JPH0672459A - Manufacture of container lid with oxygen absorbing liner - Google Patents

Abstract

PURPOSE:To prevent degradation of content and reduction of flavor by a method wherein a specified flat small container is adhered to the inside of a container lid, so that remaining oxygen can be removed quickly. CONSTITUTION:A flat small container 7 comprises two sheets of oxygen permeable films 10 and deoxiding grains 11 charged between the two sheets of films 10 which are sealed on peripheral edge by heat sealing 10A after charging of the grains 11. In manufacturing a container lid, the flat small containert 7 is first prepared. In a container lid shell 1, melted thermo-plastic resin having cushion property and elasticity is supplied, pressed by a pressing die to mold a liner having a panel part 5 and a sealing part 6. Before temperaturer of a polymer in the panel part 5 comes down below the temperature at which the polymer begins to be viscous, the flat small container 7 is put on the panel part 5 and pressed against it. Otherwise, the panel part 5 to be formed is supplied with a slight amount of melted thermoplastic polymer, and then, the flat small container 7 is put on and pressed against it to adhere the container 7 to the panel part 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a container lid with a liner having a high oxygen absorption property, and more specifically, it has a combination of a sealing property and a high oxygen absorption property, and can be easily manufactured. And a method of manufacturing a container lid with a liner.

[0002]

2. Description of the Related Art In the production of hermetically sealed packages such as bottles, there is always a space called a head space above the bottle. Oxygen remains in the headspace after plugging, and oxygen causes oxidative deterioration of the contents, and further causes the growth of mold, yeast, bacteria and the like. In order to remove oxygen in the headspace, it is generally known that a bottle filled with contents is sprayed with water vapor or nitrogen gas to replace the air in the headspace with these gases, and then the lid is stoppered. ing. Gas replacement is excellent in that it removes oxygen in the headspace to some extent.

However, in order to carry out gas replacement, a large amount of cost is required for the gas cost and facilities. Further, even if the gas is replaced, it is difficult to completely remove oxygen in the head space, and much more difficult to remove even dissolved oxygen in the contents. In fact, it is known that canning and bottle filling of fruits, fruit juices, vegetables, etc. cause deterioration of the contents due to residual oxygen.

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

Japanese Patent Application No. 3-88 relating to the proposal by the present inventors
No. 592 is provided with a layer of an oxygen-absorbing resin composition in which a deoxidizer is mixed in a resin liner or packing, and the oxygen-absorbing resin composition layer is provided on the surface on the inner surface side of the container rather than the sealed portion. It has been proposed to improve the oxygen absorption rate by forming minute irregularities over almost the entire center side.

[0006]

The oxygen absorbent-containing liner found in the above proposal shows some improvement in the oxygen absorption rate, but the liner inside the container is closed immediately after stoppering and before sterilization or sterilization of the contents. The ability to remove the residual oxygen in the range to the extent that flavor and the like are not affected was not yet fully satisfactory. It is known that the flavor retention (flavor retention) of the contents has a close relationship with the residual oxygen concentration in the container, and is further damaged by heating during sterilization or sterilization. Therefore, an oxygen absorbent-containing liner that can remove residual oxygen in the container within a short time after plugging is desired.

The object of the present invention is to quickly remove the residual oxygen in the container, thereby preventing the deterioration of the contents and the deterioration of the flavor, and at the same time, reducing the flavor by providing an oxygen scavenger in the container lid. It is an object of the present invention to provide a method of manufacturing a container lid in which problems such as functional deterioration are solved. Another object of the present invention is that the structure is simple, the manufacturing is easy, and the initial absorption rate of residual oxygen in the container is excellent, and furthermore, the attachment of the oxygen scavenger to the container lid shell is reliable and easy. A method of manufacturing a container lid is provided.

Still another object of the present invention is to provide a method for producing a function-separated liner in which the oxygen absorbing function is highly exhibited without impairing the sealing performance.
Another object of the present invention is to provide a method capable of producing the container lid with a function-separated liner with excellent productivity and high quality.

