JP2650576B2 - Manufacturing method of container lid with oxygen-absorbing liner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a container lid with a liner having a high oxygen absorption, and more particularly, it has a combination of a sealing property and a high oxygen absorption and is easy to manufacture. And a method for producing a container lid with a liner.

[0002]

2. Description of the Related Art In the manufacture of a sealed package such as a bottle, 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, it is generally known to blow water vapor or nitrogen gas into a bottle filled with the contents to replace the air in the headspace with these gases and then plug the lid. ing. 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 an oxygen absorbent for a lid or the like is already known. For example, there is a container lid made of a metal shell and a gasket or liner provided inside the shell, in which an oxygen absorbent is blended into a resin such as the gasket. The oxygen absorbent in the container lid liner or gasket will eventually absorb and remove residual oxygen in the headspace or contents.

Japanese Patent Application No. 3-88 proposed by the present inventors.
No. 592 provides a layer of an oxygen-absorbing resin composition in which an oxygen-absorbing agent is blended in a resin liner or a packing, and the surface of the oxygen-absorbing resin composition layer on the inner surface side of the container has a sealing portion. It has been proposed to improve the oxygen absorption rate by forming minute irregularities over almost the entire surface on the center side.

[0006]

The oxygen-absorbing agent-containing liner disclosed in the above proposal has a certain improvement in the oxygen absorption rate. However, the liner in the container immediately after stoppering until the contents are sterilized or sterilized. However, the ability to remove residual oxygen in a range that does not affect the flavor and the like has not been sufficiently satisfactory. It is known that the flavor retention of the contents (flavor retention) is closely related to the residual oxygen concentration in the container, and is further damaged by heating during sterilization or sterilization. Therefore, an oxygen-absorbing agent-containing liner capable of removing residual oxygen in a container within a short time after stoppering is desired.

SUMMARY OF THE INVENTION It is an object of the present invention to quickly remove residual oxygen in a container, thereby preventing deterioration of contents and flavor, and to reduce flavor by providing an oxygen scavenger in a container lid. It is an object of the present invention to provide a method for manufacturing a container lid in which problems such as functional deterioration are eliminated. Another object of the present invention is that the structure is simple, the production is easy, and the initial absorption rate of the residual oxygen in the container is excellent, and the attachment of the oxygen absorber to the container lid is also easy and reliable. It is an object of the present invention to provide a method for manufacturing a container lid.

It is still another object of the present invention to provide a method for producing a function-separated liner that exhibits a high oxygen absorption function without impairing the sealing performance.
Another object of the present invention is to provide a method capable of producing the above-mentioned container lid with a function-separated type 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 fed into a container lid shell, and the melt is pressed by a mold to form a center. Into a liner consisting of a panel part and a surrounding sealing part. While the polymer of the panel part is at a temperature equal to or higher than the temperature at which adhesion starts, the panel part is formed of an oxygen-permeable film, and a powdery granular material is formed inside. A flat small container filled with an oxygen agent and having a size that covers most of the central panel portion is supplied to the panel portion and pressed, using the heat of the central panel in the middle of molding,
Deoxidation without melting the front oxygen permeable film
A method for producing a container lid with an oxygen-absorbing liner, characterized in that the base particles are welded to the central panel over the entire back surface without being substantially implanted in the polymer .

According to the present invention, a melt of a thermoplastic polymer having cushioning properties and elasticity is supplied into a container lid shell, and the melt is pressed by a mold to form a central panel portion and a peripheral portion. It is molded into a liner consisting of a sealing part, a small amount of a thermoplastic polymer melt is applied to the panel part to be formed, an oxygen-permeable film is formed, the inside of which is filled with a particulate oxygen absorber and the center is formed. A small flat container having a size to cover most of the panel section is supplied to the panel section, pressed, and supplied separately.
Utilizing the heat of the polymer melt lumps,
Oxygen permeable film without melting and oxygen absorber particles
The present invention provides a method for producing a container lid with an oxygen-absorbing liner, wherein a child is welded to a central panel over the entire back surface without being substantially implanted in a polymer .

[0011]

According to the present invention, an oxygen permeable film is used as an oxygen scavenger to be applied to the inside of the container lid shell, and the inside of the container is filled with a particulate oxygen absorber and covers a large part of the central panel. Select and use a flat small container type.

