JPH061937A - Recording liquid - Google Patents

Abstract

PURPOSE:To provide a recording liquid containing a specific water-soluble dye, quickly dryable while keeping high image quality, having excellent storage stability and useful as a recording liquid for writing utensils or ink-jet printer. CONSTITUTION:The objective recording liquid contains (A) 0.1-10wt.% (preferably 1-5wt.%) of a water-soluble dye of formula I (R1 is H or 1-10C substituent containing one or more groups such as OH and NH2; R2 is 1-10C substituent containing one or more OH, NH2 or C6H5 groups; M is H, Li, Na, ammonium, etc.) (e.g. the compound of formula II, formula III, etc.) and (B) 0.05-8wt.% (preferably 2-6wt.%) of ethanol, 1-propanol or 2-propanol.

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 liquid is ejected from fine nozzles provided in a recording head due to vibration of a piezoelectric vibrator or the action of heat energy, various dyes are mixed with water or an organic solvent, or It is known that what is dissolved in these mixed solutions is used as the recording liquid (ink), but the inkjet recording liquid has many characteristics compared to general stationery inks such as fountain pens and ballpoint pens. More stringent conditions are required.

For example, physical properties such as viscosity and surface tension are suitable for ink jet inks, dissolution stability of dissolved components is high, fine nozzles are not clogged, stability during storage, recorded image. Sharpness (high image quality), fixing speed to recording material (quick drying), light resistance of recorded images, water resistance, etc., and safety in terms of odor and fire risk Has been done.

Therefore, by using a water-based ink containing 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 speeding up, but it has not yet reached a satisfactory level. That is, when trying to increase the quick-drying property, a bleed occurs in a recorded image, resulting in lack of clarity, and when trying to increase the image quality, the quick-drying property deteriorates, and there is a problem that both high image quality and quick-drying property cannot be achieved at the same time. .

Therefore, conventionally, the addition of an alkali metal hydroxide (JP-A-56-57862) and the addition of a surfactant (JP-A-56-5871, JP-A-63-13996).
4) and other additives (Japanese Patent Laid-Open No. 63-256668) are being studied to improve the quick-drying property.

Papers such as PPC papers and foam papers are generally used as the recording medium in the ink jet recording system, and these papers are subjected to a process called "size" in the paper making process and used at the time of the process. It is roughly classified into acidic paper and neutral paper depending on the nature of the chemicals. However, JP-A-56
The ink with alkaline metal hydroxide described in -57862 dissolves the acidic sizing agent at the same time as the ink adheres to the acidic paper due to its strong alkalinity and penetrates, so quick drying without bleeding can be obtained. The effect cannot be obtained on paper, and there is a problem that the ink dries slowly.

Further, Japanese Patent Laid-Open Nos. 56-5871 and 63
In the ink containing the surfactant described in 139964, the surface tension of the ink is lowered, so that the contact angle with the recording medium is lowered to facilitate the penetration of the ink and obtain the quick drying property. However, there are problems that the discharge of ink is unstable due to the low surface tension, the outline of the image is blurred due to spreading on the recording medium, and the storage stability is poor. With other additives, it is difficult to obtain high image quality and quick drying property, and there is a problem in storage stability.

[0009]

DISCLOSURE OF THE INVENTION The present invention is to solve the above-mentioned problems, and the purpose thereof is to:
The purpose of the present invention is 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 its solvent, the characteristics of the recording liquid depend on the properties peculiar to the dye. large. Therefore, it is considered that selecting a dye so that the recording liquid has the above characteristics is an extremely important means for solving the above problems, and the present inventors have studied various dyes.

As a result, it was concluded that the present invention can achieve the object.

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

[0013]

[Chemical 2]

[Wherein R ₁ , R ₂ and M in the structural formula are R ₁ : H, or —OH, —NH ₂ , —C ₆ H ₅ ,> C
= O, the substituents of C ₁ -C ₁₀ containing at least one of _{-O- R 2: -OH, -NH 2} , -C 6 H 5, C 1 ~C 10 including at least one of -O- Substituent M: H, Li, Na, K, ammoniums, amines, each of which is any one selected from them. ] It is characterized by containing a water-soluble dye.

Since the water-soluble dye represented by the above general formula has a penetrability to paper, the inclusion of this dye in the recording liquid causes a rapid penetration when the recording liquid adheres to the paper. It seems that the quick-drying property is improved due to the above.

Specific examples of the compound of the above general formula contained in the recording liquid of the present invention include dyes having the chemical structures shown below.

