JP5962796B2 - Delamination container - Google Patents

Description

  The present invention relates to a laminated peeling container in which an inner layer peels from an outer layer and shrinks with a decrease in contents.

  2. Description of the Related Art Conventionally, there has been known a laminated peeling container that suppresses air from entering the container by peeling and shrinking the inner layer from the outer layer as the contents are reduced (for example, Patent Document 1). Such a delamination container includes an inner bag constituted by an inner layer and an outer shell constituted by an outer layer.

Japanese Patent No. 3563172

  By the way, the inner layer may be provided with an EVOH layer made of EVOH in order to improve the peelability from the outer layer and improve the gas barrier property. However, since general EVOH has high rigidity and is inferior in bending resistance, the EVOH layer may be bent and a pinhole may be formed in the EVOH layer when the inner bag shrinks. When pinholes are formed in the EVOH layer, the gas barrier properties are impaired.

  This invention is made | formed in view of such a situation, and provides the lamination peeling container which can prevent that a pinhole is formed in an EVOH layer when an inner bag shrink | contracts.

  According to the present invention, an outer layer and an inner layer are provided, and the inner layer is an exfoliated and peeled container that shrinks as the contents decrease from the outer layer, and the inner layer includes an EVOH layer made of EVOH, EVOH provides a delamination container having an ethylene content of 32 mol% or less and a flexural modulus of 2350 MPa or less.

The present inventor has intensively studied to suppress the formation of pinholes in the EVOH layer and reduce the gas barrier properties. As a result, the ethylene content is 32 mol% or less and the flexural modulus is 2350 MPa or less. When the EVOH layer was formed with EVOH, the bending resistance of the EVOH layer became extremely high, and it was found that no pinhole was formed when the inner bag contracted, and the present invention was completed.
Moreover, it is preferable that the EVOH does not generate a pinhole according to a predetermined bending resistance test using a gelbo flex tester. In this case, the pinhole is not easily formed when the inner bag shrinks.

It is a perspective view which shows the structure of the lamination peeling container 1 of one Embodiment of this invention, (a) is a general view, (b) shows a bottom part. 1 shows a delamination container 1 of FIG. 1, in which (a) is a front view, (b) is a rear view, (c) is a plan view, and (d) is a bottom view. It is AA sectional drawing in FIG.2 (d). 1 to FIG. 2 show a state before the bottom seal protrusion 27 is bent, and FIG. 3 shows a state after the bottom seal protrusion 27 is bent. It is an enlarged view of the area | region containing the opening part 9 of FIG. The state which peeling of the inner layer 13 advanced from the state of FIG. FIG. 4 is an enlarged view of a region including a bottom surface 29 in FIG. 3, (a) shows a state before the bottom seal protrusion 27 is bent, and (b) shows a state after the bottom seal protrusion 27 is bent. Show. 3 is a cross-sectional view showing a layer configuration of an inner layer 13. FIG. It is a perspective view which shows the various structures of the valve member 5. FIG. The manufacturing process of the lamination peeling container 1 of FIG. 1 is shown. The process following FIG. 9 of the lamination peeling container 1 of FIG. 1 is shown. Another example of the inner layer preliminary peeling / outside air introduction hole forming step is shown. The usage method of the lamination peeling container 1 of FIG. 1 is shown.

  Hereinafter, embodiments of the present invention will be described. Various characteristic items shown in the following embodiments can be combined with each other. The invention is established independently for each feature.

  As shown in FIGS. 1 to 2, the delamination container 1 according to an embodiment of the present invention includes a container body 3 and a valve member 5. The container body 3 includes a storage portion 7 that stores the contents, and a mouth portion 9 that discharges the contents from the storage portion 7.

  As shown in FIG. 3, the container body 3 includes an outer layer 11 and an inner layer 13 in the accommodating portion 7 and the mouth portion 9, an outer shell 12 is constituted by the outer layer 11, and an inner bag 14 is constituted by the inner layer 13. The As the content decreases, the inner layer 13 peels from the outer layer 11, whereby the inner bag 14 peels from the outer shell 12 and contracts.

