JP6753065B2 - Ink, recording material, ink cartridge, recording device and recording method - Google Patents

Description

The present invention relates to inks, recording materials, ink cartridges, recording devices and recording methods.

The inkjet recording method is a recording method in which ink droplets are directly ejected from a very fine nozzle onto a recording member and adhered to obtain characters or images. According to this method, not only the noise of the device to be used is small and the operability is good, but also the colorization is easy and plain paper can be used as a recording member. It is widely used as an output device in offices and homes.

On the other hand, even in industrial applications, it is expected that it will be used as an output machine for digital printing due to the improvement of inkjet technology, and printing machines capable of printing on non-absorbent equipment using solvent ink or UV ink are actually on the market. I came. However, in recent years, the demand for water-based inks has been increasing from the viewpoint of environmental friendliness.

As a water-based ink for inkjet, the development of an ink whose printing target is a special paper such as plain paper or photographic glossy paper has been made for a long time. On the other hand, in recent years, the use of the inkjet recording method is expected to expand, and the need for printing on coated paper such as coated paper is increasing. However, pigments are firmly fixed to media with low permeability such as coated paper. It's difficult to get it done. As in Patent Document 1, there is a means of coating the post-treatment liquid to protect the ink layer and secure the fixability, but since the printing apparatus becomes large and the cost increases, an image having good fixability can be obtained without a post-treatment step. It is required to obtain.

Further, the fixability can be improved by adding a resin as in Patent Document 2. As the type of resin to be used, it is said that an acrylic resin is preferable from the viewpoint of resistance of printed matter, but sufficient fixability has not been obtained only with the acrylic resin. This is thought to be due to the properties of acrylic, which becomes hard and brittle when cured.

Therefore, a method has been adopted in which a urethane-based resin having high elasticity is added to compensate for the brittleness of acrylic to improve fixability (Patent Document 3). A description that excellent scratch resistance, light resistance, and storage stability can be obtained by adding acrylic resin and urethane resin, and that the gloss is improved by adding urethane resin rather than acrylic resin alone depending on the conditions. There is.

However, it is known that acrylic resins tend to exhibit high gloss due to their property of becoming harder than urethane resins when they are formed into a film, and that the gloss tends to decrease when urethane resins are added. Therefore, as in Patent Document 4, when urethane-based resin is used, wax is also used in combination to ensure gloss. However, when wax is used, there is a problem that the wax is easily deposited on the surface of the printed matter and the appearance is easily deteriorated.

Therefore, an object of the present invention is to provide an ink having excellent fixability and high gloss.

In order to solve the above problems, the present invention is an ink containing water, an organic solvent and a coloring material, and the ink contains urethane-based resin particles and acrylic resin particles, and is contained in the organic solvent. The difference between the total HSP value of the organic solvent having the highest boiling point and the total HSP value of the urethane-based resin particles is 6.0 [(J / cm ³ ) ^0.5 ] or less, and among the organic solvents. The difference between the polar HSP value of the organic solvent having the highest boiling point and the polar HSP value of the urethane-based resin particles is 5.0 [(J / cm ³ ) ^0.5 ] or less.

According to the present invention, it is possible to provide an ink having excellent fixability and high gloss.

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

Hereinafter, the ink, recorded matter, ink cartridge, recording device, and recording method according to the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments shown below, and can be modified within the range conceivable by those skilled in the art, such as other embodiments, additions, modifications, and deletions. However, as long as the action and effect of the present invention are exhibited, it is included in the scope of the present invention.

The present invention is an ink containing water, an organic solvent and a coloring material, and the ink contains urethane-based resin particles and acrylic-based resin particles, and is a total of organic solvents having the highest boiling point among the organic solvents. The difference between the HSP value and the total HSP value of the urethane-based resin particles is 6.0 [(J / cm ³ ) ^0.5 ] or less, and the organic solvent having the highest boiling point among the organic solvents The difference between the polar HSP value and the polar HSP value of the urethane-based resin particles is 5.0 [(J / cm ³ ) ^0.5 ] or less.

The present invention is an ink containing water, an organic solvent and a coloring material. The ink contains urethane-based resin particles and acrylic-based resin particles, and the ink is applied onto a support containing cellulose pulp. When a work layer is formed and a solid image is formed on a recording medium having a surface roughness of 7.0 [μm] or more and 10.0 [μm] or less with an adhesion amount of 500 to 700 mg / A4, the surface roughness is formed. It is characterized in that Ra is 6.0 [μm] or more and 7.5 [μm] or less.

According to the study by the present inventors, when the glossiness with respect to the surface roughness Ra when the acrylic resin particles were used and when the urethane resin particles were used was measured, the acrylic resin particles were measured even when the surface roughness was the same. When the urethane-based resin particles are used at the same time as the acrylic-based resin particles, the leveling property is further improved and the surface roughness when an image is formed on the recording medium is reduced. I found it necessary.

Specifically, the surface roughness Ra is preferably 6.0 [μm] or more and 7.5 [μm] or less, more preferably 6.3 [μm] or more, and particularly preferably 6.5 [μm] or more. The reason is that if Ra is larger than 7.5 [μm], glossiness higher than that of coated paper is not obtained and is not sufficient, and if Ra is less than 6.0 [μm], when printed matter is overlapped. Since the gaps between the printed materials are reduced and the adhesion is increased, the blocking property is deteriorated.

