JPS60129053A - Radiation pasturizing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for radiation sterilization of packages for medical instruments such as syringe barrels, injection needles, and drip devices.

Conventionally, these packaging bodies are sandwiched between paper and plastic film, and are sterilized by infiltrating a sterilizing gas such as ethylene oxide from the rough side. These sterilization methods have the risk of sterilizing agents remaining and compromising safety, so physical sterilization methods that use ionizing radiation, such as gamma ray sterilization and electron beam sterilization, which do not have this risk, are attracting attention. We have been collecting them, and some of them have actually been put into practical use. However, sterilization using ionizing radiation
The plastic used in packaging materials has deteriorated over time.
There was a problem that Polyolefin resins are less prone to such deterioration and are actually used, but even when this polyolefin resin is used, the odor of low boiling point substances is generated due to the decomposition of the resin.

As measured by gas chromatography, this odor is caused by low-boiling aldehyde substances such as formaldehyde and acetaldehyde, and low-boiling point carboxylic acids such as acetic acid and propionic acid. Although the odor does not harm the sanitary properties of other people, it is considered a problem because the odor itself causes discomfort.

By the way, the present inventors investigated this odor and surprisingly found that this odor is closely related to the density of polyolefin resin, with a density of 0.930 g/c.
It has been found that the odor that decomposes when irradiating polyethylene resin with a molecular density of more than 200 m and less long chain branching in terms of molecular structure is extremely less than when irradiating polyolefin resin with a density less than this. Noko.

The present invention has been made based on such knowledge, and specifically, the present invention involves irradiating ionizing radiation to a packaging body made of a packaging bag made of a thermoplastic resin film containing the contents. When sterilizing, the innermost layer of the packaging bag has a density of 0.9.
This is a radiation sterilization method characterized by using a polyethylene resin of 30 o/cm or more.

Specific examples of the polyethylene resin used in the present invention include medium-low pressure polyethylene, dylene-acrylic acid copolymer resin, ethylene-methacrylic acid copolymer resin, poly-1-ethylene ionomer, ethylene-vinyl acetate copolymer resin, etc. I can do it.

In addition, when making a packaging bag, it can be used as a single polyethylene resin film or as a laminated film of other thermoplastic resin films such as other polyolefins, polyesters, or polynoamides. When used as a laminated film, it is necessary to create the polyethylene resin film so that it becomes the innermost layer of the packaging bag.

In addition, as the radiation that should be irradiated, high-energy rays known as ionizing radiation are generally used, and specifically gamma rays and electron beams are preferably used, but in addition to these, X-rays, etc. are also used. be able to.

The present invention will be explained below with reference to Examples and Comparative Examples.

<Examples and Comparative Examples> 1) Low-density polyethylene (density 0.919 g/c♂, Ml5, O) on a 25μ thick general-purpose polyester film
A laminated film was prepared by extrusion coating to a thickness of 70 μm at a resin temperature of 310° C. under the die. This laminated film was stacked with polyethylene layer surfaces and sealed on all sides so that the internal air amount was 350 cc to create a package, which was designated as Comparative Package (1).

2) Low density polyethylene (density 0.'919 (+10
♂, Ml5. O) instead of low density polyethylene (density 0
．． 923 (1/cm1, Ml3.7>), a package was prepared in the same manner as in 1), and one package was used as comparison package (2).

3) Low density polyethylene (density 0.919g/cm',
High-density polyethylene (density 0.9
44g/c♂, Ml9. A package was prepared in the same manner as in 1) using O>, and was designated as a package (3) of the present invention.

4) Ethylene-acrylic acid copolymer resin (density 0.940Q/C♂, M
l7. 'O) at 70°C under the condition that the resin temperature under the die is 280℃.
A laminated film is prepared by extrusion coating to a thickness of μ, and this laminated film is overlapping the ethylene-acrylic acid copolymer resin layer surfaces and sealed on all sides to create a package. (4).

5) Each of these packages (IL(2>(3)<4) was irradiated with γ-rays at a dose of 2.5 Mrad, and after 20 hours, the concentration of odors decomposed inside the package, i.e., formaldehyde, acetaldehyde, acetic acid) Each meter of melon was subjected to gas chromatography (GC-6AM device manufactured by Ro Ri Seisakusho Co., Ltd., T
Quantitative analysis was carried out using enaxGC (loaded with a column manufactured by Kasukuro Kogyo Co., Ltd.). The results are shown in Table 1.

In addition, each concentration of formaldehyde, acetaldehyde, and acetic acid was measured by the ΔSTM D-1505 method. Also, the unit of each concentration is rmil/IJ, [< O, 0
01J Box (f) indicates that 6 degrees is 0,001 mg/I or less.

(Margin below)

Claims (3)

[Claims] (1) When sterilizing a package consisting of a packaging bag made of a thermoplastic resin film containing the contents by irradiating it with ionizing radiation, the innermost layer of the packaging bag has a density of 0.930 g/c.
A radiation sterilization method characterized in that the polyethylene resin has a polyethylene resin of m or more. (2) The radiation sterilization method according to claim (1), wherein the polyethylene resin is medium-low pressure polyethylene. (3) A patent claim characterized in that the polyethylene resin is one selected from ethylene-acrylic acid copolymer resin, ethylene-methacrylic acid copolymer resin, polyethylene ionomer, and ethylene-vinyl acetate copolymer resin. The radiation sterilization method described in scope item (1).