JP2001131305A - Polypropylene-based resin sheet for press-through package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polypropylene-based resin sheet for press-through package(PTP) having a wide moldable temperature range and suppressed in generating curls during heat molding the resin sheet. SOLUTION: This polypropylene-based resin sheet for PTP comprises at least one species of polymers selected from a propylene homopolymer and an ethylene/propylene copolymer having <1 wt.% content of ethylene repeating units, a propylene/butene-1 random copolymer containing 10-30 wt.% of butene-1 repeating units and a filler. When the sum total of the aforesaid polymer and the propylene/butene-1 random copolymer is brought to be 100 pts.wt., the content of the polymer is 80-95 pts.wt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a PTP commonly used for packaging solid preparations in the field of pharmaceutical packaging.
(Press-through pack) It relates to a polypropylene sheet for packaging.

[0002]

2. Description of the Related Art In the field of pharmaceutical packaging, PTP packaging, which is generally used for packaging solid tablets such as tablets and capsules, is mainly made of hard vinyl chloride in terms of transparency, moldability, stiffness and cost. Using a resin sheet as a bottom material, forming the bottom material into a pocket shape, filling a solid agent therein,
A package sealed with a lid made of aluminum foil.
It was put into practical use in the 0's and has become widespread. Tablets and capsules may be deteriorated or deformed due to moisture absorption. They may be wrapped in a secondary film such as a pillow wrap with a composite film containing aluminum foil, or a polyvinylidene chloride with excellent moisture-proof properties may be applied to a rigid polyvinyl chloride resin sheet. This has been dealt with by using a sheet in which resin is compounded by coating or the like, but these have problems in terms of cost. In addition, there is an increasing tendency for vinyl chloride resins to be avoided due to problems in disposal. Therefore, sheets made of an olefin-based resin, such as a polypropylene-based resin, have been attracting attention for their moisture-proof properties, low cost, easy processing, and the like, and have come to be used as PTP packaging sheets. However, polypropylene-based resin as a PTP packaging sheet has a narrower moldable temperature range than a vinyl chloride resin in molding a pocket for storing tablets, and therefore is inferior in moldability and requires strict management of production conditions. . In addition, remarkable curl (warpage) occurs when thermoforming or heat sealing with an aluminum film lid material, and there is a problem in appearance and compatibility with an automatic packaging line. In order to solve the above-mentioned problem of the moldability of the polypropylene resin sheet for PTP packaging, various studies have been made so far. For example, an attempt to use an ethylene / propylene random copolymer as a base resin as a polypropylene resin has been made. (Japanese Patent Laid-Open No. 53-6695)
2). Although the moldable temperature range is widened by this method, significant curl occurs during thermoforming or heat sealing. On the other hand, a technique of adopting a multilayer structure and adding a large amount of petroleum resin having good moldability to the intermediate layer has been put to practical use, but it is expensive in terms of cost and is not necessarily widely used.

[0003]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems in the polypropylene resin sheet for PTP packaging, and has a wide moldable temperature range and suppresses curling during thermoforming. An object of the present invention is to provide a system resin sheet.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a propylene / butene-1 random copolymer containing a specific amount of a butene-1 repeating unit is converted into a propylene homopolymer. Alternatively, by blending a specific amount with an ethylene / propylene copolymer having a relatively low ethylene content or a mixture thereof, the moldable temperature range can be widened, and curling during sheet thermoforming or heat sealing can be suppressed. This led to the present invention.
That is, the present invention provides at least one polymer selected from a propylene homopolymer and an ethylene / propylene copolymer having an ethylene repeating unit content of 1% by weight or less, and a butene-1 repeating unit content of 10% or less. Propylene / butene-1 random copolymer in an amount of from 30 to 30% by weight, and when the total of the polymer and the propylene / butene-1 random copolymer is 100 parts by weight, the content of the polymer is 80 to A polypropylene-based resin sheet for PTP packaging, comprising 95 parts by weight of a resin composition.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The resin composition constituting the polypropylene-based resin sheet for PTP packaging of the present invention comprises, as resin components, ethylene / propylene having a propylene homopolymer and an ethylene repeating unit content of 1% by weight or less. At least one polymer selected from copolymers and butene-1
Propylene having a repeating unit content of 10 to 30% by weight /
Butene-1 random copolymer, the total of said polymer and propylene / butene-1 random copolymer being 100
The polymer has a content of 80 to 95 parts by weight in terms of parts by weight. If the ethylene / propylene copolymer has an ethylene repeating unit content of more than 1% by weight, curling during thermoforming or heat sealing becomes remarkable, which is not preferable. Further, when a copolymer with propylene having a butene-1 repeating unit content of less than 10% by weight is used, a sufficient moldable temperature width expanding effect cannot be obtained. Further, it is difficult to produce a propylene / butene-1 copolymer having a butene-1 repeating unit content of more than 30% by weight. The total of the polymer and the propylene / butene-1 random copolymer is 1
If the content of the polymer exceeds 95 parts by weight when the amount is 00 parts by weight, the effect of expanding the moldable temperature range is not sufficient,
If the amount is less than 80 parts by weight, the curl increases during thermoforming or heat sealing, which is not preferable. In addition, at least one polymer selected from the propylene homopolymer and an ethylene / propylene copolymer having an ethylene repeating unit content of 1% by weight or less, and a butene-1 repeating unit content of 10% or less.
The propylene / butene-1 random copolymer of up to 30% by weight may be collectively referred to as a polypropylene resin.

