JP3362497B2 - Recording liquid - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a recording liquid. Specifically, it relates to a recording liquid suitable for inkjet recording.

[0002]

2. Description of the Related Art A so-called ink jet recording method has been put into practical use in which droplets of a recording liquid containing a water-soluble dye such as a direct dye or an acid dye are ejected from a minute ejection orifice to perform recording. Regarding this recording liquid, it is fast to fix to general recording paper such as PPC (plain paper copier) paper such as electrophotographic paper, fan hold paper (continuous paper such as computers), and printing of printed matter. It is required that the quality is good, that is, the print has no bleeding and the contour is clear, and that the storage stability as a recording liquid is also excellent. Significantly limited.

On the other hand, dyes for recording liquids have sufficient solubility in the above-mentioned limited solvents and are stable even when stored as recording liquids for a long period of time.
Further, although it is required that the printed image has a high density and is excellent in water resistance and light resistance, it has been difficult to satisfy many of these requirements at the same time. Therefore, various methods (for example, JP-A-61-101574, JP-A-61-101576, JP-A-61-195176) are used.
No. 61-62562, JP-A 61-2477.
71, JP-A-62-156168, JP-A-63-6.
3765, JP-A-63-295685, JP-A-1-
123866, JP-A-2-16171, JP-A-3-
122171, JP-A-3-203970, JP-A-4
No. 15327, Japanese Patent Application Laid-Open No. 4-279671, etc.) have been proposed, but they have not been sufficiently satisfied with the demands of the market.

[0004]

DISCLOSURE OF THE INVENTION The present invention has good print quality even when recorded on plain paper for ink jet recording, writing instruments, etc., and has a high density of recorded images, light resistance and especially It is an object of the present invention to provide a black recording liquid which is excellent in water resistance and color tone of a recorded image and has good stability when stored for a long period of time.

[0005]

The present inventors have accomplished the present invention by confirming that the above objects can be achieved when a specific dye is used as a recording liquid component. That is, the gist of the present invention is to provide an aqueous medium and at least one of the dyes whose free acid form is represented by the general formula {1} in claim 1.
It exists in the recording liquid containing the seed.

The present invention will be described in detail below. The dye used in the present invention has a free acid form represented by the general formula {1} in claim 1. Specifically, in the general formula {1}, examples of the branched alkyl group represented by R ₁ include iso-alkyl groups such as iso-propyl group, iso-butyl group and iso-pentyl group. Examples of the alkyl group represented by R ₂ include a methyl group, an ethyl group ,. n-or
Examples thereof include iso-propyl group, n-, iso-, sec- or tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group and nonyl group. Examples of the substituent of the phenyl group represented by R ₃ include —COOH, —SO ₃ H, or a halogen atom such as chlorine, iodine or bromine.

The dye used in the present invention may be used as it is in the free acid form represented by the general formula {1}, but if it is obtained in the salt form at the time of production, it may be used as it is, or as desired. It may be converted to the salt form. A part of the acid group may be a salt type, and a salt type dye and a free acid type dye may be mixed. Examples of such salt type are salts of alkali metals such as Na, Li, K, ammonium salts, quaternary ammonium salts, preferably quaternary ammonium salts whose substituents are alkyl groups or hydroxyalkyl groups, or organic Examples include amine salts. Examples of organic amines include lower alkyl amines, hydroxy-substituted lower alkyl amines,
Examples thereof include carboxy-substituted lower alkyl amine and polyamine having 2 to 10 alkyleneimine units having 2 to 4 carbon atoms. In the case of these salt types, the type is not limited to one type, and a plurality of types may be mixed.

In the structure of the dye used in the present invention, when a plurality of acid groups are contained in one molecule, the plurality of acid groups may be salt type or acid type and different from each other. Good. Specific examples of these dyes include, for example, Nos. Examples thereof include dyes having structures shown in 1-21.

[0009]

[Chemical 2]

[0010]

[Chemical 3]

[0011]

[Chemical 4]

[0012]

[Chemical 5]

[0013]

[Chemical 6]

[0014]

[Chemical 7]

[0015]

[Chemical 8]

The azo dye represented by the general formula {1} is
It can be manufactured according to a method known per se. For example, No. The dye represented by 1 can be produced by the following steps (A) to (C).

