JPS58204067A - Ink composition for ink jet printer - Google Patents

Abstract

PURPOSE:To provide an ink compsn. which little causes the clogging of a nozzle, containing a specified dye, triethylene glycol, triethanolamine, sodium ethylenediaminetetraacetate, 1,2-benzisothiazolin-3-one and water. CONSTITUTION:An ink compsn. contains 3-5wt% dye having a color index number of 35255, 15-25wt% triethylene glycol, 0.2-0.4wt% triethanolamine, 0.2-0.4wt% trisodium or tetrasodium ethylenediaminetetraacetate, 0.05-0.1wt% 1,2-benzisothiazolin-3-one and the balance of water.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ink composition used in an inkjet glitter.

When an ink piercing type printer that uses all water-based ink is stopped for a long time, substances with high vapor pressure, such as water, evaporate from the ink surface at the ink ejection nozzle, causing the ink to become viscous. becomes high, dyes, etc. precipitate, and even if ink is pushed out with a predetermined pressure, no ink is ejected, which is called clogging. Therefore, conventional ink compositions include substances with relatively low vapor pressure such as polyethylene glycol, N-vinyl-2-pyrrolidone, and N-methyl-2-pyrrolidone, which have a molecular weight of about 200 to 600, and then evaporate. It was suppressed and prevented eye redness I7. However, as the molecular weight of high molecular weight polyethylene glycol increases, the viscosity increases and the solubility of the dye decreases. Furthermore, since -10,000N-vinyl-2-pyrrolidone has a sterilizing effect on piping systems, it has the power to dissolve the resin in the piping systems, so there was a risk that the dissolved substances would cause nozzle clogging. Additionally, when microorganisms enter the ink and appropriate conditions are met, hyphae grow from the spores, which also causes nozzle clogging.

Therefore, conventional ink contains 2-pyridinethiol-1-
Oxide sodium salt, 2-4-thiazolyl-penzimidazole, etc. were added as so-called anti-crystal agents, JIS Z 291if19'761r.
According to the "Mold Resistance Test Method", the mold still remained for t minutes, and mold was generated, resulting in nozzle clogging.

The purpose of the invention is to eliminate the above-mentioned drawbacks of the prior art, to reduce the increase in ink viscosity caused by water evaporation of this type of ink, and to create an ink that is less likely to cause nozzle clogging by suppressing the growth of microorganisms. An object of the present invention is to provide a composition.

In the present invention, the vapor pressure of triethylene glycol is low, the viscosity of the aqueous solution is low, the dissolution change of the dye having a brown index number of 35255 is large, and the content of 1.2benz1notiazoline is excellent within a predetermined range. The compounding ratio of the ink composition has been devised to take advantage of its ability to inhibit mold.

The ink composition of the present invention YC is a color having the following chemical structure.
fN Number * Method 55255
NNa0aS 80sNa ethylene glycol, triethanolamine, ethylenediaminetetraacetic acid hexasodium salt or ethylenediaminetetraacetic acid tetrasodium salt, 1,2benzisothiazoline 6-ono having the following chemical structure, and water.

The dye imparts a predetermined hue to the ink, and requires a concentration of 3 to 5% by weight in order to achieve a reflection density of around tto on printed paper.

Triethylene glycol gives ink wettability and is used to prevent dyes and other substances from precipitating after water evaporates and causing clogging. FIG. 1 shows the results of the rill determination of the viscosity f 20 'C of an aqueous solution of polyethylene glycol of about 200 to 600 and triethylene glycol of the present invention. As can be seen in Figure 1, if the concentrations are the same: - Liethylene glycol has a lower viscosity than ethylene glycol, so it is less likely to cause clogging. Furthermore, the solubility of the dye with color index number 35255 is $J7% by weight at 20°C for triethylene glycol, whereas it is f'1. is approximately 2 to 3.5% by weight at 20 DEG C. Also from the viewpoint of dye solubility, the ink used on triethylene glycol has little precipitation of dye, etc. and is less likely to cause clogging. Considering the drying properties of characters or symbols on printed printing paper, the amount of triethylene glycol that can be used for practical purposes within 5 seconds at 20°C is 15%.
~25% by weight. Triethanolamine is used to completely counterfeit the entire ink, and in order to maintain the pH at 9 to 11, it must be 12 to 0.4%. Ethylenediaminetetraacetic acid pentasodium salt is also When using ethylenediaminetetraacetic acid tetrasodium salt H,1 ink for inkjet printing, metal ions such as Fθ and Mg get mixed into the ink, forming water l/'C insoluble precipitate #lJ and causing clogging. In order to prevent clogging by making the metal chelate soluble in any water,
．． 4% by weight is required. 1.2 Benzinthiazoline
6-ON is used to prevent microorganisms from propagating in the ink, and its mold resistance test is conducted according to JIS 22.
Table 1 shows the results obtained in accordance with 911N976J "Mold Resistance Test Method". The composition of the ink in this case is exactly the same except that 1.2% by weight of benzisothiazolin-6-one and water (kW) was added in the following example.

(Example) Materials Concentration (wt%) Dye with color index number 35255 4,5 triethylene glycol 20.0 triethanolamine 0,6 ethylene diamine tetraacetic acid tetrasodium salt 0.31.2 be73 inch azoline 3-one 0.07 water
Remaining amount Table 1: Test results for scratch resistance (5) From the results in Table 1, the amount of ink for normal inkjet printers is 1.2 inches of azoline-6-one.
j a 05 to 0.1% by weight is required.

In addition, in the case of the above example, the physical properties at 20°C 1st shift (
142 The following is as follows.

Table 2 Physical properties of ink 2F: According to the invention, even if the water evaporates, the viscosity increases, and the dye dissolves at 7v! The ink contains triethylene glycol, which has a high concentration, and 1,2-benzisothiazolin-3-one, which suppresses the growth of microorganisms, so even if the water evaporates, it will not clog. It is possible to provide an ink composition for an inkjet printer that does not cause problems and has a stable lifespan.

[Brief explanation of the drawing]

Figure 1 shows polyethylene with a molecular weight of 200 to 400! This is a custom-made diagram showing the viscosity determined by a Cannon-Fence type viscometer and a floating scale type hydrometer (1) with a viscosity divided into 20'C after a water bath of nokol and triethylene glycol.

Claims (1)

[Claims] The ink composition contains a dye having color index number 35255i at a concentration of 6-5% by weight and 15-25% by weight in the ink composition! ! triethylene glycol contained in the ink composition with a conductivity of 0.2 to 0.4% by weight, and triethanolamine contained in the ink composition with a conductivity of 0.2 to 0.4% by weight. ethylenediaminetetraacetic acid hexasodium salt or ethylenediaminetetraacetic acid tetrasodium salt contained in a concentration of An ink composition for an inkjet printer, comprising: an amount of water.