JP3070169B2 - Sheet oxygen detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oxygen detector,
Specifically, a sheet-like oxygen detection sheet obtained by laminating an oxygen detection sheet obtained by adhering an oxygen detection paste on the entire surface or in a pattern to a gas-permeable mixed paper having self-heat sealing properties from both sides with a gas barrier film. Agent.

[0002]

2. Description of the Related Art An oxygen detecting agent is composed of a composition containing an agent having a property of indicating the presence or absence of oxygen, and various oxygen detecting agents utilizing a color reaction of a redox dye are on the market. A typical example is a tablet formed by compression-molding a mixture of a redox dye such as methylene blue, a reducing saccharide such as D-glucose, and a solid basic substance such as an alkaline earth metal oxide. Are used as a tablet-type oxygen detector enclosed in a small bag or a paper-type oxygen detector impregnated or printed on paper, and many documents relating to these are known. Prior art related to the present invention includes:
JP-A-53-120495, JP-A-56-24906,
JP-A-56-8547 and JP-A-56-84772 disclose techniques relating to tablet-type and paper-type oxygen detectors.

[0003]

In recent years, there has been developed a method for grasping the state of deoxidation by using an oxygen detector together with a deoxidizer in foods that move with moisture, such as high-moisture foods, dried foods, products containing desiccants, and the like. Has been adopted. However, as a problem in food preservation technology using an oxygen detector, the tablet-type oxygen detector absorbs moisture in a high-humidity atmosphere and the tablet easily disintegrates, and particularly, water droplets adhere to the tablet surface. The pigment in the tablet elutes, and the packaging material of the oxygen detector, the food packaging material,
It has practical disadvantages such as transfer to food itself. Further, in the paper-type oxygen detector, there is also a problem that the moisture in the detector is lost under a dry atmosphere and the detector does not discolor, and its use has been greatly restricted.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional technical problems, and is intended to detect oxygen together with a deoxygenating agent in foods such as high-moisture foods, powders, dried foods, products containing desiccants, etc. It is an object of the present invention to provide a stable oxygen detecting agent that has a small amount of water flowing into and out of the oxygen detecting agent even when used in combination, has excellent performance, and does not transfer dye.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, have applied an oxygen detecting paste to a gas permeable mixed paper (A) having a self-heat-sealing property, followed by printing or printing. The oxygen sensing sheet (C), which is adhered to the entire surface or in a pattern by impregnation, is limited to a configuration in which both surfaces of the oxygen sensing sheet (C) are laminated with a gas barrier film (D) comprising at least one layer of a plastic film. A sheet-like oxygen detector obtained by processing by limiting the gas permeability of the gas-permeable mixed paper having heat sealing properties (A) and the oxygen gas permeability and the gas permeability of the gas barrier film (D), Even when applied to applications involving the movement of moisture, such as high moisture foods, powders, dried foods, products containing desiccants, etc. It found that shooting like nor stable oxygen detecting agent is obtained, and have completed the present invention.

The present invention relates to a Gurley type air permeability of 1 to 10,000.
The oxygen detection paste is applied to a self-heat-sealing gas-permeable mixed paper (A) made of a thermoplastic plastic and a heat-insoluble plastic or paper that are water-impermeable at normal pressure and per second, the deposited on the entire surface or pattern by printing or impregnating comprising an oxygen sensor sheet (C), an oxygen gas permeability ^{20cc / m 2 · 24hr · atm} /
A sheet-like oxygen detector obtained by laminating the entire surface or partially from both sides with a gas barrier film (D) comprising at least one layer of a plastic film having a moisture permeability of not more than 25 μm and a moisture permeability of not more than 50 g / m ² · 24 hr. It is.

