JP2001031130A - Multi-layer oxygen scavenging packing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain excellent liq. resistance and oxygen absorbing power by forming a deoxygenation packing from a deoxygenation layer consisting of a thermoplastic resin contg. a non-air permeable layer and a deoxygenation compsn. and being continuously porous and a hiding layer consisting of a non- porous thermoplastic resin exhibiting an oxygen permeability with a specified value. SOLUTION: When opening parts of various containers such as bottles and plastic bottles are hermetically sealed, a deoxygenation packing used for a cap is formed of a non-air permeable layer 14, a deoxygenation layer (a layer A) 13 consisting of a thermoplastic resin contg. a deoxygenation compsn. and made continuously porous by drawing, a hiding layer (a layer B) consisting of a thermoplastic resin with an oxygen permeability of 1×10-11-6×10-9 [cm3/ cm2.sec.Pa] and contg. a non-porous and hardly water-soluble filler and a non-porous layer 11. As the deoxygenation ingredient used for the deoxygenation layer, e.g. an ingredient such as a metal powder such as iron powders, aluminum powders and silicon powders, inorg. salts such as ferrous salts and ascorbic acid and its salts is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a lid and a cap having a deoxidizing function used for sealing the mouth of a bottle, a plastic bottle and other various containers. Container lid of the present invention is excellent in liquid resistance, juice, liquor, wine, beer,
Used to seal storage containers containing other liquid beverages, salted foods, boiled foods, jams, marmalades, salmon flakes, other foods including high moisture foods, or pharmaceuticals,
Used to prevent quality deterioration due to oxygen.

[0002]

2. Description of the Related Art Conventionally, beverages which are susceptible to oxygen deterioration,
It has been pointed out that foods, pharmaceuticals, and the like are deteriorated in quality during storage due to oxygen in the container. As means for solving this problem, vacuum packing, nitrogen replacement, and the like have been used, but it is difficult to completely remove oxygen from the container, and this is not satisfactory in terms of the quality maintaining effect. On the other hand, the use of oxygen scavengers with excellent oxygen removal effects has been attempted,
There was a problem with the loadability coming from the pouch shape.

[0003] Also, various methods have been proposed for incorporating an oxygen scavenger into the lid and cap of a container. JP-A-57-97
No. 46 proposes a packing containing a deoxidizer, but since a powdered deoxidizer is used,
It is easily contaminated during manufacturing, has hygiene problems, and has a high oxygen permeability in the packing, so a large amount of oxygen enters the container during long-term storage, and the oxygen absorber in the container increases due to the inability to absorb the oxygen absorber. There was a disadvantage.

Japanese Utility Model Laid-Open Publication No. 1-177165 proposes a packing material for a container having a structure of foam / impermeable film / oxygen-absorbing film / deodorizing film / air-permeable film.

[0005] Japanese Patent Application Laid-Open No. 7-137761 proposes a packing material for a container having a structure of foam / impermeable film / sheet oxygen absorber / air permeable sheet.

Japanese Patent Application Laid-Open No. 9-183453 proposes a lid packing comprising a sheet-like packing material / an air-impermeable layer / an oxygen-absorbing resin layer obtained by kneading an oxygen-absorbing composition into a resin / a resin layer. Have been. In this method, there is no problem in liquid resistance because a resin layer having good oxygen permeability is used for the layer in contact with the contents. However, when the deoxidizing composition is kneaded into the resin, the oxygen absorption rate is reduced, and there is a problem that the oxygen absorption rate is not sufficient in a field requiring a high oxygen absorption rate at a low temperature.

[0007]

As described above, the conventional oxygen-absorbing packing for a container lid for sealing the container opening has a low oxygen absorption rate and is not practical, or has a poor liquid resistance to liquid applications. It was not always satisfactory, with limitations. The object of the present invention is to solve the above-mentioned problems of the prior art, and to achieve excellent liquid resistance, safety and health,
Moreover, it is an object of the present invention to provide a deoxygenated packing having a high oxygen absorption capacity.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the problems of the prior art, and as a result, have completed the present invention. That is, the present invention provides a non-breathable layer, a deoxidized layer (A layer) made of a thermoplastic resin containing a deoxidized composition and made continuous and porous by stretching, and an oxygen permeability of 1 × 10 ^−11.
The present invention provides a deoxidizing packing having a layer structure of a concealing layer (layer B) made of a nonporous thermoplastic resin having a thickness of up to 6 × 10 ⁻⁹ [cm ³ / cm ² · sec · Pa]. The layer A may further contain a poorly water-soluble filler, if necessary. Furthermore, A
Containing a poorly water-soluble filler disposed between the layer and the B layer,
The concealing layer (layer C) which has been made continuous porous by stretching is disposed for the purpose of concealing layer A.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the air-impermeable layer comprises
In order to have a good barrier property and to exhibit an excellent deoxygenation function when used for sealing a container, it must be substantially non-breathable. Specifically, the oxygen permeability is 500 cc / m ²
-Day.atm (23 ° C, 100% RH) or less, more preferably 100 cc / m ² · day · atm (23 ° C, 100% RH) or less is suitably used.

