JPH10307131A - Coloring matter for checking oxygen permeation part, composition for checking oxygen permeation part using it, and method for checking oxygen permeation part of packaging container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and accurately check and evaluate an oxygen permeation part by using indigoid coloring matter for exposing specific absorption wavelength and color in an oxidized state and a reduced state. SOLUTION: An indigoid coloring matter to be used has an absorption wavelength of in a range of 500-700 nm and exposes blue violet or blue and has an absorption wavelength of 400 nm or less in a reduced state and is colorless or exposes light yellow with an absorption wavelength of 400 nm or less in a reduced state. With a composition 2 for checking an oxidation reduction type oxygen permeation part, the change in a coloring matter with time in the composition 2 is observed by leaving a packaging container 1 to be tested being filled and sealed in an atmosphere containing oxygen and hardening the composition 2 in the packaging container 1. Then, for example, when a part where a pin hole 4 is generated and a part Q where a crack 5 exists are present, the coloring matter in the composition 2 at the part of the parts P and Q changes its color from colorless and light yellow to blue violet or blue, thus verifying and specifying the parts P and Q where a pin hole 4 or a crack 5 exists in the packaging container 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dye for confirming an oxygen-permeable portion, a composition for confirming an oxygen-permeable portion using the same, and a method for confirming an oxygen-permeable portion of a packaging container. A simple and accurate confirmation, oxygen permeation site confirmation dye that can be evaluated,
The present invention relates to a composition for confirming an oxygen-permeable portion using the same and a method for confirming an oxygen-permeable portion of a packaging container.

[0002]

2. Description of the Related Art Generally, a packaging container for filling and packaging not only foods and drinks but also products that dislike oxygen and the like must have a sufficient gas barrier property against oxygen gas and the like. For this reason, various packaging materials have been developed and proposed, and packaging containers of various forms have been developed,
Proposed. By the way, in general, it is natural that the packaging material itself constituting the packaging container is inferior in gas barrier property against oxygen gas or the like.For example, when the gas barrier layer is deteriorated in the process of manufacturing the packaging container,
Alternatively, when pinholes or cracks occur in the gas barrier layer, a problem such as a partial decrease in oxygen gas barrier properties of the packaging container occurs. In the case where the packaging container is a molded container made of, for example, a plastic bottle or the like, the thickness of the container itself changes in the molding process, or a pinhole occurs, and further, the cap portion or the joint portion is deformed. This causes problems such as a decrease in oxygen gas barrier properties. Furthermore, even in a closed packaging container using a metal foil such as an aluminum foil, pinholes or cracks occur in the aluminum foil due to bending or the like,
This causes a problem of a decrease in the oxygen gas barrier property. Regardless of the packaging container made of any material, if the cap or the joint is misaligned or distorted, there is a problem in the tightness of the packaging container, and oxygen from the portion into the packaging container. It is inevitable that the gas permeates and the gas barrier property decreases. By the way, to reduce the gas barrier property of oxygen gas or the like, a method of measuring the oxygen permeability of the entire packaging container as a numerical value defined in the JIS K-7126B method is generally used. Although it is possible to judge the decrease in the oxygen gas barrier property of itself, it is extremely difficult to confirm a portion where the oxygen gas barrier property has decreased and to specify the portion. Thus,
Conventionally, various methods have been developed and proposed as a method for confirming or evaluating the oxygen-permeable portion of a packaging container. One of them is a simple method, a closed container using leucomethylene ble-dye. (See Japanese Patent Publication No. 57-46493).

