JP2017078158A - Ink, ink storage container and inkjet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink having high image density and excellent storage stability and discharge stability.SOLUTION: There is provided an ink which contains water, a pigment, an organic solvent and a surfactant, wherein the surfactant includes a silicone-based surfactant and a dialkyl sulfosuccinate ester salt, the organic solvent includes a glycol ether, and when the dynamic surface tension of the ink is measured at 23°C by a maximum bubble pressure method, the difference between the value of the dynamic surface tension at 15 msec and the value of the dynamic surface tension at 1500 msec is 4.0 mN/m or less and the value of the dynamic surface tension at 15 msec is 31 mN/m or less.SELECTED DRAWING: None

Description

  The present invention relates to ink, an ink container, and an ink jet recording apparatus.

The ink used for plain paper and various coated papers is required to have various qualities and functions, but various studies have been made to improve the image density, which is a basic quality.
In particular, there is a strong demand from the market for an improvement in image density of plain inkjet ink.

In general, it is said that the dynamic surface tension should be lowered to improve the image density.
Fluorine-based surfactants and silicone-based surfactants that tend to lower the surface tension lower the static surface tension when added in a small amount, but the dynamic surface tension is difficult to decrease. This is because the surfactant stabilizes by forming micelles in the ink, and it is difficult to contribute to a decrease in dynamic surface tension. In particular, it is difficult to reduce the dynamic surface tension with a fluorosurfactant.

Silicone surfactants can be easily reduced in dynamic surface tension by adjusting the molecular structure as compared with fluorosurfactants.
However, when a surfactant capable of lowering the dynamic surface tension is added, the static surface tension is too low and the meniscus formation in the nozzle becomes unstable, blurring or show-through on paper, etc. It tends to be bad.

On the other hand, acetylene glycol surfactants are known to have a relatively low dynamic surface tension and a small difference from static surface tension.
However, acetylene glycol surfactants exhibit good properties when used in dye-based inks, but when used in pigment-dispersed inks, they tend to destabilize pigment dispersion and cause aggregation, etc. Ejection defects such as nozzle bending are likely to occur. It is also known that wetting and spreading on coated paper or film is insufficient.

The ink described in Patent Document 1 uses an acetylene glycol surfactant and glycol ether together with a pigment dispersion to improve print quality on plain paper or recycled paper.
The ink described in Patent Document 2 seeks to improve storage stability by wrapping a pigment with a polymer to make an ink.

The ink described in Patent Document 3 uses a silicone having at least one acrylic group in the structure as a surfactant and also uses glycol ethers in combination with a highly hydrophobic hardly absorbing medium such as a polyvinyl chloride sheet. Therefore, it is intended to obtain a high print quality.
The ink described in Patent Document 4 is intended to obtain high print quality with respect to a hardly absorbent medium by a specific dynamic surface tension and an acetylene glycol surfactant.
The ink described in Patent Document 5 attempts to improve drying resistance and abrasion resistance by defining dynamic surface tension.

A first object of the present invention is to provide an ink with improved image density.
A second object of the present invention is to provide an ink having improved storage stability of a pigment dispersed in the ink.
A third object of the present invention is to provide an ink having improved ejection stability.

The present invention
In ink containing water, pigment, organic solvent and surfactant,
The surfactant includes a silicone-based surfactant and a sulfoalkyl succinate dialkyl ester salt, the organic solvent includes a glycol ether,
When the dynamic surface tension of the ink was measured at 23 ° C. by the maximum bubble pressure method, the difference between the dynamic surface tension value at 15 msec and the dynamic surface tension value at 1500 msec was 4.0 mN / m or less and 15 msec. An ink having a dynamic surface tension value of 31 mN / m or less,
It is related to.

  The ink of the present invention has little change in particle size and viscosity during storage and is excellent in ejection stability. When the ink of the present invention is used, an image having a high image density can be formed.

It is a figure which shows an example of the recording device using the ink of this invention. It is a perspective view of the main tank which accommodates the ink of this invention.