However, this surface roughness Ra could not be achieved only by mixing the urethane resin particles with the acrylic resin particles. The reason is not clear, but it is considered that the acrylic resin particles and the urethane resin particles have different solubilitys and therefore have different leveling properties. Therefore, the present invention has been achieved by diligently studying the following matters, and it has become possible to achieve both gloss and fixability.

In the present invention, the surface roughness Ra is measured by the method specified in JISB-0601, and the measurement is performed using LEXT OLS4100 (manufactured by Olympus Corporation). The measurement length is 2.5 mm and the cutoff value is 0.8 mm.

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

<Organic solvent>
As a result of studies by the present inventors, it has been found that it is important to specify the HSP values of the organic solvent, urethane-based resin particles, and acrylic resin particles in order to satisfy the above physical properties.
The organic solvent used in the present invention differs depending on the resin type used, but the difference between the total HSP value of the organic solvent and the total HSP value of the urethane-based resin particles is 6.0 [(J / cm ³ ) ^0.5 ]. It is important that the difference between the polar HSP value of the organic solvent and the polar HSP value of the urethane-based resin particles is 5.0 [(J / cm ³ ) ^0.5 ] or less.

When a plurality of kinds of organic solvents are used, the difference between the HSP value of the solvent having the highest boiling point and the last evaporation and the HSP value of the urethane resin particles is taken. That is, the difference between the total HSP value of the organic solvent having the highest boiling point among the organic solvents and the total HSP value of the urethane-based resin particles is 6.0 [(J / cm ³ ) ^1/2 ] or less, and The difference between the polar HSP value of the organic solvent having the highest boiling point among the organic solvents and the polar HSP value of the urethane resin particles is 5.0 [(J / cm ³ ) ^1/2 ] or less. The difference represents the absolute value when the difference is taken.

When the difference between the HSP values of the organic solvent and the urethane resin particles is out of the above range, sufficient leveling property cannot be obtained, and when a solid image is formed on the above-mentioned predetermined recording medium with a predetermined amount of adhesion, the surface roughness is roughened. Ra is 7.5 [μm] or more, and sufficient gloss cannot be obtained. When the difference between the HSP values of the organic solvent and the urethane resin particles is within the above range, the surface roughness Ra is 6.0 [when an image is formed with a predetermined adhesion amount to the above-mentioned predetermined recording medium. It can be greater than or equal to μm and less than or equal to 7.5 [μm].

Further, the difference between the total HSP value of the organic solvent having the highest boiling point among the organic solvents and the total HSP value of the acrylic resin particles is 5.0 [(J / cm ³ ) ^0.5 ] or less. preferable. If it is within the above range, the leveling property is improved and the surface roughness is reduced, so that good gloss can be obtained.

The HSP value indicates the solubility parameter of Hansen and is an index showing the solubility of the substance. This HSP value is different from the Hildebrand SP value used in the Solvent Handbook (published by Kodansha Scientific Co., Ltd.), and its solubility is multidimensional (typically 3D). It is represented by a vector. This vector can be typically represented by a dispersion term, a polarity term, and a hydrogen bond term. This dispersion term is a van der Waals force, the polarity term is a dipole moment, and the hydrogen bond term is an action of water, alcohol, etc. Reflects. The total HSP value is the sum of the above three vectors. The HSP value can be calculated by software such as HSPiP. And it can be judged that those having similar vectors by HSP have high solubility. Therefore, if the boiling point is high among the contained organic solvents and the HSP values of the organic solvent and the resin particles that remain until the end during drying and fixing of the ink are close, the compatibility is good and the familiarity is good, so that the image surface at the time of film formation It is considered that the leveling property is improved. Even if the ink contains an organic solvent having an HSP value close to the HSP value of the urethane resin particles, the effect of the present invention can be obtained if the organic solvent does not have the highest boiling point among the organic solvents. I couldn't.

Further, as long as the difference between the HSP value of the organic solvent having the highest boiling point among the organic solvents and the HSP value of the urethane resin particles is within the above range, the organic solvent is not particularly limited and can be changed as appropriate. Yes, a water-soluble organic solvent can also be used. For example, polyhydric alcohols, ethers such as polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, sulfur-containing compounds and the like can be mentioned.

Specific examples of the water-soluble organic solvent include ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, and 1,4-butane. Diol, 2,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol , 2,4-Pentanediol, 1,5-Pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, 1,5-hexanediol, Glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-hexanediol, ethyl-1,2,4-butanetriol, 1,2,3-butanetriol, 2,2,4-trimethyl- Polyhydric alcohols such as 1,3-pentanediol and petriol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl Polyhydric alcohol alkyl ethers such as ether, polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone. , 1,3-Dimethyl-2-imidazolidinone, ε-caprolactam, γ-butyrolactone and other nitrogen-containing heterocyclic compounds, formamide, N-methylformamide, N, N-dimethylformamide, 3-methoxy-N, N- Amidos such as dimethylpropionamide, 3-butoxy-N, N-dimethylpropionamide, amines such as monoethanolamine, diethanolamine and triethylamine, sulfur-containing compounds such as dimethylsulfoxide, sulfolane and thiodiethanol, propylene carbonate and ethylene carbonate. And so on.