[0009]

According to the present invention, a melt of a thermoplastic polymer having cushioning properties and elasticity is supplied into a container lid shell body, and the melt is pressed by a mold to form a central part. Is molded into a liner consisting of a panel part and a peripheral sealing part, and while the polymer of the panel part is at a temperature above the sticking start temperature, it is composed of an oxygen permeable film and has a granular or granular deoxidization inside. Oxygen absorption characterized by supplying a flat small container having a size filled with an agent and having a size to cover most of the central panel part to the panel part and pressing it to adhere to the central panel part on the entire back surface of the flat small container. A method of making a container lid with a flexible liner is provided.

According to the present invention, a melt of a thermoplastic polymer having cushioning properties and elasticity is supplied into the container lid shell body, and the melt is pressed by a mold so that the central panel portion and the peripheral Molded into a liner consisting of a sealing part, applying a small amount of the melt of the thermoplastic polymer to the formed panel part, consisting of an oxygen permeable film, filled with a granular oxygen scavenger and Oxygen characterized in that a flat small container having a size that covers most of the central panel portion is supplied to the panel portion and pressed, and the entire back surface of the flat small container is bonded to the central panel portion through the melt. A method of making a container lid with an absorbent liner is provided.

[0011]

In the present invention, the oxygen scavenger applied to the inside of the container lid shell is made of an oxygen permeable film, and is filled with a granular oxygen scavenger and has a size that covers most of the central panel portion. Select and use the flat small container type.

The reason why a liner using a layer in which an oxygen scavenger is dispersed in a resin is inferior in quick absorbability of oxygen is that the surface of the oxygen scavenger particles is covered with the resin and the oxygen It is considered that the absorption is affected by the diffusion rate of oxygen in the resin. That is, in the resin oxygen scavenger particle dispersion system, the diffusion rate of oxygen in the resin is the rate-determining step,
Therefore, the absorption rate of oxygen becomes slow.

When the oxygen absorber particles are used without being embedded in the resin, the effect of oxygen diffusion in the resin could be eliminated, but in this case, they must be handled in the form of powder. Therefore, there arises a problem that the oxygen absorber particles adhere to the member of the container lid or are mixed in the contents.

In the present invention, a flat small container made of an oxygen permeable film and filled with a powder-shaped oxygen absorber is used. In this flat small container, the oxygen scavengers exist as particles independent of each other and in a state where the specific surface area is extremely large. Oxygen scavenger particles are contained in a flat small container, but since the film forming this container is oxygen permeable, the oxygen outside the small container will be blocked by the difference in the oxygen partial pressure inside and outside the film. Oxygen permeates through the oxygen absorber and the permeated oxygen is immediately adsorbed by the oxygen absorber particles and removed by the reaction. Of course, in the case where the film is formed with gas-permeable micropores, oxygen more quickly flows into the inside of the small container through the micropores, and oxygen is absorbed more quickly.

Thus, according to the present invention, oxygen flows in through the oxygen permeable film and absorption of oxygen from the surface of the oxygen absorber particles occurs, so that in the resin found in the conventional oxygen absorber-containing liner. Oxygen remaining in the headspace or contents can be quickly absorbed and removed without being affected by the diffusion of oxygen.

Further, since the oxygen absorber particles are housed in the flat small container, not only is it easy to handle as a single component, but the oxygen absorber particles are released in the form of powder, and the container lid is closed. There is no problem that the material adheres to the member or is mixed in the contents.

In the present invention, a melt of a thermoplastic polymer having cushioning properties and elasticity is supplied into the container lid shell, and the melt is pressed by a mold to form a central panel portion and a peripheral sealing portion. A flat small container is supplied to the panel part to press it while the polymer of the panel part is at a temperature higher than the adhesion start temperature, or a thermoplastic polymer is applied to the formed panel part. A remarkable feature is that the flat small container is adhered to the central panel portion on the entire back surface of the flat small container by supplying and pressing the flat small container after applying a small amount of the melt. In the present specification, the sticking onset temperature of a polymer is defined as the rising temperature of an endothermic peak at the time of melting in the differential thermal analysis of this polymer.

