JP2017154277A - Multilayer sheet, tray and package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer sheet that has excellent water vapor and oxygen barrier properties and excellent sealability, and prevents dust deposition on its surface.SOLUTION: A multilayer sheet 1 has a water steam barrier layer 4, an oxygen barrier layer 2, and surface layers 5,6. The surface layers 5,6 are put on the outermost surface layers on both sides of the multilayer sheet. An amount of triboelectrification between at least one surface layer 5(6) and a polypropylene resin pellet is 0.5 nC or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a multilayer sheet, a tray, and a package.

  Conventionally, paper, synthetic resin sheets or films, vapor-deposited films, laminates with synthetic resin films, aluminum packaging, and the like have been used as packaging materials for pharmaceuticals, medical products, foods, beverages, and the like. When used in the above applications, it is necessary to protect the contents, in particular, to have a barrier property against water vapor and oxygen. To protect the contents over the long term, a high barrier property is required. ing.

  Examples of the material satisfying both the water vapor barrier property and the oxygen barrier property include vapor deposition films and aluminum packaging. However, these can be used as a specific packaging body such as a pouch shape, but it is difficult to form them into an arbitrary shape with a molding machine or the like, and their usage is limited.

  On the other hand, as a form of the packaging container, a packaging form in which a film and an aluminum foil are heat-sealed as a lid material after being molded into a container using a synthetic resin sheet as a bottom material is often used. A polyolefin resin excellent in moldability, productivity, chemical resistance, and water vapor barrier properties is particularly used as a synthetic resin sheet as a bottom material.

  However, polyolefin-based resins are excellent in water vapor barrier properties but inferior in oxygen barrier properties. For this reason, the contents may have various problems such as oxidation, deterioration, rot, or generation of rust.

  In order to solve the above problem, for example, Patent Document 1 includes a layer containing a resin having excellent oxygen barrier properties such as an ethylene-vinyl alcohol copolymer and nylon, and a resin having excellent water vapor barrier properties such as polyolefins. A resin laminate including a layer to be disclosed is disclosed.

Japanese Patent Publication No. 06-015227

  However, the resin laminate disclosed in Patent Document 1 has a problem that water vapor, oxygen barrier properties and sealing properties are not sufficient. Furthermore, there is a problem that dust is not easily attached to the surface and is not hygienic.

  This invention is made | formed in view of the said situation, Comprising: It aims at providing the multilayer sheet which is excellent in water vapor | steam, oxygen barrier property, and sealing performance, and is hard to adhere dust on the surface.

  Another object of the present invention is to provide a tray and a package that are excellent in water vapor, oxygen barrier properties, and sealing properties, and that do not easily adhere dust to the inner surface or contents when opened.

In order to achieve the above object, the present invention employs the following configuration.
That is, the invention according to claim 1 of the present application is a multilayer sheet having a water vapor barrier layer, an oxygen barrier layer, and a surface layer, wherein the surface layer is laminated on the outermost layers on both sides, A multilayer sheet in which the triboelectric charge amount between the surface layer and the polypropylene resin pellet is 0.5 nC or less.

  The invention according to claim 2 is the multilayer sheet according to claim 1, wherein at least one surface layer and the water vapor barrier layer are laminated adjacent to each other.

  The invention according to claim 3 is characterized in that the surface layer is at least one resin selected from the group consisting of polypropylene, polyethylene, high-density polyethylene, cyclic olefin polymer, cyclic olefin copolymer, polyvinyl chloride, polyvinylidene chloride, and polychlorotrifluoroethylene. It is a multilayer sheet of Claim 1 or 2 containing these.

  The invention according to claim 4 is the multilayer sheet according to claim 3, wherein the water vapor barrier layer includes a resin that is the same as or different from the resin contained in the surface layer, and an inorganic filler.

  The invention according to claim 5 is the multilayer sheet according to claim 4, wherein the inorganic filler contains at least one of layered silicates, titanium oxide, and calcium carbonate.

  The invention according to claim 6 is the multilayer sheet according to claim 5, wherein the layered silicates include at least one of talc, mica, montmorillonite, kaolin, bentonite, and hectorite.

  The invention according to claim 7 is the multilayer sheet according to any one of claims 1 to 6, wherein the thickness of the multilayer sheet is 500 μm or more and 1500 μm or less.

In the invention according to claim 8, the water vapor transmission rate under the conditions of 40 ° C. and 90% RH is 0.3 g / m ² · day or less,
The multilayer sheet according to any one of claims 1 to 7, wherein an oxygen transmission amount under conditions of 25 ° C and 60% RH is 0.35 cc / m ² · day or less.

  The invention according to claim 9 is a tray formed with the multilayer sheet according to claim 1.

  Moreover, the invention which concerns on Claim 10 is a package provided with the tray of Claim 9, and a cover material.

  The multilayer sheet of the present invention has a water vapor barrier layer, an oxygen barrier layer, and a surface layer, the surface layer is laminated on the outermost layer on both sides, and the triboelectric charge amount between at least one surface layer and the polypropylene resin pellet is Since it is 0.5 nC or less, it is excellent in water vapor | steam, oxygen barrier property, and sealing performance, and dust does not adhere to the surface easily.

  In addition, since the tray of the present invention is obtained by secondary molding of the multilayer sheet, it is excellent in water vapor, oxygen barrier properties and sealing properties, and is hygienic as it prevents dust from adhering to the inner surface or contents when opened. .

  Moreover, since the package of this invention is equipped with the said tray and a lid | cover material, while being excellent in water vapor | steam, oxygen barrier property, and sealing performance, it is hygienic not to adhere dust to the inner surface or the content at the time of opening.

It is sectional drawing which shows the structure of the multilayer sheet which is one Embodiment to which this invention is applied. It is sectional drawing which shows the structure of the package which is one Embodiment to which this invention is applied.

