JP3114896B2 - Container lid with excellent long-term storage - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lid for a bottle or other container, and more particularly, to a device for sealing a container to prevent oxygen permeation through a sealing portion of the lid. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container lid having excellent long-term storage characteristics, which can quickly remove oxygen from a head space or the like in a container.

[0002]

2. Description of the Related Art In the manufacture of bottles, there is always a space called a head space above a bottle. Oxygen remains in the headspace after stoppering, and the oxygen oxidizes and degrades the contents, further causing the growth of mold, yeast, bacteria and the like. In order to remove oxygen in the headspace, steam or nitrogen gas is blown into the bottle filled with the contents to replace the air in the headspace with these gases,
It is generally known to then cap the lid. Gas replacement is excellent in that it removes some oxygen from the headspace.

[0003] However, performing gas replacement requires a large amount of cost for gas charges and facilities. Further, it is difficult to completely remove oxygen in the headspace even by gas replacement, and even more difficult to remove dissolved oxygen in the contents. Actually, it is known that in canned or bottled fruits, fruit juices, vegetables and the like, the contents are altered by residual oxygen.

On the other hand, in order to prevent the influence of residual oxygen in a container, a device using a deoxidizer for a lid or the like is already known. For example, there is a container in which a container lid is composed of a metal shell and a packing or a liner provided inside the shell, and a resin such as the packing is mixed with an oxygen scavenger. The oxygen scavenger in the container lid liner or packing eventually absorbs and removes residual oxygen in the headspace or contents.

[0005]

However, what has the greatest effect on the flavor of the contents of canned or bottled products is that the oxygen present in the container and the long-term contents of the container during heat sterilization such as retort sterilization have the greatest effect. It is considered to be oxygen permeating into the container through the liner or packing during storage. In this sense, the known oxygen-absorbing agent-containing liner has a capability of removing residual oxygen in the container to a range that does not affect the flavor or the like immediately after stoppering in sterilization or sterilization of the contents and storage of the long-term contents. It was not yet satisfactory.

Accordingly, it is an object of the present invention to quickly absorb oxygen present in a container during heat sterilization such as retort sterilization, and to capture oxygen permeating into the container through a liner or packing. An object of the present invention is to provide a container lid capable of improving the flavor (flavor) retention of the contents of a sealed container such as a filled product. Another object of the present invention is to provide a container lid in which the above advantages are achieved without impairing the sealing performance of the liner or packing.

[0007]

According to the present invention, in a container lid comprising a container lid shell and an oxygen-absorbing agent-containing resin layer provided on the inner surface side of the shell top plate portion, the resin layer is From a sealed portion containing a first oxygen absorber that reacts with oxygen flowing into the package from outside the package through the resin layer, and a central portion containing a second oxygen absorber that reacts with residual oxygen in the package. Compared with the unit weight of the oxygen-absorbing agent-containing resin composition, the center portion has an excellent content long-term storage property characterized by having a larger oxygen absorption than the oxygen absorption of the sealed portion. A container lid is provided.

[0008]

The container lid according to the present invention comprises a container lid shell and a resin layer containing an oxygen scavenger provided on the inner surface side of the shell top plate. This resin layer is packaged from outside the package through the resin layer. The seal of the present invention comprises a sealed portion containing a first oxygen absorber that reacts with oxygen flowing into the inside, and a central portion containing a second oxygen absorber that reacts with residual oxygen in the package. A striking feature.

In addition, the second feature is that the central portion has a larger oxygen absorption than the oxygen absorption of the sealed portion as compared with the unit weight of the oxygen-absorbing agent-containing resin composition. It is.

That is, in the present invention, the central portion contains a second oxygen scavenger having a relatively large oxygen absorption. This central part is in sufficient contact with the oxygen in the headspace present inside the container, and the oxygen scavenger is activated by moisture and heat during heat sterilization such as retort sterilization, which quickly reduces the oxygen present in the container. Absorb.

By the way, during heat sterilization such as retort sterilization, the resin layer in the container lid has a relatively large value of gas permeability due to heating, and also absorbs oxygen at the central portion.
Oxygen permeation through the resin layer occurs in a non-negligible order because the oxygen partial pressure may be low in the container.

