JP4797472B2 - Laminate for liquid paper containers - Google Patents

Description

  The present invention is for a liquid paper container for making a liquid paper container that contains a content that is easily adsorbed by a sealant layer, which is a liquid contact layer of the container, or a content in which a container odor is easily transferred to the content. It relates to a laminated material.

  Conventionally, liquid paper containers have been used in large quantities over a wide range of applications as containers for liquid foods of the normal temperature distribution type that require long-term storage such as alcoholic beverages and fruit juice drinks. As these liquid paper containers, there are a container having a gable roof shape at the top and a quadrangular prism shape at the trunk, and a brick-shaped container. Since the liquid paper container laminates that make these liquid paper containers require appropriate and appropriate rigidity and barrier properties, the paper layer is the main layer, plastic film layer, aluminum foil layer, vapor deposition The laminated material for liquid paper containers which laminates a film layer etc. was used. This laminated material for a liquid paper container is composed of an outermost layer that is the outside of the container, an intermediate layer that is a main layer of the paper layer, and an innermost sealant (heat seal material) layer that is in contact with the liquid. As the sealant layer, for example, a polyethylene layer having a thickness of 60 μm is generally used. Further, in the case of a content in which the contained component is easily adsorbed to the sealant layer, for example, a polyester layer having a thickness of 60 μm has been used.

However, the conventional laminate for liquid paper containers described above has good heat sealability and good sealing performance as a container when a polyethylene layer having a thickness of 60 μm is used as the sealant layer. The polyethylene component of molecular weight elutes in the contents, and the polyethylene odor shifts to the contents. Conversely, the active ingredient contained in the contents is, for example, limonene (C ₁₀ H ₁₆ which is an aroma component of juice). ) Or the like may be adsorbed by the sealant layer, which may change the taste or scent of the contents. In addition, when a 60 μm thick polyester layer is used for the sealant layer, the taste and fragrance change of the contents are small. For example, the heat sealability on the filling machine is inferior, and the sealing performance as a container leaks. There was a problem. This is because heating and pressurization are separate sections in the bag making process of the filling machine, and the polyester layer with a high crystallization speed has reduced fluidity during pressurization and heat sealability. It is. In addition, when the adhesive resin layer is provided on the polyester layer of the intermediate layer and the polyethylene layer of the sealant layer is adhered to the polyester layer of the intermediate layer by three-layer coextrusion, the taste and flavor of the contents are reduced by the low molecular weight component resulting from the adhesive resin layer. May be damaged.

  The present invention solves the problems in the above-mentioned conventional laminated materials for liquid paper containers, has good heat sealability on the filling machine, and impairs the taste, flavor, fragrance, etc. of the contents. The present invention provides a laminated material for a liquid paper container that does not have any.

That is, the first invention of the present invention is a laminate for a liquid paper container comprising an outer layer, a laminated intermediate layer mainly comprising a paper layer, and an inner sealant layer ,
The outer layer is a polyethylene layer, the sealant layer is a laminated structure, the intermediate layer side layer is a polyester layer, the liquid contact side layer is a polyethylene layer, and a blend of polyester and polyethylene between the intermediate layer side layer and the liquid contact side layer Layers are provided ,
The blend layer is a laminate for a liquid paper container characterized in that the blend layer has a laminated structure of two or more layers, and the blend ratio of polyester to polyethylene is increased as the layer is closer to the intermediate layer side layer .

Next, according to a second aspect of the present invention, the sealant layer is coextruded to form a film by lamination, and the polyester layer and the polyethylene layer are bonded with a blend layer of polyester and polyethylene. It is a laminated material for liquid paper containers as described .

Next, according to a third aspect of the present invention, there is provided the laminated material for a liquid paper container according to any one of claims 1 and 2, wherein the polyethylene layer of the liquid contact side layer has a thickness of 50 µm or less. is there.

  Since the outermost layer is a polyethylene layer and the liquid contact side layer of the laminated sealant layer, that is, the innermost layer is a polyethylene layer, the laminated material for a liquid paper container of the present invention has heat sealability in the bag making process on the filling machine. The container produced using the laminated material for a liquid paper container of the present invention has good sealing properties.

  Further, the laminate for a liquid paper container of the present invention has a sealant layer laminated structure, an intermediate layer side layer is a polyester layer, a liquid contact side layer is a polyethylene layer having a thickness of 50 μm or less, and an intermediate layer side layer polyester layer The polyester layer and the polyethylene layer on the liquid contact side are bonded to each other by coextrusion lamination with a single layer or multiple layers of polyester and polyethylene blended, and no adhesive or adhesive resin is used for bonding. In addition, the migration of the low molecular weight component from the laminated material to the content is extremely small, and the adsorption of the active component of the content of the sealant layer is extremely small, so that the taste, flavor, aroma and the like of the content are not impaired.

