JP2020082611A - Device for ejecting liquid, printing method and glossiness control method for printed image - Google Patents

Abstract

To provide a device for discharging a liquid which can cope with glossiness control of both a mat tone and a gloss tone and can improve stable discharge.SOLUTION: An inkjet printing device includes a liquid storage part, a liquid discharge head discharging a liquid, and heating means heating a printed matter, and has a mat glossy printing mode and a glossy printing mode, in which the liquid is a clear ink containing a resin and is circulated via an inflow passage and an outflow passage, the heating means makes a temperature at which the printed matter is heated different in the mat glossy printing mode and the glossy printing mode, when a temperature of the printed matter in a landing region when the liquid is landed on the printed matter in the mat glossy printing mode is represented by T(°C) and a temperature of the printed matter in the landing region in the glossiness printing mode is represented by T, the inkjet printing device heats the printed matter so as to satisfy Expression: T>T.SELECTED DRAWING: Figure 10

Description

The present invention relates to a device for ejecting a liquid, a printing method, and a glossiness control method for a printed image.

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

Ink jet recording apparatuses having a gloss control function have been developed. For example, in Patent Document 1, a liquid ejecting apparatus including a liquid ejecting head capable of ejecting ink containing thermoplastic resin particles from a nozzle toward a landing target, and a heating unit configured to heat an ink droplet landed on the landing target. Is disclosed. The heating means of Patent Document 1 controls the degree of film formation on the surface of the ink droplet by heating at the film formation control temperature according to the minimum film formation temperature at which the film formation on the surface of the ink droplet starts. ..

However, when controlling the gloss level with an ink containing thermoplastic resin particles, it is unavoidable to increase the resin content in the ink in order to improve the leveling property of the ejected ink coating film surface. Can easily thicken in a short time. In addition, since heating of the recording medium accelerates the drying of the ink in the head nozzles, there is a problem in that ejection instability and nozzle clogging are likely to occur.

Further, in Patent Document 1, a color ink containing a coloring material is heated at a film formation control temperature according to a minimum film formation temperature at which film formation on the surface of the ink drop starts, thereby forming a film on the surface of the ink drop. The degree of gloss is controlled to adjust the gloss level.
However, a color ink containing a color material has a problem that a sufficient gloss difference is not obtained as compared with a clear ink not containing a color material, and it is not possible to support both matte and glossy gloss control.

Patent Document 2 proposes that in an inkjet recording apparatus that uses a clear ink (UV clear ink) that is cured by irradiation with ultraviolet rays, gloss control is performed in a matte or glossy manner by controlling the amount of irradiation light.
However, since the UV clear ink has a strong odor and the odor remains on the printed matter, it is not suitable for printed matter for indoor use. For this reason, the installation place of the inkjet printing apparatus also needs an environment capable of exhausting air, and the installation place is limited. Further, the UV clear ink requires an ultraviolet irradiation device, which causes a problem that the device becomes large and the cost becomes high.

It is an object of the present invention to provide an apparatus for ejecting a liquid that can be applied to both matte and glossy gloss control and can be stably ejected.

In order to solve the above-mentioned problems, the present invention ejects a liquid having a liquid containing portion that contains a liquid, a liquid ejection head that ejects the liquid onto a print target, and a heating unit that heats the print target. The apparatus has a matte gloss print mode that is a print mode that imparts matte gloss and a glossy gloss print mode that is a print mode that imparts gloss gloss, and the liquid ejection head ejects the liquid. An individual liquid chamber communicating with a nozzle, an inflow passage for allowing the liquid to flow into the individual liquid chamber, and an outflow passage for causing the liquid to flow out of the individual liquid chamber. Is a clear ink containing resin and is circulated through the inflow passage and the outflow passage, and the heating means heats the substrate in the matte gloss print mode and the gloss gloss print mode. And the temperature of the printing material in the landing area when the liquid lands on the printing material in the matte gloss printing mode is T _matte [° C.], and in the gloss gloss printing mode, the liquid is When the temperature of the printing material in the landing area when landing on the printing material is T _gloss [° C.], the printing material is heated so that T _mattte >T _gloss .

According to the present invention, it is possible to provide a device that can support both matte and glossy gloss control and that ejects a liquid that can be stably ejected.

It is an external perspective view of a liquid ejection head. FIG. 6 is a cross-sectional explanatory view of the same head in a direction orthogonal to the nozzle array direction. It is a partial cross-sectional explanatory view of a direction parallel to the nozzle arrangement direction of the head. It is a plane explanatory view of the nozzle plate of the head. It is a plane explanatory view of each member which constitutes a channel member of the head. It is a plane explanatory view of each member which constitutes the common liquid chamber member of the head. It is a block diagram showing an example of a liquid circulation system. FIG. 3 is a sectional view taken along the line A-A′ in FIG. 2. FIG. 3 is a sectional view taken along line B-B′ of FIG. 2. FIG. 3 is a plan view of a principal part of an example of a device that ejects liquid. It is a principal part side explanatory view of the same apparatus. FIG. 9 is a plan view of a principal part of another example of the liquid ejection unit.

Hereinafter, a device for ejecting a liquid, a printing method, and a glossiness control method for a printed image according to the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments described below, and other embodiments, additions, modifications, deletions, and the like can be modified within the scope of those skilled in the art, and any mode Also, 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 ejecting liquid, printing method and glossiness control method for printed image)
The present invention is a device for ejecting a liquid, which has a liquid accommodating portion for accommodating a liquid, a liquid ejection head for ejecting the liquid onto an object to be printed, and a heating means for heating the object to be printed, and a matte gloss The liquid discharge head has a matte gloss print mode that is a print mode to be applied and a gloss gloss print mode that is a print mode to give gloss gloss, and the liquid discharge head is an individual liquid chamber that communicates with a nozzle that discharges the liquid. And an inflow channel for causing the liquid to flow into the individual liquid chamber, and an outflow channel for causing the liquid to flow out of the individual liquid chamber, wherein the liquid is a clear ink containing a resin. In addition, the heating means is circulated through the inflow passage and the outflow passage, the heating means, while different temperatures to heat the substrate in the matte gloss print mode and the gloss gloss print mode, The temperature of the printing medium in the landing area when the liquid lands on the printing medium in the matte gloss printing mode is T _matte [° C.], and the landing when the liquid lands on the printing substrate in the gloss gloss printing mode When the temperature of the printed material in the region is T _gloss [° C.], the printed material is heated so that T _mattte >T _gloss .

Further, the present invention is a device for ejecting a liquid, comprising a liquid containing portion for containing a liquid, a liquid ejection head for ejecting the liquid onto an object to be printed, and a heating unit for heating the object to be printed, A matte gloss print mode that is a print mode that imparts gloss and a gloss gloss print mode that is a print mode that imparts gloss gloss, and the liquid ejection head is an individual that communicates with a nozzle that ejects the liquid. There is a liquid chamber, an inflow passage for letting the liquid flow into the individual liquid chamber, and an outflow passage for letting the liquid flow out of the individual liquid chamber, and the liquid contains a resin. The ink is clear ink and is circulated through the inflow channel and the outflow channel, and the heating temperature of the heating unit in the matte gloss print mode is HT _matte [° C.], and the heating unit in the gloss gloss print mode. When the heating temperature of is HT _gloss [° C.], HT _matte >HT _gloss is satisfied.

A printing method of the present invention is a printing method including a printing step of ejecting a liquid onto a printing object by a liquid ejection head and a heating step of heating the printing object, and is a matte printing mode for providing a matte gloss. The liquid ejection head has a gloss printing mode and a gloss gloss printing mode which is a printing mode for imparting gloss gloss, and the liquid ejection head communicates with a nozzle for ejecting the liquid, and the individual liquid chamber An inflow passage for inflowing into the liquid chamber, and an outflow passage for outflowing the liquid from the individual liquid chamber, wherein the liquid is a clear ink containing a resin, and the inflow flow is The heating step circulates through the flow path and the outflow channel, and in the heating step, the temperature at which the substrate is heated is different between the matte gloss print mode and the gloss glossy print mode, and the liquid is used in the matte gloss print mode. Is T _matte [° C.], the temperature of the substrate in the landing region when the liquid lands on the substrate, and the temperature of the substrate in the landing region when the liquid lands on the substrate in the gloss gloss print mode. _{Is set} to T _gloss [° C.], the material to be printed is heated so that T _mattte >T _gloss .

Further, the printing method of the present invention is a printing method including a printing step of ejecting a liquid onto a printing object by a liquid ejection head, and a heating step of heating the printing object, in a printing mode for imparting a matte gloss. The liquid ejection head has a matte gloss print mode and a gloss gloss print mode that is a print mode for imparting gloss gloss, and the liquid ejection head communicates with a nozzle for ejecting the liquid, and the liquid. An inflow passage for inflowing into the individual liquid chamber, and an outflow passage for outflowing the liquid from the individual liquid chamber, wherein the liquid is a clear ink containing a resin, and The temperature of the heating means in the matte gloss printing mode is HT _matte [° C.], and the temperature of the heating means in the gloss gloss printing mode is HT _gloss [° C.]. Then, HT _matte >HT _gloss is satisfied.

As described above, in the related art, the one having the function of gloss control has been proposed, but there is a problem that the ejection becomes unstable.
The present inventors diligently studied and used a clear ink containing a resin as a liquid, and circulate the liquid by a circulation mechanism to provide a matte gloss print mode that is a print mode that gives a matte gloss and a printing that gives a glossy gloss. The above-mentioned problems are solved by making the temperature of the substrate to be heated different from that of the gloss glossy print mode, which is a mode, and making the temperature of the substrate to be printed in the matte gloss print mode higher than that of the gloss glossy print mode. The present invention has been achieved based on the finding that it is possible. According to the present invention, both matte and glossy gloss control can be supported, and stable ejection is possible.

Further, in the present invention, it is particularly preferable to use an ink jet method, and according to the present invention, an ink jet printing apparatus and an ink jet printing method capable of coping with gloss control of both matte tone and gloss tone and capable of stable ejection are provided. be able to. A printing device is an example of a device that ejects liquid.
Hereinafter, an embodiment of an apparatus for ejecting a liquid according to the present invention will be described in detail.

