JPH08170041A - Aqueous recording ink - Google Patents

Abstract

PURPOSE: To obtain the subject ink consisting essentially of a water-soluble dye, a specific water-soluble organic solvent and water, excellent in quick dryness, hardly oozing, not causing clogging in a nozzle and useful for ink jet recording, stamp, etc. CONSTITUTION: This composition consists essentially of (A) a water-soluble dye, (B) a water-soluble organic solvent containing propylene glycol monopropyl ether and (C) water. The component B comprises preferably (i) propylene glycol monopropyl ether and (ii) the other water-soluble organic solvent [preferably ethylene glycol, tetraethylene glycol or glycerol]. These components are preferably added in amounts of the component A of 0.5-30wt.%, preferably 1-20wt.%, the component (i) of 0.1-20wt.%, preferably 0.5-15wt.%, the component (ii) of 0-40wt.%, preferably 5-30wt.% and residual amount of water based on the aqueous recording ink.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous recording ink suitable for ink jet recording, writing instrument recorder, stamp and the like.

[0002]

2. Description of the Related Art For example, a water-based recording ink useful for ink jet recording is basically composed of a dye, an organic solvent and water, but the ink used for good ink jet recording. Various conditions are required for the composition. First, as the physical properties of the ink composition according to the droplet generation method and the droplet flight direction control method, for example, the viscosity, surface tension, specific electric conductivity, density, pH, etc. of the ink composition must be included in an appropriate range. Is.

It is necessary that these physical properties be stably maintained for a long period of time. That is, a deposit should not be generated due to a chemical change or the like during long-term storage, long-term use or recording suspension of the ink composition. In particular, the discharge nozzle of the recording device generally has a diameter of about 10 to 60 μm, and if the nozzle is clogged with deposits, it will not be possible to discharge droplets, and even if the nozzle is not completely clogged, solids and sticky substances will adhere to the vicinity of the nozzle. As a result, recording properties, ejection stability, and ejection responsiveness deteriorate.

Further, in recent ink jet systems utilizing heat energy, excellent heat resistance is required. In addition, it is naturally required that the recorded image has sufficiently high contrast, is clear, and has excellent water resistance and light resistance. Further, particularly in the case of recording on plain paper, it is required that the permeability of the ink is increased and at the same time, the image quality such as bleeding and show-through is not impaired.

Conventionally, water-based recording inks containing a water-soluble dye, a water-soluble organic solvent and water as essential components have been used as the water-based recording ink. As the water-soluble organic solvent, there have been used many types of ethylene glycol, propylene glycol, triethylene glycol, etc. Polyhydric alcohols, cellosolves, and carbitols are widely known and actually used.

[0006]

The present invention can be used especially for plain paper (writing paper, recording paper, copying paper, etc.) without any problems such as nozzle clogging, and it is possible to speed up after recording. It is an object of the present invention to provide an aqueous recording ink having excellent image quality such as excellent dryness and less bleeding.

[0007]

The present invention provides a water-soluble dye,
A water-based recording ink comprising a water-soluble organic solvent and water as essential components, which contains propylene glycol monopropyl ether as a water-soluble organic solvent.

A feature of the aqueous recording ink of the present invention is the use of a water-soluble organic solvent containing propylene glycol monopropyl ether. As the propylene glycol monopropyl ether, a commercially available product can be used as it is.

A particularly preferred embodiment of the aqueous recording ink of the present invention is to use, as the water-soluble organic solvent, a mixed solvent comprising propylene glycol monopropyl ether and a water-soluble organic solvent other than propylene glycol monopropyl ether. .

Examples of water-soluble organic solvents other than propylene glycol monopropyl ether preferably used in the present invention include the following water-soluble organic solvents.

