JP2007283716A - Printing surface smoothing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive printing surface smoothing apparatus having high productivity, capable of forming a high quality image to various media to be recorded. <P>SOLUTION: The printing surface smoothing apparatus 30 executes an after-treatment for surface smoothing after recording on the medium S to be recorded for printing. The apparatus 30 is equipped with a cover ink feeding means 40 for feeding an active energy-curable transparent ink 4 on the surface of the medium S to be recorded after printing, and the active energy-curable transparent ink smoothing means 50 arranged on the downstream of the cover ink feeding means 40, and spreading smoothly the active energy-curable transparent ink by bringing a smooth water repellent surface 55a into contact with the surface of the active-energy-curable transparent ink 4 on the surface of the medium P to be recorded. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a printing surface smoothing device, and more particularly, a printing surface smoothing device capable of smoothing a printed recording medium surface and recording high-quality images with uniform gloss on various recording media. About.

  There are a number of apparatuses for printing on a recording medium, and among them, an inkjet head recording apparatus has recently been provided with a large number of nozzles with a very small diameter in the inkjet head and can be controlled delicately. In particular, it has the advantage of being able to perform high-speed, high-quality recording quickly without contact, and has been applied to many industrial systems. As the ink, active energy curable ink (for example, ultraviolet curable ink) is ejected toward the recording medium, and then the ink on the recording medium is irradiated with active energy (for example, ultraviolet light). In recent years, several systems have been proposed for active energy curable inkjet head recording devices that are cured and fixed because of their advantages such as excellent high-speed fixing performance, drawing on various recording media, and environmental friendliness.

  On the other hand, the ink that has been cured and fixed at the same time as the active energy is irradiated is not absorbed by the recording medium, and thus rises on the recording medium. This raised height is about 10 microns per color. In particular, the color portion where a plurality of colors of ink are superimposed becomes even higher, and its three-dimensional structure is perceived as noise (glossiness variation), which deteriorates the image and hinders high-quality image recording. was there.

  In order to solve this problem, there is one in which a recording process is performed on a recording medium after image formation (for example, see Reference 1). In addition, an image recording apparatus is disclosed in which transparent UV ink is jet-coated on the uppermost layer to erase surface irregularities (see, for example, Reference 2).

JP-A-9-70960 Japanese Patent Laying-Open No. 2005-074878

  However, in order to perform the lamination process, the recording medium is limited to the recording medium having a layer such as a thermoplastic resin on the surface, and the great advantage of the ink jet head recording apparatus that drawing on various recording media is possible. Is lost.

  Further, according to the image recording apparatus of Patent Document 2, it takes a lot of time for the liquid transparent UV ink to level after the application of the transparent UV ink and the surface irregularities are erased, resulting in a decrease in productivity. There wasn't. In addition, as a transparent UV ink, radical ink is the mainstream from the viewpoint of cost, etc., but radical ink causes polymerization inhibition due to oxygen in the atmosphere, so a strong light intensity is required to cure it, There is a problem that the cost of the light source becomes very high, and as a result, the price of the apparatus becomes very high.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a high-productivity, high-quality image on various recording media, and an inexpensive printing surface smoothing device. Is to provide.

The above object of the present invention is achieved by the following printing surface smoothing apparatus.
(1) Cover ink supply means for supplying an active energy curable transparent ink to the surface of the recording medium after printing in a printing surface smoothing apparatus that performs post-processing of surface smoothing after recording on the recording medium for printing And a downstream surface of the cover ink supply means in the transport direction of the recording medium for printing, and a smooth water-repellent surface in contact with the active energy curable transparent ink surface of the surface of the recording medium. A printing surface smoothing device comprising: an active energy curable transparent ink smoothing means for spreading ink smoothly.

  According to the printing surface smoothing apparatus having the above configuration, the active energy curable transparent ink that smoothly spreads the active energy curable transparent ink by bringing the smooth water-repellent surface into contact with the surface of the active energy curable transparent ink on the recording medium. Since the smoothing means is arranged downstream of the cover ink supply means for supplying the active energy curable transparent ink, the surface on which an uneven surface is formed by the active energy curable ink such as an ultraviolet curable ink is formed. The surface of the recording medium can be smoothed by covering it with an active energy curable transparent ink having a smooth surface. Thereby, a glossy and high-quality image can be obtained.

  In addition, the surface of the active energy curable transparent ink supplied from the cover ink supply means is brought into contact with a smooth water-repellent surface to spread and smooth the active energy curable transparent ink. The mold-type transparent ink spreads quickly and naturally and does not require much time until the surface irregularities are eliminated, and can be smoothed in a short time. Thereby, productivity can be improved.

  (2) The printing surface smoothing device according to (1), wherein the cover ink supply means is a varnish coater.

  According to the printing surface smoothing apparatus having the above configuration, since the cover ink supply means is a varnish coater, the active energy curable transparent ink is stabilized on the surface of the recording medium on which the uneven image is formed by a simple and inexpensive mechanism. Can be applied.

  (3) The printing surface smoothing device according to (1), wherein the cover ink supply means is an inkjet.

  According to the printing surface smoothing apparatus having the above configuration, since the cover ink supply means is an ink jet, the surface of the recording medium on which the uneven image is formed is controlled while controlling the supply amount of the active energy curable transparent ink. An energy curable transparent ink can be supplied, whereby a high-quality image with a uniform glossiness can be obtained more quickly.

