Ink, ink container, printing device, and printing method

Abstract

To solve the problem that an image formed using ink containing a resin having crystallinity causes deterioration of scratch resistance and water resistance under heavy load while having high blocking resistance.SOLUTION: Provided is Ink contains a polyester urethane resin having crystallinity, where Tm of the polyester urethane resin is 30°C or higher and 100°C or lower, the polyester urethane resin has a structure derived from crystalline polyester polyol, a structure derived from non-ionic short-chain polyol having 2 to 10 carbon atoms, and a structure derived from ionic short-chain polyol having 2 to 6 carbon atoms, and in the polyester urethane resin, a mol number A of an urethane group derived from the hydroxyl group of the crystalline polyester polyol, a mol number B of the urethane group derived from the hydroxyl group of the non-ionic short-chain polyol having 2 to 10 carbon atoms, and a mol number C of the urethane group derived from the hydroxyl group of the ionic short-chain polyol having 2 to 6 carbon atoms satisfy a predetermined relation.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an ink, an ink container, a printing device, and a printing method. [Background technology]

[0002] When ink used in inkjet printing is printed on a low-permeability substrate, the ink has low permeability to the low-permeability substrate, and when multiple substrates are superimposed after printing, a blocking phenomenon may occur, in which the image on one substrate sticks to the other substrate. A common method for solving this problem is to include a resin in the ink to enhance the film-forming properties of the ink and suppress the blocking phenomenon. Using a crystalline resin as the resin can enhance film-forming properties when heated at a temperature above its melting point.

[0003] Patent Document 1 discloses an ink containing a crystalline polyester resin.

[0004] Furthermore, Patent Documents 2 and 3 disclose inks containing crystalline urethane resins. Summary of the Invention [Problem to be solved by the invention]

[0005] However, while images formed using inks containing crystalline resins have high blocking resistance, they also have the problems of reduced abrasion resistance under high loads and reduced water resistance. [Means for solving the problem]

[0006] The present invention relates to an ink containing a crystalline polyester urethane resin, wherein the polyester urethane resin has a melting peak temperature (Tm) of 30°C or higher and 100°C or lower, the polyester urethane resin has a structure derived from a crystalline polyester polyol, a structure derived from a nonionic short-chain polyol having from 2 to 10 carbon atoms, and a structure derived from an ionic short-chain polyol having from 2 to 6 carbon atoms, and the polyester urethane resin has a structure derived from a crystalline polyester polyol, a structure derived from a nonionic short-chain polyol having from 2 to 10 carbon atoms, and a structure derived from an ionic short-chain polyol having from 2 to 6 carbon atoms. The following formula, "B / (A+B+C)", which represents the relationship between the number of moles of urethane groups A derived from hydroxyl groups of the crystalline polyester polyol, the number of moles of urethane groups B derived from hydroxyl groups of the nonionic short-chain polyol having from 2 to 10 carbon atoms, and the number of moles of urethane groups C derived from hydroxyl groups of the ionic short-chain polyol having from 2 to 6 carbon atoms, is 0.15 or higher and 0.50 or lower. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide an ink that improves the blocking resistance, abrasion resistance under high load, and water resistance of an image formed using an ink containing a crystalline resin. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view illustrating an example of a printing device. [Figure 2] FIG. 2 is a perspective explanatory view showing an example of a main tank. DETAILED DESCRIPTION OF THE INVENTION

[0009] An example of an embodiment of the present invention will be described below.

[0010] <<Ink>> The ink of this embodiment contains a resin, and may contain other components such as a coloring material, water, an organic solvent, and a surfactant, as needed.

[0011] <Resin> The ink of this embodiment contains a crystalline polyester urethane resin as a resin, and may further contain other types of resins as necessary. The other types of resins are not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include urethane resins other than crystalline polyester urethane resins, polyester resins, acrylic resins, vinyl acetate resins, styrene resins, butadiene resins, styrene-butadiene resins, vinyl chloride resins, acrylic styrene resins, acrylic silicone resins, etc. These may be used alone or in combination of two or more. Hereinafter, the crystalline polyester urethane resin will be described in detail.

[0012] -Crystalline polyester urethane resin- A "crystalline polyester urethane resin (hereinafter simply referred to as a "polyester urethane resin")" is a resin having structural units containing a crystalline polyester structure, and may contain other structural units as necessary. The "structural unit" refers to a partial structure in the polymer derived from the materials used in polymerizing the resin. Furthermore, a "crystalline" polyester urethane resin refers to a polyester urethane resin that has an endothermic peak when measured using a differential scanning calorimeter (DSC) under the measurement conditions described below, and preferably refers to a polyester urethane resin whose heat of fusion at the endothermic peak is 5 J / g or more. The polyester urethane resin melts or dissolves the ink after application to a substrate and then heat-dries it to reduce its viscosity. It then recrystallizes, improving the ink's film-forming properties and allowing the creation of images with excellent blocking resistance. This improves the blocking resistance of images, even when the ink is applied to a substrate with low permeability, which generally tends to reduce blocking resistance. Furthermore, because the polyester urethane resin has a structure in which crystalline polyester moieties are linked by urethane bonds, it has improved resistance to organic solvents contained in the ink, improving stability when the resin is contained in the ink in the form of resin particles. This allows the creation of inks with excellent storage stability, even at high temperatures.

[0013] The polyester urethane resin exhibits an endothermic peak when measured using a differential scanning calorimeter (DSC) under the following measurement conditions. Specifically, during the second heating process, the resin preferably exhibits a melting peak temperature (Tm) (hereinafter referred to simply as "melting point") in the range of 30°C to 100°C, more preferably in the range of 30°C to 85°C, and even more preferably in the range of 36°C to 76°C. A melting point of 30°C or higher strengthens the ink film on the printed substrate after drying, resulting in high abrasion resistance. Furthermore, a melting point of 100°C or lower strengthens the adhesion between resins and between the resin and the printed substrate, which is caused by heat drying, thereby improving blocking resistance. (Measurement conditions) 4 g of "aqueous dispersion of polyester urethane resin" or "aqueous dispersion of polyester urethane resin isolated from ink containing polyester urethane resin" is placed in a container so that it is evenly distributed. It is then dried at 70°C for 1 hour, then at 130°C for 1 hour, and then further dried under reduced pressure at 130°C to obtain a solid sample for measurement. The thermal properties of the sample are then measured using a differential scanning calorimeter (DSC) (TA Instruments Q2000) under the following conditions. A graph of endothermic heat generation vs. temperature is created from the measurement results, and the temperature at the apex of the melting (endothermic) peak obtained during the second heating process is taken as the melting point. Sample container: Aluminum sample pan (with lid) Sample size: 5mg Reference aluminum crucible (empty container) Atmosphere: Nitrogen (flow rate 50 mL / min) ·Starting temperature: -80℃ Heating rate: 10℃ / min ·End temperature: 130℃ ·Holding time: 1min ·Cooling rate: 10℃ / min ·End temperature: -80℃ ·Holding time: 5min Heating rate: 10℃ / min ·End temperature: 130℃

[0014] The heat of fusion at the endothermic peak of the polyester urethane resin is preferably 5 J / g or more and 100 J / g or less, more preferably 10 J / g or more and 80 J / g or less, and even more preferably 20 J / g or more and 50 J / g or less. When the heat of fusion is 5 J / g or more, the crystallinity of the crystalline portion increases, so that the viscosity is sufficiently reduced during the heat drying process, and the deterioration of blocking resistance in the image is suppressed. Furthermore, when it is 100 J / g or less, the resin can be prevented from becoming excessively hard and brittle, and the abrasion resistance is improved.

[0015] As described later in the method for producing a polyester urethane resin, the polyester urethane resin has a structure derived from a crystalline polyester polyol, a structure derived from a nonionic short-chain polyol having 2 to 10 carbon atoms, and a structure derived from an ionic short-chain polyol having 2 to 6 carbon atoms. Furthermore, in the polyester urethane resin, the following formula "B / (A+B+C)" which represents the relationship between the number of moles A of urethane groups derived from hydroxyl groups of the crystalline polyester polyol, the number of moles B of urethane groups derived from hydroxyl groups of the nonionic short-chain polyol having 2 to 10 carbon atoms, and the number of moles C of urethane groups derived from hydroxyl groups of the ionic short-chain polyol having 2 to 6 carbon atoms is 0.15 or more and 0.50 or less, and preferably 0.25 or more and 0.40 or less. The reason why the above formula is preferably 0.15 or more and 0.50 or less will be explained below. When the proportion of structures derived from crystalline polyester polyols in a polyester urethane resin is large (when the proportion of A is large), the proportion of crystalline structural portions in the polyester urethane resin increases, resulting in hard and brittle properties and reduced scratch resistance in the image. In contrast, by increasing the proportion of structures derived from short-chain polyols in the polyester urethane resin (by increasing the proportions of B and C), the concentration of urethane groups in the polyester urethane resin increases, and the attractive force resulting from hydrogen bonding between urethane groups within and between polyester urethane resins increases, improving strength. This allows the scratch resistance of the image to be improved even if the polyester urethane resin molecule contains a structure derived from a crystalline polyester polyol. On the other hand, when the proportion of structures derived from ionic short-chain polyols is increased as a structure derived from a short-chain polyol (when the proportion of C is increased), the hydrophilicity of the polyester urethane resin is excessively improved, resulting in reduced water resistance in the image. As described above, by adjusting the above formula to 0.15 or more and 0.50 or less, it is possible to provide an ink that can improve the blocking resistance of an image while also improving the abrasion resistance and water resistance. Furthermore, this makes it possible to improve the abrasion resistance of an image, for example, even when an image is formed by applying the ink to a printing substrate with low permeability, which generally tends to have reduced abrasion resistance.

[0016] As described above, the polyester urethane resin has a structure derived from a crystalline polyester polyol, a structure derived from a nonionic short-chain polyol having from 2 to 10 carbon atoms, and a structure derived from an ionic short-chain polyol having from 2 to 6 carbon atoms, but may also have a structure derived from other alcohol components, if necessary. However, from the viewpoint of blocking resistance and abrasion resistance, the total number of moles A of urethane groups derived from hydroxyl groups of the crystalline polyester polyol, the number of moles B of urethane groups derived from hydroxyl groups of the nonionic short-chain polyol having from 2 to 10 carbon atoms, and the number of moles C of urethane groups derived from hydroxyl groups of the ionic short-chain polyol having from 2 to 6 carbon atoms is preferably 0.70 to 1.00 relative to the number of moles of all urethane groups in the polyester urethane resin.

[0017] Furthermore, the structure derived from the nonionic short-chain polyol having from 2 to 10 carbon atoms preferably has a structure derived from a nonionic short-chain polyol having from 4 to 6 carbon atoms. By having a structure derived from a nonionic short-chain polyol having from 4 to 6 carbon atoms, the urethane group concentration in the polyester urethane resin falls within a more appropriate range, and the scratch resistance of the image is further improved.

[0018] Furthermore, the structure derived from the nonionic short-chain polyol having 2 to 10 carbon atoms preferably includes a structure derived from a bifunctional nonionic short-chain polyol having 2 to 10 carbon atoms and a structure derived from a trifunctional nonionic short-chain polyol having 3 to 6 carbon atoms. When a structure derived from a trifunctional nonionic short-chain polyol having 3 to 6 carbon atoms is included, a chemical crosslinked structure can be introduced into the polyester urethane resin, thereby increasing the toughness of the polyester urethane resin and improving the abrasion resistance of the image. However, if all of the structures derived from nonionic short-chain polyols having 2 to 10 carbon atoms are replaced with structures derived from trifunctional nonionic short-chain polyols having 3 to 6 carbon atoms, the excessive chemical crosslinked structure will result in the polyester urethane resin being hard and brittle, resulting in insufficient improvement in the abrasion resistance of the image. Therefore, it is preferable to further improve the abrasion resistance of the image by including both a structure derived from a bifunctional nonionic short-chain polyol having 2 to 10 carbon atoms and a structure derived from a trifunctional nonionic short-chain polyol having 3 to 6 carbon atoms. Furthermore, in polyester urethane resins, the following formula "E / (D+E)" representing the relationship between the number of moles D of urethane groups derived from hydroxyl groups of bifunctional nonionic short-chain polyols having 2 to 10 carbon atoms and the number of moles E of urethane groups derived from hydroxyl groups of trifunctional nonionic short-chain polyols having 3 to 6 carbon atoms is preferably 0.10 to 0.40, more preferably 0.15 to 0.30. As described above, the scratch resistance of images can be further improved by appropriately controlling the ratio of the structure derived from bifunctional nonionic short-chain polyols having 2 to 10 carbon atoms and the structure derived from trifunctional nonionic short-chain polyols having 3 to 6 carbon atoms. Note that D and E are elements included in the above B, and therefore when dealing with B, D and E are included in the calculation of B.

