JP6753048B2 - Multi-layer sheets, trays, and packaging - Google Patents

Description

The present invention relates to multilayer sheets, trays, and packages.

Conventionally, as packaging materials for pharmaceuticals, medical products, foods, beverages and the like, paper, synthetic resin sheets or films, thin-film deposition films, laminates with synthetic resin films, aluminum packaging and the like have been used. When used in the above applications, it has characteristics that require protection of the contents, especially barriers to water vapor and oxygen, and high barriers are required to protect the contents over the long term. ing.

Examples of those satisfying both the water vapor barrier property and the oxygen barrier property as described above include a vapor-deposited film and aluminum packaging. However, although these can be used as a specific package such as a pouch shape, it is difficult to mold them into an arbitrary shape with a molding machine or the like, and the usage is limited.

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

However, the polyolefin-based resin is excellent in water vapor barrier property, but inferior in oxygen barrier property. Therefore, various problems such as oxidation, deterioration, putrefaction, or rusting of the contents may occur.

In order to solve the above problem, for example, Cited Document 1 contains a layer containing a resin having an excellent oxygen barrier property such as an ethylene-vinyl alcohol copolymer and nylon, and a resin having an excellent water vapor barrier property such as a polyolefin. A resin laminate comprising a layer is disclosed.

Special Fair 6-15227

However, the resin laminate disclosed in Patent Document 1 has problems that the water vapor barrier property, the oxygen barrier property, and the sealing property are not sufficient, and the moldability is further inferior.

The present invention has been made in view of the above circumstances, and is a multilayer sheet having excellent water vapor barrier property, oxygen barrier property, sealing property, and excellent moldability, a tray using the same, and a packaging body. The challenge is to provide.

In order to solve the above problems, the invention according to claim 1 is
A multi-layer sheet having a water vapor barrier layer, an oxygen barrier layer, and a surface layer, and the surface layers are laminated on the outermost layers on both sides.
40 ° C., and the water vapor permeability of at 90% RH or less 0.3g ^/ m 2 · day,
25 ° C., the oxygen transmission rate at 60% RH is not more than 0.35cc ^/ m 2 · day,
The water vapor barrier layer contains a resin and an inorganic filler.
In a photograph taken by a scanning electron microscope (SEM) of an arbitrary cross section of the water vapor barrier layer, the ratio of the total area of the resin occupying the water vapor barrier layer is 70% or more and 99% or less, and the surface layer is all SANYO containing no inorganic filler,
The glossiness of the surface of one of the outermost layers at 60 ° measured according to JIS Z 8741 is 10 or more and 40 or less, and the glossiness of the surface of the other outermost layer at 60 ° is 70 or more and 98 or less. It is a multi-layer sheet.

Further, the invention according to claim 2 is
The multilayer sheet according to claim 1, wherein the specific gravity of the multilayer sheet is 0.92 g / cm ³ or more and 1.5 g / cm ³ or less.

Further, the invention according to claim 3 is
The shape of the inorganic filler is plate-like or scaly with an aspect ratio of 5 or more and 200 or less.
The multilayer sheet according to claim 1 or 2, wherein the long axis direction of the inorganic filler is oriented in the plane direction of the water vapor barrier layer.

Further, the invention according to claim 4 is
The multilayer sheet according to any one of claims 1 to 3, wherein the ash content of the multilayer sheet is 1.5% by mass or more and 40% by mass or less.

Further, the invention according to claim 5 is
The multilayer sheet according to any one of claims 1 to 4, wherein the inorganic filler contains at least one of layered silicates, titanium oxide, and calcium carbonate.

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

Further, the invention according to claim 7 is
The multilayer sheet according to any one of claims 1 to 6, wherein the water vapor barrier layer contains the inorganic filler of 10% by mass or more and 40% by mass or less with respect to the mass of the water vapor barrier layer. ..

Further, the invention according to claim 8 is
The 40 ° C. water vapor barrier layer, the water vapor permeation amount of 90% RH is less than 0.8g ^/ m 2 · day, a multilayer sheet according to any one of claims 1 to 7.

Further, the invention according to claim 9 is
The multilayer sheet according to any one of claims 1 to 8, wherein the total thickness of the water vapor barrier layer is 37.5% or more and 90% or less with respect to the thickness of the multilayer sheet.

Further, the invention according to claim 10 is
Any of claims 1 to 9, wherein the water vapor barrier layer contains at least one of polypropylene, polyethylene, high-density polyethylene, cyclic olefin polymer, cyclic olefin copolymer, polyvinyl chloride, polyvinylidene chloride, and polychlorotrifluoroethylene. The multilayer sheet according to item 1.

Further, the invention according to claim 11
The multilayer sheet according to any one of claims 1 to 10, wherein the thickness of the multilayer sheet is 500 μm or more and 1500 μm or less.

Further, the invention according to claim 12 is
It is a tray obtained by secondary molding the multilayer sheet according to claim 1.

Further, the invention according to claim 13 is
A package including the tray according to claim 12 and a lid material.

