JP2003286423A - Ink set, and recording method and recording matter using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink set which can prevent discoloration of a recorded image. <P>SOLUTION: In the ink set provided with at least a yellow ink, a magenta ink and a cyan ink, the yellow ink comprises as a colorant at least C. I. Direct Yellow 58. The recording method comprises forming an image on a recording medium using the ink set. The recorded matter is obtained by forming an image on a recording medium using the ink set. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink set capable of preventing discoloration of an image and improving the storability of the image, and more specifically, an ink set including at least a yellow ink, a magenta ink and a cyan ink. The present invention relates to an ink set capable of preventing discoloration over time, a recording method and a recorded matter using the same.

[0002]

2. Description of the Related Art Conventionally, various recording methods have been developed in order to form a clear and high-quality color image (printed matter). In particular, because it is excellent in forming high-quality images, an ink set consisting of yellow ink, magenta ink, and cyan ink (hereinafter,
It is called "YMC ink set". ) Is used for the ink jet recording method. The magenta ink and the cyan ink referred to here include inks having a single density, and inks composed of a plurality of inks of two types (dark and light) having different color densities. The recorded image formed by these ink sets is required to have excellent storability such that deterioration over time such as discoloration or fading does not occur,
To this end, moisture resistance that does not bleed under high humidity environment,
Light resistance that does not deteriorate even when exposed to sunlight, indoor fluorescent lamps, and ultraviolet rays contained in them, and N in the atmosphere
It is desired to have gas resistance that does not deteriorate even by an oxidizing gas such as O ₂ , SO ₂ , or ozone.

Conventional ink sets have been mainly focused on moisture resistance and light resistance as an improvement of the storage stability of printed matter. As these storability are improved, the need to improve the gas resistance cannot be ignored. However, in the conventionally used ink set, discoloration due to gas occurs, and image deterioration is a serious problem. In the case of fading, the image becomes faint over time because it is a simple decrease in optical density, but there is little change in the impression of the image itself. However, discoloration has a great influence on the impression of an image, and prevention of discoloration is important from the viewpoint of image storability.

Therefore, an object of the present invention is to provide an ink set which can prevent discoloration of a recorded image.

[0005]

As a result of intensive studies, the inventors of the present invention have found that the cause of image discoloration by a conventional YMC ink set is the balance of gas fading characteristics (especially fading characteristics against ozone) of each color ink. It was found that the lack (especially, the first ink) was due to the lack, especially, the gas fading characteristics of the yellow ink being higher than that of each of the magenta ink and the cyan ink. That is, the colors of the image represented by the YMC ink set appear to have faded if the YMC colors have the same fading speed, but appear to be discolored if the fading speeds of the respective colors are significantly different.

Further, as a result of further investigation based on this first finding, the present inventors have identified as a yellow ink having the same gas fading characteristics as the magenta ink and the cyan ink in the conventional YMC ink set. We have found that an ink set using an ink containing a yellow dye can maintain the balance of gas fading characteristics of each color ink and can achieve the above-mentioned object (second finding).

The present invention has been made based on the above findings, and in an ink set including at least a yellow ink, a magenta ink, and a cyan ink, the yellow ink contains at least C.I. I. An ink set including Direct Yellow 58 is provided.

The present invention also provides a recording method characterized in that an image is formed on a recording medium using the ink set.

Further, the present invention provides a recorded matter characterized in that an image is formed on a recording medium using the ink set.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below based on its preferred embodiments. (Ink Set) The ink set of the present invention includes at least a yellow ink, a magenta ink, and a cyan ink, and the yellow ink contains at least C.I. I. It includes Direct Yellow 58.

The ink set of the present invention, as described above,
As a colorant for yellow ink, C.I. I. The direct yellow 58 is used, whereby the balance of the gas fading characteristics of the yellow ink, the magenta ink, and the cyan ink can be maintained, and thus the discoloration of the recorded image can be prevented.

The ink set of the present invention is used in a recording system using ink (ink composition). The recording method using ink is, for example, an inkjet recording method in which droplets of ink are ejected and adhered to a recording medium to perform printing,
A recording method using a writing instrument such as a pen and various other printing methods can be used. The ink set of the present invention is particularly preferably used in the inkjet recording system because it is excellent in color fastness of a recorded image formed by the inkjet recording system.

