JPH02269667A - Container lid - Google Patents

Abstract

PURPOSE:To prevent the oxidative degradation of contents and the growth of microorganisms by impregnating oxygen absorbent in a gasket by a method wherein it is kneaded with resin component, dispersed in resin solution or molten resin or dispersed in the resin upon blending plasticizer therewith. CONSTITUTION:A sealing gasket is a plastisol composition consisting of vinyl chloride paste resin, plasticizer and oxygen absorbent. The oxygen absorbent is impregnated in the gasket by a method wherein it is kneaded with the resin component, dispersed in resin solution or molten resin or dispersed in the resin upon blending the plasticizer therewith. In doing so, the gasket resin can contain the above-mentioned components almost perfectly. Therefore, oxygen in the dead space of a container can be efficiently removed, without the function and workability of the gasket being lowered and the intrusion of oxygen from outside through the resin layer can be prevented.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a container lid with excellent preservability, and more specifically to a container lid that is used to remove residual oxygen in the head space of a package such as canned or bottled packaging, or the content of the container lid. The present invention relates to a container lid that absorbs dissolved oxygen and has the function of preventing oxidative deterioration of contents and growth of microorganisms.

(Problems to be solved by the prior art and the invention: a) Canning;
In the production of bottled products, there is always a space called a head space in the can body or the top of the bottle, and the oxygen remaining in this head space oxidizes and deteriorates the contents, and can also cause the growth of mold, yeast, bacteria, etc. The problem is that it causes

In order to remove oxygen from the headspace, water vapor or nitrogen gas is blown onto the can or bottle filled with the contents, replacing the air in the headspace with these gases, and then double-sealing the can or bottle with the contents. However, even with these methods, it is difficult to remove dissolved oxygen from the contents, and when canning or bottling fruits, fruit juices, vegetables, etc. It is known that oxygen causes deterioration of the contents.

The most commonly used method to prevent the effects of dissolved oxygen is to construct at least a portion of the container surface with metallic tin, and use the reducing action of the metallic tin layer to prevent the effects of residual oxygen. It is. However, if the container surface is made of tin, tin ions will inevitably elute into the contents.
From a sanitary standpoint, alternative methods and means are highly desirable.

Conventionally, it has the function of absorbing residual oxygen in the head space of packages such as canned and bottled products or dissolved oxygen in the contents to prevent oxidative deterioration of the contents and growth of microorganisms, etc. A lid is being considered.

Such a container lid is one in which an oxygen absorbent is embedded in a cork or foamed resin gasket, or the oxygen absorbent is covered with a porous film.

However, when an oxygen absorbent is embedded in cork or the like, it is not a continuous phase of cork or a dispersed phase kneaded into expanded polystyrene, but is merely retained and may be eluted into the contents of the container. Also, for those coated with a porous resin film, there is a problem in adjusting the diameter of the porous pores, and if they are too large! l. Problems such as elution of the oxygen absorbent or, conversely, permeation of the contents occur, and if the pore diameter is small, the action of the oxygen absorbent is inhibited.

The purpose of the present invention is to absorb residual oxygen in the head space or dissolved oxygen in the contents without leaching foreign substances into the contents or impairing the flavor of the contents, thereby reducing the oxidation of the contents. To provide a container lid that can prevent deterioration and growth of microorganisms.

Another object of the present invention is that under normal storage conditions it can be stored stably for a relatively long period of time without losing its oxygen absorbing properties;
On the other hand, it is an object of the present invention to provide a container lid that quickly exhibits oxygen absorption performance when attached to a container filled with contents.

(Means for Solving Problem 11) According to the present invention, in a container lid consisting of a container lid shell and a gasket provided in a sealing part of the shell, the sealing gasket is made of paste vinyl chloride resin, plastic A plastisol composition comprising a plasticizer and an oxygen absorber, wherein the oxygen absorber is kneaded into the resin component, dispersed in the resin solution or molten resin, or dispersed when blending the plasticizer with the resin. Provided is a container lid characterized in that it contains

(Function) The container lid according to the present invention is characterized in that it uses a vinyl chloride resin for paste and a plasticizer in the gasket resin, and that the oxygen absorber is almost completely retained in the resin by dispersing it by kneading or the like. This effectively removes oxygen from the dead space inside the container without compromising the function or processability of the gasket, and also prevents oxygen from entering from the outside through the resin layer. Under storage conditions, the oxygen absorbent does not substantially lose its oxygen absorbing ability over a relatively long period of one month or more, and the oxygen absorbent does not dissolve into the contents of the container.