In the apparatus for ejecting the liquid and the printing method of the present embodiment, clear ink containing resin is used, and gloss control of both gloss and matte is performed by controlling the heating temperature.
When the matte gloss is imparted, the printing temperature is higher than that in the gloss gloss imparting mode. Due to the high temperature during printing, the clear ink containing resin suppresses the wetting and spreading of dots after it has landed on the printing object, thus suppressing coalescence of adjacent dots and the height of the dot sphere (pile height). High dots are formed. These dots form surface irregularities and give a matte gloss.

On the other hand, when gloss gloss is imparted, printing is performed at a lower temperature than in the matte gloss imparting mode. Since the temperature at the time of printing is low, the clear ink containing the resin lands on the material to be printed and then spreads the dots, so that coalescence of adjacent dots is promoted and a smooth surface is formed. This gives gloss gloss.
As described above, according to the present embodiment, both matte and glossy gloss control can be supported.

The heating means of the present embodiment sets the temperature of the printed material in the landing area when the clear ink lands on the printed material in the matte gloss print mode to T _matte [° C.], and the clear ink lands on the printed material in the gloss gloss print mode. When the temperature of the printed material in the landing area at this time is T _gloss [° C.], the printed material is heated so that T _mattte >T _gloss .

Further, it is preferable that the heating is performed so that T _matte −T _gloss ≧10° C., and it is more preferable that the heating is performed so that T _matte −T _gloss ≧20° C.
By setting T _matte −T _gloss ≧10° C., in the matte gloss printing mode, the heating temperature becomes relatively higher, the wetting and spreading of dots can be further suppressed, and dots with high pile height are formed, resulting in unevenness. Large surfaces can be formed.
On the other hand, in the gloss gloss print mode, the heating temperature is relatively lower, the wetting and spreading of the dots can be promoted, and a smooth surface can be formed by uniting adjacent dots.

The T _matte (° C.) is preferably 50° C. or higher, more preferably 50° C. or higher and 80° C. or lower. Further, T _gloss (° C.) is preferably 70° C. or lower, and more preferably 60° C. or lower. With such a temperature range, a large change in gloss can be realized in each print mode using clear ink.

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

As a method for measuring the temperature of the printed material in the printing section, for example, a thermocouple is installed on the recording medium as the printed material, the temperature of the recording medium is directly measured, and the temperature of a heater for heating the recording medium is measured and recorded. Examples include a method of setting the medium temperature and a method of measuring the temperature around the recording medium in a non-contact manner with a radiation thermometer or the like to set the recording medium temperature.

Regarding the temperature at which the temperature is measured and T _matte (° C.) and T _gloss (° C.) are set, the temperature of the printed material in the landing area when the clear ink lands on the printed material is set. The “when landing” refers to a state immediately before the clear ink lands on the printing object. In addition, the temperature of the printing medium during “printing” described below similarly refers to the temperature in a state immediately before the clear ink lands on the printing medium.

In the present invention, when the glossiness of the printed material is Gm and the surface glossiness of the printed layer after printing is Gp,
In gloss gloss printing mode: Gp≧Gm
Matte gloss print mode: Gp≦Gm
Is preferred,
In gloss gloss printing mode: Gp-Gm≧20
In the case of matte gloss print mode: Gp-Gm≤-30
Is more preferred,
In gloss gloss printing mode: Gp-Gm≧49
In the case of matte gloss print mode: Gp-Gm≤-57
Is more preferable.
When the glossiness difference satisfies the above condition, the difference between the glossy gloss portion and the matte gloss portion and the surroundings can be clearly recognized.
In order to satisfy the above conditions, for example, the setting of the heating temperature may be changed, and the printing rate may be changed.

Gm and Gp are obtained by measuring, for example, a 60° gloss value. As Gp, it is preferable to measure the 60° gloss value of the obtained printed matter and take the average value.
The 60° gloss value is measured using, for example, a glossiness measuring device (Microtrigloss, manufactured by BYK).

In the present invention, when the print rate of the _matte print image printed in the matte gloss print mode is D _matte [%] and the print rate of the gloss print image printed in the glossy gloss print mode is D _gloss [%], D _gloss >D _matte is preferable, and D _gloss- D _matte >10[%] is more preferable.
Since a smoother surface is more likely to be formed when the print rate is higher, it is preferable to use an image with a high print rate in the gloss gloss print mode. On the other hand, in the matte gloss printing mode, if the printing rate is high, coalescence of adjacent dots occurs and it becomes difficult for surface irregularities to be formed. Therefore, it is preferable that the image has a low printing rate.

Here, the printing rate means the following.
Print rate (%) = number of clear ink print dots / (vertical resolution x horizontal resolution) x 100
(However, in the above formula, "the number of dots printed by clear ink" is the number of dots actually printed with clear ink per unit area, and "vertical resolution" and "horizontal resolution" are the resolutions per unit area, respectively.
When the clear inks are overlapped and printed at the same dot position, the “clear ink print dot number” is the total number of dots actually printed with the clear ink per unit area. )
The printing rate of 100% means the maximum weight of a single color ink for a pixel.

As the print mode, for example, the matte gloss print mode and the gloss gloss print mode are changed for each printing target. Depending on the print mode, the temperature setting of the heating unit and the print rate setting are changed.

Next, another embodiment of the present invention will be described. The description of the same items as those in the above embodiment will be omitted.
In the present embodiment, when the heating temperature of the heating unit in the matte gloss print mode is HT _matte [° C.] and the heating temperature of the heating unit in the gloss gloss print mode is HT _gloss [° C.], HT _matte >HT _gloss is satisfied. .. Also in this embodiment, the same effect as that of the above embodiment can be obtained.

The condition of HT _matte >HT _gloss may be satisfied at the heating temperature of the heating unit during printing, and is also preferably satisfied at the heating temperature of the heating unit before printing.
In the present embodiment, the spread of the ink on the coating film surface occurs at the moment of landing, and it is considered that the heating after printing has little influence on the surface shape. Therefore, the heating temperature of the heating unit after printing does not necessarily have to satisfy the condition of HT _matte >HT _gloss .

In addition, in the present embodiment, the heating temperature of the heating means is preferably HT _matte −HT _gloss ≧10 [° C.]. In this case, in the matte gloss printing mode, the heating temperature is relatively higher, the wetting and spreading of the dots can be further suppressed, and the dots having a high pile height can be formed to form a surface having large unevenness.
Note that, also under the condition of HT _matte- HT _gloss ≧10 [° C.], it is preferable that the heating temperature of the heating unit during printing is satisfied, and the heating temperature of the heating unit before printing is also satisfied, similarly to the above. Is more preferable.

<Liquid storage part>
The liquid storage unit is also called, for example, an ink storage unit, and stores the liquid ink.
The ink storage unit is not particularly limited as long as it is a member that can store ink, and examples thereof include an ink storage container and an ink tank.

The ink containing container contains the ink in the container, and further includes other members appropriately selected as necessary.
The container is not particularly limited, and its shape, structure, size, material and the like can be appropriately selected according to the purpose, and examples thereof include an aluminum bag and an ink bag formed of a resin film. The thing which has at least is mentioned.
Examples of the ink tank include a main tank and a sub tank.

<Liquid ejection head>
The liquid ejection head ejects the liquid onto the printing object. The liquid ejection head according to the present embodiment has an individual liquid chamber that communicates with a nozzle through which the liquid is ejected, an inflow passage for allowing the liquid to flow into the individual liquid chamber, and an outflow for letting the liquid out of the individual liquid chamber. With the road.

Further, the liquid ejection head of the present embodiment has a nozzle plate, a stimulus generating means, etc., and the nozzles through which liquid is ejected are formed on the nozzle plate. The nozzle plate preferably has a nozzle substrate and an ink repellent film on the nozzle substrate.

The individual liquid chamber is a plurality of individual channels that are arranged corresponding to the plurality of nozzle holes provided in the nozzle plate, and communicate with the nozzle holes. It may also be called a liquid chamber, a pressure chamber, a discharge chamber, a liquid chamber, or the like.

The stimulus generation unit is a unit that generates 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 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 preferable.

Examples of the stimulus generating means include a heating device, a pressurizing device, a piezoelectric element, a vibration generating device, an ultrasonic oscillator, and a light. As the stimulus generating means, specifically, a piezoelectric actuator such as a piezoelectric element, a thermal actuator that utilizes a phase change due to film boiling of ink using an electrothermal conversion element such as a heating resistor, and a metal phase change due to a temperature change Shape memory alloy actuators using, and electrostatic actuators using electrostatic force and the like.

When the stimulus is “heat”, thermal energy corresponding to a recording signal is applied to the ink in the ink ejection head by using, for example, a thermal head. There is a method of generating bubbles in the ink by the thermal energy and ejecting the ink 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 is bent by applying a voltage to the piezoelectric element bonded to a position called the pressure chamber in an ink flow path in the ink ejection head. .. As a result, the volume of the pressure chamber is contracted, and the ink is ejected as droplets from the nozzle holes of the ink ejection head.
Among these, the piezo method in which a voltage is applied to the piezo element to eject the ink is preferable.

Details of the inflow channel and the outflow channel will be described later.

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

The method of heating the recording medium as the material to be printed is not particularly limited and can be appropriately selected depending on the purpose. For example, a method of bringing a heated fluid such as warm air as a heating means into contact with a recording medium provided with ink, a method of bringing the recording medium provided with ink into contact with a heating member to heat them by heat transfer, infrared rays or far Examples thereof include a method of heating the recording medium to which the ink is applied by irradiating an energy ray such as infrared rays.

In the heating step, the timing of heating before printing, during printing, and after printing can be appropriately changed as long as the relationship of T _matte >T _gloss or HT _matte >HT _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 according to the purpose. The heating time is preferably controlled by controlling the transport speed of the recording medium as the material to be printed.

