JP2001105598A - Ink jet recording method, and recording head and recording apparatus for performing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording apparatus having a scorching removing function or means capable of effectively removing the scorching generated on the contact surface of ink of the heat generating part of a head while enhancing the life of the head, and a recording method using the same. SOLUTION: As the upper protective layer of an ink jet head, a film of an amorphous alloy represented by compositional formula (I): TaαFeβNiγCrδ (wherein 10 atomic %<=α<=30 atomic %, α+β is less than 80 atomic %, β is larger than α, δ is larger than γ and α+β+γ+δ is 100 atomic %) is used and a defoaming agent is added to the ink supplied to the ink jet head or a multi- pulse wherein a pulse for removing scorching is compounded with a drive pulse applied to the heating elements of the ink jet head is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording method for performing recording by discharging ink onto a recording material, and a recording head and apparatus used therefor.

[0002]

2. Description of the Related Art In an ink-jet system using a heating element, heat is applied to the ink, so that the ink and impurities in the ink burn, and an oxide film or the like is formed on a surface of the heating element which comes into contact with the ink. It adheres or deposits as a solid. When such solid matter adheres or accumulates on the heating element, the heat generated in the heating element is not efficiently transmitted to the ink, and the heat efficiency is deteriorated, and the amount of ink droplets flying from the ejection port also changes. There is a problem that a portion where the density is not obtained is generated in the image, and density unevenness may occur in the image. In addition, since heat is not efficiently transmitted to the ink, the heat is accumulated in the heating element and may be overheated to cause disconnection or the like.

[0003] In response to such unevenness in image density due to the adhesion or deposition of solids, the solids adhered or deposited on the surface of the protective layer on the heating element are converted into bubbles generated in the liquid by heat generated from the heating element. It is known that it can be removed to some extent by mechanical shock (cavitation) when it disappears.

For example, Japanese Patent Application Laid-Open No. Hei 6-122198 discloses that a multi-pulse drive different from a single square wave drive pulse used in normal printing is performed to increase the cavitation force and to separate the deposits deposited on the heating element. Let
Removal is described.

In Japanese Patent Application Laid-Open No. Hei 7-81081,
Wiping is performed for each predetermined number of dots, and driving for removing adhering substances deposited on the heating element is performed together with the wiping. In this publication, the volume of kogation is calculated for each heating element, and a pulse for removing kogation is applied to necessary heating elements so that the difference in the volume of kogation between heating elements is reduced. It is described that the printing density after each heating element is kept constant.

Further, Japanese Patent Application Laid-Open No. Hei 8-90790 discloses that multi-step driving is performed under a plurality of different driving conditions to change the position of a bubble erasing point at which bubbles disappear, so that a wide range on a heating element can be obtained. It is described that foreign matter is removed.

On the other hand, the heat acting portion in which the heat from the heating element of the ink jet head acts on the liquid to be discharged such as ink is exposed to a severe environment.
The protective film having a heat acting portion on the surface of the uppermost layer is, for example, an electrically insulating layer made of SiO ₂ , SiC, Si ₃ N ₄ or the like, and a single crystal or polycrystal such as Ta on the uppermost layer. It is a general practice to provide at least a cavitation-resistant film made of, and to protect the heat acting portion from the use environment. As a constituent material of a protective film used in such an ink jet head, for example, US Pat.
No. 89, which is resistant to mechanical impact (cavitation). In some cases, Ta ₂ O ₅ is provided between the anti-cavitation film and the film of the electrical insulating layer as an adhesion layer for improving the interlayer bonding.

[0008]

However, if the method described in the above publication is used to prevent the concentration unevenness due to the deposits on the heating element, the mechanical shock (cavitation) when the bubbles disappear is increased. Therefore, there is a problem that the deterioration and destruction of the protective film itself are accelerated, and the life of the head is extremely shortened in some cases.

Conversely, if the thickness of the upper protective layer (anti-cavitation film) is increased in order to increase the life of the head, the temperature of the upper protective layer is increased with respect to the driving conditions, and ejection unstable elements due to kogation increase. Would. Of course, when the thickness of the upper protective layer is reduced, the use of the kogation removing means may not be sufficient as a product. Therefore, when the conventional kogation removing means is used, the heating element is disconnected, so that the head needs to be replaced, and only the energy required for bubble formation as a head driving condition increases, and a practically effective solution can be obtained. Not.

[0010]

[Means for solving the problems]
As a result of the examination, the kogation is mainly the one where the heat from the heating element of the upper protective layer is physically adsorbed on the surface portion that comes into contact with the recording liquid such as ink. It has also been found that the component to be is a decomposed product of a coloring material or an impurity in the ink. It is also known that this kogation adheres (adsorbs) or peels off in accordance with foaming and defoaming of foam.

Therefore, a method of removing the kogation by increasing the cavitation force according to the driving conditions was also examined. However, the case where the upper protection layer as the anti-cavitation film is broken by the force and the heating element is disconnected is caused. Were observed.

Therefore, the present inventors have considered a method of maintaining the life of the anti-cavitation film while removing kogation. In other words, it is desirable that the anti-cavitation film reduce damage to the film even when a mechanical action called cavitation works, and is not corroded by acidic / alkaline ink. Then, they came to consider that an amorphous alloy having as few grain boundaries as possible and having a passive film formed on the surface is preferable.

That is, an object of the present invention is to provide a head, particularly a head having a defoaming pressure improving means capable of improving the stability of ejection characteristics while maintaining the durable life of an upper protective layer as an anti-cavitation film. An object of the present invention is to provide a mounted inkjet recording method and a recording head and an apparatus used for the method.

According to the ink jet recording method of the present invention, which can achieve the above object, there is provided a discharge port for discharging a liquid, and a thermal action section which communicates with the discharge port and applies thermal energy for discharging the liquid to the liquid. A liquid flow path having: a heating element for generating the thermal energy; and an upper protective layer forming at least a contact surface of the heat acting portion with the liquid. Applying a drive pulse to the heating element, generating thermal energy from the heating element to generate bubbles in the liquid in the liquid flow path, the inkjet recording method of discharging droplets, As the upper protective layer, the composition formula (I): TaαFeβNiγCrδ (I) (provided that 10 atomic% ≦ α ≦ 30 atomic% and α + β <
80 atomic%, α <β and δ> γ, and α +
β + γ + δ = 100 atomic%. ) And using defoaming pressure improving means for increasing the defoaming pressure of the bubbles.

