JP2006160998A - Ink, inkjet recording method, recording unit, ink cartridge and inkjet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide ink, especially a black ink having good black color reproductivity in various kinds of materials to be recorded, hardly causing discoloration problems even when a photograph-tone image is formed on a coated paper, and providing excellent gas resistance to a formed image. <P>SOLUTION: The ink contains at least a coloring material represented by general formula (I) and a coloring material represented by general formula (II). The inkjet recording method, the recording unit, the ink cartridge and the inkjet recording device are also provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to ink, particularly black ink, and ink that can be suitably used for an ink jet recording system in which ink is ejected from an orifice in accordance with a recording signal to perform recording on a recording material, and an ink jet recording method using these inks The present invention relates to a recording unit, an ink cartridge, and an ink jet recording apparatus.

  The ink jet recording system is widely used as a means for easily forming a color image, particularly in offices and personal use. The ink used in such an ink jet recording system has high storage stability, does not cause clogging of the discharge orifice, and has problems such as a blurring of a recorded image at the start of recording after standing for a long time after continuous printing. Ink performance for adapting to the recording method, such as not causing it, is required. Furthermore, the quality performance with respect to the recording image formed with ink, such as being excellent in color tone reproducibility and giving an image with high optical density and clear color tone, is required.

  Of the inks used in the ink jet recording system, black ink is an important ink that is used for full-color images as well as mono-color images. Examples of the dye used in such a black ink include C.I. I. Various structural types of dyes have been used, including Food Black 2 (see, for example, Patent Document 1).

By the way, in recent years, image quality improvement of inkjet recording images has progressed, and it has become possible to realize high-quality recording images comparable to silver salt photographs. For this reason, a higher level of recorded image performance is required for inkjet recorded images, and the image quality is not limited to the natural quality of the image, and the image may cause a thigh color with respect to sunlight or various illumination lights. no excellent light resistance and image fastness is also required such excellent gas resistance, without causing strange thigh color by oxidizing gas (ozone, nO _X, SO _X, etc.) contained in trace amounts in the atmosphere It is like that.

  Conventionally, image fastness has been mainly regarded as a problem of fading due to sunlight or various illumination lights, and the problem of these fading has been solved by selecting a dye having excellent light resistance. However, recently, in addition to these fading problems, the problem of image discoloration has been highlighted. That is, an ink jet recorded image formed with a conventional ink can not only prevent discoloration of an image but also prevent occurrence of discoloration particularly in a recorded matter such as image information, for example, a photographic tone color recorded matter. It has become an important issue. Here, the discoloration means that the hue does not change so much but the hue changes.

In particular, in black ink images, it is a serious problem that black color changes to brown, and in the case of a full color image, the image quality rapidly deteriorates due to this color change. This discoloration problem is the influence of an oxidizing gas contained in trace amounts (ozone, NO _X, SO _X, etc.) is large, proceeds even in an environment not exposed to sunlight or various illumination light to the atmosphere. According to the study by the present inventors, in particular, so-called coated paper in which an ink receiving layer containing a pigment and a binder is formed on a substrate such as paper in order to increase the sharpness, color tone reproducibility, and optical density of the ink. When recording on plain paper, significant discoloration occurs even if ink is used which has little problem of discoloration when recorded on plain paper. Therefore, in particular, in order to effectively prevent discoloration of an image when recorded on coated paper, it is desired to develop an ink in which the formed image has excellent gas resistance.

  For the above technical problems, color tone and discoloration resistance against ozone gas have been improved so far (see, for example, Patent Documents 2 and 3), but the image quality is comparable to silver salt photography. In recent inkjet recording systems capable of obtaining a recorded image, it has been recognized that it is still necessary to further improve the color tone of the image formed with black ink and the gas resistance of the image.

JP 59-93766 A Japanese Patent No. 2919615 Japanese Patent Publication No. 8-26263

  Therefore, an object of the present invention is to provide an image formed with good black reproducibility on various recording materials, and further, even when a photographic image is formed on a coated paper, no problem of discoloration occurs. An object of the present invention is to provide an ink capable of providing excellent gas resistance. In particular, it is to provide a black ink, and further to provide an ink that satisfies the basic performance required for an inkjet recording ink.

  Another object of the present invention is to provide a recording method capable of obtaining a black image that has an excellent color tone and does not easily fade. It is a further object of the present invention to provide a recording unit, an ink cartridge, and an ink jet recording apparatus using this black ink.

The above object is achieved by the present invention described below. That is, the present invention is an ink comprising at least a color material represented by the general formula (I) and a color material represented by the general formula (II).

（上記一般式（Ｉ）中、Ｒ₁及びＲ₂は各々独立に、置換若しくは未置換の炭素数１〜４のアルキル基を表し、且つ、少なくともＲ₁及びＲ₂のいずれかは、１の水酸基を有するアルキル基である。Ｒ₃は、水素原子、或いは、置換若しくは未置換のフェニル基を表す。Ｘ₁は、カルボキシル基又はスルホン酸基、若しくは、それらのアルカリ金属塩、アンモニウム塩、有機アンモニウムの塩のいずれかを表す。ｍは１又は２を表す。Ｍはスルホン酸基の対イオンであり、アルカリ金属、アンモニウム及び有機アンモニウムのいずれかを表す。）

(In the general formula (I), R ₁ and R ₂ each independently represents a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, and at least _one of R ₁ and R ₂ is 1 An alkyl group having a hydroxyl group, R ₃ represents a hydrogen atom or a substituted or unsubstituted phenyl group, and X ₁ is a carboxyl group or a sulfonic acid group, or an alkali metal salt, ammonium salt, or organic group thereof. Represents any one of ammonium salts, m represents 1 or 2. M represents a counter ion of a sulfonic acid group, and represents any of alkali metal, ammonium and organic ammonium.)

