JP3261734B2 - Recording liquid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording liquid, and more particularly to a recording liquid for an ink jet printer.

[0002]

2. Description of the Related Art In an ink jet recording system in which a liquid is ejected from a fine nozzle provided in a recording head by the vibration of a piezo vibrator or the action of thermal energy to perform recording, various dyes are dissolved in water or an organic solvent or It is known that a solution dissolved in these mixed solutions is used as a recording liquid (ink). However, compared to general stationery inks such as a fountain pen and a ballpoint pen, an ink jet recording liquid has many characteristics. Stricter conditions are required.

For example, ink-jet inks have appropriate physical properties such as viscosity and surface tension, high solubility stability of dissolved components, do not clog fine nozzles, stability during storage, and stability of recorded images. Crispness (high image quality), fixing speed to the recording agent (quick drying), properties such as light resistance and water resistance of the recorded image, and safety in terms of odor and fire hazard Have been.

[0004] Therefore, by using an aqueous ink using a water-soluble dye, many of the above basic requirements for the ink are satisfied.

However, in order to further improve the performance of an ink jet printer, quick drying of the ink is important for increasing the speed, but it has not yet reached a satisfactory level. That is, if the quick drying property is to be improved, the recorded image will be blurred and lack sharpness, and if the image quality is to be improved, the quick drying property is deteriorated, and there is a problem that high image quality and quick drying property cannot be compatible. .

Therefore, conventionally, the addition of a hydroxide of an alkali metal (JP-A-56-57862) and the addition of a surfactant (JP-A-56-5871, JP-A-63-13996) have been known.
4) Improvement of quick-drying properties by other additives (JP-A-63-256668) is being studied.

As a recording medium in the ink jet recording system, paper such as PPC paper and foam paper is generally used, and these papers are subjected to a process called "size" in a paper making process and used in the process. Depending on the nature of the chemical, it is roughly classified into acidic paper and neutral paper. However, JP-A-56
The ink to which the alkali metal hydroxide is added is strong alkalinity for acidic paper and dissolves the acidic sizing agent at the same time as the ink adheres and penetrates, so that quick drying can be obtained without bleeding. The effect was not obtained on paper, and there was a problem that ink drying was slow.

Further, Japanese Patent Application Laid-Open Nos.
No. 139964, to which an surfactant is added, reduces the surface tension of the ink, thereby lowering the contact angle with the recording medium, facilitating the penetration of the ink, and achieving quick drying. However, there are problems that the ejection of the ink is unstable due to low surface tension, the outline of the image is blurred because the ink spreads on the recording medium, and the storage stability is poor. As for other additives, it is difficult to obtain quick drying with high image quality, and there is a problem in storage stability.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the object thereof is to
It is an object of the present invention to provide a recording liquid having high image quality, excellent quick drying property, and good storage stability.

[0010]

Since the recording liquid used in the ink jet recording system is basically composed of a dye and a solvent, the characteristics of the recording liquid are influenced by the intrinsic properties of the dye. large. Therefore, it is considered that selecting a dye so that the recording liquid has the above-mentioned properties is a very important means for solving the above-mentioned problem, and the present inventors have studied various dyes.

As a result, it has been concluded that the following objects of the present invention can be achieved.

That is, the recording liquid of the present invention has the following general formula

[0013]

Embedded image

Wherein A, B, and M in the structural formula are: A: a substituted or unsubstituted phenyl group or a naphthyl group B: a phenyl group or a naphthyl group substituted by at least -NR ₁ R ₂ R ₁ : H , Or —OH, —NH ₂ , —C ₆ H ₅ ,> C
= O, the C ₁ -C ₁₀ containing at least one of -O- alkyl group _{R 2: -OH, -NH 2,} -C 6 H 5, C 1 ~C 10 including at least one of -O- And A represents a structure different from B. M: H, Li, Na, K, ammoniums, amines, and each represents any one selected from them. ] It is characterized by containing the disazo water-soluble dye represented by these.

This is because the disazo water-soluble dye represented by the above general formula has a penetrability to the paper itself, and the dye is contained in the recording liquid. This is due to the fact that the quick-drying property is improved due to the high penetration.

Specific examples of the compound of the above-mentioned general formula contained in the recording liquid of the present invention include disazo dyes having the following chemical structures.

[0017]

Embedded image

[0018]

Embedded image

[0019]

Embedded image

[0020]

Embedded image

[0021]

Embedded image

[0022]

Embedded image

[0023]

Embedded image

[0024]

Embedded image

[0025]

Embedded image

[0026]

Embedded image

[0027]

Embedded image

[0028]

Embedded image

[0029]

Embedded image

[0030]

Embedded image

[0031]

Embedded image

[0032]

Embedded image

[0033]

[0034]

Embedded image

[0035]

Embedded image

[0036]

Embedded image

[0037]

Embedded image

[0038]

Embedded image

[0039]

Embedded image

[0040]

Embedded image

[0041]

Embedded image

[0042]

Embedded image

[0043]

Embedded image

[0044]

Embedded image

[0045]

Embedded image

[0046]

Embedded image

[0047]

Embedded image

[0048]

Embedded image

The disazo dye contained in the recording liquid of the present invention is not limited to the disazo dye as described above, but may be any type of compound represented by the general formula of the present invention.

