JP5976158B1 - Aluminum foil for PTP and method for producing the same - Google Patents

Abstract

An aluminum foil for PTP that prevents the occurrence of cracks in an embossed part without impairing the takeout of the contents and a method for producing the same. An aluminum foil for PTP sealed with a resin film in a press-through package (PTP) is Fe: 0.2 mass% to 1.4 mass%, Cu: 0.01 mass% to 0.10 mass. %, The balance is made of Al and inevitable impurities, and the elongation at 45 ° with respect to the rolling direction is 2.0% or more. [Selection figure] None

Description

  The present invention relates to an aluminum foil for PTP suitable for use in a press-through package or the like and a method for producing the same.

  A press-through package (hereinafter referred to as PTP, which may also be referred to as a blister pack) is a film made of a polypropylene resin or the like formed with a plurality of pockets for storing drugs such as tablets and capsules. By joining aluminum foil to one side, each pocket part is sealed and sealed, and by pushing the back side of the pocket part, the medicine in the pocket part breaks through the aluminum foil and takes out the medicine from the pocket part. Be able to. In this PTP, the periphery of each pocket portion of the film is a flat portion, and the film and the aluminum foil are sealed at the flat portion, and a perforation capable of separating each pocket portion is formed in the seal portion. At the same time, embossing is generally performed in a groove shape.

  In Patent Document 1, as an aluminum foil of such a packaging material for PTP, the yield strength (0.2% yield strength) is 160 MPa or more (more preferably 160 MPa to 180 MPa), and the elongation (breaking elongation) is 1.0% to 2 It is disclosed to produce PTP using 5% hard aluminum foil. It is described that the purity of the aluminum foil is not particularly limited.

JP 2007-253949 A

  By the way, in PTP, an embossed pattern may be provided at the time of sealing as described above for the purpose of securing peel strength or the like. In this embossed portion, cracks may occur in the aluminum foil when the aluminum foil and the film are sealed, when the sheet is punched out by one sheet, or when the aluminum foil is transported in the filling machine after sealing, and defective products may be generated. In order to prevent this crack, if a high strength aluminum foil is used, it is difficult to take out the contents. In order to avoid this, it is necessary to adjust the sealing conditions and the like according to the production lot of the aluminum foil. However, if the adjustment work is performed every time the aluminum foil is switched, the productivity is greatly reduced.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an aluminum foil for PTP that prevents the occurrence of cracks in the embossed portion without impairing the takeout of the contents, and a method for producing the same. And

The aluminum foil for PTP of the present invention contains Fe: 0.2% by mass to 1.4% by mass, Cu: 0.01% by mass to 0.10% by mass, the balance is made of Al and inevitable impurities, and the rolling direction The elongation in the 45 ° direction is 2.0% or more, and is a hard foil .
The PTP of the present invention has a resin film in which a plurality of pocket portions are formed on one side, and the periphery of the pocket portion is formed in a flat portion, and the opening of the pocket portion of the film is closed. The aluminum foil is the aluminum foil for PTP described above.

  The above-described cracks are likely to occur when a groove-like embossed portion is formed along a direction of 45 ° ± 15 ° with respect to the rolling direction. If it is lower than 0%, breakage tends to occur. More preferably, the elongation in the direction of 45 ° with respect to the rolling direction is 2.4% or more.

Fe has the effect of improving the strength and elongation of the aluminum foil by crystallizing Al—Fe intermetallic compounds and the like at the time of casting and dispersing fine compound particles uniformly by rolling. If it is less than 2% by mass, the elongation may be insufficient. In addition, the use of high purity bullion increases costs. If the Fe content exceeds 1.4% by mass, the amount of intermetallic compounds increases and the possibility of pinholes increases. The preferable range of the Fe content is 0.3 mass% to 0.7 mass%, and more preferably 0.3 mass% to 0.55 mass%.
Cu is an element that exists as a solid solution in aluminum. When it is contained in a small amount, Cu lowers the elongation but has the effect of improving the opening of PTP. When the Cu content is less than 0.01% by mass, the unsealing property at the time of use as PTP is lowered, and when it exceeds 0.10% by mass, the elongation is lowered and cracks are easily generated during rolling. And intermediate annealing must be added, which reduces productivity. A more preferable range of the Cu content is 0.015% by mass to 0.05% by mass.

