JPH0768507B2 - Period elapsed display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a time-lapse indicator, and in particular to certain processed foods (improved noodles, oil confectionery, half-baked confectionery, etc.),
Effective for pharmaceuticals (antibiotics, vaccines, etc.), insect repellents, deodorants, bactericides, refrigerant gases, films and photographic papers, photosensitive papers, cosmetics, batteries, oils, chemicals that are sensitive to visible light and X-rays. Applicable to products for a limited period of time, or blood or components of blood for transfusion that also have a limited effective period,
The present invention relates to a time-lapse indicator (hereinafter referred to as a "time indicator" or simply "indicator") that enables the user to know at a glance whether or not it is within its valid period.

(Prior Art) The following is a method for expressing a period such as an expiration date of a product. For example, in a volatile drug, the active ingredient may be in the form of a solution or wax, and volatilization of these may be visually observed from the outside of the container. This type cannot be applied to all products because the properties of the active ingredient itself are limited to volatile ones.

Regardless of the active ingredient, there are indicators that use the volatility of the substance as an indicator of the period, and volatilization of colored liquids (including those absorbed in the gel) and volatilization of sublimable dyes reduce the degree of coloring. There is something to see. However, the volatilization of substances is greatly affected by temperature and humidity, and it is difficult to show an accurate period, and the volatilized substances may contaminate the surrounding air.

As another example, a time indicator that can judge the elapsed time by light, temperature, humidity, or color change due to gases such as oxygen (O ₂ ) and carbon dioxide (CO ₂ ) in the atmosphere can be considered.

However, light, temperature, and humidity change greatly in daily life, so the time indicators that use them change color before the scheduled period has passed, or even after the scheduled period has passed. It is difficult to get a stable time indicator because things such as no change occur. In addition, a bag made of a plastic film having a certain amount of oxygen permeability is filled with a colorant, such as methylene blue, that changes color depending on the amount of O _{2 in} the atmosphere, and the bag is sealed in a vacuum state, and this plastic film is aged over time. the O ₂ entering transmitted to, discolor the colorant, but thereby been studied a method of displaying the time that has elapsed, generally the oxygen transmission rate of plastic film varies depending on the temperature and humidity of the ambient, the Therefore, it is difficult to obtain a stable time indicator that can always display a certain period of time.

Furthermore, there is also a method in which CO ₂ is used instead of O ₂ , and a bag made of a plastic film having a certain amount of carbon dioxide gas permeability is used to change the colorant by changing the pH value due to the influence of atmospheric gas, This time indicator is
It has the drawback that the effective period of fragrance, deodorant, insect repellent, etc., that is, the period of several months to several years cannot be displayed, and the color changes in a shorter time (several hours to several tens of hours). Furthermore, because it is sensitive to the influence of humidity,
In such applications, it cannot be used as an indicator to indicate the passage of time.

(Problems to be Solved by the Invention) For the purpose of solving the above problems, the present inventors encapsulated a highly viscous liquid or gel-like substance in a container and colored the encapsulated substance in a part of the container. Alternatively, by previously providing a structure in which a dyeing substance that causes discoloration is localized, a stable period-lapse indicator that has not been affected by light, humidity, and other atmospheric gases has been previously proposed.

This period progress indicator uses the diffusion of the dyeing substance into a highly viscous liquid or gel-like substance (hereinafter, these are referred to as developed products), and the dyeing substance moves in the developed product over time. Since it is colored, it is intended to indicate the period by this colored amount or length. However, in this time-lapse indicator, the diffusion rate of the dyeing substance depends on the concentration of the developing substance, and shows a high diffusion rate in the developing substance of low concentration and a slow diffusion rate in the developing substance of high concentration. Further, when the developed product had a constant concentration over the entire container, the migration speed of the dyeing substance became slower with the passage of time, which was an error when reading the passage of time.

(Object of the invention) Therefore, the present invention can display the effective period of products such as insect repellents, fragrances, deodorants, that is, the progress of a period of several months to several years, and further, it can control light, humidity and other atmospheres. Invented as an indicator that is not easily affected by factors inside, a highly viscous liquid or gel-like substance is enclosed in a container, and a dyeing substance that colors or discolors the enclosed substance is localized in a part of the container. It is to correct the decrease in the moving speed of the dyeing substance when diffusing in the period elapsed display, and eliminate the error when reading the period elapsed.

(Means for Solving Problems) That is, according to the present invention, a highly viscous liquid or a gel-like substance is enclosed in a container, and a dyeing substance for coloring or discoloring the enclosed substance is localized in a part of the container. A time-lapse indicator which is characterized in that the diffusion rate of the dyeing substance in the container is controlled by giving a concentration gradient to the highly viscous liquid or gel-like substance. is there.

That is, it is preferable that the developed product has a concentration gradient that is the reciprocal of the diffusion equation of the above-mentioned dyeing substance so that the terminal end side of the diffusion becomes low in concentration, so that the migration speed of the dyeing substance due to diffusion becomes constant over time. It is what

However, under the present circumstances, it is difficult to provide the developed product in the container with the above-mentioned concentration distribution. Therefore, the developed product is developed by gradually lowering the concentration of the developed product from the starting point side where the dyeing substance diffuses. By giving a partial difference in the concentration of the substance so as to make the diffusion rate of the dyeing substance approximately constant, it is possible to eliminate an error when reading the passage of time.

(Detailed Description of the Invention) Hereinafter, an example in which a cylindrical object is used as a container will be described with reference to the drawings in order to explain the present invention in an easily understandable manner.

