JP2000169770A - Ink set and ink jet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink set for ink jet recording capable of giving a full color image having clarity and high definition and excellent in image preservation stability such as water resistance, light resistance and the like as well as in image fixability and to provide an ink jet recording method using the same. SOLUTION: In the ink set containing a cyan ink, a magenta ink, a yellow ink and a black ink, one or two out of the cyan ink, the magenta ink and the yellow ink are ones containing, as essential ingredients, a water-soluble coloring material and water, and the rest and the black ink contain, as essential ingredients, a water-insoluble coloring material and water. The yellow ink is one containing, as essential ingredients, a water-soluble coloring material and water. Ink jet recording is carried out using the ink set.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel ink set used in an ink jet recording apparatus and an ink jet recording method.

[0002]

2. Description of the Related Art The ink jet recording method is a method of discharging a liquid or a molten solid ink from a nozzle, a slit, a porous film, or the like, and recording on paper, cloth, film, or the like. Above all, the so-called piezo ink jet recording system using a piezoelectric element, or the so-called thermal ink jet recording system in which droplets are formed by applying thermal energy to perform recording, have many advantages such as high-speed printing and high resolution. have. Ink jet recording apparatuses used for the ink jet recording method have various advantages such as small size, low cost, and quietness, and are often commercially available as black single-color or full-color printers.

A full-color ink set for ink-jet recording used in an ink-jet recording apparatus for forming a full-color image has many required characteristics, but the following points are particularly important. 1) A sharp and high-definition image can be obtained on any paper or film. 2) Good storage stability of the image, especially good water fastness and light fastness. 3) A good image can be obtained even after storing the ink for a long time.
4) The image fixability is excellent.

In order to satisfy these characteristics, many proposals have been made and implemented. Conventionally,
In particular, a water-soluble dye is usually used as a coloring material for an ink jet recording apparatus used in an office or the like. These have excellent coloring properties even on plain paper, and although clear images can be obtained, the water resistance and light resistance of the images are inferior. On the other hand, an ink using a pigment as a coloring material, which aims at improving water resistance and light resistance, can achieve its purpose, is very promising, and has been proposed and put to practical use.

[0005] For example, US Pat. No. 5,085,698 proposes to use AB or BAB block copolymer as a dispersant. US Patent 517
No. 2133 proposes to use a specific pigment, a water-soluble resin, and a solvent.

[0006]

According to the above-mentioned proposed technique, an image having almost perfect water fastness and light fastness can be obtained. However, when a pigment is used for a color ink,
Compared to the case where an image was formed with an ink using a dye,
Natural gradation is difficult to reproduce, and the color development of secondary colors such as green and red is inferior. Further, there has been a problem that, on so-called plain paper such as copy paper, the fixability of a color image portion in which a plurality of inks are reproduced in a superimposed manner is extremely poor. That is, there has not yet been an ink set capable of obtaining a clear and high-definition full-color image on any paper or film and forming an image having excellent water resistance and light resistance.

Accordingly, the present invention is to solve such a problem of the prior art, and to provide an ink set satisfying all the above-mentioned requirements 1) to 4) and an ink jet recording method using the same. Is the subject. That is, an object of the present invention is to obtain a clear, high-definition full-color image on any paper or film, and have image storage stability such as water fastness and light fastness. A recording ink set,
An object of the present invention is to provide an ink jet recording method using the same.

[0008]

As a result of intensive studies, the present inventors have found that one or two of cyan, magenta, and yellow inks are used in an ink jet recording ink set including cyan, magenta, yellow, and black. The seed is an ink containing water-soluble coloring material and water as essential components,
Only when the remaining ink and the black ink were inks containing water-insoluble colorants and water as essential components, it was found that all of the above required characteristics could be satisfied, and the present invention was completed.

That is, according to the present invention, in an ink set including a cyan ink, a magenta ink, a yellow ink and a black ink, one or two of the cyan ink, the magenta ink and the yellow ink contain a water-soluble coloring material and water. An ink set as an essential component, the remaining ink and black ink are an ink set characterized by being an ink having a water-insoluble colorant and water as essential components, a yellow ink,
The ink set, wherein the water-soluble colorant and water are essential components, and the ink set, wherein the water-soluble colorant is a dye, the dye is a direct dye and an acid dye. The ink set, characterized in that it is at least one selected from the group consisting of: a water-insoluble colorant, a pigment, wherein the primary particle diameter of the pigment is 10 to 100 nm; The ink set, wherein the volume average particle diameter is 20 to 150 nm in the ink, wherein the solubility of the dye contained in the yellow ink in water is 15% by weight or less at 20 ° C. The dye contained in the set and the yellow ink is CI Direct Yellow 86, 13
2, 142, 144 or 173, wherein the ink set has a surface tension at 20 ° C. of 20 to 65 mN /
m, and the viscosity is 1.5 to 5 mPas, wherein the ink set, an ink jet recording method using the ink set, and a thermal ink jet method, An ink jet recording method for adhering a reaction liquid containing a reactant to a recording medium and an ink composition, wherein the ink set is used as the ink composition, and the reactant is an electrolyte or a cation. The ink-jet recording method, wherein the ink-jet recording method is characterized in that the ink-jet recording method is an active substance.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The ink set of the present invention includes a cyan ink, a magenta ink, a yellow ink, and a black ink, and one or two of the cyan ink, the magenta ink, and the yellow ink include a water-soluble coloring material and water as essential components. And the remaining ink and black ink are inks containing water-insoluble colorants and water as essential components. In particular, one of the yellow ink, the cyan ink and the magenta ink is an ink containing a water-soluble coloring material and water as essential components, and the remaining ink and the black ink are inks containing a water-insoluble coloring material and water as essential components. Preferably, only the yellow ink is an ink containing a water-soluble coloring material and water as essential components, and the remaining ink and the black ink are more preferably inks containing a water-insoluble coloring material and water as essential components. That is, (1) a yellow ink containing a water-soluble coloring material and water as essential components,
(2) A combination of a water-insoluble colorant with a black ink, a cyan ink and a magenta ink containing water as an essential component is particularly preferable to achieve the above object of the present invention.

