JPH08193176A - Inkjet recording ink - Google Patents

Abstract

(57) [Summary] [Object] To provide an inkjet recording ink in a color inkjet printing, in which a recorded image has high color development and high quality, and there is no color bleeding in a mixed color and there is no single-color bleeding. [Structure] In the inkjet recording ink, at least (A) 0.2 to 10 Wt% of a coloring agent, and (B) 0.05 to
20 Wt% penetrant, (C) 0.02-0.5 Wt% alginate, (D) 0.5-20 Wt% solid wetting agent material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording ink.

[0002]

2. Description of the Related Art Conventionally, inks of various compositions have been proposed in ink jet recording systems. A recent trend is that bleeding (hereinafter referred to as bleed) that occurs when printed images have high color development when printed on plain paper that is commonly used in offices, etc. A variety of reduced inks have been proposed.

In JP-A-5-194884, a polymer colloid and at least one surfactant having a critical micelle concentration (cmc) or more and a low vapor pressure solvent are added to the ink to reduce bleeding on recording paper. ing.

On the other hand, in JP-A-6-88048,
Use a recording ink in which the added amount of the surfactant is cmc or more with respect to the ink and cmc or less with respect to pure water, and prevent the bleeding between the recording medium and the ink and the bleeding of the color boundary due to the effect of the surfactant. ing.

[0005]

However, the above-mentioned technique has the following problems. That is, the shape of the dots on the recording medium is lacking in the sharpness around the dots, and the edges of the recorded image are blurred because of this.

Further, since the amount of the surfactant added is not less than cmc, the recording ink deeply penetrates into the inside of the paper, so that there is a problem that the coloring property is deteriorated.

Further, there is a concern that the ink may foam when the amount of the surfactant added is more than cmc, and the reliability of the ink still has a problem.

As described above, in general, the quality of recording on plain paper is still insufficient.

Therefore, the object of the present invention is to solve the contradictory problem of color bleeding in mixed colors and bleeding in monochromatic color (if penetration is increased, bleeding such as whiskers occurs due to penetration into paper fibers. Bleeding is liable to occur without being dried, and bleeding is likely to occur. Further, it is an object of the present invention to provide an ink jet recording ink in which a recorded image has high color development and printing quality is sharp and clear.

[0010]

As a result of various studies to achieve the above object, an invention of a recording ink which has a high color development and a high print quality, and which has neither bleeding in mixed colors nor bleeding in a single color Came to.

That is, the present invention is at least (A) 0.
2-10 wt% colorant, (B) penetrant, (C) 0.0
2-0.5 Wt% alginate, (D) 0.5-20
An inkjet recording ink comprising Wt% solid wetting agent (E) water.

The penetrant (B) is a surfactant having a critical micelle concentration (hereinafter referred to as cmc) or less in [I] ink, [II] 1-10 Wt% of monohydric alcohol, [III].
It is an ink for inkjet recording characterized by being a single penetrating agent or a plurality of penetrating agents selected from derivatives of polyhydric alcohols of 0.5 to 5 Wt%.

The recording ink provided in the present invention reduces or eliminates the contradictory problems of color bleeding in mixed colors and bleeding in a single color, and has a characteristic that the recorded image has high color development and the print quality is sharp and clear. I succeeded in finding out and came to invent.

That is, it has been found that the combined use of alginate and a solid wetting agent can greatly improve the contradictory characteristics of color bleeding in monochromatic bleeding and color mixing. Further, it has been found that the permeability also greatly affects the above characteristics.
That is, if the amount of the surfactant added is cmc or more, as in the prior art, the recording ink permeates the paper more than necessary, and the effect of high coloring is diminished.

The penetrant of the present invention is cm for ink.
Preferred penetrability can be obtained by the addition of a surfactant of c or less and also a derivative of 1 to 10 Wt% of a monohydric alcohol and 0.5 to 5 Wt% of a polyhydric alcohol. The effect of the addition of the wetting agent is significantly exhibited.

