JP7586478B2 - Aluminum foil laminate for PTP packaging - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act On May 12, 2020, the aluminum foil laminate for PTP packaging invented by Kazuki Takaishi was shipped to Kanae Co., Ltd.

This disclosure relates to an aluminum foil laminate for PTP packaging.

PTP packages, which are widely used for packaging pharmaceuticals and the like, consist of a container portion for containing the contents and a lid material for sealing the container portion. The container portion has a flat portion that is bonded to the lid material when sealed, and a recess for containing the contents. The lid material generally has a base material made of aluminum foil and a seal layer that has heat sealability and is laminated to the base material. PTP packages can protect and seal the contents by heat welding the flat portion of the container portion to the seal layer of the lid material.

However, some pharmaceutical products packaged in PTP packages emit a peculiar odor, and PTP packages with deodorizing functions have been developed.

For example, Patent Document 1 discloses providing an absorbent layer made of resin with an absorbent added that absorbs odorous components on the surface of the container that comes into contact with the contents. Patent Document 2 discloses providing a functional layer made of a mixture of a resin material and a functional substance with deodorizing properties on the lid material.

JP 2013-199283 A JP 2017-1729 A

In recent years, there has been a demand for adding deodorizing functionality to lid materials using methods other than those described in Patent Document 2.

The objective of the present invention is to provide an aluminum foil laminate for PTP packaging that has an added deodorizing function without increasing the number of manufacturing steps.

The PTP packaging aluminum foil laminate of the present invention is an aluminum foil laminate for PTP packaging comprising a base material made of aluminum foil and a seal layer provided on the base material, the seal layer containing an inorganic porous body and a heat sealable resin, the basis weight of the seal layer is 2 g/m ² or more and 10 g/m ² or less, and the content of the inorganic porous body in the seal layer is 20% by mass or more and 40% by mass or less. Here, the basis weight means the mass per unit area. By adopting such a configuration, it is possible to realize an aluminum foil laminate for PTP packaging with an excellent deodorizing function without increasing the manufacturing process compared to the conventional method.

The average particle size of the inorganic porous body is preferably 0.1 μm or more and 10 μm or less.

The sealing layer preferably has a basis weight of 3 g/m ² or more and 7 g/m ² or less.

According to the present invention, by setting the basis weight of the sealing layer to 2 g/m2 or ^more and 10 g/m2 ^or less and setting the content of the inorganic porous body in the sealing layer to 20 mass% or more and 40 mass% or less, it is possible to impart excellent deodorizing function without increasing the manufacturing process compared to the conventional case.

FIG. 1 is a schematic cross-sectional view of a PTP packaging aluminum foil laminate according to an embodiment. FIG. 1 is a schematic cross-sectional view of a PTP packaging body using an aluminum foil laminate for PTP packaging according to an embodiment.

The inventors of the present application have studied from the viewpoint of manufacturing a PTP package having a deodorizing function for packaging medicines that emit a peculiar odor. First, when adding a deodorizing function to the container part as disclosed in Patent Document 1, the container part is generally thicker than the lid material and is formed using a large amount of resin, so a large amount of absorbent (adsorbent) can be added. This allows for an excellent deodorizing function to be added to the container part. On the other hand, in the embodiment of Patent Document 1, the thickness of the intermediate layer containing the adsorbent is 60 μm, and further, an adhesive layer for bonding the base layer and the intermediate layer, an outer skin layer, and an inner skin layer for bonding with the lid material are required. For this reason, a large amount of resin must be used to add a deodorizing function to the container part, which causes problems in terms of manufacturing costs and environmental impact.

Next, when adding a deodorizing function to a lid material that is thinner than the container portion, for example, the functional layer disclosed in Patent Document 2 does not have heat-sealing properties. On the other hand, in order to thermally weld the lid material and the container portion, it is necessary to provide a heat-sealing layer that has heat-sealing properties in addition to the functional layer, and in Patent Document 2, the functional layer is formed on a heat-sealing layer provided on the entire surface of the lid material. In addition, the functional layer must be formed in a position that corresponds to the recess of the container portion when it is sealed, and a new positioning process is required to form the functional layer. For this reason, when adding a deodorizing function to a lid material, there is a problem in that the number of manufacturing processes increases compared to conventional methods.

