JP2003175614A - Fine particle-containing liquid jetting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate damage or wear of an ejection opening part by optimizing the hardness of the metallic material to be used in the case the ejection opening part of a fine particle-containing liquid jetting apparatus is made of a metal. <P>SOLUTION: In a fine particle-containing liquid jetting apparatus for ejecting a liquid with fine particles dispersed from a minute opening for adhering the same onto a member to be adhered, the opening is made of a metallic material harder than a resin material and the opening size is Φ25 μm or less in the case fine particles having a 0.02-0.6 μm particle size are used. Moreover, its hardness is at least 140 based on the Rockwell M scale. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid jet recording apparatus, and more particularly to a liquid jet recording apparatus using a recording liquid in which fine particles are dispersed.

[0002]

2. Description of the Related Art The non-impact recording method has recently attracted interest in that noise generation during recording is negligibly small. Among them, the so-called inkjet recording method, which is capable of high-speed recording and can perform recording without requiring a special fixing process on so-called plain paper, is
There are extremely powerful recording methods, some of which have been proposed and improved in the past, and some of which have been commercialized, while others are still being put into practical use.

In such an ink jet recording method, recording is performed by ejecting droplets of a recording liquid, which is so-called ink, and adhering the droplets to a recording member for recording. There are various methods as described below, depending on the generation method and the method for controlling the flight direction of the generated recording liquid droplets.

For example, in the case of the Tele type method (Patent Document 1), the droplets of the recording liquid are generated by electrostatic attraction, and the generated recording liquid droplets are subjected to an electric field control according to a recording signal. There is an electrostatic suction type in which a recording liquid droplet is selectively adhered to a recording member to perform recording.

Further, in the Sweet method (Patent Documents 2 and 3), a small droplet of the recording liquid of which the charge amount is controlled is generated by the continuous vibration generation method, and the generated charge amount of the controlled small amount is controlled. There are a continuous flow type and a charge control type in which recording is performed on a recording member by causing a droplet to fly between deflection electrodes to which a uniform electric field is applied.

In the Hertz method (Patent Document 4), an electric field is applied between the discharge port and the ring-shaped charging electrode,
There is a method of recording by generating and atomizing small droplets of a recording liquid by a continuous vibration generating method. That is, in this method, the atomization state of the droplet is controlled by modulating the electric field strength applied between the discharge port and the charging electrode in accordance with the recording signal, and the gradation of the recorded image is produced and recording is performed.

Further, there is a Stemme system (Patent Document 5). This method is fundamentally different in principle from the above three methods. That is, in all of the above-mentioned three methods, the droplets of the recording liquid ejected from the ejection port are electrically controlled during the flight, and the droplets carrying the recording signal are selectively deposited on the recording member. On the other hand, the Stemme method is used to perform recording by ejecting and ejecting a small droplet of recording liquid from an ejection port according to a recording signal. In other words, the Stemme method applies an electrical recording signal to a piezoelectric vibrating element attached to a recording head having a discharge port for ejecting a recording liquid, and converts this electrical recording signal into mechanical vibration of the piezoelectric vibrating element. Recording is performed by ejecting and ejecting small droplets of the recording liquid from the ejection ports according to the mechanical vibrations and adhering them to the recording member, which is a so-called drop-on-demand type.

Further, as another method, there is a method (Patent Document 6) previously proposed by the applicant in Japanese Patent Publication No. 56-9429. This method is also a so-called drop-on-demand type in which small droplets of a recording liquid are ejected and ejected from an ejection port according to a recording signal to perform recording, but the ink in the liquid chamber is heated to generate bubbles in the ink. The so-called,
It is called a bubble inkjet type.

As described above, the ink jet recording method is
There are various methods depending on the principle, but the common thing is that so-called ink droplets of a recording liquid are used.
t) is ejected and adhered to the recording member for recording. The recording liquid called this ink is generally a recording liquid in which a water-soluble dye is dissolved. However, in recent years, importance has been placed on water resistance and light resistance, and it is expected that a pigment having strong fastness will be used as a colorant for a recording liquid for inkjet recording.

For example, as water-based pigment inks for ink jets that meet the basic problems such as print quality, ejection characteristics, storage stability, and fixability, there are JP-A-2-255875 (Patent Document 7) and JP-A-4. -334870 (Patent Document 8), JP-A-4-57859 (Patent Document 9) and JP-A-4-57860 (Patent Document 1)
The ink described in 0) is disclosed.

However, the recording liquid in which the pigment is dispersed is scratched by removing the ink passage of the ink jet recording head when used for a long time as if river water containing gravel erodes mountains. Has the effect of attaching. If this is just an ink passage, some damage,
Although there is no problem with abrasion, damage and abrasion of the ejection port portion affect the ink droplet ejection performance, which is a problem.

In particular, in recent years, high quality and high accuracy of ink jet recording have been advanced, and the ejection port (nozzle) of the head used is conventionally Φ33 μm to Φ34 μm (about 900 μm ^{2 in} area) to Φ50 μm. Φ51 μm
(Area of about 2000 μm ² ) was common, but finer ejection ports (for example, Φ25 μm or less, less than 500 μm ² in terms of area) have been required. At that time, as in the conventional case, the one having a relatively large ejection port has almost no influence on the ink droplet ejection performance (ejection stability, ink mass uniformity, etc.) even if it is slightly damaged or worn. This is not a problem because it does not exist, but in the case of a finer ejection port (for example, Φ25 μm or less), the ink droplet ejection performance (ejection stability, ink mass uniformity) even with slight damage or abrasion. Etc.), which is a serious problem.

[0013]

[Patent Document 1] US Pat. No. 30,604,29

[Patent Document 2] US Pat. No. 3,596,275

[Patent Document 3] US Pat. No. 3,298,030

[Patent Document 4] US Pat. No. 3,416,153

[Patent Document 5] US Pat. No. 3,747,120

[Patent Document 6] Japanese Patent Publication No. 56-9429

[Patent Document 7] Japanese Patent Application Laid-Open No. 2-255875

[Patent Document 8] Japanese Patent Laid-Open No. 4-334870

[Patent Document 9] Japanese Unexamined Patent Publication No. 4-57859

[Patent Document 10] JP-A-4-57860

[0014]

DISCLOSURE OF THE INVENTION The present invention is used in a fine particle-containing liquid ejecting apparatus in which fine particles are ejected from a fine opening in which they are dispersed and adhered to an adherend when the ejection port portion is formed of metal. The purpose of this is to optimize the hardness of the metal material to be used, to prevent damage and wear of the ejection port portion, to prevent deterioration of droplet ejection performance, and to obtain stable ejection for a long period of time.