（上記一般式（II）中、Ｒ₄及びＲ₅は各々独立に、水素原子、炭素数１〜４のアルキル基、炭素数１〜４のアルコキシ基、炭素数２〜４のアルカノイルアミノ基及びアルコキシ（炭素数１〜４）−アルコキシ（炭素数１〜４）基のいずれかを表し、且つ、Ｒ₄及びＲ₅の少なくとも一方は炭素数１〜４のアルコキシ基である。Ｒ₆は、水素原子、若しくは、置換若しくは未置換の、フェニル基、ベンゾイル基及びベンジル基のいずれかを表す。Ｘ₂は、カルボキシル基又はスルホン酸基、若しくは、それらのアルカリ金属塩、アンモニウム塩、有機アンモニウム塩のいずれかを表す。ｎは１又は２を表す。Ｍはスルホン酸基の対イオンであり、アルカリ金属、アンモニウム或いは有機アンモニウムのいずれかを表す。）

(In the general formula (II), R ₄ and R ₅ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an alkanoylamino group having 2 to 4 carbon atoms, and alkoxy (1-4 carbon atoms) - alkoxy represents one of (1 to 4 carbon atoms) group, and, .R ₆ at least one of R ₄ and R ₅ is an alkoxy group having 1 to 4 carbon atoms, Represents a hydrogen atom or a substituted or unsubstituted phenyl group, benzoyl group or benzyl group, X ₂ represents a carboxyl group or a sulfonic acid group, or an alkali metal salt, ammonium salt or organic ammonium salt thereof; N represents 1 or 2. M is a counter ion of the sulfonic acid group, and represents any one of alkali metal, ammonium, and organic ammonium.)

  Another embodiment of the present invention includes an ink jet recording method for forming an image using the ink according to the present invention having the above configuration, or a recording unit, an ink cartridge, and an ink jet recording apparatus equipped with the ink according to the present invention. .

  According to the present invention, a clear black tone image can be obtained when printing on various recording papers such as coated paper as well as plain paper, and in particular, excellent gas resistance with suppressed discoloration and discoloration. Ink is provided that can provide the image. Furthermore, according to the present invention, an ink that can be suitably used in an ink jet recording method and a recording apparatus is provided.

  Hereinafter, the present invention will be described in more detail with reference to preferred embodiments. In view of the above-described problems of the prior art, the present inventors have made various studies on the ink composition and the like. In the process, an ink containing the color material represented by the general formula (I) and the color material represented by the general formula (II) was prepared, and the obtained ink was evaluated, and this ink The images formed by the above were evaluated. As a result, this ink has an excellent color that can be used for photographic image formation, and the image is discolored or discolored even when exposed to an oxidizing gas such as ozone. The present invention was found by finding that the image is extremely excellent in gas resistance. Further, the above-described ink satisfies the ink jet recording characteristics at a high level and is found to be useful for ink jet recording, and has led to the present invention. Hereinafter, the coloring material characterizing the ink according to the present invention, and the aqueous medium in which the coloring material is dissolved or dispersed will be described.

[Color material]
The ink according to the present invention has both the first color material represented by the following general formula (I) and the second color material represented by the following general formula (II) as color materials.

（上記一般式（Ｉ）中、Ｒ₁及びＲ₂は各々独立に、置換若しくは未置換の炭素数１〜４のアルキル基を表し、少なくともＲ₁及びＲ₂のいずれかは、且つ、その基の中に１の水酸基を有する。Ｒ₃は、水素原子、或いは、置換若しくは未置換のフェニル基を表す。Ｘ₁は、カルボキシル基又はスルホン酸基、若しくは、それらのアルカリ金属塩、アンモニウム塩、有機アンモニウムの塩のいずれかを表す。ｍは１又は２を表す。Ｍはスルホン酸基の対イオンであり、アルカリ金属、アンモニウム及び有機アンモニウムのいずれかを表す。） (First color material)

(In the above general formula (I), R ₁ and R ₂ each independently represents a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, and at least _one of R ₁ and R ₂ is a group thereof. In which R ₃ represents a hydrogen atom or a substituted or unsubstituted phenyl group, X ₁ represents a carboxyl group or a sulfonic acid group, or an alkali metal salt, ammonium salt thereof, (M represents an organic ammonium salt, m represents 1 or 2. M represents a counter ion of a sulfonic acid group, and represents an alkali metal, ammonium, or organic ammonium.)

