JP2003213165A - Ink for inkjet recording - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink for inkjet recording, which can give a print almost free from blotting on plain paper, particularly a recycled paper. <P>SOLUTION: This water-base ink for inkjet recording is characterized in that is contains a coloring material, a water-soluble organic solvent and water and that it also contains a substance having a structure represented by formula (I) [wherein R<SB>1</SB>, R<SB>2</SB>, R<SB>3</SB>and R<SB>4</SB>are each independently methyl, ethyl, propyl or butyl; A and B are each independently ethylene oxide group, propylene oxide group, or a mixture of the ethylene oxide group and the propylene oxide group; and j+k (average) ≤50] and a substance having a structure represented by the formula (II): R<SB>5</SB>-(PO)n-(EO)m-OH (wherein R<SB>5</SB>is a 4-20C alkyl or cycloalkyl; PO is propylene oxy group; EO is ethylene oxy group; and (n) and (m) are each the number of repeating units in the molecule, provided that 0.5≤n≤5 and 3≤m≤30, irrespectively of the order of PO and EO). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording ink which can obtain high print quality on plain paper, recycled paper or coated paper.

[0002]

2. Description of the Related Art Ink jet recording is a method of recording characters or figures on the surface of a recording medium by ejecting ink as small droplets from fine nozzles. The inkjet recording method uses an electrostrictive element to convert an electrical signal into a mechanical signal and intermittently ejects ink stored in the nozzle head to record characters or symbols on the surface of a recording medium, or a nozzle head A method of recording characters or symbols on the surface of a recording medium by rapidly heating the ink very close to the discharge area to generate bubbles and discharging the ink intermittently due to the volume expansion of the bubbles Have been put to practical use.

The inks used for such ink jet recording have good dryness of printing, no bleeding of printing, uniform printing on the surface of all recording materials, and in the case of multiple colors, colors are mixed. Characteristics such as not being required are required. Here, a particular problem is that when paper is used as the recording medium, bleeding is likely to occur due to fibers having different penetrability.

In the conventional ink for ink jet recording, glycol ether is used as a wetting agent as in JP-B-2-2907, a water-soluble organic solvent as in JP-B-1-15542, or JP-B-2-3837. In many cases, it was used as a dye dissolution accelerator as in Japanese Patent Laid-Open Publication No.

Further, in order to improve the permeability, diethylene glycol monobutyl ether is added, as in US Pat. No. 5,156,675, or US Pat. No. 518.
Surfeneol 465 (manufactured by Nissin Chemical Co., Ltd.), which is an acetylene glycol-based surfactant, is added as in No. 3502, or both diethylene glycol monobutyl ether and Surfynol 465 are added as in US Pat. No. 5,196,056. Is being studied. Diethylene glycol mono-n-butyl ether is called butyl carbitol and is described, for example, in US Pat. No. 3,291,580. Alternatively, in U.S. Pat. No. 2,083,372, the use of diethylene glycol ethers in the ink is considered.

[0006] Further, in many cases where pigments are used, it has been mainly studied to suppress penetrability to suppress wetting of the ink on the surface of the paper to secure printing quality, and it has been put to practical use. Alternatively, as a combination of a glycol ether and a pigment, there is an example in which triethylene glycol monomethyl ether is used for the pigment as in JP-A-56-147861.

[0007]

However, in the prior art, the permeability of ink to paper is often insufficient, and the method of suppressing wetting on the surface of paper is not suitable for plain paper, especially recycled paper that is often used. There is a problem in that the ink on the printed paper is difficult to dry and cannot be immediately overlaid when continuous printing is performed because the printed matter bleeds and it takes time to dry the printed matter. Further, since recycled paper is an aggregate of various paper components mixed and having different permeation rates, it easily bleeds due to the difference in their permeation rates. In order to reduce the bleeding, a method of heating paper is generally considered. However, if the paper or other printing object is heated during printing, it takes time to start the heating part in the device to a predetermined temperature, the power consumption of the device increases, or the paper or other printing object is heated. There is a problem that the printed matter is damaged.

In the case of printing on a paper or the like having an ordinary sizing agent as a recording medium with the ink using the pigment,
If the ink is not permeated to some extent, the pigment remains on the surface of paper or the like, and the scratch resistance deteriorates.
However, if the permeability is halfway, the paper type is limited or the quality of the printed image is likely to deteriorate in order to perform uniform printing.

Further, in the ink using a pigment, a glycol ether is used as a glycol ether in order to control the permeability.
Methyl ethers such as those used in Japanese Patent No. 47861 are often used. In addition, a pigment-based ink for inkjet recording, which can improve the penetrability with butyl ethers and can print on many papers with little blurring, has not yet been known.

The present invention solves such a problem, and its purpose is to provide a heating means for plain paper, which is very fast, and for recycled paper which has been frequently used in recent years. Even so, it is an object to provide an ink for inkjet recording capable of printing with almost no blurring.

[0011]

The inkjet recording ink of the present invention is a water-based inkjet recording ink containing a coloring material, a water-soluble organic solvent and water, and further comprises a substance having a structure represented by the following formula (I): And a substance having a structure represented by the following formula (II).

[0012]

[Chemical 1] R ₁ , R ₂ , R ₃ and R ₄ are each independently a methyl group, an ethyl group, a propyl group or a butyl group, and A and B are each independently an ethylene oxide group, a propylene oxide group, or an ethylene oxide group and a propylene oxide. It is a base. j + k (average value) ≦ 50.

