JP2017024412A - Set of ink and media for recording, inkjet recording method, inkjet recording device, and recorded material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a set of ink and media for recording which is excellent in scratch resistance and glossiness, can form an image having a high image density, and is excellent in blocking properties and maintainability of a nozzle.SOLUTION: There is provided a set of ink and media for recording which contains an organic solvent, polyurethane resin particles, a coloring agent and water, where the organic solvent contains a compound having a saturated vapor pressure at 100°C of 65 mmHg or more and 400 mmHg or less, and has a sensor output value at a critical image peeling point by a microscratch method in a solid image, where an amount of adhesion of the ink formed on the media for recording is 0.96 mg/cm, of 600 or more.SELECTED DRAWING: None

Description

  The present invention relates to a set of ink and a recording medium, an ink jet recording method, an ink jet recording apparatus, and a recorded matter.

  Conventionally, inks used in ink jet recording methods generally contain a colorant, an organic solvent, and water. As the colorant, a dye is mainly used from the viewpoint of excellent color developability and stability, but durability such as light resistance and water resistance of an image obtained using a dye ink is insufficient. The durability has been improved to some extent by improving the ink jet recording paper having an ink absorbing layer, but it was not satisfactory for plain paper.

In recent years, pigment inks using pigments as colorants have been used. Although the pigment ink greatly improves the durability of the light resistance and water resistance of the image, which is a drawback of the dye ink, light of different wavelengths and phases interferes due to multiple reflection of light inside the pigment. Therefore, there is a problem that the glossiness is lowered.
In addition, since the image obtained with the pigment ink may be difficult to fix the pigment on the recording medium, the scratch resistance when the image is rubbed with a finger or paper is inferior, and the recording medium becomes dirty. In particular, in the case of a recording medium that does not absorb ink more easily than plain paper, such as coated paper, the pigment in the ink tends to stay on the surface, and the abrasion resistance is remarkably deteriorated.

In order to solve the above-mentioned problems, for example, an ink containing polycarbonate-based polyurethane resin particles and having a surface hardness of 100 N / mm ² or more to form a hard ink coating, thereby improving the scratch resistance Has been proposed (see, for example, Patent Document 1).

  There is also a proposal to improve the film formability of an ink image and improve the film strength after film formation by adding two kinds of resins having low glass transition temperature (Tg) and different Tg in the ink. (For example, refer to Patent Document 2).

  SUMMARY OF THE INVENTION An object of the present invention is to provide a set of an ink and a recording medium that has excellent scratch resistance and glossiness, can form an image with high image density, and has excellent blocking properties and nozzle maintenance properties.

The set of ink and recording medium of the present invention as means for solving the above problems is a set of ink and recording medium containing an organic solvent, polyurethane resin particles, a colorant, and water,
The organic solvent contains a compound having a saturated vapor pressure at 100 ° C. of 65 mmHg or more and 400 mmHg or less,
The sensor output value at the critical image peeling point by the micro scratch method is 600 or more in a solid image in which the amount of the ink formed on the recording medium is 0.96 mg / cm ² .

  According to the present invention, it is possible to provide an ink and recording medium set that is excellent in scratch resistance and glossiness, can form an image with high image density, and has excellent blocking properties and nozzle maintenance properties.

FIG. 1 is a schematic diagram showing how the sensor output value at the critical image peeling point is measured by the micro scratch method. FIG. 2 is an external perspective view illustrating an example of the ink container. FIG. 3 is an explanatory perspective view illustrating an example of the ink supply port portion of the ink container before the cap member is mounted. FIG. 4 is an exploded perspective view showing an example of the ink supply port portion. FIG. 5 is a schematic view showing an example of the ink jet recording apparatus of the present invention. FIG. 6 is a schematic view showing an example of a pretreatment process section of the ink jet recording apparatus of the present invention. FIG. 7 is a schematic view showing an example of four head units of the ink jet recording apparatus of the present invention. FIG. 8 is an enlarged view of one of the four head units of FIG.

(Ink and recording media set)
The set of ink and recording medium of the present invention is a set of ink and recording medium containing an organic solvent, polyurethane resin particles, a colorant, and water,
The organic solvent contains a compound having a saturated vapor pressure at 100 ° C. of 65 mmHg or more and 400 mmHg or less,
The sensor output value at the critical image peeling point by the micro scratch method is 600 or more in a solid image in which the amount of the ink formed on the recording medium is 0.96 mg / cm ² .
In the terminology of the present invention, image formation, recording, printing, printing, etc. are all synonymous.

The set of the ink and the recording medium of the present invention contains the polycarbonate-based polyurethane resin particles described in Patent Document 1 and is an ink coating film that forms a hard ink coating film having a surface hardness of 100 N / mm ² or more. This is based on the finding that the surface scratch resistance of the image is not sufficiently satisfactory because the surface hardness of the ink film is too high and the brittle nature of the ink coating film appears.
In addition, the ink and recording medium set of the present invention has a minimum film-forming temperature in an ink having two types of resins having low glass transition temperatures (Tg) described in Patent Document 2 and having different Tg. Since it is very low, the film-forming speed in the image drying process is high, and it is difficult to form a uniform film, so that it is difficult to obtain sufficient scratch resistance and image gloss. If the minimum film-forming temperature is low, if the nozzle of the head is left uncovered for a long time without being capped, a film is formed at the meniscus portion of the nozzle, and the maintainability also deteriorates. Furthermore, if the glass transition temperature of the resin is too low, tackiness is developed in the resin, so that the image is discharged after recording, and when it is wound up with a roll or stacked, blocking is likely to occur. It is based on.

As a result of intensive studies to solve the deterioration of scratch resistance caused by the pigment remaining on the surface of the coated paper for printing (coated paper) that hardly absorbs ink, the present inventors have obtained polyurethane resin particles. The sensor output value at the critical image peeling point by the micro scratch method is 600 or more in a solid image in which the adhesion amount of the ink formed on the recording medium using the contained ink is 0.96 mg / cm ^2. It was found that the scratch resistance of the image was improved.

  In addition, since the polyurethane resin particles have high polarity and strong cohesive force, it is possible to form a uniform ink coating film compared to resin particles of other compositions, which is considered to be advantageous in improving the scratch resistance. It is easy to take in water and organic solvent therein, and the drying property of the image tends to deteriorate. However, when the ink contains a compound having a saturated vapor pressure of 65 mmHg or more and 400 mmHg or less as an organic solvent at 100 ° C., the drying property of the image can be improved even if the polyurethane resin particles are used, and the ink is wound up by a roll. It has been found that blocking that occurs when stacking is improved.

In the present invention, the sensor output value at the critical image peeling point by the micro scratch method in a solid image in which the amount of ink deposited on the recording medium is 0.96 mg / cm ² is 600 or more, 600 or more and 1,000 or less are preferable, and 620 or more and 850 or less are more preferable.
When the sensor output value is 600 or more, the polyurethane resin particle film formation proceeds efficiently in the ink coating film after recording, the adhesion strength of the ink coating film becomes strong, and it becomes difficult to scrape due to friction.

-Measurement of sensor output value at critical image peeling point in micro scratch test method-
The sensor output value at the critical image peeling point in the micro scratch test method can be measured as follows (based on JIS R3255-1997 “Testing Method for Adhesion of Thin Film Using Glass as Substrate”).
The ink is filled in an ink jet printer (for example, IPSIO GX5500, manufactured by Ricoh Co., Ltd.), and coated on coated paper (for example, Lumi Art Gloss 130 gsm paper, manufactured by Stora Enso) at a resolution of 1,200 dpi as a recording medium. A solid image having an adhesion amount of 0.96 mg / cm ² (600 mg / A4 size) is formed. Thereafter, the solid image was dried for 30 seconds in a thermostatic bath set to have an internal temperature of 100 ° C. The dried solid image is measured under the following conditions with a micro scratch tester (CSR-2000, manufactured by Resuka Co., Ltd.), and the sensor output value at the critical image peeling point (when the solid image peels) is read. Note that the number of times of measurement is 1, and the measurement position is the center of the solid image.

(1) Equipment used: CSR-2000 manufactured by Resuka Co., Ltd.
(2) Measurement conditions • Scratch speed: 20 μm / s
・ Measurement time: 30 seconds ・ Load at the end of measurement: 10 mN
・ Amplitude level: 100 μm
・ Excitation frequency: 45Hz
・ Data sampling: 3735Hz
・ Spring constant: 100 g / mm
-Stylus (diamond needle) diameter: 5 μm

  The micro-scratch method applies a record needle cartridge detection mechanism. The principle of the micro scratch method is that a diamond needle is provided at the tip of a cantilever, and when the diamond needle scans on the ink film of a solid image, a minute change on the surface of the solid image can be captured with high sensitivity. it can. The vibration at the tip of the diamond needle is converted into an electrical signal inside the cartridge through the cantilever and captured. By scanning while gradually increasing the scratch load, the solid color ink film peels from the recording medium (critical image peeling point). A value corresponding to the force applied to the diamond needle at the critical image peeling point is expressed as a sensor output value (according to JIS R3255-1997 “Testing Method for Adhesion of Thin Film Using Glass as Substrate”). It can be said that as the sensor output value is larger, the ink coating is more difficult to peel off.

Here, the measurement method by the micro scratch method will be described with reference to FIG. The direction of the diamond needle 1 from the start point 2 to the end point 3 on the solid image 6 formed on the recording medium 7 and having a resolution of 1,200 dpi and an ink adhesion amount of 0.96 mg / cm ² (600 mg / A4 size) ( In the scratch direction 5), the diamond needle 1 is scanned on the solid image 6 while gradually increasing the scratch load. When a scratch load of a certain level or more is applied to the solid image 6, the ink coating film of the solid image 6 cannot withstand the scratch load, and the ink coating film peels off and peels off from the recording medium 7. This point is defined as a critical image peeling point 4, and a value corresponding to the force applied to the diamond needle 1 at the critical image peeling point 4 is read as a sensor output value.

-Measurement of arithmetic average roughness Ra of image-
The arithmetic average roughness Ra of a solid image having an ink adhesion amount of 0.96 mg / cm ² formed on a recording medium is preferably 0.2 μm or more and 0.9 μm or less, and preferably 0.3 μm or more and 0.8 μm or less. More preferred.
When the arithmetic average roughness Ra is 0.2 μm or more and 0.9 μm or less, the film formation by the polyurethane resin particles proceeds efficiently, the adhesion between the colorant and the polyurethane resin film is improved, and the solid image surface is rubbed. In this case, the colorant is hardly peeled off from the image, and the scratch resistance is improved. Further, since the image surface is uniform, glossiness and image density are improved.

The arithmetic average roughness Ra of the image can be measured, for example, as follows.
The ink is filled into an ink jet printer (for example, IPSIO GX5500, manufactured by Ricoh Co., Ltd.), and the ink adheres to coated paper (for example, Lumi Art Gloss 130 gsm paper, manufactured by Stora Enso) as a recording medium at a resolution of 1,200 dpi. A solid image having an amount of 0.96 mg / cm ² (600 mg / A4 size) is formed. Thereafter, the solid image was dried for 30 seconds in a thermostatic bath set so that the internal temperature was 100 ° C.
Next, an arithmetic roughness of the solid image is obtained from the dried solid image using a laser microscope (for example, VK-850, manufactured by Keyence Corporation) under a measurement pitch of 0.1 μm. An area of 0.4 mm is scanned 10 times in the vertical direction of the solid image, and the average value is defined as the arithmetic average roughness Ra.

<Recording media>
The recording medium in the ink and recording medium set of the present invention is not particularly limited and can be appropriately selected according to the purpose. For example, plain paper, coated paper for printing, glossy paper, special paper, A cloth, a film, an OHP sheet, etc. are mentioned. These may be used alone or in combination of two or more. Among these, coated paper for printing is preferable.
Since the coated paper for printing is generally inferior in ink absorbability to plain paper, it is often used in combination with a drying means after recording for application to inkjet, but there is a problem with drying properties of conventional images. was there. Even if the ink in the set of ink and recording medium is recorded on the coated paper for printing, the image drying property can be satisfied.

