JPH05293976A - Ink jet color recording method - Google Patents

Abstract

PURPOSE:To obtain a high-grade image free from blur and whiskers and excellent in color reproducibility even at the time of color recording and at the time of monochromatic recording only of black regardless of the kind of a material to be recorded (plain paper). CONSTITUTION:In an ink jet recording method, color inks containing acetylene glycol and black ink containing 2-15wt.% of polyhydric alcohol and/or a derivative thereof and 1-8wt.% of monohydric alcohol are used to apply recording to sized recording paper. As the color inks, yellow, magenta and cyan color inks having surface tension of 25-40mN/m at 25 deg.C are used and the black ink to be used has surface tension of 40mN/m or more at 25 deg.C.

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 an ink jet color recording method using a plurality of primary color recording liquids, and an ink jet forming a clear color image with high printing quality and high resolution. Regarding a color 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. Due to the demand for higher print quality, the occurrence of bleeding and whiskers on printed materials is small, and high-quality images with excellent color reproducibility due to color mixing are obtained, and as a monochrome printer used only in black. However, it is required to realize sufficiently high-quality recording, but there is still no satisfactory one.

Conventionally, the color inkjet has been improved to obtain a good color image. JP-A-60
-197778 shows that the surface tensions of a plurality of types of color recording liquids having different colors forming a color image are 30 to 60 at 20 ° C.
It is within the range of mN / m and the recording liquids having almost the same surface tension are used. In JP-A-60-197776, plural kinds of color recording liquids having different colors forming a color image are used. The viscosity of each recording liquid is not more than 20 mPa.sec at 25 ° C., and the viscosities of the respective recording liquids are almost uniform. In JP-A-60-197777, a plurality of different colors forming a color image are used. The water content of the various color recording liquids is 20 ~ 90wt%
The time required for fixing each color recording liquid to the recording material and the degree of bleeding are determined by adjusting the physical properties and composition of each color recording liquid, such as using a recording liquid with almost the same water content. A method has been proposed in which all of the color images are equal to each other and balanced as a whole.

However, in these ink jet color recording inks and recording methods, the monochrome print quality of only black is poor in terms of bleeding, whiskers, density, etc. on sized recording paper with high versatility, In addition, because of that, the entire color image will be totally blurred, and it will not be possible to obtain a high-quality color image that is clear and has excellent color reproducibility. Cannot be a sufficient means of. Therefore, when these inks are used, it is the actual situation that a special recording paper with a special coating on the surface is used.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is to prevent bleeding in color recording and black-only monochrome recording, regardless of the type of plain paper.
It is to realize an inkjet color recording method that provides a high-quality image with no whiskers and excellent color reproducibility.

[0006]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that in an ink jet recording method, a color ink containing acetylene glycol and a polyhydric alcohol and / or a derivative thereof. 2 to 1
It was found that high-quality color recording can be obtained even on a sized recording paper by using a black ink containing 5 wt% and 1 to 8 wt% of monohydric alcohol.

Further, yellow, magenta, and cyan are used as color inks, and the surface tension of the color inks of yellow, magenta, and cyan at 25 ° C. is 25 to 40 mN / m, and that of black ink at 25 ° C. Higher quality color recording can be realized by using an ink having a surface tension of 40 mN / m or more.

The present invention will be described in detail. The color ink used in the recording method of the present invention contains at least acetylene glycol, and has a surface tension of 25 to 25 ° C.
40mN / m, black ink contains polyhydric alcohol and / or its derivative 2-15wt% and monohydric alcohol 1-8wt%
It contains the surface tension at 25 ℃ of 40mN / m or more, but when printing with these, it is possible to obtain a high-quality image with clear black and no color blur. It was also found that an image having no bleeding when a black and a color are mixed can be obtained despite the inks having different compositions and surface tensions. That is, the present inventors cannot realize a clear and high-quality image by the conventional method of making the penetrability and physical properties of four recording liquids of yellow, magenta, cyan, and black the same, and black is a contrast of color image quality. , I found that it becomes the point of sharpness. Then, the composition of the black ink and the color ink was changed and various inks were evaluated. As a result, it was found that the combination of the compositions of the present invention was very effective.

