JPH0692008A - Color inkjet recording method - Google Patents

Abstract

PURPOSE:To obtain a high-quality color image with superior color reproducibility and without blurring or feathering at the recording time in mixed colors while allowing ink to spread uniformly irrespective of the kind of to-be-recorded materials (general papers). CONSTITUTION:According to the color inkjet recording method, a recording paper subjected to sizing is printed with the use of ink of a plurality of colors. The contact angle of the using ink of each color five seconds after the ink is dropped to tone paper is not larger than 40 deg., and the ink includes at least black, yellow, magenta and cyan colors. The difference of the contact angle of the colors of ink is within 10 deg.. Moreover, the ink of each color includes at least acetylene glycol.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a color image, and more particularly to a color ink jet recording method using a plurality of primary color recording liquids, and a color for forming a clear color image with high printing quality and high resolution. The present invention relates to an inkjet recording method.

[0002]

2. Description of the Related Art Generally, since a color printer prints by superimposing each color of yellow, magenta, cyan and black, there is a big problem that inks which are liquids are mixed with each other or flow out in the case of color ink jet recording. I'm holding. Further, due to the demand for higher print quality, it is required that the occurrence of bleeding and whiskers on recorded materials be small, and that high-quality images with excellent color reproducibility due to color mixing be obtained as color images. There is nothing to do.

Conventionally, color inkjet has been improved to obtain a good color image. JP-A-60
-197778 discloses that the surface tension of a plurality of types of color inks that form different colors forming a color image is 20 ° C.
It is within the range of 30 to 60 mN / m, and inks having almost the same surface tension of each ink should be used.
No. 6 discloses that a plurality of types of color inks having different colors forming color images have viscosities of 20 mPa.sec or less at 25 ° C., and the viscosities of the respective inks are almost the same. In Japanese Patent Laid-Open No. 60-197777, the water content of a plurality of types of color inks forming different color images is in the range of 20 to 90wt%, and the water content of each ink is almost the same. A method has been proposed in which the time required for fixing each color ink to the recording material and the degree of bleeding are made equal by making the physical properties and composition of each color ink uniform, such as using the same color ink, so that the color image as a whole is balanced.

However, with these ink jet color recording inks and recording methods, the printing quality at the time of color mixing on a highly versatile sized recording paper is not sufficient in terms of bleeding and color reproducibility. A high-quality color image cannot be obtained because the entire color image is blurred, and there is a difference in how the ink spreads on the paper depending on the type of recording material (plain paper). There was a difference, and it could not be a sufficient means for obtaining high-quality and versatile color recording. Therefore, when these inks are used, the actual situation is to use a special recording paper with a special coating on the surface.

[0005]

Therefore, the object of the present invention is to solve the problems regardless of the type of recording material (plain paper).
An object of the present invention is to realize an ink jet color recording method that provides a high-quality color image with uniform spread of ink and bleeding even in mixed-color recording, which is excellent in color reproducibility without whiskers.

[0006]

SUMMARY OF THE INVENTION The present invention is a color ink jet recording method for recording using a plurality of color inks, and the contact angle of each ink after dropping for 5 seconds on a sized paper is 40. The color inks are black, yellow, magenta, and cyan inks, the difference in contact angle between the inks is 10 degrees or less, and an ink containing at least acetylene glycol is used.

As a result of studying various inks, the present inventors have found that the contact angle becomes a point of print quality of color mixture during color recording, quality of color image and compatibility with plain paper. Then, as a result of evaluating various inks by changing the contact angle of each ink, it was found that the contact angle regulation of the present invention is very effective.

The contact angle of the ink can be controlled by adding a surfactant or a water-soluble organic solvent. Especially acetylene glycol has a great effect,
It is added to control the contact angle of each ink, and the amount of acetylene glycol added is a weight percentage relative to the total weight of the recording liquid, preferably 0.05 to 10 wt.
%, More preferably in the range of 0.05 to 5 wt%. With the lower limit of the amount used, the contact angle exceeds 40 degrees, and when it exceeds the upper limit range, the contact angle of 40 degrees or less can be obtained as desired, but the foaming property of the recording liquid increases and the print quality is also improved. It deteriorates and adversely affects the ejection stability.

The acetylene glycol used in the present invention has an acetylene bond and an alcoholic hydroxyl group, and specific examples thereof include the chemical structures shown below.

[0010]

[Chemical 1]

[0011]

[Chemical 2]

[0012]

[Chemical 3]

[0013]

[Chemical 4]

If the difference in contact angle between the inks is within 10 degrees, bleeding at the time of color mixing and spreading of the ink without whiskers are excellent in uniform color reproducibility regardless of the type of the sized recording paper. A very high quality color image can be obtained.

