JP5347244B2 - Method for producing halogen-containing polycarbonate resin - Google Patents

Abstract

A halogen-containing polycarbonate resin composition is provided to realize excellent color tone stability and transparency under ionizing radiation such as gamma rays, and to prevent yellowing in medical instruments subjected to radiation sterilization. A halogen-containing polycarbonate resin composition comprises a halogen-containing polycarbonate resin, a carboxylate and a phosphorus compound. The halogen-containing polycarbonate resin composition has a chromaticness index b of 3.50 or less in the Hunter's color difference formula in the Lab color coordinate system, after 2 days from the irradiation of gamma rays with 25 kGy in the absence of oxygen, and shows a variance in haze of 10% or less.

Description

  The present invention relates to a halogen-containing polycarbonate resin composition and the like, and more particularly to a polycarbonate resin composition and the like excellent in transparency and color tone stability under γ-ray irradiation.

  In the production of a polycarbonate resin using 2,2-bis (4-hydroxyphenyl) propane (hereinafter sometimes referred to as bisphenol A or BPA) by an interfacial method, an organic solvent solution of the resin obtained by a polymerization reaction is used. Purify the resin by washing with an aqueous cleaning solution such as water or acid aqueous solution, concentrate the organic solvent solution of the purified resin, pulverize the resin, or granulate in hot water To be done.

On the other hand, when producing a halogen-containing polycarbonate resin for the purpose of making the resin flame-retardant, try to produce a polycarbonate resin containing a relatively large amount of halogen, for example, about 4% by weight, which is desired for flame-retarding. Then, it is known that the organic solvent solution of the resin obtained by the polymerization reaction is difficult to clean and granulate as compared with the case where only bisphenol A is used as a raw material.
In addition, the polycarbonate resin having a high halogen content produced in this way has a problem that the melt fluidity is inferior as compared with a polycarbonate resin using only bisphenol A as a raw material.

  For example, bromo obtained by reacting carbonate oligomer with 2,2-bis (3,5-dibromo-4-hydroxyphenyl) ethane (hereinafter sometimes referred to as tetrabromobisphenol A or TBA) and bisphenol A. A 10% by weight methylene chloride solution of a polycarbonate resin with a content of 4% by weight or more (see Patent Document 1) may cause an emulsion to form when the industrial scale is washed, so that the organic solvent solution of the resin and the aqueous washing solution are not separated. Even if separated, a large amount of a dirt layer (intermediate layer) is generated, and the cleaning efficiency is low. For this reason, since impurities in the resin are not sufficiently removed, the resulting resin has a poor color tone and low thermal stability. It is difficult to make it difficult, and industrial production is difficult.

Also, a method for producing a resin having good melt fluidity by copolymerizing two specific carbonate oligomers to facilitate washing of an organic solvent solution of a halogen-containing polycarbonate resin and pulverization with concentration. Has been proposed (see Patent Document 2).
However, although these production methods are excellent in the detergency of the organic solvent solution of the resin, there is a problem in the molecular weight stability of the obtained resin, and granulation accompanying a decrease in the molecular weight may be difficult.

Therefore, as a method for solving such a problem, the present applicant has disclosed a method of mixing and polymerizing a BPA oligomer and a (BPA and TBBPA) copolymer oligomer (see Patent Document 3).
By using such a technique, efficient production of a high-quality halogen-containing flame-retardant polycarbonate resin having excellent molecular weight stability, detergency, powdering properties, etc. has been achieved.

  Polycarbonate resins, on the other hand, are used in various medical parts because of their excellent mechanical and thermal properties, transparency and hygiene. Here, as medical parts, a container-like packaging device for containing and packaging a syringe, a surgical tool, a intravenous syringe, a surgical instrument, and the like, an artificial lung, an artificial kidney, an anesthesia absorber, a venous connector and accessories, Examples thereof include medical devices such as blood centrifuges, surgical tools, surgical tools, and the like.

  These medical parts are usually completely sterilized. Specific examples include contact treatment with ethylene oxide, heat treatment in an autoclave, treatment with ionizing radiation such as gamma (γ) rays and electron beams, and the like. Of these, the use of ethylene oxide is not preferable because of the toxicity and instability of ethylene oxide itself and environmental problems related to disposal. In addition, when using an autoclave, the resin may be deteriorated during high-temperature treatment, the energy cost is high, and moisture remains in the treated parts, so it is necessary to dry them before use. It has some drawbacks. Therefore, sterilization with ionizing radiation, which can be performed at a low temperature and is relatively inexpensive, is widely used in place of these methods.

  However, when the aromatic polycarbonate resin is irradiated with ionizing radiation, the originally optically transparent resin turns yellow. Therefore, a method of offsetting yellow by mixing a blue colorant in the resin, a method of adding a boron compound (see Patent Document 4), a method of adding a polyether polyol or its alkyl ether (see Patent Document 5) ) Etc. have been proposed.

However, even if these methods are used, the effect of preventing the yellowing of the aromatic polycarbonate resin may be insufficient. Further, when a predetermined amount of yellowing inhibitor is added to the aromatic polycarbonate resin, the strength of the resin may be significantly impaired.
Therefore, the present applicant adds 0.1 wt% to 5 wt% of polypropylene glycol having a molecular weight of about 4,500 to a halogenated aromatic polycarbonate resin containing 0.1 wt% to 10 wt% of halogen. Thus, a medical component using a material with little color tone and deterioration in physical properties even after irradiation treatment with γ rays or the like was reported (see Patent Document 6).

JP 07-196907 A JP-A-57-155233 JP 2005-179549 A JP 61-215651 A Japanese Patent Laid-Open No. 62-135556 Japanese Patent Publication No. 06-24591

However, if further investigation is made, if the medical part using the halogenated aromatic polycarbonate resin composition described in Patent Document 6 is subjected to irradiation treatment such as γ-rays, the yellowing of the resin is reduced. However, in order to sterilize medical parts, it has been found that the resin may turn yellow due to irradiation with ionizing radiation such as γ rays under more severe conditions, resulting in a decrease in color tone. For this reason, there is a need for a method of obtaining a material with less color tone and physical property deterioration.
This invention is made | formed in order to solve the subject at the time of developing the halogen containing polycarbonate resin used for the use irradiated with ionizing radiations, such as such a gamma ray.
That is, an object of the present invention is to provide a halogen-containing polycarbonate resin composition excellent in transparency and color tone stability under irradiation of ionizing radiation such as γ rays.
Another object of the present invention is to provide a method for producing a halogen-containing polycarbonate resin having excellent ionizing radiation resistance.
Furthermore, another object of the present invention is to provide a medical instrument using a halogen-containing polycarbonate resin composition having excellent ionizing radiation resistance.

As a result of intensive research to solve the above problems, the present inventors have conducted interfacial polycondensation using a mixture of a halogen-free carbonate oligomer and a halogen-containing aromatic dihydroxy compound. On the other hand, it was found that a halogen-containing polycarbonate resin having good color tone stability was obtained, and the present invention was completed based on such knowledge.
Thus, according to the present invention, there is provided a halogen-containing polycarbonate resin composition comprising a halogen-containing polycarbonate resin, a carboxylic acid ester and a phosphorus compound, and a Lab color system hunter after 2 days of γ-irradiation at 25 kGy under oxygen interruption. The halogen-containing polycarbonate resin composition is characterized in that the chromaticness index b in the color difference formula is 3.50 or less and the change rate of haze is 10% or less.

