in the ink is preferably 0.001 to 5% by mass, more preferably 0.5 to 3% by mass. If it is 0.001% by mass or more, the effect of adding the surfactant can be obtained. However, if it exceeds 5% by mass, the addition effect is saturated, so there is no point in increasing the amount.

<Water>
The content of water in the ink is not particularly limited and may be appropriately selected depending on the intended purpose, but from the viewpoint of ink drying property and ejection reliability, it is preferably 10% by mass or more and 90% by mass or less, and 20% by mass. % Or more and 60% by mass or less are more preferable.

<Wax>
The ink composition according to the present invention preferably contains a wax, and the wax may be either water-soluble or water-dispersible. The water-soluble wax can be used as a wax having a hydrophilic group such as a hydroxyl group, a carboxyl group, an ethylene oxide group and an amine group, and the water-dispersible wax can be mainly used as a wax emulsion.

Specifically, plant waxes such as carnauba wax, candelilla wax, honey wax, rice wax, and lanolin, animal waxes, paraffin waxes, microcrystallin waxes, polyethylene waxes, polypropylene waxes, polyethylene oxide waxes, petrolatums, and other petroleum waxes. , Montan wax, mineral wax such as ozokelite, carbon wax, hexist wax, polyethylene wax, synthetic wax such as stearate amide, natural / synthetic wax emulsion such as α-olephine / maleic anhydride copolymer, compounded wax, etc. Can be used alone or in admixture of multiple species. Further, other latex, colloidal solution, suspension and the like can also be used. In the present invention, polyethylene wax having good solubility and dispersibility in a water-soluble solvent is desirable.

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

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

The volume average particle size of the wax is preferably 200 nm or less, more preferably 20 nm to 150 nm. If it is 200 nm or less, good ejection can be obtained without being caught by the nozzle or the filter in the head.

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

<Other ingredients>
In addition to the above-mentioned components, various known additives may be added to the ink of the present invention, if necessary. Examples include organic solvents with SP values exceeding 11.0, defoaming agents (defoaming agents), pH regulators, antiseptic and antifungal agents, chelating reagents, rust inhibitors, antioxidants, UV absorbers, and oxygen. Examples include absorbents and light stabilizers.

（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。） <Organic solvent with SP value exceeding 11.0>
The ink of the present invention may contain an organic solvent having an SP value of more than 11.0 in addition to the solvent S as the organic solvent.
As the organic solvent having an SP value of more than 11.0, a general organic solvent used for ink can be used, and 3-methyl-1,3-butanediol (SP value: 12.1), 1, 2 -Propanediol (SP value: 13.5) or the like can be preferably used.
Further, a penetrant can be used as an organic solvent having an SP value of more than 11.0.
The penetrant has a structure in which the hydrophilic part and the water-sucking part are largely separated in the molecule, and is a substance having a function of lowering the surface tension and penetrating into details such as capillaries like a surfactant. ..
As the penetrant, at least one non-wetting polyol compound or glycol ether compound having 8 to 11 carbon atoms is preferable. Here, the non-wetting agent property means having a solubility of 0.2 to 5.0% by mass in water at 25 ° C. Among these penetrants, the 1,3-diol compound represented by the following general formula (7) is preferable, 2-ethyl-1,3-hexanediol [solubility: 4.2% (25 ° C.)], 2 , 2,4-trimethyl-1,3-pentanediol [solubility: 2.0% (25 ° C.)] is particularly preferable.

(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.)

Examples of other non-wetting agent-type polyol compounds 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-diol and other aliphatic diols.
The content of the penetrant in the ink is preferably 0.5 to 4% by mass, more preferably 1 to 3% by mass. When it is 0.5% by mass or more, the penetrating effect of the ink is obtained and the image quality is improved. Further, if it is 4% by mass or less, it is sufficiently dissolved 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 defoaming agent is used to suppress the foaming by adding a small amount to the ink. Here, foaming means that the liquid forms a thin film and wraps the air. Properties such as surface tension and viscosity of the ink are involved in the formation of this bubble. That is, a liquid having a high surface tension such as water is difficult to foam because a force is exerted to reduce the surface area of the liquid as much as possible. On the other hand, the high-viscosity and high-permeability ink tends to foam due to its low surface tension, and the foam generated by the viscosity of the solution is easily maintained and difficult to defoam.
Usually, the foam suppressant destroys the foam by locally lowering the surface tension of the foam film to destroy the foam, or by interspersing the foam suppressant insoluble in the foam liquid on the surface of the foam liquid. When a polyether-modified siloxane compound surfactant, which has an extremely strong function of lowering the surface tension, is used as a surfactant in the ink, the surface tension of the foam film is locally increased even if a defoaming agent by the former mechanism is used. Cannot be lowered. Therefore, an insoluble defoaming agent is used for the latter foaming liquid, but in this case, the stability of the ink is lowered by the insoluble defoaming agent in the solution.

