JP4500579B2 - Inkjet recording method - Google Patents

Description

The present invention relates to an ink printing method and, more particularly, to an ink jet recording method having excellent printing mechanism can be formed with high quality printed images for any of the recording medium of plain paper and an ink jet recording special paper.

  Ink jet recording (hereinafter also referred to as ink printing) technology has an advantage that it does not matter what kind of recording medium is used for printing. From this point of view as well, printers using inkjet technology use various print media (recording media) such as plain paper, coated paper, transparency film for OHP, glossy paper, glossy film, and the like. There are many things that are considered possible. On the other hand, as ink jet printers and the like become widespread, there is also a circumstance that a higher level of print quality and print speed is desired. Specifically, for example, when printing a character such as a black character, reflection optical density (hereinafter also referred to as “OD”) and high-speed fixing equivalent to those of an electrophotographic system are required. This situation is not limited to black characters and the like, and the same applies to the printing of full-color images.

  In recent years, the use of a dedicated recording medium (dedicated medium) has been widely used to obtain a photographic-like recorded matter by ink printing, and a material with higher glossiness and color development is demanded. It has been.

  On the other hand, as one of the attempts to increase the OD conventionally performed, a configuration for printing using pigment ink has been proposed in order to improve character quality on plain paper. As another example, there is also known one that performs printing using two liquids of a dye ink and a treatment liquid that insolubilizes the dye ink.

  As an example of such a pigment ink used in ink printing, there is a disclosure of a pigment ink in which a pigment is dispersed in an aqueous medium using an AB or BAB type block polymer (for example, see Patent Document 1). There is also a disclosure of a pigment ink in which a pigment is dispersed in an aqueous medium using an ABC type triblock polymer (see, for example, Patent Document 2).

  Furthermore, pigment inks using self-dispersing pigments that do not use dispersants such as the block polymers listed above are also known. For example, a pigment ink in which a carbon black is dispersed in an aqueous medium by directly bonding a hydrophilic group to the surface of the carbon black is disclosed (for example, a patent document relating to an international patent application). 3 and 4).

  Further, at the same time as the above-described improvements related to ink, improvements have also been made on dedicated media, and by using the dedicated media, realization of photographic-like recording with higher gloss is being achieved.

  In order to achieve both printing on such a dedicated medium and printing on plain paper, recording is performed by switching between two types of pigment ink and dye ink corresponding to the recording paper to be printed. There is also a proposal for this method (for example, see Patent Document 5).

  In the technique of printing using two liquids of ink and processing liquid, when recording on plain paper, the processing liquid is recorded after printing ink mixed with pigment and dye, and a dedicated medium. There is also a proposal for a method of recording only ink mixed with pigment and dye in the case of recording (see, for example, Patent Document 6).

  The applicant has already proposed a pigment having two different properties, that is, an ink in which a self-dispersing pigment and a resin-dispersed pigment are mixed, and the ink applied to the recording medium by using such an ink. It spreads moderately in the lateral direction of the recording medium with respect to the droplets, and the penetration of the recording medium in the thickness direction is suppressed. As a result, the dot diameter has an appropriate spread, and the image density within the dots It is disclosed that a dot having an excellent outer shape that is high and uniform and that hardly exhibits feathering can be formed (see Patent Document 7).

JP-A-5-179183 JP 7-53841 A WO96 / 18695 pamphlet International Publication No. 96/18696 Pamphlet Japanese Patent Laid-Open No. 11-1647 JP 2000-190480 A JP 2000-239589 A

  However, as a result of further studies by the present inventors, the above-described ink shows good quality when recorded on plain paper, but when recorded on a dedicated medium that achieves glossiness, It has been found that the image has a problem that it is not very suitable for photographic-like recording because it has almost no glossiness.

Therefore, as described above, the object of the present invention is to develop a printing mechanism that can achieve both good printing quality and good recording on a dedicated medium that achieves a glossy feel when printed on plain paper. Another object of the present invention is to provide an ink jet recording method capable of realizing the formation of a high quality printed image on any recording medium of plain paper and ink jet recording dedicated paper.

The above object is achieved by the present invention described below. That is, the ink jet recording method as one embodiment of the present invention includes a first ink containing two first and second pigments dispersed in an aqueous medium as a coloring material, and a coloring material as the coloring material. and two kinds of inks of the second ink containing a dye in an aqueous medium, in an ink jet recording method for forming an image on a recording medium by using a treatment liquid, the first ink, the first pigment, A self-dispersing pigment in which at least one anionic group is bonded directly or via another atomic group to the surface of the pigment, or at least one cationic group is directly or otherwise bonded to the surface of the pigment; a pigment self-dispersible which is bonded via an atomic group, said second pigment is a pigment that is dispersed in the aqueous medium by a polymer dispersant, further to the first surface of the pigment Group attached Comprises at least one of the same polarity of the polymer dispersant or nonionic polymer dispersant, the second ink comprises an anionic dye, the treatment solution, the first pigment, the When the recording medium is plain paper, the second pigment contains a component that aggregates or insolubilizes at least one colorant of the anionic dye, and the first ink and the second ink When the processing liquid is applied after the first ink and the second ink are applied to the recording medium using the processing liquid, and the recording medium is glossy paper, only the second ink is used. Is applied to the recording medium .

  The ink jet recording apparatus according to the present invention can be applied to ink printing devices such as printers, copiers, and facsimiles that print characters, images, and the like on various recording media such as paper. According to such an ink jet recording apparatus, when printing on plain paper, it is possible to record with better printing quality, and at the same time, when recording on a dedicated medium, it is possible to form a glossy image. It is possible to provide a high-quality print image for both recording media, paper and inkjet recording paper.

