JPH06155748A - Liquid jet printing head and liquid jet printer equipped therewith - Google Patents

Abstract

PURPOSE:To provide a liquid jet printing head excellent in emission stability, hard to receive the damage due to an external cause and excellent in abrasion resistance. CONSTITUTION:A liquid jet printing head has ink emitting orifices 7a and electrothermal converters 3 generating energy bringing about the emission of ink from the emitting orifices 7a. A layer of a water repelling material obtained by dispersing fine inorg. particles in a water repelling resin in a desired state is provided to the emitting orifice surface 7b having the emitting orifices 7a arranged thereto. By this constitution, the abrasion resistance and water repellency of the emitting orifice surface 7b are excellent and the emission stability of ink is enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention records by recording liquid (generally ink) ejected from a liquid ejection port, flying to form small droplets, and attaching the small droplets to a recording surface. Liquid jetting (also referred to as "inkjet") printheads that perform printing. More specifically, the present invention provides
The present invention relates to a liquid jet print head in which a peripheral surface of the liquid discharge port is subjected to a predetermined surface treatment. The invention also relates to a liquid jet printing apparatus comprising the improved liquid jet printhead. The present invention includes a method of making the improved liquid jet printhead.

[0002]

2. Description of the Related Art The ink jet printing method is a printing method which has attracted attention because it can perform high speed printing in a relatively low noise state. A typical configuration of a liquid jet print head used in the inkjet printing system is, for example, that shown in FIG. In FIG. 2, reference numeral 1 is a substrate for a liquid jet print head which is made of a material such as glass, aluminum or silicon. A liquid flow path 4 is formed by joining a top plate 2 provided with a groove to be the liquid flow path 4 to the base 1. An energy generating element 3 that generates energy for ejecting ink is provided in the liquid flow path 4. And the liquid flow path 4
The nozzle plate 7 is provided with an ejection port 7a for communicating with the nozzle and ejecting ink. The nozzle plate 7 is joined to the joined body of the base 1 and the top plate 2 to form a liquid jet print head.

In such a liquid jet print head, when an ink droplet is ejected from an ejection port for printing, a part of the ink droplet drips and adheres to the ejection port surface on which the ejection port is provided. There is. When the ink adheres to the ejection port surface in this way, the adhered ink deflects the flight direction of the ink droplet to be ejected in contact with the ink droplet to be ejected next, or imposes a load on the ejected ink droplet. As a result, the ejection speed of ink is reduced. This phenomenon is particularly noticeable when ink is ejected at a high frequency. The occurrence of this phenomenon becomes a very serious problem especially in the case of high-speed printing in which the ink is ejected 10,000 times or more per second. In other words, the ejection direction and ejection speed of the ink vary, and accurate printing cannot be performed. In the worst case, the ink attached to the ejection port surface blocks the ejection port, and the ink droplet is ejected. It may disappear. As a means for solving such a problem, there is known a method of applying water repellent treatment to the peripheral portion of the ejection port of the liquid jet print head. When the water repellent treatment is applied to the peripheral portion of the ejection port by this method, ink does not remain on the peripheral portion of the ejection port, and the above-mentioned problem is solved to some extent. Here, as a place to apply water repellent treatment,
It is known that only the discharge port surface is preferable. The reason for limiting the location of water repellent treatment in this way is, except for the discharge port surface,
Particularly, when the water repellent treatment is performed in the liquid flow path, the capillary force acting on the ink supply in the liquid flow path is reduced, so that the ink supply may not be properly performed. From the viewpoint of improving the ejection stability, the water repellent treatment on the ejection port surface is generally performed so that the water repellency has a clear contrast between the ejection port surface and the inner wall of the liquid flow path. Regarding this water-repellent treatment, the ejection-repellent surface that has been subjected to the water-repellent treatment retains ink repellency at the initial stage, but is oxidized by the atmosphere or ink during the process of repeatedly using the liquid jet print head. In addition, since the ink repellency gradually deteriorates due to peeling from the discharge port surface due to the outflowing ink, etc., regarding the water repellent treatment of the discharge port surface, in addition to water repellency, there are points such as chemical stability and adhesion. Also needs to be considered.

[0004]

However, even when the water-repellent ejection port surface is sufficient for ink repellency, ink may adhere to the ejection port surface as ink droplets. is there. In this case, it is difficult to remove the ink droplets adhering to the ejection port surface from the ejection port surface without applying external force such as external vibration or mechanical scraping. As a result, this ink droplet merges with other ink droplets remaining on the ejection port surface to gradually become a large ink droplet, which interferes with the ejection of the ink from the ejection port and deflects the ejection direction of the ink ejected from the ejection port. There is a problem in that there is a risk that the ink may be discharged or ink may not be ejected. Therefore, the liquid jet printing apparatus is usually equipped with a wiping mechanism that wipes the ejection port surface with a cleaning blade as one of recovery processes.

As such a recovery processing mechanism of the liquid jet printing apparatus, in addition to the above-mentioned wiping mechanism, a suction recovery mechanism using a pump or the like for removing the thickened ink in the nozzle portion is provided. In recent years, such a suction recovery mechanism may be omitted from the viewpoint of meeting the demand for miniaturization of the liquid jet printing apparatus. In the case where the liquid jet printing apparatus has no suction recovery mechanism, ink with high viscosity often remains at the peripheral edge of the ejection port. In order to remove such residual ink, it is necessary to press the cleaning blade against the peripheral edge of the ejection port much more strongly than in the conventional case when wiping by the wiping mechanism. When increasing the pressure contact force of the cleaning blade in this way, a new problem arises. That is, the water-repellent cleaning blade is rubbed by the high-pressure contact force of the cleaning blade to deteriorate its water repellency with time, and as a result, stable ejection performance cannot be maintained.

In addition to this problem, another problem arises. That is,
If the cleaning blade or the discharge port surface of the liquid jet printing apparatus has dust or dirt attached thereto, the tendency of the liquid jet printing device to be damaged during wiping with the cleaning blade increases. Furthermore, as another problem, the recording material such as paper may be rubbed against the ejection opening surface due to poor conveyance, and as a result, the ejection opening surface may be damaged. For this reason, it is necessary for the ejection port surface to have more excellent wear resistance than before.

Further, as described above, in the case of high speed printing in which the ink is ejected 10,000 times or more per second,
Since the amount of ink ejected per unit time increases,
Ink tends to adhere to the periphery of the ejection port of the liquid jet print head. In order to prevent the adverse effect caused by the ink adhesion, it is necessary to shorten the wiping interval by the cleaning blade of the liquid jet print head and perform wiping frequently. Therefore, even in the case of high speed printing, it is required that the ejection opening surface has sufficient abrasion resistance.

By the way, in Japanese Patent Laid-Open No. 4-219959, a water repellent agent made of a polymer having a fluorine-containing heterocyclic structure in its main chain is used in order to improve the wear resistance of the ejection port surface of a liquid jet print head. Then, a technique for water-repellently treating the discharge port surface is disclosed. However, although this water repellent agent exhibits a sufficient function from the viewpoint of water repellency,
It is not sufficient from the viewpoint of wear resistance. That is, in the case where it is necessary to press the cleaning blade with a considerable pressing force as in the case of the liquid jet printing apparatus in which the suction recovery mechanism as described above is omitted, the discharge port surface is treated with the water repellent treatment agent. The above-mentioned problems cannot be solved because the wear resistance is not sufficient when used and treated.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a liquid jet print head which is excellent in ejection stability, is hard to be damaged by an external cause, and is excellent in wear resistance, and a liquid jet printing apparatus provided with the liquid jet print head. To do.

[0010]

In order to achieve the above object, the liquid jet print head of the present invention has an ejection port for ejecting a recording liquid and energy for ejecting the liquid through the ejection port. In a liquid jet print head including an energy generating element that generates a water-repellent ink, a liquid-repellent resin composed of inorganic fine particles dispersed in a desired state in a water-repellent resin is formed on a discharge port surface on which the discharge port is provided. It is characterized in that an aqueous material layer is provided.

Further, in a liquid jet print head provided with an ejection port for ejecting a recording liquid and an energy generating element for generating energy for ejecting the liquid through the ejection port, On the ejection port surface that is arranged, inorganic fine particles are dispersed in a water-repellent resin in a desired state, and a water-repellent material layer on which the fine particles are intermittently projected is provided on the surface. It may be one.

In each of the liquid jet print heads, the water repellent resin is an alternating copolymer of full olefin and vinyl ether, a photo-radical polymerization type fluororesin composition comprising a reactive oligomer and a diluting monomer, and a copolymer type comb. Type fluorine polymer, fluorosilicone, perfluorocyclopolymer, the inorganic fine particles are selected from silica, alumina, magnesia, the energy generating element is an electrothermal converter The average particle size of the inorganic fine particles is 1.0 μm or less, and further 0.5 μm.
The following may be used.

The liquid jet printing apparatus of the present invention comprises:
A liquid ejecting recording head comprising an ejection port for ejecting a recording liquid, and an energy generating element for generating energy for ejecting the liquid through the ejection port,
In a liquid jet printing apparatus including a drive signal supply unit for supplying a drive signal to the energy generating element of the liquid jet recording head, inorganic fine particles in a water-repellent resin are formed on a discharge port surface where the discharge port is provided. Is provided in a desired state, and a water-repellent material layer constituted by what is dispersed is provided.

