JP2008105417A - Image formation apparatus and label printing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image formation apparatus or a label printing apparatus which is applied to a printing step such as a label printing step in which a plurality of printing objects are successively checked. <P>SOLUTION: The image formation apparatus and the label printing apparatus using it includes an image formation means which forms a plurality of images on the surface of a recording medium of continuous paper, a defective printing detection means which detects defectively printed images among the plurality of images formed by the image formation means, and a defective printing marking means which marks the detected defectively printed images. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus and a label printing apparatus.

For example, conventionally, label printing has been performed by various printing methods such as flexographic printing, offset printing, letterpress printing, etc., but in recent years, electrophotographic technology or inkjet technology has been used due to the demand for smaller lots and reduced waste paper. The digital printing method is increasingly used.
Here, as an image forming apparatus using an ink jet head, for example, in Japanese Patent Application Laid-Open No. H10-260260, two colors are used in an ink jet recording method in which an ink having a compound curable by actinic rays is printed on a recording medium by an ink jet method and cured. There is described an ink jet recording apparatus using an ink jet recording method in which an image is formed with the above ink and all the ink necessary for image formation is ejected and the active light is irradiated within 10 seconds.
Patent Document 1 describes that any multi-channel inkjet head known in the art can be used as the inkjet head.

  Along with the digitization of such printing, the flow of digitization has also extended to the post-process of label printing, and laser digital punching machines have been put into practical use. According to laser processing, the degree of freedom of the punching shape is greatly improved, so that the label shape is required to be a complicated shape from a simple shape such as a conventional square or circle.

JP 2003-11341 A

  Here, as the digital label printing apparatus, for example, as shown in Japanese Patent Application No. 2006-116743 “Digital Label Printing Apparatus” by the present applicant, a digital image is printed on a continuous paper-like recording medium for label printing. In a digital label printing apparatus comprising: an image forming unit that forms an image based on a signal; and a post-processing unit that performs post-processing on a recording medium after recording, based on label edge data of the digital image signal There has been proposed a digital label printing apparatus having post-processing process transport speed changing means for changing the transport speed in accordance with the position on the label to be processed in the post-processing means.

  In this digital label printing apparatus, the post-processing step further includes a die-cut for cutting the label shape and an unnecessary part peeling portion for removing other than the label portion, and the post-processing step transport speed changing means is the label shape data. The recording medium conveyance speed is slowed at the label part position that is vulnerable to unnecessary part peeling, or the post-processing step is composed of a laser cutter part and an unnecessary part peeling part that removes other than the label part, and the post-processing process conveyance speed. It has also been proposed that the changing means slows the recording medium conveyance speed in a portion where the density of the image density data at the label edge is high.

  By the way, the labels printed by the digital label printing apparatus as described above are not necessarily in a printing state that all labels (labels) should satisfy, and some of them are defective in ink ejection in the ink jet printing method. In some cases, there may be a quality defect due to the occurrence of a printing defect due to.

  In such a case, the inspection personnel placed in the subsequent stage of the digital label printing apparatus usually inspects the entire label continuously by visual inspection. The repair work by manual work of peeling off the non-defective product and attaching a pre-prepared good product (that is, a label in a satisfactory printing state) to the position has been performed.

However, in this inspection work, it is generally difficult to completely eliminate inspection mistakes, that is, oversight of defective products, because it is generally necessary to inspect each label printed in multiple rows by visual inspection. However, the problem of increased fatigue of the monitoring personnel could not be solved easily.
This type of problem is not limited to label printing, and is a problem that occurs when a plurality of printed materials on which the same image is printed are continuously inspected.

  The present invention has been made in view of the above circumstances, and an object thereof is to solve the problems in the prior art and easily apply printing defects that are applied to continuously inspect a plurality of printing objects. An object of the present invention is to provide an image forming apparatus or a label printing apparatus that can be confirmed or automatically detected, can reduce the burden on an operator, and can produce high-quality printed matter with high production efficiency.

In order to achieve the above object, an image forming apparatus according to the present invention includes an image forming unit that forms a plurality of images on the surface of a continuous paper-like recording medium, and a plurality of images formed by the image forming unit. It is characterized by having a printing failure detection means for detecting a printing failure image and a printing failure marking means for marking the detected printing failure image.
Here, it is preferable that the image forming unit is an ink jet head using an ink curable by irradiation with active energy.

Here, it is preferable that the printing defect detection unit is configured to detect ejection defects of the inkjet head.
Further, the image forming unit forms the plurality of images on the surface of the continuous paper-like recording medium based on drawing image data stored in advance, and the printing defect detection unit includes the image Used to form the image in the first image data obtained by reading the images in the plurality of images formed on the continuous paper-like recording medium surface by the forming unit and the drawing image data. It is preferable that the comparison with the second image data is performed to detect whether the image recorded on the surface of the continuous paper-like recording medium is normal.

  Further, the image forming unit stores in advance drawing image data used to form the plurality of images on the surface of the continuous paper-like recording medium, and the continuous paper-like target is recorded by the image forming unit. Image detection means for obtaining first image data by reading images in the plurality of images formed on the surface of the recording medium, wherein the printing defect detection means is the image of the image read by the image detection means. The first image data and the second image data used for forming the image in the drawing image data are compared, and the image recorded on the surface of the continuous paper-like recording medium is It is preferable to detect whether the image is a normal image or the poorly printed image.

  According to another aspect of the present invention, there is provided a label printing apparatus that performs post-processing on the surface of the continuous recording medium on which the plurality of images are formed by the image forming apparatus and the image forming unit of the image forming apparatus. And the plurality of images formed by the image forming means are a plurality of label images, and the images are label images.

Note that it is preferable that the transport speed of the recording medium is changed in accordance with the processing position on the label in the post-processing means based on the edge shape data of the label image.
Further, the post-processing means has a laser cutter for cutting a label shape and an unnecessary portion peeling portion for removing unnecessary portions other than the label portion, and is covered at a portion where the image density at the edge of the label image is high. It is preferable to have a conveyance speed control means for changing the conveyance speed of the recording medium.
Furthermore, the post-processing means has a laser cutter for cutting a label shape and an unnecessary part peeling part for removing unnecessary parts other than the label part, and for the label image marked by the printing defect marking means, It is preferable to have a laser cutter control means for controlling not to cut the label portion edge by the laser cutter.

  According to the present invention, even when it is necessary to continuously inspect a plurality of print objects, it is possible to easily confirm or automatically detect a print defect, reduce the burden on the operator, and There is a remarkable effect that an image forming apparatus or a label printing apparatus capable of producing a high-quality printed matter with high production efficiency can be realized.

  More specifically, according to the present invention, in an image forming apparatus or a label printing apparatus that continuously inspects a plurality of print objects, an inspection error, that is, an oversight of defective products can be reduced or completely prevented. It is possible to obtain a very practical effect that the sorting operation can be simplified or performed automatically.

Hereinafter, an image forming apparatus and a label printing apparatus according to the present invention will be described in detail based on preferred embodiments shown in the drawings.
In the following embodiments, the present invention will be described by taking a digital label printing apparatus using an inkjet recording apparatus as an image forming apparatus as a representative example, but the present invention is not limited to this.
The digital label printing apparatus according to the present embodiment cures only the inside of the undercoat liquid applied to the recording medium, and is cured by irradiation with active energy rays on the undercoat liquid film cured only inside. The ink is ejected to form an image.

  FIG. 1A is a front view showing a schematic configuration of an example of a digital label printing apparatus of the present invention using an ink jet recording apparatus according to an embodiment of the image forming apparatus of the present invention, and FIG. FIG. 2 is a partially enlarged view of another configuration example of the inkjet head of the digital label printing apparatus shown in FIG. 1A, and FIG. 2 is a block diagram showing a control unit that controls the digital label printing apparatus shown in FIG. FIG. 3 is a longitudinal sectional view of the recording medium P for label printing used in the digital label printing apparatus shown in FIG.

The digital label printing apparatus 100 according to the present embodiment records an image on a continuous paper-like recording medium for label printing (hereinafter also simply referred to as “recording medium”) P by the drawing unit 102, and then performs a post-processing unit 108. This is an embodiment in which a scrap removal operation is performed as a post-process in which a label-shaped cut is made by the die cutter, and an unnecessary portion of the adhesive sheet is peeled off and removed from the mount (release paper).
In each of the following embodiments, an active energy curable digital label printing apparatus that uses an ultraviolet curable ink among active energy curable inks that are cured by active energy irradiation will be described as an example. The present invention is not limited, and the present invention can be applied to a digital label recording apparatus using various active energy curable inks, and any other type of digital label printing apparatus.
Further, as shown in FIG. 3, the recording medium P shown in the present embodiment has a two-sheet structure in which an adhesive sheet 180 coated with an adhesive 180a on the back surface is superposed on a release paper 182 as a mount. Is.