[Chemical 2] R ₅ is an alkyl group or a cycloalkyl group having 4 to 20 carbon atoms, PO is a propyleneoxy group, EO is an ethyleneoxy group, n and m are repeating units in the molecule, and 0.5 ≦ n ≦ 5, 3 ≦ m ≦ 30, and the order of EO and PO does not matter.

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the ink used for ink jet recording has characteristics such as good drying property of printing, no bleeding of printing, and uniform printing on all recording materials. In view of what is required,
This is due to the result of diligent examination.

If the amount of the substance of the formula (I) used in the present invention is less than 0.1% by weight, the effect of improving the printing quality is not recognized, so it is necessary to add it by 0.1% by weight or more. Also, 1
If the amount exceeds 0% by weight, the viscosity increases and stable printing cannot be performed. Therefore, the amount should be 10% by weight or less.

Further, since a water-soluble ink for ink jet recording is used in the present invention, the surfactant to be used needs to be water-soluble, and its HLB is preferably high. The compound of formula (II) preferably has an HLB of 7 or more.

R ₁ , R ₂ , R ₃ , R ₄ shown in the above formula (I)
Are each independently selected from a methyl group, an ethyl group, a propyl group and a butyl group, and the propyl group and the butyl group include respective structural isomers, R ₁ ,
Since the water solubility varies depending on the structure of R ₂ , R ₃ and R ₄ and the type of isomer, a substance having a structure represented by the formula (II) is appropriately selected and a combination thereof does not cause a cloud point and print quality. It is necessary to appropriately select a region in which is excellent.

Further, the total of j and k shown in the above formula (I) is characterized by being at least 50 or less. When this value exceeds 50, the molecular weight increases and the ability as a surfactant decreases. However, if it exceeds 50, it does not mean that it cannot be used.

In the substance having the structure represented by the above formula (II), R ₅ is an alkyl group having 4 to 20 carbon atoms or a cycloalkyl group, n is 0.5 to 5 and m is 3 to 30. It is preferable. When R ₅ has less than 4 carbon atoms or more than 20 carbon atoms, the effect of the substance of formula (I) as a solubilizing agent becomes low.
It is preferably 6 to 18, more preferably 8 to 16
Is. When n is less than 0.5, the foaming becomes large, and the effect of the substance of the formula (I) as a solubilizing agent becomes low, and when n exceeds 5, the molecular weight becomes large and the substance of the formula (I) dissolves. In order to obtain the effect as an auxiliary agent, it is necessary to add a large amount, and particularly when a pigment is used, its dispersion stability tends to be deteriorated. When m is less than 3, the solubility in water is low and the effect of the substance of the formula (I) as a solubilizing agent is low, and when it exceeds 30, the effect of the substance of the formula (I) is solubilizing agent. For this, a large amount of addition is required.

The amount of the substance having the structure represented by the formula (II) is 0.1 to 10 times that of the substance having the structure represented by the formula (I). If it is less than 0.1 times, the effect as a dissolution aid is low, and if it is added 10 times or more, the effect as a dissolution aid is at a level. It is more preferably 0.2 to 2 times.

The amount of the substance represented by the formula (I) added to the ink is preferably 0.1% by weight or more and 10% by weight or less. If it is less than 0.1% by weight, the effect of improving the printing quality is low, and if it exceeds 10% by weight, the viscosity increases and the foaming increases, which is not preferable for inkjet recording.

The coloring material is one or more selected from water-soluble dyes, water-soluble pigments which are dispersible in water by surface treatment of pigments, and water-soluble pigments which are dispersible in water by a dispersion polymer. And In the present invention, many coloring materials can be used. In addition to a water-soluble dye, a water-soluble pigment which is made dispersible in water by surface treatment to be soluble, and a water-soluble pigment made dispersible in water by a dispersion polymer. A pigment or the like can be used.

Further, it is preferable to add at least alkylene glycol monoalkyl ether and / or 1,2-alkylene glycol to the above ink jet recording ink. The above alkylene glycol monoalkyl ether is an alkylene glycol having 10 or less repeating units and having 4 to 10 carbon atoms.
The alkyl ether of is preferable. An alkylene glycol having 10 or less repeating units and an alkyl ether having 4 to 10 carbon atoms is di (tri) ethylene glycol monobutyl ether and / or (di).
It is preferably propylene glycol monobutyl ether. Furthermore, the above-mentioned 1,2-alkylene glycol is 1,2-hexanediol and / or 1,2-
It is preferably pentanediol.

The amount of the above-mentioned substance consisting of one or more selected from di (tri) ethylene glycol monobutyl ether, (di) propylene glycol monobutyl ether and 1,2-alkylene glycol is 0.5% by weight or more. It is preferably 30% by weight or less. 0.5
If it is less than wt%, the penetrating effect is low and the printing quality is not improved. If it exceeds 30% by weight, it becomes difficult to use due to an increase in viscosity, and addition of more than that does not have the effect of improving printing quality. It is more preferably 1% by weight or more and 15% by weight or less.