As the recording medium, a commercially available product can be used. Examples of the commercially available product include OK top coat, OK astro gloss, OK non-wrinkle, SA Kanto +, OK Kanto +, OK non-wrinkle, (F ) MCOP, OK Astro Dal, OK Astro Matte, OK Ultra Aqua Satin, OK Embossed Silk, OK Embossed Pear, OK Embossed Cloth, OK Embossed Home Span, OK Opto Gloss, OK Bulk King, OK Casablanca, OK Casablanca V, OK Casablanca-X, OK Kanto single side, OK coat L, OK coat L green 100, OK coat N green 100, OK coat V, OK medium coat (for offset), OK top coat S, OK top coat dull, OK top coat mat N, OK Trinity, OK Trinity N Vi, OK Trinity NaVi-V, OK Neo Top Coat, OK Neo Top Coat Mat, OK Non Wrinkle AL, OK Non Wrinkle DL, OK Non Wrinkle BL, OK White L, OK Matt Coat L Green 100, OK Matt Coat Green 100 , OK Royal Coat, OK White L, Z Coat, Z Coat Green 100, Ultra Satin Kinto N, Golden Matt, Satin Kinto N, New Age, New Age Green 100, Mirror Coat Gold, Mirror Coat Platinum, Royal Coat L , Roston Color, POD Super Gloss, POD Gloss Coat, POD Matt Coat (above Oji Paper Co., Ltd.), Broad Mat A, Broad Gloss A, White Pearl Coat N, New V Matt, Pearl Coat, D Niti, Bistagros, N Pearl Coat L, Utrillo, EP-D Gloss, EP-L Gloss, EP-L Matt, EP-D Premium White, EP-Super Quality, (Mitsubishi Paper Industries, Ltd.), Hi- a, α mat, Kinmari Hi-L, mu coat, mu mat, mu white (Hokuetsu Kishu Paper Co., Ltd.), Lumi Art Gloss paper (manufactured by Stora Enso), and the like. These may be used alone or in combination of two or more.
Among these, Lumi Art Gloss paper is preferable. Since the Lumi Art Gloss paper has low ink absorbability, satisfactory ink drying may not be obtained when using a general inkjet ink. However, when the ink of the present invention is used, good drying is obtained. be able to.

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

  The recording media are not limited to those used as general recording media, and wallpaper, flooring, building materials such as tiles, cloth for clothing such as T-shirts, textiles, leather, etc. may be used as appropriate. it can. Moreover, ceramics, glass, metal, etc. can also be used by adjusting the structure of the path | route which conveys the recording medium.

<Ink>
The ink of the ink and recording medium set of the present invention contains an organic solvent, polyurethane resin particles, a colorant, and water, and further contains other components as necessary.

<< Polyurethane resin particles >>
Since the polyurethane resin particles have high polarity and strong cohesive force, they can form a uniform and strong ink coating film compared to other resin particles, and can improve the scratch resistance of images.

  The polyurethane resin particles are not particularly limited and can be appropriately selected depending on the purpose. For example, the polyurethane resin particles can be obtained by reacting a polyol and a polyisocyanate.

  Examples of the polyol include polyether polyol, polycarbonate polyol, and polyester polyol. These may be used individually by 1 type and may use 2 or more types together.

-Polyether polyol-
Examples of the polyether polyol include those obtained by subjecting at least one compound having two or more active hydrogen atoms to a starting material to which an alkylene oxide is loaded.

  Examples of the starting material include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, glycerin, and trimethylolethane. And trimethylolpropane. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, and tetrahydrofuran. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the polyether polyol include polyoxytetramethylene glycol, polyoxypropylene glycol and the like from the viewpoint of obtaining an ink binder capable of imparting very excellent scratch resistance. These may be used individually by 1 type and may use 2 or more types together.

-Polycarbonate polyol-
Examples of the polycarbonate polyol that can be used for the production of the polyurethane resin particles include those obtained by reacting a carbonate with a polyol, and those obtained by reacting phosgene with bisphenol A and the like. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the carbonate ester include methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, and diphenyl carbonate. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the polyol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 1, 2-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 2,5-hexanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8 -Octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, hydroquinone, resorcinol , Bisphenol-A, bisphe Relatively low molecular weight dihydroxy compounds such as polyol-F, 4,4′-biphenol, polyether polyols such as polyethylene glycol, polypropylene glycol, polyoxytetramethylene glycol, polyhexamethylene adipate, polyhexamethylene succinate, poly Examples thereof include polyester polyols such as caprolactone. These may be used individually by 1 type and may use 2 or more types together.

-Polyester polyol-
Examples of the polyester polyol include those obtained by esterifying low molecular weight polyols and polycarboxylic acids, polyesters obtained by ring-opening polymerization reaction of cyclic ester compounds such as ε-caprolactone, and copolymers thereof. Examples include polyester. These may be used individually by 1 type and may use 2 or more types together.

Examples of the low molecular weight polyol include ethylene glycol and propylene glycol. These may be used alone or in combination of two or more.
Examples of the polycarboxylic acid include succinic acid, adipic acid, sebacic acid, dodecanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, anhydrides or ester-forming derivatives thereof. These may be used individually by 1 type and may use 2 or more types together.

-Polyisocyanate-
Examples of the polyisocyanate include aromatic diisocyanates such as phenylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate and naphthalene diisocyanate; hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene Examples thereof include aliphatic or alicyclic diisocyanates such as diisocyanate and 2,2,4-trimethylhexamethylene diisocyanate. These may be used individually by 1 type and may use 2 or more types together. Among these, since the ink used in the present invention is also used for outdoor applications such as posters and billboards, it requires a coating film with very high long-term weather resistance, from the viewpoint of the long-term weather resistance, Aliphatic or alicyclic diisocyanates are preferred.

Furthermore, the use of at least one alicyclic diisocyanate makes it easy to obtain the desired coating strength and scratch resistance.
Examples of the alicyclic diisocyanate include isophorone diisocyanate and dicyclohexylmethane diisocyanate.
As content of the said alicyclic diisocyanate, 60 mass% or more is preferable with respect to the isocyanate compound whole quantity.

-Manufacturing method of polyurethane resin particles-
The polyurethane resin particles are not particularly limited, and can be obtained by a conventionally commonly used production method.
First, an isocyanate-terminated urethane prepolymer is produced by reacting the polyol and the polyisocyanate in an equivalent ratio in which an isocyanate group becomes excessive in the absence of a solvent or in the presence of an organic solvent.
Next, the anionic group in the isocyanate-terminated urethane prepolymer is neutralized with a neutralizing agent as necessary, and then reacted with a chain extender, and finally the organic solvent in the system is removed as necessary. Can be obtained.

Examples of the organic solvent that can be used in the production of the polyurethane resin particles include ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran and dioxane; acetates such as ethyl acetate and butyl acetate; nitriles such as acetonitrile; Examples include amides such as formamide, N-methylpyrrolidone, and N-ethylpyrrolidone. These may be used alone or in combination of two or more.
Examples of the chain extender include polyamines and other active hydrogen group-containing compounds.

  Examples of the polyamine include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4′-dicyclohexylmethanediamine, and 1,4-cyclohexane. Diamines such as diamines; Polyamines such as diethylenetriamine, dipropylenetriamine and triethylenetetramine; Hydrazines such as hydrazine, N, N′-dimethylhydrazine and 1,6-hexamethylenebishydrazine; Succinic dihydrazide, Adipic dihydrazide And dihydrazides such as glutaric acid dihydrazide, sebacic acid dihydrazide, and isophthalic acid dihydrazide. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the other active hydrogen group-containing compounds include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexamethylene glycol, Glycols such as saccharose, methylene glycol, glycerin, sorbitol; phenols such as bisphenol A, 4,4′-dihydroxydiphenyl, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenyl sulfone, hydrogenated bisphenol A, hydroquinone Kind; water etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.

  The polyurethane resin particles are preferably polycarbonate-based urethane resin particles from the viewpoint of water resistance, heat resistance, abrasion resistance, weather resistance, and image scratch resistance due to the high cohesive strength of carbonate groups. When the polycarbonate-based urethane resin particles are used, an ink suitable for a recorded matter used in a harsh environment such as an outdoor use can be obtained.

  When the polyurethane resin particles are dispersed in an aqueous medium, the dispersion may be forcibly emulsified by adding a dispersant, but the dispersant may remain in the ink coating film and lower the strength. Therefore, it is preferable that an anionic group is arranged in the structure of the polyurethane resin particles and dispersed by so-called self-emulsification. In that case, it is preferable that the anionic group has an acid value of 20 mgKOH / g to 100 mgKOH / g in order to impart excellent scratch resistance and chemical resistance.

  Examples of the anionic group include a carboxyl group, a carboxylate group, a sulfonic acid group, and a sulfonate group. Among these, a carboxylate group or a sulfonate group partially or wholly neutralized with a basic compound or the like is preferable from the viewpoint of maintaining good water dispersion stability.

  Examples of basic compounds that can be used to neutralize the anionic group include organic amines such as ammonia, triethylamine, pyridine, and morpholine, alkanolamines such as monoethanolamine, Na, K, Li, and Ca. And metal base compounds containing

  The weight average molecular weight of the polyurethane resin particles is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 5,000 to 500,000 from the viewpoint of ink storage stability and dischargeability. Is more preferable, and 10,000 to 300,000 is still more preferable.

The weight average molecular weight (Mw) of the polyurethane resin particles is a gel permeation chromatography (GPC) measuring device (for example, the device is GPC-8220GPC, manufactured by Tosoh Corporation, the column is TSKgel SuperHZM-H, 15 cm, 3 series. , Manufactured by Tosoh Corporation).
The polyurethane resin particles to be measured were made into a 0.15 mass% solution in tetrahydrofuran (THF) (containing a stabilizer, manufactured by Wako Pure Chemical Industries, Ltd.), filtered through a filter having an average pore size of 0.2 μm, and the filtrate was then used. Used as a sample. 100 μL of the THF sample solution is injected into a measuring apparatus and measured at a flow rate of 0.35 ml / min in an environment at a temperature of 40 ° C. The molecular weight of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts. Examples of the polystyrene standard sample include Stowd STANDARD Std. No S-7300, S-210, S-390, S-875, S-1980, S-10.9, S-629, S-3.0, S-0.580 (above, manufactured by Showa Denko KK ), And toluene as the diluent solvent. An RI (refractive index) detector can be used as the detector.

As for the glass transition temperature (Tg) of the said polyurethane resin particle, -30 degreeC or more and 10 degrees C or less are preferable.
When the glass transition temperature is −30 ° C. or higher and 10 ° C. or lower, the polyurethane resin particles have excellent film forming properties and a uniform ink coating film can be formed, so that the image scratch resistance can be improved.
When the glass transition temperature is −30 ° C. or higher, the polyurethane resin particles are less likely to exhibit tackiness, and thus blocking deterioration due to the inclusion of the polyurethane resin particles can be suppressed. Further, since film formation on the head nozzle surface in the decap state is unlikely to occur, the maintainability of the nozzle is also improved. Further, when the glass transition temperature is 10 ° C. or less, the film-forming property is improved, and it is effective for improving the scratch resistance of the image, the glossiness is improved, and a high image density can be realized.

Here, the glass transition temperature of the polyurethane resin particles can be determined from an endothermic chart of a differential scanning calorimeter (for example, Q2000, manufactured by TA Instruments Japan). Specifically, 5 mg to 10 mg of the polyurethane resin particles obtained by evaporating the moisture and solvent of the polyurethane resin particles and drying them are weighed and filled in a simple air-tight pan made of aluminum, and used for the following measurement flow.
・ First heating: Heated from 30 ° C. to 220 ° C. at 5 ° C./minute, held for 1 minute after reaching 220 ° C. • Cooling: Quenched to −60 ° C. without temperature control, held for 1 minute after reaching −60 ° C. Second time: Heating from −60 ° C. to 180 ° C. at 5 ° C./min. In the second heating thermogram, the value was read using the midpoint method (ASTM D3418 / 82, ASTM International), and this was the glass transition temperature. And

The volume average particle diameter of the polyurethane resin particles is preferably 8 nm or more and 19 nm or less.
When the volume average particle diameter is 8 nm or more and 19 nm or less, the ink coating film becomes uniform on the image surface, and the scratch resistance of the image can be improved. Further, the dispersion becomes stable, and the storage stability of the ink is improved.
When the volume average particle size is 8 nm or more, the ink coating film becomes uniform and the coefficient of friction of the image surface is appropriate, which is advantageous for improving the scratch resistance. Further, when the volume average particle size is 19 nm or less, polyurethane resin particles efficiently enter the gaps between the pigments, and the uniformity of the ink coating film is improved, which is effective in improving the scratch resistance of the image. At the same time, the gloss and the image density are improved.

The volume average particle diameter of the polyurethane resin particles can be measured using a dynamic light scattering method (for example, Microtrac UPA-150, manufactured by Nikkiso Co., Ltd.) in an environment of 55% RH at 23 ° C. The volume average particle diameter means the volume average particle diameter (D ₅₀ ) at 50% accumulation.

