JP2023113473A - PTP sheet and molding - Google Patents

Abstract

To provide a PTP sheet having moderate flexibility and excellent formability and a molded body including the same.SOLUTION: The PTP sheet includes polypropylene resin. The thickness is 200 to 400 μm. The tensile stress imposed at 150% elongation (150% tensile stress) is 1.8 to 3.0 MPa when tested at 125°C in a tensile test. The crystal melting calorie as determined by differential scanning calorimetry (DSC) is 63.0 to 80.0 J/g.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a PTP (Press Through Pack) sheet and a molded article containing the PTP sheet.

BACKGROUND ART A PTP package including a bottom material and a lid material is known as one form of packaging for pharmaceuticals, food, and the like. A PTP package is manufactured by filling contents into a pocket-shaped recess formed in a bottom material, and then heat-sealing a cover material to a flange portion other than the recess. The stored contents can be taken out by applying force to the contents from the outside of the bottom member in the direction of the lid member to break through the lid member.

As the bottom material, conventionally, a plastic sheet containing a polyvinyl chloride resin has often been used. In recent years, however, polyvinyl chloride resin sheets are being avoided due to the environmental problem of generating chlorine gas when incinerated, and polypropylene resin has been used as an alternative resin. For example, Patent Documents 1 to 7 disclose PTP lid materials containing polypropylene-based resins.

On the other hand, as the lid material, conventionally, aluminum foil, glassine paper, or the like has been used, which is excellent in that it can be easily broken by pushing out the contents. However, in recent years, due to the trend of reducing single-use plastic products, implementing recycling, and switching to renewable resources, not only the bottom material but also the plastic sheet containing polypropylene resin etc. is used for the lid material. There is no need for sorting in the case of recycling, and an environmentally friendly PTP package that can be recycled has attracted attention.

JP-A-11-129417 JP-A-9-314770 JP-A-10-329865 JP-A-9-215726 Japanese Patent No. 3919365 JP-A-2005-263287 JP-A-2004-67929

However, the polypropylene resin sheet has a problem that it is inferior to the polyvinyl chloride resin sheet in moldability. Specifically, the molding temperature range is narrower and higher than that of a polyvinyl chloride sheet. Various attempts have been made to improve moldability, but it is difficult to balance the rigidity of the sheet at room temperature, and the rigidity at room temperature is so high that it damages the esophageal wall during accidental ingestion. There is also the danger of

Accordingly, an object of the present invention is to provide a PTP sheet having appropriate flexibility and excellent moldability, and a molded article containing the PTP sheet.

As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by making a sheet containing a polypropylene resin and having a thickness within a specific range, a 150% tensile stress, and a heat of crystal fusion. can be solved, and the present invention has been completed.

That is, the present invention is as follows.
[1]
including polypropylene resin,
The thickness is 200 to 400 μm,
When a tensile test is performed at 125 ° C., the tensile stress at 150% elongation (150% tensile stress) is 1.8 to 3.0 MPa,
A PTP sheet characterized by having a heat of crystal fusion of 63.0 to 80.0 J/g measured by a differential scanning calorimeter (DSC).
[2]
The PTP sheet according to [1], which is composed of at least two layers, one of which is a heat-sealing layer, and the static friction coefficient of the sealing surface of the heat-sealing layer is 0.7 or less.
[3]
The PTP sheet according to [2], wherein the sealing strength is 8 N/15 mm or more when a polypropylene film having a thickness of 20 to 40 μm is heat-sealed at 100° C. to the sealing surface of the heat-sealing layer.
[4]
The PTP sheet according to any one of [1] to [3], wherein the upper yield point does not exist or, if it exists, it is 3 MPa or less when a tensile test is performed at 125°C.
[5]
The PTP sheet according to any one of [2] to [4], wherein the heat seal layer contains a polyolefin thermoplastic elastomer.
[6]
including the PTP sheet according to any one of [1] to [5],
A molded product, wherein the PTP sheet has an indentation load of 15 to 21N.

According to the present invention, it is possible to provide a PTP sheet having appropriate flexibility and excellent moldability, and a molded article containing the PTP sheet.

FIG. 1 is a plan view showing the shape of a test piece used in a high-temperature tensile test in Examples.

Hereinafter, the mode for carrying out the present invention (hereinafter referred to as "the present embodiment") will be described in detail, but the present invention is not limited to the following description, and various It can be modified and implemented.

<PTP sheet>
The PTP sheet of this embodiment contains a polypropylene-based resin.
The polypropylene resin content in 100% by mass of the PTP sheet is preferably 70% by mass or more, more preferably 90% by mass or more, and particularly preferably 100% by mass. When the content of the polypropylene-based resin is within the above range, it tends to be possible to recycle the material without degrading the physical properties of polypropylene when recycling the ends discharged during the production process and the waste after use. be. For example, even after re-kneading for reuse, transparency tends to be maintained and recyclability tends to be good.

〈〈Polypropylene resin〉〉
The polypropylene-based resin contained in the PTP sheet is not particularly limited, and examples thereof include propylene homopolymers, copolymers of propylene and other monomers, modified products thereof, and the like. Bio-polypropylene may also be used from the viewpoint of environmental friendliness.

