JP2010046824A - Method for manufacturing liquid delivering head, liquid delivering head and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a liquid delivering head capable of removing a water repellent layer in a nozzle without retaining it, and forming an image with a high image quality without generating disturbance on a reaching position of a delivered liquid, a liquid delivering head, and an image forming apparatus equipped with the liquid delivering head. <P>SOLUTION: In the method for manufacturing the liquid delivering head equipped with a nozzle plate having a nozzle for delivering the liquid, and formed with the water-repellent layer consisting of a resin film on the surface on the liquid delivering side where the nozzle hole is opened, the method for manufacturing the liquid delivering head is characterized by having the process wherein the water-repellent layer 21 consisting of the resin film is formed on the surface of the nozzle plate 10, the process wherein the nozzle plate is assembled in the liquid delivering head, and the process wherein a water-repellent layer dissolving liquid 30 for dissolving the water-repellent layer is filled in the liquid delivering head so as to form a meniscus of the water-repelling layer dissolving liquid in the nozzle. The liquid delivering head manufactured by the method, and the image forming apparatus equipped with the liquid delivering head, are also provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a liquid discharge head, a liquid discharge head, and an image forming apparatus, and in particular, a method for manufacturing a liquid discharge head having a water repellent layer on the surface, a liquid discharge head manufactured by the manufacturing method, and the liquid discharge The present invention relates to an image forming apparatus including a head.

  As an image forming apparatus such as a printer, a facsimile machine, a copying machine, or a multifunction machine of these, for example, an apparatus including a recording head composed of a liquid discharge head that discharges liquid droplets of a recording liquid (liquid) is used. Although it is also referred to as “paper”, the material is not limited, and a recording medium (recording medium, recording medium, transfer material, recording paper, etc. is also used synonymously) and a recording liquid as a liquid (hereinafter also referred to as ink). There is a so-called ink jet type image forming apparatus in which image formation (recording, printing, printing, and printing are also used synonymously) is performed by attaching the sheet to a sheet.

  The image forming apparatus means an apparatus for forming an image by discharging a liquid onto a medium such as paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics, etc. The term “not only” means not only giving an image having a meaning such as a character or a figure to a medium but also giving an image having no meaning such as a pattern to the medium. The liquid is not limited to the recording liquid and the ink, and is not particularly limited as long as it is a liquid capable of forming an image.

  Since the liquid ejection head performs recording by ejecting droplets from the nozzles, the shape and accuracy of the nozzles have a great influence on the ejection characteristics of the ink droplets. In order to eject droplets stably and straightly, it is an indispensable technique to optimize the design in the flow path and the method of applying pressure to the ink, but it is not sufficient. Since the characteristics of the surface of the nozzle forming member that forms the nozzle holes affect the ejection characteristics of the ink droplets, it is necessary to always maintain a stable surface state around the nozzles that eject the ink. For this purpose, it is necessary to provide water repellency so that ink does not adhere to and remain on the periphery of the nozzle opening on the ink ejection surface. If ink adheres to the periphery of the nozzle holes on the surface of the nozzle forming member and non-uniform ink pools occur, the ink droplet ejection direction is bent, the ink droplet size varies, and the ink droplet flying speed It is known that inconveniences such as instability occur.

  By covering the nozzle surface with a material having high water repellency, it is possible to improve the straightness of droplets ejected from the nozzle hole and to easily remove stains due to ink and paper dust adhering to the nozzle surface. However, in a head where the water repellent has entered the nozzle hole and covered the inner wall of the nozzle, the ink meniscus position formed inside the nozzle is stable under the influence of the attached water repellent when ejecting ink. The ink does not discharge or is discharged in a bent direction. Furthermore, the degree to which the water repellent enters the nozzles often varies from nozzle to nozzle.

