WO2013145946A1

WO2013145946A1 - Method for manufacturing marked reflective sheet

Info

Publication number: WO2013145946A1
Application number: PCT/JP2013/054006
Authority: WO
Inventors: 中沢　広樹; 育樹太田
Original assignee: 日本カーバイド工業株式会社
Priority date: 2012-03-26
Filing date: 2013-02-19
Publication date: 2013-10-03
Also published as: JP2015121566A

Abstract

Provided is a method for manufacturing a reflective sheet whereby a marked reflective sheet having more favorable luster can be simply produced. The method for manufacturing a marked reflective sheet according to the present invention comprises: a first ejection process of sequentially ejecting a first droplet (ID1) of uncured photocurable ink on the surface of the reflective sheet while moving an ejector (20) from one end to the other in the scanning direction; and a second ejection process of turning on a beam irradiator (30) mounted on the back side of the ejector (20) and sequentially ejecting a second droplet (ID2) of uncured photocurable ink so as to be in touch with the first droplet (ID1) while moving the ejector (20) from the other end to the one end.

Description

Manufacturing method of reflective sheet with marking part

The present invention relates to a technique for manufacturing a character sheet, a figure, a symbol or the like with a marking portion attached to the surface of a reflection sheet.

Conventionally, there is a printing technique as a technique for attaching the marking portion to the surface of the reflection sheet, and an inkjet method is one of the printing techniques. As one of the prior art documents using the ink jet system, there is the following Patent Document 1.

Patent Document 1 discloses a technique of printing UV ink on recording paper using an ink head having an inkjet nozzle and an ultraviolet lamp and reciprocally movable from a predetermined scanning position.

Specifically, when the ink head moves in the direction of travel, UV ink is ejected from the inkjet nozzles with the ultraviolet lamp not illuminated. On the other hand, when the ink head moves in the return direction, the UV lamp is turned on without UV ink being ejected from the inkjet nozzle, and the UV ink ejected when moving in the outbound direction is cured.

According to such a method, the hemispherical UV ink at the time of landing diffuses and spreads until it is cured by the ultraviolet lamp, and is cured in a shape in which the UV inks adjacent to each other are connected to each other. There is a description that glossy printing results with small unevenness can be obtained.

JP 2005-199457 A

By the way, when the recording paper in the above prior art is replaced with a reflective sheet, UV ink on the surface of the reflective sheet generally does not penetrate, and thus the diffusion degree of the UV ink tends to be extremely small compared to the recording paper.

Therefore, if measures such as slowing the ink head moving speed to reduce the UV ink interval or increasing the amount of UV ink to be ejected to reduce the UV ink interval are not taken, The problem was that the printing trend would be large and poorly glossy. Such a problem becomes apparent when the above measures cannot be taken.

Therefore, an object of the present invention is to provide a method for producing a reflective sheet that can easily produce a reflective sheet with a marking portion having better gloss.

In order to solve such a problem, the present invention is a method for manufacturing a reflective sheet with a marking portion, and is a method for producing a photocurable ink in an uncured state while moving an ejector from one end to the other end in a scanning direction. A first ejection step of sequentially ejecting one droplet onto the surface of the reflection sheet; and attaching the droplet to the rear side in the moving direction of the projecting body while moving the projecting body from the other end to the one end in the scanning direction And a second ejection step of sequentially ejecting the second droplets of the photocurable ink in an uncured state while being in contact with the first droplets. It is.

According to such a manufacturing method, when the projecting body moves from one end to the other end, the first droplets are sequentially ejected without being irradiated with light, so that the diffusion of the first droplet proceeds after the ejection. To go. On the other hand, when the projecting body returns from the other end to the other end, the second liquid droplets are sequentially ejected in a state where light is irradiated from the rear of the projecting body, so that the second liquid droplet and the first liquid droplet are caused by the light. Cured. At this time, since the second droplet is ejected in a state of touching the first droplet, the diffusion of the first droplet that is in an uncured state at the time of ejection is an impact when the second droplet is touched. It will increase more due to such factors. That is, the second droplet acts as a droplet that promotes diffusion of the first droplet. Therefore, even if the target of droplet ejection is not the paper but the surface of the reflection sheet, the droplet can be smoothed without changing the moving speed of the ejector and the size of the droplet. In this way, a reflective sheet with a marking portion having better glossiness can be easily produced.

