JP6547864B2 - Packaging material and packaging container using the same - Google Patents

Description

  The present invention relates to a packaging material used for a container for storing food, medicine and the like, and a packaging container using the same.

  Conventionally, as a packaging material used for a packaging container, a base material layer made of a paper substrate, a barrier layer for preventing gas permeation, a heat seal layer made of a heat adhesive resin, a barrier layer and a heat seal layer are bonded A laminate having an adhesive layer was used. Here, a low density polyethylene resin was used for the heat seal layer, and a polyurethane adhesive, which is an adhesive for dry lamination, was used for the adhesive layer. In a packaging container formed using this packaging material, alcoholic beverages such as sake and shochu and non-alcoholic beverages such as coffee and fruit beverages are packaged. However, there has been a problem that the odorous component resulting from the solvent of the polyurethane adhesive used in the adhesive layer passes through the heat seal layer and migrates into the contents, thereby impairing the quality of the contents, in particular, the taste.

  In order to solve this problem, in Patent Document 1, the heat seal layer contains a layer comprising a cyclic olefin copolymer. The cyclic olefin copolymer has the property of being difficult to permeate the odor resulting from the solvent of the polyurethane adhesive. For this reason, permeation of the odor resulting from the solvent of a polyurethane-type adhesive agent can be interrupted | blocked by a heat seal layer, and the quality degradation of the packaged content can be prevented.

JP 2008-221606 A

  However, according to the packaging material, components such as alcohol contained in the contents in the packaging container permeate the heat seal layer, reach the barrier layer, and are accumulated between the barrier layer and the heat seal layer. For this reason, the adhesive layer which consists of a polyurethane-type adhesive agent deteriorates by use for many years, and there existed a problem which a delamination generate | occur | produces between a barrier layer and a heat seal layer.

  An object of the present invention is to provide a packaging material which prevents delamination of a barrier layer and a heat seal layer in view of the above-mentioned problems.

  In order to achieve the above object, the present invention is a packaging material in which at least a base material layer, a barrier layer having a gas barrier property, and a heat seal layer made of a heat adhesive resin are sequentially laminated, And an ethylene methacrylic acid copolymer disposed on the side of the barrier layer and an adhesive layer adhering to the side of the barrier layer and a layer comprising the cyclic olefin copolymer, and an adhesive layer adhering to the side of the heat seal layer. It is characterized by being made of linear low density polyethylene.

Further, according to the present invention, in the packaging material having the above structure, the melting point of the linear low density polyethylene and the ethylene methacrylic acid copolymer constituting the adhesive layer is 100 ° C. or less, and the density of the linear low density polyethylene is 0. It is characterized in that it is less than .92 g / cm ³ , and the acid content of the ethylene methacrylic acid copolymer is less than 10% by mass percentage.

  The present invention is the packaging material according to the above structure, wherein the packaging material comprises at least a base material layer, a barrier layer having gas barrier properties, and a heat seal layer made of a heat adhesive resin, which are sequentially laminated. Is characterized in that it comprises a layer comprising a cyclic olefin copolymer, and an adhesive layer for bonding the barrier layer and the heat seal layer comprises an ethylene methacrylic acid copolymer having a thickness of 25 μm or more.

  Further, according to the present invention, in the packaging material having the above structure, the melting point of the ethylene methacrylic acid copolymer constituting the adhesive layer is 100 ° C. or less and the acid content of the ethylene methacrylic acid copolymer is less than 10% by mass It is characterized by being.

  Further, the present invention is characterized in that, in the packaging material having the above-described structure, the adhesive layer is formed by melt extrusion.

  The present invention is further characterized in that the heat seal layer has a layer of linear low density polyethylene having a thickness of 5 μm or less on the side opposite to the adhesive layer.

  Further, according to the present invention, in the packaging material having the above structure, the heat seal layer is formed of a blend resin of a linear low density polyethylene having a thickness of 10 μm or less and a cyclic olefin copolymer on the surface opposite to the adhesive layer. It is characterized by having a layer.

  Further, the present invention is characterized in that, in the packaging material having the above-described structure, the heat seal layer has a layer made of a cyclic olefin copolymer on the surface in contact with the adhesive layer.

  Further, the present invention is characterized in that, in the packaging material having the above-mentioned structure, the heat seal layer has a layer made of linear low density polyethylene on the surface in contact with the adhesive layer.

  Furthermore, the present invention is characterized in that, in the packaging material of the above-mentioned configuration, the base material layer includes a paper base material.

  Further, according to the present invention, there is provided a packaging container comprising the packaging material of the above configuration, wherein the end of the packaging material is heat-sealed.

  Further, the present invention is a packaging container comprising the packaging material of the above configuration, which is formed by heat sealing the end portion of the packaging material, and the heat sealing strength of the heat sealing portion is 25 N / 15 mm or more. There is.