  (4) Any one of (1) to (3) above, wherein the active energy curable transparent ink smoothing means forms a smooth plane by a continuous sheet stretched between a supply roll and a take-up roll. The printing surface smoothing apparatus as described in 2.

  According to the printing surface smoothing apparatus having the above-described configuration, the active energy curable transparent ink smoothing means forms a smooth flat surface by a continuous sheet stretched between a supply roll and a take-up roll, so that continuous use, etc. Even if the water repellency of the continuous sheet decreases, new continuous sheets can be fed out and replaced sequentially from the supply roll, and the surface of the recording medium can always be stabilized using a continuous sheet with excellent smoothing performance. Can be smoothed.

  (5) The active energy curable transparent ink smoothing means forms a smooth flat surface by a belt stretched between at least two rollers, according to any one of (1) to (3) above. Printing surface smoothing device.

  According to the printing surface smoothing apparatus having the above-described configuration, the active energy curable transparent ink smoothing means forms a smooth flat surface by a belt stretched between at least two rollers. A smooth plane can be constructed.

  (6) The printing surface smoothing device according to any one of (1) to (3), wherein the active energy curable transparent ink smoothing means forms a smooth line by an axis of the drum surface.

  According to the printing surface smoothing apparatus having the above-described configuration, the active energy curable transparent ink smoothing means is configured to form a smooth line by the axis of the drum surface, thereby miniaturizing and simplifying the active energy curable transparent ink smoothing means. This can contribute to the miniaturization of the entire apparatus.

  (7) Any of the above (1) to (6), wherein the active energy curable transparent ink is an active energy curable type, and an active energy irradiation light source is provided at or downstream of the active energy curable transparent ink smoothing means. The printing surface smoothing apparatus according to Item 1.

  According to the printing surface smoothing apparatus having the above configuration, the transparent ink is provided with the active energy curable transparent ink, and the active energy irradiation light source is provided at or downstream of the active energy curable transparent ink smoothing means. The ink can be cured by irradiating active energy from an active energy irradiation light source while smoothing the ink or immediately after smoothing. Thereby, the smooth surface excellent in smoothness is obtained.

  (8) The printing surface smoothing device according to (7), wherein the continuous sheet is a light transmission sheet.

  According to the printing surface smoothing apparatus having the above configuration, since the continuous sheet is a light transmission sheet, the active energy curable transparent ink is smoothly spread by bringing the continuous sheet into contact with the surface of the active energy curable transparent ink. The active energy can be irradiated through the continuous sheet to cure the active energy curable transparent ink. As a result, the active energy curable transparent ink can be cured in a state where the contact between the active energy curable transparent ink and the air is cut off. Therefore, even if the active energy curable transparent ink is a radical ink that causes polymerization inhibition due to oxygen in the atmosphere. , Polymerization inhibition can be suppressed, and an inexpensive active energy irradiation light source with low light intensity can be used.

  (9) The printing surface smoothing device according to (7), wherein the belt is a light transmission belt.

  According to the printing surface smoothing apparatus having the above-described configuration, since the belt is a light transmission belt, the active energy curable transparent material is irradiated with active energy from the belt in contact with the surface of the active energy curable transparent ink. The ink can be cured. Thereby, it can be cured in a state where the contact between the active energy curable transparent ink and the air is cut off, and even if the active energy curable transparent ink is a radical ink that causes polymerization inhibition due to oxygen in the atmosphere, Polymerization inhibition is suppressed, and an inexpensive active energy irradiation light source with low light intensity can be used.

  According to the present invention, it is possible to provide an inexpensive printing surface smoothing apparatus that has high productivity, can form high-quality images on various recording media, and is inexpensive.

Hereinafter, each embodiment of the printing surface smoothing apparatus according to the present invention will be described in detail with reference to the drawings.
(First embodiment)

  FIG. 1 is a schematic configuration diagram of an active energy curable inkjet head label printer suitable for application of a printing surface smoothing apparatus according to a first embodiment of the present invention, and FIG. 2 is a perspective view of an image forming unit in FIG. FIG. In each of the following embodiments, an ultraviolet curable inkjet head label printer using an ultraviolet curable ink as an active energy curable ink will be described as an example.

  As shown in FIGS. 1 and 2, the ultraviolet curable inkjet head label printing machine 100 includes an image forming area 80 in the order of the conveyance direction of a continuous sheet recording medium S for label printing (hereinafter also referred to as recording medium S). A smoothing area 81, a transport buffer area 82, and a label removal area 83 are provided.

  In common with each of the areas 80, 81, 82, 83, a conveying unit 10 that conveys the recording medium S of continuous sheets is disposed. The image forming area 80 is provided with an image forming unit 20 that forms an image by discharging and curing ultraviolet curable ink on the recording medium S. The smoothing area 81 includes the printing surface smoothing device 30. It is arranged. Further, in the label removal area 83, a die cutter 60, a waste removing portion 70 that is an unnecessary portion peeling portion, and a product winding portion 19 that winds a label L that is a product are disposed.

  The image forming unit 20 alternately includes inkjet heads 21Y, 21M, 21C, and 21B that discharge ultraviolet curable ink to the recording medium S, and an ultraviolet irradiation unit 22 as an active energy irradiation light source.

