JP2011068023A - Nozzle plate and method for manufacturing nozzle plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nozzle plate that makes it easy to form a nozzle. <P>SOLUTION: The nozzle plate 8 attached to the discharging surface of an inkjet head 1 includes: a nozzle base material 41 made of resin; an intermediate layer 42 provided on the discharging side of the nozzle base material 41 and containing metal; and an ink repelling layer 43 provided on the discharging side of the intermediate layer 42 and made of an organic material containing sulfur. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a nozzle plate attached to an ejection surface of an inkjet head and a method for manufacturing the nozzle plate.

  There is known a nozzle plate in which nozzles for ejecting ink are formed and attached to the ejection side of an inkjet head. Patent Document 1 discloses a nozzle plate including a metal plate and a resin film thinner than the metal plate. In the nozzle plate manufacturing method of Patent Document 1, a polyimide resin film is formed on a metal plate. Thereafter, a photoresist is formed, and a part of the nozzle is formed on the metal plate by etching the metal plate. Next, another photoresist is formed, and the polyimide resin film is etched, thereby forming the nozzle of the metal plate and the nozzle penetrating the polyimide resin film. As a result, nozzles for ejecting ink are formed on the nozzle plate.

Japanese Patent No. 3092134

  However, in the nozzle plate of Patent Document 1 described above, since the resin film is configured to be thicker than the metal plate, there is a problem that a process for forming the nozzle by etching twice is complicated.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a nozzle plate that can easily form nozzles and a method for manufacturing the nozzle plate.

  In order to achieve the above object, the invention according to claim 1 is a nozzle plate attached to an ejection surface of an ink jet head, wherein the nozzle plate made of resin, and the ejection surface of the nozzle substrate are provided with a metal. And a protective layer having an organic material containing sulfur provided on a discharge surface of the intermediate layer.

  The invention according to claim 2 is characterized in that the organic material of the protective layer is a thiol compound.

  The invention according to claim 3 is characterized in that the organic material of the protective layer is a thiol compound containing an oleophobic group.

  The invention according to claim 4 is characterized in that the organic material of the protective layer is a thiol compound containing a linear alkyl group.

Further, an invention according to claim 5, the organic material of the protective layer is, when the lipophobic based on _{X, SH-C m H 2m} -X-C n H 2n -SH (m, n: even number) of It is a thiol compound represented by a chemical formula.

In the invention according to claim 6, the m and n are
m = n
It is characterized by being.

In the invention according to claim 7, the n is
8 ≦ n ≦ 18
It is characterized by being.

  The invention according to claim 8 is characterized in that the intermediate layer has a resin in which a late transition metal is selectively coordinated to a resin constituting the nozzle base material.

  Further, the invention according to claim 9 includes a step of treating the discharge surface of the resin nozzle base material with an alkaline solution, and treating the discharge surface of the nozzle base material with an acidic salt aqueous solution. And forming a protective layer made of thiol on the discharge surface of the intermediate layer, and forming an intermediate layer in which metal is selectively coordinated on the discharge surface.

  Since the invention of claim 1 has the resin nozzle base material, the intermediate layer containing metal can be thinned to an arbitrary thickness. Thus, according to the first aspect of the present invention, a conductive nozzle can be easily formed. Moreover, since the intermediate layer contains a metal, the protective layer containing sulfur and the intermediate layer can be covalently bonded to suppress peeling.

  According to invention of Claim 2, since a protective layer consists of a thiol compound, a protective layer can be comprised with the dense monomolecular film by which the self-organization was carried out.

  According to invention of Claim 3, since the thiol compound which comprises a protective layer contains an oleophobic group, a protective layer can repel oil-based ink. Thereby, it can suppress that a protective layer is contaminated with an ink solvent.

  According to invention of Claim 4, since the thiol compound which comprises a protective layer contains a linear alkyl group, compared with the thiol compound containing a branched alkyl group, a protective layer is made dense by self-organization. can do.

  According to the invention of claim 5, since the two integers (m, n) indicating the carbon number of the alkyl group of the thiol compound constituting the protective layer are even numbers, the molecules in the monomolecular film are regularly arranged on the nozzle surface. Cheap. Thereby, a protective layer can be made denser.