In order to deal with such problems, conventionally, a method of applying a water repellent to the nozzle plate after blocking the nozzle hole with a filler or the like, or applying a water repellent to the nozzle plate and then moving the nozzle plate from the nozzle hole to the inside. There is known a method of manufacturing a nozzle plate of a liquid discharge head by, for example, a method of removing a water repellent that has entered so that the amount of water repellent penetrated is uniform in each nozzle hole. Specifically, a method of forming a water repellent film after filling the inside of the nozzle with a liquid or solid (see Patent Document 1), a method of forming a water repellent film while jetting air from the nozzle (see Patent Document 2) ),
A method of removing the water repellent that has entered the nozzle hole by irradiating plasma from the ink liquid chamber surface side of the nozzle plate after masking the nozzle surface (see Patent Document 3), soaking in an organic solvent in the nozzle hole Remove the water repellent agent that flows in the organic solvent, places it under the organic solvent, generates ultrasonic waves in the organic solvent by the ultrasonic source, and removes the fluororesin adhering to the nozzle holes by this ultrasonic wave The method (refer patent document 4) etc. are proposed.

JP-A-63-122560 JP-A-62-59047 JP 2007-253394 A JP 2004-330793 A

  However, in the method described in Patent Document 1, when the liquid is filled, the intrusion of the treatment liquid cannot be sufficiently prevented, and when the solid is filled, it is difficult to remove the subsequent filler and remain. The filler may cause the ejection to be hindered. Further, in the method of Patent Document 2, it is difficult to uniformly discharge air from a plurality of nozzle holes, so that it is difficult to uniformly control the penetration of the water repellent. Furthermore, in the method of Patent Document 3, it is difficult to sufficiently remove the inner wall portion that is perpendicular to the nozzle surface. In the method of Patent Document 4, the peeled water repellent is large and the remaining factors hinder the discharge. There is a problem that can be.

  Therefore, the present invention has been made in view of the above problems in the prior art, and can be removed without leaving the water-repellent layer in the nozzle, without causing disturbance in the landing position of the liquid to be discharged. An object of the present invention is to provide a method of manufacturing a liquid discharge head capable of forming a high-quality image, a liquid discharge head manufactured by the manufacturing method, and an image forming apparatus including the liquid discharge head.

The present invention provided to solve the above problems is as follows.
[1] In a method of manufacturing a liquid discharge head, which includes a nozzle plate having a nozzle for discharging a liquid and having a water repellent layer made of a resin film formed on a surface on a liquid discharge side where a nozzle hole is opened, the nozzle plate Forming a water repellent layer made of the resin film on the surface; incorporating the nozzle plate into the liquid discharge head; and forming a meniscus of the water repellent layer solution in the nozzle. And a step of filling the water repellent layer solution.
[2] The method for manufacturing a liquid discharge head according to [1], wherein the resin film of the water repellent layer is a monomolecular film.
[3] The liquid according to [1] or [2], wherein a position where the meniscus is formed is a position where the inner diameter of the nozzle is the smallest and closest to the opening of the nozzle hole. Manufacturing method of the discharge head.
[4] The method for manufacturing a liquid discharge head according to any one of [1] to [3], wherein the water-repellent layer solution contains a surfactant.
[5] A liquid discharge head manufactured by the method for manufacturing a liquid discharge head according to any one of [1] to [4].
[6] An image forming apparatus comprising a liquid discharge head manufactured by the method of manufacturing a liquid discharge head according to any one of [1] to [4].

  According to the present invention, it is possible to remove the water-repellent layer in the nozzle without leaving it, and to manufacture a liquid ejection head capable of forming a high-quality image without causing disturbance in the landing position of the ejected liquid A method, a liquid discharge head manufactured by the manufacturing method, and an image forming apparatus including the liquid discharge head can be provided.