First, a description will be given of a case where the ink constituting the ink set of the present invention contains a water-insoluble coloring material and water as essential components. Examples of the water-insoluble coloring material in the black ink that can be used in the present invention include carbon black, inorganic pigments, organic pigments, oil-based dyes, and disperse dyes, but carbon black is preferred in terms of ease of handling.

Examples of the carbon black include furnace black, lamp black, acetylene black, channel black and the like. For example, Raven 700
0, Raven5750, Raven5250, Rav
en5000 ULTRAII, Raven3500, Raven200
0, Raven 1500, Raven 1250, Rav
en1200, Raven1190 ULTRAII, Raven1170, Raven125
5, Raven 1080, Raven 1060 (or more,
Manufactured by Columbian Carbon Co., Ltd.), Regal400R,
Regal 330R, Regal 660R, Mogul L, Black Pearls L, Monarch 700, Monarch 800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300, Monarch 1300, Monarch 1300, Monk 1100, Monk 1100 Color Black FW2V, Color Black 18, Color Black FW200, Color Black S150, Color Black S160, Color Black S170, Printex35, PrintexU, Printex Vritex140U, PrintexV
No. 25, N, Special Black 6, Special Black 5, Special Black 4A, Special Black 4 (all manufactured by Degussa)
o.33, No.40, No.47, No.52, No.9
00, No. 2300, MCF-88, MA600, M
A7, MA8, MA100 (all manufactured by Mitsubishi Chemical Corporation) and the like can be used, but are not limited thereto. Further, magnetic fine particles such as magnetite and ferrite, titanium black and the like may be used as a black pigment.

When the cyan ink contains a water-insoluble colorant and water as essential components, a pigment is preferably used as the water-insoluble colorant, for example, CI Pigme.
ntBlue-1, -2, -3, -15, -15: 1,
-15: 3, C.I.-15: 34, -16, -22,-
60 and the like, but are not limited thereto.

When the magenta ink contains a water-insoluble colorant and water as essential components, a pigment is preferably used as the water-insoluble colorant, for example, CI Pigment.
tRed 5, 7, 12, 48, 48: 1, 57, 112, 12
2, 123, 146, 168, 184, 202, etc., but are not limited thereto.

When the yellow ink contains a water-insoluble colorant and water as essential components, a pigment is preferably used as the water-insoluble colorant. For example, CI Pigme
ntYellow-1, -2, -3, -12, -13,
-14, -16, -17, -73, -74, -75,-
83, -93, -95, -97, -98, -114,-
128, -129, -151, -154 and the like.

As the pigment, a pigment newly synthesized for the present invention may be used. Further, the surface treatment of the pigment can be performed in advance. For example, by surface treatment with alcohols such as ethanol and methanol, surfactant treatment, pigment derivative treatment for substituting acidic groups and basic groups, pigment coating reaction treatment for coating the pigment surface with other substances, condensation reaction and graft reaction Surface chemical reaction treatment for introducing a substituent, coupling reaction treatment for surface treatment with a silane coupling agent, aluminate coupling agent, or the like, plasma reaction treatment, CVD treatment, or the like can be performed. The surface-treated pigment can also be obtained as a commercial product. As a commercial product, for example, Cabojet 300
(Manufactured by Cabot Corporation) and Microjet CW-1 (manufactured by Orient Chemical Co., Ltd.).

The primary particle size of these pigments is 10 to 10
The thickness is preferably 0 nm, more preferably 15 to 80 nm. Although there are various methods for measuring the primary particle diameter, measurement by observation with an electron microscope is the easiest. When the primary particle diameter of the pigment is less than 10 nm,
The coloring power tends to be insufficient, and if it exceeds 100 nm,
In some cases, dispersion stability is likely to decrease. Further, the volume average particle diameter of the pigment in the ink is preferably 20 to 150 nm, more preferably 30 to 120 nm.
The volume average particle diameter in the ink is, for example, Microtra
It can be easily measured by using UPA 9340 manufactured by Company c. In this method, the measurement can be performed without diluting the ink, but the measurement can also be performed by diluting the ink as necessary. The parameter given in this measurement is viscosity, but in this specification, the viscosity of the measured object was used as it is. The volume average particle diameter of the pigment is 20 nm in the ink.
If it is less, the coloring power on paper tends to be insufficient,
On the other hand, if it exceeds 150 nm, a precipitate is likely to be generated, and the long-term storage stability may decrease.

The coloring materials used in the present invention include:
Although those having a low content of organic and inorganic impurities are preferred, commercially available water-insoluble colorants generally have a high content of impurities, and thus it is desirable to use purified products. The removal of impurities can be performed by, for example, a method of washing with water, an ultrafiltration membrane method, an ion exchange treatment, adsorption with activated carbon, zeolite, or the like. Although not particularly limited, the concentration of the inorganic substance derived from impurities of the coloring material in the ink is preferably 500 ppm or less, more preferably 300 ppm or less.