In the first ejection step, it is preferable that the first droplet is ejected in a state where a part of the first droplets adjacent to each other overlap each other.

In this case, the first droplet itself is easily diffused until the second droplet is ejected. For this reason, the time until the uncured photocurable droplets are smoothed is significantly reduced as compared with the case where the first droplets adjacent to each other are sequentially ejected without overlapping each other. Can do.

In the second ejection step, it is preferable that the second droplet is ejected at the same position as the ejection position of the first droplet.

In this case, the smoothing time of the photocurable droplet can be shortened as compared with the case where the second droplet is ejected between the first droplets adjacent to each other.

Also, the present invention can be applied when the first droplet and the second droplet have the same single color. In this case, if the second droplet is ejected at the same position as the ejection position of the first droplet, the color of the reflected light can be made darker without degrading the resolution.

Further, the present invention is a method of manufacturing a reflective sheet with a marking portion, wherein a light illuminator attached to the rear side in the moving direction of the projecting body while moving the projecting body from one end to the other end in the scanning direction. And an ejection step of sequentially ejecting light curable ink droplets in an uncured state, and in the ejection step, the droplets to be ejected are changed to the droplets ejected immediately before the ejection target. It is ejected in a touched state.

According to such a manufacturing method, since the droplets are sequentially ejected in a state where light is irradiated from behind the projecting body, the droplets are cured by the light. At this time, since the droplet to be ejected is ejected in a state of touching the droplet ejected immediately before the ejection target, the diffusion of the droplet ejected immediately before the ejection is performed when the droplet to be ejected is touched. It increases more due to the impact of the. That is, the droplet to be ejected acts as a droplet that promotes diffusion of the droplet ejected immediately before the ejection target. Therefore, even if the target of droplet ejection is not the paper but the surface of the reflection sheet, the droplet can be smoothed without changing the moving speed of the ejector and the size of the droplet. In this way, a reflective sheet with a marking portion having better glossiness can be easily produced.

As described above, according to the present invention, a reflective sheet with a marking portion having better glossiness can be produced.

It is the schematic which looked at the printing apparatus in 1st Embodiment from the side. It is a flowchart which shows the manufacturing method of the reflective sheet in 1st Embodiment. It is a figure which shows the mode of the 1st injection | emission process in 1st Embodiment from the viewpoint similar to FIG. It is a figure which shows the mode of the 2nd injection | emission process in 1st Embodiment from the viewpoint similar to FIG. It is the schematic which looked at the printing apparatus in 2nd Embodiment from the side. It is a figure which shows the mode of the 1st injection | emission process in 2nd Embodiment from the viewpoint similar to FIG. It is a figure which shows the mode of the 2nd injection | emission process in 2nd Embodiment from the viewpoint similar to FIG.

(1) First Embodiment A first embodiment according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic view of the printing apparatus according to the first embodiment viewed from the side. As shown in FIG. 1, the printing apparatus 1 in this embodiment includes a stage 10, a print head 20, and a light irradiation body 30 as main components.

The stage 10 is a seat portion on which the reflective sheet ST is disposed, and the reflective sheet ST is disposed on the stage surface of the stage 10 by, for example, a rail type conveyor.

The type of the reflection sheet ST includes, for example, a prism type reflection sheet or a minute glass sphere type reflection sheet. In addition, as long as the reflection sheet ST has retroreflection performance, various types of reflection sheets ST can be applied. In FIG. 1, the reflective sheet ST is simplified as a rectangular parallelepiped.

The print head 20 is an ejector that ejects droplets (hereinafter referred to as UV ink droplets) of an ultraviolet curable resin (hereinafter referred to as UV ink) containing a pigment or dye, and includes a plurality of nozzles 21A to 21C and a main body. 22. In addition, it is more preferable to apply what has a light transmittance as UV ink from a viewpoint of utilizing effectively the retroreflection performance of reflection sheet ST.

The nozzles 21A to 21C are attached to the main body 22 in a state of being arranged in a line. The exits of these nozzles 21A to 21C are opposed to one surface of the reflection sheet ST (hereinafter referred to as the exit surface) EJS disposed on the stage 10 at a predetermined distance.