Examples of the plastic film used for the air-impermeable layer include polyethylene terephthalate, polyamides, polyvinylidene chloride, ethylene vinyl alcohol copolymer, polyvinyl alcohol, polyvinylidene chloride coated film, aluminum-deposited film, aluminum foil, and silica-deposited film. Film, other film alone or for packing and laminating adhesive, the above film and polyethylene,
Various coextruded films such as EVA, ionomer, EAA, EMAA, EEA, a composite film obtained by laminating other polyolefin resin films, triple nylon (manufactured by Ozaki Light Chemical Co., Ltd.), varilon (manufactured by Asahi Kasei Corporation) and the like are also preferably used. . The thickness of the film is selected depending on oxygen permeability, processability, etc., and is used in the range of 10 to 100 μm.

Various compositions are known as the deoxidizing component used in the deoxidizing layer. Among them, metal powders such as iron powder, aluminum powder and silicon powder, inorganic salts such as ferrous salt, ascorbic acid And salts thereof, alcohols such as catechol and glycerin, or phenols as a main agent are preferred. This base material is used as a particulate material together with other components as an oxygen scavenger composition. Among them, in particular, a metal powder having a metal halide adhered to the surface by a method disclosed in Japanese Patent No. 1088514, a metal powder and a metal halide, and if necessary, other additives using a binder or the like. Granulated particles are preferably used.

The particle size of the oxygen-absorbing composition is not particularly limited as long as the maximum particle size is less than the thickness of the oxygen-absorbing layer described later. Finer particles are desirable in that they do not damage (no penetration), and the maximum particle size is 200 μm or less, more preferably 10 μm or less.
0 [μm] or less. The mixing ratio of the oxygen-absorbing composition in the oxygen-absorbing layer is preferably from 10 to 80% by weight,
More preferably, it is 70% by weight. If the blending ratio is too low, the oxygen absorption performance will decrease, and if it is too high, the processability will decrease.

[0013] If necessary, a porosification aid may be added to the deoxidizing layer. The porosity assisting agent is for assisting the porosity of the deoxygenation layer, and the use of the porosity auxiliary agent can reduce the amount of the expensive deoxygenation component added. The porosification aid added to the deoxygenation layer is not particularly limited as long as it is a filler that is hardly soluble (including insoluble) in water, but it is preferable to use an inorganic filler having an appropriate hardness for making the porous body. . Such examples include silica, alumina, diatomaceous earth, titania, barium sulfate, and the like, and it is most preferable to use ground silica in view of hardness, handling, and price. There is no particular limitation on the particle size of the filler as long as it is equal to or less than the thickness of the deoxidized layer.

In the oxygen-absorbing layer, besides the oxygen-absorbing composition and the porosification aid, if necessary, a coloring agent such as an organic dye, an inorganic dye or a pigment, and a defoaming agent such as an alkaline earth metal oxide. ,
Dispersants such as silanes and titanates, water-absorbing agents such as polyacrylic compounds, fillers such as clay, mica, silica and starch, and gas adsorbents such as zeolite and activated carbon can be added.

If necessary, a concealing layer made of a continuous porous resin containing a poorly water-soluble filler is provided between the oxygen-free layer and the non-porous layer. The poorly water-soluble filler to be used can be considered in the same manner as the porogen of the deoxidizing layer, but in this case, since the concealing layer is between the nonporous layer and the deoxidizing layer, the particle size of the filler Is preferably as small as possible so as not to penetrate the non-porous layer. Further, as the hiding agent, a coloring agent as exemplified in the deoxidizing layer additive can be used, and other additives can be used similarly to the deoxidizing layer. However, like the porous filler, the particle size is preferably as small as possible so as not to penetrate the non-porous layer. In addition, some additives function as a porogen, and there is no restriction on making a porous material with such an additive.

