JPH08216503A - Ink jet recording method - Google Patents

Abstract

PURPOSE: To record an image generating no deterioration even under a high humidity condition on a recording medium having an ink absorbing layer using ink containing a water-soluble dye containing a sulfone group and/or a carboxyl group in its structure, hexylene glycol and specific polyhydric alcohol. CONSTITUTION: Required ink containing a water-soluble dye having a sulfone group and/or a carboxyl group in its structure and further containing hexylene glycol (a) and polyhydric alcohol (b) with a b.p. at 760mmHg or less of below 220 deg.C and vapor pressure at 20 deg.C of 0.01mmHg or less and/or polyhydric alcohol (c) with a b.p. at 760mmHg or less of 220 deg.C or higher and vapor pressure at 20 deg.C of below 0.01mmHg is prepared. In this case, the total amt. of polyhydric alcohols (a)-(c) in ink is set to 10-30wt.% and the wt. ratio (b+c/a) of polyhydric alcohols (b), (c) and hexylene glycol (a) in ink is set to 2-4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet recording method for forming a recorded image on a recording medium by ejecting ink droplets, and more particularly to a recording liquid and a recording medium.

[0002]

2. Description of the Related Art Although an ink jet recording system has advantages such as quietness during operation and high resolution, it has long been said that colorization is easy as a particularly remarkable advantage. In recent years, with the advent of image processing software in the field of personal computers, color image processing has been generally performed, and along with this, colorization of printers, which are peripheral devices, has been rapidly progressing.

A color ink jet printer forms a color image by recording yellow, magenta, cyan and black inks individually or in combination of two or more kinds on a recording medium and has been commercialized by various companies in recent years. Color inkjet printers must meet the basic characteristics such as ink ejection stability and nozzle clogging required for monochrome inkjet printers, but in addition, high-quality color images with excellent color reproducibility can be obtained. Output required. In order to realize a high-quality color image, a high-quality color ink excellent in color development and color reproducibility and a high-quality recording medium such as inkjet recording paper are required.

Color ink jet inks are generally composed of a water-soluble color dye, a water-soluble organic solvent, and water, and various high-quality color inks have been proposed so far. Further, as a recording medium excellent in color developability and color reproducibility that maximizes the performance of these color inks, as described in JP-A-2-276670, porous alumina water on a substrate is used. A recording medium provided with a Japanese layer and having good ink absorbability is known. This recording medium has a high ink absorbency and an excellent transparency, but since the adsorbability is good, the recorded image may be deteriorated due to the influence of humidity in the air. . Japanese Patent Laid-Open No. 4-
Japanese Patent No. 267180 proposes a recording sheet having a plurality of alumina hydrate layers, each of which has a pore radius increasing from the substrate in the thickness direction. Using this method, when using multiple dyes in color recording,
It is said that it is possible to provide a recording sheet that can effectively absorb and fix each dye, has good color reproducibility, and does not deteriorate a recorded image even under high humidity.

[0005]

As a cause of deterioration of a recorded image under high humidity, there may be a case of a recording medium having an ink absorbing layer and a case of a hygroscopic property of ink used for recording. The former is JP-A-4-267180.
Although it can be improved by the method described in the publication, the cost of the recording medium increases and a cost problem arises. Therefore, in order to realize high quality recording under high humidity, matching between the ink composition and the recording medium is important. According to the present invention, even if an ink containing a water-soluble dye having a sulfone group and / or a carboxyl group in its structure is recorded on a recording medium having an ink absorbing layer composed of porous alumina particles, the humidity in the air It is an object of the present invention to provide an inkjet recording method which is not affected by the above and does not cause deterioration of a recorded image.

[0006]

As a result of various studies to achieve the above object, the present inventors have found that an ink containing a water-soluble dye having a sulfone group and / or a carboxyl group in its structure, The inventors have found a recording method in which printing deterioration does not occur even if recording is performed on a recording medium having an ink absorption layer composed of porous alumina particles, and the present invention is as follows.