The mass ratio (A / B) between the content A (mass%) of the polyurethane resin particles and the content B (mass%) of the colorant is preferably 1 or more and 5 or less, more preferably 1 or more and 4 or less. 3 or more and 4 or less are more preferable.
When the mass ratio (A / B) is 1 or more and 5 or less, a uniform ink coating film can be obtained, and the scratch resistance of the image can be improved.
When the mass ratio (A / B) is 1 or more, the colorant is easily dispersed uniformly in the polyurethane resin film, and the ink coating surface becomes smooth, which is effective in improving the scratch resistance. In addition, the image density and the glossiness can be improved. Further, when the mass ratio (A / B) is 5 or less, the deterioration of blocking due to the inclusion of an organic solvent in the polyurethane resin particles and the deterioration of nozzle maintenance due to film formation on the head nozzle surface in a decap state are suppressed. can do.

<< Organic solvent >>
As said organic solvent, the saturated vapor pressure in 100 degreeC contains 65 mmHg or more and 400 mmHg or less.
When the saturated vapor pressure at 100 ° C. is 65 mmHg or more, the drying efficiency is remarkably improved, which is effective in improving the image drying property. Further, when the saturated vapor pressure at 100 ° C. is 400 mmHg or less, the moisturizing effect of the organic solvent is appropriate, and the maintainability (suction return property) of the nozzle is improved.

In the present invention, when polyurethane resin particles are contained in the ink in order to improve scratch resistance and glossiness, water and organic solvents are held in by the polarity of the polyurethane resin particles, so that the image drying property is deteriorated. It becomes easy. As a result, there may occur a blocking phenomenon in which the images or the images and the recording medium stick to each other when the images after recording are discharged and wound up by a roll, or left for a long time after being stacked.
Therefore, by having a compound having a saturated vapor pressure of 65 mmHg or more and 400 mmHg or less at 100 ° C. in the ink, drying of the image after recording can be effectively improved even with an ink containing polyurethane resin particles. Blocking can be suppressed.

  Examples of the compound having a saturated vapor pressure of from 65 mmHg to 400 mmHg at 100 ° C. include propylene glycol monopropyl ether (saturated vapor pressure of 105 mmHg at 100 ° C.), propylene glycol monomethyl ether (saturated vapor pressure of 380 mmHg at 100 ° C.), 3- Examples thereof include methoxybutanol (saturated vapor pressure at 100 ° C .: 92 mmHg), ethylene glycol monobutyl ether (saturated vapor pressure at 100 ° C .: 68 mmHg), and the like. These may be used alone or in combination of two or more. Among these, in the drying step, the polyurethane resin particles easily spread uniformly on the surface of the image, and can form an image having scratch resistance, image density, and high glossiness, so that propylene glycol monopropyl ether, propylene glycol monomethyl ether, 3 -Methoxybutanol is preferred, and propylene glycol monopropyl ether and propylene glycol monomethyl ether are particularly preferred from the viewpoint of improving blocking.

The content of the compound having a saturated vapor pressure at 100 ° C. of 65 mmHg to 400 mmHg is preferably 10% by mass to 25% by mass, and more preferably 10% by mass to 20% by mass with respect to the total amount of the ink.
When the content is 10% by mass or more, the image drying efficiency is remarkably improved, and it is effective for suppressing blocking. Further, when the content is 25% by mass or less, the moisturizing effect of the organic solvent is appropriate, so that the maintenance property (suction return property) of the nozzle is improved.

The mass ratio (C / A) between the content A (mass%) of the polyurethane resin particles and the content C (mass%) of the compound having a saturated vapor pressure of 65 mmHg or more and 400 mmHg or less at 100 ° C. is 0.85. It is preferably 3.0 or more and more preferably 0.9 or more and 2.5 or less.
When the mass ratio (C / A) is 0.85 or more, the drying property of the ink is improved, so that blocking can be suppressed. In addition, when the mass ratio (C / A) is 3.0 or less, the polyurethane resin particles are less likely to swell with the organic solvent, so that an increase in the viscosity of the ink over time can be suppressed, and the storage stability of the ink can be suppressed. Property is improved.

  As the organic solvent, the higher the permeation speed of the organic solvent after the ink is ejected from the head to the recording medium, the higher the colorant is fixed on the recording medium. An image is obtained. For this reason, it is preferable to use the compound whose solubility parameter (SP value) is 11.0 to 14.0.

The SP value is a value defined by the regular solution theory introduced by Hildebrand, and is a measure of the solubility of the binary solution. The SP value described in the present invention is a value calculated by the Fedors method, and is indicated by the square root of the cohesive energy density in the regular solution theory, and the unit is (J / cm ³ ) ^0.5 . The SP value can be generally calculated with popular simple software.

  Examples of the compound having a solubility parameter (SP value) of 11.0 to 14.0 include 3-ethyl-3-hydroxymethyloxetane (SP value: 11.31), 3-methyl-1,3- Butanediol (SP value: 12.05), 1,2-butanediol (SP value: 12.75), 1,3-butanediol (SP value: 12.75), 1,4-butanediol (SP value) : 12.95), 2,3-butanediol (SP value: 12.55), 1,2-propanediol (SP value: 13.48), 1,3-propanediol (SP value: 13.72) 1,2-hexanediol (SP value: 11.80), 1,6-hexanediol (SP value: 11.95), 3-methyl-1,5-pentanediol (SP value: 11.80), Triethylene glycol ( P value: 12.12), diethylene glycol (SP value: 13.02), and the like. These may be used alone or in combination of two or more. Among these, 3-ethyl-3-hydroxymethyloxetane, 3-methyl-1,3-butanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3- Butanediol, 1,2-propanediol and 1,3-propanediol are preferred.

  As the organic solvent, in addition to the compound having a saturated vapor pressure of from 65 mmHg to 400 mmHg at 100 ° C. and the compound having the solubility parameter (SP value) of 11.0 to 14.0, other organic solvents are used in combination. can do.

  The other organic solvent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, ethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, trimethylolethane , Trimethylolpropane, 1,5-pentanediol, hexylene glycol, glycerin, 1,2,3-butanetriol, 1,2,4-butanetriol, 1,2,6-hexanetriol, isopropylideneglycerol, petri Polyhydric alcohols such as all; ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol Polyhydric alcohol alkyl ethers such as dimethyl monobutyl ether, tetraethylene glycol monomethyl ether and propylene glycol monoethyl ether; Polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether; 2-pyrrolidone, N-methyl Nitrogen-containing heterocyclic compounds such as 2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethylimidazolidinone, ε-caprolactam, γ-butyrolactone; formamide, N-methylformamide, N, N- Amides such as dimethylformamide, 3-methoxy-N, N-dimethylpropionamide, 3-butoxy-N, N-dimethylpropionamide; monoethanolamine, diethanolamine, triethano Triethanolamine, monoethylamine, diethylamine, amines such as triethylamine; dimethyl sulfoxide, sulfolane, sulfur-containing compounds such as thiodiethanol; propylene carbonate, and the like ethylene carbonate. These may be used individually by 1 type and may use 2 or more types together.

The content of the organic solvent (the total content when two or more organic solvents are used) is preferably 15% by mass or more and 60% by mass or less with respect to the total amount of the ink.
When the content is 15% by mass or more, an image having excellent glossiness and a high image density can be obtained, and when the content is 60% by mass or less, the image quality is good, the ink viscosity is appropriate, and the ejection stability. Is good.

<< Colorant >>
There is no restriction | limiting in particular as said coloring agent, According to the objective, it can select suitably, For example, a pigment, dye, etc. are mentioned. Among these, a pigment is preferable. Examples of the pigment include inorganic pigments and organic pigments.

  As the inorganic pigment, for example, in addition to titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, and chrome yellow, it is manufactured by a known method such as a contact method, a furnace method, or a thermal method. And carbon black. These may be used individually by 1 type and may use 2 or more types together.

Examples of the organic pigment include azo pigments (for example, azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments, etc.), 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 (eg basic dye chelates, acidic dye chelates), nitro pigments, nitroso pigments, aniline black, etc. Is mentioned. These may be used individually by 1 type and may use 2 or more types together.
In addition, resin hollow particles and inorganic hollow particles can also be used.
Among these pigments, those having high affinity with an organic solvent are preferably used.

Specific examples of the pigment include black for carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, or copper, iron (C.I. Pigment black 11), metals such as titanium oxide, and organic pigments such as aniline black (CI pigment black 1). These may be used alone or in combination of two or more.
For color, for example, 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; 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, 185, 190, 193, 209, 219; 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 (phthalocyanine blue), 16, 17: 1, 56, 60, 63; I. Pigment green 1, 4, 7, 8, 10, 17, 18, 36, and the like. These may be used individually by 1 type and may use 2 or more types together.

  The colorant is preferably water-dispersible, and a polymer emulsion containing a pigment in polymer particles can be used. The polymer emulsion is one in which a pigment is contained in the polymer particle, in which a pigment is encapsulated in the polymer particle, or in which a pigment is adsorbed on the surface of the polymer particle. In this case, it is not necessary for all the pigments to be encapsulated or adsorbed, and the pigments may be dispersed in the emulsion as long as the effects of the present invention are not impaired.

Examples of the polymer emulsion formed by the polymer particles include a vinyl polymer, a polyester polymer, and a polyurethane polymer. Among these, vinyl polymers and polyester polymers are preferable.
As said polymer, the polymer currently disclosed by Unexamined-Japanese-Patent No. 2000-53897 and Unexamined-Japanese-Patent No. 2001-139849 can be used, for example.
When the polymer emulsion is used, a general organic pigment or a composite pigment obtained by coating inorganic pigment particles with an organic pigment or carbon black can be preferably used.

  The composite pigment can be produced by a method of depositing an organic pigment in the presence of inorganic pigment particles, a mechanochemical method of mechanically mixing and grinding an inorganic pigment and an organic pigment, or the like. Further, if necessary, an adhesive layer between the inorganic pigment and the organic pigment can be improved by providing a layer of an organosilane compound formed from polysiloxane and alkylsilane between the inorganic pigment and the organic pigment.

The mass ratio between the inorganic pigment particles and the organic pigment or the carbon black is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 3: 1 to 1: 3, and 3 to 2-1. : 2 is more preferable.
When the ratio of the organic pigment or the carbon black is small, color developability and coloring power may be lowered, and when the ratio of the organic pigment or the carbon black is increased, transparency and color tone may be deteriorated.

A commercial product can be used as the composite pigment in which the inorganic pigment particles are coated with the organic pigment or the carbon black. Examples of the commercially available product include silica / carbon black composite material, silica / phthalocyanine PB15: 3 composite material, silica / disazo yellow composite material, silica / quinacridone PR122 composite material (manufactured by Toda Kogyo Co., Ltd.) and the like. .
For example, when inorganic pigment particles having a primary average particle diameter of 20 nm are coated with an equal amount of organic pigment, the primary average particle diameter of the composite pigment is about 25 nm. If this can be dispersed to primary particles using an appropriate dispersant, a very fine pigment-dispersed ink having a primary average particle diameter of about 25 nm can be produced.

  When preparing the pigment-dispersed ink, not only the organic pigment on the surface contributes to the dispersion, but also the properties of the inorganic pigment at the center through the thin layer of the organic pigment having a thickness of 5 nm also appear, so both are dispersed simultaneously. The selection of a pigment dispersant that can be stabilized is important.

Another method for making the colorant water-dispersible is to treat the pigment with a surface.
The pigment is preferably a pigment oxidized using an oxidizing agent in order to introduce an ionic group and an ionizable group to the surface from the viewpoint of the storage stability of the ink.
As such a surface-treated pigment, for example, an ionic one is preferable, and an anionic one is preferable.

Examples of the anionic functional groups, for _{example, -COOM, -SO 3 M, -PO} 3 HM, -PO 3 M 2, -CONM 2, -SO 3 NM 2, -NH-C 6 H 4 -COOM, _{-NH-C 6 H 4 -SO 3} M, -NH-C 6 H 4 -PO 3 HM, -NH-C 6 H 4 -PO 3 M 2, -NH-C 6 H 4 -CONM 2 and, - containing at least one element selected from _{NH-C 6 H- 4 SO 3} NM 2, and is preferably the counter ion M is a water-dispersible pigment is a quaternary ammonium ion.
The surface-treated pigment preferably exhibits water dispersibility even in the absence of a dispersant, and is generally referred to as a “self-dispersing pigment”.

  The anionic functional group is preferably carboxylic acid and P-aminobenzoic acid. Examples of the anionic functional group include Japanese Patent No. 4697757, Japanese Patent Application Publication No. 2003-513137, International Publication No. 97/48769, Japanese Patent Application Laid-Open No. 10-110129, Japanese Patent Application Laid-Open No. 11-246807, Japanese Patent Application Laid-Open No. The pigment particles can be bonded to the surface of the pigment particles according to the methods described in JP-A-11-57458, JP-A-11-189739, JP-A-11-323232, JP-A2000-265094, and the like.