Further, a liquid jet recording head having an ejection port for ejecting a recording liquid and an energy generating element for generating energy for ejecting the liquid through the ejection port, and the liquid ejection recording. A liquid jet printing apparatus comprising a drive signal supply means for supplying a drive signal to the energy generating element of the head,
On the ejection port surface to which the ejection port is connected, inorganic fine particles are dispersed in a water-repellent resin in a desired state,
The surface may be provided with a water repellent material layer in which the fine particles are intermittently projected.

In each of the above liquid jet printing devices, the water repellent resin is an alternating copolymer of full olefin and vinyl ether, a photo radical polymerization type fluororesin composition comprising a reactive oligomer and a diluting monomer, and a copolymer type comb. Type fluorine polymer, fluorosilicone, perfluorocyclopolymer, the inorganic fine particles are selected from silica, alumina, magnesia, the energy generating element is an electrothermal converter The average particle diameter of the inorganic fine particles is 1.0 μm or less, and more preferably 0.5 μm.
It may be m or less.

[0016]

In the present invention constructed as described above, the water repellent material layer is composed of the inorganic fine particles dispersed in the water repellent resin in a desired state. The exit surface is protected against dust and contact with the recording material, and wear resistance is improved. Therefore, even in the case of the liquid ejecting printing apparatus in which the above-described suction recovery mechanism is omitted, or in the case of the liquid ejecting print head for high-speed printing that ejects ink 10,000 times or more per second, the ejection port surface resistance The abrasion property is sufficiently maintained, and the deposits such as ink droplets adhering to the ejection port surface during the printing operation can be removed without damaging the ejection port surface, and stable ink ejection is performed.

Further, by making the water repellent material layer have a structure in which the inorganic fine particles are intermittently projected on the surface, the contact angle with the ink is remarkably improved. The reason why this contact angle is improved is not clear, but it is considered that an air layer is formed on the surface. By improving the contact angle, the ink is prevented from adhering to the peripheral portion of the ejection port, and the ejection stability is dramatically improved.

Typical examples of the inorganic fine particles used in the present invention include silica, alumina, magnesia, and the like. Examples of the water-repellent resin include alternating copolymers of full olefin and vinyl ether, reactive oligomers and diluting monomers. And a photo-radical polymerization type fluororesin composition, a copolymer type comb-type fluoropolymer, fluorosilicone, perfluorocyclopolymer and the like. However, the liquid ejection print head is not limited to these as long as it has characteristics such as hardness that can be used in the peripheral portion of the ejection port of the liquid ejection print head. Further, the particle size of the inorganic fine particles is generally a size in which the ejection port of the liquid jet print head is processed at the μm level, and therefore the upper limit of the inorganic fine particles is also limited according to the size. However, in general, the average particle size of the inorganic fine particles is preferably about 1 μm or less, more preferably 0.5 μm or less.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is a print head used in a bubble jet system which is one of the on-demand type ink jet printing systems (for example, US Pat. No. 44).
90728, U.S. Pat. No. 4,723,129), a print head used in a piezo system, which is one of on-demand type inkjet printing systems (for example, U.S. Pat. No. 3,683,212, U.S. Pat. No. 3,946,398). (Refer to the specification), a print head used in a continuous type inkjet printing system, and a print head used in an electrostatic suction type inkjet printing system. In any case, a water-repellent material layer composed of (a) inorganic fine particles in a water-repellent resin dispersed in a desired state on a discharge port surface provided with a discharge port for discharging ink, or (B) Inorganic fine particles in the water-repellent resin are dispersed in a desired state, and the surface is provided with a water-repellent material layer on which the fine particles are intermittently projected. As a result, deposits such as ink droplets that adhere to the surface of the water-repellent material layer during a printing operation can be removed without damaging the surface, and the desired ink is constantly discharged, resulting in a high-quality printed image. It becomes a place to be.

In the present invention, when the suction recovery mechanism is omitted,
Alternatively, an improved liquid jet print head and a liquid jet printing apparatus including the liquid jet print head are provided, which can suitably cope with any case of high-speed printing in which ink is discharged 10,000 times or more per second.

The liquid jet print head provided by the present invention has an ejection port for ejecting a recording liquid and an energy generating element for generating energy for ejecting the liquid through the ejection port. , (A) a water-repellent material layer composed of inorganic fine particles in a water-repellent resin dispersed in a desired state, or (b) inorganic fine particles in a water-repellent resin dispersed in a desired state, A water-repellent material layer in which the fine particles are intermittently projected is provided.

A liquid-jet printing apparatus provided by the present invention has a liquid-jet print having an ejection port for ejecting a recording liquid and an energy generating element for generating energy for ejecting the liquid through the ejection port. A water-repellent material layer comprising (a) inorganic fine particles in a water-repellent resin dispersed in a desired state on a discharge port surface provided with a head and provided with the discharge port of the liquid jet print head; Alternatively, (b) the inorganic fine particles in the water-repellent resin are dispersed in a desired state, and the surface is provided with a water-repellent material layer on which the fine particles intermittently protrude.

The following two modes can be mentioned as specific mode examples of the liquid jet print head provided by the present invention.

Head Mode Example 1: A discharge port for discharging a liquid, a heating resistor for generating heat energy for discharging the liquid from the discharge port, and the heat energy generated by being electrically connected to the heating resistor. A substrate for a liquid jet print head in which an electrothermal converter having a pair of wirings for supplying an electric signal to the heating resistor is arranged,
A liquid jet print head having a flow path for supplying a liquid in the vicinity of the electrothermal converter of the substrate, wherein the water repellent resin contains inorganic fine particles dispersed in a desired state. A water-repellent material layer is provided on the ejection port surface on which the ejection port is provided, and an adhered matter such as an ink droplet that adheres to the surface of the water-repellent material layer during the printing operation is removed from the surface. An improved liquid jet printhead that can be removed without damage, consistently delivering the desired ink ejection and providing high quality printed images.

Head Aspect Example 2: Discharge port for discharging liquid, heat generating resistor for generating heat energy for discharging liquid from the discharge port, and the heat energy generated by being electrically connected to the heat generating resistor A substrate for a liquid jet print head in which an electrothermal converter having a pair of wirings for supplying an electric signal to the heating resistor is arranged,
A liquid jet print head having a flow path for supplying a liquid in the vicinity of the electrothermal converter of the substrate, wherein the water repellent resin contains inorganic fine particles dispersed in a desired state. A water-repellent material layer on the surface of which the inorganic fine particles are intermittently projected is provided on a discharge port surface on which the discharge port is provided. It is an improved liquid jet print head capable of removing deposits such as deposited ink drops without damaging the surface, always stably ejecting desired ink, and providing high quality print images.

The following two modes can be mentioned as specific mode examples of the liquid jet printing apparatus provided by the present invention.

Apparatus mode example 1: (a) A discharge port for discharging a liquid, a heat generating resistor for generating heat energy for discharging the liquid from the discharge port, and the heat generating resistor electrically connected to the heat generating resistor. A liquid jet print head substrate having an electrothermal converter having a pair of wirings for supplying an electric signal for generating energy to the heating resistor, and the electrothermal converter of the substrate. A liquid jet printing head having a flow path for supplying a liquid in the vicinity thereof, and (b) a liquid jet printing apparatus having an electric signal supply unit for supplying an electric signal to the heating resistor of the liquid jet print head. And a water-repellent material layer composed of a dispersion of inorganic fine particles in a water-repellent resin in a desired state is formed on the ejection port surface on which the ejection port of the liquid jet print head is disposed. It characterized by being kicked,
Adhesives such as ink droplets adhering to the surface of the water-repellent material layer during a printing operation can be removed without damaging the surface, and desired ink ejection is always performed stably, resulting in a high-quality printed image. It is an improved liquid jet printing device.

Apparatus mode example 2: (a) A discharge port for discharging a liquid, a heat generating resistor for generating thermal energy for discharging the liquid from the discharge port, and the heat generating element electrically connected to the heat generating resistor. A liquid jet print head substrate having an electrothermal converter having a pair of wirings for supplying an electric signal for generating energy to the heating resistor, and the electrothermal converter of the substrate. A liquid jet printing head having a flow path for supplying a liquid in the vicinity thereof, and (b) a liquid jet printing apparatus having an electric signal supply unit for supplying an electric signal to the heating resistor of the liquid jet print head. A liquid repellent material layer comprising inorganic fine particles in a water repellent resin dispersed in a desired state, the water repellent material layer having the inorganic fine particles intermittently protruding on the surface thereof. It is characterized in that it is provided on the ejection port surface on which the ejection port of the head is arranged, and does not damage ink droplets or other adhering substances that adhere to the surface of the water repellent material layer during a printing operation. An improved liquid jet printing device that can be removed and consistently delivers the desired ink ejection consistently, resulting in high quality printed images.

The specific structure of the liquid jet print head (that is, the ink jet print head) having the above-described structure provided by the present invention and the manufacturing process thereof will be described below. The liquid jet print head provided by the present invention is typically of the construction shown in FIG. In FIG. 2, 1 is a substrate, 2 is a structural member, 3 is an electrothermal converter, 4 is a liquid flow path, 5 is a liquid chamber, 6 is a supply port, and 7 is It is a discharge port plate (nozzle plate), 7a is a discharge port, and 7b is a discharge port surface.