  As shown in FIG. 4, the mouth portion 9 is provided with a male screw portion 9d. A cap or a pump having a female screw is attached to the male screw portion 9d. FIG. 4 shows a part of the cap 23 having the inner ring 25. The outer diameter of the inner ring 25 is substantially the same as the inner diameter of the mouth portion 9, and the outer surface of the inner ring 25 abuts against the abutting surface 9a of the mouth portion 9, thereby preventing leakage of the contents. In the present embodiment, the enlarged diameter portion 9b is provided at the tip of the mouth portion 9, and the inner diameter of the enlarged diameter portion 9b is larger than the inner diameter of the contact portion 9e. The outer surface is not in contact with the enlarged diameter portion 9b. In the case where there is no enlarged diameter portion 9b in the mouth portion 9, there is a problem that the inner ring 25 enters between the outer layer 11 and the inner layer 13 when the inner diameter of the mouth portion 9 is slightly reduced due to variations in manufacturing. In some cases, however, when the mouth portion 9 has the enlarged diameter portion 9b, such a problem does not occur even if the inside diameter of the mouth portion 9 varies slightly.

  Further, the mouth portion 9 includes an inner layer support portion 9c that suppresses the slippage of the inner layer 13 at a position closer to the housing portion 7 than the contact portion 9e. The inner layer support portion 9 c is formed by providing a constriction at the mouth portion 9. Even when the enlarged diameter portion 9 b is provided in the mouth portion 9, the inner layer 13 may be separated from the outer layer 11 due to friction between the inner ring 25 and the inner layer 13. In the present embodiment, even in such a case, the inner layer support portion 9c suppresses the displacement of the inner layer 13, so that the inner bag 14 can be prevented from falling into the outer shell 12.

  As shown in FIGS. 3 to 5, the accommodating portion 7 includes a trunk portion 19 having a substantially constant cross-sectional shape in the longitudinal direction of the accommodating portion, and a shoulder portion 17 that connects the trunk portion 19 and the mouth portion 9. Is provided. The shoulder portion 17 is provided with a bent portion 21. The bending portion 21 is a portion where the bending angle α shown in FIG. 3 is 140 degrees or less and the radius of curvature on the inner surface side of the container is 4 mm or less. When there is no bent portion 21, the separation between the inner layer 13 and the outer layer 11 spreads from the body portion 19 to the mouth portion 9, and the inner layer 13 and the outer layer 11 may be separated at the mouth portion 9. However, if the inner layer 13 and the outer layer 11 are peeled at the mouth portion 9, the inner bag 14 may fall into the outer shell 12, and therefore, the peeling of the inner layer 13 and the outer layer 11 at the mouth portion 9 is not desirable. In this embodiment, since the bent portion 21 is provided, when the separation between the inner layer 13 and the outer layer 11 spreads from the body portion 19 to the bent portion 21, the inner layer 13 is bent at the bent portion 21 as shown in FIG. Therefore, the force for peeling the inner layer 13 from the outer layer 11 is not transmitted to the upper part of the bent portion 21, and as a result, the peeling between the inner layer 13 and the outer layer 11 in the upper part of the bent portion 21 is suppressed. The 3 to 5, the bent portion 21 is provided in the shoulder portion 17, but the bent portion 21 may be provided at the boundary between the shoulder portion 17 and the trunk portion 19.

The lower limit of the bending angle α is not particularly defined, but is preferably 90 ° or more in consideration of ease of manufacture. The lower limit of the radius of curvature is not particularly specified, but is preferably 0.2 mm or more in consideration of ease of production. In order to prevent the inner layer 13 and the outer layer 11 from peeling off at the mouth 9, the bending angle α is preferably 120 degrees or less, and the curvature radius is preferably 2 mm or less. Specifically, the bending angle α is, for example, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140 degrees, and is within a range between any two of the numerical values exemplified here. It may be. Specifically, the curvature radius is, for example, 0.2, 0.4, 0.6, 0.8, 1, 1.2, 1.4, 1.6, 1.8, 2 mm, where It may be within a range between any two of the exemplified numerical values.

  As shown in FIG. 4, the bent portion 21 has a distance L2 from the container central axis C to the inner surface of the container at the bent portion 21 of 1.3. It is provided at a position that is double or more. The delamination container 1 of the present embodiment is formed by blow molding, and as L2 / L1 increases, the blow ratio at the bent portion 21 increases and the wall thickness decreases, so that L2 / L1 ≧ 1. 3, the thickness of the inner layer 13 at the bent portion 21 is sufficiently reduced, the inner layer 13 is more easily bent at the bent portion 21, and the inner layer 13 and the outer layer 11 are more reliably separated at the mouth portion 9. Is prevented. L2 / L1 is, for example, 1.3 to 3, and preferably 1.4 to 2. Specifically, L2 / L1 is, for example, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.5, 3, where It may be within a range between any two of the numerical values exemplified in.

  In one example, the thickness at the mouth portion 9 is 0.45 to 0.50 mm, the thickness at the bent portion 21 is 0.25 to 0.30 mm, and the thickness at the trunk portion 19 is 0. .15 to 0.20 mm. Thus, when the thickness of the bent portion 21 is sufficiently smaller than the thickness at the mouth portion 9, the bent portion 21 effectively exhibits its function.