The main body 22 detachably holds a cartridge containing a plurality of types of UV inks, and sends these UV inks to the nozzles 21A to 21C corresponding to the types, so that a predetermined color can be obtained from the outlets of the nozzles 21A to 21C. It is comprised so that a tinged UV ink drop can be ejected.

The main body 22 is configured to be movable in a direction corresponding to each dot row (hereinafter referred to as a dot row) when the exit surface EJS of the reflection sheet ST is broken into a matrix.

Specifically, the main body 22 scans, for example, a vertical dot row for each row, and a direction D1 and the other end from the one end side to the other end side of the dot row to be scanned (hereinafter referred to as the forward direction). Reciprocates in a direction from the side toward the one end side (hereinafter referred to as a return direction) D2. At this time, the arrangement direction of the nozzles 21A to 21C coincides with the direction of the dot row, and the movement path of the nozzles 21A to 21C is set above the dot row.

The light irradiation body 30 is an irradiation source that irradiates ultraviolet rays toward the exit surface EJS of the reflection sheet ST, and is attached to the main body 22. This attachment position is located behind the nozzles 21A to 21C of the print head 20 that moves in the return path direction D2.

Using such a printing apparatus 1, a marking portion is attached to the exit surface EJS of the reflection sheet ST.

FIG. 2 is a flowchart showing a manufacturing method of the reflection sheet in the first embodiment. As shown in FIG. 2, the manufacturing method of the reflective sheet with a marking portion in the present embodiment includes an arrangement step P1, a first injection step P2, and a second injection step P3 as main steps.

<Arrangement process P1>
This arrangement process P1 is a process of arranging the reflection sheet ST to be printed. Specifically, the reflective sheet ST is conveyed by, for example, a rail-type conveyor, the reflective sheet ST is set on the stage 10 that is the movable range of the print head 20, and a plurality of the reflective surfaces ST on the exit surface EJS. Dots are assigned.

<First injection process P2>
This first ejection step P2 is a step in which the first UV ink droplets in an uncured state are sequentially ejected onto the ejection surface EJS of the reflection sheet ST while moving the print head 20 in the forward direction D1.

Specifically, as a first stage, a dot row to be scanned is designated from a plurality of dot rows in the vertical direction of each dot assigned to the exit surface EJS of the reflection sheet ST, for example.

As a second stage, as shown in FIG. 3A, the main body 22 of the print head 20 is disposed at the forward path start position on the scanning line corresponding to the dot row designated as the scanning target, and the forward direction D1 is defined. The movement of the main body 22 of the print head 20 is started.

As a third stage, as shown in FIG. 3B, the first UV ink droplet ID1 is sequentially ejected from the nozzles of the print head 20 in a moving state to each dot constituting the dot row to be scanned. . At this time, a part of the first UV ink droplets ID1 adjacent to each other overlap each other.

As the fourth stage, as shown in FIG. 3C, when the print head 20 is moved to the forward path end position on the scanning line corresponding to the dot row to be scanned, the movement of the print head 20 is stopped. .

<Second injection process P3>
In the second ejection step P3, the light irradiation body 30 is turned on while moving the print head 20 in the backward direction D2, and the second UV ink droplet ID2 in an uncured state is converted into the first UV ink droplet. It is a process of injecting sequentially while touching ID1.

Specifically, as shown in FIG. 4A, as a first stage, the light irradiation body 30 is turned on at the forward path end position, and then the print head in the backward path direction D2 with the forward path end position as the backward path start position. 20 moves are started.

Note that the first UV ink droplet ID1 diffuses from the time when it is ejected in the first ejection step P2, and the surface of each first UV ink droplet ID1 tends to be in a smooth state.

As a second stage, as shown in FIG. 4B, the second UV ink droplet ID2 is located at the same position as the position where the first UV ink droplet ID1 is ejected from the nozzles of the print head 20 in the moving state. Are injected sequentially. At this time, the UV ink droplets ID1 and ID2 positioned on the rear side of the print head 20 are cured by irradiation of ultraviolet rays from the light irradiation body 30 attached to the rear side of the print head 20.

In the present embodiment, the size of the second UV ink droplet ID2 is the same as that of the first UV ink droplet ID1, and the color and pigment concentration of the second UV ink droplet ID2 are also the same as those of the first UV ink droplet ID1. It is the same.