The liquid jet print head of the present invention is manufactured through the steps described below.

First, as shown in FIG. 3, two electrothermal converters 3 each having an aluminum electrode are provided on a substrate 1 made of glass, ceramic, plastic or the like.
Are formed by a semiconductor manufacturing process such as etching, vapor deposition, and sputtering. In addition, in FIG. 3, the number of electrothermal converters (that is, energy generating elements) is only two, but this is merely for the purpose of simplifying the drawing. The number of Therefore, in the following description, the number of electrothermal converters (energy generating elements) is two for the purpose of simplification. The number of the electrothermal converters and the liquid flow paths and the discharge ports corresponding to the electrothermal converters are not limited to two, and it is needless to say that the number may be appropriately set and provided. . Further, mainly for the purpose of improving durability, various functional layers such as a protective film are generally provided appropriately not only for the aluminum electrode and the electrothermal converter but also for other constituent elements. The present invention is effective regardless of the presence or absence of such a functional layer and the material of the layer.

Next, as shown in FIGS. 4 and 5, a solid layer is formed on one surface of the substrate 1 at the liquid flow path formation planned site 4 ′ and the liquid chamber formation planned site 5 ′ including the electrothermal converters 3. 9 is laminated. The solid layer 9 is removed through a process described later, and the liquid flow path 4 (see FIG. 2) and the liquid chamber 5 (see FIG. 2) are formed in the removed portion. Of course, the shapes of the liquid flow path 4 and the liquid chamber 5 can be set as desired. Solid layer 9
Also, the shape can be determined according to the shapes of the liquid flow path 4 and the liquid chamber 5. In the present embodiment, the liquid chamber 5 has each liquid flow path so that ink can be discharged from each of the two discharge ports 7a (see FIG. 2) provided corresponding to the two electrothermal converters 3. 4 is in communication with these so that ink can be supplied to them.

The formation of the solid layer 9 and the formation of the liquid flow path 4 and the liquid chamber 5 can be performed, for example, by a method using a lithographic means. For example, a positive type or negative type photosensitive dry film having an appropriate thickness is attached to the surface of the substrate 1, and a pattern corresponding to the liquid flow path 4 and the liquid chamber 5 in the photosensitive dry film is masked or exposed to light. Then, the solid layer 9 having a pattern corresponding to the liquid flow path 4 and the liquid chamber 5 is formed by developing. The photosensitive dry film used in this case may be any one which can be dissolved and removed by a solvent in a later step described later. In addition, it is preferable to use a positive type photosensitive dry film because the cross-sectional shape of the patterned solid layer 9 can be formed to more closely resemble a rectangle as compared with a negative type.

In addition to the photolithography means, printing means such as screen printing and concave plate printing using a concave plate produced by etching a metal substrate (for example, Ni, Cu) can be adopted. In this case, the patterned solid layer 9 can be provided with an appropriate thickness. Examples of the material of the solid layer 9 that can be used in this printing means include water-soluble polyvinyl alcohol-based resins, solvent-soluble vinyl chloride-based resins, vinyl acetate-based resins, vinyl chloride-vinyl acetate copolymer-based resins, and styrene-based resins.

After forming the solid layer 9 on the surface of the substrate 1 as described above, as shown in FIG. 6, a curable material 10 is laminated so as to cover the solid layer 9 and the curable material 10 is completely cured. Let When the curable material 10 is completely cured,
The structural member (top plate) 2 shown in FIG. As the curable material 10, any material can be used as long as it can be disposed so as to cover the solid layer 9, and the material forms the liquid flow path 4 and the liquid chamber 5 and is an inkjet print. Since it is a structural material of the head, it is desirable to select and use a material having excellent adhesiveness to the substrate 1, mechanical strength, dimensional stability, and corrosion resistance. As a specific example of such a material, an active energy ray-curable material that is liquid and hardens by being irradiated with active energy rays such as ultraviolet rays and electron beams, and two raw materials, a main agent and a curing agent, are used. Examples thereof include materials that are cured by mixing.

As a method of laminating the curable material 10, for example, a method of laminating by a means such as a discharge device using a nozzle corresponding to the shape of the substrate, an applicator, a curtain coater, a roll coater, a spray coater, a spin coater, or the like is concrete. It is mentioned as a thing. When the liquid curable material 10 is laminated, it is preferable to degas the material and then avoid mixing of air bubbles.

In this way, a laminated body in which the solid layer 9 and the curable material 10 are sequentially laminated on the surface of the substrate 1 is formed. After this, for example, when one end of the portion to be the liquid flow path 4 is not exposed, etc., the laminated body is cut at a required position with a dicing saw using a diamond blade or the like, if necessary. One end of the portion to be the path 4 is exposed. However, such a cutting operation is not always necessary. For example, when a liquid curable material 10 is used and a mold is used when laminating the curable material 10 so that one end of the portion that becomes the liquid flow path 4 is exposed in a desired shape without being covered. No cutting is necessary.

Then, the solid layer 9 is removed from the laminate to form the liquid flow path 4 and the liquid chamber (not shown) as shown in FIG. The means for removing the solid layer 9 is not particularly limited, but specifically, for example, a method in which the solid layer 9 is removed by immersing it in a liquid that dissolves, swells, or peels off is preferable. At this time, if necessary, ultrasonic treatment, spraying, heating, stirring, shaking, pressure circulation, or other removal promoting means can be used.

Examples of the liquid used in the above removing step include halogen-containing hydrocarbon, ketone, ester, aromatic hydrocarbon, ether, alcohol, N-methylpyrrolidone, dimethylformamide, phenol, water, water containing acid or alkali. Etc. A surfactant may be added to these liquids if necessary. From the viewpoint of facilitating the removal, when the positive type dry film is used as the solid layer, it is preferable to irradiate the solid layer with ultraviolet rays, and when other materials are used, the temperature is set to 40 to 60 ° C. as described above. It is preferred to warm the liquid.

After each of the above steps is completed, as shown in FIG. 8, the liquid flow path of the laminated body composed of the structural member 2 in which the substrate 1 and the curable material 10 (see FIG. 6) are cured. Nozzle plate 7 in which discharge ports 7a are formed by an excimer laser or the like corresponding to the liquid flow path 4 on the surface where 4 is exposed
Are aligned and fixed so that the discharge port 7a and the liquid flow path 4 form a continuous passage, and the liquid jet print head (ink jet print head) is completed. In this embodiment, the nozzle plate is fixed to the surface of the laminated body to form the nozzle, but the liquid flow path exposed surface (contact section) of the laminated body can be used as it is as a nozzle. Further, as shown in FIG. 3, a top plate (groove top plate) having a nozzle plate and a groove serving as a liquid flow path is formed on a substrate provided with an electrothermal converter by injection molding. The inkjet print head can also be formed by bonding. In this case, since the grooved top plate is made by molding, even if it is made of a single material, the material is a material limited due to its moldability and liquid contact with ink. In many cases you have to choose from. As such materials, polysulfone, polyether sulfone polyester, polyacetal and the like are generally used.

The surface of the thus obtained ink jet print head on which the ejection port is provided, that is, the ejection port surface is subjected to a water repellent treatment.

The water repellent treatment applied to the discharge port surface, which is a feature of the present invention, will be described below.

The water repellent treatment on the discharge port surface in the present invention is
It is achieved by functionally combining respective materials having excellent water repellency and abrasion resistance. That is, by dispersing the hard fine particles in a desired state in the liquid water repellent agent, the water repellency of the water repellent agent and the abrasion resistance of the hard fine particles can be simultaneously exhibited. As the water repellent used, an alternating copolymer of fluoroolefin and vinyl ether (FEVE), specifically, for example, commercially available Lumiflon (manufactured by Asahi Glass KK), Fluoronate (manufactured by DIC), Cefralcoat (Central) Glass KK),
C-1 (manufactured by Daikin Glass KK), Triflon (manufactured by Mitsui Petrochemical Glass KK), KYNAR-SL / KYNAR-
ADS (manufactured by ATOCHEM); a photoradical polymerization type fluororesin composition comprising a reactive oligomer and a diluting monomer, specifically, for example, commercially available DEFENSA (DI
C); copolymer comb-type fluoropolymer, specifically, for example, commercially available LF-40 (manufactured by Soken Scientific KK); fluorosilicone, specifically, for example, commercially available KP801M (Shin-Etsu Chemical K.K. Perfluorocyclopolymer, specifically, for example, commercially available CYTOP (Asahi Glass KK.
And Teflon AF (manufactured by DUPont). Other than these, it is possible to apply as long as it is liquid and has a high adhesion to the nozzle plate. These water repellents are not limited to liquid ones, and may be gelled ones. However, it is desirable that the hard particles have such a viscosity that they can be uniformly dispersed and held.

Since the hard fine particles to be used are generally of a size in which the ejection port of the liquid jet print head is processed at the μm level, the particle size of the hard fine particles has an upper limit depending on the size. However, in general, the average particle size of the hard particles is preferably about 1 μm or less, more preferably 0.5 μm or less. When the desired particle size cannot be obtained as commercially available hard particles, the particles having a desired particle size can be obtained by pulverizing the hard particles. The hard fine particles used in the present invention are required to have high chemical stability and also to be able to easily achieve the above-mentioned pulverization. From these reasons, inorganic hard fine particles are preferably used. Typical such inorganic hard particles are, for example, silica, alumina, magnesium carbonate, magnesia and the like. Any other person can be used as long as it has characteristics such as hardness that can be used in the peripheral portion of the ejection port of the liquid jet print head.