Alternatively, an ejection head used in a production machine such as the above-mentioned fine particle-containing liquid ejecting apparatus is
The purpose of this is to make it possible to semipermanently use the fine particle-containing liquid ejecting apparatus main body by using a replacement part and to reduce the total cost of the apparatus.

[0016]

DISCLOSURE OF THE INVENTION The present invention is a fine particle-containing liquid ejecting apparatus for ejecting a liquid in which fine particles are dispersed from a fine opening and adhering it to an adherend, the particle diameter of which is 0.02 μm to 0.0 When fine particles of 6 μm are used, the member forming the opening is made of a metal material harder than a resin material, and the opening diameter is Φ25 μm.
The hardness is at least 140 or more on the Rockwell M scale.

Further, the present invention is characterized in that the fine particle-containing liquid ejecting head used in the fine particle-containing liquid ejecting apparatus is detachably attached to the apparatus main body.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION First, the constitution and principle of an ink jet to which the present invention is applied will be explained. As mentioned above, there are various ink jet recording methods.
Here, a bubble ink jet type will be described as a typical example, but needless to say, the present invention is not limited to this method and is applicable to all ink jet recording methods.

FIG. 1 is a diagram for explaining an example of a bubble ink jet recording head. FIG. 1 (A) is a perspective view of the head, and FIG. 1 (B) is a perspective view of a lid substrate constituting the head.
FIG. 1C is a perspective view of the lid substrate viewed from the back side, and FIG.
(D) is a perspective view of a heating element substrate, in which 1 is a lid substrate, 2 is a heating element substrate, 3 is a recording liquid inlet, 4 is a discharge port, 5 is a flow path, and 6 is a liquid chamber. Area 7 for controlling, 7 is an individual (independent) control electrode, 8 is a common electrode, and 9 is a heating element.

The lid substrate 1 can be manufactured by forming the flow path 5 and the liquid chamber 6 on a glass substrate or a metal substrate by a method such as etching. The most preferable manufacturing method is forming by plastic molding. It is a technique. Although it costs a little to manufacture the first mold, since it can be mass-produced after that, the manufacturing cost per piece can be very low. At this time, in the present invention, as will be described later, by appropriately selecting the hardness of the plastic used, damage and wear of the portion of the ejection port 4 are eliminated, and stable ink droplet ejection is obtained. Even when the metal substrate is formed by etching or the like instead of forming the plastic, selecting a metal material having a hardness as described later eliminates damage and wear of the ejection port 4 and ensures stable ink droplet ejection. Needed to get.

FIG. 2 is a diagram for explaining the principle of ink droplet ejection of a bubble inkjet type inkjet. FIG. 2A shows a steady state in which the ink 10, the surface tension, and the external pressure are in equilibrium on the ejection port surface. Figure 2 (B)
Is heated until the heating element 9 is heated and the surface temperature of the heating element 9 rapidly rises to cause a boiling phenomenon in the adjacent ink layer, and the minute bubbles 11 are scattered.

FIG. 2C shows a state in which the adjacent ink layer that has been rapidly heated on the entire surface of the heating element 9 is instantly vaporized to form a boiling film and bubbles 11 are grown. At this time, the pressure inside the ejection port rises by the amount of the bubble that has grown, the balance with the external pressure on the ejection port surface is lost, and the ink column 10 'begins to grow from the ejection port.

FIG. 2D shows a state in which the bubble 11 has grown to the maximum, and ink corresponding to the volume of the bubble is pushed out from the ejection port surface. At this time, no current is flowing in the heating element 9, and the surface temperature of the heating element 9 is decreasing. The maximum value of the volume of the bubble 11 is slightly delayed from the timing of applying the electric pulse.

FIG. 2 (E) shows a state in which the bubble 11 is cooled by ink or the like and starts to contract. Ink column 1
At the tip of 0 ', move forward while maintaining the pushed speed,
At the rear end portion, the ink flows back from the ejection port surface into the ejection port due to the decrease in the ejection port internal pressure as the bubbles contract, and
There is a neck 10 "at 0 '.

In FIG. 2F, the bubble 11 is further contracted, the ink 10 is in contact with the surface of the heating element 9, and the surface of the heating element is further rapidly cooled. On the surface of the discharge port, the external pressure is higher than the internal pressure of the discharge port, so that a large meniscus enters the discharge port. Droplets 12 at the tip of the ink column
And flies toward the recording paper at a speed of 8 to 13 m / sec.

In FIG. 2G, the bubbles are completely extinguished during the process in which the ink is supplied (refilled) to the discharge port again by the capillary phenomenon and returns to the state of FIG. 2A.

3 is different from the head of FIG. 1 described above in that a nozzle plate 20 is separately provided at the tip of the flow path.
3A is a state before the nozzle plate 20 is attached, FIG.
(B) shows the state after attachment. In this case as well, this nozzle plate is formed in a resin (plastic) film by, for example, punching the nozzle 21 by an excimer laser, or by a method such as metal etching, electroforming, punching, etc. It is necessary to select the hardness appropriately as described later.

The above is the general structure and principle of the bubble ink jet recording head utilizing heat, but as described above, the present invention is not limited to this system and is applicable to all ink jet recording methods. It is what is done.

In the present invention, the recording liquid (ink) used in such an ink jet recording method uses a pigment having excellent water resistance and light resistance as a coloring agent for the recording liquid. However, when this pigment is used as a colorant for a recording liquid, the pigment is present like abrasive grains dispersed in a liquid medium, and when the ink is used in a large amount, the path of the ink in the inkjet head, There is a problem of damage and abrasion. In particular, scratches and abrasion of the ejection port portion are problematic because they affect the ink droplet ejection performance.

