JP2017165869A - Ink, ink storage container, inkjet recording method, and inkjet recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink such that a recording medium recorded by an inkjet method and others shows high glossiness and achieves both image fixability and blocking resistance.SOLUTION: An ink comprises a pigment, an organic solvent, water, a wax, and a filler. The filler includes an inorganic extender pigment. When the volume-average particle size of the wax is 1, the volume-average particle size of the filler is 1.2 or more and 3.0 or less.SELECTED DRAWING: None

Description

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

The ink jet recording method is a method of recording characters and images by ejecting a small amount of ink droplets from fine nozzles and attaching them to a recording medium such as paper. Low noise, simple process and easy colorization. Therefore, it is widely used as a home printer.
In recent years, the inkjet recording method has been expanded as commercial printing because of advantages such as variable printing and compatibility with a wide range of media. In commercial printing, there is an increasing need for printing on coated paper such as coated paper, but it is difficult to firmly fix pigments on media with low penetrability such as coated paper, resulting in poor image fixability. was there.

  Thus, as disclosed in Patent Document 1, it is disclosed that the fixability is improved by adding a resin to the ink. As the type of resin to be used, an acrylic resin is preferred from the viewpoint of the durability of the printed matter, but sufficient fixing properties have not been obtained with the acrylic resin alone. In addition, when a highly elastic urethane resin is used as in Patent Document 2, the image fixing property is improved. However, since the urethane resin is generally soft and has a high tackiness, it causes blocking that causes setback when the printed materials are stacked. There was a problem that it was easy.

Further, as disclosed in Patent Document 3, it is disclosed that adding wax to the ink is effective for improving the fixability. When wax is added to the ink, the scratch resistance is improved, but the gloss is lowered.
On the other hand, Patent Document 4 describes that both the gloss and the scratch resistance are improved by using waxes having different particle diameters.

However, by adding a wax having a large particle size and a small particle size, both gloss and scratch resistance can be achieved. However, since the wax is exposed on the surface during image formation and forms a wax layer, the ink image Therefore, the evaporation of water and organic solvents is limited, and the drying property is deteriorated. For this reason, there was a problem that blocking immediately after printing was inferior.
The present invention has been made in view of the present situation, that is, an object of the present invention is to provide an ink in which a recording medium recorded by an ink jet method or the like exhibits high gloss and has both image fixability and blocking resistance. And

The above problem is solved by the following invention (1).
(1) An ink containing a pigment, an organic solvent, water, a wax, and a filler, containing an inorganic extender pigment as the filler, and the filler having a volume average particle diameter of 1 as the filler. The volume average particle diameter of the ink is 1.2 or more and 3.0 or less.

  According to the present invention, it is possible to provide an ink in which a recording medium recorded by an ink jet method or the like exhibits high gloss and has both image fixability and blocking resistance.

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.

Hereinafter, the present invention (1) will be described in detail.
In addition, since following (2)-(9) is also contained in embodiment of this invention (1), these are also demonstrated collectively.
(2) The ink according to (1) above, wherein the wax has a volume average particle diameter of from 35 nm to 150 nm.
(3) In the above (1) or (2), the content mass of the wax in the ink is 2 or more and 50 or less when the content mass of the filler in the ink is 1. Ink.
(4) The ink according to any one of (1) to (3) above, wherein a content of the wax in the ink is 0.1% by mass or more and 4.0% by mass or less.
(5) The ink according to any one of (1) to (4), wherein the inorganic extender pigment is white carbon.
(6) A recording method comprising a heating and drying step of heating the recording medium on which the ink according to any one of (1) to (5) is attached at 100 ° C. or more.
(7) An ink jet recording method comprising an ink flying step of applying an stimulus to the ink according to any one of (1) to (5) and causing the ink to fly to form an image.
(8) An ink container, wherein the ink according to any one of (1) to (5) is contained in a container.
(9) An ink jet recording apparatus comprising the ink container described in (8) above.

