JP6848740B2 - Ink, ink container, image recording device, image recording method, and recorded material - Google Patents

Description

The present invention relates to ink, an ink container, an image recording device, an image recording method, and a recorded material.

Those with metallic luster give people a glittering impression, so they are often seen in every aspect of daily life. In some cases, the metal itself is used to impart the design property, but in many cases, the base material is coated with a coloring composition having a metallic luster to impart the design property.
As the coating method, a method of printing by various printing methods using a printing ink containing a brilliant pigment, and a method of transferring foil by adhesive or heat fusion have been used.

Among the metallic lusters, gold is a symbol of wealth and has been loved by people since ancient times, and is an indispensable color for happy New Year and other events. On the other hand, silver is also very popular due to its calm texture, and is often seen in various situations. In addition, unlike gold, silver can express various metallic luster colors including gold by mixing with coloring compositions of other colors, so that it is more versatile than gold and has industrial utility value. high.

Conventionally, aluminum fine particles are widely used as a pigment used in a coloring composition having a silvery metallic luster.
Further, with the development of inkjet printing technology, there is an increasing demand for obtaining printed matter having metallic luster even in inkjet printing. For example, an inkjet ink containing a commercially available scaly aluminum pigment, a titanium oxide-coated mica pigment, or the like as a bright pigment has been proposed (see, for example, Patent Document 1).

Further, a printing method has been proposed in which a printed matter having high glossiness can be obtained by printing an ink composition containing a metal colloid on the surface of a porous printed matter (see, for example, Patent Document 2).

An object of the present invention is to provide an ink having excellent storage stability and ejection stability.

The ink of the present invention as a means for solving the above-mentioned problems contains silver, water, and an amine compound, the amine compound has _two NH groups and an OH group, and the amine compound has the NH. _{The number X of the two} groups and the number Y of the OH groups satisfy the following formulas (1) and (2).
3 ≤ X + Y ... Equation (1)
X ≤ Y ... Equation (2)

According to the present invention, it is possible to provide an ink having excellent storage stability and ejection stability.

It is a figure which shows an example of the recording apparatus which uses the ink of this invention. It is a perspective view of the main tank which holds the ink of this invention.

(ink)
The ink of the present invention contains silver, water, and an amine compound, and the amine compound has _two NH groups and an OH group, and the number X of the _{two NH groups contained in the amine compound and the OH group.} The number Y of is an ink satisfying the following formula (1) and the following formula (2).
3 ≤ X + Y ... Equation (1)
X ≤ Y ... Equation (2)
Further, if necessary, an organic solvent, a resin, a surfactant, a defoaming agent, an antiseptic / antifungal agent, a rust preventive, a pH adjuster and the like may be added.
The ink of the present invention is derived from the fact that the specific gravity of metal colloids such as silver is heavier than that of organic pigments in conventional inks, and the metal colloids tend to settle. This is based on the finding that storage stability is lost, nozzle omission occurs, and there is a problem with ejection stability.
Further, it is based on the finding that the coating film becomes non-uniform due to the unstable discharge, the metallic luster and the mirror surface (mapping property) are lost, and the color becomes unnatural silver.

Hereinafter, silver, water, amine compounds, resins, additives and the like used in the ink of the present invention will be described.

<Silver>
The silver can impart an excellent metallic luster to the obtained image. Further, the silver is a metal having a high whiteness among various metals, and various metal colors can be realized by combining with inks of other colors. Further, the silver is stable in water because of its weak reactivity with water. As a result, it is possible to develop a water-based bright ink that can reduce the environmental load. It is preferable to use silver particles as the silver.

Examples of conventional bright pigments include pearl pigments and metal particles. Typical examples of the pearl pigment include titanium dioxide-coated mica, fish scale thin, and pigments having pearl luster and interference luster such as acidified bismuth. However, the particle size of these pigments is on the order of microns, and the ejection by the inkjet head is limited, which is not preferable. Further, if the particle size is reduced to improve the inkjet ejection property, the ejection property is secured to some extent, but there is a problem that the gloss due to interference is not exhibited in principle because the particle size is too small. On the other hand, typical examples of the metal particles include particles of aluminum, chromium, indium, copper, gold, silver and the like. Among these, aluminum, gold, and silver are preferably used because of their weak toxicity. However, the aluminum tends to react with water to form an oxide and whiten over time. Further, the gold is not preferable because it is expensive and there is a limitation in adjusting the color. Further, since all of the metal particles have a heavier specific gravity than that of an organic pigment, there is a problem that the metal particles tend to settle when the metal particles are dispersed to form an ink, and as a result, nozzle omission occurs. Further, since the ejection becomes unstable, there is a problem that the metallic luster and the mirror surface property (mapping property) are impaired because the metal particles do not uniformly adhere to the recording medium when printed on the recording medium.

The 50% cumulative volume particle diameter (D ₅₀ ) of the silver particles by the dynamic light scattering method is preferably 5 nm or more and 2,200 nm or less, and more preferably 5 nm or more and 2,053 nm or less. When the 50% cumulative volume particle size (D ₅₀ ) is 5 nm or more, even if an ink containing silver particles is applied to a recording medium having an ink receiving layer having pores, the ink receiving layer having porosity It is preferable because a large number of silver particles do not enter the mixture, and the color (yellow) as silver nanoparticles is reflected and the color does not become unnatural or does not develop metallic luster. Further, when the 50% cumulative volume particle diameter (D ₅₀ ) is 2,200 nm or less, silver particles do not settle over time and discharge becomes unstable, which is preferable.

The 90% cumulative volume particle diameter (D ₉₀ ) of the silver particles by the dynamic light scattering method is preferably 4,000 nm or less, more preferably 2,000 nm or less, and particularly preferably 1,890 nm or less. When the 90% cumulative volume particle diameter (D ₉₀ ) is 4,000 nm or less, the silver particles are sufficiently small with respect to the nozzle of the ink ejection head and can be ejected stably, which is preferable. When it is 000 nm or less, even if primary aggregation of silver particles occurs, it is less likely to affect ink ejection, which is more preferable from the viewpoint of continuous ejection stability.

The 50% cumulative volume particle size (D ₅₀ ) and the 90% cumulative volume particle size (D ₉₀ ) are obtained by measuring the diameter and the number of silver particles and statistically processing the results. From the diameter-addition curve, the diameter of the silver particles when it becomes 50% of the total volume is 50% cumulative volume particle size (D ₅₀ ), and the diameter of the silver particles when it becomes 90% of the total volume is 90% cumulative volume particles. It is a value as a diameter (D _90). The diameter of the silver particles may be the diameter of the silver particles themselves, or may be the diameter of the colloidal particles when the silver particles are dispersed in a colloidal form.

The diameter of the silver particles can be determined by using, for example, a particle size distribution measuring device based on a dynamic light scattering method if the silver particles are in a dispersed state in water. Examples of the particle size distribution measuring device by the dynamic light scattering method include Nanotrack Wave-UT151 (manufactured by Microtrack Bell Co., Ltd.), Nanotrack Wave-EX150 (manufactured by Nikkiso Co., Ltd.), ELSZ-2, and DLS-. Examples thereof include 8000 (manufactured by Otsuka Electronics Co., Ltd.) and LB-550 (manufactured by HORIBA, Ltd.).
In addition to these, measurement can be performed by electron microscopy. A photograph of silver particles is obtained by the electron microscope, and the diameter of the silver particles can be determined by performing image processing on the photograph and measuring the photograph. As an example, the area of 50 or more silver particles in a photograph is randomly obtained from a photograph, and the diameters of equivalent circles are calculated to obtain the particle size. Then, the particle size addition curve can be obtained from the obtained particle size.

<Manufacturing method of silver particles>
The method for producing the silver particles is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a pulverization method in which a coarse powder obtained by pulverizing an ingot or the like is pulverized to a desired particle size. A method of peeling a silver film formed on a film by a vapor phase film forming method such as vapor deposition and pulverizing the film (particularly, a method of peeling and pulverizing in a liquid and dispersing in the liquid), wet reduction. Examples include chemical granulation methods such as the method and various atomization methods.

Examples of the wet reduction method include a method in which aqueous ammonia is added to an aqueous solution of silver nitrate to form a silver ammine complex, and then a reducing agent such as formarin and hydrazine is added to reduce the amount to silver to obtain silver powder, or an aqueous solution of silver nitrate. After adding sodium hydroxide to silver nitrate particles, a reducing agent such as formalin or hydrazine is added to reduce the amount of silver oxide to silver to obtain silver powder. Then, if necessary, the solution containing the silver particles is solid-liquid separated to separate the silver particles as solids into a solution, and the silver powder is washed with an appropriate cleaning agent to remove the liquid adhering to the silver powder. Further, the silver powder is dried to remove water, and a treatment such as crushing or classification can be performed to obtain silver particles having a desired particle size.

The atomizing method is, for example, a method in which molten silver (molten metal) is collided with a coolant such as water or gas to be pulverized and produced. According to the atomizing method, silver particles having a uniform particle size can be obtained.

<Manufacturing method of silver particle dispersion>
In order to disperse the silver particles in water to obtain a silver particle dispersion liquid, a method of introducing a hydrophilic functional group into the surface of the silver particles to form a self-dispersive pigment, or a method of coating the surface of the silver particles with a resin and dispersing them. Examples thereof include a method of dispersing the mixture and a method of dispersing the mixture using a dispersant.

As a method of coating the surface of the silver particles with a resin and dispersing them, a method in which the silver particles are encapsulated in microcapsules and can be dispersed in water can be used. In this case, it is not necessary that all the silver particles blended in the ink are coated with the resin, and the uncoated silver particles or the partially coated silver particles are submerged in water as long as the effect of the present invention is not impaired. It may be dispersed.

Examples of the method of dispersing using the dispersant include a method of dispersing using a known low-molecular-weight dispersant and a high-molecular-weight dispersant represented by a surfactant.

Examples of the dispersant include anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, and the like, depending on the system of silver particles and the ink used. These may be used alone or in combination of two or more. Among these, anionic surfactants and nonionic surfactants having an HLB value of 10 or more and 20 or less are preferable.

Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, alkylbenzene sulfonate (for example, NH ₄ , Na, Ca, etc.) and alkyldiphenyl ether disulfonate (for example, NH ₄ , Na, Ca, etc.). , Dialkyl succinate sulfonic acid Na salt, Naphthalene sulfonic acid formarin condensate Na salt, Polyoxyethylene polycyclic phenyl ether sulfate ester salt (for example, NH ₄ , Na, etc.), Laurate, Polyoxyethylene alkyl ether sulfate salt, Examples include oleate. These may be used alone or in combination of two or more.
Among these, dioctyl sulfosuccinic acid Na salt, naphthalene sulfonic acid formalin condensate Na salt, and polyoxyethylene styrene phenyl ether sulfonic acid NH ₄ salt are preferable.

Examples of the nonionic surfactant having an HLB value of 10 or more and 20 or less include polyoxyethylene alkyl ether, polyoxyalkylene alkyl ether, polyoxyethylene polycyclic phenyl ether, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, and poly. Examples thereof include oxyethylene alkyl phenyl ether, polyoxyethylene alkyl amine, polyoxyethylene alkyl amide, and acetylene glycol. These may be used alone or in combination of two or more.
Among these, polyoxyethylene lauryl ether, polyoxyethylene-β-naphthyl ether, polyoxyethylene sorbitan monooleate, and polyoxyethylene styrene phenyl ether are preferable.

Examples of the polymer-type dispersant include α-olefin-maleic anhydride copolymer represented by the following general formula (A), styrene- (meth) acrylic copolymer, water-soluble polyurethane resin, and water-soluble. Examples include polyester resin. These may be used alone or in combination of two or more.

ただし、前記一般式（Ａ）中、Ｒは炭素数６以上３０以下、好ましくは１２以上２２以下、より好ましくは１８以上２２以下のアルキル基を表す。ｎは１以上の整数を表し、２０以上１００以下の整数が好ましい。

However, in the general formula (A), R represents an alkyl group having 6 or more and 30 or less carbon atoms, preferably 12 or more and 22 or less, and more preferably 18 or more and 22 or less. n represents an integer of 1 or more, and an integer of 20 or more and 100 or less is preferable.

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

The weight average molecular weight of the α-olefin-maleic anhydride copolymer represented by the general formula (A) is not particularly limited and may be appropriately selected depending on the intended purpose. It is preferably 000 or less. The weight average molecular weight can be measured using, for example, gel permeation chromatography (GPC).