  The printing surface smoothing device 30 includes a varnish coater 40 that is a cover ink supply unit that supplies active energy curable transparent ink to the surface of the recording medium S, and an active energy curable transparent ink that smoothly spreads the active energy curable transparent ink. And an ultraviolet irradiation unit 56 as an active energy irradiation light source in the order of the conveyance direction of the recording medium S.

  As shown in FIG. 3, the recording medium S for label printing of continuous sheets has a two-sheet structure in which an adhesive sheet 1 having an adhesive 1a applied on the back surface is superposed on a release paper 2 as a mount. Then, after the image is printed on the surface of the pressure-sensitive adhesive sheet 1 by the image forming unit 20, it is peeled off from the release paper 2 and used.

  The transport unit 10 includes a supply roll 16 and a product take-up roll 19 that are rotationally driven by a transport motor 18 (not shown), and supplies a continuous sheet label printing recording medium S wound up in a roll shape. 16 is sequentially conveyed to an image forming area 80, a smoothing area 81, a conveyance buffer area 82, and a label removal area 83.

  The conveyance motor that drives the supply roll 16 and the product take-up roll 19 is connected to a conveyance motor control unit (not shown) and the rotation speed is controlled, and the conveyance speed of the recording medium S is controlled. For example, the recording medium S in the image forming area 80 and the smoothing area 81 is conveyed at a continuous constant speed. On the other hand, the recording medium S in the label removal area 83 is intermittently conveyed in conjunction with the movement of the die cutter 60.

  A conveyance buffer area 82 provided between the smoothing area 81 and the label removal area 83 is a continuous sheet label printing recording medium S produced by a difference in conveyance speed between the smoothing area 81 and the label removal area 83. It is designed to absorb slack.

  As shown in FIG. 2, the image forming unit 20 disposed in the image forming area 80 includes ink jet heads (ink jet head units) 21Y, 21M, 21C, and 21B that eject ink of each color, and the tip of the ink ejecting unit. Are arranged toward the recording medium S to be conveyed. The inkjet heads 21Y, 21M, 21C, and 21B are full-line type heads having an array of the lengths in the width direction of the recording medium S, and employ piezo-type heads. A head drive control unit (not shown) is connected to the inkjet heads 21Y, 21M, 21C, and 21B, and the ejection amount of each ink color is controlled.

  Further, an ultraviolet irradiation unit 22 as an active energy irradiation light source is disposed on the downstream side of each inkjet head 21Y, 21M, 21C, 21B, and is powerful enough to be cured immediately after the ink is placed on the recording medium S. Apply energy to cure. The arrangement of the ultraviolet irradiation unit 22 is configured to irradiate only the ink on the recording medium S, and does not irradiate the ink discharge ports of the inkjet heads 21Y, 21M, 21C, and 21B. Prevent ink curing at the outlet. Further, 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 22.

  The varnish coater 40 of the printing surface smoothing device 30 disposed in the smoothing area 81 (downstream of the image forming unit 20) is attached to the surface of a pair of application rollers 41 that rotate while sandwiching the recording medium S. The energy curable transparent ink is supplied and applied to the printed surface of the recording medium S. The application amount of the active energy curable transparent ink is an amount necessary for smoothing the irregularities on the surface of the recording medium S with the active energy curable transparent ink.

  The applied active energy curable transparent ink is an ink that can be cured by ultraviolet irradiation, and includes at least a polymerizable compound and a photoinitiator as main components. For example, a cationic polymerization ink composition, a radical polymerization ink composition Products, water-based ink compositions, and the like.

  In the active energy curable transparent ink smoothing means 50, the continuous sheet 55 supplied from the supply roll 51 is wound around a pair of rollers 53 and 54 arranged in parallel with the surface of the recording medium S being conveyed. After that, the book is placed so as to be wound around the winding roll 52. That is, the continuous sheet 55 is disposed between the pair of rollers 53 and 54 so as to be parallel to and almost in contact with the surface of the recording medium S.

  At least the surface of the continuous sheet 55 on the recording medium S side has high water repellency, and a smooth flat surface 55a for smoothing the active energy curable transparent ink in contact with the applied active energy curable transparent ink. Form. The continuous sheet 55 is, for example, a PET (polyethylene terephthalate) film, and the surface thereof is subjected to a fluorine treatment to give high water repellency.

  Even if the water repellency of the continuous sheet 55 is too low or too high, the surface smoothing of the active energy curable transparent ink is adversely affected. For example, the static contact angle with respect to the water active energy curable transparent ink is 20 It is desirable to have an appropriate water repellency of about ˜140 °. When the contact angle is too low, the peelability of the active energy curable transparent ink from the continuous sheet is deteriorated, and when it is forcibly peeled, the surface property is deteriorated. On the other hand, when the contact angle is too high, the active energy curable transparent ink is repelled on the continuous sheet surface, so that the ink is difficult to level and the surface property is deteriorated.

  On the downstream side of the active energy curable transparent ink smoothing means 50, an ultraviolet irradiation unit 56 as an active energy irradiation light source is disposed, and the active energy curing whose surface is smoothed by the active energy curable transparent ink smoothing means 50. The mold transparent ink is cured by irradiating with ultraviolet rays. As the ultraviolet irradiation unit 56, for example, a metal halide lamp, a high-pressure mercury lamp, a UV-LED, or the like can be used.