As the third stage, as shown in FIG. 4C, when the print head 20 is moved to the forward path start position in the first injection step P2, the print head 20 is moved with the forward path start position as the backward path end position. While being stopped, the light irradiation body 30 is turned off.

In this way, the first injection step P2 and the second injection step P3 are repeated for each dot row, the indication portion is attached to the emission surface EJS of the reflection sheet ST, and the reflection sheet with the indication portion is manufactured.

As described above, in the manufacturing method with a marking portion of the present embodiment, as shown in FIG. 3, when the print head 20 moves in the forward direction D1, the first UV ink droplet ID1 is sequentially emitted without being irradiated with ultraviolet rays. Is done. For this reason, the diffusion of the first UV ink droplet ID1 proceeds.

On the other hand, as shown in FIG. 4, when the print head 20 returns to the return path direction D <b> 2, the second UV ink droplet ID <b> 2 is sequentially ejected in a state where ultraviolet rays are irradiated from the rear of the print head 20. Therefore, the first UV ink droplet ID1 and the second UV ink droplet ID2 are cured by ultraviolet rays.

At this time, since the second UV ink droplet ID2 is ejected while being in contact with the first UV ink droplet ID1, the diffusion of the first UV ink droplet ID1 that is in an uncured state at the time of ejection is the first. It increases further due to an impact when the second UV ink droplet ID2 is touched. That is, the second UV ink droplet ID2 acts as a droplet that promotes diffusion of the first UV ink droplet ID1.

Therefore, even if the UV ink droplets ID1 and ID2 are ejected not on paper but on the ejection surface EJS of the reflective sheet ST, the speed of the print head 20 and the size of the UV ink droplets ID1 and ID2 are not changed. The cured UV ink droplets ID1 and ID2 can be smoothed. In this way, a reflective sheet with a marking portion having better glossiness can be easily produced.

Note that the above-described action occurs even in the state where the first UV ink droplets ID1 adjacent to each other do not overlap. For this reason, when the first UV ink droplet ID1 cannot be overlapped with each other, the second UV ink droplet ID2 is caused to act as a droplet that promotes the diffusion of the first UV ink droplet ID1. Useful.

In the case of this embodiment, the first UV ink droplet ID1 is sequentially ejected in a state where a part of the first UV ink droplet ID1 adjacent to each other overlaps.

In this case, the first UV ink droplet ID1 itself is easily diffused until the second UV ink droplet ID2 is ejected. For this reason, the time until the uncured UV ink droplets ID1 and ID2 are smoothed is significantly larger than in the case where the first UV ink droplets ID1 adjacent to each other are sequentially ejected without overlapping each other. Can be shortened.

In the case of this embodiment, the second UV ink droplet ID2 is ejected at the same position as the ejection position of the first UV ink droplet ID1.

In this case, as compared with the case where the second UV ink droplet ID2 is ejected between the first UV ink droplet ID1 adjacent to each other, the smoothing time of the UV ink droplet ID1 and ID2 is shortened, and the indication is performed. It becomes possible to darken the color of the light reflected from the reflection sheet with a part.

It should be noted that such an effect can be obtained without impairing the resolution when the first UV ink droplet ID1 and the second UV ink droplet ID2 are the same single color as in this embodiment.

(2) Second Embodiment Next, a second embodiment according to the present invention will be described in detail with reference to the drawings. However, among the components of the printing apparatus according to the second embodiment, the same or equivalent components as those of the first embodiment are denoted by the same reference numerals, and redundant descriptions are omitted as appropriate.

FIG. 5 is a schematic view of the printing apparatus according to the second embodiment viewed from the side. As shown in FIG. 5, the printing apparatus 1 according to the present embodiment has the same configuration as that of the first embodiment, except that the light irradiation body 40 is newly attached at a position different from the light irradiation body 30. The

The light irradiator 40 is attached to the rear side of the nozzles 21A to 21C of the print head 20 moving in the forward direction D1, and is located behind the nozzles 21A to 21C of the print head 20 moving in the backward direction D2. It differs from the attached light irradiation body 30.

Next, the manufacturing method of the reflective sheet with a marking part in this embodiment will be described. In the manufacturing method of the present embodiment, the process contents of the first injection process P2 and the second injection process P3 are different from the manufacturing method of the first embodiment.