Hereinafter, the present invention will be described in detail. The gas-permeable mixed paper having self-heat-sealing properties (A) used in the present invention is defined as having a Gurley-type air permeability of 1 to 10,000 sec / 1.
2 ml of thermoplastic plastic and heat-insoluble plastic or paper, which are 00 ml and are impermeable to water at normal pressure
It is a gas-permeable film made by selecting and making more than one kind of material. As such packaging materials, paper / thermoplastic mixed paper made of pulp made of polyethylene, polypropylene, etc., and heat insoluble plastic / thermoplastic plastic mixed paper made of polyethylene terephthalate made of polyethylene, polypropylene, etc. Non-woven fabrics made of fibers coated with a low-melting thermoplastic such as polyethylene, with a core made of a so-called synthetic paper made of polypropylene or the like alone or a thermoplastic resin having a high melting point such as polyethylene terephthalate or the like. And the like can also be used. Also, such mixed paper,
Water-repellent, oil-repellent, etc., with a basis weight of 10 to 150 g / m
² , preferably a water-repellent and oil-repellent gas permeable film having a mixing ratio of thermoplastic resin of 20 to 80%, preferably 30 to 70% at 12 to 100 g / m ² .

The oxygen detecting sheet (C) in the present invention means the entire surface or the pattern of the gas permeable mixed paper (A) having the self-heat-sealing property by applying, printing or impregnating the oxygen detecting paste. It is a sheet formed by attaching an oxygen detection paste in a shape. The oxygen detection paste used for producing the oxygen detection sheet (C) is a composition containing a redox dye as a chemical having a property of indicating the presence or absence of oxygen, and a color reaction of the redox dye was utilized. Typical examples of the oxygen sensing composition generally include a redox dye such as methylene blue, a reducing saccharide such as D-glucose, and a solid basic substance such as an alkaline earth metal oxide. For example, a paste-like oxygen detection composition comprising methylene blue, a reducing saccharide, a basic substance, and other inking agents buffered and held at a hydrogen ion concentration of 9.0 <pH <11.5 of a strong base.

[0009] Methylene blue, which is a component of the oxygen sensing paste, is a redox dye having a colorless reduction type and a blue color oxidation type, and is used as a coloring component of a sheet-shaped oxygen sensing agent. Instead of methylene blue, redox dyes such as new methylene blue, lauth violet, methylene green, and a complex salt of methylene blue can be used.

As a basic substance, it is used in combination with methylene blue and a reducing saccharide to act as a reduction aid for the reduction reaction of methylene blue. For example, phosphoric acid, carbonic acid, silicic acid,
Basic substances having a pH buffering capacity, such as alkali metal salts of weak acids such as boric acid and organic acids, and alkaline earth metal salts can be used.

[0011] The reducing saccharide acts as a component for reducing methylene blue in the presence of a basic substance and maintaining it in a colorless reduced form. Examples thereof include D-glucose, D-xylose, D-lactose and D-galactose. Is used. Particularly, D-glucose and / or D-xylose are preferable in consideration of the reducing power.

As the inking agent, various additives such as a binder, a water repellent, a concealing agent, a colorant, a surfactant, and various auxiliaries are used. The binder is mainly added with a water-repellent binder for the purpose of imparting water repellency to the ink. For example, one or a mixture of two or more of poorly water-soluble cellulose derivatives such as ethyl cellulose, poorly water-soluble polymer substances such as polyvinyl acetal diethylaminoacetate, cellulose acetate phthalate, and shellac are used. Also,
The water repellency adjusting agent is added for the purpose of adjusting the water repellency of the ink, and maintains an appropriate water solubility in combination with the water repellent binder. For example, one or a mixture of two or more of natural or synthetic water-soluble polymer compounds such as polyvinyl alcohol, methylcellulose, polyacrylic acid and a salt thereof, hydroxymethylcellulose, hydroxyethylcellulose, and hydroxypropyl cellulose are used.

[0013] The concealing agent is added for the purpose of clearly coloring the ink. For example, a white pigment such as titanium oxide is used. In consideration of the fact that the coloring agent is used in food packaging, food coloring is used, and the redox dye is reduced under deoxygenation to color the colorless ink to reduce the deoxygenation state. Plays the function of displaying.

The method for producing the ink which is the oxygen detection paste used in the present invention can be produced by a general ink production method. For example, first, a redox dye, a reducing saccharide, a basic substance, and a colorant Or, after blending a predetermined amount of each solution heated and dissolved in water to form a solution in which the hydrogen ion concentration is adjusted to a strong base, then blending a predetermined amount of an inking agent,
The ink is manufactured by dispersing with a dispersing machine such as a bead mill, a sand mill, a ball mill, and an attritor.