In view of the above problems, we considered the possibility of producing a PTP package with deodorizing function, and came up with the aluminum foil laminate 30 for PTP packaging of the present invention.

The following describes the preferred embodiment in detail with reference to the drawings. The following description of the preferred embodiment is merely exemplary in nature and is not intended to limit the present invention, its applications, or its uses.

Figure 1 shows an aluminum foil laminate 30 for PTP packaging (hereinafter referred to as "aluminum foil laminate") according to an embodiment. Figure 2 shows a PTP packaging body 100 using the aluminum foil laminate 30 according to an embodiment. The aluminum foil laminate 30 according to the embodiment is used as a lid material that is heat-sealed to a container portion 1 that contains contents 2, such as medicines. The PTP packaging body 100 can protect and seal the contents 2 contained in the recess 1a by heat-sealing the container portion 1 and the aluminum foil laminate 30 of the lid material.

The aluminum foil laminate 30 according to the embodiment includes a base material 20 made of aluminum foil and a seal layer 10 laminated on the base material 20. The seal layer 10 can be obtained by applying a seal coating agent containing an inorganic porous body and a heat-sealable resin to the surface of the base material 20.

The inorganic porous body is not particularly limited, and any inorganic compound can be used as long as it has a large number of pores on its surface and has the effect of adsorbing the odorous components, which are the objects to be adsorbed, through these pores. Examples of inorganic porous bodies include zeolite, silicon dioxide, silicates, activated carbon, titania, inorganic phosphates such as calcium phosphate, alumina, aluminum hydroxide, magnesium hydroxide, and mixtures thereof. It is preferable that the inorganic porous body contains one or more of these.

From the viewpoint of safety and obtaining an excellent deodorizing function, the inorganic porous body preferably contains zeolite, aluminum hydroxide, silicate, or silicon dioxide, and more preferably contains zeolite. These inorganic porous bodies have an effective porosity relative to the size of the object to be adsorbed, and therefore can adsorb odorous components.

The inorganic porous body can be selected from those with any average particle size, but from the viewpoint of heat sealing properties and forming a uniform seal layer 10, the average particle size of the inorganic porous body is preferably 0.1 μm or more and 10 μm or less, more preferably 1 μm or more and 3 μm or less. If the average particle size of the inorganic porous body is less than 0.1 μm, the inorganic porous body may aggregate and the uniform dispersion in the seal layer 10 may be suppressed. In addition, if the average particle size of the inorganic porous body is larger than 10 μm, the inorganic porous body may inhibit the formation of a uniform seal layer 10, and the heat sealability of the seal layer 10 may be reduced. As a result, the aluminum foil laminate 30 may not be able to obtain sufficient heat sealing properties, and the protective sealing properties of the contents 2 may be impaired. The average particle size of the inorganic porous body is calculated based on measurements using a laser diffraction particle size distribution device (water dispersion).

The shape of the inorganic porous body is not particularly limited, and may be any shape such as a sphere, a rod, or an ellipse. The form of the inorganic porous body is not particularly limited, and may be, for example, a powder, a lump, or a granule. The form of the inorganic porous body is preferably a powder or a granule from the viewpoints of uniform kneading characteristics with the heat-sealable resin, ease of application of the seal coating agent, ease of formation of the seal layer 10, etc.

The content of inorganic porous material in the sealing layer 10 is preferably 20% by mass or more and 40% by mass or less from the viewpoint of maintaining heat sealability and obtaining excellent deodorizing function. If the content of inorganic porous material in the sealing layer 10 is less than 20% by mass, there is a risk that a sufficient deodorizing effect will not be obtained. On the other hand, if the content of inorganic porous material in the sealing layer 10 is more than 40% by mass, there is a risk that sufficient heat sealability will not be obtained.