<First injection process P2>
The first ejection step P2 in the present embodiment is a step in which the light irradiation body 40 is turned on while the print head 20 is moved in the forward direction D1, and the first UV ink droplet ID1 in an uncured state is sequentially ejected. is there. In this step, the first UV ink droplet ID1 to be ejected is ejected while touching the first UV ink droplet ID2 ejected immediately before the ejection object.

As a second stage, as shown in FIG. 6A, the print head 20 is disposed at the forward path start position on the scanning line corresponding to the dot row designated as the scan target, and the light irradiation body 40 is located at the forward path start position. Lights up. Thereafter, the print head 20 starts to move in the forward direction D1.

As a third stage, as shown in FIG. 6B, the first UV ink droplet ID1 is sequentially applied from the nozzles 21A to 21C of the print head 20 in the moving state to each dot constituting the scan target dot row. It is injected. At this time, the first UV ink droplet ID1 to be ejected is ejected while touching the first UV ink droplet ID1 ejected immediately before the ejection target, and is a light irradiator attached to the rear side of the print head 20. Cured by irradiation of ultraviolet rays from 40.

As a fourth stage, as shown in FIG. 6C, when the print head 20 is moved to the forward path end position on the scanning line corresponding to the dot row to be scanned, the movement of the print head 20 is stopped. At the same time, the light irradiation body 40 is turned off.

As described above, the first injection process P2 of the present embodiment is that the light irradiation body 40 on the rear side of the print head 20 moving in the forward direction D1 is turned on, and the light irradiation body 40 is not turned on, and the forward pass is performed. This is different from the first injection process P2 of the first embodiment in which the print head 20 is moved in the direction D1.

<Second injection process P3>
The second ejection step P3 in the present embodiment is a step in which the light irradiation body 30 is turned on while the print head 20 is moved in the backward direction D1, and the second UV ink droplet ID2 in an uncured state is sequentially ejected. is there. Even in this step, the second UV ink droplet ID2 to be ejected is ejected while touching the second UV ink droplet ID2 ejected immediately before the ejection target.

Specifically, as a first stage, a dot row different from the dot row designated as the scanning target in the first ejection step P2 is newly designated as the dot row to be scanned.

As a second stage, as shown in FIG. 7A, the print head 20 is arranged with the start position on the scan line corresponding to the dot row newly designated as the scan target as the return path start position. The light irradiator 30 is turned on. Thereafter, the movement of the print head 20 is started in the backward direction D2.

As a third stage, as shown in FIG. 7B, the second UV ink droplet ID2 is sequentially applied from the nozzles 21A to 21C of the print head 20 in a moving state to each dot constituting the scan target dot row. It is injected. At this time, the second UV ink droplet ID2 to be ejected is ejected in a state of touching the second UV ink droplet ID2 ejected immediately before the ejection target and is attached to the rear side of the print head 20. It is cured by irradiation with ultraviolet rays from 30.

As a fourth stage, as shown in FIG. 7C, when the print head 20 is moved to the return path end position on the scan line corresponding to the dot row to be scanned, the movement of the print head 20 is stopped. At the same time, the light irradiation body 30 is turned off.

As described above, the second ejection step P3 of the present embodiment targets the same scanning line in that the print head 20 is moved in the backward direction D2 with respect to the scanning line different from the scanning line moved in the forward direction D1. This is different from the second injection process P3 of the first embodiment in which the print head 20 is reciprocated.

As described above, in the manufacturing method with a marking portion of the present embodiment, as shown in FIG. 6 or FIG. 7, while moving the print head 20 from one end to the other end in the scanning direction, While the light irradiation body 40 (or 30) attached to the rear side is turned on, the UV ink droplet ID2 (or ID1) is sequentially ejected.

Specifically, the UV ink droplet ID2 (or ID1) to be ejected is ejected while touching the UV ink droplet ID2 (or ID1) ejected immediately before the ejection target.

For this reason, the diffusion of the UV ink droplet ID2 (or ID1) ejected immediately before increases further due to an impact or the like when the UV ink droplet ID2 (or ID1) to be ejected is touched. That is, the UV ink droplet ID2 (or ID1) to be ejected acts as a droplet that promotes diffusion of the UV ink droplet ID2 (or ID1) ejected immediately before the ejection target.