Further, an ink jet head according to the present invention has a liquid flow having a discharge port for discharging a liquid, and a thermal action section communicating with the discharge port and applying a thermal energy for discharging the liquid to the liquid. Path, a heating element for generating the heat energy, and an upper protective layer forming at least a contact surface of the heat acting portion with the liquid, and a driving pulse is supplied to the heating element according to drive information. An ink jet head that discharges liquid droplets by applying heat to generate thermal energy from the heating element to generate bubbles in the liquid in the liquid flow path, wherein the upper protective layer has the following composition formula ( I): TaαFeβNiγCrδ (I) (provided that 10 atomic% ≦ α ≦ 30 atomic% and α + β <
80 atomic%, α <β and δ> γ, and α +
β + γ + δ = 100 atomic%. ), Wherein the liquid comprises an ink containing an antifoaming agent as the liquid.

Further, the ink jet recording apparatus according to the present invention has an ejection port for ejecting a liquid,
A liquid flow path having a heat acting part for applying heat energy to the liquid to discharge the liquid, a heating element for generating the heat energy, and at least a contact surface of the heat acting part with the liquid. And an upper protective layer to be formed,
Applying a drive pulse to the heating element according to the drive information,
An ink jet recording apparatus having an ink jet head that generates thermal energy from the heating element to generate air bubbles in a liquid in the liquid flow path to discharge droplets, wherein the upper protective layer has the following composition: Formula (I): TaαFeβNiγCrδ (I) (provided that 10 atomic% ≦ α ≦ 30 atomic% and α + β <
80 atomic%, α <β and δ> γ, and α +
β + γ + δ = 100 atomic%. And a drive pulse control means for applying a pulse for improving the defoaming pressure to the drive pulse applied to the heating element.

According to the present invention, a solid substance attached or deposited on the contact surface of the heat acting portion in the liquid flow path with the liquid (ink), particularly a solid substance produced by the action of heat on the ink. Kimono or deposits (collectively, kogation) can be surely removed, and the occurrence of image density unevenness or the like due to the generation of kogation can be effectively prevented while sufficiently satisfying the life of the head.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, an ink jet recording method, a recording head and a recording apparatus according to the present invention employ a method of forming a contact surface with a liquid (recording liquid or ink) in a liquid flow path in a heat acting section. It is formed from an amorphous alloy having the composition of the above composition formula (I), and has means for improving the defoaming pressure.

As one mode of the defoaming pressure improving means, an antifoaming agent for improving the defoaming pressure after foaming of the recording liquid accompanying the heat generation of the heating element is supplied to the liquid (recording liquid) supplied to the liquid flow path. Is preferable. As this antifoaming agent, a B factor solvent can be suitably used for the recording liquid. As the factor B solvent, at least one of glycerin and ethyl glycol can be suitably used.

The contact surface of the heat acting portion with the recording liquid in the liquid flow path is formed from an amorphous alloy having the composition of the above composition formula (I).

Further, as another mode of the defoaming pressure improving means, it is preferable that the pulse for driving the heating element is a multi-pulse.

Hereinafter, the present invention will be described in detail with reference to the drawings, but the present invention is not limited to the following embodiments.

First, the configuration of each part of the ink jet recording apparatus to which the present invention can be applied will be described with reference to FIG. FIG. 1 is an external perspective view showing an example of an ink jet recording apparatus in which a head to which the present invention can be applied is mounted as an ink jet head cartridge (IJC). In the figure, 10
Reference numeral 1 denotes an ink jet head cartridge (IJC) including a nozzle group for discharging ink while facing a recording surface of a recording sheet sent on a platen 107. 102
Is a carriage HC that holds the IJC 101, is connected to a part of the drive belt 104 that transmits the driving force of the drive motor 103, and is slidable with two guide shafts 105 and 106 arranged in parallel with each other. By doing
The reciprocating movement over the entire width of the recording paper of the IJC 101 becomes possible. A head recovery device 110 is provided at one end of the movement path of the IJC 101, for example, at a position facing the home position. Motor 108 via transmission mechanism 109
The head recovery device 110 is operated by the driving force of, and the IJC 101 is capped. The IJC 101 by the cap unit 111 of the head recovery device 110
In connection with capping the head recovery device 110
Ink suction by an appropriate suction means provided in
Discharge recovery processing such as removing ink with increased viscosity in the nozzles by performing ink pressure feeding by an appropriate pressurizing means provided in the ink supply path to the JC 101 and forcibly discharging ink from the discharge ports. Also, by performing capping at the end of recording or the like, IJC is protected. 113
Is a blade as a wiping member provided on the side surface of the head recovery device 110 and made of silicone rubber. The blade 113 is held in a cantilever form by a blade holding member 112, and like the head recovery device 110,
Operated by the motor 108 and the transmission mechanism 109,
Engagement with the ejection surface of JC101 becomes possible. Thus, at an appropriate timing in the recording operation of the IJC 101, or after the ejection recovery processing using the head recovery device 110, the blade 113 is made to protrude into the movement path of the IJC 101, and the IJC 101 is moved with the movement operation of the IJC 101.
No. 01 wipes dew condensation, wetness, dust and the like on the discharge surface.

Next, the ink jet head will be described. FIG. 2 is a fragmentary perspective view showing the configuration of an embodiment of an ink-jet head to which the present invention can be applied, and FIG. 3 is a main portion showing the structure of a portion of the ink-jet head provided with a heat application section 202. It is sectional drawing.

The electrode layer 207 is laminated below the heat acting portion 202 so as to have opposite ends at a predetermined interval on the heat generating resistor layer 201, so that heat is generated between a pair of opposed electrodes. A heating element on which a resistor is arranged is formed, in which electric energy is converted to heat energy. The heat generated by the heating element is applied to the recording liquid from the surface of the heat acting section 202 located above the heating element. This inkjet head is manufactured using a semiconductor manufacturing process technology such as etching, vapor deposition, and sputtering. For example, the heat storage layer 3 is formed on a silicon substrate 206.
03, a plurality of thin-film heating elements are collectively formed thereon, and an insulating protective layer 302 and an anti-cavitation film 301 are formed so as to cover all the heating elements.