1 (a) and 1 (b) are cross-sectional explanatory views for easily understanding the present invention. The main body (1) and the lid body (2) are tubular bodies. The inside of FIG. 1 (a) is filled with a highly viscous liquid or gel-like expanded product (3) having a concentration gradient that is the reciprocal of the diffusion equation or having a low concentration near the end point. The inside of (2) is filled with a dyeing substance (4) for coloring or discoloring the developed product (3). A cutout line (6) for exposing the developed product (3) is provided on the main body (1) of the tubular body, and the lid of the tubular body is provided for sealing the filled dye substance (4). A sealing cap (5) is attached.

At the start of the period display of the tubular body composed of these two parts, the user cuts the main body (1) of FIG. 1 (a) along the cut line (6) and opens the sealing cap (5) of the lid (2). removal,
Display can be started by combining these as shown in FIG. 1 (b). By doing so, the bag-colored substance (4) in the lid (2) diffuses into the developed product (3) in the main body (1), so that the main body (1) appears to be colored in appearance. Further, the end of the period is such that the progress of the period can be displayed when the main body is completely colored, or when a mark is placed on the main body (1) and the part is colored.

FIG. 2 (a) is a graph showing the temporal transition of the visible moving end due to the diffusion of the dyeing substance into the developed product having no concentration gradient.

FIG. 2 (b) is a graph showing the temporal transition of the visible moving end due to the diffusion of the dyeing substance into the developed product in which the concentration near the end point is made lighter and the concentration difference has two levels. .

FIG. 2 (c) is a graph showing the temporal transition of the visible moving edge due to the diffusion of the dyeing substance into the theoretical developed product having a concentration gradient that is the inverse of the diffusion equation.

According to Fick's law, the number of moles of a component that moves in a direction perpendicular to the plane through a unit area in a unit time at a constant temperature is proportional to the concentration gradient of the component at that position.

(Fick's first law) where J: diffusion rate (mol / cm ² ) D: diffusion coefficient (cm ² / sec) C: concentration (mol / cm ² ) X: distance (cm).

Here, D represents the difficulty of diffusion and is determined by the substance system, concentration, and temperature.

In other words, by making the end side thin so that the concentration gradient of the developed gel is 1 / J, it is theoretically possible to control the movement speed to be constant.

The spread product (3) described in the present invention may be anything having a property capable of delaying the diffusion of the dyeing substance (4) such as a liquid or a gel-like substance having a high viscosity. For example, the dyeing substance (4) is water-soluble. Examples include carboxymethyl cellulose, ethyl cellulose, sodium alginate, sodium polyacrylate, polyacrylamide, polyvinyl alcohol, polyvinylpyrrolidone, agar, starch and gelatin. , Polystyrene-based resins, polyester-based resins and the like.

As the dyeing substance (4) described in the present invention, the developed product (3)
It is necessary to be able to diffuse into the inside, and a dye system is suitable because it is easy to diffuse. Safranin T, indigo sulfonic acid,
Examples include phenosafranine, methylene blue, diphenylamine, diphenylbenzidine, p-nitrodiphenylamine, and the staining substance (4) used here is
It may be one in which these dyes are dissolved, or one in which the above highly viscous liquid or gel-like substance is mixed.

In the present invention, the tubular body refers to polyethylene, Teflon,
Acrylic resin, polycarbonate, a silicon tube, a glass tube, or the like is preferable, and a transparent or light-colored one whose contents can be visually observed from the outside is preferable.

(Example) Methylene blue 0.5 part as a dyeing material (parts by weight:
(The ratio is expressed in parts by weight), and prepared in a ratio of 99.5 parts of water is enclosed in a lid made of polyethylene tube with an inner diameter of 5 mmφ and a length of 1 cm. Each of the prepared products was gradually sealed in order from the one with the lowest concentration in a body consisting of a polyethylene tube with an inner diameter of 3 mmφ and a length of 6 cm, and when these were combined and brought into contact, the dyeing substance developed. The period is displayed because it diffuses and stains the inside.

At this time, although the moving speed of the coloring tip of the dyeing substance is also decreased at a short time interval, when the coloring tip reaches the low-concentration portion of the developed product, the moving speed is increased again until the end of the period is displayed. Over the long term cycle of
The display was made at an almost constant speed.

In addition, the indicator in which the concentration of the developed product in a larger amount in stages was more accurately displayed.

(Effects of the Invention) According to the present invention, the change of the moving speed at the time of diffusion of the dyeing substance is eliminated, or the moving speed near the end point, which has been conventionally reduced, is increased, and the error in reading the elapsed time is reduced. It has become possible to lose it.

In addition, the time-lapse display of the present invention tends to speed up the period display at a high temperature as compared to a low temperature, but a product whose lifetime is to be measured often deteriorates at a high temperature, which is just right. become.

[Brief description of drawings]

FIG. 1 (a) is a cross-sectional explanatory view showing one embodiment of the period elapsed display body of the present invention. FIG. 1 (b) is a sectional explanatory view showing an example of use of the period elapsed display body of the present invention. FIG. 2 is a graph showing the temporal transition of the visible moving end due to the diffusion of the dyeing substance into the developed product. (1) Cylindrical body (main body) (2) Cylindrical body (lid) (3) Developed product (4) Dyeing substance (5) Sealing cap (6) Cut line (7) Diffusion tip of dyeing substance

Claims (1)

[Claims] 1. A period progress indicator in which a highly viscous liquid or gel-like substance is enclosed in a container, and a dyeing substance for coloring or discoloring the enclosed substance is localized in a part of the container. A time-lapse indicator which controls the diffusion rate of the dyeing substance in the container by giving a concentration gradient to the highly viscous liquid or gel substance.