The water-insoluble colorant used for each ink in the ink set of the present invention is preferably 0.5 to 20% by weight, and more preferably 2 to 10% by weight based on the weight of the ink.
More preferably, it is% by weight. The water-insoluble coloring material used in the present invention may be dispersed using a dispersant. As the dispersant, a polymer dispersant, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant, or the like can be used. Further, since a dispersant having a small amount of impurities is more preferable, it is preferable to use a dispersant prepared in a clean environment.

As the polymer dispersant, any polymer having a hydrophilic structure portion and a hydrophobic structure portion can be effectively used. As the polymer having a hydrophilic structure portion and a hydrophobic structure portion, a condensation polymer and an addition polymer can be used. Examples of the condensation polymer include known polyester dispersants. Examples of the addition polymer include an addition polymer of a monomer having an α, β-ethylenically unsaturated group. By appropriately combining and copolymerizing a monomer having an α, β-ethylenically unsaturated group having a hydrophilic group and a monomer having an α, β-ethylenically unsaturated group having a hydrophobic group, a desired polymer dispersant is obtained. can get. Further, a homopolymer of a monomer having an α, β-ethylenically unsaturated group having a hydrophilic group can also be used.

Examples of the monomer having an α, β-ethylenically unsaturated group having a hydrophilic group include monomers having a carboxyl group, a sulfonic acid group, a hydroxyl group, a phosphoric acid group and the like, for example, acrylic acid, methacrylic acid, crotonic acid, Itaconic acid, itaconic acid monoester, maleic acid, maleic acid monoester, fumaric acid, fumaric acid monoester, vinyl sulfonic acid, styrene sulfonic acid, sulfonated vinyl naphthalene, vinyl alcohol, acrylamide, methacryloxyethyl phosphate, bismethacryloxy Ethyl phosphate, methacryloxyethyl phenyl acid phosphate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate and the like can be mentioned.

Examples of monomers having an α, β-ethylenically unsaturated group having a hydrophobic group include styrene derivatives such as styrene, α-methylstyrene and vinyltoluene, vinylcyclohexane, vinylnaphthalene, vinylnaphthalene derivatives, and alkyl acrylates. Alkyl methacrylate, phenyl methacrylate, cycloalkyl methacrylate, alkyl crotonate, dialkyl itaconate, dialkyl maleate and the like.

Examples of preferred copolymers include styrene-styrene sulfonic acid copolymer, styrene-maleic acid copolymer, styrene-methacrylic acid copolymer, styrene-acrylic acid copolymer, and vinylnaphthalene-maleic acid. Copolymer, vinyl naphthalene-methacrylic acid copolymer,
Vinyl naphthalene-acrylic acid copolymer, acrylic acid alkyl ester-acrylic acid copolymer, methacrylic acid alkyl ester-methacrylic acid, styrene-methacrylic acid alkyl ester-methacrylic acid copolymer, styrene-acrylic acid alkyl ester-acrylic acid Copolymer,
Examples include styrene-phenyl methacrylate-methacrylate copolymer, styrene-cyclohexyl methacrylate-methacrylate copolymer, and the like. In addition, those obtained by appropriately copolymerizing a monomer having a polyoxyethylene group and a hydroxyl group with these polymers may be used. Also, increase the affinity with the pigment having an acidic functional group on the surface,
In order to improve dispersion stability, a monomer having a cationic functional group, for example, N, N-dimethylaminoethyl methacrylate, N, N-dimethylaminoethyl acrylate, N, N-dimethylaminomethacrylamide,
N, N-dimethylaminoacrylamide, N-vinylpyrrole, N-vinylpyridine, N-vinylpyrrolidone,
N-vinyl imidazole or the like may be appropriately copolymerized.

The copolymer may have any structure such as random, block and graft copolymers. Further, any polymer dispersant may have a relatively low molecular weight, but the weight average molecular weight is most effective when the molecular weight is 1,000 to 10,000, more preferably 2,000 to 9000, and more preferably 2,500 to 8,000. Are more preferred.

Examples of the dispersant include polystyrene sulfonic acid, polyacrylic acid, polymethacrylic acid, polyvinyl sulfonic acid, polyalginic acid, polyoxyethylene-polyoxypropylene-polyoxyethylene block copolymer, formalin condensate of naphthalene sulfonic acid, Cellulose derivatives such as polyvinylpyrrolidone, polyethyleneimine, polyamines, polyamides, polyvinylimidazoline, aminoalkyl acrylate / acrylamide copolymer, chitosan, polyoxyethylene fatty acid amide, polyvinyl alcohol, polyacrylamide, carboxymethyl cellulose, carboxyethyl cellulose, and polysaccharides And its derivatives can also be used.

Although not particularly limited, in a polymer dispersant having an acidic group as a free radical, the acidic group is preferably a carboxylic acid or a sulfonic acid, but both may be used in combination. This is because carboxylic acids and sulfonic acids are easily dissociated, and a high surface charge density can be obtained by appropriately adjusting the pH. In addition,
Among carboxylic acids and sulfonic acids, carboxylic acids are more preferred. This is because using carboxylic acid as an acidic group,
The cohesiveness of the coloring material on the recording material is moderate,
This is because a product excellent in printing quality such as fixability can be obtained.

