JP2024136675A - Liquid ejection head and liquid ejection apparatus - Google Patents

Abstract

To solve the problem in that the monomer of an ultraviolet curable ink passes through a silicone adhesive for connecting a flow passage of a liquid ejection head, which has a low gas barrier property, and leaks outside the flow passage of the liquid ejection head, thus leading to a possibility that the liquid ejection head may be broken.SOLUTION: A liquid ejection head includes: a nozzle for ejecting an acrylic ultraviolet curable ink; and an introduction port 44a which communicates with the nozzle and through which the ultraviolet curable ink flows. A first adhesive A which is an acrylic ultraviolet curable adhesive capable of absorbing a monomer contained in the ultraviolet curable ink is provided. The first adhesive A is caused to adhere only to a case member 40 which is one component composing the liquid ejection head.SELECTED DRAWING: Figure 9

Description

The present invention relates to a liquid ejection head and a liquid ejection device that ejects liquid.

Liquid ejection devices, such as inkjet printers, generally have a liquid ejection head that ejects liquid such as ink. For example, Patent Document 1 discloses a liquid ejection head that ejects ultraviolet-curable ink (hereinafter also referred to as UV ink) by connecting flow path members that define a part of the liquid flow path to each other by bonding them together with a silicone-based adhesive for connecting the flow paths.

JP 2020-25894 A

In conventional liquid jet heads, there was a risk that UV ink monomers could leak out of the flow paths of the liquid jet head through parts of the liquid jet head with poor gas barrier properties, such as the silicone adhesive used to connect the flow paths, causing the liquid jet head to break down.

The aspect of the present invention that solves the above problem is a liquid jet head that includes a nozzle for ejecting acrylic ultraviolet curable ink and a flow path that communicates with the nozzle and through which the ultraviolet curable ink flows, and is characterized in that the liquid jet head includes a first adhesive that is an acrylic ultraviolet curable adhesive capable of absorbing a monomer contained in the ultraviolet curable ink, and the first adhesive is bonded to only one component that constitutes the liquid jet head.

Another aspect of the present invention is a liquid ejection device comprising the above-mentioned liquid ejection head and a liquid storage section that stores the ultraviolet-curable ink to be supplied to the liquid ejection head.

1 is a diagram illustrating a schematic configuration of a liquid ejecting apparatus according to a first embodiment. FIG. 2 is an exploded perspective view of the liquid jet head. 3 is a cross-sectional view taken along line AA in FIG. 2. FIG. 4 is an enlarged cross-sectional view of a main part of FIG. 3 . FIG. 2 is an exploded perspective view of the head chip. FIG. 2 is a plan view of a head chip. 7 is a cross-sectional view taken along line BB in FIG. 6. 4 is a plan view of a second relay flow path member and a head chip. FIG. FIG. 2 is a plan view of a head chip. 9 is a cross-sectional view taken along line CC of FIG. 8. 9 is a cross-sectional view taken along line D-D in FIG. 8. FIG. 12 is an enlarged cross-sectional view of a portion of FIG. 11 .

The present invention will be described in detail below based on an embodiment. However, the following description shows only one aspect of the present invention and can be modified as desired within the scope of the present invention.

The present invention will be described in detail below based on an embodiment. However, the following description shows one aspect of the present invention, and can be modified as desired within the scope of the present invention. In each figure, the same reference numerals indicate the same members, and the description is omitted as appropriate. In each figure, X, Y, and Z represent three spatial axes that are mutually perpendicular. In this specification, the directions along these axes are defined as the X direction, Y direction, and Z direction. The direction indicated by the arrow in each figure is defined as the positive (+) direction, and the direction opposite the arrow is defined as the negative (-) direction. In addition, the directions of the three spatial axes that are not limited to the positive and negative directions are defined as the X-axis direction, Y-axis direction, and Z-axis direction.

(Embodiment 1)
1 is a diagram showing a schematic configuration of a liquid ejection device 1 of the present invention. The liquid ejection device 1 is an inkjet recording device that ejects and impacts ink as ink droplets onto a medium S such as printing paper, and prints an image or the like by an arrangement of dots formed on the medium S. Note that the medium S can be made of any material, such as recording paper, resin film, cloth, etc.

The liquid ejection device 1 comprises a liquid ejection head 2, a liquid storage section 3, a control unit 4 which serves as a control section, a transport mechanism 5 which feeds the medium S, and a movement mechanism 6.

The liquid ejection head 2 ejects ink supplied from the liquid storage section 3 from multiple nozzles onto the medium S. The detailed configuration of the liquid ejection head 2 will be described later.

The liquid storage section 3 stores the ink to be ejected from the liquid ejection head 2. Examples of the liquid storage section 3 include a cartridge that can be attached to and detached from the liquid ejection device 1, a bag-shaped ink pack made of a flexible film, and an ink tank that can be refilled with ink. Although not specifically shown, the liquid storage section 3 stores multiple types of ink with different colors, ingredients, etc., individually.

The ink ejected from the liquid ejection head 2 is an acrylic UV-curable ink. An acrylic UV-curable ink is an ink that contains color materials including pigments, a photopolymerization initiator, a monomer (a monomer obtained by reacting acrylate/acrylic acid), a polymerization inhibitor, and a solvent for adjusting hardness and viscosity. The UV-curable ink may also contain various additives such as a sensitizer for promoting the initiation reaction of the photopolymerization initiator, a heat stabilizer, an antioxidant, a preservative, an antifoaming agent, a penetrating agent, a resin binder, a resin emulsion, a reduction inhibitor, a leveling agent, a pH adjuster, a pigment derivative, a polymerization inhibitor, an UV absorber, and a light stabilizer. The ink mentioned hereafter refers to an acrylic UV-curable ink.

In this embodiment, the liquid storage unit 3 has a main tank 3a and a sub tank 3b for each type of ink. The sub tank 3b is connected to the liquid ejection head 2, and ink consumed by ejecting ink droplets from the liquid ejection head 2 is replenished from the main tank 3a to the sub tank 3b. Of course, the liquid storage unit 3 may be composed of only the main tank 3a.

The liquid ejection device 1 has a circulation mechanism 7 for circulating ink between the liquid ejection head 2 and the subtank 3b.

The circulation mechanism 7 includes a supply pump 7a, a circulation pump 7b, a sub-tank 3b, a recovery tube 7c, and a supply tube 7d.

The supply pump 7a is a pump that supplies the ink stored in the main tank 3a to the sub tank 3b. The circulation pump 7b is a pump that supplies, i.e., pressurizes, the ink stored in the sub tank 3b to the liquid ejection head 2.

The recovery tube 7c has a flow path for ink that is not used for printing by the liquid jet head 2 and is recovered in the sub tank 3b. The supply tube 7d has a flow path for ink that is supplied from the sub tank 3b to the liquid jet head 2.

The subtank 3b is a container that temporarily stores the ink supplied from the liquid storage section 3. The subtank 3b also temporarily stores the ink that is not used for printing by the liquid ejection head 2 and is collected via the collection tube 7c.

In this type of circulation mechanism 7, the circulation pump 7b supplies ink from the subtank 3b via the supply tube 7d to the liquid jet head 2, and recovers ink not used in the liquid jet head 2 to the subtank 3b via the recovery tube 7c. This causes ink to circulate between the liquid jet head 2 and the subtank 3b. Furthermore, when the amount of ink stored in the subtank 3b falls below a certain amount, the supply pump 7a supplies ink from the main tank 3a to the subtank 3b.