The oxygen detecting paste is a gas permeable material having a self-heat-sealing property by a printing method such as gravure printing, screen printing, offset printing, letterpress printing, a coating method using a roll coater or a knife coater, or an impregnation method. To obtain an oxygen detection sheet (C) by adhering to the entire surface of the mixed paper (A) or in a pattern.

The gas barrier film (D) used in the present invention means that the oxygen gas permeability is 20 cc / m ² · 24 hr ·
atm / 25 [mu] m or less, and moisture permeability, a TOPS plastic film is less than 50g / m ² · 24hr, 7~200 comprising at least one layer selected from these [mu] m, preferably of 12~50μm It is a gas barrier thin film having a thickness. As such a packaging material, a plastic film laminated or coated with polyvinylidene chloride or the like, a transparent film formed by laminating an ethylene-vinyl alcohol copolymer film, or a film composed of a transparent portion and an opaque portion is used.

If the oxygen permeability of the gas barrier film (D) exceeds 20 cc / m ² · 24 hr · atm / 25 μm and / or the moisture permeability exceeds 50 g / m ² · 24 hr, the gas barrier is insufficient. The performance of the oxygen detector is significantly deteriorated due to the deterioration of the oxygen detection agent, and the object of the present invention cannot be achieved. Have difficulty. On the other hand, if the film thickness is 7μ
If it is less than m, the film is too thin to be processed and not only has poor durability, but if it is more than 200 μm, the film lacks flexibility and becomes difficult to process. Therefore, the packaging material is appropriately selected based on the degree of gas barrier property in consideration of the processability of the packaging material, the expansion of uses of the oxygen detector, and the like.

Further, such a gas barrier film (D)
Is to provide a sealing layer inside the packaging material to improve laminating processability with a self-heat-sealing gas-permeable mixed paper (A) which is a base material of the oxygen detection sheet (C). Is also possible. Further, the heat lamination strength of the sheet-like oxygen detecting agent in the present invention varies depending on the type and thickness of the resin of the sealant film, heat sealing conditions and the like.

Examples of the plastic film used as the inner sealing layer include polyethylene, ethylene-vinyl acetate copolymer having a softening point equal to or lower than that of gas-permeable mixed paper (A) having self-sealing properties,
There is a thermal laminating process of a low melting point sealant film such as an ionomer resin.

The sheet-like oxygen sensing agent of the present invention comprises an oxygen sensing sheet (C) obtained by adhering an oxygen sensing paste on the entire surface or in a pattern on a gas-permeable mixed paper (A) having self-sealing properties. It is obtained by laminating the entire surface or partially with the gas barrier film (D) from both sides, and is manufactured so that at least a part of one side is transparent and the discoloration of the attached portion of the oxygen detecting paste can be determined. When using a film composed of a transparent and opaque portion as the gas barrier film (D), the transparent portion is laminated on the oxygen sensing sheet (C) to which the oxygen sensing paste is attached. When laminating from both sides with the gas barrier film (D), the gas barrier film (D) used in the present invention is used on one side, and the other side is formed by vapor deposition of metal other than the gas barrier film. A laminated film such as a plastic film imparted with a property or a metal foil such as aluminum can be used.

The sheet-like oxygen detecting agent is a gas barrier film (D) that blocks the flow of gas such as oxygen and water vapor from the surface of the oxygen detecting sheet (C) to form a gas-permeable mixed paper (A). ) Is laminated using the self-heat-sealing property given to the above, and gas-permeable mixed paper mixed with heat-insoluble paper or heat-insoluble plastic (A) loses gas permeability even after lamination. The mixed paper portion in the cross section of the sheet-like oxygen detector is used as a gas vent. In the case of using the sheet-like oxygen detecting agent, the gas-barrier film (D) and the oxygen detecting sheet (C) are partially laminated (at least the peripheral portion is laminated) instead of being entirely laminated, and the self-heat sealing is also performed. The gas permeability of the mixed paper portion of the seal cross section of the gas permeable mixed paper (A) having the property is maintained.