Examples of monomers copolymerizable with propylene include α-olefins such as ethylene, 1-butene, isobutylene, 1-pentene and 1-hexene. The form of polymerization is not particularly limited, and may be a random copolymer, a block copolymer, or the like.

The method for producing the polypropylene-based resin is not particularly limited, and known methods such as a method of polymerizing propylene or other monomers in the presence of a catalyst can be used. Specifically, for example, there is a method of polymerizing propylene or other monomers in the presence of a catalyst and an alkylaluminum compound at a polymerization temperature of 0 to 100° C. and a polymerization pressure of 3 to 100 atm.
Examples of the catalyst include a titanium trichloride catalyst and a titanium halide catalyst supported on a carrier such as magnesium chloride. A chain transfer agent such as hydrogen may be added to adjust the molecular weight of the polymer.

In the production of polypropylene-based resin, in addition to the above catalyst, an electron-donating compound can be used as a third component as an internal donor component or an external donor component in order to increase the isotacticity and polymerization activity of polypropylene. The electron-donating compound is not particularly limited, and known compounds can be used. Examples include ester compounds such as ε-caprolactone, methyl methacrylate, ethyl benzoate, and methyl toluate; Phosphites such as tributyl; Phosphoric acid derivatives such as hexamethylphosphoric triamide; Alkoxy ester compounds; Aromatic monocarboxylic acid esters; Aromatic alkylalkoxysilanes; Aliphatic hydrocarbon alkoxysilanes; class; various phenols and the like.

The polymerization system in the above method may be either a batch system or a continuous system. The polymerization method includes solution polymerization in a solvent such as butane, pentane, hexane, heptane, octane, etc., slurry polymerization, bulk polymerization in a monomer in the absence of solvent, gas phase polymerization in a gaseous monomer, and the like. .

The polypropylene-based resin may be obtained by modifying an unmodified polypropylene-based resin with a modifying agent such as α,β-unsaturated carboxylic acid or its derivative (including acid anhydride and ester). Modified polypropylene resins include, for example, those obtained by grafting or adding an α,β-unsaturated carboxylic acid or a derivative thereof to an unmodified polypropylene resin. Specific examples include α,β-unsaturated carboxylic acid or a derivative thereof grafted or added to a polypropylene-based resin at a rate of about 0.01 to 10% by mass based on the total polypropylene-based resin. .
The modified polypropylene resin is, for example, in the presence or absence of a radical generator, in a molten state, in a solution state, or in a slurry state, in the range of 30 to 350 ° C., reacting an unmodified polypropylene resin and a modifier. obtained by letting

When the polypropylene-based resin is a mixture of unmodified polypropylene and modified polypropylene, the mixing ratio of the unmodified polypropylene and modified polypropylene is not particularly limited, and may be any ratio.

Polypropylene-based resins may be used alone or in combination of two or more. A mixture of a homopolymer (H-PP) and a propylene random copolymer (R-PP) is preferred.
By including propylene homopolymer, for example, when a PTP sheet is molded into a PTP bottom material, it tends to be possible to suppress the sheet from stretching and deforming, and also has sufficient rigidity to protect the contents. tend to be able to express In addition, by containing a propylene random copolymer, moldability at low temperatures (110 to 140° C., etc.) tends to be better than when only a propylene homopolymer is used.
Suitable propylene homopolymers and propylene random copolymers are further described below.

The propylene homopolymer has a tensile stress of 3.8 to 5.8 MPa at 150% elongation (150% tensile stress) when a tensile test is performed using a propylene homopolymer sheet at 125°C. It is preferably 3.9 to 5.6 MPa, more preferably 4.0 to 5.5 MPa. When the 150% tensile stress is within the above range, molding tends to be easy even at low temperatures (110 to 140° C., etc.).

In addition, the propylene homopolymer preferably has an upper yield point of 150% tensile stress + 0 to 2 MPa, more preferably 150% tensile strength when a tensile test is performed at 125 ° C. using a propylene homopolymer sheet. The stress is +0 to 1 MPa. When the difference between the upper yield point and the 150% tensile stress is +0 to 2 MPa, the range of molding temperature is widened, and the moldability tends to be excellent.

Further, the propylene homopolymer preferably has a tensile modulus of 650 to 850 MPa, more preferably 650 to 820 MPa, still more preferably 650 to 850 MPa, when a tensile test is performed using a propylene homopolymer sheet at room temperature. 800 MPa. When the tensile modulus is 650 MPa or more, the PTP sheet has an appropriate rigidity and tends to suppress deformation due to elongation of the sheet during sheet molding. It has moderate flexibility and tends to reduce the risk of damage to the esophageal wall when a fragment of the PTP sheet is accidentally swallowed.
Methods for controlling the tensile modulus of a propylene homopolymer sheet include, for example, a method of adjusting the heat of crystal fusion of the sheet, and when the heat of crystal fusion is reduced, the tensile modulus tends to decrease.

