JP2004211107A - System for manufacturing aromatic polycarbonate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a long term stable manufacturing system for high quality aromatic polycarbonates by a melting method with a high polymerization rate, excellent mechanical properties and little fluctuation in molecular weight without using a large amount of an inert gas. <P>SOLUTION: The manufacturing system for aromatic polycarbonates by a reaction of aromatic hydroxy compounds and diaryl carbonates providing fused prepolymers of the aromatic polycarbonates followed by treatment with an inert gas under a predetermined pressure to absorb the inert gas in the fused prepolymers using an absorption apparatus (1) and a polymerization vessel (10) to polymerize the inert gas-absorbed fused prepolymers. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention is directed to a system for producing an aromatic polycarbonate. More specifically, the present invention provides a method for treating a molten prepolymer of an aromatic polycarbonate obtained by reacting an aromatic dihydroxy compound with a diaryl carbonate by treating the molten prepolymer with an inert gas under a predetermined pressure. The present invention relates to a system for producing an aromatic polycarbonate, comprising: an absorption device for absorbing the inert gas; and a polymerization device for polymerizing the molten prepolymer having absorbed the inert gas.

In recent years, aromatic polycarbonates have been widely used in many fields as engineering plastics having excellent heat resistance, impact resistance, transparency, and the like. Various studies have hitherto been made on the method for producing the aromatic polycarbonate, and among them, an aromatic dihydroxy compound, for example, 2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as bisphenol A) and phosgene. Has been industrialized.

  However, in this interfacial polycondensation method, toxic phosgene must be used, the equipment is corroded by hydrogen chloride and sodium chloride by-produced and chlorine-containing compounds such as methylene chloride used in large quantities as a solvent, There have been problems such as difficulty in separating impurities such as sodium chloride, which adversely affects physical properties, and residual methylene chloride.

  On the other hand, as a method for producing an aromatic polycarbonate from an aromatic dihydroxy compound and a diaryl carbonate, for example, a melting method in which bisphenol A and diphenyl carbonate are transesterified in a molten state and polymerization is performed while extracting phenol by-produced. It has been known for some time. Unlike the interfacial polycondensation method, the melting method has the advantage of not using a solvent.On the other hand, as the polymerization progresses, the viscosity of the polymer increases, making it difficult to efficiently extract by-products such as phenol out of the system. Thus, there is an essential problem that it is difficult to increase the degree of polymerization.

  2. Description of the Related Art Conventionally, various polymerizers have been known as polymerizers for producing an aromatic polycarbonate by a melting method. The method of using a vertical stirring tank type polymerization vessel equipped with a stirrer is generally widely known. However, the vertical stirring tank type polymerization vessel has the advantage of high volumetric efficiency and simplicity on a small scale, and can efficiently proceed with polymerization, but on an industrial scale, as described above, with the progress of polymerization. There is a problem that it is difficult to efficiently extract by-product phenol to the outside of the system, and the polymerization rate becomes extremely low.

  That is, in a large-scale vertical stirring tank type polymerization vessel, the ratio of the liquid volume to the evaporation area is generally larger than that in the case of a small scale, and the so-called liquid depth is large. In this case, even if the degree of vacuum is increased to increase the degree of polymerization, since the lower part of the stirring tank has a liquid depth, the polymerization is performed at a higher pressure corresponding to the liquid depth than the upper space part. It is difficult to efficiently extract phenol and the like.

  In order to solve this problem, various devices have been devised for extracting phenol and the like from a polymer in a high viscosity state. For example, a method using a screw type polymerizer having a vent portion (see Patent Document 1), a method using an interlocking twin-screw extruder (see Patent Document 2), and a thin film evaporation type reactor such as a screw evaporator or a centrifuge A method using a thin film evaporator or the like (see Patent Document 3) is disclosed, and a method using a combination of a centrifugal thin film evaporator and a horizontal stirring polymerization tank (see Patent Document 4) is specifically disclosed. I have.

  Further, the present inventors have proposed a method using a perforated plate reactor in which the molten prepolymer is polymerized while falling freely, and a wire contact falling reactor in which the molten prepolymer is polymerized while falling along the wire. The method used was developed (for example, see Patent Document 5).

  When producing an aromatic polycarbonate by a melting method using the above-mentioned vertical stirring tank type polymerizer, intermeshing type twin screw extruder, thin film evaporation type reactor, etc., a method of performing polymerization under an inert gas atmosphere is described. Widely known. For example, in order to avoid an oxidative secondary reaction, a method of producing an aromatic polycarbonate by a transesterification method under a reduced pressure under an inert gas atmosphere (for example, see Patent Documents 6 and 7) has been proposed. A small amount of inert gas is supplied into the polymerization vessel for the aromatic polycarbonate to be produced.

On the other hand, as a method of using a large amount of an inert gas in order to extract an aromatic monohydroxy compound such as phenol generated by an equilibrium polycondensation reaction to the outside of the polymerization system, 1 m ³ or more per 1 kg of the oligocarbonate together with the oligocarbonate melt is used. A method for producing an aromatic polycarbonate by continuously introducing an inert gas into a polymerization vessel heated under normal pressure or under pressure and conveying phenol and the like by-produced in an equilibrium polycondensation reaction (see Patent Document 8) Has been proposed. However, the method of producing an aromatic polycarbonate using a large amount of an inert gas as a carrier is to separate the aromatic monohydroxy compound in the inert gas when the inert gas used for the polymerization is repeatedly used for the polymerization. And large separation equipment is required.

  In the first reaction zone for producing a low-molecular-weight polycarbonate having a viscosity-average molecular weight of 1,000 to 25,000 and the second reaction zone for producing a polycarbonate having a viscosity-average molecular weight of 10,000 to 50,000, an aromatic dihydroxy compound is added. On the other hand, there has been proposed a method of producing a polycarbonate by supplying an inert gas at a weight ratio of 0.01 to 20, and 0.002 to 10 (see Patent Document 9). In this method, too, since an inert gas is used for the purpose of distilling off the aromatic monohydroxy compound (phenol) generated by the equilibrium polycondensation reaction by transportation, the amount of the inert gas used is large and is described in Patent Document 8. The method has the same problem as the method described above.

  A method of polymerizing a prepolymer proposed by the present inventors by dropping the prepolymer from a perforated plate along a wire is described in Patent Document 10, which discloses a high-quality aromatic polycarbonate without coloring. Can be produced at a high polymerization rate, and there is also described an example in which a small amount of an inert gas is supplied into the polymerization system. The present inventors have also found that when polymerizing a prepolymer by dropping it along a guide in a space under the flow of an inert gas, the aromatic monohydroxy compound contained in the inert gas is separated from the inert gas. A method was proposed in which the range of the pressure ratio was specified and the inert gas recovery equipment was not excessive (see Patent Document 11).

  As described above, the method of efficiently extracting phenol or the like using an inert gas to produce an aromatic polycarbonate has conventionally been, in any case, continuously supplying an inert gas into a polymerization vessel, This is a method in which the polymerization is advanced by lowering the partial pressure of phenol or the like in the inside, and a large amount of inert gas is required to effectively increase the polymerization rate. In addition, the method of distilling off the aromatic monohydroxy compound generated by introducing an inert gas only into the polymerization vessel is excellent in mechanical properties and is sufficiently effective to produce an aromatic polycarbonate having a stable molecular weight. There was no way.

Japanese Patent Publication No. 50-19600 (corresponding to British Patent No. 1007302) Japanese Patent Publication No. 52-36159 Japanese Patent Publication No. 53-5718 (corresponding to U.S. Pat. No. 3,888,826) JP-A-2-153923 U.S. Pat. No. 5,589,564 U.S. Pat. No. 2,964,297 U.S. Pat. No. 3,153,008 JP-A-6-206997 (corresponding to US Pat. No. 5,384,389) JP-A-6-248067 U.S. Pat. No. 5,589,564 JP-A-8-325373

  SUMMARY OF THE INVENTION An object of the present invention is to provide an aromatic polycarbonate produced by a melting method free from problems of separation of impurities and residual methylene chloride, without using a large amount of inert gas, without coloring and having excellent mechanical properties. Provided is a very advantageous system that not only can produce a high quality aromatic polycarbonate at a high polymerization rate by an industrially preferable means, but also can stably produce a high quality aromatic polycarbonate with a small variation in molecular weight for a long period of time. It is in.

  The present inventors have conducted intensive studies on the production of aromatic polycarbonates in order to solve the various problems described above associated with the conventional method of using an inert gas for the melt polymerization method. As a result, surprisingly, when producing an aromatic polycarbonate by a melting method, a large amount of inert gas is provided by providing an inert gas absorption step of absorbing a small amount of inert gas into the molten prepolymer before the polymerization step. Even without using an active gas, not only can a high-quality aromatic polycarbonate having excellent mechanical properties without coloring be produced at a high polymerization rate, but also the dispersion of the molecular weight of the obtained aromatic polycarbonate is small, The present inventors have found that a high-quality aromatic polycarbonate can be stably produced for a long period of time, and have completed the present invention.