The present invention uses a vinyl chloride resin for paste as a gasket. Vinyl chloride resin for paste is suitable for container gaskets because it has excellent sealing properties and processability, and especially in the form of plastisol, it can be poured into container lid shells and molded. However, such a resin is permeable to oxygen, and although there is no problem with sealing performance in preventing the entry of bacteria and the like, there is a risk that oxygen may enter the container through the resin layer. The present invention is based on such knowledge,
The present invention is designed to suitably arrange an oxygen absorbent in the dead space of a container, and the effects of the present invention will be described below.

When the oxygen absorbent is kneaded into the resin as in the present invention, it is different from when the oxygen absorbent is simply attached to the gasket. First, there is a concern that the addition of an oxygen absorbent will reduce the functionality of the gasket resin. However, due to the addition of plasticizer to PVC resin for paste,
There are almost no problems with sealing performance. In addition, since it is in the form of plastisol, there are no problems with processability. In particular, when a solid oxygen absorber is used, it is extremely suitable for handling.

Next, the oxygen absorbent does not elute and does not impair the flavor etc. of the contents of the container. Since the oxygen absorbent is completely retained in the resin, almost no separation is observed. Additionally, an oxygen absorber is present in the resin to sufficiently absorb oxygen entering the resin layer. It not only efficiently absorbs oxygen in the dead space of the container, but also captures oxygen that attempts to enter from the outside through the resin layer. This improves long-term storage stability.

That is, in the early stages of sealing, the oxygen absorbent works well within the container, so no problem occurs even if oxygen enters from the outside through the resin. However, over a long period of time, when the function of the oxygen absorber was almost lost, the inside was almost completely depleted of oxygen due to the action of the initial oxygen absorber. After that, oxygen enters from the outside through the resin layer and cannot be prevented.6 In the present invention, if an oxygen absorbent is kneaded into the resin and is present in a small amount, it will prevent oxygen from entering from the outside for a long time. period can be prevented.

Furthermore, if the oxygen absorbent described above is completely dispersed and mixed into the plastisol, its ability will be halved and it will no longer be able to quickly capture oxygen. Therefore, it is desired to increase the oxygen scavenging ability. In the container 1 of the present invention, when the electron donating substance or the hydrophilic polymer compound is made to coexist with the oxygen absorbent, the oxygen scavenging ability is sufficiently exhibited as seen in Example 2 described below. Moreover, as seen in Example 1, the oxygen in the head space of the container after one week was one-tenth of the initial amount.
decreases to

It is thought that when the above polymer compound is added and kneaded, plastisol has increased water vapor permeability and water retention. In the present invention, the reaction or oxygen scavenging ability of the oxygen absorbent increases unexpectedly when there is water or humidity, and the gasket resin is placed in a hot atmosphere inside the container, so that the gasket resin is If there is water vapor in the inner head space, it permeates the water vapor and retains the water, and this water effectively increases the oxygen scavenging ability of the oxygen absorbent kneaded with the resin, and quickly captures oxygen in the dead space. be done. Further, in the present invention, an electron donating substance can be kneaded in order to enhance the oxygen scavenging ability of the oxygen absorbent in the plastisol. When such an electron-donating substance is present, the reaction of the oxygen absorbent is activated due to the electron-donating action, and oxygen in the container is quickly captured.

Furthermore, when combined with a hydrophilic polymer compound, the electron-donating substance has a markedly increased oxygen scavenging ability in the presence of water.
Gaskets provide excellent oxygen scavenging.

(Preferred Embodiment 1 of the Invention) The present invention will be described in detail below with reference to specific examples shown in the accompanying drawings.

In Fig. fi1 showing the cross-sectional structure of the container lid of the present invention, the container lid consists of a container lid shell 1 and a sealing gasket 2. This container lid shell 1 includes a top plate (center panel) 3 integrally formed of metal, plastic, etc.
and a skirt portion 4 around it. A sealing gasket 2 is provided on at least the portion of the inner surface of the container lid shell 1 that engages with the container mouth. In FIG. 2 showing an enlarged cross section of this sealing gasket 2,
This sealing gasket 2 consists of a continuous phase consisting of an elastomer polymer 5 and a dispersed phase consisting of a water-insoluble solid oxygen absorber 6.

An important feature of the present invention is that, as mentioned above, the inclusion of a solid oxygen absorbent in a sealing gasket made of an elastomeric polymer allows the gasket to maintain a relatively long life, such as one month or more, under normal storage conditions. It is stably maintained over a long period of time without substantially losing its oxygen absorption properties,
On the other hand, when the contents are packed in cans or bottles, this gasket is exposed to an extremely high humidity atmosphere, so within a very short period of time, such as within 4 days,
This is based on the knowledge that residual oxygen in the packaging container is almost completely absorbed.

