JP2008087274A - Inkjet recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an effective inkjet recording apparatus which can easily suppress the curing of ink only by moving a head unit upward/downward and stably eject an inkjet for a long period of time. <P>SOLUTION: This inkjet recording apparatus comprises: the head unit for collectively fixing a plurality of inkjet heads for ejecting an energy-curing functional material toward a recording medium from a nozzle on the basis of an image signal; a recording medium carrying means for carrying the recording medium to a position to face the inkjet head; an energy irradiation device which is present in a position close to the inkjet head in the state of facing the recording medium; and a supply passage which supplies the functional material to the inkjet head. A light shielding member for shielding the energy is fixed at least on the energy irradiation device-side of the head unit. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ink jet apparatus that forms an image by ejecting a liquid functional material onto a recording medium using an ink jet head.

An inkjet apparatus that forms an image by discharging a functional material (hereinafter also referred to as ink) that is cured by energy such as ultraviolet rays or electron beams onto a recording medium using an inkjet head and curing the functional material by energy irradiation. It is environmentally friendly, can be recorded on various recording media at high speed, and can produce high-definition images that are resistant to bleeding. In particular, an apparatus using ultraviolet curable ink has been developed from the viewpoint of easy handling of a light source and compactness.
However, since the ultraviolet curable ink has a feature that the curing is inhibited by the presence of oxygen and moisture by the polymerization mechanism, the curability improves as the curing atmosphere and the amount of oxygen and moisture in the ink decrease. For this reason, the ink is deaerated to improve the curability, and as a result, the productivity is improved. However, improvement in curability leads to a decrease in ink stability. In particular, ink curing is likely to occur due to leakage light or reflected light from the ultraviolet light source on the lower surface of the inkjet head, and the dissolved oxygen amount of the ink cannot be reduced to a certain extent as disclosed in JP-A-2004-196936. It was. Therefore, in Japanese Patent Application Laid-Open Nos. 2004-338264 and 2004-167968, the reflection from each member is controlled to reduce the leakage light. However, the irregular reflection light from the recording medium cannot be prevented by any means. It was. In particular, in a full-line type inkjet apparatus in which the recording medium always exists below the head, it is very difficult to suppress reflection from the recording medium.
Moreover, what controls leak light with the optical trap in patent document 1 was also known.
JP 2004-167968 A

However, the leakage light control by the light trap of Patent Document 1 also has a problem that the ink is spread before curing because the gap between the light source and the head is widened, and the image quality is deteriorated. In addition, the apparatus described in Patent Document 1 has a drawback that the apparatus becomes large. Furthermore, when maintaining the head unit, it is necessary to remove the optical trap one by one to facilitate maintenance, and to reattach it after the maintenance is completed, and this operation requires precise adjustment of the distance from the recording medium. So a skilled worker was required.
Thus, conventionally, there has been no effective means for suppressing ink curing by a simple method and stably performing ink jet ejection for a long time.

  Accordingly, the present invention has been made to solve these problems, and provides an effective and easy-to-maintain ink jet recording apparatus that suppresses ink curing with a simple means and stably ejects ink for a long time. The purpose is that.

In order to achieve the above object, an invention according to claim 1 relates to an ink jet apparatus, wherein a plurality of ink jet heads for discharging energy curable functional material from a nozzle toward a recording medium based on an image signal are fixed together. A unit, a recording medium transporting means for transporting the recording medium to a position facing the ink jet head, an energy irradiation device located at a position facing the recording medium and close to the ink jet head, and the ink jet head An ink jet recording apparatus having a supply path for supplying a conductive material is characterized in that a light shielding member for shielding the energy is fixed to at least the energy irradiation apparatus side of the head unit.
According to a second aspect of the present invention, there is provided an ink jet apparatus, comprising: a head unit that collectively fixes a plurality of ink jet heads that eject energy curable functional materials from nozzles toward a recording medium based on an image signal; and a recording medium. A recording medium conveying unit that conveys the ink jet head to a position facing the ink jet head, an energy irradiation device that is located near the ink jet head so as to face the recording medium, and a supply path for supplying a functional material to the ink jet head In the ink jet recording apparatus, a light shielding member that shields the energy is fixed to the recording medium conveying unit.

According to a third aspect of the present invention, in the ink jet recording apparatus according to the first aspect, the distance between the lower surface of the light shielding member and the recording medium is not more than the distance between the lower surface of the ink jet head and the recording medium.
According to a fourth aspect of the present invention, in the ink jet recording apparatus according to any one of the first to third aspects, an interval adjusting mechanism capable of adjusting an interval between the light shielding member and the recording medium is provided. .
According to a fifth aspect of the present invention, in the ink jet recording apparatus according to the fourth aspect, the spacing adjusting mechanism also serves as a spacing adjusting mechanism between the recording media on the lower surface of the head of the inkjet head.
The invention according to claim 6 is the ink jet recording apparatus according to any one of claims 1 to 5, wherein the ink jet recording apparatus communicates with the supply path and stores the liquid functional material; It has the vacuum deaeration mechanism provided in an inkjet head or the said supply path, or the said storage device, It is characterized by the above-mentioned.
A seventh aspect of the present invention is the ink jet recording apparatus according to any one of the first to sixth aspects, wherein the ink jet head unit is a full line type.

  With the above configuration, the light shielding member is also moved up and down simply by moving the head unit or the recording medium conveying means up and down, so that maintenance is facilitated, and further, the ink can be suppressed as it approaches the recording medium as much as possible, Therefore, an effective ink jet recording apparatus that stably ejects ink for a long time can be obtained.

Hereinafter, the present invention will be described in detail based on examples.
FIG. 1 is a configuration diagram of an active energy curable ink jet recording apparatus targeted by the present invention. The active energy curable ink jet recording apparatus uses, as the active energy curable ink, a UV curable ink that is cured by irradiation with ultraviolet rays.

  In FIG. 1, in the case 22 of the active energy curable ink jet recording apparatus 10, the recording medium S wound around the delivery-side roll 44 a is extended by the transport roller 130 and passes through the flexible light shielding door 24. Are transported into the housing 22. The transported recording medium S is sent out from a flexible light shielding door 26 disposed on the opposite side of the casing 22 and is taken up by a take-up roll 44b.

  The recording medium S carried into the housing 22 is held by the conveyance holding roller 45 a and is sent out onto the plurality of support conveyance rollers 46. Further, the recording medium S is held by a conveyance holding roller 45 b disposed on the downstream side of the support conveyance roller 46, scanned and conveyed on the support conveyance roller 46, and sent out from the light shielding door 26. On the support conveyance roller 46, the image recording unit 50 is arranged at a position opposite to the recording medium S. In this way, the scanning conveyance unit 40 is formed by the delivery side roll 44 a, the winding side roll 44 b, the conveyance roller 130, the conveyance holding rollers 45 a and 45 b, and the support conveyance roller 46.

  The image recording unit 50 performs inkjet image recording and active energy (ultraviolet light in this embodiment) irradiation fixing on the recording medium S being scanned and conveyed on the support conveyance roller 46. An ink storage unit that supplies and stores ink to the image recording unit 50 through a supply path (not shown) is provided in the housing 22.

  In the image recording unit 50, the inkjet head 51 of the head unit 52 is provided with the tip of the ink discharge unit facing the conveyance surface of the support conveyance roller 46 at the image recording position, and the head unit 52 is arranged in the width direction of the recording medium S. This is a full-line head with an array of lengths, and a piezo-type head. Further, the head unit 52 ejects ink curable by active energy toward the recording medium S. The head unit 52 is connected to a head driver which is an ink jet head driving device, and controls the ejection amount of each ink color. A coating mechanism other than inkjet or a surface treatment mechanism such as corona treatment may be provided around the image recording unit 50.

  An active energy irradiation unit 56 is disposed downstream of the head unit 51. A set of the head unit 51 and the active energy irradiation unit 56 is held and arranged on the head holder in the downstream direction by the number of inks (six sets in the drawing) to form the head unit 52. The image recording unit 50 is connected to an ink supply unit (not shown) for supplying ink. In FIG. 1, the active energy irradiation units 56 are provided by the number of the head units 52, but it is not necessary to provide irradiation units for each inkjet h-ed, and an arbitrary number may be provided. In addition, the type, light amount, and spectrum of each active energy irradiation unit may be different.

  The plurality of supporting and conveying rollers 46 are supported by a pressing unit 47, and the supporting and conveying roller 46 and the pressing unit 47 constitute a recording medium conveying mechanism. The pressing means 47 can be moved in a direction approaching or separating from the head unit 52 by a vertical movement mechanism (not shown).