According to the present invention, there is provided a system for producing an aromatic polycarbonate from an aromatic dihydroxy compound and a diaryl carbonate,
(A) treating the molten prepolymer of aromatic polycarbonate obtained by reacting an aromatic dihydroxy compound with a diaryl carbonate with an inert gas at a predetermined pressure under an inert gas. Absorbing device to absorb,
(B) a polymerization vessel for polymerizing the molten prepolymer having absorbed the inert gas;
There is provided a system for producing an aromatic polycarbonate, comprising:

Next, in order to facilitate understanding of the present invention, first, basic features and preferred embodiments of the present invention will be listed.
(1) An inert gas absorption device (1) for absorbing an inert gas into a molten prepolymer of an aromatic polycarbonate obtained by reacting an aromatic dihydroxy compound with a diaryl carbonate; A polymerization reactor (10) having a polymerization reaction zone for polymerizing the prepolymer, and the molten prepolymer having absorbed the inert gas is supplied from the inert gas absorption device (1) to the polymerization reactor (10) at a predetermined flow rate. A melt prepolymer discharge pump (9) for feeding, and a discharge pump (18) for discharging the aromatic polycarbonate obtained in the polymerizer (10), and the inert gas absorbing device ( 1), the molten prepolymer discharge pump (9), the polymerizer (10), and the aromatic polycarbonate discharge pump (18) are arranged in this order. System for producing an aromatic polycarbonate, characterized in that formed by bound.

(2) The inert gas absorbing device (1) includes a molten prepolymer supply port for the aromatic polycarbonate, an inert gas supply port, and a molten prepolymer that has absorbed the inert gas by absorbing the inert gas into the molten prepolymer. An inert gas absorption zone for obtaining a polymer, and an outlet for the molten prepolymer having absorbed the inert gas, wherein the polymerization vessel (10) is provided with the inert gas-absorbed molten prepolymer. A supply port, a supply zone of the molten prepolymer absorbing an inert gas for supplying the molten prepolymer to the polymerization reaction zone, a polymerization reaction zone, a vacuum vent provided in the polymerization reaction zone, and an aromatic polycarbonate outlet And the aromatic polycarbonate discharge pump (18) is provided at a predetermined flow rate from the discharge port of the polymerization vessel (10). System for producing an aromatic polycarbonate of (1), which is a pump capable of extracting the bets.

(3) a polymerization reaction zone of the polymerizer (10) for polymerizing the molten prepolymer having absorbed the inert gas includes at least one guide fixed and extending downward in the polymerizer (10); A guide contact drop polymerization reaction zone, wherein the guide contact drop polymerization reaction zone is separated by a molten prepolymer supply zone absorbing an inert gas and a molten prepolymer distribution plate having at least one hole, The molten prepolymer supply zone communicates with the guide contact drop polymerization reaction zone through the hole of the distribution plate, and the guide is disposed corresponding to the hole of the distribution plate. A system for producing the aromatic polycarbonate according to the above (1) or (2).

(4) The system for producing an aromatic polycarbonate according to any one of (1) to (3), wherein the polymerization reactor (10) is a wire contact falling polymerization reactor.
(5) The system for producing an aromatic polycarbonate according to the above (3), wherein the guide has a cylindrical shape.
(6) The system for producing an aromatic polycarbonate according to the above (3), wherein the guide is a wire mesh.
(7) The system for producing an aromatic polycarbonate according to (3), wherein the guide is in the form of a punching plate.

The methods described below are also preferred embodiments for implementing the system of the present invention.
[1] In producing an aromatic polycarbonate by reacting an aromatic dihydroxy compound with a diaryl carbonate,
By treatment with an inert gas under a predetermined pressure P _g in (a) an aromatic dihydroxy compound inert gas absorption device molten prepolymer of an aromatic polycarbonate obtained by reacting diaryl carbonate (1) Allowing the molten prepolymer to absorb the inert gas,
The (b) the molten prepolymer having absorbed inert gas, subjected to polymerization under low pressure P _p than inert gas absorption step (a), the polymerizing the molten prepolymer to a predetermined degree of polymerization And that
(C) said predetermined pressure P _g employed in the inert gas absorption step (a), the production method of an aromatic polycarbonate, characterized in that it is the molten prepolymer reaction pressure than that used to obtain.

[2] The method according to the above [1], wherein the molecular weight change of the molten prepolymer before and after the inert gas absorption step (a) is represented by the following formula.
(M ₂ −M ₁ ) ≦ 500
(However, in the above formula, M ₁ and M ₂ respectively represent the number average molecular weight of the molten prepolymer before and after the inert gas absorption step (a).)

[3] the predetermined pressure P _g employed in the inert gas absorption step (a), method of [1] or [2], which satisfies the following formula (1).
P _g > 4 × 10 ¹² × M ₁ ^-2.66871 (1)
(Where, in equation (1), P _g represents the pressure (Pa) used in the inert gas absorption step (a); and M ₁ is the molten prepolymer before the inert gas absorption step (a). Represents the number average molecular weight.)

[4] When _{M 2} is less than 5,178, the pressure _{P p} employed in the polymerization step (b) satisfies the following formula (2), when _{M 2} is 5,178 or more, used in the polymerization step (b) the method according to the above [1] to [3], the pressure _{P p} is characterized by satisfying the following formula (3).
_{P g> P p> -0.056 ×} M 2 + 290 (2)
(Where, in the formula (2), P _g and P _p represent the pressure (Pa) used in the inert gas absorption step (a) and the polymerization step (b), respectively; and M ₂ represents the inert gas absorption step. Represents the number average molecular weight of the molten prepolymer after step (a).)
_Pg > _Pp > 0 (3)
(However, in the formula (3), P _g and P _p are as defined for the above formula (2).)

[5] The polymerization step (b) is carried out by a guide contact drop polymerization process in which the molten prepolymer is caused to flow down along the surface of the guide and the polymerization of the molten prepolymer is performed during the falling. 1] to [4].
[6] The method according to the above [5], wherein in the polymerization step (b), the molten prepolymer flowing down along the guide is always in a foamed state.
[7] The molten prepolymer having absorbed the inert gas is continuously supplied to a polymerization zone for performing the polymerization of the molten prepolymer in the polymerization step (b), and is produced in the polymerization step (b). The method according to any of [1] to [6], wherein the aromatic polycarbonate is continuously withdrawn from the polymerization zone, and the polymerization step (b) is continuously performed.
[8] The method according to any one of [1] to [7], wherein the inert gas is nitrogen.
[9] The inert gas absorption amount in the inert gas absorption step (a) is 0.0001 to 1 Nl per 1 kg of the molten prepolymer (where N1 is 1 (liter) measured under standard temperature and pressure conditions. The method according to any one of the above [1] to [8], wherein

The system of the present invention has various problems existing in the aromatic polycarbonate production process by the phosgene method (for example, using a large amount of highly toxic phosgene, using a large amount of methylene chloride as a solvent, by-products). Corrosion of equipment due to hydrogen chloride, sodium chloride, and chlorine-containing compounds such as methylene chloride, and difficulties in separating impurities such as sodium chloride and residual methylene chloride, which adversely affect the physical properties of polymers, etc.) The problems existing in the conventional melt transesterification process (for example, as the polymerization proceeds, the viscosity of the polymer increases, making it difficult to efficiently extract by-product phenol and the like to the outside of the system. Intrinsic problem that it is difficult to raise, trying to effectively increase the polymerization rate by introducing an inert gas into the polymerization vessel If a large amount of inert gas is required, the equipment for separating and recovering the inert gas and by-product phenol, etc. must be large, and the inert gas is introduced only into the polymerization reactor to remove by-product phenol, etc. The method of entrainment distillation is to solve the problem that it is not a method that has excellent mechanical properties and is not sufficiently effective for producing an aromatic polycarbonate having a stable molecular weight.
That is, according to the system of the present invention, it is possible to produce a high-quality aromatic polycarbonate having excellent mechanical properties without coloring, at a high polymerization rate, without using a large amount of inert gas, and with a high molecular weight. And the aromatic polycarbonate can be stably produced for a long period of time. Therefore, the present invention is a system having an industrially excellent effect.

The above and other objects, features and advantages of the present invention will be apparent from the detailed description and the appended claims, which refer to the accompanying drawings.
Hereinafter, the present invention will be described in detail.

  Conventionally, a method of efficiently extracting an aromatic monohydroxy compound such as phenol using an inert gas to produce an aromatic polycarbonate is a method of supplying an inert gas into a polymerization vessel in any case. However, surprisingly, in an inert gas absorbing step, an inert gas is absorbed by a molten prepolymer, and the obtained molten prepolymer absorbing the inert gas is polymerized (Japanese Patent Application No. 2000-553493). According to the method of the present invention, it has become clear that there is no inert gas absorption step and the polymerization rate can be remarkably increased as compared with the conventional method of supplying an inert gas into the polymerization vessel.

  The reason that the polymerization rate is increased by continuously supplying and flowing the inert gas into the polymerization vessel is that since the polymerization reaction is an equilibrium reaction, phenol by-produced is removed accompanying the inert gas. It is understood that this is because the phenol partial pressure in the polymerization vessel decreases, and the polymerization can proceed advantageously in an equilibrium manner. In such a case, in the conventional method, in order to increase the polymerization rate, the supply amount of the inert gas must be increased, and various problems associated with the use of a large amount of the inert gas can be avoided. There was no difficulty.