The propylene random copolymer has a tensile stress at 150% elongation (150% tensile stress) of 0.1 to 0.8 MPa when a tensile test is performed at 125°C using a propylene random copolymer sheet. is preferred, more preferably 0.2 to 0.8 MPa, still more preferably 0.3 to 0.7 MPa. When the 150% tensile stress is 0.1 MPa or more, the PTP sheet has an appropriate rigidity, and the sheet tends to be restrained from being stretched and deformed during molding, and when it is 0.8 MPa or less. , molding at low temperatures (110 to 140° C., etc.) tends to be good.

Specifically, the tensile test at 125° C. can be measured by the method described in Examples below.
Moreover, the tensile test at room temperature is carried out in accordance with JIS K7127, and specifically, it can be measured by the method described in Examples below.

The melt flow rate (MFR) of the propylene homopolymer is preferably 1.0 to 15 g/10 minutes, more preferably 1.5 to 12 g/10 minutes, still more preferably 2 to 10 g/10 minutes. If the MFR is within the above range, if the MFR is less than 1.0, extrusion molding becomes difficult, and if it is 15 or more, cracks are likely to occur during processing of the PTP sheet.
Further, the melt flow rate (MFR) of the propylene random copolymer is preferably 0.8 to 15 g/10 minutes, more preferably 1 to 12 g/10 minutes, still more preferably 1.5 to 10 g/10 minutes. be. If the MFR is within the above range, if the MFR is 0.4 or less, extrusion molding becomes difficult, and if it is 15 or more, cracks are likely to occur during processing of the PTP sheet.
The MFR can be measured at 230° C. under a load of 2.16 kgf according to JIS K 7210.

The blending weight ratio (H-PP:R-PP) of the propylene homopolymer and the propylene random copolymer is preferably 40:60 to 60:40, more preferably 45:55 to 55:45, still more preferably 42.5:57.5 to 57.5:42.5. When the blending mass ratio is within the above range, the PTP sheet tends to have appropriate flexibility and rigidity and excellent moldability.

The PTP sheet of the present embodiment may be a laminate composed of at least two layers, for example, a laminate including a substrate layer and a heat seal layer.
Layers other than the base material layer and the heat seal layer include, for example, an adjustment layer for adjusting physical properties of the PTP sheet such as strength, and a barrier layer for improving gas barrier properties.
Although the number of layers to be laminated is not particularly limited, it is preferably 2 to 5 layers, more preferably 2 to 3 layers, from the viewpoint of the balance of flexibility, sealability and recyclability.

<<Base material layer>>
The base material layer is not particularly limited as long as it contains a polypropylene-based resin, and examples of the polypropylene-based resin include the above-described ones, and they may be used singly or in combination of two or more. From the viewpoint of moldability and flexibility, the polypropylene-based resin contained in the substrate layer is preferably a mixture of the above propylene homopolymer and propylene random copolymer.
The polypropylene-based resin content in 100% by mass of the base material layer can be recycled without degrading the physical properties of polypropylene when recycling the edges discharged during the production process or waste after use. For example, even after re-kneading for reuse, transparency tends to be maintained and recyclability tends to be good, so it is preferably 90% by mass or more, more preferably 95% by mass or more. and particularly preferably 100% by mass.

The thickness of the base material layer is preferably 225-315 μm, more preferably 235-285 μm, still more preferably 240-270 μm. If the thickness is less than 225 μm, the sheet will be too soft and the protective properties of the tablet will tend to decrease.

〈〈Heat seal layer〉〉
The heat seal layer is a layer that forms the sealing surface of the PTP sheet (for example, the surface that adheres to the PTP lid material when the PTP sheet is formed into the PTP bottom material).
The heat seal layer is not particularly limited as long as it contains a polypropylene-based resin, and examples of the polypropylene-based resin include the above-described ones, and one type alone or a combination of two or more types may be used.
The content of the polypropylene resin in 100% by mass of the heat seal layer is 40 to 90% by mass, because transparency tends to be maintained even after re-kneading for reuse and recyclability tends to be good. is preferably 45 to 75% by mass, and more preferably 50 to 60% by mass.

The heat-sealing layer preferably contains a polyolefin-based thermoplastic elastomer from the viewpoint of exhibiting excellent heat-sealing properties.
A polyolefin thermoplastic elastomer is a low-crystalline or amorphous olefin polymer having a degree of crystallinity of 50% or less. -butene, isobutylene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-butene, 2-methyl-1-butene, 1-hexene, 1-octene, 1-decene, 1 -α-olefins such as dodecene, and cyclic olefins such as cyclobutene, cyclopentene and cyclohexene.
Among them, polypropylene-based elastomers having a low melting point (55 to 90°C) are preferable because they are excellent in heat-sealing properties at low temperatures (100 to 140°C, etc.). Moreover, from the viewpoint of environmental friendliness, a biopolyolefin thermoplastic elastomer may be used.
Polyolefin-based thermoplastic elastomers may be used alone or in combination of two or more.

The method for producing the polyolefin-based thermoplastic elastomer is not particularly limited, and polymerization can be performed using known catalysts such as single-site catalysts and multi-site catalysts.

The content of the polyolefin thermoplastic elastomer in 100% by mass of the heat seal layer is 10 to 60 because transparency tends to be maintained even after re-kneading for reuse and recyclability tends to be good. % by mass, more preferably 20 to 55% by mass, and even more preferably 30 to 50% by mass.

The heat seal layer preferably has a static friction coefficient of 0.7 or less, more preferably 0.6 or less, and still more preferably 0.55 or less on the sealing surface. If the coefficient of static friction of the sealing surface is 0.7 or less, for example, when a PTP sheet is used as a PTP bottom material for a PTP lid material made of polypropylene resin, and a PTP package is formed, the lid material is wrinkled. It tends to be able to be molded without bending. The lower limit of the coefficient of static friction of the sealing surface is not particularly limited. From the viewpoint of preventing the lid from slipping, it is preferably 0.01 or more, more preferably 0.03 or more, and still more preferably 0.05 or more.
Specifically, the coefficient of static friction of the sealing surface of the heat seal layer can be measured by the method described in Examples below.

The PTP sheet preferably has a sealing strength of 8 N/15 mm or more, more preferably 8.5 N, when a polypropylene film having a thickness of 20 to 40 μm is heat-sealed at 100° C. to the sealing surface of the heat-sealing layer. /15 mm or more, more preferably 9.0 N/15 mm or more. When the seal strength is 8 N / 15 mm or more, the temperature at the time of heat sealing is excellent for polypropylene film etc. (100 to 140 ° C.) which is lower than that for aluminum foil etc. (160 to 200 ° C.). It can be suitably used as a PTP bottom material for a PTP lid material made of a base resin. Although the upper limit of the seal strength is not particularly limited, it is preferably 30 N/15 mm or less, more preferably 20 N/15 mm or less, and even more preferably 18 N/15 mm or less.
The seal strength can be specifically measured by the method described in Examples below.

The thickness of the heat seal layer is preferably 20-75 μm, more preferably 20-70 μm, and still more preferably 30-60 μm. When the thickness is 20 μm or more, for example, when used as a PTP bottom material for a PTP lid material made of polypropylene resin, the sealing property with the lid material is easily exhibited, and when the thickness is 75 μm or less, the PTP sheet It tends to be a PTP sheet that is easy to mold.

The PTP sheet of the present embodiment contains additives commonly used in the art, such as inorganic fillers, metal soaps that assist dispersion of inorganic fillers, colorants, plasticizers, antioxidants, heat stabilizers, It may contain ultraviolet absorbers, lubricants, antistatic agents, crystal nucleating agents, and the like.
The content of the additive is not particularly limited as long as it does not impair the effects of the present invention. It is particularly preferred not to contain

When the PTP sheet is printed on its surface, it may be subjected to corona treatment, plasma treatment, ultraviolet treatment, AC (anchor coat) treatment, or the like for the purpose of improving printing characteristics.

The thickness of the PTP sheet as a whole is 200-400 μm, preferably 250-350 μm, more preferably 250-300 μm. When the thickness is less than 200 μm, the sheet tends to be thin and the tablet protective property tends to be deteriorated, and when it exceeds 400 μm, the ejection property of the tablet tends to be deteriorated and the processability during molding tends to deteriorate.

The PTP sheet has a tensile stress at 150% elongation (150% tensile stress) of 1.8 to 3.0 MPa, preferably 1.9 to 3.0 MPa, when subjected to a tensile test at 125 ° C. More preferably 2.0 to 2.9 MPa. When the 150% tensile stress is 1.8 MPa or more, the sheet tends to be excessively flexible and the upper limit of the molding temperature can be suppressed from becoming too low, and as a result, the sheet tends to stretch and deform during molding. can be suppressed. Further, when the 150% tensile stress is 3.0 MPa or less, there is a tendency that the pocket can be molded with good conformability to the molding die.
As a method for controlling the 150% tensile stress of the PTP sheet, for example, a method of using a mixture of a propylene homopolymer and a propylene random copolymer and adjusting the blending ratio thereof can be mentioned. , the 150% tensile stress tends to increase.

The PTP sheet preferably does not have an upper yield point when subjected to a tensile test at 125° C., or if it does, has an upper yield point of 3 MPa or less. If the upper yield point does not exist, or if it exists, it is 3 MPa or less, it has a moderate tensile modulus, and for example, when molded into a PTP bottom material having a recess, the recess has a perfect shape. tends to be obtained. If there is an upper yield point, it is more preferably 2.9 MPa or less, still more preferably 2.8 MPa or less, and the lower limit is not particularly limited. It is preferably 8 MPa or more, more preferably 2.0 MPa or more.
As a method for controlling the upper yield point of the PTP sheet, for example, a method of using a mixture of a propylene homopolymer and a propylene random copolymer and adjusting the blending ratio thereof can be mentioned. The yield point tends to increase.
The upper yield point means the point at which the stress shows the maximum value in the elastic deformation region of the stress-strain curve (the region from the start of the test until the stress first begins to decrease).