Here, in the halogen-containing polycarbonate resin composition to which the present invention is applied, 0.01 part by weight to 1 part by weight of a carboxylic acid ester and 0.01 part by weight of a phosphorus compound with respect to 100 parts by weight of the halogen-containing polycarbonate resin 1 part by weight is preferably added.
Moreover, it is preferable that the halogen content of halogen-containing polycarbonate resin is 0.1 to 2 weight%.
Furthermore, the carboxylic acid ester is preferably an aliphatic carboxylic acid ester, and the phosphorus compound is preferably a phosphite.

  The molded body using the halogen-containing polycarbonate resin composition to which the present invention is applied can be used as a medical instrument excellent in ionizing radiation resistance particularly against γ-ray irradiation.

Next, according to the present invention, there is provided a method for producing a halogen-containing polycarbonate resin, which comprises reacting an alkali metal or alkaline earth metal compound of an aromatic dihydroxy compound not containing halogen with carbonyl chloride to synthesize a carbonate oligomer. An oligomer synthesis step, and a polymerization step of polymerizing a carbonate oligomer synthesized by the oligomer synthesis step and an alkali metal or alkaline earth metal compound of a halogen-containing aromatic dihydroxy compound and / or a halogen-containing aromatic dihydroxy compound. The ratio of the terminal chloroformate group concentration (CF) and the halogen-containing aromatic dihydroxy compound concentration (BPX) in the carbonate oligomer in the polymerization step (CF / BPX) is 10 to 60 (equivalent ratio), and the carbonate Oligomer A halogen-containing polycarbonate resin having a ratio (OH / BPX) of a terminal hydroxyl group concentration (OH) to a halogen-containing aromatic dihydroxy compound concentration (BPX) of 4.5 to 27 (equivalent ratio) A manufacturing method is provided.

Here, the ratio (CF / OH) of the terminal chloroformate group concentration (CF) in the carbonate oligomer to be used and the terminal hydroxyl group concentration (OH) in the carbonate oligomer is 1.5 to 3.0 (equivalent ratio). Preferably there is.
Moreover, it is preferable that a carbonate oligomer has a repeating unit shown to following Structural formula (1).

  Furthermore, the halogen-containing aromatic dihydroxy compound is preferably tetrabromobisphenol A represented by compound (2).

  The halogen content of the halogen-containing polycarbonate resin is 0.1% by weight to 2% by weight.

  According to the present invention, a halogen-containing polycarbonate resin composition excellent in transparency and color tone stability under γ-ray irradiation can be obtained.

The best mode for carrying out the present invention (hereinafter, an embodiment of the present invention) will be described in detail below. The present invention is not limited to the following embodiments, and various modifications can be made within the scope of the invention.
In the present embodiment, the “halogen content” of the polycarbonate resin means the concentration of halogen atoms bonded to the main chain portion (phenyl group) of the oligomer or polymer excluding the terminal chloroformate group.
“Halogen-free” (hereinafter sometimes referred to as “halogen-free”) means that there is no halogen atom bonded to the main chain (phenyl group) of the polycarbonate resin. Does not exclude oligomers having terminal chloroformate groups. The terminal chloroformate group is involved in the polymerization reaction and is almost completely consumed by the completion of the polymerization, and the color tone stability of the polymer involves a halogen atom bonded to the main chain (phenyl group).

The following two types of methods for producing a halogen-containing polycarbonate resin can be mentioned.
(1) A method of synthesizing a halogen-containing carbonate oligomer from a halogen-free aromatic dihydroxy compound or a halogen-containing aromatic dihydroxy compound and carbonyl chloride, and polycondensing the halogen-containing carbonate oligomer.
(2) A method of reacting a halogen-free aromatic dihydroxy compound and a carbonyl chloride to synthesize a halogen-free carbonate oligomer and reacting the halogen-free carbonate oligomer with a halogen-containing aromatic dihydroxy compound.
In the present embodiment, the method (2) will be described. In addition, compared with the method (1), the method (2) has the advantage that the polymerization time can be shortened.

  The method for producing a halogen-containing polycarbonate resin to which this embodiment is applied is an oligomer that synthesizes a halogen-free carbonate oligomer by reacting an alkali metal or alkaline earth metal compound of a halogen-free aromatic dihydroxy compound with carbonyl chloride. A synthesis step and a polymerization step of polymerizing the halogen-free carbonate oligomer and the halogen-containing aromatic dihydroxy compound and / or the alkali metal or alkaline earth metal compound of the halogen-containing aromatic dihydroxy compound. Hereinafter, each step will be described.

(Oligomer synthesis process)
In the oligomer synthesis step in the present embodiment, a halogen-free carbonate oligomer is produced by reacting an alkali metal or alkaline earth metal compound of a halogen-free aromatic dihydroxy compound with carbonyl chloride by a well-known interfacial polymerization method or solution polymerization method. Is synthesized.
Here, the halogen-free carbonate oligomer has a viscosity average molecular weight (Mv) of several hundred to several thousand, and a ratio (CF / OH) of terminal chloroformate group concentration (CF) to terminal hydroxyl group concentration (OH) is 1. 0.5 to 3.0 (equal ratio), preferably 2.0 to 3.0.

  Examples of aromatic dihydroxy compounds are shown below. Examples of the aromatic dihydroxy compound include 1,1-bis (4-hydroxyphenyl) ethane, bis (4-methyl-2-hydroxyphenyl) methane, and 1,1-bis (4-hydroxyphenyl) -4-methyl. Pentane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (3-methyl-4-hydroxyphenyl) propane, 2 , 2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 1,1-bis (4-hydroxyphenyl) -2-ethyl Hexane, 2,2-bis (3-phenyl-4-hydroxyphenyl) propane, bis (3-methyl-4-hydroxyphenyl) methane,

4,4′-biphenol, 2,2-bis (4-hydroxyphenyl) butane, 1,1-bis (4-hydroxyphenyl) -2-methylpropane, bis (4-hydroxyphenyl) phenylmethane, 2,2 -Bis (4-hydroxyphenyl) octane, 1,1-bis (3-methyl-4-hydroxyphenyl) cyclohexane, 2,2-bis (3-allyl-4-hydroxyphenyl) propane, 2,2-bis ( 3-isopropyl-4-hydroxyphenyl) propane, 2,2-bis (3-tert-butyl-4-hydroxyphenyl) propane, 2,2-bis (3-sec-butyl-4-hydroxyphenyl) propane, bisphenol Fluorene, 1,1-bis (2-methyl-4-hydroxy-5-tert-butylphenyl) -2-methyl Bread,

4,4 ′-[1,4-phenylene-bis (2-propylidene) -bis (3-methyl-4-hydroxyphenyl)], 1,1-bis (3-phenyl-4-hydroxyphenyl) cyclohexane, 4 , 4′-dihydroxyphenyl ether, bis (2-hydroxyphenyl) methane, 2,4′-methylenebisphenol, bis (3-methyl-4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) propane 1,1-bis (2-hydroxy-5-methylphenyl) ethane, 1,1-bis (4-hydroxyphenyl) -3-methyl-butane,

Bis (2-hydroxy-3,5-dimethylphenyl) methane, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (3-methyl-4-hydroxyphenyl) cyclopentane, 3,3 -Bis (4-hydroxyphenyl) pentane, 3,3-bis (3-methyl-4-hydroxyphenyl) pentane, 3,3-bis (3,5-dimethyl-4-hydroxyphenyl) pentane, 2,2- Bis (2-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxyphenyl) nonane, 1,1-bis (3-methyl-4-hydroxyphenyl) -1-phenylethane, 1 , 1-bis (3,5-dimethyl-4-hydroxyphenyl) cyclohexane,

