JPS61271361A - Ink composition - Google Patents

Abstract

PURPOSE:To provide an ink compsn. which allows the fading period of marked ink to be changed, whereby the days elapsed can be found, by adding a lower alcohol and water to a phthalein dye, allowing the resulting soln. to develop color in an alkaline pH range and adding an alkali metal carbonate thereto. CONSTITUTION:A phthalein dye such as thymolphthalein is dissolved in a 1-4C lower alcohol and water. The soln. is made alkaline by a strongly alkaline soln. such as NaOH and is allowed to develop color. An alkali metal carbonate (e.g. K2CO3) in an amount corresponding to a desired facing period is added to the soln. to obtain an ink compsn. whose hue is faded in 1-24 months.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ink composition for determining the number of days elapsed by naturally fading the hue marked with an ink made of a phthalein pigment developed by adding a caustic alkali and an alkali carbonate salt.

In daily life, it may be considered very convenient to be able to easily tell how many days have passed.

And it's not just a few days, it's a month, several months, or even a month.
The longer the time has passed, the more unclear the number of days that have passed, so even though certain functions have disappeared, the old form may still be used. For example, fungicides, fungicides, insect repellents, or deodorizers that have sublimation properties.

When used with deodorant etc. for each purpose,
It is very difficult to know when the drug has volatilized or expired. Traditionally used camphor, naphthalene, P-dichlorobenzene, etc. are molded into tablets, etc., without the use of fillers, so when these molded products disappear, the following Replenishment is easy.

However, although recent compounds are more expensive than conventional ones, many of them are also very effective. Also, the sublimability of these compounds.

The volatility is much lower than that of conventional compounds, so in order to exhibit sufficient effects, the compound must have good sublimation properties, and therefore the surface area must be increased. To do this, it is necessary to adsorb it onto paper, textiles, etc., or to use a porous material such as pumice stone or leech 5 as a carrier to increase the surface area. Even if a practical product is completed in this way and the initial purpose is achieved, the next problem is to predict when the compound will sublimate and volatilize and its efficacy will be zero or close to expiration. The rate of sublimation and volatilization depends on a large number of coefficients related to sublimation and volatilization, such as the vapor pressure of the compound, surface area, temperature, humidity, and air movement.
Taking disinfectants as an example, if the storage method is limited, the number of days for each type of disinfectant can be determined through experiments to determine when the compound will completely volatilize or reach a concentration that cannot meet the intended efficacy of the disinfectant. Therefore, there is a need for a method that can predict expiration according to the time, so by formulating ink according to the required number of days and marking accordingly, expiration can be determined by the fading of the ink. That's why. Although there are known methods for predicting the progress of a short period of time, from several hours to 70 days, in which fading of ink marked in this manner is applied, there is no method that can be used for a long period of time as in the present invention.

The present invention aims to notify a certain date within a long period of time, from 7 to 10 months, by a change in hue. This is an application of the following.

These phthalein dyes develop color when the pH value is adjusted using a strong alkaline solution such as caustic soda.

Lower alcohols such as dimethyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, and water are used as solvents. Furthermore, add carbonated soda to this liquid,
Potassium carbonate and the like are added, and it has been discovered that the fading period of the phthalein dye used can be easily changed by changing the amount of alkali carbonate added.

Apply this dye solution to paper. After stamping or coating on textiles, etc.
Colored products that have been dried can be discolored within a certain period of time as the number of days passes.O Examples will be described below.

5j! Example product Thymolphthalein dye fading test The above formulations &7 to +1 were absorbed into felt of baseness j at and stamped under the same conditions with initial printing type (rubber stamp).
Store it in the top small drawer of the metal pear office desk. The drawer was opened/mortar/times for about 10 seconds and then closed again.

Experiment period: Month/day y, 1960 - March 37, 1985 Number of days required for fading

Claims (1)

[Claims] Add a lower alcohol containing 1 to 4 phthalein pigments and water to develop the solution to a desired hue in an alkaline region, then add soda carbonate or potassium carbonate, and depending on the amount added, the hue will change over a period of 1 to 24 months. An ink composition characterized in that it is capable of fading.