JP2018126953A - Device for discharging liquid - Google Patents

Abstract

In an apparatus for ejecting liquid, even if a liquid repellent film is provided on a nozzle plate, for example, a liquid having a low surface tension, such as a penetrant and a surfactant, cannot be stably ejected.
An apparatus for discharging liquid includes a nozzle for discharging liquid, and a nozzle plate having a liquid repellent film on a liquid discharge surface side and an inner wall surface side of the nozzle, and the liquid repellent film includes a fluorine-containing film. A fluororesin containing a structural unit having a heterocyclic structure is contained, and the relationship between the dynamic surface tension A and the static surface tension B at 15 ms of the liquid is 1.5 ≦ A / B ≦ 2, and the liquid is 15 ms. The dynamic surface tension A in is 25 mN / m or more and 35 mN / m or less.
[Selection] Figure 2

Description

  The present invention relates to an apparatus for discharging a liquid.

  In the apparatus for ejecting liquid, ink is one of the liquids ejected from the nozzles, and an ink jet recording method is used as the ejection method. The ink jet recording method has an advantage that the process is simpler than other recording methods and full color can be easily obtained, and a high-resolution image can be obtained even with an apparatus having a simple configuration. For this reason, the ink jet recording system is spreading from personal use to office use, commercial printing, or industrial printing. However, in the ink jet recording system, when water-based pigment ink is used to record on commercial or publication printed coated paper, the ink absorption may not be in time for fixing and beading (density unevenness) may occur. As measures to prevent beading, a penetrating agent such as a hydrophobic solvent or a surfactant is added to the ink to reduce the surface tension of the ink, and the ink in the ink after landing is dried by penetrating into the recording medium. Attempts have been made to speed up the process.

  As for the nozzle, it is known to provide a liquid repellent film on the liquid ejection surface side of the nozzle plate. As the liquid repellent film, for example, use of a copolymer resin of tetrafluoroethylene and perfluorodimethyldioxole (Teflon (registered trademark) AF, manufactured by DuPont) is disclosed (for example, see Patent Document 1). ing.

  However, even if a liquid repellent film is provided on the nozzle plate in an apparatus for ejecting liquid, there arises a problem that a liquid having a low surface tension, such as a penetrant and a surfactant, cannot be ejected stably.

  An apparatus for discharging a liquid according to the present invention as means for solving the problem includes a nozzle for discharging a liquid, and a nozzle plate having a liquid repellent film on a liquid discharge surface side and an inner wall surface side of the nozzle. The liquid repellent film contains a fluororesin containing a structural unit having a fluorine-containing heterocyclic structure, and the relationship between the dynamic surface tension A and the static surface tension B of the liquid at 15 ms is 1.5 ≦ A / B. ≦ 2 and the dynamic surface tension A at 15 ms of the liquid is 25 mN / m or more and 35 mN / m or less.

  According to the present invention, there is an effect that a liquid having a low surface tension can be stably ejected in a liquid ejecting apparatus.

FIG. 1 is an explanatory plan view showing an example of a nozzle plate in an apparatus for ejecting liquid. FIG. 2 is an enlarged cross-sectional explanatory view showing an example of one nozzle portion of a nozzle plate in the apparatus for ejecting liquid. FIG. 3 is an explanatory plan view of a nozzle hole portion for explaining the film thickness of the liquid repellent film. FIG. 4 is an explanatory diagram for explaining an example of a method for manufacturing a nozzle plate. FIG. 5 is an explanatory diagram for explaining vacuum deposition. FIG. 6A is an SEM photograph of the liquid repellent film for explaining the state before baking. FIG. 6B is an SEM photograph of the liquid repellent film for explaining the state before baking. FIG. 7A is an SEM photograph of the liquid repellent film for explaining the state after baking. FIG. 7B is an SEM photograph of the liquid repellent film for explaining the state after baking. FIG. 8 is an external perspective explanatory view showing an example of a liquid discharge head in the apparatus for discharging a liquid of the present invention. FIG. 9 is a cross-sectional explanatory diagram in a direction (liquid chamber longitudinal direction) orthogonal to the nozzle arrangement direction along the line AA in FIG. 8. FIG. 10 is a cross-sectional explanatory diagram in the nozzle arrangement direction (liquid chamber short direction) along the line BB in FIG. 8. FIG. 11 is an explanatory plan view of an essential part showing an example of an apparatus for discharging a liquid according to the present invention. FIG. 12 is an explanatory side view of a main part showing another example of the apparatus for ejecting liquid according to the present invention. FIG. 13 is an explanatory plan view showing a main part of an example of a liquid discharge unit in the apparatus for discharging a liquid according to the present invention. FIG. 14 is an explanatory front view showing another example of the liquid discharge unit in the apparatus for discharging a liquid according to the present invention.

  Hereinafter, modes for carrying out the present invention will be described.

(Device for discharging liquid and method for discharging liquid)
The apparatus for ejecting liquid according to the present embodiment includes a nozzle that ejects liquid, and a nozzle plate that has a liquid repellent film on at least a part of the liquid ejection surface side and the inner wall surface side of the nozzle. And a fluorine resin containing a structural unit having a fluorine-containing heterocyclic structure, and the relationship between the dynamic surface tension A and the static surface tension B at 15 ms of the liquid is 1.5 ≦ A / B ≦ 2, The dynamic surface tension A at 15 ms is 25 mN / m or more and 35 mN / m or less.

  The apparatus for ejecting the liquid according to the present embodiment and the method for ejecting the liquid according to the present embodiment have a weak force for forming a meniscus in the nozzle hole with a conventional liquid having a low surface tension. This is based on the knowledge that when the liquid is ejected by the nozzle, jet bending occurs.

<Nozzle plate>
The nozzle plate preferably has a nozzle base material and a liquid repellent film on the nozzle base material, and preferably has a silane coupling agent layer between the nozzle base material and the liquid repellent film. Has other layers.

-Nozzle substrate-
The nozzle substrate is provided with nozzle holes, and the number, shape, size, material, structure, etc. of the nozzle holes are not particularly limited and can be appropriately selected according to the purpose. Hereinafter, the case where the nozzle base material is provided with two nozzle faces that communicate with each other will be described. Of these two opposing surfaces, one surface on the side where liquid is discharged from the nozzle hole during use is referred to as a liquid discharge surface, and the other surface opposite to the liquid discharge surface is referred to as a liquid chamber bonding surface. .

  There is no restriction | limiting in particular as a planar shape of a nozzle base material, According to the objective, it can select suitably, For example, a rectangle, a square, a rhombus, a circle, an ellipse etc. are mentioned. Moreover, as a cross-sectional shape of a nozzle base material, flat shape, plate shape, etc. are mentioned, for example. There is no restriction | limiting in particular as a magnitude | size of a nozzle base material, According to the magnitude | size of a nozzle plate, it can select suitably.

The material of the nozzle substrate is not particularly limited and can be appropriately selected depending on the purpose. For example, stainless steel, Al, Bi, Cr, InSn, ITO, Nb, Nb ₂ O ₅ , NiCr, Si, _{SiO 2, Sn, Ta 2 O} 5, Ti, W, ZAO (ZnO + Al 2 O 3), Zn and the like. These may be used alone or in combination of two or more. Among these, stainless steel is preferable from the viewpoint of rust prevention.

  There is no restriction | limiting in particular as stainless steel, According to the objective, it can select suitably, For example, austenitic stainless steel, ferritic stainless steel, martensitic stainless steel, precipitation hardening stainless steel, etc. are mentioned. These may be used alone or in combination of two or more.

  At least the surface of the nozzle substrate on the liquid discharge side may be subjected to oxygen plasma treatment to introduce hydroxyl groups from the viewpoint of improving the adhesion between the liquid repellent film and the nozzle substrate.

-Nozzle hole-
The number, arrangement, interval, opening shape, opening size, opening cross-sectional shape, and the like of the nozzle holes are not particularly limited and can be appropriately selected according to the purpose. There is no restriction | limiting in particular as an arrangement | sequence of a nozzle hole, According to the objective, it can select suitably, For example, the several nozzle hole is arranged in a line at equal intervals along the length direction of a nozzle base material. An aspect etc. are mentioned. The arrangement of the nozzle holes can be appropriately selected according to the type of liquid to be ejected, but is preferably 1 to 4 rows, more preferably 1 to 4 rows. There is no restriction | limiting in particular as the number of nozzle holes per row, Although it selects suitably according to the objective, 10 or more and 10,000 or less are preferable, and 50 or more and 500 or less are more preferable. The interval (pitch) P that is the shortest distance between the centers of adjacent nozzle holes is not particularly limited and may be appropriately selected depending on the intended purpose. For example, it is preferably 21 μm or more and 169 μm or less. There is no restriction | limiting in particular as an opening shape of a nozzle hole, According to the objective, it can select suitably, For example, circular, an ellipse, a square etc. are mentioned. Among these, a circular shape is preferable from the viewpoint of discharging ink droplets.

-Liquid repellent film-
The liquid repellent film is a film containing a fluororesin including a structural unit having a fluorine-containing heterocyclic structure. The liquid repellent film is preferable because it includes a structural unit having a fluorine-containing heterocyclic structure, so that the surface free energy becomes very small, and even an ink having a low surface tension used in the present embodiment can be kept in a wet state. .

It is preferable that the inner wall surface of the nozzle also has a liquid repellent film from the viewpoint of holding a meniscus in a low surface tension liquid. The liquid repellent film on the inner wall surface of the nozzle means that, for example, the liquid discharge surface of the nozzle plate in TOF-SIMS (manufactured by ALVAC-PHI, PHI nanoTOF II ^™ ) and the liquid chamber joint on the opposite side This can be confirmed by observing from the surface. In addition, when a liquid repellent film is deposited without attaching a tape to the side opposite to the liquid ejection surface of the nozzle plate, it is observed that the liquid repellent film is deposited near the nozzle holes on the liquid chamber joint surface of the nozzle plate. Therefore, it can be inferred that the inner wall surface of the nozzle also has a liquid repellent film.

  The liquid repellent film on the liquid ejection surface side preferably has a slope region that is inclined in a direction in which the film thickness becomes thinner toward the edge side of the nozzle hole at the outer peripheral portion of the edge of the nozzle hole. In addition, the slope of the slope region may be slanted in a straight line with a cross-sectional shape, or may be slanted in a curved shape. In the liquid-repellent film on the liquid ejection surface side, the area other than the slope area has a substantially constant film thickness and is flat. When the slope region is provided, the edge of the liquid repellent film on the nozzle hole side is located at a deeper position than the surrounding liquid repellent film, and therefore the wiper member is less likely to interfere with the edge of the liquid repellent film. It is preferable from the viewpoint of reducing and preventing catching on the edge of the liquid repellent film and reducing deterioration of the edge of the liquid repellent film. Having a slope region can be confirmed, for example, by taking out a nozzle cross-section by ion polishing and observing with a scanning electron microscope (SEM).

