TWI451970B - Multi-layered sheet, container and packaging article - Google Patents

Description

Multilayer sheet, container and package

The present invention relates to a multilayer sheet, a container formed by using the multilayer sheet, and a package formed using the container.

Previously, in the processing of aquatic products or design, etc. As for the manufacturer, the metal can is used as a container.

As far as the strength of metal cans is concerned, (1) liquid, gas, and light are highly cut off, and can be stored for a long time (more than one year); (2) good thermal and electrical conductivity, heating. (3) Because it is strong and rigid, it can be loaded in a large amount and in a large amount; (4) It can perform high-temperature and high-precision forming processing at room temperature.

On the other hand, in terms of the shortcomings of the metal can, it can be exemplified: (1) Since the specific gravity is heavy and heavy, it is transported. Difficult to operate; (2) Because the metal reacts with the contents and external moisture, it needs anti-corrosion measures; (3) the shape of the container is certain (for example, cylindrical), which makes consumers tired; (4) the content is completely invisible, There is a possibility of causing consumer anxiety.

Furthermore, in addition to such problems, and due to the emphasis on environmental issues in recent years, the number of manufacturers focusing on demetallization is increasing.

For example, Japanese Laid-Open Patent Publication No. 2000-25731 discloses a technique in which a gas barrier layer is provided on a laminate composed of a resin, and the sealing property is improved by coating the end portions of the gas barrier layer.

However, in the aforementioned Document 1, although the sealing property is somewhat improved, the oxygen barrier property sufficient to achieve the substitution degree of the metal can is not achieved.

Accordingly, an object of the present invention is to provide a multilayer sheet, a container, and a package which have an oxygen barrier property equivalent to that of a metal can, and which have an easy-opening property, a sealing property, and heat resistance.

The multilayer sheet of the present invention is characterized in that it comprises a base material layer and an outermost layer laminated on one side of the base material layer; and the outermost layer is formed of at least three layers, and comprises: a moisture absorbing adhesive layer disposed on a side in contact with the substrate layer; a barrier layer disposed on an opposite side of the moisture absorbing adhesive layer from the substrate layer; and a polyolefin layer disposed on the barrier layer The aforementioned moisture absorbing the opposite side of the adhesive layer.

The multilayer sheet of the present invention is formed by a base material layer and an outermost layer, and in the case where the multilayer sheet is a container, the base material layer is formed so as to be located on the side of the contents. Further, the outermost layer is formed of at least three layers so as to be a moisture absorbing adhesive layer on the side in contact with the substrate layer, a barrier layer on the outer side than the moisture absorbing adhesive layer, and a polyolefin on the outer side of the barrier layer. The layer is formed in a manner. Further, a layer having other functions may be provided between the layers, for example, a layer having a fragrance retention property, a drug resistance, a light shielding property, a UV barrier property, or the like may be provided.

According to the present invention, since the moisture absorption adhesive layer is provided on the side of the outermost layer contacting the substrate layer, it is boiled. In the sterilizing heat treatment, moisture absorbed from the outside is absorbed by the moisture absorbing adhesive layer, and it is prevented from reaching the substrate layer.

Again, the barrier layer is boiling. In the sterilization heat treatment, after the moisture absorption, the water is released by the passage of time to restore the barrier property. Therefore, by setting the barrier layer It is more outward than the moisture absorbing adhesive layer, and the barrier property of the barrier layer is restored quickly.

According to the above, a multilayer sheet excellent in oxygen barrier properties can be provided.

The multilayer sheet of the present invention is characterized in that it comprises a base material layer and an outermost layer laminated on one side of the base material layer; the base material layer and the outermost layer each comprise a barrier At least two layers of the layer are formed.

The barrier layer is preferably used as the intermediate layer of the base material layer and the outermost layer, and in the case where the multilayer sheet is a container, it is preferably provided outside the center of the base material layer. In this way, the breakage of the barrier layer can be prevented when the container is subjected to the processing of the dent (cut).

According to the invention, since the barrier layer is provided on each of the base material layer and the outermost layer, high oxygen barrier properties can be exhibited.

In the multilayer sheet of the present invention, it is preferred to provide a moisture absorbing adhesive layer on the side of the outermost layer contacting the substrate layer.

According to the present invention, since the moisture absorption adhesive layer is provided on the side of the outermost layer contacting the substrate layer, it is boiled. In the sterilizing heat treatment, the moisture absorbing adhesive layer absorbs moisture intruding from the outside, and the barrier layer reaching the substrate layer can be prevented. For this reason, the decrease in the oxygen barrier property by the moisture absorption of the barrier layer can be prevented.

Therefore, the oxygen barrier property of the multilayer sheet can be further improved.

