JP2020179520A - Liquid ejection device, liquid ejection method, printing apparatus, printing method, and control method for glossiness of printed image - Google Patents

Abstract

To provide a liquid ejection device adaptable to glossiness control of both of low glossiness (mat-like) and high glossiness, and allowing for resolution of adhesiveness defect and blur arising when both a color ink and a clear ink are simultaneously used.SOLUTION: The liquid ejection device is provided that includes: a liquid housing portion in which liquid is housed; a liquid ejection head ejecting the liquid to a printing target; and heating means heating the printing target, the liquid is an ink set including a clear ink containing a resin, and water, and a color ink containing a resin, a coloring material, and water, the resin of the clear ink and the resin of the color ink are resins including a common constituent, the liquid ejection device has a low glossiness printing mode which imparts low glossiness, and a high glossiness printing mode which imparts high glossiness. The liquid ejection device satisfies formula: Tmatte>Tgloss where Tmatte°C denotes the temperature of the heating means when printing by a low glossiness printing mode and Tgloss°C denotes the temperature of the heating means when printing by a high glossiness printing mode.SELECTED DRAWING: None

Description

The present invention relates to a device for discharging a liquid, a method for discharging a liquid, a printing device, a printing method, and a method for controlling glossiness of a printed image.

Conventionally, in order to improve durability such as light resistance, water resistance, and abrasion resistance in industrial applications such as advertisements and signboards, and packaging materials such as foods, beverages, and daily necessities, for example, impermeable records such as plastic films have been recorded. The medium is being used. Various inks and inkjet recording devices used for such recording media have been developed.

In such an inkjet recording device, one having a gloss control function has been developed. For example, a liquid injection device including a liquid injection head capable of injecting ink containing thermoplastic resin particles from a nozzle toward a landing target and a heating means for heating ink droplets landing on the landing target has been proposed. (See, for example, Patent Document 1). In the heating means of the liquid injection device of the present proposal, the degree of film formation on the surface of the ink droplet is controlled by heating at a film formation control temperature corresponding to the minimum film formation temperature at which film formation on the surface of the ink droplet starts. doing.

Further, in an inkjet recording device using clear ink (UV clear ink) that is cured by irradiation with ultraviolet rays, it has been proposed to control the gloss to a matte or glossy tone by controlling the amount of irradiation light (for example, a patent). Reference 2).

The present invention provides a device that can control both low gloss (matte) and high gloss, and discharge a liquid that can eliminate poor adhesion and bleeding that occur when color ink and clear ink are used in combination. With the goal.

The device for ejecting the liquid of the present invention as a means for solving the above-mentioned problems includes a liquid accommodating portion for accommodating the liquid, a liquid ejection head for ejecting the liquid to the printed matter, and a heating means for heating the printed matter. A device that discharges a liquid having the above, wherein the liquid is an ink set having a clear ink containing a resin and water and a color ink containing a resin, a coloring material, and water. A resin containing a component common to the ink resin and the color ink resin, and the device for discharging the liquid is a printing mode for imparting low gloss in a low gloss printing mode and a printing mode for imparting high gloss. It has a high-gloss printing mode, the temperature of the heating means when printing in the low-gloss printing mode is T _matte [° C.], and the temperature of the heating means when printing in the high-gloss printing mode is T _gloss. When [° C.], the following equation, T _matte > T _gloss , is satisfied.

According to the present invention, there is provided a device that can control gloss of both low gloss (matte tone) and high gloss, and discharge a liquid that can eliminate poor adhesion and bleeding that occur when color ink and clear ink are used in combination. be able to.

FIG. 1 is a schematic view showing an example of an image forming apparatus that implements the image forming method of the present invention. FIG. 2 is a perspective explanatory view showing an example of the main tank of the image forming apparatus of FIG. FIG. 3 is a schematic view showing an example inside the main body of the inkjet printing apparatus.

Hereinafter, a device for discharging a liquid, a method for discharging a liquid, a printing device, a printing method, and a method for controlling glossiness of a printed image according to the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments shown below, and can be modified within the range conceivable by those skilled in the art, such as other embodiments, additions, modifications, and deletions. However, as long as the action and effect of the present invention are exhibited, it is included in the scope of the present invention.

(Device for discharging liquid, method for discharging liquid, printing device, and printing method)
The device for ejecting the liquid of the present invention is an apparatus for ejecting a liquid having a liquid accommodating portion for accommodating the liquid, a liquid ejection head for ejecting the liquid to the printed matter, and a heating means for heating the printed matter. The liquid is an ink set having a clear ink containing resin and water and a color ink containing resin, a coloring material, and water, and the resin of the clear ink and the resin of the color ink. Is a resin containing a common component, and the device for discharging the liquid has a low-gloss printing mode, which is a printing mode for imparting low gloss, and a high-gloss printing mode, which is a printing mode for imparting high gloss. _Assuming that the temperature of the heating means when printing in the low-gloss printing mode is T _matte [° C.] and the temperature of the heating means when printing in the high-gloss printing mode is T _gloss [° C.], the following equation, T _Matte > T _gloss , and other means as needed.

The printing apparatus of the present invention is a printing apparatus having an ink accommodating portion for accommodating ink, an ink ejection head for ejecting the ink to an object to be printed, and a heating means for heating the object to be printed. An ink set having a clear ink containing resin, and water, and a color ink containing resin, a coloring material, and water, and contains a component common to the resin of the clear ink and the resin of the color ink. The printing apparatus is a resin, and has a low-gloss printing mode, which is a printing mode for imparting low gloss, and a high-gloss printing mode, which is a printing mode for imparting high gloss, and when printing in the low-gloss printing mode. When the temperature of the heating means is T _matte [° C.] and the temperature of the heating means when printing in the high-gloss printing mode is T _gloss [° C.], the following equation, T _matte > T _gloss , is satisfied, and further. Have other means as needed.

The method for ejecting a liquid of the present invention includes a printing step of ejecting a liquid onto a printed matter using a liquid ejection head to provide a printing layer, and a heating step of heating the printed matter to be printed by a heating means. The liquid is an ink set having a clear ink containing resin and water and a color ink containing resin, a coloring material, and water, and the resin of the clear ink and the above. The resin of the color ink is a resin containing a common component, and the method of discharging the liquid is a low-gloss printing mode, which is a printing mode for imparting low gloss, and a high-gloss printing mode, which is a printing mode for imparting high gloss. The temperature of the heating means when printing in the low-gloss printing mode is T _matte [° C], and the temperature of the heating means when printing in the high-gloss printing mode is T _gloss [° C]. , The following equation, T _matte > T _gloss , and if necessary, other steps are included.

The printing method of the present invention is a printing method including a printing step of ejecting ink to a printed matter by using a ejection head to provide a printing layer, and a heating step of heating the printed matter to be printed by a heating means. The ink is an ink set having a clear ink containing a resin and water and a color ink containing a resin, a coloring material, and water, and the resin of the clear ink and the resin of the color ink are common. The printing method has a low-gloss printing mode, which is a printing mode for imparting low gloss, and a high-gloss printing mode, which is a printing mode for imparting high gloss, in the low-gloss printing mode. _Assuming that the temperature of the heating means at the time of printing is T _matte [° C.] and the temperature of the heating means at the time of printing in the high gloss printing mode is T _gloss [° C.], the following equation, T _matte > T _gloss , And further include other steps as needed.

In the prior art described in Patent Document 1, when the glossiness is controlled by an ink containing thermoplastic resin particles, the resin content in the ink must be increased in order to improve the leveling property on the surface of the ejected ink coating film. However, this makes it easier for the ink to thicken in a short time. Further, since the drying of the ink in the head nozzle is promoted by heating the recording medium, there is a problem that instability of ejection and clogging of the nozzle are likely to occur.
Further, in Patent Document 1, a film on the surface of ink droplets is formed by heating a color ink containing a coloring material at a film formation control temperature corresponding to the minimum film formation temperature at which film formation on the surface of ink droplets starts. The glossiness is adjusted by controlling the degree of conversion. However, the color ink containing the color material does not have a sufficient difference in glossiness as compared with the clear ink not containing the color material, and has a problem that it cannot cope with both low gloss (matte tone) and high gloss control. is there.

Further, in the conventional technique described in Patent Document 2, the UV clear ink has a strong odor and the odor remains in the printed matter, so that it is not suitable for the printed matter for indoor use. Therefore, the installation location of the inkjet printing device also requires an environment in which exhaust can be exhausted, and the installation location is limited. In addition, UV clear ink requires an ultraviolet irradiation device, which causes problems such as an increase in size and cost of the device.

The present inventors have studied diligently, using a clear ink containing a resin as a liquid, a low-gloss printing mode which is a printing mode for imparting low gloss, and a high-gloss printing mode which is a printing mode for imparting high gloss. The present invention has been found that the above problems can be solved by making the temperature at which the printed matter is heated different from each other and making the temperature of the printed matter in the low-gloss printing mode higher than the temperature of the printed matter in the high-gloss printing mode. It came to. According to the present invention, it is possible to control both low gloss (matte tone) and high gloss, and stable discharge is possible.

