JPH0653866B2 - Inkjet recording method - Google Patents

Description

TECHNICAL FIELD The present invention relates to an ink jet recording liquid method for recording on a recording material such as paper, film, glass, metal, cotton, etc., particularly on paper or cloth using an ink. .

[Conventional technology]

As a recording liquid that can be used in a writing instrument, an ink jet printer, etc., various compositions having various compositions have been conventionally proposed.

As the performance required for a recording liquid used for a writing instrument, an inkjet printer, etc., (1) no bleeding occurs in the writing or the printed matter, (2) the writing or the printed matter is quick-drying, (3) Even after being left for a long period of time, the pen tip or the print head does not easily dry and the nozzles are not clogged, (4) storage safety is good, (5) high safety, and the like.

Among these required performances, the one that is technically difficult is
(1), (2) and (3). This is because, in general, the quick-drying property of the printed matter and the drying properties of the pen tip and the printer head are in an inverse relationship.

For example, a method in which a surfactant is added to the ink is usually considered as a means for improving the dryness of a written or printed matter.

In this case, when writing or printing on paper or cloth that is generally used in office paper such as notebooks, report paper, copy paper, and stationery, the ink spreads along the fibers of the paper or cloth and causes bleeding. .

In addition, a method of adding a water-soluble polymer to the ink is also often used for the purpose of improving the drying property of written materials and printed materials. In this case, the bleeding can be suppressed, but the pen tip and the tip of the printer head are easily dried, which is a serious obstacle in writing or printing.

Therefore, conventionally, for example, when recording with a general inkjet printer, a paper dedicated to the inkjet printer,
In other words, by using a special paper that has good ink absorbency and is less likely to cause irregular bleeding, in combination with the ink designed to be hard to dry in the printer head, the above (1) to (3) can be performed at the same time. We are constructing a system that satisfies us.

In such a printer system, it is not possible to print satisfactorily on commonly used office paper such as notebooks, report papers, copy papers, and stationery, especially fine ruled lines and fine characters, JIS second standard. Often, complicated kanji such as those defined as are unclear and difficult to see.

In addition, the paper as described above is generally sized in the papermaking process so that bleeding does not easily occur with writing instruments that use water-based ink such as fountain pens, so when writing, the hands are ink-free. When it gets dirty or when it is printed with an inkjet printer, the ink does not easily penetrate into the paper, so the printed part is poorly dry and it takes a long time to dry. There was a problem that the ink could get on the hand when touched.

Therefore, various improvements have been attempted up to now, but an ink capable of solving all the problems such as the above-mentioned bleeding and writing, the drying property of the printed matter, the drying property of the pen tip and the print head, etc. has been obtained so far. The current situation is that there are none.

[Problems to be solved by the invention]

Therefore, an object of the present invention is to solve the above-mentioned problems in inkjet recording.

That is, it is an object of the present invention to provide an ink jet recording method that improves the bleeding and drying properties of printed matter, does not cause clogging in the printer head, and has excellent ink storage stability and safety.

[Means for solving problems]

 The above object is achieved by the present invention described below.

That is, the present invention is an inkjet recording method for recording by ejecting ink droplets from an orifice, wherein the ink is composed mainly of a recording medium and a liquid medium that dissolves or disperses the recording medium, and alkylene of sorbitol, sorbitan, and sorbite. An ink jet recording method, which is a water-based ink containing an oxide adduct and / or an alkyl, alkenyl or aryl ether compound of the adduct. However, compounds having an ester structure in the molecule are excluded.

<Operation> The ink used in the present invention contains at least water, a recording agent, and an alkylene oxide adduct of sorbitol, sorbitan, and sorbite and / or an alkyl, alkenyl, or aryl ether compound of the adduct.

The alkylene oxide adduct of sorbitol, sorbitan, and sorbite referred to in the present invention is sorbitol, sorbitan, and sorbite in which an alkylene oxide is added to a hydroxyl group.

The alkyl, alkenyl or aryl etherified product of the adduct is a compound in which the hydroxyl group contained in the adduct is alkylated, alkenyl or aryl etherified.

