JP2009006544A - Recorded medium and ink jet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recorded medium capable of forming a high-quality image with high image quality, and an ink jet recording device capable of forming a high-quality printed matter with high image quality at high speed. <P>SOLUTION: The recorded medium comprises a substrate, a plurality of microcapsules applied to the surface of the substrate, the microcapsules being filled with active energy beam-hardenable liquid. The ink jet recording device for forming an image on the recorded medium of this structure comprises a microcapsule breakage means, an image forming means and an active energy beam irradiation means. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a recording medium on which an image is recorded, and an ink jet recording apparatus that uses the recording medium and ejects ink droplets from an ink jet head to record an image on the recording medium.

As a method of forming an image on a recording medium, there is a method of forming an image by ejecting ink droplets from an inkjet head.
As an image recording apparatus using an inkjet head, for example, Patent Document 1 discloses an ink having two or more colors in an inkjet recording method in which an ink having a compound curable by actinic rays is printed on a recording medium by an inkjet method and cured. Describes an ink jet recording apparatus using an ink jet recording method in which image formation is performed and all the ink necessary for image formation is ejected and then the actinic ray is irradiated within 10 seconds.
Patent Document 1 also describes an ink jet recording apparatus that irradiates actinic rays at a downstream portion in the transport direction within 10 seconds after ink is ejected for each color by a line head.

Further, in Patent Document 2, an inkjet head that discharges ink curable by irradiation with actinic rays to a recording medium and white ink curable by irradiation with actinic rays are applied onto the recording medium by a method other than inkjet. An ink jet printer including a means for applying the ink and continuously performing the application of the white ink and the printing by the ink jet head.
A first irradiating means for irradiating actinic light for curing the white ink after applying the white ink; and a second irradiating means for irradiating the actinic light for curing the ink after the ink is ejected. Inkjet printers are also described.
Further, as a method for applying white ink, it is described that application is performed using spray coating, roll coating, gravure coating, air knife coating, extrusion coating, curtain coating, wire bar coating, or felt coating.

  Further, in Patent Document 3, an ink jet receiving layer formed using an ink for ink jet receiving layer formation comprising at least a microcapsule enclosing a water-repellent substance and a hydrophilic solution in which the microcapsule is dispersed is provided as a sheet. There is described an information carrying sheet characterized in that it is arranged on one side or a part of or both sides of the sheet.

JP 2003-11341 A JP 2004-42525 A JP 2005-59418 A

As described in the cited document 1, a color image can be formed by forming an image with a multicolor ink jet head.
Further, as described in the cited document 2, a white ink is applied to the surface of the recording medium, that is, after the surface layer is formed on the surface of the recording medium in advance, the ink is applied to the recording medium on which the surface layer is formed. By ejecting the liquid, an image having good visibility can be formed even on a light-transmitting recording medium, a recording medium with low brightness, and a metal surface.
Further, as described in the cited document 2, a surface layer in which scanning stripes are not noticeable in a shorter time than when an ink jet head is used by applying white ink by a method other than a method using an ink jet head. Can be formed.

  In this way, by forming a surface layer in advance on the recording medium with white ink or the like, an image having good visibility even on a translucent recording medium, a recording medium with low brightness, and a metal surface. Can be formed.

However, when an image is recorded on a recording medium by the image recording apparatuses described in Cited Document 1 and Cited Document 2, the position of the ink droplets that have landed on the recording medium may be displaced, the image may be blurred, and the like. There is a problem that it is difficult to record a high-quality image.
Further, the information carrying sheet described in the cited document 3, that is, the recording medium, has a stable ink absorbability with respect to the water-based ink by providing a hydrophilic inkjet receiving layer, and is included after image recording. Water resistance can be improved by breaking microcapsules and increasing water repellency. However, when printing is performed on a recording medium having an ink-absorbing receiving layer using ink that is cured by actinic rays (active energy rays), the ink absorbed in the ink-absorbing receiving layer is irradiated even when irradiated with actinic rays. Since actinic rays cannot reach, there is a problem that curing failure occurs and an image having poor scratch resistance is formed.

An object of the present invention is to provide a recording medium capable of forming a high-quality image by an inkjet recording method.
An object of the present invention is to provide an ink jet recording apparatus capable of solving the problems based on the above prior art and producing high-quality, high-quality printed matter at high speed.

  In order to solve the above-described problem, a first aspect of the present invention includes a base material and a coating layer including a plurality of microcapsules coated on the surface of the base material, and the microcapsules are disposed therein. An object of the present invention is to provide a recording medium filled with an active energy ray-curable liquid.

Here, the liquid filled in the microcapsules is preferably a liquid containing a radical polymerizable composition.
Further, after the plurality of microcapsules of the coating layer are ruptured, the filled liquid has a thickness of preferably 1 μm to 20 μm, more preferably 1 μm to 3 μm. It is good to contain the liquid quantity which forms the following liquid films.

  In order to solve the above problems, a second aspect of the present invention is an ink jet recording apparatus for forming an image on a recording medium according to any one of the first aspect, wherein the plurality of micros of the recording medium are Microcapsule breaking means for rupturing a capsule to form a liquid film with the liquid contained in the plurality of microcapsules on the base material, and on the recording medium on which the liquid film is formed on the base material And an image forming means for forming an image by ejecting ink that contains at least a coloring material and is cured when irradiated with active energy rays, and irradiating the recording medium on which the image is formed with active energy rays. And an active energy ray irradiating means for curing the image.

Here, it is preferable that the ink jet recording apparatus further includes a semi-curing unit that irradiates the liquid film of the recording medium with an active energy ray and semi-cures the liquid film.
In addition, the image forming unit includes a plurality of inkjet heads arranged in the conveyance direction of the recording medium, and is further disposed between the inkjet heads in the conveyance direction, and the inkjet on the upstream side in the conveyance direction. It is preferable to include an ink semi-curing unit that semi-cures the ink by irradiating the ink that is ejected from the head and forms the image on the recording medium with an active energy ray.

According to the first aspect of the present invention, it is possible to form a liquid film before image recording by rupturing the microcapsules, and it is possible to record a high-quality image by the ink jet recording method.
In addition, since a liquid film can be formed without providing a liquid film coating means, the configuration of the ink jet recording apparatus used for image recording can be simplified, and the number of maintenance of the apparatus can be reduced or eliminated. be able to.

  Further, according to the second aspect of the present invention, a liquid film can be formed on the surface of the recording medium on which an image is recorded by providing capsule destruction means and rupturing the microcapsules of the recording medium. Thus, it is possible to produce a printed material on which a high-quality image is formed with a simple configuration. Furthermore, the number of maintenance of the apparatus can be reduced or eliminated.

  The recording medium according to the first aspect of the present invention and the ink jet recording apparatus according to the second aspect of the present invention will be described in detail based on the embodiments shown in the accompanying drawings.

FIG. 1 is a side view showing a schematic configuration of an example of a recording medium of the present invention.
As shown in FIG. 1, the recording medium P includes a substrate 2 and a microcapsule coating layer (hereinafter referred to as a capsule layer) 6 coated on the surface of the substrate 2. Here, the capsule layer 6 is dispersed in a binder in which the microcapsule 4 serves as an adhesive layer.

  The substrate 2 is a sheet-like member, and various materials such as paper such as high-quality paper and synthetic paper, and plastic films such as PET and PP can be used.

The microcapsule 4 is filled with an active energy ray-curable liquid inside the microcapsule wall, and is applied to the surface of the substrate 2 in a state of being dispersed in a binder, and is laminated in the binder in FIG. The capsule layer 6 is formed.
As the microcapsule 4, various types of capsules such as a capsule that bursts when pressure is applied and a capsule that bursts when heat is applied can be used.

  Here, as the microcapsule wall, it is preferable to use one having a property of being three-dimensionally crosslinked and swollen by a solvent. Specifically, the microcapsule wall is preferably formed of polyurea, polyurethane, polyester, polycarbonate, polyamide, and a mixture thereof, and particularly preferably formed of polyurea and polyurethane. Further, a compound having a crosslinkable functional group such as an ethylenically unsaturated bond capable of introducing a binder polymer may be introduced into the microcapsule wall.

The inside of the microcapsule wall is filled with an active energy ray-curable liquid. That is, it is necessary to use an active energy ray-curable liquid as a liquid to be filled into the microcapsule 4, more precisely, as a liquid to be filled into the microcapsule wall (hereinafter also referred to as “encapsulated liquid”). Here, in this invention, it is preferable that the active energy ray hardening-type liquid as an inclusion liquid with which the microcapsule 4 is filled is a liquid containing a radically polymerizable composition. In addition, although mentioned later for details, as a liquid containing a radically polymerizable composition, DPGDA (Dipropylene glycol diacrylate; Daicel-Cytec Co., Ltd. product, polyfunctional monomer) is 85. 9% by mass, 3.0% by mass of A-DPH (dipentaerythritol hexaacrylate; Shin-Nakamura Chemical Co., Ltd., polyfunctional monomer)), and BYK-307 (Bic Chemie)) as a surfactant) 0% by mass, 0.1% by mass of FIRSTCURE ST-1 (manufactured by Albemarle) as a polymerization inhibitor, 9.0% by mass of DAROCUR TPO (manufactured by Ciba Specialty Chemicals) as a photopolymerization initiator, sensitizer Speedcure DETX (2,4 diethylthioxanthone, manufactured by Lambson) as 1.0 A liquid mixed at a ratio of mass% can be used.
The inclusion liquid that can be suitably used in the present invention will be described later.

  Such microcapsules can be manufactured by various manufacturing methods. For example, as a method for producing microcapsules, US Pat. No. 2,800,547, US Pat. No. 2,800,498, a method using coacervation, US Pat. No. 3,287,154, Japanese Patent Publication No. 38-19574, The method by the interfacial polymerization method found in US Pat. No. 42-446, the method by the precipitation of polymer found in US Pat. Nos. 3,418,250 and 3,660,304, the isocyanate found in US Pat. No. 3,796,669 Method using polyol wall material, method using isocyanate wall material found in US Pat. No. 3,914,511, urea found in US Pat. Nos. 4,001,140, 4,087,376 and 4,089,802 -Formaldehyde or urea formaldehyde -A method using a resorcinol-based wall forming material, a method using a wall material such as melamine-formaldehyde resin, hydroxycellulose, etc. found in US Pat. No. 4,025,445, Japanese Patent Publication Nos. 36-9163 and 51-9079. In-situ method by monomer polymerization, British Patent No. 930422, US Pat. No. 3,111,407 Spray drying method, British Patent No. 952807, US Pat. No. 9,670,741 Although there is a cooling method, it is not limited to these.

Hereinafter, a specific example of the manufacturing method of a macrocapsule is shown.
First, as the oil component of the microcapsule, 10.0 g of trimethylolpropane and xylene diisocyanate adduct (manufactured by Mitsui Takeda Chemical Co., Ltd., Takenate D-110N, 75 mass% ethyl acetate solution) and the above-mentioned microcapsule inclusion liquid 6.0 g was dissolved in 16.67 g of ethyl acetate. Further, 4% by mass of PVA-205 and 37.5 g of an aqueous solution were prepared as an aqueous phase component of the microcapsule.
The oil phase component and the aqueous phase component thus prepared were mixed and emulsified at 12000 rpm for 10 minutes using a homogenizer.
Thereafter, the obtained emulsion was added to 25 g of distilled water, stirred at room temperature for 30 minutes, and then stirred at 40 ° C. for 2 hours. In this way, microcapsules were produced.
Furthermore, the solid content concentration of the microcapsule solution thus obtained was diluted with distilled water so as to be 21% by mass, to prepare a microcapsule dispersion.
The average particle diameter of the produced microcapsules was 0.53 μm.
Even by such a method, microcapsules can be produced. Moreover, according to the said manufacturing method, the microcapsule dispersion liquid which disperse | distributed the microcapsule can also be manufactured.

  Here, the average particle size of the microcapsules is preferably 0.01 to 3.0 μm, more preferably 0.05 to 2.0 μm, and particularly preferably 0.10 to 1.0 μm. By setting the average particle size of the microcapsules within the above range, good resolution and stability over time can be obtained.

  The capsule layer 6 is composed of a microcapsule 4 and a binder used when the microcapsule 4 is applied onto the base material 2, and the microcapsule 4 applied to the surface of the base material 2 by the binder that functions as an adhesive layer. 2 is adhered. Here, as the binder resin used as the adhesive layer, derivatives modified with polyvinyl alcohol and silanol groups, oxidized starch, modified starch such as etherification, esterification, grafting, gelatin, casein, carboxymethylcellulose Cellulose derivatives such as polyvinyl pyrrolidone, water-soluble polyester resin, water-soluble polyacrylate resin, water-soluble polycarbonate resin, water-soluble polyvinyl acetate resin, water-soluble styrene acrylate resin, water-soluble vinyl toluene acrylate resin, water-soluble polyurethane resin Water-soluble polyamide resins, water-soluble urea resins, water-soluble polycaprolactone resins, water-soluble polystyrene resins, water-soluble polyvinyl chloride resins, water-soluble polyacrylate resins, water-soluble polyacrylonitrile resins, and the like Styrene-butadiene copolymers, acrylic acid ester copolymer, polyvinyl acetate, ethylene-vinyl acetate copolymers and the like.

  In addition, the manufacturing method of the recording medium P is not particularly limited, and the capsule layer 6 is formed by dispersing the microcapsules 4 in the above-described binder serving as an adhesive layer, coating the substrate 2 and drying it. A method for producing the recording medium P is exemplified, and a binder type is appropriately selected according to production conditions, print quality, and required performance.

Here, the recording medium P can be manufactured by applying a microcapsule dispersion liquid in which microcapsules are dispersed in a binder at a predetermined solid content concentration on a substrate.
As a specific example, neutral paper having a basis weight of 70 g / m ² is used as a base material, and the above-described microcapsule dispersion is applied on the base material with an air knife coater so as to have a solid content of 8 g / m ^2. By forming a microcapsule coating layer, a recording medium could be manufactured.
The application method is not particularly limited, and various application methods such as a spray coater and a roll coater can be used.

The recording medium P is basically configured as described above.
FIG. 2 is a side view showing a schematic configuration of an example of a recording medium after the microcapsule is ruptured.
In the recording medium P, when the microcapsule 4 is ruptured, as shown in FIG. 2, an active energy ray-curable liquid film (hereinafter simply referred to as “liquid film”) filled in the microcapsule 4 on the substrate 2. Is also formed).
Therefore, the liquid film 8 can be formed on the substrate 2 by rupturing the microcapsules before ejecting ink droplets onto the recording medium P and recording an image.
By landing the ink droplets on the recording medium on which the liquid film 8 is formed in this way, the ink droplets that have landed on the adjacent positions move and coalesce, and the ink droplets spread and get wet. Can be suppressed, and bleeding of the image can be prevented.
As a result, a high-quality image can be formed on the recording medium P.

Further, a liquid film can be formed on a recording medium simply by rupturing the microcapsule during image recording. This eliminates the need to apply the liquid film with the ink jet recording apparatus, thereby simplifying the configuration of the ink jet recording apparatus. Further, when the application unit is provided, it is not necessary to perform the maintenance of the application unit necessary for stably forming the liquid film.
Thus, by using the recording medium of the present invention, the configuration of the ink jet recording apparatus can be simplified, and the maintainability of the ink jet recording apparatus can be improved.
Furthermore, since a liquid film having a stable thickness can be formed by the macrocapsule, it is possible to stably produce a high-quality printed matter.

In addition, by using an active energy ray-curable liquid as the liquid to be filled in the microcapsules, the liquid film can be cured by polymerizing by irradiating active energy rays such as ultraviolet rays after image formation. . Here, the “active energy ray” is not particularly limited as long as it can impart an energy capable of generating a starting species to the active energy ray-curable liquid by irradiation. For example, α ray, γ Rays, X-rays, ultraviolet rays, visible rays, electron beams, and the like.
As a result, the image and the liquid film can be cured at the same time, the apparatus configuration can be simplified, and a printed matter can be produced more easily.

Further, by using an active energy ray curable liquid as the liquid to be filled in the microcapsules, the liquid film can be semi-cured by irradiating the liquid film formed on the substrate with the active energy rays.
Here, as the active energy ray-curable liquid filled in the microcapsules, it is preferable to use a liquid containing a radical polymerizable composition. Thus, by using the liquid containing the radical polymerizable composition as the active energy ray curable liquid, the curing and semi-curing of the liquid film can be controlled more easily.

  In the present invention, “semi-cured” means partially cured (partially cured), which means a state in which the liquid film 8 is partially cured but not completely cured. In addition, when the liquid film 8 formed on the base material 2 is semi-cured, the degree of curing may be non-uniform, and the liquid film is preferably cured in the depth direction.

  For example, when the liquid film 8 having a radical polymerizable composition is cured in air or in air partially substituted with an inert gas, radicals are formed on the surface of the liquid film 8 due to the polymerization inhibiting action by oxygen. The polymerization reaction tends to be inhibited. As a result, the semi-curing becomes non-uniform, the curing proceeds more inside the liquid film 8, and the surface curing tends to be delayed.

  In the present invention, the liquid film 8 having a radical polymerizable composition is used in the presence of polymerization-inhibiting oxygen and partially photocured, whereby the degree of cure of the liquid film 8 is higher than that of the outside. Can be higher.

  As described above, when the liquid film 8 on the substrate 2 of the recording medium P is semi-cured and the ink liquid is ejected onto the semi-cured liquid film 8, a technical effect favorable to the quality of the obtained printed matter. Can be obtained. Moreover, the action mechanism can be confirmed by observing the cross section of the printed matter.

Hereinafter, the semi-curing of the liquid film (that is, the liquid film formed on the recording medium with an inclusion liquid composed of an active energy ray-curable liquid, for example, a liquid having a radical polymerizable composition) 8 will be described in detail. To do. In the following, when about 12 pL of ink liquid (that is, ink droplet) is ejected onto the semi-cured liquid film 8 having a thickness of about 5 μm provided on the substrate 2. A high density portion will be described as an example.
FIG. 3 is a schematic cross-sectional view showing an example of a recording medium in which an ink liquid is ejected onto a semi-cured liquid film 8, and FIGS. 4A and 4B show the uncured liquid, respectively. FIG. 4C is a schematic cross-sectional view showing an example of a recording medium on which an ink liquid is ejected onto a film 8, and FIG. 4C is a diagram illustrating a state in which the ink liquid is ejected onto the completely cured liquid film 8. It is a typical sectional view showing an example of a recording medium.

According to the present invention, the liquid film 8 is semi-cured, so that the degree of cure on the substrate 2 side is higher than the degree of cure of the surface layer. In this case, three features are observed. That is, as shown in FIG. 3, when the ink liquid d is deposited on the semi-cured liquid film 8, (1) a part of the ink liquid d comes out on the surface of the liquid film 8, (2) the ink liquid A part of d is embedded in the liquid film 8, and (3) the liquid film 8 exists between the lower side of the ink liquid d and the substrate 2.
As described above, when the ink film is ejected onto the liquid film and the liquid film and the ink liquid satisfy the above conditions (1), (2), and (3), the liquid film is in a semi-cured state. It can be said that there is.
By semi-curing the liquid film, that is, by curing the liquid film so as to satisfy the above (1), (2), and (3), droplets of ink liquid that has been ejected with high density (that is, Ink droplets) are connected to each other to form an ink liquid film layer (that is, an ink liquid film or an ink layer), which gives uniform and high color density.

