JPH0317553A - Oxygen indicator label - Google Patents

Abstract

PURPOSE:To make it possible to fix an oxygen indicator easily inside a bag for packing and on the surface of a non-packed article, to make detection of oxygen acute and also to enable detection thereof from outside, by forming the oxygen indicator in the shape of a label. CONSTITUTION:A printing ink layer 2 constituted of oxygen indicator ink is provided on a sheet-shaped base 1 used in the field of printing of various paper, synthetic paper, a plastic film, a metal leaf, etc. A filler layer 3 is formed preferably for eliminating indentation of the surface of the sheet-shaped base 1 and infiltration with ink, and the printing ink layer 2 is formed thereon. In order to prevent separation of the ink layer 2, a transparent overprint layer 4 of thermoplastic resin is formed on the ink layer. Moreover, an adhesive layer 5 is provided, by using an adhesive or the like, on either surface of a label, so as to make it easy to fix the label on the internal surface of a sack or on the surface of an article to be packed, when the label is used. According to this constitution, an oxygen indicator can be fixed easily on the inside of the sack for packing or on the surface of the non-packed article, detection of oxygen is made acute, and detection thereof from outside can be facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an oxygen indicator label, and more specifically, provides an oxygen indicator label that is easy to handle and has excellent oxygen detectability.

(Prior art and its problems) Conventionally, packaging methods for products that are easily deteriorated by oxygen, such as foods, include vacuum packaging in bags made of vinylidene chloride resin coated film, which has excellent gas barrier properties, and packaging in similar bags. A method of sealing food, etc. and an oxygen absorber at the same time is used to eliminate the oxygen inside.

In these packaging methods, even if the bag has excellent gas barrier properties, oxygen may permeate inside the bag over a long period of time, or if the bag is accidentally damaged, oxygen may enter the bag and damage the packaged item. There is a problem with deterioration.

In such cases, an oxygen indicator containing a dye that develops or changes color depending on the presence of oxygen is used as a method for determining the presence or absence of oxygen inside the bag.

The oxygen indicator is made by turning a pigment and a filler in a reduced state into tablets, which are enclosed in a bag, and when oxygen permeates or penetrates into the bag, the pigment in a reduced state is oxidized and develops a color. However, it has the effect of being able to detect the presence of oxygen in the bag using Meat B.

However, in the case of the above-mentioned conventional tablet-shaped indicators, it is difficult to fix them to the inner surface of the bag or the surface of non-packaged items, so the tablets may move within the bag and become invisible from the outside, or the tablets may collapse. There are various problems such as powder generation and accidental ingestion by children.

Therefore, an object of the present invention is to provide an oxygen indicator that is easy to handle, has excellent oxygen detectability, and is free from the risk of accidental ingestion.

(Means for solving the problem) The above objects are achieved by the present invention as described below.

That is, the present invention is an oxygen indicator label characterized in that an oxygen indicator ink is printed on the surface of a sheet-like base material.

(Function) By making the oxygen indicator in the form of a label, it can be easily fixed to the inner surface of packaging bags or the surface of non-packaged items, and oxygen detection is sensitive and can be easily detected from the outside, as well as preventing accidental ingestion. Such problems do not occur.

(Preferred Embodiments) Next, the present invention will be described in more detail by citing preferred embodiments.

The oxygen indicator label of the present invention is characterized in that, as shown in the first figure, a printing ink layer 2 made of oxygen indicator ink is provided on a sheet-like base material 1.

As the sheet-like base material 1 used in the present invention, any sheet-like material conventionally used in the printing field can be used, such as various papers, synthetic papers, plastic films, metal foils, or composites thereof. Not limited.

In particular, when paper is used as the base material, the indicator ink may be impregnated into the paper, but in order to improve the oxygen detectability of the printing ink layer, it is preferable to A sealing layer 3 is formed to eliminate unevenness and ink seepage, and a printing ink layer 2 is formed thereon.

The printing ink layer formed on the sheet-like substrate is formed from an oxygen indicator ink. One example of an oxygen indicator ink contains a pigment that changes color upon oxidation and reduction.

The pigment used in the indicator ink may be any known pigment as long as it changes color (coloring, decoloring) in the oxidized state and the reduced state, but preferred pigments are colored in the oxidized state and colorless or colorless in the reduced state. It is a dye that gives a light color,
Specific examples of preferred dyes include the following dyes.

Thiazine dyes having: For example, methylene blue, Indigoid dyes having: For example, indigosulfonic acid potassium salt, Thioindigoid dyes having Mikethrene Priliant Pink R, etc. (R is -H, alkyl group, allyl group ); for example, C.I. I. Examples include sulfur blue 7, and a particularly preferred dye is methylene blue, which is a thiazine dye. Dyes such as those mentioned above can be used in either the oxidized state or the reduced state.