<pH adjuster>
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 blended, and can be appropriately selected depending on the intended purpose.
Examples thereof include alcohol amines, alkali metal element hydroxides, ammonium hydroxides, phosphonium hydroxides, alkali metal carbonates, and the like.
If the pH is out of the range of 7 to 11, the amount of the ink jet head and the ink supply unit that are melted out is large, and problems such as deterioration, leakage, and ejection failure of the ink may occur.
Examples of the alcohol amines include diethanolamine, triethanolamine, 2-amino-2-ethyl-1,3 propanediol and the like.
Examples of the hydroxide of the alkali metal element include lithium hydroxide, sodium hydroxide, potassium hydroxide and the like.
Examples of the ammonium hydroxide include ammonium hydroxide and quaternary ammonium hydroxide.
Examples of the phosphonium hydroxide include quaternary phosphonium hydroxide.
Examples of the alkali metal carbonate include lithium carbonate, sodium carbonate, potassium carbonate and the like.

<Preservatives and fungicides>
Examples of the antiseptic / antifungal agent include sodium dehydroacetate, sodium sorbate, 2-pyridinethiol-1-oxide sodium, sodium benzoate, sodium pentachlorophenol and the like.

<Chelating reagent>
Examples of the chelating reagent include sodium ethylenediamine tetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediamine triacetate, sodium diethylenetriamine pentaacetate, sodium uramil diacetate and the like.

<Rust inhibitor>
Examples of the rust preventive include acidic sulfite, sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, dicyclohexylammonium nitrite and the like.

<Antioxidant>
Examples of the antioxidant include a phenol-based antioxidant (including a hindered phenol-based antioxidant), an amine-based antioxidant, a sulfur-based antioxidant, a phosphorus-based antioxidant, and the like.

<UV absorber>
Examples of the ultraviolet absorber include benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, salicylate-based ultraviolet absorbers, cyanoacrylate-based ultraviolet absorbers, nickel complex salt-based ultraviolet absorbers, and the like.

<Manufacturing of ink>
In the ink of the present invention, a coloring material, a polymer compound, a compound represented by the above general formula (1), an organic solvent, water, and other components to be added as necessary are dispersed or dissolved in an aqueous medium. Further, if necessary, it is manufactured by stirring and mixing. This stirring and mixing can be performed by, for example, a sand mill, a homogenizer, a ball mill, a paint shaker, an ultrasonic disperser, etc., and the stirring and mixing is performed by a stirrer using ordinary stirring blades, a magnetic stirrer, a high-speed disperser, or the like. be able to.

The particle size of the solid content in the ink is not particularly limited and can be appropriately selected depending on the intended purpose. From the viewpoint of improving image quality such as ejection stability and image density, the maximum frequency of the particle size of the solid content in the ink is preferably 20 nm or more and 1000 nm or less in terms of the maximum number, and more preferably 20 nm or more and 150 nm or less. The solid content includes resin particles, pigment particles, and the like. The particle size can be measured using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrac Bell Co., Ltd.).

<Ink physical characteristics>
The physical characteristics of the ink of the present invention are not particularly limited and can be appropriately selected depending on the intended purpose.
However, when the static surface tension of the ink is 20 mN / m or more and the dynamic surface tension at a bubble lifetime of 15 msec by the maximum bubble pressure method is 34 mN / m or less, sufficient wettability with respect to the recording medium is ensured. Despite the fact that the ink jet head can be used, the nozzle plate optool of the inkjet head is less likely to get wet with the water-repellent film, the ejection stability can be ensured, and the ink is extremely stable, which is preferable.
The viscosity of the ink at 25 ° C. is preferably 5 to 25 mPa · s, more preferably 6 to 20 mPa · s. If it is 5 mPa · s or more, the effect of improving the print density and the character quality can be obtained. Further, if it 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 uses a piezoelectric element as an inkjet head as a pressure generating means for pressurizing the ink in the ink flow path to deform a vibrating plate forming the wall surface of the ink flow path to change the volume inside the ink flow path. A so-called piezo type that ejects ink droplets (see JP-A-2-51734), or a so-called thermal type that heats ink in the ink flow path using a heat generating resistor to generate bubbles (see JP-A-2-51734). (Refer to JP-A-61-59911), the vibrating plate forming the wall surface of the ink flow path and the electrode are arranged facing each other, and the vibrating plate is deformed by the electrostatic force generated between the vibrating plate and the electrode. It can be satisfactorily used for a printer equipped with any ink jet head, such as an electrostatic type that changes the volume in the ink flow path to eject ink droplets (see JP-A-6-71882).
Further, the ink of the present invention may be stored and used in an ink storage container such as an ink cartridge.

<Ink container>
The ink container of the present invention is an ink container provided with an ink accommodating portion for accommodating ink, and the ink contained in the ink accommodating portion is the ink of the present invention. The ink is housed in a container and further has other members appropriately selected as needed.
The container is not particularly limited, and its shape, structure, size, material, etc. can be appropriately selected according to the purpose. For example, an ink container made of an aluminum laminate film, a resin film, or the like can be used. At least those having, for example, a main tank having an ink accommodating portion, an ink cartridge, and the like are suitable.

<Recording medium>
The recording medium capable of recording using the ink of the present invention is not particularly limited and may be appropriately selected depending on the intended purpose. For example, plain paper, glossy paper, special paper, cloth, film, OHP. Examples include sheets and general-purpose printing paper. However, the ink of the present invention is very excellent in that it can record as good as other papers on commercial printing papers.
The commercial printing paper referred to here is a printing paper having a coating layer on at least one surface of the support, and for example, a printing paper using a filler such as calcium carbonate or kaolin as the coating layer material. Can be mentioned. Further, in the printing coated paper, which is an example of commercial printing paper, the coating layer is made of a white pigment such as clay (kaolin) or calcium carbonate, and an adhesive (binder) such as starch.

