JP2018141134A - Inkjet ink, ink storage container, inkjet recording method, inkjet recording device, and recorded matter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet ink that makes it possible to obtain an image having excellent discharge stability and storage stability, and excellent scratch resistance under normal temperature and normal humidity environment and high temperature and low humidity environment.SOLUTION: An inkjet ink contains an organic solvent, and a polyethylene wax. A degree of penetration of the polyethylene wax measured in accordance with JIS K2235 is 1.2 or less. According to a preferable embodiment, a Martens hardness of the polyethylene wax is 50 N/mmor more.SELECTED DRAWING: None

Description

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

  The inkjet recording method is simple in process and easy to achieve full color, and high resolution images can be obtained even with an apparatus with a simple configuration. Therefore, not only for personal use but also for office use, commercial printing and industrial use. It is spreading into the field of printing.

In the field of commercial printing using the inkjet recording method, coated paper such as coated paper and art paper is used as a recording medium in addition to plain paper. Since the recorded matter recorded on the recording medium is handled as a product such as a postcard or a package, high scratch resistance of the image is required, and the downtime of recording is reduced, and high productivity and ejection stability are achieved. Is required.
However, ink jet inks used in the ink jet recording method and capable of obtaining images having scratch resistance are likely to cause ink sticking in the recording head portion, and are compatible with both scratch resistance and ejection stability. There is a problem that it is difficult.

Therefore, an ink containing a coloring material, alkyl polyols, resin particles, and wax particles has been proposed (see, for example, Patent Document 1).
Further, an ink jet recording system using a water-based ink composition containing a water-insoluble colorant, resin particles, silicone-based surfactant, water, etc., wherein the resin particles contain resin fixing particles and wax particles. A printing method has been proposed (see, for example, Patent Document 2).
Furthermore, it contains a pigment, first wax particles, second wax particles, and a resin emulsion, and the first wax particles include one or more wax particles selected from the group consisting of polyethylene wax particles or polypropylene wax particles. An ink composition in which the second wax particles include polyethylene wax particles has been proposed (see, for example, Patent Document 3).
Furthermore, an ink set for inkjet recording of an ink containing a polyurethane resin and a polyolefin wax has been proposed (see, for example, Patent Document 4).

  An object of the present invention is to provide an ink-jet ink that is excellent in ejection stability and storage stability and can obtain an image having good scratch resistance under a normal temperature and normal humidity environment and a high temperature and low humidity environment.

  The inkjet ink of the present invention as a means for solving the above problems is an inkjet ink containing an organic solvent and polyethylene wax, and the penetration of the polyethylene wax measured in accordance with JIS K2235, 1.2 or less.

  According to the present invention, it is possible to provide an ink-jet ink that is excellent in ejection stability and storage stability and can obtain an image having good scratch resistance under a normal temperature and normal humidity environment and a high temperature and low humidity environment.

FIG. 1 is a perspective explanatory view showing an example of a serial type image forming apparatus. FIG. 2 is a perspective explanatory view showing an example of a main tank of the apparatus of FIG. FIG. 3 is a graph showing the results of differential scanning calorimetry measurement of the polyethylene wax 1 emulsion used in Example 1. FIG. 4 is a graph showing the results of differential scanning calorimetry of the polyethylene wax 2 emulsion used in Example 7.

(Inkjet ink)
The ink-jet ink of the present invention (hereinafter also referred to as “ink”) is an ink-jet ink containing an organic solvent and polyethylene wax, and the penetration of the polyethylene wax measured according to JIS K2235. Is 1.2 or less, and further contains resin particles, water, a coloring material, and other components as necessary.
The inkjet ink of the present invention is suitably used as an ink for coloring a recording medium, but includes a clear ink and an overcoat liquid that do not contain a color material.

  An object of the present invention is to provide an inkjet ink that is excellent in ejection stability and storage stability, and can obtain an image having good scratch resistance under a normal temperature and normal humidity environment and a high temperature and low humidity environment. Provides ink for inkjet that has excellent ejection stability and storage stability, has high image density, and can provide images with excellent scratch resistance and glossiness under normal temperature and normal humidity and high temperature and low humidity environments. The purpose is to do.

  According to the present invention, it is possible to provide an ink jet ink that is excellent in ejection stability and storage stability, and can obtain an image having good scratch resistance under a normal temperature and normal humidity environment and a high temperature and low humidity environment. Provides ink for inkjet that has excellent ejection stability and storage stability, has high image density, and can provide images with excellent scratch resistance and glossiness under normal temperature and normal humidity and high temperature and low humidity environments. can do.

As a result of intensive studies, the present inventors have found the following.
It is well known that ink jet ink contains polyethylene wax to improve the scratch resistance. However, unless the polyethylene wax content exceeds a certain level, the effect of scratch resistance cannot be obtained. When the content is obtained, there are problems such as a decrease in image quality due to a decrease in density and gloss of the image obtained, a decrease in ejection stability, and a decrease in storage stability of ink. However, in the polyethylene wax, by using a polyethylene wax with high hardness, the effect of scratch resistance can be sufficiently obtained even with a small content, and there is almost no such problem, and the ejection stability, good ink quality, and We found that image quality can be obtained.
The polyethylene wax is generally known to be harder as the density and crystallinity are higher, and the density and crystallinity can be changed by changing the structure. The polyethylene wax has higher density and higher crystallinity and higher hardness as the molecular chain is linear, and when the molecular chain has more branched chains, the density and crystallinity are lowered and the hardness is lowered.
The polyethylene wax used in the conventional ink is lower than the hardness of the polyethylene wax used in the present invention, and the effect obtained in the present invention was not obtained. It was found that the above-mentioned effects can be obtained by setting the above range.

<Polyethylene wax>
The polyethylene wax can reduce the dynamic friction coefficient of the surface of the image (ink film) formed by the ink jet ink of the present invention, and can improve the scratch resistance of the image.

-Penetration of polyethylene wax-
The penetration of the polyethylene wax measured according to JIS K2235 is 1.2 or less, preferably 0.30 or more and 1.2 or less, more preferably 0.30 or more and 1.0 or less. 50 or more and 1.0 or less are more preferable, and 0.50 or more and 0.95 or less are particularly preferable. When the penetration is 1.2 or less, the scratch resistance can be drastically improved with a small addition amount of the polyethylene wax, and the ejection stability, ink storage stability, image density, and glossiness can be improved. Can reduce side effects. The penetration degree represents the length that the needle can be pushed in when a certain force is applied, and the lower the value, the harder the needle penetration.

The penetration measurement method can be measured in accordance with JIS K2235 or ASTM D1321.
There is no restriction | limiting in particular as a penetration meter used for the said penetration measurement method, According to the objective, it can select suitably, For example, an automatic penetration tester (device name: RPM-201, stock | stock) It can measure as follows using a company separation company etc.).
As a measurement sample, 100 g of a dried product obtained by drying a polyethylene wax emulsion at 70 ° C. is put in a pan, melted at a temperature 20 ° C. higher than the melting point, and then solidified by natural cooling to obtain a wax solidified product. At this time, it is confirmed that the surface of the measurement sample is smooth. After solidification, the sample (wax-solidified product) is set on a testing machine so that the surface touching the pan can be stabbed with a needle. The sample (wax-solidified product) can be pushed in for 5 seconds using a needle with a 50 g weight in a 25 ° C. environment, and the penetration can be measured. The needle used for the measurement is conical stainless steel, and the surface roughness of the needle is 0.2 μm or less. In the projection, the tip of the cone is at an angle of 9 °, and the weight of the needle is 2.5 g.

-Martens hardness of polyethylene wax-
Examples of the Martens hardness of the polyethylene wax is preferably 50 N / mm ² or more, 50 N / mm ² or more 100 N / mm ² or less being more preferred. When the Martens hardness is 50 N / mm ² or more, the scratch resistance can be drastically improved with a small addition amount of the wax, and the ejection stability, ink storage stability, image density, and gloss can be improved. Side effects can be reduced. The Martens hardness is defined as a quotient of the applied test force F (N) and the surface area A (mm ² ) of the dent, and indicates that the larger the value, the harder it is.

  As the Martens hardness, a polyethylene wax emulsion is coated on a support such as a slide glass (trade name: white plate glass S111, manufactured by Matsunami Glass Industry Co., Ltd.) so as to have an average thickness of 10 μm or more, and is heated to 60 ° C. Then, after pre-drying for 3 hours, it is dried at 100 ° C. for 6 hours to obtain a wax solidified product. After the obtained wax solidified product was pushed in for 10 seconds with a force of 1.0 mN using a micro hardness meter (device name: HM-2000, manufactured by Fischer Instruments Co., Ltd.) for 5 seconds, It can be measured by pulling out in 10 seconds with a force of 1.0 mN.

As the polyethylene wax, a commercially available product can be used. Examples of the commercially available product include Aqua Petro DP2502C (manufactured by Toyo Adre Co., Ltd., penetration: 0.5, Martens hardness: 73 N / mm ² , melting point: 126 ° C.), Aqua Petro DP2401 (manufactured by Toyo Adre Co., Ltd., penetration: 1.0, Martens hardness: 51 N / mm ² , melting point: 110 ° C.), and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, Aqua Petro DP2502C is preferable. These polyethylene waxes are considered to have high hardness because their molecular chains are linear and have high density and crystallinity. In addition, brand name: Nopcoat PEM-17 (manufactured by San Nopco Co., Ltd.) and brand name: Polylon L787 (manufactured by Chukyo Yushi Co., Ltd.) are outside the range of the penetration of the wax of the present invention.