In the present invention, by including an oxygen scavenger in the resin of the sealed portion, the oxygen scavenger reacts with oxygen flowing into the package from outside the package during heat sterilization such as retort sterilization, thereby reducing the oxygen content. Can be prevented. The oxygen absorption of the sealed part can be made smaller than the oxygen absorption of the central part because the oxygen permeation of the sealed part occurs through a relatively small cross-sectional area.
The central part containing the oxygen absorber also contributes.

In the present invention, the oxygen absorption amount of the sealed portion is
Being smaller than the oxygen absorption amount in the central portion provides many advantages not only in quickly absorbing the oxygen present in the container, but also in that the sealing performance is not impaired. That is, even when the first and second oxygen absorbers are common, the oxygen absorber can be contained at a higher concentration in the central portion not directly related to sealing than in the sealed portion, Thereby, oxygen existing in the container can be rapidly absorbed.
On the other hand, the content of the oxygen scavenger in the sealing portion directly related to the sealing performance can be reduced to reduce the influence on the sealing performance.

According to the present invention, the above-mentioned actions are combined to prevent the contents from being altered by oxygen during heat sterilization and oxygen permeating into the container through a liner or packing due to long-term storage. Browning is prevented and excellent long-term storage of the contents is obtained.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

[Container Lid] In FIG. 1 showing the entire structure of several examples of the container lid of the present invention, A shows an example of a crown, and B shows an example of a cap. These container lid shells 1 are formed by press-forming or drawing of a painted metal plate, and include a top surface 2 and a skirt portion 3 hanging from the periphery of the top surface 2. On the inner surface side of the top surface 2, a sealing resin layer (liner or packing) 4 made of polyethylene, soft vinyl chloride resin or other elastomer or rubber is provided, and these are the tips of the container neck (not shown). Sealing is performed in close contact with the part. In the crown shown in A, the skirt 3 is provided with a pleat 5 for fastening by tapping, while in the cap shown in B, the skirt 3 is provided with a screw 6 for fastening to the container. .

In FIG. 2 showing the cross-sectional structure of the coated metal plate of the container lid of the present invention, this coated metal plate 10 is made up of a metal plate 11 and an adhesive paint applied to a surface serving as an inner surface of the lid of the metal plate. An inner protective coating 12 is formed on the outer surface of the metal plate, and an outer protective coating 13 is formed on the outer surface of the lid of the metal plate. The liner 4 and the like 4 are integrated with the shell 1 via the inner coating film 12 on the top surface 2. The liner 4 comprises a central portion 14 in contact with the contents of the container and a sealing portion 15 on the outer peripheral side thereof. In the present invention, the sealing portion 15 contains a first oxygen absorber 16 that reacts with oxygen flowing into the package from outside the package through the resin layer 4, while the central portion 14 contains the remaining oxygen in the package and It contains a second oxygen scavenger 17 that reacts.

The container lid of the present invention is particularly useful as a lid for containers where the exposed area of the liner or packing to the headspace in the container is relatively small. That is, in a container such as a bottle, the container opening is narrowed to a small diameter, and the container lid is also reduced in diameter accordingly.Thus, the exposed area of the liner or the packing to the head space is small, but the central part is By having a large oxygen absorption amount, oxygen in the headspace can be well absorbed even if the exposed area of the liner or packing is small.

[0018] The container lid shell should have such a rigidity that the sealing by the liner or the packing is maintained irrespective of the pressure difference between the inside and outside of the container, and is made of various metals, plastics or composites thereof. Is good. As the metal, a light metal plate such as aluminum or an aluminum alloy, or a surface-treated steel plate such as tinplate or tin-free steel is used. Examples of the plastic include high-density polyethylene, polypropylene, thermoplastic polyester, polyamide, and styrene resin. The shape of the shell may be a crown, a screw cap, a pill fur proof cap, a lug cap, a white cap, a tab tear open cap, or the like.