It is preferable that the substance represented by the above formula (I) is contained in an amount of 0.1% by weight or more and 5% by weight or less. If the amount exceeds 5% by weight, the effect of print quality reaches a ceiling, and even if added, the viscosity increases and it becomes difficult to use, and ink easily sticks to the tip of the head, and printing is prone to be disturbed. If it is less than 0.1% by weight, the effect of improving the printing quality becomes low. A more preferable addition amount is 0.15 to 2% by weight.

Then, at least one substance selected from the above-mentioned formula (I) and di (tri) ethylene glycol monobutyl ether, (di) propylene glycol monobutyl ether and 1,2-alkylene glycol is added at the same time. It is preferable. A substance represented by the formula (I) and di (tri) ethylene glycol monobutyl ether,
The printing quality is improved when at least one selected from (di) propylene glycol monobutyl ether and 1,2-alkylene glycol is used at the same time.

The substance represented by the above formula (I) is 0.1
Is 0.5 to 0.5% by weight, and it is preferable that one or more kinds selected from di (tri) ethylene glycol monobutyl ether, (di) propylene glycol monobutyl ether and 1,2-alkylene glycol be 1% by weight or more. A small amount of the substance represented by the formula (I) has an effect of improving permeability. Therefore, it is less than 0.5% by weight, and
The print quality is further improved when the content of one or more selected from ethylene glycol monobutyl ether, (di) propylene glycol monobutyl ether and 1,2-alkylene glycol is 1% by weight or more.

The colorant in which the pigment is dispersed by the dispersion polymer is a polyacrylic ester, styrene-acrylic acid copolymer, polystyrene, polyester, polyamide,
It is preferable to have at least one selected from the group consisting of polyimide, a silicon-containing polymer and a sulfur-containing polymer as a main component. The substance represented by the formula (I) used in the present invention, one or more kinds selected from di (tri) ethylene glycol monobutyl ether, (di) propylene glycol monobutyl ether and 1,2-alkylene glycol is an ordinary dispersant. Since a adsorption / desorption reaction occurs with the dispersant used for dispersion, the desorbed dispersant floats in the ink, which tends to cause a phenomenon in which printing is disturbed. However, it is preferable to carry out suitable dispersion using the above-mentioned polymer, because the polymer stably contains the colorant, and adsorption and desorption do not easily occur.

Further, the colorant in which the pigment is dispersed in the dispersion polymer is preferably a pigment containing the pigment in the form of a copolymer of at least a dispersant having a polymerizable group and a copolymerizable monomer. Here, the dispersant having a polymerizable group is one having at least a hydrophobic group, a hydrophilic group and a polymerizable group, and the polymerizable group is an acryloyl group, a methacryloyl group, an allyl group or a vinyl group, and the copolymerizable group. Is also an acryloyl group, a methacryloyl group, an allyl group or a vinyl group. Since it is preferable for the ink jet recording ink to have a relatively uniform particle size from the viewpoint of clogging and ejection stability, the colorant containing the pigment in the polymer is preferably produced by emulsion polymerization. In addition, the polymer is preferably a dispersion containing at least one selected from the group consisting of polyacrylic acid ester, styrene-acrylic acid copolymer, polystyrene, polyester, polyamide, polyimide, silicon-containing polymer, and sulfur-containing polymer as a main component. Since a suitable dispersion is made by the agent, a solid polymer is obtained, which is a substance consisting of one or more substances selected from the substance of formula (I), glycol ethers and 1,2-alkylene glycol which are preferable in the present invention. It is not deformed by addition, and it is easy to obtain a uniform particle size.

The colorant containing the above-mentioned pigment in a polymer is prepared by dispersing the pigment with a dispersant having a polymerizable group,
It is preferably emulsion-polymerized in water using a monomer copolymerizable with the dispersant and a polymerization initiator.

The above-mentioned 1,2-alkylene glycol is a C4-C10 1,2-alkylene glycol,
The addition amount is preferably 15% by weight or less. If the amount added exceeds 10% by weight, the viscosity will increase, making it difficult to use for ink jet applications, and addition of more than that will not have the effect of improving print quality.

The above-mentioned 1,2-alkylene glycol is preferably 1,2-pentanediol and / or 1,2-hexanediol. The amount of 1,2-pentanediol is preferably 3 to 15% by weight. If it is less than 3% by weight, the effect of improving the permeability is low, and therefore bleeding often occurs. If the addition amount exceeds 15% by weight, the water solubility is low, so that it is difficult to use in the water-soluble ink as in the present invention.
The amount of 1,2-hexanediol is preferably 0.5 to 10% by weight. If it is less than 0.5% by weight, the effect of improving the permeability is low, and if it is more than 10% by weight, the water solubility is low, so that it is difficult to use it in the water-soluble ink of the present invention. When the addition amount of the substance represented by the above formula (I) is 0.5% by weight or more, the ratio with the 1,2-alkylene glycol (hereinafter, simply referred to as ratio indicates the weight ratio of the addition amount) is 1 : 0 to 1: 1
A value of 0 is preferable from the viewpoint of printing quality, and when the amount of 1,2-alkylene glycol exceeds 10 times that of the substance represented by formula (I), the effect of improving the printing quality reaches the ceiling and the effect is low even if added more, On the contrary, it causes an adverse effect of increasing the viscosity.