According to the present invention, residual oxygen in the packaging container can be absorbed into the gasket within a relatively short period of time, thereby preventing oxidative deterioration of the contents and preventing the growth of mold, yeast, bacteria, etc. becomes. In addition, the oxygen absorbent in the gasket exhibits a higher oxygen absorption rate as the temperature increases, so when hot filling the contents, hot water sterilization, retort sterilization, etc., the oxygen absorbent remains extremely quickly. The advantage of being able to remove oxygen is also achieved.

Below, the original text will be explained in the following order: oxygen absorbent, plastisol used, electron donating substance, and hydrophilic polymer compound.

In the present invention, from the viewpoint of retaining the flavor of the contents and preventing migration and elution into the contents,
The oxygen absorbent is preferably insoluble in water and has a large molecular weight.

(a) Phenol aldehyde resin Preferably, the oxygen absorbent is a resin having an oxygen-absorbing group on its molecular chain, especially a resin having a plurality of phenolic hydroxyl groups per ring in the phenol skeleton. Consists of phenolic aldehyde resin.

The oxygen absorption effect of the phenol/aldehyde resin used in the present invention is expressed by the following chemical formula. Polyhydric phenols such as hydroquinone themselves have oxygen absorbing properties, but if such polyhydric phenols are used as they are, they may elute into the contents,
Migration becomes a problem. On the other hand, when this polyhydric phenol is incorporated into a phenol aldehyde resin as a phenol skeleton, its alkyl substitution effect significantly promotes oxygen absorption. Not only that, by polymerizing polyhydric phenol as a resin, its elution and migration into the contents is completely suppressed, and as is clear from the chemical formula (1) above, the absorbed oxygen is harmless in the form of water. It is something that can be converted into

The phenol skeleton that forms this phenol-aldehyde resin is derived from phenols containing polyhydric phenols represented by the following formula (wherein R represents a hydrogen atom, a hydroxyl group, an alkyl group, an amino group, or a halogen atom). be done. In the above general formula (2), it is particularly desirable that the two phenolic hydroxyl groups be in the para position for the production of phenol aldehyde resin. Suitable examples of the phenols of the above general formula (2) include hydroquinone, catechol, Examples include methylhydroquinone and pyrogallol, with hydroquinone being particularly preferred. The polyhydric phenol used is preferably bifunctional or more polyfunctional with respect to the aldehyde, but -functional phenols can also be incorporated into the phenol skeleton in the form of polymer chain terminals.

In the production of phenol/aldehyde resin, the polyhydric phenol of general formula (2) above can be used alone or in combination with other phenols. As a monocyclic-valent phenol and one ring per ring,
Examples include polynuclear phenols in which several phenolic hydroxyl groups are bonded. Monocyclic-valent phenols include trifunctional phenols, such as phenols represented by the formula (wherein R' is a hydrogen atom, a monovalent hydrocarbon group, or an alkoxy group);
In particular, carbonic acid 1m-cresol, m-ethylphenol, 3,5-xylenol, m-methoxyphenol, etc.; difunctional phenols, such as H. In the formula, R1 has the above-mentioned meaning, R2 is a hydrogen atom, 1
Difunctional phenols, especially difunctional phenols, which are valent hydrocarbon groups or alkoxy groups, in which 2 m of the three groups R2 are hydrogen atoms and one is a hydrocarbon or alkoxy group. -cresol, p-cresol, p-tert-butylphenol, p-ethylphenol, 2,3-xylenol, 2
．． -Functional phenols such as 5-xylenol, p-tert-alumylphenol, p-cyclohexylphenol, p-phenylphenol, etc., for example, in the general formula (4), one of the three groups R2 is a hydrogen atom and two of which are hydrocarbon groups or alkoxy, especially 2,4-xylenol, 2,6-
Examples include xylenol. On the other hand, the polycyclic phenol is a tetrafunctional phenol, for example, in the formula, R3 represents a direct bond or a divalent bridging group, particularly an alkylidene group having 10 or less carbon atoms, -o--s--5o- , especially 2,2-bis(4-hydroxyphenyl)propane [bisphenol A].

2.2-bis(4-hydroxyphenyl)butane [bisphenol B, 1.1-bis(4-hydroxyphenyl)ethane, bis(4-hydroxyphenyl)methane [bisphenol F]
], 4.4-dihydroxydiphenyl, and 4.4-dihydroxydiphenyl ether.