[0003]

However, in the above-mentioned detection method, it is difficult to adjust the test time, and when the oxygen permeability of the packaging container is large, the reaction of the dye proceeds too much, and In some cases, it may be difficult to confirm and identify the part where the gas barrier property is deteriorated, and when evaluating a packaging container having a small oxygen permeability, a long test time must be taken, and the result must be obtained in a short time. This is an inappropriate method if you want it. Furthermore, in the above-mentioned detection method, it is necessary to adjust the pH of the dye-containing solution to 8 or more in order to reliably detect the oxygen permeable site. Due to the ability, it becomes difficult to confirm discoloration apparently even if the oxidation of the dye proceeds, and even if the pH is too low, the dye discolors before filling the dye-containing solution for the same reason,
It is difficult to confirm the discoloration of the packaging container due to oxygen permeation, and it is difficult to confirm and identify the site.
Accordingly, the present invention provides a simple and accurate oxygen-permeation site confirming dye that can be used to confirm and evaluate an oxygen-permeable portion of a packaging container, a composition for confirming an oxygen-permeable portion and a packaging container using the same. An object of the present invention is to provide a method for confirming an oxygen permeable site.

[0004]

As a result of various studies to solve the above problems, the present inventor has found that a dye which is oxidized by oxygen and changes color dramatically in order to visualize an oxygen permeable site. More specifically, as the dye that is oxidized by oxygen and changes color dramatically, the value is lower than the oxidation-reduction potential of oxygen, and the state before being oxidized by oxygen and oxygen In the state oxidized by the above, a change occurs in the absorption of visible light, which is defined as a dye having a large difference in color change, a dye suitable for this definition was searched, and various examinations were conducted. An indigoid-based dye having an absorption wavelength in the range of 500 to 700 nm in the state and exhibiting a blue-violet or blue color and an absorption wavelength in the reduced state of 400 nm or less and exhibiting a colorless or pale yellow color. It has been found that it is a dye that meets the above object.

The inventors of the present invention have found that in the above-mentioned oxidized state, the absorption wavelength is in the range of 500 to 700 nm, exhibiting a bluish purple or blue color, and in the reduced state, the absorption wavelength is about 40.
A colorless or pale yellow indigo-based dye having a size of 0 nm or less is dissolved or dispersed in a gelling substance to prepare the indigo-based dye-containing composition, and then the composition is placed in a packaging container to be tested. After filling and sealing, the packaging container under test filled with the composition is allowed to stand in an oxygen-containing atmosphere, and the composition in the container under test is solidified to change the color of the dye in the composition over time. By observing and evaluating the oxygen-permeable portion of the packaging container, it was found that the oxygen-permeable portion of the packaging container could be confirmed and evaluated extremely easily and reliably, and completed the present invention. It was done.

That is, according to the present invention, in the oxidized state, the absorption wavelength is in the range of 500 to 700 nm, exhibiting bluish purple or blue, and in the reduced state, the absorption wavelength is 400 nm.
The present invention relates to a redox type oxygen permeation site confirming dye which is colorless or pale yellow, and relates to an oxygen permeation site confirmation composition using the same and a method for confirming an oxygen permeation site of a packaging container.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below. First, in the present invention, the absorption wavelength is in the range of 500 to 700 nm in the oxidized state and exhibits a blue-violet or blue color, and the absorption wavelength is 40 in the reduced state.
The redox oxygen-permeation site confirming dye having a colorless or pale yellow color of 0 nm or less is, as described above, a dye that is oxidized by oxygen and changes color dramatically,
A dye that has a lower value than the oxidation-reduction potential of oxygen and changes the absorption of visible light between the state before oxidation by oxygen and the state oxidized by oxygen, and has a large difference in color change. Is used. Specifically, in the present invention, an indigoid-based dye can be used as the dye for confirming the oxidation-reduction type oxygen-permeable portion. For example, indigo (Indigoble-2B, Indigobat I.II, Indigotin), indigocarmine (Indigodisulfone-
G), indigo white, indigo trisulfonate, indigo tetrasulfonate, indigozole O, indigo shiba R, various indigo dyes such as 6.6-dibromoindigo extracted from shellfish, or And thioindigo dyes, indicane (indico red) dyes and the like. Thus,
The above-mentioned indigo dye is a so-called indigo dye,
It exhibits a blue or bluish violet color, and the thioindigo-based dyes described above, among indigo dyes, exhibit red, purple, and brownish colors, and are used as redox indicators. Is what is being done.