  According to the present invention, the barrier layer and the heat seal layer are adhered by the adhesive layer made of the ethylene methacrylic acid copolymer disposed on the barrier layer side and the linear low density polyethylene disposed on the heat seal layer side. As a result, the barrier layer and the ethylene methacrylic acid copolymer are firmly adhered, and the heat seal layer and the linear low density polyethylene are firmly adhered. In addition, the interlayer adhesion strength between linear low density polyethylene and ethylene methacrylic acid copolymer is also high. Therefore, the barrier layer and the heat seal layer can be bonded with high lamination strength. In addition, ethylene methacrylic acid copolymer and linear low density polyethylene are less likely to deteriorate even after many years of use compared to adhesives for dry lamination, and there is little odor due to solvents. Therefore, while being able to prevent the delamination between a barrier layer and a heat seal layer, the odor component which permeate | transmits a heat seal layer can be reduced, and the initial quality of the content can be kept favorable.

  Further, according to the present invention, the barrier layer and the heat seal layer are bonded by the adhesive layer made of an ethylene methacrylic acid copolymer having a thickness of 25 μm or more. Thereby, the barrier layer and the heat seal layer can be bonded with high laminating strength. Ethylene methacrylic acid copolymers are less likely to deteriorate over many years of use as compared to dry lamination adhesives, and have less odor due to solvents. Therefore, while being able to prevent the delamination between a barrier layer and a heat seal layer, the odor component which permeate | transmits a heat seal layer can be reduced, and the initial quality of the content can be kept favorable.

The perspective view of the packaging container concerning a 1st embodiment of the present invention Schematic sectional drawing which shows the laminated constitution of the packaging material which concerns on 1st Embodiment of this invention Schematic sectional drawing which shows the laminated constitution of the heat seal layer of the packaging material which concerns on 1st Embodiment of this invention Schematic sectional drawing which shows the laminated constitution of the packaging material which concerns on 2nd Embodiment of this invention

First Embodiment
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of the packaging container 10 according to the first embodiment.

  The packaging container 10 is formed into a box shape by overlapping the end portions of the packaging material 110 (see FIG. 2) cut into a predetermined shape and heat sealing the heat sealed portions 11a and 11b with a predetermined width. In the heat seal portion 11a, the heat seal layer 116 (see FIG. 2) of the innermost layer of the packaging material 110 is oppositely heat sealed. The heat seal portion 11 b is heat sealed by the skiving method. Specifically, the outermost layer side of the edge of the packaging material 110 is cut off (skived) with a predetermined thickness, and the heat seal layer 116 disposed in the innermost layer is folded back to the outermost layer and hemmed, The heat seal layer 116 folded back to the outer layer side and the heat seal layer 116 overlapping with each other are opposed and heat sealed. This prevents the cross section from coming into contact with the content at the edge of the packaging material 110, contaminates the content, or penetrates through the paper layer of the packaging material 110 so that the content component penetrates and the strength of the laminate decreases. It is possible to prevent problems such as delamination, sealing failure and the like. Non-alcoholic beverages such as fruit juices, juices, teas, coffee, milk drinks, soups, etc., alcoholic beverages such as sake, shochu etc., medicines containing menthol ingredients, etc. are enclosed inside the packaging container 10 as contents (not shown) ing.

  FIG. 2 is a schematic cross-sectional view showing the layer structure of the packaging material 110. The packaging material 110 is made of a laminate in which a base material layer 112, a barrier layer 114, and a heat seal layer 116 are sequentially laminated. The base layer 112 and the barrier layer 114 are adhered via the adhesive layer 113. Also, the barrier layer 114 and the heat seal layer 116 are bonded via the adhesive layer 115.

  The base layer 112 is disposed on the outer surface side of the packaging container 10 (see FIG. 1) and is made of paper. In addition, on the upper surface of the base layer 112, a heat adhesive resin layer 117 made of polyethylene is formed. The heat adhesive resin layer 117 is formed by melt-extruding polyethylene on the upper surface of the base layer 112. The heat adhesive resin layer 117 imparts water resistance to the packaging container 10 formed of the packaging material 110. Further, printing is applied to the upper surface of the heat adhesive resin layer 117.

  The base layer 112 imparts rigidity, stiffness, strength and the like to the packaging container 10. Specifically, various types of paper such as pure white roll paper, kraft paper, paperboard, processed paper can be used.

  The adhesive layer 113 is made of a resin layer which adheres the base layer 112 and the barrier layer 114 by a method such as dry lamination method, extrusion lamination method, coextrusion lamination method, thermal lamination method and the like. In the dry lamination method, for example, a polyurethane adhesive is used. The extrusion resin used in the extrusion lamination method and the coextrusion lamination method is less likely to deteriorate the adhesive layer even after many years of use compared to the adhesive used in the dry lamination method, and between the substrate layer 112 and the barrier layer 114 It is difficult for delamination to occur. Therefore, it is preferable to use an extrusion laminating method or a coextrusion laminating method.

  The barrier layer 114 has gas barrier properties to prevent water vapor and oxygen from invading the inside of the packaging container 10 from the outside, and the components of the contents to the outside of the packaging container 10 (for example, odor component, alcohol component, menthol component Etc.) to prevent leakage. For the barrier layer 114, a heat resistant resin film (for example, polyethylene terephthalate or polyethylene naphthalate), a heat resistant resin film on which an inorganic compound (silicon oxide, alumina, silica or the like) is vapor deposited, metal foil (aluminum, nickel or the like) It can be used. In addition, in the heat resistant resin film which vapor-deposited the inorganic compound, the vapor deposition surface of the vapor-deposited inorganic compound is distribute | arranged to the contact layer 113 side.