In order to solve this problem, the present invention has made diligent studies on the hardness of the material forming the ejection port portion, the ink flow rate, the pigment particle size at the nozzle portion, and the like. The black pigment ink suitably applied to the present invention includes, for example, a black pigment having a neutral or basic pH, an acrylic acid ester monomer or a acrylamide monomer having a tertiary amine salt or a quaternary ammonium group. Is a dispersion treatment using a water-soluble polymer having at least a component of
For inks such as yellow, magenta, and cyan,
The pigments of these hues are subjected to a dispersion treatment using an anionic polymer dispersant having a carboxyl group or a sulfone group as a water-soluble group.

The pH of the black pigment referred to here is generally the p value of the solution when the pigment is dispersed in pure water, as in the case of the method used to measure the physical properties of carbon black.
H value. When the recording material used for recording is plain paper, the interfacial tension of the ink with respect to the plain paper is such that the interfacial tension of the black pigment ink is higher than that of the color inks. In regard to the ink permeation rate with respect to, the permeation rate of the black pigment ink is preferably slower than that of the color inks.

When color recording is performed on plain paper using the above inks, an image with good fixability, high density and little boundary bleeding can be obtained. Further, a clear projected image can be obtained even when recording is performed on a recording material having transparency. And, needless to say, since it is a pigment ink, the resistance to light and water becomes very excellent as compared with the case of using a conventional dye ink.

The polymer dispersant used in the present invention is obtained mainly by polymerizing a vinyl monomer, and as the cationic monomer constituting at least a part of the obtained polymer, the following third monomer is used. Included are salts of secondary amine monomers and their quaternized compounds.

That is, N, N-dimethylaminoethyl methacrylate [CH2 = C (CH3) -COO-C2H4N (CH3) 2], N,
N-dimethylaminoethyl acrylate [CH2 = CH-COO-C
2H4N (CH3) 2], N, N-dimethylaminopropyl methacrylate [CH2 = C (CH3) -COO-C3H6N (CH3) 2], N, N-dimethylaminopropyl acrylate [CH2 = CH-COO-C3H6N
(CH3) 2], N, N-dimethylacrylamide [CH2 = CH-C
ON (CH3) 2], N, N-dimethylmethacrylamide [CH2 =
C (CH3) -CON (CH3) 2], N, N-dimethylaminoethyl acrylamide [CH2 = CH-CONHC2H4N (CH3) 2], N, N-dimethylaminoethyl methacrylamide [CH2 = C (CH3) -CON
HC2H4N (CH3) 2], N, N-dimethylaminopropylacrylamide [CH2 = CH-CONH-C3H6N (CH3) 2], N, N-dimethylaminopropylmethacrylamide [CH2 = C (CH3) -C
ONH-C3H6N (CH3) 2] and the like.

In the case of a tertiary amine, examples of the compound forming a salt include hydrochloric acid, sulfuric acid, acetic acid and the like.
Examples of the compound used for grading include methyl chloride, dimethylsulfate, benzyl chloride, epichlorohydrin and the like. Of these, methyl chloride, dimethylsulfate and the like are preferable for preparing the dispersant. The salt of the tertiary amine or the quaternary ammonium compound as described above behaves as a cation in water, and acid is a stable dissolution region under neutralized conditions. The content of these monomers in the copolymer is preferably in the range of 20 to 60% by weight.

Examples of the other monomer used in the constitution of the polymer dispersant include 2-hydroxyethyl methacrylate, acrylic acid ester having a hydroxy group such as acrylic acid ester having a long ethylene oxide chain as a side chain, Hydrophobic monomers such as styrene-based monomers, and water-soluble monomers soluble in water near pH 7 include acrylamides, vinyl ethers, vinylpyrrolidones, vinylpyridines, and vinyloxazolines. As the hydrophobic monomer, styrene,
Hydrophobic monomers such as styrene derivatives, vinylnaphthalene, vinylnaphthalene derivatives, alkyl esters of (meth) acrylic acid, and acrylonitrile are used. The water-soluble monomer in the polymer dispersant obtained by the copolymerization is used in order to make the copolymer stably exist in the aqueous solution.
The hydrophobic monomer is used in the range of 5 to 35% by weight.
20 to enhance the dispersion effect of the copolymer on the pigment.
It is preferably used in the range of 40% by weight.

The carbon black pigment (CI pigment black 7) used in the black ink of the present invention is # 2600, # 2300, # 990, # 980, #.
960, # 950, # 900, # 850, # 750, #
650, MCF-88, MA-600, # 95, # 5
5, # 52, # 47, # 45, # 45L, # 44, # 4
0, # 33, # 32, # 30, # 25, # 20, # 1
0, # 5 (Made by Mitsubishi Chemical), Printex95, Printex
90, Printex85, Printex80, Printex75, Print
ex45, Printex40, PrintexP, Printex60, Print
ex300, Printex30, Printex35, Printex25, P
rintex200, PrintexA, PrintexG, PrintexL6, P
rintexL (above, made by Degussa), Raven850, Raven7
80 ULTRA, Raven 760 ULTRA, Raven 790
ULTRA, Raven520, Raven500, Raven41
0, Raven420, Raven430, Raven450, Raven4
60, Raven 890, Raven 1020 (above, made in Colombia), Regal 415R, Regal 330R, Regal 250
R, Regal 995R, Monarch800, Monarch880,
Monarch900, Monarch460, Monarch280, Monar
ch120 (above, manufactured by Cabot) and the like.

Pigments used in the yellow ink include CI pigment yellow 1, CI pigment yellow 2, CI pigment yellow 3, CI pigment yellow 12, CI pigment yellow 13, CI pigment yellow 14, CI pigment yellow 16, and CI pigment yellow.
Pigment Yellow 17, CI Pigment Yellow 7
3, CI Pigment Yellow 74, CI Pigment Yellow 75, CI Pigment Yellow 83, CI Pigment Yellow 93, CI Pigment Yellow 95, CI Pigment Yellow 97, CI Pigment Yellow 98,
CI pigment yellow 114, CI pigment yellow 128, CI pigment yellow 129, CI pigment yellow 151, CI pigment yellow 154 and the like.

As pigments used in magenta ink, CI pigment red 5, CI pigment red 7, CI pigment red 12, CI pigment red 48 (Ca), CI pigment red 48 (Mn), C.I.
I. Pigment Red 57 (Ca), CI Pigment Red 57: 1, CI Pigment Red 112, CI Pigment Red 123, CI Pigment Red 168, CI
Pigment Red 184, CI Pigment Red 202
Etc.

