Aromatic polycarbonate, method for producing aromatic polycarbonate, and container

Abstract

This aromatic polycarbonate satisfies, when a test piece thereof having a size of 127 mm × 12.7 mm × 0.8 mm is elongated at a rate of 0.005 sec-1 at 280°C, conditions (i) and (ii) regarding an index of a change in elongation viscosity, and has a MFR of 1.5-4.5 (g / 10 min) at 300°C under a load of 1.2 kg. <Condition (i)> In an interval A (interval of 0.30-0.80 seconds after start of elongation), the index of the change in elongation viscosity represented by formula (1) (log10(elongation viscosity [Pa·s] at 0.80 seconds)-log10(elongation viscosity [Pa·s] at 0.30 seconds)) / (log100.80-log100.30) is 0.10-0.30. <Condition (ii)> In an interval B (interval of 3.0-8.0 seconds after start of elongation), the index of the change in elongation viscosity represented by formula (2) (log10( elongation viscosity [Pa·s] at 8.0 seconds)-log10( elongation viscosity [Pa·s] at 3.0 seconds)) / (log108.0-log103.0) is 0.70-1.1.

Description

[Technical Field]

[0001] The present invention relates to an aromatic polycarbonate, a method for producing an aromatic polycarbonate, and a container. [Background technology]

[0002] It has been known that aromatic polycarbonates used in large-scale blow molding, extrusion molding, profile extrusion molding, and hollow sheet molding require appropriate melt strength, melt elasticity, and melt viscosity. Regarding the production of such aromatic polycarbonates, techniques have been disclosed that improve their properties by using multifunctional compounds such as trifunctional or tetrafunctional hydroxy compounds (see, for example, Patent Documents 1 to 4). However, the aromatic polycarbonates disclosed in these publications all have the problem that there is room for further improvement in their properties.

[0003] Furthermore, a method has been proposed in which, when producing an aromatic polycarbonate by a transesterification method, a "Kolbe-Schmitt type reaction in which an aromatic polycarbonate having a branched structure is obtained as a side reaction product" or a "reaction via the production of isoalkenylphenol" is actively induced during the polymerization process to produce an aromatic polycarbonate having a desired branched structure (see, for example, Patent Document 5). However, these methods have the problem that the aromatic polycarbonate produced has poor color, many fish eyes, and low impact strength.

[0004] The present inventors have disclosed a technology for solving the above-mentioned problems of the conventional technology, which relates to an aromatic polycarbonate in which the branched structure resulting from side reactions and the branched structure resulting from polyfunctional compounds are controlled to a predetermined amount and range (see, for example, Patent Document 6). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 44-17149 [Patent Document 2] Japanese Patent Publication No. 51-129493 [Patent Document 3] Special Publication No. 2003-509551 [Patent Document 4] Japanese Patent Application Publication No. 8-239466 [Patent Document 5] Japanese Patent Application Laid-Open No. 2004-2831 [Patent Document 6] International Publication No. 2012 / 005250 Summary of the Invention [Problem to be solved by the invention]

[0006] However, even the aromatic polycarbonate disclosed in Patent Document 6 has problems such as insufficient impact resistance when a molded article becomes partially thin in large-scale blow molding or the like.

[0007] Therefore, an object of the present invention is to provide an aromatic polycarbonate having excellent moldability. [Means for solving the problem]

[0008] In view of the above-mentioned problems of the conventional art, the present inventors have conducted extensive research and have found that the above-mentioned problems can be solved by using an aromatic polycarbonate that satisfies a predetermined index of change in extensional viscosity, thereby completing the present invention. That is, the present invention is as follows.

[0009] [1] A test piece measuring 127 mm in length, 12.7 mm in width, and 0.8 mm in thickness was subjected to a temperature of 280°C and an elongation rate of 0.005 sec. -1 The index of change in extensional viscosity measured by satisfies the following <Condition (i)> to <Condition (ii)>, The MFR measured at a temperature of 300°C and a load of 1.2 kg is 1.5 to 4.5 (g / 10 min). Aromatic polycarbonate. <Condition (i)> An index of change in extensional viscosity in section A (the section from 0.30 seconds to 0.80 seconds after the start of extension) represented by the following formula (1): (log 10 (Extensional viscosity at 0.80 seconds [Pa s])-log 10 (Extensional viscosity at 0.30 seconds [Pa·s]) ÷(log 10 0.80-log 10 0.30) Equation (1) The value is 0.10 to 0.30. <Condition (ii)> An index of change in extensional viscosity in section B (the section from 3.0 seconds to 8.0 seconds after the start of extension) represented by the following formula (2): (log 10 (Extensional viscosity at 8.0 seconds [Pa s])-log 10 (Extensional viscosity at 3.0 seconds [Pa·s]) ÷(log 10 8.0-log 10 3.0) Equation (2) The value is 0.70 to 1.1. [2] The aromatic polycarbonate according to [1] above, further satisfying the following <condition (iii)> to <condition (iv)>: <Condition (iii)> An index of the increase in extensional viscosity in the section from 0.30 seconds to 8.0 seconds after the start of the extension, represented by the following formula (3): log 10 (Extensional viscosity at 8.0 seconds [Pa s])-log 10 (Extensional viscosity at 0.30 seconds [Pa·s]) Equation (3) The value is 0.45 to 0.90. <Condition (iv)> An index of extensional viscosity represented by the following formula (4) at 8.0 seconds after the start of the extension: log 10 (Extensional viscosity at 8.0 seconds [Pa·s]) Equation (4) The value is 4.90 to 5.40. [3] The aromatic polycarbonate according to [1] or [2] above, wherein the index value of the change in extensional viscosity represented by the formula (2) is 0.70 to 0.85. [4] The aromatic polycarbonate according to [2] or [3] above, wherein the index value of the increase in extensional viscosity represented by the formula (3) is 0.45 to 0.75. [5] The aromatic polycarbonate according to any one of [2] to [4] above, wherein the value of the extensional viscosity index represented by the formula (4) is 4.90 to 5.05. [6] The aromatic polycarbonate according to any one of [1] to [5] above, which has a repeating unit represented by the following general formula (5):

[0010] [ka]

[0011] In formula (5), Ar represents a divalent aromatic residue.

[0012] [7] The polymer has a repeating unit represented by the following general formula (5) in the main chain and in the branched chains: The main chain and branched chains contain one or more branched structures selected from the group consisting of branched structures represented by the following general formulas (6), (7), and (8): The aromatic polycarbonate according to any one of [1] to [6] above, wherein the ratio of the total amount of substances of the branched structures to the amount of substances of the repeating units represented by the following general formula (5) is 0.9 mol % to 5.0 mol %:

[0013] [ka]

[0014] In the formulae (5), (6), (7) and (8), Ar represents a divalent aromatic residue, and Ar' represents a trivalent aromatic residue.

[0015] [8] The polymer has a repeating unit represented by the following general formula (5) in the main chain and in the branched chains: The main chain and branched chains contain one or more branched structures selected from the group consisting of branched structures represented by the following general formulas (6), (7), and (8): the ratio of the total amount of substances of the branched structures to the amount of substances of the repeating unit represented by the following general formula (5) is 0.9 mol % to 5.0 mol %, The aromatic polycarbonate according to any one of [1] to [7] above, further satisfying the following <condition (iii)> to <condition (iv)>:

[0016] [ka]

[0017] In the formulae (5), (6), (7) and (8), Ar represents a divalent aromatic residue, and Ar' represents a trivalent aromatic residue.

[0018] <Condition (iii)> An index of the increase in extensional viscosity in the section from 0.30 seconds to 8.0 seconds after the start of the extension, represented by the following formula (3): log 10 (Extensional viscosity at 8.0 seconds [Pa s])-log 10 (Extensional viscosity at 0.30 seconds [Pa·s]) Equation (3) The value is 0.45 to 0.90. <Condition (iv)> An index of extensional viscosity represented by the following formula (4) at 8.0 seconds after the start of the extension: log 10 (Extensional viscosity at 8.0 seconds [Pa·s]) Equation (4) The value is 4.90 to 5.40.

[0019] [9] The aromatic polycarbonate according to [8] above, wherein the value of the extensional viscosity index represented by the formula (4) is 4.90 to 5.10.

[10] A method for producing the aromatic polycarbonate according to any one of [1] to [9] above, a step of supplying the nitrogen-absorbed aromatic polycarbonate prepolymer to a guided contact flow-down polymerization apparatus constituting an aromatic polycarbonate production apparatus; allowing the prepolymer to flow down along the outer surface of a guide that does not itself have a heating source to evaporate low boiling point substances; and In a process region in which the temperature of the polymerization raw materials is 235°C or higher in all processes of the method for producing an aromatic polycarbonate,

[0020]

number

[0021] i: Process area numbers assigned in any order to multiple process areas in the manufacturing method Ti: Average temperature of the polymerization raw material in the i-th process area (°C) Hi: Average residence time (hr) of the polymerization raw material in the i-th process zone The value K represented by is in the range of 16.5 to 25.0, A method for producing aromatic polycarbonate.

[0022]

[11] The evaporation of the low boiling point substance is carried out using a guided contact flow-down polymerization apparatus, The guide contact flow-down type polymerization apparatus satisfies the following <Condition (1)> to <Condition (9)>: The method for producing an aromatic polycarbonate according to

[10] above. <Condition (1)> The evaporation zone has a liquid receiving port, a liquid supply zone for supplying liquid to the guides in the evaporation zone through a perforated plate, an evaporation zone in which a plurality of guides extending downward from the perforated plate are provided in a space surrounded by the perforated plate, a side casing, and a bottom casing, a vacuum vent port provided in the evaporation zone, and a liquid discharge port provided at the bottom of the bottom casing. <Condition (2)> In the liquid supply zone, a flow path control component is installed which has the function of directing the liquid supplied from the liquid receiving port to the perforated plate from the periphery toward the center of the perforated plate. <Condition (3)> The internal cross-sectional area A (m 2 ) satisfies the following formula (I): 0.7≦A≦300 Formula (I) <Condition (4)> The internal cross-sectional area A (m 2 ) and the internal cross-sectional area B (m 2 ) satisfies the following formula (II): 20≦A / B≦1000 Formula (II) <Condition (5)> The bottom casing constituting the bottom of the evaporation zone is connected to the upper side casing at an angle C degrees within the bottom casing, and the angle C (°) satisfies the following formula (III). 110≦C≦165 Formula (III) <Condition (6)> The length h (cm) of the guide satisfies formula (IV). 150≦h≦5000 Formula (IV) <Condition (7)> The total external surface area S (m 2 ) satisfies equation (V). 2≦S≦50000 Formula (V) <Condition (8)> The perforated plate 1m 2 Average number of holes per m 2 ) satisfies formula (VI). 50≦N≦3000 Formula (VI) <Condition (9)> The upper area T (m 2 ) and the total effective cross-sectional area of ​​the holes Q (m 2 ) satisfies the following formula (VII). 50≦T / Q≦3000 Formula (VII)

[0023]

[12] The amount of liquid used in the evaporation of the low boiling point substance is 1 ton or more per hour. A method for producing the aromatic polycarbonate according to

[10] or

[11] above.

[13] The angle E degrees (°) between the inner side wall surface of the liquid supply zone and the perforated plate, Satisfies the following formula (VIII): The method for producing an aromatic polycarbonate according to

[11] or

[12] above. 100≦E<180 Formula (VIII)

[14] The distance k (cm) between the guide closest to the inner wall surface of the side casing of the evaporation zone and the inner wall surface satisfies the following formula (IX): The method for producing an aromatic polycarbonate according to any one of

[11] to

[13] above. 5≦k≦50 Formula (IX)

[15] The side casing of the evaporation zone is cylindrical with an inner diameter D (cm) and a length L (cm), the bottom casing connected to the lower part of the side casing is cone-shaped, and the liquid outlet at the bottom of the cone-shaped bottom casing is cylindrical with an inner diameter d (cm), The D, L, and d are Satisfying the following formulas (X), (XI), (XII), and (XIII): A method for producing an aromatic polycarbonate according to any one of

[11] to

[14] above. 100≦D≦1800 Formula (X) 5≦D / d≦50 Formula (XI) 0.5≦L / D≦30 Formula (XII) h-20≦L≦h+300 Formula (XIII) (In formula (XIII), h represents the length of the guide.)

[16] In the liquid supply zone from the liquid receiving port to the upper surface of the perforated plate, the space volume V (m 3 ) and the upper area T (m2 ) satisfies the following formula (XIV): The method for producing an aromatic polycarbonate according to any one of

[11] to

[15] above. 0.02(m)≦V / T≦0.5(m) Formula (XIV)

[17] At least one of the guides is cylindrical with an outer diameter r (cm) or a pipe-like structure that prevents liquid and / or gaseous substances from entering the inside, The outer diameter r satisfies the following formula (XV): A method for producing an aromatic polycarbonate according to any one of

[10] to

[16] above. 0.1≦r≦1 Formula (XV)

[18] The guide contact flow-down type polymerization apparatus has a plurality of the guides, The plurality of guides are connected by a support material. A method for producing an aromatic polycarbonate according to any one of

[10] to

[17] above.

[19] The plurality of guides The guide is any one selected from the group consisting of a lattice- or mesh-like guide in which each guide is fixed with a lateral support member, a three-dimensional guide in which a plurality of the lattice- or mesh-like guides are arranged in front and behind and fixed with a lateral support member, and a jungle gym-like three-dimensional guide in which each guide is fixed with a support member in the front, back, left, and right lateral directions. A method for producing an aromatic polycarbonate according to any one of

[10] to

[18] above.

[20] The guide contact flow-down type polymerization apparatus includes: at least one other guide-contact flow-down polymerization apparatus that satisfies the above <Conditions (1)> to <Conditions (9)> is further connected; The two or more guide contact flow-down polymerization apparatuses are connected in any one of series, parallel, and a combination of series and parallel; The method for producing an aromatic polycarbonate according to any one of

[11] to

[19] above. 〔twenty one〕 the guided contact flow-down polymerization apparatus is further connected to another guided contact flow-down polymerization apparatus that satisfies the <conditions (1)> to <conditions (9)>; The total external surface area S1 (m 2 )and, The total external surface area S2 (m 2 )and, but, Satisfies the following formula (XVI): A method for producing the aromatic polycarbonate according to

[20] above. 1≦S1 / S2≦20 (XVI) 〔twenty two〕 an inert gas absorbing device is provided for absorbing an inert gas into the molten aromatic polycarbonate prepolymer before it is supplied to the guide contact flow-down type polymerization apparatus; the pressure of the molten prepolymer into which the inert gas has been absorbed in a molten prepolymer supply pipe between the inert gas absorption device and the guided contact flow-down type polymerization apparatus is maintained at 15 kPaA to 200 kPaA by a pressure regulating valve installed immediately before the inlet of the guided contact flow-down type polymerization apparatus, and the molten prepolymer is supplied to the guided contact flow-down type polymerization apparatus.

[21] A method for producing an aromatic polycarbonate according to any one of

[11] to

[21] . 〔twenty three〕 The guide contact flow-down type polymerization apparatus and the further connected guide contact flow-down type polymerization apparatus each include: an inert gas absorbing device is provided for absorbing an inert gas into the molten aromatic polycarbonate prepolymer before it is fed to each of the guide contact flow-down type polymerization apparatuses; the pressure of the molten prepolymer in which the inert gas has been absorbed in the molten prepolymer supply pipes between the inert gas absorbing device and each of the guided contact flow-down type polymerization devices is maintained at 15 kPaA to 200 kPaA by a pressure regulating valve installed immediately before the inlet of each of the guided contact flow-down type polymerization devices, and the molten prepolymer is supplied. A method for producing an aromatic polycarbonate according to

[21] or

[22] above. 〔twenty four〕 A container that is a molded article of the aromatic polycarbonate according to any one of [1] to [9], A container having a housing portion with a capacity of 3 to 10 gallons. 〔twenty five〕 The housing has a handle portion integrally formed with the housing portion. The container described in

[24] .

[26] The handle has a hollow space, and the hollow space communicates with the internal space of the housing. The container described in

[24] or

[25] . [Effects of the Invention]

[0024] According to the present invention, an aromatic polycarbonate having excellent moldability can be provided. [Brief explanation of the drawings]

[0025] [Figure 1] 1 shows a schematic diagram of an example of the relationship between a predetermined time interval after the start of extension and the extensional viscosity of an aromatic polycarbonate. [Figure 2] 1 shows a schematic diagram of an inert gas absorption device that constitutes an aromatic polycarbonate production apparatus. [Figure 3] 1 shows a schematic diagram of a guide contact flow-down type polymerization apparatus that constitutes an apparatus for producing aromatic polycarbonate. [Figure 4] 1 shows a schematic configuration diagram of an inert gas absorption device and an upper part of a guided contact flow-down type polymerization device. [Figure 5] 1 shows an enlarged schematic diagram of the upper portion of an inert gas absorption device and a guided contact flow-down type polymerization device. [Figure 6] 1 shows a schematic diagram of an example of an apparatus for producing an aromatic polycarbonate of the present invention. [Figure 7] FIG. 2 is a schematic diagram showing another example of the aromatic polycarbonate production apparatus of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, an embodiment of the present invention (hereinafter also referred to as "the present embodiment") will be described in detail. The present invention is not limited to the present embodiment, and can be practiced in various modified forms within the scope of the invention.

[0027] [Aromatic polycarbonate] The aromatic polycarbonate of this embodiment was prepared by subjecting a test piece having a length of 127 mm, a width of 12.7 mm, and a thickness of 0.8 mm to an elongation rate of 0.005 sec at a temperature of 280°C. -1 The index of change in extensional viscosity measured by the following formula satisfies the following <Condition (i)> to <Condition (ii)>, and the melt flow rate (hereinafter referred to as MFR) measured at a temperature of 300°C and a load of 1.2 kg is 1.5 to 4.5 (g / 10 min). FIG. 1 shows a schematic diagram of an example of the relationship between a predetermined time period after the start of extension and the extensional viscosity of an aromatic polycarbonate.

