JPH111645A - Recording fluid and recording process - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a recording fluid which can give recorded images having vivid colors and reduced in blotting at the boundary of colors and has good stability in long-term storage by including a water-soluble colorant specified from a spectrum pattern of proton nuclear magnetic resonance(NMR) at 400 MHz and an aqueous medium. SOLUTION: A water-soluble colorant having at least one peak having a half-width of 0.1 ppm or above in a spectrum pattern of NMR is selected. The colorant has no particular limitations on its skeletal structure and may be one selected among azoic, triphenylmethane and fused polycyclic compounds, etc., and it is particularly desirably one having 1-4 azo groups. Further, when the hue of the colorant is Magenta, Yellow or Cyan, the image quality can be further improved. To dissolve the colorant in an aqueous medium, the water- soluble colorant is dissolved in highly pure water, the solution is optionally decontaminated by e.g. treatment with an ion exchange resin, a water-soluble organic solvent such as ethylene glycol is added to the solution, and the resultant solution is passed through a precision filter membrane having a pore diameter of 1-0.2 μm. The colorant concentration is 0.5-7 wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording liquid and a recording method using the same. More specifically, the present invention relates to a recording liquid suitable for ink jet recording and a recording method using the same.

[0002]

2. Description of the Related Art Droplets of a recording liquid containing a water-soluble dye represented by a direct dye or an acid dye or a pigment represented by a carbon black as a coloring agent in an aqueous medium are caused to fly from a fine discharge orifice. A so-called ink jet recording method for performing recording by using a recording medium has been put to practical use. Various types of recording liquid, such as plain paper generally used for general office work such as electrophotographic paper, special paper (dedicated paper) used for a specific purpose such as digital photographic image recording, postcards, stationery paper, and cloth, are used for this recording liquid. Fastness and good print quality of printed matter, that is, image quality deterioration (hereinafter abbreviated as “feathering”) due to dot thickening due to spread of ink on the surface of the recording medium. It is required to have a clear outline and a vivid color tone without bleeding (hereinafter, abbreviated as "color boundary bleeding") and blurring at a color overlapping portion or a boundary portion of each color in color printing. Further, it must be excellent in storage stability as a recording liquid and capable of stable ejection and recording for a long period of time.

Further, since it is necessary that the recording liquid or the recorded image does not cause any health problem even if it touches the human body, the solvent which can be used for the recording liquid is remarkably limited, and mainly water or a necessary minimum amount of water is used. Water containing a volatile organic solvent is used. With the development of ink jet printers capable of supporting high image quality close to color printing, especially silver halide photography, and their widespread use in general households, the demand for stable ejection performance, safety, and clear image quality has further increased. It is getting.

On the other hand, recording dyes have sufficient solubility or dispersibility in the above-mentioned limited solvents and are stable even when stored as recording liquids for a long time. Must be given over a long period of time. In addition, the above-mentioned various properties, that is, print quality largely depend on the performance of the dye. Therefore, the dye is required to have high image density and marker resistance when printed, to have no feathering or color boundary bleeding, and to have a vivid color tone. However, it has been difficult to satisfy many of these requirements simultaneously.

For example, C.I. I. Pigment Yellow 4,
C. I. Pigment Red 122, C.I. I. Many recording liquids in which a pigment that is hardly soluble or insoluble in water, such as Pigment Blue 16 or carbon black, is dispersed have been reported. Above all, Japanese Patent Application Laid-Open No. 7-173419 and the like exemplify research results particularly concerning improvement in print quality of pigment-based ink. It is said that some pigment-based recording liquids, including those reported examples, are good for specific items of print quality, such as feathering resistance, color boundary bleeding resistance, and water resistance. On the other hand, pigment-based recording liquids often have insufficient long-term storage stability due to low solubility in water,
Precipitation is generated due to dispersion destruction and clogging of the discharge nozzle, etc., faint printing may occur or printing may not be possible in the worst case, so it is difficult to say that good printing quality is stably given. Have been. As reported in JP-A-1-282273, etc., the prevention of solidification of the recording liquid at the head end and the stability have been somewhat improved, but its reliability cannot surpass that of the water-soluble dye. Investigation examples of the combination use of a sex dye have also been reported. Further, pigments are inferior to water-soluble dyes in terms of hue brightness. It is hard to say that sufficient performance is expected as a recording liquid, and as a result, water-soluble dyes are used instead of pigments in most of commercially available ink jet recording liquids.