The control unit 4 includes, for example, a control device such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array), and a storage device such as a semiconductor memory. The control unit 4 comprehensively controls each element of the liquid ejection device 1, i.e., the liquid ejection head 2, the transport mechanism 5, the movement mechanism 6, etc., by the control device executing a program stored in the storage device.

The transport mechanism 5 transports the medium S in the X-axis direction and has a transport roller 5a. That is, the transport mechanism 5 transports the medium S in the X-axis direction by rotating the transport roller 5a. Note that the transport mechanism 5 that transports the medium S is not limited to one that includes a transport roller 5a, and may transport the medium S by, for example, a belt or a drum.

The moving mechanism 6 includes a conveying body 6a and a conveying belt 6b. The conveying body 6a is a generally box-shaped structure, a so-called carriage, that houses the liquid ejection head 2, and is fixed to the conveying belt 6b. The conveying belt 6b is an endless belt that is installed along the Y-axis direction. The conveying belt 6b rotates when driven by a conveying motor (not shown). The control unit 4 controls the drive of the conveying motor to rotate the conveying belt 6b, and the liquid ejection head 2 moves back and forth together with the conveying body 6a in the Y-axis direction along a guide rail (not shown). The sub-tank 3b of the liquid storage unit 3 can also be mounted on the conveying body 6a together with the liquid ejection head 2.

Under the control of the control unit 4, the liquid jet head 2 performs an ejection operation in which ink supplied from the liquid storage section 3 is ejected as ink droplets from each of the multiple nozzles 21 (see FIG. 7) in the +Z direction. This ejection operation of ink droplets by the liquid jet head 2 is performed in parallel with the transport of the medium S by the transport mechanism 5 and the reciprocating movement of the liquid jet head 2 by the movement mechanism 6, thereby forming an image in ink on the surface of the medium S, a so-called printing operation.

The liquid jet head 2 will be described using Figures 2 to 4. Figure 2 is an exploded perspective view of the liquid jet head 2. Figure 3 is a cross-sectional view taken along line A-A in Figure 2. Figure 4 is an enlarged cross-sectional view of the main parts of Figure 3. Note that each direction of the liquid jet head 2 will be described based on the directions when it is mounted on the liquid jet device 1, that is, the X-axis direction, Y-axis direction, and Z-axis direction. Of course, the position of the liquid jet head 2 within the liquid jet device 1 is not limited to that shown below.

The liquid jet head 2 includes a head chip 8, a relay flow path member 200 having a supply flow path 400 and a discharge flow path 410, a relay substrate 210, and a cover head 220.

The relay flow path member 200 has a supply flow path 400 that supplies ink supplied from the liquid storage section 3 to the head chip 8, and a discharge flow path 410 that returns ink that has not been ejected from the nozzles of the head chip 8 to the liquid storage section 3.

The relay flow path member 200 includes a first relay flow path member 201, a second relay flow path member 202, and a sealing member 203. The first relay flow path member 201, the sealing member 203, and the second relay flow path member 202 are stacked in this order in the +Z direction.

The first relay flow path member 201 is a member in which a first supply flow path 401 and a first discharge flow path 411 are provided. The first relay flow path member 201 of this embodiment is configured by stacking three members 201a, 201b, and 201c in the Z-axis direction. The first relay flow path member 201 has a supply side flow path connection portion 204a and a discharge side flow path connection portion 204b. When the supply side flow path connection portion 204a and the discharge side flow path connection portion 204b are not distinguished from each other, they are referred to as a flow path connection portion 204. In this embodiment, the flow path connection portion 204 has a cylindrical shape that protrudes in the -Z direction on the -Z direction surface of the first relay flow path member 201. A supply tube 7d is connected to the supply side flow path connection portion 204a, and a recovery tube 7c is connected to the discharge side flow path connection portion 204b. A first supply flow path 401 is provided inside the supply side flow path connection part 204a, and a first discharge flow path 411 is provided inside the discharge side flow path connection part 204b.

The first supply flow path 401 is composed of a flow path extending in the Z-axis direction, a flow path extending along the lamination interface of the laminated members, etc. A filter chamber 401a having an inner diameter wider than other regions is provided in the middle of the first supply flow path 401, and a filter 401b that captures foreign matter such as dust and air bubbles contained in the ink is provided in the filter chamber 401a. The first discharge flow path 411 is composed of a flow path extending in the Z-axis direction like the first supply flow path 401, a flow path extending along the lamination interface of the laminated members, etc. In this embodiment, the first discharge flow path 411 does not have a filter chamber 401a or a filter 401b provided in the middle, but of course it may be provided. In addition, the first supply flow path 401 may be branched into two or more downstream of the filter 401b, for example.

The seal member 203 is formed using a material that is resistant to liquids such as ink used in the liquid jet head 2 and is elastically deformable, such as rubber or elastomer. The seal member 203 is provided with a supply side connection flow path 403 and a discharge side connection flow path 413 that penetrate in the Z-axis direction.

The second relay flow path member 202 has a second supply flow path 402 and a second discharge flow path 412 that extend in the Z-axis direction. The first supply flow path 401 and the second supply flow path 402 are liquid-tightly connected via a supply side connection flow path 403 of the seal member 203. Similarly, the first discharge flow path 411 and the second discharge flow path 412 are liquid-tightly connected via a discharge side connection flow path 413 of the seal member 203. In addition, a protrusion 207 having the second supply flow path 402 or the second discharge flow path 412 provided therein is provided on the surface of the second relay flow path member 202 facing the -Z direction so as to protrude in the -Z direction.

In this way, the relay flow path member 200 includes a supply flow path 400 having a first supply flow path 401, a supply side connection flow path 403, and a second supply flow path 402, and a discharge flow path 410 having a first discharge flow path 411, a discharge side connection flow path 413, and a second discharge flow path 412. In this embodiment, one first relay flow path member 201 includes four supply flow paths 400 and four discharge flow paths 410.

A head chip 8 is held on the surface of the second relay flow path member 202 facing the +Z direction. In the liquid jet head 2 of this embodiment, multiple head chips 8 are held, and in this embodiment, two head chips are held as an example. Of course, the number of head chips 8 held by the liquid jet head 2 is not particularly limited to this, and may be one, or two or more. Also, in this embodiment, the two head chips 8 are arranged side by side in the Y axis direction so that they are at the same position in the X axis direction. Of course, the arrangement of the multiple head chips 8 is not particularly limited to this, and may be arranged in a staggered pattern along the X axis direction, for example.

The surface of the second relay flow path member 202 facing the +Z direction is provided with a holding space 208 (see FIG. 7) capable of accommodating two head chips 8. In this embodiment, the holding space 208 opens to the +Z direction side and has a holding surface 209 facing the +Z direction side. The second supply flow path 402 and the second discharge flow path 412 open to the holding surface 209. The second supply flow path 402 is connected to each inlet 44a of the head chip 8, and the second discharge flow path 412 is connected to the outlet 44b of the head chip 8.

The second relay flow path member 202 is provided with third wiring insertion holes 205 for inserting the wiring members 110 of each head chip 8. In this embodiment, two third wiring insertion holes 205 are provided for each of the two head chips 8. The wiring members 110 of the head chip 8 are led out to the surface side of the second relay flow path member 202 facing the -Z direction through the third wiring insertion holes 205.