As an effect of the present invention, according to the invention of claim 1, since the water repellent layer solution is filled so as to form a meniscus in the nozzle, the water repellent layer that has entered the nozzle is dissolved. Thus, it is possible to manufacture a liquid discharge head capable of forming a high-quality image without disturbing the landing position of the liquid that is removed together with the water-repellent layer solution and discharged.
According to the invention of claim 2, in the method of manufacturing a liquid discharge head according to claim 1, since the resin film of the water repellent layer is a monomolecular film, Because it dissolves without creating a gap in between, the liquid that dissolves the water-repellent layer by capillary action spreads from the meniscus position, and the water-repellent layer does not peel from the substrate, so the water-repellent layer solution over a long period of time The durability of the water-repellent layer formed at the end of the nozzle hole can be maintained even when filled.
According to a third aspect of the present invention, in the method of manufacturing a liquid ejection head according to the first or second aspect, the position where the meniscus is formed is the smallest inner diameter of the nozzle and the opening of the nozzle hole. Since it is the closest position, the meniscus position of each nozzle becomes uniform, and as a result, the variation in the landing position of the discharged liquid can be reduced.
According to a fourth aspect of the present invention, in the method for manufacturing a liquid ejection head according to any one of the first to third aspects, the water-repellent layer solution contains a surfactant, and therefore the water-repellent layer is dissolved. The surface tension of the liquid can be reduced, and variations in the position of the meniscus formed in each nozzle can be suppressed.
According to the invention of claim 5, since the liquid discharge head is manufactured by the method of manufacturing a liquid discharge head according to any one of claims 1 to 4, by using the liquid discharge head, Therefore, it is possible to form a high-quality image without disturbing the landing position of the discharged liquid.
According to the invention of claim 6, in an image forming apparatus for forming an image by discharging droplets from the liquid discharge head, the liquid manufactured by the method of manufacturing a liquid discharge head according to any one of claims 1 to 4. Since the image forming apparatus includes the ejection head, a high-quality image can be formed without causing disturbance in the landing position of the liquid to be ejected.

Hereinafter, the liquid discharge head and the manufacturing method thereof according to the present invention will be described together.
The liquid discharge head of the present invention includes a step of forming a water repellent layer made of a resin film on the surface of the nozzle plate, a step of incorporating the nozzle plate into the liquid discharge head, and a water repellent layer solution for dissolving the water repellent layer. Filling the inside.
The liquid discharge head of the present invention is manufactured by the above-described steps, and a nozzle that discharges droplets, a liquid chamber that communicates with the nozzle (also referred to as a pressurized liquid chamber, a discharge chamber, a pressure chamber, a liquid flow path, and the like), Pressure generating means for generating a pressure to pressurize the liquid in the liquid chamber, and the liquid in the liquid chamber is pressurized with the pressure generated by the pressure generating means, thereby ejecting droplets from the nozzle. The nozzle is formed by a through hole provided in the thickness direction of a nozzle plate serving as a base.
No particular limitation is imposed on the nozzle plate as long as the strength of the nozzle plate can be ensured and the surface is hydrophilic. For example, metals such as nickel and stainless steel, hydrophilic resins, and combinations thereof From the above, it can be appropriately selected as necessary.

A water repellent layer made of a resin film is formed on the surface on the liquid ejection side where the nozzle holes of the nozzle plate are opened.
The resin material for forming the resin film is not particularly limited as long as a water-repellent film can be formed, and can be appropriately selected according to the purpose. Examples thereof include silicone resins and fluororesins. The resin is preferably monomolecular, that is, the formed resin film is preferably a monomolecular film.

  The resin film can be formed by applying a coating liquid containing the resin material to the surface on the liquid discharge side where the nozzle holes of the nozzle plate are opened, and performing a drying process or the like as necessary. Moreover, a resin film can be formed by vapor deposition.

It is preferable that the water-repellent layer made of the resin film is made to penetrate through a region formed on the nozzle hole opening in advance. Examples of the opening treatment include methods such as O ₂ plasma irradiation and laser irradiation.
Further, the water-repellent layer adhering to a portion perpendicular to the liquid discharge side surface on the inner wall of the nozzle cannot be sufficiently removed by plasma irradiation or laser irradiation. However, according to the method of manufacturing a liquid discharge head of the present invention. For example, the remaining water-repellent layer can be dissolved by being immersed in the water-repellent layer solution.