  According to the invention of claim 6, since the two integers (m, n) indicating the carbon number of the alkyl group of the thiol compound constituting the protective layer are equal, the arrangement of molecules in the monomolecular film constituting the protective layer The regularity can be further improved, and at the same time, the oleophobic group can be arranged on the outermost surface of the protective layer.

  According to the invention of claim 7, by setting “n” indicating the carbon number of the alkyl group of the thiol compound constituting the protective layer to 8 or more, the thiol compound molecule becomes a substantially cylindrical body. Thereby, a protective layer becomes denser. Moreover, by making “n” 18 or less, the macroscopic stereoregularity of the protective layer can be adjusted. The stereoregularity here means the surface smoothness of the protective layer, and the smoothness of the surface of the protective layer is improved by adjusting the stereoregularity of the protective layer.

  According to invention of Claim 8, since an intermediate | middle layer contains a late period transition metal, the protective layer which consists of a thiol compound can be made into a monomolecular film more easily self-organizing.

  According to the invention of claim 9, by forming an intermediate layer in which a metal is coordinated on the surface of the nozzle substrate, the protective layer made of a thiol compound is formed as a monomolecular film, and the conductive protective layer and the intermediate layer And the charge generated on the nozzle surface and the charge of the ink droplet can be quickly neutralized.

1 is an overall perspective view of an inkjet head according to a first embodiment. It is sectional drawing along the II-II line of FIG. It is sectional drawing along the III-III line of FIG. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3. It is sectional drawing of the nozzle plate of the nozzle vicinity. It is an expanded sectional view for demonstrating the layer structure of a nozzle plate. It is a figure explaining the chemical reaction at the time of forming an intermediate | middle layer. It is a figure explaining the process of forming a nozzle plate. It is a figure explaining the process of forming a nozzle plate. It is a figure explaining the process of forming a nozzle plate. It is a figure explaining the manufacturing process of an inkjet head. It is a figure explaining the manufacturing process of an inkjet head. FIG. 7 is a view corresponding to FIG. 6 of a nozzle plate according to a second embodiment. FIG. 7 is a view corresponding to FIG. 6 of a nozzle plate according to a third embodiment.

(First embodiment)
Hereinafter, a first embodiment of an ink jet head for oil-based ink having a nozzle plate according to the present invention will be described with reference to the drawings. FIG. 1 is an overall perspective view of the inkjet head according to the first embodiment. 2 is a longitudinal sectional view taken along line II-II in FIG. FIG. 3 is a longitudinal sectional view taken along line III-III in FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a sectional view of the nozzle plate in the vicinity of the nozzle. FIG. 6 is an enlarged cross-sectional view for explaining the layer structure of the nozzle plate. In the following description, the vertical and horizontal directions indicated by the arrows in FIG.

  As shown in FIGS. 1 to 6, the inkjet head 1 according to the first embodiment includes a head substrate 2, a first piezoelectric member 3, a second piezoelectric member 4, a fixture 5, a pair of electrodes 6, 7 and a nozzle plate 8.

  The head substrate 2 is made of resin. The head substrate 2 includes a standing member 15, a hollow member 16, and a side wall member 17. In addition, the standing member 15, the hollow member 16, and the side wall member 17 are integrally formed.

  The standing member 15 is formed in a rectangular parallelepiped shape. The standing member 15 is provided at the upper portion of the central portion in the horizontal direction of the inkjet head 1. The standing member 15 is configured to extend upward from the upper surface of the hollow member 16.

  The hollow member 16 is formed in a hollow rectangular parallelepiped shape. The hollow member 16 is configured to cover the upper part of the second piezoelectric member 4. The lower surface of the hollow member 16 is in close contact with the upper surface of the second piezoelectric member 4. As shown in FIGS. 3 and 4, an ink supply chamber 32 to which ink 31 is supplied from a main tank (not shown) of the printing apparatus is formed inside the hollow member 16. The lower surface and the left side surface of the ink supply chamber 32 are opened.