[0028] <Condition (i)> An index of change in extensional viscosity represented by the following formula (1) in section A (the section from 0.30 seconds to 0.80 seconds after the start of extension), (log 10 (Extensional viscosity at 0.80 seconds [Pa s])-log 10 (Extensional viscosity at 0.30 seconds [Pa s]))÷(log 10 0.80-log 10 0.30) Equation (1) The value is 0.10 to 0.30. From the viewpoint of maintaining excellent moldability, the index of change in extensional viscosity represented by formula (1) is 0.10 to 0.30, preferably 0.15 to 0.29, more preferably 0.18 to 0.28, and even more preferably 0.19 to 0.28. When the index of change in extensional viscosity is 0.10 or more, the occurrence of drawdown can be prevented, and when it is 0.30 or less, uneven thickness can be suppressed, particularly in blow molding, and the occurrence of breakage during molding can be prevented.

[0029] <Condition (ii)> An index of change in extensional viscosity in section B (the section from 3.0 seconds to 8.0 seconds after the start of extension) represented by the following formula (2): (log 10 (Extensional viscosity at 8.0 seconds [Pa s])-log 10 (Extensional viscosity at 3.0 seconds [Pa s]))÷(log 10 8.0-log 10 3.0) Equation (2) The value is 0.70 to 1.10. From the viewpoint of maintaining excellent moldability, the value of the index of change in extensional viscosity represented by formula (2) is 0.70 to 1.10, preferably 0.75 to 1.05, more preferably 0.70 to 1.00, even more preferably 0.70 to 0.95, and even more preferably 0.70 to 0.85. When the index of change in extensional viscosity is 0.70 or more, thickness deviation can be suppressed, particularly in blow molding, and the occurrence of breakage during molding can be prevented. Furthermore, when the index is 1.10 or less, the molded body can be prevented from solidifying and becoming unmoldable. Furthermore, when the index is 1.00 or less, the occurrence of fisheyes is suppressed and a resin with a good hue can be obtained. It has been revealed that when a resin is prepared to satisfy the range of formula (1) in order to achieve good moldability, problems with fisheyes and hue arise. However, when formula (2) is set within a predetermined range, excellent moldability is achieved while the occurrence of fisheyes, which is the opposite of this, is suppressed, and a resin with a good hue can be obtained.

[0030] In the aromatic polycarbonate of this embodiment, in a low-extension state as shown in condition (i), the index of change in extensional viscosity is 0.1 to 0.3 in the interval from 0.30 seconds to 0.80 seconds after the start of extension, and the low extensional viscosity makes it easy to stretch and provides excellent moldability.In a high-extension state as shown in condition (ii), the index of change in extensional viscosity is 0.70 to 1.10 in the interval from 3.0 to 8.0 seconds after the start of extension, and the high extensional viscosity makes it less likely to stretch excessively and to cause thickness deviation, thereby increasing the strength of the molded article. If the aromatic polycarbonate of this embodiment further satisfies the following <condition (iii)> to <condition (iv)>, it will have even more excellent moldability.

[0031] <Condition (iii)> An index of the increase in extensional viscosity in the section from 0.30 seconds to 8.0 seconds after the start of the extension, represented by the following formula (3): log 10 (Extensional viscosity at 8.0 seconds [Pa s])-log 10 (Extensional viscosity at 0.30 seconds [Pa·s]) Equation (3) The value is 0.45 to 0.90. From the viewpoint of maintaining excellent moldability, the value of the index of increase in extensional viscosity represented by formula (3) is preferably 0.45 to 0.90, more preferably 0.45 to 0.83, even more preferably 0.45 to 0.80, even more preferably 0.45 to 0.78, and even more preferably 0.45 to 0.75. When the index of increase in extensional viscosity is 0.45 or more, uniform extension can be achieved, and thickness deviation can be suppressed, particularly in blow molding. When the index is 0.90 or less, partial rapid extension can be prevented, and breakage during molding can be prevented, and the molded body can be prevented from solidifying and becoming unmoldable. Furthermore, when the index is 0.80 or less, the occurrence of fisheyes can be suppressed, and a resin with a good color can be obtained.

[0032] <Condition (iv)> An index of extensional viscosity represented by the following formula (4) at 8.0 seconds after the start of the extension: log 10 (Extensional viscosity at 8.0 seconds [Pa·s]) Equation (4) However, it is 4.90 to 5.40. From the viewpoint of maintaining excellent moldability, the value represented by formula (4) is preferably 4.80 to 5.40, more preferably 4.90 to 5.10, even more preferably 5.00 to 5.07, and even more preferably 4.90 to 5.05. When the value of formula (4) is 4.90 or more, concentrated stretching of weak parts can be avoided, and thickness unevenness can be suppressed, particularly in blow molding, and when the value is 5.40 or less, rapid partial stretching can be prevented, which can prevent breakage during molding and prevent the molded body from solidifying and becoming unmoldable. Furthermore, when the value is 5.40 or less, the occurrence of fisheyes can be suppressed and a resin with a good color can be obtained.

[0033] The values ​​of equations (1) to (4) were calculated by subjecting a test piece of 127 mm in length, 12.7 mm in width, and 0.8 mm in thickness to a temperature of 280°C and an elongation rate of 0.005 sec -1 It is calculated using the value of extensional viscosity measured by More specifically, the values ​​of equations (1) to (4) are calculated by molding aromatic polycarbonate pellets dried in a hot air dryer at 120°C for 5 hours into test pieces 127 mm long, 12.7 mm wide, and 0.8 mm thick using an injection molding machine at a cylinder temperature of 300°C and a mold temperature of 90°C, and measuring the extensional viscosity using a rotational viscoelasticity measuring rheometer (ARES-G2, manufactured by TA Instruments Japan, Inc.) under the following <measurement conditions>.

[0034] <Measurement conditions> Measurement mode: Extensional viscosity Measuring fixture: EVF (Extensional Viscosity Fixture) Measurement temperature: 280℃ Residence time 1;60sec.(Wait For TemperatureOn Residence time 2:120sec.(After Pre Stretch) Extension rate: 0.05sec -1 Load cell: 2kg Environmental conditions: nitrogen flow

[0035] The aromatic polycarbonate of the present embodiment can be obtained by controlling the amount of branched structure produced in the production process and introducing a branched structure into the polymer so as to satisfy the above <Condition (i)> to <Condition (iv)>.

[0036] The aromatic polycarbonate of this embodiment preferably has a repeating unit represented by the following general formula (5).

[0037] [ka]

[0038] In formula (5), Ar represents a divalent aromatic residue.

[0039] The aromatic polycarbonate of the present embodiment preferably has repeating units represented by the following general formula (5) in its main chain and branched chains, and contains one or more branched structures selected from the group consisting of branched structures represented by the following general formulae (6), (7), and (8) in its main chain and branched chains, and the ratio of the total amount of the branched structures to the amount of the repeating units represented by the following general formula (5) is 0.9 mol % to 5.0 mol %.

[0040] [ka]

[0041] In the formulae (5), (6), (7) and (8), Ar represents a divalent aromatic residue, and Ar' represents a trivalent aromatic residue.

[0042] From the viewpoint of maintaining the impact strength of the aromatic polycarbonate of this embodiment, the ratio of the total amount of branched structures represented by general formulas (6), (7), and (8) to the amount of repeating units represented by general formula (5) is preferably 0.90 mol % to 5.0 mol %, more preferably 0.95 mol % to 4.0 mol %, even more preferably 1.0 mol % to 3.0 mol %, even more preferably 0.95 mol % to 2.5 mol %, and still more preferably 0.95 mol % to 1.5 mol %. When the ratio of the total amount of branched structures is 1.5 mol % or less, the occurrence of fisheyes is suppressed and a resin with good color can be obtained. The ratio of the total amount of substance of the branched structures represented by general formulas (6), (7), and (8) to the amount of substance of the repeating unit represented by general formula (5) can be measured by LC (liquid chromatography), specifically, by the method described in the Examples below. Furthermore, the ratio of the total amount of branched structures represented by general formulas (6), (7), and (8) to the amount of repeating units represented by general formula (5) can be controlled within the above-mentioned range by adjusting the polymerization conditions for the aromatic polycarbonate of this embodiment.

[0043] Furthermore, the aromatic polycarbonate of the present embodiment can be made to satisfy the above <Conditions (i)> to <Conditions (iv)> by introducing a branched structure into the polymer under high temperature conditions in the aromatic polycarbonate production process described below. Specifically, when the method for producing an aromatic polycarbonate according to the present embodiment includes a step of supplying a nitrogen-absorbed aromatic polycarbonate prepolymer to a guide-contact flow-down polymerization apparatus constituting an aromatic polycarbonate production apparatus, and a step of allowing the prepolymer to flow down along the outer surface of a guide that does not itself have a heat source, and evaporating low-boiling substances, the value K represented by the following formula (9) is in the range of 16.5 to 25.0 in a process region in which the temperature of the polymerization raw materials is 235°C or higher throughout all steps of the aromatic polycarbonate production method.

[0044]

number

[0045] i: Process area numbers assigned in any order to multiple process areas in the manufacturing method Ti: Average temperature of the polymerization raw material in the i-th process area (°C) Hi: Average residence time (hr) of the polymerization raw material in the i-th process zone

[0046] From the viewpoint of maintaining the excellent moldability of the aromatic polycarbonate of this embodiment, the value of K represented by the general formula (9) is preferably 16.5 to 25.0, more preferably 17.5 to 24.0, even more preferably 18.0 to 24.0, and even more preferably 19.5 to 23.5. A K value of 16.5 or more can suppress the occurrence of drawdown, prevent thickness deviation, and prevent breakage during molding, particularly in blow molding. A K value of 25.0 or less can provide a molded article of the aromatic polycarbonate of this embodiment with impact strength sufficient for practical use. The smaller the K value, the better the hue and number of fisheyes, and the larger the K value, the worse the hue and number of fisheyes. When the K value exceeds 25.0, both deteriorate significantly, and both the hue value and the number of fisheyes increase significantly.

[0047] [Constituent materials of aromatic polycarbonate] Hereinafter, the constituent materials of the aromatic polycarbonate of this embodiment are an aromatic dihydroxy compound and a diaryl carbonate.

[0048] (aromatic dihydroxy compounds) The aromatic dihydroxy compound is a compound represented by the formula HO-Ar-OH, where Ar is a divalent aromatic group, such as phenylene, naphthylene, biphenylene, pyridylene, or -Ar 1 -Y-Ar 2 - is a divalent aromatic group represented by the formula: where Ar 1 and Ar 2each independently represents a divalent carbocyclic or heterocyclic aromatic group having 5 to 70 carbon atoms, and Y represents a divalent alkylene group having 1 to 30 carbon atoms. Divalent aromatic group Ar 1 , Ar 2 may have one or more hydrogen atoms substituted with other substituents that do not adversely affect the reaction, such as a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a phenyl group, a phenoxy group, a vinyl group, a cyano group, an ester group, an amide group, or a nitro group. Examples of heterocyclic aromatic groups include aromatic groups having one or more ring-forming nitrogen atoms, oxygen atoms, or sulfur atoms. Divalent aromatic group Ar 1 , Ar 2 Examples of the substituent include substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene, substituted or unsubstituted pyridylene, etc. The substituents here are as described above. The divalent alkylene group Y is, for example, an organic group represented by the following formula:

[0049] [ka]

[0050] In the above formula, R 1 , R 2 , R 3 , R 4 each independently represents hydrogen, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 ring carbon atoms, a carbocyclic aromatic group having 5 to 10 ring carbon atoms, or a carbocyclic aralkyl group having 6 to 10 carbon atoms. k represents an integer from 3 to 11, and R 5 and R 6 are individually selected for each X and independently represent hydrogen or an alkyl group having 1 to 6 carbon atoms, and X represents carbon. Also, R 1 , R 2 , R 3 , R 4 , R 5 , R 6may have one or more hydrogen atoms substituted with other substituents, such as a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a phenyl group, a phenoxy group, a vinyl group, a cyano group, an ester group, an amide group, or a nitro group, as long as the substitution does not adversely affect the reaction.

[0051] Such -Ar 1 -Y-Ar 2 Examples of the divalent aromatic group Ar represented by - include those represented by the following formula:

[0052] [ka]

[0053] In the above formula, R 7 , R 8 are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 ring carbon atoms, or a phenyl group; m and n are integers of 1 to 4; when m is 2 to 4, each R 7 may be the same or different, and when n is 2 to 4, R 8 may be the same or different.

[0054] Furthermore, the divalent aromatic group Ar may be represented by the formula: -Ar 1 -Z-Ar 2 - (In the formula, Ar 1 and Ar 2 is as described above, and Z is a single bond or -O-, -CO-, -S-, -SO2-, -SO-, -COO-, -CON(R 1 )- and other divalent groups. 1 is as mentioned above.)

[0055] Such -Ar 1 -Z-Ar 2 Examples of the divalent aromatic group Ar represented by - include those represented by the following formula:

[0056] [ka]

[0057] In the above formula, R 7 , R 8 , m, and n are as defined above.

[0058] Furthermore, examples of the divalent aromatic group Ar include substituted or unsubstituted phenylene, substituted or unsubstituted naphthylene, and substituted or unsubstituted pyridylene.

[0059] In the formulas (6) to (8), Ar' represents a trivalent aromatic group. Examples of the trivalent aromatic group include aromatic groups in which one hydrogen atom in the above-mentioned divalent aromatic group is a bond.

[0060] The aromatic polycarbonate of this embodiment may have an aromatic terminal group (A″) derived from an aromatic dihydroxy compound or diaryl carbonate at the terminal of the main chain, branched chain, or branched structure shown in the formulas (5) to (8). Examples of such an aromatic terminal group include monovalent aromatic groups having 5 to 20 carbon atoms.

[0061] The aromatic terminal group Ar'' is a monovalent carbocyclic or heterocyclic aromatic group, and one or more hydrogen atoms of this Ar'' may be substituted with other substituents that do not adversely affect the reaction, such as a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a phenyl group, a phenoxy group, a vinyl group, a cyano group, an ester group, an amide group, or a nitro group. When there are a plurality of Ar'', they may be the same or different. Examples of the monovalent aromatic group Ar'' include a phenyl group, a naphthyl group, a biphenyl group, and a pyridyl group. These may be substituted with one or more of the above-mentioned substituents. Preferred examples of Ar'' include those represented by the following formula:

[0062] [ka]

[0063] (diaryl carbonate) Examples of diaryl carbonates include substituted or unsubstituted diphenyl carbonates represented by the following formula:

[0064] [ka]

[0065] In the above formula, R 9 and R 10 are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 ring carbon atoms, or a phenyl group. p and q are integers of 1 to 5, and when p is 2 or more, each R 9 may be different from each other, and when q is 2 or more, each R 10 may be different from each other.

[0066] [Physical properties of aromatic polycarbonate] The aromatic polycarbonate of this embodiment has an MFR (melt flow rate) measured at a temperature of 300°C under a load of 1.2 kg of 1.5 to 4.5 g / 10 min, preferably 1.5 to 3.5 g / 10 min, and more preferably 2.0 to 3.0 g / 10 min, from the viewpoint of moldability. The MFR can be measured by the method described in the examples below.

[0067] The aromatic polycarbonate of this embodiment preferably contains almost no impurities, but when the impurities are alkali metals and / or alkaline earth metals, the content of these metal elements is preferably 0.001 to 1 ppm, more preferably 0.005 to 0.5 ppm, and even more preferably 0.01 to 0.1 ppm. When the content of such metal elements is 1 ppm or less, preferably 0.5 ppm or less, and more preferably 0.1 ppm or less, the physical properties of the aromatic polycarbonate product are not affected. The above-mentioned alkali metal and / or alkaline earth metal contents can be achieved by producing an aromatic polycarbonate using the aromatic polycarbonate production apparatus of the present embodiment described below. The above-mentioned alkali metal and / or alkaline earth metal contents can be measured by IPC (Inductively Coupled Plasma) analysis.

[0068] The halogen content in the aromatic polycarbonate of this embodiment is preferably 10 ppb or less, more preferably 5 ppb or less, and even more preferably 1 ppb or less. As will be described later, such a halogen content can be achieved by producing the aromatic polycarbonate using the aromatic polycarbonate production apparatus of this embodiment using predetermined raw materials. The halogen content can be measured by IPC (Inductively Coupled Plasma) analysis.

[0069] [Method for producing aromatic polycarbonate] The method for producing an aromatic polycarbonate of this embodiment comprises the steps of feeding a nitrogen-absorbed aromatic polycarbonate prepolymer to a guide-contact flow-down polymerization apparatus constituting an aromatic polycarbonate production apparatus (hereinafter sometimes referred to as the aromatic polycarbonate production apparatus of this embodiment), and allowing the prepolymer to flow down along the outer surface of a guide that does not itself have a heat source, thereby evaporating low-boiling substances. The low-boiling substances have a boiling point lower than that of the target aromatic polycarbonate and are by-produced during the production process.

[0070] From the viewpoint of obtaining an aromatic polycarbonate that satisfies the above-mentioned <Condition (i)> to <Condition (iv)>, it is preferable that K represented by the following formula (9) is in the range of 16.5 to 25.0 in the process region where the temperature of the polymerization raw materials is 235°C or higher in all steps of the method for producing an aromatic polycarbonate.

[0071]

number

[0072] i: Process area numbers assigned in any order to multiple process areas in the manufacturing method Ti: Temperature of the polymerization raw material in the i-th process area (°C) Hi: Residence time of the polymerization raw material in the i-th process zone (hr)

[0073] The term "polymerization raw materials" is a concept that encompasses raw materials for an aromatic polycarbonate or aromatic polycarbonate itself, and the term "all steps in the method for producing an aromatic polycarbonate" is a concept that encompasses the process of producing an aromatic polycarbonate from raw materials in the method for producing an aromatic polycarbonate.

[0074] The "process zone" refers to each area of ​​a guide contact flow-down type polymerization apparatus, piping, etc., which will be described later. i is a process area number assigned to a plurality of process areas in an arbitrary order in the manufacturing method, and there is no particular limitation on the division of the process areas. Ti is the temperature (°C) of the polymerization raw material in the i-th process region. For example, the temperature may fluctuate slightly due to process control, and a temperature range may occur, but Ti means the average temperature. Hi is the residence time (hr) of the polymerization raw material in the i-th process zone, and is calculated from the amount of polymerization raw material supplied to each pipe and polymerization apparatus, the pipe size, the internal volume of the polymerization apparatus, the viscosity of the polymerization raw material, etc. The value K is preferably in the range of 18.0 to 24.0, more preferably in the range of 20.0 to 23.0.