These disazo dyes may be used alone or as a mixture of two or more disazo dyes. The content thereof is 0.1 to 10% by weight, preferably 1 to 5% by weight. Range is good. If the amount is less than this, a sufficient density cannot be obtained in the recorded image, and the recorded image lacks sharpness. If the amount is more than this, dissolution stability of the dye, clogging of nozzles, and the like are affected.

Further, the recording liquid of the present invention includes ethanol,
At least one selected from 1-propanol and 2-propanol is contained in an amount of 0.05 to 8 wt%, preferably 2 to 6 wt%.
By including t%, more excellent quick-drying property can be obtained. If the amount is less than this, the effect of quick drying is not sufficient, and if it is more than this, the image quality is degraded.

Further, the recording liquid of the present invention includes polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, polyethylene glycol and glycerin; ethylene glycol monomethyl ether, diethylene glycol monobutyl ether And ethers of polyhydric alcohols such as dipropylene glycol monoethyl ether; nitrogen-containing compounds such as formamide, dimethylformamide, diethanolamine, triethanolamine, 1,3-dimethyl-2-imidazolidinone, 2-pyrrolidone and N-methyl-2-pyrrolidone A sulfur-containing compound such as thiodiglycol or dimethyl sulfoxide; a saccharide such as inositol or α-cyclodextrin may be contained, Correspondingly, the polymer or resin, surfactant, pH adjusting agents, fungicides, may contain additives such as ultraviolet absorbers.

[0053]

EXAMPLES The specific compositions of the recording liquids of Examples and Comparative Examples of the present invention will be described below. The percentage in the text is based on weight.

Example 1 Dye of Chemical formula 3% 3% Diethylene glycol 15% 2-propanol 3.5% Water 78.5% The above components were sufficiently mixed and dissolved, and the mixture was filtered under pressure through a membrane filter having a pore diameter of 0.8 μm. A degassing process was performed using a vacuum pump to prepare a recording liquid. Hereinafter, each recording liquid was obtained in the same manner.

Example 2 Dye of Chemical Formula 8 2.5% Glycerin 10% Ethanol 6% Water 81.5% Example 3 Dye of Chemical Formula 4 4% Glycerin 6% Thiodiglycol 8% 1-Propanol 4% Water 78% Example 4 Dye of Chemical Formula 2 2% 1,3-dimethyl-2-imidazolidinone 5% Glycerin 5% 2-propanol 3% Water 85% Example 5 Dye of Chemical Formula 3 3% Diethylene glycol 10% Triethanolamine 1% 2-propanol 2% Water 74% Example 6 Dye of Chemical formula 4% Glycerin 10% 2-Pyrrolidone 10% Ethanol 5% Water 71% Example 7 Dye of Chemical formula 2.5% Chemical formula 27 dye 2.5% Glycerin 3% 2-Pyrrolidone 3 % Ethanol 5% water 84% Example 8 Dye of Chemical Formula 3 3% 1,3-propanediol 10% N-methyl -2-pyrrolidone 3% ethanol 4% water 80% Example 9 Dye of Chemical formula 2% Diethylene glycol 10% Polyethylene glycol # 200 10% Ethanol 1% Surfynol 440 (Nissin Chemical Co., Ltd.) 1% Water 76% Example 10 Dye 3% 3% Glycerin 5% α-Cyclodextrin 3% 1-Propanol 4% Water 85% Example 11 Dye 3% 3% Diethylene glycol 20% Water 77% Example 12 Dye 3% Diethylene glycol 20% Ethanol 9% Water 68% Next, the recording liquids of Comparative Examples 1 to 3 were prepared using the following dyes.

[0056]

Embedded image

[0057]

Embedded image

[0058]

Embedded image

Comparative Example 1 Dye of Chemical Formula 3 3% Glycerin 10% Thiodiglycol 7% 1-Propanol 4% Water 76% Comparative Example 2 Dye of Chemical Formula 3 3% Diethylene glycol 10% Polyethylene glycol # 200 10% Sodium dioctyl sulfosuccinate 1 % Water 76% Comparative Example 3 Dye of Chemical Formula 2 2% Diethylene glycol 20% Potassium hydroxide 1% Water 77% Using the obtained recording liquids of Examples 1 to 12 and Comparative examples 1 to 3, the following properties were evaluated. did.

<Test 1: Storage Stability of Recording Solution> The recording solution was sealed in a glass container, stored at -30 ° C. and 70 ° C. for one month, and then compared with the initial physical property values, color tone, and insoluble matter. The presence or absence of precipitation was confirmed.

