JP4600987B2 - Oxygen-absorbing container - Google Patents

Description

  The present invention relates to a container made of a synthetic resin sheet for storing food and the like, and in particular, quickly absorbs oxygen remaining in the container and oxygen contained in food and the like, and oxygen is externally supplied during the storage period. The present invention relates to an oxygen-absorbing container having a function of preventing permeation.

  Conventionally, by filling an iron-based oxygen-absorbing composition made of iron powder or the like into a sachet having good air permeability and storing the sachet or the like together with the contents in a food container having oxygen barrier properties, Prevention of oxidative deterioration of the contents, generation of mold, growth of aerobic microorganisms, and the like has been widely performed. Since this method does not require an expensive device, it is applied in a wide variety of ways.

  However, this method is difficult to use from the viewpoints of hygiene, quality, and the like because the oxygen-absorbing composition may leach out of the sachet for liquid or watery foods. In addition, the iron-based oxygen-absorbing composition is sensitive to a metal detector for detecting a metal foreign substance mistakenly mixed in the container, and the original inspection purpose cannot be achieved. Furthermore, when heating with a microwave oven, there was an inconvenience that the film was peeled off and the sachet filled with iron powder or the like had to be removed from the container.

Therefore, as a method for eliminating such inconvenience, an oxygen absorbing layer in which an oxygen absorbing layer in which an oxygen absorbing composition composed of powdered or granular metallic iron is mixed in a thermoplastic resin sheet material constituting a container is provided. (See, for example, Patent Document 1). This oxygen-absorbing container is currently used as a packaging container for sterile cooked rice.
Japanese Patent Publication No. 6-51397 (see pages 1 to 4)

  However, since the above-described oxygen-absorbing container uses iron powder or the like as the oxygen-absorbing composition, the metal detector for detecting the metal foreign matter mixed in the container is still erroneously sensitive or electronic. When heating in the range, there remains a problem that the danger of ignition etc. cannot be excluded.

  Accordingly, an object of the present invention is a sheet that has an excellent absorption function of oxygen remaining inside the container, an excellent barrier function against oxygen entering from the outside of the container, and is not affected by heating by a microwave oven and inspection by a metal detector. An object of the present invention is to provide an oxygen-absorbing container using a material.

  In order to solve the above problems, a first feature of the oxygen-absorbing container according to the present invention is a container in which a sheet material is thermoformed, and this sheet material is an oxygen in which low-order titanium oxide is mixed with a thermoplastic resin. It includes an absorbent layer, an oxygen barrier layer having adhesive layers on both sides, and an outer surface layer made of a thermoplastic resin, and is arranged in this order from the inside of the container.

  A second feature of the oxygen-absorbing container according to the present invention is that the sheet material is provided with an inner surface layer made of a thermoplastic resin on the inner surface of the container.

The total thickness of the sheet material described in the above feature 1 is 0.2 to 2 mm, the thickness of the oxygen absorption layer is 50 to 300 μm, and the thickness of the oxygen barrier layer is 20 to 100 μm. Titanium has a crystal structure represented by the general formula TiO _2-x (x represents a real number of 0.1 to 0.5), and the content of the low-order titanium oxide is the weight of the sheet material. It is desirable that it is 3 to 15 wt%.

The total thickness of the sheet material described in the above feature 2 is 0.2 to 2 mm, the thickness of the inner surface layer is 50 to 300 μm, the thickness of the oxygen absorption layer is 50 to 300 μm, and the thickness of the oxygen barrier layer is 20 to 100 μm. The low-order titanium oxide in the oxygen absorption layer has a crystal structure represented by the general formula TiO _2-x (x represents a real number of 0.1 to 0.5). The titanium content is desirably 3 to 15 wt% of the weight of the sheet material.

  The inner surface layer is mixed with a water-absorbing substance that adds a water permeation function, and the inner surface layer permeates at least 15 wt% of water of the low-order titanium oxide contained in the oxygen absorption layer per day. It is desirable to be a thing. Further, the oxygen absorbing layer is mixed with a water-absorbing substance that adds a water absorbing function, and this oxygen absorbing layer has a moisture content of at least 15 wt% of the weight of the low-order titanium oxide contained in the oxygen absorbing layer per day. It is desirable to absorb water.

  It is desirable that a protective layer for preventing water permeation is provided between the oxygen absorbing layer and the oxygen barrier layer. Furthermore, it is desirable that a printed film with a transparent part left in part is adhered to the outer surface of either the inner surface layer or the outer surface layer.

  The water-absorbing substance is desirably either a hydrophilic organic compound or an inorganic substance having moisture adsorption. Further, it is desirable that the inner surface layer is a foam layer.

  Next, the contents of the above-described oxygen-absorbing container will be described in detail including actions and the like. The “container in which the sheet material is thermoformed” means a sheet member that is heated and molded into a predetermined shaped container by a mold or the like, such as indirect heating vacuum molding, indirect heating plug assist vacuum molding, Alternatively, a known thermoforming method such as direct heating hot plate molding is applicable. Here, the “container” means a container that can contain food and the like and can be sealed, regardless of its shape or size. For example, a container having an opening at the top, which contains a food or the like and the opening is sealed with a film, a lid, or the like, is applicable.

  The “oxygen absorption layer” that constitutes the sheet material adsorbs oxygen in the air sealed inside the container, oxygen dissolved in food, and oxygen that permeates through the container material from the outside of the container. It means what is to be fixed and "low order titanium oxide" mixed with "thermoplastic synthetic resin". Here, “low-order titanium oxide” is a known technique in which titanium dioxide is subjected to a reduction reaction in an oxygen-free state so as to have an oxygen defect while maintaining the crystal structure of titanium dioxide. is there. In an oxygen atmosphere or the like, the oxygen defect portion absorbs oxygen and returns to the original stable crystal structure of titanium dioxide, thereby achieving an excellent oxygen absorbing function.

  “Thermoplastic synthetic resin” mixed with low-order titanium oxide includes polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymer, polybutene, polymethylpentene, ethylene vinyl acetate copolymer, high impact polystyrene, styrene- Polystyrene such as butadiene copolymer, thermoplastic polyester such as polyethylene terephthalate, polybutylene terephthalate, and the like are applicable, but not only when these are used alone, but also when a plurality of types are used in combination.

  Next, the “oxygen barrier layer” blocks oxygen that has permeated from the outside of the container, and the low-order titanium oxide contained in the oxygen absorbing layer described above is rapidly consumed by oxygen entering from the outside. It means a layer for preventing the absorption function from being lowered or lost, and a known oxygen barrier resin can be used. For example, one or more of polyamide such as MXD6, ethylene vinyl alcohol copolymer, and polyglycolic acid can be selected or used in combination. In particular, MXD6 is preferable under the condition where moisture is present, since the decrease in barrier function is extremely small. Further, in order to reduce the amount of expensive oxygen barrier resin used or to improve the oxygen barrier function, an oxygen barrier layer / adhesive layer / oxygen barrier layer is interposed between the oxygen barrier layers via an adhesive layer. Three or more layers can be formed.