Multilayer sheet of the present invention, 40 ° C., the water vapor permeability of at 90% RH is not more than ^{0.3g / m 2 · day, 25} ℃, oxygen permeability at 60% RH is 0.35 cc / ^{m 2} · The total area of the resin occupying the water vapor barrier layer in a photograph taken by a scanning electron microscope (SEM) of an arbitrary cross section of the water vapor barrier layer, which is less than or equal to the day and contains the resin and the inorganic filler. Is 70% or more and 99% or less, so that it is excellent in water vapor barrier property, oxygen barrier property, sealing property, and moldability.

Further, since the tray of the present invention is obtained by secondary molding the above-mentioned multilayer sheet, it is excellent in water vapor barrier property, oxygen barrier property, and sealing property.

Further, since the package of the present invention includes the tray and the lid material, it is excellent in water vapor barrier property, oxygen barrier property, and sealing property.

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. 6 is an SEM image showing an arbitrary cross section of the water vapor barrier layer of the multilayer sheet produced in Example 1.

Hereinafter, a multilayer sheet according to an embodiment to which the present invention is applied, a tray obtained by secondary molding the multilayer sheet, and a package provided with the tray will be described in detail. Note that, in the drawings used in the following description, in order to make the features easy to understand, there may be a case where features are enlarged for convenience, and the dimensional ratios of the respective constituent elements are not necessarily the same as the actual ones. Absent.

<Multi-layer sheet>
First, a configuration of a multilayer sheet according to an 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 roughly configured by including an oxygen barrier layer 2, an adhesive layer 3, a water vapor barrier layer 4, an inner surface layer 5, and an outer surface layer 6. Has been done.
The multilayer sheet 1 of the present embodiment can be used as a packaging material for pharmaceuticals, preparations, infusion preparations, blood products, medical devices, cosmetics, quasi-drugs, foods, beverages, industrial parts, electronic parts and the like.

The oxygen barrier layer 2 is a resin layer that suppresses the permeation of oxygen and water vapor, and imparts oxygen barrier property and water vapor barrier property to the multilayer sheet 1. Further, when the multilayer sheet 1 is molded 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 copolymers, polyamides, polyvinyl alcohols, polyacrylonitrile, polyvinylidene chloride and the like. Of these, ethylene-vinyl alcohol copolymers and polyamides are particularly preferable from the viewpoint of film forming property with the water vapor barrier layer 4. The oxygen barrier layer 2 may contain one type of the above resin, or may contain two or more types of the resin. Further, an oxygen absorber may be used as the oxygen barrier layer 2.

The oxygen barrier layer 2 may contain an inorganic filler in addition to the above resin. Specific examples of the inorganic filler include layered silicates such as talc, mica, kaolin, clay, and 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. As the inorganic filler contained in the oxygen barrier layer 2, plate-shaped and scaly fillers having a large aspect ratio are preferable from the viewpoint of improving the barrier property, and among the above-mentioned inorganic fillers, talc and mica are more preferable.

Further, the content of the inorganic filler in the oxygen barrier layer 2 is preferably, for example, 10% by mass or more and 40% by mass or less with respect to the total mass of the oxygen barrier layer 2. More preferably, it is 20% by mass or more and 30% by 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 total mass of the oxygen barrier layer 2, the water vapor barrier property of the oxygen barrier layer 2 is improved, and the entire multilayer sheet 1 is used. As a result, the water vapor barrier property can be dramatically improved. Further, when the content of the inorganic filler in the oxygen barrier layer 2 is 40% by mass or less with respect to the total mass of the oxygen barrier layer 2, the film-forming property of the sheet and the moldability into the package are deteriorated. You can prevent it from happening.

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. Further, when the thickness of the oxygen barrier layer 2 is 300 μm or less, it is easy to mold at the time of container molding, and the elongation as a sheet can be maintained. Further, when the thickness is 25 μm or more and 200 μm or less, the above effect can be obtained more remarkably.

The ratio of the thickness 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. It is more preferably% or more and 15% or less. When the ratio of the thickness of the oxygen barrier layer 2 to the total thickness of the multilayer sheet 1 is 2.5% or more, the oxygen barrier property and the water vapor barrier property can be sufficiently exhibited. Further, 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 the oxygen barrier property can be sufficiently expressed. Further, when the ratio is 5% or more and 15% or less, the above effect can be obtained more remarkably.

The adhesive layer 3 is laminated one layer on each side of the oxygen barrier layer 2. The adhesive layer 3 can bond the oxygen barrier layer 2 and the water vapor barrier layer 4. The material of the adhesive layer 3 is not particularly limited as long as it can bond the oxygen barrier layer 2 and the water vapor barrier layer 4. Specific examples thereof include an adhesive resin such as maleic anhydride-modified olefin, and a resin mixed with a resin contained in the oxygen barrier layer 2 and the water vapor barrier layer 4.