As the coloring component of the recording liquid used in the recording method of the present invention, direct dye, acid dye, food dye, basic dye, reactive dye, disperse dye, vat dye, soluble vat dye, Any of reactive disperse dyes, oily dyes, and various pigments can be used. Among them, water-soluble dyes are preferably used in view of the performance of the recording liquid, and particularly preferred are C.I. I. Direct Red 2, 4, 9, 23, 26, 3
1, 39, 62, 63, 72, 75, 76, 79, 8
0, 81, 83, 84, 89, 92, 95, 111, 1
73, 184, 207, 211, 212, 214, 21
8, 221, 223, 224, 225, 226, 22
7, 232, 233, 240, 241, 242, 24
3, 247, C.I. I. Direct violet 7, 9,
47, 48, 51, 66, 90, 93, 94, 95, 9
8, 100, 101, C.I. I. Direct Yellow 8,
9, 11, 12, 27, 28, 29, 33, 35, 3
9, 41, 44, 50, 53, 58, 59, 68, 8
6, 87, 93, 95, 96, 98, 100, 106,
108, 109, 110, 130, 132, 142, 1
44, 161, 163, C.I. I. Direct Blue 1,
10, 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 preferable amount of the above water-soluble dye added is 0.3 wt% to 25 wt% in the total amount of the recording liquid, and more preferably 1 wt% to 10 wt%. If it is less than 0.3 wt%, the effect as a colorant is weakened and the density of the obtained image becomes insufficient, and if it exceeds 25 wt%, precipitates are generated in the recording liquid after aging for a long time.

Regarding the recording liquid used in the recording method of the present invention, the liquid medium in which the above-mentioned water-soluble dye is dissolved is used in the conventional general recording liquid and ink jet recording ink medium. Any medium can be used, and pure water such as distilled water or ion-exchanged water and / or a water-soluble organic solvent is preferred. That is, alkyl alcohols having 1 to 5 carbon atoms such as methyl alcohol, ethyl alcohol, n-propyl alcohol and n-butyl alcohol; amides such as dimethylformamide and dimethylacetamide; ketones and keto alcohols such as acetone and diacetone alcohol. Ethers such as tetrahydrofuran and dioxane; alkylene glycols having an alkylene group of 2 to 6 carbon atoms such as ethylene glycol, propylene glycol, triethylene glycol and diethylene glycol; glycerin; polyethylene glycol,
Polyalkylene glycols such as polypropylene glycol; ethylene glycol monomethyl (or ethyl)
Lower monoalkyl ethers of polyhydric alcohols such as ethers, diethylene glycol monomethyl (or ethyl) ether, triethylene glycol monomethyl (or ethyl) ether; lower dialkyl ethers of polyhydric alcohols such as triethylene glycol dimethyl (or ethyl) ether And sulfolane, 2-pyrrolidone, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 1,5-pentanediol and the like.

The above media can be used alone or as a mixture, but the most preferred liquid medium composition is water and at least one water-soluble organic solvent.

Among these many water-soluble organic solvents, polyhydric alcohols such as diethylene glycol and lower alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl (or ethyl) ether are preferable. In polyhydric alcohols, the water in the recording liquid evaporates,
This is particularly preferable because it has a great effect as a wetting agent for preventing the nozzle clogging phenomenon due to the deposition of the coloring agent.

The amount of the above water-soluble organic solvent added is 3 wt% to 80 wt% in the total amount of the recording liquid, and more preferably 3 wt% to 50 wt%.

The water content at this time is determined in a wide range depending on the kind of the above-mentioned solvent components and the composition range thereof depending on the desired characteristics of the recording liquid, but generally 40 wt% to the total amount of the recording liquid. 9
It is 5 wt%, and more preferably in the range of 65 wt% to 95 wt%.

The essential components of the recording liquid used in the recording method of the present invention are as described above, but various conventionally known dispersants, viscosity modifiers, surface tension modifiers, optical brighteners, etc. may be used. It can be added if necessary. Examples of these are shown below.

Water-soluble natural or synthetic polymers such as celluloses, polyvinylpyrrolidone, polyvinyl alcohol, water-soluble resins, etc .; viscosity modifiers diethanolamine, triethanolamines, etc .; surface tension modifiers, and pH modifiers with buffer solutions. , Antifungal agents and the like.

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

The recording liquid used in the recording method of the present invention can be obtained only by mixing and dissolving the above essential components and optional components.

[0027]

EXAMPLES The method of the present invention will be further described below with reference to examples. First, the composition of the ink used in the present invention is shown below. In addition,% is based on weight.

With respect to the composition, the types of dyes and the addition amounts are as shown below, and water was added as the remaining amount so that the total amount was 100.

