JP2004018624A - Method and apparatus for producing aromatic polycarbonate resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a polycarbonate resin which has an excellent reaction yield, reduced amounts of terminal chloroformate group and terminal OH group as qualities of obtained polycarbonate, excellent heat stability during molding and dry-heat discoloration resistance of molding by completing a condensation polymerization reaction by a simple method and facilities in a short time and facilities therefor. <P>SOLUTION: In the method for continuously producing the polycarbonate resin by reacting an alkaline aqueous solution of dihydric phenol with phosgene in the presence of an organic solvent to form a carbonate oligomer reaction solution and then carrying out an interfacial condensation polymerization reaction, the oligomer reaction solution is made into a water-in-oil type emulsified state, the interfacial condensation polymerization reaction is carried out while maintaining the emulsified state in a laminar flow by a tubular reactor and a condensation polymerization catalyst is added in the middle of the tubular reactor. The production apparatus comprises facilities for mixing molecular weight adjuster with the alkaline aqueous solution, emulsion facilities for emulsifying the reaction solution in a highly emulsified state and the tubular reactor with a heat insulating material equipped with a device for adding and mixing the catalyst in the middle of the facilities. <P>COPYRIGHT: (C)2004,JPO

Description

【０１０８】
【発明の効果】
従来、ポリカーボネートの縮重合反応は、攪拌機付き多段反応槽や、スタティックミキサー、オリフィスミキサーなどを具備した管型反応器のような攪拌装置を用いて実施していたが、本発明の縮重合反応によればそのような攪拌装置を排除した、攪拌機能のない管型反応器を用いて、その中に乳化状反応液を層流で流し触媒を添加するのみの簡単な設備・方法によって、たいへん短時間に縮重合反応を完了することができ、且つ反応収率に優れ、また得られるポリカーボネートの品質としてポリマー中の残存クロロホーメート基量や末端ＯＨ基量が少なく、成形時の熱安定性に優れ、更に成形品の乾熱着色の少ない耐熱性の良好なポリカーボネートを容易にかつ設備コストを安価に製造することが出来、本発明の工業的価値は極めて大きい。
【図面の簡単な説明】
【図１】カーボネートオリゴマー製造装置を示す図である。
【図２】本発明（および一部比較例）のポリカーボネート連続縮重合反応装置を示す図である。
【図３】比較例のポリカーボネート連続縮重合反応装置を示す図である。
【図４】本発明のポリカーボネート連続縮重合反応装置（実施例４）を示す図である。
【図５】本発明の乳化機および触媒添加設備の一例を示す図である。
【図６】本発明の乳化機および触媒添加設備の一例を示す図である。
【符号の説明】
１．　第１反応器（図−１）
２．　第２反応器
３．　循環ポンプ
４．　熱交換器
５．　オーバーフロー配管（第１反応器）
６．　オーバーフロー配管（第２反応器）
７．　一部循環配管
８．　ビスフェノールＡの苛性ソーダ水溶液投入配管
９．　ホスゲン投入配管
１０．　塩化メチレン投入配管
１１．　循環配管
１５．カーボネートオリゴマー反応液投入配管（図−２、図−３、図−４）
１６．分子量調節剤投入配管
１７．苛性ソーダ水溶液投入配管
２１．受け容器
２２．送液ポンプ
２３．乳化機
２３ａ．流路ａの乳化機（図−４）
２３ｂ．流路ｂの乳化機（図−４）
２３−１．スタティックミキサー（乳化機）（図−５）
２３−２．ホモミキサー（乳化機）（図−６）
２４．管型縮重合反応器（保温材付き）
２５．スタティックミキサー（反応液攪拌・混合用）（図−３）
２６ａ．反応液流路ａ（図−４）
２６ｂ．反応液流路ｂ（図−４）
２７Ａ．　Ａ点触媒添加装置（管容量１０％点）
２７Ｂ．　Ｂ点触媒添加装置（管容量５０％点）
２７Ｃ．　Ｃ点触媒添加装置（管容量６５％点）
２７Ｄ．　Ｄ点触媒添加装置（管容量８０％点）
２７−１．圧入式触媒添加装置（図−５）
２７−２．ポット式触媒添加装置（図−６）
２８−１．触媒添加配管（図−５）
２８−２．触媒添加配管（図−６）
２８−Ｐ．触媒圧入用ポンプ（図−５）
２９．反応液送液ポンプ（図−６）
３０−１．サンプリングノズル（管型反応器最前部に設置）
３０−２．サンプリングノズル（管型反応器中間部、前方より６０％点に設置）
３０−３．サンプリングノズル（管型反応器最後部：重合反応終了点）
３１．希釈用塩化メチレン投入配管[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing an aromatic polycarbonate and an apparatus for producing the same, and more particularly to an efficient method for producing a high-molecular-weight polycarbonate resin having excellent heat resistance and an apparatus for producing the same.
[0002]
[Prior art]
When polymerizing a high molecular weight polycarbonate resin, a method of performing polymerization in an emulsified state is well known.
[0003]
For example, it is disclosed in Japanese Patent Publication No. 37-2198. In this method, after the oligomer solution is emulsified, the polymerization reaction is carried out in an emulsified state under stirring at 120 to 300 rpm in a reaction vessel equipped with a stirrer, and a high-molecular-weight polycarbonate is formed more quickly than the polymerization reaction in a non-emulsified state. On the other hand, it has the advantage of forming an extremely stable emulsified state, requiring much effort to separate and purify impurities from the polymer solution after the reaction is completed, and the resulting product has a large amount of polymer terminal OH groups remaining. And has a drawback of poor dry heat resistance. There is also a disadvantage that the polymerization time is 2-3 hours and a long time is required.
[0004]
Japanese Patent Application Laid-Open No. Hei 4-277521 discloses a method of maintaining a good emulsified state by emulsifying an oligomer solution and then allowing it to stand without stirring to advance the polymerization reaction to obtain a polycarbonate resin. Have been. In this method, a molecular weight regulator is added to an oligomer solution obtained by reacting an alkaline aqueous solution of a dihydric phenol with phosgene in the presence of an organic solvent, and the reaction mixture is stirred to be emulsified, and then left to stand. The OH / CO value calculated from the absorbance ratio of the OH group at the polymer terminal to the CO group in the main chain by an infrared spectrophotometer is 0.12 to 0. It was described that 20 PCs were obtained, and the unreacted bisphenol A concentration in the aqueous phase at the end of the reaction was 0.6 to 1.2 g / L.
[0005]
However, in such a polymerization method, the reaction time required for the polymerization is as long as 2 hours, and the concentration of unreacted bisphenol A in the polymer terminal OH group and the aqueous phase is not yet sufficient, and there is room for improvement such as the dry heat resistance of the polymer. It is a batch type reaction and has many problems such as lack of productivity.
[0006]
A polymerization reaction of a methylene chloride solution of a carbonate oligomer prepared in advance and an alkali solution of a dihydric phenol is carried out in a multiphase flow forming region provided with a mixing means such as a multistage orifice, and the reaction solution has no orifice when the viscosity of the reaction solution increases. A continuous production method and apparatus for terminating the reaction by flowing the laminar flow in a laminar flow forming region is disclosed in Japanese Patent Application Laid-Open No. 50-22089 (Japanese Patent Publication No. 52-36554). Specifically, in all of the examples, triethylamine as a catalyst was added to the oligomer mixture before the polymerization reaction, and thereafter the polymerization reaction was performed as a mixed phase flow. Although there is a description that the molecular weight distribution is narrowed, there is no specific and quantitative description of characteristic values related to heat resistance, such as a terminal chloroformate group and a terminal OH group. Since the catalyst is added at an earlier time, the decomposition reaction of the chloroformate group by the alkali often occurs, and the number of OH groups at the polymer terminal increases, thereby deteriorating the dry heat resistance. Also, there is a problem that thermal stability is deteriorated by a by-product of the reaction between an amine and a chloroformate. Furthermore, the installation of a cooling device increases the cost of equipment and operation.
