JPH09151348A - Ink set, method for ink jet recording using the same and ink jet device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink set using an ink capable of giving enough picture concentration, having a high homogeneity in the picture concentration, especially preventing bleedings in color pictures, giving clear and uniform pictures in high quality and capable of improving letter characteristics in a printed matter in recording on common paper. SOLUTION: In this ink set combining two or more different color inks used for recording a color pictures on a material to be recorded by an ink jet recording method, the ink comprises a color material and a liquid medium as essential components, contains an anionic or a cationic surfactant at least in one color ink and an amphoteric ionic compound in the other ink having a color different from that of the above ink.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses an ink set of at least two or more primary colors, and an ink set used for recording a color image on a recording material by combining these primary color inks and ink jet recording. The method and the inkjet device, in particular, excellent in color development on plain paper in image recording by the inkjet method,
The present invention relates to an ink set capable of obtaining a clear and high-quality image and excellent in water resistance of a printed matter, an inkjet recording method using the same, and an inkjet device.

[0002]

2. Description of the Related Art Ink jet recording methods include an electrostatic attraction method by applying a high voltage, a method of mechanically vibrating or displacing ink (colored ink) using a piezoelectric element, and a pressure at which the ink foams when heated. A method of generating small droplets of ink by various ink ejection methods such as a method utilizing ink, flying these to adhere the ink to a recording material such as paper, and forming ink dots for recording. It is a recording system that generates less noise and can perform high-speed printing and multi-color printing.

In particular, Japanese Patent Publication No. 61-59 by the applicant of the present application.
911, Japanese Patent Publication No. 61-59912, Japanese Patent Publication No. 61-59914, etc.
That is, according to the method in which the electrothermal converter is used as the supply means of the ejection energy and the thermal energy is applied to the ink to generate the bubbles to eject the droplets, it is easy to realize the high density multi-orifice of the recording head. Therefore, a high-resolution and high-quality image can be recorded at high speed.

[0004]

However, the ink used in the conventional ink jet recording generally contains water as a main component, and a water-soluble high-boiling point solvent such as glycol is added thereto for the purpose of preventing drying and clogging. It is common that it contains. When recording is performed on plain paper using such an ink, the ink permeates into the inside of the recording material and a sufficient image density cannot be obtained, or a filler or sizing agent on the surface of the recording material is not obtained. The image density was non-uniform, which was probably due to the non-uniform distribution. In particular, when a color image is to be obtained, since the inks of a plurality of colors are successively overlapped with each other before the previously recorded ink is fixed, the color blurs or the ink Mixed unevenly (hereinafter referred to as bleeding)
No satisfactory image was obtained. Further, in recent years, the demand for water resistance of printed matter has been increasing, and from this point as well, a satisfactory water resistant printed matter has not been obtained.

As a means for solving the above-mentioned problems, Japanese Patent Laid-Open No.
Japanese Patent Laid-Open No. 5-65269 uses an ink in which a compound that enhances permeability such as a surfactant is added to the ink.
Further, Japanese Patent Laid-Open No. 55-66976 discloses the use of an ink mainly composed of a volatile solvent. Further, US Pat. No. 5,106,416 discloses an ink containing a cationic dye, an amphoteric surfactant and a nonionic amphiphile. Also, US Pat.
No. 0 discloses an ink containing a water-insoluble dye, a polymer colloid and a surfactant. Further, JP-A-60-96673 and JP-A-4-139272 disclose inks using a betaine type acrylic resin.

However, when the ink described in JP-A-55-65269 is added with a compound that enhances the permeability such as a surfactant, the permeability of the ink to the recording material is increased. Although the bleeding is improved and the bleeding is suppressed to some extent, the ink penetrates deeply into the recording material including the colorant, which causes a problem such as a decrease in image density. Further, since the wettability with respect to the surface of the recording material is improved, the ink is likely to spread on the surface of the recording material, resulting in a decrease in resolution and bleeding, which is not preferable. or,
When the ink mainly composed of a volatile solvent described in JP-A-55-66976 is used, in addition to the above-mentioned inconvenience, nozzle clogging due to evaporation of the solvent in the nozzle portion of the recording head is caused. It was easy to occur and was not preferable.

Further, in an ink containing a cationic dye, an amphoteric surfactant and a nonionic amphiphile as disclosed in US Pat. No. 5,106,416, by adding a surfactant at a critical micelle concentration or more, a colorant Although it is intended to prevent diffusion, basically, like the above-mentioned JP-A-55-65269, the action of the surfactant increases the permeability of the ink itself, and a desirable image cannot be obtained. Further, in the case of the ink containing the water-insoluble dye, the polymer colloid and the surfactant of US Pat. No. 5,342,440, in addition to the disadvantages of US Pat. No. 5,106,416, in the recording head and in the nozzle. The nozzles may be clogged due to precipitation of water-insoluble dye and aggregation of colloid, which is not preferable.

Further, in JP-A-60-96673 and JP-A-4-139272, an ink using a betaine type acrylic resin is used, the former is for the purpose of preventing bleeding of the oil-based ink, and the latter is It is disclosed that the above acrylic resin is added for the purpose of improving the stability of the pigment ink, but high image quality on plain paper cannot be obtained. Also here
Betaine-type acrylic resins certainly show amphoteric characteristics, but it is difficult to say that they have a cationic group and an anionic group clearly, and further, they have a monomer having an anionic group and a cationic group in the molecule. It is not a copolymer with monomers and has no isoelectric point. Therefore, it is basically different from the zwitterionic compound used in the present invention described later.