On the other hand, most of recording liquids containing a water-soluble dye as a dye are excellent in long-term storage stability and ejection stability and give a vivid color tone. When the rate of permeation drying was increased, the moving speed of the dye on the surface of the recording material was also increased, and feathering became conspicuous. Therefore, as described in, for example, JP-A-62-161872, various additives are added to a water-soluble dye-containing recording liquid to improve the print quality such as bleeding property and to achieve compatibility with a clear hue. However, the results have not yet been sufficiently satisfied. JP-A-6-157856 or JP-A-6-228475 reports an example in which conditions such as the amount of ink permeation into a specific paper are strictly defined to improve the print quality. On the other hand, Japanese Patent Publication No. 5-17866 and the like also introduce the use of specific recording paper whose surface has been treated and modified with various chemicals to improve print quality, and some of these techniques have been put to practical use. However, recording devices using the principle of ink-jet recording have spread rapidly and widely to small offices and ordinary homes, and the diversification of ink-jet recording principles, recording mechanisms, and recording media has been remarkably progressing. The examples have not been able to sufficiently answer the various demands required of the ink jet recording apparatus.

[0007]

SUMMARY OF THE INVENTION The present invention is intended mainly for use in ink jet recording, in which the recording quality is good even when recording on a recording medium other than special paper, the density of the recorded image is high, and storage is performed for a long time. It is an object of the present invention to provide a recording liquid and a recording method which have good stability.

[0008]

Means for Solving the Problems The present inventors have confirmed that the performance satisfying the above object can be obtained when a recording liquid containing a dye having a certain characteristic is used, and achieved the object of the present invention. It was done. That is, the gist of the first invention of the present application is:
A recording liquid characterized by containing at least a water-soluble dye having one or more peaks having a half width of 0.1 ppm or more in a 400 MHz proton nuclear magnetic resonance analysis spectrum diagram, and an aqueous medium. Further, the gist of the second invention of the present application is an ink jet recording method using the above recording liquid.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
Although the water-soluble dye used in the present invention has no structural limitation, it uses sodium 3-trimethylsilylpropionate-2,2,3,3-d4 (hereinafter abbreviated as “TSP”) as a reference substance in heavy water. 40 measured at room temperature
In the spectrum diagram of 0 MHz proton nuclear magnetic resonance (hereinafter abbreviated as “NMR”), the half width is 0.1 ppm.
As described above, usually, 0.1 to 1.0 ppm, especially 0.10 to
When a water-soluble dye having one or more peaks (hereinafter, abbreviated as “broad peak”) of about 0.4 ppm is selected, and a recording liquid is adjusted using the selected dye, and ink jet recording is performed, a boundary between other colors is obtained. And a beautiful recorded image having a hue of high purity inherent to a water-soluble dye can be obtained while preventing bleeding. In addition, in this case, the high storage and ejection stability inherent in the water-soluble dye-based recording liquid can be simultaneously achieved.

The NMR peaks are described in detail in, for example, " ¹ H and ¹³ C NMR Overview" issued by Kagaku Dojin, translated by Takahito Takeuchi, etc., for the purpose of clarifying the present invention. This will be described below. 4 in the present invention
In the 00 MHz proton NMR spectrum, as will be described later, as long as the analysis conditions such as the measurement temperature, the concentration and dissolution state of the sample to be measured, and the purity of the sample are appropriately set, protons in different environments on the dye are spectrum diagrams, respectively. It appears as a peak having a unique splitting pattern at different positions above, and the peak intensity ratio, that is, the peak area ratio is proportional to the number of protons that caused the peak. Here, the unique position on the spectrum diagram is defined as a chemical shift using TSP, tetramethylsilane, or the like used as a reference substance in the present invention, and is expressed in units of ppm. It is common to take a value. Here, the different environment is, for example, the type of the atom to which the proton is bonded, the type of the atom or the substituent to which the atom is bonded, and whether or not the proton is hydrogen-bonded.