The endothermic peak of the polyethylene wax is preferably in the range of 100 ° C. or higher and 130 ° C. or lower in differential scanning calorimetry (DSC).
The exothermic peak of the polyethylene wax is preferably in the range of 100 ° C. or higher and 130 ° C. or lower in differential scanning calorimetry (DSC).
The peak area of the exothermic peak of the polyethylene wax is preferably 200 J / g or more and 300 J / g or less in differential scanning calorimetry (DSC).
Since the polyethylene wax used in the inkjet ink of the present invention has high density and crystallinity, the endothermic peak, exothermic peak, and peak area of the exothermic peak are in the above ranges.
Among these, it has an endothermic peak in the range of 119 ° C. to 129 ° C. and an exothermic peak in the range of 107 ° C. to 117 ° C., and the peak area of the exothermic peak is 230 J / g to 270 J / g; It has an endothermic peak in the range of 117 ° C. or lower and an exothermic peak in the range of 100 ° C. or higher and 110 ° C. or lower, and the peak area of the exothermic peak is preferably 205 J / g or higher and 245 J / g or lower, and a range of 119 ° C. or higher and 129 ° C. or lower. It has an endothermic peak and an exothermic peak in the range of 107 ° C. to 117 ° C., and the peak area of the exothermic peak is more preferably 230 J / g or more and 270 J / g or less.

As a measuring method of differential scanning calorimetry (DSC) of the polyethylene wax, it can be measured using a high sensitivity differential scanning calorimeter (device name: Thermo plus EV02, manufactured by Rigaku Corporation).
When measuring the polyethylene wax, 3 mL of the polyethylene wax emulsion is dropped on a petri dish having a diameter of 3 cm, dried for 5 hours using a thermostatic bath at 70 ° C., 10 mg of the wax solidified product (sample) is taken, and the sample pan is taken Put in. Also a reference those containing the powder of _Al 2 _{O 3} to 10mg sample pan. A sample and a reference are set in a measurement cell, the temperature is raised from 25 ° C to 100 ° C at 10 ° C / min, from 100 ° C to 170 ° C at 5 ° C / min, from 170 ° C to 100 ° C at 5 ° C / min, It can be measured by lowering the temperature from 100 ° C. to 25 ° C. at 10 ° C./min.

As the peak area of the exothermic peak, using the analysis software of a high-sensitivity differential scanning calorimeter (device name: Thermo plus EV02, manufactured by Rigaku Corporation), the peak position of the exotherm and two points serving as a base are selected, Thus, the area can be calculated. The exothermic peak has a maximum value in a range of 100 ° C. or higher and 130 ° C. or lower, and two points serving as a base include a minimum temperature between + 20 ° C. and −20 ° C. of the peak temperature of the maximum value. The minimum temperature between can be taken.
Similarly, when measuring the solid matter of ink-jet ink, 3 mL of ink-jet ink is dropped on a petri dish having a diameter of 3 cm and dried in a thermostatic bath at 70 ° C. for 5 hours to prepare a dried ink-jet ink. It can be measured in the same manner as when measuring polyethylene wax.

As melting | fusing point of the said polyethylene wax, 70 to 170 degreeC is preferable, and 110 to 170 degreeC is more preferable.
In addition, a system such as a high-speed continuous entry machine generally includes a step of drying an image, but it is preferable that the melting point of polyethylene wax is 10 ° C. or more higher than the drying temperature at that time.

The volume average particle size of the polyethylene wax is preferably 500 nm or less, and more preferably 300 nm or less. When the volume average particle size is 500 nm or less, good ejection stability can be obtained without being caught by a nozzle or a filter in the head.
The volume average particle diameter can be measured using, for example, a particle size analyzer (Microtrac Model UPA9340, manufactured by Nikkiso Co., Ltd.).

  The content of the polyethylene wax is preferably 0.05% by mass or more and 2% by mass or less, more preferably 0.05% by mass or more and 0.5% by mass or less, and more preferably 0.05% by mass with respect to the total amount of the inkjet ink. % To 0.45% by mass is more preferable, and 0.15% to 0.45% by mass is particularly preferable. When the content is 0.05% by mass or more and 2% by mass or less, there is a sufficient effect in reducing the dynamic friction coefficient of the surface of the obtained image (ink film), and the storage stability and ejection stability of the ink. It is hard to adversely affect. Further, when the content is 0.45% by mass or less, the storage stability and ejection stability of the ink are particularly good, and it is more suitable for use in an ink jet system.

<Organic solvent>
The organic solvent used in the present invention is not particularly limited, and a water-soluble organic solvent can be used. Examples thereof include ethers such as polyhydric alcohols, polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines and sulfur-containing compounds.
Specific examples of the water-soluble organic solvent include, for example, 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-he Polyhydric alcohols such as sundiol, ethyl-1,2,4-butanetriol, 1,2,3-butanetriol, 2,2,4-trimethyl-1,3-pentanediol, petriol, ethylene glycol mono Polyhydric alcohol alkyl ethers such as ethyl 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, ethylene glycol monophenyl ether, ethylene glycol mono Polyhydric alcohol aryl ethers such as benzyl ether, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl- -Nitrogen-containing heterocyclic compounds such as pyrrolidone, 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, γ-butyrolactone, formamide, N-methylformamide, N, N-dimethylformamide, 3-methoxy-N, Amides such as N-dimethylpropionamide and 3-butoxy-N, N-dimethylpropionamide, amines such as monoethanolamine, diethanolamine and triethylamine, sulfur-containing compounds such as dimethylsulfoxide, sulfolane and thiodiethanol, propylene carbonate, Examples thereof include ethylene carbonate.
In addition to functioning as a wetting agent, it is preferable to use an organic solvent having a boiling point of 250 ° C. or lower, and more preferably 1.2-propanediol, because good drying properties can be obtained.

The 1.2-propanediol is a colorless and odorless slightly viscous dihydric alcohol that is completely dissolved in water, and thus has an effect as a moisturizing agent in the ink state and is formed using ink. By coexisting with the polyethylene wax in the film state, an image excellent in scratch resistance can be obtained particularly in a dry environment.
The polyethylene wax can be improved in scratch resistance under moisturizing conditions, and has a property of decreasing under dry conditions, but it can be moisturized by coexisting with 1,2-propanediol, and thus dried. It becomes possible to prevent a decrease in scratch resistance even under conditions.
As a condition for obtaining a scratch resistance effect due to the coexistence with 1,2-propanediol, a humidity of 40% RH or less is preferable, and a humidity of 10% RH to 20% RH is more preferable.

A polyol compound having 8 or more carbon atoms and a glycol ether compound are also preferably used. Specific examples of the polyol compound having 8 or more carbon atoms include 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, and the like.
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. Examples of ethers include polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.

  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.

Examples of the organic solvent, the total Hansen solubility parameters (hereinafter sometimes also referred to as "totHSP value") is preferably contains a solvent having ^{20 MPa 1/2} or more ^{23 MPa 1/2} or less, 20.2 MPa ^1/2 It is more preferable to include a solvent that is 22.6 MPa ^1/2 or less. The total Hansen solubility parameter, to include solvent is ^{20 MPa 1/2} or more ^{23 MPa 1/2} or less in the ink can be held long-uniform dispersed state, thereby improving the storage stability of the ink. As the organic solvent in the ink, wherein preferably contains a solvent of one or more total Hansen solubility parameters is at ^{20 MPa 1/2} or more ^{23 MPa 1/2} or less, it may be two or more, the total Hansen solubility parameters There may consist of only the solvent is ^{20 MPa 1/2} or more ^{23 MPa 1/2} or less.

The totHSP value is an index representing the solubility of a substance. The totHSP value is different from the Hilde brand SP value used in Solvent Handbook (Kodansha Scientific Co., Ltd., published in 1976) and has a multi-dimensional solubility (typically 3D). ) Vector. This vector can typically be expressed by a dispersion term (δD), a polarity term (δP), and a hydrogen bond term (δH), where the dispersion term (δD) is a van der Waals force, a polarity term (δP) Represents the dipole moment, and the hydrogen bond term (δH) reflects the action of water, alcohol, and the like. The totHSP value, said a sum of squares of each vector ^{((δD) 2 + (δP} ) 2 + (δH) 2).
The totHSP value can be calculated by software such as trade name: HSPiP.

The Hansen solubility parameters as the dispersion term (hereinafter, sometimes also referred to as "HSP value") ([delta] D), preferably ^{15 MPa 1/2} or more ^{18 MPa 1/2} or less.
As the HSP value of polarity term ([delta] P), preferably ^{6 MPa 1/2} or ^{14 MPa 1/2} or less, ^{6 MPa 1/2} or ^{11 MPa 1/2} or less is more preferable.
As the hydrogen bond of the HSP value (delta] H), preferably ^{6 MPa 1/2} or ^{25 MPa 1/2} or less, ^{6 MPa 1/2} or ^{13 MPa 1/2} or less is more preferable.

Examples of the organic solvent TotHSP value is ^{20 MPa 1/2} or more ^{23 MPa 1/2} or less, for example, 3-butoxy -N represented by the following structural formula (1), N-dimethyl propionamide (TotHSP value: 20. 2 MPa ^1/2 ), 3-methoxy-N, N-dimethylpropionamide represented by the following structural formula (2) (totHSP value: 22.5 MPa ^1/2 ), 3 represented by the following structural formula (3) - ethyl-3-hydroxymethyl oxetane (TotHSP value: 22.6MPa ^1/2), propylene glycol monopropyl ether (TotHSP value: 20.1MPa ^1/2), propylene glycol monomethyl ether (TotHSP value: 20.4MPa ^{1 / 2} ). These may be used individually by 1 type and may use 2 or more types together. Among these, 3-butoxy-N, N-dimethylpropionamide (totHSP value: 20.2 MPa ^1/2 ), 3-methoxy-N, N-dimethylpropionamide (totHSP value: 22.5 MPa ^1/2 ), etc. The amide solvent is preferred. By using an amide solvent such as 3-butoxy-N, N-dimethylpropionamide and 3-methoxy-N, N-dimethylpropionamide together with the urethane resin particles, the film-forming property of the urethane resin particles is promoted and higher resistance is obtained. Abrasion can be expressed. The amide solvent only needs to have an amide structure in its structure and includes the amides.

(Structural Formula (1): 3-Butoxy-N, N-dimethylpropionamide)

(Structural formula (2): 3-methoxy-N, N-dimethylpropionamide)

(Structural formula (3): 3-ethyl-3-hydroxymethyloxetane)

  The content of the organic solvent in the ink is not particularly limited and can be appropriately selected according to the purpose, but is preferably 10% by mass or more and 60% by mass or less from the viewpoint of the drying property and ejection reliability of the ink, 20 mass% or more and 60 mass% or less are more preferable.

