JP2000214152A - Oxygen indicator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an oxygen indicator from being degraded when the indicator is irradiated with light or when the indicator is stored in a high-temperature environment by a method wherein an optical/thermal stabilizer is given to the oxygen indicator which is composed of an oxidation-reduction pigment, a reducing agent used to change the pigment into a reduction type and water or alcohol. SOLUTION: An optical/thermal stabilizer is given to this oxygen indicator which is composed of an oxidation-reduction pigment, a reducing agent in an amount capable of changing the pigment wholly into a reduction type and water or alcohol. As the oxidation-reduction pigment, neutral red or the like is used in addition to methylene blue or the like. In addition, as the reducing agent, a reducing sugar such as erysorbic acid or its salt, a metal salt or the like such as a stannous salt, a ferrous salt or the like can be used in addition to ascorbic acid. In addition, the oxygen indicator is used desirably in such a way that it is carried by a carrier such as an alkaline-earth metal compound such as calcium hydroxide, magnesium hydroxidide or the like, a metal oxide, zeolite or the like. When it is used as a solid state, it is desirable that a coupling agent such as cellulose, a polymer compound or the like is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oxygen indicator provided with heat resistance and light resistance by adding a light / heat stabilizer to an indicator for determining the state of deoxygenation by an oxygen absorbent.

[0002]

2. Description of the Related Art It is known that oxygen oxidizes foods and pharmaceuticals due to its high reactivity and causes deterioration. Many foods and medicines prevent degradation by coexisting with oxygen absorbers.
An oxygen indicator is simultaneously turned on to detect the entry of oxygen due to a bad seal or the like. At present, several types of oxygen indicators having different combinations of redox dyes, reducing agents, binders and the like are on the market. The oxygen indicator utilizes the property that the redox indicator exhibits different colors between the reduced form and the oxidized form.Methylene blue, which is generally used, is reduced to colorless, that is, colorless by the action of the reducing agent under anoxic condition. It is oxidized by oxygen under aerobic conditions and exhibits a blue color.

[0003] Further, there has been developed an indicator which can easily confirm discoloration by mixing two or more kinds of dyes.

[0004] The shape of the oxygen indicator is liquid, tablet,
There are a wide variety of types such as ink type, sheet type, and paper type. Further, an oxygen absorber-integrated type and a packaging material-integrated type have been developed, and efforts have been made to save labor upon introduction.

[0005] Several types of oxygen indicators using redox dyes are on the market. However, many dyes are discolored or decomposed by light irradiation, and the indicators may be deteriorated even at an illuminance of about a fluorescent lamp. In other words, it must be stored in a dark place, and there is a problem in its light resistance.

However, in the case of a packaging material in which the contents are visible, the oxygen indicator has a risk of being exposed to light, and due to its nature, the indicator must be installed at a position where it can be seen from the outside. When the contents are distributed for a long time, the oxygen indicator is more likely to be deteriorated by light, and thus it has been desired to provide light resistance.

In addition, many dyes are discolored or decomposed not only by light but also by heat, causing deterioration of the oxygen indicator.

It is known that the oxygen indicator is exposed to high temperatures during storage after production and during product distribution, causing discoloration and poor coloring of the oxygen indicator.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and it is an object of the present invention to prevent deterioration due to light irradiation on an oxygen indicator or storage in a high-temperature environment. Things. Stabilization of the oxygen indicator also allows for long-term distribution and long-term quality assurance of products protected by the oxygen scavenger.

[0010]

SUMMARY OF THE INVENTION The present invention has been conceived in order to solve the above-mentioned problems, and the invention of claim 1 comprises at least an oxidation-reduction dye and an amount of reduction capable of converting all the dyes to a reduced form. An oxygen indicator comprising a light / heat stabilizer added to an oxygen indicator comprising an agent and water or alcohol.

According to a second aspect of the present invention, the redox dye comprises methylene blue, the reducing agent comprises ascorbic acid, and the light / heat stabilizer comprises a hindered amine-based agent.
It is an oxygen indicator of description.

A third aspect of the present invention is the oxygen indicator according to the first or second aspect, wherein the amount of the light / heat stabilizer is from 100 ppm to 10,000 ppm.

[0013]

Next, an embodiment of the present invention will be described in detail. Redox dyes include methylene blue, new methylene blue, neutral red, indigo carmine, acid red, safranin T, phenosafranine, capri blue, nile blue, diphenylamine, xylene cyanol, nitrodiphenylamine, ferroin, N-phenylanthranilic acid, etc. Can be used.

As the reducing agent, erythorbic acid and salts thereof, ascorbate, D-
Arabinose, D-erythrose, D-galactose,
D-xylose, D-glucose, D-mannose, D
-Reducing sugars such as fructose and D-lactose; metal salts such as stannous salts and ferrous salts;

The oxygen indicator is desirably used by being supported on a carrier such as an alkaline earth metal compound such as calcium hydroxide or magnesium hydroxide, a metal oxide, or zeolite. When used as a solid, it is desirable to use a binder such as cellulose or other polymer compound.

Further, when the concentration of the light / heat stabilizer is 100 p
pm, the effect is not sufficiently exhibited.
If it is 000 ppm or more, the effect is not only saturated, but also discoloration of the redox dye is inhibited, and its detection function is inhibited.

