JPH10140064A - Ink set for ink jet printing, and ink jet printing method and printing instrument using the ink set - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ink set, whose black ink gives a black ink image having excellent printing quality, water resistance and light stability, has excellent storage stability, wettability of the face of a printing head, ejection stability in intermittent ejection, etc., and is free from bleeding against another color ink. SOLUTION: This ink set is used for recording color image by an ink jet method on a material to be printed using two or more inks consisting of a black ink and color inks. The black ink is composed of an auto-dispersion type carbon black, in which at least one kind of hydrophilic group is bound on its surface directly or via another atomic group, as a coloring material. At the same time, the polarity of the coloring material in at least one color ink and the polarity of the coloring material of the black ink is opposite to each other. Ink jet printing method and an ink jet instrument using the ink set are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color ink jet recording ink set which is used when a color image is recorded on a recording material by using a plurality of color inks including black ink and combining these inks. Regarding the ink jet recording method and the ink jet equipment, in particular, an ink set having a sufficient image density on plain paper, obtaining a clear and high-quality image, and further having excellent water resistance and light resistance of a printed matter. The present invention relates to an ink jet recording method and an ink jet device using the same.

[0002]

2. Description of the Related Art Conventionally, in ink-jet recording, especially on plain paper, print density, print quality,
Black ink using a pigment for forming a black image having excellent fastness such as water resistance and light fastness, or blurring at the boundary between an image printed with black ink and an image printed with color ink ( An ink set which does not cause bleeding, and an ink jet recording method and apparatus using the same have been reported. For example,
JP-A-3-210373 discloses an ink using an acidic carbon black and an alkali-soluble polymer. Further, JP-A-3-134073 describes an ink-jet ink in which a dispersion having excellent storage stability and excellent dischargeability in a bubble jet recording apparatus can be easily obtained. JP-A-6-57192 discloses that black ink has at least one kind of anionic dye and bleeding containing at least one kind of cationic dye and a polyvalent precipitant in a yellow ink can be prevented. An ink set for inkjet is described. or,
JP-A-7-145336 discloses that an anionic ink and a cationic ink are used, and a polymer having the ionic property of the ink is contained in at least one of the inks. An ink set that can reduce bleed by contacting an anionic ink and a cationic ink during color printing is described.

[0003]

However, in the case of an ink using an acidic carbon black and an alkali-soluble polymer as described in Japanese Patent Application Laid-Open No. 3-210373, the carbon black is formed by the alkali-soluble polymer. Is dispersed, but this dispersion has many restrictions in securing the storage stability. Further, Japanese Unexamined Patent Application Publication No. 3-134
The ink described in Japanese Patent No. 073 is easy to obtain a dispersion excellent in storage stability and dischargeability in a bubble jet recording apparatus, but tends to have insufficient print density. An ink-jet ink set as described in JP-A-6-57192, in which the color material of the black ink contains at least one anionic dye and the yellow ink contains at least one cationic dye and a polyvalent precipitant. In the case of bleeding, although the bleeding is considerably suppressed, it is difficult to fully satisfy the printing density, printing quality, and image fastness of the black ink, and the coloring property of the yellow ink and, in some cases, the safety. Problems also arise.

Further, in the case of reducing bleed by bringing an anionic ink and a cationic ink into contact with each other in the presence of a polymer during multicolor printing as described in JP-A-7-145336. In some cases, depending on the type of the polymer to be contained, the reliability of the ink is adversely affected. In particular, during the printing, after the ink is ejected from a certain nozzle, if the ink is not ejected from the nozzle for a certain time (for example, about 1 minute), the next first ink is ejected from the nozzle. In such a case, stable ejection cannot be performed, and there may be a problem that printing is disturbed. Such a state is referred to as “poorness in singularity”, and the stability of intermittent ejection is hereinafter referred to as singularity.

Accordingly, an object of the present invention is to provide a black ink image which is obtained particularly when used as an ink-jet ink, has a high print density, good print quality, and satisfies perfect water fastness and perfect light fastness. In addition, the black ink is excellent in storage stability, wettability to the face surface of the head portion, clogging, uniformity, printing durability, and
An object of the present invention is to provide an ink-jet ink set in which the black ink does not cause bleeding with other color inks, an ink-jet recording method and equipment using the ink set.

[0006]

The above objects are achieved by the present invention described below. That is, the present invention provides an ink jet recording ink set for recording a color image on a recording material using two or more inks including at least a black ink and a color ink, wherein the black ink is used as a coloring material. On the surface of carbon black, a self-dispersible carbon black in which at least one hydrophilic group is bonded directly or via another atomic group, and
An ink jet recording ink set, wherein the polarity of the color material in at least one color ink is opposite to the color material in the black ink, an ink cartridge containing the ink set, and a recording unit.
An ink jet recording method and equipment using the same.

As described above, as a black ink used for ink jet recording, it is advantageous to use a pigment ink rather than a dye ink in order to ensure high image density and complete image fastness. However, in the case of a pigment ink, some dispersant is added to disperse the pigment in the ink. Therefore, when the ink is used for ink jet recording, harmful effects due to including the dispersant are likely to occur. For example, when a polymer type dispersant is used, there have been problems that the face surface of the head portion is easily wetted, clogging occurs, and storage stability is poor. Further, when a surfactant-type dispersant is used, there are problems that the print density is low and that the face surface of the head portion is easily wetted. On the other hand, in the case of the specific carbon black to be contained as a pigment in the black ink used in the present invention, since the carbon black itself is self-dispersed without containing a dispersant, the above-described dispersant is used. Does not cause any adverse effect.
That is, in a self-dispersion type carbon black in which at least one kind of hydrophilic group is bonded directly or via another atomic group to the surface of carbon black, the function of the hydrophilic group makes the carbon black itself an aqueous medium such as water. Therefore, a dispersing agent for dispersing the pigment is not particularly required because a stable dispersion state can be maintained.

