JPS60165221A - Manufacture of polypropylene sheet for press through package - Google Patents

Abstract

PURPOSE:To obtain the polypropylene sheet excellent in transparence, theremoforming property and safety by annealing the resin composition composed of 100pts.wt. polypropylene and 3-20pts.wt. hydrogenated petrol resin at the temperature equal to or higher than 50 deg.C for 30min or more, after said resin composition has been extruded. CONSTITUTION:The hydrogenated petrol resin of 3-20pts.wt., preferably 6- 11pts.wt., to 100pts.wt. polypropylene resin is preliminarily blended with polypropylene stabilizer by a Henschel mixer, etc. After said blended resin has been extruded into a resin composition by a extruder, etc. it is sheeted by a T die process, etc. Its annealing is carried out at the annealing temperature equal to or higher than 50 deg.C, preferably at the range of 80-130 deg.C, for 30min or more, preferably for 60min or more. Thus obtained sheet for PTP package is excellent in the resistance for permeability of moisture, transparence and safety, and further excellent in also thermoforming property at TPT package.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a polypropylene sheet that has excellent transparency, thermoformability, and safety and is suitable for press-through packaging (hereinafter abbreviated as FTP packaging).

Conventionally, hard vinyl chloride plastic sheets (hereinafter abbreviated as PVC sheets) have been mainly used for FTP 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 antibiotics. There are drawbacks. Therefore, the emergence of a packaging sheet (PTI) that is cheaper and has lower moisture permeability is desired.

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.

However, one way to improve the transparency of polypropylene sheets is to add dibenzylitensorbitol blue nucleating agent to polypropylene, and one way to improve thermoformability is to blend polypropylene with polyethylene. However, each type has its advantages and disadvantages; for example, the former has poor moldability, and the latter has poor transparency, which poses problems for use in FTP packaging.

A method for simultaneously improving the transparency and thermoformability of a polypropylene sheet is to hydrogenate the polypropylene, but the sheet obtained by this method is eluted with butahan (hereinafter referred to as 1., -f (abbreviated as T)). The amount is so large that many do not meet the standards (150 ppm or less) of the Ministry of Health and Welfare Notification No. 20, and the reality is that they are virtually unusable.

The inventors of the present invention have conducted extensive studies to solve the above problem, and have found that if the sheet is annealed at a temperature above a certain level for a certain period of time, a sheet that satisfies the standards of Ministry of Health and Welfare Notification No. 20 can be obtained. They discovered this and arrived at the present invention.

That is, the present invention provides a press characterized in that after extrusion molding a resin composition consisting of 100 parts by weight of polypropylene and 3 to 20 parts by weight of hydrogenated petroleum resin, the resin composition is annealed at a temperature of 50° C. or higher for 30 minutes or more. This is a method for manufacturing polypropylene sheets for through-pack packaging.

In the present invention, polypropylene includes α-polypropylene, propylene and ethylene, butene-1, etc.
Random copolymers with olefins can be used. Among them, the melt flow index (hereinafter abbreviated as MI, unit: l/1) measured according to Multiplicity 14 of JIS K7210.
Polypropylene having an o content of 1 to 4 is preferable, and homopolypropylene is preferable in view of the balance between transparency and moldability. If +nI is less than 1, the transparency will be poor, and if IVI is more than 4, it will become sticky during thermoforming, resulting in poor moldability.

The hydrogenated petroleum resin used in the present invention is an aromatic hydrocarbon hydride, a terpene resin hydride, etc.
Specifically, one or two of various aromatic unsaturated orocarbons such as styrene, α-methylstyrene, vinyltoluene, vinylxylene, propenylbenzene, indene, methylindene, and ethylindene, arsenic, and/or terpenes. Hydrogenated resin obtained by polymerizing a mixture of more than 1 species, boiling point 20 as a by-product of petroleum decomposition and reforming.
Examples include hydrogenated resins obtained by polymerizing fractions at -300°C, particularly from 150 to 300°C. Among them, the softening point measured by the JIS K5902 ring and ball method is 124.
Aromatic hydrocarbon-based hydrides with a temperature of .degree. C. or higher have a small amount of .pi.-HT bathed out (preferably).