It is desirable that these inorganic hard fine particles are uniformly dispersed in the peripheral portion of the discharge port. The present inventors have found, through experiments, a state in which the effects of the present invention are effectively exhibited with respect to the dispersion density of the inorganic hard particles. That is, when the dispersion density of the hard fine particles is controlled so that the ink droplets ejected from the ejection port can be held at three or more points, the ink droplets ejected from the ejection port drips from the ejection port to the ejection port surface. Even if attached, air remains in the concave portion of the uneven shape formed on the ejection port surface by the protrusions of the inorganic hard fine particles on the ejection port surface. Due to the presence of the air, the ink droplets do not remain on the ejection port surface and easily flow down from the ejection port surface.

Next, the method of water repellent treatment in the present invention will be described.

First, the hard inorganic fine particles can be dispersed in the water repellent through a means such as a ball mill or a sand mill. However, even if a homogenizer which is inexpensive in equipment cost is used, the object can be sufficiently achieved. You can Dispersion of hard inorganic fine particles in a water repellent is carried out in the same manner as ordinary fine particles are dispersed in a liquid material. For example, a predetermined amount of a water repellent (water repellent resin) to be used is dissolved in an appropriate solvent. Then, a solution having a viscosity that brings about a good dispersion of the hard inorganic fine particles to be used is prepared, and the solution is introduced into the dispersion device, and at the same time, a predetermined amount of the hard inorganic fine particles is introduced therein under stirring them. By mixing with, it is possible to obtain a dispersion liquid in which the hard inorganic fine particles are dispersed in a desired state.

The dispersion liquid prepared as described above is applied to the ejection port surface. The coating method at this time differs depending on the method of forming the ejection port. As a coating method for them, there are a transfer method and a coating method. The former is adopted when the ejection port is formed before the water repellent treatment, and the latter is adopted when the ejection port is formed after the water repellent treatment. Specifically, as the transfer method, a dispersion liquid is applied onto a flexible material such as rubber by a spin coater or the like, and a surface on which an ejection port is formed is pressed against the applied sheet to transfer the dispersion liquid. There is a method, and a method of transferring the dispersion liquid onto the surface on which the ejection port is formed by a flexographic printing machine (Angstromer). When the discharge port is formed by an excimer laser or the like after the water repellent treatment by the above coating method, a coating method such as dip coating or brush coating can be adopted.

After applying the above-mentioned dispersion liquid in this way, the water repellent used is subjected to a predetermined fixing treatment. That is, when a UV-curable water repellent is used, UV irradiation is performed, and when a heat-curable water repellent is used, heat treatment is performed.
When a solvent drying type water repellent is used, heat drying treatment is performed. Thus, the water repellent layer for the liquid jet print head in the state schematically shown in FIG. 10 is formed. Also,
When positively projecting the hard inorganic fine particles from the surface of the layer, the fixing process is stopped midway and the surface of the water repellent layer is dipped in a solvent for the water repellent used or a solvent in which the water repellent can be dissolved. Is slightly dissolved, and then a complete fixing process is performed.
FIG. 11 shows a state where the surface of the water repellent layer shown in FIG. 10 is slightly dissolved. By subjecting the surface of the water repellent treatment layer to dissolution treatment as shown in FIG. 11, it is possible to improve the protrusion density of the hard inorganic fine particles on the layer surface without changing the dispersion density of the hard inorganic fine particles in the resin. . By positively projecting the hard inorganic fine particles in this way, the abrasion resistance and the contact angle of the water repellent layer can be improved.

The experiments conducted by the present inventors will be described below.

(Experiment 1) The inventors of the present invention disclosed in JP-A-4-21.
1959 discloses a problem in the case where a water repellent treatment layer made of a polymer having a fluorine heterocyclic structure contained in the main chain is provided on the ejection port surface of an inkjet print head, that is, regarding the ejection port surface of the print head. In view of the problem caused by insufficient wear resistance,
The possibility of creating a water-repellent treatment layer exhibiting sufficient water repellency and having sufficient durability was examined through experiments. That is, it is determined whether hard particles are dispersed in a predetermined water-repellent resin to form a layer, and whether the layer can contribute to solving the above-mentioned problems in a conventional inkjet printhead. Examined through. Experiment 1-1 below
1 to 7 to realize a desired water repellent treatment layer, the affinity between the water repellent resin and the hard fine particles, the correlation between the viscosity of the resin and the particle size of the hard fine particles, and the formation of the formed layer. The applicability as a water repellent layer on the ejection port surface of the inkjet print head was examined.

Experiment 1-1 Perfluorocyclopolymer (trade name: Cytop CT
-805A, manufactured by Asahi Glass Co., Ltd.) with perfluoro cyclic ether (trade name: CT Solve 100, manufactured by Asahi Glass Co., Ltd.) to make the resin viscosity 20 cps, and the average particle size is 0.1 μm therein.
m fine spherical silica (trade name: S-Quartz H-20
No. 01, manufactured by Nippon Steel Chemical Co., Ltd.) was added and mixed by a homogenizer to prepare a water repellent treatment agent having a mixing ratio of resin and fine particles of 10: 1. Subsequently, a thermoplastic resin polysulfone (trade name UDE) used for a nozzle plate provided on a grooved top plate of an inkjet cartridge (bubble jet cartridge BC-01, manufactured by Canon Inc.)
L) plate has a water-repellent layer with a thickness of 1μ
m of the above water repellent treatment is applied by a coating method, and then, at 100 ° C. for 1 hour in a N ₂ -substituted clean oven.
It was dried for an hour to form a water repellent layer.

Experiment 1-2 A water repellent layer was formed in the same manner as in Experiment 1-1, except that the viscosity of the resin was 100 cps.

Experiment 1-3 Fine particle spherical silica (trade name: S-Quartz H-200
1. Fine spherical silica (trade name: S-Quartz H-200) with an average particle size of 0.8 μm instead of Nippon Steel Chemical Co., Ltd.
No. 8, manufactured by Nippon Steel Chemical Co., Ltd.) was used to form a water repellent layer in the same manner as in Experiment 1-1.

Experiment 1-4 A water repellent layer was formed in the same manner as in Experiment 1-3 except that the viscosity of the resin was 100 cps.

Experiment 1-5 Fine particle spherical silica (trade name: S-Quartz H-200
1. Water repellent layer in the same manner as in Experiment 1-1, except that aluminum oxide fine particles (trade name: Aerosil Aluminum Oxide C, manufactured by Degussa) having an average particle size of 0.5 μm were used in place of Nippon Steel Chemical Co., Ltd.) Was formed.

Experiment 1-6 Fine particle spherical silica (trade name: S-Quartz H-200
1. Magnesia U-3 fine particles with an average particle size of 0.8 μm (trade name: magnesia U-3) instead of Nippon Steel Chemical Co., Ltd.
0, manufactured by Ube Chemical Co., Ltd.) was used to form a water repellent layer in the same manner as in Experiment 1-1.

Experiment 1-7 Experiment 1 was repeated except that the water repellent agent obtained by removing fine particle spherical silica (trade name: S-Quartz H-2001, manufactured by Nippon Steel Chemical Co., Ltd.) from the water repellent agent of Experiment 1-1 was used. A water repellent treatment layer was formed in the same manner as in -1.

With respect to each of the water-repellent treated layers obtained as described above, the dispersion state of the fine particles, the fine particle distribution density and the contact angle on the surface of the water-repellent treated layer were evaluated by the methods described below.

(1) Dispersion state of fine particles: The dispersion state of fine particles in the water-repellent treatment layer of the plate subjected to the water-repellent treatment was examined. That is, first, a water repellent treatment agent containing fine particles was sampled and observed with a microscope, and the dispersion state of the fine particles immediately after being dispersed was examined. further,
In order to confirm whether or not the dispersed state could be maintained until the fixing was completed, the dispersed state in the fine particles was similarly examined at the time of leaving for 1 hour without fixing. The evaluation was performed according to the following criteria. That is, the one that is evenly distributed over almost the entire circle is ○, but it is not completely evenly dispersed.
From the viewpoint of water repellency unevenness, the one that does not cause any particular problem was evaluated as Δ, and the one in which uniform dispersion was not obtained and the water repellency became uneven was evaluated as x. The evaluation results are shown in Table 1.

(2) Fine particle distribution density on the surface of the water repellent treatment layer:
From the viewpoint of examining the dispersed state of the fine particles after fixing, the distribution density of the fine particles on the surface of the water-repellent treatment layer was examined. That is, a microscopic photograph of a water-repellent plate was taken, and as shown in FIG. 9, 100 fine particles visible on the surface of the photograph were randomly selected as a sample,
The center-to-center distance d between the microparticles closest to each sample microparticle and the sample microparticles was measured, and this was taken as the distribution density of the microparticles on the surface of the water repellent treatment layer. The evaluation results are shown in Table 1. Here, the narrower the range of the distance d between the centers of the fine particles, the smaller the variation in the distribution density of the fine particles,
It can be said that the dispersion state of the fine particles is good.

