JPH0352580B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an oxygen sensing agent, and more specifically, one or more compounds selected from the group consisting of phosphates and dehydrated condensates thereof (hereinafter referred to as phosphate compounds). The present invention relates to an oxygen detecting agent in the presence of water, which is composed of a redox dye and a redox dye. Oxygen detection agents allow the presence or absence of oxygen in a sealed atmosphere to be determined with the naked eye by a change in color tone, and the change in color tone is reversible in the presence and absence of oxygen. It has the great feature of being highly accurate. Conventionally, polarography, galvanic cell type analyzers, stabilized zirconia type analyzers, etc. have been used to detect oxygen, but all of them are large and expensive, and require a power source, so it is not easy to use. It can hardly be called a detection analysis method. In addition, recent trends include the development of various packaging methods such as vacuum packaging, gas replacement packaging using inert gases such as nitrogen and carbon dioxide, packaging using oxygen absorbers, and the development of gas barrier films for the purpose of preserving freshness in food packaging. Together with this, it is rapidly being used.
These various packaging methods were developed primarily for the purpose of removing oxygen from packaging containers or bags, and the foods that use these packaging methods are both inexpensive and available in large quantities, making them cheap and easy to use. There is a demand for the development of a method for detecting oxygen using a method based on the method. Currently, in order to meet these needs, liquid or solid oxygen detection agents are known, but they all contain redox dyes, alkaline compounds, and reducing agents as essential components. Glucose, hydrosulfite, glucose, dithionite used,
Ferrous salts, ascorbic acid, etc. all have strong reducing properties; for example, glucose can reduce ferric salts to metallic iron in the presence of sodium hydroxide, which is an alkaline compound. However, when these reducing agents are used as raw materials for oxygen sensing agents, they must be stored in an oxygen-free state to prevent oxidation.
Furthermore, even when prepared as an oxygen detecting agent, it must be stored in an anaerobic state without oxygen, which is one of the major drawbacks of this type of oxygen detecting agent. Therefore, the present inventors conducted intensive studies to find an oxygen detecting agent that is inexpensive, easy to handle, and does not require any effort when storing raw materials or storing the oxygen detecting agent. We have discovered a detection agent. That is, the present invention provides 1 selected from phosphate compounds.
This is an oxygen detection agent in the presence of moisture, consisting of more than one type of compound and a redox dye. Examples of the phosphate compound constituting the oxygen detector of the present invention include phosphoric acid in which the phosphorus atom in the salt exists in a pentavalent cation state, pyrophosphoric acid, trimetaphosphoric acid, which is a dehydrated condensate of the phosphoric acid, Examples include alkali metal salts and alkaline earth metal salts such as tetrametaphosphoric acid. Preferred examples include sodium salts, magnesium salts, calcium salts, etc. Particularly preferred specific examples include monobasic sodium phosphate, monobasic sodium phosphate, etc. Examples include sodium diphosphate, magnesium triphosphate, sodium pyrophosphate, magnesium pyrophosphate, and calcium pyrophosphate. Furthermore, hydrates of these phosphate compounds can also be used in the present invention. Further, the redox dye, which is another component constituting the oxygen detecting agent of the present invention, is a dye whose color tone varies depending on the oxidation state and the reduction state, such as methylene blue, new methylene blue, methylene green, and isenmethylene blue. , toluidine blue, safranin, Meldora blue, etc. In the present invention, the blending ratio of the phosphate compound and the redox dye is not particularly limited as long as the blended amount of the redox dye is an amount that exhibits the function as an oxygen detection agent. It is preferable that the amount of the redox dye is 0.001 to 13% by weight, more preferably 0.01 to 5% by weight, based on the total amount of the redox dye. If the amount of redox dye is less than 0.001% by weight, the resulting oxygen detecting agent will be less colored and it will be difficult to judge the change in color tone due to the presence or absence of oxygen.
Even if a larger amount is added, the degree of coloring does not increase, and
Since dyes are generally expensive, this also causes an economic loss, which is not preferable. The oxygen sensing agent of the present invention includes conventional redox dyes,
It is completely different from the combination of an alkaline compound and a reducing agent, and its constituent components are a phosphate compound and a redox dye, and both of the phosphate compounds do not have any reducing properties, and therefore, the present invention The mechanism of action of this oxygen sensing agent is completely different from that of conventional oxygen sensing agents. It is currently unclear why the composition of the present invention has the function as an oxygen detector, but phosphate compounds have been conventionally used as pH buffering agents, and This is presumed to be due to the atomic physical properties of phosphorus. Furthermore, the oxygen detecting agent of the present invention has a great advantage in that the above-mentioned phosphate compound, which is an essential component of the oxygen detecting agent of the present invention, is permitted to be used as a food additive and is safe. ing. Further, the oxygen detecting agent of the present invention exhibits its function at a very small oxygen concentration, that is, at an oxygen concentration of about 0.05% by volume. This is due to the fact that conventional oxygen detectors
Compared to the case where it works at around 0.2% by volume, it shows extremely high oxygen detection sensitivity, which is another major feature of the present invention. In order for the oxygen sensing agent of the present invention to perform its function, the presence of water is necessary. Therefore, for example, water may be added during the production of an oxygen detector, or an inert crystal water-containing compound that does not impair its function as an oxygen detector, such as sodium sulfate decahydrate or sodium carbonate decahydrate. etc. are added.