Among the above, the amide compound or the oxetane compound is particularly preferable as the solvent having the highest boiling point. By using these compounds, the film strength can be improved, and since the value is close to the HSP value of the resin particles, the dispersion stability and leveling property are excellent. Examples of the amide compound or oxetane compound include N, N-dimethyl-β-butoxypropionamide (HSP value: 20.2), N, N-dimethyl-β-methoxypropionamide (HSP value: 22.5), 3-. Ethyl-3-hydroxymethyloxetane (HSP value: 22.6), propylene glycol monomethyl ether (1-methoxy-2-propanol) (HSP value: 20.4) and the like are preferable. The total HSP value is preferably an organic solvent of 20 or more and 23 or less.

The boiling point of the organic solvent is preferably 180 ° C. or higher and 250 ° C. or lower. If the boiling point is less than 180 ° C., the evaporation rate at the time of drying becomes high, the leveling is not sufficiently performed, the surface unevenness becomes large, and the gloss may decrease. On the contrary, if the temperature is higher than 250 ° C., the drying property is low, and long-term drying may be required. With the speeding up of printing technology in recent years, the time required for drying the ink has become rate-determining, and it is necessary to shorten the drying time.

The content of the organic solvent 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 60% by mass or less from the viewpoint of ink drying property and ejection reliability. More preferably, it is 20% by mass or more and 60% by mass or less.

When the organic solvent contains two or more kinds of organic solvents, the organic solvent having the lowest total HSP value is used as the solvent A, and the organic solvent having the next lowest total HSP value is used as the solvent. When B is set, it is preferable that the HSP value distance obtained by the following formula satisfies a predetermined value. That is, it is preferable that the HSP value distance between the solvent A and the solvent B is 9 or less, and the HSP value distance between the water contained in the ink and the solvent B is 32 or less.

The notation in the formula is as follows.
Ra: HSP value distance δ _D2 : Non-polar HSP value of solvent B (dispersed HSP value)
δ _D1 : Non-polar HSP value (dispersed HSP value) of solvent A (or water)
δ _P2 : Polarity HSP value of solvent B δ _P1 : Polarity HSP value of solvent A (or water) δ _H2 : Hydrogen bond HSP value of solvent B δ _H1 : Hydrogen bond HSP value of solvent A (or water)

When the hydrophobic solvent is separated in the ink solvent, the resin is exposed to the hydrophobic solvent and aggregates, which may cause nozzle clogging. By using a solvent in the above range, the hydrophobic solvent is difficult to separate in the nozzle hole, and an ink without nozzle clogging can be obtained.

When the above total HSP value is expressed by an equation, it can be expressed as follows.

The notation in the formula is as follows.
δ _D : Non-polar HSP value (dispersion HSP value)
δ _P : Polar HSP value δ _H : Hydrogen bond HSP value

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

<Color material>
The coloring material is not particularly limited, and pigments and dyes can be used.
As the pigment, an inorganic pigment or an organic pigment can be used. These may be used alone or in combination of two or more. Moreover, you may use a mixed crystal.
As the pigment, for example, black pigment, yellow pigment, magenta pigment, cyan pigment, white pigment, green pigment, orange pigment, glossy color pigment such as gold or silver, metallic pigment and the like can be used.
As inorganic pigments, carbon black produced by known methods such as contact method, furnace method, thermal method, in addition to titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, and chrome yellow. Can be used.
Examples of organic pigments include azo pigments and polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, quinofuralone pigments, etc.). , Dye chelate (for example, basic dye type chelate, acidic dye type chelate, etc.), nitro pigment, nitroso pigment, aniline black and the like can be used. Among these pigments, those having a good affinity with a solvent are preferably used. In addition, resin hollow particles and inorganic hollow particles can also be used.
As a specific example of the pigment, for black, carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, or copper, iron (CI pigment black 11) , Metals such as titanium oxide, and organic pigments such as aniline black (CI pigment black 1).
Further, for color, C.I. I. Pigment Yellow 1,3,12,13,14,17,24,34,35,37,42 (yellow iron oxide), 53,55,74,81,83,95,97,98,100,101,104 , 108, 109, 110, 117, 120, 138, 150, 153, 155, 180, 185, 213, C.I. I. Pigment Orange 5, 13, 16, 17, 36, 43, 51, C.I. I. Pigment Red 1, 2, 3, 5, 17, 22, 23, 31, 38, 48: 2, 48: 2 (Permanent Red 2B (Ca)), 48: 3, 48: 4, 49: 1, 52: 2, 53: 1, 57: 1 (Brilliant Carmin 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81, 83, 88, 101 (Mengara), 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 Greens 1, 4, 7, 8, 10, 17, 18, 36, etc.
The dye is not particularly limited, and acid dyes, direct dyes, reactive dyes, and basic dyes can be used, and one type may be used alone or two or more types may be used in combination.
As the dye, for example, C.I. I. Acid Yellow 17, 23, 42, 44, 79, 142, C.I. I. Acid Red 52,80,82,249,254,289, C.I. I. Acid Blue 9,45,249, C.I. I. Acid Black 1,2,24,94, C.I. I. 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. Dilekdo Black 19, 38, 51, 71, 154, 168, 171, 195, C.I. I. Reactive Red 14, 32, 55, 79, 249, C.I. I. Reactive Black 3, 4, 35 can be mentioned.

