JPH0249058A - Molded polycarbonate product capable of sterilization by exposure to radiation - Google Patents

Abstract

PURPOSE:To obtain a molded polycarbonate product, excellent in radiation resistance without hardly any yellowing by radiation and suitable as artificial dialyzers, artificial lungs, etc., by blending an aromatic polycarbonate with an ester having mercapto groups. CONSTITUTION:A molded product obtained by blending (A) 100 pts.wt. aromatic polycarbonate with (B) 0.05-3 pts.wt., preferably 0.1-2 pts.wt. ester [e.g., pentaerythrityl tetrakis(beta-mercaptopropionate], obtained by reacting thioglycolic acid or mercaptopropionic acid with an alcohol selected from compounds expressed by formulas I to IV (m is 8-30; n is 2-10; p is 1 or 0; R is 1-8C alkyl) and having mercapto groups.

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 (BOG) 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. In addition, BUG sterilization has problems such as the toxicity of BOG 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]

As a result of intensive studies aimed at developing a polycarbonate resin that can be molded into medical products suitable for sterilization by radiation irradiation, the present inventors discovered a method of blending a specific compound containing a -3R group into a polycarbonate resin. This led to the present invention.

That is, the present invention uses aromatic polycarbonate resin 100
The weight part contains 0 mercapto group-containing ester of thioglycolic acid or mercaptopropionic acid and alcohol.
．． This is a polycarbonate molded product which can be sterilized by radiation irradiation and is made by molding a polycarbonate resin composition containing 05 to 3 parts by weight, and the alcohol has the following general formula (1
) to (4), general formula (1): C, Hz, +l-OH...
・ (1) General formula (2): lo-C,, H2, -O
H----(2) General formula (3): (R)p[:(C
H20H),,... (3) General formula (4)
: [:(HOc11.), -C-CIl, -)-2
0... (4) (In the formula, m is an integer of 8 to 30, n is an integer of 2 to 10, p is l or 0, and R is an alkyl group having 1 to 4 carbon atoms.) Furthermore, the ester having the mercapto group is pentaerythrityltetrakis (β-mercaptopropionate) or pentaerythrityltetrakis (β-merno J butopropionate) and dipentaerythrityl^xakis (β-mercaptopropionate). It consists of a mixture of

Hereinafter, the configuration of the present invention will be explained.

First, the ester having a mercapto group of the present invention is -3
It is a high-boiling compound containing an H group, and can be easily produced by reacting thioglycolic acid or mercaptopropionic acid with an alcohol, and various compounds are commercially available. Specifically, stearyl thioglycolate, octyl β-mercaptopropionate, octyl α-mercaptopropionate, lauryl β-mercaptopropionate, lauryl α-mercaptopropionate, ethylene glycol dithioglycole), 1,4-butane. Dioldithioglycolate, 1,4-butanediol dimercaptoprobionate, 1,6-hexanethiol dimercaptoprobionate, trimethylolpropane tris(thioglycolate) trimethylolpropane tris(β-mercaptopropionate), Pentaerythritol tetrakis (thioglycolate), pentaerythritol tetrakis (β-mercaptopropionate), pentaerythritol tetrakis (α-mercaptopropionate), dipentaerythritol hexakis (thioglycolate), dipentaerythritol hexakis (β-mercaptopropyl t, r, −)), dipentaerythritol hexakis (α-mercaptopropionate), and the like, which may be used alone or in combination of two or more. Among these compounds, pentaerythritol tetrakis (β-mercaptopropionate) and dipentaerythritol hexakis (β-mercaptopropionate) are particularly effective in reducing yellowing caused by radiation exposure and odor during injection molding. nate) is preferred.