  Hereinafter, a multilayer sheet which is an embodiment to which the present invention is applied, a tray obtained by secondary molding of the multilayer sheet, and a package including the tray will be described in detail. In addition, in the drawings used in the following description, in order to make the features easy to understand, there are cases where the portions that become the features are enlarged for the sake of convenience, and the dimensional ratios of the respective components are not always the same as the actual ones. Absent.

<Multilayer sheet>
First, an example of the structure of the multilayer sheet which is one embodiment to which the present invention is applied will be described.
FIG. 1 is a schematic cross-sectional view of a multilayer sheet 1 according to an embodiment to which the present invention is applied. As shown in FIG. 1, the multilayer sheet 1 of the present embodiment is schematically configured to include an oxygen barrier layer 2, an adhesive layer 3, a water vapor barrier layer 4, and surface layers 5 and 6.
The multilayer sheet 1 of the present embodiment can be used for packaging materials such as pharmaceuticals, preparations, infusion preparations, blood preparations, medical devices, cosmetics, quasi-drugs, foods, beverages, industrial members, and electronic parts. it can.

  The oxygen barrier layer 2 is a resin layer that suppresses permeation of oxygen and water vapor, and is provided to give the multilayer sheet 1 oxygen barrier properties and water vapor barrier properties. Further, when the multilayer sheet 1 is formed into a package, it is possible to suppress the permeation of oxygen and water vapor into the package.

  Specific examples of the resin contained in the oxygen barrier layer 2 include ethylene-vinyl alcohol copolymer, polyamide, polyvinyl alcohol, polyacrylonitrile, and polyvinylidene chloride. Among these, ethylene-vinyl alcohol copolymer and polyamide are particularly preferable from the viewpoint of film forming property with the water vapor barrier layer 4. The oxygen barrier layer 2 may include one type of the above resin, or may include two or more types. Further, an oxygen absorbing material may be used as the oxygen barrier layer 2.

  The oxygen barrier layer 2 may contain an inorganic filler in addition to the resin. Specific examples of the inorganic filler include layered silicates such as talc, mica, kaolin, clay, bentonite, silica, calcium carbonate, magnesium carbonate, calcium sulfate, magnesium sulfate, barium sulfate, glass filler, and glass. Examples thereof include fibers, glass beads, titanium oxide, aluminum oxide, iron, zinc, and aluminum. The inorganic filler contained in the oxygen barrier layer 2 is preferably a plate-like or scaly filler having a large aspect ratio from the viewpoint of improving the barrier property, and among the inorganic fillers, talc and mica are more preferred.

  Further, the content of the inorganic filler in the oxygen barrier layer 2 is specifically preferably 10% by mass or more and 40% by mass or less with respect to the mass of the entire oxygen barrier layer 2, for example. More preferably, it is 20 mass% or more and 30 mass% or less. When the content of the inorganic filler in the oxygen barrier layer 2 is 10% by mass or more with respect to the mass of the oxygen barrier layer 2 as a whole, the water vapor barrier property of the oxygen barrier layer 2 is improved, and the entire multilayer sheet 1 As a result, the water vapor barrier property can be dramatically improved. Moreover, when the content rate of the inorganic filler in the oxygen barrier layer 2 is 40% by mass or less with respect to the mass of the oxygen barrier layer 2 as a whole, the film formability of the sheet and the formability of the package deteriorate. Can be prevented.

  The thickness of the oxygen barrier layer 2 is not particularly limited, but specifically, for example, it is preferably 12.5 μm or more and 300 μm or less, and more preferably 25 μm or more and 200 μm or less. When the thickness of the oxygen barrier layer 2 is 12.5 μm or more, the oxygen barrier property and the water vapor barrier property can be sufficiently exhibited. Moreover, when the thickness of the oxygen barrier layer 2 is 300 μm or less, the oxygen barrier layer 2 can be easily molded at the time of container molding, and the elongation as a sheet can be maintained. Furthermore, the said effect can be exhibited more notably because the said thickness is 25 micrometers or more and 200 micrometers or less.

  The thickness ratio of the oxygen barrier layer 2 is not particularly limited, but specifically, for example, it is preferably 2.5% or more and 20% or less with respect to the total thickness of the multilayer sheet 1. % Or more and 15% or less is more preferable. When the ratio of the thickness of the oxygen barrier layer 2 is 2.5% or more with respect to the total thickness of the multilayer sheet 1, oxygen barrier properties and water vapor barrier properties can be sufficiently exhibited. Moreover, when the ratio of the thickness of the oxygen barrier layer 2 is 20% or less with respect to the total thickness of the multilayer sheet 1, the ratio of the thickness of the water vapor barrier layer 4 can be maintained, and the water vapor barrier property can be maintained. And oxygen barrier property can fully be expressed. Furthermore, the said effect can be acquired more notably because the said ratio is 5% or more and 15% or less.

  One adhesive layer 3 is provided between the oxygen barrier layer 2 and the water vapor barrier layer 4 in order to bond the oxygen barrier layer 2 and the water vapor barrier layer 4. By laminating the oxygen barrier layer 2, the adhesive layer 3 and the water vapor barrier layer 4 in this order, the oxygen barrier layer 2 and the water vapor barrier layer 4 can be bonded via the adhesive layer 3.

  The material of the adhesive layer 3 is not particularly limited as long as it can adhere the oxygen barrier layer 2 and the water vapor barrier layer 4. Specifically, for example, an adhesive resin such as maleic anhydride-modified olefin, a resin in which a resin contained in the oxygen barrier layer 2 or the water vapor barrier layer 4 is mixed, and the like can be given.

  The water vapor barrier layer 4 is a resin layer that suppresses the permeation of water vapor, and is provided for imparting water vapor barrier properties to the multilayer sheet 1. One water vapor barrier layer 4 is laminated on each side of the surface of the oxygen barrier layer 2 with an adhesive layer 3 interposed therebetween. Thereby, when the multilayer sheet 1 of this embodiment is shape | molded in the package body, while protecting the contents, permeation | transmission of the water vapor | steam into a package body can be suppressed. As a result, it is possible to suppress a decrease in oxygen barrier properties due to moisture absorption of the oxygen barrier layer 2. Furthermore, since the intermolecular hydrogen bond of the resin constituting the oxygen barrier layer 2 is prevented from being broken by water vapor, and the molecular gap of the resin constituting the oxygen barrier layer 2 can be maintained in a narrow state, the oxygen barrier layer 2 has a water vapor barrier property. Can be expressed.

