JP2008284874A - Ink media set and ink cartridge, ink recording object, ink-jet recording method, and ink-jet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink media set and ink cartridge which has no problem in a drying rate, and a clear and quality picture near to a printed matter is obtained in a smooth handling sheet which has a low water absorption capacity, and to provide an ink recording object, an ink-jet recording method, and an ink-jet recording device. <P>SOLUTION: The ink media set includes ink and media for recording, wherein the water-soluble organic solvent of the ink contains 0.1-10 mass% of at least a sort chosen from a glycol ether compound expressed by general formula (I) R<SP>1</SP>-(OR<SP>2</SP>)<SB>m</SB>-OH, and when carrying out the dropping of 1 μ liter of the ink on the recording surface of the media for recording, the drying time at 23°C under 50%RH (relative humidity) environment is less than 18 minutes. In the formula, R<SP>1</SP>represents any one of a 1-8C alkyl group, allyl group, and aryl group which may have a branch, R<SP>2</SP>represents any one of an ethyl group and isopropyl group, and m represents an integer of 1-4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ink media set comprising an ink capable of recording a high-quality image by an ink jet recording method, a recording medium, and a pretreatment liquid, an ink cartridge using the ink media set, an ink recorded matter, The present invention relates to an ink jet recording method and an ink jet recording apparatus.

  The ink jet recording method is a method of performing printing by causing small droplets of ink to fly and adhere to a recording medium such as paper. As the ink used in this ink jet recording method, generally, a colorant of various dyes or pigments is dissolved or dispersed in water or water and a wetting agent. Such a wetting agent contributes to prevention of drying of the nozzle due to its water retention capacity. However, when printing on paper having a high penetration rate, for example, plain paper, the wetting agent is difficult to evaporate, so that there is a drawback in that the back-through increases.

  Therefore, in order to solve such a problem, a white pigment is applied to a recording medium or a surface on which a material for fixing a dye in the ink is applied in advance when an image is formed on the surface of the recording medium such as plain paper. And recording media coated with a water-soluble polymer have been proposed (see, for example, Patent Document 1, Patent Document 2, Patent Document 3, Patent Document 4, Patent Document 5, etc.). These proposals all relate to a recording medium subjected to special processing, and cannot be applied to a general recording medium such as plain paper. For this reason, for example, Patent Document 6 discloses an inkjet in which a polymer solution such as carboxymethylcellulose, polyvinyl alcohol, and polyvinyl acetate is jetted onto a recording medium in advance, and then ink is jetted onto a portion where the polymer solution is adhered to perform printing. A recording method has been proposed. However, in the polymer solution described in Patent Document 6, feathering was not suppressed and water resistance was not improved.

  In addition, an ink jet recording in which a pretreatment liquid of a recording medium containing a compound that insolubilizes a dye in the ink is deposited on the recording medium by an ink jet method, and then ink is ejected onto a portion of the recording medium to which the pretreatment liquid has adhered. Methods have been proposed (see Patent Document 7, Patent Document 8, Patent Document 9, etc.). However, even in these proposed methods, in order to stably eject the pretreatment liquid, it is necessary to lower the viscosity of the pretreatment liquid. For this reason, it is necessary to reduce the concentration of the compound that insolubilizes the dye. In order to obtain a sufficient image quality improvement effect in such a pretreatment liquid, it is necessary to apply a relatively large amount of the pretreatment liquid. There is also a problem that the amount of moisture adhering to the area is large, and not only cockling but also ink penetration is large.

  Also proposed is an image forming method in which a colorless liquid composition containing at least a silicone compound such as silicone oil and a cationic compound is applied to a recording medium, and then a recording ink containing an anionic component is adhered by an ink jet recording method. (See Patent Document 10). However, in this proposal, the area where the silicone compound adheres has extremely low ink permeability, so the drying of the image area is slow, and when high-speed printing is performed by this image forming method, in addition to low penetration, the recording medium becomes wet. There is a problem in that the image quality is remarkably deteriorated, for example, the adjacent dots are coalesced and white stripes are generated in the solid image portion along the head main scanning direction. In addition, the colorless liquid composition has a problem that when it is stored for a long period of time, the silicone oil is decomposed or phase separation occurs, and stable recording characteristics cannot be obtained.

  Further, after applying a colorless or light-colored image recording promoting liquid containing a colorant and a compound that insolubilizes the colorant in the ink composed of a solvent for dispersing or dissolving the colorant to the recording medium, the ink is There has been proposed an image recording method in which an image recording promoting liquid contains a predetermined surfactant that is ejected as droplets and attached to a recording medium (see Patent Document 11). According to this method, since the surfactant in the image recording promoting liquid improves the permeability and wettability, the drying property of the image is improved, and high-speed recording can be supported. However, there are cases where the penetration of the coloring material into the paper by the surfactant is promoted, and further improvement has been demanded from the fear of an increase in see-through, a decrease in image density, and occurrence of feathering.

On the other hand, when an image is recorded with water-based inkjet ink on paper with a small water absorption capacity such as coated paper for general printing such as art paper, gloss paper, etc., the wetting agent does not easily evaporate, so it takes a lot of time for drying. Is not practical. Furthermore, since the ink absorbency is slow, bleeding and beading occurred on the paper surface.
Therefore, it is desirable to provide an ink jet recording method that is quick to dry even on printing paper as described above, has high image density and saturation, has high image quality on plain paper, and does not clog nozzles even when stopped for a long time. It is rare.

For example, Patent Document 12 proposes the addition of a nonionic surfactant that defines an HLB value suitable for inkjet printing on an offset medium. However, the addition of the surfactant alone does not provide sufficient permeability and drying on the offset medium, and it is difficult to form high-quality images at high speed.
Further, Patent Document 13 proposes that the adhesion tension is defined for improving the fixability of water-based pigment ink to a recording material, but this is for plain paper without a coating layer, and offset. There is no description when printing on coated paper.
Patent Document 14 proposes the addition of a specified aprotic polar solvent as a suitable aqueous inkjet ink composition on the offset coating medium. However, in this proposal, the resin is not contained in the ink, so that the fixability of the image is inferior particularly when the pigment ink is used.
Further, Patent Document 15 proposes to add a prescribed good solvent and poor solvent for a pigment as a water-soluble organic solvent of an aqueous pigment ink composition in order to widen pixels with a small ink droplet amount. However, in this proposal, ink is specified for copy paper, and there is no description for printing paper with poor water-based ink absorption.

  Therefore, even on a smooth printing paper having a low water absorption capacity, there is no problem in the drying speed, and an ink media set that provides a clear and close-to-printed image, and an ink cartridge, an ink recorded matter using the ink media set, As for the ink jet recording method and the ink jet recording apparatus, there are currently no products having sufficiently satisfactory performance.

JP-A-56-86789 JP-A-55-144172 Japanese Patent Laid-Open No. 55-81992 JP 52-53012 A JP-A-56-89594 JP-A-56-89595 JP-A-64-63185 JP-A-8-20159 Japanese Patent Laid-Open No. 8-20161 JP-A-8-142500 JP-A-10-250216 JP-T-2004-510028 Japanese Patent No. 3733149 JP 2003-26879 A JP 2006-45514 A

  An object of the present invention is to solve various problems in the prior art and achieve the following objects. That is, the present invention relates to a smooth printing paper having a low water absorption capacity, an ink capable of obtaining a clear and high-quality image close to printed matter, a recording medium, and a pretreatment liquid. It is an object of the present invention to provide an ink media set, and an ink cartridge, an ink recorded matter, an ink jet recording method, and an ink jet recording apparatus using the ink media set.

Means for solving the problems are as follows. That is,
<1> an ink containing at least a colorant, a water-dispersible resin, a water-soluble organic solvent, a surfactant, and water;
A support and a recording medium having a coating layer containing at least a pigment and a binder on the support;
The water-soluble organic solvent contains 0.1 to 10% by mass of at least one selected from glycol ether compounds represented by the following general formula (I):
The ink media set according to claim 1, wherein the drying time is 23 minutes at a temperature of 23 ° C. and 50% RH when 1 μl of the ink is dropped on the recording surface of the recording medium.
<General formula (I)>
_{^{R 1 - (OR 2) m}} -OH
In the general formula (I), R ¹ represents an alkyl group having 1 to 8 carbon atoms which may be branched, represent any of the allyl group and an aryl group. R ² represents either an ethyl group or an isopropyl group. m represents an integer of 1 to 4.
<2> The ink media set according to <1>, wherein a critical surface tension based on JIS K6768 on the recording surface of the recording medium is 25 mN / m to 40 mN / m.
<3> a dynamic scanning liquid absorption meter transfer amount is ^2ml / ^{m 2 ~35ml} / m 2 of the recording surface of the recording medium of pure water at the contacting time 100ms measured by, and pure water at a contact time 400ms an ink media set according the transfer amount of the recording surface of the recording medium is ^3ml / ^{m 2 ~40ml} / m 2 to any one of <1> to <2>.
<4> The J.M. TAPPI No. The ink media set according to any one of <1> to <3>, wherein the smoothness based on 5B is 200 seconds to 20,000 seconds.
<5> The ink media set according to any one of <1> to <4>, wherein the pigment in the coating layer contains any one of kaolin, talc, and calcium carbonate.
<6> The surfactant in the ink is at least one selected from silicone surfactants and fluorosurfactants, and the content of the surfactant is 0.01% by mass to 5% by mass. The ink media set according to any one of <1> to <5>.
<7> The water-soluble organic solvent in the ink according to any one of <1> to <6>, including at least one selected from glycerin, 1,3-butanediol, 2-pyrrolidone, and dipropylene glycol. Ink media set.
<8> The above <1> to <7>, wherein the water-dispersible resin in the ink contains resin fine particles, the resin fine particles are acrylic silicone resin fine particles, and the glass transition temperature of the acrylic silicone resin is 25 ° C. or lower. The ink media set according to any one of the above.
<9> The ink media set according to <8>, wherein the volume average particle diameter of the resin fine particles in the resin emulsion is 10 to 1,000 nm.
<10> The above <1> to <9, wherein the colorant in the ink includes a pigment having at least one hydrophilic group on the surface and exhibiting at least one of water dispersibility and water solubility in the absence of a dispersant. The ink media set according to any of the above.
<11> The total content of the colorant and the water-dispersible resin in the ink is 10% by mass to 35% by mass, and the content of the colorant of the water-dispersible resin and the total content of the water-dispersible resin is 70 The ink media set according to any one of <1> to <10>, wherein the ink media set is from mass% to 95 mass%.
<12> An ink cartridge, wherein the ink in the ink media set according to any one of <1> to <11> is contained in a container.
<13> An inkjet recording method using the ink media set according to any one of <1> to <11>,
An ink jet recording method comprising at least an ink flying step of applying a stimulus to ink in the ink media set according to an image signal and flying the ink to record an image on a recording medium.
<14> The inkjet recording method according to <13>, wherein the stimulus is at least one selected from heat, pressure, vibration, and light.
<15> The above-mentioned <13, in which ink is ejected from a nozzle, and a droplet ejected from the nozzle has a size of 2 to 40 pl, a velocity of 6 to 20 m / s, a frequency of 1 kHz or more, and a resolution of 300 dpi or more. > To <14>.
<16> The amount of ink droplets ejected from the nozzle (M; pl) and the pixel diameter (D; μm) on the recording medium are expressed by the following equation: 18 × M ^0.43 ≦ D ≦ 35 × The inkjet recording method according to <15>, wherein M ^0.32 is satisfied.
<17> An inkjet recording apparatus using the ink media set according to any one of <1> to <11>,
An ink jet recording apparatus comprising at least ink flying means for applying a stimulus to an ink in the ink media set according to an image signal and flying the ink to record an image on a recording medium.
<18> The inkjet recording apparatus according to <17>, wherein the stimulus is at least one selected from heat, pressure, vibration, and light.
<19> An ink recorded matter comprising: an ink media set according to any one of <1> to <11>, and an image formed using ink on a recording medium. is there.

The ink media set of the present invention includes an ink containing at least a colorant, a water-dispersible resin, a water-soluble organic solvent, a surfactant, and water,
A support and a recording medium having a coating layer containing at least a pigment and a binder on the support;
The water-soluble organic solvent contains 0.1 to 10% by mass of at least one selected from glycol ether compounds represented by the following general formula (I):
The drying time in an environment of 23 ° C. and 50% RH when 1 μl of the ink is dropped on the recording surface of the recording medium is within 18 minutes.
<General formula (I)>
_{^{R 1 - (OR 2) m}} -OH
In the general formula (I), R ¹ represents an alkyl group having 1 to 8 carbon atoms which may be branched, represent any of the allyl group and an aryl group. R ² represents either an ethyl group or an isopropyl group. m represents an integer of 1 to 4.
In the ink media set of the present invention, when 1 μl of the ink is dropped onto the recording surface of the recording medium, the drying time in a 23 ° C., 50% RH environment is within 18 minutes, thereby A smooth printing paper with low image quality has no problem in drying speed, and a clear and high-quality image close to printed matter can be obtained.