In the above-mentioned condensation reaction between phenols and aldehyde, it is important to ensure that the polyhydric phenol component of formula (2) is introduced into the phenol aldehyde resin without being oxidized. The oxidation reaction of polyhydric phenols is significantly accelerated on the alkaline side. From this point of view, in one embodiment, a phenol component and formaldehyde are condensed and polymerized in the presence of an acidic catalyst 1, such as oxalic acid, hydrochloric acid, phosphoric acid, etc., and used in the form of a novolac type phenol-aldehyde resin. When producing novolak-type phenol/aldehyde resin, the condensation reaction is carried out in a non-oxidizing atmosphere, such as a nitrogen stream or under vacuum, in order to prevent oxidation of the phenol component as much as possible. The degree of oxidation of is also influenced to some extent by the type of polyhydric phenol used. For example, hydroquinone is relatively stable to oxidation during clamping, while pyrogallol is relatively unstable to oxidation during clamping.

In the production of novolak resin, the formaldehyde component is preferably used in an amount of 0.7 to 3.0 mol per ring of the phenol component, and the molecular weight of the resin is within the same range as that of ordinary novolak resins, for example, 300 to 1,500. Can be in range.

In another embodiment of producing an oxygen absorbent, a resol type phenol aldehyde resin is produced by condensation polymerization of a phenol component and formaldehyde in the presence of an alkali catalyst such as ammonia, caustic soda, magnesium hydroxide, etc. A phenol aldehyde resin is reduced to obtain a reduced resol type phenol aldehyde resin containing a polyhydric phenol component in a non-oxidized state. Reduction of the resol resin can be easily carried out by a method known per se, for example, a hydrogenation method using a hydrogenation catalyst such as a palladium catalyst, or a method of bringing it into contact with a reducing agent such as hydrosulfide.

When producing a resol resin, the formaldehyde component is preferably used in an amount of 1.0 to 1.5 mole per ring of the phenol component, and the molecular weight of the resin is within the same range as that of a normal resol resin, for example, 300 to 700. Can be in range.

The polyhydric phenol-containing phenol aldehyde resin used in the present invention may be treated with known modifiers, such as fatty acids, polymerized fatty acids, resin acids (or rosins), drying oils, alkyd resins, etc., to the extent that its essence is not lost. After modification with one or more kinds, it can be combined with eboshiki resin, or both resins can be modified with vinyl acetal (butyral)! Of course, it is also possible to modify with a modifier such as N resin, amine resin, xylene resin, acrylic resin, silicone resin, wax, phosphoric acid, or amine. These modifiers are
0.01 to 5.0%, especially 0.01% to 5.0% based on the total amount of both resins.
．． It can be used in amounts of 1 to 2.0%.

These phenolaldehyde resins used in the present invention are used alone or in combination with other resins as oxygen absorbers. At this time, the resin solid content 10
It should be contained in an amount of 50 mmol or more, especially 100 mmol or more per 0 g. That is, if the content of the polyhydric phenol skeleton is less than the above range, sufficient oxygen absorption may not be obtained to effectively prevent oxidative deterioration of the food contents when used as an oxygen absorber. be. On the other hand, although there is no particular disadvantage in having a large amount of polyvalent phenol skeleton,
Since the zonation of the resin may decrease and the amount of soluble components may increase, the concentration of the polyhydric phenol skeleton should be 850 mmol/100 g or less, especially 800 mmol/100 g.
It is preferable that it is less than g.

(B) Inorganic Oxygen Absorber In the container lid according to the present invention, an inorganic oxygen absorber, especially a granular one, can be kneaded into the elastomer to prevent it from eluting.

Such oxygen absorbers may be water-soluble or insoluble, and specifically include iron powder, iron group metals such as iron powder coated with metal halides, iron carbide, silica iron, and others. Alloys of iron group metals; ferrous sulfate, chloride jl! 1
Examples include compounds of divalent iron group metals such as iron and ferrous oxide, and these are used together with the basic substances described below.

(c) Other organic oxygen absorbers In the present invention, organic oxygen absorbers can be used together with electron-donating substances. in particular.

Combinations of ascorbic acid, erythorbic acid, or tocopherol and electron-donating substances; Combinations of sugars such as glucose, fructose, galactose, maltose, and cellobiose with electron-donating substances, especially basic substances or sugar oxidases such as glucose oxidase : A combination of polyhydric phenol such as hydroquinone, gallic acid, catechol, pyrogallol, etc. and an electron-donating substance described below can be used.

Plastisol assembly The present invention uses a plastisol composition as a gasket. Gasket compositions usually include soft vinyl chloride resin, low density polyethylene, ethylene-vinyl acetate copolymer, low-density polyethylene/ethylene-vinyl alcohol copolymer, blend, ethylene-propylene copolymer, and thermoplastic. Styrene-butadiene-styrene block copolymer, thermoplastic styrene-isoprene-styrene copolymer, ethylene-propylene rubber, ethylene-propylene-nonconjugated diene rubber, styrene-butadiene rubber, nitrile-butadiene rubber, butyl rubber , natural rubber, polybutadiene, chloroprene rubber, polyurethane, acrylic rubber, silicone rubber, etc. However, plastisol compositions consisting of vinyl chloride resin for paste and plasticizer are suitable for container gaskets because their gaskets have excellent sealing properties and processability.In particular, vinyl chloride resins in plastisol form are difficult to handle and process. Excellent in sex. These compositions are thus applied to the lid in the form of a plastisol coating or in the form of a melt, so that the application to the lid is facilitated.

