JP2007147297A - Ink composition for oxygen indicator, oxygen indicator, and packaging material containing oxygen indicator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oxygen indicator constituted so as to realize either one or both of a state of keeping an indicator function even if a high-temperature sterilization treatment is applied and a state excellent in light fastness and hard to cause fading. <P>SOLUTION: The ink composition for the oxygen indicator, which employs oxidation-reduction coloring matter and a natural oxidation inhibiting agent being a reducing agent and having heat resistance, is applied to or printed on a support to constitute the oxygen indicator. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a technique of an oxygen indicator for determining a deoxygenation state by an oxygen absorbent.

  Oxygen is known to oxidize foods and pharmaceuticals due to its high reactivity and to denature and degrade the active ingredients of products. For this reason, many foods and pharmaceuticals prevent oxidation by coexisting oxygen absorbers in the package. At that time, oxygen entry due to the ability of the oxygen absorber, pinholes in the package, poor sealing, etc. In order to detect this, an oxygen indicator is put into the package at the same time.

  Currently, several types of oxygen indicators are available on the market, with different combinations of redox dyes, reducing agents, binder resins, etc. Many oxygen indicators make use of the property that the redox dye exhibits different colors between the reduced and oxidized types. In particular, there are many that use methylene blue, and the oxygen indicator using methylene blue exhibits a reduced type, that is, colorless by the action of a reducing agent under deoxygenation, and is oxidized by oxygen in the atmosphere and exhibits blue.

  In addition to tablets, the oxygen indicator has been developed in liquid, ink, sheet, and paper types, as well as those integrated with oxygen absorbers and those integrated with packaging materials. Labor saving and easy detection discrimination are being made.

  Any reducing agent used for such an oxygen indicator can be used as long as the dye can be maintained in a reduced state. However, a strong reducing agent such as a metal hydride changes the color of the dye even in the atmosphere, or This is not preferable because of problems such as poor color development. In consideration of such a viewpoint and safety and health, most of the reducing agents used in oxygen indicators currently on the market use reducing sugars.

  On the other hand, in a packaging material provided with an indicator function, the contents to be filled are mostly subjected to a sterilization process, and are often subjected to high-temperature sterilization treatment such as boil and retort.

  However, it is clear that generally used reducing agents such as glucose and ascorbic acid do not have heat resistance, and therefore, when subjected to high-temperature sterilization treatment, they cannot be decomposed to maintain the indicator function. .

  Furthermore, one of the problems when using a dye such as methylene blue as the redox dye is that it is inferior in light resistance and easily fades during storage. For these reasons, it has been difficult to maintain the indicator function for a long time.

By the way, as a prior art using a rosemary extract as a component in an ink, there is one that improves light resistance for the purpose of preventing fading of a dye (for example, see Patent Document 1). However, there is no prior art used as a reducing agent in the oxygen indicator ink composition.
JP 2002-138225 A

  The present invention has been made in view of such background art, and either one of the indicator function is maintained even after high-temperature sterilization treatment, or it is excellent in light resistance and hardly discolored during storage, or It is an object to provide an oxygen indicator that achieves both.

  In order to achieve the above object in the present invention, first, the invention of claim 1 is an ink composition for an oxygen indicator characterized by using a redox dye and a natural antioxidant as a reducing agent. is there.

  The invention of claim 2 is the oxygen indicator ink composition according to claim 1, wherein the reducing agent is a natural antioxidant having heat resistance.

  In the invention of claim 3, the reducing agent is a rosemary extract. The ink composition for an oxygen indicator according to claim 1 or claim 2, wherein the reducing agent is a rosemary extract.

  Moreover, in invention of Claim 4, the said reducing agent is a rosemary extract, Comprising: The phenol carboxylic acid and luteolin are contained in the component, The any one of Claims 1-3 characterized by the above-mentioned. Ink composition for oxygen indicator.

  Moreover, in invention of Claim 5, a reducing agent acts at the time of a high temperature sterilization process, and the color tone of a redox dye changes from an oxidation color to a reduction color, It is any one of Claims 1-4 characterized by the above-mentioned. This is an ink composition for an oxygen indicator.

