JPS58216055A - Production of gamma-ray pasturized medical instrument - 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 1. Background of the Invention [Field of the Invention] The present invention relates to a method for manufacturing gamma ray sterilized medical instruments, particularly
The present invention relates to a method for manufacturing medical devices whose initial strength characteristics do not significantly decrease after wire sterilization.

[Prior art and problems]

BACKGROUND ART Currently, many medical instruments are being used as so-called disposable instruments, which can be disposed of without being reused for safety reasons such as preventing infection. Some medical instruments of this type are made of polyolefin resin such as polypropylene. However, when medical instruments made of polyolefin resin are subjected to R-ray irradiation, which is one of the sterilization methods, they tend to break easily.
In order to overcome this drawback, conventional methods have been to thicken the walls of medical devices and add antioxidants to polyolefin resins. Efforts have been made to incorporate larger amounts. However, such methods cannot necessarily suppress the decline in physical properties of polyolefin resins due to R1 gland irradiation.
Furthermore, the resulting medical equipment becomes more expensive.

■0 Purpose of the Invention Therefore, the purpose of the present invention is to provide a medical device made of olefin resin without using the above-mentioned conventional method.
It is an object of the present invention to provide a method for manufacturing a gamma ray sterilized medical instrument that can be sterilized by gamma rays without significantly reducing its initial strength characteristics.

According to this invention, when sterilizing a medical device at least partially made of a polyolefin resin whose initial strength properties are significantly reduced by irradiation with γ-rays, the irradiation with γ-rays is Provided is a method for manufacturing a gamma ray sterilized medical device, which is characterized in that the reduction in initial strength characteristics of the polyolefin resin portion is suppressed to less than 10 degrees when carried out at a temperature of 5 to 5°C.

Eyes in general? The lyolefin resin is polypropylene, and the entire medical device is made of the polyolefin resin. Also, the irradiation dose of gamma rays is 2.5 to 4
This is Mrad.

■1 Detailed description of the invention As a result of examining various methods of sterilizing medical instruments made of polyolefin resin by irradiation with gamma rays, the inventor found that the temperature was considerably lower than that of the conventional method of irradiating with gamma rays. If γ-rays are irradiated at high temperatures, the initial strength characteristics will decrease by 10%.
% (that is, the initial strength properties of 90% or more were maintained), and it was discovered that the medical instruments could be used without problems in terms of properties such as cracking and impact resistance, and in completing the present invention. The polyolefin resin forming at least a part (usually the whole) of the medical device that is subjected to gamma ray irradiation according to the present invention includes ethylene, propylene, butene, pentene,
Monomers or copolymers of α-olefins such as hexene, 4-methylpentene, heptene, octene: These α-
Majority of the weight of Ot/F/, male vinyl esters such as vinyl acetate, unsaturated organic acids (including salts, amides, and amines) such as acrylic acid, maleic anhydride, and methyl methacrylate, vinyl silanes such as vinyltrimethoxysilane, etc. Examples include random, block, or graft copolymers with or modified polymers such as chlorination, sulfonation, and oxidation.

Specifically, for example, low, medium or high density polyethylene, polypropylene, polybutene, ethylene-propylene random or block copolymer, ethylene-globylene-butene copolymer, ethylene-butene copolymer, ethylene-4-methyl These include silane copolymers, propylene-hexene copolymers, propylene-hexene-butene copolymers, and the like.

Among these polymers, those with particularly remarkable effects include polypropylene, globylene-ethylene random or block copolymers, globylene-ethylene-zotene copolymers, propylene-hexene-zotene copolymers, etc. The graft copolymer is especially polypropylene.

Medical instruments include syringe barrels and glanders, tweezers, frangoctopus tubes, connectors, drip tubes, syringe needles (hubs), catheters, bottle needles, containers, and the like. These are conveniently obtained by injection molding the polyolefin resin. - By way of example, a syringe is shown in FIG. This syringe has an outer cylinder 1 whose tip forms a chi-9 part 11a and a flange 12 on the outer periphery of the rear end. A thin tube portion 13 into which a hub of a syringe is inserted is formed at the tip of the tee 74 portion 111L. A pusher consisting of a gasket 14 and a granger 15 is inserted inside this outer tube. Gasket 14 is formed from natural rubber, styrene-butanoene rubber, or other thermoplastic elastomer. The grungy is made of the same olefin resin as the outer cylinder.

