JP2008036865A - Inkjet device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent breaking of an inkjet head which may occur when ink is attached to the head by a constitution wherein an adhesive tape having a thickness used in replacement of a recording medium hardly contacts the head. <P>SOLUTION: This inkjet device comprises a recording medium conveyance means for conveying a web type recording medium and a plurality of full-line inkjet head units for ejecting ink according to an image signal toward the recording medium conveyed by the recording medium conveyance means, each of the full-line inkjet head units having a length roughly equal to the width of the recording medium. The inkjet device is equipped with a head unit-retracting means for retracting the full-line inkjet head units from the recording medium. The conveyance of the recording medium is stopped and the retracting means is operated in response to an output of a residual condition detection means for detecting a residual condition of the recording medium. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ink jet apparatus, and more particularly to an active energy curable ink jet apparatus when a recording medium for ejecting active energy curable ink is a web, and the web is replaced with a new web when the web runs out.

Inkjet has the advantage that high-speed and high-quality recording is possible because it is easy to arrange a large number of inkjet heads in a non-contact manner with a recording medium, and has recently been applied to many industrial systems. In particular, a so-called single pass in which an ink jet head having a width capable of recording to the full width of the recording medium is arranged facing the recording medium in a fixed state, and recording is completed only once the recording medium passes under the head. Inkjet devices have been devised. In particular, when an ultraviolet curable ink is used as an ink, several systems have been put on the market in recent years due to advantages such as excellent fast fixability, drawing on various recording media, and environmental friendliness (patents) Reference 1).
JP 2004-314586 A

  When color printing is performed with this single-pass inkjet device, fixed inkjet heads for the number of colors are arranged in the recording medium conveyance direction. In order to increase the productivity of this single-pass system, it is preferable to use a web-shaped recording medium as the recording medium and to connect with a post-processing apparatus such as a cut.

FIG. 5 shows an inkjet apparatus applied to in-line label printing which is the subject of the present invention, in particular, a label printing machine using a web-shaped recording medium as a recording medium and connected to a post-processing apparatus such as cutting. It is also a prior invention related to humans.
In FIG. 5, 100 is a general overview of the inline label printing machine according to the present invention, 100A is an ink jet recording unit, 100B is a die cutting unit, and 104 is interposed between the ink jet recording unit 100A and the die cutting unit 100B. This is a buffer (buffer unit) 104. Reference numeral 101 denotes a recording medium roll in which a label adhesive paper S (hereinafter, recording medium) is wound in a roll shape.

First, the label adhesive paper S used in the present invention will be described.
FIG. 6 is a longitudinal sectional view for explaining the layer structure of the pressure-sensitive adhesive paper for labels.
In FIG. 6, reference numeral 20 denotes a label pressure-sensitive adhesive paper. The label pressure-sensitive adhesive paper 20 is provided on the lowermost base 21 whose surface is peeled off, an adhesive layer 22 provided on the base 21, and the adhesive layer 22 provided thereon. It is made up of paper 23 to be a label.
A label is recorded on the surface of the paper 23 with an ink jet head, and cut to the thickness of the paper 23 and the adhesive layer 22 from above with a die cutter 106c (FIG. 7), which will be described later, equipped with a blade having a shape matching the shape of the label. Thus, the paper 23 and the adhesive layer 22 of the label printing portion are left on the base 21, and the residue from which the label is cut is peeled off from the base 21 and discarded.

Returning to FIG. 5, the inkjet recording unit 100A will be described next.
The recording medium S taken out from the label pressure-sensitive adhesive paper wound in a roll shape is a Y (yellow) full-line inkjet head Y in which a large number of inkjet nozzles are arranged in a staggered arrangement in the width direction of the recording medium S. While transporting underneath, Y color ink is recorded on the recording medium S like a desired label image, and the Y color ink discharged to the recording medium S immediately passes under the active energy curing lamp 103. It is fixed by receiving active energy.

  Next, the M color ink has a desired label on the recording medium S while it is being conveyed under the M (magenta) full line inkjet head M in which a large number of inkjet nozzles are arranged in a staggered arrangement in the width direction of the recording medium S. Immediately thereafter, the M color ink recorded in an image-like manner and discharged onto the recording medium S is fixed by receiving active energy while passing under the active energy curing lamp 103.

  Further, a desired label of the C color ink is formed on the recording medium S while being conveyed under the C (cyan) full-line inkjet head C in which a large number of inkjet nozzles are arranged in a staggered arrangement in the width direction of the recording medium S. Immediately thereafter, the C-color ink recorded in an image-like manner and discharged onto the recording medium S is fixed by receiving active energy while passing under the active energy curing lamp 103.

  Finally, the B-color ink is recorded on the recording medium S while being transported under the B (black) full-line inkjet head B in which a large number of inkjet nozzles are arranged in a staggered arrangement in the width direction (perpendicular to the paper surface in the figure) of the recording medium The B-color ink recorded on the image of the desired label on S and discharged onto the recording medium S is immediately fixed by receiving the active energy while passing under the active energy curing lamp 103. Labels with colored ink are recorded.