  Specific examples of the resin contained in the water vapor barrier layer 4 include, for example, polyolefin resins such as polypropylene, polyethylene, high density polyethylene, cyclic olefin polymer, and cyclic olefin copolymer, petroleum resins, polyvinyl chloride, polyvinylidene chloride, Examples thereof include resins containing halogen atoms such as polychlorotrifluoroethylene. Among these, polypropylene, polyethylene, and high-density polyethylene are preferable from the viewpoints of moldability to the multilayer sheet 1, moldability to a package, sealability with a lid, and cost. The water vapor barrier layer 4 may include one type of the above resin, or may include two or more types.

  The water vapor barrier layer 4 preferably contains an inorganic filler in addition to the resin. Specific examples of the inorganic filler include layered silicates such as talc, mica, montmorillonite, kaolin, clay, bentonite, hectorite, silica, calcium carbonate, magnesium carbonate, calcium sulfate, magnesium sulfate, and barium sulfate. , Glass filler, glass fiber, glass bead, titanium oxide, aluminum oxide, iron, zinc, aluminum and the like. The water vapor barrier layer 4 may include one kind of the inorganic filler or may include two or more kinds. The inorganic filler contained in the oxygen barrier layer 2 is preferably a plate-like or scaly filler having a large aspect ratio from the viewpoint of improving the barrier property, and among the inorganic fillers, talc and mica are more preferred.

  In addition, as the content of the inorganic filler in the water vapor barrier layer 4, specifically, for example, it is preferably 10% by mass or more and 40% by mass or less with respect to the total mass of the water vapor barrier layer 4, More preferably, it is 20 mass% or more and 30 mass% or less. When the content of the inorganic filler in the water vapor barrier layer 4 is 10% by mass or more with respect to the mass of the water vapor barrier layer 4 as a whole, the water vapor barrier property of the water vapor barrier layer 4 is improved, and the multilayer sheet 1 as a whole As a result, the water vapor barrier property can be dramatically improved. Moreover, when the content rate of the inorganic filler in the water vapor barrier layer 4 is 40% by mass or less with respect to the mass of the water vapor barrier layer 4 as a whole, the film formability of the multilayer sheet 1 and the moldability to the package are achieved. Can be prevented from getting worse.

  The thickness of one layer of the water vapor barrier layer 4 is not particularly limited, but specifically, for example, it is preferably 200 μm or more and 650 μm or less, and more preferably 300 μm or more and 500 μm or less. When the thickness of one layer of the water vapor barrier layer 4 is 200 μm or more, the water vapor barrier property can be sufficiently exhibited. Moreover, when the thickness of one layer of the water vapor barrier layer 4 is 650 μm or less, the multilayer sheet 1 can be easily formed into a package. Furthermore, the said effect will be more notably acquired if the said thickness is 300 micrometers or more and 500 micrometers or less.

  The ratio of the total thickness of the two layers of the water vapor barrier layer 4 is not particularly limited. Specifically, for example, the total thickness of the multilayer sheet 1 is 37.5% or more and 90% or less. Preferably, it is 45% or more and 85% or less. When the ratio of the total thickness of the two layers of the water vapor barrier layer 4 is 37.5% or more with respect to the total thickness of the multilayer sheet 1, the water vapor barrier property can be sufficiently exhibited as the whole sheet. Further, when the ratio of the total thickness of the two layers of the water vapor barrier layer 4 is 90% or less with respect to the total thickness of the multilayer sheet 1, it is possible to ensure a sufficient oxygen barrier property in addition to the water vapor barrier property. it can. Furthermore, if the said ratio is 45% or more and 85% or less, the said effect will be acquired more notably.

Specifically, the water vapor transmission amount of the water vapor barrier layer 4 is preferably 0.8 g / m ² · day or less, for example, in an atmosphere of 40 ° C. and 90% RH, and is preferably 0.75 g / m ² · day or less. Is more preferable, and 0.7 g / m ² · day or less is particularly preferable. When the water vapor transmission amount of the water vapor barrier layer 4 is 0.8 g / m ² · day or less in an atmosphere of 40 ° C. and 90% RH, the water vapor transmission amount to the oxygen barrier layer 2 is reduced, and the oxygen barrier A decrease in oxygen barrier property due to moisture absorption of the layer 2 is suppressed, and the oxygen barrier layer 2 can sufficiently exhibit the water vapor barrier property. Further, when the water vapor transmission amount is 0.75 g / m ² · day or less and 0.7 g / m ² · day or less, the above effect can be obtained more remarkably.

  In addition, the water vapor transmission rate of the water vapor barrier layer 4 is measured by a method described in the JIS K 7129B method using a water vapor transmission rate measuring device (for example, “PERMATRAN-W MODEL 3/33” manufactured by MOCON). Can be done in compliance.

  The surface layers 5 and 6 are provided so as to be the outermost layers on both sides of the multilayer sheet 1 in order to impart sealing properties and glossiness to the multilayer sheet 1. That is, the surface layers 5 and 6 are laminated so as to be adjacent to the water vapor barrier layer 4. Here, when the multilayer sheet 1 is formed into a tray, for example, when the surface layer 5 is provided on the inner side (inner surface), the surface layer 5 exhibits a function of imparting a sealing property. It is possible to improve sealability while suppressing variations in seal strength. On the other hand, the surface layer 6 serving as the outer side (outer surface) imparts gloss, so that the gloss of the tray can be improved and an excellent appearance can be imparted.

