JPH0442178B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is directed to press-through packaging (hereinafter referred to as
It is abbreviated as PTP packaging. ) Polypropylene sheet with excellent transparency, thermoformability and safety. Conventionally, rigid vinyl chloride resin sheets (hereinafter abbreviated as PVC sheets) have been mainly used for PTP packaging. However, the moisture permeability of PVC sheets is too high for pharmaceuticals that are susceptible to deterioration due to moisture, such as aspirin and biomaterials. Furthermore, they are used by laminating polyvinylidene chloride, which has a low moisture permeability, and are therefore expensive. There are drawbacks. Therefore, there is a desire for a resin sheet suitable for PTP packaging that is cheaper and has lower moisture permeability. On the other hand, although polypropylene sheets have lower moisture permeability than PVC sheets, they have problems with transparency and thermoformability, and are currently hardly used in PTP packaging. By the way, a method for improving the transparency of polypropylene sheets is to add a nucleating agent such as dibenzylidene sorbitol to polypropylene.
In addition, as a method for improving thermoformability, there is a known method of blending polyethylene with polypropylene, but each method has its advantages and disadvantages.For example, the former has poor moldability, and the latter has poor transparency. There are problems when using it for PTP packaging. One way to simultaneously improve the transparency and thermoformability of polypropylene sheets is to blend polypropylene with hydrogen petroleum resin. Although it is suitable for packaging, the sheet obtained by this method has a large amount of normal heptane (hereinafter abbreviated as n-HT) eluted and does not meet the standards (150 ppm or less) of Ministry of Health and Welfare Notification No. 20. The reality is that many of them are virtually unusable. In order to solve the above problems, the inventors of the present invention have conducted intensive studies and found that by using a specific amount of hydrogenated petroleum resin, forming it into a sheet under specific conditions, and annealing it under specific conditions, we have achieved transparency, moisture permeation resistance, and heat resistance. Excellent moldability,
It was discovered that a sheet whose n-HT elution amount satisfies the standards of Ministry of Health and Welfare Notification No. 20 can be stably obtained, and the present invention was achieved. That is, the present invention provides a polypropylene resin composition containing 3 to 20 parts by weight of hydrogenated petroleum resin based on 100 parts by weight of polypropylene at a chill roll temperature.
Sheeting at a temperature of 70°C or higher, then
This is a polypropylene sheet for press-through packaging, which is characterized by being annealed at a temperature of 50°C or higher for 30 minutes or more. In the present invention, as the polypropylene, homopolypropylene, a random copolymer of propylene and an α-olefin such as ethylene or butene-1 can be used. Among them, the conditions of JIS K7210
The melt flow index measured at 14 (hereinafter referred to as
Abbreviated as MI. Unit: g/10 minutes. ) is preferably 1 to 4, and homopolypropylene is more preferable in view of the balance between transparency and moldability. If the MI is less than 1, the transparency will be poor, and if the MI is more than 4, the thermoformability will be sticky and the moldability will be poor. The hydrogenated petroleum resin used in the present invention is
Aromatic hydrocarbon hydrides, terpene resin hydrides, etc., specifically styrene, α-methylstyrene, vinyltoluene, vinylxylene, propenylbenzene, indene, methylindene,
Hydrogenated resins obtained by polymerizing one or a mixture of two or more of various aromatic unsaturated hydrocarbons such as ethyl indene and/or terpenes, and when decomposing or reforming petroleum. By-product boiling point 20
Examples include hydrogenated resins obtained by polymerizing fractions at ~300°C, particularly 150-300°C. In the present invention, the amount of hydrogenated petroleum resin used varies depending on its softening point, but is 3 to 20 parts by weight, preferably 6 to 11 parts by weight, based on 100 parts by weight of polypropylene. If the amount used is less than 3 parts by weight, the effect of improving transparency and thermoformability will be insufficient, and if it is used in excess of 20 parts by weight, thermoformability will deteriorate. In the present invention, polypropylene and hydrogenated petroleum resin are prepared in advance together with a polypropylene stabilizer.
It is blended using a known machine such as a Henschel mixer, made into a resin composition using a known machine such as an extruder, and then T
Sheeting is performed using a die method or the like, and then annealing is performed. First, sheeting is performed at a chill roll temperature of 70°C or higher, and by employing this chill roll temperature, the amount of n-HT elution shows a surprising decrease.
Chill roll temperature is 70℃ or higher, preferably 75-125
℃, and below 70℃, the effect is insufficient and n-
The amount of HT elution increases. The sheet obtained above was annealed and n-
The amount of HT elution can be further reduced. The annealing temperature is 50 to 130°C, preferably 80 to 125°C. The effect is insufficient below 50°C. Further, the annealing time is 30 minutes or more, more preferably 60 minutes or more. If the time is less than 30 minutes, the effect is insufficient. The polypropylene sheet for PTP packaging of the present invention has excellent moisture permeability, transparency, and safety, and
This sheet also has excellent thermoformability during PTP packaging.
It is put into practical use by being put into a molding machine for PTP packaging. PTP packaging is a form of packaging in which tablets, capsules, etc. are wrapped in a plastic sheet pocket and aluminum foil to seal it. Usually, a thermoplastic sheet is thermoformed, and tablets, capsules, etc. are automatically packaged into this. The process is carried out using a high-speed automatic packaging machine that continuously performs the steps of filling, sealing with aluminum foil, making perforations and slits, and punching out the outer periphery. The polypropylene sheet for PTP packaging of the present invention has excellent moldability during thermoforming, and also has excellent thermal adhesion with aluminum foil and punching properties, so it can produce excellent PTP packaging products with less uneven thickness. Obtained at high speed.
Furthermore, the quality of the obtained PTP packaged product is excellent in terms of transparency, moisture permeability, and safety. The present invention will be further explained below with reference to Examples. Example 1 10 parts by weight of a hydrogenated petroleum resin with a softening point of 123°C was blended with 100 parts by weight of homopolypropylene of MI = 2, which was blended with 0.1 parts by weight of diterciabutyl-p-cresol and 0.1 parts by weight of calcium stearate.
After mixing with Henschel mixer, cylinder diameter
Pellets were obtained by extrusion at 240° C. using a 40 mm extruder. The pellets are chilled at a temperature of 80℃ and extruded at a temperature of 80℃.
Cylinder diameter 40mm with T die set at 240℃
Sheeted with an extruder, width 200mm, thickness 0.25mm
A sheet of mm was obtained. Next, this sheet was annealed at 80℃ for 40 minutes,
A polypropylene sheet for PTP packaging was obtained. This sheet is wrapped in a PTP packaging machine manufactured by Kanae Co., Ltd.
PTP packaging was performed using M2000 and moldability was evaluated. In addition, the transparency, moisture permeability, n-
The amount of HT elution was also measured. The results are shown in Table-1. Transparency was determined by measuring haze according to ASTM-D-1003, and moisture permeability was determined according to ASTM-E-96.
The n-HT elution amount was measured in accordance with Ministry of Health and Welfare Notification No. 20. Comparative Example 1 A polypropylene sheet for PTP packaging was obtained in the same manner as in Example 1 except that annealing was not performed. The moldability and physical properties of the obtained sheet were evaluated. The results are shown in Table-1. Examples 2 and 3 and Comparative Example 2 Sheets were obtained in the same manner as in Example 1, except that annealing was performed for the time shown in Table 1. The various physical properties and moldability of the obtained sheet were evaluated. The results are shown in Table-1.