The present invention has been made in view of the above circumstances, and an object of the present invention is to obtain a sufficient image density in recording a recording material, particularly plain paper, and to obtain a high uniformity of the image density. In particular, the present invention provides an ink set comprising an ink capable of preventing bleeding in a color image, obtaining a clear and uniform high-quality image, and further improving the character quality of a printed matter, an inkjet recording method using the same, and an inkjet device. Especially.

[0010]

The above object is achieved by the present invention described below. That is, the present invention provides an ink set combining two or more different colors of ink used when a color image is recorded on a recording material by an inkjet recording method, wherein the ink contains a coloring material and a liquid medium as essential components. An ink set comprising at least one color ink containing an anionic or cationic surfactant, and an ink having a different color from the ink containing a zwitterionic compound. The inkjet recording method and inkjet apparatus used.

More specifically, for example, in the constitution of the ink set, the coloring material contained in at least one color of ink is an anionic dye, and the surfactant contained in the ink is an anionic interface. An activator, the coloring material contained in the ink of other colors is a cationic dye,
At the same time, the zwitterionic compound is contained in the ink, or the coloring material contained in the ink of at least one color is a cationic dye, and the surfactant contained in the ink is a cationic surfactant. In addition, the coloring material contained in the ink of other colors is an anionic dye, and at the same time, contains a zwitterionic compound in the ink.

In addition, the coloring material contained in the ink of at least one color is a pigment, the surfactant contained in the ink is a cationic surfactant, and further contained in the ink of other colors. The coloring material is an anionic dye and at the same time contains a zwitterionic compound in the ink. Similarly, the coloring material contained in the ink of at least one color is a pigment, the surfactant contained in the ink is an anionic surfactant, and the coloring material contained in the ink of other colors is , A cationic dye, and at the same time contain a zwitterionic compound in the ink.

[0013]

Next, the present invention will be described in more detail with reference to preferred embodiments. First, the operation of the ink set of the present invention will be described. For example, a preferred embodiment of the ink set of the present invention will be described as an example. An anionic dye and an anionic surfactant are used as constituent components of at least one color ink that constitutes the ink set, and the ink is further used. By using a cationic dye and a zwitterionic compound in combination with the constituent components of an ink of another color different from the above color, two or more different colors of ink are overprinted almost at the same time, or one of the inks When ink of a color different from that color is ejected adjacently before being dried on the recording material, it is possible to suppress color mixing of the ink.

As a result, it is possible to reduce feathering due to irregular line thickness of the obtained color image and boundary blurring between adjacent different colors. That is, when two different color inks having the above-described constituents are ejected adjacent to each other, when the anionic dyes and the cationic dyes, which are the pigments constituting each ink, contact each other. Because of the reaction to form an insoluble salt, rapid color mixing between liquids can be suppressed. However, if this is the case, the diffusion speed between the liquids of the two color inks is higher than the reaction insolubilization speed, and if the molecular weight of the insolubilized substance itself due to the reaction is insufficient, two different color liquids will The effect of suppressing color mixture is insufficient due to diffusion between the layers.

Therefore, in order to make this effect more sufficient, it is necessary to further increase the insolubilization reaction rate of the anionic substance and the cationic substance between the two different color inks, which is different. This can be achieved by increasing the number of reactive groups between the two color inks. Further, it is necessary to suppress the diffusion of the insolubilized product of the anionic substance and the cationic substance, which can be realized by increasing the molecular weight of the insolubilized product produced. Therefore, when the first ink contains an anionic dye, the number of anionic groups that are reactive groups is increased in the ink and the molecular weight of the salt-forming salt with the cationic substance of the second ink is increased. Can be achieved by simultaneously adding an anionic surfactant having a hydrophobic group with a large number of carbon atoms. Furthermore, if a zwitterionic compound is added to the second ink together with the cationic dye, the reaction product of both the cationic dye and the zwitterionic compound reacts with the anionic substance of the first ink, resulting in a higher molecular weight. It is possible to more effectively prevent the boundary bleeding when fixing the ink between two different color inks and the line thickening at the time of color mixing by making a high salt-forming compound.

Similarly, in the opposite case to the above case, when the first ink contains a cationic dye, the number of the reactive cationic groups is increased in the ink and the second ink is used. The increase in the molecular weight of the salt-forming salt with the anionic substance of the ink can be realized by simultaneously adding a cationic surfactant having a hydrophobic group with a large number of carbon atoms. Second
If the zwitterionic compound is added together with the anionic dye to the ink of (1), the reaction product of both the anionic dye and the zwitterionic compound reacts with the cationic substance of the first ink to produce a compound having a higher molecular weight. Boundary bleeding at the time of fixing the ink between two different colors by making a salt and line thickening at the time of color mixing are more effectively prevented.

In addition, even when an aqueous dispersion of a pigment or a water-insoluble dye such as an oily or disperse dye is used in the first ink, an anionic surfactant is also added to the second ink to make the second ink. When a cationic dye and a zwitterionic compound are used together, the pigment or the water-insoluble dye and the cationic dye do not dissolve each other when they come into contact with each other, but rather repel each other, which suppresses rapid color mixing between liquids. However, the reaction between the anionic substance and the cationic substance contained in both inks causes the contact portion between the two inks to change in physical properties such as thickening, so that the diffusion between the two inks may occur. It can be suppressed and the same effect can be expected. Or, conversely, when an aqueous dispersion of a pigment or a water-insoluble dye such as an oil-based or disperse dye is used in the first ink,
Similar effects can be expected if both the cationic surfactant is contained and the second ink contains both the anionic dye and the zwitterionic compound.