  By the way, as shown in FIG. 4, in the accommodating portion 7, the valve member 5 that adjusts the flow of air between the intermediate space 21 between the outer shell 12 and the inner bag 14 and the outer space S of the container body 3. Is provided. The outer shell 12 is provided with an outside air introduction hole 15 that communicates the intermediate space 21 and the outer space S in the housing portion 7. The outside air introduction hole 15 is a through hole provided only in the outer shell 12 and does not reach the inner bag 14. The valve member 5 is inserted in the outside air introduction hole 15 and is slidable with respect to the outside air introduction hole 15. The valve member 5 is provided on the intermediate space 21 side of the shaft part 5a and has a larger sectional area than the shaft part 5a. The cover part 5c and the latching | locking part 5b which are provided in the external space S side of the axial part 5a and prevent the valve member 5 entering the intermediate space 21 are provided.

  The lid portion 5c is configured to substantially close the outside air introduction hole 15 when the outer shell 12 is compressed, and has a shape in which the cross-sectional area decreases as the shaft portion 5a is approached. Moreover, the latching | locking part 5b is comprised so that air can be introduce | transduced into the intermediate | middle space 21 when decompress | restoring after the outer shell 12 is compressed. When the outer shell 12 is compressed, the pressure in the intermediate space 21 becomes higher than the external pressure, and the air in the intermediate space 21 leaks out from the outside air introduction hole 15. The lid 5c moves toward the outside air introduction hole 15 due to the pressure difference and the air flow, and the lid 5c closes the outside air introduction hole 15. Since the cross-sectional area becomes smaller as the lid portion 5 c approaches the shaft portion 5 a, the lid portion 5 c easily fits into the outside air introduction hole 15 and closes the outside air introduction hole 15.

  When the outer shell 12 is further compressed in this state, the pressure in the intermediate space 21 is increased. As a result, the inner bag 14 is compressed and the contents in the inner bag 14 are discharged. Further, when the compressive force applied to the outer shell 12 is released, the outer shell 12 tries to recover by its own elasticity. At this time, the lid portion 5 c is separated from the outside air introduction hole 15, the outside air introduction hole 15 is released from being blocked, and outside air is introduced into the intermediate space 21. Further, the locking portion 5b is provided with a protrusion 5d at a portion that contacts the outer shell 12 so that the locking portion 5b does not block the outside air introduction hole 15, and the protrusion 5d contacts the outer shell 12. Thus, a gap is provided between the outer shell 12 and the locking portion 5b. Instead of providing the protrusion 5d, a groove may be provided in the locking portion 5b to prevent the locking portion 5b from closing the outside air introduction hole 15. A specific example of the configuration of the valve member 5 is shown in FIG.

  The valve member 5 can be mounted on the container body 3 by inserting the lid 5c into the intermediate space 21 while the lid 5c pushes the outside air introduction hole 15 wide. Therefore, it is preferable that the tip of the lid portion 5c has a tapered shape. Such a valve member 5 can be mounted simply by pushing the lid 5c into the intermediate space 21 from the outside of the container body 3, and thus is excellent in productivity.

  The accommodating part 7 is covered with a shrink film after the valve member 5 is attached. At this time, the valve member 5 is mounted in a valve member mounting recess 7 a provided in the housing portion 7 so that the valve member 5 does not interfere with the shrink film. An air flow groove 7b extending from the valve member mounting recess 7a in the direction of the mouth 9 is provided so that the valve member mounting recess 7a is not sealed with the shrink film.

  As shown in FIG. 1B, the bottom surface 29 of the accommodating portion 7 is provided with a central concave region 29 a and a peripheral region 29 b provided around the central concave region 29 a, and the central concave region 29 a has a bottom protruding from the bottom surface 29. A seal protrusion 27 is provided. As shown in FIGS. 6A to 6B, the bottom seal protrusion 27 is a seal portion of the laminated parison in blow molding using a cylindrical laminated parison including the outer layer 11 and the inner layer 13. The bottom seal protrusion 27 includes a base portion 27d, a thin portion 27a, and a thick portion 27b having a thickness larger than that of the thin portion 27a in this order from the bottom surface 29 side.