(A) From 5-aminoisophthalic acid and 2-methoxy-5-isobutanoylaminoaniline, a conventional method [for example, Yutaka Hosoda "New Dye Chemistry" (published by Gihodo on December 21, 1973) 396 to 409], a monoazo compound is produced through a diazotization and a coupling step.

(B) The obtained monoazo compound and 7-amino-1-hydroxy-3-sulfonic acid (γ acid) are subjected to a diazotization reaction and a coupling step reaction according to a conventional method.

(C) By subjecting the resulting reaction solution to salting out with sodium chloride, the desired dye No. A disazo compound represented by 1 is produced.

The content of the dye of the general formula {1} in the recording liquid of the present invention is preferably 0.5 to 5% by weight, more preferably 2 to 4% by weight, based on the total amount of the recording liquid.
As the solvent used in the present invention, water and water-soluble organic solvents such as ethylene glycol, propylene glycol, butylene glycol, diethylene glycol,
Triethylene glycol, polyethylene glycol (#
200), polyethylene glycol (# 400), glycerin, N-methylpyrrolidone, N-ethylpyrrolidone, 1,3-dimethylimidazolidinone, thiodiethanol, dimethyl sulfoxide, ethylene glycol monoallyl ether, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether. It preferably contains ether, 2-pyrrolidone, sulfolane, ethyl alcohol, isopropanol, diethanolamine, triethanolamine and the like. These water-soluble organic solvents are usually used in the range of 1 to 50% by weight based on the total amount of the recording liquid. On the other hand, water is 45 to 9 with respect to the total amount of the recording liquid.
Used in the range of 5% by weight.

The recording liquid of the present invention contains 0.
1-10 wt% urea, preferably 0.5-5 wt% urea,
By adding a compound selected from thiourea, biuret, and semicarbazide, or by adding 0.001 to 5.0% by weight of a surfactant, the quick-drying property after printing and the printing quality can be further improved. it can.

[0022]

EXAMPLES The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded.

[Example 1] 10 parts by weight of diethylene glycol, 3 parts by weight of isopropyl alcohol, 1
Water was added to 3 parts by weight of the above dye, and the pH was adjusted to 9 with aqueous ammonia to adjust the total amount to 100 parts by weight. The composition was thoroughly mixed and dissolved, pressure-filtered with a Teflon filter having a pore size of 1 μm, and then deaerated with a vacuum pump and an ultrasonic cleaner to prepare a recording liquid. Using the obtained recording liquid, inkjet recording was performed on an electrophotographic paper (Fuji Xerox Co., Ltd.) using an inkjet printer (trade name: HG-3000, Epson Co. product) to obtain a high density black printed matter. Further, various evaluations were performed by the methods (a), (b) and (c) below.

(A) Density of recorded image: The OD value of the recorded image printed solid is a Macbeth densitometer (trade name: TR-9
27).

(B) Lightfastness of recorded image: Xenon fade meter (manufactured by Suga Test Instruments Co., Ltd.) was used to record 10
Irradiate for 0 hours and spectroscopic color difference meter (trade name: SZ-Σ8
0, a product of Nippon Denshoku Industries Co., Ltd.), and the color difference (ΔE) of the recorded matter before and after the test was measured and judged according to the following criteria.

[Table 1] ◯: Discoloration and fading is ΔE or less than 10 Δ: Discoloration and fading is ΔE of 10 to 20 X: Discoloration and fading is ΔE or more than 20

(C) Water resistance and water resistance test of recorded image [Test method] After the recorded image was immersed in tap water for 5 minutes, the bleeding of the image was visually evaluated according to the following criteria.

[Table 2] ◯: There is no image blur. Δ: Bleed of the image is small. X: The blurring of the image is large. The OD value of the solid printed portion before and after the immersion is measured by a Macbeth densitometer (TR-927), and the change in the density of the solid printed portion before and after the immersion is shown by the OD residual rate according to the following formula.