The amount of addition of the substance represented by the above formula (I) is 0.5.
It is preferable that the amount is at least wt% and the ratio of the amount of the 1,2-alkylene glycol added is 1: 0 to 1:10. And it is preferable that the above-mentioned (di) propylene glycol monobutyl ether is contained in an amount of 10% by weight or less. 1
If the amount exceeds 0% by weight, the effect of improving the printing quality reaches a ceiling, and conversely, the adverse effect of increased viscosity and low water solubility require addition of a solubilizing agent. It is more preferably 0.5 to 5% by weight.

The ratio of the substance represented by the above formula (I) to the (di) propylene glycol monobutyl ether is 1: 0 to 1: 1.
It is preferably 0. When the amount of (di) propylene glycol monobutyl ether exceeds 10 times that of the substance represented by the formula (I), the effect of improving the printing quality reaches a peak, and the effect is low even if it is added more and the adverse effect of increasing the viscosity occurs.

It is preferable that the di (tri) ethylene glycol monobutyl ether is contained in an amount of 20% by weight or less.
If it exceeds 20% by weight, it becomes difficult to use due to an increase in viscosity.
Adding more than that does not have the effect of improving print quality. More preferably, it is 1% or more and 15% by weight or less. Di (tri) ethylene glycol monobutyl ether is diethylene glycol monobutyl ether (DEGmBE) and /
Or triethylene glycol monobutyl ether (T
EGmBE), but addition of 20% by weight or less is preferable as a necessary level of permeability for improving print quality.
If the amount exceeds 20% by weight, the effect of improving the printing quality reaches the ceiling and, conversely, the adverse effect of increasing the viscosity occurs. More preferably 0.
It is 5 to 10% by weight.

The amount of addition of the substance represented by the above formula (I) is 0.5.
It is preferably at least wt% and the ratio with di (tri) ethylene glycol monobutyl ether is preferably 1: 0 to 1:10. From the viewpoint of print quality, it is preferable to add up to 10 times the amount of the substance represented by the formula (I). Di (tri) ethylene glycol monobutyl ether is useful for improving the solubility of the substance represented by the formula (I) and for improving the printing quality.
If the added amount exceeds twice, those effects will reach the ceiling, and it will be difficult to use for inkjet. The components of the inkjet recording ink of the present invention include preservatives, antioxidants, conductivity adjusters, pH adjusters, viscosity adjusters, surface tension adjusters, oxygen absorbers, nozzle clogging preventives, and the like. Additives can be used as appropriate.

It is preferable to add a water-soluble glycol in order to suppress drying on the front surface of the ink nozzle,
Examples thereof include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol having a molecular weight of 2000 or less,
1,3-propylene glycol, isopropylene glycol, isobutylene glycol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, glycerin, mesoerythritol, pentaerythritol, etc. There is.

Further, in the present invention, many kinds of sugars can be used in order to prevent the ink from drying and clogging in front of the nozzle. There are monosaccharides and polysaccharides, glucose, mannose, fructose, ribose, xylose, arabinose, lactose, galactose, aldonic acid, glucitol, maltose, cellobiose, sucrose, trehalose, maltotriose, etc., as well as alginic acid and its salts, cyclo. Dextrins and celluloses can be used. The addition amount is preferably 0.05% or more and 30% by weight or less. 0.05
If it is less than 30% by weight, the effect of recovering the clogging phenomenon in which the ink is dried and clogged at the tip of the head is small. Glucose, mannose, fructose, ribose, xylose, arabinose, lactose, galactose, aldonic acid, glucitoses, maltose, cellobiose, sucrose, trehalose, maltotriose, etc., which are common sugars, which are common sugars, are more preferably added. Is 3 to 20% by weight. Alginic acid and its salt, cyclodextrins, and celluloses must be added in amounts such that the viscosity of the ink does not become too high.

In addition to the above, the solubility of glycol ethers and ink components, which are compatible with water and have low solubility in water contained in ink, is improved, and further the permeability to a recording medium such as paper is improved, Alternatively, as a substance that can be used to prevent nozzle clogging, there are alkyl alcohols having 1 to 4 carbon atoms such as ethanol, methanol, butanol, propanol, and isopropanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene. Glycol monobutyl ether, ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, ethylene glycol mono Iso-propyl ether, diethylene glycol mono-iso-propyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol mono-t-butyl ether, diethylene glycol mono-t-butyl ether, 1-methyl-1-methoxybutanol, propylene glycol monomethyl ether, Propylene glycol monoethyl ether, propylene glycol mono-t-butyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-Iso-propyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono- Glycol such as n-propyl ether, dipropylene glycol mono-Iso-propyl ether There are ethers, formamide, acetamide, dimethyl sulfoxide, sorbit, sorbitan, acetin, diacetin, triacetin, sulfolane, etc., which can be appropriately selected and used. The amount used is 5 to 60% by weight based on the total amount of the ink. Is preferred.

Further, the ink jet recording ink according to the present invention may further contain other surfactants for controlling the permeability or improving the water solubility of the substance of the formula (I). . The surfactant to be added is preferably a surfactant having good compatibility with the ink system shown in the present embodiment, and among the surfactants, those having high permeability and stability are preferable. Examples thereof include amphoteric surfactants and nonionic surfactants. As the amphoteric surfactant, lauryl dimethylamino acetic acid betaine, 2-alkyl-
Examples include N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut oil fatty acid amide propyldimethylaminoacetic acid betaine, polyoctylpolyaminoethylglycine and other imidazoline derivatives. Nonionic surfactants include polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene Ether type such as ethylene alkyl ether, polyoxyalkylene alkyl ether, polyoxyethylene oleic acid, polyoxyethylene oleic acid ester, polyoxyethylene distearate ester, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesqui Esters such as oleate, polyoxyethylene monooleate, polyoxyethylene stearate, etc. Alkyl esters, and the like fluorine-containing surfactants such as perfluoroalkyl carboxylates.