  Immediately after blow molding, the bottom seal protrusion 27 is in a state of standing substantially perpendicular to the surface P defined by the peripheral region 29b, as shown in FIG. When an impact is applied to the container, the inner layers 13 in the welded portion 27c are easily separated from each other, and the impact resistance is insufficient. Therefore, in this embodiment, the thin-walled portion 27a is softened by blowing hot air to the bottom seal protruding portion 27 after blow molding, and the bottom seal protruding portion 27 is bent at the thin-walled portion 27a as shown in FIG. Yes. Thus, the impact resistance of the bottom seal protrusion 27 is improved by a simple process of simply bending the bottom seal protrusion 27. Further, as shown in FIG. 6B, the bottom seal protrusion 27 does not protrude from the surface P defined by the peripheral region 29b in a bent state. Thus, when the delamination container 1 is erected, the bottom seal protrusion 27 protrudes from the surface P, and the delamination container 1 is prevented from falling over.

  The base portion 27d is provided on the bottom surface 29 side of the thin portion 27a and is thicker than the thin portion 27a. The base portion 27d may be omitted, but the thin portion 27a is provided on the base portion 27d. By providing, the impact resistance of the bottom seal protrusion 27 can be further improved.

  Further, as shown in FIG. 1B, the concave region of the bottom surface 29 is provided so as to cross the entire bottom surface 29 in the longitudinal direction of the bottom seal protrusion 27. That is, the central concave region 29a and the peripheral concave region 29c are connected. With such a configuration, the bottom seal protrusion 27 is easily bent.

  Next, the layer configuration of the container body 3 will be described in more detail. The container body 3 includes an outer layer 11 and an inner layer 13.

  The outer layer 11 is composed of, for example, low density polyethylene, linear low density polyethylene, high density polyethylene, polypropylene, an ethylene-propylene copolymer, and a mixture thereof. The outer layer 11 may have a multi-layer configuration. For example, a configuration in which both sides of the repro layer are sandwiched between polypropylene layers may be employed. Here, the repro layer refers to a layer that is used by recycling burrs produced during the molding of the container. Moreover, the outer layer 11 is formed thicker than the inner layer 13 so that the restoring property becomes high.

  In this embodiment, the outer layer 11 includes a random copolymer layer made of a random copolymer between propylene and another monomer. The outer layer 11 may be a single layer of a random copolymer layer or may have a multiple layer configuration. For example, the structure which pinched | interposed the both sides of the repro layer with the random copolymer layer may be sufficient. By configuring the outer layer 11 with a random copolymer having a specific configuration, the shape restoring property, transparency, and heat resistance of the outer shell 12 can be improved.

  The random copolymer has a content of monomers other than propylene of less than 50 mol%, and preferably 5 to 35 mol%. Specifically, this content is, for example, 5, 10, 15, 20, 25, 30 mol%, and may be within a range between any two of the numerical values exemplified here. The monomer copolymerized with propylene may be any monomer that improves the impact resistance of the random copolymer when compared with a polypropylene homopolymer, and ethylene is particularly preferable. In the case of a random copolymer of propylene and ethylene, the ethylene content is preferably 5 to 30 mol%, specifically, for example, 5, 10, 15, 20, 25, 30 mol%, and the numerical values exemplified here It may be within the range between any two. The weight average molecular weight of the random copolymer is preferably from 100,000 to 500,000, more preferably from 100,000 to 300,000. Specifically, the weight average molecular weight is, for example, 10, 15, 20, 25, 30, 35, 40, 45, 500,000, and is within a range between any two of the numerical values exemplified here. Also good.

The tensile modulus of the random copolymer is preferably 400 to 1600 MPa, and preferably 1000 to 1600 MPa. This is because the shape restoring property is particularly good when the tensile elastic modulus is in such a range. Specifically, the tensile elastic modulus is, for example, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600 MPa, and between any two of the numerical values exemplified here It may be within the range.
In addition, since the usability | use_condition of a container will worsen if a container is excessively hard, you may comprise the outer layer 11 by mixing a flexible material, such as a linear low density polyethylene, for example in a random copolymer. However, the material to be mixed with the random copolymer is preferably mixed so as to be less than 50% by weight with respect to the whole mixture so as not to significantly inhibit the effective characteristics of the random copolymer. For example, the outer layer 11 can be made of a material in which a random copolymer and linear low-density polyethylene are mixed at a weight ratio of 85:15.

  As shown in FIG. 7, the inner layer 13 is provided between the EVOH layer 13a provided on the outer surface side of the container, the inner surface layer 13b provided on the inner surface side of the container of the EVOH layer 13a, and between the EVOH layer 13a and the inner surface layer 13b. The adhesive layer 13c is provided. By providing the EVOH layer 13a, the gas barrier property and the peelability from the outer layer 11 can be improved.