Therefore, even if the light-curing droplet is ejected from the surface of the reflection sheet instead of paper, the UV ink droplet is not changed without changing the speed of the print head 20 or the size of the UV ink droplet ID2 (or ID1). ID2 (or ID1) can be smoothed. In this way, a reflective sheet with a marking portion having better glossiness can be easily produced.

(3) Other Embodiments The above embodiment has been described above as an example, but the present invention is not limited to the above embodiment.

For example, in the above embodiment, the dot rows to be scanned are designated for each row. However, only a part of the dot rows may be designated as a dot row to be scanned, and an intermediate portion of all the dot rows or an intermediate portion of a part of the dot rows is designated as a dot row to be scanned. May be. Further, a dot row to be scanned may be specified in units of two or more rows.

Further, in the above embodiment, droplets having UV curable properties (UV ink droplets) were ejected. However, as long as the droplet has a property of changing from a liquid state to a solid by the action of light energy, various droplets can be applied without being limited to the droplets having ultraviolet curing properties.

In the above embodiment, the first UV ink droplet ID1 is ejected in a state where the adjacent first UV ink droplet ID1 overlaps each other. However, the first UV ink droplet ID1 may be ejected in a state where parts of the surfaces of the first UV ink droplet ID1 adjacent to each other are in contact with each other. In this way, it is possible to shorten the time until the uncured UV ink droplets ID1 and ID2 are smoothed while suppressing a decrease in resolution. In the first embodiment, the first UV ink droplet ID1 may be ejected while the first UV ink droplet ID1 adjacent to each other are not in contact with each other.

In the above embodiment, the first UV ink droplet ID1 and the second UV ink droplet ID2 have the same single color, but the first UV ink droplet ID1 and the second UV ink droplet ID2 have different colors. Or may be multi-colored.

In the first embodiment, the second UV ink droplet ID2 is ejected at the same position as the first UV ink droplet ID1, but it may be ejected between the first UV ink droplet ID1 adjacent to each other. good. In the first embodiment, the second UV ink droplet ID2 having a size smaller than the first UV ink droplet ID1 is ejected to a portion where the first UV ink droplet ID1 adjacent to each other overlaps each other. In this case, it is possible to reduce the time until the uncured UV ink droplets ID1 and ID2 are smoothed while suppressing the ink amount.

In the first embodiment, the first injection process P2 and the second injection process P3 are executed once, but the first injection process P2 may be repeatedly executed twice or more.

In the second embodiment, the print head 20 is moved in the backward direction D2 for a scanning line different from the scanning line moved in the forward direction D1, but the same scanning line as the scanning line moved in the forward direction D1 is used. The print head 20 may be moved in the backward direction D2 with respect to the target. When the print head 20 is moved in the backward direction D2 with the same scanning line as the scanning line moved in the forward direction D1, the second UV ink droplet ID2 is ejected and the light irradiation body 30 is turned on. That can be omitted. That is, when the print head 20 moves in the backward direction D2, it may only return to the start position of the forward path.

Hereinafter, the contents of the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these.

Example 1
First, with the UV lamp of the MUTOH (E) UV curable ink jet printer (trade name, Zepher) turned off, the UV ink was applied to the print medium ejection surface while moving the carriage in the forward direction at a speed of 375 mm / sec. Drops were sequentially ejected (corresponding to the first ejection process of the first embodiment). Note that the UV ink droplets are ejected in a state where some of the adjacent UV ink droplets overlap each other.

The printing medium was a reflective sheet (trade name, Nikkalite 92802) manufactured by Nippon Carbide Industries Co., Ltd., and the UV ink was a UV curable red ink (trade name, ADH-FLEX200RED) manufactured by The Inktec Co., Ltd.

Next, in a state where a UV lamp (hereinafter referred to as a first trailing lamp) attached to the rear side of the carriage in the return direction of the printer is lit, the carriage is moved in the return direction at a speed of 375 mm / sec. The UV ink droplet was ejected at the same position as the ejection position of the first ejection step, and the UV ink droplet was cured (corresponding to the second ejection step of the first embodiment).

