JP5948017B2 - Drawing device - Google Patents

Description

  The present invention relates to a drawing apparatus that discharges a liquid material toward a drawing medium and places and draws the liquid material on the drawing medium.

  2. Description of the Related Art Conventionally, a drawing apparatus that includes a discharge head that discharges a liquid material and draws an arbitrary image or the like on a drawing medium by landing discharged liquid droplets on an arbitrary position of the drawing medium is known. . For example, a drawing apparatus including an ink jet type ejection head can accurately arrange a predetermined amount of a liquid material at a predetermined position. Many of such ejection heads have a problem that when the dissolved gas dissolved in the liquid increases, normal ejection becomes difficult, and the accuracy of the ejection amount and landing position is likely to be impaired.

  Patent Document 1 discloses a printing apparatus that is provided with a decompression mechanism to degas dissolved gas from ink in an external ink tank of an ink circulation mechanism.

JP 2009-285839 A

  However, the degassing device such as the decompression mechanism described in Patent Document 1 degass the dissolved gas and may reduce the additive added to the liquid. For example, in a UV curable functional liquid, a polymerization inhibitor is added in order to prevent the functional liquid from solidifying inside the drawing apparatus. The degassing device such as the decompression mechanism described in Patent Document 1 is such that the polymerization inhibitor and oxygen are reduced from the circulating functional liquid, so that the functional liquid is easily reacted, and the inside of the drawing apparatus. There was a problem that it was easy to solidify. As described above, there is a problem that a possibility that a problem occurs is increased by the liquid material in which the additive is reduced by the degassing device staying in the drawing device.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A drawing apparatus according to this application example includes a discharge head that discharges a liquid material, discharges the liquid material from the discharge head toward a drawing medium, and the liquid material is placed on the drawing medium. A drawing tank for storing the liquid material, connected to the storage tank for storing the liquid material, the storage tank and the connection portion, and a path through which the liquid material is sent from the storage tank to the connection portion. One supply path, connected to the storage tank and the connection portion, a circulation flow path that is a path through which the liquid material is sent from the connection portion to the storage tank, and the connection portion and the discharge head A second supply path that is connected and is a path through which the liquid material is supplied from the connection portion to the discharge head; and a degassing unit that degass the dissolved gas in the liquid material, The means is disposed in the second supply path. And said that you are.

  According to the drawing apparatus according to this application example, most of the liquid material stored in the drawing apparatus for discharging from the discharge head is a circulation flow including the storage tank, the first supply path, the connection portion, and the circulation flow path. The road can be made to flow. The liquid just before being supplied to the discharge head stays in the second supply path. Since the deaeration means is disposed in the second supply path, the liquid material deaerated by the deaeration means exists only in the portion between the deaeration means and the ejection head in the second supply path. The liquid material in the portion is a liquid material just before being replenished to the discharge head and discharged. Thereby, the time for the liquid material deaerated by the deaeration means to remain in the drawing apparatus can be suppressed. That is, for example, it is possible to suppress the time that the liquid that has been easily reacted by reducing the polymerization inhibitor or oxygen stays in the drawing apparatus.

  Application Example 2 In the drawing apparatus according to the application example, it is preferable that the liquid material is a radical polymerization type ultraviolet curable ink.

  According to this drawing apparatus, the liquid used is a radical polymerization type ultraviolet curable ink. The radical polymerization type ink contains a radical polymerization initiator. By using the radical polymerization initiator, since the polymerization is not inhibited by humidity as in the case of cationic polymerization, the restriction of the printing environment can be reduced.

  Application Example 3 In the drawing apparatus according to the application example, the dissolved gas concentration of the dissolved gas in the liquid material in the first supply channel and the circulation channel is higher than the dissolved gas concentration in the discharge head. It is preferable.

  According to this drawing apparatus, the dissolved gas concentration of the dissolved gas in the liquid in the first supply channel and the circulation channel is higher than the dissolved gas concentration in the ejection head. When the dissolved gas is removed to lower the dissolved gas concentration, there is a high possibility that the additive added to the liquid is also reduced. For example, the liquid inhibitor may be easily solidified by reducing the polymerization inhibitor by degassing. A liquid material having a high dissolved gas concentration is more likely to cause problems such as solidification than a liquid material having a low dissolved gas concentration. The liquid material in the first supply path and the circulation channel in which the liquid material stays longer than the discharge head or the like can be maintained in a state in which it is more difficult to solidify than the liquid material in the discharge head.

  Application Example 4 The drawing apparatus according to the application example further includes a pressure adjusting unit that adjusts the pressure of the liquid material in the discharge head, and the pressure adjusting unit includes the deaeration unit in the second supply path. It is preferable to be disposed between the ejection head.

  According to this drawing apparatus, the pressure adjusting means is disposed between the degassing means and the ejection head, and the liquid whose pressure is adjusted by the pressure adjusting means is the liquid degassed by the degassing means. Is the body. Thereby, it can suppress that the pressure of a liquid material deviates from the adjusted pressure because the liquid material by which the pressure was adjusted by the pressure adjustment means is deaerated by the deaeration means.

FIG. 3 is an external perspective view showing a schematic configuration of the entire droplet discharge device. FIG. 3A is an external perspective view showing a schematic configuration of a droplet discharge head. (B) is a perspective sectional view showing the structure of a droplet discharge head. FIG. 6C is a cross-sectional view showing the structure of the discharge nozzle portion of the droplet discharge head. FIG. 2 is a plan view showing a schematic configuration of a head unit. The schematic diagram which shows the structure of a functional liquid supply part.

  The drawing apparatus will be described below with reference to the drawings. In the present embodiment, a droplet discharge device as a drawing device will be described as an example. The droplet discharge apparatus is an apparatus including an inkjet droplet discharge head. In the drawings referred to in the following description, the vertical and horizontal scales of members or portions may be shown differently from actual ones for convenience of illustration.