The reason why the liner using the layer in which the oxygen scavenger is dispersed in the resin is inferior in the rapid absorption of oxygen is that the surface of the oxygen scavenger particles is covered with the resin and the oxygen absorption by the oxygen scavenger particles is reduced. It is considered that absorption is affected by the diffusion rate of oxygen in the resin. That is, in the deoxidizer particle dispersion system in the resin, the diffusion rate of oxygen in the resin is the rate-determining stage,
For this reason, the oxygen absorption rate becomes slow.

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

In the present invention, a flat small container made of an oxygen-permeable film and filled with a particulate oxygen absorber is used. In this flat container, the oxygen scavenger exists as particles independent of each other and with a very large specific surface area. The oxygen scavenger particles are contained in a flat small container, but since the film constituting the container is permeable to oxygen, the difference in oxygen partial pressure inside and outside the film causes oxygen outside the small container to fall on the film wall. , And the permeated oxygen is immediately adsorbed by the oxygen scavenger particles and removed by the reaction. Of course, if the film has micropores through which gas can permeate, oxygen can flow into the small container more quickly through the micropores, and oxygen can be absorbed more quickly.

Thus, according to the present invention, oxygen flows in through the oxygen-permeable film, and oxygen is absorbed from the surface of the oxygen-absorbing agent particles. Oxygen remaining in the head space or contents can be quickly absorbed and removed without being affected by diffusion of oxygen.

Further, since the oxygen scavenger particles are housed in a flat small container, not only is it easy to handle as a single component, but also the oxygen scavenger particles are liberated in the form of a powder and the container lid is released. There is no problem that it adheres to the member or mixes with 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. While the polymer of the panel portion is at a temperature equal to or higher than the adhesion initiation temperature, the flat small container is supplied to the panel portion and pressed, or the formed panel portion is made of a thermoplastic polymer. It is a remarkable feature that the flat small container is supplied and pressed after a small amount of the melt is applied, so that the flat small container is adhered to the central panel on the entire back surface of the flat small container. In the present specification, the temperature at which the polymer starts to stick is defined as the temperature at which the endothermic peak of the polymer melts in the differential thermal analysis.

According to the method of the present invention, the flat small container containing the oxygen-absorbing particles is firmly and reliably heated to the central panel portion of the liner over the entire back surface thereof by utilizing the step of forming the liner inside the container lid shell. Can be glued. That is, since the oxygen-permeable film constituting the flat small container has a relatively small heat capacity, the oxygen-permeable films are welded to each other by the heat of the central panel portion in the middle of molding or the separately supplied small polymer melt. This thermal bonding withstands the heat or the attack by the contents at the time of hot filling and retort sterilization of the contents. Further, in the container lid according to the present invention, since the flat small container containing the oxygen scavenger particles and the panel portion of the liner are in close contact with each other without any gap, in aseptic filling,
Even when the container lid is previously sterilized, there is also an advantage that the sterilizing solution does not remain in the gap between the oxygen-absorbing particle-containing small container and the panel portion of the liner, and the content has excellent flavor retention. .

Further, according to the method of the present invention, since the small heat of the middle panel portion during molding or the separately supplied small polymer melt is utilized, the oxygen permeable film on the front side is melted. In addition, the oxygen absorbing agent particles are maintained as they are, and there is little tendency for the oxygen scavenger particles 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 sealing performance of the liner is not affected. , A flat small container containing oxygen scavenger particles,
It can be exposed in the container after sealing with a maximum area, so that the deoxidizing action can be sufficiently exerted. On the other hand, a thermoplastic polymer having cushioning properties and elasticity is present on the outer peripheral side of the panel portion so as to protrude upward from the panel portion and forms a sealing portion, so that excellent sealing performance is obtained. In addition to being obtained stably over time, this cushioning thermoplastic resin also exists as a lower layer under the panel part, and the overall structure is integrated, It is also a liner with excellent bonding structure. In the sealed storage state of the container, an oxygen permeation path from the outside of the container to the inside of the container through the sealing portion and the panel portion becomes a problem, but the container lid according to the present invention effectively captures such permeated oxygen. be able to.