  The recorded label passes through a buffer 104 composed of several upper rollers 104a and several lower rollers 104b while moving up and down several times. The buffer 104 is an adjustment unit that absorbs the difference in speed because the upstream ink jet recording unit 100A and the downstream die cutting unit 100B have different working speeds (conveying speed of the recording medium S).

A varnish coater 105 is downstream of the buffer 104. The varnish coater 105 applies a thin varnish to the label surface to improve the scratch resistance of the label surface.
The label cutting unit 106 downstream of the varnish coater 105 includes a marking reader 106a, a die cutter driver 106b, a die cutter 106c formed by mounting a wound product with a blade, and a counter roller 106d.

  The label cut by the die cutter 106c of the label cutting unit 106 is wound downstream of the branch roller 107 as a product label by the label take-up unit 109, and the remaining debris is peeled off and discarded by the waste removing unit 108. To do.

FIG. 7 is a longitudinal sectional view (a) for explaining the structure of a die cutter for cutting a label recorded by a full line inkjet head, and a plan view (b) for explaining a recorded label to be cut.
In FIG. 7A, the die cutter 106c is configured by winding a roll 110 having blades 110a to 110d (four rows in the figure) attached to a base around the surface of the cylinder. In this way, the reason why the die cutter 106c winds the blades 110a to 110d around the surface thereof is that the length in the transport direction varies depending on the size of the seal, so that it corresponds to the size of the seal as a cylinder for die cutting to be used. This is because it is uneconomical to have various diameters. Therefore, instead of preparing only one cylinder here, instead of preparing various types of scrolls with different blade spacings, winding the scroll corresponding to the seal at that time around the cylinder by a magnet mechanism or the like, It constitutes a die cutter.

However, in this case, an area where the roll 110 is not arranged in the circumferential direction of the cylinder is generated. Therefore, when such a die cutter 106c is rotated 360 degrees like a rotary press, the recording medium S is wasted.
Therefore, here, the recording medium S is intermittently conveyed without such usage. That is, when the recording start position of the recording medium S comes directly under the die cutter 106c, the conveyance is stopped, and the cutting edge 110a of the die cutter 106c is made to coincide with the recording start point of the recording medium S to start rotation and recording. The conveyance of the medium S is started at the same speed as the peripheral speed of the die cutter 106c, and the cover on the surface of the recording medium S is cut. When the area of the last blade has passed, the rotation of the die cutter 106c and the conveyance of the recording medium S are performed. The die cutter 106c is lifted and the die cutter 106c is reversely rotated until the tip of the circumferential area where the blade is located is directly below. When the die cutter 106c comes directly below, the reverse rotation is stopped and the die cutter 106c is moved onto the recording medium S. Then, the rotation of the recording medium S is started again, and the conveyance of the recording medium S is started, and the release paper on the surface of the recording medium S is cut.
Thus, the waste of the recording medium is eliminated by intermittently transporting the recording medium S and rotating the cylinder.
Therefore, this intermittent conveyance timing is used for control by effectively using the markings M1 and M2 on the recording medium.

  In FIG. 7B, hatching indicates a label, which is a label that has just been recorded by a full-line inkjet head located upstream (left side in the figure). Here, L11, L12, and L13 in the first column, L21, L22, and L23 in the second column and L31, L32, and L33 in the third column form one group (one batch process of cutting). ing.

  Then, markings M1 and M2 are recorded in a portion of the recording medium S that is not recorded immediately before the first row L11, L12, and L13. In this way, the markings M1 and M2 are performed on the edge of the recording medium for each batch processing of cutting, so that the frequency of use is low among many heads in each full-line inkjet head unit (Y to B in FIG. 5). Since the end head is regularly used, nozzle clogging of the end head is eliminated.

The starting positions of the markings M1, M2 are applied immediately before the first row L11, L12, L13, that is, the portion indicating the cutting start position in the length direction of the recording medium, and the colors are Y, M, C, B The ink may be ejected from the both end heads of the ink jet head to the same starting position, and marking with four colors may be performed, or the color of the ink may be changed for each marking. The point is that the marking can be read by the marking reader 106a (FIG. 5).
The markings M1 and M2 are optically read by the marking reader 106a and input to the die cutter driver 106b, and the die cutter driver 106b controls the die cutter 106C so that the blade comes to the cutting start position.
The signal read by the marking reader 106a is also sent to a recording medium conveyance control unit (not shown). The recording medium conveyance control unit determines the distance between the reading position of the marking reader 106a and the cutting start position of the die cutter 106c at present. By dividing by this transport speed, the time from reception of the read signal to transport stop is obtained, and transport is stopped at that time, so that the leading edge of the recording medium S can be made coincident with the cutting start position.

  FIG. 8 is a perspective view of the vicinity of the branch roller that branches the recording medium S after cutting. The label L whose surface has been cut by the die cutter 106c branches up and down downstream of the branch roller 107, and the base S2 on which the labels L11, L12, and L13 are placed is used as a label product as a label winding unit 109 (FIG. 5). The cover residue S1 which has been wound up and removed from the label proceeds upward and is discarded at the waste removing portion 108 (FIG. 5). The above is the overall flow of label printing according to the prior invention using an inkjet apparatus.