The water vapor barrier layer 4 is laminated one by one on the surface of the adhesive layer 3 opposite to the oxygen barrier layer 2. The water vapor barrier layer 4 is a resin layer that suppresses the permeation of water vapor, and imparts water vapor barrier properties to the multilayer sheet 1. Further, when the multilayer sheet 1 is molded into a package, the contents can be protected and the permeation of water vapor into the package can be suppressed. Further, as a result, it is possible to suppress a decrease in oxygen barrier property due to moisture absorption of the oxygen barrier layer 2. Further, since the intermolecular hydrogen bonds of the resin constituting the oxygen barrier layer 2 are prevented from being cleaved by water vapor and the molecular gaps 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 polyolefin resins such as polypropylene, polyethylene, high-density polyethylene, cyclic olefin polymers, and cyclic olefin copolymers, polyvinyl chloride, polyvinylidene chloride, and polychlorotri. Examples thereof include resins containing halogen atoms such as fluoroethylene. Among these, polypropylene, polyethylene, and high-density polyethylene are preferable from the viewpoints of moldability to the multilayer sheet 1, moldability to the package, sealability with the lid material, and cost. The water vapor barrier layer 4 may contain one type of the above resin, or may contain two or more types of the resin.

The water vapor barrier layer 4 preferably contains an inorganic filler in addition to the above resin. Specifically, as the shape of the inorganic filler, for example, the aspect ratio is preferably 5 or more and 200 or less, more preferably 7.5 or more and 150 or less, and 10 or more and 100 or less. Is particularly preferred. Further, it is preferable that the long axis direction of the inorganic filler is oriented in the plane direction of the water vapor barrier layer 4. Since the long axis direction of the inorganic filler is oriented in the plane direction of the water vapor barrier layer 4, the water vapor barrier property can be improved even with a small amount of addition. Further, when the aspect ratio is 5 or more, the effect of improving the water vapor barrier property when the inorganic filler is oriented can be obtained more remarkably. On the other hand, when the aspect ratio is 200 or less, the inorganic filler can be uniformly dispersed in the resin. Further, when the aspect ratio is 7.5 or more, 150 or less, 10 or more, and 100 or less, the above effect can be obtained more remarkably.

Specific examples of the inorganic filler include layered silicates such as talc, mica, montmorillonite, kaolin, clay, bentonite, and hectrite, silica, calcium carbonate, magnesium carbonate, calcium sulfate, magnesium sulfate, and barium sulfate. , Glass filler, glass fiber, glass beads, titanium oxide, aluminum oxide, iron, zinc, aluminum and the like. The water vapor barrier layer 4 may contain one type of the above-mentioned inorganic filler, or may contain two or more types of the above-mentioned inorganic filler. Among the above-mentioned inorganic fillers, talc and mica, which are plate-shaped or scaly inorganic fillers having a large aspect ratio, are more preferable.

The content of the inorganic filler in the water vapor barrier layer 4 is preferably, for example, 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% by mass or more and 30% by 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 total mass of the water vapor barrier layer 4, the water vapor barrier property of the water vapor barrier layer 4 is improved, and the entire multilayer sheet 1 is used. As a result, the water vapor barrier property can be dramatically improved. Further, since the content of the inorganic filler in the water vapor barrier layer 4 is 40% by mass or less with respect to the total mass of the water vapor barrier layer 4, the film-forming property of the multilayer sheet 1 and the moldability into a package are formed. Can be prevented from getting worse.

In a photograph (hereinafter, sometimes referred to as "SEM image") of an arbitrary cross section of the water vapor barrier layer 4 taken with a scanning electron microscope (SEM, for example, JSM-7401F manufactured by JEOL Ltd.), water vapor The ratio of the total area of the resin in the barrier layer 4 is preferably 70% or more and 99% or less, and more preferably 75% or more and 95% or less of the cross-sectional area of the water vapor barrier layer 4. When the ratio of the total area of the resin is 70% or more, the film-forming property of the sheet and the moldability into the package can be maintained. Further, when the ratio of the total area of the resin is 75% or more, the above effect can be obtained more remarkably.

The ratio of the total area of the resin can be obtained by binarizing the SEM image using image analysis software (for example, Image J manufactured by the National Institutes of Health).

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. Further, 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 molded into a package. Further, when the thickness is 300 μm or more and 500 μm or less, the above effect can be obtained more remarkably.

The ratio of the total thickness of the two layers of the water vapor barrier layer 4 is not particularly limited, but specifically, for example, it may be 37.5% or more and 90% or less with respect to the total thickness of the multilayer sheet 1. It is preferably 45% or more and 85% or less, more preferably. 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 entire sheet. Further, since 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 secure sufficient oxygen barrier property in addition to the water vapor barrier property. it can. Further, when the ratio is 45% or more and 85% or less, the above effect can be obtained more remarkably.

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

The water vapor permeation amount of the water vapor barrier layer 4 is measured by using a water vapor permeation measuring device (for example, "PERMATRAN-W MODEL 3/33" manufactured by MOCON) according to the method described in JIS K 7129B method. Can be done compliant.

The inner surface layer 5 is laminated on one of the surfaces of the water vapor barrier layer 4 on the opposite side of the adhesive layer 3. The inner surface layer 5 is one outermost layer of the multilayer sheet 1. The inner surface layer 5 imparts a sealing property to the multilayer sheet 1. Further, when the multilayer sheet 1 is formed into a tray, it is possible to suppress variations in the sealing strength between the tray and the lid material and at the same time improve the sealing property.