On the other hand, when the ink liquid is ejected onto the uncured liquid film 8, all of the ink liquid d is immersed in the liquid film 8 and / or as shown in FIG. As shown in (B), the liquid film 8 does not exist below the ink liquid d.
In this case, even when the ink liquid is applied at a high density, the droplets are independent of each other, which causes a decrease in color density.

Further, when the ink liquid is ejected onto the completely cured liquid film 8, the ink liquid d does not enter the liquid film 8 as shown in FIG.
In this case, droplet ejection interference occurs, a uniform ink liquid film layer cannot be formed, and color reproducibility cannot be increased (that is, color reproducibility is reduced).

Here, when droplets of ink liquid are applied at high density, the droplets do not become independent, from the viewpoint of forming a uniform ink liquid film layer, and from the viewpoint of suppressing the occurrence of droplet ejection interference, The amount of the uncured portion of the liquid film per unit area (that is, the inclusion liquid constituting the liquid film) is preferably smaller than the maximum droplet amount of the ink liquid applied per unit area, and sufficiently small. More preferred. That is, the weight M _u (also referred to as M (liquid film)) of the uncured portion of the liquid film and the maximum weight m _i (also referred to as m (ink liquid)) of the ink liquid ejected per unit area. Is preferably satisfied (m _i / 30) <M _u <m _i , more preferably (m _i / 20) <M _u <(m _i / 3), and (m _i / 10) It is particularly preferable to satisfy <M _u <(m _i / 5). Here, the maximum weight of the ink liquid ejected per unit area is the maximum weight per color.
By setting (m _i / 30) <M _u , the occurrence of droplet ejection interference can be prevented, and the dot size reproducibility can be increased. Further, by setting M _u <m _i , the liquid layer of the ink liquid can be formed uniformly, and the decrease in density can be prevented.

Here, the weight M _{u of the} uncured portion of the liquid film per unit area is obtained by a transfer test. Specifically, after completion of the semi-curing process (for example, after irradiation of active energy rays) and before ink droplets are ejected, a penetrating medium such as plain paper is pressed against the semi-cured liquid film. Then, the amount of the liquid film transferred to the permeation medium is measured by weight measurement, and the measured value is defined as the weight of the uncured portion of the liquid film.
For example, the maximum amount of the second ink, in droplet deposition density of 600 × 600 dpi, per 1 pixel, is set to 12 picoliters, the maximum weight _{m i} of the ink ejected per unit area, 0.74 mg / cm ² (The density of the ink liquid is about 1.1 g / cm ³ ). Therefore, in this case, the weight _{M u} uncured portions per unit area of the liquid film, it is preferable that the 0.025 mg / cm ² or more 0.74 mg / cm ² or less, 0.037 mg / cm ² or more 0 more preferably to .25mg / cm ² or less, and particularly preferably 0.074 mg / cm ² or more 0.148 mg / cm ² or less.

Thus, the recording medium P of the present invention can make the liquid film in a semi-cured state by forming the liquid film with the liquid containing the radical polymerizable composition.
As described above, since the liquid film can be semi-cured, a high-quality image can be formed.
Specifically, even if the ink droplets land on the recording medium with overlapping portions, the interaction between the adjacent ink droplets is caused by the interaction between the semi-cured ink layer and the ink droplets. One can be suppressed.
In other words, when a liquid film is formed on the surface of the recording medium on which an image is to be formed and ink droplets ejected from the recording head land close to the recording medium, for example, a single color ink liquid Ink droplets can be prevented from moving even when the droplets land on the recording medium with overlapping portions or when ink droplets of different colors land on the recording medium with overlapping portions. .
As a result, it is possible to effectively prevent the occurrence of blurring of the image, non-uniformity of the line width such as fine lines in the image, and the occurrence of color unevenness on the colored surface. Inkjet images having a high droplet ejection density such as letters can be recorded with good reproducibility of fine images such as fine lines.

Here, the viscosity (25 ° C.) of the inner layer of the semi-cured liquid film is preferably 5000 mPa · s or more.
Moreover, it is preferable that the viscosity (25 degreeC) of the surface layer of a semi-hardened liquid film is 100 mPa * s or more and 5000 mPa * s or less.
Further, the viscosity (25 ° C.) of the inner layer of the semi-cured liquid film is preferably 1.5 times or more of the viscosity (25 ° C.) of the surface layer of the semi-cured liquid film, and is preferably 2 times or more. Is more preferable, and it is further more preferable that it is 3 times or more.
When the liquid film, that is, the liquid to be filled in the microcapsule satisfies the above range, a high-quality image can be formed more reliably. That is, it is preferable to use a liquid that changes to a value in the above range when cured as the liquid to be filled in the microcapsules.

Further, the polymerization degree of the polymerizable compound on the surface of the semi-cured liquid film is preferably 1% or more and 70% or less, more preferably 5% or more and 60% or less, and 10% or more and 50% or less. It is particularly preferred that Here, the degree of polymerization can be measured by IR or the like.
The liquid film, that is, the liquid filled in the microcapsules can more reliably form a high-quality image. That is, it is preferable to use a liquid that changes to a value in the above range when cured as the liquid to be filled in the microcapsules.

  Further, in the recording medium P, it is preferable to fill the microcapsule 4 with a liquid amount in which the thickness of the liquid film 8 formed on the substrate 2 is 1 μm or more and 20 μm or less.

Further, in the recording medium P, it is preferable that the microcapsule 4 is filled with a liquid amount in which the thickness of the liquid film 8 formed on the substrate 2 is 1 μm or more and 3 μm or less.
By setting the liquid film formed on the substrate 2 to 1 μm or more and 3 μm or less, it is possible to suppress interference and bleeding between the ink droplets that have landed in the same manner as when the liquid film is semi-cured without being semi-cured. And a higher quality image can be formed. Further, the amount of liquid can be reduced and the recording medium can be made thinner.

  Hereinafter, the inclusion liquid that can be suitably used as the active energy ray-curable liquid filled in the microcapsules of the recording medium of the present invention will be described in detail.

(Physical properties of inclusion liquid)
Here, the viscosity (25 ° C.) of the inclusion liquid before internal curing is preferably 10 to 500 mPa · s, and more preferably 50 to 300 mPa · s.

In the present invention, from the viewpoint of forming dots of a target size on a recording medium (more precisely, a liquid film formed from the inclusion liquid), the inclusion liquid preferably contains a surfactant, It is more preferable to satisfy all of the following conditions (A), (B) and (C).
(A) The surface tension of the inclusion liquid is smaller than the surface tension of any ink ejected onto the recording medium.
(B) At least one of the surfactants contained in the inclusion liquid is
γs (0) −γs (saturation)> 0 (mN / m)
Satisfy the relationship.
(C) The surface tension of the inclusion liquid is
γs <(γs (0) + γs (saturation) ^max ) / 2
Satisfy the relationship.

Here, γs is the value of the surface tension of the inclusion liquid. γs (0) is the value of the surface tension of the liquid excluding all surfactants in the composition of the inclusion liquid. γs (saturation) is obtained when one surfactant among the surfactants contained in the inclusion liquid is added to the “liquid excluding all surfactants” and the concentration of the surfactant is increased. The surface tension value of the liquid with the surface tension saturated. γs (saturation) ^max is the maximum value of γs (saturation) obtained for all surfactants satisfying the condition (B) among the surfactants contained in the inclusion liquid.

<Condition (A)>
In the present invention, as described above, in order to form an ink dot of a target size on a recording medium, it is preferable that the surface tension γs of the inclusion liquid is smaller than the surface tension γk of any ink. .
Further, from the viewpoint of more effectively preventing the expansion of ink dots from landing to exposure, γs <γk-3 (mN / m) is more preferable, and γs <γk-5 (mN / m). It is particularly preferred that
In the case of forming (printing or drawing) a full-color image, from the viewpoint of improving the sharpness of the image, the surface tension γs of the inclusion liquid is at least higher than the surface tension of the ink containing the colorant having high visibility. It is preferable to make it smaller, and it is more preferred to make it smaller than the surface tension of all inks. Examples of the colorant having high visibility include colorants exhibiting magenta, black, and cyan colors.

Further, from the viewpoint of proper ejection, the surface tension γk of the ink and the surface tension γs of the inclusion liquid satisfy the above relationship, and the surface tension γk of the ink and the surface tension γs of the inclusion liquid are 15 mN / m, respectively. It is preferably in the range of 50 mN / m or less, more preferably in the range of 18 mN / m or more and 40 mN / m or less, and particularly preferably in the range of 20 mN / m or more and 38 mN / m or less.
By setting both values to 15 mN / m or more, it is possible to suitably form droplets at the time of droplet ejection by the inkjet head, and it is possible to prevent non-ejection. That is, ink droplets can be suitably discharged. Moreover, by setting it as 50 mN / m or less, wettability with an inkjet head can be made high and an ink droplet can be discharged suitably. That is, it is possible to prevent non-ejection of droplets. By setting both values within the range of 18 mN / m or more and 40 mN / m or less, and further within the range of 20 mN / m or more and 38 mN / m or less, the above-described effects can be obtained more suitably, and ink droplets can be obtained. Can be reliably discharged.
Here, in the present embodiment, the surface tension is measured by a Wilhelmy method using a generally used surface tension meter (for example, Kyowa Interface Science Co., Ltd., surface tension meter CBVP-Z). The value measured at 60% RH.

<Condition (B) and Condition (C)>
In the present invention, the inclusion liquid preferably contains at least one kind of surfactant. By containing at least one type of surfactant in the encapsulating liquid, it is possible to more reliably form ink dots of a desired size on the recording medium. In this case, at least one of the surfactants contained in the inclusion liquid preferably satisfies the following condition (B).
γs (0) −γs (saturation)> 0 (mN / m) Condition (B)
Furthermore, it is preferable that the surface tension of the inclusion liquid satisfies the following condition (C).
γs <(γs (0) + γs (saturation) ^max ) / 2 ... condition (C)

As described above, γs is the value of the surface tension of the inclusion liquid. Γs (0) is the value of the surface tension of the liquid excluding all surfactants in the composition of the inclusion liquid. γs (saturation) is obtained when one surfactant among the surfactants contained in the inclusion liquid is added to the “liquid excluding all surfactants” and the concentration of the surfactant is increased. The surface tension value of the liquid with the surface tension saturated. γs (saturation) ^max is the maximum value of γs (saturation) obtained for all surfactants satisfying the condition (B) among the surfactants contained in the inclusion liquid.

  The γs (0) can be obtained by measuring the surface tension value of the liquid excluding all the surfactants in the composition of the inclusion liquid. The γs (saturation) is obtained by adding one type of surfactant among the surfactants contained in the inclusion liquid to the “liquid excluding all surfactants” and adjusting the concentration of the surfactant. It is obtained by measuring the surface tension of the liquid when the amount of change in the surface tension with respect to the change in the surfactant concentration becomes 0.01 mN / m or less when it is increased by 0.01% by mass.

The γs (0), γs (saturated), and γs (saturated) ^max will be specifically described below.
For example, as an inclusion liquid, 85.9% of DPGDA (dipropylene glycol diacrylate; manufactured by Daicel Cytec Co., Ltd., a polyfunctional monomer) as the above-described polymerizable compound, and A-DPH (dipentaerythritol hexaacrylate; new) Nakamura Chemical Co., Ltd., polyfunctional monomer)) 3.0%, surfactant BYK-307 (Bic Chemie) 1.0), FIRSTCURE ST-1 (Albemarle) as a polymerization inhibitor 0.1%, DAROCUR TPO (manufactured by Ciba Specialty Chemicals, the following initiator-1) as a photopolymerization initiator, 9.0%, Speedcure DETX (2,4 diethylthioxanthone, manufactured by Lambson) as a sensitizer ) At a rate of 1.0%, γs (0), γ (Saturated), and, gamma] s ^{(saturated) max} becomes as follows.

  That is, γs (0) is the surface tension value of the liquid excluding all the surfactants in the encapsulated liquid, and is 36.7 mN / m. When the surfactant is added to the liquid and the concentration is increased, the saturation value of the surface tension of the liquid is γs (saturated), and the value is 20.2 mN / m.

Here, in this example, since there is one kind of surfactant, γs (saturation) ^max is a value of γs (saturation).
From the above, they are summarized as follows.
γs (0) = 36.7 mN / m
γs (saturation) ^max = 20.2 mN / m

From the above results, the surface tension γs of the inclusion liquid in the above specific example is
γs <(γs (0) + γs (saturation) ^max ) /2=33.6 mN / m
It is preferable to satisfy the relationship.
Here, since the surface tension γs of the inclusion liquid of the above example is 21.4 mN / m, the above relationship is satisfied.
In addition, about the said condition (C), from a viewpoint of preventing the expansion of the ink droplet from landing to exposure more effectively, as surface tension of the inclusion liquid,
γs <γs (0) −3 × {γs (0) −γs (saturated) ^max } / 4
It is more preferable to satisfy the relationship
γs ≦ γs (saturation) ^max
It is particularly preferable to satisfy this relationship.

  The composition of the inclusion liquid may be selected so as to obtain a desired surface tension, but these liquids preferably contain a surfactant. As described above, in order to form ink dots of a desired size on the recording medium (that is, on the liquid film), it is preferable that the inclusion liquid contains at least one surfactant. The surfactant will be described below.

(Surfactant)
In the present invention, as the surfactant, hexane, cyclohexane, p-xylene, toluene, ethyl acetate, methyl ethyl ketone, butyl carbitol, cyclohexanone, triethylene glycol monobutyl ether, 1,2-hexanediol, propylene glycol monomethyl ether, isopropanol , Methanol, water, isobornyl acrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, a substance having strong surface activity against at least one solvent, preferably hexane, toluene, propylene glycol monomethyl ether , Isobornyl acrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate More preferably, it has a strong surface activity against at least one solvent among propylene glycol monomethyl ether, isobornyl acrylate, 1,6-hexanediol diacrylate, and polyethylene glycol diacrylate. It is preferable to use a substance having a strong surface activity with respect to at least one solvent among the substances having, particularly preferably isobornyl acrylate, 1,6-hexanediol diacrylate, and polyethylene glycol diacrylate.

Whether or not a certain compound has a strong surface activity with respect to the solvents listed above can be determined by the following procedure.
(procedure)
One solvent is selected from the solvents listed above, and the surface tension γ _solvent (0) of the _solvent is measured. The compound is added to the same solution as the solvent for obtaining the γ _solvent (0), the concentration of the compound is increased by 0.01% by mass, and the change in the surface tension with respect to the change in the compound concentration is 0.01 mN / m. Measure the surface tension γ _solvent (saturation) of the solution when: The relationship between the γ _solvent (0) and the γ _solvent (saturated) is
γ _solvent (0) −γ _solvent (saturated)> 1 (mN / m)
If so, it can be determined that the compound is a substance having a strong surface activity with respect to the solvent.

  Specific examples of the surfactant contained in the inclusion liquid include anionic surfactants such as dialkylsulfosuccinates, alkylnaphthalenesulfonates, fatty acid salts, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, Nonionic surfactants such as acetylene glycols and polyoxyethylene / polyoxypropylene block copolymers, cationic surfactants such as alkylamine salts and quaternary ammonium salts, and fluorosurfactants. In addition, examples of the surfactant include those described in JP-A Nos. 62-173463 and 62-183457.

  Hereinafter, a liquid (that is, an inclusion liquid) to be filled in microcapsules that can be suitably used in the present invention will be described in detail.

  The inclusion liquid is an active energy ray-curable liquid, and preferably a liquid containing a radical polymerizable composition. That is, the inclusion liquid preferably includes, for example, at least one radical polymerizable composition, and further includes a polymerization initiator, a lipophilic solvent, a colorant, and other components as necessary. In addition, it is preferable that an inclusion liquid is either the structure which does not contain a coloring agent or the content of a coloring agent is less than 1 mass%, or the structure in which an inclusion liquid contains a white pigment as a coloring agent.

In the present invention, the radical polymerizable composition is a composition containing at least one radical polymerizable compound and at least one radical polymerization initiator. When the inclusion liquid contains the radically polymerizable composition, the curing reaction of the inclusion liquid can be performed with high sensitivity in a short time.
Moreover, it is preferable that a polymerization initiator can start a polymerization reaction or a crosslinking reaction with an active energy ray. Thereby, the liquid film formed on a base | substrate with an inclusion liquid can be hardened by irradiation of an active energy ray.
Hereinafter, each component which comprises an inclusion liquid is explained in full detail.

(Radically polymerizable compound)
The radically polymerizable compound has a function of causing radical polymerization by an initiating species such as a radical generated from a polymerization initiator described later and curing a composition containing these.

As the radically polymerizable compound in the present invention, various known radically polymerizable monomers that cause a polymerization reaction with an initiation species generated from a radical initiator are used.
Examples of the radical polymerizable monomer include (meth) acrylates, (meth) acrylamides, aromatic vinyls, vinyl ethers, and compounds having an internal double bond (such as maleic acid). Here, “(meth) acrylate” refers to both and / or “acrylate” and “methacrylate”, and “(meth) acryl” refers to both and / or “acryl” and “methacryl”.

Examples of (meth) acrylates include the following.
Specific examples of monofunctional (meth) acrylates include hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, tert-octyl (meth) acrylate, isoamyl (meth) acrylate, decyl (meth) acrylate, isodecyl ( (Meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, cyclohexyl (meth) acrylate, 4-n-butylcyclohexyl (meth) acrylate, bornyl (meth) acrylate, isobornyl (meth) acrylate, benzyl (meth) Acrylate, 2-ethylhexyl diglycol (meth) acrylate, butoxyethyl (meth) acrylate, 2-chloroethyl (meth) acrylate, 4-bromobutyl (meth) acrylate, shear Ethyl (meth) acrylate, benzyl (meth) acrylate, butoxymethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, alkoxymethyl (meth) acrylate, alkoxyethyl (meth) acrylate, 2- (2-methoxyethoxy) ethyl (Meth) acrylate, 2- (2-butoxyethoxy) ethyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 1H, 1H, 2H, 2H-perfluorodecyl (meth) acrylate, 4 -Butylphenyl (meth) acrylate, phenyl (meth) acrylate, 2,4,5-tetramethylphenyl (meth) acrylate, 4-chlorophenyl (meth) acrylate, phenoxymethyl (meth) acrylate, phenoxyethyl (meth) Acrylate, glycidyl (meth) acrylate, glycidyloxybutyl (meth) acrylate, glycidyloxyethyl (meth) acrylate, glycidyloxypropyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, hydroxyalkyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate,

2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, Diethylaminopropyl (meth) acrylate, trimethoxysilylpropyl (meth) acrylate, trimethylsilylpropyl (meth) acrylate, polyethylene oxide monomethyl ether (meth) acrylate, oligoethylene oxide monomethyl ether (meth) acrylate, polyethylene oxide (meth) acrylate, oligoethylene oxide (Meth) acrylate, oligoethylene oxide monoalkyl ether (meth) acrylate, Reethylene oxide monoalkyl ether (meth) acrylate, dipropylene glycol (meth) acrylate, polypropylene oxide monoalkyl ether (meth) acrylate, oligopropylene oxide monoalkyl ether (meth) acrylate, 2-methacryloyloxytyl succinic acid, 2- Methacryloyloxyhexahydrophthalic acid, 2-methacryloyloxyethyl-2-hydroxypropyl phthalate, butoxydiethylene glycol (meth) acrylate, trifluoroethyl (meth) acrylate, perfluorooctylethyl (meth) acrylate, 2-hydroxy-3 -Phenoxypropyl (meth) acrylate, EO modified phenol (meth) acrylate, EO modified cresol (meth) acrylate, EO modified noni Phenol (meth) acrylate, PO-modified nonylphenol (meth) acrylate, EO-modified 2-ethylhexyl (meth) acrylate and the like.