Further, in the prior art, when the clear ink is ejected onto the color ink, the adhesiveness between the color ink and the clear ink is poor, and the clear ink may be peeled off. Further, when the clear ink is ejected onto the color ink that is not completely dried, there is a problem that bleeding causes bleeding.
As a result of diligent studies by the present inventors, the above problems are solved by using a resin containing a common component in the clear ink resin and the color ink resin in the ink set of the clear ink and the color ink. The present invention was reached with the finding that it can be done. According to the present invention, it is possible to eliminate poor adhesion and bleeding between the color ink and the clear ink.

In the device for discharging the liquid and the method for discharging the liquid of the present invention, it is preferable to use an inkjet method, and according to the present invention, both low gloss (matte) and high gloss can be controlled and stable. It is possible to provide a printing device and a printing method capable of ejecting. A printing device can be mentioned as an example of a device for discharging a liquid.
The high-gloss printing mode is a printing mode that imparts high gloss, and the surface of the printed matter becomes smooth and high-gloss. The low-gloss print mode is a print mode that imparts low gloss, and has a matte tone with fine irregularities on the surface of the printed matter to provide low gloss. The high-gloss print mode may also be referred to as a "gloss-gloss print mode". The low gloss printing mode is sometimes referred to as a "matte gloss printing mode".

The device for discharging the liquid and the method for discharging the liquid of the present invention use clear ink containing a resin and control the gloss of both low gloss (matte tone) and high gloss by controlling the heating temperature.
When low gloss is applied, printing is performed at a higher temperature during printing than in the high gloss mode. Due to the high temperature during printing, after the clear ink containing resin lands on the printed matter, the wet spread of the dots is suppressed, so that the coalescence of adjacent dots is suppressed and the height of the dot sphere (pile height). High dots are formed. These dots form surface irregularities and impart low gloss.

On the other hand, when high gloss is applied, printing is performed at a lower temperature than in the low gloss mode. Since the temperature at the time of printing is low, the clear ink containing the resin lands on the printed matter and then the dots are wetted and spread, so that the coalescence of adjacent dots is promoted and a smooth surface is formed. As a result, high gloss is imparted.
As described above, according to the present embodiment, it is possible to cope with both low gloss (matte tone) and high gloss control.

In the apparatus for discharging the liquid of the present invention, the temperature T (° C.) of the heating means is T _matte (° C.) in the low gloss printing mode and T _matte (° C.) in the high gloss printing mode. _{When gloss} (° C.), it is preferable that the following equation, T _matte > T _gloss , is satisfied, T _matte > T _gloss ≧ 10 ° C. is satisfied, and T _matte > T _gloss ≧ 20 ° C. is more preferable.
The condition of T _matte > T _gloss may be satisfied at the heating temperature of the heating means during printing, and is preferably satisfied at the heating temperature of the heating means before printing.
In the present embodiment, since the wet spread of the ink coating film surface occurs at the moment of landing, it is considered that the heating after printing has little influence on the surface shape. Therefore, the heating temperature of the heating means after printing does not necessarily have to satisfy the condition of T _matte > T _gloss .

Further, in the present embodiment, the heating temperature of the heating means is preferably T _matte −T _gloss ≧ 10 [° C.]. In this case, in the low-gloss printing mode, the heating temperature is relatively higher, the wetting spread of the dots can be further suppressed, the dots having a high pile height can be formed, and a surface having large irregularities can be formed. On the other hand, in the high-gloss printing mode, the heating temperature is relatively lower, the wetting and spreading of dots can be promoted, and the coalescence of adjacent dots can form a smooth surface.
It should be noted that even under the condition of T _matte −T _gloss ≧ 10 [° C.], it is preferable that the temperature is satisfied at the heating temperature of the heating means during printing, and the heating temperature of the heating means before printing is also satisfied. Is more preferable.

The T _matte [° C.] is preferably 50 ° C. or higher, more preferably 50 ° C. or higher and 80 ° C. or lower. Further, the T _gloss [° C.] is preferably 70 ° C. or lower, more preferably 60 ° C. or lower. By setting such a temperature range, a large change in gloss can be realized in each printing mode using clear ink.

The landing area of the clear ink may also be referred to as a printing unit or the like. Further, the area where the clear ink does not land may be referred to as a non-printing portion or the like. Further, the portion where the clear ink has landed and, if necessary, has been heated and dried after landing is also referred to as a printing layer or the like.

In the present invention, when the print rate of the _matte print image printed in the low gloss print mode is D _matte [%] and the print rate of the gloss print image printed in the high gloss print mode is D _gloss [%], D _{gloss is used.} > D _matte is preferable, and D _gloss −D _matte > 10 [%] is more preferable.
Since a smooth surface is more likely to be formed when the printing rate is high, it is preferable to obtain an image having a high printing rate in the high gloss printing mode. On the other hand, in the low-gloss printing mode, when the printing rate is high, coalescence of adjacent dots occurs and surface irregularities are less likely to be formed. Therefore, it is preferable to obtain an image having a low printing rate.

Here, the printing rate means the following.
Printing rate (%) = number of clear ink printing dots / (vertical resolution x horizontal resolution) x 100
(However, in the above formula, the "number of clear ink printing dots" is the number of dots actually printed with clear ink per unit area, and the "vertical resolution" and "horizontal resolution" are the resolutions per unit area, respectively.
When printing with clear inks superimposed so as to have the same dot position, the "clear ink printing dot number" is represented by the total number of dots actually printed with clear ink per unit area. )
The printing rate of 100% means the maximum weight of a single color ink with respect to a pixel.

As the print mode, for example, the low-gloss print mode and the high-gloss print mode are changed for each printed matter. The temperature setting of the heating means and the setting of the printing rate are changed depending on the printing mode.

<Liquid storage>
The liquid storage unit is also referred to as, for example, an ink storage unit, and stores ink that is a liquid.
The ink accommodating portion is not particularly limited as long as it is a member capable of accommodating ink, and examples thereof include an ink accommodating container and an ink tank.

The ink container includes the ink contained in the container, and further includes other members appropriately selected as needed.
The container is not particularly limited, and its shape, structure, size, material, etc. can be appropriately selected according to the purpose. For example, an ink bag made of an aluminum laminate film, a resin film, or the like can be used. At least those who have it can be mentioned.
Examples of the ink tank include a main tank and a sub tank.

<Liquid discharge head>
The liquid discharge head discharges a liquid onto a printed matter to form a printed layer. The liquid discharge head of the present embodiment has an individual liquid chamber communicating with a nozzle for discharging the liquid, a nozzle plate, a stimulus generating means, and the like, and the nozzle for discharging the liquid is formed in the nozzle plate. The nozzle plate preferably has a nozzle substrate and an ink-repellent film on the nozzle substrate.

The individual liquid chambers are a plurality of individual flow paths that are individually arranged corresponding to the plurality of nozzle holes provided in the nozzle plate and communicate with the nozzle holes, and are a pressurization chamber, an ink flow path, and pressurization. It may also be referred to as a liquid chamber, a pressure chamber, a discharge chamber, a liquid chamber, or the like.

The stimulus generating means is a means for generating a stimulus applied to the ink.
The stimulus in the stimulus generating means is not particularly limited and may be appropriately selected depending on the intended purpose, and examples thereof include heat (temperature), pressure, vibration, and light. These may be used alone or in combination of two or more. Among these, heat and pressure are preferably mentioned.

Examples of the stimulus generating means include a heating device, a pressurizing device, a piezoelectric element, a vibration generator, an ultrasonic oscillator, and a light. Specifically, as the stimulus generating means, a piezoelectric actuator such as a piezoelectric element, a thermal actuator using an electric heat conversion element such as a heat generating resistor to utilize a phase change due to boiling of an ink film, and a metal phase change due to a temperature change. Examples thereof include a shape memory alloy actuator using the above and an electrostatic actuator using an electrostatic force.

When the stimulus is "heat", heat energy corresponding to the recording signal is applied to the ink in the ink ejection head by using, for example, a thermal head. Examples thereof include a method in which bubbles are generated in the ink by the heat energy and the ink is ejected as droplets from the nozzle holes of the nozzle plate by the pressure of the bubbles.
When the stimulus is "pressure", for example, the piezoelectric element bends by applying a voltage to the piezoelectric element adhered to a position called the pressure chamber in the ink flow path in the ink ejection head. .. As a result, the volume of the pressure chamber contracts, and the ink is ejected as droplets from the nozzle hole of the ink ejection head.
Among these, the piezo method in which a voltage is applied to the piezo element to fly the ink is preferable.

<Heating means>
The heating means heats the printed matter.
Examples of the heating means include means for heating and drying the printed surface and the back surface of the recording medium as the printed matter, and examples thereof include an infrared heater, a hot air heater, and a heating roller. These may be used alone or in combination of two or more.

The method for heating the recording medium as the printed matter is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a method of bringing a heated fluid such as warm air into contact with a recording medium to which ink is applied as a heating means, a method of contacting a recording medium to which ink is applied and a heating member and heating by heat transfer, infrared rays or a distance. Examples thereof include a method of heating a recording medium to which ink is applied by irradiating with energy rays such as infrared rays.

In the heating step, the timing of heating before, during, or after printing can be appropriately changed as long as the relationship of T _matte > T _gloss is satisfied. The liquid can be applied to the heated recording medium by heating before and during printing, and the printed matter can be dried by heating after printing.