[0075] The pressure of the prepolymer supplied to the guided contact flow-down polymerization apparatus constituting the aromatic polycarbonate production apparatus is preferably in the range of 15 kPaA to 200 kPaA, more preferably 20 kPaA to 150 kPaA, and even more preferably 20 to 100 kPaA. In the aromatic polycarbonate production apparatus of the present embodiment described below, in order to maintain the pressure of the molten prepolymer in which the inert gas has been absorbed in the piping between the inert gas absorption apparatus and the guided contact flow-down polymerization apparatus at a predetermined pressure, if the pressure of the molten prepolymer falls below 15 kPaA, it is preferable to install a predetermined pressure regulating valve immediately before the inlet of the guided contact flow-down polymerization apparatus. The inside of the guided contact flow-down polymerization apparatus is at a relatively high vacuum, and the molten prepolymer near the liquid inlet to the guided contact flow-down polymerization apparatus is likely to be sucked in and become under low pressure. As a result, the inert gas absorbed in the inert gas absorption apparatus may separate from the molten prepolymer and aggregate. Therefore, to prevent such separation and aggregation of the inert gas, the prepolymer pressure is preferably within the above-mentioned numerical range. Specifically, the inside of the piping between the gear pump below the inert gas absorption apparatus and the guided contact flow-down type polymerization apparatus is kept at a relatively high pressure (from atmospheric pressure to 15 kPa or more) up to just before the guided contact flow-down type polymerization apparatus due to pressure loss in the piping, etc. Therefore, it is preferable to keep the pressure at 15 kPa or more only just before entering the guided contact flow-down type polymerization apparatus.

[0076] If the prepolymer is fed to the guided contact flow-down type polymerization apparatus at a pressure lower than 15 kPaA immediately before the inlet, the pressure of the molten prepolymer in the upper part of the perforated tray will become unstable, and the inert gas such as nitrogen once absorbed in the molten prepolymer will separate or aggregate, making the uniformity of the molten prepolymer unstable. This will hinder the uniform and continuous foaming of the molten prepolymer in the guided contact flow-down type polymerization apparatus, making it impossible to produce a stable product and increasing the likelihood of foreign matter such as a decrease in color tone and the formation of fish eyes and gels. If the prepolymer pressure cannot be maintained at 15 kPaA or more, it is preferable to install a pressure adjusting valve or the like. On the other hand, even if the pressure exceeds 200 kPaA, the effect remains the same, and excessive load is placed on the discharge gear pump and piping of the inert gas absorption device, which makes it necessary to improve the pressure resistance, which is not realistic. Therefore, the pressure at which the prepolymer is fed into the guide contact flow-down type polymerization apparatus is preferably within the above-mentioned numerical range.

[0077] (Production equipment used in the production method of aromatic polycarbonate) The specific configuration of the aromatic polycarbonate production apparatus of this embodiment used in the aromatic polycarbonate production method of this embodiment will be described below with reference to the drawings.

[0078] FIG. 6 shows a schematic diagram of an example of an apparatus for producing an aromatic polycarbonate according to this embodiment. In an aromatic polycarbonate production apparatus, the polymerization raw materials and catalyst are charged into a mixing tank 31 and mixed, then transferred by a transfer pump 32 to dissolved mixture storage tanks 33A and 33B, and from there further transferred by transfer pumps 34A and 34B to a first polymerization vessel 35 where preliminary polymerization is carried out. Further, prepolymerization is carried out in a second polymerization vessel 37 via a feed pump 36, which is a discharge gear pump, to obtain a prepolymer of aromatic polycarbonate. The aromatic polycarbonate prepolymer is transferred to a first inert gas absorption apparatus 39 via a supply pump 38, and the solubility of the inert gas is adjusted by a pressure control valve 41 before being transferred to a first guided contact flow-down polymerization apparatus 42 where polymerization is carried out. Here, phenol is discharged from a vent as a low-molecular-weight component, which is a low-boiling substance. Next, the inert gas is transferred to a second inert gas absorption apparatus 44 via a feed pump 43, and further transferred from there by feed pumps 46A and 46B. The solubility of the inert gas is adjusted by pressure regulating valves 47A and 47B, and the inert gas is transferred to the connected second guide contact flow-down polymerization apparatuses 48A and 48B, where polymerization is carried out. Here, phenol is discharged from a vent. The mixture is then transported by supply pumps 49A and 49B, and additives are added in downstream equipment 50A and 50B to obtain the desired aromatic polycarbonate. The pressure regulating valves 41, 47A, and 47B that adjust the solubility of the inert gas are not limited in form, and may be valves installed in a specified pipe, or other devices capable of controlling a specified pressure.

[0079] In the method for producing an aromatic polycarbonate of this embodiment, evaporation of low-boiling substances is carried out using a guided contact flow-down polymerization apparatus, and it is preferable that the guided contact flow-down polymerization apparatus satisfies <Condition (1)> to <Condition (9)> described below.

[0080] FIG. 2 shows a schematic diagram of the inert gas absorption devices 39 and 44, and FIG. 3 shows a schematic diagram of the guide contact flow-down type polymerization devices 42, 48A, and 48B. The inert gas absorption apparatus and the guided contact flow-down type apparatus differ in that they each have an inert gas absorption zone in their internal spaces where the inert gas is absorbed and an evaporation zone in which low-boiling-point substances are evaporated, but they share the same basic apparatus structure. 4 and 5 are schematic diagrams showing the upper part of the inert gas absorption device and the guide contact type falling polymerization device.

[0081] In the aromatic polycarbonate production apparatus of the present embodiment, the guide contact flow-down type polymerization apparatus preferably satisfies the following <Condition (1)> to <Condition (9)>. <Condition (1)> The evaporation zone 5 has a liquid receiving port 1, a liquid supply zone 3 for supplying liquid to a guide 4 in the evaporation zone 5 through a perforated plate 2, a plurality of guides 4 extending downward from the perforated plate 2 in a space surrounded by the perforated plate 2, a side casing 10, and a bottom casing 11, a vacuum vent port 6 provided in the evaporation zone 5, and a liquid discharge port 7 provided at the bottom of the bottom casing.

[0082] <Condition (2)> In the liquid supply zone 3, a flow path control component 20 is installed in the liquid supply zone 3, which has the function of flowing the liquid supplied from the liquid receiving port 1 to the perforated plate 2 from the periphery of the perforated plate 2 toward the center.

[0083] <Condition (3)> The internal cross-sectional area A (m 2 ) satisfies the following formula (I): 0.7≦A≦300 Formula (I)

[0084] <Condition (4)> The internal cross-sectional area A (m 2 ) and the internal cross-sectional area B (m 2 ) satisfies formula (II). 20≦A / B≦1000 Formula (II) By satisfying the above formula (II), it is possible to discharge the evaporated and concentrated liquid or polymer, or the melt with increased melt viscosity without deteriorating the quality of the produced polymer.

[0085] <Condition (5)> The bottom casing 11 constituting the bottom of the evaporation zone 5 is connected to the upper side casing 10 at an angle C degrees within the interior thereof, and it is preferable that the angle C (°) satisfies formula (III). 110≦C≦165 Formula (III) In order to reduce equipment costs, it is preferable that C be as close to 90° as possible. However, in order to move the concentrated liquid and polymer melt with increased melt viscosity dropping from the lower end of guide 4 to discharge outlet 7 without deteriorating their quality, it is preferable that C satisfies formula (III).

[0086] <Condition (6)> The length h (cm) of the guide 4 satisfies the formula (IV). 150≦h≦5000 Formula (IV) By setting the length h of the guide 4 to 150 cm or more, concentration and polymerization can be carried out at a speed and quality sufficient for practical use. By setting h to 5000 cm or less, the difference in viscosity of the liquid between the upper and lower parts of the guide 4 is not too large, preventing variations in the degree of concentration and polymerization.

[0087] <Condition (7)> The total external surface area S (m 2 ) satisfies the following formula (V). 2≦S≦50000 Formula (V) S(m 2 ) is 2 or more, it is possible to achieve an evaporated liquid amount of 1 ton or more per hour and a production amount of manufactured polymer. Also, S(m 2 By keeping the molecular weight (Mn) at 50,000 or less, it is possible to achieve this production volume while reducing equipment costs and eliminating variations in physical properties.

[0088] <Condition (8)> The perforated plate 1m 2 Average number of holes per m 2 ) satisfies formula (VI). 50≦N≦3000 Formula (VI) Average number of holes in the perforated plate N (number / m 2 ) is the total number of holes divided by the area of ​​the upper surface of the perforated plate 2 (including the area above the holes) T (m 2 ) is the number divided by

[0089] The holes in the perforated plate 2 are preferably arranged almost uniformly on the plate 2. However, the distance k (cm) between the periphery of the perforated plate 2 and the inner wall surface of the evaporation zone 5 is preferably longer than the distance between adjacent holes. Therefore, the number of holes per unit area at the periphery is preferably smaller than that at the center. In this embodiment, the average number of holes N is used in this sense. A more preferred range for N is 70≦N≦2000, and an even more preferred range is 100≦N≦1000.

[0090] <Condition (9)> The upper area T (m 2 ) and the total effective cross-sectional area Q (m 2 ) satisfies the following formula (VII). 50≦T / Q≦3000 Formula (VII) The T / Q is more preferably 100 to 2,500, and even more preferably 250 to 1,500. The "effective cross-sectional area" of a hole in a perforated plate refers to the area of ​​the narrowest part of the cross section of the hole through which the liquid passes. When a guide 4 penetrates this hole, the effective cross-sectional area is the area obtained by subtracting the cross-sectional area of ​​the guide 4 from the cross-sectional area of ​​the hole. Q(m 2 ) represents the total effective cross-sectional area of ​​the holes.

[0091] The formulas (VI) and (VII) are important for stably carrying out evaporation treatment of large amounts of liquid, particularly highly viscous liquid, over a long period of time.

[0092] By using the aromatic polycarbonate production apparatus of the present embodiment that satisfies the above-mentioned configuration, it is possible to stably produce colorless, high-quality, and high-performance concentrated liquids and polymers at a rate of 1 ton or more per hour for a long period of time, such as several thousand hours or more, for example, 5,000 hours or more.

[0093] It is presumed that the excellent effects of the aromatic polycarbonate production apparatus of the present embodiment are due to the combined effects that are brought about when the various conditions are combined, in addition to the various reasons mentioned above. For example, a guide with a high surface area that satisfies the above formulas (IV) and (V) is very effective for efficient internal stirring and surface renewal of large amounts of liquid, prepolymer, or polymer supplied at relatively low temperatures, enabling efficient evaporation of low-boiling-point substances and helping to obtain large amounts of high-quality concentrated liquid or polymer at rates of 1 ton or more per hour. Furthermore, angle C that satisfies formula (III) shortens the time until the large amount of high-quality concentrated liquid or polymer falling from guide 4 is discharged from liquid outlet 7, thereby reducing thermal history.

[0094] The performance of a guided contact flow-down type polymerization apparatus on an industrial scale can only be established through long-term operation using large-scale production equipment, and the cost of the production equipment in this case is an important factor to be considered. The guide contact flow-down type polymerization apparatus constituting the aromatic polycarbonate production apparatus of this embodiment can reduce the equipment cost relative to performance compared to conventional evaporators and polymerization vessels.

[0095] The ranges required for the specific conditions, dimensions, angles, etc. in the guide contact flow-down polymerization apparatus constituting the aromatic polycarbonate production apparatus of this embodiment are as described above, but more preferred ranges are as follows: The internal cross-sectional area A (m 2 A more preferred range for A is 0.8≦A≦250, and even more preferred is 1≦A≦200. In addition, the internal cross-sectional area A (m 2 ) and the internal cross-sectional area B (m 2 A more preferred range for the ratio of A / B to A / B is 25≦A / B≦900, and even more preferred is 30≦A / B≦800. Furthermore, the more preferred range of angle C (°) that bottom casing 11 constituting the bottom of evaporation zone 5 makes with respect to upper side casing 10 within bottom casing 11 as shown in formula (III) is 120≦C≦165, and even more preferably 135≦C≦165. When the concentration degree or polymerization degree is increased sequentially using a plurality of guide contact flow-down type polymerization apparatuses, where the corresponding angles are C1, C2, C3, . . . , it is preferable that C1≦C2≦C3≦ . . . The required length h (cm) of the guide 4 shown in formula (IV) varies depending on factors such as the amount, viscosity, and temperature of the liquid to be treated, the amount and boiling point of the low-boiling point substance, the pressure and temperature of the evaporation zone, the required concentration level, and the degree of polymerization. A more preferred range is 200≦h≦3000, and even more preferably 400 <h≦2500である。 In addition, the total external surface area S (m 2 ) also varies depending on the same factors as above, but a more preferable range is 10≦S≦40000, and even more preferably 15≦S≦30000. In this specification, the total external surface area of ​​the entire guide means the entire surface area of ​​the guide that comes into contact with and allows liquid to flow down. For example, in the case of a guide such as a pipe, this means the outer surface area, and does not include the surface area of ​​the inner surface of the pipe that does not allow liquid to flow down.

[0096] As shown in FIGS. 2 to 4, liquid receiving port 1 is preferably provided above liquid supply zone 3. As shown in FIGS. The liquid receiving port 1 may be located in one place or in multiple places, but it is preferable to arrange it so that the liquid is supplied to the perforated plate 2 as uniformly as possible in the liquid supply zone 3, and if there is one place, it is preferably located in the center of the upper part of the liquid supply zone 3. In the liquid supply zone 3, a flow path control component 20 is preferably installed, which has the function of directing the flow of liquid supplied from the liquid receiving port 1 to the perforated plate 2 mainly from the periphery to the center of the perforated plate 2. By directing the flow of liquid from the periphery to the center of the perforated plate 2, the flow path control component 20 has the effect of preventing the liquid from remaining for a long period of time in the space between the holes (e.g., 21) of the perforated plate 2 and the inner side wall surface 22 of the liquid supply zone. The liquid that flows mainly from the periphery to the center of the perforated plate 2 is supplied to the guide 4 through the holes in the perforated plate that exist between them.

[0097] The shape of the flow path control component 20 may be any shape as long as it can exert its effect, but it is preferable that the outer shape of its cross section is similar to the outer shape of the cross section of the perforated plate 2. Here, the cross section of the flow path control component 20 refers to the location that shows the largest area when the flow path control component 20 is cut along a plane in the horizontal direction. The preferred range of the distance between the flow path control component 20 and the inner side wall surface 22 of the liquid supply zone 3 varies depending on the amount, viscosity, etc. of the liquid to be treated, but in the guide contact flow-down polymerization apparatus or inert gas absorption apparatus that constitutes the aromatic polycarbonate production apparatus of this embodiment, when the viscosity of the liquid to be handled is relatively high, the distance is usually preferably in the range of 1 cm to 50 cm, more preferably 2 cm to 30 cm, and even more preferably 3 cm to 20 cm.

[0098] 4 and 5, there is a predetermined gap between the upper inner wall surface 23 of the liquid supply zone 3 and the flow path control component 20, and although this gap can be selected arbitrarily, it is preferable to minimize the residence time of the liquid in the liquid supply zone 3. From this perspective, this gap is preferably 1 cm to 200 cm, more preferably 2 cm to 170 cm, and even more preferably 3 cm to 150 cm. The flow path control component 20 can be designed so that the distance between the upper inner wall surface 23 of the liquid supply zone 3 and the flow path control component 20 is approximately the same from the liquid receiving port 1 to the inner side wall surface 22 of the liquid supply zone 3, or the flow path control component 20 can be designed so that the distance gradually narrows, or conversely, gradually widens. The distance between the flow path control component 20 and the perforated plate 2 is usually 1 cm to 50 cm, preferably 2 cm to 30 cm, and more preferably 3 cm to 20 cm. The gap between the perforated plate 2 and the flow path control element 20 may be substantially constant from the inner side wall surface 22 of the liquid supply zone 3 to the center of the perforated plate, or the gap may be gradually narrowed, or conversely, gradually widened. Preferably, the flow path control element 20 has substantially the same gap or a gradually narrowing gap.

[0099] The flow path control component 20 functions as a kind of baffle plate, preventing the liquid supplied from the liquid inlet 1 from being guided directly to the holes in the perforated plate 2. When the area of ​​the perforated plate 2 is large, it is preferable to short-circuit a portion of the supplied liquid to the vicinity of the center of the perforated plate 2 without passing through the periphery of the perforated plate 2, and for this purpose, it is also a preferred embodiment to provide one or more through holes near the center of the flow path control component 20 or in another appropriate portion. In order to prevent the formation of a "dead space" in the liquid supply zone 3, it is further preferable that the angle E (°) between the inner side wall surface 22 of the liquid supply zone and the perforated plate 2 satisfies the following formula (VIII): 100≦E<180 Formula (VIII) Here, when the inner side wall surface 22 of the liquid supply zone is flat, the angle between the inner side wall surface 22 and the perforated plate 2 in a cross section perpendicular to that plane and perpendicular to the upper surface of the perforated plate 2 is E. Furthermore, when the inner side wall surface 22 is a concave curved surface, the angle between the tangent at the point where the curve formed in the cut surface at a plane perpendicular to the concave surface and perpendicular to the upper surface of the perforated plate 2 begins to rise and the upper surface of the perforated plate 2 is E. That is, it is preferable that the horizontal surface of the perforated plate 2 and the inner side wall surface 22 are smoothly connected by forming a curve at the connecting portion, which can prevent the polymer from accumulating and prevent discoloration and the occurrence of fish eyes. A more preferable range of E degree is 120≦E<180, and even more preferable is 145≦E<180. It is also preferable to take measures to prevent the area near the junction between the upper inner wall surface 23 and the inner side wall surface 22 of the liquid supply zone 3 from becoming a "dead space." It is preferable to make the angle between these two surfaces greater than 90°, or, if it is 90° or close to it, to make the area near the junction concave so that liquid does not stagnate.