<Droplet ejection device>
Initially, the whole structure of the droplet discharge apparatus 1 is demonstrated with reference to FIG. FIG. 1 is an external perspective view showing a schematic configuration of the entire droplet discharge device.

As shown in FIG. 1, the droplet discharge device 1 includes a head mechanism unit 2, a work mechanism unit 3, a functional liquid supply unit 4, a maintenance device unit 5, a discharge device control unit 6, and support legs 8. And a surface plate 9. The head mechanism unit 2 includes a droplet discharge head 20 that discharges the functional liquid 40 (see FIG. 4) as droplets. The work mechanism unit 3 includes a work mounting table 33 on which a work W that is a discharge target of liquid droplets discharged from the liquid droplet discharge head 20 is mounted.
The functional liquid supply unit 4 includes a functional liquid tank 41, a supply pipe 61 (see FIG. 4), and the like, and the functional liquid 40 is transferred from the functional liquid tank 41 to the droplet discharge head 20 via the supply pipe 61 and the like. Supplied. The maintenance device unit 5 includes each device that performs inspection or maintenance of the droplet discharge head 20. The discharge device control unit 6 comprehensively controls these mechanism units and the like. A plurality of support legs 8 are installed on the floor, and a surface plate 9 is installed on the plurality of support legs 8.

  On the upper surface of the surface plate 9, the work mechanism unit 3 is disposed. The work mechanism unit 3 extends in the longitudinal direction (X-axis direction) of the surface plate 9. Above the work mechanism unit 3, the head mechanism unit 2 supported by two support columns fixed to the surface plate 9 is disposed. The head mechanism unit 2 extends in a direction (Y-axis direction) orthogonal to the work mechanism unit 3. A functional liquid tank 41 of the functional liquid supply unit 4 having a supply pipe that communicates with the droplet discharge head 20 of the head mechanism unit 2 is disposed beside the surface plate 9. In the vicinity of one support column of the head mechanism unit 2, the maintenance device unit 5 is arranged along with the work mechanism unit 3 so as to extend in the X-axis direction. A discharge device controller 6 is accommodated below the surface plate 9.

  The head mechanism unit 2 includes a head unit 21 having a droplet discharge head 20 and a head carriage 22 that supports the head unit 21, and the droplet discharge head 20 is moved by moving the head carriage 22 in the Y-axis direction. Is freely moved in the Y-axis direction. Moreover, it holds at the moved position. The workpiece mechanism unit 3 moves the workpiece mounting table 33 in the X-axis direction to freely move the workpiece W mounted on the workpiece mounting table 33 in the X-axis direction. Moreover, it holds at the moved position.

The droplet discharge head 20 is moved to the discharge position in the Y-axis direction and stopped, and the functional liquid 40 is discharged as droplets in synchronization with the movement of the workpiece W below in the X-axis direction. By relatively controlling the workpiece W moved in the X-axis direction and the droplet discharge head 20 moved in the Y-axis direction, droplets are landed at an arbitrary position on the workpiece W, thereby making a desired drawing. Etc. can be performed.
The work W corresponds to a drawing medium. The droplet discharge head 20 corresponds to the discharge head. The functional liquid 40 corresponds to a liquid material.

  The functional liquid supply unit 4 includes a functional liquid tank 41, a circulation tank 42, a supply pipe 62, a circulation pipe 64, a valve holding frame 44, a switching valve 43, and the like. The functional liquid tank 41 and the circulation tank 42 are arranged beside the surface plate 9. The valve holding frame 44 is fixed to the head carriage 22 of the head mechanism unit 2. The switching valve 43 is fixed to the head carriage 22 via the valve holding frame 44 by being held by the valve holding frame 44. The switching valve 43 fixed to the head carriage 22 moves in the Y-axis direction together with the movement of the droplet discharge head 20 in the Y-axis direction. The circulation tank 42 and the switching valve 43 are connected via a supply pipe 62 and a circulation pipe 64, and the functional liquid 40 is sent to the switching valve 43 via the supply pipe 62. A supply pipe 63 (see FIG. 4) is connected to the switching valve 43, and a deaeration unit 71 (see FIG. 4) described later is attached to the supply pipe 63. The supply pipe 63 is connected to the droplet discharge head 20 via a pressure regulating valve 77 (see FIG. 4) and a liquid distribution pipe 66 (see FIG. 4). The functional liquid 40 is supplied from the switching valve 43 to the droplet discharge head 20 via the supply pipe 63, the deaeration unit 71, the pressure adjustment valve 77, and the liquid distribution pipe 66.

<Droplet ejection head>
Next, the droplet discharge head 20 will be described with reference to FIG. FIG. 2 is a diagram showing a schematic configuration of the droplet discharge head. 2A is an external perspective view showing a schematic configuration of the droplet discharge head, FIG. 2B is a perspective sectional view showing the structure of the droplet discharge head, and FIG. It is sectional drawing which shows the structure of the part of the discharge nozzle of a droplet discharge head. The Y axis and the Z axis shown in FIG. 2 coincide with the Y axis and the Z axis shown in FIG. 1 when the droplet discharge head 20 is mounted on the droplet discharge apparatus 1.

As illustrated in FIG. 2A, the droplet discharge head 20 includes a nozzle substrate 25. In the nozzle substrate 25, two rows of nozzle rows 24A in which a large number of discharge nozzles 24 are arranged in a substantially straight line are formed. The functional liquid 40 is ejected as droplets from the ejection nozzle 24 and landed on a drawing target or the like at an opposing position, whereby the functional liquid 40 is disposed at the position. The nozzle row 24 </ b> A extends in the Y-axis direction shown in FIG. 1 in a state where the droplet discharge head 20 is mounted on the droplet discharge apparatus 1. In the nozzle row 24A, the discharge nozzles 24 are arranged at equal nozzle pitches, and the position of the discharge nozzle 24 is shifted by a half nozzle pitch in the Y-axis direction between the two nozzle rows 24A. Therefore, as the droplet discharge head 20, droplets of the functional liquid 40 can be arranged at half nozzle pitch intervals in the Y-axis direction.
A pair of connecting needles 26 are formed on the opposite side of the droplet discharge head 20 from the nozzle substrate 25. The functional liquid 40 is supplied into the liquid droplet ejection head 20 from the introduction hole formed in the connection needle 26.