  The side wall member 17 is formed in a rectangular parallelepiped shape. The side wall member 17 is configured to cover the right side surface of the inkjet head 1. An ink supply hole 17 a is formed in the central portion of the side wall member 17 in the front-rear direction. The ink supply hole 17 a connects the outside and the ink supply chamber 32. A supply pipe 35 is connected to the ink supply hole 17a. The supply pipe 35 supplies the ink 31.

  The first piezoelectric member 3 applies pressure to the ink 31 by deformation. The first piezoelectric member 3 is made of PZT having a rectangular parallelepiped shape. The first piezoelectric member 3 is provided on the left side of the head substrate 2 and the second piezoelectric member 4. The upper portion of the right side surface of the first piezoelectric member 3 is fixed in close contact with the left side surface of the hollow member 16 of the head substrate 2. As a result, the left side surface of the ink supply chamber 32 is closed by the upper right side surface of the first piezoelectric member 3. The lower part of the right side surface of the first piezoelectric member 3 is fixed in close contact with the left side surface of the second piezoelectric member 4.

  As shown in FIGS. 2 and 4, a plurality of first grooves 21 are formed in the lower part of the right side surface of the first piezoelectric member 3. The plurality of first grooves 21 constitute part of the ink chamber 33 that stores the supplied ink 31. The plurality of first grooves 21 are formed at equal intervals in the front-rear direction. The first groove 21 is formed in a rectangular parallelepiped shape. The right side surface and the lower surface of the first groove 21 are opened. On the other hand, the front and rear surfaces, the left side surface, and the upper surface of the first groove 21 are closed.

  The second piezoelectric member 4 applies pressure to the ink 31 by being deformed together with the first piezoelectric member 3. The second piezoelectric member 4 is made of PZT having a rectangular parallelepiped shape. The second piezoelectric member 4 is provided on the lower surface of the hollow member 16 of the head substrate 2 and between the side wall member 17 and the first piezoelectric member 4. The left side surface of the second piezoelectric member 4 is fixed in close contact with the lower right side surface of the first piezoelectric member 3.

  As shown in FIGS. 3 and 4, a plurality of second grooves 22 are formed on the left side surface of the second piezoelectric member 4. The plurality of second grooves 22 constitute part of the ink chamber 33 that stores the supplied ink 31. The plurality of second grooves 22 are formed at equal intervals in the front-rear direction. The plurality of second grooves 22 are formed in a rectangular parallelepiped shape. The left side surface of the second groove 22 is opened. The second groove 22 is formed at a position facing the first groove 21. As a result, when the first piezoelectric member 3 and the second piezoelectric member 4 are combined, the first groove 21 and the second groove 22 constitute an ink chamber 33. In other words, the ink chamber 33 is formed by the first piezoelectric member 3 and the second piezoelectric member 4. The lower surface of the second groove 22 is opened in the same manner as the lower surface of the first groove 21. Thereby, the lower surface (ejection surface) of the ink chamber 33 is opened so that the ink 31 can be ejected. The upper surface of the second groove 22 is opened. As a result, the ink supply chamber 32 and the ink chamber 33 formed in the hollow member 16 of the head substrate 2 are connected. On the other hand, the front and rear surfaces and the right side surface of the second groove 22 are closed.

  The fixture 5 fixes the head base 2 and the piezoelectric members 3 and 4. The fixture 5 is made of resin. The fixture 5 presses the right side surface of the head base 2 and the left side surface of the first piezoelectric member 3 in the left-right direction. The fixture 5 presses the front surface and the rear surface of the head substrate 2 and the piezoelectric members 3 and 4 in the front-rear direction. Thereby, the head substrate 2 and the piezoelectric members 3 and 4 are in close contact with each other. An opening 5 a for discharging the ink 31 is formed on the bottom surface of the fixture 5.

  The electrodes 6 and 7 apply voltage to the piezoelectric members 3 and 4. As shown in FIGS. 2 to 4, the electrodes 6 and 7 are formed on the inner surfaces of the first groove 21 and the second groove 22 constituting the ink chamber 33. In other words, the electrodes 6 and 7 are formed on the inner surfaces of the piezoelectric members 3 and 4 constituting the ink chamber 33. The electrodes 6 and 7 are alternately provided in the front-rear direction. The electrodes 6 and 7 are connected to a control unit (not shown) mounted on a printing apparatus (not shown). A predetermined voltage for deforming the piezoelectric members 3 and 4 is applied between the electrodes 6 and 7 by the control unit. Thereby, the piezoelectric members 3 and 4 in the region sandwiched between the electrode 6 and the electrode 7 are deformed, and pressure can be applied to the ink 31.