As the resin used for the deoxidizing layer and the concealing layer, since both layers are continuously porous, the oxygen permeability of the resin itself does not matter, and deoxidizing components such as iron powder and poorly water-soluble There is no particular limitation as long as the filler can be easily mixed and dispersed. Rather, it may be selected in consideration of good compatibility with the non-porous layer, the operating temperature range of the deoxidized multilayer film and sheet, and the like, and generally follows the examples of the resin of the non-porous layer described below. .

The resin constituting the nonporous layer may be not only a polymer polymerized from a single monomer species but also a mixture of various copolymers and resins as long as it is a nonporous material. Further, as long as the oxygen permeability of the entire nonporous layer satisfies the above range, the nonporous layer itself may be composed of a plurality of layers. Further, there is no particular limitation when the same resin as the non-porous layer is used as the resin serving as the matrix component of the other layers, but when a different resin is used, the resin and the resin constituting the non-porous layer are used. Affinity is important. That is, although it is related to the lamination method described below, it is necessary that the resin of the nonporous layer and the resin used for the matrix component of the other layer have compatibility, especially when no adhesive or the like is used. is there. Here, the proof of the compatibility does not need to be strictly thermodynamically required. For example, it is only required that both can be heat-sealed.

Specific examples of the resin include homopolymers and copolymers of olefins such as ethylene, propylene, 1-butene and 4-methyl-1-pentene, ethylene-vinyl acetate copolymer, polybutadiene, Polyisoprene, styrene-butadiene copolymer and its hydrogenated product,
There are various silicone resins, and the like, and modified products, grafts, and mixtures thereof may also be used. And
The maximum value of the thickness of the nonporous layer is determined by the required performance of the object to be deoxidized represented by the oxygen permeability and the oxygen permeability coefficient of the resin. However, if it can be manufactured stably so that pinholes do not occur, and if it is certain that pinholes and tears will not occur even in contact with the contents in normal use, it is as thin as possible than the maximum value It is desirable that the thickness is generally about 10 to 50 [μm].

Various methods can be used for producing the oxygen-absorbing packing of the present invention. For example, a non-air-permeable layer, an oxygen-absorbing layer, a poorly water-soluble filler layer, and a non-porous layer can be co-extruded or extruded. After being formed by lamination, it is stretched at least uniaxially to make the deoxygenation layer and the poorly water-soluble filler layer porous to produce a multilayer film, which is directly attached to the container lid or attached to an elastic material and attached to the container lid. It can be manufactured by the following. Alternatively, layers other than the non-permeable layer may be laminated, and the non-permeable layer may be attached after stretching. That is, a preferred embodiment of the present invention is a deoxidizing packing in which the layer A and / or the layer C is a resin layer that is continuously made porous by stretching. The deoxidizing packing of the present invention is preferably used by disposing the air-impermeable layer side to a packing material and disposing it on the back side of the container lid cap. There is no limitation on the shape of the container lid packing, but a disk shape is preferred.

[0020]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Example 1 As an oxygen scavenger, an iron powder having a maximum particle size of about 50 μm was sprayed with an aqueous solution of calcium chloride, dried by heating and coated (hereinafter, simply referred to as iron powder). The ratio is 2 parts by weight of calcium chloride to 100 parts by weight of iron powder. This deoxygenated component is converted to polypropylene (FW3E, manufactured by Nippon Polychem Co., Ltd.)
The product name is polypropylene, but in fact other α
-Copolymer containing a small amount of olefin, melt flow rate 7.0 g / 10 min) and pulverized silica (CRYSTALITE VXS2, manufactured by Tatsumori Co., Ltd., average particle size 5 μm) as a porosification aid, and iron powder: pulverized The mixture was kneaded with a 30 mm diameter twin screw extruder at a weight ratio of silica: polypropylene = 5: 1: 4, cooled with a net belt with a blower, and then passed through a pelletizer to prepare pellets containing an oxygen scavenger composition.

As pellets for the non-porous layer, polypropylene (same as above), ethylene-hydrogenated butadiene copolymer (DYNARON 6200P, manufactured by JSR Co., Ltd.) and titanium oxide as a white pigment (Sakai Chemical Industry Co., Ltd.) Co., Ltd., SR-1)
Was prepared in a weight ratio of polypropylene: ethylene-hydrogenated butadiene copolymer: titanium oxide = 45: 45: 10 in the same manner as the pellets containing the oxygen scavenger composition.