According to the method of the present invention, the flat small container containing the oxygen scavenger particles is firmly and reliably heated to the central panel portion of the liner on the entire back surface thereof by utilizing the step of forming the container lid shell of the liner. Can be glued. That is, since the oxygen permeable film that composes the flat small container has a relatively small heat capacity, they are mutually welded by the heat of the central panel part in the middle of molding or the melt lumps of the polymer supplied separately. This thermal bonding can withstand the hot filling of the contents and the heat during the retort sterilization or the attack by the contents. Further, in the container lid according to the present invention, since the oxygen absorber particle-containing flat small container and the panel portion of the liner are in close contact with each other without a gap, during aseptic filling,
Even when the container lid is sterilized in advance, the sterilizing liquid does not remain in the gap between the oxygen absorber particle-containing small container and the panel portion of the liner, and there is an advantage that the flavor retention of the content is excellent. .

Further, according to the method of the present invention, the oxygen permeable film on the front side is melted because the small heat which the central panel part in the middle of molding or the melt lumps of the polymer supplied separately is used. Without being carried out, the oxygen absorber particles are maintained as they are, and the oxygen absorber particles are less likely to be implanted in the polymer, and the original excellent oxygen absorption performance is exhibited.

Further, the flat small container containing the oxygen scavenger is provided on the liner so as to cover most of the panel portion inside the sealed portion, so that the sealability of the liner is not affected. , A flat small container containing oxygen absorber particles,
It can be exposed in the maximum area in the sealed container, whereby the deoxidizing action can be sufficiently exerted. On the other hand, on the outer peripheral side of the panel portion, a thermoplastic polymer having cushioning properties and elasticity is present so as to project above the panel portion to form a sealing portion, so that excellent sealing performance is obtained. Not only is it obtained stably over time, but this cushioning thermoplastic resin also exists as a lower layer under the panel section, and since it has an integrated structure as a whole, in terms of strength, The liner has excellent adhesive structure. In the sealed storage state of the container, the oxygen permeation path from the outside of the container to the inside of the container through the sealing part and the panel part becomes a problem, but the container lid according to the present invention effectively captures such permeated oxygen. be able to.

Further, in the production of this liner, a melt of a thermoplastic polymer having cushioning properties and elasticity is supplied into the container lid shell body, and the melt is pressed by a mold,
Molded into a liner consisting of a central panel part and a peripheral sealing part, and while the polymer of this panel part is at a temperature above the adhesion start temperature, a flat small container is supplied to the panel part and pressed or formed. After applying a small amount of the melt of the thermoplastic polymer to the panel portion, by supplying and pressing the flat small container, surely adhere the flat small container to the panel portion,
There is an advantage that the function-separated liner having a predetermined shape and a predetermined structure can be produced as a high quality product at a high production rate.

[0022]

Preferred Embodiment of the Invention

Container Lid and Manufacturing Method Thereof In FIG. 1 (side sectional view) showing an example of the container lid according to the present invention, the container lid shell (shell) 1 is a top plate 2 and a skirt portion formed of, for example, metal or hard resin. It consists of three and three. On the inner surface side of the top plate 2, there is provided a thermoplastic polymer liner indicated as a whole by 4. The liner 4 includes a panel portion 5 and a sealing portion 6, and a flat small container 7 is thermally bonded to the panel portion 5.

The flat small container 7 contains powder particles of the oxygen scavenger, and is provided inside the sealing portion 6 so as to be exposed inside the container when sealed. The sealing portion 6 is made of a thermoplastic polymer having cushioning properties and elasticity, and is formed so as to project on the outer peripheral side of the panel portion 6 and above the panel portion. In this example, the sealing portion 6 is provided with relatively thick ring-shaped projections 8 and 8 provided on the outer peripheral portion that engages with the bottle mouth, and two ring-shaped projections 8 and 8 are provided.
A ring-shaped concave groove 9 is formed between them. Panel part 5
Is made of a thermoplastic polymer having the same cushioning property and elasticity as the sealing portion 6, and is interposed between the flat small container 7 and the shell top surface 2 to join them together, and is integrated with the sealing portion 6. ing. A coating layer (not shown) for heat-adhesion can be provided on the inner surface of the shell in order to heat-bond the melt of the polymer into the liner shape and at the same time to heat-bond it to the inner surface of the shell.

In FIG. 2 showing the enlarged internal cross-sectional structure of the flat small container 7, the flat small container 7 is filled with oxygen scavenger particles 11 between two oxygen permeable films 10 and 10. The periphery of the edge is sealed by the heat seal 10A. The oxygen absorber particles 11 may be present in the form of so-called fluid powder, but may be present in a state of being held by the porous fiber sheet 12 as illustrated. In short, if the oxygen absorber particles are accommodated in the flat small container with a large specific surface area, the oxygen that permeates into the flat small container 7 is quickly absorbed by the oxygen absorber.