-Structural unit having fluorine-containing heterocyclic structure-
As the polymer having a structural unit having a fluorine-containing heterocyclic structure, it is preferable to use an amorphous polymer among the fluorine-containing polymers having a heterocyclic structure. Since the amorphous polymer is excellent in film strength, adhesion to a substrate, film uniformity, etc., the effect of this embodiment can be further exhibited.

  Examples of the structural unit having a fluorine-containing heterocyclic structure include, for example, U.S. Pat. No. 3,418,302, U.S. Pat. No. 3,978,030, JP-A 63-238111, JP-A 63-238111. Structural units described in JP-A-63-238115, JP-A-1-131214, JP-A-1-131215 and the like are preferably used.

  The fluorine-containing heterocyclic structure preferably has an ether bond from the viewpoint of obtaining a film with good sliding property against ink having a low static surface tension and improving the cleaning property of the nozzle surface. Examples of the structural unit having a fluorine-containing heterocyclic structure include the following structural units having a heterocyclic structure, but are not limited thereto.

However, in the general formula (i) and _{(ii), Rf 1, Rf} 2, and Rf ₃ each represents a fluorine-containing alkyl group.

  Furthermore, in order to control the adhesion with the base material, the glass transition temperature (Tg), and the solubility in a solvent, a structural unit represented by the following general formula (iii) is introduced into the main chain. These structural units may be introduced by copolymerizing with monomers composed of structural units represented by the following structural formulas (vii) to (ix).

[General Formula (iii)]
However, in the general formula _{(iii), R 4, R} 5, and _{R 6} are each a hydrogen atom, a fluorine atom, a chlorine atom, or an Rf _4. However, Rf ₄ is a fluorine-containing alkyl group. X represents a hydrogen atom, a fluorine atom, a chlorine atom, Rf ₅ , or Rf ₆ . However, Rf ₅ is acid, ester, a fluorine-containing organic substituent having alcohol, amine, a functional group of amides to the end, Rf ₆ is a fluorine-containing alkyl group, or a fluorine-containing ether group.

[Structural Formula (vii)]

[Structural Formula (viii)]

[Structural Formula (ix)]

  Examples of those having the specific chemical structure as described above and suitable for a liquid-repellent film include, for example, trade name: Cytop CTX-105 (manufactured by Asahi Glass Co., Ltd.), trade name: Cytop CTX-805 (Asahi Glass). Product name: Teflon (registered trademark) AF1600, product name: AF2400 (manufactured by DuPont), and the like.

  Examples of the method for forming a liquid repellent film using a polymer composed of a structural unit having a fluorine-containing heterocyclic structure include, for example, spin coating, roll coating, dipping and the like using a fluorine-based solvent, printing, and vacuum deposition. Is mentioned.

  The fluorine-based solvent is not particularly limited as long as it can dissolve a polymer having a fluorine-containing heterocyclic structure in the main chain, and can be appropriately selected according to the purpose. For example, perfluorobenzene, “Product name: Afludo” (trade name: Fluorine solvent manufactured by Asahi Glass Co., Ltd.), “Fluorinert FC-75” (trade name: liquid containing perfluoro (2-butyltetrahydrofuran) manufactured by 3M), etc. Fluorine solvents are preferred. These may be used alone or in combination of two or more. Among these, in the case of a mixed solvent, hydrocarbons, chlorinated hydrocarbons, fluorinated hydrocarbons, alcohols, or other organic solvents can be used in combination. The solution concentration is preferably 0.01% by mass or more and 50% by mass or less, and more preferably 0.01% by mass or more and 20% by mass or less.

  The heat treatment condition (temperature) of the polymer composed of the structural unit having a fluorine-containing heterocyclic structure is determined by the boiling point of the solvent, the glass transition temperature of the polymer, and the heat resistance temperature of the substrate. That is, a temperature higher than the boiling point of the solvent and the glass transition temperature of the polymer and lower than the heat resistance temperature of the substrate may be selected. The glass transition temperature of a polymer composed of a structural unit having a fluorine-containing heterocyclic structure varies depending on the structure. For example, many structural structures of structural formula (iv) to structural formula (vi) have a temperature of 50 ° C. or higher and 110 ° C. or lower. Therefore, the heat treatment conditions are as follows. Time is preferred. In addition, unless otherwise specified, the symbol of the wave dash "-" used in order to show a range in this embodiment shall include the value described before and after that.

  The fluororesin including a structural unit having a fluorine-containing heterocyclic structure preferably includes a structural unit represented by the following structural formula (x).

  A fluororesin having a structural unit of the general formula (ii) and a structural unit represented by the structural formula (x) in the main chain is sold by DuPont under the trade name “Teflon (registered trademark) AF”.

  Teflon (registered trademark) AF changes its glass transition temperature (Tg) by changing its copolymerization ratio. That is, as the ratio of the PDD [perfluoro (2,2-dimethyl-1,3-dioxole)] component increases, the glass transition temperature (Tg) increases. The glass transition temperature is 80 ° C. or higher and 330 ° C. or lower depending on the component ratio, and is commercially available at 160 ° C. (trade name: Teflon (registered trademark) AF1600, manufactured by DuPont) and 240 ° C. (trade name). : Teflon (registered trademark) AF2400, manufactured by DuPont). For example, the heat treatment temperature of 160 ° C. is preferably 165 ° C. or more and 180 ° C. or less in consideration of the heat resistant temperature of the substrate.

  The average film thickness of the liquid repellent film on the liquid ejection surface side is preferably 1 μm or more and 3 μm or less. In order to obtain a smooth surface without the unevenness provided on the nozzle base material affecting the surface of the fluororesin layer constituting the liquid repellent film, the liquid repellent film preferably has an average film thickness of 1 μm or more. From the viewpoint of maintaining the nozzle shape and nozzle diameter, a thinner one is preferable. When the average film thickness of the liquid repellent film is in the range of 1 μm or more and 3 μm or less, it is preferable from the viewpoint of wiping durability and the shape of the nozzle. The average film thickness can be measured by, for example, cross-sectional SEM observation.

  The arithmetic average roughness Ra of the liquid repellent film (fluororesin layer) is preferably 1.0 nm or less. When the average roughness Ra is 1.0 nm or less, the nozzle surface becomes extremely smooth, wiping residue due to wiping is reduced, and wear resistance is also excellent.

  The arithmetic average roughness Ra is defined as follows. In the section of length L, only the reference length is extracted from the roughness curve in the direction of the average line, the X axis is taken in the direction of the average line of the extracted portion, and the Y axis is taken in the direction of the vertical magnification. When the roughness curve is represented by y = f (x), the value obtained by the following mathematical formula (1) is represented by micrometers (μm).

  The arithmetic average roughness Ra was measured by a force tapping mode (in the air) of an atomic force microscope (manufactured by Bruker Ax, Dimension Icon). The cantilever was a low spring constant silicon cantilever (OMCL-AC240TS-C3, manufactured by Olympus Corporation), and the measurement length was 10 μm.

  Between the number average molecular weight C of the fluororesin containing a structural unit having a fluorine-containing heterocyclic structure in the liquid repellent film at the interface with the base, and the number average molecular weight D of the fluororesin on the outermost surface of the liquid repellent film, C It is preferable that there is a relationship <D. That is, when the molecular weight in the liquid repellent film at the interface with the base is relatively low, the molecular motion becomes active in a high temperature environment, and the bonding state with the base becomes good. On the other hand, when the molecular weight on the outermost surface of the liquid repellent film is relatively high, durability against physical wear is improved on the outermost surface of the film that is in direct contact with the wiping member.

  The number average molecular weight in the depth direction of the liquid repellent film can be achieved by controlling the temperature at the time of resin deposition using the property of evaporating preferentially from low molecular weight by gradually increasing the temperature. It is. The average molecular weight of the fluororesin in the liquid repellent film can be measured by GPC. The measurement results of the number average molecular weight in the liquid repellent film according to one embodiment were C = 240,000 and D = 290,000.

-Silane coupling agent layer-
It is preferable to have a silane coupling agent layer containing a silane coupling agent between the nozzle substrate and the liquid repellent layer. As the silane coupling agent, a coupling agent having an amino group is preferable, and 3-aminopropyltriethoxysilane is particularly preferable. Specifically, KBE-903 (made by Shin-Etsu Chemical Co., Ltd.), A1100 (made by Momentive Performance Materials), etc. are mentioned. The formation of the silane coupling agent layer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a dipping method, a spin coating method, and a spray method.

  The amino group in the coupling agent having an amino group has good affinity with the ether part of the heterocyclic ring in the molecule of the fluororesin. For this reason, the fixing property of a fluororesin is greatly improved by providing a silane coupling agent having an amino group on the silica layer.

  Here, the nozzle plate used in one embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is an explanatory plan view of a nozzle plate, and FIG. 2 is an enlarged sectional explanatory view of one nozzle portion.

  The nozzle plate 1 includes a nozzle base material 20 in which a nozzle hole 21 serving as a nozzle 11 for discharging liquid is formed, an intermediate layer 30 formed on the surface of the nozzle base material 20, a liquid ejection surface side, and an inner wall surface side. And a liquid repellent film 40 formed on the substrate.

  The nozzle substrate 20 is, for example, a metal flat plate member. The nozzle base material 20 is, for example, a metal flat plate member made of stainless steel, but is not limited thereto.

The intermediate layer 30 is composed of one or a plurality of layers such as, for example, a SiO ₂ layer or a silane coupling agent layer that serves as a base layer.

  The liquid repellent film 40 is a film containing a fluororesin (hereinafter, also referred to as “fluororesin layer”) including a structural unit having a fluorine-containing heterocyclic structure.

  In the liquid repellent film 40, a slope region 41 a having a slope 41 a that is inclined in a direction in which the film thickness decreases toward the edge 11 a side of the nozzle 11 in the outer peripheral portion of the edge 11 a of the nozzle 11 on the liquid ejection surface. There is. Note that the slope 41a of the slope region 41 may have a cross-sectional shape that is slanted linearly or may be slanted in a curved shape. The region 42 other than the slope region except the slope region 41 of the liquid repellent film 40 has a substantially constant thickness and is flat.

  As described above, the liquid repellent film 40 has the slope region 41 that is inclined toward the edge side of the nozzle 11 in the outer peripheral portion of the nozzle 11, so that the nozzle of the liquid repellent film 40. Since the edge on the 11th side is located behind the surrounding liquid repellent film 40, the wiper member is less likely to interfere with the edge of the liquid repellent film 40, and the wiper member is caught by the edge of the liquid repellent film 40. Can be reduced or prevented.