  The ink jet recording apparatus of the present invention capable of obtaining the above-described effects was obtained in the course of research aimed at further improving the quality of ink jet recorded images. As described above, inks composed of a mixture of a self-dispersing pigment, a resin-dispersed pigment dispersed with a dispersing agent, and a polymer dispersing agent are required to improve the image quality of images recorded on plain paper. In the ink jet recording apparatus according to the present invention, the first ink is used as an ink used in the ink jet recording apparatus. In addition to the above, a second ink containing a dye is used, and more preferably, a treatment liquid containing a component that causes aggregation or insolubilization of the colorant is used, and the ink is applied to discharge the ink and the treatment liquid. In addition to the effects described above, the glossiness can be increased when recording on special paper that requires glossiness. Effect that provide an image which satisfies the level becomes possible. The following are particularly preferred specific embodiments.

  As a first embodiment of the ink jet recording apparatus according to the present invention, when the recording medium is plain paper, the processing liquid is recorded after the first ink is recorded on the recording medium, and the recording medium is a glossy layer and / or Examples of the recording medium having an ink receiving layer include an apparatus configured to record only the second ink. In such an apparatus, a mode in which printing is performed using both the first ink and the treatment liquid and a mode in which printing is performed using only the second ink can be selectively executed, so that various recording media can be used. On the other hand, a high-quality image can be obtained in any case.

  For example, when printing on a special print medium on which a coat layer is formed in order to obtain a glossy image, the mode using only the second ink of the above-described apparatus is selected, and only the dye is contained. An image is formed with the ink. As a result, high-speed fixing printing can be performed at a high OD without causing cracked image quality deterioration in the coat layer, and a glossy image can be obtained. On the other hand, when printing on plain paper, a mode in which the first ink and the processing liquid are used together is selected to form an image. As a result, it is possible to perform printing with a sharp OD and high OD without blur.

  As a second embodiment of the ink jet recording apparatus according to the present invention, when the recording medium is plain paper, the processing liquid is applied after recording the two inks of the first ink and the second ink on the recording medium. When recording and when the recording medium is a recording medium having a glossy layer and / or an ink receiving layer, an apparatus configured to record only the second ink may be used. In such an apparatus, it is possible to selectively execute a mode in which printing is performed using both the first ink and the second ink and a treatment liquid, and a mode in which printing is performed using only the second ink. As in the case of the first embodiment, it is possible to obtain high-quality images for various recording media. For example, when printing on a special print medium on which a coat layer is formed in order to obtain a glossy feeling, the mode using only the second ink is selected, while for the plain paper, the first ink and By selecting a mode in which the second ink and the treatment liquid are used together and performing printing, it is possible to perform printing with high print quality and high adhesion on both plain paper and special media. The apparatus according to the second embodiment has an advantage that a relatively good image can be formed even when the user sets an incorrect paper type.

Hereinafter, the first and second preferred embodiments of the present invention described above will be described in more detail to clarify the present invention.
(First Embodiment 1)
In the apparatus of this embodiment, as described above, it is possible to perform printing by switching the mode according to the type of print medium to be used. In other words, such an apparatus is configured such that the print mode is switched depending on whether the print medium to be used is plain paper or a special medium. Therefore, it is more preferable that the apparatus is provided with a paper type detection function that automatically detects the type of the recording medium and performs mode switching.

  In the plain paper mode, a first ink using a mixture of a self-dispersing pigment, a polymer-dispersed pigment, and a polymer dispersant that disperses the pigment in an aqueous medium, and these colors Printing is performed on the material using a treatment liquid that causes aggregation and / or insolubilization.

  In this case, it is preferable to use a first ink having a relatively low permeability and a treatment liquid used in combination with the first ink to have a higher permeability than the first ink. This makes it possible to form letters, images, etc. with sharp edges that do not bleed due to the reaction between the pigment and the treatment liquid, and it is possible to keep the color material near the surface layer of the print medium, thereby increasing the OD. You can also. In addition, if a treatment liquid having a high permeability is used, the addition of the treatment liquid promotes the penetration of a coloring material or the like into a print medium, thereby realizing fast ink fixing.

  On the other hand, in the special medium mode, printing is performed using only the second ink having only a dye as a color material, and in this case, no processing liquid is used.

  Specific examples of the first ink containing two types of pigments used in the present embodiment include a pigment ink having a configuration as described in Japanese Patent Application Laid-Open No. 2000-239589. That is, as an example of an ink that can be used in the present invention, an ink containing a first pigment and a second pigment as a coloring material in a dispersed state in an aqueous medium, the first pigment being at least one A self-dispersing pigment in which an anionic group is bonded directly or through another atomic group to the surface of the first pigment or at least one cationic group is directly or through another atomic group A self-dispersing pigment bonded to the surface of the first pigment, and the second pigment can be dispersed in the aqueous medium by a polymer dispersant or a nonionic polymer dispersant. The ink further includes an ink containing at least one of a polymer dispersant having the same polarity as the group bonded to the surface of the first pigment and a nonionic polymer dispersant.

Hereinafter, the ink will be sequentially described.
(First pigment)
Self-dispersing pigments are ink-jet recording technologies that maintain a stable dispersion state with respect to water, water-soluble organic solvents or mixed liquids without using a dispersant such as a water-soluble polymer compound. It refers to a pigment that does not cause agglomeration of pigments in the liquid, which hinders normal ink ejection from the orifice used.

(Anionic self-dispersing carbon black)
As such a pigment, for example, a pigment in which at least one anionic group is bonded to the pigment surface directly or through another atomic group is suitably used. Specific examples include at least one anionic group. It includes carbon black bonded to the surface directly or through other atomic groups.

Examples of the anionic group bonded to such carbon black include, for example, —COOM, —SO ₃ M, —PO ₃ HM, —PO ₃ M _{2 and the} like (wherein M is a hydrogen atom, Represents an alkali metal, ammonium, or organic ammonium).
Examples of the “M” alkali metal include lithium, sodium, potassium, and the like, and examples of the “M” organic ammonium include mono to trimethyl ammonium, mono to triethyl ammonium, and mono to trimethanol ammonium. Can be mentioned.
Among these anionic groups, —COOM and —SO ₃ M are particularly preferable because they have a great effect of stabilizing the dispersion state of carbon black.