[0019] The structure derived from a trifunctional nonionic short-chain polyol having 3 to 6 carbon atoms preferably has a structure derived from a trifunctional nonionic short-chain polyol having 6 carbon atoms. Having a structure derived from a trifunctional nonionic short-chain polyol having 6 carbon atoms makes the distance between crosslinking points appropriate, leading to high abrasion resistance. Furthermore, the structure derived from a trifunctional nonionic short-chain polyol having 6 carbon atoms preferably has a structure derived from trimethylolpropane. Since trimethylolpropane has three hydroxyl groups equidistantly spaced from the center of the molecule, when the polyester urethane resin has a structure derived from trimethylolpropane, crosslinking structures can be uniformly introduced into the polyester urethane resin molecules, thereby increasing the toughness of the polyester urethane resin and improving abrasion resistance.

[0020] The quality and quantity of the resin can be confirmed, for example, by the procedure described in detail in the following Reference 1. Specifically, the quality and quantity can be confirmed by analysis based on the measurement method shown below. [Reference 1] "Test methods and evaluation results for dynamic properties of plastic materials (22); Takeo Yasuda, Plastics: Magazine of the Japan Plastics Industry Federation / Edited by the "Plastics" Editorial Committee"

[0021] (Infrared Spectroscopy (IR)) Qualitative analysis of resins can be performed by measuring the absorption wavelengths of various functional groups in the resin and comparing them with the IR spectra of known resins. Also, by comparing the absorbance of the functional groups in the resin, the relative amounts of several types of monomers and resins can be compared.

[0022] (Pyrolysis Gas Chromatography (PyGC)) The pyrolysis products can be separated by gas chromatography and subjected to compositional and structural analysis. Furthermore, more accurate analysis can be performed by directly connecting a mass spectrometer to the PyGC and identifying the pyrolysis products generated by pyrolysis.

[0023] (Nuclear magnetic resonance (NMR)) By comparing the spectra with those of known resins, resins can be identified and confirmed. In the case of unknown resins, the molecular structure can be estimated. Furthermore, quantitative analysis of the composition ratio and blend ratio of copolymers and blends of multiple polymers can be performed.

[0024] Before analyzing the resin by the above-mentioned measurement method, it is also effective to perform pretreatment such as precipitating the colorant components in the ink by centrifugation and recovering the supernatant containing the resin, or extracting the resin using an appropriate organic solvent, as a means for improving analytical accuracy.

[0025] The acid value of the polyester urethane resin is preferably 10 mgKOH / g or more and 40 mgKOH / g or less. By setting it within this range, images formed using the ink have excellent mechanical strength, and images with excellent fixability and blocking resistance can be formed. Furthermore, when the acid value is 10 mgKOH / g or more, the dispersion stability of the resin is improved, resulting in the formation of a uniform coating, and images with excellent mechanical strength can be formed. Furthermore, when the acid value is 40 mgKOH / g or less, not only can a coating with excellent mechanical strength be formed, but the hydrophilicity of the resin is appropriate, resulting in improved water resistance and improved water resistance of printed materials. The acid value of the polyester urethane resin can be measured, for example, by placing the polyester urethane resin in a tetrahydrofuran (THF) solution and titrating it with a 0.1 M solution of potassium hydroxide in methanol. The acid value of the polyester urethane resin may be calculated from the carboxyl group concentration in the resin constituent materials when the resin is produced, or it may be measured by placing the polyester urethane resin in a tetrahydrofuran (THF) solution and titrating it with a 0.1 M potassium hydroxide methanol solution. In addition, when the carboxyl groups in the polyester urethane resin are neutralized, the carboxyl content can also be measured by, for example, adding an excess of aqueous hydrochloric acid to make an acidic solution, extracting the resin with chloroform, and then heating or drying under reduced pressure to obtain a resin, dissolving the resulting resin in THF, and titrating it with a 0.1 M solution of potassium hydroxide in methanol.

[0026] The polyester urethane resin is preferably in the form of a resin emulsion, which refers to a state in which resin particles are dispersed in water or ink, regardless of whether the resin particles are solid or liquid. Methods for dispersing resin particles containing polyester urethane resin in water or ink include forced emulsification using a dispersant, self-emulsification using a resin having an anionic group, etc. In the case of forced emulsification, the dispersant may remain in the image formed with the ink, which may reduce the strength of the image, so it is preferable to use the self-emulsification method. Examples of the anionic group include a carboxyl group, a carboxylate group, a sulfonic acid group, a sulfonate group, etc. Among these, it is preferable to use a carboxylate group or a sulfonate group that is partially or completely, particularly preferably completely, neutralized with a basic compound or the like. Examples of neutralizing agents that can be used to neutralize the anionic groups include basic compounds such as organic amines such as ammonia, triethylamine, pyridine, and morpholine, and alkanolamines such as monoethanolamine, and metal base compounds including Na, K, Li, and Ca.

[0027] When polyester urethane resin is used as the resin particles, the volume average particle size of the resin particles is preferably 30 nm to 120 nm, more preferably 50 nm to 100 nm. By increasing the volume average particle size of the resin particles to 30 nm or more, penetration of the resin particles into the printed substrate can be suppressed, increasing the proportion of resin particles contained in the ink film on the printed substrate and leading to improved abrasion resistance. Furthermore, by increasing the volume average particle size of the resin particles to 120 nm or less, the film-forming properties of the resin particles are improved, resulting in a tougher ink film and improved abrasion resistance. The volume average particle size of the resin particles can be controlled by the amount of anionic groups in the resin and the amount of neutralizer used for the anionic groups during emulsification. The volume average particle size can be measured, for example, using a particle size analyzer (Nanotrac Wave-UT151, manufactured by Microtrac Bell Co., Ltd.).

[0028] The content of the polyester urethane resin is not particularly limited and can be selected appropriately depending on the purpose, but from the viewpoint of abrasion resistance, it is preferably from 1% by mass to 30% by mass, and more preferably from 5% by mass to 20% by mass, of the total amount of ink.

[0029] -Method for producing crystalline polyester urethane resin- An example of a method for producing a polyester urethane resin is as follows. First, in the absence of a solvent or in the presence of an organic solvent, a crystalline polyester polyol, a nonionic short-chain polyol having from 2 to 10 carbon atoms, an ionic short-chain polyol having from 2 to 6 carbon atoms, and a polyisocyanate are reacted to produce an isocyanate-terminated urethane prepolymer. During this reaction, polyether polyol, polycarbonate polyol, amorphous polyester polyol, and the like can also be mixed in as needed. Next, the anionic groups in the isocyanate-terminated urethane prepolymer are neutralized with a neutralizing agent as needed, followed by adding water to disperse the prepolymer, and finally, as needed, removing the organic solvent from the system to obtain a polyesterurethane resin. Furthermore, before removing the organic solvent, if needed, a divalent or higher polyamine (hereinafter also referred to as a "polyamine") can be added to extend or crosslink the polyesterurethane resin through the urea bond formed between the terminal isocyanate group and the polyamine.

[0030] Examples of organic solvents that can be used during the reaction 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, amides such as dimethylformamide, N-methylpyrrolidone and 1-ethyl-2-pyrrolidone, etc. These may be used alone or in combination of two or more.

[0031] --Crystalline polyester polyol-- The crystalline polyester polyol preferably has a hydroxyl value (OHV) of 20 mgKOH / g or more and 200 mgKOH / g or less, more preferably 50 mgKOH / g or more and 150 mgKOH / g or less, and even more preferably 70 mgKOH / g or more and 120 mgKOH / g or less. When the hydroxyl value is within the above range, the dispersion stability of the resin becomes good, and by exhibiting appropriate crystallinity, it is possible to obtain a polyester urethane resin that is capable of forming images with excellent blocking resistance.

[0032] The type of crystalline polyester polyol is not particularly limited and can be appropriately selected depending on the purpose, but aliphatic polyester polyols are preferred because they have high crystallinity.

[0033] The molecular weight of the crystalline polyester polyol is not particularly limited and can be appropriately selected depending on the purpose, but the weight average molecular weight (Mw) measured by GPC is preferably 2,000 to 20,000, more preferably 3,000 to 15,000, still more preferably 3,000 to 10,000, and particularly preferably 3,000 to 5,000. When the weight average molecular weight is within the above range, the dispersion stability of the resin is good, and by exhibiting appropriate crystallinity, a crystalline polyester urethane resin emulsion capable of forming images with excellent fixability can be obtained. The number average molecular weight (Mn) of the crystalline polyester polyol is preferably from 1,000 to 4,000, and more preferably from 2,000 to 3,000.

[0034] The melting point (Tm) of the crystalline polyester polyol is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 50°C or higher and 100°C or lower. The melting point can be measured from the endothermic peak value on a DSC chart in differential scanning calorimetry (DSC) measurement. The crystallinity, molecular structure, etc. of the crystalline polyester can be confirmed by NMR measurement, differential scanning calorimetry (DSC) measurement, X-ray diffraction measurement, GC / MS measurement, LC / MS measurement, infrared absorption (IR) spectroscopy measurement, etc.

[0035] Next, an example of a method for producing a crystalline polyester polyol will be described. The crystalline polyester polyol is preferably produced, for example, by polycondensation of a polyhydric alcohol and a polycarboxylic acid in the absence of a solvent or in the presence of an organic solvent. That is, the crystalline portion of the polyester urethane resin is derived from the polyhydric alcohol and the polycarboxylic acid used in the production of the crystalline polyester polyol.

[0036] ---Polyhydric alcohols--- The polyhydric alcohol is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include diols and trihydric or higher alcohols. As the diol, for example, an aliphatic diol is preferable, and a saturated aliphatic diol is more preferable. Examples of saturated aliphatic diols include linear saturated aliphatic diols and branched saturated aliphatic diols. Among these, linear saturated aliphatic diols are preferred, and linear saturated aliphatic diols having 2 to 12 carbon atoms are more preferred. When the saturated aliphatic diol is linear, the crystallinity of the crystalline polyester is not reduced, and the melting point is less likely to decrease. When the saturated aliphatic diol has 12 or less carbon atoms, the material is easily available, so it is more preferred that the carbon number is 12 or less. Examples of saturated aliphatic diols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, 1,14-eicosanedecanediol, etc. These may be used alone or in combination of two or more. Examples of trihydric or higher alcohols include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, etc. These may be used alone or in combination of two or more.

[0037] ---Polycarboxylic acids--- The polycarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples include dicarboxylic acids and tricarboxylic or higher carboxylic acids, but aliphatic dicarboxylic acids are preferred. Examples of dicarboxylic acids include saturated aliphatic dicarboxylic acids such as oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, and 1,18-octadecanedicarboxylic acid; aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, malonic acid, and mesaconic acid, as well as anhydrides thereof and lower (C1 to C3) alkyl esters thereof. These may be used alone or in combination of two or more. Examples of trivalent or higher carboxylic acids include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, anhydrides thereof, and lower (C1 to C3) alkyl esters thereof. These may be used alone or in combination of two or more. The polycarboxylic acid may include saturated aliphatic dicarboxylic acids, aromatic dicarboxylic acids, dicarboxylic acids having a sulfonic acid group, dicarboxylic acids having a double bond, and the like. The polycarboxylic acid may include saturated aliphatic dicarboxylic acids, aromatic dicarboxylic acids, dicarboxylic acids having a sulfonic acid group, dicarboxylic acids having a double bond, and the like.