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

<Liquid>
The liquid used in the present invention is a clear ink containing a resin. The clear ink means a colorless and transparent ink that does not substantially contain a coloring material. Note that, hereinafter, the clear ink may be simply referred to as “ink”.
The clear ink may contain water, an organic solvent, or the like, and may contain additives such as a surfactant if necessary.

<< resin >>
The resin is not particularly limited and can be appropriately selected according to the purpose. Examples thereof include polyurethane resin, polyester resin, acrylic resin, vinyl acetate resin, styrene resin, butadiene resin, styrene-butadiene resin, vinyl chloride resin, acrylic styrene resin, and acrylic silicone resin.

When producing the 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 state of a resin emulsion in which water is used as a dispersion medium. As the resin particles, those synthesized appropriately may be used, or commercially available products may be used. These may be used alone or in combination of two or more kinds 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 the clear ink. This makes it easier to prevent the inside of the coating film from breaking and peeling off a part of the coating film, or changing the surface state of the coating film and changing the tint 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 appropriately selected depending on the intended purpose without any limitation, and examples thereof include a polyurethane resin obtained by reacting a polyol with a polyisocyanate.

---Polyol---
Examples of the polyol include polyether polyol, polycarbonate polyol, polyester polyol 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 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, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexane. Examples thereof include diol, glycerin, trimethylolethane, trimethylolpropane and the like. 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, tetrahydrofuran and the like. 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 excellent scratch resistance, polyoxytetramethylene glycol, 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 for producing the polyurethane resin include those obtained by reacting a carbonic acid ester and a polyol, 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; polyethylene glycol, polypropylene glycol, polyoxytetramethylene glycol and other polyether polyols; 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 polyols include those obtained by esterifying a low molecular weight polyol and a polycarboxylic acid, polyesters obtained by ring-opening polymerization reaction of a cyclic ester compound such as ε-caprolactone, and copolymerizations 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, dodecanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, and their anhydrides or ester-forming derivatives. These may be used alone or in combination of two or more.

---Polyisocyanate---
Examples of the polyisocyanate include aromatic diisocyanates such as phenylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, and naphthalene diisocyanate; hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, tetramethylxylyl isocyanate. Aliphatic or alicyclic diisocyanates such as diisocyanate and 2,2,4-trimethylhexamethylene diisocyanate may be mentioned. These may be used alone or in combination of two or more. Of these, alicyclic diisocyanates are preferable from the viewpoint of weather resistance.

Furthermore, 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 based on the total amount of the isocyanate compound.

--- Method for producing 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 and the polyisocyanate in the absence of a solvent or in the presence of an organic solvent at an equivalent ratio in which an isocyanate group becomes excessive.
Next, 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, if necessary, the organic solvent in the system is removed. Can be obtained by

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

Examples of the polyamine include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4′-dicyclohexylmethanediamine, 1,4-cyclohexane. Diamines such as diamines; polyamines such as diethylenetriamine, dipropylenetriamine, triethylenetetramine; hydrazines such as hydrazine, N,N'-dimethylhydrazine, 1,6-hexamethylenebishydrazine; succinic acid dihydrazide, adipic acid dihydrazide , Dihydrazides such as glutaric acid dihydrazide, sebacic acid dihydrazide, and isophthalic acid dihydrazide. 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, hexamethylene glycol, Glycols such as sucrose, methylene glycol, glycerin and sorbitol; bisphenol A, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfone, hydrogenated bisphenol A, phenol such as hydroquinone Kind; water and the like can be mentioned. 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-based polyurethane resin is preferable from the viewpoints of water resistance, heat resistance, abrasion resistance, weather resistance, and image scratch resistance due to the high cohesive force of the carbonate group. When the polycarbonate-based polyurethane resin is used, an ink suitable for a recorded matter used in a harsh environment such as an outdoor application can be obtained.

As the polyurethane resin, commercially available products 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), Permarin UA-200 (polyether polyurethane resin) (above, Sanyo Kasei Co., Ltd. make) etc. are 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, and more preferably 8% by mass or more and 25% by mass or less. When the content of the resin is 8% by mass or more, the matte gloss and gloss gloss can be controlled with a small amount of clear ink. On the other hand, when the content of the resin is 25 mass% or less, it is possible to further suppress deterioration of ink ejection stability.

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

<< water >>
The water is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include ion-exchanged water, ultrafiltered 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 water content 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 based on the total amount of the 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, high viscosity is prevented, and ejection stability is further improved. On the other hand, when the content is 60% by mass or less, the wettability to the non-permeable recording medium is suitable, and the image quality is further improved.

<< organic solvent >>
The clear ink may contain an organic solvent. The organic solvent is appropriately selected depending on the intended purpose without any limitation, and examples thereof include a water-soluble organic solvent. The term “water-soluble” means that 5 g or more is dissolved in 100 g of water at 25° C., for example.

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. Polyhydric alcohols; polyhydric 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, 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, γ-butyrolactone; amides such as formamide, N-methylformamide, N,N-dimethylformamide; amines such as monoethanolamine, diethanolamine, triethylamine; dimethyl Sulfur-containing compounds such as sulfoxide, sulfolane and thiodiethanol; propylene carbonate, ethylene carbonate and the like. These may be used alone or in combination of two or more.

The content of the organic solvent in the clear ink is not particularly limited and may be appropriately selected according to the purpose. However, when used in the water-based clear ink, it is 10 mass% from the viewpoint of the drying property and ejection reliability of the ink. % Or more and 60% by mass or less is preferable, and 20% by mass or more and 60% by mass or less is more preferable.

<<Additives>>
If necessary, a surfactant, an antifoaming agent, an antiseptic/antifungal agent, an anticorrosive agent, a pH adjusting agent and the like may 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 penetration of the ink droplets into the recording medium such as paper is accelerated, so feathering and color bleeding are reduced. You can

Surfactants are classified into nonionic, anionic and amphoteric depending on the polarity of the hydrophilic group. Further, depending on the structure of the hydrophobic group, it is classified into fluorine type, silicone type, acetylene type and the like.
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, still more 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 reduction in glossiness can be obtained in the matte gloss print mode.

As the surfactant, any of silicone-based surfactants, fluorine-based surfactants, amphoteric surfactants, nonionic surfactants, and anionic surfactants can be used.
The silicone surfactant is not particularly limited and can be appropriately selected according to the purpose. Among them, those that do not decompose even at high pH are preferable, and examples thereof include side chain-modified polydimethylsiloxane, both-end modified polydimethylsiloxane, one-end modified polydimethylsiloxane, and side-chain both-end modified polydimethylsiloxane. Those having an oxyethylene group or 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 be used, and examples thereof include a compound having a polyalkylene oxide structure introduced into the side chain of the Si moiety of dimethylsiloxane.
Examples of the fluorinated surfactant include a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic acid compound, a perfluoroalkyl phosphoric acid ester compound, a perfluoroalkyl ethylene oxide adduct and a perfluoroalkyl ether group in the side chain. A polyoxyalkylene ether polymer compound is particularly preferable because it has a low foaming property. Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid and perfluoroalkyl sulfonate. Examples of the perfluoroalkylcarboxylic acid compound include perfluoroalkylcarboxylic acid and perfluoroalkylcarboxylic acid salts. As the polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in its side chain, a sulfuric acid ester salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in its side chain, or a perfluoroalkyl ether group in its side chain Examples thereof include salts of polyoxyalkylene ether polymers. The counterions of the salts in these fluorine-based surfactants include Li, Na, K, NH ₄ , NH ₃ CH ₂ CH ₂ OH, NH ₂ (CH ₂ CH ₂ OH) ₂ and NH(CH ₂ CH ₂ OH). ₃ etc. are mentioned.
Examples of the amphoteric surfactant include lauryl aminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, and lauryl dihydroxyethyl betaine.
Examples of the nonionic surfactant include polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkylamine, polyoxyethylene alkylamide, polyoxyethylene propylene block polymer, sorbitan fatty acid ester, polyoxyethylene sorbitan. Examples thereof include fatty acid esters and ethylene oxide adducts of acetylene alcohol.
Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, lauryl acid salt, and salt of 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. Examples thereof include side-chain modified polydimethylsiloxane, both-end modified polydimethylsiloxane, one-end modified polydimethylsiloxane, and side-modified. Examples thereof include polydimethyl siloxane modified at both chain ends, and a polyether modified silicone surfactant having a polyoxyethylene group or a polyoxyethylene polyoxypropylene group as a modifying group exhibits good properties as an aqueous surfactant. preferable.
As such a surfactant, those synthesized appropriately may be used, or commercially available products 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 Kagaku, etc.
The polyether-modified silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the polyalkylene oxide structure represented by the general formula (S-1) may be represented by dimethylpolyethylene. Examples thereof include those introduced into the side chain of the Si portion of siloxane.

(However, in the general formula (S-1), m, n, a, and b represent an integer. R and R'represent an alkyl group or an alkylene group.)
As the above polyether-modified silicone-based surfactant, commercially available products can be used, and examples thereof include KF-618, KF-642, KF-643 (Shin-Etsu Chemical Co., Ltd.), EMALEX-SS-5602, SS-. 1906EX (Nippon Emulsion Co., Ltd.), FZ-2105, FZ-2118, FZ-2154, FZ-2161, FZ-2162, FZ-2163, FZ-2164 (Toray Dow Corning Silicone Co., Ltd.), BYK-33, BYK-387 (Big Chemie Co., Ltd.), TSF4440, TSF4452, TSF4453 (Toshiba Silicon Co., Ltd.), etc. are mentioned.

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

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

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 general formula (F-2), Y is H, or CnF _2n+1 and n is an integer of 1 to 6, or CH ₂ CH(OH)CH ₂ -CnF _2n+1 and n is 4 to 6. An integer, or CpH _2p+1 and p is an integer of 1 to 19. a is an integer of 4-14.
A commercially available product 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, S-145 (all manufactured by Asahi Glass Co., Ltd.); Fullrad FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M Limited); Megafac F-470, F -1405, F-474 (all manufactured by Dainippon Ink and Chemicals, Inc.); Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR (all , DuPont); FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW (all are Neos Co., Ltd.), Polyfox PF-136A, PF-156A, PF-151N, PF-154, PF-159 (manufactured by OMNOVA), Unidyne DSN-403N (manufactured by Daikin Industries, Ltd.) and the like can be mentioned. Among these, good printing quality, especially color developability, penetrability to paper. , From the viewpoint that the wettability and the levelness are remarkably improved, FS-300 manufactured by Du Pont, FT-110, FT-250, FT-251, FT-400S, FT-150, FT- manufactured by Neos Co., Ltd. 400 SW, Polyfox PF-151N manufactured by Omnova Co., Ltd. and Unidyne DSN-403N manufactured by Daikin Industries, Ltd. are particularly preferable.