[0007]
In JP-A-04-255718 (Japanese Patent Publication No. 7-49475), a mixed solution of a terminal stopper, a base, water, an organic solvent, a catalyst and a carbonate oligomer is formed into a fine dispersion by a static mixer. A method for producing a polycarbonate which reacts in a residence zone and repeats this step is disclosed. The features of this method are a combination of a static mixer and a retention zone, in which the mixing is aggressively followed by a residence, and this is repeated to advance the reaction, and the catalyst is added prior to the polymerization reaction.
[0008]
It is described that this method is efficient, such as a short polymerization reaction time of 3.5 minutes and a good conversion of bisphenol A and phenol. No specific or quantitative description of characteristic values related to gender was found. Since the catalyst is added at an early stage, the decomposition reaction of the chloroformate group due to the alkali frequently occurs, and the number of OH groups at the polymer terminal increases, which adversely affects the dry heat resistance. Further, the formation of urethane bonds due to the side reaction between the amine and the chloroformate, and the fact that a large amount of free bisphenol A is contained in the polymer cause problems in heat stability such as coloring during the high-temperature molding of polycarbonate.
[0009]
In Japanese Patent Application Laid-Open No. 08-325371, a carbonate oligomer reaction liquid is emulsified in a water-in-oil state, and after passing through orifice holes and staying in pipes repeatedly, a catalyst is added. A method for carrying out the reaction is disclosed, which is characterized in that the reaction solution is subjected to strong stirring and mixing by passing through an orifice hole to cause a reaction. However, in this method, coalescence due to the collision of the dispersed droplets works by vigorous stirring and mixing, which leads to an increase in the size of the droplets and the destruction of the emulsified state, that is, a significant decrease in the boundary area between the aqueous phase and the organic phase. In addition, the partitioning effect of the orifice leads to partial stagnation of the reaction solution and a short path, and the quality tends to be unstable. Also, since many orifices are installed, the equipment is complicated, and equipment costs such as measures for preventing liquid and gas leaks are high.
[0010]
[Problems to be solved by the invention]
An object of the present invention is to provide a method for efficiently producing a polycarbonate resin having a small amount of residual chloroformate groups and terminal OH groups in a polymer and having excellent heat resistance with simple equipment.
[0011]
The present inventors differ from the method in which the carbonate oligomer reaction liquid is emulsified and then left standing without stirring in the tank to maintain the emulsification and advance the reaction, or alternatively, a static mixer and a retention zone are combined. During the process, unlike the method of continuously aggressively mixing and retaining the carbonate oligomer reaction solution to advance the reaction, the present invention employs a tube type without stirring function after continuously emulsifying the carbonate oligomer reaction solution. The polycondensation reaction is carried out in a laminar flow in the reactor while maintaining the emulsified state, and the catalyst is added in the middle of the tubular reactor to complete the polycondensation reaction in a very short time, Investigating the surprising fact that the amount of residual chloroformate group and the amount of terminal OH groups are small, a polycarbonate resin excellent in heat resistance is obtained, and the yield is also improved, Invention has been reached.
[0012]
[Means for Solving the Problems]
SUMMARY OF THE INVENTION The present invention provides a method and apparatus for efficiently producing a high molecular weight polycarbonate resin having little coloring and excellent heat stability and dry heat resistance during molding with simple equipment.
[0013]
That is, the gist of the present invention is a method for continuously producing a polycarbonate resin by performing an interfacial polycondensation reaction after forming a carbonate oligomer reaction solution by reacting an aqueous alkali solution of dihydric phenol and phosgene in the presence of an organic solvent. After the oligomer reaction liquid is brought into a water-in-oil type emulsified state, an interfacial polycondensation reaction is carried out while maintaining the emulsified state in a laminar flow using a tubular reactor, and from the inlet of the tubular reactor. A continuous method for producing a polycarbonate resin, characterized in that a condensation polymerization catalyst is added up to a position corresponding to two thirds of the total capacity of the tubular reactor.
[0014]
ADVANTAGE OF THE INVENTION According to this invention, the amount of residual chloroformate groups and the amount of terminal OH groups in a polymer are small, and a polycarbonate resin excellent in heat stability and dry heat resistance can be efficiently produced with simple equipment.
[0015]
Hereinafter, the present invention will be described in more detail.
[0016]
The dihydric phenol used in the present invention includes, for example, dioxydiphenylalkanes such as 2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as bisphenol A), dioxydiphenylcycloalkanes, dioxydiphenyl Arylalkanes, dioxydiphenyl ethers, dioxydiphenyls, dioxydiphenylsulfones, dioxydiphenylsulfides, dioxydiphenylsulfoxides, dioxydiphenylcarbonyls, dioxydiphenylcarboxyls, dioxydiphenylfluorenes, And halogen- or alkyl-substituted derivatives thereof, or mixtures thereof. In addition, a part of these dihydric phenols can be used by replacing them with polyfunctional compounds such as phloroglucin, trisphenol, 2,4-dihydroxybenzoic acid and diphenolic acid.
[0017]
These dihydric phenols are used after being dissolved in an aqueous alkali solution. In this case, as the alkali, an alkali metal hydroxide such as caustic soda and caustic potash is preferably used, and the alkali concentration in the aqueous solution is preferably 5 to 10% by weight. The molar ratio of the dihydric phenol to the alkali to be dissolved is preferably from 1: 1.8 to 1: 3.5, more preferably from 1: 2.0 to 1: 3.2. The concentration of the aqueous alkali solution of dihydric phenol is preferably from 150 to 180 g / L from the viewpoint of solubility. It is also possible to add and use a part of the alkali after the phosgenation reaction. In order to prevent oxidative coloring of the dihydric phenol, the reaction may be performed under a nitrogen atmosphere, or a reducing agent such as sodium bisulfite or hydrosulfite may be added as an antioxidant.
[0018]
Further, an organic solvent is used to facilitate the phosgenation reaction and the polymerization reaction. The organic solvents used are organic compounds which are substantially insoluble in water and inert to the reaction and which dissolve phosgene and polycarbonate. For example, chlorinated aliphatic hydrocarbons such as dichloromethane (also called methylene chloride), tetrachloroethane, 1,2-dichloroethylene, chloroform, trichloroethane and dichloroethane; chlorination of chlorobenzene, dichlorobenzene, chlorotoluene and the like Aromatic hydrocarbons: acetophenone, cyclohexane, anisole, etc., and these solvents alone or in a mixture can be used. Of these, dichloromethane (methylene chloride) is the most preferred and common. Although the amount of the solvent used is not particularly limited, the concentration of the produced polycarbonate is about 8 to 30% by weight.
[0019]
For the purpose of controlling the molecular weight of the resulting polycarbonate, a molecular weight regulator is generally used. Examples of the molecular weight regulator include monohydric phenols such as phenol, p-cresol, p-tert-butylphenol, and cumylphenol; monohydric alcohols such as methanol, ethanol, and cyclohexanol. Is preferably after the end of the phosgenation reaction, and the amount of addition varies depending on the desired molecular weight, but is usually about 0.001 to 0.2 mol per 1 mol of dihydric phenol.
[0020]
The viscosity average molecular weight of the polycarbonate obtained by the present invention is from 10,000 to 100,000, preferably from 12,000 to 50,000, more preferably from 13,000 to 40,000. The term "carbonate oligomer" in the present invention has a relative viscosity ηrel of about 1.15 or less. (The viscosity average molecular weight and the relative viscosity will be described in Examples below).
[0021]
A method of obtaining a carbonate oligomer by a phosgenation reaction by introducing phosgene can be performed under conventionally well-known conditions. For example, a method of introducing and reacting phosgene with stirring of an aqueous alkali solution of a dihydric phenol and an immiscible organic solvent (Japanese Patent Publication No. 37-2198), introducing an alkali aqueous solution of a dihydric phenol and an organic solvent into a tubular reactor. A method of forming a mixed phase flow, introducing phosgene into the mixed solution and reacting it (Japanese Patent Publication No. 46-21460), an aqueous solution of dihydric phenol, an organic solvent, and phosgene so that the dihydric phenol has a specific concentration. The carbonate oligomer can be obtained by a method such as a method of supplying a cooled circulating reaction mixture with a reaction (Japanese Patent Publication No. 6-55810).