  However, the method of the present invention made it possible to surprisingly reduce the amount of inert gas supplied and increase the polymerization rate. That is, in the invention of the original application, the polymerization rate is increased only by the fact that a small amount of inert gas that hardly lowers the phenol partial pressure is absorbed by the molten prepolymer. This cannot be explained from the conventionally known mechanism of action of the inert gas.

  However, according to the study by the present inventors, surprisingly, when the molten prepolymer having absorbed the inert gas in the inert gas absorbing step is polymerized, the molten prepolymer is continuously polymerized in the polymerization vessel. It has been observed that a strong foaming phenomenon occurs violently, and the stirring state of the molten prepolymer becomes extremely good.It is presumed that a change in the internal and surface state of the molten prepolymer causes a rise in the polymerization rate. You.

  In addition, compared to the method of introducing an inert gas into the polymerization vessel to efficiently extract phenol, the method of the present invention, in which the inert gas is absorbed in advance, is surprisingly aromatic polycarbonate. Has excellent mechanical strength, very small variation in molecular weight, and can be stably produced for a long period of time. Although the reason for this is not clear, if the inert gas is absorbed into the molten prepolymer by an inert gas absorbing device, the inert gas is uniformly dissolved, so that the molten prepolymer in the polymerization vessel is dissolved. It is considered that the foaming state is also more uniform than in the conventional method, so that the mechanical properties are improved and the variation in the molecular weight is reduced. In this way, various problems that could not be avoided in the conventional method of polymerizing a molten prepolymer of an aromatic polycarbonate while introducing an inert gas were solved at once.

  As described above, the present invention can not only produce a high-quality aromatic polycarbonate having excellent mechanical properties without coloring at a high polymerization rate, but also have a small variation in the molecular weight of the obtained aromatic polycarbonate and a long length. It is an object of the present invention to provide a system for realizing the method described in the invention of the original application, which can stably produce a high-quality aromatic polycarbonate for a long period of time.

Hereinafter, the present invention will be described in detail.
In the present invention, the aromatic dihydroxy compound is a compound represented by the following formula.
HO-Ar-OH
(In the formula, Ar represents a divalent aromatic group.)
Here, the divalent aromatic group Ar is preferably, for example, one represented by the following formula.
-Ar ¹ -Y-Ar ^2-
(Wherein, Ar ¹ and Ar ² each independently represent a divalent carbocyclic or heterocyclic aromatic group having 5 to 70 carbon atoms, and Y represents a divalent having 1 to 30 carbon atoms. Represents an alkane group.)

In the divalent aromatic groups Ar ¹ and Ar ² , at least one hydrogen atom has another substituent that does not adversely influence the reaction, for example, a halogen atom, an alkyl group having 1 to 10 carbon atoms, and 1 to 1 carbon atoms. They may be substituted by 10 alkoxy groups, phenyl groups, phenoxy groups, vinyl groups, cyano groups, ester groups, amide groups, nitro groups, and the like. Preferred specific examples of the heterocyclic aromatic group include an aromatic group having one or more ring-forming nitrogen, oxygen or sulfur atoms. The divalent aromatic groups Ar ¹ and Ar ² represent groups such as substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene, and substituted or unsubstituted pyridylene. The substituent here is as described above.
The divalent alkane group Y is, for example, an organic group represented by the following formula 1.

(Wherein, R ¹ , R ² , R ³ , and R ⁴ are each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and cycloalkyl having 5 to 10 ring carbon atoms) A carbocyclic aromatic group having 5 to 10 carbon atoms and a carbocyclic aralkyl group having 6 to 10 carbon atoms, k represents an integer of 3 to 11, and R ⁵ and R ⁶ are each X And each independently represents hydrogen or an alkyl group having 1 to 6 carbon atoms, X represents carbon, and R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ Other substituents, for example, 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, and a vinyl group as long as one or more hydrogen atoms do not adversely affect the reaction. Group, cyano group, ester group, amide group, nitro group, etc. Or it may be substituted.)
Examples of such a divalent aromatic group Ar include those represented by the following chemical formula 2.

(Wherein, R ⁷ and R ⁸ each independently represent 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, and when m is 2 to 4, each R ⁷ may be the same or different, and when n is 2 to 4, In the formula, each R ⁸ may be the same or different.)
Further, the divalent aromatic group Ar may be represented by the following formula.
-Ar ¹ -Z-Ar ^2-
(Wherein, Ar ¹ and Ar ² are as described above, and Z is a single bond or —O—, —CO—, —S—, —SO ₂ —, —SO—, —COO—, —CON (R ¹ )-Represents a divalent group, provided that R ¹ is as described above.)
Examples of such a divalent aromatic group Ar include those represented by the following chemical formula 3.

(In the formula, R ⁷ , R ⁸ , m and n are as described above.)
Further, specific examples of the divalent aromatic group Ar include substituted or unsubstituted phenylene, substituted or unsubstituted naphthylene, and substituted or unsubstituted pyridylene.
The aromatic dihydroxy compound used in the present invention may be a single kind or two or more kinds. A typical example of the aromatic dihydroxy compound is bisphenol A. Further, in the present invention, a trivalent aromatic trihydroxy compound for introducing a branched structure may be used in combination as long as the object of the present invention is not impaired.
The diaryl carbonate used in the present invention is represented by the following chemical formula 4.

(In the formula, Ar ³ and Ar ⁴ each represent a monovalent aromatic group.)
Ar ³ and Ar ⁴ represent a monovalent carbocyclic or heterocyclic aromatic group, wherein one or more hydrogen atoms in Ar ³ or Ar ⁴ are other substituents which do not adversely influence the reaction. For example, those substituted with 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, a nitro group, etc. It may be. Ar ³ and Ar ⁴ may be the same or different. Representative examples of the monovalent aromatic groups Ar ³ and Ar ⁴ include a phenyl group, a naphthyl group, a biphenyl group, and a pyridyl group. These may be substituted with one or more substituents described above.
Preferred examples of Ar ³ and Ar ⁴ include, for example, those shown in Chemical Formula 5 below.

  Representative examples of the diaryl carbonate include substituted or unsubstituted diphenyl carbonates represented by the following formula (6).

(Wherein 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 phenyl And p and q are integers of 1 to 5, and when p is 2 or more, each R ⁹ may be different, and when q is 2 or more, each R ⁹ May be different from each other.)

  Among these diaryl carbonates, symmetric diaryl carbonates such as unsubstituted diphenyl carbonate, lower alkyl-substituted diphenyl carbonates such as ditolyl carbonate and di-t-butylphenyl carbonate are preferred, and diaryl having the simplest structure is particularly preferred. Diphenyl carbonate, which is a carbonate, is preferred. These diaryl carbonates may be used alone or in combination of two or more.

  The use ratio (preparation ratio) of the aromatic dihydroxy compound and the diaryl carbonate varies depending on the type of the aromatic dihydroxy compound and the diaryl carbonate used, the polymerization temperature and other polymerization conditions. On the other hand, it is used in a proportion of usually 0.9 to 2.5 mol, preferably 0.95 to 2.0 mol, more preferably 0.98 to 1.5 mol.

  In the present invention, the prepolymer in a molten state produced from an aromatic dihydroxy compound and a diaryl carbonate (hereinafter, referred to as a molten prepolymer) is a target degree of polymerization produced from an aromatic dihydroxy compound and a diaryl carbonate. Means a melt in the course of polymerization having a lower degree of polymerization than the aromatic polycarbonate having the above, and may of course be an oligomer.

  The inert gas referred to in the present invention is a generic name of a gas that does not cause a chemical reaction with the molten prepolymer and is stable under polymerization conditions. Specific examples of the inert gas include nitrogen, argon, helium, and dioxide. Examples thereof include carbon, an organic compound which is gaseous at a temperature at which the prepolymer maintains a molten state, and a lower hydrocarbon gas having 1 to 8 carbon atoms. Nitrogen is particularly preferred.

An outline of the system of the present invention will be described with reference to FIG.
The system of the present invention comprises an inert gas absorption device (1) for absorbing an inert gas into a molten prepolymer of an aromatic polycarbonate obtained by reacting an aromatic dihydroxy compound with a diaryl carbonate, and absorbing the inert gas. A polymerization reactor (10) having a polymerization reaction zone for polymerizing the molten prepolymer, and a molten prepolymer for supplying the molten prepolymer having absorbed the inert gas to the polymerization reactor (10) at a predetermined flow rate. A discharge pump (9), a discharge pump (18) for discharging the obtained aromatic polycarbonate, and the inert gas absorbing device (1), the molten prepolymer discharge pump (9), The polymerization vessel (10) and the aromatic polycarbonate discharge pump (18) are characterized by being connected in this order. .

  The inert gas absorbing device (1) used in the present invention has a molten aromatic polycarbonate prepolymer supply port (2), an inert gas supply port (5), and an inert gas absorbed by the molten prepolymer. It is preferable to have an inert gas absorption zone for obtaining a molten prepolymer that has absorbed the active gas, and an outlet (8) for the molten prepolymer that has absorbed the inert gas.

  The polymerization vessel (10) used in the present invention has a molten prepolymer supply port (11) for absorbing an inert gas and a molten prepolymer for absorbing the inert gas for supplying the molten prepolymer to a polymerization reaction zone. It is preferable to have a polymer supply zone, a polymerization reaction zone, a vacuum vent (15) provided in the polymerization reaction zone, and an aromatic polycarbonate outlet (17). Further, the polymerization reactor (10) used in the present invention is preferably a wire contact falling polymerization reactor.