[Liner or Packing] In the present invention, the liner is applied to the lid and shell of the container and formed into a shape required for sealing in place. On the other hand, the packing is formed into a predetermined shape outside the container. And then applied to the container. With these liners or packing,
A resin or rubber, or a laminate of these with paper, metal foil, or the like can be used as long as the condition that the above-described concentric multilayer oxygen-containing resin layer is provided is satisfied. The liner or the packing may be formed of the oxygen-containing agent-containing resin alone, or may be a composite of the oxygen-containing agent-containing resin and another liner or packing material.

The oxygen-absorbing resin layer is made of a resin containing a deoxidizer, but may be a composition in which a resin for oxygen oxidation is added to the resin to oxidize the resin itself. Generally, the former is preferred. The oxygen scavenger includes an inorganic or organic scavenger. Further, together with the oxygen scavenger, an accelerator for accelerating the oxygen scavenging action may be added. The accelerator may be one that directly contributes to deoxygenation or one that has a function of improving the oxygen permeability coefficient and the amount of adsorbed moisture. Oxygen-absorbing resin composition, the oxygen permeability coefficient at 20 ° C. and 0% RH 10 ^- moisture adsorption amount at large and 20 ° C. pure water than ^{1 2 cc · cm / cm 2} · sec · cmHg 1 % Of the resin is preferably a composition obtained by blending an oxygen scavenger with the resin. Examples of the oxygen scavenger are as follows.

(A) Inorganic oxygen scavenger Specific examples of the inorganic oxygen scavenger include iron group metals such as iron powder or iron powder coated with a metal halide, iron carbide, silicon iron, and other iron group. Metal alloy; ferrous sulfate, ferrous chloride
Examples thereof include compounds of a divalent iron group metal such as iron and ferrous oxide. These compounds are desirably used together with an accelerator described later. The oxygen scavenger may be water-soluble or insoluble, but it is desirable to use a water-insoluble oxygen scavenger in order not to impair the flavor retention of the contents. It is also possible to knead a granular material as a deoxidizer in a resin so as not to elute.

(B) Organic oxygen scavenger Specific examples of the organic oxygen scavenger include polyhydric phenols such as catechol and pyrogallol, or phenolic resins, ascorbic acid, erythorbic acid or tocopherol, glucose, fructose, galactose, and the like. Sugars such as maltose and cellobiose and their enzymatic agents, hydroquinone, gallic acid and the like can be used. The organic oxygen scavenger is preferably a phenolic resin that is insoluble in water and has a large molecular weight from the viewpoint of retaining the flavor (flavor) of the content and preventing migration and elution into the content.

As the phenolic resin, a hydroquinone aldehyde resin is preferred. This oxygen scavenger comprises a resin having a group having an oxygen absorbing property on a molecular chain, particularly a hydroquinone aldehyde resin having a plurality of phenolic hydroxyl groups per ring in a phenol skeleton.

The oxygen scavenger is generally a resin 100
0.1 to 100 parts by weight, especially 5 to 50 parts by weight
Formulated in parts by weight. That is, when the amount of the oxygen scavenger is smaller than the above range, the effect of absorbing the residual oxygen is unsatisfactory. On the other hand, when the amount is larger than the above range, the cushioning property, elasticity, sealing function, etc. inherent to the sealant are impaired. become.

In the present invention, the central portion has a larger oxygen absorption amount than the oxygen absorption amount of the sealed portion, but the central portion has an oxygen absorption amount (Vc ) Is 1 to 10 of the oxygen absorption amount (Vo) of the sealed portion.
It is preferably 0 times, especially about 5 to 50 times. When the first oxygen absorber contained in the sealed portion and the second oxygen absorber contained in the central portion are common, the central portion contains a higher concentration of the oxygen absorber than the sealed portion. The concentration of the oxygen scavenger (Cc) in the central portion is preferably about 1 to 100 times, particularly about 5 to 50 times the concentration (Co) of the oxygen scavenger in the sealed portion.

In the present invention, an accelerator can be added together with the oxygen scavenger. As the accelerator, an electron-donating substance that directly acts on the oxygen absorber and a hydrophilic substance that makes the oxygen absorber contain moisture can be used. Such accelerators, in addition to the liner shapes described above, also achieve rapid removal of oxygen.