  The adhesive layer 115 adheres the barrier layer 114 and the heat seal layer 116, and has an upper layer portion 115a disposed on the barrier layer 114 side and a lower layer portion 115b disposed on the heat seal layer 116 side. The upper layer portion 115a is made of ethylene methacrylic acid copolymer (EMMA), and the lower layer portion 115b is made of linear low density polyethylene (LLDPE).

  The barrier layer 114 (heat-resistant resin film or metal foil) and the upper layer portion 115a made of ethylene methacrylic acid copolymer are firmly bonded, and the heat seal layer 116 and the lower layer portion 115b are strongly bonded. In addition, the interlayer adhesion strength between linear low density polyethylene and ethylene methacrylic acid copolymer is also high. Therefore, even without using an adhesive such as an anchor coating agent, the barrier layer 114 and the heat seal layer 116 are bonded with high lamination strength via the ethylene methacrylic acid copolymer and the linear low density polyethylene. In addition, ethylene methacrylic acid copolymer and linear low density polyethylene are less likely to deteriorate even after many years of use compared to adhesives for dry lamination, and there is little odor due to solvents. Therefore, while being able to prevent the delamination between the barrier layer 114 and the heat seal layer 116, the odor component which permeate | transmits the heat seal layer 116 can be reduced, and the initial quality of the content can be kept favorable.

  The adhesive layer 115 is preferably made of a co-extruded resin of ethylene methacrylic acid copolymer and linear low density polyethylene. In this case, the melted ethylene methacrylic acid copolymer and linear low density polyethylene are coextruded on the surface of the barrier layer 114, and the resin film constituting the heat seal layer 116 is bonded. Thereby, the barrier layer 114 and the heat seal layer 116 can be easily bonded.

The melting point of the ethylene methacrylic acid copolymer and the linear low density polyethylene constituting the adhesive layer 115 is preferably 100 ° C. or less. Thereby, high lamination strength is obtained even if these resins are melt-extruded at low temperature. In addition, the melt extrusion at a low temperature can reduce the generation of the odor of ethylene methacrylic acid copolymer and linear low density polyethylene. At this time, by setting the density of the linear low density polyethylene to be less than 0.92 g / cm ³ and the acid content of the ethylene methacrylic acid copolymer to be less than 10% by mass percentage, an ethylene methacrylic acid copolymer and The generation of odor of linear low density polyethylene can be further reduced.

  FIG. 3 is a schematic cross-sectional view showing an example of the layer configuration of the heat seal layer 116. As shown in FIG. The heat seal layer 116 is melted by heat and thermally fused to the opposing heat seal layers 116. Specifically, layers of linear low density polyethylene (hereinafter referred to as LLDPE layers 116a and 116c) are disposed on both sides of a layer (hereinafter referred to as COC layer 116b) formed of cyclic olefin copolymer (COC). It is done.

  The COC layer 116 b prevents permeation of the components of the adhesive layer 115 into the interior of the packaging container 10. Thereby, the components of the adhesive layer 115 do not migrate into the contents, and the initial quality of the contents can be well maintained.

  In addition, the COC layer 116 b prevents permeation of the components of the contents from the inside of the packaging container 10 to the adhesive layer 115 side. For example, when the content contains an alcohol component, permeation of the alcohol component to the adhesive layer 115 side can be suppressed. As a result, deterioration of the adhesive layer 115 can be prevented, and the occurrence of delamination between the barrier layer 114 and the upper layer portion 115a or delamination between the upper layer portion 115a and the lower layer portion 115b can be prevented. When the content contains a menthol component, permeation of the menthol component to the adhesive layer 115 can be suppressed. Thereby, it is possible to prevent the quality deterioration due to the reduction of the menthol component of the contents.

  Examples of cyclic olefin copolymers that constitute the COC layer 116 b include ethylene / cyclic olefin copolymer random copolymer, hydrogenated ring-opening copolymer of cyclic olefin copolymer, graft modified ethylene / cyclic olefin The copolymer random copolymer, the ring-opening copolymer of the graft modified cyclic olefin copolymer, etc. are mentioned.

  Further, the LLDPE layer 116c disposed in the innermost layer of the heat seal layer 116 is excellent in sealability, and the heat seal layers 116 are firmly thermally bonded by heat sealing. The heat seal layer 116 is also thermally bonded to the heat adhesive resin layer 117 provided on the outside of the base layer 112 with high heat seal strength. The LLDPE layer 116c preferably has a thickness of 5 μm or less. By setting the thickness of the LLDPE layer 116c to 5 μm or less, it is possible to prevent the components of the contents from being adsorbed and to prevent the deterioration of the contents. At this time, the heat sealing strength between the LLDPE layers 116c (by holding each LLDPE layer 116c after heat sealing cut to a width of 15 mm), the distance between the grips is 180 ° opposite to the resin flow direction, and the relative speed is 300 mm / min. By setting the heat seal strength) measured while peeling using a tensile tester to 25 N / 15 mm or more, high sealability can be obtained in the heat seal portions 11 a and 11 b of the packaging container 10.