In the multilayer sheet of the present invention, it is preferred to provide a moisture absorbing adhesive layer between the polyolefin layer and the barrier layer.

In the present invention, the barrier layer is formed by being sandwiched by a moisture absorbing adhesive layer. If it is constructed in this way, it will be absorbed by the moisture absorption adhesive layer. It absorbs moisture intruding from the outside and prevents moisture from reaching the barrier layer. That is, the oxygen barrier property of the barrier layer can be further improved.

In the multilayer sheet of the present invention, the aforementioned barrier layer is made of methylene diamine (MXD) nylon or ethylene. A vinyl alcohol copolymer (EVOH) is preferably formed.

According to the present invention, since MXD nylon or EVOH is used as the barrier layer, a multilayer sheet excellent in oxygen barrier properties can be provided.

In the multilayer sheet of the present invention, it is preferred that a release layer is laminated on the other side of the base material layer.

The adhesive strength of the peeling layer and the base material layer is set to be smaller than the heat-sealing strength of the container and the lid member, and the container is formed by molding the multilayer sheet. In this way, when the lid member is unsealed, interlayer peeling can be performed between the peeling layer and the substrate layer. Therefore, the peeling surface can be made beautiful while the easy-opening property is excellent.

Further, since the heat-sealed portion of the container and the lid member can be firmly adhered to, the sealing property is also excellent.

In the multilayer sheet of the present invention, it is preferred to add talc to the base material layer.

The talc system functions to block the intrusion of oxygen molecules or hydrogen molecules into crops. Therefore, by adding talc to the base material layer, oxygen barrier properties can be enhanced while preventing moisture from intruding into the substrate layer.

Moreover, the rigidity of the multilayer sheet can be improved, and a container which is inferior to the metal can can be formed.

In the multilayer sheet of the present invention, the outermost layer is preferably a film for lamination.

Since the outermost layer can be separately produced as a film for lamination, the manufacturing process can be omitted.

The container of the present invention is characterized in that it has a flange portion for use with a lid member; and the multilayer sheet of the present invention is formed.

According to the present invention, since the above-mentioned multilayer sheet is used, it is possible to provide a container which exhibits the same effect.

A package according to the present invention includes the container of the present invention and a cover member that seals an opening of the container; and the cover member is attached to a flange portion of the container.

According to the present invention, since the multilayer sheet and the container are used, it is possible to provide a package which exhibits the same effect.

Hereinafter, embodiments of the present invention will be described based on the drawings.

First, a first embodiment of the present invention will be described with reference to Figs. 1, 2, and 3.

[First embodiment]

(I) Composition of multilayer sheet 1A:

Fig. 1 is a cross-sectional view showing a multilayer sheet 1A according to a first embodiment of the present invention.

The multilayer sheet 1A includes an outermost layer 11 having a polyolefin layer 111, a barrier layer 112, and a moisture absorbing adhesive layer 113, and a base material layer 12 composed of a first polyolefin layer 121 and a barrier layer 122. And the second polyolefin layer 123; and the release layer 13.

(I-1) The composition of the outermost layer 11:

The outermost layer 11 is a layer formed by using a film for lamination, and has a three-layer structure including a polyolefin layer 111, a barrier layer 112, and a moisture absorbing adhesive layer 113.

The resin which can be used for the polyolefin layer 111 may, for example, be polypropylene or polyethylene.

The barrier layer 112 is a gas barrier layer, as a raw material, for example, ethylene: Vinyl alcohol copolymer (EVOH), m-diamine (MXD) nylon, and the like. The case where EVOH is used as the barrier layer 112 is preferably formed to have a thickness of 4% or more and 20% or less with respect to the total thickness of the multilayer sheet 1A. More preferably, the total thickness of the multilayer sheet 1A is 8% or more and 15% or less. In this case, if the thickness of the barrier layer 112 is less than 4% of the total thickness, the barrier property is insufficient and it is impossible to store for a long period of time. Further, if the thickness of the barrier layer 112 is greater than 20% with respect to the total thickness, the container becomes poor in elongation during molding, which is not preferable.

Further, in the case where MXD nylon is used as the barrier layer 112, it is preferable to form the thickness of the layer of the multilayer sheet 1A to 4% or more and 10% or less. More preferably, the thickness of the multilayer sheet 1A is 5% or more and 9% or less. In this case, if the thickness of the barrier layer 112 is less than 4% of the total thickness, the barrier property is insufficient and it is impossible to store for a long period of time. Further, if the thickness of the barrier layer 112 is greater than 10% with respect to the total thickness, the container becomes poor in elongation during molding, which is not preferable.

In this embodiment, MXD nylon is used for the barrier layer 112 of the outermost layer 11.