The ink set of the present invention comprises at least a yellow ink, a magenta ink and a cyan ink, and each of these inks will be described below.

(Yellow Ink in Ink Set) As described above, the yellow ink included in the ink set of the present invention contains C.I. I. Those containing Direct Yellow 58 are used.

C. I. The content of the Direct Yellow 58 is preferably 0.1 to 10% by weight, more preferably 0.5 to 5% by weight, and most preferably 1 in the yellow ink, because it can impart appropriate gas fading characteristics to the ink. ~ 3% by weight.

The yellow ink is C.I. I. With Direct Yellow 58, C.I. I. It is preferable to use in combination with one or more coloring agents selected from the group consisting of Direct Yellow 86, 132 and 173. By using these colorants in combination with the yellow ink, desired gas fading characteristics can be obtained while maintaining the color developability, light fastness and moisture fastness of the image to be formed.

C. I. Direct Yellow 86, 132
And the content of one or more colorants selected from the group consisting of 173 is preferably 0.1 to 4 in the yellow ink.
%, And more preferably 0.5 to 2.0% by weight.

In addition, C.I. I. Direct yellow 58
And C.I. I. Direct Yellow 86, 132 and 17
The mixing ratio with one or more colorants selected from the group consisting of 3 is preferably 1/4 to 4/1, and more preferably 1/3 to 3/1 in terms of weight ratio (former / latter).

The solvent and other optional components contained in the yellow ink will be described later.

(Magenta Ink in Ink Set) The magenta ink contained in the ink set of the present invention is not particularly limited and is the same as the magenta ink used in a normal ink set, particularly in an ink set for ink jet recording. May be used and may be composed of a plurality of magenta inks having a single density or two kinds of magenta inks having different color densities.

The colorant for magenta ink includes any colorant capable of exhibiting a magenta color, but is preferably a compound represented by the following general formula (I) or (II). (Dye). By using the compounds represented by the formulas (I) and (II), the light resistance and the humidity resistance of the image to be formed can be improved while maintaining the balance with the gas fading characteristics of the yellow ink and the cyan ink in the ink set. Can be improved. When using these colorants, the formulas (I) and (I
Selected from the group of compounds represented by I), alone or 2
It is also possible to use a mixture of two or more species.

[0022]

[Chemical 4]

[0023]

[Chemical 5]

Specific examples of the compound represented by the above formula (I) include the following.

[0025]

[Chemical 6]

[0026]

[Chemical 7]

[0027]

[Chemical 8]

[0028]

[Chemical 9]

[0029]

[Chemical 10]

[0030]

[Chemical 11]

[0031]

[Chemical 12]

[0032]

[Chemical 13]

[0033]

[Chemical 14]

[0034]

[Chemical 15]

[0035]

[Chemical 16]

[0036]

[Chemical 17]

Specific examples of the compound represented by the above formula (II) include the following.

[0038]

[Chemical 18]

[0039]

[Chemical 19]

[0040]

[Chemical 20]

[0041]

[Chemical 21]

[0042]

[Chemical formula 22]

[0043]

[Chemical formula 23]

[0044]

[Chemical formula 24]

[0045]

[Chemical 25]

[0046]

[Chemical formula 26]

[0047]

[Chemical 27]

The content of the colorant in the magenta ink is preferably 0.1 to 10% by weight, more preferably 0.3 to 4% by weight.

(Cyan Ink in Ink Set) The cyan ink included in the ink set of the present invention is not particularly limited, and is the same as the cyan ink used in a normal ink set, particularly in an ink jet recording ink set. Cyan ink having a single density or two kinds of cyan ink having different color densities may be used.

As the colorant for the cyan ink, any colorant capable of exhibiting a cyan color is included, but it is preferable to use a compound (dye) represented by the following general formula (III). It is the one that is selected. By using the compound represented by the formula (III), while maintaining the balance with the gas fading characteristics of the yellow ink and the magenta ink in the ink set, it is possible to improve the light resistance and moisture resistance of the image to be formed. it can. When using these colorants, one selected from the group of compounds represented by formula (III) may be used alone or two or more thereof may be mixed and used.