[0022]
The phosgene to be introduced is used in a liquid or gaseous state, alone or as a solution in an organic solvent. The preferred amount used in the continuous phosgenation reaction is affected by the reaction conditions, particularly the temperature of the phosgenation reaction and the concentration of the alkaline aqueous solution of dihydric phenol, and when the temperature exceeds 25 ° C or the concentration is less than 55 g / L. In this case, the number of moles of phosgene per mole of dihydric phenol exceeds 1.2 moles, and often exceeds 1.3 moles, but under normal conditions, 1.0 to 1.2 moles is sufficient. And more preferably 1.05 to 1.15 mol.
[0023]
The addition of the molecular weight modifier to the reaction system is performed after the completion of the phosgenation reaction in order to suppress the formation of a low molecular weight compound due to the reaction between the molecular weight modifier and phosgene or a chloroformate compound of bisphenol A. It is preferable to add during the early stage of the reaction.
[0024]
In the method of the present invention, a carbonate oligomer is formed by a phosgenation reaction, and then, if necessary, a molecular weight modifier and / or an aqueous alkali solution are added to the oligomer reaction solution. An emulsified type and a highly emulsified state in which the droplet size of the dispersed aqueous phase is small. In this case, an important condition for obtaining a good emulsified state is a ratio of the organic phase to the aqueous phase in the reaction solution. The ratio is preferably from 0.1 to 3.0, more preferably from 0.5 to 2.5, based on the volume ratio of the organic phase to the organic phase of 1.0.
[0025]
There are various methods for bringing the reaction solution into a water-in-oil type emulsified state, such as a method of adding an aqueous alkali solution with stirring, a method of changing the stirring speed, and a method of injecting the reaction solution into an organic phase with stirring. . It is possible to emulsify by using a simple stirrer (propeller, turbine, anchor type wing, chi type wing, etc.) at a high rotation speed, but the degree of emulsification is limited. Examples of devices for obtaining a higher emulsified state include dynamic emulsifiers for high-speed stirring such as homogenizers, mixers, homomixers, colloid mills, and flow jet mixers, and static mixers, orifice mixers, and ultrasonic emulsifiers. Static emulsifiers are suitable, and when they are used, a highly emulsified state with a fine droplet diameter can be obtained as compared with an emulsified state with a droplet diameter obtained with a simple stirrer. In the method of the present invention, using the latter advanced emulsification apparatus alone or in combination, and if necessary, using a simple stirrer in the former stage, and continuously flowing the reaction solution to these emulsification facilities, An emulsified state can be obtained.
[0026]
The average droplet diameter of the dispersed aqueous phase of the water-in-oil type emulsion obtained by the emulsification equipment is preferably from 5 μm to 50 μm, more preferably from 10 μm to 40 μm. That is, since the average droplet size of the dispersed aqueous phase and the total interfacial area between the aqueous phase and the organic phase are almost inversely proportional, the miniaturization of the average droplet size is caused by the polycondensation reaction of polycarbonate which is an interfacial reaction. It directly affects speed.
[0027]
In order to improve the interfacial polycondensation reaction rate, the droplet diameter is preferably set to 50 μm or less, and more preferably 40 μm or less. However, there is a problem in miniaturization of the droplet diameter. When the diameter is smaller than 5 μm, the reaction rate is too fast and side reactions increase, and it becomes difficult to control the polycondensation reaction. And the like, and a power for stirring the reaction solution is required for miniaturization, and when it is smaller than 5 μm, the stirring energy per unit volume becomes excessive. Therefore, the droplet diameter is preferably 5 μm or more, more preferably 10 μm or more.
[0028]
Next, the reaction liquid in a highly emulsified state is, in a conventionally known polymerization method, a method of continuously stirring in a reaction tank as it is, a method of allowing the reaction liquid to stand without stirring in the reaction tank, and a method of stirring in a continuous multi-stage reaction tank. And a method of forming a fine dispersion and continuously flowing the mixture in a tubular reactor in which a static mixer and a retention zone are combined. However, the method of the present invention is a method in which a highly emulsified reaction liquid is continuously flowed in a laminar flow through a tubular reactor having no stirring function to carry out a condensation polymerization reaction.
[0029]
In addition, a conventionally known polymerization method using a continuous tubular reactor uses a static mixer or the like, and is intended to improve the contact between the aqueous phase and the organic phase by forcibly stirring. It has a great effect on the coalescence of the droplets and the effect of breaking the emulsified state, leading to a reduction in the area of the reaction interface between the aqueous and organic phases due to the droplet size and amount of the dispersed aqueous phase, thereby facilitating the interfacial polycondensation reaction. I can't do that.
[0030]
On the other hand, the feature of the polycondensation method using the continuous tubular reactor of the present invention is that the polymerization reaction proceeds continuously in a laminar flow in a tubular reactor having no stirring function as described above. In other words, it is possible to maintain a highly emulsified state by eliminating stirring, and it is possible to maintain the reaction interface area between the aqueous phase and the organic phase due to the droplet size and amount of the dispersed aqueous phase, and to carry out the interfacial polycondensation reaction. Can proceed smoothly.
[0031]
Next, the simplest form of the tubular reactor may be a tube having a circular cross section, or may be a tube having a rectangular cross section such as a square or hexagon. In order to flow the reaction liquid in an emulsified state by a piston flow method and to improve equipment efficiency, the ratio of the diameter of the tube to the length of the tube of the tube reactor is preferably from 1: 150 to 1: 7000, more preferably from 1: 150. 500-1: 3000 is more preferable. Further, a simple tubular reactor having no stagnation portion may be used in order to flow by the piston flow method. However, a hindrance used in a range that does not substantially hinder the manifestation of the effects of the present invention, that is, in a laminar flow range of Re number of 2000 or less. It is possible to install a plate, a partition plate, etc. in a tubular reactor. The material constituting the reactor may be a commonly used material such as SUS304 stainless steel and glass-lined steel.
[0032]
The present invention proposes an efficient method for controlling the condensation polymerization reaction temperature. A conventional method of controlling the polymerization reaction temperature is generally a method of installing a jacket or the like in a polymerization facility and cooling or heating the same, but the method of the present invention controls the raw material temperature to a predetermined temperature, and replaces the jacket or the like. This is a method using a heat insulating material. That is, the temperature of the oligomer reaction solution is controlled, and in the subsequent interfacial polycondensation reaction, the target temperature is reached by the heat generated by the reaction and the heat generated by the power energy of the liquid feed pump and the emulsifier, etc. In this method, the condensation polymerization temperature is maintained within a predetermined range only by keeping the temperature without forcibly cooling and / or heating from the outside. In the polycondensation reaction of polycarbonate, under constant reaction conditions, the heat generated by the polymerization reaction and the heat generated by the kinetic energy are almost constant, and if the temperature of the raw material system is kept constant, appropriate heat insulation by a heat insulator in the tubular polymerization reactor By carrying out (1), the amount of heat release or heat absorption can be kept small and almost constant, and as a result, the middle and final polymerization reaction temperature can be maintained in a constant temperature range.
[0033]
In one embodiment, the temperature becomes 24 ° C. when the molecular weight regulator and the aqueous alkali solution are mixed with the oligomer reaction solution at the end of the phosgenation reaction at a temperature of 20 ° C., and can be maintained at the target of 30 ± 1 ° C. at the end of the polymerization reaction of the present invention. .
[0034]
The temperature range of the polycondensation reaction in the present invention can be from 20 to 40 ° C, preferably from 24 to 36 ° C, more preferably from 28 to 34 ° C. In order to achieve this temperature, the temperature of the oligomer reaction solution is preferably from 10 to 30 ° C, and the temperature of the reaction solution containing the molecular weight regulator and the aqueous alkali solution is preferably from 15 ° C to 35 ° C.
[0035]
The material of the heat insulating material for preventing heat radiation or heat absorption includes calcium silicate, rock wool, glass wool, urethane foam, polystyrene foam, and the like, and these can be used.
[0036]
By adopting this reaction temperature maintaining method, equipment costs such as a jacket and heating / cooling equipment are not required (heat insulating equipment cost is required), and operating power cost for heating / cooling is also unnecessary, and a great cost advantage can be obtained.