The PTP sheet preferably has an MD tensile modulus of 400 to 600 MPa, more preferably 425 to 575 MPa, and still more preferably 450 to 550 MPa when subjected to a tensile test at room temperature. When the MD tensile modulus exceeds 600 MPa, the sheet tends to be too hard, and there is a tendency to increase the risk of damaging the esophageal wall when a piece of the PTP sheet is accidentally swallowed. On the other hand, when the MD tensile modulus is less than 400 MP, the rigidity at room temperature tends to be insufficient, and the workability during molding tends to deteriorate.
Methods for controlling the MD tensile modulus of the PTP sheet include, for example, a method of adjusting the heat of crystal fusion and the degree of MD orientation of the PTP sheet. is trending downward.
In addition, MD means the flow direction of the sheet|seat at the time of sheet|seat manufacture for PTP.

The PTP sheet preferably has a TD tensile modulus of 400 to 600 MPa, more preferably 425 to 575 MPa, and still more preferably 450 to 550 MPa when subjected to a tensile test at room temperature. If the TD tensile modulus exceeds 600 MPa, the sheet tends to be too hard and there is a tendency to increase the risk of damaging the esophageal wall when a piece of the PTP sheet is swallowed. Further, when the TD tensile modulus is less than 400 MPa, the rigidity at room temperature tends to be insufficient, and the workability during molding tends to deteriorate.
As a method for controlling the TD tensile elastic modulus of the PTP sheet, for example, there is a method of adjusting the heat of crystal fusion and the degree of TD orientation of the PTP sheet. is trending downward.
Note that TD means a direction perpendicular to MD.

The tensile test at normal temperature is carried out in accordance with JIS K7127, and specifically, it can be measured by the method described in Examples below.

The PTP sheet has a heat of crystal fusion measured by a differential scanning calorimeter (DSC) of 63.0 to 80.0 J/g, preferably 64.0 to 75.0 J/g, more preferably 64.0 J/g. 0 to 73.0 J/g. When the heat of crystal fusion is within the above range, the MD tensile modulus and the TD tensile modulus tend to fall within the preferred ranges, and moderate flexibility and rigidity tend to be obtained.
Methods for controlling the heat of crystal fusion of the PTP sheet include, for example, a method of adjusting the cooling rate of the sheet when producing the PTP sheet, annealing after production, addition of a crystal nucleating agent, and the like. As an example, the amount of heat of crystal fusion can be increased by slowing cooling when manufacturing a PTP sheet by a direct inflation method, annealing the sheet after manufacturing, adding a crystal nucleating agent, or the like.
The heat of crystal fusion can be specifically measured by a differential scanning calorimeter (DSC) by the method described in Examples below.

From the viewpoint of moldability, the PTP sheet has a depth of 4 mm, an opening portion of 10 mm in diameter, and a bottom portion of 8 mm in diameter. It is preferably 10°C or higher, more preferably 12°C or higher, and still more preferably 13°C or higher.
The molding temperature refers to a temperature range in which the recesses are completely molded, and can be specifically measured by the method described in Examples below.

Since the PTP sheet of the present embodiment has moderate flexibility and excellent moldability, it is preferably used as a molding material for a PTP bottom material, and is particularly excellent in heat sealability at low temperatures. From the viewpoint of recyclability, it is preferable to use it as a molding material for the PTP bottom material for the PTP lid material made of polypropylene resin.

<Method for manufacturing PTP sheet>
The method for producing the PTP sheet is not particularly limited, but since the cooling rate is relatively slow and the heat of crystal melting can be increased, a direct inflation method (using a known melt extruder equipped with an annular die to extract raw materials) is used. A method of extruding into a tubular shape and then directly blowing in air for stretching) is preferable. When the PTP sheet is a laminate comprising a plurality of layers, it is preferable to use a co-extrusion direct inflation method.
The outline of a method for producing a PTP sheet, which is a laminate, by a co-extrusion direct inflation method will be described below.

A resin or a resin composition, which is a constituent material of each layer, is melted at a melting temperature of the resin or higher, and each layer is simultaneously extruded using extruders corresponding in number to the number of layers. The extruded resin or resin composition of each layer is sent to an annular die through a feed pipe to produce a tubular film in which each layer is laminated through the annular die. Subsequently, air (air, nitrogen, etc.) is blown into the film to form bubbles, and the film is stretched in the MD and TD directions to produce a PTP sheet.

The MD draw ratio (DDR) of the film is preferably 4 to 15 times, more preferably 5 to 10 times. When the MD draw ratio is 4 times or more,
The pulsation of bubbles tends to be suppressed, and the stretching tends to be stabilized.
The TD draw ratio (BUR) of the film is preferably 1.2 to 4 times, more preferably 1.5 to 3 times. When the TD draw ratio is 1.2 times or more, the pulsation of bubbles tends to be suppressed, and the drawing tends to be stabilized.
The MD draw ratio can be adjusted by the speed of the pinch rollers, and the TD draw ratio can be adjusted by adjusting the volume of air blown into the film.