  Moreover, in invention of Claim 6, it was set as the oxygen indicator characterized by being obtained by apply | coating or printing on the support body the ink composition for oxygen indicators of any one of Claims 1-5. Is.

  According to a seventh aspect of the present invention, there is provided a packaging material containing an oxygen indicator according to the sixth aspect, wherein the support is separate from the exterior body forming the packaging body.

  According to an eighth aspect of the present invention, there is provided a packaging material containing an oxygen indicator according to the sixth aspect, wherein the support is an exterior body that forms a packaging body.

  According to the invention of claim 1, since a natural antioxidant is used as the reducing agent of the ink composition for the oxygen indicator, the oxygen indicator is prevented from fading of the oxidation-reduction dye, has excellent light resistance, and does not easily fade during storage. Can be provided. Natural antioxidants also have many substances that have been used as food additives for a long time, and can ensure the safety and hygiene required in the fields of food and medical drugs.

  According to invention of Claim 2, since the natural antioxidant which has heat resistance is used for the reducing agent of the ink composition for oxygen indicators, an indicator function can be maintained even after high temperature sterilization treatment.

According to the invention of claim 3, among the natural antioxidants such as sugars and sugar alcohols, amino acids, beans and cereals, there are many rosemary extracts obtained by hydrous alcohol extraction from Lamiaceae spices among the components. It can be expected to have an anti-fading effect of pigments. As a result, when methylene blue or the like that easily fades is used as the redox dye, the effect is remarkable.

  According to the invention of claim 4, among the active ingredients contained in the rosemary extract, in addition to phenolcarboxylic acid such as rosmarinic acid, luteolins are included as a synergist that dramatically enhances the antioxidant ability by a synergistic effect. This is very important. Thereby, even when the indicator is exposed to visible light or ultraviolet light, the indicator function can be maintained for a long time.

  According to the invention of claim 5, the reducing agent acts only after the high temperature sterilization treatment is performed on the ink composition for oxygen indicator of the present invention. Therefore, it can be assured that the package with the indicator function is reliably sterilized at high temperature and the package is maintained at zero oxygen concentration.

  According to the invention of claim 6, an oxygen indicator that realizes one or both of maintaining an indicator function even when subjected to a high temperature sterilization process, or being excellent in light resistance and difficult to fade during storage. Can be provided.

  According to the seventh and eighth aspects of the invention, does the packaging material containing the support coated or printed with the oxygen indicator ink composition of the present invention maintain the indicator function even when subjected to high-temperature sterilization treatment? In addition, it is possible to easily detect oxygen inside the package by either one or both of being excellent in light resistance and not easily fading during storage.

  The best mode for carrying out the present invention will be described below.

  The ink composition for an oxygen indicator of the present invention comprises at least a redox dye, a natural antioxidant having heat resistance as a reducing agent, a binder resin, and a solvent. The natural antioxidant having antioxidant ability can be expected not only to serve as a reducing agent but also to prevent the redox dye from fading. The oxygen indicator obtained by coating or printing the ink composition for oxygen indicator of the present invention on a support is stable when stored at room temperature, and the color tone is oxidized only after high-temperature sterilization treatment under deoxygenation. Changes to a reduced color. In addition, when the natural antioxidant exhibits the anti-fading effect of the redox dye, the expiration date of the oxygen indicator can be guaranteed over a long period of time.

  The redox dye used in the present invention is not particularly limited as long as it is a dye that exhibits different colors in an oxidized state and a reduced state, and any known dye can be used. Specifically, in addition to methylene blue, new methylene blue, neutral red, indigo carmine, indigo sulfonic acid potassium salt, safranin T, phenosafranine, capri blue, nile blue, diphenylamine, diphenylamine sulfonic acid, xylene cyanol, nitrodiphenylamine, ferroin, Nitroferroin, N-phenylanthranilic acid and the like can be used. In particular, when a dye having inferior light resistance is used, a great effect of preventing fading by a natural antioxidant can be expected.