  In the nozzle plate 1, the intermediate layer 30 is also formed on the inner wall surface of the nozzle hole 21 of the nozzle substrate 20, and the liquid repellent film 40 is also formed on the inner wall surface of the nozzle 11. Here, the film thickness t2 of the liquid repellent film 40b on the inner wall surface of the nozzle 11 (corresponding to the wall surface of the nozzle hole 21 of the nozzle base material 20) is 1/10 of the film thickness t1 of the region 42 of the liquid repellent film 40a. Hereinafter, it is preferable to satisfy (t2 / t1 <0.1).

  As the film thickness t2 of the liquid repellent film 40b on the inner wall surface of the nozzle 11 increases, the nozzle diameter varies as the film thickness increases. On the other hand, as the film thickness t1 of the liquid repellent film 40a on the surface side of the liquid discharge side is generally thicker, the durability is improved.

  The liquid repellent film 40 having the opposite film thickness can be obtained, for example, by forming a film using a vapor phase method. The film thickness is measured by taking out the nozzle cross section by ion polishing and observing with SEM. Thus, the relationship between the film thickness t2 of the liquid repellent film 40b on the inner wall surface of the nozzle 11 and the film thickness t1 of the region 42 of the liquid repellent film 40a is evaluated. In the case where the ratio of t2 / t1 exceeds 0.1, a liquid repellent film is formed by a dip method, and then the dip liquid flowing into the nozzle is blown and opened by blowing air into the nozzle. A sample can be obtained by drying. As a result, the presence / absence of the injection curve was t2 / t1 <0.05: none, t2 / t1 <0.10: none, and t2 / t1 ≧ 0.3: existence. From this, if t2 / t1 <0.10, the injection bending can be reduced or prevented.

  The average film thickness on the liquid discharge surface side of the liquid repellent film 40 is preferably 1 μm or more and 3 μm or less. Here, the film thickness of the liquid repellent film will be described with reference to FIG. FIG. 3 is an explanatory plan view of a nozzle hole portion used for the description.

  As shown in FIG. 3, the film thickness was measured at 20 points on a circumference CC 5 μm away from the edge 11a of the nozzle 11 on the normal line from the edge 11a to the edge 11a in the opposite direction to the nozzle center 11o. The arithmetic average of the population with the desired film thickness is defined as the average film thickness m.

In Equations (2) and (3), N = 20, and Xi is the film thickness in the i-th measurement.

  Then, the amount obtained by the following mathematical formula (3) is defined as dispersion, and the positive square root σ of this dispersion is taken as the standard deviation of the population (film thickness).

  Here, the smaller the variation coefficient “thickness standard deviation σ / average film thickness m” means that the film thickness variation with respect to the film thickness is small and flat.

  The average film thickness a on the circumference CC was measured with an ellipsometer at a spot diameter of 10 μm in diameter at equal intervals around the circumference CC. When the presence or absence of liquid wiping residue on the surface after wiping when this σ / m was changed was evaluated, σ / m = 0.03: none, σ / m = 0.06: none, σ / m = 0. 09: None, σ / m = 0.12: Existence, σ / m = 0.15: Existence In the case where there is no wiping residue of the liquid, the ejection bending of the discharged liquid does not occur. Therefore, by setting σ / m <0.1, the injection bending can be reduced.

  In addition, the intermediate layer 30 is preferably a silane coupling agent layer in which the layer serving as the base of the liquid repellent film 40 has an amino group. Thereby, high adhesion is obtained by the interaction between the amino group and the liquid repellent film material.

  Next, an example of a nozzle plate manufacturing method will be described with reference to FIG. FIG. 4 is an explanatory diagram for explaining the same.

  In the base material preparation step of FIG. 4A, the mirror plate polishing step and the pre-step of the cleaning step are performed on the metal flat plate member that becomes the nozzle base material 20. In addition, the nozzle base material 20 opens the nozzle hole 21 by press work to the metal flat plate member of length 30mm, width 15mm, and thickness 0.05mm, for example.

  As the metal flat plate member, stainless steel as a typical example of an iron-based alloy can be used. “Stainless steel” is steel having a Cr content of 10.5% or more, as described in JIS G0203: 2000, 4201, and various steel types can be used.

  If the steel type is austenitic, Cr: 10.5 mass% to 35 mass%, preferably 11 mass% to 30 mass%, Ni: about 5 mass% to 30 mass%, if ferrite, Cr A steel grade of about 10.5 mass% to 35 mass%, preferably about 15 mass% to 30 mass% can be employed. For example, the steel grade prescribed | regulated to JIS G4305: 2005 and JIS G4312-1991 can be illustrated. Alternatively, stainless steel in which other alloy elements are added based on these standard steel types and various properties are improved can be used.

  As the nickel-base alloy, a highly corrosion-resistant Ni—Cr—Fe alloy containing Cr: 12 mass% to 27 mass% and Fe: 5 mass% to 18 mass% can be used. This type of alloy is known as an “Inconel alloy”.

  Then, the metal flat plate member is punched from the side opposite to the discharge surface, and burrs generated by the punching are removed by polishing or chemical etching.

Next, in the intermediate layer forming step of FIG. 4B, as the intermediate layer 30, a SiO ₂ film 31 is formed on the surface of the nozzle substrate 20 by sputtering or the like, and a tape is formed on the surface opposite to the liquid discharge surface side. After affixing 60, a silane coupling agent layer 32 is formed on the surface of the SiO ₂ film 31.

  Here, as the silane coupling agent, a coupling agent having an amino group is preferable, and 3-aminopropyltriethoxysilane is particularly preferable. Specific examples include KBE-903 (manufactured by Shin-Etsu Chemical Co., Ltd.) and A1100 (momentive performance material). The silane coupling agent layer 32 may be formed by any method such as a dipping method, a spin coating method, or a spray method.

  Thereafter, a film forming process of the liquid repellent film 40 shown in FIG. 4C is performed, and a liquid repellent material is deposited on the nozzle substrate 20 by a vapor deposition method. At this time, the liquid repellent film 40 is formed on the surface of the silane coupling agent layer 32 on the nozzle substrate 20.

Fluorine resin containing a structural unit having a fluorine-containing heterocyclic structure, under a high vacuum of ^{1.5 × 10 -3 Pa~8.0 × 10 -3} Pa, heated to 350 ° C. to 420 ° C., the deposited film Vacuum deposition is performed until the thickness on the nozzle substrate 20 facing the vapor deposition source becomes 1 μm to 3 μm. FIG. 5 is an explanatory diagram for explaining vacuum deposition. For example, as shown in FIG. 5, the vacuum deposition is performed by disposing the deposition source 501 and the nozzle substrate 20 in the vacuum chamber 500.

  There is no particular limitation on the method of forming the slope region that is inclined in the direction in which the film thickness decreases toward the edge side of the nozzle hole in the outer peripheral portion of the edge of the nozzle hole of the liquid repellent film on the liquid ejection surface. The slope region can be easily formed by vacuum deposition.

  Subsequently, as shown in FIG. 4D, a flattening step by annealing (heat treatment) is performed. The nozzle substrate 20 is not particularly heated, and a film obtained by vapor deposition at a desired temperature is baked (annealed) at a temperature equal to or higher than the glass transition point Tg of the fluororesin.

  The baking may be any method such as a convection drying furnace, a circulating air drying furnace, a flash annealing apparatus, a halogen lamp heater, or a vacuum dryer, but is preferably performed in a nitrogen atmosphere. The baking temperature is preferably 20 ° C. to 30 ° C. higher than the glass transition point Tg of the fluororesin. For example, when the glass transition point Tg is 160 ° C. (Teflon (registered trademark) AF1600), heating at about 180 ° C. is preferable. . By baking (annealing) at a temperature equal to or higher than the glass transition point Tg of the fluororesin, the liquid repellent film 40 has a slanted region 41 that is dense, has a smooth surface, and becomes thinner as it approaches the edge of the nozzle 11. It becomes a fluororesin film.

  FIG. 6A is an SEM photograph of the liquid repellent film for explaining the state before baking. FIG. 6B is an SEM photograph of the liquid repellent film for explaining the state before baking. FIG. 7A is an SEM photograph of the liquid repellent film for explaining the state after baking. FIG. 7A is an SEM photograph of the liquid repellent film for explaining the state after baking. For example, before baking, as shown in FIGS. 6A and 6B, there are pores 600 inside the film, the surface of the film has a contact angle with pure water of 114 °, and the arithmetic average roughness Ra = 8 nm. On the other hand, after baking, as shown in FIGS. 7A and 7B, there are no cavities inside the film, the surface of the film has a contact angle with respect to pure water of 129 °, and the arithmetic average roughness Ra is 1 nm or less.

  Further, the surface of the fluororesin film was tapered (slope shape) within the range of 40 nm from the edge 11a of the nozzle 11, and became a flat surface outside the periphery of 40 nm.

  Note that heat treatment (annealing) may be performed during the vapor deposition step instead of performing the heat treatment after the vapor deposition step (FIG. 4C). By depositing the fluororesin while heating the nozzle substrate 20, the surface of the fluororesin can be smoothed even by heat treatment at a temperature that does not reach the glass transition point (Tg) of the fluororesin.

  Next, a method for forming a liquid repellent film will be described. The liquid repellent film formed on the nozzle substrate by vapor deposition using a fluororesin containing a structural unit having a fluorine-containing heterocyclic structure is different from the liquid repellent film obtained by the liquid phase method (for example, dipping). It turned out that it became a micro uneven state. Further, as described above, there are pores inside the membrane. Therefore, in the case of a liquid having a low surface tension such as a liquid to which a surfactant is added or a liquid made of an organic solvent, the original liquid repellency of the fluororesin provided on the nozzle surface cannot be ensured.

  Therefore, in the above embodiment, by heating the liquid repellent film after vapor deposition or during vapor deposition, the liquid repellent film is caused to flow, thereby smoothing the surface of the film and eliminating pores inside the film. Yes. Therefore, when the liquid repellent film is heated after vapor deposition, the heat treatment is performed at a temperature equal to or higher than the glass transition point Tg of the fluororesin. On the other hand, heating at a temperature significantly higher than the glass transition point (Tg) melts and breaks the film shape with high dimensional accuracy obtained by the vapor phase method, and therefore 20 ° C. to 30 ° C. from the glass transition point Tg. It is preferable to heat-treat the liquid-repellent film after film formation at a high temperature.

  Moreover, when performing heat processing during a vapor deposition process, a fluororesin is vapor-deposited, heating the nozzle base material 20. As shown in FIG. Thereby, since the liquid repellent film immediately after being formed on the nozzle substrate 20 is heated, the heat treatment can be performed at a temperature that does not reach the glass transition point Tg. In this case, a material having a relatively low heat resistance can be selected as the material used for the nozzle substrate and the intermediate layer. The penetration rate of the liquid repellent film into the nozzle holes is expressed by the following mathematical formula (4). In this embodiment, the case where the inner wall surface of the nozzle also has a liquid repellent film is defined as the case where the penetration rate represented by the following formula (4) is 20% or more and 100% or less.