  In the system of the present invention, the molten prepolymer (7) having absorbed the inert gas is withdrawn from the inert gas absorbing device (1) through the molten prepolymer outlet (8), and is discharged from the discharge pump (9). ) And into the polymerization reactor (10) through the molten prepolymer supply port (11), through the molten prepolymer supply zone and into the polymerization reaction zone under reduced pressure through the vacuum vent port (15). Then, an aromatic polycarbonate (16) is obtained by polymerization, and the obtained aromatic polycarbonate (16) is discharged from the aromatic polycarbonate discharge pump (18) through the outlet of the polymerization device (10). It is preferable that it is comprised.

  In practicing the system of the present invention, the molten prepolymer is treated with an inert gas under a predetermined pressure, and the molten prepolymer is allowed to absorb the inert gas under conditions where the prepolymer is difficult to polymerize. The inert gas absorbing step (a) is performed using the inert gas absorbing device (1). Absorbing the inert gas in the molten prepolymer means dispersing and / or dissolving the inert gas in the molten prepolymer. Dispersion means a state in which an inert gas is mixed in a bubble state in a molten prepolymer and forms a gas-liquid mixed phase.Dissolution means that the inert gas is mixed with the molten prepolymer and a uniform liquid is formed. It means a state where a phase is formed. It is particularly preferred that the inert gas not only be dispersed but also dissolved in the molten prepolymer. In order to efficiently dissolve the inert gas in the molten prepolymer, it is preferable to increase the area of the gas-liquid interface to improve the contact efficiency, or to carry out the process under the pressure of the inert gas.

  The type of the inert gas absorbing device (1) used in the present invention is not particularly limited as long as it is a device capable of absorbing the inert gas into the molten prepolymer. No. 2. Packed tower type absorber, shelf type absorber, spray tower type absorber, fluidized packed column type absorber described in Revised Gas Absorption 49-54 (March 15, 1981, published by Chemical Industry Co., Ltd.) A known device such as a liquid film cross-flow absorption type absorption device, a high-speed swirling flow type absorption device, or a mechanical force type absorption device, or absorbing the molten prepolymer while falling along a guide in an inert gas atmosphere. And the like. A device for directly supplying and absorbing an inert gas into a pipe for supplying a molten prepolymer to a polymerization vessel may be used. It is a particularly preferable method to use a spray tower type absorption device or a device that absorbs while falling along a guide.

  The inert gas absorbing device (1) may be the same type of device as that usually used as a polymerization vessel, but it is operated under conditions that hardly allow polymerization to proceed, so that it is functionally completely different from the polymerization vessel. It is.

When the number average molecular weights of the molten prepolymer before and after the inert gas absorption step (a) are M ₁ and M ₂ , respectively, the molecular weight change (M ₂ −M ₁ ) in the inert gas absorption step is substantially 1, It is preferably less than 000, more preferably 500 or less. When (M ₂ −M ₁ ) is larger than 500, the effect of increasing the polymerization rate is reduced even if the molten prepolymer having absorbed the inert gas is supplied to the polymerization vessel. Although the reason for this is not clear, when (M ₂ −M ₁ ) is larger than 500, it is estimated that the aromatic monohydroxy compound generated when the polymerization proceeds prevents the absorption of the inert gas. You. (M ₂ −M ₁ ) is more preferably 400 or less, and further preferably 300 or less.
The temperature of the inert gas absorption step (a) is not particularly limited, and is usually 150 to 350 ° C, preferably 180 to 300 ° C, and particularly preferably 230 to 290 ° C.

In practicing the system of the present invention, the predetermined pressure P _g (Pa) used in the inert gas absorption step (a) is used to obtain a molten prepolymer to be treated in the inert gas absorption step (a). The pressure is preferably equal to or higher than the pressure. That is, the inert gas absorbing step (a) is carried out under the same or higher reaction pressure as that used for producing a molten prepolymer of an aromatic polycarbonate by reacting an aromatic dihydroxy compound with a diaryl carbonate. Is preferably performed. The predetermined pressure P _g (Pa) used in the inert gas absorption step (a) is higher than the reaction pressure used to obtain the molten prepolymer to be treated in the inert gas absorption step (a). preferable.

Further, the pressure P _g (Pa) in the inert gas absorption step is a predetermined pressure higher than the pressure P _p (Pa) in the subsequent polymerization step (b), but is M ₁ (as defined above). In contrast, the following equation (1)
P _g > 4 × 10 ¹² × M ₁ ^-2.66871 (1)
Is preferably satisfied.

When the pressure P _g (Pa) in the inert gas absorption step does not satisfy the relationship of the expression (1), the effect of increasing the polymerization rate is reduced. It is particularly preferable that the pressure in the inert gas absorbing step be normal pressure or pressurized, because the rate of absorption of the inert gas into the molten prepolymer can be increased, and as a result, the absorption device can be reduced. The upper limit of the pressure in the inert gas absorption step is not particularly limited, but is usually 2 × 10 ⁷ Pa or less, preferably 1 × 10 ⁷ Pa or less, more preferably 5 × 10 ⁶ Pa or less. Allow absorption.

  As a method of causing the molten prepolymer to absorb the inert gas with the inert gas absorbing device (1), a method of absorbing most of the inert gas supplied to the inert gas absorbing step into the molten prepolymer may be used, A method of absorbing a part of the supplied inert gas into the molten prepolymer may be used.

  As the former method, for example, a spray tower type absorption device or a device for absorbing while dropping along a guide is used to supply an inert gas in an amount substantially equal to the inert gas absorbed in the molten prepolymer. And a method in which an inert gas is directly supplied into a pipe for supplying a molten prepolymer to a polymerization vessel (10).

As the latter method, for example, a spray tower type absorption device or a device for absorbing the molten prepolymer while dropping it along a guide is used as an inert gas absorption device, and the molten prepolymer is absorbed in the molten prepolymer in the absorption device. Or more, and an excess of the inert gas is discharged from the inert gas absorbing device.
The former method is particularly preferable from the viewpoint of reducing the amount of the inert gas used.

  In addition, the inert gas absorbing step is a continuous method in which the molten prepolymer is continuously supplied to the absorbing device (1) to absorb the inert gas, and the molten prepolymer that has absorbed the inert gas is continuously extracted. Any of the batch methods in which the molten prepolymer is charged into the apparatus (1) in a batch manner and the inert gas is absorbed can be used.

  When absorbing the inert gas into the molten prepolymer, the amount of the inert gas absorbed into the molten prepolymer is not particularly limited, but is usually in the range of 0.0001 to 1 Nl per 1 kg of the molten prepolymer. , Preferably in the range of 0.001 to 0.8 Nl, and more preferably in the range of 0.005 to 0.6 Nl. "Nl" means liter measured under standard temperature and pressure conditions. If the amount of the inert gas absorbed is less than 0.0001 Nl per 1 kg of the molten prepolymer, the effect of increasing the polymerization rate is undesirably reduced. Further, in the present invention, the amount of the inert gas absorbed need not be more than 1 Nl per 1 kg of the molten prepolymer.

  The amount of the inert gas absorbed by the molten polymer can usually be easily measured by directly measuring the amount of the supplied inert gas. When the molten prepolymer is to be absorbed while flowing the inert gas through the absorption device (1), the amount of the absorbed inert gas is determined from the difference between the supplied inert gas amount and the discharged inert gas amount. be able to. It also supplies a predetermined amount of molten prepolymer to an absorption device (1) charged with an inert gas at a predetermined pressure, and adjusts the pressure of the absorption device (1) caused by the absorption of the inert gas into the molten prepolymer. It is also possible to measure from the amount of decrease. Furthermore, it is possible to use a batch method in which a predetermined amount of the molten prepolymer is supplied to the absorber in batches and then the amount of inert gas absorbed is measured, or the molten prepolymer is continuously supplied to the absorber (1). However, a continuous method in which the amount of inert gas absorbed is measured while continuously extracting the gas is also possible.

In practicing the system of the present invention, in order to polymerize the molten prepolymer having absorbed the inert gas using the inert gas absorbing device (1), a polymerization reactor (10) having a polymerization reaction zone is provided. And a polymerization step for further increasing the degree of polymerization (preferably increasing Mn by 1,000 or more) by performing polymerization under a pressure (P _p ) lower than the pressure (P _g ) in the inert gas absorption step. (B) is performed.

In the polymerization process of the present invention (b), when the number average molecular weight of the molten prepolymer after the inert gas absorption step (a) _{M 2} is less than 5,178, the pressure _P p of the polymerization step (Pa) satisfy the following Equation (2)
P _g > P _p > −0.056 × M ₂ +290 (2)
When M ₂ is 5,178 or more, the pressure P _p (Pa) in the polymerization step is determined by the following formula (3).
_Pg > _Pp > 0 (3)
It is particularly preferable to satisfy the following relationship.

When _Pp is equal to or greater than _Pg , polymerization hardly proceeds. If M ₂ is less than 5,178, in the case of _{P p} is (-0.056 × _M 2 +290) or less, the polymerization rate is very low. Generally, when a polycarbonate is produced by a transesterification reaction, it is known that the lower the pressure in the polymerization step, the easier it is to extract phenol by-produced out of the system, and the higher the polymerization rate.