A recorded material having an image formed by using the ink of the present invention has high image quality, no bleeding, excellent stability over time, and is suitably used for various purposes as a material on which various prints or images are recorded. Can be done.
Among the recording media, the liquid absorption characteristics are within a certain range because it is possible to record images with excellent image quality (image density, saturation, beading, color bleeding), high glossiness, and excellent smear fixing property. The recording medium inside is suitable. Specific examples thereof include commercial printing paper having a coating layer on at least one surface of the support, and pure water on the surface having the coating layer at a contact time of 100 ms measured by a dynamic scanning liquid absorbent meter. A printing paper having a transfer amount of 2 to 35 mL / m ² to the printing paper and a transfer amount of pure water to the printing paper at a contact time of 400 ms is preferably 3 to 40 mL / m ² . If the amount of pure water transferred is too small, beading (a phenomenon in which adjacent dots are attracted to each other to give a lumpy feeling to the image) and color bleeding (bleeding between colors) are likely to occur. If the amount of pure water transferred is too large, the ink dot diameter after recording may be smaller than the desired diameter and the solid image may not be filled.

The transfer amount of pure water can be measured using a dynamic scanning liquid absorption meter (K350 series D type, manufactured by Kyowa Seiko Co., Ltd.). The transfer amount at the contact time of 100 ms can be obtained by interpolation from the measured value of the transfer amount at the neighboring contact time of each contact time.
Commercially available products of printing paper whose liquid absorption characteristics are within the certain range include, for example, POD gloss coat, OK top coat +, OK Kanto +, SA Kanto + (manufactured by Oji Paper Mills), Super MI Dal, Aurora Coat, and the like. Space DX (manufactured by Nippon Paper Industries), α mat, Mucoat (manufactured by Hokuetsu Paper Co., Ltd.), Raicho Art, Raicho Super Art (manufactured by Chuetsu Pulp & Paper Co., Ltd.), Pearl Coat N (manufactured by Mitsubishi Paper Mills Limited), etc.

<Recording device, recording method>
The ink of the present invention can be suitably used for various recording devices by an inkjet recording method, for example, a printer, a facsimile device, a copying device, a printer / fax / copier multifunction device, a three-dimensional modeling device, and the like.
In the present invention, the recording device and the recording method are devices capable of ejecting ink, various processing liquids, and the like to a recording medium, and a method for recording using the device. The recording medium means a medium to which ink and various treatment liquids can adhere even temporarily.
This recording device can include not only a head portion for ejecting ink, but also means related to feeding, transporting, and discharging paper of a recording medium, a pretreatment device, a device called a posttreatment device, and the like. ..
The recording device and the recording method may have a heating means used in the heating step and a drying means used in the drying step. The heating means and the drying means include, for example, means for heating and drying the printed surface and the back surface of the recording medium. The heating means and the drying means are not particularly limited, but for example, a hot air heater and an infrared heater can be used. Heating and drying can be performed before printing, during printing, after printing, and the like.
Further, the recording device and the recording method are not limited to those in which significant images such as characters and figures are visualized by ink. For example, those that form patterns such as geometric patterns and those that form three-dimensional images are also included.
Further, the recording device includes both a serial type device that moves the discharge head and a line type device that does not move the discharge head, unless otherwise specified.
Further, as this recording device, it is possible to use not only a desktop type but also a wide recording device capable of printing on an A0 size recording medium, or, for example, continuous paper wound in a roll shape as a recording medium. A continuous book printer is also included.
An example of the recording device will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective explanatory view of the device. FIG. 2 is a perspective explanatory view of the main tank. The image forming apparatus 400 as an example of the recording apparatus is a serial type image forming apparatus. A mechanism portion 420 is provided in the exterior 401 of the image forming apparatus 400. Each ink storage portion 411 of the main tank 410 (410k, 410c, 410m, 410y) for each color of black (K), cyan (C), magenta (M), and yellow (Y) is, for example, a package of an aluminum laminated film or the like. It is formed of members. The ink container 411 is housed in, for example, a plastic container case 414. As a result, the main tank 410 is used as an ink cartridge for each color.
On the other hand, a cartridge holder 404 is provided behind the opening when the cover 401c of the main body of the apparatus is opened. A main tank 410 is detachably attached to the cartridge holder 404. As a result, each ink ejection port 413 of the main tank 410 and the ejection head 434 for each color communicate with each other via the supply tube 436 for each color, and ink can be ejected from the ejection head 434 to the recording medium.

This recording device can include not only a portion for ejecting ink but also a device called a pretreatment device, a posttreatment device, and the like.
As one aspect of the pretreatment apparatus and the posttreatment apparatus, it has a pretreatment liquid and a posttreatment liquid as in the case of inks such as black (K), cyan (C), magenta (M), and yellow (Y). There is an embodiment in which a liquid accommodating portion and a liquid discharge head are added, and a pretreatment liquid or a posttreatment liquid is discharged by an inkjet recording method.
As another aspect of the pretreatment device and the posttreatment device, there is a mode in which a pretreatment device and a posttreatment device by, for example, a blade coating method, a roll coating method, and a spray coating method are provided other than the inkjet recording method.