As shown in FIGS. 2B and 2C, in the droplet discharge head 20, the pressure chamber plate 51 is stacked on the nozzle substrate 25, and the vibration plate 52 is stacked on the pressure chamber plate 51.
The pressure chamber plate 51 is formed with a liquid pool 55 that is always filled with the functional liquid 40 supplied to the droplet discharge head 20. The liquid pool 55 is a space surrounded by the diaphragm 52, the nozzle substrate 25, and the wall of the pressure chamber plate 51. The functional liquid 40 supplied from the functional liquid supply unit 4 is supplied to the inside of the droplet discharge head 20 from the introduction hole formed in the connection needle 26, and is accumulated through the liquid supply hole 53 of the vibration plate 52. 55 is supplied. Further, the pressure chamber plate 51 is formed with a pressure chamber 58 partitioned by a plurality of head partition walls 57. A space surrounded by the diaphragm 52, the nozzle substrate 25, and the two head partition walls 57 is a pressure chamber 58.

  The pressure chambers 58 are provided corresponding to the respective discharge nozzles 24, and the number of the pressure chambers 58 and the number of the discharge nozzles 24 are the same. The functional liquid 40 is supplied from the liquid pool 55 to the pressure chamber 58 via the supply port 56 positioned between the two head partition walls 57. A set of the head partition wall 57, the pressure chamber 58, the discharge nozzle 24, and the supply port 56 is arranged in a line along the liquid pool 55, and the discharge nozzles 24 arranged in a line form a nozzle line 24A. . Although not shown in FIG. 2B, the discharge nozzles 24 arranged in one row are arranged in a substantially symmetrical position with respect to the liquid pool 55 with respect to the nozzle row 24A including the discharge nozzle 24 shown in the figure. A nozzle row 24A is formed. A set of a head partition wall 57, a pressure chamber 58, and a supply port 56 corresponding to the nozzle row 24A is arranged in one row.

One end of each piezoelectric element 59 is fixed to the portion of the diaphragm 52 that constitutes the pressure chamber 58. The other end of the piezoelectric element 59 is fixed to a base (not shown) that supports the entire droplet discharge head 20 via a fixing plate (not shown).
The piezoelectric element 59 has an active part in which an electrode layer and a piezoelectric material are stacked. In the piezoelectric element 59, by applying a driving voltage to the electrode layer, the active portion contracts in the longitudinal direction (the thickness direction of the diaphragm 52 in FIG. 2B or 2C). When the drive voltage applied to the electrode layer is released, the active portion returns to its original length.

  When the driving voltage is applied to the electrode layer and the active portion of the piezoelectric element 59 is contracted, the vibration plate 52 to which one end of the piezoelectric element 59 is fixed receives a force that is pulled to the side opposite to the pressure chamber 58. When the diaphragm 52 is pulled to the opposite side of the pressure chamber 58, the diaphragm 52 is bent to the opposite side of the pressure chamber 58. Thereby, since the volume of the pressure chamber 58 increases, the functional liquid 40 is supplied from the liquid pool 55 to the pressure chamber 58 through the supply port 56. Next, when the driving voltage applied to the electrode layer is released, the active portion returns to the original length, and the piezoelectric element 59 presses the diaphragm 52. When the diaphragm 52 is pressed, it returns to the pressure chamber 58 side. As a result, the volume of the pressure chamber 58 is rapidly restored. That is, since the increased volume is reduced, pressure is applied to the functional liquid 40 filled in the pressure chamber 58, and the functional liquid 40 drops from the discharge nozzle 24 formed in communication with the pressure chamber 58. And discharged.

<Head unit>
Next, a schematic configuration of the head unit 21 provided in the head mechanism unit 2 will be described with reference to FIG. FIG. 3 is a plan view showing a schematic configuration of the head unit. The X axis and the Y axis shown in FIG. 3 coincide with the X axis and the Y axis shown in FIG. 1 in a state where the head unit 21 is attached to the droplet discharge device 1.

  As shown in FIG. 3, the head unit 21 includes a unit plate 23 and nine droplet discharge heads 20 mounted on the unit plate 23. The droplet discharge head 20 is fixed to the unit plate 23 via a head holding member (not shown). In the fixed droplet discharge head 20, the head body is loosely fitted in a hole (not shown) formed in the unit plate 23, and the nozzle substrate 25 is located at a position protruding from the surface of the unit plate 23. . FIG. 3 is a view as seen from the nozzle substrate 25 side. The nine droplet ejection heads 20 are divided in the Y-axis direction to form three groups of head groups 20A each having three droplet ejection heads 20 each. The nozzle row 24 </ b> A of each droplet discharge head 20 extends in the Y-axis direction when the head unit 21 is attached to the droplet discharge device 1.

In the Y-axis direction, the droplet discharge head 20 is located at the end of the other droplet discharge head 20 with respect to the discharge nozzle 24 at the end of one droplet discharge head 20 of the droplet discharge heads 20 adjacent to each other. The discharge nozzle 24 is disposed at a position where it is shifted by a half nozzle pitch. If the nine droplet discharge heads 20 included in one head unit 21 have the same position in the X-axis direction, the discharge nozzles 24 are arranged at equal intervals of a half nozzle pitch in the Y-axis direction. That is, at the same position in the X-axis direction, the droplets discharged from the discharge nozzles 24 constituting each nozzle row 24A of each droplet discharge head 20 have a half nozzle pitch in the Y-axis direction in design. Land on a straight line at equal intervals.
The nozzle row 24 </ b> A has, for example, 180 ejection nozzles 24, and the droplet ejection head 20 has 360 ejection nozzles 24. The head unit 21 having nine droplet discharge heads 20 has 3240 discharge nozzles 24. When one droplet is discharged from the discharge nozzle 24 of one head unit 21 and landed so that the X-axis direction is at the same position, a straight line is formed in which 3240 points are connected at a pitch interval of a half nozzle pitch.