As the reducing agent used in the present invention, any natural antioxidant that exhibits a reducing action when subjected to high-temperature sterilization treatment can be used. This is not preferable because it has problems such as being unable to maintain the reduced color. Specifically preferred as such a reducing agent are, besides rosemary extract, polyphenols such as tocopherol, quercetin and anthocyanin, tea catechin, gallic acid derivatives, amino acids such as caffeic acid, ferulic acid, glutathione, β-carotene and the like Carotenoids such as lycopene. It is very important to select a combination of a redox dye and a reducing agent, and it is necessary to consider the heat treatment temperature in the sterilization process. Moreover, it is preferable that the usage-amount is 1-100 weight part of said reducing agents with respect to 1 weight part of said oxidation-reduction pigment | dyes.

  The binder resin is used for fixing the redox dye, the reducing agent, and the solvent on the support. Specific examples of binder resins suitable for ink production include cellulose derivatives such as ethyl cellulose, hydroxylethyl cellulose, and cellulose acetate, butyral resins, acetal resins, polyester resins having a hydrophilic group introduced, acrylic resins, and urethane-ureas. Examples thereof include resins and urethane resins. In particular, in consideration of the solubility of the redox dye and high temperature sterilization treatment such as boiling and retort, it is preferable to use an aqueous resin having heat resistance.

  The binder resin is used by being dissolved or dispersed in an organic solvent typified by toluene, xylene, methyl ethyl ketone or ethyl acetate, or an aqueous solvent typified by water, methanol, ethanol or isopropyl alcohol. These solvents may be used alone or in combination with a plurality of solvents.

  In the ink composition for an oxygen indicator of the present invention, a surfactant, a dispersant, an antifoaming agent, and a coloring agent may be added separately in addition to the redox dye as necessary. By adding these into the ink, the stability, quick drying property, and visibility of the ink can be improved. The oxygen indicator ink composition may be adjusted to a two-component type. That is, the storage stability of the ink can be improved by mixing and using at least the liquid A composed of a pigment and a binder resin and the liquid B composed of a reducing agent and a binder resin. Furthermore, an anchor coat layer and an overcoat layer can be provided above and below the ink composition for the purpose of improving the adhesion strength with the support and preventing further discoloration of the pigment. The coating agent that can be used is not particularly limited as long as it is permeable to oxygen and has good adhesion to the support, or contains an ultraviolet absorbing material and does not interfere with the color development of the oxygen indicator. Can also be used.

  As described above, the above ink composition is applied to a support to produce an oxygen indicator. Printing and coating methods are used for application. As a printing method, a relief printing method, an intaglio printing method, an offset printing method, a screen printing method, and the like can be used. As a coating method, roll coating, spray coating, dip coating, solid coating, and the like are used.

  It is preferable that the support does not react with the ink composition and does not inhibit the coloration of the reagent. Specifically, paper, synthetic paper, non-woven fabric, or synthetic resin film is used. The support is separate from the outer packaging made of a gas barrier packaging material that wraps the contents of food, pharmaceuticals, etc., and the indicator that has the ink composition applied to the support at the same time as the packaging is packaged in the outer packaging. Encapsulate.

Alternatively, the outer package itself for packaging the contents or a part thereof may be used as a support, the ink composition may be applied to the inner surface of the outer package, and the outer package may be used as an indicator. It is necessary to provide an oxygen barrier layer on the outside of the oxygen indicator ink composition for the purpose of preventing oxygen from entering. These materials include polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyamide resins such as polyamide 6 and polyamide 6-polyamide 66 copolymers, polyamide resins represented by aromatic polyamides such as MXD6, polyacrylonitrile resins, and polyvinyl alcohol resins. , Ethylene-vinyl alcohol copolymer resin, thermoplastic resin layer selected from polyvinylidene chloride resin, metal foil layer such as aluminum foil, PVD vapor deposition method such as aluminum, silica and alumina, or organosilane such as hexamethylenedisiloxane And a vapor-deposited thermoplastic resin layer obtained by a CVD vapor deposition method using acetylene gas or other carbon gas sources.

Examples of the present invention and comparative examples thereof will be specifically described below. The present invention is not limited to this embodiment.
<Example 1>
The ink composition for oxygen indicator of Example 1 is
Methylene blue ... 1.8 parts by weight,
Rosemary extract ... 7.2 parts by weight,
Aqueous acrylic resin ... 5.0 parts by weight,
Methanol 43.0 parts by weight,
Water ... 43.0 parts by weight,
Consists of.