  In addition, instead of the LLDPE layer 116c, a layer composed of a blend resin of linear low density polyethylene and cyclic olefin copolymer (hereinafter referred to as a blend resin layer) may be disposed in the innermost layer of the heat seal layer 116. . The blend resin layer preferably has a thickness of 10 μm or less. By setting the thickness of the blend resin layer to 10 μm or less, it is possible to prevent the adsorption of the components of the contents and to prevent the deterioration of the contents. At this time, the heat seal strength between the blend resin layers (by gripping each blend resin layer after heat sealing cut to a width of 15 mm), the distance between the grips is 180 ° opposite to the resin flow direction at a relative speed of 300 mm / min. By setting the heat seal strength) measured while peeling using a tensile tester to 25 N / 15 mm or more, high sealability can be obtained in the heat seal portions 11 a and 11 b of the packaging container 10.

  Further, since the LLDPE layer 116a disposed on the surface of the heat seal layer 116 in contact with the adhesive layer 115 is made of the same resin as the lower layer portion 115b, it is bonded with high lamination strength. Even if a layer made of a cyclic olefin copolymer is disposed on the surface of the heat seal layer 116 in contact with the adhesive layer 115, high laminate strength with the lower layer portion 115b can be obtained.

  As other laminated constitution of the heat seal layer 116, for example, four-layer constitution of cyclic olefin copolymer / linear low density polyethylene / cyclic olefin copolymer / linear low density polyethylene, linear low density polyethylene / The three-layer structure of the blend resin of cyclic olefin copolymer / linear low density polyethylene and cyclic olefin copolymer, etc. are mentioned. In addition, the component of the adhesive layer 115 which permeate | transmits the heat seal layer 116 and the component of the content can be reduced more by making the layer which consists of a cyclic olefin copolymer into a multilayer structure.

  According to the present embodiment, the barrier layer 114 and the heat seal layer 116 are made of the ethylene methacrylic acid copolymer disposed on the barrier layer 114 side and the adhesive layer 115 made of linear low density polyethylene disposed on the heat seal layer 116 side. And are glued. Thereby, the barrier layer 114 and the ethylene methacrylic acid copolymer are firmly adhered, and the heat seal layer 116 and the linear low density polyethylene are firmly adhered. In addition, the interlayer adhesion strength between linear low density polyethylene and ethylene methacrylic acid copolymer is also high. Therefore, the barrier layer 114 and the heat seal layer 116 can be bonded with high lamination strength. In addition, ethylene methacrylic acid copolymer and linear low density polyethylene are less likely to deteriorate even after many years of use compared to adhesives for dry lamination, and there is little odor due to solvents. Therefore, while being able to prevent the delamination between the barrier layer 114 and the heat seal layer 116, the odor component which permeate | transmits the heat seal layer 116 can be reduced, and the initial quality of the content can be kept favorable.

When the melting point of the linear low density polyethylene and ethylene methacrylic acid copolymer constituting the adhesive layer 115 is 100 ° C. or less, even if these resins are melt-extruded at low temperature, the barrier layer 114 and the heat seal layer 116 High laminate strength is obtained. In addition, the resinous odor of the linear low density polyethylene and the ethylene methacrylic acid copolymer can be suppressed by melt extrusion at a low temperature. Further, by setting the density of the linear low density polyethylene to be less than 0.92 g / cm ³ and the acid content of the ethylene methacrylic acid copolymer to be less than 10% by mass percentage, the linear low density polyethylene and ethylene The generation of odor of methacrylic acid copolymer can be further reduced.

  When the heat seal layer 116 has a linear low density polyethylene having a thickness of 5 μm or less on the surface on the innermost layer side, or a linear low density polyethylene and cyclic olefin having a thickness of 10 μm or less on the surface on the innermost layer side. In the case of having a layer made of a blend resin with a copolymer, it is possible to prevent the adsorption of the components of the contents in the heat seal layer 116 and to prevent the deterioration of the contents.

  In addition, the heat seal layer 116 has a layer made of a cyclic olefin copolymer or a layer made of linear low density polyethylene on the surface in contact with the adhesive layer 115 to form a layer made of the cyclic olefin copolymer and the adhesive layer 115. The linear low density polyethylene can be strongly adhered, and the occurrence of delamination between the barrier layer 114 and the heat seal layer 116 can be further prevented.

  Further, by setting the heat seal strength of the heat seal layer 116 to 25 N / 15 mm in the heat seal portion 11 b after forming the packaging container 10, high sealing performance can be obtained in the heat seal portion 11 b of the packaging container 10.

Second Embodiment
FIG. 4 is a schematic cross-sectional view showing the layer structure of the packaging material 110 according to the second embodiment. For convenience of explanation, the same reference numerals are given to the same descriptions as those of the first embodiment shown in FIGS. In the packaging material 110 of the present embodiment, the adhesive layer 115 is formed only of an ethylene methacrylic acid copolymer having a thickness of 25 μm or more. If the thickness of the ethylene methacrylic acid copolymer is 25 μm or more, the barrier layer 114 and the heat seal layer 116 can be bonded with high lamination strength without using an adhesive such as an anchor coating agent. In addition, ethylene methacrylic acid copolymer is less likely to deteriorate over many years of use as compared with adhesives for dry lamination, and there is little odor due to solvents. Therefore, while being able to prevent the delamination between the barrier layer 114 and the heat seal layer 116, the odor component which permeate | transmits the heat seal layer 116 can be reduced, and the initial quality of the content can be kept favorable.