<Molded body>
The molded article of the present embodiment is characterized by including the PTP sheet of the present embodiment described above.
The molded product of the present embodiment can be suitably used as a bottom material for PTP, and in particular, from the viewpoint of excellent heat sealability at low temperatures and recyclability, PTP for lid material for PTP made of polypropylene resin It is preferable to use it as a sole material.

The shape of the molded body as the bottom material for PTP is not particularly limited as long as it has a recess for containing the contents. ) or circular (circle, oval, etc.), and a rectangle may have rounded corners.
The size of the molded body as the PTP bottom material is not particularly limited, and may be appropriately determined according to the size and number of the contents. More preferably, it is 2 to 10 mm. In particular, when the shape of the opening portion and the bottom portion of the recess is circular, the diameter of the opening portion is preferably 5 to 150 mm, more preferably 9 to 100 mm. Also, the diameter of the bottom portion is preferably 5 to 20% of the diameter of the opening portion.
Moreover, although the flange portion, which is a portion other than the recess, is not particularly limited, it is preferably provided so as to extend in a direction orthogonal to the depth direction of the recess. The average width of the flange portion is, for example, preferably 2 to 100 mm, more preferably 4 to 50 mm.

In the molded product, the pressing load of the PTP sheet is preferably 15 to 21N, more preferably 17 to 19N. When the indentation load is within the above range, it has appropriate flexibility and rigidity, and tends to reduce the risk of damage to the esophageal wall when a fragment of the PTP sheet is accidentally swallowed.
Methods for controlling the indentation load of the molded body include, for example, a method of increasing the indentation load by increasing the thickness of the film or providing a reinforcing layer, a method of reducing the indentation load by reducing the degree of crystallinity, and the like. is mentioned.
In addition, the indentation load of the compact can be specifically determined by the method described in Examples below.

<Method for manufacturing molded body>
The method for producing the molded article of the present embodiment is not particularly limited, and the molded article can be produced by molding the PTP sheet of the present embodiment. For example, when the molded article is a bottom material for PTP, it can be produced by a conventionally known method using a PTP molding machine.

Hereinafter, the present embodiment will be described with specific examples and comparative examples, but the present embodiment is not limited to these.

Measurement and evaluation methods used in Examples and Comparative Examples are as follows.

<Static friction coefficient of sealing surface>
The static friction coefficient of the sealing surface of the PTP sheet was measured using a friction coefficient measuring device (“FRICTION TESTER TR” manufactured by TOYOSEIKI). A PTP sheet was used for both the moving test piece and the fixed test piece, and the static friction coefficient between the sealing surfaces of the heat seal layers of the PTP sheet was measured. The test conditions were a test speed of 1000 mm/min, a moving distance of 120 mm, and a slider mass of 500 g.
When the coefficient of static friction was 0.7 or less, it was evaluated as "good (good)", and when it exceeded 0.7, it was evaluated as "poor (poor)".

<Tensile test>
(High temperature tensile test)
A test piece having the shape shown in FIG. 1 was cut out from each resin sheet and PTP sheet as raw materials. The end of this test piece is attached to a precision universal testing machine ("Tensilon with high temperature tank" manufactured by A&D Co., Ltd.) at 125 ° C. so that the distance between chucks is 30 mm, and the moving speed between chucks is It was moved at 200 mm/min, and the tensile stress at 150% elongation (150% tensile stress) and the upper yield point were measured. The values obtained by averaging the values measured for each of the three test pieces were taken as the 150% tensile stress and the upper yield point of the resin sheet and the PTP sheet as raw materials.
(Normal temperature tensile test>
The raw material resin sheet and PTP sheet were subjected to a tensile test at room temperature in accordance with JIS K7127, and the tensile modulus (MPa) of the resin sheet, the MD tensile modulus (MPa) and TD tensile modulus of the PTP sheet ( MPa) was measured.
Specifically, a strip-shaped test piece (150 mm long×10 mm wide) was cut out from each of a resin sheet made of only one type of raw material resin produced by a heat press and a PTP sheet. The end of this test piece was attached to a precision universal testing machine (manufactured by Shimadzu Corporation, "Autograph") so that the distance between chucks was 50 mm, and the movement speed between chucks was 200 mm/min. , and the load at 2% elongation was taken as the tensile modulus (MPa). The values obtained by averaging the values measured for each of the three test pieces were taken as the tensile elastic modulus of the raw material resin sheet and the MD tensile elastic modulus and TD tensile elastic modulus of the PTP sheet.
In addition, regarding the 150% tensile stress of the PTP sheet, when it is 1.8 to 3.0 MPa, it is “O (good)”, and when it is less than 1.8 MPa or more than 3.0 MPa, it is “× (poor)”. did.
Regarding the upper yield point of the PTP sheet, when it was 3 MPa or less, it was evaluated as "◯ (good)", and when it exceeded 3 MPa, it was evaluated as "x (bad)".
Regarding the MD tensile modulus and TD tensile modulus of the PTP sheet, if both are 400 to 600 MPa, "O (good)", but if it is less than 400 MPa or more than 600 MPa, "X (bad)". , evaluated flexibility.