Next, the present invention will be described based on the vicinity of the head unit.
2A and 2B are views in the vicinity of the head unit according to the first embodiment, where FIG. 2A is a schematic front view, and FIG. 2B is a schematic side view.
In FIG. 2, 11-1 and 11-2 are head units, 12-1 and 12-2 are light sources, 13 is a recording medium conveyance mechanism, and is constituted by the support conveyance roller 46 and the pressing means 47 or the platen of FIG. (Here it is shown in the example of a platen). 14-1 and 14-2 are head unit up-and-down mechanisms, S is a recording medium, and arrow A is a recording medium conveyance direction. In 14-1 and 14-2, t1 can be controlled manually or automatically by an interval measurement function (not shown). 19-1 and 19-2 are light shielding members according to the first embodiment, 19-1a and 19-2a are on the downstream (light source) side of the head unit, and 19-1b and 19-2b are head units. The head unit 11 is fixed integrally with the upstream side. t1 is the distance between the lower end of the head unit and the recording medium, t2 is the distance between the lower end of the light shielding member and the recording medium, and t1> = t2 according to the present invention.

By adjusting the positional relationship among the UV light source, the recording medium, and the head unit, it is possible to reduce the leakage light intensity to about one millionth. For example, a smaller interval t1 between the head unit and the recording medium is advantageous for preventing leakage light, but it is difficult to adjust it to a certain extent from the viewpoint of straight discharge performance and avoidance of contact with the recording medium S. . Further, it is difficult to adjust the distance between the light source unit and the recording medium S to some extent from the viewpoint of ultraviolet intensity and heat. Although it is preferable that the distance between the head unit and the light source is large, the apparatus becomes large and the ejected ink moves and is likely to be deformed.
From this point of view, a light shielding member 19 is provided between the light source and the head unit 11, and the light shielding member 19 is attached to the head unit 11 in the first embodiment, and the light shielding member 19 and the recording medium It is characterized in that it protrudes further from the lower end of the head unit 11 so that the interval t2 with S is smaller than the interval t1 between the head unit 11 and the recording medium S.
The head unit 11 itself has been adjusted in the vertical direction using conventional head unit vertical mechanisms 14-1 and 14-2. The head unit vertical mechanism 14-1 and 14-2 is used to adjust the head. By simply adjusting the unit, the light shielding member is automatically adjusted to an optimum interval with respect to the recording medium, and the apparatus can be simplified and the operation and maintenance can be simplified.

The shape of the light shielding member is not particularly limited, but a plate shape as shown in the drawing is particularly preferable because it can be easily integrated with the head unit. Further, it is preferable that the light shielding member has a structure that holds at least an end portion of the recording medium. The light shielding member is preferably attached to the light source side of the head unit (downstream side in the recording medium conveyance direction), but light from the light source upstream in the conveyance direction may leak and reach the light source. It is better to install on both sides of the downstream. It is more desirable to be on the side of the upstream and downstream surfaces.
Further, it is desirable that the light shielding member and the entire recording apparatus are coated with a paint that hardly reflects UV.

Thus, according to the first embodiment, since the light shielding member is integrally fixed to the head unit, the diffracted light that travels around the light shielding member reaches the head because the light shielding member approaches the head unit. It becomes difficult to suppress the curing of the ink, and therefore, an effective ink jet recording apparatus that stably performs ink jet ejection for a long time can be obtained.
Further, since the light shielding member is also moved up and down simply by moving the head unit up and down, maintenance is facilitated.

3A and 3B are views in the vicinity of the head unit according to the second embodiment. FIG. 3A is a schematic front view, and FIG. 3B is a schematic side view.
In FIG. 3, 11-1 and 11-2 are head units, 12-1 and 12-2 are light sources, and 13 is a recording medium conveyance mechanism. Here, an example of a platen is shown. S is the recording medium, and arrow A is the recording medium conveyance direction. Reference numerals 18-1 and 18-2 denote light shielding members according to the second embodiment, and 17 denotes a coupling member that integrally couples the light shielding member 18 and the platen 13. The light shielding members 18-1a and 18-2a are integrated with the platen so that the light shielding members 18-1a and 18-2a are positioned on the downstream (light source) side of the head unit 11, and 18-1b and 18-2b are positioned on the upstream side of the head unit 11. It is fixed by a coupling member 17. t1 is the distance between the lower end of the head unit 11 and the recording medium, t2 is the distance between the lower end of the light shielding member and the recording medium, and t1> t2 according to the present invention.

In the first embodiment (FIG. 2), the position adjustment between the light shielding member and the recording medium is performed by using the head unit vertical mechanism 14 that adjusts the position of the head unit 11 and the recording medium S. The second embodiment (FIG. 3) is characterized in that the platen vertical mechanism 16 that adjusts the position of the head unit 11 and the recording medium S is also used.
As described above, the light shielding member is automatically adjusted to the optimum interval with respect to the recording medium only by adjusting the vertical position of the platen as in the past by using the conventional platen vertical mechanism 16. Simplification of position, simplification of position adjustment, and ease of operation and maintenance can be obtained.

The shape of the light shielding member is not particularly limited, but a plate shape as shown in the drawing is particularly preferable because it can be easily integrated with the head unit. Further, it is preferable that the light shielding member has a structure that holds at least an end portion of the recording medium. The light shielding member is preferably attached to the light source side of the head unit (downstream in the recording medium conveyance direction). However, since the light from the light source upstream in the conveyance direction may also leak and reach, the light shielding member is as shown in FIG. It is preferable that the head unit is mounted so as to be located on both upstream and downstream sides. It is more desirable to be on the side of the upstream and downstream surfaces.
Further, it is desirable that the light shielding member and the entire recording apparatus are coated with a paint that hardly reflects UV.

Thus, according to the second embodiment, since the light shielding member is integrally fixed to the recording medium conveying means (platen), the light shielding member can be stably brought close to the head unit. This makes it possible to make it difficult for the diffracted light that travels around the light shielding member to reach the head and to suppress the curing of the ink. Therefore, an effective ink jet recording apparatus that stably performs ink jet ejection for a long time can be obtained.
Further, since the light shielding member is also moved up and down simply by moving the platen up and down, maintenance is facilitated.

表１では、ヘッドユニットと被記録媒体の間隔ｔ１が１ｍｍである時の比較例及び実施例を遮光部材と被記録媒体の距離を変えて示している。また、その他のパラメータは、ＵＶ光源強度が２０００ｍＷ／ｃｍ²で、ヘッドと光源間距離は５０ｍｍである。
光強度の測定にはＯｃｅａｎ Ｏｐｔｉｃｓ社製のＵＳＢ２０００を使用した。測定波長は３２０ｎｍ〜３９０ｎｍである。また、ＵＶ光源にはＩｎｔｅｇｒａｔｉｏｎ Ｔｅｃｈｎｏｌｏｇｙ社のＶ−ｚｅｒｏ ８５を使用した。測定時にはシャッターをオープンとしている。また、インクは例えば特表２００４−５２６８０号の実施例記載のインクを使用した。インクはインク供給系に備えられた真空脱気装置によって、０．０５ atm以下で高真空脱気されている。このため、泡の成長による不吐出は完全に抑制されるが、酸素阻害がないためにヘッド表面で非常に硬化しやすくなっている。
連続描画可能時間は東芝テック社製ヘッドＣＡ３を、４．８ ｋＨｚで連続吐出駆動した時、吐出不良が発生するまでの時間である。勿論ＵＶ光源やインクやインクジェットヘッドは、上記に限定されるものではない。
漏れ光は全くないことが最も好ましいが、しかしながら漏れ光強度は１μＷ／ｃｍ²以下であっても好ましい。 Table 1 is a table showing the effects of the present invention.

Table 1 shows a comparative example and an example in which the distance t1 between the head unit and the recording medium is 1 mm while changing the distance between the light shielding member and the recording medium. Other parameters are that the UV light source intensity is 2000 mW / cm ² and the distance between the head and the light source is 50 mm.
USB2000 manufactured by Ocean Optics was used for measurement of light intensity. The measurement wavelength is 320 nm to 390 nm. Moreover, V-zero 85 of Integration Technology was used for the UV light source. The shutter is open during measurement. For example, the ink described in the examples of JP-T-2004-52680 was used. The ink is degassed at a high vacuum of 0.05 atm or less by a vacuum degassing device provided in the ink supply system. For this reason, non-ejection due to the growth of bubbles is completely suppressed, but since there is no oxygen inhibition, it is very easy to cure on the head surface.
The continuous drawing possible time is the time until a discharge failure occurs when the head CA3 manufactured by TOSHIBA TEC Corporation is continuously discharged at 4.8 kHz. Of course, the UV light source, ink, and inkjet head are not limited to the above.
Most preferably, there is no leakage light, however, it is preferable that the leakage light intensity is 1 μW / cm ² or less.

As can be seen from Table 1, in Comparative Example 1, when the distance t2 between the light shielding member and the recording medium is as large as 5 mm, the leakage light intensity is 100 μW / cm ² , and the ink is cured because the leakage light intensity by the UV light source is high. The “continuous drawing possible time”, which is a pass / fail judgment element, was as short as 0.6 hours, and evaluation was impossible (XX).
In Comparative Example 2, the distance t2 between the light shielding member and the recording medium was 2 mm, which was considerably smaller than that of Comparative Example 1, but the leakage light intensity was 20 μW / cm ^2. As a result, the “continuous drawing possible time” was Although it was 1.6 hours, it was still short and evaluation was impossible (x).
In Comparative Example 3, when the interval t2 between the light shielding member and the recording medium is 1 mm, the leakage light intensity is 1.5 μW / cm ² , the continuous drawing time is 4.2 hours, and the evaluation is within the allowable range (Δ). Met.