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 cold water. It is almost insoluble in. However, when used by dissolving in an alkaline solution or an alkaline aqueous solution having an acid value equal to or more than the acid value of the copolymer and the resin (preferably 1.0 times or more and 1.5 times or less the acid value), the dispersant is used. Can exert the effect of. Further, in order to dissolve the copolymer and the resin in an alkaline solution or an alkaline aqueous solution, the copolymer and the resin can be easily dissolved by heating and stirring. If 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, it can be used as a dispersion stabilizer. The effect of is not impaired.

Examples of the base in the alkaline solution or alkaline aqueous solution include hydroxides of alkali metals such as sodium hydroxide, potassium hydroxide and lithium hydroxide; basic substances such as ammonia, triethylamine and morpholine; triethanolamine and diethanolamine. Examples thereof include alcohol amines such as N-methyldiethanolamine, 2-amino-2-ethyl-1,3-propanediol, and choline. These may be used alone or in combination of two or more.

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

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

As the water-soluble polyurethane resin, a synthetic one may be used, or a commercially available product may be used.
Examples of the commercially available product include Takerack W-5025, Takerak W-6010, and Takerak W-5661 (all manufactured by Mitsui Takeda Chemical Co., Ltd.).

As the water-soluble polyester resin, a synthetic resin may be used, or a commercially available product may be used.
Examples of the commercially available products include Nichigopolyester W-0030, Nichigopolyester W-0005S30WO, Nichigopolyester WR-961 (all manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), Pesresin A-210, and Pesresin A-520 (above, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.). As mentioned above, (manufactured by Takamatsu Oil & Fat Co., Ltd.) and the like.

The acid value of the polymer-type dispersant is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 40 mgKOH / g or more and 400 mgKOH / g or less, and 60 mgKOH / g or more and 350 mgKOH / g or less. More preferred. When the acid value is 40 mgKOH / g or more, the solubility of the alkaline solution can be increased, and when it is 400 mgKOH / g or less, the viscosity of the dispersion can be suppressed and the increase in ink viscosity can be suppressed. Therefore, the discharge can be kept good, and the dispersion stability of the dispersion can be kept high.

The weight average molecular weight of the polymer-type dispersant is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 20,000 or less, and more preferably 5,000 or more and 20,000 or less. When the weight average molecular weight is 20,000 or less, the solubility of the alkaline solution can be increased, and since the viscosity is low, the dispersion viscosity can be lowered. When the weight average molecular weight is 5,000 or more, the pigment dispersion can be dispersed. Stability can be further improved. The weight average molecular weight can be measured using, for example, gel permeation chromatography (GPC).

As the dispersant, one type may be used alone, two or more types may be used in combination, or a plurality of types of a high molecular weight dispersant and a low molecular weight dispersant may be used in combination. By using the plurality of types of dispersants in combination, it is possible to create a dispersion that makes the best use of the characteristics of the dispersants, and it is possible to improve the dispersibility of silver particles and the stability over time.

The content of the dispersant is preferably 1 part by mass or more and 100 parts by mass or less, and more preferably 10 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of silver particles. When the content is 1 part by mass or more, silver particles can be dispersed, and depending on the dispersion conditions, even primary particles can be dispersed. Further, when the content is 100 parts by mass or less, there are not many excess components adsorbed on the silver particles, which does not affect the physical characteristics of the ink. Therefore, it is possible to suppress image bleeding, deterioration of water resistance and abrasion resistance, deterioration of ejection property from the nozzle, and deterioration of economic efficiency.

As the silver particle dispersion, water, silver particles, a dispersant, and if necessary, other components are dispersed together. For the dispersion, it is preferable to use a disperser, and after dissolving the dispersant in water and then adding the silver particles to sufficiently moisten the dispersion, high-speed stirring with a homogenizer, a ball such as a bead mill or a ball mill is used. A silver particle dispersion can be produced by dispersing by a method using the disperser used, a kneading disperser using a shearing force such as a roll mill, an ultrasonic disperser, or the like.

In order to observe the state of the silver particles, observation with a transmission electron microscope or a scanning electron microscope (SEM) is effective. Further, in order to confirm the silver particles, it is effective to embed the pigment in a resin and cut it to obtain a cross section and observe it. To grasp the dispersed state of the silver particle dispersion, to observe individual particles, the dispersion is frozen using the freeze replica method at the time of preparing the observation sample, and the split surface is fixed by vapor deposition or the like. It is possible to confirm the state of dispersion of silver particles.

The composition of the silver particles can be macroscopically analyzed by fluorescent X-ray analysis, and the composition can be analyzed even for minute parts by an electron probe microanalyzer (EPMA). Furthermore, by using energy dispersive X-ray spectroscopy (EDX) in combination with SEM, the composition of each silver particle can be grasped.
In addition to these, it is possible to grasp the elemental analysis of the outermost layer of the composition and the chemical state of the element by X-ray photoelectron spectroscopy (XPS), and it is possible to grasp the detailed film state. Further, by performing surface etching by a sputtering method, a three-dimensional composition distribution can be grasped.

The content of silver particles in the silver particle dispersion is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of obtaining good dispersibility and increasing the degree of freedom in ink formulation, 1 It is preferably mass% or more and 50 mass% or less, more preferably 1 mass% or more and 30 mass% or less, and particularly preferably 1 mass% or more and 15 mass% or less. When the content of the silver particles is 1% by mass or more, the silver particle concentration can be adjusted as an ink formulation. Further, when the content is 50% by mass or less, the viscosity of the dispersion liquid can be lowered, so that the handling when producing the ink becomes easy. Further, when the content is 30% by mass or less, it is easy to stir during the production of the dispersion liquid, and the dispersion efficiency can be further improved.
If necessary, the silver particle dispersion liquid preferably has coarse particles removed by a filter, a centrifuge, or the like.

<Manufacturing method of silver particle dispersion liquid dispersed as silver colloid>
The silver particles are preferably dispersed in an aqueous dispersion medium as a silver colloid having a protective colloid attached to the surface thereof. As a result, the dispersibility of the silver particles in the aqueous dispersion medium becomes particularly excellent, and the storage stability of the ink can be remarkably improved. The silver colloid may be prepared by any method. For example, it is obtained by preparing a solution containing silver ions and reducing the silver ions with a reducing agent in the presence of a protective colloid. (See, for example, Japanese Patent Application Laid-Open No. 2006-299329). When producing a metal colloid by these methods, if a surfactant or the like is added to the aqueous solution at any time before and after the reduction reaction, the dispersion stability of the metal particles can be further improved.
The particle size of the silver particles can be controlled by controlling the reduction reaction with the reducing agent. That is, it can be controlled by adjusting the addition rate of the reducing agent and the reaction temperature. For example, the particle size can be adjusted to a smaller size by slowing the addition rate of the reducing agent or lowering the liquid temperature. Is.

The protective colloid is not particularly limited as long as it is an organic substance that protects the surface of silver particles, but an organic compound having a carboxyl group and a dispersant polymer are preferable, and either of them may be used alone or in combination. Although it may be used in combination, it is more preferable because it has a synergistic effect.

-Organic compounds with carboxyl groups-
The number of carboxyl groups in the organic compound having a carboxyl group is not particularly limited as long as it is 1 or more per molecule, and can be appropriately selected depending on the intended purpose. For example, 1 to 10 is preferable, and 1 to 1 is preferable. 5 is more preferable, and 1 to 3 are particularly preferable.

In the organic compound having a carboxyl group, some or all of the carboxyl groups may form a salt (for example, a salt with an amine, a metal salt, etc.). In particular, in the present invention, the carboxyl groups (particularly all carboxyl groups) do not form salts [particularly salts with basic compounds (such as salts with amines or amine salts)) organic compounds (ie, free). An organic compound having a carboxyl group) can be preferably used.

The organic compound having a carboxyl group is not particularly limited as long as it has a carboxyl group, and can be appropriately selected depending on the intended purpose. It may have a positional group, etc.).
Examples of the functional group (or coordinating group) other than the carboxyl group include a group (or functional group) having at least one heteroatom selected from a halogen atom, a nitrogen atom, an oxygen atom, and a sulfur atom. ) Or the group (ammonium base, etc.) that formed these salts. These functional groups may be contained in an organic compound having a carboxyl group, either alone or in combination of two or more.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like.
Examples of the group having a nitrogen atom include an amino group, a substituted amino group (dialkylamino group and the like), an imino group (-NH-), a nitrogen ring group (a 5- to 8-membered nitrogen ring group such as a pyridyl group, and a carbazole group). , Morphorinyl group, etc.), amide group (-CON <), cyano group, nitro group and the like.
Examples of the group having an oxygen atom include a hydroxyl group, an alkoxy group (for example, a C1-6 alkoxy group such as a methoxy group, an ethoxy group, a propoxy group and a butoxy group), a formyl group and a carbonyl group (-CO-). Examples thereof include an ester group (-COO-) and an oxygen ring group (5- to 8-membered oxygen ring group such as a tetrahydropyranyl group).
Examples of the group having a sulfur atom include a thio group, a thiol group, a thiocarbonyl group (-SO-), an alkylthio group (an alkylthio group having 1 to 4 carbon atoms such as a methylthio group and an ethylthio group), a sulfo group, and the like. Examples thereof include a sulfamoyl group and a sulfinyl group (-SO _2- ).

Among these functional groups, the organic compound having a carboxyl group does not have a basic group capable of forming a salt with the carboxyl group (particularly, an amino group, a substituted amino group, an imino group, an ammonium base, etc.). It is preferably a compound.

A typical organic compound having a carboxyl group includes a carboxylic acid. Examples of such a carboxylic acid include monocarboxylic acid, polycarboxylic acid, hydroxycarboxylic acid (or oxycarboxylic acid) and the like.

Examples of the monocarboxylic acid include saturated aliphatic monocarboxylic acids, unsaturated aliphatic monocarboxylic acids, and aromatic monocarboxylic acids.
Examples of the saturated aliphatic monocarboxylic acid include carbons such as acetic acid, propionic acid, butyric acid, capric acid, caproic acid, caproic acid, caproic acid, lauric acid, myristic acid, cyclohexanecarboxylic acid, dehydrocholic acid, and colanic acid. Examples thereof include an aliphatic monocarboxylic acid having a number of 1 to 34 (preferably an aliphatic monocarboxylic acid having 1 to 30 carbon atoms).
Examples of the unsaturated aliphatic monocarboxylic acid include unsaturated aliphatic monocarboxylic acids having 4 or more and 34 or less carbon atoms (preferably 10 or less and 30 or more carbon atoms) such as oleic acid, erucic acid, linoleic acid, and avietic acid. (Unsaturated aliphatic monocarboxylic acid) and the like.
Examples of the aromatic monocarboxylic acid include aromatic monocarboxylic acids having 7 or more and 12 or less carbon atoms such as benzoic acid and naphthoic acid.

Examples of the polycarboxylic acid include aliphatic saturated polycarboxylic acids, aliphatic unsaturated polycarboxylic acids, and aromatic polycarboxylic acids.
Examples of the aliphatic saturated polycarboxylic acid include aliphatic saturated polycarboxylic acids having 2 to 14 carbon atoms such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, and cyclohexanedicarboxylic acid. Examples thereof include an acid (preferably an aliphatic saturated polycarboxylic acid having 2 or more and 10 or less carbon atoms).
Examples of the aliphatic unsaturated polycarboxylic acid include maleic acid, fumaric acid, itaconic acid, sorbic acid, tetrahydrophthalic acid and other aliphatic unsaturated polycarboxylic acids having 4 to 14 carbon atoms (preferably 4 carbon atoms). More than 10 or less aliphatic unsaturated polycarboxylic acids, etc.) and the like.
Examples of the aromatic polycarboxylic acid include aromatic polycarboxylic acids having 8 to 12 carbon atoms such as phthalic acid and trimellitic acid.

