HK1177215B - Process for production of highly polymerized aromatic polycarbonate resin - Google Patents

Description

Method for producing aromatic polycarbonate resin having increased molecular weight

Technical Field

The present invention relates to a method for increasing the molecular weight of an aromatic polycarbonate resin. More specifically, the present invention relates to a process for producing a high-quality polycarbonate resin having a high polymerization degree and an Mw of about 30,000 to 100,000, which is produced by chain extension of an aromatic polycarbonate by linking the terminal blocks with an aliphatic diol compound,

background

Polycarbonates have been widely used in many fields in recent years because of their excellent heat resistance, impact resistance and transparency. In the production method of the polycarbonate, many studies have been made in the past. Among them, polycarbonates derived from aromatic dihydroxy compounds such as 2, 2-bis (4-hydroxyphenyl) propane (hereinafter referred to as "bisphenol a") are industrially produced by both production methods, i.e., interfacial polymerization and melt polymerization.

According to this interfacial polymerization method, polycarbonate is produced from bisphenol a and phosgene, but toxic phosgene must be used. In addition, the following problems remain: corrosion of the apparatus due to chlorine-containing compounds such as hydrogen chloride and sodium chloride which are by-produced and methylene chloride which is used as a solvent in a large amount; it is difficult to remove impurities such as sodium chloride and residual methylene chloride, which affect the physical properties of the polymer.

On the other hand, as a method for producing a polycarbonate from an aromatic dihydroxy compound and a diaryl carbonate, for example, a melt polymerization method has been known in which an aromatic monohydroxy compound produced as a by-product is removed by polymerizing bisphenol a and diphenyl carbonate by an ester exchange reaction in a molten state. Unlike the interfacial polymerization method, the melt polymerization method has an advantage of not using a solvent, but has the following essential problems: the viscosity of the polymer in the system rapidly increases as the polymerization proceeds, and it becomes difficult to efficiently remove the aromatic monohydroxy compound produced as a by-product out of the system, and the reaction rate extremely decreases, making it difficult to increase the polymerization degree.

In order to solve this problem, various attempts have been made to remove the aromatic monohydroxy compound from the polymer in a high viscosity state. For example, patent document 1 (Japanese patent publication (Kokoku) No. 50-19600) discloses a screw type polymerizer having a curved portion, and patent document 2 (Japanese patent publication (Kokoku) No. 2-153923) also discloses a method using a combination of a thin film evaporation apparatus and a horizontal polymerization apparatus.

Further, patent document 3 (U.S. Pat. No. 5,521,275) discloses a method of converting the molecular weight of an aromatic polycarbonate under a reduced pressure condition using an extruder having a polymer seal part and a bending part in the presence of a catalyst.

However, the methods disclosed in these publications cannot sufficiently increase the molecular weight of the polycarbonate. If the polymerization is carried out by a method using a large amount of the above-mentioned catalyst or under severe conditions such as imparting high shear, the following problems occur: the resin is greatly affected by deterioration in hue, occurrence of a crosslinking reaction, and the like.

Further, it is known that the degree of polymerization of polycarbonate can be increased by adding a polymerization accelerator to the reaction system in the melt polymerization method. The increase in molecular weight is carried out by a short reaction residence time and a low reaction temperature, and the yield of polycarbonate can be improved, and further, the design of a simple and inexpensive reactor can be easily carried out.

Patent document 4 (european patent No. 0595608) discloses reacting some diaryl carbonates during molecular weight conversion, but a significant increase in molecular weight is not obtained. Patent document 5 (U.S. Pat. No. 5,696,222) discloses a method for producing a polycarbonate having a high degree of polymerization by adding a certain polymerization accelerator, for example, an aryl ester compound of carbonic acid and dicarboxylic acid represented by bis (2-methoxyphenyl) carbonate, bis (2-ethoxyphenyl) carbonate, bis (2-chlorophenyl) carbonate, bis (2-methoxyphenyl) terephthalate, and bis (2-methoxyphenyl) adipate. Patent document 5 teaches that when an ester is used as a polymerization accelerator, an ester bond is introduced, and as a result (instead of a homopolymer), a polyester carbonate is produced to produce a polyester carbonate copolymer, which has low hydrolytic stability.

Patent document 6 (patent No. 4112979) discloses a method of reacting several salicylic acid based carbonates in order to increase the molecular weight of an aromatic polycarbonate.