Hereinafter, dissolution of the water repellent layer will be described with reference to the drawings. 1 to 6 are sectional views of the nozzle plate. The shape of the meniscus is not shown in the figure.
FIG. 1 shows a state immediately after a water repellent layer 20 made of a resin film formed by polymerizing a large number of molecules is filled with a water repellent layer solution 30 in a nozzle plate 10 formed up to the inside of the nozzle. It is a schematic diagram.
FIG. 2 is a schematic view showing a state in which the water-repellent layer 20 is dissolved after a lapse of time since the water-repellent layer solution 30 is filled.
If the nozzle has a sufficiently thin tubular structure, the influence of the capillary phenomenon is stronger than the influence of the water-repellent layer statically. Therefore, if the nozzle holes are configured uniformly, the filled water-repellent layer solution The position where the meniscus is stretched is also substantially uniform for each nozzle. Therefore, the boundary where the water repellent layer enters the nozzle hole can be set to a substantially uniform position for each nozzle.

  As shown in FIG. 2, the water repellent layer adhering to the inner wall portion perpendicular to the nozzle hole surface of the nozzle cannot be removed sufficiently by plasma irradiation, but can be removed because it can be immersed in the liquid water repellent layer solution. Is possible. Further, in the present invention, unlike the case where the water repellent is physically peeled off by an ultrasonic impact or the like, the water repellent layer is dissolved, so that the peeled water repellent layer does not remain as a solid substance and is left from the nozzle hole. It can be removed as a liquid.

  On the other hand, FIG. 3 shows that when the water repellent layer 20 made of a resin film formed by polymerizing a large number of molecules is immersed in the water repellent layer solution 30 for a long time, the water repellent layer 20 peels from the nozzle plate 10. FIG. 3 is a schematic diagram showing a state in which a water repellent layer solution 30 enters a gap by capillary action. As described above, when the water-repellent layer solution 30 is filled for an excessively long period of time, the water-repellent layer 20 made of a resin film that becomes a macromolecule by polymerization is dissolved in the base material and the water-repellent layer by dissolution at the liquid interface. And a water repellent layer solution 30 is infiltrated into the gap by capillary action, and the water repellent layer is peeled off from the interface between the water repellent layer and the substrate, and is floated in FIG. As shown, it may be scraped off by wiping or the like.

In order to avoid this phenomenon, the resin film forming the water repellent layer 20 is preferably a monomolecular film made of monomolecules.
FIG. 5 is a view showing a state immediately after the water repellent layer solution 30 is filled in the nozzle plate 10 in which the water repellent layer 21 made of a monomolecular film is formed on the inner wall of the nozzle and the meniscus 31 is formed.
The water-repellent layer 21 that has come into contact with the water-repellent layer solution 30 at the interface is dissolved, but since it is a single molecule, there is no bond extending in the horizontal direction between the molecules, and between the nozzle plate 10 and the water-repellent layer 21. In such a case, there is no gap as shown in FIG. This is shown in FIG.
Therefore, even if the state in which the water repellent layer solution 30 is filled for a long time is maintained, the durability of the water repellent layer 21 at the edge portion of the nozzle hole does not deteriorate.

  When applied to an ink jet recording apparatus, the water repellent layer solution is preferably weakly alkaline with a pH higher than that of the ink that is the recording liquid, and more preferably pH 9.5 to 11. Even if the pH exceeds 11 or less than 9.5, the metal in the liquid chamber may be dissolved, which is not preferable.

The water repellent layer solution contains water as a solvent, but may further contain a water-soluble organic solvent and other additives as other components.
Examples of water-soluble organic solvents include amides such as dimethylformamide and dimethylacetamide, ketones such as acetone, ethers such as tetrahydrofuran and dioxane, polyalkylene glycols such as polyethylene glycol and polypropylene glycol, ethylene glycol, and propylene glycol. , Alkylene glycols such as butylene glycol, triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol, diethylene glycol, polyvalent such as ethylene glycol methyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether Lower alkyl ethers of alcohol, ethanol, isopropyl alcohol, n-butyl alcohol, isobuty Other monohydric alcohols such as alcohols, glycerin, N- methyl-2-pyrrolidone, 1,3-dimethyl - imidazolidinone, triethanolamine, sulfolane, dimethyl monkey Hoki side, and the like. Although there is no restriction | limiting in particular about content of the said water-soluble organic solvent, For example, 5 to 60% of the total mass, Furthermore, 5 to 40% is a suitable range.

