JPH0578611A - Production of recording solution - Google Patents

Abstract

PURPOSE:To obtain a recording solution not causing its clogging and having excellent recording characteristics by purifying a specific dye so as to give an inorganic component content of <= a specific amount and subsequently mixing the dye as a recording agent in a form of its Na salt with a liquid medium containing water and a glycol compound. CONSTITUTION:A dye of the formula (M is H, Na) is preliminarily purified so as to give an inorganic component content comprising <=1wt.% of NaCl, <=0.5wt.% of Na2O4, and <=50ppm of Ca<2+> ions, and further again adjusted so that the content of Na is >=55mol.% based on the whole amount of M in the M of the formula. The recording agent thus produced is mixed with a liquid medium containing at least water and a glycol compound for the dissolution or dispersion of the recording agent to obtain the objective recording solution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention does not cause clogging of a novel recording liquid used for recording with an ink, particularly a recording means, and in particular, a fine discharge port (discharge orifice) provided in a recording head. The present invention relates to a method of manufacturing a recording liquid suitable for a recording system in which the recording liquid is ejected from the recording medium and ejected as droplets to perform recording.

[0002]

2. Description of the Related Art Conventionally, a writing instrument (fountain pen, felt-tip pen, etc.) as a recording means for recording on a recording material such as paper, is an ink prepared by dissolving various dyes in water or an organic solvent. It is used.

Further, in a so-called ink jet recording system in which a liquid in a recording head is ejected from an ejection orifice by virtue of vibration by a piezo-vibrator or electrostatic attraction due to application of a high voltage, various dyes are treated with water. Alternatively, it is known that a composition dissolved in an organic solvent or the like is used. However, compared to general fountain pens and stationery inks such as felt pens, inkjet recording liquids
Many properties require more stringent conditions.

In such an ink jet recording method, recording liquid droplets called so-called ink are ejected and adhered to a recording material to perform recording. Such a recording liquid contains a recording agent (a dye or a pigment is used) and a liquid medium (water or various organic solvents or a mixture thereof) which dissolves or disperses the recording agent as a basic component, and if necessary, various additives are added. Agent has been added.

Conventionally, as this type of recording liquid, for example, JP-B-50-8361, JP-B-51-40404, JP-B-52-13126, JP-B-52-13127 and JP-A-50-95008 are shown. As described above, it is known that various dyes or pigments are dissolved or dispersed in an aqueous or non-aqueous solvent.

The preferable conditions for this type of recording liquid are as follows: 1) Liquid physical properties (viscosity, surface tension, electromotive force) matching ejection conditions (driving voltage of piezoelectric element, driving frequency, shape and material of orifice, orifice diameter, etc.). Have a degree). 2) Stable and does not cause clogging during long-term storage. 3) The recording material (paper, film, etc.) is quickly fixed, the periphery of the dots is smooth, and the bleeding is small. 4) The color tone of the printed image is clear and the density is high. 5) The printed image is excellent in water resistance and light resistance. 6) The recording liquid should not attack surrounding materials (container, connecting tube, sealant, etc.). 7) It has excellent safety such as odor, toxicity, and flammability. Etc.

It is extremely difficult to satisfy the above-mentioned various properties at the same time, and the above-mentioned prior art is unsatisfactory in this respect.

As described above, the recording liquid applied to the recording for the purpose is basically composed of the dye and its solvent. Therefore, the characteristics of the recording liquid are the components used as the dye and the liquid medium. It is largely dependent on the unique properties of. Therefore, it is a very important technique in the technical field to select the dye and the liquid medium so that the recording liquid has the above-mentioned various characteristics.

[0009] Among them, a recording liquid using a yellow dye has not yet been known to satisfy all the above-mentioned characteristics.

That is, mainly in order to enhance the effect of preventing clogging of the recording liquid discharge port due to the precipitation of inorganic salts, the stability of the recording liquid, and especially the anticorrosion effect of the metal component of the writing instrument, Included, for example, NaCl, N
a Method of using inorganic salts such as a ₂ SO ₄ or ions such as Ca ⁺⁺ with ultrafiltration, treatment with ion exchange resins or treatment with various organic solvents, or treatment with salting out, acidifying, etc. According to this, for example, the amount of NaCl in the dye is 5% by weight or less, and Na ₂ SO ₄ is removed from the dye so as to be 1% by weight or less.