In the present invention, in order to suppress the occurrence of curling during thermoforming or heat sealing of the polypropylene resin sheet for PTP packaging of the present invention, the thermoplastic resin constituting the sheet contains a filler. Is preferred. As the filler, any of an inorganic filler and an organic filler can be applied. Specifically, a material that satisfies the balance of desired moldability, curl suppression, and transparency required as a PTP packaging material is selected. For example, carbonates such as calcium carbonate, magnesium carbonate and barium carbonate, sulfates such as barium sulfate, magnesium sulfate and calcium sulfate, phosphates such as magnesium phosphate and calcium phosphate, magnesium hydroxide and aluminum hydroxide Hydroxides, such as alumina, silica, magnesium oxide, calcium oxide, zinc oxide, oxides such as titanium oxide, aluminum powder, zeolite, kaolin, shirasu, clay, diatomaceous earth, talc, carbon black, inorganic fillers such as clay, Used among organic fillers such as cellulose powder such as pulp powder, nylon powder, polycarbonate powder, polypropylene powder, synthetic resin powder such as polymethyl methacrylate beads and polystyrene beads, activated carbon, chitosan powder, chitin powder, and starch. Processing of polypropylene resin It is those that do not melt in degrees. In particular, an inorganic filler which has a high curl suppressing effect and is advantageous in terms of cost is preferable.
The refractive index difference at 3 ° C. is 0.04 or less, particularly 0.03 or less;
In particular, those having a specific surface area of not more than 100 m ² / g, especially those having a specific surface area of not more than 50 m ² / g by the BET adsorption method are excellent in sheet workability. Therefore, it is preferable.

The filler content of the resin composition is usually in the range of 5 to 50% by weight of the whole resin composition, preferably 7 to 40% by weight, more preferably 10 to 30% by weight.
It is. If the content of the filler is less than 5% by weight, the curl suppressing effect is not sufficient, and if it is more than 50% by weight, the dispersion of the filler in the resin composition tends to be insufficient, which is not preferable.

As long as the effects of the present invention are not significantly impaired, the above resin composition comprises a random copolymer of propylene and an α-olefin other than butene such as pentene, hexene, heptene, ethylene, butene, pentene, Α-olefin homopolymers such as hexene and heptene, copolymers composed of ethylene and α-olefins such as butene, pentene, hexene, and heptene; polymers composed of cyclic olefins; ethylene / methyl methacrylate copolymers; Copolymer of ethylene and carboxylic acid derivative having an ethylenically unsaturated bond such as vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / vinyl acetate / methyl methacrylate copolymer, polyvinyl alcohol, polyvinyl acetate , Polycarbonate, polyester, polyamide, poly Styrene, polymethyl methacrylate, petroleum resin, thermoplastic elastomer, rubber, can contain polymers such as hydrogenated rubber.