In producing the liner, 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.
It is 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 equal to or higher than 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 thermoplastic polymer melt to the panel portion to be supplied, by supplying and pressing the flat small container, the flat small container is securely adhered to the panel portion,
There is an advantage that the function-separable type liner having a predetermined shape and a predetermined structure can be produced at a high production rate as a high quality one.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION

Container Lid, Method for Producing the Same In FIG. 1 (side sectional view) showing an example of a container lid according to the present invention, a container lid shell (shell) 1 includes a top plate 2 and a skirt portion made of, for example, metal or hard resin. It consists of three. On the inner surface side of the top plate 2, a thermoplastic polymer liner indicated as a whole by 4 is provided. 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 a powder of an oxygen scavenger, and is provided inside the sealing portion 6 so as to be exposed to the inside of 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 protrude on the outer peripheral side of the panel portion 6 and above the panel portion. In this embodiment, the sealing portion 6 has relatively thick ring-shaped protrusions 8 provided on the outer peripheral portion to be engaged with the bottle mouth, and the two ring-shaped protrusions 8 are provided.
A ring-shaped groove 9 is formed therebetween. Panel part 5
Is made of a thermoplastic polymer having cushioning and elasticity similarly to 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 also integrated with the sealing portion 6. ing. A heat bonding coating layer (not shown) may be provided on the inner surface of the shell so that the melt of the polymer is heat-bonded to the inner surface of the shell at the same time as the liner shape is pressed.

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

In manufacturing the container lid, a flat small container 7 in which oxygen scavenger particles are sandwiched in advance by an oxygen permeable film is manufactured. A melt of a thermoplastic resin having cushioning property and elasticity is supplied into the container lid shell 1, and the melt is pressed with a pressing mold in the container lid shell to form a panel unit 5 and a sealing unit 6. Into a liner with While the polymer of the panel portion 5 is at a temperature equal to or 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 thermoplastic polymer melt is applied to the formed panel portion 5. Then, the flat small container 7 is supplied and pressed to bond the flat small container 7 to the panel portion.

In FIG. 3 for explaining the steps of the method of the present invention, first, a first step (a resin melt supply step)
The inside of the container lid shell 1 contains a lump of molten resin 13.
Is supplied through extrusion from a die 15 of an extruder 14 and cutting by a rotary cutter 16. Prior to the supply of the resin mass 13, the shell 1 can be preheated by means such as high-frequency induction heating. The lump 13 is desirably in a state of being preliminarily thermally bonded in the shell 1.

Next, in a second step (liner molding step), the shell 1 provided with the resin melt lump 13 is supplied to the pressing operation station, and the shell 1 is placed on the anvil 1
At the same time as being supported by 7, the dies 18, 19 and the sleeve 20 located above the anvil 17 are lowered. The central stamping die 18 has dimensions corresponding to the panel part 5 and has a flat surface or a smooth curved surface for forming a thin liner portion, while the peripheral stamping die 19 has And a ring-shaped concave portion 21 on the periphery for forming a ring-shaped projection of the liner.

First, after the sleeve 20 is engaged with the inner peripheral edge of the skirt of the shell 1 and the shell 1 is firmly fixed, 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 formed 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 bonding step), while the polymer of the formed panel portion is still at a temperature higher than the fusion start temperature, two sheets of oxygen permeated on the liner of the shell 1 The oxygen-absorbing particles are filled in spots between the conductive films, and a laminate sheet 22 whose periphery is heat-sealed is supplied. In this specific example,
The laminate sheet 22 is supplied between a die cutter 23 and a punch cutter 24 located above the shell 1, and the punch cutter 24 descends to cut the sheet 22 into a small flat container 7 having a predetermined size. Punch cutter 2
A disc insertion rod 25 is provided coaxially with the disc holder 4 so as to be able to move up and down. The disc holder 7 is moved downward while holding the cut flat small container 7 at the tip, and presses the flat small container 7 against the panel unit 5 to generate heat. Adhere.

In another embodiment of the method of the present invention, the first and second steps are the same as in FIG.
Between the steps, there is an intermediate step of applying a small mass 26 of polymer melt on the panel portion of the formed liner, as shown in FIG. The melt 26 acts as an adhesive for bonding the flat small container 7 and the panel unit 5.

Container lid shell In the present invention, the material constituting the container lid shell includes:
Metal, plastic, or a laminate thereof is used. As the metal material, a sheet-shaped or foil-shaped untreated surface steel (black plate), surface-treated steel, or light metal such as aluminum is used. As the surface-treated steel, chemical treatment such as phosphoric acid treatment and chromic acid treatment; chemical conversion treatment such as electrolytic chromic acid treatment; electrolytic plating treatment such as electrolytic tin plating, electrolytic zinc plating and electrolytic chromium plating; Plating treatment: A treatment which has been subjected to a hot-dip plating process such as a hot-dip tin plating process may be mentioned. Its thickness should generally be in the range of 0.15 to 0.25 mm.