  The nozzle plate 8 is provided across the lower surface (discharge surface) of the first piezoelectric member 3 and the lower surface (discharge surface) of the second piezoelectric member 4. The nozzle plate 8 is formed in a substantially rectangular planar shape. A plurality of nozzles 8 a are formed on the nozzle plate 8. The nozzle 8a is formed so as to penetrate the nozzle plate 8 in the vertical direction. The plurality of nozzles 8a are formed at equal intervals at positions corresponding to the ink chambers 33 in the front-rear direction. Thereby, the lower surface of each ink chamber 33 is penetrated with the exterior by each nozzle 8a. As shown in FIG. 1, the plurality of nozzles 8 a are formed so as to be alternately shifted left and right one by one in the left-right direction. That is, the nozzle 8 a is formed at a position corresponding to either the first groove 21 or the second groove 22.

  As shown in FIGS. 5 and 6, the nozzle plate 8 includes a nozzle substrate 41, an intermediate layer 42, and a soot ink layer (corresponding to a protective layer in claims) 43.

  The nozzle substrate 41 is formed in a substantially rectangular plate shape. The upper surface of the nozzle substrate 41 is bonded to the ejection surface (lower surface) of the piezoelectric members 3 and 4. The nozzle substrate 41 is made of a polyimide resin excellent in chemical stability.

  The intermediate layer 42 is for forming the ink layer 43 and simultaneously imparting conductivity. The intermediate layer 42 is formed on the entire discharge surface (lower surface) of the nozzle substrate 41. The intermediate layer 42 is made of a silver salt of polyamic acid in which silver ions, which are late transition metals, are selectively coordinated with the polyimide resin constituting the nozzle base material 41. The intermediate layer 42 is grounded. That is, the intermediate layer 42 is configured integrally with the nozzle base material 41 and can remove the charge of the ink. Silver functions as a Lewis acid.

The soot ink layer 43 repels the ink 31. The ink layer 43 is formed on the entire ejection surface (lower surface) of the intermediate layer 42. The ink layer 43 is made of bis (mercaptooctyl) ether, which is a kind of organic material thiol compound. Incidentally, the chemical formula of bis (mercaptomethyl octyl) ethers _{are SH-C 8 H 16 -O-} C 8 H 16 -SH. Bis (mercaptooctyl) ether has an ether group which connects an alkyl group and an alkyl group and has a polar component and oleophobic properties (hydrophilicity). That is, the bis (mercaptooctyl) ether constituting the ink layer 43 has a property of repelling oil-based ink (oleophobic). Moreover, both ends of bis (mercaptooctyl) ether have a pair of mercapto groups (SH-). Here, the sulfur (S) of the mercapto group functions as a Lewis base because of its high covalent bond. Thereby, as shown in FIG. 6, the mercapto groups (—SH) at both ends of the bis (mercaptooctyl) ether form a covalent bond with the intermediate layer 42 containing silver. As a result, the ether group exhibiting oleophobicity is oriented outward (discharge side). Bis (mercaptooctyl) ether has a structure in which a pair of identical linear alkyl groups (—C ₈ H ₁₆ —: octyl group) are bonded to both sides of an ether group. The soot ink layer 43 made of a thiol compound is formed as a self-assembled monomolecular film. The ink layer 43 has a thickness of about 2 nm to about 200 nm.

(Operation of inkjet head)
First, the control unit of the printing apparatus switches on an ink pump (not shown). Thereby, the ink 31 is supplied from the main tank to the ink supply chamber 32 and the ink chamber 33 of the inkjet head 1. Next, the control unit applies a voltage to the electrodes 6 and 7 according to the input image data while conveying the printing paper. Thereby, the piezoelectric members 3 and 4 are deformed. In the ink chamber 33 compressed by the deformation of the piezoelectric members 3 and 4, pressure acts on the ink 31, so that the ink 31 in the ink chamber 33 is ejected from the nozzle 8 a of the nozzle plate 8. The ejected ink 31 becomes droplets and is applied to a printing paper to print an image.