The sheet-like oxygen detector of the present invention can be used in combination with a deoxygenator and a sheet-like oxygen detector for foods that move with moisture, such as high-moisture foods, powders, dried foods, and products containing a desiccant. There is little inflow and outflow of water into and from the oxygen detector, and excellent performance is exhibited. In addition, it is an oxygen detector having good stability over time without transfer of dye or the like. Here, as the oxygen scavenger used, one containing a metal powder such as sulfite, hydrogen sulfite, nitrite, hydroquinone, catechol, resorcinol, pyrogallol, gallic acid, iron powder, ascorbic acid, etc. is used. Is not particularly limited.

[0023]

According to the present invention, an oxygen detecting sheet (C) obtained by adhering an oxygen detecting paste on the entire surface or in a pattern on a gas-permeable mixed paper (A) having a self-heat-sealing property is used as a gas barrier film (D). ) Is a sheet-like oxygen detector laminated on both sides, wherein the sheet-like oxygen detector is a gas-permeable mixed paper having self-heat-sealing properties (A) itself. Non-heat-sealing paper and other materials are not used alone, but limited to self-sealing mixed paper made from a mixture of thermoplastic plastic and heat-insoluble plastic or paper, and non-breathable The packaging material is also processed with a packaging material configuration limited to the gas barrier film (D).

The flow of gas such as oxygen and water vapor from the surface of the oxygen detecting sheet (C) generated during use of the sheet-like oxygen detecting agent is blocked at the gas barrier film (D) layer to prevent the oxygen detecting agent The gas permeable mixed paper (A) provided with a self-heat-sealing property to prevent the deterioration of the oxygen detector due to the loss of water and the deterioration of the redox dye. Even after laminating both sides with film (D), the gas permeability of the mixed paper portion of the cross-section portion which is the gas vent of the sheet-like oxygen detector mixed with heat-insoluble plastic or heat-insoluble paper is not lost. I have.

Therefore, the sheet-like oxygen detector can be used for detecting oxygen even when the oxygen detector is used together with a deoxidizer in foods that move with moisture, such as high-moisture foods, powders, dried foods, and products containing desiccants. Excellent performance due to less outflow and inflow of water into the agent. Moreover, there is no transfer of the dye and the like, and an oxygen detector having good stability over time can be obtained.

Further, the layer of the gas-permeable mixed paper (A) constituting the oxygen detecting sheet (C) of the sheet-like oxygen detecting agent is adopted as a gas ventilation part, and the gas-permeable mixed paper (A) is used. ) Is limited to a self-heat-sealing mixed paper made of thermoplastic plastic and heat-insoluble plastic or paper, and the material without heat seal such as paper is not used. Has good workability and can exhibit stable performance.

Further, the air permeability of the gas-permeable portion of the sheet-like oxygen detecting agent, wherein the layer of the gas-permeable mixed paper (A) constituting the oxygen-sensing sheet (C) of the sheet-like oxygen detecting agent is a gas-permeable portion. The degree can be adjusted by changing the thickness of the gas-permeable mixed paper (A), the mixing ratio of the thermoplastic plastic and the heat-insoluble plastic or paper, and the like. In addition, since the lamination strength of the sheet-shaped oxygen detector is affected by the mixing ratio of the thermoplastic plastic and the heat sealing conditions, the mixing ratio is determined in consideration of the air permeability. Therefore, in the present invention, the gas-permeable mixed paper (A) is reproduced as it is while maintaining the original properties of the packaging material itself, such as air permeability, durability, and bag-making properties, so that it is always stable. A sheet-like oxygen detector that can exhibit performance is obtained.

[0028]

The present invention will be described more specifically with reference to examples and comparative examples. However, the scope of the present invention is not limited by these examples. (1) Preparation of oxygen detection agent sample and oxygen detection agent comparison sample Prior to preparation of the oxygen detection agent sample and the oxygen detection agent comparison sample, sample 1, sample 2 (a) and sample 2 (b) of oxygen detection sample A
Sample 2 (c) was prepared, and the above-mentioned inking agent was added thereto to prepare Samples 3, 4 (a), 4 (b) and 4 (c) of oxygen detection paste samples.

