JP2001026732A - Jet ink composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a jet ink composition having low foaming properties, stable ink-jet characteristics, capable of forming a print not penetrating a fluorescent dye from the surface to the interior of paper and high surface density of fluorescent dye. SOLUTION: This jet ink composition comprises one or both of fluorescent dyes of europium thenoyl trifluoroacetone and H.I.D.C. Iodide (CAS registration numer 36,536-22-8). A binder comprises one or both of maltosyl cyclodextrin and a styrenesulfonic acid-maleic anhydride copolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jet ink composition containing a fluorescent dye, and more particularly to a jet ink composition capable of forming a printed matter having a low foaming property and a high fluorescence emission property.

[0002]

2. Description of the Related Art When printing is performed by an ink jet printer, ink droplets are formed, and are ejected from nozzles onto a recording medium to form images such as prints, figures, lines, and the like. For this reason, inkjet printing requires a jet ink composition having an appropriate viscosity and surface tension.To satisfy such requirements, conventionally, as a binder of the jet ink composition, polyhydric alcohols, glycol ethers, glycol Ether esters, pyrrolidone, P
VA and the like have been used. However, when the above-mentioned binder is used in a jet ink composition containing a fluorescent dye, which is described in JP-A-06-107992, the composition foams at the time of ink ejection, and the ink jetting characteristics become unstable. The problem is that the fluorescent dye diffuses and penetrates deep from the surface of the paper together with the binder to lower the surface density of the fluorescent dye, resulting in low fluorescence emission intensity on the surface of the printed matter. There was a point.

[0003]

SUMMARY OF THE INVENTION The present invention solves the problems of the conventional jet ink compositions containing a fluorescent dye, has low foaming properties, has stable ink jetting properties, and has a fluorescent dye which is used in paper. An object of the present invention is to provide a jet ink composition which does not penetrate from the surface to the inside and forms a print having a high surface density of a fluorescent dye.

[0004]

Means for Solving the Problems The present inventors have conducted research to solve the above problems, and as a result, have found that a binder containing maltosyl cyclodextrin and / or a styrenesulfonic acid-maleic anhydride copolymer is used. By doing so, the foaming property of the jet ink composition containing the fluorescent dye is reduced, and the ink jetting characteristics are stabilized, so that it is possible to print accurately at the target position, and the jet ink composition is coated on the surface of the paper together with the fluorescent dye. , The density of the fluorescent dye on the surface of the printed matter was increased, and a finding was obtained that a printed matter having high fluorescence was obtained. The present invention is an invention made based on this finding.

That is, the present invention relates to europium-thenoyltrifluoroacetone and H. I. D. C. Iodid
e (CAS registration number 36536-22-8) comprising one or both of the fluorescent dyes, wherein the binder is one or both of maltosyl cyclodextrin and a styrene sulfonic acid-maleic anhydride copolymer. A jet ink composition comprising:

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

[0007] Maltosyl cyclodextrin used as a binder in the present invention is an oligosaccharide of maltose, and can be efficiently produced by polymerizing maltose using the enzyme pullulanase. Usually, the component of the product obtained by the enzyme pullulanase contains maltosyl cyclodextrin in an amount of 50% by weight or more, and the weight ratio of α, β and γ-forms therein is 6: 3: 1. Although existing cyclodextrins have a disadvantage that they are hardly soluble in water, maltosyl cyclodextrins are easily soluble in water. This maltosyl cyclodextrin not only has high water solubility, but also has high solubility in various organic solvents, so that various fluorescent dyes can be widely included. Maltosyl cyclodextrin is a powder, but when a fluorescent dye is included, it is dissolved in water before use. Maltosyl cyclodextrin is easy to handle if it is in an aqueous solution having a solid content of 20 to 70%.

The styrene sulfonic acid-maleic anhydride copolymer used as a binder in the present invention is a low molecular weight resin obtained by copolymerizing a styrene sulfonated polymer and maleic anhydride, and preferably has a weight average molecular weight. 1,000 to 10,000, more preferably 2,000
９9,000. The reason why such a weight average molecular weight is preferable is that when the weight average molecular weight is smaller than 1,000, the performance as a binder tends to decrease, and when the weight average molecular weight is larger than 10,000, the formed dots are liable to cause stringing, resulting in poor printing. Because it is easy. The styrene sulfonic acid-maleic anhydride copolymer used in the present invention is non-foamable and has good dyeing properties. Each of these binders may be used alone, or both may be used in combination. In this case, maltosyl cyclodextrin 100
The styrene sulfonic acid-maleic anhydride copolymer is preferably used in an amount of 1 to 500 parts by weight, more preferably 5 to 300 parts by weight, particularly preferably 5 to 100 parts by weight, based on parts by weight. The reason that the amount of the copolymer is preferable is as follows.
If the amount is more than 500 parts by weight, the viscosity of the ink tends to exceed the applicable range, and the printing characteristics tend to be poor.

The fluorescent dye used in the present invention may be europium-thenoyltrifluoroacetone and / or H. I.
D. C. Iodide (CAS registration number 36536-2
2-8) is preferably used, but it is also possible to use those commonly used in jet ink compositions in combination.
As the fluorescent dye used in combination, a basic fluorescent dye is preferable,
Specific examples include CIBasic Yellow 35,40, CIBasic
Red 1,1-1, CIBasic Violet 11: 1, CIBasic Blue
7 and the like.