[0037]
A laminar flow is required to flow the emulsified reaction solution into the inside of the tubular reactor and maintain the emulsified state. That is, it is necessary that the Re number, which is a dimensionless number representing the flow state of the reaction solution, be a laminar flow of 2000 or less. Although the Re number is often described in written books and is a well-known index, it is expressed by the following equation.
Re number = ρud / μ
Here, ρ [kg / m3]: fluid density
u [m / s]: Fluid representative velocity
d [m]: representative length (diameter of pipe)
μ [Pa · s]: Fluid viscosity
[0038]
In the case of a turbulent flow having a Re number of 4000 or more, the turbulence of the flow is severe, and the droplets of the dispersed aqueous phase collide with each other, causing the droplets to break up and increase in size. It becomes emulsified.
[0039]
In the case of a transition flow of 2000 <Re number <4000, the degree of turbulence of the flow is weaker than that of the turbulent flow, but is not preferable.
[0040]
The Re number needs to be 2000 or less, but the preferred range of the Re number is 1000 or less, and the more preferred range is 500 or less. The Re number is preferably 1 or more from the viewpoint of fluidity.
[0041]
In the method of the present invention, a condensation polymerization catalyst is used to increase the reaction rate. As the polycondensation catalyst to be added, tertiary amines such as triethylamine, tri-n-propylamine and tri-n-butylamine, and quaternary amines such as trimethylbenzylammonium chloride can be used alone or in combination. Most preferred is triethylamine, which is available and has excellent catalytic effects. The amount of the polycondensation catalyst to be used is preferably 0.002 to 2.0 mol%, more preferably 0.05 to 0.5 mol%, based on the number of moles of the dihydric phenol used. When the amount of the catalyst is less than 0.002 mol%, the catalytic effect is hardly exhibited, and the reaction time cannot be shortened. When the amount of the catalyst is more than 2.0 mol%, the decomposition of the chloroformate group and the carbonate bond tends to occur. In addition, much labor is required to remove and recover the polycondensation catalyst in the washing step.
[0042]
The equipment and method for addition of the condensation polymerization catalyst are as follows: a method of installing a pipe nozzle in the middle of the tubular reactor and press-fitting the catalyst (see FIG. 5), or a method of installing a pot in the middle of the tubular reactor. Various methods can be selected, such as a method of adding a catalyst together with the reaction solution into the pot (see FIG. 6). Although the catalyst can be used as it is or as a solution diluted with a solvent, a methylene chloride solution which is easily diffused into the organic phase of the reaction solution is most preferable.
[0043]
After the reaction solution is highly emulsified by the emulsification equipment, the addition position of the condensation polymerization catalyst is set at 3 minutes of the total volume of the tubular reactor from the inlet of the tubular reactor which is a reactor for performing the condensation polymerization reaction. It is necessary to add a catalyst to the emulsified liquid up to the position of the volume of 2 above, and the position should be between 1/10 and 6/10 of the total volume of the tubular reactor on the inlet side. It is more preferable that the position be between 1/4 and 1/2 the total volume of the tubular reactor on the inlet side.
[0044]
Adding the catalyst to the reaction mixture before the inlet of the tubular reactor, that is, before the emulsification equipment, means that the polymerization reaction rapidly proceeds at the same time as the high emulsification in the emulsification equipment, and the separated water is generated, resulting in a non-emulsified state. The terminal chloroformate group is likely to remain in the polycarbonate resin after the reaction, and the amount of terminal OH groups of the polycarbonate resin increases due to an increase in the side reaction between the alkali and the chloroformate.
[0045]
Further, adding a catalyst to the emulsion at a position behind the two-thirds volume of the total volume of the tubular reactor makes it difficult to complete the reaction in a predetermined time, and is also obtained. The amount of residual chloroformate groups in the polycarbonate resin is undesirably increased.
[0046]
The reaction time of the polycondensation reaction of the present invention varies depending on reaction conditions such as the molar ratio of raw materials used, the reaction temperature, the degree of emulsification, and the amount of catalyst used, but is generally from 5 minutes to 30 minutes, preferably from 10 minutes to 10 minutes. 20 minutes.
[0047]
The apparatus for producing an aromatic polycarbonate in the present invention is a facility for mixing a molecular weight regulator and an aqueous alkali solution with a carbonate oligomer reaction liquid obtained by previously reacting an aqueous alkali solution of dihydric phenol and phosgene in the presence of an organic solvent. And an emulsifying equipment for making the mixed reaction liquid into a highly emulsified state, and further a tubular reactor with a heat insulating material provided with a catalyst addition / mixing tool in the middle of the equipment, and a continuous polycarbonate production apparatus characterized by the following: FIG. 2 shows an example of this concept.
[0048]
The present invention also includes the following apparatus comprising a plurality of parallel tubular reactors. That is, for one equipment for mixing a molecular weight regulator and an aqueous alkali solution into the oligomer reaction liquid, one or more emulsification equipment and one or more tubular reactors (including catalyst addition and mixing tools) are provided. This is a continuous polycarbonate production apparatus. Here, the number of emulsification equipment and the number of tubular reactors is 2 to 16, preferably 2 to 8. FIG. 4 shows an example of this concept.
[0049]
Furthermore, in the present invention, in order to maintain the polycondensation reaction temperature at a target value, the tubular reactor is provided with a heat insulating material or the like having a reliable heat insulating effect instead of the external cooling equipment and / or the external heating equipment. It is necessary to be. However, in this case, if there is a heat-retaining effect, there may be a situation in which there is no direct influence of the outside air, such as a closed room that blocks outside air, regardless of the heat-insulating material.
[0050]
【Example】
Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto unless it exceeds the scope of the gist.
(Test and analysis method)
(A) Measurement of average droplet diameter of dispersed aqueous phase of emulsion
The emulsion was placed on a slide glass and photographed using a Keyence Corporation digital HD microscope VH-7000 to determine the average droplet diameter of the dispersed aqueous phase.
[0051]
(B) Measurement of viscosity of reaction emulsion and calculation of Re number
The emulsified reaction liquid in the tubular reactor was led to a viscometer through a sampling pipe, the viscosity was measured, and the Re number was determined from the above-mentioned relational expression (Re number = ρud / μ). As a viscometer, a FVM-80A vibration type viscometer manufactured by Yamaichi Electric Co., Ltd. was used.
The Re number of the liquid in the static mixer is described in Hi-Mixer technical data (catalog) of Toray Engineering Co., Ltd., and was calculated from the following relational expression. (Re number = 277 pud / μ). Here the terms are the same as above. The relationship between the Re number and the flow state experimentally defined in Hi-Mixer is as follows. Laminar flow area: Re number <80, transition area: 80 <Re number <800, turbulent flow area: 800 <Re number
[0052]
(C) Bisphenol A concentration in the aqueous phase of the reaction solution
The reaction solution at the end of the polymerization reaction is sampled, the same amount of methylene chloride is added to the reaction solution, and the mixture is centrifuged to take out the aqueous phase. A certain amount of this aqueous phase was diluted with a dilute alkaline aqueous solution, and the absorbance at a wavelength of 294 nm and 330 nm was measured with a UV spectrophotometer (U-3000 manufactured by Hitachi, Ltd.), and the bisphenol A concentration was determined from the following equation.
Bisphenol A concentration (g / L) = (A₁-A₀) × n × 1/22
However, here A₁, A₀Is the absorbance at 294 nm and 330 nm, respectively, and n is the dilution factor.
[0053]
(D) Relative viscosity of oligomer
The reaction solution at the end of the phosgenation reaction was sampled, the organic phase was separated and purified, the solvent was evaporated from the organic phase, and the organic phase was dried under reduced pressure to obtain a carbonate oligomer. 0.700 g of the oligomer is dissolved in 100 ml of methylene chloride and measured at 20 ° C. using an Ostwald viscometer. The relative viscosity of the oligomer was determined by the following equation.
Oligomer relative viscosity η_rel= T₁/ T₀
Where t₁, T₀Is the measurement seconds for the solution and the solvent, respectively.