Next, the components constituting the ink set of the present invention will be described. First, the ink used in the ink set of the present invention is prepared by dissolving or dispersing an anionic dye, a cationic dye and a pigment, an anionic surfactant or a cationic surfactant, and a zwitterionic compound in a suitable liquid medium. Obtained. The concentration of the coloring material in such an ink is appropriately determined as desired, but normally,
The range is 0.001 to 20% by weight, preferably 0.01 to 15% by weight, and more preferably 0.01 to 10% by weight. The concentration of the anionic or cationic surfactant or the zwitterionic compound in the ink is appropriately determined as desired, but is usually 0.001 to 50% by weight, preferably 0.01 to 25% by weight, More preferably 0.0
The range is from 1 to 10% by weight.

The first and second inks which compose the ink set of the present invention as described above are constituted by dissolving or dispersing a dye or a pigment in a liquid medium. As the liquid medium used at this time, It is preferable to use a mixture of water and an organic solvent. When the liquid medium is in a mixed form, there is an advantage that a change in physical property or a change in chemical property (for example, pH value) of the ink is suppressed over an extremely long period (for example, 6 months or 1 year or more).

The organic solvent used in the present invention is appropriately selected from the water-soluble organic solvents listed below and used. Specifically, for example, methyl alcohol, ethyl alcohol, n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-
C1-C7 alkyl alcohols such as butyl alcohol, iso-butyl alcohol, amyl alcohol, n-hexanol, cyclohexanol; ketones or ketone alcohols such as acetone and diacetone alcohol; alkanols such as monoethanolamine and diethanolamine Amines; amides such as dimethylformamide and dimethylacetamide; ethers such as tetrahydrofuran and dioxane; 2 to 6 alkylene groups such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, thiodiglycol, butylene glycol and glycerin Alcohols containing carbon atoms of; ethylene glycol monomethyl (or ethyl or propyl) ether, diethylene glycol monomethyl (or Ethyl or butyl) ether,
Diethylene glycol dimethyl (or ethyl) ether, polyethylene glycol monomethyl (or ethyl)
Lower alkyl mono- or diethers derived from alkylene glycols such as ethers (total carbon number 3-8)
Nitrogen-containing 5-membered ring ketones such as 2-pyrrolidone and N-methyl-2-pyrrolidone; α-valero-lactone, ε
-Intramolecular esters of oxycarboxylic acids such as caprolactone and butyl lactone; morpholine, dimethylimidazolidine sulfolane and the like.

The content of the above water-soluble organic solvent in the ink is generally 5 to 90% by weight, preferably 10 to 80% by weight, more preferably 10 to 50% by weight.
The content of water is generally 10 to 90% by weight, preferably 10 to 70% by weight, more preferably 20% by weight.
To 70% by weight.

The anionic or cationic surfactant and the zwitterionic compound which are preferably used as the components of the ink constituting the ink set of the present invention may be existing ones or newly synthesized ones. As long as the required physical properties and the performance capable of achieving the object of the present invention are obtained, most of them can be used. First, as the anionic surfactant, for example, a hydrophilic group thereof has a carboxylate, a sulfonate, a sulfate ester salt, a phosphate ester salt or the like, and a hydrophobic group has a carbon number of 12 to 18
Paraffinic, olefinic, benzene having an alkyl group having 11 to 15 carbon atoms, alkylnaphthalene having 1 to 5 carbon atoms, alkylphenol having 12 to 18 carbon atoms, higher alcohol, higher mercaptan, 11 carbon atoms
To 18 higher fatty acids, higher fatty acid esters having 8 to 21 total carbon atoms, polyhydric alcohol fatty acid partial esters having 11 to 17 carbon atoms, higher fatty acid amides having 11 to 17 carbon atoms, other fats and oils, waxes, etc. Examples include those made from.

Examples of the cationic surfactant include, for example,
The hydrophilic group has a quaternary ammonium salt, a quaternary ammonium salt of benzyl halide, an amine salt, an alkanolamine salt, a pyridinium salt, and the like, and a hydrophobic group has a higher fatty acid and a higher amine having 12 to 34 carbon atoms. , Carbon number 11 ~
17 higher fatty acid amides, higher fatty acids having 11 to 18 carbon atoms such as higher alkyl halides having 11 to 17 carbon atoms, higher amines having 12 to 34 carbon atoms, higher fatty acid amides having 11 to 17 carbon atoms, and carbon numbers 11 to 17 are used as raw materials.

The zwitterionic compound used as a constituent component of the ink set of the present invention, whether existing or newly synthesized, has suitable physical properties required for the ink and the present invention. Most of the materials can be preferably used as long as the performance capable of achieving the above object can be obtained. Zwitterionic compounds include zwitterionic surfactants, which are preferably used in the present invention. As the amphoteric surfactant, specifically, for example, a hydrophobic group is a linear or branched alkylamine having 8 to 18 carbon atoms, an unsaturated alkylamine, an alkyl fatty acid, an alkyl halide, or the like, and a hydrophilic group is a polyamine, Monochloroacetate, acrylic acid, caprolactam, maleic acid, chloroalkyl sulfonates, amino sulfonates, ethylene oxide, aminoethyl ethanolamine, those synthesized from sulfating agents, betaine type compounds, amino acid derivatives, Examples thereof include imidazoline derivatives, and these can be used alone or in combination of several kinds as appropriate.