That is, it contains a water-soluble dye having a sulfone group and / or a carboxyl group in its structure, (a)
An ink characterized by containing hexylene glycol and (b) component or (c) component of the polyhydric alcohols shown in (b) and (c) below, or (b) component and (c) component at the same time. This is the inkjet recording method used.

(B) The boiling point is 220 under 760 mmHg.
A polyhydric alcohol having a vapor pressure of 0.01 mmHg or more at 20 ° C. or lower.

(C) The boiling point is 220 under 760 mmHg.
A polyhydric alcohol having a vapor pressure of 0.01 mmHg or less at 20 ° C. or higher.

The total amount of the polyhydric alcohols (a), (b) and (c) contained in the ink is 10 to 30% by weight, and the polyhydric alcohols (b) and (c) and (a) are used. ) The weight ratio of hexylene glycol is {(b) + (c)} /
(A) = 2 to 4 is an inkjet recording method using an ink.

An ink jet recording method using an ink is characterized in that the pH of the ink at 20 ° C. is 7.0 or more.

A recording medium having an ink absorbing layer composed of porous alumina particles, or
It is an inkjet recording method for recording on a recording medium having the ink absorbing layer and having a pH of the recording medium at 20 ° C. of 7.0 or less.

The dye used in the present invention has a sulfone group and / or a carboxyl group in its structure and is preferably used in the form of an alkali metal, ammonium salt or substituted ammonium salt.

As the water-soluble organic solvent used in the present invention, polyhydric alcohols such as ethylene glycol, diethylene glycol and glycerin, ethylene glycol monomethyl ether, diethylene glycol monobutyl ether,
Ethers of polyhydric alcohols such as triethylene glycol monobutyl ether, formamide, dimethylformamide, 1,3-dimethyl-2-imidazolidinone, 2
Examples thereof include nitrogen-containing solvents such as -pyrrolidone and N-methyl-2-pyrrolidone, and sulfur-containing solvents such as thiodiglycol and dimethyl sulfoxide. These solvents may be used alone or in combination of two or more kinds. Further, in the present invention, additives such as antiseptics, rust preventives, surfactants and chelating agents may be used if necessary.

The polyhydric alcohol as the component (b) used in the present invention includes ethylene glycol, dipropylene glycol, tetraethylene glycol and the like, and ethylene glycol is preferable. Examples of the polyhydric alcohol as the component (c) include diethylene glycol, triethylene glycol, 1,5 pentanediol and glycerin, and ethylene glycol and glycerin are preferable.

Further, in the present invention, the total amount of polyhydric alcohol contained in the ink is preferably in the range of 10 to 30% by weight, and if the content is less than this, the moisture retention of the ink is lowered and the nozzle clogging is caused. If it is more than this, the hygroscopicity of the ink becomes high, and the recorded image is deteriorated due to the influence of humidity. The weight ratio of (a) hexylene glycol to (b) and (c) polyhydric alcohol is {(b)
+ (C)} / (a) = 2 to 4 is preferable, and if the weight ratio is smaller than this, the moisture retention of the ink is lowered, the nozzle clogging and the ink ejection stability are deteriorated, and the weight ratio is above. When it is larger than the range of, the ink hygroscopicity becomes high,
The recorded image deteriorates due to the influence of humidity.

[0017]

EXAMPLES The present invention will be described below with reference to specific examples and comparative examples.

In the dyes used in the following Examples and Comparative Examples, Dye I is a compound represented by Structural Formula (I), Dye II is a compound represented by Structural Formula (II), and Dye III.
Is a compound represented by the structural formula (III).

[0019]

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[0020]

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[0021]

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Next, Tables 1 and 2 show the ink compositions of Examples and Comparative Examples. Pure water is added to the ink composition so that the total amount becomes 100, and the ratios shown below are all on a weight basis.