On the other hand, in Example 1, when the distance t2 between the light shielding member and the recording medium is 0.9 mm, the leakage light intensity is 0.8 μW / cm ² , and the “continuous drawing possible time” as the pass / fail judgment element is It became 6.6 hours and the evaluation was good (◯).
Further, in Example 2, when the interval t2 is shortened to 0.8 mm, the leakage light intensity becomes 0.5 μW / cm ² , and the “continuous drawing possible time” as the pass / fail judgment element becomes as long as 8.0 hours. Became good (○).
As described above, in Example 1, the light leakage is suppressed by narrowing the distance between the light shielding member and the recording medium, and the continuous drawing possible time is 6 hours or more. By further reducing the distance between the light shielding member and the recording medium as in the second embodiment, a continuous drawing possible time of 8 hours or more is achieved.

  FIG. 4 is a conceptual diagram illustrating an ink supply system that supplies ink to the ink jet head in the ink jet recording apparatus of FIG. 1. In FIG. 4, 50 is an image recording unit, 51 is an inkjet head, 52 is a head unit, 70 is an ink supply unit, 72A and 72B are ink tanks, 74 is a pump provided with a filter, 75 is a pipe that is an air supply mechanism, 76 is a deaeration (deoxygenation) device, 78 is a vacuum pump, 80 is an ink supply path, 80a is a branch path, 84 is an exposure valve, and L is ink.

The ink supply operation of this ink jet recording apparatus is as follows.
At the time of image formation, the exposure valve 84 is closed and the deaeration mechanism 82 is operated to perform deaeration from the ink L in the ink supply path 80 and supply it to the inkjet head 51. The degassed ink L is ejected from the inkjet head 51 based on the control of the head driver 54 (FIG. 1) and landed on the recording medium S (FIG. 1), and ultraviolet rays are emitted from the ultraviolet irradiation unit 56 (FIG. 1). Irradiation forms an image.
Since the ink L that has landed on the recording medium S has been degassed, the generation of bubbles in the inkjet head 51 is reduced, and the ejection failure due to the bubbles is improved.
Since the ink is hard to be cured by degassing the ink L in this way, a vacuum degassing mechanism is additionally employed in the present invention, and this is provided in the ink jet head, the supply path or the reservoir, and the image By vacuuming the ink L with a vacuum degassing mechanism at the time of formation, the air (oxygen, etc.) in the ink is degassed, making it difficult for the ink to harden even under slight leakage light, and to allow continuous drawing time It can be made longer.

  Here, the “active energy” referred to in the present invention is not particularly limited as long as it can impart energy capable of generating a starting species in the ink composition by the irradiation, and broadly includes α rays, Including gamma rays, X-rays, ultraviolet rays, visible rays, electron beams, and the like. Among these, from the viewpoints of curing sensitivity and device availability, ultraviolet rays and electron beams are preferable, and ultraviolet rays are particularly preferable. Therefore, the ink composition of the present invention is preferably an ink composition that can be cured by irradiation with ultraviolet rays.

In the inkjet recording apparatus of the present invention, the peak wavelength of the active energy depends on the absorption characteristics of the sensitizing dye in the ink composition, but is, for example, 200 to 600 nm, preferably 300 to 450 nm, and more preferably 350 to It is suitable that it is 450 nm. In addition, the (a) electron transfer type initiation system of the ink composition of the present invention has sufficient sensitivity even with low output active energy. Accordingly, the output of active energy is, for example, 2,000 mJ / cm 2 or less, preferably 10 to 2,000 mJ / cm 2, more preferably 20 to 1,000 mJ / cm 2, and still more preferably 50 to 800 mJ / cm 2. The irradiation energy is appropriate. Further, it is appropriate that the active energy is irradiated at an exposure surface illuminance (maximum illuminance on the surface of the recording medium) of, for example, 10 to 2,000 mW / cm2, preferably 20 to 1,000 mW / cm2.
In particular, in the ink jet recording apparatus of the present invention, irradiation with active energy generates ultraviolet rays having an emission wavelength peak of 390 to 420 nm and a maximum illuminance on the recording medium surface of 10 to 1,000 mW / cm <2>. Irradiation from a light emitting diode is preferred.

In the ink jet recording apparatus of the present invention, it is appropriate that the active energy is applied to the ink composition ejected on the recording medium, for example, for 0.01 to 120 seconds, preferably 0.1 to 90 seconds. It is.
Furthermore, in the ink jet recording apparatus of the present invention, the ink composition is heated to a constant temperature, and the time from the landing of the ink composition on the recording medium to the irradiation of the active energy is 0.01 to 0.5 seconds. Preferably, it is 0.02 to 0.3 seconds, and more preferably 0.03 to 0.15 seconds. Thus, by controlling the time from the landing of the ink composition to the recording medium to the irradiation of the active energy to an extremely short time, it is possible to prevent the landed ink composition from bleeding before curing. .

  In order to obtain a color image using the ink jet recording apparatus of the present invention, it is preferable to superimpose in order from the color with the lowest brightness. By overlapping in this way, the active energy can easily reach the lower ink, and good curing sensitivity, reduction of residual monomers, reduction of odor, and improvement of adhesion can be expected. In addition, although irradiation with active energy can be performed by injecting all the colors and exposing them together, exposure for each color is preferable from the viewpoint of promoting curing.

  Further, as described above, since the active energy curable ink such as the ink composition of the present invention desirably has a constant temperature for the discharged ink composition, from the ink supply tank to the inkjet head portion, It is preferable to perform temperature control by heat insulation and heating. Further, the head unit to be heated is preferably thermally shielded or insulated so that the apparatus main body is not affected by the temperature from the air. In order to shorten the printer start-up time required for heating or to reduce the loss of heat energy, it is preferable to insulate from other parts and reduce the heat capacity of the entire heating unit.

  Further, mercury lamps and gas / solid lasers are mainly used as active energy sources, and mercury lamps and metal halide lamps are widely known as ultraviolet light curable ink jets. Furthermore, replacement with a GaN-based semiconductor ultraviolet light emitting device is very useful industrially and environmentally. Furthermore, LED (UV-LED) and LD (UV-LD) are small, have a long lifetime, high efficiency, and low cost, and are expected as radiation sources for active energy curable ink jets.

  Further, as described above, a light emitting diode (LED) and a laser diode (LD) can be used as the active energy source. In particular, when an ultraviolet light source is required, an ultraviolet LED and an ultraviolet LD can be used. For example, Nichia Corporation has introduced a purple LED whose main emission spectrum has a wavelength between 365 nm and 420 nm. Furthermore, when shorter wavelengths are required, US Pat. No. 6,084,250 discloses an LED that can emit active energy centered between 300 nm and 370 nm. Other ultraviolet LEDs are also available and can radiate radiation in different ultraviolet bands. A particularly preferable active energy source in the present invention is a UV-LED, and a UV-LED having a peak wavelength of 350 to 420 nm is particularly preferable.

[Recording medium]
The recording medium to which the ink composition of the present invention can be applied is not particularly limited, and various kinds of non-absorbing resin materials used for ordinary non-coated paper, coated paper, so-called soft packaging, or the like. A resin film formed into a film can be used, and examples of various plastic films include PET film, OPS film, OPP film, ONy film, PVC film, PE film, TAC film, PP film, and the like. . In addition, examples of the plastic that can be used as a recording medium material include polycarbonate, acrylic resin, ABS, polyacetal, PVA, and rubbers. Metals and glasses can also be used as the recording medium.
In the ink composition of the present invention, when a material with low thermal shrinkage at the time of curing is selected, the adhesive property between the cured ink composition and the recording medium is excellent. Films that tend to curl and deform, such as heat-shrinkable PET film, OPS film, OPP film, ONy film, PVC film, etc., have the advantage that a high-definition image can be formed.

Below, each component used for the ink composition which can be used by this invention is demonstrated sequentially.
[Ink composition]
The ink composition used in the present invention is an ink composition that can be cured by irradiation with active energy, and examples thereof include a cationic polymerization ink composition, a radical polymerization ink composition, and a water-based ink composition. These compositions will be described in detail below.

(Cationically-polymerized ink composition)
The cationic polymerization-type ink composition contains (a) a cationic polymerizable compound, (b) a compound that generates an acid upon irradiation with active energy, and (c) a colorant. If desired, it may further contain an ultraviolet absorber, a sensitizer, an antioxidant, an antifading agent, a conductive salt, a solvent, a polymer compound, a surfactant and the like.
Hereafter, each component used for a cationic polymerization type ink composition is demonstrated one by one.