Patent document 7 (jp 2008-.

Further, patent document 8 (japanese patent No. 4286914) discloses a method of performing a coupling reaction of an aromatic polycarbonate in which the amount of terminal hydroxyl groups is increased by an active hydrogen compound (dihydroxy compound) and then the amount of terminal hydroxyl groups is increased by a salicylate derivative.

However, the method disclosed in the above publication, in which the terminal hydroxyl group of the polycarbonate is increased, requires a reaction step with an active hydrogen compound and a reaction step with a salicylate derivative, and therefore, the steps are complicated, and the polycarbonate having a large number of hydroxyl terminals is likely to have low thermal stability and deteriorated physical properties. Further, as shown in non-patent documents 1to 2, the increase in the hydroxyl group due to the active hydrogen compound causes a partial chain cleavage reaction, and the molecular weight distribution is expanded. Further, it is considered that the use of a catalyst is required in a relatively large amount in order to obtain a sufficient reaction rate, and physical properties during molding may be deteriorated.

Further, patent document 9 (Japanese patent publication No. 6-94501) discloses a method for producing a polymer polycarbonate by introducing 1, 4-cyclohexanediol. However, in the method disclosed herein, since 1, 4-cyclohexanediol is charged together with the aromatic dihydroxy compound at the beginning of the polycondensation reaction system, it is considered that 1, 4-cyclohexanediol is consumed (oligomerized) first in the polycarbonateization reaction, and then the aromatic dihydroxy compound is reacted to increase the molecular weight. Therefore, the reaction time is relatively long, and the physical properties of the appearance of the color phase are liable to deteriorate.

Further, patent document 10 (japanese patent application laid-open No. 2009-102536) describes a method for producing a polycarbonate by copolymerizing a specific aliphatic diol and an ether diol, but the polycarbonate disclosed herein does not exhibit excellent impact resistance required for an aromatic polycarbonate because the polycarbonate mainly has an isosorbide skeleton.

Thus, conventional methods for producing high molecular weight aromatic polycarbonates have many problems, and there is still a demand for improved production methods that can achieve a sufficient molecular weight while maintaining the original good quality of polycarbonates.

Documents of the prior art

Patent document

Patent document 1: japanese patent publication No. 50-19600

Patent document 2: japanese unexamined patent publication No. 2-153923

Patent document 3: U.S. Pat. No. 5,521,275

Patent document 4: european patent No. 0595608 publication

Patent document 5: U.S. Pat. Nos. 5,696,222

Patent document 6: japanese patent No. 4112979

Patent document 7: special table 2008 + 514754

Patent document 8: japanese patent No. 4286914

Patent document 9: japanese examined patent publication (JP-B-6-94501)

Patent document 10: japanese laid-open patent publication No. 2009-102536

Non-patent document

Non-patent document 1: "polycarbonate handbook" (Nissan industry News Co.) p.344

Non-patent document 2: "polycarbonate resin" (news agency of Japanese Industrial Co., Ltd.), lecture 5 and p.144 of plastic material

Disclosure of Invention

Problems to be solved by the invention

The present invention addresses the problem of providing an improved method for producing a high-molecular-weight aromatic polycarbonate resin, which can achieve a sufficient high molecular weight while maintaining good quality of the aromatic polycarbonate resin.

Means for solving the problems

The present inventors have conducted intensive studies to solve the above problems, and as a result, have found that: the present inventors have completed the present invention by producing a high molecular weight aromatic polycarbonate through a simple process by conducting an ester interchange reaction between a terminal-blocked aromatic polycarbonate and a specific aliphatic diol compound in the presence of an ester interchange catalyst under reduced pressure.

That is, the present invention relates to a method for producing a high molecular weight aromatic polycarbonate resin as described below.

(1) A method for producing an aromatic polycarbonate resin having a high molecular weight, comprising the following high molecular weight-producing step: an aromatic polycarbonate and an aliphatic diol compound having a boiling point of 240 ℃ or higher are linked by an ester interchange reaction in the presence of an ester interchange catalyst under a reduced pressure to increase the molecular weight.

(2) The production method according to (1), wherein the aliphatic diol compound is a compound represented by the following general formula (I).

