JP2008189905A - Black dye ink for inkjet recording - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a black ink that can realize a good color balance both before and after the decoloration caused by light in the printed matter formed by the black dye ink for inkjet recording that comprises a black dye, a color dye for toning, a water-soluble organic solvent and water. <P>SOLUTION: The black dye ink for inkjet recording satisfies the following inequalities (1) and (2) simultaneously, ODimax(0)-ODimin(0)≤0.15 (1) and ODimax(1)-ODimin(1)≤0.15 (2) [wherein ODimax(0) and ODimin(0) are maximum and minimum optical densities, respectively; of the optical densities of Yellow, Magenta, and Cyan color components, respectively, of a solid black printed portion printed on glossy paper with the black dye ink and having an average optical density of 0.9 or more and 1.1 or less; and ODimax(1) and ODimin(1) are maximum and minimum optical density, respectively, of the optical densities of the Yellow, Magenta, and Cyan color components, respectively, after a predetermined light fastness test is performed on the solid black printed portion]. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a dye black ink for inkjet recording.

  Conventionally, black dye inks for inkjet recording using a single black dye have been widely used. For printed matter obtained by black solid printing on glossy paper with such dye black ink, the optical density is measured by dividing into yellow (Y) color component, magenta (M) color component and cyan (C) color component. Then, as shown in FIG. 3, the optical density is generally different for each color component. For this reason, a black solid print obtained from a black ink for inkjet recording using only a single black dye, for example, a bluish black when the Y color component is relatively weak as shown in FIG. It becomes.

  Therefore, in order to obtain black as close to an achromatic color as possible, the optical density of the Y color component, M color component, and C color component of the black solid printed matter printed with black ink is substantially the same (see FIG. 4). A color dye corresponding to a color component whose optical density is insufficient for a black dye is added for color matching (Patent Document 1). Therefore, the color balance of the printed matter obtained by using the dyed black ink for inkjet recording adjusted in this way (the balance of the optical density of the Y color component, the M color component, and the C color component of the black solid printed matter) is Naturally it will be good.

JP 2005-36164 A

  However, when sunlight or fluorescent light is irradiated onto a printed matter prepared using the dyed black ink for ink jet recording adjusted in color as described above, the dye is discolored and the optical density of the printed matter is reduced. In this case, if the color balance is maintained, even if the optical density of the printed matter is lowered, fading is not noticeable. However, in practice, between the components divided into the Y color component, the M color component, and the C color component. The degree of decrease in optical density is different. In addition, the color fading of the toning color dyes used together for black toning also overlaps. As described above, in the case of the toned black dye ink for ink jet recording, not only the optical density of the printed matter after the light irradiation is decreased, but also the color balance is greatly disturbed.

  The present invention is intended to solve the above-described conventional problems, and a printed matter using a black dye, a toning color dye, a water-soluble organic solvent, and a toned ink jet recording dye black ink containing water, An object is to realize a good color balance before and after fading by light.

  When the light resistance test is performed on the black solid print portion printed on the glossy paper using the toned black dye ink-jet recording ink as described above, the optical properties before and after the light resistance test are obtained. Rather than simply reducing the density difference, the optical density of the Y color component, the M color component, and the C color component is measured for the black solid print, and the maximum of these three components is measured before and after the light resistance test. The inventors have found that the above-described object can be achieved by setting the difference between the optical density and the minimum optical density to be equal to or less than a predetermined numerical value, thereby completing the present invention.

That is, the present invention is a black ink for inkjet recording containing a black dye, a toning color dye, a water-soluble organic solvent and water,
For black ink solid print portions with an average optical density of 0.9 or more and 1.1 or less printed on glossy paper using black ink, the optical density of the Y color component is ODiy (0), and the optical density of the M color component is ODim ( 0), the optical density of the C color component is ODic (0), the maximum optical density is ODimax (0) and the minimum optical density is ODimin (0) among ODiy (0), ODim (0), and ODic (0). Define
A predetermined light resistance test is performed on the black ink solid print portion. After the test, the optical density of the Y color component is ODiy (1), the optical density of the M color component is ODim (1), and the optical density of the C color component is ODic ( When the maximum optical density is defined as ODimax (1) and the minimum optical density is defined as ODimin (1) among these ODiy (1), ODim (1) and ODic (1), the following formula (1 ) And (2) are satisfied at the same time. A dye black ink for ink jet recording is provided.