[0100] In the aromatic polycarbonate production apparatus of this embodiment, it is preferable that the distance k (cm) between the guide 4 closest to the inner wall surface of the side casing 10 of the evaporation zone 5 and the inner wall surface satisfies the following formula (IX): 5≦k≦50 Formula (IX) When liquid adheres to the inner wall surface of the side casing 10 of the evaporation zone 5, evaporation and concentration occur on the inner wall surface, and the concentrated liquid flows down the inner wall surface. However, since the outer wall surface of the side casing is usually heated by steam or a heat medium using a jacket or the like to keep the evaporation zone 5 warm and / or to heat it, or is heated by an electric heater or the like, the liquid adhering to the inner wall surface is more highly concentrated and usually has a higher viscosity than the liquid flowing down the guide 4. Such a viscous liquid spends a longer time flowing down the wall surface (residence time), and becomes even more viscous. Moreover, because the device is usually constantly heated from the outer wall surface, thermal denaturation is likely to occur. This tendency is particularly pronounced when handling highly viscous liquids such as prepolymers and polymers, such as in the case of use as a polymerization reactor or a polymer purification and / or recovery device. In such cases, polymers adhering to the inner wall surface of the evaporation zone 5 are prone to coloration, high molecular weight, and gelation, and the inclusion of such denatured substances is undesirable for the polymer product. Therefore, the distance k (cm) between the guide 4 closest to the inner wall surface and the inner wall surface is preferably long, but in the case of industrial equipment, a short distance is preferred from the viewpoint of manufacturing costs and the aim of achieving high evaporation capacity in as small an apparatus as possible. In the aromatic polycarbonate production apparatus of this embodiment, it is preferable that the range of k (cm) (formula (IX)) is as short as possible without adversely affecting the product. A more preferred range for k (cm) is 10≦k≦40, and an even more preferred range is 12≦k≦30.

[0101] In the aromatic polycarbonate production apparatus of this embodiment, the shape of the internal cross section in the horizontal plane of the side casing 10 of the evaporation zone 5 of the guide contact flow-down type polymerization apparatus may be any shape, such as polygonal, elliptical, or circular. Since the evaporation zone 5 is usually operated under reduced pressure, any shape that can withstand that environment may be used, but a circular or nearly circular shape is preferred. Therefore, the side casing 10 of the evaporation zone 5 is preferably cylindrical. In this case, a cone-shaped bottom casing 11 is preferably installed below the cylindrical side casing 10, and a cylindrical liquid outlet 7 is preferably provided at the bottom of the bottom casing 11.

[0102] In the guide-contact flow-down polymerization apparatus of the aromatic polycarbonate production apparatus of this embodiment, when the side casing 10 and bottom casing 11 of the evaporation zone 5 are each made of the cylindrical and conical portions, and the liquid outlet 7 for the concentrated liquid or polymer is cylindrical, it is preferable that, when the inner diameter of the cylindrical portion of the side casing 10 is D (cm), the length is L (cm), and the inner diameter of the liquid outlet 7 is d (cm), D, L, and d satisfy the following formulas (X), (XI), (XII), and (XIII): 100≦D≦1800 Formula (X) 5≦D / d≦50 Formula (XI) 0.5≦L / D≦30 Formula (XII) h-20≦L≦h+300 Formula (XIII) Here, h is the length (cm) of the guide 4 shown in the above <Condition (6)>.

[0103] In the guide contact flow-down type polymerization apparatus, the range of D (cm) is more preferably 150≦D≦1500, and even more preferably 200≦D≦1200. A more preferable range for D / d is 6≦D / d≦45, and even more preferably 7≦D / d≦40. A more preferable range for L / D is 0.6≦L / D≦25, and even more preferably 0.7≦L / D≦20. A more preferable range for L (cm) is h-10≦L≦h+250, and even more preferable range is h≦L≦h+200. Regarding D, d, and L, it is preferable that the balance between the amount of prepolymer that can be attached to the wire and the size (D) of the polymerization vessel, and the balance between the size of the withdrawal port d at the bottom of the polymerization vessel, fall within the above ranges. The number of wires (i.e., the size of the polymerization vessel (D)) is determined by the amount of prepolymer supplied, and in order to extract the polymer that falls (which has a higher viscosity than the supplied prepolymer due to the progress of polymerization), a pipe diameter (d) corresponding to the viscosity is required. On the other hand, since liquid or melt is continuously supplied to the guide from above, by satisfying the above-mentioned relationship, liquids with approximately the same viscosity or melts with approximately the same melt viscosity and a higher degree of polymerization will continuously fall from the lower end of the guide into the bottom casing. In other words, liquids with approximately the same viscosity and polymers with approximately the same degree of polymerization produced while flowing down the guide will accumulate at the bottom of the bottom casing, allowing for the continuous production of concentrated liquids with a consistent evaporation rate and polymers with a consistent molecular weight. This is one of the excellent features of the guide-contact flow-down polymerization apparatus that constitutes the aromatic polycarbonate production apparatus of this embodiment.

[0104] The concentrated liquid and polymer accumulated in the lower part of the bottom casing 11 are continuously extracted by a discharge pump 8 through a liquid outlet 7, and in the case of polymer, the liquid is normally pelletized continuously through an extruder or the like. In this case, additives and the like can also be added in the extruder.

[0105] In the aromatic polycarbonate production apparatus of this embodiment, the volume of space V (m) in which the liquid can exist in the liquid supply zone 3 is from the liquid supply port 1 (the junction between the liquid supply port 1 and the upper inner wall of the liquid supply zone 3) to the upper surface of the perforated plate 2. 3 ) and the upper area T (m 2 ) preferably satisfies the following formula (XIV): 0.02(m)≦V / T≦0.5(m) Formula (XIV) The spatial volume V (m 3 ) is the substantial volume of the liquid in the liquid supply zone 3 during continuous operation of the guided contact flow-down type polymerization apparatus, excluding the volume of the flow path control component 20. The liquid holding amount in the liquid supply zone 3 is V(m 3), and the smaller this amount, the shorter the residence time in the liquid supply zone 3 and the less adverse effects of thermal denaturation there will be. However, in order to obtain concentrated liquid and / or polymer of a predetermined concentration or degree of polymerization stably over a long period of time at an evaporated rate of 1 ton / hr or more, it is preferable to supply the liquid as evenly as possible to the holes in the perforated plate 2. To achieve this, it is preferable that the value of V / T be within the range of the above-mentioned formula (XIV). A more preferable range for the value of V / T is 0.05 (m)≦V / T≦0.4 (m), and even more preferably 0.1 (m)≦V / T≦0.3 (m).

[0106] Furthermore, in the guide contact flow-down type polymerization apparatus for producing an aromatic polycarbonate according to the present embodiment, the space volume V (m 3 ) and the space volume Y (m 3 ) preferably satisfies the following formula: 10≦Y / V≦500 In order to evaporate a large amount of liquid per unit time stably and efficiently over a long period of time without incurring deterioration of physical properties due to thermal denaturation, the value of Y / V is preferably within this range. A more preferred range of the value of Y / V is 15≦Y / V≦400, and even more preferably 20≦Y / V≦300. The space volume Y (m 3 ) is the spatial volume from the lower surface of the perforated plate 2 to the liquid outlet 7, and includes the volume occupied by the guide.

[0107] In the guide contact flow-down polymerization apparatus constituting the aromatic polycarbonate production apparatus of this embodiment, when one guide 4 is cylindrical with an outer diameter r (cm) or a pipe-like structure that prevents liquids, gaseous substances, or molten prepolymer from entering the inside, it is preferable that the outer diameter r (cm) satisfies the following formula (XV): 0.1≦r≦1 Formula (XV)

[0108] The guide 4 allows the liquid or molten prepolymer to flow downward, allowing evaporation and concentration and polymerization reactions to proceed, but it also has the function of retaining the liquid or molten prepolymer for a certain period of time. This retention time is related to the evaporation time or polymerization reaction time, and as the liquid viscosity or melt viscosity increases as evaporation or polymerization progresses, the retention time and amount increase. The amount of liquid or molten prepolymer that the guide 4 can retain varies depending on the external surface area of ​​the guide 4, i.e., its outer diameter if it is cylindrical or tubular, even if the melt viscosity is the same. Furthermore, the guide 4 installed in the guide contact flow-down type polymerization apparatus must be strong enough to support not only the mass of the guide 4 itself but also the mass of the liquid, molten prepolymer, or polymer that it holds. In this sense, the thickness of the guide 4 is important, and when the guide 4 is cylindrical or tubular, it preferably satisfies the above formula (XV).

[0109] When the outer diameter r (cm) of the guide 4 is 0.1 or more, stable operation over a long period of time is possible in terms of strength. Furthermore, by setting r (cm) to 1 or less, the guide itself can be prevented from becoming excessively heavy, which can avoid inconveniences such as requiring the perforated plate 2 to be very thick to hold them in the guide contact flow-down type polymerization apparatus, and can prevent an increase in the number of areas that hold excessive amounts of liquid, molten prepolymer, or polymer, thereby avoiding inconveniences such as large variations in concentration and molecular weight. In this sense, a more preferable range of the outer diameter r (cm) of the guide 4 is 0.15≦r≦0.8, and even more preferably 0.2≦r≦0.6.

[0110] The positional relationship between the guide 4 and the perforated plate 2, and the positional relationship between the guide 4 and the holes in the perforated plate 2 are not particularly limited as long as the liquid, raw material molten prepolymer, or polymer can come into contact with the guide 4 and flow down. The guide 4 and the perforated plate 2 may or may not be in contact with each other. It is preferable to install guide 4 so as to correspond to the holes in perforated plate 2, but this is not a limitation. The reason is that it is sufficient to design guide 4 so that the liquid, raw material molten prepolymer, or polymer dropping from perforated plate 2 comes into contact with guide 4 at an appropriate position, and guide 4 is not limited to being installed so as to correspond to the holes in perforated plate 2.

[0111] Preferred modes for installing the guide 4 in correspondence with the hole in the perforated plate 2 include, for example, (1) fixing the upper end of the guide 4 to the lower surface of the flow path control component 20, etc., so that the center of the guide 4 is at the center of the hole while the guide 4 penetrates near the center of the hole in the perforated plate 2, (2) fixing the upper end of the guide 4 to the peripheral portion of the upper end of the hole in the perforated plate 2, so that the guide 4 is installed in a state where the guide 4 penetrates the hole in the perforated plate 2, and (3) fixing the upper end of the guide 4 to the lower surface of the perforated plate 2.

[0112] Methods for causing the liquid, raw material molten prepolymer, or polymer to flow down through the perforated plate 2 along the guide 4 include a method of causing it to flow down by a liquid head or its own weight, or a method of applying pressure using a pump or the like to extrude the liquid, raw material molten prepolymer, or polymer from the perforated plate 2. A preferred method is a method in which a predetermined amount of liquid, raw material molten prepolymer, or polymer is supplied under pressure using a supply pump to the liquid supply zone 3, and the liquid, raw material molten prepolymer, or polymer is guided through the perforated plate 2 to the guide 4 and flows down along the guide under its own weight.

[0113] In the aromatic polycarbonate production apparatus of this embodiment, the material of the guide 4 is preferably selected from metals such as stainless steel, carbon steel, Hastelloy, nickel, titanium, chromium, aluminum, and other alloys, and highly heat-resistant polymer materials, etc. Stainless steel is a particularly preferred material. Furthermore, the surface of the guide 4 may be subjected to various treatments as required, such as plating, lining, passivation treatment, acid washing, washing with a solvent or phenol, etc.

[0114] The reason why the aromatic polycarbonate production apparatus of the present embodiment can stably produce high-quality, high-performance concentrated liquids and polymers that are free from coloration, have good hues, and have excellent mechanical properties on an industrial scale for a long period of time (without variations in molecular weight, etc., in the case of polymer production) at high evaporation rates and high polymerization rates is thought to be as follows. That is, in the guide contact flow-down polymerization apparatus constituting the aromatic polycarbonate production apparatus of this embodiment, the raw material liquid is introduced from the liquid receiving port 1 through the liquid supply zone 3 and the perforated plate 2 into the guide 4, and is concentrated or the degree of polymerization increases as it flows down along the guide 4. In this case, the liquid or molten prepolymer undergoes effective internal stirring and surface renewal as it flows down along the guide 4, and low-boiling-point substances are effectively removed, so that concentration or polymerization proceeds at a rapid rate. As the concentration or polymerization proceeds, its viscosity increases, increasing its adhesive force to the guide 4, and the amount of liquid or molten material adhering to the guide 4 increases toward the bottom of the guide 4. This means that the residence time of the liquid or molten prepolymer on the guide 4, i.e., the evaporation time and polymerization reaction time, are increased. Furthermore, the liquid or molten prepolymer flowing downward under its own weight while supported by the guide 4 has an extremely large surface area per mass, and this surface is efficiently renewed, so that evaporation and concentration in a high viscosity range and high molecular weight in the latter half of polymerization, which were impossible to achieve with conventionally known evaporators or mechanically stirred polymerization reactors, can be easily achieved. This is one of the excellent features of the aromatic polycarbonate production apparatus of this embodiment.

[0115] In the guide-contact flow-down polymerization apparatus constituting the aromatic polycarbonate production apparatus of this embodiment, the amount of liquid or melt adhering to the guide 4 increases in the latter half of evaporation and polymerization. However, since the adhesive holding force is only commensurate with the viscosity, approximately the same amount of liquid or melt with approximately the same viscosity is supported by each guide 4 at the same height. Meanwhile, since liquid or melt is continuously supplied to the guide 4 from above, liquids with approximately the same viscosity or melts with approximately the same melt viscosity and a higher degree of polymerization continuously fall from the lower end of the guide 4 into the bottom casing 11. In other words, liquids with approximately the same viscosity and polymers with approximately the same degree of polymerization produced while flowing down the guide 4 accumulate at the bottom of the bottom casing 11. This allows for the continuous production of concentrated liquids with uniform evaporation levels and polymers with uniform molecular weights. This is one of the excellent features of the aromatic polycarbonate production apparatus of this embodiment. The concentrated liquid and polymer accumulated in the lower part of the bottom casing 11 are continuously extracted by a discharge pump 8 through a liquid outlet 7, and in the case of polymer, the liquid is normally pelletized continuously through an extruder or the like. In this case, additives and the like can also be added in the extruder.

[0116] The perforated plate 2 constituting the guide contact flow-down type polymerization apparatus is usually selected from flat plates, corrugated plates, plates thickened in the center, etc. The cross-sectional shape of the perforated plate 2 is usually selected from circular, oval, triangular, polygonal, etc. The cross section of the holes in the perforated plate is usually selected from shapes such as circular, elliptical, triangular, slit-like, polygonal, and star-like. The cross-sectional area of ​​the hole is usually 0.01 to 100 cm 2 and preferably 0.05 to 10 cm 2 and more preferably 0.1 to 5 cm 2 The spacing between holes, measured from the center of the holes, is usually 1 to 500 mm, and preferably 10 to 100 mm. The holes in the perforated plate 2 may be holes that penetrate the perforated plate 2, or may be holes to which pipes are attached. The holes may also be tapered.

[0117] In the guide contact flow-down type polymerization apparatus, it is preferable that the perforated plate 2 and its holes satisfy the formulas (VI) and (VII) as described above. Furthermore, the guide 4 constituting the guide contact flow-down type polymerization apparatus does not have a heat source such as a heat medium or electric heater inside itself, and is preferably made of a material in which the ratio of the length in the direction perpendicular to the cross section to the average length of the circumference of the horizontal cross section is very large. The ratio (length in the direction perpendicular to the cross section / average length of the circumference of the horizontal cross section) is usually in the range of 10 to 1,000,000, and preferably in the range of 50 to 100,000.

[0118] The horizontal cross-sectional shape of the guide 4 is usually selected from shapes such as a circle, an oval, a triangle, a rectangle, a polygon, and a star. The cross-sectional shape of the guide 4 may be the same or different in the longitudinal direction. The guide 4 may also be hollow. The guide 4 constituting the aromatic polycarbonate production apparatus of this embodiment does not have a heat source itself, and therefore has a major feature in that there is absolutely no concern about thermal denaturation of the liquid on the surface of the guide 4.

[0119] The guide 4 may be a single member such as a wire, a thin rod, or a thin pipe that prevents liquid or molten prepolymer from entering inside, or may be a combination of multiple members twisted together, etc. Also, the guide 4 may be a mesh or punched plate. The surface of the guide 4 may be smooth or uneven, and may partially have protrusions, etc. Preferred guides 4 are those in the form of a column such as a wire or thin rod, the above-mentioned thin pipe, a mesh, or a punched plate.

[0120] In the guide-contact flow-down polymerization apparatus constituting the aromatic polycarbonate production apparatus of this embodiment, which enables the production of high-quality concentrated liquids and polymers on an industrial scale (production volume, long-term stable production, etc.), a particularly preferred embodiment is a configuration having a plurality of guides connected by a predetermined support material. For example, a configuration in which a plurality of wire-shaped, thin rod-shaped, or thin pipe-shaped guides 4 are connected at appropriate intervals from top to bottom using lateral support materials can be mentioned. Specific examples of guides include lattice- or mesh-like guides in which multiple wire-, thin rod-, or thin pipe-like guides are fixed at appropriate vertical intervals, for example, 1 cm to 200 cm, using horizontal support materials from top to bottom; three-dimensional guides in which multiple lattice- or mesh-like guides are arranged front to back and connected at appropriate vertical intervals, for example, 1 cm to 200 cm, using horizontal support materials; and three-dimensional jungle gym-like guides in which multiple wire-, thin rod-, or thin pipe-like guides are fixed at appropriate vertical intervals, for example, 1 cm to 200 cm, using horizontal support materials from front to back and left to right. Lateral supports not only help maintain the same spacing between each guide, but also strengthen the overall strength of the guides, whether they are flat, curved, or three-dimensional. These supports may be made of the same material as the guides, or a different material.

[0121] The guided contact flow-down polymerization apparatus constituting the aromatic polycarbonate production apparatus of this embodiment is an apparatus that has the function of evaporating a low-boiling substance from a liquid when the liquid contains the substance having a boiling point lower than that of the liquid. This liquid may be at room temperature, but is usually heated when it is supplied to the guided contact flow-down polymerization apparatus from the liquid inlet 1. In addition, it is usually preferable that a jacket or the like is installed on the outer wall surface of this guided contact flow-down polymerization apparatus, and by passing steam, a heat medium, or the like through this jacket as needed, the liquid supply zone 3, flow path control component 20, and perforated plate 2 are heated and kept warm, and the evaporation zone 5 and perforated plate 2 are kept warm, etc.