  The resin contained in the surface layer (hereinafter also referred to as “inner surface layer”) 5 serving as the inner surface is a resin that can adhere to the water vapor barrier layer 4 or a lid material (when formed into a tray). If there is, it will not be specifically limited. Specific examples include polyolefin resins such as polypropylene and polyethylene, cyclic polyolefin resins, polyester resins, and halogen resins. The surface layer 5 may include one type of the above resin, or may include two or more types. By selecting the resin, when the multilayer sheet 1 is formed into a tray, a sufficient sealing strength between the tray and the lid material can be secured.

  Moreover, it is preferable that the surface layer 5 used as an inner surface does not contain an inorganic filler. That is, the surface layer 5 is preferably a layer made only of a resin.

  By the way, it is preferable that the water vapor | steam barrier layer 4 contains an inorganic filler as mentioned above. However, when the resin layer containing the inorganic filler is used as the outermost layer of the multilayer sheet 1, the variation in the sealing strength between the tray on which the multilayer sheet 1 is molded and the lid material increases, and sufficient sealing performance cannot be obtained. There is a fear. On the other hand, by using the surface layer 5 that does not contain an inorganic filler as the outermost layer of the multilayer sheet 1, it is possible to suppress variations in seal strength and improve the sealing performance.

  Further, since the surface layer 5 serving as the inner surface does not contain an inorganic filler, when the multilayer sheet 1 is bonded to the die lip when the multilayer sheet 1 is manufactured, the productivity is increased due to adhesion of the inorganic filler or the like to the die lip. It is possible to prevent the decrease.

  The resin contained in the surface layer 5 (or the surface layer 6) may be the same as or different from the resin contained in the water vapor barrier layer 4 described above.

  On the other hand, as the resin contained in the surface layer 6 (hereinafter also referred to as “outer surface layer”) serving as the outer surface, the same resin as the surface layer 5 can be used. Further, like the surface layer 5, the surface layer 6 preferably does not contain an inorganic filler.

  By the way, it is preferable that the water vapor | steam barrier layer 4 contains an inorganic filler as mentioned above. However, when the resin layer containing the inorganic filler is the outermost layer of the multilayer sheet 1, the glossiness of the multilayer sheet 1 may be lost. On the other hand, the glossiness of the multilayer sheet 1 can be sufficiently secured by using the surface layer 6 that does not contain an inorganic filler as the outermost layer of the multilayer sheet 1.

  Although it does not specifically limit as thickness of the surface layers 5 and 6, Specifically, it is preferable that they are 12.5 micrometers or more and 280 micrometers or less, for example, and it is more preferable that they are 25 micrometers or more and 200 micrometers or less. If the thickness of the surface layers 5 and 6 is 12.5 μm or more, stabilization of the sealing strength and glossiness can be sufficiently expressed. Moreover, if the thickness of the surface layers 5 and 6 is 280 micrometers or less, water vapor | steam barrier property can fully be expressed. Furthermore, the said effect will be more notably acquired if the said thickness is 25 micrometers or more and 200 micrometers or less.

  The ratio of the combined thickness of the surface layers 5 and 6 is not particularly limited, but specifically, for example, it is preferably 2.5% or more and 56% or less with respect to the total thickness of the multilayer sheet 1. More preferably, it is 5% or more and 40% or less. If the ratio of the combined thickness of the surface layers 5 and 6 is 2.5% or more with respect to the total thickness of the multilayer sheet 1, the seal strength can be stabilized and the glossiness can be sufficiently exhibited. Moreover, if the said ratio is 56% or less with respect to the total thickness of the multilayer sheet 1, sufficient water vapor | steam barrier property can be ensured. Furthermore, if the said ratio is 5% or more and 40% or less, the said effect will be acquired more notably.

  Although it does not specifically limit as total thickness of the multilayer sheet 1 of this embodiment, Specifically, it is preferable that they are 500 micrometers or more and 1500 micrometers or less, for example, and it is more preferable that they are 800 micrometers or more and 1350 micrometers or less. If the total thickness of the multilayer sheet 1 is 500 μm or more, both the water vapor barrier property and the oxygen barrier property can be sufficiently exhibited. Moreover, if the total thickness of the multilayer sheet 1 is 1500 micrometers or less, the shaping | molding cycle to a container shape can be shortened. Further, when the total thickness is 800 μm or more and 1350 μm or less, the above effect can be obtained more remarkably.

Specifically, the water vapor barrier property of the multilayer sheet 1 of the present embodiment is preferably, for example, a water vapor transmission rate of 0.3 g / m ² · day or less in an atmosphere of 40 ° C. and 90% RH. , 0.25 g / m ² · day or less is more preferable, and 0.2 g / m ² · day or less is particularly preferable.

When the multilayer sheet 1 is molded into a package by the amount of water vapor permeation in the atmosphere of 40 ° C. and 90% RH of the multilayer sheet 1 being 0.3 g / m ² · day or less, the contents are external moisture. It is possible to sufficiently protect the water content, and it is possible to preserve the contents that are vulnerable to moisture for a long period of time. Moreover, when the content contains a liquid, it becomes possible to prevent evaporation of moisture from the content, and the liquid concentration of the content can be maintained for a long time.

  As a result, the conventional packaging body has a low water vapor barrier property, and thus it is possible to extend the use period of a product that has been discarded in a short period of time, and to reduce the amount of waste. Therefore, it is possible to reduce the total cost of the product and the waste amount of the product and the package.

Further, when the water vapor transmission amount is 0.25 g / m ² · day or less and 0.2 g / m ² · day or less, the above effect can be obtained more remarkably.

  Note that the water vapor transmission amount of the multilayer sheet 1 can be measured by the same method as the measurement of the water vapor transmission amount performed in the water vapor barrier layer 4.

As the oxygen barrier property of the multilayer sheet 1 of the present embodiment, specifically, for example, the oxygen transmission amount is preferably 0.35 cc / m ² · day or less in an atmosphere of 25 ° C. and 60% RH. 0.3 cc / m ² · day or less is more preferable, and 0.25 cc / m ² · day or less is particularly preferable.