In the Z-axis direction, a relay board 210 to which the wiring members 110 of the multiple head chips 8 are commonly connected is provided between the second relay flow path member 202 and the seal member 203. The relay board 210 is made of a hard rigid board with no flexibility, and is equipped with wiring and electronic components (not shown). The relay board 210 is provided with a connector 211 to which external wiring is connected. Printing signals for controlling the head chips 8 are input from external wiring (not shown) to the relay board 210 via the connector 211, and are supplied to each head chip 8 from the relay board 210. In addition, an external wiring opening 206 for inserting external wiring connected to the connector 211 is provided on the side wall facing the connector 211 of the relay flow path member 200. The external wiring is connected to the connector 211 of the relay board 210 provided inside the relay flow path member 200 through the external wiring opening 206.

The relay substrate 210 is provided with a fourth wiring insertion hole 212 for leading out the wiring member 110 of the head chip 8 to the surface side facing the -Z direction. A total of two fourth wiring insertion holes 212 are provided, one for each head chip 8.

The relay substrate 210 is provided with a protrusion insertion hole 213 that penetrates in the Z-axis direction. The protrusion 207 of the second relay flow path member 202 is inserted through the protrusion insertion hole 213 into the -Z direction side of the relay substrate 210 and connected to the supply side connection flow path 403 or the discharge side connection flow path 413.

A cover head 220 is fixed to the surface of the relay flow path member 200 facing the +Z direction. In this embodiment, the cover head 220 is large enough to cover two head chips 8. The cover head 220 is provided with an exposure opening 221 that exposes the nozzle 21 of the head chip 8 in the +Z direction, independently for each head chip 8. Ink is ejected in the +Z direction from the nozzle 21 exposed from the exposure opening 221. Of course, the exposure opening 221 may be provided in common to multiple head chips 8.

Here, the head chip 8 mounted on the liquid jet head 2 will be further described with reference to Figs. 5 to 7. Fig. 5 is an exploded perspective view of the head chip 8 according to one embodiment of the present invention. Fig. 6 is a plan view of the head chip 8. Fig. 7 is a cross-sectional view of the head chip 8, relay flow path member 200, and cover head 220 taken along line B-B in Fig. 6. Note that the directions of the head chip 8 will be described based on the directions when it is mounted on the liquid jet head 2, i.e., the X-axis direction, the Y-axis direction, and the Z-axis direction.

The head chip 8 includes a flow path forming substrate 10. The flow path forming substrate 10 is made of, for example, a silicon substrate, a glass substrate, an SOI substrate, or any of various ceramic substrates.

The flow path forming substrate 10 has a plurality of pressure chambers 12 arranged in a line along the X-axis direction. The pressure chambers 12 are arranged in a straight line along the X-axis direction so that they are at the same position in the Y-axis direction. Two pressure chambers 12 adjacent to each other in the X-axis direction are separated by a partition. In this embodiment, two pressure chamber rows are provided in the Y-axis direction, in which the pressure chambers 12 are arranged in parallel along the X-axis direction. Of course, the arrangement of the pressure chambers 12 is not particularly limited to this, and for example, the pressure chambers 12 may be arranged in a staggered pattern along the X-axis direction.

A communication plate 15 and a nozzle plate 20 are stacked in sequence on the surface of the flow path forming substrate 10 facing the +Z direction.

The communication plate 15 is made of a plate-like member bonded to the surface of the flow passage forming substrate 10 facing the +Z direction. The communication plate 15 is provided with a nozzle communication passage 16 that connects the pressure chamber 12 and the nozzle 21.

The communication plate 15 is provided with a first manifold portion 17 and a second manifold portion 18 which constitute a part of a manifold 100 which serves as a common liquid chamber to which the multiple pressure chambers 12 are commonly connected. The first manifold portion 17 is provided so as to penetrate the communication plate 15 in the Z-axis direction. The second manifold portion 18 is provided so as to open on the surface facing the +Z direction, without penetrating the communication plate 15 in the Z-axis direction.

Furthermore, the communication plate 15 is provided with a supply communication passage 19 that is independent of each pressure chamber 12 and communicates with one end of the pressure chamber 12 in the Y-axis direction. The supply communication passage 19 communicates between the second manifold portion 18 and the pressure chamber 12, and supplies ink in the manifold 100 to the pressure chamber 12.

Such a communication plate 15 can be a silicon substrate, a glass substrate, an SOI substrate, various ceramic substrates, a metal substrate such as a stainless steel substrate, or the like. It is preferable that the communication plate 15 is made of a material having approximately the same thermal expansion coefficient as the flow path forming substrate 10. By using materials having approximately the same thermal expansion coefficient for the flow path forming substrate 10 and the communication plate 15 in this way, it is possible to reduce the occurrence of warping due to heat caused by differences in thermal expansion coefficients.

The nozzle plate 20 is joined to the side of the communication plate 15 opposite the flow path forming substrate 10, i.e., the surface facing the +Z direction.

The nozzle plate 20 is formed with nozzles 21 that communicate with each pressure chamber 12 via the nozzle communication passage 16. The nozzles 21 are arranged in a line along the X-axis direction. In addition, two nozzle rows in which the nozzles 21 are arranged in parallel along the X-axis direction are provided at a distance in the Y-axis direction. The two nozzle rows arranged in parallel in the Y-axis direction may be arranged such that the nozzles 21 constituting each row are shifted by half a pitch from each other in the X-axis direction. As such a nozzle plate 20, a silicon substrate, a glass substrate, an SOI substrate, various ceramic substrates, a metal substrate such as a stainless steel substrate, an organic material such as a polyimide resin, etc. can be used. It is preferable that the nozzle plate 20 is made of a material having a thermal expansion coefficient approximately equal to that of the communication plate 15. By using materials having a thermal expansion coefficient approximately equal to that of the communication plate 15 in this way, it is possible to reduce the occurrence of warping due to heat caused by the difference in thermal expansion coefficient.

A vibration plate 50 and a piezoelectric element 300 are layered in sequence on the surface of the flow path forming substrate 10 facing the -Z direction.

In this embodiment, the vibration plate 50 has an elastic film 51 made of silicon oxide provided on the flow path forming substrate 10 side, and an insulating film 52 made of zirconium oxide provided on the surface of the elastic film 51 facing the -Z direction. The vibration plate 50 may be composed of only the elastic film 51, or may be composed of only the insulating film 52, or may have another film in addition to the elastic film 51 and the insulating film 52.

The piezoelectric element 300 includes a first electrode 60, a piezoelectric layer 70, and a second electrode 80, which are sequentially stacked on the vibration plate 50 toward the -Z direction. The piezoelectric element 300 is a driving element that generates a pressure change in the ink in the pressure chamber 12. Such a piezoelectric element 300 is also called a piezoelectric actuator, and refers to a portion including the first electrode 60, the piezoelectric layer 70, and the second electrode 80. In addition, a portion where a piezoelectric strain occurs in the piezoelectric layer 70 when a voltage is applied between the first electrode 60 and the second electrode 80 is called an active portion 310. In contrast, a portion where no piezoelectric strain occurs in the piezoelectric layer 70 is called an inactive portion. In other words, the active portion 310 refers to a portion where the piezoelectric layer 70 is sandwiched between the first electrode 60 and the second electrode 80. In this embodiment, an active portion 310 is formed for each pressure chamber 12. In other words, a plurality of active portions 310 are formed in the piezoelectric element 300. In general, one of the electrodes of the active parts 310 is configured as an individual electrode independent for each active part 310, and the other electrode is configured as a common electrode common to the multiple active parts 310. In this embodiment, the first electrode 60 constitutes the individual electrode, and the second electrode 80 constitutes the common electrode. Of course, the first electrode 60 may constitute the common electrode, and the second electrode 80 may constitute the individual electrode.