  By the way, it is preferable to use the above-mentioned various anionic groups bonded to the surface of carbon black through other atomic groups. Examples of the other atomic group include a linear or unsubstituted alkylene group having 1 to 12 carbon atoms, a substituted or unsubstituted phenylene group, and a substituted or unsubstituted naphthylene group. Here, examples of the substituent which may be bonded to the phenylene group or naphthylene group include a linear or branched alkyl group having 1 to 6 carbon atoms.

Specific examples of the anionic group bonded to the surface of carbon black through another atomic group include, for example, —C ₂ H ₄ COOM, —PhSO ₃ M, —PhCOOM, etc. (where M is the same as defined above) Ph represents a phenyl group), but of course, it is not limited thereto.
Carbon black in which an anionic group is bonded to the surface directly or through another atomic group as described above can be produced, for example, by the following method.
That is, as a method for introducing —COONa into the carbon black surface, for example, a method of oxidizing a commercially available carbon black with sodium hypochlorite can be mentioned.

Further, for example, as a method of bonding —Ar—COONa group (where Ar represents an aryl group) to the surface of carbon black, a diazonium salt obtained by allowing nitrous acid to act on NH ₂ —Ar—COONa group is used. Although the method of making it couple | bond with the surface is mentioned, Of course, this invention is not necessarily limited to this.

(Cationic self-dispersing carbon black)
(Cationically charged carbon black)
Examples of the cationically charged carbon black include those in which at least one selected from the following quaternary ammonium groups is bonded to the surface of the carbon black.

を結合させる方法を例にとって説明すると、カーボンブラックを３−アミノ−Ｎ−エチルピリジウムブロマイドで処理する方法が挙げられる。この様にカーボンブラック表面への親水性基の導入によってアニオン性若しくはカチオン性に帯電させたカーボンブラックは、イオンの反発によって優れた水分散性を有するため、水性インク中に含有させた場合にも分散剤等を添加しなくても安定した分散状態を維持する。 In the above formula, R represents, for example, a linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted naphthyl group. Here, examples of the substituent for the phenyl group or naphthyl group include a linear or branched alkyl group having 1 to 6 carbon atoms. Examples of the substituent in the case where R is a phenyl group having a substituent or a naphthyl group having a substituent include a C1-C6 linear or branched alkyl group. Examples of a method for producing a self-dispersing carbon black having a hydrophilic group bonded thereto and charged cationically include, for example, an N-ethylpyridyl group having the structure shown below:

An example of the method of bonding the carbon atom is a method of treating carbon black with 3-amino-N-ethylpyridinium bromide. In this way, carbon black charged anionic or cationic by introducing a hydrophilic group to the surface of carbon black has excellent water dispersibility due to repulsion of ions, so even when it is contained in aqueous ink. A stable dispersion state is maintained without adding a dispersant or the like.

By the way, various hydrophilic groups as described above may be directly bonded to the surface of carbon black. Alternatively, another atomic group may be interposed between the carbon black surface and the hydrophilic group, and the hydrophilic group may be indirectly bonded to the carbon black surface. Here, specific examples of the other atomic groups include, for example, a linear or branched alkylene group having 1 to 12 carbon atoms, a substituted or unsubstituted phenylene group, and a substituted or unsubstituted naphthylene group. Here, as a substituent of a phenylene group and a naphthylene group, a C1-C6 linear or branched alkyl group is mentioned, for example. Specific examples of combinations of other atomic groups and hydrophilic groups include, for example, —C ₂ H ₄ —COOM, —Ph—SO ₃ M, —Ph—COOM, etc. (where M is defined as described above). , Ph represents a phenyl group).

  By the way, 80% or more of the self-dispersing pigment contained in the ink according to the present embodiment has a particle diameter of 0.05 to 0.3 μm, particularly 0.1 to 0.25 μm. Is preferred. Such an ink adjustment method is as described in detail in the embodiments described later.

(Second pigment)
Examples of the second pigment that can be used in the ink of the present embodiment include a pigment that can be dispersed in an ink dispersion medium, specifically, an aqueous medium by the action of a polymer dispersant. That is, a pigment that can be stably dispersed in an aqueous medium for the first time as a result of the polymer dispersant adsorbing on the surface of the pigment particles is preferably used. Examples of such pigments include, for example, black pigments such as carbon black pigments such as furnace black, lamp black, acetylene black, and channel black. As specific examples of such carbon black pigments, for example, the following can be used alone or in appropriate combination.

Raven 7000, Rayvan 5750, Rayvan 5250, Rayvan 5000 ULTRA, Rayvan 3500, Rayvan 2000, Rayvan 1500, Rayvan 1250, Rayvan 1200, Rayvan 1190ULTRA-II, Rayvan 1170, Rayvan 1255 (above Colombia), Black Pearls ( Black Pearls L, Regal 400R, Legal 330R, Legal 660R, Moguul L, Monarch 700, Monak 800, Monak 880, Monak 900, Monak 1000, Monak 1100, Monak 1300, Monak 1400, Vulcan XC-72R (manufactured by Cabot Corporation), color black (Color Black) FW1, Color Black FW2, Color Black FW2V, Color Black 18, Color Black FW200, Color Black S150, Color Black S160, Color Black S170, Printex 35, Printex U, Printex V, Printex 140U , Printex 140V, Special Black 6, Special Black 5, Special Black 4A, Special Black 4 (manufactured by Degussa), No. 25, no. 33, no. 40, no. 47, no. 52, no. 900, no. 2300, MCF-88, MA600, MA7, MA8, MA100 (manufactured by Mitsubishi Chemical Corporation).
Examples of other black pigments include magnetic fine particles such as magnetite and ferrite, and titanium black.