As the above-mentioned surfactant, anionic,
Any of cationic, amphoteric, and nonionic can be used. Specifically, an alkyl sulfocarboxylate salt,
α-olefin sulfonate, polyoxyethylene alkyl ether acetate, N-acyl amino acid and its salt, N-acyl methyl taurine salt, alkyl sulfate polyoxyalkyl ether sulfate, alkyl sulfate polyoxyethylene alkyl ether phosphate , Rosin acid soap,
Castor oil sulfate, lauryl alcohol sulfate, alkylphenol phosphate, alkyl phosphate, alkylallylsulfonate, diethylsulfosuccinate, diethylhexylsulfosuccinate, dioctylsulfosuccinate, and 2- There are vinyl pyridine attractants, poly 4-vinyl pyridine attractants, and the like. As the amphoteric surfactant, lauryldimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, polyoctylpolyaminoethylglycine and other imidazoline derivatives, Furthermore, polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene alkyl ether, Ether type such as oxyalkylene alkyl ether, polyoxyethylene oleic acid, polyoxyethylene oleic acid S Le, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate,
Ester type such as polyoxyethylene stearate,
2,4,7,9-Tetramethyl-5-decyne-4,7-
Diol, 3,6-dimethyl-4-octyne-3,6-
Acetylene glycols such as diol and 3,5-dimethyl-1-hexyne-3-ol (eg, Nisshin Chemical Surfinol 104, 82, 465, 485, TG, etc.)
and so on. Among them, foaming, a non-ionic surfactant having good reliability is preferable, and especially acetylene glycol,
Ethylene oxide and propylene oxide addition surfactants are preferred. The amount of surfactant added is cmc
If it exceeds, the permeability will remarkably increase, so that it is necessary to use it at a concentration of cmc or less. Monohydric alcohols such as methanol, ethanol and propanol have 1 carbon
To 4 monohydric alcohols are used. Addition amount is 1-10W
The desired permeability is obtained in the t% range. As the polyhydric alcohol derivative, glycol ethers such as triethylene glycol monobutyl ether, propylene glycol monobutyl ether, and dipropylene glycol monobutyl ether can be selected, and among them, butyl ether is preferable. The addition amount is preferably in the range of 0.5 to 5 Wt%.

On the other hand, the wetting agent is generally added in order to prevent clogging, but the solid wetting agent having the above-mentioned effects has a powder or crystalline form at room temperature. A reagent that is solid and highly hygroscopic, is easily soluble in ink and water, and has a function of being wettable by ink.

As the solid wetting agent, urea, hydroxypropyl-β-cyclodextrin, trimethylolethane, trimethylolpropane, caprolactam, etc., as well as monosaccharides and polysaccharides such as sucrose and fructose can be used. . The addition amount is preferably 0.5 to 20 Wt%, and more preferably 1 to 10 Wt%.

Further, these solid wetting agents and glycerin, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, hexylene glycol, polyethylene glycol, polypropylene glycol, 1,3 propanediol, 1,5 pentanediol, etc. High boiling point low volatility polyhydric alcohols and other N-methyl 2-pyrrolidone,
It is also possible to use in combination with a nitrogen-containing organic solvent such as 1,3 dimethylimidazolidinone, monoethanolamine, diethanolamine and triethanolamine.