For example, methanol, ethanol, isopropanol, n-propanol, n-butanol, sec-
Butanol, tert-butanol, isobutanol, alcohols such as benzyl alcohol, amides such as dimethylformamide, diethylformamide, ketones such as acetone and diacetone alcohol, ethers such as tetrahydrofuran and dioxane, lactams such as caprolactam, Ethylene glycol, propylene glycol, butylene glycol, pentane diol, diethylene glycol, triethylene glycol, tetraethylene glycol, thiodiglycol, hexylene glycol, 2-methyl-2,4-pentanediol, glycerin, 1,2,6-hexane Polyhydric alcohols such as triol, polyethylene glycol, (average molecular weight 200,
300, 400, 600 etc.), polypropylene glycol (average molecular weight 400, 700 etc.) and other polyalkylene glycols, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monophenyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether , Diethylene glycol monobutyl ether, triethylene glycol monomethyl ether,

Triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, propylene glycol monophenyl ether, dipropylene glycol monobutyl ether,
Lower alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl ether and triethylene glycol monoethyl ether, acetylene glycol derivatives (trade name: Surfynol: manufactured by Nisshin Chemical Co., Ltd.), monoethanolamine, diethanolamine, triethanolamine, etc. Alkanolamines, 1,3-dimethyl-
Nitrogen-containing heterocyclic ketones such as 2-imidazolidinone, 2
-Pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-vinyl-pyrrolidone, N-octyl-2-pyrrolidone, N- (2-hydroxyethyl) -2-pyrrolidone, N-cyclohexyl- 2-pyrrolidone, N-dodecyl-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N- (n-butyl) -2-pyrrolidone, N- (t-butyl) -2-pyrrolidone, N-hexyl-2- Pyrrolidone, N- (3-hydroxypropyl) -2-pyrrolidone, N- (2-methoxyethyl)-
2-pyrrolidone, N- (3-methoxypropyl) -2-
Examples include pyrrolidones such as pyrrolidone, N-benzyl-2-pyrrolidone, and polyvinylpyrrolidone. These water-soluble organic solvents may be used alone or as a mixture.

Among them, ethylene glycol, tetraethylene glycol, glycerin, diethylene glycol, triethylene glycol, polyethylene glycol, (average molecular weight 200, 300, 400, 600
Etc.), polypropylene glycol (average molecular weight 400,
700 and the like) are particularly preferably used as the water-based recording ink of the present invention.

In the aqueous recording ink of the present invention, the amount of propylene glycol monopropyl ether added is 0.1 to 20% by weight, preferably 0.5.
-15% by weight, more preferably 1-10% by weight.
If the addition amount is 0.1% by weight or less, the penetrating power to paper is poor and it is difficult to obtain the quick-drying property of the recording liquid. Further, when the addition amount is 20% by weight or more, the quick-drying property is excellent, but the ink has a high viscosity and tends to adversely affect the ejection stability of the ink.

The addition amount of the water-soluble organic solvent other than propylene glycol monopropyl ether depends on the addition amount of the propylene glycol monopropyl ether, but is usually 0 to 40% by weight, preferably 5 to 30% by weight. Is.

The water-soluble dyes preferably used in the present invention include direct dyes, acid dyes or reactive dyes,
Of these, dyes that have high solubility in water and water-soluble organic solvents and that improve the water resistance and light resistance of recorded images are desirable, and specifically, for example, C.I. I. Direct black 1
7, 19, 22, 32, 51, 56, 62, 71, 7
4, 75, 77, 94, 105, 106, 107, 10
8, 112, 113, 117, 118, 122, 13
2, 133, 146, 154, 159, 162, 16
8, 169, 173, C.I. I. Direct Blue 86,
199, C.I. I. Direct Red 9, C.I. I. Direct Yellow 86, 142, 144, C.I. I. Acid Yellow 23, 42, 49, C.I. I. Acid red 1
4, 34, 35, 37, 249, C.I. I. Acid Blue 7, 9, 249, C.I. I. Reactive Red 24,
35, 111, 114, 174, 180, 184, C.I.
I. Food Black 2, C.I. I. Reactive Yellow 13, 14, 15, 16, 17, 23, 24, 37, 4
2, 75, 76, 77, 79, 114, 115, 11
6 ,. C. I. Reactive Orange 7, 15, 16,
23, 24, 56, 72, 113, C.I. I. Reactive Red 21, 22, 23, 34, 35, 36, 49,
50, 63, 64, 106, 108, 109, 110,
111, 112, 113, 114, 129, C.I. I. Reactive Violet Foot 22, C.I. I. Reactive Brown 21, C.I. I. Reactive blue 19,2
0, 21, 27, 28, 37, 38, 77, 100, 1
01, 123, 147, 148, C.I. I. Reactive Black 5, 14 and the like can be mentioned. These dyes are used alone or as a mixture.