(3) Contact angle (initial contact angle, contact angle after rubbing): In order to investigate the water repellency of the water repellent treatment layer, the (advancing) contact angle of the water repellent treatment layer was manufactured by Kyowa Interface Science Co., Ltd. 10 or more measurements were performed using a contact angle meter CA-D. The results are shown in Table 1. As the measuring ink, an ink for bubble jet cartridge BC-01 (manufactured by Canon Inc.) was used. In general, it is known that the larger the contact angle, the more difficult the ink is to adhere, the better the water repellency, and the better the printing can be obtained. Here, the initial contact angle and the contact angle after rubbing were measured for the purpose of evaluating wear resistance. Possible causes of deterioration of the contact angle include (i) chemical deterioration of the water-repellent resin and (ii) partial exfoliation of the water-repellent resin or fine particles. The initial contact angle indicates the measurement result for the unused state. The contact angle after rubbing is the result measured after rubbing the water-repellent layer with the durability tester 3000 times.

[0063]

[Table 1] The results shown in Table 1 revealed the following.

That is, in the case of containing fine particles, the deterioration of the contact angle is remarkably reduced as compared with the conventional case in which the fine particles are not contained. Therefore, by containing fine particles, the abrasion resistance of the water repellent agent is improved. It is understood that it will improve. Also,
It has been found that there are some water-repellent treatment agents containing fine particles that do not exhibit the water-repellent performance sufficiently. That is,
Regarding the water-repellent treated layers of Experiments 1-4 and 1-6, it was found that ink tended to collect on the surface where ink was present. When actually applied to the ejection port surface of the recording head, this phenomenon is not preferable because the aggregated ink adversely affects ejected ink droplets. It is considered that the above phenomenon occurs because of the variation in contact angle. That is, the fact that the contact angles vary on the same surface leads to uneven water repellency. If the water repellency is uneven, a relatively hydrophilic portion and a hydrophobic portion are formed on the ejection port surface. In this experiment, it was found that it is the dispersion state of the fine particles on the layer surface that causes the variation in the contact angle. When the fine particles are non-uniformly dispersed, the mixing ratio of the fine particles and the resin greatly differs depending on the place. Therefore, in the portion where the fine particles are aggregated, the water-repellent resin is less than in other portions, so that the water repellency becomes uneven. In such a state, no matter how much the water repellency is improved as a whole, the ink will be concentrated on the part having poor water repellency.
As a result, the water-repellent performance of the entire water-repellent layer is deteriorated. Therefore, the dispersion state of the fine particles in the water-repellent treatment layer is preferably such that water-repellent unevenness does not occur on the surface of the water-repellent treatment layer, that is, the fine particles are almost uniformly dispersed in the water-repellent treatment layer. .

Focusing on the particle size of the particles, the viscosity of the water-repellent resin, and the affinity between the resin and the particles, the particle size of the particles is
As described above, the particle size (desirably 0.5 μm or less) that does not affect the ejection is set in consideration of the opening area of the ejection port. It was found that a good dispersion state can be obtained by combining fine particles. Therefore, in the subsequent experiment (that is, Experiment 2), the experiment was performed under this condition. In addition, of the combination of fine particles and resin,
In the combination of perfluorocyclopolymer and magnesium oxide, the result is that the dispersion state is not very preferable, but this is because the affinity between perfluorocyclopolymer and magnesium oxide is insufficient. Conceivable.

(Experiment 2) Main Experiment (Experiments 2-1 to 2-1)
In 8), based on the findings found in Experiment 1, various types of water repellent treatment agents were prepared by selecting and combining water repellent resin and fine particles, and used for surface treatment of the ejection port surface of the liquid jet print head. It was applied to prepare a liquid jet print head, and the print head was operated to observe the water repellency and abrasion resistance in printing, and the usefulness of the water repellent treatment agent was considered.

Experiment 2-1 Perfluorocyclopolymer (trade name: Cytop CT
-805A, manufactured by Asahi Glass Co., Ltd.) with perfluoro cyclic ether (trade name: CT Solve 100, manufactured by Asahi Glass Co., Ltd.) to make the resin viscosity 20 cps, and the average particle size is 0.1 μm therein.
m fine particle spherical silica (trade name: H-2001, manufactured by Nippon Steel Chemical Co., Ltd.) was added and mixed by a homogenizer to prepare a water repellent treatment agent having a mixing ratio of resin and fine particles of 10: 1. Then, an inkjet cartridge (bubble jet cartridge BC-01,
Thermoplastic resin polysulfone (trade name: UDEL) manufactured by Canon Inc. has a grooved top plate provided on a grooved top plate, and the water-repellent treatment layer has a dry thickness of 1 μm on the discharge port surface of the nozzle plate.
An amount of the water repellent treatment agent of m was applied. Then, the water-repellent layer was fixed by drying at 100 ° C. for 1 hour in a N ₂ -substituted clean oven. Next, KrF (λ = 248n
m) Excimer laser (trade name: INDEX200K,
1.5 J / cm on the machined surface by Lumonics)
1000μm under the condition of ²・ pulses × 200pulses
^By opening 70 discharge ports with an opening area of ² ,
A nozzle for a liquid jet print head having a water repellent material layer in which inorganic fine particles are almost uniformly dispersed in the peripheral portion of a discharge port is completed. Further, a liquid jet print head substrate on which the prepared electrothermal converter was formed was joined to the grooved top plate to produce a liquid jet print head.

Experiment 2-2 As a water repellent treatment agent, a photo-radical polymerization type fluororesin (trade name: DEFENSA7710, manufactured by DIC), xylene / methyl isobutyl ketone, fine particle spherical silica (trade name: H-2001, Nippon Steel Chemical Co., Ltd.) A liquid jet print head was produced in the same manner as in Experiment 2-1 except that the mixture of

Experiment 2-3 As a water repellent agent, a mixture of FEVE (trade name: Lumiflon, manufactured by Asahi Glass Co., Ltd.), xylene / methyl isobutyl ketone, and fine spherical silica (trade name: H-2001, manufactured by Nippon Steel Chemical Co., Ltd.). A liquid jet print head was produced in the same manner as in Experiment 2-1 except that the above was used.

Experiment 2-4 As a water repellent agent, fluorosilicone (trade name: KP-8
01, manufactured by Shin-Etsu Chemical Co., Ltd.), xylene / methyl isobutyl ketone, and fine particle spherical silica (trade name: H-2001, manufactured by Nippon Steel Chemical Co., Ltd.)
A liquid jet print head was manufactured in the same manner as in 1.

Experiment 2-5 Liquid jet printing was performed in the same manner as Experiment 2-1 except that aluminum oxide (trade name: Aerosil Aluminum Oxide C, manufactured by Degussa) was used in place of the fine particle spherical silica (H-2001). A head was produced.

Experiment 2-6 Fine particles Liquid was obtained in the same manner as in Experiment 2-1 except that magnesium oxide fine particles (trade name: Magnesia U-30, manufactured by Ube Chemical Co., Ltd.) were used in place of the spherical silica (H-2001). A jet print head was made.

Experiment 2-7 Fine particle spherical silica (H-2001) instead of brass powder (trade name: No. 7700, Fukuda Metal Foil & Powder Co., Ltd.)
A liquid jet print head was produced in the same manner as in Experiment 2-1 except that the same was used.

Experiment 2-8 Fine particle spherical silica (H-2
Experiment 2 except that the water repellent agent except 001) was used
A liquid jet print head was manufactured in the same manner as in -1.

Experiment 2-9 Perfluorocyclopolymer (CYTOP CT-805
Fluorosilicone (trade name: KP801) instead of A)
M, manufactured by Shin-Etsu Chemical Co., Ltd.) was used to prepare a liquid jet print head in the same manner as in Experiment 2-8.

Experiment 2-10 Perfluorocyclopolymer (trade name: Cytop CT
-805A, manufactured by Asahi Glass Co., Ltd.) with perfluoro cyclic ether (trade name: CT Solve 100, manufactured by Asahi Glass Co., Ltd.) to make the resin viscosity 20 cps, and the average particle size is 0.1 μm therein.
m fine particle spherical silica (trade name: H-2001, manufactured by Nippon Steel Chemical Co., Ltd.) was added and mixed by a homogenizer to prepare a water repellent treatment agent in which the mixing ratio of the resin and the fine particles was 10: 1.
Subsequently, a discharge port of a nozzle plate provided on a grooved top plate made of a thermoplastic resin polysulfone (trade name UDEL) for an ink jet cartridge (bubble jet cartridge BC-01, manufactured by Canon Inc.) formed by a conventional method. A water-repellent treatment agent was applied to the surface in an amount such that the thickness of the water-repellent treatment layer was 1 μm in a dry state, and the material was dried until the tackiness was lost. Next, the nozzle material thus obtained is immersed in perfluoro cyclic ether (CT Solve 100) to dissolve and remove the resin of the matrix until about half of the inorganic fine particles on the outermost surface are exposed, and then completely dried. It was Finally, a discharge port was opened by an excimer laser to complete a nozzle for a liquid jet print head in which some of the inorganic fine particles were projected from the surface of the water repellent material layer. Further, a liquid jet print head substrate on which the prepared electrothermal converter was formed was joined to the grooved top plate to produce a liquid jet print head.

Experiment 2-11 Perfluorocyclopolymer (CYTOP CT-805
Fluorosilicone (trade name: KP801) instead of A)
M, manufactured by Shin-Etsu Chemical Co., Ltd.), and a liquid jet print head was manufactured in the same manner as in Experiment 2-10.