As the pigment used in the cyan ink,
CI Pigment Blue 1, CI Pigment Blue 2, C.
I. Pigment Blue 3, CI Pigment Blue 15:
3, CI Pigment Blue 15:34, CI Pigment Blue 16, CI Pigment Blue 22, CI Pigment Blue 60, CI Vat Blue 4, CI Vat Blue 60 and the like.

In addition to the above, when intermediate colors other than the three primary colors such as red, green and blue are required, it is preferable to use the following pigments alone or in combination. For example, CI Pigment Red 209, CI Pigment Red 122, CI Pigment Red 224,
CI Pigment Red 177, CI Pigment Red 1
94, CI Pigment Orange 43, CI Bat Violet 3, CI Pigment Violet 19, CI Pigment Green 36, CI Pigment Green 7, CI
Pigment Violet 23, CI Pigment Violet 37, CI Pigment Blue 15: 6, CI Pigment Blue 209 and the like.

Further, the following dyes may coexist in the color ink. Examples of dyes used in yellow ink include CI Acid Yellow 1
1, CI Acid Yellow 17, CI Acid Yellow 23, CI Acid Yellow 25, CI Acid Yellow 29, CI Acid Yellow 42, CI Acid Yellow 49, CI Acid Yellow 61, CI Acid Yellow 71, CI Direct Yellow 12, CI Direct Yellow 24, CI Direct Yellow 26, CI
Direct Yellow 44, CI Direct Yellow 8
6, CI direct yellow 87, CI direct yellow 98, CI direct yellow 100, CI direct yellow 130, CI direct yellow 142 and the like.

As the dye used in the magenta ink, CI acid red 1, CI acid red 6, C.I.
I. Acid Red 8, CI Acid Red 32, CI Acid Red 35, CI Acid Red 37, CI Acid Red 51, CI Acid Red 52, CI Acid Red 80, CI Acid Red 85, CI Acid Red 87, CI Acid Red 92 , CI Acid Red 94, CI Acid Red 115, CI Acid Red 180, CI Acid Red 254, CI Acid Red 256, CI Acid Red 289, CI Acid Red 315, CI Acid Red 317, CI Direct Red 1, CI Direct Red 4 , CI Direct Red 13, CI Direct Red 17, CI Direct Red 23, CI Direct Red 28, CI Direct Red 31, CI Direct Red 62, CI
Direct Red 79, CI Direct Red 81, C.
I. Direct Red 83, CI Direct Red 89,
CI Direct Red 227, CI Direct Red 2
40, CI Direct Red 242, CI Direct Red 243 and the like.

The dye used in the cyan ink is
CI Acid Blue 9, CI Acid Blue 22, CI
Acid Blue 40, CI Acid Blue 59, CI Acid Blue 93, CI Acid Blue 102, CI Acid Blue 104, CI Acid Blue 113, CI
Acid Blue 117, CI Acid Blue 120, C.
I. Acid Blue 167, CI Acid Blue 229,
CI Acid Blue 234, CI Acid Blue 25
4, CI Direct Blue 6, CI Direct Blue 2
2, CI Direct Blue 25, CI Direct Blue 71, CI Direct Blue 78, CI Direct Blue 86, CI Direct Blue 90, CI Direct Blue 106, CI Direct Blue 199 and the like. However, even when these dyes coexist, the pigment particle size, the pigment content in the ink, and the like must be within the ranges described below.

In the present invention, when the above-mentioned cationic water-soluble polymer is used as a dispersant to disperse a pigment,
From the viewpoint of physical properties, preferred pigments are those having an isoelectric point adjusted to 6 or more, or those in which the pH of the simple aqueous dispersion characterizing the pigment has a neutral or basic pH, for example, 7 or more to 10 or less. Some pigments are preferable in terms of dispersibility. It is understood that this is because the ionic interaction force between the pigment and the cationic water-soluble polymer is strong.

In order to obtain a pigment fine particle aqueous dispersion using the above materials, it is preferable to employ the following method. (1) In the case of carbon black: Premixing treatment of carbon black in a cationic dispersant solution, followed by milling with a disperser having a high shear rate, and dilution, followed by centrifugation to remove coarse particles. . afterwards,
Ingredients for the desired ink formulation are added and optionally aged. After that, centrifugal treatment is performed to finally obtain a pigment dispersion having a desired average particle size. The pH of the ink thus produced is 3 to
A range of 9 is preferable.

(2) For pigments of other hues: Basically the same as carbon black except that an anionic dispersant is used. However, in the case of organic pigments where it is difficult to reduce the particle size, a surfactant treatment is applied at the same time as the pigment synthesis or during the synthesis process to suppress crystal growth of the pigment particles and improve the wettability. It is desirable to use pigments. The pH of the ink thus produced is preferably in the range of 5-10. The average particle size of both carbon black ink and color ink is 0.02 to 1
The range of μm is essential for the stability of the dispersion,
It is preferably in the range of 0.03 to 0.4 μm. This is an essential condition from the viewpoint of the stability of the dispersion, but from the viewpoint that it is essential for so-called inkjet, which discharges ink from a fine opening, it is necessary to examine the average particle size to find that the fine opening Clogs need to be taken into account, which will be discussed later. The surface tension of good ink is in the range of 10 to 60 dyn / cm.

When recording on plain paper using these inks, it is preferable that the black pigment ink has a high interfacial tension with the paper from the viewpoint of the clarity of the characters to be recorded. On the other hand, it is preferable that the color inks have a low interfacial tension with the paper, since it is preferable that the color inks have a high permeation rate in order to reduce bleeding (color bleeding) due to mutual diffusion between the color inks. As described above, when the black ink is acidic and has a high interfacial tension, and the color ink is basic and has a low interfacial tension, the black ink is less likely to flow into the color ink side and the black ink and the color ink Color bleed is virtually gone. The above-mentioned interfacial tension between the ink and the paper is measured, for example, by a device commercially available as a dynamic wettability tester (a device using the Wilhelmy method, product name WET-3000 manufactured by Resca Co., Ltd.) and the like. Is the amount. High interfacial tension means that the contact angle to plain paper is 90 ° or more even in a short time of 1 second to several seconds, and low interfacial tension means that it is 90 ° or less.