[0054]
(E) Viscosity average molecular weight (Mv) of polycarbonate
0.700 g of polycarbonate was dissolved in 100 ml of methylene chloride and measured at 20 ° C. with an Ostwald viscometer to determine the specific viscosity (η)._sp) Was calculated and inserted into the following equation.
η_sp/C=[η]+0.45×[η]²c
[Η] = 1.23 × 10^-4× (Mv)^0.83
Here, [η] is the intrinsic viscosity, η_sp= Η_rel−1, c = 0.7.
[0055]
(F) Amount of terminal chlorine (amount of chlorine derived from polycarbonate terminal chloroformate group) About 1 g of the sample polycarbonate was precisely weighed in a 20 ml volumetric flask, and dissolved by adding methylene chloride, and 4- (p-nitrobenzyl) pyridine was added thereto. Was added to 2 ml of a 0.50 g / L methylene chloride solution to adjust the color to 20 ml, and the absorbance at a wavelength of 440 nm was measured using a spectrophotometer (U-3000, manufactured by Hitachi, Ltd.). Separately, the amount of terminal chlorine in the sample was determined using a calibration curve prepared using phenyl chlorocarbonate. The lower limit of quantification was 0.1 ppm in terms of the amount of chlorine in the sample.
Terminal chlorine is a factor of deterioration of heat resistance, and is preferably 0.3 ppm or less.
[0056]
(G) Terminal OH group content (polycarbonate terminal OH group content)
28 mg of a sample polycarbonate was dissolved in 0.5 ml of deuterated chloroform, and the solution was measured using a nuclear magnetic resonance spectrometer (UNITY 300 (300 MHz) manufactured by Varian).¹H-NMR was measured to determine the OH value (eq / ton).
The terminal OH group is a factor of deterioration of dry heat resistance, and is preferably 3.0 eq / t or less.
[0057]
(H) Residual burning of molding
The dried polycarbonate pellets were held at 340 ° C. for 45 seconds in a plasticizing cylinder using an injection molding machine (J85ELII manufactured by Japan Steel Works, Ltd.) to form a 50 mm square sample plate having a thickness of 2 mm. Next, the sample plate was kept at 340 ° C. for 10 minutes in a plasticizing cylinder to form a sample plate. The hue (L value, a value, b value) of the sample plate was measured with a C light source using a color difference meter (color difference meter Z-1001DP type, Nippon Denshoku Co., Ltd.). ΔE (the following formula) was obtained from the difference (ΔL value, Δa value, Δb value) between the hues of the sample plate before and after the stay, and the burning after forming was evaluated.
ΔE = [(ΔL)²+ (Δa)²+ (Δb)²]^1/2
ΔE is preferably 0.2 or less.
[0058]
(I) Dry heat test
The sample plate before staying in (H) was treated with a hot air drier at 150 ° C. for 20 days, and the color difference meter was used to measure the yellowness YI of the sample plate. The difference in yellowness ΔYI before and after the heat treatment was determined, and the dry heat resistance was evaluated.
ΔYI is preferably 2.0 or less.
[0059]
[Reference Example 1] (Production of carbonate oligomer)
1500 kg of bisphenol A and 3 kg of hydrosulfite were dissolved in 8070 kg of a 7.2% by weight aqueous solution of caustic soda at 30 ° C. to prepare a 170 g / L aqueous solution of bisphenol A caustic soda. Fig. 1 shows the flow of the carbonate oligomer production and the main equipment. That is, 530 L / hr of an aqueous solution of bisphenol A caustic soda, 220 L / hr of methylene chloride and 43 kg / hr of phosgene were continuously charged into a first reactor (1) having an actual capacity of 15 L equipped with a cooling jacket and a stirrer. The reaction is carried out. The reaction solution in the second reactor (2) with a stirrer having an actual volume of 100 L is pumped at a flow rate of about 5000 L / hr, passed through the heat exchanger (4), cooled, and returned to the second reactor (via the pipe 11). ) Of which, about 1/10 volume of about 500 L / hr is sent to the first reactor (via the pipe 7), mixed with the raw material liquid and subjected to the phosgenation reaction. The reaction solution that overflows the first reactor flows into the second reactor, completes the phosgenation reaction at a liquid temperature of 20 ° C. in the second reactor, generates carbonate oligomers, and overflows the second reactor (pipe 6). via).
[0060]
The oligomer reaction solution discharged from the overflow outlet of the second reactor was sampled five times when it reached a steady state, and analyzed by the above-described method. The relative viscosity of the oligomer was 1.033 to 1.037. The terminal chlorine from the oligomer terminal chloroformate was 7.0 to 7.5%, the pH of the aqueous phase was 13 or more, and the concentration of bisphenol A was 26 to 27 g / L, all showing stable values.
[0061]
[Summary of facilities in Examples and Comparative Examples]
The flow and main equipment of the present invention are shown in FIG. 2 (note that numbers in () represent symbols on the drawing), but a receiving container (21), a pump (22), an emulsifier (23), a tube-type polymerization reactor equipped with a heat insulating material (24) (tube inner diameter 55 mmφ, tube length 50 m), condensation polymerization catalyst adding device (27) (tube length 10%, 50% of the total length of the tube-type polymerization reactor 50 m) %, 65%, 80%, where the tube length% corresponds to the tube volume%), and a methylene chloride diluent injection section (31) (decrease the concentration of the polymer solution after the reaction is completed).
[0062]
On the other hand, the flow and main equipment of the comparative example are shown in FIG. 3, but the tube type polymerization reaction device (24) (tube) provided with a receiving vessel (21), a pump (22), an emulsifier (23), and a heat insulating material. Inner diameter 55 mmφ, pipe length 50 m), static mixer (25) (Toray Hi-Mixer Nominal diameter 50 mm, number of elements 5 / set, 10 sets are installed at approximately equal intervals in the total length 50 m of the tubular polymerization reactor), shrinkage Polymerization catalyst addition device (27) (installed at positions of 10%, 50%, and 65% of the total length of 50 m of the tubular polymerization reactor, where the tube length% corresponds to the tube volume%), methylene chloride diluent injection section (31).
[0063]
That is, the difference between the two is that the comparative example has a plurality of static mixers (25) for the purpose of a stirring function (hereinafter, the static mixer may be abbreviated as SM), but the present invention excludes all the static mixers. It is a tubular polymerization reactor without a stirring function.
[0064]
Further, the flow and main equipment of the present invention having a plurality of emulsifiers and a plurality of tubular polymerization reactors are shown in FIG. 4, but include a receiving vessel (21), a pump (22), and two emulsifiers (23). , A tube-type polymerization reactor (24) with a heat insulating material (tube diameter 55 mmφ, tube length 50 m), a catalyst addition device (27) (installed at 50% of the total length of the tube-type polymerization reactor 50 m) 2 And a methylene chloride diluent injection section (31) (to decrease the concentration of the polymer solution after the reaction is completed).
[0065]
[Example 1]
It is an example of continuous non-stirred tube type polymerization of the present invention, and the apparatus shown in FIG. 2 was used. In a receiving container (21), 375 L / hr of a carbonate oligomer reaction solution produced by the phosgenation reaction in Reference Example 1 (via a pipe 15), 6.0 L / hr of a solution of a molecular weight regulator p-tert-butylphenol in methylene chloride (11 wt%). (Piping 16) and 5.2 L / hr of 48% aqueous sodium hydroxide solution (Piping 17) were continuously charged, and the mixture was sent by a pump (22), and two sets of static liquids were used as an emulsifier (23). Using a mixer (Toray Hi-Mixer Nominal diameter: 10 mm, number of elements: 5 / set) (23-1), a highly emulsified state of water-in-oil type is obtained (at this time, dispersion of the emulsion at the emulsifier outlet) The average droplet size of the aqueous phase was 15 μm, and the relative viscosity η of the oligomer in the liquid was η._relWas 1.095. ) Then, the emulsion was passed through a tubular polymerization reactor (24) having an inner diameter of 55 mm, flowed in a laminar flow over a total length of 50 m, and at a catalyst addition position B (27B) (50% capacity) on the way. 6.0 L / hr of a methylene chloride solution (1.0 vol%) of triethylamine as a condensation polymerization catalyst was continuously added, and a condensation polymerization reaction was carried out at an ultimate reaction temperature of 30 ± 1 ° C. The required polymerization reaction time was 20 minutes. The emulsified state was maintained until the reaction was completed, and a small amount of water was separated from the emulsion. On the way, the reaction liquid was sampled from the sampling nozzles (30-1 and 30-2) and the viscosity was measured. The viscosity of the reaction emulsion at the forefront of the reaction tube was 0.05 Pa · s, and the Re number was 70. Further, the viscosity was 0.40 Pa · s and the Re number was 8.6 in the middle part (60% point) of the reaction tube. In both cases, the laminar flow range could be confirmed with Re number <2000. The concentration of bisphenol A in the aqueous phase of the reaction solution at the end of the reaction was 0.11 g / L (corresponding to a reaction yield of 99.94%). At the end of the reaction, 236 L / hr of methylene chloride was continuously poured into the reaction solution to adjust the polycarbonate concentration in the methylene chloride layer to 10% by weight.