  In the method for producing an aluminum foil for PTP of the present invention, after hot rolling an aluminum ingot, at least one intermediate annealing and final cold rolling are performed in this order in the course of cold rolling and cold rolling. In which the rolling reduction rate until the first intermediate annealing in the cold rolling is 75% or more.

  By performing at least one intermediate annealing at the time of cold rolling, strain hardening due to cold rolling is removed, deformation resistance of the material is reduced, and subsequent cold rolling is facilitated. In this case, if the reduction ratio until the first intermediate annealing is less than 75%, the rolling texture is not sufficiently developed, and the elongation in the direction of 45 ° with respect to the rolling direction cannot be sufficiently increased. A preferable range of the rolling reduction until the first intermediate annealing is 85% or more. Further, the preferred number of intermediate annealing is one, and when the number of intermediate annealing is increased, the cost is increased and the productivity is lowered.

  According to the aluminum foil for PTP of the present invention, it is possible to prevent the occurrence of cracks at the embossed portion without impairing the takeout of the contents.

It is a perspective view which shows the example of PTP to which the aluminum foil for PTP of this invention is applied. It is a longitudinal cross-sectional view of a part of FIG.

Hereinafter, embodiments of the aluminum foil for PTP of the present invention will be described in detail.
The PTP will be described. As shown in FIGS. 1 and 2, the PTP 1 is composed of a film 2 made of resin such as polypropylene, polyethylene terephthalate, polyvinyl chloride, polystyrene, and the aluminum foil 3. The film 2 is formed with a plurality of pocket portions 4 opened on one side thereof by vacuum forming or the like, and the periphery of each pocket portion 4 is formed in a flat portion 5. The aluminum foil 3 is closed on the flat portion 5 of the film 2 by closing the opening of the pocket portion 4 of the film 2 and is sealed to the flat portion 5 by thermal bonding or the like.

Further, the seal portion 6 is formed with perforations 7 capable of separating the pocket portions 4 individually or plurally, and is formed with an embossed groove 8. The perforation 7 is formed with a row of slits penetrating the front and back. The embossed groove 8 is formed by a set of rolls (not shown) used when the film 2 and the aluminum foil 3 are thermally bonded. One of these rolls is an embossing roll having ridges formed on the surface, and a laminate of the film 2 and the aluminum foil 3 is passed between these rolls, and the embossing ridges of the embossing roll finely seal them while sealing them. A groove 8 is formed. The grooves 8 are formed in a stripe shape, a lattice shape, a mesh shape, or the like.
Then, a medicine 9 such as a tablet or a capsule is stored in the pocket portion 4.

Next, the aluminum foil 3 for PTP will be described.
This aluminum foil contains Fe: 0.2 mass% to 1.4 mass%, Cu: 0.01 mass% to 0.10 mass%, the balance is made of Al and inevitable impurities, and the thickness is 10 μm to 30 μm. The elongation in the direction of 45 ° with respect to the rolling direction is 2.0% or more.

  Fe has the effect of improving the strength and elongation of the aluminum foil by crystallizing Al—Fe intermetallic compounds and the like at the time of casting and dispersing fine compound particles uniformly by rolling. If it is less than 2% by mass, the elongation may be insufficient. In addition, the use of high purity bullion increases costs. If the Fe content exceeds 1.4% by mass, the amount of intermetallic compounds increases and the possibility of pinholes increases. The preferable range of the Fe content is 0.3 mass% to 0.7 mass%, and more preferably 0.3 mass% to 0.55 mass%.

  Cu is an element that exists as a solid solution in aluminum. When it is contained in a small amount, Cu lowers the elongation, but has the effect of improving the opening of PTP. When the Cu content is less than 0.01% by mass, the unsealing property at the time of use as PTP is lowered, and when it exceeds 0.10% by mass, the elongation is lowered and cracks are easily generated during rolling. And intermediate annealing must be added, which reduces productivity. A more preferable range of the Cu content is 0.015% by mass to 0.05% by mass.