<Pretreatment liquid>
The pretreatment liquid contains a flocculant, an organic solvent, and water, and may contain a surfactant, an antifoaming agent, a pH adjuster, an antiseptic / antifungal agent, an anticorrosive agent, and the like, if necessary.
As the organic solvent, surfactant, defoaming agent, pH adjuster, antiseptic and antifungal agent, and rust preventive, the same materials as those used for ink can be used, and other materials used for known treatment liquids can be used. ..
The type of flocculant is not particularly limited, and examples thereof include water-soluble cationic polymers, acids, and polyvalent metal salts.

<Post-treatment liquid>
The post-treatment liquid is not particularly limited as long as it is possible to form a transparent layer. The post-treatment liquid is obtained by selecting and mixing organic solvents, water, resins, surfactants, defoamers, pH adjusters, antiseptic and antifungal agents, rust preventives and the like, if necessary. Further, the post-treatment liquid may be applied to the entire recording area formed on the recording medium, or may be applied only to the area where the ink image is formed.

<Recorded material>
The ink recording material of the present invention comprises an image formed by using the ink of the present invention on a recording medium.
It can be recorded by an inkjet recording device and an inkjet recording method to obtain a recorded material.

The use of the ink of the present invention is not particularly limited and may be appropriately selected depending on the intended purpose, and can be applied to, for example, printed matter, paints, coating materials, base materials and the like. Further, it can be used not only as an ink to form a two-dimensional character or an image, but also as a material for three-dimensional modeling for forming a three-dimensional three-dimensional image (three-dimensional model).
As the three-dimensional modeling apparatus for modeling the three-dimensional object, a known one can be used, and is not particularly limited, but for example, an apparatus provided with ink accommodating means, supply means, ejection means, drying means and the like is used. be able to. The three-dimensional model includes a three-dimensional model obtained by overcoating with ink. Further, a molded product obtained by processing a structure in which ink is applied on a base material such as a recording medium is also included. The molded product is, for example, a recorded material or structure formed in a sheet shape or a film shape, which has been subjected to molding processing such as heat stretching or punching. It is suitably used for molding after decorating the surface of electronic devices, meters of cameras, panels of operation parts, and the like.

Further, in the terms of the present invention, image formation, recording, printing, printing, etc. are all synonymous.

Recording media, media, and printed matter are all synonymous.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In addition, "part" and "%" in an example are "part by mass" and "% by mass" unless otherwise specified.

<Polymer compound P-1>
10.83 g (104 mmol) of styrene is dissolved in 4.33 g (60 mmol) of acrylic acid, 130 g of ion-exchanged water, 4.00 g of Aqualon KH-10 (anionic radical reactive surfactant manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.). Activator) and 1.30 g of ammonium persulfate were added to form a preemulsion with a homomixer. Then, 2.00 g of Aqualon KH-10 was added to 100 g of ion-exchanged water, heated to 80 ° C. under an argon air stream, 10% of the preemulsion was added, and the initial polymerization was carried out for 30 minutes. Then, the remaining preemulsion was polymerized while dropping over 2 hours, and then polymerized at 80 ° C. for 2 hours. After cooling, the mixture was filtered and neutralized with aqueous ammonia to obtain a resin emulsion of the polymer compound P-1 having B / A = 0.40 and a solid content concentration of 40%.

<Polymer compound P-2>
Polymer compound P- with B / A = 0.40 and solid content concentration of 40% using the same materials and methods as polymer compound P-1 except that styrene of polymer compound P-1 was changed to benzyl acrylate. The resin emulsion of 2 was obtained.

<Polymer compound P-3>
Polymer compound P- with B / A = 0.40 and solid content concentration of 40% using the same materials and methods as polymer compound P-1 except that styrene of polymer compound P-1 was changed to benzyl methacrylate. The resin emulsion of 3 was obtained.

<Polymer compound P-4>
Polymer compound P with B / A = 0.40 and solid content concentration of 40% using the same materials and methods as polymer compound P-1 except that the acrylic acid of the polymer compound P-1 was changed to methacrylic acid. A resin emulsion of -4 was obtained.

<Polymer compound P-5>
A polymer having a solid content concentration of 40% using the same materials and methods as the polymer compound P-1 except that B / A = 0.40 of the polymer compound P-1 was changed to B / A = 0.60. A resin emulsion of compound P-5 was obtained.

<Polymer compound P-6>
62.0 parts by mass (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 by mass (262 mmol) of pyridine was added. A solution prepared by dissolving 50.0 parts by mass (262 mmol) of 2-naphthalenecarbonyl chloride (manufactured by Tokyo Kasei Kogyo Co., Ltd.) in 100 mL of methylene chloride was added dropwise to this solution with stirring over 2 hours, and then at room temperature for 6 hours. Stirred. After washing the obtained reaction solution with water, the organic phase was isolated, dried over magnesium sulfate, and the solvent was distilled off. 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 by mass of 2-naphthoic acid-2-hydroxyethyl ester. rice field.
Next, 42.1 parts by mass (155 mmol) of 2-naphthoic acid-2-hydroxyethyl ester was dissolved in 80 mL of dry methyl ethyl ketone and heated to 60 ° C. A solution prepared by dissolving 24.0 parts by mass (155 mmol) of 2-methacryloyloxyethyl isocyanate (Carens MOI, manufactured by Showa Denko KK) in 20 mL of dry methyl ethyl ketone was added dropwise to this solution with stirring over 1 hour, and then 70. The mixture was stirred at ° C. for 12 hours. After cooling to room temperature, the solvent was distilled off. The residue is purified by silica gel column chromatography using a mixed solvent of methylene chloride / methanol (volume ratio: 99/1) as an eluent, and has a structure represented by the following [Structural formula (2) -1]. 57.0 parts by volume of the monomer was obtained.