  Examples of the quaternary ammonium ion include tetramethylammonium ion, tetraethylammonium ion, tetrapropylammonium ion, tetrabutylammonium ion, tetrapentylammonium ion, benzyltriethylammonium ion, benzyltriethylammonium ion, and tetrahexylammonium ion. Can be mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, tetraethylammonium ion, tetrabutylammonium ion, and benzyltrimethylammonium ion are preferable, and tetrabutylammonium ion is more preferable.

  When the pigment has the anionic functional group and the quaternary ammonium ion, a water-dispersible pigment can be obtained. The water-dispersible pigment can exhibit affinity among water-rich inks and organic solvent-rich inks from which water has evaporated, and can maintain a stable dispersibility.

When the BET specific surface area is measured using a method of adsorbing nitrogen, the pigment has a wide range of BET specific surface areas depending on the desired properties of the pigment.
The BET specific surface area of the pigment is preferably 10 m ² / g or more and 1,500 m ² / g or less, more preferably 20 m ² / g or more and 600 m ² / g or less, and further preferably 50 m ² / g or more and 300 m ² / g or less. .
If the BET specific surface area is not easy to make the desired application, the pigment is typically reduced in size or milled (eg, ball milling, or jet milling) to make the pigment a relatively small particle size. Or sonication).

The volume average particle diameter (D ₅₀ ) of the colorant is preferably 10 nm or more and 200 nm or less in the ink. The volume average particle diameter of the colorant can be measured by a dynamic light scattering method (for example, Microtrac UPA-150, manufactured by Nikkiso Co., Ltd.) in an environment of 23 ° C. and 55% RH.

  The content of the colorant is not particularly limited and may be appropriately selected depending on the intended purpose. It is preferably 1% by mass or more and 15% by mass or less, and preferably 2% by mass or more and 10% by mass or less based on the total amount of the ink. Is more preferable. When the content is 1% by mass or more, glossiness and image density are good, and when the content is 15% by mass or less, ink discharge properties are good, which is preferable in terms of nozzle maintenance. Economically preferable.

<< Water >>
As said water, pure water, such as ion-exchange water, ultrafiltration water, reverse osmosis water, distilled water, or ultrapure water can be used, for example.
The content of the water in the ink is not particularly limited and can be appropriately selected depending on the purpose.

<< Other ingredients >>
The other components are not particularly limited and can be appropriately selected according to the purpose. For example, surfactants, penetrants, pH adjusters, antiseptic / antifungal agents, chelating reagents, rust preventives, and antioxidants. Agents, ultraviolet absorbers, oxygen absorbers, light stabilizers, antifoaming agents and the like.

-Surfactant-
As the surfactant, those having low surface tension, low penetrability, and high leveling property are preferred without impairing dispersion stability depending on the type of the colorant or the combination of the organic solvents.
The surfactant is preferably at least one selected from anionic surfactants, nonionic surfactants, silicone surfactants, and fluorine surfactants. Fluorine surfactants, silicone surfactants An activator is more preferred.

  There is no restriction | limiting in particular about the detailed content of the said fluorosurfactant, According to the objective, it can select suitably, For example, description of Paragraph [0130]-[0152] of Unexamined-Japanese-Patent No. 2015-044405 is mentioned. You can refer to it.

  There is no restriction | limiting in particular about the detailed content of the said silicone type surfactant, According to the objective, it can select suitably, For example, description of Paragraphs [0153]-[0156] of Unexamined-Japanese-Patent No. 2015-044405 is mentioned. You can refer to it.

  The content of the surfactant is preferably 0.01% by mass or more and 3.0% by mass or less, and more preferably 0.5% by mass or more and 2% by mass or less with respect to the total amount of the ink. When the content is 0.01% by mass or more and 3.0% by mass or less, the gloss is excellent and an image having a high image density is obtained.

-Penetration agent-
There is no restriction | limiting in particular as said penetrant, According to the objective, it can select suitably, For example, C8-C11 polyol compound, other polyol compounds, etc. are mentioned. Among these, those having a solubility between 0.2% by mass and 5.0% by mass in water at 25 ° C. are preferable, and 2-ethyl-1,3-hexanediol [solubility: 4.2% by mass (25% ° C.)], 2,2,4-trimethyl-1,3-pentanediol [solubility: 2.0 mass% (25 ° C.)].

  Examples of the other polyol compounds include 2-ethyl-2-methyl-1,3-propanediol, 3,3-dimethyl-1,2-butanediol, and 2,2-diethyl-1,3-propanediol. 2-methyl-2-propyl-1,3-propanediol, 2,4-dimethyl-2,4-pentanediol, 2,5-dimethyl-2,5-hexanediol, 5-hexene-1,2- Examples include diols. These may be used alone or in combination of two or more.

  Other penetrants that can be used in combination are not particularly limited as long as they can be dissolved in the ink and adjusted to desired physical properties, and can be appropriately selected according to the purpose. For example, diethylene glycol monophenyl ether, ethylene glycol Alkyl and aryl ethers of polyhydric alcohols such as monophenyl ether, ethylene glycol monoallyl ether, diethylene glycol monophenyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, tetraethylene glycol chlorophenyl ether, lower alcohols such as ethanol, etc. It is done.

  The content of the penetrant is preferably 0.1% by mass or more and 4.0% by mass or less based on the total amount of the ink. When the content is 0.1% by mass or more and 4.0% by mass or less, the drying property of the image is improved, the gloss is excellent, and an image having a high image density is obtained.

  There is no restriction | limiting in particular as a physical property of the said 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 of the ink at 25 ° C. is preferably 5 mPa · s or more and 25 mPa · s or less. By setting the ink viscosity to 5 mPa · s or more, an effect of improving image density and character quality can be obtained. Moreover, ink discharge property can be made favorable by the said ink viscosity being 25 mPa * s or less.
The viscosity can be measured at 25 ° C. using a viscometer (for example, RE-550L, manufactured by Toki Sangyo Co., Ltd.).

  The surface tension of the ink is preferably 35 mN / m or less, more preferably 32 mN / m or less at 25 ° C. When the surface tension is 35 mN / m or less, the leveling of the ink on the recording medium is appropriate, and the drying time can be shortened.

  The pH of the ink is 25 ° C., preferably 7 to 12, and more preferably 8 to 11.

<Ink production method>
In the ink, for example, the organic solvent, the colorant, and if necessary, the surfactant, the penetrant, and other components are dispersed or dissolved in water, and the polyurethane resin particles are added. It can be produced by stirring and mixing.
The dispersion or dissolution can be performed by, for example, a sand mill, a homogenizer, a ball mill, a paint shaker, an ultrasonic disperser, etc., and the stirring and mixing is performed by a stirrer using a normal stirring blade, a magnetic stirrer, a high-speed disperser, and the like. Can be used.

  There is no restriction | limiting in particular as coloring of the said ink, According to the objective, it can select suitably, For example, yellow, magenta, cyan, black etc. are mentioned. When recording is performed using an ink set in which two or more of these colorings are used in combination, a multicolor image can be formed. When recording is performed using an ink set in which all colors are combined, a full color image is formed. be able to.

  The method of using the ink is not limited to the ink jet recording method, and can be used widely. 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.

There is no restriction | limiting in particular as a use of the said ink, According to the objective, it can select suitably, For example, it can be applied to printed matter, a coating material, a coating material, the use for foundation | substrates, etc. Furthermore, it can be used not only to form two-dimensional characters and images using ink, but also as a three-dimensional modeling material for forming a three-dimensional three-dimensional image (three-dimensional modeled object).
A known three-dimensional modeling apparatus for modeling a three-dimensional model can be used, and is not particularly limited. For example, a three-dimensional modeling apparatus including an ink storage unit, a supply unit, a discharge unit, a drying unit, or the like is used. be able to. The three-dimensional structure includes a three-dimensional structure obtained by repeatedly applying ink. Further, a molded product obtained by processing a structure provided with ink on a substrate such as a recording medium is also included. The molded product is obtained by subjecting a recorded material or a structure formed in a sheet shape or a film shape to a molding process such as heat stretching or punching, for example, an automobile, an OA device, an electric -It is suitably used for applications in which surfaces are decorated after decorating, such as meters for electronic devices, cameras, etc., and panels for operation units.

<Ink container>
The ink container used in the present invention contains the ink in the set of the ink of the present invention and the recording medium in the container, and may be provided with other members appropriately selected as necessary.
There is no restriction | limiting in particular as said container, The shape, a structure, a magnitude | size, a material, etc. can be suitably selected according to the objective, For example, it has an ink bag etc. which were formed with the aluminum laminate film, the resin film, etc. A thing etc. are mentioned suitably.

  Hereinafter, an embodiment of the ink container will be described with reference to FIGS. 2 is an explanatory perspective view of the appearance of the ink container, FIG. 3 is an explanatory perspective view of the ink supply port portion of the ink container before the cap member is mounted, and FIG. 4 is an exploded perspective view of the ink supply port portion. .

The ink container 10 has an ink container 11 for containing ink inside, and the ink container 11 is provided with an ink supply port 30 having an ink supply port 20 for supplying ink to the outside. A cap member 40 that covers the ink supply port 30 is provided.
The ink supply port 30 includes a port member 31 fixed to the ink storage unit 11, a rotation regulating member 32 provided in the opening 31a of the port member 31 and provided with the ink supply port 20, and the A fixing member 33 for fixing the rotation restricting member 32 is provided in the opening 31 a of the mouth member 31 of the ink containing portion 11, and the cap member 40 is attached to the fixing member 33.

  The ink supply port 20 provided in the rotation restricting member 32 communicates with an ink storage member that stores ink stored in the ink storage portion 11 via a tube or the like. Here, the ink supply port portion 30 is configured by combining the port member 31, the rotation regulating member 32, and the fixing member 33, but the port member 31 and the rotation regulating member 32 are combined. In addition, the fixing member 33 can be integrally molded to be a single component, or can be further integrally molded with the ink containing portion 11.

(Inkjet recording method and inkjet recording apparatus)
The ink jet recording apparatus of the present invention has ink flying means, and further has other means appropriately selected as necessary.
The ink jet recording method of the present invention includes an ink flying step, and further includes other steps appropriately selected as necessary.
The ink jet recording method of the present invention can be preferably carried out by the ink jet recording apparatus of the present invention, and the ink flying step can be suitably carried out by the ink flying means. The other steps can be suitably performed by the other means.

<Ink flying process and ink flying means>
In the ink flying step, a stimulus is applied to the ink in the ink and recording medium set of the present invention, and the ink is ejected to form an image on the recording medium in the ink and recording medium set of the present invention. And can be carried out by ink flying means.
There is no restriction | limiting in particular as said ink flying means, According to the objective, it can select suitably, For example, an inkjet head etc. are mentioned.

  As the ink jet head, a piezoelectric element is used as a pressure generating means for pressurizing ink in the ink flow path, and a diaphragm that forms the wall surface of the ink flow path is deformed to change the volume in the ink flow path to eject ink droplets. A so-called piezo type (see Japanese Patent Laid-Open No. 2-51734), or a so-called thermal type that generates bubbles by heating ink in an ink flow path using a heating resistor (Japanese Patent Laid-Open No. 61-59911). The volume of the ink flow path is changed by disposing the diaphragm and the electrode that form the wall surface of the ink flow path to face each other and deforming the vibration plate by an electrostatic force generated between the vibration plate and the electrode. And an electrostatic type that discharges ink droplets (see JP-A-6-71882).

  The stimulus can be generated by, for example, the stimulus generating means, and the stimulus is not particularly limited and can be appropriately selected according to the purpose. For example, heat (temperature), pressure, vibration, light Etc. These may be used individually by 1 type and may use 2 or more types together. Among these, heat and pressure are preferable.

  There is no particular limitation on the mode of the ink flying, and it varies depending on the type of the stimulus. For example, when the stimulus is “heat”, the ink corresponding to the recording signal is applied to the ink in the inkjet head. A method of applying energy using, for example, a thermal head, generating bubbles in the ink by the thermal energy, and ejecting and ejecting the ink as droplets from the nozzle holes of the inkjet head by the pressure of the bubbles, etc. Can be mentioned. Further, when the stimulus is “pressure”, for example, by applying a voltage to a piezoelectric element bonded to a position called a pressure chamber in an ink flow path in the ink jet head, the piezoelectric element is bent, and the pressure chamber For example, a method in which the volume is reduced and the ink is ejected and ejected as droplets from the nozzle holes of the inkjet head.