  Specific examples of the bifunctional (meth) acrylate include 1,6-hexanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 2,4- Dimethyl-1,5-pentanediol di (meth) acrylate, butylethylpropanediol (meth) acrylate, ethoxylated cyclohexanemethanol di (meth) acrylate, polyethylene glycol di (meth) acrylate, oligoethylene glycol di (meth) acrylate , Ethylene glycol di (meth) acrylate, 2-ethyl-2-butyl-butanediol di (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, EO-modified bisphenol A di (meth) acrylate Bisphenol F polyethoxydi (meth) acrylate, polypropylene glycol di (meth) acrylate, oligopropylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 2-ethyl-2-butylpropanediol di (Meth) acrylate, 1,9-nonane di (meth) acrylate, propoxylated ethoxylated bisphenol A di (meth) acrylate, tricyclodecane di (meth) acrylate and the like.

  Specific examples of trifunctional (meth) acrylates include trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, trimethylolpropane alkylene oxide modified tri (meth) acrylate, pentaerythritol tri (meth) Acrylate, dipentaerythritol tri (meth) acrylate, trimethylolpropane tris ((meth) acryloyloxypropyl) ether, isocyanuric acid alkylene oxide modified tri (meth) acrylate, dipentaerythritol tri (meth) acrylate propionate, tris (( (Meth) acryloyloxyethyl) isocyanurate, hydroxypivalaldehyde-modified dimethylolpropane tri (meth) acrylate, sorbitol tri (meta) Acrylate, propoxylated trimethylolpropane tri (meth) acrylate, and the like ethoxylated glycerol triacrylate.

  Specific examples of tetrafunctional (meth) acrylates include pentaerythritol tetra (meth) acrylate, sorbitol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate propionate, ethoxylation Examples include pentaerythritol tetra (meth) acrylate.

  Specific examples of the pentafunctional (meth) acrylate include sorbitol penta (meth) acrylate and dipentaerythritol penta (meth) acrylate.

  Specific examples of hexafunctional (meth) acrylates include dipentaerythritol hexa (meth) acrylate, sorbitol hexa (meth) acrylate, phosphazene alkylene oxide modified hexa (meth) acrylate, captolactone modified dipentaerythritol hexa (meth) An acrylate etc. are mentioned.

  Examples of (meth) acrylamides include (meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-propyl (meth) acrylamide, and Nn-butyl (meth) acrylamide. N-t-butyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-methylol (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N- Examples include diethyl (meth) acrylamide, (meth) acryloylmorpholine, and the like.

  Specific examples of aromatic vinyls include styrene, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, isopropyl styrene, chloromethyl styrene, methoxy styrene, acetoxy styrene, chloro styrene, dichloro styrene, bromo styrene, vinyl benzoic acid. Methyl ester, 3-methylstyrene, 4-methylstyrene, 3-ethylstyrene, 4-ethylstyrene, 3-propylstyrene, 4-propylstyrene, 3-butylstyrene, 4-butylstyrene, 3-hexylstyrene, 4- Hexyl styrene, 3-octyl styrene, 4-octyl styrene, 3- (2-ethylhexyl) styrene, 4- (2-ethylhexyl) styrene, allyl styrene, isopropenyl styrene, butenyl styrene, octenyl Styrene, 4-t-butoxycarbonyl styrene, 4-methoxystyrene, and a 4-t-butoxystyrene.

  Specific examples of vinyl ethers include, as examples of monofunctional vinyl ethers, methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, n-butyl vinyl ether, t-butyl vinyl ether, 2-ethylhexyl vinyl ether, n-nonyl vinyl ether, lauryl vinyl ether, cyclohexyl vinyl ether, Cyclohexylmethyl vinyl ether, 4-methylcyclohexyl methyl vinyl ether, benzyl vinyl ether, dicyclopentenyl vinyl ether, 2-dicyclopentenoxyethyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, butoxyethyl vinyl ether, methoxyethoxyethyl vinyl ether, ethoxyethoxyethyl vinyl ether , Methoxypolye Lenglycol vinyl ether, tetrahydrofurfuryl vinyl ether, 2-hydroxyethyl vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 4-hydroxymethylcyclohexyl methyl vinyl ether, diethylene glycol monovinyl ether, polyethylene glycol vinyl ether, chloroethyl vinyl ether, chlorobutyl vinyl ether Chloroethoxyethyl vinyl ether, phenylethyl vinyl ether, phenoxypolyethylene glycol vinyl ether, and the like.

Examples of polyfunctional vinyl ethers include ethylene glycol divinyl ether, diethylene glycol divinyl ether, polyethylene glycol divinyl ether, propylene glycol divinyl ether, butylene glycol divinyl ether, hexanediol divinyl ether, bisphenol A alkylene oxide divinyl ether, bisphenol F alkylene oxide. Divinyl ethers such as divinyl ether; trimethylolethane trivinyl ether, trimethylolpropane trivinyl ether, ditrimethylolpropane tetravinyl ether, glycerin trivinyl ether, pentaerythritol tetravinyl ether, dipentaerythritol pentavinyl ether, dipentaerythritol hexa Nyl ether, ethylene oxide-added trimethylolpropane trivinyl ether, propylene oxide-added trimethylolpropane trivinyl ether, ethylene oxide-added ditrimethylolpropane tetravinyl ether, propylene oxide-added ditrimethylolpropane tetravinyl ether, ethylene oxide-added pentaerythritol tetravinyl ether, propylene oxide-added pentane And polyfunctional vinyl ethers such as erythritol tetravinyl ether, ethylene oxide-added dipentaerythritol hexavinyl ether, and propylene oxide-added dipentaerythritol hexavinyl ether.
The vinyl ether compound is preferably a di- or trivinyl ether compound from the viewpoints of curability, adhesion to a recording medium, surface hardness of the formed image, and the like, and more preferably a divinyl ether compound. .

  In addition to the above, the radical polymerizable monomer further includes vinyl esters [vinyl acetate, vinyl propionate, vinyl versatate, etc.], allyl esters [allyl acetate, etc.], halogen-containing monomers [vinylidene chloride, Vinyl chloride etc.], vinyl cyanide [(meth) acrylonitrile etc.], olefins [ethylene, propylene etc.] and the like.

  Among the above, as the radical polymerizable monomer, it is preferable to use (meth) acrylates and (meth) acrylamides from the viewpoint of curing speed, and particularly from the viewpoint of curing speed, tetrafunctional or higher functional (meth) acrylate is preferably used. It is preferable to use it. Furthermore, from the viewpoint of the viscosity of the ink composition, it is preferable to use a polyfunctional (meth) acrylate in combination with a monofunctional or bifunctional (meth) acrylate or (meth) acrylamide.

The content of the polymerizable or crosslinkable material in the inclusion liquid is preferably in the range of 50 to 99.6% by mass with respect to the total solid content (mass) of each droplet, and is preferably 70 to 99.0. It is more preferable to set it as the range of the mass%, and it is further more preferable to set it as the range of 80-99.0 mass%.
Moreover, as content in a droplet, it is preferable to set it as the range of 20-98 mass% with respect to the total mass of each droplet, The range of 40-95 mass% is more preferable, 50-90 mass% It is particularly preferable to set the range.

(Polymerization initiator)
The inclusion liquid preferably contains at least one polymerization initiator. This polymerization initiator generates radicals and other starting species by applying actinic light, heat, or both, and initiates, accelerates and cures the polymerization or crosslinking reaction of the polymerizable or crosslinkable material described above. A compound.

In the polymerizable embodiment, it preferably contains a polymerization initiator that causes radical polymerization, and more preferably a photopolymerization initiator.
A photopolymerization initiator is a compound that generates a chemical change by the action of light and interaction with the electronically excited state of a sensitizing dye to generate at least one of a radical, an acid, and a base. From the viewpoint that polymerization can be initiated by such simple means, a photo radical generator is preferred.

  As the photopolymerization initiator in the present invention, irradiated actinic rays, for example, ultraviolet rays of 400 to 200 nm, deep ultraviolet rays, g rays, h rays, i rays, KrF excimer laser rays, ArF excimer laser rays, electron rays, X Those having sensitivity to a beam, molecular beam, ion beam, or the like can be appropriately selected and used.

  Specific photopolymerization initiators known among those skilled in the art can be used without limitation. For example, Bruce M. et al. Monroe et al., Chemical Review, 93, 435 (1993). R. S. By Davidson, Journal of Photochemistry and biologic A: Chemistry, 73.81 (1993). J. P. Faussier “Photoinitiated Polymerization—Theory and Applications”: Rapra Review vol. 9, Report, Rapra Technology (1998). M. Tsunooka et al. , Prog. Polym. Sci. , 21, 1 (1996). Many are described. Further, F.I. D. Saeva, Topics in Current Chemistry, 156, 59 (1990). G. G. Maslak, Topics in Current Chemistry, 168, 1 (1993). H., et al. B. Shuster et al, JACS, 112, 6329 (1990). I. D. F. Eaton et al, JACS, 102, 3298 (1980). A compound group that undergoes oxidative or reductive bond cleavage through interaction with the electronically excited state of the sensitizing dye described in the above can also be used.

  Preferred photopolymerization initiators include (a) aromatic ketones, (b) aromatic onium salt compounds, (c) organic peroxides, (d) hexaarylbiimidazole compounds, (e) ketoxime ester compounds, (F) borate compounds, (g) azinium compounds, (h) metallocene compounds, (i) active ester compounds, (j) compounds having a carbon halogen bond, and the like.

  Preferable examples of the (a) aromatic ketones include “RADIATION CURING IN POLYMER SCIENCE AND TECHNOLOGY” P. FOUASSIER J.M. F. Examples include compounds having a benzophenone skeleton or a thioxanthone skeleton described in RABEK (1993), p77-117. More preferable examples of (a) aromatic ketones include α-thiobenzophenone compounds described in JP-B-47-6416, benzoin ether compounds described in JP-B-47-3981, and JP-B-47-22326. Α-substituted benzoin compounds, benzoin derivatives described in JP-B-47-23664, aroylphosphonic acid esters described in JP-A-57-30704, dialkoxybenzophenones described in JP-B-60-26483, Benzoin ethers described in JP-A-60-26403, JP-A-62-81345, JP-B-1-34242, US Pat. No. 4,318,791, and α-aminobenzophenones described in European Patent 0284561A1, P-di (dimethyla) described in JP-A-2-211452 Nobenzoyl) benzene, thio-substituted aromatic ketone described in JP-A-61-194062, acylphosphine sulfide described in JP-B-2-9597, acylphosphine described in JP-B-2-9596, JP-B-63- Examples thereof include thioxanthones described in Japanese Patent No. 61950, and coumarins described in Japanese Patent Publication No. 59-42864.

  Here, as the (b) aromatic onium salt compound, elements of Group V, VI and VII of the periodic table, specifically N, P, As, Sb, Bi, O, S, Se, Te, Or an aromatic onium salt of I. For example, iodonium salts described in European Patent No. 104143, US Pat. No. 4,837,124, Japanese Patent Laid-Open No. 2-150848, Japanese Patent Laid-Open No. 2-96514, European Patent Nos. 370693, 233567, and 297443 are disclosed. , 294442, 279210, and 422570, U.S. Pat. Nos. 3,902,144, 4,933,377, 4,760013, 4,734,344, and 2,833,827, sulfonium salts and diazonium salts (Such as benzenediazonium which may have a substituent), diazonium salt resins (formaldehyde resin of diazodiphenylamine, etc.), N-alkoxypyridinium salts, etc. (for example, US Pat. No. 4,743,528, JP 63-138345 JP-A-63-142345, JP-A-63-142346, and JP-B-46-42363, specifically 1-methoxy-4-phenylpyridinium tetrafluoroborate, etc. In addition, compounds described in JP-B Nos. 52-147277, 52-14278, and 52-14279 can be preferably used. Generates radicals and acids as active species.

  Further, (c) “organic peroxide” includes almost all organic compounds having one or more oxygen-oxygen bonds in the molecule. For example, 3,3 ′, 4,4′-tetrakis ( t-butylperoxycarbonyl) benzophenone, 3,3′4,4′-tetrakis (t-amylperoxycarbonyl) benzophenone, 3,3′4,4′-tetrakis (t-hexylperoxycarbonyl) benzophenone, 3 , 3'4,4'-tetrakis (t-octylperoxycarbonyl) benzophenone, 3,3'4,4'-tetrakis (cumylperoxycarbonyl) benzophenone, 3,3'4,4'-tetrakis (p- Peroxyesters such as isopropylcumylperoxycarbonyl) benzophenone and di-t-butyldiperoxyisophthalate It is preferably used.

  Examples of (d) hexaarylbiimidazole include lophine dimers described in JP-B Nos. 45-37377 and 44-86516, such as 2,2′-bis (o-chlorophenyl) -4,4 ′. , 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-bromophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o, p- Dichlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-chlorophenyl) -4,4 ′, 5,5′-tetrakis (m-methoxyphenyl) biimidazole, 2,2′-bis (o, o′-dichlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-nitrophenyl) -4,4 ′, 5 '-Tetraphenylbiimidazole, 2,2'-bis (o-methylphenyl) -4,4', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-trifluorophenyl) -4 , 4 ′, 5,5′-tetraphenylbiimidazole and the like.

  Examples of the (e) ketoxime ester include 3-benzoyloxyiminobutane-2-one, 3-acetoxyiminobutan-2-one, 3-propionyloxyiminobutan-2-one, and 2-acetoxyimino. Pentan-3-one, 2-acetoxyimino-1-phenylpropan-1-one, 2-benzoyloxyimino-1-phenylpropan-1-one, 3-p-toluenesulfonyloxyiminobutan-2-one, And 2-ethoxycarbonyloxyimino-1-phenylpropan-1-one.

Examples of the (f) borate compound include compounds described in US Pat. Nos. 3,567,453 and 4,343,891, European Patents 109,772 and 109,773. .
Examples of (g) azinium salt compounds include JP-A 63-138345, JP-A 63-142345, JP-A 63-142346, JP-A 63-143537, and JP-B 46-. The compound group which has NO bond as described in each gazette of 42363 is raised.

  Examples of (h) metallocene compounds include JP-A-59-152396, JP-A-61-151197, JP-A-63-41484, JP-A-2-249, and JP-A-2-4705. Examples thereof include titanocene compounds described in the publication, and iron-arene complexes described in JP-A-1-304453 and JP-A-1-152109.

  Specific examples of the titanocene compound include di-cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, and di-cyclopentadienyl-Ti-bis-2,3,4. , 5,6-pentafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-cyclopentadienyl-Ti-bis -2,4,6-trifluorophen-1-yl, di-cyclopentadienyl-Ti-2,6-difluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,4- Difluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis 2,3,5,6-tetrafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,4-difluorophen-1-yl, bis (cyclopentadienyl) -bis (2 , 6-Difluoro-3- (pyridin-1-yl) phenyl) titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (methylsulfonamido) phenyl] titanium, bis (cyclopentadienyl) ) Bis [2,6-difluoro-3- (N-butylbialoyl-amino) phenyl] titanium and the like.

  Examples of (i) active ester compounds include European Patent Nos. 0290750, 046083, 156153, 271851, and 0388343, U.S. Pat. Nos. 3,901,710, and 4,181,531. Nitrobenzyl ester compounds described in JP-A-60-198538 and JP-A-53-133022, European Patent Nos. 099672, 84515, 199672, 0441115, and 0101122, respectively. Specifications, U.S. Pat. Nos. 4,618,564, 4,371,605, and 4,431,774, JP-A 64-18143, JP-A-2-245756, and JP-A-4-365048, respectively. JP-B 62-6223, JP-B 63-14 No. 40, and compounds, and the like described in the JP-A-59-174831.

  Moreover, (j) As a preferable example of the compound which has a carbon halogen bond, Wakabayashi et al., Bull. Chem. Soc. Examples include compounds described in Japan, 42, 2924 (1969), compounds described in British Patent 1388492, compounds described in JP-A-53-133428, compounds described in German Patent 3333724, and the like.

  F.F. C. J. Schaefer et al. Org. Chem. 29, 1527 (1964), compounds described in JP-A-62-258241, compounds described in JP-A-5-281728, and the like. Further, a compound as described in German Patent No. 2641100, a compound described in German Patent No. 3333450, a compound group described in German Patent No. 3021590, or a compound group described in German Patent No. 3021599 , Etc.

  As a photoinitiator in this invention, although the compound illustrated below can be mentioned, for example, It is not limited to these.

  In addition, as a polymerization initiator, what is excellent in a sensitivity is preferable, but it is preferable to use the polymerization initiator which does not raise | generate thermal decomposition at the temperature to 80 degreeC from a viewpoint of storage stability.

  A polymerization initiator can be used 1 type or in combination of 2 or more types. Moreover, a well-known sensitizer can also be used together for the purpose of a sensitivity improvement in the range which does not impair the effect of this invention.

  The content of the polymerization initiator in the encapsulating liquid should be within the range of 0.5 to 20% by mass with respect to the polymerizable material in the encapsulating liquid, from the viewpoint of stability over time, curability and curing rate. Is preferable, it is more preferable to set it as 1-15 mass%, and it is especially preferable to set it as 3-10 mass%. By setting the content within the above range, it is possible to suppress the occurrence of precipitation or separation over time, or the deterioration of performance such as the strength and rubbing resistance of the ink after curing.

(Sensitizing dye)
Moreover, it is preferable to add a sensitizing dye to the inclusion liquid for the purpose of improving the sensitivity of the photopolymerization initiator. Examples of preferred sensitizing dyes include those belonging to the following compounds and having an absorption wavelength in the 350 nm to 450 nm region.

  Specifically, polynuclear aromatics (eg, pyrene, perylene, triphenylene), xanthenes (eg, fluorescein, eosin, erythrosine, rhodamine B, rose bengal), cyanines (eg, thiacarbocyanine, oxacarbocyanine) ), Merocyanines (eg merocyanine, carbomerocyanine), thiazines (eg thionine, methylene blue, toluidine blue), acridines (eg acridine orange, chloroflavin, acriflavine), anthraquinones (eg anthraquinone), squalium (For example, squalium) and coumarins (for example, 7-diethylamino-4-methylcoumarin).

  Examples of more preferable sensitizing dyes include compounds represented by the following general formulas (IX) to (XIII).