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

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

-Rust preventive-
The rust preventive agent is not particularly limited, and examples thereof include acid sulfite and sodium thiosulfate.

-PH adjuster-
The pH adjuster is not particularly limited as long as the pH can be adjusted to 7 or higher, 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 purpose. For example, the viscosity, surface tension, pH and the like are preferably in the following ranges.
The viscosity of the ink at 25° C. is preferably 5 mPa·s or more and 30 mPa·s or less, from the viewpoint that the printing density and character quality are improved, and that good ejection properties are obtained, and 5 mPa·s or more and 25 mPa·s or less are preferable. More preferable. Here, as the viscosity, for example, a rotary viscometer (RE-80L manufactured by Toki Sangyo Co., Ltd.) can be used. The measurement conditions are 25° C., standard cone rotor (1°34′×R24), sample liquid volume 1.2 mL, rotation speed 50 rpm, and 3 minutes.
The surface tension of the ink is preferably 35 mN/m or less, and more preferably 32 mN/m or less at 25° C. from the viewpoint that the ink is preferably leveled on the recording medium and the drying time of the ink is shortened.
The pH of the ink is preferably 7 to 12, and more preferably 8 to 11 from the viewpoint of preventing the corrosion of the metal member with which the ink comes into contact.

<Printed material>
The material to be printed is not limited to that used as a recording medium, and for example, wallpaper, flooring, building materials such as tiles, clothing cloth such as T-shirts, textiles, leather and the like can be appropriately used. It should be noted that ceramics, glass, metal or the like can be used as the printing object by adjusting the configuration of the path for conveying the recording medium.
In the present embodiment, the recording medium will be described as an embodiment of the material to be printed.

The recording medium is not particularly limited, and plain paper, glossy paper, special paper, cloth, and the like can be used, but good image formation can be performed using a non-permeable substrate.
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. , Bristow method refers to a substrate having a water absorption amount of 10 mL/m ² or less from the start of contact to 30 msec ^1/2 .
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, a polycarbonate film can be preferably used.

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

Therefore, the glossiness of the substrate used in the matt gloss print mode and _{G matte,} the gloss of the substrate and _{G gloss} used in gloss gloss print _mode, is preferably _{G matte> G gloss, G matte} -G More preferably, _gloss ≧100.

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

<How to control glossiness of printed image>
The method for controlling the glossiness of a printed image of the present invention is a method for controlling the glossiness of a printed image, which includes a printing step of ejecting a liquid onto a printing object by a liquid ejection head, and a heating step of heating the printing object. A matte gloss print mode that is a print mode that gives a matte gloss and a glossy gloss print mode that is a print mode that gives a glossy gloss are provided, and the liquid ejection head communicates with a nozzle through which the liquid is ejected. An individual liquid chamber, an inflow passage for allowing the liquid to flow into the individual liquid chamber, and an outflow passage for causing the liquid to flow out of the individual liquid chamber, wherein the liquid contains a resin. The clear ink is circulated through the inflow passage and the outflow passage, and in the heating step, the temperature for heating the substrate is different between the matte gloss print mode and the gloss gloss print mode. At the same time, the temperature of the printing medium in the landing area when the liquid lands on the printing medium in the matte gloss printing mode is set to T _matte [° C.], and the liquid lands on the printing medium in the gloss gloss printing mode. When the temperature of the printed material in the landing area at time is T _gloss [° C.],
It is characterized in that the substrate is heated so that T _matte >T _gloss.

<Printed matter>
The printed material obtained by the present invention is a printed material having a printing material and a printing layer on the printing material, and the printing layer includes a clear ink layer containing a resin. According to the present invention, it is possible to obtain a printed matter in which gloss is controlled in both a matte tone and a gloss tone.

<One Embodiment of Image Forming Apparatus>
As a result of diligent study by the present inventors, stable ejection can be obtained even under a dry load condition by ejecting the clear ink containing the above-mentioned resin using an apparatus for ejecting a liquid having a circulation mechanism. It has been found that it is possible to support gloss control of both matte and gloss tones.
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

An example of the liquid ejection head used in the present invention will be described with reference to FIGS. FIG. 1 is an external perspective view of the liquid ejection head, FIG. 2 is a cross-sectional view of the same head in a direction orthogonal to a nozzle arrangement direction, and FIG. 3 is a cross-sectional view of a direction parallel to the nozzle arrangement direction of the head. 4 is an explanatory plan view of a nozzle plate of the same head, FIG. 5 is an explanatory plan view of each member forming a flow path member of the same head, and FIG. 6 is an explanatory plan view of each member forming a common liquid chamber member of the same head. Is.

In this liquid ejection head, a nozzle plate 1, a flow path plate 2 and a vibrating plate member 3 as a wall member are laminated and joined. The piezoelectric actuator 11 that displaces the vibration plate member 3, the common liquid chamber member 20, and the cover 29 are provided.

The nozzle plate 1 has a plurality of nozzles 4 that eject liquid.
The flow path plate 2 forms an individual liquid chamber 6 that communicates with the nozzle 4, a fluid resistance portion 7 that communicates with the individual liquid chamber 6, and a liquid introduction portion 8 that communicates with the fluid resistance portion 7. The flow path plate 2 is formed by laminating and bonding a plurality of plate-shaped members 41 to 45 from the nozzle plate 1 side, and the plate-shaped members 41 to 45 and the vibration plate member 3 are laminated and bonded to form a flow path. The member 40 is configured.
The diaphragm member 3 has a filter portion 9 as an opening through which the liquid introduction portion 8 and the common liquid chamber 10 formed by the common liquid chamber member 20 pass.

The diaphragm member 3 is a wall member that forms a wall surface of the individual liquid chamber 6 of the flow path plate 2. The vibrating plate member 3 has a two-layer structure (not limited) and includes a first layer forming a thin portion and a second layer forming a thick portion from the flow path plate 2 side. A deformable vibration region 30 is formed in a portion corresponding to the chamber 6.

Here, as shown in FIG. 4, a plurality of nozzles 4 are arranged in a staggered manner on the nozzle plate 1.

As shown in FIG. 5A, the plate-shaped member 41 forming the flow path plate 2 has a through groove portion (meaning a groove-shaped through hole) 6 a forming the individual liquid chamber 6, a fluid resistance portion 51, Penetration groove parts 51a and 52a which constitute circulation channel 52 are formed.

Similarly, as shown in FIG. 5B, the plate-shaped member 42 is formed with a through groove portion 6b forming the individual liquid chamber 6 and a through groove portion 52b forming the circulation flow path 52.

Similarly, as shown in FIG. 5C, the plate-like member 43 is formed with a through groove portion 6c that forms the individual liquid chamber 6 and a through groove portion 53a that forms the circulation flow channel 53 and that has the nozzle array direction as the longitudinal direction. Has been done.

Similarly, in the plate member 44, as shown in FIG. 5D, a through groove portion 6d forming the individual liquid chamber 6, a through groove portion 7a serving as the fluid resistance portion 7, and a through groove portion 8a forming the liquid introducing portion 8 are formed. And a through groove portion 53b having a longitudinal direction in the nozzle arrangement direction that constitutes the circulation flow path 53 is formed.

Similarly, in the plate-shaped member 45, as shown in FIG. 5(e), a through groove portion 6e that forms the individual liquid chamber 6 and a through groove portion 8b that forms the liquid introduction portion 8 and has a nozzle array direction as a longitudinal direction (filter). A downstream side liquid chamber) and a through groove portion 53c having a longitudinal direction in the nozzle arrangement direction which constitutes the circulation flow path 53.

As shown in FIG. 5( f ), the vibrating plate member 3 is provided with a vibrating region 30, a filter portion 9, and a through groove portion 53 d having the nozzle array direction forming the circulation flow channel 53 as the longitudinal direction. ..

As described above, by constructing the flow path member by laminating and joining a plurality of plate-like members, it is possible to form a complicated flow path with a simple configuration.

With the above configuration, in the flow path member 40 including the flow path plate 2 and the vibration plate member 3, the fluid resistance portion 51, the circulation flow path 52, and the circulation along the surface direction of the flow path plate 2 that communicates with each individual liquid chamber 6. A circulation channel 53 in the thickness direction of the channel member 40 that communicates with the channel 52 is formed. The circulation flow path 53 communicates with a circulation common liquid chamber 50 described later.

On the other hand, in the common liquid chamber member 20, the common liquid chamber 10 and the circulation common liquid chamber 50 to which the liquid is supplied from the supply/circulation mechanism 494 are formed.

As shown in FIG. 6A, the first common liquid chamber member 21 that constitutes the common liquid chamber member 20 has a piezoelectric actuator through hole 25a, a through groove portion 10a that serves as the downstream common liquid chamber 10A, and a circulation hole. A groove portion 50a having a bottom that serves as the common liquid chamber 50 is formed.

Similarly, in the second common liquid chamber member 22, as shown in FIG. 6B, a through hole 25b for a piezoelectric actuator and a groove portion 10b which becomes the upstream common liquid chamber 10B are formed.

Referring also to FIG. 1, the second common liquid chamber member 22 is formed with a through hole 71 a serving as a supply port portion through one end of the common liquid chamber 10 in the nozzle arrangement direction and the supply port 71.
Similarly, in the first common liquid chamber member 21 and the second common liquid chamber member 22, the other end (the end opposite to the through hole 71a) of the circulation common liquid chamber 50 and the circulation port 81 are provided. Through holes 81a and 81b that communicate with each other are formed.
In addition, in FIG. 6, the groove portion having the bottom is shown by being surface-painted (the same applies to the following figures).