For the rosemary extract, RM-21A base manufactured by Mitsubishi Chemical Foods Corporation was used. The ink composition was finely dispersed with a paint conditioner or the like to obtain an ink composition. This was printed twice with a 200 L, 30 μm gravure plate on a PET 12 μm corona-treated surface and dried at room temperature for 12 hours. A urethane-based two-component curable adhesive was used for the printed matter, and an alumina vapor-deposited film and a sealant film were laminated on and under the PET by a dry laminating method, respectively, to obtain a packaging material containing the oxygen indicator of the present invention. This packaging material was made into a bag, and after an oxygen absorbent was added, it was sealed with nitrogen.
<Comparative Example 1>
The ink composition for oxygen indicator of Comparative Example 1 is
Methylene blue ... 1.8 parts by weight,
Ascorbic acid ... 7.2 parts by weight,
Aqueous acrylic resin ... 5.0 parts by weight,
Methanol 43.0 parts by weight,
Water ... 43.0 parts by weight,
Consists of.

A packaging material for evaluation was obtained in the same manner as in Example 1 except for the ink composition.
<Comparative example 2>
The ink composition for oxygen indicator of Comparative Example 2 is
Methylene blue ... 1.8 parts by weight,
Triethanolamine, 7.2 parts by weight,
Aqueous acrylic resin ... 5.0 parts by weight,
Methanol 43.0 parts by weight,
Water ... 43.0 parts by weight,
Consists of.

A packaging material for evaluation was obtained in the same manner as in Example 1 except for the ink composition.
[Test 1]
A retort treatment at 121 ° C. for 30 minutes was performed, and the color tone of the oxygen indicators of the examples and comparative examples was observed. Moreover, the evaluation sample made into oxidation color and reduction color was preserve | saved over a long period of time, and the change of the color tone was observed. The results are shown in Table 1.

［試験２］
得られた酸素インジケーターの耐光性を、光安定性試験機を用いて評価した。光照射条件は、１２０００００Ｌｕｘ、温度：２５℃、湿度：６５％である。結果を表２に示す。

[Test 2]
The light resistance of the obtained oxygen indicator was evaluated using a light stability tester. The light irradiation conditions are 1200000 Lux, temperature: 25 ° C., humidity: 65%. The results are shown in Table 2.

［試験１］の表１より、長期保存試験において、比較例１は、熱処理による還元剤の失活により酸素濃度ゼロの場合も還元色を維持できない。

From Table 1 of [Test 1], in the long-term storage test, Comparative Example 1 cannot maintain a reduced color even when the oxygen concentration is zero due to deactivation of the reducing agent by heat treatment.

  From Table 1 of [Test 1], in the long-term storage test and color development stability, the color of Comparative Example 2 partially changes to a reduced color even under aerobic conditions where the oxidized color should be maintained.

  From Table 2 of [Test 2], in the light resistance test, Example 1 has a smaller ΔE value before and after light irradiation than Comparative Examples 1 and 2, and fading due to light is suppressed.

Claims (8)

  An ink composition for an oxygen indicator, characterized by using a redox dye and a natural antioxidant as a reducing agent.   2. The oxygen indicator ink composition according to claim 1, wherein the reducing agent is a natural antioxidant having heat resistance.   3. The oxygen indicator ink composition according to claim 1, wherein the reducing agent is a rosemary extract.   The ink composition for an oxygen indicator according to any one of claims 1 to 3, wherein the reducing agent is a rosemary extract and contains phenol carboxylic acid and luteolins as its components.   The ink composition for an oxygen indicator according to any one of claims 1 to 4, wherein the reducing agent acts during high-temperature sterilization, and the color tone of the redox dye changes from an oxidized color to a reduced color.   An oxygen indicator obtained by applying or printing the ink composition for an oxygen indicator according to any one of claims 1 to 5 on a support.   The packaging material containing an oxygen indicator according to claim 6, wherein the support is separate from the exterior body forming the packaging body.   The packaging material containing an oxygen indicator according to claim 6, wherein the support is an exterior body that forms a packaging body.