JP6149909B2 - Inkjet recording method and recording set - Google Patents

Description

  The present invention relates to an ink jet recording method, an ink jet recording apparatus, and a recording set.

A recording ink containing an aqueous pigment has advantages such as less bleeding, high image density, and less show-through when printing on plain paper. However, when printing on plain paper has a large amount of ink adhering to photographs, figures, etc., plain paper tends to back curl immediately after printing. Here, the back curl is a phenomenon in which the paper is warped on the side opposite to the printing surface.
If the plain paper is back curled immediately after printing, a paper conveyance failure occurs in the paper conveyance process in the ink jet printer. In particular, if the paper is back-curled during high-speed printing or double-sided printing, paper conveyance is very difficult.
Accordingly, it is desired to provide a recording ink with as little back curl as possible even when the amount of ink adhering to a photograph or drawing is large in printing on plain paper. In particular, the need for a high-speed inkjet printer with a line head is higher than that of a serial printer.

As a prior art document that suppresses curling of paper, a method is proposed in which alcohol liquid is applied to paper prior to recording with ink, the paper is substantially dried at the recording position, and then recording is performed with ink. (See Patent Document 1). In this proposal, it is described that a hydroxyl group of an alcohol liquid is bonded to a hydroxyl group existing at a bonding point by hydrogen bonding between cellulose fibers of paper, and water molecules in the ink are blocked by a hydrophobic group portion of the alcohol liquid. When a large amount of water-based ink is driven in printing, there is no effect and curling suppression immediately after printing cannot be achieved.
Also, a recording method for ejecting ink and a reaction liquid that reacts with ink, and a method for ejecting the reaction liquid onto a recording medium on the opposite side on which the same data as the data for recording ink is recorded has been proposed. (See Patent Document 2). However, it is economically disadvantageous because the configuration of the ink jet recording apparatus is complicated and curling cannot be suppressed unless a reaction liquid prepared with a composition almost equivalent to ink is ejected in the same amount. Furthermore, when the printing is close to solid printing, both sides of the paper contain a large amount of moisture, so that the paper becomes stiff and paper conveyance becomes difficult.

  Further, a recording ink composition containing diglycerin or polyglycerin and polyethylene glycol monoalkyl ether has been proposed (see Patent Document 3). Further, a recording ink composition containing polyethylene glycol monomethyl ether has been proposed (see Patent Document 4). However, even these proposals are not effective when a large amount of water-based ink is applied in high-speed printing, and curl suppression immediately after printing cannot be satisfied. In addition, there is a problem in that the ejection stability cannot be secured because the equilibrium water content of the solvent is small.

  Accordingly, it is possible to reduce the curl amount of plain paper immediately after printing, excellent recording quality for plain paper and high-speed printing, good ejection stability, and excellent drying characteristics on general-purpose printing paper and its ink At present, prompt provision of related technologies is desired.

  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 can reduce the curl amount of plain paper immediately after printing, is excellent in image quality and high-speed printing on plain paper, has good ejection stability, and has excellent drying characteristics on general-purpose printing paper. The purpose is to provide ink for use.

Means for solving the problems are as follows. That is,
The recording ink of the present invention is a recording ink containing at least water, a water-soluble organic solvent, a surfactant, and a colorant,
As the water-soluble organic solvent, one or more polyhydric alcohols having an equilibrium water content of 30% by mass or more at a temperature of 23 ° C. and a humidity of 80% RH, and at least one of amide compounds represented by the following general formula (I) It contains a seed.
However, in said general formula (I), R < ₁ > and R < ₂ > all show a methyl group, R < ₃ > shows a C4-C6 alkyl group.
The recording ink of the present invention is a recording ink containing at least water, a water-soluble organic solvent, a surfactant, and a colorant,
The water-soluble organic solvent contains at least one amide compound represented by the following general formula (I) and an amide compound represented by the following structural formula (i).
However, in said general formula (I), R < ₁ > and R < ₂ > all show a methyl group, R < ₃ > shows a C4-C6 alkyl group.

In a first embodiment, the recording ink of the present invention is a recording ink containing at least water, a water-soluble organic solvent, a surfactant, and a colorant,
As the water-soluble organic solvent, at least one of polyhydric alcohols having an equilibrium water content of 30% by mass or more at a temperature of 23 ° C. and a humidity of 80% RH, and at least one of the amide compounds represented by the above general formula (I) Contains seeds.
In a second embodiment, the recording ink of the present invention is a recording ink containing at least water, a water-soluble organic solvent, a surfactant, and a colorant,
The water-soluble organic solvent contains at least one amide compound represented by the general formula (I) and an amide compound represented by the structural formula (i).
In the recording inks according to the first and second embodiments of the present invention, by providing all the above-described configurations, it is possible to reduce the curl amount of plain paper immediately after printing, and it is excellent in image quality and high-speed printing for plain paper. In addition, the discharge stability is good, and image recording with excellent drying property on general-purpose printing paper is possible.

Furthermore, a general-purpose printing paper (which has a support and a coating layer coated on at least one surface of the support, and recorded pure water at a contact time of 100 ms measured by a dynamic scanning absorption meter. transfer amount to use media is ^{1mL / m 2 ~10mL / m 2} , and the contact time transfer amount of the recording medium of pure water at the 400ms ink absorbing such that ^3mL / ^{m 2 ~25mL} / m 2 High-quality image formation is possible when a recording medium having low properties is used.

  According to the present invention, conventional problems can be solved, curl amount of plain paper immediately after printing can be reduced, image quality on plain paper and high-speed printing are excellent, and discharge stability is good. It is possible to provide a recording ink having excellent drying properties on a printing paper.

FIG. 1 is a schematic view showing an ink cartridge of the present invention. FIG. 2 is a schematic view showing a modification of the ink cartridge of FIG. FIG. 3 is a perspective view of the ink jet recording apparatus in a state where the cover of the ink cartridge loading unit is opened. 4 is a cross-sectional view illustrating the overall configuration of the ink jet recording apparatus of FIG. FIG. 5 is a schematic enlarged view showing an ink jet head in the ink jet recording apparatus of the present invention. FIG. 6 is a diagram for explaining the difference in action of water-insoluble organic substances having water and hydroxyl groups between cellulose molecules, (a) schematic diagram of elementary fibrils, (b) schematic diagram of cellulose molecules, (c) FIG. 4 is a diagram showing hydrogen bonds (α), (β), and (γ) generated between two cellulose molecules. FIG. 7 is a diagram showing a prototype line head printer used for evaluation of curl amount in the reference example.

(Ink for recording)
The recording ink of the present invention contains at least water, a water-soluble organic solvent, a surfactant, and a colorant, and contains a penetrating agent, a water-dispersible resin, and, if necessary, other components.

<Water-soluble organic solvent>
As the first form of the water-soluble organic solvent, one or more polyhydric alcohols having an equilibrium water content of 30% by mass or more at a temperature of 23 ° C. and a humidity of 80% RH are represented by the following general formula (I): Containing at least one amide compound.
However, in said general formula (I), R < ₁ > and R < ₂ > all show a methyl group, R < ₃ > shows a C4-C6 alkyl group.
As a second form of the water-soluble organic solvent, it contains at least one amide compound represented by the above general formula (I) and an amide compound represented by the following structural formula (i).

  The water-soluble organic solvent contains at least one amide compound represented by the general formula (I). Thereby, curling immediately after printing is suppressed, and a high-quality recording ink can be obtained. This is because the water-soluble organic solvent hardly breaks hydrogen bonds between cellulose molecules even if it penetrates between cellulose molecules.

This will be described in more detail. The amide compound represented by the general formula (I) has a hydrophilic group and a lipophilic group that are more lipophilic than the conventional water-soluble organic solvents (glycerin, butanediol, etc.). Since it is rich and has a small proportion of hydroxyl groups that are hydrophilic groups capable of hydrogen bonding in the molecule, it is presumed that even if it penetrates between cellulose molecules, it is difficult to break hydrogen bonds between cellulose molecules. In short, this model is “low aggressiveness against hydrogen bonds between cellulose molecules”.
Further, since the water-soluble organic solvent rich in lipophilic groups has a low surface tension, it penetrates between cellulose molecules and is represented by the general formula (I) as shown in FIG. In the amide compound, the amide group hydrogen bonds to the hydroxyl group of the cellulose molecule, stays in the cellulose molecule part, the lipophilic group of the alkyl group part covers the hydrogen bond of the cellulose molecule, and is a volatile hydrophilic group-rich solvent. It is estimated that it is difficult to break the hydrogen bond between cellulose molecules. In short, this model is called “coverage of hydrogen bonds of cellulose molecules”.
In addition, the amide compound represented by the general formula (I) that covers the hydrogen bonds of cellulose molecules and inhibits contact with an aqueous continuous phase (alcohol, water, etc.) is an auxiliary effect. Is a water-soluble organic solvent called alkylalkanediol and glycol ether compound, so that even if water is volatilized, precipitation of solids, solidification, and decrease in fluidity are unlikely to occur. It is estimated that the discharge stability is maintained.

Here, with reference to FIG. 6, the difference in the action of water-soluble organic solvents having water and hydroxyl groups between cellulose molecules will be described.
FIG. 6A is a schematic diagram of an elementary fibril. Plant fibers have a filamentous structure called fibrils, fibrils are further composed of microfibrils having a diameter of several nm to 20 nm and lengths of 1 μm to several μm, and microfibrils are further composed of several to several tens of elementary fibrils.
FIG. 6B is a schematic diagram of cellulose molecules. Elementary fibrils consist of dozens of cellulose molecules arranged in parallel. At this time, a strong hydrogen bond is formed between adjacent cellulose molecules, and a bundle having a diameter of about 3 nm to 4 nm is formed.
FIG. 6C is a model diagram showing aspects (α), (β), and (γ) of hydrogen bonds generated between two cellulose molecules. The dotted line represents a hydrogen bond, and R represents a lipophilic group. The hydrogen bond (α) indicates a normal hydrogen bond state between cellulose molecules. The hydrogen bond (β) indicates a state in which water molecules are interposed in hydrogen bonds between cellulose molecules, and the position of hydrogen bonds is changed by evaporation of the water. To further explain this phenomenon, when water infiltrates into paper and the bond between cellulose is cut, the fibers loosen and extend (back curl phenomenon).
Here, when water disappears from the site by drying and movement, the fibers shrink and the broken hydrogen bonds recombine. However, there is no natural pressure applied to the paper as it is being made, and during this drying process the fibers are hydrogen bonded in a free and loose position, resulting in a different paper shape, ie, a face curl. This refers to the phenomenon of paper warping on the ink printing surface side). The hydrogen bond (γ) is a hydroxyl group that does not participate in the hydrogen bond of cellulose, and the hydrophilic group (amide group) of the amide compound represented by the general formula (I) is interposed, and further water molecules between the cellulose molecules. The state which prevents the entrance of is shown.
As the amide compound represented by the general formula (I), an appropriately synthesized compound or a commercially available product may be used.

  Furthermore, as the alkylalkanediol as a water-soluble organic solvent that shows an auxiliary effect, as long as the main chain is an alkanediol having 3 to 5 carbon atoms and the branched chain is an alkyl having 1 to 2 carbon atoms, The balance between hydrophilic groups and lipophilic groups becomes water-soluble and rich in lipophilic groups, and the above-mentioned models of “low aggressiveness against hydrogen bonding between cellulose molecules” and “coverage of hydrogen bonding between cellulose molecules” are better expressed. . Among these, 2-methyl-1,3-propanediol, 3-methyl-1,3-butanediol, and 3-methyl-1,5-pentanediol are particularly preferable.

The subject of the present invention can be solved by using at least an amide compound represented by the above general formula (I) as the water-soluble organic solvent and mixing and using the water-soluble organic solvent described below.
As described above, in the amide compound represented by the general formula (I), the balance between the hydrophilic group and the lipophilic group is rich in the lipophilic group, and the ratio of the hydroxyl group that is a hydrophilic group capable of hydrogen bonding in the molecule is small. Therefore, even if it penetrates between cellulose molecules, it is estimated that hydrogen bonds between cellulose molecules are difficult to break. Among these, amide compounds represented by the following structural formula (ii) and the following structural formula (iii) The amide compound represented is particularly preferred.

  The content of the amide compound represented by the general formula (I) in the recording ink is preferably 1% by mass to 50% by mass, and more preferably 2% by mass to 40% by mass. When the content is less than 1% by mass, there is no curl suppression effect and no image quality improvement effect is observed, and furthermore, there is a case where the drying property improvement effect for general-purpose printing paper may be lost, and when the content exceeds 50% by mass, Ink viscosity may improve and ejection stability may become severe.