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, 98, 100,
101, C.I. I. Direct Yellow 8, 9, 11, 12, 2
7, 28, 29, 33, 35, 39, 41, 44, 5
0, 53, 58, 59, 68, 86, 87, 93, 9
5, 96, 98, 100, 106, 108, 109, 1
10, 130, 132, 142, 144, 161, 16
3, C.I. I. Direct Blue 1, 10, 15, 22, 2
5, 55, 67, 68, 71, 76, 77, 78, 8
0, 84, 86, 87, 90, 98, 106, 108,
109, 151, 156, 158, 159, 160, 1
68, 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, 3
2, 51, 56, 62, 69, 77, 80, 91, 9
4, 97, 108, 112, 113, 114, 117,
118, 121, 122, 125, 132, 146, 1
54, 166, 168, 173, 199, C.I. I. Acid Red 35, 42, 52, 57, 6
2, 80, 82, 111, 114, 118, 119, 1
27, 128, 131, 143, 151, 154, 15
8, 249, 254, 257, 261, 263, 26
6, 289, 299, 301, 305, 336, 33
7, 361, 396, 397, C.I. I. Acid Violet 5, 34, 43, 47,
48, 90, 103, 126, C.I. I. Acid Yellow 17, 19, 23, 25, 3
9, 40, 42, 44, 49, 50, 61, 64, 7
6, 79, 110, 127, 135, 143, 151,
159, 169, 174, 190, 195, 196, 1
97, 199, 218, 219, 222, 227, C.I. I. Acid Blue 9, 25, 40, 41, 62,
72, 76, 78, 80, 82, 92, 106, 11
2, 113, 120, 127: 1, 129, 138, 1
43, 175, 181, 205, 207, 220, 22
1, 230, 232, 247, 258, 260, 26
4, 271, 277, 278, 279, 280, 28
8, 290, 326, C.I. I. Acid Black 7, 24, 29, 48, 5
2: 1, 172, C.I. I. Reactive Red 3, 13, 17, 19, 2
1, 22, 23, 24, 29, 35, 37, 40, 4
1, 43, 45, 49, 55, C.I. I. Reactive Violet 1, 3, 4, 5,
6, 7, 8, 9, 16, 17, 22, 23, 24, 2
6, 27, 33, 34, C.I. I. Reactive Yellow 2, 3, 13, 14, 1
5, 17, 18, 23, 24, 25, 26, 27, 2
9, 35, 37, 41, 42, C.I. I. Reactive Blue 2, 3, 5, 8, 10, 1
3, 14, 15, 17, 18, 19, 21, 25, 2
6, 27, 28, 29, 38, C.I. I. Reactive Black 4, 5, 8, 14, 2
1, 23, 26, 31, 32, 34, C.I. 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, 1
0, 15, 16, 20, 21, 25, 27, 28, 3
5, 37, 39, 40, 48, C.I. I. Basic Yellow 1, 2, 4, 11, 13,
14, 15, 19, 21, 23, 24, 25, 28, 2
9, 32, 36, 39, 40, C.I. I. Basic Blue 1, 3, 5, 7, 9, 22,
26, 41, 45, 46, 47, 54, 57, 60, 6
2, 65, 66, 69, 71, C.I. I. Basic Black 8 and the like.

The preferable addition amount of the above water-soluble dye 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 a long time lapse.

Regarding the recording liquid used in the recording method of the present invention, the liquid medium for dissolving the above-mentioned water-soluble dye is used as a conventional general recording liquid and a medium for ink jet recording ink. 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 Sulpholane, pyrrolidone, N
-Methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 1,5-pentanediol and the like can be mentioned.

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

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,
It 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 colorant.

The preferable amount of the 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 component and its composition range 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 acetylene glycol contained in the color ink is added to obtain the penetrability of the color ink. The amount of the acetylene glycol added is a weight percentage based on the total weight of the recording liquid, preferably 0.01 to 10 wt.
%, More preferably 0.01 to 5 wt%. With the lower limit of the amount used, the dissolution stability of the water-soluble dye and the quick-drying property of the recording liquid become insufficient, and when the amount exceeds the upper limit, the foaming property of the recording liquid becomes large and the printing quality deteriorates, resulting in stable ejection. It also adversely affects sex.