  The “adhesive layer” disposed on both surfaces of the oxygen barrier layer means a layer for providing an adhesive force between the oxygen barrier layer and an oxygen absorbing layer or an outer surface layer described later, such as maleic anhydride-modified polypropylene. Is applicable.

  In addition, the “outer surface layer made of a thermoplastic resin” improves the rigidity and heat resistance of the container, and depending on the barrier resin used for the oxygen barrier layer described above, the oxygen barrier function may be reduced by moisture. (For example, ethylene vinyl alcohol copolymer) means a layer that prevents moisture permeated from the outside of the container from entering the oxygen barrier layer. In addition, as described later, the oxygen absorbing layer is gray before absorbing oxygen, so that the outer surface layer is colored or patterned, or a printed film is attached to improve the appearance and the like. Means the layer.

  For the outer surface layer, polyethylene, polypropylene, ethylene-propylene copolymer, polybutene, polymethylpentene, polyolefin such as ethylene vinyl acetate copolymer, high impact polystyrene, polystyrene such as styrene-butadiene copolymer, polyethylene terephthalate, and Among thermoplastic polyesters such as polybutylene terephthalate, one or more can be used alone or in combination. In addition, the pigment, calcium carbonate, and the like generally used for packaging containers within the range that does not impair the effect of the present invention for improving the concealability and physical properties of the container (improvement of rigidity, heat resistance, oxygen barrier properties, etc.) Inorganic fillers such as talc, clay and mica can be blended.

  The oxygen absorbing layer described above, the oxygen barrier layer having adhesive layers on both sides, and the outer surface layer made of a thermoplastic resin are arranged in this order from the inside of the container. This is because oxygen in the air sealed inside the container and oxygen dissolved in the food or the like are absorbed. That is, the low-order titanium oxide mixed in the oxygen absorbing layer exhibits its oxygen absorbing function in the presence of moisture. Therefore, by disposing the oxygen absorbing layer inside the container, moisture contained in the food or the like serves as a medium, and oxygen in the container can be absorbed.

  On the other hand, since infinite oxygen exists in the atmosphere outside the container, it is necessary to prevent the oxygen absorption layer from absorbing oxygen in the atmosphere and deteriorating the oxygen absorption function. For this reason, an oxygen barrier layer is provided outside the oxygen absorption layer to prevent the oxygen absorption layer from absorbing oxygen in the atmosphere. In addition, since some barrier resins used for the oxygen barrier layer have a reduced oxygen barrier function in the presence of moisture, an outer surface layer is provided outside the oxygen barrier layer. Is prevented from passing through.

  In the feature 2 described above, the “inner surface layer made of a thermoplastic resin” provided inside the oxygen absorbing layer is a mixture of a water-absorbing substance that adds a moisture permeation function, which will be described later, or has moisture adsorbing properties. Means a layer that can be In addition, this “inner surface layer made of thermoplastic resin” has a function of improving the concealment and appearance of the oxygen-absorbing layer by coloring or patterning with a pigment, or attaching a print film, etc., similar to the outer surface layer described above. In addition, as described above, when the opening of the container is sealed with a film or a lid and sealed, it also has a function of adding a physical property improving agent that improves sealing performance. The inner surface layer is made of polyolefin such as polyethylene, polypropylene, ethylene-propylene copolymer, polybutene, polymethylpentene, ethylene vinyl acetate copolymer, polystyrene such as high impact polystyrene, styrene-butadiene copolymer, polyethylene terephthalate and poly Among thermoplastic polyesters such as butylene terephthalate, one or more can be used alone or in combination. For the “inner surface layer”, it is more preferable to use an ethylene vinyl acetate copolymer that is excellent in oxygen permeability, water vapor permeability, and sealing properties and has a good balance of physical properties.

  In the feature 1 described above, the total thickness of the sheet material is set to “0.2 to 2 mm”. When the total thickness of the sheet material is less than 0.2 mm, the basic physical properties as a container (maintenance of shape, strength, This is because a product satisfying impact resistance or the like cannot be obtained, and if it is thicker than 2 mm, it becomes excessive quality as a packaging container. In addition, when the thickness of the oxygen absorbing layer is set to “50 to 300 μm”, in order to obtain a necessary oxygen absorbing function when it is thinner than this thickness, it is necessary to mix low-order titanium oxide at a high concentration, In such a case, the dispersibility of the low-order titanium oxide is deteriorated, causing problems such as pinholes during sheet molding and poor appearance during sheet material molding. On the other hand, when it is thicker than 300 μm, the concentration of the oxygen absorbing layer is lowered, so that the distance between the low-order titanium oxides is widened and the oxygen absorption efficiency is deteriorated. Furthermore, it is because it becomes difficult for the water | moisture content used as the oxygen absorption initiator (trigger) to penetrate the whole oxygen absorption layer.

  The reason why the thickness of the oxygen barrier layer is set to “20 to 100 μm” is that the thicker this layer is, the higher the oxygen barrier function from the outside is. is there. On the other hand, if it is thinner than 20 μm, the required oxygen barrier function cannot be obtained.

The low-order titanium oxide mentioned above is said to have a crystal structure represented by the general formula TiO _2-x (x represents a real number of 0.1 to 0.5). This is to more specifically define the structure of the above, and those having an anatase type, rutile type or brookite type crystal structure are respectively applicable. More preferably, those having an anatase type crystal structure are used. The shape and particle size of the low-order titanium oxide mixed as the oxygen absorbing layer is not particularly limited, and may be, for example, granular, spherical, granular, or powdery. In addition, since the one where the total surface area of the whole is excellent in the oxygen absorption capability, the particle size is preferably about 1 nm to 10 μm, more preferably 3 nm to 1 μm.

  When the content of the low-order titanium oxide described above is “3 to 15 wt% of the weight of the sheet material”, if it is less than 3 wt%, the necessary oxygen absorption function cannot be obtained, whereas if it exceeds 15 wt%, Since the concentration of low-order titanium oxide in the oxygen absorption layer increases, the dispersibility of low-order titanium oxide deteriorates, causing pinholes during sheet molding and poor appearance during sheet material processing. Because it happens.

  In the above-described feature 2, the thickness of the inner surface layer is set to “50 to 300 μm”. The thinner the thickness, the better the water permeability, so that the oxygen absorption rate is improved. This is because the gray concealability is insufficient, and on the other hand, if it is thicker than 300 μm, the water permeability becomes poor.

  The reason why the above-described inner surface layer is mixed with a “water-absorbing substance” that adds a moisture permeation function is that the low-order titanium oxide described above has a moisture as an oxygen absorption initiator (trigger). ”Is mixed with the inner surface layer so that moisture contained in food sealed in the container is absorbed as soon as possible, and the absorbed moisture is permeated to come into contact with the oxygen absorbing layer mixed with low-order titanium oxide. Because.