Next, 7.12 parts by mass (16.7 mmol) of the monomer having the structure represented by the above [Structural formula (2) -1] and 1.92 parts by mass (26.7 mmol) of acrylic acid (manufactured by Sigma-Aldrich). Was dissolved in 40 mL of methyl ethyl ketone to prepare a monomer solution. After heating 10% by mass of the monomer solution to 75 ° C. under an argon stream, add 2,2'-azoiso (butyronitrile) (manufactured by Tokyo Kasei Kogyo Co., Ltd.) 0.273 parts by mass (1.67 mmol) to the remaining monomer solution. The solution was added dropwise over 1.5 hours, and the mixture was stirred at 60 ° C. for 15 hours. The mixture was cooled to room temperature, and the obtained reaction solution was dropped onto hexane. The precipitated polymer compound was filtered off and dried under reduced pressure to obtain 8.13 parts by mass of the polymer compound. B / A is obtained by dissolving the obtained polymer compound in a dimethylethanolamine aqueous solution so as to be 100% acid-neutralized, and adjusting the concentration with ion-exchanged water so that the concentration of the polymer compound becomes 10% by mass. = 0.27 high molecular weight compound P-6 was obtained.

<Polymer compound P-7>
A polymer having B / A = 0.20 using the same materials and methods as the polymer compound P-6 except that 1.92 parts by mass of acrylic acid in the polymer compound P-6 was changed to 1.44 parts by mass. Compound P-7 was obtained.

<Polymer compound P-8>
Polymer compound P-8 was obtained using the same materials and methods as polymer compound P-1 except that B / A = 0.40 of polymer compound P-1 was changed to B / A = 0.15. rice field.

<Polymer compound P-9>
Polymer compound P-9 was obtained using the same materials and methods as polymer compound P-1 except that B / A = 0.40 of polymer compound P-1 was changed to B / A = 0.65. rice field.

<Dispersion 1>
Ion-exchanged water was added to the surface-treated (self-dispersed) pigment dispersion IJX-2450C (Pigment Blue15: 3, manufactured by Cabot) to adjust the pigment concentration to 15%.
<Dispersion 2>
Ion-exchanged water was added to the surface-treated (self-dispersed) pigment dispersion IJX-2470Y (Pigment Yellow155, manufactured by Cabot) to adjust the pigment concentration to 15%.
<Dispersion 3>
Ion-exchanged water was added to the surface-treated (self-dispersed) pigment dispersion Cab-O-Jet 406K (carbon black, manufactured by Cabot) to adjust the pigment concentration to 15%.

<Dispersion 4>
・ CINQUASIA MAGENTA D4500J ・ ・ ・ 15.0 parts by mass (Pigment Violet 19 / Pigment Red 202 mixed crystal, manufactured by BASF)
・ Polymer compound P-6 (10% aqueous solution) ・ ・ ・ 40.0 parts by mass ・ Ion-exchanged water ・ ・ ・ 45.0 parts by mass Add polymer compound P-6 to ion-exchanged water and add the pigment CINQUASIA MAGENTA D4500J. After mixing, stirring and sufficiently moistening, a dynomill KDL A type (manufactured by WAB) was filled with φ0.5 mm zirconia beads as a kneading device, and kneaded at 2000 rpm for 60 minutes. The mill base was taken out and filtered through a 1 μm filter to obtain a pigment dispersion 4.

<Dispersion 5>
40.0 parts by mass of the polymer compound P-6 used for the dispersion 4 was changed to 80.0 parts by mass of the polymer compound P-7, and 45.0 parts by mass of ion-exchanged water was changed to 5.0 parts by mass. The dispersion 5 was obtained by using the same materials and methods as those of the dispersion 4 except that the dispersion was changed.
<Dispersion 6>
Dispersion 6 was obtained using the same materials and methods as dispersion 5 except that the pigment CINQUASIA MAGENTA D4500J used for dispersion 5 was changed to cyanine blue A-220 (PB15: 3, manufactured by Dainichiseika Co., Ltd.). rice field.