When the container lid is manufactured, the flat small container 7 in which the oxygen absorber particles are sandwiched by the oxygen permeable film is manufactured in advance. A melt of a thermoplastic composition resin having cushioning properties and elasticity is supplied into the container lid shell 1, and the melt is pressed by a pressing die in the container lid shell to form a panel portion 5 and a sealing portion 6. To form a liner with. While the polymer of the panel portion 5 is at a temperature higher than the adhesion start temperature, the flat small container 7 is supplied to the panel portion and pressed, or a small amount of the melt of the thermoplastic polymer is applied to the formed panel portion 5. After applying, the flat small container 7 is supplied and pressed to bond the flat small container to the panel portion.

In FIG. 3 for explaining the steps of the method of the present invention, first, the first step (resin melt supply step)
Then, in the inside of the container lid shell 1, there is a lump 13 of molten resin.
Is supplied after being extruded from the die 15 of the extruder 14 and cut by the rotary cutter 16. Prior to supplying the resin mass 13, the shell 1 can be preheated by means such as high frequency induction heating. It is desirable that the lump 13 be in a state of being temporarily heat-bonded in the shell 1.

Then, in the second step (liner molding step), the shell 1 provided with the mass 13 of the resin melt is supplied to the pressing operation station, and the shell 1 is anvil 1.
At the same time as being supported by 7, the pressing dies 18, 19 and the sleeve 20 located above the anvil 17 descend downward. The central pressing die 18 has a size corresponding to the panel portion 5 and has a flat surface or a smooth curved surface for forming a thin liner portion, while the circumferential pressing die 19 is It has a peripheral ring-shaped recess 21 for forming a ring-shaped projection of the liner.

First, the sleeve 20 engages with the inner peripheral edge of the skirt of the shell 1 to firmly fix the shell 1, and then the pressing dies 18 and 19 descend to start pressing the molten resin mass 13. As a result, the molten resin mass 13 is rapidly spread in the radial direction, and is molded into a liner shape and adhered to the inner surface of the shell. The liner is held in this pressed state for a certain period of time.

In the third step (flat small container supply / adhesion step), while the polymer of the formed panel is still at a temperature higher than the fusion start temperature, two oxygen permeates on the liner of the shell 1. Oxygen scavenger particles are filled in spots between the conductive films, and the laminate sheet 22 having the edges thereof heat-sealed is supplied. In this example,
The laminated sheet 22 is supplied between the die cutter 23 and the punch cutter 24 located above the shell 1, and the punch cutter 24 descends to cut the sheet 22 into the flat small container 7 having a predetermined size. Punch cutter 2
4, a disc insertion rod 25 is provided so as to be able to move up and down, and the cut flat small container 7 is held at the tip and lowered, and the flat small container 7 is pressed against the panel portion 5 to heat it. Let it adhere.

In another aspect of the method of the present invention, the first step and the second step are the same as in FIG. 3, but the second step and the third step.
During the process, as shown in FIG. 4, there is an intermediate step of applying a small mass of polymer melt 26 on the panel portion of the formed liner. The melt 26 acts as an adhesive for bonding the flat small container 7 and the panel portion 5 together.

Container Lid Shell In the present invention, the material constituting the container lid shell is
Metal or plastic or a laminate of these is used. As the metal material, a sheet-shaped or foil-shaped surface-untreated steel (black plate), surface-treated steel, or a light metal such as aluminum is used. As surface-treated steel, chemical treatment such as phosphoric acid treatment and chromic acid treatment on the steel substrate; chemical conversion treatment such as electrolytic chromic acid treatment; electrolytic plating treatment such as electrolytic tin plating, electrolytic zinc plating, electrolytic chrome plating; molten aluminum Plating treatment: Examples include those subjected to hot dipping treatment such as hot tin plating. Its thickness is generally in the range of 0.15 to 0.25 mm.

