JPH0518343B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a halogen-containing resin composition having excellent resistance to radiation, particularly gamma rays. Molded products of halogen-containing resin are sterilized and used for medical instruments such as syringes and blood bags, as well as packaging materials. [Prior Art] Conventionally, boiling or sterilization using ethylene oxide gas has been used as a sterilization method. However, the boiling method is unsuitable for resins that are unstable to heat.
Drying is required to remove residual moisture from the article, and methods using ethylene oxide each have drawbacks in terms of environmental hygiene, such as gas toxicity, removal of residual gas, and disposal. In place of these methods, sterilization methods using radiation, particularly gamma rays, have been proposed, which can be carried out at low temperatures, dry, and at relatively low cost. However, when the resin is irradiated with gamma rays, the resin changes color to yellow or brown. [Problems to be solved by the invention] Therefore, in order to prevent discoloration of the resin due to γ rays,
Known antioxidants such as hindered phenol compounds, hindered amine compounds, and dialkylthiodicarboxylic acid esters have been used, but they are not sufficient to prevent discoloration due to radiation exposure, and other compounds are added to the above antioxidants. Such efforts have been made. However, to date, it has not been possible to obtain products of quality and performance that are necessarily satisfactory. [Means for solving the problem] As a result of various studies, the present inventors have found that adding one or more thioalcohol compounds to a halogen-containing resin is effective in preventing discoloration caused by γ-ray irradiation. This discovery led to the present invention. That is, the present invention relates to a gamma ray-resistant halogen-containing composition characterized in that 0.01 to 5 parts by weight of a thioalcohol compound is added to 100 parts by weight of a halogen-containing resin. Examples of the halogen-containing resin used in the present invention include halogenated vinyl homopolymers such as vinyl chloride resin, vinyl bromide resin, vinylidene chloride resin, and post-chlorinated vinyl chloride resin, as well as vinyl halides and other monomers, For example, vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, and vinyl stearate, α of ethylene, propylene, etc.
-Olefins, methyl acrylate, methyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate,
Acrylic acid esters and methacrylic acid esters such as 2-ethylhexyl methacrylate, stearyl acrylate, stearyl methacrylate, unsaturated acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, methyl vinyl ether, cetyl vinyl ether, etc. Vinyl ethers, styrene, α-methylstyrene,
Examples include copolymers formed by polymerizing with one or more comonomers such as acrylonitrile, vinylidene chloride, and thermoplastic polyurethane elastomers (see Japanese Patent Publication No. 60-30688). It may be used in combination with a halogenated vinyl homopolymer. In addition, halogen-containing resins include acrylonitrile/butadiene/styrene copolymers, methyl methacrylate/butadiene,
Styrenic copolymer, methyl methacrylate/acrylic rubber/styrene copolymer, ethylene/vinyl acetate copolymer, ethylene/vinyl acetate/carbon monoxide copolymer, styrene/acrylonitrile copolymer, chlorinated polyolefin, poly It is also possible to blend one or more of methyl methacrylate, polyalkyl acrylate, acrylonitrile/styrene/chlorinated polyethylene graft polymer, and the like. Examples of the thioalcohol compound added in the present invention include 2-mercaptoethanol, 2-mercapto-2,2'-dimethylethanol, 1,2
-dimercaptoethane, 1-mercapto-2-propanol, 3-mercapto-1,2-propanediol, 1,2-mercaptopropane, 1,3
-dimercaptopropane, 2,3-dimercapto-1-propanol, 4-mercapto-1,3-
Butanediol, 1,4-dimercaptobutane,
1,4-dimercapto-2,3-butanediol, 1,6-dimercaptohexane, octylmercaptan, decylmercaptan, 2-hydroxydecylmercaptan, 1,10-dimercaptodecane, dodecylmercaptan, 2-hydroxydodecylmercaptan, Tetradecyl mercaptan, 2-hydroxytetradecyl mercaptan,
hexadecyl mercaptan, 2-hydroxyhexadecyl mercaptan, octadecyl mercaptan, 2-hydroxyoctadecyl mercaptan,
Butyl-2-hydroxy-3-mercaptoether, triethylene glycol dimercaptan, trimethylolpropane trismercaptoacetate, trimethylolpropane bismercaptoacetate, trimethylolpropane monomercaptoacetate, ethylene glycol bismercaptoacetate, 1,4-butanediol Bismercaptoacetate, ethylene glycol bis β-mercaptopropionate, 1,4-butadiol bis β-mercaptopropionate, trimethylolpropane tris β-mercaptopropionate, trimethylolpropane bis β-mercaptopropionate, Trimethylolpropane mono-β
-Mercaptopropionate, pentaerythritol tetrakis β-mercaptopropionate,
Pentaerythritol tris β-mercaptopropionate, pentaerythritol bis β-mercaptopropionate, pentaerythritol mono β-mercaptopropionate, pentaerythritol tetrakis mercaptoacetate, pentaerythritol tris mercaptoacetate,
Pentaerythritol bismercaptoacetate, pentaerythritol monomercaptoacetate, 1,4-butanediol mono-β-mercaptopropionate, 1,4-butanediol monomercaptoacetate, ethylene glycol mono-β-mercaptopropionate, ethylene glycol monomercapto Acetate, propylene glycol bis-mercaptopropionate, propylene glycol bis-mercaptoacetate, propylene glycol mono-β-mercaptopropionate, propylene glycol monomercaptoacetate, and the like. The amount of the thioalcohol compound added to the above halogen-containing resin is 0.01 to 5 parts by weight per 100 parts by weight of the resin.
Parts by weight. The composition of the present invention may optionally contain an organic tin stabilizer, a metallic soap stabilizer, an epoxy compound, an organic phosphorus compound, an organic nitrogen stabilizer, zeolites, hydrotalcites, a polyhydric alcohol, an antioxidant, and ultraviolet light. Absorbents, plasticizers, lubricants, etc. can be added. The halogen-containing resin composition of the present invention is mixed in a suitable mixing device such as a Henschel mixer, and then molded by a processing method such as extrusion molding, injection molding, blow molding, or calendar molding, and the resulting molded product is exposed to gamma rays.
The article can be sterilized by irradiation to a radiation dose of 0.5 to 7 megarads. [Function] The halogen-containing resin composition of the present invention greatly reduces yellowing due to γ-ray irradiation due to the action of the thioalcohol compound, and does not impair safety and hygiene, so it can be used in medical instruments, food packaging materials, and containers. It can be used for purposes such as. [Example] Next, the present invention will be explained with reference to Examples, where parts in the Examples indicate parts by weight. Example 1 100 parts of vinyl chloride resin (Kanevinyl S-1008, manufactured by Kanebuchi Kagaku Co., Ltd.), 3 parts of the thioalcohol compound shown in Table 1 below, and 0.2 parts of a lubricant (WaxE, manufactured by Hoechst Co., Ltd.)
% and the thickness with a mixing roll at 170℃
A 0.5 mm sheet was prepared, and two sheets were stacked to form a press plate at 180°C. Each press plate was irradiated with gamma rays using a cobalt-60 source to a dose of 3 megarads. The hue after γ-ray irradiation is measured using a fully automatic colorimeter Color Ace TC-P.
(manufactured by Tokyo Denshokusha). The change in hue was expressed as ΔE. The results are shown in Table 1.