As described above, the common liquid chamber member 20 is configured by the first common liquid chamber member 21 and the second common liquid chamber member 22, and the first common liquid chamber member 21 is joined to the vibration plate member 3 side of the flow path member 40. Then, the second common liquid chamber member 22 is laminated and joined to the first common liquid chamber member 21.

Here, the first common liquid chamber member 21 forms a downstream common liquid chamber 10A that is a part of the common liquid chamber 10 that communicates with the liquid introduction portion 8 and a circulating common liquid chamber 50 that communicates with the circulation flow path 53. ing. Further, the second common liquid chamber member 22 forms an upstream common liquid chamber 10B which is the remaining part of the common liquid chamber 10.

At this time, the downstream common liquid chamber 10A, which is a part of the common liquid chamber 10, and the circulating common liquid chamber 50 are arranged side by side in the direction orthogonal to the nozzle arrangement direction, and the circulating common liquid chamber 50 is the common liquid chamber 10. It is located in the position where it is projected.

As a result, the size of the circulation common liquid chamber 50 is not restricted by the size required for the flow passage including the individual liquid chamber 6, the fluid resistance portion 7, and the liquid introduction portion 8 formed by the flow passage member 40.
Then, the circulation common liquid chamber 50 and a part of the common liquid chamber 10 are arranged side by side, and the circulation common liquid chamber 50 is arranged at a position where it is projected into the common liquid chamber 10, so that it is orthogonal to the nozzle arrangement direction. The width of the head in the direction can be suppressed, and the size of the head can be suppressed. The common liquid chamber member 20 forms a circulating common liquid chamber 50 together with the common liquid chamber 10 to which the liquid is supplied from the head tank or the liquid cartridge.

On the other hand, a piezoelectric actuator 11 including an electromechanical conversion element as a driving unit that deforms the vibration region 30 of the vibration plate member 3 is arranged on the opposite side of the vibration plate member 3 from the individual liquid chamber 6.
As shown in FIG. 3, this piezoelectric actuator 11 has a piezoelectric member 12 bonded on a base member 13, and the piezoelectric member 12 is grooved by half-cut dicing and the required number of piezoelectric members 12 is obtained for each piezoelectric member 12. The columnar piezoelectric elements 12A and 12B are formed in a comb shape at a predetermined interval.

Here, the piezoelectric element 12A of the piezoelectric member 12 is a piezoelectric element that is driven by giving a drive waveform, and the piezoelectric element 12B is used as a mere column without giving a drive waveform, but all the piezoelectric elements 12A and 12B are driven. It can also be used as a piezoelectric element.
Then, the piezoelectric element 12A is joined to the convex portion 30a which is the island-shaped thick portion formed in the vibration region 30 of the diaphragm member 3. Further, the piezoelectric element 12B is joined to the convex portion 30b which is the thick portion of the diaphragm member 3.

The piezoelectric member 12 is formed by alternately stacking piezoelectric layers and internal electrodes. The internal electrodes are drawn to the end faces to provide external electrodes, and the flexible wiring members 15 are connected to the external electrodes.

In the liquid ejection head configured as described above, for example, by lowering the voltage applied to the piezoelectric element 12A from the reference potential, the piezoelectric element 12A contracts, the vibration region 30 of the diaphragm member 3 descends, and the volume of the individual liquid chamber 6 decreases. The liquid flows into the individual liquid chamber 6 due to the expansion of the liquid.

After that, the voltage applied to the piezoelectric element 12A is increased to expand the piezoelectric element 12A in the stacking direction, and the vibration region 30 of the vibration plate member 3 is deformed in the direction toward the nozzle 4 to contract the volume of the individual liquid chamber 6. As a result, the liquid in the individual liquid chamber 6 is pressurized, and the liquid is ejected from the nozzle 4.

Then, the liquid is drawn from the common liquid chamber 10 by the surface tension and filled with the liquid. Finally, the negative pressure defined by the supply tank, the circulation tank, the head difference, and the surface tension of the meniscus are balanced, so that the meniscus surface is stabilized, and the next discharge operation can be performed.

The method of driving the head is not limited to the above example (pull-push ejection), and pull ejection or push ejection may be performed depending on the method of giving the drive waveform. Further, in the above-mentioned embodiment, the laminated piezoelectric element is used as the pressure generating means for giving the pressure fluctuation to the individual liquid chamber 6, but the invention is not limited to this, and a thin film piezoelectric element can be used. . Further, it is possible to use a heating resistor arranged in the individual liquid chamber 6 to generate bubbles by the heat generation of the heating resistor to change the pressure, or to generate pressure fluctuation using an electrostatic force. ..

Next, an example of the liquid circulation system using the liquid ejection head will be described with reference to FIG.
FIG. 7 is a block diagram showing the liquid circulation system in the present embodiment. As shown in FIG. 7, the liquid circulation system in this embodiment includes a main tank, a liquid discharge head, a supply tank, a circulation tank, a compressor, a vacuum pump, a liquid feed pump, a regulator (R), a supply side pressure sensor, and a circulation side. It is composed of a pressure sensor and the like, and further comprises a circulation speed control unit for adjusting the overall ink circulation speed.

The supply side pressure sensor is connected between the supply tank and the liquid ejection head, and is connected to the supply flow path side connected to the supply port 71 (see FIG. 1) of the liquid ejection head. The circulation side pressure sensor is connected between the liquid ejection head and the circulation tank, and is connected to the circulation passage side connected to the circulation port 81 (see FIG. 1) of the liquid ejection head.
Although the present embodiment is configured to have the supply-side pressure sensor and the circulation-side pressure sensor, the present invention is not limited to this, and it is preferable to have at least one of them.

One of the circulation tanks is connected to the supply tank via the first liquid feed pump, and the other of the circulation tanks is connected to the main tank via the second liquid feed pump. As a result, the liquid flows from the supply tank into the liquid ejection head through the supply port 71, is discharged from the circulation port 81 and is discharged to the circulation tank, and is further discharged from the circulation tank to the supply tank by the first liquid feed pump. The liquid is circulated by being sent.

Also, a compressor is connected to the supply tank, and the supply side pressure sensor is controlled so that a predetermined positive pressure is detected. On the other hand, a vacuum pump is connected to the circulation tank, and the circulation side pressure sensor is controlled so as to detect a predetermined negative pressure. As a result, the negative pressure of the meniscus can be kept constant while circulating the liquid through the liquid ejection head.

Also, when droplets are ejected from the nozzle of the liquid ejection head, the amount of liquid in the supply tank and the circulation tank decreases, so the liquid is transferred from the main tank to the circulation tank by appropriately using the second liquid feed pump from the main tank. It is desirable to replenish. The timing of liquid replenishment from the main tank to the circulation tank depends on the detection result of the liquid level sensor installed in the circulation tank, such as when the liquid level of the ink in the circulation tank falls below a predetermined level. Can be controlled.

Next, the circulation of the liquid in the liquid ejection head will be described. As shown in FIG. 1, a supply port 71 that communicates with the common liquid chamber and a circulation port 81 that communicates with the circulation common liquid chamber 50 are formed at the end of the common liquid chamber member 20. The supply port 71 and the circulation port 81 are connected via tubes to a supply tank/circulation tank (see FIG. 7) for storing liquid. Then, the liquid stored in the supply tank is supplied to the individual liquid chamber 6 via the supply port 71, the common liquid chamber 10, the liquid introduction portion 8, and the fluid resistance portion 7.

Further, while the liquid in the individual liquid chamber 6 is ejected from the nozzle 4 by the driving of the piezoelectric element 12, a part or all of the liquid remaining in the individual liquid chamber 6 without being ejected is circulated by the fluid resistance portion 51. It is circulated to the circulation tank through the flow paths 52 and 53, the circulation common liquid chamber 50, and the circulation port 81.

The liquid circulation described above is illustrated in FIGS. 8 and 9. FIG. 8 is a diagram schematically showing a cross-sectional view taken along the line A-A′ of FIG. 2, and schematically shows by arrows the flow of the liquid supplied to the supply liquid chamber 10 via the supply port 71. FIG. 9 is a diagram schematically showing a cross-sectional view taken along the line BB′ of FIG. 2, in which the flow of the liquid circulated in the circulation port 81 via the circulation flow channels 52 and 53 and the circulation common liquid chamber 50 is schematically indicated by an arrow. Is shown in.

It should be noted that FIG. 9 shows a configuration having a fine drive mechanism. The fine drive mechanism applies a minute pulse to a nozzle that is not ejecting, so that the ink thickened due to drying around the nozzle and the ink behind it. It is a mechanism aimed at maintaining stable ejection by minutely circulating ink and ink.

In the present embodiment, the inflow passage for allowing the liquid to flow into the individual liquid chamber 6 includes the supply port 71, the common liquid chamber 10, the fluid resistance portion 7, etc., but is not limited to this and may be changed as appropriate. It is possible. The outflow passage for letting the liquid out of the individual liquid chamber 6 includes the fluid resistance portion 51, the circulation passage 52, the circulation passage 53, the circulation common liquid chamber 50, the circulation port 81, etc., but is not limited to this. However, it can be changed as appropriate.

The liquid circulation can be performed not only when the liquid ejection head is operating, but also when the operation is stopped. By circulating the liquid in the individual liquid chamber, it is possible to constantly refresh the liquid in the individual liquid chamber and suppress aggregation and sedimentation of the components contained in the liquid, which is preferable.

Further, as in the present case, when the ink contains fine particles that tend to settle, if the ink circulation speed is slow, the fine particles may settle or stick in the circulation path. Then, since the resistance in the circulation path becomes strong, the detection value at the supply side pressure sensor and/or the circulation side pressure sensor becomes small. In that case, the sedimentation portion can be eliminated by controlling the ink circulation speed to increase.