  The size of the ink droplets to be ejected is preferably 3 pL or more and 40 pL or less, for example, and the ejection jet speed is preferably 5 m / s or more and 20 m / s or less. The drive frequency is preferably 1 kHz or higher, and the resolution is preferably 300 dpi or higher.

<Other processes and other means>
Examples of the other processes include a heating process, a stimulus generation process, and a control process.
Examples of the other means include a heating means, a stimulus generating means, and a control means.

The heating step is a step of heating a recording medium on which an image is recorded, and can be performed by a heating unit.
As the heating means, many known apparatuses can be used, and examples thereof include forced air heating, radiant heating, conduction heating, high frequency drying, microwave drying, and the like. These may be used alone or in combination of two or more.
The heating temperature can be changed according to the type and amount of the water-soluble organic solvent contained in the ink and the minimum film-forming temperature of the resin emulsion to be added, and further according to the type of recording medium to be printed. Can also be changed.
The heating temperature is preferably high in terms of drying property and film forming temperature, more preferably 40 ° C. or more and 120 ° C. or less, and further preferably 50 ° C. or more and 90 ° C. or less. When the heating temperature is 40 ° C. or higher and 120 ° C. or lower, it is possible to suppress the occurrence of non-ejection due to warming of the ink head.

Examples of the stimulus generating means include a heating device, a pressurizing device, a piezoelectric element, a vibration generating device, an ultrasonic oscillator, a light, and the like. Specifically, a piezoelectric actuator such as a piezoelectric element, a heating resistor, etc. Examples include a thermal actuator that uses a phase change caused by film boiling of a liquid using an electrothermal transducer, a shape memory alloy actuator that uses a metal phase change caused by a temperature change, and an electrostatic actuator that uses an electrostatic force.
The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.

Here, an example of the ink jet recording apparatus of the present invention will be described with reference to the drawings.
FIG. 5 is a schematic view showing an example of the ink jet recording apparatus of the present invention. The ink jet recording apparatus 300 in FIG. 5 includes a recording medium transport unit 301, a preprocessing step unit 302 for applying a pretreatment liquid to the recording medium 203, an image forming step unit 304, and a recording unit after the image forming step. And a post-processing section 305 that applies a post-processing liquid to the medium. In the present invention, the pre-processing step unit 302 and the post-processing step unit 305 are not necessarily provided.

  The recording medium conveyance unit 301 includes a paper feeding device 307, a plurality of conveyance rollers, and a winding device 308. 5 is a continuous paper (roll paper) wound in a roll shape. The recording medium 203 is unwound from a paper feeding device by a transport roller, and is transported on a platen to be wound up. It is wound up by the device 308.

  The recording medium 203 conveyed from the recording medium conveying unit 301 is applied with a pretreatment liquid in the pretreatment process unit 302 of FIG. In the inkjet, when an image is formed on a recording medium other than the dedicated inkjet paper, quality problems such as bleeding, density, color tone, and show-through, and problems related to image fastness such as water resistance and weather resistance occur. As a means for solving this problem, a technique for improving image quality by applying a pretreatment liquid having a function of aggregating ink before forming an image on a recording medium is performed.

  The pretreatment process may be any coating method in which the above pretreatment liquid is uniformly applied to the surface of the recording medium, and is not particularly limited. Examples of such coating methods include blade coating, gravure coating, gravure offset coating, bar coating, roll coating, knife coating, air knife coating, comma coating, U comma coating, and AKKU coating. , Smoothing coating method, micro gravure coating method, reverse roll coating method, 4 to 5 roll coating method, dip coating method, curtain coating method, slide coating method, die coating method and the like.

FIG. 6 is a schematic diagram of the pretreatment process unit 302 in the present embodiment. In this embodiment, the roll coating method will be described, but another pretreatment liquid coating method may be used.
As shown in FIG. 6, the recording medium 203 such as continuous paper is conveyed into the pretreatment liquid coating apparatus 204 by the conveyance roller 201. The pretreatment liquid application device 204 stores a pretreatment liquid 205, and the pretreatment liquid 205 is transferred to the roller surface of the application roller 208 by a stirring / supply roller 206 and a transfer / thinning roller 207 in a thin film shape. .
Then, the application roller 208 rotates while being pressed against the rotating platen roller 202, and the recording medium 203 passes between them to apply the pretreatment liquid 205 on the surface.

The platen roller 202 can adjust the nip pressure when applying the pretreatment liquid by the pressure adjusting device 209. By changing the nip pressure, the coating amount of the pretreatment liquid 205 can be changed.
The application amount can also be adjusted by changing the rotation speeds of the application roller 208 and the platen roller 202. The application roller 208 and the platen roller 202 are driven by a power source such as a drive motor, and the amount of application can be adjusted by changing the rotational speed by changing the energy of the power source.

  In this way, the method of applying the pretreatment liquid 205 for improving the image quality to the recording area of the recording medium 203 with the application roller 208 is performed by spraying the processing agent liquid onto the recording medium using the ejection head. Compared with the method to be performed, the pretreatment liquid 205 having a relatively high viscosity can be applied thinly on the recording medium 203, and the image bleeding and the like can be further reduced.

  As shown in FIG. 5, the pretreatment section may be provided with a pretreatment and drying section 303 after the coating process. The pre-processing and post-drying unit includes, for example, heat rollers 311 and 312 as shown in FIG. According to this apparatus, the continuous paper coated with the pretreatment liquid is conveyed to the heat roller by the conveyance roller. The heat roller is heated to a high temperature of 50 ° C. to 100 ° C., and the continuous paper coated with the pretreatment liquid evaporates and dries due to contact heat transfer from the heat roller. The drying means is not limited to this, and an infrared drying device, a microwave drying device, a hot air device, etc. can be applied. Instead of using a single device, for example, a combination of a heat roller and a hot air device is used. May be. It is also effective to heat the recording medium before applying the pretreatment liquid (addition of a preheating step).

On the recording medium after the preprocessing process, an image corresponding to the image data is formed in the image forming process section.
The image forming process unit 304 is a full-line head, and four recording heads that can handle black (K), cyan (C), magenta (M), and yellow (Y) from the upstream side in the recording medium conveyance direction. 304K, 304C, 304M, and 304Y are arranged. For example, as shown in FIG. 7, the black (K) recording head 304K has four head units 304K-1, 304K-2, 304K-3, and 304K-4 arranged in a staggered manner in a direction perpendicular to the transport direction. This ensures the print area width.
FIG. 8 is an enlarged view of the head unit 304K-1. As shown in FIG. 8, a large number of print nozzles 310 are arranged on the nozzle surface 309 of 304K-1 along the longitudinal direction of the head unit 304K-1, thereby constituting a nozzle row. In this embodiment, the number of nozzle rows is one, but a plurality of rows can be provided. The other recording heads 304C, 304M, and 304Y have the same configuration, and the four recording heads 304K, 304C, 304M, and 304Y are arranged in the transport direction while maintaining the same pitch. As a result, it is possible to form an image over the entire print area width in a single recording operation.
The type of ink is not limited to K, C, M, and Y, and photo ink such as light cyan can be applied.

The post-processing liquid is applied to the recording medium after the image forming process by a post-processing process unit 305. This post-treatment liquid contains a component capable of forming a transparent protective layer on the recording medium.
In the post-processing step in the present embodiment, it may be applied over the entire image surface of the recording medium, or may be applied only to a specific portion of the image surface. More preferably, it is desirable to change the coating amount and the coating method according to the printing conditions (type of recording medium, amount of ink ejected onto paper, etc.).

The method for applying the post-treatment liquid is not particularly limited, and various methods are appropriately selected depending on the type of the post-treatment liquid. The same method as the method for applying the pre-treatment liquid or the method for causing the ink to fly is used. Any of the same methods can be suitably used. Among these, the method similar to the method of flying ink is particularly preferable from the viewpoint of the apparatus configuration and the storage stability of the post-treatment liquid. By using this method, it is possible to apply a necessary amount to an arbitrary location on the image. In this post-process includes the steps of dry coverage in the image formed surface to form a protective layer by applying a post-treatment liquid containing a transparent resin so as to 0.5g ^/ m ² ~10g / m 2 is there.

Dry coverage of the post-treatment solution is preferably ^{0.5g / m 2 ~10g / m 2} , more preferably ^{2g / m 2 ~8g / m 2} . When the dry adhesion amount is 0.5 g / m ² or more, the image quality (image density, saturation, glossiness, and fixability) is good, and when it is 10 g / m ² or less, the protective layer is dried. Property is improved.

The post-processing section may be provided with a post-processing drying section 306 as shown in FIG.
The post-processing post-drying unit includes, for example, heat rollers 313 and 314 as shown in FIG. According to this apparatus, the continuous paper coated with the post-treatment liquid is conveyed to the heat roller by the conveyance roller. The heat roller is heated to a high temperature, and the continuous paper coated with the post-treatment liquid is dried due to evaporation of moisture by contact heat transfer from the heat roller. The drying means is not limited to this, and an infrared drying device, a microwave drying device, a hot air device, etc. can be applied. Instead of using a single device, for example, a combination of a heat roller and a hot air device is used. May be.
The paper after drying is taken up by the take-up device 308. If the pressure during the take-up is large, the image may be transferred to the back side. In that case, if necessary, a pre-winding drying unit 315 as shown in FIG. 5 can be provided. The above-described configuration (for example, a combination of a heat roller and a warm air device) can be applied to the drying unit.

  Although an example in which the present invention is applied to a line type ink jet recording apparatus has been described here, the present invention can also be applied to a serial type (shuttle type) ink jet recording apparatus.

(ink)
The ink of the present invention is an ink used in an ink jet recording method including an ink flying step of applying a stimulus to the ink and causing the ink to fly to record an image on a recording medium,
The ink is an ink containing an organic solvent, polyurethane resin particles, a colorant, and water,
The organic solvent contains a compound having a saturated vapor pressure at 100 ° C. of 65 mmHg or more and 400 mmHg or less,
The sensor output value at the critical image peeling point by the micro scratch method is 600 or more in a solid image in which the amount of the ink formed on the recording medium is 0.96 mg / cm ² .

(Recorded material)
The recorded matter of the present invention is a recorded matter having a recording medium and a recording layer,
The recording layer contains an organic solvent, polyurethane resin particles, and a colorant;
The organic solvent contains a compound having a saturated vapor pressure at 100 ° C. of 65 mmHg or more and 400 mmHg or less,
The recording layer has a sensor output value of 600 or more at a critical image peeling point by the micro scratch method in a solid image formed on the recording medium and having an adhesion amount of 0.96 mg / cm ² .
The recorded matter has high image quality, no bleeding, and excellent gloss, and can be suitably used for various purposes as a material on which various prints or images are recorded.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Production Example 1-1 of Resin Particles)
<Synthesis of polyurethane resin emulsion 1-1>
In a four-necked flask equipped with a nitrogen introducing tube, a cooling tube, a stirrer, and a thermocouple, 50 parts by mass of polycarbonate polyol (Duranol T5650E, manufactured by Asahi Kasei Chemicals Corporation) and 2,2-bis (hydroxymethyl) 6.46 parts by mass of propionic acid was added and mixed, heated to 40 ° C., the inside of the flask was decompressed, and dried. Subsequently, after the inside of the flask was sufficiently replaced with nitrogen gas, 88 parts by mass of dehydrated acetone, 3.41 parts by mass of triethylamine and 27.9 parts by mass of hexamethylene diisocyanate were added and stirred, and then the temperature was raised to 80 ° C. The reaction was performed over 5 hours. Thereafter, the temperature was lowered to 40 ° C., 163 parts by mass of ion exchanged water and 2.09 parts by mass of metaxylenediamine were added, and stirred for 1 hour to obtain a polyurethane resin emulsion.
It was -10 degreeC when the glass transition temperature (Tg) of the polyurethane resin particle in the obtained polyurethane resin emulsion was measured as follows.

<Measurement of glass transition temperature>
The glass transition temperature of the obtained polyurethane resin particles was determined from an endothermic chart of a differential scanning calorimeter (DSC) (Q2000, manufactured by TA Instruments Japan Co., Ltd.). That is, 5 mg to 10 mg of the dried resin particles obtained by evaporating the moisture and solvent of the resin particles and weighing them in a simple sealed pan made of aluminum were subjected to the following measurement flow.
・ First heating: 30 ° C. to 220 ° C., 5 ° C./min, hold for 1 minute after reaching 220 ° C. Cooling: Quench to −60 ° C. without temperature control, hold for 1 minute after reaching −60 ° C. ・ Second heating: − 60 ° C. to 180 ° C., 5 ° C./min In the second thermogram, the midpoint method was adopted to read the value (ASTM D3418 / 82, ASTM International), and the glass transition temperature was obtained.