  The dye black ink for ink-jet recording of the present invention has a three-component optical density of Y color component, M color component, and C color component before and after the light resistance test for a black ink solid print portion printed on glossy paper. The difference between the maximum optical density and the minimum optical density is 0.15 or less. For this reason, a good color balance can be realized both before and after the light resistance test.

  The dye black ink for ink-jet recording of the present invention contains a black dye, a toning color dye, a water-soluble organic solvent and water, and satisfies the following formulas (1) and (2) simultaneously.

  In the formulas (1) and (2), ODimax (0), ODimin (0), ODimax (1), and ODimin (1) mean the optical density described below. That is, for a black ink solid print portion having an average optical density of 0.9 or more and 1.1 or less printed on glossy paper using inkjet recording dye black ink, the optical density of the Y color component is set to ODiy (0), M color component ODim (0), and the optical density of the C color component is ODic (0). Of these ODiy (0), ODim (0) and ODic (0), the maximum optical density is the maximum optical density ODimax (0), and the minimum optical density is the minimum optical density ODimin (0). In addition, a predetermined light resistance test is performed on the black ink solid print portion, the optical density of the Y color component after the test is ODiy (1), the optical density of the M color component is ODim (1), and the optical density of the C color component is set. ODic (1). Of these ODiy (1), ODim (1), and ODic (1), the maximum optical density is the maximum optical density ODimax (1), and the minimum optical density is the minimum optical density ODimin (1).

  For reference, a list of definitions of optical density for the black ink solid print portion is shown below.

ODiy (0): Black ink solid printing part Y color component initial (before test) optical density ODim (0): Black ink solid printing part M color component initial (before test) optical density ODic (0): Black ink solid printing part C Initial (before test) optical density of color component ODimax (0): Initial (before test) maximum optical density of black ink solid printing part ODimin (0): Initial (before test) minimum optical density of black ink solid printing part ODiy (1) : Black ink solid print part Y color component post-test optical density ODim (1): Black ink solid print part M color component post-test optical density ODic (1): Black ink solid print part C color component post-test optical density ODimax (1 ): Maximum optical density after test of black ink solid print part ODimin (1): Minimum optical density after test of black ink solid print part

The light fastness test is as follows: “In a temperature 25 ° C., humidity 50% RH environment, light emitted from a xenon lamp is passed through a glass filter that cuts light of a wavelength of 320 nm or less, and then black ink solid printing is performed. Part or black dye solution solid print part is irradiated for 100 hours at an illuminance of 93 klux ”. Specifically, it can be carried out using a strong energy xenon weather meter SC780-WN manufactured by Suga Test Instruments Co., Ltd. The optical density value can be measured using Spectrolino (light source: D ₆₅ , viewing angle: 2 °, status A) manufactured by Gretag Macbeth. Here, “status A” indicates a spectral sensitivity characteristic conforming to ISO 5/3.

  FIG. 1 shows the relationship between ODimax (0), ODimin (0), ODimax (1), and ODimin (1). FIG. 1A shows a Y color component, an M color component, and a C color for a printed matter obtained by solid printing on a glossy paper using a black dye solution containing only a single black dye as a colorant. It is explanatory drawing of the optical density of a component. The optical density of the printed matter is a bluish black as a whole because the Y color component is significantly insufficient and the M color component is insufficient with respect to the C color component. Here, glossy paper refers to paper provided with a coating layer that gives surface smoothness to base paper (base paper). The reason for using glossy paper is that there is little ink bleeding when printing, and vivid color development is obtained. Specifically, photographic glossy paper BP61GLA manufactured by Brother Industries, Ltd .; manufactured by Oji Paper Co., Ltd. Color inkjet paper Premium photo glossy paper; Kokuyo Co., Ltd. inkjet printer paper Super glossy paper for high-definition photo output; Konica Minolta Holdings Co., Ltd. Photolike QP <Photo quality> series; Fuji Film Co., Ltd. ) Series Photo Finishing Pro, Photo Finishing Advance, and Fujifilm high-grade glossy paper. Further, since the black ink solid print portion is considered to cover the dark to light density of the printed matter with an optical density value of around 1.0, the initial (before test) average optical density ((ODiy (0) + ODim (0) + ODic (0)) / 3) is in the range of 0.9 to 1.1. The initial (before test) average optical density of 0.9 or more and 1.1 or less can be obtained by adjusting the gradation or the like of the solid printed matter.