The surface of these metallic materials may be coated with one or more layers of any protective coating known per se and an undercoat coating for heat-bonding a liner. Suitable examples of protective paints are phenol-epoxy paints, epoxy-
Uria paint, epoxy-melamine paint, phenol-epoxy-vinyl paint, epoxy-vinyl paint, vinyl chloride-vinyl acetate copolymer paint, vinyl chloride-vinyl acetate-maleic anhydride copolymer paint, unsaturated polyester paint, saturated One or a combination of two or more such as polyester paint. When the protective coating itself does not have adhesiveness to the thermoplastic resin for the liner used, the coating for thermal bonding of the liner, that is, the known olefin resin thermal bonding, directly on the metal material or through the above-mentioned protective coating. A paint for use, for example, a paint in which polyethylene oxide or an acid-modified olefin resin is dispersed in a film-forming resin can be applied.

These coated metal materials are molded into any container lid shape such as a crown, a pill fur proof cap, a score breaking type easy open cap with a tab, a screw cap, a lug cap and a twist off cap.
used.

On the other hand, as the resin container lid, a resin molded into a cap by means such as injection molding or press molding is used. As the molding resin, a thermoformable resin, for example, medium- or high-density polyethylene, isotactic polypropylene, ethylene-propylene copolymer, polybutene-1, ethylene-butene-1 copolymer,
Olefin resin such as propylene-butene-1 copolymer, ethylene-propylene-butene-1 copolymer, ethylene-vinyl acetate copolymer, ion-crosslinked olefin copolymer (ionomer) or blends thereof; polystyrene, Styrene-butadiene copolymer; ABS resin;
Alternatively, polycarbonate or the like can be used.

Polymer for forming liner As the thermoplastic polymer constituting the liner, a known thermoplastic polymer which can be melt-extruded and has cushioning properties and elasticity is used. Particularly, an olefin resin; for example, low-, medium -, High-density polyethylene, isotactic polypropylene, propylene-ethylene copolymer, polybutene-1, ethylene-propylene copolymer, polybutene-1, ethylene-butene-1 copolymer, propylene-butene-1 copolymer Olefin resins such as polymers, propylene-butene-1 copolymers, ethylene-propylene-butene-1 copolymers, ethylene-vinyl acetate copolymers, ion-crosslinked olefin copolymers (ionomers) or blends thereof. Blends with: ethylene-propylene copolymer rubber, ethylene-propylene -Rubber olefin-based elastomer such as diene copolymer rubber and hydrogenated ethylene-propylene-diene copolymer: SBS elastomer, butyl rubber, SBR, etc. One or more kinds of various soft plastics and elastomers can be used. ,
These are applied in the form of a melt to the shell and embossed under cooling to give a predetermined liner shape. The olefinic resin has good moldability for a liner, is excellent in sealing property, and is also excellent in retaining flavor (flavor) of content beverages.

Thermoplastic polymers particularly advantageous for the purposes of the present invention are low density polyethylene, ethylene copolymers, etc., in that they improve the liner properties and prevent orientation which adversely affects the sealability. Use of a composition in which low density polyethylene is blended with at least one of (a) an ethylene-propylene copolymer and (b) a thermoplastic elastomer, particularly a styrene-diene (butadiene or isoprene) -styrene block copolymer. It is preferable that these modifying components are contained in an amount of 3 to 40% by weight based on low density polyethylene.

The thermoplastic polymers used in the present invention include compounding agents known per se, for example, white or colored pigments such as titanium white and carbon black; calcium carbonate, white carbon,
Fillers such as clay; antioxidants; lubricants; plasticizers; antistatic agents; heat stabilizers and the like can be blended in a blending ratio known per se.

As another thermoplastic polymer forming the sealed portion, a soft vinyl chloride resin may be mentioned. This soft vinyl chloride resin was melt-extruded and press-molded, and then adhered to a flat small container, or was applied in the rotating lid shell in the form of plastisol, molded into a liner shape, and then applied to the flat small container. After that, it is heated and gelled to obtain a product.

As the vinyl chloride resin, in addition to a vinyl chloride homopolymer, vinyl chloride and a small amount of a comonomer such as vinyl acetate, vinylidene chloride, styrene, acrylic acid ester, methacrylic acid ester and butadiene can be used. Polymers can also be used. The average degree of polymerization of these vinyl chloride-based resins is not particularly limited, and generally 500 to 3000 is convenient. These vinyl chloride resins can be used for the purpose of the present invention, whether they have a relatively fine particle size by an emulsion polymerization method, relatively coarse particles by a suspension polymerization method, or a mixture thereof.