Further, the polarity of the color material in the ink of another color is
The inventors have found that bleeding is effectively prevented when the polarity is opposite to that of the self-dispersion type carbon black in the black ink, thereby completing the present invention. That is, when inks having color materials of opposite polarities are used, bleeding between inks of different colors can be effectively prevented. However, in particular, when bleeding occurs between black ink and color ink, the quality is low. Therefore, in the present invention, a color ink containing a color material having a polarity opposite to that of the black ink is used. Alternatively, bleeding can be effectively prevented even when a color ink containing a compound having a polarity opposite to that of the black ink is used. Instead, a color ink having a compound of the opposite polarity is used.

For example, at present, an anionic coloring material is often used for color inks in terms of light resistance, safety, and the like, and an anionic coloring material for color inks has excellent water resistance. However, in this case, it is preferable to use a cationic self-dispersion type carbon black to suppress the bleeding of the black ink and the color ink. On the other hand, when anionic carbon black is used, it is difficult to suppress the occurrence of bleed between the anionic color ink and the coloring material for color ink. Bleeding must be prevented, such as by adding some other additive. However, in this case, the reliability and storage stability of the ink are degraded, and the coloring material or additives are not dissolved or dispersed, so that the ink cannot be formed.

In the ink set of the present invention, no special measures are taken to prevent bleeding between color inks of different colors. However, since color inks are often used in images and graphs, color inks are used. Is designed so that it can have a high permeability to the sized paper, practically, the printing quality does not significantly decrease.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to preferred embodiments of the present invention. The ink set of the present invention is a black ink containing, as a coloring material, a self-dispersible carbon black in which at least one hydrophilic group is bonded directly or via another atomic group to the surface of the carbon black, and An ink set for ink jet recording comprising a color material having a polarity opposite to the color material in the black ink and a color ink of another color.
More preferably, the self-dispersible carbon black is a cationic group.

Hereinafter, constituent materials of each ink of the ink set of the present invention will be described. First, in the black ink constituting the ink set of the present invention, as a coloring material of the black ink, a self-dispersion type in which at least one hydrophilic group is bonded directly or via another atomic group to the surface of carbon black. Use carbon black. As a result of using such a self-dispersion type carbon black as a coloring material, the carbon black in the ink can be dispersed in an aqueous medium in a stable state without using a dispersant. In the present invention, a hydrophilic group bonded directly or via another atomic group to the surface of carbon black includes, for example, a phenyl group, a benzyl group, a phenacyl group,
It is preferably composed of at least one aromatic group such as a naphthyl group or a heterocyclic group such as a pyridyl group and at least one cationic group. Also, more preferably,
The cationic group bonded to the surface of the carbon black is preferably a quaternary ammonium group. or,
What has a quaternary phosphonium group instead of a quaternary ammonium group is also used.

The hydrophilic group bonded to the surface of carbon black preferably used in the present invention specifically includes those having the following structures.
However, the present invention is not limited to these.

The content of the self-dispersible carbon black having a hydrophilic group bonded to the surface as described above in the ink is not particularly limited, but may be 0.5% of the total weight of the ink.
To 10.0%, particularly preferably 1.
It is preferable to set it in the range of 0 to 5.0%. That is, by setting the content within this range, for example, the reliability as an inkjet ink such as the print density and the ejection stability of the ink can be further improved.

The ink set of the present invention has at least one color ink in addition to the black ink having the above configuration. The color ink used in the present invention has a polarity opposite to that of the color material of the black ink. A coloring material is used. As the coloring material, a dye or a pigment is used.In the present invention, instead of a coloring material having a polarity opposite to the polarity of the coloring material of the black ink, an ink containing a compound having a polarity opposite to the coloring material of the black ink is used. May be used. As described above, anionic coloring materials are often used from the viewpoint of light resistance and safety, and many coloring materials for anionic color inks have excellent water resistance. In consideration of color development, anionic coloring materials, particularly anionic dyes, have been preferably used. Therefore, in this case, it is preferable to use cationic self-dispersion type carbon black in order to suppress bleeding between the black ink and the color ink.

As the colorant for the color ink, most of the anionic dyes to be used at this time can be used as long as they have an appropriate color tone and density, even if they are existing ones or newly synthesized ones. can do. The dyes can be used alone or in combination. Specific examples of the anionic dye include a dye having at least one carboxyl group.

Dyes having a carboxyl group are particularly preferably used in the present invention because of their excellent water resistance. That is, in the ink set of the present invention, as described above, since the self-dispersion type carbon black is used as the coloring material of the black ink, an image having excellent water resistance can be obtained. If a dye having a carboxyl group excellent in water resistance is used for the coloring material, an image excellent in water resistance is formed in the black ink and all color inks, and the obtained color print image has excellent water resistance. Become. Further, since the dye having a carboxyl group has a polarity opposite to that of the self-dispersion type carbon black having a cationic group described above, when the black ink and the color ink are adjacent to each other on the recording medium, the boundary portion between the black ink and the color ink is Thus, a bleed phenomenon caused by mixing of the ink is effectively prevented, and a beautiful color print can be obtained. Specific examples of the dye having at least one carboxyl group include those having the following structural formulas, but the present invention is not limited thereto.