The moisture absorbing adhesive layer 113 forms a surface in contact with the substrate layer 12, In addition to the absorbing water, the layer functions as an adhesive. For example, "water vapor barrier film ADMERR" manufactured by Mitsui Chemicals, Inc. can be used. The moisture absorbing adhesive layer 113 is preferably 5 μm or more and 300 μm or less, and more preferably 10 μm or more and 120 μm or less.

The outermost layer 11 of such a three-layer structure is subjected to lamination processing. Specifically, a known method such as dry lamination, heat lamination, or extrusion lamination can be used.

(I-2) Composition of the substrate layer 12:

The base material layer 12 has a three-layer structure including the first polyolefin layer 121, the barrier layer 122, and the second polyolefin layer 123.

Examples of the resin constituting the first polyolefin layer 121 and the second polyolefin layer 123 include HDPE (high density polyethylene), L-LDPE (low density polyethylene), and LDPE (low density polyethylene). ), HPP (single polypropylene), BPP (block polypropylene), RPP (random polypropylene), PET (polyethylene terephthalate), PBT (polybutylene terephthalate), Maleic acid denatured PP, styrene-isoprene copolymer, denatured polyester thermoplastic elastomer, EVA (ethylene-vinyl acetate copolymer), ethylene-propylene copolymer, and the like, and mixtures thereof . The resin used for the first polyolefin layer 121 and the second polyolefin layer 123 may be a resin of the same kind or a resin of a different type.

Further, the resin used in the first polyolefin layer 121 or the second polyolefin layer 123 may be added with talc. The talc is a raw material of a masterbatch containing aqueous magnesium silicate. Specifically, "S-U3" manufactured by Shinwa Plastic Co., Ltd., "MP465-2" manufactured by CALP Industrial Co., Ltd., or the like can be used.

The barrier layer 122 is similar to the barrier layer 112 described above and has gas barrier properties. Examples of the layer include, for example, EVOH, MXD nylon, and the like, and the thickness of the barrier layer 122 is also the same as that of the barrier layer 112. Further, in the present embodiment, EVOH is used as the barrier layer 122 of the base material layer 12.

When the materials of the barrier layer 122, the first polyolefin layer 121, and the second polyolefin layer 123 are made of the same system resin, the barrier layer 122 and the first polyolefin layer 121, and the barrier layer 122 and the second polyolefin layer are used. 123 is excellent in strength, so it is ideal.

(I-3) Composition of the peeling layer 13:

The release layer 13 is formed by laminating the base material layer 12 to be peelable. Alternatively, the peeling layer 13 itself may be a cohesive breaker. In any case, after the other film is firmly adhered to the peeling layer 13, the peeling test is performed, and the peel strength is preferably 25 N/15 mm or less (JIS K 6854). In the case of such a low peeling strength, the multilayer sheet 1A for molding a container for a package to be described later can be suitably used.

Examples of the resin constituting the release layer 13 include HDPE, L-LDPE, LDPE, HPP, BPP, RPP, PET, PBT, ethylene maleic anhydride methacrylate copolymer, and A mixture of the copolymer and a polyolefin, and the like. Further, in the case where the peeling mechanism constitutes agglomeration failure of the resin by the peeling layer, it is preferable to use a soft resin or an elastomer having an elastic modulus of 200 MPa or less, particularly 150 MPa or less. The soft resin may, for example, be an ethylene-polar ethylene compound-based copolymer. In addition, examples of the elastomer include an olefin-based elastomer, a styrene-based elastomer, and the like. In this embodiment, HDPE is used.

In terms of the thickness of the peeling layer 13, a ring-shaped cut which will be described later is provided on the flange For the case of the outer surface of the part, it is suitable for 30 to 120 μm. If there is no cut, it is suitable for 5 to 40 μm.

In the case where the cut is provided, if the thickness of the peeling layer 13 is less than 30 μm, it is difficult to leave the depth of the cut in the peeling layer 13. If the thickness of the peeling layer 13 exceeds 120 μm, the thickness after the formation of the container, in particular, the thickness of the flange portion becomes too thick, and it is difficult to apply it as a thin container. Further, in the case where the cut is not provided, if the thickness of the peeling layer 13 is less than 5 μm, the internal pressure resistance is deteriorated after the container is sealed with the lid member. If the thickness of the peeling layer 13 exceeds 30 μm, it is detrimental to one of the advantages of the case where the cut is not provided (in the case of achieving thin meat of the container and having easy-opening property).