Further, as the zwitterionic compound used in the present invention, in addition to the above-mentioned amphoteric surfactant,
The compound represented by the following general formula (I) can also be preferably used. (In the formula, R ₁ represents an alkyl group having 1 to 48 carbon atoms or a hydrogen atom, R ₂ represents (CH ₂ ) _a —X ₁ or a hydrogen atom,
a is an integer of 1 to 4. R ₃ is (CH ₂ ) _b
Represents -X ₂ or R ₄ -Y or a hydrogen atom, and b is an integer of 1 to 4. R ₄ represents an alkyl group having 1 to 48 carbon atoms or a hydrogen atom. Z is (NR _{5 Cl} H _2l ) _c (N
HC _n H _2n ) _d , where l and n are integers from 2 to 4 and c + d is an integer from 0 to 50. Y represents _{(NR 6 C m H 2m)} e (NHC p H 2P) f, m and p
Is an integer of 2 to 4, and e + f is an integer of 0 to 50. R ₅ represents _{(CH 2) g -X 3,} g is 1
It is an integer from 4 to 4. R ₆ represents _{(CH 2) h -X 4,} h is an integer of 1-4. X ₁ , X ₂ ,
X ₃ and X ₄ are each selected from the group consisting of a carboxyl group, a salt of a carboxyl group, a sulfone group, a salt of a sulfone group and a hydrogen atom. Further, when R ₂ and R ₃ are each a hydrogen atom, both c and e never become 0, and X ₁ ,
X ₂ , X ₃ and X ₄ are not all hydrogen atoms. )

As the anionic dye used as a component of the ink constituting the ink set of the present invention, existing anion dyes or newly synthesized anionic dyes are usually used as long as they have appropriate color tone and density. Can be used. Further, any of these may be mixed and used. Specific examples of the anionic dye include the followings. C. I. Direct yellow 8, 11, 12, 27,
28, 33, 39, 44, 50, 58, 85, 86, 8
7, 88, 89, 98, 100, 110, C.I. I. Direct Red 2, 4, 9, 11, 20,
23, 24, 31, 39, 46, 62, 75, 79, 8
0, 83, 89, 95, 197, 201, 218, 22
0, 224, 225, 226, 227, 228, 23
0, C.I. I. Direct Blue 1, 15, 22, 25, 4
1, 76, 77, 80, 86, 90, 98, 106, 1
08, 120, 158, 163, 168, 199, 22
6,

C. I. Direct Black 17, 19, 22, 3
1, 32, 51, 62, 71, 74, 112, 113,
154, 168, 195, C.I. I. Acid Yellow 1, 3, 7, 11, 17,
23, 25, 29, 36, 38, 40, 42, 44, 7
6, 98, 99, C.I. I. Acid Red 6, 8, 9, 13, 14, 1
8, 26, 27, 32, 35, 42, 51, 52, 8
0, 83, 87, 89, 92, 106, 114, 11
5, 133, 134, 145, 158, 198, 24
9, 265, 289, C.I. I. Acid Blue 1, 7, 9, 15, 22, 2
3, 25, 29, 40, 43, 59, 62, 74, 7
8, 80, 90, 100, 102, 104, 117, 1
27, 138, 158, 161,

C. I. Acid Black 2, 48, 51, 52, 1
10, 115, 156, C.I. I. Reactive Yellow 2, 3, 17, 2
5, 37, 42, C.I. I. Reactive Red 7, 12, 13, 1
5, 17, 20, 23, 24, 31, 42, 45, 4
6, 59, C.I. I. Reactive Blue 4, 5, 7, 13, 1
4, 15, 18, 19, 21, 26, 27, 29, 3
2, 38, 40, 44, 100, C.I. I. Food Yellow 3, C.I. I. Hood Red 87, 92, 94, C.I. I. Food black 1, 2

As the cationic dye used as a component of the ink constituting the ink set of the present invention, existing cationic dyes or newly synthesized cationic dyes are usually used as long as they have appropriate color tone and density. Can be used. Further, any of these may be mixed and used. Specific examples of the cationic dye include the followings. C. I. Basic Yellow 1, 11, 13, 19,
25, 33, 36, C.I. I. Basic Red 1, 2, 9, 12, 13,
38, 39, 92, C.I. I. Basic Blue 1, 3, 5, 9, 19, 2
4, 25, 26, 28, 45, 54, 65, C.I. I. Basic Black 2, 8, Aizen Cathilon Black SBH, BXH, SH, AC
H, MH, TH (Hodogaya Chemical) Sumiacryl Black B, R, AP, BP, CP, FFP
(Sumitomo Chemical), Diacryl Supra Black GSL, RSL, ESL (Mitsubishi Kasei),

As the water-insoluble dye containing the disperse dye used as a component of the ink constituting the ink set of the present invention, those which are already on the market or those which are newly synthesized have appropriate color tone and density. Most of the dyes can be used, or a plurality of dyes can be mixed and used. Examples of the water-insoluble dye that can be used in the present invention include the followings.