[0051]

[Chemical 28] Specific examples of the compound represented by the formula (III) include C.I.
I. Direct Blue 86, 87, 199 and the like can be mentioned.

The content of the colorant in the cyan ink is
Preferably 0.1 to 5.0% by weight, more preferably 0.1.
It is 5 to 4.0% by weight.

The solvent and other optional components contained in the cyan ink will be described later.

(Aspect of Ink Set) According to one preferred aspect of the present invention, an ink set comprising yellow ink, dark magenta ink, light magenta ink, dark cyan ink, and light cyan ink is provided. Further, according to another aspect of the present invention, there is provided an ink set including a yellow ink, a magenta ink, and a cyan ink each having a single density. Further, these ink sets may further include a black ink described later.

(Black Ink in Ink Set) In the present invention, a black ink may be further included in the ink set consisting of the yellow ink, the magenta ink and the cyan ink. According to the ink set further including such a black ink, it is possible to give a clearer impression especially in a black portion such as a character, and to widen a color reproduction range in a dark portion of an image to be formed to improve image quality in the dark portion. It can be further improved.

As the colorant contained in the black ink usable in the ink set of the present invention, any dye or pigment capable of printing black (black) can be used. Examples of such dyes include direct dyes, acid dyes, food dyes, basic dyes, reactive dyes, disperse dyes, vat dyes, soluble vat dyes, reaction disperse dyes, etc. Various dyes used for can be used. As such a pigment, a black pigment such as carbon black can be used.

In the present invention, the colorants contained in the black ink may be used alone or in combination of two or more.

In the present invention, the black ink particularly satisfies the light fastness and moisture fastness of the image to be formed,
In addition, as a colorant, C.I. I. Direct Black 195, C.I. I. Food Black 2, C.I. I. Sulfur Black 1, and C.I. I. Those containing one or more selected from the group consisting of reactive blacks 31 and 35 are preferable.

In addition to the above-mentioned preferable colorant, the black ink contains C.I. as a complementary color agent for bringing the black portion of the image to be formed close to a desired black color. I. Dyes other than black, such as direct yellow 132, may be included.

The content of the colorant in the black ink is preferably 0.1 to 10% by weight, more preferably 1
~ 8% by weight.

The solvent contained in the black ink and other optional components will be described later.

(Water in Each Ink, Water-Soluble Organic Solvent and Other Optional Components) In each ink used in the ink set of the present invention, the main solvent is preferably water or a mixed liquid of water and a water-soluble organic solvent. is there. As the water, pure water such as ion-exchanged water, ultrafiltered water, reverse osmosis water, distilled water, or ultrapure water can be used. Further, it is preferable to use water that has been sterilized by irradiation with ultraviolet rays or addition of hydrogen peroxide, since it is possible to prevent the generation of mold and bacteria when the ink is stored for a long period of time.

In each ink used in the ink set of the present invention, the content of water when used as the main solvent is preferably 50 to 90% by weight, and 60 to 80% by weight. More preferably, it is wt%.

According to a preferred embodiment of the present invention, the solvent of the ink used in the ink set of the present invention is a mixed liquid of water and a water-soluble organic solvent, and preferably further contains a penetrant. By using a penetrant, it is possible to enhance the penetrability of the ink into the recording medium, and it is possible to appropriately adjust the drying time of the ink by changing the type of the penetrant and the amount added to the ink. . Preferred examples of such penetrants include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, ethylene glycol. Mono-iso-propyl ether, diethylene glycol mono-iso-propyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol mono-t-butyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol mono-n-butyl ether, diethylene glycol mono- t-butyl ether, 1-methyl-
1-methoxybutanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-t-butyl ether,
Propylene glycol mono-n-propyl ether, propylene glycol mono-iso-propyl ether,
Propylene glycol mono-n-butyl ether, dipropylene glycol mono-n-butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-iso-propyl ether Examples thereof include alkyl ethers (glycol ethers) of polyhydric alcohols, and these can be used alone or as a mixture of two or more kinds.

The amount of these penetrants added is preferably in the range of about 3 to 30% by weight, more preferably about 5 to 20% by weight, based on the ink.