The inkjet recording method of the present invention uses the ink media set of the present invention,
It includes at least a step of applying a stimulus to the ink in the ink media set in accordance with an image signal and causing the ink to fly to record an image on a recording medium. As a result, a smooth printing paper having a low water absorption capability has no problem with the drying speed, and a clear and high-quality image close to the printed matter is possible.

The inkjet recording apparatus of the present invention uses the ink media set of the present invention,
At least means for applying a stimulus to the ink in the ink media set according to an image signal and causing the ink to fly to record an image on a recording medium. As a result, a smooth printing paper having a low water absorption capability has no problem in drying speed, and a clear and high-quality image close to a printed matter can be formed.

  According to the present invention, an ink that can solve conventional problems, has a low water-absorbing ability, has a problem in drying speed, and can obtain a clear and high-quality image close to a printed matter, and recording. And an ink cartridge using the ink media set, an ink record, an ink jet recording method, and an ink jet recording apparatus.

(Ink media set)
The ink media set of the present invention includes ink and a recording medium, and further includes other configurations as necessary.

In the ink media set of the present invention, when 1 μl of the ink is dropped on the recording surface of the recording medium, the drying time in a 23 ° C., 50% RH environment is within 18 minutes, preferably within 15 minutes. . If the drying time exceeds 18 minutes, there is a high possibility that beading or blurring of color boundaries will occur on the image due to poor drying.
Here, the drying time refers to recording at a temperature of 23 ° C. and 50% RH by evaporation or solvent penetration into the recording medium from the time when 1 μl of ink is dropped on the recording surface of the recording medium. It means the time until the ink solvent does not exist as droplets on the surface of the medium.
The fact that the ink solvent no longer exists as droplets on the surface of the recording medium can be confirmed, for example, by pressing a filter paper against the surface of the recording medium on which the ink has been dropped to stop transferring.

<Ink>
The ink contains at least a colorant, a water-dispersible resin, a water-soluble organic solvent, a surfactant, and water, and further contains other components as necessary.

-Water-soluble organic solvent-
The water-soluble organic solvent contains at least a glycol ether compound and, if necessary, a wetting agent.

The glycol ether compound functions as a penetrant. The glycol ether compound is represented by the following general formula (I).
<General formula (I)>
_{^{R 1 - (OR 2) m}} -OH
In the general formula (I), R ¹ represents an alkyl group having 1 to 8 carbon atoms which may be branched, represent any of the allyl group and an aryl group. R ² represents either an ethyl group or an isopropyl group. m represents an integer of 1 to 4.

  Examples of the glycol ether compound represented by the general formula (I) include ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, and tetraethylene. Examples include polyhydric alcohol alkyl ethers such as glycol monomethyl ether and propylene glycol monoethyl ether; polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether. These may be used individually by 1 type and may use 2 or more types together. Among these, ethylene glycol monohexyl ether is particularly preferable.

  The content of the glycol ether compound in the ink is not particularly limited and may be appropriately selected depending on the purpose. It is preferably 0.1% by mass to 10% by mass, and 0.5% by mass to 10% by mass. More preferred. When the content is less than 0.1% by mass, it may take time to dry the ink on paper having a small water absorption capacity. When the content exceeds 10% by mass, the colorant in the ink and the water-dispersible resin May cause dispersion failure.

The wetting agent is added for the purpose of preventing clogging of the nozzles of the recording head due to drying.
The wetting agent is not particularly limited and may be appropriately selected depending on the intended purpose.For example, polyhydric alcohols, polyhydric alcohol alkyl ethers, polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, Examples include amides, amines, sulfur-containing compounds, propylene carbonate, and ethylene carbonate. These may be used alone or in combination of two or more.
Examples of the polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 1,3-propanediol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2-methyl-2,4-pentanediol, Examples include tetraethylene glycol, polyethylene glycol, glycerin, 1,2,6-hexanetriol, 1,2,4-butanetriol, 1,2,3-butanetriol, and petriol.
Examples of the polyhydric alcohol alkyl ethers include ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether and the like. It is done.
Examples of the polyhydric alcohol aryl ethers include ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.
Examples of the nitrogen-containing heterocyclic compound include N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethylimidazolidinone, and ε-caprolactam.
Examples of the amides include formamide, N-methylformamide, N, N-dimethylformamide and the like.
Examples of the amines include monoethanolamine, diethanolamine, triethanolamine, monoethylamine, diethylamine, and triethylamine.
Examples of the sulfur-containing compounds include dimethyl sulfoxide, sulfolane, thiodiethanol, thiodiglycol and the like.

  Among the compounds exemplified above, as the wetting agent, glycerin, 1,3-butanediol, 2-pyrrolidone, from the viewpoint of obtaining excellent effects on solubility and prevention of poor jetting properties due to water evaporation And at least one selected from dipropylene glycol is particularly preferably used.

  The content of the wetting agent in the ink is preferably 10% by mass to 50% by mass, and more preferably 20% by mass to 35% by mass. If the content is too small, the nozzle is likely to be dried and defective ejection of droplets may occur. If the content is too large, the ink viscosity is increased, and the proper viscosity range may be exceeded.

-Water dispersible colorant-
As the colorant, any of pigments and dyes can be used, and these can be used in combination. Currently, anionic dyes or pigments are used in general inkjet inks. In the present invention, the composition of the ink to be used is not limited, but it is most effective to use a combination of a commonly used ink using an anionic color material and a pretreatment liquid containing a cationic compound. .
The anionic component in the ink is at least one colorant selected from an anionic dye, a pigment or dye dispersed with an anionic dispersant, a pigment having an anionic group, and anionic colored fine particles. Since the colorant has an anionic group as a functional group, or the anionic component is adsorbed to the colorant, the coloring component in the ink is changed by the reaction between the anionic component and the cationic resin. It is possible to efficiently stay on the surface layer of the recording medium, and various image quality improvement effects such as image density improvement, back-through density reduction, feathering, and border blurring are obtained. Among these, in particular, when an anionic dye is used, the dye is fixed in the vicinity of the media surface due to the effect of the pretreatment liquid, and therefore, it can be suitably used.

-Pigment-
There is no restriction | limiting in particular as said pigment, According to the objective, it can select suitably, Any of an inorganic pigment and an organic pigment may be sufficient, and these pigments may mix and use multiple types.
Examples of the organic pigment include azo, phthalocyanine, anthraquinone, quinacridone, dioxazine, indigo, thioindigo, perylene, isoindolenone, aniline black, azomethine, rhodamine B lake, and carbon black. Can be mentioned.
Examples of the inorganic pigment include iron oxide, titanium oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, bitumen, cadmium red, chrome yellow, and metal powder.

  The particle diameter of these pigments is preferably 0.01 μm to 0.30 μm. If the particle size is less than 0.01 μm, the particle size approaches that of the dye, so that light resistance and feathering may be deteriorated. If it exceeds 0.30 μm, clogging of the discharge port or in the printer The filter may be clogged, and discharge stability may not be obtained.

There is no restriction | limiting in particular as a color of the said pigment, According to the objective, it can select suitably, For example, the thing for black, the thing for color, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.
Examples of the black color include carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, copper, iron (CI pigment black 11), oxidation, and the like. Examples thereof include metals such as titanium, organic pigments such as aniline black (CI pigment black 1), and the like.
The carbon black used in the black pigment ink is not particularly limited and can be appropriately selected according to the purpose. However, the carbon black is produced by the furnace method and the channel method, and has a primary particle size of 15 nm to 40 nm. , BET specific surface area ^{is, 50m 2 / g~300m 2 / g} , DBP oil absorption amount, 40ml / 100g~150ml / 100g, volatile content of 0.5% to 10%, which pH has 2-9 Is preferred. As such carbon black, a commercially available product can be used. 2300, no. 900, MCF-88, no. 33, no. 40, no. 45, no. 52, MA7, MA8, MA100, no. 2200B (all manufactured by Mitsubishi Chemical Corporation); Raven700, 5750, 5250, 5000, 3500, 1255 (all manufactured by Columbia); Regal400R, 330R, 660R, MoguL, Monarch700, 800, 880, 900, 1000, 1100, 1300, Monarch 1400 (all manufactured by Cabot Corporation); Color Black FW1, FW2, FW2V, FW18, FW200, S150, S160, S170, Printex 35, U, V, 140U, 140V, Special Black 6, 5, 4A, and 4 (all manufactured by Degussa).

For the color, for yellow ink, for example, C.I. I. Pigment Yellow 1 (Fast Yellow G), 3, 12 (Disazo Yellow AAA), 13, 14, 17, 23, 24, 34, 35, 37, 42 (Yellow Iron Oxide), 53, 55, 74, 81, 83 (Disazo Yellow HR), 95, 97, 98, 100, 101, 104, 108, 109, 110, 117, 120, 128, 138, 150, 153, and the like.
For magenta, for example, C.I. I. Pigment Red 1, 2, 3, 5, 17, 22 (Brilliant First Scarlet), 23, 31, 38, 48: 2 (Permanent Red 2B (Ba)), 48: 2 (Permanent Red 2B (Ca)), 48 : 3 (Permanent Red 2B (Sr)), 48: 4 (Permanent Red 2B (Mn)), 49: 1, 52: 2, 53: 1, 57: 1 (Brilliant Carmine 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81 (Rhodamine 6G Lake), 83, 88, 92, 101 (Bengara), 104, 105, 106, 108 (Cadmium Red), 112, 114, 122 (Dimethylquinacridone), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 185, 190, 193, 209, 2 9, and the like.
For cyan, for example, C.I. I. Pigment Blue 1, 2, 15 (copper phthalocyanine blue R), 15: 1, 15: 2, 15: 3 (phthalocyanine blue G), 15: 4, 15: 6 (phthalocyanine blue E), 16, 17: 1, 56, 60, 63 and the like.
Further, as intermediate colors, for red, green and blue, for example, C.I. I. Pigment red 177, 194, 224, C.I. I. Pigment orange 43, C.I. I. Pigment violet 3, 19, 23, 37, C.I. I. Pigment green 7, 36, and the like.

The pigments listed above can be made into ink jet inks by dispersing them in an aqueous medium using a polymer dispersant or a surfactant. As a dispersant for dispersing such organic pigment powder, a normal water-soluble resin and a water-soluble surfactant can be used.
Examples of the water-soluble resin include styrene, styrene derivatives, vinylnaphthalene derivatives, aliphatic alcohol esters of α, β-ethylenically unsaturated carboxylic acids, etc .; acrylic acid, acrylic acid derivatives, maleic acid, maleic acid derivatives, itaconic acid , Block copolymers composed of at least two monomers selected from itaconic acid derivatives, fumaric acid, fumaric acid derivatives and the like, random copolymers, or salts thereof. These water-soluble resins are alkali-soluble resins that are soluble in an aqueous solution in which a base is dissolved, and among these, those having a mass average molecular weight of 3,000 to 20,000 are used for inkjet inks. The dispersion is particularly preferred because it has the advantage that the viscosity of the dispersion can be lowered and the dispersion is easy.

Further, the simultaneous use of the polymer dispersant and the self-dispersing pigment is a preferable combination because an appropriate dot diameter can be obtained. The reason is not clear, but it is thought as follows.
By containing the polymer dispersant, the penetration into the recording paper is suppressed. On the other hand, since the aggregation of the self-dispersing pigment is suppressed by containing the polymer dispersant, the self-dispersing pigment can smoothly spread in the lateral direction. Therefore, it is considered that the dots spread widely and thinly and ideal dots can be formed.
Moreover, the following are mentioned as a specific example of the water-soluble surfactant which can be used as a dispersing agent by this invention. For example, anionic surfactants include higher fatty acid salts, alkyl sulfates, alkyl ether sulfates, alkyl ester sulfates, alkyl aryl ether sulfates, alkyl sulfonates, sulfosuccinates, alkyl allyls and alkyl naphthalene sulfonic acids. Examples thereof include salts, alkyl phosphates, polyoxyethylene alkyl ether phosphate esters, and alkyl allyl ether phosphates. Examples of the cationic surfactant include alkylamine salts, dialkylamine salts, tetraalkylammonium salts, benzalkonium salts, alkylpyridinium salts, imidazolinium salts, and the like. Furthermore, examples of the amphoteric surfactant include dimethylalkyl lauryl betaine, alkyl glycine, alkyl di (aminoethyl) glycine, imidazolinium betaine and the like. Nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene polyoxypropylene glycol, glycerin ester, sorbitan ester, sucrose ester, glycerin ester polyoxyethylene ether, sorbitan Examples thereof include polyoxyethylene ethers of esters, polyoxyethylene ethers of sorbitol esters, fatty acid alkanolamides, polyoxyethylene fatty acid amides, amine oxides, and polyoxyethylene alkylamines.