  Next, as shown in FIG. 1B, a yellow dye and a magenta dye are used in combination with a black dye as the toning color dye, and the optical density of the Y color component and the M color component is set to C color, which is the highest optical density. The level is the same as the optical density of the component. Thereby, the color balance of the printed matter before the light resistance test is improved. In the present invention, the difference between any two of ODiy (0), ODim (0), and ODic (0) is always 0.15 or less. If the difference exceeds 0.15, the color balance is lost to an unacceptable level. In the case of FIG. 1B, the optical density ODim (0) of the M color component is ODimax (0), and the optical density ODic (0) of the C color component is ODimin (0).

  Further, in the present invention, even if a predetermined light resistance test is performed on the black ink solid print portion, as shown in FIG. 1C, any one of ODiy (1), ODim (1), and ODic (1) The difference between the two is always 0.15 or less. If the difference exceeds 0.15, the color balance is lost to an unacceptable level. In the case of FIG. 1C, the optical density ODiy (1) of the Y color component is ODimax (1), and the optical density ODic (1) of the C color component is ODimin (1).

  In the inkjet recording dye black ink of the present invention, printing is performed on glossy paper using a black dye solution, which is a constituent of inkjet recording dye black ink excluding toning color ink, a water-soluble organic solvent and water. For the black dye solution solid printed portion, the optical density of the Y color component is ODdy (0), the optical density of the M color component is ODdm (0), the optical density of the C color component is ODdc (0), and ODdy (0 ), ODdm (0) and ODdc (0), the maximum optical density is set to ODdmax (0), a predetermined light resistance test is performed on the black dye solution solid print portion, and the optical density of the Y color component after the test is set to ODdy. (1) The optical density of the M color component is ODdm (1), the optical density of the C color component is ODdc (1), and ΔODdy, ΔODdm, and ΔODdc defined by the following equations (3) to (5) When the maximum optical density difference is ΔODdmax, the color component indicating ΔODdmax is ODdmax (0) It is preferred to use a black dye constituting the black dye solution that matches the color components shown. Such a black dye is a black dye whose color component having the highest optical density is most likely to fade before the light resistance test in the Y, M, and C color components. As a result, the color balance after fading can be improved. In other words, if the color component with the highest optical density before the light resistance test is most difficult to fade, the optical density of the color component after the light resistance test is significantly higher than the optical density of the other color components. As a result, it is difficult to maintain the color balance. Since many black dyes used in the black ink for inkjet recording of the present invention are tinged with cyan, it is preferable that the color component showing ΔODdmax has a large reduction rate of the optical density of the C component.

  In addition, as a black dye solution, it is preferable to use what is obtained, for example by mixing uniformly the composition except the toning color dye from the composition of the inkjet recording dye black ink. In this case, an amount of water or a water-soluble organic solvent or a mixed solvent thereof corresponding to the removed toning color dye may be added to the black dye solution. Thereby, an evaluation test can be performed without greatly changing the concentration of the black dye from that of the black ink for inkjet recording. In addition, when selecting the black dye solution solid print portion, the black dye solution in which the optical density of the color component showing the highest optical density among the Y color component, the M color component, and the C color component is 0.9 or more and 1.1 or less. It is preferable to select a solid print portion. Thereby, the comparison with the evaluation test of the dye black ink for inkjet recording becomes easy. When the optical density of the color component showing the highest optical density does not reach 0.9, the black dye density is increased so that the optical density becomes 0.9 or more and 1.1 or less, or the gradation of printing It may be adjusted or the like.

  For reference, a list of definitions of optical density for the black dye solution solid printing part is shown below.

ODdy (0): Black dye solution solid printing part Y color component initial (before test) optical density ODdm (0): Black dye solution solid printing part M color component initial (before test) optical density ODdc (0): Black Dye solution solid printing part C color component initial (before test) optical density ODdmax (0): Black dye solution solid printing part initial (before test) maximum optical density ODdy (1): Black dye solution solid printing part Y color component Optical density after test ODdm (1): Black dye solution solid print part M color component after test Optical density ODdc (1): Black dye solution solid print part C color component post test optical density ΔODdy: Black dye solution solid print Optical density difference before and after part Y color component test ΔODdm: Black dye solution solid printing part Optical density difference before and after M color component test ΔODdc: Black dye solution solid printing part Optical density difference before and after test ΔODdmax: Black Maximum optical density difference of solid printing part of dye solution

  In the present invention, if the content of the black dye is too small, even if the total content of the black dye and the toning color dye is a preferable content in the black ink for inkjet recording, a solid image having a sufficient optical density can be obtained. Since formation becomes difficult, it is preferably 50% by weight or more based on the total content of the black dye and the toning color dye.