Examples of heat-sealable resins include vinyl chloride-vinyl acetate copolymer resins, polyolefin resins, acrylic resins, and polyester resins. The heat-sealable resin preferably contains one or more of these. In addition, from the viewpoint of facilitating thermal welding between the aluminum foil laminate 30 and the container portion 1, the heat-sealable resin is preferably a resin material of the same family as the resin material forming the container portion 1. The heat-sealable resin can be selected from these depending on the resin material of the container portion 1.

The content of the heat sealable resin in the seal layer 10 is preferably 60% by mass or more and 80% by mass or less in order to maintain heat sealability.

The basis weight (mass per unit area) of the seal layer 10 is preferably 2 g/m ² or more and 10 g/m ² or less from the viewpoint of maintaining heat sealability and obtaining excellent deodorizing function. In addition, when the aluminum foil laminate 30 is used as a lid material for the PTP packaging body 100, the basis weight of the seal layer 10 is more preferably 3 g/m ² or more and 7 g/m ² or less from the viewpoint of maintaining the function as a lid material and suppressing costs. From the same viewpoint as above, the thickness of the seal layer 10 is preferably 2 μm or more and 10 μm or less, more preferably 3 μm or more and 7 μm or less. If the basis weight of the seal layer 10 is less than 2 g/m ² , there is a risk that sufficient sealing performance cannot be ensured when the seal layer 10 and the container portion 1 are heat-sealed. On the other hand, if the basis weight of the seal layer 10 is more than 10 g/m ² , the appearance of the seal layer 10 may be impaired.

It is believed that a large amount of adsorbent is necessary to adequately adsorb odorous components generated from the contents 2 sealed in the PTP package 100. For this reason, in Patent Document 1, the middle layer of the absorption layer to which the adsorbent is added is set to a thickness of 60 μm. On the other hand, the thickness of the sealing layer 10 of the lid material is limited to approximately 10 μm in order to reduce costs and ensure clear visibility of the printing on the aluminum foil. For this reason, it was previously believed that it was not possible to add enough adsorbent to the sealing layer 10 to adequately adsorb odorous components.

Furthermore, adding a large amount of adsorbent to the sealing layer 10 reduces the heat sealability to the container portion 1, so adding an adsorbent to the sealing layer 10 has not been considered so far. Instead, as in Patent Document 2, a configuration has been considered in which the adsorbent is provided only in the portion of the lid material facing the recess 1a that contains the contents 2, and only a layer that does not contain an adsorbent and has heat sealability is provided in the other portion that is heat-sealed to the flat portion 1b of the lid material.

The inventors of the present application have questioned this conventional thinking and conducted various studies, finding that only when the content of the inorganic porous body of the adsorbent in the sealing layer 10 and the basis weight of the sealing layer 10 satisfy the above conditions can a sufficient deodorizing effect and a large sealing strength be achieved at the same time, and costs can be reduced. Furthermore, when the above conditions are satisfied, the visibility of the printing applied to the aluminum foil can be sufficiently ensured.

The method of applying the seal coat agent to the surface of the substrate 20 is not particularly limited, but from the viewpoint of workability, for example, gravure coating is preferred. In addition, from the viewpoint of forming a uniform seal layer 10 that maintains heat sealability and has excellent deodorizing function, it is preferable to prepare the seal coat agent using an organic solvent. The seal coat agent can be prepared by dispersing an inorganic porous material in an organic solvent and dissolving a heat sealable resin.

Examples of organic solvents include, but are not limited to, ketone-based organic solvents such as methyl ethyl ketone, acetone, and methyl isobutyl ketone, aromatic hydrocarbon solvents such as toluene, xylene, and benzene, and mixtures thereof. The seal coat agent can also be prepared by dispersing the inorganic porous material directly in the heat-sealable resin, without dispersing the inorganic porous material in the organic solvent beforehand.