In such a recording apparatus, the recording medium roll 101 gradually disappears during printing, and eventually needs to be replaced with a new roll 101 ′. This exchange is performed as follows.
(1) When the operator recognizes that the remaining recording medium roll 101 has decreased, the conveyance of the recording medium is stopped, and the recording medium S is cut in the width direction with a cutter on the exchange table 92.
(2) Remove the recording medium roll 101 which has been reduced, and set a new recording medium roll 101 ′.
(3) The leading end of the recording medium is pulled out from the new recording medium roll 101 ′ and extended onto the exchange base 92, and this is placed on the rear end of the recording medium that extends below the ink jet head and above the exchange base 92. Place some of them together and connect the joints with adhesive tape.
(4) The operator starts conveyance of the recording medium and resumes label printing / cutting.

  Thus, at the joint of the used part of the adhesive tape used when replacing the recording medium, it has a three-layer structure of the rear end of the old recording medium, the front end of the new recording medium, and the adhesive tape. On the other hand, since the gap between the recording medium and the inkjet head is small in the ink jet apparatus, the seam contacts the head when the seam passes directly under the head, and the ink adheres to the head and damages the head. Or the head is misaligned.

In particular, when an ultraviolet curable ink was used as the ink, the ink adhered to an unnecessary portion of the inkjet head due to contact with the recording medium at the time of replacement, and the ink was cured by the light from the ultraviolet irradiation portion, causing a problem. .
The present invention has been made in order to solve the above-described problems, and prevents the recording medium at the time of replacement from coming into contact with the ink jet head and causing ink to adhere to the unnecessary portion. In contrast, an object is to provide an inexpensive apparatus capable of recording with high image quality.

  In order to solve the above-described problems, an invention of an ink jet apparatus according to claim 1 is directed to a recording medium conveying unit that conveys a web-shaped recording medium, and an image signal toward the recording medium conveyed by the recording medium conveying unit. In the ink jet apparatus having a plurality of full line ink jet head units having substantially the same length as the width of the recording medium ejected based on the head unit retracting means for retracting the full line ink jet head unit from the recording medium or the full line A platen retracting means for retracting the recording medium from the ink jet head unit is provided.

  According to a second aspect of the present invention, in the ink jet apparatus according to the first aspect of the present invention, the ink jet apparatus further includes a remaining state detecting unit that detects a remaining state of the recording medium, and stops conveying the recording medium by an output of the remaining state detecting unit. In addition, the retracting means operates.

  According to a third aspect of the present invention, in the ink jet apparatus according to the second aspect, the remaining state detecting means detects a remaining film thickness of the web-shaped recording medium, detects a change in tension of the web-shaped recording medium, and One of the weight detections of the web-shaped recording medium is detected.

  According to a fourth aspect of the invention, there is provided the ink jet apparatus according to the first aspect, further comprising seam detecting means for detecting a seam of the recording medium, and the retracting means is operated by an output of the seam detecting means. Yes.

  According to a fifth aspect of the present invention, in the ink jet apparatus according to the fourth aspect, the seam detection means detects a change in height of the seam of the recording medium.

  According to a sixth aspect of the present invention, in the ink jet apparatus according to any one of the first to fifth aspects, another seam detection means is provided downstream of the full line ink jet head, and the seam detection means When detected, the retracting means performs an operation of returning from the retracted state.

  According to a seventh aspect of the present invention, in the ink jet apparatus according to any one of the first to fifth aspects, the head unit retracting means is restarted after a seam with a new recording medium roll is formed. After the recording medium is sent out for a certain length, the recording medium is finally restored from the retracted state.

  The invention according to claim 8 is the ink jet apparatus according to any one of claims 1 to 7, wherein the ink is curable when irradiated with active energy, and the recording is performed by the full line head. An ultraviolet irradiation means for curing the ink ejected on the medium is included, and the ultraviolet irradiation is shielded, stopped, or dimmed during the retreat operation.

  In the ink jet apparatus, even if the gap between the recording medium and the ink jet head is small, the head when the web is switched according to the present invention is moved away from the recording medium by the retraction mechanism so that the ink jet head exceeds the thickness of the adhesive tape used at the time of replacement. Therefore, the adhesive tape does not come into contact with the ink jet head, and the ink does not damage the head or the head is not misaligned.

  Hereinafter, the present invention will be described based on examples of a label printing machine using an ink jet apparatus.

1 is a label printing machine according to a first embodiment of the present invention.
In FIG. 1, reference numeral 100-1 is an overall overview of the inline label printer according to the first embodiment of the present invention. The members having the same reference numerals as those in FIG.
The inline label printer 100-1 according to the first embodiment of the present invention is different from the inline label printer 100 of FIG.
One is a head unit that moves the ink jet recording unit 100A in the upper direction (the direction in which it is retracted from the recording medium S) indicated by a white arrow in FIG. 1 whereas the ink jet recording unit 100A is fixed in the prior invention. The retracting means 98 is provided. The specific head unit retracting means 98 can be realized by a linear motor, for example. That is, it can be easily realized by attaching the movable portion 98a of the linear motor to the casing of the ink jet recording portion 100A and providing the fixed portion 98b on the recording device (chassis) side. In addition, it may be moved by a pneumatic or hydraulic device.