[0122] The guided contact flow-down polymerization apparatus constituting the aromatic polycarbonate production apparatus of this embodiment can be used not only as an apparatus for simply concentrating liquids, but also as an evaporation apparatus for relatively high-viscosity liquids, such as a polymerization apparatus for condensation polymers, an apparatus for purifying thermoplastic polymers containing low-boiling-point substances such as monomers, oligomers, and by-products, or an apparatus for separating and recovering said polymers from a thermoplastic polymer solution. Therefore, the guided contact flow-down polymerization apparatus constituting the aromatic polycarbonate production apparatus of this embodiment uses, as the liquid supplied from the liquid supply zone 3, a monomer for producing a condensation polymer, a mixture of two or more monomers, a prepolymer of the condensation polymer, and a melt of the condensation polymer containing a by-product low-boiling substance produced in the polycondensation reaction, and by evaporating and removing the low-boiling substance from the melt, it is possible to improve the degree of polymerization of the prepolymer of the condensation polymer and / or the polymer.

[0123] As the condensation polymer, polycarbonates such as aliphatic polycarbonate, aromatic polycarbonate and various copolycarbonates; polyester polycarbonates, etc. are preferred. By using an aromatic polycarbonate production apparatus equipped with the above-described guided contact flow-down type polymerization apparatus, it is possible to stably produce high-purity, high-performance condensation polymers that are free from coloration, gel-like substances, and solid foreign matter and have no variation in molecular weight over a long period of time.

[0124] The guided contact flow-down polymerization apparatus constituting the aromatic polycarbonate production apparatus of this embodiment is suitable for evaporating and removing low boiling point substances from a liquid with a relatively high viscosity. For example, when a guided contact flow-down type polymerization apparatus is used as a polymerization apparatus for a condensation polymer, in conventionally known polymerization apparatuses, there are places where a part of the liquid remains heated for a long time and accumulates, and as a result, the accumulated liquid undergoes modifications such as coloration, gelation, crosslinking, formation of an ultrahigh molecular weight, solidification, burning, and carbonization, and these modifications are unavoidably mixed into the polymer gradually or intensively. However, the guided contact flow-down type polymerization apparatus constituting the production apparatus for an aromatic polycarbonate of the present embodiment not only does not have such defects but also has excellent effects not found in conventional polymerization apparatuses. For example, when an aromatic polycarbonate is produced by polymerizing a molten prepolymer obtained from an aromatic dihydroxy compound and a diaryl carbonate, the reaction temperature typically needs to be in the range of 200 to 350°C. The viscosity increases rapidly, particularly in the latter half of the polymerization. The aromatic monohydroxy compound, which is a by-product of the equilibrium reaction, must be extracted from this ultra-high viscosity substance. Therefore, when a conventional polymerization vessel, such as a horizontal twin-screw agitator reactor for ultra-high viscosity polymers, is used, the reaction must be carried out at a high temperature of 300°C or higher for a long period of time under a high vacuum of 133 Pa or lower, and it has been difficult to produce high molecular weight products, such as those for sheets. However, in the guided contact flow-down polymerization apparatus constituting the aromatic polycarbonate production apparatus of this embodiment, efficient surface renewal accompanied by internal stirring is performed, so the polymerization reaction can proceed at a relatively low temperature. Therefore, the preferred reaction temperature is 100 to 290°C, more preferably 150 to 270°C. The aromatic polycarbonate production apparatus of this embodiment is characterized in that polymerization can be sufficiently carried out at a lower temperature than in conventional polymerization vessels using mechanical stirring, and this is also one of the factors that enable the production of high-quality aromatic polycarbonate without coloration or deterioration in physical properties. Furthermore, conventionally known polymerization reactors have the drawback of leaking air or the like through the seal of the agitator under high vacuum, or of introducing foreign matter. However, the guide-contact flow-down polymerization apparatus constituting the production apparatus for aromatic polycarbonate of the present embodiment has no mechanical agitation and no seal of the agitator, so that leakage of air or the like and introduction of foreign matter are extremely low, and a high-purity, high-performance aromatic polycarbonate can be produced.

[0125] When a condensation polymer is produced using the aromatic polycarbonate production apparatus of this embodiment, the reaction rate can be increased by removing low-boiling substances by-produced by the equilibrium reaction as the polymerization reaction proceeds. Therefore, a method in which an inert gas that does not adversely affect the reaction, such as nitrogen, argon, helium, carbon dioxide, or a lower hydrocarbon gas, is introduced into the guided contact flow-down polymerization apparatus and the low-boiling substances are removed by being entrained by the gas, or a method in which the polymerization reaction is carried out under reduced pressure, is preferably used. Alternatively, a combination of these methods is also preferably used. Even in this case, it is not necessary to introduce a large amount of inert gas into the guided contact flow-down polymerization apparatus; it is sufficient to simply maintain the interior in an inert gas atmosphere.

[0126] Furthermore, when a condensation polymer is produced using the aromatic polycarbonate production apparatus of this embodiment, the reaction pressure in the guided contact flow-down polymerization apparatus varies depending on the type of by-product low-boiling point substance, the type and molecular weight of the polymer produced, the polymerization temperature, etc., but for example, when an aromatic polycarbonate is produced from a molten prepolymer using bisphenol A and diphenyl carbonate, if the number average molecular weight of the aromatic polycarbonate is 5,000 or less, the range of 400 to 3,000 PaA is preferred, and if the number average molecular weight is 5,000 to 10,000, the range of 50 to 500 PaA is preferred. If the number average molecular weight is 10,000 or more, the range of 300 PaA or less is preferred, and a range of 20 to 250 PaA is particularly preferred.

[0127] When a condensation polymer is produced using the guided contact flow-down polymerization apparatus constituting the aromatic polycarbonate production apparatus of the present embodiment as a polymerization vessel, it is possible to produce a polymer having a desired degree of polymerization using only one guided contact flow-down polymerization apparatus. However, a system may be adopted in which two or more guided contact flow-down polymerization apparatuses are connected together to sequentially increase the degree of polymerization depending on the degree of polymerization of the molten monomer or molten prepolymer used as raw materials, the production amount of the polymer, and the like. In such a case, two or more guide contact flow-down type polymerization apparatuses are preferably connected in any one of series, parallel, and a combination of series and parallel.

[0128] In this case, guides and reaction conditions suitable for the degree of polymerization of the prepolymer or polymer to be produced can be separately adopted in each guide contact flow-down type polymerization apparatus. For example, in the case of a system in which a first guide contact flow-down type polymerization apparatus, a second guide contact flow-down type polymerization apparatus, a third guide contact flow-down type polymerization apparatus, a fourth guide contact flow-down type polymerization apparatus, etc. are used and the degree of polymerization is increased in this order, then if the total external surface areas of the entire guides of each polymerization apparatus are S1, S2, S3, S4, etc., then S1≧S2≧S3≧S4≧ The polymerization temperature may be the same in each polymerization apparatus, or may be increased in sequence. The polymerization pressure can also be decreased in sequence in each polymerization apparatus. In this sense, for example, when two polymerization apparatuses, a first guide contact flow-down type polymerization apparatus and a second guide contact flow-down type polymerization apparatus, are used to increase the degree of polymerization in this order, the total external surface area S1 (m 2 ) and the total external surface area S2 (m 2 It is preferable to use a guide in which the following formula (XVI) is satisfied: 1≦S1 / S2≦20 Formula (XVI) When the S1 / S2 ratio is 1 or more, variations in molecular weight can be suppressed, stable production over a long period of time becomes possible, and a desired production amount can be obtained. By keeping S1 / S2 at 20 or less, the flow rate of the molten prepolymer flowing down the guide in the second polymerization apparatus can be suppressed, thereby ensuring sufficient residence time for the molten prepolymer and producing a polymer with the required molecular weight. A more preferred range is 1.5≦S1 / S2≦15.

[0129] In the aromatic polycarbonate production apparatus of this embodiment, it is preferable to further install an inert gas absorption device for absorbing an inert gas into the molten prepolymer of the condensation polymer before it is supplied to the guided contact flow-down polymerization apparatus. Furthermore, when a plurality of guided contact flow-down type polymerization apparatuses are connected in series, it is preferable that each polymerization apparatus is provided with an inert gas absorption apparatus for absorbing an inert gas into the molten prepolymer of the condensation polymer before it is fed to the guided contact flow-down type polymerization apparatus. The installation of the inert gas absorption apparatus can further enhance the effects of the present invention.

[0130] Hereinafter, a case where one guide contact flow-down type polymerization apparatus and one inert gas absorption apparatus are used in combination will be described. Before being supplied to a guided contact flow-down polymerization apparatus, the molten prepolymer is introduced into an inert gas absorption apparatus. In the inert gas absorption apparatus, the molten prepolymer is treated with an inert gas to cause the molten prepolymer to absorb the inert gas, thereby causing the molten prepolymer to absorb a specific amount of inert gas of 0.0001 to 1 N liters (N liters is the volume measured under standard temperature and pressure conditions) per 1 kg of molten prepolymer. The molten prepolymer having absorbed this specific amount of inert gas is then supplied to a guided contact flow-down polymerization apparatus and polymerized.

[0131] Treating the molten prepolymer with an inert gas means that the molten prepolymer is made to absorb the inert gas under conditions that make it difficult for the molten prepolymer to polymerize. The amount of inert gas absorbed into the molten prepolymer is preferably 0.0001 to 1 N liter, more preferably 0.001 to 0.8 N liter, and even more preferably 0.005 to 0.6 N liter per 1 kg of the molten prepolymer. If the amount of absorbed inert gas is less than 0.0001 N liter per kg of the molten prepolymer, the effect of increasing the polymerization rate achieved by using the inert gas-absorbing prepolymer and the effect of stably producing an aromatic polycarbonate achieved by using the inert gas-absorbing prepolymer will be reduced. Also, in the present invention, it is not necessary for the amount of absorbed inert gas to be more than 1 N liter per kg of the molten prepolymer. The effects of the present invention are further enhanced when the molten prepolymer having absorbed therein an amount of inert gas within the above-mentioned numerical range is polymerized in a guide contact flow-down type polymerization apparatus that constitutes the aromatic polycarbonate production apparatus of this embodiment.

[0132] The amount of inert gas absorbed into the molten polymer can usually be easily measured by directly measuring the amount of inert gas supplied. When an inert gas is absorbed into the molten prepolymer while flowing through the inert gas absorption device, the amount of inert gas absorbed can be determined from the difference between the amount of inert gas supplied and the amount of inert gas discharged. The amount of inert gas absorbed can also be measured by supplying a predetermined amount of molten prepolymer to an inert gas absorption device charged with inert gas at a predetermined pressure, and measuring the amount of pressure drop in the inert gas absorption device caused by the inert gas being absorbed into the molten prepolymer. The amount of inert gas absorbed can also be measured by a batch method in which a predetermined amount of molten prepolymer is supplied to the absorption device in batches and then the amount of inert gas absorbed is measured, or by a continuous method in which the molten prepolymer is continuously supplied to the absorption device and the amount of inert gas absorbed is measured while continuously withdrawing it.

[0133] In this embodiment, the molten prepolymer is treated with an inert gas using an inert gas absorption device under a predetermined pressure and under conditions that make it difficult for the molten prepolymer to polymerize, thereby absorbing the inert gas. Absorbing the inert gas into the molten prepolymer means dispersing and / or dissolving the inert gas in the molten prepolymer. Dispersion refers to a state in which the inert gas is mixed in the molten prepolymer in the form of bubbles, forming a gas-liquid mixed phase, and dissolution refers to a state in which the inert gas is mixed with the molten prepolymer, forming a uniform liquid phase. It is particularly preferred that the inert gas be dissolved in the molten prepolymer, rather than merely dispersed therein. In order to efficiently dissolve the inert gas in the molten prepolymer, it is preferable to increase the gas-liquid interfacial area to improve contact efficiency, or to carry out the reaction under pressurized inert gas.

[0134] The inert gas absorption device constituting the aromatic polycarbonate production apparatus of this embodiment is not particularly limited in type as long as it is an apparatus capable of absorbing an inert gas into a molten prepolymer. Examples include known apparatuses such as a packed tower type absorption device, a tray type absorption device, a spray tower type absorption device, a fluidized packed tower type absorption device, a liquid film cross-flow absorption type absorption device, a high-speed swirl flow type absorption device, and a mechanical power type absorption device, as described in Chemical Plant Design and Operation Series No. 2, Revised Gas Absorption, pp. 49-54 (published by Kagaku Kogyosha, March 15, 1981), and an apparatus configured to absorb the molten prepolymer while allowing it to fall along a guide under an inert gas atmosphere. Alternatively, the inert gas may be directly supplied into a pipe for supplying the molten prepolymer to the guided contact flow-down polymerization apparatus, and the inert gas may be absorbed therein. As the inert gas absorbing apparatus, it is particularly preferable to use the above-mentioned spray tower type absorbing apparatus or an apparatus configured to absorb the inert gas while allowing the molten prepolymer to fall along a guide.

[0135] As the inert gas absorption apparatus, an apparatus of the same type as the guided contact flow-down type polymerization apparatus is particularly preferred. Since an inert gas absorption apparatus is operated under conditions that do not allow polymerization to proceed at all, it is functionally completely different from a polymerization apparatus. However, an outstanding feature of an inert gas absorption apparatus of the same type as a guide contact flow-down type polymerization apparatus is that the surface area per mass of the molten prepolymer flowing down the guide is very large, and this, combined with very good surface renewal and internal stirring of the molten prepolymer, enables very efficient inert gas absorption in a short period of time. Unlike a guided contact flow-down type polymerization apparatus, in an inert gas absorption apparatus, there is almost no change in the viscosity of the molten prepolymer between the top and bottom of the guide, so the processing capacity of the molten prepolymer per unit time is large. Therefore, even if the inert gas absorption apparatus is of the same type, it can generally be made smaller than a guided contact flow-down type polymerization apparatus.

[0136] The production of the aromatic polycarbonate preferred in this embodiment will be described. When the number average molecular weights of the molten prepolymer before and after inert gas absorption are M1 and M2, respectively, the change in molecular weight (M2-M1) before and after inert gas absorption is preferably substantially 2,000 or less, more preferably 1,000 or less, and even more preferably 500 or less. The temperature at which the molten prepolymer absorbs the inert gas is not particularly limited as long as it is in a molten state, but is usually in the range of 150 to 350°C, preferably 180 to 300°C, and more preferably 230 to 270°C.

[0137] The pressure Pg (PaA) at which the inert gas is absorbed into the molten prepolymer is preferably equal to or greater than the pressure used to produce the molten prepolymer. That is, it is preferable to absorb the inert gas under pressure conditions that are the same as or higher than the reaction pressure used in producing a molten prepolymer of an aromatic polycarbonate by reacting an aromatic dihydroxy compound with a diaryl carbonate. Furthermore, Pg (PaA) is a pressure higher than the pressure Pp (PaA) of the polymerization reaction in the subsequent guided contact flow-down type polymerization apparatus, and it is preferable that Pg (PaA) satisfies the following relationship with M1 (the number average molecular weight of the molten prepolymer before inert gas absorption): Formula: Pg > 4 × 10 12 × M1 -2.6871 If Pg(PaA) does not satisfy the relationship of the above formula, the effect of increasing the polymerization rate achieved by using the inert gas-absorbing prepolymer and the effect of stably producing an aromatic polycarbonate achieved by using the inert gas-absorbing prepolymer will be reduced. It is particularly preferable that the pressure when the inert gas is absorbed is normal pressure or increased pressure, since this increases the rate at which the inert gas is absorbed into the molten prepolymer, and as a result, the size of the absorption device can be reduced. There is no particular upper limit to the pressure during inert gas absorption, but it is usually 2 × 10 7 PaA or less, preferably 1 x 10 7 PaA or less, preferably 5 x 10 6 Inert gas absorption is carried out under a pressure of PaA or less.

[0138] The method for absorbing the inert gas into the molten prepolymer in the inert gas absorption device may be a method in which most of the inert gas supplied to the inert gas absorption device is absorbed into the molten prepolymer, or a method in which only a part of the supplied inert gas is absorbed into the molten prepolymer. Examples of the former method include a method using a spray tower type absorption apparatus or an apparatus in which a molten prepolymer is allowed to fall along a guide and absorb an inert gas, and supplying an inert gas in an amount substantially equal to the inert gas absorbed in the molten prepolymer while maintaining the pressure in the inert gas absorption apparatus substantially constant, thereby allowing the inert gas to be absorbed into the molten prepolymer; and a method using an inert gas absorption apparatus in which an inert gas is supplied directly into a pipe through which the molten prepolymer is supplied to a polymerization reactor. Examples of the latter method include a method in which a spray tower type absorption apparatus or an apparatus in which a molten prepolymer is allowed to fall along a guide and absorbs an inert gas therein is used as an inert gas absorption apparatus, in which an amount of inert gas greater than that which can be absorbed into the molten prepolymer is circulated through the inert gas absorption apparatus, and the excess inert gas is discharged from the inert gas absorption apparatus. The former method is particularly preferred from the viewpoint of reducing the amount of inert gas used.

[0139] Also possible are a continuous method in which molten prepolymer is continuously supplied to an inert gas absorption device to allow the molten prepolymer to absorb the inert gas, and the molten prepolymer having absorbed the inert gas is continuously withdrawn, and a batch method in which molten prepolymer is batchwise charged into an inert gas absorption device to allow the inert gas to be absorbed.

[0140] The inert gas is a general term for a gas that does not undergo a chemical reaction with the molten prepolymer and is stable under polymerization conditions. Examples of the inert gas include nitrogen, argon, helium, carbon dioxide, organic compounds that are gaseous at the temperature at which the prepolymer maintains a molten state, and lower hydrocarbon gases having 1 to 8 carbon atoms, with nitrogen being particularly preferred.

