JP2000214155A - Oxygen indicator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an oxygen indicator which is provided with high stability and heat resistance and which can maintain an oxygen detecting capability for a long period by adding an ultraviolet absorbent to the oxygen indicator which is composed of an oxidation-reduction pigment, a reducing agent in an amount capable of changing the pigment into a reduction type and water or alcohol. SOLUTION: As an oxidation-reduction pigment, new methylene blue or the like is used in addition to methylene blue, In addition, a metal salt or the like such as erysorboc acid, a ferrous salt or the like can be used in addition to ascorbic acid. In addition, this oxygen indicator is used desirably in such a way that it is carried by a carrier such as an alakline-earth metal compound such as calcium hydroxide or the like, a metal oxide or the like. As an ultraviolet absorbent, a benzotriazole-based chemical or the like can be used. In addition, when the content concentration of the ultraviolet absorbent is at 100 ppm or lower, its effect is not displayed sufficiently. When the content concentration is at 10000 ppm or higher, its effect reaches a saturation, it obstructs the discoloration of the oxidation-reduction pigment, and its detecting capability is obstructed.

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 an ultraviolet absorber to an indicator for judging a deoxygenated state by an oxygen absorber.

[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] It is known that ultraviolet rays have high energy and give various changes to substances. There are several types of oxygen indicators on the market that use redox dyes. However, when exposed to ultraviolet light, these indicators may be discolored, decomposed, and deteriorated.

However, in a packaging material in which the contents are visible, the oxygen indicator may be exposed to sunlight or the like,
Also, due to the nature of the indicator, it is necessary to install the indicator at a position visible 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.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and has as its object to develop an oxygen indicator which does not deteriorate even when irradiated with light such as sunlight. It is. Stabilization of the oxygen indicator also allows for long-term distribution and long-term quality assurance of products protected by the oxygen scavenger.

[0008]

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. The present invention relates to an oxygen indicator characterized by adding an ultraviolet absorber to an oxygen indicator comprising an agent and water or alcohol.

The invention according to claim 2 relates to the oxygen indicator according to claim 1, wherein the redox dye comprises methylene blue, the reducing agent comprises ascorbic acid, and the ultraviolet absorber comprises a benzotriazole-based drug.

[0010] The invention of claim 3 relates to the oxygen indicator according to claims 1 or 2, wherein the amount of the ultraviolet absorber added is from 100 ppm to 10000 ppm.

[0011]

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 or a salt 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.

As the ultraviolet absorber, besides benzotriazole drugs, triazine drugs, anilide oxalate drugs, benzophenone drugs, zinc oxide and the like can be used. When these drugs are used in combination, a synergistic effect is expected.

Further, the concentration of the ultraviolet absorber is 100 p.
pm or less, the effect is not sufficiently exhibited.
If it is 10,000 ppm or more, not only the effect reaches saturation, but also the discoloration of the redox dye is inhibited, and its detection function is inhibited.

Further, 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 or the like, or mixed with ink. It is.

In the oxygen indicator according to the present invention, the ultraviolet absorber absorbs ultraviolet energy and converts it into harmless heat energy, thereby preventing the oxidation-reduction dye from being deteriorated due to oxidation or decomposition, and has a long-term oxygen detection function. It is what keeps it.

[0018]

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, and 20.086 parts by weight of water. Screw (α,
α-Dimethylbenzyl) phenyl] -2H-benzotriazole was added so as to have a final concentration of 1000 ppm, and the mixture was tableted.

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] Sunlight was exposed to the oxygen indicator under aerobic conditions, and discoloration was observed.

[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, sealed, exposed to sunlight in an oxygen-free state, and observed for discoloration. Table 1 shows the results of Experiment 1.

[0023]

[Table 1]

When released from anoxic to aerobic, the color of the Examples and Comparative Examples quickly changed from white to blue within 5 minutes. Table 2 shows the results of Experiment 2.

[0025]

[Table 2]

Table 3 shows the results of Experiment 3.

[0027]

[Table 3]

From the results of Experiment 1, it was shown that the oxygen indicator of the present invention detects oxygen immediately after being released from the anoxic state to the aerobic state and changes its color. Also, from Experiment 2, when light was irradiated under an aerobic condition, the oxygen indicator of the comparative example faded, but the indicator to which the ultraviolet agent was added did not change color. Further, from Experiment 3, when light was irradiated under oxygen-free conditions, the color of the Comparative Example was changed in each of the nitrogen substitution and the carbon dioxide substitution, whereas the Example remained white. The oxygen indicator of the comparative example showed that when exposed to sunlight in an aerobic state, the dye faded and the ability to detect the presence or absence of oxygen was 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, indicating that the oxygen indicator according to the present invention has light resistance. By adding an ultraviolet absorber, it was possible to eliminate the effect of ultraviolet rays on the oxygen indicator and to maintain its oxygen detection ability.

Further, in the above-described embodiment, a 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.

[0030]

The oxygen indicator of the present invention is light-resistant by adding an ultraviolet absorber 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. It can provide an oxygen indicator that imparts heat resistance and heat resistance and maintains oxygen detection ability for a long period of time.

Continuation of front page (72) Inventor Takashi Urata 1-5-1, Taito, Taito-ku, Tokyo Letterpress Printing Co., Ltd. F-term (reference) 2G042 AA01 BB09 CA10 CB01 DA08 EA20 FA05 FA13 FA20 FB02 FB05 GA04 2G054 AB10 CA08 CE01 CE10 EA06 GB04 GE05

Claims (3)

[Claims] An oxygen indicator characterized by adding an ultraviolet absorber to an oxygen indicator comprising at least a redox dye, an amount of a reducing agent capable of converting all of the dye into a reduced form, and water or alcohol. 2. The oxygen indicator according to claim 1, wherein the redox dye is methylene blue, the reducing agent is ascorbic acid, and the ultraviolet absorber is a benzotriazole-based drug. 3. The method according to claim 1, wherein the concentration of the ultraviolet absorber is from 100 ppm to 10000 ppm.
The described oxygen indicator.