[0017]

[Chemical 3]

[0018]

[Chemical 4]

[0019]

[Chemical 5]

[0020]

[Chemical 6]

[0021]

[Chemical 7]

[0022]

[Chemical 8]

[0023]

[Chemical 9]

[0024]

[Chemical 10]

[0025]

[Chemical 11]

[0026]

[Chemical 12]

[0027]

[Chemical 13]

[0028]

[Chemical 14]

[0029]

[Chemical 15]

[0030]

[Chemical 16]

[0031]

[Chemical 17]

[0032]

[Chemical 18]

[0033]

[Chemical 19]

[0034]

[Chemical 20]

[0035]

[Chemical 21]

[0036]

[Chemical formula 22]

[0037]

[Chemical formula 23]

[0038]

[Chemical formula 24]

[0039]

[Chemical 25]

[0040]

[Chemical formula 26]

[0041]

[Chemical 27]

[0042]

[Chemical 28]

[0043]

[Chemical 29]

[0044]

[Chemical 30]

[0045]

[Chemical 31]

[0046]

[Chemical 32]

The dye contained in the recording liquid of the present invention is
The dye is not limited to the above dyes, and may be of any type as long as it is a compound represented by the general formula of the present invention.

These dyes may be used alone or as a mixture of two or more kinds, and the content thereof is in the range of 0.1 to 10 wt%, preferably 1 to 5 wt%. Is good. If it is less than this, sufficient density cannot be obtained in the recorded image and the recorded image lacks in clarity, and if it is more than this, dissolution stability of the dye, nozzle clogging, etc. are affected.

The recording liquid of the present invention contains ethanol,
0.05-8 wt%, preferably 2-6 w of at least one selected from 1-propanol and 2-propanol
By including t%, further excellent quick drying property can be obtained. If it is less than this range, the effect of quick drying is not sufficient, and if it is more than this range, the image quality is deteriorated.

Further, the recording liquid of the present invention contains 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. , 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, N-methyl-2-pyrrolidone A sulfur-containing compound such as thiodiglycol or dimethylsulfoxide may be contained, and if necessary, a polymer or resin, a surfactant, a pH adjusting agent Fungicides, it may contain additives such as ultraviolet absorbers.

[0051]

EXAMPLES Hereinafter, specific compositions of the recording liquids of Examples and Comparative Examples of the present invention will be described. In the text,% is based on weight.

Example 1 Dye of formula 6 3% Glycerin 8% Ethanol 6% Water 83% The above components were thoroughly mixed and dissolved, and after pressure filtration with a membrane filter having a pore size of 0.8 μ, a vacuum pump was used. It was degassed and prepared as a recording liquid. Hereinafter, each recording liquid was obtained by the same method.

Example 2 Dye of Formula 9 3% Diethylene glycol 15% 2-Propanol 3.5% Water 78.5% Example 3 Dye of Formula 3 3% Glycerin 6% Thiodiglycol 10% 1-Propanol 4% Water 77% Example 4 Dye of Formula 18 4% 1,3-Dimethyl-2-imidazolidinone 3% Glycerin 5% 1-Propanol 8% Water 80% Example 5 Dye of Formula 13 3% Glycerin 3% 2-Pyrrolidone 3% Ethanol 5% Water 86% Example 6 Dye of Formula 14 3% Diethylene glycol 10% Triethanolamine 1% 2-Propanol 2% Water 74% Example 7 Dye of Formula 3 2.5% Dye of Formula 24 2.5% Glycerin 10% 2-Pyrrolidone 5% Ethanol 5% Water 75% Example 8 Dye of Chemical Formula 2 2% Dye of Chemical Formula 2 2% 1, -Propanediol 10% N-methyl-2-pyrrolidone 1% Ethanol 2% Water 83% Example 9 Dye of 20 2% Diethylene glycol 10% Polyethylene glycol # 200 10% Ethanol 1% Surfynol 465 (Nissin Chemical Co., Ltd.) 1% Water 76% Example 10 Compound 5 dye 5% Glycerin 5% α-Cyclodextrin 3% 1-Propanol 7% Water 80% Example 11 Compound 22 dye 3% Diethylene glycol 20% Water 77% Example 12 Compound 32 Dye 3% 1,5-pentanediol 5% glycerin 10% ethanol 9% water 73% The following dyes were used to prepare recording liquids of Comparative Examples 1 to 3.

[0054]

[Chemical 33]

[0055]

[Chemical 34]

Comparative Example 1 Dye of Chemical Formula 3 3% Diethylene glycol 15% 2-Propanol 3.5% Water 78.5% Comparative Example 2 Dye of Chemical Formula 33 3% Diethylene glycol 10% Polyethylene glycol # 200 10% Sodium dioctyl sulfosuccinate 1% Water 76% Dye of Comparative Example 3 34 3% Diethylene glycol 20% Potassium hydroxide 1% Water 76% Using the obtained recording liquids of Examples 1-12 and Comparative Examples 1-3, the following properties were evaluated. .

