JPS5925852A - Recording liquid - Google Patents

Abstract

PURPOSE:To provide a fuchsine-colored recording liquid of high homogeneity and light resistance, highly stable for a long period, virtually free from clogging in delivery orifice, for use in ink-jet recording, containing specific water-soluble dyes including C.I. Acid Red 37. CONSTITUTION:The objective recording liquid comprising (A) pref. 1-10wt% of a combination of water-soluble dyes consisting of (i) C.I. Acid Red 37 and (ii) at least one sort of dye selected from C.I. Acid Red 35, C.I. Acid Red 1, C.I. Acid Red 143, C.I. Acid Red 186, C.I. Acid Red 318, C.I. Direct Red 75, C.I. Direct Red 227, and C.I. Direct Red 240 and (B) water.

Description

DETAILED DESCRIPTION OF THE INVENTION The inkjet recording method produces less noise and can be used on plain paper. On the other hand, various types are being actively researched because they can perform high-speed recording without requiring special fixing. The recording liquid used in these inkjet recording methods must have physical properties such as viscosity and surface tension within appropriate ranges, and must have a fine ejection opening (orifice). : Required characteristics include not causing clogging, providing recorded images with clear color tone and sufficiently high density, and not causing changes in physical properties or precipitation of solid content during storage.

In addition to these properties, recording can be performed without any restrictions on the type of recording material such as paper, high fixing speed to the recording material, water resistance, solvent resistance (especially alcohol resistance). □Excellent in side light properties and abrasion resistance;
Properties such as providing images with excellent resolution are also required.

The recording liquid used in the inkjet recording method is basically composed of a dye as a recording agent and its solvent, so the characteristics of the recording liquid described above are largely influenced by the inherent properties of the dye. .

Therefore, selecting a dye so that the recording liquid has the above characteristics is an extremely important technique in this technical field.

In particular, the solubility of the recording liquid in the liquid medium is important, and having sufficient solubility in water and in wetting agents, which are generally organic solvents, is essential for good clogging prevention. It also serves as the basis for maintaining the dissolution stability of the recording agent.

On the other hand, when obtaining full-color recorded images using inkjet recording, recording liquids of the three primary colors of magenta, yellow, and cyan, or a recording liquid of the same primary color with black added thereto, are used, and the recording is performed by subtractive mixing of these three primary colors. The tone of the image is determined. In this case, in order to obtain a recorded image with a desired tone, it is required that the hues of these recording liquids exhibit ideal primary colors of magenta, yellow, or cyan, respectively, and have high chroma. Therefore, it is an extremely important technique to select a dye in consideration of the color tone exhibited by the recording liquid.

However, with regard to conventionally known magenta recording liquids, there are almost none that fully satisfy the above characteristics, especially solubility, color tone, light resistance, etc., and it is difficult to develop a recording liquid that satisfies these characteristics. It was strongly desired.

An object of the present invention is to provide a recording liquid that has high solubility in liquid medium components or long-term dissolution stability, and is less likely to cause clogging of an ejection orifice.

Another object of the present invention is to provide a magenta recording liquid for full-color inkjet recording that exhibits an ideal magenta color and has excellent light resistance.

The above and objects are achieved by the following invention.

That is, the present invention comprises a liquid composition containing a water-soluble dye as a recording agent, and the dyes include C and I.

(Color Index) Acid Red 37 and (a)
C, L Acid Red 3! ,C,1,Acid Red/
, C,1, Acid Red/'13, C,1, Acid Red/Totsu, C,1, Acid Red 3/g, C
, 1, Direct Red 73. C,1, Direct Red, 2.27 and C,I.

This is a recording liquid characterized in that seven or more types selected from the group consisting of Direct Red and 211θ (hereinafter abbreviated as group (a)) are used in combination.

According to the present invention, the viscosity, surface tension, etc. are within appropriate ranges,
Provides recorded images with sufficiently high density without clogging the fine orifice, and records on various materials without restricting the type of recording material without causing changes in physical properties or precipitation of solids during storage. A recording liquid can be obtained which can provide images with a high fixing speed, excellent water resistance, light resistance, abrasion resistance, and resolution.

Dyes C and I used as recording agents in the present invention.