2,2-bis (4-hydroxyphenyl) decane, 1,1-bis (4-hydroxyphenyl) decane, bis (2-hydroxy-3-tert-butyl-5-methylphenyl) methane, bis (4-hydroxy Phenyl) diphenylmethane, terpene diphenol, 1,1-bis (3-tert-butyl-4-hydroxyphenyl) cyclohexane, 1,1-bis (2-methyl-4-hydroxy-5-tert-butylphenyl) -2 -Methylpropane, 2,2-bis (3-cyclohexyl-4-hydroxyphenyl) propane, bis (3,5-di-tert-butyl-4-hydroxyphenyl) methane, bis (3,5-di-sec- Butyl-4-hydroxyphenyl) methane,

1,1-bis (3-cyclohexyl-4-hydroxyphenyl) cyclohexane, 1,1-bis (2-hydroxy-3,5-di-tert-butylphenyl) ethane, 1,1-bis (3-nonyl- 4-hydroxyphenyl) methane, 2,2-bis (3,5-di-tert-butyl-4-hydroxyphenyl) propane, bis (2-hydroxy-3,5-di-tert-butyl-6-methylphenyl) ) Methane, 1,1-bis (3-phenyl-4-hydroxyphenyl) -1-phenylethane, 4,4-bis (4-hydroxyphenyl) pentanoic acid,

α, α′-bis (4-hydroxyphenyl) acetic acid butyl ester, 2,2-bis (3-nitro-4-hydroxyphenyl) propane, 3,3′-dimethyl-4,4′-biphenol, 3,3 ', 5,5'-tetramethyl-4,4'-biphenol, 3,3', 5,5'-tetra-tert-butyl-4,4'-biphenol, bis (4-hydroxyphenyl) ketone, bis (4-hydroxyphenyl) dimethylsilane, bis (4-hydroxyphenyl) sulfone, bis (3-methyl-4-hydroxyphenyl) sulfone, bis (3,5-dimethyl-4-hydroxyphenyl) sulfone,

Bis (4-hydroxyphenyl) thioether, bis (3-methyl-4-hydroxyphenyl) ether, bis (3-methyl-4-hydroxyphenyl) thioether, bis (3,5-dimethyl-4-hydroxyphenyl) ether, Bis (3,5-dimethyl-4-hydroxyphenyl) thioether, 1,1-bis (2,3,5-trimethyl-4-hydroxyphenyl) -1-phenylmethane, 2,2-bis (3-methyl- 4-hydroxyphenyl) dodecane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) dodecane,

1,1-bis (3-tert-butyl-4-hydroxyphenyl) -1-phenylethane, 1,1-bis (3,5-di-tert-butyl-4-hydroxyphenyl) -1-phenylethane, 1,1-bis (2-methyl-4-hydroxy-5-cyclohexylphenyl) -2-methylpropane, 1,1-bis (2-hydroxy-3,5-di-tert-butylphenyl) ethane, 2, 2-bis (4-hydroxyphenyl) propanoic acid methyl ester, 2,2-bis (4-hydroxyphenyl) propanoic acid ethyl ester, 1,3-bisphenol, 1,3-biscresol, 2,2 ′, 3 3 ′, 5,5′-hexamethyl-4,4′-biphenol, bis (2-hydroxyphenyl) methane, 2,4′-methylenebisphenol, 1,2-biphenol (4-hydroxyphenyl) ethane, 2- (4-hydroxyphenyl) -2- (2-hydroxyphenyl) propane,

Bis (2-hydroxy-3-allylphenyl) methane, 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -2-methylpropane, 1,1-bis (2-hydroxy-5-tert- Butylphenyl) ethane, bis (2-hydroxy-5-phenylphenyl) methane, 1,1-bis (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, bis (2-methyl-4-hydroxy) -5-cyclohexylphenyl) methane,

2,2-bis (4-hydroxyphenyl) pentadecane, 2,2-bis (3-methyl-4-hydroxyphenyl) pentadecane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) pentadecane, , 2-bis (3,5-di-tert-butyl-4-hydroxyphenyl) ethane, bis (2-hydroxy-3,5-di-tert-butylphenyl) methane, 2,2-bis (3-styryl) -4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) -1- (p-nitrophenyl) ethane,

3,3 ′, 5,5′-tetra-tert-butyl-2,2′-biphenol, 2,2′-diallyl-4,4′-biphenol, 1,1-bis (4-hydroxyphenyl) -3 , 3-Dimethyl-5-methylcyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5,5-tetramethylcyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3 4-trimethylcyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3-dimethyl-5-ethylcyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclopentane, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis (3,5-diphenyl-4-hydroxy Enyl) -3,3,5-trimethylcyclohexane, 1,1-bis (3-methyl-4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis (3-phenyl-4-hydroxy) Phenyl) -3,3,5-trimethylcyclohexane,

Resorcinol, hydroquinone, 1,2-hydroxybenzene, 1,4-bis (4-hydroxyphenyl) -p-menthane, 1,4-bis (3-methyl-4-hydroxyphenyl) -p-menthane, 1,4 Examples include terpene diphenols such as -bis (3,5-dimethyl-4-hydroxyphenyl) -p-menthane. Of these compounds, bisphenol A is preferred.
In addition, in this Embodiment, it is not limited to these aromatic dihydroxy compounds mentioned above, Another aromatic dihydroxy compound can also be used. Moreover, these aromatic dihydroxy compounds can be used alone or in combination.

  Moreover, you may substitute a part of aromatic dihydroxy compound mentioned above with another aliphatic dihydroxy compound in the range which does not impair the characteristic substantially. Examples of such dihydric alcohols include ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, heptanediol, octanediol, dodecanediol, neopentylglycol, cyclohexanediol, and 1,4-dihydroxymethylcyclohexane. be able to.

(Alkali metal or alkaline earth metal compound)
In the present embodiment, the aromatic dihydroxy compound forms an aqueous phase together with water and an alkali metal or alkaline earth metal compound. As the alkali metal or alkaline earth metal compound, a hydroxide is usually preferable, and examples thereof include sodium hydroxide, lithium hydroxide, potassium hydroxide, magnesium hydroxide, and calcium hydroxide. Among these, water is particularly preferable. Sodium oxide is preferred.
The ratio of the alkali metal or alkaline earth metal compound to the aromatic dihydroxy compound is usually 1.0 to 1.5 (equivalent ratio), preferably 1.02 to 1.04 (equivalent ratio). When the ratio of the alkali metal or alkaline earth metal compound is excessively large or excessively small, the resulting oligomer end group is affected, and as a result, the condensation reaction tends to become abnormal. A small amount of a reducing agent such as hydrosulfite may be added to the aqueous phase.

In the oligomer synthesis step in the present embodiment, an organic solvent is usually used. The organic solvent includes any inert organic solvent that dissolves a reaction product such as carbonyl chloride, a carbonate oligomer, and a polycarbonate at a reaction temperature and a reaction pressure and is incompatible with water (does not form a solution with water).
As an inert organic solvent, aliphatic hydrocarbons such as hexane and n-heptane; chlorinated aliphatic hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, dichloroethane, trichloroethane, tetrachloroethane, dichloropropane and 1,2-dichloroethylene Aromatic hydrocarbons such as benzene, toluene and xylene; chlorinated aromatic hydrocarbons such as chlorobenzene, o-dichlorobenzene and chlorotoluene; and other substituted aromatic hydrocarbons such as nitrobenzene and acetophenone.
Among these, chlorinated hydrocarbons such as methylene chloride or chlorobenzene are preferably used. These inert organic solvents can be used alone or as a mixture with other solvents.

