JPH09279071A - Ink for ink jet recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain ink for ink jet recording which is excellent in quickly drying properties and print quality and hardly corrode members of an ink jet apparatus by specifying the compounding ratios of a hydrophilic high-b.p. low- volatility solvent and diethylene glycol monobutyl ether and/or triethylene glycol monobutyl ether. SOLUTION: This ink contains 0.5-1wt.% acetylene glycol represented by formula I (wherein R1 to R4 are each a 1-6C alkyl; and m+n is 0-20). The compounding ratio of the solvent to diethylene glycol monobutyl ether and/or triethylene glycol monobutyl ether is (2:3)-(3:1), and the amt. of the latter ingredient compounded is 7-10wt.%. The solvent at least contains glycerin, and ethylene glycol, diethylene glycol, etc., can also be used. A dye is added usually in an amt. of 0.2-15wt.% of ink. The viscosity of the ink is pref. 50MPa.s or lower in terms of the stable delivery from and the stable supply to the head.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an ink used in an inkjet recording method.

[0002]

2. Description of the Related Art Conventionally, an ink in which a dye is dissolved in water has predominantly been used as an ink used in an ink jet recording method (hereinafter referred to as an aqueous ink). As the water-based ink, those in which various water-soluble dyes are dissolved in water and various additives are added as necessary are currently used. However, conventional water-based inks are slow to dry after printing, and the print quality on plain paper is not sufficiently satisfactory.
Particularly, in the case of color recording, when dots of different colors are adjacent to each other, it is difficult to obtain a sharp image because the colors are mixed on the paper. Therefore, in JP-A-55-29546 and JP-A-63-139964, inks containing a water-soluble organic solvent or a surfactant are used as a method for increasing the penetrability into paper in order to provide quick drying. It has been reported, and a method of adding a base to dissolve the sizing agent is
JP-A-53-111606 and JP-A-56-1333
No. 76 publication. However, these inks have insufficient penetrability and quick-drying property when the inks are overlaid, and there is still a problem in terms of image deterioration due to color mixing and bleeding. In order to solve these problems, in US Pat. No. 5,196,056, diethylene glycol monobutyl ether is added in an amount of 1.5 to 10
wt% and acetylene glycol 1 to 3 wt%, and a moisturizer together with acetylene glycol 10 wt%
% Or less is included to improve the quick-drying property and prevent color mixture bleeding.

[0003]

However, when the above ink is used, the head member, the ink supply / waste liquid member, and the like are erosive (hereinafter referred to as “member erosiveness”).
There were problems such as swelling / dissolution of the member and generation of foreign matter in the ink. Therefore, the present invention solves these problems, and an object thereof is to provide an inkjet recording ink which is excellent in quick-drying property, excellent in printing quality, and has less erosion to a head member, an ink supply / waste liquid member and the like. To provide.

[0004]

The present invention comprises at least water,
An ink containing a dye, a hydrophilic high-boiling point low volatile solvent, diethylene glycol monobutyl ether and / or triethylene glycol monobutyl ether and acetylene glycol having a structure represented by the following general formula, wherein the hydrophilic high-boiling point low volatile solvent and diethylene glycol The inkjet recording ink is characterized in that the addition ratio of monobutyl ether and / or triethylene glycol monobutyl ether is 2: 3 to 3: 1.

[0005]

Embedded image

Further, it contains 7 to 10 wt% of diethylene glycol monobutyl ether and / or triethylene glycol monobutyl ether, and 0.5 to 1 wt% of acetylene glycol having the structure shown in the above general formula.
It is characterized by including. Further, the hydrophilic high boiling point low volatility solvent contains at least glycerin.

The inventors of the present invention have conducted studies to realize high print quality and improve the erosion of the head member, the ink supply, and the waste liquid member. Acetylene glycol 0.5 to 1
An ink containing 1 wt% of a hydrophilic high boiling point low volatility solvent and diethylene glycol monobutyl ether and / or triethylene glycol monobutyl ether 2: 3.
It was found that print quality and erosion can be satisfied by adding in the range of up to 3: 1. If the ratio of the added amount is less than 2: 3, the erosion is large especially in the situation where the ink evaporates, and if it exceeds 3: 1, the bleeding and the bleeding between the colors become large and the print quality cannot be satisfied. . It was also confirmed that the inclusion of glycerin as the hydrophilic high-boiling point low-volatile solvent is more effective against erosion. The addition amount of diethylene glycol monobutyl ether and / or triethylene glycol monobutyl ether is 1
If it exceeds 0 wt%, there is a possibility of eroding the member due to long-term contact. Further, if the addition amount is less than 7 wt%,
The solubility of acetylene glycol having the above structure is lowered, and the print quality is lowered. Therefore, the addition amount of triethylene glycol monobutyl ether and / or triethylene glycol monobutyl ether is 7 to 10 wt%.
It is preferred that In addition, the amount of acetylene glycol added is 0.5 to 1 wt% in order to satisfy quick drying and bleeding.
%. Specific examples of acetylene glycol include Olfine STG and Olfine E1010.
(Nissin Chemical Co., Ltd.)