However, when polymerizing a molten prepolymer that has absorbed an inert gas as in the present invention, it is surprising that a specific pressure [(−0) as a function of the number average molecular weight (M ₂ ) of the prepolymer is obtained. 0.056 × M ₂ +290) Pa] was found to be disadvantageous in terms of polymerization rate. Although the reason for this is not clear, when the pressure of the polymerization step is lower than a specific value, the molten prepolymer containing the inert gas is introduced into the polymerization reactor (10) immediately after the molten prepolymer is introduced. It is presumed that this is because the inert gas rapidly scatters and does not form a continuous foaming state of the prepolymer due to the inert gas.

The addition (2), the lower limit of the pressure of the higher polymerization step M ₂ is increased is low, the molecular weight of the molten prepolymer having absorbed inert gas becomes high, the inert gas for the melt viscosity to increase pre It is considered that this is because it is difficult to scatter from the polymer. If M ₂ is 5,178 or more molten prepolymer Therefore, it was found that the rate of polymerization by going to lower the polymerization pressure is gradually increased.

  In the present invention, if the inert gas is absorbed by the molten prepolymer in the inert gas absorption step (a), it is not necessary to supply the inert gas directly into the polymerization vessel (10), but it may be additionally supplied. . However, if the inert gas is not directly absorbed into the polymerization reactor (10) without absorbing the inert gas into the molten prepolymer in the inert gas absorbing step, the system of the present invention can be used as compared with the method of implementing the system of the present invention. In addition, the polymerization rate is remarkably slowed down, and the mechanical properties of the obtained aromatic polycarbonate, particularly the tensile elongation, are lowered, so that the object of the present invention cannot be achieved.

  In contrast, the method of implementing the system of the present invention results in a polymer having high mechanical properties, especially high tensile elongation. Although the reason for this is not clear, the inert gas is polymerized into the molten prepolymer by the inert gas absorbing device (1) as compared with the case where the inert gas is directly supplied while polymerizing the polymer in the polymerizer (10). When absorbed under difficult conditions, the inert gas is uniformly dissolved in the molten polymer, so that the foamed state of the molten prepolymer in the polymerization vessel (10) becomes more uniform, and the mechanical properties are also reduced. It is believed that an improved and stable molecular weight polymer can be produced.

  Also, compared with the case where the inert gas is not supplied directly to the polymerization reactor without absorbing the inert gas into the molten prepolymer in the inert gas absorption step, the method of implementing the system of the present invention is surprising. What is necessary is that the variation in the molecular weight of the aromatic polycarbonate to be produced becomes extremely small. It is not clear why this is the case, but as well as the improvement in the mechanical properties, the uniform dissolution of the inert gas makes the foamed state of the molten prepolymer in the polymerization vessel more uniform, which suggests that the variation in molecular weight. It is presumed that this is a factor that reduces

  In the method of practicing the system of the present invention, in producing the prepolymer and the aromatic polycarbonate by reacting the aromatic dihydroxy compound with the diaryl carbonate, the reaction temperature is usually 50 to 350 ° C, preferably 100 to 300 ° C. Is selected in the range.

  The method for carrying out the system for producing an aromatic polycarbonate of the present invention comprises a transesterification reaction between an aromatic dihydroxy compound and a diaryl carbonate as described above in the molten state with heating in the presence or absence of a catalyst. And there are no particular restrictions on the apparatus for producing the prepolymer and the polymerization vessel (10) used in the polymerization step (b).

  For example, a stirred tank reactor, a thin film reactor, a centrifugal thin film evaporation reactor, a surface-renewal twin-screw kneading reactor, a twin-screw horizontal stirring reactor, a wet-wall reactor, and a perforated plate type for free-fall polymerization A polymerization vessel which melts and drops the prepolymer along the guide and guides the polymerization to proceed with the polymerization, for example, a wire-contact flow-down polymerization vessel or the like, is used alone or in combination.

  For example, at the beginning of the polymerization, a molten prepolymer is produced from an aromatic dihydroxy compound and a diaryl carbonate by using a vertical stirring tank, and in the polymerization step (b), a surface-renewed twin-screw kneading reactor and a twin-screw horizontal stirrer are used. The method of polymerizing using a reactor, a wet wall type reactor, a perforated plate type reactor in which polymerization is carried out while free falling, a polymerization reactor in which a prepolymer is melted and dropped along a guide and the polymerization proceeds, and the like are described in the present invention. This is one of the preferred embodiments when implementing the system of the above.

  A particularly preferred polymerization vessel (10) used in the polymerization step (b) is a polymerization vessel in which a prepolymer is melted and dropped along a guide to progress polymerization (for example, see Patent Document 10). In the polymerization reactor in which the prepolymer is melted and dropped along the guide to progress the polymerization, the prepolymer is always violent when the molten prepolymer having absorbed the inert gas by the inert gas absorbing device (1) is polymerized. It was found that the foaming state was exhibited, and the phenomenon that the stirring state of the surface was extremely improved was particularly prominent.

  That is, a method in which the prepolymer is constantly melted and flowed down in a foamed state along a guide and polymerized using a polymerizer that proceeds with polymerization is the most preferable embodiment when the system of the present invention is implemented. In addition, “to be constantly melted down in a foaming state” means a state in which foaming continues from the upper portion to the lower portion of the guide. The foaming state can be visually observed by, for example, providing a sight glass in a polymerization vessel.

  In the system of the present invention, the polymerization reactor (10) used in the polymerization step (b) is preferably a system that is a wire contact falling polymerization reactor. In a polymerization vessel in which a prepolymer is melted and dropped along a guide to advance polymerization, the molten prepolymer is usually supplied from a perforated plate and then dropped along a guide. The perforated plate is usually selected from a flat plate, a corrugated plate, a plate with a thick central portion, and the like, and the shape of the perforated plate is usually selected from shapes such as a circle, an ellipse, a triangle, and a polygon. .

The holes in the perforated plate are usually selected from shapes such as a circle, an ellipse, a triangle, a slit, a polygon, and a star. Cross-sectional area of the hole is usually 0.01～100Cm ^2, preferably 0.05～10Cm ^2, particularly preferably from 0.1 to 5 cm ^2. The distance between the holes is usually 1 to 500 mm, preferably 25 to 100 mm, as the distance between the centers of the holes. The hole of the perforated plate may be a hole penetrating the perforated plate or a case where a tube is attached to the perforated plate. Moreover, it may be tapered.

  The guide means a material having a very large ratio of the length in the vertical direction to the average length of the outer circumference of the horizontal cross section. The ratio is usually in the range of 10 to 1,000,000, preferably in the range of 50 to 100,000. The shape of the cross section in the horizontal direction is usually selected from shapes such as a circle, an ellipse, a triangle, a square, a polygon, and a star. The shape of the cross section may be the same or different in the length direction. Further, the guide may be hollow.

  The guide may be a single guide such as a wire, or a plurality of guides may be combined by a method such as twisting. Further, it may be a wire mesh or a punching plate. The surface of the guide may be smooth or uneven, or may partially have protrusions or the like. Preferred guides are cylindrical, such as wire, wire mesh, and punched plate.

  The material of the guide is usually selected from metals such as stainless steel, carbon steel, Hastelloy, nickel, titanium, chromium, and other alloys, and polymer materials having high heat resistance. Further, the surface of the guide may be subjected to various treatments such as plating, lining, passivation treatment, acid washing, and phenol washing as required.

  The positional relationship between the guide and the perforated plate and the positional relationship between the guide and the holes in the perforated plate are not particularly limited as long as the contact with the guide is possible. The guide and the perforated plate may or may not be in contact with each other. As a preferable specific example of the method of providing the guide corresponding to the hole of the perforated plate, (1) the upper end of the guide is fixed to the upper inner wall surface of the polymerization vessel, and the guide penetrates near the center of the hole of the perforated plate. (2) fixing the upper end of the guide to the peripheral edge of the upper end of the hole in the perforated plate and providing the guide in a state where the guide passes through the hole in the perforated plate; The upper end of the guide is fixed to the lower surface of the perforated plate.

  As a method of dropping the molten prepolymer along the guide through the perforated plate, a method of dropping by a liquid head or its own weight, or a method of extruding the molten prepolymer from the perforated plate by pressing using a pump or the like Is mentioned. Preferably, the molten prepolymer discharge pump (9) extrudes a predetermined amount of the molten prepolymer under pressure.

There is no particular limitation on the number of holes, conditions such as reaction temperature and pressure, amount of catalyst, varies depending range, etc. of polymerized to molecular weight, when a normal polymer for example 100 kg / hr production, 10 to 10 ⁵ Holes are required. After passing through the hole, the height for dropping along the guide is preferably 0.3 to 50 m, and more preferably 0.5 to 30 m. The flow rate of the molten prepolymer passing holes varies depending on the molecular weight of the molten prepolymer usually per ^hole, 10 -4 to 10 ⁴ liters / hr, preferably ¹⁰ -2 to 10 ² liters / hr, especially Preferably, it is in the range of 0.05 to 50 l / hr. The time required for dropping along the guide is not particularly limited, but is usually in the range of 0.01 seconds to 10 hours.