In sterilizing the above-mentioned medical instruments according to the present invention, irradiation with gamma rays is carried out at a temperature of 0°C to 5°C. If the temperature during γ-ray irradiation is less than 0℃, #:m efficiency is lower than υ,
On the other hand, if it exceeds 5C, the strength properties will deteriorate so much that it will become unusable. γ under the temperature conditions of this invention
Only by performing wire sterilization can an Ml medical device with a decrease in initial strength properties of less than 10% (that is, initial strength properties of 90 degrees or more are maintained) be obtained. The gamma ray sterilized medical instruments obtained according to the invention can be used without problems in medical procedures. The amount of γ-ray irradiation is usually 2.5 to 4 Mrad, and the irradiation is carried out in air. The sterilization effect is the same as before. Further, it can be carried out after packaging with a packaging material such as R-line ilm or a laminate film (for example, pgT-Zarlin, biaxially oriented dirizolobylene Zarlin, biaxially extended polyglopylene-polyethylene).

In addition, when an antioxidant is blended into the polyolefin resin, the above effects are further improved. Particularly preferred examples of such antioxidants are listed below.

[A] Hindered amine, phenol and phosphite compounds represented by the following formulas CI) to Vl).

2 [rot atir) [■] [■] In the formula, R1, R2, R3, R4, and R5 are alkyl groups having 1 to 181 carbon atoms, 1 to 8 carbon atoms, and 1 to 30.1 to 8 carbon atoms, respectively; tXmXn is θ~30°1~40.1~6 respectively
is an integer.

A good example of the compound represented by formula [I] is, for example, bis(2,2
, 6,6-titramethylpiperidyl) azide, bis(2,2,6,6-titramethylbiperisol) sebacate, bis(2,2,6,6-titramethylbiperisol)
such as fumarate.

Examples of formula (n) include compounds where R1 is a methyl group and m=4.

A good example of the compound of formula [111) is 1,1.3-
) lis(2-methyl-4-hydroxy-5-t-butylphenyl)butane. Further, a good example of the formula [■] is tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate. [■] and (VI
A good example of the compound of A) is a methyl group as R2, R
5 is a t-butyl group at the 2-position, and R4 is C+ 5H.
27 groups, and a compound with C3H7 group as R5.

The blending ratio of each of these components is 1 part polyolefin resin
00 parts by weight, a compound selected from the hindered amines represented by the above formula [■] and [1,1, and the formula [■]
Compounds selected from phenol to ml phosphate ester compounds shown by 1■] to [■] are each 0
．． 01 to 1 part by weight, preferably 0.01 to 0.01 parts by weight, respectively.
5 parts by weight.

CB) Heterocyclic hindered amine compounds consisting of a six-membered heterocycle containing a hindered amine nitrogen atom and optionally another heteroatom (preferably nitrogen or oxygen) (e.g. C(2,2,6,6-tetramethyl-4 −
piperidyl) sebacate, 4-benzoyloxy-2,
2,6,6-tetramethylbiperidine, succinic acid and N-
(2-hydroxyethyl)-condensate with 2,2,6,6-tetramethyl-4-hydroxypiperidine, 1.2
．． 3.4-tetra(2,2,6,6-tet, lamethyl-
4-biridyl)-butanetetracal? Kinlate, 1
．． 4-di(2,2,6,6-tetramethyl-4-diyl)-2,3-zotannoone, tris-(2,2,
6,6-tetramethyl-4-piperidyl) trimellitate, 1,2,2,6. flj-pentamethyl-4-4
Lysyl stearate, 1.2.2.6.6-2-2-tamethyl, -4-bimylinol n-octoate, bis-(
1゜2.2.6.6--s: Phthamethyl-4-piperisol) sebacate, tris-(2,2,6,6-tetramethyl-4-pi4lysyl)-nitrile acetate, 4-hydroxy- 2,2,6,6-titramethylpikarisin,
4-Hyproxyl 1,2,2,6,6-bentamethylbiperidine etc. Particularly preferably, N-(2,2゜6.6-tetramethyl-4-piperinor)sebacate or succinic acid and N-( 2-hydroxyethyl) -2,2,6,6
- condensate of tetramethyl-4-hydroxypiperisone)
and 1.3.5-) lis(3-hydroxy-2,6-tumethyl-4-alkyl-benzyl)in cyanurate (
That is, a hindered phenol-based antioxidant which is a branched alkyl group with an alkyl force of 05 to C12. For example, 1
．． 3.5-) lis(3-hydroxy-2,6-nomethyl-4-inzolobyl-pencyl)isocyanurate,
1.3.5-1-lis(3-hydroxy-2,6-nomethyl-4-tert-glutyl-4andyl)isocyanurate,
1.3.5-tris(3-hydroxy-2,6-somethyl-4-sec-butyl-bennol)isocyanurate,
1,3.5-) lis(3-hydroxy-2,6-nomethyl-4-isobutyl-pencyl)in cyanurate,
Particularly preferred is a combination with 1.3.5'-1-lis(3-hydroxy-2,6-nomethyl-4-tert-butyl-pencyl)isocyanurate). The addition of these stabilizers to polyolefin resins, particularly polyzolopyrene (I) is preferably 0.05 to 0.3 parts by weight in the case of hindered amine compounds per 100 parts by weight of polyglobylene.
It is 1 to 0.2 parts by weight.