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

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

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

<Resin particles>
The resin used in the present invention is urethane-based resin particles and acrylic-based resin particles. It is possible to obtain ink by mixing resin particles with a material such as a coloring material or an organic solvent in the state of a resin emulsion in which water is dispersed as a dispersion medium. As the resin particles, those synthesized as appropriate may be used, or commercially available products may be used. As the urethane resin, Eucoat manufactured by Daiichi Kogyo Seiyaku Co., Ltd .: Takelac manufactured by Mitsui Chemicals Co., Ltd. and the like can be used. As the acrylic resin, for example, Toagosei Corporation: Cymac, DIC Corporation: Boncoat, Daicel Chemical Industry Co., Ltd .: Aquabrid, Showa High Polymer Co., Ltd .: Polysol, and the like can be used. Further, as the urethane resin, a polycarbonate-based urethane resin is preferable from the viewpoint of storage stability and fixability. As the polycarbonate-based urethane resin, for example, Takelac WS-4000, W-6010, W-6110 manufactured by Mitsui Chemicals, Inc. are commercially available.

It is preferable that the content of the acrylic resin particles in the ink is higher than the content of the urethane resin particles in the ink. If the ratio of the urethane-based resin is large, the tackiness of the image surface becomes large, and the blocking property may deteriorate. More specifically, the ratio of the urethane-based resin particles to the acrylic-based resin particles is preferably 0.1 to 0.7 in terms of the mass ratio of the solid content. Within this range, both scratch resistance, ejection stability, and ink storage stability can be achieved at the same time.

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

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

The content of the urethane-based resin fine particles is preferably 0.5% by mass or more and 2.0% by mass or less with respect to the total amount of ink, and the content of the acrylic resin fine particles is relative to the total amount of ink. It is preferably 0.5% by mass or more and 2.0% by mass or less.

Further, the glass transition temperature Tg of the urethane-based resin fine particles is preferably −20 [° C.] or more and 70 [° C.] or less. Within this range, the film forming property is good, and good blocking property is exhibited even in a short drying time. Further, a more preferable range is −20 [° C.] or more and 25 [° C.] or less.

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

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

<Surfactant>
As the surfactant, any of a silicone-based surfactant, a fluorine-based surfactant, an amphoteric surfactant, a nonionic surfactant, and an anionic surfactant can be used.
The silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. Among them, those that do not decompose even at high pH are preferable, and examples thereof include side chain modified polydimethylsiloxane, double-ended modified polydimethylsiloxane, one-ended modified polydimethylsiloxane, and side chain double-ended modified polydimethylsiloxane. Those having an oxyethylene group and a polyoxyethylene polyoxypropylene group are particularly preferable because they exhibit good properties as an aqueous surfactant. Further, as the silicone-based surfactant, a polyether-modified silicone-based surfactant can also be used, and examples thereof include a compound in which a polyalkylene oxide structure is introduced into the Si portion side chain of dimethylsiloxane.
The fluorine-based surfactant has, for example, 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. A polyoxyalkylene ether polymer compound is particularly preferable because it has a low foaming property. Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid and perfluoroalkyl sulfonic acid salt. Examples of the perfluoroalkylcarboxylic acid compound include perfluoroalkylcarboxylic acid and perfluoroalkylcarboxylic acid salt. The polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain includes a sulfate ester salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain and a perfluoroalkyl ether group in the side chain. Examples thereof include salts of polyoxyalkylene ether polymers. The counterions of the salts in these fluorine-based surfactants are 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. can be mentioned.
Examples of the amphoteric surfactant include laurylaminopropionate, lauryldimethylbetaine, stearyldimethylbetaine, and lauryldihydroxyethylbetaine.
Examples of the nonionic surfactant include polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkyl amine, polyoxyethylene alkyl amide, polyoxyethylene propylene block polymer, sorbitan fatty acid ester, and polyoxyethylene sorbitan. Examples thereof include a fatty acid ester and an ethylene oxide adduct of acetylene alcohol.
Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, lauryl salt, polyoxyethylene alkyl ether sulfate salt and the like.
These may be used alone or in combination of two or more.

The silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, side chain-modified polydimethylsiloxane, double-ended modified polydimethylsiloxane, one-ended modified polydimethylsiloxane, side. Examples thereof include polydimethylsiloxane modified at both ends of the chain, and a polyether-modified silicone-based surfactant having a polyoxyethylene group and a polyoxyethylene polyoxypropylene group as modifying groups exhibits good properties as an aqueous surfactant, and is particularly effective. preferable.
As such a surfactant, an appropriately synthesized one may be used, or a commercially available product may be used. As commercially available products, for example, they can be obtained from Big Chemie Co., Ltd., Shin-Etsu Chemical Co., Ltd., Toray Dow Corning Silicone Co., Ltd., Nippon Emulsion Co., Ltd., Kyoeisha Chemical Co., Ltd., and the like.
The above-mentioned polyether-modified silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the polyalkylene oxide structure represented by the general formula (S-1) is dimethylpoly. Examples thereof include those introduced into the Si part side chain of siloxane.