The sealing layer 10 can be formed by gravure coating the surface of the substrate 20 with the sealing coating agent and then drying. This makes it possible to obtain an aluminum foil laminate 30 in which the sealing layer 10 is formed on the substrate 20. In addition, with the sealing layer 10 of the aluminum foil laminate 30 and the container portion 1 in contact with each other, the sealing layer 10 and the flat portion 1b of the container portion 1 are thermally welded together by applying heat and pressure from the surface of the substrate 20 opposite to the surface on which the sealing layer 10 is provided. This makes it possible to obtain a PTP package 100 using the aluminum foil laminate 30 as a lid material.

The aluminum foil laminate 30 according to the embodiment of the above configuration can obtain an excellent deodorizing function because the inorganic porous body contained in the sealing layer 10 adsorbs odorous components generated from the contents 2. Furthermore, even though the sealing layer 10 contains an inorganic porous body, it has heat sealing properties, so that an aluminum foil laminate 30 with an excellent deodorizing function can be realized without increasing the number of manufacturing steps compared to the conventional method.

Furthermore, since the aluminum foil laminate 30 according to the embodiment can be heat welded to an existing container part 1, when packaging odor-generating contents 2, it is possible to obtain a PTP package 100 with deodorizing function by simply using the existing container part 1 and equipment and changing the lid material to the aluminum foil laminate 30. This also makes it possible to reduce the cost of manufacturing the PTP package 100 with deodorizing function.

In the above embodiment, the seal layer 10 is provided directly on the substrate 20, but this is not particularly limited, and an optional layer may be interposed between the substrate 20 and the seal layer 10 as necessary. An example of the optional layer is a printed layer. When a printed layer is provided, the seal coating agent that forms the seal layer 10 is transparent, so that the visibility of the printed layer can be ensured. The printing ink used to form the printed layer may be a conventional one.

A printed layer can also be provided on the surface of the substrate 20 opposite the sealing layer 10. When the aluminum foil laminate 30 and the container portion 1 are heat-sealed, heat and pressure are applied from the surface of the substrate 20 opposite the sealing layer 10, so a heat-resistant coating layer can also be provided on the printed layer.

[Evaluation Test 1]
The following aluminum foil laminates were produced in Example 1-1 and Comparative Example 1-1. The configurations of each are also shown in Table 1.

<Example 1-1>
A seal coat agent was prepared by adding 63 parts by mass of vinyl chloride-vinyl acetate copolymer resin and 37 parts by mass of powdered zeolite (average particle size 2 μm) to a mixture of organic solvents methyl ethyl ketone and toluene and stirring. The seal coat agent was gravure coated on the surface of a substrate made of aluminum foil so that the basis weight of the seal layer was 4.5 g/m ² , and then dried. As a result, an aluminum foil laminate having a seal layer formed on the substrate was obtained. This aluminum foil laminate was designated as Example 1-1.

<Comparative Example 1-1>
An aluminum foil laminate was prepared as Comparative Example 1-1 in the same manner as in Example 1-1, except that the seal coating agent did not contain zeolite and was composed only of vinyl chloride-vinyl acetate copolymer resin.

(Test Method)
<Diacetyl reduction rate>
The aluminum foil laminate of Example 1-1 was placed in a sampling bag (Smart Bag PA AF-5, manufactured by GL Sciences), and 3 L of clean air was injected. Thereafter, diacetyl was injected so that the initial concentration was 400 ppm, and the diacetyl concentration was measured at predetermined time intervals. The diacetyl concentration was measured using a gas detector tube (Acetaldehyde No. 92, manufactured by Gastec Corporation). Note that, since the lower measurement limit of the gas detector tube is 25 ppm, diacetyl concentrations of 25 ppm or less (gas detector tube memory 0 to 10) were not measurable.

The diacetyl concentration in the sampling bag immediately after diacetyl injection was set at 100%, and the rate of diacetyl reduction in the sampling bag after leaving it for 24 and 48 hours was confirmed.