In addition, for example, as a preservative and fungicide, sodium benzoate, sodium pentachlorophenol,
2-Pyridinethiol-1-oxide sodium, sodium sorbate, sodium dehydroacetate, 1,2
-Dibenzisothiazolin-3-one (Proxel CRL, Proxel BDN, Proxel GXL, Proxel XL-2, Proxel TN, manufactured by ICI) may be added.

Alternatively, amines such as diethanolamine, triethanolamine, propanolamine and morpholine as pH adjusting agents, solubilizing agents or antioxidants and their modified products, potassium hydroxide, sodium hydroxide, lithium hydroxide, etc. Inorganic salts, ammonium hydroxide, quaternary ammonium hydroxide (tetramethylammonium, etc.), potassium carbonate, sodium carbonate,
Carbonates such as lithium carbonate and other phosphates, ureas such as N-methyl-2-pyrrolidone, urea, thiourea and tetramethylurea, alohanates such as alohanate and methylallohanate, biuret, dimethylbiuret, tetramethyl Examples include biurets such as biuret, L-ascorbic acid and salts thereof.
Further, commercially available antioxidants, ultraviolet absorbers and the like can also be used. For example, Ciba Geigy's TinuvI
n328, 900, 1130, 384, 292, 12
3, 144, 622, 770, 292, Irgacor
252, 153, Irganox 1010, 1076,
1035, MD1024, or oxides of lanthanide.

Further, as the viscosity modifier, rosins,
Examples include alginic acid, polyvinyl alcohol, hydroxypropyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, polyacrylate, polyvinyl pyrrolidone, and gum arabic starch.

[0042]

EXAMPLES Next, specific examples of the present invention will be described, but the present invention is not limited to the following examples.

The water-soluble coloring material used in the present invention will be described using a dye, a pigment, and a dye and a pigment.

(Production of Surface-treated Pigment) The water-soluble pigment 1 has a carboxyl group attached to the surface of carbon black.
It was prepared by oxidizing carbon black with hypochlorous acid as follows. The carbon black Monarch 880 (made by Cabot) is wetted with water, an aqueous solution of sodium hypochlorite is added, and the mixture is heated at 100 ° C. for 24 hours. Thereafter, washing with water and centrifugation are repeated to remove residual hypochlorite, chlorine or coarse particles. When the surface-treated pigment is black, it can be purchased as a commercial product. As a carbon black that can be dispersed in water without a dispersant by an anionic group, there is CABOJET 300 manufactured by Cabot Corporation or CW1 manufactured by Orient Chemical Co., Ltd. As a carbon black which can be dispersed in water by a cationic group without a dispersant, there is Cabot Jet IJX55 manufactured by Cabot Corporation.

On the other hand, the water-soluble pigment 2 was obtained by oxidizing carbon black with sulfamic acid so that the surface of the carbon black had sodium sulfonate groups, and was prepared as follows. JP-A-8-283596, JP-A-10-11011
10, JP-A-10-110111, JP-A-10-110
What was created by the method similar to the method described in Japanese Patent No. 114, etc. was used. The carbon black pigment is dispersed in sulfolane, added to this dispersion, and then heated to 120 ° C. High speed shear dispersion was carried out in advance with a high speed mixer or the like to obtain a slurry dispersion liquid. Then, after shifting to gentle stirring, a treating agent containing sulfamic acid is added to introduce a dispersing group onto the pigment surface. After this, 2
The solvent and residual sulfolane are removed from the pigment slurry by heat treatment at 00 ° C. The removal method is repeated washing with water and centrifugation.

(Production of Polymer Dispersed Pigment) JP-A-10-
According to the same method as in Example 1 described in Japanese Patent No. 316909, a reaction vessel equipped with an ultrasonic generator, a stirrer, a dropping device, a water-cooled reflux condenser, and a temperature controller was used as a carbon black pigment, Raven C (Colombia). 5 parts (manufactured by NCarbon Co., Ltd.) (hereinafter simply referred to as parts represent parts by weight) and 3 parts of Adeka Riasoap SE-10N manufactured by Asahi Denka Co., Ltd. which is a polymerizable surfactant. In addition to 80 parts, ultrasonic waves are dispersed for 4 hours. Next, 1.6 parts of acrylonitrile and 0.05 parts of potassium persulfate are further added, and a polymerization reaction is carried out at 60 ° C. for 48 hours. The resulting solution is filtered through a 0.4 μm membrane filter to remove coarse particles.

Next, the reaction vessel is further charged with ion-exchanged water 2
7 parts and 0.05 part of sodium lauryl sulfate are added, 100 parts of ion-exchanged water and 0.5 part of potassium persulfate as a polymerization initiator are further added, and a nitrogen atmosphere at 70 ° C. is maintained.
Then, after adding 3 parts of ADEKA REASOAP SE-10N and stirring, a mixed solution containing 15 parts of styrene, 6 parts of tetrahydrofurfuryl methacrylate, 45 parts of butyl acrylate and 0.02 part of t-dodecyl mercaptan was added dropwise. After the reaction, the mixture is neutralized with sodium hydroxide to adjust the pH to 8 and then filtered with a 0.3 μm filter to obtain a water-soluble pigment 3 having a polymer dispersed therein.