[0038] --Nonionic short-chain polyol having 2 to 10 carbon atoms-- As the nonionic short-chain polyol having 2 or more and 10 or less carbon atoms, a bifunctional nonionic short-chain polyol, a trifunctional nonionic short-chain polyol, or the like can be used.

[0039] The difunctional nonionic short-chain polyol is preferably a difunctional nonionic short-chain polyol having from 2 to 10 carbon atoms, and examples thereof include polyhydric alcohols having from 2 to 10 carbon atoms, such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,8-octanediol, 1,4-cyclohexanedimethanol, and diethylene glycol.

[0040] The trifunctional nonionic short-chain polyol is preferably a trifunctional nonionic short-chain polyol having 3 or more and 6 or less carbon atoms, and examples thereof include polyhydric alcohols having 3 or more and 6 or less carbon atoms, such as glycerin, trimethylolpropane, 1,2,4-butanetriol, 1,2,5-pentanetriol, 1,2,6-hexanetriol, 1,2,4-benzenetriol, 1,3,5-benzenetriol, and 1,2,3-benzenetriol.

[0041] --Ionic short-chain polyol having 2 to 6 carbon atoms-- The ionic short-chain polyol having 2 to 6 carbon atoms is not particularly limited, but may be a material having two or more hydroxyl groups and a functional group such as a carboxylic acid or sulfonic acid as an anionic group. Examples include carboxylic acid groups such as dimethylolpropionic acid, dimethylolbutanoic acid, dimethylolbutyric acid, dimethylolvaleric acid, trimethylolpropanoic acid, and trimethylolbutanoic acid, and sulfonic acid groups such as 1,4-butanediol-2-sulfonic acid.

[0042] --Polyisocyanate-- Examples of polyisocyanates include 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate (TDI), 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), 2,4-diphenylmethane diisocyanate, 4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatobiphenyl, 3,3'-diisocyanatobiphenyl, Aromatic polyisocyanate compounds such as methyl-4,4'-diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate, 4,4',4''-triphenylmethane triisocyanate, m-isocyanatophenylsulfonyl isocyanate, p-isocyanatophenylsulfonyl isocyanate; ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene Aliphatic polyisocyanate compounds such as diisocyanates, 1,6,11-undecane triisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethyl caproate, bis(2-isocyanatoethyl) fumarate, bis(2-isocyanatoethyl) carbonate, and 2-isocyanatoethyl-2,6-diisocyanatohexanoate; isophorone diisocyanate and alicyclic polyisocyanate compounds such as bis(2-isocyanatoethyl)-4-dicyclohexene-1,2-dicarboxylate, 2,5-norbornane diisocyanate, and 2,6-norbornane diisocyanate. These may be used alone or in combination of two or more. Among these, aliphatic polyisocyanate compounds and alicyclic polyisocyanate compounds are preferred, alicyclic polyisocyanate compounds are more preferred, and isophorone diisocyanate and 4,4'-dicyclohexylmethane diisocyanate are particularly preferred.

[0043] --Polyether polyol-- As the polyether polyol, for example, a product obtained by addition polymerization of alkylene oxide with one or more compounds having two or more active hydrogen atoms as a starting material can be used. Examples of starting materials include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, glycerin, trimethylolethane, and trimethylolpropane. Examples of alkylene oxides include ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, and tetrahydrofuran. As the polyether polyol, polyoxytetramethylene glycol and polyoxypropylene glycol are preferred in terms of obtaining a binder for ink-jet printing ink that can impart very good abrasion resistance.

[0044] --Polycarbonate polyol-- As the polycarbonate polyol, for example, those obtained by reacting a carbonate ester with a polyol, or those obtained by reacting phosgene with bisphenol A or the like can be used. Examples of carbonate esters include methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, and diphenyl carbonate. Examples of polyols that can react with carbonate esters 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, and 1,10-decanediol. Examples of the polyol include relatively low molecular weight dihydroxy compounds such as bisphenol A, bisphenol F, 1,11-undecanediol, 1,12-dodecanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, hydroquinone, resorcinol, bisphenol A, bisphenol F, and 4,4'-biphenol; polyether polyols such as polyethylene glycol, polypropylene glycol, and polyoxytetramethylene glycol; and polyester polyols such as polyhexamethylene adipate, polyhexamethylene succinate, and polycaprolactone.

[0045] --Amorphous polyester polyol-- Examples of amorphous polyester polyols include those obtained by an esterification reaction between a low-molecular-weight polyol and a polycarboxylic acid, polyesters obtained by a ring-opening polymerization reaction of a cyclic ester compound such as ε-caprolactone, and copolymer polyesters thereof. Examples of low molecular weight polyols include ethylene glycol and propylene glycol. Examples of polycarboxylic acids include succinic acid, adipic acid, sebacic acid, dodecanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, and anhydrides or ester-forming derivatives thereof.

[0046] --Divalent or higher polyamines-- Examples of divalent or higher polyamines include diamines such as ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4'-dicyclohexylmethanediamine, and 1,4-cyclohexanediamine; polyamines such as diethylenetriamine, dipropylenetriamine, and triethylenetetramine; hydrazines such as hydrazine, N,N'-dimethylhydrazine, and 1,6-hexamethylenebishydrazine; and dihydrazides such as succinic acid dihydrazide, adipic acid dihydrazide, glutaric acid dihydrazide, sebacic acid dihydrazide, and isophthalic acid dihydrazide.

[0047] -Crosslinking in crystalline polyester urethane resin- The polyester urethane resin preferably has, in addition to hydrogen bonds, which are one of its original characteristics, chemical crosslinks derived from covalent bonds in its molecular structure. The presence of chemical crosslinks derived from covalent bonds gives the polyester urethane resin excellent mechanical strength, and allows the final image to have excellent abrasion resistance and blocking resistance. Examples of methods for introducing chemical crosslinks include increasing the number of functional groups of the crystalline polyester polyol to more than 2, using a tri- or higher functional short-chain polyhydric alcohol, using a tri- or higher functional polyisocyanate, or using a tri- or higher functional polyamine. Any of the methods for introducing chemical crosslinks may be used alone, or a combination of two or more methods may be used. While any of the methods for introducing chemical crosslinks can be suitably used, a method using a tri- or higher functional short-chain polyol is particularly preferred from the viewpoint of crosslink density.

[0048] <Colorant> The coloring material is not particularly limited, and pigments and dyes can be used. As the pigment, inorganic pigments or organic pigments can be used. These can be used alone or in combination of two or more. Mixed crystals can also be used as pigments. Examples of pigments that can be used include black pigments, yellow pigments, magenta pigments, cyan pigments, white pigments, green pigments, orange pigments, glossy pigments such as gold and silver pigments, and metallic pigments. As inorganic pigments, titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, chrome yellow, as well as carbon black produced by known methods such as the contact method, furnace method, and thermal method can be used. In addition, examples of organic pigments that can be used include azo pigments, polycyclic pigments (e.g., phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, and quinophthalone pigments), dye chelates (e.g., basic dye chelates and acid dye chelates), nitro pigments, nitroso pigments, and aniline black. Of these pigments, those with good affinity for the solvent are preferably used. In addition, resin hollow particles and inorganic hollow particles can also be used. Specific examples of pigments for black include carbon blacks (CI Pigment Black 7) such as furnace black, lamp black, acetylene black, and channel black, metals such as copper, iron (CI Pigment Black 11), and titanium oxide, and organic pigments such as aniline black (CI Pigment Black 1). In addition, for color, CI Pigment Yellow 1, 3, 12, 13, 14, 17, 24, 34, 35, 37, 42 (yellow iron oxide), 53, 55, 74, 81, 83, 95, 97, 98, 100, 101, 104, 108, 109, 110, 117, 120, 138, 150, 153, 155, 180, 185, 213, CI Pigment Yellow Ranges 5, 13, 16, 17, 36, 43, 51, CI 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 (Red Iron), 104, 105, 106, 108 (Cadmium Red), 112, 114, 122 (Quinacridone Magenta), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 184, 185, 190, 193, 202, 207, 208, 209, 213, 219, 224, 254, 264, CI Pigment Violet 1 (Rhodamine Lake), 3, 5:1, 16, 19, 23, 38; CI Pigment Blue 1, 2, 15 (Phthalocyanine Blue), 15:1, 15:2, 15:3, 15:4 (Phthalocyanine Blue), 16, 17:1, 56, 60, 63; CI Pigment Green 1, 4, 7, 8, 10, 17, 18, 36, etc. The dye is not particularly limited, and acid dyes, direct dyes, reactive dyes, and basic dyes can be used, and one type may be used alone, or two or more types may be used in combination. Dyes include, for example, CI Acid Yellow 17, 23, 42, 44, 79, 142, CI Acid Red 52, 80, 82, 249, 254, 289, CI Acid Blue 9, 45, 249, CI Acid Black 1, 2, 24, 94, CI Food Black 1, 2, CI Direct Yellow 1, 12, 24, 33, 50, 55, 58, 86, 132, 142, 144, 173, CI Direct Red 1, 4, 9, 80, 81, 225, 227, CI Direct Blue 1, 2, 15, 71, 86, 87, 98, 165, 199, 202, CI Directed Black 19, 38, 51, 71, 154, 168, 171, 195, and CI Reactive Red. 14, 32, 55, 79, 249, and CI Reactive Black 3, 4, and 35.

[0049] The content of the colorant in the ink is preferably from 0.1% to 15% by mass, and more preferably from 1% to 10% by mass, relative to the total amount of ink, from the viewpoints of improving image density, good fixability, and ejection stability.

[0050] Methods for dispersing a pigment to obtain an ink include a method of introducing a hydrophilic functional group into a pigment to make it a self-dispersing pigment, a method of dispersing the pigment by coating the surface of the pigment with a resin, and a method of dispersing the pigment using a dispersant. As a method for introducing a hydrophilic functional group into a pigment to make it a self-dispersible pigment, for example, a method of adding a functional group such as a sulfone group or a carboxyl group to a pigment (e.g., carbon) to make it dispersible in water can be mentioned. One method for dispersing a pigment by coating its surface with a resin is to encapsulate the pigment in microcapsules to make it dispersible in water. This can also be called a resin-coated pigment. In this case, it is not necessary for all of the pigments blended into the ink to be coated with resin; uncoated or partially coated pigments may be dispersed in the ink. Examples of the method for dispersing using a dispersant include a method for dispersing using a known low molecular weight dispersant or a high molecular weight dispersant, such as a surfactant. As the dispersant, for example, anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, etc. can be used depending on the pigment. As the dispersant, RT-100 (nonionic surfactant) manufactured by Takemoto Yushi Co., Ltd. and sodium naphthalenesulfonate formalin condensate can also be suitably used. The dispersants may be used alone or in combination of two or more.

[0051] <Organic solvents> The organic solvent is not particularly limited, and any water-soluble organic solvent can be used, including, for example, polyhydric alcohols, ethers such as polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, and sulfur-containing compounds. Specific examples of polyhydric alcohols include ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,2-pentanediol, 1,3-pentanediol, and 1,4-pentanediol. Examples of suitable glycerol include 2,4-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, 1,5-hexanediol, glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-hexanediol, ethyl-1,2,4-butanetriol, 1,2,3-butanetriol, 2,2,4-trimethyl-1,3-pentanediol, and petriol. Examples of polyhydric alcohol alkyl ethers include ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether. Examples of polyhydric alcohol aryl ethers include ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether. Examples of the nitrogen-containing heterocyclic compound include 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, and γ-butyrolactone. Examples of amides include formamide, N-methylformamide, N,N-dimethylformamide, 3-methoxy-N,N-dimethylpropionamide, and 3-butoxy-N,N-dimethylpropionamide. Examples of the amines include monoethanolamine, diethanolamine, and triethylamine. Examples of sulfur-containing compounds include dimethyl sulfoxide, sulfolane, and thiodiethanol. Other organic solvents include propylene carbonate and ethylene carbonate. It is preferable to use an organic solvent having a boiling point of 250° C. or less, since it not only functions as a wetting agent but also provides good drying properties.

[0052] As the organic solvent, polyol compounds having 8 or more carbon atoms and glycol ether compounds are also suitably used. Specific examples of polyol compounds having 8 or more carbon atoms include 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol. Specific examples of glycol ether compounds include polyhydric alcohol alkyl ethers such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether; and polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.