The amount of the electron donating substance is preferably 1 to 1000 parts by weight, more preferably 10 to 200 parts by weight, per 100 parts by weight of the oxygen scavenger. As electron donating substances, sodium chloride, potassium chloride, calcium chloride,
General materials such as sodium sulfate and sodium nitrate can be used. Organic or inorganic oxygen scavengers are usually significantly promoted on the alkaline side, and it is particularly desirable to use a solid base as an accelerator. As the solid base, water-insoluble ones are desirable in view of the flavor retention and sanitary properties of the contents, such as zinc oxide,
Examples include magnesium carbonate, silicate, anion exchange resin, zeolite, melamine resin, urea resin, and ammonia resol resin.

The hydrophilic substance can be provided as a dispersed phase in the resin to promote the oxygen absorbing reaction of the oxygen scavenger. Specific examples of the hydrophilic substance include the following, which are at 20 ° C. based on the JIS standard test method.
It is preferable that the rate of weight increase when immersed in pure water for 24 hours is 1% or more, and particularly 2.0% or more in practice.

The hydrophilic substance is preferably a polymer in order to suppress dissolution. For the purpose of accelerating the oxygen absorption reaction, polyvinyl alcohol, methylcellulose, ethylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, etc. Cellulose derivative, partially saponified polyvinyl acetate, polyvinyl methyl ether, polyacrylic acid, polymethacrylic acid, vinyl methyl ether / maleic anhydride copolymer, polyvinylpyrrolidone, acrylamide / acrylate copolymer, acrylamide / methylenebis Partially saponified acrylamide copolymer, saponified vinyl acetate / methyl acrylate copolymer, polyoxyethylene compound, polystyrene sulfonic acid, poly-2-
Acrylamide-2-methylpropanesulfonic acid and hydrophilic high molecular compounds such as gelatin, denatured casein, denatured starch, sodium alginate, and tracant gum are preferred. These polymers have a total content of 1% by weight or more, especially 1% by weight.
It is desirable to add 0% by weight or more.

The resin containing the oxygen scavenger or the accelerator may be any resin, but is preferably a resin commonly used for forming a liner or a packing. Examples of such a resin include resins or rubbers known per se having appropriate elasticity and cushioning properties, particularly soft vinyl chloride resins, low-density polyethylene, ethylene-vinyl acetate copolymer, and low-density polyethylene / ethylene-vinyl. Alcohol copolymer blend, ethylene-propylene copolymer, thermoplastic styrene-butadiene-styrene block copolymer, thermoplastic styrene-isoprene-styrene copolymer, ethylene-propylene rubber,
Ethylene-propylene-non-conjugated diene rubber, styrene-butadiene rubber, nitrile-butadiene rubber, butyl rubber, natural rubber, polybutadiene, chloroprene
Examples include rubber, polyurethane, acrylic rubber, silicone rubber, and the like. Of these, low-density polyethylene, ethylene / propylene copolymer rubber, plastisol of vinyl chloride resin, styrene-butadiene rubber (SBR), especially solvent type SBR, etc. are suitable for container liners because of their excellent sealing properties and processability. I have. These can be used alone or, if necessary, in combination of two or more kinds. In these resins or elastomers, a resin compounding agent known per se, for example, a plasticizer,
Fillers, colorants, heat stabilizers, foaming agents, cross-linking agents, and the like can be blended according to a formulation known per se.

The liner or packing provided with the oxygen-absorbing resin layer can be formed by any means so as to form the above-described concentric multilayered oxygen-absorbing agent-containing resin layer. For example, in the case of applying a resin melt or plastisol in a container lid body and embossing it to form a liner, that is, in the case of an in-shell mold, first, a deoxidizer-containing resin composition having a high oxygen absorption rate first May be embossed to form a central portion, and then a deoxidizer-containing resin composition having a low oxygen absorption rate may be embossed to form a sealed portion. Alternatively, as a core, a deoxidizer-containing resin composition having a high oxygen absorption rate is used as a core, and as a shell, a deoxygenator-containing resin composition having a low oxygen absorption rate is used as a shell. To form a concentric liner or packing.