According to the present invention, the above-mentioned water-insoluble solid oxygen absorber is added in an amount of 0.1 to 50 parts by weight, particularly 5 to 40 parts by weight, per 100 parts by weight of the elastomeric polymer. Mix in amounts. That is, when the amount of oxygen absorbent is less than the above range, the residual oxygen absorption effect is unsatisfactory, while when it is more than the above range, the cushioning properties, elasticity, sealing action, etc. inherent to the sealant are impaired. become.

Various means can be employed to incorporate the oxygen absorber into the plastisol composition. For example, when blending the resin and plasticizer, the oxygen absorber may be incorporated in the form of a powder filler or in the form of a solution. In addition, when blending with the resin itself, powder of the WI elementary absorbent may be blended in the form of a tri-blend or during kneading.

When using vinyl chloride resin in the form of plastisol, the commonly used plasticizers include di-2-ethylhexyl phthalate, di-n-octyl phthalate, diisobutyl phthalate, diphenyl phthalate, diisodecyl phthalate, and butyl. Phthalic acid derivatives such as benzyl phthalate, ethyl phthalyl ethyl glycolate, butylphthalyl butyl glycolate, adipic acid such as di-2-ethylhexyl adipate, diisodecyl adipate, diisononyl adipate, di(butoxyethoxyethyl) adipate, etc. derivatives, azelaic acid derivatives such as di-2-ethylhexyl azelate, di-n-hexyl azelate, di-2-ethylhexyl sebacate, di-
Sebacic acid derivatives such as n-butyl sebacate, di-n-
Malenic acid derivatives such as butyl maleate, epoxidized soybean oil, epoxidized linseed oil, epoxidized butyl linseed oil fatty acid, epoxy derivatives such as epoxidized castor oil, chlorinated paraffins, glyceroyl triacetate, polyethylene glycol, and even 2-ethylhexyl. Phosphoric acid derivatives such as diphenyl phosphate and acetyl tri2
- Enoic acid derivatives such as ethylhexyl citrate, oleic acid derivatives such as butyl oleate, ricinol # derivatives such as butyl acetyl lysate, n
- Stearic acid derivatives such as butyl stearate, sulfonic acid derivatives, etc. can be used. The amount of plasticizer is appropriately contained depending on the softness of the plastisol of vinyl chloride resin.

In addition to the above-mentioned essential components, the sealant composition of the present invention can contain various components known per se. For example, calcium carbonate, silica, various clays, magnesium hydroxide, magnesium carbonate, aluminum silicate, magnesium silicate, sulfuric acid, etc. are used to increase the amount of the sealant, give it shape retention, and further adjust its physical properties. Fillers such as barium, diatomaceous earth, mica, and asbestos can be used, and in order to adjust the hue, white pigments such as titanium dioxide, carbon black, phthalocyanine blue, phthalocyanine green, Bengara, titanium yellow, etc. can be used. Raw materials can be mixed.

In addition, for the purpose of increasing the adhesion to the lids and bottle caps, a tackifying agent such as coumaron resin, petroleum resin, rosin, modified rosin, etc. can be added.

Furthermore, a stabilizer can be added when mixing an oxygen absorber into the composition or for the purpose of protecting the composition during embossing. In this case, commonly used plastisol water stabilizers can be used, but from a hygienic standpoint, stearic acid or lauric acid such as zinc, calcium, lithium, magnesium, aluminum, etc. are preferred.

In addition, when lowering the viscosity of plastisol for processing reasons, linear paraffin solvents such as diisobutyl ketone, methyl isobutyl ketone, butyl acetate, ethyl acetate, glycol ether, n-hexane, n-hebutane, Dilutes aromatic hydrocarbons such as benzene, toluene, and xylene, alcohols such as ethanol and methanol, naphthenic solvents such as cyclopentane, cyclohexane, and methylcyclohexane, and oils whose main components are terpene compounds such as myrcene and linalool. It can also be added as a solvent or dispersion solvent.