[(A) Cationic polymerizable compound]
The (a) cationic polymerizable compound used in the present invention is not particularly limited as long as it is a compound that causes a polymerization reaction by an acid generated from a compound that generates an acid by irradiation of active energy (b) described later and cures. Various known cationic polymerizable monomers known as photo cationic polymerizable monomers can be used. Examples of the cationic polymerizable monomer include various publications such as JP-A-6-9714, JP-A-2001-31892, JP-A-2001-40068, JP-A-2001-55507, JP-A-2001-310938, JP-A-2001-310937, and JP-A-2001-220526. Examples thereof include epoxy compounds, vinyl ether compounds, oxetane compounds and the like.

Examples of the epoxy compound include aromatic epoxides, alicyclic epoxides, and aliphatic epoxides.
Aromatic epoxides include di- or polyglycidyl ethers produced by the reaction of polyphenols having at least one aromatic nucleus or their alkylene oxide adducts and epichlorohydrin, such as bisphenol A or its alkylene oxides. Examples thereof include di- or polyglycidyl ethers of adducts, di- or polyglycidyl ethers of hydrogenated bisphenol A or its alkylene oxide adducts, and novolak-type epoxy resins. Here, examples of the alkylene oxide include ethylene oxide and propylene oxide.

  As the alicyclic epoxide, cyclohexene oxide obtained by epoxidizing a compound having at least one cycloalkane ring such as cyclohexene or cyclopentene ring with a suitable oxidizing agent such as hydrogen peroxide or peracid. Or a cyclopentene oxide containing compound is mentioned preferably.

  Examples of the aliphatic epoxide include dihydric polyglycidyl ethers of aliphatic polyhydric alcohols or alkylene oxide adducts thereof. Typical examples include diglycidyl ether of ethylene glycol, diglycidyl ether of propylene glycol or diglycidyl ether of alkylene glycol such as diglycidyl ether of 1,6-hexanediol, di- or tri- or di- or tri-glycol or adducts thereof. Polyglycidyl ether of polyhydric alcohol such as glycidyl ether, diglycidyl ether of polyethylene glycol or alkylene oxide adduct thereof, diglycidyl ether of polyalkylene glycol represented by diglycidyl ether of polypropylene glycol or alkylene oxide adduct thereof, etc. Can be mentioned. Here, examples of the alkylene oxide include ethylene oxide and propylene oxide.

The epoxy compound may be monofunctional or polyfunctional.
Examples of monofunctional epoxy compounds that can be used in the present invention include, for example, phenyl glycidyl ether, p-tert-butylphenyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, allyl glycidyl ether, 1,2-butylene oxide, 1,3-butadiene monooxide, 1,2-epoxydodecane, epichlorohydrin, 1,2-epoxydecane, styrene oxide, cyclohexene oxide, 3-methacryloyloxymethylcyclohexene oxide, 3-acryloyloxymethylcyclohexene oxide, 3 -Vinylcyclohexene oxide etc. are mentioned.

  Examples of polyfunctional epoxy compounds include, for example, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, brominated bisphenol F diglycidyl ether, and brominated bisphenol. S diglycidyl ether, epoxy novolac resin, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether, 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxy 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-meta-dioxane, bis (3,4-epoxycyclo) Xylmethyl) adipate, vinylcyclohexene oxide, 4-vinylepoxycyclohexane, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 3,4-epoxy-6-methylcyclohexyl-3 ′, 4′-epoxy-6 '-Methylcyclohexanecarboxylate, methylenebis (3,4-epoxycyclohexane), dicyclopentadiene diepoxide, ethylene glycol di (3,4-epoxycyclohexylmethyl) ether, ethylenebis (3,4-epoxycyclohexanecarboxylate) , Epoxyhexahydrophthalate dioctyl, epoxyhexahydrophthalate di-2-ethylhexyl, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether Glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ethers, 1,1,3-tetradecadiene dioxide, limonene dioxide, 1,2,7,8- Examples include diepoxyoctane and 1,2,5,6-diepoxycyclooctane.

  Among these epoxy compounds, aromatic epoxides and alicyclic epoxides are preferable from the viewpoint of excellent curing speed, and alicyclic epoxides are particularly preferable.

  Examples of the vinyl ether compound include ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, propylene glycol divinyl ether, dipropylene glycol divinyl ether, butanediol divinyl ether, hexanediol divinyl ether, cyclohexanedimethanol divinyl ether, Di- or trivinyl ether compounds such as methylolpropane trivinyl ether, ethyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, octadecyl vinyl ether, cyclohexyl vinyl ether, hydroxybutyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexane dimethanol monovinyl ether, n-propyl Pills vinyl ether, isopropyl vinyl ether, isopropenyl ether -O- propylene carbonate, dodecyl vinyl ether, diethylene glycol monovinyl ether, and octadecyl vinyl ether.

The vinyl ether compound may be monofunctional or polyfunctional.
Specifically, examples of monofunctional vinyl ethers include, for example, 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 , Methoxypolyethyleneglycol 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, Examples include 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, and bisphenol F. Divinyl ethers such as alkylene oxide divinyl ether; trimethylolethane trivinyl ether, trimethylolpropane trivinyl ether, ditrimethylolpropane tetravinyl ether, glycerin trivinyl ether, pentaerythritol tetravinyl ether, dipentaerythritol pentavinyl ether, dipentaerythritol Hexavinyl 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 addition Examples thereof include polyfunctional vinyl ethers such as pentaerythritol tetravinyl ether, ethylene oxide-added dipentaerythritol hexavinyl ether, and propylene oxide-added dipentaerythritol hexavinyl ether.

  As the vinyl ether compound, a di- or trivinyl ether compound is preferable from the viewpoints of curability, adhesion to a recording medium, surface hardness of the formed image, and the like, and a divinyl ether compound is particularly preferable.

The oxetane compound in the present invention refers to a compound having an oxetane ring, and a known oxetane compound can be arbitrarily selected and used as described in JP-A Nos. 2001-220526, 2001-310937, and 2003-341217. .
The compound having an oxetane ring that can be used in the ink composition of the present invention is preferably a compound having 1 to 4 oxetane rings in the structure. By using such a compound, it becomes easy to maintain the viscosity of the ink composition within a good handling range, and obtain high adhesion between the cured ink composition and the recording medium. Can do.

The compound having such an oxetane ring is described in detail in the above-mentioned JP-A No. 2003-341217, paragraph numbers [0021] to [0084], and the compounds described herein can be suitably used in the present invention.
Among the oxetane compounds used in the present invention, it is preferable to use a compound having one oxetane ring from the viewpoint of the viscosity and tackiness of the ink composition.

In the ink composition of the present invention, these cationic polymerizable compounds may be used alone or in combination of two or more, but from the viewpoint of effectively suppressing shrinkage during ink curing. Is preferably a combination of at least one compound selected from an oxetane compound and an epoxy compound and a vinyl ether compound.
The content of the (a) cationic polymerizable compound in the ink composition is suitably 10 to 95% by mass, preferably 30 to 90% by mass, and more preferably 50 to 85%, based on the total solid content of the composition. It is the range of mass%.

[(B) Compound that generates acid upon irradiation with active energy]
The ink composition of the present invention contains a compound that generates an acid upon irradiation with active energy (hereinafter, appropriately referred to as “photoacid generator”).
Examples of the photoacid generator that can be used in the present invention include photoinitiators for photocationic polymerization, photoinitiators for photoradical polymerization, photodecolorants for dyes, photochromic agents, and light used for microresists. (400-200 nm ultraviolet rays, far ultraviolet rays, particularly preferably g-line, h-line, i-line, KrF excimer laser beam), ArF excimer laser beam, electron beam, X-ray, molecular beam, ion beam, etc. A compound capable of generating can be appropriately selected and used.

  As such a photoacid generator, for example, an onium salt such as a diazonium salt, an ammonium salt, a phosphonium salt, an iodonium salt, a sulfonium salt, a selenonium salt, an arsonium salt, which decomposes upon irradiation with active energy to generate an acid, Organic halogen compounds, organic metal / organic halides, photoacid generators having an o-nitrobenzyl type protecting group, compounds that generate photosulfonic acids by photolysis, such as iminosulfonates, disulfone compounds, diazoketo A sulfone and a diazo disulfone compound can be mentioned.

  As the photoacid generator, oxazole derivatives and s-triazine derivatives described in JP-A No. 2002-122994, paragraphs [0029] to [0030] are also preferably used. Furthermore, onium salt compounds and sulfonate compounds exemplified in JP-A No. 2002-122994, paragraph numbers [0037] to [0063] can also be suitably used as the photoacid generator in the present invention.

(B) A photo-acid generator can be used individually by 1 type or in combination of 2 or more types.
The content of the (b) photoacid generator in the ink composition is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, and still more preferably in terms of the total solid content of the ink composition. Is 1-7 mass%.

[(C) Colorant]
The ink composition of the present invention can form a visible image by adding a colorant. For example, when forming an image area of a lithographic printing plate, it is not always necessary to add it, but it is also preferable to use a colorant from the viewpoint of plate inspection of the obtained lithographic printing plate.
There is no restriction | limiting in particular in the coloring agent which can be used here, According to a use, well-known various color materials and (pigment, dye) can be selected suitably, and can be used. For example, when forming an image excellent in weather resistance, a pigment is preferable. As the dye, both water-soluble dyes and oil-soluble dyes can be used, but oil-soluble dyes are preferred.

[Pigment]
The pigment preferably used in the present invention will be described.
The pigment is not particularly limited, and all commercially available organic and inorganic pigments or pigments dispersed in an insoluble resin or the like as a dispersion medium, or the resin is grafted onto the pigment surface Can be used. Moreover, what dye | stained the resin particle with dye can be used.
Examples of these pigments include, for example, “Pigment Dictionary” (2000), edited by Seijiro Ito. Herbst, K.M. Hunger “Industrial Organic Pigments”, JP 2002-12607 A, JP 2002-188025 A, JP 2003-26978 A, and JP 2003-342503 A3.

  Specific examples of organic pigments and inorganic pigments that can be used in the present invention include C.I. I. Pigment Yellow 1 (Fast Yellow G etc.), C.I. I. A monoazo pigment such as C.I. Pigment Yellow 74; I. Pigment Yellow 12 (disaji yellow AAA, etc.), C.I. I. Disazo pigments such as C.I. Pigment Yellow 17; I. Non-benzidine type azo pigments such as CI Pigment Yellow 180; I. Azo lake pigments such as C.I. Pigment Yellow 100 (eg Tartrazine Yellow Lake); I. Condensed azo pigments such as CI Pigment Yellow 95 (Condensed Azo Yellow GR, etc.); I. Acidic dye lake pigments such as C.I. Pigment Yellow 115 (such as quinoline yellow lake); I. Basic dye lake pigments such as CI Pigment Yellow 18 (Thioflavin Lake, etc.), anthraquinone pigments such as Flavantron Yellow (Y-24), isoindolinone pigments such as Isoindolinone Yellow 3RLT (Y-110), and quinophthalone yellow Quinophthalone pigments such as (Y-138), isoindoline pigments such as isoindoline yellow (Y-139), C.I. I. Nitroso pigments such as C.I. Pigment Yellow 153 (nickel nitroso yellow, etc.); I. And metal complex salt azomethine pigments such as CI Pigment Yellow 117 (copper azomethine yellow, etc.).

  C. As a thing which exhibits red or magenta color, C.I. I. Monoazo pigments such as CI Pigment Red 3 (Toluidine Red, etc.); I. Disazo pigments such as C.I. Pigment Red 38 (Pyrazolone Red B, etc.); I. Pigment Red 53: 1 (Lake Red C, etc.) and C.I. I. Azo lake pigments such as C.I. Pigment Red 57: 1 (Brilliant Carmine 6B); I. Condensed azo pigments such as C.I. Pigment Red 144 (condensed azo red BR, etc.); I. Acidic dye lake pigments such as C.I. Pigment Red 174 (Phloxine B Lake, etc.); I. Basic dye lake pigments such as C.I. Pigment Red 81 (Rhodamine 6G ′ Lake, etc.); I. Anthraquinone pigments such as C.I. Pigment Red 177 (eg, dianthraquinonyl red); I. Thioindigo pigments such as C.I. Pigment Red 88 (Thioindigo Bordeaux, etc.); I. Perinone pigments such as C.I. Pigment Red 194 (perinone red, etc.); I. Perylene pigments such as C.I. Pigment Red 149 (perylene scarlet, etc.); I. Pigment violet 19 (unsubstituted quinacridone), C.I. I. Quinacridone pigments such as CI Pigment Red 122 (quinacridone magenta, etc.); I. Isoindolinone pigments such as CI Pigment Red 180 (isoindolinone red 2BLT, etc.); I. And alizarin lake pigments such as CI Pigment Red 83 (Madder Lake, etc.).

  As a pigment exhibiting blue or cyan, C.I. I. Disazo pigments such as C.I. Pigment Blue 25 (Dianisidine Blue, etc.); I. Phthalocyanine pigments such as C.I. Pigment Blue 15 (phthalocyanine blue, etc.); I. Acidic dye lake pigments such as C.I. Pigment Blue 24 (Peacock Blue Lake, etc.); I. Basic dye lake pigments such as C.I. Pigment Blue 1 (Viclotia Pure Blue BO Lake, etc.); I. Anthraquinone pigments such as C.I. Pigment Blue 60 (Indantron Blue, etc.); I. And alkali blue pigments such as CI Pigment Blue 18 (Alkali Blue V-5: 1).

As a pigment exhibiting green, C.I. I. Pigment green 7 (phthalocyanine green), C.I. I. Phthalocyanine pigments such as C.I. Pigment Green 36 (phthalocyanine green); I. And azo metal complex pigments such as CI Pigment Green 8 (Nitroso Green).
As a pigment exhibiting an orange color, C.I. I. An isoindoline pigment such as C.I. Pigment Orange 66 (isoindoline orange); I. And anthraquinone pigments such as CI Pigment Orange 51 (dichloropyrantron orange).

Examples of the black pigment include carbon black, titanium black, and aniline black.
Specific examples of white pigments include basic lead carbonate (2PbCO3Pb (OH) 2, so-called silver white), zinc oxide (ZnO, so-called zinc white), titanium oxide (TiO2, so-called titanium white), strontium titanate (SrTiO3, so-called titanium strontium white) can be used.

  Here, titanium oxide has a smaller specific gravity than other white pigments, a large refractive index, and is chemically and physically stable, so that it has a large hiding power and coloring power as a pigment. Excellent durability against other environments. Therefore, it is preferable to use titanium oxide as the white pigment. Of course, other white pigments (may be other than the listed white pigments) may be used as necessary.

For dispersing the pigment, for example, a dispersion device such as a ball mill, a sand mill, an attritor, a roll mill, a jet mill, a homogenizer, a paint shaker, a kneader, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, or a wet jet mill is used. be able to.
It is also possible to add a dispersant when dispersing the pigment. Examples of the dispersant include a hydroxyl group-containing carboxylic acid ester, a salt of a long-chain polyaminoamide and a high molecular weight acid ester, a salt of a high molecular weight polycarboxylic acid, a high molecular weight unsaturated acid ester, a high molecular weight copolymer, a modified polyacrylate, an aliphatic Examples thereof include polyvalent carboxylic acids, naphthalene sulfonic acid formalin condensates, polyoxyethylene alkyl phosphate esters, and pigment derivatives. It is also preferable to use a commercially available polymer dispersant such as the Solsperse series from Zeneca.
Moreover, it is also possible to use a synergist according to various pigments as a dispersion aid. These dispersants and dispersion aids are preferably added in an amount of 1 to 50 parts by mass with respect to 100 parts by mass of the pigment.

  In the ink composition, as a dispersion medium for various components such as pigments, a solvent may be added, or the solvent-free low molecular weight component (a) cationic polymerizable compound may be used as a dispersion medium. However, the ink composition of the present invention is an active energy curable ink, and is preferably solventless in order to cure the ink after it is applied to a recording medium. This is because if the solvent remains in the cured ink image, the solvent resistance is deteriorated or a VOC (Volatile Organic Compound) problem of the remaining solvent occurs. From such a viewpoint, as the dispersion medium, (a) a cation polymerizable compound is used, and among them, it is preferable to select a cation polymerizable monomer having the lowest viscosity in terms of dispersion suitability and handling property of the ink composition. .

The average particle size of the pigment is preferably 0.02 to 4 μm, more preferably 0.02 to 2 μm, and more preferably 0.02 to 1.0 μm.
The selection of pigment, dispersant, dispersion medium, dispersion conditions, and filtration conditions are set so that the average particle diameter of the pigment particles is within the above-mentioned preferable range. By controlling the particle size, clogging of the head nozzle can be suppressed, and ink storage stability, ink transparency, and curing sensitivity can be maintained.

〔dye〕
The dye used in the present invention is preferably oil-soluble. Specifically, it means that the solubility in water at 25 ° C. (the mass of the dye dissolved in 100 g of water) is 1 g or less, preferably 0.5 g or less, more preferably 0.1 g or less. Therefore, a so-called water-insoluble oil-soluble dye is preferably used.

The dye used in the present invention preferably has an oil-solubilizing group introduced into the above-described dye mother core in order to dissolve the necessary amount in the ink composition.
As the oil-solubilizing group, long chain, branched alkyl group, long chain, branched alkoxy group, long chain, branched alkylthio group, long chain, branched alkylsulfonyl group, long chain, branched acyloxy group, long chain, branched alkoxycarbonyl group, Long chain, branched acyl group, long chain, branched acylamino group long chain, branched alkylsulfonylamino group, long chain, branched alkylaminosulfonyl group and these long chains, aryl groups containing branched substituents, aryloxy groups, aryloxycarbonyl Group, arylcarbonyloxy group, arylaminocarbonyl group, arylaminosulfonyl group, arylsulfonylamino group and the like.
In addition, for water-soluble dyes having carboxylic acid and sulfonic acid, long chain, branched alcohol, amine, phenol, aniline derivatives are used as oil-solubilizing alkoxycarbonyl groups, aryloxycarbonyl groups, alkylaminosulfonyl groups, A dye may be obtained by conversion to an arylaminosulfonyl group.