Examples of the hydroxycarboxylic acid include hydroxymonocarboxylic acid and hydroxypolycarboxylic acid.
Examples of the hydroxymonocarboxylic acid include aliphatic hydroxymonocarboxylic acid and aromatic hydroxymonocarboxylic acid.
Examples of the aliphatic hydroxymonocarboxylic acid include glycolic acid, lactic acid, oxybutyric acid, glyceric acid, 6-hydroxyhexanoic acid, cholic acid, deoxycholic acid, chenodeoxycholic acid, 12-oxokenodeoxycholic acid, glycocholic acid, and lithocol. An aliphatic hydroxymonocarboxylic acid having 2 or more and 50 or less carbon atoms (preferably an aliphatic hydroxymonocarboxylic acid having 2 or more and 34 or less carbon atoms, such as acid, hyodeoxycholic acid, ursodeoxycholic acid, apocholic acid, and taurocholic acid, and further An aliphatic hydroxymonocarboxylic acid having 2 or more and 30 or less carbon atoms is preferable.
Examples of the aromatic hydroxymonocarboxylic acid include salicylic acid, oxybenzoic acid, gallic acid and other aromatic hydroxymonocarboxylic acids having 7 to 12 carbon atoms.
Examples of the hydroxypolycarboxylic acid include aliphatic hydroxypolycarboxylic acids.
Examples of the aliphatic hydroxypolycarboxylic acid include aliphatic hydroxypolycarboxylic acids having 2 or more and 10 or less carbon atoms such as tartronic acid, tartaric acid, citric acid, and malic acid.

The carboxylic acid may form a salt, or may be an anhydride, a hydrate, or the like. Here, the carboxylic acid often does not form a salt (particularly, a salt with a basic compound such as a salt with an amine) as described above.

The organic compound having a carboxyl group may be used alone or in combination of two or more.
As the organic compound having a carboxyl group, a hydroxycarboxylic acid such as an aliphatic hydroxycarboxylic acid (aliphatic hydroxymonocarboxylic acid and an aliphatic hydroxypolycarboxylic acid) is preferable.
As the aliphatic hydroxycarboxylic acid, an alicyclic hydroxycarboxylic acid (or a hydroxycarboxylic acid having an alicyclic skeleton is preferable.
As the hydroxycarboxylic acid having an alicyclic hydroxycarboxylic acid (or an alicyclic skeleton), for example, an alicyclic hydroxycarboxylic acid having 6 or more and 34 or less carbon atoms such as coric acid is preferable, and 10 or more and 34 or less carbon atoms are preferable. The alicyclic hydroxycarboxylic acid is more preferable, and the alicyclic hydroxycarboxylic acid having 16 or more and 30 or less carbon atoms is particularly preferable.

Further, the polycyclic aliphatic hydroxycarboxylic acid such as cholic acid, the polycyclic aliphatic carboxylic acid such as dehydrocholic acid and cholic acid have a bulky structure and suppress the aggregation of silver particles. It is preferable because it has a large effect.
The polycyclic aliphatic hydroxycarboxylic acid is, for example, a condensed polycyclic aliphatic hydroxycarboxylic acid, preferably a condensed polycyclic aliphatic hydroxycarboxylic acid having 10 or more and 34 or less carbon atoms, and more preferably 14 or more carbon atoms. Condensed polycyclic aliphatic hydroxycarboxylic acid of 34 or less, particularly preferably condensed polycyclic aliphatic hydroxycarboxylic acid having 18 or more and 30 or less carbon atoms can be mentioned.
The polycyclic aliphatic carboxylic acid is, for example, a condensed polycyclic aliphatic carboxylic acid, preferably a condensed polycyclic aliphatic carboxylic acid having 10 or more and 34 or less carbon atoms, and more preferably 14 or more and 34 or less carbon atoms. Condensed polycyclic aliphatic hydroxycarboxylic acid, particularly preferably condensed polycyclic aliphatic carboxylic acid having 18 or more and 30 or less carbon atoms can be mentioned.

The number average molecular weight of the organic compound having a carboxyl group may be, for example, 1,000 or less, preferably 800 or less, and more preferably 600 or less. Further, the pKa value of the organic compound having a carboxyl group may be, for example, 1 or more, preferably 2 or more, and more preferably 2 or more and 8 or less. The number average molecular weight can be measured by, for example, gel permeation chromatography (GPC).

-Dispersant polymer-
In the present invention, the protective colloid is composed of the organic compound having a carboxyl group and the dispersant polymer in combination. By constructing the protective colloid in such a combination, a silver colloid containing silver particles having extremely few coarse particles can be obtained. In particular, in the present invention, the combination of the specific protective colloids makes it possible to increase the proportion of silver particles even though the number of coarse particles is small, and the storage stability of the silver colloid (or its dispersion) is also excellent.

The dispersant polymer (or polymer-type dispersant) is not particularly limited as long as it can coat silver particles, but an amphipathic dispersant polymer (or oligomer-type dispersant) can be preferably used.

Examples of the dispersant polymer include dispersant polymers usually used for dispersing colorants in the fields of paints and inks.
Examples of the dispersant polymer include styrene resin, acrylic resin, water-soluble urethane resin, water-soluble acrylic urethane resin, water-soluble epoxy resin, water-soluble polyester resin, cellulose derivative, polyvinyl alcohol, polyalkylene glycol, and natural materials. Examples thereof include polymers, polyethylene sulfonates, and formalin condensates of naphthalene sulfonic acid. These may be used alone or in combination of two or more.
Examples of the styrene-based resin include a styrene- (meth) acrylic acid copolymer, a styrene-maleic anhydride copolymer, and the like.
Examples of the acrylic resin include methyl (meth) acrylate- (meth) acrylic acid copolymer and the like.
Examples of the cellulose derivative include alkyl cellulose such as nitrocellulose and ethyl cellulose, alkyl-hydroxyalkyl cellulose such as ethyl hydroxyethyl cellulose, hydroxyalkyl cellulose such as hydroxyethyl cellulose and hydroxypropyl cellulose, and cellulose such as carboxyalkyl cellulose such as carboxymethyl cellulose. Examples include ethers.
Examples of the polyalkylene glycol include gelatin, dextrin and the like.
Examples of the polyalkylene glycol include liquid polyethylene glycol and polypropylene glycol.

As a typical dispersant polymer (amphipathic dispersant polymer), for example, a resin (or a water-soluble resin or a water-dispersible resin) containing a hydrophilic unit (or hydrophilic block) composed of a hydrophilic monomer). And so on.

Examples of the hydrophilic monomer include an addition polymerization type monomer such as a carboxyl group or acid anhydride group-containing monomer, a hydroxyl group-containing monomer, and a condensation type monomer such as an alkylene oxide (ethylene oxide or the like).
Examples of the acid anhydride group-containing monomer include (meth) acrylic monomers such as acrylic acid and methacrylic acid, unsaturated polyvalent carboxylic acids such as maleic acid, and maleic anhydride.
Examples of the hydroxyl group-containing monomer include hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and vinylphenol.
The condensation-based monomer may form a hydrophilic unit by reacting with an active group such as a hydroxyl group (for example, the hydroxyl group-containing monomer or the like).
As the hydrophilic monomer, one kind alone or two or more kinds may be combined to form a hydrophilic unit.

The dispersant polymer may contain at least a hydrophilic unit (or a hydrophilic block), and may be a hydrophilic monomer alone or a copolymer (for example, polyacrylic acid or a salt thereof). Like the above-exemplified styrene resin and acrylic resin, it may be a copolymer of a hydrophilic monomer and a hydrophobic monomer.

Examples of the hydrophobic monomer (nonionic monomer) include a (meth) acrylic monomer such as (meth) acrylic acid ester; a styrene monomer such as styrene, α-methylstyrene, and vinyltoluene, and α-carbon number 2. 20 or less olefin-based monomers, carboxylic acid vinyl ester-based monomers such as vinyl acetate and vinyl butyrate, and the like can be mentioned. The hydrophobic monomer may be used alone or in combination of two or more to form a hydrophobic unit.
Examples of the (meth) acrylic acid ester include methyl (meth) acrylic acid, ethyl (meth) acrylic acid, -n-butyl (meth) acrylic acid, -2-ethylhexyl (meth) acrylic acid, and (meth) acrylic. Lauryl acrylate, stearyl (meth) acrylate and the like (meth) acrylate having 1 or more and 20 or less carbon atoms, cycloalkyl (meth) acrylate such as cyclohexyl (meth) acrylate, phenyl (meth) acrylate and the like (meth) ) Aralyl (meth) acrylate such as aryl acrylate, benzyl (meth) acrylate, -2-phenylethyl (meth) acrylate and the like can be mentioned.
Examples of the olefin-based monomer having 2 or more and 20 or less α-carbons include ethylene, propylene, 1-butene, isobutylene, 1-hexene, 1-octene, 1-dodecene and the like.

When the dispersant polymer is a copolymer (for example, a copolymer of a hydrophilic monomer and a hydrophobic monomer), the copolymer is composed of a random copolymer, an alternating copolymer, and a block copolymer (for example, a hydrophilic monomer). It may be a copolymer composed of a hydrophilic block and a hydrophobic block composed of a hydrophobic monomer), a comb-type copolymer (or a comb-type graft copolymer), or the like.

The structure of the block copolymer is not particularly limited, and may be a diblock structure, a triblock structure (ABA type, BAB type), or the like.
Further, in the comb-shaped copolymer, the main chain may be composed of the hydrophilic block, the hydrophobic block, or the hydrophilic block and the hydrophobic block.

The hydrophilic unit may also be composed of a condensation block such as a hydrophilic block composed of alkylene oxide (ethylene oxide or the like) (polyalkylene oxide such as polyethylene oxide or polyethylene oxide-polypropylene oxide). ..

The hydrophilic block (polyalkylene oxide or the like) and the hydrophobic block (polyolefin block or the like) may be bonded via a linking group such as an ester bond, an amide bond, an ether bond, or a urethane bond.
The bond may be formed, for example, by modifying a hydrophobic block (polyolefin or the like) with a denaturing agent and then introducing a hydrophilic block.
Examples of the denaturing agent include unsaturated carboxylic acid or an anhydride thereof (such as (maleic anhydride) maleic acid), lactam or aminocarboxylic acid, hydroxylamine, and diamine.

Further, the polymer obtained from a monomer having a hydrophilic group such as a hydroxyl group or a carboxyl group (such as the hydroxyalkyl (meth) acrylate) is reacted (or bonded) with the hydrophilic monomer (ethylene oxide or the like) of the condensation system. Thereby, a comb-shaped copolymer (a comb-shaped copolymer in which the main chain is composed of a hydrophobic block) may be formed.

Further, the balance between hydrophilicity and hydrophobicity may be adjusted by using a hydrophilic nonionic monomer as the copolymerization component.
Examples of such a component include alkyleneoxy (particularly ethyleneoxy) units such as 2- (2-methoxyethoxy) ethyl (meth) acrylate and polyethylene glycol monomethacrylate (for example, number average molecular weight 200 to 1,000). Examples thereof include monomers or oligomers having.
Further, the balance between hydrophilicity and hydrophobicity may be adjusted by modifying (for example, esterifying) a hydrophilic group (carboxyl group or the like).

The dispersant polymer may have a functional group.
Examples of the functional group include an acid group (or an acidic group, for example, a carboxyl group (or an acid anhydride group), a sulfo group (sulfonic acid group), etc.), a hydroxyl group and the like. These functional groups may be contained in the dispersant polymer alone or in combination of two or more. Among these functional groups, it is preferable to have an acid group, and more preferably to have a carboxyl group.

When the dispersant polymer has an acid group (carboxyl group, etc.), at least a part or all of the acid group (carboxyl group, etc.) forms a salt (salt with amine, metal salt, etc.). However, in particular, in the present invention, the acid group such as a carboxyl group (particularly all carboxyl groups) is a salt [particularly, a salt with a basic compound (a salt with an amine or an amine salt, etc.)]. Dispersant polymers that do not form [ie, dispersant polymers with free acid groups (particularly carboxyl groups)] can be preferably used.

The acid value of the dispersant polymer having an acid group (particularly a carboxyl group) is, for example, preferably 1 mgKOH / g or more and 100 mgKOH / g or less, more preferably 3 mgKOH / g or more and 90 mgKOH / g or less, and 5 mgKOH / g or more and 80 mgKOH / g. It is more preferably g or less, and particularly preferably 7 mgKOH / g or more and 70 mgKOH / g or less. In the dispersant polymer having an acid group, the amine value may be 0 mgKOH / g (or approximately 0 mgKOH / g).

In the dispersant polymer, the position of the functional group as described above is not particularly limited, and may be a main chain, a side chain, or may be located in the main chain and the side chain. Good.
Such a functional group may be, for example, a hydrophilic monomer or a functional group derived from a hydrophilic unit (for example, a hydroxyl group), or a copolymerized monomer having a functional group (for example, maleic anhydride). It can also be introduced into the polymer by copolymerization. These may be used alone or in combination of two or more. As the dispersant polymer, the polymer dispersant (polymer pigment dispersant) described in JP-A-2004-207558 may be used.