Although Acid Red 37 has excellent properties as a recording material, such as solubility and light resistance, it exhibits a magenta color with slightly low saturation, so if only this dye is used, it cannot be used as a recording liquid for the magenta primary color. There are problems as a recording medium.

On the other hand, group (a) dyes have high chroma and are excellent in other properties such as solubility, but they have some drawbacks in terms of color tone as a magenta primary color or light resistance. Similarly, these dyes alone are not suitable as recording materials for the magenta primary color. Therefore, in the present invention,
By using C, 1, Acid Red 37 in combination with dyes from group (a), a recording material that has the ideal magenta primary color tone and is also excellent in important properties such as solubility and light fastness is created. A recording liquid containing the following properties was obtained.

The content of these color components in the recording liquid, that is, the total dye content of C, 1, acid red 37, and group (a), is determined depending on the type of liquid medium components, the characteristics required of the recording liquid, etc. However, generally the ratio is 0S to 3θ weight relative to the total amount of recording liquid, preferably θS to /B weight, more preferably 7 to
The range is 78% by weight.

Also, at this time, C,1, Acid Red 37 and (a)
The blending ratio with the seven or more dyes selected from the group (a) is determined as the optimal value for each combination of selections, since the hue exhibited by the dyes in the group differs depending on the individual dye.
Generally, it is selected within the range of /:9 to 2:/.

The recording liquid of the present invention has water as a main liquid medium component, but not only water alone but also preferably a mixture of water and various water-soluble organic solvents is used.

Examples of water-soluble organic solvents include methyl alcohol,
Alkyl alcohols with a carbon number of ~5, such as ethyl alcohol, n-propyl alcohol, isobutyl alcohol, n-butyl alcohol, 5ec-butyl alcohol, tert-butyl alcohol, and isobutyl alcohol Amides such as dimethylformamide and dimethylacetamide Types: Ketones or keto alcohols such as acetone and diacetone alcohol: Ethers such as tetrahydrofuran and dioxane: Polyalkylene glycols such as polyethylene glycol and polypropylene glycol: ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, / :, 2. B - Alkylene groups such as hexanetriol, thiodiglycol, hexylene glycol, diethylene glycol, etc.
Alkylene glycols containing 6 carbon atoms: Glycerin: Lower alkyl ethers of polyhydric alcohols such as ethylene glycol methyl ether, diethylene glycol methyl (or ethyl) ether, triethylene glycol monomethyl (or ethyl) ether, etc. .

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 preferred. Polyhydric alcohols are particularly preferred because they are highly effective as wetting agents that prevent nozzle clogging caused by evaporation of water in the recording liquid and precipitation of the recording agent.

The content of the above-mentioned water-soluble organic solvent in the recording liquid is generally in the range of 2θ to 7S, preferably 2θ to 7S, more preferably 2θ to 7S, based on the total weight of the recording liquid. be done.

The content of water at this time is determined within a wide range depending on the type of solvent component, its composition, and the desired properties of the recording liquid, but it is generally within the range of /θ to 2θ based on the total weight of the recording liquid. It is preferably in the range of /θ to 7θ, more preferably in the range of 2θ to 7θ.

A solubilizer can also be added to the recording liquid of the present invention. Typical solubilizing agents are nitrogen-containing heterocyclic ketones, and their intended action is to dramatically improve the solubility of recording agents in liquid media. For example, N-methyl-2
-pyrrolidone, X3-dimethyl-2-imidazolidinone, etc. are preferably used.

The recording liquid of the present invention prepared from such components has excellent recording properties (signal response, stability of droplet formation, ejection stability, long-term continuous recording, and long-term recording cessation). Discharge Stability) The storage stability, fixing properties to recording materials, and the light resistance, weather resistance, and water resistance of recorded images are all well-balanced and excellent. In order to further improve such properties, various conventionally known additives may be added.

Examples: Viscosity modifiers such as EVA, polyhinyl alcohol, celluloses, water-soluble resins, etc.: Various cationic, anionic or nonionic surfactants, surface tension modifiers such as jetanolamine, triethanolamine, etc.: PH by buffer solution Adjusting agents and the like can be mentioned.

Further, in order to prepare a recording liquid used in an inkjet recording method of the type in which the recording liquid is charged, a resistivity adjuster such as inorganic salts such as lithium chloride, ammonium chloride, and sodium chloride is added.