The oil-soluble dye preferably has a melting point of 200 ° C. or lower, more preferably has a melting point of 150 ° C. or lower, and still more preferably has a melting point of 100 ° C. or lower. By using an oil-soluble dye having a low melting point, the precipitation of dye crystals in the ink composition is suppressed, and the storage stability of the ink composition is improved.
Further, it is desirable that the oxidation potential is noble (high) in order to improve fading, particularly resistance to oxidizing substances such as ozone and curing characteristics. For this reason, as the oil-soluble dye used in the present invention, those having an oxidation potential of 1.0 V (vs SCE) or more are preferably used. The oxidation potential is preferably higher, the oxidation potential is more preferably 1.1 V (vs SCE) or more, and particularly preferably 1.15 V (vs SCE) or more.

As the yellow dye, a compound having a structure represented by the general formula (Y-I) described in JP-A No. 2004-250483 is preferable.
Particularly preferred dyes are dyes represented by the general formulas (Y-II) to (Y-IV) described in paragraph [0034] of JP-A No. 2004-250483. And the compounds described in paragraph numbers [0060] to [0071] of JP-A-250483. The oil-soluble dye of the general formula (Y-I) described in the publication may be used not only for yellow but also for inks of any color such as black ink and red ink.

The magenta dye is preferably a compound having a structure represented by the general formulas (3) and (4) described in JP-A No. 2002-114930. Specific examples include paragraphs of JP-A No. 2002-114930. Examples include the compounds described in [0054] to [0073].
Particularly preferred dyes are azo dyes represented by the general formulas (M-1) to (M-2) described in paragraph numbers [0084] to [0122] of JP-A No. 2002-121414, and specific examples Examples thereof include compounds described in paragraph numbers [0123] to [0132] of JP-A No. 2002-121414. The oil-soluble dyes represented by the general formulas (3), (4) and (M-1) to (M-2) described in the publication are used not only for magenta but also for any color ink such as black ink and red ink. May be.

Examples of cyan dyes include dyes represented by formulas (I) to (IV) described in JP-A No. 2001-181547, and paragraphs [0063] to [0078] of JP-A No. 2002-121414. The dyes represented by the general formulas (IV-1) to (IV-4) are mentioned as preferable examples, and specific examples include paragraph numbers [0052] to [0066] of JP-A No. 2001-181547. Examples thereof include the compounds described in paragraph Nos. [0079] to [0081] of Kai 2002-121414.
Particularly preferred dyes are phthalocyanine dyes represented by general formulas (CI) and (C-II) described in paragraphs [0133] to [0196] of JP-A No. 2002-121414, A phthalocyanine dye represented by formula (C-II) is preferred. Specific examples thereof include the compounds described in JP-A No. 2002-121414, paragraph numbers [0198] to [0201]. The oil-soluble dyes of the formulas (I) to (IV), (IV-1) to (IV-4), (CI) and (C-II) are not only cyan but also black ink or green ink. The ink may be used for any color ink.

These colorants are preferably added in an amount of 1 to 20% by mass in terms of solid content in the ink composition, and more preferably 2 to 10% by mass.
In the ink composition of the present invention, various additives can be used in combination with the essential components according to the purpose. These optional components will be described.

[Ultraviolet absorber]
In the present invention, an ultraviolet absorber can be used from the viewpoint of improving the weather resistance of the obtained image and preventing discoloration.
Examples of the ultraviolet absorber are described in JP-A-58-185679, JP-A-61-190537, JP-A-2-782, JP-A-5-97075, JP-A-9-34057, and the like. Benzotriazole compounds, benzophenone compounds described in JP-A No. 46-2784, JP-A No. 5-194843, US Pat. No. 3,214,463, etc., JP-B Nos. 48-30492 and 56-21141 Cinnamic acid compounds described in JP-A-10-88106, JP-A-4-298503, JP-A-8-53427, JP-A-8-239368, JP-A-10-182621, JP The triazine compounds described in JP-A-8-501291, Research Disclosure No. Examples thereof include compounds described in No. 24239, compounds that emit ultraviolet light by absorbing ultraviolet rays typified by stilbene and benzoxazole compounds, so-called fluorescent brighteners, and the like.
The addition amount is appropriately selected according to the purpose, but is generally about 0.5 to 15% by mass in terms of solid content.

[Sensitizer]
A sensitizer may be added to the ink composition of the present invention as necessary for the purpose of improving the acid generation efficiency of the photoacid generator and increasing the photosensitive wavelength. Any sensitizer may be used as long as the photoacid generator is sensitized by an electron transfer mechanism or an energy transfer mechanism. Preferably, aromatic polycondensed compounds such as anthracene, 9,10-dialkoxyanthracene, pyrene and perylene, aromatic ketone compounds such as acetophenone, benzophenone, thioxanthone and Michlerketone, heterocyclic compounds such as phenothiazine and N-aryloxazolidinone Is mentioned. The addition amount is appropriately selected according to the purpose, but is generally 0.01 to 1 mol%, preferably 0.1 to 0.5 mol%, based on the photoacid generator.

〔Antioxidant〕
An antioxidant can be added to improve the stability of the ink composition. Examples of the antioxidant include European published patents, 223739, 309401, 309402, 310551, 310552, 359416, and 3435443. JP, 54-85535, 62-262417, 63-113536, 63-163351, JP-A-2-262654, JP-A-2-71262, Examples thereof include those described in Kaihei 3-121449, JP-A-5-61166, JP-A-5-119449, US Pat. No. 4,814,262, US Pat. No. 4,980,275, and the like.
The addition amount is appropriately selected according to the purpose, but is generally about 0.1 to 8% by mass in terms of solid content.

[Anti-fading agent]
In the ink composition of the present invention, various organic and metal complex anti-fading agents can be used. Examples of the organic anti-fading agent include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, and heterocycles. Examples of the metal complex anti-fading agent include nickel complexes and zinc complexes. No. 17643, VII, I to J, No. 15162, ibid. No. 18716, page 650, left column, ibid. No. 36544 at page 527, ibid. 307105, page 872, ibid. The compounds described in the patent cited in No. 15162 and the compounds included in the general formulas and compound examples of representative compounds described in JP-A-62-215272, pages 127 to 137 can be used. .
The addition amount is appropriately selected according to the purpose, but is generally about 0.1 to 8% by mass in terms of solid content.

[Conductive salts]
Conductive salts such as potassium thiocyanate, lithium nitrate, ammonium thiocyanate, and dimethylamine hydrochloride can be added to the ink composition of the present invention for the purpose of controlling ejection properties.

〔solvent〕
In order to improve the adhesion to the recording medium, it is also effective to add a very small amount of an organic solvent to the ink composition of the present invention.
Examples of the solvent include ketone solvents such as acetone, methyl ethyl ketone, and diethyl ketone, alcohol solvents such as methanol, ethanol, 2-propanol, 1-propanol, 1-butanol, and tert-butanol, and chlorine such as chloroform and methylene chloride. Solvents, aromatic solvents such as benzene and toluene, ester solvents such as ethyl acetate, butyl acetate and isopropyl acetate, ether solvents such as diethyl ether, tetrahydrofuran and dioxane, glycols such as ethylene glycol monomethyl ether and ethylene glycol dimethyl ether And ether solvents.
In this case, it is effective to add the solvent within a range that does not cause the problem of solvent resistance and VOC, and the amount is preferably 0.1 to 5% by mass, more preferably 0.1 to 3% by mass with respect to the whole ink composition. % Range.

[Polymer compound]
Various polymer compounds can be added to the ink composition of the present invention in order to adjust film physical properties. High molecular compounds include acrylic polymers, polyvinyl butyral resins, polyurethane resins, polyamide resins, polyester resins, epoxy resins, phenol resins, polycarbonate resins, polyvinyl butyral resins, polyvinyl formal resins, shellacs, vinyl resins, acrylic resins. Rubber resins, waxes and other natural resins can be used. Two or more of these may be used in combination. Of these, vinyl copolymer obtained by copolymerization of acrylic monomers is preferred. Furthermore, a copolymer containing “carboxyl group-containing monomer”, “methacrylic acid alkyl ester”, or “acrylic acid alkyl ester” as a structural unit is also preferably used as the copolymer composition of the polymer binder.

[Surfactant]
A surfactant may be added to the ink composition of the present invention.
Examples of the surfactant include those described in JP-A Nos. 62-173463 and 62-183457. For example, anionic surfactants such as dialkylsulfosuccinates, alkylnaphthalenesulfonates, fatty acid salts, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, polyoxyethylene / polyoxypropylene blocks Nonionic surfactants such as copolymers, and cationic surfactants such as alkylamine salts and quaternary ammonium salts. An organic fluoro compound may be used in place of the surfactant. The organic fluoro compound is preferably hydrophobic. Examples of the organic fluoro compounds include fluorine surfactants, oily fluorine compounds (eg, fluorine oil) and solid fluorine compound resins (eg, tetrafluoroethylene resin). No. (columns 8 to 17) and those described in JP-A Nos. 62-135826.