[Table] Examples 4 and 5 and Comparative Examples 3 and 4 Sheets were obtained in the same manner as in Example 2, except that annealing was performed at the temperatures shown in Table 1. The various physical properties and moldability of the sheet were evaluated. The results are shown in Table 2 together with Example 2.

[Table] Examples 6, 7, Comparative Example 5 In Example-2, the chill roll temperature is shown in Table-1.
In the same manner as in Example-2 except that the temperature shown in
Got a sheet. The various physical properties and moldability of the obtained sheet were evaluated. The results are shown in Table 3 together with Example 2.

[Table] Examples 8 and 9 and Comparative Examples 6 and 7 In Example-2, as hydrogenated petroleum resin,
A sheet was obtained in the same manner as in Example 2, except that the softening points shown in Table 4 were used in the amounts shown in Table 2. The various physical properties and moldability of the obtained sheet were evaluated. The results are shown in Table 4 together with Example 2.

【table】

Claims (1)

[Claims] 1. A polypropylene resin composition containing 3 to 20 parts by weight of hydrogenated petroleum resin based on 100 parts by weight of polypropylene is sheeted at a chill roll temperature of 70°C or higher, and then annealed at a temperature of 50 to 130°C for 30 minutes or more. A polypropylene sheet for press-through packaging featuring: