JPS6023622B2 - Vinyl chloride resin medical equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a medical device made of vinyl chloride resin subjected to gamma line sterilization.

Conventionally, when vinyl chloride resin is used for medical devices, sterilization using ethylene oxide gas (hereinafter referred to as EOG sterilization) is usually performed as stipulated by the Japanese Pharmacopoeia Law.

However, it cannot always be said that it is a good sterilization method due to environmental problems in the vicinity of the sterilization room when EOG sterilization is performed, as well as problems such as adhesion of ethylene oxide gas to medical instruments that have been sterilized by EOG. In addition to EOC sterilization, there is a method of sterilizing by irradiating gamma rays from a source containing a radioactive isotope (hereinafter referred to as y-ray sterilization).

Y-ray sterilization usually uses a radiation source containing oCo or 137Cs, and sterilizes by adjusting the total irradiation dose depending on the material, property, or contamination status of the item to be sterilized.
Normal medical equipment is 2. The maximum amount is 8 Mrad in Norishin AD. However, when medical tools made of vinyl chloride resin are sterilized with Y-rays, they turn pale yellow and their quality deteriorates. For this reason, resins that can withstand Y-ray sterilization, such as polyethylene, polypropylene, or ethylene-vinyl acetate, are used for medical instruments that undergo Y-ray sterilization.

However, since these resins do not have the same transparency and flexibility as vinyl chloride, they are not suitable for tubes as soft as vinyl chloride resins used in medical devices. For this reason, soft vinyl chloride resin is used for medical tools, but as mentioned above, Y-ray sterilization causes discoloration and quality deterioration, so only EOG sterilization has been used. In view of this situation, the present inventors worked diligently to develop materials that can withstand Y-ray sterilization, and as a result, a medical product molded from a composition consisting of vinyl chloride resin, a plasticizer, a higher fatty acid zinc salt compound, and a higher fatty acid salt calcium compound. After discovering the new fact that only tools can withstand Y-ray sterilization, we have completed the present invention.

The object of the present invention is to provide a medical device molded from a vinyl chloride resin composition that can withstand Y-ray sterilization and can be molded in a manner similar to that of general thermoplastic resins. The medical equipment referred to here includes blood bags, blood sets, infusion sets, artificial kidney blood circuits,
It is an artificial heart-arm blood circuit, etc., and is an assembly of various tubes, sheets or films, injection molded parts, connectors, and other parts.

That is, the present invention provides a medical device molded from a composition consisting of a vinyl chloride resin, a plasticizer, a higher fatty acid zinc salt, and a higher fatty acid calcium salt and subjected to gamma ray sterilization.

That is, the present invention is characterized by a tube molded from a composition comprising a vinyl chloride resin that does not contain antioxidants, ultraviolet absorbers, chelators, etc., a plasticizer, and stabilizers of higher fatty acid zinc and higher fatty acid calcium salt. It is a colorless and transparent medical device that is assembled from sheets, injection molded products, etc., and subjected to gamma ray sterilization.

Higher fatty acid zinc salt is a carboxylic acid salt made from C8-C22 higher fatty acids derived from animal and vegetable oils and is preferably added in an amount of 0.01% to 0.5% by weight.
The higher fatty acid calcium salt is a carboxylic acid salt made from C8-C22 higher fatty acids derived from animal and vegetable oils and fats, and is preferably added in an amount of 0.01 to 0.5% by weight.

In addition, one of the features of the present invention is that chelators such as triphenyl phosphite and BHT are added to the conventional Ca-Zn stabilizer.
It is common knowledge that anti-oxidants or ultraviolet absorbers such as Tinuvin-P are used in combination, and most products are commercially available in packs containing Ca-Zn-based stabilizers and these combination agents.

However, if these chelators, antioxidants, or ultraviolet absorbers are used in combination, the properties will deteriorate significantly, but the characteristics of the medical device of the present invention do not deteriorate even after being subjected to gamma ray sterilization. In the present invention, the expression "vinyl chloride resin" used herein refers to a vinyl chloride homopolymer or a copolymer mainly composed of vinyl chloride and a monomer copolymerizable therewith. Monomers copolymerizable with vinyl chloride include fatty acid vinyl esters, vinylidene halides, acrylic acid alkyl esters, methacrylic acid alkyl esters, acrylonitrile, alkyl vinyl ethers, styrene, and derivatives. The plasticizer used in the composition of the present invention is added to impart flexibility to the molded product, and the amount added varies depending on the molded product, but is suitably 5 to 15 parts.

Examples of such plasticizers include phthalate esters, aliphatic dibasic acid esters, phosphate esters, hydroxy polycarboxylic acid esters, fatty acid esters, polyhydric alcohol esters, epoxy plasticizers, and polyester plasticizers. Can be used.

The vinyl chloride resin composition used in the medical device of the present invention is a composition consisting of a vinyl chloride resin, a plasticizer, a higher fatty acid zinc salt, and a higher fatty acid calcium salt, and can be used as it is, but if necessary, other thermoplastic resin compositions may be used. resin, rubber, filler,
It is used by adding deer meat, processing aids, etc.

Other thermoplastic resins include ethylene vinyl acetate copolymer, chlorinated polyethylene, ABS resin, AS resin, urethane resin, acrylic resin, etc. Rubbers include NBR,
CR etc. are used.

The vinyl chloride resin used in the medical device of the present invention can be granulated and molded by the same process as the conventional vinyl chloride resin. That is, it is mixed with a plasticizer, stabilizer, etc. using a mixer such as a spar mixer blender, and then granulated using a Banbury roll, extruder, etc. Of course, even in the form of a mixed powder, the molding process is no different from that of conventional vinyl chloride resin. Granulated pellets can be injection molded and extruded in the same way as general vinyl chloride resin, and can be assembled into medical devices, and the moldability and processability are just as good as general vinyl chloride resin. However, the obtained medical devices can withstand Y-ray sterilization compared to general vinyl chloride resin. The technical content of the present invention will be explained using examples. Example weight as vinyl chloride resin: 13
00 and 1100 vinyl chloride resin, dioctyl phthalate (DOP) and epoxidized soybean oil (○-1301P manufactured by Adeka Argus) as a plasticizer, and WAX- as a lubricant.
OP (manufactured by Hoechst) or butylstearic acid, triphenylphosphite as a chelator, BHT as an antioxidant, Tinuvin-P (manufactured by Ciba-Geigy) as an ultraviolet absorber, and stabilizers as shown in Table 1. They were mixed in a spar mixer, pellets were made in an extruder, test pieces were made in a hot press, and the properties before and after y-ray sterilization were measured and are shown in Table 2.

As is clear from Table 2, no deterioration in properties was observed in the Examples, which are products of the present invention, but in the Comparative Examples, the appearance became yellowish brown, the tensile strength decreased, the hardness increased, and the arm temperature decreased. It has become higher and its characteristics have deteriorated. Table 1 (Units are parts by weight) Table 2

Claims (1)

[Claims] 1. Tubes, sheets and the like obtained by molding a composition consisting of a vinyl chloride resin that does not contain antioxidants, ultraviolet absorbers, chelators, etc., a plasticizer, and stabilizers of higher fatty acid zinc salt and higher fatty acid calcium salt. A medical device characterized by appropriately assembling injection molded products and subjecting them to gamma ray sterilization.