<Functional liquid supply unit>
Next, the configuration of the functional liquid supply unit 4 will be described in more detail with reference to FIG. FIG. 4 is a schematic diagram illustrating the configuration of the functional liquid supply unit. As shown in FIG. 4, the functional liquid supply unit 4 includes a functional liquid tank 41, a circulation tank 42, a switching valve 43, a deaeration unit 71, a pressure adjustment valve 77, and a pipe connection member 67. ing. Further, a supply pipe 61, a supply pipe 62, a supply pipe 63, and a circulation pipe 64 that supply the functional liquid 40 from the functional liquid tank 41 to the droplet discharge head 20 through communication between the tanks and the droplet discharge head 20. , And a liquid distribution pipe 66. The functional liquid supply unit 4 also includes a pump 73 and a pump 75 that apply pressure to the functional liquid 40 to send the functional liquid 40 from the functional liquid tank 41 to the droplet discharge head 20.

The deaeration unit 71, the pump 73, the pump 75, and the switching valve 43 are electrically connected to the discharge device control unit 6 as shown by the broken line in FIG. 4, and are controlled by the discharge device control unit 6. Is done. As described above, the droplet discharge head 20 is also electrically connected to the discharge device control unit 6 and controlled by the discharge device control unit 6.
The functional liquid tank 41 and the circulation tank 42 communicate with each other via a supply pipe 61. A pump 73 is disposed in the middle of the supply pipe 61. The functional liquid 40 is sent from the functional liquid tank 41 to the circulation tank 42 via the supply pipe 61 by the pump 73. The functional liquid tank 41 is a tank for replenishing the droplet discharge device 1 with the functional liquid. The functional liquid tank 41 may be removed from the functional liquid supply unit 4 except when the functional liquid supply unit 4 is replenished with the functional liquid. Good.
As described above, the valve holding frame 44 is fixed to the head carriage 22 of the head mechanism unit 2. The switching valve 43 is fixed to the head carriage 22 via the valve holding frame 44 by being held by the valve holding frame 44. The switching valve 43 fixed to the head carriage 22 moves in the Y-axis direction together with the movement of the droplet discharge head 20 in the Y-axis direction.

The circulation tank 42 and the switching valve 43 communicate with each other via a supply pipe 62. In addition, communication is made through the circulation pipe 64. A pump 75 is disposed in the middle of the supply pipe 62. The functional liquid 40 is sent from the circulation tank 42 to the switching valve 43 via the supply pipe 62 by the pump 75.
The switching valve 43 is also connected to a supply pipe 63 that is a path for sending the functional liquid toward the droplet discharge head 20. The switching valve 43 switches the flow path communicating with the supply pipe 62 to the circulation pipe 64 or the supply pipe 63. In a state where the flow path communicating with the supply pipe 62 is connected to the circulation pipe 64 by the switching valve 43, the functional liquid 40 supplied to the switching valve 43 passes through the circulation pipe 64 to the circulation tank 42. Returned. A circulation path is formed by the circulation tank 42, the supply pipe 62, the switching valve 43, and the circulation pipe 64, and the functional liquid 40 circulates through the circulation path. When the flow path communicating with the supply pipe 62 is connected to the supply pipe 63 by the switching valve 43, the functional liquid 40 supplied to the switching valve 43 is supplied to the droplet discharge head 20.
By circulating the circulation path through the functional liquid 40, it is possible to suppress sedimentation of pigments contained in the functional liquid 40.
When it is not necessary to supply the functional liquid 40 to the droplet discharge head 20, the functional liquid 40 can be circulated by switching the flow path to the circulation pipe 64 side. When it is necessary to supply the functional liquid 40 to the droplet discharge head 20, the functional liquid 40 is discharged from the droplet discharge head 20 or the functional liquid 40 is sucked from the droplet discharge head 20. This is the case. In other cases, the functional liquid 40 can be circulated. For example, the functional liquid 40 may be circulated also during a rest period or during startup.
Furthermore, in the case where the functional liquid 40 can be circulated, the functional liquid 40 may be circulated as necessary depending on the sedimentation state of the pigment or the like in the functional liquid 40. The sedimentation state of the pigment or the like in the functional liquid 40 is determined from the time during which the functional liquid 40 is ejected from the liquid droplet ejection head 20 or the passage of time after the functional liquid 40 is aspirated from the liquid droplet ejection head 20. Can do.

The switching valve 43 and the pressure adjustment valve 77 communicate with each other via the supply pipe 63. The deaeration unit 71 is fixed to the head carriage 22 by a fixing jig (not shown), and is disposed in the middle of the supply pipe 63. By the deaeration unit 71, bubbles or dissolved gas mixed in the functional liquid 40 passing through the supply pipe 63 can be extracted.
The pressure regulating valve 77 is fixed to and supported by the regulating valve support frame 77a, the regulating valve support frame 77a is fixed to the unit plate 23, and the pressure regulating valve 77 is united via the regulating valve support frame 77a. It is fixed to the plate 23. The pressure adjustment valve 77 adjusts and outputs the fluid pressure of the functional fluid 40 that has flowed into the fluid, for example, using atmospheric pressure. The pressure of the functional liquid 40 supplied to the droplet discharge head 20 is adjusted to a constant pressure by the pressure adjusting valve 77.
The pressure adjustment valve 77 and the droplet discharge head 20 communicate with each other via a liquid distribution pipe 66. The liquid distribution pipe 66 has two liquid droplet ejection heads 20 that are branched into two, and pipe connection members 67 are fixed to the branched ends. The pipe connection member 67 is fitted to the connection needle 26 of the droplet discharge head 20, and the inside of the droplet discharge head 20 and the flow path of the liquid distribution pipe 66 are connected via the introduction hole formed in the connection needle 26. It is communicated.