The present invention relates to the ink described in the following (1). Since the following (2) to (9) are included as embodiments of the invention, these embodiments will be described together.
(1) In an ink containing water, a pigment, an organic solvent, and a surfactant,
The surfactant includes a silicone-based surfactant and a sulfoalkyl succinate dialkyl ester salt, the organic solvent includes a glycol ether,
When the dynamic surface tension of the ink was measured at 23 ° C. by the maximum bubble pressure method, the difference between the dynamic surface tension value at 15 msec and the dynamic surface tension value at 1500 msec was 4.0 mN / m or less and 15 msec. The ink has a dynamic surface tension value of 31 mN / m or less.
(2) The ink according to (1), wherein the content of the glycol ether in the ink is 0.5% by mass or more and 4.0% by mass or less.
(3) The ink according to (1) or (2), wherein the glycol ether is diethylene glycol monohexyl ether.
(4) The ink further contains glycerin,
The ink according to any one of (1) to (3), wherein a content of the glycerin in the ink is 3.0% by mass or more and 10.0% by mass or less.
(5) The ink according to any one of (1) to (4), wherein the ink further contains a non-silicone antifoaming agent.
(6) When the total content (mass basis) of the silicone surfactant and the sulfoalkyl dialkyl ester salt in the ink is 1.0, the content (mass basis) of the glycol ether in the ink is The ink according to any one of (1) to (5) above, which is 1.0 or more and 3.0 or less.
(7) The content of the dialkyl ester salt of sulfosuccinic acid in the ink is from 0.1% by mass to 2.0% by mass, according to any one of (1) to (6), The ink described.
(8) An ink container comprising the ink described in any one of (1) to (7) in a container.
(9) the ink container described in (8) above;
Discharge means for discharging ink supplied from the ink container;
An ink jet recording apparatus comprising:

The ink of the present invention is an ink containing water, a pigment, an organic solvent and a surfactant. The surfactant contains a silicone-based surfactant and a dialkyl ester salt of sulfosuccinic acid, and the organic solvent contains a glycol ether.
The ink of the present invention can be used by being stored in an ink storage container such as an ink cartridge for storing ink. This ink container can be used by being detachably attached to various ink jet recording apparatuses.

In order to obtain a high image density, it is necessary that the smaller the contact angle in a short time immediately after the ink droplet comes into contact with the medium, the easier it is to spread and cover the surface of the medium. Therefore, it is better that the value of 15 msec of the dynamic surface tension is small.
For this reason, in the ink of this invention, the value of the dynamic surface tension in 15 msec measured by the maximum bubble pressure method at 23 degreeC shall be 31 mN / m or less.
If it is 31.0 mN / m or less, a sufficient concentration can be obtained. More preferably, it is 30.5 mN / m or less.

On the other hand, in order to suppress blurring and show-through, it is better that the value of the dynamic surface tension is 1500 msec. For this reason, it is better that the difference between the dynamic surface tension of 15 msec and the dynamic surface tension of 1500 msec is small.
Therefore, in the ink of the present invention, the difference between the dynamic surface tension value at 15 msec and the dynamic surface tension value at 1500 msec is set to 4.0 mN / m or less. More preferably, it is 3.5 mN / m or less.

In order to lower the dynamic surface tension, it is required that the added surfactant does not form micelles and is freely dissolved. For this purpose, glycol ether is added to the ink.
Glycol ether has an affinity for the lipophilic part of the surfactant, suppresses the formation of micelles of the surfactant in the aqueous solution, and promotes the arrangement of the surfactant on the droplet surface in a short time.
The content of glycol ether is preferably 0.5% by mass or more and 4.0% by mass. More preferably, it is 1.0 mass% or more and 3.0 mass% or less. When the content is 0.5% by mass or more, the dynamic surface tension is easily lowered, and when it is 4.0% by mass or less, quick drying is obtained.

Examples of glycol ethers include diethylene glycol monobutyl ether, tripropylene glycol monomethyl ether, and diethylene glycol monohexyl ether.
In particular, when the glycol ether is diethylene glycol monohexyl ether, the combination with the silicone surfactant makes it easy to reduce the value of the dynamic surface tension, and a high image density can be obtained.

The amount of change in the dynamic surface tension of the silicone-based surfactant is likely to increase, and if the value of 15 msec is lowered, the value of 1500 msec is also likely to be lowered.
For this reason, the ink of the present invention contains a sulfosuccinic acid dialkyl ester salt. By using the sulfosuccinic acid dialkyl ester salt in combination, the dynamic surface tension can be easily adjusted.
The content of the sulfosuccinic acid dialkyl ester salt in the ink is preferably 0.1% by mass or more and 2.0% by mass or less.

Furthermore, the ink of the present invention preferably contains 3.0% by mass or more and 10.0% by mass or less of glycerin.
By including 3.0 mass% or more and 10.0 mass% or less of glycerin, when applying to an inkjet system, excessive drying can be prevented. More preferably, it is 5.0 mass% or more and 8.0 mass% or less.

In the ink jet system, an image is formed by flying ink from a minute nozzle in the form of minute droplets. During the image formation, the nozzle is open to the air and moves at high speed on the surface of the paper while maintaining a minute interval. For this reason, the ink in the nozzle is placed in a state close to reduced-pressure drying, and is in a state where it is easy to dry.
Glycerin has a very high function as a humectant, and can prevent the ink from drying in the nozzle. Further, when used as the ink of the present invention, the effect of improving the dispersion stability of the pigment is exhibited. This is presumed to be due to a steric hindrance effect that prevents aggregation of the dispersed pigment.