(However, in the general formula (S-1), m, n, a, and b represent integers. R and R'represent an alkyl group and an alkylene group.)
Commercially available products can be used as the above-mentioned polyether-modified silicone-based surfactant, for example, KF-618, KF-642, KF-643 (Shinetsu Chemical Industry Co., Ltd.), EMALEX-SS-5602, SS- 1906EX (Nippon 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 (Big Chemie Co., Ltd.), TSF4440, TSF4452, TSF4453 (Toshiba Silicon Co., Ltd.) and the like can be mentioned.

As the fluorine-based surfactant, a compound having 2 to 16 carbon atoms substituted with fluorine is preferable, and a compound having 4 to 16 carbon atoms substituted with fluorine is more preferable.
Examples of the fluorine-based surfactant include a perfluoroalkyl phosphate compound, a perfluoroalkylethylene oxide adduct, and a polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain. Among these, polyoxyalkylene ether polymer compounds having a perfluoroalkyl ether group in the side chain are preferable because they have low foaming property, and are particularly fluorine-based compounds represented by the general formulas (F-1) and (F-2). Surfactants are preferred.

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.
C _n F _{2n + 1-} CH ₂ CH (OH) CH _2- O- (CH ₂ CH ₂ O) _a- Y ... General formula (F-2)
In the compound represented by the above general formula (F-2), Y is H or CnF _{2n + 1} and n is an integer of 1 to 6, or CH ₂ CH (OH) CH _2- CnF _{2n + 1} and n is 4 to 6. It is an integer, or CpH _{2p + 1} and p is an integer of 1-19. a is an integer of 4 to 14.
Commercially available products may be used as the above-mentioned fluorine-based surfactant. Examples of this commercially available product include Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, and S-145 (all manufactured by Asahi Glass Co., Ltd.); Full Lard FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M Co., Ltd.); Megafuck F-470, F -1405, F-474 (all manufactured by Dainippon Ink and Chemicals Co., Ltd.); Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR (all) , DuPont); FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW (all manufactured by Neos Co., Ltd.), Polyfox PF-136A, PF-156A, PF-151N, PF-154, PF-159 (manufactured by Omniova), Unidyne DSN-403N (manufactured by Daikin Industries, Ltd.), etc. Among these, good print quality, especially color development and permeability to paper. FS-300 manufactured by DuPont, FT-110, FT-250, FT-251, FT-400S, FT-150, FT- of Neos Co., Ltd. from the viewpoint of remarkably improving wettability and leveling property. 400SW, Polyfox PF-151N manufactured by Omniova Co., Ltd. and Unidyne DSN-403N manufactured by Daikin Industries, Ltd. are particularly preferable.

The content of the surfactant in the ink is not particularly limited and may be appropriately selected depending on the intended purpose. However, 0.001 mass is obtained from the viewpoint of excellent wettability and ejection stability and improvement in image quality. % Or more and 5% by mass or less are preferable, and 0.05% by mass or more and 5% by mass or less are more preferable.

<Antifoam>
The defoaming agent is not particularly limited, and examples thereof include a silicone-based defoaming agent, a polyether-based defoaming agent, and a fatty acid ester-based defoaming agent. These may be used alone or in combination of two or more. Among these, a silicone-based defoaming agent is preferable because it has an excellent defoaming effect.

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

<Rust inhibitor>
The rust preventive is not particularly limited, and examples thereof include acidic sulfite and sodium thiosulfate.

<pH adjuster>
The pH adjusting agent 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.

The physical properties of the ink are not particularly limited and may be appropriately selected depending on the intended purpose. For example, the viscosity, surface tension, pH and the like are preferably in the following ranges.
The viscosity of the ink at 25 ° C. 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 print density and character quality and obtaining good ejection properties. More preferred. Here, for the viscosity, for example, a rotary viscometer (RE-80L manufactured by Toki Sangyo Co., Ltd.) can be used. As the measurement conditions, it is possible to measure at 25 ° C. with a standard cone rotor (1 ° 34'x R24), a sample liquid volume of 1.2 mL, a rotation speed of 50 rpm, and 3 minutes.
The surface tension of the ink is preferably 35 mN / m or less, more preferably 32 mN / m or less at 25 ° C. from the viewpoint that the ink is preferably 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.
When the ink of the present invention is used, even a highly glossy paper in which a coating layer is formed on a support containing cellulose pulp can obtain higher gloss and is effective. Specifically, printing paper Lumi Art Gloss 130 gsm (manufactured by Stora Enso, 60 ° gloss: 26.5) is preferable. The surface roughness of the printing paper is 7.0 [μm] or more and 10 [μm] or less, and when a solid image is formed on this recording medium with an adhesion amount of 500 to 700 mg / A4, the surface roughness Ra is 6. When it is 0 [μm] or more and 7.5 [μm] or less, an image having good gloss and fixability can be obtained.

At this time, as a printing method, a recording ink is filled in an inkjet printer IPSIO GX5500 (manufactured by Ricoh), Lumi Art Gloss 130 gsm paper (manufactured by Stora Enso) is set therein, and solid printing is performed at a resolution of 1200 dpi. After drying at 100 ° C. for 1 minute, the mixture was left at room temperature for 24 hours. The surface roughness of the recording medium and the image was measured by using LEXT OLS4100 (manufactured by Olympus Corporation), the measurement length was 2.5 mm, and the cutoff value was 0.8 mm.