The resin contained in the inner surface layer 5 is not particularly limited as long as it is a resin that can be adhered to the water vapor barrier layer 4 and the lid material. Specific examples thereof include polyolefin-based resins such as polypropylene and polyethylene, cyclic polyolefin-based resins, polyester-based resins, and halogen-based resins. The inner surface layer 5 may contain one type of the above resin, or may contain two or more types of the resin. By selecting the above resin, the sealing strength between the tray obtained by molding the multilayer sheet 1 and the lid material can be made sufficient.

Further, the inner surface layer 5 preferably does not contain an inorganic filler. That is, the inner surface layer 5 is preferably a layer made of only resin.
By the way, the water vapor barrier layer 4 preferably contains an inorganic filler as described above. However, when the layer containing the inorganic filler is used as the outermost layer, the sealing strength between the tray on which the multilayer sheet 1 is molded and the lid material varies widely, and sufficient sealing properties cannot be obtained. On the other hand, by using the inner surface layer 5 containing no inorganic filler as the outermost layer, it is possible to suppress variations in the sealing strength and improve the sealing property.

Further, since the inner surface layer 5 does not contain the inorganic filler, when the multilayer sheet 1 adheres to the die lip during the production of the multilayer sheet 1, the inorganic filler or the like adheres to the die lip, resulting in a decrease in productivity. Can be prevented.

The outer surface layer 6 is laminated on the other side of the water vapor barrier layer 4 on the opposite side of the adhesive layer 3 side. The outer surface layer 6 is the other outermost layer of the multilayer sheet 1. The outer surface layer 6 imparts gloss to the multilayer sheet 1. Further, when the multilayer sheet 1 is formed into a tray, the gloss of the tray can be improved and the appearance can be improved.

As the resin contained in the outer surface layer 6, the same resin as the inner surface layer 5 can be used. Further, it is preferable that the outer surface layer 6 does not contain an inorganic filler like the inner surface layer 5.
By the way, when the water vapor barrier layer 4 is used as the outermost layer, the glossiness of the multilayer sheet 1 may be lost because the water vapor barrier layer 4 contains an inorganic filler. However, by using the outer surface layer 6 containing no inorganic filler as the outermost layer, the glossiness of the other surface side of the multilayer sheet 1 can be made sufficient.

The thickness of the inner surface layer 5 and the outer surface layer 6 is not particularly limited, but specifically, for example, it is preferably 12.5 μm or more and 280 μm or less, and more preferably 25 μm or more and 200 μm or less. preferable. When the thickness of the inner surface layer 5 and the outer surface layer 6 is 12.5 μm or more, the seal strength can be stabilized and the glossiness can be sufficiently exhibited. Further, when the thickness of the inner surface layer 5 and the outer surface layer 6 is 280 μm or less, the water vapor barrier property can be sufficiently exhibited. Further, when the thickness is 25 μm or more and 200 μm or less, the above effect can be obtained more remarkably.

The ratio of the total thickness of the inner surface layer 5 and the outer surface layer 6 is not particularly limited, but specifically, for example, it is 2.5% or more and 56% or less with respect to the total thickness of the multilayer sheet 1. It is preferably 5% or more, and more preferably 40% or less. When the ratio of the total thickness of the inner surface layer 5 and the outer surface layer 6 is 2.5% or more with respect to the total thickness of the multilayer sheet 1, the seal strength is stabilized and the glossiness is sufficiently exhibited. be able to. Further, when the ratio of the total thickness of the inner surface layer 5 and the outer surface layer 6 is 56% or less with respect to the total thickness of the multilayer sheet 1, sufficient water vapor barrier property can be ensured. Further, when the ratio is 5% or more and 40% or less, the above effect can be obtained more remarkably.

The total thickness of the multilayer sheet 1 of the present embodiment is not particularly limited, but specifically, for example, it is preferably 500 μm or more and 1500 μm or less, and more preferably 800 μm or more and 1350 μm or less. When 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. Further, when the total thickness of the multilayer sheet 1 is 1500 μm or less, the molding cycle into the 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.

As the water vapor barrier property of the multilayer sheet 1 of the present embodiment, specifically, for example, the water vapor permeation amount is preferably 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, and particularly preferably 0.2 g / m ² · day or less.

When the multi-layer sheet 1 is molded into a package because the amount of water vapor permeation of the multi-layer sheet 1 in an atmosphere of 40 ° C. and 90% RH is 0.3 g / m ² · day or less, the contents are external moisture. It is possible to sufficiently protect the contents from water vapor, and it is possible to store the contents sensitive to moisture for a long period of time. Further, when the content contains a liquid, it is possible to prevent evaporation of water from the content, and it is possible to maintain the liquid concentration of the content for a long period of time.

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

Further, when the water vapor permeation 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.

The water vapor permeation amount of the multilayer sheet 1 can be measured by the same method as the water vapor permeation amount measurement 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 permeation 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, and particularly preferably 0.25 cc / m ² · day or less.