In addition, although the thickness of the aluminum foil for PTP of this invention is not specifically limited, In order to exhibit the function as PTP, it is preferable that they are 10 micrometers or more and 30 micrometers or less. If the thickness is less than 10 μm, pinholes exist, moisture permeability increases and the contents cannot be protected, and the possibility of tearing during transportation and handling increases. If the thickness exceeds 30 μm, the force for taking out the contents will increase, making it difficult for elderly people and children to open. The thickness is more preferably 15 μm to 25 μm, and further preferably 17 μm to 22 μm.
Cracks generated in the aluminum foil of PTP are likely to occur when groove-shaped embossed portions are formed along the direction of 45 ° ± 15 ° with respect to the rolling direction. If the elongation is lower than 2.0%, breakage tends to occur. If the elongation in the 45 ° direction with respect to the rolling direction is 2.0% or more, the elongation in the rolling direction may be smaller than 2.0%. On the other hand, even if the elongation in the rolling direction is 2.0% or more, the occurrence of cracks cannot be suppressed if the elongation in the direction of 45 ° with respect to the rolling direction is less than 2.0%. More preferably, the elongation in the direction of 45 ° with respect to the rolling direction is 2.4% or more.

Next, a method for manufacturing the aluminum foil for PTP having such a configuration will be described.
(Casting process)
First, from a molten aluminum containing Fe: 0.2 mass% to 1.4 mass%, Cu: 0.01 mass% to 0.10 mass%, and the balance being composed of Al and inevitable impurities, An aluminum ingot is formed by casting using a casting method.

(Homogenization process)
Next, after chamfering the aluminum ingot, homogenization is performed for the purpose of making the structure of the aluminum ingot uniform. For example, the aluminum ingot is heated to 450 ° C. to 620 ° C. and held for 1 to 12 hours to perform a homogenization treatment.

(Rolling process)
The aluminum ingot after the homogenization treatment step is hot-rolled to produce 2 mm to 10 mm hot rolled sheets. The hot rolling may be carried out following the homogenization treatment, or after the homogenization treatment, once cooled to room temperature and then heated again.
Subsequently, in the course of cold rolling and cold rolling, intermediate annealing and final final cold rolling are performed in this order to produce a foil. The temperature of hot rolling and cold rolling is not particularly limited, and may be according to a conventional method.

In cold rolling, rolling is performed so that the rolling reduction until the subsequent intermediate annealing is 75% or more. When intermediate annealing is performed a plurality of times during cold rolling, the rolling reduction until the first intermediate annealing is set to 75% or more. When the rolling reduction rate until the first intermediate annealing is less than 75%, the rolling texture is not sufficiently developed, and the elongation in the direction of 45 ° with respect to the rolling direction cannot be sufficiently increased.
It is set as the aluminum sheet of thickness 0.3mm-1.0mm by the cold rolling to this intermediate annealing.

Next, intermediate annealing is maintained at 280 ° C. to 400 ° C. for 1 hour to 12 hours, thereby removing strain hardening due to cold rolling, reducing the deformation resistance of the material, and subsequent cold rolling and final cold rolling. To make it easier. This intermediate annealing can be performed by a conventional method. As described above, cold rolling may be performed while performing the intermediate annealing a plurality of times.
In the final cold rolling, superposition rolling is performed in which two aluminum sheets are stacked and rolled. One rolling reduction is set to 30% to 60%, and an aluminum foil having a thickness of 10 μm to 30 μm is obtained. Finish annealing after the final cold rolling is not performed.

  In the aluminum foil manufactured in this way, when it is thermally bonded to the film to form PTP, it is pressed against the protrusions of the embossing roll, but the elongation in the direction of 45 ° with respect to the rolling direction is 2 Since it is 0.0% or more, it is difficult to break at the embossed part, and since it is 10 μm to 30 μm thick, it has excellent oxygen and humidity barrier properties and can protect the drug in the pocket part from the external environment. It can be done without inconvenience such as inadvertent tearing during transportation and handling. Moreover, the aluminum foil can be easily broken at the time of opening by a normal take-out operation.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made to the above-described embodiment without departing from the spirit of the present invention.

