JPS6157784B2 - - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to molded articles that are sterilized by radiation and are particularly suitable as medical instruments. More specifically, the present invention relates to a molded article suitable for radiation sterilized medical instruments, which is made of a composition containing a propylene polymer and a nucleating agent. Due to its rigidity and impact strength, propylene polymers are widely used in medical instruments, especially disposable medical instruments such as syringes, needle bases, infusion/blood transfusion sets, and blood sampling instruments. Prior Art and Problems Because propylene polymers have crystallinity, the transparency of molded products is poor, and in order to improve this, nucleating agents are added. However, conventionally used nucleating agents, such as 1,3,2,4-dibenzylidene-sorbitol, decompose when exposed to radiation, emit an unpleasant odor, and also alter the surface of the product.
Molded articles made from propylene polymer and containing the above-mentioned nucleating agent were unsuitable for radiation sterilization. OBJECTIVES OF THE INVENTION Accordingly, an object of the present invention is to provide a molded article suitable for a medical device made of a propylene polymer that does not generate an unpleasant odor or change the surface of the product even when irradiated with radiation. That is, the present invention provides a molded article suitable for medical instruments that maintains its transparency even after radiation sterilization and satisfies all safety and hygiene issues such as toxicity and odor generation. The purpose is to DETAILED DESCRIPTION OF THE INVENTION The present invention consists of molded articles described in each of the following items 1 to 7. (1) Molding with improved decomposition odor, characterized by being made of a composition containing 0.01 to 0.4 parts by weight of a compound represented by the following formula [] as a nucleating agent in 100 parts by weight of a propylene polymer, and sterilized by radiation. Goods. In the above formula, R ₁ and R ₂ have 1 to 8 carbon atoms.
represents an alkyl group, an alkoxy group, a hydroxyl group, or a halogen atom, m and n each independently represent an integer of 1 to 3, and l represents 0 or 1. (2) The molded article according to item 1 above, wherein the amount of the nucleating agent is 0.05 to 0.3 parts by weight. (3) The first above, wherein the nucleating agent is 1,3,2,4-di(p-methylbenzylidene) sorbitol.
The molded article according to item 1 or 2. (4) The molded article according to any one of paragraphs 1 to 3 above, wherein the molded article is an injection molded article. (5) No. 4 above, wherein the injection molded product is a medical device.
Molded products described in Section. (6) The molded article according to item 4 above, wherein the medical device is a syringe barrel, a base of a hypodermic needle, an infusion or blood transfusion set, or a blood sampling device. (7) The molded article according to any one of the above items 1 to 6, wherein the radiation sterilization is γ-ray or X-ray sterilization. As described above, the molded article of the present invention is composed of a composition containing 100 parts by weight of a propylene polymer and 0.01 to 0.4 parts by weight of the compound represented by the above formula [] as a nucleating agent. The propylene polymer referred to in the present invention includes a polymer of propylene alone, that is, a propylene homopolymer, a propylene-ethylene copolymer having an ethylene content of 5% by weight or less, and a propylene homopolymer and a propylene-ethylene copolymer. This includes blends of ethylene and ethylene in which the ethylene content is 5% by weight or less. Copolymerization may be either random or block, but random copolymerization is preferred. Propylene homopolymer has a high rigidity in molded products, so when manufacturing medical devices that require flexibility, it is necessary to copolymerize a small amount of ethylene to control the rigidity of the molded product, as described above. is desirable. The appropriate melt flow index (MFR) of the polymer is approximately 5 to 50 g/10 min, depending on the type of product. For example, for the outer barrel of a syringe, it is desirable to have an ethylene content of 1.5 to 4.0 weight percent and an MFR of 10 to 30, and for the syringe needle hub and the octopus tube of the infusion set, it is desirable to have an ethylene content of 0 to 4.0 weight percent and an MFR of 5 to 30. is desirable. Suitable examples of the compound represented by the formula [] used as a nucleating agent include, in the formula [], R ₁
and R ₂ is a lower alkyl group such as methyl, ethyl, propyl, isopropyl, n-butyl, a lower alkoxy group such as methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, and a halogen atom such as chlorine or bromine. Or a compound having a hydroxyl group can be mentioned. The substitution positions of R ₁ and R ₂ are not particularly limited, and they may be substituted at any position on the benzene ring, but the p-position is most preferred. The amount of the nucleating agent blended is 0.01 to 0.4, preferably 0.05 to 0.3 parts by weight per 100 parts by weight of the propylene polymer. The thus obtained composition of the present invention may contain other additives, such as antioxidants, light stabilizers, ultraviolet absorbers, antistatic agents, neutralizing agents, and dispersants, to the extent that the objects and effects of the present invention are not impaired. , pigments, etc. can be added. A molded article suitable for the medical device of the present invention is produced by melt-kneading the above composition in a kneading machine such as a roll, a Banbury mixer, a Brabender plastograph, or an extruder, and then molding it by injection molding or the like. Generally, each additive is blended into a powdered propylene polymer, mixed in a suitable mixing device such as a mixer, and then melted and kneaded in an extruder to form pellets, or directly injected without pelletizing. Shape. It is appropriate that the injection molded product be packaged with a polyester polyethylene laminate film or the like and sterilized by radiation before being shipped as is. As the radiation, gamma rays or X-rays are used, preferably gamma rays from a cobalt-60 ray source. The irradiation amount is 5 megarads or less, preferably 2 to 4 megarads, and excessive irradiation causes deterioration of the molded product. Irradiation may be performed in vacuum, in an inert gas such as nitrogen, or in air, and is carried out at a temperature of 80° C. or lower, preferably room temperature or lower. Examples of radiation sterilized medical instruments obtained by the present invention include, but are not limited to, syringe barrels, injection needles, syringe bases, infusion/blood transfusion sets, blood sampling instruments, etc. do not have. Next, the present invention will be explained in more detail with reference to Examples and Comparative Test Examples. Example: To 100 parts by weight of propylene-ethylene random copolymer powder with an ethylene content of 2.5% by weight,
After blending the additives shown in Table 1 and blending using a super mixer, granulation is performed using a 50 mm diameter extruder, and the resulting pellets are put into an injection molding machine and molded into a syringe barrel with an internal capacity of 10 ml. did. The sample was wrapped in 20μ polyethylene terephthalate packaging material.
A cobalt-60 source was used to irradiate 2.5 megarads. 30 days after irradiation, the package was opened and the presence or absence of odor was determined.
The results are shown in Table 1.