If the oxygen permeation amount of the multilayer sheet 1 under an atmosphere of 25 ° C. and 60% RH is 0.35 cc / m ² · day or less, when the multilayer sheet 1 is formed into a package, the contents are removed from external oxygen. It is possible to protect the contents sufficiently, prevent the contents from being oxidized, deteriorated, rotted, rusted, etc., and preserve the contents for a long period of time. Further, since the contents can be stored for a long time without using an antioxidant, it is possible to save the trouble of enclosing the antioxidant in the package and to prevent accidental ingestion of the antioxidant.

Furthermore, when the oxygen permeation amount is 0.3 cc / m ² · day or less and 0.25 cc / m ² · day or less, the above effect can be obtained more remarkably.

  In addition, the measurement of the oxygen permeation amount of the multilayer sheet 1 is based on the method described in the JIS K 7126B method using an oxygen permeability measuring device (for example, “OX-TRAN MODEL 2/21” manufactured by MOCON). Can be done.

  Specifically, the glossiness of the surface layer 5 (or the surface layer 6) on the inner surface side of the multilayer sheet 1 of the present embodiment is preferably 10 or more and 40 or less at 60 °, for example. 15 or more and 35 or less, more preferably 18 or more and 30 or less. If the glossiness is 10 or more, it is possible to suppress variations in the sealing strength between the tray and the lid material obtained by secondary molding of the multilayer sheet 1. Moreover, if glossiness is 40 or less, it can prevent that the multilayer sheets 1 and 1 adhere | attach, and can make the multilayer sheet 1 easy to handle. Furthermore, when the glossiness is 15 or more, 35 or less, 18 or more, and 30 or less, the above effects can be obtained more remarkably.

  Specifically, the glossiness of the surface layer 6 (or the surface layer 5) on the outer surface side of the multilayer sheet 1 of the present embodiment is preferably 70 or more and 98 or less at 60 °, for example. 72.5 or more and 97 or less, more preferably 75 or more and 96 or less. If the glossiness is 70 or more, the gloss of the tray obtained by secondary molding of the multilayer sheet 1 can be improved and the appearance can be improved. Moreover, if the glossiness is 98 or less, the gloss is sufficient and the appearance can be sufficiently satisfied. Further, when the glossiness is 72.5 or more, 97 or less, 75 or more, and 96 or less, the above effect can be obtained more remarkably.

  The glossiness of the multilayer sheet 1 can be measured according to the method described in JIS Z 8741 using a gloss meter (for example, “PG-1” manufactured by Nippon Denshoku Industries Co., Ltd.). .

  In the multilayer sheet 1 of the present embodiment, the triboelectric charge amount between at least one surface layer (that is, at least one of the surface layer 5 and the surface layer 6) and the polypropylene resin pellet is preferably 0.5 nC or less, It is more preferably 0.4 nC or less, and further preferably 0.3 nC or less. When the triboelectric charge amount is within the above range, the surface of the multilayer sheet 1 is difficult to be charged. Thereby, since it becomes difficult for dust to adhere to the surface of the multilayer sheet 1, it is hygienic.

Here, the triboelectric charge between at least one surface layer (at least one of the surface layer 5 and the surface layer 6) of the multilayer sheet 1 and the polypropylene resin pellet is 25 ° C. and 50% RH at a Faraday cup (for example, electro -Tech systems, "MODEL 231" etc.). More specifically, for example, the triboelectric charge amount can be measured by the following procedures (a) to (e).
(A) Using two multilayer sheets 1, a bag having a width of 60 mm and a length of 120 mm is produced.
(B) Prepare resin pellets made of polypropylene resin processed into an elliptic cylinder shape with a minor axis of about 2.5 mm in cross section and a major axis of about 3.0 mm and a pellet length of about 3.5 mm.
(C) After neutralizing the produced bag and the resin pellet, the resin pellet is put in the bag and sealed.
(D) A vibration of 1000 rpm is applied to the bag containing the resin pellets sealed in (c) above for 5 minutes using a vibrator (VortexGenie 2 Digital, manufactured by Scientific Industry).
(E) The amount of electricity stored in the resin pellets taken out of the bag is measured using the Faraday cup described above.

<Method for producing multilayer sheet>
Next, the manufacturing method of the multilayer sheet 1 mentioned above is demonstrated.
The manufacturing method of the multilayer sheet 1 of the present embodiment is not particularly limited, but a co-extrusion T die such as a feed block method or a multi-manifold method in which a raw material resin or the like is melt-extruded by several extruders. Among them, the method of forming a film by the coextrusion T-die method is particularly preferable because it is excellent in controlling the thickness of each layer.

  Subsequent steps include a dry laminating method, an extrusion laminating method, a hot melt laminating method, a wet laminating method, a thermal (thermal) laminating method, etc., in which a single layer sheet or film forming each layer is bonded using an appropriate adhesive. And a combination of these methods. Moreover, you may laminate | stack by the method by coating.

  In addition, when adding an inorganic filler, it is better to use the one previously kneaded by a kneader such as a twin-screw kneader, kneader, Banbury mixer, etc. Is more preferable.

<Packaging body>
Next, a package using the multilayer sheet 1 described above will be described. FIG. 2 is a schematic cross-sectional view of a package 11 that is an embodiment to which the present invention is applied. As shown in FIG. 2, the package 11 according to the present embodiment includes a tray 12 and a lid member 13 and is schematically configured.

  The package 11 of the present embodiment includes, as the contents 14, for example, pharmaceuticals, preparations, infusion preparations, blood preparations, medical equipment, cosmetics, quasi-drugs, foods, beverages, industrial parts, electronic parts, electrical appliances, and the like. It can be used when packaging. Moreover, it can also be used as a secondary packaging container of a primary packaging body in which the contents 14 are packaged. Furthermore, since the multilayer sheet 1 has heat resistance, even the contents 14 that require retort, sterilization, and the like can be applied.

  The tray 12 is obtained by secondary molding of the multilayer sheet 1. Specifically, the multi-layer sheet 1 is recessed to form the storage space S and the edge 15 around the storage space S.