Next, a two-layer, two-layer co-extrusion film apparatus comprising first and second extruders, a feed block, a T-die, a cooling roll, and a film take-off machine is used. The non-porous layer pellets were used for the extruder No. 2 and both were extruded from the respective extruders to obtain a two-layer film. This two-layer film is stretched in the longitudinal direction by a uniaxial stretching machine.
The film was stretched twice to make the deoxidized layer porous. Thereafter, a laminated film of polypropylene and aluminum foil was adhered with an adhesive as a non-permeable layer to complete a multilayer film. This multilayer film was affixed to a 28 mm-diameter elastic packing material for a lid, and loaded on the back surface of a plastic cap for a PET bottle to obtain a cap having a deoxidizing function.

A 500 cc PET bottle was filled with natural juice orange juice in an amount such that the head space became 10 cc and sealed with the cap. The PET bottle containing the orange juice was stored at 25 ° C. under irradiation with a fluorescent lamp (lightness: 2000 lux), and the change in oxygen concentration was measured by gas chromatography. The changing situation was tested. The results are shown in Table 1.

Example 2 The deoxygenation layer was the same as in Example 1, and the nonporous layer was polypropylene: ethylene-hydrogenated butadiene copolymer = 50: 5.
0, in addition, after adding a poorly water-soluble filler layer and a non-breathable layer prepared as a mixed pellet in a weight ratio of polypropylene: crushed silica: titanium oxide = 45: 45: 10, and coextruding four types and four layers, Then, the film was stretched 6 times in the uniaxial direction. Thereafter, a cap was formed in the same manner as in Example 1, and a test was performed. The results are shown in Table 1 together with the results of Example 1.

Comparative Example 1 The film used in Example 1 was directly attached to a packing material without being stretched, and an experiment similar to that of the example was performed. The results were combined with the results of the examples 1 and 2, The results are shown in Table 1.

Comparative Example 2 The same experiment as in the example was performed by attaching only the packing material to the cap without attaching the deoxidizing film, and the results were combined with the results of the examples 1, 2, and 1 hand,
The results are shown in Table 1.

[0027]

[Table 1]

[0028]

The deoxygenated packing of the present invention is made of a specific material and a specific composition, so that it has excellent liquid resistance, safety and hygiene, high oxygen absorption performance, and sealing. It has excellent oxygen-absorbing performance for long-term storage due to its excellent properties, and exhibits a quality maintaining effect. According to the present invention, juice, beer, alcohol, wine, other liquid beverages, salted food, boiled food, jam, marmalade, salmon flakes, various foods including other high moisture foods, or deoxygenated storage containing pharmaceuticals etc. When used for a container lid, it exerts an excellent effect over a long period of time on maintaining the quality of these articles, which are liable to deteriorate in quality due to oxygen and liable to decay or deteriorate due to propagation of microorganisms.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a deoxygenating packing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Non-porous layer 12 Concealment layer 13 Deoxygenation layer 14 Non-breathable layer 20 Packing material

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 3E084 AA04 AA24 AA32 AB01 AB02 AB06 AB10 HA02 HC07 HD01 JA04 4F100 AA06H AA20H AA21H AB02H AB10 AB33 AK01B AK01C AK01D AK07 AK29 AK29J AK64 BA10 BA03 BA03 BA03 DE01H DJ06B DJ06D GB18 JB03 JB07 JB09B JB16B JB16C JB16D JD02A JL00 JN02C JN02D

Claims (3)

[Claims] 1. An oxygen-impermeable layer, an oxygen-absorbing layer (layer A) comprising a thermoplastic resin containing a deoxidizing composition and made continuous by stretching, and an oxygen permeability of 1 × 10 ^{−11 to} 6 ×. 10 ^-9 [c
m ³ / cm ² · sec · Pa], a deoxidizing packing having a multilayer structure of a concealing layer (layer B) made of a nonporous thermoplastic resin. 2. The oxygen-absorbing packing according to claim 1, wherein the layer A further contains a poorly water-soluble filler. 3. The oxygen-absorbing property according to claim 1, further comprising a concealing layer (C layer) containing a poorly water-soluble filler and being continuously made porous by stretching between the A layer and the B layer. packing.