  In addition, the inner surface layer “permits at least 15% of the weight of the low-order titanium oxide contained in the oxygen-absorbing layer per day” because the low-order titanium oxide has a moisture content as described above. Serves as an oxygen absorption initiator (trigger). However, when the water content is 15 wt% or more of the weight of the low-order titanium oxide, the oxygen absorption function is more effectively exhibited. The initial oxygen absorption function is determined by how quickly this amount of water is brought into contact with the low-order titanium oxide, and it is possible to more reliably prevent oxidative deterioration of the contents of foods, generation of mold, growth of aerobic microorganisms, etc. In order to do this, it is usually necessary to extremely reduce the oxygen concentration in the container within one day. Therefore, oxidative deterioration of foods and the like can be more reliably prevented by mixing the inner surface layer with a water-absorbing substance that transmits water of 15 wt% or more of the weight of the low-order titanium oxide per day.

  “The oxygen absorbing layer is mixed with a water-absorbing substance that adds a moisture absorbing function, and this oxygen absorbing layer contains at least 15 wt% of moisture per day of the low-order titanium oxide contained in the oxygen absorbing layer. “Absorb” means mixing an oxygen absorbing layer in which low-order titanium oxide, which is an oxygen absorbent, is mixed and dispersed with a water-absorbing substance that adds a function of absorbing water of 15 wt% or more of the contained low-order titanium oxide. This means that the oxygen absorption efficiency of the oxygen absorption layer is improved. In addition, both the case where a water absorbing substance is mixed only in an oxygen absorption layer, and the case where it mixes also in an inner surface layer are included.

  As described above, the “protective layer for preventing water permeation” provided between the oxygen absorbing layer and the oxygen barrier layer is a barrier resin used for the oxygen barrier layer, which has an oxygen barrier function when moisture is absorbed. This means a layer for preventing moisture that reaches the oxygen absorption layer from food or the like sealed in a container from passing through the oxygen absorption layer and reaching the oxygen barrier layer. The “protective layer” corresponds to a resin having a water absorption rate of 0.1% or less as measured by ASTM D570, such as high-density polyethylene and polypropylene resin.

  “Affixing a printed film with a transparent part in part on the outer surface of either the inner surface layer or the outer surface layer” described above means that, for example, characters are applied to the outer surface of either the inner surface layer, the outer surface layer, or both. This means that a transparent printing film printed with white is attached to the other part, leaving only the part of the shape. That is, as described above, when low-order titanium oxide is kneaded and dispersed in a thermoplastic resin, the thermoplastic resin is colored gray by the low-order titanium oxide, and when this low-order titanium oxide absorbs oxygen, it becomes ordinary titanium dioxide. Turns white. Therefore, while the thermoplastic resin is colored in gray, it indicates that the low-order titanium oxide maintains the oxygen absorbing ability.

  Therefore, if a transparent part that can visually recognize the discoloration of the oxygen absorbing layer is formed on either the inner surface of the container or the outer surface of the container, the color of the oxygen absorbing layer can immediately confirm the presence or absence of the oxygen absorbing ability. The effectiveness of the oxygen absorption function can be judged. If the periphery of the transparent part is printed in white with the same color as titanium dioxide or light gray when the oxygen absorption capacity is below a certain level, the print color and the degree of discoloration of the oxygen absorption layer are directly displayed. Since the comparison is possible, it is easier to determine the effectiveness of the oxygen absorption function. Furthermore, if several stages of printing portions from gray to white are provided as a guide for consumption of low-order titanium oxide, it is possible to more accurately determine the degree of reduction in oxygen absorption capacity.

  In addition, as a printing film, although the printing film generally used for a packaging container can be used, from a water-vapor-permeable viewpoint, an unstretched film (CPP, CPS, etc.) is preferable, and the water | moisture content mentioned above is mentioned. It is more desirable to add a transparent function.

  The above-mentioned “water-absorbing substance is either a hydrophilic organic compound or a water-absorbing inorganic substance” means a more specific definition of this “water-absorbing substance”. Organic compounds such as monoglycerite and sucrose fatty acid esters, polyethylene glycol, polypropylene glycol, nylon, polyacrylic acid (salt), polyvinyl acetate, polyvinyl alcohol, vinyl alcohol-acrylic acid (salt) ) Block copolymers and polymers such as modified polyethylene oxide are applicable. Moreover, clay, diatomaceous earth, hydrous calcium silicate, talc, etc. correspond to "inorganic substance which has a moisture adsorptivity". In addition, when the inorganic substance is filled, the water absorption can be further improved by using a hydrophilic organic compound as a dispersant or the like.

  The above-mentioned inner surface layer is referred to as “foamed layer” means that a layer obtained by foaming an inner surface layer made of a thermoplastic resin by foaming with a chemical foaming agent that does not generate water by reaction or foaming with a physical gas or the like. means. By foaming the inner surface layer in this manner, the substantial thickness of the resin that blocks moisture is reduced, and moisture easily reaches the oxygen absorbing layer. For the foaming of the inner surface layer, a known thermoplastic resin fine foaming method that is usually used can be used.

  The foamed inner surface layer includes those having a function of allowing moisture to permeate as long as necessary foaming is not inhibited. Moreover, the thing which mixed the hydrophilic organic compound and the inorganic substance which has water | moisture-content adsorption | suction each individually or in mixture of both is also contained. In addition, if you use a chemical foaming agent such as sodium bicarbonate that generates water by the reaction, the thermoformed container of the sheet material will exhibit an oxygen absorption function before use, and the function will deteriorate during original use, It is not preferable to use such a chemical foaming agent.

  By providing the sheet material itself constituting the container with an oxygen absorption layer, it is not necessary to attach a conventional oxygen absorbent-containing sachet or the like. By using a thermoplastic resin mixed with low-order titanium oxide as this oxygen-absorbing layer, there is no sensitivity to metal detectors and the like found in conventional oxygen-absorbing agents composed of iron-based components. Heating in the range can be performed safely. In addition, low-order titanium oxide can exhibit high safety without worrying about problems such as melting, dissolution, or combustion, which are found in organic compounds such as ascorbic acid-based oxygen absorbers.

  By placing the oxygen absorption layer inside the container, moisture contained in the food to be stored can penetrate into the oxygen absorption layer quickly and reliably, and the oxygen absorption function can be exhibited early, so that it is sealed. It becomes possible to rapidly absorb and remove oxygen in the container. On the other hand, by disposing an oxygen barrier layer outside the oxygen absorbing layer, it is possible to prevent oxygen in the outside air from passing through the outer surface layer and lowering the oxygen absorbing function of low-order titanium oxide contained in the oxygen absorbing layer. . Furthermore, by disposing an outer surface layer made of a thermoplastic resin outside the oxygen barrier layer, it is possible to prevent the oxygen barrier layer from absorbing moisture from the outside of the container and lowering the oxygen barrier function.

  Furthermore, by arranging an inner surface layer made of a thermoplastic resin inside the oxygen absorbing layer, a water-absorbing substance that absorbs moisture contained in food stored in the inner surface layer is mixed, or the inner surface layer is foamed. In other words, moisture contained in food or the like can be supplied to the oxygen absorbing layer more rapidly. In addition, seals when hiding the gray of low-order titanium oxide or sealing with a film or lid, such as by adding pigment to the inner surface layer, outer surface layer, or both, printing or attaching a printed film, etc. Can be improved.