The vinyl chloride resin may of course contain a compounding agent known per se. As the plasticizer, a plasticizer generally used for vinyl chloride resins, for example, DO
Phthalates plasticizers such as P and DOB, DO
A, aliphatic dibasic acid ester plasticizer such as SOA,
One or a combination of two or more of phosphate ester-based plasticizers, hydroxy polycarboxylic acid ester-based plasticizers, fatty acid ester-based plasticizers, polyhydric alcohol ester-based plasticizers, epoxy-based plasticizers, polyester-based plasticizers, etc. Can be used in. As the stabilizer, a metal soap-based stabilizer, an organic tin-based stabilizer, an organic phosphate ester-based stabilizer, as a filler, calcium carbonate, finely divided silica, magnesium carbonate, talc, calcined clay, etc., as a pigment Titanium white,
Carbon black or the like is used, and azodicarbonamide, 4,4-oxybis (benzenesulfonyl) hydrazide or the like is used as the foaming agent, and microcrystalline wax, paraffin wax, polyethylene wax, silicone oil, fatty acid amide is used as the lubricant. System lubricants and the like. Examples of paints having strong adhesion to a vinyl chloride resin liner include vinyl chloride paints and acrylic paints.

Deoxidizer-Containing Flat Small Containers The oxygen absorber-containing flat small containers used in the present invention are opposed to each other.
An oxygen scavenger is filled between the sheets of oxygen permeable film so as not to impair the characteristics of the granular material, and the area is less than the area of the central panel portion, but the area of the central panel portion can be It is preferable to have an area as close as possible in terms of rapid oxygen absorption.

As the oxygen scavenger used in the present invention, all solid oxygen scavengers conventionally used for this kind of use can be used, but generally, a reducing one which is substantially insoluble in water is preferable. Suitable examples thereof include metal powder having a reducing property, such as reducing iron, reducing zinc, reducing tin powder;
Low-grade metal oxides such as ferrous oxide, ferrosoferric oxide, and reducing metal compounds such as iron carbide, silicon iron, iron carbonyl, iron hydroxide; These are alkali metal, alkaline earth metal hydroxides, carbonates, sulfites, thiosulfates, tertiary phosphates, dibasic phosphates, organic acid salts, halides as necessary. Further, it can be used in combination with an auxiliary agent such as activated carbon, activated alumina or activated clay. Further, a polymer compound having a polyhydric phenol in the skeleton, for example, a polyhydric phenol-containing phenol / aldehyde resin and the like can be mentioned.

These oxygen absorber particles generally have a particle size of 200 μm.
It is preferable to have a particle diameter of m or less, particularly 100 μm or less in order to improve the oxygen absorption rate. That is, if the particle size is larger than the above range, the surface area is decreased, and as a result, the oxygen absorption rate is decreased, which is not preferable. As already pointed out, the oxygen scavenger particles can be held in a porous sheet or the like and held in the film in this state.

On the other hand, as the oxygen permeable film, a resin film having a large oxygen permeability, particularly an olefin resin; for example, low-, medium-, high-density polyethylene, isotactic polypropylene, propylene-ethylene copolymer, polybutene -1, ethylene-propylene copolymer,
Polybutene-1, ethylene-butene-1 copolymer, propylene-butene-1 copolymer, propylene-butene-1
A film made of a copolymer, an ethylene-propylene-butene-1 copolymer, an ethylene-vinyl acetate copolymer, an ion-crosslinked olefin copolymer (ionomer), a blend thereof or the like is advantageously used. These films are generally 20 to 100 μm, especially 20 to 5 μm.
It is preferable to have a thin thickness of 0 μm from the viewpoint of oxygen permeability. These films are preferably water-permeable by means of electric discharge machining, micro-foaming, foaming and stretching, but are preferably porous so as to have air permeability. It should be understood that when the film is thin and lacks in shape retention, a laminate having the film as an outer layer and the inner layer as a porous sheet can be used.