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

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

The method of using the ink is not limited to the inkjet recording method, and can be widely used. In addition to the inkjet recording method, examples thereof include 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, and a spray coating method.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following Examples.

<Pigment dispersion PD-C>
A self-dispersing pigment dispersion was prepared in the same manner as in the method described in-Method A- of [Pigment surface modification treatment] of JP2012-207202. 20 g of Pigment Blue 15: 3 (Chromofine Blue manufactured by Dainichiseika Co., Ltd.), 20 mmol of the compound of the following structural formula (1), and 200 mL of ion-exchanged high pure water are mixed with a Silverson mixer (6,000 rpm) in a room temperature environment. .. If the pH of the resulting slurry is higher than 4, 20 mmol nitric acid is added. After 30 minutes, sodium nitrite (20 mmol) dissolved in a small amount of ion-exchanged hyperpure water is slowly added to the mixture. Further, the mixture is heated to 60 ° C. with stirring and reacted for 1 hour. A modified pigment can be produced by adding the compound of the following structural formula (1) to Pigment Blue. Then, the pH is adjusted to 10 with an aqueous NaOH solution to obtain a modified pigment dispersion after 30 minutes. Ultrafiltration using a diafiltration membrane using a dispersion containing a pigment bonded to at least one geminal bisphosphonic acid group or a sodium geminal bisphosphonic acid salt and ion-exchanged high pure water, and further performing ultrasonic dispersion to carry out the pigment. A cyan pigment dispersion [PD-C] having a concentration of 15% was obtained.

<Pigment dispersion PD-M>
In the method for producing the pigment dispersion [PD-C], the same as the method for producing [PD-C], except that 20 g of Pigment Blue was changed to 20 g of Pigment Red 122 (Toner Magenta EO02 manufactured by Clariant). A magenta pigment dispersion [PD-M] having a pigment concentration of 15% was obtained.

<Pigment dispersion PD-Y>
The method for producing the pigment dispersion [PD-M] is the same as the method for producing [PD-M], except that 20 g of Pigment Blue is changed to 20 g of Pigment Yellow 74 (Fast Yellow 531 manufactured by Dainichiseika Co., Ltd.). A yellow pigment dispersion [PD-Y] having a pigment concentration of 15% was obtained.

<Other materials>
Hereinafter, the acrylic resins Ac-1 to 2 and the urethane resins Ur-1 to 5 used in Examples and Comparative Examples are shown.
<Resin Ac-1>
・ Acrylic silicone resin Cymac US480 (manufactured by Toagosei Co., Ltd.)
<Resin Ac-2>
・ Styrene acrylic resin Polysol AP-1120 (manufactured by Showa High Polymer Co., Ltd.)
<Resin Ur-1>
-Polycarbonate resin Takelac W6110 (manufactured by Mitsui Chemicals, Inc.)
<Resin Ur-2>
-Polycarbonate resin Takelac W6061 (manufactured by Mitsui Chemicals, Inc.)
<Resin Ur-3>
-Polyether resin Takelac W5661 (manufactured by Mitsui Chemicals, Inc.)
<Resin Ur-4>
-Polycarbonate resin Takelac W6010 (manufactured by Mitsui Chemicals, Inc.)
<Resin Ur-5>
・ Ester / ether urethane resin Superflex 300 (manufactured by Dai-ichi Kogyo Seiyaku)

Hereinafter, the organic solvents Os-1 to 8 used in Examples and Comparative Examples are shown.
<Organic solvent Os-1>
N, N-dimethyl-β-butoxypropionamide (B100; manufactured by Idemitsu Kosan Co., Ltd.) represented by the following structural formula (2) Total HSP value: 20.2, polar HSP value: 8.9, boiling point 252 ° C.

<Organic solvent Os-2>
3-Ethyl-3-hydroxymethyloxetane (EHO; manufactured by Ube Industries, Ltd.) represented by the following structural formula (3) Total HSP value: 22.6, polar HSP value: 7.9, boiling point 227 ° C.

<Organic solvent Os-3>
-1,2-Butanediol (manufactured by Shinko Organic Chemical Industry Co., Ltd.) Total HSP value: 26.9, polar HSP value: 8.2, boiling point 195 ° C.
<Organic solvent Os-4>
N, N-dimethyl-β-methoxypropionamide (M100; manufactured by Idemitsu Kosan Co., Ltd.) represented by the following structural formula (4) Total HSP value: 22.5, polar HSP value: 11.0, boiling point 216 ° C.

<Organic solvent Os-5>
・ 1,3-Butanediol (manufactured by Tokyo Chemical Industry Co., Ltd.) Total HSP value: 27.8, polar HSP value: 8.1, boiling point 204 ° C
<Organic solvent Os-6>
・ 1,3-Propanediol (manufactured by Tokyo Chemical Industry Co., Ltd.) Total HSP value: 31.7, polar HSP value: 13.5, boiling point 214 ° C
<Organic solvent Os-7>
1,2-Propanediol (manufactured by ADEKA Corporation) Total HSP value: 29.1, polar HSP value: 10.4, boiling point 188 ° C.
<Organic solvent Os-8>
1-Methylene-2-propanol (manufactured by Tokyo Chemical Industry Co., Ltd.) Total HSP value: 20.4, polar HSP value: 6.3, boiling point 121 ° C.