  Further, the ink can maintain the foam suppression property by containing a non-silicone antifoaming agent. If an antifoaming agent having an HLB value of about 3 to 7 is selected, the effect is high. In the present invention, since the silicone-based surfactant has an effect of controlling the surface tension of the ink, it is preferable to use a non-silicone-based antifoaming agent in order not to inhibit the adjustment of the surface tension.

The ratio (mass basis) of the total content of the surfactants (silicone surfactant and sulfosuccinic acid dialkyl ester salt) and the glycol ethers is 1.0: 1.0 to 3.0. preferable.
By setting the content ratio as described above, the ink of the present invention maintains a stable surface tension, a high image density is obtained, and a high temporal stability is also obtained.
More preferably, it is 1.0: 1.5-2.5.

  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.

Moreover, you may use another surfactant together, if the effect of this invention is not prevented.
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.

As the silicone-based surfactant suitable for the present invention, those appropriately synthesized may be used, or commercially available products 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.
Specifically, 500W, 501W, 67additive manufactured by Toray Dow Corning Silicone Co., Ltd. and BYK-3400 manufactured by BYK Chemie Co., Ltd. can be preferably used.

<Ink>
Hereinafter, the organic solvent, water, color material, resin, additive, and the like used for the ink will be described.

<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- -N-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 because good drying properties can be obtained.

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.

  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.

<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.

<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 (eg, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, and quinofullerone pigments). 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 color material. 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.

<Resin>
The type of resin contained in the ink is not particularly limited and can be appropriately selected according to the purpose. For example, urethane resin, polyester resin, acrylic resin, vinyl acetate resin, styrene resin, butadiene type Examples thereof include resins, styrene-butadiene resins, vinyl chloride resins, acrylic styrene resins, and acrylic silicone resins.
Resin particles made of these resins may be used. An ink can be obtained by mixing resin particles with a material such as a colorant or an organic solvent in a resin emulsion state in which water is dispersed as a dispersion medium. 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, or may be used in combination of 2 or more types of resin particles.

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 resin content is not particularly limited and may be appropriately selected according to the purpose. However, from the viewpoint of fixability and ink storage stability, the content of the resin is 1% by mass or more and 30% by mass or less. Is preferable, and 5 mass% or more and 20 mass% or less are more preferable.

  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.).

<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.

  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.

<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.

<Recording medium>
The recording medium is not particularly limited, and plain paper, glossy paper, special paper, cloth, and the like can be used. Good image formation is possible even with a non-permeable substrate.
The non-permeable base material is a base material having a surface with low water permeability and absorbability, and includes materials that do not open to the outside even if there are many cavities inside, more quantitatively. In the Bristow method, the water absorption amount from the start of contact to 30 msec ^1/2 is 10 mL / m ² or less.
As said non-permeable base material, plastic films, such as a vinyl chloride resin film, a polyethylene terephthalate (PET) film, a polypropylene, polyethylene, a polycarbonate film, can be used conveniently, for example.

<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.

<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 application, a recording apparatus and a recording method are an apparatus that can eject ink, various processing liquids, and the like to a recording medium, and a method that performs 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 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. 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 of the present invention will be described below, but the present invention is not limited to these examples.

・イオン交換水・・・７５質量部
上記の混合物をプレミックスした後、ディスクタイプのビーズミル（シンマルエンタープライゼス社ＫＤＬ型、メディア：直径０．３ｍｍのジルコニアボール使用）で循環分散して顔料分散液（ａ）を得た。 [Examples 1-8, Comparative Examples 1-4]
<Preparation example of pigment dispersion>
Carbon black # 40 (manufactured by Mitsubishi Chemical) ... 15 parts by mass Compound represented by the following structural formula (polyoxyethylene (n = 40) β-naphthyl ether): 10 parts by mass

・ Ion-exchanged water: 75 parts by mass After premixing the above mixture, the mixture is circulated and dispersed in a disk-type bead mill (Shinmaru Enterprises KDL type, media: zirconia balls with a diameter of 0.3 mm) to disperse the pigment. A liquid (a) was obtained.

<Manufacture of ink>
According to the composition shown in Table 1, all the ingredients were put into a container equipped with a stirrer and stirred for 1 hour 30 minutes. Then, it filtered with the membrane filter with the hole diameter of 0.8 micrometer, and obtained the ink of Examples 1-8 and Comparative Examples 1-4.

Each component in Table 1 will be described below.
-BYK-3400 and BYK-3455 are silicone surfactants manufactured by BYK Japan.
BYK-3400 contains a sulfosuccinic acid dialkyl ester salt together with a silicone surfactant. Therefore, when BYK-3400 is added as an ink component, both the silicone surfactant and the sulfoalkyl succinate dialkyl ester salt are added to the ink.
W500, 67additive is a silicone surfactant manufactured by Toray Dow Corning.
Surfynol 465 is an acetylene glycol surfactant manufactured by Nissin Chemical.
291-PG is a non-silicone surfactant manufactured by Nippon Emulsifier Co., Ltd.
AD-01 is a non-silicone antifoaming agent manufactured by Nissin Chemical.
-KF-353 is a silicone-based antifoaming agent manufactured by Shin-Etsu Chemical Co., Ltd.