R _{1 to} R ₃ in the general formula (I) will be described more specifically. In the formula, R ₁ and R ₂ each independently represent a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, and any of the alkyl groups of R ₁ and R ₂ has one hydroxyl group. Examples of the substituent of the alkyl group include a linear or branched alkoxyl group having 1 to 4 carbon atoms, an amino group, or a halogen atom (fluorine, chlorine, bromine, etc.). R ₃ in the formula represents a hydrogen atom or a substituted or unsubstituted phenyl group. Examples of the substituent of the phenyl group include a linear or branched alkyl group having 1 to 4 carbon atoms, a sulfone group, a carboxyl group, or an alkali metal salt, ammonium salt, or organic ammonium salt thereof. It is done. Examples of X ₁ in the general formula (I) include —COOM and —SO ₃ M. Here, M is an alkali metal (for example, Li, Na, etc.), ammonium (NH ₄ ), organic ammonium, or the like.

（上記一般式（II）中、Ｒ₄及びＲ₅は各々独立に、水素原子、炭素数１〜４のアルキル基、炭素数１〜４のアルコキシ基、炭素数２〜４のアルカノイルアミノ基及びアルコキシ（炭素数１〜４）−アルコキシ（炭素数１〜４）基のいずれかを表し、且つ、Ｒ₄及びＲ₅の少なくとも一方は炭素数１〜４のアルコキシ基である。Ｒ₆は、水素原子、若しくは、置換若しくは未置換の、フェニル基、ベンゾイル基及びベンジル基のいずれかを表す。Ｘ₂は、カルボキシル基又はスルホン酸基、若しくは、それらのアルカリ金属塩、アンモニウム塩、有機アンモニウム塩のいずれかを表す。ｎは１又は２を表す。Ｍはスルホン酸基の対イオンであり、アルカリ金属、アンモニウム或いは有機アンモニウムのいずれかを表す。） (Second color material)

(In the general formula (II), R ₄ and R ₅ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an alkanoylamino group having 2 to 4 carbon atoms, and alkoxy (1-4 carbon atoms) - alkoxy represents one of (1 to 4 carbon atoms) group, and, .R ₆ at least one of R ₄ and R ₅ is an alkoxy group having 1 to 4 carbon atoms, Represents a hydrogen atom or a substituted or unsubstituted phenyl group, benzoyl group or benzyl group, X ₂ represents a carboxyl group or a sulfonic acid group, or an alkali metal salt, ammonium salt or organic ammonium salt thereof; N represents 1 or 2. M is a counter ion of the sulfonic acid group, and represents any one of alkali metal, ammonium, and organic ammonium.)

R ₆ in the general formula (II) will be described in detail. R ₆ represents any one of a hydrogen atom, a substituted or unsubstituted phenyl group, a benzoyl group, and a benzyl group, and examples of the substituent such as a phenyl group include a linear or branched group having 1 to 4 carbon atoms. Examples thereof include a chain alkyl group, a sulfone group, a carboxyl group, or a salt thereof. Examples of X ₂ include —COOM and —SO ₃ M. At this time, examples of M include alkali metals (for example, Li and Na), ammonium (NH ₄ ), and organic ammonium.

  The image obtained by the ink according to the present invention containing the first and second colorants represented by the above general formulas (I) and (II) exhibits a very excellent color tone and is further excellent. Shows ozone resistance (gas resistance).

(Specific example of the first coloring material)
Specific examples of the first coloring material represented by the general formula (I) include exemplified compounds 1 to 5 below. However, this invention is not limited to this, For example, the compound of the structure etc. which are described in the international publication 00/43451 pamphlet are mentioned. Two or more types of the first colorant represented by the general formula (I) as shown below may be used at the same time.

(Specific example of the second coloring material)
Specific examples of the coloring material represented by the general formula (II) used in the present invention include compounds such as the following exemplified compounds 6 to 9. The second color material used in the present invention is not limited to these. Further, in the ink according to the present invention, two or more kinds of color materials as listed below may be used at the same time.

  The ratio of the first color material represented by the general formula (I) and the second color material represented by the general formula (II) to be contained in the ink according to the present invention is determined by the first color material. In consideration of the effect that a clear color tone, sufficient image density, and an image having excellent ozone resistance can be obtained by using an ink in combination with the second color material, The mixing ratio (first color material: second color material) of the first color material represented by the general formula (I) and the second color material represented by the general formula (II) is expressed by a mass ratio. , 8: 2 to 2: 8 is preferably used in combination. Further, the content of all the color materials in the ink containing these color materials is in the range of 1.0 to 15.0% by mass, particularly 4.0 to 10.0% by mass, based on the total amount of the ink. It is preferable to do so.

[Aqueous medium]
The ink according to the present invention is obtained by dissolving or dispersing the first and second color materials described above in an aqueous medium. As the aqueous medium, water or a mixture of water and a water-soluble organic solvent is used. It is preferable to use a medium. The water-soluble organic solvent that can be used in this case is not particularly limited as long as it exhibits water-solubility. For example, alcohol, polyhydric alcohol, polyglycol, glycol ether, nitrogen-containing polar solvent, sulfur-containing polar solvent, etc. Is mentioned. The content of these water-soluble organic solvents is in the range of 1 to 40% by mass of the whole ink in consideration of maintaining the moisture retention of the ink, improving the solubility of the coloring material, and effectively penetrating the ink into the recording paper. Preferably, it is in the range of 3 to 30% by mass. In addition, the content of water in the ink is good so that the colorant has good solubility in the ink, has a viscosity for stable ink ejection, and does not cause clogging at the nozzle tip. Is preferably in the range of 30 to 95% by mass.