[0053] Polyol compounds having 8 or more carbon atoms and glycol ether compounds can improve the permeability of ink when paper is used as the printing substrate.

[0054] The content of the organic solvent in the ink is not particularly limited and can be selected appropriately depending on the purpose. From the viewpoint of the drying property and ejection reliability of the ink, however, the content is preferably from 10% by mass to 60% by mass, and more preferably from 20% by mass to 60% by mass, of the total amount of the ink.

[0055] <Water> The water content in the ink is not particularly limited and can be selected appropriately depending on the purpose. From the viewpoint of the drying property and ejection reliability of the ink, however, the water content is preferably 10% by mass or more and 90% by mass or less, and more preferably 20% by mass or more and 60% by mass or less, of the total amount of ink.

[0056] <Surfactant> As the surfactant, any of silicone surfactants, fluorine surfactants, amphoteric surfactants, nonionic surfactants and anionic surfactants can be used. The silicone surfactant is not particularly limited and can be appropriately selected depending on the purpose. Among them, those that do not decompose even at high pH are preferred. Examples of silicone surfactants include side-chain modified polydimethylsiloxane, both-end modified polydimethylsiloxane, one-end modified polydimethylsiloxane, and both-end modified polydimethylsiloxane of the side chain. Those having a polyoxyethylene group or a polyoxyethylene polyoxypropylene group as the modifying group are particularly preferred because they exhibit good properties as aqueous surfactants. Furthermore, polyether-modified silicone surfactants can also be used as silicone surfactants, and examples thereof include compounds in which a polyalkylene oxide structure is introduced into the Si part side chain of dimethylsiloxane. As fluorosurfactants, for example, perfluoroalkyl sulfonic acid compounds, perfluoroalkyl carboxylic acid compounds, perfluoroalkyl phosphate ester compounds, perfluoroalkyl ethylene oxide adducts, and polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups in the side chain are particularly preferred due to their low foaming properties. Examples of perfluoroalkyl sulfonic acid compounds include perfluoroalkyl sulfonic acid and perfluoroalkyl sulfonate salts. Examples of perfluoroalkyl carboxylic acid compounds include perfluoroalkyl carboxylic acids and perfluoroalkyl carboxylate salts. Examples of polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups in the side chain include sulfate ester salts of polyoxyalkylene ether polymers having perfluoroalkyl ether groups in the side chain, and salts of polyoxyalkylene ether polymers having perfluoroalkyl ether groups in the side chain. Examples of counter ions of the salts in these fluorosurfactants include Li, Na, K, NH, NHCHCHOH, NH(CHCHOH), NH(CHCHOH), and the like. Examples of amphoteric surfactants include lauryl aminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, and lauryl dihydroxyethyl betaine. Examples of nonionic surfactants include polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl esters, polyoxyethylene alkylamines, polyoxyethylene alkylamides, polyoxyethylene propylene block polymers, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and ethylene oxide adducts of acetylene alcohol. Examples of anionic surfactants include polyoxyethylene alkyl ether acetates, dodecylbenzenesulfonates, laurates, and salts of polyoxyethylene alkyl ether sulfates. These may be used alone or in combination of two or more.

[0057] The silicone surfactant is not particularly limited and can be appropriately selected depending on the purpose. Examples include side-chain-modified polydimethylsiloxane, both-end-modified polydimethylsiloxane, one-end-modified polydimethylsiloxane, and both-end-modified side-chain polydimethylsiloxane. Polyether-modified silicone surfactants having polyoxyethylene groups or polyoxyethylene-polyoxypropylene groups as modifying groups are particularly preferred because they exhibit good properties as aqueous surfactants. Such surfactants may be appropriately synthesized or commercially available products, such as those available from BYK-Chemie Co., Ltd., Shin-Etsu Chemical Co., Ltd., Dow Corning Toray Silicone Co., Ltd., Nippon Emulsion Co., Ltd., and Kyoeisha Chemical Co., Ltd. The polyether-modified silicone surfactant is not particularly limited and can be appropriately selected depending on the purpose. For example, it may be a surfactant represented by general formula (S-1) in which a polyalkylene oxide structure is introduced into the Si moiety side chain of dimethylpolysiloxane. [ka] (In the general formula (S-1), m, n, a, and b each independently represent an integer, R represents an alkylene group, and R' represents an alkyl group.) As the polyether-modified silicone surfactant, commercially available products can be used, such as KF-618, KF-642, KF-643 (Shin-Etsu Chemical Co., Ltd.), EMALEX-SS-5602, SS-1906EX (Nihon Emulsion Co., Ltd.), FZ-2105, FZ-2118, FZ-2154, FZ-2161, FZ-2162, FZ-2163, FZ-2164 (Dow Corning Toray Silicone Co., Ltd.), BYK-33, BYK-387 (BYK-Chemie Co., Ltd.), TSF4440, TSF4452, TSF4453 (Toshiba Silicone Co., Ltd.).

[0058] As the fluorine-based surfactant, a compound having 2 to 16 fluorine-substituted carbon atoms is preferred, and a compound having 4 to 16 fluorine-substituted carbon atoms is more preferred. Examples of fluorine-based surfactants include perfluoroalkyl phosphate ester compounds, perfluoroalkyl ethylene oxide adducts, and polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups in the side chains. Among these, polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups in the side chains are preferred because they have low foaming properties, and fluorine-based surfactants represented by general formula (F-1) and general formula (F-2) are particularly preferred. [ka] In the compound represented by the above general formula (F-1), m is preferably an integer of 0 to 10, and n is preferably an integer of 0 to 40 in order to impart water solubility. [ka] In the compound represented by the general formula (F-2), Y is H or CmF 2m+1 where m is an integer from 1 to 6, or CH2CH(OH)CH2-CmF 2m+1 where m is an integer between 4 and 6, or CpH 2p+1 where p is an integer from 1 to 19, n is an integer from 1 to 6, and a is an integer from 4 to 14. As the fluorine-based surfactant, commercially available products may be used, such as Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, and S-145 (all manufactured by Asahi Glass Co., Ltd.); Fullard FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, and FC-431 (all manufactured by Sumitomo 3M Limited); Megafa F-470, F-1405, F-474 (all manufactured by Dainippon Ink and Chemicals, Inc.); Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR, Capstone FS-30, FS-31, FS-3100, FS-34, FS-35 (all manufactured by Chemours); FT-110, FT- 250, FT-251, FT-400S, FT-150, FT-400SW (all manufactured by Neos Corporation), Polyfox PF-136A, PF-156A, PF-151N, PF-154, PF-159 (manufactured by Omnova), Unidyne DSN-403N (manufactured by Daikin Industries, Ltd.), and among these, FS-3100, FS-34, FS-300 manufactured by Chemours Corporation, FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW manufactured by Neos Corporation, Polyfox PF-151N manufactured by Omnova, and Unidyne DSN-403N manufactured by Daikin Industries, Ltd. are particularly preferred in terms of achieving good print quality, particularly color development, penetration into paper, wettability, and significant improvements in dye leveling.

[0059] The content of the surfactant in the ink is not particularly limited and can be selected appropriately depending on the purpose. However, from the viewpoint of achieving excellent wettability and ejection stability and improving image quality, the content is preferably from 0.001% by mass to 5% by mass, and more preferably from 0.05% by mass to 5% by mass, relative to the total amount of ink.

[0060] <Antifoaming agent> The defoaming agent is not particularly limited, and examples thereof include silicone defoaming agents, polyether defoaming agents, fatty acid ester defoaming agents, and the like. These may be used alone or in combination of two or more. Among these, silicone defoaming agents are preferred because of their excellent defoaming effect.

[0061] <Antiseptic and mildew-proof agent> The antiseptic and mildew-proof agent is not particularly limited, and examples thereof include 1,2-benzisothiazolin-3-one.

[0062] <Rust inhibitor> The rust inhibitor is not particularly limited, and examples thereof include acid sulfite, sodium thiosulfate, and the like.

[0063] <pH adjuster> The pH adjuster is not particularly limited as long as it can adjust the pH to 7 or higher, and examples thereof include amines such as diethanolamine and triethanolamine.

[0064] <<Method for manufacturing ink>> Examples of the method for manufacturing ink include a method in which water, coloring material, resin, and other components are dispersed or dissolved in an aqueous medium and stirred and mixed. The dispersion can be carried out, for example, by a sand mill, a homogenizer, a ball mill, a paint shaker, ultrasonic dispersion, or the like. The stirring and mixing can be carried out, for example, by a stirrer using ordinary stirring blades, a magnetic stirrer, a high-speed disperser, or the like.

[0065] <<Printed material>> In this embodiment, the printed material that can be used is not particularly limited, but a low-permeability printed material is preferred. The low-permeability printed material preferably has a support and a coating layer on at least one surface of the support, and may further have other layers as needed. Note that the surface having the coating layer becomes the printing surface.

[0066] In this embodiment, the low-permeability printing substrate has a transfer rate of 2 mL / m2 of pure water to the surface of the printing substrate having a coating layer at 25°C for a contact time of 100 ms as measured by a dynamic scanning absorptiometer. 2 More than 35mL / m 2 The following is the result. If the amount of pure water transferred during a contact time of 100 ms is too small, beading may occur more easily, whereas if it is too large, the ink dot diameter after printing may become too small compared to the desired diameter.

[0067] In addition, the amount of pure water transferred to the coated surface of the low-permeability substrate was 3 mL / m2 at 25°C for a contact time of 400 ms as measured by a dynamic scanning absorptivity meter. 2 More than 40mL / m 2 The following is the result. If the amount of transfer at a contact time of 400 ms is too small, the drying will be insufficient and spur marks may easily occur, whereas if it is too large, the gloss of the image area after drying may easily decrease.

[0068] Here, a dynamic scanning absorptometer (DSA, Journal of the Japan Paper and Pulp Technology Association, Vol. 48, May 1994, pp. 88-92, Kuga Shigenori) is an apparatus that can accurately measure the amount of liquid absorbed in an extremely short period of time. The dynamic scanning absorptivity meter automates measurements by directly reading the absorption rate from the movement of the meniscus in the capillary, scanning the absorptive head in a spiral over a disk-shaped sample, automatically changing the scanning rate according to a preset pattern, and taking measurements at only the required number of points on one sample. The liquid supply head for the paper sample is connected to the capillary via a Teflon tube, and the position of the meniscus in the capillary is automatically read by an optical sensor. Specifically, the transferred amount of pure water or ink is measured using a dynamic scanning absorptivity meter (K350 series D type, manufactured by Kyowa Seiko Co., Ltd.). The transfer amounts at contact times of 100 ms and 400 ms can be determined by interpolation from the measured values ​​of the transfer amounts at contact times close to each contact time.

[0069] -Support- The support is not particularly limited and can be appropriately selected depending on the purpose. Examples include sheet-like materials such as paper mainly made of wood fibers and nonwoven fabric mainly made of wood fibers and synthetic fibers. The paper is not particularly limited and can be appropriately selected from known types depending on the purpose, for example, wood pulp, recycled paper pulp, etc. Examples of wood pulp include bleached hardwood kraft pulp (LBKP), bleached softwood kraft pulp (NBKP), NBSP, LBSP, GP, and TMP. Raw materials for recycled paper pulp include white paper, ruled white paper, cream white paper, card paper, special white paper, medium white paper, imitation paper, color white paper, Kent paper, white art paper, special high-grade paper, special high-grade paper, newspapers, and magazines, as shown in the standard quality specification table for recycled paper of the Waste Paper Recycling Promotion Center. Specifically, examples of such waste paper include information-related paper such as uncoated computer paper, thermal paper, and pressure-sensitive printer paper; office waste paper such as PPC paper; coated paper such as art paper, coated paper, lightly coated paper, and matte paper; uncoated paper such as fine paper, colored fine paper, notebook paper, letter paper, wrapping paper, fancy paper, medium-quality paper, newsprint, recycled paper, super-sized wrapping paper, imitation paper, pure white roll paper, and milk cartons; and other paper and cardboard waste paper, including chemical pulp paper and high-yield pulp-containing paper. These may be used alone or in combination of two or more types. Recycled paper pulp is generally produced through a combination of the following four processes: (1) Disintegration is the process of treating waste paper with mechanical force and chemicals in a pulper to break it into fibers and remove the printing ink from the fibers. (2) Dust removal involves removing foreign matter (such as plastic) and debris contained in waste paper using screens, cleaners, etc. (3) Deinking involves removing the printing ink that has been stripped from the fibers using a surfactant by flotation or washing. (4) Bleaching uses oxidation and reduction to increase the whiteness of fibers. When recycled paper pulp is mixed, the mixed ratio of recycled paper pulp to the total pulp is preferably 40% or less to prevent curling after printing.