Further, the ink jet head has a liquid passage wall 208 for separating adjacent liquid passages (liquid passages) 204, a top plate 203, a common liquid chamber 210 communicating with each liquid passage 204, and recording in a common liquid chamber 210. A liquid supply pipe 209 for supplying the liquid 212 for use, and a connector 211 for connecting the liquid supply pipe 209 and the common liquid chamber 210. The heat acting section 202 is provided for each liquid path 204. The recording liquid 212 is supplied from a liquid storage chamber (not shown) to the common liquid chamber 210 through a liquid supply pipe 209. Recording liquid 212 supplied into common liquid chamber 210
Is supplied into the liquid passage 204 by capillary action, and the liquid
By forming a meniscus at the discharge port 205 at the tip of No. 4, the liquid is stably held. Here, when a current is applied to the heating element 201 through the electrode 207, the heat acting portion 202 generates heat, and the recording liquid 212 is heated through the insulating protective layer 302 and the anti-cavitation film 301 and foamed by film boiling. Droplets are discharged from the discharge port 205 by the energy of foaming. The number of the ejection ports 205 can be 128, 256, or more at a high density of 16 / mm. Further, the number of the ejection ports 205 can be as large as the entire width of the recording area of the recording medium. It can also be.

The insulating protective layer 302 is formed of the heating resistor layer 210
In addition, the electrode layer 207 prevents electrical erosion and electrical breakdown due to contact with a recording liquid (ink), and is made of a material having excellent insulation and heat resistance. For example, inorganic oxides such as SiO ₂ , titanium oxide, vanadium oxide, niobium oxide, molybdenum oxide,
Transition metal oxides such as tantalum oxide, tungsten oxide, chromium oxide, zirconium oxide, hafnium oxide, lanthanum oxide, yttrium oxide, manganese oxide, etc.
Examples include metal oxides such as aluminum oxide, calcium oxide, strontium oxide, barium oxide, and silicon oxide, and composites thereof; nitrides such as silicon nitride, aluminum nitride, and boron nitride; and oxides thereof. Among them, from the viewpoints of easy handling and processing of materials, stability or availability, etc., SiO ₂ , Si
₃ N ₄ , Ta ₂ O _{5 and the} like are preferably used.

The thickness of the protective layer 302 is, for example, 0.1 mm.
It can be in the range of 1 to 2.0 μm, preferably 0.2 to 1.0 μm.

Next, a cavitation-resistant film, which is the uppermost protective film on the heating element, will be described. A typical material that has been conventionally used is Ta. On the other hand, the amorphous alloy used in the present invention has no crystal interface serving as a starting point of a corrosion reaction in the amorphous region and has a surface. It is easy to form a passivation film having corrosion resistance, that is, a film containing an oxide of a component constituting an alloy, and is a material which is much more excellent in corrosion resistance than Ta.

The amorphous alloy as a material for forming the upper protective layer has a composition represented by the above-mentioned composition formula (I). In the composition formula (1), α is preferably 10 atomic% (at.%) ≦ α ≦ 20 at.%. Further, it is preferable that γ ≧ 7 at.% And δ ≧ 15 at.%, And further, γ ≧ 8 at.% And δ ≧ 1
More preferably, it is 7 at.%.

On the other hand, the thickness of the upper protective layer is, for example, 10
To 500 nm, the lower limit of which is preferably 50 nm, more preferably 100 nm,
More preferably, it can be set to 200 nm. Also,
The upper limit is preferably 300 nm, more preferably 2 nm.
00 nm.

In this amorphous alloy film, the amount of Ta is set in the range of 10 at.% To 20 at.%, Which is lower than that of the conventional Ta-based alloy. By adopting such a low Ta ratio, an appropriate amorphous region is imparted to the alloy to form a passivation film, and the location of the crystal interface serving as a starting point of the corrosion reaction is significantly reduced, and the cavitation resistance is improved. The ink resistance can be improved while maintaining the level. Furthermore, since the oxide of the constituent component is present on the surface of the amorphous alloy film, and preferably the surface is coated with the oxide film, the ink resistance is further improved. That is, it is preferable that at least the surface of the upper protective layer made of the amorphous alloy film that is in contact with the ink is coated with an oxide film as a component of the upper protective layer. Is 5n
It is preferably at least m and at most 30 nm.

As described above, by forming an oxide film mainly composed of Cr on the surface of the upper protective layer, various inks,
In particular, even in an ink containing a divalent metal salt such as Ca or Mg or a component forming a chelate complex, the effect as a passive film is exhibited, and erosion by the ink from each part can be prevented.

As a method for forming the above-mentioned oxide film mainly composed of Cr, there is a method in which after the upper protective layer is formed, a heat treatment is performed in the air or in an oxygen atmosphere. For example, the heat treatment is performed in an oven at 50 ° C. to 200 ° C. Alternatively, an oxide film may be formed by forming an upper protective layer with a sputtering apparatus and then introducing oxygen gas into the apparatus and heating the apparatus.
Alternatively, the oxide film may be formed by driving the application of a pulse after forming the inkjet head.

The film stress of the upper protective layer is small.
Both have compressive stress, 1.0 × 10 ^Tendyne / cm^Two
The following is preferred.

The amorphous alloy film can be formed by various methods. For example, it can be formed by a film forming method using a sputtering apparatus shown in FIG. FIG.
Numeral 4001 denotes a target composed of Ta-Fe-Cr-Ni prepared in advance to have a predetermined composition, that is, a composition necessary to obtain an amorphous alloy layer satisfying the above composition formula (1), 4002 denotes a plate magnet, 4011 Is a shutter for controlling film formation on a substrate, 4003 is a substrate holder, 4004 is a substrate,
Reference numeral 4006 denotes a power supply connected to the target 4001 and the substrate holder 4003. Further, in FIG. 8, reference numeral 4008 denotes a film forming chamber 4009.
Is an external heater provided around the outer peripheral wall of the external heater. The external heater 4008 is used for adjusting the ambient temperature of the film forming chamber 4009. On the back surface of the substrate holder 4003, an internal heater 4005 for controlling the temperature of the substrate is provided. substrate
The temperature control of 4004 is preferably performed by using an external heater 4008 together.

A specific film formation using the apparatus shown in FIG. 8 is performed, for example, as follows. First, the film formation chamber 4009 is evacuated to 1 × 10 ⁻⁵ to 1 × 10 ⁻⁶ Pa using the exhaust pump 4007.
Next, an argon gas is introduced into the film formation chamber 4009 from the gas inlet 4010 via a mass flow controller (not shown). At this time, the internal heater 4005 and the external heater 4008 are adjusted so that the substrate temperature and the ambient temperature become predetermined temperatures. Next, power is applied to the target 4001 from the power source 4006 to perform sputtering discharge, and the shutter 4011
Is adjusted to form a thin film on the substrate 4004.