The sorbitol according to the present invention is a sugar alcohol represented by the chemical formula of C ₆ H ₁₄ O ₆ , and sorbitan and sorbite are compounds that can be synthesized by intramolecular dehydration of sorbitol.

Examples of alkylene oxides added to sorbitol and its derivatives include ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran.

The number of moles of alkylene oxide added to one molecule of sorbitol and its derivative is preferably 1 to 50, and more preferably 2 to 25.

The alkylene oxides to be added may be the same or different and may be in the form of a block copolymer or a random copolymer.

Examples of the alkyl group, alkenyl group or aryl group which etherifies the alkylene oxide adduct of sorbitol and its derivatives include C _{1 to} C ₂₀ alkyl groups, alkenyl groups and phenyl groups, substituted phenyl groups, naphthyl groups and substituted naphthyl groups. And other aryl groups.

The position of etherification may be the hydroxyl group of sorbitol and its derivative or the hydroxyl group at the alkylene oxide chain end.

The alkylene oxide adduct of sorbitol and its derivative and the etherified product thereof according to the present invention are characterized in that they do not contain an ester structure in the molecule, and in this respect, a sorbitan-based compound such as polyoxyethylene sorbitan monolaurate known in the related art is used. It is completely different from nonionic surfactants.

The alkylene oxide adduct of sorbitol and its derivative and the etherified product thereof according to the present invention have various conditions such as the type of alkylene oxide, alkyl group, alkenyl group or aryl group used, the number of moles of alkylene oxide added, and the degree of etherification. Thereby, the physical properties such as the viscosity and the solubility in water are made different.

In general, ethylene oxide adducts are unlikely to cause bleeding, and adducts such as propylene oxide and butylene oxide, and alkyl, alkenyl, and aryl ether compounds are excellent in drying property, but tend to be slightly soluble in water. It is preferable to use one kind or a mixture of two or more kinds as necessary.

The amount of these compounds added to the ink may be from a small amount such as an additive to a large amount such as a solvent, depending on the characteristics of the compound, and the addition amount is not particularly limited.

As the recording material used in the present invention, either a dye or a pigment can be used, and a color index (Color I
Almost all of the water-soluble acid dyes, direct dyes, basic dyes, and reactive dyes described in (ndex) can be used, and also pigments can be used in a state of being dispersed in an aqueous liquid medium. Is.

In addition, even those not listed in the color index can be used as long as they are water-soluble dyes, and also for pigments, those not listed in the color index,
Any substance can be used as long as it can be dispersed in an aqueous liquid solvent.

The amount of these recording agents used is not particularly limited, but is generally 0.1 to 15 relative to the total weight of the ink.
A weight% range is preferred.

In addition to the above components of the ink used in the present invention, if necessary, a water-soluble organic solvent, a surfactant, a pH adjusting agent, an anticorrosive agent, an antiseptic / antifungal agent, an antioxidant, an evaporation accelerator, Various additives such as chelating agents and water-soluble polymers may be added.

Specifically, as the water-soluble organic solvent, ethylene glycol, diethylene glycol, triethylene glycol,
Polyethylene glycol, propylene glycol, polypropylene glycol, ethylene oxide-propylene oxide copolymer, trimethylene glycol, 1,
Polyhydric alcohols such as 3-butanediol, 1,4-butanediol, hexylene glycol and glycerin, and their derivatives N- such as alkyl ethers and aryl ethers
Methyl-2-pyrrolidone, 1,3-dimethylimidazolidinone, sulfolane, r-butyrolactone, tetrahydrofurfuryl alcohol, diacetone alcohol, triethanolamine, hydroxyethylmorpholine and the like can be mentioned. Further, as a surfactant, various anionic compounds,
Cationic, amphoteric or nonionic surfactants can be used, but from the viewpoint of ink storage stability, surfactants that do not contain hydrolyzable structures such as carboxylic acid ester structures and amide structures in the molecule are used. It is desirable to do.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. In the following, all "parts" mean "parts by weight". EO is ethylene oxide and PO is propylene oxide.

Example 1 After sufficiently stirring with the above composition, a fluoropore filter with a pore size of 1 μ (trade name, manufactured by Sumitomo Electric Industries, Ltd.)
And filtered to obtain the ink used in the present invention.