However, if such a processing is performed by C.I. I. If you use a yellow dye typified by Direct Yellow 86,
It has been found that the chemical and physical properties of the dye itself change, and in particular, contrary to the above object, the stability and long-term storage stability of the recording liquid using such a dye are considerably deteriorated.

As the liquid medium of the recording liquid, conventionally, water or a mixture of water and various water-soluble organic solvents has been used. However, a recording liquid satisfying the characteristics of the above-mentioned recording liquid in a relatively general manner is used. As a liquid medium that can be formed, a mixture of water and glycols such as ethylene glycol and diethylene glycol is preferably used, and it is due to a marked decrease in the solubility of the yellow dye after the above treatment in such a liquid medium. Conceivable.

[0013]

As a result of intensive studies, the present invention is suitable for a recording liquid used for such a purpose.
In particular, it has been completed by finding a treatment method for obtaining a dye having a low content of inorganic salts that causes clogging and the like, which has excellent solubility in a liquid medium mainly composed of a mixture of water and glycols. is there.

[0014]

That is, a method for producing a recording liquid according to the present invention is a recording method in which a recording agent is mixed with a liquid medium containing at least water and glycols for dissolving or dispersing the recording agent. In the method for producing a liquid, the following general formula (A) is used as the recording agent;

[0015]

[Chemical 2] [In the formula, M represents either H or Na. ] The inorganic salt component content of the dye represented by
A process of purifying Cl to 1 wt% or less, Na ₂ SO ₄ to 0.5 wt% or less, and Ca ⁺⁺ ions to 50 ppm or less, and further, M represented by the general formula (A).
Is used after undergoing a process of re-adjusting so that 55 mol% or more of the total amount becomes Na.

In the present invention, the liquid medium constituting the recording liquid preferably contains 70% by weight or less of water with respect to the liquid medium.

In the recording liquid of the present invention, at least one of the dyes represented by the general formula (A) as a recording agent component, at least water as a liquid medium, and glycols particularly effective for preventing clogging. A liquid medium containing is used.

In the present invention, glycols that can be contained in the liquid medium used for the composition of the recording liquid include polyalkylene glycols such as polyethylene glycol and polypropylene glycol; ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol, diethylene glycol and other alkylene glycols having an alkylene group of 2 to 6 carbon atoms; glycerin; ethylene glycol methyl ether, diethylene glycol methyl (or ethyl) ether , Lower alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl (or ethyl) ether, and the like. It can be used as.

The content of the glycols in the liquid recording is
Generally, it is 10 to 70% by weight, preferably 20 to 60%, and more preferably 25 to 40% by weight based on the total amount of the recording liquid.

In addition to the above glycols as a liquid medium component, the recording liquid of the present invention may optionally be a water-soluble organic solvent such as methyl alcohol, ethyl alcohol, or n in order to improve the characteristics of the recording liquid. -Propyl alcohol, isopropyl alcohol, n-butyl alcohol,
C1-C4 alkyl alcohols such as sec-butyl alcohol, tert-butyl alcohol and isobutyl alcohol; amides such as dimethylformamide and dimethylacetamide; ketones or ketone alcohols such as acetone and diacetone alcohol; tetrahydrofuran and dioxane And the like; one or more nitrogen-containing heterocyclic ketones such as N-methyl-2-pyrrolidone and 1,3-dimethyl-2-imidazolidinone may be added.

The content of the water-soluble organic solvent including the above-mentioned glycols in the recording liquid is generally 10 to 70% by weight, preferably 20 to 60%, and more preferably the total weight of the recording liquid. The range is 30 to 55%.

The water content at this time is determined in a wide range depending on the kind of the solvent component, its composition or desired properties of the recording liquid, but is generally 30 to 30% with respect to the total weight of the recording liquid. The range is 90%, preferably 40 to 80%, more preferably 45 to 70%.