[ solution 1]

HO-(CH₂)_n-Q-(CH₂)_n-OH…(I)

(wherein Q represents a C6-40 hydrocarbon group which may contain an aromatic ring, and n represents an integer of 0-10, and when Q does not contain an aliphatic hydrocarbon group, n represents an integer of 1-10.)

(3) The production method according to (2), wherein the aliphatic diol compound is a compound represented by any of the following general formulae (II) to (IV).

[ solution 2]

HO-(CH₂)_n1-Q₁-(CH₂)_n1-OH…(II)

HO-(CH₂)_n2-Q₂-(CH₂)_n2-OH…(III)

HO-(CH₂)_n3-Q₃-(CH₂)_n3-OH…(IV)

(in the general formula (II), Q₁The aromatic ring is a C6-40 hydrocarbon group. n1 represents an integer of 1to 10.

In the above general formula (III), Q₂Represents a straight or branched hydrocarbon group having 6 to 40 carbon atoms which may contain a heterocycle. n2 represents an integer of 1to 10.

In the above general formula (IV), Q₃Represents a C6-40 cyclic hydrocarbon group. n3 represents an integer of 0to 10. )

(4) The production method according to (3), wherein the aliphatic diol compound is a compound represented by the following general formula (II).

[ solution 3]

HO-(CH₂)_n1-Q₁-(CH₂)_n1-OH…(II)

(in the above general formula (I I), Q₁The aromatic ring is a C6-40 hydrocarbon group. n1 represents an integer of 1to 10).

(5) The process according to (4), wherein the aliphatic diol compound is selected from the group consisting of 4,4 '-bis (2-hydroxyethoxy) biphenyl, 2' -bis [ (2-hydroxyethoxy) phenyl ] propane, 9-bis [4- (2-hydroxyethoxy) phenyl ] fluorene, fluorenediol, and fluorenediethanol.

(6) The production process according to any one of (1) to (5), wherein the amount of the aliphatic diol compound added is 0.01to 1.0 mol based on 1 mol of the total terminal amount of the aromatic polycarbonate before the transesterification reaction.

(7) The production process according to any one of (1) to (6), wherein at least a part of the aromatic polycarbonate before the ester interchange reaction in the step of increasing the molecular weight is end-capped.

(8) The production method according to (7), wherein the aromatic polycarbonate before the ester interchange reaction is a prepolymer having a blocked end obtained by a reaction of an aromatic dihydroxy compound and a carbonic acid diester.

(9) The production method according to (7) or (8), wherein the concentration of the hydroxyl terminal group of the aromatic polycarbonate before the ester interchange reaction in the step of increasing the molecular weight is 1,500ppm or less.

(10) The production process according to any one of (1) to (9), wherein the weight average molecular weight (Mw) of the aromatic polycarbonate having been subjected to the high molecular weight polymerization after the transesterification reaction in the high molecular weight polymerization step is higher by 5,000 or more than the weight average molecular weight (Mw) of the aromatic polycarbonate before the transesterification reaction.

(11) The production process according to any one of (1) to (10), wherein the aromatic polycarbonate before the ester interchange reaction in the high molecular weight polymerization step has a weight average molecular weight (Mw) of 5,000 to 60,000.

(12) The production process according to any one of (1) to (11), wherein the transesterification reaction in the step of increasing the molecular weight is carried out at a temperature of 240 to 320 ℃ under reduced pressure.

(13) The production process according to any one of (1) to (12), wherein the transesterification reaction in the step of increasing the molecular weight is carried out under a reduced pressure of from 13kPaA (100torr) to 0.01kPaA (0.01 torr).

(14) The production method according to any one of (1) to (13), characterized by comprising: a prepolymer production step of producing a prepolymer having a blocked end by reacting an aromatic dihydroxy compound with a carbonic acid diester; and a high molecular weight conversion step of converting the molecular weight of the prepolymer into a high molecular weight by connecting the prepolymer having a blocked terminal to an aliphatic diol compound having a boiling point of 240 ℃ or higher by transesterification in the presence of a transesterification catalyst under reduced pressure.

(15) An aromatic polycarbonate resin having a high molecular weight, which is obtained by the production method described in any of (1) to (14).

(16) The aromatic polycarbonate resin having a high molecular weight according to item (15), wherein the weight average molecular weight (Mw) is 30,000 to 100,000.