In addition, the pigment can be provided with dispersibility by coating with a resin having a hydrophilic group and encapsulating the pigment.
As a method of coating a water-insoluble pigment with an organic polymer and microencapsulating, all conventionally known methods can be used. Conventionally known methods include chemical production methods, physical production methods, physicochemical methods, mechanical production methods, and the like. Specifically, the following methods are mentioned.
(1) Interfacial polymerization method (a method in which two kinds of monomers or two kinds of reactants are dissolved separately in a dispersed phase and a continuous phase, and both substances are reacted at the interface between them to form a wall film)
(2) In-situ polymerization method (liquid or gas monomer and catalyst, or two types of reactive substances are supplied from either one of the continuous phase core particles to cause a reaction to form a wall film)
(3) Liquid-cured coating method (method of forming a wall film by insolubilizing droplets of a polymer solution containing core material particles in a liquid with a curing agent)
(4) Coacervation (phase separation) method (a method in which a polymer dispersion in which core material particles are dispersed is separated into a coacervate (concentrated phase) having a high polymer concentration and a dilute phase to form a wall membrane)
(5) In-liquid drying method (preparing a liquid in which a core substance is dispersed in a solution of a wall membrane material, placing the dispersion in a liquid in which the continuous phase of this dispersion is not miscible to form a composite emulsion, Method of forming a wall film by gradually removing the dissolved medium)
(6) Melt-dispersed cooling method (using a wall film material that melts into a liquid state when heated and solidifies at room temperature, this material is heated and liquefied, core material particles are dispersed therein, and it is cooled to fine particles. A method of forming a wall film)
(7) Air suspension coating method (powder core material particles are suspended in the air by a fluidized bed, and the wall membrane material coating solution is sprayed and mixed while suspended in the air stream to form a wall membrane. Method)
(8) Spray drying method (method of spraying the encapsulated stock solution and bringing it into contact with hot air to evaporate and dry the volatile matter to form a wall film)
(9) Acid precipitation method (by neutralizing at least a part of the anionic group of the organic polymer compound containing an anionic group with a basic compound to provide solubility in water in an aqueous medium together with a coloring material) After kneading, make neutral or acidic with an acidic compound, deposit organic compounds and fix them on the colorant, and then neutralize and disperse)
(10) Phase inversion emulsification method (a mixture containing an anionic organic polymer having dispersibility in water and a colorant is used as an organic solvent phase, and water is added to the organic solvent phase or water The method of charging the organic solvent phase into

Examples of the organic polymer (resin) used as the material constituting the wall membrane material of the microcapsule include polyamide, polyurethane, polyester, polyurea, epoxy resin, polycarbonate, urea resin, melamine resin, phenol resin, Sugar, gelatin, gum arabic, dextran, casein, protein, natural rubber, carboxypolymethylene, polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, cellulose, ethyl cellulose, methyl cellulose, nitrocellulose, hydroxyethyl cellulose, Cellulose acetate, polyethylene, polystyrene, (meth) acrylic acid polymer or copolymer, (meth) acrylic acid ester polymer or copolymer, (meth) acrylic acid (Meth) acrylic acid ester copolymer, styrene- (meth) acrylic acid copolymer, styrene-maleic acid copolymer, sodium alginate, fatty acid, paraffin, beeswax, water wax, hardened beef tallow, carnauba wax, albumin, etc. .
Among these, organic polymers having an anionic group such as a carboxylic acid group or a sulfonic acid group can be used. Nonionic organic polymers include, for example, polyvinyl alcohol, polyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate, methoxypolyethylene glycol monomethacrylate or their (co) polymers, and 2-oxazoline cationic ring-opening polymers. Is mentioned. In particular, a complete saponified product of polyvinyl alcohol is particularly preferable because it has low water solubility and is easily dissolved in hot water but difficult to dissolve in cold water.

  Further, the amount of the organic polymer constituting the wall membrane material of the microcapsule is preferably 1% by mass to 20% by mass with respect to a water-insoluble colorant such as an organic pigment or carbon black. By setting the amount of the organic polymer within the above range, the content of the organic polymer in the capsule is relatively low, so that the color development of the pigment is caused by the organic polymer covering the pigment surface. It becomes possible to suppress the fall of property. If the amount of the organic polymer is less than 1% by mass, it may be difficult to exert the effect of encapsulation, and if it exceeds 20% by mass, the color developability of the pigment may be significantly reduced. In consideration of other characteristics, the amount of the organic polymer is preferably in the range of 5% by mass to 10% by mass with respect to the water-insoluble colorant. That is, since a part of the color material is exposed without being substantially covered, it is possible to suppress a decrease in color developability, and conversely, a part of the color material is not exposed and is substantially not exposed. Since it is coated, it is possible to simultaneously exhibit the effect that the pigment is coated. Further, the number average molecular weight of the organic polymers used in the present invention is preferably 2,000 or more from the viewpoint of capsule production. Here, “substantially exposed” means not the partial exposure associated with defects such as pinholes and cracks, but a state where it is intentionally exposed.

Furthermore, if an organic pigment or self-dispersing carbon black, which is a self-dispersing pigment, is used as a colorant, the dispersibility of the pigment is improved even when the content of the organic polymer in the capsule is relatively low. Furthermore, it is more preferable because sufficient storage stability of the ink can be ensured.
It is preferable to select an organic polymer suitable for the microencapsulation method. For example, in the case of interfacial polymerization, polyester, polyamide, polyurethane, polyvinyl pyrrolidone, epoxy resin and the like are suitable. In the case of in-situ polymerization method, a polymer or copolymer of (meth) acrylic acid ester, (meth) acrylic acid- (meth) acrylic acid ester copolymer, styrene- (meth) acrylic acid copolymer Polyvinyl chloride, polyvinylidene chloride, polyamide and the like are suitable. In the case of the in-liquid curing method, sodium alginate, polyvinyl alcohol, gelatin, albumin, epoxy resin and the like are suitable. In the case of the coacervation method, gelatin, celluloses, casein and the like are suitable. Moreover, in order to obtain a fine and uniform microencapsulated pigment, it is possible to use all conventionally known encapsulation methods other than the above.

  When the phase inversion method or the acid precipitation method is selected as the microencapsulation method, anionic organic polymers are used as the organic polymers constituting the wall membrane material of the microcapsules. The phase inversion method is a composite or composite of an anionic organic polymer having self-dispersibility or solubility in water and a colorant such as a self-dispersion organic pigment or self-dispersion carbon black, or a self-dispersion method. A mixture of a colorant such as a dispersible organic pigment or self-dispersing carbon black, a curing agent, and an anionic organic polymer is used as an organic solvent phase, and water is added to the organic solvent phase or the organic solvent is submerged in water. In this method, a solvent phase is introduced and microencapsulation is performed while self-dispersion (phase inversion emulsification) is performed. In the above phase inversion method, there is no problem even if an ink vehicle and additives are mixed in the organic solvent phase. In particular, it is more preferable to mix an ink liquid medium because a dispersion liquid for ink can be directly produced.

On the other hand, in the acid precipitation method, a part or all of the anionic group of the anionic group-containing organic polymer is neutralized with a basic compound, and a colorant such as a self-dispersing organic pigment or self-dispersing carbon black, A water-containing cake obtained by a production method comprising a step of kneading in an aqueous medium and a step of neutralizing and acidifying an acidic compound to precipitate an anionic group-containing organic polymer and fixing it to a pigment, This is a method of microencapsulation by neutralizing part or all of an anionic group using a compound. By doing in this way, the aqueous dispersion containing the anionic microencapsulated pigment which is fine and contains many pigments can be manufactured.
Examples of the solvent used for the microencapsulation as described above include alkyl alcohols such as methanol, ethanol, propanol and butanol; aromatic hydrocarbons such as benzol, toluol and xylol; methyl acetate Esters such as ethyl acetate and butyl acetate; Chlorinated hydrocarbons such as chloroform and ethylene dichloride; Ketones such as acetone and methyl isobutyl ketone; Ethers such as tetrahydrofuran and dioxane; Cellosolves such as methyl cellosolve and butyl cellosolve Etc. The microcapsules prepared by the above method are once separated from these solvents by centrifugation or filtration, and then stirred and redispersed with water and necessary solvents to obtain the desired ink. The average particle size of the encapsulated pigment obtained by the above method is preferably 50 nm to 180 nm.
By coating the resin in this way, the pigment adheres firmly to the recording medium, so that the scratching property of the ink recorded matter can be improved.

As the dye, those having excellent water resistance and light resistance, which are classified into acid dyes, direct dyes, basic dyes, reactive dyes, and food dyes in the color index, are used. These dyes may be used as a mixture of a plurality of types, or may be used as a mixture with other colorants such as pigments as necessary.
(A) Examples of acid dyes and food dyes include C.I. I. Acid Yellow 17, 23, 42, 44, 79, 142; C.I. I. Acid Red 1, 8, 13, 14, 18, 26, 27, 35, 37, 42, 52, 82, 87, 89, 92, 97, 106, 111, 114, 115, 134, 186, 249, 254 289; I. Acid Blue 9, 29, 45, 92, 249; I. Acid Black 1, 2, 7, 24, 26, 94; I. Food Yellow 3, 4; I. Food Red 7, 9, 14; C.I. I. Food black 1, 2 etc. are mentioned.
(B) Examples of the direct dye include C.I. I. Direct yellow 1, 12, 24, 26, 33, 44, 50, 86, 120, 132, 142, 144; I. Direct Red 1, 4, 9, 13, 17, 20, 28, 31, 39, 80, 81, 83, 89, 225, 227; I. Direct orange 26, 29, 62, 102; I. Direct Blue 1, 2, 6, 15, 22, 25, 71, 76, 79, 86, 87, 90, 98, 163, 165, 199, 202; I. Direct black 19, 22, 32, 38, 51, 56, 71, 74, 75, 77, 154, 168, 171 and the like.
(C) Examples of basic dyes include C.I. I. Basic yellow 1, 2, 11, 13, 14, 15, 19, 21, 23, 24, 25, 28, 29, 32, 36, 40, 41, 45, 49, 51, 53, 63, 64, 65 67, 70, 73, 77, 87, 91; I. Basic Red 2, 12, 13, 14, 15, 18, 22, 23, 24, 27, 29, 35, 36, 38, 39, 46, 49, 51, 52, 54, 59, 68, 69, 70 73, 78, 82, 102, 104, 109, 112; I. Basic blue 1, 3, 5, 7, 9, 21, 22, 26, 35, 41, 45, 47, 54, 62, 65, 66, 67, 69, 75, 77, 78, 89, 92, 93 , 105, 117, 120, 122, 124, 129, 137, 141, 147, 155; I. Basic black 2, 8 etc. are mentioned.
(D) Examples of reactive dyes include C.I. I. Reactive Black 3, 4, 7, 11, 12, 17; C.I. I. Reactive Yellow 1,5,11,13,14,20,21,22,25,40,47,51,55,65,67; I. Reactive Red 1, 14, 17, 25, 26, 32, 37, 44, 46, 55, 60, 66, 74, 79, 96, 97; I. Reactive blue 1, 2, 7, 14, 15, 23, 32, 35, 38, 41, 63, 80, 95 and the like.

  The content of the colorant in the ink is preferably 6% by mass to 15% by mass, and more preferably 8-12% by mass. When the content is less than 6% by mass, the image density may be lowered due to a decrease in coloring power, or feathering or bleeding may be deteriorated due to a decrease in viscosity. If the nozzle is left unattended, the nozzles will be easy to dry, non-ejection phenomenon will occur, the viscosity will be too high, the permeability will decrease, and the dots will not spread, so the image density will decrease. Or a blurred image.

-Water dispersible resin-
The water-dispersible resin is not particularly limited and may be appropriately selected depending on the intended purpose. However, resin fine particles are preferable because the amount of the water-dispersible resin added can be increased.

The resin fine particles present as a resin emulsion dispersed in water as a continuous phase are used at the time of ink production. The resin emulsion may contain a dispersant such as a surfactant as necessary.
The content of resin fine particles as the dispersed phase component (content of resin fine particles in resin emulsion solution: not content in ink after production) is generally preferably 10% by mass to 70% by mass.
The particle diameter of the resin fine particles is preferably 10 nm to 1,000 nm, and more preferably 100 nm to 300 nm, particularly considering use in an ink jet recording apparatus. The volume average particle diameter is the particle diameter in the resin emulsion, but in the case of a stable ink, there is no significant difference between the particle diameter in the resin emulsion and the resin fine particle diameter in the ink. The larger the volume average particle diameter is, the more emulsion can be added. If the volume average particle size is less than 10 nm, the amount of emulsion added may not be increased, and if it exceeds 1,000 nm, the reliability may be lowered. However, it is not always possible to use an emulsion having a particle size outside this range. These are general trends regardless of the type of emulsion.
Here, the volume average particle diameter can be measured using, for example, a particle size analyzer (Microtrac Model UPA9340, manufactured by Nikkiso Co., Ltd.). Specifically, the emulsion aqueous solution is diluted within the optimum range of the signal level, and measured under the conditions of transparency-YES, provisionally Reflective Index 1.49, Partial Density 1.19, Spherical Particles-YES, medium-water. Here, the value of 50% was defined as the volume average particle size.