The upper protective layer is formed by the above-described Ta-Fe-
Not only is the sputtering method using an alloy target made of Cr-Ni, but also a separate Ta target and an Fe-Cr-Ni target, and power is applied from two power sources connected to each other. It is also possible to form by the original simultaneous sputtering method. In this case, it is possible to independently control the power applied to each target.

As described above, in forming the upper protective layer, a strong film adhesion can be obtained by heating the substrate to a temperature of 100 to 300 ° C. Further, by forming a film by a sputtering method capable of forming particles having relatively large kinetic energy as described above, a strong film adhesion can be obtained.

Further, the film stress has at least a compressive stress, and by setting the film stress to 1.0 × 10 ¹⁰ dyne / cm ² or less, a strong film adhesion can be similarly obtained. The film stress may be adjusted by appropriately setting the flow rate of the Ar gas introduced into the film forming apparatus, the power applied to the target, and the substrate heating temperature.

Next, with reference to FIGS. 3 and 4, a method of manufacturing an ink jet head using an amorphous alloy for a cavitation-resistant film as a top protective film on a heating element according to the present invention will be described below. First, the Si substrate 206 was treated by steam thermal oxidation at 1150 ° C. for 6 hours to form a thermal storage film 303 of about 2 μm of SiO ₂ . Next, the heating element 201, here N
_A TaN film was formed to a thickness of about 100 nm by a reactive sputtering method using _two gases. Next, an Al film having a thickness of about 600 nm was formed by a sputtering method. Next, by photolithography, the Al film is patterned into a predetermined shape, the TaN film is patterned into a predetermined shape, and a predetermined portion of the Al film is removed from the TaN film.
A heating element having a heating resistor composed of the electrode layer 207, the heating resistor layer 201, and the portion of the heating resistor layer 201 exposed between the ends of the opposing electrode layer 207 was obtained. Next, CV
Insulating protective layer 302 of about 1 μm SiO ₂ film by D method
Was formed. Next, an amorphous alloy having the composition of the composition formula (I) shown above was formed as a cavitation-resistant film 301 on the insulating protective layer 302 to a thickness of 230 nm by a sputtering method, and was formed into a predetermined shape by a photolithographic method. Finally, the electrode 207 was exposed from a predetermined portion of the protective film by a photolithography method to form an electrode terminal portion.

An ink jet head applicable to the present invention can be similarly manufactured using not only a Si substrate but also a substrate incorporating an integrated circuit as shown in FIG. The structure shown in FIG. 4 was formed, for example, by the following procedure.
A dopant such as As was introduced into a P conductive Si substrate 401 by means of ion plantation and diffusion to form an N-side buried layer 402, and an N-type epitaxial layer 403 was formed thereon with a thickness of 8 μm. Further, a P-type well region 404 was formed by introducing impurities such as B into the epitaxial layer 403. Thereafter, photolithography and impurity introduction such as oxidation diffusion and ion plantation are repeated to form a P-M
The N-MOS 451 was formed in the OS 450 and the P-type well region. The P-MOS 450 and the N-MOS 451 are connected to each other through a gate insulating film 415 having a thickness of 50 nm.
A gate wiring 415 of poly-Si deposited by a CVD method to a thickness of nm and introduction of N-type or P-type impurities were constituted by a source region 405, a drain region 406, and the like. The NPN transistor 452 serving as a power transistor also has a collector region 411,
It comprises a base region 412, an emitter region 413 and the like. An oxide film isolation region 453 is formed between the elements by field oxidation with a thickness of 1000 nm to isolate the elements. This field oxide film is formed by the heat acting portion 45.
Below 5, it acts as the first heat storage layer 414. After each element is formed, the interlayer insulating film 416 has a thickness of about 700 n.
An m-thick layer was deposited by PSG, BPSG, or the like by a CVD method, flattened by heat treatment, and then wiring was performed by a first-layer Al electrode 417 through a contact hole. Thereafter, an SiO ₂ interlayer insulating film 418 is formed to a thickness of about 1.4 μm by a plasma CVD method, and a heating resistance layer 419 is formed to a thickness of about 100 through a through hole.
A second Al layer 420 was formed by sputtering using TaN to a thickness of nm. Protective film 42
In No. 1, SiO ₂ was formed to a thickness of about 1 μm by a plasma CVD method. Next, an amorphous alloy having the composition of the composition formula (I) shown above was formed as a cavitation-resistant film on the insulating protective layer to a thickness of 230 nm by a sputtering method, and was formed into a predetermined shape by a photolithographic method.
Finally, the exposed portion of the electrode of the protective film was formed by a photolithography method. The substrate formed by the above procedure is the logic circuit unit 46
3, the driving Tr section 462 and the heating resistor section 461;

Next, the control configuration will be described. A control configuration for executing the recording control of each unit of the above-described apparatus configuration will be described with reference to a block diagram shown in FIG. In the figure showing a control circuit, 501 is an interface for inputting a recording signal, 502 is an MPU, 503 is an MPU 5
02 for storing a control program to be executed by the second program
An OM 504 is a dynamic RAM for storing various data (such as the print signal and print data supplied to the head). A gate array 505 controls supply of print data to the print head 509, and also controls data transfer between the interface 501, the MPU 502, and the RAM 504. Reference numeral 511 denotes a carrier motor for transporting the recording head 509, and reference numeral 510 denotes a transport motor for transporting the recording paper. Reference numeral 506 denotes a head driver for driving the head, and 507 and 508 denote transport motors 5
10. A motor driver for driving the carrier motor 20.

FIG. 6 is a circuit diagram showing details of each part.
The gate array 505 includes a data latch 601, a segment (SEG) shift register 602, a multiplexer (MPX) 603, a common (COM) timing generation circuit 604, and a decoder 605. Recording head 509
Has a diode matrix configuration, and a drive current flows through the ejection heaters (H1 to H64) where the common signal COM and the segment signal SEG coincide, whereby the ink is heated and ejected.

The decoder 605 decodes the timing generated by the common timing generation circuit 604 and selects one of the common signals COM1 to COM8. The data latch 601 latches the recording data read from the RAM 504 in units of 8 bits, and the multiplexer 603 outputs the recording data as segment signals SEG1 to SEG8 according to the segment shift register 602. The output from the multiplexer 603 can be variously changed according to the contents of the shift register 602, such as 1-bit unit, 2-bit unit, or all 8 bits, as described later.