ADVANTAGEOUS EFFECTS OF INVENTION

The present invention relates to a method for obtaining a high molecular weight aromatic polycarbonate by a simple process, in which an aliphatic diol compound as a specific active hydrogen compound is subjected to an ester interchange reaction with a terminally blocked aromatic polycarbonate under a reduced pressure in the presence of an ester interchange catalyst. Thus, a high molecular weight material having good quality can be obtained in a short time under mild conditions in the melt polymerization method. The aromatic polycarbonate to be subjected to the transesterification reaction (chain extension reaction or high molecular weight reaction) may be an aromatic polycarbonate obtained by a conventional interfacial method or a polycarbonate obtained by a melt polymerization method. Further, an aromatic polycarbonate obtained by primary polymerization and molding may be used.

According to the present invention, since the time required for the polymerization of the polycarbonate can be shortened and the polymerization can be carried out under mild conditions (low temperature and high speed polymerization reaction), high temperature and high shear conditions can be avoided as compared with the conventional method, and coloring, crosslinking, gelation and the like do not occur in the resin, whereby an aromatic polycarbonate resin having excellent hue and quality can be obtained. Further, since the aliphatic diol compound itself is used as the linking agent, the reaction step using a salicylic acid derivative is not required, the molecular weight can be increased by a simple step, and the method is excellent in economical efficiency, as compared with a conventional method using a salicylic acid derivative or the like as the linking agent.

The aromatic polycarbonate resin having a high molecular weight obtained by the method of the present invention has physical properties equivalent to those of a conventional polycarbonate resin homopolymer (BPA) although it is a copolymerized polycarbonate containing an aliphatic diol compound as a constituent unit, and can be easily increased in molecular weight by a melting method.

It is very significant that a polycarbonate having the same physical properties as BPA having a high molecular weight can be obtained by the melt method in the interfacial method which is environmentally avoided by using phosgene, an organic solvent, or the like.

Detailed Description

The method for producing an aromatic polycarbonate resin having a high molecular weight of the present invention is characterized by comprising the following high molecular weight production step: the aromatic polycarbonate and the aliphatic diol compound are linked by an ester interchange reaction in the presence of an ester interchange catalyst under a reduced pressure to increase the molecular weight.

(1) Aromatic polycarbonate resin

The aromatic polycarbonate resin to be subjected to the high molecular weight polymerization step of the method of the present invention (i.e., the aromatic polycarbonate resin before the transesterification reaction (hereinafter referred to as "high molecular weight polymerization reaction") in the high molecular weight polymerization step of the method of the present invention) is a polycondensation polymer having a structure represented by the following general formula (1) as a main repeating unit.

[ solution 4]

In the above general formula (1), R₁And R₂Each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1to 20 carbon atoms, an alkoxy group having 1to 20 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a cycloalkoxy group having 6 to 20 carbon atoms, or an aryloxy group having 6 to 20 carbon atoms. p and q represent integers of 0to 4. In addition, X represents a group selected from a divalent organic group represented by the following general formula (1').

[ solution 5]

In the above general formula (1'), R₃And R₄Each independently represents a hydrogen atom, an alkyl group having 1to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms, R₃And R₄Or may be bonded to form an alicyclic ring.

The aromatic polycarbonate resin before the polymerization reaction may be synthesized by an interfacial polymerization method or a melt polymerization method, or may be synthesized by a solid-phase polymerization method, a thin-film polymerization method, or the like. Further, polycarbonate or the like recovered from used products such as used dish-shaped articles may be used. These polycarbonates may be mixed and used as a polymer before reaction. For example, a polycarbonate polymerized by an interfacial polymerization method and a polycarbonate polymerized by a melt polymerization method may be mixed, or a polycarbonate polymerized by a melt polymerization method or an interfacial polymerization method and a polycarbonate recovered from a used dish-shaped article or the like may be mixed and used.

The aromatic polycarbonate resin before the high molecular weight reaction of the present invention may be a polycondensate having as a main repeating unit a reaction product of an aromatic dihydroxy compound and a carbonate bond-forming compound.

Therefore, the aromatic polycarbonate resin before the high molecular weight reaction can be easily obtained by a known transesterification method in which an aromatic dihydroxy compound derived from each structure is reacted with a carbonic acid diester in the presence of a basic catalyst, or a known interfacial polycondensation method in which an aromatic dihydroxy compound is reacted with phosgene or the like in the presence of an acid bonding agent.