In the formula (IX), A ¹ represents a sulfur atom or —NR ⁵⁰ —, R ⁵⁰ represents an alkyl group or an aryl group, and L ² represents a basic nucleus of the dye in combination with the adjacent A ¹ and the adjacent carbon atom. R ⁵¹ and R ⁵² each independently represents a hydrogen atom or a monovalent nonmetallic atomic group, and R ⁵¹ and R ⁵² are bonded to each other to form an acidic nucleus of the dye. May be. W represents an oxygen atom or a sulfur atom.
In formula (X), Ar ¹ and Ar ² each independently represent an aryl group and are linked via a bond with —L ³ —. Here, L ³ represents —O— or —S—. W is synonymous with that shown in the general formula (IX).
In the formula (XI), A ² represents a sulfur atom or —NR ⁵⁹ —, L ⁴ represents a nonmetallic atomic group that forms a basic nucleus of the dye together with the adjacent A ² and carbon atom, and R ⁵³ , R ⁵⁴ , R ⁵⁵ , R ⁵⁶ , R ⁵⁷ and R ⁵⁸ each independently represents a monovalent non-metallic atomic group, and R ⁵⁹ represents an alkyl group or an aryl group.

In formula (XII), A ³ and A ⁴ each independently represent —S— or —NR ⁶² — or —NR ⁶³ —, wherein R ⁶² and R ⁶³ each independently represent a substituted or unsubstituted alkyl group, substituted Or an unsubstituted aryl group, and L ⁵ and L ⁶ each independently represent a nonmetallic atomic group that forms a basic nucleus of a dye together with adjacent A ³ , A ⁴ and an adjacent carbon atom; ⁶⁰ and R ⁶¹ are each independently a hydrogen atom or a monovalent non-metallic atomic group, or may be bonded to each other to form an aliphatic or aromatic ring.
In formula (XIII), R ⁶⁶ represents an aromatic ring or a hetero ring which may have a substituent, and A ⁵ represents an oxygen atom, a sulfur atom or —NR ⁶⁷ —. R ⁶⁴ , R ⁶⁵ and R ⁶⁷ each independently represent a hydrogen atom or a monovalent non-metallic atomic group, R ⁶⁷ and R ⁶⁴ , and R ⁶⁵ and R ⁶⁷ each represent an aliphatic or aromatic ring. Can be combined to form.

  Specific examples of the compounds represented by the general formulas (IX) to (XIII) include the exemplified compounds (A-1) to (A-20) shown below.

(Co-sensitizer)
Furthermore, it is preferable to add a known compound having a function of further improving the sensitivity or suppressing polymerization inhibition by oxygen as a co-sensitizer to the inclusion liquid.
Examples of co-sensitizers include amines such as M.I. R. Sander et al., “Journal of Polymer Society”, Vol. 10, 3173 (1972), Japanese Patent Publication No. 44-20189, Japanese Patent Publication No. 51-82102, Japanese Patent Publication No. 52-134692, Japanese Patent Publication No. 59-138205. , JP-A-60-84305, JP-A-62-18537, JP-A-64-33104, Research Disclosure 33825, and the like. Specific examples include triethanolamine. P-dimethylaminobenzoic acid ethyl ester, p-formyldimethylaniline, p-methylthiodimethylaniline and the like.

Other examples include thiols and sulfides, for example, thiol compounds described in JP-A-53-702, JP-B-55-500806, JP-A-5-142772, and JP-A-56-75643. Specific examples include 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, 2-mercapto-4- (3H) -quinazoline, β-mercaptonaphthalene, and the like. It is done.
Other examples include amino acid compounds (eg, N-phenylglycine), organometallic compounds described in Japanese Patent Publication No. 48-42965 (eg, tributyltin acetate), and hydrogen described in Japanese Patent Publication No. 55-34414. Donors, sulfur compounds described in JP-A-6-308727 (eg, trithiane), phosphorus compounds described in JP-A-6-250387 (diethylphosphite, etc.), Si-- described in JP-A-8-65779 H, Ge-H compound, etc. are mentioned.

  Moreover, when making an inclusion liquid contain a white pigment as a coloring agent, it is preferable to make content of the coloring agent in an inclusion liquid into 2-45 mass%, and it is more preferable to set it as 4-35 mass%.

(Other ingredients)
Moreover, a well-known additive etc. can be used together for an inclusion liquid according to the objective besides the above-mentioned component.

<Storage stabilizer>
It is preferable to add a storage stabilizer to the inclusion liquid for the purpose of suppressing undesired polymerization during storage. The storage stabilizer is preferably used in combination with a polymerizable or crosslinkable material, and it is preferable to use a storage stabilizer that is soluble in the contained droplets or liquid or other coexisting components.

  Storage stabilizers include quaternary ammonium salts, hydroxylamines, cyclic amides, nitriles, substituted ureas, heterocyclic compounds, organic acids, hydroquinones, hydroquinone monoethers, organic phosphines, copper compounds, and the like. Specific examples include benzyltrimethylammonium chloride, diethylhydroxylamine, benzothiazole, 4-amino-2,2,6,6-tetramethylpiperidine, citric acid, hydroquinone monomethyl ether, hydroquinone monobutyl ether, and copper naphthenate. It is done.

  The amount of storage stabilizer added is preferably adjusted as appropriate based on the activity of the polymerization initiator, the polymerizability of the polymerisable or crosslinkable material, and the type of storage stabilizer, but the balance of storage stability and curability is balanced. In terms of solids content in the liquid, it is preferably 0.005 to 1% by mass, more preferably 0.01 to 0.5% by mass, and 0.01 to 0.2% by mass. More preferably.

<Conductive salts>
Conductive salts are solid compounds that improve conductivity. In the present invention, it is preferable not to use it substantially because there is a great concern of precipitation during storage, but it is possible to increase the solubility of conductive salts or use a highly soluble liquid component. If it is good, an appropriate amount may be added.
Examples of the conductive salts include potassium thiocyanate, lithium nitrate, ammonium thiocyanate, dimethylamine hydrochloride and the like.

<solvent>
In the present invention, a known solvent can be used as necessary. The solvent can be used for the purpose of adjusting the polarity, viscosity, surface tension, conductivity, and printing performance of the inclusion liquid.
Since the solvent is a water-insoluble liquid and does not contain an aqueous solvent, it is preferable in terms of recording a high-quality image with quick drying and uniform line width. It is desirable to do.
As the high-boiling organic solvent, those having a property excellent in compatibility with the constituent materials, particularly with the monomers are preferable.
Specifically, tripropylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, ethylene glycol monobenzyl ether, diethylene glycol monobenzyl ether should be used. Is preferred.

  Known solvents include low boiling point organic solvents that are organic solvents at 100 ° C. or lower, but there is a concern of affecting the curability, and it is desirable not to use low boiling point organic solvents in consideration of environmental pollution. . When used, it is preferable to use a highly safe solvent, and a highly safe solvent is a solvent having a high management concentration (an index indicated by the work environment evaluation criteria), preferably 100 ppm or more, More preferably, it is 200 ppm or more. Specific examples include alcohols, ketones, esters, ethers, hydrocarbons, and the like, and specific examples include methanol, 2-butanol, acetone, methyl ethyl ketone, ethyl acetate, and tetrahydrofuran.

  Solvents can be used in combination other than one type alone, but when water and / or a low boiling point organic solvent is used, the amount of both used should be 0 to 20% by mass in each liquid. It is more preferable to set it as 0-10 mass%, and it is especially preferable not to contain substantially. The inclusion liquid according to the present invention does not substantially contain water, thereby improving the stability over time such as non-uniformity over time, turbidity of liquid due to dye precipitation, etc. The drying property when using a recording medium with high properties can also be increased. In addition, it does not contain substantially means accepting presence of an inevitable impurity.

<Other additives>
Furthermore, known additives such as polymers, surface tension adjusters, ultraviolet absorbers, antioxidants, anti-fading agents and pH adjusters can be used in combination.
Regarding the surface tension adjusting agent, ultraviolet absorber, antioxidant, anti-fading agent, and pH adjusting agent, known compounds may be appropriately selected and used. For example, JP-A-2001-181549 discloses a specific example. The additives described can be used.

Next, the ink jet recording apparatus according to the second aspect of the present invention for recording an image on the recording medium according to the first aspect of the present invention to produce a printed matter will be described in detail.
FIG. 5 is a front view showing a schematic configuration of an example of the ink jet recording apparatus of the present invention, and FIG. 6 is a top view showing the recording head unit 46 and the ultraviolet irradiation unit 52 of the ink jet recording apparatus 10 shown in FIG. is there.
In each of the following embodiments, ultraviolet rays among actinic ray curable inks (hereinafter also referred to as “active energy ray curable inks”) that are cured by irradiation with actinic rays (hereinafter also referred to as “active energy rays”). Although an actinic radiation curable ink jet recording apparatus using a curable ink will be described as an example, the present invention is not limited to this, and can be applied to an ink jet recording apparatus using various actinic radiation curable inks.

As shown in FIG. 5, the inkjet recording apparatus 10 includes a transport unit 12 that transports a recording medium P, a capsule rupture unit 13 that bursts microcapsules of the recording medium P, and a recording target transported by the transport unit 12. A support unit 15 disposed facing the conveyance path of the medium P, an image recording unit 16 supported by the support unit 15 for recording an image on the recording medium P, and a recording medium P supported by the support unit 15 An image fixing unit 18 for fixing the image recorded thereon, a curing accelerating unit 19 for heating the recording medium P on which the image is recorded, and a control unit 20 for controlling ejection of ink droplets in the image recording unit 16 Have
An input device 22 is connected to the control unit 20 of the ink jet recording apparatus 10. As the input device 22, various devices that transmit image data such as an image reading device such as a scanner and an image processing device such as a personal computer can be used. Moreover, the connection method of the input device 22 and the control part 20 can use various connection methods regardless of a wire and a radio | wireless.

The transport unit 12 includes a supply roll 30, a transport roll pair 34, and a collection roll 36, and supplies, transports, and collects the recording medium P.
The supply roll 30 has a continuous paper-like recording medium P wound in a roll shape, and supplies the recording medium P. Note that the recording medium P has a configuration in which the capsule layer 6 containing the microcapsules 4 is applied (or formed) on the surface of the substrate 2 as described above. Here, in the present embodiment, a capsule that bursts when a predetermined pressure is applied is used as the microcapsule 4 of the recording medium P.
The transport roll pair 34 is a pair of rolls, and is disposed on the downstream side of the supply roll 30 in the transport path of the recording medium P, and sandwiches the recording medium P supplied from the supply roll to downstream in the transport direction. To the side.
The collection roll 36 is disposed on the most downstream side of the conveyance path of the recording medium P. The collection roll 36 is supplied from the supply roll 30 and further conveyed by a pair of conveyance rolls 34 and passes through a position facing a capsule breaking section 13, an image recording section 16, an image fixing section 18, and a curing accelerating section 19 described later. The recording medium P is wound up.
Here, the conveyance roll pair 34 and the collection roll 36 are connected to a drive unit (not shown) and are rotated by the drive unit.

  Here, the supply roll 30, the conveyance roll pair 34, and the collection | recovery roll 36 are arrange | positioned at linear form. Thereby, after the recording medium P is pulled out from the supply roll 30, the recording medium P is moved in one direction, in the present embodiment, in the horizontal direction with the surface on which the image is recorded facing upward.

The capsule breaking unit 13 is disposed on the downstream side of the supply roll 30 in the conveyance direction of the recording medium P.
The capsule breaking unit 13 has a pressure roll pair 60.
The pressure roll pair 60 is disposed at a position where the recording medium P is sandwiched on the downstream side of the supply roller 30 in the conveyance path of the recording medium P. The pressure roll pair 60 is a roll pair longer than the width of the recording medium P.
The pressure roll pair 60 may be a driven roller that is driven in synchronization with the movement of the recording medium P or a drive roller pair that is rotated by driving.
The pressure roll pair 60 sandwiches the recording medium P supplied from the supply roller 30 and applies a predetermined pressure to the recording medium P to rupture the microcapsules 4 on the substrate.
That is, the recording medium P is sandwiched between the pressure roll pair 60 of the capsule breaking portion 13, whereby the microcapsule 4 is ruptured and a liquid film 8 having a predetermined thickness is formed on the surface of the substrate 2. The recording medium P on which the liquid film 8 having a predetermined thickness is formed on the substrate 2 is transported by the transport unit 12 to a position facing the image recording unit 16 and the image fixing unit 18.

Next, the support unit 15, the image recording unit 16, and the image fixing unit 18 will be described.
The support unit 15 includes a main body platen 38 and a head platen 40 and supports the image recording unit 16 and the image fixing unit 18.
The main body surface plate 38 is a plate-like member, and is disposed between the capsule breaking portion 13 and the conveyance roll pair 34 so as to be spaced apart from the recording medium P by a predetermined distance in parallel. In other words, the main body surface plate 38 is disposed at a position facing the surface (hereinafter also referred to as “image recording surface”) on which the image of the recording medium P conveyed by the conveying unit 12 is recorded.
The main body surface plate 38 has openings 38a at positions opposed to recording heads 48W, 48C, 48M, 48Y, and 48K of the image recording unit 16 to be described later, and to ultraviolet irradiation units 54 and 54a of the image fixing unit 18 to be described later. An opening 38b is formed at the opposed position.

The head surface plate 40 has a plate portion 40 a and a foot portion 40 b, is disposed on the opposite side of the main body surface plate 38 from the recording medium P side, and is connected to the main body surface plate 38.
The plate portion 40a is disposed on the opposite side of the main body surface plate 38 from the recording medium P side and spaced apart by a predetermined distance, and holds recording heads 48W, 48C, 48M, 48Y, 48K of the image recording unit 16 described later. Yes. Further, the foot portions 40b are disposed at the four corners of the plate portion 40a and are connected to the main body surface plate 38.

The image recording unit 16 includes a recording head unit 46 and an ink tank 50.
The recording head unit 46 includes recording heads 48W, 48C, 48M, 48Y, and 48K.
The recording heads 48W, 48C, 48M, 48Y, and 48K are arranged in the order of the recording head 48W, the recording head 48C, the recording head 48M, the recording head 48Y, and the recording head 48K from the upstream to the downstream in the conveyance direction of the recording medium P. Has been. The recording heads 48W, 48C, 48M, 48Y, and 48K are held by the head surface plate 40, and the leading ends of the respective ink discharge portions are opposed to the conveyance path of the recording medium P, that is, the conveyance unit 12 is. Is disposed opposite to the recording medium P conveyed on the conveying path (hereinafter also simply referred to as “opposing the recording medium P”).

The recording heads 48W, 48C, 48M, 48Y, and 48K have a large number of ejection openings (nozzles, inks) at regular intervals in the direction orthogonal to the conveyance direction of the recording medium P, that is, in the entire width direction of the recording medium P. This is a full-line type and piezo-type ink jet head in which a discharge unit is disposed, and is connected to a control unit 20 and an ink tank 50 described later. In the recording heads 48W, 48C, 48M, 48Y, and 48K, the control unit 20 controls the ejection amount and ejection timing of the ink droplets.
While the recording medium P is being transported by the transporting unit 12, white (W), cyan (C), magenta (M), yellow (Y), and black (K) from each recording head 48W, 48C, 48M, 48Y, 48K. A color image can be formed on the recording medium P by ejecting the respective color inks toward the recording medium P.

In this embodiment, the recording head is a piezo element (piezoelectric element) type, but is not limited to this, and instead of the piezo type, ink is heated by a heating element such as a heater to generate bubbles, and the pressure is It is also possible to use various types of recording heads such as a thermal jet method for ejecting ink droplets.
The ink ejected from the recording head of this embodiment is an ultraviolet curable ink.

  The ink tank 50 is provided corresponding to the recording heads 48W, 48C, 48M, 48Y, and 48K. Each ink tank 50 stores ink of each color corresponding to the recording head, and supplies the stored ink to the corresponding recording heads 48W, 48C, 48M, 48Y, and 48K.

In addition, a plate-like platen 56 is disposed at a position facing the recording heads 48W, 48C, 48M, 48Y, 48K on the surface side where the image of the recording medium is not formed.
The platen 56 moves the recording medium P conveyed to a position facing each recording head to the surface side where no image is formed, that is, the side opposite to the surface where the recording head unit 46 of the recording medium P is disposed. Support from the surface. Thereby, the distance between the recording medium P and each recording head can be made constant, and a high-quality image can be formed on the recording medium P.
The shape of the platen 56 is not limited to a flat plate, and may be a curved surface convex toward the recording head. In this case, the recording heads 48W, 48C, 48M, 48Y, and 48K are arranged so that the distance from the platen is constant.

  The image fixing unit 18 includes a plurality of ultraviolet irradiation units 52 and a final curing ultraviolet irradiation unit 52a. The image fixing unit 18 irradiates an image formed on the recording medium P by the recording head unit 46 with ultraviolet rays. The ink layer) is semi-cured or cured to fix the image.

  In the present invention, the semi-curing of the ink (that is, the ink liquid) is the same as in the case of the liquid film, and means partially cured (partially cured; partial curing). It is a state where it is cured but not completely cured. In addition, when the ink liquid discharged on the liquid film is semi-cured, the degree of curing may be non-uniform, and the ink liquid is preferably cured in the depth direction. Here, in the present embodiment, the semi-cured ink liquid is ink droplets that land on the liquid film 8 of the recording medium P and form an ink layer.

  When the ink liquid is semi-cured and an ink liquid having a different hue is ejected onto the semi-cured ink liquid, a technical effect favorable to the quality of the obtained printed matter can be obtained. Moreover, the action mechanism can be confirmed by observing the cross section of the printed matter.

Hereinafter, the semi-curing of the ink liquid (that is, the ink droplet landed on the liquid film and the ink layer formed by the landed ink droplet) will be described.
Figure 7 is a schematic cross-sectional view on the semi-cured first ink d _a shown a recording medium where ink droplets have been deposited d _b, FIG. 8 (A) and (B) is in an uncured state, respectively is a schematic sectional view showing an example of a recording medium having ink d _b is deposited as droplets onto the first ink d _a, FIG. 8 (C) hitting the ink on the ink liquid while being fully cured It is a typical sectional view showing an example of a recording medium dropped.
The ink d _a after ejected, when forming a secondary color by ink d _b is deposited as droplets onto the first ink d _a is the ink d _b onto the first ink d _a semi-cured It is preferable to give.
Here, the semi-cured state of the first ink d _a, the same as the semi-cured state of the above-described liquid film, as shown in FIG. 7, when the second ink d _b is deposited as droplets onto the first ink d _a , (1) a portion of the second ink _{d b} emerges at the surface of the first ink _{d a,} (2) a portion of the second ink _{d b} lies within the first ink _{d a,} and (3) ink _{d b} the lower is a condition where there is an ink d _a.
By thus semi-curing the ink, can be suitably superimposed cured film of the ink d _a a (colored film A) and an ink liquid d _b cured film (colored film B), good color reproduction Is possible.

In contrast, when ink d _b is deposited as droplets onto the first ink d _a uncured, or all of the ink d _b as shown in FIG. 8 (A) sinks into ink d _a, and / or in a state where there is no ink d _a is the lower layer of the ink d _b as shown in FIG. 8 (B). In this case, even if high density imparts ink d _b droplets, since the droplets are independent of each other, causing the color saturation of the secondary color to decrease.

Also, if ink d _b is deposited _as droplets completely cured ink on d _a, ink d _b as shown in FIG. 8 (C) does not sink into ink d _a. In this case, droplet ejection interference occurs, a uniform ink liquid film layer cannot be formed, and color reproducibility is reduced.