As shown in FIG. 1, the digital label printing apparatus 100 includes an image recording unit (drawing unit) 102 to which the image forming apparatus of the present invention is applied, a smoothing unit 104, a foil pressing unit 106, a post-processing unit 108, and a conveyance Unit 110 and control unit 112.
Here, the transport unit 110 transports the recording medium P in a certain direction (from left to right in FIG. 1), and includes an image recording unit 102, a smoothing unit 104, a foil pressing unit 106, and a post-processing unit. 108 are arranged in this order in the transport direction of the recording medium P, that is, from upstream to downstream. The control unit 112 is connected to the image recording unit 102, the smoothing unit 104, the foil pressing unit 106, the post-processing unit 108, and the transport unit 110, and controls the operation of each unit.

The conveyance unit 110 includes a supply roll 122, conveyance roller pairs 126, 128, 130, and 132, a product winding unit 134, and conveyance motors 126a and 134a.
The supply roll 122 is obtained by winding the recording medium P in a roll shape.
The conveyance roller pairs 126, 128, 130, and 132 are arranged in this order from the upstream to the downstream of the conveyance path of the recording medium P. The transport roller pairs 126, 128, 130, and 132 feed the recording medium P from the supply roll 122 and transport the recording medium P in a predetermined direction (in this embodiment, from left to right in FIG. 1). .
The product winding unit 134 is disposed on the transport path of the recording medium P, that is, the most downstream in the transport direction, and is transported on the transport path by the pair of transport rollers 126, 128, 130, and 132, and the image recording unit 102 is smoothed. The recording medium P that has passed through the section 104, the foil pressing section 106, and the post-processing section 108 is taken up.
The conveyance motors 126a and 134a are connected to the conveyance roller pair 126 and the product winding unit 134, respectively, and rotationally drive the conveyance roller pair 126 and the product winding unit 134.

That is, in this embodiment, the conveyance roller pair 126 and the product winding unit 134 connected to the conveyance motors 126a and 134a are rotationally driven to become drive rollers for conveying the recording medium P, and the other conveyance roller pairs 128, Reference numerals 130 and 132 are driven rollers that rotate according to the movement of the recording medium P and regulate the recording medium P on the transport path.
The conveyance unit 110 drives the conveyance motors 126 a and 134 a and rotationally drives the conveyance roller pair 126 and the product winding unit 134. As a result, the recording medium P is unwound from the supply roll 122, passes through the image recording unit 102, the smoothing unit 104, the foil pressing unit 106, and the post-processing unit 108, and is wound around the product winding unit 134.

In the present embodiment, a conveyance buffer is provided between the image recording unit 102 and the smoothing unit 104 and between the foil pressing unit 106 and the post-processing unit 108.
By providing such a transport buffer, slack of the continuous paper-like recording medium P for label printing caused by the difference in transport speed between the image recording unit 102 and the smoothing unit 104, and the foil pressing unit 106 and the post-processing unit 108 is eliminated. The label can be produced efficiently.

The conveyance motors 126a and 134a are connected to a control unit 112, which will be described later, to control the rotation speed, and the conveyance speed of the recording medium P for continuous sheet-like label printing by the conveyance unit 110 is controlled.
The pair of transport rollers as the drive roller pair is not particularly limited. For example, all the transport roller pairs may be provided with a transport motor, and all the transport roller pairs may be used as the drive roller pairs.

The image recording unit 102 includes an undercoat liquid film forming unit 114, a recording head unit 135 that is an image forming unit of the present invention, ultraviolet irradiation units 138 and 139, and an image detection unit 140 that is a printing defect detection unit of the present invention. And a defective printing marking portion 142.
The recording head unit 135 has recording heads (inkjet heads) 136Y, 136C, 136M, and 136K, and the position facing the transport path of the recording medium P, that is, the front end of the ink ejection unit faces the recording medium P. Has been placed.

As described above, the digital label printing apparatus 100 according to the present embodiment cures only the inside of the undercoat liquid applied to the recording medium P, and on the undercoat liquid film obtained by curing only the inside of the undercoat liquid, Image formation is performed by discharging at least one kind of ink that is cured only inside by irradiation.
Here, the undercoat liquid film forming unit 114 includes a roll coater 116 that applies the undercoat liquid to the surface of the recording medium P and an internal curing ultraviolet irradiation unit 118 that cures only the inside of the undercoat liquid after application. It is said. The undercoat liquid film forming unit 114 cures at least one type of undercoat liquid applied to the recording medium P, and only the inside of the undercoat liquid is cured. Image formation is performed by discharging various types of ink.
Note that the means for applying the undercoat liquid is not limited to the roll coater 116, and various methods such as spray coater and application using an ink jet can be used. As the ultraviolet irradiation unit 118, various ultraviolet light sources such as a metal halide lamp, a high-pressure mercury lamp, and a UV LED can be used.

  Here, “internal curing” in the present invention refers to a state in which the inside of the undercoat liquid is completely or partially cured, and the surface has a fluidity lower than the internal degree of curing. Specifically, after the completion of the internal curing process (for example, after irradiation with active energy rays or after heating) and before the ink droplet is ejected, a penetrating medium such as plain paper is pressed against this permeation. It can be determined by whether or not the surface of the undercoat liquid has been transferred to the sexual medium.

The recording heads 136Y, 136C, 136M, and 136K are arranged in the order of the recording head 136Y, the recording head 136C, the recording head 136M, and the recording head 136K from the upstream to the downstream in the conveyance direction of the recording medium P.
The recording heads 136Y, 136C, 136M, and 136K have a large number of ejection ports (nozzles, inks) at regular intervals in a direction orthogonal to the conveyance direction of the recording medium P, that is, in the entire width direction of the recording medium P. This is a full-line type and piezo-type ink jet head in which a discharge unit is disposed, and is connected to a head drive control unit 192 of the control unit 112 described later and an ink storage / loading unit (not shown). In the recording heads 136Y, 136C, 136M, and 136K, the ejection amount and ejection timing of the ink droplets are controlled by the head drive control unit 192.
A color image is formed on the surface of the recording medium P by ejecting the respective color inks from the recording heads 136Y, 136C, 136M, and 136K toward the recording medium P while conveying the recording medium P by the transport unit 110. can do.

In this embodiment, the recording head is not limited to the piezo element (piezoelectric element) method, but instead of the piezo method, the ink is heated by a heating element such as a heater to generate bubbles, and the ink droplets are generated by the pressure. Various methods such as a flying thermal jet method can be applied.
Note that the ink ejected from the recording heads 136Y, 136C, 136M, and 136K of the present embodiment is an ultraviolet curable ink.

The ultraviolet irradiation unit 138 is an active energy irradiation light source, and is disposed on the downstream side of each recording head 136Y, 136C, 136M corresponding to each recording head 136Y, 136C, 136M. The ultraviolet irradiation unit 139 is disposed on the downstream side of the recording head 136K. As the ultraviolet irradiation units 138 and 139, various ultraviolet light sources such as a metal halide lamp, a high-pressure mercury lamp, and a UV LED can be used.
The ultraviolet irradiation units 138 and 139 pass the recording positions facing the recording heads 136Y, 136C, 136M, and 136K, and irradiate the recording medium P on which the image is formed with ultraviolet rays.

  Here, the ultraviolet irradiation unit 138 gives the ink on the surface of the recording medium P the energy for curing only the inside immediately after the ink ejected from the recording head and riding on the surface of the recording medium P, and the recording medium The ink on the P surface is cured. In addition, the ultraviolet irradiation unit 139 further completes the undercoat liquid layer cured only by the ultraviolet irradiation unit 118 and the ink layers of the respective colors cured only by the ultraviolet irradiation unit 138 formed thereon. Harden. That is, the image recording unit 102 of the digital label printing apparatus 100 according to the present embodiment employs such a curing process.

Here, the ultraviolet irradiation units 138 and 139 irradiate the emitted ultraviolet rays to the ink on the surface of the recording medium P and do not irradiate the ink ejection ports of the recording heads 136Y, 136C, 136M, and 136K. A configuration is preferable. In this way, by preventing the ink ejection port from being irradiated with ultraviolet rays, it is possible to prevent the ink from being cured at the ejection port.
Further, it is preferable to perform a light reflection prevention treatment (for example, a matte black treatment) on each of the portions near the ultraviolet irradiation portions 138 and 139.

An image detection unit 140 and a print defect marking unit 142 are disposed following the recording head unit 135 in the image recording unit 102.
The image detection unit 140 includes, for example, an imaging unit that uses a CCD, and compares the read image data with the drawing image data stored in advance in the control unit 112, as will be described later. This is used to detect whether or not the image recorded on the surface of the recording medium P is normal.