In particular, when the resin composition contains a petroleum resin, the polypropylene resin sheet of the present invention can have excellent water vapor barrier properties. The petroleum resin includes a synthetic resin-based petroleum resin and a natural product-based petroleum resin, and a synthetic resin-based petroleum resin is preferable. Synthetic resin-based petroleum resins include aliphatic hydrocarbon resins, aromatic hydrocarbon resins, alicyclic saturated hydrocarbon resins, and copolymers, but from the viewpoint of odor, transparency, etc. A cyclic saturated hydrocarbon resin-based petroleum resin is preferred. In the present invention, when the resin composition contains a petroleum resin, the content is usually 1 to 1
0% by weight. If the addition amount is less than 1% by weight, a sufficient effect of improving the water vapor barrier property is difficult to be exhibited, and if it exceeds 10% by weight, the concentration of the low molecular weight component increases, which is not preferred.

Further, as long as the effects of the present invention are not significantly impaired, the resin composition may contain an antioxidant, an ultraviolet absorber,
Light stabilizers, lubricants, anti-blocking agents, antistatic agents,
It may contain a surfactant, a dye, a pigment, a fire retardant, a plasticizer, a crystal nucleating agent, and the like.

[0011] The resin composition suitable for the polypropylene resin sheet for PTP packaging of the present invention is a Banbury mixer,
Batch kneaders such as kneaders and rolls, single screw extruders,
It can be produced by an ordinary method using a continuous kneader such as a twin-screw extruder or a calender roll. The polypropylene-based resin sheet for PTP packaging of the present invention can be produced by forming the resin composition obtained as described above into a sheet by a conventional method such as T-die extrusion or calendering. The thickness of the sheet of the present invention is usually 0.1.
Within the range of 16 to 0.6 mm, preferably 0.25 to
It is in the range of 0.35 mm.

The polypropylene-based resin sheet for PTP packaging of the present invention can be further thermoformed by a method such as vacuum forming or pressure forming to form a molded sheet for PTP packaging having a pocket for filling a solid agent, and then provide it for PTP packaging. it can.

[0013]

Since the polypropylene resin sheet of the present invention has a wide moldable temperature range, it is suitable as a PTP packaging sheet.

[0014]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited to these examples. The evaluation method of the sheet performance is as follows. Evaluation of moldability Blister pack molding machine FBP-M2 manufactured by CKD Corporation
The molding temperature is increased from 130 ° C to 150 ° C in 2 ° C increments using
And molding was performed at each molding temperature. Molding, pocket shape is bottom 10mmΦ, top 9mmΦ,
Plug assist pressure forming was performed at a rate of 50 shots / min using a mold having a depth of 4.1 mm and two sides of 10 pockets per shot.
The moldability was evaluated based on the moldable temperature range. The moldable temperature range was determined in consideration of the ability to follow the mold (mold followability), the uneven appearance of the top of the pocket, and the thickness of the top. The mold followability and the appearance unevenness of the top were determined by visual sensory evaluation, and the thickness of the top was determined by measurement with a dial gauge. A wider moldable temperature range is better, and is 5 ° C. or more as a guide. Evaluation of curl Molding was performed under conditions showing good moldability in the above evaluation of moldability, heat-sealed with aluminum foil at 175 ° C without filling the contents, and a slitter (ruled line) was inserted at 130 ° C. After, width 3
A molded product punched out at 7 mm, a length of 94 mm, and a corner of 5 mmR was placed on a flat surface, and the warpage height of the molded product 5 minutes after punching was measured. The height of the four corners of each molded product was measured for ten molded products, and the average value was obtained and evaluated. As the aluminum foil, a 20 μm-thick hard aluminum foil coated with maleated polypropylene at a thickness of 5 μm was used. It is preferable that the curl height is low, and a suitable range is 1.5 to 4.5 mm as a standard.

Example 1 Propylene homopolymer powder (MFR = 2.5 g / 1)
0 min, Tm = 158-159 ° C., refractive index at 23 ° C. =
1.50) 82.8 parts by weight, propylene / butene-1 random copolymer powder (butene-1 repeating unit content =
22% by weight, Tm = 132 ° C., refractive index at 23 ° C. = 1.
50) 9.2 parts by weight, petroleum resin (Escolets 5320, manufactured by Tonex Corporation, refractive index at 23 ° C. = 1.5)
5) 8.0 parts by weight was subjected to vent granulation at 230 ° C. using a twin-screw extruder to obtain a resin composition. This is 65mmΦ T-
230 ° C. (chill roll temperature = 30) using a die extruder
C) to form a sheet of 300 μm. Table 1 shows the evaluation results of the moldability and the curl height of the obtained sheet.