Examples of the organic solvent used by mixing with the amide compound represented by the general formula (I) include amide compounds represented by the following structural formula (i).
The amide compound represented by the structural formula (i) has a boiling point as high as 216 ° C., a temperature of 23 ° C., a relative humidity of 80%, an equilibrium water content as high as 39.2% by mass, and a liquid viscosity of 25 ° C. It is very low at 1.48 mPa · s in the environment. Furthermore, since it is very easy to dissolve in the amide compound represented by the general formula (I), the water-soluble organic solvent and water, the viscosity of the recording ink can be reduced, and the water-soluble organic solvent used for the recording ink is Is highly preferred. Since the recording ink containing the amide compound represented by the structural formula (i) has a high equilibrium water content and can reduce the viscosity of the ink, the storage stability and ejection stability are good, and The ink is also gentle to the maintenance device of the ink ejection device.
The content of the amide compound represented by the structural formula (i) in the recording ink is preferably 1% by mass to 50% by mass, and more preferably 2% by mass to 40% by mass. When the content is less than 1% by mass, there is no effect in reducing the viscosity of the ink and the ejection stability may be lowered. When the content exceeds 50% by mass, the drying property on the paper surface is inferior and further on plain paper. Character quality may be reduced.

Furthermore, as a water-soluble organic solvent that shows the curl-suppressing effect as a supplement, there is an alkylalkanediol, which has an alkanediol having 3 to 5 carbon atoms as a main chain and an alkyl having 1 to 2 carbon atoms as a branched chain. If present, the balance between the hydrophilic group and the lipophilic group becomes water-soluble and rich in the lipophilic group, and the above-mentioned models of “low attack against hydrogen bonds between cellulose molecules” and “coverability of hydrogen bonds of cellulose molecules” are more effective. It expresses well.
Among these, 2-methyl-1,3-propanediol (bp 214 ° C.), 3-methyl-1,3-butanediol (bp 203 ° C.), and 3-methyl-1,5-pentanediol (bp 250 ° C.) are preferable. .
The content of the alkylalkanediol in the recording ink is preferably 2% by mass to 40% by mass, and more preferably 5% by mass to 30% by mass. When the content is less than 2% by mass, there is no curl suppression effect and no image quality improvement effect is observed, and furthermore, there is a case where the drying property improvement effect for general-purpose printing paper may be lost, and when the content exceeds 40% by mass, Ink viscosity may improve and ejection stability may become severe.

  In addition, as a water-soluble organic solvent used by mixing with the amide compound represented by the general formula (I), the amide compound represented by the structural formula (i), and the alkylalkanediol, a temperature of 23 ° C. , Including at least one polyhydric alcohol having an equilibrium water content of 30% by mass or more in an environment having a relative humidity of 80%. For example, as described above, the wetting agent A (wetting agent A has a fairly high equilibrium water content and boiling point) Equilibrium moisture content in an environment of temperature 23 ° C. and relative humidity 80% is 30% by mass or more and boiling point is 250 ° C. or more. The equilibrium moisture content of the wetting agent A is preferably 40% by mass or more), and Contains a wetting agent B having a high equilibrium moisture content but a relatively low boiling point (wetting agent B has an equilibrium moisture content of 30% by mass or more at 23 ° C. and 80% and a boiling point of 140 ° C. to 250 ° C.). Is preferred.

Examples of the wetting agent A having a boiling point exceeding 250 ° C. at normal pressure in the polyhydric alcohol include 1,2,3-butanetriol (bp175 ° C./33 hPa, 38 mass%), 1,2,4-butanetriol (bp190 -191 ° C / 24 hPa, 41 mass%), glycerin (bp290 ° C, 49 mass%), diglycerin (bp270 ° C / 20 hPa, 38 mass%), triethylene glycol (bp285 ° C, 39 mass%), tetraethylene glycol ( bp 324-330 ° C., 37% by mass) and the like, and the wetting agent B having a boiling point of 140 ° C. to 250 ° C. is diethylene glycol (bp 245 ° C., 43% by mass), 1,3-butanediol (bp 203-204 ° C., 35% by mass). %).
These wetting agent A and wetting agent B are both highly hygroscopic materials having an equilibrium moisture content of 30% by mass or more in an environment at a temperature of 23 ° C. and a relative humidity of 80%. It is also true that evaporability is relatively higher than A. Among these, glycerin and 1,3-butanediol are particularly preferable.
When the combination of the humectant A and the humectant B is used, the content ratio B / A (mass ratio) of the humectant A and the humectant B is determined by the amount of the other humectant C, the penetrant, etc. Since it depends on the type and amount of other additives, it cannot be said unconditionally. For example, a range of 10/90 to 90/10 is preferable.

In the present invention, the equilibrium water content is determined by using a saturated aqueous solution of potassium chloride / sodium chloride, keeping the temperature and humidity in the desiccator at a temperature of 23 ± 1 ° C. and a relative humidity of 80 ± 3% RH. The petri dish weighed 1 g at a time was stored and the amount of water to be equilibrated was determined.
Equilibrium water content (%) = (water content absorbed in organic solvent / organic solvent + water content absorbed in organic solvent) × 100
When the polyhydric alcohol is used in an amount of 50% by mass or more based on the total amount of the water-soluble organic solvent, it is excellent in securing ejection stability and preventing waste ink sticking in a maintenance device of the ink ejection device.
In the recording ink of the present invention, in addition to the wetting agents A and B, if necessary, instead of a part of the wetting agents A and B, or in addition to the wetting agents A and B, the other wetting agents. C (the other wetting agent C, for example, typically has an equilibrium water content of less than 30% by mass at 23 ° C. and 80% RH) can be used in combination.
Examples of the wetting agent C include polyhydric alcohols, polyhydric alcohol alkyl ethers, polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, sulfur-containing compounds, propylene carbonate, and ethylene carbonate. , Other wetting agents, and the like.

Examples of the polyhydric alcohols include dipropylene glycol (bp 232 ° C.), 1,5-pentanediol (bp 242 ° C.), propylene glycol (bp 187 ° C.), 2-methyl-2,4-pentane diol (bp 197 ° C.). , Ethylene glycol (bp196-198 ° C.), tripropylene glycol (bp 267 ° C.), hexylene glycol (bp 197 ° C.), polyethylene glycol (viscous liquid to solid), polypropylene glycol (bp 187 ° C.), 1,6-hexanediol ( bp253-260 ° C), 1,2,6-hexanetriol (bp178 ° C), trimethylolethane (solid, mp 199-201 ° C), trimethylolpropane (solid, mp61 ° C) and the like.
Examples of the polyhydric alcohol alkyl ethers include ethylene glycol monoethyl ether (bp 135 ° C.), ethylene glycol monobutyl ether (bp 171 ° C.), diethylene glycol monomethyl ether (bp 194 ° C.), diethylene glycol monoethyl ether (bp 197 ° C.), and diethylene glycol monoethyl ether. Examples include butyl ether (bp 231 ° C.), ethylene glycol mono-2-ethylhexyl ether (bp 229 ° C.), propylene glycol monoethyl ether (bp 132 ° C.), and the like.
Examples of the polyhydric alcohol aryl ethers include ethylene glycol monophenyl ether (bp 237 ° C.) and ethylene glycol monobenzyl ether.
Examples of the nitrogen-containing heterocyclic compound include 2-pyrrolidone (bp 250 ° C., mp 25.5 ° C., 47 to 48% by mass), N-methyl-2-pyrrolidone (bp 202 ° C.), 1,3-dimethyl-2- Examples include imidazolidinone (bp 226 ° C.), ε-caprolactam (bp 270 ° C.), γ-butyrolactone (bp 204-205 ° C.), and the like.
Examples of the amides include formamide (bp 210 ° C.), N-methylformamide (bp 199-201 ° C.), N, N-dimethylformamide (bp 153 ° C.), N, N-diethylformamide (bp 176-177 ° C.), and the like. Can be mentioned.
Examples of the amines include monoethanolamine (bp 170 ° C), diethanolamine (bp268 ° C), triethanolamine (bp360 ° C), N, N-dimethylmonoethanolamine (bp139 ° C), N-methyldiethanolamine (bp243 ° C). ), N-methylethanolamine (bp159 ° C.), N-phenylethanolamine (bp282-287 ° C), 3-aminopropyldiethylamine (bp169 ° C), and the like.
Examples of the sulfur-containing compounds include dimethyl sulfoxide (bp 139 ° C.), sulfolane (bp 285 ° C.), thiodiglycol (bp 282 ° C.), and the like.

Other solid wetting agents are preferably sugars.
Examples of the saccharide include monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides), polysaccharides, and the like.
Specific examples include glucose, mannose, fructose, ribose, xylose, arabinose, galactose, maltose, cellobiose, lactose, sucrose, trehalose, maltotriose, and the like.
Here, the polysaccharide means a saccharide in a broad sense, and is used to include a substance that exists widely in nature such as α-cyclodextrin and cellulose.
The derivatives of these saccharides are represented by the reducing sugars of the saccharides described above (for example, sugar alcohol (general formula: HOCH ₂ (CHOH) _n CH ₂ OH (where n represents an integer of 2 to 5)). ), Oxidized sugars (for example, aldonic acid, uronic acid, etc.), amino acids, thioic acids, etc. Among these, sugar alcohols are preferable, and specific examples include maltitol, sorbit, and the like.

The mass ratio of the pigment and the wetting agent has a great influence on the stability of ink ejection from the head, and also has an effect on preventing the sticking of waste ink in the maintenance device of the ink ejection apparatus.
If the blending amount of the wetting agent is small even though the pigment solid content is high, water evaporation near the ink meniscus of the nozzle may progress and cause ejection failure.
A water-soluble organic solvent containing the amide compound represented by the general formula (I), the amide compound represented by the structural formula (i), the alkylalkanediol compound, and the wetting agents A, B, and C, The content in the recording ink is preferably 20% by mass to 80% by mass, and more preferably 30% by mass to 70% by mass. When the content is less than 20% by mass, the curl suppressing effect is not observed, and the discharge stability is lowered and the waste ink is firmly fixed by the maintenance device. On the other hand, if it exceeds 80% by mass, the viscosity of the recording ink becomes very high and it may be difficult to eject the ink with an ink ejection device. In addition, the drying property on paper is inferior, and the character quality on plain paper may be lowered.

<Water>
As said water, pure water, such as ion-exchange water, ultrafiltration water, reverse osmosis water, distilled water, or ultrapure water can be used, for example.
The content of the water in the recording ink is not particularly limited and can be appropriately selected depending on the purpose.

<Colorant>
The following first to third forms are particularly preferred when the colorant is a pigment.
(1) In the first embodiment, the colorant has a pigment dispersion (hereinafter referred to as “self-dispersing pigment”) having at least one hydrophilic group on the surface and exhibiting water dispersibility in the absence of a dispersant. May also be referred to).

(2) In the second embodiment, the colorant is a pigment dispersion containing a pigment, a pigment dispersant and a polymer dispersion stabilizer, and the polymer dispersion stabilizer is represented by the following general formula (A): It is at least one selected from the α-olefin-maleic anhydride copolymer, styrene- (meth) acrylic copolymer, water-soluble polyurethane resin and water-soluble polyester resin.

However, in said general formula (A), R represents a C6-C30, Preferably 12-22, More preferably, it represents an 18-22 alkyl group. n represents an integer of 1 or more, and an integer of 20 to 100 is preferable.

  The α-olefin-maleic anhydride copolymer represented by the general formula (A) can also be synthesized using a mixture of olefins containing olefins having different carbon numbers as raw materials. In that case, the R part is a copolymer in which alkyl groups having different carbon numbers are randomly introduced into the polymer chain. In the present invention, not only an α-olefin-maleic anhydride copolymer in which an alkyl group having a uniform R carbon number is introduced into a polymer chain, but also an alkyl having a different R carbon number as described above. An α-olefin-maleic anhydride copolymer in which groups are randomly introduced into the polymer chain can also be used as the α-olefin-maleic anhydride copolymer represented by the general formula (A). is there.

The α-olefin-maleic anhydride copolymer represented by the general formula (A) preferably has a weight average molecular weight of 5,000 to 20,000.
Here, the weight average molecular weight of the α-olefin-maleic anhydride copolymer can be measured as follows.
<Measurement of weight average molecular weight>
The average molecular weight of the copolymer can be measured using a GPC (gel permeation chromatograph) analysis system.
First, a copolymer is dissolved in the same tetrahydrofuran as the eluent, and KF806L (for THF) is used as a GPC column. In addition, three types of polystyrene having different molecular weights (molecular weights 1,000, 2,400, 8,500) whose molecular weights are known are measured as molecular weight standard substances, and a calibration curve is created.
Next, the copolymer is subjected to GPC measurement, and the weight average molecular weight is calculated from the resulting SEC chromatogram, the differential molecular weight distribution curve and the graph reflecting the calibration curve obtained from the molecular weight standard substance.

(3) In the third embodiment, the colorant contains an aqueous dispersion of water-insoluble polymer particles containing a pigment (an aqueous dispersion of polymer fine particles containing a coloring material).

  As the pigment, an organic pigment or an inorganic pigment can be used. In addition, although you may contain dye simultaneously for the purpose of color tone adjustment, it is possible to use within the range which does not degrade a weather resistance.

  Examples of the inorganic pigment include titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, chrome yellow, and carbon black. Among these, carbon black is particularly preferable. In addition, as said carbon black, what was manufactured by well-known methods, such as a contact method, a furnace method, and a thermal method, is mentioned, for example.