The functional liquid 40 reaches the circulation tank 42 from the functional liquid tank 41 through the supply pipe 61 and reaches the switching valve 43 from the circulation tank 42 through the supply pipe 62. The functional liquid 40 is held inside the functional liquid supply unit 4 while circulating through a circulation path formed by the circulation tank 42, the supply pipe 62, the switching valve 43, and the circulation pipe 64.
When the functional liquid 40 is discharged from the droplet discharge head 20, the functional liquid 40 is supplied from the switching valve 43 to the droplet discharge head 20 via the supply pipe 63 and the liquid distribution pipe 66. The functional liquid 40 is degassed by a degassing unit 71 arranged in the middle of the supply pipe 63, adjusted to an appropriate pressure by a pressure adjustment valve 77, and supplied to the droplet discharge head 20.
The circulation tank 42 corresponds to a storage tank. The supply pipe 62 corresponds to the first supply path. The switching valve 43 corresponds to a connection part. The circulation pipe 64 corresponds to a circulation channel. The supply pipe 63 and the liquid distribution pipe 66 correspond to the second supply path. The deaeration unit 71 corresponds to a deaeration unit. The pressure adjustment valve 77 corresponds to the pressure adjustment means.

<Ink>
The functional liquid 40 is, for example, ultraviolet curable ink. The composition of the ink in the present embodiment (hereinafter also referred to as “ink composition”) is not particularly limited. When the ink is an ultraviolet curable ink, it contains at least a polymerizable compound and a photopolymerization initiator. Further, when the ink is a colored ink other than the clear ink, a color material is also included. Hereinafter, each component contained in or included in the ink composition will be described.

(Polymerizable compound)
The polymerizable compound is not particularly limited as long as it is a compound that polymerizes and solidifies upon irradiation with ultraviolet rays by the action of a photopolymerization initiator described later. For example, various monomers and oligomers having a monofunctional group, a bifunctional group, and a polyfunctional group having three or more functional groups can be used.

  Here, the “monomer” in the present specification means a molecule having a weight average molecular weight of 100 to 3,000. The “oligomer” in the present specification means a molecule having a weight average molecular weight of 500 to 20,000.

The monomer is not particularly limited. For example, unsaturated carboxylic acids such as (meth) acrylic acid, itaconic acid, crotonic acid, isocrotonic acid and maleic acid, salts or esters thereof, urethane, amide and anhydrides thereof, Examples include acrylonitrile, styrene, various unsaturated polyesters, unsaturated polyethers, unsaturated polyamides, and unsaturated urethanes.
An N-vinyl compound may be included as another monofunctional monomer or polyfunctional monomer. Examples of the N-vinyl compound include N-vinylformamide, N-vinylcarbazole, N-vinylacetamide, N-vinylpyrrolidone, N-vinylcaprolactam, acryloylmorpholine, and derivatives thereof.

  Examples of the oligomer include oligomers formed from the above monomers such as linear oligomers and hyperbranched oligomers, epoxy (meth) acrylates, aliphatic urethane (meth) acrylates, aromatic urethane (meth) acrylates, poly Examples include ether (meth) acrylate and polyester (meth) acrylate.

Among those listed above, esters of (meth) acrylic acid, that is, (meth) acrylates are preferred. When (meth) acrylate is used as the polymerizable compound, the curability of the ink and the adhesion of the cured film to the adherend can be improved.
In the present specification, “(meth) acrylate” means acrylate and its corresponding methacrylate, and “(meth) acryl” means acryl and its corresponding methacryl.

  Among the above (meth) acrylates, monofunctional (meth) acrylates include, for example, isoamyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, iso Myristyl (meth) acrylate, isostearyl (meth) acrylate, 2-ethylhexyl-diglycol (meth) acrylate, 2-hydroxybutyl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxydiethylene glycol ( (Meth) acrylate, methoxypolyethylene glycol (meth) acrylate, methoxypropylene glycol (meth) acrylate, phenoxyethyl (meth) acrylate , Tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, lactone-modifiable Examples include flexible (meth) acrylate, t-butylcyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, and isobornyl (meth) acrylate.

  Among the (meth) acrylates, examples of the bifunctional (meth) acrylate include triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and dipropylene glycol di ( (Meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonane Di (meth) acrylate, neopentyl glycol di (meth) acrylate, dimethylol-tricyclodecane di (meth) acrylate, EO (ethylene oxide) adduct di (meth) acrylate of bisphenol A DOO, PO bisphenol A (propylene oxide) adduct di (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, and polytetramethylene glycol di (meth) acrylate.

  Among the above (meth) acrylates, trifunctional or more polyfunctional (meth) acrylates include, for example, trimethylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, and pentaerythritol tri (meth) acrylate. , Pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, glycerin propoxytri (meth) acrylate, cowprolactone modified trimethylolpropane tri (meth) acrylate, pentaerythritol Examples include ethoxytetra (meth) acrylate and caprolactam-modified dipentaerythritol hexa (meth) acrylate.

  Among these, as the polymerizable compound, a monofunctional (metafunctional) compound is used from the viewpoint that the coating film (coating layer) at the time of curing has high extensibility and low viscosity, so that injection stability at the time of ink jet recording is easily obtained. ) It is preferable to contain an acrylate. Furthermore, it is more preferable to use a monofunctional (meth) acrylate and a bifunctional (meth) acrylate together from the viewpoint of increasing the hardness of the coating layer.

Among the (meth) acrylates listed above, at least one selected from the group consisting of dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, and 1,6-hexanediol acrylate is preferable. At least one of propylene glycol di (meth) acrylate and tripropylene glycol di (meth) acrylate is more preferable. In this case, since the balance of viscosity, curability, and skin irritation is excellent, it is effective for inkjet inks that are easily affected by viscosity during ejection, and skin irritation is also reduced.
The photopolymerizable compound may further contain a conventionally known (meth) acrylate oligomer in addition to the (meth) acrylate monomer.

  Said polymeric compound may be used individually by 1 type, and may use 2 or more types together.