[Table] Furthermore, when 6 mg of polydimethylsiloxane was applied to the syringe barrel and the surface of the sample was observed after 30 days of irradiation with 2.5 megarads, no change was observed in the sample to which the nucleating agent of the present invention was added. , the surface of those to which EC1 was added became hydrophilic and repelled silicone. The contact angle between the sample surface and the silicone droplet was as shown in Table 2. That is, a product containing EC-1 whose contact angle with silicone increases over time means that a hydrophilic substance has bled onto the surface.

[Table] Effects of the Invention According to the present invention, a propylene polymer molded article that can be commercially subjected to radiation sterilization is provided. That is, according to the present invention, first, a radiation sterilized molded article with excellent transparency is provided. Further, according to the present invention, a molded article that does not emit unpleasant odor due to radiation sterilization is provided. A nucleating agent is blended into propylene polymer products as a clarifying agent, but some of the nucleating agents conventionally used decompose when irradiated with radiation and emit an unpleasant odor. The nucleating agent used in the present invention does not generate any unpleasant odor. Further, according to the present invention, a molded article whose surface condition does not change even after radiation sterilization is provided. Some of the nucleating agents conventionally used are decomposed by radiation irradiation and change the properties of the surface of the product, but the nucleating agent used in the present invention does not cause such changes.

Claims (1)

[Claims] 1. A decomposition odor-free composition comprising a composition containing 0.01 to 0.4 parts by weight of a compound represented by the following formula [] as a nucleating agent in 100 parts by weight of a propylene polymer, and which is sterilized by radiation. Improved molded product. In the above formula, R ₁ and R ₂ represent an alkyl group or alkoxy group having 1 to 8 carbon atoms, a hydroxyl group, or a halogen atom, m and n each independently represent an integer of 1 to 3, and l represents 0 or 1. . 2. The molded article according to claim 1, wherein the amount of the nucleating agent is 0.05 to 0.3 parts by weight. 3. The molded article according to claim 1 or 2, wherein the nucleating agent is 1,3,2,4-di(p-methylbenzylidene) sorbitol. 4. The molded product according to any one of claims 1 to 3, wherein the molded product is an injection molded product. 5. The molded article according to claim 4, wherein the injection molded article is a medical device. 6. The molded article according to claim 5, wherein the medical device is a syringe barrel, a base of a syringe needle, an infusion or blood transfusion set, or a blood collection device. 7. The molded article according to any one of claims 1 to 6, wherein the radiation sterilization is γ-ray or X-ray sterilization.