  Examples of the organic pigment include azo pigments, polycyclic pigments, dye chelates, nitro pigments, nitroso pigments, and aniline black. Among these, azo pigments and polycyclic pigments are more preferable. Examples of the azo pigment include azo lakes, insoluble azo pigments, condensed azo pigments, and chelate azo pigments. Examples of the polycyclic pigment include phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, and quinofullerone pigments. Examples of the dye chelate include basic dye chelate and acid dye chelate.

There is no restriction | limiting in particular as a color of the said coloring agent, 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 and organic pigments such as aniline black (CI Pigment Black 1).

  Examples of the color are C.I. I. Pigment Yellow 1, 3, 12, 13, 14, 17, 24, 34, 35, 37, 42 (yellow iron oxide), 53, 55, 74, 81, 83, 95, 97, 98, 100, 101, 104 , 408, 109, 110, 117, 120, 128, 138, 150, 151, 153, 183, C.I. I. Pigment orange 5, 13, 16, 17, 36, 43, 51, C.I. I. Pigment Red 1, 2, 3, 5, 17, 22, 23, 31, 38, 48: 2, 48: 2 (Permanent Red 2B (Ca)), 48: 3, 48: 4, 49: 1, 52: 2, 53: 1, 57: 1 (Brilliant Carmine 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81, 83, 88, 101 (Bengara), 104, 105, 106, 108 ( Cadmium red), 112, 114, 122 (quinacridone magenta), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 185, 190, 193, 209, 219, C.I. I. Pigment violet 1 (rhodamine lake), 3, 5: 1, 16, 19, 23, 38, C.I. I. Pigment Blue 1, 2, 15 (phthalocyanine blue), 15: 1, 15: 2, 15: 3 (phthalocyanine blue), 16, 17: 1, 56, 60, 63; I. Pigment green 1, 4, 7, 8, 10, 17, 18, 36, and the like.

  The self-dispersing pigment of the first form is surface-modified so that at least one hydrophilic group is bonded to the surface of the pigment directly or through another atomic group. In the surface modification, a specific functional group (a functional group such as a sulfone group or a carboxyl group) is chemically bonded to the surface of the pigment, or at least one of hypohalous acid and a salt thereof is used. A method such as wet oxidation is used. Among these, a form in which a carboxyl group is bonded to the surface of the pigment and dispersed in water is particularly preferable. Since the pigment is thus surface-modified and the carboxyl group is bonded, not only the dispersion stability is improved, but also high-quality print quality is obtained and the water resistance of the recording medium after printing is further improved. improves.

  Further, since the ink containing the self-dispersing pigment of the first form is excellent in redispersibility after drying, clogging does not occur even when printing is stopped for a long time and ink moisture near the inkjet head nozzle evaporates. Good printing can be easily performed with a simple cleaning operation.

The volume average particle size (D ₅₀ ) of the self-dispersing pigment is preferably 0.01 μm to 0.16 μm in the ink.

For example, as the self-dispersing carbon black, those having ionicity are preferable, and those having an anionic charge or those charged in a cationic form are suitable.
Examples of the anionic hydrophilic group include —COOM, —SO ₃ M, —PO ₃ HM, —PO ₃ M ₂ , —SO ₂ NH ₂ , —SO ₂ NHCOR (where M is a hydrogen atom, an alkali metal) And R represents an alkyl group having 1 to 12 carbon atoms, a phenyl group which may have a substituent, or a naphthyl group which may have a substituent. Among these, it is preferable to use those in which —COOM and —SO ₃ M are bonded to the surface of the color pigment.
Further, “M” in the hydrophilic group includes, for example, lithium, sodium, potassium and the like as an alkali metal. Examples of the organic ammonium include mono to trimethyl ammonium, mono to triethyl ammonium, and mono to trimethanol ammonium. As a method of obtaining the anionically charged color pigment, as a method of introducing —COONa to the color pigment surface, for example, a method of oxidizing the color pigment with sodium hypochlorite, a method of sulfonation, a diazonium salt The method of making it react is mentioned.
As the cationic hydrophilic group, for example, a quaternary ammonium group is preferable, and the quaternary ammonium groups listed below are more preferable. Suitable as a material.

  The method for producing the cationic self-dispersing carbon black to which the hydrophilic group is bonded is not particularly limited and may be appropriately selected depending on the intended purpose. For example, N-ethyl represented by the following structural formula An example of a method for bonding a pyridyl group is a method of treating carbon black with 3-amino-N-ethylpyridinium bromide.

The hydrophilic group may be bonded to the surface of the carbon black through another atomic group. Examples of other atomic groups include an alkyl group having 1 to 12 carbon atoms, a phenyl group which may have a substituent, or a naphthyl group which may have a substituent. Specific examples of the case where the above-described hydrophilic group is bonded to the surface of carbon black via another atomic group include, for example, —C ₂ H ₄ COOM (where M represents an alkali metal or quaternary ammonium). ), - PhSO ₃ M (however, Ph is a phenyl group .M represents an alkali metal or quaternary _{ammonium), - C 5 H 10 NH} 3 + , and the like.

In the second embodiment, the colorant is a pigment dispersion containing a pigment such as an inorganic pigment, an organic pigment, and a composite pigment, a pigment dispersant, and a polymer dispersion stabilizer, and the polymer The dispersion stabilizer is selected from an α-olefin-maleic anhydride copolymer, a styrene- (meth) acrylic copolymer, a water-soluble polyurethane resin and a water-soluble polyester resin represented by the following general formula (A). At least one.
However, in said general formula (A), R represents a C6-C30, Preferably 12-22, More preferably, it represents an 18-22 alkyl group. n represents an integer of 1 or more, and an integer of 20 to 100 is preferable.

  The polymer dispersion stabilizer is an effective material for stably maintaining the dispersion state of the pigment dispersion uniformly finely dispersed in water by the pigment dispersant. The α-olefin maleic anhydride copolymer, styrene- (meth) acrylic copolymer, water-soluble polyurethane resin and water-soluble polyester resin represented by the general formula (A) are solid at room temperature, and are used in cold water. Is insoluble. However, the dispersion stabilizer is used when dissolved in an alkali solution or an aqueous alkali solution equal to or more than the acid value of the copolymer and the resin (preferably 1.0 to 1.5 times the acid value). As an effect.

  Moreover, in order to melt | dissolve the said copolymer and the said resin with an alkali solution or aqueous alkali solution, it can melt | dissolve easily by heating and stirring. However, when the olefin chain in the α-olefin-maleic anhydride copolymer is long, it is relatively difficult to dissolve, and insoluble matter may remain. However, if the insoluble matter is removed with an appropriate filter or the like, the dispersion can be stabilized. The effect as an agent is not impaired.

  Examples of the base in the alkali solution or aqueous alkali solution include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide; basic substances such as ammonia, triethylamine and morpholine; triethanolamine, diethanolamine, Examples thereof include alcohol amines such as N-methyldiethanolamine, 2-amino-2-ethyl-1,3-propanediol, and choline.

  As the α-olefin-maleic anhydride copolymer represented by the general formula (A), those appropriately synthesized may be used, or commercially available products may be used. Examples of the commercially available products include T-YP112, T-YP115, T-YP114, T-YP116 (all manufactured by Seiko PMC Corporation).

  As the styrene- (meth) acrylic copolymer, an appropriately synthesized product or a commercially available product may be used. Examples of the commercially available products include JC-05 (manufactured by Seiko PMC Co., Ltd.), ARUFON UC-3900, ARUFON UC-3910, ARUFON UC-3920 (all manufactured by Toagosei Co., Ltd.) and the like.

  As said water-soluble polyurethane resin, what was synthesize | combined suitably may be used and a commercial item may be used. As this commercial item, Takerak W-5025, Takerak W-6010, Takerak W-5661 (all are the Mitsui Takeda Chemical Co., Ltd. product) etc. are mentioned, for example.

  As said water-soluble polyester resin, what was synthesize | combined suitably may be used and a commercial item may be used. Examples of the commercially available products include Nichigo Polyester W-0030, Nichigo Polyester W-0005S30WO, Nichigo Polyester WR-961 (all manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), pesresin A-210, pesresin A-520. (Both are manufactured by Takamatsu Yushi Co., Ltd.).

  The acid value of the polymer dispersion stabilizer is preferably 40 mgKOH / g to 400 mgKOH / g, more preferably 60 mgKOH / g to 350 mgKOH / g. When the acid value is less than 40 mg KOH / g, the solubility of the alkaline solution may be inferior. When the acid value exceeds 400 mg KOH / g, the viscosity of the pigment becomes high, and the discharge tends to be deteriorated. Stability may be easily reduced.

  The weight average molecular weight of the polymer dispersion stabilizer is preferably 20,000 or less, and more preferably 5,000 to 20,000. When the weight average molecular weight is less than 5,000, the dispersion stability of the pigment dispersion may be lowered. When the weight average molecular weight is more than 20,000, the solubility of the alkaline solution is deteriorated or the viscosity is increased. May end up.

  The content of the polymer dispersion stabilizer is preferably 1 part by mass to 100 parts by mass (solid content conversion), and more preferably 5 parts by mass to 50 parts by mass with respect to 100 parts by mass of the pigment. If the content is less than 1 part by mass, the effect of stabilizing the dispersion may be lost. If the content exceeds 100 parts by mass, the ink viscosity becomes high and the discharge performance from the nozzle tends to be deteriorated. May be inferior.

<Pigment dispersant>
In the second embodiment, the colorant preferably contains a pigment dispersant. As the pigment dispersant, either an anionic surfactant or a nonionic surfactant having an HLB value of 10 to 20 is suitable.

Examples of the anionic surfactants include polyoxyethylene alkyl ether acetates, alkylbenzene sulfonates (eg NH ₄ , Na, Ca etc.), alkyl diphenyl ether disulfonates (eg NH ₄ , Na, Ca etc.), Dialkyl succinate sulfonic acid Na salt, naphthalene sulfonic acid formalin condensate Na salt, polyoxyethylene polycyclic phenyl ether sulfate salt (eg NH ₄ , Na etc.), laurate, polyoxyethylene alkyl ether sulfate salt, oleic acid Examples include salt. Among these, dioctyl sulfosuccinic acid Na salt and polyoxyethylene styrene phenyl ether sulfonic acid NH ₄ salt are particularly preferable.

  Examples of the nonionic surfactant having an HLB value of 10 to 20 include polyoxyethylene alkyl ether, polyoxyalkylene alkyl ether, polyoxyethylene polycyclic phenyl ether, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene Examples include ethylene alkyl phenyl ether, polyoxyethylene alkyl amine, polyoxyethylene alkyl amide, and acetylene glycol. Among these, polyoxyethylene lauryl ether, polyoxyethylene-β-naphthyl ether, polyoxyethylene sorbitan monooleate, and polyoxyethylene styrene phenyl ether are particularly preferable.

  The content of the pigment dispersant is preferably 1 part by mass to 100 parts by mass and more preferably 10 parts by mass to 50 parts by mass with respect to 100 parts by mass of the pigment. When the content of the pigment dispersant is less than 1 part by mass, the pigment may not be sufficiently fined. When the content exceeds 100 parts by mass, excess components that are not adsorbed on the pigment may become an ink physical property. This will affect the image and cause deterioration of water resistance and abrasion resistance.

  The pigment dispersion uniformly finely dispersed in water by the pigment dispersant is prepared by dissolving the pigment dispersant in an aqueous medium, then adding the pigment and thoroughly moistening, and then stirring at high speed with a homogenizer. It can be produced by a method using a dispersing machine using a ball such as a bead mill or a ball mill, a kneading dispersing machine using a shearing force such as a roll mill, an ultrasonic dispersing machine, or the like. However, after such a kneading and dispersing step, coarse particles are often contained, which may cause clogging of the ink jet nozzle and the supply path. Therefore, particles having a particle diameter of 1 μm or more using a filter or a centrifuge. Need to be removed.

The average particle diameter (D ₅₀ ) of the pigment dispersion is preferably 150 nm or less, more preferably 100 nm or less in the ink. When the average particle diameter (D ₅₀ ) exceeds 150 nm, the ejection stability is drastically reduced, and nozzle clogging and ink bending may easily occur. Further, when the average particle diameter (D ₅₀ ) is 100 nm or less, the ejection stability is improved and the chroma of the image is also improved.

  Moreover, as the water-dispersible colorant of the third form, it is preferable to use a polymer emulsion in which a pigment is contained in polymer fine particles in addition to the pigment. The polymer emulsion in which a pigment is contained in the polymer fine particle is one in which a pigment is encapsulated in the polymer fine particle, or a pigment adsorbed on the surface of the polymer fine particle. In this case, it is not necessary that all the pigments are encapsulated or adsorbed, and the pigments may be dispersed in the emulsion as long as the effects of the present invention are not impaired. Examples of the polymer forming the polymer emulsion (polymer in the polymer fine particles) include vinyl polymers, polyester polymers, polyurethane polymers, and the like. Particularly preferably used polymers are vinyl polymers and polyester polymers. Reference can be made to the polymers disclosed in JP 2000-53897 A and JP 2001-139849 A.