  The method of secondary forming the tray 12 from the multilayer sheet 1 is not particularly limited, and specifically, for example, vacuum forming, pressure forming, pressure vacuum forming, plug assist pressure forming, plug assist vacuum forming, plug assist pressure forming. Examples include vacuum forming, plug forming, and press forming.

  The lid member 13 is bonded to the surface layer 5 on the inner surface side at the edge 15 of the tray 12. Thereby, the storage space S is sealed. The material of the lid member 13 is not particularly limited as long as it can adhere to the tray 12. Specifically, aluminum, a transparent vapor deposition film, etc. are mentioned, for example.

  Since the surface layer 5 is provided on the inner surface side of the tray 12 in the packaging body 11 of the present embodiment, the inner surface is difficult to be charged and dust and the like are not easily attached. Thereby, the contamination in the sealed storage space S and the adhesion of dust or the like to the contents when the contents are taken out from the tray can be reduced.

  In the packaging body 11 of this embodiment, it is preferable that the oxygen barrier layer 2, the water vapor barrier layer 4, and the surface layer 6 serving as the outer surface are laminated in this order from the storage space S side. Thereby, the fall of the oxygen barrier property by the moisture absorption of the oxygen barrier layer 2 is suppressed, and the water vapor barrier property and the oxygen barrier property of the package 11 are exhibited to the maximum, thereby prolonging the protection period of the contents 14. It becomes possible.

  Further, the packaging body 11 of the present embodiment has, from the storage space S side, a surface layer 5 serving as an inner surface, a first water vapor barrier layer 4, an oxygen barrier layer 2, a second water vapor barrier layer 4, The surface layer 6 serving as the outer surface is preferably laminated in this order. That is, it is preferable that the water vapor barrier layers 4 and 4 are provided on both sides of the oxygen barrier layer 2. Thereby, the water vapor barrier property and the oxygen barrier property from the outside are sufficiently exhibited, and at the same time, it is possible to prevent moisture evaporation from the storage space S side.

  Furthermore, since the surface layer 6 is provided on the outer surface side of the tray 12, the outer surface of the package 11 of the present embodiment is not easily charged. Thereby, when taking out the contents from the inner surface of the package 11 and the tray, it is possible to reduce adhesion of dust and the like to the contents.

  As described above, according to the multilayer sheet 1 of the present embodiment, it has the water vapor barrier layer 4, the oxygen barrier layer 2, and the surface layers 5 and 6, and the surface layers 5 and 6 are laminated on the outermost layers on both sides. Since the triboelectric charge amount between at least one surface layer and the polypropylene resin pellets is 0.5 nC or less, it is excellent in water vapor, oxygen barrier property and sealing property, and is excellent in antifouling property because it is difficult for dust to adhere to the surface. .

Further, according to the multilayer sheet 1 of the present embodiment, the water vapor transmission rate at 40 ° C. and 90% RH is 0.3 g / m ² · day or less, and the oxygen transmission rate at 25 ° C. and 60% RH is 0. .35 cc / m ² · day or less and the glossiness of the surface when the surface layer 5 is provided on the inner surface side is 10 or more and 40 or less at 60 °, so that water vapor, oxygen barrier property and sealing property Excellent.

  Further, according to the multilayer sheet 1 of the present embodiment, the glossiness of the surface when the surface layer 6 is provided on the outer surface side is 70 or more and 98 or less at 60 °, so the multilayer sheet 1 is subjected to secondary molding. When the tray is manufactured, the glossiness of the tray is improved and the appearance is excellent.

  Moreover, according to the tray 12 of this embodiment, since it is obtained by secondary molding of the multilayer sheet 1, it is excellent in water vapor, oxygen barrier properties and sealing properties, and dust is contained in the contents when the tray inner surface and the tray are opened. It is hard to adhere and is hygienic.

  Moreover, according to the package 11 of this embodiment, since the tray 12 and the lid member 13 are provided, the water vapor, the oxygen barrier property and the sealing property are excellent, and dust adheres to the inner surface of the tray and the contents when the tray is opened. It is difficult and hygienic.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention. For example, the multilayer sheet 1 described above has a crystal nucleating agent, a petroleum resin, an antistatic agent, an ultraviolet absorber, a lubricant, an antioxidant, a light stabilizer, an antiblocking agent, and a surfactant as long as the basic performance is not impaired. , Dyes, pigments, flame retardants, deodorants, plasticizers, dispersants, and other additives may be added to one or more layers included in the multilayer sheet 1. By including such a layer, the productivity of the multilayer sheet 1 and the package 11 can be improved, deterioration can be prevented, and discrimination can be imparted.

  Moreover, although the multilayer sheet 1 mentioned above demonstrated as an example the structure provided with the outer surface layer 6, it is not limited to this. For example, the structure which is not provided with the outer surface layer 6 may be sufficient.

  Moreover, although the multilayer sheet 1 mentioned above demonstrated as an example the structure provided with the adhesive layer 3 and the water vapor | steam barrier layer 4 2 layers, it is not limited to this. For example, the adhesive layer 3 and the water vapor barrier layer 4 may be configured to include only one layer, or may be configured to include two or more layers.

  Hereinafter, although the effect of the present invention is explained in detail using an example and a comparative example, the present invention is not limited to the following example.

<Production of multilayer sheet>
Example 1
A multilayer sheet having the structure shown in FIG. 1 was produced by the following procedure.
First, an ethylene-vinyl alcohol copolymer (manufactured by Kuraray Co., Ltd., product number: F101A) was prepared as a resin contained in the oxygen barrier layer.
In addition, maleic anhydride-modified polypropylene (manufactured by Mitsubishi Chemical Corporation, product number: ER313E-1) was prepared as the resin contained in the first and second adhesive layers.
In addition, polypropylene (manufactured by Sumitomo Chemical Co., Ltd., product number: Sumitomo Nobrene FS2011DG2) was prepared as the resin contained in the first and second water vapor barrier layers.
In addition, talc (manufactured by Nippon Talc Co., Ltd., product number: K-1) was prepared as an inorganic filler contained in the first and second water vapor barrier layers.
In addition, polypropylene (manufactured by Sumitomo Chemical Co., Ltd., product number: Sumitomo Nobrene FS2011DG2) was prepared as a resin contained in the inner surface layer and the outer surface layer.