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

The content of the coloring material is preferably in the range of 0.2 to 8% by weight, more preferably in the range of 0.5 to 5% by weight based on the total weight of the ink. That is, by setting the content in this range, for example, the reliability as an inkjet ink, such as the color developability and the ejection stability of the ink, can be further improved. When producing a black ink and a color ink having the above-described coloring material, it is preferable to use a mixture of water and a water-soluble organic solvent as a liquid medium for dispersing or dissolving the coloring material described above.

Specific examples of the water-soluble organic solvent used at this time include, for example, amides such as dimethylformamide and dimethylacetamide; ketones such as acetone; ethers such as tetrahydrofuran and dioxane;
Polyalkylene glycols such as polyethylene glycol and polypropylene glycol; ethylene glycol;
Alkylene glycols having an alkylene group containing 2 to 6 carbon atoms, such as propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol, diethylene glycol; glycerin; ethylene glycol Lower alkyl ethers of polyhydric alcohols such as monomethyl (or ethyl) ether, diethylene glycol monomethyl (or ethyl) ether, and triethylene glycol monomethyl (or ethyl) ether; N-methyl-2-pyrrolidone, 1,3-dimethyl-2 -Imidazolidinone, triethanolamine, sulfolane, dimethyl sulfoxide, 2-pyrrolidone, cyclic amide compounds such as ε-caprolactam, and imide compounds such as succinimide. It is. The content of these water-soluble organic solvents in the ink is generally preferably from 1 to 80% by weight, more preferably from 3 to 5% by weight, based on the total weight of the ink.
The range is 0% by weight.

In the color ink constituting the ink set of the present invention, in addition to the components described above, each of the color inks has the same polarity as the color material in the ink, or at least a nonionic property. It is preferable to include one type of surfactant. By including these surfactants,
Desired permeability and viscosity can be imparted to the color ink, and the performance required for the ink for inkjet recording can be further satisfied.

The surfactant used in this case includes:
Any of an ionic surfactant, a nonionic surfactant and an amphoteric surfactant, or a mixture of two or more thereof may be used. Specifically, for example, fatty acid salts, higher alcohol acid ester salts, alkylbenzene sulfonates,
Anionic surfactants such as higher alcohol phosphate ester salts, aliphatic amine salts, cationic surfactants such as quaternary ammonium salts, higher alcohol ethylene oxide adducts, alkylphenol ethylene oxide adducts, aliphatic ethylene oxide adducts, Polyhydric alcohol fatty acid ester Ethylene oxide adduct, aliphatic amide ethylene oxide adduct, higher alkylamine ethylene oxide adduct, polypropylene glycol ethylene oxide adduct, fatty acid ester of polyhydric alcohol, nonionicity of fatty acid amide of alkanolamine Surfactants, amino acid type, betaine type amphoteric surfactants and the like can be mentioned. In the present invention, any of these is preferably used, and more preferably, an ethylene oxide adduct of a higher alcohol, an ethylene oxide adduct of an alkylphenol, an ethylene oxide-propylene oxide copolymer, an ethylene oxide adduct of acetylene glycol And the like. Further, those having an addition mole number of the ethylene oxide adduct in the range of 4 to 20 are particularly preferable.

The amount of the surfactant to be added in the color ink is not particularly limited, but is preferably in the range of 0.01 to 10% by weight based on the total weight of the ink. If the amount is less than 0.01% by weight, depending on the type of surfactant, desired permeability cannot be generally obtained. If the amount exceeds 10% by weight, the initial viscosity of the ink increases, which is not preferable. More preferably, 0.1-5.
The content is preferably in the range of 0% by weight.

In addition, in addition to the above components, urea or a urea derivative as an alkali supplier or a urea derivative for imparting desired performance to the ink may be contained in each ink constituting the ink set of the present invention, if necessary. Additives such as a pH adjuster, a viscosity adjuster, a preservative, an antioxidant, an evaporation accelerator, a rust inhibitor, a fungicide, and a chelating agent may be added.

The above-described ink set of the present invention is suitably used in an ink-jet recording method in which ink droplets are ejected from an orifice in accordance with a recording signal to perform recording on a recording medium. It is particularly suitably used in an ink jet recording system for performing recording by discharging ink droplets. As a recording method for suitably performing recording using the ink set of the present invention, there is provided an ink jet recording method in which thermal energy corresponding to a recording signal is applied to inks of respective colors accommodated in a recording head and droplets are generated by the energy. An example of the inkjet recording apparatus of the present invention to which such an inkjet recording method is applied will be described below.

First, FIGS. 1, 2 and 3 show examples of the configuration of a head which is a main part of the apparatus. FIG. 1 is a cross-sectional view of the head 13 along the ink flow path, and FIG.
It is sectional drawing in the B line. The head 13 includes a glass, ceramic or plastic plate having a groove 14 through which ink passes, and a heat generating head 15 used for thermal recording (a thin film head is shown in the figure, but is not limited to this). And obtained by bonding. The heating head 15 has a good heat dissipation property such as a protective film 16 formed of silicon oxide or the like, aluminum electrodes 17-1 and 17-2, a heating resistor layer 18 formed of nichrome or the like, a heat storage layer 19, and alumina. It consists of a substrate 20.