[0070] As the internal filler used in the support, for example, a conventionally known white pigment is used. Examples of white pigments include white inorganic pigments such as light calcium carbonate, heavy calcium carbonate, kaolin, clay, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, calcium silicate, magnesium silicate, synthetic silica, aluminum hydroxide, alumina, lithopone, zeolite, magnesium carbonate, and magnesium hydroxide; and organic pigments such as styrene-based plastic pigments, acrylic-based plastic pigments, polyethylene, microcapsules, urea resins, and melamine resins. These may be used alone or in combination of two or more. Examples of internal sizing agents used in papermaking for the support include neutral rosin-based sizing agents used in neutral papermaking, alkenyl succinic anhydride (ASA), alkyl ketene dimer (AKD), and petroleum resin-based sizing agents. These may be used alone or in combination of two or more. Among these, neutral rosin sizing agents and alkenyl succinic anhydride are preferred. Alkyl ketene dimers have a high sizing effect, so only small amounts need to be added. However, this can be undesirable from the viewpoint of transportability during inkjet printing, as it reduces the coefficient of friction of the surface of the recording paper (printed material), making it slippery.

[0071] -Coating layer- The coating layer contains a pigment and a binder (binding agent), preferably contains a surfactant, and may further contain other components as required.

[0072] As the pigment, an inorganic pigment or a combination of an inorganic pigment and an organic pigment can be used. Examples of inorganic pigments include kaolin, talc, heavy calcium carbonate, light calcium carbonate, calcium sulfite, amorphous silica, titanium white, magnesium carbonate, titanium dioxide, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide, chlorite, etc. These may be used alone or in combination of two or more. Among these, kaolin is particularly preferred because it has excellent gloss development and can provide a texture similar to that of paper for offset printing. Examples of kaolin include delaminated kaolin, calcined kaolin, engineered kaolin obtained by surface modification, etc. Among these, in consideration of gloss development, it is preferable that kaolin having a particle size distribution in which the proportion of particles having a diameter of 2 μm or less is 80% by mass or more accounts for 50% by mass or more of the total kaolin. The amount of kaolin added is preferably 50 parts by mass or more per 100 parts by mass of binder. When the amount added is 50 parts by mass or more, good glossiness can be obtained. There is no particular upper limit on the amount added, but considering the fluidity of kaolin, particularly its viscosity increase under high shear force, it is more preferably 90 parts by mass or less from the viewpoint of coating suitability. The dry adhesion amount of cationic organic compounds is 0.3 g / m 2 More than 2.0g / m 2 The following is preferred: Dry adhesion amount of cationic organic compound is 0.3g / m 2 If the above ratio is satisfied, the image density is improved and feathering is reduced.

[0073] The surfactant is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, etc. Among these, nonionic surfactants are preferred. By adding a surfactant, the water resistance of the image is improved, the image density is increased, and bleeding is improved. Examples of nonionic surfactants include ethylene oxide adducts of higher alcohols, ethylene oxide adducts of alkylphenols, ethylene oxide adducts of fatty acids, ethylene oxide adducts of polyhydric alcohol fatty acid esters, ethylene oxide adducts of higher aliphatic amines, ethylene oxide adducts of fatty acid amides, ethylene oxide adducts of fats and oils, ethylene oxide adducts of polypropylene glycols, fatty acid esters of glycerol, fatty acid esters of pentaerythritol, fatty acid esters of sorbitol and sorbitan, fatty acid esters of sucrose, alkyl ethers of polyhydric alcohols, fatty acid amides of alkanolamines, etc. These may be used alone or in combination of two or more. The polyhydric alcohol is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include glycerol, trimethylolpropane, pentaerythritol, sorbitol, sucrose, etc. Furthermore, with regard to the ethylene oxide adducts, those in which part of the ethylene oxide is substituted with an alkylene oxide such as propylene oxide or butylene oxide are also effective as long as water solubility is maintained. The substitution rate is preferably 50% or less. The HLB (hydrophilicity / lipophilicity ratio) of the nonionic surfactant is preferably 4-15, and more preferably 7-13. The amount of surfactant added is preferably 0 to 10 parts by mass, more preferably 0.1 to 1.0 parts by mass, per 100 parts by mass of the cationic organic compound.

[0074] If necessary, other components may be added to the coating layer. Examples of other components include additives such as alumina powder, pH adjusters, preservatives, and antioxidants.

[0075] The method for forming the coating layer is not particularly limited and can be appropriately selected depending on the purpose. For example, the coating layer can be formed by impregnating or applying a coating layer liquid onto a support. The method of impregnation or application of the coating layer liquid is not particularly limited and can be appropriately selected depending on the purpose. For example, coating can be performed using various coating machines such as a conventional size press, a gate roll size press, a film transfer size press, a blade coater, a rod coater, an air knife coater, or a curtain coater. However, from the viewpoint of cost, impregnation or application can be performed using a conventional size press, a gate roll size press, a film transfer size press, or the like installed on a paper machine, followed by on-machine finishing. The amount of coating liquid to be applied is not particularly limited and can be selected appropriately depending on the purpose. 2 More than 20g / m 2 Less than 1g / m is preferred 2 More than 15g / m 2 The following is more preferred: After the impregnation or coating, the material may be dried as needed. The drying temperature in this case is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 100°C or higher and 250°C or lower.

[0076] The low-permeability printing substrate may further include a backing layer on the back surface of the support, other layers between the support and the coating layer, or between the support and the backing layer, and a protective layer on the coating layer. Each of these layers may be a single layer or multiple layers.

[0077] <<Ink storage container>> The ink container includes an ink storage section that stores the ink of this embodiment, and may further include other members appropriately selected as necessary. The shape, structure, size, material, etc. of the ink storage container can be selected appropriately depending on the purpose. For example, a container having an ink storage section formed from an aluminum laminate film, a resin film, etc., or a large-capacity ink tank is suitable.

[0078] <<Printing device, printing method>> The ink of this embodiment can be suitably used in various printing devices that use an inkjet printing method, such as printers, facsimile machines, copying machines, printer / fax / copier combination machines, and three-dimensional modeling devices. The printing device and printing method refer to a device capable of ejecting ink or various treatment liquids onto a substrate, and a method of printing using such a device. The substrate refers to an object onto which ink or various treatment liquids can be attached, even if only temporarily. This printing device can include not only the head portion that ejects ink, but also means for feeding, transporting, and discharging the printing material, as well as other devices called pre-processing devices and post-processing devices. The printing apparatus and printing method may have a heating means used in the heating step and a drying means used in the drying step. The heating means and drying means include, for example, means for heating and drying the printed surface and back surface of the printing substrate. The heating means and drying means are not particularly limited, but for example, a hot air heater or an infrared heater can be used. Heating and drying can be carried out before, during, or after printing. Furthermore, the printing device and printing method are not limited to those that visualize meaningful images such as letters and figures using ink. For example, they also include those that form patterns such as geometric designs and those that create three-dimensional images. Furthermore, unless otherwise specified, the printing device includes both a serial type device in which the ejection head moves and a line type device in which the ejection head does not move. Furthermore, this printing device includes not only desktop types, but also wide-width printing devices that can print on A0-sized substrates, and continuous feed printers that can use continuous paper wound into a roll as the substrate. An example of a printing device will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view of the device. FIG. 2 is a perspective view of a main tank. An image forming device 400, as an example of a printing device, is a serial image forming device. A mechanism unit 420 is provided within an exterior 401 of the image forming device 400. Each ink storage unit 411 of the main tanks 410 (410k, 410c, 410m, 410y) for each color of black (K), cyan (C), magenta (M), and yellow (Y) is formed from a packaging material such as aluminum laminate film. The ink storage unit 411 is housed in a storage container case 414 made of, for example, plastic. As a result, the main tanks 410 are used as ink cartridges for each color. On the other hand, a cartridge holder 404 is provided at the back of the opening when the cover 401c of the device main body is opened. A main tank 410 is detachably attached to the cartridge holder 404. This allows each ink outlet 413 of the main tank 410 to communicate with the ejection head 434 for each color via the supply tube 436 for each color, making it possible to eject ink from the ejection head 434 onto the printing substrate.

[0079] The ink can be used in a wide variety of ways, including but not limited to inkjet printing, blade coating, gravure coating, bar coating, roll coating, dip coating, curtain coating, slide coating, die coating, and spray coating. [Example]

[0080] Examples of the present invention will be described below, but the present invention is not limited to these examples in any way.

[0081] First, the methods for measuring various physical properties in the following Production Examples, Synthesis Examples, Preparation Examples, Examples, and Comparative Examples will be described.

[0082] <Molecular weight> Apparatus: GPC (manufactured by Tosoh Corporation), detector: RI, measurement temperature: 40°C Mobile phase: tetrahydrofuran, flow rate: 0.45 mL / min. The number average molecular weight (Mn), weight average molecular weight (Mw), and molecular weight distribution (Mw / Mn) are the number average molecular weight, weight average molecular weight, and molecular weight distribution measured by GPC (gel permeation chromatography) using a calibration curve prepared using polystyrene samples of known molecular weight as the standard. Columns with exclusion limits of 60,000, 20,000, and 10,000 connected in series were used.

[0083] <Melting point (Tm), crystallization temperature (Tc)> 4 g of the resin dispersion (resin emulsion) was placed in a container so that it was spread evenly, and then dried at 70°C for 1 hour, then at 130°C for 1 hour, and then further dried under reduced pressure at 130°C to obtain a solid sample for measurement. The thermal properties of each measurement sample were measured using a differential scanning calorimeter (DSC) (Q2000 manufactured by TA Instruments) under the following conditions. Specifically, the measurements were performed as follows. (Measurement conditions) Sample container: Aluminum sample pan (with lid) Sample amount: 5 mg Reference aluminum crucible (empty container) Atmosphere: Nitrogen (flow rate 50 mL / min) Starting temperature: -80℃ Heating rate: 10℃ / min End temperature: 130℃ Holding time: 1min Cooling rate: 10℃ / min End temperature: -80℃ Holding time: 5min Heating rate: 10℃ / min End temperature: 130℃ Measurements were carried out under the above measurement conditions, and a graph of "amount of heat absorbed and generated" versus "temperature" was created. The melting point was determined as the temperature at the apex of the melting (endothermic) peak obtained in the second heating process. The heat of fusion was calculated by considering the endothermic region in the heating process as the melting region. The crystallization peak temperature was defined as the temperature at the top of the crystallization (exothermic) peak obtained during the temperature drop. The heat of crystallization was calculated by considering the heat generated during the temperature drop as the crystallization region.

[0084] <Volume average particle size> The volume average particle size was measured by dynamic light scattering using a zeta potential particle size measurement system (ELSZ-1000, manufactured by Otsuka Electronics Co., Ltd.). First, 0.2 g of resin dispersion (resin emulsion) was taken, then ion-exchanged water was added to dilute it 100 times, and a part of the obtained solution was placed in a quartz cell and set in a sample holder. Then, measurements were performed under the conditions of a temperature of 25°C, dust cut (number of times: 5, upper: 5, lower: 100), and cumulative number of times: 70, to obtain the volume average particle size of the solid content in the ink.