Next, the composition of the black ink will be described. The black ink contains a polyhydric alcohol and / or its derivative and a monohydric alcohol among water-soluble organic solvents. Addition of monohydric alcohol controls bleeding when mixed with color ink.If the addition amount is 1 wt% or less, the occurrence of bleeding in color mixing cannot be suppressed, and if it is 8 wt% or more, it is black. Bleeding occurs as a single substance, so add 1
Within the range of ~ 8wt%. Further, it was found that the addition of polyhydric alcohol and / or its derivative greatly affects the printing quality such as bleeding during color mixing. That is, if the addition amount of the polyhydric alcohol and / or its derivative is 2 wt% or less, bleeding or the like occurs at the time of color mixing, and if it is 15 wt% or more, bleeding occurs in the black simple substance. It is desirable to set it within the range of 15 wt%.

Further, as described in claim 3, the surface tension of the yellow, magenta and cyan color inks is 25 to 40 mN / m at 25 ° C. Within this range, the balance of the color image can be adjusted without significantly changing the permeability.

The surface tension of black ink is 25 ° C.
40mN / m or more. It is more preferably within the range of 40 mN / m to 70 mN / m. If it is out of this range, the wettability, penetrability and quick-drying property of the recording liquid become inadequate, the bleeding at the time of color mixing, whiskers and the like, and the conventional problems in terms of printing quality cannot be solved, and the object of the present invention can be achieved. Disappear.

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; , 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 an inorganic salt of lithium chloride, ammonium chloride or 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 recording liquid used in the recording method of the present invention can be obtained only by mixing the above-mentioned essential components and optional components and dissolving them.

[0025]

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.

(Black Ink 1) C.I. I. Direct Black 19 3% Glycerin 5% Ethanol 5% Water Remaining amount (Black ink 2) C.I. I. Food Black 2 3% Ethylene glycol 5% Methanol 5% Water Remaining amount (Black ink 3) C.I. I. Direct Black 154 3% Diethylene glycol 5% 2-Propanol 5% Water remaining amount (Black ink 4) C.I. I. Direct Black 19 3% Glycerin 5% Water Remaining (Black Ink 5) C.I. I. Food Black 2 3% Glycerin 5% Ethanol 5% Surfynol 82 3% Surfynol TG 0.5% Water Remaining Color ink was prepared by adding each dye to yellow ink, magenta ink, and cyan ink. .. Regarding the composition, the type of dye and the addition amount are
As shown below, the type of liquid medium to be added to each of the inks and the addition amount were the same, and water was added as the remaining amount so that the total amount was 100.

(Color Ink A) Dye Yellow Ink ... C.I. I. Acid Yellow 23 3% magenta ink ... C.I. I. Direct Red 93% Cyan Ink ... C.I. I. Direct Blue 86 3% Liquid medium Diethylene glycol 10% Surfynol 82 3% Surfynol TG 0.5% Water remaining amount (color ink B) Dye yellow ink ... C.I. I. Direct Yellow 86 3% magenta ink ... C.I. I. Acid Red 254 3% cyan ink ... C.I. I. Acid blue 9 3% Liquid medium Triethylene glycol 10% Surfynol 82 3% Surfynol TG 0.5% Water remaining amount (color ink C) Dye yellow ink ... C.I. I. Acid Yellow 23 3% magenta ink ... C.I. I. Acid Red 52 3% Cyan Ink ... C.I. I. Direct Blue 199 3% Liquid medium Diethylene glycol 10% Glycerin 10% Surfynol 82 3% Surfynol TG 0.5% Water remaining amount (color ink D) Dye yellow ink ... C.I. I. Acid Yellow 23 3% magenta ink ... C.I. I. Direct Red 254 3% cyan ink ... C.I. I. Direct Blue 86 3% Liquid medium Diethylene glycol 10% Water Remaining amount (Color ink E) Dye Yellow ink ・ ・ ・ C. I. Direct Yellow 86 3% magenta ink ... C.I. I. Direct Red 93% Cyan Ink ... C.I. I. Direct Blue 199 3% Liquid medium Diethylene glycol 10% Surfynol 82 3% Water Remaining amount Each component of the above ink is mixed, stirred at 60 ° C. for 2 hours and dissolved, and then a 0.8 μm diameter membrane filter (registered trademark of Advantech) is used. ) Was used for pressure filtration at a pressure of ² kg / cm ² to obtain a recording liquid.