The ink 21 has a discharge orifice (fine hole) 2
2, and the meniscus 23 is formed by the pressure P. Now, when electric signal information is applied to the aluminum electrodes 17-1 and 17-2, the area of the heating head 15 indicated by n rapidly generates heat, and bubbles are generated in the ink 21 in contact with the area. The meniscus 23 protrudes, the ink 21 is ejected to form an ink droplet 24, and flies from the ejection orifice 22 toward the recording medium 25.

FIG. 3 is an external view of a multi-head in which many heads shown in FIG. 1 are arranged. The multi-head is manufactured by closely contacting a glass plate 27 having a multi-groove 26 and a heating head 28 similar to that described with reference to FIG.

FIG. 4 shows an example of an ink jet recording apparatus incorporating the above head. In FIG. 4, reference numeral 61 denotes a blade as a wiping member, one end of which is held by a blade holding member to become a fixed end, and forms a cantilever. The blade 61 is arranged at a position adjacent to a recording area of the recording head 65, and in the present example, is held in a form protruding into the movement path of the recording head 65. Reference numeral 62 denotes a cap on the ejection port surface of the recording head 65, which is disposed at a home position adjacent to the blade 61, moves in a direction perpendicular to the moving direction of the recording head 65, contacts the ink ejection port surface, and performs capping. Is provided. Further, reference numeral 63 denotes an ink absorber provided adjacent to the blade 61, which is held in a form protruding into the movement path of the recording head 65, similarly to the blade 61.

The blade 61, the cap 62, and the ink absorber 63 constitute an ejection recovery section 64, and the blade 61 and the ink absorber 63 remove water, dust, and the like from the ink ejection port surface. 65 is a recording head that has ejection energy generating means, and performs recording by ejecting ink to a recording medium facing an ejection port surface where ejection ports are arranged;
Reference numeral 66 denotes a carriage on which the recording head 65 is mounted and moved. The carriage 66 is slidably engaged with the guide shaft 67, and a part of the carriage 66 is a motor 68.
(Not shown) connected to the belt 69 driven by the motor. As a result, the carriage 66 can move along the guide shaft 67, and the recording head 65 can move the recording area and the adjacent area.

Reference numeral 51 denotes a paper feed unit for inserting a recording medium, and reference numeral 52 denotes a paper feed roller driven by a motor (not shown). With such a configuration, the recording medium is fed to a position facing the discharge port surface of the recording head 65, and is discharged to a discharge section provided with a discharge roller 53 as recording proceeds.

In the above configuration, when the recording head 65 returns to the home position at the end of recording or the like, the cap 62 of the ejection recovery unit 64 is retracted from the moving path of the recording head 65, but the blade 61 protrudes into the moving path. I have. As a result, the ejection port surface of the recording head 65 is wiped.
When capping is performed with the cap 62 in contact with the ejection surface of the recording head 65, the cap 62 moves so as to protrude into the movement 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 the position at the time of wiping described above. As a result, the ejection port surface of the recording head 65 is also wiped during this movement. The movement of the print head 65 to the home position is performed not only at the end of printing or at the time of ejection recovery, but also at the home position adjacent to the printing area at a predetermined interval while the printing head 65 moves through the printing area for printing. And the wiping is performed with this movement.

FIG. 5 is a diagram showing an example of an ink cartridge 45 containing ink supplied to the head via an ink supply member, for example, a tube. Where 4
Reference numeral 0 denotes an ink storage unit that stores the supply ink, for example, an ink bag, and a rubber stopper 42 is provided at the tip of the ink storage unit. 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 the waste ink.
It is preferable for the present invention that the ink container has a surface in contact with the ink made of polyolefin, particularly polyethylene.

The ink jet recording apparatus of the present invention is not limited to the above-described head and the ink cartridge which are separated from each other, but may be suitably used for an integrated apparatus as shown in FIG. In FIG. 6, reference numeral 70 denotes a recording unit, in which an ink storage unit storing ink, for example, an ink absorber is stored, and a head unit having a plurality of orifices in which the ink in the ink absorber is stored. It is configured to be ejected from 71 as ink droplets.

As the material of the ink absorber, it is preferable for the present invention to use polyurethane, cellulose polyvinyl acetate or polyolefin resin. 72
Denotes an air 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 shown in FIG. 4, and is detachable from the carriage 66.

In the recording apparatus of the present invention, an ink jet recording apparatus which ejects ink droplets by applying thermal energy to ink has been described above as an example. However, the present invention is also applicable to a piezo system using a piezoelectric element and the like. Can be used in the same manner as described above.

[0048]

Next, the present invention will be described more specifically with reference to examples and comparative examples. In the following description, parts and% are based on weight unless otherwise specified. Carbon black 1 H in water ^{_{30g 3 N + C 6 H 4}} N + (CH 3) 3 Cl - · I - 3.
1.69 g of silver nitrate is added with stirring to the solution in which 08 g is dissolved. The generated precipitate was removed by filtration, and the filtrate was added to 70 g of water and DBPA having a specific surface area of 230 m ² / g.
Is added to a suspension in which 10 g of carbon black of 70 ml / 100 g are dispersed. Next, 2.25
g of concentrated hydrochloric acid and then a solution of 0.83 g of sodium nitrite in 10 g of water. Then, a diazonium salt having a NN ⁺ C ₆ H ₄ N ⁺ (CH ₃ ) ₃ group having a structure shown below reacts with carbon black to generate nitrogen gas. When the bubbling of the nitrogen gas stops, remove the dispersion
Dry in an oven at 20 ° C. As a result, a product in which C ₆ H ₄ N ⁺ (CH ₃ ) ₃ groups were attached to the surface of carbon black was obtained.