Next, the operation of the above control configuration will be described. In FIG. 5, when a print signal is input to the interface 501, the print signal is converted between the gate array 505 and the MPU 502 into print data for printing. Then, the motor drivers 507 and 508 are driven, and the recording head is driven according to the recording data sent to the head driver 506 to perform printing.

The energy P applied to the heating element of the recording head per unit time satisfies the following equation: P = V ² / (R + r) × Pw × N (1) Here, in the above equation, V: drive voltage [V] R: resistance value of the heating element [Ω] r: resistance of the wiring electrically connected to the heating element [Ω] Pw: drive pulse width [μsec] N : The number of heating elements provided.

In order to stably maintain the generation of bubbles on the heating element, a driving voltage satisfying the following equation is applied: K = Vop / Vth (2) here,
In the above equation, Vop: practical drive voltage [V] Vth: film boiling start voltage [V] K: constant

Next, the coloring material contained in the recording liquid (ink) that can be used in the present invention will be described. It is preferable to use a dye or a pigment as the coloring material. As the dye, any dye such as a direct dye, an acid dye, a basic dye, and a disperse dye can be used.

Specifically, for example, C.I. I. Direct Black-4, -9, -11, -17, -19, -2
2, -32, -80, -151, -154, -168,
-171, -194, -195; I. Direct Blue-1, -2, -6, -8, -22, -34, -7
0, -71, -76, -78, -86, -142, -1
99, -200, -201, -202, -203, -2
07, -218, -236, -287; C.I. I. Direct Red-1, -2, -4, -8, -9, -11,-
13, -15, -20, -28, -31, -33, -3
7, -39, -51, -59, -62, -63, -7
3, -75, -80, -81, -83, -87, -9
0, -94, -95, -99, -101, -110,-
189, -225, -227; I. Direct Yellow-1, -2, -4, -8, -11, -12, -2
6, -27, -28, -33, -34, -41, -4
4, -48, -86, -87, -88, -132, -1
35, -142, -144; I. Food Black-
1, -2; C.I. I. Acid Black-1, -2,-
7, -16, -24, -26, -28, -31, -4
8, -52, -63, -107, -112, -118,
-119, -121, -172, -194, -208;
C. I. Acid Blue-1, -7, -9, -15,-
22, -23, -27, -29, -40, -43, -5
5, -59, -62, -78, -80, -81, -9
0, -102, -104, -111, -185, -25
4; I. Acid Red-1, -4, -8, -1
3, -14, -15, -18, -21, -26, -3
5, -37, -52, -249, -257, -289;
C. I. Acid Yellow-1, -3, -4, -7,-
11, -12, -13, -14, -19, -23, -2
5, -34, -38, -41, -42, -44, -5
3, -55, -61, -71, -76, -79;
I. Reactive Blue-1, -2, -3, -4,-
5, -7, -8, -9, -13, -14, -15, -1
7, -18, -19, -20, -21, -25, -2
6, -27, -28, -29, -31, -32, -3
3, -34, -37, -38, -39, -40, -4
1, -43, -44, -46; C.I. I. Reactive Red-1, -2, -3, -4, -5, -6, -7,-
8, -11, -12, -13, -15, -16, -1
7, 19, -20, -21, -22, -23, -24,
-28, -29, -31, -32, -33, -34,-
35, -36, -37, -38, -39, -40, -4
1, -42, -43, -45, -46, -49, -5
C. 0, -58, -59, -63, -64, -180;
I. Reactive Yellow-1, -2, -3, -4,-
6, -7, -11, -12, -13, -14, -15,
-16, -17, -18, -22, -23, -24,-
C. 25, -26, -27, -37, -42; I. Reactive Black-1, -3, -4, -5, -6,-
8, -9, -10, -12, -13, -14, -18;
Projet Fast Cyan 2 (Zeneca), Projet Fast Magenta 2 (Zeneca), Projet Fast Yellow 2 (Zeneca), Projet Fast Black 2 (Zeneca); and the like, but are not limited thereto. Not something.

As the pigment, any pigment such as an inorganic pigment and an organic pigment can be used. Specifically, carbon black; I. Pigment Yellow 1, -2, -3,
-12, -13, -14, -16, -17, -73,-
74, -75, -83, -93, -95, -97, -9
8, -114, -128, -129, -151, -15
4, -195; I. Pigment Red-5, -7,
-12, -48 (Ca), -48 (Mn), -57 (C
a), 57: 1, 57 (Sr), 112, 122, 12
3, 168, 184, 202; I. Pigment Blue-1, -2, -3, -15: 3, -15: 34, -1
6, -22, -60; C.I. I. Vat Blue-4,-
6; and the like.

When these pigments are used, it is preferable to use a dispersant in order to stably disperse the pigment in the ink. Examples of the dispersant include a polymer dispersant and a surfactant dispersant. Specific examples of the polymer dispersant include polyacrylate, styrene-acrylic acid copolymer salt, styrene-methacrylic acid copolymer salt, styrene-acrylic acid-acrylate copolymer salt, styrene-maleic acid Copolymer salt, acrylate-maleic acid copolymer salt, styrene-methacrylsulfonic acid copolymer salt, vinylnaphthalene-maleic acid copolymer salt, β-
Naphthalene sulfonic acid formalin condensate, polyvinylpyrrolidone, polyethylene glycol, polyvinyl alcohol and the like. The weight average molecular weight of the polymer dispersant is in the range of 1,000 to 30,000, and the acid value is 100.
The range of -430 is preferable. Examples of the surfactant dispersant include laurylbenzenesulfonate, laurylsulfonate, laurylbenzenecarboxylate, laurylnaphthalenesulfonate, aliphatic amine salt, polyethylene oxide condensate and the like. The use amount of these dispersants is preferably in the range of pigment weight: dispersant weight = 10: 5 to 10: 0.5.

Further, a carbon black capable of self-dispersion by introducing a water-soluble group into the surface of carbon black as described in JP-A-5-186704 and JP-A-8-3498 is used. Can be used. When using self-dispersible carbon black, it is not necessary to use a dispersant.

These dyes and pigments may be used alone or
Alternatively, two or more kinds may be used in combination. The concentration of these dyes and pigments is usually 0.1 to the total amount of the ink.
It is appropriately selected from the range of 1 to 20% by weight.