Here, the droplets are not independent of each other when applying droplets of a high density ink d _b, the viewpoint of forming a uniform film of the second ink d _b, and suppress the occurrence of fired droplet interference from the viewpoint of the amount of the uncured portion of the ink d _a per unit area is preferably less than the maximum droplet amount of the ink d _b applied per unit area, and more preferably substantially smaller. That is, _(also referred to as _M (ink liquid A).) Weight M _da per unit surface area of uncured regions of the first ink d _a layer and the maximum weight of the ink ejected per unit area m _{db (m} (ink liquid B It is preferable that (m _db / 30) <M _da <m _db is satisfied, and that (m _(db / 20) <M _da <(m _db / 3) is further satisfied. It is preferable that (m _db / 10) <M _da <(m _db / 5) is satisfied.
By setting (m _db / 30) <M _da , the occurrence of droplet ejection interference can be prevented, and the dot size reproducibility can be increased. In _addition, by setting M da _{<m db,} can uniformly form a film of the first ink _{d a,} a decrease in density can be prevented.

Here, the weight of the uncured regions of the first ink d _a per unit area, as in the case of the above-described liquid film, is determined by a transfer test. Specifically, after completion of the semi-curing step (e.g. after irradiating with actinic radiation) before deposition of the droplets of the second ink d _b a, a permeable medium such as plain paper in a semi-cured state ink is pressed against the liquid d _a layer, the amount of _the first ink d _a that transfers to the permeable medium is determined by weight measurement. the measured value is defined as the weight of the uncured regions of the first ink.
For example, the maximum amount of the second ink _{d b,} in droplet deposition density of 600 × 600 dpi, is set to 12 picoliters per pixel, the maximum weight _{m db} of the second ink _{d b} ejected per unit surface area, 0.74 mg / cm ² and becomes (assuming the density of the second ink _{d b} is about 1.1g / cm3.). Therefore, in this case, the weight _{M da} uncured portions per unit area of the first ink _{d a} layer is preferably to 0.025 mg / cm ² or more 0.74 mg / cm ² or less, 0.037 mg / cm more preferably to ² or more 0.25 mg / cm ² or less, and particularly preferably 0.074 mg / cm ² or more 0.148 mg / cm ² or less.

  In the present invention, an active energy ray is applied to the liquid film and / or the ink liquid to cause a curing reaction, thereby semi-curing the liquid film and / or the ink liquid. Here, the method of applying an active energy ray to cause a semi-curing reaction is a method of insufficiently carrying out the polymerization reaction of the polymerizable compound on the surface of the liquid film and / or ink liquid formed on the recording medium. . On the surface of the liquid film and / or ink liquid, the polymerization reaction tends to be hindered by the influence of oxygen in the air as compared with the inside. Therefore, the semi-curing reaction of the liquid film and / or the ink liquid can be caused by controlling the application condition of the active energy ray.

The amount of energy required for semi-curing the liquid film and / or ink liquid varies depending on the type and content of the polymerization initiator, but generally 1 to 500 mJ / cm ² when energy is applied by active energy rays. The degree is preferred.

Generation of active species due to decomposition of the polymerization initiator is promoted by applying active energy rays such as actinic light and heating, and curing by polymerization of a polymerizable material resulting from the active species due to increase in active species or temperature rise. The reaction is promoted.
Moreover, thickening (viscosity increase) can also be suitably performed by irradiation of actinic light or heating.

  The plurality of ultraviolet irradiation units 52 are disposed on the surface of the main body platen 38 opposite to the recording medium P, and are respectively downstream of the recording heads 48W, 48C, 48M, and 48Y in the conveyance path of the recording medium P. Is arranged. That is, the plurality of ultraviolet irradiation units 52 are arranged between the recording heads 48W, 48C, 48M, 48Y, and 48K along the conveyance direction of the recording medium P. Further, the final exposure ultraviolet irradiation unit 52a is disposed on the surface of the main body plate 38 opposite to the recording medium P, and is disposed downstream of the recording head 48K in the conveyance path of the recording medium P. . That is, the final exposure ultraviolet irradiation unit 52a is arranged on the downstream side of the recording head arranged on the most downstream side in the conveyance path of the recording medium P.

  That is, each recording head, each ultraviolet irradiation unit 52, and the final exposure ultraviolet irradiation unit 52a are, as shown in FIG. 6, from the upstream side to the downstream side of the transport path, the recording head 48W, the ultraviolet irradiation unit 52, and the recording head. 48C, the ultraviolet irradiation unit 52, the recording head 48M, the ultraviolet irradiation unit 52, the recording head 48Y, the ultraviolet irradiation unit 52, the recording head 48K, and the final curing ultraviolet irradiation unit 52a.

Here, the ultraviolet irradiation unit 52 and the final curing ultraviolet irradiation unit 52a differ only in the size of the apparatus and the target to be irradiated with ultraviolet rays. Specifically, the ultraviolet irradiation unit 52 is formed by each recording head. The ink layer of each color of the printed image (that is, the image formed on each color ink) is semi-cured, and the final exposure ultraviolet unit 52a irradiates light having a stronger intensity than the other ultraviolet irradiation units. The apparatus configuration is the same as that of the ultraviolet irradiation unit 52 except that the image of each ink layer formed on the P liquid film 8 and the recording medium P is reliably cured. This will be described using the unit 52.
Since each ultraviolet irradiation unit 52 has the same configuration, only one ultraviolet irradiation unit 52 will be described below.
The ultraviolet irradiation unit 52 includes two ultraviolet irradiation units 54, and the ultraviolet irradiation units 54 are arranged in series on a straight line in the width direction of the recording medium P. The ultraviolet irradiation unit 52 irradiates the entire area in the width direction of the recording medium P with the two ultraviolet irradiation units 54.

The ultraviolet irradiation unit 54 includes a UV lamp, and is disposed on the surface of the main body surface plate 38 opposite to the recording medium P side so as to face the conveyance path of the recording medium P.
The UV lamp is a light source that emits ultraviolet light, and irradiates the ultraviolet light toward the recording medium P side. As the UV lamp, various ultraviolet light sources such as a metal halide lamp and a high-pressure mercury lamp can be used.
An opening 38b is formed at a position of the main body surface plate 38 facing the UV lamp. Thereby, the ultraviolet rays emitted from the UV lamp pass through the opening 38b and reach the recording medium P.

The curing accelerating unit 19 is disposed at a position facing the final curing ultraviolet irradiation unit 52a with the recording medium P interposed therebetween. In other words, the curing accelerating unit 19 is disposed opposite to the final curing ultraviolet irradiation unit 52a on the side opposite to the surface on which the image of the recording medium P is formed, in other words, on the back side of the recording medium P. ing. The curing accelerating unit 19 is a means for heating the recording medium, and heats the recording medium P at the opposite position and the ink layer formed on the recording medium P.
As the curing accelerator 19, heating means for heating the recording medium in a non-contact manner such as an infrared LED, infrared LD, hot air heater, etc., heating means for heating the recording medium in contact with a panel heater, etc. Various heating means can be used.
Here, in the case of using a heating unit that heats the recording medium while being in contact as the curing accelerator, the curing accelerator may be used as a platen.
In the present embodiment, an example in which the recording medium P and a heating unit that heats the ink layer are used as the curing accelerating portion will be described. However, the present invention is not limited to this, and the liquid film of the recording medium P, In addition, various means for accelerating the curing of the ink layer can be used. For example, a means for reducing the oxygen concentration by sealing nitrogen in a region where the recording medium is exposed in the final curing exposure unit 52a. Can be used.

  The control unit 20 is connected to the recording heads 48W, 48C, 48M, 48Y, and 48K of the recording head unit 46, and uses the image data sent from the input device 22 as a drawing signal, and the recording heads 48W, 48C. , 48M, 48Y and 48K are controlled to form an image on the recording medium P.

Next, the operation of the ink jet recording apparatus 10, that is, the recording operation on the recording medium P will be described to describe the ink jet recording apparatus of the present invention in more detail.
9A to 9C are process diagrams schematically showing a process of forming an image on a recording medium.

  First, the recording medium P delivered from the supply roll 30 is conveyed in a predetermined direction (Y direction in FIG. 5) by the rotation of the conveyance roll pair 34. Here, as described above, the recording medium P of the present embodiment is a continuous paper having a certain length or more, and the recording medium P is conveyed without breaks.

As shown in FIG. 9A, the recording medium P pulled out from the supply roll 30 is sandwiched between the pressure roll pair 60 of the capsule breaking portion 13 and pressurized to a predetermined pressure, so that the microscopic surface on the surface of the substrate 2 is obtained. The capsule 4 is ruptured.
As a result, a liquid film 8 having a predetermined thickness is formed on the surface of the substrate 2 of the recording medium P.

The recording medium P on which the liquid film 8 is formed on the substrate 2 is further transported by the transport roll pair 34 of the transport unit 12 and passes through a position facing the recording head 48W.
The recording head 48W discharges a plurality of ink droplets from the discharge ports under the control of the control unit 20, and forms an image on the recording medium P that is transported by the transport unit 12 and passes through the opposing position.
Specifically, the recording head 48W discharges the first ink droplet d1 on the recording medium P. The first ink droplets d1 ejected from the recording head 48W land on the surface of the liquid film 8 of the recording medium P as shown in FIG. As described above, since the surface of the recording medium P is the liquid film 8 and the surface is not cured, the ink droplet d1 and the surface of the recording medium P are easily compatible.
Further, as shown in FIG. 9C, the second ink droplet d2 is ejected in the vicinity of the landing position of the first ink droplet d1 ejected previously. Also at this time, since the surface of the recording medium is the liquid film 8 and the surface is not cured, it is easy to become familiar with the ink droplet d2.
In addition, when the ink droplet d1 and the ink droplet d2 are landed in the vicinity of the recording medium P, a force that tries to unite the ink droplet d1 and the ink droplet d2 works. 8 becomes a resistance force to the coalescence between the ink droplets, and the interference between the ink droplets landed on the recording medium P is suppressed.

  In this manner, a plurality of ink droplets are ejected from the recording head 48W and landed on the recording medium P, thereby forming an image.

The recording medium P on which an image is formed by the recording head 48W is further transported by the transport unit 12, and passes through a position facing the ultraviolet irradiation unit 52 disposed downstream of the recording head 48W.
The ultraviolet irradiation unit 52 irradiates the recording medium P passing through the opposite position with ultraviolet rays, and the image formed on the recording medium P by the recording head 48W is semi-cured, that is, ink landed on the recording medium. Only the inside of the droplet is cured.

Thereafter, the recording medium P is further transported and passes through the positions facing the recording head 48C, the ultraviolet irradiation unit 52, the recording head 48M, the ultraviolet irradiation unit 52, the recording head 48Y, the ultraviolet irradiation unit 52, and the recording head 48K in this order. . Each time the recording medium P passes through a position facing the recording head and the ultraviolet irradiation unit of each color, an image is formed in the same manner as when passing through a position facing the recording head 48W and the ultraviolet irradiation unit 52. The formed image is semi-cured.
In this way, even when an ink droplet lands on the formed image by semi-curing the ink layer, that is, the ink layer, the ink droplet and the liquid film are similar to the above-described relationship between the ink droplet and the liquid film. The ink layer becomes easy to adjust, and interference between the ink droplets is suppressed.

The recording medium P passes through a position facing the final curing ultraviolet irradiation unit 52a after an image is formed by the recording head 48K.
The final curing ultraviolet irradiation unit 52a irradiates the recording medium P with ultraviolet light having a stronger intensity than the other ultraviolet irradiation units, and the recording medium P formed by various heads including an image recorded by the recording head 48K. The upper image and the liquid film 8 of the recording medium P are cured.
Further, the curing accelerating unit 19 is a recording medium P passing through a position facing the final curing ultraviolet irradiation unit 52a and an image on the recording medium P, that is, an ink layer formed by each recording head and the recording medium P. The liquid film 8 is heated to promote curing.
In this way, a color image is formed on the recording medium P.

The recording medium P on which the color image is formed is further transported by the transport roll pair 34 and taken up by the collection roll 36.
The ink jet recording apparatus 10 forms an image on the recording medium P in this way.

In this way, a recording medium having a microcapsule coated on a base material was used, and before recording an image, the microcapsule on the base material was ruptured by a capsule breaking portion to form a liquid film on the base material. Later, by recording an image, it is possible to prevent the ink droplets from moving together and landing on adjacent positions.
In addition, by forming a liquid film on the surface of the recording medium, it is possible to suppress the liquid droplet from spreading due to the difference in surface tension between the liquid film and the ink liquid droplet, and it is possible to prevent the image from bleeding. Further, the adhesion with the ink droplets can be increased. As a result, a high-quality image can be formed, and a high-quality printed matter can be produced.

  Further, since the liquid film can be formed by rupturing the microcapsules, the liquid film can be formed without applying the liquid with the ink jet recording apparatus. Thereby, the apparatus configuration can be simplified. Furthermore, since it is not necessary to provide a coating mechanism that is complicated to maintain, and only a capsule breaking mechanism that is easy or unnecessary to maintain is provided, it is possible to improve the maintainability of the apparatus, that is, to reduce the number of times the apparatus is maintained. Can be reduced. Thereby, the system cost can be reduced.

  Further, as the liquid filling the microcapsule, that is, the liquid forming the liquid film, the active energy ray curable liquid as in the case of the ink, in this embodiment, the ultraviolet ray curable liquid is used to cure the image. That is, the ink layer (that is, the ink on the recording medium) can be cured simultaneously. For this reason, an apparatus structure can be simplified.

  Furthermore, by using a recording medium in which the thickness of the liquid film formed by rupturing the microcapsules is 1 μm or more and 3 μm or less, interference between ink droplets can be prevented more reliably, and higher image quality can be achieved. Can produce a simple printed matter.

Further, the curing promoting unit 19 heats the recording medium P irradiated with ultraviolet rays from the final curing ultraviolet irradiation unit 52a and the ink layer on the recording medium P to accelerate the curing, whereby the recording medium P An image in which the liquid film and white and CMYK ink layers are laminated can be suitably cured. That is, by heating in the curing accelerator, among the image area in which a plurality of ink layers are laminated, a layer on the recording medium side that is hard to reach ultraviolet rays and hard to cure, in this embodiment, a white ink layer and the like The liquid film of the recording medium can be cured well. In other words, by heating, it is possible to promote curing of the liquid film and the ink layer that are irradiated with ultraviolet rays and have started curing.
In addition, the liquid film and the ink layer can be cured without irradiating the liquid film of the recording medium and the ink layer (that is, the image) formed on the recording medium with high-intensity ultraviolet rays. As a result, the ink layer on the surface of the image (that is, the black (K) ink layer in the present embodiment) can be prevented from shrinking, and the image can be prevented from being cracked or disturbed during curing. In addition, an inexpensive ultraviolet irradiation device can be used as the final curing ultraviolet irradiation unit.
Further, by heating by the curing accelerator, the liquid film and the ink layer can be cured in a short time, and the transport path can be shortened. Thereby, a printed matter can be created at a higher speed, and the apparatus can be made compact.
Since the liquid film and the ink layer can be reliably cured in this way, the recording medium in a state where the liquid film and the ink layer are not completely cured is wound, and the image portion of the recording medium that comes into contact with the recording medium is wound. Transfer and adhesion to the back surface can be prevented, and a printed matter on which a high-quality image is formed can be suitably produced.

  Further, as in the present embodiment, even when an image is formed without completely curing the ink of each color in a semi-cured state, when the ultraviolet light is irradiated by the final curing ultraviolet irradiation unit 52a, By heating the film and the ink layer, curing of the liquid film and the ink layer of each color in a semi-cured state can be promoted, and the undercoat layer and the ink layer of each color can be cured. Moreover, a high-quality image can be formed by semi-curing the ink layer.

Even when white ink is used as in this embodiment, the liquid film that is farther from the ultraviolet irradiation part than the white ink layer and the white ink layer can be suitably cured by heating.
In other words, according to the present invention, even when a plurality of ink layers including a white ink layer are formed, the image formed on the recording medium and the liquid film of the recording medium can be suitably and reliably cured. It is possible to produce a high-quality printed matter.

Further, it is preferable that the curing accelerating portion is disposed to face the back side of the recording medium as in the present embodiment. By heating from the back side of the recording medium, it is possible to efficiently heat the image area on the recording medium side, that is, the part where ultraviolet rays are difficult to reach. Thereby, the liquid film of the recording medium and the ink layer formed on the recording medium can be suitably cured.
As described above, it is preferable that the curing accelerating portion is disposed so as to face the back side of the recording medium, but it is disposed so as to face the surface side, that is, the surface on which the image of the recording medium is formed. May be. When the curing accelerating portion is disposed on the surface side of the recording medium, it is preferable to use a heating unit that heats the recording medium and the ink layer such as an infrared LED, an infrared LD, and a hot air heater in a non-contact manner. By using a non-contact type heating means as the curing accelerating portion, the recording medium and the ink layer can be heated without causing disturbance, streaks, unevenness, etc. on the image formed on the recording medium. That is, curing of the recording medium and the ink layer can be promoted.

Here, when a heating means is used as the curing accelerator, the curing accelerator preferably heats the recording medium to 40 degrees or more and 100 degrees or less, and more preferably heats the recording medium to 50 degrees or more and 90 degrees or less.
By setting the temperature at which the recording medium is heated by the curing accelerator to 40 ° C. or more, more preferably 50 ° C. or more, curing of the ink layer and the undercoat layer can be promoted, and curing can be performed more reliably. Further, by setting the temperature at which the recording medium is heated by the curing accelerating unit to 100 degrees or less, preferably 90 degrees or less, it is possible to prevent the moisture of the recording medium from being excessively evaporated. Waves can be prevented from occurring.

In this embodiment, the curing accelerating portion is disposed at a position facing the final exposure ultraviolet irradiation unit, and the recording medium at a position irradiated with ultraviolet rays for completely curing the liquid film and the ink layer is heated. However, the present invention is not limited to this, and the curing accelerating portion may be disposed downstream of the final exposure ultraviolet irradiation unit in the recording medium conveyance direction. That is, the image recording apparatus may have a configuration in which the recording medium and the ink layer are heated by the curing accelerating unit after the ultraviolet ray for completely curing the liquid film and the ink layer is irradiated.
As described above, the liquid film and the recording medium side ink layer can be cured also by heating the liquid film and the ink layer after being irradiated with the ultraviolet rays by the final exposure ultraviolet irradiation unit.

Here, it is preferable to use a transparent member as the recording medium. By using a transparent recording medium, the liquid film and / or the ink layer can be suitably heated from the back surface.
The recording head 48W preferably forms an ink layer over the entire image recording area of the recording medium. By forming an ink layer of white ink over the entire image recording area, an image with high visibility can be formed even when a transparent member, metal, or the like is used as a recording medium.

  Here, the conveyance speed of the recording medium P by the conveyance unit 12 is preferably 200 mm / s or more and 600 mm / s or less. Thereby, a high-quality image can be efficiently formed on the recording medium. In addition, printed matter can be created at high speed. That is, a large amount of recording media can be printed in a short time.

In the present embodiment, a pair of pressure rolls that applies a predetermined pressure to the recording medium is used as the capsule breaking portion. In combination with the type of microcapsule used, a method of bursting the microcapsule by applying energy such as heat or light can also be used. Specifically, means for rupturing the microcapsule by applying energy and thermal energy to the recording medium using an LD, LED, thermal head, or the like can also be used.
Moreover, you may use the means which can rupture a microcapsule by several methods as a capsule destruction part.