The first electrode 60 is separated for each pressure chamber 12 to form an independent individual electrode for each active section 310. The first electrode 60 is formed with a width narrower than the width of the pressure chamber 12 in the +X direction. That is, in the +X direction, the end of the first electrode 60 is located inside the area facing the pressure chamber 12. Also, as shown in FIG. 7, the end of the first electrode 60 on the nozzle 21 side in the Y axis direction is located outside the pressure chamber 12. A lead electrode 90, which is a lead wiring, is connected to the end of the first electrode 60 located outside the pressure chamber 12 in the Y axis direction.

The piezoelectric layer 70 has a predetermined width in the +Y direction and is provided continuously in the +X direction. The width of the piezoelectric layer 70 in the Y-axis direction is longer than the length of the pressure chamber 12 in the Y-axis direction. Therefore, on both sides of the pressure chamber 12 in the +Y direction and the -Y direction, the piezoelectric layer 70 extends to the outside of the area facing the pressure chamber 12. The end of the piezoelectric layer 70 on the opposite side to the nozzle 21 in the Y-axis direction is located outside the end of the first electrode 60. In other words, the end of the first electrode 60 on the opposite side to the nozzle 21 is covered by the piezoelectric layer 70. In addition, the end of the piezoelectric layer 70 on the nozzle 21 side is located inside the end of the first electrode 60, and the end of the first electrode 60 on the nozzle 21 side is not covered by the piezoelectric layer 70. The piezoelectric layer 70 is made of a piezoelectric material made of a complex oxide with a perovskite structure represented by the general formula ABO3.

As shown in FIG. 7, the second electrode 80 is provided continuously on the -Z direction side of the piezoelectric layer 70, which is the opposite side to the first electrode 60, and constitutes a common electrode shared by multiple active sections 310. The second electrode 80 is provided continuously over the X-axis direction so that the Y-axis direction has a predetermined width.

A lead electrode 90, which is an extraction wiring, is drawn out from the first electrode 60. A wiring member 110 made of a flexible substrate having flexibility is connected to the end of the lead electrode 90 opposite the end connected to the piezoelectric element 300. The wiring member 110 is equipped with a drive signal selection circuit 111 having a plurality of switching elements that select whether or not to drive each of the active parts 310. In other words, the wiring member 110 is made of COF. Note that the wiring member 110 does not need to be provided with the drive signal selection circuit 111. In other words, the wiring member 110 may be an FFC, an FPC, or the like.

The piezoelectric element 300 including the first electrode 60, the piezoelectric layer 70, and the second electrode 80 has each layer formed by film formation and lithography. Therefore, the piezoelectric element 300 of this embodiment is a piezoelectric thin film including the piezoelectric layer 70, which is a "thin film piezoelectric." Here, a piezoelectric thin film including a thin film piezoelectric refers to a film having a thickness of less than 10 μm in the Z-axis direction, which is the stacking direction including the first electrode 60, the piezoelectric layer 70, and the second electrode 80. Note that the piezoelectric thin film is preferably 3 μm or less in order to arrange multiple nozzles 21 at high density.

A protective substrate 30 having approximately the same size as the flow path forming substrate 10 is bonded to the surface of the flow path forming substrate 10 facing the -Z direction. The protective substrate 30 has a holding portion 31 which is a space that protects the piezoelectric elements 300. The holding portions 31 are provided independently for each row of the piezoelectric elements 300 arranged in the X-axis direction, and two holding portions 31 are formed side by side in the Y-axis direction. In addition, the protective substrate 30 is provided with a first wiring insertion hole 32 penetrating in the Z-axis direction between the two holding portions 31 arranged side by side in the Y-axis direction. The end of the lead electrode 90 drawn from the electrode of the piezoelectric element 300 is extended so as to be exposed in the first wiring insertion hole 32, and the lead electrode 90 and the wiring member 110 are electrically connected in the first wiring insertion hole 32.

Such a protective substrate 30 may be, for example, a silicon substrate, a glass substrate, an SOI substrate, or various ceramic substrates, just like the flow path forming substrate 10. It is preferable that the protective substrate 30 is made of a material having approximately the same thermal expansion coefficient as the flow path forming substrate 10. By using materials having approximately the same thermal expansion coefficient for the flow path forming substrate 10 and the protective substrate 30 in this way, it is possible to reduce the occurrence of warping due to heat caused by differences in thermal expansion coefficients.

A case member 40 is fixed onto the protective substrate 30, and together with the flow path forming substrate 10 defines a manifold 100 that communicates with the multiple pressure chambers 12. The case member 40 has approximately the same shape as the above-mentioned communication plate 15 in a plan view, and is joined to the protective substrate 30 and also to the above-mentioned communication plate 15.

Such a case member 40 has an accommodating recess 41 on the protective substrate 30 side, deep enough to accommodate the flow path forming substrate 10 and the protective substrate 30. This accommodating recess 41 has an opening area larger than the surface of the protective substrate 30 that is joined to the flow path forming substrate 10. Then, with the flow path forming substrate 10 and the protective substrate 30 accommodated in the accommodating recess 41, the opening surface of the accommodating recess 41 on the nozzle plate 20 side is sealed by a communication plate 15.

The case member 40 is provided with a third manifold portion 42 that communicates with the first manifold portion 17 of the communication plate 15. The first manifold portion 17 and the second manifold portion 18 provided on the communication plate 15 and the third manifold portion 42 provided on the case member 40 constitute the manifold 100 of this embodiment. The manifolds 100 are provided for each row of pressure chambers 12, that is, two in total. Each manifold 100 is provided continuously over the X-axis direction in which the pressure chambers 12 are arranged side by side, and the supply communication passages 19 that communicate each pressure chamber 12 and the manifold 100 are arranged side by side in the X-axis direction. The case member 40 is also provided with an inlet 44a that communicates with the manifold 100 and supplies ink to each manifold 100. In addition, the case member 40 is provided with a second wiring insertion hole 43 through which the wiring member 110 is inserted and communicates with the first wiring insertion hole 32 of the protective substrate 30, and the wiring member 110 is led out through the second wiring insertion hole 43 to the surface side of the liquid ejection head 2 facing the -Z direction.

A compliance substrate 45 is provided on the +Z direction side surface of the communication plate 15 where the first manifold portion 17 and the second manifold portion 18 open, via an epoxy adhesive 151 (see FIG. 10). This compliance substrate 45 seals the openings on the ejection surface 20a side of the first manifold portion 17 and the second manifold portion 18. In this embodiment, such a compliance substrate 45 includes a sealing film 46 made of a flexible thin film, and a fixed substrate 47 made of a hard material such as metal. The region of the fixed substrate 47 facing the manifold 100 is an opening 48 that is completely removed in the thickness direction, so one side of the manifold 100 is a compliance portion 49 that is a flexible portion sealed only by the flexible sealing film 46.

The cover head 220 is bonded to the surface of the compliance substrate 45 facing the +Z direction. In other words, the cover head 220 is bonded to the fixed substrate 47 so as to cover the opening 48. The space between the cover head 220 and the sealing film 46 is open to the atmosphere, allowing the compliance portion 49 of the sealing film 46 to deform in response to the pressure of the ink in the manifold 100.