After the first injection step and the second injection step are repeated in units of dot rows to obtain a reflection sheet with a target marking portion, the glossiness and retroreflection performance of the reflection sheet with the marking portion are obtained. And measured.

In addition, the glossiness is 60 ° glossiness at 5 points on the surface of the marking portion side of the reflective sheet with the marking portion using a digital variable gloss meter (model UGV-5) manufactured by Suga Test Instruments Co., Ltd. according to JIS Z8741. The average value was measured as the glossiness.

The retroreflection performance was measured on behalf of the front retroreflection performance. This front retroreflective performance is measured by using the “Model 920” manufactured by Advanced RetroTechnology, Inc., and the retroreflective performance at five points on the surface of the marking portion side of the reflective sheet with the marking portion. The measurement was performed under the conditions of 0.2 ° and an incident angle of 5 °, and the average value was defined as retroreflective performance.

(Example 2)
In the same printer as in the first embodiment, with the UV lamp attached to the rear side in the forward direction of the carriage (hereinafter referred to as the second trailing lamp) turned on, the carriage is moved in the forward direction at a speed of 200 mm / sec. However, the same UV ink droplets as in Example 1 were sequentially ejected onto the same print medium ejection surface as in Example 1 (corresponding to the first ejection process of the second embodiment). Note that the UV ink droplets are ejected in a state where some of the adjacent UV ink droplets overlap each other.

Next, with the UV lamp of the carriage turned off, the carriage was moved in the backward direction at a speed of 1000 mm / sec without ejecting UV ink droplets. In other words, in the return path, the carriage is simply returned to the start position of the forward path.

(Example 3)
While the UV lamp in the same printer as in the first embodiment is turned off, the carriage is moved in the forward direction at a speed of 750 mm / sec. UV ink droplets were sequentially ejected (corresponding to the first ejection step of the first embodiment). Note that the UV ink droplets are ejected in a state where some of the adjacent UV ink droplets overlap each other.

Next, with the UV lamp turned off, UV ink droplets were ejected at the same position as the ejection position in the first ejection step while moving the carriage in the backward direction at a speed of 750 mm / sec. Note that the UV ink droplets are ejected in a state where some of the adjacent UV ink droplets overlap each other.

Next, with the second trailing lamp turned on, while moving the carriage in the forward direction at a speed of 380 mm / sec, a UV ink droplet is ejected to the same position as the ejection position in the first ejection process, and the UV ink The droplet was cured (corresponding to the second ejection step of the first embodiment).

(Example 4)
The fourth embodiment is the same as the first embodiment except that the speed of the carriage moved in the forward direction and the backward direction is changed to 450 mm / sec.

(Example 5)
Example 5 is the same as Example 1 except that the UV ink is replaced with a UV curable blue ink (trade name, ADH-FLEX200BLUE) manufactured by The Inktec Co., Ltd.

(Example 6)
Example 6 is the same as Example 2 except that the UV ink is replaced with a UV curable blue ink (trade name, ADH-FLEX200BLUE) manufactured by The Inktec Co., Ltd.

(Example 7)
Example 7 is the same as Example 3 except that the UV ink is replaced with a UV curable blue ink (trade name, ADH-FLEX200BLUE) manufactured by The Inktec Co., Ltd.

(Example 8)
Example 8 is the same as Example 4 except that the UV ink is replaced with a UV curable blue ink (trade name, ADH-FLEX200BLUE) manufactured by The Inktec Co., Ltd.

(Comparative Example 1)
First, in a state where the second trading lamp in the same printer as in the first embodiment is turned on, UV ink droplets are ejected onto the ejection surface of the print medium while moving the carriage in the forward direction at a speed of 500 mm / sec. The drop was cured (first step). This printing medium and UV ink are the same as those in the first embodiment.

Note that the UV ink droplets are ejected in a state where the UV ink droplets adjacent to each other are not separated from each other with a gap. That is, the difference is that the UV ink droplets are ejected toward the reflection sheet so as not to overlap in Comparative Example 1, whereas the UV droplets are ejected toward the reflection sheet so as to overlap in the above embodiment. However, in Comparative Example 1, the UV ink droplets ejected toward the reflection sheet so as not to overlap each other, and the UV ink droplets adjacent to each other due to the collision of the UV ink droplets with the reflection sheet are not combined. is there.