  The EVOH layer 13a is a layer made of an ethylene-vinyl alcohol copolymer (EVOH) resin, and is obtained by hydrolysis of ethylene and vinyl acetate copolymer. The ethylene content of the EVOH resin is, for example, 25 to 50 mol%, and preferably 32 mol% or less from the viewpoint of oxygen barrier properties. Although the minimum of ethylene content is not prescribed | regulated, since the softness | flexibility of EVOH layer 13a tends to fall, so that ethylene content is small, 25 mol% or more is preferable. The EVOH layer 13a preferably contains an oxygen absorbent. By containing the oxygen absorbent in the EVOH layer 13a, the oxygen barrier property of the EVOH layer 13a can be further improved. The bending elastic modulus of the EVOH resin is preferably 2350 MPa or less, and more preferably 2250 MPa or less. The lower limit of the bending elastic modulus of the EVOH resin is not particularly specified, but is, for example, 1800, 1900, or 2000 MPa. The flexural modulus can be measured by a test method based on ISO178. The test speed is 2 mm / min.

  The melting point of the EVOH resin is preferably higher than the melting point of the random copolymer constituting the outer layer 11. The outside air introduction hole 15 is preferably formed in the outer layer 11 using a heating type punching device, but the outside air introduction hole 15 is formed in the outer layer 11 by making the melting point of the EVOH resin higher than the melting point of the random copolymer. When forming, the hole is prevented from reaching the inner layer 13. From this point of view, the difference between (the melting point of EVOH) − (the melting point of the random copolymer layer) should be large, preferably 15 ° C. or higher, and particularly preferably 30 ° C. or higher. The difference in melting point is, for example, 5 to 50 ° C., specifically, for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 ° C., and any of the numerical values exemplified here. Or within a range between the two.

  The inner surface layer 13b is a layer that comes into contact with the contents of the delamination container 1, and is, for example, a polyolefin such as low density polyethylene, linear low density polyethylene, high density polyethylene, polypropylene, ethylene-propylene copolymer, and a mixture thereof. It is preferably made of low-density polyethylene or linear low-density polyethylene. 50-300 MPa is preferable and, as for the tensile elasticity modulus of resin which comprises the inner surface layer 13b, 70-200 MPa is preferable. This is because the inner surface layer 13b is particularly flexible when the tensile elastic modulus is in such a range. The tensile modulus is specifically, for example, specifically, for example, 50, 100, 150, 200, 250, 300 MPa, and may be within a range between any two of the numerical values exemplified here. .

  The adhesive layer 13c is a layer having a function of adhering the EVOH layer 13a and the inner surface layer 13b. For example, an acid-modified polyolefin having a carboxyl group introduced into the above-described polyolefin (eg, maleic anhydride-modified polyethylene) is added. And ethylene vinyl acetate copolymer (EVA). An example of the adhesive layer 13c is a mixture of low-density polyethylene or linear low-density polyethylene and acid-modified polyethylene.

Next, an example of the manufacturing method of the lamination peeling container 1 of this embodiment is demonstrated.
First, as shown in FIG. 9A, a laminated structure corresponding to the container body 3 to be manufactured (one example is PE layer / adhesive layer / EVOH layer in order from the container inner surface side as shown in FIG. 9A). The laminated parison in a molten state having a / PP layer laminated structure) is extruded, the laminated parison in the molten state is set in a blow mold, and the divided mold is closed.
Next, as shown in FIG. 9B, a blow nozzle is inserted into the opening on the mouth 9 side of the container body 3, and air is blown into the cavity of the split mold while the mold is clamped.

  Next, as shown in FIG. 9C, the split mold is opened and the blow molded product is taken out. The split mold has a cavity shape such that various shapes of the container body 3 such as the valve member mounting recess 7a, the air circulation groove 7b, and the bottom seal protrusion 27 are formed in the blow molded product. Further, the split mold is provided with a pinch-off portion below the bottom seal protrusion 27, and a lower burr is formed at a lower portion of the bottom seal protrusion 27, and is thus removed.