The heating time is not particularly limited as long as the surface temperature of the recording medium can be controlled to a desired temperature, and can be appropriately selected depending on the intended purpose. The heating time is preferably controlled by controlling the transport speed of the recording medium as the printed matter.

The heating temperature is not particularly limited and can be appropriately changed as long as the relationship of T _matte > T _gloss is satisfied. The preferred temperature is as described above.
Further, the heating temperatures before, during, and after printing may be different from each other.

<Liquid>
The liquid used in the present invention is an ink set having a clear ink containing resin and water and a color ink containing resin, a coloring material, and water.
It is a resin containing a component common to the resin of the clear ink and the resin of the color ink. When the resins contain common components, some of the components constituting the resin may be common, or all the components may be common.
The clear ink means a colorless and transparent ink that does not substantially contain a coloring material. Hereinafter, clear ink and color ink may be simply referred to as "ink".
The ink may contain an organic solvent or the like, and may contain an additive or the like such as a surfactant, if necessary.

<< Resin >>
The resin is not particularly limited and may be appropriately selected depending on the intended purpose. For example, polyurethane resin, polyester resin, acrylic resin, vinyl acetate resin, styrene resin, butadiene resin, styrene-butadiene resin, vinyl chloride resin, acrylic-styrene resin, acrylic-silicone resin and the like can be mentioned.

When producing ink, it is preferable to add it as resin particles made of these resins. The resin particles may be added to the ink in the form of a resin emulsion in which water is used as a dispersion medium. As the resin particles, those synthesized as appropriate may be used, or commercially available products may be used. These may be used individually by 1 type, or may be used in combination of 2 or more types of resin particles.

Among these, polyurethane resin is preferable. By adding the polyurethane resin, the coating film itself becomes tough when an ink film is formed using clear ink. As a result, it becomes easy to suppress that a part of the coating film is peeled off due to breakage inside the coating film or the surface state of the coating film is changed to change the color of the friction portion.

-Polyurethane resin-
Examples of the polyurethane resin include polyether polyurethane resin, polycarbonate polyurethane resin, polyester polyurethane resin and the like.

The polyurethane resin is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a polyurethane resin obtained by reacting a polyol with a polyisocyanate.

--Polycarbonate ---
Examples of the polyol include polyether polyols, polycarbonate polyols, polyester polyols and the like. These may be used alone or in combination of two or more.

--- Polyether polyol ---
Examples of the polyether polyol include those obtained by addition-polymerizing an alkylene oxide using at least one compound having two or more active hydrogen atoms as a starting material.

Examples of the compound having two or more active hydrogen atoms include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylolglycol, 1,3-butanediol, 1,4-butanediol, and 1,6-hexane. Examples thereof include diol, glycerin, trimethylolethane, and trimethylolpropane. These may be used alone or in combination of two or more.

Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, and tetrahydrofuran. These may be used alone or in combination of two or more.

The polyether polyol is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of obtaining an ink binder capable of imparting extremely excellent scratch resistance, polyoxytetramethylene glycol and polyoxy Propylene glycol is preferred. These may be used alone or in combination of two or more.

--- Polycarbonate polyol ---
Examples of the polycarbonate polyol that can be used in the production of the polyurethane resin include those obtained by reacting a carbonic acid ester with a polyol, and those obtained by reacting phosgene with bisphenol A and the like. These may be used alone or in combination of two or more.

Examples of the carbonic acid ester include methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, diphenyl carbonate and the like. These may be used alone or in combination of two or more.

Examples of the polyol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 1, 2-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 2,5-hexanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8 − Octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, hydroquinone, resorcin , Bisphenol-A, Bisphenol-F, 4,4'-biphenol and other relatively low molecular weight dihydroxy compounds; Polyether polyols such as polyethylene glycol, polypropylene glycol and polyoxytetramethylene glycol; Polyhexamethylene adipate, polyhexamethylene Examples thereof include polyester polyols such as succinate and polycaprolactone. These may be used alone or in combination of two or more.

--- Polyester polyol ---
Examples of the polyester polyol include those obtained by esterifying a low molecular weight polyol and a polycarboxylic acid, polyester obtained by ring-opening polymerization reaction of a cyclic ester compound such as ε-caprolactone, and copolymerization thereof. Examples include polyester. These may be used alone or in combination of two or more.

Examples of the low molecular weight polyol include ethylene glycol and propylene glycol. These may be used alone or in combination of two or more.

Examples of the polycarboxylic acid include succinic acid, adipic acid, sebacic acid, dodecandicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, anhydrides or ester-forming derivatives thereof. These may be used alone or in combination of two or more.

--Polyisocyanate ---
Examples of the polyisocyanate include aromatic diisocyanates such as phenylenediocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, and naphthalene diisocyanate; hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, and tetramethylxyli. Examples thereof include aliphatic or alicyclic diisocyanates such as range isocyanate and 2,2,4-trimethylhexamethylene diisocyanate. These may be used alone or in combination of two or more. Among these, alicyclic diisocyanate is preferable from the viewpoint of weather resistance.

Further, by using at least one kind of alicyclic diisocyanate, it becomes easy to obtain the desired coating film strength and scratch resistance.
Examples of the alicyclic diisocyanate include isophorone diisocyanate and dicyclohexylmethane diisocyanate.
The content of the alicyclic diisocyanate is preferably 60% by mass or more with respect to the total amount of the isocyanate compound.

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

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

Examples of the polyamine include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazin, isophoronediamine, 4,4'-dicyclohexylmethanediamine, and 1,4-cyclohexane. Diamines such as diamines; Polyamines such as diethylenetriamine, dipropylenetriamine, and triethylenetetramine; Hydradins such as hydrazine, N, N'-dimethylhydrazine, and 1,6-hexamethylenebishydrazine; dihydrazide succinate, dihydrazide adipic acid , Glutarate dihydrazide, sebacic acid dihydrazide, isophthalic acid dihydrazide and other dihydrazides. These may be used alone or in combination of two or more.

Examples of the other active hydrogen group-containing compound include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and hexamethylene glycol. Glycos such as saccharose, methylene glycol, glycerin, sorbitol; phenols such as bisphenol A, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenylsulfone, hydrogenated bisphenol A, hydroquinone, etc. Kind: Water and the like. These may be used alone or in combination of two or more as long as the storage stability of the ink is not deteriorated.

As the polyurethane resin, a polycarbonate polyurethane resin is preferable from the viewpoints of water resistance, heat resistance, abrasion resistance, weather resistance, and scratch resistance of images due to the high cohesive force of the carbonate group. In the case of the polycarbonate-based polyurethane resin, an ink suitable for a recorded material used in a harsh environment such as outdoor use can be obtained.

As the polyurethane resin, a commercially available product may be used, for example, U-coat UX-485 (polycarbonate-based polyurethane resin), U-coat UWS-145 (polyester-based polyurethane resin), Permarin UA-368T (polycarbonate-based polyurethane resin), and the like. Permarin UA-200 (polyester polyurethane resin) (all manufactured by Sanyo Kasei Kogyo Co., Ltd.) and the like can be mentioned. These may be used alone or in combination of two or more.

-Resin content-
The content of the resin contained in the clear ink is preferably 8% by mass or more, more preferably 8% by mass or more and 25% by mass or less. When the resin content is 8% by mass or more, low gloss and high gloss can be controlled with a small amount of clear ink. On the other hand, when the resin content is 25% by mass or less, it is possible to further suppress the deterioration of ink ejection stability.

Low gloss is realized by forming isolated dots with a high height of the dot sphere (pile height) and imparting irregularities on the surface. When the content of the resin in the clear ink is large, dots having a high pile height are likely to be formed, which is preferable from the viewpoint of easily imparting low gloss.
On the other hand, high gloss imparts smoothness by filling the unevenness of the surface with clear ink to form a smooth surface. In order to fill the unevenness of the surface with clear ink, it is preferable that the content of the resin in the clear ink is large because the unevenness of the surface can be filled with a small amount of clear ink and high gloss can be easily imparted.

In general commercially available inks, the composition of the resin contained is often unknown, but for example, the structure is constructed by using a thermal decomposition-gas chromatograph mass spectrometry (Py-GCMS) method, an FT-IR method, an NMR method, or the like. Can be analyzed. The conditions for resin analysis of ink by the Py-GCMS method are described below. This method is a method in which a small amount of sample is directly exposed to high temperature conditions to cause instantaneous thermal decomposition, the gas component generated at that time is guided to a GC / MS apparatus, and the spectrum is analyzed by structural estimation by library search. Is. The analysis conditions are described below as an example, but the conditions are not limited to the following. The analysis conditions can be changed at any time according to the composition and state of the analysis product, and the analysis can be performed while examining the optimum conditions.

-Device configuration / measurement conditions-
-GC / MS equipment: QP-5000 manufactured by Shimadzu Corporation
-Pyrolysis device: Py-3030D manufactured by Frontier Lab
-Evaluation conditions-
・ Heating temperature: 200 ℃
-Column: UA5L = 30 mL. D = 0.25mm Film = 0.25μm
-Column temperature rise: 50 ° C to 350 ° C (20 ° C / min temperature rise)
-Ionization method: EI method (70eV)
-Injection mode: Split (1: 100)

Different resins can be selected for the clear ink and the color ink, but from the viewpoint of improving the adhesiveness, resins containing common components (resins having the same monomer. For example, acrylic resins, urethane resins, etc. Etc.) are preferably contained in each of the clear ink and the color ink.

<< Water >>
The water is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include ion-exchanged water, ultrafiltration water, reverse osmosis water, pure water such as distilled water, and ultrapure water. .. These may be used alone or in combination of two or more.
The content of the water is not particularly limited, but when used as a water-based clear ink, it is preferably 0.1% by mass or more and 80% by mass or less, and 15% by mass or more and 60% by mass or less with respect to the total amount of ink. Is more preferable. Within the above range, the ejection stability can be improved and the image quality can be improved. Further, when it is 15% by mass or more, it is prevented that the viscosity becomes high, and the discharge stability is further improved. On the other hand, when it is 60% by mass or less, the wettability to the impermeable recording medium becomes preferable, and the image quality is further improved.

<< Organic Solvent >>
The ink may contain an organic solvent. The organic solvent is not particularly limited and may be appropriately selected depending on the intended purpose, and examples thereof include water-soluble organic solvents. The term "water-soluble" means that, for example, 5 g or more is dissolved in 100 g of water at 25 ° C.

Examples of the water-soluble organic solvent include ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, and 3 -Methyl-1,3-butanediol, 3-methoxy-3-methylbutanol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 1,6 -Hexanediol, glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-hexanediol, ethyl 1,2,4-butanetriol, 1,2,3-butanetriol, petriol, etc. Valuable alcohols: Polyvalent alcohols 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, propylene glycol monoethyl ether, and dipropylene glycol monomethyl ether. Alkyl ethers; Polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether; 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethyl Nitrogen-containing heterocyclic compounds such as imidazolidinone, ε-caprolactam and γ-butyrolactone; amides such as formamide, N-methylformamide, N, N-dimethylformamide; amines such as monoethanolamine, diethanolamine and triethylamine; dimethyl Sulfur-containing compounds such as sulfoxide, sulfolane and thiodiethanol; propylene carbonate, ethylene carbonate and the like can be mentioned. These may be used alone or in combination of two or more.

The content of the organic solvent in the ink is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10% by mass or more and 60% by mass or less from the viewpoint of ink drying property and ejection reliability. More preferably, it is 20% by mass or more and 60% by mass or less.

<Color material>
The color material used in the color ink is not particularly limited, and pigments and dyes can be used.
As the pigment, an inorganic pigment or an organic pigment can be used. These may be used alone or in combination of two or more. Moreover, you may use a mixed crystal.
As the pigment, for example, black pigment, yellow pigment, magenta pigment, cyan pigment, white pigment, green pigment, orange pigment, glossy color pigment such as gold or silver, metallic pigment and the like can be used.
As inorganic pigments, in addition to titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, and chrome yellow, carbon black produced by known methods such as contact method, furnace method, and thermal method. Can be used.
Examples of organic pigments include azo pigments and polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, and quinofuralone pigments). , Dye chelate (for example, basic dye type chelate, acidic dye type chelate, etc.), nitro pigment, nitroso pigment, aniline black and the like can be used. Among these pigments, those having a good affinity with a solvent are preferably used. In addition, resin hollow particles and inorganic hollow particles can also be used.
As a specific example of the pigment, for black, carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, or copper, iron (CI pigment black 11) , Metals such as titanium oxide, and organic pigments such as aniline black (CI pigment black 1).
Further, for color, C.I. I. Pigment Yellow 1,3,12,13,14,17,24,34,35,37,42 (yellow iron oxide), 53,55,74,81,83,95,97,98,100,101,104 , 108, 109, 110, 117, 120, 138, 150, 153, 155, 180, 185, 213, C.I. I. Pigment Orange 5, 13, 16, 17, 36, 43, 51, C.I. I. Pigment Red 1, 2, 3, 5, 17, 22, 23, 31, 38, 48: 2 (Permanent Red 2B (Ca)), 48: 3, 48: 4, 49: 1, 52: 2, 53: 1, 57: 1 (Brilliant Carmin 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81, 83, 88, 101 (Bengara), 104, 105, 106, 108 (Cadmium Red), 112, 114, 122 (quinacridone magenta), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 184, 185, 190, 193, 202, 207, 208, 209, 213, 219, 224, 254, 264, C.I. I. Pigment Violet 1 (Rhodamine Lake), 3, 5: 1, 16, 19, 23, 38, C.I. I. Pigment Blue 1, 2, 15 (phthalocyanine blue), 15: 1, 15: 2, 15: 3, 15: 4 (phthalocyanine blue), 16, 17: 1, 56, 60, 63, C.I. I. Pigment Greens 1, 4, 7, 8, 10, 17, 18, 36 and the like.

The dye is not particularly limited, and acid dyes, direct dyes, reactive dyes, and basic dyes can be used, and one type may be used alone or two or more types may be used in combination.
As the dye, for example, C.I. I. Acid Yellow 17, 23, 42, 44, 79, 142, C.I. I. Acid Red 52,80,82,249,254,289, C.I. I. Acid Blue 9,45,249, C.I. I. Acid Black 1,2,24,94, C.I. I. Food Black 1, 2, C.I. I. Direct Yellow 1,12,24,33,50,55,58,86,132,142,144,173, C.I. I. Direct Red 1,4,9,80,81,225,227, C.I. I. Direct Blue 1,2,15,71,86,87,98,165,199,202, C.I. I. Dilekdo Black 19, 38, 51, 71, 154, 168, 171, 195, C.I. I. Reactive Red 14, 32, 55, 79, 249, C.I. I. Reactive Black 3, 4, 35 and the like can be mentioned.

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

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

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

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

-Surfactant-
The clear ink preferably contains a surfactant.
By adding a surfactant to the ink, the surface tension is reduced and the ink droplets permeate into the recording medium after landing on the recording medium such as paper, so that feathering and color bleeding can be reduced. Can be done.

Surfactants are classified into nonionic, anionic and amphoteric according to the polarity of the hydrophilic group. Further, it is classified into fluorine type, silicone type, acetylene type and the like according to the structure of the hydrophobic group.
In the present invention, it is preferable to use a fluorine-based surfactant, but a silicone-based surfactant and an acetylene-based surfactant may be used in combination.

The content of the surfactant in the ink is preferably 2% by mass or less, more preferably 0.05% by mass or more and 2% by mass or less, and further preferably 0.1% by mass or more and 2% by mass or less. By setting the content of the surfactant to 2% by mass or less, a large decrease in glossiness can be obtained in the low gloss printing mode.

As the surfactant, any of a silicone-based surfactant, a fluorine-based surfactant, an amphoteric surfactant, a nonionic surfactant, and an anionic surfactant can be used.
The silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. Among them, those that do not decompose even at high pH are preferable, and examples thereof include side chain modified polydimethylsiloxane, double-ended modified polydimethylsiloxane, one-ended modified polydimethylsiloxane, and side chain double-ended modified polydimethylsiloxane. Those having an oxyethylene group and a polyoxyethylene polyoxypropylene group are particularly preferable because they exhibit good properties as an aqueous surfactant. Further, as the silicone-based surfactant, a polyether-modified silicone-based surfactant can also be used, and examples thereof include a compound in which a polyalkylene oxide structure is introduced into the Si portion side chain of dimethylsiloxane.
As the fluorine-based surfactant, for example, a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic acid compound, a perfluoroalkyl phosphate ester compound, a perfluoroalkyl ethylene oxide adduct, and a perfluoroalkyl ether group are contained in a side chain. A polyoxyalkylene ether polymer compound is particularly preferable because it has a low foaming property. Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid and perfluoroalkyl sulfonic acid salt. Examples of the perfluoroalkylcarboxylic acid compound include perfluoroalkylcarboxylic acid and perfluoroalkylcarboxylic acid salt. The polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain includes a sulfate ester salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain and a perfluoroalkyl ether group in the side chain. Examples thereof include salts of polyoxyalkylene ether polymers. The counterions of the salts in these fluorine-based surfactants are Li, Na, K, NH ₄ , NH ₃ CH ₂ CH ₂ OH, NH ₂ (CH ₂ CH ₂ OH) ₂ , NH (CH ₂ CH ₂ OH). _{3 and the} like can be mentioned.
Examples of the amphoteric surfactant include laurylaminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, and lauryl dihydroxyethyl betaine.
Examples of the nonionic surfactant include polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkyl amine, polyoxyethylene alkyl amide, polyoxyethylene propylene block polymer, sorbitan fatty acid ester, and polyoxyethylene sorbitan. Examples thereof include ethylene oxide adducts of fatty acid esters and acetylene alcohols.
Examples of the anionic surfactant include salts of polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, lauryl salt, and polyoxyethylene alkyl ether sulfate.
These may be used alone or in combination of two or more.

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

[General formula (S-1)]
(However, 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.)