In addition to the black pigments described above, blue pigments, red pigments, and the like can also be used.
The amount of the color material combining the first and second pigments is 0.1 to 15% by mass, more preferably 1 to 10% by mass with respect to the total amount of the ink. The ratio of the first pigment to the second pigment is preferably 5/95 to 97/3, more preferably 10/90 to 95/5. More preferably, it is 1st pigment / 2nd pigment = 90 / 10-40 / 60. Furthermore, another preferable range is a range in which the first pigment is abundant. In the case of such a large amount of the first pigment, not only the dispersion stability as an ink, but also the stability including the ejection stability of the head, especially the reliability due to less ejection efficiency and less wetting of the ejection port surface is exhibited. Is done.

  Also, as the behavior of the ink on the paper, the ink spreads effectively on the surface of the paper with an ink having a small amount of the second pigment adsorbed by the polymer dispersant, so that a uniform thin film is formed on the surface by the polymer dispersant. It is presumed that the scratch resistance of the image is improved by the effect.

(Polymer dispersant)
The polymer dispersant for dispersing the second pigment in an aqueous medium has, for example, a function of adsorbing to the surface of the second pigment and stably dispersing the second pigment in the aqueous medium. Preferably used. Examples of such polymer dispersants include anionic polymer dispersants, cationic polymer dispersants, and nonionic polymer dispersants.

(Anionic polymer dispersant)
Examples thereof include a polymer of a monomer as a hydrophilic group and a monomer as a hydrophobic group and a salt thereof. Specific examples of the monomer as the hydrophilic group include, for example, styrene sulfonic acid, α, β-ethylenically unsaturated carboxylic acid, α, β-ethylenically unsaturated carboxylic acid derivative, acrylic acid, acrylic acid derivative, and methacrylic acid. Methacrylic acid derivatives, maleic acid, maleic acid derivatives, itaconic acid, itaconic acid derivatives, fumaric acid and fumaric acid derivatives.

  Specific examples of monomers as hydrophobic components include styrene, styrene derivatives, vinyl toluene, vinyl toluene derivatives, vinyl naphthalene, vinyl naphthalene derivatives, butadiene, butadiene derivatives, isoprene, isoprene derivatives, ethylene, ethylene derivatives, propylene. , Propylene derivatives, alkyl esters of acrylic acid, alkyl esters of methacrylic acid, and the like.

  Here, the salt specifically includes hydrogen, alkali metal, ammonium ion, organic ammonium ion, phosphonium ion, sulfonium ion, oxonium ion, stibonium ion, onium compounds such as stannonium, iodonium, etc. It is not limited to these. In addition, polyoxyethylene group, hydroxyl group, acrylamide, acrylamide derivative, dimethylaminoethyl methacrylate, ethoxyethyl methacrylate, butoxyethyl methacrylate, ethoxytriethylene methacrylate, methoxypolyethylene glycol methacrylate, vinylpyrrolidone, vinylpyridine Vinyl alcohol and alkyl ether may be added as appropriate.

(Cationic polymer dispersant)
As the cationic polymer dispersant, a tertiary amine monomer, a copolymer obtained by quaternizing these with a hydrophobic monomer, or the like is used. As the tertiary amine monomer, for example, N, N-dimethylaminoethyl methacrylate, N, N-dimethylacrylamide and the like are used. As the hydrophobic monomer, styrene, a styrene derivative, vinyl naphthalene, or the like is used. In the case of a tertiary amine, sulfuric acid, acetic acid, nitric acid and the like are used as a compound for forming a salt. Further, those quaternized with methyl chloride, dimethyl sulfate or the like can also be used.

(Nonionic polymer dispersant)
Examples of nonionic polymer dispersants include polyvinyl pyrrolidone, polypropylene glycol, vinyl pyrrolidone-vinyl acetate copolymer, and the like.
The first pigment, the second pigment, and the polymer dispersant described above can be appropriately selected in combination, and dispersed and dissolved in an aqueous medium to obtain the ink of this aspect. In the case of using a self-dispersing pigment in which at least one anionic group is bonded to the surface of the pigment directly or through another atomic group, an anionic polymer dispersant and Combining at least one selected from nonionic polymer dispersants is preferable from the viewpoint of ink stability, and for the same reason, at least one cationic group as the first pigment is directly or via another atomic group. In the case of using a self-dispersing pigment bonded to the surface of the pigment, a cationic polymer dispersant and a nonionic polymer dispersion are used as the polymer dispersant. It is preferably combined with at least one of said first pigment selected from.

(Aqueous medium)
As an aqueous medium serving as a dispersion medium for the first and second pigments, a water-soluble organic solvent is used.
For example, alkyl alcohols having 1 to 5 carbon atoms such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-pentanol; Amides such as dimethylformamide and dimethylacetamide; Ketones or ketoalcohols such as acetone and diacetone alcohol; Ethers such as tetrahydrofuran and dioxane; Diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene Oxyethylene or oxypropylene copolymers such as glycol and polypropylene glycol; ethylene glycol and propylene glycol Alkylene glycols in which the alkylene group contains 2 to 6 carbon atoms, such as trimethylene glycol, triethylene glycol, 1,2,6-hexanetriol; glycerin; ethylene glycol monomethyl (or ethyl) ether, diethylene glycol monomethyl (or Lower alkyl ethers such as ethyl) ether and triethylene glycol monomethyl (or ethyl) ether; lower dialkyl ethers of polyhydric alcohols such as triethylene glycol dimethyl (or ethyl) ether and tetraethylene glycol dimethyl (or ethyl) ether; Alkanolamines such as monoethanolamine, diethanolamine, triethanolamine; sulfolane, N-methyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2 Imidazolidinone. The water-soluble organic solvents as described above can be used alone or as a mixture.

