JPH02115260A - Polycarbonate molding which can be sterilized by irradiation - Google Patents

Abstract

PURPOSE:To obtain the title molding excellent in radiation resistance, lowly yellowed upon irradiation and useful for a dialyzer or the like by molding a resin composition formed by mixing an aromatic polycarbonate resin with a specified thioether. CONSTITUTION:A resin composition formed by mixing 100 pts.wt. aromatic polycarbonate resin, of a viscosity-average MW of desirably, 15000-28000 with 0.01-3 pts.wt. thioether of the formula (wherein n is 1-100; R is H, a 1-20C alkyl or -COCH3; R1 is H, methyl or ethyl; and X is a direct bond or O), e.g., 2,2'- thiodiethanol, is molded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a polycarbonate molded article with excellent radiation resistance. The polycarbonate molded product of the present invention has little yellowing due to radiation, so it can be used in artificial dialysis machines that undergo radiation sterilization.
It is useful as a case for artificial lungs, blood transfusion sets, etc.

[Conventional methods and their problems]

Conventionally, polycarbonate resins have been used in medical products such as artificial dialysis machines, artificial lungs, and blood transfusion sets.

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

Therefore, recently, a sterilization method that involves irradiation with radiation (gamma rays for boat fishing), which can be carried out relatively inexpensively, at low temperatures, and in a dry manner, has been attracting attention.

However, when polycarbonate resin is normally irradiated with radiation, the resin decomposes, causing yellowing, which tends to impair product value.

As mentioned above, there has been a demand for polycarbonate resins that can be molded into medical products suitable for sterilization by radiation irradiation.

[Means to solve the problem]

The inventors of the present invention have conducted intensive studies to develop a polycarbonate resin that can be molded into medical products suitable for sterilization by radiation irradiation, and have discovered a method of blending a specific sulfur-containing compound into a polycarbonate resin. This led to the invention.

That is, 0.01 parts by weight of the thioether represented by the following general formula (1) was added to 100 parts by weight of the aromatic polycarbonate resin.
This is a polycarbonate molded article that can be sterilized by radiation irradiation and is made by molding a polycarbonate resin composition containing ~3 parts by weight.

(In the formula, n is a positive number with an average of 1 to 100, R is hydrogen, an alkyl group having 1 to 20 carbon atoms, or -CDCI (3, R1 is hydrogen, a methyl group, or an ethyl group, and X is a simple bond or an oxygen atom. ) The configuration of the present invention will be described below.

First, the sulfur-containing compound of the present invention is a thioether represented by the above general formula (1). The thioether of the present invention can be produced by reactions between alkylene oxide and hydrogen sulfide; reactions between mercapto alcohols or alkyl mercaptans and dichloroalkanes; reactions between alkyl mercaptans and alkyl chlorides; reactions between mercapto alcohols or alkyl mercaptans and dichloroalkanes and dimercaptoalkanes. It is easily produced by reaction, etc., and various products are commercially available. Specifically 2.2
'-Thiogetanol, 3.3'-thiodibrobanol, 2.2'-thiogetanol dimethyl ether, 2.
2'-Thiogetanol monomethyl ether 2.2°-
Thiogetanol diacetate, 2,2'-thiogetanol monoacetate), 1,2-bis[(2-hydroxyethyl)thio]ethane, 1,2-bis[(2-ethyl)thio]ethane, Examples include 1,2-bis[(2-butyl)thio]ethane, bis(5-hydroxyethyl-3-thioethyl)sulfide, dibutylsulfide, dilaurylsulfide, distearylsulfide, alkylene polysulfide, etc., and may be used alone or as appropriate. 2
Use a mixture of more than one species.

Next, the aromatic polycarbonate resin of the present invention in which the above-mentioned thioether is blended may be a conventional aromatic homo- or copolycarbonate resin, and is not particularly limited. It is formed by reacting a terminator, and in the present invention, the viscosity average molecular weight is preferably in the range of 15.000 to 28.000.