The dye used in the production of the recording liquid in the present invention comprises at least one of the dyes represented by the above-mentioned general formula (A), and particularly for a liquid medium containing water and glycols of the composition described later. It shows good solubility.

Generally, the solubility of the dye represented by the general formula (A) particularly in water contained as a component of the liquid medium changes depending on the proportion of Na in M contained in the dye. Therefore, in the dye used in the recording liquid using the liquid medium having the above composition, it is desirable that 55 mol% or more of the total amount of M contained in the dye is Na.

The dye that can be used for forming the recording liquid in the present invention is C.I. I. Direct Yellow 86 can be produced as a starting material.

That is, C.I. I. Direct yellow 8
From No. 6, ultrafiltration, treatment with an ion exchange resin or treatment with various organic solvents, or a method in which treatments such as salting out and acidifying are used in combination, NaCl, Na ₂ S
After removing inorganic components such as O ₄ and calcium ions, the amount of Na in the dye molecule is then quantified by various analysis methods, for example, NaOH is added to the dye aqueous solution to supplement the insufficient amount of Na. The method can be produced by controlling the ratio of Na to the total amount of M to a predetermined value.

The inorganic salt component content in the thus obtained dye solid is 1% by weight or less of NaCl and Na ₂ S.
O _{4 is} 0.5 wt% or less and Ca ^{++ is} 50 ppm or less, which is extremely low. The recording liquid formed by this dye has excellent stability, with no clogging of the recording liquid discharge port due to precipitation of inorganic salts. It is also a suitable recording liquid from the viewpoint of preventing corrosion of constituent members made of metal in a writing instrument.

In the present invention, the ratio of Na to the total amount of M is measured as follows.

First, the amount of total Na contained in the dye after the inorganic component removal treatment was quantified by atomic absorption spectrometry, and then, in the form of the free inorganic salt contained in the dye, that is, in the dye compound. The unbound Na is Cl ⁻ since almost all of the Na is NaCl and Na ₂ SO _4.
And SO ₄ ⁻ were quantified by ion chromatography, and from the obtained values, Na existing as an inorganic salt was determined.
Is calculated, and the amount of Na existing as an inorganic salt is subtracted from the total amount of Na obtained above to approximately obtain the amount of Na bound in the dye compound.

Finally, from the total amount of M calculated from the number of moles of the dye used in the measurement (from the constitutive formula, one molecule has 4 M), and the amount of Na bound in the dye compound,
Determine the ratio of Na to the total amount of M.

In the recording liquid obtained in the present invention, the content of the dye represented by the general formula (A) is determined depending on the type of liquid medium, the characteristics required for the recording liquid and the like. Generally, 0.05% by weight based on the total weight of the recording liquid.
The range is 10%, preferably 0.05 to 6%, and more preferably 0.05 to 4%. The dyes can be used alone or in combination of two or more kinds, or can be used in combination with other direct dyes or acid dyes.

The recording liquid prepared from such components is
When used by itself as a recording liquid for writing instruments such as fountain pens, water-based ballpoint pens, felt pens, etc., the fixing property to the recording material or the light resistance, weather resistance and water resistance of the recorded image are well balanced. It is not only excellent, but also consists of a combination of a suitable liquid medium and a dye, and in particular the dye has excellent solubility in the liquid medium, the instability observed in conventional recording liquids, the pen tip after being left for a long time, etc. It is an excellent recording liquid in which no dye is deposited at the recording liquid discharge port and clogging does not occur. Even when used for ink jet recording, recording characteristics (signal responsiveness, stability of droplet formation, ejection stability, long-term continuous recording performance, ejection stability after long-term recording suspension), storage Stability, fixability to recording material, or recorded image light resistance, weather resistance, water resistance, etc. are all well-balanced and excellent, and among these characteristics, stability, long-term It has excellent storage stability and does not cause clogging of the discharge orifice, and has a clear advantage over conventional recording liquids.

The recording liquid of the present invention may further contain various conventionally known additives in order to further improve such characteristics. For example, viscosity modifiers such as polyvinyl alcohol, celluloses and water-soluble resins; various cationic, anionic or nonionic surfactants; surface tension modifiers such as diethanolamine and triethanolamine; pH modifiers with buffers; antifungal agents. Etc. can be mentioned.