Next, as shown in FIG.9 (d), the taken-out blow molded product is aligned.
Next, as shown in FIG. 9 (e), a hole is made only in the outer layer 11 in the upper cylindrical portion 31 provided on the upper side of the mouth portion 9, and a blower 33 is used between the outer layer 11 and the inner layer 13. By blowing air, the inner layer 13 is preliminarily peeled from the outer layer 11 at a portion (valve member mounting recess 7a) of the accommodating portion 7 where the valve member 5 is mounted. This preliminary peeling facilitates the step of forming the outside air introduction hole 15 and the step of mounting the valve member 5. In addition, you may cover the front end side of the upper cylindrical part 31 with a cover member so that the blown air may not leak from the front end side of the upper cylindrical part 31. In order to make it easy to make a hole only in the outer layer 11, the inner layer 13 may be peeled from the outer layer 11 in the upper cylindrical part 31 by crushing the upper cylindrical part 31 before making the hole. Well, the preliminary peeling may be performed on the entire housing portion 7 or may be performed on a part of the housing portion 7.
Next, as shown in FIG. 9 (f), an outside air introduction hole 15 is formed in the outer shell 12 using a drilling device. The outside air introduction hole 15 is preferably a round hole, but may have another shape.
Next, as shown in FIG. 10A, hot air is applied to the bottom seal protrusion 27 to soften the thin portion 27 a, and the bottom seal protrusion 27 is bent.
Next, as shown in FIG. 10B, the valve member 5 is inserted into the outside air introduction hole 15.
Next, as shown in FIG.10 (c), the upper cylindrical part 31 is cut.
Next, as shown in FIG. 10 (d), the inner bag 14 is inflated by blowing air into the inner bag 14.
Next, as shown in FIG. 10E, the inner bag 14 is filled with contents.
Next, as shown in FIG. 10 (f), the cap 23 is attached to the mouth portion 9.
Next, as shown in FIG. 10G, the housing portion 7 is covered with a shrink film to complete the product.

  The order of the various steps shown here can be changed as appropriate. For example, the hot air bending step may be performed before the outside air introduction hole opening step or before the inner layer preliminary peeling step. Further, the step of cutting the upper cylindrical portion 31 may be performed before the valve member 5 is inserted into the outside air introduction hole 15.

Further, the inner layer preliminary peeling and the outside air introduction hole opening step can be performed by the following method.
First, as shown in FIG. 11A, the air in the inner bag 14 is sucked from the mouth portion 9 to reduce the pressure in the inner bag 14. In that state, a punching device such as a heat pipe or a pipe cutter is slowly pressed against the outer layer 11. This perforating apparatus has a cylindrical cutter, and air inside the cylinder is sucked. In the state where the outer layer 11 is not perforated, air does not enter between the outer layer 11 and the inner layer 13, so that the inner layer 13 is not peeled from the outer layer 11.

  When the cylindrical cutter penetrates the outer layer 11, as shown in FIG. 11B, the cut excision piece is removed through the cylindrical cutter, and the outside air introduction hole 15 is formed. At this moment, air enters between the outer layer 11 and the inner layer 13, and the inner layer 13 is peeled from the outer layer 11.

  Next, as shown in FIG.11 (c), the outside-air introduction hole 15 is expanded using a drilling apparatus. In addition, when forming the external air introduction hole 15 large enough for insertion of the valve member 5 in the steps of FIGS. 11A to 11B, the diameter expansion step of FIG. 11C is not necessary.

Next, the principle of operation when using the manufactured product will be described.
As shown in FIGS. 12A to 12C, the product filled with the contents is tilted and the side surface of the outer shell 12 is grasped and compressed to discharge the contents. At the start of use, since there is substantially no gap between the inner bag 14 and the outer shell 12, the compressive force applied to the outer shell 12 directly becomes the compressive force of the inner bag 14, and the inner bag 14 is compressed. The contents are discharged.

  The cap 23 incorporates a check valve (not shown), and can discharge the contents in the inner bag 14, but cannot take outside air into the inner bag 14. Therefore, when the compressive force applied to the outer shell 12 after discharging the contents is removed, the outer shell 12 tries to return to its original shape by its own restoring force, but the inner bag 14 remains deflated and only the outer shell 12 remains. Will expand. Then, as shown in FIG. 12 (d), the inside of the intermediate space 21 between the inner bag 14 and the outer shell 12 is in a reduced pressure state, and outside air enters the intermediate space 21 through the outside air introduction hole 15 formed in the outer shell 12. be introduced. When the intermediate space 21 is in a reduced pressure state, the lid 5c is not pressed against the outside air introduction hole 15, and thus does not hinder the introduction of outside air. In addition, the locking portion 5b is provided with airway securing means such as a protrusion 5d and a groove so that the locking portion 5b does not hinder the introduction of outside air even when the locking portion 5b is in contact with the outer shell 12.

  Next, as shown in FIG. 12 (e), when the side surface of the outer shell 12 is gripped and compressed again, the lid 5 c closes the outside air introduction hole 15, thereby increasing the pressure in the intermediate space 21. The compressive force applied to the outer shell 12 is transmitted to the inner bag 14 through the intermediate space 21, and the inner bag 14 is compressed by this force and the contents are discharged.

  Next, as shown in FIG. 12 (f), when the compressive force applied to the outer shell 12 after the discharge of the contents is removed, the outer shell 12 introduces outside air into the intermediate space 21 from the outside air introduction hole 15. It is restored to its original shape by its own restoring force.