(Carbonyl chloride)
The carbonyl chloride used in the present embodiment (hereinafter sometimes referred to as CDC) is usually used in liquid or gaseous form. From the viewpoint of temperature control, the CDC is preferably in a liquid state, and a reaction pressure that can maintain the liquid state at the reaction temperature is selected. The preferred amount of CDC is appropriately selected according to the reaction conditions, particularly the reaction temperature and the concentration of the metal salt of the aromatic dihydroxy compound in the aqueous phase, and is not particularly limited, but is usually CDC1 per 1 mol of the aromatic dihydroxy compound. 0.05 mol to 1.30 mol, preferably 1.20 mol to 1.25 mol. When the amount of CDC used is too small, the ratio (CF / OH) of the terminal chloroformate group concentration (CF) in the carbonate oligomer and the terminal hydroxyl group concentration (OH) in the carbonate oligomer is less than 1.5. Tend to be. Further, when the amount of CDC used is excessively large, the loss of CDC increases and (CF / OH) tends to exceed 3.0.

  In the present embodiment, any branching agent can also be used as a raw material for the polycarbonate in the oligomer synthesis step. The branching agent used can be selected from a variety of compounds having three or more functional groups. Suitable branching agents include compounds having 3 or more phenolic hydroxyl groups such as 2,4-bis (4-hydroxyphenylisopropyl) phenol, 2,6-bis (2-hydroxy- 5-methylbenzyl) -4-methylphenol, 2- (4-hydroxyphenyl) -2- (2,4-dihydroxyphenyl) propane and 1,4-bis (4,4′-dihydroxytriphenylmethyl) benzene Can be mentioned. Further, 2,4-dihydroxybenzoic acid, trimesic acid, and cyanuric chloride, which are compounds having three functional groups, can also be used. Among these, those having 3 or more phenolic hydroxyl groups are preferred. The amount of the branching agent used varies depending on the target branching degree, but is usually used in an amount of 0.05 mol% to 2 mol% with respect to the aromatic diols.

  Furthermore, in the oligomer synthesis step in the present embodiment, monophenols are usually used as a chain terminator. Monophenols used as chain terminators include: phenol; alkylphenols having 1 to 20 carbon atoms such as pt-butylphenol and p-cresol; halogens such as p-chlorophenol and 2,4,6-tribromophenol Phenol is included. The amount of monophenols used varies depending on the molecular weight of the desired condensate, but is usually 0.5 mol% to 10 mol% (0.005 times to 0.1 times) with respect to the aromatic dihydroxy compound. Used in quantity.

  The molecular weight of polycarbonate is determined by the amount of addition of a chain terminator such as monophenol. From the viewpoint of molecular weight controllability, the timing of addition is from immediately after consumption of the carbonate-forming compound is completed and before molecular weight extension begins. Is preferred. When monophenols are added in the presence of a carbonate-forming compound, a large amount of condensates (monophenyl carbonates) of monophenols are formed, and it is not preferable because a polycarbonate resin having a target molecular weight cannot be obtained. On the other hand, if the addition of monophenols is extremely delayed, the molecular weight control becomes difficult and the resin has a unique shoulder on the low molecular weight distribution side, causing many problems such as dripping during molding. , Not very preferable.

In the present embodiment, when the two-phase interfacial condensation method is employed, it is particularly preferable that the organic phase and the aqueous phase are brought into contact with each other before the contact with carbonyl chloride to form an emulsion. In order to form an emulsion, in addition to a stirrer having a normal stirring blade, mixing with a dynamic mixer such as a homogenizer, a homomixer, a colloid mill, a flow jet mixer, an ultrasonic emulsifier, or a static mixer It is preferable to use a machine. The emulsion usually has a droplet diameter of 0.01 μm to 10 μm and has emulsion stability.
The state of emulsification can usually be expressed by the Weber number or P / q (additional power value per unit volume). The Weber number is preferably 10,000 or more, more preferably 20,000 or more, and most preferably 35,000 or more. Also, the upper limit is about 1,000,000 or less. P / q is preferably 200 kg · m / liter or more, more preferably 500 kg · m / liter or more, and most preferably 1,000 kg · m / liter or more.

  The contact between the emulsion and carbonyl chloride (CDC) is preferably carried out under mixing conditions weaker than the emulsification conditions described above in order to suppress dissolution of CDC in the organic phase. The Weber number is less than 10,000, preferably less than 5,000, and more preferably less than 2,000. Further, P / q is less than 200 kg · m / liter, preferably less than 100 kg · m / liter, and more preferably less than 50 kg · m / liter. CDC contact can be achieved by introducing CDC into a tubular reactor or tank reactor.

  The oligomerization reaction can be performed in the presence of a condensation catalyst. The addition is preferably performed after the CDC is consumed, and the condensation catalyst can be arbitrarily selected from many condensation catalysts used in the two-phase interfacial condensation method. Among them, trialkylamine, N-ethylpyrrolidone, N-ethylpiperidine, N-ethylmorpholine, N-isopropylpiperidine and N-isopropylmorpholine are suitable, and triethylamine and N-ethylpiperidine are particularly suitable.

  The reaction temperature for obtaining the oligomer is 80 ° C. or lower, preferably 60 ° C. or lower, more preferably 10 ° C. to 50 ° C. The reaction time depends on the reaction temperature, but is usually 0.5 minutes to 10 hours, preferably 1 minute to 2 hours. If the reaction temperature is too high, side reactions cannot be controlled and the CDC basic unit deteriorates. On the other hand, if it is too low, this is a preferable situation in terms of reaction control, but the refrigeration load increases, and the cost increases accordingly, which is not preferable.

  The oligomer concentration in the organic phase may be in a range in which the resulting oligomer is soluble, and is specifically about 10 to 40% by weight. The proportion of the organic phase is preferably a volume ratio of 0.2 to 1.0 with respect to the aqueous alkali or alkaline earth metal salt solution of the aromatic dihydroxy compound, that is, the aqueous phase.

(Polymerization process)
In the polymerization step in the method for producing a halogen-containing polycarbonate resin to which the present embodiment is applied, the halogen-free carbonate oligomer synthesized in the oligomer synthesis step and the halogen-containing aromatic dihydroxy compound are subjected to interfacial polycondensation according to a conventional method. Done. At this time, during the interfacial polycondensation, an alkali metal or alkaline earth metal salt aqueous solution of a halogen-containing aromatic dihydroxy compound and / or a halogen-containing aromatic dihydroxy compound is added.

In a preferred embodiment of the polymerization step, the organic phase in which the halogen-free carbonate oligomer is dissolved is separated from the aqueous phase, and the inert organic solvent described above is added to this to adjust the concentration of the halogen-free carbonate oligomer as necessary. To do. In this case, the amount of the solvent is adjusted so that the concentration of the halogen-containing polycarbonate resin in the organic phase obtained by polycondensation is 5% by weight to 30% by weight.
Next, a solution containing an aqueous phase containing water and an alkali metal hydroxide and a halogen-containing aromatic dihydroxy compound is added, and in order to further adjust the polycondensation conditions, a condensation catalyst is preferably added, and interface polycondensation is performed. The polycondensation is completed according to the law. The ratio of the organic phase to the aqueous phase during the polycondensation is preferably about organic phase: aqueous phase = 1: 0.2 to 1 in volume ratio.

(Halogen-containing aromatic dihydroxy compound)
Examples of the halogen-containing aromatic dihydroxy compound used in the polymerization step include tetrabromobisphenol A (TBA), 2,2-bis (3,5-dichloro-4-hydroxyphenyl) propane, and 2,2-bis (3 -Bromo-4-hydroxyphenyl) propane, 2,2-bis (3-chloro-4-hydroxyphenyl) propane, 2,2-bis (2,3,5,6-tetrabromo-4-hydroxyphenyl) propane, Examples include 2,2-bis (2,3,5,6-tetrachloro-4-hydroxyphenyl) propane. Among these, tetrabromobisphenol A (TBA) is preferable.