[0141] In the method for producing an aromatic polycarbonate of this embodiment, in the above-mentioned guided contact flow-down polymerization apparatus, in order to maintain the pressure of the molten prepolymer into which the inert gas has been absorbed in the molten prepolymer supply pipe between the inert gas absorption device and the guided contact flow-down polymerization apparatus at a predetermined pressure, it is preferable to install a predetermined pressure regulating valve, as necessary, immediately before the inlet of the guided contact flow-down polymerization apparatus, thereby controlling the pressure of the molten prepolymer. The inside of a guided contact flow-down polymerization apparatus is at a relatively high vacuum, and the molten prepolymer near the feed port to the guided contact flow-down polymerization apparatus is likely to be sucked into the guided contact flow-down polymerization apparatus, resulting in a low pressure. As a result, the inert gas absorbed in the inert gas absorption device may separate from or aggregate with the molten prepolymer. Therefore, to prevent these problems, it is preferable to supply the molten prepolymer to the guided contact flow-down polymerization apparatus while maintaining the pressure at or above the pressure at which the inert gas is absorbed into the molten prepolymer in the inert gas absorption device. Specifically, the pressure of the molten prepolymer when it is fed is preferably in the range of 15 kPaA to 200 kPaA, more preferably 20 kPaA to 150 kPaA, and even more preferably 20 to 100 kPaA. When a guided contact flow-down polymerization apparatus and another guided contact flow-down polymerization apparatus connected thereto are provided, an inert gas absorbing apparatus may be installed to absorb inert gas into the molten prepolymer before it is supplied to each of the guided contact flow-down polymerization apparatuses. In this case, it is preferable to install a pressure regulating valve immediately before the inlet of each of the guided contact flow-down polymerization apparatuses to maintain the pressure of the molten prepolymer, from which the inert gas has been absorbed, at 15 kPaA to 200 kPaA before supplying the molten prepolymer. The pressure is more preferably 20 kPaA to 150 kPaA, and even more preferably 20 to 100 kPaA.

[0142] If the pressure of the molten prepolymer is less than 15 kPaA or is lower than the pressure at which the molten prepolymer absorbs the inert gas, the pressure of the molten prepolymer in the piping will become unstable, and the inert gas, such as nitrogen, once absorbed by the molten prepolymer will separate or aggregate, making the uniformity of the molten prepolymer unstable. This will hinder the uniform and continuous foaming of the molten prepolymer in the guided contact flow-down type polymerization apparatus, making it impossible to produce stable products and making it more likely that foreign matter such as color tone, fish eyes, and gels will occur. On the other hand, even if the pressure exceeds 200 kPaA, the effect will not change, and excessive load will be placed on the exhaust gear pump and piping of the inert gas absorption device, which is not realistic and requires improving the pressure resistance, so it is preferable to set the upper limit at 200 kPaA.

[0143] The aromatic polycarbonate production apparatus of this embodiment may be any apparatus that satisfies the various conditions described above and has mechanical strength corresponding thereto, and may be equipped with any other apparatus or facility having any other function necessary for continuous operation. Furthermore, the aromatic polycarbonate production apparatus of this embodiment may be a combination of a plurality of the above-mentioned guided contact flow-down type polymerization apparatuses and inert gas absorption apparatuses, or may be an apparatus to which any apparatus or facility having any function other than evaporation is added.

[0144] (Materials used in the production method of aromatic polycarbonate) The aromatic dihydroxy compound and diaryl carbonate, which are materials used in the method for producing the aromatic polycarbonate of this embodiment, will be described below.

[0145] <Aromatic dihydroxy compounds> The aromatic dihydroxy compound used in producing the aromatic polycarbonate is a compound represented by the following formula: HO-Ar-OH (wherein Ar represents a divalent aromatic group). The divalent aromatic group Ar is as defined above.

[0146] The aromatic dihydroxy compound used in the method for producing an aromatic polycarbonate of this embodiment may be one type alone or two or more types. A preferred example of the aromatic dihydroxy compound is bisphenol A. A trivalent aromatic trihydroxy compound may also be used in combination to introduce a branched structure. Particularly preferred bisphenol A is a high-purity product for polycarbonate with a chlorine content of 1 ppb or less.

[0147] <Diaryl carbonate> The diaryl carbonate used in the method for producing an aromatic polycarbonate of this embodiment is represented by the following formula.

[0148] [ka]

[0149] In the above formula, Ar'' represents a monovalent aromatic group having 5 to 20 carbon atoms. In this Ar'', one or more hydrogen atoms may be substituted with other substituents that do not adversely affect the reaction, such as a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a phenyl group, a phenoxy group, a vinyl group, a cyano group, an ester group, an amide group, or a nitro group. Ar'' may be the same or different. Examples of the monovalent aromatic group Ar'' include a phenyl group, a naphthyl group, a biphenyl group, and a pyridyl group. These may be substituted with one or more of the above-mentioned substituents.

[0150] Among these diaryl carbonates, symmetric diaryl carbonates such as unsubstituted diphenyl carbonate and lower alkyl-substituted diphenyl carbonates such as ditolyl carbonate and di-t-butylphenyl carbonate are preferred, with diphenyl carbonate being particularly preferred, as it is the diaryl carbonate with the simplest structure. These diaryl carbonates may be used alone or in combination of two or more.

[0151] Diphenyl carbonate, which is a raw material for producing aromatic polycarbonate, is particularly preferably diphenyl carbonate produced and purified by reacting ethylene carbonate, which has been produced and purified by reacting ethylene carbonate with ethylene oxide and CO2, with methanol to produce and purified dimethyl carbonate, which has been reacted with purified phenol by reactive distillation; this diphenyl carbonate is an ultra-high purity product that does not contain alkali metals, alkaline earth metals, or chlorine.

[0152] <Molten prepolymer> The molten prepolymer used in producing the aromatic polycarbonate of this embodiment is produced from the aromatic dihydroxy compound and diaryl carbonate. The ratio of use (feed ratio) varies depending on the types of aromatic dihydroxy compound and diaryl carbonate used, the polymerization temperature, and other polymerization conditions. However, the diaryl carbonate is usually used in a ratio of 0.9 to 2.5 moles, preferably 0.95 to 2.0 moles, and more preferably 0.98 to 1.5 moles per mole of the aromatic dihydroxy compound.

[0153] The molten prepolymer (molten prepolymer) produced from the aromatic dihydroxy compound and diaryl carbonate refers to a molten product produced from the aromatic dihydroxy compound and diaryl carbonate in the middle of polymerization and having a lower degree of polymerization than the aromatic polycarbonate having the desired degree of polymerization, and may be an oligomer.

[0154] The average degree of polymerization of the molten prepolymer of the aromatic polycarbonate of this embodiment is not particularly limited and varies depending on its chemical structure, but is usually about 2 to 2,000. Such a molten prepolymer used as a polymerization raw material may be obtained by any known method.

[0155] <Catalyst> The reaction for producing an aromatic polycarbonate from an aromatic dihydroxy compound and a diaryl carbonate can be carried out without adding a catalyst, but is carried out in the presence of a catalyst, if necessary, to increase the polymerization rate. There are no particular limitations on the catalyst as long as it is used in this field. Examples of the catalyst include hydroxides of alkali metals and alkaline earth metals such as lithium hydroxide, sodium hydroxide, potassium hydroxide, and calcium hydroxide; alkali metal salts, alkaline earth metal salts, and quaternary ammonium salts of boron and aluminum hydrides such as lithium aluminum hydride, sodium borohydride, and tetramethylammonium borohydride; hydrides of alkali metals and alkaline earth metals such as lithium hydride, sodium hydride, and calcium hydride; alkoxides of alkali metals and alkaline earth metals such as lithium methoxide, sodium ethoxide, and calcium methoxide; lithium phenoxide, sodium phenoxide, magnesium phenoxide, LiO-Ar-OLi, NaO-Ar-ONa(Ar or an aryl group); alkali metal and alkaline earth metal organic acid salts such as lithium acetate, calcium acetate, and sodium benzoate; zinc compounds such as zinc oxide, zinc acetate, and zinc phenoxide; tin compounds such as tin compounds bonded to an alkoxy group or an aryloxy group, and organic tin compounds, such as boron oxide, boric acid, sodium borate, trimethyl borate, tributyl borate, triphenyl borate, tin oxide, dialkyltin oxide, dialkyltin carboxylate, tin acetate, and ethyltin tributoxide; lead compounds such as lead oxide, lead acetate, lead carbonate, basic carbonates, and alkoxides or aryloxides of lead and organic lead; and quaternary ammonium salts and quaternary phosphonium salts. When a catalyst is used, one of these catalysts may be used alone or two or more of them may be used in combination. The amount of these catalysts used is usually 10 to 10 times the amount of the aromatic dihydroxy compound used as the raw material. -10 ~1% by mass, preferably 10 -9 ~10 -1 % by mass, more preferably 10 -8 ~10-2 The range is % by mass. When aromatic polycarbonate is produced by the melt transesterification method, the polymerization catalyst used remains in the resulting aromatic polycarbonate. However, these polymerization catalysts often have adverse effects on the physical properties of the polymer. Therefore, it is preferable to reduce the amount of catalyst used as much as possible. The guide-contact flow-down polymerization apparatus constituting the aromatic polycarbonate production apparatus of this embodiment can efficiently carry out polymerization, thereby reducing the amount of catalyst used. This is also one of the advantages of the aromatic polycarbonate production apparatus of this embodiment, which can produce high-quality aromatic polycarbonate. The materials for the guided contact flow-down polymerization apparatus and piping constituting the aromatic polycarbonate production apparatus of this embodiment are not particularly limited and are typically selected from metals such as stainless steel, carbon steel, Hastelloy, nickel, titanium, chromium, and other alloys, as well as highly heat-resistant polymer materials. Furthermore, the surfaces of these materials may be subjected to various treatments as needed, such as plating, lining, passivation, acid washing, and phenol washing. Stainless steel, nickel, and glass linings are preferred, with stainless steel being particularly preferred. The discharge pump 8 for the molten prepolymer or aromatic polycarbonate is typically a gear pump capable of quantitatively discharging high-viscosity substances, but these gear pumps may be made of stainless steel or other special metals.

[0156] The aromatic polycarbonate of this embodiment has a repeating unit represented by the following formula:

[0157] [ka]

[0158] The Ar has the same structure as described above.

[0159] Particularly preferred aromatic polycarbonates are those containing 85 mol % or more of the repeating units represented by the following formula among all repeating units.

[0160] [ka]

[0161] The terminal groups of the aromatic polycarbonate of this embodiment are usually hydroxy groups or aryl carbonate groups represented by the following formula:

[0162] [ka]

[0163] In the above formula, Ar 5 has the same definition as Ar″ described above.

[0164] The ratio of hydroxy groups to aryl carbonate groups is not particularly limited, but is usually in the range of 95:5 to 5:95, preferably in the range of 90:10 to 10:90, and more preferably in the range of 80:20 to 20:80. Particularly preferred is an aromatic polycarbonate in which the proportion of phenyl carbonate groups in the terminal groups is 85 mol % or more.

[0165] According to the method for producing an aromatic polycarbonate of the present embodiment described above, an aromatic polycarbonate without variation in molecular weight can be produced stably for a long period of time.

[0166] The aromatic polycarbonate production apparatus of this embodiment may be any apparatus that satisfies the various conditions described above and has mechanical strength corresponding thereto, and may also be one to which any other device or facility having any other function necessary for continuous production operation of aromatic polycarbonate is added.

[0167] Furthermore, the aromatic polycarbonate production apparatus of this embodiment may be a combination of a plurality of the above-mentioned guide contact flow-down type polymerization apparatuses, or may be an apparatus or facility having any function other than polymerization added thereto.

[0168] When producing an aromatic polycarbonate in the aromatic polycarbonate production apparatus of this embodiment, a known catalyst deactivator as described in, for example, WO 2005 / 121213 may be used. The amount of the catalyst deactivator used is preferably 0.5 to 50 mol, more preferably 0.5 to 10 mol, and even more preferably 0.8 to 5 mol, per mol of the transesterification catalyst. The catalyst deactivator is added, for example, in an extruder connected downstream of the guided contact flow-down polymerization apparatus.

[0169] In the process of producing an aromatic polycarbonate using the aromatic polycarbonate production apparatus of the present embodiment, various additives may be added. For example, in FIGS. 6 and 7, the aromatic polycarbonate obtained in the second guide contact flow-down type polymerization apparatuses 48A and 48B is sent in a molten state from the second guide contact flow-down type polymerization apparatuses 48A and 48B to the downstream equipment 50A and 50B, where various additives may be added.

[0170] The downstream equipment 50A and 50B is not particularly limited as long as it is conventional equipment that receives molten aromatic polycarbonate, and examples thereof include an extruder, pelletizer, sieve, dryer, silo, and packaging machine. For example, molten aromatic polycarbonate may be supplied to an extruder, and in the extruder, other resins such as ABS or PET, additives such as heat stabilizers, antioxidants, light stabilizers, ultraviolet absorbers, release agents, and flame retardants, and optional additives such as organic or inorganic pigments or dyes, metal deactivators, antistatic agents, lubricants, and nucleating agents may be mixed. These other resins and optional additives may be used singly or in combination of two or more.

[0171] Furthermore, the aromatic polycarbonate produced by this embodiment may contain aliphatic dihydroxy compounds (diols) such as ethylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, and 1,10-decanediol; dicarboxylic acids such as succinic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, cyclohexanecarboxylic acid, and terephthalic acid; and oxyacids such as lactic acid, p-hydroxybenzoic acid, and 6-hydroxy-2-naphthoic acid.

[0172] As is clear from the above description, aromatic polycarbonate can be produced continuously by using the aromatic polycarbonate production apparatus of the present embodiment. The aromatic polycarbonate obtained by the method for producing an aromatic polycarbonate according to the present embodiment can be made into a molded article through a predetermined molding process. The molding step may be a known molding step, and a molded product can be obtained by molding the aromatic polycarbonate using, for example, an injection molding machine, an extrusion molding machine, a profile extruder, a blow molding machine, a sheet molding machine, a hollow sheet molding machine, or the like.

[0173] [Application] The molded article of the aromatic polycarbonate of this embodiment can be used in various applications. For example, a suitable application is a container having a housing with a capacity of 3 to 10 gallons, and the housing may have a handle formed integrally with the housing. Furthermore, the handle may have a hollow space, and the hollow space may be configured to communicate with the internal space of the housing. [Example]

[0174] The present invention will be specifically described below using specific examples and comparative examples, but the present invention is not limited to these examples and comparative examples.

[0175] The raw materials for the aromatic polycarbonates produced in the following Examples and Comparative Examples are shown below. [Raw materials] ((1) Aromatic dihydroxy compounds) BPA-1: Bisphenol A manufactured by Nippon Steel Chemical & Material Co., Ltd. ((2) Diaryl carbonate) DPC-1: Diphenyl carbonate produced by the method described in WO 2006 / 006585

[0176] The methods for measuring the physical properties and characteristics of the aromatic polycarbonates produced in the following Examples and Comparative Examples are shown below.

[0177] [Physical properties and characteristics] ((1) Number average molecular weight (Mn)) The prepolymer or pellets were measured using gel permeation chromatography (HLC-8320GPC manufactured by Tosoh Corporation, two TSK-GEL Super Multipore HZ-M tubes, RI detector) at 40°C using tetrahydrofuran as the eluent. The number average molecular weight of the prepolymer or pellet was determined using a converted molecular weight calibration curve according to the following formula from the calibration curve of standard monodisperse polystyrene (manufactured by EasiVial VARIAN). M PC =0.3591M PS 1.0388 (In the formula, M PC is the number average molecular weight of the aromatic polycarbonate, M PS indicates the number average molecular weight of polystyrene.)

[0178] ((2) Measurement of yellowness; hue) The aromatic polycarbonate pellets were dried in a hot air dryer at 120°C for 5 hours, and then continuously molded using an injection molding machine at a cylinder temperature of 300°C and a mold temperature of 90°C into test pieces measuring 50 mm in length, 90 mm in width, and 3.0 mm in thickness. The obtained test pieces were measured by a spectrophotometer (manufactured by Vista HunterLab) using a D65 light source and a viewing angle of 10° by a transmission method, and the yellowness was expressed as a b* value (CIE No. 15 (ASTM E308) standard).

[0179] ((3) Measurement of MFR) The aromatic polycarbonate pellets were dried in a hot air dryer at 120°C for 5 hours, and the MFR was measured using a melt flow tester (Mflow, manufactured by Zwick Roell) under conditions of 300°C and a load of 1.2 kg. The unit was g / 10 min (ISO1133 standard).

[0180] (4) Proportion of substance amount of branched structure (mol%) 55 mg of aromatic polycarbonate was dissolved in 2 mL of tetrahydrofuran, and then 0.5 mL of a 5N methanol solution of potassium hydroxide was added, followed by stirring at 25° C. for 2 hours to achieve complete hydrolysis. Thereafter, 0.3 mL of concentrated hydrochloric acid was added, and the ratio (mol %) of the amount of branched structures represented by the general formulas (6), (7), and (8) to the amount of repeating units represented by the general formula (5) in the aromatic polycarbonate was measured using reverse phase liquid chromatography (LC-1100, manufactured by Agilent). Reverse phase liquid chromatography was performed using an Inertsil ODS-3 column (registered trademark: manufactured by GL Sciences) and a mixed eluent consisting of methanol and 0.1% aqueous phosphoric acid solution. The column oven was set at 40°C, and the methanol / 0.1% aqueous phosphoric acid ratio was started at 20 / 80 and increased to a gradient of 100 / 0. Detection was carried out using a UV detector at a wavelength of 300 nm, and quantification was carried out based on the extinction coefficient of a standard substance.

[0181] ((5) Number of fisheyes) Aromatic polycarbonate pellets were dried in a hot air dryer at 120°C for 5 hours and then molded into a 40 μm thick, 15 cm wide film using a film inspection device (FSA100 manufactured by OCS) at a barrel temperature of 320°C, a T-die temperature of 320°C, and a roll temperature of 120°C. 2 The number of fish eyes with a size of 200 μm or more present in the sample was checked using a CCD camera.