<Crystal melting heat>
A sample (5 to 10 mg) was cut out from the PTP sheet and measured using a differential scanning calorimeter (DSC) ("DSC7000X" manufactured by Hitachi High-Tech Science Co., Ltd.) under a nitrogen atmosphere using indium as a calorie standard. . As for the heating program, the temperature of the sample was raised from 0°C to 200°C at a heating rate of 10°C/min. As a baseline, the heat of crystal fusion (J/g) was determined.

<Sealability>
The seal strength of the PTP sheet was measured according to the following procedure.
First, the seal layer of the PTP sheet and the TPO layer of a polypropylene film (thickness: 40 μm) prepared as described below were heat-sealed using a heat seal tester (manufactured by Tester Sangyo Co., Ltd.). At that time, the sealing temperature was 100° C., the sealing time was 0.5 seconds, and the sealing pressure was 0.25 MPa. After that, strip-shaped test pieces (PTP sheet and polypropylene film each having a length of 40 mm (a total of 80 mm) and a width of 15 mm) were cut out. The sealed portion of this test piece was placed between the chucks of a precision universal testing machine (manufactured by Shimadzu Corporation, Autograph), the heat seal line with a width of 5 mm was perpendicular to the tensile direction, and the distance between the chucks was 30 mm. The end of the test piece was attached so that A 180° peeling test was performed by moving between chucks at a moving speed of 200 mm/min, and the maximum load until the seal was completely peeled off was taken as the seal strength (N/15 mm). The values measured for each of the five test pieces were averaged and taken as the seal strength of the PTP sheet.
[Production of polypropylene film]
A two-layer polypropylene film was prepared by laminating a polypropylene resin (PP) layer and a polyolefin elastomer (TPO) layer using a co-extrusion direct inflation method.
Specifically, pellets of polypropylene (H-PP1 described later) and polyolefin elastomer (TPO-1 described later) are melted at a temperature higher than the melting temperature of the resin, and each layer is simultaneously extruded using multiple extruders. did. The extruded resin of each layer was sent to an annular die through a feed pipe to produce a tubular laminated film in which each layer was laminated through the annular die. The thickness ratio was adjusted to PP layer:TPO layer=80:20.
Subsequently, the laminated film was stretched by blowing air into it to obtain a polypropylene film having a thickness of 40 μm. In addition, the draw ratio was 30 times in MD and 2 times in TD.

<Moldability>
Using a PTP molding machine (“FBP-M1” manufactured by CKD Co., Ltd.), a PTP sheet was formed with a depth of 4 mm, an opening portion having a circular diameter of 10 mm, and a bottom portion having a circular recess having a diameter of 8 mm. It was molded into a molded body (bottom material for PTP) having a flange portion with an average width of 10 mm extending in a direction orthogonal to the longitudinal direction. Molding was performed in the range of 115 to 145° C., and the temperature range in which the concave portions were completely formed was defined as the molding temperature (° C.) of the PTP sheet.
In addition, "the recess is completely formed" means that the depth is 3.6 to 4 mm, the opening part is circular with a diameter of 9 to 10 mm, and the bottom part is a circular recess with a diameter of 7.7 to 8 mm. shall point to
In addition, when the temperature range of the molding temperature is 10 ° C or more, "○ (excellent)", when it is 7 ° C or more and less than 10 ° C, "△ (practical)", when it is less than 7 ° C, "× ( The moldability was evaluated as "defective)".

<Recyclability>
A large number of PTP sheets are cut into 10 mm × 10 mm squares, and pellets of H-PP resin (H-PP1 described later) are mixed at a mass ratio of PTP sheet: H-PP resin = 80:20, kneaded and extruded. The mixture was kneaded for 10 minutes at 200° C. and 50 rpm using a molding evaluation testing device (“Laboplastomill” manufactured by Toyo Seiki Seisakusho Co., Ltd.). The kneaded material was heat-pressed at 200° C. and a surface pressure of 0.5 MPa for 90 seconds with a hot press (manufactured by Toyo Seiki Co., Ltd.), and then heat-pressed at 200° C. and a surface pressure of 20 MPa for 60 seconds. After that, it was cooled for 1 minute to prepare a pressed sheet having a thickness of 350 to 450 μm.
The press sheet was cut into 35 mm×35 mm squares, and the b* value was measured using a colorimetric colorimeter ("ZE6000" manufactured by Nippon Denshoku Industries Co., Ltd.) under the conditions of transmission mode, 23° C., and 50% RH. The b* value of the pressed sheet was obtained by averaging the values measured for each of the three test pieces. A higher b* value indicates a higher degree of yellowing of the film.
A case where the b* value was less than 6 was evaluated as "good (excellent)", and a case where the b* value was 6 or more was evaluated as "poor (poor)", and the recyclability was evaluated.