(Penetration of ink into the recording medium)
The ink according to the present embodiment containing the various components described above pays attention to the permeability to the print medium, for example, when the Ka value is adjusted to less than 1 (ml · m ⁻² · msec ^−1/2 ). It is possible to obtain image dots with extremely uniform density. Hereinafter, the penetrability of the ink into the print medium will be described.

When the ink permeability is expressed by the ink amount V per 1 m ^2, the ink penetration amount V (unit: milliliter / m ² = μm) at the time t after the ink droplet is ejected is Bristow method as shown below. It is known that
V = Vr + Ka (t−tw) ^1/2
(However, t> tw)
Immediately after the ink droplets are dropped on the surface of the print medium, the ink droplets are mostly absorbed by the uneven portions of the surface (the roughness portion of the surface of the print medium) and hardly penetrate into the print medium. The time in the meantime is tw (wet time), and the amount of absorption in the concavo-convex portion is Vr. When the elapsed time after the ink droplet is dropped exceeds tw, the penetration amount V increases by an amount proportional to the half power of the excess time (t-tw). Ka is a proportional coefficient of this increase, and shows a value corresponding to the penetration rate.
The Ka value was measured using a liquid dynamic permeability test apparatus S (manufactured by Toyo Seiki Seisakusho) using the Bristow method. In this experiment, PB paper of Canon Inc., which is the present applicant, was used as a print medium (recording paper). This PB paper is a recording paper that can be used for both copying machines and LBPs using an electrophotographic system and printing using an inkjet recording system.
Similar results were obtained with PPC paper, which is an electrophotographic paper of Canon Inc.

  The Ka value is determined by the type of surfactant, the amount added, and the like. For example, ethylene oxide-2,4,7,9-tetramethyl-5-decyne-4,7-diol (ethylene oxide-2,4,7,9-tetramethyl-5-decyne-4,7-diol) By adding a nonionic surfactant called “Acetylenol” (manufactured by Kawaken Fine Chemical Co., Ltd.), the permeability is increased.

  In addition, in the case of an ink in which acetylenol is not mixed (content ratio is 0% by mass), the permeability is low, and the ink has properties as an overlay ink specified later. Further, when acetylenol is mixed at a content of 1% by mass, it has a property of penetrating into the recording paper in a short time, and has a property as a highly penetrating ink specified later. An ink in which acetylenol is mixed at a content ratio of 0.35% by mass has a property as a semi-permeable ink intermediate between the two.

  Table 1 above shows the Ka value, the acetylenol content (% by mass), and the surface tension (dyne / cm) for each of “superposition ink”, “semi-permeable ink”, and “highly permeable ink”. Yes. The permeability of each ink to the recording paper as a print medium increases as the Ka value increases. That is, the smaller the surface tension, the higher.

  The Ka values in Table 1 were measured using the liquid dynamic permeability test apparatus S (manufactured by Toyo Seiki Seisakusho) using the Bristow method as described above. In the experiment, the aforementioned PB paper from Canon Inc. was used as the recording paper. Similar results were obtained for the above-mentioned PPC paper from Canon Inc.

Here, the ink of the system defined as “highly penetrating ink” has an acetylenol content ratio of 0.7% by mass or more, and is in a range in which good results regarding penetrability are obtained. As a standard of permeability to be carried on the ink of the present embodiment, it is preferable to set the Ka value of “superposition-based ink”, that is, less than 1.0 (ml · m ⁻² · msec ^−1/2 ). Is preferably 0.4 (ml · m ⁻² · msec ^−1/2 ) or less.

  Further, the second ink using the anionic dye used in the present embodiment is not particularly limited, and examples thereof include a dye ink having a configuration as described in JP-A-06-088048. It is done.

  In addition, the treatment liquid containing a component that causes aggregation or insolubilization with respect to the color material used in the present embodiment may vary depending on the chemical structure of the color material used, for example, a cationic polymer or a surfactant. The thing containing components, such as these, is mentioned.

  The printing result in the plain paper mode using the first ink and the processing liquid is described in, for example, Japanese Patent Application Laid-Open No. 2000-239589. In this case, the dot diameter has an appropriate spread, In addition, the dot has an excellent image density in which the image density in the dot is high and uniform, and the feathering is hardly observed, so that characters of good quality can be obtained. On the other hand, the printing result in the special medium mode using only the second ink having the dye as the color material is also released from Canon Inc., for example, by the BJ printer PIXUS 950i released from Canon Inc. Similar to printing on the existing Pro Photo Paper (PR-101), the gloss and image quality are also good.

  Of course, the ink used in the apparatus of the present embodiment is not limited to the types (colors) of the dyes and pigments. However, as a preferred form, the first and second inks of the present embodiment are used for black ink. Is used. This is because an improvement in OD can be desired in printing characters such as letters.

(Second Embodiment)
In the apparatus of the present embodiment, as described above, the print mode is switched according to whether the print medium to be used is plain paper or special medium. In the plain paper mode, a self-dispersing pigment, a polymer-dispersed pigment, a first ink containing a polymer dispersant that disperses the pigment, and a second material that uses only a dye as a coloring material. Printing is performed using a treatment liquid that causes aggregation and insolubilization of the ink and these color materials.

  In this case, the ink has a relatively low permeability, and a treatment liquid having a higher permeability than the ink is used. As a result, characters, images, and the like with sharp edges and sharp edges can be formed by the reaction of the pigments and dyes with the treatment liquid, and can be kept near the surface layer of the color material print medium, and OD can be increased. . In this case, since a highly permeable liquid is used as the processing liquid, the penetration of the color material into the print medium can be promoted to achieve fast fixing.

