JPH05320559A - Water-based fluorescent ink - Google Patents

Abstract

(57) [Abstract] [Purpose] When applied to OA paper such as thermal paper or pressure-sensitive paper, a water-based fluorescent ink that is hard to discolor and does not erase the printing and gives a handwriting with improved light resistance is obtained. [Structure] Hydroxypyrenetrisulfonic acid, basic substances, water and reduced lactose, hydroxypropyl (α-, β-
Alternatively, an aqueous fluorescent ink containing one or more saccharides selected from γ-) cyclodextrin, dimethyl β-cyclodextrin, glycosyl (α-, β- or γ-) cyclodextrin, and fructooligosaccharides.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink for a fluorescent underline marker used for highlighting a desired portion of a document, and in particular, an aqueous fluorescent ink suitable for use in OA paper such as thermal paper and pressure-sensitive paper. Regarding

[0002]

2. Description of the Related Art Aqueous fluorescent inks using hydroxypyrenetrisulfonic acid (yellow fluorescent color) as a fluorescent dye and a basic substance as a color-forming aid are widely known (for example, Japanese Patent Publication No. 59-453). , Is commonly used.

[0003]

Among the above-mentioned aqueous fluorescent inks, the handwriting on the thermal paper due to the ink using triethanolamine as the basic substance is likely to be discolored (darkened),
In addition, pressure-sensitive paper has a drawback that the print is erased. When an inorganic base such as sodium carbonate or sodium hydroxide is used, the handwriting tends to be lightened when exposed to sunlight or fluorescent light. When glycols are used as a wetting agent in the ink, the print on the pressure-sensitive paper tends to be erased. The present invention is intended to provide an aqueous fluorescent ink that solves the above problems.

[0004]

The aqueous fluorescent ink of the present invention comprises hydroxypyrenetrisulfonic acid, a basic substance, saccharides and water as essential components. The saccharides include reduced lactose, hydroxypropyl (α-, β- or γ-) cyclodextrin (hereinafter cyclodextrin is abbreviated as CD), dimethyl β-CD, glycosyl (α-, β-).
Or 1 selected from γ-) CD and fructooligosaccharides
There are two or more species. These sugars are contained in the ink composition,
It is used in the range of 5 to 70% by weight, preferably 10 to 30% by weight. Regarding other essential components, hydroxypyrenetrisulfonic acid is used in the ink composition in the range of 0.1 to 20% by weight, and the basic substance is used in the range of 0.1 to 20% by weight. In addition, if necessary, glycerin in an amount of 10% by weight or less as a wetting agent and a small amount of an additive such as a surfactant or a preservative are added, and the balance is water.

[0005]

The above-mentioned saccharides surround the dye by interacting with hydroxypyrenetrisulfonic acid in the ink to form OA.
It is considered that in the handwriting on the paper, direct contact between the coating component of the paper and the dye is prevented to prevent discoloration, and the light resistance of the handwriting is improved by the same protective effect.

[0006]

EXAMPLES Example inks and comparative inks having the compositions shown in Table 1 were prepared as sample inks.

[Table 1] All numerical values of compositions in the table are expressed in parts by weight. Each sample ink was prepared by mixing glycerin, saccharides, a basic substance and other additives in water, adding hydroxypyrenetrisulfonic acid into an aqueous medium, and stirring and dissolving the mixture. 4 mm of each sample ink made of fiber bundle resin processed body
A marking pen provided with a φ-shaped rod-shaped pen body and a fiber bundle ink storage body was filled in predetermined amounts to prepare a sample pen. Each sample pen was used to make a sample by marking a linear handwriting (all handwriting showed yellow fluorescence) on the thermal paper, the printed pressure-sensitive paper, and the high-quality paper surface. For the pressure-sensitive paper, the change in handwriting after 1 minute was observed, and for the high-quality paper, the change in handwriting after 5 hours of exposure to a carbon arc fade-o-meter was visually observed.

The results are shown in Table 2.

[Table 2] The contents of the symbols in Table 2 are as follows. (1) Handwriting on thermal paper ○: No change was observed △: Lighter color ×: Darker (no fluorescence) (2) Printing on pressure-sensitive paper ○: No change was found ×: Erased (3) Light resistance of handwriting ○: No change was observed ◇: Slightly lightened △: Fairly lightened ×: Browned (no fluorescence)

[0008]

As shown in the results of Table 2, when the water-based fluorescent ink of the present invention is applied to heat-sensitive paper or pressure-sensitive paper, the handwriting thereof is compared with the handwriting of the comparative ink containing no saccharide. Then, the effect of suppressing discoloration is remarkably exhibited, and in addition, the improvement of light resistance is also recognized.

Claims (1)

[Claims] 1. An essential component containing hydroxypyrenetrisulfonic acid, a basic substance, a saccharide and water, wherein the saccharide is reduced lactose, hydroxypropyl (α-, β- or γ-) cyclodextrin, dimethyl β. -Aqueous fluorescent ink which is one or more selected from cyclodextrin, glycosyl (α-, β- or γ-) cyclodextrin and fructooligosaccharide.