When the multi-layer sheet 1 is molded into a package because the oxygen permeation amount of the multi-layer sheet 1 in an atmosphere of 25 ° C. and 60% RH is 0.35 cc / m ² · day or less, the contents are external oxygen. It is possible to sufficiently protect the contents from oxidation, deterioration, putrefaction, rust, etc. of the contents, and to store the contents for a long period of time. Further, since the contents can be stored for a long period of time without using an antioxidant, it is possible to save the trouble of enclosing the antioxidant in the package and at the same time prevent accidental ingestion of the antioxidant.

Further, 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.

The oxygen permeation amount of the multilayer sheet 1 is measured in accordance with the method described in JIS K 7126B method using an oxygen permeation rate measuring device (for example, "OX-TRAN MODEL 2/21" manufactured by MOCON). Can be done.

The specific gravity of the multilayer sheet 1 of the present embodiment is preferably 0.92 g / cm ³ or more and 1.5 g / cm ³ or less, and 0.95 g / cm ³ or more and 1.3 g / cm ³ or less. It is more preferable, and 1.0 g / cm ³ or more and 1.2 g / cm ³ or less are particularly preferable. When the specific gravity of the multilayer sheet 1 is 0.92 g / cm ³ or more, the required level of barrier properties (water vapor, oxygen) can be exhibited, and sufficient rigidity can be maintained for use. On the other hand, since the specific gravity of the multilayer sheet 1 is 1.5 g / cm ³ or less, the weight of the multilayer sheet 1 is practically not heavy and it is easy to handle when using the multilayer sheet 1. Further, the above effect is more remarkable when the specific gravity of the multilayer sheet 1 is 0.95 g / cm ³ or more, 1.3 g / cm ³ or less, 1.0 g / cm ³ or more, and 1.2 g / cm ³ or less. Can be obtained.

The specific gravity of the multilayer sheet 1 can be measured using an electronic hydrometer (for example, manufactured by Alpha-Mirage, SD-200L, etc.).

The ash content of the multilayer sheet 1 of the present embodiment is preferably 1.5% by mass or more and 40% by mass or less, more preferably 2.5% by mass or more and 30% by mass or less, and 5.0. It is particularly preferably 5% by mass or more and 25% by mass or less. When the ash content of the multilayer sheet 1 is 1.5% by mass or more, it is possible to impart light-shielding property, barrier property, rigidity and the like to the sheet. On the other hand, since the ash content of the multilayer sheet 1 is 40% by mass or less, the weight of the multilayer sheet 1 is not heavy and it is easy to handle when using the multilayer sheet 1. In addition, it is easy to perform secondary molding into a container or the like. Further, when the ash content of the multilayer sheet 1 is 2.5% by mass or more, 30% by mass or less, 5.0% by mass or more, and 25% by mass or less, the above effect can be obtained more remarkably.

The ash content of the multilayer sheet 1 can be measured according to the method described in JIS K 72501 (method A).

Specifically, the glossiness of the surface of the multilayer sheet 1 of the present embodiment on the inner surface layer 5 side is preferably 10 or more and 40 or less, and 15 or more and 35 or less, for example, at 60 °. Is more preferable, and 18 or more and 30 or less are particularly preferable. When 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 the multilayer sheet 1. Further, when the glossiness is 40 or less, it is possible to prevent the multilayer sheets 1 and 1 from adhering to each other and to make the multilayer sheet 1 easy to handle. Further, when the glossiness is 15 or more, 35 or less, 18 or more, and 30 or less, the above effect can be obtained more remarkably.

Specifically, the glossiness of the surface of the multilayer sheet 1 of the present embodiment on the outer surface layer 6 side is preferably 70 or more and 98 or less at 60 °, and 72.5 or more and 97 or less. It is more preferable that there is 75 or more, and 96 or less is particularly preferable. When the glossiness is 70 or more, the gloss of the tray obtained by secondary molding the multilayer sheet 1 can be improved, and the appearance can be improved. Further, when 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 by using a gloss meter (for example, "PG-1" manufactured by Nippon Denshoku Kogyo Co., Ltd.) in accordance with the method described in JIS Z 8741. ..

<Manufacturing method of multilayer sheet>
Next, the method for manufacturing the multilayer sheet 1 described above will be described.
The method for manufacturing the multilayer sheet 1 of the present embodiment is not particularly limited, but is a coextrusion T-die such as a feed block method or a multi-manifold method in which a resin or the like as a raw material is melt-extruded by several extruders. Examples thereof include a method, an air-cooled or water-cooled coextrusion inflation method, and a laminating method. 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 (heat) laminating method, etc., in which a single-layer sheet or film forming each layer is bonded together using an appropriate adhesive. And those methods are used in combination. Further, it may be laminated by a coating method.

In addition, when adding an inorganic filler, it is better to use one that has been pre-kneaded with a kneader such as a twin-screw kneader, a kneader, or a Banbury mixer for sheet performance and contamination due to scattering of the inorganic filler during sheet film formation. It is more preferable because it can prevent.

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

The package 11 of the present embodiment wraps pharmaceuticals, preparations, infusion preparations, blood products, medical devices, cosmetics, quasi-drugs, foods, beverages, industrial parts, electronic parts, electrical appliances, etc. as the contents 14. Can be used for. It can also be used as a secondary packaging container for a primary packaging body in which the contents 14 are packaged. Further, even in the content 14 that requires retort, sterilization, etc., the multilayer sheet can be used because it has heat resistance.