  The die cutter 60 is provided with a cut 1b having a desired label shape only in the adhesive sheet 1 of the recording medium S for label printing of a continuous sheet printed (see FIG. 3). The cylinder cutter 61 and the recording medium And a receiving roller 62 disposed on the opposite side of the cylinder cutter 61 with respect to S. In the cylinder cutter 61, a plurality of cutting blades 61a formed in a label shape are wound around the cylindrical surface of the cylinder 61b.

  The die cutter 60 oscillates and rotates intermittently at a speed synchronized with the conveyance speed of the recording medium S while the recording medium S is sandwiched between the cylinder cutter 61 and the receiving roller 62, so that the cutting blade 61a is recorded. Only the adhesive sheet 1 of the medium S is provided with a label-shaped cut 1b.

  Here, the reason why the die cutter 60 swings and rotates intermittently is to solve the problem caused by the mismatch between the circumferential length of the cylindrical surface of the cylinder 61b and the required length of the cutting blade 61a. That is, when the die cutter 60 is continuously rotated to make the label-shaped cut 1b, the recording medium S corresponding to the portion where the cutting blade 61a of the cylinder cutter 61 does not exist is also fed and the recording medium S is wasted. By turning and rotating the die cutter 60, the cut 1b can be formed continuously, and the recording medium S can be eliminated.

  The scrap removing part 70 peels off an unnecessary part (peripheral part of the label L) of the pressure-sensitive adhesive sheet 1 that does not become the label (product) L from the release paper 2 and discards it. The label L, which is a product, is wound on the product take-up roller 19 together with the release paper 2 in a state of being attached to the release paper 2 to be a product.

  Next, the operation of the ultraviolet curable inkjet head label printer 100 will be described. As shown in FIG. 1, a continuous sheet recording medium S for label printing fed from a supply roll 16 wound up in a roll shape is conveyed to an image forming area 80 by a plurality of conveyance roller pairs 11 and 12. .

  The inkjet heads 21Y, 21M, 21C, and 21B are controlled by a head drive control unit (not shown) and receive UV curable ink from the ink discharge unit at a timing that matches the transport speed of the recording medium S. Discharge toward S. The ink adhering to the recording medium S is immediately irradiated with ultraviolet rays from the ultraviolet irradiation unit 22 to be cured and printed.

  As shown in FIG. 4, the printing portion of the recording medium S is three-dimensionally swelled by overlapping the cured inks 3 of a plurality of colors. The rising height of the ink varies depending on the ink absorbability of the recording medium S (the lower the absorbency and the higher the contact angle of the ink with the base ink, the higher the height), but it is approximately 10 μm per color. When four color inks are used, a situation of approximately 40 μm is created.

  The printed recording medium S is conveyed to the smoothing area 81, and first, the active energy curable transparent ink 4 is applied to the printing surface by the varnish coater 40 so as to cover the entire raised ink 3 (see FIG. 4). ). The application amount of the active energy curable transparent ink 4 is an amount necessary for smoothing the unevenness on the surface of the recording medium S with the active energy curable transparent ink 4, although it varies depending on the height of the ink 3. For example, it is preferably about 5 to 50 μm.

  The recording medium S coated with the active energy curable transparent ink 4 is smoothed by the active energy curable transparent ink 4 being smoothed by the active energy curable transparent ink smoothing means 50. That is, the continuous sheet 55 having water repellency comes into contact with the active energy curable transparent ink 4 applied so as to cover the ink 3, and the active energy curable transparent ink 4 is sandwiched between the recording medium S and activated. The surface of the energy curable transparent ink 4 is smoothed.

  The continuous sheet 55 may be sent at a speed synchronized with the conveyance speed of the recording medium S or may be stopped. Since the continuous sheet 55 has water repellency, when the smoothed portion (surface) of the active energy curable transparent ink 4 moves away from the continuous sheet 55, the smoothness of the active energy curable transparent ink 4 is affected. There is almost no. Further, the active energy curable transparent ink 4 does not adhere to the continuous sheet 55 and become dirty.

  The active energy curable transparent ink 4 whose surface is smoothed by the active energy curable transparent ink smoothing means 50 is immediately irradiated with ultraviolet rays from the ultraviolet irradiation unit 56 and cured.

  The recording medium S whose surface is smoothed in this way is further conveyed to the label removal area 83 via the conveyance buffer area 82, and the cut 1b is formed in the shape of the label L only on the adhesive sheet 1 by the die cutter 60. Can be put.

  At this time, as described above, since the die cutter 60 makes the cut 1b having the shape of the label L while swinging intermittently, the cut 1b can be continuously formed, and the recording medium S is wasted. The part never occurs.

  Unnecessary portions other than the label L of the pressure-sensitive adhesive sheet 1 are peeled off from the release paper 2 and taken up by the residue removing portion 70. On the other hand, the label L is wound on the product take-up unit 19 together with the release paper 2 in a state of being stuck on the release paper 2 to become a product.

  According to the printing surface smoothing device 30 of the present embodiment, the surface of the recording medium S on which an image having an uneven surface is formed by an active energy curable ink such as the ultraviolet curable ink 3, the surface smoothing active energy. It can be covered with the curable transparent ink 4 and smoothed. Thereby, a glossy and high-quality image can be obtained.

  Further, the surface of the active energy curable transparent ink 4 supplied from the varnish coater 40 is brought into contact with the smooth water-repellent surface 55a to spread the active energy curable transparent ink 4 smoothly, and the active energy along the water-repellent surface. Since the curable transparent ink spreads wet, it can be smoothed in a short time without waiting until the active energy curable transparent ink 4 is naturally leveled and the surface irregularities are erased. Thereby, productivity can be improved.