The dispersant used in the color ink used in the present invention is an alkali-soluble water-soluble oily resin and has a weight average molecular weight of 1,000 to 30,000, preferably 3,000 to 15, The range is 000. In particular,
Hydrophobic monomers such as styrene, styrene derivatives, vinylnaphthalene, vinylnaphthalene derivatives, alkyl esters of acrylic acid, alkyl esters of methacrylic acid,
Copolymers composed of hydrophilic monomers such as α, β-ethylenically unsaturated carboxylic acids and their aliphatic alcohol esters, acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaric acid and their derivatives, and salts thereof Is. The copolymer may have any structure such as random, block or graft, and the acid value is in the range of 100 to 430, preferably 130 to 360.

As the dispersant used in the present invention, water-soluble polymers such as polyvinyl alcohol and carboxymethyl cellulose, water-soluble resins such as naphthalene sulfonic acid formaldehyde condensate and polystyrene sulfonic acid can also be used. . However, the alkali-soluble water-soluble oil has the advantage that the viscosity of the dispersion liquid can be reduced and the dispersion is easy. The amount of these dispersants used is experimentally determined by using the selected pigment and dispersant, but the amount of the resin dissolved without adsorbing to the pigment is 4% by weight or less in the ink. It is preferable.

A base is required to use the above dispersant in an aqueous system. Suitable bases therefor include ethanolamine, diethanolamine, triethanolamine,
N-methylethanolamine, N-ethyldiethanolamine, 2-amino-2-methylpropanol, 2-ethyl-2-amino-1,3-propanediol, 2-
Organic bases such as (2-aminoethyl) ethanolamine, tris (hydroxymethyl) aminomethane, ammonia, piperidine, morpholine and β-dihydroxyethylurea, and inorganic bases such as sodium hydroxide, potassium hydroxide and lithium hydroxide Can be mentioned. The optimum base species varies depending on the type of pigment and dispersant selected, but is preferably non-volatile, stable and highly water-retaining. The amount of the base used is basically the amount calculated from the acid value of the dispersant, and each is used as the amount of base necessary for neutralizing it. In some cases, more than the equivalent amount of acid may be used. It is carried out for the purpose of improving dispersibility, adjusting pH of ink, adjusting recording performance, and improving moisturizing property.

The solvent used for the ink in the present invention is an organic solvent miscible with water. The organic solvent can be divided into three groups as described below. That is,
Highly moisturizing, hard to evaporate, hydrophilic first group solvent, good organic and hydrophobic surface wettability second solvent also evaporative dry, moderate wettability It is a low viscosity third group solvent (monohydric alcohols).

As the solvent belonging to the first group, ethylene glycol, diethylene glycol, triethylene glycol, tripropylene glycol, glycerin, 1,
2,4-butanetriol, 1,2,6-hexanetriol, 1,2,5-pentanetriol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, dimethylsulfoxide, dye Acetone alcohol, glycerin monoallyl ether, propylene glycol, butylene glycol, polyethylene glycol 300, thiodiglycol, N-methyl-2-pyrrolidone, 2-pyrrolidone, γ-butyrolactone, 1,3-
Dimethyl-2-imidazolidinone, sulfolane, trimethylolpropane, trimethylolethane, neopentyl glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monoallyl ether, diethylene glycol monomethyl ether, diethylene glycol Monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, β-dihydroxyethyl urea,
Urea, acetonylacetone, hentaerythritol,
1,4-cyclohexanediol etc. are mentioned.

Solvents belonging to the second group include hexylene glycol, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, ethylene glycol monophenyl ether, diethylene glycol diethyl ether, diethylene glycol monobutyl ether, diethylene glycol monoisobutyl. Ether, triethylene glycol monobutyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether Tell, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, glycerin monoacetate, glycerin diacetate, glycerin triacetate, ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether acetate, cyclohexanol, 1,2- Cyclohexanediol, 1-butanol, 3-methyl-1,5-pentanediol, 3-hexene-2,5-diol, 2,3-butanediol,
1,5-pentanediol, 2,4-pentanediol, 2,5-hexanediol and the like can be mentioned.

Examples of the solvent belonging to the third group include ethanol, n-propanol, 2-propanol, 1-methoxy-2-propanol, furfuryl alcohol, tetrahydrofurfuryl alcohol and the like. The total amount of the water-soluble solvent as described above is preferably used in the range of about 5 to 40% by weight based on the whole ink.

It is possible to add a surfactant, a pH adjusting agent, an antiseptic agent, etc. to each of the aqueous pigment inks constituting the ink of the present invention. Surfactants are useful for preparing highly penetrating color inks, heating heaters in bubble ink jet systems, and adjusting the wettability of the ejection nozzle surface. The material can be appropriately selected from existing commercial products. Summarizing the physical properties of each ink composed of the above materials, black ink has a high surface tension (approximately 3
It is preferable that the color ink has a low surface tension (approximately 10 to 40 dyn / cm).

As described above, when color recording is performed on plain paper using the black aqueous pigment ink and color ink of the present invention, black characters and the like are clear, and images and graphs and black characters are Even if they are next to each other, there is no mutual blurring and they are clear.

When the color ink of the present invention is used, the recording material may be any of ordinary plain paper (for example, high-quality paper, medium-quality paper or bond paper), coated paper, plastic film for OHP, etc. Can be used. As described above, the present invention can be applied to all ink jet recording methods, but is particularly suitable for use in an ink jet recording method of a type in which ink is ejected due to the bubbling phenomenon of ink due to thermal energy. Is extremely stable, and satellite dots are not generated. However, in this case, it may be necessary to adjust thermal properties such as specific gravity, coefficient of thermal expansion, and thermal conductivity.

Next, more characteristic points of the present invention will be described. As described above, the present invention relates to a so-called inkjet head recording method in which ink is ejected from a minute opening, and damage and abrasion of the ejection port portion caused by the pigment contained in the ink affect ink droplet ejection performance. It was made to solve it in order to exert.

In particular, in recent years, the high image quality and the high definition of ink jet recording have been advanced, and the ejection ports (nozzles) of the heads used are conventionally Φ33 μm to Φ34 μm (about 900 μm ^{2 in} area) to Φ50 μm to Φ51 μm. (Area of about 2000 μm ² ) was common, but finer ejection ports (for example, Φ25 μm or less, less than 500 μm ² in terms of area) have been required.