Sample-1 Methylene blue / ethanol solution in which 0.8 part of methylene blue was dissolved in 80 ml of ethanol: 64 parts, 0.08 part of red
Red No. 106 aqueous solution in which No. 106 (colorant) is dissolved in 10 ml of water: 10.08 parts, 60 parts of trisodium phosphate dodecahydrate (basic substance) is dissolved in 300 ml of water. 360 parts and 70 parts of D (+) xylose (reducing saccharide) dissolved in 70 ml of water: 140 parts of an aqueous D (+) xylose solution were heated and dissolved, and then mixed to prepare solutions.

Sample-2 In the preparation process of Sample-1, the type of basic substance and
Except for changing the blending amount (basic substance / reducing saccharide ratio),
Sample-2 (a), (b),
(C) was adjusted.

Sample-3 Sample-1: 100 parts of hydroxyethylcellulose (viscosity modifier): 4 parts were added to adjust the viscosity. Next, 12 parts of titanium oxide (hiding agent), 50 parts of ethyl cellulose (water-repellent binder) dissolved in 150 ml of ethanol in ethyl cellulose / ethanol solution: 20 parts, and 10 parts of polyvinyl alcohol (water-repellent modifier) Was dissolved in 150 ml of water: a mixed solution obtained by adding 24 parts of a polyvinyl alcohol aqueous solution was uniformly dispersed with a pigment in a bead mill to prepare an oxygen detection paste.

Sample-4 In the preparation process of Sample-3, the types and amounts of the viscosity modifier and the concealing agent (filler) were changed, and Sample-4 (a), (b) was prepared in the same manner as Sample-3. ) And (c) were prepared. Tables 1 and 2 show the composition of the oxygen detection sample A and the oxygen detection paste prepared as described above. For the oxygen detection paste, the hydrogen ion concentration was measured with a pH meter (5 g of the sample was dispersed in distilled water, and the total amount was 100 g.
And the results are shown in Table 2.

[0033]

[Table 1]

[0034]

[Table 2]

Sample-5 The oxygen sensing paste prepared in Sample-3 was mixed with pulp / PE
A gas-permeable mixed paper (basic weight: 60 g / m ² , pulp mixed with PE at a rate of 60% (A)) is coated in a circular pattern with a thickness of about 100 μm and an oxygen detection sheet ( C). Next, a transparent K-NY / PE film [a nylon (thickness: 30 μm) and a PE (thickness: 16 μm) laminated film prepared by an extrusion laminating method) was coated with polyvinylidene chloride from both sides of the oxygen sensing sheet (C). The coated gas barrier film (D)] was laminated to prepare a sheet-like oxygen detector.

Sample-6 In the preparation process of Sample-5, instead of the oxygen sensing paste adjusted in Sample-3, the oxygen sensing paste samples-4 (a), (b), and ( An oxygen detection sheet (C) was prepared in exactly the same manner as in Sample-5, except that c) was applied to the entire surface of the pulp / PE mixed paper. Next, samples -6 (a), (b), and (c) were prepared by laminating a transparent gas barrier film (D) on both sides of the oxygen detection sheet (C) in exactly the same manner as in the preparation process of sample -5.
(C) and oxygen detection paste sample-3, sample-4
(A) and (b) are coated on the entire surface of pulp / PE mixed paper, and the oxygen sensing sheet (C) is partially laminated (only on the peripheral portion) without laminating the entire surface with the gas barrier film (D). Heat-sealed) sample-6 (h),
(I) and (j) sheet-like oxygen detectors were prepared.

Sample-7 The sheet-like oxygen detector of Sample-7 was prepared in exactly the same manner as in Preparation of the sheet-like oxygen detector of Sample-5, except that the oxygen detection paste was applied to both the front and back surfaces of the pulp / PE mixed paper. An agent was prepared.

Sample-8 The oxygen sensing paste prepared in Sample-3 was mixed with pulp / PE
An oxygen detection sheet (C) was formed by applying a circular pattern with a thickness of about 100 μm on the mixed paper. Next, instead of using the transparent gas barrier film (D), use the gas barrier film (D) consisting of a transparent portion and an opaque portion on one side, and align the transparent portion on the oxygen sensing paste, and connect the other surface to the other. Sample-8: Laminated from both sides of oxygen detection sheet (C) using various kinds of opaque gas barrier films (PET / Al / PE)
Was prepared.