The tray 12 is obtained by secondary molding the multilayer sheet 1. Specifically, by denting the multilayer sheet 1, the storage space S and the edge portion 15 are formed around the storage space S.

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

The lid material 13 is adhered to the inner surface layer 5 side of the tray 12 at the edge portion 15. As a result, the storage space S is sealed. The material of the lid material 13 is not particularly limited as long as it adheres to the tray 12. Specific examples thereof include aluminum and transparent vapor-deposited films.

In the package 11 of the present embodiment, the oxygen barrier layer 2, the water vapor barrier layer 4, and the outer surface layer 6 are preferably laminated in this order from the storage space S side. As a result, the decrease in oxygen barrier property due to moisture absorption of the oxygen barrier layer 2 is suppressed, and the water vapor barrier property and oxygen barrier property of the package 11 are maximized, so that the protection period of the content 14 can be extended. It will be possible.

Further, the package 11 of the present embodiment has an inner surface layer 5, a first water vapor barrier layer 4, an oxygen barrier layer 2, a second water vapor barrier layer 4, and an outer surface layer from the storage space S side. It is preferable that 6 and 6 are laminated in this order. That is, it is preferable that the water vapor barrier layers 4 and 4 are laminated on both sides of the oxygen barrier layer 2. As a result, the water vapor barrier property and the oxygen barrier property from the outside can be sufficiently exhibited, and at the same time, the evaporation of water from the storage space S side can be prevented.

As described above, according to the multilayer sheet 1 of the present embodiment, the amount of water vapor permeation at 40 ° C. and 90% RH is 0.3 g / m ² · day or less, and oxygen at 25 ° C. and 60% RH. The permeation amount was 0.35 cc / m ² · day or less, the water vapor barrier layer 4 contained a resin and an inorganic filler, and the image was taken with a scanning electron microscope (SEM) of an arbitrary cross section of the water vapor barrier layer 4. In the photograph, since the ratio of the total area of the resin occupying the water vapor barrier layer 4 is 70% or more and 99% or less, the water vapor barrier property, the oxygen barrier property, the sealing property are excellent, and the moldability is excellent.

Further, according to the multilayer sheet 1 of the present embodiment, since the specific gravity is 0.92 g / cm ³ or more and 1.5 g / cm ³ or less, the barrier property and rigidity are maintained, and the sheet's own weight is not heavy in practice. Easy to handle.

Further, according to the multilayer sheet 1 of the present embodiment, the shape of the inorganic filler contained in the water vapor barrier layer 4 is a plate shape or a scale shape having an aspect ratio of 5 or more and 200 or less, and the inorganic filler is in the long axis direction. However, since the water vapor barrier layer 4 is oriented in the plane direction, the water vapor barrier property can be improved even with a small amount of addition.

Further, according to the multilayer sheet 1 of the present embodiment, since the ash content is 1.5% by mass or more and 40% by mass or less, a sheet having a light-shielding property and a barrier property can be obtained, and molding into a container or the like can be obtained. Easy to perform secondary molding.

Further, according to the tray 12 of the present embodiment, since it is obtained by secondary molding the multilayer sheet 1, it is excellent in water vapor barrier property, oxygen barrier property, and sealing property.

Further, according to the package 11 of the present embodiment, since the tray 12 and the lid material 13 are provided, the packaging has excellent water vapor barrier property, oxygen barrier property, and sealing property.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes designs and the like within a range that does not deviate from the gist of the present invention. For example, the above-mentioned multilayer sheet 1 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 the like may be added to one or more layers contained in the multilayer sheet 1. By including such a layer, it is possible to improve the productivity of the multilayer sheet 1 and the package 11, prevent deterioration, and impart distinctiveness.

Further, although the above-mentioned example in which the multilayer sheet 1 includes the outer surface layer 6 has been described, the present invention is not limited to this form. For example, the outer surface layer 6 may not be provided.

Further, although the above-mentioned example in which the multilayer sheet 1 includes two layers each of the adhesive layer 3 and the water vapor barrier layer 4 has been described, the present invention is not limited to this form. For example, the adhesive layer 3 and the water vapor barrier layer 4 may each include only one layer, or may include two or more layers.

Hereinafter, the effects of the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

<Making a multi-layer sheet>
(Example 1)
As a resin contained in the oxygen barrier layer, an ethylene-vinyl alcohol copolymer (manufactured by Kuraray Co., Ltd., product number: F101A) was prepared.
Further, as the resin contained in the first and second adhesive layers, maleic anhydride-modified polypropylene (manufactured by Mitsubishi Chemical Corporation, product number: ER313E-1) was prepared.
Further, polypropylene (manufactured by Sumitomo Chemical Co., Ltd., product number: Sumitomo Noblen FS2011DG2) was prepared as the resin contained in the first and second water vapor barrier layers.
Further, as an inorganic filler contained in the first and second water vapor barrier layers, talc (manufactured by Nippon Talc Co., Ltd., product number: K-1, aspect ratio: 12, shape: plate shape) was prepared.
Further, polypropylene (manufactured by Sumitomo Chemical Co., Ltd., product number: Sumitomo Noblen 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 formed. Multi-layer sheets were 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% by mass and talc was 30% by mass. Further, when fixing the sheet to the cooling roll, an embossed touch roll was used, and the fixing pressure was set to 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%.