According to a preferred embodiment of the present invention, it is preferable that a wetting agent is further included as a solvent for the ink. Preferred examples of wetting agents include ethylene glycol, diethylene glycol, triethylene glycol,
Polyethylene glycol, polypropylene glycol,
Propylene glycol, butylene glycol, 1,2,
Polyhydric alcohols such as 6-hexanetriol, thioglycol, hexylene glycol, glycerin, trimethylolethane and trimethylolpropane; urea; 2
-Pyrrolidone, N-methyl-2-pyrrolidone; 1,3-
Examples thereof include dimethyl-2-imidazolidinone, formamide, acetamide, dimethylsulfoxide, sorbit, sorbitan, acetin, diacetin, triacetin, and sulfolane, and these can be used alone or as a mixture of two or more thereof.

The amount of these wetting agents added is preferably in the range of about 5 to 50% by weight, more preferably in the range of about 5 to 30% by weight, based on the ink.

Each ink used in the ink set of the present invention may further contain a surfactant. Examples of surfactants include anionic surfactants, nonionic surfactants, and acetylene glycol-based surfactants. These can be used alone or in combination of two or more.

In the present invention, among these surfactants, the use of an acetylene glycol-based surfactant, in particular, lowers the surface tension of the ink and suppresses the foaming property of the ink, resulting in an effect as an ink. The compound represented by the following formula (a) can be mentioned as a preferred specific example of the acetylene glycol-based surfactant.

[0070]

[Chemical 29] [In the above formula, 0 ≦ m + n ≦ 50, R ¹ , R ² , R ³ , and R ⁴ are independently an alkyl group (preferably having 1 to 1 carbon atoms).
6 alkyl group). ]

Among the compounds represented by the above formula (a), 2,4,7,9-tetramethyl-5-decyne-4,7-diol and 3,6-dimethyl-4-octyne are particularly preferable. -3,6-diol, 3,5-dimethyl-1-hexyn-3-ol and the like can be mentioned. It is also possible to use a commercially available product as the acetylene glycol-based surfactant represented by the above formula (a), and specific examples thereof include Surfynol 82, 104, 440, 465, 485, or TG. Air Products and Chemicals. Inc.
Available), Olfine STG, Olfine E10
10 (trade name) (above, manufactured by Nissin Chemical Co., Ltd.) can be mentioned.

The amount of the surfactant added is 0.1 to 5% by weight based on the total amount of the ink, which may be appropriately determined according to the desired drying time of the ink, but is 0.1 to 3% by weight. It is more preferable that the amount is 0.5 to 2% by weight. The surface tension of the ink used in the present invention is usually 45 mN / m or less, and is 25 to 45 mN / m.
It is preferably in the m range.

Each ink used in the ink set of the present invention further comprises a nozzle clogging preventive agent, an antiseptic agent or a fungicide agent, an antioxidant agent, a conductivity adjusting agent, a pH adjusting agent, a dissolution aid, and a viscosity adjusting agent. A permeation enhancer, a surface tension adjusting agent, an oxygen absorber and the like can be added.

Examples of preservatives and fungicides include sodium benzoate, sodium pentachlorophenol,
2-Pyridinethiol-1-oxide sodium, sodium sorbate, sodium dehydroacetate, 1,2
-Dibenzothiazolin-3-one (Proxel CRL, Proxel BDN, Proxel GX from Avecia)
L, Proxel XL-2, Proxel TN) and the like.

Further, examples of the pH adjusting agent, solubilizing agent, or antioxidant include amines such as diethanolamine, triethanolamine, propanolamine, and morpholine, and their modified products, potassium hydroxide, sodium hydroxide, Inorganic salts such as lithium hydroxide, ammonium hydroxide, quaternary ammonium hydroxide (tetramethylammonium, etc.), carbonates such as potassium carbonate, sodium carbonate, lithium carbonate and other phosphates, or N-methyl-2-pyrrolidone , Urea, thiourea,
L-ascorbic acid and salts thereof such as ureas such as tetramethylurea, alohanates and alohanates such as methylallohanate, biurets such as biuret, dimethylbiuret and tetramethylbiuret, and the like can be mentioned.

In the present invention, the other optional components described above may be used alone or as a mixture of a plurality of types selected in each group and between each group. In the present invention, the amount of all components of each ink is such that the ink viscosity is 2
It is preferably selected to be less than 10 mPa · s at 0 ° C.