In addition, an ultraviolet irradiation unit is placed between each recording head, and the ink droplets landed on the recording medium by each recording head, that is, the image is semi-cured, so that the ink droplets landed on the adjacent positions move. Thus, it is possible to prevent the ink droplets from spreading and the ink droplets from spreading and to prevent the image from bleeding. Also, liquid films of different colors can be suitably stacked, and good color reproduction is possible.
The ultraviolet irradiation unit irradiates ultraviolet rays for several hundred milliseconds to five seconds after the ink droplets land on the recording medium by the recording head, that is, ink droplets that land on the recording medium, that is, The ink layer is preferably semi-cured.
By semi-curing the ink droplets within a few hundred milliseconds to 5 seconds after the ink droplets have landed, the shape of the ink droplets on the recording medium can be prevented from collapsing, and high-quality images can be formed. can do.

In addition, as in the present embodiment, the ultraviolet irradiation unit is configured by a plurality of ultraviolet irradiation units arranged in a straight line, that is, the plurality of ultraviolet irradiation units irradiate the entire area in the width direction of the recording medium with ultraviolet rays. With this configuration, the ultraviolet irradiation region of each ultraviolet irradiation unit can be reduced, an inexpensive light source can be used as the UV lamp, and an inexpensive driving mechanism can be used as the driving mechanism. Thereby, apparatus cost can be reduced. In addition, although an apparatus cost becomes high, of course, you may comprise an ultraviolet irradiation unit with one ultraviolet irradiation part.
In this embodiment, the ultraviolet irradiation unit is arranged in a straight line on a straight line orthogonal to the recording medium conveyance direction, but the ultraviolet irradiation unit is different in the recording medium conveyance direction, that is, orthogonal to the conveyance direction. You may arrange in a staggered pattern on a plurality of straight lines parallel to the direction.

  Further, in this embodiment, the UV lamps of the ultraviolet irradiation unit are arranged in a straight line on a straight line orthogonal to the recording medium conveyance direction, but the UV lamps are located at different positions in the recording medium conveyance direction, that is, conveyance. You may arrange | position in zigzag form on the some straight line parallel to the direction orthogonal to a direction.

  In addition, the ultraviolet irradiation unit corresponding to the recording head disposed on the most downstream side in the transport path of the recording medium is used as a final curing ultraviolet irradiation unit, and ultraviolet rays having a stronger intensity than other ultraviolet irradiation units are emitted. The image formed on the recording medium can be reliably cured.

Further, the ultraviolet irradiation unit may be provided with an openable / closable shutter capable of blocking the ultraviolet rays irradiated to the recording medium P side.
By providing a shutter and blocking the irradiated ultraviolet light, it is possible to prevent the ultraviolet light from leaking more than necessary to the recording medium P side, and the recording head is irradiated with the ultraviolet light reflected by the recording medium P. Ink can be prevented from being cured. Further, by providing a shutter, irradiation / non-irradiation of ultraviolet rays can be switched without turning on / off a light source such as a UV lamp.

  In addition, it is preferable to perform a light reflection preventing treatment (for example, a matte black treatment) on each part in the vicinity of the ultraviolet irradiation unit 54.

Next, another example of the ink jet recording apparatus of the present invention will be described.
FIG. 10 is a front view showing a schematic configuration of an ink jet recording apparatus according to another example of the present invention.
The ink jet recording apparatus 80 is the same as the ink jet recording apparatus 10 except for the configuration in which the liquid film semi-curing part 14 is provided between the capsule breaking part 13 and the image recording part 16. These components are denoted by the same reference numerals, description thereof is omitted, and points unique to the inkjet recording apparatus 80 will be described.

The inkjet recording apparatus 80 includes a transport unit 12 that transports the recording medium P, a capsule breaking unit 13 that bursts the microcapsules of the recording medium P, and a microcapsule of the recording medium P that bursts on the substrate surface. The liquid film to be formed is irradiated with ultraviolet rays to semi-cure the liquid film, a liquid film semi-curing part 14, an image recording part 16 that is supported by the support part 15 and records an image on the recording medium P, and a support part 15. An image fixing unit 18 for fixing an image recorded on the recording medium P supported by the image forming unit, a curing accelerating unit 19 for accelerating the curing of the recording medium P on which the image has been recorded, and an ink droplet of the image recording unit 16 And a control unit 20 that controls discharge.
Here, the transport unit 12, the capsule breaking unit 13, the support unit 15, the image recording unit 16, the image fixing unit 18, the curing accelerating unit 19, and the control unit 20 have the same configuration as each unit of the inkjet recording apparatus 10. Detailed description thereof is omitted.

The liquid film semi-curing unit 14 includes a UV lamp and is disposed to face the conveyance path of the recording medium P. Here, the UV lamp is a light source that emits ultraviolet light, and various ultraviolet light sources such as a metal halide lamp and a high-pressure mercury lamp can be used.
The liquid film semi-curing portion 14 irradiates the entire area in the width direction of the recording medium P passing through the facing position with ultraviolet rays.

The liquid film semi-curing unit 14 irradiates the liquid film 8 on the base material 2 of the recording medium P passing through the opposing position with ultraviolet rays so that the liquid film on the surface of the recording medium P is in a semi-cured state. That is, the liquid film semi-curing unit 14 makes the liquid film of the recording medium P semi-cured.
Thus, by semi-curing the liquid film of the recording medium P, a higher quality image can be formed.
Specifically, as described above, it is possible to prevent union of adjacent ink droplets due to movement of the ink droplets and wetting and spreading of the ink droplets, and it is possible to prevent line bleeding such as image bleeding and fine lines in the image. It can effectively prevent the occurrence of unevenness and color unevenness on the colored surface, can form sharp lines with a uniform width, and can record ink jet images with high droplet ejection density, such as reversed characters, as a fine image such as fine lines Can be performed with good reproducibility. Furthermore, liquid films of different colors can be suitably stacked, and good color reproduction is possible.

  In addition, by providing a liquid film semi-cured part and semi-curing the liquid film of the recording medium, a high-quality image can be formed regardless of the film thickness of the liquid film formed by rupturing the microcapsules. Can do. That is, even when a recording medium having a liquid film thickness of 3 μm or more formed by rupturing microcapsules is used, a high-quality image can be formed, and a high-quality printed matter can be created. .

Here, in the present embodiment, as described above, since different color inks can be prevented from being mixed and a higher quality image can be formed, an ultraviolet irradiation unit is arranged between the recording heads of each color, The image portion on the recording medium, that is, the ink layer was semi-cured each time an image was recorded in the present invention, but the present invention is not limited to this, and one ultraviolet irradiation unit is arranged for a plurality of recording heads. It is good also as a structure.
For example, as shown in FIG. 11, an ink jet recording apparatus 90 in which the image fixing unit 91 includes only the final curing ultraviolet irradiation unit 52a can be suitably used.
The inkjet recording apparatus 90 has the same configuration as that of the inkjet recording apparatus 10 shown in FIG. 5 except for the configuration of the image fixing unit 91.
The ink jet recording apparatus 90 ruptures the microcapsules on the substrate surface of the recording medium P by the capsule breaking unit 13 to form a liquid film on the substrate, and then uses the recording heads 48W, 48C, 48M, 48Y, and 48K. An image is formed on the recording medium P, and then the recording medium P is irradiated with ultraviolet rays by the final curing ultraviolet irradiation unit 52a to cure each ink layer and the liquid film of the recording medium.
Further, the recording medium P irradiated with the ultraviolet rays from the final curing ultraviolet irradiation unit 52a is heated by the curing accelerating unit 19 to accelerate the curing of each ink layer and the liquid film of the recording medium.

As described above, even in the configuration in which the ultraviolet irradiation unit is not arranged corresponding to each recording head, the microcapsule is ruptured by the capsule breaking unit before the ink droplet is ejected by the image recording unit, and the liquid is applied on the substrate. By forming a film, an image can be suitably recorded on the recording medium P.
In addition, when curing an image formed by a plurality of recording heads (that is, a plurality of ink layers) and a liquid film of a recording medium by irradiating with ultraviolet rays from one ultraviolet irradiation unit, the curing acceleration unit heats the effect. , The ink layer on the recording medium side and the liquid film on the recording medium can be reliably cured.

In this embodiment, the recording head unit has five colors of white (W) and CMYK. However, various combinations such as four or more colors of CMYK and six or more colors having heads of other special colors. It can also be a head. Further, the arrangement order of the recording heads of the respective colors is not particularly limited, and can be an arbitrary order.
Further, the present invention is not limited to the arrangement of a plurality of recording heads, and may be an ink jet recording apparatus that forms a single color image on a recording medium using a single recording head.

Next, a digital label printing apparatus using the inkjet recording apparatus of the present invention will be described.
FIG. 12 is a front view showing a schematic configuration of an example of a digital label printing apparatus using the inkjet recording apparatus of the present invention, and FIG. 13 is a block diagram showing a control unit that controls the digital label printing apparatus shown in FIG. FIG. 14 is a longitudinal sectional view of a recording medium P ′ for label printing used in the digital label printing apparatus shown in FIG.

The digital label printing apparatus of the present embodiment records an image on a continuous paper-like recording medium P ′ for label printing by a drawing unit, then cuts a label shape by a die cutter of a post-processing unit, and further removes unnecessary portions. This is an embodiment in which a scrap removal operation for peeling and removing an adhesive sheet from a mount (release paper) is performed as a post-process.
In each of the following embodiments, an actinic ray curable digital label printing apparatus using an ultraviolet ray curable ink among actinic ray curable inks cured by actinic ray irradiation will be described as an example, but the present invention is not limited thereto. In other words, the present invention can be applied to a digital label printing apparatus using various actinic ray curable inks, and any other type of digital label printing apparatus.
Further, in the recording medium P ′ of the present embodiment, as shown in FIG. 14, the base material 179 has the adhesive sheet 180 having the back surface coated with the adhesive 180 a on the release paper 182 as a mount. The capsule layer 6 having a microcapsule 4 is formed on the surface of the pressure-sensitive adhesive sheet 180 of the base material 179.
That is, the recording medium P ′ of the present embodiment is the same as the recording medium shown in FIG. 1 except that the base material 179 is composed of the adhesive sheet 180 and the release paper 182 that can be peeled. The configuration is the same as P.

As shown in FIG. 12, the digital label printing apparatus 100 includes a transport unit 110, a capsule breaking unit 13, a support unit 15, an image recording unit 16, an image fixing unit 18, and a drawing accelerating unit 19, and a drawing unit 112. A processing unit 114 and a control unit 116 are included.
Here, the conveying unit 110 conveys a continuous paper-like recording medium P ′ for label printing (hereinafter referred to as “recording medium P ′”) in a certain direction (from left to right in FIG. 12). The drawing unit 112 and the post-processing unit 114 are arranged in the order of the transport direction of the recording medium P ′, that is, from the upstream to the downstream, in the order of the capsule breaking unit 13, the drawing unit 112, and the post-processing unit 114. Although part of the illustration is omitted in FIG. 12, the control unit 116 is connected to the capsule breaking unit 13, the transport unit 110, the drawing unit 112, and the post-processing unit 114, and controls the operation of each unit. .

The conveyance unit 110 includes a supply roll 30, a conveyance roll pair 126, 128, 130, and 132, a product winding unit 134, and conveyance motors 128a and 134a.
A continuous paper-like recording medium P ′ for label printing is wound around the supply roll 30 in a roll shape.
The conveyance roll pairs 126, 128, 130, and 132 are arranged in this order from the upstream to the downstream of the conveyance path of the recording medium P ′. The transport roll pairs 126, 128, 130, and 132 feed the recording medium P ′ from the supply roll 30 and transport the recording medium P ′ in a predetermined direction (in this embodiment, from left to right in FIG. 12).
The product take-up unit 134 is disposed on the transport path of the recording medium P ′, that is, the most downstream in the transport direction, and is transported on the transport path by the pair of transport rolls 126, 128, 130, 132, the capsule breaking unit 13, and the drawing The recording medium P ′ that has passed through the section 112 and the post-processing section 114 is taken up.
The conveyance motors 128a and 134a are connected to the conveyance roll pair 128 and the product winding unit 134, respectively, and rotate the conveyance roll pair 128 and the product winding unit 134.

That is, in this embodiment, the pair of transport rolls 128 connected to the transport motors 128a and 134a and the product take-up unit 134 are rotationally driven to serve as drive rollers for transporting the recording medium P ′, and other transport roll pairs 126 are used. , 130 and 132 are driven rollers that rotate in accordance with the movement of the recording medium P ′ and regulate the recording medium P ′ on the transport path.
The transport unit 110 drives the transport motors 128 a and 134 a to rotate the transport roll pair 128 and the product winding unit 134. As a result, the recording medium P ′ is fed out from the supply roll 30, passes through the capsule breaking unit 13, the drawing unit 112, and the post-processing unit 114, and is taken up by the product winding unit 134.

In the present embodiment, a transport buffer is provided between the drawing unit 112 and the post-processing unit 114.
By providing the transport buffer, it is possible to absorb the slack of the continuous sheet-like recording medium P ′ for label printing caused by the difference in transport speed between the drawing unit 112 and the post-processing unit 114, and efficiently manufacture labels. be able to.

Further, the conveyance motors 128a and 134a are connected to a conveyance motor control unit 195, which will be described later, and the rotation speed is controlled, and the conveyance speed of the continuous sheet-like recording medium P ′ for label printing by the conveyance unit 110 is controlled. The
In addition, the conveyance roll pair used as a drive roll pair is not specifically limited, For example, a conveyance motor is provided in all the conveyance roll pairs, and it is good also considering all the conveyance roll pairs as a drive roll pair.

The capsule breaking unit 13 has the pressure roll pair 60 as described above. Since the configuration and function of each part of the capsule destroying unit 13 are the same as those of the capsule destroying unit 13 of the inkjet recording apparatus 10 described above, detailed description thereof is omitted.
The pressure roll pair 60 of the capsule breaking unit 13 sandwiches the recording medium P ′ that is pulled out and conveyed from the supply roll 30 and pressurizes the recording medium P ′ with a predetermined pressure, thereby rupturing the microcapsules 4 on the adhesive sheet 180.
Thereby, a liquid film is formed on the surface of the pressure-sensitive adhesive sheet 180 of the recording medium P ′.

The drawing unit 112 includes a support unit 15, an image recording unit 16, an image fixing unit 18, and a curing promoting unit 19.
Various configurations of the support unit 15, the image recording unit 16, the image fixing unit 18, and the curing accelerating unit 19 are the same as the support unit 15, the image recording unit 16, and the image fixing unit of the inkjet recording apparatus shown in FIG. 18 and the same as the curing accelerating portion 19, and detailed description thereof is omitted.
The drawing unit 112 also has a recording head 48W of the recording head unit 46 of the image recording unit 16 on the head surface plate 40 supported by the main body surface plate 38 of the support 15 arranged to face the conveyance path of the recording medium P ′. , 48C, 48M, 48Y, 48K are disposed, and the ultraviolet irradiation units 54 and 54a of the ultraviolet irradiation unit 52 and the final exposure ultraviolet irradiation unit 52a that are individually supported by the illumination unit support 42 on the main body surface plate 38, respectively. Is arranged.
Also, the recording heads 48W, 48C, 48M, 48Y, 48K and the ultraviolet irradiation unit 52 are arranged from the upstream side to the downstream side of the transport path from the recording head 48W, the ultraviolet irradiation unit 52, the recording head 48Y, the ultraviolet irradiation unit 52, and the recording head. Similarly, the arrangement 48M, the ultraviolet irradiation unit 52, the recording head 48C, the ultraviolet irradiation unit 52, the recording head 48K, and the final curing ultraviolet irradiation unit 52a are arranged in this order.
Further, the curing accelerating unit 19 is disposed at a position facing the final curing ultraviolet irradiation unit 52a on the back surface side of the recording medium P ′.
The drawing unit 112 ejects ink droplets from each recording head, and then irradiates ultraviolet rays from each ultraviolet irradiation unit 52 to semi-cure each ink layer on the recording medium P ′. Further, the drawing unit 112 irradiates the final curing ultraviolet irradiation unit 52a with ultraviolet rays, and the curing accelerating unit 19 heats the ink layer on the recording medium P ′ and the liquid film of the recording medium P ′, The ink layer on the recording medium P ′ and the liquid film of the recording medium are cured. The drawing unit 112 thus forms an image on the recording medium P ′.

The post-processing unit 114 is arranged on the downstream side of the ultraviolet irradiation unit 52a corresponding to the recording head 48K in the conveyance direction of the recording medium P ′, and is an actinic ray curable transparent liquid (in this embodiment, an ultraviolet curable type). The varnish coater 162 and the ultraviolet irradiation unit 164 for improving the gloss by applying a transparent liquid) to the image surface, the die cutter 166 for cutting the label shape on the continuous recording medium P ′, and the unnecessary part peeling unit And a debris removal portion 172.
A transport buffer is provided between the ultraviolet irradiation unit 52a corresponding to the recording head 48K and the varnish coater 162 as described above.

The varnish coater 162 supplies a transparent actinic ray (ultraviolet ray in this embodiment) curable liquid (hereinafter also referred to as “active light curable transparent liquid” or simply “transparent liquid”) to the surface of the recording medium P ′. Liquid supply means, which is disposed downstream of the ultraviolet irradiation unit 52a corresponding to the recording head 48K in the conveyance direction of the recording medium P ′.
The varnish coater 162 has a pair of coating rolls with an ultraviolet curable transparent liquid adhered (impregnated) on the surface thereof, and supports the movement of the recording medium P ′ while sandwiching the recording medium P ′ ( By rotating in synchronization, the ultraviolet curable transparent liquid is applied to the surface of the recording medium P ′ pressed with foil (the surface on which the image is formed).

  Here, the transparent liquid applied by the varnish coater 162 is an actinic ray curable transparent liquid that can be cured by ultraviolet irradiation, and contains at least a polymerizable compound and a photoinitiator as main components, for example, a cationic polymerization composition. , Radical polymerization compositions, aqueous compositions and the like. Details will be described later.

The ultraviolet irradiation unit 164 is disposed on the downstream side of the varnish coater 162 in the conveyance direction of the recording medium P ′. The ultraviolet irradiation unit 164 irradiates the recording medium P ′ with actinic rays (ultraviolet rays in the present embodiment) to cure the ultraviolet curable transparent liquid applied to the surface of the recording medium P ′. In addition, the ultraviolet irradiation part 164 can also be set as the structure which arrange | positioned the several ultraviolet irradiation part similarly to the above-mentioned ultraviolet irradiation unit. Further, as the ultraviolet irradiation unit 164, various configurations shown in the ultraviolet irradiation unit 54 described above can be used.
By applying and curing an ultraviolet curable transparent liquid on the surface of the recording medium P ′, the image surface of the recording medium P ′ can be given gloss, and the image quality can be improved.

As shown in FIG. 15, the die cutter 166 is formed only on the pressure-sensitive adhesive sheet 180 of the printed continuous paper-like recording medium P ′ for label printing (more precisely, the image portion, the liquid film 8, and the pressure-sensitive adhesive sheet 180). And a cylinder cutter 168 disposed on the downstream side of the ultraviolet irradiation unit 164 in the conveyance direction of the recording medium P ′ and disposed on the image surface side of the recording medium P ′. And a receiving roller 170 disposed on the opposite side of the cylinder cutter 168 across the recording medium P ′.
The cylinder cutter 168 includes a cylindrical cylinder 168a and a plurality of cutting blades 168b wound around the cylindrical surface of the cylinder 168a and formed in a label shape.