At that time, as in the conventional case, the discharge port diameter is relatively large.
If the value is large, even if there is some damage or wear,
Due to the large discharge port of
The wear rate is almost negligible and
For droplet discharge performance (jet stability, ink mass uniformity, etc.)
Has almost no effect and is not a problem. But
And a finer discharge port (for example, Φ25 μm or less, surface
The product is 500 μm ²Less than)
Even if it is damaged or worn, since it is a fine discharge port,
The proportion of damage and wear in that size cannot be ignored, and
Ink droplet ejection performance (jetting stability, ink mass uniformity, etc.)
Will be affected.

By the way, it is considered that such damage and wear of the discharge port can be avoided by appropriately selecting the hardness of the material forming the discharge port. The present invention pays attention to this point and experimentally investigates the relationship between hardness and damage and wear of various materials. Specifically, by using a head as shown in FIG. 3 and forming the nozzle plate by changing the material and ejecting ink for a certain period of time, it is determined whether or not the ejection port is damaged or worn. This is an examination of whether or not the drop ejection performance is deteriorated. The head used is shown in Figure 3.
The inkjet recording type head using the thermal energy having the structure as shown in FIG. 3, the one shown in FIG. 3 shows only four ejection ports for simplification of description. The number of ejection ports actually used was 128, and the arrangement density thereof was 400 dpi.

The size of the heating element is 22 μm × 90.
The resistance was 110 Ω, the drive voltage for ink ejection was 24 V, the drive pulse width was 6.5 μs, and the drive frequency was 12 kHz. For the ejection port portion (nozzle portion), an experiment was conducted by preparing a head in which a nozzle plate made of various resin materials or metal materials was changed. Further, the discharge port diameters were prepared to be Φ25 μm (H1) and Φ20 μm (H2).

As a comparative reference example, the discharge port diameter is Φ50 μm.
I also prepared the one (reference head). In this case, the number of discharge ports is 48 and the array density is 180 dpi. The size of this heating element is 40 μm × 180
The resistance was 120Ω, the driving voltage for ink ejection was 30 V, the driving pulse width was 7 μs, and the driving frequency was 1.8 kHz. Nozzle plate thickness is 40μ
m. The hardness of various materials was evaluated by Rockwell hardness, but the actual hardness is not measured with the nozzle plate, but a test piece is made with the same material as the material forming the nozzle plate. It was measured by

The materials used to form the nozzle plate are shown in Table 1 together with the hardness. Hardness was mainly shown on the Rockwell M scale, but some metal materials were shown on the B scale (B scale is applied to those harder than those indicated on the M scale).

[0066]

[Table 1]

The ink used had the following composition and production method, but had a pigment particle size of 0.02 to 1 μm.
What changed to m was prepared, and it tested by combining with the head from which the ejection port diameter differs, and the head from which the ejection port part material differs.

The method for producing the ink is described below. Acid value 265 consisting of styrene / acrylic acid / butyl acrylate,
Pigment Red 122 Dispersions D1 to D10 were prepared using an aqueous solution in which the copolymer P having a weight average molecular weight of 8,000 and a glass transition temperature of 67 ° C. was dissolved using ethanolamine. -Aqueous solution of copolymer P (solid content 15% by weight) 40 parts-Pigment Red 122 (Fast Gensueher Magenta RT, manufactured by Dainippon Ink) 24 parts-Diethylene glycol 20 parts-Isopropyl alcohol 10 parts-Water 130 parts

These materials were placed in a batch type vertical sand mill (made by AIMEX), filled with 1 mm diameter glass beads as a medium, and dispersed for 3 hours while cooling with water. A crude dispersion having a viscosity of 18 cp after dispersion and a pH of 9.5 was obtained. The dispersion was centrifuged to remove coarse particles, and various conditions of centrifugation were changed to obtain dispersions D1 to D7 in which the average particle diameter of the pigment was changed to 0.02 to 1 μm. This fine dispersion was diluted with water, diethylene glycol and ethylene glycol monobutyl ether (60:30:10 weight ratio) to give a viscosity of 3.3.
Magenta basic inkjet inks M1 to M7 having a cps, a surface tension of 35 dyne / cm and a pH of 9.3 were obtained. The solid content of the final preparation was about 7.5% by weight. The final pigment content in these inks is 5% by weight.
Is. The average particle size was measured by a particle size distribution measuring device ELS-800 (manufactured by Otsuka Electronics Co., Ltd.) by the dynamic light scattering method, and the average amount was shown by a value obtained from the initial slope of the autocorrelation function.

By combining these inks M1 to M7 with the above-mentioned heads having different ejection port diameters and heads having different ejection port materials, each ejection port has 5 × 10 ⁸ drops, and all 128 nozzles are ink. Droplets were discharged.
Then, Table 2, Table 3, and Table 4 show the results of examining whether or not the ejection port portion is damaged or worn immediately after and after the ejection is started, and as a result, the ink droplet ejection performance is deteriorated. . In the table, ○ indicates that the ejection opening was not damaged or worn, and the ink droplet ejection performance was not deteriorated. △ indicates that the ejection opening was damaged or worn, but the ink ejection performance was Deterioration did not occur, and x indicates that the ejection opening portion was damaged or worn, and the ink droplet ejection performance deteriorated.

[0071]

[Table 2]

[0072]

[Table 3]

[0073]

[Table 4]

From the above results, it can be seen that in the head having a large ejection port as in the comparative reference example, even if the ejection port portion is slightly damaged or worn, the ejection performance is not deteriorated. On the other hand, the discharge port diameter targeted by the present invention is Φ25μ.
If it is very fine as m or less, the damage or wear of the ejection port portion deteriorates the ink droplet ejection performance. Therefore, in order to perform stable ink droplet ejection, the ejection port portion may be damaged or worn. It can be seen that the conditions under which wear does not occur must be selected. The present invention is preferably applied even when the shape of the ejection port is not a circle but a rectangle or a trapezoid. In that case, Φ25 μm or less is equivalent to the area of about 500 μm.
It is less than m ² , and the present invention is applied to a discharge port having an area of less than about 500 μm ² even if it has a shape other than a circle.