<Indentation load>
The indentation load (N) was measured according to the following procedure for the molded article molded according to the method described in <Moldability> above.
A test piece of 17 mm x 17 mm square was cut out from the compact so as to include one pocket. The cut test piece was fixed to a jig having a hole with a diameter of 10 mm with the bottom of the pocket facing up. A precision universal testing machine (Shimadzu Corporation, Autograph) was equipped with a needle having a flat tip with a diameter of 4 mm, and the fixed test piece was vertically pushed from the bottom side of the pocket to perform an indentation load test. The measurement was performed in an environment with a temperature of 23°C and a humidity of 50% RH, with a needle moving speed of 50 mm/min. It was measured. The maximum value of the compressive load measured for each of the three test pieces was averaged, and this value was taken as the indentation load of the compact.
The case where the indentation load was 15 N or more and 21 N or less was evaluated as "Good (good)", and the case where it was less than 15 N or more than 21 N was evaluated as "Poor (poor)".

Raw materials used in Examples and Comparative Examples are as follows.

<Polypropylene (PP) resin>
・ H-PP1: Polypropylene homopolymer (“PL500A” manufactured by SunAllomer Co., Ltd.)
・ H-PP2: Polypropylene homopolymer (“VS700A” manufactured by SunAllomer Co., Ltd.)
・ H-PP3: Polypropylene homopolymer (“PLB00A” manufactured by SunAllomer Co., Ltd.)
・ R-PP1: Polypropylene random copolymer ("PC540R" manufactured by SunAllomer Co., Ltd.)
・ R-PP2: polypropylene random copolymer ("Sumitomo Noblen (registered trademark) S131" manufactured by Sumitomo Chemical Co., Ltd.)
・ R-PP3: Polypropylene random copolymer (“PS320M” manufactured by SunAllomer Co., Ltd.)

<Thermoplastic olefin elastomer (TPO)>
・TPO-1: Propylene-α-olefin copolymer (Tafmer (registered trademark) XM7070S, manufactured by Mitsui Chemicals, Inc.)

Table 1 shows the physical properties of the polypropylene-based resin and the olefin-based thermoplastic elastomer.

[Example 1]
A two-layer PTP in which a substrate layer made of a mixture of H-PP1 and R-PP1 and a heat seal layer made of a mixture of R-PP1 and TPO-1 are laminated using a coextrusion direct inflation method. A sheet for
Specifically, an extruder was used for each layer, pellets of a resin as a raw material were melted at a temperature higher than the melting temperature of the resin, and each layer was simultaneously extruded from the respective extruders. The extruded resin of each layer was sent to an annular die through a feed pipe to prepare a tubular laminated film in which each layer was laminated through the annular die. In addition, the thickness ratio was adjusted so that the base material layer:TPO layer=90:10.
Subsequently, by blowing air into the laminated film to stretch it, a PTP sheet having a thickness of 300 μm was obtained.
Table 2 shows the composition and measurement/evaluation results of each physical property.

[Examples 2 to 7, Comparative Examples 1 to 5]
In Examples 2 to 7 and Comparative Examples 1 to 5, PTP sheets were produced in the same manner as in Example 1 except that the raw materials, layer ratios, etc. were changed as shown in Tables 2 and 3.
Tables 2 and 3 show the composition and measurement/evaluation results of each physical property.

[Comparative Example 6]
With reference to Example 2 described in JP-A-11-129417, the layer structure with a thickness of 0.30 mm is H-PP1 / H-PP1 (85% by mass) + dicyclopentadiene petroleum resin (15% by mass) / A three-layer sheet made of H-PP1 was produced in the same manner as in Example 1 to obtain a PP sheet. The thickness of each layer was 0.015 mm/0.27 mm/0.015 mm.
As shown in Table 3, the obtained PP sheet was used as a PTP sheet.
Table 3 shows the composition and measurement/evaluation results of each physical property.

The PTP sheet of the present invention can be suitably used for packaging pharmaceuticals such as tablets and capsules, and foods such as candies and chocolates.

Claims (6)

including polypropylene resin,
The thickness is 200 to 400 μm,
When a tensile test is performed at 125 ° C., the tensile stress at 150% elongation (150% tensile stress) is 1.8 to 3.0 MPa,
A PTP sheet characterized by having a heat of crystal fusion of 63.0 to 80.0 J/g measured by a differential scanning calorimeter (DSC). 2. The PTP sheet according to claim 1, comprising at least two layers, one of which is a heat-sealing layer, and the static friction coefficient of the sealing surface of said heat-sealing layer is 0.7 or less. 3. The PTP sheet according to claim 2, wherein the sealing strength is 8 N/15 mm or more when a polypropylene film having a thickness of 20 to 40 μm is heat-sealed at 100° C. to the sealing surface of the heat-sealing layer. The PTP sheet according to any one of claims 1 to 3, wherein an upper yield point does not exist or, if it exists, it is 3 MPa or less when a tensile test is performed at 125°C. The PTP sheet according to any one of claims 2 to 4, wherein the heat seal layer contains a polyolefin thermoplastic elastomer. including the PTP sheet according to any one of claims 1 to 5,
A molded product, wherein the PTP sheet has an indentation load of 15 to 21N.

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