Hereinafter, the surfactants S-1 to 3 used in Examples and Comparative Examples are shown.
<Surfactant S-1>
-Polyether-modified siloxane polymer TEGO Wet270 (manufactured by Evonik Industries)
<Surfactant S-2>
-Nonion-based surfactant Surfinol 465 (manufactured by Air Products and Chemicals, Inc.)
<Surfactant S-3>
・ Fluorine-based surfactant DSN403N (manufactured by Daikin Corporation)

A list of each of the above materials is shown in Table 1 below.

<Preparation of cyan, magenta, and yellow inks>
The materials of the formulations shown in Table 2 below were mixed and stirred, and then filtered through a 0.2 μm polypropylene filter to prepare the inks of Examples 1 to 11 and Comparative Examples 1 to 8. The types of pigment dispersion, organic solvent, and resin particles used in each ink, and the blending ratio of the organic solvent are as shown in the columns of Examples and Comparative Examples in Table 2. The numerical value in Table 2 is "mass%".
A leveling agent (DSN403N) was added to Comparative Example 8.

The inks prepared as described above were evaluated for the following evaluation items. The results are shown in Tables 3 and 4.

<Surface roughness>
The recording inks of Examples and Comparative Examples were filled in an inkjet printer IPSIO GX5500 (manufactured by Ricoh Corporation). Next, Lumi Art Gloss 130 gsm (manufactured by Stora Enso, 60 ° gloss: 26.5) was set, and solid printing was performed at a resolution of 1200 dpi so that the adhesion amount was 500 to 700 mg / A4. After drying at 100 ° C. for 1 minute, it was left at room temperature for 24 hours.
The surface roughness Ra of the recording medium before printing was 7.3 [μm]. This surface roughness Ra was measured by a method specified in JISB-0601, and LEXT OLS4100 (manufactured by Olympus Corporation) was used for the measurement, and the measurement length was 2.5 mm and the cutoff value was 0.8 mm.
The surface roughness Ra of the obtained image was measured by the same method as the measurement of the surface roughness of the recording medium.

<Gloss>
The obtained image was measured for 60 ° gloss using a gloss meter (manufactured by BYK Gardener: Micro-TRI-Gloss 4520). The evaluation criteria are as follows.
〔Evaluation criteria〕
◯: 30 or more ×: less than 30

<Scratch resistance>
For the obtained image, rub the printed part 20 times with Lumi Art Gloss 130 gsm paper cut into 1.2 mm squares to remove ink stains on the paper with a reflective color spectrophotometric densitometer (manufactured by X-Rite). The density of the rubbed paper minus the background color was evaluated according to the following criteria.
〔Evaluation criteria〕
◯: Transfer concentration is less than 0.10 ×: Transfer concentration is 0.10 or more

<Blocking property>
A total of two printed matter was prepared by the above recording method, the obtained images were superposed, and after leaving the printed matter under a pressure of 5 kg / cm ² for 24 hours, the degree of sticking between the printed matter and the state of image transfer were observed. confirmed. Further, the same evaluation was performed even when the drying conditions were changed to 100 ° C. for 5 seconds by the above recording method.
Evaluation Δ or higher is the allowable range.
〔Evaluation criteria〕
◯: There is no sticking between printed materials and there is no image transfer △: There is sticking between printed materials but there is no image transfer ×: There is sticking between printed materials and there is also image transfer

<Discharge reliability>
The inks obtained in Examples 5, 7, 8 and Comparative Example 6 were filled in an inkjet printer (IPSiO GX-e5500 (manufactured by Ricoh)), set, and continuously printed for 10 minutes, and the ink adhered to the head surface. After leaving the printer in a 50 ° C. and 60% RH environment for one month with a moisturizing cap in this state, cleaning was performed to restore the printer to the same level as before leaving. After that, an intermittent printing test was performed under the following conditions to evaluate the discharge reliability (discharge stability).
That is, after printing 20 print pattern charts in succession, a dormant state in which printing is not performed for 20 minutes is performed, this is repeated 50 times, a total of 1000 prints are made, and then another same chart is printed. The presence or absence of streaks, white spots, and jet turbulence in the 5% chart solid portion was visually evaluated according to the following criteria. As for the printing pattern, each ink was printed with 100% duty on a chart in which the printing area of each color was 5% of the total area of the paper surface. The printing conditions were a recording density of 600 × 300 dpi and one-pass printing.
The evaluation results are shown in Table 4. Ranks A and B are acceptable ranges.
[Evaluation criteria]
A: No streaks, white spots, or jet turbulence in the solid part B: Some streaks, white spots, or jet turbulence are found in the solid part C: Streaks, white spots, or jet turbulence are found in the solid part D: Whole area of the solid part Streaks, white spots, and jet turbulence are observed over

The results are shown in Tables 3 and 4. The unit of HSP value in the table is [(J / cm ³ ) ^0.5 ].