In the method for manufacturing a liquid discharge head of the present invention, a surface active agent is added to the water repellent layer solution so that the meniscus position is more uniformly formed in each nozzle, and the surface tension of the water repellent layer solution is increased. By sufficiently lowering, variation in meniscus position formed after filling can be suppressed.
By reducing the surface tension of the water repellent layer solution, the influence of capillary action is strengthened, and the position where the meniscus is formed is uniformly determined from the nozzle opening to the position where the nozzle inner diameter is the smallest.

As the surfactant added to the water repellent layer solution, a nonionic surfactant or an anionic surfactant is preferable.
Examples of low molecular weight anionic surfactants include disodium lauryl sulfosuccinate, disodium polyoxyethylene lauroyl ethanolamide ester sulfosuccinate, disodium polyoxyethylene alkylsulfosuccinate, carboxylated polyoxyethylene lauryl ether sodium salt, Carboxylated polyoxyethylene tridecyl ether sodium salt, sodium polyoxyethylene lauryl ether sulfate, polyoxyethylene lauryl ether sulfate triethanolamine, polyoxyethylene alkyl ether sodium sulfate, sodium alkyl sulfate, alkyl sulfate triethanolamine, etc. However, it is not limited to these.
A suitable amount of the anionic substance as described above is in the range of 0.05 to 10% by mass, more preferably 0.05 to 5% by mass, based on the total amount.

  In addition to the above components, a pH adjuster, an antiseptic, an antifungal agent, an antifoaming agent, and the like may be added to the water repellent layer solution.

The liquid discharge head of the present invention and the image recording apparatus equipped with the liquid discharge head are shipped in a state where the water repellent layer solution is filled in the head.
The liquid discharge head of the present invention and the image recording apparatus mounted with the liquid discharge are preferably shipped by a shipping method in which the head is filled with a water-repellent layer solution.
Although it takes time to dissolve the water-repellent layer inside the nozzle, there is a problem that the inventory becomes excessive if the shipment is stopped until the dissolution is completed. On the other hand, according to the shipping method as described above, the time from head shipment to initial filling can be used effectively.

  Next, an embodiment of an image forming apparatus including a liquid ejection head according to the present invention will be described below with reference to FIG. FIG. 7 is a schematic configuration diagram illustrating the overall configuration of the mechanism unit of the image forming apparatus of the present invention.

  This image forming apparatus is a serial type image forming apparatus, and a carriage 93 is slidably held in a main scanning direction by main and slave guide rods 91 and 92 which are guide members horizontally mounted on left and right side plates, and is not shown. The motor moves and scans in the direction indicated by the arrow (carriage main scanning direction) via the timing belt.

  The carriage 93 includes a plurality of recording heads 94 including the liquid discharge heads according to the present invention for discharging ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (K). Nozzle rows composed of nozzles are arranged in the sub-scanning direction orthogonal to the main scanning direction, and are mounted with the ink droplet ejection direction facing downward.

  The carriage 93 is equipped with a head tank 95 for supplying ink of each color corresponding to the nozzle row of the recording head 94.

  On the other hand, as a sheet feeding unit for feeding sheets stacked on the sheet stacking unit (pressure plate) 83 of the sheet feeding tray, a sheet feeding roller 101 that separates and feeds sheets one by one from the sheet stacking unit 83, and a sheet feeding unit. A separation pad 102 made of a material having a large friction coefficient is provided facing the paper roller 101, and this separation pad is urged toward the sheet feeding roller.

  In order to feed the paper fed from the paper feeding unit to the lower side of the recording head 94, a guide member 103 for guiding the paper, a counter roller, a conveyance guide member, and a pressing member having a tip pressure roller are provided. And a conveyance belt which is a conveyance means for electrostatically attracting the fed paper and conveying it at a position facing the recording head 94.

  Further, a maintenance / recovery mechanism (not shown) including a recovery means for maintaining and recovering the state of the nozzles of the recording head 94 is disposed in a non-printing area on one side of the carriage 93 in the scanning direction. In this maintenance and recovery mechanism, each cap member for capping each nozzle surface of the recording head 94, a wiper blade which is a blade member for wiping the nozzle surface, and a recording for discharging the thickened recording liquid are recorded. An empty discharge receptacle for receiving droplets when performing an empty discharge for discharging droplets that do not contribute to the liquid is provided.