[0182] (6) Formability of water bottles Aromatic polycarbonate pellets were dried in a hot air dryer at 120°C for 5 hours and then injection blow-molded into 5-gallon water bottles (approximately 25cm in diameter, 50cm in height, with a depression in the center of the bottle, a hollow interior approximately 5cm in diameter and 10cm in length, and a handle connected to the inside of the bottle) using an injection blow molding machine (ASB-650EXHS, manufactured by Nissei ASB) at a barrel temperature of 295°C, a mold temperature of 60°C for the core, and 30°C for the cavity.The water bottles were then evaluated for any thickness irregularities. <Uneven thickness; entire water bottle> The thickness of the entire water bottle was measured at 32 equally spaced locations along the horizontal direction (circumference) on the non-embossed parts of the water bottle body (12cm and 25cm from the bottom, excluding the handle in the center), and the (maximum thickness / minimum thickness) value on each circumference was used to evaluate the thickness variation according to the following criteria. A: Maximum thickness / minimum thickness is 1.0 to less than 1.7 B: Maximum thickness / minimum thickness is 1.7 to less than 2.5 C: Maximum thickness / minimum thickness is 2.5 to less than 4.0 D: Maximum thickness / minimum thickness is 4.0 or more or the bottle is torn <Uneven thickness; handle part> The thickness deviation of the handle was evaluated mainly at the base of the handle by visual inspection and touch according to the following criteria. A: There is almost no unevenness in the thickness. B: Some thin and thick areas are visible. C: Clearly thin and thick areas are visible. D: Too thin to maintain strength, torn, and not shaped like a handle.

[0183] (7) Impact resistance The water bottle formed in (6) above was filled with water, and the water bottle was dropped from a height of 1.5 m in four directions: upward, downward, diagonally upward, and diagonally downward, and the presence or absence of cracks was evaluated according to the following criteria. Dropping from above means dropping the water bottle with the top facing up. The downward direction means dropping the water bottle with the mouth facing downward. "Diagonally upward" means dropping the water bottle at a 45-degree angle with the mouth facing up. "Diagonally downward" means dropping the water bottle at a 45-degree angle with the mouth facing downwards. <Evaluation criteria> A: No cracks B: Cracked C: Unable to evaluate because the bottle could not be molded

[0184] Example 1 Using an aromatic polycarbonate production apparatus having the configuration shown in FIG. 6, an aromatic polycarbonate was produced as follows. In the aromatic polycarbonate production apparatus, the polymerization raw materials and the catalyst were charged into a mixing vessel 31 and mixed. Next, the mixture was transferred by a transfer pump 32 to dissolved mixture storage tanks 33A and 33B, and from there, preliminary polymerization was carried out in a first polymerization vessel 35 by means of transfer pumps 34A and 34B. Further, prepolymerization was carried out in a second polymerization vessel 37 via a discharge gear pump 36 to obtain a prepolymer of aromatic polycarbonate. The aromatic polycarbonate prepolymer was transferred via a feed pump 38 to a first inert gas absorption device 39, and the prepolymer having absorbed the inert gas as required was transferred via a feed pump 40. The pressure at which the prepolymer was supplied to the guided contact flow-down polymerization device described below was adjusted with a pressure regulating valve 41, and the prepolymer was transferred to and supplied to a first guided contact flow-down polymerization device 42, where polymerization was carried out. Phenol was discharged from a vent as a low-molecular-weight component. Although the pressure regulating valve 41 may have a valve-like structure, the structure is not limited as long as it can regulate the solubility of the inert gas. The same applies to the pressure regulating valves 47A and 47B described below. Next, the aromatic polycarbonate prepolymer was transferred via feed pump 43 to second inert gas absorption apparatus 44, and further transferred from there via three-way polymer valve 45 by feed pumps 46A and 46B. If necessary, the feed pressure of the inert gas-absorbed prepolymer to the guided contact flow-down polymerization apparatus described below was adjusted with pressure regulating valves 47A and 47B, and the prepolymer was transferred to the connected second guided contact flow-down polymerization apparatuses 48A and 48B, where polymerization was carried out. Here, phenol was discharged from a vent. Further, the mixture was transferred by supply pumps 49A and 49B, and additives were added in downstream equipment 50A and 50B to obtain the desired aromatic polycarbonate.

[0185] FIG. 2 shows a schematic diagram of the first and second inert gas absorption devices 39 and 44. The inert gas absorption devices 39 and 44 have substantially the same device configuration as the guide contact flow-down type polymerization devices 42, 48A and 48B described later, and therefore the same reference numerals are used for the common parts. In the first inert gas absorption device 39, in the inert gas absorption zone 15, which is the internal space, the upper part of the side casing 10 is cylindrical, and the bottom casing 11, which is the tapered lower part that constitutes the side casing 10, is an inverted cone, with L=500 cm, h=400 cm, D=200 cm, d=20 cm, and C=150° in Figure 2. The outer diameter of the guide 4 provided in the inert gas absorption zone 15, which is the internal space, is r=0.3 cm, and the total external surface area of ​​the guide 4 is S=60 m 2 The diameter of the holes in the perforated plate provided above the inert gas absorption zone 15, which is the internal space, is about 0.2 cm. The second inert gas absorbing device 44 has almost the same shape as the first inert gas absorbing device 39, except that the diameter of the holes in the perforated plate is about 0.6 cm.

[0186] A schematic diagram of a guided contact flow-down type polymerization apparatus is shown in Figure 3. This guided contact flow-down type polymerization apparatus has a disk-shaped flow path control component 20 with a thickness of about 2 cm and a cylindrical or pipe-shaped guide 4, as shown in Figure 4. FIG. 4 shows a schematic diagram of the upper part of the guide 4 of the guide contact flow-down type polymerization apparatus. In the guide contact flow-down type polymerization apparatus, the flow path control component 20 is suspended and fixed from above so that the distance from the upper inner wall surface 23 of the liquid supply zone 3 is about 8 cm. The distance between the inner side wall surface 22 of the liquid supply zone 3 and the flow path control member 20 is about 9 cm, and the distance between the perforated plate 2 and the flow path control member 20 is about 8 cm. The peripheral edge of this disk-shaped flow path control component 20 is designed so that the vertical cross section is a semicircle with a radius of about 1 cm, and is devised to prevent liquid from accumulating on the peripheral edge. The cross section of the connection between the inner side wall surface 22 of the liquid supply zone and the perforated plate 2 is recessed on the inside as shown in FIG. 5, and the angle E of the rising part is about 170 degrees (°). The material of this guide contact flow-down type polymerization apparatus is entirely stainless steel. The discharge pump 8 is preferably a gear pump when the concentrated liquid has a high viscosity, and is an ordinary liquid-transfer pump when the viscosity is not so high.

[0187] The guide contact flow-down type polymerization vessel 42 has a cylindrical side casing 10 and a cone-shaped bottom casing 11, and in FIG. 3, L=950 cm and h=850 cm. The inner diameter D of the side casing of the evaporation zone 5, which is the internal space, is 400 cm, the inner diameter d of the liquid outlet 7 of the cone-shaped bottom casing 11 is 20 cm, and C is 150 degrees (°). Total external surface area of ​​the entire guide 4: S = 750 m 2 is. The internal cross-sectional area A of the evaporation zone 5, which is the internal space, on the horizontal plane of the side casing 10 is 12.56 m 2 is. Furthermore, the internal cross-sectional area A and the internal cross-sectional area B (m 2) is A / B=400. Also, D / d=20. The ratio of the length L (cm) of the side casing of the evaporation zone 5 to the inner diameter D (cm) is L / D=2.375. The outer diameter r of the guide 4 is 0.3 cm. 1m of perforated plate 2 2 Average number of holes per m 2 ) N = approximately 500. The diameter of the holes in the perforated plate 2 = approximately 0.2 cm The ratio T / Q of the upper area T of the perforated plate 2 including the upper area of ​​the holes in the perforated plate 2 to the total effective cross-sectional area Q of the holes is about 1300. The distance k between the guide 4 closest to the inner wall surface of the evaporation zone 5 and said inner wall surface is about 14 cm.

[0188] The volume of space V (approximately 2.03 m) in which the liquid can exist in the liquid supply zone 3 from the liquid receiving port 1 (the junction between the receiving port and the upper inner wall of the liquid supply zone) to the upper surface of the perforated plate 2 is 3 ) and the upper area T (approximately 12.56 m) of the perforated plate 2 including the upper area of ​​the holes in the perforated plate 2. 2 ) and the value of V / T is approximately 0.162 (m). The spatial volume Y of evaporation zone 5 is approximately 135 m 3 is. The ratio Y / V of the spatial volume V in which liquid can exist in the liquid supply zone 3 from the liquid receiving port 1 to the upper surface of the perforated plate 2 to the spatial volume Y of the evaporation zone is about 67.

[0189] In Example 1, the values ​​in the aromatic polycarbonate production apparatus all satisfy the above-mentioned formulas (I) to (XV).

[0190] In the liquid supply zone 3 in FIG. 3, the liquid containing the low-boiling-point substance supplied from the liquid receiving port 1 flows between the upper surface of the flow path control component 20 and the upper inner wall surface 23 of the liquid supply zone 3, and between the inner side wall surface 22 of the liquid supply zone 3 and the flow path control component 20 in FIG. 4, mainly from the periphery toward the center of the perforated plate 2, and is uniformly distributed from the holes (21, etc.) in the perforated plate 2 to each guide 4. The guided contact flow-down polymerization apparatus is provided at its bottom with an inert gas supply port 9, and at its top with a vacuum vent port 6 (usually connected to a gas condenser and a pressure reducing device) which is an outlet for withdrawing evaporated low boiling point substances. The outside of the guided contact flow-down type polymerization apparatus is provided with a jacket or a heating pipe for a heat medium, so that a predetermined temperature can be maintained with the heat medium.

[0191] The second guide contact flow-down type polymerization apparatuses 48A and 48B have a disk-shaped flow path control component 20 with a thickness of about 2 cm and a guide 4 in the structure shown in FIG. The disk-shaped flow path control component 20 is suspended and fixed from above so that the distance from the upper inner wall surface 23 of the liquid supply zone is about 8 cm. The distance between the inner side wall surface 22 of the liquid supply zone and the flow path control member 20 is about 9 cm, and the distance between the perforated plate 2 and the flow path control member 20 is about 8 cm. The peripheral edge of this disk-shaped flow path control component 20 is designed so that the vertical cross section is a semicircle with a radius of about 1 cm, and is devised to prevent liquid from accumulating on the peripheral edge. The cross section of the connection between the inner side wall surface 22 of the liquid supply zone and the perforated plate 2 is recessed on the inside as shown in FIG. 5, and the angle E of the rising part is about 170 degrees (°). The guide contact flow-down type polymerization apparatus is made entirely of stainless steel.

[0192] A discharge pump 8 is provided at the bottom of the second guide contact flow-down type polymerization apparatus 48A, 48B, and if the concentrated liquid is not highly viscous, a gear pump is preferred, and if the viscosity is not so high, a normal liquid transfer pump is preferred. The second guide contact flow-down type polymerization apparatus has a cylindrical side casing 10 and a cone-shaped bottom casing 11 . The second guide contact flow-down type polymerization apparatus has L=1,000 cm and h=900 cm in FIG. The inner diameter of the side casing 10 of the evaporation zone 5 is D=500 cm, the inner diameter of the liquid outlet 7 of the cone-shaped bottom casing 11 is d=40 cm, and C=155 degrees. Total external surface area of ​​the entire guide 4: S = 250 m 2 is. The internal cross-sectional area A of the side casing 10 of the evaporation zone 5, which is the internal space, on the horizontal plane is 19.625 m 2 is. Furthermore, the internal cross-sectional area A and the internal cross-sectional area B (m 2 ) is A / B=156.25. Also, D / d=12.5. The ratio of the length L (cm) of the side casing 10 of the evaporation zone 5 to the inner diameter D (cm) is L / D=2. The outer diameter r of the guide 4 is 0.3 cm. 1m of perforated plate 2 2 Average number of holes per m 2 ) N = approximately 140. The diameter of the holes in the perforated plate 2 = approximately 0.4 cm The ratio T / Q of the upper area T of the perforated plate 2 including the upper area of ​​the holes in the perforated plate 2 to the total effective cross-sectional area Q of the holes is about 470. The distance k between the guide 4 closest to the inner wall surface of the evaporation zone 5 and said inner wall surface is about 15 cm.

[0193] In the liquid supply zone 3 from the liquid receiving port 1 (the junction between the receiving port and the upper inner wall of the liquid supply zone) to the upper surface of the perforated plate 2, the space volume V (approximately 3.17 m) in which the liquid can exist is 3 ) and the upper area of ​​the perforated plate including the upper area of ​​the holes T (approximately 19.63 m 2 ) and the value of V / T is approximately 0.161(m). The space volume Y of evaporation zone 5 is approximately 222.8 m 3The ratio Y / V of the spatial volume V in which liquid can exist in the liquid supply zone 3 from the liquid receiving port 1 to the upper surface of the perforated plate 2 to the spatial volume Y of the evaporation zone is approximately 70.

[0194] In Example 1, the second guide contact flow-down type polymerization apparatuses 48A and 48B in the aromatic polycarbonate production apparatus satisfy all of the above-mentioned formulas (I) to (XV).

[0195] The second guide contact flow-down type polymerization apparatuses 48A and 48B have the same structure as the first guide contact flow-down type polymerization apparatus 42 in the supply zone 3. In addition, the total external surface area S1 (m 2 ) and the total external surface area S2 (m 2 ) is S1 / S2=750 / 250=3.

[0196] The materials of the inert gas absorption device and the first and second guide contact flow-down type polymerization device are all stainless steel except for the discharge pump 8.

[0197] As shown in FIG. 6, an aromatic polycarbonate was produced using an aromatic polycarbonate production apparatus comprising two inert gas absorption apparatuses (a first inert gas absorption apparatus 39 and a second inert gas absorption apparatus 44) and two guided contact flow-down type polymerization apparatuses (a first guided contact flow-down type polymerization apparatus 42 and a second guided contact flow-down type polymerization apparatus 48A and 48B) connected in series in the order of the first inert gas absorption apparatus 39, the first guided contact flow-down type polymerization apparatus 42, the second inert gas absorption apparatus 44, and the second guided contact flow-down type polymerization apparatus (two apparatuses arranged in parallel).

[0198] Mixing tank 31 (inner capacity 120m 3 ) was charged with 40 tons of molten diphenyl carbonate (DPC-1) at 160°C. Next, potassium hydroxide was added as a catalyst in an amount of 120 mass ppb in terms of potassium content to 45 tons of bisphenol A (BPA-1), and bisphenol A was added over 1.8 hours while maintaining the temperature of the mixed liquid in the mixing tank at 100°C or higher. The amount of bisphenol A added was 44.6 tons. Next, 3.95 tons of diphenyl carbonate was additionally charged so that the molar ratio of diphenyl carbonate to bisphenol A became 1.05. The amount of diphenyl carbonate charged was weighed using a Coriolis mass weigher, and the amount of bisphenol A charged was weighed using a weighing hopper equipped with a load cell weighing device. When the temperature of the mixture reached 180°C, the dissolved mixture storage tank (120 ml capacity) 3 )33A, which took an hour to transfer.

[0199] The reaction mixture held in dissolved mixture storage tank 33A for 4 to 6 hours was filtered at a flow rate of 9 tons / hr through two polymer filters with different pore sizes (not shown; the upstream pore size was 5 μm and the downstream pore size was 2.5 μm) that were arranged in series between dissolved mixture storage tank 33A and stirred tank-type first polymerization vessel 35. The reaction mixture after filtration was heated in a preheater (not shown) and supplied to a stirred tank type first polymerization vessel 35. The liquid temperature at the outlet of the preheater was 230°C. When the level of the reaction mixture in dissolved mixture storage tank 33A fell below a predetermined value, the source of the reaction mixture supplied to stirred tank-type first polymerizer 35 was switched from dissolved mixture storage tank 33A to dissolved mixture storage tank 33B. The supply of the reaction mixture to stirred tank-type first polymerizer 35 was carried out continuously by repeatedly switching the supply source between dissolved mixture storage tanks 33A and 33B every 6.2 hours. Both the dissolved mixture storage tanks 33A and 33B were equipped with an internal coil and jacket, and maintained at 180°C.

[0200] In the first stirred tank type polymerizer 35 and the second stirred tank type polymerizer 37, stirring was carried out under reduced pressure, and the reaction mixture was polymerized while removing the generated phenol, to obtain a prepolymer. At this time, the temperature of the first stirred tank polymerizer 35 was 230°C and the pressure was 13.3 kPaA, and the temperature of the second stirred tank polymerizer 36 was 270°C and the pressure was 2.66 kPaA. The resulting molten prepolymer of aromatic polycarbonate (number average molecular weight Mn: 3,100) was continuously fed by a feed pump 38 through the liquid receiving port 1 of a first inert gas absorption device 39 to a feed zone 3 .

[0201] The prepolymer was continuously supplied to the inert gas absorption zone 15, which was the internal space, through the perforated plate 2, which was the distribution plate of the first inert gas absorption device 39, and absorbed the inert gas while flowing down along the guide 4. The inert gas absorption zone 15 , which is the internal space of the first inert gas absorption device 39 , is maintained at 180 kPaA by supplying nitrogen gas from the inert gas supply port 9 . The molten prepolymer (containing 0.04 N L of nitrogen per kg of the molten prepolymer) that fell from the bottom of guide 4 into tapered lower portion 11 of the casing of first inert gas absorption apparatus 39 was continuously discharged by discharge pump 8 (corresponding to reference symbol 40 in FIG. 6 ) so that the amount at the bottom of the apparatus remained approximately constant. With pressure control valve 41 at liquid inlet 1 of first guide contact flow-down type polymerization apparatus 42 fully opened, the pressure of the molten prepolymer entering said pressure control valve was 32 kPaA, and therefore, with the valve fully opened, the molten prepolymer was continuously supplied to liquid supply zone 3 via liquid inlet 1 of first guide contact flow-down type polymerization apparatus 42. The evaporation zone 5 , which was the internal space of the first guide contact flow-down type polymerization apparatus 42 , was maintained at a pressure of 500 PaA through a vacuum vent port 6 . The molten aromatic polycarbonate prepolymer (number average molecular weight Mn: 5,800) having an increased degree of polymerization, which had fallen from the bottom of the guide 4 into the tapered lower part 11 of the casing of the guide contact flow-down type polymerization apparatus 42, was continuously withdrawn at a constant flow rate from the liquid discharge port 7 by a discharge pump 8 (corresponding to the symbol 43 in FIG. 6) so that the amount at the bottom would be approximately constant, and was then continuously supplied to the liquid supply zone 3 of the second inert gas absorption apparatus 44.