  By setting the total thickness of the sheet material to 0.2 to 2 mm, it is possible to ensure basic physical properties as a container and to prevent excessive quality as a packaging container. In addition, by setting the thickness of the oxygen absorbing layer to 50 to 300 μm, it is possible to prevent pinholes and the like from being generated during sheet molding and appearance defects from occurring during this sheet material molding process. By setting the thickness of the oxygen barrier layer to 20 to 100 μm, it is possible to ensure the required oxygen barrier function and to prevent the sheet material from being deteriorated in moldability.

  By setting the content of the low-order titanium oxide to 3 to 15 wt% of the weight of the sheet material, it is possible to avoid that the low-order titanium oxide concentration of the oxygen absorption layer is extremely high, and the oxygen absorption layer is extremely Since it can avoid becoming thick, it can prevent that a pinhole etc. arise at the time of sheet | seat shaping | molding, or that an appearance defect arises at the time of sheet material shaping | molding process. Further, by setting the thickness of the inner surface layer to 50 to 300 μm, it is possible to ensure the gray concealment property of the oxygen absorption layer and prevent the moisture and water vapor permeability from being deteriorated.

  By mixing a water-absorbing substance that adds a moisture permeation function to the inner surface layer, the moisture contained in the food sealed in the container is brought into contact with the oxygen absorbing layer mixed with the low-order titanium oxide more quickly. Can do. Further, by mixing a water-absorbing substance that permeates 15 wt% or more of the weight of the low-order titanium oxide per day into the inner surface layer, it is possible to more reliably prevent oxidative deterioration of foods and the like. By providing a protective layer for preventing water permeation between the oxygen absorbing layer and the oxygen barrier layer, it is possible to prevent the oxygen barrier function of the oxygen barrier layer from being deteriorated.

  By attaching a printed film with the transparent part in part on the outer surface of either the inner surface layer or the outer surface layer, or both, low-order titanium oxide is converted from gray to white by absorption of oxygen through this transparent portion. Since the degree of discoloration can be visually confirmed, it is possible to immediately check the remaining oxygen absorption capacity. By making the inner surface layer a foam layer, the substantial thickness of the resin that blocks moisture can be reduced, and moisture can easily reach the oxygen absorption layer.

  By means of the technical means described above, the oxygen-absorbing container of the present invention can start absorbing oxygen in the container at an early stage, and can exhibit a unique effect of being excellent in oxygen absorbing function over a long period of time. Oxidation, alteration, decay, etc. of liquid or watery foods can be reliably prevented.

  Next, the best embodiment of the oxygen-absorbing container according to the present invention will be described with reference to FIGS. As shown in FIG. 1, an oxygen-absorbing container according to the present invention includes an oxygen-absorbing layer 1 in which low-order titanium oxide is mixed and dispersed in a thermoplastic resin, an oxygen barrier layer 3 having adhesive layers 2 on both sides, It is comprised from the sheet | seat material 10 containing the outer surface layer 4 which consists of a thermoplastic resin provided in the barrier layer side. Here, the oxygen absorption layer 1 is disposed inside the container, and the oxygen barrier layer 3 is disposed outside the container. Next, each layer will be described in detail.

  The oxygen absorption layer 1 is obtained by mixing and dispersing a low-order titanium oxide (manufactured by Marukatsu Sangyo Co., Ltd.), which is an oxygen absorbent, in a block polypropylene (manufactured by Nippon Polypro Co., Ltd., EC9) as a thermoplastic resin. The low-order titanium oxide uses a powder having an average particle size of 0.3 μm and is previously mixed with block polypropylene (manufactured by Nippon Polypro Co., Ltd., BC3F) in a twin-screw kneading extruder to obtain a master having a low-order titanium oxide content of 50 wt%. The one made in batch is used. Furthermore, when making a sheet material using a coextrusion multilayer sheet material production apparatus, a block polypropylene (manufactured by Nippon Polypro Co., EC9) is added to dilute this low-order titanium oxide-containing master batch, and the composition of the oxygen absorbing layer 1 Is a block polypropylene / low order titanium oxide (60/40 wt%) mixture.

  The oxygen barrier layer 3 uses an ethylene vinyl alcohol copolymer (manufactured by Kuraray, Eval EP-F101, ethylene content 32%, saponification degree 99%). The adhesive layers 2 and 2 disposed on both surfaces of the oxygen barrier layer 3 use maleic anhydride-modified polyolefin (manufactured by Mitsubishi Chemical, Modic P604V). The outer surface layer 4 made of a thermoplastic resin uses a block polypropylene (manufactured by Nippon Polypro, EC9) mixed with a white pigment (manufactured by Sumika Color, SPEM-7Y-1246).

  The total thickness of the sheet material 10 is 0.4 mm. The thicknesses of the oxygen absorbing layer 1, the adhesive layers 2 and 2, the oxygen barrier layer 3, and the outer surface layer 4 are 100 μm, 15 μm, 30 μm, and 240 μm, respectively.

  A sheet material 110 shown in FIG. 2 is obtained by providing an inner surface layer 105 made of a thermoplastic resin on the inner surface of the oxygen absorbing layer 1 of the sheet material 10 shown in FIG. For ease of understanding, each layer constituting the sheet material 110 and corresponding to each layer shown in FIG. 1 is a number obtained by adding 100 uniformly to the numbers shown in FIG. In the embodiment, the numbers are similarly added with 200 to the same). The inner surface layer 105 is the same as the outer surface layer 4 described above, and uses a block polypropylene (manufactured by Nippon Polypro, EC9) mixed with a white pigment (manufactured by Sumika Color Co., Ltd., SPEM-7Y-1246). Thickness. Therefore, the total thickness of the sheet material 110 is 0.5 mm.

  The sheet material 210 shown in FIG. 3 has the same layer structure as the sheet material 110 shown in FIG. 2, but the inner surface layer 205 is mixed with a water-absorbing substance. This water-absorbing material is a mixture of polyethylene glycol (manufactured by Sanyo Chemical Co., Ltd., PEG4000S) with 2 wt% of the weight of the inner surface layer 205.

  The sheet material 310 shown in FIG. 4 has the same layer structure as the sheet material 10 shown in FIG. 1, but a water-absorbing substance is mixed in the oxygen absorption layer 301. This water-absorbing substance is a mixture of polyethylene glycol (manufactured by Sanyo Chemical Co., Ltd., PEG 4000S) with 2 wt% of the weight of the oxygen absorbing layer 301 in the same manner as that mixed in the inner surface layer 205 described above.

  A sheet material 410 shown in FIG. 5 has the same layer structure as the sheet material 110 shown in FIG. 2, but a water-absorbing substance is mixed in the oxygen absorption layer 401. This water-absorbing material is a mixture of polyethylene glycol (manufactured by Sanyo Chemical Co., Ltd., PEG 4000S), 2 wt% of the weight of the oxygen absorbing layer 301, as described above.