As shown in Table 3, in Examples 1 to 7, the surface roughness Ra is within the specified range, and the gloss is better than that of acrylic alone (Comparative Example 1). The difference between the HSP values of the resin and the organic solvent is also within the specified range.
Further, in Example 8, the surface roughness Ra is within the specified range, and the gloss is equivalent to that of acrylic alone (Comparative Example 1). The difference between the HSP values of the resin and the organic solvent is also within the specified range.
Further, in Example 9, the surface roughness Ra is within the specified range, and the gloss is better than that of the acrylic resin alone (Comparative Example 1). The difference between the HSP values of the resin and the organic solvent is also within the specified range. However, when the proportion of urethane resin is larger than that of acrylic resin, the blocking property is slightly inferior due to the improvement in tackiness.
Further, in Examples 10 and 11, the glass transition temperature Tg of the urethane-based resin fine particles is out of the preferable range, and the blocking property is slightly inferior.

In the case of the acrylic resin of Comparative Example 1 alone, the gloss is good but the abrasion resistance is poor, and in the case of the urethane resin of Comparative Example 2 alone, the gloss is poor and the blocking property is also deteriorated. In Comparative Examples 3 to 7, the surface roughness Ra is out of the specified range, and the gloss is equal to or worse than that of the urethane resin alone (Comparative Example 2). Further, in Comparative Example 8, the gloss is slightly improved by adding a surfactant having excellent leveling property, but it is at the same level as urethane resin alone (Comparative Example 2) and inferior to acrylic resin alone (Comparative Example 1). I understand.
Further, from Table 4, in Comparative Example 6, the HSP value distance between the solvent 1 and the solvent 2 did not satisfy the specified range, and the discharge reliability rank was inferior.

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

Japanese Unexamined Patent Publication No. 2013-248883 Japanese Unexamined Patent Publication No. 2010-024352 Japanese Unexamined Patent Publication No. 2004-131586 Japanese Unexamined Patent Publication No. 2012-207202

Claims (13)

An ink containing water, an organic solvent, and a coloring material.
The ink contains urethane-based resin particles and acrylic-based resin particles, and contains
The difference between the total HSP value of the organic solvent having the highest boiling point among the organic solvents and the total HSP value of the urethane-based resin particles is 6.0 [(J / cm ³ ) ^0.5 ] or less.
Moreover, the difference between the polar HSP value of the organic solvent having the highest boiling point among the organic solvents and the polar HSP value of the urethane-based resin particles is 5.0 [(J / cm3) 0.5] or less. Ink characterized by. The difference between the total HSP value of the organic solvent having the highest boiling point among the organic solvents and the total HSP value of the acrylic resin particles is 5.0 [(J / cm ³ ) ^0.5 ] or less. The ink according to claim 1. The ink according to claim 1 or 2 , wherein the content of the acrylic resin particles in the ink is larger than the content of the urethane resin particles in the ink. The ratio of the content of the urethane resin particles to the content of the acrylic resin particles (content of urethane resin particles / content of acrylic resin particles) is 0.1 to 0 in terms of mass ratio of solid content. The ink according to claim 3 , wherein the ink is 7. The ink according to any one of claims 1 to 4 , wherein the glass transition temperature Tg of the urethane-based resin fine particles is −20 [° C.] or more and 70 [° C.] or less. The ink according to claim 5 , wherein the glass transition temperature Tg of the urethane-based resin fine particles is −20 [° C.] or more and 25 [° C.] or less. The organic solvent contains two or more kinds of organic solvents, and among the organic solvents, the organic solvent having the lowest total HSP value is designated as solvent A, and the organic solvent having the second lowest total HSP value after the solvent A is designated as solvent B. When
The HSP value distance between the solvent A and the solvent B obtained by the following formula is 9 or less.
The ink according to any one of claims 1 to 6 , wherein the HSP value distance between the water and the solvent B obtained by the following formula is 32 or less.

The notation in the formula is as follows.
Ra: HSP value Distance δ _D2 : Non-polar HSP value of solvent B δ _D1 : Non-polar HSP value of solvent A (or water) δ _P2 : Polarity HSP value of solvent B δ _P1 : Polarity HSP of solvent A (or water) Value δ _H2 : Hydrogen-bonded HSP value of solvent B δ _H1 : Hydrogen-bonded HSP value of solvent A (or water) The organic solvent is one or more selected from N, N-dimethyl-β-butoxypropionamide, N, N-dimethyl-β-methoxypropionamide, 3-ethyl-3-hydroxymethyloxetane and propylene glycol monomethyl ether. The ink according to any one of claims 1 to 7 , wherein the ink comprises. A recorded object having an image formed on a recording medium using the ink according to any one of claims 1 to 8 . An ink cartridge comprising the ink according to any one of claims 1 to 8 contained in a container. A recording apparatus according to claim 1, further comprising an ink flying means for flying the ink according to any one of claims 1 to 8 from a recording head and recording an image on a recording medium. A recording method using the ink according to any one of claims 1 to 8.
The ink is applied to a recording medium in which a coating layer is formed on a support containing cellulose pulp and the surface roughness is 7.0 [μm] or more and 10.0 [μm] or less, and the adhesion amount is 500 to 500. A recording method characterized in that the surface roughness Ra when a solid image is formed at 700 mg / A4 is 6.0 [μm] or more and 7.5 [μm] or less. It is characterized by having an ink flying step of applying a stimulus to the ink according to any one of claims 1 to 8 via an ink flying means, flying the ink from a recording head, and recording an image on a recording medium. Recording method.

Images