When applied to an ink jet system in which the recording liquid is ejected by the action of thermal energy, thermal physical property values (for example, specific heat, thermal expansion coefficient, thermal conductivity, etc.) must be adjusted. There is also.

According to the present invention, the physical properties such as viscosity and surface tension are within the proper ranges, and the pen tip of a fountain pen and the recording liquid ejection port such as a fine orifice in an ink jet recording apparatus are not clogged, and the properties are sufficiently reduced. It gives a high-density recorded image, does not cause changes in physical properties or precipitation of solids during storage, can record on various members without limiting the type of recording material, has a high fixing speed, is water resistant, A recording liquid which gives an image excellent in light resistance, abrasion resistance and resolution can be obtained.

[0036]

The present invention will be described in more detail by the following examples. Examples 1 to 5 Commercial dye Kayaku Direct yellow
w R. special (C.I. Direct ye)
200 g of (low 86) (manufactured by Nippon Kayaku Co., Ltd.) was stirred in 4 l of a saturated aqueous solution of Glauber's salt for 1 hr to carry out salting-out treatment, filtered, and dried to obtain a dried product I.

Then, 30 g of the dried product I was dissolved in 300 cc of methyl cellosolve by stirring for 1 hr, filtered, and dried to obtain a dried product II.

Next, 10 g of the dried product II was dissolved in 150 cc of ion-exchanged water, poured into 800 cc of isopropyl alcohol, stirred for 30 minutes, filtered and dried to obtain a dried product III. The ratio of Na to the total amount of M contained in the dye in the dried product III was analyzed and calculated based on the above-mentioned analysis method to be 41 mol%.

Then, 10 g of the above dried product III was weighed and dissolved in 500 cc of ion-exchanged water to obtain 5 parts.
Individual pieces were prepared, and a predetermined amount of 1N NaOH aqueous solution shown in Table 1 was added to each of them and stirred for 4 hours.

Next, the solution is dried and powdered,
Dye No. Five dyes 1 to 5 were obtained. The ratio of Na to the total amount of M of each dye is shown in Table 1.

[0041]

[Table 1] Next, each of the dyes shown in Table 1 was added to a liquid medium having the following composition so that the concentration in the recording liquid would be 3% by weight, and sufficiently mixed and dissolved,
This was pressure-filtered with a Teflon filter having a pore size of 1 μm, and then deaerated using a vacuum pump to obtain a recording liquid. (Liquid medium composition) Ion-exchanged water (hereinafter abbreviated as water) 60 parts by weight Diethylene glycol 40 parts by weight An on-demand type recording head for ejecting the recording liquid by a piezo vibrator using each of the five types of recording liquids obtained ( Ink jet recording was carried out by a recording apparatus having a discharge orifice diameter of 50 μm, a piezo vibrator driving voltage of 60 V, and a frequency of 4 KHz), and the following items which were particularly problematic for conventional recording liquids were examined. The results obtained are shown in Table 2. (T ₁ ) Long-term storability of recording liquid: The recording liquid was sealed in a glass container and stored at −30 ° C. and 60 ° C. for 6 months. Then, it was tested and evaluated whether precipitation of insoluble matter was observed. The case where the precipitation of the insoluble matter was not recognized was designated as (◯), and the case where the precipitation of the insoluble matter was recognized was designated as (x). (T ₂ ) Discharge stability: Continuous discharge was performed for 24 hours in each of the atmospheres at room temperature, 5 ° C., and 40 ° C. The case where stable and high quality recording was possible under all conditions was (○), and the case where it was not possible was (x). In addition, the middle of the two was set as (△). (T ₃ ) Ejection responsiveness: The recording apparatus was operated after being left for 3 months, and the ejection state in intermittent ejection every 2 seconds before and after leaving was examined. In the case where a stable and uniform discharge state before leaving was obtained even after leaving (◎), some disturbance was observed in the discharge at the beginning of the operation after leaving, but a stable and uniform discharge state was obtained after a few seconds. The case (◯) was given, and the case where a stable and uniform discharge state before leaving was not obtained after leaving was taken as (x). (T ₄ ) Orifice clogging: After leaving the recording apparatus for 3 months, the tip of the orifice was observed with a microscope and no clogging was observed (○). (Δ), and (x) when the nozzle was completely blocked. (T ₅ ) Quality of recorded image: The recorded image has a high density and is clear, the rate of decrease in density after exposure to room light for 3 months is 1% or less, and when immersed in water for 1 minute. If the image bleeding was extremely slight (○),
The recorded image has a high density and is not clear, or the image is clear but has a density decrease rate of more than 1% after being exposed to room light for 3 months, and when it has been immersed in water for 1 minute. The case where marked bleeding was observed was defined as (x). (T ₆ ) Fixability to various recording materials: After printing for 15 seconds on the recording materials shown in the table below, the printed part was rubbed with a finger and the presence or absence of image shift and bleeding were determined. The case where there was no image shift or bleeding and the like showed excellent fixability was indicated by (◯), and the case where image shift or bleeding was observed was indicated by (x).