  The sheet material 510 shown in FIG. 6 has the same layer structure as the sheet material 110 shown in FIG. 2, but a water absorbing material is mixed in both the inner surface layer 505 and the oxygen absorbing layer 501. . In this water-absorbing material, polyethylene glycol (manufactured by Sanyo Chemical Co., Ltd., PEG4000S) is mixed with 2 wt% of the weight of the inner surface layer 505 and the oxygen absorbing layer 501 in the same manner as described above.

  The sheet material 610 shown in FIG. 7 is newly provided with a protective layer 606 that prevents water permeation in the layer configuration of the sheet material 10 shown in FIG. The protective layer 606 is provided between the oxygen absorption layer 601 and the oxygen barrier layer 603, and uses a block polypropylene having a thickness of 50 μm (manufactured by Nippon Polypro, EC9).

  The sheet material 710 shown in FIG. 8 is newly provided with a protective layer 706 that prevents water permeation in the layer configuration of the sheet material 110 shown in FIG. The protective layer 706 is provided between the oxygen absorption layer 701 and the oxygen barrier layer 703, and uses the same 50 μm thick block polypropylene (EC9, manufactured by Nippon Polypro Co., Ltd.) as described above.

  A sheet material 810 shown in FIG. 9 has a printed film 807 attached to the layer structure of the sheet material 10 shown in FIG. From the viewpoint of obtaining water vapor permeability, the printing film 807 uses a non-stretched film (CPP, CPS, etc.) and leaves a transparent portion 872 such as letters on the surface in contact with the oxygen absorbing layer 801. Is given. In the printed film 807, similarly to the inner surface layer 205 shown in FIG. 3, a water-absorbing substance made of polyethylene glycol (manufactured by Sanyo Chemical Co., Ltd., PEG4000S) can be mixed with 2 wt% of the weight of the printed film.

  A sheet material 910 shown in FIG. 10 has a printing film 907 on which a transparent portion 972 such as letters is left on the surface in contact with the inner surface layer 905 in the layer configuration of the sheet material 110 shown in FIG. Is attached.

  Finally, one example of the above-described sheet material and method for producing the oxygen-absorbing container will be outlined. As shown in FIG. 12, the sheet material is composed of 6 layers and 7 layers of an inner surface layer, an oxygen absorbing layer, a protective layer, an oxygen barrier layer having an adhesive layer on both sides, and an outer surface layer. To manufacture. The material of each layer is the same as that described above.

  Now, as shown in FIG. 12, the inner surface layer (100 μm), the oxygen absorbing layer (100 μm), the protective layer (50 μm), the adhesive layer (15 μm), the oxygen barrier layer (30 μm), the adhesive layer (15 μm), which is the inside of the container, A sheet material consisting of 6 types and 7 layers having a total thickness of 500 μm consisting of an outer surface layer (190 μm) on the outside of the container is composed of a single screw extruder (first extruder) having a diameter of 90 mm, and two single screw extruders having a diameter of 65 mm ( The second and third extruders are manufactured by a coextrusion multilayer sheet material manufacturing apparatus including three single-screw extruders (fourth, fifth and sixth extruders) having a diameter of 50 mm.

  Then, 6 types and 7 layers of sheet material are thermoformed by a single vacuum forming machine to produce a flanged oxygen-absorbing container having a width of 120 mm, a length of 155 mm and a depth of 20 mm (volume 180 cc) as shown in FIG. To do. The oxygen-absorbing container accommodates food and the like, and closes the container by heating a transparent top seal film, which is a lid material, to a flange provided around the upper opening by heating or the like.

  Examples of the oxygen-absorbing container of the present invention and comparative examples of conventional oxygen-absorbing containers will be described below.

  12 shows a single-screw extruder having a diameter of 90 mm (first extruder), two single-screw extruders having a diameter of 65 mm (second and third extruders), and three single-screw extruders having a diameter of 50 mm (fourth to fourth). By co-extrusion multilayer sheet material production apparatus consisting of (sixth extruder), the resin shown in FIG. 12 is extruded at the same time, merged at the feed block part, made into a sheet material form from a T die, and cooled with a cooling roll, As shown in FIG. 2, an inner surface layer 105 (100 μm), an oxygen absorption layer 101 (100 μm), an adhesive layer 102 (15 μm), an oxygen barrier layer 103 (30 μm), an adhesive layer 102 (15 μm), and a container inside the container An oxygen-absorbing multi-layer sheet material 110 of 4 types and 6 layers having a total thickness of 500 μm composed of the outer surface layer 104 (240 μm) serving as the outer side was manufactured.

  The inner surface layer 105 and the outer surface layer 104 are mixed with block polypropylene (manufactured by Nippon Polypro, EC9) with a white pigment (manufactured by Sumika Color Co., Ltd., SPEM-7Y-1246), and the oxygen absorbing layer 101 is composed of block polypropylene (manufactured by Nippon Polypro). EC9) was mixed and dispersed with an oxygen absorbent composed of low-order titanium oxide (manufactured by Marukatsu Sangyo Co., Ltd.). The oxygen barrier layer 103 is an ethylene vinyl alcohol copolymer (Kuraray, Eval EP-F101), and the adhesive layers 102 and 102 are maleic anhydride-modified polyolefin (Mitsubishi Chemical, Modic P604V).

  The low-order titanium oxide, which is an oxygen-absorbing composition, is prepared by using powder having an average particle size of 0.3 μm and mixing with block polypropylene (Nihon Polypro, BC3F) in advance using a twin-screw kneading extruder. A masterbatch with a titanium content of 50 wt% was used. Furthermore, when making a sheet material using a coextrusion multilayer sheet material production apparatus, block polypropylene (manufactured by Nippon Polypro Co., EC9) is added to dilute this low-order titanium oxide-containing master batch, and the oxygen absorbing layer 101 The composition was a mixture of block polypropylene / low order titanium oxide (60/40 wt%). The four types and six layers of oxygen-absorbing multilayer sheet material 110 thus obtained are thermoformed by a single vacuum molding machine, and are 120 mm wide × 155 mm long × 20 mm deep (volume 180 cc) flanged oxygen absorbing container. Was made.

  5 cc of water was put into the oxygen-absorbing container manufactured as described above, and a film (thickness 120 μm) made of polyethylene terephthalate (PET) / aluminum (Al) / sealant was used, with a gas substitution rate of 99% (oxygen concentration 0). 21%) gas replacement packaging. The oxygen concentration in the container after standing in the room for 24 hours was 0.02%. The low-order titanium oxide contained in the container used for this test was 10.5 wt% from the ash. Moreover, although the oxygen absorbing container manufactured as described above was passed through a metal detector, it was not sensitive, and 150 cc of water was put into this container, and microwave heating was performed for 60 seconds until the water temperature reached 100 ° C. However, it could be heated safely without any particular problems. For the measurement of oxygen amount, Check Point O2 manufactured by PBI Dansentor, ID3-3000-PB manufactured by Ishida Co., Ltd. (search coil height 80 mm), and microwave oven EM-1605 manufactured by Sanyo Electric Co., Ltd. (1600w) was used.