Of these polymers, those having an acid as a hydrophilic group are preferably used in the form of a salt with a basic compound in order to enhance water solubility. Compounds that form salts with these polymers include sodium, potassium, lithium and other alkali metals, monomethylamine,
Aliphatic amines such as dimethylamine and triethylamine, alcohol amines such as monomethanolamine, monoethanolamine, diethanolamine, triethanolamine and diisopropanolamine, and ammonia can be used. Among these, a basic compound of an alkali metal such as sodium, potassium and lithium is preferably used. This is because a basic compound of an alkali metal is a strong electrolyte and has a large effect of promoting the dissociation of an acid.

These dispersants may be used alone or in combination of two or more. Since the amount of the dispersant varies greatly depending on the coloring material, it cannot be determined unconditionally. However, generally, the total amount of the dispersing agent is 0.1 to 100% by weight, preferably 1% by weight, based on the coloring material.
-50% by weight, more preferably 3-20% by weight.

As a method for preparing an ink containing a water-insoluble colorant as an essential component, for example, a predetermined amount of a pigment is added to an aqueous solution containing a predetermined amount of a dispersant, the mixture is sufficiently stirred, and then a dispersion machine is used. After dispersing and removing coarse particles by centrifugation or the like, a predetermined solvent, additive, and the like are added, and the mixture is stirred, mixed, and filtered to obtain an ink. Any commercially available disperser may be used. For example, colloid mill, flow jet mill, slasher mill, high speed disperser, ball mill, attritor, sand mill, sand grinder, ultra fine mill, Eiger motor mill, dyno mill, pearl mill, agitator mill, kobol mill, three rolls, two rolls Rolls, extruders, kneaders, microfluidizers, optimizers, laboratory homogenizers, ultrasonic homogenizers, accumulators and the like can be used alone or in combination. As another method for producing an ink, after mixing a predetermined solvent, adding a predetermined amount of a dispersant, adding a pigment, and then dispersing using a disperser.

A treatment with a coloring material having an acidic group such as a carboxylic acid or a sulfonic acid directly on the surface, a treatment with a coupling agent such as an alcohol, an acid, a base, or a silane compound, a polymer grafting treatment, a plasma treatment, or the like. When using the applied coloring material, these dispersants may not be used. As the water, pure water, ultrapure water, distilled water, ion-exchanged water, or the like can be used.

Next, a description will be given of a case where the ink constituting the ink set of the present invention contains a water-soluble coloring material and water as essential components. The yellow ink is particularly preferably an ink containing a water-soluble coloring material and water as essential components, and in that case, the water-soluble coloring material is preferably a dye. Among them, direct dyes or acid dyes that can provide vivid colors are preferable. Specific examples of such dyes include CI Direct Yellow 1, 2, 4, 8, 11, 12, 24, 2
6, 27, 28, 33, 34, 39, 41, 42, 4
4, 48, 50, 51, 58, 72, 85, 86, 8
7, 88, 98, 100, 110, 127, 135, 1
41, 142, 144, 173, CI Acid Yellow 1, 3, 4, 7, 11, 12, 13, 14, 17, 1
8, 19, 23, 25, 29, 34, 36, 38, 4
0, 41, 42, 44, 49, 53, 55, 59, 6
1, 71, 72, 76, 78, 79, 99, 111, 1
14, 116, 122, 135, 142, 161, 17
2, CI Food Yellow 3, 4, 5 and the like.

These yellow dyes preferably have a solubility in water of 15% by weight or less at 20 ° C. in order to obtain water resistance in a yellow image. These dyes may be used alone or as a mixture of two or more. Even in the case of mixing, it is desirable that the solubility of the mixed dye in water at 20 ° C. is 15% by weight or less. If the solubility of the yellow dye in water exceeds 15% by weight at 20 ° C., the water resistance on paper tends to be insufficient.

The solubility referred to in the present specification is measured as follows. That is, for 100 g of ultrapure water controlled at 20 ° C., the dye concentrations were 1, 2,
3,. . . . . After stirring for 1 hour each aqueous solution of various concentrations prepared so as to be in increments of 1% by weight and 1% by weight, the solution was passed through a 0.2 μm filter, and the maximum concentration at which no insoluble dye was observed on the filter (weight %) Is the solubility of the dye.

The solubility in water is 1 at 20 ° C.
Examples of the water-soluble dye of 5% by weight or less include CI Direct Yellow 86, 132, 142 and
144, 173 and the like, and these dyes are particularly preferred.

The yellow dye is based on the weight of the ink.
0.05 to 10% by weight, preferably 0.1 to 5% by weight.
More preferably, it is% by weight. If the content exceeds 10% by weight, clogging at the tip of the print head is liable to occur. If the content is less than 0.05% by weight, sufficient image density cannot be obtained, which is not preferable.

When the cyan ink is an ink containing water-soluble coloring material and water as essential components, the water-soluble coloring material is preferably a dye. Examples of cyan dyes include CI Direct Blue-1, -2, -6, -8, -22, and -3.
4, -70, -71, -76, -78, -86, -14
2, -199, -200, -201, -202, -20
3, -207, -218, -236 and -287, C.I.
I. Acid Blue-1, -7, -9, -15, -2
2, -23, -27, -29, -40, -43, -5
5, -59, -62, -78, -80, -81, -9
0, -102, -104, -111, -185 and -2
54 and the like.

The cyan dye may be used alone or in combination of two or more. Also, the content of cyan dye,
The total amount is preferably from 0.1 to 10% by weight, more preferably from 0.5 to 8% by weight, and particularly preferably from 0.8 to 6% by weight, based on the weight of the ink. If the content exceeds 10% by weight, clogging at the tip of the print head tends to occur, and if it is less than 0.1% by weight, sufficient image density cannot be obtained, which is not preferable.