Judgment Criteria There is almost no difference between the initial physical property values and color tone, and no precipitation of insoluble components is observed. .Largecircle. The difference between the initial physical property values and color tone is large, or precipitation of insoluble components is recognized. ··· × ×

<Test 2: Image Quality of Recorded Image> The following four types of paper commonly used in offices and the like are adjusted by adjusting the voltage so that the dot weight becomes 0.12 μg by our inkjet printer HG-5130 (360 dpi). , An image was formed, and the sharpness of the recorded image was blurred, and the density was visually determined in terms of density.

Test paper • Canon Dry (Canon Sales Co., Ltd.) • Xerox 4024 (Xerox Co.) • Xerox P (Fuji Xerox Co., Ltd.) • Ricopy 6200 (Ricoh Co., Ltd.) Feel high and clear ... ◎ Slightly blurred, but has no effect on image, high density ... ○ Severe blurring or low density.

<Test 3: Fixing property of recording liquid to recording material (quick drying property)> For the following four types of paper, the voltage was adjusted using an ink jet printer HG-5130 of our company to adjust the dot weight to 0.12 μg. After printing, 20 seconds later, the printed portion was rubbed with a finger to determine the presence or absence of rubbing.

Test paper • Canon Dry (Canon Sales Co., Ltd.) • Xerox 4024 (Xerox Co.) • Xerox P (Fuji Xerox Co.) • Ricopy 6200 (Ricoh Co., Ltd.) There is no rubbing .... ◎ There is almost no rubbing in two or more types of paper .... ○ The rubbing is remarkable in two or more types of paper.

<Test 4: Clogging Characteristics> The clogging characteristics were evaluated under the following conditions by using our inkjet printer HG-5130.

Initially, after confirming that all nozzles discharge,
It is left for one month in an environment of 40 ° C. without a cap, and after the standing, it is evaluated whether or not each nozzle can print, either as it is or by performing a recovery operation (cleaning).

Judgment Criteria As it is or after cleaning, all nozzles are ejected ........ ○ No recovery after cleaning. Judgment is made based on the following criteria.

The same evaluation as Tests 2, 3, and 4 was performed using a bubble jet type ink jet printer BJ-330 (manufactured by Canon) which generates droplets by the action of thermal energy. Perform as 7.

Table 1 shows the test results.

[0071]

[Table 1]

As described above, the recording liquid of the present invention has good storage stability, and is excellent in high image quality and excellent in quick-drying property in both the piezo-vibration method and the bubble jet method. Further, it is possible to provide a recording liquid which is excellent in safety and has high versatility.

Further, the recording liquid of the present invention has good retrievability against clogging and can be used for stationery.
A product with excellent reliability can be provided.

[0074]

Conventionally, various solvents, additives and the like have been studied in order to enhance the quick-drying property of the ink. However, if the quick-drying property is to be improved, bleeding occurs in the recorded image, resulting in lack of sharpness and poor image quality. If it is attempted to increase the drying speed, the quick-drying property deteriorates, so that it is impossible to achieve both high image quality and quick-drying property. However, by using the recording liquid of the present invention, quick-drying property can be obtained with high image quality.

Further, it is excellent in storage stability, safety, and clogging characteristics, and is used for stationery, ink jet recording in which droplets are ejected from fine nozzles by vibrating by a piezoelectric vibrator or the action of thermal energy, and the like. A highly reliable recording liquid can be provided.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-56571 (JP, A) JP-A-62-86072 (JP, A) JP-A-59-75964 (JP, A) (58) Field (Int. Cl. ⁷ , DB name) C09D 11/00-11/20 C09B 35/039 C09B 35/215 CA (STN) REGISTRY (STN)

Claims (5)

(57) [Claims] 1. A recording liquid comprising a disazo water-soluble dye represented by the following general formula. [However, A, B, and M in the structural formula are: A: a substituted or unsubstituted phenyl group or a naphthyl group B: a phenyl group or a naphthyl group substituted by at least -NR ₁ R ₂ R ₁ : H, or- _{OH, -NH 2, -C 6 H} 5,> C =
O, the alkyl group R ₂ of C ₁ -C ₁₀ containing at least one of _{-O-: -OH, -NH 2, -C} 6 H 5, the C ₁ -C ₁₀ containing at least one of -O- A is an alkyl group, and A represents a different structure from B: M: H, Li, Na, K, quaternary ammonium, or organic amine, and represents any one selected from them. ] 2. The recording liquid according to claim 1, wherein the disazo water-soluble dye represented by the general formula is contained in an amount of 0.1 to 10% by weight based on the total weight of the recording liquid. 3. The recording liquid according to claim 1, wherein the disazo water-soluble dye represented by the general formula is contained in an amount of 1 to 5% by weight based on the total weight of the recording liquid. 4. At least one selected from ethanol, 1-propanol and 2-propanol is used in an amount of from 0.05 to 8%.
The recording liquid according to claim 1, wherein the recording liquid is contained in an amount of 1 wt%. 5. An amount of at least one selected from ethanol, 1-propanol and 2-propanol of 2 to 6% by weight.
The recording liquid according to claim 1, wherein the recording liquid is contained.