[Formula 4]

  In the vapor deposition method, a uniform liquid repellent film having a desired thickness or less can be formed on the inner wall of the nozzle without post-treatment. In the dip method or the spin coat method, the nozzle hole is blocked by the liquid repellent film, and thus a post-treatment for penetrating the nozzle hole portion is required.

<Liquid>
Liquids with excellent drying properties and low surface tension have a weak force to form meniscuses in the nozzle holes, and the meniscus is easily destroyed by dirt on the nozzle holes. It may happen. When the liquid repellent film material is provided on the inner wall of the nozzle, the liquid does not spread easily in the nozzle hole, and the meniscus can be kept well. By stabilizing the meniscus, it becomes difficult for the liquid to bend and discharge stability is improved.

  The dynamic surface tension A of the liquid is 25 mN / m or more and 35 mN / m or less at a surface lifetime of 15 msec by the maximum bubble pressure method at 25 ° C. The relationship between the dynamic surface tension A and the static surface tension B is 1.5 ≦ A When / B ≦ 2, the wettability after landing increases and the leveling property of the ink is improved. In addition, since the static surface tension B has the relationship of the above formula, the ink penetrates quickly on the paper surface, so that the ink on the paper surface is quickly absorbed on the paper surface. The method for adjusting the dynamic surface tension A and the static surface tension B of the liquid to the above ranges is not particularly limited, but examples include adjustment using an appropriate amount of a surfactant.

  The dynamic surface tension can be measured by, for example, a portable surface tension meter (manufactured by Eiko Seiki Co., Ltd., SITA DynoTester). The measurement conditions are temperature: 25 ° C. and bubblelifetime: 15 msec.

<< Ink >>
The case where the liquid to be ejected is an ink containing water, a color material, and an organic solvent will be described below. However, the liquid may contain other additives.

<Organic solvent>
The organic solvent used in the present invention is not particularly limited, and a water-soluble organic solvent can be used. Examples thereof include ethers such as polyhydric alcohols, polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines and sulfur-containing compounds.
Specific examples of the water-soluble organic solvent include, for example, ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, and 1,4-butane. Diol, 2,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol 2,4-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, 1,5-hexanediol, Glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-he Polyhydric alcohols such as sundiol, ethyl-1,2,4-butanetriol, 1,2,3-butanetriol, 2,2,4-trimethyl-1,3-pentanediol, petriol, ethylene glycol mono Polyhydric alcohol alkyl ethers such as ethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monophenyl ether, ethylene glycol mono Polyhydric alcohol aryl ethers such as benzyl ether, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl- -N-containing heterocyclic compounds such as pyrrolidone, 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, γ-butyrolactone, formamide, N-methylformamide, N, N-dimethylformamide, 3-methoxy-N, Amides such as N-dimethylpropionamide and 3-butoxy-N, N-dimethylpropionamide, amines such as monoethanolamine, diethanolamine and triethylamine, sulfur-containing compounds such as dimethylsulfoxide, sulfolane and thiodiethanol, propylene carbonate, Examples thereof include ethylene carbonate.
In addition to functioning as a wetting agent, it is preferable to use an organic solvent having a boiling point of 250 ° C. or lower because good drying properties can be obtained.

A polyol compound having 8 or more carbon atoms and a glycol ether compound are also preferably used. Specific examples of the polyol compound having 8 or more carbon atoms include 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, and the like.
Specific examples of glycol ether compounds include polyhydric alcohol alkyls such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether. Examples of ethers include polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.

  A polyol compound having 8 or more carbon atoms and a glycol ether compound can improve ink permeability when paper is used as a recording medium.

  The content of the organic solvent in the ink is not particularly limited and can be appropriately selected according to the purpose, but is preferably 10% by mass or more and 60% by mass or less from the viewpoint of the drying property and ejection reliability of the ink, 20 mass% or more and 60 mass% or less are more preferable.

<Water>
The water content in the ink is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10% by mass or more and 90% by mass or less, and 20% by mass from the viewpoint of ink drying property and ejection reliability. % To 60% by mass is more preferable.

<Color material>
The color material is not particularly limited, and pigments and dyes can be used.
An inorganic pigment or an organic pigment can be used as the pigment. These may be used alone or in combination of two or more. A mixed crystal may be used.
As the pigment, for example, a black pigment, a yellow pigment, a magenta pigment, a cyan pigment, a white pigment, a green pigment, an orange pigment, a glossy pigment such as gold or silver, a metallic pigment, or the like can be used.
Carbon black produced by known methods such as contact method, furnace method, thermal method in addition to titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, chrome yellow as inorganic pigments Can be used.
Organic pigments include azo pigments, polycyclic pigments (eg, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, and quinofullerone pigments). Dye chelates (for example, basic dye type chelates, acidic dye type chelates), nitro pigments, nitroso pigments, aniline black, and the like can be used. Of these pigments, those having good affinity with the solvent are preferably used. In addition, resin hollow particles and inorganic hollow particles can also be used.
Specific examples of pigments include black for carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, or copper, iron (CI pigment black 11). And metal pigments such as titanium oxide, and organic pigments such as aniline black (CI Pigment Black 1).
Further, for color use, C.I. I. Pigment Yellow 1, 3, 12, 13, 14, 17, 24, 34, 35, 37, 42 (yellow iron oxide), 53, 55, 74, 81, 83, 95, 97, 98, 100, 101, 104 , 108, 109, 110, 117, 120, 138, 150, 153, 155, 180, 185, 213, C.I. I. Pigment orange 5, 13, 16, 17, 36, 43, 51, C.I. I. Pigment Red 1, 2, 3, 5, 17, 22, 23, 31, 38, 48: 2, 48: 2 (Permanent Red 2B (Ca)), 48: 3, 48: 4, 49: 1, 52: 2, 53: 1, 57: 1 (Brilliant Carmine 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81, 83, 88, 101 (Bengara), 104, 105, 106, 108 ( Cadmium red), 112, 114, 122 (quinacridone magenta), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 184, 185, 190, 193, 202, 207, 208, 209, 213, 219, 224, 254, 264, C.I. I. Pigment violet 1 (rhodamine lake), 3, 5: 1, 16, 19, 23, 38, C.I. I. Pigment Blue 1, 2, 15 (phthalocyanine blue), 15: 1, 15: 2, 15: 3, 15: 4 (phthalocyanine blue), 16, 17: 1, 56, 60, 63, C.I. I. Pigment Green 1, 4, 7, 8, 10, 17, 18, 36, etc.
The dye is not particularly limited, and an acid dye, a direct dye, a reactive dye, and a basic dye can be used. One kind may be used alone, or two or more kinds may be used in combination.
Examples of the dye include C.I. I. Acid Yellow 17, 23, 42, 44, 79, 142, C.I. I. Acid Red 52, 80, 82, 249, 254, 289, C.I. I. Acid Blue 9, 45, 249, C.I. I. Acid Black 1, 2, 24, 94, C.I. I. Food Black 1, 2, C.I. I. Direct Yellow 1,12,24,33,50,55,58,86,132,142,144,173, C.I. I. Direct Red 1,4,9,80,81,225,227, C.I. I. Direct Blue 1, 2, 15, 71, 86, 87, 98, 165, 199, 202, C.I. I. Directed Black 19, 38, 51, 71, 154, 168, 171, 195, C.I. I. Reactive Red 14, 32, 55, 79, 249, C.I. I. Reactive black 3, 4, and 35 are mentioned.

  The content of the color material in the ink is preferably 0.1% by mass or more and 15% by mass or less, more preferably 1% by mass or more and 10% by mass from the viewpoints of improvement in image density, good fixability and ejection stability. It is as follows.

In order to disperse the pigment in the ink, a method of introducing a hydrophilic functional group into the pigment to form a self-dispersing pigment, a method of dispersing the pigment surface by coating with a resin, a method of dispersing using a dispersant, Etc.
Examples of a method for introducing a hydrophilic functional group into a pigment to form a self-dispersing pigment include a self-dispersing pigment that can be dispersed in water by adding a functional group such as a sulfone group or a carboxyl group to the pigment (for example, carbon). Can be used.
As a method for coating the surface of the pigment with a resin and dispersing it, a method in which the pigment is included in microcapsules and can be dispersed in water can be used. This can be paraphrased as a resin-coated pigment. In this case, it is not necessary that all pigments blended in the ink are coated with a resin, and within a range where the effects of the present invention are not impaired, uncoated pigments and partially coated pigments are dispersed in the ink. It may be.
Examples of the method of dispersing using a dispersant include a method of dispersing using a known low-molecular type dispersant or high-molecular type dispersant represented by a surfactant.
As the dispersant, for example, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant, or the like can be used depending on the pigment.
RT-100 (nonionic surfactant) manufactured by Takemoto Oil & Fat Co., Ltd. and naphthalenesulfonic acid Na formalin condensate can also be suitably used as a dispersant.
The said dispersing agent may be used individually by 1 type, or may use 2 or more types together.

<Resin>
The type of resin contained in the ink is not particularly limited and can be appropriately selected according to the purpose. For example, urethane resin, polyester resin, acrylic resin, vinyl acetate resin, styrene resin, butadiene type Examples thereof include resins, styrene-butadiene resins, vinyl chloride resins, acrylic styrene resins, and acrylic silicone resins.
You may use the resin particle which consists of these resin. An ink can be obtained by mixing resin particles with a material such as a colorant or an organic solvent in a resin emulsion state in which water is dispersed as a dispersion medium. As said resin particle, what was synthesize | combined suitably may be used and a commercial item may be used. Moreover, these may be used individually by 1 type, or may be used in combination of 2 or more types of resin particles.

Among these, resin particles having a total HSP (Hansen solubility parameter) value of 20 [(J / cm ³ ) ^0.5 ] or more and 24.9 [(J / cm ³ ) ^0.5 ] or less are preferable. The reason for this is that when the total HSP value is 20 [(J / cm ³ ) ^0.5 ] or more and 24.9 [(J / cm ³ ) ^0.5 ] or less, the meniscus in the nozzle is left in a state of being easily dried. Even after being applied, the adhesion of the resin particles to the liquid repellent film in this embodiment was suppressed. This means that even a head that has been left uncapped for a certain period of time can be ejected normally.

As the resin particles, those appropriately synthesized or commercial products may be used, but the total HSP value is 20 [(J / cm ³ ) ^0.5 ] or more and 24.9 [(J / Cm ³ ) ^0.5 ] Examples of commercially available products include Takelac WS-4000, W-6010, W-6110, W-6061, W-5661, and W-6010 manufactured by Mitsui Chemicals, Inc. .