Specifically, if the detection value of the supply side pressure sensor and/or the circulation side pressure sensor falls to a preset lower limit target value (as an example, less than half of the normal pressure), the preset pressure is set. The flow rate is controlled so as to increase to the target pressure (normal pressure) at the rate of change. In this example, the flow rate is increased. The increased flow rate is maintained from the time when the detected value reaches the target pressure to the elapse of a predetermined time. As a result, the settling portion can be eliminated.

Next, an example of an apparatus for ejecting a liquid according to the present invention will be described with reference to FIGS. 10 and 11. FIG. 10 is a plan view of a main part of the apparatus, and FIG. 11 is a side view of a main part of the apparatus.

This device is a serial type device, and the carriage 403 reciprocates in the main scanning direction by a main scanning moving mechanism 493. The main scanning moving mechanism 493 includes a guide member 401, a main scanning motor 405, a timing belt 408 and the like. The guide member 401 is bridged between the left and right side plates 491A and 491B and movably holds the carriage 403. Then, the carriage 403 is reciprocated in the main scanning direction by the main scanning motor 405 via the timing belt 408 spanning between the driving pulley 406 and the driven pulley 407.

A liquid ejection unit 440 having a liquid ejection head 404 according to the present invention is mounted on the carriage 403. The liquid ejection head 404 of the liquid ejection unit 440 ejects liquids of yellow (Y), cyan (C), magenta (M), and black (K), for example. Further, the liquid ejection head 404 is arranged such that a nozzle row composed of a plurality of nozzles is arranged in the sub-scanning direction orthogonal to the main scanning direction and the ejection direction is directed downward.

The liquid is supplied and circulated in the liquid ejection head 404 by a supply/circulation mechanism 494 for supplying the liquid stored outside the liquid ejection head 404 to the liquid ejection head 404. In this example, the supply/circulation mechanism 494 includes a supply tank, a circulation tank, a compressor, a vacuum pump, a liquid feed pump, a regulator (R), and the like. The supply-side pressure sensor is connected between the supply tank and the liquid ejection head, and is connected to the supply passage side connected to the supply pipe port 71 of the liquid ejection head. The circulation side pressure sensor is connected between the liquid ejection head and the circulation tank, and is connected to the circulation flow path side connected to the circulation port 81 of the liquid ejection head.

This apparatus includes a transport mechanism 495 for transporting the sheet 410. The transport mechanism 495 includes a transport belt 412, which is a transport unit, and a sub-scanning motor 416 for driving the transport belt 412.

The conveyance belt 412 adsorbs the sheet 410 and conveys it at a position facing the liquid ejection head 404. The conveyor belt 412 is an endless belt, and is stretched between a conveyor roller 413 and a tension roller 414. The adsorption can be performed by electrostatic adsorption or air suction.

Then, the transport belt 412 is rotated in the sub-scanning direction by the sub-scanning motor 416 rotatably driving the transport roller 413 via the timing belt 417 and the timing pulley 418.

Further, on one side of the carriage 403 in the main scanning direction, a maintenance/recovery mechanism 420 for maintenance/recovery of the liquid ejection head 404 is arranged beside the transport belt 412.

The maintenance/recovery mechanism 420 is composed of, for example, a cap member 421 that caps the nozzle surface (surface on which the nozzles are formed) of the liquid ejection head 404, a wiper member 422 that wipes the nozzle surface, and the like.

The main scanning movement mechanism 493, the supply/circulation mechanism 494, the maintenance/recovery mechanism 420, and the transport mechanism 495 are attached to a housing including side plates 491A and 491B and a back plate 491C.
In this apparatus configured as described above, the sheet 410 is fed onto the transport belt 412 and adsorbed, and the sheet 410 is transported in the sub-scanning direction by the orbital movement of the transport belt 412.

Therefore, by moving the carriage 403 in the main scanning direction and driving the liquid ejection head 404 in accordance with the image signal, the liquid is ejected onto the stopped paper 410 to form an image.

As described above, this apparatus can stably form a high quality image.

Next, an example of the liquid ejection unit will be described with reference to FIG. FIG. 12 is an explanatory plan view of relevant parts of the unit. The liquid ejection device of the present invention may be in the form of a liquid ejection unit.
This liquid ejection unit includes a housing portion including side plates 491A and 491B and a back plate 491C, a main scanning movement mechanism 493, a carriage 403, and a liquid among the members forming the device that ejects the liquid. It is composed of the ejection head 404.

It is also possible to configure a liquid ejection unit in which at least one of the maintenance/recovery mechanism 420 and the supply/circulation mechanism 494 described above is further attached to, for example, the side plate 491B of the liquid ejection unit. Above all, it is preferable to have a circulation mechanism.

In the present application, the “liquid ejection head” is a functional component that ejects and ejects liquid from a nozzle.
The liquid to be ejected is not particularly limited as long as it has a viscosity and a surface tension that can be ejected from the head, but the liquid has a viscosity of 30 mPa·s or less at room temperature and atmospheric pressure, or by heating and cooling. Preferably. More specifically, solvents such as water and organic solvents, colorants such as dyes and pigments, functional compounds such as polymerizable compounds, resins and surfactants, biocompatible materials such as DNA, amino acids, proteins and calcium. , Solutions, suspensions, emulsions, etc. containing edible materials such as natural pigments, etc., such as ink-jet inks, surface treatment solutions, components of electronic devices and light-emitting devices, and formation of electronic circuit resist patterns. It can be used for applications such as a liquid for use in a three-dimensional structure.

Piezoelectric actuators (multilayer piezoelectric element and thin-film piezoelectric element), thermal actuators that use electrothermal conversion elements such as heating resistors, electrostatic actuators that consist of a diaphragm and counter electrode, etc. are used as the energy generation source that ejects liquid What you do is included.

The “liquid ejection unit” is a unit in which functional components and mechanisms are integrated with a liquid ejection head, and is a collection of components related to liquid ejection. For example, the “liquid ejection unit” includes a combination of at least one of the supply/circulation mechanism, the carriage, the maintenance/recovery mechanism, and the main scanning movement mechanism with the liquid ejection head.

Here, the term "integral" means, for example, a liquid discharge head, a functional component, and a mechanism that are fixed to each other by fastening, bonding, engaging, or the like, or one that is movably held with respect to the other. Including. Further, the liquid ejection head, the functional component, and the mechanism may be configured to be detachable from each other.

For example, as a liquid ejection unit, there is one in which a liquid ejection head and a supply/circulation mechanism are integrated. In addition, there is one in which the liquid ejection head and the supply/circulation mechanism are integrated by being connected to each other by a tube or the like. Here, it is also possible to add a unit including a filter between the supply/circulation mechanism of these liquid ejection units and the liquid ejection head.
Further, as a liquid ejection unit, there is one in which a liquid ejection head and a carriage are integrated.

Further, as a liquid ejection unit, there is a unit in which a liquid ejection head and a scanning movement mechanism are integrated so that a liquid ejection head is movably held by a guide member forming a part of the scanning movement mechanism.

Further, as a liquid ejection unit, there is a unit in which a cap member that is a part of a maintenance/recovery mechanism is fixed to a carriage to which a liquid ejection head is attached, and the liquid ejection head, the carriage, and the maintenance/recovery mechanism are integrated. ..

Further, as a liquid ejection unit, there is one in which a tube is connected to a liquid ejection head to which a supply/circulation mechanism or a flow path component is attached, and the liquid ejection head and the supply mechanism are integrated. The liquid from the liquid storage source is supplied to the liquid ejection head via this tube.

The main scanning movement mechanism includes a single guide member. The supply mechanism also includes a tube unit and a loading unit unit.

In the present application, the “device for ejecting liquid” is a device that includes a liquid ejection head or a liquid ejection unit, and drives the liquid ejection head to eject the liquid. The device for ejecting a liquid includes not only a device capable of ejecting a liquid to which a liquid can be attached, but also a device ejecting the liquid toward the air or into the liquid.

This "device for ejecting liquid" can include a means for feeding, carrying, and discharging paper to which liquid can be attached, as well as a pretreatment device, a posttreatment device, and the like.

For example, as an "apparatus for ejecting liquid", an image forming apparatus that is an apparatus for ejecting ink to form an image on a sheet, and for forming a three-dimensional object (three-dimensional object), powder is formed in layers. There is a three-dimensional modeling apparatus (three-dimensional modeling apparatus) that discharges the modeling liquid to the formed powder layer.

Further, the “device for ejecting liquid” is not limited to a device in which a significant image such as characters and figures is visualized by the ejected liquid. For example, it also includes one that forms a pattern or the like that has no meaning per se, and one that models a three-dimensional image.

The above-mentioned "liquid can be adhered" means a liquid to which a liquid can be at least temporarily adhered, which is adhered and fixed, and which is adhered and permeated. Specific examples include recording media such as paper, recording paper, recording paper, film and cloth, electronic substrates, electronic components such as piezoelectric elements, powder layers (powder layers), organ models, inspection cells and other media. Yes, and unless otherwise specified, includes anything to which liquid adheres.

The material of the above-mentioned "liquid can be adhered" may be paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics, etc. as long as the liquid can be adhered even temporarily.
The “liquid” may be any one that has a viscosity and a surface tension that can be ejected from the head, and is not particularly limited, but it is one that has a viscosity of 30 mPa·s or less at normal temperature, normal pressure, or by heating or cooling. Preferably. More specifically, solvents such as water and organic solvents, colorants such as dyes and pigments, functional compounds such as polymerizable compounds, resins and surfactants, biocompatible materials such as DNA, amino acids, proteins and calcium. , Solutions, suspensions, emulsions, etc. containing edible materials such as natural pigments, etc., such as ink-jet inks, surface treatment solutions, components of electronic devices and light-emitting devices, and formation of electronic circuit resist patterns. It can be used for applications such as a liquid for use in a three-dimensional structure.

Further, the “device for ejecting liquid” includes a device in which the liquid ejection head and the device to which the liquid can be attached move relatively, but the device is not limited to this. Specific examples include a serial type device that moves the liquid discharge head, a line type device that does not move the liquid discharge head, and the like.