The thermoplastic polymer particles constituting the oxygen permeable film may be the same kind or different kinds as the polymer constituting the liner, but a combination having a heat adhesive property between them is selected. Are generally preferred. From this point of view, it is preferable to select an oxygen permeable film in which the constitutional units of the main polymers are common. The combination of the olefin resin oxygen-permeable film and the olefin resin liner is very satisfactory in this respect.

The content of the oxygen absorber particles also depends on the head space volume in the container. Generally 50 to 500 mg / 100 m of oxygen absorber particles per headspace volume
It is advisable to use it in an amount of 1, especially 100 to 300 mg / 100 ml. If the amount of the oxygen scavenger particles is less than the above range, the oxygen absorption rate and oxygen absorption capacity will be inferior to those within the above range, while even if it is more than the above range, further increase in the effect. Can not be expected and is economically disadvantageous.

The amount of the liner-forming thermoplastic polymer to be supplied into the shell of the container lid varies depending on the size of the shell, but can be generally set within the range of 100 mg to 10 g.

The present invention will be specifically described by the following examples.

【Example】

Example 1 The periphery of a porous film made of LLDPE and the film made of LDPE was fused by heat sealing, and the inside was 1.5 c.
A flat small container having a non-bonded portion of m * 1.5 cm and containing 0.1 g of reducing iron powder as an oxygen scavenger was prepared. Furthermore, after supplying the LDPE-based melt that forms the panel portion and the peripheral sealing portion into the container lid shell, the flat small container is inserted onto the melt so that the porous film is on the upper surface and pressed. And adhered to each other to prepare a container lid with an oxygen absorbing liner.

For comparison, an LDPE resin and reducing iron powder were melt-mixed, a disc having a diameter of 25 mm was produced, and then a container lid with an oxygen-absorbing liner adhered to a liner panel was produced (comparative product (2 )).

The oxygen absorption performances of the product of the present invention and the comparative product were measured by filling a glass bottle having a volume of 1 liter with water so that the headspace was 80 cc, and hermetically storing it in a container lid of the product of the present invention and the comparative product. The oxygen concentration inside was measured over time. Table 1 shows the measurement results.

[0052]

[Table 1]

As described above, the product of the present invention was remarkably superior in oxygen absorption performance to the comparative product. Further, as a comparative product (2), a flat small container similar to that of the present example was prepared, and a liner composed of an LDPE resin panel portion and a peripheral portion was molded and solidified by cooling, and then the flat small container and the liner were bonded with an adhesive. Bonded through.

Although the oxygen absorption performance of this comparative product was equivalent to that of the product of the present invention, this comparative product had a weak bonding force and peeled easily.

Further, since the container lid is used after being sterilized with Oxonia, the residual concentration after sterilization was measured by the following method. 1. Sterilization 3% Oxonia active was sprayed for 3 minutes. 2. Extraction 40 ml of the extract was put in a 1.5-liter PET bottle and sealed with a container lid after sterilization. Then, it was shaken vigorously for 30 seconds. 3. Measurement The H ₂ O ₂ concentration in the extract was measured using a H ₂ O ₂ analyzer (Orientator Model III, manufactured by Oriental Electric Co., Ltd.). The measurement results are shown in Table 2.

[0056]

[Table 2] As described above, in this comparative product (2), a gap was formed between the panel portion and the flat small container, so that oxonia remained in that portion and had an offensive odor.

[0057]

According to the present invention, as the oxygen scavenger to be applied to the inside of the container lid shell, an oxygen permeable film is formed, and the oxygen absorber in the form of powder or granules is filled in the oxygen scavenger and has a size that covers most of the central panel. By selecting and using a flat small container type that has a large thickness, the oxygen absorber has a large specific surface area, and since the film is oxygen permeable, it quickly remains in the headspace or the contents. It can absorb and remove oxygen. Further, since the oxygen absorber particles are housed in the flat small container, not only is it easy to handle as a single component, but the oxygen absorber particles are released in the form of powder and become a member of the container lid. There is no problem of adhesion or contamination of the contents.