In addition to this, if necessary, for example, leveling additives, matting agents, waxes for adjusting film physical properties, polymerization to inhibit the adhesion to recording media such as polyolefin and PET, and the like, The tackifier which does not do can be contained.
As the tackifier, specifically, a high molecular weight adhesive polymer described in JP-A-2001-49200, 5-6p (for example, (meth) acrylic acid and an alkyl group having 1 to 20 carbon atoms). An ester with an alcohol having, an ester of (meth) acrylic acid with an alicyclic alcohol having 3 to 14 carbon atoms, a copolymer comprising an ester of (meth) acrylic acid with an aromatic alcohol having 6 to 14 carbon atoms) And a low molecular weight tackifying resin having a polymerizable unsaturated bond.

[Radical polymerization ink composition]
The radical polymerization ink composition contains (d) a radical polymerizable compound, (e) a polymerization initiator, and (f) a colorant. If desired, it may further contain a sensitizing dye, a co-sensitizer and the like.
Hereinafter, each component used for the radical polymerization ink composition will be sequentially described.

(D) [Radically polymerizable compound]
Examples of the radically polymerizable compound include compounds having an ethylenically unsaturated bond capable of addition polymerization as described below.

[Compound having an ethylenically unsaturated bond capable of addition polymerization]
Examples of the compound having an addition polymerizable ethylenically unsaturated bond that can be used in the ink composition of the present invention include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid). Etc.) and an aliphatic polyhydric alcohol compound, an amide of the unsaturated carboxylic acid and an aliphatic polyamine compound, and the like.

  Specific examples of the monomer of an ester of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid include acrylic acid esters such as ethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butanediol diacrylate, and tetramethylene glycol. Diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate, 1,4-cyclohexanediol di Acrylate, Tetraethylene glycol diacrylate, Pentaerythritol diacrylate, Pentaerythritol triacrylate , Pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, polyester acrylate oligomer.

  Methacrylic acid esters include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, Hexanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, bis [p- (3-methacryloxy 2-hydroxypro ) Phenyl] dimethyl methane, bis - [p- (acryloxyethoxy) phenyl] dimethylmethane. Itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate, 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate And sorbitol tetritaconate.

  Examples of crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, and sorbitol tetradicrotonate. Examples of isocrotonic acid esters include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate. Examples of maleic acid esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate. Furthermore, the mixture of the above-mentioned ester monomer can also be mention | raise | lifted. Specific examples of an amide monomer of an aliphatic polyvalent amine compound and an unsaturated carboxylic acid include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexa. Examples include methylene bis-methacrylamide, diethylenetriamine trisacrylamide, xylylene bisacrylamide, and xylylene bismethacrylamide.

Other examples include vinyls containing a hydroxyl group represented by the following general formula (A) in a polyisocyanate compound having two or more isocyanate groups per molecule described in JP-B-48-41708. Examples thereof include a vinylurethane compound containing two or more polymerizable vinyl groups in one molecule to which a monomer is added. CH2 = C (R) COOCH2CH (R ') OH (A) (where R and R' represent H or CH3)
Further, as described in JP-A-51-37193, urethane acrylates, JP-A-48-64183, JP-B-49-43191, JP-B-52-30490, etc. Polyfunctional acrylates and methacrylates such as polyester acrylates and epoxy acrylates obtained by reacting an epoxy resin with (meth) acrylic acid can be used. Furthermore, Journal of Japan Adhesion Association vol.20, No. 7, pages 300 to 308 (1984) as photocurable monomers and oligomers can also be used. In the present invention, these monomers can be used in a chemical form such as a prepolymer, that is, a dimer, a trimer and an oligomer, or a mixture thereof and a copolymer thereof.

  The amount of the radical polymerizable compound used is usually 1 to 99.99%, preferably 5 to 90.0%, more preferably 10 to 70%, based on all components of the ink composition. Mass%).

(E) [Photoinitiator]
Next, the photopolymerization initiator used in the radical polymerization ink composition of the present invention will be described.
The photopolymerization initiator in the present invention is a compound that undergoes a chemical change through the action of light or interaction with the electronically excited state of a sensitizing dye to generate at least one of radicals, acids, and bases. It is.

  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, (to) azinium compounds, (thi) metallocene compounds, (li) active ester compounds, (nu) compounds having a carbon halogen bond, and the like.

(F) [Colorant]
The same (c) colorant as described in the cationic polymerization ink composition can be used.
In the ink composition of the present invention, various additives can be used in combination with the essential components according to the purpose. These optional components will be described.
[Sensitizing dye]
In the present invention, a sensitizing dye may be added 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.
Polynuclear aromatics (eg, pyrene, perylene, triphenylene), xanthenes (eg, fluorescein, eosin, erythrosine, rhodamine B, rose bengal), cyanines (eg, thiacarbocyanine, oxacarbocyanine), merocyanines ( For example, merocyanine, carbomerocyanine), thiazines (eg, thionine, methylene blue, toluidine blue), acridines (eg, acridine orange, chloroflavin, acriflavine), anthraquinones (eg, anthraquinone), squalium (eg, squalium) ), Coumarins (eg, 7-diethylamino-4-methylcoumarin).

[Co-sensitizer]
Furthermore, the ink of the present invention may contain a known compound having a function of further improving sensitivity or suppressing polymerization inhibition by oxygen as a co-sensitizer.

  Examples of such co-sensitizers include amines such as MR Sander et al., “Journal of Polymer Society”, Vol. 10, page 3173 (1972), Japanese Examined Patent Publication No. 44-20189, Japanese Patent Laid-Open No. 51-82102. Publication, JP 52-134692, JP 59-138205, JP 60-84305, JP 62-18537, JP 64-33104, Research Disclosure 33825 Specifically, triethanolamine, p-dimethylaminobenzoic acid ethyl ester, p-formyldimethylaniline, p-methylthiodimethylaniline and the like can be mentioned.

  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. Examples thereof include disulfide compounds, and specific examples include 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, 2-mercapto-4 (3H) -quinazoline, β-mercaptonaphthalene and the like.

  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 Japanese Patent Application No. 6-191605 H, Ge-H compound, etc. are mentioned.

  Moreover, it is preferable to add 200-20000 ppm of a polymerization inhibitor from a viewpoint of improving storability. The ink for ink jet recording of the present invention is preferably ejected by heating and lowering the viscosity in the range of 40 to 80 ° C., and a polymerization inhibitor is preferably added to prevent clogging of the head due to thermal polymerization. Examples of the polymerization inhibitor include hydroquinone, benzoquinone, p-methoxyphenol, TEMPO, TEMPOL, and cuperon Al.

[Others]
In addition, known compounds can be used as necessary. For example, surfactants, leveling additives, matting agents, polyester resins for adjusting film properties, polyurethane resins, vinyl resins, acrylic resins, etc. Resin, rubber resin, wax and the like can be appropriately selected and used. In order to improve the adhesion to a recording medium such as polyolefin or PET, it is also preferable to contain a tackifier that does not inhibit the polymerization. Specifically, high molecular weight adhesive polymers described in JP-A-2001-49200, 5-6p (for example, esters of (meth) acrylic acid and alcohols having an alkyl group having 1 to 20 carbon atoms) , An ester of (meth) acrylic acid and an alicyclic alcohol having 3 to 14 carbon atoms, a copolymer formed of an ester of (meth) acrylic acid and an aromatic alcohol having 6 to 14 carbon atoms), A low molecular weight tackifying resin having a saturated bond.

  It is also effective to add a trace amount of organic solvent in order to improve the adhesion to the recording medium. In this case, it is effective to add the solvent within a range that does not cause the problem of solvent resistance and VOC. % Range.

  In addition, as a means for preventing a decrease in sensitivity due to the light-shielding effect of the ink color material, it is also preferable to combine a cationic polymerizable monomer having a long polymerization initiator lifetime with a polymerization initiator to obtain a radical-cation hybrid type curable ink. One.

[Water-based ink composition]
The aqueous ink composition contains a water-soluble photopolymerization initiator that generates radicals by the action of a polymerizable compound and active energy. If desired, it may further contain a coloring material and the like.

[Polymerizable compound]
As the polymerizable compound contained in the aqueous ink composition of the present invention, a polymerizable compound contained in a known aqueous ink composition can be used.
A reactive material can be added to the water-based ink composition in order to optimize the formulation considering end-user characteristics such as curing speed, adhesion, and flexibility. Examples of such reactive materials include (meth) acrylate (ie, acrylate and / or methacrylate) monomers and oligomers, epoxides, and oxetanes.
Examples of acrylate monomers include phenoxyethyl acrylate, octyl decyl acrylate, tetrahydrofuryl acrylate, isobornyl acrylate, hexanediol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, polyethylene glycol diacrylate (e.g., tetraethylene glycol). Diacrylate), dipropylene glycol diacrylate, tri (propylene glycol) triacrylate, neopentyl glycol diacrylate, bis (pentaerythritol) hexaacrylate, ethoxylated or propoxylated glycol and polyol acrylate (e.g. propoxylated neopentyl glycol Diacrylate, ethoxylated trimethylol proppant Acrylate), and mixtures thereof.
Examples of acrylate oligomers include ethoxylated polyethylene glycol, ethoxylated trimethylolpropane acrylate and polyether acrylate and ethoxylates thereof, and urethane acrylate oligomers.
Examples of methacrylates include hexanediol dimethacrylate, trimethylolpropane trimethacrylate, triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, ethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, and mixtures thereof.
The amount of oligomer added is preferably 1 to 80% by weight, more preferably 1 to 10% by weight, based on the total weight of the ink composition.