  The polymer polymerized while being dropped along the guide may be directly dropped into the liquid reservoir, or may be forcibly taken into the liquid reservoir by a winder or the like. Further, the polymer after dropping along the guide may be extracted as it is, but it is also a preferable method to circulate and polymerize while dropping again along the guide. In this case, the residence time can be prolonged in the liquid storage section or the circulation line after dropping along the guide according to the reaction time required for the polycondensation reaction. In addition, a new liquid surface area that can be formed per unit time can be obtained by circulating while being dropped along the guide, so that the polymerization can easily be sufficiently advanced to a desired molecular weight.

  When implementing the system of the present invention, the polymerization step (b) may be a batch polymerization method performed in a batch manner or a continuous polymerization method performed continuously. In the batch polymerization method, a predetermined amount of the molten prepolymer having absorbed the inert gas in the inert gas absorbing step (a) was supplied to a polymerization zone for performing the polymerization of the molten prepolymer in the polymerization step (b). Thereafter, the supply of the molten prepolymer is stopped, and then the polymerization is performed under a predetermined pressure to polymerize the molten prepolymer to a predetermined degree of polymerization.

  In the continuous polymerization method, the molten prepolymer having absorbed the inert gas in the step (a) is continuously supplied at a predetermined flow rate to the polymerization zone in the polymerization step (b). At a predetermined pressure to polymerize the molten prepolymer to a predetermined degree of polymerization, and continuously withdraw the obtained aromatic polycarbonate from the polymerization zone at a predetermined flow rate in a polymerization step (b). Is carried out continuously to carry out polymerization.

  In the system of the present invention, the molten prepolymer having absorbed the inert gas can be continuously discharged from the inert gas absorbing device (1) at a predetermined flow rate and can be continuously supplied to the polymerization zone at a predetermined flow rate. A continuous polymerization mode including a molten prepolymer discharge pump (9) capable of discharging the aromatic polycarbonate obtained at a predetermined flow rate from the polymerization zone at a predetermined flow rate. A system is preferred.

  In a preferred embodiment of the polymerization according to the present invention, as described above, the polymerization reaction zone of the polymerization reactor (10) is a guide contact drop having at least one guide fixed and extending downward in the polymerization reactor. A polymerization reaction zone, wherein the guide contact drop polymerization reaction zone is separated by a molten prepolymer supply zone absorbing an inert gas and a molten prepolymer distribution plate having at least one hole, and the molten prepolymer A feed zone communicates with the guide contact drop polymerization reaction zone through the hole in the distribution plate, and the guide is disposed corresponding to the hole in the distribution plate, and supplies an inert gas. There is a system configured so that the absorbed molten prepolymer contacts the guide and polymerizes while falling. In the present system, it is particularly preferable that the polymerization reactor (10) is a wire contact falling polymerization reactor.

When implementing the system of the present invention, the inert gas absorption step (a) can be performed batchwise independently of whether the polymerization step (b) is performed batchwise or continuously. , Can be performed continuously. Therefore, when implementing the system of the present invention, depending on whether the inert gas absorption step (a) and the polymerization step (b) are performed in a batch mode or a continuous mode, respectively, the steps (a) and (b) are performed. As for the system, at least the following four combinations are possible. (1) Step (a) in batch mode and step (b) in batch mode
(2) Step (a) in batch mode and step (b) in continuous mode
(3) Step (a) in continuous mode and step (b) in batch mode
(4) Step (a) in continuous mode and step (b) in continuous mode

  In any of these combinations, the system of the present invention can be suitably implemented. However, when a large amount of an aromatic polycarbonate is produced, at least the polymerization step of the step (a) and the step (b) is performed. Preferably, it is performed in a continuous manner. More preferably, both the inert gas absorption step (a) and the polymerization step (b) are performed in a continuous manner.

  When implementing the system of the present invention, a method in which the inert gas absorption step and the polymerization step are sequentially repeated twice or more is also a preferable method. Further, it is of course possible to increase the number of times of the polymerization step more than the inert gas absorption step. For the combination of the inert gas absorption step and the polymerization step, various combinations are possible, and when a plurality of polymerization vessels are used, for example, absorption, polymerization, absorption, polymerization, absorption, polymerization. , "Absorption, polymerization, polymerization, absorption, polymerization ..." and the like. This also applies to the case where the polymer is circulated through the polymerization vessel.

  The reaction for producing an aromatic polycarbonate from an aromatic dihydroxy compound and a diaryl carbonate can be carried out without adding a catalyst. However, in order to increase the polymerization rate, the reaction is carried out in the presence of a catalyst if necessary.

The catalyst is not particularly limited as long as it is used in this field, but hydroxides of alkali metals and alkaline earth metals such as lithium hydroxide, sodium hydroxide, potassium hydroxide, and calcium hydroxide. Lithium aluminum hydride, sodium borohydride, alkali metal salts, alkaline earth metal salts, quaternary ammonium salts of boron or aluminum hydrides such as tetramethylammonium borohydride; lithium hydride, sodium hydride, Hydrogen compounds of alkali metals and alkaline earth metals such as 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; aryloxides of alkali metals and alkaline earth metals such as iO-Ar-OLi and NaO-Ar-ONa (Ar is an aryl group); organic metals of alkali metals and alkaline earth metals such as lithium acetate, calcium acetate and sodium benzoate Acid salts; zinc compounds such as zinc oxide, zinc acetate, zinc phenoxide; boron oxide, boric acid, sodium borate, trimethyl borate, tributyl borate, triphenyl borate, (R ¹ R ² R ³ R ⁴ ) Ammonium borate or phosphonium borate (R ¹ , R ² ) represented by NB (R ¹ R ² R ³ R ⁴ ) or (R ¹ R ² R ³ R ⁴ ) PB (R ¹ R ² R ³ R ⁴ ) , R ^3, R ⁴ is an explanatory as the Formula 1) compounds of boron and the like;. silicon oxide, sodium silicate, Tetoraa Silicon compounds such as killed silicon, tetraarylsilicon, diphenyl-ethyl-ethoxysilicon; germanium compounds such as germanium oxide, germanium tetrachloride, germanium ethoxide, germanium phenoxide; tin oxide, dialkyltin oxide, dialkyltin carboxy Tin compounds such as tin compounds and organotin compounds combined with alkoxy or aryloxy groups such as acrylate, tin acetate and ethyltin tributoxide; lead oxide, lead acetate, lead carbonate, basic carbonate, lead and organic lead Lead compounds such as alkoxides or aryloxides; onium compounds such as quaternary ammonium salts, quaternary phosphonium salts and quaternary arsonium salts; antimony compounds such as antimony oxide and antimony acetate; manganese acetate; Manganese compounds such as manganese carbonate and manganese borate; titanium compounds such as titanium oxide, titanium alkoxide or aryloxide; zirconium compounds such as zirconium acetate, zirconium oxide, zirconium alkoxide or aryloxide, and zirconium acetylacetone. Catalysts may be mentioned.

When a catalyst is used, these catalysts may be used alone or in combination of two or more. The amount of these catalysts to be used is generally selected in the range of 10 ^-8 to 1% by weight, preferably 10 ^-7 to 10 ^-1 % by weight, based on the aromatic dihydroxy compound as the raw material.

  There is no particular limitation on the material of the inert gas absorbing device, the polymerization vessel or the piping used in the present invention, and it is usually made of stainless steel, carbon steel, hastelloy, nickel, titanium, chromium, and other alloys. Metal or a polymer material having high heat resistance. The surface of these materials may be subjected to various treatments such as plating, lining, passivation treatment, acid washing, and phenol washing as required. Particularly preferred are stainless steel, nickel, glass lining and the like.

  The aromatic polycarbonate produced by implementing the system of the present invention has a repeating unit represented by the following formula (7).

(Ar is the same as described above.)
Particularly preferred is an aromatic polycarbonate containing 85 mol% or more of the repeating unit represented by the following formula 8 in all the repeating units.

  Further, the terminal group of the aromatic polycarbonate produced by implementing the system of the present invention usually comprises a hydroxy group or an aryl carbonate group represented by the following formula (9).

(Ar ⁵ is the same as Ar ³ and Ar ⁴ described above.)
The ratio of the hydroxy group to the aryl carbonate group 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 20:20. : 80. Particularly preferred are aromatic polycarbonates in which the proportion of phenyl carbonate groups in the terminal groups is 85 mol% or more.

  The aromatic polycarbonate produced by implementing the system of the present invention may be partially branched through a heterogeneous bond such as an ester bond or an ether bond to the main chain. The hetero bond is usually within 3 mol% based on the carbonate bond. (See, for example, WO 97/32916)

  Particularly preferred among the aromatic polycarbonates produced by implementing the system of the present invention are the substantially halogen-free aromatic polycarbonates prepared by using halogen-free aromatic dihydroxy compounds and diaryl carbonates. Polycarbonate.

Hereinafter, the present invention will be described with reference to examples.
First, the measurement method used for evaluating the samples obtained in the examples and comparative examples will be described.

<Number average molecular weight (Mn)>
It was measured by gel permeation chromatography (GPC) using tetrahydrofuran as a carrier solvent, and the number average molecular weight (Mn) was determined using a reduced molecular weight calibration curve obtained by the following equation using standard monodisperse polystyrene.
MPC = 0.3591 ^{MPS 1.0388}
(In the formula, MPC indicates the molecular weight of aromatic polycarbonate, and MPS indicates the molecular weight of polystyrene.)