  Further, in the non-printing area on the other side of the carriage 93 in the scanning direction, the liquid that receives liquid droplets when performing idle ejection for ejecting liquid droplets that do not contribute to recording in order to discharge the recording liquid thickened during recording or the like. An ink collection unit (empty discharge receptacle), which is a collection container, is arranged, and this ink collection unit is provided with an opening along the nozzle row direction of the recording head 94.

  By driving the recording head 94 according to the image signal while moving the carriage 93, ink droplets are ejected onto the stopped paper to record one line, and after the paper is conveyed by a predetermined amount, the next line Make a record. Upon receiving a recording end signal or a signal that the trailing edge of the paper has reached the recording area, the recording operation is finished and the paper is discharged onto the paper discharge tray 86.

  In such a serial type image forming apparatus, by providing the liquid discharge head according to the present invention, stable droplet discharge characteristics can be obtained without causing disturbance in the landing position of the discharged liquid. It becomes possible to record image quality images.

Examples of the present invention will be described below.
The nozzle plates A and B of the liquid discharge head were produced by the following method.
1) Preparation of nozzle plate A A polymer water repellent (X-40-9250 (10%) + KR-400 (90%), manufactured by Shin-Etsu Silicone Co., Ltd.) is applied to the Ni nozzle plate with nozzle holes in the nozzle plate. The water repellent formed by spin-coating the liquid discharge side surface of the nozzle opening and then irradiating O ₂ plasma from the liquid chamber surface side of the nozzle plate and entering the nozzle plate liquid chamber surface side of the nozzle inner surface from the nozzle hole The layer was removed.
The vicinity of the nozzle opening end of the nozzle hole is substantially perpendicular to the surface on the liquid discharge side, and the degree of removal of the water-repellent layer on the inner surface of the nozzle in this substantially perpendicular region varies between nozzles. It was observed.

2) Preparation of nozzle plate B After vacuum-depositing a monomolecular fluororesin water repellent (OPTOOL DSX, manufactured by Daikin Industries, Ltd.) on the surface of the liquid ejection side where the nozzle holes of the nozzle plate are opened. Then, O ₂ plasma was irradiated from the liquid chamber surface side of the nozzle plate to remove the water-repellent layer made of a monomolecular resin film formed by entering the nozzle plate liquid chamber surface side of the nozzle inner surface from the nozzle hole.
The vicinity of the nozzle opening end of the nozzle hole is substantially perpendicular to the surface on the liquid discharge side, and the degree of removal of the water-repellent layer on the inner surface of the nozzle in this substantially perpendicular region varies between nozzles. It was observed.

Example 1
A liquid discharge head was manufactured using the nozzle plate A.
The prepared liquid discharge head was filled with a water repellent layer solution A having the composition shown below to form a meniscus in the nozzle. After 3 weeks in an environment of 50 ° C., it was mounted on an image recording apparatus (IPSIO G707 modified machine, manufactured by Ricoh) shown in FIG. 7 and filled with ink to produce a printed matter consisting of a halftone dot of 150 dpi pitch. The ink landing position variation was evaluated from the prepared printed matter. The results are shown in Table 1.

<Composition of water repellent layer solution A>
Glycerin 25 parts 2-pyrrolidone 2 parts sodium dehydroacetate 0.2 parts sodium thiosulfate 0.2 parts antiseptic / antifungal agent 0.4 parts antifoaming agent (manufactured by Shin-Etsu Chemical Co., Ltd., KM-72F) 0.1 part ion-exchanged water Residual amount To the above composition, a pH adjusting agent was further added to adjust the pH to 11.0.

(Example 2)
Except that a liquid discharge head was produced using the nozzle plate B, the water repellent layer solution A was filled in the same manner as in Example 1 and left at 50 ° C. for 3 weeks. It was mounted on a recording device (IPSIO G707 modified machine, manufactured by Ricoh Co., Ltd.) and filled with ink to produce a printed matter consisting of halftone dots of 150 dpi pitch. The ink landing position variation was evaluated from the prepared printed matter. In addition, the meniscus formation position was observed immediately after filling the water-repellent layer solution. The results are shown in Table 1.