  At this time, the melting point of the ethylene methacrylic acid copolymer is preferably 100 ° C. or less. Thereby, high laminate strength can be obtained even if the ethylene methacrylic acid copolymer is melt-extruded at a low temperature. In addition, the melt extrusion at a low temperature can reduce the generation of the odor of the ethylene methacrylic acid copolymer. Further, the acid content of the ethylene methacrylic acid copolymer is preferably less than 10% by mass percentage. As a result, when the barrier layer 114 contains polyethylene terephthalate, high laminate strength can be obtained between the adhesive layer 115 and the polyethylene terephthalate even if melt extrusion is performed at a low temperature.

  The present invention is not limited to the above-described embodiment, and the present invention also includes the case where the base material layer 112 is configured in multiple layers or the case where the paper base material is not included. For example, the pouch-like packaging container 10 formed by the packaging material 110 which made the base material layer 112 the outermost layer is also included in this invention. In this case, various films such as a polyethylene terephthalate film, a biaxially stretched nylon film, and a biaxially stretched polypropylene film can be used as the base material layer 112. When the pouch-like packaging container 10 is formed or the skive hemming method is not used, the heat seal strength between the heat seal layer 116 and the base material layer 112 and the heat between the heat seal layer 116 and the heat adhesive resin layer 117 Seal strength (Heat-sealed heat seal layer 116 and heat-adhesive resin layer 117 cut to a width of 15 mm are grasped, and tension is applied at a relative speed of 300 mm / min in the opposite direction 180 degrees along the resin flow direction It is preferable to set the heat seal strength (measured) while peeling using a tester to 25 N / 15 mm or more. Thereby, the packaging container 10 formed by heat-sealing the innermost layer and the outermost layer at the edge of the packaging material 110 can obtain high sealing performance.

  Next, the effects of the present invention will be specifically described using examples and comparative examples. In the following experiments, evaluations were made on the laminate strength of the packaging material 110 and the quality retention performance and non-adsorbability to contents.

  Table 1 shows the layer configuration of the adhesive layer 115 and the layer configuration of the heat seal layer 116 of the packaging materials according to Examples 1 to 6 and Comparative Examples 1 to 8 described below.

The barrier layer 114 of the packaging material 110 according to the first embodiment is formed of a polyethylene terephthalate film having a thickness of 12 μm. The upper layer portion 115a of the adhesive layer 115 is formed of an ethylene methacrylic acid copolymer (AN 4228C manufactured by Mitsui DuPont Chemical Co., Ltd.) having a thickness of 10 μm and an acid content of 4%. The lower layer portion 115b of the adhesive layer 115 is formed of linear low density polyethylene (manufactured by Prime Polymer Co., Ltd., SP1071C) having a thickness of 20 μm, a density of 0.91 g / cm ^{3 and a} melting point of 100 ° C.

  In the heat seal layer 116, cyclic olefin copolymer (thickness 5 μm), linear low density polyethylene (thickness 15 μm), cyclic olefin copolymer (thickness 5 μm), linear low density polyethylene (thickness 5 μm) The sealant film laminated | stacked in order of was used. Then, the packaging material 110 is formed by a melt coextrusion method in which the ethylene methacrylic acid copolymer of the adhesive layer 115 and linear low density polyethylene are coextruded on the barrier layer 114 and the sealant film of the heat seal layer 116 is laminated. . At this time, the cyclic olefin copolymer of the heat seal layer 116 was disposed on the adhesive layer 115 side, and the linear low density polyethylene was disposed on the opposite side of the adhesive layer 115.

Further, the adhesive layer 113 was formed of a 20 μm thick ethylene methacrylic acid copolymer (AN4228C manufactured by Mitsui DuPont Chemical Co., Ltd.), and the barrier layer 114 and the base material layer 112 (basis weight 360 g / m ² ) were adhered. . The heat adhesive resin layer 117 is formed by extrusion resin to a thickness of 25 μm, and the upper surface of the heat adhesive resin layer 117 is formed with a print layer.

  The packaging material 110 according to the second embodiment has the same layer configuration except for the packaging material 110 according to the first embodiment and the heat seal layer 116. The heat seal layer 116 of the packaging material 110 according to Example 2 is formed by laminating linear low density polyethylene (thickness 20 μm), cyclic olefin copolymer (thickness 5 μm), linear low density polyethylene (thickness 5 μm) The used sealant film was used. At this time, a linear low density polyethylene having a thickness of 20 μm is disposed on the adhesive layer 115 side.

  The packaging material 110 according to the third embodiment has the same layer configuration except for the packaging material 110 according to the first embodiment and the heat seal layer 116. The heat seal layer 116 of the packaging material 110 according to Example 3 is made of linear low density polyethylene (thickness 15 μm), cyclic olefin copolymer (thickness 5 μm), linear low density polyethylene and cyclic olefin copolymer. A sealant film in which a blend resin (thickness 10 μm) was laminated in order was used. At this time, a linear low density polyethylene having a thickness of 15 μm is disposed on the adhesive layer 115 side.