[Table] Example 2 Vinyl chloride resin (Kanevinyl S-1007, manufactured by Kanebuchi Kagaku Co., Ltd.), post-chlorinated vinyl chloride resin (Kanevinyl H-516S, manufactured by Kanebuchi Chemical Co., Ltd.), chlorinated polyethylene resin (Daiso Raku H) -135, manufactured by Osaka Soda Co., Ltd.), vinyl chloride/ethylene copolymer (VE-H,
(manufactured by Tokuyama Sekisui Chemical Co., Ltd.), ethylene/vinyl acetate/vinyl chloride copolymer (NPFS-5, manufactured by Toyo Soda Co., Ltd.)
Or polyurethane/vinyl chloride copolymer (GC
#41, manufactured by Denki Kagaku Kogyo Co., Ltd.) for 100 parts of each resin.
5 parts of mercapto-1,3-butanediol and 0.2 parts of a lubricant (WaxE) were added, and a sheet with a thickness of 0.5 mm was prepared using a mixing roll at 170°C, and ΔE was measured in the same manner as in Example 1. The results are shown in Table 2.

[Table] Example 3 Vinyl chloride resin (Kanevinyl S-1008) 100
and methyl methacrylate/butadiene/styrene copolymer (Kane Ace B-31, manufactured by Kanebuchi Kagaku Co., Ltd.),
Methyl methacrylate/acrylic rubber/styrene copolymer (METABLEN W-300, manufactured by Mitsubishi Rayon Co., Ltd.), ethylene/vinyl acetate copolymer (SOREBLEN BH, manufactured by Nippon Gosei Kagaku Co., Ltd.), ethylene/vinyl acetate/carbon monoxide copolymer Combine (Elvaloy 741, manufactured by Dupont) or polymethyl methacrylate (Metablen P-551, manufactured by Mitsubishi Rayon) in the number of parts listed in Table 3, 1 part of 1,4-dimercapto-2,3-butanediol, and a lubricant (WaxE). ) was added to form a sheet with a thickness of 0.5 mm using a mixing roll at 170°C, and ΔE was measured in the same manner as in Example 1. The results are shown in Table 3.

〔Effect of the invention〕

As is clear from the ΔE after γ-ray irradiation in Examples 1 to 3 above, in the present invention, if a thioalcohol compound is added to the halogen-containing resin, γ
Discoloration caused by radiation exposure can be extremely reduced, making sterilization easier without impairing the quality of the resin.

Claims (1)

[Claims] 1. A gamma ray-resistant halogen-containing resin composition, characterized in that 0.01 to 5 parts by weight of a thioalcohol compound is added to 100 parts by weight of the halogen-containing resin.