(Black Ink 1) C.I. I. Direct Black 19 3% Diethylene glycol 10% Compound of Chemical formula 2 3% (Surfynol 82; manufactured by Nissin Chemical) Compound of Chemical formula 3 0.5% (Surfynol TG; manufactured by Nisshin Chemical) Water remaining amount (Black ink 2) C. I. Food Black 2 3% Diethylene glycol 10% Glycerin 10% Compound of chemical formula 0.5% (Surfynol 82; manufactured by Nissin Chemical) Compound of chemical formula 0.1% (Surfynol TG; manufactured by Nisshin Chemical) Water remaining amount (Black ink 3) C.I. I. Direct black 154 3% Diethylene glycol 30% Water remaining amount (black ink 4) C.I. I. Direct Black 19 3% Glycerin 20% Compound of Chemical formula 3 0.03% (Surfynol TG; manufactured by Nisshin Chemical Co., Ltd.) Water remaining amount (yellow ink 1) C.I. I. Acid Yellow 23 3% Diethylene glycol 10% Glycerin 5% Compound 2 of Chemical formula 3% (Surfynol 82; manufactured by Nisshin Chemical) Compound 0.5 of Chemical formula 3 (Surfynol TG; manufactured by Nisshin Chemical) Water remaining amount (yellow Ink 2) C.I. I. Direct Yellow 86 3% Triethylene glycol 10% Compound 2 of chemical formula 0.5% (Surfynol 82; manufactured by Nissin Chemical) Compound 0.1 of chemical formula 3 (Surfynol TG; manufactured by Nisshin Chemical Co., Ltd.) Water remaining amount ( Yellow ink 3) C.I. I. Acid Yellow 23 3% Diethylene glycol 30% Water Remaining (Yellow Ink 4) C.I. I. Direct Yellow 86 3% Diethylene glycol 20% Compound 3 compound 0.03% (Surfynol TG; manufactured by Nisshin Chemical Co., Ltd.) Water remaining amount (magenta ink 1) C.I. I. Acid Red 52 3% Diethylene glycol 10% Glycerin 10% Compound 2 of Chemical formula 3% (Surfynol 82; manufactured by Nissin Chemical) Compound 0.5 of Chemical formula 3 (Surfynol TG; manufactured by Nisshin Chemical) Water remaining amount (magenta) Ink 2) C.I. I. Acid Red 254 3% Triethylene glycol 10% Compound 2 of chemical formula 0.5% (Surfynol 82; manufactured by Nisshin Chemical) Compound 0.1 of chemical formula 3 (Surfynol TG; manufactured by Nisshin Chemical Co., Ltd.) Water remaining amount ( Magenta ink 3) C.I. I. Direct Red 93 3% Diethylene glycol 30% Water remaining amount (magenta ink 4) C.I. I. Acid Red 52 3% Triethylene glycol 20% Compound 3 of Chemical formula 0.03% (Surfynol TG; manufactured by Nisshin Chemical Co., Ltd.) Water remaining amount (cyan ink 1) C.I. I. Acid blue 9 3% Glycerin 5% Ethanol 5% Compound 2 of chemical formula 3% (Surfynol 82; manufactured by Nissin Chemical) Compound 0.5 of chemical formula 3 (Surfynol TG; manufactured by Nisshin Chemical Co., Ltd.) Water remaining amount (cyan Ink 2) C.I. I. Direct Blue 199 3% Diethylene glycol 10% Glycerin 10% Compound of chemical formula 0.5% (Surfynol 82; manufactured by Nissin Chemical) Compound of chemical formula 0.1% (Surfynol TG; manufactured by Nisshin Chemical) Water remaining amount (Cyan ink 3) C.I. I. Direct Blue 86 3% Diethylene glycol 30% Water remaining amount (cyan ink 4) C.I. I. Direct Blue 199
3% Glycerin 20% Compound of Chemical Formula 3 0.03% (Surfynol TG; manufactured by Nissin Chemical Co., Ltd.) Water Remaining amount Each component of the above ink is mixed and stirred at 60 ° C. for 2 hours and dissolved, and then a diameter of 0.8 μm Using the membrane filter of
A recording liquid was obtained by pressure filtration at a pressure of ² kg / cm ² .

Regarding the ink composition thus obtained,
Using a CA-Z type automatic contact angle meter (Kyowa Interface Science registered trademark), using a contact angle 5 seconds after dropping in Ricoh registered trademark RICOPY 6200 and an HLV-ST type surface tensiometer (Kyowa Interface Science registered trademark). And the surface tension at 25 ° C. was measured. This value is shown in Table 1.