  As the toning color dye, when the optical density of the C color component of the black dye is the highest and conversely the optical density of the Y color component is the lowest, it is preferably a yellow dye, and in some cases, a magenta dye can be used. . Moreover, both can also be used together. Depending on the black dye, the optical density of the C color component may be relatively low. In such a case, a cyan dye can be used as the toning color dye. Further, when the photobleaching of the black dye itself is severe, a yellow dye, a magenta dye, and a cyan dye can be used at the same time.

  In the present invention, the optical density reduction rate Aiy of the Y color component after the light resistance test and the optical density reduction of the M color component before the light resistance test defined by the following formulas (6) to (8) in the black ink solid print portion Both the rate Aim and the optical density reduction rate Aic of the C color component are preferably 20% or less, more preferably 15% or less. An optical density reduction rate of each color component of 20% or less means that each color component exhibits good light resistance, and a good color balance before the light resistance test is obtained. It becomes possible to maintain almost as it is later.

  For reference, a list of definitions related to the optical density reduction rate is shown below.

Aiy: Reduction rate of optical density of Y color component after light resistance test (%)
Aim: Optical density decrease rate of M color component after light resistance test (%)
Aic: Reduction rate of optical density of C color component after light resistance test (%)

  The black dye that can be used in the present invention was measured with a spectrophotometer (for example, UV-3600 manufactured by Shimadzu Corporation), and the absorbance of the dye aqueous solution was measured over the entire wavelength range of 380 to 650 nm. In this case, as shown in FIG. 2, it means a dye whose minimum absorbance is 25% or more of the maximum absorbance (maximum peak). In this case, the dye concentration of the aqueous dye solution is preferably such that the maximum absorbance is 0.50 to 1.50.

Examples of such a black dye include the following general formula (Bk-0), C.I. I. Acid Black 2, 7, 24, 26, 31, 52, 63, 112 and 118 etc .; C.I. I. Direct black 17, 19, 32, 51, 71, 108, 146, 154 and 168, etc .; I. B. Basic Black 2; I. Food black 1 and 2; etc. can be preferably used.

  In general formula (Bk-0), A and D each independently represent a phenyl group or a naphthyl group that may be substituted, and B and C each independently represent a naphthyl group that may be substituted. Each component of A, B, C and D contains at least one sulfo group, and one of X and Y represents a hydroxyl group and the other represents an amino group. M represents a hydrogen atom, an alkali metal, an organic amine cation or an ammonium ion. Here, among the black dyes represented by the general formula (Bk-0), the black dyes represented by the chemical formula (Bk-1) and the chemical formula (Bk-2) are particularly preferable because the decrease rate of the optical density is small. It can be preferably used.

  Examples of toning color dyes that can be used in the present invention include C.I. I. Direct yellow 12, 24, 26, 27, 28, 33, 39, 58, 86, 98, 100, 132, 142 and 169; I. Acid Yellow 3, 11, 17, 19, 23, 25, 29, 38, 42, 49, 59, 61, 71 and 72; I. B. Basic Yellow 40; I. Yellow dyes such as reactive yellow 2; the following general formula (M-0), general formula (M-00), C.I. I. Direct red 4, 17, 28, 37, 63, 75, 79, 80, 81, 83 and 254; I. Acid Red 1, 6, 8, 18, 32, 35, 37, 42, 52, 85, 88, 115, 133, 134, 154, 186, 249, 289 and 407; I. B. Basic Red 9, 12, and 13; I. And magenta dyes represented by Reactive Red 4, 23, 24, 31 and 56; In addition, C.I. I. Direct Blue 1, 6, 8, 15, 22, 25, 71, 76, 80, 86, 87, 90, 106, 108, 123, 163, 165, 199 and 226; I. Acid Blue 9, 22, 29, 40, 59, 62, 93, 102, 104, 112, 113, 117, 120, 167, 175, 183, 229 and 234; I. B. Basic Blue 1, 3, 5, 7, 9, 24, 25, 26, 28 and 29; I. Cyan dyes such as Reactive Blue 7, 13, and 49; can also be used.