<Color>
Using an injection molding machine, a test piece having a length of 50 mm, a width of 50 mm and a thickness of 3.2 mm was continuously formed from an aromatic polycarbonate at a cylinder temperature of 290 ° C and a mold temperature of 90 ° C. The color tone of the obtained test piece was measured by the CIELAB method (Commission International de l'Eclairage 1976 L ^* a ^* b Diagram), and the yellowness was indicated by b ^* value.

<Tensile elongation>
Using an injection molding machine, aromatic polycarbonate was injection molded at a cylinder temperature of 290 ° C. and a mold temperature of 90 ° C. The tensile elongation (%) of the obtained 3.2 mm thick test piece was measured according to ASTM D638.

[Example 1]
As shown in FIG. 1, an inert gas absorption device (1) for absorbing an inert gas into a molten prepolymer, and supplies the molten prepolymer having absorbed the inert gas to a polymerization reactor (10) at a predetermined flow rate. A melt prepolymer discharge pump (9), a polymerization reactor (10) having a polymerization reaction zone including a plurality of cylindrical guides (13), and a pump (18) for discharging the produced aromatic polycarbonate in this order. An aromatic polycarbonate was produced using the combined system. The inert gas absorbing device (1) includes seven SUS316 cylindrical guides (4) each having a diameter of 2 mm and a length of 3 m. The molten prepolymer supplied from the supply port (2) and a plurality of cylindrical guides are provided. An aromatic polycarbonate was produced using a system comprising the polymerization vessel 10 having (13).

  The inert gas absorbing device (1) is provided with seven SUS316 cylindrical guides (4) having a diameter of 2 mm and a length of 3 m, and the molten prepolymer supplied from the supply port 2 is dispersed by a dispersion plate (3). It is evenly distributed to the cylindrical guide (4). An inert gas supply port (5) is provided at the lower part of the inert gas absorption device, and a vent port (6) is provided at the upper part. The outside of the inert gas absorption tower (1) is a jacket and is heated by a heating medium. The polymerization vessel (10) is provided with 70 cylindrical guides (13) made of SUS316 having a diameter of 2.5 mm and a length of 8 m, and the molten polymer supplied from the supply port (11) is dispersed by a dispersion plate (12). It is evenly distributed to the guide (13). An inert gas supply port (14) is provided at the lower part of the polymerization vessel, and a vacuum vent port (15) is provided at the upper part. The outside of the polymerization vessel (10) is a jacket and is heated by a heating medium. In addition, a polymerization vessel sight glass (20) is provided.

After bisphenol A and diphenyl carbonate (mol ratio of bisphenol A to 1.05) are melt-mixed at 180 ° C., the solution is sent to a first vertical stirring tank, polymerized at 230 ° C. and 13,300 Pa for 1 hour, and then vertically stirred. The molten prepolymer of aromatic polycarbonate produced by feeding the solution to the second stirring tank and polymerizing at 270 ° C., 140 Pa and a residence time of 1 hour is flowed in the pipe in the direction of the arrow in FIG. It was continuously supplied to the inert gas absorption device 1 at a flow rate of 50 kg / hr. The number-average molecular weight M ₁ of the molten prepolymer fed to inert gas absorption device was 4,430. The inert gas absorbing apparatus 1 is operated under the conditions of 270 ° C. and a pressure of 200,000 Pa. Nitrogen is supplied from the inert gas supply port (5) so as to keep the pressure at 200,000 Pa with the vent port 6 closed. Have been. The supply amount of nitrogen was 2.0 Nl / Hr. The amount of nitrogen absorbed per kg of molten prepolymer is 0.04 Nl. The value of (4 × 10 ¹² × M ₁ ^-2.66871 ) is 637, which satisfies the condition of the expression (1).

  The molten prepolymer is withdrawn from the discharge port (8) by the discharge pump (9) so that the amount of the molten prepolymer (7) at the bottom of the inert gas absorption device (1) is constant, and the supply port ( From 11), it was continuously supplied to the polymerization vessel (10) at the same flow rate. The polymerization reaction proceeded while the inert gas-absorbing molten prepolymer continuously supplied to the polymerization reaction zone through the dispersion plate (12) in the polymerization vessel was dropped along the guide (13). The produced aromatic polycarbonate entering the bottom portion of the polymerization vessel (10) from the lower portion of the guide (13) is discharged by a discharge pump so that the amount of the aromatic polycarbonate (16) at the bottom of the polymerization vessel (10) is constant. By (18), it was continuously extracted from the discharge port (19).

In this way, a system for continuously producing aromatic polycarbonate was operated. Operating a polymerization reactor has a number average molecular weight _{M 2} of the molten prepolymer fed to (10) 4,450 than the starting from after 50 hours supply opening _{(11), (M} 2 -M ₁₎ 20 And the value of (−0.056 × M ₂ +290) was 41. The polymerization conditions are 270 ° C. and 90 Pa, satisfying the condition of the formula (2). No inert gas was supplied from the inert gas supply port 14. From the sight glass (20), it was observed that the foamed molten prepolymer dropped on the cylindrical guide while the surface was renewed very well. Continuous foaming was also observed from the top to the bottom of the guide.

The aromatic polycarbonate discharged from the discharge port (19) 50 hours after the start of the operation had Mn of 11,500, and had a good color (b ^* value of 3.3). The tensile elongation was 98%. From the start of operation, 60 hours, 70 hours, 80 hours, 90 hours, 100 hours, 1000 hours, 2000 hours, and 3000 hours after the start of operation, the Mn of the aromatic polycarbonate discharged from the outlet 19 is respectively , 11,500, 11,550, 11,500, 11,550, 11,500, 11,500, 11,550, 11,500 and were stable. The results are summarized in Table 1.

[Examples 2 to 5]
An aromatic polycarbonate was manufactured in the same manner as in Example 1 by using the same system as in Example 1 except that the pressure of the inert gas absorption device 1 was different. Table 1 summarizes the conditions and results.

[Examples 6 to 9]
Using the same system as in Example 1 except that the polymerization pressure was different, an aromatic polycarbonate was produced in the same manner as in Example 1. Table 1 summarizes the conditions and results.

[Example 10]
After bisphenol A and diphenyl carbonate (mol ratio of bisphenol A to 1.05) are melt-mixed at 180 ° C., the solution is sent to a first vertical stirring tank, polymerized at 230 ° C. and 13,300 Pa for 1 hour, and then vertically stirred. A molten prepolymer of an aromatic polycarbonate produced by feeding the solution to the second stirring tank and polymerizing at 265 ° C., 1,400 Pa, and a residence time of 1 hour was used in the same system as in Example 1, and the same as in Example 1. Was allowed to absorb nitrogen and polymerized in the same manner as in Example 1 to produce an aromatic polycarbonate. Table 1 summarizes the conditions and results. 50 hours, 60 hours, 70 hours, 80 hours, 90 hours, and 100 hours after the start of operation, the Mn of the aromatic polycarbonate discharged from the outlet 19 was 9,000, 9,000, respectively. , 9,050, 9,000, 9,050, and 9,000, which were stable.

[Examples 11 to 13]
An aromatic polycarbonate was produced in the same manner as in Example 1, except that the temperature of the inert gas absorption device 1, the temperature of the polymerization vessel 10, and the amount of nitrogen supplied were changed. Table 1 summarizes the conditions and results. In Example 11, 50 hours, 60 hours, 70 hours, 80 hours, 90 hours, and 100 hours after the start of operation, Mn of the aromatic polycarbonate discharged from the outlet 19 was 11%, respectively. , 600, 11,600, 11,5500, 11,600, 11,600, 11,550, which were stable.

[Comparative Examples 1 to 3]
An aromatic polycarbonate was produced in the same manner as in Examples 1, 10, and 11, except that the molten prepolymer was directly supplied to the polymerization reactor 10 without passing through the inert gas absorbing device. From the difference in molecular weight before and after polymerization, it can be seen that the comparative examples all have lower polymerization rates than the corresponding examples. In Comparative Example 3, the Mn of the aromatic polycarbonate discharged from the outlet 19 after 50 hours, 60 hours, 70 hours, 80 hours, 90 hours, and 100 hours from the start of operation was 7 respectively. , 600, 7,400, 7,450, 7,500, 7,650, 7,400 and were unstable. Table 1 summarizes the conditions and results.

[Comparative Example 4]
An aromatic polycarbonate was produced in the same manner as in Comparative Example 3, except that the amount of nitrogen supplied to the polymerization vessel was set to 200 Nl / hr. The amount of nitrogen supplied to the polymerization vessel was 4 Nl per 1 kg of molten prepolymer. 50 hours, 60 hours, 70 hours, 80 hours, 90 hours, and 100 hours after the start of operation, the Mn of the aromatic polycarbonate discharged from the outlet 19 was 7,900, 7,700, respectively. , 8,050, 7,700, 7,900, 8,000 and were unstable. Table 1 summarizes the conditions and results.

[Example 14]
An aromatic polycarbonate was produced in the same manner as in Example 1 using the same system as in Example 1, except that argon was absorbed instead of nitrogen with an inert gas absorption device. _M 1 after the start of the operation 50 hours, _{M 2} are each 4,430,4,450, Mn of the aromatic polycarbonate product discharged through outlet 19 is 11,500, excellent color ^{(b *} -value 3 .3). The tensile elongation was 98%.