The packaging material 110 according to the fourth embodiment is formed in the same layer configuration as the packaging material 110 according to the first embodiment, and the characteristics of the adhesive layer 115 are different. The adhesive layer 115 is formed by coextrusion, and the upper layer portion 115a is formed of an ethylene methacrylic acid copolymer (AN42012C manufactured by Mitsui DuPont Chemical Co., Ltd.) having a thickness of 15 μm, an acid content of 9% and a melting point of 100 ° C. The lower layer portion 115 b of the adhesive layer 115 is formed of linear low density polyethylene (UJ370 manufactured by Prime Polymer Co., Ltd.) having a thickness of 15 μm, a density of 0.921 g / cm ^{3, and a} melting point of 121 ° C.

  The packaging material according to the fifth embodiment is formed in the same layer configuration as the packaging material 110 according to the second embodiment, and the characteristics of the heat seal layer 116 are different. The packaging material according to Example 5 includes a sealant film of heat seal layer 116, linear low density polyethylene (thickness 15 μm), cyclic olefin copolymer (thickness 5 μm), linear low density polyethylene (thickness 10 μm) The sealant film laminated | stacked in order of was used. At this time, a linear low density polyethylene having a thickness of 15 μm is disposed on the adhesive layer 115 side.

  The packaging material according to the sixth embodiment has the same layer configuration except for the packaging material 110 according to the first embodiment and the adhesive layer 115. The packaging material which concerns on Example 6 melt | dissolved ethylene methacrylic acid copolymer (Mitsui du Pont Chemical Co., Ltd. product AN42012C, 25 micrometers in thickness, acid content 9%, melting | fusing point) which melt | dissolved on one side of a polyethylene terephthalate film (12 micrometers in thickness). 100 ° C.) was adhered to bond the sealant film which is the heat seal layer 116.

Comparative Example 1
The packaging material according to Comparative Example 1 has the same layer configuration except for the packaging material 110 according to Example 1, the adhesive layer 115 and the heat seal layer 116. The packaging material which concerns on the comparative example 1 adhere | attached the sealant film which is the heat seal layer 116 through the adhesive agent for dry laminations to one side of the barrier layer 114 which consists of a polyethylene terephthalate film (12 micrometers in thickness). Here, for the sealant film, cyclic olefin copolymer (thickness 15 μm), linear low density polyethylene (thickness 25 μm), cyclic olefin copolymer (thickness 15 μm), linear low density polyethylene (thickness) The film laminated | stacked in order of 5 micrometers was used. At this time, a cyclic olefin copolymer having a thickness of 15 μm is disposed on the adhesive layer 115 side.

Comparative Example 2
The packaging material according to Comparative Example 2 has the same layer configuration except for the packaging material 110 according to Example 1, the adhesive layer 115 and the heat seal layer 116. The packaging material which concerns on the comparative example 2 adheres the sealant film which is the heat seal layer 116 through the adhesive agent for dry laminations which forms the contact bonding layer 115 in one side of the barrier layer 114 which consists of a polyethylene terephthalate film (12 micrometers in thickness). did. Here, a film of linear low density polyethylene having a thickness of 60 μm was used as the sealant film.

Comparative Example 3
The packaging material according to Comparative Example 3 has the same layer configuration except for the packaging material 110 according to Example 1, the adhesive layer 115 and the heat seal layer 116. The packaging material which concerns on the comparative example 3 extrude | melted the polyethylene (30 micrometers in thickness) which forms the contact bonding layer 115 on one surface of the barrier layer 114 which consists of a polyethylene terephthalate film (12 micrometers in thickness), and adhere | attached the sealant film. Here, as the sealant film which is the heat seal layer 116, a film made of linear low density polyethylene (thickness 30 μm) was used. In addition, an anchor coating agent was applied to the surface on the adhesive layer 115 side of the polyethylene terephthalate film.

Comparative Example 4
The packaging material according to Comparative Example 4 has the same layer configuration except for the packaging material 110 according to Example 1 and the adhesive layer 115. The packaging material according to Comparative Example 4 is a sealant which is a heat seal layer 116 by extruding molten polyethylene (30 μm in thickness) forming an adhesive layer 115 on one side of a barrier layer 114 made of polyethylene terephthalate film (12 μm in thickness). I adhered the film. In addition, an anchor coating agent was applied to the surface on the adhesive layer 115 side of the polyethylene terephthalate film.

Comparative Example 5
The packaging material according to Comparative Example 5 has the same layer configuration except for the packaging material 110 according to Example 1 and the adhesive layer 115. The packaging material according to Comparative Example 5 is a melted ethylene methacrylic acid copolymer (AN42012C, manufactured by Mitsui DuPont Chemical Co., Ltd.), which forms an adhesive layer 115 on one side of a barrier layer 114 made of polyethylene terephthalate film (12 μm thick). The sealant film which is the heat seal layer 116 was adhered by extruding a thickness of 20 μm, an acid content of 9%, and a melting point of 100 ° C.).