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the constitution of the ink for ink jet recording of the present invention will be described in detail.

Conventionally, water has been mainly used as the ink solvent because of its low viscosity, excellent safety, easy handling, low cost, and no odor. As the ink material, pure water or ultrapure water that has undergone a purification process such as ion exchange or distillation is desirable.

As the coloring component of the ink used in the present invention, a direct dye, an acid dye, an edible dye, a basic dye, a reactive dye, a disperse dye, a vat dye, a soluble vat dye, a reactive disperse dye, an oil dye. Among these, water-soluble dyes are preferably used in view of the performance of the recording liquid, and particularly preferable are C.I. I. Direct Red 2, 4,
9, 23, 26, 31, 39, 62, 63, 72, 7
5, 76, 79, 80, 81, 83, 84, 89, 9
2, 95, 111, 173, 184, 207, 211,
212, 214, 218, 221, 223, 224, 2
25, 226, 227, 232, 233, 240, 24
1, 242, 243, 247, C.I. I. Direct Violet 7, 9, 47, 48, 51, 66, 90, 9
3, 94, 95, 98, 100, 101, C.I. I. Direct Yellow 8, 9, 11, 12, 27, 28, 2
9, 33, 35, 39, 41, 44, 50, 53, 5
8, 59, 68, 86, 87, 93, 95, 96, 9
8, 100, 106, 108, 109, 110, 13
0, 132, 142, 144, 161, 163, C.I.
I. Direct Blue 1, 10, 15, 22, 25, 5
5, 67, 68, 71, 76, 77, 78, 80, 8
4, 86, 87, 90, 98, 106, 108, 10
9, 151, 156, 158, 159, 160, 16
8, 189, 192, 193, 194, 199, 20
0, 201, 202, 203, 207, 211, 21
3, 214, 218, 225, 229, 236, 23
7, 244, 248, 249, 251, 252, 26
4, 270, 280, 288, 289, 291, C.I.
I. Direct Black 9, 17, 19, 22, 32,
51, 56, 62, 69, 77, 80, 91, 94, 9
7, 108, 112, 113, 114, 117, 11
8, 121, 122, 125, 132, 146, 15
4, 166, 168, 173, 199, C.I. I. Acid Red 35, 42, 52, 57, 62, 80, 82,
111, 114, 118, 119, 127, 128, 1
31, 143, 151, 154, 158, 249, 25
4, 257, 261, 263, 266, 289, 29
9, 301, 305, 336, 337, 361, 39
6, 397, C.I. I. Acid Violet 5, 34,
43, 47, 48, 90, 103, 126, C.I. I. Acid Yellow 17, 19, 23, 25, 39, 40,
42, 44, 49, 50, 61, 64, 76, 79, 1
10, 127, 135, 143, 151, 159, 16
9, 174, 190, 195, 196, 197, 19
9, 218, 219, 222, 227, C.I. I. Acid Blue 9, 25, 40, 41, 62, 72, 76, 7
8, 80, 82, 92, 106, 112, 113, 12
0, 127: 1, 129, 138, 143, 175, 1
81, 205, 207, 220, 221, 230, 23
2, 247, 258, 260, 264, 271, 27
7, 278, 279, 280, 288, 290, 32
6, C.I. I. Acid Black 7, 24, 29, 48,
52: 1, 172, C.I. I. Reactive Red 3,1
3, 17, 19, 21, 22, 23, 24, 29, 3
5, 37, 40, 41, 43, 45, 49, 55, C.I.
I. Reactive Violet 1, 3, 4, 5, 6,
7, 8, 9, 16, 17, 22, 23, 24, 26, 2
7, 33, 34, C.I. I. Reactive Yellow 2,
3, 13, 14, 15, 17, 18, 23, 24, 2
5, 26, 27, 29, 35, 37, 41, 42, C.I.
I. Reactive Blue 2, 3, 5, 8, 10, 13,
14, 15, 17, 18, 19, 21, 25, 26, 2
7, 28, 29, 38, C.I. I. Reactive Black 4, 5, 8, 14, 21, 23, 26, 31, 32, 3
4, C.I. I. Basic Red 12, 13, 14, 1
5, 18, 22, 23, 24, 25, 27, 29, 3
5, 36, 38, 39, 45, 46, C.I. I. Basic Violet 1, 2, 3, 7, 10, 15, 16, 2
0, 21, 25, 27, 28, 35, 37, 39, 4
0, 48, C.I. I. Basic Yellow 1, 2, 4, 1
1, 13, 14, 15, 19, 21, 23, 24, 2
5, 28, 29, 32, 36, 39, 40, C.I. I. Basic Blue 1, 3, 5, 7, 9, 22, 26, 4
1, 45, 46, 47, 54, 57, 60, 62, 6
5, 66, 69, 71, C.I. I. Basic Black 8 and the like can be mentioned.