  The die cutter 166 oscillates and rotates intermittently in synchronization with the conveyance speed of the recording medium P ′ while the recording medium P ′ is sandwiched between the cylinder cutter 168 and the receiving roller 170, so that the cutting blade 168b is covered. A label-shaped cut is made only in the adhesive sheet 180 of the recording medium P ′ (see FIG. 15).

  Here, as shown in FIG. 16, when the circumferential length CL of the cylindrical surface of the cylinder 168a is not an integral multiple of the length LL of the label L, in other words, the circumferential direction of the cylindrical surface of the cylinder 168a. When the length CL and the length CL1 of the cutting blade 168b do not match, a blank portion B where the cutting blade 168b is not provided is generated on the cylindrical surface of the cylinder 168a.

  In this case, when the die cutter 166 is continuously rotated and a label-shaped cut 180b is made, the space between the label group LB containing the previous cut 180b and the label group LA containing the current cut 180b corresponds to the blank portion B. A large unnecessary portion P1 is formed, and the continuous paper-like recording medium P ′ for label printing is wasted.

  On the other hand, in this embodiment, the die cutter 166 is intermittently swung in order to eliminate the formation of useless unnecessary portions P1. As a result, as shown in FIG. 17, the next cut 180b can be made in succession to the rear end of the label group LB having the previous cut 180b. Thus, even when the circumferential length CL of the cylinder surface of the cylinder 168a and the length LL of the label L are not an integral multiple, the generation of the unnecessary portion P1 between the label L groups LB and LA is eliminated, and the continuous paper Can be used efficiently.

The scrap removing part 172 peels off an unnecessary part (peripheral part of the label L) of the adhesive sheet 180 that does not become the label (product) L from the release paper 182 and winds it up.
The recording medium P ′ in which the unnecessary portion is wound, that is, the recording medium P ′ in which only the label L is attached to the release paper 182 is wound around the product winding unit 134 to be a product.

Next, the control unit 116 that controls the transport unit 110, the drawing unit 112, and the post-processing unit 114 will be described.
As shown in FIG. 13, the control unit 116 includes a memory 191 that stores recording image data for ink ejection by the recording heads 48W, 48C, 48M, 48Y, and 48K of the recording head unit 46, and recording image data. Based on the head drive control unit 192 that drives and controls the recording heads 48W, 48C, 48M, 48Y, and 48K of the recording head unit 46, and image data analysis that analyzes the shape of the label L based on the image data stored in the memory 191 Unit 193, a conveyance speed changing unit 194 that changes the conveyance speed of the recording medium P ′ for continuous label printing based on the shape of the label L analyzed by the image data analysis unit 193, and a conveyance speed changing unit 194 A transport motor control unit 195 for controlling the rotational speed of the transport motors 128a and 134a based on the transport speed changed by The die cutter control unit 196 controls the rotational speed of the die cutter 166 based on the transport speed changed by the transport speed changing unit 194.

An input unit 199 such as a computer is connected to the memory 191 of the control unit 116. The memory 191 stores the recording image data input from the input unit 199.
Further, the head drive control unit 192 selects and discharges ejection ports for ejecting ink droplets of the recording heads 48W, 48C, 48M, 48Y, and 48K of the recording head unit 46 based on the image data stored in the memory 191. The amount of ink droplets to be discharged, the ejection timing, and the like are calculated, and the recording head unit 46 is controlled based on the calculation result. As an example, in the case of a piezo-type inkjet head as in the present embodiment, a piezoelectric element to which a voltage is applied and a voltage value to be applied among a plurality of ejection portions (ejection ports) according to image data. The application time, application timing, and the like are calculated, and an ejection signal is sent to the recording heads 48W, 48C, 48M, 48Y, and 48K based on the calculation results.

The image data analysis unit 193 analyzes the shape of the label L from the label edge data of the image data stored in the memory 191, and sends the analysis result to the conveyance speed change unit 194.
The conveyance speed changing unit 194 stores in advance a conveyance speed that is optimal for post-processing for each shape of the label L, and is analyzed by the image data analysis unit 193 and calculated from the label edge data that has been sent. The optimum transport speed of the recording medium P ′ is calculated from the shape and the stored transport speed, and the calculation result is sent to the transport motor control unit 195 and the die cutter control unit 196.
The transport motor control unit 195 controls the rotation speeds of the transport motors 128a and 134a based on the optimal transport speed calculated by the transport speed changing unit 194. As a result, the continuous paper-like recording medium P ′ for label printing is conveyed at an optimum speed.

The die cutter control unit 196 controls the rotational speed of the die cutter 166 based on the optimum transport speed calculated by the transport speed changing unit 194. Specifically, the rotational speed of the die cutter 166 is controlled so that the conveyance speed of the recording medium P ′ and the peripheral speed of the cutting blade 168b of the die cutter 166 become the same speed.
As described above, the control unit 116 changes or adjusts the conveyance speed of the recording medium P ′ conveyed through the post-processing unit 114 based on the label shape data calculated from the label edge data.

  Further, it is preferable that the conveyance speed changing unit 194 controls the conveyance speed of the recording medium P ′ to be slowed at a label portion position that is weak against unnecessary part peeling based on the shape data of the label L. As a result, it is possible to prevent tearing and breakage during scrap removal, and to reliably remove unnecessary portions other than the label portion.

  Specifically, as conditions where tearing and breakage are likely to occur due to unnecessary part peeling, depending on the material of the adhesive paper, if the width of the unnecessary part is 5 mm or less, if there is an acute angle part of 30 degrees or less, The optimum peeling speed determined in advance under each condition is set in the conveyance speed changing unit 194, and these optimum peeling speeds are further taken into consideration, so that the optimum conveyance speed of the recording medium P ′ is set. Is preferably calculated.

Next, a method for creating a label by the digital label printing apparatus 100 will be described.
As shown in FIG. 12, the recording medium P ′ sent out from the supply roll 30 wound in a roll shape is transported by the transport unit 110 and pressurized to the pressure roll pair 60 of the capsule breaking unit 13 with a predetermined pressure. As a result, the microcapsule is ruptured, and a liquid film is formed on the surface of the pressure-sensitive adhesive sheet 180 of the substrate 179 of the recording medium P. The recording medium P is transported to the drawing unit 112 after the liquid film is formed.

  The recording medium P ′ conveyed to the drawing unit 112 passes through a position facing the recording heads 48W, 48C, 48M, 48Y, and 48K.

The recording heads 48W, 48C, 48M, 48Y, and 48K discharge the ink droplets of the ultraviolet curable ink to the recording medium P ′ that passes through the opposing positions based on the control by the control unit 116. The recording medium P ′ from which the ink has been ejected is further conveyed, passes through a position facing the ultraviolet irradiation unit 52, is irradiated with ultraviolet rays, and the ink is semi-cured.
That is, when the recording medium P ′ passes through the positions facing the recording heads 48W, 48C, 48M, 48Y, and 48K, the ink liquid is directed from the recording heads 48W, 48C, 48M, 48Y, and 48K toward the recording medium P ′. Drops are ejected. The recording medium that has passed the positions facing the recording heads 48W, 48C, 48M, and 48Y is irradiated with ultraviolet rays from the ultraviolet irradiation unit 52, and each ink layer formed on the recording medium is semi-cured. Further, the recording medium on which an image is formed by the recording head 48K is irradiated with ultraviolet rays from the final curing ultraviolet irradiation unit 52a, and further heated by the curing accelerating unit 19, so that each ink layer on the recording medium and the recording medium are recorded. The liquid film of the medium is cured. In this way, an image is formed on the surface of the recording medium P ′.

The recording medium P ′ on which the image is formed is transported to the post-processing unit 114 via the transport buffer, and an ultraviolet curable transparent liquid is applied to the surface of the recording medium P ′ by the varnish coater 162, and then the ultraviolet light is applied. Cured by the irradiation unit 164.
The recording medium P ′ coated with the ultraviolet curable transparent liquid is conveyed to the die cutter 166, and the cut 180b is formed in the shape of the label L only on the adhesive sheet 180 by the cylinder cutter 168 and the receiving roller 170.
At this time, as described above, since the die cutter 166 makes the cut line 180b having the shape of the label L while swinging intermittently, the cut line 180b can be continuously formed, and the recording medium P ′ is wasted. This part never occurs.

Thereafter, unnecessary portions other than the label L of the pressure-sensitive adhesive sheet 180 of the recording medium P ′ are peeled off from the release paper 182 and taken up by the residue removing portion 172. The recording medium P ′ in a state where only the label L is stuck on the release paper 182 is wound around the product winding unit 134 to become a product.
A label is created as described above.

  In this way, using the recording medium in which the microcapsules are applied to the surface of the pressure-sensitive adhesive sheet of the substrate, the microcapsules of the recording medium P ′ are ruptured by the pressure roll pair 60 of the capsule breaking unit 13 to form a liquid film. As a result, an image without image unevenness can be formed on the recording medium, and a high-quality and high-quality label can be manufactured.

  Further, according to the digital label printing apparatus 100 of the present embodiment, the transport speed changing unit 194 reduces the transport speed of the recording medium P ′ at a label portion position weak against unnecessary part peeling based on the label shape data. By processing, it is possible to prevent tearing and breakage of the label L during post-processing (at the time of scrap removal) and to reliably remove unnecessary portions other than the label portion. As a result, it is possible to improve productivity by eliminating an apparatus stop caused by tearing or breakage of the label L, and to provide the label L at low cost.

Next, another example of the digital label printing apparatus will be described with reference to FIGS.
Here, FIG. 18 is a front view showing a schematic configuration of another example of a digital label printing apparatus using the inkjet recording apparatus of the present invention, and FIG. 19 is a control for controlling the digital label printing apparatus shown in FIG. It is a block diagram which shows a part.
The digital label printing apparatus 200 shown in FIG. 18 has the same configuration as the digital label printing apparatus 100 shown in FIG. 12 except for the post-processing unit 214. Therefore, the same reference numerals are given to the same components in both, and the detailed description thereof will be omitted. Hereinafter, points unique to the digital label printing apparatus 200 will be mainly described.

  As illustrated in FIG. 18, the post-processing unit 214 of the digital label printing apparatus 200 includes a varnish coater 162, an ultraviolet irradiation unit 164, a laser cutter 220, and a residue removing unit 172. The varnish coater 162, the ultraviolet irradiation unit 164, and the residue removing unit 172 are the same as the varnish coater 162, the ultraviolet irradiation unit 164, and the residue removing unit 172 of the post-processing unit 114 shown in the digital label printing apparatus 100 of FIG. Description is omitted.

The laser cutter 220 forms a desired label-shaped cut 180b only in the adhesive sheet 180 of the recording medium P ′ for continuous label printing, which is printed in the same manner as the die cutter 166 of the digital label printing apparatus 100 of FIG. This is disposed between the ultraviolet irradiation unit 164 and the residue removing unit 172.
The laser cutter 220 irradiates the continuous paper-like recording medium P ′ for label printing to be conveyed with laser, and puts a label-shaped cut 180 b only on the adhesive sheet 180.

  The control unit 216 includes a memory 191 that stores recording image data for ink ejection by the recording heads 48W, 48C, 48M, 48Y, and 48K of the recording head unit 46, and the recording image data to the recording head of the recording head unit 46. Based on the shape of the label L analyzed by the image data analysis unit 193, the head drive control unit 192 for sending to 48W, 48C, 48M, 48Y, 48K, the image data analysis unit 193 for analyzing the shape of the label L A conveyance speed changing unit 194 that changes the conveyance speed of the recording medium P ′ for paper-like label printing, and a conveyance motor that controls the rotation speeds of the conveyance motors 128a and 134a based on the conveyance speed changed by the conveyance speed changing unit 194. And a control unit 195. That is, the control unit 216 of the present embodiment has the same configuration as the control unit 116 shown in FIG. 13 except that the die cutter control unit 196 is not provided.

The image data analysis unit 193 analyzes the image density at the label edge from the image data stored in the memory 191, and sends the analysis result to the conveyance speed change unit 194.
The conveyance speed changing unit 194 of the control unit 216 according to the present embodiment calculates the conveyance speed of the recording medium P ′ according to the density of the image density data of the label edge cut by the laser cutter 220.
In other words, the conveyance speed changing unit 194 stores in advance the optimum post-processing conveyance speed corresponding to the image density, and the image density of the label edge analyzed and sent by the image data analysis unit 193 is stored. The optimum transport speed is calculated from the transport speed that has been set, and the calculation result is sent to the transport motor control unit 195.
Specifically, the control is performed so that the conveyance speed of the recording medium P ′ is decreased at a position where the image density at the label edge is high. As a result, a portion having a high image density, that is, a portion where the label L is thick and difficult to be cut out by the laser is irradiated with a large amount of energy by slowing the conveying speed, and a label-shaped cut 180b is made in the adhesive sheet 180. .

  Here, in the transport speed changing unit, the condition for determining the transport speed is not limited to the image density, that is, the thickness of the ink film thickness, and is, for example, each condition such as a material that absorbs laser light of the ink. The optimum conveyance speed is determined in advance according to various conditions by a test, and can be set in the conveyance speed changing unit 194.

  The transport motor control unit 195 controls the rotation speeds of the transport motors 128a and 134a based on the transport speed changed by the transport speed changing unit 194. As a result, the continuous paper-like recording medium P ′ for label printing is conveyed at an optimum speed.

Next, a method for creating a label by the digital label printing apparatus 200 will be described.
Forming an image on the recording medium P ′ by the drawing unit 112 on the recording medium P ′ fed out from the supply roll 30 is the same as in the digital label printing apparatus 100 described above.

The recording medium P ′ on which the image is formed is transported to the post-processing unit 214 via the transport buffer, and an ultraviolet curable transparent liquid is applied to the surface of the recording medium P ′ by the varnish coater 162, and then the ultraviolet light is applied. Cured by the irradiation unit 164.
The recording medium P ′ coated with the ultraviolet curable transparent liquid is conveyed to the laser cutter 220 and irradiated with a laser, and a cut 180b is formed in the shape of the label L only on the adhesive sheet 180.

Thereafter, unnecessary portions other than the label L of the pressure-sensitive adhesive sheet 180 of the recording medium P ′ are peeled off from the release paper 182 and taken up by the residue removing portion 172. The recording medium P ′ in a state where only the label L is stuck on the release paper 182 is wound around the product winding unit 134 to become a product.
A label is created as described above.

Here, in the laser processing, it is necessary to apply energy according to the thickness of the label L, and the larger the thickness of the label L, the more energy is required.
In addition, when actinic ray curable ink is used as the ink, the cured ink is formed so as to rise on the adhesive sheet 180. The rising height of the cured ink is, for example, about 12 μm, and the color printing portion to which a plurality of (W, C, M, Y, K) inks are stacked and attached becomes even higher. When an actinic ray curable ink is used, a recording medium P ′ having no ink absorbability is often used, and this raised height increases as it is. In addition, since a large amount of ink adheres to a portion where the image density is high, the height of the rise increases and the portion becomes thicker. Further, in the case of the thinnest thickness of the recording medium P ′ for label printing, it is about 12 μm, which is thinner than the ink thickness, and the influence is further increased.

On the other hand, the digital label printing apparatus 200 according to the present embodiment is configured so that, in the conveyance speed changing unit 194 in the post-processing step, according to the density of the image density data at the label edge, specifically, the dark portion is processed with a laser. When cutting, the conveyance speed of the recording medium P ′ is adjusted to be slow, and the portion where the image density is high and the ink thickness is thick such as actinic ray curable ink is cut at a low speed by the laser cutter 220. A cut can be surely made only in the pressure-sensitive adhesive sheet, and partial cutouts can be prevented.
Further, it is possible to efficiently create a label without creating a blank portion on the recording medium.

Next, another example of the digital label printing apparatus will be described with reference to FIG.
Here, FIG. 20 is a front view showing a schematic configuration of another example of a digital label printing apparatus using the inkjet recording apparatus of the present invention.
In the digital label printing apparatus 500 shown in FIG. 20, the configuration of each part is basically the same except that the capsule destroying unit 13, the drawing unit 112, and the post-processing unit 214 are independent individual devices. The configuration is the same as that of the digital label printing apparatus 200 shown in FIG. Therefore, the same reference numerals are given to the same components in both, and the detailed description thereof will be omitted, and the following will focus on the points peculiar to the digital label printing apparatus 500.

  As shown in FIG. 20, the digital label printing apparatus 500 includes a capsule destruction unit 13, a preprocessing device (inkjet recording device) 501 having a drawing unit 112, and a postprocessing device 502 having a postprocessing unit 214.

Next, a characteristic part of the digital label printing apparatus 500 will be described together with a method of creating a label by the digital label printing apparatus 500.
The recording medium P ′ is installed on the first supply roll 30 of the pretreatment device 501, conveyed by the conveyance roll pair 126, and after the liquid film is formed by the capsule breaking unit 13, the recording medium P ′ is further conveyed to the drawing unit 112. The The recording medium P ′ conveyed to the drawing unit 112 forms an image on the surface by the recording heads 48W, 48C, 48M, 48Y, and 48K, the ultraviolet irradiation unit 52, the final exposure ultraviolet irradiation unit 52a, and the curing accelerating unit 19. Is done. The recording medium P ′ on which the image is formed is wound around the collecting roll 512. Here, in the present embodiment, the recovery roll 512 is provided with a drive motor 512a, and the recovery roll 512 is used as a drive roller.

  The recording medium P ′ on which the image is formed, that is, the recording medium P ′ wound around the collection roll 512 is set on the second supply roll 514 of the post-processing device 502. The recording medium P ′ installed on the second supply roll 514 is transported to the post-processing unit 214 by the transport rolls 130 and 132.

The recording medium P ′ on which the image is formed is coated with an ultraviolet curable transparent liquid by the varnish coater 162, and then the ultraviolet curable transparent liquid applied by being irradiated with ultraviolet rays from the ultraviolet irradiation unit 164 is cured.
Thereafter, the recording medium P ′ has a cut corresponding to the shape of the label L only on the adhesive sheet by the laser cutter 220, and further, an unnecessary portion of the adhesive sheet of the recording medium P ′ is peeled off by the residue removing portion 172. It is peeled off from the paper and wound up. On the other hand, the recording medium P ′ in which the unnecessary portion is wound and only the label portion of the pressure-sensitive adhesive sheet and the release paper are wound is wound around the product winding portion 134 to become a product.

  Also in this embodiment, the conveyance speed changing unit 194 calculates the optimum conveyance speed based on the image density of the label edge analyzed by the image data analysis unit 193. The transport motor control unit 195 transports the recording medium P ′ by controlling the rotational speed of the transport motor 134 a so that the calculated optimal transport speed is obtained. Specifically, when the portion having a high image density at the label edge is cut by the laser cutter 220, the conveyance speed of the recording medium P ′ is controlled to be slow.