  Furthermore, the active energy curable transparent ink 4 can be stably applied to the surface of the recording medium S on which the uneven image is formed by the varnish coater 40 having a simple and inexpensive mechanism.

  Further, since the smooth flat surface 55a is formed by the continuous sheet 55 stretched between the supply roll 51 and the take-up roll 52, even if the water repellency of the continuous sheet 55 is reduced due to continuous use or the like, a new continuous sheet 55 is obtained. Are successively fed out from the supply roll 51 and exchanged, and the surface of the recording medium S can be stably smoothed by using the continuous sheet 55 that is always excellent in smoothing performance.

  Further, since the transparent ink is an active energy curable transparent ink and the active energy irradiation light source 56 is provided at the position of the active energy curable transparent ink smoothing means 50 or downstream, the active energy curable transparent ink 4 is provided. While smoothing or immediately after smoothing, it can be cured by irradiating active energy from the active energy irradiation light source 56, thereby obtaining a smooth surface with excellent smoothness.

The transport buffer area 82 may be arranged between the image forming unit 20 and the printing surface smoothing device 30 as in the active energy curable inkjet head label printer 101 shown in FIG. If the recording medium S is disposed on the downstream side of the smoothing device 30 (see FIG. 1), the recording medium S can be continuously conveyed also in the printing surface smoothing device 30. The relationship between the arrangement positions of the transfer buffer area 82 is the same in the following embodiments.
(Second Embodiment)

  Next, a second embodiment of the printing surface smoothing apparatus will be described with reference to FIG. FIG. 6 is a schematic configuration diagram of an active energy curable inkjet head label printer to which a printing surface smoothing apparatus according to a second embodiment of the present invention is applied.

  The active energy curable inkjet head label printer 200 of this embodiment is different from the ultraviolet curable inkjet head label printer 100 of the first embodiment in the configuration of the printing surface smoothing device 130. The other parts are the same as those of the ultraviolet curable inkjet head label printer 100 of the first embodiment, and therefore, the same parts are denoted by the same or corresponding reference numerals, and the description is diverted.

  As shown in FIG. 6, the printing surface smoothing device 130 of the ultraviolet curable inkjet head label printing machine 200 to which the printing surface smoothing device 130 of the second embodiment is applied is an active energy curing type on the surface of the recording medium S. An ink jet nozzle 140 is used as cover ink supply means for supplying the transparent ink 4. Further, the ultraviolet irradiation unit 56 is disposed above the continuous sheet 55 spanned between the pair of rollers 53 and 54 of the active energy curable transparent ink smoothing means 50. The continuous sheet 55 is a light transmissive sheet capable of transmitting ultraviolet light, and at least the surface on the recording medium S side has water repellency.

  The recording medium S on which an image is formed by the image forming unit 20 covers the irregularities formed by discharging the active energy curable transparent ink 4 from the inkjet nozzle 140 and curing the ultraviolet curable ink. When the recording medium S reaches the active energy curable transparent ink smoothing means 50, the active energy curable transparent ink 4 is sandwiched between the recording medium S and the continuous sheet 55 and the active energy curable transparent ink 4. Is smoothed. Here, since the continuous sheet 55 transmits ultraviolet rays, the active energy curable transparent ink 4 sandwiched between the recording medium S and the continuous sheet 55 is irradiated with ultraviolet rays through the continuous sheet 55, thereby activating the active energy curable transparent. The ink 4 is cured.

  In this case, since the active energy curable transparent ink 4 is sandwiched between the recording medium S and the continuous sheet 55 and is cured while being blocked from oxygen in the air, the active energy curable transparent ink 4 is in the atmosphere. Even radical inks that are prone to polymerization inhibition by oxygen can inhibit polymerization inhibition and use an inexpensive light source with low light intensity.

  According to the printing surface smoothing device 130 of the present embodiment, since the cover ink supply means is the inkjet 140, the recording medium on which an uneven image is formed while the supply amount of the active energy curable transparent ink 4 is controlled. The active energy curable transparent ink 4 can be supplied to the surface of S. As a result, a high-quality image with a smooth surface and uniform gloss can be obtained with a small amount of the active energy curable transparent ink 4.

  Further, since the continuous sheet 55 is a light transmitting sheet, the continuous sheet 55 is brought into contact with the surface of the active energy curable transparent ink 4 so that the active energy curable transparent ink 4 is spread out smoothly. It can be cured by irradiation with active energy. As a result, the active energy curable transparent ink 4 can be cured in a state where the contact between the active energy curable transparent ink 4 and the air is blocked. However, inhibition of polymerization can be suppressed, and an inexpensive light source 56 with low light intensity can be used.

Other configurations and operations are the same as those of the active energy curable inkjet head label printing machine according to the first embodiment, and the description will be used.
(Third embodiment)

  Next, the printing surface smoothing apparatus of 3rd Embodiment is demonstrated based on FIG. FIG. 7 shows an active energy curable ink jet head label in which the smoothing area 81 and the label removal area 83 of the first and second embodiments are integrated as a post-processing device and are independent and provided separately from the image forming area 80. It is a schematic block diagram of a printing apparatus.