When peeling off the base material layer 12 and the peeling layer 13 as a peeling mechanism, the adhesive strength of the base material layer 12 and the peeling layer 13 can be controlled by suitably selecting the kind of each constituent resin. strength). For example, in the case where the sealant of the cover material described later is polypropylene, the raw material of the release layer 13 is atactic polypropylene, and the raw material of the base material layer 12 is a mixture of polypropylene and polyethylene (for polyethylene) The ratio is more). Further, when the sealant of the cover material is a linear low-density polyethylene (LLDPE)-like polyethylene, the raw material of the release layer 13 is made of polyethylene, and the raw material of the base material layer 12 is made of polypropylene. It is preferred to mix with polyethylene (the ratio of polypropylene is large). In order to cause agglomeration damage to the inside of the peeling layer 13 and the base material layer 12, it is preferable to use a composition which is suitable for mixing the above-mentioned elastomer as a raw material of a layer to be agglomerated.

(I-4) Manufacturing method of multilayer sheet 1A:

First, the outermost film form produced by the co-extrusion molding method described above The layer 11 is slit to a specific width and is first wound into a roll shape. Next, the multilayer sheet 1A is produced (extrusion lamination) by extruding the base material layer 12 and the peeling layer 13 which have been laminated in a specific order from the extruder, and laminating them in a molten state from the reel The film-shaped outermost layer 11 is taken out. Further, in addition to this, it may be carried out by co-extrusion, heat lamination, dry lamination, or the like, and may be carried out in a combination of stages or the like.

Next, while cooling and solidifying by means of a contact roll or a pneumatic blade, the sheet thickness is adjusted by increasing or decreasing the take-up speed. Thereafter, while taking the sheet which has been solidified on the reel, slitting (width reduction) is carried out, and after passing through a continuous thickness gauge and a foreign matter detector, the sheet is wound into a roll by a large winder. Cylindrical. Finally, a roll of a multilayer sheet having a predetermined length is bundled with an aluminum film (moisture proof) and kraft paper (to prevent foreign matter from adhering) to form a final product.

(II) Composition of package 2:

The package 2 will be described with reference to Figs. 2 and 3 . Fig. 2 is a perspective view of a package body according to a first embodiment of the present invention, and Fig. 3 is a cross-sectional view of a main part of the package body according to the first embodiment of the present invention.

The package 2 shown in Fig. 2 is configured to include a container 3 which is formed by thermoforming using the multilayer sheet 1A, and a cover member 4 which covers the opening of the container 3.

(II-1) Composition of the container 3:

The container 3 includes a concave portion 31 for receiving the packaged object, and a flange portion 32 formed on the peripheral edge of the opening of the concave portion 31. The recessed portion 31 has a cylindrical shape with a bottom; the flange portion 32 is a flat convex portion that extends outward from the opening of the recessed portion 31 in the horizontal direction. edge. In the flange portion 32, an annular notch portion 33 is provided in the vicinity of the opening of the main body of the container 3. This incision portion 33 penetrates the peeling layer 13 to reach the base material layer 12.

(II-2) Composition of the cover material 4:

The cover member 4 has an outer diameter larger than the outer diameter of the flange portion 32 of the container 3. The cover member 4 is composed of a multilayer structure in which the outer surface of the flange portion 32 (the surface of the peeling layer 13) and the outer peripheral portion of the annular notch portion 33 are firmly heat-sealed, and the multilayer structure is formed. A transparent vapor-deposited PET film 41 and a biaxially stretched nylon film (ONy film) 42 having oxygen barrier properties as a surface substrate, and an L-LDPE film 43 as a sealant. Further, the thermal strength of the heat seal is preferably greater than the strength of the adhesion between the release layer 13 and the substrate layer 12.

If the end portion of the lid member 4 attached to the container 3 is pulled up in this manner, since the peeling layer 13 of the flange portion 32 and the lid member 4 are firmly adhered to each other, the peeling layer having a small strength is attached. The interface between the substrate 13 and the substrate layer 12 starts to peel off, and when the incision portion 33 is reached, the lid member 4 is separated from the container 3. Further, it may be configured such that cohesive failure occurs in the peeling layer 13.

Here, in the case of constituting the package 2, it is preferable that the cover member 4 has oxygen barrier properties similar to those of the multilayer sheet 1A. For example, in addition to the surface substrate having an oxygen barrier cerium oxide film such as a transparent vapor-deposited PET film, an EVOH layer or an aluminum foil may be used as an intermediate layer.

(II-3) Manufacturing method of package 2:

A method of manufacturing the package 2 of the present embodiment will be described.

First, in terms of the forming method of the container 3, it can be considered that the plug is assisted. In the shape, the multilayer sheet 1A is preliminarily stretched in a chamber formed into a shape outside the container by a plug, and then subjected to pressure forming or vacuum forming.