In General Formula (M-0), R ₁ represents a hydrogen atom, an optionally substituted alkyl group, or an optionally substituted aryl group. R ₂ represents a hydrogen atom, a halogen atom or a cyano group. R ₃ represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aryl group or an optionally substituted heterocyclic group. R ₄ , R ₅ , R ₆ and R ₇ are each independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aryl group, an optionally substituted heterocyclic group, or optionally substituted. Represents a sulfonyl group or an optionally substituted acyl group. However, R ₄ and R ₅ are not both hydrogen atoms, and R ₆ and R ₇ are not both hydrogen atoms. Each of A ₁ and A ₂ is a carbon atom that may be substituted, or one of these is a carbon atom that may be substituted, and the other is a nitrogen atom.

In general formula (M-00), R ₈ , R ₉ and R ₁₀ are each independently an alkyl group that may be substituted, an alkoxy group that may be substituted, a halogen atom, a hydrogen atom, a hydroxyl group, or a substituted group. Carbamoyl group which may be substituted, sulfamoyl group which may be substituted, amino group which may be substituted, nitro group, sulfonate group, alkylsulfonyl group which may be substituted, arylsulfonyl group which may be substituted, carboxyl Represents a group or a group of a carboxylic acid ester. m represents a number of 0, 1 or 2, and R ₁₁ , R ₁₂ and R ₁₃ are each independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group or an optionally substituted group. An aryl group, an aralkyl group which may be substituted, an alicyclic group which may be substituted or a heterocyclic group which may be substituted is represented.

  Here, among the magenta dyes represented by the general formula (M-0) and the general formula (M-00), the chemical density (M-1) to the chemical formula (M-7) are preferable because the optical density reduction rate is small. A magenta dye represented by the formula can be particularly preferably used.

  The dye black ink for inkjet recording of the present invention contains water and a water-soluble organic solvent as a solvent in addition to the black dye and the toning color dye.

  As water, it is preferable to use deionized water. The water content is determined in a wide range according to the type and composition of the water-soluble organic solvent and the desired ink properties, but is generally 10 to 95% by weight with respect to the total amount of the dye black ink for inkjet recording of the present invention. , Preferably 10 to 80% by weight, more preferably 20 to 80% by weight.

  Water-soluble organic solvents are mainly classified into a wetting agent having an effect of preventing ink drying at the tip of the inkjet head and a penetrating agent that increases the drying speed on the paper surface. The wetting agent is not particularly limited, and examples thereof include lower alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol; dimethylformamide, dimethylacetamide, and the like. Amides; ketones or keto alcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; polyalkylene glycols such as polyethylene glycol and polypropylene glycol; ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol, dipropylene Alkylene glycol such as glycol, tripropylene glycol, thiodiglycol, hexylene glycol And 1,3-dimethyl-2-imidazolidinone; Lumpur; glycerin; 2-pyrrolidone; N- methyl-2-pyrrolidone. Of these, polyhydric alcohols such as alkylene glycol and glycerin are preferable.

  The content of the wetting agent is generally 0 to 95% by weight, preferably 5 to 80% by weight, more preferably 5 to 50% by weight, based on the total amount of the dye black ink for inkjet recording of the present invention.

  The penetrant is not particularly limited. For example, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol propyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol propyl ether, diethylene glycol butyl ether, triethylene glycol methyl ether, triethylene glycol Ethyl ether, triethylene glycol propyl ether, triethylene glycol butyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol propyl ether, propylene glycol butyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether, di B propylene glycol propyl ether, dipropylene glycol butyl ether, tripropylene glycol methyl ether, tripropylene glycol ethyl ether, tripropylene glycol propyl ether, and glycol ethers such as tripropylene glycol butyl ether.

  If the content of the penetrant is excessive, the penetrability of the ink into the paper becomes too high and may cause bleeding. On the other hand, it is generally 0 to 20% by weight, preferably 0.1 to 15% by weight, more preferably 0.2 to 10% by weight.

  The ink-jet recording dye black ink of the present invention may further include, as necessary, conventionally known additions such as a viscosity adjusting agent such as polyvinyl alcohol, polyvinyl pyrrolidone, and a water-soluble resin; a surface tension adjusting agent; an antifungal agent; An agent may be contained.

  The ink-jet recording dye black ink of the present invention is obtained by uniformly mixing a black dye and a toning color dye with other additive components such as water and a water-soluble organic solvent, and removing insoluble matter with a filter. Can be prepared.

  The dye black ink for ink-jet recording of the present invention can be used for ink-jet recording by filling an ink cartridge of a conventionally known ink-jet printer.