Commercially available products can be used as the above-mentioned polyether-modified silicone-based surfactant, for example, KF-618, KF-642, KF-643 (manufactured by Shin-Etsu Chemical Co., Ltd.), EMALEX-SS-5602, SS. -1906EX (manufactured by Nippon Emulsion Co., Ltd.), FZ-2105, FZ-2118, FZ-2154, FZ-2161, FZ-2162, FZ-2163, FZ-2164 (manufactured by Toray Dow Corning Silicone Co., Ltd.), BYK -33, BYK-387 (manufactured by Big Chemie Co., Ltd.), TSF4440, TSF4452, TSF4453 (manufactured by Toshiba Silicon Co., Ltd.) and the like.

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

[General formula (F-1)]
In the compound represented by the general formula (F-1), m is preferably an integer of 0 to 10, and n is preferably an integer of 0 to 40 in order to impart water solubility.

[General formula (F-2)]
C _n F _{2n + 1} −CH ₂ CH (OH) CH ₂ −O− (CH ₂ CH ₂ O) _a− Y
In the compound represented by the above general formula (F-2), Y is H or C _m F _{2 m + 1} and m is an integer of 1 to 6, or CH ₂ CH (OH) CH _2- C _m F _{2 m + 1} and m is An integer of 4 to 6, or C _p H _{2p + 1,} where p is an integer of 1 to 19. n is an integer of 1-6. a is an integer of 4 to 14.

Commercially available products may be used as the above-mentioned fluorine-based surfactant. Examples of this commercially available product include Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, and S-145 (all manufactured by Asahi Glass Co., Ltd.); Full Lard FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M Ltd.); Megafuck F-470, F -1405, F-474 (all manufactured by DIC Corporation); Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR (all manufactured by DuPont) ); FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW (all manufactured by Neos Co., Ltd.), Polyfox PF-136A, PF-156A, PF-151N, PF 154, PF-159 (manufactured by Omniova), Unidyne DSN-403N (manufactured by Daikin Industries, Ltd.) and the like can be mentioned. Among these, FS-300 manufactured by DuPont, FT-110 and FT-made by Neos Co., Ltd., from the viewpoint of remarkably improving good print quality, particularly color development, penetrability to paper, wettability, and leveling property. 250, FT-251, FT-400S, FT-150, FT-400SW, Polyfox PF-151N manufactured by Omninova, and Unidyne DSN-403N manufactured by Daikin Industries, Ltd. are particularly preferable.

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

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

-Rust inhibitor-
The rust preventive is not particularly limited, and examples thereof include acidic sulfites and sodium thiosulfate.

-PH regulator-
The pH adjusting agent is not particularly limited as long as the pH can be adjusted to 7 or more, and examples thereof include amines such as diethanolamine and triethanolamine.

-Physical properties-
The physical properties of the ink are not particularly limited and may be appropriately selected depending on the intended purpose. For example, the viscosity, static surface tension, pH and the like are preferably in the following ranges.
The viscosity of the ink at 25 ° C. is preferably 5 mPa · s or more and 30 mPa · s or less, preferably 5 mPa · s or more and 25 mPa · s or less, from the viewpoint of improving the print density and character quality and obtaining good ejection properties. More preferred. Here, for the viscosity, for example, a rotary viscometer (manufactured by Toki Sangyo Co., Ltd., RE-80L) can be used. As the measurement conditions, it is possible to measure at 25 ° C. with a standard cone rotor (1 ° 34'x R24), a sample liquid volume of 1.2 mL, a rotation speed of 50 rpm, and 3 minutes.
The static surface tension of the ink is preferably 35 mN / m or less, more preferably 32 mN / m or less at 25 ° C. from the viewpoint that the ink is preferably leveled on the recording medium and the drying time of the ink is shortened.
The static surface tension of the clear ink as S _CL, if the static surface tension of the color ink and S _C, the difference between the S _C and the S _CL is the absolute value, at most 3 mN / m However, it is preferable from the viewpoint of suppressing the occurrence of bleeding. The difference between the _{S C} and the _{S CL} is the absolute value, and more preferably not more than 1 mN / m.
The pH of the ink is preferably 7 to 12, and more preferably 8 to 11 from the viewpoint of preventing corrosion of the metal member in contact with the liquid.

<Printed matter>
The printed matter is not limited to that used as a recording medium, and for example, wallpaper, flooring materials, building materials such as tiles, clothing cloth such as T-shirts, textiles, leather and the like can be appropriately used. By adjusting the configuration of the path for transporting the recording medium, ceramics, glass, metal, or the like can be used as the printed matter.

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

In the present invention, it is preferable to use a printed matter having a high glossiness in the low gloss printing mode. A printed matter having a high glossiness is preferable because the low gloss effect of the clear ink is easily emphasized.
On the other hand, in the high-gloss printing mode, it is preferable to use a printed matter having a low glossiness. A printed matter having a low glossiness is preferable because the high gloss effect of the clear ink is easily emphasized.

Therefore, the glossiness of the substrate used in the low gloss printing mode and _{G matte,} the gloss of the substrate and _{G gloss} used in high gloss printing _mode, is preferably _{G matte> G gloss, G matte} -G It is more preferable that _gloss ≧ 100.

In addition, G _matte > G _gloss is obtained by measuring, for example, a 60 ° gloss value. The 60 ° gloss value is measured using, for example, a glossiness measuring device (Microtrigloss, manufactured by BYK).

(Gloss control method for printed images)
The glossiness control method for a printed image of the present invention includes a printing step of ejecting ink onto a printed matter using an ink ejection head to provide a printing layer, and a heating step of heating the printed printed matter. The glossiness control method of the above, wherein the ink is an ink set having a clear ink containing a resin and water and a color ink containing a resin, a coloring material, and water, and the resin of the clear ink and the above. The resin of the color ink is a resin containing a common component, and the glossiness control method of the printed image is a low gloss printing mode which is a printing mode for imparting low gloss and a high gloss printing mode for imparting high gloss. It has a print mode, and when printing in the low gloss printing mode, it controls to raise the heating temperature, and when printing in the high gloss printing mode, it controls to lower the heating temperature.

<Printed matter>
The printed matter obtained by the present invention is a printed matter having a printed matter and a printed matter on the printed matter, and the printed matter comprises a clear ink layer containing a resin and a color ink layer containing a resin. According to the present invention, a printed matter whose gloss is controlled in both matte and glossy conditions can be obtained.

<Recording device, recording method>
In the following description of the recording device and the recording method, a case where black (K) ink, cyan (C) ink, magenta (M) ink, and yellow (Y) ink are used will be described, but instead of these, or In addition to these, water-based clear ink may be used.
The clear ink used in the present invention can be suitably used for various recording devices by an inkjet recording method, for example, a printer, a facsimile device, a copying device, a printer / fax / copier multifunction device, a three-dimensional modeling device, and the like.
Unless otherwise specified, the inkjet printing apparatus includes both a serial type apparatus that moves the ejection head and a line type apparatus that does not move the ejection head.
Further, the inkjet printing device includes not only a desktop type but also a wide recording device and a continuous book printer capable of using, for example, continuous paper wound in a roll shape as a recording medium.
In the present invention, the recording device and the recording method are devices capable of ejecting ink and various processing liquids to a recording medium, and a method of recording using the device. The recording medium means a medium on which ink and various treatment liquids can adhere even temporarily.
This recording device can include not only a head portion for ejecting ink, but also means related to feeding, transporting, and discharging paper of a recording medium, and other devices called pretreatment devices and posttreatment devices. ..
Further, the recording device and the recording method are not limited to those in which significant images such as characters and figures are visualized by ink. For example, those that form patterns such as geometric patterns and those that form a three-dimensional image are also included.
Further, the recording device includes both a serial type device that moves the discharge head and a line type device that does not move the discharge head, unless otherwise specified.
Further, for this recording device, it is possible to use not only a desktop type but also a wide recording device capable of printing on an A0 size recording medium, for example, continuous paper wound in a roll shape as a recording medium. A continuous line printer is also included.

An example of the recording device will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective explanatory view of the recording device. FIG. 2 is a perspective explanatory view of the main tank. The image forming apparatus 400 as an example of the recording apparatus is a serial type image forming apparatus. A mechanical unit 420 is provided in the exterior 401 of the image forming apparatus 400. Each ink container 411 of the main tank 410 (410k, 410c, 410m, 410y) for each color of black (K), cyan (C), magenta (M), and yellow (Y) is, for example, an aluminum laminate film or the like. It is made of packaging members. The ink container 411 is housed in, for example, a plastic container case 414. As a result, the main tank 410 is used as an ink cartridge for each color.
On the other hand, a cartridge holder 404 is provided behind the opening when the cover 401c of the apparatus main body is opened. The main tank 410 is detachably attached to the cartridge holder 404. As a result, each ink ejection port 413 of the main tank 410 and the ejection head 434 for each color communicate with each other via the supply tube 436 for each color, and ink can be ejected from the ejection head 434 to the recording medium.

This recording device can include not only a portion that ejects ink, but also a device called a pretreatment device, a posttreatment device, and the like.
As one aspect of the pretreatment device and the posttreatment device, as in the case of inks such as black (K), cyan (C), magenta (M), and yellow (Y), a liquid having a pretreatment liquid and a posttreatment liquid. There is an embodiment in which a storage unit and a liquid discharge head are added, and the pretreatment liquid and the posttreatment liquid are discharged by an inkjet recording method.
As another aspect of the pretreatment device and the posttreatment device, there is a mode in which a pretreatment device and a posttreatment device by, for example, a blade coating method, a roll coating method, and a spray coating method are provided other than the inkjet recording method.