As the dispersant polymer, a synthesized polymer may be used, or a commercially available product may be used. Examples of the commercially available dispersant polymer (or dispersant composed of at least an amphoteric dispersant) include sol sparse 13240, sol sparse 13940, sol sparse 32550, sol sparse 31845, sol sparse 24000, sol sparse 26000, sol sparse 27000, and sol sparse. Solsperse series such as 28000, Solsperse 41090 [manufactured by Abyssia]; Disparbic 160, Disparbic 161, Disparbic 162, Disparbic 163, Disparbic 164, Disparbic 166, Disparbic 170, Disparbic 180, Disparbic 182. , Disparbic 184, Disparbic 190, Disparbic 191, Disparbic 192, Disparbic 193, Disparbic 194, Disparbic 2001, Disparbic 2050, etc. Disparbic series [manufactured by BIC Chemie Co., Ltd.]; EFKA-46, EFKA- 47, EFKA-48, EFKA-49, EFKA-1501, EFKA-1502, EFKA-4540, EFKA-4550, Polymer 100, Polymer 120, Polymer 150, Polymer 400, Polymer 401, Polymer 402, Polymer 403, Polymer 450, Polymer 451, Polymer 452, Polymer 453 [manufactured by EFKA Chemical Co., Ltd.]; Ajispar series such as Ajispar PB711, Ajispar PAl11, Ajispar PB811, Ajispar PB821, Ajispar PW911 [Ajinomoto Co., Ltd.]; Floren DOPA-158, Floren DOPA- 22, Polymer DOPA-17, Polymer TG-700, Polymer TG-720W, Polymer-730W, Polymer-740W, Polymer-745W, etc. Polymer series [manufactured by Kyoeisha Chemical Co., Ltd.]; John Krill 678, John Krill 679, John Krill John Krill series such as 62 [manufactured by Johnson Polymer Co., Ltd.] and the like can be mentioned.
Among these, examples of the dispersant polymer having an acid group include Disperbic 190 and Disperbic 194.

The number average molecular weight of the dispersant polymer is preferably 1,500 or more and 100,000 or less, more preferably 2,000 or more and 80,000 or less, further preferably 3,000 or more and 50,000 or less, and 7,000 or more. 20,000 or less is particularly preferable. The number average molecular weight can be measured by, for example, gel permeation chromatography (GPC).

The content of silver in the ink is preferably 1% by mass or more as a lower limit value, more preferably 2.5% by mass or more, and more preferably 15% by mass or less as an upper limit value with respect to the total amount of ink. More preferably, it is 5% by mass or less, and particularly preferably 5% by mass or less. When the silver content is 1% by mass or more, the metallic luster and reproducibility of the obtained image are good, and when it is 15% by mass or less, the storage stability and ejection stability of the ink are improved. Can be done.

<Amine compound>
The amine compound used in the present invention _{has two} NH groups and an OH group, and _{the number X of the two} NH groups and the number Y of the OH groups of the amine compound are the following formulas (1) and the following formulas. There is no particular limitation as long as it is a compound satisfying (2).
3 ≤ X + Y ... Equation (1)
X ≤ Y ... Equation (2)
By containing the amine compound of the present invention, in the water-based ink of the present invention containing silver, the dispersibility of silver can be improved, and the storage stability and ejection stability of the ink can be improved.
The total number of the number of NH ₂ groups (X) and the number of OH groups (Y) is 3 or more as the lower limit value, preferably 10 or less as the upper limit value, and particularly preferably 4 or less.
It is preferable that the number of OH groups (Y) is larger than the number of NH _{2 groups (X).}

ただし、前記一般式（１）中、Ｒ^１は水素原子、メチル基、エチル基、又は−ＣＨ_２ＯＨを表し、ｎ１、及びｎ２は０〜１の整数を表す。 The amine compound is more preferably a compound represented by the following general formula (1), and the storage stability and ejection stability of the ink can be improved. In addition, excellent metallic luster and reproducibility can be obtained.
General formula (1)

However, in the general formula (1), R ¹ represents a hydrogen atom, a methyl group, an ethyl group, or −CH ₂ OH, and n1 and n2 represent an integer of 0 to 1.

The compound represented by the general formula (1) is not particularly limited and may be appropriately selected depending on the intended purpose. For example, 2-amino-2-methyl-1,3-propanediol and tri (hydroxy). Methyl) aminomethane, 2-amino-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol, 3-amino-1,2-propanediol and the like can be mentioned. These may be used alone or in combination of two or more.

The content of the amine compound is preferably 0.1% by mass or more and 5% by mass or less, and more preferably 0.1% by mass or more and 1% by mass or less with respect to the total amount of the ink.
When the content of the amine compound is 0.1% by mass or more and 5% by mass or less with respect to the total amount of the ink, the storage stability and ejection stability of the ink can be improved.

The molecular weight of the amine compound is preferably 300 or less, more preferably 200 or less, further preferably 150 or less, and particularly preferably 125 or less.
When the molecular weight of the amine compound is 300 or less, silver in the ink layer formed by applying ink to the recording medium can be sufficiently aggregated, and higher metallic luster and mapping property can be obtained. ..

The ratio (A / B) of the silver content (A) in the ink and the amine compound content (B) in the ink, which is represented by the following formula (3), is 1 or more and 50 or less. Is preferable, and 5 or more and 25 or less is more preferable. When the ratio (A / B) is 1 or more and 50 or less, the ratio of the silver and the amine compound in the ink becomes appropriate, and in particular, the storage stability and ejection stability of the ink can be improved.
1 ≤ A (mass%) / B (mass%) ≤ 50 ... Equation (3)

<Organic solvent>
The organic solvent used in the present invention is not particularly limited, and a water-soluble organic solvent can be used. Examples thereof include ethers such as polyhydric alcohols, polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines and sulfur-containing compounds.
Specific examples of the water-soluble organic solvent include ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, and 1,4-butane. Diol, 2,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol , 2,4-Pentanediol, 1,5-Pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, 1,5-hexanediol, Glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-hexanediol, ethyl-1,2,4-butanetriol, 1,2,3-butanetriol, 2,2,4-trimethyl- Polyhydric alcohols such as 1,3-pentanediol and petriol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl Polyhydric alcohol alkyl ethers such as ether, polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone. , 1,3-Dimethyl-2-imidazolidinone, ε-caprolactam, γ-butyrolactone and other nitrogen-containing heterocyclic compounds, formamide, N-methylformamide, N, N-dimethylformamide, 3-methoxy-N, N- Amidos such as dimethylpropionamide, 3-butoxy-N, N-dimethylpropionamide, amines such as monoethanolamine, diethanolamine and triethylamine, sulfur-containing compounds such as dimethylsulfoxide, sulfolane and thiodiethanol, propylene carbonate and ethylene carbonate. And so on.
It is preferable to use an organic solvent having a boiling point of 250 ° C. or lower because it not only functions as a wetting agent but also has good drying properties.

Polyol compounds having 8 or more carbon atoms and glycol ether compounds are also preferably used. Specific examples of the polyol compound having 8 or more carbon atoms include 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol.
Specific examples of glycol ether compounds include polyhydric alcohol alkyls such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether. Ethers: Polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether can be mentioned.

The polyol compound having 8 or more carbon atoms and the glycol ether compound can improve the permeability of the ink when paper is used as the recording medium.

The content of the organic solvent in the ink is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10% by mass or more and 60% by mass or less from the viewpoint of ink drying property and ejection reliability. More preferably, it is 20% by mass or more and 60% by mass or less.

<Water>
The content of water in the ink is not particularly limited and may be appropriately selected depending on the intended purpose, but from the viewpoint of ink drying property and ejection reliability, it is preferably 10% by mass or more and 90% by mass or less, and 20% by mass. % To 60% by mass is more preferable.

<Resin>
The type of resin contained in the ink is not particularly limited and may be appropriately selected depending on the intended purpose. For example, urethane resin, polyester resin, acrylic resin, vinyl acetate resin, styrene resin, butadiene resin, etc. Examples thereof include resins, styrene-butadiene resins, vinyl chloride resins, acrylic styrene resins, and acrylic silicone resins.
Resin particles made of these resins may be used. It is possible to obtain ink by mixing resin particles with a material such as a coloring material or an organic solvent in the state of a resin emulsion in which water is dispersed as a dispersion medium. As the resin particles, those synthesized as appropriate may be used, or commercially available products may be used. Further, these may be used alone or in combination of two or more kinds of resin particles.

The volume average particle diameter of the resin particles is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of obtaining good fixability and high image hardness, 10 nm or more and 1,000 nm or less are preferable. More than 200 nm is more preferable, and 10 nm or more and 100 nm or less is particularly preferable.
The volume average particle size can be measured using, for example, a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrack Bell Co., Ltd.).

The content of the resin is preferably 0.1% by mass or more and 9% by mass or less, and more preferably 1% by mass or more and 9% by mass or less with respect to the total amount of ink. When the content is 0.1% by mass or more and 9% by mass or less, the scratch resistance of the obtained image can be improved.

The particle size of the solid content in the ink is not particularly limited and can be appropriately selected according to the purpose, but from the viewpoint of improving image quality such as ejection stability and image density, the maximum frequency in terms of the maximum number of inks. Is preferably 20 nm or more and 1000 nm or less, and more preferably 20 nm or more and 150 nm or less. The solid content includes resin particles, pigment particles, and the like. The particle size can be measured using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrack Bell Co., Ltd.).

<Additives>
If necessary, a surfactant, a defoaming agent, an antiseptic / antifungal agent, a rust preventive, a pH adjuster, or the like may be added to the ink.

<Surfactant>
As the surfactant, any of a silicone-based surfactant, a fluorine-based surfactant, an amphoteric surfactant, a nonionic surfactant, and an anionic surfactant can be used.
The silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. Among them, those that do not decompose even at high pH are preferable, and examples thereof include side chain modified polydimethylsiloxane, double-ended modified polydimethylsiloxane, single-ended modified polydimethylsiloxane, and side chain double-ended modified polydimethylsiloxane. Those having an oxyethylene group and a polyoxyethylene polyoxypropylene group are particularly preferable because they exhibit good properties as an aqueous surfactant. Further, as the silicone-based surfactant, a polyether-modified silicone-based surfactant can also be used, and examples thereof include a compound in which a polyalkylene oxide structure is introduced into the Si portion side chain of dimethylsiloxane.
Examples of the fluorine-based surfactant 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. A polyoxyalkylene ether polymer compound is particularly preferable because it has a low foaming property.
Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid and perfluoroalkyl sulfonic acid salt. Examples of the perfluoroalkylcarboxylic acid compound include perfluoroalkylcarboxylic acid and perfluoroalkylcarboxylic acid salt. The polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain includes a sulfate ester salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain and a perfluoroalkyl ether group in the side chain. Examples thereof include salts of polyoxyalkylene ether polymers. The counterions of the salts in these fluorine-based surfactants are Li, Na, K, NH ₄ , NH ₃ CH ₂ CH ₂ OH, NH ₂ (CH ₂ CH ₂ OH) ₂ , NH (CH ₂ CH ₂ OH). ₃ etc. can be mentioned.
Examples of the amphoteric tenside agent include laurylaminopropionate, lauryldimethylbetaine, stearyldimethylbetaine, and lauryldihydroxyethylbetaine.
Examples of the nonionic surfactant include polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkyl amine, polyoxyethylene alkyl amide, polyoxyethylene propylene block polymer, sorbitan fatty acid ester, and polyoxyethylene sorbitan. Examples thereof include fatty acid esters and ethylene oxide adducts of acetylene alcohols.
Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, lauryl salt, and salt of polyoxyethylene alkyl ether sulfate.
These may be used alone or in combination of two or more.