  On the other hand, in the special medium mode, printing is performed without using the processing liquid by using only the second ink having only the dye as the color material. The configurations of the first ink and the second ink used in the present embodiment are the same as those in the first embodiment described above.

  The printing result in the plain paper mode in this embodiment is the same as that described in, for example, Japanese Patent Application Laid-Open No. 2001-10200 described in the first embodiment. That is, according to experiments conducted by the present inventors, when the proportion of the dye is small compared to the pigment, the behavior of the printing quality is almost equal to that of the mixed ink of the self-dispersing pigment and the polymer dispersing pigment. This is because the results are obtained. Therefore, in the printing in the plain paper mode in the present embodiment, control is performed so that the amount of the first ink and the second ink applied is, for example, 9: 1 to 5: 5. It is preferable.

  The print result in the special medium mode according to the present embodiment is, for example, a BJ printer PIXUS 950i available from Canon Inc., and Pro Photo Paper (PR-101) also available from Canon Inc. Similar to the printing on the paper, the glossiness and the image quality are also good.

  This embodiment is particularly effective in the following cases. If the paper type cannot be detected on the main unit due to cost reduction, etc., the user may set the wrong paper type. There is a possibility that recording is performed, or recording is performed on plain paper in the special medium mode. In other words, when a print mode is selected by a printer driver or the like, there are cases where there are a high-speed mode and a high-quality mode as upper options, and plain paper or special media can be selected as lower options. is there. In this case, the default paper in the high-speed mode may be plain paper, and the default paper in the high-quality mode may be a special medium.In addition, a novice user may not be aware of the lower options, The type may not be recognized.

  As described above, when the user does not select paper or makes a mistake, it is often expected. On the other hand, in order to give the user satisfaction with the printer, it is desirable that high-quality recording can be performed at any setting.

  On the other hand, according to the study by the present inventors, in glossy paper, it is better to print with ink containing a dye than with a pigment alone, so in an inkjet recording apparatus having both two printing modes. Assuming that the printing mode is misidentified, it has been found that it is preferable to record the pigment ink and the dye ink together, not the recording using only the pigment ink, even when the paper setting is plain paper.

  Therefore, in the present embodiment, in the plain paper medium mode, recording is performed using a first ink in which two kinds of pigments are mixed and a second ink that is a dye ink. As a result, even if the mode is not properly selected and recorded on glossy paper in the plain paper medium mode, not only the mixed ink of the self-dispersible pigment and the polymer dispersed pigment, Since dye ink is also recorded, relatively good print quality can be obtained.

  In the first and second embodiments described above, the processing liquid is not used in the special medium mode. However, the processing liquid used in the present invention is a print on which a coat layer such as glossy paper is formed. There is no particular problem even if it is used as a medium. However, since the coat layer is inherently good in wettability with respect to the dye ink, it exhibits a relatively high fixability when a dye is included as a coloring material of the ink, and the processing liquid Since the effect of reducing the consumption can be obtained, in the embodiment of the present invention described above, the processing liquid is not used in the special medium mode.

  The inkjet recording apparatus of the present invention further includes a recovery device for recovering the ink ejection state of the head that ejects ink, and the first ink recovery device and the second ink recovery device have different configurations. It is preferable. For example, the first ink recovery device has a simpler configuration with fewer parts than the second ink recovery device.

  The ink jet recording apparatus of the present invention further includes means for performing a recovery operation for recovering the ink discharge state of the head for discharging ink, and recovers the discharge state of the first ink and the second ink. It is preferable that the recovery operation is different. For example, the first recovery operation has a shorter operation time than the second recovery operation and is a simpler operation.

  The ink jet recording apparatus of the present invention further recovers the first recovery frequency for recovering the ink discharge state of the head for discharging the first ink and the ink discharge state of the head for discharging the second ink. It is preferable that the second recovery frequency is different. For example, a configuration in which the first recovery frequency is configured to be smaller than the second recovery frequency can be cited.

  The ink jet recording apparatus of the present invention records the second ink following the first ink on the recording medium, and records the second ink following the first ink on the recording medium. Further, it is preferable that the processing liquid is further recorded. Alternatively, the processing liquid may be recorded on the recording medium following the first ink, and then the second ink may be recorded. In the above-described embodiment, the recording order of the first ink and the second ink may be reversed.

Hereinafter, reference examples and examples of the above-described embodiment will be described in more detail with reference to the drawings.
( Reference Example 1)
FIG. 1 is a schematic diagram showing a schematic configuration of a full-line type printing apparatus according to this reference example, and shows a configuration corresponding to the first embodiment described above. In this printing apparatus, ink or processing liquid is ejected from a plurality of full-line type print heads arranged at predetermined positions along the conveyance direction (direction of arrow A in the figure) of the recording medium 103 as a print medium. An ink jet printing method in which printing is performed is adopted. Then, operations such as ejection are performed under the control of a control circuit (not shown).

  In the illustrated apparatus, each of 101Bk1, 101Bk2, 101S, 101C, 101M, and 101Y constituting each print head of the head group 101g is conveyed in the width direction of the recording paper 103 (FIG. 1). About 7200 ink ejection openings are arranged in a direction perpendicular to the paper surface), and printing can be performed on recording paper of maximum A3 size.

  After the recording paper 103 is conveyed in the A direction by the rotation of a pair of registration rollers 114 driven by a conveyance motor (not shown), the recording paper 103 is guided by a pair of guide plates 115 and the leading edge thereof is registered. It is conveyed by the conveyor belt 111. The conveyor belt 111 as an endless belt is held by two rollers 112 and 113, and the vertical displacement of the upper portion thereof is regulated by the platen 104. The recording sheet 103 is transported by rotating the roller 113. Note that the recording paper 103 is attracted to the transport belt 111 by electrostatic attraction. The roller 113 is rotationally driven in a direction in which the recording paper 103 is conveyed in the direction of arrow A by a drive source such as a motor (not shown). Then, the recording paper 103 on which recording is performed by the recording head group 101 g while being transported on the transport belt 111 is discharged onto the stocker 116.