  In order to measure the change over time in the oxygen permeation amount of the four-kind, six-layer oxygen-absorbing multilayer sheet material 110, a PET / Al / sealant film (thickness 120 μm) was attached to the inner surface layer 105 on the inside of the container with a sealing machine. Combined, 5 cc of water was added and completely sealed. Several types of this sample were prepared under the same conditions, stored at room temperature, and the change in oxygen permeation over time was measured. For the measurement of oxygen permeation amount, OX-TRAN (MODEL2 / 21ML) manufactured by MOCON was used. The measurement conditions were such that the temperature was 23 ° C., the humidity of the outer surface layer 104 serving as the outer side of the container was 65% RH, and the humidity of the inner surface layer 105 serving as the inner side of the container was 90% RH.

The test results of Example 1 are shown in FIG. The value of oxygen permeation before sealing was 0.26 cc / m ² · day · atm. After 3 days, the oxygen transmission rate decreased to 0.01 cc / m ² · day · atm, and it was found that this oxygen barrier function was sufficiently maintained for 6 months.

  As shown in FIG. 3, the inner surface layer 205 (100 μm), the oxygen absorbing layer 201 (100 μm), the adhesive layer 202 (15 μm), and the oxygen barrier layer 203 (30 μm), which are inside the container, are produced by the coextrusion multilayer sheet material manufacturing apparatus described above. ), Adhesive layer 202 (15 μm), and outer surface layer 204 (240 μm) on the outside of the container, a five-kind 6-layer oxygen-absorbing multilayer sheet material 210 having a total thickness of 500 μm was manufactured.

  The inner surface layer 205 which is the inner side of the container is a mixture of block polypropylene (manufactured by Nippon Polypro, EC9) and a white pigment (manufactured by Sumika Color Co., Ltd., SPEM-7Y-1246) and a water-absorbing substance (manufactured by Sanyo Chemical Industries, PEG4000S), As the outer surface layer 204 to be the outer side of the container, a block polypropylene (Nippon Polypro, EC9) mixed with a white pigment (manufactured by Sumika Color, SPEM-7Y-1246) was used. The oxygen absorbing layer 201 is a block polypropylene (manufactured by Nippon Polypro Co., Ltd., EC9) in which 30 wt% of low-order titanium oxide (manufactured by Marukatsu Sangyo) is mixed and dispersed. The oxygen barrier layer 203 is an ethylene vinyl alcohol copolymer (manufactured by Kuraray). , Eval EP-F101), and adhesive layers 202 and 202 were each made of maleic anhydride-modified polyolefin (Mitsubishi Chemical, Modic P604V). In the inner surface layer 205 which is the inner side of the container, a water absorbing material (PEG 4000S manufactured by Sanyo Chemical) was blended at a ratio of 2 wt% with respect to the inner surface layer.

  The five-kind, six-layer oxygen-absorbing multilayer sheet material 210 obtained as described above is thermoformed by a single-shot vacuum forming machine, and has a 120 mm width × 155 mm length × 20 mm depth (volume 180 cc) flanged oxygen absorbability. A container was made. This oxygen-absorbing container is filled with 5 cc of water, and a PET / Al / sealant film (thickness 120 μm) is used for gas replacement packaging with a gas replacement rate of 99% (oxygen concentration 0.21%) for 24 hours. The oxygen concentration in the container after being left indoors was measured. The value was 0.01% or less. The low-order titanium oxide contained in the container used for this test was 7.3 wt% from the ash. Moreover, although the oxygen absorbing container manufactured as described above was passed through a metal detector, it was not sensitive, and 150 cc of water was put into this container, and microwave heating was performed for 60 seconds until the water temperature reached 100 ° C. However, it could be heated safely without any particular problems.

In order to measure the change with time in the oxygen permeation amount of the five-kind / six-layer oxygen-absorbing multilayer sheet material 210, a film (thickness 120 μm) made of PET / Al / sealant is attached to the inner surface layer 205 which is the inner side of the container with a sealing machine Combined, 5 cc of water was added and completely sealed. This sample was stored at room temperature, and the change with time in the oxygen transmission rate was measured. The test result of Example 2 is shown in FIG. The value of oxygen permeation before sealing was 0.26 cc / m ² · day · atm. After one day, it was found that the oxygen permeation amount had already decreased to 0.01 cc / m ² · day · atm, and that this oxygen barrier function was sufficiently maintained for 6 months. From this, the water-absorbing substance blended in the inner surface layer 205 absorbs moisture as a trigger, and since the moisture permeated quickly into the oxygen absorption layer, it was judged that there was an effect of increasing the oxygen absorption start time. it can.

  The oxygen absorbing layer 201 of the oxygen-absorbing multilayer sheet material 210 of Example 2 is blended with 2 wt% of PEG4000S, which is a water-absorbing substance, to produce a five-kind, six-layer oxygen-absorbing multilayer sheet material 510 as shown in FIG. did. This oxygen-absorbing multilayer sheet material 510 was thermoformed by a single vacuum forming machine to produce a flanged packaging container having a width of 120 mm, a length of 155 mm, and a depth of 20 mm (volume: 180 cc). In the same manner as in Example 2, the oxygen concentration in the container after the gas replacement packaging container (gas replacement rate 99%, oxygen concentration 0.21%) was left in the room for 24 hours was measured. The value was 0.01% or less. The low-order titanium oxide contained in the container used for this test was 7.3 wt% from the ash. Moreover, although the oxygen absorbing container manufactured as described above was passed through a metal detector, it was not sensitive, and 150 cc of water was put into this container, and microwave heating was performed for 60 seconds until the water temperature reached 100 ° C. However, it could be heated safely without any particular problems.

The test result of Example 3 is shown in FIG. The value of oxygen permeation before sealing measured in the same manner as in Example 2 was 0.26 cc / m ² · day · atm. After one day, the oxygen permeation amount had already decreased to 0.01 cc / m ² · day · atm or less, and it was found that this oxygen barrier function was sufficiently maintained for 6 months. From this, the water-absorbing substance blended in the inner surface layer 505 absorbs moisture as a trigger, and the moisture permeates quickly into the oxygen-absorbing layer 501, and the water-absorbing substance further absorbs water in the oxygen-absorbing layer 501. Further, it can be determined that there was an effect of increasing the oxygen absorption start time.

  As shown in FIG. 8, the inner surface layer 705 (100 μm), the oxygen absorbing layer 701 (100 μm), the protective layer 706 (50 μm), and the adhesive layer as shown in FIG. A six-kind seven-layer oxygen-absorbing multilayer sheet material 710 having a total thickness of 500 μm, consisting of 702 (15 μm), an oxygen barrier layer 703 (30 μm), an adhesive layer 702 (15 μm), and an outer surface layer 704 (190 μm) on the outside of the container. Produced.