[Example 15]
An aromatic polycarbonate was produced in the same manner as in Example 1 using the same system as in Example 1 except that carbon dioxide was absorbed instead of nitrogen with an inert gas absorption device. _M 1 after the start of the operation 50 hours, _{M 2} are each 4,430,4,450, Mn of the aromatic polycarbonate product discharged through outlet 19 is 11,500, excellent color ^{(b *} -value 3 .3). The tensile elongation was 98%.

[Example 16]
Using an inert gas absorbing device, the same system as in Example 1 was used, except that nitrogen was supplied at 20 Nl / hr from an inert gas supply port and the pressure was controlled at 200,000 Pa by a vent port 6. Polymerization was carried out in the same manner as in Example 1 to produce an aromatic polycarbonate. After 50 hours from the start of the operation, M ₁ and M ₂ were 4,430 and 4,520, respectively. The Mn of the aromatic polycarbonate discharged from the discharge port 19 was 11,300, and a good color (b ^* value 3) .3). The tensile elongation was 98%.

[Example 17]
An aromatic polycarbonate was produced in the same manner as in Example 16, except that the pressure of the inert gas absorbing device was 900 Pa. After 50 hours from the start of the operation, M ₁ and M ₂ were 4,430 and 4,730, respectively, and (M ₂ −M ₁ ) was 300. The Mn of the aromatic polycarbonate discharged from the discharge port 19 was 11,000, and the color was good (b ^* value 3.3). The tensile elongation was 97%. When observed from the sight glass, the molten prepolymer was always foamed.

[Example 18]
An aromatic polycarbonate was produced in the same manner as in Example 16 except that the pressure of the inert gas absorbing device was set to 700 Pa. After 50 hours from the start of operation, M ₁ and M ₂ were 4,430 and 4,840, respectively, and (M ₂ −M ₁ ) was 410. The Mn of the aromatic polycarbonate discharged from the discharge port 19 was 10,700, and the color was good (b ^* value 3.3). Further, the tensile elongation was 95%. When observed from the sight glass, the molten prepolymer was always foamed.

[Example 19]
An aromatic polycarbonate was produced in the same manner as in Example 16, except that the pressure of the inert gas absorbing device was set to 500 Pa. After 50 hours from the start of operation, M ₁ and M ₂ were 4,430 and 4,980, respectively, and (M ₂ −M ₁ ) was 550. The Mn of the aromatic polycarbonate discharged from the discharge port 19 was 9,900, and the color was good (b ^* value 3.3). Further, the tensile elongation was 92%. Observation from the sight glass revealed that the molten prepolymer was intermittently foamed.

[Example 20]
The same inert gas absorbing apparatus 1 as in Example 1 and a polymerization apparatus 10 were implemented using a system including a horizontal stirring tank having an internal volume of 1.5 m ³ and a length of 4 m having two stirring shafts having a rotation diameter of 0.4 m and a length of 4 m. In the same manner as in Example 1, polymerization of a molten prepolymer having nitrogen absorbed by an inert gas absorbing device was performed. The supply amount of the molten prepolymer, the polymerization temperature, and the polymerization pressure were the same as in Example 1. The rotation speed of the stirring shaft is 15 rpm. The Mn of the aromatic polycarbonate discharged from the polymerization reactor 50 hours after the start of the operation was 10,500, the b ^* value was 3.6, and the tensile elongation was 94%.

[Comparative Example 5]
An aromatic polycarbonate was produced in the same manner as in Example 20, except that the molten prepolymer was directly supplied to the horizontal stirring tank without passing through the inert gas absorbing device. The Mn of the aromatic polycarbonate discharged from the polymerization reactor 50 hours after the start of the operation was 8,900, the b ^* value was 3.9, and the tensile elongation was 89%.

[Example 21]
An aromatic polycarbonate was produced in the same manner as in Example 1 except that the inert gas absorbing device 1 was not provided with a cylindrical guide. After 50 hours from the start of the operation, M ₁ and M ₂ were 4,430 and 4,430, respectively. The Mn of the aromatic polycarbonate discharged from the discharge port 19 was 11,400, and a good color (b ^* value 3) .3). The tensile elongation was 98%.

[Example 22]
The same system as in Example 1 except that the polymerization device (10) is provided with eight 1-mesh wire meshes (wire diameter 2 mm) made of SUS316 having a width of 100 mm and a length of 8 m as a guide for the polymerization device (10). An aromatic polycarbonate was produced in the same manner as in Example 1. _M 1 after the start of the operation 50 hours, _{M 2} are each 4,430,4,450, Mn of the aromatic polycarbonate product discharged through outlet 19 is 11,800, excellent color ^{(b *} -value 3 .3). The tensile elongation was 97%.

[Example 23]
The same system as in Example 1 except that a molten prepolymer prepared from 1,1-bis- (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane is used instead of bisphenol A The reaction was performed under the following conditions. _M 1 after the start of the operation 50 hours, _{M 2} are each 4,410,4,430, Mn of the aromatic polycarbonate product discharged through outlet 19 is 11,100, excellent color ^{(b *} -value 3 .3). Further, the tensile elongation was 94%.

  According to the system of the present invention, from a molten prepolymer of an aromatic polycarbonate obtained by reacting an aromatic dihydroxy compound with a diaryl carbonate, a high-quality aromatic polycarbonate having excellent mechanical properties without coloring is obtained by high polymerization. The system of the present invention is extremely industrially advantageous because it can be produced at a high speed without using a large amount of inert gas, and furthermore, the aromatic polycarbonate can be produced stably for a long period with little variation in molecular weight. And industrial applicability is very high.

It is a schematic diagram showing an example which constitutes a system of the present invention.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Inert gas absorption apparatus 2 Supply port of molten prepolymer 3 Dispersion plate of molten prepolymer 4 Cylindrical guide 5 Inert gas supply port 6 Vent port used as required 7 Molten prepolymer absorbing inert gas 8 Non Discharge port of molten prepolymer that has absorbed active gas 9 Discharge pump of molten prepolymer that has absorbed inert gas 10 Polymerizer 11 Supply port of molten prepolymer that has absorbed inert gas 12 Molten prepolymer that has absorbed inert gas Dispersion plate 13 Cylindrical guide 14 Inert gas supply port 15 optionally used Vacuum vent port 16 Aromatic polycarbonate 17 Aromatic polycarbonate discharge port 18 Aromatic polycarbonate discharge pump 19 Aromatic polycarbonate extraction port 20 Sight glass for observing the foaming state of the polymer

Claims (7)

  An inert gas absorbing device (1) for absorbing an inert gas into a molten prepolymer of an aromatic polycarbonate obtained by reacting an aromatic dihydroxy compound with a diaryl carbonate; A polymerization reactor (10) having a polymerization reaction zone for performing polymerization, for supplying the molten prepolymer having absorbed the inert gas from the inert gas absorption device (1) to the polymerization reactor (10) at a predetermined flow rate; And a discharge pump (18) for discharging the aromatic polycarbonate obtained in the polymerization vessel (10), and the inert gas absorption device (1), The melt prepolymer discharge pump (9), the polymerizer (10), and the aromatic polycarbonate discharge pump (18) are connected in this order. System for producing an aromatic polycarbonate, characterized by comprising been.   The inert gas absorbing device (1) includes a molten prepolymer supply port for an aromatic polycarbonate, an inert gas supply port, and an inert gas absorbed by the molten prepolymer to obtain a molten prepolymer that has absorbed the inert gas. An inert gas-absorbing zone, and an outlet for the molten prepolymer that has absorbed the inert gas, wherein the polymerization vessel (10) has a supply port for the molten prepolymer that has absorbed the inert gas, A supply zone for the molten prepolymer absorbing an inert gas for supplying the molten prepolymer to the polymerization reaction zone, a polymerization reaction zone, a vacuum vent provided in the polymerization reaction zone, and an aromatic polycarbonate outlet. And the aromatic polycarbonate discharge pump (18) discharges the aromatic polycarbonate at a predetermined flow rate from the discharge port of the polymerization vessel (10). System for producing an aromatic polycarbonate according to claim 1, characterized in that the pump which is capable of out come.   A polymerization reaction zone of the polymerization vessel (10) for polymerizing the molten prepolymer that has absorbed the inert gas, a guide contact having at least one guide fixed and extending downward in the polymerization vessel (10); A fall polymerization reaction zone, wherein the guide contact fall polymerization reaction zone is separated by a molten prepolymer supply zone absorbing an inert gas and a molten prepolymer distribution plate having at least one hole, and the molten prepolymer The feed zone communicates with the guide contact drop polymerization reaction zone through the hole of the distribution plate, and the guide is disposed corresponding to the hole of the distribution plate. A system for producing the aromatic polycarbonate according to claim 1.   The system for producing an aromatic polycarbonate according to any one of claims 1 to 3, wherein the polymerization reactor (10) is a wire contact falling polymerization reactor.   The system for producing an aromatic polycarbonate according to claim 3, wherein the guide is cylindrical.   The system for producing an aromatic polycarbonate according to claim 3, wherein the guide is a wire mesh.   The system for producing an aromatic polycarbonate according to claim 3, wherein the guide is in the form of a punching plate.

Images