  As shown in FIG. 7, the post-processing device 151 configured to include the printing surface smoothing device 150, the die cutter 60, the scraping unit 70, and the product winding unit 19 is configured as a device independent of the image forming unit 20. Has been. The printing surface smoothing device 150 includes the varnish coater 40 already described in the first embodiment, the active energy curable transparent ink smoothing means 50 and the ultraviolet irradiation unit 56 already described in the second embodiment.

  Other than that, since it is the same as the digital label printing apparatus 200 of the second embodiment, the same reference numerals are assigned to the same portions, and the description is diverted.

  In the active energy curable inkjet head label printing apparatus 300, first, ultraviolet curable ink is ejected toward the recording medium S from the ink ejection portions of the inkjet heads 21Y, 21M, 21C, and 21B of the image forming unit 20, and ultraviolet irradiation is performed. The portion 22 is printed by being irradiated with ultraviolet rays.

  The printed recording medium S is transferred to the post-processing device 151, the active energy curable transparent ink 4 is applied by the varnish coater 40, and the active energy curable transparent ink 4 is further applied by the active energy curable transparent ink smoothing means 50. Is smoothed and cured by being irradiated with ultraviolet rays from the ultraviolet irradiation unit 56. Then, the cut 1b is made in the shape of the label L only in the pressure-sensitive adhesive sheet 1 by the die cutter 60 (see FIG. 3). On the other hand, the label L is wound on the product take-up unit 19 together with the release paper 2 in a state of being stuck on the release paper 2 to become a product.

  According to the digital label printing apparatus 300 of the present embodiment, since the image forming unit 20 and the post-processing apparatus 151 are configured as separate and independent apparatuses, the label L printing process and the printing surface smoothing are performed. Post-processes such as processing and scrap removal can be performed as separate operations, and post-processes of various types of labels L can be performed together.

  In general, the time required for printing is often slower than the time required for post-processing such as scrap removal, and a single post-processing device 151 can handle a plurality of image forming units 20. Efficient processing is possible.

Since other configurations and operations are the same as those of the active energy curable inkjet head label printer of the second embodiment, the description is diverted.
(Fourth embodiment)

  Next, a fourth embodiment of the printing surface smoothing apparatus will be described with reference to FIG. FIG. 8 is a schematic configuration diagram of an active energy curable inkjet head label printer to which a printing surface smoothing apparatus according to a fourth embodiment of the present invention is applied.

  The active energy curable inkjet head label printer 400 of this embodiment is different from the ultraviolet curable inkjet head label printer 100 of the first embodiment in the configuration of the printing surface smoothing device 180. The other parts are the same as those of the ultraviolet curable inkjet head label printer 100 of the first embodiment, and therefore, the same parts are denoted by the same or corresponding reference numerals, and the description is diverted.

  As shown in FIG. 8, the printing surface smoothing device 180 of the fourth embodiment applied to the ultraviolet curable inkjet head label printer 400 is a cover for supplying the active energy curable transparent ink 4 to the surface of the recording medium S. A varnish coater 40 is used as ink supply means. Further, as the active energy curable transparent ink smoothing means 180, a smooth flat surface 155a is formed by a belt 155 that is mounted in a loop between two rollers 153 and 154 disposed in parallel with the recording medium S. Yes. The belt 155 is a belt capable of transmitting ultraviolet rays, and at least the surface on the recording medium S side has water repellency.

  The ultraviolet irradiation unit 56 is disposed inside the loop belt 155, and the active energy curable transparent ink 4 sandwiched between the recording medium S and the belt 155 (smooth plane 155 a) via the belt 155. The active energy curable transparent ink 4 is cured by irradiating with UV light.

  In the ultraviolet curable ink jet head label printer 400 configured as described above, the recording medium S on which the image is formed by the image forming unit 20 is applied with the active energy curable transparent ink 4 by the varnish coater 40. The active energy curable transparent ink 4 is smoothed by being sandwiched between the recording medium S and the belt 155.

  The smoothed active energy curable transparent ink 4 is sandwiched between the recording medium S and the belt 155 and is shielded from oxygen in the air through the light transmitting belt 155 from the ultraviolet irradiation unit 56. The active energy curable transparent ink 4 is cured by being irradiated with ultraviolet rays. Therefore, even if the active energy curable transparent ink 4 is a radical-based ink that easily causes polymerization inhibition due to oxygen in the atmosphere, polymerization inhibition can be suppressed.

  According to the printing surface smoothing apparatus 180 of the present embodiment, the active energy curable transparent ink smoothing means 180 forms the smooth flat surface 155a by the belt 155 that is bridged between at least two rollers 153 and 154. Therefore, the wide smooth plane 155a can be configured with a simple mechanism.

  Further, since the belt 155 is a light transmission belt, it can be cured by irradiation with active energy from above the belt 155 contacting the surface of the active energy curable active energy curable transparent ink 4. Thus, the active energy curable transparent ink 4 can be cured in a state where contact between the air and the air is blocked, and the active energy curable active energy curable transparent ink 4 is a radical system in which polymerization is inhibited by oxygen in the atmosphere. Even with ink, polymerization inhibition is suppressed, and an inexpensive light source 56 with low light intensity can be used.

Other configurations and operations are the same as those of the active energy curable inkjet head label printing machine according to the first embodiment, and the description will be used.
(Fifth embodiment)

  Next, a fifth embodiment of the printing surface smoothing apparatus will be described with reference to FIG. FIG. 9 is a schematic configuration diagram of an active energy curable inkjet head label printer to which a printing surface smoothing apparatus according to a fifth embodiment of the present invention is applied.

