JPH03234773A - Ink and method for ink-jet recording using the same - Google Patents

Abstract

PURPOSE:To make it possible to form a record which does not spread even on plain paper and has excellent quality and good penetrability by mixing a water-soluble dye, a water-soluble organic solvent, water, and a specific mixed solvent. CONSTITUTION:0.1-1.5wt.% water-soluble dye is mixed with a water-soluble organic solvent (e.g. glycerin), 40-95wt.% water and 0.5-20wt.% mixed solvent obtained by mixing a compound of formula I or II (wherein R1 is alkyl or aryl unsubstituted or substituted by a group selected from the group consisting of hydroxyl, carboxyl, sulfone, amino and acetylamino; and R2-4 are each alkyl or hydroxyalkyl, any one of which may be H) with a compound of formula III (wherein R5-6 are each H, alkyl, hydroxyalkyl; and R7 is carboxyl, hydroxyl, sulfone, alkyl or H) in a weight ratio of (9:1)-(1:9).

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to inks and inkjet recording methods used in various recording instruments such as writing utensils and printers. The present invention also relates to an ink and an inkjet recording method that can perform good recording even on non-coated paper such as high-quality paper, medium-quality paper, and bond paper, so-called plain paper, which are generally used in offices.

[Conventional technology]

Conventionally, various compositions of inks for writing instruments (fountain pens, felt-tip pens, water-based ballpoint pens, etc.) and inkjet inks have been reported.

In particular, in recent years, various aspects such as composition and physical properties have been developed for ink, especially inkjet ink, for good recording even on plain paper commonly used in offices such as copy paper, report paper, notebooks, and stationery. Detailed research and development has been carried out since then.

For example, ink generally contains high-boiling organic solvents such as glycol for the purpose of preventing drying and clogging, but when recording with such ink on plain paper with a high degree of size, Since the ink does not easily penetrate into the inside of the paper and the drying properties of the recorded area are poor, there have been drying problems such as the ink getting on your hands when you touch the recorded matter and the letters rubbing and staining.

Therefore, in order to improve the permeability of the ink into the inside of the paper, Japanese Patent Application Laid-Open No. 55-29546 proposes a method of adding a large amount of surfactant to the ink. In this case, depending on the paper, there may be a lot of bleeding, and when filling military equipment, ink may drip from the pen tip, or
Additionally, when filling an inkjet head, depending on the structural conditions of the head, the ink may retreat from the orifice surface and no ejection occurs, or conversely, the entire orifice surface may become wet and the ink may not be ejected. It was observed.

Furthermore, Japanese Patent Application Laid-Open No. 54-104933 and Japanese Patent Publication No. 62
Publication No. 14189 discloses that N, N-bis(
A method of adding polyoxyethylene (or propylene)>-p-toluenesulfonic acid amide, etc. is disclosed, and although this method is effective in improving dye solubility, it does not sufficiently prevent clogging. In order to do this, it is necessary to use a fairly large amount of organic solvent such as polyhydric alcohol, which has poor drying properties on recording materials such as paper and causes stains even after a long period of time. Therefore, it is necessary to use a surfactant in combination to improve the permeability into paper, and as a result, bleeding occurs and printing quality is not sufficient.

Further, when used for inkjet recording and when ink ejection is interrupted, there is a problem that when water or the like evaporates, the above-mentioned compound retreats from the orifice surface, resulting in poor clogging prevention properties.

In addition to the above, various improvements have been attempted up to now, but to date no ink has been known that can solve all of the problems of dry printing quality and clogging.

[Problems to be Solved by the Invention] Therefore, the purpose of the present invention is to prevent clogging of the printer head even when the pen tip of a writing instrument or printer device is temporarily stopped or stopped for a long period of time, and to prevent clogging in the event that clogging occurs. To provide an ink and an inkjet recording method that can be easily recovered even in the case of a recording material, and can form a high-quality image consisting of round dots with little irregular bleeding even on a recording material. be.

[Means for solving problems]

The above objects are achieved by the present invention as described below. That is, the present invention provides an ink containing a water-soluble dye, a water-soluble organic solvent, and water according to the following formula (I) or (II).
An ink characterized by containing both a compound represented by the formula (III) and a compound represented by the general formula (III), and an inkjet recording method using the same.

＼ 4 (However, R1 represents an unsubstituted or substituted alkyl group or aryl group composed of a hydroxyl group, a carboxyl group, a sulfone group, an amino group and an acetylamino group, and R2
-R4 is an alkyl group or a hydroxyalkyl group, and one of them may be a hydrogen atom. ) (However, R5 and R6 represent a group selected from a hydrogen atom, an alkyl group, and a hydroxyalkyl group, and R7 represents a group selected from a carboxyl group, a hydroxyl group, a sulfone group, an alkyl group, and a hydrogen atom.) Effect] As a result of intensive studies on various ink compositions in order to improve anti-clogging properties, high image quality with less bleeding, etc., the present inventors found that the ink contains compounds represented by general formula (I) or (II). When a compound represented by formula (III) is used in combination with a compound represented by general formula (III), the clogging prevention property is improved compared to when each is used alone, and in the unlikely event that volatile components in the ink at the nozzle tip of the printer head are It has been found that even in the case of complete evaporation, recovery is very easy.