When the magenta ink is an ink containing water-soluble coloring material and water as essential components, the water-soluble coloring material is preferably a dye. Examples of magenta dyes include CI.
Direct Red-1, -2, -4, -8, -9, -1
1, -13, -20, -28, -31, -33, -3
7, -39, -51, -59, -62, -63, -7
3, -76, -80, -81, -83, -87, -9
0, -94, -96, -99, -101, -110 and -189, CI Acid Red-1, -4, -8,-
13, -14, -15, -18, -21, -26, -3
5, -37, -249 and -257.

The magenta dye may be used alone or as a mixture of two or more. The content of the magenta dye is preferably from 0.1 to 10% by weight, more preferably from 0.5 to 8% by weight, and more preferably from 0.8 to 6% by weight, based on the weight of the ink. Is particularly preferred. If the content exceeds 10% by weight, clogging at the tip of the print head tends to occur, and if it is less than 0.1% by weight, sufficient image density cannot be obtained, which is not preferable.

In the ink constituting the ink set of the present invention, the ink may contain a water-soluble coloring material and water as essential components, or may contain a water-insoluble coloring material and water as essential components.
It is preferable to add a water-soluble organic solvent. Known water-soluble organic solvents can be used, for example, ethylene glycol, diethylene glycol, propylene glycol, polypropylene glycol, butylene glycol, triethylene glycol, 1,5-pentanediol, 1,2,6-hexane. Polyhydric alcohols such as triol and glycerin, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, etc. A polyhydric alcohol derivative, pyrrolidone, N-methyl-2-pyrrolidone,
Cyclohexylpyrrolidone, nitrogen-containing solvents such as triethanolamine, ethanol, isopropyl alcohol, butyl alcohol, alcohols such as benzyl alcohol, or, thiodiethanol, thiodiglycerol, sulfolane, sulfur-containing solvents such as dimethyl sulfoxide, propylene carbonate, Ethylene carbonate or the like can be used.

A surfactant may be added to the ink constituting the ink set of the present invention in order to adjust the surface tension. As the surfactant, a nonionic or anionic surfactant which hardly affects the dispersion state of the water-insoluble colorant and the dissolution state of the water-soluble dye is preferable.

Examples of the nonionic surfactant include polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, and polyoxyethylene nonyl surfactant. Examples include oxyethylene sorbitan fatty acid ester, fatty acid alkylolamide, acetylene alcohol ethylene oxide adduct, polyethylene glycol polypropylene glycol block copolymer, polyoxyethylene ether of glycerin ester, polyoxyethylene ether of sorbitol ester, and the like.

Examples of the anionic surfactant include alkyl benzene sulfonate, alkyl phenyl sulfonate,
Alkyl naphthalene sulfonates, higher fatty acid salts, sulfate salts and sulfonates of higher fatty acid esters, higher alkyl sulfosuccinates and the like can be mentioned. Examples of the amphoteric surfactant include betaine, sulfobetaine, sulfate betaine, and imidazoline.

In addition, use of silicone surfactants such as polysiloxane polyoxyethylene adducts, fluorine surfactants such as oxyethylene perfluoroalkyl ether, and biosurfactants such as spiculisporic acid, rhamnolipid, and lysolecithin may be used. Can also.

In addition, the inks constituting the ink set of the present invention include cellulose derivatives such as polyethyleneimine, polyamines, polyvinylpyrrolidone, polyethyleneglycol, ethylcellulose, carboxyethylcellulose, polysaccharides and the like for controlling the properties of the ink. Derivatives, other water-soluble polymers and polymer emulsions, cyclodextrins, macrocyclic amines, dendrimers, crown ethers, urea and its derivatives,
Acetamide and the like can be added. Further, if necessary, an antioxidant, a fungicide, a conductive agent, an antioxidant, an ultraviolet absorber, a chelating agent, a viscosity modifier and the like can be added.

As the chelating agent, ethylenediaminetetraacetic acid (EDTA), iminodiacetic acid (IDA), ethylenediaminedi (o-hydroxyphenylacetic acid)
(EDDHA), nitrilotriacetic acid (NTA), dihydroxyethylglycine (DHEG), trans-1,2-
Cyclohexanediaminetetraacetic acid (CyDTA), diethylenetriamine-N, N, N ', N', N'-pentaacetic acid (D
TPA), glycol ether diamine-N, N,
N ′, N′-tetraacetic acid (GEDTA) or the like can be used.

As the viscosity modifier, methyl cellulose,
It is also useful to add polysaccharides and derivatives thereof in addition to ethylcellulose and its derivatives, glycerin and polyglycerin and their polyethylene oxide and polypropylene oxide adducts. For example, glucose, fructose, mannitol, D-sorbitol, dextran, xanthan gum, curdlan, cycloamylose, maltitol and derivatives thereof can be used.

The viscosity of the ink is the same for all color inks, and is 1.5 to 5.0 mPas at 20 ° C., particularly 1.6 to 4.5 mPas.
At 0 mPas, the best results are obtained. 1.
If it is lower than 5 mPas, it is difficult to obtain ejection stability, and
If it is higher than Pas, clogging tends to occur, which is not preferable.