Specifically, as can be seen from Tables 2 and 3, the resin material for forming the discharge port may be the material of 65 to 120 (S3 to S11) on the Rockwell M scale. In addition, an ink having a pigment particle size of 0.02 μm to 0.2 μm may be used. In addition, sample S1,
Even if it is less than 65 on the Rockwell M scale as in S2, the ink droplet ejection performance will not deteriorate if an ink having a pigment particle size of 0.02 μm is used, but the usable ink is very limited, Not very practical.

Further, in the case where the material forming the ejection port portion is a metal, if the material having the same hardness as the resin, such as the sample S12, can be used in the range in which the ink droplet ejection performance does not deteriorate. The range of (pigment particle size) is about the same as that of the resin, but it is much harder than the resin.
It can be seen that the range of inks (pigment particle size) that can be used is wide as long as ink droplet ejection performance does not deteriorate. That is,
It is possible to use an ink having a pigment particle size of 0.02 μm to 0.6 μm.

Next, another feature of the present invention will be described. As described above, the present invention uses the pigment ink, but from the above results, it was found that the pigment can be prevented from being damaged or worn by appropriately selecting the hardness of the ejection port. . However, considering that the pigment acts like an abrasive grain, if the hardness of the ejection port is properly selected, no damage or wear will occur even if the number of ink droplet ejections becomes infinite. Is hard to think of. Therefore, here, when such a pigment ink is ejected, how many times the ejection is possible without deterioration of the ink droplet ejection performance was investigated.

The ink used in the experiment was appropriately selected from the same inks and heads as those described above, and the ink was ejected when deterioration started to occur by continuously driving the head and periodically checking the ink droplet ejection performance. The number of droplets discharged (the number of discharged droplets) was examined. It should be noted that this number of times is the number of ejected droplets of ink droplets ejected per one ejection port. Also,
Driving conditions and the like are the same as in the above-mentioned experiment. The results are shown in Table 5.
~ Shown in Table 10. In the table, ○ indicates that the ejection opening was not damaged or worn, and the ink droplet ejection performance did not deteriorate.
△ indicates that the ejection opening was damaged or worn, but the ink droplet ejection performance was not deteriorated, and × is that the ejection opening was damaged or worn, and the ink droplet ejection performance was deteriorated. is there.

[0079]

[Table 5]

[0080]

[Table 6]

[0081]

[Table 7]

[0082]

[Table 8]

[0083]

[Table 9]

[0084]

[Table 10]

From the above results, it is understood that when the material of the ejection port is resin, the total number of droplets ejected from the ejection port needs to be 5 × 10 ⁸ or less per ejection port. Further, when the material of the ejection port is made of a metal harder than the resin, the total number of droplets ejected from the ejection port is significantly increased as compared with the case of the resin, and up to 5 × 10 ⁹ per ejection port,
It can be seen that the ink droplet ejection performance does not deteriorate.

FIG. 4 is a schematic perspective view showing an example of a liquid jet recording apparatus to which the present invention is applied.
2 shows a carriage 31 attached to the printer body 30 and a recording head unit 40 detachably mounted on the carriage 31. Here, the recording head unit 40 is being replaced from the printer body 30.

The recording head unit 40 shown in FIG.
The configuration is shown in FIG. 5. The recording head unit 50 is fixed to the ink container unit 60 to form a unit, and the recording head unit 50 is a flexible printed wiring board fixed to the upper part of the ink container unit 60. It is formed by the (FPCB) 51 and the head chip 52. This head chip 52 is shown in FIG. 6 (perspective view) and FIG. 7 (exploded perspective view).
As shown in FIG.
4 on the heating element substrate 53, and a heating element 55,
A common electrode 56 and a control electrode 57 are formed.

FIG. 8 is an exploded view of the recording head unit shown in FIG.
0 is filled with ink to be supplied, and a sponge-like absorber 61 impregnated with the ink is stored.
If the orifice plate 54 is made of resin, for example, a material having a hardness within the specific range described above is selected, and the orifice plate 54 is formed on the resin film by excimer laser processing or the like. Similarly, when formed of a metal, a material having a hardness within a certain range is selected,
For example, it is formed by electroforming of nickel, etching or punching on a stainless substrate.

When the orifice plate 54 is attached to the heating element substrate 53, nozzles 58 which serve as ink ejection ports are formed at positions facing the heating element 55. The nozzles 58 are arranged in two rows on the orifice plate 54 with a predetermined interval. The flexible printed wiring board 51 fixed to the ink container portion 60 and the head chip 52 are electrically connected by wire bonding. The flexible printed wiring board 51 is provided with electrical contacts for inputting image recording information from the printer body 30 side when the recording head unit 40 is mounted on the printer body 30.

As described above, according to the present invention, it is known that the total number of droplets discharged from the discharge port may be set to a certain value or less in order to prevent deterioration of ink droplet discharge performance. That is, the total amount of ink used by the recording head should be set to a certain value or less.

Specifically, for example, if the recording head section 40 as shown in FIG. 5 is fixed to the ink container section 60 and unitized, the capacity of the ink container section 60 is set to 1
The mass of the droplets × the number of ejected droplets (for example, 5 × 10 ⁸ ) × the total number of ejection openings (for example, 128 nozzles) may be set. However, since the same number of ink droplets are not ejected from all the ejection ports, it is preferable to set the value to be 20% to 30% less than the value calculated by the above formula in consideration of safety in practice. .

More specifically, the number of nozzles is 100 to 50.
If the number is 0, the maximum capacity of the ink container is 50.
Setting it to 00 cc or less is a practical value in consideration of the load on the carriage. That is, if the total amount of ink is set to such a capacity or less and the ink is used up, the recording head unit 40 is replaced as shown in FIG. Thus, high quality recording can be obtained.

In FIG. 9, the recording head unit 50 as shown in FIG. 5 is fixed to a base 70 which is removable and replaceable, and the unitized recording head unit 50 is removable and replaceable with respect to the ink container unit 60. It is what 10 is a sectional view thereof, and FIG. 11 is an exploded perspective view thereof. The ink container part 60 is detachably connected to the recording head part 50. A guide convex portion 62 for this connection is formed on the upper surface of the ink container part 60, and a guide is provided on the base body 70. A guide concave portion 71 that slidably engages and holds the convex portion 62 is formed. Then, the guide convex portion 62 and the guide concave portion 71 are engaged with each other and the ink container 60 is pushed all the way in, whereby the recording head portion 50 and the ink container portion 60 are separated from each other as shown in FIGS. 9 and 10. The connection is complete.