[Additive]
In addition, in the ink according to the present invention, a moisturizing solid content such as urea, a urea derivative, or trimethylolpropane may be included as a component of the ink as needed in order to maintain the moisturizing property of the ink. In general, the content of moisturizing solids such as urea, urea derivatives, and trimethylolpropane in the ink is preferably in the range of 0.1 to 20.0% by mass, more preferably, based on the total amount of the ink. It is the range of 3.0-10.0 mass%. Furthermore, in addition to the above components, the ink according to the present invention includes a surfactant, a pH adjuster, a rust inhibitor, an antiseptic, an antifungal agent, an antioxidant, an anti-reduction agent, and an evaporation accelerator as necessary. Various additives such as a chelating agent and a water-soluble polymer may be contained.

[Ink containing third color material]
Furthermore, as another form of the ink according to the present invention, a yellow dye is used as the third color material in addition to the ink of the form containing the first and second specific color materials described above. Examples thereof include inks contained therein. Hereinafter, the ink of such a form will be described. The ink according to the present invention configured as described above can be obtained by adding a yellow dye as the third color material to the first and second color materials mentioned above, so that an image formed by the ink can be obtained. Of course, it exhibits excellent ozone resistance, as well as more excellent color tone. The yellow dye content is preferably in the range of 1 to 20% on a mass basis with respect to the total content of all colorants in the ink.

  As described above, as the third color material, a yellow dye, more preferably C.I. I. Direct Yellow 86 and C.I. I. The color tone of the image with the ink containing at least one of the Direct Yellow 132 is particularly excellent. Such an ink according to the above-mentioned form capable of forming an image having a more excellent color tone as well as high ozone resistance is, for example, a high quality comparable to a silver salt photograph in which reproduction of a delicate color tone is particularly required. As a black ink for an ink jet printer used for printing a clear image, it can be used very suitably.

  In the ink of the present invention containing the first to third color materials described above, the amount (A) of the first color material represented by the general formula (I) to be contained in the ink, The amount (B) of the second color material represented by the general formula (II) and the amount (C) of the yellow dye as the third color material listed above are preferably as follows. That is, in consideration of the extremely vivid color tone and high image density obtained by combining these three kinds of color materials, and the effect of sufficient gas resistance in the formed image, the amount of the first color material The ratio of the mass (C) of the yellow dye that is the third color material is (A + B): C = 99: 1-80: It is preferable to prepare the ink so as to be in the range of 20. The content ratio of the first to third color materials in the ink is more preferably in the range of (A + B): C = 98: 2 to 85:15.

The ink according to the present invention can be used as an ink set combined with at least one color ink selected from yellow ink, magenta ink, and cyan ink. Examples of the color material contained in each color ink of yellow, magenta, and cyan that can be used at that time include, for example, water-soluble xanthene-based, triphenylmethane-based, anthraquinone-based, monoazo-based inks described in the color index. , Disazo dyes, trisazo dyes, tetraazo dyes and the like can be preferably used.

  The ink according to the present invention described above is particularly preferably used in an ink jet recording method in which droplets are discharged by the action of thermal energy to perform recording, but it can also be used as other ink jet recording methods and general writing tools. Needless to say.

[Recording device, ink cartridge, recording unit]
Next, a recording method and a recording apparatus suitable for performing recording using the ink according to the present invention will be described. First, there is an apparatus that applies thermal energy corresponding to a recording signal to ink in a recording head chamber having an ink storage portion in which these inks are stored, and generates ink droplets by the energy.

  1 to 3 show a configuration example of a recording head that is a main part of the recording head. The head 13 is a heat generating head 15 having a glass, ceramic, or plastic plate having a groove 14 through which ink passes and a heat generating resistor used for thermal recording (the head is shown in the figure, but is not limited thereto). It is obtained by adhering The heat generating head 15 has good heat dissipation such as a protective film 16 formed of silicon oxide or the like, aluminum electrodes 17-1 and 17-2, a heat generating resistor layer 18 formed of nichrome or the like, a livestock heat layer 19, and alumina. It consists of a substrate 20. The ink 21 is filled up to the discharge orifice (fine hole) 22, and a meniscus 23 is formed by the pressure P.

  When a pulsed electric signal is applied to the electrodes 17-1 and 17-2 of the head 13, the region (heater) indicated by n of the heating element substrate 15 is rapidly heated, and the ink in contact with the surface is heated. Bubbles are generated in the nozzle 21, and the meniscus 23 is discharged by the pressure. The ink 21 is discharged through the nozzle 14 of the head, becomes an ink droplet from the discharge orifice 22, and flies toward the recording material. FIG. 3 shows an external view of an example of a multi-head in which a large number of heads shown in FIG. 1 are arranged. This multi-head is made by adhering a glass plate 27 having multi-nozzles 26 and a heating head 28 similar to that described in FIG.