The oxygen indicator according to the present invention can be printed on a film or the like irrespective of its form, such as powder, liquid, solid, etc., as well as a sheet impregnated with filter paper, etc., or mixed with ink. It is.

In the oxygen indicator according to the present invention, the light / heat stabilizer stabilizes oxygen radicals and active oxygen activated by light and heat energy, prevents deterioration of the oxidation-reduction dye due to oxidation and decomposition, etc. Is maintained.

[0019]

Embodiments of the present invention will be specifically described below. <Example> Methylene blue was used as a redox dye in an amount of 0.0
14 parts by weight, L-ascorbic acid as a reducing agent is 2.0
Parts by weight, 27 parts by weight of cellulose as a binder, 51 parts by weight of zeolite as a supporting substance, 20.086 parts by weight of water, and bis (1,2,2,2) as a light / heat stabilizer during mixing. 6,6-Pentamethyl-4-piperidinyl) sebacate at a final concentration of 1000p
pm so as to obtain tablets.

Comparative Example 0.014 parts by weight of methylene blue as a redox dye, 2.0 parts by weight of L-ascorbic acid as a reducing agent, 27 parts by weight of cellulose as a binder, and 51 parts by weight of zeolite as a supporting substance , Water 2
An oxygen indicator consisting of 0.086 parts by weight was tableted.

[Experiment 1] The oxygen indicator was released from an anoxic state to an aerobic state, and its discoloration was observed.

[Experiment 2] The oxygen indicator was irradiated with a 1000 Lux fluorescent lamp under aerobic conditions to observe discoloration.

[Experiment 3] The above oxygen indicator was replaced with KO
It was placed in a P / PE (vinylidene chloride copolymer-coated biaxially oriented polypropylene / polyethylene) packaging material, replaced with nitrogen or carbon dioxide, and anaerobically sealed. 1 in anoxic condition
The sample was irradiated with a 000 Lux fluorescent lamp, and discoloration was observed.

[Experiment 4] The oxygen indicator was left at 55 ° C. in an oxygenated state, and discoloration was observed.

[Experiment 5] The above oxygen indicator was replaced with KO
Put in P / PE packaging material and replace with nitrogen or carbon dioxide,
Anaerobic sealed. It was left at 55 ° C. in an oxygen-free state, and discoloration was observed.

Table 1 shows the results of Experiment 1.

[0027]

[Table 1]

Upon release from the oxygen-free state to the aerobic state, the color rapidly changed from white to blue within 5 minutes in both the examples and comparative examples. Table 2 shows the results of Experiment 2.

[0029]

[Table 2]

Table 3 shows the results of Experiment 3.

[0031]

[Table 3]

Table 4 shows the results of Experiment 4.

[0033]

[Table 4]

Table 5 shows the results of Experiment 5.

[0035]

[Table 5]

From the results of Experiment 1, it was shown that the oxygen indicator of the present invention immediately detects oxygen and changes its color when released from an anoxic state to an aerobic state. Further, from Experiments 2 to 5, when light was irradiated under aerobic conditions, the oxygen indicator of the comparative example faded, but the indicator to which the light / heat stabilizer was added did not change color. In addition, when light irradiation was performed under oxygen-free conditions, the color of the comparative example was developed in both cases of nitrogen substitution and carbon dioxide substitution, whereas the example remained white. When left at 55 ° C. under aerobic conditions, the comparative example faded, making it difficult to distinguish it from a white state under anoxic conditions. The examples did not fade. On the other hand, when left at 55 ° C. in an oxygen-free state, the Example remained white in both cases of nitrogen substitution and carbon dioxide substitution, but the Comparative Example turned green-white. The results of Experiments 2 to 5 show that the oxygen indicator of the comparative example fades in color when exposed to light or heat in an aerobic state, and the ability to detect the presence or absence of oxygen is reduced. On the other hand, it was confirmed that even when exposed to light or heat in an anoxic state, the color changed from white to green-white, and the detection ability was reduced.
On the other hand, in the oxygen indicator of the example, such fading or coloring was not observed, and it was shown that the oxygen indicator according to the present invention has light resistance and heat resistance. By adding a light / heat stabilizer, the influence of light or heat on the oxygen indicator was eliminated, and the oxygen detection ability could be maintained.

Further, in the above-described embodiment, the solid type oxygen indicator which has been compressed has been described. However, the present invention is not limited to this.
A shape such as an ink type is also possible.

[0038]

The oxygen indicator of the present invention is obtained by adding a light / heat stabilizer to an oxygen indicator comprising a redox dye, an amount of a reducing agent capable of converting all the dye into a reduced form, and water or alcohol. An oxygen indicator that imparts light resistance and heat resistance and maintains oxygen detection ability for a long period of time can be provided.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takashi Urata 1-5-1, Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd. F-term (reference) 2G042 AA01 BB09 CA01 CB01 DA08 FA05 FA13 FA19 FA20 FB05 GA04

Claims (3)

[Claims] An oxygen indicator characterized in that a light / heat stabilizer is added to an oxygen indicator comprising at least a redox dye, an amount of a reducing agent capable of converting all the dye into a reduced form, and water or alcohol. . 2. The oxygen indicator according to claim 1, wherein the redox dye comprises methylene blue, the reducing agent comprises ascorbic acid, and the light / heat stabilizer comprises a hindered amine agent. 3. The oxygen indicator according to claim 1, wherein the concentration of the light / heat stabilizer is from 100 ppm to 10,000 ppm.