[0010] The main solvent of the jet ink composition of the present invention is distilled water or ion-exchanged water, preferably 30 to 99.5% by weight, more preferably 40 to 90% by weight based on the total weight of the jet ink composition. It is used so as to be% by weight. Further, as a solvent other than water, a water-miscible organic solvent can be added. Specific examples include alcohols such as methyl alcohol, ethyl alcohol and isopropyl alcohol, dioxane, acetone, methyl ethyl ketone, carbitols and the like, and these can be used alone or in combination of two or more. The amount used is preferably 0.1 to the entire jet ink composition.
To 50% by weight, more preferably 0.5 to 40% by weight.

The jet ink composition of the present invention contains the above-mentioned maltosyl cyclodextrin and / or styrene sulfonic acid-maleic anhydride copolymer and a specific fluorescent dye as main components, and further, if necessary, paratoluene sulfone. A curing catalyst such as an acid, hydrochloric acid, and sulfuric acid, a conductivity adjuster such as lithium nitrate, lithium nitrite, ammonium sulfite, ammonium formate, ammonium acetate, lithium halide, and sodium thiocyanate, and a surfactant may be added. . The addition amount of these components is 0.01% of the composition.
It is preferable to set it to 5% by weight.

The compositions of the present invention require properties that are compatible with ink jet printing. Therefore, the composition of the present invention has a viscosity of 1 to 10 mPa · s (20 ° C.) and a specific resistance of 2
Desirably, the specific gravity is in the range of 00 to 3000 Ωcm, specific gravity of 0.8 to 1.2, and surface tension of 20 to 60 dynes / cm. The composition of the present invention is prepared by mixing and stirring the above components, and then mixing the above components with a jet printer having a nozzle diameter of about 1/1.
This is performed by filtering and purifying with a filter having a pore size of 0 or less. The jet printer that can use the jet ink composition of the present invention is a conventionally known various printer, for example, a device that employs a printing method of a charge control method, an ink-on-demand method, or a method of ejecting ink by a thermal head is representative. Can be cited.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments. In the examples, “parts” and “%” are based on weight.

[Examples 1 to 4 and Comparative Examples 1 to 3] The fluorescent dye, the binder and the solvent were uniformly mixed at the compounding ratios shown in Table 1, followed by filtration and purification through a membrane filter having a pore size of 1.0 μm. Then, jet ink compositions corresponding to each example and each comparative example were prepared.

[0015]

[Table 1]

Note 1) Ink was added to 100 ml of polyvin
After 0 to 80 ml was added and the stopper was closed, the time until the bubbles on the ink liquid surface disappeared after 10 inversions was measured.

：: When it is 60 seconds or less (good) X: When it takes longer than 60 seconds (it causes printing failure) Note 2) Dot printing on paper with a jet ink printer and print the brightness Relative value of the value measured using.
(Available for more than 100)

As is clear from Table 1, Examples 1 to 4 in which the maltosyl cyclodextrin of the present invention and styrene sulfonic acid-maleic anhydride copolymer were used as the binder had good foaming properties and fluorescence emission intensity ratios. Met.
Comparative Example 1 using PVA (Povar) as a binder
Is poor because the foaming property takes longer than 60 seconds and the fluorescent emission intensity ratio is also poor. Comparative Example 2 using ethylene glycol as the binder was inferior in both foaming property and fluorescence emission intensity ratio. Further, as a binder, n-
Comparative Example 3 using methyl-2-pyrrolidone had a poor fluorescence emission intensity ratio.

[0019]

The jet ink composition of the present invention has a molecular weight as large as possible within a range not causing stringing, is solid at room temperature, is water-soluble, and does not foam its aqueous solution, ie, maltosyl. By using cyclodextrin and / or styrene sulfonic acid-maleic anhydride copolymer, the ink dots can be accurately jumped to a desired position, and the water of the droplets can penetrate inside the paper first, and the maltosyl cyclodextrin can be obtained. And / or the surface concentration of the styrene sulfonic acid-maleic anhydride copolymer and the fluorescent dye is increased, and a large amount is precipitated on the paper surface. Therefore, since the fluorescent dye and the binder are present in a large amount on the paper surface, the fluorescence intensity is increased.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tsuneo Shirota 1-18-3 Nakazato, Minato-ku, Yokohama-shi, Kanagawa Prefecture No. 31 102 F-term (reference) 2C056 FC01 2H086 BA56 BA59 BA62 4J039 AB01 AD03 AD14 AD22 BE02 BE16 CA03 CA06 EA15 EA16 EA17 EA27 EA28 EA42 EA44 EA46 GA24

Claims (2)

[Claims] 1. Europium-thenoyl trifluoroacetone and H. I. D. C. A jet ink composition comprising one or both of the fluorescent dyes of Iodide (CAS Registry Number 36536-22-8), wherein the binder is one or both of maltosyl cyclodextrin and a styrene sulfonic acid-maleic anhydride copolymer. A jet ink composition comprising: 2. The jet ink composition according to claim 1, wherein the binder contains 1 to 500 parts by weight of a styrenesulfonic acid-maleic anhydride copolymer based on 100 parts by weight of maltosyl cyclodextrin. .