Comparative Sample-1 In the preparation process of Sample-5, pulp / PE mixed paper [basal weight: 60 g / m ² , gas-permeable mixed paper (A) made by mixing pulp with PE at a ratio of 60%] Into rayon paper (tsubo: 60g /
m ² ) or a wet non-woven fabric (basis weight: 50 g / m ² ) except for using a sheet-like oxygen detector in the same manner as in Sample-5:
Comparative samples-1 (a) and (b) were prepared.

Comparative Sample-2 In the preparation process of Sample-5, the oxygen detection sheet (C) was changed to a transparent gas barrier film (D) laminated on both sides, and a polystyrene fill (thickness: 20 μm) was used.
In the same manner as in Sample-3, except for the use of Sample-3, a sheet-like oxygen detecting agent: a gas barrier film (D) from both sides using only the oxygen detecting sheet (C) prepared in Comparative Sample-2 (a) and Sample-5. Comparative sample without lamination)
2 (b) was prepared.

Comparative Sample-3 Aluminum hydroxide: 368.5 parts, titanium oxide (hiding agent): 20 parts, 50 parts of ethylcellulose (water-repellent binder)
Ethylcellulose / ethanol solution in which 150 ml of ethanol was dissolved: 169 parts were charged into a kneader, mixed under heating to evaporate part of the ethanol, and then 0.4 parts of methylene blue dissolved in 40 ml of ethanol. Solution: 32 parts and 0.04 part of Red No. 106 (colorant) dissolved in 5 ml of water Red No. 106 aqueous solution:
5.04 parts were added, and the mixture was heated and mixed to evaporate almost all of the ethanol. Next, 16 parts of an aqueous polyvinyl alcohol solution obtained by dissolving 1 part of polyvinyl alcohol (water repellency adjusting agent) in 15 ml of water was added, heated and mixed, dried, and then 35 parts of D (+) xylose (reducing property) was added. Aqueous solution of D (+) xylose in 35 ml of water: 70 parts and 25 parts of trisodium phosphate dodecahydrate (basic substance) in 125 ml of water: 150 parts And heated and dried to obtain granules. (Moisture content in granules: 35
%) When the hydrogen ion concentration was measured by the same test method as that for the oxygen detection paste, a pH of 11.2 was obtained.

To 100 parts of the granules, 2 parts of calcium stearate (lubricant) were added, and a blue tablet-type oxygen detector obtained by tableting using a tableting machine was added to a transparent NY / PE
Oxygen detecting agent filled with a film [laminated film made by extrusion lamination and made of NY (thickness: 30 µm) and PE (thickness: 16 µm)] one by one, and then pinholed with a needle: Comparative sample- 3 was produced.

(2) Various Evaluation Tests of Oxygen Detector Each of the oxygen detector sample and the oxygen detector comparative sample prepared in the above section (1) was examined for its discoloration speed, discoloration oxygen concentration, processability, and the like. The results are shown in Table 3 below.

(A) Discoloration rate Each of the oxygen detector sample and the oxygen detector comparison sample was sealed in a nitrogen atmosphere having an oxygen concentration of 0.1% or less and kept at 20 ° C. The time required until the color changed from blue to pink was measured, and the average value was taken as the color change speed.

(B) Discolored Oxygen Concentration Several samples of each oxygen detection agent sample and oxygen detection agent comparison sample were sealed in atmospheres having different oxygen concentrations, kept at 20 ° C., and left for 24 hours. The color tone of the sample at each oxygen concentration was measured, and the average of the measured values of the oxygen concentration at which the sample changed color from blue to pink was defined as the discolored oxygen concentration.

(3) Practicality test of oxygen detecting agent For each of the oxygen detecting agent samples and the oxygen detecting agent comparative samples prepared in the above item (1), the actual use conditions were assumed, and the oxygen content was determined by the following items. The color change time of the detection agent was measured. The number of samples was all 10 and the measurement results are shown in Tables 3 and 4.