[0066]
Next, the diluted mixture is passed through a filtration layer to separate and remove an aqueous layer, and then subjected to washing once, hydrochloric acid treatment once, and washing twice to remove salts, alkalis, catalysts, and the like. Got. Next, this polycarbonate solution was charged into a kneader containing warm water at 50 ° C., the solvent was removed to produce a polycarbonate powder and granules. did. The average molecular weight, terminal chlorine amount (chlorine derived from a chloroformate group), and terminal OH group amount of this pellet were measured, and the results are shown in Table 1.
[0067]
Next, the pellet was held at 340 ° C. for 45 seconds in a plasticizing cylinder using an injection molding machine (J85ELII manufactured by Japan Steel Works, Ltd.) to form a sample plate having a thickness of 2 mm and a square of 50 mm. Further, the sample was kept at 340 ° C. for 10 minutes in a plasticizing cylinder to form a sample plate. The molding retention burn was evaluated from the difference (ΔE) in the hue of the sample plate before and after the retention. Furthermore, the sample plate before staying was subjected to dry heat treatment at 150 ° C. for 20 days, and the dry heat resistance was evaluated from the difference in yellowness (ΔYI) before and after the treatment. The results are shown in Table 1.
[0068]
In Example 1, the reaction yield was good, the terminal chlorine content and the terminal OH group content were both low, and the molding retention burning and dry heat resistance were excellent.
[0069]
[Comparative Example 1]
The apparatus shown in FIG. 3 was used. In a receiving container (21), a carbonate oligomer reaction solution (via 15) formed by the phosgenation reaction in Reference Example 1, a methylene chloride (11 wt%) solution of a molecular weight modifier p-tert-butylphenol (via 16), and 48% caustic soda The same amount as in Example 1 was continuously charged for each of the aqueous solutions (via 17), and the mixed solution was fed by a pump (22), and two sets of static mixers (23-1) (23-1) were used as emulsifiers (23). Using a Toray Hi-Mixer (nominal diameter 10 mm, number of elements 5 / set), a water-in-oil type highly emulsified state (in this case, the average droplet size of the dispersed aqueous phase of the emulsion at the outlet of the emulsifier) Was 15 μm, and the relative viscosity η of the oligomer in the same liquid was η._relWas 1.094. ) Then, the emulsion was passed through a tubular polymerization reactor (24), stirred by 10 sets of SMs (static mixers) (25) installed in a total length of 50 m, and further added a catalyst addition position B ( 27B) (at a 50% capacity point), 6.0 L / hr of a methylene chloride solution of catalyst triethylamine (1.0 vol%) was continuously added, and a polymerization reaction was carried out at an ultimate reaction temperature of 30 ± 1 ° C. The required polymerization reaction time was 20 minutes. When viewed with a peeper (not shown), a large amount of water was separated from the emulsion at the rear of the sixth set of SMs from the front (the rear of the first set of SMs behind the catalyst addition section). The measured viscosity of the reaction emulsion at the forefront of the reaction tube was 0.05 Pa · s, and the Re number was 70. In the middle part of the reaction tube (60% point), the measured viscosity varied from 0.25 to 0.45 Pa · s, and the Re number was from 11.4 to 6.9. The fluctuation was influenced by the separated water. Both were in the laminar flow range with Re number <2000. On the other hand, the Re number of the reaction solution inside the SM at a position adjacent to both of them was a value in the turbulent flow region of 18000 and 2600. At the end of the reaction, the bisphenol A concentration in the aqueous phase of the reaction solution was measured and found to be 0.31 g / L (corresponding to a reaction yield of 99.84%). At the end of the reaction, 236 L / hr of methylene chloride was continuously poured into the reaction solution (via 31) to adjust the polycarbonate concentration in the methylene chloride phase to 10 wt%.
[0070]
Subsequent operations of purification, granulation, drying and extrusion were performed in the same manner as in Example 1 to obtain pellets. The quality of the pellets was measured, and the results are shown in Table 1. In addition, an injection molding retention burn test and a dry heat test were performed in the same manner as in Example 1. The results are shown in Table 1.
[0071]
The sample of Comparative Example 1 had a larger amount of terminal chlorine and a larger amount of terminal OH groups than Example 1, and was inferior in molding retention burn and dry heat resistance. This is because the emulsification was weakened by the stirring effect of SM, and the polycondensation reaction was slow and incomplete.
[0072]
[Example 2]
Example 1 was carried out under the same conditions except that the catalyst addition position was changed from point B to point A (27A) (10% capacity point). The emulsified state was maintained until the reaction was completed, and a small amount of water was separated from the emulsion.
[0073]
The operations of purification, granulation, drying, and extrusion, measurement of the quality of pellets, injection molding retention burn test, and dry heat test were also performed in the same manner as in Example 1. The results are shown in Table 1.
[0074]
In Example 2, as in Example 1, the reaction yield was good, the amount of terminal chlorine and the amount of terminal OH groups were both low, and the molding retention burning and dry heat resistance were excellent.
[0075]
[Comparative Example 2]
In Comparative Example 1, all the operations were performed under the same conditions except that the catalyst addition position was changed from point B to point A (27A) (capacity 10% point). When viewed with a peeper, a large amount of water was separated from the emulsion at the rear of the third SM from the front (the rear of the second SM after the catalyst addition section).
[0076]
Purification, granulation, drying and extrusion operations, pellet quality measurement, injection molding retention burn test and dry heat test were also conducted in the same manner as in Comparative Example 1. The results are shown in Table 1.
[0077]
The sample of Comparative Example 2 had a larger amount of terminal chlorine and terminal OH group than Example 2, and was inferior in molding retention burn and dry heat resistance. This is because the emulsification was weakened by the stirring effect of SM, and the polycondensation reaction was slow and incomplete.
[0078]
[Example 3]
Example 1 was carried out under the same conditions except that the catalyst addition position was changed from point B to point C (27C) (capacity 65% point). The emulsified state was maintained until the end of the reaction, and a small amount of water was separated from the emulsion.
[0079]
The operations of purification, granulation, drying, and extrusion, measurement of the quality of pellets, injection molding retention burn test, and dry heat test were also performed in the same manner as in Example 1. The results are shown in Table 1.
[0080]
In Example 3, as in Example 1, the reaction yield was good, the amount of terminal chlorine and the amount of terminal OH groups were both low, and the molding retention burning and drying heat resistance were excellent.
[0081]
[Comparative Example 3]
In Comparative Example 1, the same operation was performed except that the catalyst addition position was changed from point B to point C (27C) (capacity 65% point). When viewed with a peeper, a large amount of water was separated from the emulsion at the rear of the eighth set of SMs from the front (the rear of the first set of SMs behind the catalyst addition section).
[0082]
Purification, granulation, drying and extrusion operations, pellet quality measurement, injection molding retention burn test and dry heat test were also conducted in the same manner as in Comparative Example 1. The results are shown in Table 1.
[0083]
The sample of Comparative Example 3 was larger in terminal chlorine content and terminal OH group content than in Example 3, and was inferior in molding retention burn and dry heat resistance. This is because the emulsification was weakened by the stirring effect of SM, and the polycondensation reaction was slow and incomplete.