[0202] The molten prepolymer was continuously fed through the perforated plate 2 serving as the distribution plate of the second inert gas absorption device 44 into the inert gas absorption zone 15 serving as the internal space. The molten prepolymer was allowed to flow downward along the guide 4 while absorbing the inert gas. The inert gas absorption zone 15 , which is the internal space of the second inert gas absorption device 44 , was maintained at 75 kPaA by supplying nitrogen gas from the inert gas supply port 9 . The molten prepolymer (containing 0.05 N liters of nitrogen per 1 kg of the molten prepolymer) that fell from the bottom of guide 4 into bottom casing 11, which was the tapered lower part of the casing of the second inert gas absorption apparatus, was divided into two parts (50:50) by three-way polymer valve 45 and continuously discharged at a constant rate by discharge pump 8 (corresponding to symbols 46A and 46B in Figure 6) so that the amount at the bottom would be approximately constant. The pressure control valves (47A, 47B) at the liquid receiving ports 1 of second guide contact flow-down type polymerization apparatuses 48A and 48B were fully opened, and the pressure of the molten prepolymer entering the pressure control valves was 135 kPA, and it was continuously supplied to each feed zone 3.

[0203] The molten prepolymer was continuously supplied to the evaporation zone 5, which was the internal space, through the perforated plate 2, which was the distribution plate of the second guide contact flow-down type polymerization apparatus 48A, 48B, and the polymerization reaction proceeded while flowing down along the guide 4. The evaporation zones 5, which were the internal spaces of the second guide contact flow-down type polymerization apparatuses 48A and 48B, were maintained at a pressure of 50 PaA through vacuum vent ports 6, respectively. The aromatic polycarbonate that fell from the bottom of the guide 4 into the bottom casing 11, which was the tapered lower part of the casing of the second guide contact flow-down polymerization apparatus, was continuously extracted as strands from the downstream equipment (50A, 50B) by means of a discharge pump 8 (corresponding to 49A, 49B in FIG. 6) so that the amount at the bottom would be approximately constant, and after cooling, was cut to obtain pellet-like aromatic polycarbonate. The production volume was 2.5 tons / hr for each (5.0 tons / hr in total). No additives were added. 150 hours after the start of production, pellets were collected for measurement. Each measurement and test was carried out using aromatic polycarbonate obtained from the latter device 50A. In addition, since the production conditions for the latter-stage equipment 50B were the same as those for the aromatic polycarbonate obtained by the latter-stage equipment 50A, no measurements or tests were performed. Tables 1 and 3 show the manufacturing conditions and measurement results.

[0204] Example 2 The same procedure as in Example 1 was carried out to obtain aromatic polycarbonate pellets, except that the pressure of the molten prepolymer was changed as shown in Table 1 below by operating the pressure regulating valves (41, 47A, 47B). Tables 1 and 3 show the manufacturing conditions and measurement results.

[0205] Example 3 As shown in FIG. 7, a third guide contact flow-down polymerization apparatus (48B0) ​​was connected in series with a second guide contact flow-down polymerization apparatus 48B. The third guide contact flow-down polymerization apparatus 48B0 had the same configuration as the second guide contact flow-down polymerization apparatus 48B, and no inert gas absorption device was installed between the second guide contact flow-down polymerization apparatus 48B and the third guide contact flow-down polymerization apparatus 48B0. The valve (47B0) was fully opened, and the amount of the reaction mixture fed to the stirred tank-type first polymerization vessel 35 was changed as shown in Table 1. Other conditions were the same as in Example 1, and pelletized aromatic polycarbonate was obtained. The second guide contact flow-down polymerization apparatus (48A) produced an aromatic polycarbonate with an MFR of 10, which is different from the present invention, so measurements and tests were not performed. The production volume was 4.0 tons / hr for each (8.0 tons / hr in total). Tables 1 and 3 show the manufacturing conditions and measurement results.

[0206] [Examples 4 to 6], [Comparative Examples 1 to 4] The molar ratio of DPC-1 to BPA-1, the amount of catalyst added, the amount of reaction mixture fed to the stirred tank-type first polymerization vessel 35, and the reaction temperature were changed as shown in Tables 1 and 2. Other conditions were the same as in Example 1, and aromatic polycarbonate pellets were obtained. Tables 1 to 4 show the manufacturing conditions and measurement results.

[0207] Comparative Example 5 The following polycarbonate resins were used: Novarex M7027BF (Mitsubishi Engineering Plastics Corporation) The color was not measured due to the deep blue color. The measurement results are shown in Table 5 below.

[0208] Comparative Example 6 The following polycarbonate resins were used: Panlite K-1300Y (Teijin Limited) The color was not measured due to the blue coloration. The measurement results are shown in Table 5 below.

[0209] [Table 1]

[0210] [Table 2]

[0211] [Table 3]

[0212] [Table 4]

[0213] [Table 5]

[0214] This application is based on a Japanese patent application (Patent Application No. 2021-164866) filed with the Japan Patent Office on October 6, 2021, the contents of which are incorporated herein by reference. [Industrial Applicability]

[0215] The aromatic polycarbonate of the present invention has industrial applicability in the fields of large-scale blow molding, extrusion molding, profile extrusion and hollow sheet molding, as an aromatic polycarbonate that has excellent impact resistance, few fisheyes and an excellent color while also having improved moldability, and in the field of production of the same. [Explanation of symbols]

[0216] 1 Liquid inlet 2 perforated plate 3 Liquid Supply Zone 4 Guide 5. Evaporation zone, which is the internal space 6 Vacuum vent 7 Liquid outlet 8. Discharge Pump 9 Inert gas supply port 10 Side casing 11 Bottom casing 12 Extraction port 15 Inert gas absorption zone, which is the internal space 20 Flow path control parts 21 Perforated plate hole 22 Inner sidewall of liquid supply zone 23 Upper inner wall surface of liquid supply zone 31 Mixing tank 32, 34A, 34B Transfer pump 33A,33B Dissolved mixture storage tank 35 First Polymerizer 36, 38, 40, 43, 46A, 46B, 49A, 49B, 49B0 Supply pump 37 Second Polymerizer 39 First inert gas absorption device 41, 47A, 47B Pressure regulating valve 42 First guide contact flow-down type polymerization device 44 Second inert gas absorption device 45 Three-way polymer valve 47B0 Valve 48A, 48B Second guide contact flow-down type polymerization device 48B0 Third guide contact flow-down type polymerization device 50A downstream equipment 50B downstream equipment

Claims

1. A test piece with a length of 127 mm, a width of 12.7 mm, and a thickness of 0.8 mm was stretched at a temperature of 280°C at an elongation rate of 0.005 sec. -1 The index of change in extensional viscosity measured by satisfies the following <Condition (i)> to <Condition (ii)>: The MFR measured at a temperature of 300°C and a load of 1.2 kg is 1.5 to 4.5 (g / 10 min), The polymer has a repeating unit represented by the following general formula (5) in its main chain and branched chains: The main chain and the branched chains contain one or more branched structures selected from the group consisting of branched structures represented by the following general formulas (6), (7), and (8): the ratio of the total amount of the branched structures to the amount of the repeating units represented by the following general formula (5) is 0.9 mol % to 5.0 mol %: Aromatic polycarbonate. 【Chemistry 2】 (In formulas (5), (6), (7), and (8), Ar represents a divalent aromatic residue, and Ar′ represents a trivalent aromatic residue.) <Condition (i)> An index of change in extensional viscosity in section A (the section from 0.30 seconds to 0.80 seconds after the start of extension) represented by the following formula (1): (log 10 (Extensional viscosity at 0.80 seconds [Pa s])-log 10 (Extension viscosity at 0.30 seconds [Pa s]) ÷(log) 10 0.80-log 10 0.30) Equation (1) The value of is 0.10 to 0.

30. <Condition (ii)> An index of change in extensional viscosity in section B (the section from 3.0 seconds to 8.0 seconds after the start of extension) represented by the following formula (2): (log 10 (Extensional viscosity at 8.0 seconds [Pa s])-log 10 (Extension viscosity at 3.0 seconds [Pa s]) ÷(log) 10 8.0-log 10 3.0) Equation (2) The value of is 0.70 to 1.

1.

2. The following conditions (iii) to (iv) are further satisfied: The aromatic polycarbonate according to claim 1. <Condition (iii)> An index of increase in extensional viscosity in the section from 0.30 seconds to 8.0 seconds after the start of extension, represented by the following formula (3): log 10 (Extensional viscosity at 8.0 seconds [Pa s])-log 10 (Extensional viscosity at 0.30 seconds [Pa s]) Equation (3) The value of is 0.45 to 0.

90. <Condition (iv)> An index of extensional viscosity represented by the following formula (4) at 8.0 seconds after the start of extension: log 10 (Extensional viscosity at 8.0 seconds [Pa s]) Equation (4) The value is 4.90 to 5.

40.

3. The value of the index of change in extensional viscosity represented by the formula (2) is 0.70 to 0.

85. The aromatic polycarbonate according to claim 1.

4. The value of the index of increase in extensional viscosity represented by the formula (3) is 0.45 to 0.

75. The aromatic polycarbonate according to claim 2.

5. The value of the extensional viscosity index represented by the formula (4) is 4.90 to 5.

05. The aromatic polycarbonate according to claim 2.

6. The polymer has a repeating unit represented by the following general formula (5) in its main chain and branched chains: The main chain and the branched chains contain one or more branched structures selected from the group consisting of branched structures represented by the following general formulas (6), (7), and (8): the ratio of the total amount of substances of the branched structures to the amount of substances of the repeating unit represented by the following general formula (5) is 0.9 mol % to 5.0 mol %, The aromatic polycarbonate according to claim 1, further satisfying the following <Condition (iii)> to <Condition (iv)>: 【Transformation 3】 (In formulas (5), (6), (7), and (8), Ar represents a divalent aromatic residue, and Ar′ represents a trivalent aromatic residue.) <Condition (iii)> An index of increase in extensional viscosity in the section from 0.30 seconds to 8.0 seconds after the start of extension, represented by the following formula (3): log 10 (Extensional viscosity at 8.0 seconds [Pa s])-log 10 (Extensional viscosity at 0.30 seconds [Pa s]) Equation (3) The value of is 0.45 to 0.

90. <Condition (iv)> An index of extensional viscosity represented by the following formula (4) at 8.0 seconds after the start of extension: log 10 (Extensional viscosity at 8.0 seconds [Pa s]) Equation (4) The value is 4.90 to 5.

40.

7. 7. The aromatic polycarbonate according to claim 6, wherein the value of the extensional viscosity index represented by the formula (4) is 4.90 to 5.

10.

8. A method for producing the aromatic polycarbonate according to any one of claims 1 to 7, comprising: a step of supplying the nitrogen-absorbed aromatic polycarbonate prepolymer to a guided contact flow-down polymerization apparatus constituting an aromatic polycarbonate production apparatus; allowing the prepolymer to flow down along the outer surface of a guide that does not itself have a heating source to evaporate low boiling point substances; and In a process region in which the temperature of the polymerization raw materials is 235° C. or higher in all processes of the method for producing an aromatic polycarbonate, [Equation 1] i: Process area numbers assigned in any order to multiple process areas in the manufacturing method Ti: Average temperature of the polymerization raw material in the i-th process zone (°C) Hi: Average residence time (hr) of the polymerization raw material in the i-th process zone The value K represented by is in the range of 16.5 to 25.0, A method for producing aromatic polycarbonate.

9. The evaporation of the low boiling point substance is carried out using a guided contact flow-down polymerization apparatus, The guide contact flow-down type polymerization apparatus satisfies the following <Condition (1)> to <Condition (9)>: The method for producing an aromatic polycarbonate according to claim 8. <Condition (1)> The evaporation zone has a liquid receiving port, a liquid supply zone for supplying liquid to the guides in the evaporation zone through a perforated plate, an evaporation zone in which a plurality of guides extending downward from the perforated plate are provided in a space surrounded by the perforated plate, a side casing, and a bottom casing, a vacuum vent port provided in the evaporation zone, and a liquid discharge port provided at the bottom of the bottom casing. <Condition (2)> In the liquid supply zone, a flow path control component is installed which has the function of directing the liquid supplied from the liquid receiving port to the perforated plate from the periphery toward the center of the perforated plate. <Condition (3)> The internal cross-sectional area A (m 2 ) satisfies the following formula (I): 0.7≦A≦300 Formula (I) <Condition (4)> The internal cross-sectional area A (m 2 ) and the internal cross-sectional area B (m 2 ) satisfies the following formula (II): 20≦A / B≦1000 Formula (II) <Condition (5)> The bottom casing constituting the bottom of the evaporation zone is connected to the upper side casing at an angle C degrees within the bottom casing, and the angle C (°) satisfies the following formula (III). 110≦C≦165 Formula (III) <Condition (6)> The length h (cm) of the guide satisfies formula (IV). 150≦h≦5000 Formula (IV) <Condition (7)> The total external surface area S (m 2 ) satisfies formula (V). 2≦S≦50000 Formula (V) <Condition (8)> The perforated plate 1m 2 Average number of holes per m 2 ) satisfies formula (VI). 50≦N≦3000 Formula (VI) <Condition (9)> The upper area T (m 2 ) and the total effective cross-sectional area of ​​the holes Q (m 2 ) satisfies the following formula (VII): 50≦T / Q≦3000 Formula (VII)

10. The amount of liquid used in the evaporation of the low boiling point substance is 1 ton or more per hour. A method for producing the aromatic polycarbonate according to claim 8.

11. The angle E degrees (°) between the inner side wall surface of the liquid supply zone and the perforated plate, Satisfies the following formula (VIII): The method for producing an aromatic polycarbonate according to claim 9. 100≦E<180 Formula (VIII)

12. The distance k (cm) between the guide closest to the inner wall surface of the side casing of the evaporation zone and the inner wall surface satisfies the following formula (IX): The method for producing an aromatic polycarbonate according to claim 9. 5≦k≦50 Formula (IX)

13. The side casing of the evaporation zone is cylindrical with an inner diameter D (cm) and a length L (cm), the bottom casing connected to the lower part of the side casing is cone-shaped, and the liquid outlet at the bottom of the cone-shaped bottom casing is cylindrical with an inner diameter d (cm), The D, L, and d are Satisfying the following formulas (X), (XI), (XII), and (XIII): A method for producing the aromatic polycarbonate according to claim 9. 100≦D≦1800 Formula (X) 5≦D / d≦50 Formula (XI) 0.5≦L / D≦30 Formula (XII) h-20≦L≦h+300 Formula (XIII) (In formula (XIII), h represents the length of the guide.)

14. In the liquid supply zone from the liquid receiving port to the upper surface of the perforated plate, the space volume V (m 3 ) and the upper area T (m 2 ) satisfies the following formula (XIV): The method for producing an aromatic polycarbonate according to claim 9. 0.02(m)≦V / T≦0.5(m) Formula (XIV)

15. At least one of the guides is cylindrical with an outer diameter r (cm) or a pipe-like structure that prevents liquid and / or gaseous substances from entering the inside, The outer diameter r satisfies the following formula (XV): A method for producing the aromatic polycarbonate according to claim 8. 0.1≦r≦1 Formula (XV)

16. The guide contact flow-down type polymerization apparatus has a plurality of the guides, The plurality of guides are connected by a support material. A method for producing the aromatic polycarbonate according to claim 8.

17. The plurality of guides The guide is any one selected from the group consisting of a lattice- or mesh-like guide in which each guide is fixed with a lateral support member, a three-dimensional guide in which a plurality of the lattice- or mesh-like guides are arranged in front and behind and fixed with a lateral support member, and a jungle gym-like three-dimensional guide in which each guide is fixed with a support member in the front, back, left, and right lateral directions. A method for producing the aromatic polycarbonate according to claim 8.

18. The guide contact flow-down type polymerization apparatus includes: At least one other guide-contact flow-down polymerization apparatus that satisfies the above <Condition (1)> to <Condition (9)> is further connected, The two or more guide contact flow-down polymerization apparatuses are connected in any one of series, parallel, and a combination of series and parallel; The method for producing an aromatic polycarbonate according to claim 9.

19. the guided contact flow-down polymerization apparatus is further connected to another guided contact flow-down polymerization apparatus that satisfies the <Condition (1)> to <Condition (9)>; The total external surface area S1 (m 2 )and, The total external surface area S2 (m 2 )and, but, Satisfies the following formula (XVI): A method for producing the aromatic polycarbonate according to claim 18. 1≦S1 / S2≦20 (XVI)

20. an inert gas absorbing device is provided for absorbing an inert gas into the molten aromatic polycarbonate prepolymer before it is supplied to the guide contact flow-down type polymerization apparatus; the pressure of the molten prepolymer into which the inert gas has been absorbed in a molten prepolymer supply pipe between the inert gas absorption device and the guided contact flow-down type polymerization apparatus is maintained at 15 kPaA to 200 kPaA by a pressure regulating valve installed immediately before the inlet of the guided contact flow-down type polymerization apparatus, and the molten prepolymer is supplied to the guided contact flow-down type polymerization apparatus. A method for producing the aromatic polycarbonate according to claim 9.

21. The guide contact flow-down type polymerization apparatus and the further connected guide contact flow-down type polymerization apparatus each include: an inert gas absorbing device is provided for absorbing an inert gas into the molten aromatic polycarbonate prepolymer before it is fed to each of the guide contact flow-down type polymerization apparatuses; the pressure of the molten prepolymer having the inert gas absorbed in the molten prepolymer supply pipes between the inert gas absorption device and each of the guided contact flow-down type polymerization devices is maintained at 15 kPaA to 200 kPaA by a pressure regulating valve installed immediately before the inlet of each of the guided contact flow-down type polymerization devices, and the molten prepolymer is supplied. A method for producing the aromatic polycarbonate according to claim 19.

22. A container that is a molded article of the aromatic polycarbonate according to any one of claims 1 to 7, A container having a housing portion with a storage volume of 11.4 L to 38 L.

23. The housing has a handle portion integrally formed with the housing portion.

23. The container of claim 22.

24. The handle has a hollow space, and the hollow space communicates with the internal space of the housing.

24. The container of claim 23.

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