[0031]

[Table 1]

Next, each evaluation item test 1 to 3 will be listed, and the evaluation results using each of the above inks are shown in Table 2 for Examples and Comparative Examples.

As an example, No. 1 black ink 1 yellow ink 1 magenta ink 1 cyan ink 1 No. 2 black ink 2 yellow ink 2 magenta ink 2 cyan ink 2 NO. 3 black ink 1 yellow ink 2 magenta ink 1 cyan ink 1 No. 4 Black Ink 1 Yellow Ink 2 Magenta Ink 2 Cyan Ink 1 Evaluation results are shown for each ink combination.

As a comparative example, No. 5 black ink 3 yellow ink 3 magenta ink 3 cyan ink 3 No. 6 black ink 1 yellow ink 2 magenta ink 3 cyan ink 3 NO.7 black ink 3 yellow ink 3 magenta ink 2 cyan ink 2 No. 8 Black Ink 1 Yellow Ink 2 Magenta Ink 3 Cyan Ink 1 No. 9 Black Ink 3 Yellow Ink 2 Magenta Ink 1 Cyan Ink 1 No. 10 Black Ink 4 Yellow Ink 4 Magenta Ink 4 Cyan Ink 4 The following evaluations are performed in combination.

PPC paper (registered trademark of Xerox Co., Ltd.) was used by using a prototype 48-nozzle inkjet evaluation machine adjusted to have a discharge nozzle diameter of 30 μm, a piezoelectric element drive voltage of 80 V, a drive frequency of 3 kHz, a resolution of 360 dots / inch and an ink discharge amount of 0.08 μg. 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) and high-quality paper (Oji Paper's registered trademark OK high-quality paper L) were used to evaluate tests 1 to 3 shown below.

(Test 1) Visual evaluation of print quality of print samples such as alphabet letters in mixed colors using four color inks.

The evaluation results are classified as follows.

Bleeding and whiskers are not observed with the naked eye ... ◎ Blurring and whiskers are slightly seen ... O Bleeding and whiskers are large, but letters can be recognized. △ Bleeding, whiskers were very large and characters could not be recognized. × (Test 2) Visual quality evaluation of images when color printing was performed with 7 colors and image processing using 4 color inks.

The evaluation results are classified as follows.

The image has no bleeding due to mixed colors and has very good color reproducibility and high image quality ... ◎ Although bleeding due to mixed colors is slightly seen in the image, good color reproducibility and good image quality・ ・ ・ ・ ・ ・ ・ ・ ○ Image has large bleeding with mixed colors, poor color reproducibility and poor image quality ・ ・ ・ △ Bleeding with mixed colors is very large The color reproducibility is also poor and the image quality is very poor .... × The evaluation results are shown below.

(Test 3) Using four colors of ink, the spread of the ink on each of the monochromatic and mixed color papers was observed with a microscope as the size of the printed dots and evaluated.

There is no difference in the size of the print dots of each color on each paper regardless of the paper size ... ◎ The diameter of the print dots of each color on each paper differs slightly depending on the paper.・ ・ ・ ・ ・ ・ ・ ・ ・ ○ The diameter of the print dots of each color on each paper varies greatly depending on the paper.

[0043]

[Table 2]

The recording method of the present invention, that is, by using an ink in which the contact angle of each ink is 40 degrees or less after 5 seconds from sizing paper, regardless of the type of recording material (plain paper) In addition, the ink spreads uniformly and bleeds during mixed color recording, and a high-quality color image with no whiskers and excellent in color reproducibility can be obtained.

[0045]

As described above, according to the ink jet color recording method of the present invention, regardless of the type of recording material (plain paper), the ink spreads uniformly, and bleeding does not occur in mixed color recording and there is no whisker color reproducibility. An excellent high-quality color image can be obtained.

Therefore, it is not necessary to select the type of recording material (plain paper), and it is not necessary to use expensive special paper or special paper, which leads to low running cost.

Further, according to the present invention, since the permeability of the recording liquid is high regardless of the kind of the recording material (plain paper), the abrasion resistance,
There is also an effect that it is possible to provide a method which is excellent in quick-drying property and therefore does not require mechanical cost increase of a fixing mechanism and the like, and can realize cost reduction of a recording apparatus.

Claims (4)

[Claims] 1. A color ink jet recording method for recording using a plurality of color inks, wherein an ink having a contact angle of 40 degrees or less after 5 seconds from dropping on a sized paper is used. And a color ink jet recording method. 2. At least black, yellow, magenta, and cyan inks are used.
The color inkjet recording method described. 3. The color inkjet recording method according to claim 1, wherein the difference in contact angle between the inks is within 10 degrees. 4. The color ink jet recording method according to claim 1, wherein each ink contains at least acetylene glycol.