The splitting of the peak is a phenomenon called “coupling”. The coupled proton generally gives an aggregated peak composed of several sharp splitting peaks having a half width of less than 0.1 ppm, and the splitting depth is usually
It is about 10% to 95% of the aggregate peak height. Further, the number of the splits is unique to the environment of each proton, and the shape, the number, or the position of the peak can be inferred from information described in the literature. Noise derived from device accuracy or the like only gives miscellaneous small splits independent of the environment of the proton. On the other hand, protons which are not coupled because the adjacent group has no hydrogen give not a splitting peak but a single peak. In this case, too, a sharp peak having a half width of less than 0.1 ppm is usually obtained.

Here, protons in very similar environments appear on the spectrum diagram in a very close or overlapping manner, but even in this case, as long as each proton is coupled, the peak Near the top, a split with a depth of about 10 to 50% of the peak height is observed. For the half-value width of the split peak, a perpendicular line to the baseline of the spectrum is drawn from the valley of each split, and the peak aggregate is separated on the chart as each split peak. If the peak width of the half part is measured, the half width of the peak can be obtained.

Regarding the NMR peak in the present invention, each of the above-mentioned split peaks is counted as one peak. That is, those which are clearly observed as one peak on the NMP spectrum diagram are counted as one peak. On the other hand, for example, when a splitting peak due to coupling such as a doublet and a triplet is clearly observed, or a seemingly wide peak having jagged irregularities near the top as a result of their aggregation, the splitting valley portion with respect to the baseline. By drawing a perpendicular line, a seemingly broad peak is separated as each splitting peak on the figure, and then each splitting peak is counted as one.

Here, whether or not the seemingly wide peak is an aggregate of sharp splitting peaks due to coupling is determined by the splitting at a depth of 10% or more of the height of the wide peak near the top of the wide peak. Judgment is made based on whether or not a valley derived from a peak can be observed. That is, even if the NMR peak appears to be wide at first glance, if a valley derived from a splitting peak having a depth of 10% or more of the broad peak height can be observed near the peak apex, a perpendicular line from the splitting valley portion to the baseline is obtained. Then, the apparently broad peak is separated as each splitting peak on the figure, and then each splitting peak is counted as one. On the other hand, in the case where a valley derived from a split peak having a depth of 10% or more of the broad peak height cannot be observed even with a wide peak, the entire wide peak is counted as one peak. In this way, the half width of each peak was measured, and it was 0.1 p.
If it is not less than pm, it is counted as a broad peak.

It is needless to say that irregularities on minute peaks determined to be unrelated to coupling have been ignored as noise. Further, water (H2
Of course, peaks derived from O) and the like should be neglected. As for proton NMR analysis, reproducible analysis is performed under the following conditions.

That is, the resonance frequency was 399.7 MHz using an α-400 Fourier transform nuclear magnetic resonance apparatus manufactured by JEOL Ltd.
z, measurement temperature 24-26 ° C, pulse width 9.00μsec
(90 °), wait time 7.0 sec, observation frequency 799
3.6Hz, number of data points 16384, number of integration 3
Performed 2, Reference material 3-tri acid sodium -2,2,3,3-d4 (TSP), reference substance concentration of 0.1%, sample concentration of 1.0%, analyzed by the solvent D ₂ O conditions .

Further, the broad peak has a chemical shift of 1
When a recording liquid containing one or more water-soluble dyes in an aqueous medium at any one of between 4 ppm and 7-9 ppm is used,
It was found that a beautiful recorded image having a hue of high purity inherent to a water-soluble dye was obtained while preventing bleeding. Also,
The ratio of the broad peak in the NMR chart of the dye is preferably 25% or more, more preferably 30 to 90%. In addition, the broad peaks have chemical shifts of 1-4p
It is particularly preferred that the ratio is at least 25%, especially 30 to 90%, between pm and 7 to 9 ppm.