（但し、一般式（Ｓ−１）式中、ｍ、ｎ、ａ、及びｂは、それぞれ独立に、整数を表わし、Ｒは、アルキレン基を表し、Ｒ’は、アルキル基を表す。）
上記のポリエーテル変性シリコーン系界面活性剤としては、市販品を用いることができ、例えば、ＫＦ−６１８、ＫＦ−６４２、ＫＦ−６４３（信越化学工業株式会社）、ＥＭＡＬＥＸ−ＳＳ−５６０２、ＳＳ−１９０６ＥＸ（日本エマルジョン株式会社）、ＦＺ−２１０５、ＦＺ−２１１８、ＦＺ−２１５４、ＦＺ−２１６１、ＦＺ−２１６２、ＦＺ−２１６３、ＦＺ−２１６４（東レ・ダウコーニング・シリコーン株式会社）、ＢＹＫ−３３、ＢＹＫ−３８７（ビックケミー株式会社）、ＴＳＦ４４４０、ＴＳＦ４４５２、ＴＳＦ４４５３（東芝シリコン株式会社）などが挙げられる。 The silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, side chain-modified polydimethylsiloxane, double-ended modified polydimethylsiloxane, one-ended modified polydimethylsiloxane, side. Examples thereof include polydimethylsiloxane modified at both ends of the chain, and a polyether-modified silicone-based surfactant having a polyoxyethylene group and a polyoxyethylene polyoxypropylene group as modifying groups exhibits good properties as an aqueous surfactant, and is particularly effective. preferable.
As such a surfactant, an appropriately synthesized one may be used, or a commercially available product may be used. As commercially available products, for example, they can be obtained from Big Chemie Co., Ltd., Shin-Etsu Chemical Co., Ltd., Toray Dow Corning Silicone Co., Ltd., Nippon Emulsion Co., Ltd., Kyoeisha Chemical Co., Ltd., and the like.
The above-mentioned polyether-modified silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the polyalkylene oxide structure represented by the general formula (S-1) is dimethylpoly. Examples thereof include those introduced into the Si part side chain of siloxane.
General formula (S-1)

(However, in the general formula (S-1), m, n, a, and b each independently represent an integer, R represents an alkylene group, and R'represents an alkyl group.)
Commercially available products can be used as the above-mentioned polyether-modified silicone-based surfactant, for example, KF-618, KF-642, KF-643 (Shinetsu Chemical Industry Co., Ltd.), EMALEX-SS-5602, SS- 1906EX (Nippon Emulsion Co., Ltd.), FZ-2105, FZ-2118, FZ-2154, FZ-2161, FZ-2162, FZ-2163, FZ-2164 (Toray Dow Corning Silicone Co., Ltd.), BYK-33, BYK-387 (Big Chemie Co., Ltd.), TSF4440, TSF4452, TSF4453 (Toshiba Silicon Co., Ltd.) and the like can be mentioned.

上記一般式（Ｆ−１）で表される化合物において、水溶性を付与するためにｍは０〜１０の整数が好ましく、ｎは０〜４０の整数が好ましい。
一般式（Ｆ−２）
Ｃ_ｎＦ_{２ｎ＋１−}ＣＨ_２ＣＨ（ＯＨ）ＣＨ_２−Ｏ−（ＣＨ_２ＣＨ_２Ｏ）_ａ−Ｙ
上記一般式（Ｆ−２）で表される化合物において、ＹはＨ、又はＣｍＦ_２ｍ＋１でｍは１〜６の整数、又はＣＨ_２ＣＨ（ＯＨ）ＣＨ_２−ＣｍＦ_２ｍ＋１でｍは４〜６の整数、又はＣｐＨ_２ｐ＋１でｐは１〜１９の整数である。ｎは１〜６の整数である。ａは４〜１４の整数である。
上記のフッ素系界面活性剤としては市販品を使用してもよい。この市販品としては、例えば、サーフロンＳ−１１１、Ｓ−１１２、Ｓ−１１３、Ｓ−１２１、Ｓ−１３１、Ｓ−１３２、Ｓ−１４１、Ｓ−１４５（いずれも、旭硝子株式会社製）；フルラードＦＣ−９３、ＦＣ−９５、ＦＣ−９８、ＦＣ−１２９、ＦＣ−１３５、ＦＣ−１７０Ｃ、ＦＣ−４３０、ＦＣ−４３１（いずれも、住友スリーエム株式会社製）；メガファックＦ−４７０、Ｆ−１４０５、Ｆ−４７４（いずれも、大日本インキ化学工業株式会社製）；ゾニール（Ｚｏｎｙｌ）ＴＢＳ、ＦＳＰ、ＦＳＡ、ＦＳＮ−１００、ＦＳＮ、ＦＳＯ−１００、ＦＳＯ、ＦＳ−３００、ＵＲ、キャプストーンＦＳ−３０、ＦＳ−３１、ＦＳ−３１００、ＦＳ−３４、ＦＳ−３５（いずれも、Ｃｈｅｍｏｕｒｓ社製）；ＦＴ−１１０、ＦＴ−２５０、ＦＴ−２５１、ＦＴ−４００Ｓ、ＦＴ−１５０、ＦＴ−４００ＳＷ（いずれも、株式会社ネオス社製）、ポリフォックスＰＦ−１３６Ａ，ＰＦ−１５６Ａ、ＰＦ−１５１Ｎ、ＰＦ−１５４、ＰＦ−１５９（オムノバ社製）、ユニダインＤＳＮ−４０３Ｎ（ダイキン工業株式会社製）などが挙げられ、これらの中でも、良好な印字品質、特に発色性、紙に対する浸透性、濡れ性、均染性が著しく向上する点から、Ｃｈｅｍｏｕｒｓ社製のＦＳ−３１００、ＦＳ−３４、ＦＳ−３００、株式会社ネオス製のＦＴ−１１０、ＦＴ−２５０、ＦＴ−２５１、ＦＴ−４００Ｓ、ＦＴ−１５０、ＦＴ−４００ＳＷ、オムノバ社製のポリフォックスＰＦ−１５１Ｎ及びダイキン工業株式会社製のユニダインＤＳＮ−４０３Ｎが特に好ましい。 As the fluorine-based surfactant, a compound having 2 to 16 carbon atoms substituted with fluorine is preferable, and a compound having 4 to 16 carbon atoms substituted with fluorine is more preferable.
Examples of the fluorine-based surfactant include a perfluoroalkyl phosphate ester compound, a perfluoroalkyl ethylene oxide adduct, and a polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain. Among these, a polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain is preferable because it has low foaming property, and is particularly a fluorine-based compound represented by the general formula (F-1) and the general formula (F-2). Surfactants are preferred.
General formula (F-1)

In the compound represented by the general formula (F-1), m is preferably an integer of 0 to 10, and n is preferably an integer of 0 to 40 in order to impart water solubility.
General formula (F-2)
C _n F _{2n + 1-} CH ₂ CH (OH) CH _2- O- (CH ₂ CH ₂ O) _a- Y
In the compound represented by the above general formula (F-2), Y is H or CmF _{2m + 1} and m is an integer of 1 to 6, or CH ₂ CH (OH) CH _2- CmF _{2m + 1} and m is 4 to 6. It is an integer, or CpH _{2p + 1} and p is an integer of 1-19. n is an integer of 1-6. a is an integer of 4 to 14.
Commercially available products may be used as the above-mentioned fluorine-based surfactant. Examples of this commercially available product 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.); Full Lard FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M Co., Ltd.); Megafuck F-470, F -1405, F-474 (all manufactured by Dainippon Ink and Chemicals Co., Ltd.); Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR, Capstone FS-30, FS-31, FS-3100, FS-34, FS-35 (all manufactured by The Chemours Company); FT-110, FT-250, FT-251, FT-400S, FT-150, FT- 400SW (all manufactured by Neos Co., Ltd.), Polyfox PF-136A, PF-156A, PF-151N, PF-154, PF-159 (manufactured by Omniova), Unidyne DSN-403N (manufactured by Daikin Industries, Ltd.) Among these, FS-3100, FS-34, FS- of The Chemours Co., Ltd., from the viewpoint of remarkably improving good print quality, particularly color development, penetrability to paper, wettability, and leveling property. 300, FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW manufactured by Neos Co., Ltd., Polyfox PF-151N manufactured by Omninova, and Unidyne DSN-manufactured by Daikin Industries, Ltd. 403N is particularly preferable.

The content of the surfactant in the ink is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of excellent wettability and ejection stability and improvement in image quality, 0.001 mass is used. % Or more and 5% by mass or less are preferable, and 0.05% by mass or more and 5% by mass or less are more preferable.

<Defoamer>
The defoaming agent is not particularly limited, and examples thereof include a silicone-based defoaming agent, a polyether-based defoaming agent, and a fatty acid ester-based defoaming agent. These may be used alone or in combination of two or more. Among these, a silicone-based defoaming agent is preferable because it has an excellent defoaming effect.

<Preservatives and fungicides>
The antiseptic and antifungal agent is not particularly limited, and examples thereof include 1,2-benzisothiazolin-3-one.

<Rust inhibitor>
The rust preventive is not particularly limited, and examples thereof include acidic sulfites and sodium thiosulfate.

<pH adjuster>
The pH adjusting agent is not particularly limited as long as the pH can be adjusted to 7 or more, and examples thereof include amines such as diethanolamine and triethanolamine.

The physical characteristics of the ink 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 ink at 25 ° C. is preferably 5 mPa · s or more and 30 mPa · s or less, preferably 5 mPa · s or more and 25 mPa · s or less, from the viewpoint of improving the print density and character quality and obtaining good ejection properties. More preferred. Here, for the viscosity, for example, a rotary viscometer (RE-80L manufactured by Toki Sangyo Co., Ltd.) can be used. As the measurement conditions, it is possible to measure at 25 ° C. with a standard cone rotor (1 ° 34'x R24), a sample liquid volume of 1.2 mL, a rotation speed of 50 rpm, and 3 minutes.
The surface tension of the ink is preferably 35 mN / m or less, more preferably 32 mN / m or less at 25 ° C. from the viewpoint that the ink is preferably leveled on the recording medium and the drying time of the ink is shortened.
The pH of the ink is preferably 7 to 12, more preferably 8 to 11, from the viewpoint of preventing corrosion of the metal member in contact with the liquid.

The ink of the present invention is not particularly limited and may be appropriately selected depending on the intended purpose, but it cannot be used for conductive applications because it is not used for forming a conductive pattern.

<Recording medium>
The recording medium is not particularly limited, and plain paper, glossy paper, special paper, cloth, or the like can be used, but good image formation can be achieved even if a non-permeable base material is used.
The non-permeable base material is a base material having a surface having low water permeability and low absorbability, and includes a material that does not open to the outside even if there are many cavities inside, and more quantitatively. , A base material having a water absorption amount of 10 mL / m ² or less from the start of contact to 30 msec ^{1/2 in the Bristow method.}
As the non-permeable base material, for example, a plastic film such as a vinyl chloride resin film, a polyethylene terephthalate (PET) film, polypropylene, polyethylene, or a polycarbonate film can be preferably used.
The recording medium is not limited to that used as a general recording medium, and wallpaper, floor materials, building materials such as tiles, cloth for clothing such as T-shirts, textiles, leather and the like can be appropriately used. Further, ceramics, glass, metal, or the like can be used by adjusting the configuration of the path for transporting the recording medium.

The most preferable form of the recording medium of the present invention is one having a porous surface, and the porous material absorbs constituent components such as water other than the coloring material without absorbing silver particles in the ink. If possible, there is no particular limitation, but any print medium having holes for absorbing the solution constituting the ink may be used.
In the present invention, the pore refers to a void observed when the porous material formed on the recording medium is observed from the image recording side. As an observation method, it is possible to observe an image of the porous material on the recording medium using SEM.

The average pore size of the porous material is preferably 100 nm or more and 400 nm or less, the lower limit value is more preferably 150 nm or more, further preferably 200 nm or more, and the upper limit value is more preferably 300 nm or less. When the average pore diameter is 100 nm or more, an image excellent in metal glossiness and reproducibility can be obtained, and when it is 400 nm or less, an image excellent in scratch resistance can be obtained.
In the present invention, the average pore diameter refers to the average value of the two diagonal lines obtained by determining the lengths of the two diagonal lines, the longest and the shortest, with respect to the observed void. The length of the diagonal line is obtained from the porous SEM image. In the present invention, the average pore size of the porous material means the average value of the average pore size of the porous material.

The average thickness of the porous material is preferably 1 μm or more and 50 μm or less, and more preferably 5 μm or more and 30 μm or less. When the average thickness is 1 μm or more and 50 μm or less, the solution can be efficiently absorbed when the ink containing silver particles is applied, and a silver-colored high-magnification printed surface can be obtained.
In the present invention, the thickness of the porous material can be calculated from the SEM image on the cut surface of the recorded material in the vertical direction. Specifically, the thickness of the porous material at a total of three points: the midpoint of the cross section of the recorded object, the midpoint between one end of the cross section and the midpoint, and the midpoint between the other end of the cross section and the midpoint. It refers to the average value of.

The porous material of the recording medium having porosity is not particularly limited and may be appropriately selected depending on the intended purpose. Paper; for resin-based substrates such as polyethylene terephthalate (PET) and vinyl chloride. Those having excellent film-forming property, film uniformity, adhesion, and safety are preferable.
Examples of the porous material include silica and alumina. These may be used alone or in combination of two or more.