  Here, the detection of whether or not the recorded image is normal performed in the control unit 112 is based on the comparison result between the read image data and the drawing image data. Calculation may be performed based on the calculated degree of coincidence or mismatch. For example, the error rate in the image is calculated as the degree of inconsistency from the comparison result of the two image data for one image, and if the error rate is equal to or higher than a predetermined threshold level set in advance, the image is not normal, that is, printing failure It can be detected as an image. The degree of coincidence may be obtained from the error rate instead of the degree of inconsistency such as an error rate, and may be detected as a defective print image when it is below a predetermined threshold level. It should be noted that the predetermined threshold level for detecting whether the image is a normal print image or a defective print image may be determined as appropriate by obtaining in advance an allowable error rate or the like according to the target print image.

  When the image detected by the image detection unit 140 is not a normal image that matches the drawing image, that is, the image detected by the image detection unit 140 is a defective print image. In this case, it is constituted by an ink jet recording head for drawing a marking (for example, a red x mark) indicating the fact on the defective print image.

  Note that the point that the image detection unit 140 is configured by an imaging unit using a CCD and the point that the printing defect marking unit 142 is configured by an inkjet recording head are only examples, and the present invention is not limited thereto. Needless to say, other configuration methods may be used.

Here, instead of or in addition to the image detection unit 140 that detects defective print images, the ink of the recording heads 136Y, 136C, 136M, and 136K of the recording head unit 135 in the image recording unit 102 is used. For example, a recording head ejection failure detection unit 141 (see FIG. 1B) may be provided for detecting the ejection state, for example, detecting whether or not ink ejection is performed normally. The ejection failure detection unit 141 may be provided in one or more recording heads, but is preferably provided in all the recording heads 136Y, 136C, 136M, and 136K.
As such an ejection failure detection unit 141, for example, a light emitting / receiving element, for example, a light emitting element such as an LD or an LED, sandwiching a flying region or a flying path of an ink droplet from the recording head 136 </ b> Y (136 </ b> C, 136 </ b> M, 136 </ b> K). A recording head 136 </ b> Y (136 </ b> C) is provided by arranging a light source and a light receiving sensor such as a light receiving element, and irradiating a flying region or a flying path with laser light or emitted light and detecting transmitted light while recording one image. , 136M, 136K) can be used. For example, an image recording signal, that is, an ejection signal is input when light emission light such as laser light is continuously emitted into the flying region or flying path of an ink droplet of a recording head that is recording one image. Nonetheless, when the transmitted laser beam is detected and the laser beam is not blocked, that is, when the transmitted beam is detected and the light blocking signal synchronized with the discharge signal is not detected, it is detected that the ejection failure has occurred. Is mentioned.
Note that also in the ejection failure detection in the control unit 112, the light blocking signal during recording of one image is counted by the optical sensor of the ejection failure detection unit 141, and the count number is the image detection control unit 197 in the control unit 112. In the image detection control unit 197, the ratio of the sent count number to the pulse number of the ejection signal of the recording head is calculated as an ejection rate (matching degree), and the calculated ejection rate (matching degree) is set in advance. If it is equal to or lower than the predetermined threshold level, it is detected as an ejection failure of the recording head, and the one image can be detected as an ejection failure image. Also in this case, the degree of inconsistency is calculated from the discharge rate, and if it is equal to or higher than a predetermined threshold level, it may be detected as a defective discharge image. The predetermined threshold level for detecting a defective print image may be determined as appropriate by obtaining in advance the count number, the discharge rate, etc., of an acceptable light blocking signal according to the target print image.

  The smoothing unit 104 is disposed after the image detection unit 140 and the defective printing marking unit 142. The smoothing unit 104 is disposed on the downstream side of the drawing unit in the transport direction of the recording medium P, and is transparent on the surface of the recording medium P (ultraviolet in the present embodiment) curable liquid (hereinafter referred to as “active energy”). A varnish coater 143 which is a transparent liquid supply means for supplying a “curable transparent liquid” or simply “transparent liquid”) and an ultraviolet irradiation section 148 which is an active energy irradiation means for irradiating the transparent liquid with active energy to cure. And have.

The varnish coater 143 includes a pair of application rolls 144 and 145.
The coating rolls 144 and 145 have a transparent liquid attached (impregnated) on the surface, and are disposed at positions where the recording medium P conveyed by the conveying unit 110 is sandwiched. The application rolls 144 and 145 rotate in response to (synchronously with) the movement of the recording medium P while sandwiching the recording medium P, thereby passing the image recording unit 102 and forming an image. The image detection unit 140 and the print defect marking unit 142 apply a transparent liquid to the surface (the surface on which the image is formed) of the recording medium P on which the drawing state inspection has been performed.

  Here, the transparent liquid applied by the varnish coater 143 is an active energy curable transparent liquid 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 composition. , Radical polymerization compositions, aqueous compositions and the like. Details will be described later.

  The ultraviolet irradiation unit 148 is disposed on the downstream side of the varnish coater 143 in the conveyance direction of the recording medium P. The ultraviolet irradiation unit 148 irradiates the recording medium P with active energy (in this embodiment, ultraviolet rays), and cures the smoothed transparent liquid applied to the surface of the recording medium P. As the ultraviolet irradiation unit 148, for example, a metal highland lamp, a high-pressure mercury lamp, a UV-LED, or the like can be used.

  The varnish coater 143 and the ultraviolet irradiation unit 148 are not essential devices for smoothing the foil donation range of the recording medium P, but are arranged because a smooth surface can be obtained by applying a transparent liquid. Is preferred.

As described above, in this embodiment, the conveyance buffer is provided between the smoothing unit 104 and the foil pressing unit 106 described below.
By providing such a transport buffer, it is possible to absorb the slack of the recording medium P caused by the difference in transport speed between the smoothing unit 104 and the foil pressing unit 106, and it is possible to manufacture labels efficiently.

The foil pressing unit 106 includes a foil supply roll 150, a foil winding roll 152, rollers 154 and 156, a foil 158, and a hot stamp plate 160, and the smoothing unit 104 in the conveyance direction of the recording medium P. It is arranged on the downstream side.
The foil supply roll 150 and the foil take-up roll 152 are arranged at a predetermined interval. Further, the roller 154 and the roller 156 are separated from each other by a predetermined distance, the surface connecting the roller 154 and the roller 156 is parallel to the surface of the recording medium P, and more than the foil supply roll 150 and the foil take-up roll 152. It is arranged at a position close to the recording medium P. The rollers 154 and 156 are arranged at positions very close to the recording medium P.
The foil 158 is supplied from the foil supply roll 150, wound around the roller 154 and the roller 156, and then stretched around the foil winding roll 152. Here, the foil 158 between the roller 154 and the roller 156 is parallel to the recording medium P.

The hot stamp plate (letter plate) 160 is disposed between the roller 154 and the roller 156 at a position facing the recording medium P via the foil 158. The hot stamp plate 160 is provided with a relief plate portion 160a that comes into contact with the foil 158 and presses the foil 158 on the surface of the recording medium P, and is formed of zinc, brass, or the like. Further, the hot stamp plate 160 has a heating device (not shown) for heating the relief plate portion 160a and a moving mechanism for moving the hot stamp plate 160 in a direction approaching or separating from the recording medium P.
The hot stamp plate 160 heats the foil 158 onto the recording medium P according to the shape of the relief plate 160a by bringing the heated relief plate 160a into contact with the recording medium P via the foil 158 and pressing it. Crimp.

  The post-processing unit 108 is disposed on the downstream side of the image recording unit 102, the smoothing unit 104, and the foil pressing unit 106 in the conveyance direction of the recording medium P. The post-processing unit 108 is an active energy curable transparent liquid (in this embodiment, an ultraviolet ray). A varnish coater 162 and an ultraviolet irradiation unit 164 for improving gloss by applying a curable transparent liquid) to the image surface, a die cutter 166 for making a label-shaped cut in the recording medium P, and scrap removal as unnecessary part peeling means Part 172.

The varnish coater 162 supplies a transparent active energy (ultraviolet ray in this embodiment) curable liquid (hereinafter also referred to as “active energy curable transparent liquid” or simply “transparent liquid”) to the surface of the recording medium P. It is a supply means, and is arranged on the downstream side of the hot stamp plate 160 of the foil pressing unit 106 in the transport direction of the recording medium P.
The varnish coater 162 has a pair of application rolls with UV-curing transparent liquid adhered (impregnated) on the surface thereof, and supports the movement of the recording medium P (synchronously) while sandwiching the recording medium P. By rotating, the ultraviolet curable transparent liquid is applied to the surface (the surface on which the image is formed) of the recording medium P pressed with foil.

  Here, the transparent liquid applied by the varnish coater 162 is an active energy curable transparent liquid that can be cured by ultraviolet irradiation, and includes at least a polymerizable compound and a photopolymerization initiator as main components, for example, a cationic polymerization composition. Products, radical polymerization compositions, aqueous compositions, and the like. Details will be described later.