The present inventors have confirmed the influence of fillers on fixability, blocking and gloss after using resin and wax to improve image fixability.
As a result, it has been found that blocking resistance is improved without impairing fixability and gloss by adding a filler to the ink. It was found that the use of a hard filler with a large particle size produced irregularities due to the filler on the surface of the image, leading to improved drying and suppression of blocking. Thus, by intensively studying the particle size and addition amount of the filler and wax, blocking was suppressed at a high level, and both high image fixability and gloss were achieved, leading to the present invention.
Specifically, when the average particle diameter of the wax is 1 and the average particle diameter of the filler is 1.2 or more and 3.0 or less, the fixability, gloss, and blocking resistance are optimal. It becomes the image surface form. The average particle size of the wax and filler can be measured using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrack Bell Co., Ltd.) as an emulsion or dispersion.

<Ink>
Hereinafter, the organic solvent, water, pigment, wax, filler, and resin particles, additives, and the like that are added as necessary will be described.

<Wax>
The wax used in the present invention is preferably a polyolefin wax, and is more preferably a polyethylene wax because it is highly effective in reducing the coefficient of friction on the surface of the image area. The wax may be either water-soluble or sparingly soluble. The water-soluble is a wax having a hydrophilic group such as a hydroxyl group, a carboxyl group, an ethylene oxide group, or an amine group, and the poorly soluble can be used as a wax emulsion. In particular, it is preferably used as a wax emulsion.

  A commercially available wax may be used, and specific examples thereof include HYTECE-8237 (polyethylene wax, melting point 106 ° C., particle size 80 nm, manufactured by Toho Chemical), AQUACER 531 (polyethylene wax, melting point 130 ° C. , Particle size 123 nm, manufactured by Big Chemie Japan).

  The volume average particle diameter of the wax is preferably 200 nm or less, and more preferably 35 nm or more and 150 nm or less from the viewpoint of image fixability and gloss. If it is 200 nm or less, good discharge is obtained without being caught by the nozzle or the filter in the head. If it is 35 nm or more, it is highly effective in reducing the coefficient of friction on the surface of the image area, and the image fixing property is improved. If it is 150 nm or less, sufficient gloss can be obtained even if wax is added. The volume average particle diameter can be measured using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrack Bell Co., Ltd.).

The content of the wax with respect to the ink is preferably in the range of 0.01% by mass to 5.0% by mass, more preferably 0.1% by mass to 4.0% by mass.
If the wax content is 0.01% by mass or more, slipperiness can be imparted to the image surface after printing, and if it is 0.1% by mass or more, the effect is sufficiently exhibited. On the other hand, if the wax content is 5.0% by mass or less, the storage stability and gloss of the ink can be improved, and if it is 4.0% by mass or less, the effect is sufficiently exhibited.

<Filler>
The filler used in the present invention is an inorganic extender pigment. Specific examples of inorganic extender pigments include silica fine particles such as silica powder, white carbon, fine silicic acid, diatomaceous earth; clay, kaolin, magnesium carbonate, calcium carbonate, barium sulfate, alumina white, talc, and transparent titanium oxide. It is done. In particular, white carbon having high hardness is preferable from the viewpoint of blocking resistance.

  The volume average particle size of the filler is desirably 60 nm or more and 240 nm or less from the viewpoint of blocking resistance and discharge. If the particle diameter is 60 nm or more, sufficient blocking resistance is obtained, and if it is 240 nm or less, good ejection properties are obtained. The volume average particle diameter can be measured using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrack Bell Co., Ltd.). Moreover, it is preferable that content of a filler is 0.002 to 2 weight% with respect to the ink total weight from the effect of blocking resistance.

  The content ratio of the filler and the wax is preferably such that the content mass of the wax is 2 or more and 50 or less when the content mass in the ink is 1. If the wax content is 2 or more with respect to the filler content, sufficient image fixability and gloss can be obtained, and if it is 50 or less, good blocking resistance is obtained.

<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.