  FIG. 4 shows an example of an ink jet recording apparatus incorporating this head. In FIG. 4, 61 is a blade as a wiping member, one end of which is held by a blade holding member to become a fixed end and form a cantilever. The blade 61 is disposed at a position adjacent to the recording area by the recording head, and in the case of the example shown in FIG. 4, it is held in a form protruding in the moving path of the recording head. Reference numeral 62 denotes a cap, which is disposed at a home position adjacent to the blade 61 and moves in a direction perpendicular to the moving direction of the recording head so as to come into contact with the ejection surface and perform capping. Further, reference numeral 63 in FIG. 4 denotes an ink absorber provided adjacent to the blade 61 and, like the blade 61, is held in a form protruding in the moving path of the recording head. The blade 61, the cap 62, and the absorber 63 constitute a discharge recovery portion 64, and the blade 61 and the absorber 63 remove moisture, dust, dust, and the like from the ink discharge port surface.

  Reference numeral 65 denotes a recording head that has discharge energy generating means and performs recording by discharging ink onto a recording material facing the discharge port surface on which the discharge ports are arranged. Reference numeral 66 denotes a recording head 65 having the recording head 65 mounted thereon. It is a carriage for performing the movement. The carriage 66 is slidably engaged with the guide shaft 67, and a part of the carriage 66 is connected to a belt 69 driven by a motor 68 (not shown). Accordingly, the carriage 66 can move along the guide shaft 67, and the recording area by the recording head 65 and its adjacent area can be moved.

  Reference numeral 51 denotes a paper feed unit for inserting a recording material, and 52 denotes a paper feed roller driven by a motor (not shown). With these configurations, a recording material is fed to a position facing the ejection port surface of the recording head, and is discharged to a paper discharge unit provided with a paper discharge roller 53 as recording progresses.

  In the above configuration, when the recording head 65 returns to the home position due to the end of recording or the like, the cap 62 of the head recovery unit 64 is retracted from the moving path of the recording head 65, but the blade 61 protrudes into the moving path. As a result, the ejection port surface of the recording head 65 is wiped. When the cap 62 is in contact with the ejection surface of the recording head 65 to perform capping, the cap 62 moves so as to protrude into the moving path of the recording head.

  When the recording head 65 moves from the home position to the recording start position, the cap 62 and the blade 61 are at the same position as that at the time of wiping described above. As a result, even in this movement, the ejection port surface of the recording head 65 is wiped. The above-mentioned movement of the recording head to the home position is performed not only at the end of recording or at the time of recovery of ejection, but also to the home position adjacent to the recording area at a predetermined interval while the recording head moves the recording area for recording. In accordance with this movement, the wiping is performed.

  FIG. 5 is a cross-sectional view showing an example of an ink cartridge 45 that contains ink supplied to the head via an ink supply member, for example, a tube. Here, reference numeral 40 denotes an ink container, for example, an ink bag, in which supply ink is stored, and a rubber plug 42 is provided at the tip thereof. By inserting a needle (not shown) into the stopper 42, the ink in the ink bag 40 can be supplied to the head. An ink absorber 44 receives waste ink.

  The ink jet recording apparatus used in the present invention is not limited to the one in which the head and the ink cartridge as described above are separated, and an apparatus in which they are integrated as shown in FIG. 6 is also preferably used. In FIG. 6, reference numeral 70 denotes a recording unit, in which an ink storage portion that stores ink, for example, an ink absorber is stored, and the ink in the ink absorber has a plurality of orifices. 71 is ejected as ink droplets. Reference numeral 72 denotes an atmosphere communication port for communicating the inside of the recording unit with the atmosphere. The recording unit 70 is used in place of the recording head 65 shown in FIG. 4 and is detachable from the carriage 66.

  Next, other specific examples of the recording apparatus and the recording head that can be suitably used in the present invention will be described. FIG. 7 shows a main part of an example of a liquid discharge head as a discharge liquid discharge head that communicates bubbles with the atmosphere during discharge suitable for the present invention, and an ink jet printer as a liquid discharge apparatus using the liquid discharge head. It is a schematic perspective view shown. The ink jet printer shown in FIG. 7 has a conveying device 1030 for intermittently conveying a sheet 1028 as a recording material provided along the longitudinal direction in a casing 1008 in the direction indicated by the arrow P shown in FIG. A recording unit 1010 that is reciprocated along a guide shaft 1014 substantially parallel to a direction S substantially orthogonal to the conveyance direction P of the paper 1028 by the conveying device 1030, and a driving unit for reciprocating the recording unit 1010 And a moving drive unit 1006.

  The conveying device 1030 includes a pair of roller units 1022a and 1022b that are arranged to face each other substantially in parallel, a pair of roller units 1024a and 1024b, and a drive unit 1020 for driving each of these roller units. Yes. With this configuration, when the driving unit 1020 of the transport device 1030 is activated, the paper 1028 is sandwiched between the roller units 1022a and 1022b and the roller units 1024a and 1024b, and the direction of the arrow P shown in FIG. Are conveyed intermittently.

  Further, the movement drive unit 1006 is disposed substantially parallel to the belt 1016 wound around pulleys 1026a and 1026b disposed on the rotation shafts opposed to each other with a predetermined interval, and the roller units 1022a and 1022b, and the recording unit. The motor 1018 is configured to drive a belt 1016 coupled to a carriage member 1010a 1010 in the forward direction and the reverse direction.