The ultraviolet irradiation unit 164 is disposed on the downstream side of the varnish coater 162 in the conveyance direction of the recording medium P. The ultraviolet irradiation unit 164 irradiates the surface of the recording medium P with active energy (in this embodiment, ultraviolet light) to cure the ultraviolet curable transparent liquid applied to the surface of the recording medium P.
By applying and curing an ultraviolet curable transparent liquid on the surface of the recording medium P, the image surface of the recording medium P can be given gloss, and the image quality can be improved.

As shown in FIG. 3, the die cutter 166 is provided with a desired label-shaped cut 180 b only in the adhesive sheet 180 of the printed continuous paper-like recording medium P for label printing. A cylinder cutter 168 disposed on the downstream side of the ultraviolet irradiation unit 164 in the transport direction and disposed on the image forming surface side of the recording medium P, and disposed on the opposite side of the cylinder cutter 168 across the recording medium P. And a receiving roller 170.
The cylinder cutter 168 includes a cylindrical cylinder 168a and a plurality of cutting blades 168b wound around the cylindrical surface of the cylinder 168a and formed in accordance with the shape and arrangement state of the label.

  The die cutter 166 oscillates and rotates intermittently in synchronization with the conveyance speed of the recording medium P while the recording medium P is sandwiched between the cylinder cutter 168 and the receiving roller 170, so that the cutting blade 168b is rotated. A label-shaped cut is made only in the P adhesive sheet 180 (see FIG. 3).

  Here, as shown in FIG. 4, when the circumferential length CL of the cylindrical surface of the cylinder 168a is not an integral multiple of the length LL of the label L, in other words, the circumferential direction of the cylindrical surface of the cylinder 168a. When the length CL and the length CL1 of the cutting blade 168b do not match, a blank portion B where the cutting blade 168b is not provided is generated on the cylindrical surface of the cylinder 168a.

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

  In contrast, in the present embodiment, the die cutter 166 is intermittently swung and rotated in order to eliminate the formation of a useless unnecessary portion P1 of the recording medium P. Thereby, as shown in FIG. 5, the next cut 180b can be made in succession to the rear end of the label group LB having the previous cut 180b. Accordingly, even when the circumferential length CL of the cylindrical surface of the cylinder 168a is not an integral multiple of the length LL of the label L, the unnecessary portion P1 between the label L groups LB and LA is eliminated, and the continuous paper The label-printed recording medium P can be used efficiently.

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

Next, the control unit 112 that controls the conveyance unit 110, the image recording unit 102, the smoothing unit 104, the foil pressing unit 106, the post-processing unit 108, the image detection unit 140, and the print defect marking unit 142 will be described.
As shown in FIG. 2, the control unit 112 is based on a memory 191 that stores recording image data for ink ejection by the recording heads 136Y, 136C, 136M, and 136K of the recording head unit 135, and the recording image data. A head drive control unit 192 that drives and controls the recording heads 136Y, 136C, 136M, and 136K of the recording head unit 135; an image data analysis unit 193 that analyzes the shape of the label L based on the image data stored in the memory 191; A transport speed changing unit 194 that changes the transport speed of the recording medium P for continuous label printing based on the shape of the label L analyzed by the image data analysis unit 193, and a transport speed changed by the transport speed changing unit 194. The transport motor controller 195 controls the rotational speed of the transport motors 126a and 134a based on The die cutter controller 196 that controls the rotational speed of the die cutter 166 based on the transport speed changed by the transport speed changing unit 194, and the image detection that compares the print image on the label surface read by the image detector 140 with predetermined image data. A control unit 197 and a marking control unit 198 for marking the defective printing label when the defective printing label is detected by the image detection control unit 197 are provided.

An input unit 199 such as a computer is connected to the memory 191 of the control unit 112. The memory 191 stores recording image data input from the input unit 199.
Further, the head drive control unit 192 selects an ejection port for ejecting ink droplets of the recording heads 136Y, 136C, 136M, and 136K of the recording head unit 135 based on the image data stored in the memory 191, and ejects ink. The amount of droplets, ejection timing, and the like are calculated, and the recording head unit 135 is controlled based on the calculation result. As an example, in the case of a piezo-type inkjet head as in the present embodiment, a piezoelectric element to which a voltage is applied and a voltage value to be applied among a plurality of ejection portions (ejection ports) according to image data. The application time, application timing, and the like are calculated, and an ejection signal is sent to the recording heads 136Y, 136C, 136M, and 136K based on the calculation results.

The image data analysis unit 193 analyzes the shape of the label L from the label edge data of the image data stored in the memory 191, and sends the analysis result to the conveyance speed change unit 194.
The conveyance speed changing unit 194 stores in advance a conveyance speed that is optimal for post-processing for each shape of the label L, and is analyzed by the image data analysis unit 193 and calculated from the label edge data that has been sent. The optimum transport speed of the recording medium P is calculated from the shape and the stored transport speed, and the calculation result is sent to the transport motor control unit 195 and the die cutter control unit 196.
The transport motor control unit 195 controls the rotation speeds of the transport motors 126a and 134a based on the optimal transport speed calculated by the transport speed changing unit 194. Thereby, the continuous paper-like recording medium P for label printing is transported at an optimum speed.

The die cutter control unit 196 controls the rotational speed of the die cutter 166 based on the optimum transport speed calculated by the transport speed changing unit 194. Specifically, the rotational speed of the die cutter 166 is controlled such that the conveyance speed of the recording medium P and the peripheral speed of the cutting blade 168b of the die cutter 166 are the same.
In this way, the control unit 112 changes or adjusts the conveyance speed of the recording medium P conveyed through the post-processing unit 108 based on the label shape data calculated from the label edge data.

  Further, the transport speed changing unit 194 is based on the shape data of the label L, and is sensitive to unnecessary part peeling (when the peeling is attempted, the part to be peeled is easily broken) The transport speed of the recording medium P at the label part position. It is preferable to control so as to slow down. As a result, it is possible to prevent tearing and breakage during scrap removal, and to reliably remove unnecessary portions other than the label portion.

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

Next, a method for creating a label by the digital label printing apparatus 100 will be described.
As shown in FIG. 1, the recording medium P sent out from the supply roll 122 wound in a roll shape is conveyed by the conveying unit 110 to the undercoat liquid film forming unit 114 and the image recording unit 102.

The undercoat liquid film forming unit 114 forms an undercoat liquid film that is hardened only on the surface of the recording medium P, and the recording heads 136Y, 136C, 136M, and 136K are positioned at opposite positions based on control by the control unit 112. Ink droplets of ultraviolet curable ink are ejected onto the recording medium P that passes. The recording medium P on which the ink has been ejected is further conveyed, passes through a position facing the ultraviolet irradiation units 138 and 139, is irradiated with ultraviolet rays, and the ink is cured.
That is, when the recording medium P passes through the positions facing the recording heads 136Y, 136C, 136M, and 136K, ink droplets are ejected from the recording heads 136Y, 136C, 136M, and 136K toward the recording medium P, and then The ultraviolet rays are irradiated from the ultraviolet irradiation units 138 and 139, and the ink is cured through the process as described above. As a result, an image is formed on the surface of the recording medium P.

Next, the image formed on the surface of the recording medium P is read by the image detection unit 140, and the data is stored in the image data analysis unit 193 under the control of the image detection control unit 197. It is compared with the image data of the print image, and as described above, it is detected whether or not it is a defective print image, that is, whether or not it is a defective print label.
When a defective label is detected as a result of comparison with the image data of the predetermined label print image in the image detection unit 140 described above, the marking control unit 198 prints the print via the defective print marking unit 142. The defective label is marked with a predetermined defective print.
The design, size, etc. of the marking can be arbitrarily determined.

The recording medium P on which the print result has been inspected and on which the image has been formed is transported to the post-processing unit 108 via the transport buffer, and an ultraviolet curable transparent liquid is applied to the surface of the recording medium P by the varnish coater 162. Is applied and then cured by the ultraviolet irradiation unit 164.
The recording medium P coated with the ultraviolet curable transparent liquid is conveyed to the die cutter 166, and the cut 180b is formed in the shape of the label L only on the adhesive sheet 180 by the cylinder cutter 168 and the receiving roller 170.
At this time, as described above, since the die cutter 166 makes the cut 180b having the shape of the label L while swinging intermittently, the cut 180b can be continuously formed, and the recording medium P is wasted. The part never occurs.

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

  Note that, in some cases, an image is recorded by the image recording unit 102, and the label remaining on the recording medium P on which the recorded image is checked is read by the image detection unit 140 in some cases, As a result of comparison with image data of a predetermined label print image, there may be a case where marking indicating a defective print product is given. In this case, for example, an inspection person standing by in the vicinity of the product take-up unit 134 peels off the label on which a marking indicating a defective print is applied, and the normal print is performed instead of the label. Take measures such as attaching a label.