  In the third embodiment, a general organic pigment or a composite pigment obtained by coating inorganic pigment particles with an organic pigment or carbon black can be suitably used. The composite pigment can be produced by a method of depositing an organic pigment in the presence of inorganic pigment particles, a mechanochemical method of mechanically mixing and grinding an inorganic pigment and an organic pigment, or the like. Further, if necessary, an adhesive layer between the inorganic pigment and the organic pigment can be improved by providing a layer of an organosilane compound formed from polysiloxane and alkylsilane between the inorganic pigment and the organic pigment.

  Examples of the organic pigment include aniline black as a black pigment, and examples of color pigments include anthraquinone, phthalocyanine blue, phthalocyanine green, diazo, monoazo, pyranthrone, perylene, heterocyclic yellow, quinacridone, (thio) indigoid, and the like. Can be mentioned. Among these, carbon black, phthalocyanine pigments, quinacridone pigments, monoazo yellow pigments, disazo yellow pigments, and heterocyclic yellow pigments are particularly excellent in terms of color development.

  Representative examples of the phthalocyanine blue include copper phthalocyanine blue or a derivative thereof (CI pigment blue 15: 3, 15: 4), aluminum phthalocyanine, and the like. Examples of the quinacridone include C.I. I. Pigment orange 48, C.I. I. Pigment orange 49, C.I. I. Pigment red 122, C.I. I. Pigment red 192, C.I. I. Pigment red 202, C.I. I. Pigment red 206, C.I. I. Pigment red 207, C.I. I. Pigment red 209, C.I. I. Pigment violet 19, C.I. I. Pigment violet 42 and the like. Representative examples of the monoazo yellow include C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 109, C.I. I. Pigment yellow 128, C.I. I. And CI Pigment Yellow 151. Representative examples of the disazo yellow include C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 16, C.I. I. Pigment yellow 17 and the like. Representative examples of the heterocyclic yellow include C.I. I. Pigment yellow 117, C.I. I. Pigment yellow 138, and the like. Other suitable color pigments are described in The Color Index, 3rd edition (The Society of Dyer and Colorists, 1982).

  Examples of the inorganic pigment include titanium dioxide, silica, alumina, iron oxide, iron hydroxide, and tin oxide. The particle shape preferably has a small aspect ratio, and is most preferably spherical. The color of the inorganic pigment is preferably transparent or white when the color material is adsorbed on the surface. However, when the black color material is adsorbed on the surface, a black inorganic pigment is used. It doesn't matter. The primary particle diameter of the inorganic pigment particles is preferably 100 nm or less, and more preferably 5 to 50 nm.

  The mass ratio between the inorganic pigment particles and the organic pigment or carbon black as a colorant is preferably 3: 1 to 1: 3, and more preferably 3: 2 to 1: 2. When the amount of the coloring material is small, the color developability and coloring power may be lowered, and when the amount of the coloring material is large, the transparency and the color tone may be deteriorated.

  Color material particles obtained by coating such inorganic pigment particles with an organic pigment or carbon black include silica / carbon black composite material manufactured by Toda Kogyo Co., Ltd., silica / phthalocyanine PB15: 3 composite material, silica / disazo yellow composite material, Since silica / quinacridone PR122 composite material has a small primary average particle size, it can be suitably used.

  Here, when inorganic pigment particles having a primary particle size of 20 nm are coated with an equal amount of organic pigment, the primary particle size of this pigment is about 25 nm. If a primary dispersant can be dispersed using a suitable dispersant for this, a very fine pigment-dispersed ink having a dispersed particle diameter of 25 nm can be produced. In the composite pigment, not only the organic pigment on the surface contributes to the dispersion, but also the properties of the inorganic pigment at the center appear through a thin layer of organic pigment with a thickness of about 2.5 nm, so that both can be dispersed and stabilized simultaneously. The selection of the pigment dispersant is also important.

  The content of the colorant in the recording ink is preferably 2% by mass to 15% by mass and more preferably 3% by mass to 12% by mass in terms of solid content. If the content is less than 2% by mass, the color developability and the image density of the ink may be lowered. If the content exceeds 15% by mass, the ink is thickened and the discharge property is deteriorated. In addition, it is not preferable economically.

<Surfactant>
As the surfactant, those having a low surface tension, low penetrability, and high leveling properties are preferred, without any loss of dispersion stability, depending on the type of colorant or a combination of a water-soluble organic solvent (wetting agent). Anionic surfactants At least one selected from nonionic surfactants, silicone surfactants, and fluorine surfactants is preferred. Among these, silicone surfactants and fluorine surfactants are particularly preferable.

  As the fluorine-based surfactant, those having 2 to 16 carbon atoms substituted with fluorine are preferable, and those having 4 to 16 carbon atoms substituted with fluorine are more preferable. If the fluorine-substituted carbon number is less than 2, the effect of fluorine may not be obtained, and if it exceeds 16, problems such as ink storage stability may occur.

Examples of the fluorosurfactant include a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic acid compound, a perfluoroalkyl phosphate compound, a perfluoroalkyl ethylene oxide adduct, and a perfluoroalkyl ether group in the side chain. And a polyoxyalkylene ether polymer compound. Among these, a polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain is preferable because of its low foaming property.
More preferably, it is a fluorine-type surfactant represented by the following structural formula.
_{CF 3 CF 2 (CF 2 CF} 2) m -CH 2 CH 2 O (CH 2 CH 2 O) n H
However, m represents the integer of 0-10 in the said structural formula. n represents an integer of 1 to 40.

Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid and perfluoroalkyl sulfonate.
Examples of the perfluoroalkyl carboxylic acid compound include perfluoroalkyl carboxylic acid and perfluoroalkyl carboxylate.
Examples of the perfluoroalkyl phosphate compound include perfluoroalkyl phosphate esters, perfluoroalkyl phosphate salts, and the like.
Examples of the polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain include 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.
Examples of the salt counter ion in these fluorosurfactants include 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 and the} like.

As said fluorosurfactant, what was synthesize | combined suitably may be used and a commercial item may be used.
Examples of the commercially available products include Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, and 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); Megafac F-470, F -1405, F-474 (all manufactured by Dainippon Ink & Chemicals, Inc.); Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR (all FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW (all Made, Inc.), poly Fox PF-151N (manufactured by OMNOVA Solutions Inc.), and the like. Among these, from the point that the good print quality, particularly the color development property and the leveling property on paper are remarkably improved, FS-300 manufactured by DuPont, FT-110, FT-250, FT-251 manufactured by Neos Co., Ltd., FT-400S, FT-150, FT-400SW and Polynova PF-151N manufactured by Omninova are particularly preferred.

As specific examples of the fluorine-based surfactant, those represented by the following general 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 cation, specifically, a hydrogen atom, Li, Na, K, NH ₄ , NH ₃ CH ₂ CH ₂ OH, or , 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 formula, Rf ′ and X represent the same meaning as described above.

However, in the structural formula, Rf ′ and X represent the same meaning as described above.

(2) Nonionic fluorosurfactant
However, 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 intended purpose. However, those that do not decompose even at high pH are preferable. For example, side chain-modified polydimethylsiloxane, both-end-modified polydimethylsiloxane , One-end-modified polydimethylsiloxane, side-chain both-end-modified polydimethylsiloxane, and the like. A polyether-modified silicone surfactant having a polyoxyethylene group or a polyoxyethylene polyoxypropylene group as a modifying group is an aqueous surfactant. It is particularly preferable because it exhibits good properties as an agent.
As such a surfactant, an appropriately synthesized product or a commercially available product may be used.
As said commercial item, it can obtain easily from Big Chemie Co., Ltd., Shin-Etsu Silicone Co., Ltd., Toray Dow Corning Silicone Co., Ltd., etc., for example.

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 type surfactant, For example, KF-618, KF-642, KF-643 (all are the Shin-Etsu Chemical Co., Ltd. product) etc. are mentioned.

  Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, laurate, polyoxyethylene alkyl ether sulfate, and the like. Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxypropylene polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylphenyl ether, and polyoxyethylene alkyl. Examples include amines and polyoxyethylene alkylamides.

  The content of the surfactant in the recording ink is preferably 0.01% by mass to 3.0% 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 a surfactant may be lost. When the content exceeds 3.0% by mass, the permeability to a recording medium becomes higher than necessary. In some cases, a decrease in image density or a show-through may occur.

-Penetration agent-
The recording ink of the present invention preferably contains at least one polyol compound having 8 to 11 carbon atoms as a penetrating agent. These preferably have a solubility of between 0.2% and 5.0% by weight in 25 ° C. water. Among these, 2-ethyl-1,3-hexanediol [solubility: 4.2% (25 ° C.)], 2,2,4-trimethyl-1,3-pentanediol [solubility: 2.0% (25 ° C)] is particularly preferred.

  As other polyol compounds, as aliphatic diols, for example, 2-ethyl-2-methyl-1,3-propanediol, 3,3-dimethyl-1,2-butanediol, 2,2-diethyl-1, 3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2,4-dimethyl-2,4-pentanediol, 2,5-dimethyl-2,5-hexanediol, 5-hexene- 1,2-diol and the like can be mentioned.

  Other penetrants that can be used in combination are not particularly limited as long as they can be dissolved in the ink and adjusted to the desired physical properties, and can be appropriately selected according to the purpose. For example, diethylene glycol monophenyl ether, ethylene Alkyl and aryl ethers of polyhydric alcohols such as glycol monophenyl ether, ethylene glycol monoallyl ether, diethylene glycol monophenyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, tetraethylene glycol chlorophenyl ether, lower alcohols such as ethanol, etc. Can be mentioned.

  The content of the penetrant in the recording ink is preferably 0.1% by mass to 4.0% by mass. When the content is less than 0.1% by mass, a fast-drying property cannot be obtained and a blurred image may be obtained. When the content exceeds 4.0% by mass, the dispersion stability of the colorant is impaired, and the nozzle May become clogged easily, or the permeability to a recording medium may be increased more than necessary, resulting in a decrease in image density or through-through.

-Water dispersible resin-
The water-dispersible resin has excellent film-forming properties (image formability), high water repellency, high water resistance, and high weather resistance, and has high water resistance and high image density (high color development). Useful for. For example, a condensation synthetic resin, an addition synthetic resin, a natural polymer compound, and the like can be given.
Examples of the condensed synthetic resin include polyester resin, polyurethane resin, polyepoxy resin, polyamide resin, polyether resin, poly (meth) acrylic resin, acrylic-silicone resin, and fluorine-based resin. Examples of the addition type synthetic resin include polyolefin resins, polystyrene resins, polyvinyl alcohol resins, polyvinyl ester resins, polyacrylic acid resins, unsaturated carboxylic acid resins, and the like. Examples of the natural polymer compound include celluloses, rosins, and natural rubber.
Among these, polyurethane resin fine particles, acrylic-silicone resin fine particles, and fluorine-based resin fine particles are particularly preferable. In addition, there is no problem in using two or more kinds of the water-dispersible resins in combination.

As the fluororesin, fluororesin fine particles having a fluoroolefin unit are preferred, and among these, fluorine-containing vinyl ether resin fine particles composed of a fluoroolefin unit and a vinyl ether unit are particularly preferred.
As the fluoroolefin unit is not particularly limited and may be appropriately selected depending on the purpose, for _{example, -CF 2 CF 2 -, -} CF 2 CF (CF 3) -, - CF 2 CFCl- and Can be mentioned.
There is no restriction | limiting in particular as said vinyl ether unit, Although it can select suitably according to the objective, For example, the compound etc. which are represented with following Structural formula are mentioned.

As the fluorine-containing vinyl ether resin fine particles composed of the fluoroolefin unit and the vinyl ether unit, an alternating copolymer obtained by alternately copolymerizing the fluoroolefin unit and the vinyl ether unit is preferable.
There is no restriction | limiting in particular as such a fluorine resin fine particle, What was synthesize | combined suitably may be used and a commercial item may be used. Examples of the commercially available products include Fluorate FEM-500, FEM-600, Dickguard F-52S, F-90, F-90M, F-90N, and Aquafuran TE-5A manufactured by Dainippon Ink & Chemicals, Inc .; Asahi Glass Co., Ltd. Lumiflon FE4300, FE4500, FE4400, Asahi Guard AG-7105, AG-950, AG-7600, AG-7000, AG-1100, etc. are mentioned.
The water-dispersible resin may be used as a homopolymer, or may be used as a composite resin by being used as a copolymer. Can be used.

  As the water-dispersible resin, a resin itself having a hydrophilic group and having a self-dispersibility, or a resin itself having no dispersibility and imparted with a surfactant or a resin having a hydrophilic group can be used. . Among these, an emulsion of resin particles obtained by emulsion and suspension polymerization of an ionomer of a polyester resin or a polyurethane resin or an unsaturated monomer is optimal. In the case of emulsion polymerization of an unsaturated monomer, the resin emulsion is reacted with water to which an unsaturated monomer, a polymerization initiator, a surfactant, a chain transfer agent, a chelating agent, and a pH adjusting agent are added. Therefore, a water-dispersible resin can be easily obtained, and the desired properties can be easily produced because the resin configuration can be easily changed.