  The distance at which the head unit is retracted is a sufficient distance that does not contact the ink jet head when the joint with the adhesive tape used at the time of replacement with the new recording medium roll 101 'passes under the ink jet head.

A second point different from the inline label printer 100 of the prior invention is that a remaining state detecting means for detecting the remaining state of the recording medium S of the recording medium roll 101 is provided in the vicinity of the recording medium roll 101. This remaining state detection means is installed in the vicinity of the recording medium roll 101 as a distance sensor using light, sound waves or radio waves as an end sensor 90, and measures the distance to the surface of the recording medium roll (web-shaped recording medium). When the distance becomes a distance until it is determined that the remaining film thickness has almost disappeared, the conveyance of the recording medium is interrupted and the replacement of the roll is notified.
Further, at this time, the head unit retracting means 98 may be operated to retract the ink jet recording unit 100A from the recording medium S.

As a first modification of the first embodiment, instead of the end sensor 90 as the remaining state detecting unit, a tension sensor 91 may be provided as a remaining state detecting unit at the core portion of the recording medium roll 101. That is, the end of the web-shaped recording medium is either (a) fixed to the core of the roll 101 with an adhesive tape or (b) wound around free.
Therefore, when the recording medium is normally pulled out, since the predetermined tension is applied to the core of the roll 101, the tension sensor 91 detects the predetermined tension.
On the other hand, when the end of the recording medium is separated from the core of the roll 101, a large tension is applied to the core of the roll 101 in the case of fixing the adhesive tape in (a), so the tension sensor 91 detects a large tension. In the case of (b) free winding, since the tension is zero, the tension sensor 91 detects zero tension, and in any case, the tension sensor 91 detects a value that deviates from a predetermined tension. Thus, it can be seen that the recording medium roll 101 is gone.
At this time, the conveyance of the recording medium is interrupted, and the replacement of the roll is notified. Further, the ink jet recording unit 100A may be retracted from the recording medium S by operating the head unit retracting means 98.

  In addition, when there is a margin in the remaining roll, for example, when the conveyance is manually stopped, there is no fluctuation in tension, but the tension sensor of the feeding-side roll changes in tension when the recording medium is cut on the exchange table. Since this is detected, this tension change can also be used.

  Next, as a second modification of the first embodiment, instead of the tension sensor 91, a weight sensor that detects the weight of the web-shaped recording medium can be used as the remaining state detection unit. When this weight sensor detects the weight when the recording medium roll 101 is exhausted by the remaining state detecting means, the conveyance of the recording medium may be interrupted and the replacement of the roll may be notified.

The operation flow in the case of the first embodiment is as follows.
Step 1: When the end sensor, tension sensor, or weight sensor detects that the remaining recording medium roll is low, the feeding of the recording medium is stopped and the replacement of the roll is notified, and the head unit retracting means according to the present invention Operates to retract the head from the recording medium.
Step 2: The operator who is notified of the roll exchange cuts the recording medium of the existing recording medium roll with a cutter on the exchange table.
Step 3: The operator sets a new recording medium roll, pulls out the leading end of the recording medium roll, overlaps the end of the recording medium cut in Step 2 on the exchange base, and connects the overlapping portions with cellophane tape. .
Step 4: When the recording medium tip of the new recording medium roll is connected to the end of the existing recording medium with the adhesive tape, the conveyance of the recording medium is restarted until the joint by the adhesive tape passes under the head. Continue the above evacuation state. Thereby, even if the thickness of the adhesive tape is large, the adhesive tape does not contact the head, and there is no possibility of damage to the head. Also, if the UV lamp shutter is closed or the lamp is turned off or dimmed when the seam passes under the head, the ink will not solidify even if ink adheres to other parts.
Step 5: After the joint by the adhesive tape passes through the lower part of the head, the operator returns the above retracted state and opens the UV lamp shutter or fully turns on the lamp.
Step 6: Normal label printing is resumed.

  As described above, according to the first embodiment, when the web runs out, it is automatically detected and notified, and the inkjet head automatically exceeds the thickness of the adhesive tape by the head retracting mechanism. Therefore, even in an ink jet apparatus in which the gap between the recording medium and the ink jet head is small, the adhesive tape may not contact the ink jet head, and the ink may damage the head or the head may be misaligned. I don't get up.

FIG. 2 is a label printing machine according to a second embodiment of the present invention.
In FIG. 2, reference numeral 100-2 denotes an overall overview of the inline label printer according to the second embodiment of the present invention. The members having the same reference numerals as those in FIG.
The inline label printing machine 100-2 according to the second embodiment of the present invention is different from the prior invention of FIG. 5 and the same points as the inline label printing machine 100-1 of the first embodiment of FIG. The head unit retracting means 98 for moving in the retracting direction from S is provided.