Also, 1,3,5-tris(3-hydroxy-2,6-
methyl-4-alkyl-pentyl) isocyanurate (hereinafter referred to as phenolic antioxidant) is 0.01 to 0.
．． 0.04 parts by weight, preferably 0.02 to 0.03 parts by weight.

[C] The hindered amine compound [I] described in [B] above and the phenol-phosphite compound CID (
A compound in which the hydroxyl group of hindered phenol has been converted to a phosphite ester. For example, 1.1.3-tris(2-methyl-4-di-tridecylphosphite-5
-t-butylphenyl)butane, 4,4'-butylidene-bis(3-methyl-6-t-butylphenyl-twotridecyl) phosphite, tris(2,4-sort-t-butylphenyl) phosphite, etc.) and /or tetrakis(2,4-not-butylphenyl)-4,4'-
A combination of biphenylene diphosphonite [■]. The amount of these stabilizer compounds (1), [■] and [l11) added to the polyolefin resin is 10
The amount of compound [1] is 0.05 to 0.3 parts by weight, preferably 0.1 to 0.2 parts by weight, relative to 0 parts by weight of compound [l
D or (III) is 0.01 to 0.3 parts by weight, preferably 0.03 to 0.15 parts by weight.

Examples of this invention will be described below.

Example 0.0% of a hindered amine antioxidant was added to polynolopyrene.
A syringe barrel having the shape shown in FIG. 1 was injection molded. This outer cylinder had a wall thickness of 1.0. The total capacity is 10CC.

This injection barrel was irradiated with γ-rays of 2.7±0.2 Mrad at the temperatures shown in Table 1 below, and then heated at 80° C. for one week. After that, heat at 25°C for 120. ! A weight No. 9 was dropped from above and the height at which a crack appeared was measured. Table 1 shows the results.
Also listed in

Table 1 As seen from Table 1, the medical device obtained according to the present invention retains 90% or more of its initial impact strength. The syringe barrel obtained in this example did not cause any problems during actual use.

■Specific Effects of the Invention As described above, according to the present invention, medical devices at least partially formed of polyolefin resin can be
During radiation sterilization, R-ray sterilized medical instruments that maintain 90% or more of their initial strength characteristics can be obtained by simply irradiating gamma rays at 0°C to 5°C. Therefore, it is not necessary to take special measures such as increasing the thickness of the 19 l) olefin resin or adding an antioxidant to it, which is very advantageous in terms of production.

FIG. 1 is a cross-sectional view of a syringe including a syringe barrel as an example of a device.

11...Outer cylinder body, 11tL...Chee/4' part, 1
2...Flange part, 14...Gasket, 15...
・Grand Tsuya-O

Claims (4)

[Claims] (1) When sterilizing medical instruments by fer#j irradiation, the γ-ray irradiation is reduced to 0 to 100%. A method for manufacturing a gamma ray sterilized medical device, characterized in that the reduction in the initial strength characteristics of the polyolefin resin part is suppressed to less than 10 times by carrying out the process at a temperature of 5°C. (2) The manufacturing method according to claim 1, wherein the polyolefin resin is polypropylene. (3) Is the entire medical equipment yi? The manufacturing method according to claim 1 or 2, which is formed of an IJ olefin resin. (4) The manufacturing method according to claim 1, 2, or 3, wherein the irradiation dose of r-rays is 2.5 to 4 Mrad.