  Examples of the unsaturated monomer include unsaturated carboxylic acids, monofunctional or polyfunctional (meth) acrylic acid ester monomers, (meth) acrylic acid amide monomers, and aromatic vinyl monomers. , Vinyl cyano compound monomers, vinyl monomers, allyl compound monomers, olefin monomers, diene monomers, oligomers having unsaturated carbon, etc., alone or in combination Can do. By combining these monomers, the properties can be flexibly modified, and the properties of the resin can be modified by performing a polymerization reaction or a graft reaction using an oligomer type polymerization initiator.

Examples of the unsaturated carboxylic acids include acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic acid and the like.
Examples of the monofunctional (meth) acrylic acid ester monomers include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-amyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate, 2 -Ethylhexyl methacrylate, octyl methacrylate, decyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, methacryloxyethyltrimethylammonium Salt, 3-me Acryloxypropyltrimethoxysilane, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, decyl acrylate , Dodecyl acrylate, octadecyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, glycidyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, dimethylaminoethyl acrylate, acryloxyethyl trimethyl ammonium salt, and the like.

  Examples of the polyfunctional (meth) acrylic acid ester monomers include ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1, 4-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, polybutylene glycol dimethacrylate, 2,2′-bis (4-methacryloxy) Diethoxyphenyl) propane, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, polyethylene Glycol diacrylate, triethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, 1,9-nonanediol di Acrylate, polypropylene glycol diacrylate, 2,2′-bis (4-acryloxypropyloxyphenyl) propane, 2,2′-bis (4-acryloxydiethoxyphenyl) propane trimethylolpropane triacrylate, trimethylolethanetri Acrylate, tetramethylol methane triacrylate, ditrimethylol tetraacrylate, tetramethylol methane tetraacrylate, pentaerythritol tetraacrylate, Such as pentaerythritol hexaacrylate, and the like.

  Examples of the (meth) acrylic acid amide monomers include acrylamide, methacrylamide, N, N-dimethylacrylamide, methylenebisacrylamide, and 2-acrylamido-2-methylpropanesulfonic acid.

  Examples of the aromatic vinyl monomers include styrene, α-methylstyrene, vinyltoluene, 4-t-butylstyrene, chlorostyrene, vinylanisole, vinylnaphthalene, divinylbenzene, and the like.

  Examples of the vinyl cyano compound monomers include acrylonitrile and methacrylonitrile.

Examples of the vinyl monomers include vinyl acetate, vinylidene chloride, vinyl chloride, vinyl ether, vinyl ketone, vinyl pyrrolidone, vinyl sulfonic acid or a salt thereof, vinyl trimethoxysilane, and vinyl triethoxysilane.
Examples of the allyl compound monomers include allyl sulfonic acid or a salt thereof, allylamine, allyl chloride, diallylamine, diallyldimethylammonium salt, and the like.
Examples of the olefin monomers include ethylene and propylene.
Examples of the diene monomers include butadiene and chloroprene.
Examples of the oligomers having unsaturated carbon include styrene oligomers having methacryloyl groups, styrene-acrylonitrile oligomers having methacryloyl groups, methyl methacrylate oligomers having methacryloyl groups, dimethylsiloxane oligomers having methacryloyl groups, and polyesters having acryloyl groups. An oligomer etc. are mentioned.

  The water-dispersible resin has a strong alkalinity and strong acidity, which causes molecular breakage such as dispersion breakage and hydrolysis. Therefore, the pH is preferably 4 to 12, from the viewpoint of miscibility with the water-dispersible colorant, As for pH, 6-11 are more preferable, and 7-9 are still more preferable.

The average particle size (D ₅₀ ) of the water-dispersible resin is related to the viscosity of the dispersion. When the composition is the same, the viscosity at the same solid content increases as the particle size decreases. The average particle diameter (D ₅₀ ) of the water-dispersible resin is preferably 50 nm or more so that the viscosity does not become excessively high when converted into an ink.
Further, when the particle size is several tens of μm, it becomes larger than the nozzle opening of the ink jet head and cannot be used. If particles having a large particle diameter are present in the ink even if they are smaller than the nozzle opening, the discharge property is deteriorated. Therefore, the average particle diameter (D ₅₀ ) is more preferably 200 nm or less, and even more preferably 150 nm or less, in order not to inhibit the ink ejection properties.

  The water-dispersible resin has a function of fixing the water-dispersed colorant on the paper surface, and is preferably formed into a film at room temperature to improve the fixability of the color material. Therefore, it is preferable that the minimum film-forming temperature (MFT) of the water-dispersible resin is 30 ° C. or less. Further, when the glass transition temperature of the water-dispersible resin is -40 ° C. or lower, the resin film becomes more viscous and the printed matter is tacky. Therefore, the water-dispersible resin has a glass transition temperature of −30 ° C. or higher. It is preferable.

  The content of the water-dispersible resin in the recording ink is preferably 2% by mass to 30% by mass, and more preferably 5% by mass to 25% by mass in terms of solid content.

  Here, the solid content of the colorant, the pigment in the colorant, and the water-dispersible resin can be measured by, for example, a method of separating only the colorant and the water-dispersible resin from the ink. . Moreover, when the pigment is used as the colorant, the ratio of the colorant to the water-dispersible resin can be measured by evaluating the mass reduction rate by thermal mass spectrometry. In addition, when the molecular structure of the colorant is clear, the solid content of the colorant can be quantified using NMR for pigments and dyes. Inorganic pigments contained in heavy metal atoms, molecular skeletons, and metal-containing organics For pigments and metal-containing dyes, the solid content of the colorant can be quantified by using fluorescent X-ray analysis.

-Other ingredients-
The other components are not particularly limited and may be appropriately selected as necessary. For example, a pH adjuster, an antiseptic / antifungal agent, a chelating reagent, an antirust agent, an antioxidant, an ultraviolet absorber, oxygen Examples include absorbers and light stabilizers.

The pH adjuster is not particularly limited as long as the pH can be adjusted to 7 to 11 without adversely affecting the recording ink to be prepared, and can be appropriately selected according to the purpose. Examples include alcohol amines, alkali metal hydroxides, ammonium hydroxides, phosphonium hydroxides, alkali metal carbonates, and the like. If the pH is less than 7 or more than 11, the amount of the ink jet head or ink supply unit that melts out is large, and problems such as ink deterioration, leakage, and ejection failure may occur.
Examples of the alcohol amines include diethanolamine, triethanolamine, 2-amino-2-ethyl-1,3-propanediol, and the like.
Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, and potassium hydroxide.
Examples of the ammonium hydroxide include ammonium hydroxide, quaternary ammonium hydroxide, quaternary phosphonium hydroxide, and the like.
Examples of the alkali metal carbonate include lithium carbonate, sodium carbonate, and potassium carbonate.

  Examples of the antiseptic / antifungal agent include sodium dehydroacetate, sodium sorbate, 2-pyridinethiol-1-oxide sodium, sodium benzoate, sodium pentachlorophenol and the like.

  Examples of the chelating reagent include sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, sodium uramil diacetate, and the like.

  Examples of the rust inhibitor include acidic sulfite, sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite.

Examples of the antioxidant include phenolic antioxidants (including hindered phenolic antioxidants), amine-based antioxidants, sulfur-based antioxidants, phosphorus-based antioxidants, and the like.
Examples of the phenolic antioxidant (including hindered phenolic antioxidant) 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-tri (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) Examples include benzene, tetrakis [methylene-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate] methane.
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, 1,1,3-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, and 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, and trinonylphenyl phosphite.

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 ultraviolet absorber include nickel bis (octylphenyl) sulfide, 2,2′-thiobis (4-tert-octylferrate) -n-butylamine nickel (II), 2,2′-thiobis. (4-tert-octylferrate) -2-ethylhexylamine nickel (II), 2,2′-thiobis (4-tert-octylferrate) triethanolamine nickel (II) and the like.

  The recording ink of the present invention includes a water-soluble organic solvent (wetting agent), a colorant, a surfactant, and water, and if necessary, a penetrant, a water-dispersible resin, and other components dispersed in an aqueous medium. Or it melt | dissolves and also stirs and mixes as needed. The dispersion can be performed by, for example, a sand mill, a homogenizer, a ball mill, a paint shaker, an ultrasonic disperser, etc., and stirring and mixing are performed by a stirrer using a normal stirring blade, a magnetic stirrer, a high-speed disperser, or the like. be able to.

  The physical properties of the recording ink of the present invention are not particularly limited and may be appropriately selected depending on the intended purpose. For example, the viscosity, surface tension, pH and the like are preferably in the following ranges.

The viscosity of the recording ink at 25 ° C. is preferably 5 mPa · s to 25 mPa · s. By setting the ink viscosity to 5 mPa · s or more, the effect of improving the printing density and the character quality can be obtained. On the other hand, by suppressing the ink viscosity to 25 mPa · s or less, it is possible to ensure dischargeability.
Here, the said viscosity can be measured at 25 degreeC, for example using a viscometer (RE-550L, Toki Sangyo Co., Ltd. make).
The surface tension of the recording ink is preferably 35 mN / m or less, more preferably 32 mN / m or less at 25 ° C. When the surface tension exceeds 35 mN / m, leveling of the ink on the recording medium is difficult to occur, and the drying time may be prolonged.
The pH of the recording ink is preferably 7 to 12, for example, and more preferably 8 to 11 from the viewpoint of preventing corrosion of the metal member in contact with the liquid.

  There is no restriction | limiting in particular as coloring of the recording ink of this invention, 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 recording ink of the present invention uses an piezoelectric head as a pressure generating means for pressurizing ink in an ink flow path as an ink jet head, and deforms a diaphragm that forms the wall surface of the ink flow path to increase the volume in the ink flow path. A so-called piezo type that discharges ink droplets by changing (refer to Japanese Patent Laid-Open No. 2-51734), or a so-called thermal type that generates bubbles by heating ink in an ink flow path using a heating resistor. (Refer to Japanese Patent Application Laid-Open No. 61-59911), a diaphragm that forms the wall surface of an ink flow path and an electrode are arranged opposite to each other, and the diaphragm is deformed by an electrostatic force generated between the diaphragm and the electrode. Thus, any ink jet head such as an electrostatic type (see Japanese Patent Laid-Open No. 6-71882) for discharging ink droplets by changing the volume of the ink flow path is mounted. It is also good to use in the printer.

  The recording ink of the present invention can be suitably used in various fields such as an ink jet recording ink, a fountain pen, a ballpoint pen, a magic pen, and a sign pen, and is particularly suitable for an image recording apparatus (printer or the like) using an ink jet recording method. For example, the recording paper and the recording ink can be heated at 50 to 200 ° C. before or after printing or printing, and can be used for a printer having a function of promoting print fixing. The ink medium set, the ink cartridge of the present invention, the ink jet recording method, the ink jet recording apparatus, and the ink recorded matter can be particularly preferably used.

<Ink media set>
The ink media set used in the present invention is a combination of the recording ink of the present invention and a recording medium.

<< Recording media >>
The recording medium is not particularly limited and can be appropriately selected according to the purpose. For example, plain paper, glossy paper, special paper, cloth, film, OHP sheet, general-purpose printing paper can be suitably used. It is.
Among these, in order to obtain a very beautiful ink recorded material such as a printed image, it has a support and a coating layer coated on at least one surface of the support, metastasis amount to the recording medium of pure water at the scanning absorptometer contact time 100ms measured by is ^{1mL / m 2 ~10mL / m 2} , and the pure water at a contact time 400ms to said recording medium transfer amount is the recording medium of ^3mL / ^{m 2 ~25mL} / m 2 is used.
The transfer amount of pure water to the recording medium at a contact time of 100 ms measured with the dynamic scanning absorption meter is more preferably ² mL / m ^{2 to} 10 mL / m ² , and the pure water recording medium at a contact time of 400 ms. transfer amount to the ^3mL / ^{m 2 ~20mL} / m 2 is more preferable.
If the transfer amount of the ink and pure water at the contact time of 100 ms is too small, beading (density unevenness) is likely to occur. If too much, the ink dot diameter after recording is larger than the desired diameter. May be too small.
If the transfer amount of the ink and pure water at the contact time of 400 ms is too small, the drying property is insufficient, so that spur marks are likely to be generated. May become low.

  Here, the dynamic scanning absorptiometer (DSA, Kojipa Gakkai, Vol. 48, May 1994, pp. 88-92, Kuju Shigenori) has 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 values of the transfer amount at the contact time adjacent to the contact time.

-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 is to remove foreign matter (plastic etc.) and dust contained in waste paper with a screen, cleaner or the like.
(3) In the deinking, the printing ink 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, melamine Examples thereof include organic pigments such as resins. 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 medium tends to be slippery, which may be undesirable from the viewpoint of transportability during ink jet recording. .

There is no restriction | limiting in particular in the thickness of the said support body, Although it can select suitably according to the objective, 50 micrometers-300 micrometers are preferable. The basis weight of the support ^{is, 45g / m 2 ~290g / m} 2 is preferred.