  Next, the inner surface layer, the first water vapor barrier layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, the second water vapor barrier layer, and the outer surface layer are combined. A multilayer sheet was produced by coextrusion molding in order. At that time, in the first and second water vapor barrier layers, the mixing ratio was adjusted so that polypropylene was 70 mass% and talc was 30 mass%. Moreover, when fixing a sheet | seat to a cooling roll, the embossing touch roll was used and the fixing pressure was 0.2 MPa.

  The total thickness of the multilayer sheet was 1000 μm. The ratio of the thickness of each layer to the total thickness of the multilayer sheet is 10% for the inner surface layer, 32.5% for the first water vapor barrier layer, 2.5% for the first adhesive layer, and 10% for the oxygen barrier layer. %, The second adhesive layer was 2.5%, the second water vapor barrier layer was 32.5%, and the outer surface layer was 10%.

(Example 2)
A multilayer sheet was produced in the same manner as in Example 1 except that the touch roll pressure when fixing the sheet to the roll was 0.3 MPa.

  The total thickness of the multilayer sheet was 1000 μm. The ratio of the thickness of each layer to the total thickness of the multilayer sheet is 10% for the inner surface layer, 32.5% for the first water vapor barrier layer, 2.5% for the first adhesive layer, and 10% for the oxygen barrier layer. %, The second adhesive layer was 2.5%, the second water vapor barrier layer was 32.5%, and the outer surface layer was 10%.

(Example 3)
A multilayer sheet was produced in the same manner as in Example 1 except that the touch roll pressure when fixing the sheet to the roll was 0.4 Mpa.

  The total thickness of the multilayer sheet was 1000 μm. The ratio of the thickness of each layer to the total thickness of the multilayer sheet is 10% for the inner surface layer, 32.5% for the first water vapor barrier layer, 2.5% for the first adhesive layer, and 10% for the oxygen barrier layer. %, The second adhesive layer was 2.5%, the second water vapor barrier layer was 32.5%, and the outer surface layer was 10%.

(Comparative Example 1)
Resin contained in oxygen barrier layer, resin contained in first and second adhesive layers, resin contained in first and second water vapor barrier layers, inorganic filler contained in first and second water vapor barrier layers As described above, the same resin and inorganic filler used in Example 1 were prepared.

Next, the first water vapor barrier layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, and the second water vapor barrier layer are coextruded in this order to form a multilayer sheet. Produced. At that time, in the first and second water vapor barrier layers, the mixing ratio was adjusted so that polypropylene was 80 mass% and talc was 20 mass%. Moreover, when fixing a sheet | seat to a cooling roll, the embossing touch roll was used and the fixing pressure was 0.2 MPa.
The multilayer sheet of Comparative Example 1 does not have an inner surface layer and an outer surface layer.

  The total thickness of the multilayer sheet was 1000 μm. The ratio of the thickness of each layer to the total thickness of the multilayer sheet is 42.5% for the first water vapor barrier layer, 2.5% for the first adhesive layer, 10% for the oxygen barrier layer, and the second adhesive layer. Was 2.5%, and the second water vapor barrier layer was 42.5%.

(Comparative Example 2)
In the first and second water vapor barrier layers, a multilayer sheet was produced in the same manner as in Comparative Example 1 except that the mixing ratio was adjusted so that polypropylene was 55% by mass and talc was 45% by mass.

  The total thickness of the multilayer sheet was 1000 μm. The ratio of the thickness of each layer to the total thickness of the multilayer sheet is 42.5% for the first water vapor barrier layer, 2.5% for the first adhesive layer, 10% for the oxygen barrier layer, and the second adhesive layer. Was 2.5%, and the second water vapor barrier layer was 42.5%.

<Evaluation of water vapor barrier properties>
The multilayer sheet produced in Examples 1 to 3 and Comparative Examples 1 and 2 and the water vapor barrier layer (single layer) were evaluated for water vapor barrier properties. The evaluation of the water vapor barrier property was performed by measuring the amount of water vapor permeation in an atmosphere of 40 ° C. and 90% RH. The water vapor transmission rate was measured using a water vapor transmission rate measuring device (manufactured by MOCON, “PERMATRAN-W MODEL 3/33”) according to the method described in the JIS K 7129B method. The results are shown in Table 1.

<Evaluation of oxygen barrier properties>
The multilayer sheet produced in Examples 1 to 3 and Comparative Examples 1 and 2 was evaluated for oxygen barrier properties. The oxygen barrier property was evaluated by measuring the oxygen permeation amount in an atmosphere of 25 ° C. and 60% RH. The measurement of the oxygen permeation amount was performed in accordance with the method described in the JIS K 7126B method using an oxygen permeability measuring device (for example, “OX-TRAN MODEL 2/21” manufactured by MOCON). . The results are shown in Table 1.

<Evaluation of glossiness>
The multilayer sheets prepared in Examples 1 to 3 and Comparative Examples 1 and 2 were evaluated for glossiness. The glossiness was evaluated by measuring the glossiness at 60 ° with respect to the inner surface layer and the outer surface layer of the multilayer sheet 1. The glossiness was measured according to the method described in JIS Z 8741 using a gloss meter (Nippon Denshoku Industries Co., Ltd., “PG-1”). Moreover, the measurement was performed 10 times and the average value and deviation of each time were calculated | required. The results are shown in Table 1.

<Evaluation of sealing performance>
Sealability was evaluated using the multilayer sheets prepared in Examples 1 to 3 and Comparative Examples 1 and 2 and an aluminum lid as a lid. The sealability was evaluated by applying a 0.2 MPa load at 190 ° C. for 3 seconds using a hot plate lowering type sealing machine, and sealing the inner surface layer side of the multilayer sheet and the lid material to prepare a seal sample. . Next, the obtained seal sample was cut into a strip shape having a width of 15 mm to prepare a test piece. The test piece was peeled off at a speed of 300 mm / min by a tensile / compression tester (manufactured by A & D), and the maximum load was measured. The unit was N / 15 mm. Each test piece was assumed five times under the same conditions, and the variation in seal strength was evaluated from the difference between the maximum value and the minimum value (maximum value-minimum value) of the seal strength in each test piece.