Specifically, the multilayer sheet 1A produced by the above method is fed between a concave mold, a flange fixture, and a plug which are not shown, in this state, by fixing the flange and the plug The column is moved to the mold side to manufacture the container 3, which has formed the recess 31 and the flange portion 32 for accommodating the contents P.

Thereafter, a notch knife (not shown) is caught by the flange portion 32 of the container 3, and the notch portion 33 is formed into a ring shape.

Next, the lid member 4 is placed on the flange portion 32 of the container 3 in which the contents P are stored, and the outer peripheral side of the incision portion 33 is heat-sealed. An annular seal portion (not shown) is formed between the flange portion 32 and the lid member 4. The heat seal is performed by sandwiching the flange portion 32 from the lid member 4 by a sealing rod (not shown).

(III) Effect of the first embodiment

Therefore, according to this embodiment, the following effects can be exhibited.

(1) A barrier layer 112 made of EVOH is provided on the outermost layer 11 of the multilayer sheet 1A, and a barrier layer 122 made of MXD nylon is provided on the base layer 12.

Since the barrier layer of the barrier layer 112 and the barrier layer 122 is provided in the multilayer sheet 1A, the oxygen barrier property is excellent. Therefore, the container 3 and the package 2 excellent in oxygen barrier properties can be provided. That is, contents such as foods can be preserved for a long period of time.

(2) Further, in the present embodiment, the moisture absorbing adhesive layer 113 is provided on the side of the base material layer 12 of the outermost layer 11, and further, the moisture absorbing adhesive is used. The barrier layer 112 is provided on the outer side of the layer 113, so that the oxygen barrier property can be further improved.

Further, by providing the moisture absorbing adhesive layer 113, when the container composed of the multilayer sheet is sterilized, the moisture reaching the barrier layer can be absorbed and blocked, and the sterilizing impact can be suppressed to become A container with excellent water resistance.

(3) In the present embodiment, since the first polyolefin layer 121 and the second polyolefin layer 123 of the base material layer 12 contain talc, it is possible to provide a container excellent in rigidity.

(4) Further, in the present embodiment, the peeling layer 13 is provided on the multilayer sheet 1A, and the adhesion strength between the peeling layer 13 and the base material layer 12 is made smaller than the adhesion strength between the peeling layer 13 and the lid member 4, so When the package 2 is unsealed, interlayer peeling is performed between the peeling layer 13 and the base material layer 12.

Therefore, since the peeling layer 13 and the lid member 4 are strongly heat-sealed, the sealing property is excellent.

(5) Further, since the annular cut portion 33 is formed in the flange portion 32 of the container 3, when the cover member 4 thermally sealed to the container 3 is opened, the peeling of the peeling layer 13 reaches the cut mark. In the portion 33, the lid member 4 and the container 3 can be easily separated. That is, the easy opening property is excellent.

[Second embodiment]

Next, a second embodiment of the present invention will be described with reference to Fig. 4 .

In the present embodiment, the layer configuration of the multilayer sheet is the same as that of the first embodiment described above, and thus the description thereof is omitted.

(I) Composition of multilayer sheet 1B:

Fig. 4 is a cross-sectional view showing a multilayer sheet 1B according to a second embodiment of the present invention.

The multilayer sheet 1B includes an outermost layer 11 having a polyolefin layer 111, a barrier layer 112, and a moisture absorbing adhesive layer 113; a base material layer 12; and a release layer 13.

Since the outermost layer 11 and the peeling layer 13 have the same configuration as that of the first embodiment described above, the description thereof is omitted.

The base material layer 12 is formed of a single layer and is formed of a resin such as polyolefin. The same resin as that of the first polyolefin layer 121 and the second polyolefin layer 123 of the first embodiment described above can be used.

(II) Effect of the second embodiment:

Therefore, according to this embodiment, the same effects as those of the first embodiment described above can be exhibited.

[Third embodiment]

Next, a third embodiment of the present invention will be described with reference to Fig. 5 .

In the present embodiment, the layer configuration and the manufacturing method of the multilayer sheet are the same as those of the first embodiment, and thus the description thereof is omitted.

(I) Composition of multilayer sheet 1C:

Fig. 5 is a cross-sectional view showing a multilayer sheet 1C according to a third embodiment of the present invention.

The multilayer sheet 1C includes an outermost layer 14 having a polyolefin layer 141, a first moisture absorbing adhesive layer 142, a barrier layer 143, and a second moisture absorbing adhesive layer 144; a base material layer 12; and a peeling layer 13 .

Since the base material layer 12 and the peeling layer 13 have the same configuration as that of the above-described first embodiment, the description thereof is omitted. Further, the base material layer 12 can be suitably designed, for example, in the same configuration as the second embodiment described above.