  When the motor 1018 is activated and the belt 1016 rotates in the direction of arrow R in FIG. 7, the carriage member 1010a of the recording unit 1010 is moved by a predetermined amount of movement in the direction of arrow S in FIG. When the motor 1018 is activated and the belt 1016 rotates in the direction opposite to the arrow R direction in FIG. 7, the carriage member 1010a of the recording unit 1010 is predetermined in the direction opposite to the arrow S direction in FIG. Will be moved by the amount of movement. Further, a recovery unit 1026 for performing an ejection recovery process of the recording unit 1010 is opposed to the ink ejection port array of the recording unit 1010 at one end portion of the movement driving unit 1006 at a position serving as a home position of the carriage member 1010a. Is provided.

  In the recording unit 1010, inkjet cartridges (hereinafter simply referred to as cartridges) 1012Y, 1012M, 1012C, and 1012B are provided for each color, for example, for each of yellow, magenta, cyan, and black, a carriage member 1010a. Are detachably provided.

  FIG. 8 shows an example of an ink jet cartridge that can be mounted on the above-described ink jet recording apparatus. The cartridge 1012 in this example is of a serial type, and the main part is composed of an ink jet recording head 100 and a liquid tank 1001 for containing a liquid such as ink. The ink jet recording head 100 is formed with a large number of ejection ports 832 for ejecting liquid, and liquid such as ink is supplied from a liquid tank 1001 through a liquid supply passage (not shown) to a common liquid chamber ( (See FIG. 9). A cartridge 1012 shown in FIG. 8 is formed by integrally forming an ink jet recording head 100 and a liquid tank 1001 so that liquid can be supplied into the liquid tank 1001 as necessary. A structure in which a liquid tank 1001 is connected to 100 in a replaceable manner may be adopted.

  Hereinafter, a specific example of the liquid discharge head that can be mounted on the ink jet printer having the above-described configuration will be described in more detail. FIG. 9 is a schematic perspective view schematically showing the main part of the liquid discharge head showing the basic form of the present invention. Note that electrical wiring and the like for driving the electrothermal transducer are omitted.

  In the liquid discharge head of this example, for example, a substrate 934 made of glass, ceramics, plastic, metal or the like as shown in FIG. 9 is used. The material of such a substrate is not essential and functions as a part of the flow path component, and serves as a support for the material layer that forms the ink discharge energy generating element and the liquid flow path and discharge port described later. There is no particular limitation as long as it can function. Hereinafter, a case where a Si substrate (wafer) is used will be described. In addition to the formation method using a laser beam, the discharge port can be formed by, for example, an exposure apparatus such as MPA (Mirror Projector Aliner) using an orifice plate (discharge port plate) 935 described later as a photosensitive resin.

  In FIG. 9, reference numeral 934 denotes a substrate including an electrothermal conversion element (hereinafter also referred to as a heater) 931 and an ink supply port 933 including a long groove-like through-hole as a common liquid chamber portion. On both sides in the longitudinal direction of the 933, heaters 931, which are thermal energy generating means, are arranged in a staggered manner, one row at a time, for example, with an interval between electrothermal conversion elements (heaters) of 300 dpi. On the substrate 934, an ink flow path wall 936 for forming an ink flow path is provided. The ink flow path wall 936 is further provided with a discharge port plate 935 having a discharge port 832.

  Here, in FIG. 9, the ink flow path wall 936 and the ejection port plate 935 are shown as separate members. However, the ink flow path wall 936 is placed on the substrate 934 by a technique such as spin coating. By forming the same, the ink flow path wall 936 and the discharge port plate 935 can be simultaneously formed as the same member. In this example, the discharge port surface (upper surface) 935a side is further subjected to water repellent treatment.

  In this example, a serial type head that performs recording while scanning in the direction of arrow S in FIG. 7 described above is used, and recording is performed at, for example, 1,200 dpi. The drive frequency is 10 kHz, and one discharge port performs discharge at the shortest time interval of 100 μs.

  9 is a cross-sectional view of the discharge port portion 940 provided in the discharge port plate 935 including the discharge port 832 shown in FIG. 9, which is cut in a direction crossing the ink discharge direction (thickness direction of the orifice plate 935). The shape of is roughly a star. .

  In this example, the discharge port portion 940 has a shape in which, for example, a cross section cut in a direction crossing the thickness direction is a combination of two regular triangles each having a side of 27 μm rotated by 60 degrees.

  As described above, in the liquid discharge head of this example, when liquid is discharged in the volume reduction stage after the bubble has grown to the maximum volume, the discharge is performed by the plurality of grooves dispersed with respect to the center of the discharge port. The direction of the main droplet at the time can be stabilized. As a result, it is possible to provide a liquid ejection head with no landing deviation and high landing accuracy. In addition, high-speed and high-definition printing can be realized by being able to stably discharge even foaming variation at a high driving frequency.

  In particular, at the stage of reducing the volume of the bubbles, by discharging the liquid by making the bubbles communicate with the atmosphere for the first time, it is possible to prevent mist generated when discharging the droplets by communicating the bubbles with the atmosphere. It is also possible to suppress a state in which droplets adhere to the discharge port surface, which causes sudden discharge failure. In addition, as another embodiment of a recording head of a discharge method that can be suitably used in the present invention and communicates bubbles with the atmosphere at the time of discharge, for example, a so-called edge shooter type can be cited as described in Japanese Patent No. 2783647. It is done.

  The ink according to the present invention is used in an ink jet recording apparatus having a recording unit provided with a storage unit for independently storing inks constituting an ink set, an ink cartridge, and the like. In the above description, the ink jet recording apparatus has been described by taking as an example a recording apparatus that ejects ink droplets by applying thermal energy to ink, but in addition, a piezoelectric ink jet recording apparatus that uses piezoelectric elements. But it can be used as well.