  The amount of the halogen-containing aromatic dihydroxy compound used relative to the halogen-free carbonate oligomer is such that the ratio of the terminal chloroformate group concentration (CF) to the halogen-containing aromatic dihydroxy compound concentration (BPX) in the halogen-free carbonate oligomer is (CF / BPX) = 10-60 (equivalent ratio), preferably 20-50 (equivalent ratio), and the terminal hydroxyl group concentration (OH) and halogen-containing aromatic dihydroxy compound concentration (BPX) in the halogen-free carbonate oligomer. ) (OH / BPX) is 4.5 to 27 (equivalent ratio), preferably 4.5 to 20 (equivalent ratio). When (CF / BPX) or (OH / BPX) is excessively large or excessively small, the polymerization reaction tends not to be completed or the introduction rate of the halogen-containing aromatic dihydroxy compound tends to decrease.

(Alkali metal or alkaline earth metal compound)
In the polymerization step to which this embodiment is applied, the halogen-containing aromatic dihydroxy compound forms an aqueous phase together with water and an alkali metal or alkaline earth metal compound. As the alkali metal or alkaline earth metal compound, a hydroxide is usually preferable, and examples thereof include sodium hydroxide, lithium hydroxide, potassium hydroxide, magnesium hydroxide, and calcium hydroxide. Among these, water is particularly preferable. Sodium oxide is preferred.
In this case, the ratio of the alkali metal or alkaline earth metal compound to the halogen-containing aromatic dihydroxy compound is preferably 1.0 to 1.5 (equivalent ratio), and more preferably 1.0 to 1.05. When the proportion of the alkali metal or alkaline earth metal compound is too small, the halogen-containing aromatic dihydroxy compound tends not to form an aqueous solution. When the proportion of the alkali metal or alkaline earth metal compound is excessively large, the solubility of the halogen-containing aromatic dihydroxy compound tends to decrease. A small amount of a reducing agent such as hydrosulfite may be added to the aqueous phase.

Examples of the alkali compound added in the polymerization step include hydroxides of alkali metals such as sodium hydroxide and potassium hydroxide, but sodium hydroxide is preferred industrially. The amount of the alkali compound used may be at least as long as the alkalinity is always maintained during the polymerization reaction. The total amount may be added all at once at the start of the polymerization reaction, and may be divided appropriately during the polymerization reaction. May be added. When the amount of the alkali compound is excessively large, the hydrolysis reaction as a side reaction tends to proceed. For this reason, the alkali compound concentration in the aqueous phase after completion of the polymerization reaction should be 0.05 N or more, preferably about 0.05 N to 0.10 N.
The amount of alkali includes the amount of excess alkali or alkaline earth metal in the alkali or alkaline earth metal salt aqueous solution of the halogen-containing aromatic dihydroxy compound.

The polymerization reaction temperature in the polymerization step is usually around room temperature, and the reaction time is about 0.5 to 5 hours, preferably about 1 to 3 hours. After completion of the polymerization reaction, washing is performed with an alkali such as sodium hydroxide until the remaining terminal chloroformate group concentration (CF) becomes 0.1 μeq / g or less.
Then, after removing impurities by performing acid washing and water washing by a conventional method, the halogen-containing polycarbonate resin in the granular form is separated by removing the organic solvent.

  As a method for obtaining a solid polycarbonate resin from an organic solvent solution of a halogen-containing polycarbonate resin, a method of evaporating an organic solvent from an organic solvent solution of a halogen-containing polycarbonate resin with a kneader (kneader method), a solvent and a non-solvent are mixed. A method of precipitating a halogen-containing polycarbonate resin, supplying an organic solvent solution of the halogen-containing polycarbonate resin to a granulation tank having a stirring blade, and heating the organic solvent in a suspended state in water to evaporate the organic solvent, thereby halogen-containing polycarbonate resin granules (Granulation method) is mentioned. Among these, the granulation method is more preferable from the viewpoints of dryability and processability such as pelletization by melt extrusion. Hereinafter, the granulation method will be described.

(Granulation method)
In the granulation method, a granulation tank having two or more stirring blades is preferably used. In a granulation tank having only one stirrer blade, although it depends on the position of the blade, block solids are generated on the lower wall surface of the granulation tank, or the flow state of the surface of the water slurry is deteriorated, resulting in block aggregation. Things may be generated and stable operation may be difficult. The shape of the stirring blade is not particularly limited, and a normal stirring blade can be used.
In addition, the presence or absence of baffle plates in the granulation tank is not particularly affected, but it is necessary to consider that there is no stagnant portion in the tank, and the baffle plate is not used or the cross section of the baffle plate is circular or elliptical. It is preferable to use a mold.

Furthermore, the supply position of the organic solvent solution of the halogen-containing polycarbonate resin is preferably water between a horizontal plane including the lower end or lower end of the stirring blade located in the upper stage and a horizontal plane including the upper end or upper end of the stirring blade located in the lower stage. . Specifically, when the interval between the two horizontal planes is h, it is preferable to select a position that is separated from the two horizontal planes by 0.1 h or more, preferably 0.2 h, more preferably between the two horizontal planes. It is good to supply near the part.
When there are three or more stirring blades, the organic solvent solution of the halogen-containing polycarbonate resin may be divided and supplied into water between the stirring blades.

The supply position of the organic solvent solution of the halogen-containing polycarbonate resin in the radial direction is 0.3d to 0.9d, preferably 0.4d to 0.8d from the center of the tank, where d is the tank radius. Position. In the portion of 0.9d to 1d, it becomes easy to produce a rock-like solidified product, and in the portion of 0 to 0.3d, the vapor of the organic solvent generated from the polymer solution is difficult to be uniformly dispersed in the tank, and the stirring shaft It becomes a bumpy state at the part, which is not preferable.
Further, when the polymer solution is supplied to the gas phase portion in the tank, it is not preferable because it forms a film on the liquid surface or causes generation of coarse aggregates.

  In the granulation tank, at least a part of the water slurry containing the polymer particles extracted from the outlet pipe is pulverized using a wet pulverizer and circulated through the circulating water slurry introduction pipe. In addition, an organic solvent solution of a halogen-containing polycarbonate resin is continuously supplied from a polymer solution introduction tube.

The position of the polymer solution introduction pipe is supplied to the middle part of the two-stage blade other than the tip of the blade of the granulation tank.
The temperature for evaporating the organic solvent in the granulation tank can be selected from the range from the azeotropic point of the organic solvent and water to the boiling point of water, but if the temperature of the granulation tank is too low, There are inconveniences such as slowing down evaporation and lowering of granulation capacity or generation of polycarbonate resin block in the tank. Conversely, if it is too high, the resulting bulk density of halogen-containing polycarbonate resin granules becomes small. Tend.

  In the case of evaporating a solvent such as methylene chloride, in the granulation tank, a solid product produced from the wet pulverized product of the halogen-containing polycarbonate resin granules circulated and the organic solvent solution of the supplied halogen-containing polycarbonate resin is used. Since the halogen-containing polycarbonate resin granule formed by combining the halogen-containing polycarbonate resin is formed, the granule is continuously extracted from the outlet tube as a water slurry containing the granule.

  The abundance of the halogen-containing polycarbonate resin granules in the granulation tank is 5 wt% to 50 wt%, preferably 10 wt% to the water slurry in the granulation tank, from the viewpoint of stirring and water slurry handling. 45 wt%, more preferably in the range of about 15 wt% to 40 wt%, the amount of the organic solvent solution of the halogen-containing polycarbonate resin introduced into the granulation tank, the amount of makeup water, and the granulation tank The amount of the halogen-containing polycarbonate resin granule-containing water slurry to be extracted is adjusted to keep the abundance of the halogen-containing polycarbonate resin granule at a constant value within the above range.