[0085] <Production example of black pigment dispersion> 11.2 g of styrene, 2.8 g of acrylic acid, 12 g of lauryl methacrylate, 4 g of polyethylene glycol methacrylate, 4 g of styrene macromer, and 0.4 g of mercaptoethanol were mixed and heated to 65°C. Next, a mixed solution of 100.8 g of styrene, 25.2 g of acrylic acid, 108 g of lauryl methacrylate, 36 g of polyethylene glycol methacrylate, 60 g of hydroxyethyl methacrylate, 36 g of styrene macromer, 3.6 g of mercaptoethanol, 2.4 g of azobismethylvaleronitrile, and 18 g of methyl ethyl ketone was added dropwise to the flask over 2.5 hours. After the dropwise addition, a mixed solution of 0.8 g of azobismethylvaleronitrile and 18 g of methyl ethyl ketone was added dropwise to the flask over 0.5 hours. After aging at 65°C for 1 hour, 0.8 g of azobismethylvaleronitrile was added, and the mixture was further aged for 1 hour. After the reaction was completed, 364 g of methyl ethyl ketone was added to the flask, and 800 g of polymer solution A with a solid content of 50% was obtained. Next, 28 g of polymer solution A, 42 g of carbon black (Black Pearls 1000, manufactured by Cabot Corporation), 13.6 g of a 1 mol / L aqueous potassium hydroxide solution, 20 g of methyl ethyl ketone, and 13.6 g of water were thoroughly stirred and then kneaded using a roll mill. The resulting paste was added to 200 g of pure water and thoroughly stirred, after which the methyl ethyl ketone was removed using an evaporator. The mixture was then pressure filtered through a polyvinylidene fluoride membrane filter with an average pore size of 5 μm, and the water content was adjusted so that the solids concentration was 20%, yielding a black pigment dispersion with a solids concentration of 20%.

[0086] <Synthesis of crystalline polyester polyol> -Synthesis Example 1 of Crystalline Polyester Polyol- A 5L four-neck flask equipped with a nitrogen inlet tube, dehydration tube, stirrer, and thermocouple was charged with 1,4-butanediol as the diol and sebacic acid as the dicarboxylic acid, with a diol to dicarboxylic acid molar ratio of OH / COOH = 1.40. After thoroughly purging the reactor with nitrogen gas, 300 ppm of titanium tetraisopropoxide (relative to the monomer) was added. The mixture was heated to 200°C under a nitrogen gas flow for approximately 4 hours, then to 230°C over 2 hours, and reacted until no water was discharged. The mixture was then reacted for 1 hour under a reduced pressure of 10 to 30 mmHg, yielding "Crystalline Polyester Polyol 1." The resulting resin had an acid value (AV) of 2.1 mgKOH / g, a hydroxyl value (OHV) of 86 mgKOH / g, a melting point (Tm) of 61.8°C, a crystallization temperature (Tc) of 44.3°C, a number average molecular weight (Mn) of 2,200, and a weight average molecular weight (Mw) of 3,800.

[0087] -Synthesis Example 2 of Crystalline Polyester Polyol- A 5L four-neck flask equipped with a nitrogen inlet tube, dehydration tube, stirrer, and thermocouple was charged with 1,4-butanediol as the diol and dodecanedioic acid as the dicarboxylic acid, with a diol to dicarboxylic acid molar ratio of OH / COOH = 1.40. After thoroughly purging the reactor with nitrogen gas, 300 ppm of titanium tetraisopropoxide (relative to the monomer) was added. The mixture was heated to 200°C under a nitrogen gas flow for approximately 4 hours, then to 230°C over 2 hours, and the reaction was continued until no water was discharged. The reaction was then continued for 1 hour under a reduced pressure of 10 to 30 mmHg, yielding "Crystalline Polyester Polyol 2." The resulting resin had an acid value (AV) of 1.8 mg KOH / g, a hydroxyl value (OHV) of 73 mg KOH / g, a melting point (Tm) of 72.3°C, a crystallization temperature (Tc) of 53.8°C, a number average molecular weight (Mn) of 2,800, and a weight average molecular weight (Mw) of 4,300.

[0088] -Synthesis Example 3 of Crystalline Polyester Polyol- A 5L four-neck flask equipped with a nitrogen inlet tube, dehydration tube, stirrer, and thermocouple was charged with ethylene glycol as the diol and sebacic acid as the dicarboxylic acid, with a diol to dicarboxylic acid molar ratio of OH / COOH = 1.40. After thoroughly purging the reactor with nitrogen gas, 300 ppm of titanium tetraisopropoxide (relative to the monomer) was added. The mixture was heated to 200°C under a nitrogen gas flow for approximately 4 hours, then to 230°C over 2 hours, and reacted until no water was discharged. The mixture was then reacted for 1 hour under a reduced pressure of 10 to 30 mmHg, yielding "Crystalline Polyester Polyol 3." The resulting resin had an acid value (AV) of 2.4 mg KOH / g, a hydroxyl value (OHV) of 90 mg KOH / g, a melting point (Tm) of 83.2°C, a crystallization temperature (Tc) of 65.1°C, a number average molecular weight (Mn) of 2,500, and a weight average molecular weight (Mw) of 4,000.

[0089] -Synthesis Example 4 of Crystalline Polyester Polyol- A 5L four-neck flask equipped with a nitrogen inlet tube, dehydration tube, stirrer, and thermocouple was charged with ethylene glycol as the diol and dodecanedioic acid as the dicarboxylic acid, with a diol to dicarboxylic acid molar ratio of OH / COOH = 1.40. After thoroughly purging the reactor with nitrogen gas, 300 ppm of titanium tetraisopropoxide (relative to the monomer) was added. The temperature was raised to 200°C under a nitrogen gas flow for approximately 4 hours, then to 230°C over 2 hours, and the reaction was continued until no water was discharged. The reaction was then continued for 1 hour under a reduced pressure of 10 to 30 mmHg, yielding "Crystalline Polyester Polyol 4." The resulting resin had an acid value (AV) of 2.2 mg KOH / g, a hydroxyl value (OHV) of 74 mg KOH / g, a melting point (Tm) of 89.6°C, a crystallization temperature (Tc) of 72.1°C, a number average molecular weight (Mn) of 2,800, and a weight average molecular weight (Mw) of 4,300.

[0090] <Preparation of crystalline polyester-based urethane resin> -Crystalline polyester urethane resin preparation example 1- A 1 L separable flask equipped with a stirrer, a thermometer, and a reflux condenser was charged with 33.0 g of crystalline polyester polyol 1, 1.5 g of 1,4-butanediol, 0.8 g of trimethylolpropane, 3.0 g of 2,2-bis(hydroxymethyl)propionic acid, 23.0 g of 4,4'-dicyclohexylmethane diisocyanate, 2.3 g of triethylamine, and 34.6 g of methyl ethyl ketone as an organic solvent while introducing nitrogen. One drop of catalyst (tin(II) di(2-ethylhexanoate)) was added, and the mixture was then heated to 60°C and refluxed for 2 hours. The temperature was then lowered to 40°C and maintained at that temperature. After confirming the NCO% present in the system, 119.4g of water was slowly added while stirring at 500 rpm to form fine particles. After heating and stirring for 30 minutes, 3.0g of isophoronediamine was added and heated and stirred for 1 hour. Finally, the methyl ethyl ketone was removed to obtain "Crystalline Polyester Urethane Resin Emulsion 1." The results of measuring the volume average particle size of the resulting resin emulsion are shown in Table 1. Table 1 also shows the results of measuring the melting point of the resin obtained after drying the resulting resin emulsion.

[0091] -Crystalline polyester urethane resin production example 2- A 1 L separable flask equipped with a stirrer, a thermometer, and a reflux condenser was charged with 37.0 g of crystalline polyester polyol 2, 2.5 g of 1,6-hexanediol, 0.7 g of trimethylolpropane, 2.9 g of 2,2-bis(hydroxymethyl)propionic acid, 18.6 g of isophorone diisocyanate, 2.2 g of triethylamine, and 33.7 g of methyl ethyl ketone as an organic solvent while introducing nitrogen. One drop of catalyst (tin(II) di(2-ethylhexanoate)) was added, and the temperature was then raised to 60°C and refluxed for 2 hours. After that, the temperature was reduced to 40°C. The temperature was lowered to 0.5°C and maintained at that temperature. After confirming the NCO% present in the system, 116.2 g of water was slowly added while stirring at 500 rpm to form fine particles. After heating and stirring for 30 minutes, 1.5 g of N,N'-dimethylethylenediamine was added and heated and stirred for 1 hour. Finally, the methyl ethyl ketone was removed to obtain "Crystalline Polyester Urethane Resin Emulsion 2." The results of measuring the volume average particle size of the resulting resin emulsion are shown in Table 1. Table 1 also shows the results of measuring the melting point of the resin obtained after drying the resulting resin emulsion.

[0092] -Crystalline polyester urethane resin preparation example 3- A 1 L separable flask equipped with a stirrer, a thermometer, and a reflux condenser was charged with 40.0 g of crystalline polyester polyol 3, 0.9 g of 3-methyl-1,5-pentanediol, 0.3 g of trimethylolpropane, 2.6 g of 2,2-bis(hydroxymethyl)propionic acid, 17.2 g of isophorone diisocyanate, 1.0 g of triethylamine, and 34.3 g of methyl ethyl ketone as an organic solvent while introducing nitrogen, and one drop of catalyst (tin(II) di(2-ethylhexanoate)) was added, and then the temperature was raised to 60°C and refluxed for 2 hours. Thereafter, the temperature was lowered to 40°C, and the temperature was The temperature was maintained at 25°C. After confirming the NCO% present in the system, 118.2 g of water was slowly added while stirring at 500 rpm to form fine particles. After heating and stirring for 30 minutes, 2.6 g of isophoronediamine was added and heated and stirred for 30 minutes. 1.0 g of triethylamine was then added and heated and stirred for 30 minutes. Finally, the methyl ethyl ketone was removed to obtain "Crystalline Polyester Urethane Resin Emulsion 3." The results of measuring the volume average particle size of the resulting resin emulsion are shown in Table 1. Table 1 also shows the results of measuring the melting point of the resin obtained after drying the resulting resin emulsion.

[0093] -Crystalline polyester urethane resin preparation example 4- A 1 L separable flask equipped with a stirrer, a thermometer, and a reflux condenser was charged with 36.0 g of crystalline polyester polyol 4, 1.9 g of 3-methyl-1,5-pentanediol, 0.7 g of trimethylolpropane, 2.8 g of 2,2-bis(hydroxymethyl)propionic acid, 18.3 g of isophorone diisocyanate, 2.0 g of triethylamine, and 33.6 g of methyl ethyl ketone as an organic solvent while introducing nitrogen. One drop of catalyst (tin(II) di(2-ethylhexanoate)) was added, and the mixture was then heated to 60°C and refluxed for 2 hours. The temperature was then lowered to 40°C and maintained at that temperature. After confirming the NCO% present in the system, 116.0 g of water was slowly added while stirring at 500 rpm to form fine particles. After heating and stirring for 30 minutes, 2.8 g of isophoronediamine was added and heated and stirred for 30 minutes. Finally, the methyl ethyl ketone was removed to obtain "Crystalline Polyester Urethane Resin Emulsion 4." The results of measuring the volume average particle size of the resulting resin emulsion are shown in Table 1. Table 1 also shows the results of measuring the melting point of the resin obtained after drying the resulting resin emulsion.

[0094] -Crystalline polyester urethane resin preparation example 5- A 1 L separable flask equipped with a stirrer, thermometer, and reflux condenser was charged with 34.0 g of crystalline polyester polyol 1, 1.7 g of 1,6-hexanediol, 1.3 g of trimethylolpropane, 1.7 g of 2,2-bis(hydroxymethyl)propionic acid, 20.3 g of isophorone diisocyanate, 0.7 g of triethylamine, and 32.5 g of methyl ethyl ketone as an organic solvent while introducing nitrogen. One drop of catalyst (tin(II) di(2-ethylhexanoate)) was added, and the mixture was then heated to 60°C and refluxed for 2 hours. The temperature was then lowered to 40°C and maintained at that temperature. After confirming the NCO% present in the emulsion, 112.0 g of water was slowly added while stirring at 500 rpm to form fine particles. After heating and stirring for 30 minutes, 1.4 g of N,N'-dimethylethylenediamine was added and heated and stirred for 30 minutes. 0.6 g of triethylamine was then added and heated and stirred for 30 minutes. Finally, the methyl ethyl ketone was removed to obtain "Crystalline Polyester Urethane Resin Emulsion 5." The volume average particle size of the resulting resin emulsion was measured and is shown in Table 1. The melting point of the resin obtained after drying the resulting resin emulsion was also measured and is shown in Table 1.