[0023]

[Table 1]

[0024]

[Table 2]

In the table, Proxel XL-
2 is a preservative (made by ZENECA), and Surfynol 465 is a surfactant (made by Nissin Chemical).

The following evaluations were performed using the inks of Examples and Comparative Examples obtained in Tables 1 and 2. In addition, MJ-700V2C (made by Seiko Epson Corporation) was used as an evaluation machine for the following evaluations.

Test 1 Nozzle recoverability After ink was set in the printer, printing was performed and it was confirmed that ink was ejected from all nozzles, the head was removed, and ink supply and capping were not performed.
It was left in an environment of 0 ° C. for 7 days. After standing, the head was attached to the printer, and the number of cleaning operations required until ink was supplied and all nozzles ejected was evaluated according to the following criteria. ◯: 2 times or less, Δ: 3 to 4 times, ×: 5 times or more.

Test 2 Evaluation of recorded image under high humidity After the ink was set in the printer, MJ-700V2
Print a solid pattern with white parts on the C gloss film. After printing, the plate was left at room temperature for 15 minutes, and then left in an environment having an air temperature of 40 ° C. and a humidity of 90% for 2 hours. The printed sample after standing was visually evaluated for occurrence of ink bleeding in the white part. ◯: No ink bleeding, ×: Ink bleeding

Test 3 pH Measurement The pH of each ink was measured at a liquid temperature of the ink of 20 ° C.
For the pH measurement, an ion meter N-8 manufactured by Horiba Ltd. was used.

Test 4 Color developability when printed on a recording medium having pH <7.0 MJ-700V2C dedicated gloss film (pH = 4.5,
The color development when a color ink having a pH of <7.0 and a pH of> 7.0 was printed at 20 ° C. was visually evaluated. In addition, pH measurement of glossy film for exclusive use of inkjet is JIS-P-8
The pH meter used in Test 3 was used for the pH measurement. ◯: Vivid color, X: Dull color.

Table 3 shows the results of tests 1 to 4.

[0032]

[Table 3]

As described above, when the ink jet recording method of the present invention is used, good print quality can be realized without being affected by humidity even under high humidity.

[0034]

According to the present invention, an ink containing a water-soluble dye having a sulfone group and / or a carboxyl group in its structure and containing hexylene glycol as an essential component is composed of porous alumina particles. By recording on a recording medium with an ink absorption layer, images with high print quality can be realized even under high humidity without being affected by humidity in the air, and ink ejection stability, clogging, and color development are excellent. An inkjet recording method can be provided.

Claims (3)

[Claims] 1. A water-soluble dye having a sulfone group and / or a carboxyl group in its structure, wherein (a) hexylene glycol and (b) component of polyhydric alcohols shown in (b) and (c) below: An ink jet recording method comprising recording an ink containing the component (c) or the component (b) and the component (c) at the same time on a recording medium having an ink absorbing layer composed of porous alumina particles. (B) A polyhydric alcohol having a boiling point under 760 mmHg of less than 220 ° C. and a vapor pressure at 20 ° C. of 0.01 mmHg or more. (C) A polyhydric alcohol having a boiling point of 220 ° C. or higher under 760 mmHg and a vapor pressure of less than 0.01 mmHg at 20 ° C. 2. The ink contains the hexylene glycol (a) and the polyhydric alcohols (b) and (c), and the total amount of the polyhydric alcohol in the ink is 10 to 30% by weight, and ( The weight ratio of the polyhydric alcohols (b) and (c) to the hexylene glycol (a) is {(b) + (c)} /
An ink jet recording method, wherein the ink of (a) = 2 to 4 is recorded on a recording medium having an ink absorbing layer composed of porous alumina particles. 3. The ink jet recording according to claim 1, wherein the ink has a pH of 7.0 or more at 20 ° C., and the recording medium has a pH of 7.0 or less at 20 ° C. Method.