Next, the polyurethane resin emulsion is mixed in a 2,000 mL stainless steel beaker made of SUS304, and stirred at 30 ° C. and 400 W for 45 minutes using an ultrasonic homogenizer (UP-400S, manufactured by Dr. Heelscher). Distributed processing was performed. Thereafter, the temperature was raised to 60 ° C., the pressure was reduced, acetone was distilled off, and the solid content concentration was adjusted to 50 mass% with ion-exchanged water. Thus, polyurethane resin emulsion 1-1 was obtained.
The volume average particle size of the obtained polyurethane resin emulsion 1-1 was 10 nm as measured as follows.

<Measurement of volume average particle diameter>
The volume average particle size of the obtained polyurethane resin emulsion 1-1 was measured with a particle size distribution measuring device (Nikkiso Co., Ltd., Nanotrac UPA-EX150).

(Production Example 1-2 of Resin Particles)
<Synthesis of polyurethane resin emulsion 1-2>
A polyurethane resin emulsion 1-2 was prepared in the same manner as in Production Example 1-1 of the resin particle except that the dispersion treatment was stirred for 30 minutes at 30 ° C. and 400 W in Production Example 1-1 of the resin particle. Obtained.
The volume average particle size of the obtained polyurethane resin emulsion 1-2 was measured in the same manner as in Production Example 1 for resin particles, and found to be 15 nm.

(Production Example 1-3 of Resin Particles)
<Synthesis of polyurethane resin emulsion 1-3>
A polyurethane resin emulsion 1-3 was prepared in the same manner as in the resin particle production example 1-1 except that the resin particle production example 1-1 was changed to a dispersion treatment that was stirred at 30 ° C. and 400 W for 18 minutes. Obtained.
The volume average particle size of the obtained polyurethane resin emulsion 1-3 was measured in the same manner as in Production Example 1 for resin particles, and found to be 19 nm.

(Production Example 2 of Resin Particles)
<Synthesis of polyurethane resin emulsion 2>
In a four-necked flask equipped with a nitrogen introduction tube, a cooling tube, a stirrer, and a thermocouple, 50 parts by mass of polycarbonate polyol (Duranol T5651, manufactured by Asahi Kasei Chemicals Corporation) and 2,2-bis (hydroxymethyl) ) 4.35 parts by mass of propionic acid was added and mixed, heated to 40 ° C., the inside of the flask was depressurized and dried. Subsequently, after the inside of the flask was sufficiently replaced with nitrogen gas, 54 parts by mass of dehydrated acetone, 3.51 parts by mass of triethylamine, and 15.1 parts by mass of tolylene diisocyanate were added and the temperature was raised to 80 ° C. after stirring. The reaction was performed over 5 hours. Thereafter, the temperature was lowered to 40 ° C., 135 parts by mass of ion-exchanged water and 0.42 parts by mass of metaxylenediamine were added, and stirred for 1 hour to obtain a polyurethane resin emulsion.
The glass transition temperature (Tg) of the polyurethane resin particles in the obtained polyurethane resin emulsion was measured in the same manner as in Production Example 1 of the resin particles.

Next, the polyurethane resin emulsion is mixed in a 2,000 mL stainless steel beaker made of SUS304, and stirred for 30 minutes at 30 ° C. and 400 W using an ultrasonic homogenizer (UP-400S, manufactured by Dr. Heelscher). Distributed processing was performed. Thereafter, the temperature was raised to 60 ° C., the pressure was reduced, acetone was distilled off, and the solid content concentration was adjusted to 50 mass% with ion-exchanged water. Thus, polyurethane resin emulsion 2 was obtained.
The volume average particle diameter of the obtained polyurethane resin emulsion 2 was measured in the same manner as in Production Example 1 for resin particles, and found to be 15 nm.

(Production Example 3-1 of Resin Particles)
<Synthesis of polyurethane resin emulsion 3-1>
In a four-necked flask equipped with a nitrogen introduction tube, a cooling tube, a stirrer, and a thermocouple, 50 parts by mass of polyester polyol (Teslac 2477, manufactured by Hitachi Chemical Co., Ltd.) and 2,2-bis (hydroxymethyl) ) 1.77 parts by mass of propionic acid was added and mixed, heated to 40 ° C., the inside of the flask was depressurized and dried. Subsequently, after the inside of the flask was sufficiently substituted with nitrogen gas, 62 parts by mass of dehydrated acetone, 0.94 parts by mass of triethylamine, and 9.1 parts by mass of norbornenemethane diisocyanate were added, and the temperature was raised to 80 ° C. after stirring. The reaction was performed over 5 hours. Thereafter, the temperature was lowered to 40 ° C., 115 parts by mass of ion-exchanged water and 1.69 parts by mass of isophoronediamine were added, and the mixture was stirred for 1 hour to obtain a polyurethane resin emulsion.
The glass transition temperature (Tg) of the polyurethane resin particles in the obtained polyurethane resin emulsion was measured in the same manner as in Production Example 1 for resin particles, and found to be 10 ° C.

Next, the polyurethane resin emulsion is mixed in a 2,000 mL stainless steel beaker made of SUS304, and stirred at 30 ° C. and 400 W for 1 hour using an ultrasonic homogenizer (UP-400S, manufactured by Dr. Heelscher). Distributed processing was performed. Thereafter, the temperature was raised to 60 ° C., the pressure was reduced, acetone was distilled off, and the solid content concentration was adjusted to 50 mass% with ion-exchanged water. Thus, polyurethane resin emulsion 3-1 was obtained.
The volume average particle diameter of the obtained polyurethane resin emulsion 3-1 was measured in the same manner as in Production Example 1 for resin particles, and found to be 8 nm.

(Production Example 3-2 of Resin Particles)
<Synthesis of polyurethane resin emulsion 3-2>
A polyurethane resin emulsion 3-2 was prepared in the same manner as in Production Example 1-1 of the resin particle except that the dispersion treatment was stirred at 30 ° C. and 400 W for 30 minutes in Production Example 3-1 of the resin particle. Obtained.
The volume average particle size of the obtained polyurethane resin emulsion 3-2 was measured in the same manner as in Production Example 1 of the resin particles, and found to be 15 nm.

(Production Example 4 of Resin Particles)
<Synthesis of polyurethane resin emulsion 4>
In a four-necked flask equipped with a nitrogen introduction tube, a cooling tube, a stirrer, and a thermocouple, 50 parts by mass of polycarbonate polyol (reaction product of 1,6-hexanediol and dimethyl carbonate), and 2,2- 4.58 parts by mass of bis (hydroxymethyl) propionic acid was added and mixed, heated to 40 ° C., the pressure in the flask was reduced and dried. Subsequently, after the inside of the flask was sufficiently replaced with nitrogen gas, 63 parts by mass of dehydrated acetone, 3.70 parts by mass of triethylamine, and 26.6 parts by mass of hexamethylene diisocyanate were added and stirred, and the temperature was raised to 80 ° C. The reaction was performed over 5 hours. Thereafter, the temperature was lowered to 40 ° C., 158 parts by mass of ion-exchanged water and 0.48 parts by mass of dipropylene triamine were added and stirred for 1 hour to obtain a polyurethane resin emulsion.
The glass transition temperature (Tg) of the polyurethane resin particles in the obtained polyurethane resin emulsion was measured in the same manner as in Production Example 1 of the resin particles, and found to be 12 ° C.

Next, the polyurethane resin emulsion is mixed in a 2,000 mL stainless steel beaker made of SUS304, and stirred at 30 ° C. and 400 W for 45 minutes using an ultrasonic homogenizer (UP-400S, manufactured by Dr. Heelscher). Distributed processing was performed. Thereafter, the temperature was raised to 60 ° C., the pressure was reduced, acetone was distilled off, and the solid content concentration was adjusted to 50 mass% with ion-exchanged water. Thus, a polyurethane resin emulsion 4 was obtained.
The volume average particle diameter of the obtained polyurethane resin emulsion 4 was measured in the same manner as in Production Example 1 for resin particles, and found to be 10 nm.

(Production Example 5 of Resin Particles)
<Synthesis of polyurethane resin emulsion 5>
In a four-necked flask equipped with a nitrogen introduction tube, a cooling tube, a stirrer, and a thermocouple, 50 parts by mass of polyester polyol (Kurapol P-2010, manufactured by Kuraray Co., Ltd.) and 2,2-bis (hydroxymethyl) ) 1.55 parts by mass of propionic acid was added and mixed, heated to 40 ° C., the inside of the flask was depressurized and dried. Subsequently, after the inside of the flask was sufficiently replaced with nitrogen gas, 46 parts by mass of dehydrated acetone, 0.99 parts by mass of triethylamine, and 9.3 parts by mass of isophorone diisocyanate were added and stirred, and then the temperature was raised to 80 ° C. The reaction was carried out over 5 hours. Thereafter, the temperature was lowered to 40 ° C., 115 parts by mass of ion-exchanged water and 0.62 parts by mass of isophoronediamine were added and stirred for 1 hour to obtain a polyurethane resin emulsion.
The glass transition temperature (Tg) of the polyurethane resin particles in the obtained polyurethane resin emulsion was measured in the same manner as in Production Example 1 of the resin particles, and was −32 ° C.

Next, the polyurethane resin emulsion is mixed in a 2,000 mL stainless steel beaker made of SUS304, and stirred at 30 ° C. and 400 W for 45 minutes using an ultrasonic homogenizer (UP-400S, manufactured by Dr. Heelscher). Distributed processing was performed. Thereafter, the temperature was raised to 60 ° C., the pressure was reduced, acetone was distilled off, and the solid content concentration was adjusted to 50 mass% with ion-exchanged water. Thus, a polyurethane resin emulsion 5 was obtained.
The volume average particle diameter of the obtained polyurethane resin emulsion 5 was measured in the same manner as in Production Example 1 for resin particles, and found to be 10 nm.

(Production Example 6-1 of Resin Particles)
<Synthesis of polyurethane resin emulsion 6-1>
In a four-necked flask equipped with a nitrogen introducing tube, a cooling tube, a stirrer, and a thermocouple, 50 parts by mass of polycarbonate polyol (Duranol T5651, manufactured by Asahi Kasei Chemicals) and 2,2-bis (hydroxymethyl) propion 3.07 parts by mass of acid was added and mixed, heated to 40 ° C., the pressure in the flask was reduced and dried. Subsequently, after the inside of the flask was sufficiently replaced with nitrogen gas, 50 parts by mass of dehydrated acetone, 1.62 parts by mass of triethylamine, and 13.1 parts by mass of tolylene diisocyanate were added and stirred, and then the temperature was raised to 80 ° C. The reaction was performed over 5 hours. Thereafter, the temperature was lowered to 40 ° C., 126 parts by mass of ion-exchanged water and 0.29 parts by mass of dipropylene triamine were added and stirred for 1 hour to obtain a polyurethane resin emulsion.
When the glass transition temperature (Tg) of the polyurethane resin particles in the obtained polyurethane resin emulsion was measured in the same manner as in Production Example 1 of the resin particles, it was −20 ° C.

Next, the polyurethane resin emulsion is mixed in a 2,000 mL stainless steel beaker made of SUS304, and stirred at 30 ° C. and 400 W for 1 hour using an ultrasonic homogenizer (UP-400S, manufactured by Dr. Heelscher). Distributed processing was performed. Thereafter, the temperature was raised to 60 ° C., the pressure was reduced, acetone was distilled off, and the solid content concentration was adjusted to 50 mass% with ion-exchanged water. Thus, polyurethane resin emulsion 6-1 was obtained.
The volume average particle size of the obtained polyurethane resin emulsion 6-1 was measured in the same manner as in Production Example 1 for resin particles, and found to be 8 nm.

(Production Example 6-2 of Resin Particles)
<Synthesis of polyurethane resin emulsion 6-2>
In the resin particle production example 6-1, a polyurethane resin emulsion 6-2 was prepared in the same manner as in the resin particle production example 1-1 except that the dispersion treatment was stirred at 30 ° C. and 400 W for 10 minutes. Obtained.
The volume average particle size of the obtained polyurethane resin emulsion 6-2 was measured in the same manner as in Production Example 1 for resin particles, and found to be 22 nm.