1) Preparation of black ink and black dye solution 1-1) Examples 1-7 and Comparative Examples 1-6
After mixing and stirring the ink composition of Table 1, Examples 1 to 7 and Comparative Example 1 were performed by filtering with a hydrophilic PTFE (polytetrafluoroethylene) type membrane filter (pore diameter 0.2 μm) manufactured by Toyo Roshi Kaisha, Ltd. A dyed black ink for inkjet recording having a toned color of 6 to 6 was obtained. In the ink composition of Table 1, black dyes (Bk-1) and (Bk-2) are compounds represented by chemical formulas (Bk-1) and (Bk-2), respectively, and a magenta dye (M-1). -(M-7) are compounds represented by chemical formulas (M-1)-(M-7), respectively.

1-2) Black dye solutions 1-6
Black dye solutions 1 to 6 having the black dye solution composition shown in Table 2 were obtained in the same manner as in Examples and Comparative Examples except that 3.0% by weight of black dye was used and no toning color dye was used. It was. However, the increase / decrease blending amount of the black dye and the blending amount of the toning color dye not used were replaced with water. In the black dye solution composition in Table 2, black dyes (Bk-1) and (Bk-2) are compounds represented by chemical formulas (Bk-1) and (Bk-2), respectively.

2) Evaluation sample printing The black ink and the black dye solution prepared in 1) above were filled in an ink cartridge and mounted on a digital multifunction printer DCP-115C equipped with an inkjet printer manufactured by Brother Industries, Ltd., Brother Industries, Ltd. A 16-tone gradation sample (black to gray to white) was solid-printed on photographic glossy paper BP61GLA.

3) Black ink evaluation 3-1) Measurement of optical density of each color component before light resistance test Average optical density of Y color component, M color component and C color component from the evaluation sample (gradation sample) printed in 2) above A black ink solid print portion having a density of 0.9 or more and 1.1 or less is selected as an evaluation sample, and is divided into a Y color component, an M color component, and a C color component (initially before test) optical density (ODiy (0), ODim ( 0) and ODic (0)) were measured using Spectrolino (light source: D ₆₅ , viewing angle: 2 °, status A) manufactured by Gretag Macbeth. The obtained results are shown in Table 3.

Further, ODimax (0) and ODimin (0) were identified from the initial (before test) optical densities of the Y color component, M color component, and C color component, and evaluated according to the following evaluation criteria. The obtained results are shown in Table 3.
A: ODimax (0) −ODimin (0) ≦ 0.15
B: 0.15 <ODimax (0) −ODimin (0) ≦ 0.20
C: 0.20 <ODimax (0) −ODimin (0)

3-2) Optical density measurement of each color component after light resistance test The light resistance test for the evaluation sample used in the above 3-1) using a high energy xenon weather meter SC780-WN manufactured by Suga Test Instruments Co., Ltd. Was given. Specifically, in an environment of a temperature of 25 ° C. and a humidity of 50% RH, light emitted from a xenon lamp is converted into a light source lamp filter made of quartz glass, an inner filter made of quartz glass, and a glass that cuts light having a wavelength of 320 nm or less. After passing through the outer filter made of, the illuminance 93kl to the evaluation sample
Irradiated with ux for 100 hours. After the light resistance test, the post-test optical density (ODiy (1), ODim (1) and ODic (1)) divided into Y color component, M color component and C color component is measured by Gretag Macbet.
Measurement was performed using Spectrolino (light source: D ₆₅ , viewing angle: 2 °, status A) manufactured by h company. The obtained results are shown in Table 3.

Further, from the post-test optical densities of the Y color component, the M color component, and the C color component, ODimax (1) and ODimi
n (1) was identified and evaluated according to the following evaluation criteria. The obtained results are shown in Table 3.
A: ODimax (1) −ODimin (1) ≦ 0.15
B: 0.15 <ODimax (1) −ODimin (1) ≦ 0.20
C: 0.20 <ODimax (1) −ODimin (1)

3-3) Reduction rate of optical density of each color component after light resistance test From the initial (before test) optical density in 3-1) and the optical density after test in 3-2) above, Y color component, M color component and C The optical density reduction rate (Aiy, Aim and Aic) of the color component was determined. The obtained results are shown in Table 3.