[Water-soluble photopolymerization initiator that generates radicals by the action of active energy]
The polymerization initiator that can be used in the ink composition of the invention will be described. As an example, for example, a photopolymerization initiator having a wavelength of up to about 400 nm may be mentioned. As such a photopolymerization initiator, for example, a photopolymerization initiator represented by the following general formula (hereinafter referred to as TX) which is a substance having a functionality in a long wavelength region, that is, a sensitivity to generate a radical upon receiving ultraviolet rays. In the present invention, it is particularly preferable to select and use them appropriately.

  In the above general formulas TX-1 to TX-3, R2 is-(CH2) x- (x = 0 or 1), -O- (CH2) y- (y = 1 or 2), substituted or unsubstituted phenylene Represents a group. When R2 is a phenylene group, at least one hydrogen atom in the benzene ring is, for example, a carboxyl group or a salt thereof, a sulfonic acid or a salt thereof, a linear or branched alkyl having 1 to 4 carbon atoms. May be substituted with one or more groups or atoms selected from a group, a halogen atom (fluorine, chlorine, bromine, etc.), an alkoxyl group having 1 to 4 carbon atoms, an aryloxy group such as a phenoxy group, and the like. . M represents a hydrogen atom or an alkali metal (for example, Li, Na, K, etc.). R3 and R4 each independently represents a hydrogen atom or a substituted or unsubstituted alkyl group. Examples of the alkyl group include, for example, a linear or branched alkyl group having about 1 to 10 carbon atoms, particularly about 1 to 3 carbon atoms. Moreover, as an example of the substituent of these alkyl groups, a halogen atom (a fluorine atom, a chlorine atom, an oxalic atom etc.), a hydroxyl group, an alkoxyl group (C1-C3 grade) etc. are mentioned, for example. M represents an integer of 1 to 10.

  Further, in the present invention, a water-soluble derivative (hereinafter abbreviated as an IC system) of a photopolymerization initiator Irgacure 2959 (trade name: manufactured by Ciba Specialty Chemicals) having the following general formula may be used. Specifically, IC-1 to IC-3 having the following formulas can be used.

[Prescription for clear ink]
The above-mentioned water-soluble polymerizable compound can be made into a clear ink by making it into the form of a transparent water-based ink without containing the above-mentioned coloring material. In particular, if it is prepared so as to have ink jet recording characteristics, a clear ink for water-based photocurable ink jet recording can be obtained. If such an ink is used, a clear film can be obtained because it does not contain a coloring material. Clear inks that do not contain color materials can be used for undercoats to give recording materials suitable for image printing, or for surface protection of images formed with ordinary inks, further decoration and gloss The use etc. for the overcoat for the purpose of provision etc. are mentioned. In the clear ink, colorless pigments or fine particles that are not intended for coloring can be dispersed and contained according to these applications. By adding these, it is possible to improve various properties such as image quality, fastness, and workability (handling property) of the printed matter in both the undercoat and the overcoat.

  Prescription conditions for application to such a clear ink include 10 to 85% of a water-soluble polymerizable compound as a main component of the ink, a photopolymerization initiator (for example, an ultraviolet polymerization catalyst), and the above water-soluble polymerization. It is preferable to prepare such that 1 to 10 parts by mass with respect to 100 parts by mass of the active compound and at least 0.5 part of the photopolymerization initiator is simultaneously contained with respect to 100 parts of ink.

[Material composition of colorant-containing ink]
When the above-described water-soluble polymerizable compound is used in an ink containing a color material, the concentration of the polymerization initiator and the polymerizable substance in the ink can be adjusted in accordance with the absorption characteristics of the contained color material. preferable. As described above, the amount of water or solvent is in the range of 40% to 90%, preferably 60% to 75%, based on mass, as the blending amount. Furthermore, the content of the polymerizable compound in the ink is in the range of 1% to 30%, preferably in the range of 5% to 20% on the mass basis with respect to the total amount of the ink. Although the polymerization initiator depends on the content of the polymerizable compound, it is generally in the range of 0.1 to 7%, preferably 0.3 to 5% on the mass basis with respect to the total amount of the ink.

  When a pigment is used as the ink coloring material, the concentration of the pure pigment in the ink is generally in the range of 0.3% by mass to 10% by mass with respect to the total amount of the ink. The coloring power of the pigment depends on the dispersion state of the pigment particles, but if it is in the range of about 0.3 to 1%, it becomes a range used as a light-colored ink. On the other hand, if it is more than that, it gives a density used for general color coloring.

[Preferred physical properties of ink composition]
The ink composition of the present invention preferably has an ink viscosity of 20 mPa · s or less, more preferably 10 mPa · s or less at the temperature at the time of ejection in consideration of ejection properties. It is preferable to adjust and determine the composition ratio.

  The common surface tension of the ink composition of the present invention is preferably 20 to 40 mN / m, more preferably 25 to 35 mN / m. When recording on various recording media such as polyolefin, PET, coated paper, and uncoated paper, 20 mN / m or more is preferable from the viewpoint of bleeding and penetration, and the wettability is preferably 40 mN / m or less.

The ink composition of the present invention thus adjusted is suitably used as an ink for inkjet recording. When used as an ink for ink jet recording, the ink composition is ejected onto a recording medium by an ink jet printer, and then the ejected ink composition is irradiated with active energy and cured to perform recording.
In the printed matter obtained with this ink, the image portion is cured by irradiation with active energy such as ultraviolet rays, and the strength of the image portion is excellent. Therefore, in addition to image formation with ink, for example, an ink receiving layer ( It can be used for various purposes such as formation of an image portion.

1 is a configuration diagram of an active energy curable ink jet recording apparatus targeted by the present invention. FIG. 2A and 2B are views in the vicinity of the head unit according to the first embodiment of the present invention, where FIG. 3A is a schematic front view, and FIG. 4A and 4B are views in the vicinity of a head unit according to a second embodiment of the present invention, where FIG. 5A is a schematic front view, and FIG. FIG. 2 is a conceptual diagram illustrating an ink supply system that supplies ink to a head unit in the ink jet recording apparatus of FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Active energy curable inkjet recording device 11-1, 11-2 Head unit 12-1, 12-2 Light source 13 Platen 14-1, 14-2 Head unit vertical mechanism 16 Recording medium vertical mechanism 17 Light-shielding member and platen It is a coupling member.
18-1 and 18-2 Light-shielding members 19-1 and 19-2 according to Embodiment 2 of the present invention Light-shielding member A according to Embodiment 1 The recording medium transport direction S is the recording medium t1 and the lower end of the head unit and the recording medium. Distance t2 Distance between the lower end of the light shielding member and the recording medium

Claims (7)

A head unit that collectively fixes a plurality of inkjet heads that discharge energy-curable functional materials from nozzles toward a recording medium based on an image signal, and a recording medium that conveys the recording medium to a position facing the inkjet head In an ink jet recording apparatus having a conveying means, an energy irradiation device that is located near the ink jet head so as to face the recording medium, and a supply path that supplies a functional material to the ink jet head.
An ink jet apparatus, wherein a light shielding member that shields the energy is fixed to at least the energy irradiation apparatus side of the head unit. A head unit that collectively fixes a plurality of inkjet heads that discharge energy-curable functional materials from nozzles toward a recording medium based on an image signal, and a recording medium that conveys the recording medium to a position facing the inkjet head In an ink jet recording apparatus having a conveying means, an energy irradiation device that is located near the ink jet head so as to face the recording medium, and a supply path that supplies a functional material to the ink jet head.
An ink jet apparatus, wherein a light shielding member for shielding the energy is fixed to the recording medium conveying means.   2. The ink jet recording apparatus according to claim 1, wherein a distance between the lower surface of the light shielding member and the recording medium is equal to or less than a distance between the lower surface of the ink jet head and the recording medium.   The inkjet recording apparatus according to claim 1, further comprising an interval adjusting mechanism capable of adjusting an interval between the light shielding member and the recording medium.   5. The ink jet recording apparatus according to claim 4, wherein the distance adjusting mechanism also serves as a distance adjusting mechanism between recording media on the lower surface of the ink jet head.   The ink jet recording apparatus is connected to the supply path, and has a reservoir for storing the liquid functional material, and a vacuum deaeration mechanism provided in the ink jet head or the supply path or the reservoir. The ink jet recording apparatus according to claim 1.   The ink jet recording apparatus according to claim 1, wherein the ink jet head unit is a full line type.

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