  On the other hand, the inline label printer 100-2 according to the second embodiment of the present invention is different from the inline label printer 100-1 according to the first embodiment shown in FIG. 1 in that the inline label printer 100- according to the first embodiment shown in FIG. In FIG. 1, the start of the operation of the head unit retracting unit 98 is the time when the end sensor 90, the tension sensor 91, or the weight sensor detects that the remaining amount of the recording medium roll 101 has decreased. The seam sensor 93 is provided upstream in the conveyance direction of the ink jet recording unit 100 </ b> A, and the seam sensor 93 detects the seam of the recording medium roll 101. The rest is the same as the inline label printing machine 100-1 of the first embodiment shown in FIG.

  The seam sensor is a distance sensor based on light, sound waves, or radio waves that is installed as a seam sensor 93 between the exchange base 92 and the presser roller 94 to accurately measure the distance to the surface of the recording medium roll (web-shaped recording medium). Thus, the difference between the distance to the surface of the seamless part of the recording medium and the distance to the surface of the part of the recording medium having the joint is discriminated. Then, when it is determined that a part having a seam of the recording medium has arrived, the head unit retracting means 98 is automatically operated to retract the ink jet recording unit 100A from the recording medium S.

Therefore, the operation flow in the second embodiment is as follows.
Step 1: When the remaining recording medium roll is low, the operator stops feeding the recording medium.
Step 2: The operator cuts the recording medium of the existing recording medium roll on the exchange table with a cutter.
Step 3: The operator sets a new recording medium roll, pulls out the leading end of the recording medium roll, overlaps the end of the recording medium cut in Step 2 on the exchange base, and connects the overlapping portions with cellophane tape. .
Step 4: When the recording medium tip of the new recording medium roll is connected to the end of the existing recording medium with the adhesive tape, the conveyance of the recording medium is restarted. When the seam of the adhesive tape passes under the seam sensor 93, the head unit retracting means 98 according to the present invention operates to retract the head from the recording medium. The above retracted state is continued until the lower part of the head is passed. Thereby, even if the thickness of the adhesive tape is large, the adhesive tape does not contact the head, and there is no possibility of damage to the head. Also, if the UV lamp shutter is closed or the lamp is turned off or dimmed when the seam passes under the head, the ink will not solidify even if ink adheres to other parts.
Step 5: After the seam by the adhesive tape passes through the lower part of the head, the operator restores the retracted state and opens the UV lamp shutter or turns on or turns off the lamp.
Step 6: Normal label printing is resumed.

  As described above, according to the second embodiment, even if the gap between the recording medium and the inkjet head is small, the inkjet head automatically moves the adhesive tape on the adhesive tape when the web seam is detected. Since it is retracted from the recording medium more than the thickness, the adhesive tape does not come into contact with the ink jet head, and the ink does not break the head with respect to the head or the head is not misaligned.

FIG. 3 is a label printing machine according to a third embodiment of the present invention.
In FIG. 3, reference numeral 100-3 is an overall overview of the inline label printer according to the third embodiment of the present invention. Components having the same reference numerals as those in FIGS. 1 and 2 are members having the same functions, and thus redundant description is omitted.
The inline label printer 100-3 according to the third embodiment of the present invention is the same as the inline label printers 100-1 and 100-2 in the first embodiment (FIG. 1) and the second embodiment (FIG. 2). The head unit retracting means 98 for moving the portion 100A in the direction of retracting the recording medium S from the recording medium S is provided.

  On the other hand, the inline label printer 100-3 according to the third embodiment of the present invention is different from the first and second embodiments in that the joint sensor 95 is provided downstream of the ink jet recording unit 100A in the third embodiment. When the sensor 95 detects the seam of the recording medium roll, the head unit retracting unit 98 automatically returns the ink jet recording unit 100A to the original position (in the first and second embodiments, the operator manually operates). ) The rest is the same as the inline label printers 100-1 and 100-2 of the first and second embodiments.

  The joint sensor 95 may be the same as the joint sensor 93 used in the second embodiment. That is, a distance sensor using light, sound waves, or radio waves is installed as a joint sensor 95 downstream of the ink jet recording unit 100A, and the distance to the surface of the recording medium roll (web-shaped recording medium) is accurately measured. The difference between the distance to the surface of the seamless part and the distance to the surface of the seam part of the recording medium is discriminated. Then, when it is determined that a part with a seam of the recording medium has arrived, the head unit retracting means 98 is automatically returned to return the ink jet recording unit 100A to the position closest to the recording medium S.

Therefore, the operation flow in the third embodiment is as follows.
Step 1: The operator sets a new recording medium roll, pulls out the leading end of the recording medium roll, overlaps the end of the recording medium cut in Step 2 on the exchange base, and connects the overlapping portions with cellophane tape. .
Step 2: When the recording medium tip of the new recording medium roll is connected to the end of the existing recording medium with the adhesive tape, the conveyance of the recording medium is restarted. When the joint by the adhesive tape passes through the lower part of the head (the head is already in the retracted state according to Example 1 or 2), the adhesive tape does not contact the head.
Step 3: When the joint by the adhesive tape passes under the joint sensor 95, the retracted state is automatically restored according to the third embodiment, and the UV lamp shutter is opened or the lamp is fully turned on.
Step 4: Normal label printing is resumed.