Name of recording material Classification manufacturer Silver ring fine paper Sanyo Kokusaku Pulp Co., Ltd. Seven Star fine paper Hokuetsu Paper Co., Ltd. White Peony Medium paper Honshu Paper Co., Ltd. Toyo Roshi Paper Co., Ltd. 4 Non-size paper Toyo Roshi Kaisha, Ltd. Comparative Example 1 Dried product III obtained in Example 1 (total M in dye)
Inkjet recording was carried out in the same manner as in Example 1 except that the proportion of Na in the amount was 41 mol%) was used as a recording agent component, and each item (T ₁ ) to (T ₆ ) was examined. Was done. Table 2 shows the obtained evaluation results. Comparative Example 2 10 g of the dried product III obtained in Example 1 was added to 50
To the one dissolved in 0 cc of ion-exchanged water, 1N N
3.2 cc of aOH aqueous solution was added, the mixture was stirred for 4 hours, and the solution was dried and pulverized to obtain a dye in which the proportion of Na in the total amount of M in the dye was 54 mol%. Then, a recording liquid was prepared in the same manner as in Example 1 except that this dye was used as a recording agent component, and ink jet recording was carried out in the same manner as in Example 1 to obtain (T ₁ ) to
Each item of (T ₆ ) was examined. Table 2 shows the obtained evaluation results.

[0043]

[Table 2] Examples 6 to 10 Five kinds of recording liquids were prepared in the same manner as in Examples 1 to 5 by using the liquid medium having the following composition and the dyes used in Examples 1 to 5, respectively.

Water 60 parts by weight Polyethylene glycol (molecular weight 300) 15 parts by weight Diethylene glycol 15 parts by weight N-methyl-2-pyrrolidone 15 parts by weight Examples 1 to 5 for each of the five recording liquids obtained
InkJet recording is carried out in the same manner as in (T ₁ )
We were examined for each item of ~ (T _6). Table 3 shows the obtained evaluation results. Comparative Example 3 Recording was carried out in the same manner as in Example 6 except that the dried product III obtained in Example 1 (having a proportion of Na in the total amount of M in the dye of 41 mol%) was used as the recording agent component. The liquid was adjusted, and inkjet recording was carried out in the same manner as in Example 6 to examine the items (T ₁ ) to (T ₆ ). Table 3 shows the obtained evaluation results. Comparative Example 4 Na in the total amount of M in the dye produced in Comparative Example 1
A recording liquid was prepared in the same manner as in Example 6 except that a dye having a ratio of 54 mol% was used as a recording agent component, and inkjet recording was carried out in the same manner as in Example 1 (T ₁ ). It was carried out a study for each item of ~ (T _6). Table 3 shows the obtained evaluation results.

[0045]

[Table 3] Examples 11 to 20 Each of the recording liquids prepared in Examples 1 to 10 was individually filled in a felt-tip pen, and each of these was used to write on a medium-quality paper (White Peony (trade name), Honshu Paper Co., Ltd.). , The water resistance of the recorded print, further remove the cap 2
The writability of the felt pen after standing for 4 hours was examined.