(Example 1)
<Ink 1>
・ Dispersion 1 ・ ・ ・ 36.0 parts by mass ・ 3-Ethyl-3-hydroxymethyloxetane ・ ・ ・ 5.0 parts by mass ・ 3-Methyl-1,3-butanediol ・ ・ ・ 15.0 parts by mass ・1,2-Propanediol ・ ・ ・ 10.0 parts by mass ・ 2-Ethyl-1,3-hexanediol ・ ・ ・ 2.0 parts by mass ・ Structural formula (1) -1 (R: C9 alkyl, R ₁ : Methyl, a compound represented by n = 3)
・ ・ ・ 0.2 parts by mass ・ Compound represented by structural formula (3) -1 (m = 3, k = 12) ・ ・ ・ 0.3 parts by mass ・ Polymer compound P-1 (solid content concentration 40) %) ・ ・ ・ 12.5 parts by mass ・ pH adjuster (2-amino-2-ethyl-1,3-propanediol)
・ ・ ・ 0.5 parts by mass ・ Antiseptic and antifungal agent (Proxel LV, manufactured by Lonza Japan) ・ ・ ・ 0.1 parts by mass ・ Ion-exchanged water ・ ・ ・ 18.4 parts by mass After dissolving in ion-exchanged water to prepare a vehicle, it was mixed with the dispersion 1 and filtered through a filter having an average pore size of 1 μm to obtain ink 1.

(Example 2)
Dispersion 1 in ink 1 of Example 1 is changed to dispersion 2, 0.2 parts by mass of structural formula (1) -1 is changed to 0.5 parts by mass, and 0. Ink 2 was obtained using the same formulation and method as in Example 1 except that 3 parts by mass was changed to 0.0 parts by mass.
(Example 3)
The dispersion 1 in the ink 1 of Example 1 was changed to the dispersion 3, and 0.2 parts by mass of the structural formula (1) -1 was changed to 0.1 parts by mass, and 0. Ink 3 was obtained using the same formulation and method as in Example 1 except that 3 parts by mass was changed to 0.4 parts by mass.
(Example 4)
Ink 4 was obtained using the same formulation and method as in Example 1 except that the dispersion 1 in the ink 1 of Example 1 was changed to the dispersion 4.

(Example 5)
In the ink 4 of Example 4, 5.0 parts by mass of 3-ethyl-3-hydroxymethyloxetane was changed to 0.5 parts by mass, and 10.0 parts by mass of 1,2-propanediol was changed to 14.5 parts by mass. Ink 5 was obtained using the same formulation and method as in Example 4.
(Example 6)
In the ink 4 of Example 4, 5.0 parts by mass of 3-ethyl-3-hydroxymethyloxetane was changed to 3.0 parts by mass, and 10.0 parts by mass of 1,2-propanediol was changed to 12.0 parts by mass. Ink 6 was obtained using the same formulation and method as in Example 4.

(Example 7)
In the ink 4 of Example 4, 5.0 parts by mass of 3-ethyl-3-hydroxymethyloxetane was changed to 7.0 parts by mass, and 10.0 parts by mass of 1,2-propanediol was changed to 8.0 parts by mass. Ink 7 was obtained using the same formulation and method as in Example 4.
(Example 8)
In the ink 4 of Example 4, 5.0 parts by mass of 3-ethyl-3-hydroxymethyloxetane was changed to 10.0 parts by mass, and 10.0 parts by mass of 1,2-propanediol was changed to 5.0 parts by mass. Ink 8 was obtained using the same formulation and method as in Example 4.

(Example 9)
Ink 9 was obtained using the same formulation and method as in Example 4 except that 3-ethyl-3-hydroxymethyloxetane was changed to isopropylideneglycerol in Ink 4 of Example 4.
(Example 10)
Ink 10 was obtained using the same formulation and method as in Example 4 except that 3-ethyl-3-hydroxymethyloxetane was changed to N, N-dimethyl-β-butoxypropionamide in Ink 4 of Example 4. rice field.

(Example 11)
Ink 11 was obtained using the same formulation and method as in Example 4 except that 3-ethyl-3-hydroxymethyloxetane was changed to tripropylene glycol monomethyl ether in Ink 4 of Example 4.
(Example 12)
Ink 12 was obtained using the same formulation and method as in Example 4 except that 3-ethyl-3-hydroxymethyloxetane was changed to methyltriglycol in Ink 4 of Example 4.

(Example 13)
Ink 13 was obtained using the same formulation and method as in Example 4 except that the polymer compound P-1 was changed to the polymer compound P-2 in the ink 4 of Example 4.
(Example 14)
Ink 14 was obtained using the same formulation and method as in Example 4 except that the polymer compound P-1 was changed to the polymer compound P-3 in the ink 4 of Example 4.

(Example 15)
Ink 15 was obtained using the same formulation and method as in Example 4 except that the polymer compound P-1 was changed to the polymer compound P-4 in the ink 4 of Example 4.
(Example 16)
Ink 16 was obtained using the same formulation and method as in Example 4 except that the polymer compound P-1 was changed to the polymer compound P-5 in the ink 4 of Example 4.

(Example 17)
In the ink 4 of Example 4, the compound represented by the structural formula (1) -1 is replaced with the compound represented by the structural formula (1) -2 (R: C13 alkyl, R ₁ : methyl, n = 3). Ink 17 was obtained using the same formulation and method as in Example 4 except for the modification.
(Example 18)
In the ink 4 of Example 4, the compound represented by the structural formula (1) -1 is replaced with the compound represented by the structural formula (1) -3 (R: C9 alkyl, R ₁ : hydrogen, n = 3). Ink 18 was obtained using the same formulation and method as in Example 4 except for the modification.
(Example 19)
In the ink 4 of Example 4, the compound represented by the structural formula (1) -1 is replaced with the compound represented by the structural formula (1) -4 (R: C9 alkyl, R ₁ : methyl, n = 12). Ink 19 was obtained using the same formulation and method as in Example 4 except for the modification.