(Photopolymerization initiator)
The polymerization initiator is not particularly limited as long as it generates active species such as radicals and cations by the energy of ultraviolet rays and initiates polymerization of the polymerizable compound. A radical polymerization initiator or a cationic polymerization initiator can be used, and among these, it is preferable to use a radical polymerization initiator. By using the radical polymerization initiator, there is no inhibition of polymerization due to humidity as in the case of cationic polymerization, so that an advantageous effect that the printing environment is not selected can be obtained. Further, the radical polymerization initiator has oxygen inhibition, and the reactivity changes depending on dissolved oxygen in the ink.
In addition, although it does not specifically limit as a cationic polymerization initiator, For example, the chemical amplification type photoresist and the compound utilized for photocationic polymerization are used (Organic Electronics Materials Research Group, "Organic material for imaging", Shin Publishing (1993), pages 187 to 192, Technical Information Association, “Photocuring Technology”, photoacid generator introduced in 2001). As examples of compounds suitable for this embodiment, first, B (C6F5) 4-, PF6-, AsF6-, SbF6-, CF3SO3- salts of aromatic onium compounds such as diazonium, ammonium, iodonium, sulfonium, etc. Can do. Those having a borate compound as a counter anion are preferred because of their high acid generation ability. Moreover, the sulfonated substance which generate | occur | produces a sulfonic acid, the halide which photogenerates a hydrogen halide, and an iron allene complex are also mentioned suitably. Examples of commercially available cationic polymerization initiators include UV1-6992 (triphenylsulfonium salt, manufactured by The Dow Chemical Company).

  Examples of the radical polymerization initiator include aromatic ketones, acylphosphine compounds, aromatic onium salt compounds, organic peroxides, thio compounds, hexaarylbiimidazole compounds, ketoxime ester compounds, borate compounds, and azinium compounds. , Metallocene compounds, active ester compounds, compounds having a carbon halogen bond, and alkylamine compounds.

  Specific examples of the radical polymerization initiator include acetophenone, acetophenone benzyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, Carbazole, 3-methylacetophenone, 4-chlorobenzophenone, 4,4′-dimethoxybenzophenone, 4,4′-diaminobenzophenone, Michler's ketone, benzoin propyl ether, benzoin ethyl ether, benzyldimethyl ketal, 1- (4-isopropylphenyl) 2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanthone, diethylthio Xanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, bis (2,4,6-trimethylbenzoyl) -phenyl Examples include phosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 2,4-diethylthioxanthone and bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide. It is done.

  Examples of commercially available radical polymerization initiators include IRGACURE 651 (2,2-dimethoxy-1,2-diphenylethane-1-one), IRGACURE 184 (1-hydroxy-cyclohexyl-phenyl-ketone), DAROCUR 1173 ( 2-hydroxy-2-methyl-1-phenyl-propan-1-one), IRGACURE 2959 (1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1 -One), IRGACURE 127 (2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one}, IRGACURE 907 ( 2-Methyl-1- (4-methylthiophenyl) -2-morpholine Nopropan-1-one), IRGACURE 369 (2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1), IRGACURE 379 (2- (dimethylamino) -2-[(4- Methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone), DAROCUR TPO (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide), IRGACURE 819 (bis (2, 4,6-trimethylbenzoyl) -phenylphosphine oxide), IRGACURE 784 (bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole-1-) Yl) -phenyl) titanium), IRGACURE OXE 01 ( 1.2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)]), IRGACURE OXE 02 (ethanone, 1- [9-ethyl-6- (2-methylbenzoyl)- 9H-carbazol-3-yl]-, 1- (O-acetyloxime)), IRGACURE 754 (oxyphenylacetic acid, 2- [2-oxo-2-phenylacetoxyethoxy] ethyl ester and oxyphenylacetic acid, 2- ( 2-hydroxyethoxy) ethyl ester mixture (above, manufactured by Ciba Japan K.K.), KAYACURE DETX-S (2,4-diethylthioxanthone) (Nippon Kayaku Co. , Ltd.), Lucirin TPO, LR8883, LR8970 (above BASF), and Ubekrill 36 (manufactured by UCB), and the like.

  The said photoinitiator may be used individually by 1 type, and may be used in combination of 2 or more type.

(Color material)
The ink composition in the present embodiment may further include a color material. The color material is at least one of a pigment and a dye. Among these, the ink (ink jet recording ink) is an example of a liquid because the effect of applying the ink jet recording method characterized by performing ultrasonic deaeration while stirring and the ink jet recording apparatus used for the method is very large. ) Is preferably a liquid composition containing a pigment, more preferably a liquid composition containing a metal oxide, and even more preferably a pigment-based white ink.

(1. Pigment)
In this embodiment, the light resistance of the ink composition can be improved by using a pigment as the color material. As the pigment, both inorganic pigments and organic pigments can be used.

  As the inorganic pigment, carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black and channel black, iron oxide, and titanium oxide can be used. Among these, as described above, when the pigment-based ink is a white ink, it is preferable to use titanium oxide from the viewpoint of maintaining good whiteness.

  Organic pigments include insoluble azo pigments, condensed azo pigments, azo lakes and chelate azo pigments, phthalocyanine pigments, perylene and perinone pigments, anthraquinone pigments, quinacridone pigments, dioxane pigments, thioindigo pigments, isoindolinone pigments, and quinophthalone pigments. Polycyclic pigments, dye chelates (for example, basic dye chelates, acid dye chelates, etc.), dye rakes (basic dye rakes, acid dye rakes), nitro pigments, nitroso pigments, aniline black, daytime A photofluorescent pigment is mentioned.

  The said pigment may be used individually by 1 type, and may use 2 or more types together. Further, any pigment not described in the color index can be used as long as it is insoluble in water.