  The content of the amide solvent in the ink is preferably 0.05% by mass or more and 10% by mass or less, and more preferably 0.1% by mass or more and 5% by mass or less.

The total Hansen solubility parameter of the organic solvent is 20 MPa ^1/2 or more 23 MPa ^1/2 or less, the content in the ink is not particularly limited and may be appropriately selected depending on the purpose, the ink From the viewpoint of storage stability, it is preferably 10% by mass to 60% by mass, more preferably 15% by mass to 60% by mass, and particularly preferably 15% by mass to 30% by mass with respect to the total amount of ink.

<Resin particles>
The type of resin particles contained in the ink is not particularly limited and can be appropriately selected according to the purpose. For example, urethane resin particles, polyester resin particles, acrylic resin particles, vinyl acetate resin particles, styrene series Examples thereof include resin particles, butadiene-based resin particles, styrene-butadiene-based resin particles, vinyl chloride-based resin particles, acrylic styrene-based resin particles, and acrylic silicone resin particles.
The resin particles can be mixed with a material such as a coloring material or an organic solvent in the state of a resin emulsion in which water is used as a dispersion medium to obtain an ink.
As said resin particle, what was synthesize | combined suitably may be used and a commercial item may be used. Moreover, these may be used individually by 1 type and may use 2 or more types together.

Among the resin particles, urethane resin particles are preferable from the viewpoint of improving scratch resistance.
Examples of the urethane resin particles include polycarbonate urethane resin particles, polyester urethane resin particles, and polyether urethane resin particles. These may be used individually by 1 type and may use 2 or more types together. Among these, polycarbonate urethane resin particles are preferable from the viewpoint of scratch resistance and storage stability. In addition, the said polycarbonate urethane resin particle should just have a polycarbonate structure in the structure, and is the meaning also including a polycarbonate-type urethane resin particle.

As said resin particle, what was synthesize | combined suitably may be used and a commercial item may be used. Examples of the commercially available product include, as acrylic resin particles, trade name: Saimak (manufactured by Toa Gosei Co., Ltd.), trade name: Boncoat (manufactured by DIC Corporation), trade name: Aqua Brid (manufactured by Daicel Corporation); acrylic silicone resin Product name: Cymac US480 (manufactured by Toa Gosei Co., Ltd., Martens hardness: 10 N / mm ² ); Particle name: U-coat (Daiichi Kogyo Seiyaku Co., Ltd.), product name: Takelac (Mitsui Chemicals, Inc.) Product name: Takelac WS-4000 (Martens hardness: 20 N / mm ² ), Product name: Takelac W-6061 (Martens hardness: 15 N / mm ² ), Product name: Takelac W-6110 (manufactured); Martens hardness: 10N / ^mm 2) (or more, Mitsui Chemicals stock Company Ltd.); trade name polyester urethane resin particles: Takelac WS5984 (manufactured by Mitsui Chemicals, Inc., Martens hardness: 1N / ^mm 2); tradename polyether urethane resin particles: Takelac W5661 (manufactured by Mitsui Chemicals, Inc., Martens hardness : 5 N / mm ² ). These may be used individually by 1 type and may use 2 or more types together. Among these, as a polycarbonate urethane resin particle, trade name: Takelac WS-4000 (Martens hardness: 20 N / mm ² ), trade name: Takelac W-6061 (Martens hardness: 15 N / mm ² ), trade name: Takelac W-6110 (Martens hardness: 10 N / mm ² ) is preferable.

Examples of the Martens hardness of the resin particles, from the viewpoint of abrasion resistance, preferably from 10 N / mm ² or less, 0.1 N / mm ² or more 10 N / mm ² or less being more preferred.
As the Martens hardness, a resin particle solution is coated on a support such as a slide glass (trade name: white plate glass S111, manufactured by Matsunami Glass Industry Co., Ltd.) so as to have an average thickness of 10 μm or more, and at 60 ° C. After preliminary drying for 3 hours, the resin film is obtained by drying at 100 ° C. for 6 hours. After the obtained resin film was pushed in for 10 seconds with a force of 1.0 mN using a micro hardness meter (device name: HM-2000, manufactured by Fischer Instruments Co., Ltd.) for 10 seconds, the resin film was held for 5 seconds. It can be measured by pulling out in 10 seconds with a force of 1.0 mN.

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

  The particle size of the solid content in the ink is not particularly limited and can be appropriately selected according to the purpose. From the viewpoint of improving the image quality such as ejection stability and image density, the maximum frequency in terms of the maximum number is converted. Is preferably 20 nm to 1000 nm, and more preferably 20 nm to 150 nm. 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 Microtrack Bell Co., Ltd.).

  The content of the resin particles is preferably 1% by mass or more and 30% by mass or less, and more preferably 5% by mass or more and 25% by mass or less with respect to the total amount of the inkjet ink.

The content of the acrylic resin particles is preferably 5% by mass or more and 30% by mass or less, and more preferably 6% by mass or more and 20% by mass or less with respect to the total amount of the ink jet ink.
The content of the urethane resin particles is preferably 1% by mass or more and 16% by mass or less, more preferably 1% by mass or more and 10% by mass or less, and more preferably 1% by mass or more and 4% by mass or less with respect to the total amount of the ink jet ink. Particularly preferred.

<Color material>
The color material is not particularly limited, and pigments and dyes can be used.
An inorganic pigment or an organic pigment can be used as the pigment. These may be used alone or in combination of two or more. 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 pigment such as gold or silver, a metallic pigment, or the like can be used.
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, chrome yellow as inorganic pigments Can be used.
Organic pigments include azo pigments, polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, quinofullerone pigments, etc.) Dye chelates (for example, basic dye type chelates, acidic dye type chelates), nitro pigments, nitroso pigments, aniline black, and the like can be used. Of these pigments, those having good affinity with the solvent are preferably used. In addition, resin hollow particles and inorganic hollow particles can also be used.
Specific examples of pigments include black for carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, or copper, iron (CI pigment black 11). And metal pigments such as titanium oxide and organic pigments such as aniline black (CI Pigment Black 1).
Further, for color use, 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 Carmine 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, 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 Green 1, 4, 7, 8, 10, 17, 18, 36, etc.
The dye is not particularly limited, and an acid dye, a direct dye, a reactive dye, and a basic dye can be used. One kind may be used alone, or two or more kinds may be used in combination.
Examples of the dye include 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. Food 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. Directed 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, and 35 are mentioned.

  The content of the color 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 improvement in image density, good fixability and ejection stability. It is as follows.

In order to disperse the pigment in the ink, a method of introducing a hydrophilic functional group into the pigment to form a self-dispersing pigment, a method of dispersing the pigment surface by coating with a resin, a method of dispersing using a dispersant, Etc.
Examples of a method for introducing a hydrophilic functional group into a pigment to form a self-dispersing pigment include a self-dispersing pigment that can be dispersed in water by adding a functional group such as a sulfone group or a carboxyl group to the pigment (for example, carbon). Can be used.
As a method for coating the surface of the pigment with a resin and dispersing it, a method in which the pigment is included in microcapsules and can be dispersed in water can be used. This can be paraphrased as a resin-coated pigment. In this case, it is not necessary that all pigments blended in the ink are coated with a resin, and within a range where the effects of the present invention are not impaired, uncoated pigments and partially coated pigments are dispersed in the ink. It may be.
Examples of the method of dispersing using a dispersant include a method of dispersing using a known low-molecular type dispersant or high-molecular type dispersant represented by a surfactant.
As the dispersant, for example, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant, or the like can be used depending on the pigment.
RT-100 (nonionic surfactant) manufactured by Takemoto Yushi Co., Ltd. and naphthalenesulfonic acid Na formalin condensate can also be suitably used as a dispersant.
A dispersing agent may be used individually by 1 type, or may use 2 or more types together.

<Pigment dispersion>
An ink can be obtained by mixing a material such as water or an organic solvent with a pigment. Further, it is also possible to produce an ink by mixing a pigment, other water, a dispersant, and the like into a pigment dispersion and mixing a material such as water or an organic solvent.
The pigment dispersion is obtained by dispersing water, a pigment, a pigment dispersant, and other components as required, and adjusting the particle size. For dispersion, a disperser is preferably used.
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 maximum number because the pigment dispersion stability is good and the image quality such as ejection stability and image density is also high. 500 nm or less is preferable and 20 nm or more and 150 nm or less are more preferable. The particle size of the pigment can be measured using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrack 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. However, from the viewpoint of obtaining good ejection stability and increasing the image density, 0.1% by mass. % To 50% by mass is preferable, and 0.1% to 30% by mass is more preferable.
The pigment dispersion is preferably degassed by filtering coarse particles with a filter, a centrifugal separator or the like, if necessary.

[Mass ratio (resin particles / coloring material)]
The mass ratio (resin particles / color material) of the resin particle content (% by mass) and the color material content (% by mass) is 0.5 from the viewpoint of scratch resistance and ejection stability. It is preferably 3.0 or more and more preferably 0.6 or more and 3.0 or less.

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

  There is no restriction | limiting in particular as said water, According to the objective, it can select suitably, For example, pure water, such as ion-exchange water, ultrafiltration water, reverse osmosis water, distilled water, ultrapure water, etc. are mentioned. . These may be used individually by 1 type and may use 2 or more types together.

The ink-jet ink of the present invention is an ink-jet ink containing an organic solvent, and the dynamic friction coefficient of a solid image ink film formed using the ink-jet ink is 0.35 or less. In differential scanning calorimetry, the product has an endothermic peak and an exothermic peak in the range of 100 ° C. or higher and 130 ° C. or lower, and the peak area of the exothermic peak is more than 0 J / g and 40 J / g or less.
The peak area of the exothermic peak of the solid material of the inkjet ink is more than 0 J / g and 40 J / g or less, and preferably 5 J / g or more and 30 J / g or less.
The ink contains other components such as water and a coloring material as necessary.

The organic solvent similar to the organic solvent described above can be used.
As the water, the same water as described above can be used.
As the color material, the same color material as described above can be used.