Comparative Example 6
The packaging material according to Comparative Example 6 has the same layer configuration except for the packaging material 110 according to Example 1 and the adhesive layer 115. The packaging material according to Comparative Example 6 is a melted ethylene-methacrylic acid copolymer (AN 4228 C, Mitsui DuPont Chemical Co., Ltd.), which forms an adhesive layer 115 on one side of a barrier layer 114 made of polyethylene terephthalate film (12 μm thick). The adhesive film which is the heat seal layer 116 was adhered by extruding a thickness of 20 μm and an acid content of 4%.

Comparative Example 7
The packaging material according to Comparative Example 7 has the same layer configuration except for the packaging material 110 according to Example 1 and the adhesive layer 115. The packaging material according to Comparative Example 7 is a molten linear low density polyethylene (manufactured by Prime Polymer Co., Ltd .; SP1071C) which forms the adhesive layer 115 on one side of the barrier layer 114 made of polyethylene terephthalate film (12 μm thick). 30 μm, density 0.91 g / cm ^3, melting point 100 ° C.) were extruded to bond the sealant film which is the heat seal layer 116.

Comparative Example 8
The packaging material according to Comparative Example 8 has the same layer configuration except for the packaging material 110 according to Example 1 and the adhesive layer 115. In the packaging material according to Example 8, the adhesive layer 115 was composed of ethylene methacrylic acid copolymer (Mitsui DuPont Chemical Co., Ltd., AN42012C thickness 15 μm, acid content 9%, melting point 100 ° C.) and low density polyethylene (LDPE) ( (Manufactured by Prime Co., Ltd.), LC602A 15 μm thick, density 0.919 g / cm ^3, melting point 107 ° C.), and co-extrusion.

[Evaluation of laminate strength]
Evaluation of laminate strength measures changes in laminate strength between the barrier layer 114 and the adhesive layer 115 and between the adhesive layer 115 and the heat seal layer 116 of the packaging materials according to Examples 1 to 6 and Comparative Examples 1 to 8 I did it. In addition, the change in laminate strength between the adhesive layer 115 and the heat seal layer 116 after immersion in the contents was also measured.

  A specific method heat-seals the end using the packaging materials according to Examples 1 to 6 and Comparative Examples 1 to 8, and creates a plurality of 15 cm × 25 cm packaging bags (heat seal width 10 mm), respectively. Hypochlorous acid was added and sealed. The packaging bag was stored for 12 weeks in a 40 ° C. environment.

  Next, hypochlorous acid is put in the inside and the packaging bag stored for 12 weeks and the packaging bag which does not put hypochlorous acid in the inside are cut at a width of 15 mm, and each cutting piece is tensile tester (Shimadzu Corporation (share The barrier layer 114 and the adhesive layer 115 were peeled off in the film flow direction of the packaging material at a speed of 50 mm / min using AGS-50D (trade name) manufactured by A.K. Similarly, the adhesive layer 115 and the heat seal layer 116 were peeled off in the film flow direction of the packaging material at a speed of 50 mm / min. This was carried out for each of 5 samples, and the average value was taken as the laminate strength (N / 15 mm). In addition, the packaging bag which put hypochlorous acid inside and was stored for 12 weeks measured only lamination strength of barrier layer 114 and adhesion layer 115. After the measurement, when the laminate strength was 2 N / 15 mm or more, it was judged that the laminate strength was excellent (◎). Moreover, when laminate strength was less than 2 N / 15 mm, it was judged that laminate strength was inferior (x). The results are shown in Table 2.

  As shown in Table 2, the packaging materials according to Examples 1 to 6 had high laminate strength between the adhesive layer 115 and the heat seal layer 116. In addition, the decrease in laminate strength was small even after storing hypochlorous acid inside and storing for 12 weeks.

  At this time, according to Examples 1 to 5, it was found that the barrier layer 114 and the heat seal layer 116 are bonded with high laminating strength by the adhesive layer 115 made of ethylene methacrylic acid copolymer and linear low density polyethylene. . Further, it was found from Example 6 and Comparative Example 6 that the barrier layer 114 and the heat seal layer 116 were bonded with high laminating strength by the adhesive layer 115 made of an ethylene methacrylic acid copolymer having a thickness of 25 μm or more. In addition, linear low density polyethylene and ethylene methacrylic acid copolymer are less likely to deteriorate even when containing hypochlorous acid as a content, and delamination is less likely to occur between the barrier layer 114 and the heat seal layer 116. I understood it.

[Evaluation of quality retention performance for contents]
The evaluation of the quality retention performance for the contents is as follows: after forming a 10 cm × 10 cm packaging bag (heat seal width 1 cm) with the packaging material 110 according to Examples 1 to 6 and Comparative Examples 1 to 8, 70 ° C. inside the packaging bag Changes in the taste of the contents were evaluated when the sake was filled and when distilled water was filled. When this was conducted by 10 investigators, respectively, and 9 or more out of 10 evaluated that the content did not have an odor caused by the adhesive or resin, it was judged that the quality retention performance to the content portion was excellent ()) . In addition, when six or more persons out of ten evaluated that the content did not have an odor caused by the adhesive or the resin, it was judged that the content had a certain quality retention performance with respect to the content (○). Moreover, when it was evaluated that the odor resulting from the adhesive or the resin was evaluated in the contents by 5 or less persons, it was judged that the quality retention performance to the contents portion was inferior (x). The results are shown in Table 3.