The pH of the ink constituting the ink set of the present invention can be adjusted as required.
Inks containing pigments and inks containing dyes having a high pH are suitable for improving the solubility of dyes. However, if the pH exceeds 12, adverse effects such as corrosion, dissolution, and peeling of the head material appear, so
The range of 7.5 to 11 is preferred. For adjusting the pH, for example, potassium hydroxide, sodium hydroxide, lithium hydroxide, ammonium hydroxide, triethanolamine, diethanolamine, ethanolamine, 2-amino-2-methyl-1-propanol, ammonia, ammonium phosphate, Potassium phosphate, sodium phosphate, lithium phosphate, sodium sulfate, acetate, lactate, benzoate, acetic acid, hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, propionic acid, P-toluenesulfonic acid and the like, General pH buffers can also be used.

The surface tension of each color ink constituting the ink set of the present invention at 20 ° C. is desirably 20 to 65 mN / m, preferably 25 to 60 mN / m. 20
If it is lower than mN / m, bleeding on paper becomes remarkable, and stable ejection is difficult to obtain, which is not preferable. If it is larger than 65 mN / m, the ink does not sufficiently penetrate into the paper, which is not preferable. At least cyan, magenta and yellow are blue,
In order to improve the color developability of secondary colors such as red and green, or to prevent bleeding between different colors, the ink has a surface tension of 20 to 50 mN / m at 20 ° C., preferably 25 to 50 mN / m.
It is desirable to be 45 mN / m, more preferably 30 to 40 mN / m. Adjustment of the surface tension of the ink may be performed using only the above-mentioned surfactant or by using a water-soluble organic solvent having a surface tension of less than 50 mN / m among the above-mentioned organic solvents.

In the ink set of the present invention, good printing quality can be obtained in any of the methods by using an ink jet recording apparatus. For example, in a recording method of performing recording by discharging ink droplets from an orifice according to a recording signal, the ink set of the present invention can be used as a black ink and a color ink. In particular, in a recording method based on a thermal inkjet system in which ink is ejected using a heating unit, a good image can be obtained by using the ink set of the present invention. further,
Before or after printing, apply 50-
Heating at 200 ° C, it is also possible to use a material that has the function of promoting print fixing, such as plain paper, glossy paper, special paper,
In addition to the method of printing directly on cloth, film, OHP, etc., the present invention provides a method of printing on an intermediate drum or belt, preparing an ink image on the intermediate, and transferring and recording on paper, cloth, film, etc. Can be recorded by using the ink set.

[Inkjet recording method using reaction liquid] The ink set of the present invention can sufficiently achieve the object by using it in an ink jet recording method not using a reaction liquid. By using the recording method, a better image can be obtained.

The ink jet recording method using two liquids is a recording method including a step of adhering a reaction liquid containing a reactant and the above-mentioned ink set onto a recording medium such as paper. The reactant destroys the dispersed state of the pigment, or reacts with the dye to destroy the dissolved or dispersed state of the dye and causes aggregation.

In the present invention, the dispersion of the pigment is destroyed by the contact of the reaction liquid with the ink, or the reaction with the dye destroys the dissolved or dispersed state of the dye, and the respective pigments are aggregated. Agglomerates adhere to the recording medium,
An image with high image density and no bleeding can be obtained.
The reaction liquid may be attached to the recording medium by a method of selectively attaching only the portion to which the ink is attached, or by a method of attaching the ink to the entire recording medium. The supply of the reaction liquid to the recording medium may be performed by any of an ink jet recording method and a method of attaching the reaction liquid with a roller or the like. Furthermore, a recording medium to which such a reactant has been applied in advance can also be used. The order in which the reaction liquid and the ink set are attached to the recording medium may be either first, but the reaction liquid is more effective first.

As the reactant, an electrolyte or the like can be used. Examples of the electrolyte include alkali metal ions such as lithium ion, sodium ion, and potassium ion, and aluminum ion, barium ion, calcium ion, copper ion, iron ion, magnesium ion, manganese ion, nickel ion, tin ion, titanium ion, and zinc ion. And polyvalent metal ions such as hydrochloric acid,
Organic carboxylic acids such as hydrobromic acid, hydroiodic acid, sulfuric acid, nitric acid, phosphoric acid, thiocyanic acid, and acetic acid, oxalic acid, lactic acid, fumaric acid, fumaric acid, citric acid, salicylic acid, and benzoic acid, and salts of organic sulfonic acids And the like. It is also possible to use a cationic substance that becomes an organic cation by dissociation in water, and specifically, primary, secondary,
Tertiary and quaternary amines and salts thereof are included.

Specific examples of the electrolyte include lithium chloride,
Salts of alkali metals such as sodium chloride, potassium chloride, sodium bromide, potassium bromide, sodium iodide, potassium iodide, sodium sulfate, potassium nitrate, sodium acetate, potassium oxalate, sodium citrate, potassium benzoate, and Aluminum chloride, aluminum bromide, aluminum sulfate, aluminum nitrate, sodium aluminum sulfate, potassium aluminum sulfate, aluminum acetate, barium chloride, barium bromide, barium iodide, barium oxide, barium nitrate, barium thionate, calcium chloride, bromide Calcium, calcium iodide, calcium nitrite, calcium nitrate, calcium dihydrogen phosphate, calcium thiocyanate, calcium benzoate, calcium acetate, calcium salicylate, calcium tartrate, Calcium oxide, calcium fumarate, calcium citrate, copper chloride, copper bromide, copper sulfate, copper nitrate, copper acetate, iron chloride, iron bromide, iron iodide, iron sulfate, iron nitrate, iron oxalate, iron lactate, Iron fumarate, iron citrate, magnesium chloride, magnesium bromide, magnesium iodide, magnesium sulfate, magnesium nitrate, magnesium acetate, magnesium lactate, manganese chloride, manganese sulfate, manganese nitrate, manganese dihydrogen phosphate, manganese acetate, salicylic acid Manganese, manganese benzoate, manganese lactate, nickel chloride, nickel bromide, nickel sulfate, nickel nitrate, nickel acetate, tin sulfate, titanium chloride, zinc chloride, zinc bromide, zinc sulfate, zinc nitrate, zinc thiocyanate, zinc acetate And the like, and salts of polyvalent metals.