The resin particles in the dispersed phase are not particularly limited and can be appropriately selected according to the purpose. For example, urethane resin, polyester resin, acrylic resin, vinyl acetate resin, styrene resin, butadiene resin, Examples thereof include styrene-butadiene resin, vinyl chloride resin, acrylic styrene resin, acrylic silicone resin, and the like.
As said resin emulsion, what was synthesize | combined suitably may be used and a commercial item may be used.
Examples of the commercially available resin emulsion include Microgel E-1002, E-5002 (styrene-acrylic resin emulsion, manufactured by Nippon Paint Co., Ltd.), and Boncoat 4001 (acrylic resin emulsion, manufactured by Dainippon Ink & Chemicals, Inc.). ), Boncoat 5454 (styrene-acrylic resin emulsion, manufactured by Dainippon Ink & Chemicals, Inc.), SAE-1014 (styrene-acrylic resin emulsion, manufactured by Nippon Zeon Co., Ltd.), Cybinol SK-200 (acrylic resin emulsion, Seiden Chemical Co., Ltd.), Primal AC-22, AC-61 (acrylic resin emulsion, manufactured by Rohm and Haas), Nanoacryl SBCX-2821, 3689 (acrylic silicone resin emulsion, Toyo Ink Co., Ltd.) Ltd. Formula Company), # 3070 (methyl methacrylate polymer resin emulsion, manufactured by Mikuni Color Ltd.). Among these, an acrylic silicone emulsion is particularly preferable from the viewpoint of good fixability.

The glass transition temperature of the resin component in the acrylic silicone emulsion is preferably 25 ° C. or less, and more preferably 0 ° C. or less. When the glass transition temperature exceeds 25 ° C., the resin itself becomes brittle, which causes deterioration of fixability. In particular, in the case of a printing paper that is smooth and hardly absorbs water, a decrease in fixing property may appear. However, even if the glass transition temperature is 25 ° C. or higher, it cannot always be used.
The glass transition temperature can be measured using, for example, a differential scanning calorimeter (manufactured by Rigaku Corporation).
Specifically, the resin piece of the room temperature dry film of the resin emulsion aqueous solution can be obtained by raising the temperature from around −50 ° C. with a differential scanning calorimeter and determining the temperature at which the step is generated.

  The total content of the colorant and the water-dispersible resin in the ink is preferably 10% by mass to 35% by mass, and the content of the water-dispersible resin with respect to the total content is 70% by mass to 95% by mass. preferable. When the total content exceeds 35% by mass, the viscosity also increases, and there is a tendency that ejection is difficult with the current ink jet recording apparatus. However, in order to prevent bleeding, it is preferable that the total content is higher. Further, if the content of the water-dispersible resin with respect to the colorant is less than 70% by mass, the saturation of the image tends to decrease, and if it exceeds 95% by mass, the image density tends to decrease.

-Surfactant-
The surfactant is not particularly limited and can be appropriately selected from surfactants that do not impair dispersion stability depending on the purpose, depending on the type of coloring agent, a wetting agent, a penetrating agent, and the like. In particular, when printing on printing paper, those having low surface tension and high leveling properties are preferred, and at least one selected from silicone surfactants and fluorosurfactants is preferred. Among these, a fluorine-based surfactant is particularly preferable.

The fluorine-based surfactant preferably has 2 to 16 carbon atoms substituted by fluorine, and more preferably 4 to 16 carbon atoms. When the fluorine-substituted carbon number is less than 2, the effect of fluorine may not be obtained, and when it exceeds 16, problems such as ink storage stability may occur.
Examples of the fluorosurfactant include a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic compound, a perfluoroalkyl phosphate compound, a perfluoroalkyl ethylene oxide adduct, and a perfluoroalkyl ether group in the side chain. And polyoxyalkylene ether polymer compounds. Among these, a polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain is particularly preferable because of its low foaming property.

Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid, perfluoroalkyl sulfonate, and the like.
Examples of the perfluoroalkyl carboxylic compounds include perfluoroalkyl carboxylic acids and perfluoroalkyl carboxylic acid salts.
Examples of the perfluoroalkyl phosphate compound include perfluoroalkyl phosphate esters, perfluoroalkyl phosphate salts, and the like.
The polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain includes a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain, and a polyoxyalkylene ether having a perfluoroalkyl ether group in the side chain. Examples thereof include a sulfate salt of a polymer and a salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain.
As counter ions of salts in these fluorosurfactants, Li, Na, K, NH ₄ , NH ₃ CH ₂ CH ₂ OH, NH ₂ (CH ₂ CH ₂ OH) ₂ , NH (CH ₂ CH ₂ OH) ₃ etc. are mentioned.

As said fluorosurfactant, what was synthesize | combined suitably may be used and a commercial item may be used.
As this commercial item, for example, Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, S-145 (all manufactured by Asahi Glass Co., Ltd.), Fullrad FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M Limited), MegaFuck F-470, F1405, F -474 (all manufactured by Dainippon Ink & Chemicals, Inc.), Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR (all manufactured by DuPont), FT-110 , FT-250, FT-251, FT-400S, FT-150, FT-400SW (all manufactured by Neos Co., Ltd.), PF-151 Among these, FT-110, FT-250, and FT-251 made by Neos Co., Ltd. are particularly preferable in that good printing quality, particularly color development and leveling on paper are remarkably improved. FT-400S, FT-150, FT-400SW, and OM-nova PF-151N are particularly preferable.
As specific examples of the fluorosurfactant, those represented by the following structural formula are suitable.

(1) Anionic fluorosurfactant
In the structural formula, Rf represents a mixture of fluorine-containing hydrophobic groups represented by the following structural formula. A is —SO ₃ X, —COOX, or —PO ₃ X (where X is a counter anion, specifically, a hydrogen atom, Li, Na, K, NH ₄ , NH ₃ CH ₂ CH ₂ OH, , NH ₂ (CH ₂ CH ₂ OH) ₂ , or NH (CH ₂ CH ₂ OH) ₃ ).

In the structural formula, Rf ′ represents a fluorine-containing group represented by the following structural formula. X represents the same meaning as described above. n represents an integer of 1 or 2, and m represents 2-n.
However, in said structural formula, n represents the integer of 3-10.

However, in the structural formulas, Rf ′ and X have the same meaning as described above.

However, in the structural formulas, Rf ′ and X have the same meaning as described above.

(2) Nonionic fluorosurfactant
In the structural formula, Rf represents the same meaning as described above. n represents an integer of 5 to 20.

However, in the structural formula, Rf ′ represents the same meaning as described above. n represents an integer of 1 to 40.

(3) Amphoteric fluorosurfactant
However, in the structural formula, Rf represents the same meaning as described above.

(4) Oligomer type fluorosurfactant
In the structural formula, Rf ″ represents a fluorine-containing group represented by the following structural formula. N represents an integer of 0 to 10. X represents the same meaning as described above.
However, in said structural formula, n represents the integer of 1-4.

In the structural formula, Rf ″ represents the same meaning as described above. L represents an integer of 0 to 10, m represents an integer of 0 to 10, and n represents an integer of 0 to 10, respectively.

The silicone-based surfactant is not particularly limited and may be appropriately selected depending on the purpose, and preferably does not decompose even at a high pH. For example, side chain-modified polydimethylsiloxane, both-end modified polydimethylsiloxane, Examples include one-end-modified polydimethylsiloxane, side-chain both-end-modified polydimethylsiloxane, and those having a polyoxyethylene group or a polyoxyethylene polyoxypropylene group as a modifying group exhibit good properties as an aqueous surfactant. Particularly preferred.
As such a surfactant, an appropriately synthesized product or a commercially available product may be used.
Such commercially available products can be easily obtained from, for example, Big Chemie, Shin-Etsu Silicone, Toray Dow Corning Silicone, etc.

The polyether-modified silicone surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the polyalkylene oxide structure represented by the following structural formula may be represented by the side chain of Si part of dimethylpolysiloxane. And the like, and the like.
However, m, n, a, and b represent an integer in the said structural formula. R and R ′ represent an alkyl group or an alkylene group.

  A commercial item can be used as said polyether modified silicone compound, For example, KF-618, KF-642, KF643 (all are Shin-Etsu Chemical Co., Ltd. product) etc. are mentioned.

  In addition to the fluorine surfactant and the silicone surfactant, an anionic surfactant, a nonionic surfactant, an amphoteric surfactant, and the like can be used.

  Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, oxalate sulfonate, laurate, and polyoxyethylene alkyl ether sulfate salt.

Examples of the nonionic surfactant include acetylene glycol surfactants, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl esters, polyoxyethylene sorbitan fatty acid esters, and the like.
Examples of the acetylene glycol surfactant include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3,5-dimethyl-1-hexyn-3-ol and the like can be mentioned. Examples of commercially available acetylene glycol surfactants include Surfynol 104, 82, 465, 485, and TG manufactured by Air Products (USA).

Examples of the amphoteric surfactant include lauryl aminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, lauryl dihydroxyethyl betaine, lauryl dimethylamine oxide, myristyl dimethylamine oxide, stearyl dimethylamine oxide, dihydroxyethyl lauryl amine oxide, Polyoxyethylene coconut oil alkyldimethylamine oxide, dimethylalkyl (coconut) betaine, dimethyl lauryl betaine and the like can be mentioned.
Such surfactants are commercially available products such as Nikko Chemicals Co., Ltd., Nippon Emulsion Co., Ltd., Nippon Shokubai Co., Ltd., Toho Chemical Co., Ltd., Kao Co., Ltd., Adeka Co., Ltd., Lion Co., Ltd., Aoki Oil Co., Ltd., Sanyo Kasei Co., Ltd. It can be easily obtained from Kogyo Co., Ltd.
The surfactant is not limited to these, and may be used alone or in combination. Even if it does not dissolve easily in the ink alone, it can be solubilized by mixing and exist stably.

Among these surfactants, those represented by the following structural formulas (A) to (E) are preferable.
^{_{R 1 -O- (CH 2 CH 2}} O) h -R 2 ··· structural formula (A)
However, in the structural formula (A), R ¹ represents an alkyl group that may be branched having 6 to 14 carbon atoms or a perfluoroalkyl group that may be branched having 6 to 14 carbon atoms. R ² represents a hydrogen atom or an optionally branched alkyl group having 1 to 4 carbon atoms. h represents an integer of 5 to 20.

R ¹ —COO— (CH ₂ CH ₂ O) _h —R ² ... Structural formula (B)
However, the structural formula (B), R ¹ represents an alkyl group which may be branched having 6 to 14 carbon atoms. R ² represents a hydrogen atom or an optionally branched alkyl group having 1 to 4 carbon atoms. h represents an integer of 5 to 20.

In the Structural Formula (C), R ³ represents a hydrocarbon group, for example, such as an alkyl group branched carbon atoms and optionally 6-14. k represents an integer of 5 to 20.

However, the structural formula (D), R ⁴ represents a hydrocarbon group, for example, an alkyl group branched carbon atoms and optionally 6-14. L represents an integer of 5 to 10, and p represents an integer of 5 to 20. The propylene glycol chain and the ethylene glycol chain may be block polymerized or randomly polymerized.

However, q and r represent the integer of 5-20 in the said structural formula (E).

The content of the surfactant in the ink is preferably 0.01% by mass to 5% by mass, and more preferably 0.5% by mass to 2% by mass.
When the content is less than 0.01% by mass, the effect of adding the surfactant may be lost. When the content exceeds 5% by mass, the permeability to the recording medium is unnecessarily high, and the image density is increased. May be reduced or show through.

-Other ingredients-
The other components are not particularly limited and can be appropriately selected as necessary. For example, pH adjusters, antiseptic / antifungal agents, rust preventives, antioxidants, ultraviolet absorbers, oxygen absorbers, And light stabilizers.

  The pH adjusting agent is not particularly limited as long as it can adjust the pH without adversely affecting the ink to be prepared, and any substance can be used according to the purpose. Examples of the pH adjuster include amines such as diethanolamine and triethanolamine, hydroxides of alkali metal elements such as lithium hydroxide, sodium hydroxide and potassium hydroxide; ammonium hydroxide and quaternary ammonium hydroxide. Quaternary phosphonium hydroxide, alkali metal carbonates such as lithium carbonate, sodium carbonate, potassium carbonate, and the like.

  The antiseptic / antifungal agent can suppress the growth of bacteria in the ink, and can improve the storage stability and the image quality stability. Examples of the antiseptic / antifungal agent include benzotriazole, sodium dehydroacetate, sodium sorbate, isothiazoline compounds, sodium benzoate, sodium pentachlorophenol, and the like.

  The rust preventive agent can form a film on a metal surface in contact with the liquid, such as a recording head, and prevent corrosion. Examples of the rust inhibitor include acidic sulfite, sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite.