[Formula 1] OD residual rate = (OD value after immersion / OD value before immersion)
× 100 (%)

(D) Storage stability of recording liquid: The recording liquid was sealed in a Teflon container and examined for changes after storage at 5 ° C. and 60 ° C. for 1 month.

[Table 3] ◯: No change. X: There is a change. The results of these evaluation tests (a) to (d) are shown in Table 1 below.

[Example 2] 5 parts by weight of glycerin, 10 parts by weight of ethylene glycol, Water was added to 2.5 parts by weight of dye 8 and the pH was adjusted to 9 with aqueous ammonia to make 100 parts by weight, and the composition was treated by the method described in Example 1 to prepare a recording liquid. . Printing was carried out in the same manner as in Example 1 using this recording liquid, and as a result, a high-concentration bluish-black recorded product was obtained. In addition, for this recorded matter, Example 1
Various evaluations according to (a) to (d) were performed. The results are shown in Table 1 below.

[Example 3] 10 parts by weight of diethylene glycol, 5 parts by weight of N-methylpyrrolidone, 3 parts by weight of isopropyl alcohol, Water was added to 3 parts by weight of 16 dyes and the pH was adjusted to 9 with aqueous ammonia to adjust the total amount to 10
The recording liquid was prepared by treating the composition in an amount of 0 part by weight with the method described in Example 1. Printing was carried out in the same manner as in Example 1 using this recording liquid, and as a result, a high-concentration bluish-black recorded product was obtained. Further, for this recorded matter, (a) of Example 1
Various evaluations according to (d) were performed. The results are shown in Table 1 below.

Comparative Example 1 A recording liquid was prepared in the same manner as in Example 1 except that the dye having the structure (a) below was used instead of the dye. Using this recording liquid, recording and printing were performed in the same manner as in Example 1 to obtain a black recorded matter. Further, various evaluations according to (a) to (d) of Example 1 were performed on this recorded matter. The results are shown in Table 1 below.

Comparative Example 2 A recording liquid was prepared in the same manner as in Example 2 except that the dye having the structure (b) below was used instead of the dye. Using this recording liquid, recording and printing were performed in the same manner as in Example 1 to obtain a black recorded matter. Further, various evaluations according to (a) to (d) of Example 1 were performed on this recorded matter. The results are shown in Table 1 below.

[Comparative Example 3] A recording liquid was prepared in the same manner as in Example 3 except that the dye having the structure (c) below was used instead of the dye. Recording and printing were performed using this recording liquid in the same manner as in Example 1 to obtain a bluish black recorded material. Further, various evaluations according to (a) to (d) of Example 1 were performed on this recorded matter. The results are shown in Table 1 below.

[0033]

[Chemical 9]

[0034]

[Table 4]

[0035]

INDUSTRIAL APPLICABILITY The recording liquid of the present invention is used for ink jet recording and writing instruments, and when recorded on plain paper, a black recorded matter can be obtained, and its printing density, light resistance, and water resistance. In addition to being excellent in storage stability as a recording liquid.

Continuation of the front page (56) References JP-A-5-125318 (JP, A) JP-A-7-34020 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C09D 11 / 00-11/20 CA (STN) REGISTRY (STN)

Claims (2)

(57) [Claims] 1. A recording liquid containing an aqueous medium and at least one dye selected from the dyes represented by the following general formula {1} in the form of a free acid. [Chemical 1] (In the formula, R ₁ represents a branched alkyl group having 3 to 8 carbon atoms, R ₂ represents a linear or branched alkyl group having 1 to 9 carbon atoms, and R ₃ has a hydrogen atom or a substituent. and which may be a phenyl group, a -CH ₂ COOH or -C ₂ H ₄ COOH, m is 1 or 2, n represents 0 or 1.) 2. A dye for inkjet recording, wherein the form of the free acid comprises at least one selected from dyes represented by the following general formula {1}. [Chemical 2] (In the formula, R ₁ represents a branched alkyl group having 3 to 8 carbon atoms, R ₂ represents a linear or branched alkyl group having 1 to 9 carbon atoms, and R ₃ has a hydrogen atom or a substituent. and which may be a phenyl group, a -CH ₂ COOH or -C ₂ H ₄ COOH, m is 1 or 2, n represents 0 or 1.)