Examples of the aromatic dihydroxy compound include compounds represented by the following general formula (2).

[ solution 6]

In the above general formula (2), R₁And R₂Each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1to 20 carbon atoms, an alkoxy group having 1to 20 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a cycloalkoxy group having 6 to 20 carbon atoms, or an aryloxy group having 6 to 20 carbon atoms. p and q represent integers of 0to 4. In addition, X represents a group selected from a divalent organic group represented by the following general formula (2').

[ solution 7]

In the above general formula (2'), R₃And R₄Each independently represents a hydrogen atom, an alkyl group having 1to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms, R₃And R₄Or may be bonded to form an alicyclic ring.

Specific examples of such aromatic dihydroxy compounds include bis (4-hydroxyphenyl) methane, 1-bis (4-hydroxyphenyl) ethane, 2-bis (4-hydroxyphenyl) propane, 2-bis (4-hydroxyphenyl) butane, 2-bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, 1-bis (4-hydroxyphenyl) -1-phenylethane, bis (4-hydroxyphenyl) diphenylmethane, 2-bis (4-hydroxy-3-methylphenyl) propane, 1-bis (4-hydroxy-3-tert-butylphenyl) propane, 2-bis (3, 5-dimethyl-4-hydroxyphenyl) propane, 2, 5-dimethyl-4-hydroxyphenyl) propane, and the like, 2, 2-bis (4-hydroxy-3-phenylphenyl) propane, 2-bis (3-cyclohexyl-4-hydroxyphenyl) propane, 2-bis (4-hydroxy-3-bromophenyl) propane, 2-bis (3, 5-dibromo-4-hydroxyphenyl) propane, 1-bis (4-hydroxyphenyl) cyclopentane, 1-bis (4-hydroxyphenyl) cyclohexane, 2-bis (4-hydroxy-3-methoxyphenyl) propane, 4 ' -dihydroxydiphenyl ether, 4 ' -dihydroxy-3, 3 ' -dimethylphenyl ether, 4 ' -dihydroxyphenyl sulfide, 4 ' -dihydroxy-3, 3 ' -dimethyldiphenylsulfide, 4 ' -dihydroxydiphenylsulfoxide, 4 ' -dihydroxy-3, 3 ' -dimethyldiphenylsulfoxide, 4 ' -dihydroxydiphenylsulfone, 4 ' -dihydroxy-3, 3 ' -dimethyldiphenylsulfone, and the like.

Among them, from the viewpoint of stability of the monomer, and easy availability of a substance containing a small amount of impurities, etc., a more preferable substance is 2, 2-bis (4-hydroxyphenyl) propane, etc.

The aromatic polycarbonate of the present invention may be used in combination with a plurality of the above-mentioned various monomers (aromatic dihydroxy compounds) as required for the purpose of controlling the glass transition temperature, improving the fluidity, improving the refractive index, reducing the birefringence and other optical properties.

Next, the basic means of the method for producing the aromatic polycarbonate resin before the reaction for increasing the molecular weight is briefly described.

In the interfacial polymerization method, examples of the carbonate bond-forming compound include a carbonyl halide such as phosgene and a haloformate compound.

In the reaction using phosgene, for example, the carbonate bond forming compound is usually reacted in the presence of an acid-binding agent and a solvent. As the acid binder, for example, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and amine compounds such as pyridine can be used. As the solvent, for example, a halogenated hydrocarbon such as dichloromethane or chlorobenzene can be used. In addition, a catalyst such as a tertiary amine or a quaternary ammonium salt may be used to promote the reaction. In this case, the reaction temperature is usually 0to 40 ℃ and the reaction time is several minutes to 5 hours.

In the melt polymerization method, a carbonic acid diester is used as the carbonate bond forming compound. Examples of the carbonic acid diester compound include compounds represented by the following general formula (4).

[ solution 8]

Wherein A in the general formula (4) is a linear, branched or cyclic monovalent hydrocarbon group having 1to 10 carbon atoms which may be substituted. The 2A's may be the same or different from each other.