The above dyes can be used alone as long as they are in a reduced state, but
It is preferable to use a reducing agent in combination in order to improve the stability during inventory during label manufacture.

Further, the dye can be used in an oxidized state, and in this case, it is essential to use a reducing agent in combination. That is, in this case, the label is colored due to the presence of oxygen in the air, but when it is sealed in a bag together with an oxygen absorber, the reducing agent used in conjunction with the label acts to reduce the pigment and cause the color to change. , is kept in this state. If oxygen then enters the bag, the dye will be oxidized again and change color.

Any reducing agent that can be used in combination with the above dye can be used as long as it can maintain the dye in a reduced state, but in the case of a strong reducing agent such as hydrosulfite, the reducing agent may reduce the dye. It may over-reduce and make the dye unable to develop color.
Furthermore, when storing the label, the reducing agent itself may be oxidized by oxygen in the air, and the resulting label may not have sufficient shelf life, so it is necessary to select a dye.

From this point of view, it is preferable to use a reducing agent that has a low ability to reduce dyes at room temperature and is not easily oxidized by oxygen in the air at room temperature.

Reducing sugars are preferable as such weakening agents, and examples of such reducing sugars include D-maltose and D-maltose.
Glucose, D-Fructose, D-Ethasulose, D
- Monosaccharides such as arabinose; examples include reducing oligosaccharides consisting of glycosidic bonds of a certain number of monosaccharide molecules such as maltose and lactose; fatty acids with hydroxyl groups such as ascorbic acid can also be used. . The amount used is preferably 1 to 100 parts per 1 part of the dye (by weight, hereinafter parts and % are by weight).

In addition, it is preferable to coexist an appropriate alkaline substance in the indicator ink. As such an alkaline substance, any substance that has a pH of 8 or higher upon contact with water may be used, such as sodium hydroxide, water, etc. Potassium oxide, sodium carbonate, potassium carbonate, calcium hydroxide, calcium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, calcium hydrogen carbonate, magnesium hydroxide, sodium acetate, potassium acetate, potassium sodium tartrate, potassium 2-ethylhexanoate, etc. Examples include hydroxides, carboxylates, and various salts. The amount used is preferably 1 to 100 parts per 1 part of the above dye.

Suitable binders for converting the above pigments into ink include:
For example, suitable examples include cellulose derivatives such as ethyl cellulose, ethyl hydroxyethyl cellulose, and cellulose acetyl brobionate, butyral resin, polyester resin, acrylic resin, polyether 14 resin,
One or more types of polyamide resins, petroleum resins, etc. may be used.

These binders are preferably aromatic binders such as toluene and xylene, ester binders such as ethyl acetate and butyl acetate, ketone binders such as methyl ethyl ketone and methyl isobutyl ketone, alcohol binders such as methanol, ethanol and isopropyl alcohol, and is used after being dissolved or dispersed in an organic solvent such as ethylene glycol monoethers or glycols such as ethylene glycol, or in water.

The binder is preferably used in an amount of 5 to 20 parts dissolved or dispersed in 100 parts of the solvent.

The ink composition for forming the printing ink layer can be obtained by dissolving or dispersing the above component system in a ratio of 5 to 40 parts to 100 parts of the above resin solution. The method for dissolving or separating the components is to mix all the ingredients and knead it using a general means such as a sand mill, ball mill, roll mill, or attritor, but in order to maintain its performance as an ink for a long time, it should be kept in a sealed state. It is desirable to make it into ink.

In addition, by adding polyhydric alcohol such as glycerin or ethylene glycol to the above ink composition in an amount of about 5% of the total, the color change (discoloration) of the pigment when the label comes into contact with oxygen can be prevented. ) is effective in speeding up the process. In addition, various additives and auxiliary agents such as nonionic surfactants can also be added to the ink composition.

In addition, the above ink is prepared in a two-component type, that is, the dye (and alkaline substance) is added to the binder solution to prepare solution A, and the reducing agent is added to the bangu solution to prepare solution B.
By mixing these two liquids immediately before forming the printing ink layer, the storage stability of the ink can be improved. Furthermore, the storage stability of the printing ink layer is further improved by coating and drying the A liquid and the B liquid separately on the base material and overlapping the dye layer and the reducing agent layer to form a printing ink layer. I can do it.

Furthermore, by separately adding to the above ink composition another pigment that is not reduced within the composition system and has a different color from the dye for the printing ink layer, it is possible to not only develop color from colorless to colored. , it is possible to change colors from colored to different hues. As such pigments, general pigments and dyes that have been widely used as coloring agents for printing inks, paints, etc. can be used as they are. These other pigments can be added in an amount of about 0.5 to 5% based on the total ink composition.