The addition amount of these dyes is determined depending on the kind of the dye, the kind of the solvent component, the characteristics required for the ink, etc., but is generally 0.2 with respect to the total weight of the ink.
The range of -15 wt%, preferably 0.5-10 wt% is good.

Examples of the hydrophilic high boiling point low volatility solvent used in the present invention include glycerin, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, hexylene glycol, polyethylene glycol and polypropylene glycol. Low volatility polyhydric alcohols, and
Urea and saccharides are used, other N-methyl-2pyrrolidone,
1,3-dimethylimidazolidinone, monoethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, diethanolamine, Nn
-A water-soluble organic solvent such as a nitrogen-containing organic solvent such as butyldiethanolamine, triisopropanolamine and triethanolamine can be added within a range that does not cause bleeding in printing. Of these, diethylene glycol and glycerin are preferable. It is well known that these hydrophilic high-boiling point low-volatile solvents are added as a moisturizing agent for preventing clogging, etc., but the maximum effect as an essential component of the present invention is to alleviate erosion of members. is there. In particular, when a volatile component such as water evaporates in the head, the ink supply path, or the like due to an abnormal situation such as a failure of a printing device, the corrosiveness of diethylene glycol monobutyl ether and / or triethylene glycol monobutyl ether is reduced. Although the essential components of the ink jet recording ink of the present invention are as described above, other conventionally known various dispersants,
Viscosity modifiers, optical brighteners and the like can be added as necessary. Examples of these are shown below.

Water-soluble natural or synthetic polymers such as celluloses, polyvinylpyrrolidone, polyvinyl alcohol, and water-soluble resins; viscosity modifiers; and pH modifiers with a buffer solution, antifungal agents and the like. Other examples include corrosion inhibitors for water repellent treatment and the like.

In order to prepare a recording liquid used in an ink jet recording method of the type in which the recording liquid is charged,
A specific resistance adjusting agent such as inorganic salts of lithium chloride, ammonium chloride and sodium chloride is added.

When applied to an ink jet recording method of the type in which a recording liquid is ejected by the action of thermal energy, thermal physical property values (evaporation heat, boiling point, melting point, specific heat,
Thermal expansion coefficient, thermal conductivity, etc.) may be adjusted.

The ink jet recording ink of the present invention comprises
It is obtained by mixing and dissolving the above-mentioned essential components and optional components, and filtering impurities.

As for the physical properties of the ink, in order to ensure stable ejection from the head and stable ink supply to the head, 50
It is preferably mPa · s or less, and more preferably 20 mPa · s or less. In each of the ink examples described below, the viscosity was adjusted to this range.

[0018]

EXAMPLES Examples of the ink jet recording ink of the present invention will be described below. The unit of the numerical value of the composition ratio is wt%.

Table 1 shows the ink compositions of Examples 1 to 8 of the present invention and Comparative Examples 1 to 4.

[0020]

[Table 1]

The compositions of Examples 1 to 8 are ink compositions in which the addition ratio of the hydrophilic high boiling point low volatility solvent to the diethylene glycol monobutyl ether and triethylene glycol monobutyl ether is 2: 3 to 3: 1. is there.
Comparative Examples 1 to 4 are ink compositions having the compositions of Examples 1 to 4 in which the addition ratio of the hydrophilic high boiling point low volatile solvent and diethylene glycol monobutyl ether and / or triethylene glycol monobutyl ether is outside the scope of the present invention.

The components of the above ink are mixed and mixed at 60 ° C. for 2 hours.
After stirring for an hour, a 0.8 μm diameter membrane filter was used and pressure filtration was performed at a pressure of 2 kg / cm 2 to obtain an ink.