The diacetyl reduction rate was confirmed for the aluminum foil laminate of Comparative Example 1-1 in the same manner as for the aluminum foil laminate of Example 1-1.

<Seal strength>
The seal layer in each of the aluminum foil laminates of Example 1-1 and Comparative Example 1-1 was heat-welded to a polyvinyl chloride resin film having a thickness of 200 μm, and the seal strength (N/15 mm) was measured. The welding conditions were a welding temperature of 150° C., a welding time of 1 second, and a welding pressure of 0.29 MPa. It is considered that if the seal strength is 10 N/15 mm or more, the contents are sufficiently protected and sealed.

(Test Results)
The test results are shown in Table 1. According to Table 1, in Example 1-1 containing zeolite, the diacetyl reduction rate after 48 hours was 90% or more, and the odor of diacetyl was not confirmed. It can also be seen that Example 1-1 has the same level of seal strength as Comparative Example 1-1 containing no zeolite.

This shows that the aluminum foil laminate of Example 1-1 has excellent deodorizing function and also maintains the seal strength necessary to protect and seal the contents.

[Evaluation Test 2]
The following aluminum foil laminates were produced in Examples 2-1 to 2-19 and Comparative Examples 2-1 to 2-4. The configurations of each are also shown in Table 2.

<Examples 2-1 to 2-7>
A seal coat agent was prepared by adding 80 parts by mass of vinyl chloride-vinyl acetate copolymer resin and 20 parts by mass of powdered zeolite (average particle size 2 μm) to a mixture of organic solvents methyl ethyl ketone and toluene and stirring. The seal coat agent was gravure coated on the surface of a substrate made of aluminum foil (thickness 20 μm) so that the basis weight of the seal layer was 2.0 g/m ² , and then dried. As a result, an aluminum foil laminate having a seal layer formed on the substrate was obtained. This aluminum foil laminate was designated as Example 2-1.

In addition, Examples 2-2 to 2-7 are aluminum foil laminates obtained in the same manner as in Example 2-1, except that the basis weight of the sealing layer was 3.0 g/m ² , 4.0 g/m ² , 5.0 g/m ² , 6.0 g/m ² , 7.0 g/m ^2, and 10.0 g/m ^2, respectively.

<Examples 2-8 to 2-13>
An aluminum foil laminate obtained in the same manner as in Example 2-1 except that the amount of vinyl chloride-vinyl acetate copolymer resin was 70 parts by mass, the amount of zeolite was 30 parts by mass, and the basis weight of the seal layer was 3.0 g/ ^m2 was selected as Example 2-8.

Examples 2-9 to 2-13 are aluminum foil laminates obtained in the same manner as Example 2-8, except that the basis weights of the sealing layers were 4.0 g/m ² , 5.0 g/m ² , 6.0 g/m ² , 7.0 g/m ² and 10.0 g/m ^{2 ,} respectively.

<Examples 2-14 to 2-19>
An aluminum foil laminate obtained in the same manner as in Example 2-1 except that the amount of vinyl chloride-vinyl acetate copolymer resin was 60 parts by mass, the amount of zeolite was 40 parts by mass, and the basis weight of the seal layer was 3.0 g/ ^m2 was set. Example 2-14.

Examples 2-15 to 2-19 are aluminum foil laminates obtained in the same manner as in Example 2-14, except that the basis weights of the sealing layers were 4.0 g/m ² , 5.0 g/m ² , 6.0 g/m ² , 7.0 g/m ² and 10.0 g/m ^{2 ,} respectively.

<Comparative Example 2-1>
An aluminum foil laminate was prepared as Comparative Example 2-1 in the same manner as in Example 2-1, except that the seal coating agent did not contain zeolite and was composed only of vinyl chloride-vinyl acetate copolymer resin.

<Comparative Example 2-2>
An aluminum foil laminate obtained in the same manner as in Example 2-1 except that the amount of vinyl chloride-vinyl acetate copolymer resin was 90 parts by mass and the amount of zeolite was 10 parts by mass was used as Comparative Example 2-2.