[Dynamic friction coefficient of ink film]
The dynamic friction coefficient of the ink film is 0.35 or less, preferably 0.20 or more and 0.35 or less, and more preferably 0.30 or more and 0.35 or less. When the dynamic friction coefficient is 0.35 or less, the slip property is improved and the image is hardly broken. In addition, since this effect can achieve the above-mentioned coefficient of dynamic friction with a small addition amount in the case of the polyethylene wax used in the present invention, there are no side effects such as ejection stability, ink storage stability, and image quality. Fixability can be dramatically improved.

The dynamic friction coefficient is vertical when an ink film (solid image) is formed on a recording medium (paper) at a temperature of 23 ° C. and a humidity of 50% RH, and the blank paper of the recording medium (paper) is aligned with the image. When an applied load is 20 g / cm ² and the friction is 60 mm at a speed of 1,200 mm / min, the average dynamic friction coefficient from 30 mm to 50 mm from the start position is defined as the dynamic friction coefficient of the image surface.
The dynamic friction coefficient can be measured using HEIDON TYPE 14DR (manufactured by Shinto Kagaku Co., Ltd.) as an apparatus. The recording medium can be measured using gloss coated paper. The gloss coated paper refers to paper having a 60 degree gloss of 20 or more, and preferably a paper having a 60 degree gloss of 20 to 30 can be used. As the gloss coated paper, for example, trade name: Lumi Art Gloss 130 gsm (manufactured by Stora Enso) can be used. The ink film (solid image) is formed by applying ink on the recording medium so that the ink adhesion amount is 1.0 mg / cm ^{2 to} 2.0 mg / cm ² (700 mg / A4 size). be able to. The ink adhesion amount is preferably 1.12 mg / cm ² (700 mg / A4 size).

  The dynamic friction coefficient is larger than 0.35 when the polyethylene wax is not added. However, by adding polyethylene wax, the dynamic friction coefficient on the surface of the image (ink film) can be reduced to 0.35 or less. When it is 0.35 or less as in the present invention, very good scratch resistance can be obtained.

[Endothermic peak and exothermic peak of solid matter or ink film of inkjet ink]
The solid matter obtained by drying and solidifying the ink-jet ink or the ink film (image) obtained after recording has an endothermic peak and an exothermic peak in the range of 100 ° C. to 130 ° C. in differential scanning calorimetry (DSC). And the exothermic peak has a peak area of more than 0 J / g and 40 J / g or less.
Among these, in differential scanning calorimetry (DSC), it has an endothermic peak in the range of 119 ° C. to 129 ° C. and an exothermic peak in the range of 107 ° C. to 117 ° C .; endothermic in the range of 107 ° C. to 117 ° C. It is preferable to have a peak and an exothermic peak in the range of 100 ° C. to 110 ° C.
The solid matter obtained by drying and solidifying the ink-jet ink can be prepared, for example, by dropping 3 mL of ink on a petri dish having a diameter of 3 cm and drying it in a thermostat at 70 ° C. for 5 hours. Further, the ink film can be collected by peeling off the ink film (image) obtained after recording with a razor from the recording medium.
The measuring method of the endothermic peak, the exothermic peak, and the peak area of the exothermic peak can be measured in the same manner as the measuring method of polyethylene wax.

Also, the dynamic friction coefficient is 0.35 or less, and the result of DSC of the solid matter or ink film of the ink-jet ink falls within the above numerical range unless the polyethylene wax is the penetration range in the present invention. Can't get. Reducing the dynamic friction coefficient can improve the scratch resistance, but in order to make the dynamic friction coefficient 0.35 or less, the polyethylene wax having a penetration of greater than 1.2 must have a higher content than the polyethylene wax of the present invention. I must.
The peak area of the exothermic peak of DSC in the solid matter obtained by drying and solidifying the ink-jet ink or the ink film (image) obtained after recording is the peak area of the exothermic peak of polyethylene wax alone relative to the ink solid content. It is almost the same as the value multiplied by the polyethylene wax content.
The peak area of the exothermic peak of the polyethylene wax alone having a penetration of greater than 1.2 is smaller than the peak area of the exothermic peak of the polyethylene wax in the inkjet ink of the present invention, but the polyethylene wax content relative to the ink solid content concentration If the amount is not increased, the dynamic friction coefficient does not become 0.35 or less, and the peak area of the exothermic peak when the dynamic friction coefficient becomes 0.35 or less is larger than 40 J / g.
With the polyethylene wax used in the inkjet ink of the present invention, the dynamic friction coefficient can be reduced to 0.35 or less even when the content is very small, and the scratch resistance can be greatly improved. Side effects such as deterioration in storage stability and ejection stability due to the inclusion of the wax can be avoided.

<Additives>
If necessary, a surfactant, an antifoaming agent, an antiseptic / antifungal agent, a rust inhibitor, a pH adjuster, and the like may be added to the ink.

<Surfactant>
As the surfactant, any of silicone surfactants, fluorine surfactants, amphoteric surfactants, nonionic surfactants and anionic surfactants can be used.
There is no restriction | limiting in particular in silicone type surfactant, According to the objective, it can select suitably. Among them, those that do not decompose even at high pH are preferable, and examples thereof include side chain modified polydimethylsiloxane, both terminal modified polydimethylsiloxane, one terminal modified polydimethylsiloxane, and side chain both terminal modified polydimethylsiloxane. Those having an oxyethylene group or a polyoxyethylene polyoxypropylene group are particularly preferred because they exhibit good properties as an aqueous surfactant. In addition, as the silicone surfactant, a polyether-modified silicone surfactant can be used, and examples thereof include a compound in which a polyalkylene oxide structure is introduced into the side chain of the Si portion of dimethylsiloxane.
Examples of the fluorosurfactant include a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic acid compound, a perfluoroalkyl phosphate compound, a perfluoroalkyl ethylene oxide adduct, and a perfluoroalkyl ether group in the side chain. Polyoxyalkylene ether polymer compounds are particularly preferred because of their low foaming properties. Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid, perfluoroalkyl sulfonate, and the like. Examples of the perfluoroalkylcarboxylic acid compound include perfluoroalkylcarboxylic acid and perfluoroalkylcarboxylate. Examples of the polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain include 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. As counter ions of salts in these fluorosurfactants, Li, Na, K, NH ₄ , NH ₃ CH ₂ CH ₂ OH, NH ₂ (CH ₂ CH ₂ OH) ₂ , NH (CH ₂ CH ₂ OH) ₃ etc. are mentioned.
Examples of amphoteric surfactants include lauryl aminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, and lauryl dihydroxyethyl betaine.
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 the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, laurate, polyoxyethylene alkyl ether sulfate salt, and the like.
These may be used alone or in combination of two or more.

The silicone surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, side chain modified polydimethylsiloxane, both terminal modified polydimethylsiloxane, one terminal modified polydimethylsiloxane, side Since both ends of the chain are modified with polydimethylsiloxane, a polyether-modified silicone surfactant having a polyoxyethylene group or a polyoxyethylene polyoxypropylene group as a modifying group exhibits good properties as an aqueous surfactant. preferable.
As such a surfactant, an appropriately synthesized product or a commercially available product may be used. Commercially available products can be obtained from, for example, Big Chemie Co., Ltd., Shin-Etsu Chemical Co., Ltd., Toray Dow Corning Silicone Co., Ltd., Nippon Emulsion Co., Ltd., and Kyoeisha Chemical Co., Ltd.
There is no restriction | limiting in particular as said polyether modified silicone surfactant, According to the objective, it can select suitably, For example, the polyalkylene oxide structure represented by a general formula (S-1) type | formula is dimethylpolyethylene. Examples thereof include those introduced into the side chain of Si part of siloxane.
Formula (S-1)
(In the general formula (S-1), m, n, a, and b represent integers. R and R ′ represent an alkyl group and an alkylene group.)
A commercial item can be used as said polyether modified silicone type surfactant, For example, KF-618, KF-642, KF-643 (Shin-Etsu Chemical Co., Ltd.), EMALEX-SS-5602, SS- 1906EX (Japan Emulsion Co., Ltd.), FZ-2105, FZ-2118, FZ-2154, FZ-2161, FZ-2162, FZ-2163, FZ-2164 (Toray Dow Corning Silicone Co., Ltd.), BYK-33, BYK-387 (Bic Chemie Co., Ltd.), TSF4440, TSF4452, TSF4453 (Toshiba Silicon Co., Ltd.), etc. are mentioned.

As the fluorine-based surfactant, a fluorine-substituted compound having 2 to 16 carbon atoms is preferable, and a fluorine-substituted compound having 4 to 16 carbon atoms is more preferable.
Examples of the fluorosurfactant include perfluoroalkyl phosphate compounds, perfluoroalkylethylene oxide adducts, and polyoxyalkylene ether polymer compounds having a perfluoroalkyl ether group in the side chain. Among these, a polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain is preferable because of its low foaming property, and in particular, fluorine-based compounds represented by the general formulas (F-1) and (F-2) A surfactant is preferred.
Formula (F-1)
In the compound represented by the general formula (F-1), m is preferably an integer of 0 to 10 and n is preferably an integer of 0 to 40 in order to impart water solubility.
Formula (F-2)
_{C n F 2n + 1- CH 2} CH (OH) CH 2 -O- (CH 2 CH 2 O) a -Y
In the compound represented by the general formula (F-2), Y is H, or CnF _{2n + 1} , n is an integer of 1 to 6, or CH ₂ CH (OH) CH ₂ —CnF _{2n + 1,} where n is 4 to 6. An integer, or CpH _{2p + 1} , p is an integer of 1-19. a is an integer of 4-14.
A commercial item may be used as said fluorosurfactant. As this commercial item, for example, Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, S-145 (all manufactured by Asahi Glass Co., Ltd.); Fullrad FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M Limited); Megafac F-470, F -1405, F-474 (all manufactured by Dainippon Ink & Chemicals, Inc.); Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR (all FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW (all are corporations) (Manufactured by Male), Polyfox PF-136A, PF-156A, PF-151N, PF-154, PF-159 (Omnova), Unidyne DSN-403N (Daikin Industries, Ltd.), and the like. Among these, FS-300 manufactured by Du Pont, FT-110, FT-250 manufactured by Neos Co., Ltd., and the like, have excellent print quality, particularly color developability, paper permeability, wettability, and leveling. FT-251, FT-400S, FT-150, FT-400SW, Polyfox PF-151N manufactured by Omninova, and Unidyne DSN-403N manufactured by Daikin Industries, Ltd. are particularly preferable.