Carbon black 2 2.12 g of 4-acetaminophenacyl chloride,
A solution of 0.83 g pyridine, 6.4 g dimethyl sulfoxide is stirred overnight. An additional 0.8 g of pyridine,
After addition of 1 g of dimethylsulfoxide, the solution is stirred for a further 5 hours. 50 ml of ether are added and the acetamidophenacylpyridinium chloride is collected by filtration. The obtained acetamidophenacylpyridinium chloride is dissolved in water, and the solution is filtered.
7 g of concentrated hydrochloric acid are added. After boiling this solution for 1 hour,
After cooling, acetone is added and 4-aminophenacylpyridinium chloride hydrochloride is obtained by filtration. 3. Dissolve 2 g of the obtained 4-aminophenacylpyridinium chloride hydrochloride in 15 g of water;
5 g of basic ion exchange resin (Amberlite I)
RA400-OH). After stirring, the mixture is filtered to remove the ion exchange resin to obtain an aqueous solution of 4-aminophenacylpyridinium chloride. 1.3 g of 4 in 25 g of water
Refluxing the aqueous solution containing the aminophenacylpyridinium chloride with 1 g of silver nitrate for 90 minutes; The generated precipitate is removed by filtration. Specific surface area is 200m
5 g of carbon black, ² g / g, DBPA 122 ml / 100 g are added and the mixture is heated to about 80 ° C. 0.5
2 g of concentrated hydrochloric acid are added, and then a solution of sodium nitrite dissolved in a small amount of water is added to further disperse the dispersion 1.5 times.
Stir for hours. As a result, NN having the structure shown below
⁺ A diazonium salt having a C ₆ H ₄ COCH ₂ (N ⁺ C ₅ H ₅ ) group is formed and reacts with carbon black. As a result, a product in which C ₆ H ₄ COCH ₂ (N ⁺ C ₅ H ₅ ) groups are attached to the surface of carbon black is obtained.

Pigment Dispersion 1 15 parts of a styrene-acrylic acid-ethyl acrylate copolymer (acid value: 174, average molecular weight: 18,000), 4.5 parts of monoethanolamine, 5 parts of ethylene glycol, and 57 parts of water The parts are mixed and heated to 70 ° C. in a water bath to completely dissolve the resin component. At this time, if the concentration of the resin to be dissolved is low, the resin may not be completely dissolved. Therefore, when dissolving the resin, 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 (MCF-88, pH 8.0, manufactured by Mitsubishi Kasei) and 5 parts of ethanol were added, and premixing was performed for 30 minutes. Disperser: Sand grinder (Igarashi Kikai), grinding media: Zirconium beads 1mm
Diameter, filling rate of grinding media: 50% (volume), grinding time: 3 hours, and centrifugation (12,000 RP)
M, 20 minutes) to remove the coarse particles to obtain a pigment dispersion 1.

Pigment dispersion 2 3,943 g of tetrahydrofuran and p-xylene
4 g were charged into a 12 l flask equipped with a mechanical stirrer, thermometer, nitrogen inlet, drying tube inlet and addition funnel. Next, the catalyst, tetrabutylammonium-chlorobenzoate (2.6 ml of a 1.0 M solution in acetonitrile) was added. Then, 1-methoxy-1-trimethylsiloxy-2-methylpropene, 274.1 g (1.57M)
Was injected. And 780 g of methyl methacrylate
(7.8M) and 1,846 g (11.76M) of 2-dimethylaminoethyl methacrylate were added over 45 minutes. 100 minutes after completion, 1,556 g (15.6M) of methyl methacrylate was added over 30 minutes. After 400 minutes, 546 g of dry methanol was added to this solution.
Was added and distillation was started. After removing 2,025 g of the solvent in total, 1,331 g of 1-propanol was added after the distillation was completed. This block polymer was added to polymer solution 1
To 02.5 g was added 17.2 g of 85% phosphoric acid and neutralized by mixing until a homogeneous solution was obtained. Thereafter, it was diluted to about 25% with deionized water. 40 g of this block polymer was treated with black pigment FW-18 (Degu).
(ssa) and 140 g of deionized water.
Next, the mixture was added to a minimill 100 (Eiger Ma).
chinery), milled at 3,500 RPM for 1 hour, 10% pigment and 2: 1 pigment:
A pigment dispersion liquid 2 having a block polymer ratio (2/1) was obtained.

Pigment dispersion 3 300 g of acidic carbon black MA-8 (manufactured by Mitsubishi Kasei)
Is thoroughly mixed with 1,000 ml of water, and 450 g of sodium hypochlorite (effective chlorine concentration: 12%) is dropped, and
It was oxidized by stirring at 105 ° C. for 8 hours. The obtained slurry was applied to Toyo Filter Paper No. After filtering with 2, the product was thoroughly washed with water to remove by-product salts. The obtained wet cake is 3,000 m in water
1 and purified and concentrated using a reverse osmosis membrane to obtain a pigment dispersion liquid 2 having a pigment concentration of 10% by weight. As a result, an anionic self-dispersion type carbon black in which a -COONa group was bonded to the surface of the carbon black was obtained, and the carbon black was dispersed in the pigment dispersion 2 in a favorable state.