In the present embodiment, at least a part of the water slurry extracted from the outlet pipe is wet pulverized by a wet pulverizer and circulated to the granulation tank, and the product halogen-containing polycarbonate resin granule-containing water slurry is added. Extract.
As the wet pulverizer used for the wet pulverization treatment, any type can be used as long as it can pulverize the solid in the liquid. For example, a type in which the stirring blade rotates at high speed is preferable. Examples of the commercial product of the former type include Tokushu Kika Kogyo Co., Ltd., trademark, pipeline homomixer or homomic line mill, and examples of the commercial product of the latter type include trademark, disc, manufactured by Komatsu Zenoah Co., Ltd. For example, integrators.

  The pulverization by the wet pulverization treatment is preferably performed so that the halogen-containing polycarbonate resin granules in the water slurry have a particle diameter of 0.1 mm to 4 mm, preferably about 0.2 mm to 2 mm. The amount of this wet-pulverized water slurry circulated in the granulation tank is about 50 wt% to 99.5 wt%, preferably about 70 wt% to 98 wt% of the water slurry extracted from the granulation tank. If the amount of water slurry circulating in the granulation tank is excessively small, the particle size of the halogen-containing polycarbonate resin granules formed in the granulation tank tends to become gradually larger and uneven, so that the desired product is obtained. This causes inconveniences such as being unable to operate or continuous operation being impossible. On the other hand, when the amount is excessively large, the product acquisition amount tends to decrease.

  The water slurry for obtaining the halogen-containing polycarbonate resin granules of the product can be extracted from the water slurry after the wet pulverization treatment through the extraction tube, or can be extracted from the granulation tank or the outlet tube. In order to obtain the halogen-containing polycarbonate resin granule from the halogen-containing polycarbonate resin granule-containing water slurry, the granule may be separated by means such as inclination, filtration, and centrifugal separation and dried.

(Halogen-containing polycarbonate resin composition)
The halogen-containing polycarbonate resin composition to which the present embodiment is applied is obtained by adding a carboxylic acid ester and a phosphorus compound to the halogen-containing polycarbonate resin obtained by the production method described above. The composition of the present embodiment includes, as necessary, at least one auxiliary selected from an ultraviolet absorber, a flame retardant, a colorant, and an antistatic agent, as long as the object and effect of the present invention are not impaired. Then, other auxiliaries may be added.
Furthermore, the halogen-containing polycarbonate resin composition to which the present embodiment is applied has a chromaticness index b of 3.50 or less in the color difference equation of the Hunter color system Hunter after 2 days of irradiation with 25 kGy of γ-rays under oxygen interruption. Preferably, it is 3.30 or less and the change rate of haze is 10% or less, preferably 9% or less.

Here, the chromaticness index b in the Lab color system Hunter's color difference formula is obtained in accordance with JIS Z8730.
The haze (Haze) is a ratio (Td / Tt) between diffuse light transmittance (Td) and total light transmittance (Tt) (JIS K-7105).

Further, the halogen content of the halogen-containing polycarbonate resin is 0.1% by weight to 2% by weight, preferably 0.5% by weight to 1.5% by weight. Examples of the halogen include chlorine (Cl) and bromine (Br).
Next, the component mix | blended with a halogen-containing polycarbonate resin composition is demonstrated.

(Phosphorus compound)
The phosphorus compound is preferably a trivalent phosphorus compound, particularly esterified with at least one acid group of phosphorous acid having phenol and / or at least one alkyl group having 1 to 25 carbon atoms. It is preferable that the phosphite produced.

  Specific examples of the phosphite ester include, for example, 4,4′-butylidene-bis (3-methyl-6-tert-butylphenyl-ditridecyl) phosphite, 1,1,3-tris (2-methyl-4 -Ditridecyl phosphite-5-t-butylphenyl) butane, trisnonylphenyl phosphite, dinonylphenylpentaerythritol diphosphite, tris (2,4-di-t-butylphenyl) phosphite, bis (2, 4-di-t-butylphenyl) pentaerythritol diphosphite, di (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, 2,2′-ethylidene-bis (4,6 -Di-t-butylphenyl) fluorinated phosphite, 2,2'-methylene-bis (4,6-di-t-butylphenyl) o Chill diphosphite, bis (2,4-dicumylphenyl) pentaerythritol diphosphite, mono- nonylphenol and phosphite consisting dinonyl like.

  Among these phosphorus compounds, tris (2,4-di-t-butylphenyl) phosphite is particularly preferable.

  The addition amount of the phosphorus compound is 0.01 part by weight to 1 part by weight, preferably 0.01 part by weight to 0.5 part by weight with respect to 100 parts by weight of the halogen-containing polycarbonate resin. When the addition amount of the phosphorus compound is excessively large, there is a tendency to color during molding. When the addition amount of the phosphorus compound is excessively small, the effect of addition becomes insufficient. In addition, the phosphorus compounds may be used alone or in combination of two or more.

(Carboxylic acid ester)
As the carboxylic acid ester used in the present embodiment, an aliphatic carboxylic acid ester is preferable. The carboxylic acid component constituting the aliphatic carboxylic acid ester includes palmitic acid, stearic acid, valeric acid, caproic acid, capric acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, mellic acid, and tetrariacontane. Examples include acid, montanic acid, glutaric acid, adipic acid, azelaic acid and the like.
Examples of the alcohol component include various saturated or unsaturated monohydric alcohols and polyhydric alcohols.

  Specific examples of these alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, dipentaerythritol. And glycerin.

  Among these aliphatic carboxylic acid esters, glycerol fatty acid esters such as glycerol monopalmitate, glycerol monostearate, glycerol distearate, and glycerol tristearate; pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol diester Pentaerythritol fatty acid esters such as stearate, pentaerythritol tristearate and pentaerythritol tetrastearate are preferred, and glycerol monostearate and pentaerythritol tetrastearate are particularly preferred.

  The addition amount of the carboxylic acid ester is 0.01 part by weight to 1 part by weight, preferably 0.05 part by weight to 0.5 part by weight with respect to 100 parts by weight of the halogen-containing polycarbonate resin. When the amount of the carboxylic acid ester added is excessively large, decomposition gas is generated, and the haze (Haze) tends to deteriorate. When the addition amount of the carboxylic acid ester is excessively small, the releasability at the time of molding tends to deteriorate. A plurality of carboxylic acid esters can be used in combination.

(Method for producing halogenated polycarbonate resin composition)
There is no particular limitation on the timing and method of adding the above-described phosphorus compound, carboxylic acid ester, and other auxiliary agents used as necessary to the halogenated polycarbonate resin. For example, the timing of addition includes during the polymerization reaction, at the end of the polymerization reaction, before the catalyst used for the polymerization is deactivated with the catalyst deactivator and then pelletized, and during the kneading of the polycarbonate resin. It is also possible to knead the halogen-containing polycarbonate resin in a solid state such as pellets or powder and an auxiliary agent with an extruder or the like.
Among them, it is preferable to add at the time of kneading in an extruder for producing a halogen-containing polycarbonate resin composition because of good workability.

EXAMPLES Hereinafter, although this invention is demonstrated further more concretely using an Example, this invention is not limited by a following example, unless the summary is exceeded. Moreover, each measured value in an Example is calculated | required with the following method.
(1) Terminal chloroformate group concentration of carbonate oligomer (CF)
After diluting the carbonate oligomer solution with methylene chloride, aniline and pure water were added, and titration was performed with normal sodium hydroxide (NaOH) using phenolphthalein as an indicator.