Here, FIG. 3 shows the inside of the main body of the inkjet printing apparatus, and the recording head 2, the platen 3, the roll media storage unit 4, the heating means, and the like are arranged.
The carriage 15 is a recording head 2 which is a discharge means for ejecting ink droplets by mounting clear ink and, if necessary, black (K), yellow (Y), magenta (M), and cyan (C) inks. Is installed.
Further, the roll media accommodating unit 4 is a paper feeding means, and a roll media (recording media) 30 which is a printed matter is set.
The transporting means 60 is composed of a feed roller 34 and a presser roller 35 provided so as to face each other below and above the platen 3 with the platen 3 interposed therebetween.
Then, the printed matter (recording medium) 29 is sandwiched between the feed roller 34 and the presser roller 35, and the feed roller 34 is rotated forward (in the direction of the arrow in FIG. 3) to carry it onto the platen 3. The structure is such that the recorded media 29 can be conveyed forward on the platen 3.

Further, the preheater 40 (heating before printing) for preliminarily heating the recording media 29 upstream in the recording media transport direction of the platen 3 and heating for adhering the clear ink to the printed matter from the nozzle of the recording head are performed. (Heating during printing) A print heater 41 is provided as a heating means.
Further, on the downstream side of the recording head 2, a post heater 42 may be provided on the downstream side of the platen 3 (heating after printing). By providing the post heater 42, the recording medium 29 can be continuously heated to promote the drying of the landed ink droplets, which is preferable.
For the preheater 40, the print heater 41, and the post heater 42, for example, a conductive heating heater using ceramic or nichrome wire is used. Other heating means such as hot air heating may be used.

Further, further heating means may be provided on the downstream side after the start point of the post heater 42, such as a warm air fan 43 that blows warm air onto the recording surface on which the ink of the recording media 29 has landed.
The recording media 29 can be wound up by the take-up roll 39 after being completely dried by directly applying warm air to the ink on the recording surface by the warm air fan.

The method of using the ink is not limited to the inkjet recording method, and can be widely used. In addition to the inkjet recording method, examples thereof include a blade coating method, a gravure coating method, a bar coating method, a roll coating method, a dip coating method, a curtain coating method, a slide coating method, a die coating method, and a spray coating method.

The use of the ink is not particularly limited and can be appropriately selected depending on the purpose, and can be applied to, for example, printed matter, paint, coating material, base material and the like. Further, it can be used not only as an ink to form two-dimensional characters and images, but also as a material for three-dimensional modeling for forming a three-dimensional three-dimensional image (three-dimensional model).
As the three-dimensional modeling apparatus for modeling the three-dimensional object, a known one can be used, and the device is not particularly limited, but for example, one provided with ink accommodating means, supply means, ejection means, drying means and the like is used. be able to. The three-dimensional model includes a three-dimensional model obtained by overcoating with ink. In addition, a molded product obtained by processing a structure in which ink is applied on a base material such as a recording medium is also included. The molded product is, for example, a sheet-like or film-shaped recorded material or structure that has been subjected to molding processing such as heat stretching or punching, and is, for example, an automobile, an OA device, or electricity. -Suitably used for molding after decorating the surface of electronic devices, meters for cameras, panels of operation parts, etc.

In addition, image formation, recording, printing, printing, etc. in the terms of the present invention are all synonymous.
Recording media, media, and printed matter are all synonymous.

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

(Preparation Example 1)
<Preparation of polyurethane resin emulsion 1>
Polycarbonate diol (reaction product of 1,6-hexanediol and dimethyl carbonate (number average molecular weight (Mn): 1,200)) 1,500 mass in a reaction vessel containing a stirrer, a reflux cooling tube, and a thermometer. 220 parts by mass of 2,2-dimethylolpropionic acid (hereinafter, also referred to as "DMPA"), and 1,347 parts by mass of N-methylpyrrolidone (hereinafter, also referred to as "NMP") are nitrogen. It was charged under an air stream and heated to 60 ° C. to dissolve DMPA.
Next, 1,445 parts by mass of 4,4'-dicyclohexylmethane diisocyanate and 2.6 parts by mass of dibutyltin dilaurylate (catalyst) were added and heated to 90 ° C., and a urethanization reaction was carried out over 5 hours. Urethane prepolymer was obtained. The reaction mixture was cooled to 80 ° C., 149 parts by mass of triethylamine was added thereto, 4,340 parts by mass was extracted from the mixture, and under strong stirring, 5,400 parts by mass of water and 15 parts by mass of triethylamine were extracted. Was added to the mixed solution of.
Next, 1,500 parts by mass of ice was added, and 626 parts by mass of a 35% by mass 2-methyl-1,5-pentanediamine aqueous solution was added to carry out a chain extension reaction so that the solid content concentration became 30% by mass. The solvent was distilled off from the mixture to obtain a polycarbonate-based polyurethane resin emulsion 1 (solid content concentration: 30% by mass).
When the obtained polycarbonate-based polyurethane resin emulsion 1 was measured with a film-forming temperature tester (manufactured by Imoto Seisakusho Co., Ltd.), the minimum film-forming temperature was 55 ° C.

(Preparation Example 2)
<Preparation of polyurethane resin emulsion 2>
In a reaction vessel containing a stirrer, a reflux cooling tube, and a thermometer, 100 parts by mass of methyl ethyl ketone (MEK), polyester polyol (1) (iPA / AA = 6/4 (molar ratio)) and EG / NPG = 1 / Polyester polyol obtained from 9 (molar ratio), number average molecular weight = 2,200, average number of functional groups = 2, iPA: isophthalic acid, AA: adipic acid, EG: ethylene glycol, NPG: neopentyl glycol) 345 parts by mass and 2,2-dimethylol propionic acid (DMPA) were charged in an amount of 9.92 parts by mass and mixed uniformly at 60 ° C.
Next, 45.1 parts by mass of triethylene glycol diisocyanate (TEGDI) and 0.08 parts by mass of dioctyltin dilaurate (DOTDL) were further charged in the reactor and reacted at 72 ° C. for 3 hours to obtain a polyurethane solution. .. 80 parts by mass of iPA, 220 parts by mass of MEK, 3.74 parts by mass of triethylamine (TEA), and 596 parts by mass of water were added to this polyurethane solution for phase inversion, and then MEK and iPA were removed with a rotary evaporator. Then, the polyurethane resin emulsion 2 was obtained. After cooling the obtained polyurethane resin emulsion 2 to room temperature, ion-exchanged water and an aqueous sodium hydroxide solution were added to adjust the solid content to 30% by mass and pH 8. The glass transition point (Tg) of the obtained polyurethane resin emulsion 2 measured with "Thermo plus EVO2" (manufactured by Rigaku) was -3 ° C.

(Preparation Example 3)
<Preparation of acrylic resin emulsion 1>
900 parts by mass of ion-exchanged water and 1 part by mass of sodium lauryl sulfate were placed in a reaction vessel equipped with a stirrer, a reflux condenser, a dropping device, and a thermometer, and the temperature was raised to 70 ° C. while substituting nitrogen under stirring. Keep the internal temperature at 70 ° C., add 4 parts by mass of potassium persulfate as a polymerization initiator, and after dissolution, 450 parts by mass of ion-exchanged water, 3 parts by mass of sodium lauryl sulfate, 20 parts by mass of acrylamide, 365 parts by mass of styrene, The emulsion prepared by adding 545 parts by mass of butyl acrylate and 10 parts by mass of methacrylic acid under stirring was continuously added dropwise into the reaction solution over 4 hours. After completion of the dropping, the mixture was held for 3 hours.
After cooling the obtained aqueous emulsion to room temperature, ion-exchanged water and an aqueous sodium hydroxide solution were added to adjust the pH to 8, to obtain acrylic resin emulsion 1 (solid content concentration: 30% by mass).

(Manufacturing Example 1)
-Manufacturing of clear ink A-
Polyurethane resin emulsion 1 of Preparation Example 1 (solid content concentration: 30% by mass) 25% by mass, 1,2-propanediol 20% by mass, 1,3-propanediol 11% by mass, 1,2-butanediol 2% by mass , 5% by mass of trade name "FS-300" (manufactured by DuPont, fluorine-based surfactant, solid content concentration 40% by mass) and 37% by mass of high pure water were added as a surfactant, and the mixture was mixed and stirred to prepare a mixture. did.
Next, the obtained mixture was filtered through a polypropylene filter having an average pore size of 0.2 μm (trade name: Betafine polypropylene pleated filter PPG series, manufactured by 3M) to prepare clear ink A.

(Manufacturing Examples 2 to 4)
-Manufacturing of clear inks B to D-
Clear inks B to D were produced in the same manner as in Production Example 1 except that the ink composition was changed to that shown in Table 1.

<Static surface tension>
For the obtained clear inks A to D, the static surface tension (mN / m) of each ink at 25 ° C. was measured on a platinum plate using a fully automatic surface tension meter (CBVP-Z, manufactured by Kyowa Interface Science Co., Ltd.). Measured by method. The results are shown in Table 1.