  The HSP value is a Hansen solubility parameter and is an index representing the solubility of a substance. The HSP value is different from the Hilde brand SP value used in the solvent handbook (published by Kodansha Scientific Co., Ltd.), and has a multi-dimensional (typically three-dimensional) solubility profile. Represented by This vector can typically be expressed by a dispersion term, a polar term, and a hydrogen bond term, where the dispersion term is van der Waals force, the polar term is a dipole moment, the hydrogen bond term is caused by water, alcohol, etc. Is reflected. The total HSP value is the above three vector sum. The HSP value can be calculated by software such as HSPiP.

  The total HSP value of the resin particles can be calculated from the solubility determined experimentally. Resin swelling test is performed using more than ten kinds of solvents with known HSP values. The swelling test is performed by, for example, pouring a resin emulsion liquid in which resin particles are dispersed into a Teflon (registered trademark) container and drying it at 50 ° C. for 3 hours. The rate of increase in mass when immersed for a period of time is evaluated. Then, the result of obtaining the solubility for each solvent is input to software such as HSPiP, whereby the HSP value of the target resin can be calculated.

  The glass transition point (Tg) of the resin particles is preferably -30 ° C or higher and 30 ° C or lower. For this reason, film formation at room temperature is possible when the temperature is 30 ° C. or lower, and blocking can be prevented because the film is formed quickly on paper. Furthermore, the resin having a low glass transition point (Tg) has a problem that the resin easily adheres to the inner wall of the nozzle and may cause the meniscus to be broken. However, in this embodiment, the liquid repellent film is provided to the inner wall of the nozzle. If it is -30 degreeC or more, a meniscus can be formed, without adhering to a liquid-repellent film.

  The glass transition point (Tg) of the resin particles can be measured by, for example, a high sensitivity differential scanning calorimeter (manufactured by Rigaku Corporation, Thermo plus EVO2 DSC8231). Specifically, the reference sample and the measurement sample are put in the apparatus, and the change in thermal energy is quantified from the temperature difference between the two samples when the temperature is raised from -70 ° C to 140 ° C at 10 ° C / min. It is a method of specifying Tg by measuring automatically.

<Additives>
If necessary, a surfactant, an antifoaming agent, an antiseptic / antifungal agent, a rust inhibitor, a pH adjuster, and the like may be added to the ink.

-Surfactant-
The surfactant preferably contains a polyether-modified siloxane compound. By using the polyether-modified siloxane compound as a surfactant, the ink becomes difficult to get wet with the liquid repellent film of the nozzle plate of the ink discharge head, and discharge failure due to ink nozzle adhesion is prevented and discharge stability is improved.

  As the polyether-modified siloxane compound, from the following general formula (III), the dispersion stability is not impaired by the combination of the colorant and the organic solvent, the dynamic surface tension is low, the penetrability and the leveling property are ( VI) is preferably at least one selected from the compounds represented by VI).

[General Formula (III)]
However, in general formula (III), m shows the integer of 0-23 and n shows the integer of 1-10. a represents an integer of 1 to 23, and b represents an integer of 0 to 23. R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[General Formula (IV)]
However, in general formula (IV), m shows the integer of 1-8, c and d show the integer of 1-10. R ₂ and R ₃ represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[General Formula (V)]
However, in the general formula (V), e represents an integer from 1 to 8, _{R 4} represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[General Formula (VI)]
However, in general formula (VI), f shows the integer of 1-8. R ₅ represents a polyether group represented by the following general formula (VI-1).

However, in general formula (VI-1), g shows the integer of 0-23, h shows the integer of 0-23, and g and h do not become 0 simultaneously. R ₆ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

  Examples of the polyether-modified siloxane compound represented by the general formula (III) include, but are not limited to, compounds represented by the following structural formula.

[Structural Formula (XII)]

[Structural Formula (XIII)]

  Examples of the polyether-modified siloxane compound represented by the general formula (IV) include, but are not limited to, compounds represented by the following structural formula.

[Structural Formula (XIV)]

  Examples of the polyether-modified siloxane compound represented by the general formula (V) include, but are not limited to, compounds represented by the following structural formula.

[Structural Formula (XV)]

  Examples of the polyether-modified siloxane compound represented by the general formula (VI) include, but are not limited to, compounds represented by the following structural formula.

[Structural Formula (XVI)]

[Structural Formula (XVII)]

[Structural Formula (XVIII)]

  As said polyether modified siloxane compound, what was synthesize | combined suitably may be used and a commercial item may be used.

The method for synthesizing the polyether-modified siloxane compound is not particularly limited and may be appropriately selected depending on the intended purpose. For example, Patent Nos. 5101598, 5032325, 5661229, etc. Can be referred to.
Specifically, it can be synthesized by hydrosilylation reaction between (A) polyether and (B) organohydrogensiloxane.
(A) the polyether _{component, - (C n H 2n O} ) - ( wherein, n is 2-4.) Shows a polyoxyalkylene polymer represented by.
The polyoxyalkylene copolymer unit is preferably an oxyethylene unit-(C ₂ H ₄ O)-, an oxypropylene unit-(C ₃ H ₆ O)-, an oxybutylene unit-(C ₄ H ₈ O)-, Alternatively, mixed units thereof can be included. The oxyalkylene units may be arranged in any way and can form either block or random copolymer structures, but preferably form random copolymer groups. More preferably, the polyoxyalkylene contains both oxyethylene units (C ₂ H ₄ O) and oxypropylene units (C ₃ H ₆ O) in the random copolymer.

The organohydrogensiloxane of component (B) is an organopolysiloxane containing at least one silicon-bonded hydrogen (SiH) per molecule. Examples of the organopolysiloxane include (R ₃ SiO _0.5 ), (R ₂ SiO), (RSiO _1.5 ), (SiO ₂ ) (wherein, R is independently an organic group or hydrocarbon) And any number or combination of siloxy units).
When R of the organopolysiloxane (R ₃ SiO _0.5 ), (R ₂ SiO), (RSiO _1.5 ) is a methyl group, the siloxy units are represented as M, D, and T units, respectively. Whereas (SiO ₂ ) siloxy units are shown as Q units.
Organohydrogensiloxanes have a similar structure but have at least one SiH present on the siloxy units.
Methyl-based siloxy units in the organohydrogensiloxane, ^{"M H"} siloxy units _(R 2 _{HSiO 0.5),} ^{"D H"} siloxy units (RHSiO), ^{"T H"} siloxy units _{(HSiO 1.5)} It can be expressed as including.
The organohydrogensiloxane can include any number of M, M ^H , D, D ^H , T, T ^H , or Q siloxy units, provided that at least one siloxy unit includes SiH.

The component (A) and the component (B) are reacted by a hydrosilylation reaction. The hydrosilylation reaction is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably performed by adding a hydrosilylation catalyst.
There is no restriction | limiting in particular as a hydrosilylation catalyst, According to the objective, it can select suitably, For example, platinum, rhodium, ruthenium, palladium, osmium, or iridium metal, those organometallic compounds, or those combinations etc. Is mentioned.
The content of the hydrosilylation catalyst is preferably from 0.1 ppm to 1,000 ppm, more preferably from 1 ppm to 100 ppm, based on the weight of the component (A) and the component (B).

The hydrosilylation reaction can be performed without dilution or in the presence of a solvent, but is preferably performed in the presence of a solvent.
Examples of the solvent include alcohols (eg, methanol, ethanol, isopropanol, butanol, or n-propanol), ketones (eg, acetone, methyl ethyl ketone, or methyl isobutyl ketone); aromatic hydrocarbons (eg, benzene, toluene, or Xylene); aliphatic hydrocarbons (eg, heptane, hexane, or octane); glycol ethers (eg, propylene glycol methyl ether, dipropylene glycol methyl ether, propylene glycol n-butyl ether, propylene glycol n-propyl ether, or ethylene glycol) n-butyl ether), halogenated hydrocarbons (for example, dichloromethane, 1,1,1-trichloroethane, or methylene chloride, chloroform), dimethyl Sulfoxide, dimethylformamide, acetonitrile, tetrahydrofuran, gasoline, mineral spirits, or naphtha, and the like. These may be used individually by 1 type and may use 2 or more types together.

The amount of the component (A) and the component (B) used in the hydrosilylation reaction is not particularly limited and can be appropriately adjusted according to the purpose. The total unsaturated group in the component (A) and ( It is represented by the molar ratio with the SiH content of the component B). It is preferable to use a polyether unsaturated group amount of 20 mol% or less, more preferably 10 mol% or less of the polyether unsaturated group amount, relative to the SiH molar amount of the organohydrogensiloxane. .
The hydrosilylation reaction is not particularly limited, and can be performed in any known batch method, semi-continuous method, or continuous method. For example, the hydrosilylation reaction can be performed in a continuous method using a plug flow reactor.

Commercially available polyether-modified siloxane compounds include, for example, 71ADDITIVE, 74ADDITIVE, 57ADDITIVE, 8029ADDITIVE, 8054ADDITIVE, 8211ADDITIVE, 8019ADDITIVE, 8526ADDITIVE, FZ-2123, FZ-2191 (all manufactured by TORAY Dow Corning 44; , TSF4441, TSF4445, TSF4446, TSF4450, TSF4452, TSF4460 (all manufactured by Momentive Performance Materials); Silface SAG002, Silface SAG003, Silface SAG005, Silface SAG503A, Silface SAG008, Silface SJM003 ( All are manufactured by Nissin Chemical Industry Co., Ltd.); TEGO Wet KL245, TEGO Wet 250, TEGO Wet 260, TEGO Wet 265, TEGO Wet 270, TEGO Wet 280 (all manufactured by Evonik); BYK-345, BYK- 347, BYK-348, BYK-375, BYK-377 (all are manufactured by Big Chemie Japan). These may be used individually by 1 type and may use 2 or more types together.
Among these, TEGO Wet 270 (manufactured by Evonik) and Silface SAG503A (manufactured by Nissin Chemical Industry Co., Ltd.) are preferable.

  As the surfactant, in addition to the polyether-modified siloxane compound, a fluorine-based surfactant, a silicone-based surfactant, an acetylene glycol or an acetylene alcohol-based surfactant may be used in combination.

<Antifoaming agent>
There is no restriction | limiting in particular as an antifoamer, For example, a silicone type antifoamer, a polyether type | system | group antifoamer, a fatty-acid ester type | system | group antifoamer etc. are mentioned. These may be used alone or in combination of two or more. Among these, a silicone type antifoaming agent is preferable from the viewpoint of excellent foam breaking effect.

<Antiseptic and antifungal agent>
The antiseptic / antifungal agent is not particularly limited, and examples thereof include 1,2-benzisothiazolin-3-one.