  Here, the ejected droplet-shaped ink 31 is charged by a voltage applied between the electrodes 6 and 7. When the charged ink 31 enters an energy state that exceeds the surface tension, the droplet state cannot be maintained, causing a split (Rayleigh split). Once this Rayleigh split occurs, it occurs continuously. This causes an electrostatic atomization phenomenon in which the droplets of the ink 31 become mist. The mist-like ink 31 reaches the lower surface of the nozzle plate 8. However, the electrically conductive ink layer 43 is on the lower surface of the nozzle plate 8 and neutralizes the charged ink droplets. Even if Rayleigh splitting of the ink droplet occurs, the ink 31 is repelled by the ink layer 43 because the ink layer 43 made of oleophobic bis (mercaptooctyl) ether is formed. As a result, it is possible to suppress the ink 31 from adhering to the lower surface of the nozzle plate 8.

(Inkjet head manufacturing process)
Next, the manufacturing process of the inkjet head 1 will be described. FIG. 7 is a diagram illustrating a chemical reaction when forming the intermediate layer. 8-10 is a figure explaining the process of forming a nozzle plate. 11 and 12 are diagrams for explaining the manufacturing process of the inkjet head.

  First, manufacture of the nozzle plate 8 will be described. Specifically, first, a nozzle substrate 41 made of polyimide shown in FIG. 7A is prepared. Next, potassium hydroxide (KOH) is dissolved in a mixed solution of water and ethylene glycol (water: ethylene glycol = 1: 3 [volume ratio]) to prepare a surface treatment solution. The concentration of potassium hydroxide in the surface treatment solution is 5 mol / l. As shown in FIG. 8, after this surface treatment solution is applied to the ejection surface of the nozzle substrate 41 made of polyimide resin, it is allowed to stand for about 5 minutes to about 10 minutes. Thereby, as shown in FIG. 7B, the imide ring of the polyimide resin on the surface of the nozzle substrate 41 is cleaved by alkaline hydrolysis with potassium hydroxide in the surface treatment solution, and the carboxyl group and the amino group. Is formed. As a result, an intermediate layer 42 a made of the potassium salt of polyamic acid shown in FIG. 9 is formed on the discharge surface of the nozzle substrate 41.

  Next, the intermediate layer 42a formed on the discharge surface of the nozzle base material 41 on which the potassium salt is formed is immersed in an aqueous silver nitrate solution having a concentration of 50 mmol / l for about 5 minutes. Thereby, as shown in FIG. 7C, a silver salt of polyamic acid in which potassium ions are ion-exchanged with silver ions is formed. As a result, the intermediate layer 42 in which the discharge surface of the polyimide resin constituting the nozzle substrate 41 is coordinated and selected by silver is formed.

  Next, bis (mercaptooctyl) ether is dissolved in an alcohol such as ethanol to prepare an ink layer solution having a volume molar concentration of bis (mercaptooctyl) ether of 1 mol / l. Thereafter, as shown in FIG. 10, the soot ink layer solution is applied to the ejection surface of the intermediate layer 42. In this state, the nozzle substrate 41 is left at room temperature. As a result, the alcohol in the ink layer solution evaporates, and the ink layer 43 made of bis (mercaptooctyl) ether is formed on the ejection surface of the intermediate layer 42. Here, bis (mercaptooctyl) ether, which is a thiol compound, self-assembles into a monomolecular film.

  Next, the head substrate 2 and the first piezoelectric member 3 and the second piezoelectric member 4 on which the electrodes 6 and 7 are formed are assembled. Thereafter, the head base 2 and the piezoelectric members 3 and 4 are fixed by the fixing tool 5.

  Next, as shown in FIG. 11, the surface opposite to the discharge side of the nozzle substrate 41 is bonded to the lower surfaces of the piezoelectric members 3 and 4. In this state, as shown in FIG. 12, a laser beam 55a is irradiated from the laser device 55 to a desired position of the nozzle plate 8 to form the nozzle 8a. As a result, the inkjet head 1 is completed.