(Goto Soil 1, Part 1) In the present invention, the oxygen absorption reaction of (a) the phenol aldehyde resin with a polyhydric phenol skeleton, (b) the inorganic oxygen absorber, and (c) the mwi elemental absorbent described above is remarkable on the alkaline side. From this point of view, in the present invention, it is important to use in combination 1 to 1000 parts by weight, particularly 10 to 200 parts by weight, of an electron-donating solid base per 100 weight tS of the oxygen absorbent. Substances are those that can be involved in the exchange of electrons during the redox reaction of oxygen absorbers.For example, as electron-donating substances, water-insoluble substances are recommended in terms of flavor retention and hygienic properties of the contents. is desirable, and all electron-donating substances such as anion exchange resins, zinc oxide, magnesium carbonate, silicates, zeolites, melamine resins, deep core resins, and ammonia aresol resins can be used.

Further, as for the inorganic oxygen absorbent, it is preferable to use common ones such as sodium chloride, sodium sulfate, sodium nitrate, potassium chloride, and calcium chloride.

H4 In the present invention, it is important to provide a hydrophilic polymer compound as a dispersed phase in the plastisol in order to promote the oxygen absorption reaction of the oxygen absorbent. What is hydrophilicity?
Specifically, the following may be mentioned, but these are JI
Based on the S standard test method, the weight increase rate when immersed in distilled water at 23°C for 24 hours is 0. 1% or more, especially in implementation.

It is preferably 1% or more.

Such wood-philic polymer compounds satisfy the purpose of promoting oxygen absorption reactions, and specifically include gelatin, modified casein, modified starch, sodium alginate, tracanth gum, polyvinyl alcohol,
Methylcellulose, ethylcellulose, hydroxypropyl methylcellulose, and droxyethylcellulose,
Cellulose derivatives such as carboxymethyl cellulose, partially saponified polyvinyl acetate, polyvinyl methyl ether, polyacrylic acid, polymethacrylic acid, vinyl methyl ether/maleic anhydride copolymer, acrylate polymer, acrylic acid/vinyl alcohol copolymer Polymer, polyvinylpyrrolidone, acrylamide/acrylic 11! Salt copolymer, partially saponified acrylamide/methylcinbisacrylamide copolymer, saponified vinyl acid/methyl allylate copolymer, polyoxyethylene compound, polystyrene sulfonic acid, poly-2-acrylamide-2-methylpropane Wood-loving compounds such as sulfonic acid can also be blended. In addition, these hydrophilic polymer compounds have 1
% or more, especially 10% or more is desirable.

L Dish 1 In the present invention, the gasket can be formed only with a composition in which a solid oxygen absorber is dispersed and blended with a solid basic substance or a polymer compound in a plastisol polymer. Only the solid oxygen absorber compound composition can be formed.

For example, as shown in the back view of FIG. 3, the peripheral portion 7 of the sealing gasket is formed from plastisol or a composition containing no solid oxygen absorber, and the central portion 8 of the gasket is formed from plastisol or a composition containing a solid oxygen absorber. It can be formed from a composition.

In the gasket with the dispersed form shown in Figure 2, there is a risk that some of the solid oxygen absorbent particles may be exposed to the atmosphere inside the bottle, but this oxygen absorbent is water-insoluble and is not sufficiently incorporated into the dispersed phase. This avoids any negative impact on the contents.

Of course, in the present invention, even if the oxygen absorbent is water-soluble or water-soluble, it can be used for the above purpose by being contained in Gaskent in a form that does not dissolve into the contents.

In the enlarged sectional view of FIG. 4 showing another type B of the present invention,
This gasket 2 consists of a gasket body 2a made of water-soluble or water-soluble solid oxygen absorbent particles 6a dispersed in a continuous phase of plastisol 5, and a polymer coating 9 covering the surface of the gasket body 2a. ing. This polymeric coating 9 is chosen to be permeable to oxygen and water vapor, but not to liquid water.

In addition, as shown in Figure 5, in order to further improve the adhesion with the container lid or the protection of the metal lid, if the container lid body is permeable to oxygen, the center panel part is added to increase the oxygen gas barrier property. A polymer coating 9a can also be provided between the gasket 3 and the gasket body 2a.

Generally, it is desirable that the polymer coating 9.9a consist of an elastomeric polymer that does not contain solid oxygen absorbers.

A preferred polymeric coating 9 has an oxygen permeability coefficient of 10XI Q-
12cc-cm/cm2・sec-cmH1 or more, especially 50X10-12cc-cra/cta"5ec-cr
Polymers with sH1 or higher, such as polyethylene, soft vinyl chloride resin, various synthetic rubbers, etc.
It is preferable to provide the layer with a thickness of μ, particularly 2 to 20 μ. Of course, the same polymer coating 9a as the polymer coating 9 can be used, but if the purpose is to increase the oxygen gas barrier property, the oxygen permeability coefficient is 10 x 10''cc-cm/cm2.
・Sec-cmHg or less, especially 5 X 10-0-12
cc1/cm2°5ec0c+++H (the following polymers,
For example, hard vinyl chloride resins and polyamide resins are preferred.