Regarding the ink composition thus obtained,
The surface tension at 25 ° C was measured using an HLV-ST type surface tension meter (Kyowa Interface Science registered trademark), and the viscosity at 20 ° C was measured using a B type viscometer (Tokyo Keiki registered trademark) No. 1 rotor. These values are shown in Table 1.

[0029]

[Table 1]

Next, each evaluation item test 1 to 5 will be listed, and the evaluation results using the above inks are shown in Table 2 for Examples and Table 3 for Comparative Examples.

As an example, No. 1 black ink 1 and color ink A No. 2 black ink 1 and color ink B No. 3 black ink 1 and color ink C No. 4 black ink 2 and color ink A No. 5 black Ink 2 and color ink B No. 6 Black ink 2 and color ink C No. 7 Black ink 3 and color ink A No. 8 Black ink 3 and color ink B No. 9 Black ink 3 and color ink C black ink The result evaluated with the combination of color inks is shown.

As a comparative example, No. 10 black ink 4 and color ink A No. 11 black ink 4 and color ink B No. 12 black ink 4 and color ink C No. 13 black ink 5 and color ink A No. 14 black Ink 5 and color ink B No. 15 Black ink 5 and color ink C No. 16 Black ink 1 and color ink D No. 17 Black ink 2 and color ink D No. 18 Black ink 3 and color ink D No. 19 Black Ink 1 and Color Ink E No. 20 Black Ink 2 and Color Ink E No. 21 Black Ink 3 and Color Ink E No. 22 Black Ink 4 and Color Ink D ..

PPC paper (registered trademark of Xerox Co., Ltd.) was manufactured 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), recycled paper (Honshu Paper registered trademark Yamayuri), bond paper (Meade's registered trademark Gilbert Bond 25% cotton paper), fine paper (Oji Paper registered trademark OK fine paper L), fill one line, alphabet letters, etc. It was printed and evaluated in Tests 1 to 3 shown below.

(Test 1) Black character print sample Visual evaluation of print quality.

The evaluation results are classified as follows.

Bleeding and beard are not observed with the naked eye ... ◎ Bleeding and whiskers are slightly seen ... O Bleeding and beard are large, but characters can be recognized. △ Bleeding and whiskers are very large and characters cannot be recognized. × (Test 2) Evaluation of print quality by visually observing a sample when characters are printed by black ink after one line is filled and printed with color ink.

The evaluation results are classified as follows.

Bleeding and beard are not observed with the naked eye .... ◎ Bleeding and beard are slightly seen .... ○ Bleeding and beard are large, but characters can be recognized. △ Bleed and whiskers are very large and characters cannot be recognized. × (Test 3) Visual quality evaluation of images when printed by inkjet color recording using each color ink and black ink.

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.
◎ A slight bleeding is seen in the image with mixed colors, but the color reproducibility is good and the image quality is also good. Inferior in quality and poor in image quality ・ ・ ・ △ Bleed in mixed colors is very large and color reproducibility is poor, resulting in very poor image quality.・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Evaluation results are shown below.

[0041]

[Table 2]

[0042]

[Table 3]

By using the recording method of the present invention, that is, by using the color ink containing acetylene glycol and the black ink containing monohydric alcohol, it is possible to perform monochrome recording at the time of color recording and only black regardless of the kind of recording material (plain paper). A high-quality image with excellent color reproducibility without bleeding or whiskers is sometimes obtained.

[0044]

As described above, according to the ink jet color recording method of the present invention, color reproducibility without bleeding and whiskers is achieved regardless of the type of recording material (plain paper) during color recording and during monochrome recording of black only. An excellent high-quality 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, regardless of the type of recording material (plain paper), since the permeability of the recording liquid is high, 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 (3)

[Claims] 1. An ink jet recording method comprising sizing using a color ink containing acetylene glycol and a black ink containing 2 to 15 wt% of a polyhydric alcohol and / or its derivative and 1 to 8 wt% of a monohydric alcohol. Ink-jet color recording method, which comprises printing on a recording paper that has been printed. 2. The ink jet color recording method according to claim 1, wherein yellow, magenta and cyan are used as the color inks. 3. An ink in which yellow, magenta, and cyan color inks have a surface tension at 25 ° C. of 25 to 40 mN / m, and a black ink has a surface tension at 25 ° C. of 40 mN / m or more is used. The inkjet color recording method according to claim 1, wherein