[0095] -Crystalline polyester urethane resin preparation example 6- A 1 L separable flask equipped with a stirrer, a thermometer, and a reflux condenser was charged with 24.0 g of crystalline polyester polyol 1, 2.0 g of 1,4-butanediol, 3.0 g of trimethylolpropane, 3.9 g of 2,2-bis(hydroxymethyl)propionic acid, 25.5 g of isophorone diisocyanate, 3.0 g of triethylamine, and 33.6 g of methyl ethyl ketone as an organic solvent while introducing nitrogen. One drop of catalyst (tin(II) di(2-ethylhexanoate)) was added, and the temperature was then raised to 60°C and refluxed for 2 hours. The temperature was lowered to 40°C and maintained at that temperature. After confirming the NCO% present in the system, 115.8 g of water was slowly added while stirring at 500 rpm to form fine particles. After heating and stirring for 30 minutes, 3.0 g of isophoronediamine was added and heated and stirred for 1 hour. Finally, the methyl ethyl ketone was removed to obtain "Crystalline Polyester Urethane Resin Emulsion 6." The results of measuring the volume average particle size of the resulting resin emulsion are shown in Table 1. Table 1 also shows the results of measuring the melting point of the resin obtained after drying the resulting resin emulsion.

[0096] -Crystalline polyester urethane resin preparation example 7- A 1 L separable flask equipped with a stirrer, a thermometer, and a reflux condenser was charged with 35.0 g of crystalline polyester polyol 1, 1.6 g of 1,4-butanediol, 0.8 g of 1,2,6-hexanetriol, 3.2 g of 2,2-bis(hydroxymethyl)propionic acid, 24.4 g of 4,4'-dicyclohexylmethane diisocyanate, 2.5 g of triethylamine, and 35.9 g of methyl ethyl ketone as an organic solvent while introducing nitrogen. One drop of catalyst (tin(II) di(2-ethylhexanoate)) was added, and the mixture was then heated to 60°C and refluxed for 2 hours. The temperature was then lowered to 40°C and maintained at that temperature. After confirming the NCO% present in the system, 115.8 g of water was slowly added while stirring at 500 rpm to form fine particles. After heating and stirring for 30 minutes, 1.6 g of N,N'-dimethylethylenediamine was added and heated and stirred for 1 hour. Finally, the methyl ethyl ketone was removed to obtain "Crystalline Polyester Urethane Resin Emulsion 7." The results of measuring the volume average particle size of the resulting resin emulsion are shown in Table 2. Table 2 also shows the results of measuring the melting point of the resin obtained after drying the resulting resin emulsion.

[0097] -Crystalline polyester urethane resin preparation example 8- A 1 L separable flask equipped with a stirrer, a thermometer, and a reflux condenser was charged with 33.0 g of crystalline polyester polyol 1, 2.0 g of 1,6-hexanediol, 0.5 g of glycerin, 3.0 g of 2,2-bis(hydroxymethyl)propionic acid, 23.0 g of 4,4'-dicyclohexylmethane diisocyanate, 2.3 g of triethylamine, and 34.7 g of methyl ethyl ketone as an organic solvent while introducing nitrogen, and one drop of catalyst (tin(II) di(2-ethylhexanoate)) was added, followed by heating to 60°C and refluxing for 2 hours. The temperature was then lowered to 40°C and maintained at that temperature. After confirming the NCO% present in the system, 119.8 g of water was slowly added while stirring at 500 rpm to form fine particles. After heating and stirring for 30 minutes, 3.0 g of isophoronediamine was added and heated and stirred for 1 hour. Finally, the methyl ethyl ketone was removed to obtain "Crystalline Polyester Urethane Resin Emulsion 8." The results of measuring the volume average particle size of the resulting resin emulsion are shown in Table 2. Table 2 also shows the results of measuring the melting point of the resin obtained after drying the resulting resin emulsion.

[0098] -Crystalline polyester urethane resin preparation example 9- Into a 1 L separable flask equipped with a stirrer, a thermometer, and a reflux condenser, 36.0 g of crystalline polyester polyol 1, 2.2 g of 1,4-butanediol, 3.3 g of 2,2-bis(hydroxymethyl)propionic acid, 21.3 g of isophorone diisocyanate, 2.5 g of triethylamine, and 34.7 g of methyl ethyl ketone as an organic solvent were charged while introducing nitrogen, and one drop of catalyst (tin(II) di(2-ethylhexanoate)) was added, and then the temperature was raised to 60°C and refluxed for 2 hours. Thereafter, the temperature was lowered to 40°C, and the temperature was The temperature was maintained at 25°C. After checking the NCO% present in the system, 119.7 g of water was slowly added while stirring at 500 rpm to form fine particles. After heating and stirring for 30 minutes, 1.7 g of N,N'-dimethylethylenediamine was added and the mixture was heated and stirred for 1 hour. Finally, the methyl ethyl ketone was removed to obtain "Crystalline Polyester Urethane Resin Emulsion 9." The volume average particle size of the resulting resin emulsion was measured and is shown in Table 2. The melting point of the resin obtained after drying the resulting resin emulsion was also measured and is shown in Table 2.

[0099] -Crystalline polyester urethane resin preparation example 10- A 1 L separable flask equipped with a stirrer, a thermometer, and a reflux condenser was charged with 34.0 g of crystalline polyester polyol 1, 1.3 g of 1,3-propanediol, 0.8 g of trimethylolpropane, 3.1 g of 2,2-bis(hydroxymethyl)propionic acid, 20.1 g of isophorone diisocyanate, 2.4 g of triethylamine, and 33.6 g of methyl ethyl ketone as an organic solvent while introducing nitrogen. One drop of catalyst (tin(II) di(2-ethylhexanoate)) was added, and the temperature was then raised to 60°C and refluxed for 2 hours. The temperature was lowered to 40°C and maintained at that temperature. After confirming the NCO% present in the system, 115.8 g of water was slowly added while stirring at 500 rpm to form fine particles. After heating and stirring for 30 minutes, 3.1 g of isophoronediamine was added and heated and stirred for 1 hour. Finally, the methyl ethyl ketone was removed to obtain "Crystalline Polyester Urethane Resin Emulsion 10." The results of measuring the volume average particle size of the resulting resin emulsion are shown in Table 2. Table 2 also shows the results of measuring the melting point of the resin obtained after drying the resulting resin emulsion.

[0100] -Crystalline polyester urethane resin preparation example 11- A 1 L separable flask equipped with a stirrer, a thermometer, and a reflux condenser was charged with 32.0 g of crystalline polyester polyol 1, 2.7 g of 1,8-octanediol, 0.4 g of trimethylolpropane, 3.2 g of 2,2-bis(hydroxymethyl)propionic acid, 22.3 g of 4,4'-dicyclohexylmethane diisocyanate, 2.2 g of triethylamine, and 34.1 g of methyl ethyl ketone as an organic solvent while introducing nitrogen, and one drop of catalyst (tin(II) di(2-ethylhexanoate)) was added, followed by heating to 60°C and refluxing for 2 hours. The temperature was then lowered to 40°C and maintained at that temperature. After confirming the NCO% present in the system, 117.5g of water was slowly added while stirring at 500 rpm to form fine particles. After heating and stirring for 30 minutes, 2.9g of isophoronediamine was added and heated and stirred for 1 hour. Finally, the methyl ethyl ketone was removed to obtain "Crystalline Polyester Urethane Resin Emulsion 11." The results of measuring the volume average particle size of the resulting resin emulsion are shown in Table 2. Table 2 also shows the results of measuring the melting point of the resin obtained after drying the resulting resin emulsion.

[0101] -Crystalline polyester urethane resin preparation example 12- In a 1 L separable flask equipped with a stirrer, a thermometer, and a reflux condenser, 45.0 g of crystalline polyester polyol 1, 2.2 g of 2,2-bis(hydroxymethyl)propionic acid, 16.6 g of 4,4'-dicyclohexylmethane diisocyanate, 1.7 g of triethylamine, and 35.5 g of methyl ethyl ketone as an organic solvent were charged while introducing nitrogen, and one drop of catalyst (tin(II) di(2-ethylhexanoate)) was added. Thereafter, the temperature was raised to 60°C and refluxed for 2 hours. Thereafter, the temperature was lowered to 40°C, and the temperature was The temperature was maintained at 40°C. After confirming the NCO% present in the system, 122.5 g of water was slowly added while stirring at 500 rpm to form fine particles. After heating and stirring for 30 minutes, 2.2 g of isophoronediamine was added and heated and stirred for 1 hour. Finally, the methyl ethyl ketone was removed to obtain "Crystalline Polyester Urethane Resin Emulsion 12." The volume average particle size of the resulting resin emulsion was measured and is shown in Table 3. The melting point of the resin obtained after drying the resulting resin emulsion was also measured and is shown in Table 3.

[0102] -Crystalline polyester urethane resin preparation example 13- A 1 L separable flask equipped with a stirrer, a thermometer, and a reflux condenser was charged with 12.0 g of crystalline polyester polyol 1, 5.5 g of 1,4-butanediol, 1.1 g of trimethylolpropane, 4.9 g of 2,2-bis(hydroxymethyl)propionic acid, 37.7 g of 4,4'-dicyclohexylmethane diisocyanate, 3.8 g of triethylamine, and 34.3 g of methyl ethyl ketone as an organic solvent while introducing nitrogen. One drop of catalyst (tin(II) di(2-ethylhexanoate)) was added, and the mixture was then heated to 60°C and refluxed for 2 hours. The temperature was lowered to 40°C and maintained at that temperature. After confirming the NCO% present in the system, 118.3 g of water was slowly added while stirring at 500 rpm to form fine particles. After heating and stirring for 30 minutes, 2.5 g of N,N'-dimethylethylenediamine was added and heated and stirred for 1 hour. Finally, the methyl ethyl ketone was removed to obtain "Crystalline Polyester Urethane Resin Emulsion 13." The volume average particle size of the resulting resin emulsion was measured and is shown in Table 3. The melting point of the resin obtained after drying the resulting resin emulsion was also measured and is shown in Table 3.

[0103] -Crystalline polyester urethane resin preparation example 14- A 1 L separable flask equipped with a stirrer, a thermometer, and a reflux condenser was charged with 34.0 g of crystalline polyester polyol 1, 0.5 g of 1,4-butanediol, 0.3 g of trimethylolpropane, 4.2 g of 2,2-bis(hydroxymethyl)propionic acid, 18.1 g of isophorone diisocyanate, 3.2 g of triethylamine, and 32.2 g of methyl ethyl ketone as an organic solvent while introducing nitrogen. One drop of catalyst (tin(II) di(2-ethylhexanoate)) was added, and the temperature was then raised to 60°C and refluxed for 2 hours. The temperature was lowered to 40°C and maintained at that temperature. After confirming the NCO% present in the system, 111.1 g of water was slowly added while stirring at 500 rpm to form fine particles. After heating and stirring for 30 minutes, 2.8 g of isophoronediamine was added and heated and stirred for 1 hour. Finally, the methyl ethyl ketone was removed to obtain "Crystalline Polyester Urethane Resin Emulsion 14." The volume average particle size of the resulting resin emulsion was measured and is shown in Table 3. The melting point of the resin obtained after drying the resulting resin emulsion was also measured and is shown in Table 3.