The flow paths and adhesives of the liquid jet head 2 will be described in detail using Figures 8 to 12. Figure 8 is a plan view of the second relay flow path member 202 and the head chip 8. Figure 9 is a plan view of the head chip 8. Figure 10 is a cross-sectional view taken along line C-C in Figure 8. Figure 11 is a cross-sectional view taken along line D-D in Figure 8. Figure 12 is a cross-sectional view of an enlarged portion of Figure 11. Note that Figure 9 illustrates the first flow path connection adhesive 121 between the case member 40 and the second relay flow path member 202.

The first wiring insertion hole 32 and the second wiring insertion hole 43 of the head chip 8 communicate with the third wiring insertion hole 205 of the second relay flow path member 202, forming a storage space 130 in which the wiring member 110 is disposed. The third wiring insertion hole 205 has a shape that includes a recess 140 and the second wiring insertion hole 43 (described later) on the inside in a plan view looking in the Z-axis direction (see FIG. 8).

The head chip 8 is provided with a recess 140 recessed in the +Z direction, which is the ejection direction in which the nozzle ejects ink. In this embodiment, the case member 40 of the head chip 8 is provided with two recesses 140 recessed in the +Z direction from the opening of the second wiring insertion hole 43 on the -Z direction side. The two recesses 140 are arranged one on each side outside both ends of the second wiring insertion hole 43 that extends in the X-axis direction. The recess 140 arranged on the +X direction side of the second wiring insertion hole 43 is arranged between the two inlet ports 44a, and the recess 140 arranged on the -X direction side of the second wiring insertion hole 43 is arranged between the two outlet ports 44b.

A first adhesive A is placed in the recess 140. The recess 140 opens in the -Z direction and communicates with the third wiring insertion hole 205. Since the third wiring insertion hole 205 forms part of the accommodation space 130, it can also be said that the first adhesive A provided in the recess 140 is placed in the accommodation space 130.

Here, the first adhesive is an acrylic ultraviolet-curing adhesive capable of absorbing the monomer contained in the ultraviolet-curing ink. The ultraviolet-curing adhesive is an adhesive that contains a photopolymerization initiator, an acrylic polymer, a solvent that adjusts the hardness and viscosity, and the like. The first adhesive A is a first adhesive that is bonded only to one component that constitutes the liquid jet head 2. In other words, the first adhesive A is not bonded across two or more components that constitute the liquid jet head 2. In this embodiment, the first adhesive A is bonded only to the recess 140 of the case member 40.

As described above, the holding space 208 of the second relay flow path member 202 accommodates two head chips 8, and the opening of the second supply flow path 402 and the inlet 44a of the head chip 8 are liquid-tightly connected, and the opening of the second exhaust flow path 412 and the outlet 44b of the head chip 8 are liquid-tightly connected. Specifically, the second supply flow path 402 and the inlet 44a are connected in a state where the first flow path connection adhesive 121 is provided to surround the opening of the second supply flow path 402 and the opening of the inlet 44a. Similarly, the second exhaust flow path 412 and the outlet 44b are connected in a state where the first flow path connection adhesive 121 is provided to surround the opening of the second exhaust flow path 412 and the opening of the outlet 44b. By providing the first flow path connection adhesive 121 in this manner, ink is prevented from leaking between the second relay flow path member 202 and the head chip 8 from the joint between the second supply flow path 402 and the inlet 44a, and the joint between the second discharge flow path 412 and the outlet 44b.

As shown in FIG. 9, in this embodiment, the first flow path connection adhesive 121 is provided in four locations for one head chip 8 so as to surround the openings of the second supply flow path 402, the second discharge flow path 412, the inlet 44a, and the outlet 44b in order to provide a liquid-tight connection between them.

The head chip 8 is housed in the holding space 208 of the second relay flow path member 202, and its +Z side surface is adhered to the cover head 220. Specifically, the +Z side surface of the compliance substrate 45 is adhered to the -Z side surface of the cover head 220 with the second adhesive C and the fixing adhesive 150.

The second adhesive C is an acrylic ultraviolet-curing adhesive for bonding the compliance substrate 45 and the cover head 220, which are two components that make up the liquid jet head 2. The fixing adhesive 150 is an epoxy adhesive, but is not particularly limited. Although not shown, the second adhesive C is provided in a frame shape on the outer edge of the compliance substrate 45 when the head chip 8 is viewed in the -Z direction. The fixing adhesive 150 is provided on the +Z direction side surface of the compliance substrate 45, inside the second adhesive C. The second adhesive C is used to temporarily fix the compliance substrate 45 and the cover head 220 before the fixing adhesive 150 hardens.

The head chip 8 is also bonded to the +Z side surface of the case member 40 and the -Z side surface of the communication plate 15 with a second flow path connection adhesive 122. By bonding in this manner, the third manifold portion 42 of the case member 40 and the first manifold portion 17 of the communication plate 15 are liquid-tightly connected. By providing the second flow path connection adhesive 122 in this manner, leakage of ink to the outside of the head chip 8 from the joint between the third manifold portion 42 and the first manifold portion 17 is suppressed.

A first adhesive B is provided on the side of the communication plate 15 of the head chip 8. The first adhesive B is the first adhesive, and is attached only to one component that constitutes the liquid jet head 2. In other words, the first adhesive B is not attached across two or more components that constitute the liquid jet head 2. In this embodiment, the first adhesive B is attached only to the communication plate 15, and is provided in a ring shape to surround the side of the head chip 8.

The distance between the first adhesive A and the wiring member 110 is L1, the distance between the first flow path connecting adhesive 121 and the first adhesive A is L2, and the distance between the first flow path connecting adhesive 121 and the wiring member 110 is L3. Of the four flow paths in total, two flow paths in which the second supply flow path 402 and the inlet 44a are liquid-tightly connected, and two flow paths in which the second discharge flow path 412 and the outlet 44b are liquid-tightly connected, the distances L1, L2, and L3 are illustrated and explained for one of the flow paths in which the second supply flow path 402 and the inlet 44a are liquid-tightly connected. Distances L1, L2, and L3 can be defined for the other flow paths in the same way.

Distance L1 is the distance of the shortest imaginary straight line that passes through the inside of the storage space 130 and connects the first adhesive A and the wiring member 110. The straight line does not have to be a single straight line, but may be a combination of multiple straight lines. A straight line passing through the inside of the storage space 130 means that the straight line does not pass through any of the components that make up the liquid ejection head 2. In this embodiment, as shown in Figures 9 and 11, distance L1 is the total length of the combination of multiple imaginary straight lines that run from the first adhesive A to the wiring member 110 via the recess 140 and the third wiring insertion hole 205.

Distance L2 is the distance of the straight line from the first adhesive A to the first flow path connecting adhesive 121 that surrounds the joint portion, among the imaginary shortest straight lines connecting the joint portion between the inlet 44a and the second supply flow path 402 and the first adhesive A. In this embodiment, as shown in Figures 9 and 10, among the imaginary shortest straight lines connecting the first adhesive A to the joint portion between the inlet 44a and the second supply flow path 402 via the recess 140, the length of the part from the first adhesive A to the first flow path connecting adhesive 121 is distance L2.

Distance L3 is the distance of the straight line that passes through the inside of the storage space 130 and connects the wiring member 110 from the joint between the inlet 44a and the second supply flow path 402 to the wiring member 110 and the first flow path connection adhesive 121 that surrounds the joint. In this embodiment, as shown in Figures 9 and 10, of the imaginary shortest straight line from the wiring member 110 to the joint between the inlet 44a and the second supply flow path 402, the length of the part from the wiring member 110 to the first flow path connection adhesive 121 is distance L3.