In the recording liquid used in this example,
In all cases, the recorded prints were excellent in water resistance, and even after being left for 24 hours, deposition of dye or the like was not observed on the pen tip, and good recording properties were exhibited.

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[Procedure amendment]

[Submission date] January 20, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 1

[Correction method] Change

[Correction content]

[Chemical 1] [In the formula, M represents either H or Na. ], The inorganic component content of the dye represented by
Is 1 wt% or less, Na ₂ SO ₄ is 0.5 wt% or less, C
a ⁺⁺ ion is purified to 50 ppm or less, and further, the M represented in the general formula (A) is readjusted so that 55 mol% or more of the total amount thereof is Na. A method for producing a recording liquid, which is used.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

That is, in order to mainly enhance the effect of preventing clogging of the recording liquid discharge port due to the precipitation of the inorganic component , the stability of the recording liquid, and especially the anticorrosion effect of the constituent members made of metal in a writing instrument, Included, for example, NaCl,
A method in which inorganic salts such as Na ₂ SO ₄ and ions such as Ca ⁺⁺ are subjected to ultrafiltration, treatment with an ion exchange resin or treatment with various organic solvents, or treatments such as salting out and acidifying are combined. According to this, for example, the amount of NaCl in the dye is 5% by weight or less, and Na ₂ SO ₄ is removed from the dye so as to be 1% by weight or less.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

[0013]

As a result of intensive studies, the present invention is suitable for a recording liquid used for such a purpose.
In particular, it has excellent solubility in a liquid medium consisting mainly of a mixture of water and glycols, and it is an inorganic component that causes clogging.
Processing method for obtaining a less dye of partial content has been completed by finding.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0015

[Correction method] Change

[Correction content]

[0015]

[Chemical 2] [In the formula, M represents either H or Na. ], The inorganic component content of the dye represented by
Is 1 wt% or less, Na ₂ SO ₄ is 0.5 wt% or less, C
a ⁺⁺ ion is purified to 50 ppm or less, and further, the M represented in the general formula (A) is readjusted so that 55 mol% or more of the total amount thereof is Na. It is characterized by being used.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

[0027] The absence of dye-solid obtained in this way
Machine component content is less than 1 wt% NaCl, Na ₂ SO
₄ Very low, 0.5 wt% or less and Ca ⁺⁺ 50 ppm or less. The recording liquid formed by this dye is excellent in stability without clogging of the recording liquid discharge port due to precipitation of inorganic salts, and especially writing instruments. It is also a preferable recording liquid from the viewpoint of preventing the corrosion of the constituent members made of metal in (1).

[Procedure Amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0038

[Correction method] Change

[Correction content]

Next, 10 g of the dried product II was added to 150 cc
800cc isopropylamine after being dissolved in ion-exchanged water
Pour into alcohol and stir for 30 minutes, then filter and dry.
Dried product III was obtained. In the pigment in this dried product III
The ratio of Na in the total amount of M contained in the above analysis method
On the basis of the analysis and calculation, it was 41 mol%.Well
In addition, the content of inorganic components in the solid dye is 1% by weight of NaCl
% Or less, Na ₂ SO_Four Is 0.5 wt% or less, Ca⁺⁺Is 5
It was confirmed to be 0 ppm or less.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Keiko Nakagawa Nishi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (2)

[Claims] 1. A method for producing a recording liquid, comprising: a recording medium; and a liquid medium containing at least water and glycols for dissolving or dispersing the recording medium. ); [In the formula, M represents either H or Na. ] The inorganic salt component content of the dye represented by
A process of purifying Cl to 1 wt% or less, Na ₂ SO ₄ to 0.5 wt% or less, and Ca ⁺⁺ ions to 50 ppm or less, and further, M represented by the general formula (A).
Is used after being re-adjusted so that 55 mol% or more of the total amount thereof becomes Na. 2. In the liquid medium, 0.
The method for producing a recording liquid according to claim 1, wherein the recording agent is contained in an amount of 05 to 10% by weight.