Further, a melt of a thermoplastic polymer having a cushioning property and elasticity is supplied into the container lid shell, and the melt is pressed by a mold to comprise a central panel portion and a peripheral sealing portion. It is molded into a liner, and while the polymer of the panel part is at a temperature higher than the sticking onset temperature, a flat small container is supplied to the panel part and pressed, or a melt of the thermoplastic polymer is formed on the formed panel part. After applying a small amount of the flat small container and pressing it, the flat small container is adhered to the central panel part on the entire back surface of the flat small container by using the in-molding process of the liner container lid shell. The oxygen absorber particle-containing flat small container can be firmly and surely heat-bonded to the central panel portion of the liner over the entire back surface thereof. This thermal bonding will withstand the hot filling of the contents and the heat during the retort sterilization or the attack by the contents, and the flat small container containing the oxygen absorber particles and the panel portion of the liner will adhere to each other without any gap. Therefore, even when the container lid is sterilized in advance during aseptic filling, the sterilizing solution does not remain in the gap between the small container containing the oxygen absorber particles and the panel portion of the liner, and the flavor retention of the contents is maintained. It also has the advantage of being excellent.

Further, according to the method of the present invention, the oxygen permeable film on the front side is melted because the small heat of the central panel part in the middle of molding or the melt blobs of the polymer supplied separately is utilized. Without being carried out, the oxygen absorber particles are maintained as they are, and the oxygen absorber particles are less likely to be implanted in the polymer, and the original excellent oxygen absorption performance is exhibited. Furthermore, the flat small container containing the oxygen scavenger is provided on the liner so as to cover most of the panel portion inside the sealing portion, so that the oxygen scavenging is not affected in the range that the sealing property of the liner is not affected. The flat small container containing the agent particles can be exposed in the sealed container in the maximum area, whereby the deoxidizing action can be sufficiently exerted.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an example of a container lid according to the present invention.

FIG. 2 is an enlarged view showing an enlarged internal cross-sectional structure of a flat small container.

FIG. 3 is an explanatory diagram for explaining the steps of the method of the present invention, wherein the first step is a resin melt supply step, the second step is a liner molding step, and the third step is a flat small container supply and adhesion step. .

FIG. 4 is an illustration showing an intermediate step of applying a small mass of polymer melt onto the panel portion of the formed liner.

[Explanation of symbols]

1 is a container lid shell (shell), 2 is a top plate, 3 is a skirt portion, 4 is a thermoplastic polymer liner, 5 is a panel portion, 6
Is a sealed portion, 7 is a small flat container, 8 is a ring-shaped projection having a relatively thick wall, 9 is a ring-shaped groove, and 10 is an oxygen permeable film 1.
0 and 11 are oxygen absorber particles, 10A is heat seal, 12
Is a porous fiber sheet, 13 is a block of molten resin, and 14 is
Is an extruder, 15 is a die, 16 is a rotary cutter, 17 is an anvil, 18 and 19 are pressing dies, 20 is a sleeve, 2
1 is a ring-shaped recess, 22 is a laminated sheet, 23 is a die cutter, 24 is a punch cutter, 25 is a disc insertion rod, and 26 is a small mass of polymer melt.

Claims (3)

[Claims] 1. A container lid shell is provided with a melt of a thermoplastic polymer having cushioning properties and elasticity, and the melt is pressed by a mold to comprise a central panel portion and a peripheral sealing portion. Molded into a liner, while the polymer of the panel section is at a temperature above the sticking start temperature, it consists of an oxygen permeable film, is filled with a granular oxygen scavenger and most of the central panel section A method for producing a container lid with an oxygen-absorbing liner, characterized in that a flat small container having a size covering the above is supplied to a panel portion and pressed, and the entire back surface of the flat small container is adhered to a central panel portion. 2. A container lid shell is supplied with a melt of a thermoplastic polymer having cushioning properties and elasticity, and the melt is pressed by a mold to comprise a central panel portion and a peripheral sealing portion. Molded into a liner, applied a small amount of thermoplastic polymer melt to the formed panel part, consisting of an oxygen permeable film, filled with a granular oxygen scavenger, and large in the central panel part. A container with an oxygen-absorbing liner, characterized in that a flat small container having a size that covers the portion is supplied to the panel portion and pressed, and is adhered to the central panel portion on the entire back surface of the flat small container through the melt. How to make a lid. 3. The method for producing a container lid with an oxygen-absorbing liner according to claim 1, wherein the thermoplastic resin forming the liner and the thermoplastic resin forming the oxygen-permeable film are heat-sealable resins of the same kind. .