<Rust preventive>
There is no restriction | limiting in particular as a rust preventive agent, For example, acidic sulfite, sodium thiosulfate, etc. are mentioned.

<PH adjuster>
The pH adjuster is not particularly limited as long as the pH can be adjusted to 7 or more, and examples thereof include amines such as diethanolamine and triethanolamine.

  The solid content of the ink is preferably 1% by mass or more and 13% by mass or less. When the solid content is 13% by mass or less, sticking to the nozzle hole is less likely to occur, and good dischargeability is obtained.

The average particle size of the solid content of the ink is preferably ₅₀ nm to 200 nm in terms of a cumulative 50% particle size (D ₅₀ ). When the cumulative 50% particle size (D ₅₀ ) is 80 nm or more, particles are likely to remain on the surface to be printed, and density unevenness is reduced. In addition, when the cumulative 50% particle size is 200 nm or less, nozzle clogging due to solid content is less likely to occur. The average particle size of the solid content of the ink can be measured using, for example, a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrack Bell Co., Ltd.).

  The viscosity at 25 ° C. of the ink is preferably 5 mPa · s or more and 30 mPa · s or less, preferably 5 mPa · s or more and 25 mPa · s or less from the viewpoint of improving the printing density and character quality and obtaining good discharge properties. More preferred. Here, for the viscosity, for example, a rotary viscometer (manufactured by Toki Sangyo Co., Ltd., RE-80L) can be used. Measurement conditions are 25 ° C., standard cone rotor (1 ° 34 ′ × R24), sample liquid amount 1.2 mL, rotation speed 50 rpm, and measurement is possible for 3 minutes.

  When the water in the ink evaporates, the viscosity may increase due to an increase in the solid content in the ink. If the thickening rate is high, the nozzle holes are likely to be clogged with the thickened ink, which causes discharge abnormality. In order to maintain good discharge, the viscosity increase rate represented by the following formula (5) is preferably 600% or less and more preferably 400% or less when 30% by mass of water is evaporated.

  The pH of the ink is preferably 7 to 12 and more preferably 8 to 11 from the viewpoint of preventing corrosion of the metal member in contact with the liquid.

<Recording medium>
The recording medium used for recording is not particularly limited, and examples thereof include plain paper, glossy paper, special paper, cloth, film, OHP sheet, and general-purpose printing paper.

<Recorded material>
The ink recorded matter of the present invention has an image formed using the ink of the present invention on a recording medium. Recording can be performed by recording with an inkjet recording apparatus and an inkjet recording method.

<Liquid discharge head>
The apparatus for ejecting liquid according to the present embodiment includes a liquid ejection head having a nozzle plate and further having other members as necessary.

<< Other parts >>
There is no restriction | limiting in particular as another member, According to the objective, it can select suitably, For example, a pressurization chamber, a stimulus generation means, etc. are mentioned.

-Pressure chamber-
The pressurizing chamber is a plurality of individual flow paths that are individually arranged corresponding to the plurality of nozzle holes provided in the nozzle plate and communicate with the nozzle holes. The ink flow path, the pressurized liquid chamber, the pressure chamber, and the discharge It may also be called a chamber or a liquid chamber.

-Stimulus generation means-
The stimulus generation means is means for generating a stimulus to be applied to the ink.
There is no restriction | limiting in particular as a stimulus in a stimulus generation means, According to the objective, it can select suitably, For example, heat | fever (temperature), a pressure, a vibration, light, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, heat and pressure are preferable.
Examples of the stimulus generating means include a heating device, a pressurizing device, a piezoelectric element, a vibration generating device, an ultrasonic oscillator, and a light. Specifically, the stimulus generating means includes a piezoelectric actuator such as a piezoelectric element, a thermal actuator that uses a phase change caused by ink film boiling using an electrothermal transducer such as a heating resistor, and a metal phase change caused by a temperature change. Examples thereof include a shape memory alloy actuator to be used and an electrostatic actuator using an electrostatic force.

When the stimulus is “heat”, thermal energy corresponding to the recording signal is applied to the ink in the ink ejection head using, for example, a thermal head. Examples include a method in which bubbles are generated in ink by thermal energy, and ink is ejected as droplets from the nozzle holes of the nozzle plate by the pressure of the bubbles.
When the stimulus is “pressure”, for example, the piezoelectric element is bent by applying a voltage to a piezoelectric element bonded to a position called a pressure chamber in the ink flow path in the ink discharge head. As a result, the volume of the pressure chamber shrinks, and a method of ejecting ink as droplets from the nozzle holes of the ink ejection head can be used.
Among these, a piezo method in which a voltage is applied to the piezo element to fly ink is preferable.

  Here, an example of the liquid discharge head used in the present embodiment will be described with reference to FIGS. 8 is an explanatory perspective view of the appearance of the head, FIG. 9 is a cross-sectional explanatory view in the direction (liquid chamber longitudinal direction) perpendicular to the nozzle arrangement direction along the line AA in FIG. 8, and FIG. It is sectional explanatory drawing of the nozzle arrangement | sequence direction (liquid chamber short direction) in alignment with a line.

  In the liquid discharge head, the nozzle plate 1 according to the present embodiment, the flow path plate 2 and the vibration plate member 3 as a wall surface member are laminated and joined. The liquid discharge head includes a piezoelectric actuator 14 that displaces the diaphragm member 3 and a frame member 16 as a common flow path member.

  The nozzle plate 1, the flow channel plate 2, and the vibration plate member 3 form an individual flow channel through which a plurality of nozzles 11 that discharge droplets communicate. When the individual flow path is the downstream side of the nozzle 11, the individual liquid chamber 6 that communicates with the nozzle 11 from the downstream side, the fluid resistance portion 7 that supplies the liquid to the individual liquid chamber 6, and the liquid that communicates with the fluid resistance portion 7. It is comprised with the introduction part 8. FIG.

  Then, the liquid is introduced into the individual flow path from the common liquid chamber 10 as the common flow path of the frame member 16 through the introduction port portion (supply port) 9 formed in the diaphragm member 3, and the liquid introduction portion 8, the fluid resistance portion Through 7, the liquid is supplied to the individual liquid chamber 6. Note that a filter may be provided in the introduction port 9.

  Here, the nozzle plate 1 is the nozzle plate according to the above-described embodiment, and a liquid repellent film is provided on the liquid discharge surface.

  The flow path plate 2 etches the SUS substrate to form through portions that form the individual flow paths 5 such as the individual liquid chamber 6, the fluid resistance section 7, and the liquid introduction section 8.

  The diaphragm member 3 is a wall surface member that forms the wall surface of the individual liquid chamber 6 of the flow path plate 2. The diaphragm member 3 has a three-layer structure, and when the flow path plate 2 side is a first layer, a deformable vibration region (vibration plate) 31 is formed in a portion corresponding to the individual liquid chamber 6 in the first layer. ing.

  The diaphragm member 3 is formed from a nickel (Ni) metal plate and is manufactured by an electroforming method (electroforming). Not limited to this, other metal members, resin members, laminated members of resin layers and metal layers, and the like can be used.

  The piezoelectric actuator 14 includes an electromechanical conversion element as a driving means (actuator means, pressure generating means) for deforming the vibration region 31 of the diaphragm member 3 on the opposite side of the diaphragm member 3 from the individual liquid chamber 6. Is arranged.

  This piezoelectric actuator 14 has a plurality of laminated piezoelectric members 12 bonded with adhesive on a base member 13, and the piezoelectric member 12 is grooved by half-cut dicing so that a required number of piezoelectric members 12 is provided. Piezoelectric columns 12A and 12B are formed in a comb shape at a predetermined interval.

  The piezoelectric columns 12A and 12B of the piezoelectric member 12 are the same, but a piezoelectric column that is driven by giving a driving waveform is a driving piezoelectric column (driving column) 12A, and a piezoelectric column that is used as a simple column without giving a driving waveform. It is distinguished as a non-driving piezoelectric column (non-driving column) 12B.

  Then, the drive column 12A is joined to a convex portion 31a which is an island-shaped thick portion formed in the vibration region 31 of the diaphragm member 3. Further, the non-driving column 12 </ b> B is joined to the convex portion 31 b which is a thick portion of the diaphragm member 3.

  This piezoelectric member 12 is formed by alternately laminating piezoelectric layers and internal electrodes, and each internal electrode is pulled out to the end face to be provided with an external electrode, and can be used to supply a drive signal to the external electrode of the drive column 12A. An FPC 15 as a flexible wiring board having flexibility is connected.

  The frame member 16 is formed by injection molding with, for example, epoxy resin or polyphenylene sulfite, which is a thermoplastic resin, and a common liquid chamber 10 is formed in which liquid is supplied from a head tank or a liquid cartridge.

  In the liquid discharge head configured as described above, for example, the drive column 12A contracts by lowering the voltage applied to the drive column 12A from the reference potential, the vibration region 31 of the diaphragm member 3 descends, and the individual liquid chamber 6 As the volume expands, the liquid flows into the individual liquid chamber 6.

  Thereafter, the voltage applied to the drive column 12A is increased to extend the drive column 12A in the stacking direction, and the vibration region 31 of the vibration plate member 3 is deformed in the direction of the nozzle 11 to contract the volume of the individual liquid chamber 6. The liquid in the individual liquid chamber 6 is pressurized, and droplets are ejected (jetted) from the nozzle 11.

  Then, by returning the voltage applied to the drive column 12A to the reference potential, the vibration region 31 of the diaphragm member 3 is restored to the initial position, and the individual liquid chamber 6 expands to generate a negative pressure. The liquid is filled into the individual liquid chamber 6 from the liquid chamber 10. Therefore, after the vibration of the meniscus surface of the nozzle 11 is attenuated and stabilized, the operation proceeds to the next droplet discharge.

  Note that the driving method of the head is not limited to the above example (pulling-pushing), and it is also possible to perform striking or pushing depending on the direction to which the driving waveform is given.

  As described above, since the liquid ejection head includes the nozzle plate according to the present invention, it is possible to perform stable droplet ejection with little variation in droplet ejection characteristics.

  Next, an example of an apparatus for discharging a liquid according to the present invention will be described with reference to FIGS. FIG. 11 is an explanatory plan view of the main part of the apparatus, and FIG. 12 is an explanatory side view of the main part of the apparatus.

  This apparatus is a serial type apparatus, and the carriage 403 reciprocates in the main scanning direction by the main scanning moving mechanism 493. The main scanning movement mechanism 493 includes a guide member 401, a main scanning motor 405, a timing belt 408, and the like. The guide member 401 spans the left and right side plates 491A and 491B and holds the carriage 403 so as to be movable. The carriage 403 is reciprocated in the main scanning direction by the main scanning motor 405 via the timing belt 408 spanned between the driving pulley 406 and the driven pulley 407.