  Next, an embodiment of the laminate for a liquid paper container of the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1 (a), the laminated material (100) for a liquid paper container according to this embodiment includes a heat-sealable outer layer (110), and an intermediate layer (120) having a laminated structure mainly composed of paper layers. The laminated material is composed of a sealant layer (130) having a good heat sealability of the inner layer. The outer layer is a polyethylene layer, and the intermediate layer is mainly a paper layer. Various types of lamination processing methods such as various synthetic resin layers, plastic film layers, aluminum foil layers, and vapor deposition film layers are used according to the intended use of the container. Is used to laminate. As shown in FIG. 1B, the sealant layer has a laminated structure, the intermediate layer side is a polyester layer (131), the liquid contact side is a polyethylene layer (132), and the intermediate layer side is in contact with the polyester layer. A polyester-polyethylene blend layer (133) is coextruded between the liquid-side polyethylene layer and formed into a film by lamination, and the polyester layer and the polyethylene layer are bonded together. The blend layer is not limited to a single layer, and can have a laminated structure of two or more layers as necessary. In this case, the layer closer to the intermediate layer side increases the blend ratio of polyester to polyethylene. The blend ratio of polyethylene and polyester can be set within a range of 9/1 to 1/9 of polyethylene / polyester. The thickness of the polyester layer can be set in the range of 5 to 50 μm, the thickness of the blend layer can be set in the range of 5 to 50 μm, and the thickness of the polyethylene layer can be set in the range of 5 to 50 μm. It is.

  Specific examples of the present invention will be described below.

<Example>
First, a polyethylene layer (20 μm thickness) / paper layer (basis weight 400 g / m ² ) / ethylene / methacrylic acid copolymer layer (25 μm thickness) / aluminum foil layer (7 μm thickness) / adhesive by laminating method Layer (3 g / m ² ) / polyethylene terephthalate film layer (12 μm thick) laminated material is prepared, and then an adhesive layer is provided on the polyethylene terephthalate film layer side of the laminated material to form a polyester layer, polyethylene and Polyester blend layer and polyethylene layer were laminated by co-extrusion lamination, and as shown in FIG. 2, [outside of container] polyethylene layer (111) (20 μm thickness) / paper layer (121) (basis weight 400 g / m ² ) / Ethylene / methacrylic acid copolymer layer (122) (25 μm thickness) / Aluminum foil layer (123) (7 μm thickness) / Adhesive (125) / polyethylene terephthalate film layer (124) / adhesive layer (126) / polyester layer (131) (20 μm thickness) / polyethylene and polyester blend layer (133) (20 μm thickness) / polyethylene layer (132) (20 μm) A laminate (100) for a liquid paper container of an example having a thickness (inner side) configuration was produced. The coating amount of the adhesive of the adhesive layer is 3 g / m ^2, the blend ratio of the blend layer was polyethylene / polyester = 1/1.

  Next, a comparative example of the present invention will be described.

<Comparative Example 1>
By the laminating method, as shown in FIG. 3, the [outside of the container] polyethylene layer (111) (20 μm thickness) / paper layer (121) (basis weight 400 g / m) / ethylene / methacrylic acid copolymer layer (122 ) (25 μm thickness) / aluminum foil layer (123) (7 μm thickness) / adhesive layer (125) / polyethylene terephthalate film layer (124) / adhesive layer (126) / polyethylene layer (136) (60 μm thickness) [ Container Laminate] A laminate (100) for a liquid paper container of Comparative Example 1 having the configuration was prepared. In addition, the application quantity of the adhesive agent of an adhesive bond layer was 3 g / m < ² >.

<Comparative example 2>
By the laminating method, as shown in FIG. 4, [outside of the container] polyethylene layer (111) (20 μm thickness) / paper layer (121) (basis weight 400 g / m) / ethylene / methacrylic acid copolymer layer (122 ) (25 μm thickness) / aluminum foil layer (123) (7 μm thickness) / adhesive layer (125) / polyethylene terephthalate film layer (124) / adhesive layer (126) / polyester layer (137) (60 μm thickness) [ Container Laminate (100) for a liquid paper container of Comparative Example 2 having the configuration was prepared. In addition, the application quantity of the adhesive agent of an adhesive bond layer was 3 g / m < ² >.