(Production Example 7 of Resin Particles)
<Synthesis of polyurethane resin emulsion 7>
In a four-necked flask equipped with a nitrogen introduction tube, a cooling tube, a stirrer, and a thermocouple, 50 parts by mass of polyester polyol (Teslac 2477, manufactured by Hitachi Chemical Co., Ltd.) and 2,2-bis (hydroxymethyl) ) 1.26 parts by mass of propionic acid was added and mixed, heated to 40 ° C., the inside of the flask was depressurized and dried. Subsequently, after the inside of the flask was sufficiently replaced with nitrogen gas, 45 parts by mass of dehydrated acetone, 0.80 parts by mass of triethylamine, and 8.3 parts by mass of norbornenemethane diisocyanate were added and the temperature was raised to 80 ° C. after stirring. The reaction was performed over 5 hours. Thereafter, the temperature was lowered to 40 ° C., 112 parts by mass of ion-exchanged water and 0.21 part by mass of diethylenetriamine were added and stirred for 1 hour to obtain a polyurethane resin emulsion.
The glass transition temperature (Tg) of the polyurethane resin particles in the obtained polyurethane resin emulsion was measured in the same manner as in Production Example 1 of the resin particles.

Next, the polyurethane resin emulsion is mixed in a 2,000 mL stainless steel beaker made of SUS304, and stirred at 30 ° C. and 400 W for 5 hours using an ultrasonic homogenizer (UP-400S, manufactured by Dr. Heelscher). Distributed processing was performed. Thereafter, the temperature was raised to 60 ° C., the pressure was reduced, acetone was distilled off, and the solid content concentration was adjusted to 50 mass% with ion-exchanged water. Thus, a polyurethane resin emulsion 7 was obtained.
The volume average particle size of the obtained polyurethane resin emulsion 7 was measured in the same manner as in Production Example 1 for resin particles, and found to be 6 nm.

(Preparation Example 1 of Pigment Dispersion)
<Preparation of surface modified black pigment dispersion>
1 kg of SENSIJET Black SDP2000 dispersion (manufactured by Sensient Technologies, carbon black, pigment solid content concentration 14.5% by mass) was acidified with an aqueous solution of 0.1N HCl. Subsequently, the surface-modified black pigment emulsion was obtained after 30 minutes by adjusting the pH to 9 with a 10 mass% tetrabutylammonium hydroxide solution (methanol solution).
The resulting surface-modified black pigment dispersion contains a pigment combined with at least one carboxylic acid group, sulfonic acid group, carboxylic acid tetrabutylammonium salt, or sulfonic acid tetrabutylammonium salt.
The surface-modified black pigment dispersion and ion-exchanged high-purity water were subjected to ultrafiltration using a dialysis membrane, and further subjected to ultrasonic dispersion to concentrate the pigment solid content concentration to 25% by mass.
The volume average particle size of the obtained surface modified black pigment dispersion _{(D 50)} particle size distribution analyzer (Nikkiso Co., NANOTRAC UPA-EX150) was measured by, was 120 nm.

(Preparation Example 2 of Pigment Dispersion)
<Preparation of surface-modified magenta pigment dispersion>
1 kg of SMART Magenta 3122BA dispersion (Pigment Red 122 surface treatment emulsion, pigment solid content concentration 14.5% by mass, manufactured by Sensitive Technologies) was acidified with an aqueous solution of 0.1N HCl. Subsequently, the surface-modified magenta pigment dispersion was obtained after 30 minutes by adjusting the pH to 9 with a 10 mass% tetraethylammonium hydroxide aqueous solution.
The resulting surface-modified magenta pigment dispersion contains a pigment combined with at least one aminobenzoic acid group, or tetraethylammonium aminobenzoate salt.
The surface-modified magenta pigment dispersion and ion-exchange high purity water were subjected to ultrafiltration using a dialysis membrane, and further subjected to ultrasonic dispersion to concentrate the pigment solid content concentration to 25% by mass.
The volume average particle diameter (D ₅₀ ) of the obtained surface-modified magenta pigment dispersion was measured in the same manner as in Preparation Example 1 for the pigment dispersion, and found to be 104 nm.

(Preparation Example 3 of Pigment Dispersion)
<Preparation of surface-modified cyan pigment dispersion>
1 kg of SMART Cyan 3154BA dispersion (Pigment Blue 15: 4 surface treatment emulsion, pigment solid content concentration 14.5% by mass, manufactured by Sensitive Technologies) was acidified with an aqueous solution of 0.1N HCl. Subsequently, the surface-modified cyan pigment emulsion was obtained after 30 minutes by adjusting the pH to 9 with a 40 mass% benzyltrimethylammonium hydroxide solution (methanol solution).
The resulting surface-modified cyan pigment emulsion contains a pigment bound to at least one aminobenzoic acid group, or benzyltrimethylammonium salt of aminobenzoic acid. The surface-modified cyan pigment emulsion and ion-exchanged high-purity water were subjected to ultrafiltration using a dialysis membrane, and further subjected to ultrasonic dispersion to concentrate the pigment solid content concentration to 25% by mass.
The volume average particle diameter (D ₅₀ ) of the obtained surface-modified cyan pigment emulsion was measured in the same manner as in Preparation Example 1 for the pigment dispersion, and found to be 116 nm.

(Preparation Example 4 of Pigment Dispersion)
<Preparation of surface modified yellow pigment dispersion>
1 kg of SMART Yellow 3074BA dispersion (Pigment Yellow 74 surface treatment emulsion, pigment solid content concentration 14.5% by mass, manufactured by Sensitive Technologies) was acidified with 0.1N HCl aqueous solution. Subsequently, the surface-modified yellow pigment dispersion was obtained after 30 minutes by adjusting the pH to 9 with a 10 mass% tetrabutylammonium hydroxide solution (methanol solution).
The resulting surface-modified yellow pigment dispersion contains a pigment bound to at least one aminobenzoic acid group or aminobutyl tetrabutylammonium salt.
The obtained surface-modified yellow pigment dispersion and ion-exchanged high-purity water were subjected to ultrafiltration using a dialysis membrane, and further subjected to ultrasonic dispersion to concentrate the pigment solid content concentration to 25% by mass.
The volume average particle diameter (D ₅₀ ) of the obtained surface-modified cyan pigment dispersion was measured in the same manner as in Preparation Example 1 for the pigment dispersion, and found to be 145 nm.

(Examples 1-18 and Comparative Examples 1-7)
Based on the composition and content shown in Table 2 to Table 5 below, an organic solvent, a penetrating agent, a surfactant, an antifungal agent, an antifoaming agent, a pH adjuster, and water are mixed and stirred uniformly for 1 hour. Mixed. The pigment dispersion was added to this mixed solution and stirred for 1 hour. Next, the resin emulsion was added, and the ink obtained by further stirring for 1 hour was subjected to pressure filtration with a polyvinylidene fluoride membrane filter having an average pore size of 0.8 μm to remove coarse particles and dust. As described above, inks of Examples 1 to 18 and Comparative Examples 1 to 7 and a recording medium set were prepared.

The detail of each component of Table 2 to Table 5 is as follows.
-Aquabrid UX-100: Acrylic emulsion (Daicel Finechem Co., Ltd., glass transition temperature (Tg) -10 ° C., solid content concentration 50 mass%), the acrylic emulsion was dispersed by an ultrasonic homogenizer, and volume averaged What adjusted the particle size to 10 nm was used.
Emulsion Elitel KZT-8904: Polyester emulsion (manufactured by Unitika Ltd., glass transition temperature (Tg) 8 ° C., solid content concentration 30% by mass), the polyester emulsion is dispersed by an ultrasonic homogenizer, and volume-average particles What adjusted the diameter to 10 nm was used.
・ Zonyl FS-300: Polyoxyethylene perfluoroalkyl ether (manufactured by DuPont Co., Ltd., component concentration: 40% by mass)
Softanol EP-7025: polyoxyalkylene alkyl ether (manufactured by Nippon Shokubai Co., Ltd., component concentration: 100% by mass)
-Unidyne DSN-403N: perfluoroalkyl polyethylene oxide addition product (manufactured by Daikin Industries, Ltd., component concentration: 100% by mass)
Proxel GXL: Antifungal agent mainly composed of 1,2-benzisothiazolin-3-one (manufactured by Avicia, component concentration of 20% by mass, containing dipropylene glycol)
KM-72F: self-emulsifying silicone defoamer (manufactured by Shin-Etsu Silicone Co., Ltd., component concentration: 100% by mass)

  Next, Table 6 below summarizes the contents of the organic solvents used in Examples and Comparative Examples.

* Mass ratio (C / A) is a mass ratio between the content A (mass%) of polyurethane resin particles and the content C (mass%) of a compound having a saturated vapor pressure of 65 mmHg or more and 400 mmHg or less at 100 ° C. .

The contents of the abbreviations for organic solvents in Table 6 are as follows.
PNP: propylene glycol monopropyl ether (saturated vapor pressure at 100 ° C .: 105 mmHg)
PNM: Propylene glycol monomethyl ether (saturated vapor pressure at 100 ° C .: 380 mmHg)
3-MB: 3-methoxybutanol (saturated vapor pressure at 100 ° C .: 92 mmHg)
ENB: ethylene glycol monobutyl ether (saturated vapor pressure at 100 ° C .: 68 mmHg)
MMB: 3-methyl-3-methoxybutanol (saturated vapor pressure at 100 ° C .: 61 mmHg)
MBD: 3-methyl-1,3-butanediol (saturated vapor pressure at 100 ° C .: 15.1 mmHg)
EHO: 3-ethyl-3-hydroxymethyloxetane (saturated vapor pressure at 100 ° C .: 13.5 mmHg)
1,3-BD: 1,3-butanediol (saturated vapor pressure at 100 ° C .: 11.8 mmHg)
1-butanol (saturated vapor pressure at 100 ° C .: 413 mmHg)

  Next, Table 7 below summarizes the contents of the resin particles used in the examples and comparative examples.

* Mass ratio (A / B) is a mass ratio of resin particle content A (mass%) and colorant content B (mass%).

  Next, various properties were evaluated as follows using each ink in the set of the prepared ink and the recording medium and a set of the ink and the recording medium obtained by combining the recording media shown below. The results are shown in Table 8.

<Measurement of sensor output value at critical image peeling point in micro scratch test method>
Each of the produced color inks was filled into an inkjet printer (IPSIO GX5500, manufactured by Ricoh Co., Ltd.). Next, a solid image was formed on coated paper (Lumi Art Gloss 130 gsm paper, manufactured by Stora Enso) as a recording medium under the conditions that the resolution was 1,200 dpi and the ink adhesion amount was 0.96 mg / cm ² . The solid image was dried for 30 seconds in a thermostatic bath set to have an internal temperature of 100 ° C.
Using a micro scratch tester (CSR-2000, manufactured by Reska Co., Ltd.), the sensor output value at the critical image peeling point was determined for the solid image by the micro scratch method under the following conditions (JIS R3255-1997 “Glass”). Conforms to the “Method for Adhesion Test of Thin Films with a Substrate”). Note that the number of times of measurement is 1, and the measurement position is the center of the solid image.
-Measurement conditions-
・ Scratch speed: 20 μm / s
・ Measurement time: 30 seconds ・ Load at the end of measurement: 10 mN
・ Amplitude level: 100 μm
・ Excitation frequency: 45Hz
・ Data sampling: 3735Hz
・ Spring constant: 100 g / mm
-Stylus (diamond needle) diameter: 5 μm

<Measurement of arithmetic average roughness Ra of image>
Each prepared ink was filled in an inkjet printer (IPSIO GX5500, manufactured by Ricoh Co., Ltd.). Next, a solid image was formed on coated paper (Lumi Art Gloss 130 gsm paper, manufactured by Stora Enso) as a recording medium under the condition that the ink adhesion amount was 0.96 mg / cm ² at a resolution of 1,200 dpi. Thereafter, the solid image was dried for 30 seconds in a thermostatic bath set to have an internal temperature of 100 ° C. Next, using a laser microscope (VK-850, manufactured by Keyence Corporation), the arithmetic roughness of the solid image was obtained under a measurement pitch of 0.1 μm. An area of 0.4 mm was scanned 10 times in the vertical direction, and the average value was defined as the arithmetic average roughness Ra.