Examples 1-3 and Comparative Examples 1-6 Examples 1-3 and Comparative Examples 1-6 were prepared by combining black ink and yellow, magenta and cyan color inks.
Was prepared. The components listed below were used for each ink. As a production method, first, the following components were dissolved, and then Examples 1 to 3 and Comparative Examples 3 to 5 were further dissolved.
The pressure of the black ink of the ink set is filtered using a micro filter having a pore size of 3 μm (manufactured by Fuji Film), and the other inks are pressurized using a micro filter having a pore size of 0.22 μm (manufactured by Fuji Film). After filtration, each ink was prepared.

Ink set black ink of Example 1・ 4 parts of the above carbon black 1 (cationic) ・ 8 parts of ethylene glycol ・ 5 parts of triethylene glycol ・ 6 parts of 1,5-pentanediol ・ 77 parts of water

Yellow ink C.I. I. Acid Yellow 23 (anionic) 3 parts ・ Glycerin 5 parts ・ Diethylene glycol 5 parts ・ Urea 7 parts ・ Ethylene oxaoid-propylene oxide copolymer (trade name: Pepol AS-053X, manufactured by Toho Chemical Industry) 1 part ・ Water 79 Department

Magenta ink C.I. I. Acid Red 52 (anionic) 4 parts ・ 2-pyrrolidone 7 parts ・ Triethylene glycol monomethyl ether 7 parts ・ Urea 7 parts ・ Ethylene oxaide-propylene oxide copolymer (trade name: Pepol AS-053X, manufactured by Toho Chemical Industry Co., Ltd.) 1 part ・ Water 74 parts

Cyan ink C.I. I. Direct Blue 199 (anionic) 3 parts ・ Propylene glycol 8 parts ・ 1,2,6-hexanetriol 7 parts ・ Urea 6 parts ・ Ethylene oxoid-propylene oxide copolymer (trade name: Pepol AS-053X, Toho Chemical) Industrial) 1 part ・ Water 75 parts

Ink set black ink of Example 2・ 3 parts of the above carbon black 1 (cationic) ・ 9 parts of glycerin ・ 5 parts of propylene glycol ・ 5 parts of ethylene glycol ・ 3 parts of isopropyl alcohol ・ 75 parts of water

Yellow ink 3 parts of Exemplified Compound 1 (anionic) 3 parts 2-pyrrolidone 8 parts ε-caprolactam 8 parts hexylene glycol 5 parts acetylenol EH (Kawaken Fine Chemical) 1 part Water 75 parts

Magenta ink • 2 parts of Exemplified Compound 13 (anionic) • 6 parts of triethylene glycol • 5 parts of sulfolane • 7 parts of butylene glycol • 1 part of acetylenol EH (manufactured by Kawaken Fine Chemicals) 1 part • 79 parts of water

Cyan Ink • 3 parts of Exemplified Compound 21 (anionic) • 9 parts of propylene glycol • 7 parts of ethylene glycol • 7 parts of 2-pyrrolidone • 1 part of acetylenol EH (manufactured by Kawaken Fine Chemical) • 33 parts of water

[0062]Example 3 ink set  Black ink ・ 3 parts of the above carbon black 2 (cationic) ・ 7 parts of glycerin ・ 7 parts of ethylene glycol ・ 8 parts of trimethylolpropane ・ 3 parts of isopropyl alcohol ・ 72.0 parts of water

Yellow ink 3 parts of the exemplified compound 7 (anionic) 8 parts of glycerin 9 parts of diethylene glycol 6 parts of urea 1 part of acetylenol EH (manufactured by Kawaken Fine Chemical) 1 part of 73 parts of water

Magenta ink ・ 3 parts of the above-mentioned exemplified compound 16 (anionic) ・ 6 parts of glycerin ・ 8 parts of propylene glycol ・ 8 parts of urea ・ 1 part of acetylenol EH (manufactured by Kawaken Fine Chemical) 1 part ・ 74 parts of water

Cyan ink • 4 parts of Exemplified Compound 23 (anionic) • 7 parts of glycerin • 5 parts of triethylene glycol • 8 parts of urea • 1 part of acetylenol EH (manufactured by Kawaken Fine Chemical) 1 part • 75 parts of water

Ink Set Black Ink of Comparative Example 1 I. Direct Black 195 (anionic) 3 parts ・ Glycerin 6 parts ・ Diethylene glycol 5 parts ・ Urea 6 parts ・ Isopropyl alcohol 3 parts ・ Water 77 parts

For the yellow ink, magenta ink and cyan ink, the same anionic color inks as used in Example 1 were used.

Ink set black ink of Comparative Example 2・ Aizen Catilion Black SH (manufactured by Hodogaya Chemical) 3 parts ・ Diethylene glycol 10 parts ・ Ethyl alcohol 5 parts ・ Triethylene glycol 5 parts ・ Water 77 parts

The same anionic color inks as used in Example 1 were used for the yellow, magenta and cyan inks.

Ink set black ink of Comparative Example 3-50 parts of the above-mentioned dispersion liquid 1 (anionic)-9 parts of glycerin-9 parts of ethylene glycol-3 parts of ethanol-a small amount of 1N-HCl-29 parts of water Liquid, glycerin, ethylene glycol, ethanol and 15 parts of water, and then 1N-HC
After adjusting the pH of the solution to 7 to 9 with water, water was added thereto, and
00 parts.

As the yellow ink, magenta ink and cyan ink, the same anionic color ink as used in Example 2 was used.

Ink set black ink of Comparative Example 4-35 parts of the above-mentioned dispersion liquid 2 (cationic)-5 parts of Liponic EG-1 (manufactured by Lipo Chemicals)-5 parts of diethylene glycol-55 parts of water

As the yellow ink, magenta ink and cyan ink, the same anionic color ink as used in Example 3 was used.