[Ink evaluation method]
<Image formation>
For the image formation, an ink jet printer IPSiO SG3100 manufactured by Ricoh Co., Ltd. was used.
<Dynamic surface tension>
For the measurement of the dynamic surface tension, DynaTester manufactured by SITA was used.
<Static surface tension>
For measurement of static surface tension, an automatic surface tension measuring machine DY-300 manufactured by Kyowa Interface Science Co., Ltd. was used.

<Average particle size>
The particle size (D50) of the ink was measured with a particle size distribution measuring device (Nikkiso Co., Ltd., Nanotrac UPA-EX150).

<Image density>
For the image density, a spectrocolorimetric densitometer model 938 manufactured by X-Rite was used.
Using the inkjet printer, a document in which six 10 mm square black solid patches were evenly arranged was punched out on My Paper (manufactured by NBS Ricoh Co., Ltd.), and the image density of the black solid portion was measured.
The print mode is “plain paper fast” in the driver settings.

<Viscosity>
Measurement is performed using a rheometer (MCR301 manufactured by Anton Paar) in an environment of 25 ° C. and 50% RH. At this time, a gap (Gap) is set to 50 μm using a flat plate having a diameter of 5 (cm). The viscosity at a shear rate of 100 (1 / s) was measured.

<Discharge stability>
Using the inkjet printer, changing the driving voltage of the piezo element so that the amount of ink discharged is uniform, and one chart that fills 5% area of A4 size paper per color created with Microsoft Word 2000 with a solid image , My paper (manufactured by NBS Ricoh Co., Ltd.) was confirmed to confirm that there was no discharge disturbance.
Thereafter, the maintenance cap of the printer was separated from the nozzles to open the nozzles, and then left in an environment of 40 ° C. and 10% RH for 3 hours.
Thereafter, the same chart as that in the initial stage was printed, and ejection disturbance of each nozzle was evaluated according to the following criteria. The print mode used was a driver attached to the printer, in which the “plain paper standard faster” mode was changed to “no color correction” than the user setting for plain paper.
〔Evaluation criteria〕
○: All nozzles are ejected. Δ: Less than 10 nozzles that do not eject. X: 10 or more nozzles that do not eject.

  As shown in Table 2, the ink of the present invention exhibits high image density, has little change in particle size and viscosity during storage, and is excellent in ejection stability.

400 Image forming apparatus 401 Exterior 401c Cover 404 Cartridge holder 410, 410k, 410c, 410m, 410y Main tank 411 Ink storage section 413 Ink discharge port 414 Storage container case 420 Mechanism section 436 Supply tube 434 Discharge head

JP 2004-339282 A JP 2004-143387 A JP 2013-189599 A Special table 2015-515510 gazette Japanese Patent Laying-Open No. 2015-044405

Claims (9)

In ink containing water, pigment, organic solvent and surfactant,
The surfactant includes a silicone-based surfactant and a sulfoalkyl succinate dialkyl ester salt, the organic solvent includes a glycol ether,
When the dynamic surface tension of the ink was measured at 23 ° C. by the maximum bubble pressure method, the difference between the dynamic surface tension value at 15 msec and the dynamic surface tension value at 1500 msec was 4.0 mN / m or less and 15 msec. The ink has a dynamic surface tension value of 31 mN / m or less.   2. The ink according to claim 1, wherein the content of the glycol ether in the ink is 0.5% by mass or more and 4.0% by mass or less.   The ink according to claim 1 or 2, wherein the glycol ether is diethylene glycol monohexyl ether. The ink further contains glycerin,
The ink according to any one of claims 1 to 3, wherein a content of the glycerin in the ink is 3.0% by mass or more and 10.0% by mass or less.   The ink according to any one of claims 1 to 4, wherein the ink further contains a non-silicone antifoaming agent.   When the total content (mass basis) of the silicone surfactant and the dialkyl ester salt of sulfosuccinic acid salt in the ink is 1.0, the content (mass basis) of the glycol ether in the ink is 1.0. The ink according to any one of claims 1 to 5, wherein the ink is 3.0 or more and 3.0 or less.   The ink according to claim 1, wherein a content of the sulfosuccinic acid dialkyl ester salt in the ink is 0.1% by mass or more and 2.0% by mass or less.   An ink storage container comprising the ink according to any one of claims 1 to 7 in a container. An ink container according to claim 8,
Discharge means for discharging ink supplied from the ink container;
An ink jet recording apparatus comprising:

Images