  The active energy curable inkjet head label printer 500 of the present embodiment is different from the ultraviolet curable inkjet head label printer 100 of the first embodiment in the configuration of the printing surface smoothing device. The other parts are the same as those of the ultraviolet curable inkjet head label printer 100 of the first embodiment, and therefore, the same parts are denoted by the same or corresponding reference numerals, and the description thereof is simplified or omitted.

  As shown in FIG. 9, the printing surface smoothing device 170 of the fifth embodiment applied to the ultraviolet curable ink jet head label printer 500 is a cover for supplying the active energy curable transparent ink 4 to the surface of the recording medium S. A varnish coater 40 is used as ink supply means. Further, a drum 171 is used as the active energy curable transparent ink smoothing means, and the axis 155a of the drum 171 contacting the surface (printing surface) of the recording medium S forms a smooth line and is applied. The energy curable transparent ink 4 is smoothed. The surface 171b of the drum 171 has water repellency.

  The ultraviolet irradiation unit 56 is disposed on the downstream side of the drum 171 and irradiates the active energy curable transparent ink 4 smoothed by the drum 171 with ultraviolet rays to be cured.

  In the ultraviolet curable inkjet head label printer 500 configured as described above, the recording medium S on which the image is formed by the image forming unit 20 is applied after the active energy curable transparent ink 4 is applied by the varnish coater 40. Then, the recording medium S comes into contact with the drum 171 and the active energy curable transparent ink 4 is smoothed by the axis 155a. And it hardens | cures with the ultraviolet-ray irradiated from the ultraviolet irradiation part 56. FIG. In addition, the drum 171 is used as a light transmissive drum, and an active energy irradiation unit is disposed inside the drum, and the active energy is irradiated from the inner surface of the drum 171 in contact with the surface of the active energy curable active energy curable transparent ink 4. It can be cured. Thus, the active energy curable transparent ink 4 can be cured in a state where contact between the air and the air is blocked, and the active energy curable active energy curable transparent ink 4 is a radical system in which polymerization is inhibited by oxygen in the atmosphere. Even with ink, polymerization inhibition is suppressed, and an inexpensive light source with low light intensity can be used.

  According to the printing surface smoothing device 170 of the present embodiment, the active energy curable transparent ink smoothing means forms a smooth line by the axis 155a on the surface of the drum 171. Therefore, the active energy curable transparent ink smoothing means is simplified. Can be

  Since other configurations and operations are the same as those of the active energy curable inkjet head label printer 100 of the first embodiment, the description will be used.

  In addition, this invention is not limited to each embodiment and modification which were mentioned above, A deformation | transformation, improvement, etc. are possible suitably.

  In the present invention, the printing surface smoothing device has been described as being applied to an ultraviolet curable ink jet head label printer. However, the present invention is not limited to this, and an active energy curable transparent ink is applied as a post-treatment. The present invention can be applied to any type of printing press and has the same effect.

  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. Therefore, 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. An irradiation energy of / cm ² is appropriate. The active energy exposure surface illuminance (the maximum illuminance of the surface of the recording medium) is, for example, 10 to 2,000 mW / cm ^2, preferably, suitably be irradiated at 20 to 1,000 mW / cm ² is there.
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 of 10 to 1,000 mW / cm ^{2 on the} surface of the recording medium. The light emitting diode is preferably irradiated.

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, 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. Moreover, it is preferable that the head unit to be heated is thermally shielded or insulated so that the apparatus main body is not affected by the temperature from the outside 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. Further, 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 emit 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 the various plastic films include PET film, OPS film, OPP film, ONy film, PVC film, PE film, and TAC film. In addition, examples of the plastic that can be used as the 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 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 alkylene oxide adducts thereof, 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 thereof 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 therein 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.

  Examples of such a photoacid generator include an onium salt such as a diazonium salt, an ammonium salt, a phosphonium salt, an iodonium salt, a sulfonium salt, a selenonium salt, and 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 sulfonic 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 (quinoline yellow lake, etc.); 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 (Mada 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 the white pigment include basic lead carbonate (2PbCO ₃ Pb (OH) ₂ , so-called silver white), zinc oxide (ZnO, so-called zinc white), titanium oxide (TiO ₂ , so-called titanium white), Strontium titanate (SrTiO ₃ , so-called titanium strontium white) or the like 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 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 cationically polymerizable compound is used, and among them, it is preferable to select a cationically polymerizable monomer having the lowest viscosity in terms of dispersion suitability and handling properties 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.
Selection of pigments, dispersants, and dispersion media, dispersion conditions, and filtration conditions are set so that the average particle diameter of the pigment particles falls within the above preferred 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. Accordingly, so-called water-insoluble oil-soluble dyes are 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 paragraphs [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 listed as preferable examples, and specific examples include paragraph numbers [0052] to [0066] in 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.
Although the addition amount is appropriately selected according to the purpose, it is generally about 0.5 to 15% by mass in terms of solid content.