The porous material may be a recording medium commercially available in which a porous layer containing silica or alumina is provided, and a coating liquid containing alumina or silica is separately used as a non-absorption (low absorption) recording medium. It may be coated to form a porous material.

The porous material can be formed by using a commercially available silica or alumina sol or a gel-like coating material.

As the coating material, the shape of silica or alumina may be spherical, or particles may be connected in a beaded shape or branched by a special treatment (chain shape, pearl necklace shape, etc.).
Further, the surface of the coating material may be modified with ions or compounds such as ammonia, calcium and alumina.

As the coating material, as silica, Snowtex S, Snowtex N, Snowtech UP, ST-XS, ST-O, ST-C, ST-20 (all manufactured by Nissan Chemical Industries, Ltd.), Cataloid SI- 350, Cataloid SI-30, SN, SA, S-20L, S-20H, S-30L, S-30H (above, manufactured by JGC Catalysts and Chemicals Co., Ltd.), Aerosil 200, 200V, 200CF, 300 (above, Nippon Aerosil) (Manufactured by Kawaken Co., Ltd.); Examples of alumina include alumina clearsol 5S, F1000, F3000, A2 (all manufactured by Kawaken Fine Chemical Co., Ltd.). These may be used alone or in combination of two or more.

Examples of the method for forming the porous material include a blade coating method, a gravure coating method, a bar coating method, a roll coating method, a dip coating method, a curtain coating method, a slide coating method, a die coating method, and a spray coating method.

As the recording medium having porosity, a commercially available product can be used. Examples of the commercially available products include IJ film RM-1GP01 (manufactured by Ricoh Co., Ltd., porous average pore size: 230 nm), NB-WF-3GF100 (porous average pore size: 210 nm), and NB-RC-3GR120 (manufactured by Ricoh Co., Ltd.). Porous average pore size: 250 nm) (Mitsubishi Paper Co., Ltd.) PT-201A420 (Porous medium average pore size: 270 nm), SD-101A450 (Porous medium average pore size: 250 nm), GL-101A450 (Porous medium average pore size: 250 nm) : 240 nm), GP501A450 (Porous medium pore size: 250 nm), SP-101A450 (Porous medium average pore size: 210 nm), PT-101A420 (Porous medium average pore size: 240 nm), PR101 (Porous medium average pore size: 270 nm) ) (Manufactured by Canon Inc.), EJK-QTNA450 (average pore size of porous: 200 nm), EJK-EPNA450 (average pore size of porous: 210 nm), EJK-CPNA450 (average pore size of porous: 220 nm), EJK-RCA450 (Porous average pore size: 240 nm), EJK-CGNA450 (Porous medium average pore size: 190 nm), EJK-GANA450 (Porous medium average pore size: 180 nm), EJK-NANA450 (Porous medium average pore size: 170 nm), EJK -EGNA450 (average pore size of porous: 200 nm) (manufactured by Elecom Co., Ltd.), WPA455VA (average pore size of porous: 200 nm), WPA450PRM (average pore size of porous: 210 nm), G3A450A (average pore size of porous: 220 nm) , G3A450A (Porous average pore size: 210 nm), WPA420HIC (Porous medium average pore size: 280 nm) (manufactured by Fujifilm Co., Ltd.), KA420SCHKR (Porous medium average pore size: 240 nm), KA450PSKR (Porous medium average pore size: 230 nm) ), KA450SLU (Porous average pore size: 210 nm) (manufactured by Seiko Epson Co., Ltd.), BP71GAA4 (Porous medium average pore size: 220 nm) (manufactured by Brother Industries, Ltd.) and the like.

<Resin layer>
The resin layer is preferably arranged on the printing layer.

The resin used for the resin layer preferably has high transparency.
Examples of the resin include polyethylene terephthalate (PET) resin, polypropylene (PP) resin, nylon and the like.

As a coating method of the resin, a method of coating the printed surface or the entire printed matter by a laminating treatment is preferable.
Alternatively, a method of coating with an overcoat in which the transparent resin is dissolved in water or a solvent and applied may be used.

Examples of the method for forming the resin layer include a blade coating method, a gravure coating method, a bar coating method, a roll coating method, a dip coating method, a curtain coating method, a slide coating method, a die coating method, and a spray coating method.

The average thickness of the resin layer is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 5 μm or more and 300 μm or less from the viewpoint of the b * value after resin coating.

When only the ink is printed directly on the recording medium, the printed matter is in a state where the silver pigment is adhered to the recording medium, so that the scratch resistance tends to be insufficient by this alone. Further, especially when the pigment in the ink is silver nanoparticles, there is a problem that the color becomes unnatural silver. Further, when silver ink is printed after printing a resin ink that does not contain a coloring material, the scratch resistance is improved to some extent, but it is still insufficient, and there is a problem that the color becomes unnatural silver. .. Therefore, by providing a transparent resin layer on the print layer, scratch resistance can be improved.

<Recorded material>
The ink recording material of the present invention comprises an image formed by using the ink of the present invention on a recording medium.
It can be recorded by an inkjet recording device and an inkjet recording method to obtain a recorded material.

<Recording device, recording method>
The following describes the case where black (K), cyan (C), magenta (M), and yellow (Y) are used, but if an ink containing silver is used instead of or in addition to these, ink containing silver is used. good.
The ink of the present invention can be suitably used for various recording devices by an inkjet recording method, for example, a printer, a facsimile device, a copying device, a printer / fax / copier multifunction device, a three-dimensional modeling device, and the like.
In the present invention, the recording device and the recording method are devices capable of ejecting ink, various processing liquids, and the like to a recording medium, and a method of recording using the device. The recording medium means a medium to which ink and various treatment liquids can adhere even temporarily.
This recording device can include not only a head portion for ejecting ink, but also means related to feeding, transporting, and discharging paper of a recording medium, and other devices called pretreatment devices and posttreatment devices. ..
The recording device and recording method may include a heating means used in the heating step and a drying means used in the drying step. The heating means and the drying means include, for example, means for heating and drying the print surface and the back surface of the recording medium. The heating means and the drying means are not particularly limited, but for example, a hot air heater and an infrared heater can be used. Heating and drying can be performed before printing, during printing, after printing, and the like.
Further, the recording device and the recording method are not limited to those in which significant images such as characters and figures are visualized by ink. For example, those that form patterns such as geometric patterns and those that form a three-dimensional image are also included.
Further, the recording device includes both a serial type device that moves the discharge head and a line type device that does not move the discharge head, unless otherwise specified.
Further, as this recording device, it is possible to use not only a desktop type but also a wide recording device capable of printing on an A0 size recording medium, or, for example, continuous paper wound in a roll shape as a recording medium. A continuous line printer is also included.
An example of the recording device will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective explanatory view of the device. FIG. 2 is a perspective explanatory view of the main tank. The image forming apparatus 400 as an example of the recording apparatus is a serial type image forming apparatus. A mechanical unit 420 is provided in the exterior 401 of the image forming apparatus 400. Each ink storage section 411 of the main tank 410 (410k, 410c, 410m, 410y) for each color of black (K), cyan (C), magenta (M), and yellow (Y) is, for example, a package of an aluminum laminated film or the like. It is formed of members. The ink container 411 is housed in, for example, a plastic container case 414. As a result, the main tank 410 is used as an ink cartridge for each color.
On the other hand, a cartridge holder 404 is provided behind the opening when the cover 401c of the apparatus main body is opened. A main tank 410 is detachably attached to the cartridge holder 404. As a result, each ink ejection port 413 of the main tank 410 and the ejection head 434 for each color communicate with each other via the supply tube 436 for each color, and ink can be ejected from the ejection head 434 to the recording medium.

This recording device can include not only a portion that ejects ink, but also a device called a pretreatment device, a posttreatment device, and the like.
As one aspect of the pretreatment apparatus and the posttreatment apparatus, it has a pretreatment liquid and a posttreatment liquid as in the case of inks such as black (K), cyan (C), magenta (M), and yellow (Y). There is an embodiment in which a liquid accommodating portion and a liquid discharge head are added, and a pretreatment liquid or a posttreatment liquid is discharged by an inkjet recording method.
As another aspect of the pretreatment device and the posttreatment device, there is a mode in which a pretreatment device and a posttreatment device by, for example, a blade coating method, a roll coating method, and a spray coating method are provided other than the inkjet recording method.

The method of using the ink is not limited to the inkjet recording method, and can be widely used. In addition to the inkjet recording method, examples thereof include a blade coating method, a gravure coating method, a bar coating method, a roll coating method, a dip coating method, a curtain coating method, a slide coating method, a die coating method, and a spray coating method.

The use of the ink of the present invention is not particularly limited and may be appropriately selected depending on the intended purpose. For example, it can be applied to printed matter, paints, coating materials, base materials and the like. Further, it can be used not only as an ink to form two-dimensional characters and images, but also as a three-dimensional modeling material for forming a three-dimensional three-dimensional image (three-dimensional model).
A known three-dimensional modeling device can be used for modeling the three-dimensional object, and the device is not particularly limited, and for example, an device provided with ink accommodating means, supply means, ejection means, drying means, and the like is used. be able to. The three-dimensional model includes a three-dimensional model obtained by overcoating with ink. In addition, a molded product obtained by processing a structure in which ink is applied on a base material such as a recording medium is also included. The molded product is, for example, a recorded material or structure formed in the form of a sheet or a film, which has been subjected to a molding process such as heat stretching or punching. For example, an automobile, an OA device, or electricity. -Suitably used for molding after decorating the surface of electronic devices, meters of cameras, panels of operation parts, etc.

In addition, image formation, recording, printing, printing, etc. in the terms of the present invention are all synonymous terms.

Recording media, media, and printed matter are all synonymous.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

<Preparation example of resin emulsion>
1,500 g of polycarbonate diol (reaction product of 1,6-hexanediol and dimethyl carbonate), 220 g of 2,2-dimethylolpropionic acid (DMPA) and 220 g of polycarbonate diol (reaction product of 1,6-hexanediol and dimethyl carbonate) were placed in a reaction vessel containing a stirrer, a reflux condenser, and a thermometer. 1,347 g of dipropylene glycol dimethyl ether (bp 171 ° C.) was charged under a nitrogen stream and heated to 60 ° C. to dissolve DMPA.
Next, 1,445 g of 4,4'-dicyclohexylmethane diisocyanate and 2.6 g of dibutyltin dilaurylate (catalyst) were added and heated to 90 ° C. for 5 hours to carry out a urethanization reaction to obtain an isocyanate-terminated urethane prepolymer. It was.
The reaction mixture was cooled to 80 ° C., and 149 g of triethylamine was added to the mixture. 4,340 g of the mixture was extracted and added to a mixed solution of 5,400 g of water and 15 g of triethylamine under strong stirring.
Next, 1,500 g of ice was added, and 626 g of a 35% by mass 2-methyl-1,5-pentanediamine aqueous solution was added to carry out a chain extension reaction, and the solvent was distilled off so that the solid content concentration became 30% by mass. Then, a polycarbonate-modified urethane resin emulsion (30% by mass of urethane resin component, 64% by mass of water, 6% by mass of dipropylene glycol dimethyl ether) was obtained.
Next, 10,000 g of the obtained polycarbonate-modified urethane resin emulsion was extracted, and 2,000 g of water was added under strong stirring to add the resin emulsion (urethane resin component 25% by mass, water 70% by mass, dipropylene glycol dimethyl ether 5% by mass). Got
The obtained resin emulsion was applied onto a slide glass to a thickness of 10 μm, dried at 100 ° C. for 30 minutes to form a resin film, and used with a micro surface hardness tester (FISCHERSCOPE HM2000, manufactured by Fisher). The Martens hardness when the Vickers indenter was pushed in with a load of 9.8 mN was 120 N / mm ² .