(Recording Method) According to the present invention, there is provided a recording method for forming an image on a recording medium using the above-mentioned ink set. In particular, an inkjet recording method in which droplets of the ink contained in the above-mentioned ink set are ejected and adhered to a recording medium to perform printing is preferably provided. According to the recording method of the present invention, it is possible to form an image in which discoloration is prevented.

As a recording medium for forming an image,
The recording medium is not particularly limited, and various recording media, for example, recording media (paper) composed of pulp fibers, dedicated recording media for ink jet recording having an ink absorbing layer on the recording surface (printing surface) (special mat paper, gloss only) Paper, ink jet recording film, ink jet recording OHP sheet, etc. can be used.

(Recorded Product) According to the present invention, there is provided a recorded product in which an image is formed on a recording medium using the above-mentioned ink set. The recorded matter of the present invention is formed with an image in which discoloration is prevented.

[0080]

The present invention will be described in detail below with reference to examples, but these do not limit the scope of the present invention.

Examples 1 and 2 and Comparative Examples 1 and 2 (Preparation of Ink) Each component was stirred at a mixing ratio shown in Table 1 at room temperature for 30 minutes, filtered through a 1 μm membrane filter, and shown in Table 1. Each ink having the composition shown was obtained. The amount of each component of the ink shown in the table represents the weight% of each component with respect to the total amount of the ink, and the remaining amount is water (ultra pure water).

[0082]

[Table 1]

The details of the inks and compounds in Table 1 are as follows. Y, Y ₁ and Y ₀ are yellow inks, M is dark magenta ink, LM is light magenta ink, C is dark cyan ink, and LC is light cyan ink. -M-13 and M-4 are the chemical structures shown above.

Then, the obtained inks were used as ink sets of the following combinations to form an ink jet printer PM800C (Example 1, Comparative Example 1) and EP.
SON Stylus Color 760 (Example 2,
Comparative Example 2) (both manufactured by Seiko Epson Corporation) was used to fill these dedicated cartridges, and printing was performed on an inkjet recording medium (PM photo paper; manufactured by Seiko Epson Corporation) to obtain a recorded matter.

Ink set A (Example 1) ... Y, M, LM, C, LC Ink set A ₀ (Comparative example 1) ... Y ₀ , M, LM, C,
LC ink set B (Example 2) ... Y ₁ , M, C Ink set B ₀ (Comparative example 2) ... Y ₀ , M, C

Then, the following evaluation was carried out for each ink set. (Ozone exposure test) Ozone weather meter OMS-
Using H type (trade name, manufactured by Suga Test Instruments Co., Ltd.), 24 ° C 6
The recorded matter was exposed for a predetermined time (1 and 2 hours) under the conditions of 0% RH and ozone concentration of 10 ppm.

(Evaluation of Fading Balance Property Against Ozone Exposure) The OD value (Optical Density) of the image on the recorded matter after the exposure in the ozone exposure test was measured by the reflection densitometer (“SPM”).
-100 "(manufactured by Gretag), and the optical density residual ratio (Relict Optical Density; ROD) is calculated by the following formula.
I asked. The recorded matter includes a yellow image (Y image),
A magenta image (M image) and a cyan image (C image) were printed with color patches prepared so that their OD values were in the range of 0.9 to 1.1. ROD (%) = (D / D ₀ ) × 100 (D: OD after exposure test, D ₀ : OD before exposure test) The ROD thus obtained was used to evaluate the fading balance according to the following criteria.

A: The difference in ROD of each color is within 15%. B: The difference in ROD of each color is more than 15% and 30% or less. C: The difference in ROD of each color exceeds 30%. The ROD difference here means the difference between the maximum value and the minimum value.

(Evaluation of discoloration characteristics with respect to ozone exposure) YMC
The gray printed as the third color of the ink set of the system is
It is suitable for evaluating the color change characteristics due to the difference in the discoloration balance of each ink. Therefore, a gray patch consisting of the tertiary color of the YMC ink set created so that the OD value is in the range of 0.9 to 1.1 is printed, and the ozone exposure test is performed, and the recorded matter after exposure is printed. ΔE * was measured using a reflection densitometer.