The skeleton structure of the dye is not particularly limited as described above, and those having a specific NMR peak may be selected from azo, triphenylmethane, and condensed polycyclic compounds. Among them, those having one or more azo groups, among which the number of azo groups is preferably 1 to 4, are preferred. Incidentally, the specific water-soluble dye of the present invention,
As the basic skeleton, a required basic skeleton structure may be selected and synthesized according to the use of the recording liquid, and for example, when used for ink jet recording, good color tone and light fastness are obtained. As will be described later, a specific dye having a broad peak is selected as a result of undergoing a chemical treatment in the preparation process and a skeleton structure in which association is likely to occur. Although the details are not yet elucidated, azo dyes represented by direct dyes are used as the skeleton structure where association is likely to occur, and purity is improved by recrystallization etc. as chemical treatment, reverse osmosis membrane treatment Reduction of ion content.

Further, the color tone of the pigment is magenta, yellow,
It was found that the above-mentioned image quality was further improved with any of cyan and cyan. Further, as long as the effects of the present invention are achieved, a water-soluble dye other than the specific water-soluble dye may be used in combination. The recording liquid is adjusted as follows.

The water-soluble dye selected as described above is dissolved in an aqueous medium according to a conventional method. Specifically, for example, a water-soluble dye is dissolved in high-purity water to prepare an aqueous dye solution. If necessary, the aqueous solution may be subjected to an acid precipitation treatment, a recrystallization, a reverse osmosis membrane, or an ion exchange resin treatment to remove impurities such as inorganic salts and metals. Then, for example, ethylene glycol, diethylene glycol, propylene glycol, ethyl alcohol, isopropyl alcohol, 2-pyrrolidone, N
A water-soluble organic solvent such as -methyl-2-pyrrolidone, thiodiethanol, glycerin, and dimethyl sulfoxide is added to adjust the viscosity of the recording liquid and the rate of penetration into the recording paper. These water-soluble organic solvents are usually used in the range of 1 to 50% by weight based on the weight of the recording liquid. On the other hand, water is used in the range of 45 to 95% by weight based on the total amount of the recording liquid, and the dye concentration is usually set to about 0.5 to 7%. Further, if necessary, the solution prepared as described above, pore size 1 ~
By passing the solution through a microfiltration membrane such as 0.2 μm,
The fine insoluble matter is filtered off to obtain a recording liquid.

The recording liquid of the present invention is suitably used as an ink for ink jet recording. The method of inkjet recording is not particularly limited and can be used for any printing method.Aqueous recording liquid containing a pigment, among which, the rub fastness evaluated by the method described below is second class or higher, particularly, A method of performing print recording by using an aqueous recording liquid containing a pigment that gives a second to fourth grade printed image is particularly preferable since blurring at a color boundary is small and a beautiful image can be obtained. Examples of such a pigment include a carbon black type, an azo type and a condensed polycyclic type.

The rub fastness of a printed image is determined according to JIS L 0
It is measured according to the friction fastness test method described in 849.
That is, this test method uses a friction tester to attach a white cloth for friction test to a friction element to which a load of 200 g has been applied, and reciprocate it a specified number of times while making contact with the sample to determine the degree of coloring of the white cloth. . That is, the higher the degree of coloring of the white cloth, the lower the friction fastness of the sample. The evaluation of the friction fastness in the present application was performed by setting the number of times of friction by the friction element to 20 reciprocations. The test was performed 24 hours after printing. The degree of coloring of the white cloth is determined by using a gray scale, and is represented by a series of five grades from those having good friction fastness (grade 5) to those having poor friction fastness (grade 1). Further, when the fastness of the sample is located in the middle of each grade, it is displayed in an expression such as 1-2 grade.
This determination method is defined in JIS L0801.

The pigment content is usually 0.5 to 7
%. The water-soluble dye is as described above. In this case, the recording liquid containing the pigment and the recording liquid of the present invention may be printed and recorded at the same time, or a method of sequentially printing and recording may be used. Further, in the present invention, by further including a pigment as a coloring agent in the recording liquid, an image with less pigment bleeding can be obtained.