Example 2 An ink used in the present invention was prepared in the same manner as in Example 1 with the above composition.

Example 3 An ink used in the present invention was prepared in the same manner as in Example 1 with the above composition.

Example 4 An ink used in the present invention was prepared in the same manner as in Example 1 with the above composition.

Example 5 An ink recording liquid used in the present invention was prepared in the same manner as in Example 1 with the above composition.

Example 6 An ink used in the present invention was prepared in the same manner as in Example 1 with the above composition.

Example 7 A composition for use in the present invention having the above composition was prepared in the same manner as in Example 1.

Example 8 An ink used in the present invention was prepared in the same manner as in Example 1 with the above composition.

Comparative Example 1 The EO adduct of sorbitol of Example 1 was replaced with polyethylene glycol 600 (average molecular weight 600) to give the following composition.

Comparative Example 2 The lauryl ether of the sorbitol PO adduct of Example 4 was replaced with Rheodor TW-L120 (trademark of polyoxyethylene (20) sorbitan monouralate, manufactured by Kao Soap Co., Ltd.), and the following composition was obtained. did.

Table 1 shows the physical properties of the inks of Examples 1 to 8 and Comparative Examples 1 and 2, and the print evaluation results and the storage stability evaluation results when printed with an inkjet printer.

In Table 1, “B” of the printer is an ink jet printer that uses a heating element as a protruding energy source of ink (Olyphis size 50 × 40 μ, 24 nozzles).
, P indicates an inkjet printer (orifice size 65 μφ, 4 nozzles) that uses a piezo-piezoelectric element as an ink ejection energy source, and indicates the type of printer used to evaluate the occurrence rate of bleeding and the dryness of printing. Show.

Regarding the occurrence rate of bleeding, after printing 300 dots on a continuous continuous slip paper with a printer so that it does not continue,
After leaving it for one hour or more, the number of dots causing bleeding was counted with a microscope and evaluated based on%. (22 ± 5 ℃, 60 ± 10%
(Printed by RH) ○: 15% or less △: 16 to 40% ×: 41% or more Regarding the printing dryness, after printing alphanumeric characters on a commercially available continuous slip paper with a printer, 10, 20, 30, 40 , 5
After 0 and 60 seconds, the print part was rubbed with a filter paper (No. 2, trade name, manufactured by Toyo Roshi Kaisha, Ltd.), and the judgment was made based on the number of seconds until the print was not stained. (22 ± 5 ℃, 60 ± 10%
(Printed and measured by RH) ○: within 20 seconds △: 20 to 40 seconds ×: 41 seconds or more For storage stability, 100 cc of each ink was placed in a heat-resistant glass bottle and stored in a constant temperature bath at 60 ° C for 3 months. After saving, 100 sheets of continuous slip paper were printed with a printer and evaluated.

○: No abnormality ×: Abnormality (clogging, non-ejection, discoloration, etc.) [Effect] The ink used in the present invention is particularly suitable as an ink for an ink jet printer because it has less bleeding of printed matter and is excellent in drying property.

The alkylene oxide adducts of sorbitol, sorbitan and sorbite and / or the alkyl, alkenyl or aryl etherified products of the adducts used in the present invention do not contain an ester structure in the molecule and are conventionally known. Like a sorbitan nonionic surfactant such as polyoxyethylene sorbitan monolaurate, it is stable without being hydrolyzed in an aqueous liquid medium, and the ink itself has good storage stability.

Furthermore, the inks of Examples 1 to 8 were used in an inkjet printer, and printing was attempted on an OHP film for inkjet printers and a broad cloth made of 100% cotton. In all cases, bleeding was small and good printing was possible. .

Claims (1)

[Claims] 1. An inkjet recording method for recording by ejecting ink droplets from an orifice, wherein the ink is composed mainly of a recording material and a liquid medium for dissolving or dispersing the recording material, and an alkylene of sorbitol, sorbitan or sorbite. An ink jet recording method, which is an aqueous ink containing an oxide adduct and / or an alkyl, alkenyl or aryl ether compound of the adduct (excluding compounds having an ester structure in the molecule).