<Comparative Example 2-3>
An aluminum foil laminate obtained in the same manner as in Example 2-1 except that the amount of vinyl chloride-vinyl acetate copolymer resin was 50 parts by mass, the amount of zeolite was 50 parts by mass, and the basis weight of the seal layer was 3.0 g/ ^m2 was used as Comparative Example 2-3.

<Comparative Example 2-4>
An aluminum foil laminate obtained in the same manner as in Example 2-1 except that the amount of vinyl chloride-vinyl acetate copolymer resin was 40 parts by mass, the amount of zeolite was 60 parts by mass, and the basis weight of the seal layer was 5.0 g/ ^m2 was used as Comparative Example 2-4.

(Test Method)
<Deodorizing performance>
Four sheets of the aluminum foil laminate (10 cm square) of Example 2-1 were placed in a vial (capacity 100 ml). Diacetyl (100 ppm) diluted with distilled water was poured therein, and the vial was placed in a thermo-hygrostat and left for 16 hours. Thereafter, the deodorizing performance was confirmed by sensory evaluation.

The deodorizing performance of each of the aluminum foil laminates of Examples 2-2 to 2-19 and Comparative Examples 2-1 to 2-4 was confirmed by sensory evaluation in the same manner as in Example 2-1.

If a significant deodorizing effect was confirmed, it was rated as A, if it was confirmed that the deodorizing effect was sufficient but not significant, it was rated as B, and if no deodorizing effect was confirmed, it was rated as C.

<Sealing performance>
For each of the aluminum foil laminates of Examples 2-1 to 2-19 and Comparative Examples 2-1 to 2-4, the seal strength (N/15 mm) was measured in the same manner as in Test Evaluation 1. If the seal strength was 10 N/15 mm or more, the contents were sufficiently protected and sealed, so that the seal performance was judged to be A, and if it was less than 10 N/15 mm, the contents were not sufficiently protected and sealed, so that the seal performance was judged to be B.

(Test Results)
The test results are shown in Table 2. It is considered that a lid material having a deodorizing function is preferably one whose deodorizing performance is rated as A or B and whose sealing performance is rated as A.

According to Table 2, the deodorizing performance of all of Examples 2-1 to 2-19 was rated as A or B, and the sealing performance was rated as A. Therefore, it can be seen that all of Examples 2-1 to 2-19 have notable or sufficient deodorizing performance, and also have the sealing performance necessary to protect and seal the contents.

Comparative Examples 2-1 and 2-2 were rated as A for sealing performance, but C for deodorizing performance. This shows that when the zeolite content is less than 20% by mass, the product does not have deodorizing performance.

In Comparative Examples 2-3 and 2-4, the deodorizing performance was rated as A, but the sealing performance was rated as B. This shows that when the zeolite content is greater than 40% by mass, the sealing performance required to protect and seal the contents is not present.

From the above evaluation test 2, it is found that by setting the zeolite content in the aluminum foil laminate to 20% by mass to 40% by mass and setting the basis weight of the sealing layer to 2.0 g/m ² to 10.0 g/m ² , it is possible to achieve both excellent deodorizing performance and sealing performance.

1 Container portion 1a Recess 1b Planar portion 2 Contents 10 Seal layer 20 Substrate 30 PTP packaging aluminum foil laminate 100 PTP packaging body

Claims (2)

A PTP packaging aluminum foil laminate comprising a base material made of aluminum foil and a seal layer provided on the base material,
The seal layer contains an inorganic porous material and a heat-sealable resin,
The basis weight of the sealing layer is 2 g/m ² or more and 10 g/m ² or less,
The content of the inorganic porous material in the sealing layer is 20% by mass or more and 40% by mass or less,
The average particle size of the inorganic porous body is 1 μm or more and 3 μm or less . The PTP packaging aluminum foil laminate according to claim 1 , wherein the basis weight of the sealing layer is 3 g/m ² or more and 7 g/m ² or less.

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