These distances L1, L2, and L3 have the following relationship. That is, distance L1 is shorter than distance L3 (L1<L3). In other words, the first adhesive A is disposed closer to the wiring member 110 than the first flow path connection adhesive 121. Also, distance L1 is longer than distance L2 (L2<L1).

The distance between the first adhesive B and the second adhesive C is M1, the distance between the second flow path connection adhesive 122 and the first adhesive B is M2, and the distance between the second flow path connection adhesive 122 and the second adhesive C is M3.

Distance M1 is the distance of the shortest imaginary straight line connecting the first adhesive B and the second adhesive C without passing through the components that make up the liquid jet head 2. In this embodiment, as shown in FIG. 12, distance M1 is the length of an imaginary straight line that does not pass through the components that make up the liquid jet head 2, i.e., that passes through the inside of the holding space 208, and leads from the first adhesive B to the second adhesive C.

Distance M2 is the distance of the shortest imaginary straight line connecting the second flow path connection adhesive 122 and the first adhesive B without passing through the components constituting the liquid jet head 2. In this embodiment, as shown in FIG. 12, distance M2 is the length of the imaginary straight line from the second flow path connection adhesive 122 to the first adhesive B without passing through the components constituting the liquid jet head 2, i.e., passing through the inside of the holding space 208.

Distance M3 is the distance of the shortest imaginary straight line connecting the second flow path connection adhesive 122 and the second adhesive C without passing through the components that make up the liquid jet head 2. In this embodiment, as shown in FIG. 12, distance M3 is the length of the imaginary straight line that does not pass through the components that make up the liquid jet head 2, i.e., passes through the inside of the holding space 208, and leads from the second flow path connection adhesive 122 to the second adhesive C.

These distances M1, M2, and M3 have the following relationship. That is, distance M1 is shorter than distance M3 (M1<M3). In other words, the first adhesive B is disposed closer to the second adhesive C than the second flow path connection adhesive 122. Also, distance M1 is longer than distance M2 (M2<M1).

The first flow path connecting adhesive 121 and the second flow path connecting adhesive 122 are adhesives with low gas barrier properties. Low gas barrier properties refer to being made of a material with a gas permeability coefficient of oxygen of 1.00×10 ⁻⁵ cc mm/(mm ² ·day·atm) or more (including resin cases with low gas barrier properties). Adhesives with a gas permeability coefficient of oxygen of 1000×10 ⁻⁵ cc mm/(mm ² ·day·atm) or more (silicone adhesives) have particularly low gas barrier properties, so it is suitable to apply the present invention. The unit of the gas permeability coefficient is, for example, cc 20 μm/(m ² ·24 hrs ·atm). This unit represents the amount of gas that permeates per 24 hours when the film thickness is converted to 20 μm, the film area is 1 m ² , and the pressure is 1 atm (1 atmosphere).

The relay flow path member 200 and the case member 40 are formed from a resin material that does not contain polyphenylene sulfide (PPS) or a resin material with a low filler content. Generally, such resin materials have poor gas barrier properties.

As described above, the relay flow path member 200, the case member 40, and the first flow path connection adhesive 121 have poor gas barrier properties. Therefore, the monomer contained in the ultraviolet curable ink flowing in the ink flow paths, that is, the second supply flow path 402, the second discharge flow path 412, the inlet 44a, and the outlet 44b, may permeate the relay flow path member 200, the case member 40, and the first flow path connection adhesive 121 and leak out of the flow path. The monomer leaking out of the flow path may adhere to the metal wiring of the liquid ejection head 2 and corrode it.

For example, in the liquid jet head 2 of this embodiment, there is a risk that monomers contained in the ink may permeate the first flow path connecting adhesive 121 from the joint between the second supply flow path 402 and the inlet 44a and leak into the storage space 130. Similarly, there is a risk that monomers contained in the ink may permeate the first flow path connecting adhesive 121 from the joint between the second discharge flow path 412 and the outlet 44b and leak into the storage space 130. Monomers leaking from outside the flow path into the storage space 130 may corrode various metal wirings, such as the wiring formed in the wiring member 110 of the liquid jet head 2, the drive signal selection circuit 111, and the lead electrode 90 exposed inside the storage space 130.

To address this issue, the liquid jet head 2 of this embodiment is provided with a first adhesive A, which is an acrylic UV-curable adhesive capable of absorbing the monomer contained in the UV-curable ink, and the first adhesive A is adhered only to the case member 40 that constitutes the liquid jet head 2.

According to such a liquid jet head 2, the first adhesive A can absorb the monomer derived from the ink leaking from the second supply flow path 402, the inlet 44a, the second discharge flow path 412, and the outlet 44b, which are the flow paths of the liquid jet head 2. Since the first adhesive A absorbs the monomer in this way, it is possible to prevent the metal wiring of the liquid jet head 2 from being corroded by the monomer and to prevent the liquid jet head 2 from breaking down. Furthermore, the first adhesive A is provided only on the case member 40, and is not used to bond components such as the second relay flow path member 202 and the case member 40 that constitute the flow path. Therefore, although the first adhesive A absorbs the monomer and swells, it is possible to prevent those components from peeling off from each other or becoming misaligned.

The supply flow path 400 and the discharge flow path 410 formed in the relay flow path member 200, the manifold 100 formed in the head chip 8, the pressure chamber 12, the nozzle communication path 16, and the supply communication path 19 correspond to the flow paths through which the ultraviolet-curable ink flows.

In addition, in the liquid jet head 2 of this embodiment, the first adhesive A is disposed in the storage space 130. With such a liquid jet head 2, the monomer that has flowed into the storage space 130 can be absorbed by the first adhesive A, so that corrosion of the metal wiring of the wiring member 110 can be prevented.

The relay flow path member 200, the case member 40, the communication plate 15, the flow path forming substrate 10, and the compliance substrate 45 that form the flow path correspond to the flow path members.

In addition, in the liquid jet head 2 of this embodiment, a recess 140 is provided in the case member 40, and the first adhesive A is disposed in the recess 140 that is recessed in the +Z direction, which is the jetting direction. With such a liquid jet head 2, a puddle of monomer absorbed in the first adhesive A can be held in the recess 140. This makes it possible to prevent corrosion and failure of the liquid jet head 2 caused by the puddle coming into contact with the wiring member 110, etc. Even if the puddle overflows from the recess 140 and causes failure of the liquid jet head 2, it takes a considerable amount of time for the puddle to fill the recess 140, making it easy to extend the life of the liquid jet head 2.

The liquid jet head 2 of this embodiment has a second relay flow path member 202 having a second supply flow path 402 and a second discharge flow path 412, and a case member 40 having an inlet 44a and an outlet 44b, and the second supply flow path 402 and the inlet 44a are liquid-tightly connected by a first flow path connection adhesive 121 having low gas barrier properties, and the second discharge flow path 412 and the outlet 44b are liquid-tightly connected by a first flow path connection adhesive 121 having low gas barrier properties, and the first adhesive A is disposed closer to the wiring member 110 than the first flow path connection adhesive 121. That is, the distance L3 between the wiring member 110 and the first flow path connection adhesive 121 is longer than the distance L1 between the first adhesive A and the wiring member 110. According to such a liquid jet head 2, the monomer derived from the ink can be absorbed by the first adhesive A before it reaches the wiring member 110 having the metal wiring.