(Example 20)
In the ink 4 of Example 4, the dispersion 1 was changed to the dispersion 5, 12.5 parts by mass of the polymer compound P-1 was 0.0 parts by mass, and 18.4 parts by mass of the ion-exchanged water was 30. Ink 20 was obtained using the same formulation and method as in Example 4 except that the amount was changed to 9 parts by mass.

(Example 21)
Ink 21 was obtained using the same formulation and method as in Example 20 except that the dispersion 5 was changed to the dispersion 6 in the ink 20 of Example 20.

(Example 22)
Examples of the ink 21 of Example 21 except that the compound represented by the structural formula (3) -1 is changed to the compound represented by the structural formula (3) -2 (m = 0, k = 5). Ink 22 was obtained using the same formulation and method as in 21.

(Example 23)
In the ink 21 of Example 21, the same as that of Example 21 except that the compound represented by the structural formula (3) -1 was changed to Emulgen LS-106 (polyoxyethylene polyoxypropylene alkyl ether, manufactured by Kao Corporation). Ink 23 was obtained using the formulation and method.

(Example 24)
In the ink 21 of Example 21, 1.4 parts by mass of polyethylene wax HYTEC E-6500 (solid content 35%, manufactured by Toho Chemical Industry Co., Ltd.) was added, and 30.9 parts by mass of ion-exchanged water was changed to 29.5 parts by mass. Ink 24 was obtained using the same formulation and method as in Example 21.

(Example 25)
In the ink 21 of Example 21, 1.1 parts by mass of polyethylene wax AQUACER531 (solid content 45%, manufactured by BYK) was added, and 30.9 parts by mass of ion-exchanged water was changed to 29.8 parts by mass. Ink 25 was obtained using the same formulation and method as in 21.

(Comparative Example 1)
In Ink 4 of Example 4, 5.0 parts by mass of 3-ethyl-3-hydroxymethyloxetane was changed to 5.0 parts by mass of N-methyl-2-pyrrolidone (SP value 11.2). Ink 26 was obtained using the same formulation and method as in.

(Comparative Example 2)
In the ink 11 of Example 11, 5.0 parts by mass of tripropylene glycol monomethyl ether was changed to 0.0 parts by mass, and 10.0 parts by mass of 1,2-propanediol was changed to 15.0 parts by mass. Ink 27 was obtained using the same formulation and method as in 11.

(Comparative Example 3)
In the ink 3 of Example 3, 5.0 parts by mass of 3-ethyl-3-hydroxymethyloxetane was changed to 11.0 parts by mass, and 10.0 parts by mass of 1,2-propanediol was changed to 4.0 parts by mass. Ink 28 was obtained using the same formulation and method as in Example 3 except for the above.

(Comparative Example 4)
In ink 1 of Example 1, the ink 29 was prepared using the same formulation and method as in Example 1 except that the polymer compound P-1 was changed to the polymer compound P-8 (B / A = 0.15). Obtained.
(Comparative Example 5)
In ink 1 of Example 1, the ink 30 was prepared using the same formulation and method as in Example 1 except that the polymer compound P-1 was changed to the polymer compound P-9 (B / A = 0.65). Obtained.

(Comparative Example 6)
In the ink 20 of Example 20, the compound represented by the structural formula (1) -1 is a compound having R: C9 alkyl, _R1 : methyl, n = 15 in the general formula (1) (general formula (1). Ink 31 was obtained by using the same formulation and method as in Example 20 except that the compound was changed to).

(Comparative Example 7)
Same as Example 4 except that the compound represented by the structural formula (1) -1 was not added to the ink 4 of Example 4 and the ion-exchanged water was changed from 18.4 parts by mass to 18.6 parts by mass. Ink 32 was obtained using the formulation and method of.

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７に示すが、判定Ａまたは判定Ｂが許容範囲である。
［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 <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 with respect to the viscosity before storage was calculated from the following formula and evaluated according to the following criteria.

A viscometer (RE80L, manufactured by Toki Sangyo Co., Ltd.) was used to measure the viscosity, and the viscosity at 25 ° C. was measured at 50 rpm or 100 rpm. The evaluation results are shown in Table 7, and determination A or determination B is within the permissible range.
[Evaluation criteria]
A: Viscosity change rate within ± 5% B: Viscosity change rate exceeds ± 5% and within ± 10% C: Viscosity change rate exceeds ± 10% and within ± 30% D: Viscosity change Rate exceeds ± 30%

<Ink ejection device>
The inks produced in Examples and Comparative Examples were set in a commercially available inkjet printer (IPSiO GX-e5500 manufactured by Ricoh), and an operation of printing 1000 print charts having a print area of 5% was performed. After resting for 24 hours from the end of printing, the following <discharge stability>, <beading>, <dryness>, and <scratch resistance> were evaluated. The evaluation criteria are shown below.

