JPH0268068A - Medical polycarbonate molding for sterilization by irradiation of radiation - Google Patents

Abstract

PURPOSE:To decrease the yellowing of the molding against irradiation of gammarays in the air, particularly under non-oxygen and to provide the molding which is useful as a case, etc., of an artificial dialyzer, artificial lung, transfusion set, etc., to be subjected to radiation sterilization by using the molding for which an arom. polycarbonate resin contg. the constituting unit derived from bisphenol halide. CONSTITUTION:This molding for polycarbonate treatment for steilization by irradiation of radiations in an atmosphere contg. substantially no oxygen consists of the arom. polycarbonate resin contg. the arom. polycarbonate polymer or oligomer having the constituting unit derived from the bisphenol halide in the molecular chain. The molding for polycarbonate treatment for sterilization by irradiation of radiations consists of the arom. polycarbonate resin contg. 0.1 to 10wt.%, more preferably 0.5 to 5wt.% halogen.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a medical polycarbonate molded article with excellent radiation resistance. The polycarbonate molded article of the present invention has substantially little yellowing due to radiation irradiation in an oxygen-free environment, so it is useful for medical equipment, etc. for sterilization by radiation irradiation in an oxygen-free environment.

[Conventional technology and its problems]

Aromatic polycarbonate resins have high impact resistance, heat resistance, transparency, and are highly safe, so they are often used as medical products.

When used in these medical products, high-pressure steam sterilization and ethylene oxide gas (EOG) sterilization have conventionally been used. However, the steam sterilization method has some drawbacks, such as incomplete sterilization and the need for a drying process after sterilization. Additionally, COG sterilization has problems such as the toxicity of BOG remaining in the material to be sterilized.

Therefore, recently, attention has been focused on sterilization methods that involve irradiation with radiation (gamma rays inside the shell), which can be carried out relatively inexpensively, at low temperatures, and in a dry manner. Sterilization without oxygen is also attracting attention.

However, when polycarbonate resin molded articles conventionally used for these purposes are irradiated with radiation, the resin decomposes, causing yellowing and reducing product value. Furthermore, this tendency was significantly increased when the test was carried out under substantially no oxygen conditions.

[Means to solve the problem]

As a result of intensive studies to develop medical products made of polycarbonate resin that are suitable for sterilization by radiation irradiation, the present inventors have developed an aromatic polycarbonate containing structural units derived from halogenated bisphenols in the molecular chain. It has been discovered that the molded product made using this method can solve this problem.

Furthermore, they discovered that the molded article becomes less colored when irradiated with radiation in a substantially oxygen-free environment, leading to the completion of the present invention.

That is, the present invention is a method of sterilizing aromatic polycarbonate polymers containing structural units derived from halogenated bisphenols in their molecular chains or aromatic polycarbonate resins containing oligomers by irradiation in a substantially oxygen-free atmosphere. The halogen content of the aromatic polycarbonate resin is 0.1 to 10% by weight, more preferably 0.1 to 10% by weight.
This is a polycarbonate medical molded article for radiation sterilization made of an aromatic polycarbonate resin with a 5 to 5% fluorescent content.

The configuration of the present invention will be explained below.

First, the aromatic polycarbonate polymer or olicomer containing structural units derived from halogenated bisphenols in the molecular chain of the present invention is produced by using halogenated bisphenols as part or all of the dihydric phenol. Those which are conventionally known per se and which are preferably used in the present invention include (a) aromatic polycarbonate copolymer using halogenated bisphenols as a part of dihydric phenol; (b) halogen Aromatic polycarbonate homo-oligomer using bisphenols as dihydric phenol, (C),
Examples include aromatic polycarbonate co-olicomers that use halogenated bisphenols as part of the dihydric phenol. In addition, halogenated bisphenols are also effective in preventing discoloration due to radiation exposure, but they have low thermal stability and are low molecular weight monomers, which increases the possibility of elution. It is not very preferable for this purpose.

The aromatic polycarbonate resin of the present invention is not particularly limited as long as it contains an aromatic polycarbonate polymer or oligomer containing a structural unit derived from the above-mentioned halogenated bisphenol in its molecular chain,
Specifically, ■, the above (a) alone, ■, a composition of the above (a) and the above (b), (C), or an aromatic polycarbonate oligomer derived from a halogen-free dihydric phenol. , ■ Aromatic polycarbonate resin derived from dihydric phenol with no residual halogen and the above (a
), (b) or (C).