Next, the result of an experiment conducted for confirming the effect of the aluminum foil for PTP of the present invention will be described.
As shown in Table 1, an aluminum ingot having a thickness of 500 mm was produced by casting from a molten aluminum in which each component of Fe and Cu was adjusted. The balance consists of Al and inevitable impurities.
And after chamfering the surface of this aluminum ingot, it homogenized for 5 hours at 550 degreeC, and it was set as the aluminum sheet by hot rolling. Next, cold rolling was performed, intermediate annealing was performed in the middle, and two aluminum sheets were polymerized and rolled by final cold rolling to obtain an aluminum foil. At this time, the sheet thickness t1 after the end of the hot rolling and the sheet thickness t2 before the first intermediate annealing after the cold rolling are measured, respectively, and the reduction ratio until the intermediate annealing ((t1-t2) / t1) %) Was calculated.
The thickness of the final aluminum foil was 20 μm in both examples and comparative examples. In order to investigate the influence of the thickness of the foil, samples of 8 μm and 35 μm were also prepared in the components of Example 2, but pinholes were generated in the 8 μm thick foil, and it could not be used as an aluminum foil for PTP. It was. Also, a 35 μm thick foil was unusable because its opening resistance was too large when used as PTP, and the opening performance was significantly impaired.

About each sample of the obtained aluminum foil, the elongation in the direction of 45 ° with respect to the rolling direction and the rolling direction and the presence or absence of cracks were measured and evaluated. In Comparative Example 4, since pinholes were generated, it was not suitable as an aluminum foil for PTP, so these measurements were not performed.
The elongation was measured by preparing a No. 5 test piece according to JIS Z2241, and performing a tensile test on the test piece of each sample at room temperature.
The presence or absence of cracks was determined by visual observation of the result of thermal bonding of a laminate of an aluminum foil having a size of 100 mm × 200 mm and a polyvinyl chloride film having a thickness of 0.5 mm through an embossing roll heated to 250 ° C. Confirm that no cracks were observed at all, “No”, 0.5 mm or less cracks were recognized in the range of 2 or less “Slight”, 0.5 mm or less cracks 3 or more or cracks A sample having a size exceeding 0.5 mm was defined as “many”. A “slight” evaluation in this standard is recognized as an acceptable range for use as a product.
These results are shown in Table 1.

As is clear from Table 1, in the samples of Examples 1 to 7 according to the present invention, there was no occurrence of cracks, or a slight amount that was within an allowable range.
In Comparative Example 1, the Fe content was as low as 0.05% by mass, and in Comparative Example 2 the Cu content was as high as 0.32% by mass, so the elongation was small and cracks increased. In Comparative Example 3, the rolling reduction until the intermediate annealing during the cold rolling was as small as 50%, so the elongation in the rolling direction was large, but the elongation in the direction of 45 ° with respect to the rolling direction was small, and many cracks were generated. It was. As can be seen from the results of each example, in order to suppress the occurrence of cracks, it is necessary that the elongation in the 45 ° direction relative to the rolling direction is 2.0% or more than the elongation in the rolling direction. In all examples, the elongation in the rolling direction was 1.5% or more.
In Comparative Example 4, since the Fe content was as high as 1.70% by mass, pinholes were generated.

1 PTP
2 Film 3 Aluminum foil 4 Pocket portion 5 Plane portion 6 Seal portion 7 Perforation 8 Groove 9 Drug

Claims (3)

Fe: 0.2% by mass to 1.4% by mass, Cu: 0.01% by mass to 0.10% by mass, the balance is made of Al and inevitable impurities, and the elongation in the direction of 45 ° with respect to the rolling direction. Is an aluminum foil for PTP, characterized by being a hard foil. A method for producing the aluminum foil for PTP according to claim 1,
After hot rolling an aluminum ingot, cold rolling, a method of producing an aluminum foil for PTP by performing at least one intermediate annealing and final cold rolling in this order in the middle of cold rolling,
A method for producing an aluminum foil for PTP, wherein the rolling reduction until the first intermediate annealing in the cold rolling is 75% or more.   A resin film having a plurality of pocket portions formed on one side, the periphery of the pocket portion being formed in a flat portion, and an aluminum foil sealed with the flat portion by closing the opening of the pocket portion of the film And the aluminum foil is the aluminum foil for PTP according to claim 1.

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