Ink set of Comparative Example 5 Black ink ・ 30 parts of the above dispersion 3 (anionic) ・ 6 parts of glycerin ・ 5 parts of 2-pyrrolidone ・ 5 parts of ethylene glycol ・ 0.1 parts of acetylenol EH (manufactured by Kawaken Fine Chemical)・ 53.9 parts of water

The same anionic color inks as used in Example 2 were used for the yellow, magenta and cyan inks, respectively.

Ink Set Black Ink of Comparative Example 6 A black ink having the same anionic colorant as used in Comparative Example 5 was used.

Yellow ink 3 parts of the exemplified compound 3 (anionic) 8 parts of diethylene glycol 7 parts of 1,5-pentanediol 6 parts of urea 1 part of acetylenol EH (manufactured by Kawaken Fine Chemical) 1 part of magnesium nitrate 1 part 74 parts of water

Magenta ink • 3 parts of the above exemplified compound 20 (anionic) • 6 parts of glycerin • 7 parts of triethylene glycol • 9 parts of urea • 1 part of acetylenol EH (manufactured by Kawaken Fine Chemical) 1 part • 1 part of magnesium nitrate • 73 parts of water

Cyan Ink • 3 parts of Exemplified Compound 28 (anionic) • 7 parts of ethylene glycol • 7 parts of N-methyl-2-pyrrolidone • 7 parts of urea • 1 part of acetylenol EH (manufactured by Kawaken Fine Chemical) 1 part of magnesium nitrate 1 Part / Water 74 parts An attempt was made to produce a color ink using the above components, but these three color inks could not be converted into ink.

Each ink of the ink sets of Examples 1 to 3 and Comparative Examples 1 to 5 of the present invention obtained above was used as BC-2
One cartridge (manufactured by Canon Inc.) was filled to prepare an ink jet cartridge. Table 1 summarizes the compositions of the ink sets of Examples 1 to 3 and Comparative Examples 1 to 6. In addition, none of the color inks of Example 6 could be made into ink.

[0081]

Table 1: Composition of ink sets of Examples and Comparative Examples

Next, the above Examples 1 to 3 and Comparative Examples 1 to
BJC-4000 which is an inkjet recording apparatus having an on-demand type multi-recording head that ejects the ink by applying thermal energy according to the recording signal to the ink using the inkjet cartridge obtained in Step 5
(Manufactured by Canon Inc.), a printing test was performed, and the following items (1) to (4) were evaluated. Table 1 shows the results thus obtained. (1) Light resistance of black ink (2) Water resistance of four color inks (3) Bleeding between black ink and color ink (4) Long-term ejection stability of black ink The above (1) to (3) In the evaluation test, Canon copy paper: PB PAPER and Xerox: 4024
Two plain papers of PAPER were used, and in the evaluation test of (4), Canon copy paper: PB PAPER was used.

Evaluation Method and Evaluation Criteria (1) Light Resistance of Black Ink A solid image was printed on the above two plain papers with black ink, and the reflection density was measured with a reflection density meter Macbeth RD915 (manufactured by Macbeth). . Next, a xenon fade-ometer is added to the solid image of the black ink.
After continuously irradiating with 3.9 kW light for 100 hours (manufactured by ATLAS), the reflection density of the solid image was measured again. Then, the residual ratio of the printed matter density was obtained from the following formula, and the light resistance was evaluated according to the following evaluation criteria. Residual rate (%) = (Print density after irradiation for 100 hours) / (Initial print density) × 100 ○: Residual rate is 95% or more △: Residual rate is 80% or more and less than 95% ×: Residual rate is 80% Less than

(2) Water resistance of four color inks On the two plain papers described above, alphanumeric characters are printed with each color ink constituting each ink set, and one hour after printing,
The paper was tilted at a 45 degree angle and 0.75 ml of tap water was drawn from the top of the paper with a pipettor, allowing the water to flow over the alphanumeric characters. The state of the alphanumeric characters at that time was visually observed to evaluate the water resistance. The evaluation criteria were as follows. ：: No character stain, no bleeding, etc. were seen in the part where tap water flowed down. ○: Slightly dirty letters in the part where tap water flowed down
Bleeding is seen but no problem. Δ: Slight character dirt on part where tap water flowed down
Bleeding and the like are observed. ×: The character stain and bleeding of the part where the tap water flowed down was severe.

(3) Bleeding between Black Ink and Color Ink A solid portion is printed on the two plain papers with the black ink in each ink set, and immediately thereafter, yellow or magenta, Alternatively, a solid portion of each color ink was printed with cyan ink. The boundary portion of the obtained solid print was visually observed to evaluate bleeding between the black ink and the color ink. The evaluation criteria were as follows. ：: No bleeding was observed at all boundaries. ：: Slight bleeding was observed, but not much of a concern. Δ: Slight bleeding is observed. ×: Bleeding was severe at almost all boundaries.

(4) Long-term ejection stability of black ink The black ink in each ink set was subjected to a continuous printing test at 25 ° C. for 100 hours, and the presence or absence of printing disorder, chipping, non-ejection, etc. was observed. The long-term ejection stability was evaluated. The evaluation criteria were as follows. ：: There is no printing disorder, chipping or non-discharge during the test for 100 hours. ×: Disturbance in printing occurred before the test for 100 hours was completed, and some of the nozzles did not discharge.