Note that when applied to an inkjet system in which recording liquid is ejected by the action of thermal energy, thermal physical property values (eg, specific heat, coefficient of thermal expansion, thermal conductivity, etc.) may be adjusted.

The recording liquid of the present invention has particularly excellent properties as a recording liquid for inkjet recording, but it can also be used for recording with conventional writing instruments such as fountain pens and felt pens that record on recording materials such as paper. It can also be used as a liquid.

The invention will be explained in more detail in the following examples.

Example/ A magenta primary color recording liquid for inkjet recording was prepared according to the following formulation.

C,1, Acid Hood 37 70 wt%C,1,
Acid red, 15 /θ 〃Diethylene glycol 3ρθ 〃N-methyl-2-pyrrolidone /jθ Weight ratio ion exchange water
Remaining Amount The above-mentioned ingredients were stirred in a container to be uniformly mixed and dissolved, filtered through a Fluorobore filter with a pore size of 0llsμ, and further deaerated to obtain a recording liquid.

This recording liquid is ejected by an on-demand inkjet recording head using a piezoelectric vibrator (discharge orifice diameter jθμ, piezoelectric vibrator drive voltage Oθ■, frequency' (KH
The ejection stability was investigated using a recording apparatus having the following. As a result, at room temperature (,2/℃), 5℃, and θ
Good ejection stability was maintained both in continuous ejection for each time period and intermittently ejected for 2 times in an atmosphere of 3.degree. C. and 2.degree. C. (humidity 3.theta.).

On the other hand, we investigated the long-term storage stability of the recording liquid at 0°C, 3θ°C,
The test was carried out at θ°C for ρ years, but no problems such as recording agent precipitation or discoloration occurred.

The color tone of the printed matter was a clear and bright ideal magenta color, and even after a 59-hour irradiation test using a xenon fade meter, the printed matter was fully legible and had good light resistance.

Example! A magenta primary color recording liquid based on the following formulation was prepared in the same manner as in Example.

C, 1, Acid Red 37 75% by weight C0
■、Acid Dred / /S〃Diethylene glycol /Fθ〃z3-dimethyl-2
-Imidazolidinone /j;, □ttPolypolylene glycol (3θθ)/Sθ 〃Ion exchange water
Remaining Amount On the other hand, a yellow primary color recording liquid, a cyan primary color recording liquid, and a black recording liquid were prepared in the same manner as above.

However, instead of C,1, Acid Red 37 and C,1, Acid Red/, C,I is used in the yellow primary color recording liquid.

Acid yellow 33 gold, cyan primary color recording liquid C,1
, direct blue, black recording liquid C, 1
, Direct Black/9 were added in an amount of 3 parts by weight each.

On-demand type multi-head (discharge orifice diameter 3.5μ, heating resistor resistance value/jθΩ, drive voltage 3θV, frequency, 2KH
Regarding zero ejection stability, a color printing test was conducted by supplying the inkjet ink to a recording apparatus having the following properties: Stable ejection was maintained in all cases under the same conditions as in Example. In addition, the obtained image is also a full color image in which a predetermined color tone is expressed,
It was evaluated that each recording liquid was excellent as a primary color liquid for subtractive color mixing.

Furthermore, the print was still legible even after the same light fastness test as in Example.

Examples 3 to 2 The magenta primary color was prepared in the same manner as in Example/, except that the dyes shown in Table -/ and their amounts were used instead of C, R, Acid Red 37 and C,1, Acid Red 3S. A recording liquid was prepared. These recording liquids were evaluated for ejection stability, long-term storage stability, color tone of printed matter, and light resistance in the same manner as in Examples, and all were good, making them excellent as recording liquids for magenta primary color. Table-/Note) A-R is C, 1, Acid Red, D, Ri
dC,I.

Featuring direct red Patent applicant: Canon Co., Ltd.

Claims (1)

[Claims] / Composed of a liquid composition containing a water-soluble dye as a recording agent, the dye being C,1, Acid Red 37, and ←)C
,1,Acid Red 3.5,C,1,Acid Red/,C,T,Acid Red/'13,C,1,Acid Red Fug Otsu,C,1,Acid Red 37g%C,
1. A recording liquid characterized in that seven or more selected from the group consisting of Direct Red 7.5, C, I Direct Red Lυ and C, 1, Direct Red, 241θ are used in combination.