The surface of these metal materials may be coated with one or two or more layers of any known protective coating and undercoat for thermal bonding of the liner. Suitable examples of protective paints are phenol-epoxy paints, epoxy-
Urea 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 paints. When the protective coating itself does not have an adhesive property to the thermoplastic resin for the liner used, the coating for thermal bonding of the liner directly on the metal material or through the protective coating described above, that is, a known olefin resin thermal bonding Paint, for example, a paint in which polyethylene oxide or an acid-modified olefin resin is dispersed in a film-forming resin.

These coated metal materials are formed into an arbitrary container lid shape such as a crown, a pill fur proof cap, a score breakable easy open cap with a tab, a screw cap, a lug cap, a twist off cap, and the like.
used.

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

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; -, High-density polyethylene, isotactic polypropylene, propylene-ethylene copolymer, polybutene-1, ethylene-propylene copolymer, polybutene-1, ethylene-butene-1 copolymer, propylene-butene-1 copolymer Olefinic resins such as polymers, propylene-butene-1 copolymer, ethylene-propylene-butene-1 copolymer, ethylene-vinyl acetate copolymer, ion-crosslinked olefin copolymer (ionomer) or blends thereof Blend with: ethylene-propylene copolymer rubber, ethylene-propylene -Rubber olefin-based elastomers such as diene copolymer rubber and hydrogenated ethylene-propylene-diene copolymer: One or more kinds of soft plastics and elastomers such as SBS elastomer, butyl rubber and SBR can be used. ,
These are applied to the shell in the form of a melt and are embossed under cooling to a predetermined liner shape. The olefin-based resin has good moldability into a liner, has excellent sealing properties, and further has excellent flavor (flavor) retention properties of content beverages and the like.

Particularly advantageous thermoplastic polymers for the purposes of the present invention are low-density polyethylenes, ethylene-based copolymers, etc., in terms of improving liner properties and preventing orientation which adversely affects sealing. Use of a composition obtained by blending at least one of (a) an ethylene-propylene copolymer and (b) a thermoplastic elastomer, particularly a styrene-diene (butadiene or isoprene) -styrene block copolymer, with low-density polyethylene. Preferably, these modifying components are contained in an amount of 3 to 40% by weight based on the low density polyethylene.

The thermoplastic polymer used in the present invention may contain known additives such as white or colored pigments such as titanium white and carbon black; calcium carbonate, white carbon, and the like.
A filler such as clay; an antioxidant; a lubricant; a plasticizer; an antistatic agent; a heat stabilizer and the like can be blended at a blending ratio known per se.

As another thermoplastic polymer forming the sealing portion, a soft vinyl chloride resin can be mentioned. This soft vinyl chloride resin was melt-extruded and pressed and formed, and then a flat small container was adhered or applied to a rotating lid shell in the form of a plastisol, and after forming into a liner shape, the flat small container was applied. Then, it is heated and gelled to obtain a product.

Examples of the vinyl chloride resin include not only a homopolymer of vinyl chloride, but also a copolymer of vinyl chloride with a small amount of a comonomer such as vinyl acetate, vinylidene chloride, styrene, acrylate, methacrylate and butadiene. Polymers can also be used. The average degree of polymerization of these vinyl chloride 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 either in a relatively fine particle size by an emulsion polymerization method, in a relatively coarse particle size by a suspension polymerization method, or in 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 a vinyl chloride resin, for example, DO
Phthalate plasticizers such as P and DOB, DO
A, an aliphatic dibasic ester plasticizer such as SOA,
One or a combination of two or more of a phosphate ester plasticizer, a hydroxy polycarboxylic acid ester plasticizer, a fatty acid ester plasticizer, a polyhydric alcohol ester plasticizer, an epoxy plasticizer, and a polyester plasticizer. Can be used. As stabilizers, metal soap-based stabilizers, organotin-based stabilizers, organic phosphate ester-based stabilizers, as fillers, calcium carbonate, finely divided silica, magnesium carbonate, talc, calcined clay, etc., as pigments, Titanium white,
Carbon black and the like are used as foaming agents, such as azodicarbonamide and 4,4-oxybis (benzenesulfonyl) hydrazide. As lubricants, microcrystalline wax, paraffin wax, polyethylene wax, silicone oil, fatty acid amide are used. And the like. In addition, as a paint exhibiting strong adhesiveness to a vinyl chloride resin liner, a vinyl chloride paint or an acrylic paint can be used.