  There is no restriction | limiting in particular as content of surfactant in an ink, Although it can select suitably according to the objective, From the point which is excellent in wettability and discharge stability, and image quality improves, it is 0.001 mass. % To 5% by mass is preferable, and 0.05% to 5% by mass is more preferable.

<Antifoaming agent>
There is no restriction | limiting in particular as an antifoamer, For example, a silicone type antifoamer, a polyether type | system | group antifoamer, a fatty-acid ester type | system | group antifoamer etc. are mentioned. These may be used alone or in combination of two or more. Among these, a silicone type antifoaming agent is preferable from the viewpoint of excellent foam breaking effect.

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

<Rust preventive>
There is no restriction | limiting in particular as a rust preventive agent, For example, acidic sulfite, sodium thiosulfate, etc. are mentioned.

<PH adjuster>
The pH adjuster is not particularly limited as long as the pH can be adjusted to 7 or more, and examples thereof include amines such as diethanolamine and triethanolamine.

There is no restriction | limiting in particular as a physical property of an ink, According to the objective, it can select suitably, For example, it is preferable that a viscosity, surface tension, pH, etc. are the following ranges.
The viscosity at 25 ° C. of the ink is preferably 5 mPa · s or more and 30 mPa · s or less, preferably 5 mPa · s or more and 25 mPa · s or less from the viewpoint of improving the printing density and character quality and obtaining good discharge properties. More preferred. Here, for the viscosity, for example, a rotary viscometer (RE-80L manufactured by Toki Sangyo Co., Ltd.) can be used. Measurement conditions are 25 ° C., standard cone rotor (1 ° 34 ′ × R24), sample liquid amount 1.2 mL, rotation speed 50 rpm, and measurement is possible for 3 minutes.
The surface tension of the ink is preferably 35 mN / m or less and more preferably 32 mN / m or less at 25 ° C. from the viewpoint that the ink is suitably leveled on the recording medium and the drying time of the ink is shortened.
The pH of the ink is preferably 7 to 12 and more preferably 8 to 11 from the viewpoint of preventing corrosion of the metal member in contact with the liquid.

[Method for producing ink-jet ink]
As a method for producing the inkjet ink, for example, the water, the organic solvent, the coloring material, the polyethylene wax, and, if necessary, the resin particles and the additive are produced by stirring and mixing. Can do. As the stirring and mixing, for example, a sand mill, a homogenizer, a ball mill, a paint shaker, an ultrasonic disperser, a stirrer using a normal stirrer blade, a magnetic stirrer, a high-speed disperser, or the like can be used.

<Recording medium>
The recording medium used for recording is not particularly limited, and examples thereof include plain paper, glossy paper, special paper, cloth, film, OHP sheet, and general-purpose printing paper.

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

Further, the recorded matter is a recorded matter having a recording medium and an ink film formed on the recording medium with an ink including a color material, and the dynamic friction coefficient of the ink film is 0.35 or less. In the differential scanning calorimetry, the ink film has an endothermic peak and an exothermic peak in a range of 100 ° C. to 130 ° C., and a peak area of the exothermic peak is more than 0 J / g and 40 J / g or less.
The recorded matter of the present invention can be suitably obtained by recording an image (ink film) using the inkjet ink of the present invention.

The ink film has an endothermic peak and an exothermic peak in a range of 100 ° C. or higher and 130 ° C. or lower in differential scanning calorimetry, an endothermic peak in a range of 119 ° C. or higher and 129 ° C. or lower, and a range of 107 ° C. or higher and 117 ° C. or lower. Preferably have an endothermic peak in the range of 107 ° C. or higher and 117 ° C. or lower, and an exothermic peak in the range of 100 ° C. or higher and 110 ° C. or lower, preferably in the range of 119 ° C. or higher and 129 ° C. or lower. More preferably, it has an exothermic peak in the range of 117 ° C. or lower. The ink film can be collected by peeling off the ink film (image) obtained after recording with a razor and peeling it from the recording medium. The endothermic peak, the exothermic peak, and the peak area value of the exothermic peak in the differential scanning calorimetry of the ink film (image) collected by peeling from the recording medium are the endothermic in the differential scanning calorimetry of the solid matter of the ink. This is the same as the value of the peak, the exothermic peak, and the peak area of the exothermic peak.
The measuring method of the endothermic peak, the exothermic peak, and the peak area of the exothermic peak can be measured in the same manner as the measuring method of polyethylene wax.

The dynamic friction coefficient of the ink film is 0.35 or less, preferably 0.02 or more and 0.35 or less.
The dynamic friction coefficient can be measured using HEIDON TYPE 14DR (manufactured by Shinto Kagaku Co., Ltd.) as an apparatus.
The peak area of the exothermic peak of the ink film is more than 0 J / g and 40 J / g or less, and preferably 5 J / g or more and 30 J / g or less.

  The ink film preferably includes a spectrum in which the mass spectrum detected by pyrolysis GC-MS measurement matches the mass spectrum of 1.2-propanediol. The ink film can be collected by peeling off the ink film (image) obtained after recording with a razor and peeling it from the recording medium. Examples of the pyrolysis gas chromatograph mass spectrometer used in the pyrolysis gas chromatography mass spectrometry include a thermal analyzer (device name: Py-3030D, manufactured by Frontier Laboratories), GC analyzer (device name: 7890B (manufactured by Agilent Technologies) and MS analyzer (device name: Q1500, manufactured by JEOL Ltd.) can be used for measurement.

<Ink container>
The ink container of the present invention contains the ink-jet ink of the present invention in a container, and further includes other members appropriately selected as necessary.
The container is not particularly limited, and its shape, structure, size, material and the like can be appropriately selected according to the purpose. For example, at least an ink bag formed of an aluminum laminate film, a resin film, or the like What has is mentioned suitably.

<Recording apparatus and recording method>
The ink of the present invention can be suitably used for various recording apparatuses using an ink jet recording method, such as a printer, a facsimile apparatus, a copying apparatus, a printer / fax / copier complex machine, and a three-dimensional modeling apparatus.
In the present invention, the recording apparatus and the recording method are an apparatus capable of ejecting ink, various treatment liquids, and the like to a recording medium, and a method of performing recording using the apparatus. The recording medium means a medium on which ink or various processing liquids can be temporarily attached.
The recording apparatus can include not only a head portion that ejects ink but also means for feeding, transporting, and discharging a recording medium, and other devices called pre-processing devices and post-processing devices. .
The recording apparatus and the recording method may include a heating unit used in the heating step and a drying unit used in the drying step. The heating means and the drying means include, for example, a means for heating and drying the printing surface and the back surface of the recording medium. Although it does not specifically limit as a heating means and a drying means, For example, a warm 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 apparatus and the recording method are not limited to those in which significant images such as characters and figures are visualized by ink. For example, what forms patterns, such as a geometric pattern, etc. includes what forms a three-dimensional image.
Further, the recording apparatus includes both a serial type apparatus that moves the ejection head and a line type apparatus that does not move the ejection head, unless otherwise specified.
Furthermore, this recording apparatus can use not only a desktop type but also a wide recording apparatus that can print on an A0 size recording medium, for example, a continuous paper wound up in a roll shape as a recording medium. Also included are continuous paper printers.
An example of the recording apparatus will be described with reference to FIGS. FIG. 1 is a perspective view of the apparatus. FIG. 2 is an explanatory perspective view of the main tank. An image forming apparatus 400 as an example of a recording apparatus is a serial type image forming apparatus. A mechanism unit 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), yellow (Y) is packaged, for example, an aluminum laminate film It is formed by a member. The ink storage unit 411 is stored 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 on the inner 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. Thus, the ink discharge ports 413 of the main tank 410 and the discharge heads 434 for the respective colors communicate with each other via the supply tubes 436 for the respective colors, and ink can be discharged from the discharge heads 434 to the recording medium.

The recording apparatus can include not only a portion that ejects ink but also a device called a pre-processing device or a post-processing device.
As one mode of the pretreatment device and the posttreatment device, as in the case of inks such as black (K), cyan (C), magenta (M), and yellow (Y), a pretreatment liquid and a posttreatment liquid are included. There is a mode in which a liquid container and a liquid discharge head are added, and a pretreatment liquid and a posttreatment liquid are discharged by an ink jet recording method.
As another aspect of the pretreatment apparatus and the posttreatment apparatus, there is an aspect in which, for example, a pretreatment apparatus or a posttreatment apparatus other than the ink jet recording method is provided by a blade coating method, a roll coating method, or a spray coating method.

  The method of using the ink is not limited to the ink jet recording method, and can be widely used. Besides the ink jet recording method, for example, a blade coating method, a gravure coating method, a bar coating method, a roll coating method, a dip coating method, a curtain coating method, a slide coating method, a die coating method, a spray coating method and the like can be mentioned.

The use of the ink of the present invention is not particularly limited and can be appropriately selected depending on the purpose. For example, it can be applied to printed materials, paints, coating materials, foundations and the like. Furthermore, it can be used not only to form two-dimensional characters and images using ink, but also as a three-dimensional modeling material for forming a three-dimensional three-dimensional image (three-dimensional modeled object).
A known three-dimensional modeling apparatus for modeling a three-dimensional model can be used, and is not particularly limited. For example, a three-dimensional modeling apparatus including an ink storage unit, a supply unit, a discharge unit, a drying unit, or the like is used. be able to. The three-dimensional structure includes a three-dimensional structure obtained by repeatedly applying ink. Further, a molded product obtained by processing a structure provided with ink on a substrate such as a recording medium is also included. The molded product is obtained by subjecting a recorded material or a structure formed in a sheet shape or a film shape to a molding process such as heat stretching or punching, for example, an automobile, an OA device, an electric -It is suitably used for applications in which surfaces are decorated after decorating, such as meters for electronic devices, cameras, etc., and panels for operation units.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

  Further, the penetration of the wax and the Martens hardness, the differential scanning calorimetry of the solid matter of the wax and the ink, and the pyrolysis gas chromatography of the solid matter of the ink were measured as follows.