Experiment 2-12 Perfluorocyclopolymer (trade name: Cytop CT
-805A, manufactured by Asahi Glass Co., Ltd. 60 parts, fluorosilicone (trade name: KP801M, manufactured by Shin-Etsu Chemical Co., Ltd.) 40 parts, perfluoro cyclic ether (trade name: CT Solve 100, manufactured by Asahi Glass Co., Ltd.) 100 parts, fine spherical silica (product) Name: H-20
01, manufactured by Nippon Steel Chemical Co., Ltd.) was mixed with a homogenizer to obtain a water repellent treatment agent. Subsequently, the water repellent treatment agent was transferred to the peripheral portion of the ejection port of the ejection element of the prepared bubble jet printer BJC820J (manufactured by Canon Inc.). The transfer was performed by applying the above water repellent agent to a silicon rubber disk with a spin coater and pressing a discharge element mounted on a jig using a hand press. Next, the transferred ejection element is dried / cured at 150 ° C. for 1 hour in a clean oven in which N _{2 is} substituted, and a liquid jet print head having a water repellent material layer in which inorganic fine particles are dispersed in the peripheral portion of the ejection port. Completed the nozzle for. Furthermore, a liquid jet printhead substrate having an electrothermal converter formed thereon was joined to the grooved top plate to produce a liquid jet printhead.

Experiments 2-13 to 18 A liquid jet print head was prepared in the same manner as Experiment 2-1 except that the mixing ratio of the water repellent resin of the water repellent agent and the fine particles in Experiment 2-1 was changed.

For each of the liquid jet print heads obtained by the above experiment, the dispersion (surface protrusion) density of fine particles, the ink contact angle, the adhesion to the nozzle plate, and the abrasion resistance were measured or evaluated by the methods described below. did.

(1) Distribution of fine particles (surface protrusion) density: The distribution density of the surface of the water repellent treatment layer was examined in order to investigate the dispersion state after the water repellent treatment layer was fixed. That is, as shown in FIG. 9, a microscopic photograph of the water-repellent discharge port surface is taken,
100 fine particles visible on the surface are randomly selected as a sample, the center-to-center distance d between the fine particles closest to each sample fine particle and the sample fine particles is measured, and the obtained value is used as the surface of the water-repellent treatment layer. The distribution density of fine particles in The results are shown in Table 2. Here, the narrower the range of the center-to-center distance of the fine particles, the smaller the variation in the distribution density of the fine particles, and it is judged that the fine particles are dispersed well.

(2) Ink contact angle: In order to investigate the water repellency of the ejection port surface of a liquid jet print head, the (advance) contact angle of the recording head was measured with a contact angle meter CA-D manufactured by Kyowa Interface Science Co., Ltd. Used to make measurements. The results are shown in Table 2. The ink for the bubble jet cartridge BC-01 (manufactured by Canon Inc.) was used as the measuring ink. In general, it is known that the larger the contact angle, the more difficult the ink is to adhere, the better the water repellency, and the better the printing can be obtained. Here, the initial contact angle and the contact angle after the test were measured for the purpose of catching the deterioration of water repellency with time. Factors causing the contact angle to deteriorate are (i) the water-repellent resin is chemically deteriorated. (Ii) It is conceivable that a part of the water-repellent resin or the fine particles may come off. The initial contact angle shows the measurement result of the liquid jet print head in an unused state. The post-test contact angle refers to the result measured after the liquid jet print head has been subjected to the abrasion resistance test described below.

(3) Adhesion: The adhesion and hardness of the water repellent layer of the liquid jet print head were examined. That is, the liquid jet print head is attached to the bubble jet cartridge BC-0.
After immersing it in ink for 1 (manufactured by Canon Inc.) at 60 ° C. for 1 month, it was washed with pure water, dried and subjected to a tape peel test. As the tape, Scotch810 manufactured by Sumitomo 3M Limited was used. The reason for conducting the test under such conditions is as follows. The water repellent treatment agent on the periphery of the ejection port is always in a state where it is easy to come into contact with the ink held as a meniscus at the ejection port. If such a state continues for a long period of time, a chemical change or swelling due to the ink occurs at the peripheral portion of the ejection port of the water repellent agent, and peeling easily occurs. Therefore, in order to understand the peeling by the ink as accurately as possible, the test is performed under the above-mentioned conditions. The evaluation was carried out on the basis of ◯ when peeling did not occur, Δ when the water repellent or particles partially peeled off but there was no problem in performance, and X when clear peeling was confirmed. The results are shown in Table 2.

(4) Surface state of the discharge port surface: When the discharge port surface or the cleaning blade is covered with dust or dust, or when the paper comes into contact with the discharge port surface due to poor conveyance, etc. May be scratched. Especially when the hardness of the water repellent agent is low, this scratch is likely to occur. Since the water-repellent layer is damaged in this way, the water-repellent property is reduced in that part, and therefore the water-repellent unevenness is generated on the ejection port surface. Due to the unevenness of the water repellency, the ink is likely to collect on the portion where the water repellency is lowered, and the water repellency of the entire ejection port surface is lowered. Therefore, the state of occurrence of scratches on the discharge port surface was evaluated by observing the discharge port surface with a microscope after performing a wear resistance test of the liquid jet print head described later. The evaluation is based on the criteria that ○ indicates that no scratch was found on the discharge port surface in any of the tests, △ indicates that some scratches were found in some tests, and × indicates that many scratches were found. went. The results are shown in Table 2.
Shown in.

(5) Abrasion resistance: In order to examine the abrasion resistance of the water-repellent treatment layer provided on each liquid jet print head by the cleaning blade, the blade wiping durability test was conducted with a bubble jet equipped with each liquid jet print head. A printer BJ10V (manufactured by Canon Inc.) was used (however, a bubble jet printer BJC820J (manufactured by Canon Inc. was used for the liquid jet recording head obtained in Experiment 2-12) in the following mode. went. That is, (i) preliminary ejection in the cap, (ii) carriage reciprocation,
(Iii) The blade was wiped and the above modes were repeated 5000 times and 15000 times. Bubble jet printer BJ10
The blade material of V was H-NBR and had a thickness of 0.6 mm, and the blade material of bubble jet J printer BJ820J was ether polyurethane and had a thickness of 0.7 mm. In order to clean the discharge port surface, the ink is usually sucked from the discharge with a pump so that the adhered ink, dust, etc. can be easily removed, and then wiped with a blade.
If the pump is omitted, it is necessary to perform cleaning with a stronger blade wiping pressure than before. In this evaluation, in order to produce a strong blade wiping pressure, the blade thickness was set to 2 of the normal thickness.
Double the number of times and perform 5000 times and 15,000 times in the same manner. For the evaluation, 100 liquid ejection print heads were obtained for which good printing was obtained in the print evaluation pattern after the recording head was created, for each blade thickness, and the aforementioned durability test was performed on each liquid ejection print head. Then, the number of heads causing print failure was checked in a print test. The evaluation results are shown in Table 2. In the printing test, a printing failure was considered when the following failure modes occurred. That is, white stripes are generated: specific nozzles are not ejected, or inks ejected from the specific nozzles are changed in the vertical direction. Ruled line deviation: Inks ejected from the specific nozzles are deflected in the left and right directions.
Splash: Fine ink dots appear around the landing dots, causing fine ink to scatter due to instability in ejection. Mura (light and dark streak): The ink ejected from a specific nozzle is slightly deflected vertically during solid printing. Unevenness is seen in the image, unevenness (marbling): irregular ejection nozzles appear during solid printing, and the solid portion looks like marbling meat.

(6) Comprehensive Evaluation Further, the evaluation items (1) to (5) above were comprehensively evaluated and evaluated. The evaluation criteria here were as follows. That is, ⊚ for all items, ∘ for some items, but not for practically satisfactory level, ○, with some performance problems but no problem at conventional level Those having a problem with performance were evaluated as Δ, and those having a problem in performance were evaluated as ×. The results are shown in Table 2.

A liquid ejecting printing apparatus equipped with the liquid ejecting print head used in the above evaluation will be described below.

FIG. 1 is an external perspective view showing an example of a liquid jet printing apparatus (IJRA) in which a liquid jet print head is mounted as an ink jet head cartridge (IJC).

In FIG. 1, reference numeral 20 is an ink jet head cartridge (IJC) provided with a group of nozzles for ejecting ink in opposition to the recording surface of the recording paper fed onto the platen 24. Reference numeral 16 denotes a carriage (HC) holding an IJC 20, which is connected to a part of a drive belt 18 which transmits a driving force of a drive motor 17 and slides with two guide shafts 19A and 19B arranged in parallel with each other. By being movable, the reciprocating movement over the entire width of the recording paper of the IJC 20 becomes possible.

26 is a head recovery device, which is an IJC 20
Is arranged at one end of the movement path of, for example, at a position facing the home position. The drive force of the motor 22 via the transmission mechanism 23 causes the head recovery device 26 to operate, and
Cap the JC 20. In association with the capping of the IJC 20 by the cap portion 26A of the head recovery device 26, a discharge recovery process such as removing the thickened ink in the nozzle by forcibly discharging the ink from the discharge port (idle discharge) is performed. To do. Also, the IJC 20 is protected by capping at the end of printing.