Here, the above-mentioned aromatic polycarbonate polymer or oligomer used in the present invention is produced by a known production method, and the halogenated bisphenols include bis(4-hydroxy-3,5-dibromophenyl)methane, 2 .2-bis(4-hydroxy-3,5-dibromophenyl)propane, 4,4'-dihydroxy-3,3'
, 5.5°-tetrabromodiphenyl sulfide,
2.2-bis(4-hydroxy-3,5-dichlorophenyl)furopane, 2,2-bis(4-hydroxy-3-
bromophenyl)propane, bis(4-hydroxy-3
-chlorophenyl)methane, bis(4-hydroxy-3
, 5-dichlorophenyl) methane, and bis(4-hydroxy-3-bromophenyl) methane. Examples of halogen-free dihydric phenols include bis(4-hydroxyphenyl)methane and bis(4-hydroxyphenyl) ether. , bis(4-hydroxyphenyl) sulfone, bis(4-hydroxyphenyl) sulfoxide, bis(4-hydroxyphenyl) sulfide, bis(4-
hydroxyphenyl)ketone, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 1,1-bis( 4-hydroxyphenyl)cyclohexane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, bis(4-hydroxy An example is phenyl)diphenylmethane. In addition, terminal capping agents (molecular weight regulators) include, in addition to normal phenol, pt-butylphenol, tribromophenol, etc., long-chain alkyl-substituted phenols such as octylphenol, nonylphenol, laurylphenol, palmitylphenol, and stearylphenol;
Hydroxybenzoic acid long chain alkyl esters such as octyl hydroxybenzoate, lauryl hydroxybenzoate, nonyl hydroxybenzoate, and stearyl hydroxybenzoate; octyl ether phenol (= octyloxyphenol), nonyl ether phenol, lauryl phenol, palmityl Long-chain alkyloxyphenols such as ether phenol, octadecyloxyphenol, and dobusyloxyphenol; aliphatic acid chlorides such as capric acid chloride, lauric acid chloride, myristic acid chloride, balmitic acid chloride, stearic acid chloride, and cerotic acid chloride; Illustrated.

Further, the aromatic polycarbonate polymer or oligomer of the present invention containing or not containing a structural unit derived from a halogenated bisphenol in its molecular chain is produced using the above-mentioned components, but the branching agent is added to the above-mentioned component. It can also be used in combination in an amount of 0.01 to 3 mol, particularly 0.1 to 1.0 mol, per 100 mol of the dihydric phenol compound to form a branched polycarbonate. Such branching agents include phloroglycin, 2,6-cymethyl-2.
4.6-)li(4-hydroxyphenyl)hebutene-3,4,6-dimethyl-2.4.6-)li(4-
hydroxyphenyl)hebutene-2,1,3,5-)li(2-hydroxyphenyl)penzole, 1.1.1
- ) Li(4-hydroxyphenyl)ethane, 2.6
-bis(2-hydroxy-5-methylbenzyl)-4-
Methylphenol, α, α1. polyhydroxy compounds exemplified by α″-tri(4-hydroxyphenyl)-1,3,5-)liisoprobylbenzene, and 3
．． Examples include 3-bis(4-human, waxyaryl)oxindole (=isatin bisphenol), 5-chloroisatin, 5.7-dichloroisatin, 5-bromiisatin, and the like.

The polycarbonate resins suitably used for producing the polycarbonate medical molded article for radiation sterilization of the present invention include (1), 2.2-bis(4-hydroxyphenyl)propane (=bisphenol A) and 2.2-bis(4-hydroxyphenyl)propane (=bisphenol A). - screw (4
-hydroxy-3,5-dibromophenyl)furopane (
= copolymerized polycarbonate resin with tetrabromobisphenol A), (2), composition of bisphenol A polycarbonate resin and the copolymerized polycarbonate resin of (1), (3), bisphenol A polycarbonate resin and a pt terminal Examples include a polycarbonate oligomer of tetrabromobisphenol A capped with butylphenol, tribromophenol, etc., or a composition of copolymerized polycarbonate oligomer of bisphenol A and tetrabromobisphenol A with end capping. If the content of halogen atoms in the medical molded article is too low, it will not be effective in suppressing yellowing due to radiation exposure, and if it is too high, it will lead to a decrease in mechanical properties, heat resistance, etc., which is not preferable. The amount of halogen atoms in this medical molded article is 0.1
-10% by weight, preferably 0.5-5% by weight.

The conditions for manufacturing the polycarbonate medical molded article for radiation sterilization of the present invention by molding the above aromatic polycarbonate resin include the viscosity average molecular weight of the aromatic polycarbonate resin used, the type of dihydric phenol used,
Although it varies depending on the type of terminal capping agent, the content of halogenated bisphenol, etc., it is usually manufactured by injection molding at 260 to 340°C.

The present invention is as described above, but in preparing the molding material, heat stabilizers, antioxidants, colorants,
Various additives such as lubricants and mold release agents can be added.

〔Example〕

Hereinafter, a detailed explanation will be given using synthesis examples, examples, and comparative examples. In addition, "%" and "part" in Examples etc. are based on weight unless otherwise specified.

Synthesis Example 1 Bisphenol A (hereinafter referred to as B) was added to the ioo z reaction vessel.
PA) 8.1kg, Tetrabromobisphenol A (hereinafter referred to as TBA) 750g, 9% caustic soda aqueous solution 42A, methylene chloride (hereinafter referred to as MC)
Add 30β and stir while keeping the temperature at about 20℃.
4.2 kg of phosgene was blown in over 30 minutes.