Here, as an aromatic dihydric phenol compound, bis(
4-hydroxyphenyl) methane, 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-dibromophenyl)propane, 2.
2-bis(4-hydroxy-3,5-dichlorophenyl)propane, 2.2-bis(4-hydroxy-3-bromophenyl)propane, 2,2-bis(4-hydroxy-3-chlorophenyl)furopane, 2 .2-bis(4-
Hydroxy-3,5-dimethylphenyl)propane, 1
．． Examples include 1-bis(4-hydroxyphenyl)-1-phenylethane and bis(4-hydroxyphenyl)diphenylmethane, and terminal cappers (molecular weight regulators) include ordinary phenol, Pt-butylphenol, and tribromophenol. In addition, long-chain alkyl-substituted phenols such as octylphenol, norylphenol, laurylphenol, valmitylphenol, and stearylphenol: Hydroxybenzoic acids such as octyl hydroxybenzoate, lauryl hydroxybenzoate, noryl hydroxybenzoate, and stearyl hydroxybenzoate. Long-chain alkyl esters; long-chain alkyloxyphenols such as octyl ether phenol (= octyloxyphenol), nolyl ether phenol, lauryl ether phenol, palmityl ether phenol, octadecyloxyphenol, dobusyloxyphenol: capric acid chloride, lauric acid Examples include aliphatic acid chlorides such as chloride, myristic acid chloride, palmitic acid chloride, stearic acid chloride, and cerotic acid chloride.

The amount of thioether added to the aromatic polycarbonate resin is 0.00 parts by weight per 100 parts by weight of the polycarbonate resin.
01 to 3 parts by weight, preferably 0.05 to 2 parts by weight; if the amount added is less than 0.01 parts by weight, the effect of improving the degree of yellowing due to radiation irradiation is insufficient, and if the amount added is more than 3 parts by weight. Even if it is used, no improvement in the yellowing degree improvement effect can be expected, and on the contrary, mechanical properties, heat resistance, etc. deteriorate, which is not preferable.

The conditions for producing the radiation sterilizable molded article of the present invention by molding the aromatic polycarbonate resin composition described above vary depending on the viscosity average molecular weight of the aromatic polycarbonate resin used, the amount of thioether added, etc. However, 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 Examples and Comparative Examples.

Examples 1 to 5 and Comparative Example 1 Aromatic polycarbonate resin (trade name: Nipiron S-
2000, manufactured by Mitsubishi Gas Chemical Co., Ltd.) were blended with the thioethers listed in Table 1, mixed appropriately in a tumbler, and extruded using a bent-shaft vent extruder to form pellets.

Using this pellet, an injection molding machine (manufactured by Sumitomo Heavy Industries ■;
Neopine) 350/120) resin temperature 280℃,
A molded piece of 50×60 mm and 1.6 mm thick was molded at a mold temperature of 80° C. and a holding pressure of 1000 kg/cITr.

Using this molded piece, 2.5 megarads of gamma rays were irradiated,
The change (ΔY, I,) in the yellowing index (Y, I,) was measured using a color difference meter 5M-3-C8 manufactured by Suga Test Instruments.

The results are shown in Table 1.

The abbreviations in the table are as follows, and the amounts added are parts by weight based on 100 parts by weight of the aromatic polycarbonate resin (S-2000).

- TUB: 2.2'-thiogentanol.

- TDEM: 2,2'-thiodietanol dimethyl ether.

・Blt[ESE: 1,2-bis [(2-
hydroxyethyl)thio]ethane.

-BESE: 1.2-bis[(2-ethyl)thio]ethane.

・PTDE: t([]C2H,-(-3-
C2H, -), -OH; n = 10゜ [Operations and effects of the invention] As described above, molded products using the aromatic polycarbonate resin composition blended with the thioether of the present invention do not yellow when irradiated with gamma rays. Less is.

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)

[Scope of Claims] Radiation sterilization made by molding a polycarbonate resin composition prepared by blending 0.01 to 3 parts by weight of a thioether represented by the following general formula (1) with 100 parts by weight of an aromatic polycarbonate resin. Possible polycarbonate moldings. General formula (1): ▲There are mathematical formulas, chemical formulas, tables, etc.▼... (1) (In the formula, n is a positive number with an average of 1 to 100, R is hydrogen, an alkyl group having 1 to 20 carbon atoms, or - COCH_3, R_1 are hydrogen, methyl group or ethyl group, X is a simple bond or an oxygen atom.)