This phenomenon occurs due to the synergistic effect of the compound of formula (I) or (Ir) and the compound of general formula (III), which improves dye solubility, suppresses viscosity increase during ink concentration, and completely evaporates liquid components. It can be assumed that this further enhances the relaxation of aggregation and precipitation of the dye.

As a result of this effect, it is possible to reduce the number of clogging recovery operations in the printer system and the amount of ink consumed accordingly, making it possible to use the predetermined amount of ink installed in the printer more efficiently than before. Become.

-A compound of formula (I) or (II) and a compound of general formula (I)
When an ink containing the compound II) is ejected as small droplets from a nozzle of a printer head, a rapid change in the composition of the ink due to evaporation and permeation onto the recording material results in a compound of the general formula (1) or ( II) and the compound of general formula (III
) quickly increases viscosity and crystallizes, so printed dots can maintain a round shape with little irregular bleeding.

[Preferred embodiment]

Next, the present invention will be explained in more detail by citing preferred embodiments.

The compound of general formula (I) used in the ink of the present invention is:
Trimethylamine salt, triethylamine salt, triethanolamine salt of methanesulfinic acid, ethanesulfinic acid, aminomethanesulfinic acid, benzenesulfinic acid, toluenesulfinic acid, aminobenzenesulfinic acid, dicarboxybenzenesulfinic acid, hydroxybenzenesulfinic acid, respectively; Diethylamine salt, jetanolamine salt, dipropylamine salt, etc. are used.

Among these, triethylamine salt or triethanolamine salt of trienesulfinic acid is particularly preferred because of its excellent clogging prevention effect.

Moreover, the compound of the formula (II) is also the compound of the general formula (I) shown above.
) are used, and among them, triethylamine salt or triethanolamine salt of aminobenzenesulfonic acid is particularly preferred because of its excellent anti-clogging effect.

Further, particularly preferred specific examples of the compounds represented by the general formula (III) of the present invention are shown below, but the invention is not limited thereto.

Compound 1 Compound 3 Compound 4 H Compound 6 Compound of general formula (I) or (II) and general formula (III)
These compounds can be used as a mixture of one or more types, and the mixing ratio (weight) of these compounds is 9/1 to 1/
9, preferably in the range of 773 to 3/7. Further, the mixed solvent system of the present invention has a recording liquid of 0.5 to
A desired result can be obtained by containing 20% by weight, particularly preferably 1 to 10% by weight.

The dye used in the present invention is a color index (Col
Almost all of the water-soluble acidic dyes, direct dyes, basic dyes, and reactive dyes described in Or IncLex) can be used.

Also, even if it is not listed in the color index,
Any water-soluble dye can be used.

The amount of these dyes to be used is not particularly limited, but generally it is preferably in the range of 0.1 to 15% by weight, more preferably 0.1 to 10% by weight based on the total weight of the ink.
It is.

In addition to the above-mentioned components, the ink of the present invention may optionally contain a water-soluble organic solvent, a surfactant, a pH adjuster, a rust preventive agent, an antiseptic mold agent, an antioxidant, an evaporation accelerator, a chelating agent, Various additives such as water-soluble polymers may be added.

Specific water-soluble organic solvents include amides such as dimethylformamide and dimethylacetamide; ketones such as acetone; ethers such as tetrahydrofuran and dioxane; polyalkylene glycols such as polyethylene glycol and polypropylene glycol; ethylene glycol and propylene. Glycol, butylene glycol, triethylene glycol, 1.2. Alkylene glycols in which the alkylene group contains 2 to 6 carbon atoms such as 6-hexandriol, thiodiglycol, hexylene glycol, diethylene glycol; glycerin; ethylene glycol methyl (or ethyl) ether, diethylene glycol methyl (or ethyl) Lower alkyl ethers of polyhydric alcohols such as ether, triethylene glycol monomethyl (or ethyl) ether; N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, triethanolamine, sulfolane, dimethylsulf Examples include oxide.

Particularly preferred water-soluble organic solvents are alkylene glycols in which the alkylene group contains 2 to 6 carbon atoms, glycerin, and aliphatic monohydric alcohols in which the alkylene group contains 1 to 5 carbon atoms.

Further, the content of water in the ink is used in a range of 40 to 95% by weight. When the amount is less than 40% by weight, the viscosity of the ink increases, resulting in poor permeability in the vertical direction on paper.