(2) Terminal hydroxyl group concentration of carbonate oligomer (OH)
After diluting the carbonate oligomer solution with methylene chloride, the solution was colored by adding titanium tetrachloride and acetic acid solution, and the absorbance at a wavelength of 546 nm was measured using a spectrophotometer (Shimadzu Corporation UV-1600 type). Moreover, the extinction coefficient was calculated | required about the methylene chloride solution of bisphenol A used in the case of carbonate oligomer manufacture, and the terminal phenolic hydroxyl group (OH) density | concentration of the carbonate oligomer was measured based on these.

(3) Viscosity average molecular weight (Mv)
A halogen-containing polycarbonate resin was dissolved in dichloromethane to prepare a solution having a concentration (C) of 6.00 g / L. Next, using an Ubbelohde capillary viscometer, the flow time (t ₀ ) of the solvent (dichloromethane) and the flow time (t) of the sample solution were measured in a constant temperature water bath set at 20.0 ° C., and the intrinsic viscosity was measured. [Η] was determined.
Subsequently, based on these measured values, the viscosity average molecular weight (Mv) was calculated according to the following formulas (i) to (vi).
(I) η _sp = (t / t ₀ ) -1
(Ii) C = 6.00 (g / L)
(Iii) a = 0.28 × η _sp +1
(Iv) b = 10 × (η _sp / C)
(V) [η] = b / a
(Vi) Mv = 51400 × [η] exp 1.205

(4) Terminal chloroformate group concentration (CF) of halogen-containing polycarbonate resin
About 1 g of halogen-containing polycarbonate resin is precisely weighed, 20 ml of methylene chloride is added and dissolved, and 2 ml of 4- (pnitrobenzyl) pyridine (concentration: 1% by weight methylene chloride solution) is added to cause color development. Absorbance at a wavelength of 440 nm was measured using a meter (UV-1600 manufactured by Shimadzu Corporation). In addition, the extinction coefficient was determined using a methylene chloride solution of phenyl chloroformate, and the amount of chloroformate group of the halogen-containing polycarbonate resin was determined based on these measured values.

(5) Halogen content of halogen-containing polycarbonate resin (bromine atom content)
About 1 g of halogen-containing polycarbonate resin was precisely weighed, dissolved in 25 ml of tetrahydrofuran, and then measured by fluorescent X-ray (SEA2010L type).

(6) Hue of the polycarbonate resin containing halogen In accordance with JIS Z8722, the halogen-containing polycarbonate resin composition before and after γ-ray irradiation at 25 kGy was dried at 130 ° C. for 5 hours, and then injected at 360 ° C. with an injection molding machine. Each press sheet having a thickness of 100 mm, a width of 100 mm, and a thickness of 3 mm was molded, and a chromaticness index b in a Lab color difference Hunter color difference equation was measured using a color tester (CM-3700d manufactured by Konica Minolta, Inc.). (Unit: None).

(7) Haze of halogen-containing polycarbonate resin (cloudiness value: Haze)
In accordance with JIS K-7105, the halogen-containing polycarbonate resin composition before and after γ-ray irradiation of 25 kGy was dried at 130 ° C. for 5 hours, injected at 360 ° C. using an injection molding machine, and 100 mm in length. Press sheets each having a width of 100 mm and a thickness of 3 mm were molded, and the Haze change rate before and after γ-ray irradiation was determined from the Haze values measured using a haze meter (NDH-1001DP type manufactured by Nippon Denshoku Co., Ltd.) ( unit%). The smaller this value, the better the ionizing radiation resistance.

Example 1
In a 700 L dissolution tank equipped with a 700 L stirring blade and jacket, 100 kg of BPA, 145 kg of 25 wt% sodium hydroxide aqueous solution and 496 kg of demineralized water were dissolved at 35 ° C. in the presence of 0.11 kg of hydrosulfite, and BPA alkaline aqueous solution (water Phase) was prepared. Next, this BPA aqueous alkali solution (aqueous phase) was supplied to a stainless steel pipe having an inner diameter of 6 mm and an outer diameter of 8 mm at a flow rate of 119 kg / hour.
At the same time, methylene chloride (organic phase) at 20 ° C. is supplied to the stainless steel pipe at a flow rate of 59.2 kg / hour, and the BPA alkaline aqueous solution (aqueous phase) and methylene chloride (organic phase) are mixed in the stainless steel pipe. did.
Subsequently, this mixture is emulsified using a homomixer (product name: TK Homomic Line Flow LF-500, manufactured by Tokushu Kika Co., Ltd.), and BPA alkaline aqueous solution (aqueous phase) and methylene chloride (organic phase). An emulsion of the mixture with was prepared.

  Next, an emulsion of BPA alkaline aqueous solution (aqueous phase) and methylene chloride (organic phase) is taken out from the homomixer through a pipe having an inner diameter of 6 mm × an outer diameter of 8 mm, and then connected to this pipe with an inner diameter of 6 mm × length. It was introduced into a 34 m pipe reactor (made of polytetrafluoroethylene). Further, liquefied carbonyl chloride is supplied at a flow rate of 8.52 kg / hour through a pipe (cooled to 0 ° C.) separately connected to this pipe reactor, and the aforementioned BPA alkaline aqueous solution (aqueous phase) / methylene chloride (organic phase) milk is supplied. The suspension and liquefied carbonyl chloride were contacted.

The emulsion described above was contacted with liquefied carbonyl chloride while flowing through the pipe reactor at a linear velocity of 1.7 m / sec for 20 seconds, and chloroformation and oligomerization reactions were performed.
In this case, the reaction temperature was adjusted to 60 ° C., respectively, and each was externally cooled to 35 ° C. before entering the next oligomerization tank. The oligomerized emulsion thus obtained from the pipe reactor is further introduced into a reaction vessel equipped with a stirrer having an internal volume of 50 liters, stirred at 30 ° C. in a nitrogen gas atmosphere, and oligomerized, whereby an aqueous phase is obtained. The Na salt of unreacted BPA present therein was completely consumed, and then the aqueous phase and the organic phase were separated by standing to obtain an oligomeric methylene chloride solution. In the oligomerization, 0.273 kg of a 2% aqueous solution of triethylamine (hereinafter referred to as “2% TEA”) and a 16% methylene chloride solution of pt-butylphenol (hereinafter referred to as “16% PTBP”) were respectively added. Per hour, added to the oligomerization tank at 2.57 kg / hour. The terminal chloroformate group concentration (CF) and the terminal hydroxyl group concentration (OH) at this time are shown in Table 1.

  While charging 65.5 kg of the above-described oligomeric dichloromethane solution and 34.8 kg of diluting dichloromethane into a reaction vessel equipped with an internal volume of 200 L with a Faudler blade, this was previously mixed with 17.4 kg of demineralized water and 25 wt% aqueous sodium hydroxide solution. A mixture of 53 kg, 0.270 kg of tetrabromobisphenol (TBA) and 0.317 kg of a 2 wt% triethylamine aqueous solution was added and stirred at 25 ° C., and a copolymerization reaction was carried out for 120 minutes.

  After completion of the copolymerization reaction, 34.9 kg of dichloromethane and 8.00 kg of demineralized water were added, stirred for 30 minutes, washed, and then stopped, and the organic phase (I) and the aqueous phase were separated using a centrifuge. Separated. 30 kg of 0.1N hydrochloric acid was added to the separated organic phase (I), and the mixture was stirred for 30 minutes to extract triethylamine and a small amount of remaining alkali components, and then the stirring was stopped to separate the aqueous phase from the organic phase (II). . Further, 30 kg of demineralized water was added to the separated organic phase (II) and stirred for 30 minutes, and then the stirring was stopped to separate the aqueous phase and the organic phase (III). Subsequently, 30 kg of demineralized water was added to the organic phase (III) again and stirred for 30 minutes, and then the stirring was stopped to separate the aqueous phase and the organic phase (IV).