In the present invention, the state before the dye is oxidized by oxygen means a state in which the dye is reduced to exhibit a colorless or pale yellow color,
Thus, such a thing is obtained by making a reducing agent act on an oxidized dye. In the above, as the reducing agent, those that reduce the dye can be used, and the condition is that the oxidation-reduction potential is lower than that of the target dye, for example, lower oxide, CO,
SO ₂ , Na (H ₂ PO ₂ ), Na ₂ S ₂ O ₃ , Na ₂
Lower oxyacid salts such as S ₂ O ₄ , Li, Na, Ca, Mg,
Zn, Fe, Fe (II), Sn (II), Ti (III),
Metals with high ionization tendency such as Cr (II) or amalgams thereof, AlH [(CH ₃ ) ₂ CHCH ₂ ], L
iAlH _4, NaBH ₄ hydride such as, hydrazine, diimide, formic acid, aldehydes, saccharides, can be used L- ascorbic acid and the like.

In the present invention, it is necessary to gel and immobilize the above-mentioned dye-containing solution in order to identify the oxygen-permeable portion of the packaging container. Examples of the water-soluble gelling agent include water-soluble resins such as agar, gelatin, polyacrylamide resins and poly (meth) acrylic resins;
One or more substances such as protein, denatured protein, thickening polysaccharides such as mannan or carrageenan, proteins such as egg white, which solidify by heating, and the like can be used.

In the present invention, the composition for confirming an oxygen-permeable site using the above-mentioned dye may be, for example, one or more of the above-mentioned dyes, and the reduction of the above-mentioned dyes. One or more agents and other additives are optionally added and dissolved or finely dispersed in a solution such as water to prepare a dye solution. On the other hand, one of the above-mentioned gelling agents Or more, and further, optionally other additives, dissolved or finely dispersed in a solution such as water to prepare a gelling active substance solution, and then, both solutions were mixed, The composition for confirming the oxygen permeation site according to the present invention can be prepared by stirring and mixing. The above example is an example. Needless to say, in the present invention, each component is prepared, and each of them is added to a solution such as water at a time, thoroughly mixed and stirred, and the oxygen according to the present invention is obtained. The composition for confirming the permeation site can also be adjusted.

In the above composition for confirming an oxygen permeable site, the compounding ratio of the gelling substance and the dye is, for example, 20 to 30 g / l for the former and 0.8 to 30 g / l for the latter.
About 1.2 g / l is preferable.

Next, the method of confirming the oxygen permeable portion of the packaging container in the present invention will be described. As shown in the schematic plan views of FIGS. The composition 2 for confirming the oxidation-reduction type oxygen-permeable portion containing the adjusted gelling substance, the dye for confirming the oxidation-reduction-type oxygen-permeable portion, and other additives is filled and sealed (see FIG. 1). In the figure, reference numeral 3 denotes a sealing portion for sealing the packaging container. Next, in the present invention, as shown in FIG. 2, the packaging container under test 1 filled and sealed with the composition 2 as described above is left in an oxygen-containing atmosphere.
The composition 2 in the composition is solidified and the color change of the dye in the composition 2 with time is observed. Thus, for example, a portion P where the pinhole 4 is generated has a composition at the portion P. The color of the pigment in the product 2 changes from colorless or pale yellow to bluish purple or blue, and at the location Q where the crack 5 exists, the pigment in the composition 2 at the location Q is the same as described above. The color changes from colorless or pale yellow to bluish purple or blue, whereby the location PQ where the pinhole 4 or the crack 5 exists in the packaging container 1 can be confirmed and specified, The oxygen permeation site can be confirmed. In the figure, 1, 2, and 3
This has the same meaning as described above.

In the method for confirming the oxygen-permeable portion of a packaging container according to the present invention as described above, for example, the pH value of the composition is adjusted to adjust the test time, or the concentration of the reducing agent in the composition is adjusted. To adjust the test time,
Further, adjusting the test time by using dyes having different oxidation rates as dyes can be arbitrarily taken as needed.