  Such work is based on the premise of conventional visual inspection, which greatly reduces the burden on inspection personnel, etc., thus preventing inspection mistakes such as missing defective products and inspection personnel. This is a great practical effect, such as reducing the degree of fatigue.

  Further, according to the digital label printing apparatus 100 of the present embodiment, the conveyance speed changing unit 194 reduces the conveyance speed of the recording medium P at a label portion position that is weak against unnecessary portion separation based on the label shape data. By doing so, the label L can be prevented from being broken or damaged during post-processing (at the time of scrap removal), and unnecessary portions other than the label portion can be reliably removed. As a result, it is possible to improve productivity by eliminating an apparatus stop caused by tearing or breakage of the label L, and to provide the label L at low cost.

Next, another example of the digital label printing apparatus will be described with reference to FIGS.
Here, FIG. 6 is a front view showing a schematic configuration of another example of the digital label printing apparatus of the present invention using an ink jet recording apparatus as the image forming apparatus of the present invention, and FIG. 7 is a digital view shown in FIG. It is a block diagram which shows the control part which controls a label printing apparatus.
The digital label printing apparatus 200 shown in FIG. 6 has the same configuration as the digital label printing apparatus 100 shown in FIG. 1 except for the post-processing unit 208. Therefore, the same reference numerals are given to the same constituent elements in both, and the detailed description thereof will be omitted, and the following will focus on the points peculiar to the digital label printing apparatus 200.

  As illustrated in FIG. 6, the post-processing unit 208 of the digital label printing apparatus 200 includes a varnish coater 162, an ultraviolet irradiation unit 164, a laser cutter 220, and a residue removing unit 172. The varnish coater 162, the ultraviolet irradiation unit 164, and the residue removing unit 172 are the same as the varnish coater 162, the ultraviolet irradiation unit 164, and the residue removing unit 172 of the post-processing unit 108 shown in the digital label printing apparatus 100 of FIG. Description is omitted.

As in the case of the die cutter 166 of the digital label printing apparatus 100 of FIG. 1, the laser cutter 220 makes a desired label-shaped cut 180b only on the printed adhesive sheet 180 of the recording medium P for continuous label printing. This is disposed between the ultraviolet irradiation unit 164 and the residue removing unit 172.
The laser cutter 220 irradiates the continuous paper-like recording medium P for label printing to be conveyed with laser, and puts a label-shaped cut 180 b only on the adhesive sheet 180.

  As shown in FIG. 7, the control unit 212 includes a memory 191 that stores recording image data for ink ejection by the recording heads 136Y, 136C, 136M, and 136K of the recording head unit 135, and the recording image data to the recording head. A head drive control unit 192 for sending to the recording heads 136Y, 136C, 136M, 136K of the unit 135, an image data analysis unit 193a for analyzing the image density and shape of the label L, and a label L analyzed by the image data analysis unit 193a The conveyance speed changing unit 194 that changes the conveyance speed of the recording medium P based on the shape of the recording medium P, and the conveyance motor control unit that controls the rotation speeds of the conveyance motors 126a and 134a based on the conveyance speed changed by the conveyance speed changing unit 194 195 and the printed image of the label surface read by the image detection unit 140 Includes an image detection control unit 197 to be compared with the image data, when a defect of the label printing is detected by the image detection controller 197, and a marking controller 198 which markings on the print failure of labels. That is, the control unit 212 of the present embodiment has the same configuration as the control unit 112 shown in FIG. 2 except that the functions of the image data analysis unit 193a are partially different and the die cutter control unit 196 is not provided. is there.

The conveyance speed changing unit 194 of the control unit 212 of this embodiment calculates the conveyance speed of the recording medium P according to the density of the image density data at the label edge cut by the laser cutter 220.
In other words, the conveyance speed changing unit 194 stores in advance the optimal post-processing conveyance speed corresponding to the image density, and the image density of the label edge portion analyzed and sent by the image data analysis unit 193a is stored. The optimum transport speed is calculated from the transport speed that has been set, and the calculation result is sent to the transport motor control unit 195.
Specifically, control is performed so that the conveyance speed of the recording medium P is decreased at a position where the image density at the label edge is high. As a result, the image density is high, that is, the portion where the thickness of the label L is thick and difficult to cut out by the laser is irradiated with a lot of energy by slowing the conveyance speed, and the adhesive sheet 180 has a label-shaped cut 180b. Put in.

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

  The transport motor control unit 195 controls the rotation speeds of the transport motors 126a and 134a based on the transport speed changed by the transport speed changing unit 194. Thereby, the continuous paper-like recording medium P for label printing is transported at an optimum speed.

Next, a method for creating a label by the digital label printing apparatus 200 will be described.
The image recording unit 102 forms an image on the surface of the recording medium P on the recording medium P fed from the supply roll 122 in the same manner as the digital label printing apparatus 100 described above.

The recording medium P on which the image is formed is conveyed to the post-processing unit 208 via the conveyance buffer, and the ultraviolet curable transparent liquid is applied to the surface of the recording medium P by the varnish coater 162, and then the ultraviolet irradiation unit. 164 is cured.
The recording medium P coated with the ultraviolet curable transparent liquid is conveyed to the laser cutter 220 and irradiated with a laser, and a cut 180b is formed in the shape of the label L only on the adhesive sheet 180.

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

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

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

  Note that the detection of a defective print label and the marking process performed on the label in this embodiment are performed in the same manner as in the above-described embodiment, and thus description thereof is omitted here.

Next, another example of the digital label printing apparatus will be described with reference to FIG.
Here, FIG. 8 is a front view showing a schematic configuration of another example of the digital label printing apparatus of the present invention using an ink jet recording apparatus as the image forming apparatus of the present invention.
In the digital label printing apparatus 300 shown in FIG. 8, the image recording unit 102 and the smoothing unit 104, and the foil pressing unit 106 and the post-processing unit 108 are integrated into independent and independent devices. The configuration of each part is basically the same as that of the digital label printing apparatus 200 shown in FIG. Therefore, the same reference numerals are given to the same constituent elements in both, and detailed description thereof will be omitted. Hereinafter, points unique to the digital label printing apparatus 300 will be mainly described.

  As shown in FIG. 8, the digital label printing apparatus 300 includes a front processing device 301 having an image recording unit 102 and a smoothing unit 104, and a rear processing device 302 having a foil pressing unit 106 and a post processing unit 108. Prepare.

Next, a characteristic part of the digital label printing apparatus 300 will be described together with a method for creating a label by the digital label printing apparatus 300.
The recording medium P is set on the first supply roll 320 of the front processing apparatus 301 and conveyed to the undercoat liquid film forming unit 114 and the image recording unit 102 by the conveying roller pair 126 and the like. The undercoat liquid film is formed on the surface of the recording medium P by the undercoat liquid film forming unit 114, and the recording medium P conveyed to the image recording unit 102 includes recording heads 136Y, 136C, 136M, 136K and An image is formed on the surface by the ultraviolet irradiation units 138 and 139. The recording medium P on which the image is formed is wound around the collection roll 322. Here, in the present embodiment, the recovery roll 322 is provided with a drive motor 322a, and the recovery roll 322 is used as a drive roller.

  The recording medium P on which the image is formed, that is, the recording medium P taken up by the collection roll 322 is set on the second supply roll 324 of the rear processing device 302. The recording medium P set on the second supply roll 324 is conveyed to the rear processing unit 302 by the conveyance roller pairs 130 and 132.

The recording medium P on which the image is formed is coated with an ultraviolet curable transparent liquid by the varnish coater 162, and then the ultraviolet curable transparent liquid applied by being irradiated with ultraviolet rays from the ultraviolet irradiation unit 164 is cured.
Thereafter, the recording medium P is provided with a cut 180b corresponding to the shape of the label L only on the adhesive sheet 180 by the laser cutter 220, and further, an unnecessary portion of the adhesive sheet of the recording medium P is peeled off by the residue removing portion 172. The paper 182 is peeled off and wound up. On the other hand, the recording medium P in which the unnecessary portion is wound and only the label portion of the adhesive sheet 180 and the release paper 182 are wound is wound around the product winding portion 134 to become a product.

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

In this way, the digital label printing apparatus is a separate apparatus as a front processing apparatus and a rear processing apparatus, so that the label L printing and image surface smoothing preprocessing steps, foil stamping, transparent liquid application (glossy) The post-processing steps such as surface formation), scoring, and scrap removal can be performed as separate operations, and post-processing of various types of labels L can be performed collectively.
In general, the time required for printing is often longer than the time required for post-processing such as scrap removal, and a single rear processing device 302 can handle a plurality of front processing devices 301. , Efficient processing becomes possible.

  Even when the apparatus is separated in this way, the label formed on the adhesive sheet 180 is accurately cut from the surrounding unnecessary portions by controlling the conveyance speed according to the value calculated based on the image data. can do.