  Each of the print heads constituting the recording head group 101g of this example generates bubbles in the liquid using thermal energy, and discharges the liquid by the pressure of the bubbles. In addition, the processing liquid head 101S for discharging the processing liquid described in the above embodiment, and black (which is a first ink using a mixture of a self-dispersing pigment and a polymer-dispersed pigment as a coloring material) Bk) a head 101Bk1 that discharges ink, and a head 101Bk2 that discharges black (Bk) ink, which is a second ink using only a dye as a color material, and further contains color ink Each head (cyan head 101C, magenta head 101M, yellow head 101Y) is arranged along the conveyance direction A of the recording paper 103 as shown in the figure. Then, black characters and color images are printed by ejecting each color ink and processing liquid in an appropriate combination according to the characteristics of the recording paper by each print head.

The composition of the treatment liquid and each ink used in this reference example is as follows. In addition, the ratio of each component is shown by the mass part. The treatment liquid and the ink liquid were each prepared to be 100 parts in total.

[Treatment solution]
-Glycerol 7 parts-Diethylene glycol 5 parts-Acetylenol EH (manufactured by Kawaken Fine Chemical Co., Ltd.) 2.0 parts-Polyallylamine (molecular weight: 1,500 or less, average about 1,000) 4 parts-Acetic acid 4 parts-Benzalkonium chloride 0.5 part, 3 parts of triethylene glycol monobutyl ether, remaining part of water

[Yellow (Y) ink]
・ C. I. Direct yellow 86 3 parts ・ Glycerin 5 parts ・ Diethylene glycol 5 parts ・ Acetylenol EH (manufactured by Kawaken Fine Chemicals) 1 part ・ Water balance

[Magenta (M) ink]
・ C. I. Acid Red 289 3 parts ・ Glycerin 5 parts ・ Diethylene glycol 5 parts ・ Acetylenol EH (manufactured by Kawaken Fine Chemicals) 1 part ・ Water balance

[Cyan (C) ink]
・ C. I. Direct Blue 199 3 parts ・ Glycerin 5 parts ・ Diethylene glycol 5 parts ・ Acetylenol EH (manufactured by Kawaken Fine Chemicals) 1 part ・ Water balance

[Black (Bk) ink 1]
・ Pigment dispersion 1 25 parts ・ Pigment dispersion 2 25 parts ・ Glycerin 6 parts ・ Triethylene glycol 5 parts ・ Acetylenol EH (manufactured by Kawaken Fine Chemicals) 0.1 part ・ Water balance

The pigment dispersion 1 used above is prepared as follows. First, 300 g of acidic carbon black (trade name: MA-77 (pH 3.0, manufactured by Mitsubishi Kasei)) was mixed well with 1,000 ml of water, and then 450 g of sodium hypochlorite (effective chlorine concentration 12%). Was added dropwise and stirred at 100 to 105 ° C. for 10 hours. The obtained slurry was Toyo Filter Paper No. 2 (advantis) and the pigment particles were thoroughly washed with water. The obtained pigment wet cake was re-dispersed in 3,000 ml of water, and desalted with a reverse osmosis membrane to a conductivity of 0.2 μs. Further, this pigment dispersion (pH = 8 to 10) was concentrated to a pigment concentration of 10% by mass. By the above method, the surface of the carbon black particles, hydrophilic -COO ^- self-dispersion carbon black which groups are charged anionic consisting coupled directly to obtain a pigment dispersion 1 dispersed.

  The pigment dispersion 2 used above was prepared as follows. As a dispersant, 14 parts of a styrene-acrylic acid-ethyl acrylate copolymer (acid value 180, weight average molecular weight 12,000), 4 parts of monoethanolamine and 72 parts of water are mixed, and the mixture is heated to 70 ° C. with a water bath. Warm to dissolve resin completely. At this time, if the concentration of the resin to be dissolved is low, the resin may not be completely dissolved. Therefore, when the resin is dissolved, a high concentration solution may be prepared in advance and diluted to prepare a desired resin solution. To this solution, 10 parts of carbon black (trade name: MCF-88, pH 8.0, manufactured by Mitsubishi Chemical), which can be dispersed in an aqueous medium for the first time by the action of a dispersant, was added and premixed for 30 minutes. Subsequently, the dispersion process was performed on condition of the following, and the pigment dispersion liquid 2 in which carbon black (MCF-88) was disperse | distributed to the aqueous medium with the polymer dispersing agent obtained above was obtained.

・ Disperser: Side grinder (Igarashi Machine)
・ Crushing media: 1 mm diameter of zirconia beads ・ Filling rate of grinding media: 50% (volume)
・ Crushing time: 3 hours ・ Centrifuge separation (12,000 RPM, 20 minutes)
The Ka value of Bk ink 1 prepared as described above was 0.40 (ml · m ⁻² · msec ^−1/2 ).

[Black (Bk) Ink 2]
・ Food black 2 5 parts ・ Glycerin 6 parts ・ Triethylene glycol 5 parts ・ Acetylenol EH (manufactured by Kawaken Fine Chemical Co., Ltd.) 0.1 part ・ Water balance

In the apparatus of this reference example, each of the inks prepared above was used, and each of the print heads that ejected these inks had ink ejection openings arranged at a density of 600 dpi. Then, printing was performed at a dot density of 600 dpi in the recording paper conveyance direction. As a result, the dot density of the image or the like printed in this reference example is 600 dpi in both the roller direction and the column direction.