Example 2 Propylene homopolymer powder (MFR = 8.0 g / 1)
0 min, Tm = 161-162 ° C., refractive index at 23 ° C. =
1.50) 73.8 parts by weight, propylene / butene-1 random copolymer powder (butene-1 repeating unit content =
22% by weight, Tm = 132 ° C., refractive index at 23 ° C. = 1.
50) 8.2 parts by weight, petroleum resin (Escolets 5320, manufactured by Tonex Corporation), refractive index at 23 ° C. = 1.5
5) 8.0 parts by weight, basic magnesium sulfate whisker (Moth Heidi-A manufactured by Ube Materials Co., Ltd .: fiber diameter = 0.5 to 1.0 μm, fiber length = 8 to 15 μm, 23 ° C.)
The refractive index at 1.53) was subjected to vent granulation at 230 ° C. using a twin-screw extruder to obtain a resin composition. This was formed into a 300 μm sheet at 230 ° C. (chill roll temperature = 30 ° C.) using a 65 mmΦ T-die extruder. Table 1 shows the evaluation results of the moldability and curl height of the obtained sheet.

Comparative Example 1 Propylene homopolymer powder (MFR = 2.5 g / 1)
0 min, Tm = 158-159 ° C., refractive index at 23 ° C. =
1.50) 92.0 parts by weight and 8.0 parts by weight of a petroleum resin (Escolets 5320, manufactured by Tonex Corporation, refractive index at 23 ° C. = 1.55) were converted to 23 parts by using a twin-screw extruder.
Vent granulation was performed at 0 ° C. to obtain a resin composition. This is 65m
It was formed into a 300 μm sheet at 230 ° C. (chill roll temperature = 30 ° C.) using a T-die extruder with mΦ. Table 1 shows the evaluation results of the moldability and the curl height of the obtained sheet.

Comparative Example 2 Propylene homopolymer powder (MFR = 1.0 g / 1)
0 minute, Tm = 161 ° C., refractive index at 23 ° C. = 1.50)
50 parts by weight, ethylene / propylene copolymer powder (ethylene repeating unit content = 5.0%, MFR = 1.5
g / 10 min, Tm = 142 ° C., refractive index at 23 ° C. = 1.
50) 50 parts by weight were vent-granulated at 230 ° C. using a twin-screw extruder to obtain a resin composition. This is 65mmΦ T-
230 ° C. (chill roll temperature = 30) using a die extruder
C) to form a sheet of 300 μm. Table 1 shows the evaluation results of the moldability and the curl height of the obtained sheet.

[0019]

[Table 1]

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) C08L 57/02 C08L 57/02 (72) Inventor Koichi Yanase 5-1 Anesaki Kaigan, Ichihara-shi, Chiba Sumitomo Chemical Industries, Ltd. (72) Inventor Yoshifumi Furukawa 2-5-8 Higashishinagawa, Shinagawa-ku, Tokyo Sumitomo Bakelite Co., Ltd. (72) Inventor Masaki Takeda 2-5-2-8 Higashishinagawa, Shinagawa-ku, Tokyo Sumitomo Bakelite Co., Ltd. (72) Inventor Yasuo Shimobe 2-5-8 Higashishinagawa, Shinagawa-ku, Tokyo F-term in Sumitomo Bakelite Co., Ltd. 4F071 AA15X AA20 AA20X AA21X AB24 AD01 AE17 AH04 BB06 BC01 4J002 AB013 AB043 AB053 BB121 BB123 BB142 BB151BB CL003 DA036 DE076 DE086 DE106 DE136 DE146 DE236 DG046 DG056 DH046 DJ006 DJ016 DJ036 DJ046 FD016 GG02

Claims (3)

[Claims] An at least one polymer selected from a propylene homopolymer and an ethylene / propylene copolymer having an ethylene repeating unit content of 1% by weight or less, and a butene-1 repeating unit content of 10 to 10% by weight. 30% by weight of a propylene / butene-1 random copolymer, wherein the content of the polymer is 80 when the total of the polymer and the propylene / butene-1 random copolymer is 100 parts by weight.
A polypropylene resin sheet for PTP packaging, comprising a resin composition in an amount of up to 95 parts by weight. 2. The polypropylene resin sheet for PTP packaging according to claim 1, wherein the resin composition contains 5 to 50% by weight of a filler. 3. The polypropylene resin sheet for PTP packaging according to claim 1, wherein the resin composition contains a petroleum resin.