<Wax penetration>
The penetration of the wax was measured according to JIS K2235. As the penetration meter, an automatic penetration tester (device name: RPM-201, manufactured by Rai Co., Ltd.) was used.
As a measurement sample, 100 g of a dried product obtained by drying a wax emulsion at 70 ° C. was put in a pan, melted at a temperature 20 ° C. higher than the melting point, and then solidified by natural cooling to obtain a wax solidified product. At this time, it was confirmed that the surface of the measurement sample was smooth. After solidifying, the sample (wax-solidified product) was set on a testing machine so that the surface in contact with the pan could be stabbed with a needle. The sample (wax-solidified product) was pushed in for 5 seconds using a needle with a weight of 50 g in a 25 ° C. environment, and the penetration was measured. The needle used for the measurement is conical stainless steel, and the surface roughness of the needle is 0.2 μm or less. In the projection, the tip of the cone is at an angle of 9 °, and the weight of the needle is 2.5 g.

<Martens hardness of wax>
The polyethylene wax has a Martens hardness of polyethylene wax coated on a slide glass (trade name: white plate glass S1111 manufactured by Matsunami Glass Industry Co., Ltd.) so as to have an average thickness of 10 μm or more, and at 60 ° C. for 3 hours. After preliminary drying, it was dried at 100 ° C. for 6 hours to obtain a wax solidified product. Using a micro hardness tester (device name: HM-2000, manufactured by Fischer Instruments Co., Ltd.), the obtained wax solidified product was pushed in by a Vickers indenter with a force of 1.0 mN for 10 seconds and held for 5 seconds. Then, it measured by pulling out in 10 second with the force of 1.0 mN. The measurement was performed at a temperature of 23 ° C. and a humidity of 55% RH.

<Differential scanning calorimetry of wax and inkjet ink solids>
Differential scanning calorimetry (DSC) of the wax and the solid matter of the ink-jet ink was performed as follows using a high-sensitivity differential scanning calorimeter (device name: Thermo plus EV02, manufactured by Rigaku Corporation).
When measuring the wax, 3 mL of a polyethylene wax emulsion was dropped into a petri dish having a diameter of 3 cm, dried for 5 hours using a thermostatic bath at 70 ° C., 10 mg of a wax solidified product (sample) was taken and placed in a sample pan. In addition, as a reference to that put powder _Al 2 _{O 3} to 10mg sample pan. A sample and a reference are set in a measurement cell, heated from 25 ° C. to 100 ° C. at 10 ° C./min, from 100 ° C. to 170 ° C. at 5 ° C./min, from 170 ° C. to 100 ° C. at 5 ° C./min, 100 The measurement was performed by lowering the temperature from 10 ° C. to 25 ° C. at 10 ° C./min.
As the peak area of the exothermic peak, using the analysis software of a high-sensitivity differential scanning calorimeter (device name: Thermo plus EV02, manufactured by Rigaku Corporation), the peak position of the exotherm and two points serving as a base are selected, The area was calculated by The exothermic peak has a maximum value in a range of 100 ° C. or higher and 130 ° C. or lower, and two points serving as a base include a minimum temperature between + 20 ° C. and −20 ° C. of the peak temperature of the maximum value. The minimum temperature between, and was taken.
Similarly, when measuring the solid matter of ink-jet ink, 3 mL of ink is dropped on a petri dish having a diameter of 3 cm and dried for 5 hours using a thermostat at 70 ° C., and a dried ink is prepared. It measured similarly to the time of measuring.
The positions of the endothermic peak and the exothermic peak in the differential scanning calorimetry of the wax were the same as the positions of the endothermic peak and the exothermic peak in the differential scanning calorimetry of the solid matter of the inkjet ink.

<Pyrolysis Gas Chromatography of Solid Ink for Inkjet>
The thermal decomposition gas chromatography (Py-GC-MS) of the solid matter of the ink-jet ink collected by peeling off the ink film (image) obtained after the recording with a razor and separating it from the recording medium is a thermal analyzer (device). Name: Py-3030D, manufactured by Frontier Laboratories), GC analyzer (device name: 7890B, manufactured by Agilent Technologies), MS analyzer (device name: Q1500, manufactured by JEOL Ltd.) The following procedure was carried out using the apparatus.
Thermal decomposition was performed at a heating temperature of 180 ° C. and a thermal decomposition temperature of 600 ° C. using a thermal analyzer (device name: Py-3030D, manufactured by Frontier Laboratories). The column used in the gas chromatography was UltraALLOY + 5 (length: 30.0 m, internal total: 0.25 mm, film thickness: 0.25 μm, manufactured by Frontier Laboratories), and the temperature condition was 50 ° C. The temperature was maintained for 2 minutes, the temperature was raised from 50 ° C. to 280 ° C. (temperature increase rate: 20 ° C./min), and the temperature was maintained at 280 ° C. for 11.5 minutes. Mass spectrometry used the apparatus name: Q1500 (made by JEOL Ltd.). The mass spectrometric measurement conditions were the electron impact ionization method (EI method) of 70 eV and the mass measurement range: m / z = 20 to 800 (m: mass, z: charge). In the data analysis, the spectrum obtained by the Py-GC-MS was qualitatively analyzed by collating with data analysis software (manufactured by National Institute of Standards and Technology (NIST)).

(Preparation of pigment dispersion)
<Preparation of cyan pigment dispersion>
A cyan pigment dispersion was obtained in the same manner as described in -Method A- of [Pigment surface modification treatment] in JP2012-207202A.
Specifically, C.I. I. Pigment Blue 15: 3 (trade name: Chromo Fine Blue, manufactured by Dainichi Seika Kogyo Co., Ltd.), 20 mmol of the compound of the following structural formula (5), and 200 mL of ion-exchanged water were placed in a Silverson mixer (6,000 rpm) under room temperature. (0.6% by mass)) to obtain a slurry. If the pH of the resulting slurry is higher than 4, 20 mmol of nitric acid is added. After 30 minutes, sodium nitrite (20 mmol) dissolved in a small amount of ion exchange water was slowly added to the slurry. Further, the mixture was heated to 60 ° C. with stirring and reacted for 1 hour. I. A modified pigment in which a compound of the following structural formula (5) was added to the surface of Pigment Blue 15: 3 was obtained. Subsequently, the modified pigment dispersion was obtained after 30 minutes by adjusting the pH to 10 with an aqueous NaOH solution. Using the modified pigment dispersion and ion-exchanged water, ultrafiltration using a dialysis membrane is performed, and ultrasonic dispersion is further performed to have a bisphosphonic acid group as a hydrophilic functional group with a pigment concentration of 15 mass% A cyan pigment dispersion (self-dispersing type) was obtained.
-Structural formula (5)-

Example 1
Cyan pigment dispersion 15.0% by mass, 3-ethyl-3-hydroxymethyloxetane (Ube Industries, Ltd., totHSP value: 22.6 MPa ^1/2 ) 15.0% by mass, 1,2-propanediol (product) Name: Propylene glycol for industrial use, manufactured by ADEKA Corporation, totHSP value: 29.1 MPa ^1/2, 15.0 mass%, polycarbonate urethane resin particle 1 (trade name: Takelac W6110, manufactured by Mitsui Chemicals, Martens hardness: 10 N / Mm ² ) polycarbonate urethane resin particle 1 liquid (solid content concentration: 30% by mass) 5.0% by mass, polyethylene wax 1 (trade name: Aqua Petro DP2502-C, manufactured by Toyo Adre Co., Ltd., melting point: 126 ° C) polyethylene wax 1 emulsion (solid content concentration: 30% by mass) 2.0 After mixing and stirring the remaining amount of ion-exchanged water so that the total amount becomes 100% by mass, the polyether-modified siloxane copolymer (trade name: TEGO Wet270, manufactured by Sakai Kogyo Co., Ltd.) 2.0% by mass, the average pore size Was filtered with a 0.8 μm membrane filter (trade name: DISMIC-25cs, manufactured by Advantech) to obtain inkjet ink 1. The physical properties of the inkjet ink 1 are shown in Table 5 below. In addition, FIG. 3 shows the results of differential scanning calorimetry (DSC) measurement of the polyethylene wax 1 (trade name: Aqua Petro DP2502-C, manufactured by Toyo Adre Co., Ltd.).

(Examples 2 to 22 and Comparative Examples 1 to 6)
In Example 1, except that the composition and content were changed to the compositions and contents shown in Tables 1 to 4, in the same manner as in Example 1, Examples 2 to 22 and Comparative Examples 1 to 6 were used for inkjet inks 2 to 2. 28 was obtained. The physical properties of inkjet inks 2 to 28 are shown in Table 5 below. Moreover, the result of the DSC measurement of polyethylene wax 2 (trade name: Aqua Petro DP2401, manufactured by Toyo Adre Co., Ltd.) is shown in FIG.
In Comparative Examples 1 to 6, the penetration of the wax is 1.3 or more and 10 or less, and the dynamic friction coefficient of the ink film is 0.36 or more and 0.42 or less. The degree is 1.2 or less and the dynamic friction coefficient of the ink film is not within the range of 0.35 or less.

Note that the differential scanning calorimetry was used to measure the endothermic peak, the exothermic peak, and the peak area of the exothermic peak in the ink film. Similar results were obtained.

In addition, in the said Tables 1-4, the brand name of a component and the manufacturer name are as follows.
<Organic solvent>
・ 3-Ethyl-3-hydroxymethyloxetane (trade name: EHO, Ube Industries, Ltd., totHSP value: 22.6 MPa ^1/2 )
Propylene glycol monomethyl ether (trade name: 1-methoxy-2-propanol, manufactured by Tokyo Chemical Industry Co., Ltd., totHSP value: 20.4 MPa ^1/2 )
Propylene glycol monopropyl ether (trade name: 1-propoxy-2-propanol, manufactured by Tokyo Chemical Industry Co., Ltd., totHSP value: 20.1 MPa ^1/2 )
・ 3-Butoxy-N, N-dimethylpropionamide (trade name: Ecamide B100, Idemitsu Kosan Co., Ltd., totHSP value: 20.2 MPa ^1/2 )
・ 3-Methoxy-N, N-dimethylpropionamide (trade name: Ecamide M100, manufactured by Idemitsu Kosan Co., Ltd., totHSP value: 22.5 MPa ^1/2 )
1,2-propanediol (trade name: industrial propylene glycol, manufactured by ADEKA Corporation, totHSP value: 29.1 MPa ^1/2 )
・ 1,3-propanediol (trade name: Sustena propanediol, manufactured by DuPont, totHSP value: 31.7 MPa ^1/2 )

<Resin particles>
<< Acrylic resin particles >>
Acrylic silicone resin particles: manufactured by Toa Gosei Co., Ltd., trade name: Cymac US480, Martens hardness: 10 N / mm ²
<< Urethane resin particles >>
Polycarbonate urethane resin particles 1: manufactured by Mitsui Chemicals, trade name: Takelac W6110, Martens hardness: 10 N / mm ²
Polycarbonate urethane resin particles 2: manufactured by Mitsui Chemicals, trade name: Takelac WS4000, Martens hardness: 20 N / mm ²
Polycarbonate urethane resin particles 3: manufactured by Mitsui Chemicals, Inc., trade name: Takelac W6061, Martens hardness: 15 N / mm ²
Polyester urethane resin particles: manufactured by Mitsui Chemicals, Inc., trade name: Takelac WS 5984, Martens hardness: 1 N / mm ²
Polyether urethane resin particles: manufactured by Mitsui Chemicals, Inc., trade name: Takelac W5661 Martens hardness: 5 N / mm ²
The resin particles were diluted with ion-exchanged water and added so that the solid content concentration was 30% by mass.

<Wax>
Polyethylene wax 1 emulsion: manufactured by Toyo Adre Co., Ltd., trade name: Aqua Petro DP2502-C, penetration: 0.5, Martens hardness: 73 N / mm ² , melting point 126 ° C.
Polyethylene wax 2 emulsion: manufactured by Toyo Adre Co., Ltd., trade name: Aqua Petro DP2401, penetration: 1.0, Martens hardness: 51 N / mm ² , melting point 110 ° C.
Polyethylene wax 3 emulsion: manufactured by Big Chemie, trade name: AQUACER 531, penetration: 2.0, Martens hardness: 36 N / mm ² , melting point 130 ° C.
Polyethylene wax 4 emulsion: manufactured by Big Chemie, trade name: AQUACER 515, penetration: 1.7, Martens hardness: 40 N / mm ² , melting point 135 ° C.
Polyethylene wax 5 emulsion: manufactured by Mitsui Chemicals, trade name Chemipearl 4005, penetration: 3, Martens hardness: 25 N / mm ² , melting point 110 ° C.
Paraffin wax emulsion: manufactured by Big Chemie, trade name: AQUACER 537, penetration: 10, Martens hardness: 1 N / mm ² , melting point 110 ° C.
Polypropylene wax emulsion: manufactured by Big Chemie, trade name: AQUACER 593, penetration: 1.3, Martens hardness: 10 N / mm ² , melting point 160 ° C.
The wax was diluted with ion-exchanged water and added so that the solid content concentration was 30% by mass.

  Next, using the ink, the “dynamic friction coefficient of ink film”, “scratch resistance”, “ejection stability”, “storage stability”, “image density”, and “glossiness” are as follows. Was evaluated. The results are shown in Table 6.

<Dynamic friction coefficient of ink film>
Apparatus: HEIDON TYPE 14DR (manufactured by Shinto Kagaku Co., Ltd.) is used, and the amount of ink adhesion is 1. An ink film of 12 mg / cm ² (700 mg / A4 size) is formed, the white paper is combined with the image, a vertical load of 20 g / cm ² is applied, and friction is performed by 60 mm at a speed of 1,200 mm / min. The average dynamic friction coefficient was measured from 30 mm to 50 mm from the start position.

<Abrasion resistance under normal temperature and humidity>
Each ink was filled in an ink jet printer (device name: IPSIO GX5500, manufactured by Ricoh Co., Ltd.) in an environment of room temperature 25 ° C. and humidity 50% RH (room temperature and normal humidity environment). Next, paper (trade name: Lumi Art Gloss 130 gsm, manufactured by Stora Enso) is set in the inkjet printer, and the ink adhesion amount is 1.12 mg / cm ² (700 mg / A4 size), and 1,200 dpi × 1. , A solid image (ink film) was recorded at a resolution of 200 dpi. After drying at 100 ° C. for 1 minute and using the paper (trade name: Lumi Art Gloss 130 gsm, manufactured by Stora Enso) cut into a 1.2 cm square, the environment (normal temperature normal temperature) at room temperature 25 ° C. In a humidity environment, the solid part was rubbed 20 times with a load of 400 g. Thereafter, the ink adhesion stain on the paper was measured using a reflective color spectrocolorimetric densitometer (device name: X-Rite eXact, manufactured by X-Rite), and the density obtained by subtracting the background color of the rubbed paper. Was calculated, and “scratch resistance” was evaluated based on the following evaluation criteria. In addition, B or more is an allowable range, and A or more is a more preferable range.
-Evaluation criteria-
A: The concentration is less than 0.05 A: The concentration is 0.05 or more and less than 0.10 B: The concentration is 0.10 or more and less than 0.15 C: The concentration is 0.15 or more and less than 0.20 D: Concentration is 0.20 or more

<Abrasion resistance under high temperature and low humidity>
Each ink was filled in an ink jet printer (device name: IPSIO GX5500, manufactured by Ricoh Co., Ltd.) in an environment of room temperature 25 ° C. and humidity 50% RH (room temperature and normal humidity environment). Next, paper (trade name: Lumi Art Gloss 130 gsm, manufactured by Stora Enso) is set in the inkjet printer, and the ink adhesion amount is 1.12 mg / cm ² (700 mg / A4 size), and 1,200 dpi × 1. , A solid image (ink film) was recorded at a resolution of 200 dpi. Using the paper (trade name: Lumi Art Gloss 130 gsm, manufactured by Stora Enso) cut to 1.2 cm square after drying at 100 ° C. for 1 minute, the environment (high temperature and low temperature) at 40 ° C. and humidity 10% In a humidity environment, the solid part was rubbed 20 times with a load of 400 g. Thereafter, the ink adhesion stain on the paper was measured using a reflective color spectrocolorimetric densitometer (device name: X-Rite eXact, manufactured by X-Rite), and the density obtained by subtracting the background color of the rubbed paper. Was calculated, and “scratch resistance” was evaluated based on the following evaluation criteria. In addition, B or more is an allowable range, and A or more is a more preferable range.
-Evaluation criteria-
A: The concentration is less than 0.05 A: The concentration is 0.05 or more and less than 0.10 B: The concentration is 0.10 or more and less than 0.15 C: The concentration is 0.15 or more and less than 0.20 D: Concentration is 0.20 or more

<Discharge stability>
Each ink was filled in the ink jet printer, and the ink jet printer was allowed to stand for 24 hours in a decap state using a constant temperature bath at 40 ° C. Thereafter, the sample was taken out, head refreshing was performed from the printer driver, and “ejection stability” was evaluated based on the following evaluation criteria. In addition, B or more is an allowable range.
-Evaluation criteria-
AA: Ink is ejected from all nozzles when head refreshing is less than 4 times A: Ink is ejected from all nozzles when head refreshing is 4 times or more and less than 7 times B: Ink is ejected from all nozzles when head refreshing is 7 times or more and less than 10 times Yes C: Ink is ejected from all nozzles after head refreshing 10 times or more

<Storage stability>
The next day after preparation of the ink jet ink, 1.1 mL of the ink jet ink is collected, put into a sample cup of the rotary viscometer, attached to the main body of the rotary viscometer and left to stand for 1 minute, and then the rotor of the rotary viscometer is rotated. The value after 1 minute was read (initial viscosity). The rotational speed at the time of measuring the viscosity was adjusted so that the torque was constant within a range of 40% to 80%. Next, the ink for inkjet was filled in a 50 mL polypropylene container (trade name: Eyeboy Wide Mouth Bottle, manufactured by ASONE), stored at 23 ° C. for 2 weeks, and then measured for viscosity in the same manner as the initial viscosity (viscosity after storage). . These viscosity values were applied to the following formula to calculate the viscosity change rate, and “storage stability” was evaluated based on the following evaluation criteria. In addition, B or more is an allowable range. The viscosity was measured at 25 ° C. using a rotational viscometer (device name: RE80L, cone plate type, manufactured by Toki Sangyo Co., Ltd.).
Viscosity change rate (%) = | [(viscosity after storage−initial viscosity) / initial viscosity] | × 100
-Evaluation criteria-
AA: Viscosity change rate is less than 1% A: Viscosity change rate is 1% or more and less than 3% B: Viscosity change rate is 3% or more and less than 5% C: Viscosity change rate is 5% or more

<Image density>
64 point character JIS X 0208 (1997) produced by Microsoft Word2000 (manufactured by Microsoft Corporation) filled with ink jet ink produced in an ink jet printer (manufactured by Ricoh Co., Ltd., IPSiO GX5000) in an environment of 23 ° C. and 50% RH. , 2223 is printed on plain paper (XEROX 4200, manufactured by XEROX), and the general symbol portion of JIS X 0208 (1997), 2223 on the recording surface is reflected by a reflective color spectrophotometric densitometer (apparatus). Name: X-Rite eXact, manufactured by X-Rite).
The recording mode used was a driver attached to the printer, in which the “plain paper-standard fast” mode was changed to “no color correction” from the user setting for plain paper. Moreover, 1.8 or more is an allowable range.

<Glossiness>
The prepared inkjet ink is filled into an inkjet printer (IPSiO GXe5500, manufactured by Ricoh Co., Ltd.), and a solid image is printed on a PET film (trade name: E5100, manufactured by Toyobo Co., Ltd.) at 25 ° C. For 1 hour. Next, using a gloss meter (BYK Gardener, 4501), the glossiness at an incident angle of 60 ° in the solid portion of the image was measured. The larger the value of the glossiness, the better the glossiness of the image. Note that the glossiness at 60 ° is within an allowable range of 30 or more.

As an aspect of this invention, it is as follows, for example.
<1> An inkjet ink comprising an organic solvent and polyethylene wax,
The polyethylene ink has an penetration of 1.2 or less as measured in accordance with JIS K2235.
<2> The inkjet ink according to <1>, wherein the polyethylene wax has a Martens hardness of 50 N / mm ² or more.
<3> The polyethylene wax has an endothermic peak and an exothermic peak in a range of 100 ° C. or higher and 130 ° C. or lower in differential scanning calorimetry,
The inkjet ink according to any one of <1> to <2>, wherein a peak area of the exothermic peak is 200 J / g or more and 300 J / g or less.
<4> In the differential scanning calorimetry, the polyethylene wax has an endothermic peak in a range from 119 ° C. to 129 ° C. and an exothermic peak in a range from 107 ° C. to 117 ° C.,
The ink-jet ink according to any one of <1> to <3>, wherein a peak area of the exothermic peak is 230 J / g or more and 270 J / g or less.
<5> In the differential scanning calorimetry, the polyethylene wax has an endothermic peak in a range from 107 ° C. to 117 ° C. and an exothermic peak in a range from 100 ° C. to 110 ° C.,
The ink-jet ink according to any one of <1> to <3>, wherein a peak area of the exothermic peak is 205 J / g or more and 245 J / g or less.
<6> The inkjet ink according to any one of <1> to <5>, wherein the polyethylene wax content is 0.05% by mass or more and 0.45% by mass or less.
<7> An inkjet ink containing an organic solvent,
The dynamic friction coefficient of a solid image ink film formed using the inkjet ink is 0.35 or less,
The solid matter of the inkjet ink has an endothermic peak and an exothermic peak in a range of 100 ° C. or higher and 130 ° C. or lower in differential scanning calorimetry,
The ink-jet ink is characterized in that a peak area of the exothermic peak is more than 0 J / g and 40 J / g or less.
<8> The inkjet image according to <7>, wherein the solid image is a solid image formed so that an adhesion amount of the inkjet ink is 1.12 g / cm ² .
<9> From the above <7> to <8, the solid matter of the inkjet ink has an endothermic peak in the range of 119 ° C. to 129 ° C. and an exothermic peak in the range of 107 ° C. to 117 ° C. in the differential scanning calorimetry. > The ink for ink jet recording according to any one of the above.
<10> From the above <7> to <8, the solid matter of the inkjet ink has an endothermic peak in a range of 107 ° C. or higher and 117 ° C. or lower and an exothermic peak in a range of 100 ° C. or higher and 110 ° C. or lower in differential scanning calorimetry. > The ink for ink jet recording according to any one of the above.
<11> The inkjet ink includes polyethylene wax,
The inkjet ink according to any one of <7> to <10>, wherein a penetration of the polyethylene wax measured in accordance with JIS K2235 is 1.2 or less.
<12> The inkjet ink according to <11>, wherein the polyethylene wax has a Martens hardness of 50 N / mm ² or more.
<13> The total Hansen solubility parameters of the organic solvent is an inkjet ink, wherein the solvent-containing is ^{20 MPa 1/2} or more ^{23 MPa 1/2} or less from the <7> to any one of <13>.
<14> The organic solvent is 3-butoxy-N, N-dimethylpropionamide, 3-methoxy-N, N-dimethylpropionamide, 3-ethyl-3-hydroxymethyloxetane, propylene glycol monopropyl ether, and propylene The inkjet ink according to any one of <7> to <13>, which is at least one selected from glycol monomethyl ether.
<15> The inkjet ink according to any one of <11> to <14>, wherein a content of the polyethylene wax is 0.05% by mass or more and 0.45% by mass or less.
<16> An ink container comprising the ink-jet ink according to any one of <1> to <15> contained in a container.
<17> An inkjet recording method comprising an ink application step of forming an image by applying the inkjet ink according to any one of <1> to <15> to a recording medium.
<18> An ink jet recording apparatus comprising ink applying means for applying the ink jet ink according to any one of <1> to <15> to a recording medium to form an image.
<19> A recorded matter having a recording medium and an ink film formed on the recording medium with ink,
The dynamic friction coefficient of the ink film is 0.35 or less,
The ink film has an endothermic peak and an exothermic peak in a range of 100 ° C. or higher and 130 ° C. or lower in differential scanning calorimetry,
The recorded product is characterized in that the peak area of the exothermic peak is more than 0 J / g and 40 J / g or less.
<20> The recorded matter according to <19>, wherein the ink film has an endothermic peak in a range of 119 ° C. to 129 ° C. and an exothermic peak in a range of 107 ° C. to 117 ° C. in differential scanning calorimetry. .
<21> The recorded matter according to <19>, wherein the ink film has an endothermic peak in a range of 107 ° C. to 117 ° C. and an exothermic peak in a range of 100 ° C. to 110 ° C. in differential scanning calorimetry. .
<22> The <19> to <21>, wherein the ink film includes a spectrum in which a mass spectrum detected by pyrolysis GC-MS measurement matches a mass spectrum of 1.2-propanediol. It is a record.

  The inkjet ink according to any one of <1> to <15>, the ink container according to <16>, the inkjet recording method according to <17>, and the inkjet recording apparatus according to <18>. According to the recorded matter described in any one of <19> to <22>, the above-described problems can be solved and the object of the present invention can be achieved.

JP 2012-246460 A JP 2010-090266 A JP 2014-162812 A JP 2013-064082 A

  400: Image forming apparatus (inkjet recording apparatus)

Claims (22)

An ink-jet ink comprising an organic solvent and polyethylene wax,
An inkjet ink, wherein the polyethylene wax has a penetration of 1.2 or less as measured in accordance with JIS K2235. The inkjet ink according to claim 1, wherein the polyethylene wax has a Martens hardness of 50 N / mm ² or more. The polyethylene wax has an endothermic peak and an exothermic peak in a range of 100 ° C. or higher and 130 ° C. or lower in differential scanning calorimetry,
The inkjet ink according to claim 1, wherein a peak area of the exothermic peak is 200 J / g or more and 300 J / g or less. In the differential scanning calorimetry, the polyethylene wax has an endothermic peak in a range from 119 ° C. to 129 ° C. and an exothermic peak in a range from 107 ° C. to 117 ° C.,
The inkjet ink according to any one of claims 1 to 3, wherein a peak area of the exothermic peak is 230 J / g or more and 270 J / g or less. In the differential scanning calorimetry, the polyethylene wax has an endothermic peak in a range of 107 ° C. or higher and 117 ° C. or lower and an exothermic peak in a range of 100 ° C. or higher and 110 ° C. or lower,
The inkjet ink according to any one of claims 1 to 3, wherein a peak area of the exothermic peak is 205 J / g or more and 245 J / g or less.   The inkjet ink according to any one of claims 1 to 5, wherein a content of the polyethylene wax is 0.05% by mass or more and 0.45% by mass or less. An inkjet ink containing an organic solvent,
The dynamic friction coefficient of a solid image ink film formed using the inkjet ink is 0.35 or less,
The solid matter of the inkjet ink has an endothermic peak and an exothermic peak in a range of 100 ° C. or higher and 130 ° C. or lower in differential scanning calorimetry,
An ink-jet ink, wherein a peak area of the exothermic peak is more than 0 J / g and 40 J / g or less. The inkjet ink according to claim 7, wherein the solid image is a solid image formed so that an adhesion amount of the inkjet ink is 1.12 g / cm ² .   9. The solid matter of the ink-jet ink has an endothermic peak in a range of 119 ° C. to 129 ° C. and an exothermic peak in a range of 107 ° C. to 117 ° C. in differential scanning calorimetry. Inkjet ink.   The solid matter of the ink-jet ink has an endothermic peak in a range of 107 ° C. or higher and 117 ° C. or lower and an exothermic peak in a range of 100 ° C. or higher and 110 ° C. or lower in differential scanning calorimetry. Inkjet ink. The inkjet ink includes polyethylene wax;
The inkjet ink according to any one of claims 7 to 10, wherein the polyethylene wax has a penetration of 1.2 or less as measured in accordance with JIS K2235. The inkjet ink according to claim 11, wherein the polyethylene wax has a Martens hardness of 50 N / mm ² or more. The total Hansen solubility parameter of the organic solvent is an inkjet ink according to any one of claims 7 containing a solvent is ^{20 MPa 1/2} or more ^{23 MPa 1/2} or less 12.   The organic solvent is 3-butoxy-N, N-dimethylpropionamide, 3-methoxy-N, N-dimethylpropionamide, 3-ethyl-3-hydroxymethyloxetane, propylene glycol monopropyl ether, and propylene glycol monomethyl ether The inkjet ink according to claim 7, wherein the inkjet ink is at least one selected from the group consisting of:   The inkjet ink according to any one of claims 11 to 14, wherein a content of the polyethylene wax is 0.05% by mass or more and 0.45% by mass or less.   An ink container comprising the ink jet ink according to claim 1 contained in a container.   An ink jet recording method comprising: an ink application step of applying an ink jet ink according to claim 1 to a recording medium to form an image.   An ink jet recording apparatus comprising ink applying means for applying an ink jet ink according to claim 1 to a recording medium to form an image. A recorded matter having a recording medium and an ink film formed of ink on the recording medium,
The dynamic friction coefficient of the ink film is 0.35 or less,
The ink film has an endothermic peak and an exothermic peak in a range of 100 ° C. or higher and 130 ° C. or lower in differential scanning calorimetry,
The recorded matter wherein the peak area of the exothermic peak is more than 0 J / g and 40 J / g or less.   The recorded matter according to claim 19, wherein the ink film has an endothermic peak in a range of 119 ° C. to 129 ° C. and an exothermic peak in a range of 107 ° C. to 117 ° C. in differential scanning calorimetry.   The recorded matter according to claim 19, wherein the ink film has an endothermic peak in a range of 107 ° C. to 117 ° C. and an exothermic peak in a range of 100 ° C. to 110 ° C. in differential scanning calorimetry.   The recorded matter according to any one of claims 19 to 21, wherein the ink film includes a spectrum in which a mass spectrum detected by pyrolysis GC-MS measurement matches a mass spectrum of 1.2-propanediol.