[0014] As described above, the method for confirming the oxygen-permeable portion of a packaging container according to the present invention uses a portion of a packaging container having a gas barrier property such as oxygen gas where oxygen permeability is reduced or a portion where oxygen permeability is deteriorated. And the like, using a dye that changes its color from colorless or pale yellow to bluish purple or blue by being oxidized by oxygen entering from that part, and visualizing and confirming that part.In addition, the concentration of the reducing agent, the dye This is a method in which the test period can be suppressed by adjusting the pH or the like of the contained solution. Furthermore, the method for confirming the oxygen-permeable portion of a packaging container according to the present invention enables the evaluation of a large number of packaging containers at one time, and the operation is easy to adjust the dye-containing solution, Further, the test time can be adjusted by adjusting the solution.

In the present invention, the packaging containers to be tested may be various packaging containers.
It can be applied to plastic soft packaging bags, plastic molded containers, glass containers, and the like.

[0016]

Next, the present invention will be described more specifically with reference to examples. Example 1 A 20 g / l agar solution was prepared.
And kept warm as it is. Thereafter, 0.28 g of indigo carmine was added to the agar solution at 80 ° C., and the mixture was stirred sufficiently. The indigo carmine was dissolved in the agar solution, and the dye-containing solution was dissolved. It was adjusted. Next, 1.2 g of sodium hydrosulfite was added to the dye-containing solution immediately before filling into the target test packaging container, and a composition was prepared to eliminate the blue color and fill the test packaging container.

Example 2 In the above Example 1, 0.49 g of indigo trisulfonate was used in place of 0.28 g of the indigo carmine dye. Thus, a composition to be filled in the test packaging container was prepared.

Example 3 In the above Example 1, 0.41 g of indigotetrasulfonate was used in place of 0.28 g of the indigo carmine dye, and the other conditions were the same as in the above Example 1. Thus, a composition to be filled in the test packaging container was prepared.

Comparative Example 1 In the above Example 1, 0.2 g of methylene blue was used in place of 0.28 g of the indigo carmine dye, except that the test packaging container was the same as Example 1 above. A composition to be filled was prepared.

EXPERIMENTAL EXAMPLE A three-way seal type soft packaging bag of 10 cm × 10 cm size using a laminated material comprising a biaxially stretched polyethylene terephthalate film having a thickness of 12 μm and a low density polyethylene film having a thickness of 40 μm. Was manufactured. Next, the compositions prepared in Examples 1 to 3 and Comparative Example 1 were filled in the soft packaging bag, and then one of the remaining openings was sealed to prevent air bubbles from entering. Each was sealed to produce a sealed packaged product. Next, each of the sealed packaged products produced above was quenched in cold water to solidify the agar in the sealed packaged product, and then stored in a thermostat at 37 ° C. to change the color change of the dye in the agar with time. Was observed and evaluated. The results are shown in Table 1 below.
Shown in

[0021]

[Table 1]

From the above results, those of Examples 1 to 3
It was suitable for confirming the oxygen permeation part of the packaging container. In the above Examples 1 to 3 and Comparative Example 1, the rate of oxidative coloring of the dye was increased in the order of Example 1 <Example 3 <Comparative Example 1 <Example 2; It was found that the phone developed the color fastest. The above speed difference could be changed to some extent by adjusting the amount of the reducing agent.However, if the amount was reduced too much, there was a limit because a complete reduced dye could not be obtained. By choosing by speed, the test period could be shortened or extended. The oxidation rate depends on the pH of the solution.
When the pH is increased, the oxidation rate is slowed down, and when the pH is decreased, the oxidation rate is increased.However, the pH is too high or too low to behave as a pH indicator. It was difficult to achieve the purpose of this test. Further, depending on the degree of oxygen permeability of the laminate, the test period could be shortened or lengthened by properly using the dye oxidation rate. Indigo dyes vary in color tone depending on the type, indigo tetrasulfonate changes from yellow to black, indigo carmine changes from yellow to blue, and indigo trisulfonate changes in color.
It was found that the color changed from yellow to green.