A dispersion of water-soluble pigments 4 to 6 is obtained in the same manner as above. Pigment Blue 15: Pigment Blue 15:
3 (copper phthalocyanine pigment: manufactured by Clariant) is used. As the dispersion liquid of the pigment 5, Pigment Red 122 (dimethylquinacridone pigment: manufactured by Clariant) is used. Pigment Yellow 180 (Diketopyrrolopyrrole manufactured by Clariant) is used as the dispersion liquid of the pigment 6.

When a pigment is used, Japanese Patent Publication No. 7-94
It is also possible to use those encapsulating pigment fine particles as described in JP-A-634, JP-A-8-59715 or JP-A-2001-139849.

(Production of Emulsion A) A reaction vessel was equipped with a dropping device, a thermometer, a water-cooled reflux condenser, and a stirrer. 0.2 parts of potassium acid was added. To 7 parts of ion-exchanged water, 0.05 part of sodium lauryl sulfate, 4 parts of glycidoxy acrylate, 5 parts of styrene, 6 parts of tetrahydrofurfuryl acrylate,
A monomer solution containing 5 parts of butyl acrylate and 0.02 of t-dodecyl mercaptan is dropped at 70 ° C. and reacted to prepare a primary substance. To the primary substance, 2 parts of a 10% ammonium persulfate solution was added and stirred, and further 30 parts of ion-exchanged water, 0.2 parts of potassium lauryl sulfate, 30 parts of styrene, 15 parts of butyl methacrylate, 16 parts of butyl acrylate were added. , 2 parts of acrylic acid, 1 part of 1,6-hexanediol dimethacrylate, and 0.5 parts of t-dodecyl mercaptan were added at 70 ° C. with stirring to cause a polymerization reaction, followed by neutralization with ammonia. pH8 ~
Emulsion A was prepared by preparing an aqueous solution of polymer fine particles that had been adjusted to 8.5 and filtered through a 0.3 μm filter.

(Ink Preparation Example) The particle diameters measured by Microtrac UPA (Nikkiso Co., Ltd.) are shown in parentheses. The water-soluble dye 1 is Direct Yellow 132, and the water-soluble dye 2 is Acid Blue 9. It should be noted that, in the remaining amount and a certain amount of water in the examples, 0.1 to 1% by weight of Proxel XL-2 is used to prevent the corrosion of the ink, and 0.001 of benzotriazole is used to prevent the corrosion of the inkjet head member.
1 to 0.05 wt% was added.

Example 1 Addition amount (% by weight) Water-soluble pigment 1 (105) 5.0 Substance (1) of formula (I) 1.0 Substance (1) of formula (II) 0.3 Emulsion A 3. 0 DEGmBE 7.0 Glycerin 20.0 1,5-Pentanediol 2.0 Triethanolamine 0.8 Water Remaining amount The substance (1) of the formula (I) is R ₁ , R ₂ is a methyl group, R ₃ ,
R ₄ is an isobutyl group, A and B are propylene oxide and ethylene oxide, the propylene oxide group has an average value of 4 units, and the ethylene oxide group has an average value of 6 units. The sum of j and k is 10 on average. As the substance (1) of the formula (II), Emarex DAPE-0207 manufactured by Nippon Emulsion Co., Ltd. was used.

Example 2 Water-soluble pigment 2 (85) 3.0 Substance (2) of formula (I) 1.2 Substance (2) of formula (II) 1.0 Emulsion A 1.0 DEGmBE 10.0 Glycerin 9.0 dipropylene glycol 5.0 triethanolamine 1.0 potassium hydroxide 0.1 water remaining amount In the substance (2) of the formula (I), R ₁ and R ₂ are methyl groups, R ₃ and
R ₄ is an isobutyl group, and both A and B are 0. Expression (I
As the substance (2) of I), Emarex DAPE-02012 manufactured by Nippon Emulsion Co., Ltd. was used.

Example 3 Water-soluble pigment 3 (90) 5.5 Substance (3) of formula (I) 1.4 Substance (3) of formula (II) 1.0 1,2-hexanediol 3.0 TEGmBE 1.0 Glycerin 17.0 2-Pyrrolidone 2.0 Triethylene glycol 3.0 Triethanolamine 0.6 Water Remaining amount The substance (3) of formula (I) is R ₁ , R ₂ is an ethyl group, R ₃ ,
R ₄ is a methyl group, A and B are propylene oxide and ethylene oxide, the propylene oxide group has an average value of 4 units, and the ethylene oxide group has an average value of 10 units.
The sum of j and k is 14 on average. As the substance (3) of the formula (II), Emarex DAPE-0203 manufactured by Nippon Emulsion Co., Ltd. was used.

Example 4 Water-Soluble Pigment 4 (80) 5.0 Substance (4) of Formula (I) 0.8 Substance (4) of Formula (II) 1.0 1, 2-Hexanediol 3.0 1 , 2-Pentanediol 3.0 1,6-hexanediol 5.0 Glycerin 15.0 Tripropylene glycol 1.0 DMI 2.0 Triethanolamine 0.6 Sodium benzoate 0.1 Water Remaining formula ( As the substance (4) of I), Surfynol 104 manufactured by Air Products (USA) was used. As the substance (4) of the formula (II), Emarex DAPE-0220 manufactured by Nippon Emulsion Co., Ltd. was used.