3-4) Overall Evaluation The black inks of Examples 1 to 7 and Comparative Examples 1 to 7 were evaluated according to the following evaluation criteria. The obtained results are shown in Table 3.
Excellent: The above evaluations of 3-1) and 3-2) are both A, and all of Aiy, Aim, and Aic are 15% or less.
Very Good: Both the above evaluations of 3-1) and 3-2) are A, and all of Aiy, Aim, and Aic are over 15% and 20% or less.
Good: Although the above evaluations of 3-1) and 3-2) are both A, Aiy, Aim and Aic
Either exceeds 20%
Not Good: Any of the evaluations in the above 3-1) and 3-2) is B or C

4) Black dye solution evaluation 4-1) Optical density measurement of each color component before light fastness test From the evaluation sample (gradation sample) printed in the above 2), any one of Y color component, M color component and C color component A black dye solution solid print portion having an optical density of 0.9 to 1.1 and the highest color component among them is selected as an evaluation sample, and the Y color component, M color component, and C color are selected. The initial (before test) optical density (ODdy (0), ODdm (0), and ODdc (0)) divided into components was used using Spectrolino (light source: D ₆₅ , viewing angle: 2 °, status A) manufactured by Gretag Macbeth. Measured. The obtained results are shown in Table 2.

4-2) Optical density measurement of each color component after light resistance test The light resistance test is performed on the evaluation sample used in the above 4-1) using a high energy xenon weather meter SC780-WN manufactured by Suga Test Instruments Co., Ltd. Was given. Specifically, in an environment of a temperature of 25 ° C. and a humidity of 50% RH, light emitted from a xenon lamp is converted into a light source lamp filter made of quartz glass, an inner filter made of quartz glass, and a glass that cuts light having a wavelength of 320 nm or less. After passing the manufactured outer filter, the evaluation sample was irradiated with an illuminance of 93 klux for 100 hours. After the light resistance test, the optical density (ODdy (1), ODdm (1) and ODdc (1)) divided into Y color component, M color component and C color component is measured by Spectrolino (light source: D ₆₅ ) manufactured by Gretag Macbeth. , Viewing angle: 2 °, status A). The obtained results are shown in Table 2.

4-3) Difference in optical density of each color component before and after light resistance test From the initial (before test) optical density in 4-1) and the post-test optical density in 4-2) above, Y color component, M color component and C color The optical density differences (ΔODdy, ΔODdm, and ΔODdc) of the components were determined. The obtained results are shown in Table 2.

(Discussion)
In Examples 1 to 7 and Comparative Examples 1 to 6, since the color component having the maximum optical density (OD value) in the used black dye is a C color component, a yellow dye and a magenta dye are used as toning color dyes. In combination with a black dye.

  In the case of Examples 1 and 2, since the difference between the maximum optical density and the minimum optical density in each color component is 0.15 or less both before and after the light resistance test of the evaluation sample, before and after the light resistance test. Later color balance was good. Furthermore, the OD reduction rates of the respective color components in the light resistance test were all 15% or less, and the light resistance was very good.

  In the case of Examples 3 and 4, since the difference between the maximum optical density and the minimum optical density in each color component is 0.15 or less both before and after the light resistance test of the evaluation sample, before and after the light resistance test. Later color balance was good. However, although the OD reduction rate of each cyan color component in the light resistance test slightly exceeded 15%, the light resistance was reduced as compared with Examples 1 and 2, but there was no practical problem.

  In the case of Examples 5 to 7, the difference between the maximum optical density and the minimum optical density in each color component is 0.15 or less both before and after the light resistance test of the evaluation sample. Later color balance was good. Note that the OD reduction rate of each color component in the light resistance test greatly exceeded 15% except for the Y color component of Example 7, so that the light resistance was as compared with the cases of Examples 1 and 2. However, as described above, there was no practical problem as far as color balance was concerned.

  In the case of Comparative Example 1, since the difference between the maximum optical density and the minimum optical density in each color component before the light resistance test of the evaluation sample is 0.15 or less, the color balance before the light resistance test was good. It was. However, after the light resistance test, the optical density of the Y color component and the C color component is greatly reduced, and the difference between the maximum optical density and the minimum optical density exceeds 0.15, so there is a problem in the color balance after the light resistance test. was there.

  In the case of Comparative Example 2, the difference between the maximum optical density and the minimum optical density in each color component before the light resistance test of the evaluation sample exceeds 0.15, and further the difference after the light resistance test is also 0.15. Since it greatly exceeded, there was a problem in color balance both before and after the light resistance test.

  In Comparative Examples 3 and 4, the difference between the maximum optical density and the minimum optical density in each color component before the light resistance test of the evaluation sample was 0.15 or less, but the maximum optical density after the light resistance test was Since the difference between the density and the minimum optical density exceeded 0.15, there was a problem in the color balance after the light resistance test.