The amount of these water-soluble dyes added is 0.5 to 30% by weight, preferably 1 to 20% by weight in the aqueous recording ink. In the present invention, the weight% of the water-soluble dye
Means a value converted into the dye pure content.

As described above, in the water-based recording ink of the present invention containing the water-soluble dye, the water-soluble organic solvent and water as essential components, the water-soluble dye is 0.5 to 30% by weight, preferably 1 to 30% by weight.
20 wt%, water-soluble organic solvent 0-40 wt%, preferably 5-30 wt%, propylene glycol monopropyl ether 0.1-20 wt%, preferably 0.5-
15% by weight, the balance being water.

The method for preparing the aqueous recording ink of the present invention is not particularly limited, but one or more water-soluble dyes, one or more water-soluble organic solvents and water (usually ion-exchanged water), and further necessary additives are mixed. Then, the aqueous recording ink is prepared by filtering or mixing these water-soluble dyes with a water-soluble organic solvent, filtering once to remove insoluble matter, adding water to this, and further filtering if necessary.

The water-based recording ink of the present invention may optionally contain various additives conventionally used in order to provide better properties. Specifically, for example, penetrants, preservatives, antifungal agents (eg, sodium dehydroacetate, 4-chloro-3-methylphenol, etc.) and other ultraviolet absorbers, viscosity modifiers, anionic or nonionic surfactants, Urea, electric conductivity adjuster, pH buffer,
Examples thereof include a pH adjusting agent, a specific resistance adjusting agent, an infrared absorbing agent, an antioxidant, a chelating agent, a defoaming agent and a surface tension adjusting agent.

[0021]

EFFECTS OF THE INVENTION The aqueous recording ink according to the present invention is excellent in quick-drying of the recording liquid, has less bleeding, and does not cause clogging of nozzles. That is, the propylene glycol monopropyl ether used in the present invention is an excellent penetrant, and by adding this to an aqueous recording ink, an appropriate penetrating force is imparted to the ink to reduce bleeding,
Moreover, there is a synergistic effect that the solubility of the dye is promoted and problems such as nozzle clogging are solved.

As described above, the water-based recording ink according to the present invention is capable of further increasing the speed of the ink jet recording apparatus by obtaining the excellent quick drying property which does not impair the image quality even when recorded on plain paper. became. Further, the water-based recording ink according to the present invention has excellent performance as a recording liquid, so that it can be used not only for ink jet recording but also as various water-based recording inks for writing instruments or recorder stamps.

[0023]

The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In the examples,% means% by weight.

[Composition of Aqueous Recording Ink] Example 1 Direct Black 19 3.0% Polyethylene glycol (# 200) 13.0% Propylene glycol monopropyl ether 3.0% Ion-exchanged water 81.0%

Example 2 Direct Blue 199 4.5% Polyethylene glycol (# 200) 13.0% Propylene glycol monopropyl ether 6.0% Surfynol 465 0.05% (acetylene glycol derivative, manufactured by Nisshin Chemical Co., Ltd.) Ion-exchanged water 76.45%

Example 3 Direct Yellow 144 3.0% Triethylene glycol 13.0% Propylene glycol monopropyl ether 6.0% Ion-exchanged water 78.0%

Example 4 Direct Black 154 3.0% 2-Pyrrolidone 5.0% Dipropylene glycol 5.0% Propylene glycol monopropyl ether 1.5% Ion-exchanged water 85.5%

Example 5 Acid Red 249 4.0% Diethylene glycol 12.0% Propylene glycol monopropyl ether 6.0% Triethanolamine 0.6% Urea 3.0% Ion-exchanged water 74.4%

Example 6 Acid Yellow 23 2.0% Diethylene glycol 13.0% Propylene glycol monopropyl ether 6.0% Urea 1.0% Ion-exchanged water 78.0%

Comparative Example 1 Direct Black 19 3.0% Polyethylene glycol (# 200) 13.0% Ion-exchanged water 84.0%

Comparative Example 2 Direct Black 19 3.0% Polyethylene glycol (# 200) 13.0% Propylene glycol monomethyl ether 3.0% Ion-exchanged water 81.0%