The antioxidant can prevent corrosion by eliminating radical species that cause corrosion. Examples of the antioxidant include phenol-based antioxidants (including hindered phenol-based antioxidants), amine-based antioxidants, sulfur-based antioxidants, phosphorus-based antioxidants, and the like.
Examples of the phenolic antioxidants (including hindered phenolic antioxidants) include butylated hydroxyanisole, 2,6-di-tert-butyl-4-ethylphenol, stearyl-β- (3,5 -Di-tert-butyl-4-hydroxyphenyl) propionate, 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 2,2'-methylenebis (4-ethyl-6-tert-butylphenol), 4,4′-Butylidenebis (3-methyl-6-tert-butylphenol), 3,9-bis [1,1-dimethyl-2- [β- (3-tert-butyl-4-hydroxy-5-methylphenyl) ) Propionyloxy] ethyl] 2,4,8,10-tetrixaspiro [5,5] undecane, 1,1,3-tris (2-methyl-4- Hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tetrakis [methylene-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate] methane, and the like.
Examples of the amine-based antioxidant include phenyl-β-naphthylamine, α-naphthylamine, N, N′-di-sec-butyl-p-phenylenediamine, phenothiazine, N, N′-diphenyl-p-phenylenediamine. 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butylphenol, 2,4-dimethyl-6-tert-butyl-phenol, butylhydroxyanisole, 2,2′-methylenebis ( 4-methyl-6-tert-butylphenol), 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), 4,4′-thiobis (3-methyl-6-tert-butylphenol), tetrakis [methylene -3 (3,5-di-tert-butyl-4-dihydroxyphenyl) propionate] methane, 1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, and the like.
Examples of the sulfur-based antioxidant include dilauryl 3,3′-thiodipropionate, distearyl thiodipropionate, lauryl stearyl thiodipropionate, dimyristyl 3,3′-thiodipropionate, distearyl β. , β′-thiodipropionate, 2-mercaptobenzimidazole, dilauryl sulfide and the like.
Examples of the phosphorus antioxidant include triphenyl phosphite, octadecyl phosphite, triisodecyl phosphite, trilauryl trithiophosphite, trinonyl phenyl phosphite, and the like.

Examples of the ultraviolet absorber include a benzophenone ultraviolet absorber, a benzotriazole ultraviolet absorber, a salicylate ultraviolet absorber, a cyanoacrylate ultraviolet absorber, and a nickel complex ultraviolet absorber.
Examples of the benzophenone-based ultraviolet absorber include 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-n-dodecyloxybenzophenone, 2,4-dihydroxybenzophenone, and 2-hydroxy-4-methoxybenzophenone. 2,2 ′, 4,4′-tetrahydroxybenzophenone, and the like.
Examples of the benzotriazole ultraviolet absorber include 2- (2′-hydroxy-5′-tert-octylphenyl) benzotriazole, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-4′-octoxyphenyl) benzotriazole, 2- (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) -5-chlorobenzotriazole, and the like.
Examples of the salicylate-based ultraviolet absorber include phenyl salicylate, p-tert-butylphenyl salicylate, p-octylphenyl salicylate, and the like.
Examples of the cyanoacrylate ultraviolet absorber include ethyl-2-cyano-3,3′-diphenyl acrylate, methyl-2-cyano-3-methyl-3- (p-methoxyphenyl) acrylate, and butyl-2- And cyano-3-methyl-3- (p-methoxyphenyl) acrylate.
Examples of the nickel complex-based ultraviolet absorber include nickel bis (octylphenyl) sulfide, 2,2′-thiobis (4-tert-octylferrate) -n-butylamine nickel (II), and 2,2′-thiobis. (4-tert-octyl ferrate) -2-ethylhexylamine nickel (II), 2,2′-thiobis (4-tert-octyl ferrate) triethanolamine nickel (II), and the like.

  In the ink of the ink media set of the present invention, at least a colorant, a water-soluble organic solvent, a wetting agent, and other components as necessary are dispersed or dissolved in an aqueous medium, and further stirred and mixed as necessary. Manufactured. The dispersion can be performed by, for example, a sand mill, a homogenizer, a ball mill, a paint shaker, an ultrasonic disperser, and the like. be able to.

As physical properties of the ink, for example, the viscosity, surface tension, pH, and the like are preferably in the following ranges.
The viscosity is preferably 1.0 mPa · s to 20 mPa · s at 25 ° C., and more preferably 3.0 mPa · s to 10.0 mPa · s from the viewpoint of ejection stability.
The surface tension is preferably 40 mN / m or less at 25 ° C., and more preferably 17 mN / m to 40 mN / m. When the surface tension is 40 mN / m or less, quick fixing can be performed on almost all recording media.
As said pH, 3-11 are preferable, for example, and 6-10 are more preferable from a viewpoint of the corrosion prevention of the metal member which touches.

  There is no restriction | limiting in particular as coloring of the said ink, According to the objective, it can select suitably, Yellow, magenta, cyan, black etc. are mentioned. When recording is performed using an ink set in which two or more of these colorings are used in combination, a multicolor image can be formed. When recording is performed using an ink set in which all colors are combined, a full color image is formed. be able to.

  The ink in the ink media set of the present invention is an ink jet head that uses a piezoelectric element as pressure generating means for pressurizing ink in the ink flow path, and deforms the diaphragm that forms the wall surface of the ink flow path. A so-called piezo-type device that discharges ink droplets by changing the product (see Japanese Patent Laid-Open No. 2-51734), or a so-called thermal device that generates bubbles by heating ink in an ink flow path using a heating resistor. Type (see Japanese Patent Application Laid-Open No. 61-59911), the diaphragm and the electrode forming the wall surface of the ink flow path are arranged opposite to each other, and the diaphragm is deformed by the electrostatic force generated between the diaphragm and the electrode Thus, any ink jet such as an electrostatic type that discharges ink droplets by changing the volume of the ink flow path (see JP-A-6-71882) can be used. It can be satisfactorily used in the printer for mounting a head.

<Recording media>
The recording medium includes a support and a coating layer on at least one surface of the support, and further includes other layers as necessary.

In the above recording medium, the amount of transferred to the recording medium of pure water at the contacting time 100ms measured by a dynamic scanning ^{absorptometer,} preferably ^{2ml / m 2 ~35ml / m 2} , 2ml / m 2 ~ 10 ml / m ² is more preferable.
If the amount of pure water transferred at the contact time of 100 ms is too small, beading may occur easily, and if too large, the ink dot diameter after recording may be too small than the desired diameter.
Transfer amount of said to the recording medium of pure water at the dynamic scanning absorptometer contact time measured by 400ms is ^preferably from ^{3ml / m 2 ~40ml / m 2} , more preferably 3ml / ^{m 2} ~10ml / m 2 .
If the amount of pure water transferred at the contact time of 400 ms is too small, the drying property is insufficient, and thus spur marks may be easily generated. If too much, the gloss of the image area after drying becomes low. May be easier.

  Here, the dynamic scanning absorptiometer (DSA, Papa-Pagi Technical Journal, Vol. 48, May 1994, pp. 88-92, Kuju Shigenori) absorbs liquid in a very short time. It is a device that can measure accurately. The dynamic scanning absorption meter reads the liquid absorption speed directly from the movement of the meniscus in the capillary, makes the sample a disk, and then scans the liquid absorption head in a spiral shape, and the scanning speed according to a preset pattern. Is automatically changed by a method in which the number of necessary points is measured with one sample. A liquid supply head for a paper sample is connected to a capillary via a Teflon (registered trademark) tube, and the position of the meniscus in the capillary is automatically read by an optical sensor. Specifically, the transfer amount of pure water was measured using a dynamic scanning absorption meter (K350 series D type, manufactured by Kyowa Seiko Co., Ltd.). The transfer amount at the contact time of 100 ms and the contact time of 400 ms can be obtained by interpolation from the measured value of the transfer amount at the contact time adjacent to each contact time.

The critical surface tension (γc) based on JIS K6768 on the recording surface of the recording medium is preferably 25 mN / m to 40 mN / m. When the critical surface tension (γc) is less than 25 mN / m, wetting with respect to the ink is poor and beading is likely to occur. When the critical surface tension exceeds γm / m, the dot shape of the ink becomes a perfect circle. May be difficult to keep close to.
Here, the critical surface tension (γc) is determined according to JIS K6768, 1999 “Plastic-Film and Sheet-Wetting Tension Test Methods”, various surface tension wetting tension test solutions (for example, ethylene glycol monoethyl ether and formamide). 4 microliters (μl) of liquid droplets) was dropped on the media printing surface, and the contact angle of each droplet when moving for 0.5 seconds was measured using a contact angle measurement device (produced by Data Physics). , OCA), and a Zisman Plot can be determined from the contact angle.

In the recording surface of the recording medium, J.P. TAPPI No. The smoothness based on 5B is preferably 200 to 20,000 seconds, more preferably 1,000 to 10,000 seconds. If the smoothness is less than 200 seconds, glossiness of the paper or the image may be difficult to be obtained. There is.
The smoothness is determined by J.H. TAPPI No. It is calculated based on 5B, and can be measured by, for example, the Oken type smoothness tester.

-Support-
The support is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include paper based on wood fibers, and sheet-like materials such as non-woven fabrics mainly composed of wood fibers and synthetic fibers. .

  There is no restriction | limiting in particular as said paper, According to the objective, it can select suitably according to the objective, For example, wood pulp, waste paper pulp, etc. are used. Examples of the wood pulp include hardwood bleached kraft pulp (LBKP), softwood bleached kraft pulp (NBKP), NBSP, LBSP, GP, and TMP.

  As the raw material of the used paper pulp, the white paper, ruled white, cream white, card, special white, medium white, imitation, fair white, Kent, white, as shown in the used paper standard quality standard table of the used paper recycling promotion center Art, special upper limit, another upper limit, newspaper, magazine, etc. are mentioned. Specifically, printer paper such as non-coating computer paper, thermal paper, and pressure-sensitive paper as information-related paper; OA waste paper such as PPC paper; coating of art paper, coated paper, finely coated paper, matte paper, etc. Paper: High quality paper, color quality, notebook, notepaper, wrapping paper, fancy paper, medium quality paper, newsprint, reprint paper, super paper, imitation paper, pure white roll paper, uncoated paper such as milk carton, etc. Examples of used paper and paperboard include chemical pulp paper and high-yield pulp-containing paper. These may be used individually by 1 type and may use 2 or more types together.

The waste paper pulp is generally produced from a combination of the following four steps.
(1) For disaggregation, waste paper is treated with mechanical force and chemicals with a pulper to loosen it into a fibrous form, and the printing ink is peeled off from the fiber.
(2) Dust removal removes foreign matters (plastics, etc.) and dust contained in waste paper with a screen, cleaner or the like.
(3) In the deinking, the printing ink that has been peeled off from the fiber using a surfactant is removed from the system by a flotation method or a cleaning method.
(4) Bleaching increases the whiteness of the fiber using an oxidizing action or a reducing action.
When mixing the used paper pulp, the mixing ratio of the used paper pulp in the total pulp is preferably 40% or less from the viewpoint of curling after recording.

  As the internal filler used for the support, for example, a conventionally known pigment is used as a white pigment. Examples of the white pigment include light calcium carbonate, heavy calcium carbonate, kaolin, clay, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, White inorganic pigments such as calcium silicate, magnesium silicate, synthetic silica, aluminum hydroxide, alumina, lithopone, zeolite, magnesium carbonate, magnesium hydroxide; styrene plastic pigment, acrylic plastic pigment, polyethylene, microcapsule, urea resin And organic pigments such as melamine resin. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the internally added sizing agent used for making the support include neutral rosin sizing agents used for neutral papermaking, alkenyl succinic anhydride (ASA), alkyl ketene dimer (AKD), and petroleum resins. System sizing agents and the like. Among these, a neutral rosin sizing agent or alkenyl succinic anhydride is particularly preferable. The alkyl ketene dimer may be added in a small amount because of its high size effect, but the friction coefficient on the surface of the recording paper (media) is low and slippery, which is not preferable from the viewpoint of transportability during ink jet recording. There is.

-Coating layer-
The coating layer contains a pigment and a binder (binder), and further contains a surfactant and other components as necessary.

As the pigment, an inorganic pigment or a combination of an inorganic pigment and an organic pigment can be used.
Examples of the inorganic pigment include kaolin, talc, heavy calcium carbonate, light calcium carbonate, calcium sulfite, amorphous silica, titanium white, magnesium carbonate, titanium dioxide, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, Examples thereof include zinc hydroxide and chlorite. Among these, kaolin is particularly preferable because it is excellent in glossiness and can be made close to the paper for offset printing.
The kaolin includes delaminated kaolin, calcined kaolin, engineered kaolin by surface modification, etc. In consideration of gloss expression, the particle size distribution is such that the ratio of the particle size is 2 μm or less is 80% by mass or more. It is preferable that the kaolin which has occupies 50 mass% or more of the whole kaolin.
The amount of kaolin added is preferably 50 parts by mass or more with respect to 100 parts by mass of the binder. When the addition amount is less than 50 parts by mass, a sufficient effect on glossiness may not be obtained. The upper limit of the addition amount is not particularly limited, but is preferably 90 parts by mass or less from the viewpoint of coating suitability in consideration of the fluidity of kaolin, particularly the thickening under high shear force.

Examples of the organic pigment include water-soluble dispersions such as styrene-acrylic copolymer particles, styrene-butadiene copolymer particles, polystyrene particles, and polyethylene particles. Two or more of these organic pigments may be mixed.
The addition amount of the organic pigment is preferably 2 to 20 parts by mass with respect to 100 parts by mass of the total pigment in the coating layer. Since the organic pigment is excellent in gloss expression and its specific gravity is smaller than that of an inorganic pigment, it is possible to obtain a coating layer that is bulky, high gloss, and has good surface coverage. If the addition amount is less than 2 parts by mass, the above effect is not obtained. If the addition amount exceeds 20 parts by mass, the fluidity of the coating liquid is deteriorated, leading to a decrease in coating operability, and economical in terms of cost. Not right.
The organic pigment includes a solid type, a hollow type, a donut type, and the like in terms of its form, but the average particle diameter is 0.2 in view of the balance of gloss development, surface covering property, and fluidity of the coating liquid. A hollow mold having a porosity of 40% or more is more preferable.