[Evaluation of non-adsorbable]
Evaluation of non-adsorbability was conducted by cutting the packaging materials according to Examples 1 to 6 and Comparative Examples 1 to 8 into 10 cm × 10 cm, and then sealing 100 g of menthol and the packaging material 110 cut in a glass container at 40 ° C. I kept it for one week. At this time, the mass change before and after storage of the packaging material was measured. In addition, when the mass change was less than +0.1 g, it was judged that the non-adsorbability was excellent (◎). Further, when the mass change was +0.1 g or more and +0.5 g or less, it was judged to have a certain non-adsorbability (o). Further, when the mass change was larger than +0.5 g, it was judged that the non-adsorbability was inferior (x). The results are shown in Table 3.

  As shown in Table 3, the packaging material 110 according to Examples 1 to 6 has high quality retention performance and non-adsorbability because the heat seal layer 116 contains a cyclic olefin copolymer by comparison with Comparative Examples 2 and 3. I understood it.

  Also, comparing Example 2 and Example 5, when the thickness of the layer made of linear low density polyethylene disposed in the innermost layer of the heat seal layer 116 is 5 μm, the quality retention performance is better than when it is 10 μm. taller than. Moreover, when Example 3 and Example 5 are compared, when the blend resin of a linear low density polyethylene with a thickness of 10 μm and a cyclic olefin copolymer is disposed in the innermost layer of the heat seal layer 116, the thickness is obtained. The quality retention performance is higher than in the case of arranging a layer consisting of linear low density polyethylene of 10 μm.

  This is considered to be because when the layer made of linear low density polyethylene is thickly formed, the odor component by the linear low density polyethylene penetrates into the contents. Therefore, the innermost layer of the heat seal layer 116 is a layer made of linear low density polyethylene having a thickness of 5 μm or less or a layer made of a blend resin of linear low density polyethylene having a thickness of 10 μm or less and a cyclic olefin copolymer Can improve the quality retention performance.

  In Examples 1 to 5, the melting point of the ethylene methacrylic acid copolymer forming the upper layer portion 115a of the adhesive layer 115 is 100 ° C. or less. The melting point of the linear low density polyethylene forming the lower layer portion 115b of Examples 1 to 3 and Example 5 is 100 ° C. or lower, and the melting point of the linear low density polyethylene forming the lower layer portion 115b of Example 4 is It is 121 ° C.

  For this reason, Examples 1 to 3 can melt-extrude the adhesive layer 115 at a lower temperature than Example 4, and the layer configurations of the thermal adhesive layer 115 and the heat seal layer 116 are the same as Example 1 and Example When compared with 4, the quality retention performance of Example 1 is higher. At this time, the density of the linear low density polyethylene forming the lower layer portion 115b of Example 1 is lower than that of Example 4.

Accordingly, if the melting point of the ethylene methacrylic acid copolymer and the linear low density polyethylene forming the adhesive layer 115 is 100 ° C. or less and the density of the linear low density polyethylene is less than 0.92 g / cm ³ , the quality retention Performance can be further improved.

  In addition, when the acid content of the ethylene methacrylic acid copolymer forming the upper layer portion 115a is 10% or more by mass percentage when the adhesive layer 115 is melt-extruded at a low temperature, the laminate strength of the adhesive layer 115 and the barrier layer 114 Decreases. Therefore, it is more preferable that the acid content of the ethylene methacrylic acid copolymer forming the upper layer portion 115a is less than 10% (4% in Example 1) by mass percentage.

  Similarly, in Example 6, the melting point of the ethylene methacrylic acid copolymer that forms the adhesive layer 115 is 100 ° C. or less, and has high quality retention performance. Therefore, it is more desirable that the melting point of the ethylene methacrylic acid copolymer forming the adhesive layer 115 be 100 ° C. or less, and the acid content be less than 10% by mass percentage.

  The present invention can be used as a packaging material for packaging a container containing a nonalcoholic beverage such as juice, tea, coffee, milk beverage, soup, etc., an alcoholic beverage such as sake or shochu, a menthol component and the like.

DESCRIPTION OF SYMBOLS 10 Packaging container 11a, 11b Heat seal part 110 Packaging material 112 Base material layer 113 Adhesive 114 Barrier layer 115 Adhesive layer 115a Upper layer part 115b Lower layer part 116 Heat seal layer 117 Thermal adhesive resin layer

Claims (2)

A packaging material in which at least a base material layer, a barrier layer having gas barrier properties, and a heat seal layer made of a heat adhesive resin are sequentially laminated, the heat seal layer including a layer made of a cyclic olefin copolymer, An adhesive layer for adhering the barrier layer and the heat seal layer comprises an ethylene methacrylic acid copolymer disposed on the barrier layer side and linear low density polyethylene disposed on the heat seal layer side, the adhesive layer Is formed by melt extrusion, and the heat seal layer comprises a sealant film .   The packaging material according to claim 1, wherein the heat seal layer has a layer made of the cyclic olefin copolymer or a layer made of linear low density polyethylene on the surface in contact with the adhesive layer.

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