<Discharge stability>
Using the ink ejection device, droplets were discarded from all nozzles for 1 hour.
One hour later, a nozzle check pattern was printed on glossy inkjet paper (Color Photo Finishing Value, manufactured by FUJIFILM Corporation) to check the number of ejection nozzles in which ink was ejected for the total number of nozzles 384. It was evaluated according to the following criteria. The evaluation results are shown in Table 7, and determination A or determination B is within the permissible range.
[Evaluation criteria]
A: The number of discharge nozzles is 384 (all nozzles discharge)
B: The number of discharge nozzles is 368 or more (level that does not cause any problem in actual use)
C: Number of discharge nozzles is 192 or more and less than 368 D: Number of discharge nozzles is less than 192

<Beading>
A solid image of 5 cm x 5 cm is formed on a recording medium (OK top coat + rice basis weight 104.7 g / m ² (manufactured by Oji Paper Co., Ltd.)) with a pixel density of 1200 dpi x 1200 dpi so that the internal temperature becomes 100 ° C. The printed part was dried for 30 seconds in the set constant temperature bath. The beading of this solid image was visually confirmed and evaluated according to the following criteria. The evaluation results are shown in Table 7, and determination A or determination B is within the permissible range.
〔Evaluation criteria〕
A: None (not visible from a distance of 15 cm)
B: Very few
(Visible from a distance of 15 cm, but not visible from a distance of 50 cm)
C: Slightly present
(Visible from a distance of 50 cm, but not visible from a distance of 1 m)
D: Violent (visible from a distance of 1 m)

<Dryness>
Unprinted paper (4 cm x 4 cm) is layered on a 5 cm x 5 cm solid image formed by the same method as the <Beading> evaluation, and the length is 2 cm x width 2 cm x thickness 0.2 cm. Place the rubber sheet in the center of the paper, place a weight on the rubber sheet so that the pressure applied to the paper from the rubber sheet is 0.5 kgf / cm ² , and place it in an environment of 23 ° C and 50% RH. I left it for a while. After being left to stand, the stacked papers were peeled off, the transfer condition of the pigment to the unprinted paper was visually observed, and the transferability was evaluated according to the following evaluation criteria. The evaluation results are shown in Table 7, and determination A or determination B is within the permissible range.
〔Evaluation criteria〕
A: There is almost no transfer of pigments to paper and there is no sticking between papers. B: There is almost no transfer of pigments to paper, but there is sticking between papers. C: Slightly sticking to paper. Pigment transfer is seen (transfer of less than 10% of the total paper area)
D: Clear pigment transfer to paper is seen (transfer of 10% or more of the total area of the paper)

<Scratch resistance>
Using a clock meter CM-1 (manufactured by Toyo Seiki Co., Ltd.), the printed portion of a 5 cm × 5 cm solid image sample formed by the same method as the above <Beading> evaluation was rubbed with a white cotton cloth 5 times with a load of 900 g. .. The results of evaluation according to the evaluation criteria below are shown in Table 7, and judgment A or judgment B is within the permissible range.
〔Evaluation criteria〕
A: There is almost no image dropout and stains around the image visually B: There is almost no image dropout visually and there is little dirt around the image C: There is little image dropout visually, but there is dirt around the image D: Visually Image dropout and stains around the image are significant

400 Image forming device 401 Image forming device exterior 401c Device body cover 404 Cartridge holder 410 Main tank 410k, 410c, 410m, 410y For each color of black (K), cyan (C), magenta (M), yellow (Y) Main tank 411 Ink storage unit 413 Ink discharge port 414 Storage container case 420 Mechanical unit 434 Discharge head 436 Supply tube

Japanese Unexamined Patent Publication No. 2004-055863

Claims (8)

It contains a coloring material, a polymer compound, a compound represented by the following general formula (1), and a solvent S having an SP value of 9.0 or more and 11.0 or less.
The polymer compound is a polymer compound having a structural unit derived from a vinyl monomer (A) having an aromatic group and a structural unit derived from a monomer (B) which is (meth) acrylic acid or an ester thereof. The ratio B / A (mass ratio) of the structural unit derived from the (meth) acrylic acid or the monomer (B) which is an ester thereof to the structural unit derived from the vinyl monomer (A) having an aromatic group is 0. .20 to 0.60,
An ink in which the content of the solvent S in the ink is 10% by mass or less.
However, in the general formula (1), R represents an alkyl group having 8 to 13 carbon atoms, R ₁ represents a hydrogen atom or a methyl group, and n represents an integer of 2 to 12.

The ink according to claim 1, wherein the solvent S contains at least one selected from 3-ethyl-3-hydroxymethyloxetane, isopropylideneglycerol and N, N-dimethyl-β-butoxypropionamide. The ink according to claim 1 or 2, wherein the content of the solvent S in the ink is 3% by mass or more and 7% by mass or less. The ink according to any one of claims 1 to 3, wherein the structural unit derived from the vinyl monomer (A) having an aromatic group of the polymer compound is the structural unit represented by the following general formula (2).
However, in the formula, R2 is a hydrogen atom or a methyl group, and L is an alkylene group having 2 to 18 carbon atoms.

The ink according to any one of claims 1 to 4, wherein the ink further contains a compound represented by the following general formula (3).
However, in the general formula (3), m = 0 to 7 and k = 2 to 15.

The ink according to any one of claims 1 to 5, wherein the ink further contains polyethylene wax. An ink container for containing the ink according to any one of claims 1 to 6. An inkjet recording apparatus comprising the ink container according to claim 7 and an ejection means for ejecting ink supplied from the ink container.

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