The pigment used in this case is not particularly limited, and carbon blacks, azos, condensed polycyclics and the like can be used. Among them, carbon blacks and azos are preferable. Incidentally, the recording liquid containing a pigment together with the water-soluble dye, when preparing the recording liquid containing the specific water-soluble dye of the present invention, it can be prepared by adding and dispersing the pigment, or in advance, Each of them may be contained in an aqueous medium and mixed and prepared. In this case, the content of the pigment is usually from 0.5 to
5%, preferably about 1 to 5%.

It is not clear why the dye giving one or more broad peaks on the NMR chart causes the above-mentioned useful phenomenon, despite the studies by the inventors.
However, it can be inferred that the broad peak indicates that the dye molecules associate and form a dimer or a multimer due to the interaction between the water-soluble dye molecules. Therefore, in the course of drying when the recording liquid penetrates the recording medium during recording, among the dyes characterized by the broad peak, the long-form dye containing an azo group readily associates and becomes It is presumed that by promoting the formation of a polymer or a multimer, resistance to undesired dye migration on the recording medium such as feathering and color boundary bleeding is exhibited. When the water-soluble dye behaves like high-molecular-weight particles when the recording solution is dried for recording, the dye migration resistance is high, and the pigment recording solution, in particular, the interaction between the pigment particles is strong. It is thought that it appears synergistically when used in combination with the recording liquid.

[0026]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the examples. Parts in the text indicate parts by weight. (Proton NMR analysis) Resonance frequency 399.7M using α-400 Fourier transform nuclear magnetic resonance apparatus manufactured by JEOL Ltd.
Hz, measurement temperature 24-26 ° C, pulse width 9.00 μs
c (90 °), waiting time 7.0 sec, observation frequency 79
93.6 Hz, number of data points 16384, number of integration 32, reference substance 3-sodium trimethylsilylpropionate-2, 2, 3, 3-d4, reference substance concentration 0.1
%, The sample concentration was 1.0%, and the solvent was D ₂ O.

(Image quality) A commercially available ink jet printer, desk writer 660C is used for ink jet recording.
(Manufactured by Hewlett-Packard Co.). Paper 4024 (manufactured by Xerox Corporation) was used as the recording material. As a result, a solid image was printed as described later, and the resulting image was observed particularly at the different color boundary portion, and the image quality was evaluated based on the following criteria. The evaluation was performed 30 minutes after printing. ◎ ・ ・ ・ Image in which color boundary bleeding is hardly recognized even when viewed from a distance of 30 cm ○ ・ ・ ・ Color boundary bleeding is recognized when viewed from a distance of 30 cm, but color boundary bleeding is hardly recognized when viewed from a distance of 60 cm Unrecognizable image × ・ ・ ・ Image observed from a distance of 60 cm and color boundary blur can be clearly recognized.

(Fastness of Friction) The rubfastness of an image was measured using a printer which is used in the above-described image quality evaluation and which was solid-printed in a normal mode using a sample as a sample according to the rubfastness test method defined in JIS L0849. The evaluation was performed according to the method of the drying test. However, the number of times of friction was 20 times.
The test was performed 24 hours after printing. Judgment is JIS
Performed according to L0801.

Example 1 While maintaining an aqueous solution of 1-amino-8-hydroxy-3,6-naphthalenedisulfonic acid (H acid) at 3 ° C., a cyanuric chloride suspension was added and reacted for 8 hours. Then, 0.5 mol ratio of 1,3 bispiperidylpropane to cyanuric chloride was added while maintaining pH 6 to 7, and a condensation reaction was carried out for 8 hours. From the obtained condensation reaction product and 2-aminobenzoic acid, a conventional method (Yoshi Hosoda, “New Dye Chemistry” (December 2, 1973)
An azo compound was produced in accordance with (1st day, published by Gihodo) pp. 396-409). Then, the pH of the system was adjusted to 13.5 with a 25% aqueous sodium hydroxide solution, a hydrolysis reaction was performed at 55 ° C., the pH was adjusted to 9 with 35% hydrochloric acid, and the mixture was cooled. After salting out, the cake was collected by filtration and dried.