(Example 3)
A liquid discharge head was manufactured using the nozzle plate B.
The prepared liquid discharge head was filled with a water-repellent layer solution B having the following composition to form a meniscus in the nozzle. After 3 weeks in an environment of 50 ° C., it was mounted on an image recording apparatus (IPSIO G707 modified machine, manufactured by Ricoh) shown in FIG. 7 and filled with ink to create a printed matter consisting of halftone dots of 150 dpi pitch. The ink landing position variation was evaluated from the prepared printed matter. In addition, the meniscus formation position was observed immediately after filling the water-repellent layer solution. The results are shown in Table 1.

<Composition of water repellent layer solution B>
Glycerin 25 parts 2-Pyrrolidone 2 parts Olefin STG (manufactured by Shin-Etsu Chemical) 2.0 parts Sodium dehydroacetate 0.2 part Sodium thiosulfate 0.2 part Antiseptic / antifungal agent 0.4 part Antifoam (manufactured by Shin-Etsu Chemical Co., Ltd., KM-72F) 0.1 parts Ion-exchanged water Remaining The composition was further adjusted to pH 11.0 by adding a pH adjuster.

(Comparative Example 1)
A liquid discharge head was manufactured using the nozzle plate A. After the prepared liquid discharge head is placed in a 50 ° C. environment for 3 weeks, it is mounted on the image recording apparatus (IPSIO G707 remodeling machine, manufactured by Ricoh) shown in FIG. 7 and filled with ink from a halftone dot of 150 dpi pitch. I made a printed material. The ink landing position variation was evaluated from the prepared printed matter. The results are shown in Table 1.

(Comparative Example 2)
A liquid discharge head was manufactured using the nozzle plate B. After the prepared liquid discharge head is placed in a 50 ° C. environment for 3 weeks, it is mounted on the image recording apparatus (IPSIO G707 remodeling machine, manufactured by Ricoh) shown in FIG. 7 and filled with ink from a halftone dot of 150 dpi pitch. I made a printed material. The ink landing position variation was evaluated from the prepared printed matter. The results are shown in Table 1.

The ink landing position variation was evaluated according to the following criteria by observing the printed matter.
A: White stripes and black stripes are not observed, and ink is printed at a regular pitch.
A: Slightly disturbed ink landing position, but white and black streaks are not so noticeable when printing on plain paper.
(Triangle | delta): Disturbance is seen in a landing position and there exists a nozzle hole which produces a white stripe and a black stripe by printing.
X: The ink ejected from most of the nozzle holes has a disordered landing position. There are very many white and black stripes.

From the results shown in Table 1, it was found that the liquid ejection head of the example filled with the water repellent layer solution had a smaller variation in ink landing position than the head of the comparative example without filling. In addition, when Examples 2 and 3 are compared, Example 3 in which the inside of the nozzle is immersed in a water-repellent layer solution B having a surface tension reduced by adding a surfactant (olefin STG (manufactured by Shin-Etsu Chemical)) is ink landing. It was found that the position variation was extremely small.
On the other hand, as a result of observing the heads filled with the water-repellent layer solution for Examples 2 and 3, the heads of Example 2 showed slight variations in the positions where meniscuses were formed between the nozzles. On the other hand, in the head of Example 3, the position where the meniscus was formed was uniform. For this reason, by increasing the wettability of the water-repellent layer solution, it is possible to suppress variations in the meniscus formation position of the filled solution without being affected by the water-repellent layer formed inside the nozzle. It is considered that the meniscus position is determined at a uniform position between the nozzles depending on the shape of the nozzle plate.

Example 4
In the image recording apparatus of Example 1, wiping was performed 1000 times on the surface on the liquid discharge side where the nozzle hole of the mounted liquid discharge head was opened. After that, the ink was filled again, and a printed matter having a halftone dot of 150 dpi pitch was created. The ink landing position variation was evaluated from the prepared printed matter according to the same criteria as described above. The results are shown in Table 2.