In addition, as the "apparatus for ejecting liquid", a treatment liquid application device for ejecting the treatment liquid onto the paper in order to apply the treatment liquid to the surface of the paper for the purpose of modifying the surface of the paper, raw materials, etc. There is an injection granulation device that granulates the fine particles of the raw material by injecting a composition liquid in which is dispersed in a solution through a nozzle.

Further, in the terms of the present application, image formation, recording, printing, printing, printing, modeling, etc. are synonymous.

Hereinafter, the present invention will be described more specifically by showing Examples and Comparative Examples, but the present invention is not limited to these Examples. In the following, “%” represents “mass %” unless otherwise specified.

(Preparation example 1)
<Preparation of Polycarbonate Polyurethane Resin Emulsion 1>
1,500 mass of a reaction product of polycarbonate diol (1,6-hexanediol and dimethyl carbonate (number average molecular weight (Mn): 1,200) was placed in a reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer. Parts, 2,2-dimethylolpropionic acid (hereinafter sometimes referred to as “DMPA”) 220 parts by mass, and N-methylpyrrolidone (hereinafter sometimes referred to as “NMP”) 1,347 parts by mass as 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 the mixture was heated to 90° C. to carry out a urethanization reaction for 5 hours to produce isocyanate terminal A 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 of the mixture was taken out, and 5,400 parts by mass of water and 15 parts by mass of triethylamine under vigorous stirring. Was added to the mixed solution.
Next, 1,500 parts by mass of ice is added, and 626 parts by mass of a 35% by mass aqueous solution of 2-methyl-1,5-pentanediamine is added to carry out a chain extension reaction so that the solid content concentration becomes 30% by mass. The solvent was distilled off 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 Manufacturing Co., Ltd.), the minimum film-forming temperature was 55°C.

(Preparation example 2)
<Preparation of acrylic resin emulsion 1>
A reaction vessel equipped with a stirrer, a reflux condenser, a dropping device, and a thermometer was charged with 900 parts by mass of ion-exchanged water and 1 part by mass of sodium lauryl sulfate, and the temperature was raised to 70° C. while substituting with nitrogen while stirring. Maintaining the internal temperature at 70° C., adding 4 parts by mass of potassium persulfate as a polymerization initiator and dissolving it, 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, An emulsion prepared by adding 545 parts by mass of butyl acrylate and 10 parts by mass of methacrylic acid with stirring was continuously added dropwise to the reaction solution over 4 hours. After the dropping was completed, it was held for 3 hours. After the obtained aqueous emulsion was cooled to room temperature, ion-exchanged water and an aqueous sodium hydroxide solution were added to adjust the pH to 8 to obtain an acrylic resin emulsion 1 (solid content concentration: 30% by mass).

(Production Example 1)
-Manufacture of clear ink A-
Polyurethane resin emulsion 1 of Preparation Example 1 (solid content concentration: 30% by mass) 25% by mass, 1,2-propanediol 19% by mass, 1,3-propanediol 11% by mass, 1,2-butanediol 3% by mass 6% by mass of a trade name "FS-300" (produced by DuPont, fluorine-based surface active agent, solid content concentration 40% by mass) as a surfactant, and 36% by mass of high pure water are added and mixed and stirred to prepare a mixture. did.
Then, 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 Co., Ltd.) to prepare a clear ink A.

(Production Examples 2-5)
-Manufacture of clear inks B to F-
Clear Inks B to F were produced in the same manner as in Production Example 1 except that the ink composition shown in Table 1 was changed.

(Example 1)
<Inkjet printing>
In an environment adjusted to a temperature of 25° C.±0.5° C. and 50±5% RH, an inkjet recording device (IPCO GXe- manufactured by Ricoh Co., Ltd.) incorporating the circulation type droplet discharge mechanism shown in FIGS. Printing was performed using a 5500 modified machine, manufactured by Ricoh Company, Ltd. Further, the remodeling machine was provided with a heater (temperature control controller, model: MTCD, manufactured by MISUMI) so that the recording medium can be heated from the back surface before printing, during printing, and after printing. As a result, printing can be performed on the recording medium heated by the 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, the heating conditions, and the print image in the gloss gloss printing mode and the matte gloss printing mode.

-Recording medium-
In the gloss 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 matte gloss print mode, a window film GIY-0305 (transparent polyethylene terephthalate (PET) film, gloss 159 (60° gloss value)) manufactured by Lintec Sign System Co., Ltd. was used as the recording medium 2.

-Heating conditions-
The heating conditions were set to 60° C., 60° C., and 70° C. for the heating temperatures of the respective heaters arranged before printing, during printing, and after printing in the gloss gloss printing mode. In the matte gloss printing mode, the heating temperature of each heater was set to 65°C, 65°C, and 70°C. When the temperature of the recording medium during printing was measured, the recording medium temperature (=Tgloss) in the gloss gloss printing mode was 59°C, and the recording medium temperature (=Tmatter) in the matte gloss printing mode was 64°C.
The temperature of the recording medium during printing was measured with a digital radiation temperature sensor FT-H10 (manufactured by Keyence Corporation).

-Print image-
The image printed in the gloss gloss print mode was a full image with an image resolution of 600 dpi×600 dpi and a printing rate of 100%.
The image printed in the matte gloss print mode was a halftone image having an image resolution of 600 dpi×600 dpi and a printing rate of 40%.

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

In both the matte gloss print mode and the gloss gloss print mode, the clear ink A was directly printed on the recording medium.
Next, the glossiness of the obtained printed matter was measured and the glossy feeling was evaluated as follows. Furthermore, in order to apply a drying load, printing was performed under the conditions shown below, and the ejection stability and nozzle recoverability were evaluated. The results are shown in Table 3.

<Glossiness>
The 60° gloss value of the obtained printed matter was measured using a glossiness measuring device (Microtrigloss, manufactured by BYK). At this time, the glossinesses at arbitrary three points on the surface of the printed portion on which the clear ink A of the printed matter was printed were measured, the average value thereof was defined as Gp, and the glossiness of the recording medium surface of the nonprinted portion was defined as Gm.

<Glossy or matte feeling>
The obtained printed matter was visually evaluated based on the following criteria. The glossy feeling was evaluated in the gloss glossy printing mode, and the matte feeling was evaluated in the matte glossy printing mode. It should be noted that A and B were passed and C was rejected.
[Evaluation criteria]
A: The clear ink printed part feels a glossy or matte feel more clearly than the clear ink unprinted part.
B: The clear ink printed part feels a glossy feeling or a matte feeling stronger than the clear ink unprinted part, but it cannot be understood unless clearly seen.
C: The clear ink printed part does not feel glossy or matte or feels weaker than the clear ink unprinted part.

<Discharge stability>
Under the conditions of a temperature of 32° C.±0.5° C. and 30±5% RH, the above-mentioned printed image was printed, and the obtained printed matter was visually observed and evaluated for streaking, omission, and jet turbulence. The evaluation criteria at this time were as follows: A was passed and B and C were rejected.

[Evaluation criteria]
A: There are no streaks, omissions, and jet turbulences observed in the solid part, or almost none.
B: Streaks, omissions, and jet turbulence are observed in three or more solid areas.
C: No ink is ejected and no image is formed.

<Nozzle recovery>
After leaving the head in a decapped state for 24 hours under the conditions of a temperature of 32° C.±0.5° C. and a temperature of 15±5% RH, a cleaning operation is repeated three times, and then a nozzle check pattern is printed on the VJFN160, and It was evaluated by visually observing whether the nozzle was ejected. The evaluation criteria at this time were as follows: A was passed and B to D were rejected.

[Evaluation criteria]
A: All nozzles are ejected normally.
B: Ink is not ejected from the nozzles less than half of the total.
C: Ink is not ejected from more than half of the nozzles.
D: Ink is not ejected at all.

(Example 2)
In Example 1, the heating conditions are set to 50° C., 50° C., and 70° C. for each heater before printing, during printing, and after printing in the gloss gloss printing mode, and in the matte gloss printing mode, each heater. InkJet printing was performed in the same manner as in Example 1 except that the heating temperatures of No. 1 were set to 70°C, 70°C, and 70°C. With respect to the obtained printed matter, the glossiness was measured in the same manner as in Example 1 to evaluate glossiness, ejection stability, and nozzle recoverability. The results are shown in Table 3.
When the recording medium temperature during printing was measured, the recording medium temperature (=Tgloss) in the gloss gloss printing mode was 49°C, and the recording medium temperature (=Tmatte) in the matte gloss printing mode was 68°C.

(Example 3)
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. With respect to the obtained printed matter, the glossiness was measured in the same manner as in Example 1 to evaluate glossiness, ejection stability, and nozzle recoverability. The results are shown in Table 3.

(Example 4)
Inkjet printing was performed in the same manner as in Example 2 except that the clear ink A in Production Example 1 was changed to the clear ink C in Production Example 3 in Example 2. With respect to the obtained printed matter, the glossiness was measured in the same manner as in Example 1 to evaluate glossiness, ejection stability, and nozzle recoverability. The results are shown in Table 3.

(Example 5)
Inkjet printing was performed in the same manner as in Example 2 except that in Example 2, the clear ink A in Production Example 1 was changed to the clear ink D in Production Example 4. With respect to the obtained printed matter, the glossiness was measured in the same manner as in Example 1 to evaluate glossiness, ejection stability, and nozzle recoverability. The results are shown in Table 3.

(Example 6)
Inkjet printing was performed in the same manner as in Example 2 except that in Example 2, the clear ink A in Production Example 1 was changed to the clear ink E in Production Example 5. With respect to the obtained printed matter, the glossiness was measured in the same manner as in Example 1 to evaluate glossiness, ejection stability, and nozzle recoverability. The results are shown in Table 3.

(Example 7)
Inkjet printing was performed in the same manner as in Example 2 except that in Example 2, the clear ink A in Production Example 1 was changed to the clear ink F in Production Example 6. With respect to the obtained printed matter, the glossiness was measured in the same manner as in Example 1 to evaluate glossiness, ejection stability, and nozzle recoverability. The results are shown in Table 3.