[0084]
[Comparative Example 4]
In Example 1 (using the apparatus shown in Fig. 2), the same conditions were used except that the catalyst addition position was changed from point B to point D (27D) (80% capacity point). The emulsified state was maintained until the end of the reaction, and a small amount of water was separated from the emulsion.
[0085]
The operations of purification, granulation, drying, and extrusion, measurement of the quality of pellets, injection molding retention burn test, and dry heat test were also performed in the same manner as in Example 1. The results are shown in Table 1.
[0086]
The sample of Comparative Example 4 had a large amount of terminal chlorine, and was inferior in molding retention burn. The reaction was not completed because the catalyst addition time was too late.
[0087]
[Comparative Example 5]
In Example 1 (using the apparatus shown in FIG. 2), all the operations were performed under the same conditions except that the catalyst addition position was changed from the point B to the receiving container (21) and the catalyst was added via the pipe 16. The average droplet size of the dispersed aqueous phase of the emulsion at the outlet of the emulsifier could not be measured due to generation of separated water. At the end of the reaction, a large amount of water had separated.
[0088]
Purification, granulation, drying, and extrusion operations, pellet quality measurement, injection molding retention burn test, and dry heat test were also performed in the same manner as in Example 1. The results are shown in Table 1.
[0089]
The sample of Comparative Example 5 had a large amount of terminal chlorine and a large amount of terminal OH groups, and was inferior in stagnation burning and dry heat resistance. This is because, since the catalyst was added before the emulsifier, the emulsion at the outlet of the emulsifier had separated water, and the polycondensation reaction was performed in a state where the separated water was large, and the reaction was slow and uncompleted.
[0090]
[Comparative Example 6]
In Comparative Example 1 (using the apparatus shown in FIG. 3), the procedure was carried out under the same conditions except that the catalyst addition position was changed from the point B to the receiving vessel (21) and the catalyst was added via the pipe 16. The average droplet size of the dispersed aqueous phase of the emulsion at the outlet of the emulsifier could not be measured due to generation of separated water. At the end of the reaction, a large amount of water had separated.
[0091]
Purification, granulation, drying and extrusion operations, pellet quality measurement, injection molding retention burn test and dry heat test were also conducted in the same manner as in Comparative Example 1. The results are shown in Table 1.
[0092]
The sample of Comparative Example 6 had a large amount of terminal chlorine and a large amount of terminal OH groups, and was inferior in molding retention burning and dry heat resistance. This is because, since the catalyst was added before the emulsifier, the emulsion at the outlet of the emulsifier had separated water, and the polycondensation reaction was performed in a state where the separated water was large, and the reaction was slow and uncompleted.
[0093]
[Example 4]
This is an example of a continuous reaction apparatus having a plurality of emulsifiers and a plurality of tubular polymerization reactors of the present invention, and used the apparatus shown in FIG. In the receiving container (21), 750 L / hr of a carbonate oligomer reaction liquid produced by the phosgenation reaction in Reference Example 1 (via a pipe 15), 12.0 L / hr of a solution of a molecular weight regulator p-tert-butylphenol in methylene chloride (11 wt%) (Via pipe 16) and 10.4 L / hr of a 48% aqueous sodium hydroxide solution (via pipe 17) were continuously charged, and the mixed solution was fed by a pump (22). Flow into the flow path (a), and use two sets of static mixers (Toray Hi-Mixer Nominal diameter 10 mm, number of elements 5 / one set) (23-1) as an emulsifier (23a) (23-1) (At this time, the average droplet size of the aqueous phase dispersed in the emulsion at the outlet of the emulsifier was 15 μm; the results are shown in Table 1). The mixture was passed through a tubular polymerization reactor (24), flowd in a laminar flow over a total length of 50 m, and at a catalyst addition position B (27B) (50% capacity) on the way, a methylene chloride solution (1.0 vol. ) 6.0 L / hr was added continuously, and the polymerization reaction was carried out at a reached reaction temperature of 30 ± 1 ° C. The remaining amount of the pump outlet (1/2 of the total amount) was passed through the other flow path (b), and a polymerization reaction was carried out in the same manner as the flow path (a) (the average droplet size at the emulsifier outlet was 16 μm. there were). In both cases, the emulsified state was maintained until the reaction was completed, and a small amount of water was separated from the emulsion. At the end of the polymerization reaction, 472 L / hr of methylene chloride was continuously added to the reaction mixture of the two to adjust the polycarbonate concentration in the methylene chloride layer to 10% by weight.
[0094]
The operations of purification, granulation, drying, and extrusion, measurement of the quality of pellets, injection molding retention burn test, and dry heat test were also performed in the same manner as in Example 1. The results are shown in Table 1.
[0095]
In Example 4, as in Example 1, the reaction yield was good, the amount of terminal chlorine and the amount of terminal OH groups were low, and the molding retention burning and dry heat resistance were excellent.
[0096]
[Example 5]
In Example 1, a homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd., TK.) Was used instead of two sets of static mixers (Toray Hi-Mixer, nominal diameter 10 mm, number of elements: 5 / set) as emulsifiers. Using a homomic line flow 500 type, the turbine blade was operated at a rotation speed of 3600 rpm to obtain a water-in-oil type highly emulsified state (at this time, the average droplet size of the dispersed aqueous phase of the emulsion at the outlet of the emulsifier). Was 16 μm, and the relative viscosity η of the oligomer in the liquid was η._relWas 1.097). Except for that, the procedure was performed under the same conditions. The emulsified state was maintained until the reaction was completed, and a small amount of water was separated from the emulsion. On the way, the reaction liquid was sampled from the sampling nozzles (30-1 and 30-2) and the viscosity was measured. The viscosity of the reaction emulsion at the forefront of the reaction tube was 0.05 Pa · s, and the Re number was 70. The viscosity was 0.41 Pa · s and the Re number was 8.4 in the middle part of the reaction tube (60% point). In both cases, the laminar flow range could be confirmed with Re number <2000.
[0097]
The operations of purification, granulation, drying, and extrusion, measurement of the quality of pellets, injection molding retention burn test, and dry heat test were also performed in the same manner as in Example 1. The results are shown in Table 1.
[0098]
In Example 5, as in Example 1, the reaction yield was good, the amount of terminal chlorine and the amount of terminal OH groups were low, and the molding retention burning and dry heat resistance were excellent.
[0099]
[Example 6]
In Example 5, a homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd., TK homomic line flow 500 type) was used as an emulsifier at a turbine blade rotation speed of 2700 rpm, and a water-in-oil type was used. The emulsion was in a highly emulsified state (at this time, the average droplet size of the aqueous phase dispersed in the emulsion at the outlet of the emulsifier was 31 μm). Except for that, the procedure was performed under the same conditions. The emulsified state was maintained until the reaction was completed, and a small amount of water was separated from the emulsion.
[0100]
The operations of purification, granulation, drying, and extrusion, measurement of the quality of pellets, injection molding retention burn test, and dry heat test were also performed in the same manner as in Example 1. The results are shown in Table 1.
[0101]
In Example 6, as in Example 1, the reaction yield was good, the amount of terminal chlorine and the amount of terminal OH groups were low, and the molding retention burn and dry heat resistance were excellent.
[0102]
[Comparative Example 7]
In the apparatus of FIG. 3 used in Comparative Example 1, a tubular polymerization reactor having an inner diameter of 55 mm and a length of 50 m was further connected to a tubular polymerization reactor having the same diameter of 25 m including five sets of static mixers, The experiment was carried out under the same conditions as in Comparative Example 1 except for a tubular polymerization reactor having a total length of 75 m. The catalyst was added at the point B, and the required reaction time was 30 minutes. At the rear part of the sixth set of SMs from the front (the rear part of the first set of SMs behind the catalyst addition section), a large amount of water was separated from the emulsion. The concentration of bisphenol A in the aqueous phase of the reaction solution at the end of the reaction was 0.28 g / L (corresponding to a reaction yield of 99.86%), which was inferior to Example 1. At the end of the reaction, 236 L / hr of methylene chloride was continuously poured into the reaction solution to adjust the concentration of polycarbonate in the methylene chloride phase to 10% by weight.