  Next, the present invention will be described in more detail with reference to examples and comparative examples. Unless otherwise specified, each ink component means “part by mass”.

<Examples 1-4>
The following components were mixed, sufficiently stirred and dissolved, followed by pressure filtration with a 0.20 μm filter to prepare black inks of Examples 1 to 4, respectively.
(Ink composition of Example 1)
-2.0 parts of the exemplified compound 1 represented by the general formula (I)-2.0 parts of the exemplified compound 6 represented by the general formula (II)-C.I. I. Direct Yellow 132 0.1 part ・ Glycerin 5.0 part ・ Urea 5.0 part ・ Ethylene glycol 10.0 part ・ Acetylenol EH (manufactured by Kawaken Fine Chemicals Co., Ltd.) 0.5 part ・ Ethanol 5.0 part ・ Ion-exchanged water 70.4 parts

(Ink composition of Example 2)
2.5 parts of the exemplified compound 2 represented by the general formula (I) 1.5 parts of the exemplified compound 8 represented by the general formula (II) I. Direct Yellow 86 0.3 part ・ Glycerin 5.0 part ・ Urea 5.0 part ・ Ethylene glycol 10.0 part ・ Acetylenol EH (manufactured by Kawaken Fine Chemicals Co., Ltd.) 0.5 part ・ Ethanol 5.0 part ・ Ion-exchanged water 70.2 parts

(Ink composition of Example 3)
1.8 parts of the exemplified compound 3 represented by the general formula (I) 2.4 parts of the exemplified compound 9 represented by the general formula (II) I. Direct Yellow 86 0.5 part ・ Glycerin 5.0 part ・ Urea 5.0 part ・ Ethylene glycol 10.0 part ・ Acetylenol EH (manufactured by Kawaken Fine Chemicals Co., Ltd.) 0.5 part ・ Ethanol 5.0 part ・ Ion-exchanged water 69.8 parts

(Ink composition of Example 4)
-2.0 parts of the exemplified compound 5 represented by the general formula (I)-2.0 parts of the exemplified compound 7 represented by the general formula (II)-5.0 parts of glycerin-5.0 parts of urea-ethylene glycol 10 .0 parts, 0.5 parts of acetylenol EH (manufactured by Kawaken Fine Chemical Co., Ltd.), 5.0 parts of ethanol, 70.5 parts of ion-exchanged water

<Comparative Examples 1-4>
The following components were mixed, sufficiently stirred and dissolved, followed by pressure filtration through a 0.20 μm filter to prepare black inks of Comparative Examples 1 to 4, respectively.

(Ink composition of Comparative Example 1)
-4.2 parts of the exemplified compound 4 represented by the general formula (I)-5.0 parts of glycerin-5.0 parts of urea-10.0 parts of ethylene glycol-0.5 part of acetylenol EH (manufactured by Kawaken Fine Chemical Co., Ltd.)・ 5.0 parts of ethanol ・ 70.3 parts of ion-exchanged water

(Ink composition of Comparative Example 2)
-4.2 parts of the exemplified compound 6 represented by the general formula (II)-5.0 parts of glycerin-5.0 parts of urea-10.0 parts of ethylene glycol-0.5 part of acetylenol EH (manufactured by Kawaken Fine Chemical Co., Ltd.)・ 5.0 parts of ethanol ・ 70.3 parts of ion-exchanged water

(Ink composition of Comparative Example 3)
-4.0 parts of the said exemplary compound 6 shown by general formula (II)-C.I. I. Direct Yellow 86 0.4 part ・ Glycerin 5.0 part ・ Urea 5.0 part ・ Ethylene glycol 10.0 part ・ Acetylenol EH (manufactured by Kawaken Fine Chemicals Co., Ltd.) 0.5 part ・ Ethanol 5.0 part ・ Ion-exchanged water 70.1 parts

(Ink composition of Comparative Example 4)
・ C. I. Food Black 2 4.0 parts, glycerin 5.0 parts, urea 5.0 parts, ethylene glycol 10.0 parts, acetylenol EH (manufactured by Kawaken Fine Chemicals Co., Ltd.) 0.5 parts, ethanol 5.0 parts, ion-exchanged water 70.5 parts

<Evaluation of ink>
Each of the inks of Examples 1 to 4 and Comparative Examples 1 to 4 of the present invention obtained above has an on-demand type multi-recording head that ejects ink by applying thermal energy corresponding to the recording signal to the ink. Each was mounted on a color ink jet printer (BJ F850: manufactured by Canon Inc.) as an ink jet recording apparatus, and the following (1) and (2) were evaluated according to the following methods and standards. Table 1 summarizes the color materials of the inks of Examples 1 to 4 and Comparative Examples 1 to 4 and the evaluation results obtained using these inks.

(1) Black reproducibility (color development)
After filling the above-mentioned printer with a predetermined ink and printing a solid part on two types of recording materials, PPC paper (made by Canon) and glossy paper (PR-101; made by Canon) having a surface coat layer, 24 It was naturally dried for a period of time, and the color tone of the subsequent image was visually observed and evaluated according to the following criteria.
A: A clear black color tone.
B: A color slightly different from a clear black (redness, blueness, greenness, etc.) is felt.
C: There is a sense of incongruity as a black color tone.