C. I. Disperse Yellow 3, 4,
5, 7, 23, 33, 42, 49, 54, 56, 64,
71, 79, 82, 83, 86, 88, 93, 99, 1
16, 119, 141, 160, 163, 198, 20
4, 218, 224, 226, 230,

C. I. Disperse Red 1, 4,
5, 7, 11, 12, 13, 15, 17, 30, 33,
43, 50, 52, 53, 54, 55, 56, 58, 5
9, 60, 65, 72, 73, 74, 75, 76, 8
2, 86, 88, 90, 91, 92, 96, 105, 1
06, 107, 110, 117, 118, 126, 12
7, 128, 131, 132, 134, 135, 13
6, 137, 140, 143, 145, 146, 151
s, 153, 159, 164, 167, 169, 17
7, 181, 184, 188, 190, 191, 20
0, 203, 205, 206, 221, 223, 22
4, 225, 227, 229, 239, 240, 25
8, 277, 278, 279, 283, 288, 30
2, 309, 311, 312, 323, 329, 33
2, 340, 341, 343,

C. I. Disperse Blue 1, 3,
7, 13, 19, 26, 27, 35, 44, 54, 5
5, 56, 60, 64, 65, 72, 73, 79, 8
1, 82, 87, 91, 93, 94, 96, 102, 1
06, 118, 120, 122, 125, 128, 13
0, 139, 142, 143, 146, 148, 14
9, 153, 154, 165, 167, 181, 18
3, 185, 186, 189, 198, 200, 20
1, 205, 207, 214, 224, 225, 25
7, 259, 266, 268, 270, 284, 28
5, 287, 288, 291, 293, 301, 33
0, 332, 333, 337, 341, 345, 35
1, 352, 353,

C. I. Disperse Black 1, 9,
10, Black GL, Black B, Black
L, Black 2B, Black BT, Blac
kOBL, Black RSR, Black TK, B
black TG, Black S-CTL, Black
H-DB, Black RD-SGT, Black
S-2BL, Black S-3BL, Black S
-5BL, Black S-BNL, Black S-
3GLN, Black S-ST, Black S-F
GB, Black S-SGN, Black S-WL
A, Black S-WLAT, Black B82,
Black BTNU82, Black 2BL, Bl
ack HR-FS, Black RB-FS, Bla
ckHG-FS, Black GB-FS, Black
KN-FS. The water-insoluble dye suitable in the present invention is not limited to those listed above.

The existing pigment or the newly synthesized pigment which is suitable for the color component of the dispersion type ink used in the ink constituting the ink set of the present invention is suitable for the ink. Most of those having a color tone and density can be used. Specifically, for example, titanium-based, red iron oxide, aluminum powder,
Inorganic pigments such as talc, clay, calcium carbonate, and silica; carbon black, azo-based, phthalocyanine-based,
Examples include organic pigments such as quinacridone type, cochineal, and safflower pigments.

Further, in addition to this, in the dispersion type ink,
Polymeric substances that can function as dispersants or solubilizers for water-insoluble dyes can be used. Examples thereof include sorbitan fatty acid derivatives, sulfuric acid ester derivatives, polyoxyethylene alkylene ether type sulfuric acid esters, phosphoric acid ester derivatives, quaternary ammonium salt derivatives, polyoxyethylene alkyl ethers, polyoxyethylene alkyl esters. , Fatty acids, alkenyl succinates, higher alcohol sulfates,
A surfactant containing sodium alkylbenzene sulfonate, alkyl diphenyl ether disulfonates, naphthalene sulfonic acid formalin condensate or the like can be appropriately used.

In particular, when a pigment is used, if necessary, as a dispersant, for example, an anionic or nonionic surfactant, a polyphosphate dispersant, a formalin condensate of naphthalene sulfonate, a polyacrylic acid, Polystyrene sulfonic acid, styrene-acrylic acid copolymer, styrene-maleic acid copolymer, styrene-methacrylic acid copolymer, vinyl naphthalene-acrylic acid copolymer and other vinyl compounds and carboxylic acid-based resin, carboxymethyl cellulose, Resins such as polyvinyl alcohol, polyacrylic acid partial alkyl ester, and polyacrylic polyamine can be appropriately used.

In the dispersion type ink, after the pH of the mixture of the colorant and the dispersant or the solubilizer as described above is adjusted, a dispersion treatment such as a ball mill, a roll mill and a sand mill is carried out, or if necessary, a dispersion treatment. It can be obtained by preparing a dispersion liquid in advance by performing centrifugal treatment or filtration with a centrifuge and then adding additives such as a solvent, a surfactant and a zwitterionic compound.

The various inks used in the present invention prepared as described above are particularly excellent in affinity with a recording material having a high degree of size, high-speed recording property, optical density of recorded image,
Particularly excellent in color tone, water resistance, abrasion resistance or light resistance. In addition, storage stability, signal responsiveness, stability of droplet formation,
It is a practical ink with excellent ejection stability and continuous recording properties.

In addition to the various components described above, various additives may be used in the various inks used in the present invention for the purpose of further improving the physical properties of the ink. For example, p
Examples include H modifiers, drying inhibitors for crystalline organic compounds such as urea, viscosity modifiers, surface tension modifiers such as various surfactants, fungicides and bactericides. Alternatively, when a method of recording by charging and deflecting ink droplets is adopted, a specific resistance adjusting agent can be mentioned as an additive. The present invention prepares each color ink prepared to have desired physical property values having the above excellent properties, forms an ink set in which at least two different colors of ink are combined, and applies this to various inkjet recording systems. As a result, a high-density and high-quality image is formed. That is, in the present invention, the intended object is achieved by using two or more colors of ink having the physical properties described above and forming an image by an inkjet method.