[0047]

[Table 3]

[0048]

[Table 4]

(A) Standard Test Method For each of the oxygen sensing agent sample and the oxygen sensing agent comparative sample prepared in the above (1), an oxygen barrier packaging material (KON
/ PE, 15 × 30 cm) bag with the oxygen detecting agent sample and oxygen absorber with an oxygen absorption capacity of 100 ml and 50 × 5
After enclosing the oxygen-absorbing agent package packed and packed in a 0 mm packaging material, and further sealing it by injecting 500 ml of air,
, And the time from when the oxygen concentration became zero to when the oxygen detector changed color from blue to pink was measured, and the average value was defined as the color change time.

(B) Mounting Test Method In the above standard test method, raw cut rice cake (high moisture food), peanut (dry food), and crunchy plum (acid food) were used in addition to the oxygen detector sample and the oxygen absorber package. 200g each
Unless enclosed, the discoloration time was measured in exactly the same way as in the standard test method.

(C) Temporal stability test In the above mounting test method, after discoloration of the oxygen detecting agent, the oxygen detecting agent was allowed to stand at room temperature for a long period of time to observe changes in the oxygen detecting agent for each elapsed time. Compared.

[0052]

The sheet-like oxygen detector of the present invention can be used in combination with a deoxidizer and an oxygen detector in foods with a movement of moisture, such as high-moisture foods, powders, dried foods, and products containing desiccants. Excellent performance due to less outflow and inflow of moisture to the oxygen detector. Moreover, there is no transfer of the dye and the like, and an oxygen detector excellent in stability over time can be obtained. Therefore, its significance in the food and other industries is extremely large.

[Brief description of the drawings]

FIG. 1 is a sheet-like oxygen detector of the present invention (Examples 1 to 4).
FIG.

[Explanation of symbols]

 A: Gas-permeable mixed paper having self-heat-sealing properties B: Oxygen detection paste C: Oxygen detection sheet D: Gas barrier film E: Laminated layer F: Sheet oxygen detector

FIG. 2 shows a cross-sectional view of a sheet-like oxygen detector (Example 7) of the present invention.

[Explanation of symbols]

 A: Gas-permeable mixed paper having self-heat-sealing properties B: Oxygen detection paste C: Oxygen detection sheet D: Gas barrier film E: Laminated layer F: Sheet oxygen detector

FIG. 3 shows a cross-sectional view of a sheet-like oxygen detector of the present invention (Example 8).

[Description of Signs] A: Gas-permeable mixed paper having self-heat-sealing properties B: Oxygen detection paste C: Oxygen detection sheet D: Gas barrier film E: Laminate layer F: Sheet oxygen detector G: Gas barrier H: opaque part of gas barrier film (D) I: opaque part of gas barrier film (other type)

FIG. 4 is a sheet-like oxygen detector of the present invention (Examples 5 to 7).
FIG.

[Explanation of symbols]

 A: Gas permeable mixed paper having self-heat-sealing properties B: Oxygen detection paste C: Oxygen detection sheet D: Gas barrier film E: Laminate layer F: Sheet oxygen detector J: Seal layer K: Space margin)

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoichi Yamakawa 2-2-1 Otemachi, Chiyoda-ku, Tokyo Inside Soda Co., Ltd. (56) References Japanese Utility Model 1983-156266 (JP, U) (58) Survey Field (Int.Cl. ⁷ , DB name) G01N 31/00

Claims (2)

(57) [Claims] 1. Gurley-type air permeability of 1 to 10,000 seconds / 100 ml
By applying, printing or impregnating an oxygen sensing paste on a self-heat-sealing gas-permeable mixed paper (A) made of a thermoplastic plastic and a heat-insoluble plastic or paper which are impermeable to water at normal pressure. Oxygen detection sheet (C) attached on the entire surface or in a pattern
A gas barrier film (D) comprising at least one layer of a plastic film having an oxygen gas permeability of 20 cc / m ² · 24 hr · atm / 25 μm or less and a moisture permeability of 50 g / m ² · 24 hr or less A sheet-like oxygen detector obtained by laminating the entire surface or partially from both sides. 2. The sheet-like oxygen detector according to claim 1, wherein the gas barrier film (D) is a transparent film or a film comprising a transparent portion and an opaque portion.