As the binder, an aqueous resin is preferably used.
As the aqueous resin, at least one of a water-soluble resin and a water-dispersible resin is preferably used. There is no restriction | limiting in particular as said water-soluble resin, According to the objective, it can select suitably, For example, modified products of polyvinyl alcohol, such as polyvinyl alcohol, anion modified polyvinyl alcohol, cation modified polyvinyl alcohol, acetal modified polyvinyl alcohol; Polyurethane; polyvinylpyrrolidone and polyvinylpyrrolidone and vinyl acetate copolymer, vinylpyrrolidone and dimethylaminoethyl / methacrylic acid copolymer, quaternized vinylpyrrolidone / dimethylaminoethyl / methacrylic acid copolymer, vinylpyrrolidone and Modified products of polyvinylpyrrolidone such as a copolymer of methacrylamidopropyl trimethylammonium chloride; Cellulo such as carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose Modified products of cellulose such as cationized hydroxyethyl cellulose; synthetic resins such as polyesters, polyacrylic acid (esters), melamine resins, or modified products thereof, and copolymers of polyester and polyurethane; poly (meth) acrylic acid, Examples include poly (meth) acrylamide, oxidized starch, phosphate esterified starch, self-modified starch, cationized starch, or various modified starches, polyethylene oxide, sodium polyacrylate, and sodium alginate. These may be used individually by 1 type and may use 2 or more types together.
Among these, polyvinyl alcohol, cation-modified polyvinyl alcohol, acetal-modified polyvinyl alcohol, polyester, polyurethane, a copolymer of polyester and polyurethane, and the like are particularly preferable from the viewpoint of ink absorbability.

The water-dispersible resin is not particularly limited and may be appropriately selected depending on the intended purpose. For example, polyvinyl acetate, ethylene-vinyl acetate copolymer, polystyrene, styrene- (meth) acrylate ester copolymer Polymer, (meth) acrylic acid ester polymer, vinyl acetate- (meth) acrylic acid (ester) copolymer, styrene-butadiene copolymer, ethylene-propylene copolymer, polyvinyl ether, silicone-acrylic copolymer Coalescence, etc. Further, it may contain a crosslinking agent such as methylolated melamine, methylolated urea, methylolated hydroxypropylene urea, or isocyanate, or may be a copolymer containing units such as N-methylolacrylamide and having a self-crosslinking property. A plurality of these water-based resins can be used simultaneously.
The amount of the aqueous resin added is preferably 2 parts by mass to 100 parts by mass and more preferably 3 parts by mass to 50 parts by mass with respect to 100 parts by mass of the pigment. The amount of the aqueous resin added is determined so that the liquid absorption characteristics of the recording medium fall within a desired range.

  When a water-dispersible colorant is used as the colorant, the cationic organic compound is not necessarily added, but is not particularly limited and can be appropriately selected and used depending on the purpose. For example, a primary to tertiary amine, quaternary ammonium salt monomer or oligomer that reacts with a sulfonic acid group, a carboxyl group, an amino group, or the like in a direct dye or acidic dye in water-soluble ink to form an insoluble salt. A polymer etc. are mentioned, Among these, an oligomer or a polymer is preferable.

Examples of the cationic organic compound include dimethylamine / epichlorohydrin polycondensate, dimethylamine / ammonia / epichlorohydrin condensate, poly (trimethylaminoethyl methacrylate / methyl sulfate), diallylamine hydrochloride / acrylamide copolymer, (Diallylamine hydrochloride / sulfur dioxide), polyallylamine hydrochloride, poly (allylamine hydrochloride / diallylamine hydrochloride), acrylamide / diallylamine copolymer, polyvinylamine copolymer, dicyandiamide, dicyandiamide / ammonium chloride / urea / formaldehyde condensate , Polyalkylene polyamine dicyandiamide ammonium salt condensate, dimethyl diallyl ammonium chloride, polydiallyl methylamine hydrochloride, poly (diallyl dimethyl ester) Ruammonium chloride), poly (diallyldimethylammonium chloride / sulfur dioxide), poly (diallyldimethylammonium chloride / diallylamine hydrochloride derivative), acrylamide / diallyldimethylammonium chloride copolymer, acrylate / acrylamide / diallylamine hydrochloride copolymer Products, ethyleneimine derivatives such as polyethyleneimine and acrylicamine polymer, and polyethyleneimine alkylene oxide modified products. These may be used individually by 1 type and may use 2 or more types together.
Among these, low molecular weight cationic organic compounds such as dimethylamine / epichlorohydrin polycondensate and polyallylamine hydrochloride and other relatively high molecular weight cationic organic compounds such as poly (diallyldimethylammonium chloride) It is preferable to use in combination. The combined use improves the image density and further reduces the feathering as compared with the single use.

The cation equivalent of the cationic organic compound by colloid titration method (using polyvinyl potassium sulfate and toluidine blue) is preferably 3 meq / g to 8 meq / g. If the cation equivalent is within this range, good results can be obtained within the dry adhesion range.
Here, in the measurement of the cation equivalent by the colloid titration method, the cationic organic compound is diluted with distilled water so as to have a solid content of 0.1% by mass, and pH adjustment is not performed.

Dry deposit mass of the cationic organic compound is 0.3g ^{/ m 2} ~2.0g ^/ m 2 is preferred. When the dry adhesion amount of the cationic organic compound is lower than 0.3 g / m ² , sufficient image density improvement and feathering reduction effects may not be obtained.

  There is no restriction | limiting in particular as said surfactant, Although it can select suitably according to the objective, Any of an anionic active agent, a cationic active agent, an amphoteric active agent, and a nonionic active agent can be used. Of these, nonionic active agents are particularly preferred. By adding the surfactant, the water resistance of the image is improved, the image density is increased, and bleeding is improved.

Examples of the nonionic activator include higher alcohol ethylene oxide adduct, alkylphenol ethylene oxide adduct, fatty acid ethylene oxide adduct, polyhydric alcohol fatty acid ester ethylene oxide adduct, higher aliphatic amine ethylene oxide adduct, fatty acid amide. Ethylene oxide adduct, fat ethylene oxide adduct, polypropylene glycol ethylene oxide adduct, fatty acid ester of glycerol, fatty acid ester of pentaerythritol, fatty acid ester of sorbitol and sorbitan, fatty acid ester of sucrose, alkyl ether of polyhydric alcohol, And fatty acid amides of alkanolamines. These may be used individually by 1 type and may use 2 or more types together.
The polyhydric alcohol is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include glycerol, trimethylolpropane, pentaerythritol, sorbitol, and sucrose. As the ethylene oxide adduct, a product obtained by substituting a part of ethylene oxide with an alkylene oxide such as propylene oxide or butylene oxide is also effective as long as water solubility can be maintained. The substitution rate is preferably 50% or less. 4-15 are preferable and, as for HLB (hydrophilic / lipophilic ratio) of the said nonionic activator, 7-13 are more preferable.

  The addition amount of the surfactant is preferably 0 part by mass to 10 parts by mass, and more preferably 0.1 part by mass to 1.0 part by mass with respect to 100 parts by mass of the cationic organic compound.

  Other components can be added to the coating layer as needed, as long as the object and effect of the present invention are not impaired. Examples of the other components include additives such as alumina powder, pH adjuster, preservative, and antioxidant.

There is no restriction | limiting in particular as a formation method of the said coating layer, According to the objective, it can select suitably, It can carry out by the method of impregnating or apply | coating a coating layer liquid on the said support body. The impregnation or coating method of the coating layer liquid is not particularly limited and may be appropriately selected depending on the intended purpose. For example, conventional size press, gate roll size press, film transfer size press, blade coater, rod coater It is possible to coat with various coating machines such as air knife coater and curtain coater, but from the viewpoint of cost, conventional size press, gate roll size press, film transfer size press etc. installed in paper machine It may be impregnated or deposited and finished on-machine.
The adhesion amount of the coating layer liquid is not particularly limited and may be appropriately selected depending on the intended purpose, in ^{solid, 0.5g / m 2 ~20g / m} 2 are preferred, ^{1 g} / m 2 to 15 g / M ² is more preferable.
After the impregnation or application, drying may be performed as necessary. In this case, the drying temperature is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably about 100 to 250 ° C. .

The recording medium may further include a back layer on the back surface of the support, another layer between the support and the coating layer, or another layer between the support and the back layer, and a protective layer on the coating layer. Can also be provided. Each of these layers may be a single layer or a plurality of layers.
The recording medium is not particularly limited and may be appropriately selected according to the purpose. For example, in addition to the inkjet recording medium, commercially available coated paper for offset printing, coated paper for gravure printing, and the like may be used. .

(ink cartridge)
The ink cartridge of the present invention contains the ink in the ink media set of the present invention in a container, and further includes other members appropriately selected as necessary.

The container is not particularly limited, and its shape, structure, size, material and the like can be appropriately selected according to the purpose. For example, at least an ink bag formed of an aluminum laminate film, a resin film, or the like Preferred examples include those possessed.

Next, the ink cartridge will be described with reference to FIGS. Here, FIG. 5 is a view showing an example of the ink cartridge of the present invention, and FIG. 2 is a view including a case (exterior) of the ink cartridge of FIG.
As shown in FIG. 1, the ink cartridge is filled into the ink bag 241 from the ink inlet 242 and exhausted, and then the ink inlet 242 is closed by fusion. In use, the needle of the apparatus main body is pierced into the ink discharge port 243 made of a rubber member and supplied to the apparatus.
The ink bag 241 is formed of a packaging member such as a non-permeable aluminum laminate film. As shown in FIG. 2, the ink bag 241 is usually housed in a plastic cartridge case 244 and is detachably mounted on various ink jet recording apparatuses.

(Inkjet recording method and inkjet recording apparatus)
The inkjet recording method of the present invention uses the ink media set of the present invention,
It includes at least an ink flying step of applying a stimulus to the ink in the ink media set according to an image signal, causing the ink to fly and recording an image on a recording medium, and further including other steps appropriately selected as necessary. It becomes.

In the inkjet recording method, from the viewpoint of ejection reliability, dot position accuracy, and recording speed, the size of the droplets ejected from the nozzle is 2 to 40 pl, the speed is 6 to 20 m / s, the frequency is 1 kHz or more, and the resolution. Is preferably 300 dpi or more.
The droplet size is more preferably 3 to 30 pl, the velocity is more preferably 7 to 15 m / s, the frequency is more preferably 10 to 20 kHz, and the resolution is more preferably 600 to 1,200 dpi.

The amount of ink droplets ejected from the nozzle (M; pl) and the pixel diameter (D; μm) on the recording medium are expressed by the following equation: 18 × M ^0.43 ≦ D ≦ 35 × M To satisfy ^0.32 , in the gradation from halftone to solid, when the ejected droplets overlap on the media, the droplets merge and the color material density becomes uneven, resulting in image unevenness, This is preferable from the viewpoint of preventing the pixels from being unnecessarily entangled and causing bleeding and image noise.

  The ink jet recording apparatus of the present invention uses the ink media set of the present invention, applies a stimulus to the ink in the ink media set in accordance with an image signal, and causes the ink to fly to record an image on a recording medium. It has at least means, and further has other means appropriately selected as necessary.

The ink flying means is means for forming an image by applying a stimulus to the ink in the ink media set of the present invention and causing the ink to fly. The ink flying means is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include various recording heads (ink discharge heads), and particularly a head having a plurality of nozzle rows and a liquid storage. It is preferable to have a sub-tank that contains the liquid supplied from the tank for supplying the liquid to the head.
The sub tank includes negative pressure generating means for generating a negative pressure in the sub tank, atmospheric release means for releasing the inside of the sub tank to the atmosphere, and detection means for detecting the presence or absence of ink by a difference in electrical resistance. What has is preferable.

  The stimulus can be generated, for example, by the stimulus generating means, and the stimulus is not particularly limited and can be appropriately selected according to the purpose, such as heat (temperature), pressure, vibration, light, etc. Is mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, heat and pressure are preferable.

  Examples of the stimulus generating means include a heating device, a pressurizing device, a piezoelectric element, a vibration generating device, an ultrasonic oscillator, and a light. Specifically, a piezoelectric actuator such as a piezoelectric element, a thermal actuator that uses a phase change caused by film boiling of a liquid using an electrothermal transducer such as a heating resistor, a shape memory alloy actuator that uses a metal phase change caused by a temperature change, For example, an electrostatic actuator using an electrostatic force may be used.

There is no particular limitation on the mode of the ink flying, and it varies depending on the type of the stimulus. For example, when the stimulus is “heat”, the thermal energy corresponding to the recording signal is output to the ink in the recording head. For example, using a thermal head or the like, generating bubbles in the ink by the thermal energy, and discharging and ejecting the ink as droplets from the nozzle holes of the recording head by the pressure of the bubbles. It is done. Further, when the stimulus is “pressure”, for example, by applying a voltage to a piezoelectric element bonded to a position called a pressure chamber in an ink flow path in the recording head, the piezoelectric element bends and the volume of the pressure chamber is increased. And a method of ejecting and ejecting the ink as droplets from the nozzle holes of the recording head.
A method in which a voltage is applied to the piezo element to fly ink is preferable. Since the piezo method does not generate heat, it is advantageous for flying ink containing resin, and is an effective method with less nozzle clogging, particularly when ink containing a small amount of wetting agent is used.
In order to prevent nozzle omission, it is preferable to perform a blank scan by applying a voltage with a strength that does not eject ink to the piezo element. Furthermore, it is preferable to perform an operation of discharging ink to the ink reservoir before reaching the empty scan for one page printing.