[Sensitizer]
If necessary, a sensitizer may be added to the ink composition of the present invention 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, and 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, page 527, ibid. No. 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. Examples of polymer 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 a tackifier, specifically, a high molecular weight adhesive polymer (for example, (meth) acrylic acid and an alkyl group having 1 to 20 carbon atoms) described in JP-A-2001-49200, 5-6p. An ester with an alcohol having, an ester of (meth) acrylic acid and an alicyclic alcohol having 3 to 14 carbon atoms, a copolymer comprising an ester of (meth) acrylic acid and an aromatic alcohol having 6 to 14 carbon atoms) Or 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 compounds having addition-polymerizable ethylenically unsaturated bonds that can be used in the ink composition of the present invention include unsaturated carboxylic acids (eg, 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 Sorbitol tetritaconate, etc.

  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 amide monomers of aliphatic polyvalent amine compounds and unsaturated carboxylic acids 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.

As another example, a vinyl compound containing a hydroxyl group represented by the following general formula (A) is added to a polyisocyanate compound having two or more isocyanate groups per molecule described in JP-B-48-41708. Examples thereof include vinyl urethane compounds containing two or more polymerizable vinyl groups in one molecule to which a monomer is added. CH ₂ = C (R) COOCH ₂ CH (R ′) OH (A) (where R and R ′ represent H or CH ₃ )
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 may 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 colorant as (c) 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]
Further, 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. Specific examples 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. 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 glycols and polyol acrylates (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 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 represents — (CH ₂ ) _x — (x = 0 or 1), —O— (CH ₂ ) _y — (y = 1 or 2), substituted or unsubstituted Represents a phenylene 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.

  Furthermore, in the present invention, a water-soluble derivative (hereinafter abbreviated as 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 color 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 coloring material, the concentration of the polymerization initiator and the polymerizable substance in the ink can be adjusted according to the absorption characteristics of the contained coloring material. preferable. As described above, the amount of water or solvent is in the range of 40% to 90%, preferably in the range of 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%, based on the mass, with respect to the total amount of the ink. The polymerization initiator depends on the content of the polymerizable compound, but 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 color material of the ink, 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 concentration 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 40 mN / m or less is preferable in terms of wettability.

The ink composition of the present invention thus adjusted is suitably used as an ink for inkjet recording. When used as an ink for inkjet recording, the ink composition is ejected onto a recording medium by an inkjet 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.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram of the active energy curing type inkjet head label printing machine suitable for applying the printing surface smoothing apparatus which is 1st Embodiment of this invention. FIG. 2 is a perspective view of an image forming unit in FIG. 1. It is a longitudinal cross-sectional view of the recording medium for label printing. It is a conceptual diagram which shows the state by which the surface of the recording medium which is printed and has an unevenness | corrugation is smoothed with active energy curable transparent ink. It is a schematic block diagram of the active energy curable inkjet head label printer of the modification. It is a schematic block diagram of the active energy curing type inkjet head label printing machine suitable for applying the printing surface smoothing apparatus which is 2nd Embodiment of this invention. FIG. 2 is a schematic configuration diagram of an active energy curable inkjet head label printing apparatus in which a smoothing area and a label removal area are integrated and provided independently from an image forming area. It is a schematic block diagram of the active energy curable inkjet head label printer to which the printing surface smoothing apparatus which is 4th Embodiment of this invention was applied. It is a schematic block diagram of the active energy curable inkjet head label printer to which the printing surface smoothing apparatus which is 5th Embodiment of this invention was applied.

Explanation of symbols

4 Active energy curable transparent ink (Active energy curable transparent ink)
30 Printing surface smoothing device 40 Varnish coater (cover ink supply means)
50 Active energy curable transparent ink smoothing means 51 Supply roll 52 Winding roll 55 Continuous sheet 55a Smooth flat surface (water repellent surface)
56 UV irradiation part (active energy irradiation light source)
130 Print Surface Smoothing Device 140 Inkjet Nozzle (Cover Ink Supply Unit)
150 liters of recording medium for printing)

Claims (9)

In a printing surface smoothing apparatus that performs post-processing of surface smoothing after recording on a recording medium for printing,
Cover ink supply means for supplying active energy curable transparent ink to the surface of the recording medium after printing;
The active energy curable transparent ink is disposed downstream of the cover ink supply means in the transport direction of the recording medium for printing, and has a smooth water-repellent surface in contact with the active energy curable transparent ink surface of the recording medium surface. An active energy curable transparent ink smoothing means that spreads smoothly;
A printing surface smoothing apparatus comprising:   The printing surface smoothing apparatus according to claim 1, wherein the cover ink supply unit is a varnish coater.   The printing surface smoothing apparatus according to claim 1, wherein the cover ink supply unit is an inkjet.   The printing according to any one of claims 1 to 3, wherein the active energy curable transparent ink smoothing means forms a smooth plane by a continuous sheet stretched between a supply roll and a take-up roll. Surface smoothing device.   The printing surface smoothing according to any one of claims 1 to 3, wherein the active energy curable transparent ink smoothing means forms a smooth plane by a belt stretched between at least two rollers. apparatus.   The printing surface smoothing device according to any one of claims 1 to 3, wherein the active energy curable transparent ink smoothing means forms a smooth line by an axis of the drum surface.   The active energy curable transparent ink is an active energy curable type, and an active energy irradiating light source is provided at a position or downstream of the active energy curable transparent ink smoothing means. The printing surface smoothing apparatus as described.   The printing surface smoothing device according to claim 7, wherein the continuous sheet is a light transmission sheet.   The printing surface smoothing device according to claim 7, wherein the belt is a light transmission belt.

Images