Moreover, when the specific gravity of the multilayer sheet was measured by an electronic hydrometer (SD-200L manufactured by Alpha-Mirage), the specific gravity was 1.07 g / cm ³ .

(Example 2)
A multilayer sheet was produced in the same manner as in Example 1 except that spherical silica (manufactured by Admatex Co., Ltd., product number: SO-C6, aspect ratio: 1, shape: spherical) was used as the inorganic filler.

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%.

Moreover, when the specific gravity of the multilayer sheet was measured by the same method as in Example 1, the specific gravity was 1.05 g / cm ³ .

(Example 3)
In the first and second water vapor barrier layers, a multilayer sheet was produced in the same manner as in Example 1 except that the mixing ratio was adjusted so that polypropylene was 50% by mass and talc was 50% 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 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%.

Moreover, when the specific gravity of the multilayer sheet was measured by the same method as in Example 1, the specific gravity was 1.39 g / cm ³ .

(Comparative Example 1)
In the first and second water vapor barrier layers, a multilayer sheet was produced in the same manner as in Example 1 except that the mixing ratio was adjusted so that polypropylene was 40% by mass and talc was 60% 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 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%.

Moreover, when the specific gravity of the multilayer sheet was measured by the same method as in Example 1, the specific gravity was 1.54 g / cm ³ .

(Comparative Example 2)
Resin contained in the oxygen barrier layer, resin contained in the first and second adhesive layers, resin contained in the first and second water vapor barrier layers, and an inorganic filler contained in the first and second water vapor barrier layers. As the above-mentioned resin and inorganic filler used in Example 1, the same ones 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. Made. At that time, in the first and second water vapor barrier layers, the mixing ratio was adjusted so that polypropylene was 80% by mass and talc was 20% by mass. Further, when fixing the sheet to the cooling roll, an embossed touch roll was used, and the fixing pressure was set to 0.2 MPa.
The multilayer sheet of Comparative Example 2 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%.

Moreover, when the specific gravity of the multilayer sheet was measured by the same method as in Example 1, the specific gravity was 1.06 g / cm ³ .

<Evaluation of water vapor barrier property>
The water vapor barrier property was evaluated for the multilayer sheets prepared in Examples 1 to 3 and Comparative Examples 1 and 2 and the water vapor barrier layer (single layer). 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 permeation amount was measured using a water vapor permeation rate measuring device (“PERMATRAN-W MODEL 3/33” manufactured by MOCON) in accordance with the method described in JIS K 7129B method. The results are shown in Table 1.

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

<Evaluation by SEM>
With respect to the multilayer sheets prepared in Examples 1 to 3, an arbitrary cross section of the water vapor barrier layer was observed using a scanning electron microscope (SEM, manufactured by JEOL Ltd., JSM-7401F). FIG. 3 shows an SEM image of the multilayer sheet produced in Example 1. As shown in FIG. 3, in the water vapor barrier layer of the multilayer sheet produced in Example 1, it was confirmed that the long axis direction of the inorganic filler was oriented in the plane direction of the water vapor barrier layer.

Moreover, in the SEM image, the ratio of the total area of the resin in the water vapor barrier layer was evaluated. The ratio of the total area of the resin was evaluated by binarizing the SEM image using image analysis software (Image J, manufactured by National Institutes of Health). The results are shown in Table 1.

<Evaluation of ash>
The ash content of the multilayer sheets prepared in Examples 1 to 3 and Comparative Examples 1 and 2 was evaluated. The ash content was evaluated according to the method described in JIS K 72501 (Method A). The results are shown in Table 1.

<Evaluation of glossiness>
The glossiness of the multilayer sheets produced in Examples 1 to 3 and Comparative Examples 1 and 2 was evaluated. 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. The glossiness was measured by using a gloss meter (manufactured by Nippon Denshoku Kogyo Co., Ltd., "PG-1") in accordance with the method described in JIS Z 8741. In addition, the measurement was performed 10 times, and the average value and deviation of each time were obtained. The results are shown in Table 1.

<Evaluation of sealing performance>
The sealing property was evaluated using the multilayer sheet produced in Examples 1 to 3 and Comparative Examples 1 and 2 and an aluminum lid material as a lid material. For the evaluation of the sealing property, a sealing sample was prepared by applying a load of 0.2 MPa at 190 ° C. for 3 seconds to seal the inner surface layer side of the multilayer sheet and the lid material using a hot plate lowering type sealing machine. .. Next, the obtained seal sample was cut into strips having a width of 15 mm to prepare test pieces. The test piece was peeled off at a speed of 300 mm / min with a tensile / compression tester (manufactured by A & D Co., Ltd.), and the maximum load was measured. The unit was N / 15 mm. Assumptions were made 5 times for each test piece 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.