(Comparative Example 1)
Inkjet printing was performed in the same manner as in Example 1 except that the printing apparatus in Example 1 was changed to a modified GXe-5500 machine that did not incorporate a circulation mechanism. With respect to the obtained printed matter, the glossiness was measured in the same manner as in Example 1 to evaluate glossiness, ejection stability, and nozzle recoverability. The results are shown in Table 3.

(Comparative example 2)
Inkjet printing was performed in the same manner as in Example 2 except that the printing apparatus in Example 2 was changed to a modified GXe-5500 machine not incorporating a circulation mechanism. With respect to the obtained printed matter, the glossiness was measured in the same manner as in Example 2 to evaluate glossiness, ejection stability, and nozzle recoverability. The results are shown in Table 3.

(Comparative example 3)
Inkjet printing was performed in the same manner as in Example 4 except that the printing apparatus in Example 4 was changed to a modified GXe-5500 machine that did not incorporate a circulation mechanism. With respect to the obtained printed matter, the glossiness was measured in the same manner as in Example 4, and the gloss feeling, the ejection stability, and the nozzle recoverability were evaluated. The results are shown in Table 3.

(Comparative example 4)
Inkjet printing was performed in the same manner as in Example 5 except that the printing apparatus in Example 5 was changed to a modified GXe-5500 machine that did not incorporate a circulation mechanism. With respect to the obtained printed matter, the glossiness was measured in the same manner as in Example 5 to evaluate glossiness, ejection stability, and nozzle recoverability. The results are shown in Table 3.

(Comparative example 5)
Inkjet printing was performed in the same manner as in Example 7 except that the printing apparatus was changed to a modified GXe-5500 machine that does not incorporate a circulation mechanism. With respect to the obtained printed matter, the glossiness was measured in the same manner as in Example 7, and glossiness, ejection stability, and nozzle recoverability were evaluated. The results are shown in Table 3.

From the results of Tables 2 and 3, regarding the glossiness, according to the comparison between Examples 1 and 2 and Comparative Examples 1 and 2, the glossiness was changed by changing the printing rate and the heating temperature even with the same ink. I found that I could do it.
Regarding the ejection stability, according to the comparison between Examples 1 to 7 and Comparative Examples 1 to 5, it was found that the ejection stability was improved by providing the head with the circulation mechanism.
Regarding the nozzle recoverability, according to the comparison between Examples 1 to 7 and Comparative Examples 1 to 5, by providing the head with a circulation mechanism, the thickening of the ink can be suppressed even under the decap condition where the drying is strong, and It has been found that the cleaning operation can completely restore the nozzle.

The viscosity of the ink used above increases at once due to slight evaporation of water, and the wetting and spreading of the ink coating surface occurs only at the moment of landing. In this way, when the wetting and spreading of the coating film surface of the ink depends on the medium temperature at the time of printing, the surface shape has already been determined even after heating after printing, and the remaining water only evaporates. Therefore, it is considered that the matte tone is not obtained even if the heater temperature after printing is high in the gloss gloss printing mode.

DESCRIPTION OF SYMBOLS 1 Nozzle plate 2 Flow path plate 3 Vibrating plate member 4 Nozzle 6 Individual liquid chamber 6a, 6b, 6c, 6d, 6e Through groove part 7 fluid resistance part 7a Through groove part 8a which is a fluid resistance part Liquid introduction part 8a, 8b through-groove part which constitutes a liquid introduction part 9 filter part 10 common liquid chamber 10A downstream common liquid chamber 10a through groove part 10B upstream common liquid chamber 10b groove part 11 piezoelectric actuator 12 piezoelectric member 12A, 12B piezoelectric element 13 base member 15 Flexible wiring member 20 Common liquid chamber member 21 First common liquid chamber member 22 Second common liquid chamber member 25a, 25b Piezoelectric actuator through hole 29 Cover 30 Vibration region 30a, 30b Convex portion 40 Flow path member 41 to 45 Plate member 50 circulation common liquid chamber 50a groove portion 51 fluid resistance portion 51a through groove portion 52, 53 forming a fluid resistance portion 52a, 52b through groove portions 53a, 53b, 53c, 53d forming a circulation passage forming a circulation passage Through groove portion 71 Supply port 71a Through hole 81 Circulation port 81a, 81b Through hole

JP, 2005-3397, A JP, 2009-208348, A

Claims (12)

A device for ejecting a liquid, comprising: a liquid containing portion that contains a liquid; a liquid ejection head that ejects the liquid onto a print target; and a heating unit that heats the print target,
It has a matte gloss print mode that is a print mode that imparts a matte gloss, and a gloss gloss print mode that is a print mode that imparts a gloss gloss,
The liquid ejection head includes an individual liquid chamber that communicates with a nozzle through which the liquid is ejected, an inflow passage that allows the liquid to flow into the individual liquid chamber, and an outflow of the liquid from the individual liquid chamber. An outflow passage,
The liquid is a clear ink containing a resin, and is circulated through the inflow passage and the outflow passage,
In the landing area when the liquid lands on the printing object in the matte gloss printing mode, the heating unit changes the temperature for heating the printing object in the matte gloss printing mode and the gloss gloss printing mode. When the temperature of the substrate is T _matte [° C.] and the temperature of the substrate in the landing area when the liquid lands on the substrate in the gloss gloss print mode is T _gloss [° C.], T _matte A device for ejecting a liquid, characterized in that the substrate is heated so as to be >T _gloss . The apparatus for ejecting a liquid according to claim 1, wherein the heating unit heats the printing object such that T _matte −T _gloss ≧10 [° C.]. A device for ejecting a liquid, comprising: a liquid containing portion that contains a liquid; a liquid ejection head that ejects the liquid onto a print target; and a heating unit that heats the print target,
It has a matte gloss print mode that is a print mode that imparts a matte gloss, and a gloss gloss print mode that is a print mode that imparts a gloss gloss,
The liquid ejection head includes an individual liquid chamber that communicates with a nozzle through which the liquid is ejected, an inflow passage that allows the liquid to flow into the individual liquid chamber, and an outflow of the liquid from the individual liquid chamber. An outflow passage,
The liquid is a clear ink containing a resin, and is circulated through the inflow passage and the outflow passage,
When the heating temperature of the heating unit in the matte gloss printing mode is HT _matte [°C] and the heating temperature of the heating unit in the gloss gloss printing mode is HT _gloss [°C], HT _matte >HT _gloss is satisfied. An apparatus for ejecting a liquid characterized by. The apparatus for discharging a liquid according to claim 3, wherein the heating temperature of the heating unit is HT _matte- HT _gloss ≧10 [° C.]. G _matte >G _gloss, where G _matte is the glossiness of the substrate to be used in the _matte gloss print mode and G _gloss is the glossiness of the substrate to be used in the gloss gloss print mode. An apparatus for ejecting the liquid according to claim 1. The apparatus for discharging a liquid according to claim 1, wherein the resin is contained in the liquid in an amount of 8% by mass or more. The device for discharging a liquid according to claim 1, wherein the resin is a polyurethane resin. The liquid contains a surfactant,
The apparatus for ejecting a liquid according to claim 1, wherein the surfactant is contained in the liquid in an amount of 2% by mass or less. The liquid ejecting apparatus according to claim 8, wherein the surfactant is a fluorine-based surfactant. A printing method comprising: a printing step of ejecting a liquid onto a printing object by a liquid ejection head; and a heating step of heating the printing object,
It has a matte gloss print mode that is a print mode that imparts a matte gloss, and a gloss gloss print mode that is a print mode that imparts a gloss gloss,
The liquid ejection head includes an individual liquid chamber that communicates with a nozzle through which the liquid is ejected, an inflow passage that allows the liquid to flow into the individual liquid chamber, and an outflow of the liquid from the individual liquid chamber. An outflow passage,
The liquid is a clear ink containing a resin, and is circulated through the inflow passage and the outflow passage,
In the heating step, the temperature at which the substrate is heated is different between the matte gloss print mode and the gloss glossy print mode, and in the landing area when the liquid is landed on the substrate in the matte gloss print mode. When the temperature of the substrate is T _matte [° C.] and the temperature of the substrate in the landing area when the liquid lands on the substrate in the gloss gloss print mode is T _gloss [° C.], T _matte A printing method comprising heating the substrate so as to satisfy &gt;T _gloss . A method for controlling the glossiness of a printed image, comprising: a printing step of ejecting a liquid onto a printed material by a liquid ejection head; and a heating step of heating the printed material,
It has a matte gloss print mode that is a print mode that imparts a matte gloss, and a gloss gloss print mode that is a print mode that imparts a gloss gloss,
The liquid ejection head includes an individual liquid chamber that communicates with a nozzle through which the liquid is ejected, an inflow passage that allows the liquid to flow into the individual liquid chamber, and an outflow of the liquid from the individual liquid chamber. An outflow passage,
The liquid is a clear ink containing a resin, and is circulated through the inflow passage and the outflow passage,
In the heating step, the temperature at which the substrate is heated is different between the matte gloss print mode and the gloss glossy print mode, and in the landing area when the liquid is landed on the substrate in the matte gloss print mode. When the temperature of the substrate is T _matte [° C.] and the temperature of the substrate in the landing area when the liquid lands on the substrate in the gloss gloss print mode is T _gloss [° C.], T _matte A method for controlling the glossiness of a printed image, which comprises heating the printed material so as to satisfy T _gloss . A printing method comprising: a printing step of ejecting a liquid onto a printing object by a liquid ejection head; and a heating step of heating the printing object,
It has a matte gloss print mode that is a print mode that imparts a matte gloss, and a gloss gloss print mode that is a print mode that imparts a gloss gloss,
The liquid ejection head includes an individual liquid chamber that communicates with a nozzle through which the liquid is ejected, an inflow passage that allows the liquid to flow into the individual liquid chamber, and an outflow of the liquid from the individual liquid chamber. An outflow passage,
The liquid is a clear ink containing a resin, and is circulated through the inflow passage and the outflow passage,
When the temperature of the heating unit in the matte gloss printing mode is HT _matte [° C.] and the temperature of the heating unit in the gloss gloss printing mode is HT _gloss [° C.], HT _matte >HT _gloss is satisfied. And the printing method.