Then, 209 g of p-tert-butylphenol (hereinafter referred to as PTBP) dissolved in MC2j2 and 7 g of ) ethylamine (hereinafter referred to as TEA) were added, and the mixture was stirred for about 1 hour and then polymerized.

The polymerization solution was separated into an aqueous phase and an organic phase, and the organic phase was neutralized with phosphoric acid. After repeating water washing until the pH of the washing solution became neutral, 35β of isopropanol was added and the polymerization was precipitated. The precipitate is filtered and then dried to produce a white powdery polycarbonate copolymer (hereinafter referred to as CPC).
(denoted as I) was obtained.

The viscosity average molecular weight of CPCI was 25.000, and the bromine (Br) content calculated from the amount of reaction monomers after polymerization was 4.46%.

Synthesis Example 2 In a 1001 reaction vessel, 9 kg of Tr3A, 9% aqueous sodium hydroxide solution 30β, 10 A of water, MC23
β, TEA 6d were added, and 2.5 kg of phosgene was blown in over 30 minutes while stirring and keeping the temperature at about 20°C.

Then, 970 g of PTBP dissolved in MC10β,
50 rnl of TEA was added and the mixture was stirred for about 1 hour to continue polymerization.

Thereafter, the organic layer was purified in the same manner as in Synthesis Example 1, and then the solvent was evaporated to dryness to form a white powder polycarbonate homo-oligomer (hereinafter referred to as HOPC2) was obtained.

Synthesis example 3 100! In a reaction vessel, 9.8 kg of TBA and 30 kg of water
Add 11MC37β, 9% caustic soda aqueous solution 4β, and 4.9g of triethylbenzylammonium chloride.
While stirring, 3.8 kg of phosgene was bubbled in over 30 minutes while maintaining the pH of the mixture at 11.0-11.8 and the temperature at about 20°C. p) Adjustment of I with 35% hydroxide l-IJ
This was done by adding an aqueous solution of aluminum.

Then, the reaction mixture was transferred to a 1501 reaction vessel and 9% hydroxylated) IJum aqueous solution 19A, BPA 2.
2kg, PTBP 1.65kg and 15β MC
450 g of TEA was added, and the mixture was stirred for about 1 hour to allow polymerization.

Thereafter, in the same manner as in Synthesis Example 2, a white powdery polycarbonate copolymer (hereinafter referred to as C0PC3) having an average degree of polymerization of 5 and a Br content of 39.7% was obtained.

Examples 1 to 5 and Comparative Example 1 Copolycarbonate resin obtained in Synthesis Example 1 alone or aromatic polycarbonate resin (trade name: Nipiron S-30
00 (manufactured by Mitsubishi Gas Chemical Co., Ltd.) and the polycarbonate polymers or oligomers obtained in Synthesis Examples 1 to 3 were mixed in a tumbler at the ratios listed in Table 1, and extruded using a vent-type extruder with a shaft to form pellets. And so.

Using this pellet, an injection molding machine (manufactured by Sumitomo Heavy Industries)
A molded piece of 50 x 60 mm and 3.2 mm thick was molded using Neopine l-110/45) at a resin temperature of 300°C, a mold temperature of 80°C, and an injection pressure of 1.200 kg/cnf.

This molded piece was irradiated with 2.5 megarads of gamma rays in the air and in a sealed molded product (trade name: Ageless, manufactured by Mitsubishi Gas Chemical) with an oxygen absorber (product name: Ageless, manufactured by Mitsubishi Gas Chemical). , its yellowing degree (Y, 1.) change (ΔY,
1. ) is a color difference meter made by Suga Test Instruments Ga! Measured using J-3-CI+. The results are shown in Table 1.

Table 1 [Operations and Effects of the Invention] As described above, a molded article using an aromatic polycarbonate resin containing a structural unit derived from a halogenated bisphenol of the present invention can be used not only in the air but also in a particularly substantial manner. There is little yellowing when exposed to T-rays in an oxygen-free environment.

Therefore, it is useful as cases for artificial dialyzers, artificial lungs, blood transfusion sets, etc. that perform radiation sterilization (generally γ-ray sterilization).

Patent applicant: Mitsubishi Gas Chemical Co., Ltd.

Claims (1)

[Claims] 1. Radiation irradiation in a substantially oxygen-free atmosphere consisting of an aromatic polycarbonate polymer containing structural units derived from halogenated bisphenol in its molecular chain or an aromatic polycarbonate resin containing oligomers. Polycarbonate medical molded products for sterilization. 2. The polycarbonate medical molded article for radiation sterilization according to claim 1, wherein the aromatic polycarbonate resin has a halogen content of 0.1 to 10% by weight. 3. The polycarbonate medical molded article for radiation sterilization according to claim 1, wherein the aromatic polycarbonate resin has a halogen content of 0.5 to 5% by weight.