Examples of the colorant (A) used in the present invention include acid dyes, food dyes, basic dyes, reactive dyes and dispersible dyes. Particularly preferred is C.I. I.
Direct Red 2, 4, 9, 23, 26, 31, 3
9, 62, 63, 72, 75, 76, 79, 80, 8
1, 83, 84, 89, 92, 95, 111, 173,
184, 207, 211, 212, 214, 218, 2
21, 223, 224, 225, 226, 227, 23
2, 233, 240, 241, 242, 243, 24
7, C.I. I. Direct Violet 7, 9, 47, 4
8, 51, 66, 90, 93, 94, 95, 98, 10
0, 101, C.I. I. Direct Yellow 8, 9, 1
1, 12, 27, 28, 29, 33, 35, 39, 4
1, 44, 50, 53, 58, 59, 68, 86, 8
7, 93, 95, 96, 98, 100, 106, 10
8, 109, 110, 130, 132, 142, 14
4, 161, 163, C.I. I. Direct Blue 1, 1
0, 15, 22, 25, 55, 67, 68, 71, 7
6, 77, 78, 80, 84, 86, 87, 90, 9
8, 106, 108, 109, 151, 156, 15
8, 159, 160, 168, 189, 192, 19
3, 194, 199, 200, 201, 202, 20
3, 207, 211, 213, 214, 218, 22
5,229,236,237,244,248,24
9, 251, 252, 264, 270, 280, 28
8, 289, 291, C.I. I. Direct black 9,
17, 19, 22, 32, 51, 56, 62, 69, 7
7, 80, 91, 94, 97, 108, 112, 11
3, 114, 117, 118, 121, 122, 12
5, 132, 146, 154, 166, 168, 17
3, 199, C.I. I. Acid Red 35, 42, 5
2, 57, 62, 80, 82, 111, 114, 11
8, 119, 127, 128, 131, 143, 15
1, 154, 158, 249, 254, 257, 26
1, 263, 266, 289, 299, 301, 30
5, 336, 337, 361, 396, 397, C.I.
I. Acid Violet 5, 34, 43, 47, 4
8, 90, 103, 126, C.I. I. Acid Yellow 17, 19, 23, 25, 39, 40, 42, 44, 4
9, 50, 61, 64, 76, 79, 110, 127,
135, 143, 151, 159, 169, 174, 1
90, 195, 196, 197, 199, 218, 21
9, 222, 227, C.I. I. Acid Blue 9,2
5, 40, 41, 62, 72, 76, 78, 80, 8
2, 92, 106, 112, 113, 120, 127:
1, 129, 138, 143, 175, 181, 20
5, 207, 220, 221, 230, 232, 24
7, 258, 260, 264, 271, 277, 27
8, 279, 280, 288, 290, 326, C.I.
I. Acid Black 7, 24, 29, 48, 52:
1, 172, C.I. I. Reactive Red 3, 13, 1
7, 19, 21, 22, 23, 24, 29, 35, 3
7, 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, 27, 3
3, 34, C.I. I. Reactive Yellow 2, 3, 1
3, 14, 15, 17, 18, 23, 24, 25, 2
6, 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, 27, 2
8, 29, 38, C.I. I. Reactive Black 4,
5, 8, 14, 21, 23, 26, 31, 32, 34,
C. I. Basic Red 12, 13, 14, 15, 1
8, 22, 23, 24, 25, 27, 29, 35, 3
6, 38, 39, 45, 46, C.I. I. Basic Violet 1, 2, 3, 7, 10, 15, 16, 20, 2
1, 25, 27, 28, 35, 37, 39, 40, 4
8, C.I. I. Basic Yellow 1, 2, 4, 11, 1
3, 14, 15, 19, 21, 23, 24, 25, 2
8, 29, 32, 36, 39, 40, C.I. I. Basic Blue 1, 3, 5, 7, 9, 22, 26, 41, 4
5, 46, 47, 54, 57, 60, 62, 65, 6
6, 69, 71, C.I. I. Basic Black 8 and the like can be mentioned. The addition amount of these is determined depending on the type of dye, the type of solvent component, required characteristics, etc., but is added in the range of 0.2 to 10% by weight, preferably 0.5 to 5% by weight, based on the total weight of the ink. Is good.

The components of the ink jet recording ink of the present invention are as described above, but other conventionally known water-soluble organic solvents, various dispersants, viscosity modifiers, optical brighteners, etc. may be added as necessary. You can Examples of these are shown below. A water-soluble natural or synthetic polymer such as cellulose, polyvinylpyrrolidone, polyvinyl alcohol, and a water-soluble resin is used as a viscosity modifier, and the pH is adjusted by a buffer solution.
Examples thereof include regulators and fungicides.

Further, in order to prepare the recording liquid used in the 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 components and then filtering impurities and the like.

The physical properties of the ink are 50 in order to ensure stable ejection from the head and stable ink supply to the head.
It is preferably mPa · s or less, and more preferably 20 mPa · s or less.

[0026]

EXAMPLES The ink jet recording ink of the present invention will be described below.

First, examples of the ink of the present invention will be shown. All units of numerical values of composition ratio are weight percent concentrations.

The compositions of the inks of Examples 1 to 6 and the inks of Comparative Examples 1 to 3 of the present invention are shown in Table 1.
To Table 4 below.

The following abbreviations are used in the compositions of Tables 1 and 2.