In this way, the digital label printing device is a separate device as a pre-processing device and a post-treatment device, so that the pre-processing step of label L printing and image surface smoothing, foil stamping, transparent liquid application (glossy surface) The post-processing steps such as formation), scoring, and scrap removal can be performed as separate operations, and post-processing of various types of labels L can be performed collectively.
In general, the time required for printing is often slower than the time required for post-processing such as scrap removal, and one post-processing device 502 can handle a plurality of pre-processing devices 501. Efficient processing is possible.

  Even when the apparatus is separated in this way, only the pressure-sensitive adhesive sheet can be accurately cut by controlling the conveyance speed according to the value calculated based on the image data.

  Hereinafter, the ink that can be suitably used in the ink jet recording apparatus of the present invention will be described in detail.

(Ink physical properties)
Here, the physical properties of the ink (droplet) ejected on the recording medium vary depending on the apparatus, but generally the viscosity at 25 ° C. is preferably 5 to 100 mPa · s, and 10 to 80 mPa · s. It is more preferable that

  The composition of the ink may be selected so as to obtain a desired surface tension, but it is also preferable to contain a surfactant.

(Curing sensitivity of ink and inclusion liquid)
In the present invention, the curing sensitivity of the ink is preferably equal to or higher than the curing sensitivity of the inclusion liquid. Further, the curing sensitivity of the ink is more preferably not less than the curing sensitivity of the inclusion liquid and not more than 4 times the curing sensitivity of the inclusion liquid, and should be not less than the curing sensitivity of the inclusion liquid and not more than twice the curing sensitivity of the inclusion liquid. Is more preferable.
Here, the curing sensitivity is the amount of energy required for complete curing when the ink and / or inclusion liquid is cured using a mercury lamp (ultra-high pressure, high pressure, medium pressure, etc., preferably an ultra-high pressure mercury lamp). The smaller the amount of energy, the higher the sensitivity. Therefore, a curing sensitivity of 2 means that the amount of energy required for complete curing is ½.
Further, the phrase “curing sensitivity is equivalent” means that the difference in curing sensitivity between the two compared is 2 times or less, more preferably 1.5 times or less.

(ink)
Hereinafter, inks that can be suitably used in the present invention will be described in detail.
The ink has a composition that forms at least an image, and includes at least one polymerizable or crosslinkable material and a colorant, and if necessary, a polymerization initiator, an oleophilic solvent, and other components. Constructed using.
Here, as the polymerizable or crosslinkable material, the polymerization initiator, the oleophilic solvent, and other components used in the ink, the same materials as the above-mentioned inclusion liquid can be used.

The polymerization initiator is preferably capable of initiating a polymerization reaction or a crosslinking reaction by active energy rays. As a result, the undercoat liquid applied to the recording medium can be cured by irradiation with active energy rays.
Moreover, it is preferable that an ink contains the radically polymerizable composition mentioned above. When the ink contains the radically polymerizable composition, the ink curing reaction can be performed with high sensitivity in a short time.
The ink preferably contains a colorant. Further, each component constituting the ink will be described in detail below. In addition, about the component similar to an inclusion liquid, the detailed description is abbreviate | omitted.

(Polymerizable or crosslinkable material)
The polymerizable or crosslinkable material has a function of causing a polymerization or crosslinking reaction by an initiating species such as a radical generated from a polymerization initiator described later, and curing a composition containing these.

As the polymerizable or crosslinkable material, a polymerizable or crosslinkable material that causes a known polymerization or crosslinking reaction such as radical polymerization reaction or dimerization reaction can be applied. For example, an addition polymerizable compound having at least one ethylenically unsaturated double bond, a polymer compound having a maleimide group in the side chain, a cinnamyl group having a photodimerizable unsaturated double bond adjacent to the aromatic nucleus, Examples thereof include a polymer compound having a cinnamylidene group or a chalcone group in the side chain. Among these, an addition polymerizable compound having at least one ethylenically unsaturated double bond is more preferable, and from a compound (monofunctional or polyfunctional compound) having at least one terminal ethylenically unsaturated bond, more preferably two or more. It is particularly preferred that it is selected. Specifically, it can be appropriately selected from those widely known in the industrial field according to the present invention. For example, monomers, prepolymers (that is, dimers, trimers, and oligomers) and mixtures thereof, and those Those having a chemical form such as a copolymer of
A polymeric or crosslinkable material may be used individually by 1 type, and may be used in combination of 2 or more type.

  As the polymerizable or crosslinkable material in the present invention, it is preferable to use various known radically polymerizable monomers that cause a polymerization reaction with an initiating species generated from a radical initiator, as in the case of the inclusion liquid.

The content of the polymerizable or crosslinkable material in the ink is preferably in the range of 50 to 99.6% by mass, and 70 to 99.0% by mass with respect to the total solid content (mass) of each droplet. %, More preferably in the range of 80 to 99.0% by mass.
Moreover, as content in a droplet, it is preferable to set it as the range of 20-98 mass% with respect to the total mass of each droplet, The range of 40-95 mass% is more preferable, 50-90 mass% It is particularly preferable to set the range.

(Polymerization initiator)
In addition, the ink preferably contains at least one polymerization initiator as in the case of the inclusion liquid. This polymerization initiator generates radicals and other starting species by applying actinic light, heat, or both, and initiates, accelerates and cures the polymerization or crosslinking reaction of the polymerizable or crosslinkable material described above. A compound.

  The polymerization initiator is preferably selected and contained as long as the storage stability of the ink can be maintained within a desired level. Specifically, the content in the ink droplets is determined by the degree of polymerization in the ink. Or it is preferable to set it as 0.5-20 mass% with respect to a crosslinkable compound, and it is more preferable to set it as 1-15 mass%.

  Further, it is preferable to add a sensitizing dye and a co-sensitizer to the ink as in the case of the inclusion liquid.

(Coloring agent)
The colorant is not particularly limited, and can be appropriately selected from known water-soluble dyes, oil-soluble dyes, pigments, and the like. In particular, when the ink is composed of a water-insoluble organic solvent system that can suitably obtain the effects of the present invention, the colorant is an oil-soluble dye or pigment that is easily dispersed and dissolved in a water-insoluble medium. Is preferably used.

  The content of the colorant in the ink is preferably 1 to 30% by mass, more preferably 1.5 to 25% by mass, and particularly preferably 2 to 15% by mass.

Hereinafter, the pigment suitable for the present invention will be mainly described.
<Pigment>
An embodiment using a pigment as the colorant is preferred.
As the pigment, either an organic pigment or an inorganic pigment can be used, and as the black pigment, a carbon black pigment or the like is preferable. In general, pigments of three primary colors of black and cyan, magenta, and yellow are used, but other hues such as pigments having hues such as red, green, blue, brown, white, gold, silver, etc. Metal luster pigments, colorless or light extender pigments, and the like can also be used depending on the purpose.

  The organic pigment is not limited in hue, and includes, for example, perylene, perinone, quinacridone, quinacridonequinone, anthraquinone, anthanthrone, benzimidazolone, disazo condensation, disazo, azo, indanthrone, phthalocyanine, triaryl carbo Examples thereof include nium, dioxazine, aminoanthraquinone, diketopyrrolopyrrole, thioindigo, isoindoline, isoindolinone, pyranthrone, isoviolanthrone pigments and mixtures thereof.

  More specifically, for example, C.I. I. Pigment red 190 (C.I. No. 71140), C.I. I. Pigment red 224 (C.I. No. 71127), C.I. I. Perylene pigments such as CI Pigment Violet 29 (C.I. No. 71129); I. Pigment orange 43 (C.I. No. 71105) or C.I. I. Perinone pigments such as CI Pigment Red 194 (C.I. No. 71100); I. Pigment violet 19 (C.I. No. 73900), C.I. I. Pigment violet 42, C.I. I. Pigment red 122 (C.I. No. 73915), C.I. I. Pigment red 192, C.I. I. Pigment red 202 (C.I. No. 73907), C.I. I. Pigment red 207 (C.I. No. 73900, 73906), or C.I. I. Pigment Red 209 (C.I. No. 73905), a quinacridone pigment, C.I. I. Pigment red 206 (C.I. No. 73900/73920), C.I. I. Pigment orange 48 (C.I. No. 73900/73920), or C.I. I. Quinacridone quinone pigments such as CI Pigment Orange 49 (C.I. No. 73900/73920); I. Anthraquinone pigments such as C.I. Pigment Yellow 147 (C.I. No. 60645); I. Anthanthrone pigments such as CI Pigment Red 168 (C.I. No. 59300); I. Pigment brown 25 (C.I. No. 12510), C.I. I. Pigment violet 32 (C.I. No. 12517), C.I. I. Pigment yellow 180 (C.I. No. 21290), C.I. I. Pigment yellow 181 (C.I. No. 11777), C.I. I. Pigment orange 62 (C.I. No. 11775), or C.I. I. Benzimidazolone pigments such as CI Pigment Red 185 (C.I. No. 12516); I. Pigment yellow 93 (C.I. No. 20710), C.I. I. Pigment yellow 94 (C.I. No. 20038), C.I. I. Pigment yellow 95 (C.I. No. 20034), C.I. I. Pigment yellow 128 (C.I. No. 20037), C.I. I. Pigment yellow 166 (C.I. No. 20003), C.I. I. Pigment orange 34 (C.I. No. 21115), C.I. I. Pigment orange 13 (C.I. No. 21110), C.I. I. Pigment orange 31 (C.I. No. 20050), C.I. I. Pigment red 144 (C.I. No. 20735), C.I. I. Pigment red 166 (C.I. No. 20730), C.I. I. Pigment red 220 (C.I. No. 20055), C.I. I. Pigment red 221 (C.I. No. 20065), C.I. I. Pigment red 242 (C.I. No. 20067), C.I. I. Pigment red 248M. I. Pigment red 262, or C.I. I. Disazo condensation pigments such as CI Pigment Brown 23 (C.I. No. 20060),

C. I. Pigment yellow 13 (C.I. No. 21100), C.I. I. Pigment yellow 83 (C.I. No. 21108), or C.I. I. Disazo pigments such as CI Pigment Yellow 188 (C.I. No. 21094); I. Pigment red 187 (C.I. No. 12486), C.I. I. Pigment red 170 (C.I. No. 12475), C.I. I. Pigment yellow 74 (C.I. No. 11714), C.I. I. Pigment yellow 150 (C.I. No. 48545), C.I. I. Pigment red 48 (C.I. No. 15865), C.I. I. Pigment red 53 (C.I. No. 15585), C.I. I. Pigment orange 64 (C.I. No. 12760), or C.I. I. Azo pigments such as C.I. Pigment Red 247 (C.I. No. 15915), C.I. I. Indanthrone pigments such as CI Pigment Blue 60 (C.I. No. 69800); I. Pigment green 7 (C.I. No. 74260), C.I. I. Pigment Green 36 (C.I. No. 74265), Pigment Green 37 (C.I. No. 74255), Pigment Blue 16 (C.I. No. 74100), C.I. I. Phthalocyanine pigments such as CI Pigment Blue 75 (C.I. No. 74160: 2) or 15 (C.I. No. 74160); I. Pigment blue 56 (C.I. No. 42800) or C.I. I. Triarylcarbonium pigments such as C.I. Pigment Blue 61 (C.I. No. 42765: 1); I. Pigment violet 23 (C.I. No. 51319) or C.I. I. Dioxazine pigments such as CI Pigment Violet 37 (C.I. No. 51345); I. Aminoanthraquinone pigments such as C.I. Pigment Red 177 (C.I. No. 65300); I. Pigment red 254 (C.I. No. 56110), C.I. I. Pigment Red 255 (C.I. No. 561050), C.I. I. Pigment red 264, C.I. I. Pigment red 272 (C.I. No. 561150), C.I. I. Pigment orange 71, or C.I. I. Diketopyrrolopyrrole pigments such as C.I. Pigment Orange 73; I. Thioindigo pigments such as CI Pigment Red 88 (C.I. No. 7313), CI Pigment Yellow 139 (C.I. No. 56298), C.I. I. Pigment Orange 66 (C.I. No. 48210) and the like, isoindoline pigments such as C.I. I. Pigment yellow 109 (C.I. No. 56284), or C.I. Pigment Orange 61 (C.I. No. 11295) and the like, isoindolinone pigments such as C.I. I. Pigment Orange 40 (C.I. No. 59700), or C.I. I. Pyranthrone pigments such as CI Pigment Red 216 (C.I. No. 59710), or C.I. I. And isoviolanthrone pigments such as CI Pigment Violet 31 (60010).
As the colorant, two or more kinds of organic pigments or solid solutions of organic pigments can be used in combination.

  In addition, particles having silica, alumina, resin, or the like as a core material and having a dye or pigment fixed on the surface, an insoluble raked product of a dye, a colored emulsion, a colored latex, or the like can also be used as a pigment. Furthermore, resin-coated pigments can also be used. This is called a microcapsule pigment, and commercially available products such as those manufactured by Dainippon Ink and Chemicals and Toyo Ink are available.

  The volume average particle diameter of the pigment particles contained in the liquid is preferably in the range of 10 to 250 nm, more preferably 50 to 200 nm, from the viewpoint of balance between optical density and storage stability. Here, the volume average particle diameter of the pigment particles can be measured by a particle size distribution measuring device such as LB-500 (manufactured by HORIBA).

  The colorant may be used alone or in combination of two or more. Different colorants may be used for each droplet and liquid to be ejected, or the same colorant may be used.

(Other ingredients)
In addition to the components described above, the ink may be used in combination with a storage stabilizer, conductive salts, a solvent capable of adjusting the solubility / dispersibility of the coloring material, and other additives depending on the purpose.

In addition to the above, a set of compounds that react by mixing to form aggregates or thicken can be separately contained in the ink and the inclusion liquid according to the present invention. The set of compounds has a feature of rapidly forming aggregates or rapidly thickening the liquid, thereby more effectively suppressing coalescence between adjacent droplets. Can do.
Here, examples of reaction of a set of compounds include acid / base reaction, hydrogen bond reaction by carboxylic acid / amide group-containing compound, cross-linking reaction represented by boronic acid / diol, and electrostatic interaction by cation / anion. And the like.

  As described above, the recording medium and the ink jet recording apparatus according to the present invention have been described in detail. However, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the gist of the present invention. Changes may be made.

1 is a side view showing a schematic configuration of an example of a recording medium of the present invention. FIG. 2 is a side view showing a schematic configuration of a state after the microcapsules of the recording medium shown in FIG. 1 are ruptured. FIG. 5 is a schematic cross-sectional view showing an example of a recording medium in which an ink liquid is ejected onto a semi-cured liquid film. (A) and (B) are schematic cross-sectional views showing an example of a recording medium in which an ink liquid is ejected onto an uncured liquid film, and (C) is a completely cured state. FIG. 3 is a schematic cross-sectional view showing an example of a recording medium on which an ink liquid is deposited on a liquid film. 1 is a front view showing a schematic configuration of an example of an ink jet recording apparatus of the present invention. FIG. 6 is a top view showing a recording head unit and an ultraviolet irradiation unit of the ink jet recording apparatus shown in FIG. 5. FIG. 5 is a schematic cross-sectional view illustrating an example of a recording medium in which an ink liquid is ejected onto a semi-cured ink liquid. (A) and (B) are schematic cross-sectional views showing an example of a recording medium in which an ink liquid is ejected onto an uncured ink liquid, respectively, and (C) is a completely cured state. FIG. 3 is a schematic cross-sectional view illustrating an example of a recording medium on which ink liquid is ejected onto the ink liquid. (A)-(C) are process drawings which show typically the process of forming an image on a recording medium. It is a front view which shows schematic structure of the other example of the inkjet recording device of this invention. It is a front view which shows schematic structure of the other example of the inkjet recording device of this invention. It is a front view which shows schematic structure of an example of the digital label printing apparatus using the inkjet recording device of this invention. It is a block diagram which shows the control part which controls the digital label printing apparatus shown in FIG. It is a longitudinal cross-sectional view of the recording medium for label printing used for the digital label printing apparatus shown in FIG. It is a schematic sectional drawing which shows the cut | interruption of the recording medium for label printing shown in FIG. It is sectional drawing of the die cutter by which the cutting blade was arrange | positioned on the cylindrical surface, and a perspective view which shows the state of the cut | interruption of the adhesive sheet by which this die cutter was rotated continuously and the cut | interruption was made. It is a perspective view which shows the state of the cut of the adhesive sheet in which the cut was put by the die cutter. It is a front view which shows schematic structure of the other example of the digital label printing apparatus using the inkjet recording device of this invention. It is a block diagram which shows the control part which controls the digital label printing apparatus shown in FIG. It is a front view which shows schematic structure of the other example of the digital label printing apparatus using the inkjet recording device of this invention.

Explanation of symbols

2 Base material 4 Microcapsule 6 Microcapsule coating layer (capsule layer)
8 Liquid Film 10, 80, 90 Inkjet Recording Device 12 Conveying Unit 13 Capsule Breaking Unit 15 Supporting Unit 16 Image Recording Unit 18, 91 Image Fixing Unit 19 Curing Promoting Unit 20 Control Unit 22 Input Device 30 Supply Roll 34 Conveying Roll Pair 36 Recovery Roll 38 Main body surface plate 38a, 38b, 42c Opening 40 Head surface plate 40a, 42a Plate portion 40b, 42b Foot portion 42 Irradiation portion support 44 Buffer member 46 Recording head unit 48W, 48C, 48M, 48Y, 48K Recording head 50 Ink Tank 52 Ultraviolet irradiation unit 54 Ultraviolet irradiation unit 56 Platen 60, 84 Application roller 62 Drive unit 64 Storage tray 66, 86 Blade 68 Positioning unit 70, 72 Positioning roller 74a, 74b, 74c Bearing 88 Storage unit 100 Label printer P Recorded Medium

Claims (7)

A substrate and a plurality of microcapsules applied to the surface of the substrate;
The microcapsule is a recording medium in which an active energy ray-curable liquid is filled.   The recording medium according to claim 1, wherein the liquid filled in the microcapsule is a liquid containing a radical polymerizable composition.   3. The recording target according to claim 1, wherein after the plurality of microcapsules are ruptured, the filled liquid forms a liquid amount that forms a liquid film having a thickness of 1 μm or more and 20 μm or less on the substrate. Medium.   The plurality of microcapsules contain an amount of liquid that, after being ruptured, forms a liquid film having a thickness of 1 μm or more and 3 μm or less on the substrate. Recording medium. An inkjet recording apparatus for forming an image on a recording medium according to claim 1,
Microcapsule breaking means for rupturing the plurality of microcapsules of the recording medium and forming a liquid film with the liquid contained in the plurality of microcapsules on the substrate;
Image forming means for forming an image on the recording medium in which the liquid film is formed on the substrate by ejecting ink that contains at least a colorant and is cured by irradiation with active energy rays; ,
An inkjet recording apparatus comprising: an active energy ray irradiating unit that irradiates an active energy ray on a recording medium on which the image is formed and cures the image.   The inkjet recording apparatus according to claim 5, further comprising a semi-curing unit that irradiates the liquid film of the recording medium with active energy rays to semi-cure the liquid film. The image forming unit includes a plurality of ink jet heads arranged in a conveyance direction of the recording medium,
Further, the ink that is disposed between the inkjet heads in the transport direction, is ejected from the inkjet head on the upstream side in the transport direction, and forms the image on the recording medium is irradiated with active energy rays. The ink jet recording apparatus according to claim 5, further comprising ink semi-curing means for semi-curing the ink.

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