The ejection frequency of each head is 4 kHz, and therefore the recording paper transport speed is about 170 mm / sec. The discharge amount of each print head is 30 pl per discharge for the head 101Bk and 15 pl per discharge for the other heads. Incidentally, as the self-dispersing pigment in the black ink 1 used in this reference example, 80% of the self-dispersing pigment is preferably in the range of 0.05 μm to 0.3 μm, more preferably 0.1 μm to 0.00. It is in the range of 25 μm. In this reference example, a 0.1 μm one was used.

In this reference example, in the plain paper mode, the apparatus configured as described above uses, as the black ink, an ink 1 in which a self-dispersing pigment and a polymer-dispersed pigment are mixed. The operation is controlled so that a highly permeable treatment liquid is applied. As a result, it was confirmed that printing on plain paper (manufactured by Canon Inc., PB paper) in this plain paper mode achieves both high image quality and high-speed fixing. The obtained image was a high OD image with sharp edges of the image without blur.

  On the other hand, in the special medium mode, the operation is controlled so that only the ink 2 containing only the dye is applied without using the ink 1 as the black ink. As a result, printing on glossy paper (manufactured by Canon Inc., Pro-Photo Paper PR-101) in the special medium mode enables high-quality images with glossiness to be printed at high speed by one-pass printing or the like. It was. The obtained image was a high OD image with excellent adhesion without causing cracked image quality deterioration in the coating layer.

(Example 2)
This example describes the full-line type printing apparatus according to the second embodiment described above, and the configuration of the ink used and the basic configuration of the apparatus are the same as those in Reference Example 1. .

In the case of the present embodiment, in the plain paper mode, black ink is used with ink 1 in which a self-dispersing pigment and a polymer-dispersed pigment are mixed and ink 2 with only a dye. The operation is controlled so that a highly permeable treatment liquid is applied. At this time, the application ratio of ink 1 and ink 2 was set to 7: 3. As a result, it was confirmed that both high image quality and high-speed fixing can be achieved by printing on plain paper (PB paper, manufactured by Canon Inc.) in the plain paper mode. The image quality was comparable to that in Reference Example 1. On the other hand, in the special medium mode, the operation is controlled so that only the dye-only ink 2 is applied as the black ink. As a result, printing on glossy paper (manufactured by Canon Inc., Pro-Photo Paper PR-101) in the special medium mode enables high-quality images with glossiness to be printed at high speed by one-pass printing or the like. It was. Further, when the glossy paper was printed in the above-described plain paper mode, a glossy and high-quality image was obtained although the glossiness was slightly inferior to the image printed in the special medium mode.

( Reference Example 3)
FIG. 2 is a diagram for explaining a schematic configuration of a head recovery mechanism provided in the full line type printing apparatus according to the present reference example. The basic part of the printing apparatus according to the present embodiment is similar to that shown in FIG. 1 described in the previous Reference Example 1, the description of this part is omitted.

The apparatus according to this reference example is provided with a head recovery mechanism as recovery means for cleaning the surface of the head that has been soiled by printing or the like. FIG. 2 is a schematic view focusing on the correlation between the head recovery mechanism 120 and the head. FIG. 2A is a schematic diagram of a head recovery mechanism for the head 101Bk2 for ejecting the ink 2 using a dye as a coloring material. The head recovery mechanism in this case has two blades, and after the head is roughly cleaned with the first blade, the ejection portion of the head is cleaned more cleanly using the second blade. In the color head (cyan head, magenta head, yellow head), the recovery mechanism has the same configuration as that for the ink 2.

In the examination process of the present inventors, the ink 1 that is a mixed ink of a self-dispersing pigment and a polymer-dispersed pigment is less likely to have stains after printing on the head surface than other inks that are dye inks. Has been found. If this fact is utilized, it can be said that even if the recovery mechanism of the Bk1 head is simplified, the operation is reduced, or the frequency is reduced, the printing is not affected. Therefore, in this reference example, as shown in FIG. 2B, the blade is reduced by one sheet as compared with other inks. Using the apparatus of this reference example configured as described above, the ejection of ink and processing liquid was controlled in the same manner as in the case of reference example 1. As a result, as in the case of Example 1, printing on plain paper on plain paper mode, and the image of even better quality at any printing on glossy paper with a special medium mode is obtained, Reference Compared to Example 1, it was confirmed that the printing durability was improved.

1 is a schematic diagram illustrating a schematic configuration of a recording apparatus according to an embodiment of the present invention. FIG. 2 is a schematic diagram illustrating a head recovery mechanism of a recording apparatus according to an embodiment of the invention.

Explanation of symbols

101g: head group 101Bk1: black head 1
101Bk2: Blackhead 2
101S: treatment liquid head 101C: cyan head 101M: magenta head 101Y: yellow head 103: recording medium 104: platen 111: endless transport belt 112, 113: transport roller 114: registration roller 115: guide plate 116: stocker 120: head recovery Mechanism 121: Blade

Claims (1)

Two types of inks: a first ink that contains the first and second pigments as a coloring material in a dispersed state in an aqueous medium; and a second ink that contains a dye as a coloring material in the aqueous medium ; In the inkjet recording method of forming an image on a recording medium using a treatment liquid ,
The first ink, the first pigment is self-dispersing pigment at least one anionic group on the surface of the pigment is bonded directly or through another atom group, or a pigment of a pigment self-dispersible to at least one cationic group bonded directly or through another atomic group to the surface, said second pigment is dispersed in the aqueous medium by a polymer dispersant A pigment, and further comprises at least one of a polymer dispersant having the same polarity as the group bonded to the surface of the first pigment or a nonionic polymer dispersant, and the second ink comprises: Comprising an anionic dye,
The treatment liquid comprises a component that aggregates or insolubilizes at least one colorant of the first pigment, the second pigment, and the anionic dye,
When the recording medium is plain paper, the first ink, the second ink, and the processing liquid are used to apply the first ink and the second ink to the recording medium and then perform the processing. Apply liquid,
An ink jet recording method comprising applying only the second ink to the recording medium when the recording medium is glossy paper .

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