JPH0621248B2 - Inkjet recording ink - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is suitable for recording materials such as paper, film, glass, metal, cloth, and the like, and particularly suitable for an ink jet printer for recording with ink on paper, cloth. Regarding recording liquid.

[Conventional technology]

As a recording liquid that can be used in ink jet printers,
Conventionally, various compositions have been proposed.

The performance required for a recording liquid used in an ink jet printer or the like includes (1) no bleeding on the printed matter, (2) the printed matter is quick-drying, and (3) when left for a long time. However, the planter head is difficult to dry, and the nozzle is not clogged, (4) good storage safety, (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 resistance at the printer head are in a mutually contradictory relationship.

For example, a method in which a surfactant is added to the ink in order to improve the drying property of the printed matter is usually considered.

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. .

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

Therefore, conventionally, for example, when recording with a general ink jet printer, it is difficult to dry the dedicated paper for the ink jet printer, that is, the special paper that has good ink absorbability and is less likely to cause irregular bleeding in the printer head section. By using it in combination with the ink designed in (1), a system that satisfies the above (1) to (3) at the same time is configured.

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 subjected to size processing in the paper manufacturing process so that bleeding is unlikely to occur with a writing instrument using a water-based ink such as a fountain pen, so when printed with an ink jet printer, Since the ink does not easily penetrate inside the paper, and the printed part is poorly dry and it takes a long time to dry, the printed matter may be rubbed and dirty with the printer cover, and the ink may get on your hands when you touch it. there were.

Therefore, various improvements have been attempted so far, but an ink that solves all the problems such as the above-mentioned bleeding, the drying property of the printed matter, the drying resistance of the print head, etc. has not been obtained so far. The current situation.

[Problems to be solved by the invention]

Therefore, an object of the present invention is to solve the above-mentioned problems of conventional inks that can be used in ink jet printers and the like.

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

[Means for solving problems]

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

That is, the present invention provides an inkjet recording ink mainly composed of a recording agent and a liquid medium in which the recording agent is dissolved or dispersed, wherein an alkylene oxide adduct of pentose or a sugar alcohol thereof and / or an alkyl or alkenyl of the adduct. Alternatively, an ink for inkjet recording is characterized by containing an aryl ether compound.

<Function> The ink of the present invention contains at least water, a recording agent and an alkylene oxide adduct of pentose or a sugar alcohol thereof and / or an alkyl, alkenyl or aryl ether compound of the adduct.

In the present invention, the alkylene oxide adduct of pentose or its sugar alcohol is an alkylene oxide added to the hydroxyl group of pentose or its sugar alcohol.

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

Specific examples of the pentose or the sugar alcohol thereof according to the present invention include arabilis, xylulose, xylose, lyxose, ribulose, ribose, arabitol, ribitol and the like.

Examples of the alkylene oxide added to pentose or its sugar alcohol include ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran.

The number of moles of alkylene oxide added to one molecule of pentose or its sugar alcohol 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 block copolymer or random copolymer.

The alkyl group, alkenyl group or aryl group for etherifying the alkylene oxide adduct of pentose or its sugar alcohol is a C ₁ -C ₂₀ alkyl group,
Examples of the aryl group include an alkenyl group, a phenyl group, a substituted phenyl group, a naphthyl group, and a substituted naphthyl group.

The position of etherification may be the hydroxyl group of pentose or its sugar alcohol, or the hydroxyl group at the alkylene oxide chain end.

The alkylene oxide adduct of pentose or sugar alcohol thereof 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, conventionally known sorbitan ester-based and sucrose ester-based surfactants are used. It is completely different from the agent.

The alkylene oxide adduct of pentose or its sugar alcohol and its etherified product according to the present invention are pentose or its sugar alcohol, alkylene oxide, alkyl group, alkenyl group or aryl group,
The physical properties such as the viscosity and the solubility in water are different depending on various conditions such as the number of moles of alkylene oxide added and the degree of etherification.

