JPH02238049A - Polycarbonate molded article capable of being sterilized by irradiation - Google Patents

Abstract

PURPOSE:To obtain molded articles suitable for medical use requiring radiation sterilization, having improved yellowing resistance in radiation sterilization in the absence of oxygen by blending a specific aromatic polycarbonate with a specific amount of a polyalkylene glycol. CONSTITUTION:(A) A polycarbonate containing a constituent unit, derived from a halogenated bisphenol, in the molecular chain and having 0.1-10wt.% halogen content is blended with (B) 0.1-5wt.%, preferably 0.3-3wt.% polyalkylene glycol (e.g. polyethylene glycol) and, if necessary, (C) a mold release agent not containing an olefinic carbon-carbon unsaturated bond and the composition is molded.

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 virtually no yellowing due to radiation irradiation in an oxygen-free environment, so it is useful for medical devices that are sterilized by radiation irradiation in an oxygen-free environment. [Prior art 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.

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

Therefore, recently, sterilization methods that involve irradiation with radiation (generally gamma rays and electron beams), which can be carried out relatively inexpensively and at low temperatures in a dry manner, have attracted attention.
There is also interest in sterilizing the product substantially in the absence of oxygen.

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.

Further, JP-A-62-135556 discloses a composition in which yellowing caused by radiation exposure is improved by blending a polyether polyol or its alkyl ether with a polycarbonate resin. However, the rate of improvement in yellowing caused by radiation irradiation was insufficient, especially under virtually no oxygen conditions. [Means for Solving the Problems] As a result of intensive studies to develop a polycarbonate resin that can be molded into medical products suitable for sterilization by radiation irradiation, the present inventors have developed a structural unit derived from halogenated bisphenols. The invention was based on the discovery that when polyalkylene glycol is blended with an aromatic polycarbonate containing in the molecular chain, yellowing can be significantly suppressed not only in the air but also when sterilized by radiation under substantially no oxygen conditions. reached.

That is, the present invention provides a radiation sterilizable product made by molding a polycarbonate resin composition comprising an aromatic polycarbonate polymer or oligomer containing a structural unit derived from a halogenated bisphenol in its molecular chain and a polyalkylene glycol. It is a polycarbonate molded product.

Furthermore, the molded article of the present invention is characterized in that the aromatic polycarbonate resin has a halogen content of 0.1 to 10% by weight;
The blending amount of the polyalkylene glycol is 0.1 to 5% by weight, the mold release agent that improves moldability does not contain olefinic carbon-carbon unsaturated bonds, and radiation sterilization is also required. This is a polycarbonate molded article for sterilization by radiation irradiation in a substantially oxygen-free atmosphere.

The configuration of the present invention will be explained below.

First, the aromatic polycarbonate polymers or oligomers containing structural units derived from halogenated bisphenols in the molecular chain of the present invention are those produced using halogenated hisphenols 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 part of dihydric phenol (b). Aromatic polycarbonate homooligomer using halogenated bisphenols as dihydric phenol, (C)
．． Examples include aromatic polycarbonate co-oligomers using halogenated bisphenols as part of the dihydric phenol. Note that halogenated bisphenols are also effective in preventing discoloration due to radiation exposure, but
It has low thermal stability and is not very desirable.

The polyalkylene glycol of the present invention has the following general formula (
It is a compound represented by 1) and is usually obtained by polymerization of alkylene oxide.

General formula (1): L O (CHt CHR)
, 10 , polypropylene glycol, and their etherified or esterified products, which may be used alone or in combination as appropriate.

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 and polyalkylene glycol. . Specifically ■. 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; A composition obtained by blending a polyalkylene glycol with an aromatic polycarbonate resin such as a composition of an aromatic polycarbonate resin derived from a halogen-free dihydric phenol and the above (a), Φ) or (C) is available. Can be mentioned.

The above aromatic polycarbonate polymer or oligomer used in the present invention is produced by a known production method, and the halogenated bisphenol includes bis(4-hydroxy-3,5-dipromophenyl)methane, 2,2 -bis(4-hydroxy-3.5-dibromophenyl)propane, 4.4'-dihydroxy-3.3'
．． 5.5'-tetrapmodiphenyl sulfide, 2.
2-bis(4-hydroxy-3,5-dichlorophenyl)propane, 2,2-bis(4-hydroxy-3-promophenyl)propane, bis(4-hydroxy-3-chlorophenyl)methane, bis(4- Hydroxy-3,5
-dichlorophenyl)methane, bis(4-hydroxy-
Examples include 3-promophenyl)methane, and 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)broban, 2,2-bis(4- hydroxyphenyl)phthane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 2,2-bis(4-hydroxy-3
．． 5-dimethylphenyl)propane, 1,1-bis(4
-hydroxyphenyl)-1-phenylethane, bis(
An example is 4-hydroxyphenyl)diphenylmethane. In addition to the usual phenol, pt-butylphenol, and tribromophenol, terminal capping agents (molecular weight regulators) include 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;
Long chain alkyloxyphenols such as octyl ether phenol (= octyloxyphenol), nonyl ether phenol, lauryl ether phenol, balmityl ether phenol, octadecyloxyphenol, dodecyloxyphenol; capric acid chloride, lauric acid chloride, myristic acid Examples include aliphatic acid chlorides such as chloride, palmitic acid chloride, stearic acid chloride, and cerotic acid chloride.