[0087]

[Table 2] Table 2: Evaluation results However, the PB paper in the table is Canon copy paper: PB
PAPER, XX paper: Xerox: 402
Represents 4 PAPER.

[0088]

As described above, according to the present invention,
High print density Excellent water resistance, light resistance, excellent print quality Black ink images can be obtained, long-term storage stability of ink, wettability to face face of head, clogging, uniformity, printing Ink set for ink jet recording having black ink having excellent ink properties such as durability, and further, when a color image is formed, bleeding between this black ink and ink of another color is effectively prevented. Is provided, so that a color image having good print quality and excellent in water resistance and light resistance can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a head of an ink jet recording apparatus.

FIG. 2 is a cross-sectional view of a head of the inkjet recording apparatus.

FIG. 3 is an external perspective view of a head obtained by multiplying the head shown in FIG. 1;

FIG. 4 is a perspective view illustrating an example of an ink jet recording apparatus.

FIG. 5 is a vertical sectional view of the ink cartridge.

FIG. 6 is a perspective view illustrating an example of a recording unit.

[Explanation of symbols]

 13: Head 14: Ink groove 15: Heating head 16: Protective film 17: Aluminum electrode 18: Heating resistor layer 19: Heat storage layer 20: Substrate 21: Ink 22: Discharge orifice (fine hole) 23: Meniscus 24: Small ink Drop 25: Recording material 26: Multi-groove 27: Glass plate 28: Heating head 40: Ink bag 42: Plug 44: Ink absorber 45: Ink cartridge 51: Paper feed unit 52: Paper feed roller 53: Paper discharge roller 61 : Blade 62: Cap 63: Ink absorber 64: Ejection recovery unit 65: Recording head 66: Carriage 67: Guide shaft 68: Motor 69: Belt 70: Recording unit 71: Head part 72: Atmospheric communication port

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshihisa Takizawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Norifumi Hattori 3- 30-2 Shimomaruko, Ota-ku, Tokyo Kia Non Corporation

Claims (21)

[Claims] An ink jet recording ink set for recording a color image on a recording material using at least two colors of ink including at least a black ink and a color ink, wherein the black ink is a carbon material as a coloring material. On the surface of black, a self-dispersible carbon black in which at least one hydrophilic group is bonded directly or via another atomic group, and the polarity of the coloring material in at least one color ink is the black. An ink set for ink-jet recording, which has a polarity opposite to that of a color material in the ink. 2. An ink jet recording ink set for recording a color image on a recording material using two or more colors of ink including at least a black ink and a color ink, wherein the black ink contains carbon as a coloring material. A self-dispersible carbon black in which at least one hydrophilic group is bonded directly or via another atomic group on the surface of the black, and in at least one color ink, a color material in the black ink; An ink set for ink-jet recording, comprising a colorant and a compound having polarities opposite to the polarities of the above. 3. The ink set according to claim 1, wherein the self-dispersible carbon black is cationic. 4. The ink set according to claim 1, wherein the hydrophilic group comprises at least one aromatic group or heterocyclic group and at least one cationic group. 5. The ink set according to claim 4, wherein the cationic group is a quaternary ammonium group. 6. The ink set according to claim 5, wherein the quaternary ammonium group is any one represented by the following formula. 7. The ink set according to claim 1, wherein the hydrophilic group is introduced by a diazonium salt. 8. The ink set according to claim 1, wherein the color material in the ink other than the black ink is a dye having at least one carboxyl group. 9. An ink set according to claim 1, wherein the ink is ejected from an orifice according to a recording signal to perform recording on a recording material. An ink-jet recording method, characterized in that: 10. The ink jet recording method according to claim 9, wherein the ink is ejected by applying thermal energy to the ink. 11. An ink set according to claim 1, wherein in a recording unit provided with an ink containing section for containing ink and a head section for ejecting the ink as ink droplets, the ink is set in any one of claims 1 to 8. A recording unit, characterized in that: 12. A head for ejecting ink droplets by applying thermal energy to the ink.
A recording unit according to item 1. 13. The recording unit according to claim 11, wherein the ink containing section is made of polyurethane, cellulose, polyvinyl acetate, or polyolefin resin. 14. An ink cartridge having an ink storage section for storing ink, wherein the ink cartridge has an ink storage section.
An ink cartridge comprising the ink set according to claim 8. 15. The ink cartridge according to claim 14, wherein the ink container has a liquid contact surface formed of polyolefin. 16. An ink jet recording apparatus comprising: a recording unit having an ink container containing ink and a head for discharging the ink as ink droplets, wherein the ink is any one of claims 1 to 8. An ink jet recording apparatus comprising the ink set according to item 1. 17. A head for ejecting ink droplets by applying thermal energy to the ink.
3. The ink jet recording apparatus according to claim 1. 18. The ink jet recording apparatus according to claim 16, wherein the ink containing section is made of polyurethane, cellulose, polyvinyl acetate or polyolefin resin. 19. An ink jet recording apparatus comprising: a recording head for ejecting ink droplets; an ink cartridge having an ink container containing ink; and an ink supply unit for supplying ink from the ink cartridge to the recording head. 9. The ink according to claim 1, wherein the ink is an ink.
An ink jet recording apparatus comprising the ink set according to any one of the above. 20. The ink jet recording apparatus according to claim 19, wherein the recording head is a head that applies thermal energy to the ink to eject ink droplets. 21. The ink jet recording apparatus according to claim 19, wherein the ink containing section has a liquid contact surface formed of polyolefin.