  The inner surface layer 705 that is the inner side of the container is a mixture of block polypropylene (manufactured by Nippon Polypro, EC9) with a white pigment (manufactured by Sumika Color, SPEM-7Y-1246) and a water-absorbing substance (manufactured by Sanyo Kasei, PEG 4000S), The outer surface layer 704 which is the outer side of the container is a mixture of block polypropylene (manufactured by Nippon Polypro, EC9) and a white pigment (manufactured by Sumika Color, SPEM-7Y-1246), and the oxygen absorbing layer 701 is block polypropylene (manufactured by Nippon Polypro). EC9) mixed with low-order titanium oxide (manufactured by Marukatsu Sangyo) and water-absorbing substance (manufactured by Sanyo Kasei, PEG4000S), protective layer 706 is block polypropylene (manufactured by Nippon Polypro, EC9), and oxygen barrier layer 703 is Ethylene vinyl alcohol copolymer (Kuraray, Eval EP-F101), Adhesive layer 702 of the oxygen barrier layer 703 Te is maleic anhydride-modified polyolefin (manufactured by Mitsubishi Chemical Corporation, Modic P604V) was used.

  The six-kind seven-layer oxygen-absorbing multilayer sheet material 710 obtained as described above is thermoformed with a single vacuum molding machine, and a flanged packaging container having a width of 120 mm, a length of 155 mm, and a depth of 20 mm (volume 180 cc) is obtained. Produced.

  In the same manner as in Example 2, the oxygen concentration in the container after the gas replacement packaging container (gas replacement rate 98%, oxygen concentration 0.42%) was left indoors for 24 hours was measured. The value was 0.01% or less. The low-order titanium oxide contained in the container used for this test was 7.4 wt% from the ash. Moreover, although the oxygen absorbing container manufactured as described above was passed through a metal detector, it was not sensitive, and 150 cc of water was put into this container, and microwave heating was performed for 60 seconds until the water temperature reached 100 ° C. However, it could be heated safely without any particular problems.

The test result of Example 4 is shown in FIG. The value of oxygen permeation before sealing measured in the same manner as in Example 2 was 0.26 cc / m ² · day · atm. After one day, it was found that the oxygen permeation amount had already decreased to 0.01 cc / m ² · day · atm or less, and that the oxygen barrier function did not decrease much after 6 months. From this, the water-absorbing substance blended in the inner surface layer 705 absorbs moisture serving as a trigger, and the moisture that has permeated the oxygen absorbing layer 701 quickly is prevented from transferring to the oxygen barrier layer 703. It can be determined that oxygen entry from the outside is reduced and the oxygen absorption capacity is maintained for a long time.

  A co-extrusion multilayer sheet material manufacturing apparatus similar to that described above is used, as shown in FIG. 2, an inner surface layer 105 (100 μm), an oxygen absorbing layer 101 (100 μm), an adhesive layer 102 (15 μm), and an oxygen barrier as shown in FIG. A five-kind, six-layer oxygen-absorbing multilayer sheet material 110 having a total thickness of 500 μm composed of a layer 103 (30 μm), an adhesive layer 102 (15 μm), and an outer surface layer 104 (240 μm) on the outside of the container was manufactured. Here, as the inner surface layer 105 which is the inner side of the container, a block polypropylene (manufactured by Nippon Polypro Co., Ltd., FB3312) which is twice foamed with carbon dioxide gas is used.

  The outer surface layer 104 on the outside of the container is a mixture of block polypropylene (Nippon Polypro, EC9) and a white pigment (manufactured by Sumika Color, SPEM-7Y-1246), and the oxygen absorption layer 101 is block polypropylene (manufactured by Nippon Polypro). EC9) mixed with low-order titanium oxide 40 wt% (manufactured by Marukatsu Sangyo), oxygen barrier layer 103 is an ethylene vinyl alcohol copolymer (Kuraray, Eval EP-F101), and adhesive layers 102 and 102 are , Maleic anhydride modified polyolefin (Mitsubishi Chemical, Modic P604V) is used.

  The five-kind six-layer oxygen-absorbing multilayer sheet material 110 obtained as described above is thermoformed with a single-shot vacuum forming machine, and has a width of 120 mm, a length of 155 mm, and a depth of 20 mm (volume 180 cc) with a flange. A sex container was made. Then, in the same manner as in Example 1, the oxygen concentration in the container after the gas replacement packaging container (gas replacement rate 98%, oxygen concentration 0.42%) was left indoors for 24 hours was measured. The value was 0.01%. The low-order titanium oxide contained in the container used for this test was 11.5 wt% from the ash. Moreover, although the oxygen absorbing container manufactured as described above was passed through a metal detector, it was not sensitive, and 150 cc of water was put into this container, and microwave heating was performed for 60 seconds until the water temperature reached 100 ° C. However, it could be heated safely without any particular problems.

The test result of Example 5 is shown in FIG. The value of oxygen permeation before sealing measured in the same manner as in Example 2 was 0.26 cc / m ² · day · atm. After one day, it was found that the oxygen permeation amount had already decreased to 0.01 cc / m ² · day · atm, and that this oxygen barrier function was sufficiently maintained for 6 months. From this, it can be determined that the foaming of the inner surface layer 105 has the effect of accelerating the oxygen absorption start time because moisture serving as a trigger permeated the oxygen absorption layer 101 quickly.

  As shown in Comparative Example 1 in FIG. 11, the sheet material 1010 (inner surface layer 1015, adhesive layer 1012, adhesive layer 1012, which has the same configuration as that of Example 1 except that the oxygen absorption layer containing low-order titanium oxide was not provided. An oxygen barrier layer 1013, an adhesive layer 1012, and an outer surface layer 1014) were produced, and this sheet material was thermoformed to produce a flanged oxygen absorbing container. 5 cc of water was put into this packaging container, and the oxygen concentration in the container after 24 hours of the gas replacement packaging container (gas replacement rate 99%, oxygen concentration 0.21%) was measured in the same manner as in Example 1. The value was 0.23%.

The test results of Comparative Example 1 are shown in FIG. In the same manner as in Example 1, the oxygen transmission amount of the sheet material 1010 was measured. The value of oxygen permeation before sealing was 0.26 cc / m ² · day · atm. It was found that the oxygen permeation amount increased to 0.36 cc / m ² · day · atm after 7 days due to moisture absorption of the oxygen barrier layer 1013, and the oxygen permeation amount further increased after 6 months. In other words, if there is no oxygen absorbing layer, oxygen is not absorbed but permeates, and conversely, if an oxygen absorbing layer as shown in Examples 1 to 5 is provided, oxygen is absorbed after one day, and the amount of permeation is greatly increased. It was confirmed that it decreased.

  As shown in Comparative Example 2 in FIG. 2, a sheet material 110 having the same configuration as that of Example 1 was produced. Except that block polypropylene (EC9, manufactured by Nippon Polypro Co., Ltd.) was used for the oxygen barrier layer 103 in place of the ethylene vinyl alcohol copolymer, this was performed in the same manner as in Example 1, and the oxygen absorbing property with a flange made of the sheet material 110 was used. A container was made. 5 cc of water was put into this container, and the oxygen permeation amount in the container after 24 hours of the gas replacement packaging container (gas replacement rate 99%, oxygen concentration 0.21%) was measured in the same manner as in Example 1. The value was 1.40%. The low-order titanium oxide contained in the container was 10.5 wt% from the ash.

  As in Example 1, as a result of measuring the oxygen permeation amount of the sheet material, as shown in FIG. 14, the oxygen penetration amount from the outside was large.