  As described above, according to the third embodiment relating to the automatic return of the head retracting mechanism, the seam sensor 95 is automatically operated after the inkjet head is retracted from the recording medium by the head retracting mechanism and the adhesive tape passes through the inkjet head. Since the retracted state is returned to the original state, there is no possibility of the operator performing an erroneous operation.

  As a first modification of the third embodiment, after a new roll is set and re-conveyance is started, the recording medium is sent out a certain length (the length until the joint passes under the head). If the head unit retracting means returns the full line inkjet head unit from the retracted state, the joint sensor 95 is not necessary.

FIG. 4 shows a label printer according to a fourth embodiment of the present invention.
In FIG. 4, reference numeral 100-4 denotes an overall overview of the inline label printer according to the fourth embodiment of the present invention. The members having the same reference numerals as those in FIGS. 1 to 3 are members having the same functions, and thus redundant description is omitted.
The inline label printing machine 100-4 according to the fourth embodiment of the present invention has one difference from the inline label printing machines 100-1 to 100-3 according to the first to third embodiments.
This is because the head unit retracting means 98 for moving the ink jet recording unit 100A in the direction in which the ink jet recording unit 100A is retracted from the recording medium S is provided in Example 1-3, whereas the ink jet recording unit 100A is not moved in Example 4. The point that the side of the recording medium S is withdrawn. That is, the platen 96 is used at the position indicated by the dotted line during printing, but after the recording medium roll is replaced, the platen 96 is solid when the seam of the adhesive tape passes under the head when the recording medium is transported again. Thus, the adhesive tape does not come into contact with the head even if the thickness of the adhesive tape is thick, thereby eliminating the possibility of damage to the head.

  The specific head unit retracting means 99 can be realized by a linear motor, for example. That is, it can be easily realized by attaching the linear motor rail (fixed portion) 99a to the platen 96 and providing the moving portion 99b on the recording device (chassis) side. In addition, it may be moved by a pneumatic or hydraulic device.

  The distance at which the platen 96 is retracted is a sufficient distance that does not contact the inkjet head when the joint with the adhesive tape used at the time of replacement with the new recording medium roll 101 ′ passes under the inkjet head.

In addition, as a remaining state detecting means for detecting the remaining state of the recording medium S of the recording medium roll 101 in the vicinity of the recording medium roll 101, an end sensor 90, a tension sensor 91, and a weight sensor for detecting the weight of the web-shaped recording medium. This is the same in that when the weight when the recording medium roll 101 is lost is detected, the conveyance of the recording medium is interrupted and the replacement of the roll is notified.
The same is true in that the platen 96 is retracted (lowered) using the joint sensor 93 and the platen 96 is returned to the original state using the joint sensor 95.

Therefore, the operation flow in the case of Example 4 is as follows.
Step 1: When the end sensor, tension sensor, or weight sensor detects that the remaining amount of the recording medium roll has decreased, the feeding of the recording medium is stopped, and the operator is notified of the roll replacement (Example 1). Also adopted here).
Step 2: The operator cuts the recording medium of the existing recording medium roll on the exchange table with a cutter.
Step 3: The operator sets a new recording medium roll, pulls out the leading end of the recording medium roll, overlaps the end of the recording medium cut in Step 2 on the exchange base, and connects the overlapping portions with cellophane tape. .
Step 4: When the recording medium tip of the new recording medium roll is connected to the end of the existing recording medium with the adhesive tape, the conveyance of the recording medium is restarted.
Step 5: When the seam by the adhesive tape passes under the seam sensor 93, the platen retracting means 99 is operated to retract (lower) the platen 96 (that is, the recording medium S) from the head (Example 4). The retracted state is continued until the seam passes under the head. Thereby, even if the thickness of the adhesive tape is large, the adhesive tape does not contact the head, and there is no possibility of damage to the head. Also, if the UV lamp shutter is closed or the lamp is turned off or dimmed when the seam passes under the head, the ink will not solidify even if ink adheres to other parts.
Step 6: When the seam of the adhesive tape passes under the seam sensor 95, the retracted state is automatically restored (the third embodiment is also adopted here), and the UV lamp shutter is opened, or the lamp is turned on or off. Light up.
Step 7: Normal label printing is resumed.

  As described above, according to the fourth embodiment, even when the gap between the recording medium and the inkjet head is small, the platen retracting mechanism automatically operates when the seam after replacing the web passes under the head. Since the platen descends from the vicinity of the head more than the thickness of the adhesive tape, the adhesive tape will not contact the inkjet head, ink may adhere to the inkjet head, damage the head, or the inkjet head may be misaligned. I don't get up.

According to the fourth embodiment, since there is no movement of the inkjet head, there is no fear of drawing position shift or ink leakage due to movement.
In addition, since the recording medium S can be printed in a state of being pulled more than in the first to third embodiments, the gap control can be performed accurately.
Furthermore, many secondary effects such as maintaining the positional relationship with the ink tank and facilitating maintenance can be obtained.