(Effect of 1st Embodiment)
Next, effects of the nozzle plate 8 and the inkjet head 1 according to the first embodiment described above will be described.

  As described above, the nozzle plate 8 has the nozzle base material 41 made of polyimide resin. For this reason, the intermediate layer 42 containing a metal can be made thin. Thereby, the nozzle 8a can be easily formed by the laser beam 55a.

  In addition, the nozzle plate 8 includes a conductive intermediate layer 42 containing a late-cycle transition metal and a soot ink layer 43 made of bis (mercaptooctyl) ether having an oleophobic ether group formed on the ejection surface. . Thereby, the charged ink droplet can be neutralized during printing. Further, even if the ejected ink 31 in the form of a mist is generated, the ink 31 is not repelled by the soot ink layer 43 and deposited on the soot ink layer 43. As a result, it is possible to prevent the discharge surface of the nozzle plate 8 from becoming dirty, so that the cleaning work using a wiper or the like can be reduced. Further, by reducing the cleaning work by the wiper, it is possible to suppress the scratch that is one of the causes of ink adhesion from being generated in the soot ink layer 43. As a result, the nozzle plate 8 can more effectively suppress the ink 31 from adhering to the soot ink layer 43.

  Further, the nozzle plate 8 can suppress the nozzle 8 a from being blocked by the color material of the aggregated ink 31 by suppressing the adhesion of the ink 31 by the ink layer 43. As a result, the nozzle plate 8 can reduce the discharge of the ink 31 in a direction different from the desired direction (directly downward direction), so that deterioration in the quality of the printed image can be suppressed.

  Further, the fountain ink layer 43 of the nozzle plate 8 is made of bis (mercaptooctyl) ether having a mercapto group. Thereby, the nozzle plate 8 can be constituted by a dense monomolecular film in which the ink layer 43 is self-organized.

  Further, the ink layer 43 of the nozzle plate 8 is composed of bis (mercaptooctyl) ether having a pair of mercapto groups. Thereby, the mercapto groups at both ends of the bis (mercaptooctyl) ether molecule are covalently bonded to the intermediate layer 42 containing silver. As a result, the nozzle plate 8 can further strengthen the bond between the ink layer 43 and the intermediate layer 42, and therefore can suppress the peeling of the ink layer 43.

  Further, the fountain ink layer 43 of the nozzle plate 8 is composed of bis (mercaptooctyl) ether having the same linear octyl group on both sides of the ether group. Thereby, the nozzle plate 8 can make the ink layer 43 denser than that of the thiol compound having a branched octyl group.

(Second Embodiment)
Next, a second embodiment in which a part of the above-described embodiment is changed will be described. FIG. 13 is a view corresponding to FIG. 6 of the nozzle plate according to the second embodiment. In addition, the same code | symbol is attached | subjected to the structure similar to embodiment mentioned above, and description is abbreviate | omitted.

As shown in FIG. 13, the nozzle plate 8 </ b> A according to the second embodiment includes a fountain ink layer 43 </ b> A made of mercaptooctyl ether containing one mercapto group (—SH). The chemical formula of mercaptooctyl ether is OH—C ₈ H ₁₆ —SH. Even in such a configuration, the mercapto group (—SH) of the mercaptooctyl ether is covalently bonded to the silver of the intermediate layer 42. On the other hand, since the ether group is disposed on the ejection side, the oil-based ink 31 is repelled.

  Thereby, also in the nozzle plate 8A by 2nd Embodiment, there can exist an effect similar to 1st Embodiment.

(Third embodiment)
Next, a third embodiment in which a part of the above-described embodiment is changed will be described. FIG. 14 is a view corresponding to FIG. 6 of the nozzle plate according to the third embodiment. In the third embodiment, the present invention is applied to a nozzle plate for water-based ink. The same components as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

As shown in FIG. 14, the nozzle plate 8B according to the third embodiment includes a soot ink layer 43B made of n-octanethiol. Incidentally, the chemical formula of n- octane thiol _is C ₈ H 17 -SH. Even in such a configuration, the mercapto group (—SH) of n-octanethiol is covalently bonded to the silver of the intermediate layer 42. On the other hand, since the hydrophobic alkyl group (—C ₈ H ₁₇ ) is disposed on the ejection side, the ink layer 43B repels the water-based ink 31.

  Thereby, the nozzle plate 8 </ b> B according to the third embodiment can achieve the same effects as the first embodiment with respect to the water-based ink 31.

  As mentioned above, although this invention was demonstrated in detail using embodiment, this invention is not limited to embodiment described in this specification. The scope of the present invention is determined by the description of the scope of claims and the scope equivalent to the description of the scope of claims. Hereinafter, modified embodiments in which the above-described embodiment is partially modified will be described.

  The shape, numerical value, arrangement, material, and the like of each configuration of the above-described embodiment can be changed as appropriate.

  Further, the ink layer (protective layer) may be composed of an organic material containing sulfur such as a disulfide group (—S—S—), a monosulfide group (—S—), and thiophene.

  In the case of a nozzle plate for oil-based ink, an oleophobic group (hydrophilic group) in the ink layer may have a polar component such as a carbonyl group other than an ether group, an ester group, or an imino group. Furthermore, the ink layer may be made of a material having a plurality of oleophobic groups (hydrophilic groups). On the other hand, in the case of a nozzle plate for water-based ink, a hydrophobic group other than an alkyl group may be applied as the hydrophobic group.

  Further, in the case of a nozzle plate for oil-based ink, the soot ink layer may be composed of an organic material such as bis (mercaptooctyl) ether or a thiol compound having an oleophobic group (hydrophilic group) other than mercaptooctylether. On the other hand, in the case of a nozzle plate for water-based ink, the soot ink layer may be composed of an organic material such as a thiol compound having a hydrophobic group other than n-octanethiol.

Here, when the ink-jet layer is composed of a thiol compound, the alkyl group (—C _n H _2n —) is preferably linear. As a result, the ink layer that is self-organized can be made denser.

May also be constituted by a thiol compound represented the發ink layer by the chemical formula _{SH-C m H 2m -X-} C n H 2n -SH. Furthermore, the relationship between m and n indicating the number of carbon atoms is preferably “m = n”. Here, X is an oleophobic group. More specifically, an ether group is preferable, but it may be a carbonyl group, an ester group or an imino group.

The structure, formula _{OH-C n} H 2n -SH an發ink layer, the formula _{SH-C n H 2n -O-} C n H 2n -SH, or by thiol compound represented by chemical formula _C n _{H 2n} + 1 -SH In this case, it is preferable that “8 ≦ n ≦ 18”.

_OH-C n _H 2n _-SH is "8 ≦ _{n", SH-C n H 2n -O} -C n H 2n -SH or, in _the case of C _{n H 2n} + 1 -SH, semiempirical molecular orbital calculation software It can be seen that the heat of formation of the thiol compound calculated by MOPAC (NMDO as a Hamiltonian) is relatively low at “−43.48 kcal / mol” or less, so that alteration and decomposition of the thiol compound can be further suppressed.

In the case of OH—C _n H _2n —SH or “SH—C _n H _2n —O—C _n H _2n —SH” or “C _n H _{2n + 1} —SH” where “8 ≦ n”,
CPP ≒ 1
(CPP: Critical Packing Parameter)
Therefore, the molecule becomes a substantially cylindrical body shape. Thereby, the self-organization of the thiol compound can be improved, and the denseness of the ink layer can be improved. CPP is
CPP = V / (A ・ L)
V: Occupied volume of hydrophobic part (alkyl group) of alkanethiol
A: Occupied area of mercapto group (-SH) of alkanethiol
L: Expressed by the length of the hydrophobic portion (alkyl group) of alkanethiol.

On the other hand, in the case of OH—C _n H _2n —SH, SH—C _n H _2n —O—C _n H _2n —SH, or C _n H _{2n + 1} —SH where “n ≦ 18”, polyhydric alcohol, etc. It is easily dissolved in a solvent and can be easily handled in the step of forming the ink layer. In addition, the thiol compound of “n ≧ 19” has a high viscosity and generally exhibits a property of being hardly soluble in a solvent.

Further,發ink layer formula _{OH-C n H 2n -SH,} SH-C n H 2n -O-C n H 2n -SH _, or when configuring a thiol compound represented by C _{n H 2n} + 1 -SH , “M” and “n” are preferably even numbers. As a result, the alkyl chains of the thiol compound are somewhat regularly arranged horizontally with respect to the lower surface of the intermediate layer, and the denseness of the ink layer can be improved. As a result, the stability and durability of the soot ink layer can be improved.

  The step of forming the soot ink layer described above can be changed as appropriate.

  Further, after forming the ink layer, polyethylene glycol or propylene glycol may be treated. Thereby, the ink layer can be made denser.

  Moreover, the metal contained in the intermediate layer can be appropriately changed. The material applied instead of the intermediate layer silver (Ag) can be arbitrarily selected from late transition metals. This is because sulfide (mercapto group (S-H)) acts as a soft Lewis base due to its high covalent bond, and easily forms a strong bond with a late transition metal. Among the late transition metals, gold (Au) and silver (Ag) are particularly suitable because they act as strong Lewis acids (electron acceptors) (Source: Novel Sterically Hindered Substituted Ferrocenes and Their Transition Metal Complexes. Author: GREGSON CKA et al., Material: Organometallics, Volume page: Vol.23, No.15, Page.3674-3682 (2004.07.19)). Other late transition metals that can be suitably used include platinum group elements (ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), platinum (Pt)), or Iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), etc. can be raised.

  The intermediate layer may be formed of a metal thin film formed by CVD (chemical vapor deposition) or the like. Here, as the material of the metal thin film constituting the intermediate layer, the above-described silver, gold or the like can be applied. The intermediate layer may be grounded.

  The material constituting the nozzle substrate may be made of a resin other than polyimide, for example, an epoxy resin, a urethane resin, an acrylic resin, a polyethylene resin, or the like.

  Moreover, the manufacturing method of a nozzle plate can be changed suitably. In the embodiment described above, the soot ink layer formed from the liquid phase may be formed from the gas phase.

DESCRIPTION OF SYMBOLS 1 Inkjet head 2 Head base material 3 Piezoelectric member 4 Piezoelectric member 5 Fixture 5a Opening part 6, 7 Electrode 8, 8A, 8B Nozzle plate 8a Nozzle 15 Standing member 16 Hollow member 17 Side wall member 17a Ink supply hole 21 1st groove | channel 22 Second groove 31 Ink 32 Ink supply chamber 33 Ink chamber 35 Supply piping 41 Nozzle base material 42, 42a Intermediate layers 43, 43A, 43B Ink layer 55 Laser device 55a Laser light

Claims (9)

In the nozzle plate attached to the ejection surface of the inkjet head,
A resin nozzle substrate;
Provided on the discharge surface of the nozzle substrate, an intermediate layer containing metal,
A nozzle plate comprising: a protective layer having an organic material containing sulfur provided on a discharge surface of the intermediate layer.   The nozzle plate according to claim 1, wherein the organic material of the protective layer is a thiol compound.   The nozzle plate according to claim 1, wherein the organic material of the protective layer is a thiol compound containing an oleophobic group.   The nozzle plate according to any one of claims 1 to 3, wherein the organic material of the protective layer is a thiol compound containing a linear alkyl group. The organic material of the protective layer, when the lipophobic based on _{X, SH-C m H 2m} -X-C n H 2n -SH (m, n: even number) and characterized in that it is a thiol compound represented by the chemical formula The nozzle plate according to any one of claims 1 to 4. M and n are
m = n
The nozzle plate according to claim 5, wherein: N is
8 ≦ n ≦ 18
The nozzle plate according to claim 6, wherein:   The nozzle according to any one of claims 2 to 7, wherein the intermediate layer has a resin in which a post-period transition metal is selectively coordinated with a resin constituting the nozzle base material. plate. A step of treating the discharge surface of the resin nozzle substrate with an alkaline solution;
A step of forming an intermediate layer in which metal is selectively coordinated on the discharge surface of the nozzle substrate by treating the discharge surface of the nozzle substrate with an aqueous acid salt solution;
And a step of forming a protective layer made of a thiol compound on the discharge surface of the intermediate layer.