The second relay flow path member 202 corresponds to the first flow path member, the second supply flow path 402 and the second discharge flow path 412 correspond to the first flow path, the case member 40 corresponds to the second flow path member, the inlet 44a and the outlet 44b correspond to the second flow path, and the first flow path connection adhesive corresponds to the flow path connection adhesive.

In addition, in the liquid jet head 2 of this embodiment, the distance L1 between the wiring member 110 and the first adhesive A is longer than the distance L2 between the first flow path connection adhesive 121 and the first adhesive A. With such a liquid jet head 2, liquid puddles are less likely to reach the wiring member 110, so the life of the liquid jet head 2 can be extended.

As described above, the second flow path connecting adhesive 122 has low gas barrier properties. Therefore, the monomer contained in the ultraviolet curing ink flowing in the first manifold portion 17 and the third manifold portion 42, which are the ink flow paths, may permeate the second flow path connecting adhesive 122 and leak out of the flow path, i.e., outside the head chip 8. The monomer leaking out of the head chip 8 may come into contact with the second adhesive C that bonds the compliance substrate 45 and the cover head 220, which are components that constitute the liquid ejection head 2. Since the second adhesive C is an acrylic ultraviolet curing adhesive, it swells by absorbing the monomer, and may cause the compliance substrate 45 and the cover head 220 to peel off or become misaligned.

To address these issues, the liquid jet head 2 of this embodiment includes a second adhesive C, which is an acrylic ultraviolet-curing adhesive for bonding the compliance substrate 45 and the cover head 220, which are two components that constitute the liquid jet head 2, a case member 40 having a third manifold portion 42, and a communication plate 15 having a first manifold portion 17, and the third manifold portion 42 and the first manifold portion 17 are liquid-tightly connected by a second flow path connection adhesive 122, and includes a first adhesive B that is disposed closer to the second adhesive C than the second flow path connection adhesive 122.

With this type of liquid ejection head 2, the first adhesive B provided on the side of the communicating plate 15 is capable of absorbing monomers contained in the ultraviolet-curable ink, so that the monomers derived from the ink that leak outside the head chip 8 are absorbed by the first adhesive B, preventing the second adhesive C from swelling with the monomers. Therefore, it is possible to prevent peeling or misalignment between the compliance substrate 45 and the cover head 220 caused by swelling of the second adhesive C.

The cover head 220 and the compliance substrate 45 correspond to two components that constitute the liquid jet head 2. The first manifold portion 17 corresponds to the first flow path, and the third manifold portion 42 corresponds to the second flow path. The case member 40 corresponds to the first flow path member, and the communication plate 15 corresponds to the second flow path member. The second flow path connection adhesive 122 corresponds to the flow path connection adhesive.

In addition, in the liquid jet head 2 of this embodiment, the distance M1 between the second adhesive C and the first adhesive B is longer than the distance M2 between the second flow path connection adhesive 122 and the first adhesive B. With such a liquid jet head 2, the monomer derived from the ink can be absorbed by the first adhesive B before it reaches the second adhesive C that bonds the compliance substrate 45 and the cover head 220.

<Other embodiments>
Although each embodiment of the present invention has been described above, the basic configuration of the present invention is not limited to the above.

In the above embodiment, the first adhesive A is provided in the recess 140, but this is not limited to this. That is, the first adhesive A only needs to be provided inside the storage space 130 of the liquid jet head 2. Also, the recess 140 is formed in the case member 40, but this is not limited to this. That is, the recess 140 only needs to be provided in any member that forms the storage space 130. The first adhesive B is provided in the communication plate 15, but this is not limited to this. It only needs to be provided in any member of the liquid jet head 2.

The liquid jet head 2 described above is provided with the first adhesive A and the first adhesive B, but is not limited to this form. In other words, the liquid jet head 2 may be provided with only the first adhesive A or only the first adhesive B.

Here, the relationship in which the distance L1 between the first adhesive A and the wiring member 110 is shorter than the distance L3 between the first flow path connection adhesive 121 and the wiring member 110 is referred to as positional relationship A. The relationship in which the distance L1 is longer than the distance L2 between the first flow path connection adhesive 121 and the first adhesive A is referred to as positional relationship B. The aspect in which the positional relationship A and the positional relationship B are satisfied is referred to as positional relationship C. The liquid jet head 2 described above is an aspect in which the positional relationship C is satisfied, but is not limited to such an aspect. For example, the liquid jet head 2 may be configured such that the first adhesive A is disposed so as to satisfy only the positional relationship A, or the first adhesive A is disposed so as to satisfy only the positional relationship B.

The relationship in which the distance M1 between the first adhesive B and the second adhesive C is shorter than the distance M3 between the second flow path connection adhesive 122 and the second adhesive C is referred to as positional relationship D. The relationship in which the distance M1 is longer than the distance M2 between the second flow path connection adhesive 122 and the first adhesive B is referred to as positional relationship E. The aspect in which the positional relationship D and the positional relationship E are satisfied is referred to as positional relationship F. The liquid ejection head 2 described above is an aspect in which the positional relationship F is satisfied, but is not limited to such an aspect. For example, the liquid ejection head 2 may be configured such that the first adhesive B is disposed so as to satisfy only the positional relationship D, or the first adhesive B is disposed so as to satisfy only the positional relationship E.

In addition, the second supply flow path 402, the second discharge flow path 412, the inlet 44a, the outlet 44b, the first manifold section 17, and the third manifold section 42 are given as examples of flow paths, but are not limited to these. In addition, the second relay flow path member 202, the case member 40, and the communication plate 15 are given as examples of members that form these flow paths, but are not limited to these.

(Additional Note)
From the above-described exemplary embodiments, the following configurations can be understood, for example.

The liquid jet head according to aspect 1, which is a preferred aspect, is a liquid jet head that includes a nozzle for jetting acrylic ultraviolet-curable ink, and a flow path that communicates with the nozzle and through which the ultraviolet-curable ink flows, and includes a first adhesive that is an acrylic ultraviolet-curable adhesive capable of absorbing monomers contained in the ultraviolet-curable ink, and the first adhesive is bonded to only one component that constitutes the liquid jet head.

With this type of liquid jet head, the monomer derived from the ink leaking from the flow path of the liquid jet head can be absorbed by the first adhesive. By making the first adhesive absorb the monomer in this way, it is possible to prevent the metal wiring of the liquid jet head from being corroded by the monomer and to prevent the liquid jet head from breaking down. Furthermore, the first adhesive is provided on only one component and is not used to bond the components that make up the flow path together. Therefore, although the first adhesive absorbs the monomer and swells, it is possible to prevent the components from peeling off from each other or becoming misaligned.

In aspect 2, which is a specific example of aspect 1, a wiring member is provided that is disposed in a storage space that is inside a flow path member that forms the flow path, and the first adhesive is a first adhesive A that is disposed in the storage space. In this way, the monomer that has flowed into the storage space can be absorbed by the first adhesive A, thereby preventing corrosion of the metal wiring of the wiring member.

In aspect 3, which is a specific example of aspect 2, the flow path member has a recess that is recessed in the ejection direction in which the nozzle ejects the ultraviolet-curable ink, and the first adhesive A is disposed within the recess. This allows a puddle of monomer absorbed in the first adhesive A to be held in the recess. This makes it possible to prevent corrosion or malfunction of the liquid ejection head caused by the puddle coming into contact with wiring members, etc. Even if the puddle overflows from the recess and causes malfunction of the liquid ejection head, it takes a considerable amount of time for the puddle to fill the recess, which makes it easy to extend the life of the liquid ejection head.