Flat container containing oxygen scavenger The flat container containing oxygen scavenger used in the present invention has two opposed flat containers.
An oxygen-absorbing agent is filled between the two oxygen-permeable films so that the properties of the granules are not impaired.The area is less than the area of the central panel, but it can be increased by the area of the central panel. 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 application can be used, but generally, those which are reducible and substantially insoluble in water are preferable. Suitable examples thereof include reducing metal powders such as reducing iron, reducing zinc, and reducing tin powder;
Low-metal oxides such as ferrous oxide and triiron tetroxide, as well as reducing metal compounds such as iron carbide, silicon iron, iron carbonyl and iron hydroxide; These are, if necessary, an alkali metal, alkaline earth metal hydroxide, carbonate, sulfite, thiosulfate, tertiary phosphate, secondary phosphate, organic acid salt, halide. Activated carbon, activated alumina and activated clay can also be used in combination. Further, a high molecular compound having a polyhydric phenol in the skeleton, for example, a phenol-aldehyde resin containing a polyhydric phenol may be used.

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

On the other hand, examples of the oxygen-permeable film include resin films having high oxygen permeability, particularly olefin resins; for example, low-, medium-, and high-density polyethylene, isotactic polypropylene, propylene-ethylene copolymer, and 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) or a blend thereof is advantageously used. These films are generally from 20 to 100 μm, in particular from 20 to 5 μm.
It is preferable to have a thin thickness of 0 μm from the viewpoint of oxygen permeability. These films do not have water permeability by means of electric discharge machining, microfoaming, foam stretching and the like, but are preferably porous so as to have air permeability. It should be understood that when the film is thin and lacks 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 or different from the polymer constituting the liner. Is generally preferred. From such a viewpoint, it is preferable to select an oxygen-permeable film having a common constitutional unit of the main polymer. The combination of an olefin resin oxygen permeable film and an olefin resin liner is very satisfactory in this regard.

The content of oxygen scavenger particles also depends on the headspace volume in the vessel. Generally, 50 to 500 mg / 100 m2 of oxygen absorber particles per headspace volume
l, 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 in the above range, while if it is larger than the above range, the effect will be further increased. Cannot be expected, which is disadvantageous economically.

The amount of the liner-forming thermoplastic polymer to be supplied into the container lid shell varies depending on the size of the shell, but can be appropriately determined generally in 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 a film made of LDPE were fused by heat sealing, and the inside was 1.5 c
A flat small container having an m * 1.5 cm non-adhesive portion and containing therein 0.1 g of reducing iron powder as an oxygen scavenger was prepared. Further, after supplying the LDPE-based melt that forms the panel portion and the surrounding sealing portion in the container lid shell, the flat small container is inserted into the melt so that the porous film faces upward, and pressed. To make a container lid with an oxygen-absorbing liner.

As a comparison, after a LDPE resin and a reducing iron powder were melt-mixed, a disk having a diameter of 25 mm was prepared, and a container lid with an oxygen-absorbing liner bonded to a liner panel was prepared (Comparative product (2) )).

The oxygen absorption performance of the product of the present invention and the comparative product was determined by filling a glass bottle having a capacity of 1 liter with water so that the head space became 80 cc, and sealingly storing the container with the lid of the product of the present invention and the comparative product. The oxygen concentration in the sample 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 comprising a panel portion and a peripheral portion made of LDPE resin was molded and solidified by cooling. Were joined through

The oxygen absorption performance of this comparative product was equivalent to that of the present invention product, but this comparative product was weak in bonding strength and easily peeled off.

Further, since the container lid is used after sterilization with oxonia or the like, 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 placed in a 1.5 liter PET bottle, and sealed with a container lid after sterilization. Thereafter, it was vigorously shaken for 30 seconds. 3. Measurement The H ₂ O ₂ concentration in the extract was measured using an H ₂ O ₂ analyzer (Oriental Model III, manufactured by Oriental Electric). Table 2 shows the measurement results.