(Preparation Example 1 of Silver Particle Dispersion Solution)
<Preparation of silver particle dispersion 1>
66.8 g of silver nitrate, dispersant polymer having a carboxyl group (manufactured by Big Chemie Japan Co., Ltd., trade name: "Disperbic 190", solvent: water, 40% by mass of non-volatile component, acid value: 10 mgKOH / g, amine value: 0 mgKOH / G) 7.2 g and 1.8 g of cole acid (manufactured by Wako Pure Chemical Industries, Ltd.) were put into 100 g of ion-exchanged water and stirred vigorously to obtain a suspension. To this suspension, 100 g of dimethylaminoethanol (manufactured by Wako Pure Chemical Industries, Ltd.) was gradually added so that the water temperature did not exceed 50 ° C., and then heated and stirred in a water bath at a water temperature of 60 ° C. for 2 hours. .. The obtained reaction solution is filtered through a glass filter (manufactured by ADVANTEC, GC-90, average pore size: 0.8 μm) to obtain a silver particle dispersion containing 15% by mass of silver and 37.8% by mass of water. It was.
When the particle size distribution of the obtained silver particle dispersion 1 was measured using a particle size analyzer (Nanotrac Wave-EX150, manufactured by Nikkiso Co., Ltd.), the 50% cumulative volume particle size (D50) was 5 nm and 90% cumulative. The volumetric particle size (D90) was 30 nm.

(Preparation Examples 2 to 3 of Silver Particle Dispersion Solution)
<Preparation of silver particle dispersion liquid 2-3>
In Preparation Example 1 of the silver particle dispersion, the rate at which dimethylaminoethanol is added so as to have a 50% cumulative volume particle size (D50) and a 90% cumulative volume particle size (D90) of the silver particles shown in Table 1 below. In the same manner as in Preparation Example 1 of the silver particle dispersion, silver particle dispersions 2 to 3 containing 15% by mass of silver were obtained, except that the water temperature was adjusted.

(Preparation Example 4 of Silver Particle Dispersion Solution)
<Preparation of silver particle dispersion 4>
In the reaction vessel, 340 g of silver nitrate (manufactured by Kanto Chemical Co., Inc.) was added to 700 g of pure water and completely dissolved to prepare an aqueous silver nitrate solution. 700 g of ammonia water (manufactured by Kanto Chemical Co., Inc., special grade) adjusted to have an ammonia concentration of 25% by mass was added thereto, and the mixture was stirred to prepare an aqueous ammonia silver complex, and the temperature was adjusted to 23 ° C.
A reducing agent aqueous solution was prepared by dissolving 111 g of hydroquinone (manufactured by Kanto Chemical Co., Inc.) and 50 g of anhydrous potassium sulfite (manufactured by Kanto Chemical Co., Inc.) in 1,260 g of pure water in different containers, and the temperature was adjusted to 23 ° C. The above-mentioned ammine silver complex aqueous solution, which was also adjusted to a temperature of 23 ° C., was added to the reducing agent aqueous solution at once, and the mixture was stirred for 10 minutes to complete the reduction precipitation of silver particles.
Then, the silver particles were collected by filtering with a Büchner funnel, washed with water using 1 L of water three times, and dried to obtain silver particles.
15 parts by mass of the obtained silver particles, 3 parts by mass of Leodor TW-O120V (manufactured by Kao Co., Ltd.), and 82 parts by mass of pure water were added to a beaker, and after sufficiently stirring with a stirrer, an ultrasonic homogenizer (stock) was cooled with water. A silver particle dispersion liquid 4 containing 15% by mass of silver was obtained by treating with 200 μA for 1 hour with US-300T (chip diameter: 26 mm) manufactured by Nippon Seiki Seisakusho Co., Ltd. for 1 hour.
When the particle size distribution of the obtained silver particle dispersion 4 was measured using a particle size analyzer (Nanotrac Wave-EX150, manufactured by Nikkiso Co., Ltd.), the 50% cumulative volume particle size (D50) was 1,540 nm and 90. % Cumulative volume particle size (D90) was 3,020 nm.

(Preparation Example 5 of Silver Particle Dispersion Solution)
<Preparation of silver particle dispersion 5>
Polyethylene terephthalate (PET) film (manufactured by Toyo Boseki Co., Ltd., E-5100, average thickness 100 μm) is corona-treated, and the surface thereof is made of polyvinylpyrrolidone K15 (manufactured by Kanto Chemical Co., Inc.) 5% by mass, fluorine-based surfactant (Capstone). FS-3100 (manufactured by DuPont) 0.1% by mass, diethylene glycol-n-butyl ether (manufactured by Kanto Chemical Co., Inc.) 10% by mass, and ion-exchanged water 84.9% by mass are mixed and dissolved in a coating liquid with a bar coater. The PET film was coated and dried at 70 ° C. for 15 minutes to prepare a PET film in which a release resin layer was coated on the PET film.
Using a vacuum vapor deposition apparatus, a silver vapor deposition layer having an average thickness of 100 nm was formed on the PET film to prepare a thin-film PET film.
The obtained thin-layer PET film was immersed in high pure water and peeled off with an ultrasonic cleaner (VS-150, manufactured by AS ONE Corporation). After peeling the silver thin layer film together with the peeling resin layer from the PET film by the treatment for 2 hours, the PET film is removed and 1,000 G is applied in a centrifuge for 1 hour to separate the silver thin layer film as a precipitation component. did. The supernatant was discarded, pure water was added and dispersed again, and the work of precipitating and separating by centrifugation was performed three times to wash the silver thin layer film.
The solid content of the precipitated component is determined by thermogravimetric analysis, and 10 parts by mass of Leodor TW-O120V (manufactured by Kao Co., Ltd.) is added to 100 parts by mass of silver solid content to make the silver solid content 15% by mass. Pure water was added as described above, and the mixture was treated with an ultrasonic homogenizer (US-300T, manufactured by Nippon Seiki Seisakusho Co., Ltd., chip diameter: 26 mm) at 200 μA for 1 hour while cooling with water to carry out a dispersion treatment.
The obtained silver thin film dispersion is pressure-filtered with a SUS mesh filter (manufactured by Paul, LCF-241) having an average pore size of 18 μm, and subsequently with a cellulose acetate membrane filter having an average pore size of 5 μm. The coarse particles were removed by pressure filtration to obtain a silver particle dispersion 5 containing 15% by mass of silver.
When the particle size distribution of the obtained silver particle dispersion 5 was measured using a particle size analyzer (Nanotrac Wave-EX150, manufactured by Nikkiso Co., Ltd.), the 50% cumulative volume particle size (D50) was 1,610 nm and 90. % Cumulative volume particle size (D90) was 1,890 nm.

(Preparation Example 6 of Silver Particle Dispersion Solution)
<Preparation of silver particle dispersion 6>
Silver particles (trade name: AGC-2011, manufactured by Fukuda Metal Leaf Powder Industry Co., Ltd.) 15 parts by mass, anionic surfactant (trade name: Pionin A-51-B, manufactured by Takemoto Oil & Fat Co., Ltd.) 2 parts by mass, and ion exchange After premixing 83 parts by mass of water, treat with an ultrasonic homogenizer (US-300T, manufactured by Nippon Seiki Seisakusho Co., Ltd., chip diameter: 26 mm) at 200 μA for 1 hour while cooling with water to disperse, and 15% by mass of silver. A pigment dispersion containing 6 was obtained.
When the particle size distribution of the obtained silver particle dispersion 6 was measured using a particle size analyzer (Nanotrac Wave-EX150, manufactured by Nikkiso Co., Ltd.), the 50% cumulative volume particle size (D50) was 2,053 nm and 90. % Cumulative volume particle size (D90) was 4,950 nm.

(Preparation Example 7 of Silver Particle Dispersion Solution)
<Preparation of silver particle dispersion 7>
Silver particles (trade name: AGC-156I, manufactured by Fukuda Metal Leaf Powder Industry Co., Ltd.) 15 parts by mass, anionic surfactant (trade name: Pionin A-51-B, manufactured by Takemoto Oil & Fat Co., Ltd.) 2 parts by mass, and ion exchange After premixing 83 parts by mass of water, treat with an ultrasonic homogenizer (US-300T, manufactured by Nippon Seiki Seisakusho Co., Ltd., chip diameter: 26 mm) at 200 μA for 1 hour while cooling with water to disperse, and 15% by mass of silver. A pigment dispersion 7 containing the mixture was obtained.
When the particle size distribution of the obtained silver particle dispersion 7 was measured using a particle size analyzer (Nanotrac Wave-EX150, manufactured by Nikkiso Co., Ltd.), the 50% cumulative volume particle size (D50) was 2,801 nm and 90. % Cumulative volume particle size (D90) was 8,560 nm.

(Preparation Example 8 of Silver Particle Dispersion Solution)
<Preparation of silver particle dispersion 8>
Preparation of Silver Particle Dispersion Solution 1 The silver particle dispersion solution 1 obtained in Example 1 is concentrated by a rotary evaporator, filtered through a glass filter (ADVANTEC, GC-90, average pore size: 0.8 μm), and silver is 25. A silver particle dispersion 8 containing mass% was obtained.
When the particle size distribution of the obtained silver particle dispersion 8 was measured using a particle size analyzer (Nanotrac Wave-EX150, manufactured by Nikkiso Co., Ltd.), the 50% cumulative volume particle size (D50) was 5 nm and 90% cumulative. The volumetric particle size (D90) was 30 nm.

(Ink Preparation Example 1)
<Preparation of ink 1>
The materials of the following formulation are mixed and stirred so as to have a total of 100 parts by mass, and then filtered using a filter (LCF-24110, manufactured by Nippon Pole Co., Ltd., SUS304L rigid mesh, filtration accuracy: 18 μm) to obtain ink 1. Obtained.
-Prescription-
・ Silver particle dispersion 1 ・ ・ ・ 33.4 parts by mass ・ 2-Amino-2-methyl-1,3-propanediol (manufactured by Tokyo Kasei Kogyo Co., Ltd.) ・ ・ ・ 0.2 parts by mass ・ 2,4 7,9-Tetramethyldecane-4,7-diol (manufactured by Tokyo Kasei Kogyo Co., Ltd.) ・ ・ ・ 0.5 parts by mass ・ 1,2-propanediol (manufactured by Tokyo Kasei Kogyo Co., Ltd., bp: 188 ° C) ・・ ・ 10.2 parts by mass ・ 3-Ethyl-3-hydroxymethyloxetane (manufactured by Tokyo Kasei Kogyo Co., Ltd., bp: 240 ° C.) ・ ・ ・ 15.0 parts by mass ・ Antiseptic and antifungal agent (trade name: Proxel LV, Abyssia) ・ ・ ・ 0.1 parts by mass ・ Silicone surfactant (trade name: KF-351A, manufactured by Shin-Etsu Chemical Industry Co., Ltd.) ・ ・ ・ 1.0 parts by mass ・ Ion exchanged water ・ ・ ・ Remaining amount

(Ink Preparation Examples 2-32)
<Preparation of inks 2-32>
In Ink Preparation Example 1, as shown in Tables 2 to 5 below, the type and amount of silver particle dispersion, the type and amount of amine compound added, the amount of resin emulsion added, and the amount of 1,2-propanediol added. Inks 2 to 32 were obtained in the same manner as in Preparation Example 1 of the ink except that the above was changed.

※樹脂エマルジョン：樹脂エマルジョンの調製例のポリカーボネート変性ウレタン樹脂エマルジョン

* Resin emulsion: Polycarbonate-modified urethane resin emulsion of the preparation example of resin emulsion

As the amine compound, the compounds described below were used.
・ Tri (hydroxymethyl) aminomethane (manufactured by Tokyo Chemical Industry Co., Ltd.)
・ 2-Amino-1,3-propanediol (manufactured by Tokyo Chemical Industry Co., Ltd.)
-2-Amino-2-ethyl-1,3-propanediol (manufactured by Tokyo Chemical Industry Co., Ltd.)
・ 3-Amino-1,2-propanediol (manufactured by Tokyo Chemical Industry Co., Ltd.)
・ (2S, 3S, 4R) -2-amino-1,3,4-octanedecantorol (manufactured by Tokyo Chemical Industry Co., Ltd.)
・ Triethanolamine (manufactured by Tokyo Chemical Industry Co., Ltd.)
・ 2-Methylaminomethanol (manufactured by Tokyo Chemical Industry Co., Ltd.)

<Examples 1-32, Comparative Examples 1-4>
First, using an inkjet printer (IPSiO GXe5500 manufactured by Ricoh Co., Ltd.), a solid image of 5 cm × 5 cm is ejected to the recording medium shown in Table 6 at 300 dpi × 300 dpi and 30 pL per pixel at 25 ° C. Then, the recorded matter was obtained by recording the inks shown in Tables 6 to 7.

Next, the obtained recorded material was evaluated for "ink aging evaluation", "glossiness", "scratch resistance", and "mapping property" as follows. The results are shown in Table 8.