Reference numeral 30 denotes a blade as a wiping member, which is disposed on the side surface of the head recovery device 26 and is made of silicon rubber. The blade 30 is a blade holding member 3
The head recovery device 2 is held at 0A in a cantilever form.
Similar to 6, it is operated by the motor 22 and the conduction mechanism 23 and can be engaged with the ejection surface of the IJC 20. As a result, the blade 30 is projected into the movement path of the IJC 20 at an appropriate timing in the print operation of the IJC 20 or after the ejection recovery process using the head recovery device 26, and the IJC 20 is moved along with the movement operation of the IJC 20.
It removes dew condensation, wetting, dust or the like on the ejection surface of 20.

[0092]

[Table 2]

[0093]

[Table 3] The results shown in Table 2 revealed the following.

Regarding the distribution of the fine particles, there are variations in the distribution density between the one using brass powder as the fine particles and the one containing a small amount of silica. This is presumably because the particles containing silica had an excessively small amount of fine particles, and the particles using brass powder had variations in the particle size of the brass powder itself.

Regarding the contact angle, the particles containing fine particles at the initial contact angle are slightly improved as compared with those containing no particles. Among them, the one in which the fine particles were positively projected on the surface was particularly improved in the contact angle. This improvement in the contact angle is due to the unevenness formed on the surface of the water repellent treatment layer by the fine particles, and the inclination angle of the uneven surface with respect to the nozzle plate surface is added to the contact angle of the water repellent material layer itself. As a result, it is considered that the relative contact angle with respect to the layer surface was improved. Regarding the contact angle after the test, the attenuation of the contact angle when the blade thickness is doubled is small in the case of containing fine particles. It is considered that this is because the hardness of the water repellent material layer was improved and the peeling and abrasion of the water repellent layer were reduced.

Regarding the adhesiveness, the mixing ratio of the one using the photo-radical polymerization type fluororesin as the water repellent resin (Experiment 2-2), the one using magnesium oxide as the fine particles (Experiment 2-6) and the mixing ratio of silica was 100. : 20 or more (Experiment 2-1
7 to 18), some particles were peeled off. It is considered that the former two cases are due to the poor affinity between the resin and the fine particles, and the other cases are due to the content of the fine particles.

Regarding the surface condition of the ejection port surface of the head,
In the case of containing fine particles, the ejection port surface of the head is less likely to be scratched. It should be noted that some scratches were found when the blade thickness was doubled in the case of using the radical photopolymerizable fluororesin as the water-repellent resin and the case of using brass powder for the fine particles because the hardness of the water-repellent resin or fine particles was found. It seems to be caused by a shortage. In addition, discoloration that was considered to be due to corrosion was observed after the test in the case of using brass powder.
Further, in the case of not containing fine particles, many scratches were found especially when the blade thickness was twice.

Regarding the abrasion resistance, the water-repellent treatment agent containing fine particles has a reduced number of defective print heads as compared with the water-repellent treatment agent which does not contain fine particles in both the normal blade thickness and when the blade thickness is twice. There is. Especially when the blade thickness is double, the number of defective print heads is drastically reduced. From this, it is understood that the wear resistance of the water repellent treatment is improved by containing the fine particles. Furthermore, Experiments 2-1 and 2-12 to 1
In the case where the mixing ratio of the water-repellent resin and the fine particles is changed in 9, the mixing ratio of the resin and the fine particles is 100: 5.
With the following and 100: 50 or more, the number of print defective heads is large. This has a mixing ratio of 100:
It is considered that when the number of particles is 5 or less, the water-repellent layer cannot have sufficient abrasion resistance because the content of fine particles is small. In addition, it is considered that when the mixing ratio is 100: 50 or more, the content of the fine particles is too large and the crosslink density of the water-repellent resin is lowered to deteriorate the adhesiveness. It should be noted that many of the print heads with poor printing appear in the ones containing brass powder as fine particles, which is considered to be due to the brass powder being corroded by the ink.

Consideration will be made based on the findings described above and the results of the comprehensive evaluation.

As is clear from the results shown in Table 2, the liquid jet print head subjected to the water repellent treatment of the present invention, that is, the water repellent treatment in which the inorganic fine particles are contained in the water repellent treatment agent has a good overall performance. Indicates. In particular, even when the suction recovery mechanism is omitted and the wiping pressure of the cleaning blade is made stronger than ever, it exhibits excellent wear resistance. This is considered as follows. That is, the dispersed hard fine particles receive the blade against the blade pressed strongly and soften the contact with the water-repellent resin, so that the resin is not easily scratched. In particular, when the fine particles are positively projected, the above-mentioned effects are remarkable. Further, the water repellency of the ejection port surface, which influences the ejection stability (print quality), also becomes rough due to the inclusion of fine particles, and the contact angle becomes large. In particular, in the case where the fine particles are positively projected, an air layer is formed in the space between the fine particles, and the contact angle is further increased. Surprisingly, the incorporation of such fine particles not only improves wear resistance but also water repellency is an unexpected effect.

Furthermore, it is understood that the strength of the water-repellent layer shows a good value when the inorganic fine particles are made of a material such as silica or aluminum oxide, particularly when the surface is made to project. It is considered that this is because the material such as silica or aluminum oxide itself has a relatively porous structure, and therefore the resin enters the porous structure, which improves the adhesion and the contact angle. .

From the above results, as described above, according to the water repellent treatment of the present invention, the ejection port surface of the liquid jet print head can be made excellent in abrasion resistance and water repellency, and is always stable. It is understood that the desired liquid jet printhead can be obtained which is ejected to provide high quality records. In Experiment 2, those belonging to the present invention were obtained in Experiments 2-1, 3, 5, 10, 12, and 14 to 16, and in terms of comprehensive performance as a water repellent treatment agent. More preferable are Experiment 2-1 and Experiment 2-1.
It was obtained at 0.

The present invention is particularly effective in an ink jet printing type print head and a printing apparatus for recording by forming flying droplets by utilizing thermal energy among the ink jet printing types. .

Regarding its typical structure and principle, see, for example, US Pat. Nos. 4,723,129 and 4740.
No. 796, the present invention is preferably carried out using these basic principles. This printing method can be applied to both so-called on-demand type and continuous type.

The print recording method will be briefly described below.
It seems that the electrothermal converter arranged corresponding to the sheet or liquid path holding the liquid (ink) exceeds the nucleate boiling phenomenon in the liquid (ink) corresponding to the recorded information and causes the film boiling phenomenon. By applying at least one driving signal for giving a rapid temperature rise, thermal energy is generated and film boiling occurs on the heat acting surface of the recording head.
In this way, bubbles can be formed in one-to-one correspondence with the drive signal applied from the liquid (ink) to the electrothermal converter, which is particularly effective for the on-demand recording method. Due to the growth and contraction of the bubbles, the liquid (ink) is ejected through the ejection port to form at least one droplet. It is more preferable to make the driving signal into a pulse shape because bubbles can be grown and contracted immediately and appropriately, and thus a liquid (ink) with excellent responsiveness can be ejected. This pulse-shaped drive signal is described in US Pat.
Those described in 345262 are suitable. If the conditions described in US Pat. No. 4,313,124, which is an invention relating to the rate of temperature rise on the heat acting surface, are adopted, more excellent recording can be performed.

The structure of the print head is the combination of a discharge port, a liquid flow path, and an electrothermal converter as disclosed in the above-mentioned specifications (straight liquid flow path or right-angled liquid flow path). In addition, as disclosed in US Pat. No. 4,558,333 and US Pat. No. 4,459,600,
The present invention also includes a structure in which the heat acting portion is arranged in the bending region.

In addition, Japanese Patent Laid-Open No. 123670/1984 discloses a structure in which a common slit is used as a discharge port of the electrothermal converter for a plurality of electrothermal converters, and a pressure wave of thermal energy is absorbed. The present invention is also effective in a configuration based on Japanese Patent Laid-Open No. 138461/1984 which discloses a configuration in which the corresponding opening corresponds to the ejection portion.

Further, as a print head in which the present invention is effectively used, there is a full line type print head having a length corresponding to the maximum width of the recording medium which can be recorded by the printing apparatus. This full line head has a full line configuration by combining a plurality of print heads as disclosed in the above specification,
It may be a single full line printhead formed integrally.

In addition, by being attached to the apparatus main body, it can be electrically connected to the apparatus main body and can be supplied with ink from the apparatus main body by a replaceable chip type print head or the print head itself. The present invention is also effective when a cartridge-type print head provided specially is used.

Further, it is preferable to add recovery means for the print head, preliminary auxiliary means, etc. to the printing apparatus of the present invention because the printing apparatus of the present invention can be made more stable. Specific examples thereof include capping means, pressurizing or suctioning means, electrothermal converters or other heating elements for the print head, or preheating means using a combination thereof, recording. It is also effective to perform stable recording by adding a means for performing a preliminary ejection mode for performing ejection different from the above.

Further, the printing mode of the printing apparatus is not limited to the mode in which only the mainstream color such as black is recorded, and either the print head may be integrally formed or a plurality of print heads may be combined. However, the present invention is extremely effective for an apparatus provided with at least one of a multicolor of different colors or a full color by color mixing.