(2. Dye)
In the present embodiment, a dye can be used as the color material. The dye is not particularly limited, and acid dyes, direct dyes, reactive dyes, and basic dyes can be used. Examples of the dye include C.I. I. Acid Yellow 17, 23, 42, 44, 79, 142, C.I. I. Acid Red 52, 80, 82, 249, 254, 289, C.I. I. Acid Blue 9, 45, 249, C.I. I. Acid Black 1, 2, 24, 94, C.I. I. Food Black 1, 2, C.I. I. Direct Yellow 1, 12, 24, 33, 50, 55, 58, 86, 132, 142, 144, 173, C.I. I. Direct Red 1, 4, 9, 80, 81, 225, 227, C.I. I. Direct Blue 1, 2, 15, 71, 86, 87, 98, 165, 199, 202, C.I. I. Directed Black 19, 38, 51, 71, 154, 168, 171, 195, C.I. I. Reactive Red 14, 32, 55, 79, 249, C.I. I. Reactive black 3, 4, and 35 are mentioned.

  The ink composition can also be applied to clear ink that does not contain a color material. That is, even in clear ink that does not contain a pigment, excellent printing stability can be achieved by a system having an ultrasonic deaeration process that performs ultrasonic deaeration. In addition to this, the deaeration process can be used more effectively by providing a stirring mechanism. In this case, the deaeration process can obtain the effectiveness more remarkably in the ink having a high viscosity.

  Further, the pigment can be used by being dispersed in a dispersant or a surfactant described later.

(Other ingredients)
The ink composition in the present embodiment may contain components other than the components listed above. Although it does not specifically limit as the said component, For example, a dispersing agent is mentioned.

  Although it does not specifically limit as said dispersing agent, For example, the dispersing agent currently used for preparing pigment dispersion liquids, such as a polymer dispersing agent, Ajimoto fine techno Co., Ltd. Ajispar series, Abyssia Co., Ltd. Examples include Solspers series manufactured by BYK Chemie, Dispersic series manufactured by BYK Chemie, and Disparon series manufactured by Enomoto Kasei Co., Ltd. The polymer dispersant is not particularly limited, and examples thereof include polyoxyalkylene polyalkylene polyamines, vinyl polymers and copolymers, acrylic polymers and copolymers, polyesters, polyamides, polyimides, polyurethanes, amino polymers, silicon-containing polymers, and the like. The thing which has 1 or more types as a main component among a sulfur polymer, a fluorine-containing polymer, an epoxy resin, etc. is mentioned.

  Although it does not specifically limit as said surfactant, For example, polyester modified silicone and polyether modified silicone can be used as a silicone type surfactant, Polyether modified polydimethylsiloxane or polyester modified polydimethylsiloxane is used. It is particularly preferred. Specific examples include BYK-347, BYK-348, BYK-UV3500, 3510, 3530, and 3570 (manufactured by BYK Japan KK).

  Furthermore, the ink composition comprises a polymerization accelerator, slip agent, penetration enhancer, wetting agent (humectant), fixing agent, antifungal agent, preservative, surfactant, antioxidant, polymerization inhibitor, UV absorber. , Chelating agents, pH adjusters, and thickeners.

Hereinafter, the effect by embodiment is described. According to the present embodiment, the following effects can be obtained.
(1) A circulation path is formed by the circulation tank 42, the supply pipe 62, the switching valve 43, and the circulation pipe 64, and the functional liquid 40 circulates through the circulation path. Thereby, compared with the case where the functional liquid 40 is stored in a stationary state, it is possible to suppress the functional liquid 40 from being easily solidified by being maintained in a stationary state.

  (2) The functional liquid supply unit 4 includes a deaeration unit 71. By the degassing unit 71, the functional liquid 40 supplied to the droplet discharge head 20 can be degassed to reduce the dissolved gas concentration.

  (3) The deaeration unit 71 is a circulation constituted by a circulation tank 42, a supply pipe 62, a switching valve 43, and a circulation pipe 64 in a supply path through which the functional liquid 40 is supplied to the droplet discharge head 20. It is arranged downstream of the path. The functional liquid 40 is deaerated when passing through the deaeration unit 71. For this reason, the functional liquid 40 circulating in the circulation path upstream of the degassing unit 71 has a higher dissolved gas concentration than the functional liquid 40 in the droplet discharge head 20 located downstream of the degassing unit 71. The functional liquid 40 circulating in the circulation path is held inside the functional liquid supply section 4 in a circulating state, and compared to the functional liquid 40 moved downstream in the circulation path, the functional liquid supply section 4. There is a high possibility that the time existing in the inside will be long. When the functional liquid 40 is degassed, for example, the polymerization inhibitor is reduced and the functional liquid 40 is easily solidified. By disposing the deaeration unit 71 downstream of the circulation path, it is possible to suppress the functional liquid 40 that is likely to stay in the functional liquid supply unit 4 from being easily solidified.

  (4) The functional liquid supply unit 4 includes a pressure adjustment valve 77. The pressure of the functional liquid 40 supplied to the droplet discharge head 20 can be adjusted to a constant hydraulic pressure by the pressure adjustment valve 77.

  (5) The deaeration unit 71 is disposed upstream of the pressure adjustment valve 77 in the supply path through which the functional liquid 40 is supplied to the droplet discharge head 20. Thereby, the hydraulic pressure of the functional fluid 40 adjusted by the pressure regulating valve 77 can be substantially prevented from being influenced by the deaeration unit 71.

  (6) The deaeration unit 71 is fixed to the head carriage 22. Accordingly, the deaeration unit 71 is disposed near the droplet discharge head 20. Thereby, the amount of the functional liquid 40 deaerated by the deaeration unit 71 and staying between the liquid droplet ejection head 20 is compared with the configuration in which the distance between the deaeration unit 71 and the liquid droplet ejection head 20 is long. Can be reduced.

  As mentioned above, although preferred embodiment was described referring an accompanying drawing, suitable embodiment is not restricted to the said embodiment. The embodiment can of course be modified in various ways without departing from the scope, and can also be implemented as follows.