[0030]

Embedded image

A magenta dye was obtained. N of the obtained dye
The MR chart is as shown in FIG. 1, and as shown in Table 1, it was found to have a total of 11 broad peaks. 5 parts of the obtained dye was dissolved in 100 parts of ion-exchanged water, and after adjusting the pH to 1 or less with 35% hydrochloric acid, the resulting dye precipitate was collected by filtration. Further, ion-exchanged water and a 25% aqueous sodium hydroxide solution were added thereto to obtain a dye solution having a pH of 9 and a total weight of 130 parts. After adding 15 parts of diethylene glycol and 5 parts of isopropyl alcohol, the mixture was sufficiently stirred, filtered under pressure through a microfiltration membrane having a pore diameter of 0.2 μm, and then deaerated with a vacuum pump and an ultrasonic cleaner to prepare a recording liquid. did.

Using the obtained magenta recording liquid and a genuine yellow dye recording liquid of a printer, a two-color solid image was printed. As a result, the obtained image was a beautiful image having a clear color tone in both the yellow and magenta portions and almost no red bleeding into the yellow portion. The results are shown in Table 2. After the recording liquid was stored at 30 ° C. for 90 days after the printing test, the same printing test was performed again. However, the image quality did not change, and undesired phenomena such as sedimentation of the dye or clogging at the inkjet nozzle portion due to the dye were observed. It was found that the recording liquid did not occur, and the storage stability of the recording liquid was also confirmed.

Example 2 (combined use of pigment-based recording liquid) 2 parts of 2-pyrrolidone, 3 parts of N-methyl-2-pyrrolidone, 3 parts of glycerin, and 5 parts of isopropyl alcohol
Section, carbon black MA600 (Mitsubishi Chemical Corporation)
5 parts) and 3 parts (solid content) of Polystar S2-1020 (styrene / maleate copolymer, manufactured by Nippon Oil & Fats) in a stainless steel container, and add ion-exchanged water to make a total amount. Make 44 copies. This was crushed together with 67 parts of glass beads (GB200M manufactured by Toshiba Barotini) having an average diameter of 0.5 mm for 60 hours using a sand grinder. After diluting the obtained liquid with 56 parts of ion-exchanged water and stirring, Pressure filtration was performed using a 5C filter paper, and the liquid obtained here was used as a recording liquid.

Using the thus obtained recording liquid and the magenta recording liquid described in Example 1, a two-color solid image was printed.
As a result, a very beautiful image with almost no bleeding on the two-color boundary line was obtained. When the rub fastness of the solid black portion was evaluated, a result of second class was obtained. The results are shown in Table 2. Further, a storage stability test of the recording liquid was performed by the method described in Example 1. However, there was no problem as in Example 1.

Example 3 The same experiment as in Example 2 was conducted, except that a genuine pigment-based black recording liquid for a printer was used in place of the black recording liquid used in Example 2. The resulting image was relatively beautiful, although some bleeding was observed at the black and red borders. It was 1 when the rub fastness of the black solid portion was evaluated.
It was found that the black recording liquid gave only an image having a frictional fastness inferior to that of the black recording liquid used in Example 2. The results are shown in Table 2. Further, the storage stability test of the recording liquid was performed by the method described in Example 1.
There was no problem as well.

COMPARATIVE EXAMPLE 1 Ion-exchanged water was added to Remazol Brilliant Red F3B liq40 (manufactured by Mitsubishi Kasei Hoechst), followed by 2 more days.
A 5% aqueous sodium hydroxide solution was added, and the mixture was reacted at 85 ° C. for 5 hours. Salting out was performed by adding 20% of salt to the solution, and the cake was collected by filtration. This was dissolved again in ion-exchanged water, 20% salt solution was added to the solution, salting out was performed again, and the cake was collected by filtration, washed and dried to obtain a magenta dye (compound 2 shown below).