  The UV ink composition is preferably an ink composition that can be cured by irradiation with active energy.

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

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

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

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

  The inkjet head of the present invention is, for example, a piezo-type inkjet head, and multi-size dots of 1 to 100 pl, preferably 1 to 30 pl, for example, 320 × 320 to 4000 × 4000 dpi, preferably 400 × 400 to 2400 × 2400 dpi. It can drive so that it can inject with the resolution of. In the present invention, dpi represents the number of dots per 2.54 cm.

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

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

  Further, as described above, a light emitting diode (LED) and a laser diode (LD) can be used as the active energy source. In particular, when an active energy 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 active energy 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.

〔recoding media〕
The label recording medium used in the present invention is not particularly limited, and covers various kinds of non-absorbent resin materials used for ordinary non-coated paper, coated paper, and so-called soft packaging as a cover, or in the form of a film. A molded resin film can be used, and examples of various plastic films include PET film, OPS film, OPP film, ONy film, PVC film, PE film, and TAC film.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  Examples of such a photoacid generator include an onium salt such as a diazonium salt, an ammonium salt, a phosphonium salt, an iodonium salt, a sulfonium salt, a selenonium salt, an arsonium salt, or the like, which decomposes upon irradiation with radiation to generate an acid. Halogen compounds, organometallic / organic halides, photoacid generators having o-nitrobenzyl type protecting groups, compounds that generate sulfonic acids upon photolysis, such as iminosulfonates, disulfone compounds, diazoketosulfones And diazodisulfone compounds.

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

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

  In the ink composition of the present invention, various additives can be used in combination with the essential components according to the purpose. These optional components will be described.

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

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

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

  C. As a thing which exhibits red or magenta color, C.I. I. Monoazo pigments such as CI Pigment Red 3 (Toluidine Red, etc.); I. Disazo pigments such as C.I. Pigment Red 38 (Pyrazolone Red B, etc.); I. Pigment Red 53: 1 (Lake Red C, etc.) and C.I. I. Azo lake pigments such as C.I. Pigment Red 57: 1 (Brilliant Carmine 6B); I. Condensed azo pigments such as C.I. Pigment Red 144 (condensed azo red BR, etc.); I. Acidic dye lake pigments such as C.I. Pigment Red 174 (Phloxine B Lake, etc.); I. Basic dye lake pigments such as C.I. Pigment Red 81 (Rhodamine 6G ′ Lake, etc.); I. Anthraquinone pigments such as C.I. Pigment Red 177 (eg, dianthraquinonyl red); I. Thioindigo pigments such as C.I. Pigment Red 88 (Thioindigo Bordeaux, etc.); I. Perinone pigments such as C.I. Pigment Red 194 (perinone red, etc.); I. Perylene pigments such as C.I. Pigment Red 149 (perylene scarlet, etc.); I. Pigment violet 19 (unsubstituted quinacridone), C.I. I. Quinacridone pigments such as CI Pigment Red 122 (quinacridone magenta, etc.); I. Isoindolinone pigments such as CI Pigment Red 180 (isoindolinone red 2BLT, etc.); I. And alizarin lake pigments such as CI Pigment Red 83 (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 ink composition, as a dispersion medium for various components such as pigments, a solvent may be added, or the solvent-free low molecular weight component (a) cationic polymerizable compound may be used as a dispersion medium. However, the ink composition of the present invention is a radiation curable ink, and is preferably solventless in order to cure the ink after it is applied to a recording medium. This is because if the solvent remains in the cured ink image, the solvent resistance is deteriorated or a VOC (Volatile Organic Compound) problem of the remaining solvent occurs. From such a viewpoint, as the dispersion medium, (a) a cation polymerizable compound is used, and among them, it is preferable to select a cation polymerizable monomer having the lowest viscosity in terms of dispersion suitability and handling property of the ink composition. .

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

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

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

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

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

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

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

  These colorants are preferably added in an amount of 1 to 20% by mass in terms of solid content in the ink composition, and more preferably 2 to 10% by mass.

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

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

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

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

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

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

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

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

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

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

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

[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.

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

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

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

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

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

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

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

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

  Preferred polymerization initiators include (i) aromatic ketones, (ii) aromatic onium salt compounds, (iii) organic peroxides, (iv) hexaarylbiimidazole compounds, (v) ketoxime ester compounds, (vi ) Borate compounds, (vii) azinium compounds, (viii) metallocene compounds, (ix) active ester compounds, (x) compounds having a carbon halogen bond, and the like.

[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 (for example, thionine, methylene blue, toluidine blue), acridines (for example, acridine orange, chloroflavin, acriflavine), anthraquinones (for example, anthraquinone), squalium (for example, squalium) ), Coumarins (eg 7-diethylamino-4-methylcoumarin).

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

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

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

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

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

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

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

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

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

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

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

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

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

  As prescription conditions when applied to such a clear ink, the water-soluble polymerizable compound as a main component of the ink is 10 to 85%, a photopolymerization initiator (for example, an active energy polymerization catalyst), and the water-soluble compound described above. It is preferable to prepare such that 1 to 10 parts by mass with respect to 100 parts by mass of the polymerizable compound and, at the same time, at least 0.5 part of the photopolymerization initiator is contained with respect to 100 parts of ink.