As the ink jet method applied to the ink jet recording method of the present invention, any conventionally known method can be used. That is, various inkjet recording apparatuses other than the recording apparatus having the recording head of the type that generates droplets by utilizing the mechanical vibration of the piezoelectric vibrator are also preferably used. For example, it is preferably used for an apparatus or the like which applies a recording signal to the ink in the recording head in the form of thermal energy to generate droplets for recording. The black ink or color ink used in the present invention may be used as ink for writing instruments such as felt-tip pens and fountain pens.
However, when used as an ink for a writing instrument, it is necessary to adjust various properties such as viscosity and surface tension for the writing instrument.

Hereinafter, a recording apparatus applied to the present invention will be described, in which thermal energy corresponding to a recording signal is applied to the ink in the chamber of the recording head, and droplets are generated by the energy to perform recording. FIGS. 1, 2 and 3 show examples of the configuration of a head which is a main part of the apparatus.

The head 13 is a glass, ceramic or plastic plate having a groove 14 through which ink passes, and a heating head 15 (thin film head is shown in the figure, but not limited to this. It is obtained by bonding and. The heating head 15 includes a protective film 16 formed of silicon oxide or the like, aluminum electrodes 17-1 and 17-2, a heating resistor layer 1 formed of nichrome or the like.
8, heat storage layer 19, and substrate 2 having good heat dissipation properties such as alumina
Consists of zero.

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

FIG. 3 shows an external view of a multi-head in which a large number of the 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. 1 is a cross-sectional view of the head 13 along the ink flow path.
FIG. 2 is a sectional view taken along line AB in 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, an ink absorber 63 is provided adjacent to the blade 61 and 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 and dust from the ink ejection port surface. A recording head 65 having ejection energy generating means for ejecting ink to a recording material facing an ejection port surface provided with ejection ports to perform recording;
Reference numeral 6 denotes a carriage for mounting the recording head 65 and moving the same. The carriage 66 is slidably engaged with the guide shaft 67, and a part of the carriage 66 is connected to a belt 69 driven by a motor 68 (not shown). 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 section for inserting a recording material,
52 is a paper feed roller driven by a motor (not shown). With these configurations, the recording material is fed to the position facing the ejection port surface of the recording head 65, and is ejected to the ejection section provided with the ejection roller 53 as the recording progresses. In the above configuration, when the recording head 65 returns to the home position after recording is completed, the cap 6 of the ejection recovery unit 64 is
2 is retracted from the movement path of the recording head 65, but the blade 61 is projected in the movement path. 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.

[0050]

Next, the present invention will be described specifically with reference to examples and comparative examples. In addition, in the following description, a part or% indicates a weight ratio unless otherwise specified. Example 1 (first ink component) C.I. I. Direct Black 195 3 parts-Ethyl alcohol 1 part-Ethylene glycol 10 parts-Urea 5 parts-Dioctyl sodium sulfosuccinate 0.1 parts-Ion exchanged water 80.9 parts

(Second Ink Component) C.I. I. Basic Yellow 25 2.5 parts-Ethyl alcohol 1 part-Ethylene glycol 10 parts-Lauryl diaminoethylglycine sodium salt 2 parts-Ion-exchanged water 84.5 parts Each ink contains the above first and second ink components in a container. The mixture was sufficiently stirred in the solution, and pressure-filtered with a Teflon filter having a pore size of 0.45 μm to prepare the solution.

Example 2 (first ink component) C.I. I. Basic Red 92 2.5 parts-Ethyl alcohol 1 part-Ethylene glycol 10 parts-Urea 5 parts-Cetyltrimethylammonium chloride 0.1 part-Ion exchanged water 81.4 parts

(Second ink component) -1.2 parts of dye of the following structural formula a-1.3 parts of dye of the following structural formula b-ethyl alcohol 3 parts-ethylene glycol 10 parts-urea 5 parts-lauryl carboxymethyl Hydroxyethyl imidazolinium betaine 2 parts / ion-exchanged water 77.5 parts Each ink was sufficiently stirred with the above first and second ink components in a container, and filtered under pressure with a Teflon filter having a pore size of 0.45 μm. Prepared.

Example 3 (first ink component) C.I. I. Acid Blue 9 2 parts-Ethyl alcohol 2 parts-Diethylene glycol 5 parts-Polyethylene glycol (average molecular weight 400) 5 parts-Compound of the following structural formula A 1 part-Ion-exchanged water 85 parts The first ink contains the above components in a container. The mixture was sufficiently stirred in the solution, and pressure-filtered with a Teflon filter having a pore size of 0.45 μm to prepare the solution.

(Second Ink Component) <Dye Dispersion Component> C.I. I. Disperse Yellow 230 5 parts-Naphthalenesulfonic acid formamide condensate 10 parts <Ink components other than the dye dispersion> -Ethyl alcohol 5 parts-Diethylene glycol 10 parts-Urea 5 parts-Ion exchange water 65 parts The second ink is a dye After sufficiently stirring the components of the dispersion in a container and filling the zirconium beads with 50% by volume, the dispersion was dispersed for about 3 hours by a disperser, and then the pore size was 2.5 μm.
After removing coarse particles by pressure filtration with a Teflon filter, the ink components other than the dye dispersion are added, and the pH is adjusted to 7 to 9 with a pH adjuster such as sodium hydroxide and stirred, It was prepared by pressure filtration with a Teflon filter having a pore size of 1 μm.

Example 4 (first ink component) -Aizen Cathilon Black BXH (Hodogaya Kagaku) 3 parts-Ethyl alcohol 2 parts-Ethylene glycol 5 parts-Polyethylene glycol (average molecular weight 400) 5 parts-The following structural formula B Compound 1 part / ion-exchanged water 84 parts The first ink was prepared by thoroughly stirring the above components in a container and pressurizing and filtering with a Teflon filter having a pore size of 0.45 μm.