Next, in a state where the second trading lamp is turned off and the first trailing lamp is turned on, the UV ink droplet is put on the same position as the ejection position in the first step while moving the carriage in the backward direction at a speed of 500 mm / sec. The UV ink droplets were ejected and cured (second step).

After the first step and the second step are repeated for each dot row to obtain a reflection sheet with a target marking portion, the glossiness and retroreflection performance of the reflection sheet with the marking portion are obtained. It was measured.

(Comparative Example 2)
The comparative example 2 is the same as the comparative example 1 except that the carriage is merely returned to the starting position of the forward path in the return path.

(Comparative Example 3)
In this comparative example 3, the UV lamp located on the front side in the forward direction of the carriage is lit on the forward path, and the UV lamp located on the front side in the backward direction of the carriage is lit on the return path. Except for this, it is the same as Comparative Example 1 above.

(Comparative Example 4)
Comparative Example 4 is the same as Comparative Example 1 except that the UV ink is replaced with a UV curable blue ink (trade name, ADH-FLEX200BLUE) manufactured by The Inktec Co., Ltd.

(Comparative Example 5)
The comparative example 5 is the same as the comparative example 2 except that the UV ink is replaced with a UV curable blue ink (trade name, ADH-FLEX200BLUE) manufactured by The Inktec Co., Ltd.

(Comparative Example 6)
The comparative example 6 is the same as the comparative example 3 except that the UV ink is replaced with a UV curable blue ink (trade name: ADH-FLEX200BLUE) manufactured by The Inktec Co., Ltd.

Table 1 below shows the measurement results of the glossiness (gloss) and retroreflection performance (luminance) (cd / lx · m ² ) measured in Examples 1 to 8 and Comparative Examples 1 to 6. Show.

As is apparent from Table 1, the example to which the present invention is applied (when the droplets ejected in a state where a part of the droplets are overlapped) is more comparative example (one droplet). It was found that a reflective sheet with a marking portion having better glossiness and retroreflective performance can be produced as compared to a case where a droplet ejected in a state where the portions do not overlap with each other.

In addition, the reflection with a marking portion in which the first embodiment to which the first embodiment of the present invention is applied has better glossiness and retroreflective performance than the second embodiment to which the second embodiment of the present invention is applied. It has been found that a sheet can be produced. The first embodiment also has an advantage that the printing speed is faster than that of the second embodiment.

The method for manufacturing a reflective sheet with a marking portion according to the present invention has applicability in various industries in which a marking portion is attached to the reflective sheet.

DESCRIPTION OF SYMBOLS 1 ... Printing apparatus 10 ... Stage 20 ... Print head 21A-21C ... Nozzle 22 ...

Main body

30, 40 ... Light irradiation body D1 ... Outward direction D2 ... Return way direction ID1 ... 1st UV ink drop ID2 ... 2nd UV ink drop P1 ... Arrangement process P2 ... 1st ejection process P3 ... 2nd ejection process

Claims

A first ejection step of sequentially ejecting first droplets of uncured photocurable ink onto the surface of the reflection sheet while moving the ejector from one end to the other end in the scanning direction;
While moving the ejection body from the other end to the one end in the scanning direction, the light irradiation body attached to the rear side in the movement direction of the ejection body is turned on and the photocurable ink is in an uncured state And a second ejection step of sequentially ejecting the second droplets in a state where the second droplets are in contact with the first droplets.
In the first injection step,
2. The method for manufacturing a reflective sheet with a marking portion according to claim 1, wherein the first liquid droplets are ejected in a state where a part of the first liquid droplets adjacent to each other overlap each other.
In the second injection step,
The method for manufacturing a reflective sheet with a marking portion according to claim 1 or 2, wherein the second droplet is ejected at the same position as the ejection position of the first droplet.
The method for producing a reflective sheet with a marking portion according to any one of claims 1 to 3, wherein the first droplet and the second droplet have the same single color.
While moving the ejector from one end to the other end in the scanning direction, the light irradiator attached to the rear side in the moving direction of the ejector is turned on, and droplets of the photocurable ink in an uncured state are ejected. It has an injection process that sequentially injects,
In the ejection step, the droplet to be ejected is ejected while being in contact with the droplet ejected immediately before the ejection target.