Among these, preferred electrolytes include
Aluminum sulfate, calcium chloride, calcium nitrate,
Calcium acetate, magnesium chloride, magnesium nitrate, magnesium sulfate, magnesium acetate, tin sulfate,
Examples include zinc chloride, zinc nitrate, zinc sulfate, zinc acetate, aluminum nitrate, monoallylamine polymer, diallylamine polymer, diallyldimethylammonium chloride polymer and the like.

On the other hand, specific examples of the cationic substance include:
Tetraalkylammonium salts, alkylamine salts, benzalkonium salts, alkylpyridium salts, imidazolium salts, polyamines and the like, specific examples of which include:
Isopropylamine, isobutylamine, t-butylamine, 2-ethylhexylamine, nonylamine, dipropylamine, diethylamine, trimethylamine, triethylamine, dimethylpropylamine, ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, tetraethylenepentamine, diethanolamine, diethyl Ethanolamine,
Triethanolamine, tetramethylammonium chloride, tetraethylammonium bromide, dihydroxyethylstearylamine, 2-heptadecenyl-
Examples thereof include hydroxyethylimidazoline, lauryldimethylbenzylammonium chloride, cetylpyridinium chloride, stearamidomethylpyridium chloride, diallyldimethylammonium chloride polymer, diallylamine polymer, and monoallylamine polymer.

The reaction solution preferably contains a water-soluble organic solvent. Examples of the water-soluble organic solvent include ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,5-pentanediol, 1,2,6-
Polyhydric alcohols such as hexanetriol and glycerin, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether Polyhydric alcohol derivatives such as pyrrolidone, N-methyl-2-pyrrolidone, cyclohexylpyrrolidone, nitrogen-containing solvents such as triethanolamine, ethanol, isopropyl alcohol, butyl alcohol,
Alcohols such as benzyl alcohol, sulfur-containing solvents such as thiodiethanol, thiodiglycerol, sulfolane and dimethyl sulfoxide, propylene carbonate, ethylene carbonate and the like can be used.

The water-soluble organic solvent used in the reaction solution may be used alone or as a mixture of two or more. The content of the water-soluble organic solvent in the reaction solution is 1%. ~
It is preferably 60% by weight, more preferably 5 to 40% by weight.

[0061]

The present invention will be described below in detail with reference to examples and test examples. Prepare the following components 1 to 5 and add ultrapure water to make the total amount 100 g.
After stirring for minutes, the mixture was dispersed with an ultrasonic homogenizer. Thereafter, coarse particles were removed by a centrifuge (12,000 rpm, 30 minutes) to prepare a final pigment dispersion. In the following, "weight average molecular weight" is a value measured by the GPC method.

Component 1: Black dispersion liquid 1 Carbon black (# 25, manufactured by Mitsubishi Chemical Corporation) 20% by weight Styrene / potassium methacrylate 5% by weight (polymer dispersant: weight average molecular weight 3500)

Component 2: Cyan color dispersion CI Pigment Blue 15: 3 15% by weight 3% by weight of sodium polyacrylate

Component 3: Magenta color dispersion CI Pigment Red 122 20% by weight Formalin condensate of sodium naphthalene sulfonate 3% by weight (polymer dispersant: weight average molecular weight 1500, sulfonation degree 95%)

Ingredient 4: Yellow color dispersion CI Pigment Yellow 55 15% by weight 4% by weight of sodium polyacrylate

Next, the following ink components were mixed, stirred for 2 hours, and then filtered under pressure using a 0.45 μm membrane filter to prepare inks of each color. 5 was prepared.・ Ink set 1 (dye only for color material of yellow ink) (black ink) Component 1 25% by weight Diethylene glycol 10% by weight Isopropyl alcohol 2% by weight Surfactant 0.1% by weight (Orifin E1010: Nissin Chemical Co., Ltd.) Pure water 62.9% by weight (cyan ink) Component 2 20% by weight Glycerin 10% by weight Ethylene glycol 10% by weight Fluorinated surfactant 1% by weight (Fluorard FC-104: manufactured by 3M) Ultra pure water 59% by weight ( Magenta ink) Component 3 20% by weight Thiodiethanol 10% by weight Glycerin 5% by weight Butyl carbitol 7% by weight Ultrapure water 58% by weight (yellow ink) CI Direct Yellow 144 1.5% by weight CI Direct Yellow 86 0.5% by weight 2-Pyrrolidone 15% by weight Butyl carbitol 4% by weight % Ultra pure water 79% by weight

Ink set 2 (all ink colorants are pigments) (black ink) Same as ink set 1 above. (Cyan ink) Same as ink set 1 above. (Magenta ink) Same as ink set 1 above. (Yellow ink) Component 4 20% by weight Diethylene glycol 10% by weight Surfactant 1.5% by weight (Pluronic PE64: manufactured by BASF) Ultrapure water 68.5% by weight

Ink set 3 (all ink colorants are dyes) (black ink) CI direct black 168 4% by weight Glycerin 10% by weight Isopropyl alcohol 3% by weight Sulfolane 10% by weight Urea 5% by weight Surface activity 0.05% by weight (Nonion E-215: manufactured by NOF Corporation) 67.95% by weight of ultrapure water (cyan ink) 50% by weight of Projet Fast Blue 2 (manufactured by Zeneca) 20% by weight of ethylene glycol Butyl carbitol 5% by weight Urea 6% by weight Surfactant 1.5% by weight (Pluronic PE43: manufactured by BASF) Ultrapure water 17.5% by weight (magenta ink) Projet Fast Magenta 2 40% by weight (manufactured by Zeneca) Diethylene glycol 20 9% by weight of butyl carbitol 9% by weight of surfactant 0.5% by weight (Surfino 104: manufactured by Nissin Chemical Industry Co., Ltd.) ultrapure water 30.5 wt% (yellow ink) same as yellow ink of the ink set 1.