<Evaluation>
The three types of laminates for liquid paper containers of Examples, Comparative Example 1 and Comparative Example 2 described above were comparatively evaluated for filling machine suitability, adsorptivity, elution of low molecular weight components, and taste change. The evaluation method is as follows. As for the suitability of the filling machine, the laminated materials for liquid paper containers of each configuration were boxed with a filling machine, filled with a liquid leak check solution and sealed, and the liquid leak state was examined. Evaluation is the number of liquid leaks / total number of samples. As for the adsorptivity, a pouch of 100 mm × 100 mm was prepared with a laminated material for liquid paper containers of each configuration, 100 ml of limonene was sealed, and stored at 40 ° C. for 1 week, and then the weight change amount of the pouch itself was measured. . Evaluation was represented by the ratio when the comparative example 1 was set to 1.0. For elution of low molecular weight components, a 150 mm x 150 mm three-sided seal pouch was prepared with a laminated material for liquid paper containers of each constitution, filled with distilled water and sealed, stored at 60 ° C for 24 hours, then returned to room temperature, The low molecular weight component was quantified by GC-MS evaluation. Evaluation was represented by the ratio when the comparative example 1 was set to 1.0. For taste changes, a 150 mm x 150 mm three-sided seal pouch is prepared with a liquid paper container laminate of each configuration, sealed with distilled water, stored at 60 ° C for 24 hours, and then returned to room temperature for sensory evaluation. Went. The number of panelists was 10. Table 1 shows the results of the comparative evaluation.

表１に示すように、充填機適性については、比較例１と実施例の積層材は、充填機で製箱した容器に液漏れを発生したものがなかったが、比較例２の積層材は、充填機で製箱した容器のほぼ半数箇に液漏れが発生し、充填機適性に問題があった。吸着性については、リモネンの積層材の吸着量が、比較例１の積層材と比較して、比較例２の積層材は少なく、更に実施例の積層材は比較例２の積層材よりも少なかった。低分子量成分溶出については、比較例１の積層材と比較して、比較例２の積層材は少なく、更に実施例の積層材は比較例２の積層材よりも少なかった。味覚変化については、１０名のパネラーの官能評価では、比較例１の積層材は不要で、実施例及び比較例２の積層材は良好であった。上述の評価結果から総合評価してみると、実施例の積層材は良好であり、比較例１及び比較例２の積層材は不良であった。

As shown in Table 1, regarding the suitability of the filling machine, the laminated materials of Comparative Example 1 and Example did not cause any liquid leakage in the containers made by the filling machine, but the laminated material of Comparative Example 2 was Liquid leakage occurred in almost half of the containers made with the filling machine, and there was a problem in suitability of the filling machine. Regarding the adsorptivity, the amount of adsorption of the laminate of limonene is less than that of the laminate of Comparative Example 1, and the laminate of Comparative Example 2 is less than that of Comparative Example 2. It was. Regarding the elution of low molecular weight components, the laminate material of Comparative Example 2 was less than the laminate material of Comparative Example 1, and the laminate materials of Examples were less than the laminate material of Comparative Example 2. Regarding the taste change, in the sensory evaluation of 10 panelists, the laminated material of Comparative Example 1 was unnecessary, and the laminated materials of Examples and Comparative Example 2 were good. When comprehensive evaluation was performed from the above evaluation results, the laminated materials of the examples were good, and the laminated materials of Comparative Example 1 and Comparative Example 2 were poor.

(A) is explanatory drawing which shows the structure of the laminated material for liquid paper containers of this invention, (b) is explanatory drawing which shows a structure of an example of a sealant layer, (c) is other than a sealant layer. It is explanatory drawing which shows the structure of an example. It is explanatory drawing which shows the structure of the laminated material for liquid paper containers of an Example. It is explanatory drawing which shows the structure of the laminated material for liquid paper containers of the comparative example 1. 6 is an explanatory view showing a configuration of a laminated material for a liquid paper container of Comparative Example 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Laminate material 110 for liquid paper containers ... Outer layer 111,132,136 ... Polyethylene layer 120 ... Intermediate layer 121 ... Paper layer 122 ... Ethylene-methacrylic acid copolymer layer 123 ... Aluminum foil Layer 124 ... Polyethylene terephthalate film layer 125, 126 ... Adhesive layer 130 ... Sealant layer 131, 137 ... Polyester layer 133, 134, 135 ... Blend layer

Claims (3)

A laminate for a liquid paper container comprising an outer layer, a laminated intermediate layer mainly comprising a paper layer, and an inner sealant layer ,
The outer layer is a polyethylene layer, the sealant layer is a laminated structure, the intermediate layer side layer is a polyester layer, the liquid contact side layer is a polyethylene layer, and a blend of polyester and polyethylene between the intermediate layer side layer and the liquid contact side layer Layers are provided ,
A laminate for a liquid paper container, wherein the blend layer has a laminate structure of two or more layers, and the blend ratio of polyester to polyethylene is increased in a layer closer to the intermediate layer side layer. The laminate for a liquid paper container according to claim 1, wherein the sealant layer is formed by coextrusion lamination, and the polyester layer and the polyethylene layer are bonded together with a blend layer of polyester and polyethylene. The laminated material for a liquid paper container according to any one of claims 1 to 2, wherein the thickness of the polyethylene layer of the liquid contact side layer is 50 µm or less.

Images