[0103]
Purification, granulation, drying and extrusion operations, pellet quality measurement, injection molding retention burn test and dry heat test were also conducted in the same manner as in Comparative Example 1. The results are shown in Table 1.
[0104]
The sample of Comparative Example 7 had slightly higher terminal chlorine content and terminal OH group content than Example 1, and was inferior in molding retention burning and dry heat resistance. However, compared with Comparative Example 1, the terminal chlorine content and terminal OH group content were lower. Both of them decreased and the resistance to burning and the heat during drying were improved. The polycondensation reaction slowed down due to the weakening of emulsification and the generation of separated water due to the stirring action of the SM, but the reaction time was extended from 20 minutes to 30 minutes, and the reaction was almost completed, resulting in a considerable improvement in quality. Was. However, it has a disadvantage that the reaction requires a longer time than in Example 1.
[0105]
[Comparative Example 8]
A homomixer was used as an emulsifier, a condensation polymerization reactor was used instead of a tubular condensation polymerization reactor, and no catalyst was used, and non-stirring static polymerization was performed. That is, the composition of the raw materials and the charging speed were the same as in Example 1, and the turbine was formed using a homomixer (TK homomic line flow 500, manufactured by Tokushu Kika Kogyo Co., Ltd.) in the same manner as in Example 5. The emulsifier was operated at a blade rotation speed of 3600 rpm to obtain a highly emulsified state of a water-in-oil type (at this time, the average droplet size of the dispersed aqueous phase of the emulsion at the outlet of the emulsifier was 15 μm). 70 L of the emulsified liquid was charged into a 100-liter polymerization reaction tank, and the polycondensation reaction was carried out for 2 hours while keeping the temperature of 30 ± 1 ° C. without a catalyst and stirring without stirring to complete the reaction. At the end of the reaction, the bisphenol A concentration in the aqueous phase of the reaction solution was measured and found to be 1.2 g / L (corresponding to a reaction yield of 99.4%). After adding methylene chloride to the solution to adjust the polycarbonate concentration to 10% by weight, purification, granulation, drying and extrusion operations, pellet quality measurement, injection molding retention burn test and dry heat test were also conducted in the same manner as in Example 1. The results are shown in Table 1.
[0106]
As a result of Comparative Example 8, the amount of bisphenol A in the aqueous phase at the end of the reaction was large (the reaction yield was poor), the amount of polymer terminal OH groups in the sample was large, and the dry heat resistance was poor. In addition, a long reaction time was required and productivity was poor.
[0107]
[Table 1]

[0108]
【The invention's effect】
Conventionally, the polycondensation reaction of polycarbonate has been carried out using a stirrer such as a multistage reaction tank with a stirrer, or a tubular reactor equipped with a static mixer, an orifice mixer, etc. According to the simple equipment / method which uses a tubular reactor without a stirring function and eliminates such a stirrer and in which the emulsified reaction solution is flowed in a laminar flow and only a catalyst is added, a very short time is required. The polycondensation reaction can be completed in a short period of time, and the reaction yield is excellent, and the amount of residual chloroformate groups and terminal OH groups in the polymer is small as the quality of the obtained polycarbonate. It is possible to easily produce a polycarbonate excellent in heat resistance with little dry heat coloring of a molded article and at a low equipment cost, and the industrial value of the present invention is extremely large.
[Brief description of the drawings]
FIG. 1 is a view showing an apparatus for producing a carbonate oligomer.
FIG. 2 is a view showing a polycarbonate continuous polycondensation reaction apparatus of the present invention (and a part of Comparative Example).
FIG. 3 is a view showing a polycarbonate continuous polycondensation reaction apparatus of a comparative example.
FIG. 4 is a view showing a continuous polycondensation reaction apparatus for polycarbonate of the present invention (Example 4).
FIG. 5 is a diagram showing an example of the emulsifier and catalyst addition equipment of the present invention.
FIG. 6 is a diagram showing an example of the emulsifier and catalyst addition equipment of the present invention.
[Explanation of symbols]
1. First reactor (Fig. 1)
2. Second reactor
3. Circulation pump
4. Heat exchanger
5. Overflow piping (first reactor)
6. Overflow piping (second reactor)
7. Partial circulation piping
8.配 管 Piping for bisphenol A caustic soda aqueous solution
9. Phosgene charging pipe
10.メ チ レ ン Methylene chloride injection piping
11. Circulation piping
15. Carbonate oligomer reaction solution injection pipe (Fig. 2, Fig. 3, Fig. 4)
16. Injection piping for molecular weight regulator
17. Caustic soda aqueous solution input piping
21. Receiving container
22. Feed pump
23. Emulsifying machine
23a. Emulsifier for channel a (Figure 4)
23b. Emulsifier for channel b (Figure 4)
23-1. Static mixer (emulsifier) (Figure 5)
23-2. Homo mixer (emulsifier) (Fig.-6)
24. Tubular condensation polymerization reactor (with heat insulation material)
25. Static mixer (for stirring and mixing the reaction solution) (Figure 3)
26a. Reaction liquid channel a (Fig. 4)
26b. Reaction solution channel b (Figure 4)
27A. Point A catalyst addition device (tube capacity 10% point)
27B. B point catalyst addition device (tube capacity 50% point)
27C. C point catalyst addition equipment (pipe capacity 65% point)
27D. D point catalyst addition device (tube capacity 80% point)
27-1. Press-fit type catalyst addition device (Fig. 5)
27-2. Pot-type catalyst addition device (Fig. 6)
28-1. Catalyst addition pipe (Fig. 5)
28-2. Catalyst addition piping (Fig. 6)
28-P. Catalyst press-in pump (Fig. 5)
29. Reaction liquid pump (Fig. 6)
30-1. Sampling nozzle (installed at the forefront of the tubular reactor)
30-2. Sampling nozzle (installed at the middle of the tubular reactor, 60% from the front)
30-3. Sampling nozzle (the last part of the tube reactor: the end point of the polymerization reaction)
31. Methylene chloride injection piping for dilution

Claims (7)

After a carbonate oligomer reaction solution is formed by reacting an alkaline aqueous solution of a dihydric phenol with phosgene in the presence of an organic solvent, an interfacial polycondensation reaction is performed to continuously produce a polycarbonate resin. After the emulsified state of the middle water type, an interfacial polycondensation reaction is carried out while maintaining the emulsified state in a laminar flow using a tubular reactor, and the entirety of the tubular reactor is introduced through the inlet of the tubular reactor. A continuous production method of a polycarbonate resin, wherein a condensation polymerization catalyst is added to a position of two thirds of the volume. The polycarbonate resin according to claim 1, wherein after the addition of a molecular weight regulator and / or an aqueous alkali solution to the formed carbonate oligomer reaction solution, an interfacial polycondensation reaction is carried out using a tubular reactor in a water-in-oil type emulsified state. Continuous manufacturing method. The method for continuous production of a polycarbonate resin according to claim 1, wherein the average droplet size of the aqueous dispersion phase of the oligomer reaction liquid when the emulsion is in a water-in-oil type emulsion is 50 µm or less. The continuous production method of a polycarbonate resin according to claim 1, wherein the Re number of the emulsified reaction solution flowing in the tubular reactor is a laminar flow of 2000 or less. The temperature of the oligomer reaction solution is controlled, and in the subsequent interfacial polycondensation reaction, the target temperature is reached by the heat generated by the reaction and the heat generated by the power energy of the liquid feed pump and the emulsifier. The method for continuously producing a polycarbonate resin according to claim 1, wherein the condensation polymerization reaction temperature is maintained in a predetermined range only by keeping the temperature without forcibly cooling and / or heating from the outside. Equipment for mixing a molecular weight regulator and an aqueous alkali solution with an oligomer reaction liquid, an emulsification equipment for converting the reaction liquid into a highly emulsified state, and a tubular reactor with a heat insulating material equipped with a catalyst addition and mixing tool in the middle of the equipment A continuous production apparatus for a polycarbonate resin, comprising: 7. The polycarbonate resin according to claim 6, comprising one or more emulsifying equipment and one or more tubular reactors for one equipment for mixing the molecular weight regulator and the aqueous alkali solution into the oligomer reaction liquid. Continuous production equipment.

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