As a result, irregular bleeding in the lateral direction was promoted, and both print drying properties and print quality tended to deteriorate.

On the other hand, if the amount exceeds 95% by weight, the amount of evaporated components will be too large and sufficient fixing properties will not be achieved.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples. Incidentally, the term "clumps" or "%" is based on weight.

Examples 1-6. Comparative Examples 1 to 4 The components shown in Table 1 were mixed, sufficiently stirred to dissolve, and filtered under pressure using a Fluoropore filter (trade name, manufactured by Sumitomo Electric Industries, Ltd.) with a pore size of 0.45 μm. Example inks were prepared.

Next, using the obtained inks of Examples 1 to 6 and Comparative Examples 1 to 4, an Ishikjet recording device was prepared, equipped with a heating element,
Using an inkjet printer BJ-130 (product name: manufactured by Canon), which utilizes a method of ejecting ink by applying thermal energy to the ink from such an element, print drying performance, clogging property evaluation, and print quality evaluation were performed. . The results are shown in Table 2.

(Evaluation method and evaluation criteria) (1) Printing drying The printing drying was evaluated at 10.20.30°40 after printing alphanumeric characters on commercially available continuous slip paper using a printer.
After 50 and 60 seconds, it was rubbed with a filter paper (Toyo Roshi Model No. 2 (trade name)) and judged based on the number of seconds until the printed area was no longer stained. (Measured at 20±5°C, 150±10%RH) ○: Within 15 seconds △: 16 to 30 seconds After printing alphanumeric characters with
H) After L/, alphanumeric characters were printed again and the number of recovery operations until the initial printing condition could be reproduced was evaluated.

◎: Printing equivalent to the initial one is possible without recovery operation ○: 1 to 5
Printing equivalent to the initial level is possible after 6 to 10 recovery operations. ×: Printing equivalent to the initial level is possible after 11 or more recovery operations. (3) Printing quality Evaluation After printing on commercially available copy paper (Xerox 4024), it was left to stand for more than 1 hour, and then bleeding at the dot level and edge sharpness were evaluated under environmental conditions of 25° C. and 60% RH.

○: There is no bleeding and the edges are sharp.

△: Some bleeding is observed, and the edges are also slightly blurred.

×: There is a lot of blurring, and the dots and edges are blurred.

Table [Effects] As explained above, according to the ink of the present invention, it does not bleed and has excellent quality even on ordinary plain paper commonly used in offices such as copy paper, report paper, notebooks, and stationery. In addition, it is possible to record with good permeability.

Further, according to the ink of the present invention, highly reliable recording can be performed without clogging of the pen tip of a writing instrument or the nozzle of an inkjet head.

Claims (6)

[Claims] (1) An ink containing a water-soluble dye, a water-soluble organic solvent, and water contains both a compound represented by the following general formula (I) or (II) and a compound represented by the general formula (III). An ink featuring ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) (However, R_1 is unsubstituted or a hydroxyl group, a carboxyl group,
represents an alkyl group or aryl group substituted with a group selected from a sulfone group, an amino group and an acetylamino group,
R_2 to R_4 are an alkyl group or a hydroxyalkyl group, and any one of them may be a hydrogen atom. ) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(III) (However, R_5 and R_6 represent groups selected from hydrogen atoms, alkyl groups and hydroxyalkyl groups, and R_7
represents a group selected from a carboxyl group, a hydroxyl group, a sulfone group, an alkyl group and a hydrogen atom. ) (2) Claim (1), wherein the mixing ratio of the compound represented by the general formula (I) or (II) and the compound represented by (III) is in the range of 9:1 to 1:9 by weight. Ink as described. (3) The total amount of the compounds is 0.5 based on the total weight of the ink.
The ink according to claim (1), in the range of -20% by weight. (4) In an inkjet recording method in which recording is performed by applying ink droplets to a recording material, the ink contains a compound represented by the following general formula (I) or (II) and a compound represented by (III). An inkjet recording method characterized by: ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) (However, R_1 is unsubstituted or a hydroxyl group, a carboxyl group,
represents an alkyl group or aryl group substituted with a group selected from a sulfone group, an amino group and an acetylamino group,
R_2 to R_4 are an alkyl group or a hydroxyalkyl group, and any one of them may be a hydrogen atom. ) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(III) (However, R_5 and R_6 represent groups selected from hydrogen atoms, alkyl groups and hydroxyalkyl groups, and R_7
represents a group selected from a carboxyl group, a hydroxyl group, a sulfone group, an alkyl group and a hydrogen atom. ) (5) The inkjet recording method according to (4), wherein the ink droplets are formed by applying thermal energy to the ink. (6) The inkjet recording method according to (4), wherein the recording material is uncoated paper.