Example 5 Water-soluble pigment 1 3.0 Substance (5) of formula (I) 0.2 Substance (5) of formula (II) 0.2 TEGmBE 5.0 PGmBE 2.0 Glycerin 10.5 1 , 5-pentanediol 3.0 triethanolamine 0.9 water residual amount The substance (5) of the formula (I) was acetylenol EL manufactured by Kawaken Chemical Co., Ltd. As the substance (5) of the formula (II), Emalex 70 manufactured by Nippon Emulsion Co., Ltd.
7 was used.

Example 6 Water-soluble dye 1 5.0 Substance (6) of formula (I) 0.5 Substance (6) of formula (II) 0.4 DPGmBE 2.0 DEGmBE 10.0 Glycerin 10.0 Neo Pentyl glycol 5.0 Triethanolamine 0.6 Remaining amount of water In the substance (6) of formula (I), R ₁ and R ₂ are methyl groups, R ₃ and
R ₄ is an n-propyl group, A and B are propylene oxide and ethylene oxide, the propylene oxide group has an average value of 2 units, and the ethylene oxide group has an average value of 4 units. The sum of j and k is 6 on average. In the water-soluble dye 2, m is 1, n is 1, and M is potassium. As the substance (6) of the formula (II), Emarex 712 manufactured by Nippon Emulsion Co., Ltd. was used.

Example 7 Water-soluble dye 2 5.0 Substance of formula (I) (7) 1.0 Substance of formula (II) (7) 1.0 TEGmBE 10.0 Glycerin 10.0 Trimethylolpropane 5. 0 triethanolamine 0.1 water remaining amount In the substance (7) of the formula (I), R ₁ and R ₂ are methyl groups, R ₃ and
R ₄ is an isobutyl group, A and B are propylene oxide and ethylene oxide, the propylene oxide group has an average value of 10 units, and the ethylene oxide group has an average value of 10 units. The sum of j and k is 50 on average. Examples of the substance (7) of the formula (II) include Emarex DAPE-0207 and Emarex DAPE- manufactured by Nippon Emulsion Co., Ltd.
A 1: 1 mixture of 0230 was used.

Example 8 Water-Soluble Pigment 1 5.5 Water-Soluble Dye 1 0.5 Substance of Formula (I) (8) 1.0 Substance of Formula (II) (8) 1.0 DPGmBE 2.0 DEGmBE 5 0.0 glycerin 10.0 triethylene glycol 5.0 triisopropanolamine 0.6 2-pyrrolidone 3.2 water remaining amount In the substance (8) of the formula (I), R ₁ and R ₂ are methyl groups, R ₃ ,
R ₄ is an isobutyl group, A and B are propylene oxide and ethylene oxide, the propylene oxide group has an average value of 1 unit, and the ethylene oxide group has an average value of 1 unit. The sum of j and k is 2 on average. As the substance (8) of the formula (II), 1: 1 of Emarex DAPE-0207 and Emarex 730 manufactured by Nippon Emulsion Co., Ltd.
The mixture was used.

The composition of the ink used in the comparative example is as follows. As the pigment shown in the comparative example, carbon black dispersed with a random copolymerization type styrene acrylic acid-based dispersant was used. The average particle size is shown in parentheses.

[0061] Comparative Example 1 Water-soluble pigment 9 (90) 5.0 Dispersant 3.0 Nonionic surfactant 0.8 2-pyrrolidone 3.0 Polyethylene glycol 1000 4.0 Deionized water remaining Comparative example 2 Water-soluble dye (Food Black 2) 5.5 Glycerin 10.0 Ethyl carbitol 10.0 2-pyrrolidone 5.0 Deionized water remaining Comparative Example 3 Water-soluble pigment 11 (110) 5.5 Water-soluble dye (Food Black 2) 2.5 Diethylene glycol 10.0 Nonionic surfactant 1.0 Deionized water remaining

(Evaluation of Printing Quality) Table 1 shows the results of printing characters of characters and evaluating the bleeding as printing evaluation results. In Table 1, A is extremely good, B is good, and C is
Is bad, and D is extremely bad.

[0063]

[Table 1]

As is clear from the results shown in Table 1, the inks used in Comparative Examples have poor print quality, and the ink jet recording ink used in the present invention has good print quality.

Incidentally, these print evaluations were measured by an ink jet printer-PM-9 manufactured by Seiko Epson Corporation.
This was done by using 00C. The papers used in these evaluations are ordinary commercial papers in Europe, America and Japan, Conqueror Paper, Favorite paper.
It Paper, Modo Copy Paper, RapId Copy
Paper, EPSON EPP paper, Xerox 4024 paper,
Xerox 10 paper, Neenha Bond paper, RI
These are copy 6200 paper, Yamayuri paper, and XeroxR paper.

In the above examples, DEGmBE is diethylene glycol mono-n-butyl ether, DMI is 1,3-dimethyl-2-imidazolidinone, PGmBE.
Is propylene glycol mono-n-butyl ether, M
PD is 2-methyl-2,4-pentanediol, DPG
mBE is dipropylene glycol mono-n-butyl ether, TEG mBE is triethylene glycol mono-n.
-Butyl ether is indicated respectively.