<Test 1: Storage stability of recording liquid> After the recording liquid was sealed in a glass container and stored at -30 ° C and 70 ° C for 1 month, the initial physical properties, comparison with color tone and insoluble matter were recorded. The presence or absence of precipitation was confirmed.

Judgment Criteria Almost no difference from the initial physical properties or color tone, no precipitation of insoluble matter is observed .... ○ Large difference from initial physical properties or color tone, or insoluble matter <Test 2: Image quality of recorded image> The voltage was adjusted so that the dot weight would be 0.12 μg with our inkjet printer HG-5130 (360 dpi). An image was formed on the following four types of paper that are generally used for the following purposes, and the sharpness of the recorded image was visually judged in terms of image bleeding and density.

Test Paper ・ Canon Dry (Canon Sales Co., Ltd.) ・ Xerox 4024 (Xerox Co.) ・ Xerox P (Fuji Xerox Co., Ltd.) ・ Ricopy 6200 (Ricoh Co., Ltd.) Feels high and clear ... ◎ Slight bleeding does not affect the image, and the density is high ... ○ Severe bleeding or low density ... × <Test 3: Fixing the recording liquid on the recording material (Fast-drying)> Our inkjet printer HG for the following four types of paper
With -5130, the voltage was adjusted so that the dot weight was 0.12 μg, and printing was performed. After 20 seconds, the printed portion was rubbed with a finger to determine the presence or absence of rubbing.

Test Papers-Canon Dry (Canon Sales Co., Ltd.)-Xerox 4024 (Xerox Co.)-Xerox P (Fuji Xerox Co., Ltd.)-Ricopy 6200 (Ricoh Co., Ltd.) Judgment Criteria No rubbing: ◎ Almost no rubbing on 2 or more types of paper. ○ Marked rubbing on 2 or more types of paper: × <Test 4: Clogging characteristics> Our inkjet printer HG The clogging property was evaluated using -5130 under the following conditions.

Initially, after confirming that all nozzles discharge,
Whether or not printing is possible is evaluated for each nozzle by leaving it for 1 month slowly in an environment of 40 ° C. without a cap, and then leaving it or performing a recovery operation (cleaning).

Judgment criteria As it is or after cleaning, all nozzles are ejected .... ○ Does not recover even after cleaning ... , Bubble jet type inkjet printer BJ-330 that generates droplets by the action of thermal energy
(Manufactured by Canon Inc.) is used to perform the same evaluations as Tests 2, 3 and 4 as Tests 5, 6 and 7.

Table 1 shows the above test results.

[0064]

[Table 1]

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

Further, the recording liquid of the present invention has a good ability to recover from clogging and can be used for stationery,
We can provide highly reliable products.

[0067]

Various solvents, additives, etc. have hitherto been studied in order to enhance the quick-drying property of ink. However, when attempting to enhance the quick-drying property, bleeding occurs in a recorded image, resulting in lack of sharpness, resulting in poor image quality. Since high-quality images and high-speed drying properties cannot be achieved at the same time because the high-quality images are deteriorated when they are attempted to be increased, by using the recording liquid of the present invention, high-quality images can be obtained with high-speed properties.

Further, it has excellent storage stability, safety, and clogging characteristics, and is used for stationery and for ink jet recording in which droplets are ejected from a fine nozzle due to vibration of a piezo oscillator or the action of thermal energy. It is possible to provide a recording liquid having excellent reliability as the recording liquid.

Claims (3)

[Claims] 1. A recording liquid containing a water-soluble dye represented by the following general formula. [Chemical 1] [However, R ₁ , R ₂ , and M in the structural formula are R ₁ : H, or —OH, —NH ₂ , —C ₆ H ₅ ,> C.
= O, the substituents of C ₁ -C ₁₀ containing at least one of _{-O- R 2: -OH, -NH 2} , -C 6 H 5, C 1 ~C 10 including at least one of -O- Substituent M: H, Li, Na, K, ammoniums, amines, each of which is any one selected from them. ] 2. The water-soluble dye represented by the general formula is 0.1 to 10 wt%, preferably 1 to 10% by weight based on the total weight of the recording liquid.
The recording liquid according to claim 1, wherein the recording liquid is contained in an amount of ˜5 wt%. 3. At least one selected from ethanol, 1-propanol and 2-propanol is used in an amount of 0.05-8.
The recording liquid according to claim 1, wherein the recording liquid is contained in an amount of wt%, preferably 2 to 6 wt%.