PPC paper (registered by Xerox Co., Ltd.) was used by using a trial color ink jet evaluation machine adjusted to have a discharge nozzle diameter of 30 μm, a piezoelectric element drive voltage of 20 V, a drive frequency of 5.5 kHz, a resolution of 360 dots / inch, and an ink discharge amount of 0.05 μg. Trademark PPC paper, RIC registered trademark RIC
OPY6200), recycled paper (Yamayuri registered trademark of Honshu Paper Co., Ltd.), bond paper (Gilbert Bond 2 registered trademark of Mead)
5% cotton paper), high-quality paper (Oji Paper's registered trademark OK high-quality paper L) was filled with 1 line (hereinafter referred to as solid printing), alphabet letters and the like were printed.

The evaluation of each ink was carried out on the following evaluation items.

Evaluation items A. Evaluation of quick-drying property Each recording paper is pressed against a solid print portion with a pressure of 200 g / cm @ 2, and the time until ink transfer does not occur is measured (printing was performed for both single color and two-color overlapping). The evaluation results are classified as follows. A: No ink transfer is observed in less than 1 second. Good: No ink transfer is observed in 1 to 2 seconds. Δ: Ink transfer is not observed in 2 to 5 seconds. X: Ink transfer is observed even for 5 seconds or more.

B. Evaluation of print quality <Evaluation of single color print> Print alphabet letters and visually observe the occurrence of bleeding and whiskers. The evaluation result is
It was classified as follows. ⊚: There is almost no difference in print quality depending on the paper, and no bleeding or whiskers are observed. ：: There is some difference in printing quality between papers.
I don't care about the beard. Δ: There is a difference in print quality depending on the paper, and bleeding and whiskers are observed depending on the paper. X: There is a difference in print quality depending on the paper, and bleeding and whiskers are observed on any paper.

<Evaluation of Mixed Color Printing> Examples 1-4 and 5
-8 and Comparative Example 1-4 are color sets, and yellow, cyan, magenta, red, green, blue,
Black solids are printed so that they are adjacent to each other, and the seepage of each color is visually observed. The evaluation results are classified as follows. ⊚: There is almost no difference in print quality depending on the paper, and color mixture bleeding is not observed. ◯: Although there are some differences in print quality depending on the paper, bleeding of mixed colors is not a concern. Δ: There is a difference in print quality depending on the paper, and mixed color bleeding is observed depending on the paper. X: There is a difference in print quality depending on the paper, and color bleeding is observed on any paper.

C. Evaluation of member erosion (C-, C-) Head member that may come into contact with ink and supply /
The waste liquid member is placed in a closed container and dipped in ink. After the ink is dipped, the liquid waste member is left open at 40 ° C. for 1 month, and then the change in weight and the change in appearance are observed. The evaluation results are classified as follows. ⊚: The weight change of each member is within ± 5%, and there is almost no change in appearance. ◯: The change in weight of each member is within ± 10%, and there is almost no change in appearance. Δ: The weight change of each member exceeds ± 10%, but there is almost no change in appearance. X: The weight change of each member exceeds ± 10%, and swelling,
Table 2 shows the evaluation results of Examples 1 to 8 and Comparative Examples 1 to 4 of the present invention in which dissolution has occurred.

[0029]

[Table 2]

According to the evaluation result of each evaluation item, Example 1
-The ink composition of Example 8 was excellent in quick-drying property, print quality, and member erosion property.

Also in Comparative Examples 1 to 4, when A to C were evaluated in the same manner as in the Examples, quick drying property, print quality,
Satisfactory results were not obtained for either of these and the erodibility of the members.

[0032]

As described above, according to the ink composition of the present invention, the ink used in the ink jet recording method has an effect of being excellent in quick-drying property, print quality and member erosion.

Claims (3)

[Claims] 1. An ink comprising at least water, a dye, a hydrophilic high-boiling point low-volatile solvent, diethylene glycol monobutyl ether and / or triethylene glycol monobutyl ether and acetylene glycol having a structure represented by the following general formula, wherein the ink is hydrophilic. An inkjet recording ink, wherein the addition ratio of the high-boiling point low-volatile solvent and diethylene glycol monobutyl ether and / or triethylene glycol monobutyl ether is 2: 3 to 3: 1. Embedded image 2. A diethylene glycol monobutyl ether and / or triethylene glycol monobutyl ether is contained in an amount of 7 to 10% by weight, and acetylene glycol having the structure represented by the above general formula is included in an amount of 0.5 to 1% by weight. The ink for inkjet recording described. 3. The ink jet recording ink according to claim 1, wherein the hydrophilic high-boiling point low-volatile solvent contains at least glycerin.