Specific examples of the carbonic acid diester include aromatic carbonic acid diesters such as diphenyl carbonate, ditolyl carbonate, bis (2-chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate and bis (4-phenylphenyl) carbonate. In addition, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate and the like may be used as desired. Among them, diphenyl carbonate is preferable in view of reactivity, stability against coloring of the obtained resin, and further cost. The carbonic acid diester is preferably used in a ratio of 0.95 to 1.30 mol, more preferably 0.98 to 1.20 mol, based on 1 mol of the total of the aromatic dihydroxy compounds.

The melt polymerization method using a carbonic acid diester as a carbonate bond forming compound is carried out by the following method: the aromatic dihydroxy component and the carbonic acid diester are stirred while being heated in a predetermined ratio under an inert gas atmosphere, and the produced alcohol or phenol is distilled off. The reaction temperature varies depending on the boiling point of the alcohol or phenol to be produced, but is usually within a range of 120 to 350 ℃. The reaction is terminated by distilling off the alcohol or phenol produced under reduced pressure from the beginning of the reaction. In addition, a basic compound or a transesterification catalyst which is generally used may be used to promote the reaction.

In the present invention, the aromatic polycarbonate resin before the high molecular weight reaction is preferably obtained by subjecting an aromatic dihydroxy compound and a carbonic acid diester to an ester interchange reaction. Further, the aromatic polycarbonate resin before the high molecular weight reaction is preferably a prepolymer having blocked ends obtained by the reaction of an aromatic dihydroxy compound and a carbonic acid diester.

The terminal group of the aromatic polycarbonate resin having blocked terminals is preferably a blocked terminal group composed of an aromatic monohydroxy compound in an amount of 60% or more, more preferably 70% or more, and particularly preferably 80% or more, based on the total terminals. In this case, the effects unique to the present invention can be particularly remarkably exhibited.

The proportion of the amount of the blocked end relative to the total amount of the end of the polymer may be determined by the amount of the polymer¹H-NMR analysis was carried out. The hydroxyl end concentration may be measured by spectroscopic measurement of the Ti composite, and the hydroxyl end concentration obtained by the same evaluation is preferably 1,500ppm or less, more preferably 1,000ppm or less, but is preferably high in the effect of the high molecular weight reaction.

In the linking reaction (high molecular weight reaction) in the high molecular weight step of the method of the present invention, since the transesterification reaction between the terminal blocking group and the introduced aliphatic diol compound is used, when the amount of the terminal hydroxyl group is more than the above range or the amount of the terminal blocking group is less than the above range, a sufficient effect of high molecular weight by the linking reaction (high molecular weight reaction) may not be obtained.

Specific examples of the blocked terminal group include terminal groups such as a phenyl terminal, a tolyl terminal, an o-tolyl terminal, a p-tert-butylphenyl terminal, a biphenyl terminal, an o-methoxycarbonylphenyl terminal, and a p-cumylphenyl terminal.

Among them, the terminal group composed of a low-boiling aromatic monohydroxy compound which is easily removed from the reaction system by a ligation reaction described later is preferable, and may be a phenyl terminal, a p-tert-butylphenyl terminal or the like.

Such a terminal group can be introduced by using a terminal stopper in the production of an aromatic polycarbonate by the interfacial method. Specific examples of the terminal-stopping agent include p-tert-butylphenol, phenol, p-cumylphenol, and long-chain alkyl-substituted phenol. The amount of the terminal stopper to be used may be suitably determined depending on the desired terminal amount of the aromatic polycarbonate (i.e., the desired molecular weight of the aromatic polycarbonate), the reaction apparatus, the reaction conditions, and the like.

In the melt method, when an aromatic polycarbonate is produced, a terminal group can be introduced by using a carbonic acid diester such as diphenyl carbonate in an excess amount relative to the aromatic dihydroxy compound. Specifically, the carbonic acid diester is used in an amount of 1.00 to 1.30 mol, more preferably 1.02 to 1.20 mol, based on 1 mol of the aromatic dihydroxy compound. Thus, an aromatic polycarbonate satisfying the above-mentioned terminal-blocking amount can be obtained.

In the method of the present invention, a prepolymer having a blocked end obtained by reacting an aromatic dihydroxy compound with a carbonic acid diester (ester interchange reaction) is preferably used as the aromatic polycarbonate resin before the high molecular weight reaction.

Further, in the production of an aromatic polycarbonate resin having a repeating unit structure represented by the above general formula (1), a polyester carbonate may be formed by using the above aromatic dihydroxy compound and a dicarboxylic acid compound in combination.