[0023]

As is apparent from the above description, the present invention focuses on using a dye that is oxidized by oxygen and changes color dramatically in order to visualize an oxygen-permeable portion.
More specifically, the dye that is oxidized by oxygen and changes color dramatically has a value lower than the oxidation-reduction potential of oxygen, and is in a state before being oxidized by oxygen and in a state oxidized by oxygen. It is defined as a dye that causes a change in the absorption of visible light, and is defined as a dye having a large difference in the color change, and a dye that meets this definition is searched for and variously examined. 700
It has been found that an indigoid-based dye exhibiting a bluish purple or blue color within the range of nm and exhibiting an absorption wavelength of 400 nm or less in a reduced state and being colorless or pale yellow is a dye suitable for the above purpose. . Thus, according to the present invention, the absorption wavelength is 500 to 70 in the above oxidation state.
The indigoid-based dye which exhibits a bluish purple or blue color within the range of 0 nm and has an absorption wavelength of 400 nm or less in the reduced state and exhibits a colorless or pale yellow color is dissolved or dispersed in a gelling substance to contain the indigoid-based dye. The composition is prepared, and then the composition is filled and sealed in a packaging container to be tested, and then the packaging container to be sealed and filled with the composition is left in an oxygen-containing atmosphere, and the test is performed. By solidifying the composition in the container and observing the color change over time of the dye in the composition, confirming the oxygen-permeable portion of the packaging container and evaluating it, the oxygen-permeable portion of the packaging container was extremely easily,
In addition, it can be surely confirmed and evaluated.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a configuration of a test packaging container in a method for confirming an oxygen-permeable portion of a packaging container according to the present invention.

FIG. 2 is a schematic plan view showing a configuration of a test packaging container in the method for confirming an oxygen-permeable portion of a packaging container according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Packaging container to be tested 2 Composition for confirming redox oxygen permeation site 3 Seal portion 4 Pinhole 5 Crack P Location where pinhole 4 is generated Q Location where crack 5 is present

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // C09B 7/00 C09B 7/00

Claims (10)

[Claims] An absorption wavelength of 500 to 7 in an oxidized state.
A redox-type oxygen-permeation site-confirming dye characterized by being blue-violet or blue in the range of 00 nm and exhibiting an absorption wavelength of 400 nm or less and being colorless or pale yellow in a reduced state. 2. The oxidation-reduction type oxygen permeation site confirming dye according to claim 1, wherein the dye comprises an indigoid dye. 3. The gelling agent has an absorption wavelength in the range of 500 to 700 nm in an oxidized state and exhibits a blue-violet or blue color, and has an absorption wavelength of 400 nm in a reduced state.
A composition for confirming an oxidation-reduction type oxygen-permeable portion, which is obtained by dissolving or dispersing a colorless or pale yellow colorant for confirming an oxidation-reduction-type oxygen-permeable portion. 4. The composition according to claim 3, wherein the dye comprises an indigo dye. 5. The gelling substance has an absorption wavelength in the range of 500 to 700 nm in an oxidized state and exhibits a blue-violet or blue color, and has an absorption wavelength of 400 nm in a reduced state.
The following composition is prepared by dissolving or dispersing a colorless or pale yellow colorant for confirming the oxidation-reduction type oxygen-permeable portion, which is present in the packaging container to be tested. After that, the packaging container under test filled with the composition is left to stand in an oxygen-containing atmosphere, and the composition in the packaging container under test is solidified to allow the dye in the composition to elapse over time. A method for confirming an oxygen-permeable portion of a packaging container, characterized by observing a color change. 6. The method according to claim 5, wherein the test time is adjusted by adjusting the pH value of the composition. 7. The test according to claim 5, wherein the test time is adjusted by adjusting the concentration of the reducing agent in the composition.
The method for confirming an oxygen-permeable portion of a packaging container described in (1). 8. The method according to claim 5, wherein the dye comprises an indigo-based dye. 9. The method according to claim 5, wherein a test time is adjusted by using a dye having a different oxidation rate as the dye. 10. The method according to claim 5, wherein the oxygen-containing atmosphere is an atmosphere in a constant temperature layer at a normal temperature or higher.
6. The method for confirming an oxygen-permeable portion of a packaging container according to 6, 7, 8 or 9.