The outermost layer 14 is the same as the outermost layer 11 of the first embodiment except that the first moisture absorbing adhesive layer 142 is provided between the barrier layer 143 and the polyolefin layer 141.

The first moisture absorbing adhesive layer 142 and the second moisture absorbing adhesive layer 144 can be used in the same manner as in the moisture absorbing adhesive layer 113 of the first embodiment.

(II) Manufacturing method of multilayer sheet 1C:

In the present embodiment, the outermost layer 14 is not used as a film for lamination, and is produced by extrusion molding using an extruder similarly to the base layer 12 and the peeling layer 13. In addition to this, it may be carried out by hot lamination, dry lamination, or the like, and may be carried out in a combination of stages or the like.

The treatment after the extrusion is carried out in the same manner as in the first embodiment described above, and becomes a final product.

(III) Effect of the third embodiment:

Therefore, according to the present embodiment, the same effect as the first embodiment described above can be exerted, and the moisture absorbing adhesive layer (the first moisture absorbing adhesive layer 142 and the second moisture) are provided on both surfaces of the barrier layer 143. Since the adhesive layer 144 is absorbed, the intrusion of moisture from the outside to the barrier layer 143 can be surely prevented, and the oxygen barrier property by the barrier layer 143 can be further improved.

[Modification]

In addition, the aspect described above shows the same state of the present invention, The invention is not limited to the foregoing embodiments, and variations or improvements within the scope of the objects and effects of the invention are also included in the scope of the invention. Further, the specific structure, shape, and the like in the practice of the present invention may be other structures, shapes, and the like within the scope of the object and effect of the invention.

For example, in the first embodiment, the moisture absorbing adhesive layer 113 is provided on the base material layer 12 side of the outermost layer 11, but the water absorbing adhesive layer 113 may not be provided. In this case, it is preferred to provide a polyolefin layer on the side of the base material layer 12 of the outermost layer 11.

Further, in the first embodiment, MXD nylon is used for the barrier layer 112 of the outermost layer 11, EVOH is used for the barrier layer 122 of the base material layer 12, but EVOH is used for the barrier layer 112 of the outermost layer 11, The barrier layer 122 of the substrate layer 12 may also be MXD nylon. Further, if EVOH is used for the barrier layers of both sides, MXD nylon may be used for the barrier layers of both sides.

In the first embodiment, the outermost layer 11 has a three-layer structure, but may be composed of two layers of a barrier layer and a polyolefin layer.

Further, in the above embodiment, the resin forming the polyolefin layer contains talc, but it may be a structure which does not contain talc, and the polyolefin layer constitutes the base material layer 12.

Further, a moisture absorbing adhesive layer may be provided on the front and back surfaces of the barrier layer 122. In this way, further improvement in oxygen barrier properties can be achieved.

Further, in the above embodiment, an adhesive layer may be provided between the respective layers. In this way, the adhesion strength between the layers can be further improved.

Further, in the foregoing embodiment, although the container 3 is provided with one cut portion 33. However, the second notch portion in the annular shape may be provided at a position separated from the incision portion 33 on the outer peripheral side of the incision portion 33. In this case, the easy-sealing property of the package 2 is further improved by heat-sealing the incision portion 33 and the second incision portion.

Further, the multilayer sheet of the above-described embodiment may be formed such that the outermost layer becomes the inner surface of the container. According to this, the outermost polyolefin layer and the lid member are heat-sealed, and the polyolefin layer is subjected to cohesive peeling at the time of opening.

[Examples]

Hereinafter, the present invention will be described in more detail by way of examples and comparative examples, but the present invention is not limited by the description of the examples and the like.

[Examples 1 to 15 and Comparative Examples 1 to 5]

The multilayer sheets of Examples 1 to 15 and Comparative Examples 1 to 5 were produced in the layer constitution and materials shown in Table 1 below, and a container and a package composed of the multilayer sheets were produced.

(1) Manufacture of multilayer sheets

In the examples 1 to 13 and the comparative examples 1 to 5, a multilayer sheet having the layer structure shown below was produced.

(peeling layer) / (base material layer) (polyolefin layer A2 / polyolefin layer A 1 / adhesive layer / barrier layer B / adhesive layer / polyolefin layer C 1 / polyolefin layer C2) / (outermost layer) (poly Olefin layer D / barrier layer E / polyolefin layer F)

In the case of Examples 14 and 15, a multilayer sheet composed of a release layer and a base material layer in the above layer was produced.

First, each layer was formed by melt-extracting each layer using a dedicated extruder (manufactured by Mitsubishi Heavy Industries Co., Ltd.) using the materials shown below. Extraterrestrial The layer system was used by Taisei Lamick Co., Ltd. to perform dry lamination processing using the following materials.