  In the following examples / comparative examples, various delamination containers having different layer configurations are manufactured by blow molding, and restoration properties, rigidity, impact resistance, heat resistance, transparency, gas barrier properties, moldability, outer layer workability, etc. Various evaluations were performed. The outer layer workability indicates the ease of processing by forming an outside air introduction hole only in the outer layer using a heating type punching device.

<Example 1>
In Example 1, the layer configuration was random copolymer layer / EVOH layer / adhesive layer / LLDPE layer in order from the outside of the container. For the random copolymer layer, a random copolymer of propylene and ethylene (type: Novatec EG7FTB, manufactured by Nippon Polypro Co., Ltd., melting point 150 ° C.) was used. For the EVOH layer, a high melting point EVOH (model: Soarnol SF7503B, manufactured by Nippon Synthetic Chemical Co., Ltd., melting point 188 ° C., flexural modulus 2190 MPa) was used. When the above various evaluations were performed, excellent results were obtained for all evaluation items.

<Example 2>
In Example 2, the layer configuration was random copolymer layer / repro layer / random copolymer layer / EVOH layer / adhesive layer / LLDPE layer in order from the outside of the container. The repro layer is made of a material obtained by recycling burrs formed at the time of molding the container, but the composition is very close to that of the random copolymer layer. The random copolymer layer and the EVOH layer were formed of the same material as in Example 1. When the above various evaluations were performed, excellent results were obtained for all evaluation items.

<Example 3>
In Example 3, the layer structure is the same as in Example 1, but low-melting-point EVOH (model: Soarnol A4412, Nippon Synthetic Chemical Co., Ltd., melting point 164 ° C.) was used for the EVOH layer. When the above various evaluations were performed, excellent results were obtained for all evaluation items other than the outer layer workability, but the outer layer workability was slightly inferior to that of Example 1. This result proves that the difference of (melting point of EVOH) − (melting point of random copolymer layer) is preferably 15 ° C. or more.

<Comparative Example 1>
In Comparative Example 1, the layer configuration was LDPE layer / EVOH layer / adhesive layer / LLDPE layer in order from the outside of the container. When the above various evaluations were performed, at least rigidity and heat resistance were low.

<Comparative example 2>
In Comparative Example 2, the layer configuration was HDPE layer / EVOH layer / adhesive layer / LLDPE layer in order from the outside of the container. When the above various evaluations were performed, at least restoration and transparency were low.

<Comparative Example 3>
In Comparative Example 3, the layer configuration was polypropylene layer / EVOH layer / adhesive layer / LLDPE layer in order from the outside of the container. As a material for the polypropylene layer, a homopolymer of propylene having a melting point of 160 ° C. was used. The same material as in Example 1 was used for the EVOH layer. When the above various evaluations were performed, at least the impact resistance was low. Further, the outer layer workability was inferior to that of Example 1.

<Comparative example 4>
In Comparative Example 4, the layer configuration was block copolymer layer / EVOH layer / adhesive layer / LLDPE layer in order from the outside of the container. When the above various evaluations were performed, at least transparency and impact resistance were low.

<Comparative Example 5>
In Comparative Example 5, the layer configuration was PET layer / EVOH layer / adhesive layer / LLDPE layer in order from the outside of the container. When the above various evaluations were performed, at least the moldability and heat resistance were low.

<Comparative Example 6>
In Comparative Example 6, the layer configuration was polyamide layer / EVOH layer / adhesive layer / LLDPE layer in order from the outside of the container. When the above various evaluations were performed, at least the moldability was low.

<Comparative Example 7>
In Comparative Example 6, the layer configuration was polypropylene layer / polyamide layer / adhesive layer / LLDPE layer in order from the outside of the container. When the above various evaluations were performed, at least gas barrier properties and moldability were low.

<Bend resistance test>
The EVOH resin used as the EVOH layer was subjected to a flex resistance test using a gelbo flex tester (manufactured by Brugger, KFT-C-Flex Durability Tester) in accordance with ASTM F392. The test environment was 23 ° C. and 50% RH.
First, a sample made of a single layer film of 28 cm × 19 cm × 30 μm was prepared.
Next, both ends of the sample were fixed to the pair of mandrels A and B by winding the long side of the sample around a pair of mandrels (diameter 90 mm) arranged with an interval of 180 mm.
Next, while mandrel A was fixed, mandrel B was gradually approached while twisting, and when the twisting angle was 440 degrees and the horizontal movement distance was 9.98 cm, the twisting was stopped. Thereafter, the horizontal movement of the mandrel B was continued, and the horizontal movement was stopped when the horizontal movement distance after stopping the twisting was 6.35 cm. Thereafter, the mandrel B was returned to the initial state by the reverse operation to that described above. After performing such an operation 100 times, the presence or absence of pinholes was examined. The results are shown in Table 1.