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 amount to be added is not particularly limited. .

As the recording agent 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.

Further, even if not described in the color index, any water-soluble dye can be used, and as for the pigment,
Even if it is not described in the color index, it can be used if 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 1 relative to the total weight of the recording liquid.
A range of 5% by weight is preferred.

The recording liquid of the present invention contains water, a recording agent, pentose or an alkylene oxide adduct of sugar alcohol thereof and / or an alkyl, alkenyl or aryl ether compound of the adduct as a main component. , Various additives such as water-soluble organic solvents, surfactants, pH adjusters, rust preventives, antiseptic / antifungal agents, antioxidants, evaporation promoters, 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 represents ethylene oxide and PO represents propylene oxide.

Example 1 After sufficiently stirring with the above composition, it was filtered with a Fluoropore filter having a pore size of 1 μm (trade name of a filter manufactured by Sumitomo Electric Industries, Ltd.) to obtain an ink of the present invention.

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

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

Example 4 MA-100, demole N, and triethanolamine were mixed and dispersed with a triple roll in the above composition, and the remaining components were gradually added to give the above composition.
The ink of the present invention was obtained by filtering with a μ fluoropore filter.

Comparative Example 1 An ink was obtained in the same manner as in Example 1 except that the EO adduct of arabinose of Example 1 was replaced with polyethylene glycol 400 (average molecular weight 400).

Comparative Example 2 An ink was obtained in the same manner as in Example 4, except that the stearyl ether of the EO adduct of arabidol in Example 4 was replaced with the stearyl ester of the EO adduct of arabidol.

Application Example 1 Table 1 shows the physical property values of the inks of Examples 1 to 4 and Comparative Examples 1 and 2, and the print evaluation results and storage stability evaluation results when printed with an ink jet printer.

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

Regarding the rate of bleeding, after printing 300 dots on a continuous slip sheet on the market 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 △: 16-40% ×: 41% or more Regarding the drying property of the print, after printing alphanumeric characters on a commercial continuous slip paper with a printer, 10, 20, 30, 40 , 5
After 0 and 60 seconds, the printed portion was rubbed with a paper filter (No. 2, trade name, manufactured by Toyo Tatsumi Co., Ltd.), and the judgment was made based on the number of seconds until the print became free of stains. (22 ± 5 ℃, 60 ± 10%
(Printed and measured with PH) ○: Within 20 seconds △: 20 to 40 seconds ×: 41 seconds or more For storage stability, put 100 cc of each ink in a heat-resistant glass bottle for 3 months in a constant temperature bath at 60 ° C. After saving, 100 sheets of continuous slip paper were printed with a printer and evaluated.

○: No abnormality ×: Abnormality (clogging, ejection failure, discoloration, etc.) [Effect] The ink of the present invention is particularly suitable for use as an ink for ink jet printers because it has less bleeding on printed matter and excellent drying properties.

Further, the alkylene oxide adduct of pentose or its sugar alcohol and / or the alkyl, alkenyl or aryl etherified product of the adduct used in the present invention does not contain an ester structure in its molecule, and is conventionally known. Like a sorbitan ester-based or sucrose ester-based surfactant, it is stable without being hydrolyzed in an aqueous liquid medium, and the storage stability of the ink itself is also good.

Furthermore, the inks of Examples 1 to 4 were used in an ink jet printer, and printing was tested on an OHP film for an ink jet printer and a broad cloth made of 100% cotton. All of them showed little bleeding and good printing was possible. became.

Claims (1)

[Claims] 1. An inkjet recording ink mainly composed of a recording medium and a liquid medium in which the recording medium is dissolved or dispersed, wherein an alkylene oxide adduct of pentose or a sugar alcohol thereof and / or an alkyl or alkenyl of the adduct. Alternatively, an inkjet recording ink containing an aryl ether compound.