Indicator inks like the ones above. For example, it can be obtained and used from Moroboshi Ink Co., Ltd., etc.

The indicator ink composition configured as above,
For example, by printing methods such as gravure printing, offset printing, letterpress printing, screen printing, or coating methods,
A printing ink layer is formed by applying it to at least one side of the sheet base material and then drying it. The printing ink layer preferably has a thickness of l to Log/rr+'' (when dry).

Furthermore, in the present invention, a transparent overprint layer 4 made of a thermoplastic resin as described above may be formed on the printing ink layer for the purpose of preventing the ink layer from falling off. In this case, there is no problem as long as the overprint layer is oxygen permeable, but if it is oxygen impermeable, it is preferable to use a gas permeable sheet such as paper as the sheet-like base material.

In addition, in the present invention, any surface of the label obtained above is adhered with a conventionally known adhesive or heat-sensitive adhesive. It is preferable to provide 5. If you do this,
When using the label, the label can be easily fixed to the inner surface of the bag or the surface of the packaged article.

When the adhesive layer 5 is made of an adhesive, it is preferable to provide a release paper 6 on its surface, and when the adhesive layer 5 is a heat-sensitive adhesive layer, no release paper is necessary.

Furthermore, as shown in the second figure, it is also possible to provide an adhesive layer on the side of the printing ink layer, which has the advantage of making it easier to observe the discoloration when it is pasted on the inner surface of the bag. .

(Effects) According to the present invention as described above, since the oxygen indicator is in the form of a label, it can be easily fixed to the inner surface of a packaging-like bag or the surface of a non-packaged article, oxygen detection is sensitive, and the oxygen indicator is in the form of a label. It is easy to detect and does not cause problems such as accidental ingestion.

(Example) Next, the present invention will be explained in more detail with reference to Examples.

Example 1 A filler (LOM) manufactured by Moroboshi Ink ■ was applied onto sterile paper (DPS, 60 g/d) manufactured by Sanyo Kokusaku Valp ■ using a gravure printing machine. Indicator ink (LOD/LOA mixture) and overprint agent (Thermolite P20V
) in this order and seal the printed matter in a polyvinylidene chloride coated bag containing an oxygen scavenger (Ageless Z-200) manufactured by Mitsubishi Gas Chemical ■, the color changes from blue-purple to red. did. When the bag was opened and exposed to air, it returned to its original blue-purple color.

Example 2 Synthetic paper manufactured by Oji Yuka Synthetic Paper ■ (Yubo FPG, 80g/rn
') was printed in the same manner as in Example 1 and subjected to the same deoxidation test, and the same reversible discoloration was observed.

Example 3 An adhesive (Olivine BPS323 manufactured by Toyo Ink Manufacturing Co., Ltd.) was applied to the back side of the printed matter obtained in Example 1 using a roll coater.
3) was coated, and a release paper was further attached to form an adhesive sheet. This sheet is cut in half and made into an adhesive sticker.
When the release paper was peeled off and the bag was placed in a bag coated with vinylidene chloride containing an oxygen scavenger similar to that used in Example 1 and sealed, the color changed from blue-purple to red. When the bag was opened and exposed to air, the original blue-purple color was restored.

Example 4 Using a gravure printing machine, a heat sealing agent (Seiksen A) manufactured by Seitetsu Kagaku ■ or a heat sealing agent manufactured by Dainichiseika Chemical Industry ■ (Seikadyne 1700) was applied to the back side of the printed matter obtained in Example 1.
W) was applied, heat-sealed to the inner surface of a bag coated with pinylidene chloride, and when an oxygen absorber was added and sealed, the color changed from blue-purple to red. When the bag was opened and exposed to air, the color returned to its original blue-purple color.

[Brief explanation of drawings]

FIGS. 1 and 2 are diagrams illustrating a cross section of an oxygen indicator label of the present invention. 1: Sheet-like base material 2: Printing ink layer 3: Sealing layer 4: Overprint layer 5: Adhesive layer 6: Release paper

Claims (2)

[Claims] (1) An oxygen indicator label characterized in that a printing ink layer made of oxygen indicator ink is formed on the surface of a sheet-like base material. (2) The oxygen indicator label according to claim 1, wherein a sealing layer is formed between the sheet-like base material and the printing ink layer, and/or an overprint layer is formed on the surface of the printing ink layer. (3) The oxygen indicator label according to claim 1, wherein an adhesive layer or a heat-sensitive adhesive layer is formed on the front or back surface.