<Color material>
The color material used in the present invention is a pigment. 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.
Examples of pigments that can be used include black pigments, yellow pigments, magenta pigments, cyan pigments, white pigments, green pigments, orange pigments, glossy pigments such as gold and silver, and metallic 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, chrome yellow as inorganic pigments Can be used.
Organic pigments include azo pigments, polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, quinofullerone pigments, etc.) Dye chelates (for example, basic dye type chelates, acidic dye type chelates), nitro pigments, nitroso pigments, aniline black, and the like can be used. Of these pigments, those having good affinity with the solvent are preferably used. In addition, resin hollow particles and inorganic hollow particles can also be used.
Specific examples of pigments include black for carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, or copper, iron (CI pigment black 11). And metal pigments such as titanium oxide, and organic pigments such as aniline black (CI Pigment Black 1).
Further, for color use, C.I. I. Pigment Yellow 1, 3, 12, 13, 14, 17, 24, 34, 35, 37, 42 (yellow iron oxide), 53, 55, 74, 81, 83, 95, 97, 98, 100, 101, 104 , 108, 109, 110, 117, 120, 138, 150, 153, 155, 180, 185, 213, C.I. I. Pigment orange 5, 13, 16, 17, 36, 43, 51, C.I. I. Pigment Red 1, 2, 3, 5, 17, 22, 23, 31, 38, 48: 2, 48: 2 (Permanent Red 2B (Ca)), 48: 3, 48: 4, 49: 1, 52: 2, 53: 1, 57: 1 (Brilliant Carmine 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81, 83, 88, 101 (Bengara), 104, 105, 106, 108 ( Cadmium red), 112, 114, 122 (quinacridone magenta), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 184, 185, 190, 193, 202, 207, 208, 209, 213, 219, 224, 254, 264, C.I. I. Pigment violet 1 (rhodamine lake), 3, 5: 1, 16, 19, 23, 38, C.I. I. Pigment Blue 1, 2, 15 (phthalocyanine blue), 15: 1, 15: 2, 15: 3, 15: 4 (phthalocyanine blue), 16, 17: 1, 56, 60, 63, C.I. I. Pigment Green 1, 4, 7, 8, 10, 17, 18, 36, etc.

  The 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. When the content of the organic pigment is 1, the content of the urethane resin is preferably 1 or more and 3 or less. When it is 1 or less, the scratching property of the image is deteriorated, and when it is 3 or more, the storage stability of the ink is deteriorated.

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.

<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.

  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 preventive agent, a pH adjuster, and the like may be added to the ink.

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

  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 fungicide>
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.

<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 method preferably includes a heating and drying process in which the recording medium to which the ink is attached is heated at 100 ° C. or higher. 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.

EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated further more concretely, this invention is not limited at all by these Examples. In the examples, “part” is “part by mass”, and “%” is “% by mass” except for those in the evaluation criteria.
Further, “average particle size” in the following description means “volume average particle size”.

<Preparation of black pigment dispersion>
Carbon black manufactured by Cabot Corporation: Black Pearls (registered trademark) 1000 (BET specific surface area 343 m 2 / g, DBPA 105 mL / 100 g) is added to 3000 N of 2.5N (normal) sodium hypochlorite solution at a temperature of 60 The mixture was stirred at a temperature of 300 ° C. and reacted at a rate of 300 rpm for 10 hours to carry out an oxidation treatment, thereby obtaining a pigment having a carbon black surface provided with a carboxylic acid group.
The reaction solution was filtered, and the carbon black separated by filtration was neutralized with a sodium hydroxide solution and subjected to ultrafiltration.
Next, ultrafiltration through a dialysis membrane was performed using the pigment dispersion and ion-exchanged water, and ultrasonic dispersion was further performed to obtain a black pigment dispersion in which the pigment solid content was concentrated to 20%.

<Preparation of cyan pigment dispersion>
In the preparation of the black pigment dispersion, a cyan pigment dispersion having a pigment solid content of 20% was obtained in the same manner except that Pigment Blue 15: 4 (SMART Cyan 3154BA manufactured by SENSIENT) was used instead of carbon black.