<Measurement of frictional charge>
For the multilayer sheets prepared in Examples 1 to 3 and Comparative Examples 1 and 2, the triboelectric charge amount on the surface of the multilayer sheet was measured at 25 ° C. and 50% RH. The triboelectric charge amount was measured by the following procedures (a) to (e). The unit of the triboelectric charge amount is “nC”.
(A) A bag having a width of 60 mm and a length of 120 mm is prepared using two multilayer sheets.
(B) Prepare resin pellets made of polypropylene resin processed into an elliptic cylinder shape with a minor axis of about 2.5 mm in cross section and a major axis of about 3.0 mm and a pellet length of about 3.5 mm.
(C) After neutralizing the bag and the resin pellet, the resin pellet is placed in the bag and sealed.
(D) A vibration of 1000 rpm is applied to the bag containing the resin pellets sealed in (c) above for 5 minutes using a vibrator (VortexGenie 2 Digital, manufactured by Scientific Industry).
(E) The amount of electricity stored in the resin pellets taken out from the inside of the bag is measured using a Faraday cup (manufactured by electro-tech systems, FARADAY CUP MODEL231).

<Evaluation of formability and appearance>
The formability and appearance when the multilayer sheets prepared in Examples 1 to 3 and Comparative Examples 1 and 2 were recessed and vacuum-formed into cup-shaped trays were evaluated. The results are shown in Table 1. In addition, in the item of “Formability and Appearance” in Table 1, “◯” indicates that the shape is uniformly formed according to the shape and the appearance is good, and “×” indicates that the shape does not appear or the surface Is rough, indicating that the appearance is poor.

<Evaluation of mass reduction of contents in package>
The multilayer sheets prepared in Examples 1 to 3 and Comparative Examples 1 and 2 were recessed and vacuum formed into cup-shaped trays. Next, a polypropylene bag (thickness: 100 μm) containing 5 g of distilled water was placed in the tray. Next, a package was produced by sealing the tray and the aluminum lid material via the edge of the tray.

  The produced package was stored in an environment of 40 ° C., and the amount of decrease in the mass of the package was measured. The results are shown in Table 1. In addition, regarding the item of “mass loss amount of contents (liquid)” in Table 1, “A” indicates that the mass loss amount is small and distilled water remains for one year or more, and “B” indicates that distilled water is half a year. The above shows that it has remained for less than one year, “C” indicates that distilled water has remained for not less than 3 months and less than half a year, and “D” indicates that distilled water has become less than 3 months.

  As shown in Table 1, according to the multilayer sheets of Examples 1 to 3 having an inner surface layer and an outer surface layer, the glossiness of the surface on the inner surface layer side is 10 or more and 40 or less at 60 °, In addition to being excellent in water vapor and oxygen barrier properties, the triboelectric charge between the multilayer sheet and PP pellets was as small as 0.5 nC or less, and it was confirmed that the antifouling property was excellent.

  Further, according to the multilayer sheets of Examples 1 to 3 having the inner surface layer and the outer surface layer, the glossiness of the surface on the outer surface layer side is in the range of 94 to 96 at 60 °, which is excellent in appearance. I confirmed.

  The multilayer sheet of the present invention may be used as a packaging material for pharmaceuticals, preparations, infusion preparations, blood preparations, medical devices, foods, beverages, industrial members, electronic parts and the like. In addition, the tray and the package of the present invention can be used for packaging pharmaceuticals, cosmetics, quasi-drugs, pharmaceutical preparations, infusion preparations, blood preparations, medical equipment, foods, beverages, industrial parts, electronic parts, and the like. is there.

DESCRIPTION OF SYMBOLS 1 ... Multilayer sheet 2 ... Oxygen barrier layer 3 ... Adhesion layer 4 ... Water vapor barrier layer 5 ... Surface layer (inner surface layer)
6 ... Surface layer (outer surface layer)
DESCRIPTION OF SYMBOLS 11 ... Packaging 12 ... Tray 13 ... Cover material 14 ... Contents 15 ... Edge part S ... Storage space

Claims (10)

A multilayer sheet having a water vapor barrier layer, an oxygen barrier layer, and a surface layer, wherein the surface layer is laminated on the outermost layers on both sides;
A multilayer sheet, wherein the triboelectric charge amount between at least one of the surface layers and the polypropylene resin pellet is 0.5 nC or less.   The multilayer sheet according to claim 1, wherein at least one surface layer and the water vapor barrier layer are laminated adjacent to each other.   The surface layer contains at least one resin selected from polypropylene, polyethylene, high density polyethylene, cyclic olefin polymer, cyclic olefin copolymer, polyvinyl chloride, polyvinylidene chloride, and polychlorotrifluoroethylene. Multilayer sheet.   The multilayer sheet according to claim 3, wherein the water vapor barrier layer includes a resin that is the same as or different from the resin included in the surface layer, and an inorganic filler.   The multilayer sheet according to claim 4, wherein the inorganic filler includes at least one of layered silicates, titanium oxide, and calcium carbonate.   The multilayer sheet according to claim 5, wherein the layered silicate includes at least one of talc, mica, montmorillonite, kaolin, bentonite, and hectorite.   The multilayer sheet according to any one of claims 1 to 6, wherein the multilayer sheet has a thickness of 500 µm or more and 1500 µm or less. The water vapor transmission rate under the conditions of 40 ° C. and 90% RH is 0.3 g / m ² · day or less,
The multilayer sheet according to any one of claims 1 to 7, wherein an oxygen permeation amount under conditions of 25 ° C and 60% RH is 0.35 cc / m ² · day or less.   A tray formed with the multilayer sheet according to claim 1.   A package comprising the tray according to claim 9 and a lid.

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