-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 has excellent glossiness and can be made close to a 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 proportion of particle size of 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 thickening under a 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 parts by mass 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 has a solid type, a hollow type, a donut type and the like in its form, but in view of the balance of gloss development, surface covering property and fluidity of the coating liquid, the average particle size (D ₅₀ ) Is preferably 0.2 μm to 3.0 μm, more preferably a hollow mold having a porosity of 40% or more is adopted.

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; cells such as carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, etc. Cellulose modified products such as cationized hydroxyethyl cellulose; polyester, polyacrylic acid (ester), melamine resin, or synthetic resins such as these, modified polyester and polyurethane copolymers; poly (meth) acrylic acid , Poly (meth) acrylamide, oxidized starch, phosphate esterified starch, self-modified starch, cationized starch, or various modified starches, polyethylene oxide, sodium polyacrylate, sodium alginate and the like. 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, and a copolymer of polyester and polyurethane 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 Examples include coalescence. 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, it is not always necessary to add a cationic organic compound to the coating layer, but the cationic organic compound to be added to the coating layer is not particularly limited. And can be appropriately selected and used depending on the purpose. Examples of the cationic organic compound blended in the coating layer include a first grade that reacts with a direct dye in a water-soluble ink or a sulfonic acid group, a carboxyl group, an amino group, or the like in an acid dye to form an insoluble salt. ˜tertiary amine, quaternary ammonium salt monomer, oligomer, polymer and the like. 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 feathering compared to 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 less than 0.3 g / m ² , sufficient image density improvement and feathering reduction effects may not be obtained.

  The surfactant contained in the coating layer as needed is not particularly limited and may be appropriately selected depending on the intended purpose. However, anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic activity Any of the agents 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 adducts, alkylphenol ethylene oxide adducts, fatty acid ethylene oxide adducts, polyhydric alcohol fatty acid ester ethylene oxide adducts, higher aliphatic amine ethylene oxide adducts, and fatty acid amides. 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, Examples include 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 10 parts by mass or less, 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 coating, it may be dried as necessary. In this case, the drying temperature is not particularly limited and may be appropriately selected depending on the intended purpose. preferable.

  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.

As the recording medium, commercially available general-purpose printing paper, coated paper for offset printing, coated paper for gravure printing, and the like can be used in addition to inkjet recording media.
Commercially available coated coated paper refers to cast coated paper, so-called art paper (A0 size, A1 size), A2 size coated paper, A3 size coated paper, B2 size coated paper, lightweight coated paper, and fine coated paper. It is a coated paper used for printing / publishing printing, and is used for offset printing, gravure printing, and the like.
Specifically, an aurora coat, space DX (made by Nippon Paper Industries Co., Ltd.), POD gloss coat (made by Oji Paper Co., Ltd.), etc. are mentioned.

(ink cartridge)
The ink cartridge of the present invention contains the recording ink of the present invention in a container, and further includes other members and the like 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. What has is mentioned suitably.
Next, the ink cartridge will be described with reference to FIGS. Here, FIG. 1 is a schematic diagram showing an ink cartridge 201 of the present invention, and FIG. 2 is a schematic diagram showing a modification of the ink cartridge of FIG.
As shown in FIG. 1, after the recording ink of the present invention is filled into the ink bag 241 from the ink inlet 242 and exhausted, the ink inlet 242 is closed by fusion. In use, the ink discharge port 243 made of a rubber member is pierced with a needle of an ink jet recording apparatus main body 101 described later with reference to FIG.
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.
The ink cartridge 201 of the present invention contains the recording ink of the present invention and can be used by being detachably mounted on various ink jet recording apparatuses, and is also detachably mounted on the ink jet recording apparatus of the present invention described later. It is particularly preferable to use them.

(Inkjet recording method and inkjet recording apparatus)
The ink jet recording method of the present invention includes at least an ink flying process and further includes other processes appropriately selected as necessary, for example, a stimulus generation process, a control process, and the like.
The ink jet recording apparatus of the present invention includes at least ink flying means, and further includes other means appropriately selected as necessary, for example, stimulus generation means, control means, and the like.
The ink jet recording method of the present invention can be preferably carried out by the ink jet recording apparatus of the present invention, and the ink flying step can be suitably carried out by the ink flying means. Moreover, the said other process can be suitably performed by the said other means.

-Ink flying process and ink flying means-
The ink flying step is a step of forming an image on a recording medium by applying a stimulus (energy) to the recording ink of the present invention and causing the recording ink to fly.
The ink flying means is means for applying an stimulus (energy) to the recording ink of the present invention and causing the recording ink to fly to form an image on a recording medium. The ink flying means is not particularly limited, and examples thereof include various nozzles for ejecting ink.
As the recording medium, the recording medium in the ink media set can be used.
In the present invention, it is preferable that at least a part of the liquid chamber portion, the fluid resistance portion, the vibration plate, and the nozzle member of the inkjet head is formed of a material containing at least one of silicone and nickel.
The nozzle diameter of the inkjet nozzle is preferably 30 μm or less, and more preferably 1 μm to 20 μm.

  The stimulus (energy) can be generated by, for example, the stimulus generating means, and the stimulus is not particularly limited and can be appropriately selected according to the purpose. For example, heat (temperature), pressure, Examples include vibration and light. 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, An electrostatic actuator using an electrostatic force can be used.

  There are no particular restrictions on the manner in which the recording ink flies, and it varies depending on the type of the stimulus. For example, when the stimulus is “heat”, a recording signal is output to the recording ink in the recording head. Corresponding thermal energy is applied using, for example, a thermal head, bubbles are generated in the recording ink by the thermal energy, and the recording ink is formed into droplets from the nozzle holes of the recording head by the pressure of the bubbles. And a method of discharging and jetting. 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 the recording ink is ejected and ejected as droplets from the nozzle holes of the recording head.

The size of the recording ink droplets to be ejected is preferably 3 × 10 ⁻¹⁵ to 40 × 10 ⁻¹⁵ m ³ ( ³ to 40 pL), for example. Is preferably 5 m / s to 20 m / s, its driving frequency is preferably 1 kHz or more, and its resolution is preferably 300 dpi or more.
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 using a serial type ink jet recording apparatus will be described with reference to the drawings. The ink jet recording apparatus shown in FIG. 3 has an apparatus main body 101, a paper feed tray 102 for loading paper into the apparatus main body 101, and a sheet for forming (recording) an image formed (recorded) on the apparatus main body 101. A paper discharge tray 103 and an ink cartridge loading unit 104 are provided. 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). It is held movably and moved and scanned in the direction of the arrow in FIG. 5 by a main scanning motor (not shown).
The carriage 133 includes a plurality of ink jet recording heads 134 including four ink jet recording heads that eject recording ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (Bk). The ejection ports are arranged in a direction crossing the main scanning direction, and are mounted with the ink droplet ejection direction facing 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, etc. 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.

In addition, 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 recording ink of the present invention from the ink cartridge 201 of the present invention loaded in the ink cartridge loading section 104 via a recording ink supply tube (not shown).
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 feeding tray 102, a half-moon roller (feeding) that separates and feeds the paper 142 from the paper stacking unit 141 one by one. 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 fed via the transport belt 151 with the transport belt 151 and the paper 142 fed substantially vertically upward are changed by approximately 90 ° so as 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 adsorption 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 same surface layer. It has a back layer (medium resistance layer, earth layer) that has been subjected to resistance control with carbon as a material. On the back side of the conveyance belt 151, a guide member 161 is arranged corresponding to a printing area by the recording head 134. Note that, 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 conveyance 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 the recording ink remaining amount near end in the sub tank 135 is detected, a required amount of recording ink is supplied from the ink cartridge 201 to the sub tank 135.

  In this ink jet recording apparatus, when the recording ink in the ink cartridge 201 of the present invention is used up, the housing of the ink cartridge 201 can be disassembled and only the ink bag 241 inside can be replaced. Further, the ink cartridge 201 can supply recording ink stably even when the ink cartridge 201 is placed vertically and has a front loading configuration. Therefore, the ink cartridge 201 can be replaced even when the upper portion of the apparatus main body 101 is closed, for example, when stored in a rack, or when an object is placed on the upper surface of the apparatus main body 101. Can be easily performed.

  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.

  Further, 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 applicable to, for example, an ink jet recording printer, a facsimile apparatus, a copying apparatus, a printer / fax / copier multifunction machine, and the like. It can be suitably applied.

(Ink record)
The recorded matter recorded by the ink jet recording apparatus and 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 recording ink of the present invention.
The ink recorded matter of the present invention has an image formed on the recording medium in the ink media set using the recording ink 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, glossy paper, special paper, cloth, film, OHP sheet, and general-purpose printing paper. These may be used individually by 1 type and may use 2 or more types together.
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.

(Production Example 1)
In a 300 mL separable flask equipped with a stirrer, a thermocouple, and a nitrogen gas inlet tube, 19.828 g of N, N-dimethylacrylamide and 14.824 g of 1-butanol were added and stirred while introducing nitrogen gas.
Next, 0.338 g of sodium t-butoxide was added, and the reaction was performed at 35 ° C. for 4 hours.
After completion of heating, 150 mg of phosphoric acid was added to make the solution uniform, and the mixture was allowed to stand for 3 hours. The solution was filtered to remove precipitates, and unreacted substances were removed with an evaporator. The yield was 30.5 g (88% yield).
When ¹ H-NMR of the obtained substance was measured, it was 0.95 ppm (3H), 1.3 to 1.5 ppm (4H), 2.4 ppm (2H), 2.9 ppm (6H), 3.4 ppm ( 2H) and 3.7 ppm (2H) were observed. As a result, it was found that the compound was represented by the following structural formula (ii).

(Production Example 2)
In a 300 mL separable flask equipped with a stirrer, a thermocouple, and a nitrogen gas inlet tube, 19.828 g of N, N-dimethylacrylamide and 20.434 g of 1-hexanol were added and stirred while introducing nitrogen gas.
Next, 0.338 g of sodium t-butoxide was added, and the reaction was performed at 35 ° C. for 4 hours. After completion of heating, 150 mg of phosphoric acid was added to make the solution uniform, and the mixture was allowed to stand for 3 hours. The solution was filtered to remove precipitates, and unreacted substances were removed with an evaporator. The yield was 37.4 g (93% yield).
When ¹ H-NMR of the obtained substance was measured, it was 0.95 ppm (3H), 1.3 to 1.5 ppm (8H), 2.4 ppm (2H), 2.9 ppm (6H), 3.4 ppm ( 2H) and 3.7 ppm (2H) were observed. As a result, it was found that the compound was represented by the following structural formula (iii).

(Preparation Example 1)
-Preparation of water-soluble polymer compound aqueous solution A-
Α-olefin-maleic anhydride copolymer (manufactured by Seiko PMC Co., Ltd., T-YP112, olefin chain: carbon number 20-24 (R in the general formula (A) is an alkyl group having 18-22 carbon atoms), Acid value 190 mgKOH / g, weight average molecular weight = 10,000)... 10.0 parts by mass-1N aqueous LiOH solution (of the α-olefin-maleic anhydride copolymer represented by the general formula (A)) Acid amount 1.2 times)) 17.34 parts by mass Ion-exchanged water 72.66 parts by mass

  Next, the mixture is heated and stirred with a stirrer to dissolve the α-olefin-maleic anhydride copolymer represented by the general formula (A), and a small amount of insoluble matter is filtered through a filter having an average pore size of 5 μm. A water-soluble polymer compound aqueous solution A was prepared.

(Preparation Example 2)
-Preparation of surface-treated black pigment dispersion-
90 g of carbon black having a CTAB specific surface area of 150 m ² / g and DBP oil absorption of 100 mL / 100 g is added to 3,000 mL of 2.5 N sodium sulfate solution, stirred at a temperature of 60 ° C. and a speed of 300 rpm, and allowed to react for 10 hours. The oxidation treatment was performed. The reaction solution was filtered, and the carbon black separated by filtration was neutralized with a sodium hydroxide solution and subjected to ultrafiltration.
The obtained carbon black was washed with water, dried, dispersed in pure water to a solid content of 30% by mass, and sufficiently stirred to obtain a black pigment dispersion. The average particle diameter (D ₅₀ ) of the pigment dispersion in this black pigment dispersion was measured and found to be 103 nm. The average particle diameter (D ₅₀ ) was measured using a particle size distribution measuring device (Nikkiso Co., Ltd., Nanotrac UPA-EX150).