  A liquid discharge unit 440 in which a liquid discharge head 404 including a nozzle plate used in this embodiment and a head tank 441 are integrated is mounted on the carriage 403.

  The liquid discharge head 404 of the liquid discharge unit 440 discharges, for example, yellow (Y), cyan (C), magenta (M), and black (K) liquids. The liquid ejection head 404 is mounted with a nozzle row composed of a plurality of nozzles arranged in the sub-scanning direction orthogonal to the main scanning direction, and the ejection direction facing downward.

  The liquid stored in the liquid cartridge 450 is supplied to the head tank 441 by the supply mechanism 494 for supplying the liquid stored outside the liquid discharge head 404 to the liquid discharge head 404.

  The supply mechanism 494 includes a cartridge holder 451 that is a filling unit for mounting the liquid cartridge 450, a tube 456, a liquid feeding unit 452 including a liquid feeding pump, and the like. The liquid cartridge 450 is detachably attached to the cartridge holder 451. Liquid is fed from the liquid cartridge 450 to the head tank 441 by the liquid feeding unit 452 via the tube 456.

  This apparatus includes a transport mechanism 495 for transporting the paper 410. The transport mechanism 495 includes a transport belt 412 serving as transport means, and a sub-scanning motor 416 for driving the transport belt 412.

  The conveyance belt 412 adsorbs the paper 410 and conveys it at a position facing the liquid ejection head 404. The transport belt 412 is an endless belt and is stretched between the transport roller 413 and the tension roller 414. The adsorption can be performed by electrostatic adsorption or air suction.

  The transport belt 412 rotates in the sub-scanning direction when the transport roller 413 is rotationally driven by the sub-scanning motor 416 via the timing belt 417 and the timing pulley 418.

  Further, on one side of the carriage 403 in the main scanning direction, a maintenance / recovery mechanism 420 that performs maintenance / recovery of the liquid ejection head 404 is disposed on the side of the transport belt 412.

  The maintenance / recovery mechanism 420 includes, for example, a cap member 421 for capping the nozzle surface (surface on which the nozzle is formed) of the liquid ejection head 404, a wiper member 422 for wiping the nozzle surface, and the like.

  The main scanning movement mechanism 493, the supply mechanism 494, the maintenance / recovery mechanism 420, and the transport mechanism 495 are attached to a housing including the side plates 491A and 491B and the back plate 491C.

  In this apparatus configured as described above, the paper 410 is fed and sucked onto the transport belt 412, and the paper 410 is transported in the sub-scanning direction by the circular movement of the transport belt 412.

  Therefore, the liquid ejection head 404 is driven in accordance with the image signal while moving the carriage 403 in the main scanning direction, thereby ejecting liquid onto the stopped paper 410 to form an image.

  Thus, since this apparatus includes the liquid discharge head used in the present invention, a high-quality image can be stably formed.

  Next, another example of the liquid discharge unit used in the present invention will be described with reference to FIG. FIG. 13 is an explanatory plan view of the main part of the unit.

  The liquid discharge unit includes a casing portion composed of side plates 491A and 491B and a back plate 491C, a main scanning movement mechanism 493, a carriage 403, and a liquid discharge portion among members constituting a liquid discharge device. The head 404 is configured.

  Note that a liquid discharge unit in which at least one of the above-described maintenance and recovery mechanism 420 and the supply mechanism 494 is further attached to, for example, the side plate 491B of the liquid discharge unit may be configured.

  Next, still another example of the liquid discharge unit according to the present invention will be described with reference to FIG. FIG. 14 is an explanatory front view of the unit.

  This liquid discharge unit includes a liquid discharge head 404 to which a flow path component 444 is attached, and a tube 456 connected to the flow path component 444.

  The flow path component 444 is disposed inside the cover 442. A head tank 441 may be included instead of the flow path component 444. In addition, a connector 443 that is electrically connected to the liquid ejection head 404 is provided above the flow path component 444.

  In the present embodiment, “an apparatus that discharges liquid” is an apparatus that includes a liquid discharge head or a liquid discharge unit and drives the liquid discharge head to discharge liquid. The apparatus for ejecting liquid includes not only an apparatus capable of ejecting liquid to an object to which liquid can adhere, but also an apparatus for ejecting liquid toward the air or liquid.

  This “apparatus for discharging liquid” may include means for feeding, transporting, and discharging a liquid to which liquid can adhere, as well as a pre-processing apparatus and a post-processing apparatus.

  For example, as a “liquid ejecting device”, an image forming device that forms an image on paper by ejecting ink, a powder is formed in layers to form a three-dimensional model (three-dimensional model) There is a three-dimensional modeling apparatus (three-dimensional modeling apparatus) that discharges a modeling liquid onto the powder layer.

  Further, the “apparatus for ejecting liquid” is not limited to an apparatus in which significant images such as characters and figures are visualized by the ejected liquid. For example, what forms a pattern etc. which does not have a meaning in itself, and what forms a three-dimensional image are also included.

  The above-mentioned “thing to which liquid can adhere” means that liquid can adhere even temporarily. The material to which “the liquid adheres” may be any material as long as the liquid can temporarily adhere, such as paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics.

  “Liquid” also includes ink, treatment liquid, DNA sample, resist, pattern material, binder, modeling liquid, and the like.

  Further, the “device for ejecting liquid” includes both a serial type device that moves the liquid ejection head and a line type device that does not move the liquid ejection head, unless otherwise specified.

  In addition to the “device for discharging liquid”, a processing liquid coating apparatus for discharging a processing liquid onto a sheet for applying a processing liquid to the surface of the sheet for the purpose of modifying the surface of the sheet, or a raw material There is an injection granulator for granulating raw material fine particles by spraying a composition liquid dispersed in a solution through a nozzle.

  A “liquid ejection unit” is a unit in which functional parts and mechanisms are integrated with a liquid ejection head, and is an assembly of parts related to liquid ejection. For example, the “liquid discharge unit” includes a combination of at least one of a head tank, a carriage, a supply mechanism, a maintenance / recovery mechanism, and a main scanning movement mechanism with a liquid discharge head.

  Here, the term “integrated” refers to, for example, a liquid discharge head, a functional component, and a mechanism that are fixed to each other by fastening, adhesion, engagement, etc., and one that is held movably with respect to the other. Including. Further, the liquid discharge head, the functional component, and the mechanism may be configured to be detachable from each other.

  For example, there is a liquid discharge unit in which a liquid discharge head and a head tank are integrated, such as the liquid discharge unit 440 shown in FIG. Also, there are some in which the liquid discharge head and the head tank are integrated by being connected to each other by a tube or the like. Here, a unit including a filter may be added between the head tank and the liquid discharge head of these liquid discharge units.

  In addition, there is a liquid discharge unit in which a liquid discharge head and a carriage are integrated.

  In addition, there is a liquid discharge unit in which the liquid discharge head and the scanning movement mechanism are integrated by holding the liquid discharge head movably on a guide member that constitutes a part of the scanning movement mechanism. Further, as shown in FIG. 13, there is a liquid discharge unit in which a liquid discharge head, a carriage, and a main scanning movement mechanism are integrated.

  Also, there is a liquid discharge unit in which a cap member that is a part of the maintenance / recovery mechanism is fixed to a carriage to which the liquid discharge head is attached, and the liquid discharge head, the carriage, and the maintenance / recovery mechanism are integrated. .

  Further, as shown in FIG. 14, as a liquid discharge unit, there is a unit in which a liquid discharge head and a supply mechanism are integrated by connecting a tube to a liquid discharge head to which a head tank or a flow path component is attached. .

  The main scanning movement mechanism includes a guide member alone. The supply mechanism includes a single tube and a single loading unit.

  The “liquid discharge head” is not limited to the pressure generating means to be used. For example, in addition to the piezoelectric actuator as described in the above embodiment (a multilayer piezoelectric element may be used), a thermal actuator using an electrothermal conversion element such as a heating resistor, a diaphragm and a counter electrode are included. An electrostatic actuator or the like may be used.

  In addition, the terms “image formation”, “recording”, “printing”, “printing”, “printing”, “modeling”, etc. in the terms of the present embodiment are all synonymous.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to the following Example. In addition, the symbol of the wave dash "-" used in order to show a range in an Example shall include the value described before and behind it, unless it designates especially.

Example 1
<Preparation of nozzle plate>
-Preparation of nozzle substrate-
A metal flat plate member made of SUS316L having a length of 30 mm, a width of 15 mm, and a thickness of 0.05 mm was punched by punching from the opposite side of the liquid discharge surface. The punch used for drilling had a cylindrical tip portion with a length of 10 μm and a diameter of 20 μm. The burrs generated on the liquid ejection surface side were removed by polishing. Thereby, the diameter of the cylindrical portion 21a on the liquid discharge surface side shown in FIG. 2 is 20 μm, the diameter of the opening of the truncated cone-shaped portion 21b on the surface opposite to the liquid discharge surface is 40 μm, and the height of the cylindrical portion 21a is As a result, a nozzle substrate 20 having 384 nozzle holes 21 each having a size of 10 μm was obtained.

Next, as the intermediate layer 30, a SiO ₂ film 31 is formed on the surface of the nozzle substrate 20 by sputtering, and a tape 60 is attached to the surface opposite to the liquid discharge surface, and then the SiO ₂ film 31 is formed on the surface of the SiO ₂ film 31. A layer 32 of a silane coupling agent (3-aminopropyltriethoxysilane, KBE-903 (manufactured by Shin-Etsu Chemical Co., Ltd.)) was formed by spin coating.

-Formation of liquid repellent film-
Tetrafluoroethylene perfluorodioxole copolymer (Teflon (registered trademark) AF2400, manufactured by DuPont) is applied to the liquid ejection surface side of the nozzle substrate 20 at 1.5 × 10 ⁻³ Pa to 8.0 × 10 ^−3. Heating was performed at 350 ° C. to 420 ° C. under a high vacuum of Pa, and vacuum deposition was performed until the average thickness of the deposited film reached about 1 μm to 3 μm at the portion facing the deposition source. The obtained deposited film is baked at a temperature (320 ° C.) equal to or higher than the glass transition point (Tg) of the fluororesin for 5 to 60 minutes to form a fluororesin film that becomes a dense and smooth surface of the liquid repellent film 40. did. The average film thickness of the surface side surface used as the liquid ejection surface of the liquid repellent film was 2.0 μm. The average film thickness was measured by cross-sectional SEM observation (JSM-7001F, manufactured by JEOL Ltd.). As shown in FIG. 2, the obtained nozzle plate has a slope region that is inclined in the direction in which the film thickness decreases toward the edge of the nozzle at the outer peripheral portion of the nozzle. The liquid repellent film 40 was also formed on the inner wall surface of the nozzle hole 21. Here, the film thickness t2 of the liquid repellent film 40b on the inner wall surface of the nozzle 11 (corresponding to the wall surface of the nozzle hole 21 of the nozzle base material 20) is 1/10 of the film thickness t1 of the region 42 of the liquid repellent film 40a. It was below (t2 / t1 ≦ 0.1).