In aspect 4, which is a specific example of aspect 2, the flow path member has a first flow path member having a first flow path that is a part of the flow path, and a second flow path member having a second flow path that is a part of the flow path, and the first flow path and the second flow path are liquid-tightly connected by a flow path connection adhesive with low gas barrier properties, and the first adhesive A is disposed closer to the wiring member than the flow path connection adhesive. In this way, the first adhesive A can absorb the monomer derived from the ink before it reaches the wiring board having metal wiring.

In aspect 5, which is a specific example of aspect 4, the distance between the wiring member and the first adhesive A is longer than the distance between the flow path connection adhesive and the first adhesive A. This makes it difficult for liquid pools to reach the wiring member, thereby extending the life of the liquid ejection head.

In aspect 6, which is a specific example of aspect 2, the flow path member has a first flow path member having a first flow path that is a part of the flow path, and a second flow path member having a second flow path that is a part of the flow path, the first flow path and the second flow path are liquid-tightly connected by a flow path connection adhesive having low gas barrier properties, and the distance between the wiring member and the first adhesive A is longer than the distance between the flow path connection adhesive and the first adhesive A.

In aspect 7, which is a specific example of aspect 1, the liquid jet head is provided with a second adhesive, which is an acrylic ultraviolet-curable adhesive, for bonding two components constituting the liquid jet head, a first flow path member having a first flow path that is a part of the flow path, and a second flow path member having a second flow path that is a part of the flow path, and the first flow path and the second flow path are liquid-tightly connected by a flow path connection adhesive with low gas barrier properties, and the first adhesive is a first adhesive B arranged closer to the second adhesive than the flow path connection adhesive. According to this, since the first adhesive B can absorb monomers contained in the ultraviolet-curable ink, the monomers derived from the ink that leak out to the outside of the liquid jet head are absorbed by the first adhesive B, and the second adhesive can be prevented from swelling with the monomer. Therefore, it is possible to prevent the two components constituting the liquid jet head from peeling off or being misaligned due to the swelling of the second adhesive.

In aspect 8, which is a specific example of aspect 7, the distance between the second adhesive and the first adhesive B is longer than the distance between the flow path connection adhesive and the first adhesive B. This allows the first adhesive B to absorb the monomer derived from the ink before it reaches the second adhesive that bonds the two components that make up the liquid jet head.

In aspect 9, which is a specific example of aspect 1, the liquid ejection head includes a second adhesive that is an acrylic ultraviolet-curable adhesive for bonding two components that constitute the liquid ejection head, a first flow path member having a first flow path that is a part of the flow path, and a second flow path member having a second flow path that is a part of the flow path, the first flow path and the second flow path are liquid-tightly connected by a flow path connection adhesive that has low gas barrier properties, and the first adhesive is a first adhesive B that is disposed at a position where the distance to the second adhesive is longer than the distance to the flow path connection adhesive.

A liquid ejection device according to aspect 10, which is a preferred aspect, includes the liquid ejection head according to any one of aspects 1 to 9, and a liquid storage section that stores the ultraviolet-curable ink to be supplied to the liquid ejection head. With this, even if monomers of the ultraviolet-curable ink pass through a portion of the liquid ejection head with low gas barrier properties, such as a silicone-based adhesive for connecting the flow path, and leak out of the flow path of the liquid ejection head, they are absorbed by the first adhesive, thereby providing a liquid ejection device that suppresses failure of the liquid ejection head and improves reliability.

A...first adhesive, B...first adhesive, C...second adhesive, 1...liquid injection device, 2...liquid injection head, 3...liquid storage section, 8...head chip, 10...flow path forming substrate, 12...pressure chamber, 15...communication plate, 17...first manifold section, 18...second manifold section, 19...supply communication passage, 20...nozzle plate, 21...nozzle, 30...protective substrate, 40...case member, 44a...inlet, 44b...outlet, 45... Compliance substrate, 100... manifold, 110... wiring member, 130... storage space, 140... recess, 150... fixing adhesive, 200... relay flow path member, 220... cover head, 300... piezoelectric element, 400... supply flow path, 401... first supply flow path, 402... second supply flow path, 403... supply side connection flow path, 410... discharge flow path, 411... first discharge flow path, 412... second discharge flow path, 413... discharge side connection flow path

Claims (10)

A liquid ejection head including: a nozzle for ejecting an acrylic ultraviolet curable ink; and a flow path communicating with the nozzle and through which the ultraviolet curable ink flows,
a first adhesive that is an acrylic ultraviolet-curable adhesive capable of absorbing a monomer contained in the ultraviolet-curable ink;
the first adhesive is bonded to only one component constituting the liquid ejection head;
A liquid jet head comprising: a wiring member disposed in a storage space inside a flow path member that forms the flow path,
The first adhesive is a first adhesive A disposed in the storage space.
The liquid jet head according to claim 1 . the flow path member has a recess that is recessed in a direction in which the nozzle ejects the ultraviolet curable ink,
The first adhesive A is disposed in the recess.
The liquid jet head according to claim 2 . the flow path member includes a first flow path member having a first flow path that is a part of the flow path, and a second flow path member having a second flow path that is a part of the flow path,
the first flow path and the second flow path are liquid-tightly connected by a flow path connecting adhesive having a low gas barrier property,
The first adhesive A is disposed closer to the wiring member than the flow path connecting adhesive.
The liquid jet head according to claim 2 . a distance between the wiring member and the first adhesive A is longer than a distance between the flow path connecting adhesive and the first adhesive A;
The liquid jet head according to claim 4 . the flow path member includes a first flow path member having a first flow path that is a part of the flow path, and a second flow path member having a second flow path that is a part of the flow path,
the first flow path and the second flow path are liquid-tightly connected by a flow path connecting adhesive having a low gas barrier property,
a distance between the wiring member and the first adhesive A is longer than a distance between the flow path connecting adhesive and the first adhesive A;
3. The liquid jet head according to claim 2. a second adhesive, which is an acrylic ultraviolet-curing adhesive for bonding two components constituting the liquid jet head;
A first flow path member having a first flow path that is a part of the flow path;
A second flow path member having a second flow path that is a part of the flow path;
Equipped with
the first flow path and the second flow path are liquid-tightly connected by a flow path connecting adhesive having a low gas barrier property,
The first adhesive is a first adhesive B arranged closer to the second adhesive than the flow path connecting adhesive.
The liquid jet head according to claim 1 . A distance between the second adhesive and the first adhesive B is longer than a distance between the flow path connecting adhesive and the first adhesive B.
The liquid jet head according to claim 7 . a second adhesive, which is an acrylic ultraviolet-curing adhesive for bonding two components constituting the liquid jet head;
A first flow path member having a first flow path that is a part of the flow path;
A second flow path member having a second flow path that is a part of the flow path;
Equipped with
the first flow path and the second flow path are liquid-tightly connected by a flow path connecting adhesive having a low gas barrier property,
The first adhesive is a first adhesive B that is disposed at a position where a distance from the first adhesive to the second adhesive is longer than a distance from the first adhesive to the flow path connecting adhesive.
The liquid jet head according to claim 1 . A liquid jet head according to any one of claims 1 to 9,
a liquid storage section that stores the ultraviolet curable ink to be supplied to the liquid ejection head;
A liquid ejection apparatus comprising:

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