(Substrate layer: polyolefin layer A, C)

Polypropylene ("E105GM", "E100GV" and "E154G" manufactured by PRIMEPOLYMER Co., Ltd.), and polyethylene ("HE30" manufactured by Nippon Polyethylene Co., Ltd., "ENGAGE 8200" manufactured by DOW Co., Ltd.) are mixed to further contain WHITE M/B. ("W190078" made by Tokyo INK Corporation). The addition ratio is in the mass ratio of PP:PE:WHITE M/B=80:16:4.

In the case of containing talc, "S-U3" (trade name, manufactured by Shinwa Plastics Co., Ltd.) or "MP465-2" (trade name, manufactured by CALP Industrial Co., Ltd.) or the like is mixed. The addition ratio in this case is in the mass ratio of PP: PE: WHITE M/B: talc = 56: 10: 4:30.

(barrier layer B, E)

Any of the resins shown below can be used.

. EVOH ("SP-521B" manufactured by KURARAY Co., Ltd.), thickness: 12% of total thickness.

. MXD nylon ("S7007" manufactured by Mitsubishi Gas Chemical Co., Ltd.), thickness: 6% of total thickness.

(outermost layer: polyolefin layer D, F)

The same resin as used in the above polyolefin layers A, B can be used.

Further, in the case where the polyolefin layer D is a moisture absorbing adhesive layer, a water vapor barrier film ADMERR (manufactured by Mitsui Chemicals, Inc.) is used.

(adhesive layer)

"MODIC P604V" (trade name, Mitsubishi) is used as the adhesive layer Chemical Co., Ltd.).

Further, in the examples 14 and 15, a water vapor barrier film ADMERR (manufactured by Mitsui Chemicals, Inc.) using a moisture absorbing adhesive was used as the adhesive layer.

Next, lamination of the multilayer sheets is carried out.

After laminating the layers in the above-described order, the layers were widened by a T-die (manufactured by Mitsubishi Heavy Industries, Ltd.). Then, on the lower surface of the molten sheet extruded from the T-die, the film for lamination constituting the outermost layer is sandwiched in parallel, and continuous heat lamination is performed to form the multilayer sheet.

After the forming, the multilayer sheet is cooled and solidified by means of a contact roll or a pneumatic blade, and the thickness of the sheet is adjusted by increasing or decreasing the take-up speed.

The thickness of each layer is as follows.

(2) Manufacture of containers

After heating the aforementioned multilayer sheet, it is introduced into a continuous vacuum. The air-pressure forming machine (the CM molding machine manufactured by Sumitomo Heavy Industries Co., Ltd., manufactured by iLLig Co., Ltd., and the Institute of Research Institute) was subjected to plug-assisted vacuum air pressure, and was thermoformed into a container shape. Next, after forming a ring-shaped notch (dent) in the flange portion of the container, the container was punched.

(3) Manufacture of package

In the case of the lid member, the laminate was heat sealed to the flange portion of the container to form a package.

The composition of the cover material: polyethylene terephthalate (PET) 12 μm / biaxially stretched nylon film (ONy) 15 μm / aluminum (A1) 7 μm / "OMAC CPP sealant" manufactured by Mitsui Chemicals Co., Ltd. 70 μm

<Evaluation of oxygen barrier properties>

The oxygen barrier properties of the container were evaluated according to the following procedure.

(1) The reducing solution (pyrogallol. lye) is prepared in advance in an environment where oxygen is removed.

(2) The reducing liquid of the above (1) is filled in an environment where oxygen is removed. The containers of Examples 1 to 15 and Comparative Examples 1 to 5 were sealed, and the entire container was sterilized.

Here, the absorbance of the reducing liquid was measured as a blank (reference).

(3) After the sterilization treatment, it is stored in a constant temperature and humidity chamber under the promotion conditions of 30 ° C × 75% RH, and after a predetermined number of days, the absorbance of the reducing liquid in the container is measured, and the cumulative oxygen permeation amount is measured.

The content of the evaluation is as follows.

A: Very good B: Excellent C: Good D: Poor (not available)

(result)

The evaluation results of Examples 1 to 15 and Comparative Examples 1 to 5 are shown in Table 2 below.

Examples 1 to 15 were excellent in oxygen barrier properties. Among them, Example 7 is particularly excellent in oxygen barrier properties.

On the other hand, Comparative Examples 1 to 5 were insufficient in oxygen barrier properties and were not practical.