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

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

[Preferred physical properties of ink composition]
The ink composition of the present invention preferably has an ink viscosity of 7 to 30 mPa · s, more preferably 7 to 20 mPa · s at the temperature at the time of ejection in consideration of ejection properties, and is in the above range. It is preferable to adjust the composition ratio appropriately. The ink viscosity at 25 to 30 ° C. is 35 to 500 mPa · s, preferably 35 to 200 mPa · s. By setting the viscosity at room temperature high, even when a porous recording medium is used, ink penetration into the recording medium can be prevented, uncured monomer can be reduced, and odor can be reduced. Dot bleeding at the time of landing can be suppressed, and as a result, the image quality is improved. If the ink viscosity at 25 to 30 ° C. is less than 35 mPa · s, the effect of preventing bleeding is small, and conversely if it is greater than 500 mPa · s, there is a problem in the delivery of the ink liquid.

It is a conceptual diagram explaining the in-line label printing machine which concerns on Example 1 of this invention. It is a conceptual diagram explaining the inline label printing machine which concerns on Example 2 of this invention. It is a conceptual diagram explaining the inline label printing machine which concerns on Example 3 of this invention. It is a conceptual diagram explaining the inline label printing machine which concerns on Example 4 of this invention. It is a conceptual diagram explaining the in-line label printing machine which concerns on the prior invention of this invention. It is a longitudinal cross-sectional view explaining the layer structure of the adhesive paper for labels which this invention uses. It is the longitudinal cross-sectional view (a) explaining the structure of the die cutter which cuts the label recorded with the full line head, and the top view (b) explaining the recorded label. It is a perspective view of the branch roller vicinity shown in FIG.

Explanation of symbols

20 Adhesive paper for label 21 Base 22 Adhesive layer 2
23 Release paper 90 End sensor 91 Tension sensor 92 Exchange base 93, 95 Joint sensor 94 Pressing roller 96 Platen 98 Head unit retracting means 98a Linear motor movable part 98b Linear motor fixed part 99 Platen retracting means 99a Linear motor movable part 99b Fixed part 100-1 of linear motor Inline label printing machine 100-2 according to Example 1 of the present invention Inline label printing machine 100-3 according to Example 2 of the present invention Inline label printing machine according to Example 3 of the present invention 100-4 Inline Label Printing Machine 101 According to Embodiment 4 of the Present Invention Recording Medium Roll 101 ′ in Use New Recording Medium Roll 100A to be Replaced Inkjet Recording Unit 100B Die Cutting Unit 103 Active Energy Curing Lamp 104 Buffer 104a Low Roller 104b Lower roller 105 Varnish coater 106 Label cutting part 106a Marking reader 106b Die cutter driver 106c Die cutter 106d Opposing roller 110 Bladed roll 110a-d Blade 107 Branch roller 108 Waste part 109 Label winding part L11, L12, L13 First Labels L21, L22, L23 in the second row Labels L31, L32, L33 in the second row Labels M1, M2 in the third row Marking S Recording medium

Claims (8)

Recording medium conveying means for conveying a web-shaped recording medium, and a plurality of full lines having substantially the same length as the width of the recording medium ejected based on the image signal toward the recording medium conveyed by the recording medium conveying means In an inkjet apparatus having an inkjet head unit,
An ink jet apparatus comprising: a head unit retracting means for retracting the full line ink jet head unit from the recording medium; or a platen retracting means for retracting the recording medium from the full line ink jet head unit.   2. The ink jet apparatus according to claim 1, further comprising a remaining state detecting unit configured to detect a remaining state of the recording medium, wherein the conveyance of the recording medium is stopped by the output of the remaining state detecting unit and the retracting unit is operated. apparatus.   The remaining state detecting means detects any of a remaining film thickness of the web-shaped recording medium, a change in tension of the web-shaped recording medium, and a weight detection of the web-shaped recording medium. The inkjet apparatus according to claim 2.   2. The ink jet apparatus according to claim 1, further comprising a seam detecting unit that detects a seam of the recording medium, wherein the retracting unit is operated by an output of the seam detecting unit.   5. The ink jet apparatus according to claim 4, wherein the seam detecting means detects a change in height of the seam of the recording medium.   2. Another seam detection means is provided downstream of the full-line inkjet head, and when the seam detection means detects the seam, the retracting means performs an operation of returning from the retracted state. The inkjet apparatus of any one of -5.   The head unit retreating means finally performs an operation of returning from the retracted state after the recording medium is sent out for a certain length after a joint with a new recording medium roll is formed and transport is restarted. The inkjet device according to claim 1.   The ink is curable by irradiation with active energy, and includes ultraviolet irradiation means for curing the ink ejected onto the recording medium by the full line head, and shields or stops ultraviolet irradiation during the retraction operation. The ink jet device according to claim 1, wherein the ink jet device is dimmed.

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