(Manufacturing Example 5)
<Manufacturing of Magenta Ink A>
-Preparation of self-dispersing magenta pigment dispersion-
After premixing the following formulation mixture, it is circulated and dispersed for 7 hours in a disc type bead mill (manufactured by Simmal Enterprises Co., Ltd., KDL type, media: using 0.3 mm diameter zirconia balls) to self-disperse magenta pigment dispersion (Pigment solid content concentration: 15% by mass) was obtained.
・ Pigment Red 122 (trade name: Toner Magenta EO02, manufactured by Clariant Japan Co., Ltd.) ・ ・ ・ 15 parts by mass ・ Anionic surfactant (trade name: Pionin A-51-B, manufactured by Takemoto Oil & Fat Co., Ltd.) ・ ・ ・2 parts by mass ・ Ion-exchanged water ・ ・ ・ 83 parts by mass

-Manufacturing magenta ink-
Polyurethane resin emulsion 1 of Preparation Example 1 (solid content concentration: 30% by mass) 25% by mass, self-dispersion magenta pigment dispersion (pigment solid content concentration: 15% by mass) 20% by mass, 1,2-propanediol 20% by mass %, 1,3-Propanediol 11% by mass, 1,2-butanediol 3% by mass, trade name "FS-300" as a surfactant (manufactured by DuPont, fluorine-based surfactant, solid content concentration 40% by mass) ) 6% by mass and 15% by mass of high pure water were added, and the mixture was mixed and stirred to prepare a mixture.
Next, the obtained mixture was filtered through a polypropylene filter having an average pore size of 0.2 μm (trade name: Betafine polypropylene pleated filter PPG series, manufactured by 3M) to prepare magenta ink A.

(Manufacturing Example 6)
-Manufacturing of magenta ink B-
In Production Example 5, the polyurethane resin emulsion 1 was changed to the polyurethane resin emulsion 2 (solid content concentration: 30% by mass) 25% by mass, the FS-300 was changed to 4.5% by mass, and the high pure water was changed to 16.5% by mass. Magenta ink B was produced in the same manner as in Production Example 5.

(Manufacturing Example 7)
-Manufacturing of Magenta Ink C-
In Production Example 5, the magenta ink C was prepared in the same manner as in Production Example 5, except that the polyurethane resin emulsion 1 was changed to the acrylic resin emulsion 1 (solid content concentration: 30% by mass) 23% by mass and the high pure water was changed to 17% by mass. Made.

<Static surface tension>
For the obtained magenta inks A to C, the static surface tension (mN / m) of each ink at 25 ° C. was measured on a platinum plate using a fully automatic surface tension meter (CBVP-Z, manufactured by Kyowa Interface Science Co., Ltd.). Measured by method. The results are shown in Table 2.

(Example 1)
<Inkjet printing>
The ink cartridge of an inkjet recording device (IPSiO GXe-5500 modified machine manufactured by Ricoh Co., Ltd.) is filled with the clear ink A of Production Example 1 and the magenta ink A of Production Example 5, and the ink cartridge filled with these inks is described above. The printing was performed in an environment adjusted to a temperature of 25 ° C. ± 0.5 ° C. and 50 ± 5% RH. Further, the modified machine is provided with a heater (temperature control controller, model: MTCD, manufactured by Misumi Co., Ltd.) so that the recording medium can be heated from the back surface before, during, and after printing. As a result, printing can be performed on a recording medium heated by a heater before and during printing, and the printed matter can be heated and dried by the heater after printing.
Printing was performed by changing the type of recording medium, heating conditions, and printed image in the high-gloss printing mode and the low-gloss printing mode.

-Type of recording medium-
In the high-gloss printing mode, synthetic paper VJFN160 (white polypropylene film, glossiness 16 (60 ° gloss value)) manufactured by YUPO Co., Ltd. was used as the recording medium 1.
In the low-gloss printing mode, a window film GIY0305 (transparent polyethylene terephthalate (PET) film, glossiness 159 (60 ° gloss value)) manufactured by Lintec Sign System Co., Ltd. was used as the recording medium 2.

-Heating conditions-
As for the heating conditions, in the high-gloss printing mode, the heating temperatures (= T _gloss (° C.)) of the heaters (heating means) arranged before, during, and after printing were set to 60 ° C, 60 ° C, and 70 ° C. .. In the low-gloss printing mode, the heating temperature (= T _matte (° C.)) of each heater (heating means) was set to 65 ° C., 65 ° C., and 70 ° C. When the temperature of the recording medium during printing is measured, the temperature of the recording medium in the high-gloss printing mode is 59 ° C., and the temperature of the heating means in the high-gloss printing mode during printing is 60 ° C. Further, when the temperature of the recording medium during printing is measured, the temperature of the recording medium in the low-gloss printing mode is 64 ° C, and the temperature of the heating means in the low-gloss printing mode during printing is 65 ° C.
The temperature of the recording medium during printing was measured by a digital radiation temperature sensor FT-H10 (manufactured by KEYENCE CORPORATION).

-Printed image-
The printed image of magenta ink is not limited to the print mode, and a full image having an image resolution of 600 dpi × 600 dpi and a printing rate of 100% and 9-point characters of magenta single color are printed.
Regarding the clear ink, the image printed in the high-gloss printing mode was a total image having an image resolution of 600 dpi × 600 dpi and a printing rate of 100%.
Regarding the clear ink, the image printed in the low gloss printing mode was a halftone image having an image resolution of 600 dpi × 600 dpi and a printing rate of 40%.
The clear ink image was printed smaller than the magenta printed image. The part where the 9-point magenta characters are printed is completely covered with the clear ink image, and the part of the magenta single color all solid image is partially covered with the clear ink image, but partly Printed so that there was only magenta ink, without clear ink printed.

-Print rate-
The printing rate here means the following.
Printing rate (%) = number of clear ink printing dots / (vertical resolution x horizontal resolution) x 100
(However, in the above formula, the "number of clear ink printing dots" is the number of dots actually printed with clear ink per unit area, and the "vertical resolution" and "horizontal resolution" are the resolutions per unit area, respectively. When printing clear inks in layers so that they have the same dot position, the "clear ink printing dot number" is represented by the total number of dots actually printed with clear ink per unit area.)

In both the low-gloss print mode and the high-gloss print mode, magenta ink is printed on the recording medium as the first layer and clear ink is printed as the second layer, and the print is cleared on the magenta ink print image. Two layers were printed so that the printed image of the ink was printed, and the two layers were printed at the same time and then dried. Two layers of magenta ink + clear ink were printed in one printing. The printing conditions at this time and the heater set temperatures before, during, and after printing are shown in Tables 3-1 and 3-2.
Next, the obtained printed matter was evaluated for glossiness, scratch resistance, and bleeding as follows. The results are shown in Table 4. Incidentally, each embodiment, the absolute value difference between S _CL and S _C of the comparative example shown in Table 4.

<Glossy or matte>
The portion of the obtained printed matter covered with magenta ink was visually evaluated based on the following criteria. The glossiness was evaluated in the high gloss printing mode, and the matte feeling was evaluated in the low gloss printing mode. In addition, A and B were accepted, and C was rejected.
[Evaluation criteria]
A: The clear ink printed portion clearly feels glossy or matte than the clear ink unprinted portion.
B: The clear ink printed portion feels more glossy or matte than the clear ink unprinted portion, but it cannot be understood unless it is clearly seen.
C: The clear ink printed portion does not feel glossy or matte, or feels weaker than the clear ink unprinted portion.

<Scratch resistance (adhesiveness)>
The magenta ink of the obtained printed matter is rubbed back and forth 100 times with a cotton cloth with a load of 200 g applied from above to a portion covered with clear ink to a length of 100 mm, and the image of the printed portion is peeled off. , And the degree of dirt on the cotton cloth was visually observed to evaluate the scratch resistance (adhesiveness). The evaluation criteria at this time were as follows, A was accepted and B and C were rejected.
[Evaluation criteria]
A: No image peeling and no stains on the cotton cloth.
B: A part of the image is slightly peeled off, or a part of the cotton cloth is slightly stained.
C: There is peeling on the entire image, or dark stains are seen on the entire cotton cloth.

<Bleed evaluation between clear ink and color ink>
The bleed (bleeding) between the clear ink and the color ink was visually evaluated for the portion printed with the characters of the magenta ink according to the following criteria. A and B were accepted, and C was rejected.
[Evaluation criteria]
A: No bleeding occurs, characters can be clearly recognized, and no bleeding is observed.
B: Some bleeding occurs and the characters bleed a little.
C: Bleed occurs and it is difficult to recognize characters.

(Example 2)
In Example 1, in the high-gloss printing mode, the heating temperatures (= T _gloss ) of the heaters before, during, and after printing are set to 50 ° C., 50 ° C., and 70 ° C. to _achieve low gloss. In the printing mode, inkjet printing was performed in the same manner as in Example 1 except that the heating temperature (= T _matte ) of each heater was set to 70 ° C., 70 ° C., and 70 ° C.
The obtained printed matter was evaluated for glossiness, scratch resistance (adhesiveness), and bleeding in the same manner as in Example 1. The results are shown in Table 4.
When the temperature of the recording medium during printing is measured, the temperature of the recording medium in the high-gloss printing mode is 49 ° C, and the temperature of the heating means in the high-gloss printing mode during printing is 50 ° C. Further, when the temperature of the recording medium during printing is measured, the temperature of the recording medium in the low-gloss printing mode is 68 ° C., and the temperature of the heating means in the low-gloss printing mode during printing is 70 ° C.