(Example 5)
In the image forming apparatus of Example 2, wiping was performed in the same manner as in Example 4 to produce a printed matter. The ink landing position variation was evaluated from the prepared printed matter according to the same criteria as described above. The results are shown in Table 2.

(Example 6)
In the image forming apparatus of Example 3, wiping was performed in the same manner as in Example 4 to produce a printed matter. The ink landing position variation was evaluated from the prepared printed matter according to the same criteria as described above. The results are shown in Table 2.

From the results in Table 2, in Example 4 having a water-repellent layer composed of a polymer resin film in which a large number of molecules are polymerized after 1000 times of wiping, the landing position variation was large, whereas the repellent property of the monomolecular film was large. Examples 5 and 6 having an aqueous layer were as good as before wiping (Examples 2 and 4 respectively).
When the nozzle edge of the liquid ejection head of Example 4 is observed, there is a portion where the ink repellency is lowered and the ink is easily attached on the lower side of the wiping direction of the nozzle hole, and the water repellent layer near the nozzle is peeled off. It was observed that some sites disappeared. From this, it became clear that the water repellent layer is preferably formed of a monomolecular film made of a monomolecular resin.

  Although the present invention has been described with the embodiments shown in the drawings, the present invention is not limited to the embodiments shown in the drawings, and other embodiments, additions, modifications, deletions, etc. Can be changed within the range that can be conceived, and any embodiment is included in the scope of the present invention as long as the effects and advantages of the present invention are exhibited.

It is a schematic diagram which shows the state immediately after filling the nozzle plate in which the water repellent layer which consists of a resin film formed by polymerizing many molecules was formed into the water repellent layer solution. It is a schematic diagram showing a state after a predetermined time has elapsed after filling a water-repellent layer solution into a nozzle plate on which a water-repellent layer made of a resin film formed by polymerizing a large number of molecules is formed. It is a schematic diagram showing a state after a long time has passed since a water repellent layer solution was filled in a nozzle plate on which a water repellent layer made of a resin film formed by polymerizing a large number of molecules was formed. It is a schematic diagram which shows the state by which the water repellent layer was peeled off from the interface of a water repellent layer and a base material, and was shaved off. It is sectional drawing which showed the state immediately after filling the nozzle plate in which the water repellent layer which consists of a monomolecular film was formed with the water repellent layer solution. It is sectional drawing which showed the state which passed for a fixed time, after filling the water-repellent layer solution in the nozzle plate in which the water-repellent layer which consists of a monomolecular film was formed. 1 is a schematic configuration diagram illustrating an overall configuration of a mechanism unit of an image forming apparatus of the present invention.

Explanation of symbols

10 Nozzle plate 20 Water repellent layer (water repellent layer made of a resin film formed by polymerizing a number of molecules)
21 Water repellent layer (water repellent layer composed of monomolecular film)
30 Water repellent layer solution 31 Meniscus 94 Recording head

Claims (6)

In a method for manufacturing a liquid discharge head, comprising a nozzle plate having a nozzle for discharging a liquid and having a water repellent layer made of a resin film formed on a surface on a liquid discharge side where a nozzle hole opens.
Forming a water repellent layer made of the resin film on the nozzle plate surface;
Incorporating the nozzle plate into the liquid ejection head;
And a step of filling the liquid discharge head with the water-repellent layer solution so as to form a meniscus of the water-repellent layer solution in the nozzle.   The method for manufacturing a liquid ejection head according to claim 1, wherein the resin film of the water repellent layer is a monomolecular film.   3. The method of manufacturing a liquid ejection head according to claim 1, wherein a position where the meniscus is formed is a position where the inner diameter of the nozzle is the smallest and closest to the opening of the nozzle hole.   The method of manufacturing a liquid discharge head according to claim 1, wherein the water repellent layer solution contains a surfactant.   A liquid discharge head manufactured by the method of manufacturing a liquid discharge head according to claim 1.   An image forming apparatus comprising the liquid discharge head manufactured by the method of manufacturing a liquid discharge head according to claim 1.

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