In the present invention, the gasket can be applied to the container lid by means known per se. For example, in the case of a gasket having the shape shown in FIGS. 1 to 3 and 4, the lid is rotated on a rotating chuck. A sealant composition in the form of a coating liquid is injected into the gasket from a nozzle, and is dried or gelled to form a sealing gasket. Alternatively, the blended composition is melt-extruded onto the lid and embossed while cooling to form a backing in a predetermined shape. Of course, it is also possible to form a backing into a predetermined shape by applying a powder or preform of the blended composition onto the lid, pressing the powder under heat, and then cooling. Furthermore, the water-impermeable polymer coating may be produced in the form of a coating solution, film, etc. by manufacturing a gasket of the compounded composition outside the lid and attaching or fitting it inside the lid. It may be provided on top of the oxygen absorbent-containing gasket.

The invention is illustrated by the following example.

Example 1 A resin powder obtained by addition condensation of hydroquinone and formaldehyde was mixed with a vinyl chloride resin for paste, a plasticizer, a stabilizer,
A plastisol of the following composition is made of a coloring agent.

Table 1 Formulation This plastisol was applied to the inner surface of a screw cap for a glass bottle and heated to gel to form a container lid. Bottle capacity 2
The bottle was filled with air-saturated distilled water so that 5% head space remained, and the bottle was sealed by tightening the cap. The amount of oxygen in the headspace was measured over time using gas chromatography. After 3 days, 30% of the oxygen had been consumed.

The control product showed only a 4.5% decrease in oxygen.

Example 2 A plastisol containing the hydroquinone/formaldehyde resin of Example 1 and 2% sodium bicarbonate based on the sol composition was similarly applied to the inside of the screw cap and heated to gel to form a gasket. The bottle was filled with air-saturated distilled water so that 172 mm of the bottle capacity remained as a head space, and the bottle was sealed with a screw cap having a gasket. Table 2 shows the amount of oxygen consumed by using this cap.

The bottle capacity is 150cc. The head space was filled with air-saturated distilled water to prevent leakage, and the amount of dissolved oxygen was determined using a dissolved oxygen meter. As shown in Table 2, the initial dissolved oxygen ff was 18.39 PPM, but after 3 days it was 0.
It became 7 PPM.

Table 2? 1! I Determination Results Example 3゜Vinyl chloride resin for paste, plasticizer, stabilizer, one color agent,
Reduced iron and metal halide are mixed into plastisol made of a blowing agent.

This plastisol is applied to the inner surface of a screw cap for a glass bottle and heated to gel to form a gasket. PVC/! on this gasket! Overcoat with I'll vinyl resin solution. The bottle was filled with air-saturated distilled water so that the volume of the bottle remained as a head space, and the bottle was sealed with a cap.

The oxygen concentration in the headspace and the amount of iron eluted were measured using an atomic absorption spectrophotometer. After 7 days at 50'C after sealing, the oxygen concentration in the headspace had reached the initial concentration of 172. No iron elution was observed. (0,05
(PPM or less) Iron elution of 0.58 PPM was observed in the case without overcoating during the same period.

Example 4゜Vinyl chloride for paste *i, plasticizer, stabilizer, colorant,
Hydroquinone and anion exchange resin powder were mixed into plastisol made of a blowing agent.

This plastisol was applied onto the cap and heated to gel, and then overcoated with vinyl chloride/vinyl acid resin. The container was filled with air-saturated distilled water so that 1/3 of the container capacity remained as a head space, and the container was sealed using this cap. The amount of 02 in the headspace and the elution amount were measured.

After one week at 50°C, the oxygen concentration in the headspace was 20% of the initial concentration. No elution was observed.

Example 5 Vinyl chloride resin for paste, plasticizer, stabilizer, colorant,
Reduced iron and metal halide are mixed into plastisol made of a blowing agent.

This plastisol is applied in a doughnut-shape to the inner surface of a screw cap for a glass bottle at the part that contacts the bottle mouth, and is heated to gel to form a gasket. The inside of the container was purged with nitrogen and the cap was tightened to seal it. When we measured the amount of oxygen that permeated through the gasket through the space between the cap skirt and the bottle mouth, it was 10-2cc/cap per day for the gasket that did not contain an oxygen absorber. The amount used was less than 5 x 10-3 cc/cap, and a clear effect was obtained.