In the embodiments of the present invention described above, the liquid ink is used for explanation. However, in the present invention, either an ink which is solid at room temperature or an ink which is in a softened state at room temperature is used. Can be used. In the above-mentioned inkjet printing device, the ink itself is kept at 30 ° C or higher.
Since it is common to adjust the temperature within a range of 0 ° C. or less to control the temperature of the ink so that the viscosity of the ink is within a stable ejection range, it is sufficient that the ink is in a liquid state when a use recording signal is applied.

In addition, the excessive temperature rise of the head or ink due to thermal energy is positively prevented by using it as the energy of the state change of the ink from the solid state to the liquid state, or the evaporation of the ink is prevented. It is also possible to use an ink that solidifies when left as it is. In any case, liquefaction occurs only when heat energy is applied, such as when the ink is liquefied by applying heat energy according to the recording signal and ejected as an ink liquid, or when it begins to solidify when it reaches the recording medium. The use of an ink having such a property is also applicable to the present invention. Such an ink is in the state of being held as a liquid or a solid in the recesses or through holes of the porous sheet as described in JP-A-54-56847 or JP-A-60-71260. Alternatively, it may be configured to face the electrothermal converter.

In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

[0115]

Since the present invention is configured as described above, it has the following effects.

The liquid jet print head of the present invention is provided with a water repellent material layer in which inorganic fine particles are dispersed in a water repellent resin on the ejection port surface, so that the ejection port surface is excellent in abrasion resistance and water repellency. The discharge stability of the ink can be improved. Further, by intermittently projecting the inorganic fine particles in the water-repellent resin onto the surface of the water-repellent material layer, the contact angle with the ink is improved, and the ink ejection stability can be further improved.

The liquid jet printing apparatus of the present invention is
Since the liquid jet print head of the present invention is provided, stable ink ejection is performed, and high-quality recording is performed even when the suction recovery mechanism is omitted or high-speed recording that ejects ink 10,000 times or more per second. You can

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an example of a liquid jet printing apparatus including a liquid jet print head of the present invention.

FIG. 2 is a schematic perspective view showing an example of a liquid jet print head of the present invention.

FIG. 3 is a process explanatory view showing a process of providing an electrothermal converter on a substrate in the manufacturing process of the liquid jet print head shown in FIG.

4A to 4C are process explanatory views showing a process of stacking a solid layer on a site where a liquid flow path and a liquid chamber are to be formed in the manufacturing process of the liquid jet print head shown in FIG.

5 is a cross-sectional view taken along the line AA shown in FIG.

6A to 6C are process explanatory views showing a process of laminating and curing a curable material on a solid layer in the manufacturing process of the liquid jet print head shown in FIG.

7A to 7C are process explanatory views showing a process of removing a solid layer from the laminated body in the manufacturing process of the liquid jet print head shown in FIG.

8A to 8C are process explanatory views showing a process of joining a nozzle plate to a laminated body in the manufacturing process of the liquid jet print head shown in FIG.

FIG. 9 is a diagram for explaining a dispersed state of fine particles in the water repellent treatment layer of the present invention.

FIG. 10 is a schematic cross-sectional view showing a water repellent layer of the present invention.

11 is a schematic cross-sectional view showing a state in which the surface of the water repellent treatment layer shown in FIG. 10 is partially dissolved.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base 2 Structural member 3 Electrothermal converter 4 Liquid flow path 5 Liquid chamber 6 Supply port 7 Discharge port plate (nozzle plate) 7a Discharge port 7b Discharge port surface 9 Solid layer 10 Curing material 16 Carriage (HC) 17 Drive motor 18 Drive Belt 19A, 19B Guide Shaft 20 Inkjet Head Cartridge (IJC) 22 Motor 23 Transmission Mechanism 24 Platen 26 Head Recovery Device 26A Cap Part 30 Blade 30A Blade Holding Member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeo Tono 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Masatsune Kobayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Within the corporation

Claims (28)

[Claims] 1. A discharge port for discharging a recording liquid,
In a liquid jet print head including an energy generating element that generates energy that causes ejection of the liquid through the ejection port, inorganic fine particles are contained in a water-repellent resin on the ejection port surface where the ejection port is arranged. A liquid-jet printhead, comprising a water-repellent material layer which is dispersed in a desired state. 2. The water-repellent resin is an alternating copolymer of full olefin and vinyl ether, a photo-radical polymerization type fluororesin composition comprising a reactive oligomer and a diluting monomer, a copolymerization type comb-type fluoropolymer, fluorosilicone, The liquid jet printhead of claim 1 selected from perfluorocyclopolymers. 3. The liquid jet print head according to claim 1, wherein the inorganic fine particles are selected from silica, alumina, and magnesia. 4. The liquid jet print head according to claim 1, wherein the energy generating element is an electrothermal converter. 5. The liquid jet print head according to claim 1, wherein the inorganic fine particles are in a substantially uniformly dispersed state. 6. The average particle size of the inorganic fine particles is 1.0 μm.
The liquid jet printhead of claim 1, wherein: 7. The average particle diameter of the inorganic fine particles is 0.5 μm.
The liquid jet printhead of claim 6, wherein: 8. An ejection port for ejecting a recording liquid,
In a liquid jet print head including an energy generating element that generates energy that causes ejection of the liquid through the ejection port, inorganic fine particles are contained in a water-repellent resin on the ejection port surface to which the ejection port is connected. It consists of things that are dispersed in a desired state,
A liquid jet print head comprising a water repellent material layer on the surface of which the fine particles are intermittently projected. 9. The water-repellent resin is an alternating copolymer of full olefin and vinyl ether, a photo-radical-polymerizable fluororesin composition comprising a reactive oligomer and a diluting monomer, a copolymer-type comb fluoropolymer, fluorosilicone, The liquid jet printhead of claim 8 selected from perfluorocyclopolymers. 10. The inorganic fine particles are silica, alumina,
The liquid jet print head according to claim 8, which is selected from magnesia. 11. The liquid jet print head according to claim 8, wherein the energy generating element is an electrothermal converter. 12. The liquid jet print head according to claim 8, wherein the inorganic fine particles are in a substantially uniformly dispersed state. 13. The average particle size of the inorganic fine particles is 1.0 μm.
The liquid jet print head according to claim 8, wherein the liquid jet print head has a thickness of m or less. 14. The average particle diameter of the inorganic fine particles is 0.5 μm.
The liquid jet print head according to claim 13, wherein the liquid jet print head has a thickness of m or less. 15. A liquid jet recording head comprising: a discharge port for discharging a recording liquid; and an energy generating element for generating energy for causing the liquid to be discharged through the discharge port, and the liquid jet recording. In a liquid jet printing apparatus including a drive signal supply unit for supplying a drive signal to the energy generating element of the head, inorganic fine particles in a water-repellent resin are in a desired state on a discharge port surface where the discharge port is provided. 2. A liquid-jet printing apparatus, wherein a water-repellent material layer composed of a material dispersed in 1. is provided. 16. The water-repellent resin is an alternating copolymer of full olefin and vinyl ether, a photoradical polymerization type fluororesin composition comprising a reactive oligomer and a diluting monomer, a copolymerization type comb-type fluoropolymer, fluorosilicone, 16. A selection from among perfluorocyclopolymers.
The liquid jet printing apparatus according to item 1. 17. The inorganic fine particles are silica, alumina,
The liquid jet printing apparatus according to claim 15, which is selected from magnesia. 18. The liquid jet printing apparatus according to claim 15, wherein the energy generating element is an electrothermal converter. 19. The liquid jet printing apparatus according to claim 15, wherein the inorganic fine particles are in a substantially uniformly dispersed state. 20. The average particle size of the inorganic fine particles is 1.0 μm.
The liquid jet printing apparatus according to claim 15, wherein the liquid jet printing apparatus has a thickness of m or less. 21. The average particle diameter of the inorganic fine particles is 0.5 μm.
The liquid jet printing apparatus according to claim 20, wherein the liquid jet printing apparatus has a thickness of m or less. 22. A liquid jet recording head comprising: a discharge port for discharging a recording liquid; and an energy generating element for generating energy that causes the liquid to be discharged through the discharge port, and the liquid jet recording. In a liquid jet printing apparatus including a drive signal supply unit for supplying a drive signal to the energy generating element of the head, inorganic fine particles in a water-repellent resin are in a desired state on a discharge port surface to which the discharge port is connected. Consists of things that are distributed in
A liquid-jet printing apparatus, comprising a water-repellent material layer on the surface of which the fine particles are intermittently projected. 23. The water-repellent resin is an alternating copolymer of full olefin and vinyl ether, a photo-radical polymerization type fluororesin composition comprising a reactive oligomer and a diluting monomer, a copolymerization type comb-type fluoropolymer, fluorosilicone, 23. A perfluorocyclopolymer selected from the group of claims 22.
The liquid jet printing apparatus according to item 1. 24. The inorganic fine particles are silica, alumina,
The liquid jet printing apparatus according to claim 22, which is selected from magnesia. 25. The liquid jet printing apparatus according to claim 22, wherein the energy generating element is an electrothermal converter. 26. The liquid jet printing apparatus according to claim 22, wherein the inorganic fine particles are in a substantially uniformly dispersed state. 27. The average particle diameter of the inorganic fine particles is 1.0 μm.
23. The liquid jet printing apparatus according to claim 22, which has a thickness of m or less. 28. The average particle diameter of the inorganic fine particles is 0.5 μm.
28. The liquid jet printing apparatus according to claim 27, which has a thickness of m or less.