Next, the aromatic polycarbonate resin of the present invention in which the above-mentioned ester 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-his(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)furopane, 1
, 1-bis(4-hydroxyphenyl)-1-phenylethane, and bis(4-hydroxyphenyl)diphenylmethane. Examples of terminal capping agents (molecular weight regulators) include ordinary phenol, monobutylphenol, and tributylphenol. In addition to bromophenol, long-chain alkyl-substituted phenols such as octylphenol, norylphenol, laurylphenol, palmitylphenol, and stearylphenol; Benzoic acid long-chain alkyl esters; long-chain alkyloxyphenols such as octyl ether phenol (= octyloxyphenol), noryl ether phenol, lauryl ether phenol, balmityl ether phenol, octadecyloxyphenol, and dobusyloxyphenol: capric acid chloride, Examples include fatty acid chlorides such as lauric acid chloride, myristic acid chloride, valmitic acid chloride, stearic acid chloride, and cerotic acid chloride.

The amount of the ester having a mercapto group added to the aromatic polycarbonate resin is 0.05 to 3 parts by weight, preferably 0.1 to 3 parts by weight, based on 100 parts by weight of the polycarbonate resin.
If the amount added is less than 0.05 parts, the effect of improving the degree of yellowing due to radiation irradiation will be insufficient;
Even if it is used in an amount exceeding 1 part by weight, no improvement in the yellowing degree can be expected, and on the contrary, mechanical properties, heat resistance, etc. are deteriorated, which is not preferable.

The conditions for manufacturing the radiation sterilizable molded article of the present invention by molding the above aromatic polycarbonate resin composition depend on the viscosity average molecular weight of the aromatic polycarbonate resin used, the amount of ester having a mercapto group, etc. Although it varies, it is usually manufactured by injection molding at 260-340°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 4 and Comparative Example 1 Aromatic polycarbonate resin (trade name: Nipiron S-
The mercaptoesters shown in Table 1 were blended into the mercaptoesters listed in Table 1, and the mixture was appropriately mixed in a tumbler and extruded using a bent-shaft vent extruder to form pellets.

Using this pellet, an injection molding machine (Sumitomo Heavy Industries 033
Manufactured by: Neomat l-350/120) Resin temperature 280
℃, mold temperature 80℃, holding pressure 1000kg/crj
D: A molded piece of 50 x 60 mm and 3 mm thick was molded.

Using this molded piece, 2.5 megarads of gamma rays were irradiated,
The change in yellowing index (Y, 1.) (ΔY, I,) was measured using a color difference meter 5M-3-Cll manufactured by Suga Shikenki ■.

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).

・ PTMP: Pentaerythrityl tetrakis (β-mercapto 1r1 and rice) ・ DPII
M! ' : Dibenquerythrityl hexakis (
Table 1 [Operations and Effects of the Invention] As described above, molded products using the aromatic polycarbonate resin composition blended with the ester having a mercapto group of the present invention are resistant to gamma ray irradiation. On the other hand, there is less yellowing.

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] 1 Molding a polycarbonate resin composition obtained by blending 0.05 to 3 parts by weight of an ester of thioglycolic acid or mercaptopropionic acid with an alcohol having a mercapto group to 100 parts by weight of an aromatic polycarbonate resin. A polycarbonate molded product that can be sterilized by radiation. 2. The polycarbonate molded article that can be sterilized by radiation irradiation according to claim 1, wherein the alcohol is selected from compounds represented by the following general formulas (1) to (4). General formula (1): C_mH_2_m_+_1-OH...
・(1) General formula (2): HO-C_nH_2_n-OH
...(2) General formula (3): (R)_pC(CH_2
OH)_4_-_p...(3) General formula (4): ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(4) (In the formula, m is an integer from 8 to 30, n is 2 ~10 integer, p
is 1 or 0, and R is an alkyl group having 1 to 4 carbon atoms. ) 3 The ester having the mercapto group is pentaerythrityltetrakis (β-mercaptopropionate) or pentaerythrityltetrakis (β-mercaptopropionate) and dipentaerythritylhexakis (β-mercaptopropionate).
Claim 1 is a mixture with mercaptopropionate)
Polycarbonate molded article that can be sterilized by radiation as described.