The color difference ΔE * ab is the CIE (Commission Internation
al de l'Eclarirage) standardized by JIS (ie J
It is adopted in IS Z 8729). ΔE * ab = [(ΔL *) ² + (Δa *) ² + (Δb *) ² ] ^1/2 (i) (ΔL *, Δa *, and Δb * are L before and after exposure, respectively.
* Difference between a * and b *) The color difference ΔE * ab was obtained from the above formula, and the color change characteristics were evaluated according to the following criteria. A: The color difference ΔE * ab is 10 or less. B: The color difference ΔE * ab exceeds 10 and is 20 or less. C: Color difference ΔE * ab exceeds 20 and is 30 or less.

(Outdoor exposure test) A structure consisting of only a pillar and a roof was prepared so that it would not be exposed to direct sunlight and rain, and that the flow of air would not be obstructed by walls and obstacles. . This was installed outdoors, the recorded matter was placed therein, and exposed for a predetermined time (10 days and 25 days).

(Evaluation of Discoloration Property Against Outdoor Exposure) The above outdoor exposure test was conducted for 10 days and 25 days using a recorded matter on which a gray patch was printed in the same manner as in the case of evaluation of the discoloration characteristic against ozone exposure. Similar to the color change characteristic evaluation in the ozone exposure test, the color difference ΔE * ab was obtained, and the color change characteristic was evaluated according to the same criteria.

Table 2 shows the evaluation results of the color fading balance and discoloration characteristics of the ink sets of the examples and comparative examples.

[0094]

[Table 2]

In Table 2, "gas resistance (ROD%)" indicates the evaluation of discoloration balance property against ozone exposure, "gas resistance (gray)" indicates the evaluation of discoloration property against ozone exposure, and ""Left in the real environment (gray)" indicates the evaluation of the color change property against outdoor exposure.

As is clear from the results shown in Table 2, C.I. I.
The ink sets of Examples 1 and 2 using the yellow ink including the direct yellow 58 have C.I. I.
It can be seen that the ink set is improved over the ink sets of Comparative Examples 1 and 2 using the yellow ink that does not include the Direct Yellow 58.

[0097]

The ink set of the present invention can prevent discoloration of a recorded image. The present invention can further provide a recording method and recorded matter having such effects.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroshi Fukumoto             Seiko, 3-3-3 Yamato, Suwa City, Nagano Prefecture             -In Epson Corporation F-term (reference) 2C056 EA13 FC02                 2H086 BA56 BA59 BA62                 4J039 BC13 BE01 BE02 BE22 EA15                       EA16 EA17

Claims (14)

[Claims] 1. An ink set comprising at least yellow ink, magenta ink, and cyan ink,
The yellow ink contains at least C.I.
I. An ink set containing Direct Yellow 58. 2. The C.I. I. The ink set according to claim 1, wherein the content of the direct yellow 58 is 0.1 to 10% by weight in the yellow ink. 3. The yellow ink as a colorant,
Furthermore, C.I. I. Direct Yellow 86, 132 and 17
3. One or more selected from the group consisting of 3.
Or the ink set described in 2. 4. The magenta ink, as a colorant,
The ink set according to claim 1, comprising a compound represented by the following general formula (I) or (II). [Chemical 1] [Chemical 2] 5. The ink set according to claim 1, wherein the content of the colorant in the magenta ink is 0.1 to 10% by weight in the magenta ink. 6. The cyan ink contains a compound represented by the following general formula (III) as a colorant.
The ink set according to any one of 1. [Chemical 3] 7. The ink set according to claim 1, wherein the content of the colorant in the cyan ink is 0.1 to 5% by weight in the cyan ink. 8. The ink set according to claim 1, wherein the ink included in the ink set contains a penetrant. 9. The ink set according to claim 8, wherein the penetrant includes at least glycol ether. 10. The ink set according to claim 1, wherein the ink included in the ink set contains a surfactant. 11. The ink set according to claim 10, wherein the surfactant is an acetylene glycol-based surfactant. 12. The content of the surfactant is 0.1 to 5% by weight with respect to the total amount of the ink.
The ink set according to 1. 13. A recording method for forming an image on a recording medium using the ink set according to claim 1. 14. A recorded matter, wherein an image is formed on a recording medium using the ink set according to any one of claims 1 to 12.