  (Modification 1) In the above-described embodiment, the functional liquid supply unit 4 includes the pressure adjustment valve 77. However, a device that adjusts the liquid pressure of the liquid supplied to the discharge head to a constant liquid pressure adjusts the pressure. It is not essential that the device is like the valve 77. For example, by providing a liquid reservoir in the middle of the liquid supply path, and maintaining the water head difference between the liquid level of the liquid supplied to the liquid reservoir and the liquid level of the liquid in the discharge head constant, It may be a device that adjusts the liquid pressure of the liquid material supplied to the head to a constant liquid pressure.

  (Modification 2) In the embodiment, in the example shown in FIG. 4, one deaeration unit 71 is provided for one droplet discharge head 20. However, it is not essential that one discharge head is supplied with the liquid material deaerated by one deaeration means. A configuration in which a liquid material deaerated by one deaeration unit is supplied to a plurality of ejection heads may be employed.

(Modification 3) In the above embodiment, the switching valve 43 corresponding to the connecting portion is fixed to the head carriage 22 and moves together with the head carriage 22 (droplet ejection head 20). It is not essential for the connecting portion to move together with the ejection head. The connecting portion may be fixed to the moving ejection head.
When the connection portion is fixed, the connection portion and the storage tank can be disposed close to each other, so that the first supply path and the circulation flow path can be shortened.

  (Modification 4) In the above embodiment, the droplet discharge device 1 includes one head unit 21. However, it is not essential that the drawing apparatus has one head unit. Any number of head units may be provided in the drawing apparatus. When the drawing apparatus includes a plurality of head units, the type of liquid material to be ejected may be different for each head unit.

  (Modification 5) In the above embodiment, the head unit 21 includes nine droplet discharge heads 20, but it is not essential that the head unit includes nine discharge heads. Any number of ejection heads may be included in the head unit.

  (Modification 6) In the above-described embodiment, the droplet discharge head 20 includes two nozzle rows 24A in which a large number of discharge nozzles 24 are arranged in a substantially straight line. However, how many nozzle rows the discharge head includes. It may be. When the droplet discharge head includes a plurality of nozzle rows, the type of liquid material to be discharged may be different for each nozzle row. When different types of liquid are ejected for each nozzle row, it is necessary to provide deaeration means for each type of liquid.

  (Modification 7) In the above embodiment, the workpiece W 33 is moved in the X-axis direction by moving the workpiece mounting table 33 in the X-axis direction by the X-axis scanning mechanism, and the droplet discharge head 20 is moved by the Y-axis scanning mechanism. By moving the (head unit 21) in the Y-axis direction, the workpiece W and the droplet discharge head 20 are relatively moved in the plane direction. It is not essential to move both the drawing medium and the ejection head in order to move the drawing medium and the ejection head relative to each other. A configuration may be adopted in which either the drawing medium or the ejection head is moved in the plane direction to move the drawing medium and the ejection head relative to each other.

(Modification 8) In the above embodiment, the type of the functional liquid to be ejected by the droplet ejection device 1 is not particularly described, but different types of functional liquids such as different colors may be ejected. Color drawing is also possible by discharging a plurality of types of functional liquids having different colors. The type of functional liquid may be different for each droplet discharge head, or may be different for each head set 20A. Different functional liquids may be ejected from one ejection nozzle to another by using a droplet ejection head that can individually supply functional liquid to each ejection nozzle.
When different types of functional liquids are used, the circulation path may be provided in all of the functional liquid supply paths, or may be provided only in the functional liquid supply path in which it is particularly effective to provide the circulation paths. Examples of the functional liquid in which it is particularly effective to provide a circulation path include those containing a large amount of pigment, such as white ink and metallic ink.

  DESCRIPTION OF SYMBOLS 1 ... Droplet discharge apparatus, 2 ... Head mechanism part, 3 ... Work mechanism part, 4 ... Functional liquid supply part, 6 ... Discharge apparatus control part, 20 ... Droplet discharge head, 20A ... Head group, 21 ... Head unit, DESCRIPTION OF SYMBOLS 22 ... Head carriage, 23 ... Unit plate, 24 ... Discharge nozzle, 24A ... Nozzle row, 25 ... Nozzle substrate, 26 ... Connection needle, 33 ... Workpiece mounting table, 40 ... Functional liquid, 41 ... Functional liquid tank, 42 ... Circulation Tank, 43 ... switching valve, 44 ... valve holding frame, 53 ... liquid supply hole, 58 ... pressure chamber, 59 ... piezoelectric element, 61, 62, 63 ... supply pipe, 64 ... circulation pipe, 66 ... liquid distribution pipe, 67 ... Pipe connection member, 71 ... Deaeration unit, 73,75 ... Pump, 77 ... Pressure adjustment valve, 77a ... Adjustment valve support frame.

Claims (4)

A discharge head for discharging a liquid material containing at least a polymerizable compound and a photopolymerization initiator is provided, the liquid material is discharged from the discharge head toward a drawing medium, and the liquid material is disposed on the drawing medium. A drawing device,
A storage tank for storing the liquid material;
A first supply path that is connected to the storage tank and the connection portion, and is a path through which the liquid material is sent from the storage tank to the connection portion;
A circulation channel that is connected to the storage tank and the connection portion, and is a path through which the liquid material is sent from the connection portion to the storage tank;
A second supply path that is connected to the connection portion and the discharge head, and is a path through which the liquid material is supplied from the connection portion to the discharge head;
Degassing means for degassing the dissolved gas in the liquid,
The deaeration means is disposed in the second supply path,
The drawing device, wherein the connection unit switches a flow path communicating with the first supply path to the circulation flow path or the second supply path.   The drawing apparatus according to claim 1, wherein the liquid material is a radical polymerization type ultraviolet curable ink.   The dissolved gas concentration of the dissolved gas in the liquid material in the first supply channel and the circulation channel is higher than the dissolved gas concentration in the discharge head, according to claim 1 or 2. Drawing device. A pressure adjusting means for adjusting the pressure of the liquid material in the discharge head;
The drawing apparatus according to claim 1, wherein the pressure adjusting unit is disposed between the degassing unit and the discharge head in the second supply path. .

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