1A, 1B, 1C‧‧‧ multilayer sheet

2‧‧‧Package

3‧‧‧ Container

4‧‧‧Cleaning

11, the outermost layer of 14‧‧

12‧‧‧Substrate layer

13‧‧‧ peeling layer

31‧‧‧ recess

32‧‧‧Flange

33‧‧‧cutting department

41‧‧‧Transparent vapor-deposited PET film

42‧‧‧Two-axis extended nylon film (ONy film)

43‧‧‧L-LDPE film

111, 141‧‧ ‧ polyolefin layer

112, 122, 143‧‧ ‧ barrier

113‧‧‧Water absorption adhesive layer

121‧‧‧1st polyolefin layer

123‧‧‧2nd polyolefin layer

142‧‧‧1st moisture absorption adhesive layer

144‧‧‧2nd moisture absorption adhesive layer

P‧‧‧Contents

Fig. 1 is a cross-sectional view showing a multilayer sheet according to a first embodiment of the present invention.

Fig. 2 is a perspective view showing a package body according to a first embodiment of the present invention.

Fig. 3 is a cross-sectional view showing the main part of a package according to a first embodiment of the present invention.

Fig. 4 is a cross-sectional view showing a multilayer sheet according to a second embodiment of the present invention.

Fig. 5 is a cross-sectional view showing a multilayer sheet relating to a third embodiment of the present invention.

1A‧‧‧Multilayer sheet

11‧‧‧ outermost layer

12‧‧‧Substrate layer

13‧‧‧ peeling layer

111‧‧‧ polyolefin layer

112, 122‧‧‧ barrier

113‧‧‧Water absorption adhesive layer

121‧‧‧1st polyolefin layer

123‧‧‧2nd polyolefin layer

Claims (13)

A multilayer sheet comprising a base material layer and an outermost layer laminated on one side of the base material layer; wherein the outermost layer is formed of at least three layers, and includes: moisture The absorbing adhesive layer is provided on the side in contact with the substrate layer to absorb moisture and function as an adhesive; the barrier layer is provided on the opposite side of the moisture absorbing adhesive layer from the substrate layer, and the meta-diamine (MXD) formed of nylon or ethylene ‧ vinyl alcohol copolymer (EVOH); and a polyolefin layer disposed on the opposite side of the barrier layer from the moisture absorbing adhesive layer. A multilayer sheet comprising a base material layer and an outermost layer laminated on one side of the base material layer; wherein the base material layer and the outermost layer are respectively included At least two layers of barrier layers formed by decylamine (MXD) nylon or ethylene ‧ vinyl alcohol copolymer (EVOH) are formed. The multilayer sheet according to claim 2, wherein a moisture absorbing adhesive layer which absorbs moisture and functions as an adhesive is provided on a side of the outermost layer which is in contact with the base material layer. The multilayer sheet according to claim 1, wherein a moisture absorbing adhesive layer which absorbs moisture and functions as an adhesive is provided between the polyolefin layer and the barrier layer. The multilayer sheet according to any one of claims 1 to 4, wherein talc is added to the aforementioned substrate layer. The multilayer sheet according to any one of claims 1 to 4, wherein the substrate layer comprises a first polyolefin layer, a barrier layer, and The at least three layers of the second polyolefin layer are formed; the outermost layer is formed of at least three layers, and includes a moisture absorbing adhesive layer disposed on a side in contact with the substrate layer; and a barrier layer disposed on the moisture layer a side opposite to the base material layer of the adhesive layer; and a polyolefin layer provided on the opposite side of the barrier layer from the moisture absorption adhesive layer; the first polyolefin layer of the base material layer and the first 2 talc is added to the polyolefin layer. The multilayer sheet of claim 6, wherein the barrier layer contained in the substrate layer is formed of ethylene vinyl alcohol copolymer (EVOH); and the barrier layer contained in the outermost layer is composed of ethylene ‧ vinyl alcohol copolymer (EVOH) Formed. The multilayer sheet of claim 6, wherein the barrier layer contained in the substrate layer is formed of ethylene vinyl alcohol copolymer (EVOH); and the barrier layer contained in the outermost layer is made of methylene diamine (MXD) nylon. form. The multilayer sheet of claim 6, wherein the barrier layer contained in the substrate layer is formed of metaxane diamine (MXD) nylon; and the barrier layer contained in the outermost layer is composed of ethylene ‧ vinyl alcohol copolymer (EVOH) form. The multilayer sheet of any one of claims 1 to 4, wherein A release layer is laminated on the other surface side of the base material layer. The multilayer sheet according to any one of claims 1 to 4, wherein the outermost layer is a film for lamination. A container characterized in that it has a flange portion for use with a cover member; and the multilayer sheet of any one of claims 1 to 11 is formed. A package comprising: a container according to claim 12; and a lid member that seals an opening of the container; and the cover member is attached to a flange portion of the container.