[0037]

Embedded image

Was obtained. 5 parts of the obtained dye was dissolved in 100 parts of ion-exchanged water, and after adjusting the pH to 1 or less with 35% hydrochloric acid, the resulting dye precipitate was collected by filtration. Further, ion-exchanged water and a 25% aqueous solution of sodium hydroxide were added thereto, and the pH was adjusted to 9%.
A dye solution having a total weight of 130 parts was obtained. After adding 15 parts of diethylene glycol and 5 parts of isopropyl alcohol, the mixture was sufficiently stirred, filtered under pressure through a microfiltration membrane having a pore diameter of 0.2 μm, and deaerated with a vacuum pump and an ultrasonic cleaner to prepare a recording liquid. did. The NMR chart of the dye was as shown in FIG. 2, and it was found that the dye had no broad peak.

Using the obtained magenta recording liquid, a two-color solid image was printed with the printer and the genuine yellow recording liquid in the same manner as in Example 1. The resulting image had a vivid color tone in both the yellow and magenta portions, but had undesired bleeding at the boundary between the colors. The results are shown in Table 2. On the other hand, Example 1
The storage stability of the recording solution was confirmed by the method described in (1) above, but no problem was observed as in Example 1.

Comparative Example 2 The magenta recording liquid used in Comparative Example 1 was used in place of the magenta recording liquid used in Example 2, and the other examples were used.
A similar experiment was performed. The resulting image was unfavorable, with noticeable bleeding at the color boundaries. The results are shown in Table 2. On the other hand, the storage stability of the recording liquid was confirmed by the method described in Example 1, but no particular problem was observed as in Example 1.

Comparative Example 3 In place of the magenta recording liquid used in Example 3, the magenta recording liquid used in Comparative Example 1 was used.
A similar experiment was performed. The resulting image was undesired with noticeable bleeding at the color boundaries. The results are shown in Table 2. On the other hand, the storage stability of the recording liquid was confirmed by the method described in Example 1, but no particular problem was observed as in Example 1.

[0042]

[Table 1]

[0043]

[Table 2]

From the above results, when a recording liquid containing a broad peak is used, or when an image is printed in combination with a pigment-containing recording liquid, a beautiful image with little bleeding at a color boundary can be obtained, and its effect. Was found to be even more remarkable by using a pigment-containing recording liquid that gives better friction fastness and a recording liquid containing the above-mentioned broad peak in combination.

[0045]

According to the present invention, it is possible to obtain a recording liquid and a recording method which give a vivid color to a recorded image, have little bleeding at a color boundary, and have good stability when stored for a long time. Also, by using the pigment-based recording liquid in combination, a beautiful image with less bleeding at the color boundary when the image is printed can be obtained.

[Brief description of the drawings]

FIG. 1 is an NMR spectrum of Compound 1 in Example 1.

FIG. 2 is an NMR spectrum of Compound 2 in Comparative Example 1.

[Explanation of symbols]

1: Peak of water (H ₂ O) 2: Peak of water (H ₂ O)

Claims (9)

[Claims] 1. A spectrum diagram of 400 MHz proton nuclear magnetic resonance analysis (hereinafter abbreviated as "NMR") has at least one peak having a half width of 0.1 ppm or more (hereinafter abbreviated as "broad peak"). A recording liquid comprising at least a water-soluble dye and an aqueous medium. 2. The recording liquid according to claim 1, wherein the recording liquid has one or more broad peaks between 1 and 4 ppm and between 7 and 9 ppm in a NMR spectrum. 3. The number of broad peaks is 25% of the total number of peaks.
The recording liquid according to claim 1, wherein: 4. The recording liquid according to claim 1, wherein the water-soluble dye contains one or more azo groups. 5. The method according to claim 1, wherein the water-soluble dye is any one of magenta, yellow and cyan.
5. The recording liquid according to any one of 4. 6. A recording liquid according to claim 1, further comprising a pigment as a coloring agent. 7. An ink jet recording method comprising using the recording liquid according to claim 1 as an ink. 8. A recording liquid containing a pigment is used in combination as an ink,
8. The ink jet recording method according to claim 7, wherein the print recording is performed simultaneously or sequentially. 9. The ink jet recording method according to claim 8, wherein the recording liquid containing a pigment gives a printed image having a value of friction fastness class 2 or higher on plain paper.