In the present invention, the oxygen-absorbing resin layer in the liner or in the packing may be exposed on the inner surface of the container. However, if the oxygen-absorbing agent before or after the reaction with oxygen may be eluted, Preferably, a thin coat layer for preventing elution is provided on the oxygen-absorbing resin layer. Of course, this coat layer is permeable to oxygen or water vapor, but not permeable to water as a liquid. Suitable coating layer, the oxygen permeability coefficient of ^{10 × 10 - 1 2 cc ·} cm / cm
² · sec · cmHg or more, particularly ^{50 × 10 - 1 2 cc ·} cm / cm 2 · s
A resin of ec · cmHg or more is desirable. The water absorption is 2
The pure water at 0 ° C. is desirably at least 1%, particularly preferably at least 2%. For example, polyethylene, soft vinyl chloride resin, various synthetic rubbers, porous polyolefin, silicone resin, etc., which are 1 to 50 μm, particularly 2 to 20 μm
It is good to provide with the thickness of. The coating film can be provided on the liner exposed surface in the form of a coating solution, a film, or the like.

[0033]

The effects of the present invention will be described with reference to the following examples. Example 1 Epoxyphenol-based paint as a primer and vinylphenol-based resin as a paint for bonding to a liner agent were applied to an aluminum plate having a thickness of 0.2 mm at 160 to 220 ° C, respectively.
Baking and drying sequentially for about 10 minutes in each temperature range, so that the surface coated with the paint becomes the inner surface of the cap,
A cap having a diameter of 60 mm was punched out to form a shell of a rimple cap.

100 parts by weight of a vinyl chloride resin as a PVC plastisol, 90 parts by weight of an acetylated glycerin fatty acid ester as a plasticizer, and azo as a foaming agent for a liner material of a sealing portion of a cap and an inner center portion of a sealing portion of a cap. 0.4 parts by weight of dicarbonamide,
After weighing 5 parts by weight of titanium oxide and 3.5 parts by weight of a stabilizer as a coloring agent, a small amount of a metal halide was added thereto, and further, as shown in Table 1, the composition of the present invention and the same as shown in Examples. It was prepared by adding the amount of reduced iron.

About 1 g of these plastisols are applied in a ring shape as a cap sealing liner, and about 1 g of the plastisol is applied evenly and in a disc shape evenly so as not to contact the ring-shaped liner material. Immediately, baking and drying was performed at 220 ° C. for 1 minute in a gas oven.
Test cap samples were prepared with the cap configurations shown in Table 1, and the following performance tests were performed.

1. Juice filling 200ml glass bottle with sugared orange juice 100
g, and further warmed to 90 ° C., and 70 g of syrup was added. Then, each of the caps shown in Table 1 was stoppered.
Heat treated at 40 ° C. for 40 minutes. After cooling, all the samples were inverted and left at room temperature for one to three months to perform the following tests.

2. Measurement of Dissolved Oxygen (DO) Concentration of Syrup The cap of the orange juice that had been left at room temperature for one month was opened, and the dissolved oxygen concentration of the syrup was measured with a dissolved oxygen concentration meter.

3. Changes in browning of orange juice The progress of browning of orange juice that had been left at room temperature for 3 months was visually observed. The progress was classified as follows. (1) Good progress with little progress observed ◎ (2) Slight progress, but almost good ○ (3) Progress progress × (4) Clear progress, poor XX

4. Evaluation results The test results are as shown in Table 1.
The present inventions 1, 2, and 3 in which plastisol is added to the liner material of the cap sealing portion by adding 1% to 20% to the liner material of the cap sealing portion, the dissolved oxygen concentration is the smallest, and the juice is not browned. there were. This is because the reduced iron in the plastisol applied to the center of the cap quickly reacted with the dissolved oxygen dissolved in the juice since the bottle was left standing upside down. Oxygen in the air permeates through the liner portion of the cap and moves into the bottle, but reacts with reduced iron added to the cap liner material to prevent permeation into the juice in the bottle.