(Preparation Example 3)
-Preparation of polymer fine particle dispersion containing magenta pigment-
<Preparation of polymer solution A>
After sufficiently replacing the inside of a 1 L flask equipped with a mechanical stirrer, thermometer, nitrogen gas inlet 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 dropping, 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 dispersion>
28 g of the polymer solution A, C.I. I. 42 g of CI Pigment Red 122, 13.6 g of a 1 mol / L potassium hydroxide aqueous solution, 20 g of methyl ethyl ketone, and 13.6 g of ion-exchanged water were sufficiently stirred, and then kneaded using a roll mill. The obtained paste was put into 200 g of pure water and stirred sufficiently. Then, the ethyl ethyl ketone and water were distilled off using an evaporator, and the dispersion was further treated with polyvinylidene fluoride having an average pore size of 5.0 μm to remove coarse particles. By pressure filtration with a ride membrane filter, a magenta pigment-containing polymer fine particle dispersion containing 15% by mass of pigment and 20% by mass of solid was obtained.
The average particle diameter (D ₅₀ ) of the polymer particles in the obtained magenta pigment-containing polymer particle dispersion was measured and found to be 127 nm. The average particle diameter (D ₅₀ ) was measured using a particle size distribution measuring device (Nikkiso Co., Ltd., Nanotrac UPA-EX150).

(Preparation Example 4)
-Preparation of Cyan Pigment-Containing Polymer Fine Particle Dispersion-
In Preparation Example 3, C.I. I. A cyan pigment-containing polymer fine particle dispersion was prepared in the same manner as in Preparation Example 3, except that Pigment Red 122 was replaced with a phthalocyanine pigment (CI Pigment Blue 15: 3).
With respect to the polymer fine particles in the obtained cyan pigment-containing polymer fine particle dispersion, the average particle diameter (D ₅₀ ) measured by a particle size distribution analyzer (manufactured by Nikkiso Co., Ltd., Nanotrack UPA-EX150) was 93 nm.

(Preparation Example 5)
-Preparation of yellow pigment-containing polymer fine particle dispersion-
In Preparation Example 3, C.I. I. A yellow pigment-containing polymer fine particle dispersion was prepared in the same manner as in Preparation Example 3, except that Pigment Red 122 was replaced with a monoazo yellow pigment (CI Pigment Yellow 74).
About the polymer fine particles in the obtained yellow pigment-containing polymer fine particle dispersion, the average particle size (D ₅₀ ) measured by a particle size distribution analyzer (manufactured by Nikkiso Co., Ltd., Nanotrac UPA-EX150) was 76 nm.

(Preparation Example 6)
-Preparation of carbon black pigment-containing polymer fine particle dispersion-
In Production Example 3, C.I. I. A carbon black pigment-containing polymer fine particle dispersion was prepared in the same manner as in Preparation Example 3, except that Pigment Red 122 was replaced with carbon black (FW 100, manufactured by Degussa).
About the polymer fine particles in the obtained carbon black pigment-containing polymer fine particle dispersion, the average particle size (D ₅₀ ) measured by a particle size distribution measuring device (Nanotrack UPA-EX150, manufactured by Nikkiso Co., Ltd.) was 104 nm.

(Preparation Example 7)
-Preparation of yellow pigment surfactant dispersion-
-Monoazo yellow pigment (CI Pigment Yellow 74, manufactured by Dainichi Seika Kogyo Co., Ltd.)-30.0 parts by mass-Polyoxyethylene styrene phenyl ether (nonionic surfactant, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) Neugen EA-177, HLB value = 15.7) ... 10.0 parts by mass Ion-exchanged water ... 60.0 parts by mass

First, when the surfactant is dissolved in ion-exchanged water and the pigment is mixed and sufficiently moistened, a wet disperser (Dynomill KDL A type, manufactured by WAB) is filled with zirconia beads having a diameter of 0.5 mm. Dispersion was performed at 2,000 rpm for 2 hours to obtain a primary pigment dispersion.
Next, as a water-soluble polymer compound aqueous solution in the primary pigment dispersion, water-soluble polyurethane resin (Takelac W-5661, manufactured by Mitsui Takeda Chemical Co., Ltd., active ingredient 35.2% by mass, acid value 40 mgKOH / g, molecular weight 18, No. 000) was added and stirred sufficiently to obtain a yellow pigment surfactant dispersion. The average particle diameter of the pigment dispersion in the resulting yellow pigment surfactant dispersion (D ₅₀₎ was 62nm was measured. The average particle diameter (D ₅₀ ) was measured using a particle size distribution measuring device (Nikkiso Co., Ltd., Nanotrac UPA-EX150).

(Preparation Example 8)
-Preparation of a magenta pigment surfactant dispersion-
-Quinacridone pigment (CI Pigment Red 122, manufactured by Dainichi Seika Kogyo Co., Ltd.)-30.0 parts by mass-Polyoxyethylene-β-naphthyl ether (nonionic surfactant, manufactured by Takemoto Yushi Co., Ltd., RT −100, HLB value = 18.5)... 10.0 mass parts ・ Ion-exchanged water ... 60.0 mass parts

First, when the surfactant is dissolved in ion-exchanged water and the pigment is mixed and sufficiently moistened, a wet disperser (Dynomill KDL A type, manufactured by WAB) is filled with zirconia beads having a diameter of 0.5 mm. Dispersion was performed at 2,000 rpm for 2 hours to obtain a primary pigment dispersion.
Next, a water-soluble styrene- (meth) acrylic copolymer (JC-05, manufactured by Seiko PMC Co., Ltd., active ingredient 21% by mass, acid value 170 mgKOH / g, weight average molecular weight 16,000) was added to the primary pigment dispersion. .14 parts by mass was added and sufficiently stirred to obtain a magenta pigment surfactant dispersion. The average particle diameter (D ₅₀ ) of the pigment dispersion in the obtained magenta pigment surfactant dispersion was measured and found to be 83 nm. The average particle diameter (D ₅₀ ) was measured using a particle size distribution measuring device (Nikkiso Co., Ltd., Nanotrac UPA-EX150).

(Preparation Example 9)
-Preparation of Cyan Pigment Surfactant Dispersion A-
-Phthalocyanine pigment (CI Pigment Blue 15: 3, manufactured by Dainichi Seika Kogyo Co., Ltd.)-30.0 parts by mass-Polyoxyethylene styrene phenyl ether (nonionic surfactant, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) Neugen EA-177, HLB value = 15.7)... 10.0 parts by mass. Ion-exchanged water... 60.0 parts by mass.

First, the surfactant is dissolved in ion-exchanged water, and when the pigment is mixed and sufficiently moistened, a wet disperser (Dynomill KDL A type, manufactured by WAB) is filled with zirconia beads having a diameter of 0.5 mm, Dispersion was performed at 2,000 rpm for 2 hours to obtain a primary pigment dispersion.
Next, 7.51 parts by mass of the water-soluble polymer compound aqueous solution A of Preparation Example 1 and a water-soluble polyester resin (Nichigo Polyester W-0030, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., active ingredient) in the primary pigment dispersion 2.51 parts by mass of 29.9% by mass, an acid value of 100 mgKOH / g, and a weight average molecular weight of 7,000) were added and stirred sufficiently to obtain a cyan pigment surfactant dispersion A. The average particle diameter of the pigment dispersion in the resulting cyan pigment surfactant dispersion A (D ₅₀₎ was 78nm was measured. The average particle diameter (D ₅₀ ) was measured using a particle size distribution measuring device (Nikkiso Co., Ltd., Nanotrac UPA-EX150).

( Reference Examples 1-15 and Comparative Examples 1-7)
-Preparation of recording ink-
Each recording ink was manufactured according to the following procedure.
First, a water-soluble organic solvent, a penetrating agent, a surfactant, an antifungal agent, and water shown in Tables 1 to 5 below were mixed, and stirred for 1 hour and mixed uniformly. A water-dispersible resin was added to the mixed solution and stirred for 1 hour, and a pigment dispersion and an antifoaming agent were added and stirred for 1 hour. This dispersion was subjected to pressure filtration with a polyvinylidene fluoride membrane filter having an average pore diameter of 0.8 μm to remove coarse particles and dust, and the recording inks of Reference Examples 1 to 15 and Comparative Examples 1 to 7 were produced. did.

Abbreviations in Tables 1 to 5 represent the following meanings.
* Acrylic-silicone resin emulsion: manufactured by Showa Polymer Co., Ltd., Polysol ROY6312, solid content 37.2% by mass, average particle diameter 171 nm, minimum film-forming temperature (MFT) = 20 ° C.
* Polyurethane emulsion: manufactured by DIC, Hydran APX-101H, solid content 45% by mass, average particle size 160 nm, minimum film-forming temperature (MFT) = 20 ° C.
* Vinyl chloride emulsion: manufactured by Nissin Chemical Industry Co., Ltd., Viniblanc 603, solid content 49.8% by mass, average particle diameter 150 nm, minimum film-forming temperature (MFT) = 63 ° C.
* KF-643: polyether-modified silicone compound (manufactured by Shin-Etsu Chemical Co., Ltd., component 100% by mass)
* Zonyl FS-300: polyoxyethylene perfluoroalkyl ether (manufactured by Dupont, 40 mass% component)
* Softanol EP-7025: polyoxyalkylene alkyl ether (manufactured by Nippon Shokubai Co., Ltd., component 100% by mass)
* Proxel GXL: Antifungal agent based on 1,2-benzisothiazolin-3-one (Avicia, 20% by mass, containing dipropylene glycol)
* KM-72F: Self-emulsifying silicone defoaming agent (manufactured by Shin-Etsu Silicone Co., Ltd., 100% by mass)

Next, the recording inks of Reference Examples 1 to 15 and Comparative Examples 1 to 7 were evaluated by the following evaluation method. The results are shown in Tables 6 and 7.

<Measurement of ink viscosity>
The viscosity of the ink was measured at an ink temperature of 25 ° C. using a viscometer (RE-550L, manufactured by Toki Sangyo Co., Ltd.).

<Measurement of ink surface tension>
The surface tension of the ink was measured at an ink temperature of 25 ° C. using a fully automatic surface tension meter (CBVP-Z, manufactured by Kyowa Interface Science Co., Ltd.).

<Measurement of pH of ink>
The pH of the ink was measured at an ink temperature of 25 ° C. using a pH meter (HM-30R, manufactured by TOA-DKK).

−Preparation for printing evaluation−
Using an ink jet printer (IPSiO GXe-5500, manufactured by Ricoh Co., Ltd.) under the environmental conditions adjusted to 23 ° C. ± 0.5 ° C. and 50 ± 5% RH, The drive voltage was varied so that the same amount of ink was applied to the recording medium.

<Discharge stability>
200 charts are continuously printed on MyPaper (manufactured by Ricoh Co., Ltd.) to fill 5% area of A4 size paper per color created with Microsoft Word 2000 (manufactured by Microsoft) with a solid image. Disturbance of each nozzle after launch It was evaluated from. The print mode used was a driver attached to the printer, in which the “plain paper-standard fast” mode was changed to “no color correction” from the user settings for plain paper.
〔Evaluation criteria〕
○: Discharge turbulence △: Discharge turbulence slightly ×: Discharge turbulence or non-discharge portion

<Image density>
A chart with 64 point characters “■” created by Microsoft Word 2000 (manufactured by Microsoft) is stamped on MyPaper (manufactured by Ricoh Co., Ltd.), and the “■” portion of the printed surface is X-Rite 939 (manufactured by X-Rite). ) And measured according to the following evaluation criteria. Table 7 shows the worst evaluation among the four colors of black, yellow, magenta, and cyan. The print mode used was a driver attached to the printer, in which the “plain paper-standard fast” mode was changed to “no color correction” from the user settings for plain paper.
〔Evaluation criteria〕
◎: Black: 1.20 or more, Yellow: 0.80 or more, Magenta: 1.00 or more, or Cyan: 1.00 or more ○: Black: 1.10 or more and less than 1.20, Yellow: 0.70 or more and 0 Less than .80, Magenta: 0.90 or more and less than 1.00, or Cyan: 0.90 or more and less than 1.00 x: Black: less than 1.10, Yellow: less than 0.70, Magenta: less than 0.90, or Cyan less than 0.90

<Saturation>
A chart similar to the image density was stamped on MyPaper (manufactured by Ricoh Co., Ltd.), the “■” portion of the printed surface was measured with X-Rite 939 (manufactured by X-Rite), and judged according to the following evaluation criteria. The printing mode used was a driver attached to the printer, in which the "plain paper-standard fast" mode was changed to "no color correction" from the user setting for plain paper. The ratio of the measured saturation value to the saturation value (yellow: 91.34, magenta: 74.55, cyan: 62.82) of the standard color (Japan color ver. 2) was calculated, and the following evaluation was performed. The color developability was judged according to the standard, and the worst evaluation among the three colors of yellow, magenta and cyan is shown in Table 7.
〔Evaluation criteria〕
(1) For yellow, ◎: 0.9 or more, ○: 0.8 or more and less than 0.9, X: less than 0.8 (2) For magenta, ◎: 0.8 or more, ○: 0.75 or more, 0 Less than 0.8, x: less than 0.75 (3) For cyan, A: 0.85 or more, B: 0.8 or more and less than 0.85, X: less than 0.8