  While continuously supplying 20 liters / hour of a halogen-containing polycarbonate resin dichloromethane solution to a jacketed granulation tank having an internal volume of 50 liters equipped with a four-stage turbine blade two-stage stirrer, as makeup water Introducing 30 liters / hour of water at 45 ° C. and evaporating methylene chloride at an internal temperature of 47 ° C. and a stirring speed of 400 rpm while maintaining a suspended state in water to form halogen-containing polycarbonate resin granules.

  Next, a part of the water slurry containing the halogen-containing polycarbonate resin granules extracted from the granulation tank is wet-pulverized, and 35 liters / hour of water slurry is extracted while circulating in the granulation tank. Things were kept at 50 liters. The granular polycarbonate resin obtained by this method has a large bulk density, and the desired halogen-containing polycarbonate resin granular material can be obtained stably without the occurrence of adhesion and aggregation of particles and generation of block-like solids in the granulation tank. .

  The extracted water slurry was separated from the polycarbonate resin granules by filtration and dried in a clean oven at 140 ° C. for 48 hours. Table 1 shows the viscosity average molecular weight (Mv) and bromine (Br) concentration of the obtained polycarbonate resin.

Next, with respect to 100 parts by weight of the dried halogen-containing polycarbonate resin granules, 0.5 part by weight of polypropylene glycol (Mw = 2,000), phosphorus compound (tris (2,4-di-tert-butylphenyl) phosphine). Phyte) 0.05 parts by weight, carboxylic acid ester (glycerin monostearate) 0.1 parts by weight, 1,4-bis (2,6-diethyl-4-hydroxyphenyl) aminoanthraquinone 1.5 × 10 ⁻⁵ weights It was added at parts and 1,8-bis (p- methyl) phenyl anthraquinone 1.5 × 10 ^-5 parts by a twin-screw extruder, by melt kneading, to prepare a halogen-containing polycarbonate resin composition. Table 1 shows the chromaticness index b and haze (haze) change rate according to Hunter's color difference formula in the Lab color system 2 days after γ-ray irradiation for the prepared halogen-containing polycarbonate resin composition.

(Comparative Example 1)
According to Example 1 ((0058) column) of JP-A-2005-179549, a halogen-containing polycarbonate resin obtained by polymerizing the following (i) halogen-free BPA and (ii) halogen-containing BPA was obtained. Thereafter, a halogen-containing polycarbonate resin composition was prepared by the same operation as in Example 1 using a twin-screw extruder. Table 1 shows the b value and Haze change rate of the obtained composition.
(I) A halogen-free BPA having a number average molecular weight (Mn) of 650 and a ratio of terminal chloroformate group concentration (CF) to terminal hydroxyl group concentration (OH) (CF / OH) of 4.0.
(Ii) Number average molecular weight (Mn) 3891, ratio of terminal chloroformate group concentration (CF) to terminal hydroxyl group concentration (OH) (CF / OH) 22.4, bromine (Br) content 14.4 weight % Halogen-containing BPA.

(Comparative Example 2)
Terminal chloroformate group concentration (CF), terminal hydroxyl group concentration (OH), ratio of terminal chloroformate group concentration (CF) to terminal hydroxyl group concentration (OH) (CF / OH), and The amount of TBA added was changed as shown in Table 1, and the amounts of water and alkali were adjusted so that the amount of residual alkali at the end of polymerization was equivalent to that in Example 1. Otherwise, the same as in Example 1 The operation was performed to prepare a halogen-containing polycarbonate resin composition. Table 1 shows the b value and Haze change rate of the obtained composition.

(Comparative Example 3)
The addition amount of TBA was adjusted to the ratio shown in Table 1, and the other operations were performed in the same manner as in Example 1 to prepare a halogen-containing polycarbonate resin composition. The resulting halogen-containing polycarbonate resin did not increase in molecular weight even after 120 minutes of polymerization reaction. Table 1 shows the b value and Haze change rate of the obtained composition.
In Table 1, TBA represents the concentration of tetrabromobisphenol A, which is a halogen-containing aromatic dihydroxy compound, and corresponds to the halogen-containing aromatic dihydroxy compound concentration (BPX).

From the results of Table 1, the halogen-containing polycarbonate resin composition to which this embodiment is applied (Example 1) shows a numerical value with a small b value after γ-ray irradiation and a small Haze change rate before and after γ-ray irradiation. It turns out that ionizing radiation property is favorable.
On the other hand, the ratio of terminal chloroformate group concentration (CF) to tetrabromobusphenol concentration (TBA) (CF / TBA) and the ratio of terminal hydroxyl group concentration (OH) to tetrabromobusphenol concentration (TBA) (OH / TBA) is an excessively small condition (Comparative Example 1), it can be seen that the rate of change in Haze increases and ionizing radiation resistance is not improved.
It can also be seen that when both (CF / TBA) and (OH / TBA) are excessively large (Comparative Example 3), the desired polymer cannot be obtained.
Furthermore, when the terminal chloroformate group concentration (CF), the terminal hydroxyl group concentration (OH), and (CF / OH) are too small (Comparative Example 2), the Haze change rate is increased, and the ionizing radiation resistance is increased. It turns out that it is not improved.

  As described above in detail, it is possible to efficiently produce a halogen-containing polycarbonate resin excellent in color tone stability upon irradiation with ionizing radiation by the method for producing a halogen-containing polycarbonate resin to which the present embodiment is applied. Using this, it can be used for various medical instruments such as housing materials for artificial dialysis.

Claims (4)

A method for producing a halogen-containing polycarbonate resin used in a halogen-containing polycarbonate resin composition,
An oligomer synthesis step of synthesizing a carbonate oligomer by reacting an alkali metal compound or alkaline earth metal compound of an aromatic dihydroxy compound containing no halogen with carbonyl chloride;
A polymerization step of polymerizing the carbonate oligomer synthesized by the oligomer synthesis step and a halogen-containing aromatic dihydroxy compound and / or an alkali metal compound or an alkaline earth metal compound of the halogen-containing aromatic dihydroxy compound,
The ratio (CF / BPX) of the terminal chloroformate group concentration (CF) and the halogen-containing aromatic dihydroxy compound concentration (BPX) in the carbonate oligomer in the polymerization step is 10 to 60 (equivalent ratio), and The ratio (OH / BPX) of the terminal hydroxyl group concentration (OH) and the halogen-containing aromatic dihydroxy compound concentration (BPX) in the carbonate oligomer is 4.5 to 27 (equivalent ratio), and
The ratio (CF / OH) of the terminal chloroformate group concentration (CF) in the carbonate oligomer to the terminal hydroxyl group concentration (OH) in the carbonate oligomer is 1.5 to 3.0 (equivalent ratio). A method for producing a halogen-containing polycarbonate resin. The carbonate oligomer, method for producing the halogen-containing polycarbonate resin according to claim 1, characterized by having a repeating unit represented by the structural formula (1).

The method for producing a halogen-containing polycarbonate resin according to claim 1 or 2, wherein the halogen-containing aromatic dihydroxy compound is tetrabromobisphenol A represented by the compound (2).

The method for producing a halogen-containing polycarbonate resin according to any one of claims 1 to 3, wherein the halogen content of the halogen-containing polycarbonate resin is 0.1 wt% to 2 wt%.