Next, a liquid medium as a component of the ink that can be used in the present invention will be described. It is preferable to use water and a water-soluble organic solvent in combination as a liquid medium. As the water that can be used in the present invention, it is preferable to use deionized water instead of general water containing various ions.
The water content is preferably in the range of 35 to 96% by weight based on the total amount of the ink.

The water-soluble organic solvent is used to adjust the viscosity of the ink to an appropriate viscosity and surface tension which are preferable for use, and to slow down the drying speed of the ink, increase the solubility of the coloring material, and reduce the clogging of the nozzles of the recording head. Used to prevent. Specific examples of the water-soluble organic solvent include, for example, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-
C1-C5 such as butyl alcohol, tert-butyl alcohol, isobutyl alcohol, and n-pentanol
Amides such as dimethylformamide and dimethylacetamide; ketones or keto alcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol; Oxyethylene or oxypropylene copolymers such as tripropylene glycol, polyethylene glycol and polypropylene glycol; alkylene groups such as ethylene glycol, propylene glycol, trimethylene glycol, triethylene glycol, 1,2,6-hexanetriol and hexylene glycol Glycols containing 2 to 6 carbon atoms; glycerin, trimethylolethane, trimethylol Lopan; lower alkyl ethers such as ethylene glycol monomethyl (or ethyl) ether, diethylene glycol monomethyl (or ethyl) ether, and triethylene glycol monomethyl (or ethyl) ether; triethylene glycol dimethyl (or ethyl) ether, tetraethylene glycol dimethyl ( Or lower) dialkyl ethers of polyhydric alcohols such as ethyl) ether; alkanolamines such as monoethanolamine, diethanolamine and triethanolamine; sulfolane, N-methyl-2-pyrrolidone, 2-pyrrolidone and 1,3-dimethyl- 2-imidazolidinone and the like. These water-soluble organic solvents can be used alone or in combination of two or more thereof as necessary.

In order to stabilize the solubility of the dye and the dispersibility of the pigment in the ink by keeping the pH value of the ink of the present invention constant, a pH adjuster may be contained in the ink. Specifically as the pH adjuster, for example, hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide and ammonium hydroxide, sulfuric acid, acetic acid, acids such as hydrochloric acid,
Sulfates such as lithium sulfate, sodium sulfate, potassium sulfate and ammonium sulfate; lithium carbonate, sodium carbonate, sodium hydrogen carbonate, potassium carbonate, potassium hydrogen carbonate, sodium carbonate, potassium carbonate, ammonium carbonate and ammonium hydrogen carbonate, and the like; lithium phosphate Phosphates such as monosodium phosphate, disodium phosphate, trisodium phosphate, monopotassium phosphate, dipotassium phosphate, tripotassium phosphate, monoammonium phosphate, diammonium phosphate, triammonium phosphate And acetates such as lithium acetate, sodium acetate, potassium acetate and ammonium acetate.

These salts may be used alone by adding them to the ink, but it is more preferable to use two or more of these salts in combination. The total amount of these salts is preferably 0.1 to 10% by weight, more preferably 1 to 10% by weight.
８8% by weight. If the amount is less than 0.1% by weight, it is difficult to keep the pH of the ink constant, and the effect of dissolution stability of the aqueous dye contained in the ink may be small. On the other hand, if the content is more than 10% by weight, crystals of these salts may precipitate and cause clogging of the nozzle, which is not preferable.

Further, in addition to the above components, the ink of the present invention may contain, if necessary, various conventional additives known in the art, such as a viscosity modifier, a fungicide, a preservative, an antioxidant, A nozzle drying inhibitor such as an antifoaming agent, a surfactant, and urea can be appropriately used in combination.

The preferable range of the physical properties of the ink of the present invention is that the pH at 25 ° C. is preferably 3 to 12, more preferably 4 to 10, and the surface tension is preferably 10 to 60 d.
yn / cm, more preferably 15 to 50 dyn / cm,
The viscosity is preferably 1 to 30 cps, more preferably 1 to 30 cps.
The range is 10 cps.

It is necessary to remove the kogation in order to prevent the concentration unevenness caused by the kogation adhered or deposited on the anti-cavitation film as the uppermost protective film on the heating element. The function of removing kogation in the present invention can be obtained by incorporating an antifoaming pressure controlling agent for controlling the antifoaming pressure after foaming of the recording liquid accompanying the heat generation of the heating element into the ink. As the defoaming pressure control agent, a factor B solvent can be suitably used.

The B-factor solvent is disclosed in JP-A-59-9515.
As described in Japanese Patent Publication No. 4 (1999) -1994, it has the property of characterizing the bubble collapse dynamics, and has the effect of increasing the foaming pressure and the defoaming pressure. Specific examples of the factor B solvent include glycerin and ethylene glycol. The content is preferably in the range of 15 to 30% by weight based on the total amount of the ink. When the amount is less than 1% by weight, the defoaming pressure effect of the factor B solvent is insufficient, so that a pressure sufficient to remove kogation cannot be generated. When the amount is more than 30% by weight, the foaming pressure effect of the factor B solvent is too strong, so that illegal foaming occurs. cause.

Further, as a means for removing kogation, a pulse to be periodically driven to the heating element is made into a multi-pulse.
A configuration having a drive control mechanism for increasing the mechanical shock (cavitation) when the bubble disappears and changing the frequency of driving the heating element to vary the position of the mechanical shock (cavitation) when the bubble disappears. be able to. The case where the kogation removing means is used will be described below.

FIG. 7 shows an example of drive pulses used in an embodiment of the ink jet recording apparatus of the present invention. The pulse shown in FIG. 7A is a driving pulse used for printing, and the pulse shown in FIG. 7B is a multi-pulse used for removing kogation. In order to effectively increase cavitation and remove kogation, a pulse obtained by adding the pre-pulse and the main pulse shown in FIG. 7B rather than the pulse width of only the main pulse shown in FIG. Increase width. That is, it is necessary to increase Pw and increase the K value from the above equation (1). The driving frequency of the heating element for removing kogation is 500 Hz to 20 KH.
z, and the number of applied pulses during the kogation removal operation is adjusted to match all the frequencies used (main pulse +
(Pre-pulse) 500 to 1000, and the kogation removal operation is 1
It is preferable to execute it every × 10 ⁶ pulses.