<Abrasion resistance>
Each prepared ink was filled in an inkjet printer (IPSIO GX5500, manufactured by Ricoh Co., Ltd.). Next, coated paper (Lumi Art Gloss 130 gsm paper, manufactured by Stora Enso) as a recording medium was set. Next, a solid image was formed with a resolution of 1,200 dpi. Thereafter, the solid image was dried for 30 seconds in a thermostatic bath set to have an internal temperature of 100 ° C. After drying, the solid image is rubbed 20 times with a white paper portion of the coated paper cut into a 1.2 cm square, and ink adhesion stains on the white paper portion of the coated type are reflected by a reflective color spectrocolorimetric densitometer (X-Rite). The measurement was performed using The transfer density obtained by subtracting the background color of the rubbed coated paper was determined, and the scratch resistance was evaluated based on the following criteria. Note that the allowable range is up to Δ.
[Evaluation criteria]
A: Transfer density is less than 0.13 B: Transfer density is 0.13 or more and less than 0.17 Δ: Transfer density is 0.17 or more and less than 0.20 ×: Transfer density is 0.20 or more

<Image density>
Each prepared ink was filled in an inkjet printer (IPSIO GX5500, manufactured by Ricoh Co., Ltd.). Next, set a coated paper (Lumi Art Gloss 130 gsm paper, made by Stora Enso) as a recording medium, and use a 64-point character “square” (characters with filled squares) created with Microsoft Word 2000 (made by Microsoft). After printing the described chart at a resolution of 1,200 dpi, the printed part was dried for 30 seconds in a thermostatic bath set so that the internal temperature was 100 ° C. About the printed matter after drying, the image density was measured using a reflection type color spectrocolorimetric densitometer (manufactured by X-Rite) and evaluated based on the following criteria. Note that the allowable range is up to Δ.
[Evaluation criteria]
◎: Black: 1.6 or more Yellow: 1.1 or more Magenta: 1.4 or more Cyan: 1.6 or more ○: Black: 1.3 or more, less than 1.6 Yellow: 1.0 or more, less than 1.1 Magenta: 1.1 or more and less than 1.4 Cyan: 1.3 or more and less than 1.6 Δ: Black: 1.1 or more and less than 1.3 Yellow: 0.8 or more and less than 1.0 Magenta: 0. 9 or more, less than 1.1 Cyan: 1.1 or more, less than 1.3 X: Black: less than 1.1 Yellow: less than 0.8 Magenta: less than 0.9 Cyan: less than 1.1

<Glossiness>
Each prepared ink was filled in an ink jet printer (Ricoh Co., Ltd., IPSIO GX5500). Next, a solid image with a resolution of 1,200 dpi was formed on a glossy recording medium (Ricoh Business Coat Gloss 100, background 60 ° gloss: 21, manufactured by Ricoh Co., Ltd.) as a recording medium. Thereafter, the solid image was dried for 30 seconds in a thermostatic bath set to have an internal temperature of 100 ° C.
Next, the 60 ° glossiness of the solid image was measured using a gloss meter (Atlas Co., Ltd., Micro-Gross 60 °), and based on the following criteria. The gloss was evaluated. Note that the allowable range is up to Δ.
[Evaluation criteria]
◎: 60 ° glossiness of 30% or more ○: 60 ° glossiness of 25% or more and less than 30% △: 60 ° glossiness of 20% or more and less than 25% ×: 60 ° glossiness of less than 20%

<Blocking property>
Each prepared ink was filled in an ink jet printer (Ricoh Co., Ltd., IPSIO GX5500). Next, coated paper (Lumi Art Gloss 130 gsm paper, manufactured by Stora Enso) as a recording medium was set, and a solid image was formed at a resolution of 1,200 dpi. Thereafter, the solid image was dried for 30 seconds in a thermostatic bath set to have an internal temperature of 100 ° C. Immediately after drying, the solid image was cut out and pasted with a white paper portion of the coated paper to place a weight from above so as to be 5 kgf / cm ^2, and allowed to stand at 23 ° C. in an environment of 50% RH for 24 hours. After 24 hours, the transfer state of the solid image (pigment) onto the white paper portion of the coated paper was visually observed, and the blocking property was evaluated based on the following criteria. Note that the allowable range is up to Δ.
[Evaluation criteria]
A: There is no transfer to the white paper part. ○: A part of the image is transferred to the white paper part and can be confirmed from a distance of 30 cm. Δ: A part of the image is transferred to the white paper part and the distance is 60 cm. X: Most of the image is transferred to the blank area

<Maintenance>
Each prepared ink was filled in an inkjet printer (IPSIO GX5500, manufactured by Ricoh Co., Ltd.). Next, the printer is left in a constant-temperature bath at 40 ° C. in a decap state for 24 hours and then taken out. The head refreshing is performed from the printer driver, and the number of times of the head refreshing required for all the nozzles to discharge is obtained. Maintenance was evaluated based on the criteria. Note that the allowable range is up to Δ.
[Evaluation criteria]
◎: All nozzles discharge when head refreshing is less than 4 times ○: All nozzles discharge when head refreshing is 4 times or more and less than 7 times Δ: All nozzles discharge when head refreshing is 7 times or more and less than 10 times ×: All nozzles eject after 10 or more head refreshing

<Ink storage stability>
40 g of each prepared ink was put in a 50 mL capacity plastic container and stored in a thermostat at 70 ° C. for 14 days, and the change rate of the viscosity after storage with respect to the viscosity before storage was obtained from the following formula and evaluated according to the following criteria. .
The ink viscosity was measured at 25 ° C. using a viscometer (RE80L, manufactured by Toki Sangyo Co., Ltd.). Note that the allowable range is up to Δ.
[Evaluation criteria]
A: Viscosity change rate is less than 5% B: Viscosity change rate is 5% or more and less than 7% Δ: Viscosity change rate is 7% or more and less than 10% X: Viscosity change rate is 10% or more

From the result of Table 8, Examples 1-18 are excellent in abrasion resistance and glossiness compared with Comparative Examples 1-7, while being able to obtain the image of a high image density, and also in blocking property and nozzle maintainability. I found it excellent.

As an aspect of this invention, it is as follows, for example.
<1> An ink containing an organic solvent, polyurethane resin particles, a colorant, and water,
The organic solvent contains a compound having a saturated vapor pressure at 100 ° C. of 65 mmHg or more and 400 mmHg or less,
An ink having a sensor output value of 600 or more at a critical image peeling point by a micro scratch method with respect to a solid image having an adhesion amount of 0.96 mg / cm ² formed on a recording medium. It is.
<2> The arithmetic average roughness Ra of a solid image having an ink adhesion amount of 0.96 mg / cm ² formed on a recording medium is 0.3 μm or more and 0.8 μm or less. Ink.
<3> The ink according to any one of <1> to <2>, wherein the polyurethane resin particles have a glass transition temperature of −30 ° C. or higher and 10 ° C. or lower.
<4> The ink according to any one of <1> to <3>, wherein the polyurethane resin particles have a volume average particle diameter of 8 nm to 19 nm.
<5> From <1> to <1>, wherein a mass ratio (A / B) of content A (mass%) of the polyurethane resin particles and content B (mass%) of the colorant is 1 or more and 5 or less. 4>.
<6> The mass ratio (C / A) between the content A (mass%) of the polyurethane resin particles and the content C (mass%) of a compound having a saturated vapor pressure of 65 mmHg or more and 400 mmHg or less at 100 ° C. The ink according to any one of <1> to <5>, which is 0.85 or more and 3.0 or less.
<7> From the above <1>, the compound having a saturated vapor pressure at 100 ° C. of 65 mmHg or more and 400 mmHg or less is at least one selected from propylene glycol monopropyl ether, propylene glycol monomethyl ether, and 3-methoxybutanol. <6> The ink according to any one of the above.
<8> The ink according to any one of <1> to <7>, wherein the content of the compound having a saturated vapor pressure at 100 ° C. of 65 mmHg to 400 mmHg is 10% by mass to 25% by mass. .
<9> The ink according to any one of <1> to <8>, wherein the sensor output value is 600 or more and 1,000 or less.
<10> The ink according to any one of <1> to <9>, wherein the ink contains an organic solvent having a solubility parameter (SP value) of 11.0 to 14.0.
<11> The ink according to any one of <1> to <10>, wherein the content of the organic solvent is 15% by mass or more and 60% by mass or less.
<12> The ink according to any one of <1> to <11>, wherein the polyurethane resin particles have a weight average molecular weight of 5,000 to 500,000.
<13> The ink according to any one of <1> to <12>, wherein the recording medium is a coated paper for printing.
<14> An ink cartridge comprising the container according to any one of <1> to <13>.
<15> The method includes at least an ink flying step of recording an image on a recording medium by applying a stimulus to the ink according to any one of <1> to <13> and causing the ink to fly. Inkjet recording method.
<16> The inkjet recording method according to <15>, wherein the recording medium is a coated paper for printing.
<17> At least ink flying means for recording an image on a recording medium by applying a stimulus to the ink according to any one of <1> to <13> and causing the ink to fly. Inkjet recording apparatus.
<18> The inkjet recording apparatus according to <17>, wherein the recording medium is a coated paper for printing.
<19> A recorded matter comprising an image formed using the ink according to any one of <1> to <13> on a recording medium.
<20> The recorded matter according to <19>, wherein the recording medium is a coated paper for printing.

  The ink according to any one of <1> to <13>, the ink cartridge according to <14>, the ink jet recording method according to any one of <15> to <16>, and <17> to < 18> and the recorded matter according to any one of <19> to <20> can solve the conventional problems and achieve the object of the present invention. it can.

JP 2014-198824 A JP 2007-76033 A

DESCRIPTION OF SYMBOLS 1 Diamond needle 2 Start point 3 End point 4 Critical image peeling point 5 Scratch direction 6 Solid image 7 Recording medium 10 Ink storage container 11 Ink storage part 20 Ink supply port 134 Recording head 200 Ink storage container

Claims (13)

A set of ink and recording medium containing an organic solvent, polyurethane resin particles, a colorant, and water,
The organic solvent contains a compound having a saturated vapor pressure at 100 ° C. of 65 mmHg or more and 400 mmHg or less,
A sensor output value at a critical image peeling point by the micro scratch method is 600 or more in a solid image in which the ink adhesion amount formed on the recording medium is 0.96 mg / cm ^2. A set of ink and recording media. ^2. The ink and recording according to claim 1, wherein an arithmetic average roughness Ra of a solid image having an ink adhesion amount of 0.96 mg / cm ² formed on the recording medium is 0.3 μm or more and 0.8 μm or less. Media set.   The ink and recording medium set according to claim 1, wherein the polyurethane resin particles have a glass transition temperature of −30 ° C. or higher and 10 ° C. or lower.   4. The ink and recording medium set according to claim 1, wherein the polyurethane resin particles have a volume average particle diameter of 8 nm or more and 19 nm or less.   The mass ratio (A / B) of the content A (mass%) of the polyurethane resin particles and the content B (mass%) of the colorant is 1 or more and 5 or less. A set of ink and recording media as described.   The mass ratio (C / A) between the content A (mass%) of the polyurethane resin particles and the content C (mass%) of the compound having a saturated vapor pressure of 65 mmHg or more and 400 mmHg or less at 100 ° C. is 0.85. The set of ink and recording medium according to any one of claims 1 to 5, wherein the set is 3.0 or less.   7. The compound according to claim 1, wherein the compound having a saturated vapor pressure at 100 ° C. of 65 mmHg to 400 mmHg is at least one selected from propylene glycol monopropyl ether, propylene glycol monomethyl ether, and 3-methoxybutanol. A set of ink and recording media described in 1.   The ink and recording medium set according to any one of claims 1 to 7, wherein the content of the compound having a saturated vapor pressure at 100 ° C of from 65 mmHg to 400 mmHg is from 10% by mass to 25% by mass.   A stimulus is applied to the ink in the set of the ink and the recording medium according to any one of claims 1 to 8, and the ink is caused to fly, so that the ink and the recording medium according to any one of claims 1 to 8 are ejected. An ink jet recording method comprising an ink flying step of recording an image on a recording medium in a set.   A stimulus is applied to the ink in the set of the ink and the recording medium according to any one of claims 1 to 8, and the ink is caused to fly, so that the ink and the recording medium according to any one of claims 1 to 8 are ejected. An ink jet recording apparatus comprising ink flying means for recording an image on a recording medium in a set. A recorded matter having a recording medium and a recording layer,
The recording layer contains an organic solvent, polyurethane resin particles, and a colorant;
The organic solvent contains a compound having a saturated vapor pressure at 100 ° C. of 65 mmHg or more and 400 mmHg or less,
A recording layer having a sensor output value of 600 or more at a critical image peeling point by a micro scratch method in a solid image formed on the recording medium and having an adhesion amount of 0.96 mg / cm ^2. Recorded as An ink used in an ink jet recording method including an ink flying step of applying a stimulus to ink and causing the ink to fly to record an image on a recording medium,
The ink is an ink containing an organic solvent, polyurethane resin particles, a colorant, and water,
The organic solvent contains a compound having a saturated vapor pressure at 100 ° C. of 65 mmHg or more and 400 mmHg or less,
A sensor output value at a critical image peeling point by the micro scratch method is 600 or more in a solid image in which the ink adhesion amount formed on the recording medium is 0.96 mg / cm ^2. ink. The ink and recording medium set according to any one of claims 1 to 8, further comprising an ink storage container configured to store ink in a container.