(Second Ink Component) <Dye Dispersion Component> C.I. I. Disperse Red 88 5 parts-Naphthalenesulfonic acid formamide condensate 10 parts <Ink components other than dye dispersion> -Ethyl alcohol 5 parts-Diethylene glycol 10 parts-Urea 5 parts-Ion-exchanged water 65 parts Second ink is dye dispersion After thoroughly stirring the components of the body in a container and filling the zirconium beads with 50% by volume conversion, dispersing with a disperser for about 3 hours, and then with a pore size of 2.5 μm.
Coarse particles are removed by pressure filtration with a Teflon filter, and ink components other than the dye dispersion are added, the pH is adjusted to 7 to 9 with a pH adjuster such as sodium hydroxide, and the mixture is stirred, then the pore size is adjusted. It was prepared by pressure filtration with a 1 μm Teflon filter.

Example 5 (First ink component) <Pigment dispersion component> Hostaperm Pink E (colorant, manufactured by Hoechst) 15 parts Styrene-acrylic acid-ethyl acrylate copolymer 0.7 parts (acid Value 174, average molecular weight 9,000) -Monoethanolamine 0.4 parts-Ethylene glycol 5 parts-Ion-exchanged water 78.9 parts

Of the above pigment dispersion components, the components except the colorant and ethyl alcohol are mixed in a container, heated at 70 ° C. in a water bath and stirred to completely dissolve the resin component. , Add colorant and ethyl alcohol 30
Mix and stir for 50 minutes, and convert zirconium beads to 50% by volume.
After filling, the mixture was dispersed by a disperser for about 3 hours, then subjected to centrifugal separation treatment to remove coarse particles, and then a solvent and other additives were added and mixed, followed by stirring for 1 hour to prepare a pigment dispersion. <Ink component including pigment dispersion> 40 parts of the above pigment dispersion, 10 parts of glycerin, 10 parts of ethylene glycol, 1 part of ethanol, 0.2 parts of sodium polyethylene lauryl sulfate, 38.8 parts of deionized water Mix the components Then, the pigment ink was prepared by stirring for 1 hour.

(Second Ink Component) C.I. I. Basic Yellow 25 2.5 parts-Ethyl alcohol 1 part-Ethylene glycol 10 parts-Lauryl betaine 2 parts-Ion-exchanged water 84.5 parts The second ink was prepared by thoroughly agitating the above components in a container to obtain a pore size of 0. It was prepared by pressure filtration with a 45 μm Teflon filter.

Comparative Example 1 (first ink component) C.I. I. Direct Black 195 3 parts-Ethyl alcohol 1 part-Ethylene glycol 10 parts-Urea 5 parts-Ion-exchanged water 81 parts (second ink component) -C.I. I. Basic Yellow 25 2.5 parts-Ethyl alcohol 1 part-Ethylene glycol 10 parts-Ion-exchanged water 86.5 parts Each ink was prepared by thoroughly stirring the above-mentioned first and second ink components in a container to obtain a pore size of 0. It was prepared by pressure filtration with a 45 μm Teflon filter.

However, the above structural formulas A, B, a and b are
It is shown below. Compound of structural formula A C ₂₅ H ₅₁ NH (C ₂ H ₄ NH) ₃ CH ₂ SO ₃ Li Compound of structural formula B C ₁₅ H ₃₁ NH (C ₂ H ₄ NH) ₂ C ₂ H ₄ COONH ₄

Dye of structural formula a

Dye of structural formula b

[Evaluation Method] Using each of the inks of Examples 1 to 5 and Comparative Example 1 described above, printing was performed on woodfree paper including the following commercially available copy paper.・ Canon copy paper: PB PAPER ・ Xerox: 4024 PAPER ・ FOX RIVER: PLOVER BOND PAPER

Printed Image Quality As shown in FIG. 5, the printed image is printed in a 1 cm square,
The quality of the bleeding image between the two colors was evaluated by the following evaluation criteria by dividing the image into 5 × 5 cells and printing solid images alternately with the two colors. Table 1 shows the results. (Evaluation Criteria) O: The boundary line between the two colors is clear, and no bleeding or color mixture is seen at the boundary. Δ: It is clear that there is a boundary line between the two colors,
Some bleeding and color mixing are seen at the boundary. X: The boundary line between the two colors is indistinguishable.

Character Quality Next, the single-color character quality and mixed-color character quality were evaluated.
The characters were composed of 1500 alphanumeric and Chinese characters on A4 size high-quality paper, and the printing ratio was 100% for a single color and 200% for a mixed color of two colors. The evaluation criteria are as follows. Table 1 shows the results. (Evaluation Criteria) ◯: The edges of characters are clear and feathering and line thickening due to bleeding are not seen. Δ: The edges of the characters are slightly blurred and a uniform line thickening is observed. ×: Feathering is noticeable due to blurred edges of characters, and uneven line thickening is observed.

[Evaluator] As the ink jet recording apparatus used, the same recording apparatus as shown in FIG. 4 was used, and a color image was formed using the four heads shown in FIG. The recording head used here is BJC820.
The same recording head as that used in (trade name, inkjet printer manufactured by Canon Inc.) was used. The drive conditions for the recording heads, that is, the conditions for energizing the heater were such that the applied voltage was 28 V, the pulse width was 3.2 μsec, and the drive frequency was 5 kHz for each head.