  Further, it is preferable to have a scraping means for scraping off the ink fixed to the empty discharge receptacle. As the scraping means, either a wiper or a cutter is preferable.

  The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as sequencers and computers.

  Here, one aspect of carrying out the ink jet recording method of the present invention by the ink jet recording apparatus of the present invention will be described with reference to the drawings. FIG. 3 is a schematic view showing an example of the serial type ink jet recording apparatus of the present invention. The ink jet recording apparatus shown in FIG. 3 stocks an apparatus main body 101, a paper feed tray 102 for loading paper mounted on the apparatus main body 101, and paper on which an image is recorded (formed) mounted on the apparatus main body 101. A paper discharge tray 103 and an ink cartridge loading unit 104. On the upper surface of the ink cartridge loading unit 104, an operation unit 105 such as operation keys and a display is arranged. The ink cartridge loading unit 104 has a front cover 115 that can be opened and closed for attaching and detaching the ink cartridge 201.

In the apparatus main body 101, as shown in FIGS. 4 and 5, the carriage 133 is slid in the main scanning direction by guide rods 131 and stays 132 which are horizontally mounted on left and right side plates (not shown). The main scanning motor (not shown) moves and scans in the direction of the arrow in FIG.
The carriage 133 is provided with a recording head 134 composed of four ink jet recording heads that eject ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (Bk). Are arranged in a direction crossing the main scanning direction, and the ink droplet ejection direction is directed downward.
As the ink jet recording head constituting the recording head 134, a piezoelectric actuator such as a piezoelectric element, a thermal actuator using phase change due to liquid film boiling using an electrothermal transducer such as a heating resistor, a metal phase due to temperature change, and the like. A shape memory alloy actuator using a change, an electrostatic actuator using an electrostatic force, or the like provided as energy generating means for discharging ink can be used.

Also, the carriage 133 is equipped with a sub tank 135 for each color for supplying ink of each color to the recording head 134. The sub tank 135 is supplied with the ink from the ink cartridge 201 of the present invention loaded in the ink cartridge loading unit 105 via an ink supply tube (not shown) and is replenished.
On the other hand, as a paper feeding unit for feeding the paper 142 stacked on the paper stacking unit (pressure plate) 141 of the paper feed tray 102, a half-moon roller (feeding) that separates and feeds the paper 142 one by one from the paper stacking unit 141. A separation pad 144 made of a material having a large coefficient of friction is provided facing the paper roller 143) and the paper feed roller 143, and the separation pad 144 is urged toward the paper feed roller 143 side.
As a transport unit for transporting the paper 142 fed from the paper feed unit below the recording head 134, a transport belt 151 for transporting the paper 142 by electrostatic adsorption and a guide 145 from the paper feed unit. The counter roller 152 for transporting the paper 142 sent via the belt sandwiched between the transport belt 151 and the paper 142 fed substantially vertically upward are changed by approximately 90 ° to follow the transport belt 151. For this purpose, a conveyance guide 153 and a tip pressure roller 155 urged toward the conveyance belt 151 by a pressing member 154 are provided. In addition, a charging roller 156 that is a charging unit for charging the surface of the conveyance belt 151 is provided.
The conveyance belt 151 is an endless belt, is stretched between the conveyance roller 157 and the tension roller 158, and can circulate in the belt conveyance direction. The transport belt 151 includes, for example, a surface layer serving as a sheet adsorbing surface formed of a resin material having a thickness of about 40 μm that is not subjected to resistance control, for example, a copolymer of tetrafluoroethylene and ethylene (ETFE), and the surface layer. It has a back layer (medium resistance layer, ground layer) that is made of the same material and has resistance controlled by carbon. On the back side of the conveyance belt 151, a guide member 161 is arranged corresponding to the printing area by the recording head 134. As a paper discharge unit for discharging the paper 142 recorded by the recording head 134, a separation claw 171 for separating the paper 142 from the transport belt 151, a paper discharge roller 172, and a paper discharge roller 173 are provided. The paper discharge tray 103 is disposed below the paper discharge roller 172.

A double-sided paper feeding unit 181 is detachably mounted on the back surface of the apparatus main body 101. The double-sided paper feeding unit 181 takes in the paper 142 returned by the reverse rotation of the transport belt 151, reverses it, and feeds it again between the counter roller 152 and the transport belt 151. A manual paper feed unit 182 is provided on the upper surface of the duplex paper feed unit 181.
In this ink jet recording apparatus, the paper 142 is separated and fed one by one from the paper feed unit, and the paper 142 fed substantially vertically upward is guided by the guide 145 and between the transport belt 151 and the counter roller 152. It is sandwiched and conveyed. Further, the leading end is guided by the conveying guide 153 and pressed against the conveying belt 151 by the leading end pressure roller 155, and the conveying direction is changed by approximately 90 °.
At this time, the conveyance belt 157 is charged by the charging roller 156, and the sheet 142 is conveyed by being electrostatically attracted to the conveyance belt 151. Therefore, by driving the recording head 134 according to the image signal while moving the carriage 133, ink droplets are ejected onto the stopped paper 142 to record one line, and after the paper 142 is conveyed by a predetermined amount, Record the next line. Upon receiving a recording end signal or a signal that the trailing edge of the sheet 142 has reached the recording area, the recording operation is terminated and the sheet 142 is discharged onto the discharge tray 103.
When a near-end remaining amount of ink in the sub tank 135 is detected, a required amount of ink is supplied from the ink cartridge 201 to the sub tank 135.

  In this ink jet recording apparatus, when the ink in the ink cartridge 201 of the present invention is used up, the casing of the ink cartridge 201 can be disassembled and only the ink bag inside can be replaced. Further, the ink cartridge 201 can supply ink stably even when the ink cartridge 201 is placed vertically and has a front loading configuration. Therefore, even when the upper portion of the apparatus main body 101 is closed and installed, for example, when stored in a rack or when an object is placed on the upper surface of the apparatus main body 101, the ink cartridge 201 is used. Can be easily exchanged.

  In addition, although it demonstrated in the example applied to the serial type (shuttle type) inkjet recording device which a carriage scans, it can apply similarly to the line type inkjet recording device provided with the line type head.

  The ink jet recording apparatus and the ink jet recording method of the present invention can be applied to various types of recording by the ink jet recording method, and are particularly suitable for, for example, an ink jet recording printer, a facsimile apparatus, a copying apparatus, and a printer / fax / copier multifunction machine. Can be applied to.

(Ink record)
The ink recorded matter recorded by the ink jet recording method of the present invention is the ink recorded matter of the present invention. The ink recorded matter of the present invention has an image formed on the recording medium using the ink in the ink media set of the present invention.
The recording medium is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include plain paper, coated paper for printing, glossy paper, special paper, cloth, film, and OHP sheet. Can be mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, at least one of plain paper and coated paper for printing is preferable.
The plain paper is advantageous in that it is inexpensive. The coated paper for printing is advantageous in that it provides a smooth glossy image that is relatively inexpensive and glossy. However, although the drying property is poor and it is generally difficult to use for inkjet, the drying property is improved by the ink of the present invention.
The ink recorded matter has high image quality, no bleeding, excellent temporal stability, and can be suitably used for various purposes as a material on which various prints or images are recorded.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Preparation Example 1)
-Preparation of aqueous dispersion of magenta pigment-containing polymer fine particles-
<Preparation of polymer solution A>
After sufficiently replacing the inside of a 1 L flask equipped with a mechanical stirrer, thermometer, nitrogen gas introduction tube, reflux tube, and dropping funnel, 11.2 g of styrene, 2.8 g of acrylic acid, 12.0 g of lauryl methacrylate Then, 4.0 g of polyethylene glycol methacrylate, 4.0 g of styrene macromer, and 0.4 g of mercaptoethanol were mixed and heated to 65 ° C.
Next, 100.8 g of styrene, 25.2 g of acrylic acid, 108.0 g of lauryl methacrylate, 36.0 g of polyethylene glycol methacrylate, 60.0 g of hydroxylethyl methacrylate, 36.0 g of styrene macromer, 3.6 g of mercaptoethanol, azobismethylvalero A mixed solution of 2.4 g of nitrile and 18 g of methyl ethyl ketone was dropped into the flask over 2.5 hours. After the dropwise addition, a mixed solution of 0.8 g of azobismethylvaleronitrile and 18 g of methyl ethyl ketone was dropped into the flask over 0.5 hours. After aging at 65 ° C. for 1 hour, 0.8 g of azobismethylvaleronitrile was added and further aging was performed for 1 hour. After completion of the reaction, 364 g of methyl ethyl ketone was added to the flask to obtain 800 g of a polymer solution A having a concentration of 50% by mass.

<Preparation of pigment-containing polymer fine particle aqueous dispersion>
After sufficiently stirring 28 g of polymer solution A, 42 g of CI Pigment Red 122, 13.6 g of 1 mol / L potassium hydroxide aqueous solution, 20 g of methyl ethyl ketone, and 13.6 g of ion-exchanged water, using a roll mill Kneaded. The obtained paste was put into 200 g of pure water and stirred sufficiently, and then methyl ethyl ketone and water were distilled off by using an evaporator, and this dispersion was further removed with polyvinylidene fluoride having an average pore size of 5.0 μm to remove coarse particles. Pressure filtration was performed with a membrane filter to obtain an aqueous dispersion of magenta polymer fine particles containing 15% by mass of pigment and 20% by mass of solids. The average particle diameter of the obtained pigment dispersion _{(D 50)} was 127nm was measured. The average particle size (D ₅₀ ) was measured using a particle size distribution measuring device (Nikkiso Co., Ltd., Nanotrac UPA-EX150).

(Preparation Example 2)
-Preparation of cyan pigment-containing polymer fine particle dispersion-
A cyan polymer fine particle dispersion was prepared in the same manner as in Preparation Example 1, except that Pigment Pigment Red 122 was changed to a copper phthalocyanine pigment in Preparation Example 2.
The obtained polymer particles, a particle size distribution analyzer (Nikkiso Co., NANOTRAC UPA-EX150) average particle diameter _{(D 50)} measured in was 93 nm.

(Preparation Example 3)
-Preparation of yellow pigment-containing polymer fine particle dispersion-
A yellow polymer fine particle dispersion was prepared in the same manner as in Preparation Example 1 except that Pigment Pigment Red 122 was changed to Pigment Pigment Yellow 74 in Preparation Example 2.
The obtained polymer particles, a particle size distribution analyzer (Nikkiso Co., NANOTRAC UPA-EX150) average particle diameter _{(D 50)} measured in was 76 nm.

(Production Example 1)
-Production of cyan ink-
An ink composition having the following formulation was prepared and the pH was adjusted, followed by filtration with a membrane filter having an average pore diameter of 5 μm to produce an ink.
<Cyan ink composition>
-Cyan pigment-containing polymer fine particle dispersion of Preparation Example 2 16% by mass
Acrylic silicone emulsion [solid content 40% by mass, residual water, volume average particle size 150 nm, glass transition temperature of resin component -15 ° C. (differential rise) to −6 ° C. (inflection point)] 60% by mass
・ Glycerin as a wetting agent ... 20% by mass
・ Ethylene glycol monohexyl ether as glycol ether compound: 1% by mass
・ Fluorine-based surfactant (fluorine-substituted carbon number 4-16): 2.5% by mass
-Antiseptic and fungicide ... 0.05% by mass
・ Amine organic pH adjuster ... 1.1% by mass
・ Silicone emulsion antifoaming agent: 0.1% by mass
-Water ... balance The total content of the colorant and the water-dispersible resin in the obtained ink is 28% by mass, and the content of the water-dispersible resin relative to the total content of the colorant and the water-dispersible resin is It was 86 mass%.

(Production Example 2)
-Magenta ink production-
An ink composition having the following formulation was prepared and the pH was adjusted, followed by filtration with a membrane filter having an average pore diameter of 5 μm to produce an ink.
<Magenta ink composition>
-Magenta pigment-containing polymer fine particle dispersion of Preparation Example 1 16% by mass
Acrylic silicone emulsion [solid content 40% by mass, residual water, volume average particle size 150 nm, glass transition temperature of resin component -15 ° C. (differential rise) to −6 ° C. (inflection point)] 60% by mass
・ Glycerin as a wetting agent ... 20% by mass
・ Ethylene glycol monohexyl ether as glycol ether compound: 1% by mass
・ Fluorine-based surfactant (fluorine-substituted carbon number 4-16): 2.5% by mass
-Antiseptic and fungicide ... 0.05% by mass
・ Amine organic pH adjuster ... 1.1% by mass
・ Silicone emulsion antifoaming agent: 0.1% by mass
-Water ... balance The total content of the colorant and the water-dispersible resin in the obtained ink is 28% by mass, and the content of the water-dispersible resin relative to the total content of the colorant and the water-dispersible resin is It was 86 mass%.