[0065]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples and the like, but the present invention is not limited to the inks used in the present invention described below unless it exceeds the gist.
In the following description, “parts” and “%” are based on weight unless otherwise specified.

(Examples 1 to 6) The following components were mixed, sufficiently stirred and dissolved, and the pore size was 0.2 μm.
The inks of Examples 1 to 6 were respectively filtered by pressure filtration with a micro filter (manufactured by Fuji Photo Film Co., Ltd.). Ink composition of Example 1: C.I. I. Food Black 2 2 parts Glycerin 15 parts Water 83 parts Ink composition of Example 2 I. Food Black 2 2 parts Ethylene glycol 15 parts Water 83 parts Ink composition of Example 3 Projet Fast Black 2 (Zeneca) 2 parts Glycerin 20 parts Water 78 parts Ink composition Projet Fast Black 2 of Example 4 (Zeneca) 2 parts Ethylene glycol 20 parts Water 78 Part (Preparation of Pigment Dispersion Liquid 1) Styrene-acrylic acid-butyl acrylate copolymer ... 5 parts (acid value 116, average molecular weight 3700) triethanolamine ... 0.5 part Diethylene glycol 5 parts Water 69.5 parts The above ingredients were mixed and heated to 70 ° C in a water bath.
Completely dissolve the resin component. Carbon black “MA-100” (pH 3.5; Mitsubishi Chemical Corporation) was added to this solution.
15 parts of 2-propanol, and premixing for 30 minutes, followed by dispersion treatment under the following conditions.

Disperser Sand glider (made by Igarashi Kikai) Pulverization media Zirconium beads 1 mm diameter Filling rate of pulverization media 50% (volume) Pulverization time 3 hours Further, centrifugal dispersion treatment (12000 rpm, 20 minutes) is performed to remove coarse particles. Thus, a pigment dispersion liquid 1 was obtained. The following components of the ink composition of Example 5 were mixed in a beaker and stirred at 25 ° C. for 3 hours. This mixture was filtered under pressure with a membrane filter having a pore size of 3.0 μm (manufactured by Fuji Photo Film Co., Ltd.) to obtain an ink composition of Example 5 used in the present invention.・ Pigment Dispersion 1 30 parts ・ Glycerin 20 parts ・ Water 50 parts Ink composition of Example 6・ Pigment Dispersion 1 30 parts ・ Ethylene glycol ・ ・ ・ 20 parts ・ Water ・ ・ ・ ・ ・ ・ 50 parts Ink compositions of Comparative Examples 1 to 3 The following components were mixed, sufficiently stirred and dissolved, and then pore size was obtained. The inks of Comparative Examples 1 to 3 were each prepared by filtration under pressure through a 0.2 μm microfilter (manufactured by Fuji Photo Film Co., Ltd.). Ink composition of Comparative Example 1 I. Food Black 2 2 parts 2-Propanol 15 parts Water 83 parts Ink composition of Comparative Example 2 Projet Fast Black 2 (Zeneca) 2 parts 2-Propanol 20 parts Water 78 parts Ink composition of Comparative Example 3 The components shown below were mixed, sufficiently stirred and dissolved, and then a micro filter (pore size 3 μm) was used. Each of the inks of Comparative Examples 6 to 8 was filtered by pressure filtration using Fuji Photo Film Co., Ltd.).

Pigment dispersion liquid 1 30 parts 2-propanol 20 parts Water 50 parts [Evaluation] The film of the amorphized alloy has a Taα of 200 nm.
Using a FeβNiγCrδ film, the driving pulse is 2 μs
c. At a driving frequency of 10 kHz. The driving voltage was 1.3 × (foaming threshold voltage).

Next, using the inks of Examples 1 to 6 and Comparative Inks 1 to 3, the case where an amorphized alloy was used for the cavitation-resistant film as the uppermost protective film on the heating element. For the recording head using the conventional Ta, the means for removing the kogation for every 1 × 10 ⁶ pulses is used, and the head life when the K value of the above-mentioned equation (2) is 1.3 is used. Table 1 shows the results of investigations on the number of applied pulses up to and the table 2 shows changes in the maximum ejection amount until the head life.

Each evaluation was performed according to the following criteria. Number of applied pulses until head life: 1 × 10 ⁹ or more: A 5 × 10 ⁸ or more, less than 1 × 10 ⁹ : B 1 × 10 ⁸ or more, less than 5 × 10 ⁸ : C Less than 1 × 10 ⁸ : D

[0071]

[Table 1] Maximum discharge amount change just before head life (upper protective layer: amorphous alloy): less than 2%: AA 2% or more and less than 5%: A 5% or more, 10% Less than: B 10% or more: C

[0072]

[Table 2] As described above, an amorphous alloy is used for the cavitation-resistant film as the uppermost protective film on the heating element of the recording head, and a B-factor solvent for controlling the defoaming pressure as a kogation removing means for preventing concentration unevenness. If glycerin or ethylene glycol is used in the composition of the recording liquid and the above-mentioned means for removing kogation is used periodically, the number of applied pulses until the head life becomes longer than 1 × 10 ⁹ , and the density unevenness over the head life becomes longer. It can be seen that the change in the discharge amount due to the adhesion and deposition of kogation that causes turbidity can be about 1%.

[0073]

As described above, the present invention uses the amorphized alloy having the composition represented by the above composition formula (I): TaαFeβNiγCrδ as the upper protective layer constituting the contact surface with the ink on the heating element. In addition, by adopting a configuration further provided with a defoaming pressure improving means, it is possible to solve problems such as uneven image density due to the occurrence of kogation while improving the service life of the head, and to provide a stable image for a long period of time. This has the effect.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of an ink jet recording apparatus to which the present invention can be applied.

FIG. 2 is a fragmentary perspective view showing a configuration of a recording head applicable to the present invention.

FIG. 3 is a cross-sectional view of a main part showing a configuration of a heat acting portion of a recording head applicable to the present invention.

FIG. 4 is a sectional view of a main part showing a configuration of a printhead substrate applicable to the present invention.

FIG. 5 is a control configuration diagram for performing recording control of each section of the apparatus.

FIG. 6 is a circuit diagram showing details of each unit in FIG. 5;

FIG. 7 is an explanatory diagram of an example of a driving pulse used in an embodiment of the ink jet recording apparatus applicable to the present invention.

FIG. 8 is a view showing an example of an apparatus for producing an amorphous alloy film by a sputtering method.