<Preparation of magenta pigment dispersion>
In the preparation of the black pigment dispersion, a magenta pigment dispersion having a pigment solid content of 20% was obtained in the same manner except that Pigment Red 122 (Pigment Red 122 manufactured by Sun Chemical) was used instead of carbon black.

<Preparation of yellow pigment dispersion>
In the preparation of the black pigment dispersion, a yellow pigment dispersion having a pigment solid content of 20% was obtained in the same manner except that Pigment Yellow 74 (SMART Yellow 3074BA manufactured by SENSIENT) was used instead of carbon black.

<Filler>
(Preparation of white carbon pigment dispersion)
In the preparation of the black pigment dispersion, a white carbon pigment dispersion was obtained in the same manner except that white carbon (average particle size 151 nm) was used instead of.

(Preparation of magnesium carbonate pigment dispersion)
In the preparation of the black pigment dispersion, a magnesium carbonate pigment dispersion was obtained in the same manner except that a magnesium carbonate pigment (average particle size 180 nm) was used instead of Pigment Blue 15: 4.

<Wax>
The following four waxes were used. The following products are waxes in the form of emulsions.
Wax 1: AQUACER 515 (polyethylene wax, average particle size 33 nm, manufactured by Big Chemie Japan)
Wax 2: HYTEC E-8237 (polyethylene wax, average particle size 80 nm, manufactured by Toho Chemical)
Wax 3: AQUACER 531 (polyethylene wax, average particle size 123 nm, manufactured by Big Chemie Japan)
Wax 4: Chemipearl W4005 (polyethylene wax, average particle size 200-800 nm, manufactured by Mitsui Chemicals)

<Preparation of urethane resin emulsion>
In a reaction vessel into which a stirrer, a reflux condenser, and a thermometer were inserted, 1500 g of polylite OD-X-2420 (a polyester polyol manufactured by DIC), 220 g of 2,2-dimethylolpropionic acid (DMPA) and N-methyl under nitrogen flow 1347 g of pyrrolidone (NMP) was charged and heated to 60 ° C. to dissolve DMPA. Subsequently, 1445 g of 4,4′-dicyclohexylmethane diisocyanate and 2.6 g of dibutyltin dilaurate (catalyst) were added and heated to 90 ° C. to carry out a urethanization reaction for 5 hours to obtain an isocyanate-terminated urethane prepolymer. The obtained reaction mixture was cooled to 80 ° C., 4340 g was extracted from the mixture in which 149 g of triethylamine was added and mixed, and added to a mixed solution of 5400 g of water and 15 g of triethylamine with vigorous stirring. Next, 1500 g of ice was added, 626 g of 35% 2-methyl-1,5-pentanediamine aqueous solution was added to carry out chain extension reaction, the water content was adjusted, and a urethane resin emulsion having a solid content concentration of 40% was obtained. Obtained.

<Preparation of ink>
Each ink was prepared by mixing and stirring with the formulation described in Table 1 and filtering through a 0.2 μm polypropylene filter. In addition, the numerical value in a table | surface has shown the mass part, and all the addition amount of a pigment dispersion, a wax, and a resin emulsion is represented by the mass part of solid content.

<Evaluation 1: Image fixability evaluation>
A 6 cm square solid image was printed at 100 duty on a Lumi Art Gross (90 gms) using a printer (GXe5500, manufactured by Ricoh), and immediately after printing at 100 ° C. with a constant-temperature dryer (AS-One OF-300B) for 180 seconds. Dried. Next, the solid part printed on the Lumi Art Gross (90 gms) attached to the clock meter (manufactured by Toyo Seiki Co., Ltd.) is rubbed and reciprocated 10 times, and the dirt adhering to the rubbed paper is X-rite (manufactured by X-rite). Densitometer) and evaluated according to the following criteria. “OD” is “optical density”.
(Evaluation criteria)
◎… Transfer OD is less than 0.10
○: Transfer OD is 0.10 or more and less than 0.15
Δ: Transfer OD is 0.15 or more and less than 0.20 ×: Transfer OD is 0.20 or more