Furthermore, when packaging high-moisture foods, the partial pressure of water vapor inside the packaging container or bag increases, so even if water or a crystal water-containing compound is not specifically added to the oxygen detecting agent of the present invention, water vapor can be It becomes possible to replenish the supply of The amount of coexisting water in which the oxygen sensing agent according to the present invention effectively exhibits its function is preferably 0.1 parts by weight per 100 parts by weight of the total amount of the phosphate compound and redox dye.
Part by weight, more preferably 0.5 part by weight or more.
If the coexisting amount of water is less than this, the amount of phosphate compounds and redox pigments dissolved in water will be small, so
It does not fully demonstrate its functions. In addition, when water is added and blended during the production of the oxygen detector, the amount should be 50 parts by weight or less, more preferably 25 parts by weight or less per 100 parts by weight of the total amount of phosphate compound and redox dye. This is preferable, and this can prevent water from rising to the surface of the tablet when the oxygen sensing agent is molded, for example, compressed into a tablet. Addition of fillers, alkaline compounds, pigments, dyes, etc. that do not change color depending on the presence or absence of oxygen for the purpose of hue adjustment to the oxygen detecting agent of the present invention may also impair its function as an oxygen detecting agent. It is possible as long as you do not. Extending agents include silica, silica alumina, alumina, silica magnesia, zeolite, diatomaceous earth, silica gel, kaolin, talc and the like. In addition, the rate of change in color tone of the redox dye is adjusted,
Alternatively, alkaline compounds such as alkali metal or alkaline earth metal hydroxides, carbonates, hydrogen carbonates, silicates, etc. may be added to provide an oxygen detection function in a carbon dioxide atmosphere. Conventional oxygen detectors have a major drawback in that alkaline compounds in the detector, such as sodium hydroxide, react with carbon dioxide gas and do not function as oxygen detectors in a carbon dioxide atmosphere such as in carbon dioxide gas replacement packaging. was. However, the oxygen detecting agent of the present invention can be made to function as an oxygen detecting agent even in a carbon dioxide atmosphere by adding an alkaline compound such as a hydrogen carbonate, such as a sodium salt, a potassium salt, or a magnesium potassium salt. The preferred blending amounts of the extender and alkaline compound are 10 to 1000 parts by weight, respectively, based on 100 parts by weight of the total amount of the phosphate compound and redox dye. Further, when a hydrogen carbonate is blended for the purpose of detecting oxygen in the presence of carbon dioxide gas, a more preferable blending amount is 100 to 800 parts by weight. When producing the oxygen sensing agent of the present invention, there are no restrictions on the order of addition of the phosphate compound, redox dye, water, optionally added alkaline compound, filler, dye, etc. The oxygen detecting agent of the present invention can be used in the form of a powder obtained by simply mixing each component, or as a tablet formed by a tablet molding machine, etc., or can be used in any form such as an ink formed by using the oxygen detecting agent of the present invention as a pigment. It can also be used in any form. However, if it is in solid form, it must be packaged with a film with high oxygen permeability to prevent direct contact with the food to be packaged, or if it is made into ink, it must be printed on various types of film and then oxygenated. In terms of food hygiene and safety, it is preferable to laminate with a highly permeable film to prevent direct contact with food. As mentioned above, the oxygen detecting agent of the present invention is completely different from conventional types; the essential component, the phosphate compound, is safe and stable in the atmosphere, and therefore the obtained oxygen detecting agent is also stored in an anaerobic state. In addition, it is easy to handle even if it is applied in solid form or after being made into an ink, and it is suitable for vacuum packaging, gas displacement packaging, and packaging using oxygen absorbers used for packaging foods, pharmaceuticals, electronic materials, etc. The presence or absence of oxygen in a closed container can be easily determined, and the integrity of these various packages can be checked. In addition, the oxygen detecting agent of the present invention has a reversible change in color tone in the presence and absence of oxygen, and therefore can be used repeatedly.Also, since the oxygen detection agent has high oxygen detection sensitivity, it can be sealed by the above-mentioned packaging method. Damage to the container;
For example, the occurrence of pinholes due to mechanical damage during distribution, peeling of the sealing surface, etc. can also be determined. The present invention will be explained in more detail below by giving examples. Note that the oxygen detecting agent of the present invention is not limited to the examples shown below. Examples 1 to 10 Redox dyes, phosphates or dehydrated condensates thereof, and other additives listed in Table 1 were thoroughly mixed to obtain oxygen detector powder. This was placed under an atmosphere as shown in Table 1, and changes in the color tone of the oxygen detecting agent were observed. The results were as shown in Table 1. 【table】

Claims (1)

[Claims] 1. An oxygen-sensing agent in the presence of moisture, comprising one or more compounds selected from the group consisting of phosphates and dehydrated condensates thereof, and a redox dye.