[Explanation of symbols]

 Reference Signs List 101 inkjet head cartridge 102 carriage 103 drive motor 104 drive belt 105, 106 guide shaft 107 platen 108 motor 109 transmission mechanism 110 head recovery device 112 blade holding member 113 blade

Continuing on the front page (72) Inventor: Shiro Shiro 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Takashi Katsuragi 3-30-2, Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Masahiko Kubota 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2C057 AF25 AF66 AF70 AF71 AF93 AG41 AG46 AH20 AP02 AP14 AP52 AP56 AR08 BA05 BA13

Claims (29)

[Claims] 1. A liquid flow path having a discharge port for discharging a liquid, a heat acting portion communicating with the discharge port and applying heat energy for discharging the liquid to the liquid, and generating the heat energy. Applying a drive pulse to the heating element according to drive information using an inkjet head including a heating element for causing the heating element and an upper protective layer forming at least a contact surface of the heat acting section with the liquid;
An ink jet recording method in which thermal energy is generated from the heating element to generate air bubbles in a liquid in the liquid flow path to discharge droplets, wherein the upper protective layer has a composition formula (I): TaαFeβNiγCrδ (I) (provided that 10 atomic% ≦ α ≦ 30 atomic% and α + β <
80 atomic%, α <β and δ> γ, and α +
β + γ + δ = 100 atomic%. An ink jet recording method characterized by using an amorphized alloy comprising: (a) and using defoaming pressure improving means for increasing the defoaming pressure of the bubbles. 2. The ink jet recording method according to claim 1, wherein the defoaming pressure improving means has an antifoaming agent added to the liquid. 3. The ink jet recording method according to claim 2, wherein the antifoaming agent contains a B-factor solvent. 4. The ink jet recording method according to claim 3, wherein the factor B solvent is at least one of glycerin and ethylene glycol. 5. The ink jet recording method according to claim 1, wherein the defoaming pressure improving means has a pulse for removing solids added to a driving pulse applied to the heating element. 6. The ink jet recording method according to claim 1, wherein said bubbles are generated by film boiling in said liquid. 7. A liquid flow path having a discharge port for discharging a liquid, a heating section communicating with the discharge port and applying a heat energy for discharging the liquid to the liquid, and generating the heat energy. A heating element for causing the heat acting portion to contact the liquid at least, and applying a drive pulse to the heating element in accordance with drive information, thereby generating heat from the heating element. An ink jet head that generates energy to generate bubbles in a liquid in the liquid flow path to discharge droplets, wherein the upper protective layer has the following composition formula (I): TaαFeβNiγCrδ (I) (However, 10 atomic% ≦ α ≦ 30 atomic% and α + β <
80 atomic%, α <β and δ> γ, and α +
β + γ + δ = 100 atomic%. An ink jet head comprising an amorphous alloy having the composition of (1), and having an ink containing an antifoaming agent as the liquid. 8. The ink jet head according to claim 7, wherein the defoaming agent contains a B-factor solvent. 9. The ink jet head according to claim 8, wherein the factor B solvent is at least one of glycerin and ethylene glycol. 10. In the composition formula (1), 10 at%
The ink jet head according to claim 7, wherein??? 20 atomic%. 11. The ink jet head according to claim 7, wherein γ ≧ 7 at% and δ ≧ 15 at% in the composition formula (1). 12. The ink jet head according to claim 11, wherein γ ≧ 8 at% and δ ≧ 17 at% in the composition formula (1). 13. The ink jet head according to claim 7, wherein at least a contact surface of said upper protective layer with the ink is covered with an oxide film as a component of said upper protective layer. 14. The ink jet head according to claim 13, wherein the oxide film is an oxide film mainly composed of Cr. 15. The film thickness of the oxide film is 5 nm or more and 3
The inkjet head according to claim 14, wherein the thickness is 0 nm or less. 16. The ink jet head according to claim 7, wherein the thickness of the upper protective layer is 10 nm or more and 500 nm or less. 17. The ink jet head according to claim 16, wherein the thickness of the upper protective layer is 50 nm or more and 200 nm or less. 18. The ink jet head according to claim 7, wherein said bubbles are generated by film boiling in said ink. 19. A liquid flow path having a discharge port for discharging a liquid, a heating section communicating with the discharge port, and applying heat energy for discharging the liquid to the liquid, and generating the heat energy. A heating element for causing an upper protective layer to form at least a contact surface of the heat acting portion with the liquid,
An ink jet that applies a drive pulse to the heating element according to the drive information, generates thermal energy from the heating element to generate bubbles in the liquid in the liquid flow path, and discharges droplets. An ink jet recording apparatus having a head, wherein the upper protective layer has the following composition formula (I): TaαFeβNiγCrδ (I) (provided that 10 atomic% ≦ α ≦ 30 atomic% and α + β <
80 atomic%, α <β and δ> γ, and α +
β + γ + δ = 100 atomic%. An ink jet recording apparatus comprising an amorphized alloy having the composition of (1), and having a drive pulse control means for applying a pulse for improving the defoaming pressure to the drive pulse applied to the heating element. 20. The ink jet recording apparatus according to claim 19, wherein the pulse for improving the defoaming pressure is a pre-pulse applied before a driving pulse. 21. In the composition formula (1), 10 at%
The inkjet recording apparatus according to claim 19, wherein ≦ α ≦ 20 atomic%. 22. The ink jet recording apparatus according to claim 19, wherein γ ≧ 7 at% and δ ≧ 15 at% in the composition formula (1). 23. The ink jet recording apparatus according to claim 22, wherein γ ≧ 8 atomic% and δ ≧ 17 atomic% in the composition formula (1). 24. The ink jet recording apparatus according to claim 19, wherein at least a contact surface of the upper protective layer with the ink is covered with an oxide film as a component of the upper protective layer. 25. The ink jet recording apparatus according to claim 24, wherein the oxide film is an oxide film mainly composed of Cr. 26. The oxide film has a thickness of 5 nm or more and 3
The ink jet recording apparatus according to claim 24 or 25, wherein the thickness is 0 nm or less. 27. The ink jet recording apparatus according to claim 19, wherein the thickness of the upper protective layer is 10 nm or more and 500 nm or less. 28. The ink jet recording apparatus according to claim 27, wherein the thickness of the upper protective layer is 50 nm or more and 200 nm or less. 29. The ink jet recording apparatus according to claim 19, wherein said bubbles are generated by film boiling in said liquid.