[0104] -Crystalline polyester urethane resin preparation example 15- A 1 L separable flask equipped with a stirrer, a thermometer, and a reflux condenser was charged with 33.0 g of crystalline polyester polyol 1, 4.5 g of 1,12-dodecanediol, 3.0 g of 2,2-bis(hydroxymethyl)propionic acid, 23.0 g of 4,4'-dicyclohexylmethane diisocyanate, 2.3 g of triethylamine, and 35.1 g of methyl ethyl ketone as an organic solvent while introducing nitrogen. One drop of catalyst (tin(II) di(2-ethylhexanoate)) was added, and the mixture was then heated to 60°C and refluxed for 2 hours. After that, the temperature was reduced to 40°C. The temperature was lowered and maintained at that temperature. After confirming the NCO% present in the system, 120.9 g of water was slowly added while stirring at 500 rpm to form fine particles. After heating and stirring for 30 minutes, 1.5 g of N,N'-dimethylethylenediamine was added and heated and stirred for 1 hour. Finally, the methyl ethyl ketone was removed to obtain "Crystalline Polyester Urethane Resin Emulsion 15." The results of measuring the volume average particle size of the resulting resin emulsion are shown in Table 3. Table 3 also shows the results of measuring the melting point of the resin obtained after drying the resulting resin emulsion.

[0105] <Preparation of polyether urethane resin> -Example of polyether urethane resin production- In a 1 L separable flask equipped with a stirrer, a thermometer, and a reflux condenser, 42.0 g of PTMG1000 (manufactured by Wako Pure Chemical Industries, Ltd.), 2.7 g of 2,2-bis(hydroxymethyl)propionic acid, 17.2 g of isophoronediamine, 2.0 g of triethylamine, and 34.7 g of methyl ethyl ketone as an organic solvent were charged while introducing nitrogen, and one drop of catalyst (tin(II) di(2-ethylhexanoate)) was added. The mixture was then heated to 60°C and refluxed for 2 hours. The temperature was then lowered to 40°C, and the mixture was then refluxed at that temperature. The NCO% in the system was confirmed, and 119.7 g of water was slowly added while stirring at 500 rpm to form fine particles. After heating and stirring for 30 minutes, 2.6 g of isophoronediamine was added and heated and stirred for 1 hour. Finally, the methyl ethyl ketone was removed to obtain a "polyether-based urethane resin emulsion." The results of measuring the volume average particle size of the resulting resin emulsion are shown in Table 3. Table 3 also shows the results of measuring the melting point of the resin obtained after drying the resulting resin emulsion.

[0106] <Ink preparation and printing> Example 1 An ink was prepared according to the following formulation, the pH was adjusted, and then the ink was filtered through a membrane filter with an average pore size of 5 μm to produce Ink 1. Using the prepared Ink 1, printing was carried out on a substrate (Lumia Art Gloss 90 gsm (manufactured by STORA ENSO)) using the methods described in the various evaluations below. -Ink formula- Black pigment dispersion: 20.0 parts by weight Crystalline polyester urethane resin emulsion 1: 23.0 parts by mass Propylene glycol: 15.0 parts by mass 3-Methoxy-3-methyl-1-butanol: 10.0 parts by mass 2-Ethyl-1,3-hexanediol: 2.0 parts by mass Surfactant (TEGO (registered trademark) WET270) (manufactured by Evonik Industries): 0.5 parts by mass Preservative (Proxel LV, manufactured by Avecia): 0.05 parts by weight Rust inhibitor (1,2,3-benzotriazole): 0.05 parts by mass Ion-exchanged water: remaining amount (total: 100 parts by mass) -Printed material (Lumi Art Gloss 90gsm)- Lumi Art Gloss 90gsm (manufactured by STORA ENSO) has a coating layer on both sides, approximately 10 to 15 μm thick, consisting mainly of modified starch, styrene-butadiene copolymer, and calcium carbonate. At 25°C, Lumi Art Gloss 90gsm transferred 2.3 mL / m2 of pure water over a contact time of 100 ms, as measured using a dynamic scanning absorptivity meter (K350 Series D, manufactured by Kyowa Seiko Co., Ltd.). 2 and the amount of pure water transferred in a contact time of 400 ms is 4.4 mL / m 2 is.

[0107] Examples 2 to 11 Inks 2 to 11 were prepared in the same manner as in Example 1, except that in Example 1, "crystalline polyester-based urethane resin emulsion 1" was changed to "crystalline polyester-based urethane resin emulsions 2 to 11," and printing was performed in the same manner as in Example 1.

[0108] Example 12 Printing was carried out in the same manner as in Example 1, except that the printing substrate was changed from Lumi Art Gloss 90 gsm (manufactured by STORA ENSO) to SWORD iJET 4.3 Gloss (manufactured by Mitsubishi Paper Mills). -SWORD iJET 4.3 Gloss- The SWORD iJET 4.3 Gloss (manufactured by Mitsubishi Paper Mills) had a coating layer of approximately 10 to 15 μm thick on both the front and back sides, consisting mainly of modified starch, polyvinyl alcohol, styrene-butadiene copolymer, calcium carbonate, and kaolin. Furthermore, the amount of pure water transferred to the SWORD iJET 4.3 Gloss (manufactured by Mitsubishi Paper Mills) at 25°C over a contact time of 100 ms was measured using a dynamic scanning absorptivity meter (K350 Series D, manufactured by Kyowa Seiko Co., Ltd.) at 5.2 mL / m². 2 The amount of pure water transferred during a contact time of 400 ms is 9.6 mL / m 2 is.

[0109] (Comparative Examples 1 to 4) Inks 12 to 15 were prepared in the same manner as in Example 1, except that in Example 1, "crystalline polyester-based urethane resin emulsion 1" was changed to "crystalline polyester-based urethane resin emulsions 12 to 15," and printing was performed in the same manner as in Example 1.

[0110] (Comparative Example 5) Ink 16 was prepared in the same manner as in Example 1, except that the "crystalline polyester-based urethane resin emulsion 1" in Example 1 was changed to "polyether-based urethane resin emulsion," and printing was carried out in the same manner as in Example 1.

[0111] <Various evaluations> The "blocking resistance," "abrasion resistance under high load," and "water resistance" were measured and evaluated according to the following procedures. The results are shown in Tables 1 to 3.

[0112] -Blocking resistance- The prepared ink was filled into an inkjet printer (IPSiO GXe5500, manufactured by Ricoh), and a 2 cm square solid image was printed on the substrate at 1200 x 1200 dpi, followed by heating and drying in a dryer at 100°C for 3 minutes. Immediately after heating and drying, an unprinted substrate was placed on top of the solid image. Furthermore, a pressure of 0.5 kg / cm was applied to the solid image. 2 The solid image was then evaluated for blocking using the following criteria: A was the best, and B or higher was the acceptable range. [Evaluation criteria] A: No blocking. B: Slight blocking (slight transfer to interleaf) C: Complete blocking (transfer area clearly visible on the slip sheet)

[0113] -Abrasion resistance under high load- The ink thus prepared was loaded into an inkjet printer (IPSiO GXe5500, Ricoh), and a solid image was printed on a substrate at 1200 x 1200 dpi. The image was then dried in a dryer at 100°C for 3 minutes. The resulting solid image was subjected to a dry rub fastness test in accordance with the Japanese Industrial Standards (JIS) L0849 using a Gakushin-type rub fastness tester. However, to evaluate abrasion resistance under high loads, the load was changed from 2N to 5N. After the test, the color of the transferred OD onto cotton fabric was measured and evaluated according to the following criteria. A was the best rating, and D or higher was the acceptable range. [Evaluation criteria] A: The transfer OD of the cotton fabric after the test is less than 0.05 B: The transfer OD of the cotton fabric after the test is 0.05 or more and less than 0.10 C: The transfer OD of the cotton fabric after the test is 0.10 or more and less than 0.20 D: The transfer OD of the cotton fabric after the test is 0.20 or more and less than 0.30 E: Transfer OD of cotton fabric after test is 0.30 or more

[0114] -water resistance- The ink thus prepared was loaded into an inkjet printer (IPSiO GXe5500, Ricoh), and a solid image was printed on a substrate at 1200 x 1200 dpi. The image was then dried in a dryer at 100°C for 3 minutes. The resulting solid image was subjected to a rub fastness test (wet rub) using a Gakushin-type rub fastness tester in accordance with Japanese Industrial Standards (JIS) L0849. The white cotton cloth used for rubbing was moistened with water until it was approximately 100% wet. A load of 2N was applied. After the test, the color of the transferred OD onto the cotton cloth was measured and evaluated based on the following criteria. A was the best rating, and B or higher was acceptable. A: The transfer OD of the cotton fabric after the test is less than 0.10 B: The transfer OD of the cotton fabric after the test is 0.10 or more and less than 0.30 C: Transfer OD of cotton fabric after test is 0.30 or more

[0115] [Table 1]

[0116] [Table 2]

[0117] [Table 3] [Explanation of symbols]

[0118] 400 Image forming device 401 Exterior of image forming device 401c Device body cover 404 Cartridge Holder 410 Main Tank 410k, 410c, 410m, 410y Main tanks for black (K), cyan (C), magenta (M), and yellow (Y) 411 Ink storage unit 413 Ink outlet 414 Storage container case 420 Mechanism Department 434 Discharge Head 436 Supply Tube [Prior art documents] [Patent documents]

[0119] [Patent Document 1] Japanese Patent Application Publication No. 2014-201622 [Patent Document 2] Japanese Patent Application Publication No. 2020-143189 [Patent Document 3] Japanese Patent Publication No. 2021-014574

Claims

1. A printing device having an ink storage container containing ink and an ejection means for ejecting the stored ink. The ink contains a crystalline polyester urethane resin, The polyester urethane resin has a melting peak temperature (Tm) of 30°C or higher and 100°C or lower, the polyester urethane resin has a structure derived from a crystalline polyester polyol, a structure derived from a nonionic short-chain polyol having from 2 to 10 carbon atoms, and a structure derived from an ionic short-chain polyol having from 2 to 6 carbon atoms; In the polyester urethane resin, the following formula "B / (A+B+C)" represents the relationship between the number of moles A of urethane groups derived from hydroxyl groups of the crystalline polyester polyol, the number of moles B of urethane groups derived from hydroxyl groups of the nonionic short-chain polyol having from 2 to 10 carbon atoms, and the number of moles C of urethane groups derived from hydroxyl groups of the ionic short-chain polyol having from 2 to 6 carbon atoms. The formula is 0.15 or more and 0.50 or less. A printing device characterized by:

2. 2. The printing device according to claim 1, wherein the structure derived from the nonionic short-chain polyol having 2 to 10 carbon atoms comprises a structure derived from a nonionic short-chain polyol having 4 to 6 carbon atoms.

3. The printing device according to claim 1, wherein the structure derived from the nonionic short-chain polyol having 2 to 10 carbon atoms includes a structure derived from a bifunctional nonionic short-chain polyol having 2 to 10 carbon atoms and a structure derived from a trifunctional nonionic short-chain polyol having 3 to 6 carbon atoms.

4. The printing device according to claim 3 , wherein the structure derived from the trifunctional nonionic short-chain polyol having 3 to 6 carbon atoms comprises a structure derived from a trifunctional nonionic short-chain polyol having 6 carbon atoms.

5. 5. The printing device according to claim 4, wherein the structure derived from the trifunctional nonionic short-chain polyol having six carbon atoms comprises a structure derived from trimethylolpropane.

6. 6. A printing device according to claim 3, wherein the polyester urethane resin has a relationship between the number of moles D of urethane groups derived from the hydroxyl groups of the bifunctional nonionic short-chain polyol having 2 to 10 carbon atoms and the number of moles E of urethane groups derived from the hydroxyl groups of the trifunctional nonionic short-chain polyol having 3 to 6 carbon atoms, expressed by the following formula, "E / (D+E)", which is 0.10 or more and 0.40 or less.

7. the polyester urethane resin is in the form of resin particles in the ink; The printing device according to claim 1 , wherein the resin particles have a volume average particle size of 30 nm or more and 120 nm or less.

8. A printing method comprising a discharging step of discharging ink onto a printing substrate using the printing device according to any one of claims 1 to 7.

9. The printing substrate has a support and a coating layer provided on at least one side of the support, and the amount of pure water transferred to the surface of the printing substrate having the coating layer measured at 25°C with a contact time of 100 ms using a dynamic scanning absorptiometer is 2 ml / m ２ 35ml / m or more ２ or less, and the amount of pure water transferred to the surface of the printing substrate having the coating layer during a contact time of 400 ms is 3 ml / m ２ More than 40ml / m ２ 9. The printing method according to claim 8, wherein:

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