(Production Example 3)
-Preparation of yellow ink-
An ink composition having the following formulation was prepared and the pH was adjusted, followed by filtration with a membrane filter having an average pore diameter of 5 μm to produce an ink.
<Yellow ink composition>
-Yellow pigment-containing polymer fine particle dispersion of Preparation Example 3 16% by mass
Acrylic silicone emulsion [solid content 40% by mass, residual water, volume average particle size 150 nm, glass transition temperature of resin component -15 ° C (differential rise) to -6 ° C (inflection point)] ... 30% by mass
・ Glycerin as a wetting agent ... 20% by mass
・ Ethylene glycol monohexyl ether as glycol ether compound: 1% by mass
・ Fluorine-based surfactant (fluorine-substituted carbon number 4-16): 2.5% by mass
-Antiseptic and fungicide ... 0.05% by mass
・ Amine organic pH adjuster ... 1.1% by mass
・ Silicone emulsion antifoaming agent: 0.1% by mass
-Water ... balance The total content of the colorant and the water-dispersible resin in the obtained ink is 14% by mass, and the content of the water-dispersible resin relative to the total content of the colorant and the water-dispersible resin is It was 86 mass%.

(Production Example 4)
-Preparation of black ink-
An ink composition having the following formulation was prepared and the pH was adjusted, followed by filtration with a membrane filter having an average pore diameter of 0.8 μm to produce an ink.
<Black ink composition>
-Carbon black dispersion having a hydrophilic group (solid content 20% by mass, the rest is water, colorant / resin (mass ratio) in the solid content = 10/0) ... 30% by mass
Acrylic silicone emulsion [solid content 40% by mass, residual water, volume average particle size 150 nm, glass transition temperature of resin component -15 ° C. (differential rise) to −6 ° C. (inflection point)] 45% by mass
・ Glycerin as a wetting agent ... 20% by mass
・ Ethylene glycol monohexyl ether as glycol ether compound: 1% by mass
・ Fluorine-based surfactant (fluorine-substituted carbon number 4-16): 1% by mass
-Antiseptic and fungicide ... 0.05% by mass
・ Stabilizer: 0.0005% by mass
・ Organic pH adjuster (2 types) ... 0.65 mass%
・ Silicone emulsion antifoaming agent: 0.1% by mass
-Water ... balance The total content of the colorant and the water-dispersible resin in the obtained ink is 24% by mass, and the content of the water-dispersible resin relative to the total content of the colorant and the water-dispersible resin is It was 75 mass%.

(Comparative Production Example 1)
-Production of cyan ink-
The cyan ink of Comparative Production Example 1 was prepared in the same manner as in Production Example 1 except that 1,3-butanediol was used instead of 2-ethyl-1,3-hexanediol as the glycol ether compound in Production Example 1. Was made.

(Comparative Production Example 2)
-Magenta ink production-
The cyan ink of Comparative Production Example 1 was prepared in the same manner as in Production Example 1 except that 1,3-butanediol was used instead of 2-ethyl-1,3-hexanediol as the glycol ether compound in Production Example 1. Was made.

(Comparative Production Example 3)
-Preparation of yellow ink-
The cyan ink of Comparative Production Example 1 was prepared in the same manner as in Production Example 1 except that 1,3-butanediol was used instead of 2-ethyl-1,3-hexanediol as the glycol ether compound in Production Example 1. Was made.

(Comparative Production Example 4)
-Preparation of black ink-
The cyan ink of Comparative Production Example 1 was prepared in the same manner as in Production Example 1 except that 1,3-butanediol was used instead of 2-ethyl-1,3-hexanediol as the glycol ether compound in Production Example 1. Was made.

  Next, the surface tension, pH, and viscosity of each of the inks of Production Examples 1 to 4 and Comparative Production Examples 1 to 4 were measured as follows. The results are shown in Table 1.

<Measurement of pH>
The pH was measured at 23 ° C. using a pH meter (MODEL HM3A, manufactured by Toa Denpa Kogyo Co., Ltd.).

<Measurement of viscosity>
The viscosity was measured at 25 ° C. using a RE500 viscometer (manufactured by Toki Sangyo Co., Ltd.) under conditions of cone 34 × R24, 180 rpm, 3 minutes later.

<Measurement of surface tension>
The surface tension is a static surface tension measured at 25 ° C. using a platinum plate using a surface tension measuring device (CBVP-Z, manufactured by Kyowa Interface Science Co., Ltd.).

<Recording media 1>
Commercial gloss paper (Oji Paper Co., Ltd., POD gloss coat 100 g / m ² paper)

  Next, the amount of pure water transferred, the critical surface tension (γc), and the smoothness of the recording medium 1 were measured as follows. The results are shown in Table 2.

<Measurement of the amount of pure water transferred by dynamic scanning absorption meter>
About each recording medium, the absorption curve of the pure water was measured using the dynamic scanning absorption meter (model: KS350D, Kyowa Seiko Co., Ltd. product). The absorption curve was plotted with a transition amount (mL / m ² ) and a square root of contact time √ (ms) to form a straight line having a certain slope, and the value of the transition amount after a certain time was measured by interpolation.

<Measurement of critical surface tension (γc)>
The critical surface tension (γc) is a wet tension test solution with various surface tensions (mixed solution of ethylene glycol monoethyl ether and formamide) in accordance with JIS-K6768-1999 “Plastic-film and sheet-wet tension test method”. 4 microliters (μL) of droplets were dropped on the media printing surface, and a contact angle measuring device (OCA, manufactured by Data Physics Co., Ltd.) was used to capture the contact angle of each droplet when moving 0.5 seconds. The Zisman Plot was created from the contact angle.

<Measurement of smoothness>
The smoothness is determined by J.H. TAPPI No. It was calculated | required based on 5B, for example, measured with the Oken type | mold smoothness meter (Asahi Seiko Co., Ltd. make, water column type).

(Example 1 and Comparative Example 1)
−Ink media set−
Ink set 1 comprising the cyan ink of Production Example 1, the magenta ink of Production Example 2, the yellow ink of Production Example 3, and the black ink of Production Example 4, the cyan ink of Comparative Production Example 1, and the magenta ink of Comparative Production Example 2 An ink media set was prepared by combining the ink set 2 composed of the yellow ink of Comparative Production Example 3 and the black ink of Comparative Production Example 4 and the recording medium 1 as shown in Table 3 below.
Using the obtained ink media set, the drying time was measured as follows. The results are shown in Table 3.

<Measurement of drying time>
The drying time is 23.degree. C., 50% RH environment. From the time when 1 .mu.l of ink is dropped on the recording surface of the recording medium, the ink is evaporated on the recording medium surface by evaporation or solvent penetration into the recording medium. The time until the solvent no longer exists as droplets was measured.
The fact that the ink solvent no longer exists as droplets on the surface of the recording medium was confirmed by, for example, pressing the filter paper against the surface of the recording medium on which the ink was dropped to stop transfer.

<Evaluation of image density>
Next, using each ink media set, a solid image was created with an inkjet printer (manufactured by Ricoh Co., Ltd., G707), and image density was evaluated using X-Rite 938 (manufactured by X-Rite). The image density of Example 1 was better than that of Comparative Example 1.

The ink media set of the present invention has a problem of drying speed on a smooth printing paper having a low water absorption capability, and can produce a clear and high-quality image close to a printed material. It can be suitably used for a method and an ink jet recording apparatus.
The ink jet recording apparatus and the ink jet recording method of the present invention can be applied to various types of recording by the ink jet recording method, and are particularly suitable for, for example, an ink jet recording printer, a facsimile apparatus, a copying apparatus, and a printer / fax / copier multifunction machine. Can be applied to.

FIG. 1 is a schematic view showing an example of the ink cartridge of the present invention. FIG. 2 is a schematic view including a case (exterior) of the ink cartridge of FIG. FIG. 3 is an explanatory perspective view of the ink jet recording apparatus in a state where the cover of the ink cartridge loading unit is opened. FIG. 4 is a schematic configuration diagram illustrating the overall configuration of the ink jet recording apparatus. FIG. 5 is a schematic enlarged view showing an example of an inkjet head in the inkjet recording apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Frame 20 Flow path plate 30 Nozzle plate 40 Base 50 Laminated piezoelectric element 60 Vibrating plate 70 Adhesive layer 101 Device main body 102 Paper feed tray 103 Paper discharge tray 104 Ink cartridge loading part 111 Upper cover 112 Front surface 115 Front cover 131 Guide rod 132 Stay 133 Carriage 134 Recording Head 135 Subtank 141 Paper Placement Unit 142 Paper 144 Separation Pad 151 Conveying Belt 152 Again Counter Roller 156 Charging Roller 157 Conveyance Roller 158 Densation Roller 171 Separation Claw 172 Paper Discharge Roller 173 Paper Discharge Roller 181 Double-sided Paper Feed Unit 201 Ink cartridge 241 Ink bag 242 Ink inlet 243 Ink outlet 244 Cartridge exterior

Claims (19)

An ink containing at least a colorant, a water-dispersible resin, a water-soluble organic solvent, a surfactant, and water;
A support and a recording medium having a coating layer containing at least a pigment and a binder on the support;
The water-soluble organic solvent contains 0.1 to 10% by mass of at least one selected from glycol ether compounds represented by the following general formula (I):
An ink media set, wherein a drying time in a 23 ° C., 50% RH environment when 1 μl of the ink is dropped on the recording surface of the recording medium is 18 minutes or less.
<General formula (I)>
_{^{R 1 - (OR 2) m}} -OH
In the general formula (I), R ¹ represents an alkyl group having 1 to 8 carbon atoms which may be branched, represent any of the allyl group and an aryl group. R ² represents either an ethyl group or an isopropyl group. m represents an integer of 1 to 4.   The ink media set according to claim 1, wherein a critical surface tension based on JIS K6768 on the recording surface of the recording medium is 25 mN / m to 40 mN / m. A dynamic scanning liquid absorption meter transfer amount is ^2ml / ^{m 2 ~35ml} / m 2 of the recording surface of the recording medium of pure water at the contacting time 100ms measured by, and the recording medium of pure water at the contacting time 400ms the ink media set according to any one of claims 1 to 2 transfer amount of the recording surface is ^3ml / ^{m 2 ~40ml} / m 2 of.   In the recording surface of the recording medium, J. TAPPI No. The ink media set according to any one of claims 1 to 3, wherein the smoothness based on 5B is 200 seconds to 20,000 seconds.   The ink media set according to any one of claims 1 to 4, wherein the pigment in the coating layer contains any one of kaolin, talc, and calcium carbonate.   The surfactant in the ink is at least one selected from silicone surfactants and fluorosurfactants, and the content of the surfactant is 0.01% by mass to 5% by mass. To 5. The ink media set according to any one of 5 to 5.   The ink media set according to any one of claims 1 to 6, wherein the water-soluble organic solvent in the ink contains at least one selected from glycerin, 1,3-butanediol, 2-pyrrolidone, and dipropylene glycol.   The water-dispersible resin in the ink contains resin fine particles, the resin fine particles are acrylic silicone resin fine particles, and the glass transition temperature of the acrylic silicone resin is 25 ° C. or lower. Ink media set.   The ink media set according to claim 8, wherein the volume average particle diameter of the resin fine particles in the resin emulsion is 10 nm to 1,000 nm.   The colorant in the ink contains a pigment having at least one hydrophilic group on the surface and exhibiting at least one of water dispersibility and water solubility in the absence of a dispersant. Ink media set.   The total content of the colorant and the water-dispersible resin in the ink is 10% by mass to 35% by mass, and the content of the water-dispersible resin is 70% by mass to the total content of the colorant and the water-dispersible resin. The ink media set according to any one of claims 1 to 10, which is 95% by mass.   An ink cartridge comprising the ink in the ink media set according to claim 1 contained in a container. An inkjet recording method using the ink media set according to any one of claims 1 to 11,
An ink jet recording method comprising at least an ink flying step of applying a stimulus to ink in the ink media set according to an image signal and causing the ink to fly to record an image on a recording medium.   The inkjet recording method according to claim 13, wherein the stimulus is at least one selected from heat, pressure, vibration, and light.   The ink is ejected from a nozzle, and a droplet ejected from the nozzle has a size of 2 to 40 pl, a velocity of 6 to 20 m / s, a frequency of 1 kHz or more, and a resolution of 300 dpi or more. The inkjet recording method according to any one of the above. The amount of ink droplets ejected from the nozzle (M; pl) and the pixel diameter (D; μm) on the recording medium are expressed by the following equation: 18 × M ^0.43 ≦ D ≦ 35 × M ^0. the ink jet recording method according to claim 15 satisfying ^32. An ink jet recording apparatus using the ink media set according to claim 1,
An ink jet recording apparatus comprising at least ink flying means for applying a stimulus to an ink in the ink media set according to an image signal and flying the ink to record an image on a recording medium.   The inkjet recording apparatus according to claim 17, wherein the stimulus is at least one selected from heat, pressure, vibration, and light.   An ink recorded matter comprising the ink media set according to any one of claims 1 to 11 and having an image formed using ink on a recording medium.