(2) Gas resistance (ozone resistance)
The above-described printer was filled with a predetermined ink, and a solid portion similar to that used in evaluation (1) was printed on glossy paper (PR-101; manufactured by Canon). Thereafter, the printed matter was naturally dried for 24 hours, and the printed matter was put in an ozone fade meter under conditions of 40 ° C. in the tank, 55% relative humidity and 3 ppm in an ozone atmosphere for one hour. The color difference ΔE (CIE L ^* a ^* b ^* ) of the printed matter before and after the test was measured with Gretag Spectrolino (trade name: manufactured by Gretag), and the gas resistance was evaluated according to the following criteria using the obtained measured values. . Further, the degree of hue change of the solid part before and after the test was visually observed and evaluated according to the following criteria.

(2-1) ΔE
A: ΔE change amount is less than 15 B: ΔE change amount is 15 or more and less than 20 C: ΔE change amount is 20 or more

(2-2) Hue change A: Hue change is hardly felt in the image after the test.
B: The hue after the test is slightly changed.
C: The hue after the test is clearly changed (brown).

It is a longitudinal cross-sectional view of the head part of an inkjet recording device. It is a cross-sectional view of the head part of an inkjet recording device. It is an external appearance perspective view of the head part of an inkjet recording device. It is a perspective view which shows an example of an inkjet recording device. It is a longitudinal cross-sectional view of an ink cartridge. It is a perspective view of a recording unit. It is a schematic perspective view which shows the principal part of an example of the inkjet printer which can mount a liquid discharge head. It is a schematic perspective view showing an example of an ink jet cartridge provided with a liquid discharge head. It is a schematic perspective view which shows typically the principal part of an example of a liquid discharge head.

Explanation of symbols

13: head 14: ink groove 15: heating head 16: protective film 17-1, 17-2: aluminum electrode 18: heating resistor layer 19: heat storage layer 20: substrate 21: ink 22: ejection orifice (micropore)
23: meniscus 24: ink droplet 25: recording material 26: multi-nozzle 27: glass plate 28: heat generating head 40: ink bag 42: stopper 44: ink absorber 45: ink cartridge 51: paper supply unit 61: blade 62: Cap 63: Ink absorber 64: Ejection recovery unit 65: Recording head 66: Carriage 70: Recording unit 71: Head unit 72: Air communication port 100: Inkjet recording head 832: Ejection port 931: Electrothermal conversion element (heater, ink Discharge energy generating element)
933: Ink supply port (opening)
934: Substrate 935: Orifice plate (discharge port plate)
935a: discharge port surface 936: ink flow path wall 940: discharge port portion 1012: cartridge

Claims (10)

An ink comprising at least a color material represented by general formula (I) and a color material represented by general formula (II).

(In the general formula (I), R ₁ and R ₂ each independently represents a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, and at least _one of R ₁ and R ₂ is 1 An alkyl group having a hydroxyl group, R ₃ represents a hydrogen atom or a substituted or unsubstituted phenyl group, and X ₁ is a carboxyl group or a sulfonic acid group, or an alkali metal salt, ammonium salt, or organic group thereof. Represents any one of ammonium salts, m represents 1 or 2. M represents a counter ion of a sulfonic acid group, and represents any of alkali metal, ammonium and organic ammonium.)

(In the general formula (II), R ₄ and R ₅ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an alkanoylamino group having 2 to 4 carbon atoms, and alkoxy (1-4 carbon atoms) - alkoxy represents one of (1 to 4 carbon atoms) group, and, .R ₆ at least one of R ₄ and R ₅ is an alkoxy group having 1 to 4 carbon atoms, Represents a hydrogen atom or a substituted or unsubstituted phenyl group, benzoyl group or benzyl group, X ₂ represents a carboxyl group or a sulfonic acid group, or an alkali metal salt, ammonium salt or organic ammonium salt thereof; N represents 1 or 2. M is a counter ion of the sulfonic acid group, and represents any one of alkali metal, ammonium, and organic ammonium.)   The ink according to claim 1, wherein the mixing ratio of the color material represented by the general formula (I) and the color material represented by the general formula (II) is in a range of 8: 2 to 2: 8 by mass ratio. .   The ink according to claim 1, further comprising a yellow dye.   The ink according to claim 3, wherein the content of the yellow dye is 1 to 20% on a mass basis with respect to the total content of all color materials in the ink.   The yellow dye is C.I. I. Direct Yellow 86 or C.I. I. The ink according to claim 3, comprising at least one of Direct Yellow 132.   The ink according to claim 1, which is an ink used for inkjet recording.   7. An ink jet recording method comprising a step of ejecting ink from an orifice in response to a recording signal, wherein the ink is the ink according to claim 6.   7. A recording unit provided with an ink containing part for containing ink and a head part for discharging the ink, wherein the ink is the ink according to claim 6.   An ink cartridge provided with an ink containing portion for containing ink, wherein the ink is the ink according to any one of claims 1 to 6. . 7. An ink jet recording apparatus comprising a recording unit having an ink containing part containing ink and a head part for discharging the ink, wherein the ink is the ink according to claim 6. An ink jet recording apparatus.

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