  From the above test results, Examples 1 to 5 can suppress the oxygen permeation amount to be lower than those of Comparative Examples 1 and 2. In particular, in an environment where moisture exists, the oxygen absorbing layer is arranged to be remarkably effective. It was recognized that Furthermore, by blending a water-absorbing substance in the inner surface layer and oxygen absorbing layer located inside the container, the oxygen absorption start time can be greatly shortened, and oxidation of the contents can be prevented from the initial stage. It was confirmed that it was possible. Further, by providing a protective layer (water permeation preventive layer) that prevents the influence of moisture by the water-absorbing substance between the oxygen absorbing layer and the oxygen barrier layer, moisture absorption of the oxygen barrier layer can be prevented, and the outside of the container It was confirmed that an excellent effect was also obtained in preventing oxygen permeation from.

  In addition, although the said Examples 1-5 and the comparative examples 1 and 2 demonstrated the oxygen absorptive multilayer sheet material before shape | molding in the oxygen absorptive container of this invention, from this Example result, this sheet | seat material is vacuumed. It is clear that the same effect can be obtained for an oxygen-absorbing container that has been processed by molding, hot plate molding, or the like.

  The oxygen-absorbing container according to the present invention is suitable not only for food packaging containers but also for packaging containers for various products such as office supplies, mechanical / electrical parts, and household products. is there.

It is a partial expanded sectional view of the sheet material used for an oxygen absorptive container. It is a partially expanded sectional view of the other sheet material used for an oxygen absorptive container. It is a partially expanded sectional view of the other sheet material used for an oxygen absorptive container. It is a partially expanded sectional view of the other sheet material used for an oxygen absorptive container. It is a partially expanded sectional view of the other sheet material used for an oxygen absorptive container. It is a partially expanded sectional view of the other sheet material used for an oxygen absorptive container. It is a partially expanded sectional view of the other sheet material used for an oxygen absorptive container. It is a partially expanded sectional view of the other sheet material used for an oxygen absorptive container. It is a partially expanded sectional view of the other sheet material used for an oxygen absorptive container. It is a partially expanded sectional view of the other sheet material used for an oxygen absorptive container. It is a partially expanded sectional view of the sheet material used for the container made into the comparative example. It is the table | surface explaining the structure and manufacturing means of the sheet | seat material used in the Example. It is a perspective view of an oxygen absorptive container. It is a table | surface which shows the structure of the sheet material used for the Example and the comparative example, and the test result about oxygen permeation amount.

Explanation of symbols

1-901 Oxygen absorbing layer 2-902, 1012 Adhesive layer 3-903, 1013 Oxygen barrier layer 4-904, 1014 Outer surface layer 105, 205, 405, 505, 705, 905, 1015 Inner surface layer 606, 706 Protective layer (water permeable) Prevention layer)
807, 907 Print film 871, 971 Print 872, 972 Characters (transparent part)
10-910, 1010 sheet material

Claims (8)

A container formed by thermoforming a sheet material,
The sheet material includes an oxygen absorption layer in which low-order titanium oxide is mixed in a thermoplastic resin, an oxygen barrier layer in which an adhesive layer is disposed on both surfaces, and an outer surface layer made of a thermoplastic resin, and from the inside of the container. Ri Thea arranged in this order,
The total thickness of the sheet material is 0.2 to 2 mm, the thickness of the oxygen absorption layer is 50 to 300 μm, and the thickness of the oxygen barrier layer is 20 to 100 μm,
The low-order titanium oxide in the oxygen absorption layer has a crystal structure represented by the general formula TiO _2-x (x represents a real number of 0.1 to 0.5),
The content of the low-order titanium oxide is 3 to 15 wt% of the weight of the sheet material,
The oxygen absorbing layer is mixed with a water-absorbing substance that adds a moisture absorbing function,
The oxygen-absorbing layer according to claim 1, wherein the oxygen-absorbing layer absorbs at least 15 wt% of water of the weight of the low-order titanium oxide contained in the oxygen-absorbing layer per day . A container formed by thermoforming a sheet material,
The sheet material includes an inner surface layer made of a thermoplastic resin, an oxygen absorbing layer in which low-order titanium oxide is mixed with the thermoplastic resin, an oxygen barrier layer in which an adhesive layer is disposed on both sides, and an outer surface layer made of a thermoplastic resin. includes, and Ri tare arranged in this order from the inside of the container,
The total thickness of the sheet material is 0.2 to 2 mm, the thickness of the inner surface layer is 50 to 300 μm, the thickness of the oxygen absorbing layer is 50 to 300 μm, and the thickness of the oxygen barrier layer is 20 to 100 μm,
The low-order titanium oxide in the oxygen absorption layer has a crystal structure represented by the general formula TiO _2-x (x represents a real number of 0.1 to 0.5),
The content of the above Symbol lower titanium oxide is 3 to 15% of the weight of the sheet material,
The inner surface layer is mixed with a water-absorbing substance that adds a moisture permeation function,
The inner surface layer permeates moisture of at least 15 wt% of the weight of the low-order titanium oxide contained in the oxygen absorption layer per day . A container formed by thermoforming a sheet material,
The sheet material includes an inner surface layer made of a thermoplastic resin, an oxygen absorbing layer in which low-order titanium oxide is mixed with the thermoplastic resin, an oxygen barrier layer in which an adhesive layer is disposed on both sides, and an outer surface layer made of a thermoplastic resin. And arranged in this order from the inside of the container,
The total thickness of the sheet material is 0.2 to 2 mm, the thickness of the inner surface layer is 50 to 300 μm, the thickness of the oxygen absorbing layer is 50 to 300 μm, and the thickness of the oxygen barrier layer is 20 to 100 μm,
The low-order titanium oxide in the oxygen absorption layer has a crystal structure represented by the general formula TiO _2-x (x represents a real number of 0.1 to 0.5),
The content of the above Symbol lower titanium oxide is 3 to 15% of the weight of the sheet material,
The oxygen absorbing layer is mixed with a water absorbing material that adds a water absorbing function,
The oxygen absorption layer absorbs water of at least 15 wt% of the weight of the low-order titanium oxide contained in the oxygen absorption layer per day.
An oxygen-absorbing container characterized by that . The oxygen absorbing layer is mixed with a water absorbing material that adds a water absorbing function,
The oxygen absorption layer absorbs water of at least 15 wt% of the weight of the low-order titanium oxide contained in the oxygen absorption layer per day.
The oxygen-absorbing container according to claim 2 . The oxygen-absorbing container according to any one of claims 1 to 4, wherein a protective layer for preventing water permeation is provided between the oxygen-absorbing layer and the oxygen-barrier layer. The oxygen-absorbing container according to any one of claims 1 to 5, wherein a printed film with a transparent portion remaining in a part thereof is attached to an outer surface of either the outer surface layer or the inner surface layer. The oxygen-absorbing container according to any one of claims 1 to 6, wherein the water-absorbing substance is either a hydrophilic organic compound or an inorganic substance having moisture adsorption properties. The oxygen-absorbing container according to any one of claims 2 to 4, wherein the inner surface layer is a foamed layer.

Images