Table 1: Evaluation results

[0070]

As described above, according to the present invention,
With respect to the same recording material, it is possible to obtain a high-quality color image with clear character quality without bleeding at the boundary between two different colors.

[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 an image quality evaluation pattern.

[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 Droplet 25: Recording material 26: Multi-groove 27: Glass plate 28: Heating head 51: Paper feeding part 52: Paper feeding roller 53: Paper discharging roller 61: Blade 62: Cap 63: Ink absorber 64: Ejection recovery part 65 : Recording head 66: Carriage 67: Guide shaft 68: Motor 69: Belt

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Eriko Saito 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (19)

[Claims] 1. An ink set combining two or more different colors of ink used when a color image is recorded on a recording material by an inkjet recording method, wherein the ink contains a coloring material and a liquid medium as essential components, An ink set comprising at least one color ink containing an anionic or cationic surfactant, and an ink having a different color from the ink containing a zwitterionic compound. 2. A color constituting an ink of a color different from that of the ink, wherein the coloring material constituting the ink of at least one color is an anionic dye, and the ink contains an anionic surfactant at the same time. The ink set according to claim 1, wherein the material is a cationic dye and further contains a zwitterionic compound. 3. A color forming an ink of a color different from that of the ink, wherein the coloring material forming the ink of at least one color is a cationic dye and the ink contains a cationic surfactant at the same time. The ink set according to claim 1, wherein the material is an anionic dye and further contains a zwitterionic compound. 4. A coloring material constituting at least one color ink is a pigment, and the ink contains a cationic surfactant at the same time, and the coloring material constituting an ink of a color different from that of the ink. The ink set according to claim 1, wherein the ink set is an anionic dye and further contains a zwitterionic compound. 5. A coloring material constituting at least one color ink is a pigment, and the ink also contains an anionic surfactant at the same time, and a coloring material constituting an ink of a different color from the ink. The ink set according to claim 1, which is a cationic dye and further contains a zwitterionic compound. 6. The zwitterionic compound is an amphoteric surfactant or a compound represented by the following general formula (I).
Ink set described in. (In the formula, R ₁ represents an alkyl group having 1 to 48 carbon atoms or a hydrogen atom, R ₂ represents (CH ₂ ) _a —X ₁ or a hydrogen atom,
a is an integer of 1 to 4. R ₃ is (CH ₂ ) _b
Represents -X ₂ or R ₄ -Y or a hydrogen atom, and b is an integer of 1 to 4. R ₄ represents an alkyl group having 1 to 48 carbon atoms or a hydrogen atom. Z is (NR _{5 Cl (El)} H _{2l (El)} )
_c (NHC _n H _2n ) _d , 1 (el) and n are 2 to 4
, And c + d is an integer of 0 to 50. Y is _{(NR 6 C m H 2m)} e (NHC p H 2P) represents _f, m and p are 2-4 any integer, e + f is 0
It shall be an integer of 50. R ₅ represents _{(CH 2) g -X 3,} g is an integer of 1-4. R ₆ is (C
H ₂₎ represents the _h -X _4, h is an integer of 1-4. X ₁ , X ₂ , X ₃ and X ₄ are each a carboxyl group,
It is selected from the group consisting of a carboxyl group salt, a sulfone group, a sulfone group salt or a hydrogen atom. Further, when R ₂ and R ₃ are each a hydrogen atom, both c and e are not 0, and X ₁ , X ₂ , X ₃ and X ₄ are not all hydrogen atoms. ) 7. An ink jet recording method for recording a color image on a recording material by an ink jet recording method by combining two or more color inks, wherein the ink set according to any one of claims 1 to 6 is used. Recording method. 8. A recording method of an ink jet recording apparatus,
The inkjet recording method according to claim 7, which is an inkjet recording method using heat energy. 9. A recording unit comprising an ink containing portion containing ink and a head portion for ejecting the ink as ink droplets, wherein the ink is the ink set according to any one of claims 1 to 6. And a recording unit. 10. The recording unit according to claim 9, wherein the head portion is a head which causes thermal energy to act on the ink to eject ink droplets. 11. The unit according to claim 9, wherein the ink containing portion is formed of polyurethane, cellulose, or polyvinyl acetate. 12. An ink cartridge comprising an ink containing portion containing ink, wherein the ink is
<6> An ink cartridge, which is the ink set described in <6>. 13. The ink cartridge according to claim 12, wherein the ink containing portion has a liquid contact surface formed of polyolefin. 14. An ink set according to any one of claims 1 to 6, wherein the ink is an ink jet recording apparatus including a recording unit having an ink containing section containing ink and a head section for ejecting the ink as ink droplets. An inkjet recording apparatus characterized by the following. 15. A head for discharging ink droplets by applying thermal energy to ink.
3. The ink jet recording apparatus according to claim 1. 16. The ink jet recording apparatus according to claim 14, wherein the ink containing portion is formed of polyurethane, cellulose or polyvinyl acetate. 17. An ink jet recording apparatus comprising a recording head for ejecting ink droplets, an ink cartridge having an ink accommodating portion for accommodating ink, and an ink supply portion for supplying ink from the ink cartridge to the recording head. An ink jet recording apparatus, wherein the ink is the ink set according to claim 1. 18. The ink jet recording apparatus according to claim 17, wherein the recording head is a head that causes thermal energy to act on ink to eject ink droplets. 19. The ink jet recording apparatus according to claim 17, wherein the ink containing portion has a liquid contact surface formed of polyolefin.