Although illustration is omitted, in this embodiment as well, the control unit records image data for recording by the recording heads 136Y, 136C, 136M, and 136K of the recording head unit 135 in the same manner as shown in FIG. A memory 191 that stores image data, a head drive control unit 192 that sends recording image data to the recording heads 136Y, 136C, 136M, and 136K of the recording head unit 135, and an image data analysis unit that analyzes the image density and shape of the label L 193a, a transport speed changing unit 194 that changes the transport speed of the recording medium P based on the shape of the label L analyzed by the image data analysis unit 193a, and a transport based on the transport speed changed by the transport speed changing unit 194 A conveyance motor control unit 195 that controls the rotation speeds of the motors 126a and 134a, and an image detection unit 1 An image detection control unit 197 that compares the printed image of the label surface read by 0 with predetermined image data, and when the defective print label is detected by the image detection control unit 197, marking is performed on the defective print label. And a marking control unit 198 to be applied.
In addition, since the operation of marking the defective print label is performed in the same manner as in the embodiments described above, the description thereof is omitted here.

  As another embodiment, as shown in FIG. 9, a die cutter control unit 196 that controls the rotational speed of the die cutter 166 based on the transport speed changed by the transport speed changing unit 194 in the control unit 112 shown in FIG. Instead of this, there may be mentioned an aspect including a laser cutter control unit 196a that controls the laser output of the laser cutter 220 based on the image of the label L analyzed by the image data analysis unit 193a.

  This embodiment is slightly different from the embodiments described above in its operation. In the control unit 312 of the present embodiment, when the image detection control unit 197 compares the print image on the label surface read by the image detection unit 140 with predetermined image data to detect a defective print label, the marking control unit 198 is used to mark this defective printing label, and this marking is detected by the image detecting unit 140a additionally arranged in the front stage of the laser cutter 220, and the corresponding defective printing label is detected. Therefore, the laser cutter controller 196a performs control so that the laser cutter 220 does not act.

  As a result, in this embodiment, when the unnecessary portion of the pressure-sensitive adhesive sheet of the recording medium P is peeled off from the release paper 182 and wound up by the residue removing portion 172, there is no cut for the defective print label. For this reason, the portion (position) where the unprinted label is peeled off and the defective print label is present becomes a blank area. Therefore, inspectors or the like waiting here do not need to peel off a defective printing label, and only perform an operation of pasting a normal printed label instead of a blank area. It will be.

  In the above-described embodiment, the digital label printing apparatus has been described as an ultraviolet curable inkjet head label printing machine. However, the present invention is not limited to this, and can be applied to any type of printing apparatus, and the same effect can be obtained. Play.

Here, the recording medium is not particularly limited, and papers such as ordinary uncoated paper and coated paper, various non-absorbing resin materials used for so-called soft packaging, or resin films obtained by forming the resin film into a film shape. Examples of various plastic films that can be used 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 a recording medium material include polycarbonate, acrylic resin, ABS, polyacetal, PVA, and rubbers. Metals and glasses can also be used as a recording medium. A surface-treated support serving as a printing plate substrate is used as the recording medium, and an image is formed on the surface of the support with ink-repellent ink. It can also be formed to form a printing plate.
When a material with low thermal shrinkage at the time of curing is selected as the ink, since the adhesive property between the cured ink composition and the recording medium is excellent, curling of the film due to the curing shrinkage of the ink, heat generation during the curing reaction, etc. Films that are easily deformed, 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.

Further, in the above-described embodiment, an ultraviolet curable ink and an ultraviolet curable transparent liquid are used as the undercoat liquid, the ink and the transparent liquid, and an ultraviolet light source is used as a light source for curing the undercoat liquid, the ink and the liquid. The present invention is not limited to this, and various active energy curable undercoat liquids, inks and transparent liquids can be used as the undercoat liquid, ink and transparent liquid, and for curing the undercoat liquid, ink and transparent liquid. As the light source, a light source that emits active energy can be used.
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 undercoat liquid, ink, and transparent liquid by the irradiation. , Α rays, γ rays, X rays, ultraviolet rays, visible rays, electron rays, 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 active energy curable undercoat liquid, the active energy curable ink, and the active energy curable transparent liquid are preferably an undercoat liquid, an ink, and a transparent liquid that can be cured by irradiation with ultraviolet rays.

  Hereinafter, in the ink jet recording apparatus to which the present invention is applied, an active energy curable undercoat liquid, an ink and a transparent liquid that can be suitably used for an ink jet recording apparatus using an active energy curable ink as in the above-described embodiment, The active energy for curing the undercoat liquid and ink will be described in detail. The active energy type transparent liquid is the same as the active energy curable ink except that it does not have a coloring material. Therefore, the active energy type ink will be mainly described below.

The peak wavelength of the active energy depends on the absorption characteristics of the sensitizing dye in the ink (hereinafter also referred to as “ink composition”), but is, for example, 200 to 650 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 start system of the ink of the present invention has sufficient sensitivity even with low output active energy. Thus, the output of the active energy, 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, 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 used in the present invention, active energy irradiation is performed using ultraviolet rays having an emission wavelength peak of 390 to 420 nm and a maximum illuminance on the recording medium surface of 10 to 1,000 mW / cm ^2. Irradiation is preferably from a generated light emitting diode.

In the ink jet recording apparatus to which the present invention is applied, the active energy is applied to the ink composition ejected on the recording medium, for example, for 0.01 to 120 seconds, preferably for 0.1 to 90 seconds. Is appropriate.
Furthermore, in the ink jet recording apparatus to which the present invention is applied, the ink is heated to a certain temperature, and the time from the ink landing on the recording medium to the irradiation of the active energy is 0.01 to 0.5 seconds. Desirably, it is preferably 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 to the recording medium to the irradiation of the active energy to an extremely short time, it is possible to prevent the landed ink from spreading before curing.

  In order to obtain a color image using the ink jet recording apparatus using 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.

  As described above, since it is desirable for the active energy curable ink to have a constant temperature, the temperature of the ink supply tank to the recording head (inkjet head) is controlled by heat insulation and heating. It is preferable to carry out. The recording head unit to be heated is preferably thermally shielded or insulated so that the apparatus main body is not affected by the temperature of 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 UV irradiation parts for curing UV photocurable ink. Yes. 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 can be suitably used as an active energy curable inkjet radiation source (active light source).

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

Below, each component used for the active energy curable ink which can be used suitably by this invention is demonstrated one by one.
Examples of the ink that can be suitably used in the present invention and can be cured by irradiation with active energy 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 anti-fading 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 active energy curable ink is a compound that causes a polymerization reaction by an acid generated from a compound that generates an acid upon irradiation with active energy (b), which will be described later, and is cured. There is no restriction | limiting, The various well-known cationically polymerizable monomer known as a photocationic polymerizable monomer can be used. Examples of the cationic polymerizable monomer include various publications such as JP-A-6-9714, JP-A-2001-31892, JP-A-2001-40068, JP-A-2001-55507, JP-A-2001-310938, JP-A-2001-310937, and JP-A-2001-220526. Examples thereof include epoxy compounds, vinyl ether compounds, oxetane compounds and the like.

Examples of the epoxy compound include aromatic epoxides, alicyclic epoxides, and aliphatic epoxides.
Aromatic epoxides include di- or polyglycidyl ethers produced by the reaction of polyphenols having at least one aromatic nucleus or their alkylene oxide adducts and epichlorohydrin, such as bisphenol A or its alkylene oxides. Examples thereof include di- or polyglycidyl ethers of adducts, di- or polyglycidyl ethers of hydrogenated bisphenol A or 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 an aliphatic polyhydric alcohol or a di- or polyglycidyl ether of an alkylene oxide adduct thereof. Typical examples are 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 suitably used for the active energy curable ink 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- Examples include acryloyloxymethylcyclohexene oxide and 3-vinylcyclohexene oxide.

  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- B pills vinyl ether, isopropyl vinyl ether, isopropenyl ether -O- propylene carbonate, dodecyl vinyl ether, diethylene glycol monovinyl ether, and octadecyl vinyl ether.

The vinyl ether compound may be monofunctional or polyfunctional.
Specifically, examples of monofunctional vinyl ethers include, for example, methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, n-butyl vinyl ether, t-butyl vinyl ether, 2-ethylhexyl vinyl ether, n-nonyl vinyl ether, lauryl vinyl ether, cyclohexyl vinyl ether, Cyclohexylmethyl vinyl ether, 4-methylcyclohexyl methyl vinyl ether, benzyl vinyl ether, dicyclopentenyl vinyl ether, 2-dicyclopentenoxyethyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, butoxyethyl vinyl ether, methoxyethoxyethyl vinyl ether, ethoxyethoxyethyl vinyl ether , Methoxypolyethyleneglycol Vinyl ether, tetrahydrofurfuryl vinyl ether, 2-hydroxyethyl vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 4-hydroxymethylcyclohexyl methyl vinyl ether, diethylene glycol monovinyl ether, polyethylene glycol vinyl ether, chloroethyl vinyl ether, chlorobutyl vinyl ether, Examples include chloroethoxyethyl vinyl ether, phenylethyl vinyl ether, phenoxypolyethylene glycol vinyl ether, and the like.