(Example 3)
In Example 2, inkjet printing was performed in the same manner as in Example 2 except that the clear ink A of Production Example 1 was changed to the clear ink B of Production Example 2.
The obtained printed matter was evaluated for glossiness, scratch resistance (adhesiveness), and bleeding in the same manner as in Example 1. The results are shown in Table 4.

(Example 4)
In Example 2, inkjet printing was performed in the same manner as in Example 2 except that the clear ink A of Production Example 1 was changed to the clear ink C of Production Example 3.
The obtained printed matter was evaluated for glossiness, scratch resistance (adhesiveness), and bleeding in the same manner as in Example 1. The results are shown in Table 4.

(Example 5)
In Example 2, the same as in Example 2 except that the clear ink A of Production Example 1 was changed to the clear ink D of Production Example 4, and the magenta ink A of Production Example 5 was changed to the magenta ink C of Production Example 7. Then, inkjet printing was performed.
The obtained printed matter was evaluated for glossiness, scratch resistance (adhesiveness), and bleeding in the same manner as in Example 1. The results are shown in Table 4.

(Example 6)
In Example 2, inkjet printing was performed in the same manner as in Example 2 except that the magenta ink A of Production Example 5 was changed to the magenta ink B of Production Example 6.
The obtained printed matter was evaluated for glossiness, scratch resistance (adhesiveness), and bleeding in the same manner as in Example 1. The results are shown in Table 4.

(Comparative Example 1)
In Example 2, inkjet printing was performed in the same manner as in Example 2 except that the magenta ink A of Production Example 5 was changed to the magenta ink C of Production Example 7.
The obtained printed matter was evaluated for glossiness, scratch resistance (adhesiveness), and bleeding in the same manner as in Example 1. The results are shown in Table 4.

(Comparative Example 2)
In Example 2, inkjet printing was performed in the same manner as in Example 2 except that the clear ink A of Production Example 1 was changed to the clear ink D of Production Example 4.
The obtained printed matter was evaluated for glossiness, scratch resistance (adhesiveness), and bleeding in the same manner as in Example 1. The results are shown in Table 4.

(Comparative Example 3)
In Example 2, inkjet printing was performed in the same manner as in Example 2 except that the magenta ink A of Production Example 5 was changed to the magenta ink B of Production Example 6.
The obtained printed matter was evaluated for glossiness, scratch resistance (adhesiveness), and bleeding in the same manner as in Example 1. The results are shown in Table 4.

From the results of Tables 3 and 4, according to the comparison of Examples 1 and 2, it is possible to change the glossiness by changing the printing rate and the heating temperature even with the same ink. all right.
According to the comparison between Examples 1 to 6 and Comparative Examples 1 to 3 with respect to scratch resistance (adhesiveness), the resins of the clear ink and the color ink are urethane emulsions containing common components and acrylic emulsions. It was found that the combination was excellent and the scratch resistance (adhesiveness) of different combinations was inferior.
Regarding the static surface tension, according to the comparison between Examples 1 to 6 and Comparative Examples 1 to 3, the absolute value of the static surface tension difference of 3 mN / m or less is bleeding regardless of the combination of resins. It turned out to be excellent.

The viscosity of the ink used above increases at once with only a slight evaporation of water, and the wet spread of the ink coating film surface occurs only at the moment of landing. When the wetting and spreading of the ink coating film surface depends on the temperature of the recording medium at the time of printing in this way, the surface shape is already determined even if the ink is heated after printing, and the remaining water only evaporates. Therefore, even if the heater temperature after printing is high in the high-gloss printing mode, it is considered that the low-gloss (matte tone) is not obtained.

2 Recording head 3 Platen 4 Roll media storage 15 Carriage 29 Recording media 30 Roll media (recording media)
34 Feed roller 35 Presser roller 39 Take-up roll 40 Preheater 41 Print heater 42 Post heater 43 Warm air fan 60 Transport means 400 Image forming device 401 Exterior 401c cover 404 Cartridge holder 410, 410k, 410c, 410m, 410y Main tank 411 Ink storage Part 413 Ink outlet 414 Storage container case 420 Mechanism part 434 Discharge head 436 Supply tube L Ink storage container

Japanese Unexamined Patent Publication No. 2015-3397 Japanese Unexamined Patent Publication No. 2009-20834

Claims (10)

A liquid storage unit that stores liquid and
A liquid discharge head that discharges the liquid onto the printed matter,
A heating means for heating the printed matter and
It is a device that discharges a liquid having
The liquid is an ink set having a clear ink containing resin and water and a color ink containing resin, a coloring material, and water.
A resin containing a common component between the clear ink resin and the color ink resin.
The device for discharging the liquid has a low-gloss printing mode, which is a printing mode for imparting low gloss, and a high-gloss printing mode, which is a printing mode for imparting high gloss.
_Assuming that the temperature of the heating means when printing in the low gloss printing mode is T _matte [° C.] and the temperature of the heating means when printing in the high gloss printing mode is T _gloss [° C.], the following equation A device for discharging a liquid, which is characterized by satisfying T _matte > T _gloss . The device for discharging the liquid according to claim 1, wherein the heating means heats the printed matter so that T _matte −T _gloss ≧ 10 [° C.]. The device for discharging the liquid according to any one of claims 1 to 2, wherein the clear ink and the resin contained in the color ink are polyurethane resins. When the static surface tension of the clear ink as S _CL, the static surface tension of the color ink and S _C, the difference between the S _C and the S _CL is in absolute value, it is below 3 mN / m according The device for discharging the liquid according to any one of Items 1 to 3. The device for discharging the liquid according to any one of claims 1 to 4, wherein the content of the resin in the clear ink is 8% by mass or more. The device for discharging the liquid according to any one of claims 1 to 5, wherein the liquid contains a surfactant, and the content of the surfactant in the liquid is 2% by mass or less. An ink storage unit that stores ink and
An ink ejection head that ejects the ink onto the printed matter, and
A heating means for heating the printed matter and
Is a printing device that has
The ink is an ink set having a clear ink containing resin and water and a color ink containing resin, a coloring material, and water.
A resin containing a common component between the clear ink resin and the color ink resin.
The printing apparatus has a low-gloss printing mode, which is a printing mode for imparting low gloss, and a high-gloss printing mode, which is a printing mode for imparting high gloss.
_Assuming that the temperature of the heating means when printing in the low gloss printing mode is T _matte [° C] and the temperature of the heating means when printing in the high gloss printing mode is T _gloss [° C], the following equation A printing apparatus characterized in that T _matte > T _gloss . A printing process in which a liquid is ejected onto a printed matter using a liquid ejection head to provide a printed layer.
A heating process in which the printed matter is heated by a heating means,
It is a method of discharging a liquid containing
The liquid is an ink set having a clear ink containing a resin and water and a color ink containing a resin, a coloring material, and water, and the resin of the clear ink and the resin of the color ink are common. It is a resin containing ingredients,
The method of discharging the liquid has a low-gloss printing mode, which is a printing mode for imparting low gloss, and a high-gloss printing mode, which is a printing mode for imparting high gloss.
_Assuming that the temperature of the heating means when printing in the low gloss printing mode is T _matte [° C.] and the temperature of the heating means when printing in the high gloss printing mode is T _gloss [° C.], the following equation A method of discharging a liquid, which comprises satisfying T _matte > T _gloss . A printing process in which ink is ejected onto a printed matter using an ejection head to provide a printed layer, and
A heating process in which the printed matter is heated by a heating means,
Is a printing method that includes
The ink is an ink set having a clear ink containing resin and water and a color ink containing resin, a coloring material, and water, and the resin of the clear ink and the resin of the color ink are common. It is a resin containing ingredients,
The printing method has a low-gloss printing mode, which is a printing mode for imparting low gloss, and a high-gloss printing mode, which is a printing mode for imparting high gloss.
_Assuming that the temperature of the heating means when printing in the low gloss printing mode is T _matte [° C] and the temperature of the heating means when printing in the high gloss printing mode is T _gloss [° C], the following equation A printing method characterized by satisfying T _matte > T _gloss . A printing process in which an ink ejection head is used to eject ink onto a printed matter to provide a printed layer.
A heating process that heats the printed matter to be printed,
Is a method for controlling the glossiness of a printed image including
The ink is an ink set having a clear ink containing resin and water and a color ink containing resin, a coloring material, and water, and the resin of the clear ink and the resin of the color ink have common components. Is a resin containing
The glossiness control method of the printed image has a low gloss printing mode which is a printing mode for imparting low gloss and a high gloss printing mode which is a printing mode for imparting high gloss.
When printing in the low-gloss printing mode, the heating temperature is controlled to be high.
A method for controlling the glossiness of a printed image, which comprises controlling the heating temperature to be lowered when printing in the high gloss printing mode.