<Evaluation of curls>
Using the prototype line head printing device shown in Fig. 7 below, solid printing is performed under the following printing conditions, and back curl (within 10 seconds after discharging from the printing device) is placed on a flat desk with the printing surface facing down. Curl height) and the curl height after leaving the printing surface face down on a flat desk for 1 day was evaluated.
(1) Evaluation printer: Prototype line head printer (see Fig. 7)
FIG. 7 is a schematic diagram showing the internal structure of the prototype line head printer.
In the image recording apparatus A, the paper feed tray 1 has a configuration in which a pressure plate 2 and a paper feed rotating body 4 for feeding recording paper 3 are attached to a base 5.
The pressure plate 2 can rotate around a rotation axis a attached to the base 5, and is urged by the pressure plate spring 6 to the sheet feeding rotator 4.
A separation pad (not shown) made of a material having a large friction coefficient, such as an artificial skin, is provided at a portion of the pressure plate 2 facing the sheet feeding rotator 4 in order to prevent double feeding of the recording paper 3.
Further, a release cam (not shown) for releasing the contact between the pressure plate 2 and the sheet feeding rotating body 4 is provided.
In the above configuration, the release cam pushes the pressure plate 2 down to a predetermined position in the standby state. As a result, the contact between the pressure plate 2 and the sheet feeding rotating body 4 is released.
In this state, when the driving force from the transport roller 7 is transmitted to the sheet feeding rotator 4 and the release cam by a gear or the like, the release cam moves away from the pressure plate 2 and the pressure plate 2 rises, and the sheet feeding rotator 4 and the recording are recorded. The paper 3 comes into contact.
The recording paper 3 is picked up and started to be fed along with the rotation of the paper feed rotating body 4 and separated one by one by a separation claw (not shown).
The sheet feeding rotator 4 rotates to feed the recording sheet 3 to the platen 10 via the conveyance guides 8 and 9.
The recording paper 3 passes between the conveyance guides 8 and 9 and is guided to the conveyance roller 7, and is conveyed to the platen 10 by the conveyance roller 7 and the pinch roller 11.
After that, the contact state between the recording paper 3 and the paper feed rotating body 4 is released again, and the driving force from the transport roller 7 is cut off.
The paper feed rotator 12 for manual paper feed feeds the recording paper 3 mounted on the manual feed tray 13 in accordance with the recording command signal of the computer and transports it to the transport roller 7.
The recording paper 3 conveyed to the platen 10 passes under the line head 14.
Here, the recording paper conveyance speed and the droplet discharge timing are adjusted based on a signal controlled by an electric circuit (not shown), thereby forming a desired image.
(2) Evaluation media: MyPaper (PPC paper) manufactured by Ricoh Co., Ltd. (3) Printing conditions: recording density is 300 × 600 dpi, printing area is 526.3 cm ² / A4 size, and ink discharge adhesion amount is 5.6 g / m ²
(4) Evaluation environment: 23 ° C. ± 0.5 ° C., 50% ± 5% RH
(5) Measurement of curl amount: Immediately after printing (within 10 seconds after ejection from the printing device) and after standing for 1 day, place the curl height gently on a flat desk with the curl side up, for A4 size recording The heights of the four corners of the media were measured on a JIS class 1 scale, and the four-point measurement values were averaged. Moreover, when the curl was too large and became a cylinder, the diameter was measured.
〔Evaluation criteria〕
◎: Less than 10 mm ○: 10 mm or more and less than 40 mm △: 40 mm or more

Next, the following recording papers (1) to (5) were subjected to image quality evaluation in the following manner using the recording ink (black) of Reference Example 3.

-Recording paper (1)-
Commercially available paper (trade name; aurora coat, basis weight = 104.7 g / m ² , manufactured by Nippon Paper Industries Co., Ltd.)
-Recording paper (2)-
Oji Paper Co., Ltd., POD gloss coat, basis weight = 100 g / m ²
-Recording paper (3)-
Nippon Paper Industries Co., Ltd., space DX (gravure paper), basis weight = 56.5 g / m ²
-Recording paper (4)-
Commercially available matte coated paper for inkjet (trade name; Superfine exclusive paper, manufactured by Seiko Epson Corporation)
-Recording paper (5)-
Transparent polyester film (trade name: Lumirror U10, thickness 100 μm, manufactured by TORAY)

For the recording papers (1) to (5), the amount of pure water transferred was measured as follows. The results are shown in Table 8.
<Measurement of the amount of pure water transferred by dynamic scanning absorption meter>
About the recording papers (1) to (5), the absorption curve of pure water was measured using a dynamic scanning absorption meter (model: KS350D, manufactured by Kyowa Seiko Co., Ltd.). The absorption curve was plotted with a transition amount (mL / m ² ) and a square root of contact time √ (ms) to make a straight line with a certain slope, and the value of the transition amount after a certain time was measured by interpolation.

<Evaluation>
Using the recording ink (black) of Reference Example 3, an inkjet recording apparatus (IPSiO GXe-5500, manufactured by Ricoh Co., Ltd.) was used to print 5% of the area of A4 size paper of recording papers (1) to (5) with a black solid color. A chart to be filled with an image is printed on each recording sheet for each evaluation, and the black solid image output after that is printed as follows: image quality (beading, spur stain, glossiness), and dryness Evaluation was conducted. The results are shown in Table 9.

-Beading-
The degree of beading (density unevenness) of the obtained black solid part was visually evaluated. The rank evaluation was performed using a five-stage sample (rank 1: defective to rank 5: good).

-Spur dirt-
The degree of offset contamination due to spurs from the obtained black solid portion to the background portion was visually evaluated according to the following criteria.
〔Evaluation criteria〕
Rank 1: Spur offset dirt is clearly visible Rank 2: Spur offset dirt is slightly visible Rank 3: Spur offset dirt appears faint, but there is no practical problem Rank 4: Spur offset dirt is hardly recognized by the naked eye Rank 5: Spur offset dirt No dirt at all

-Glossiness-
The glossiness of the obtained black solid part at an incident angle of 60 degrees was measured using a glossiness meter (manufactured by BYK Gardener, 4501).

-Dryness-
After 60 seconds from the discharge of the print, the filter paper was pressed against the black solid portion, and the degree of transfer stain on the filter paper was visually observed and judged according to the following criteria.
〔Evaluation criteria〕
○: No transfer stain △: Slight transfer stain ×: Transfer stain

* Glossiness cannot be measured because it does not dry.

The recording ink of the present invention can reduce the curl amount of plain paper immediately after printing, is excellent in image quality and high-speed printing on plain paper, has good ejection stability, and is excellent in drying on general-purpose printing paper. Image recording is possible, and it can be suitably used for an ink cartridge, an ink record, an ink jet recording apparatus, and an ink jet recording method.
Furthermore, a general-purpose printing paper (having a support and a coating layer coated on at least one surface of the support, and the transfer amount of pure water at a contact time of 100 ms measured by a dynamic scanning absorption meter. low recording media but is ^{1mL / m 2 ~10mL / m 2} , and the transfer amount of the recording medium of pure water at a contact time of 400ms is a ink absorption such that ^3mL / ^{m 2 ~25mL} / m 2 ) Can be used to form a high-quality image.
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.

DESCRIPTION OF SYMBOLS 1 Paper feed tray 2 Pressure plate 3 Recording paper 4 Paper feed rotary body 5 Base 6 Pressure plate spring 7 Transport roller 8 Transport guide 9 Transport guide 10 Platen 11 Pinch roller 12 Paper feed rotary body for manual paper feed 13 Manual tray 14 Line head 101 Main body 102 Paper feed tray 103 Paper discharge tray 104 Ink cartridge loading part 111 Upper cover 112 Front face 115 Front cover 131 Guide rod 132 Stay 133 Carriage 134 Recording head 135 Sub tank 141 Paper placement part 142 Paper 144 Separation pad 151 Conveying belt 152 Again Counter roller 156 Charging roller 157 Conveying roller 158 Dense roller 171 Separation claw 172 Paper discharge roller 173 Paper discharge roller 181 Double-sided paper feed unit 201 Ink cartridge 241 Ink bag 2 2 ink injection port 243 ink discharge port 244 cartridge exterior A image recording apparatus a rotating shaft

JP 2004-136458 A JP 2008-18711 A JP 2009-52018 A JP 2009-287014 A

Claims (15)

Has a coating layer on at least one of on the surface of the support, by a dynamic scanning liquid absorption amount of transfer of the recording medium of pure water at the contacting time 100ms measured by meter 1mL / m ² ~10mL / m ² There, and an ink jet recording method for transfer amount of the recording medium of pure water at a contact time of 400ms confer recording ink to the recording medium is ^{3mL / m 2 ~25mL / m 2} ,
Including at least an ink flying step of applying a stimulus to the recording ink and causing the recording ink to fly to record an image on the recording medium;
The recording ink is a recording ink for medium penetration containing at least water, a water-soluble organic solvent, and a colorant,
As the water-soluble organic solvent, one or more polyhydric alcohols having an equilibrium water content of 30% by mass or more at a temperature of 23 ° C. and a humidity of 80% RH, and at least one of amide compounds represented by the following general formula (I) An ink jet recording method comprising: a seed.
However, in said general formula (I), R < ₁ > and R < ₂ > all show a methyl group, R < ₃ > shows a C4-C6 alkyl group. The ink jet recording method according to claim 1, wherein the water-soluble organic solvent contains at least one amide compound represented by the following general formula (I) and an amide compound represented by the following structural formula (i). .
However, in said general formula (I), R < ₁ > and R < ₂ > all show a methyl group, R < ₃ > shows a C4-C6 alkyl group.
The inkjet recording method according to claim 1, wherein the amide compound represented by the general formula (I) is an amide compound represented by any one of the following structural formulas (ii) and (iii). .
  4. The water-soluble organic solvent according to claim 1, wherein the water-soluble organic solvent contains at least one alkylalkanediol having a main chain of alkanediol having 3 to 5 carbon atoms and a branched chain of alkyl having 1 to 2 carbon atoms. The inkjet recording method as described.   5. The alkylalkanediol is at least one selected from 2-methyl-1,3-propanediol, 3-methyl-1,3-butanediol and 3-methyl-1,5-pentanediol. The ink jet recording method described in 1.   The ink jet recording method according to claim 1, wherein the polyhydric alcohol is at least one of glycerin and 1,3-butanediol. The inkjet recording method according to any one of claims 1 to 6, wherein the content of the water-soluble organic solvent is 20% by mass to 80% by mass .   Pigment containing pigment dispersion, pigment, pigment dispersant, and polymer dispersion stabilizer that has at least one hydrophilic group on the surface and exhibits water dispersibility in the absence of dispersant The ink jet recording method according to any one of claims 1 to 7, comprising any one of a dispersion and an aqueous dispersion of water-insoluble vinyl polymer particles containing a pigment.   The ink jet recording method according to claim 1, wherein the recording ink for penetrating the medium further contains a surfactant.   The ink jet recording method according to any one of claims 1 to 9, wherein the recording ink for penetrating the medium further contains a penetrating agent, and the penetrating agent contains at least one kind of a polyol compound having 8 to 11 carbon atoms. .   The inkjet recording method according to claim 10, wherein the polyol compound having 8 to 11 carbon atoms is any one of 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol. .   The inkjet recording method according to claim 1, wherein the recording ink for penetrating the medium has a viscosity at 25 ° C. of 5 mPa · s to 25 mPa · s.   The inkjet recording method according to claim 1, wherein the recording ink for penetrating the medium is at least one selected from cyan ink, magenta ink, yellow ink, and black ink. The coating layer is provided on at least one surface of the support, and the transfer amount of pure water to the recording medium at a contact time of 100 ms measured by a dynamic scanning absorption meter is 1 mL / m ² -10mL / m ² And the transfer amount of pure water to a recording medium at a contact time of 400 ms is 3 mL / m. ² ~ 25mL / m ² A recording medium, and
A recording ink for media penetration containing at least water, a water-soluble organic solvent, and a colorant;
Have
As the water-soluble organic solvent, one or more polyhydric alcohols having an equilibrium water content of 30% by mass or more at a temperature of 23 ° C. and a humidity of 80% RH, and at least one of amide compounds represented by the following general formula (I) A recording set comprising a seed.
However, in the general formula (I), R ₁ And R ₂ Each represents a methyl group, R ₃ Represents an alkyl group having 4 to 6 carbon atoms. The coating layer is provided on at least one surface of the support, and the transfer amount of pure water to the recording medium at a contact time of 100 ms measured by a dynamic scanning absorption meter is 1 mL / m ² -10mL / m ² And the transfer amount of pure water to a recording medium at a contact time of 400 ms is 3 mL / m. ² ~ 25mL / m ² An inkjet recording method for applying a recording ink to a recording medium,
An ink flying step of applying a stimulus to the recording ink, causing the recording ink to fly, and recording an image on the recording medium;
At least the step of contacting the image and the spur,
The recording ink is a recording ink for medium penetration containing at least water, a water-soluble organic solvent, and a colorant,
As the water-soluble organic solvent, one or more polyhydric alcohols having an equilibrium water content of 30% by mass or more at a temperature of 23 ° C. and a humidity of 80% RH, and at least one of amide compounds represented by the following general formula (I) An ink jet recording method comprising: a seed.
However, in the general formula (I), R ₁ And R ₂ Each represents a methyl group, R ₃ Represents an alkyl group having 4 to 6 carbon atoms.