Further, in each of the examples, when the substance of the formula (I) was not used, the print quality was deteriorated and A shown in Table 1 was lowered to B or less. If the substance of the formula (I) is not added in each example, the solubility of the substance of the formula (I) is low, so that the addition amount is limited and the print quality is similarly deteriorated. As described above, the present invention shows that good printing quality can be obtained only when the substance of formula (I) and the substance of formula (II) are present at the same time.

The present invention should not be considered to be limited to these examples, and various modifications can be made without departing from the spirit of the present invention.

[0069]

As described above, the present invention has an effect of providing an inkjet recording ink capable of printing with little blurring on plain paper, particularly recycled paper, which has hitherto been insufficient.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2C056 EA05 FC01                 2H086 BA52 BA53 BA55 BA56 BA59                       BA62                 4J039 AD03 AD10 AE06 AE07 AE08                       AE09 AE11 AE13 BA04 BC09                       BC13 BC15 BE01 BE06 BE12                       BE22 BE33 CA03 CA06 EA47                       EA48 GA24

Claims (18)

[Claims] 1. An inkjet recording ink containing a coloring material, a water-soluble organic solvent and water, which further contains a substance having a structure represented by the following formula (I) and a substance having a structure represented by the following formula (II). A water-based ink for inkjet recording, which is characterized by: [Formula 1] Formula (I) R ₁ , R ₂ , R ₃ and R ₄ are each independently a methyl group, an ethyl group, a propyl group or a butyl group, and A and B are each independently an ethylene oxide group, a propylene oxide group, or an ethylene oxide group and a propylene oxide. It is a base. j + k (average value) ≦ 50. [Formula 2] Formula (II) R ₅ is an alkyl group or a cycloalkyl group having 4 to 20 carbon atoms, PO is a propyleneoxy group, EO is an ethyleneoxy group, n and m are repeating units in the molecule, and 0.5 ≦ n ≦ 5, 3 ≦ m ≦ 30, and the order of EO and PO does not matter. 2. The amount of the substance having the structure represented by the formula (II) is 0.1 to 10 times that of the substance having the structure represented by the formula (I). ink. 3. The addition amount of the substance represented by the formula (I) is 0.
The ink according to claim 1 or 2, wherein the content is 1% by weight or more and 10% by weight or less. 4. The coloring material is one or more selected from a water-soluble dye, a water-soluble pigment dispersible in water by surface treatment of a pigment, and a water-soluble pigment dispersible in water by a dispersion polymer. The ink according to any one of claims 1 to 3, characterized in that. 5. The ink according to claim 1, wherein at least alkylene glycol monoalkyl ether and / or 1,2-alkylene glycol is added to the ink. 6. The ink according to claim 5, wherein the alkylene glycol monoalkyl ether is an alkylene glycol having 10 or less repeating units and an alkyl ether having 4 to 10 carbon atoms. 7. An alkylene glycol having 10 or less repeating units, wherein the alkyl ether having 4 to 10 carbon atoms is di (tri) ethylene glycol monobutyl ether.
The ink according to claim 6, wherein the ink is ter and / or (di) propylene glycol monobutyl ether. 8. The ink according to claim 5, wherein the 1,2-alkylene glycol is 1,2-hexanediol and / or 1,2-pentanediol. 9. The added amount of the substance consisting of one or more selected from di (tri) ethylene glycol monobutyl ether, (di) propylene glycol monobutyl ether and 1,2-alkylene glycol is 0.5% by weight or more and 30% or more. It is below 5% by weight.
The ink according to any one of 1. 10. At least one substance selected from the above formula (I) and di (tri) ethylene glycol monobutyl ether, (di) propylene glycol monobutyl ether and 1,2-alkylene glycol are added at the same time. The ink according to any one of claims 5 to 7, wherein: 11. The substance represented by the formula (I) is 0.1% by weight to 0.5% by weight, and di (tri) ethylene glycol monobutyl ether, (di) propylene glycol monobutyl ether and 1,2-alkylene are used. The ink according to claim 10, wherein the amount of one or more selected from glycols is 1% by weight or more. 12. The dispersion polymer is one or more selected from the group consisting of polyacrylic acid ester, styrene-acrylic acid copolymer, polystyrene, polyester, polyamide, polyimide, silicon-containing polymer, and sulfur-containing polymer. The ink according to claim 4, wherein: 13. The ink according to claim 5, wherein the addition amount of the 1,2-alkylene glycol is 15% by weight or less. 14. The addition amount of the substance represented by the formula (I) is 0.
The ink according to claim 5, wherein the content is 5% by weight or more and the ratio of the amount of the 1,2-alkylene glycol added is 1: 0 to 1:10. 15. The ink according to claim 7, which contains 10% by weight or less of the (di) propylene glycol monobutyl ether. 16. The addition amount of the substance represented by the formula (I) is 0.5% by weight or more, and the ratio of (di) propylene glycol monobutyl ether is 1: 0 to 1:10. The ink according to claim 7. 17. The ink according to claim 7, which contains 20% by weight or less of the di (tri) ethylene glycol monobutyl ether. 18. The addition amount of the substance represented by the formula (I) is 0.5% by weight or more, and the ratio with the di (tri) ethylene glycol monobutyl ether is 1: 0 to 1:10. The ink according to claim 7.