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. o per 100 mol of dihydric phenol compound. A branched polycarbonate can also be obtained by using them together in an amount of oi to 3 mol, particularly 0.1 to 1.0 mol. Such branching agents include phloroglycin, 2,6-dimethyl-2.
4.6-Tri(4-hydroxyphenyl)heptene-
3,4,6-dimethyl-2.4.6-}-(4-hydroxyphenyl)heptene-2,1.3.5-tri(
2-Hydroxyphenyl)benzole, 1.1.1-
1-ri(4-hydroxyphenyl)ethane, 2.6-bis(2-hydroxy-5-methylbenzyl)-4-methylphenol, α. α1,α″-tri(4-hydroxyphenyl)-1.3.5-Polyhydroxy compounds exemplified by triisoprobylbenzene etc. 1) I, and 3
, 3-bis(4-hydroxyaryl)oxindole (==isatin bisphenol), 5-chloroisatin, 5.7-dichloroisatin, 5-promiisatin, and the like.

Among the above-mentioned polycarbonates, the polycarbonate resin suitably used for producing the polycarbonate molded article for radiation sterilization of the present invention is (1), 2.2-bis(4-hydroxyphenyl)propane (=bisphenol). A) copolymerized polycarbonate resin with 2.2-bis(4-hydroxy-3.5-dibromophenyl)propane (=tetrapromobisphenol A), (2), bisphenol A polycarbonate resin and the above (1) a composition with a copolymerized polycarbonate resin, (3) a bisphenol A polycarbonate resin and a polycarbonate oligomer of tetrapromobisphenol A whose terminals are capped with pt-butylphenol, tripromophenol, etc., or bisphenol A whose terminals are capped; Examples include compositions with tetrapromobisphenol 80 copolymerized polycarbonate oligomers.

Containment of halogen atoms in this molded product! (or the content of halogen atoms in the polycarbonate resin) is not preferable because if it is too small, it will not be effective in suppressing yellowing due to radiation exposure, and if it is too large, it will lead to a decrease in mechanical properties, heat resistance, etc. The amount of halogen atoms in the molded article is selected from the range of 0.1 to 10% by weight, preferably 0.3 to 5% by weight. In addition, the blending amount of polyalkylene glycol is 0.1 to
5% by weight, preferably from 0.3 to 3% by weight. If the amount added is less than 0.1% by weight, the effect of improving the degree of yellowing due to radiation irradiation is insufficient, and even if it is used in an amount exceeding 5% by weight, no improvement in the degree of yellowing can be expected; This is not preferable because the mechanical properties, heat resistance, etc. deteriorate.

Furthermore, in order to improve moldability, it is preferable to add a mold release agent or a lubricant. Such mold release agents are generally known mold release agents used for polycarbonate resins, and are not particularly limited as long as they do not substantially contain an olefinic carbon-carbon unsaturated double bond in the molecule. Specifically, stearic acid, palmitic acid,
Saturated higher fatty acids such as myristic acid, palmitic acid, behenic acid and butyl alcohol, hexyl alcohol, octyl alcohol, nonyl alcohol, lauryl alcohol, myristyl alcohol, stearyl alcohol,
Esters or partial esters with saturated alcohols such as behenyl alcohol, ethylene glycol, propylene glycol, butanediol, hexanediol, glycerin, butanetriol, pentanetriol, erythritol, pentaerythritol; paraffins, low molecular weight polyolefins, other waxes, etc. Illustrated.

The amount added is in the range of 0.01 to 3% by weight, preferably 0.1 to 1% by weight of the composition. The conditions for manufacturing the polycarbonate molded product 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 to be used, the type of dihydric phenol to be used, and the terminal capping agent. It is usually produced by injection molding at 260 to 340°C, although it varies depending on the type of ether, the type and amount of ether added, the type and amount of mold release agent added, the content of halogenated bisphenol, etc.

The radiation sterilizable polycarbonate molded article of the present invention is manufactured using a resin composition that essentially contains the above-mentioned components, but if necessary, for the purpose of improving moldability or for other purposes, it may be necessary to make the polycarbonate molded article thermostable so that it does not change in quality due to radiation irradiation. agent, antioxidant,
Coloring agents and other various additives can be added.

〔Example〕

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

Synthesis Example I Into a 1002 reaction vessel, bisphenol A (hereinafter, BP) was added.
8.1 kg, tetrapromobisphenol A (hereinafter referred to as TDA) 750 g, 9% caustic soda aqueous solution 42f, methylene chloride (hereinafter referred to as anal)
302 was added, and 4.2 kg of phosgene was blown in over 30 minutes while stirring and maintaining the temperature at about 20''C.

Next, 209 g of p-tert-butylphenol (hereinafter referred to as PTBP) and 7 d of triethylamine (hereinafter referred to as TEA) dissolved in MC2N were added, and stirring was continued for about 1 hour for polymerization.