  Examples of polyfunctional vinyl ethers include ethylene glycol divinyl ether, diethylene glycol divinyl ether, polyethylene glycol divinyl ether, propylene glycol divinyl ether, butylene glycol divinyl ether, hexanediol divinyl ether, bisphenol A alkylene oxide divinyl ether, and bisphenol F. Divinyl ethers such as alkylene oxide divinyl ether; trimethylolethane trivinyl ether, trimethylolpropane trivinyl ether, ditrimethylolpropane tetravinyl ether, glycerin trivinyl ether, pentaerythritol tetravinyl ether, dipentaerythritol pentavinyl ether, dipentaerythritol Hexavinyl ether, ethylene oxide-added trimethylolpropane trivinyl ether, propylene oxide-added trimethylolpropane trivinyl ether, ethylene oxide-added ditrimethylolpropane tetravinyl ether, propylene oxide-added ditrimethylolpropane tetravinyl ether, ethylene oxide-added pentaerythritol tetravinyl ether, propylene oxide addition Examples thereof include polyfunctional vinyl ethers such as pentaerythritol tetravinyl ether, ethylene oxide-added dipentaerythritol hexavinyl ether, and propylene oxide-added dipentaerythritol hexavinyl ether.

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

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

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

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

[(B) Compound that generates acid upon irradiation with active energy]
The active energy curable ink that can be used in the present invention contains a compound that generates an acid upon irradiation with active energy (hereinafter, appropriately referred to as “photo acid 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 to 200 nm ultraviolet rays, far ultraviolet rays, particularly preferably g-line, h-line, i-line, KrF excimer laser beam), ArF excimer laser beam, electron beam, X-ray, molecular beam, ion beam, etc. A compound capable of generating can be appropriately selected and used.

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

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

(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 even more preferably, in terms of the total solid content of the ink composition. Is 1-7 mass%.

[(C) Colorant]
The active energy curable ink 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 pigments preferably used for the active energy curable ink 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 on 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 active energy curable ink include C.I. I. Pigment Yellow 1 (Fast Yellow G etc.), C.I. I. A monoazo pigment such as C.I. Pigment Yellow 74; I. Pigment Yellow 12 (disaji yellow AAA, etc.), C.I. I. Disazo pigments such as C.I. Pigment Yellow 17; I. Non-benzidine type azo pigments such as CI Pigment Yellow 180; I. Azo lake pigments such as C.I. Pigment Yellow 100 (eg Tartrazine Yellow Lake); I. Condensed azo pigments such as CI Pigment Yellow 95 (Condensed Azo Yellow GR, etc.); I. Acidic dye lake pigments such as C.I. Pigment Yellow 115 (such as quinoline yellow lake); I. Basic dye lake pigments such as CI Pigment Yellow 18 (Thioflavin Lake, etc.), anthraquinone pigments such as Flavantron Yellow (Y-24), isoindolinone pigments such as Isoindolinone Yellow 3RLT (Y-110), and quinophthalone yellow Quinophthalone pigments such as (Y-138), isoindoline pigments such as isoindoline yellow (Y-139), C.I. I. Nitroso pigments such as C.I. Pigment Yellow 153 (nickel nitroso yellow, etc.); I. And metal complex salt azomethine pigments such as CI Pigment Yellow 117 (copper azomethine yellow, etc.).

  C. As a thing which exhibits red or magenta color, C.I. I. Monoazo pigments such as CI Pigment Red 3 (Toluidine Red, etc.); I. Disazo pigments such as C.I. Pigment Red 38 (Pyrazolone Red B, etc.); I. Pigment Red 53: 1 (Lake Red C, etc.) and C.I. I. Azo lake pigments such as C.I. Pigment Red 57: 1 (Brilliant Carmine 6B); I. Condensed azo pigments such as C.I. Pigment Red 144 (condensed azo red BR, etc.); I. Acidic dye lake pigments such as C.I. Pigment Red 174 (Phloxine B Lake, etc.); I. Basic dye lake pigments such as C.I. Pigment Red 81 (Rhodamine 6G ′ Lake, etc.); I. Anthraquinone pigments such as C.I. Pigment Red 177 (eg, dianthraquinonyl red); I. Thioindigo pigments such as C.I. Pigment Red 88 (Thioindigo Bordeaux, etc.); I. Perinone pigments such as C.I. Pigment Red 194 (perinone red, etc.); I. Perylene pigments such as C.I. Pigment Red 149 (perylene scarlet, etc.); I. Pigment violet 19 (unsubstituted quinacridone), C.I. I. Quinacridone pigments such as CI Pigment Red 122 (quinacridone magenta, etc.); I. Isoindolinone pigments such as CI Pigment Red 180 (isoindolinone red 2BLT, etc.); I. And alizarin lake pigments such as CI Pigment Red 83 (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 weight copolymer, a modified polyacrylate, an aliphatic Examples thereof include polyvalent carboxylic acids, naphthalene sulfonic acid formalin condensates, polyoxyethylene alkyl phosphate esters, and pigment derivatives. It is also preferable to use a commercially available polymer dispersant such as the Solsperse series from Zeneca.
Moreover, it is also possible to use a synergist according to various pigments as a dispersion aid. These dispersants and dispersion aids are preferably added in an amount of 1 to 50 parts by mass with respect to 100 parts by mass of the pigment.

  In the active energy curable ink, as a dispersion medium for various components such as pigments, a solvent may be added, and the above-mentioned (a) cationic polymerizable compound which is a low molecular weight component without solvent is used as a dispersion medium. However, since the ink is applied to the recording medium and then cured, it is preferably solventless. This is because if the solvent remains in the cured ink image, the solvent resistance is deteriorated or a VOC (Volatile Organic Compound) problem of the remaining solvent occurs. From such a viewpoint, as the dispersion medium, (a) a cation polymerizable compound is used, and among them, it is preferable to select a cation polymerizable monomer having the lowest viscosity in terms of dispersion suitability and handling property of the ink composition. .

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

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

It is also preferable to introduce an oil-solubilizing group into the dye mother nucleus described above in order to dissolve the necessary amount of the dye used in the active energy curable ink in the ink.
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 including 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 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 pigment crystals in the ink is suppressed, and the storage stability of the ink is improved.
In addition, it is desirable that the oxidation potential is noble (high) in order to improve the resistance to the discoloration, in particular, the oxidizing substance such as ozone and the curing characteristics. For this reason, as the oil-soluble dye used in the present invention, those having an oxidation potential of 1.0 V (vs SCE) or more are preferably used. The oxidation potential is preferably higher, the oxidation potential is more preferably 1.1 V (vs SCE) or more, and particularly preferably 1.15 V (vs SCE) or more.

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

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

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

These colorants are preferably added in an amount of 1 to 20% by mass in terms of solid content, and more preferably 2 to 10% by mass.
In addition to the essential components described above, various additives can be used in combination with the active energy curable ink depending on the purpose. These optional components will be described.

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

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

〔Antioxidant〕
An antioxidant can be added to improve the stability of the ink. Examples of the antioxidant include European Published Patent No. 223739, No. 309401, No. 309402, No. 310551, No. 310552, No. 4594416, German Published Patent No. 3435443. JP, 54-85535, 62-267047, 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]
Various organic and metal complex anti-fading agents can be used in the active energy curable ink. Examples of the organic anti-fading agent include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, and heterocycles. Examples of the metal complex anti-fading agent include nickel complexes and zinc complexes. No. 17643, VII, I to J, No. 15162, ibid. No. 18716, page 650, left column, ibid. No. 36544 at page 527, ibid. 307105, page 872, ibid. The compounds described in the patent cited in No. 15162 and the compounds included in the general formulas and compound examples of representative compounds described in JP-A-62-215272, pages 127 to 137 can be used. .
The addition amount is appropriately selected according to the purpose, but is generally about 0.1 to 8% by mass in terms of solid content.

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

〔solvent〕
It is also effective to add an extremely small amount of an organic solvent to the active energy curable ink in order to improve the adhesion to the recording medium.
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 active energy curable ink in order to adjust film physical properties. High molecular compounds include acrylic polymers, polyvinyl butyral resins, polyurethane resins, polyamide resins, polyester resins, epoxy resins, phenol resins, polycarbonate resins, polyvinyl butyral resins, polyvinyl formal resins, shellacs, vinyl resins, acrylic resins. Rubber resins, waxes and other natural resins can be used. Two or more of these may be used in combination. Of these, vinyl copolymer obtained by copolymerization of acrylic monomers is preferred. Furthermore, as a copolymer composition of the polymer binder, a copolymer containing “carboxyl group-containing monomer”, “methacrylic acid alkyl ester”, or “acrylic acid alkyl ester” as a structural unit is also preferably used.