  In the case of Comparative Example 5, the difference between the maximum optical density and the minimum optical density in each color component before the light resistance test of the evaluation sample exceeded 0.15, so there was a problem in the color balance before the light resistance test. It was.

  In the case of Comparative Example 6, since the difference between the maximum optical density and the minimum optical density in each color component before the light resistance test of the evaluation sample was 0.15 or less, the color balance before the light resistance test was good. However, it exceeded 0.15 after the light resistance test, and there was a problem in color balance after the light resistance test.

  The toned dye-based black ink for ink-jet recording of the present invention can achieve a good color balance before and after fading with light on a printed matter obtained therefrom. Therefore, it is possible to provide a printed matter that does not stand out from light fading, and is useful as a dye-based black ink for ink jet recording.

FIG. 1A is an optical density diagram of each color component of a black dye solution solid print by a black dye solution using only a single black dye, and FIG. 1B is a yellow dye and magenta as toning color dyes. FIG. 1C is an optical density diagram of each color component of a black ink solid print with a black ink using a dye in combination with a black dye. FIG. 1C is a black ink using a yellow dye and a magenta dye as a toning color dye in combination with a black dye. It is explanatory drawing of the optical density of each color component after the light resistance test of a black ink solid printed matter. It is an absorbance curve diagram of black dye. It is explanatory drawing of the optical density of each color component of the black ink solid printed matter by the dye black ink for inkjet recording using only single black dye. It is explanatory drawing of the optical density of each color component of a solid printed matter when yellow dye and magenta dye which are toning color dyes are used together with black dye.

Claims (8)

A black ink, a toning color dye, a water-soluble organic solvent and water-containing dye black ink for ink-jet recording,
For black ink solid print portions with an average optical density of 0.9 or more and 1.1 or less printed on glossy paper using black ink, the optical density of the yellow color component is ODiy (0), and the optical density of the magenta color component is ODim ( 0), the optical density of the cyan component is ODic (0), the maximum optical density of ODiy (0), ODim (0), and ODic (0) is ODimax (0), and the minimum optical density is ODimin (0). ,
A predetermined light resistance test is performed on the black ink solid print portion, and the optical density of the yellow color component after the test is ODiy (1), the optical density of the magenta color component is ODim (1), and the optical density of the cyan color component is ODic ( 1), and when the maximum optical density is defined as ODimax (1) and the minimum optical density is defined as ODimin (1) among ODiy (1), ODim (1) and ODic (1), the following formula (1) and (2) A dye black ink for ink jet recording characterized by satisfying simultaneously.

The black dye is
Black dye solution solid print part printed on glossy paper using black dye, which is a constituent of black ink, water-soluble organic solvent and water, which is a component of black ink for inkjet recording, excluding toning color ink, yellow The optical density of the color component is ODdy (0), the optical density of the magenta color component is ODdm (0), the optical density of the cyan component is ODdc (0), and ODdy (0), ODdm (0), and ODdc (0). The maximum optical density is ODdmax (0),
A predetermined light resistance test is performed on the black dye solution solid print part, and the optical density of the yellow color component after the test is ODdy (1), the optical density of the magenta color component is ODdm (1), and the optical density of the cyan color component is When ODdc (1) is defined and the maximum optical density difference is defined as ΔODdmax among ΔODdy, ΔODdm, and ΔODdc defined by the following equations (3) to (5),
2. The dye ink for ink-jet recording according to claim 1, wherein the color component exhibiting ΔODdmax is a black dye constituting a black dye solution that matches the color component exhibiting ODdmax (0).

  The dye black ink for ink jet recording according to claim 2, wherein the color component exhibiting ΔODdmax is a cyan color component.   The dye black ink for inkjet recording according to any one of claims 1 to 3, wherein the black dye is contained in an amount of 50% by weight or more based on the total content of the black dye and the toning color dye.   The ink-jet recording dye black ink according to any one of claims 1 to 4, wherein the toning color dye is a yellow dye.   The black ink for inkjet recording according to any one of claims 1 to 4, wherein the toning color dye is a magenta dye.   The dye black ink for inkjet recording according to any one of claims 1 to 4, wherein the toning color dye is a yellow dye and a magenta dye. The dye black ink for inkjet recording according to any one of claims 1 to 7, wherein Aiy, Aim and Aic defined by the following formulas (6) to (8) are all 20% or less.

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