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, 35% of isopropanol was added to precipitate the polymer. I let it happen. By filtering the precipitate and then drying it, a white powdery polycarbonate cobolimer (hereinafter referred to as c-p
(denoted as c) was obtained.

The viscosity average molecular weight of c-pc 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 100 liter reaction vessel, 9 kg of TBA, 30 liters of 9% aqueous sodium hydroxide solution, 10ffi of water, MC
21! STE^6d was 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 M0 10N
,↑EA50a+jl was added, and stirring was continued for about 1 hour to polymerize. 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 homooligomer (hereinafter referred to as 80%) with an average degree of polymerization of 5 and a Br content of 50.3%. -PC and notes) were obtained.

Synthesis Example 3 In a 100 liter reaction vessel, 9.8 kg of TBA and 3 parts of water
0f! ．． , MC 37ffi, 9% caustic soda aqueous solution 42, triethylbenzylammonium chloride 4
．． Add 9g of the mixture and adjust the pH of this mixture to 11.0 to 11.0 while stirring.
11.8. While maintaining the temperature at about 20"C, phosgene 3
．． 8 kg was blown in 30 minutes. The pH was adjusted by adding a 35% aqueous sodium hydroxide solution.

Then, the reaction mixture was transferred to a reaction container 1502 and added with a 9% aqueous sodium hydroxide solution 191,BP^2.2-,P
A solution of 1.65 kg of TBP dissolved in MC of 151 was added, and 450 g of TEA was further added, and stirring was continued for about 1 hour for polymerization.

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

Examples 1 to 5 and Comparative Examples 1 to 4 Copolycarbonate resin obtained in Synthesis Example 1 alone or aromatic polycarbonate resin (trade name: Iupilon S-30
00, produced by Mitsubishi Gas Chemical Co., Ltd.) and polycarbonate polymers or oligomers obtained in Synthesis Examples 1 to 3, molecules t 10
00 or 2000 polypropylene glycol, and pentaerythritol tetrastearate (hereinafter referred to as PTS, does not contain unsaturated double bonds) as a mold release agent.
, or beeswax (hereinafter referred to as MR, containing unsaturated double bonds) were mixed in a tumbler at the ratios listed in Table 1, and each was extruded using a single-screw vent extruder to form pellets.

Using this pellet, an injection molding machine (manufactured by Sumitomo Heavy Industries ■;
5 at resin temperature 300℃, mold temperature 80'C, injection pressure 1,200kg/c4
A molded piece of 0x60aa and 3.2mm thick was molded.

This molded piece was irradiated with 2.5 megarads of gamma rays in the air and in a molded product sealed with an oxygen absorber (trade name: Ageless, manufactured by Mitsubishi Gas Chemical) (deoxidizer). , the change in yellowing degree (Y.■.) (ΔY.
I. ) was measured using a color difference meter SM-3-CH manufactured by Suga Test Instruments ■.

The results are shown in Table 1. Note that the descriptions in Table 1 are as follows.

・S-3000: 11 Aromatic Polycarbonate Jugetsu L・C-PC: Br 4.
46χ aromatic #i*f net resin.・HO-PC
: Aromatic polytJ bonate oligomer with Br 50.3χ.・Co-PC. Br
39.7χ aromatic polypower i nate cooligomer.・PTS: Bentaerythritol tetrastearate.・MR: Beeswax. [Operations and Effects of the Invention] As described above, a polycarbonate resin composition obtained by blending a polyalkylene glycol with an aromatic polycarbonate resin containing a structural unit derived from a halogenated bisphenol of the present invention is used, and a mold release agent is further used. When using olefinically unsaturated carbon-carbon double bonds, medical molded products made of materials that do not have olefinically unsaturated carbon-carbon double bonds are susceptible to gamma ray irradiation, not only in air, but especially in substantially oxygen-free conditions. On the other hand, there is less yellowing.

Therefore, it is useful as a case for artificial dialysis machines, artificial lungs, blood transfusion sets, etc. that undergo radiation sterilization (generally T-ray or electron beam sterilization). Patent applicant Mitsubishi Gas Chemical Co., Ltd.

Claims (1)

[Scope of Claims] A polycarbonate resin composition prepared by blending an aromatic polycarbonate polymer or oligomer containing a monohalogenated bisphenol-derived structural unit in its molecular chain and a polyalkylene glycol and can be sterilized by radiation irradiation. Polycarbonate molded product. 2 The halogen content of the aromatic polycarbonate resin is 0.
．． The polycarbonate molded article for radiation sterilization according to claim 1, wherein the content is 1 to 10% by weight. 3 The blending amount of the polyalkylene glycol is 0.1 to 5
% by weight. The polycarbonate molded article for radiation sterilization according to claim 1. The polycarbonate molded article for radiation sterilization according to claim 1, which contains a mold release agent that does not contain a 4-olefinic carbon-carbon unsaturated bond. 5. The polycarbonate molded article for radiation sterilization according to claim 1, wherein the radiation sterilization is carried out in an atmosphere substantially free of oxygen.