[0056]

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

[0057]

According to the present invention, an oxygen permeable film is used as a deoxidizing agent to be applied to the inside of the container lid, and the inside of the container is filled with a powdery deoxidizing agent and covers a large part of the central panel. By selecting and using a flat, small container type with a high degree of oxygen, the oxygen absorber has a large specific surface area, and since the film is permeable to oxygen, it quickly remains in the headspace or contents. Oxygen can be absorbed and removed. In addition, since the oxygen scavenger particles are housed in a small flat container, not only is it easy to handle as a single component, but also the oxygen scavenger particles are liberated in the form of a powder, which is used as a member for the container lid. There is no problem that it adheres or mixes into the contents.

Further, 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. It is molded into a liner, and while the polymer in the panel is at a temperature equal to or higher than the adhesion start temperature, a flat small container is supplied to the panel and pressed, or a thermoplastic polymer melt is applied to the formed panel. After applying a small amount of the flat small container, the flat small container is supplied and pressed, and the flat small container is adhered to the central panel portion on the entire back surface of the flat small container. In addition, the flat small container containing the oxygen scavenger particles can be firmly and reliably thermally bonded to the central panel portion of the liner on the entire back surface. This thermal bonding can withstand the heat of the contents and the attack by the heat or the contents at the time of retort sterilization, and the flat small container containing the oxygen scavenger particles and the panel part of the liner adhere to each other without gaps. Therefore, even when the container lid is previously sterilized during aseptic filling, the sterilizing solution does not remain in the gap between the oxygen-absorbing particle-containing small container and the panel portion of the liner, and the content retains the flavor. It also has the advantage of being superior.

Further, according to the method of the present invention, the oxygen-permeable film on the front side is melted by utilizing the small heat of the central panel part in the middle of molding or the small melt of the polymer supplied separately. In addition, the oxygen absorbing agent particles are maintained as they are, and there is little tendency for the oxygen scavenger particles to be implanted in the polymer, and the original excellent oxygen absorption performance is exhibited. Further, by providing the oxygen absorber-containing flat small container on the liner so as to cover most of the panel portion inside the seal portion, the oxygen deoxidation is within a range that does not affect the sealability of the liner. The agent container-containing flat small container can be exposed with a maximum area in the container after sealing, whereby the deoxidizing effect can be sufficiently exerted.

[Brief description of the 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 the flat small container.

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

FIG. 4 is an explanatory view showing an intermediate step of applying a small block of a polymer melt on a panel portion of a formed liner.

[Explanation of symbols]

1 is a container lid shell, 2 is a top plate, 3 is a skirt, 4 is a thermoplastic polymer liner, 5 is a panel, 6
Is a sealed portion, 7 is a flat small container, 8 is a relatively thick ring-shaped protrusion, 9 is a ring-shaped groove, 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 lump of molten resin, 14
Is an extruder, 15 is a die, 16 is a rotary cutter, 17 is an anvil, 18 and 19 are press dies, 20 is a sleeve, 2
1 is a ring-shaped recess, 22 is a laminate 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 (2)

(57) [Claims] 1. A melt of a thermoplastic polymer having cushioning properties and elasticity is supplied into a container lid shell, and the melt is pressed by a mold to form a central panel portion and a peripheral sealing portion. It is formed into a liner, and while the polymer in the panel portion is at a temperature equal to or higher than the temperature at which sticking starts, it is formed of an oxygen-permeable film, the inside of which is filled with a particulate oxygen absorber, and the center panel portion is large. The flat small container having a size to cover the part is supplied to the panel part and pressed, and the central panel in the middle of molding has
To melt the oxygen-permeable film on the front side using heat
Virtually without oxygen absorber particles implanted in the polymer
A method for producing a container lid with an oxygen-absorbing liner, characterized in that the entire rear surface is welded to the central panel without being damaged . 2. A melt of a thermoplastic polymer having cushioning properties and elasticity is supplied into a container lid shell, and the melt is pressed by a mold to form a central panel portion and a peripheral sealing portion. Molded into a liner, apply a small amount of thermoplastic polymer melt to the panel part formed, consist of an oxygen permeable film, filled with a particulate oxygen absorber inside and most of the central panel part A flat small container having a size to cover the panel unit is pressed and pressed, and a polymer melt supplied separately is supplied.
Utilizing the heat of small lumps, the oxygen-permeable film on the front side
And the oxygen scavenger particles are substantially contained in the polymer without melting
Above without implanted, soluble in the central panel portion with the entire back surface
The oxygen-absorbing container cap of the process with a liner, characterized in that to wear.