<Evaluation 2: Gloss evaluation>
The same image as that used for the image fixing property evaluation was obtained, and the obtained image was measured for 60 ° gloss using a gloss meter (by BYK Gardner: Micro-TRI-Gloss 4520).
◎… Glossiness is 35 or more
○… Glossiness is 25 or more and less than 35
Δ: Glossiness of 15 or more and less than 25 ×: Glossiness of less than 15

<Evaluation 3: Blocking resistance evaluation>
Using a printer (GXe5500, manufactured by Ricoh Co., Ltd.), a solid portion of 6 cm square was printed on a recording medium, dried at 100 ° C. for 180 seconds, and then a recording medium (interleaf paper) that was not printed was stacked on the printing surface. This was sandwiched between two 10 × 10 cm square glass plates, and left standing in an environment of 60 ° C. and 70% for 24 hours under a load of 0.5 kg / cm ^2, and then in accordance with the following criteria: The degree of blocking was evaluated.
A: No blocking.
○: Slightly blocking (slightly transferred to interleaf)
△: Quite blocking (the transfer part can be clearly seen on the interleaf)
X: Completely blocking (difficult to adhere and peel off)

Examples 1 to 9 are particularly preferred examples of the present invention, and it can be seen that all of blocking resistance, image fixing property and gloss are good.
In Example 10, the filler content is outside the range of the numerical value defined in the third embodiment of the present invention, and the blocking resistance and the image fixing property are slightly inferior, but there is no practical problem.
Example 11 is an example in which the filler content is higher than the numerical value specified in 3) of the embodiment of the present invention, and is at a level where there is no practical problem although the blocking resistance is lowered.
Example 12 is an example in which the content of the wax is small outside the numerical range defined in 4) of the embodiment of the present invention, and the image fixing property and blocking resistance are slightly inferior, but there is no practical problem. It is.
Example 13 is a case where the wax content is higher than the value specified in 4) of the embodiment of the present invention, and the image gloss is lowered, but there is no practical problem.

  Comparative Example 1 is an example containing no inorganic extender pigment, and the blocking resistance is extremely poor. Comparative Examples 2 to 4 are examples in which the average particle size ratio of the wax and the filler does not satisfy the numerical range defined in the present invention. When the average particle size of the wax is small and the average particle size ratio of the filler is large, the image Fixability is not at a practically sufficient level. Further, when the average particle size of the wax is large and the average particle size of the filler is small, there is a problem in gloss and blocking resistance.

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 434 Discharge head 436 Supply tube L Ink storage container

JP 2010-024352 A JP 2004-131586 A JP 2005-48108 A JP 2007-277290 A

Claims (9)

  An ink comprising a pigment, an organic solvent, water, a wax, and a filler, containing an inorganic extender pigment as the filler, and the volume average particle diameter of the filler when the volume average particle diameter of the wax is 1. An ink having a particle size of 1.2 to 3.0.   2. The ink according to claim 1, wherein the wax has a volume average particle diameter of 35 nm or more and 150 nm or less.   3. The ink according to claim 1, wherein when the content mass of the filler in the ink is 1, the content mass of the wax in the ink is 2 or more and 50 or less.   The ink according to any one of claims 1 to 3, wherein a content of the wax in the ink is 0.1% by mass or more and 4.0% by mass or less.   The ink according to claim 1, wherein the inorganic extender pigment is white carbon.   A recording method comprising a heating and drying step of heating the recording medium having the ink according to claim 1 attached thereto at 100 ° C. or more.   An ink jet recording method comprising an ink flying step of applying an stimulus to the ink according to claim 1 and causing the ink to fly to form an image.   An ink storage container, wherein the ink according to claim 1 is stored in a container.   An ink jet recording apparatus comprising the ink container according to claim 8.

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