In the present invention, the amount of hydrogenated petroleum resin used varies depending on its softening point, but is 6 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, the heat build-up 1* property will deteriorate.

In the present invention, polypropylene and hydrogenated petroleum resin are
It is mixed in advance with a stabilizer for polypropylene using a known machine such as a Henschel mixer, made into a resin composition using a known machine such as an extruder, then formed into a sheet using a known method such as the T-die method, and then annealed. Ru.

In the present invention, annealing treatment after forming into a sheet is important, and the annealing temperature is 50°C or higher, preferably 80 to 130°C. Below 50°C, the effect of suppressing -HT elution is insufficient and the amount of elution increases. Further, the annealing time is 60 minutes or more, more preferably 60 minutes or more. If the time is less than 30 minutes, the annealing effect will be insufficient and the amount of 7L-H'l' elution will increase.

The FTP packaging sheet obtained in this way has excellent moisture permeability, transparency, and safety, and also has excellent aging formability during FTP packaging, and can be put into practical use by being put into a molding machine for FTP packaging. be given

Note that P'I"l) packaging is a form of packaging in which tablets, capsules, etc. are packaged with a plastic sheet pocket and aluminum foil that seals the pocket. Usually, a thermoplastic sheet is thermoformed and the tablets, capsules, etc. This is done using a high-speed automatic packaging machine that continuously performs the steps of automatically filling capsules, etc., sealing with aluminum foil, making perforations and thrifts, and punching out the outer periphery.

The P'll"P packaging sheet obtained by the production method of the present invention has excellent formability during thermoforming, and also has excellent thermal adhesion with aluminum foil and punching properties, so it has no uneven thickness. Soaked FTP packaged products with less water can be obtained at high speed.

Furthermore, the quality of the obtained FTP 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 Ditert-butyl-p~cresol 01 parts by weight, calcium stearate 01 parts by weight were blended +VI=2
10 parts by weight of homopolypropylene 100 weight Jlt (exactly) was blended with 10 parts by weight of hydrogenated petroleum resin with a softening color of 125°C, and after mixing in a Henschel mixer, the cylinder diameter d
Pellets were extruded at 240° C. using a Qmm extruder.

This pellet was heated to 240℃ with a cylinder diameter of 4 with a T die.
Made into a sheet using a 0.0-speed extruder, with a width of 200mm and a thickness of 0.25mm.
7-t of am was obtained.

This sheet was then annealed at 80°C for 120 minutes and p'
An RP packaging sheet was obtained.

The obtained sheet is passed through an FTP packaging machine manufactured by Kanae Co., Ltd. *1
PTP packaging was performed using ooo, and the moldability was evaluated. In addition, the transparency and moisture permeability of this sheet and the amount of elution of -HT were also measured. The results are shown in Table-1.

In addition, transparency was measured by measuring haze according to ASTM-D-1o 03, and moisture permeability was measured according to ASTIVi-E-96. , -HT elution amount was determined in accordance with Ministry of Health and Welfare Notification No. 20.

Examples 2 and 6 and Comparative Examples 1 to 5 Sheets were obtained in the same manner as in Example 1, except that the annealing temperature was changed as shown in Table 1. The various physical properties and moldability of the obtained sheet were evaluated. The results are shown in Table-1.

Examples 4 to 6 and Comparative Example 4 A sheet was obtained in the same manner as in Example 1 except that the annealing time was changed as shown in Table 1. The various physical properties and moldability of the obtained sheet were evaluated. The results are shown in Table-1.

Example 48 and Comparative Examples 5.6 Sheets were obtained in the same manner as in Example 3, except that the hydrogenated petroleum resin having the softening point shown in Table 1 was used in the amount shown in Table 1. The various physical properties and moldability of the obtained sheet were evaluated. The results are shown in Table-1.

Claims (1)

[Claims] 1 100 parts by weight of polypropylene and 3 to 2 parts of hydrogenated petroleum resin
After extrusion molding a resin composition consisting of 0 parts by weight, 50°C
A method for producing a polypropylene sheet for press-through pack packaging, characterized by annealing at a temperature above 60 minutes or more. The manufacturing method according to claim 1, wherein the dihydrogenated petroleum resin has a softening point of 124° C. or higher.