<Preparation of ink>
-Adjustment of pigment dispersion-
-Preparation of cyan pigment dispersion-
C.I. as a cyan pigment I. Pigment Blue 15: 3 was subjected to low-temperature plasma treatment to produce a yellow pigment having a carboxylic acid group introduced. A dispersion of this in ion exchange water was desalted and concentrated with an ultrafiltration membrane to obtain a cyan pigment dispersion of Preparation Example 1 having a pigment concentration of 15% by mass.

-Ink adjustment-
Prepare the ink used in Example 1 by adding each material to the cyan pigment dispersion liquid of Preparation Example 1 to the stirring device and filtering with a 1.0 μm polypropylene filter after stirring so as to have the composition shown in Table 2-1. did. In addition, the numerical value of the compounding quantity in Table 2-1 and Table 2-2 is "mass%".

(Examples 2 to 15)
<Preparation of nozzle plate>
The nozzle plate used in Example 2 was prepared by changing the liquid repellent film material, the manufacturing method, and the baking temperature of the nozzle plate used in Example 1 as shown in Table 1. In Examples 3 to 15, the same nozzle plate as that used in Example 1 was used. For the nozzle plate used in Example 2, as in Example 1, the presence / absence of a liquid repellent film on the inner wall surface of the nozzle and the presence / absence of a slope region were confirmed, and t2 / t1 was measured.

<Preparation of ink>
Inks used in Examples 2 to 15 were prepared in the same manner as in Example 1 except that the composition of the ink used in Example 1 was changed to the composition shown in Table 2-1 or Table 2-2. The ink used in Examples 2 to 15 includes the same ink as that used in Example 1 or other examples.

(Comparative Example 1)
<Preparation of nozzle plate>
2 parts by mass of tetrafluoroethylene perfluorodioxole copolymer (Teflon (registered trademark) AF2400, manufactured by DuPont) and 98 parts by mass of a fluorinated solvent (FC-75, manufactured by Sumitomo 3M Co., Ltd.) are mixed and dissolved to obtain a resin solution. Was made. The resin solution is spin-coated on the surface of a polyimide film (upilex (registered trademark) S, manufactured by Ube Industries, Ltd.) having a length of 30 mm, a width of 15 mm, and a thickness of 0.05 mm previously cleaned with ultrasonic waves. ^The coating was carried out under conditions of ^st · 5,000 rpm / 5 seconds, 2 ^nd · 1,500 rpm / 20 seconds, naturally dried for 30 minutes, and baked at 320 ° C. to form a liquid repellent film. From the back surface of the polyimide film, a nozzle plate in which 384 nozzle holes having a diameter of 20 μm in diameter of the cylindrical portion 21a on the surface side on the liquid discharge side were formed by a KrF excimer laser.

<Preparation of ink>
As shown in Table 2-1, the same ink as in Example 1 was used.

(Comparative Example 2)
<Preparation of nozzle plate>
By reducing the pressure of the fluorine-containing acrylate ester polymer solution (OPTOOL DSX stock solution, manufactured by Daikin Industries, Ltd.) to 10 ⁻¹ Pa with a rotary pump and gradually increasing the temperature from room temperature (25 ° C.) to about 450 ° C. Then, vapor deposition was performed on the nozzle base material 20 on which the SiO ₂ film was formed until the thickness of the vapor deposition film reached about 20 nm at a portion facing the vapor deposition source. The obtained vapor-deposited film was baked at 70 ° C. for 10 minutes to form a fluororesin film that becomes a dense and smooth surface liquid-repellent film, and a nozzle plate was produced. About the obtained nozzle plate, in the same manner as in Example 1, the presence / absence of a liquid repellent film on the inner wall surface of the nozzle and the presence / absence of a slope region were confirmed, and t2 / t1 was measured.

<Preparation of ink>
The same ink as in Example 1 was used.

(Comparative Examples 3 to 7)
<Preparation of nozzle plate>
The same nozzle plate as in Example 1 was used.

<Preparation of nozzle plate and preparation of ink>
Inks used in Comparative Examples 2 to 7 were prepared in the same manner as in Example 1 except that the ink composition in Example 1 was changed to the composition shown in Table 2-1.

*: The film thickness t2 of the liquid repellent film on the inner wall surface side of the nozzle is 1/10 or less (t2 / t1 ≦ 0.1) of the film thickness t1 of the liquid repellent film area on the liquid ejection surface side.
**: The film thickness t2 of the liquid repellent film on the inner wall surface side of the nozzle exceeds 1/10 of the film thickness t1 of the liquid repellent film area on the liquid discharge surface side.
* AF2400: Tetrafluoroethylene perfluorodioxole copolymer (Teflon (registered trademark) AF2400, manufactured by DuPont)
* AF1600: Tetrafluoroethylene perfluorodioxole copolymer (trade name, Teflon (registered trademark) AF2400, AF1600, manufactured by DuPont)
* OPTOOL DSX: Fluorine-containing acrylate ester polymer solution, manufactured by Daikin Industries, Ltd.

* Movinyl 5450: Nippon Synthetic Chemical Industry * TEGO WET 270: Evonik Industries * Surfinol 465: Shin-Etsu Chemical Co., Ltd.

<Dynamic surface tension>
The dynamic surface tension of the ink used in each example or comparative example was measured with a portable surface tensiometer (manufactured by Eiko Seiki Co., Ltd., SITA DynoTester) at a temperature of 25 ° C. and a bubblelifetime of 15 msec.

<Static surface tension>
The static surface tension of each ink was measured using a surface tension meter (DY300, manufactured by Kyowa Interface Co., Ltd.) at a temperature of 25 ° C.
Table 3 shows the results of dynamic surface tension measurement, static surface tension measurement, and dynamic surface tension measurement divided by static surface tension measurement. In Table 3, the unit of the measurement result of the dynamic surface tension and the measurement result of the static surface tension is “mN / m”.

  In each example and comparative example, an ink jet printer (Ricoh Co., Ltd.) serving as a liquid ejection head having a nozzle plate shown in Table 1 and an ink shown in Table 2-1 or Table 2-2 was ejected. Manufactured by IPSiO GXe5500). Various characteristics shown below were evaluated using the inkjet printers of the examples and comparative examples. The results are shown in Table 4.

Evaluation 1 <Beading>
Using GXe5500, a glossy paper-clean mode and no color correction were selected on Ricoh Business Coat Gloss 100, a cyan solid image was printed, and density unevenness (beading) was visually determined. If it is B rank or more, an apparatus can be used practically suitably.

[Evaluation criteria]
A: None at all.
B: Uneven density can be confirmed from 30 cm away.
C: Density unevenness can be confirmed even from a distance of 1 m.
D: Density unevenness can be confirmed even from a distance of 1.5 m or more.

<Discharge stability>
A nozzle check pattern was printed and printed in the state after 30,000 cleanings (after endurance test) using the inkjet printers of each example and comparative example (Ricoh Co., Ltd., IPSiO GXe5500). The nozzle check pattern was visually observed and the ejection stability was evaluated according to the following criteria based on the presence or absence of jet bending. If it is B rank or more, an apparatus can be used practically suitably.

[Evaluation criteria]
A: Good discharge stability equivalent to the initial state B: Discharge abnormality is 10 ch or less C: Discharge abnormality is 100 ch or less D: Discharge abnormality is 150 ch or less

<Ink storage stability>
Using E-550L (manufactured by Toki Sangyo Co., Ltd .: corn 1 ° 34 ′ × R24), the storage stability is determined from the viscosity before storage and the viscosity measured after storage in a sealed container at 70 ° C. for 14 days. It calculated | required according to the type | formula and evaluated based on the following references | standards. If it is A rank, an apparatus can be used practically suitably.

[Evaluation criteria]
A: Within 100 ± 5% B: More than 100 ± 5% to less than ± 10% C: 100 ± 10% or more

JP 2008-188911 A

DESCRIPTION OF SYMBOLS 1 Nozzle plate 11 Nozzle 20 Nozzle base material 21 Nozzle hole 30 Intermediate layer 40 Liquid repellent film 2 Flow path plate 3 Vibration plate member 6 Individual liquid chamber 10 Common liquid chamber 12 Piezoelectric member 16 Frame member 403 Carriage 404 Liquid discharge head 440 Liquid discharge unit

Claims (11)

A nozzle for discharging liquid;
A liquid ejection surface side, and a nozzle plate having a liquid repellent film on the inner wall surface side of the nozzle,
The liquid repellent film contains a fluororesin containing a structural unit having a fluorine-containing heterocyclic structure,
The relationship between the dynamic surface tension A and the static surface tension B at 15 ms of the liquid is 1.5 ≦ A / B ≦ 2.
An apparatus for ejecting a liquid, wherein a dynamic surface tension A of the liquid at 15 ms is 25 mN / m or more and 35 mN / m or less. The apparatus for discharging a liquid according to claim 1, wherein the fluororesin further includes a structural unit represented by the following structural formula (x).
  The apparatus for discharging a liquid according to claim 1, wherein the fluorine-containing heterocyclic structure has an ether bond.   4. The liquid repellent film according to claim 1, wherein the liquid repellent film has a slope region that is inclined in a direction in which the film thickness decreases toward an edge side of the nozzle on the liquid discharge surface side. 5. A device that ejects liquid.   The apparatus for ejecting liquid according to claim 1, wherein the liquid is ink containing water, a pigment, and an organic solvent.   The apparatus for ejecting a liquid according to claim 5, wherein the D50 particle size of the solid content in the ink is 80 nm or more and 200 nm or less.   5. The liquid ejection according to claim 4, wherein a film thickness of the liquid repellent film on the inner wall surface side is 1/10 or less of a film thickness of the liquid repellent film in an area other than the inclined area on the liquid ejection surface side. Device to do.   8. The relationship C <D is established between the number average molecular weight C of the fluororesin at the interface with the base of the liquid repellent film and the number average molecular weight D of the fluororesin on the outermost surface of the liquid repellent film. The apparatus which discharges the liquid as described in any one of these.   The apparatus which discharges the liquid as described in any one of Claims 1 thru | or 8 with which the base material and the said liquid-repellent film in the said nozzle plate are closely_contact | adhered via the silane coupling agent layer.   The apparatus for discharging a liquid according to claim 9, wherein the silane coupling agent layer includes a silane coupling agent having an amino group.   The apparatus for discharging a liquid according to claim 1, wherein a film thickness of the liquid repellent film on the liquid discharge surface side is 1 μm or more and 3 μm or less.