Comparative Example 3 Direct Black 19 3.0% Propylene glycol monoethyl ether 3.0% Polyethylene glycol (# 200) 13.0% Ion-exchanged water 81.0%

Comparative Example 4 Direct Black 19 3.0% Polyethylene glycol (# 200) 13.0% Propylene glycol monobutyl ether 3.0% Ion-exchanged water 81.0%

Comparative Example 5 Direct Blue 199 4.5% Polyethylene glycol (# 200) 13.0% Propylene glycol monomethyl ether 6.0% Surfynol 465 0.05% (acetylene glycol derivative, manufactured by Nisshin Chemical Co., Ltd.) Ion Exchanged water 76.45%

Comparative Example 6 Direct Blue 199 4.5% Polyethylene glycol (# 200) 13.0% Surfynol 465 0.05% (acetylene glycol derivative, manufactured by Nisshin Chemical Co.) Propylene glycol monophenyl ether 6.0% Ion-exchanged water 76.45%

Comparative Example 7 Direct Yellow 144 3.0% Triethylene glycol 13.0% Ion-exchanged water 84.0%

Comparative Example 8 Direct Black 154 3.0% 2-Pyrrolidone 5.0% Dipropylene glycol 5.0% Ion-exchanged water 87.0%

Comparative Example 9 Direct Black 154 3.0% N-Methyl-2-pyrrolidone 10.0% Surfynol 465 0.2% (acetylene glycol derivative, manufactured by Nisshin Chemical Co., Ltd.) deionized water 86.8%

Comparative Example 10 Acid Red 249 4.0% Diethylene glycol 12.0% Triethanolamine 0.6% Urea 3.0% Ion-exchanged water 80.4%

Comparative Example 11 Acid Yellow 23 2.0% Diethylene glycol 13.0% Urea 1.0% Ion-exchanged water 84.0%

The compositions of Examples 1 to 6 and Comparative Examples 1 to 11 were mixed, filtered under pressure with a membrane filter having a pore size of 0.45 μm, and then deaerated using a vacuum pump to prepare inks. . The obtained water-based recording ink was used as an inkjet printer NOVAJetII (ENCAD product: bubble jet method) and MJ-700V2C.
(Epson Corporation product: piezo method) was used to print on the following two types of plain paper, and the following items were evaluated.

Test paper 4024DP paper (manufactured by Xerox Co.) NBS paper (manufactured by Japan Business Supply Co.)

(Printing Quality) Character printing and solid printing were carried out on the test papers, and after standing for 24 hours, bleeding in a single color and a mixed color was evaluated.

Bleed Evaluation Criteria O-There is no bleed. Δ-Bleeding is confirmed. × − has a large blur

(Fast-drying property) A solid test piece of 8 cm × 14 cm was printed on the test paper, and the printing surface was filtered paper (No.
It was wiped off in 2), the permeability was observed by the amount of undried ink flowing out (whiskers) on the test paper, and the quick-drying property was evaluated.

Permeability Evaluation Criteria O--Permeated or almost permeated, and quick drying property is good. Δ-Poor permeability. X-Permeability is considerably poor.

The results of printing with the ink jet printer NOVA JetII (product of ENCAD: bubble jet method) by the above method are shown in Table 1 and MJ-
The results of printing with 700V2C (Epson Corp. product: piezo method) are shown in Table 2.

[0048]

[Table-1] * Ink cannot be prepared due to poor dissolution

[0049]

[Table-2] * Ink cannot be prepared due to poor dissolution

Claims (4)

[Claims] 1. An aqueous recording ink containing a water-soluble dye, a water-soluble organic solvent, and water as essential components, which contains propylene glycol monopropyl ether as a water-soluble organic solvent. 2. The water-soluble organic solvent comprises propylene glycol monopropyl ether and a water-soluble organic solvent other than propylene glycol monopropyl ether.
The water-based recording ink according to item 1. 3. The water-based recording ink according to claim 2, wherein the water-soluble organic solvent other than propylene glycol monopropyl ether is selected from ethylene glycol, tetraethylene glycol, glycerin, diethylene glycol, triethylene glycol, polyethylene glycol or polypropylene glycol. . 4. The aqueous recording ink according to claim 1, which contains 0.1 to 20% by weight of propylene glycol monopropyl ether in the aqueous recording ink. [0001]