The dicarboxylic acid compound is preferably terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, 1, 4-cyclohexanedicarboxylic acid, or the like, and these dicarboxylic acids are preferably reacted as acid chlorides or ester compounds. In addition, in the production of polyester carbonate resin, when the total of the dihydroxy component and the dicarboxylic acid component is 100 mol%, the dicarboxylic acid is preferably used in the range of 0.5 to 45 mol%, more preferably 1to 40 mol%.

The molecular weight of the aromatic polycarbonate resin before the high molecular weight reaction in the high molecular weight step used in the method of the present invention is preferably a prepolymer having a weight average molecular weight (Mw) of 5,000 to 60,000. The prepolymer has a weight average molecular weight (Mw) of preferably 10,000 to 50,000, more preferably 10,000 to 40,000.

When the prepolymer having a low molecular weight exceeding this range is used, the influence of the physical properties of the copolymer becomes large. Although the improvement of physical properties can be achieved by this, it is not preferable as an effect of increasing the molecular weight of the aromatic polycarbonate.

When a prepolymer having a high molecular weight exceeding this range is used, the concentration of active ends decreases, and the effect of increasing the molecular weight is small. In addition, since the prepolymer itself has a high viscosity, it is necessary to carry out the reaction under high temperature, high shear and long time as reaction conditions, and it is not preferable to obtain a high-quality aromatic polycarbonate.

(2) Aliphatic diol compound

In the present invention, the aromatic polycarbonate having the blocked terminals is reacted with an aliphatic diol compound as a linking agent in the presence of an ester exchange catalyst under reduced pressure, whereby the molecular weight can be increased at high speed under mild conditions. That is, by replacing the terminal block group consisting of the aromatic hydroxy compound existing in the polycarbonate before the reaction with an alcoholic hydroxy group, the linking reaction between the aromatic polycarbonate resins before the reaction for increasing the molecular weight can be easily performed, and the molecular weight can be increased.

The aliphatic diol compound used in the step of increasing the molecular weight in the method of the present invention must have a boiling point higher than that of an aromatic monohydroxy compound which is produced as a by-product by the reaction and distilled off from the aromatic polycarbonate resin having a blocked end and subjected to the reaction for increasing the molecular weight. In addition, since immobilization needs to be performed while using the above treatment temperature and treatment pressure, an aliphatic diol compound having a higher boiling point is desirably used for the linking reaction. Specifically, an aliphatic diol compound having a boiling point of 240 ℃ or higher, preferably 250 ℃ or higher can be used. The upper limit is not particularly limited, but is sufficient at 500 ℃ or lower.

The "aliphatic diol compound" in the present invention means a compound having a chain or cyclic aliphatic hydrocarbon group (alkylene group or cycloalkylene group) bonded to a terminal OH group, and more specifically, a compound having an alcoholic hydroxyl group with a valence of 2 represented by the following general formula (I).

[ solution 9]

HO-(CH₂)_n-Q-(CH₂)_n-OH…(I)

In the general formula (I), Q represents a C6-40 hydrocarbon group, preferably a C6-30 hydrocarbon group. The hydrocarbon group may be linear or branched, or may have a cyclic structure. Further, the compound may have a cyclic structure such as an aromatic ring or a heterocyclic ring. n represents an integer of 0to 10, preferably 1to 4. Wherein n represents an integer of 1to 10, preferably 1to 4, when Q does not contain an aliphatic hydrocarbon group.

The aliphatic diol compound used in the present invention is more preferably a compound having a divalent alcoholic hydroxyl group represented by any of the following general formulae (II) to (IV).

[ solution 10]

HO-(CH₂)_n1-Q₁-(CH₂)_n1-OH…(II)

HO-(CH₂)_n2-Q₂-(CH₂)_n2-OH…(III)

HO-(CH₂)_n3-Q₃-(CH₂)_n3-OH…(IV)

In the above general formula (II), Q₁The hydrocarbon group has 6 to 40 carbon atoms and preferably 6 to 30 carbon atoms. n1 represents an integer of 1to 10, preferably an integer of 1to 4. Examples of the aromatic ring include phenyl, biphenyl, fluorenyl, naphthyl and the like.

In the above general formula (III), Q₂The hydrocarbon group has 6 to 40 carbon atoms and is preferably a linear or branched hydrocarbon group having 6 to 30 carbon atoms and may contain a heterocycle. n2 represents an integer of 1to 10, preferably an integer of 1to 4.