Example 6゜Polypropylene/ethylene vinyl alcohol copolymer/
As a gasket for a multiple screw cap made of polypropylene, plastisol made of polyvinyl chloride for the base, a plasticizer, a stabilizer, a coloring agent, reduced iron, and a metal halide is applied in a donut shape to the inner surface of the camp in contact with the bottle mouth. , a gelatinized product was produced by heating. The inside of the container was purged with nitrogen and the cap was tightened to seal it. The amount of oxygen permeating through the gasket through the space between the cap, cap skirt, and bottle mouth was measured. The amount of permeation was 10-2 cc per day for 7 days in the case where no oxygen absorber was blended, but the amount permeated was about 1/3 in the case using this example, and a clear effect was obtained.

Example 7 A 10% glycine-10% xylose solution was packed into bottles so that 10 cc of head space remained, and a regular cap and the cap of Example 2 were attached, and changes in the degree of coloration were measured. After 30 days at 37°C, the degree of coloration of the conventional product was 1.6, whereas the product of the present invention was effective at 0.9.

Example 8 Entresses were stored in bottle containers with caps as in Example 2. Bottle capacity is 150 CCs Initial acid value 8.52
After a week, the value was 12.5, whereas the value was 28.1 with a normal cap that did not use the product of the present invention.

[Brief explanation of drawings]

Figures 1.4.5 represent the concept of the container lid of the present invention. FIG. 2 is an enlarged view of the gasket. FIG. 3 shows another embodiment of the container lid from the back. DESCRIPTION OF SYMBOLS 1... Container lid, 2... Gasket, 2a... Gasket, 3... Center panel part, 4... Skirt part, 5... Elastomer polymer, 6... Solid oxygen absorber (water-insoluble), 6a... solid oxygen absorber (water-soluble or water-soluble), 7... elastomer polymer,
8... Central part of galkerato, 9... Polymer coating, 9a
...Polymer coating, 10...Space. Applicant Toyo Seikan Co., Ltd.
Figure 2 Figure 3 Figure 4 Figure 5

Claims (15)

[Claims] (1) In a container lid consisting of a container lid shell and a gasket provided in the sealing part of the shell, the sealing gasket is a plastisol composition comprising a paste-grade vinyl chloride resin, a plasticizer, and an oxygen absorber; The container lid is characterized in that the oxygen absorber is kneaded into the resin component, dispersed in the resin solution or molten resin, or dispersed when blending a plasticizer with the resin. . (2) The container lid according to claim 1, wherein the oxygen absorbent is water-insoluble. (3) The resin contains an electron donating substance or a hydrophilic polymer compound.
Container lid as described in section. (4) The oxygen absorbent is a phenol compound having a plurality of phenolic hydroxyl groups per ring in the phenol skeleton.
The container lid according to claim 1, which is made of an aldehyde resin. (5) The phenol skeleton contains a polyhydric phenol represented by the following formula ▲ Numerical formula, chemical formula, table, etc. ▼ In the formula, R represents a hydrogen atom, a hydroxyl group, an alkyl group, an amino group, or a halogen atom. 5. The container lid according to claim 4, which is derived from phenols. (6) A patent claim in which the phenol/aldehyde resin is a novolac type phenol/aldehyde resin obtained by condensation polymerization of formaldehyde and a phenol component containing a phenol having a plurality of phenolic hydroxyl groups per ring. The container lid described in item 4. (7) The phenol/aldehyde resin is a resol type phenol/aldehyde obtained by polycondensation of a phenol component containing a phenol having multiple phenolic hydroxyl groups per ring with a formaldehyde component and subsequent reduction. The container lid according to claim 4, which is made of resin. (8) The phenol aldehyde resin contains a phenol skeleton having a plurality of phenolic hydroxyl groups per ring in an amount of 50 to 850 mmol per 100 grams of the resin solid content. Container lid as described in section. (9) The container lid according to claim 1, wherein the electron donating substance is an anion exchange resin, zinc oxide, magnesium oxide, calcium carbonate, zeolite, ammonia resol resin, melamine resin, or urea resin. (10) The oxygen absorber is a phenolaldehyde resin having a plurality of phenolic hydroxyl groups per ring in the phenol skeleton, and the phenolaldehyde resin 1
10. The container lid according to claim 9, wherein 1 to 1000 parts by weight of the electron-donating substance is present per 00 parts by weight. (11) The container lid according to claim 9, wherein the oxygen absorbent is a powder of an iron group metal or an alloy of iron group metals. (12) The container lid according to claim 11, wherein the oxygen absorbent comprises a compound of a divalent iron group metal. (13) The container lid according to claim 9, wherein the oxygen absorbent comprises a combination of ascorbic acid, erythorbic acid, or tocopherol and a basic substance. (14) The container lid according to claim 9, wherein the oxygen absorbent comprises a combination of saccharide and saccharide oxidase. (15) The container lid according to claim 8, wherein the oxygen absorbent comprises polyhydric phenol.