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

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

[Preferred physical properties of ink]
The active energy curable ink 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 injection in consideration of ejection properties. It is preferable to adjust and determine the ratio.

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

  In the printed matter obtained with the active energy curable ink, the image portion is cured by irradiation with active energy such as ultraviolet rays, and the strength of the image portion is excellent. It can be used for various purposes such as formation of a receiving layer (image portion).

[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 active energy curable inks include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc. ) And an aliphatic polyhydric alcohol compound, an amide of the unsaturated carboxylic acid and an aliphatic polyamine compound, and the like.

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

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

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

Other examples include vinyls containing a hydroxyl group represented by the following general formula (A) in a polyisocyanate compound having two or more isocyanate groups per molecule described in JP-B-48-41708. Examples thereof include a vinylurethane compound containing two or more polymerizable vinyl groups in one molecule to which a monomer is added. _{CH 2 = C (R) COOCH} 2 CH (R ') OH (A) ( wherein, R and R' each represents 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 can be used in a chemical form such as a prepolymer, that is, a dimer, a trimer and an oligomer, or a mixture thereof and a copolymer thereof.

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

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

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

(F) [Colorant]
The same (c) colorant as described in the cationic polymerization ink composition can be used.
In addition to the essential components described above, various additives can be used in combination with the active energy curable ink depending on the purpose. These optional components will be described.
[Sensitizing dye]
In the present invention, a sensitizing dye may be added for the purpose of improving the sensitivity of the photopolymerization initiator. Examples of preferred sensitizing dyes include those belonging to the following compounds and having an absorption wavelength in the 350 nm to 450 nm region.
Polynuclear aromatics (eg, pyrene, perylene, triphenylene), xanthenes (eg, fluorescein, eosin, erythrosine, rhodamine B, rose bengal), cyanines (eg, thiacarbocyanine, oxacarbocyanine), merocyanines ( For example, merocyanine, carbomerocyanine), thiazines (eg, thionine, methylene blue, toluidine blue), acridines (eg, acridine orange, chloroflavin, acriflavine), anthraquinones (eg, anthraquinone), squalium (eg, squalium) ), Coumarins (eg, 7-diethylamino-4-methylcoumarin).

[Co-sensitizer]
Furthermore, a known compound having a function of further improving sensitivity or suppressing polymerization inhibition by oxygen may be added to the active energy curable ink as a co-sensitizer.

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

  Other examples include thiols and sulfides, for example, thiol compounds described in JP-A-53-702, JP-B-55-500806, JP-A-5-142772, and JP-A-56-75643. Examples thereof include disulfide compounds, and specific examples include 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, 2-mercapto-4 (3H) -quinazoline, β-mercaptonaphthalene and the like.

  Other examples include amino acid compounds (eg, N-phenylglycine), organometallic compounds described in Japanese Patent Publication No. 48-42965 (eg, tributyltin acetate), and hydrogen described in Japanese Patent Publication No. 55-34414. Donors, sulfur compounds described in JP-A-6-308727 (eg, trithiane), phosphorus compounds described in JP-A-6-250387 (diethylphosphite, etc.), Si-- described in Japanese Patent Application No. 6-191605 H, Ge-H compound, etc. are mentioned.

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

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

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

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

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

[Polymerizable compound]
As the polymerizable compound contained in the aqueous ink composition, 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. 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 propa Triacrylate), 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 addition amount of the oligomer is preferably 1 to 80% by weight and more preferably 1 to 10% by weight with respect to the total weight of the ink.

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

In the above general formulas TX-1 to TX-3, R2 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 an IC system) of a photopolymerization initiator Irgacure 2959 (trade name: manufactured by Ciba Specialty Chemicals) having the following general formula may be used. Specifically, IC-1 to IC-3 having the following formulas can be used.

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

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

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

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

The undercoat liquid is preferably configured to have at least a composition different from that of the ink. Further, the undercoat liquid preferably contains at least one polymerizable or crosslinkable material and is constituted by using a polymerization initiator, a lipophilic solvent, a colorant and other components as necessary.
The polymerization initiator is preferably capable of initiating a polymerization reaction or a crosslinking reaction with active energy rays. As a result, the undercoat liquid applied to the recording medium can be cured by irradiation with active energy rays.
Moreover, it is preferable that undercoat liquid contains a radically polymerizable composition. The radical polymerizable composition in the present invention is a composition containing at least one radical polymerizable material and at least one radical polymerization initiator. Thereby, the curing reaction of the undercoat liquid can be performed with high sensitivity in a short time.

  As described above, the image forming apparatus and the label printing apparatus according to the present invention have been described in detail. However, the present invention is not limited to the above-described embodiments, and various modifications and improvements are made without departing from the spirit of the present invention. Needless to say, it may be.

(A) is a front view showing a schematic configuration of an example of a digital label printing apparatus of the present invention using an ink jet recording apparatus according to an embodiment of the image forming apparatus of the present invention, and (b) is ( It is the elements on larger scale of the other structural example of the inkjet head of the digital label printing apparatus shown to a). It is a block diagram which shows the control part which controls the digital label printing apparatus shown in FIG. It is a longitudinal cross-sectional view of the recording medium for label printing used for the digital label printing apparatus shown in FIG. It is sectional drawing of the die cutter by which the cutting blade was arrange | positioned on the cylindrical surface, and a perspective view which shows the state of the cut | interruption of the adhesive sheet by which this die cutter was rotated continuously and the cut | interruption was made. It is a perspective view which shows the state of the cut of the adhesive sheet in which the cut was put by the die cutter. It is a front view which shows schematic structure of the other example of the digital label printing apparatus of this invention using the inkjet recording device which concerns on one Embodiment of the image forming apparatus of this invention. It is a block diagram which shows the control part which controls the digital label printing apparatus shown in FIG. It is a front view which shows schematic structure of the other example of the digital label printing apparatus of this invention using the inkjet recording device which concerns on one Embodiment of the image forming apparatus of this invention. It is a block diagram which shows the control part which controls the digital label printing apparatus shown in FIG.

Explanation of symbols

100, 200, 300 Digital label printing apparatus 102 Image recording unit (drawing unit)
DESCRIPTION OF SYMBOLS 104 Smoothing part 106 Foil pressing part 108,208 Post-processing part 110 Conveyance part 112,212,312 Control part 114 Undercoat liquid film formation part 116 Roll coater 118,138,139,148,164 Ultraviolet irradiation part 122 Supply roll 126,128 , 130, 132 Transport roller pair 134 Product winding unit 135 Inkjet head 140, 140a Image detection unit 142 Print defect marking unit 143, 162 Varnish coater 160 Hot stamp plate 166 Die cutter 172 Waste removal unit 180 Adhesive sheet 182 Release paper 220 Laser cutter 301 Front processing device 302 Rear processing device 320 First supply roll 322 Collection roll 324 Second supply roll P Recording medium

Claims (6)

Image forming means for forming a plurality of images on the surface of a continuous paper-like recording medium;
A print defect detection unit for detecting a print defect image in a plurality of images formed by the image forming unit;
An image forming apparatus comprising: a printing defect marking means for marking a detected printing defect image.   The image forming apparatus according to claim 1, wherein the image forming unit is an ink jet head using an ink curable by irradiation with active energy.   The image forming apparatus according to claim 2, wherein the print defect detection unit detects a discharge defect of the inkjet head. The image forming unit forms the plurality of images on the surface of the continuous paper-like recording medium based on drawing image data stored in advance;
The printing defect detection means includes first image data obtained by reading the images in the plurality of images formed on the surface of the continuous paper-like recording medium by the image forming means and the drawing image data. Detecting whether the image recorded on the surface of the continuous paper-like recording medium is normal by comparing with the second image data used to form the image The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. A storage unit that stores in advance drawing image data used by the image forming unit to form the plurality of images on the surface of the continuous paper-like recording medium;
Image detecting means for obtaining first image data by reading images in the plurality of images formed on the surface of the continuous paper-like recording medium by the image forming means;
The print defect detection means compares the first image data of the image read by the image detection means with the second image data used to form the image in the drawing image data. The image forming apparatus according to claim 1, wherein the image forming apparatus detects whether the image recorded on the surface of the continuous paper-like recording medium is a normal image or a poorly printed image. An image forming apparatus according to claim 1;
Post-processing means for performing post-processing on the surface of the continuous recording medium on which the plurality of images are formed by the image forming means of the image forming apparatus,
The label printing apparatus, wherein the plurality of images formed by the image forming unit are a plurality of label images, and the images are label images.

Images