Ink set 4 (coloring material is dye only in yellow ink) (black ink) 20% by weight of Cavojet 300 (self-dispersion type carbon black: manufactured by Cabot Corporation) 15% by weight of glycerin 6% by weight of urea 1% by weight of surfactant (Orifin E1010: manufactured by Nissin Chemical Co.) Ultrapure water 58% by weight (cyan ink) Same as ink set 1. (Magenta ink) Same as ink set 1. (Yellow ink) Same as ink set 1.

Ink set 5 (color material of yellow ink and magenta ink is dye) (Black ink) Same as ink set 4 (Cyan ink) Same as ink set 1. (Magenta ink) Same as ink set 3. (Yellow ink) Same as ink set 1.

Ink set 1 + reaction liquid (reaction liquid) Diglycerin ethylene oxide adduct 10% by weight Calcium nitrate tetrahydrate 3% by weight Surfactant (Surfinol 465: manufactured by Nissin Chemical Co.) 3% by weight isopropyl Alcohol 3% by weight Deionized water 81% by weight These components were stirred for 2 hours and filtered under pressure using a 0.45 μm membrane filter to obtain a reaction solution. This reaction liquid was used in combination with the ink set 1.
The evaluation in Test Example 1 described below was performed using a JetXR made by Fuji Xerox Co., Ltd., which was modified so that the reaction liquid was printed on the portion where the ink adhered to the paper and the ink was printed immediately afterwards.
Performed using ind 300C.

Test Example 1 The following tests were performed on the above-mentioned ink sets 1 to 5 and ink set 1 + reaction liquid, and the results are summarized in Table 1. (1) Evaluation of image quality Using an inkjet printer JetWind300C manufactured by Fuji Xerox Co., Ltd., a landscape image was converted to FX-L.
Paper (Fuji Xerox) and JetWind300
C was prepared on a special glossy paper. About that image, 20
A person gave a score out of 10 points, and evaluated based on the following criteria based on the average score.

◎: Average score of 9 or more ○: Average score of 7 or more ・ ・ ・: Average score of 5 to less than 7 ×: Average score of less than 5

(2) Water Resistance Solid images with 100% coverage of each color were formed on FX-L paper in the same manner as in (1) above. The density of this solid image was measured with a Macbeth densitometer. It was left for 24 hours from the end of printing, then immersed in water for 3 minutes, taken out and dried, and the density was measured again. The density remaining ratio of the printed image was obtained and used as an index of water resistance.・ ・ ・: Residual density of 85% or more △: Residual density of 50% to less than 85% ×: Residual density of less than 50%

(3) Light fastness In the same manner as in (2) above, 100% coverage images of each color were prepared, and the density was measured with a Macbeth densitometer. Twenty-four hours after printing was completed, the xenon lamp was irradiated for 12 hours.
The change in concentration before and after irradiation was examined. If the image density after irradiation was 95% or more before irradiation, it was evaluated as ○, and if less than 95%, it was evaluated as X.

(4) Fixability A full-color image was prepared in the same manner as in (1) above, and each of the blue, green, and red portions was strongly rubbed with a fingertip five times, and evaluated according to the following criteria.・ ・ ・: No stain is generated around the image. ×: Stain is generated around the image.

[0077]

[Table 1]

As is clear from the results shown in Table 1,
Ink set 1 using only yellow ink as color material as dye
In Nos. And 4, excellent results were obtained in all respects of image evaluation, water fastness, light fastness and fixability. Further, in the example in which the ink set 1 and the reaction liquid were combined, more excellent results were obtained. In the ink set 5 using the coloring materials of the yellow ink and the magenta ink as dyes, favorable results were obtained after the ink sets 1 and 4.

[0079]

According to the present invention, a clear, high-definition full-color image can be obtained, and an ink set for inkjet recording can be obtained which has good image storage stability such as water resistance and light fastness and also has good image fixability. Can be Further, according to the present invention,
An inkjet recording method using the ink set is provided.

Continued on the front page (72) Inventor Isaichi Yamashita 1600 Takematsu, Minami Ashigara City, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Koji Doi 1600 Takematsu, Minami Ashigara City, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. Ken 1600 Takematsu, Minamiashigara-shi, Kanagawa Prefecture Fuji Xerox Co., Ltd. F-term (reference) 4J039 BA04 BE03 BE04 CA03 CA06 EA15 EA16 EA17 EA19 EA35 EA38 EA42 EA43 EA44 GA24

Claims (2)

[Claims] 1. An ink set including a cyan ink, a magenta ink, a yellow ink, and a black ink, wherein one or two of the cyan ink, the magenta ink, and the yellow ink include a water-soluble coloring material and water as essential components. An ink set, wherein the remaining ink and the black ink are inks containing a water-insoluble colorant and water as essential components. 2. An ink jet recording method using the ink set according to claim 1.