In the comparative example, even if a plastisol containing a large amount of reduced iron was applied to the cap sealing portion to form a liner material, the dissolved oxygen concentration and the progress of browning were all inferior to those of the present invention. This is because, when a large amount of reduced iron is added to the liner material of the sealing part, the hardness of the liner material increases,
In addition, the shape of the foam cell became uneven, the original sealing function was reduced, oxygen in the air was easily transferred to the inside of the bottle, the dissolved oxygen concentration was increased, and the browning of oranges was greatly affected. . Further, when reduced iron was not added to the liner material, oxygen outside the bottle permeated through the liner material, and the results were also poor. Even if the same amount was added to the sealing part and the central part, the result was still inferior. Both the sealed portion and the central portion, to which no reduced iron was added, were the poorest. From these results, the present invention, in which a small amount of reduced iron was added to the liner material serving as the sealing portion of the cap, and a large amount of reduced iron was added to the inner surface of the cap in contact with the inner solution in the bottle, the The dissolved oxygen concentration was maintained at a low value for a long time, and the progress of browning was hardly promoted.

[0041]

[Table 1]

Example 2 The same test as in Example 1 was carried out, except that 30% of reduced iron was added as an additive to the plastisol in the center of the cap as in Example 1. As shown in Table 2, the results of the present inventions 1 to 3 were the most excellent, and all others were inferior. This was the same tendency as in Example 1.

[0043]

[Table 2]

Example 3 In the same manner as in Example 1, ascorbic acid sodium salt was added to plastisol instead of reduced iron as an additive.
A sample cap was prepared with the following cap configuration, and the same test as in Example 1 was performed. The results are shown in Table 3. As shown in Table 3, addition of an appropriate amount of sodium ascorbate to the plastisol in the center portion of the cap and addition of an appropriate amount to the plastisol in the liner material portion of the cap were also performed. 3 gave the best results.

[0045]

[Table 3]

[0046]

According to the present invention, in a container lid comprising a container lid shell and a deoxidizer-containing resin layer provided on the inner surface side of the shell top plate, the resin layer is packaged through the resin layer. A sealed portion containing a first oxygen absorber that reacts with oxygen flowing into the package from outside and a central portion containing a second oxygen absorber that reacts with residual oxygen in the package; Compared on a unit weight basis of the oxygen-containing resin composition, the central portion has an oxygen absorption amount larger than the oxygen absorption amount of the sealed portion, so that it is present in the container during heat sterilization such as retort sterilization. In addition to the rapid absorption of the oxygen produced, the oxygen permeating into the container through the liner or packing is captured, thereby improving the flavor retention of the contents of the sealed container such as a bottled product. . In addition, by providing the concentric multilayer oxygen-containing resin layer, it was possible to prevent the sealing performance of the liner or packing from being impaired.

[Brief description of the drawings]

FIG. 1 is a side view and a cross-sectional view showing the entire structure of several examples of a container lid of the present invention, wherein A shows an example of a crown, and B shows an example of a cap.

FIG. 2 is a cross-sectional view showing a cross-sectional structure of a coated metal plate and a resin layer containing a deoxidizer of a container lid of the present invention.

[Explanation of symbols]

1 is a container lid, 2 is a top surface, 3 is a skirt, 4 is a sealing resin layer (liner or packing), 5 is a fold, 6 is a screw, 10 is a painted metal plate, 11 is a metal plate, and 12 is inner surface protection. A coating film, 13 is an outer surface protection coating film, 14 is a central portion, 15 is a sealing portion, 16 is a first oxygen scavenger, and 17 is a second oxygen scavenger.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B65D 51/28 B65D 53/04

Claims (2)

(57) [Claims] 1. A container lid comprising a container lid shell and a deoxidizer-containing resin layer provided on the inner surface side of the shell top plate, wherein the resin layer flows into the package from outside the package through the resin layer. A sealed portion containing a first oxygen absorber that reacts with oxygen, and a central portion containing a second oxygen absorber that reacts with remaining oxygen in the package, and a resin composition containing an oxygen absorber. A container lid having excellent long-term storage, characterized in that the central portion has an oxygen absorption amount larger than the oxygen absorption amount of the sealed portion as compared with a unit weight basis. 2. The method according to claim 1, wherein the first and second oxygen absorbers are common, and the central portion contains the oxygen absorber at a higher concentration than the sealed portion. Container lid.