  SF7503B in Table 1 is an EVOH resin used as the EVOH layer in Example 1. On the other hand, D2908 in Table 1 is Soarnol D2908 (manufactured by Nippon Synthetic Chemical Company), which is a general EVOH resin. Two tests were performed for each EVOH resin.

  As shown in Table 1, in the above test, a large number of pinholes were formed in D2908, whereas SF7503B did not have any pinholes, and had better bending resistance than a general EVOH resin. I understood that.

(Appendix)
Hereinafter, problems of the original application specification, solving means, and preferred embodiments will be added.

  As an outer layer of the delamination container of Patent Document 1, it is considered preferable to use a polyethylene resin in order to maintain the external shape of the container.

  However, as a result of studies by the inventor, depending on the use method and environment of the delamination container, the shape recovery of the outer shell is not sufficient, and in particular, the lamination of the method of discharging the contents by pressing the outer shell In the peeling container, it is desired to improve the shape restoring property of the outer shell. Further, such a delamination container is desired to be excellent in transparency and heat resistance. However, the delamination container of Patent Document 1 has insufficient transparency and heat resistance depending on the usage method and environment. It turns out that there is a case.

This invention is made | formed in view of such a situation, and provides the lamination | stacking peeling container excellent in the shape restoration property, transparency, and heat resistance of an outer shell.
(Means for solving the problem)

  According to the present invention, there is provided a delamination container including an outer layer and an inner layer, wherein the inner layer peels from the outer layer and shrinks as the content decreases, and the outer layer is between propylene and another monomer. A delamination container including a propylene copolymer layer made of a random copolymer is provided.

  The present inventor examined various materials constituting the outer shell that should improve the shape restoring property, transparency, and heat resistance of the outer shell, and found that propylene composed of a random copolymer between propylene and another monomer. When the outer shell was constituted by the copolymer layer, it was discovered that the shape restoring property, transparency and heat resistance of the outer shell could be improved, and the present invention was completed.

Hereinafter, various embodiments of the present invention will be exemplified. The following embodiments can be combined with each other.
Preferably, the inner layer includes an EVOH layer made of EVOH, and the melting point of the EVOH is higher than that of the random copolymer.
Preferably, the EVOH has a melting point of 15 ° C. or more higher than the melting point of the random copolymer.
Preferably, the inner layer includes a polyethylene layer via an adhesive layer on the inner surface side of the container from the EVOH layer.

1: Laminated peeling container, 3: Container body, 5: Valve member, 7: Housing part, 9: Mouth part, 11: Outer layer, 12: Outer shell, 13: Inner layer, 14: Inner bag, 15: Outside air introduction hole, 23: Cap, 27: Bottom seal protrusion

Claims (7)

A laminated peeling container comprising an outer layer and an inner layer, wherein an inner bag constituted by the inner layer peels and shrinks from an outer shell constituted by the outer layer as the contents are reduced,
The inner layer includes an EVOH layer made of EVOH as an outermost layer,
The EVOH has an ethylene content of 32 mol% or less and a flexural modulus of 2350 MPa or less.
Delamination container. The laminated peeling container according to claim 1, wherein the EVOH has an ethylene content of 25 mol% or more. The laminate peeling container according to claim 1 or 2 , wherein the EVOH has a flexural modulus of 1800 MPa or more. The said outer layer is a delamination container as described in any one of Claims 1-3 provided with the repro layer which recycled and used the burr | flash which came out at the time of the shaping | molding of the said delamination container. The inner layer includes an inner surface layer provided on the container inner surface side of the EVOH layer, and an adhesive layer provided between the EVOH layer and the inner surface layer,
The laminate peeling container according to any one of claims 1 to 4 , wherein a tensile elastic modulus of a resin constituting the inner surface layer is 70 to 200 MPa. The inner layer includes an inner surface layer provided on the container inner surface side of the EVOH layer, and an adhesive layer provided between the EVOH layer and the inner surface layer,
The said inner surface layer is a lamination peeling container as described in any one of Claims 1-5 which consists of a linear low density polyethylene. Pre-peeling the inner bag of the delamination container according to any one of claims 1 to 6 from the outer shell;
Inflating the inner bag before filling the contents in the inner bag;
A method for producing a delamination container with contents, comprising a step of filling the contents in the inner bag after the inner bag is inflated.