<Evaluation of moldability and appearance>
The moldability and appearance of the multilayer sheets produced in Examples 1 to 3 and Comparative Examples 1 and 2 when they were dented and vacuum formed into a cup-shaped tray were evaluated. The results are shown in Table 1. Regarding the items of "formability and appearance" in Table 1, "○" indicates that the product can be molded uniformly according to the shape and the appearance is good, and "x" indicates that the shape does not appear or the surface. Is rough, indicating a poor appearance.

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

The prepared package was stored in an environment of 40 ° C., and the amount of decrease in mass of the package was measured. The results are shown in Table 1. Regarding the item of "mass loss of contents (liquid)" in Table 1, "A" indicates that the mass loss was small and distilled water remained for one year or more, and "B" indicates that distilled water remained for half a year. "C" indicates that distilled water remained for 3 months or more and less than half a year, and "D" indicates that distilled water remained for less than 3 months.

As shown in Table 1, in the SEM image of an arbitrary cross section of the water vapor barrier layer, the ratio of the total area of the resin occupying the water vapor barrier layer is 70% or more and 99% or less. According to this, it was confirmed that the water vapor barrier property, the oxygen barrier property, the sealing property were excellent, and the moldability was excellent.

On the other hand, it was confirmed that the multilayer sheet of Comparative Example 1 in which the ratio of the total area of the resin occupying the water vapor barrier layer was less than 70% was inferior in moldability and appearance.

Further, in the multilayer sheet of Comparative Example 2 which does not have the inner surface layer and the outer surface layer, the glossiness of the surface on the inner surface layer side is less than 10 at 60 °, and the sealing strength varies (maximum value-). It was confirmed that the minimum value) was large and the sealing performance was inferior.

Further, the multilayer sheet of Example 1 using the inorganic filler having an aspect ratio of 5 or more is added with the inorganic filler as compared with the multilayer sheet of Example 2 using the inorganic filler having an aspect ratio of less than 5. It was confirmed that the steam barrier property was excellent even though the rates were the same.

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

1 ... Multi-layer sheet 2 ... Oxygen barrier layer 3 ... Adhesive layer 4 ... Water vapor barrier layer 5 ... Inner surface layer (one surface layer)
6 ... Outer surface layer (the other surface layer)
11 ... Package 12 ... Tray 13 ... Lid 14 ... Contents 15 ... Edge S ... Storage space

Claims (13)

A multi-layer sheet having a water vapor barrier layer, an oxygen barrier layer, and a surface layer, and the surface layers are laminated on the outermost layers on both sides.
40 ° C., and the water vapor permeability of at 90% RH or less 0.3g ^/ m 2 · day,
25 ° C., the oxygen transmission rate at 60% RH is not more than 0.35cc ^/ m 2 · day,
The water vapor barrier layer contains a resin and an inorganic filler.
In a photograph taken by a scanning electron microscope (SEM) of an arbitrary cross section of the water vapor barrier layer, the ratio of the total area of the resin occupying the water vapor barrier layer is 70% or more and 99% or less.
All SANYO that the surface layer does not contain an inorganic filler,
The glossiness of the surface of one of the outermost layers at 60 ° measured according to JIS Z 8741 is 10 or more and 40 or less, and the glossiness of the surface of the other outermost layer at 60 ° is 70 or more and 98 or less. A multi-layer sheet. The multilayer sheet according to claim 1, wherein the specific gravity of the multilayer sheet is 0.92 g / cm ³ or more and 1.5 g / cm ³ or less. Claim 1 that the shape of the inorganic filler is plate-like or scaly with an aspect ratio of 5 or more and 200 or less, and the long axis direction of the inorganic filler is oriented in the plane direction of the water vapor barrier layer. Or the multilayer sheet according to 2. The multilayer sheet according to any one of claims 1 to 3, wherein the ash content of the multilayer sheet is 1.5% by mass or more and 40% by mass or less. The multilayer sheet according to any one of claims 1 to 4, wherein the inorganic filler contains at least one of layered silicates, titanium oxide, and calcium carbonate. The multilayer sheet according to claim 5, wherein the layered silicates contain 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 water vapor barrier layer contains 10% by mass or more and 40% by mass or less of the inorganic filler with respect to the mass of the water vapor barrier layer. The 40 ° C. water vapor barrier layer, the water vapor permeation amount of 90% RH is less than 0.8g ^/ m 2 · day, the multilayer sheet according to any one of claims 1 to 7. The multilayer sheet according to any one of claims 1 to 8, wherein the total thickness of the water vapor barrier layer is 37.5% or more and 90% or less with respect to the thickness of the multilayer sheet. Any of claims 1 to 9, wherein the water vapor barrier layer contains at least one of polypropylene, polyethylene, high-density polyethylene, cyclic olefin polymer, cyclic olefin copolymer, polyvinyl chloride, polyvinylidene chloride, and polychlorotrifluoroethylene. The multilayer sheet described in item 1. The multilayer sheet according to any one of claims 1 to 10, wherein the thickness of the multilayer sheet is 500 μm or more and 1500 μm or less. A tray obtained by secondary molding the multilayer sheet according to claim 1. A packaging body comprising the tray according to claim 12 and a lid material.