TME = trimethylol ethane TMP = trimethylol propane HPβCD = hydroxypropyl-β-cyclodextrin TEGmBE = triethylene glycol monobutyl ether PGmBE = propylene glycol monobutyl ether

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

[Table 3]

[0034]

[Table 4]

Next, a comparative example of the present invention will be described.

Comparative Example 1 is an ink containing no alginate.

Comparative Example 2 is a system containing no solid wetting agent.

Comparative Example 3 is a system in which the amount of penetrant added is large.

Comparative Example 4 is a system in which the added amount of alginate is large.

Comparative Example 5 is a system in which the amount of the solid wetting agent added is large.

The components of the above ink were 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.

For ink jet recording, the discharge nozzle diameter is 30 μm.
m, piezoelectric element drive voltage 25 V, drive frequency 5.5 kHz
z, resolution 360 dots / inch, ink discharge rate 0.0
Using a prototype 48-nozzle inkjet evaluation machine adjusted to 5 μg, PPC paper (Xerox registered trademark PPC paper, Ricoh registered trademark RICOPY 6200), recycled paper (Honshu Paper registered trademark Yamayuri), bond paper (Meade registered trademark Gilbert Bond) The printing evaluation was performed using four types of fine paper (25% cotton paper) and fine paper (Oji Paper's registered trademark OK fine paper L).

Evaluation items Test 1 Effect of preventing bleeding in printing in a single color Characters of 7 colors of YMC, RGB and Bk were printed and the printing quality was evaluated. The evaluation results are classified as follows. ⊚: There is almost no difference in print quality depending on the paper, and no bleeding or whiskers are observed. ◯: There are some differences in print quality depending on the paper, but bleeding,
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.

Test 2 Bleed prevention effect in mixed color printing Bk characters were filled in with YMC and RGB colors to perform printing, and the bleeding of Bk characters in each color was evaluated. The evaluation results are classified as follows. ⊚: There is almost no difference in the printed state depending on the paper, and bleeding and whiskers are not observed. ◯: Although there are some differences in the printed state depending on the paper, bleeding and whiskers are not a concern. Δ: There is a difference in printing state depending on the paper, and bleeding and whiskers are observed depending on the paper. X: There is a difference in the printing state depending on the paper, and bleeding and whiskers are observed on any paper.

Test 3 Improvement of print density The change in print density between the print obtained in Example 1 and Comparative Example 1 is shown as follows. ⊚: OD value improved by 5% or more. ◯: OD value ratio was within 5%. X: The rate of change in OD value decreased by 5% or more.

Test 4 Printing Stability The presence / absence of dot omission and ink splattering during continuous printing at room temperature is observed, and the time until the occurrence of 10 or more times is investigated. The evaluation results are classified as follows. ⊚: Dot omission or ink scattering does not occur 10 times for 48 hours or more. ◯: Dot missing or ink scattering 10 times within 24 to 48 hours. Δ: Dot omission or ink scattering 10 times within 1 to 24 hours. C: Dot omission or ink scattering occurs 10 times or more within 1 hour.

Table 5 shows the above evaluation results.

[0048]

[Table 5]

Next, FIG. 1 shows the state of dissolution of Surfynol 465 presented in this Example and Comparative Example in ink.

The point A across the cmc in the figure is the concentration of Surfynol 465 in Examples 1 and 2. In addition, the point B is Surfynol 46 in Comparative Example 3.
A concentration of 5.

[0051]

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an ink jet recording ink in color ink jet printing, in which a recorded image has high color development and high quality, and there is no color bleeding in a mixed color and no single color bleeding.

[Brief description of drawings]

FIG. 1 is a diagram showing a dissolved state of Surfynol 465 in ink.

Claims (2)

[Claims] 1. At least (A) 0.2-10 wt% colorant, (B) penetrant, (C) 0.02-0.5 wt%
2. An ink for inkjet recording comprising the alginate of (1), (D) 0.5 to 20 wt% of a solid wetting agent (E) water. 2. The penetrant of (B) is a surfactant having a critical micelle concentration or less in [I] ink, and [II] 1 to 10 Wt.
% Monohydric alcohol, [III] 0.5 to 5 Wt% polyhydric alcohol derivative, and one or more penetrants selected from the above.