A hole portion 63 for supplying the stored ink to the liquid chamber 72 is formed in the ink container portion 60, and a ring-shaped elastic member 64 is fitted in the hole portion 63. On the other hand, a pipe-shaped member 73 that is inserted into the ink container portion 60 from the hole 64a of the elastic member 64 when the ink container portion 60 is connected to the recording head portion 50 is formed on the base body 70. An ink introduction path 74 formed inside 73 is communicated with the liquid chamber. Here, the elastic member 64 is used when the ink container portion 60 is connected to the recording head portion 50 and the recording head portion 50 and the ink container portion 60.
And 10 with the intervention.
It is designed with a 20% crushing allowance.

Further, a stainless mesh filter 75 is attached to the tip of the pipe-shaped member 73 inserted into the ink container portion 60. A hole 64 is formed in the ink container portion 60 before the connection to the recording head portion 50.
A stopper (not shown) for closing a is attached, and the stopper is removed immediately before connecting the ink container portion 60 to the recording head portion 50.

Further, the ink container portion 60 is formed with a minute opening 65 for preventing the pressure drop inside the ink container portion 60 due to the decrease of the ink by communicating the inside with the atmosphere. In this way, the ink container unit 60 is freely attached to and detached from the recording head unit 50, so that only the ink container unit 60 needs to be replaced when ink runs out.
The running cost can be reduced. In that case, the recording head unit 50 is left as it is, and the ink container unit 6 is
0 is replaced a plurality of times, and the number of times of this replacement is equal to the ink capacity of the ink container unit 60 multiplied by the total ink amount of the plurality of times (total amount of ink used by the recording head (damage or abrasion of the ejection port). The amount used within the range that does not occur) or less.

By doing so, high quality recording can always be obtained without deterioration of ink droplet ejection performance. Incidentally, when the number of times exceeds this number, the recording head section 40 is also replaced as a matter of course.

According to the above description, in the present invention, when the ejection port is formed of a resin material having low hardness, the recording head unit is replaced after ejecting a certain amount of ink as shown in FIG. On the other hand, when the ejection port is made of a metal harder than resin, it is possible to eject a considerable amount of ink before the ejection port is damaged or worn.

From the above experimental results, when the material of the ejection port is made of a metal harder than the resin, the total number of droplets ejected from the ejection port is greatly increased as compared with the case of the resin, and one ejection port It is known that the ink droplet ejection performance does not deteriorate up to 5 × 10 ⁹ . Actually, ejecting ink droplets up to this number of drops is almost equivalent to the end of life of the printer body. In such a case, the recording head unit is fixed to the printer carriage unit, Need not be replaced, but only the ink container part needs to be replaced, whereby the running cost can be reduced.

Although the above description has been made with reference to the example of the bubble ink jet, the present invention is not limited to this and is applied to all ink jets having a fine ejection port and using a pigment ink. It is a thing. In addition, although the recording head example is also described by using an example of a single color ink,
It goes without saying that it can also be applied to color inkjet.

[0101]

According to the present invention, a fine particle-containing liquid ejecting apparatus for ejecting fine particles in which fine particles are dispersed and adhering it to an adherend is used when the member including the ejection port portion is made of metal. By optimizing the hardness of the metal material to be used, there is no damage or wear on the discharge port, deterioration of droplet ejection performance is eliminated, and stable ejection can be obtained for a long period of time.

Further, since the jet head used in the production machine such as the fine particle-containing liquid jet apparatus as described above can be used semipermanently by replacing the jet head with a replacement part, the total cost of the apparatus is reduced. It can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an example of a bubble inkjet recording head.

FIG. 2 is a diagram for explaining the principle of ink droplet ejection of a bubble inkjet type inkjet.

FIG. 3 is a diagram showing an inkjet recording type head that uses thermal energy.

FIG. 4 is a schematic configuration diagram showing an example of a liquid jet recording apparatus to which the present invention is applied.

5 is an overall perspective view of the recording head unit shown in FIG.

6 is a perspective view showing an example of a head chip of the recording head unit shown in FIG.

7 is an exploded perspective view of the head chip shown in FIG.

FIG. 8 is an exploded perspective view of the recording head unit shown in FIG.

FIG. 9 is a perspective view showing an example of a case where the recording head shown in FIG. 5 is fixed to an ink container to form a unit.

FIG. 10 is a sectional view of the recording head unit shown in FIG.

FIG. 11 is an exploded perspective view of the recording head unit shown in FIG.

[Explanation of symbols]

1 ... Lid substrate, 2 ... Heating element substrate, 3 ... Recording liquid inlet, 4
... Ejection port, 5 ... Flow channel, 6 ... Common liquid chamber, 7 ... Individual lead electrode, 8 ... Common lead electrode, 9 ... Heating element, 10 ... Ink, 11 ... Bubble, 12 ... Droplet, 20 ... Nozzle plate ,
21 ... Nozzle, 30 ... Printer main body, 31 ... Carriage, 40 ... Recording head unit, 50 ... Recording head, 5
DESCRIPTION OF SYMBOLS 1 ... Flexible printed wiring part, 52 ... Head chip, 53 ... Heating element substrate, 54 ... Orifice plate, 5
5 ... Heating element, 56 ... Common electrode, 57 ... Control electrode, 60 ...
Ink container part, 61 ... Ink absorber, 62 ... Guide convex part, 63 ... Hole, 64 ... Elastic member, 64a ... Elastic member 64
, 65 ... Micro openings, 70 ... Substrate, 71 ... Guide recess, 72 ... Liquid chamber, 73 ... Pipe member, 74 ... Ink introducing section, 75 ... Filter.

Claims (2)

[Claims] 1. In a fine particle-containing liquid ejecting apparatus for ejecting a liquid in which fine particles are dispersed from a fine opening and adhering it to an adherend, when fine particles having a particle diameter of 0.02 μm to 0.6 μm are used, The opening is characterized in that the member forming the opening is made of a metal material harder than a resin material, the opening diameter is Φ25 μm or less, and at least the hardness is 140 or more on the Rockwell M scale. Liquid ejecting apparatus containing fine particles. 2. An ejecting head, which is used in the liquid ejecting apparatus containing fine particles according to claim 1, and ejects liquid droplets detachable from the apparatus.