<Evaluation over time of ink>
-Storage stability (viscosity change rate)-
The viscosity of the obtained inks 1 to 32 after 24 hours was set to the initial viscosity η1, and the viscosity with time after being stored in a constant temperature layer at 70 ° C. for 2 weeks and accelerated over time was set to η2, and the E-type viscometer “ELD type viscometer” was used. It was measured using (manufactured by Toki Sangyo Co., Ltd.) under the conditions of 25 ° C. and a rotation speed of 50 rpm. The viscosity change rate was obtained by dividing the difference between the initial viscosity and the viscosity with time by the value of the initial viscosity, and was evaluated based on the following evaluation criteria. In addition, the presence or absence of sediment was visually confirmed. It should be noted that B or higher is a level at which there is no practical problem, and A or higher is preferable.
-Evaluation criteria-
S: The viscosity change rate is within ± 2%, and the sediment cannot be visually confirmed.
A: The viscosity change rate exceeds ± 2% and is within ± 5%, and the sediment cannot be visually confirmed.
B: The viscosity change rate exceeds ± 2% and is within ± 5%, and there are 5 or less sediments.
C: The rate of change in viscosity exceeds ± 5%, or there are more than 5 sediments.

-Discharge stability (nozzle missing)-
The obtained inks 1 to 22 are filled in an inkjet printer (IPSiO GXe5500 manufactured by Ricoh Co., Ltd.), and a nozzle check pattern is printed on glossy inkjet paper (painting photo finishing Value, manufactured by Fujifilm Co., Ltd.). The number of ejected nozzles from which inks 1 to 22 were ejected was confirmed for the total number of nozzles 384, and "nozzle omission" was evaluated based on the following evaluation criteria. It should be noted that B or higher is a level at which there is no practical problem, and A or higher is preferable.
-Evaluation criteria-
S: The number of discharge nozzles is 384
A: Number of discharge nozzles is 336 or more and less than 384 B: Number of discharge nozzles is 192 or more and less than 336 C: Number of discharge nozzles is less than 192

(Glossiness)
A gloss meter (manufactured by BYK Gardener, Microtri) measures the 20 ° glossiness of a dried printed matter of a 5 cm × 5 cm solid image formed by ejecting ink at 300 dpi × 300 dpi and 30 pL per pixel with respect to a recording medium. Gross) was measured, and "glossiness" was evaluated based on the following evaluation criteria. It should be noted that B or higher is a level at which there is no practical problem, and A or higher is preferable.
-Evaluation criteria-
S: 20 ° glossiness is 800 or more and A: 20 ° glossiness is 500 or more and less than 800 B: 20 ° glossiness is 350 or more and less than 500 C: 20 ° glossiness is 250 or more and less than 350 D: 20 ° glossiness is 250 Less than

(Mapability)
The mapability value C of the recorded material after drying of a 5 cm × 5 cm solid image formed by ejecting ink at 300 dpi × 300 dpi and 30 pL per pixel is defined as the device name: ICM-1 type (manufactured by Suga Test Instruments Co., Ltd.). ) Was used to measure the mapping property with an optical comb width of 2.0 mm by the mapping property measuring method specified in JIS-H8686, and the "mapping property" was evaluated based on the following evaluation criteria. It should be noted that B or higher is a level at which there is no practical problem, and A or higher is preferable.
-Evaluation criteria-
S: Reproducibility value C is 50 or more A: Reproducibility value C is 30 or more and less than 50 B: Reproducibility value C is 15 or more and less than 30 C: Reproducibility value C is 5 or more and less than 15 D: Reproducibility value C is 5 Less than

(Scratch resistance)
A Gakushin-type abrasion fastness tester (device name: AB-301) is used to record a solid image of 5 cm x 5 cm formed by ejecting ink at 300 dpi x 300 dpi with respect to a recording medium and 30 pL per pixel after drying. , Made by Tester Sangyo Co., Ltd.), rub 10 times with a friction element (load: 300 g) with white cotton cloth (compliant with JIS L0803) attached to the contact part, visually observe the deterioration condition, and evaluate as follows. "Scratch resistance" was evaluated based on the criteria. It should be noted that B or higher is a level at which there is no practical problem, and A or higher is preferable.
-Evaluation criteria-
S: The number of scratches is less than 5, and the background is invisible A: The number of scratches is 5 or more and less than 10 and the background is invisible B: The number of scratches is 10 or more and the background (printed matter) ) Is less than 5% C: There are 10 or more scratches, and 5% or more of the substrate (printed matter) is exposed.

As the recording medium, the one described below was used.
The average pore size of the porosity of the recording medium was determined by SEM observation of the surface of the recording medium.
Recording medium 1: Platinum photo paper (manufactured by ELECOM, EJK-QTA420), with ink receiving layer, porous average pore size: 200 nm
Recording medium 2: EPSON photo paper [glossy] (manufactured by EPSON, KA450PSKR), with ink receiving layer, porous average pore size: 90 nm
Recording medium 3: CANON Super Photo Paper (manufactured by CANON, SP-101A450), with ink receiving layer, porous average pore size: 120 nm
Recording medium 4: Color photographic finishing Pro (manufactured by Fuji Film Co., Ltd., WPA460PRO), with ink receiving layer, porous average pore size: 380 nm
Recording medium 5: Pictorico photo paper (manufactured by CANON, PPR200-A4 / 20), with ink receiving layer, porous average pore size: 430 nm

ただし、前記一般式（１）中、Ｒ^１は水素原子、メチル基、エチル基、又は−ＣＨ_２ＯＨを表し、ｎ１、及びｎ２は０〜１の整数を表す。
＜４＞ 前記インク中における前記銀の含有量が、１質量％以上１５質量％以下である前記＜１＞から＜３＞のいずれかに記載のインクである。
＜５＞ 前記インク中における前記アミン化合物の含有量が、０．１質量％以上５質量％以下である前記＜１＞から＜４＞のいずれかに記載のインクである。
＜６＞ 前記インク中における前記銀の含有量（Ａ）と、前記インク中における前記アミン化合物の含有量（Ｂ）との比率が、下記式（３）で表される前記＜１＞から＜５＞のいずれかに記載のインクである。
１≦Ａ（質量％）／Ｂ（質量％）≦５０・・・式（３）
＜７＞ 樹脂を更に含み、前記インク中における、前記樹脂の含有量が０．１質量％以上９質量％以下である前記＜１＞から＜６＞のいずれかに記載のインクである。
＜８＞ 前記＜１＞から＜７＞のいずれかに記載のインクを容器中に収容してなることを特徴とするインク収容容器である。
＜９＞ 前記＜１＞から＜７＞のいずれかに記載のインクと、前記インクを吐出するインク吐出部と、を有することを特徴とする画像記録装置である。
＜１０＞ 前記＜１＞から＜７＞のいずれかに記載のインクを、記録媒体に対して吐出する工程を含むことを特徴とする画像記録方法である。
＜１１＞ 前記記録媒体が、前記記録媒体の表面に多孔質を有し、前記多孔質の平均孔径が１００ｎｍ以上４００ｎｍ以下である前記＜１０＞に記載の画像記録方法である。
＜１２＞ 記録媒体上に、銀とアミン化合物を有し、前記アミン化合物がＮＨ_２基とＯＨ基を有し、前記アミン化合物が有する前記ＮＨ_２基の数Ｘと、前記ＯＨ基の数Ｙが、下記式（１）及び式（２）を満たすことを特徴とする記録物である。
３≦Ｘ＋Ｙ・・・式（１）
Ｘ≦Ｙ・・・式（２） Examples of aspects of the present invention are as follows.
<1> The amine compound contains silver, water, and an amine compound, the amine compound has _two NH groups and an OH group, and _{the number X of the two} NH groups and the number Y of the OH groups of the amine compound. Is an ink that satisfies the following formula (1) and the following formula (2).
3 ≤ X + Y ... Equation (1)
X ≤ Y ... Equation (2)
<2> The ink according to <1>, wherein the amine compound has a molecular weight of 300 or less.
<3> The ink according to <1> or <2>, wherein the amine compound is a compound represented by the following general formula (1).
General formula (1)

However, in the general formula (1), R ¹ represents a hydrogen atom, a methyl group, an ethyl group, or −CH ₂ OH, and n1 and n2 represent an integer of 0 to 1.
<4> The ink according to any one of <1> to <3>, wherein the content of silver in the ink is 1% by mass or more and 15% by mass or less.
<5> The ink according to any one of <1> to <4>, wherein the content of the amine compound in the ink is 0.1% by mass or more and 5% by mass or less.
<6> The ratio of the silver content (A) in the ink to the amine compound content (B) in the ink is from <1> to <1> represented by the following formula (3). 5> The ink according to any one of.
1 ≤ A (mass%) / B (mass%) ≤ 50 ... Equation (3)
<7> The ink according to any one of <1> to <6>, which further contains a resin and has a resin content of 0.1% by mass or more and 9% by mass or less in the ink.
<8> The ink container is characterized in that the ink according to any one of <1> to <7> is contained in the container.
<9> An image recording apparatus comprising the ink according to any one of <1> to <7> and an ink ejection unit for ejecting the ink.
<10> An image recording method comprising a step of ejecting the ink according to any one of <1> to <7> onto a recording medium.
<11> The image recording method according to <10>, wherein the recording medium has a porous surface on the surface of the recording medium, and the average pore diameter of the porous is 100 nm or more and 400 nm or less.
<12> The recording medium has a silver and an amine compound, the amine compound has _two NH groups and an OH group, and _{the number X of the two} NH groups and the number Y of the OH groups of the amine compound. Is a document characterized by satisfying the following equations (1) and (2).
3 ≤ X + Y ... Equation (1)
X ≤ Y ... Equation (2)

The ink according to any one of <1> to <7>, the ink container according to <8>, and the image recording device according to <9>, any one of <10> to <11>. The image recording method according to the above and the recorded matter according to the above <12> can solve the above-mentioned problems in the prior art and achieve the object of the present invention.

400 Image forming device 401 Image forming device exterior 401c Device body cover 404 Cartridge holder 410 Main tank 410k, 410c, 410m, 410y For each color of black (K), cyan (C), magenta (M), yellow (Y) Main tank 411 Ink storage unit 413 Ink discharge port 414 Storage container case 420 Mechanical unit 434 Discharge head 436 Supply tube

Japanese Unexamined Patent Publication No. 2005-030079 Japanese Patent No. 4165860

Claims (12)

Contains silver, water, amine compounds,
The amine compound has ₂ NH and OH groups and has
_{An ink characterized in that the number X of the two} NH groups and the number Y of the OH groups contained in the amine compound satisfy the following formulas (1) and (2).
3 ≤ X + Y ... Equation (1)
X ≤ Y ... Equation (2) The ink according to claim 1, wherein the amine compound has a molecular weight of 300 or less. The ink according to claim 1 or 2, wherein the amine compound is a compound represented by the following general formula (1).
General formula (1)

However, in the general formula (1), R ¹ represents a hydrogen atom, a methyl group, an ethyl group, or −CH ₂ OH, and n1 and n2 represent an integer of 0 to 1. The ink according to any one of claims 1 to 3, wherein the content of the silver in the ink is 1% by mass or more and 15% by mass or less. The ink according to any one of claims 1 to 4, wherein the content of the amine compound in the ink is 0.1% by mass or more and 5% by mass or less. The silver content (A) in the ink and
The ink according to any one of claims 1 to 5, wherein the ratio of the amine compound to the content (B) in the ink is represented by the following formula (3).
1 ≤ A (mass%) / B (mass%) ≤ 50 ... Equation (3) Contains more resin,
The ink according to any one of claims 1 to 6, wherein the content of the resin in the ink is 0.1% by mass or more and 9% by mass or less. An ink container, characterized in that the ink according to any one of claims 1 to 7 is contained in the container. The ink according to any one of claims 1 to 7 and
An ink ejection unit that ejects the ink and
An image recording device characterized by having. An image recording method comprising a step of ejecting the ink according to any one of claims 1 to 7 onto a recording medium. The image recording method according to claim 10, wherein the recording medium has a porous surface on the surface of the recording medium, and the average pore size of the porous medium is 100 nm or more and 400 nm or less. It has silver and amine compounds on the recording medium,
The recording medium has a porous surface on the recording medium, and the recording medium has a porous surface.
The average pore size of the porous material is 100 nm or more and 400 nm or less.
The amine compound has ₂ NH and OH groups and has
_{A recorded material characterized in that the number X of the two} NH groups and the number Y of the OH groups contained in the amine compound satisfy the following formulas (1) and (2).
3 ≤ X + Y ... Equation (1)
X ≤ Y ... Equation (2)

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