In the above general formula (IV), Q₃The hydrocarbon group is a C6-40 cyclic hydrocarbon group (cycloalkylene group), preferably a C6-30 cyclic hydrocarbon group. n3 represents an integer of 0to 10, preferably 1to 4. Examples of the cycloalkylene group include cyclohexyl, bicyclodecyl, and tricyclodecyl.

Among the compounds represented by any of the above general formulae (II) to (IV), the compound represented by the general formula (II) is particularly preferable.

Specific examples of the aliphatic diol compound usable in the present invention include linear aliphatic diols such as 1, 10-decanediol, 1, 12-dodecanediol, 1, 18-octadecanediol, 1, 20-eicosanediol and 1, 22-docosanediol; 1, 4-cyclohexanediol, 1, 4-cyclohexanedimethanol, tricycles (5.2.1.0)^2.6) Aliphatic diols having a cyclic structure such as decane dimethanol, decalin-2, 6-dimethanol, pentacyclopentadecane dimethanol, isosorbide and isomannide; compounds represented by the following formula (4) are classified into spiroglycols (in the following formula (4), R₅、R₆、R₇、R₈A hydrogen atom or a C1-10 alkyl group);

[ solution 11]

Specific examples thereof include naphthalenedimethanol, biphenyldimethanol, 1, 4-bis (2-hydroxyethoxy) phenyl, 4 '-bis (2-hydroxyethoxy) biphenyl, 2' -bis [ (2-hydroxyethoxy) phenyl ] propane, 9-bis [4- (2-hydroxyethoxy) phenyl ] fluorene, 9-bis (hydroxymethyl) fluorene, 9-bis (hydroxyethyl) fluorene, fluorenediol, and aromatic ring-containing aliphatic diols such as "NFAL-PE" and "BPAL-PE" represented by the following formulae.

[ solution 12]

Among these, decahydronaphthalene-2, 6-dimethanol, pentacyclopentadecane dimethanol, 4 '-bis (2-hydroxyethoxy) biphenyl, 2' -bis [ (2-hydroxyethoxy) phenyl ] propane, 9-bis [4- (2-hydroxyethoxy) phenyl ] fluorene, fluorenediol, and fluorenediethanol are most preferably used. These may be used alone or in combination of two or more.

The kind of the compound to be used for the aliphatic diol compound to be actually used may vary depending on the reaction conditions and the like.

The reaction for increasing the molecular weight by linking an aliphatic diol compound is exemplified by a specific reaction scheme.

[ solution 13]

In the above reaction scheme, the aromatic monohydroxy compound represented by "HO-R" can be removed by conducting the reaction under reduced pressure. This can increase the molecular weight of the polymer.

The amount of the aliphatic diol compound used in the present invention is preferably 0.01to 1.0 mol, more preferably 0.1to 1.0 mol, further preferably 0.1to 0.5 mol, and particularly preferably 0.2 to 0.4 mol, based on 1 mol of the total terminal groups of the aromatic polycarbonate before the polymerization reaction.

When the amount of the aliphatic diol compound used is large and exceeds the above range, the aliphatic diol compound undergoes an insertion reaction into the main chain of the aromatic polycarbonate resin as a copolymerization component, and the copolymerization ratio increases, so that the influence of the physical properties of the copolymerization increases. Although the improvement of physical properties can be achieved by this, it is not preferable as an effect of increasing the molecular weight of the aromatic polycarbonate. When the amount is less than the above range, the effect of increasing the molecular weight is small, which is not preferable.

In the present specification, "total terminal group amount of polycarbonate" or "total terminal group amount of polymer", for example, in the case of polycarbonate (or chain polymer) having no branch, since the number of terminal groups per 1 molecule is 2, if the amount of polycarbonate having no branch is 0.5 mole, the total terminal group amount is calculated to be 1 mole. In the case of polycarbonates having branched chains, the terminal groups of the branched chains are also included in the total amount of terminal groups. The total terminal amount of such terminal groups having a branched chain is calculated by NMR measurement, calculation of molecular weight, introduction amount of a branching agent, or the like.

It is preferable that the amount of chlorine, nitrogen, alkali metal, and heavy metal contained as impurities in these aliphatic diol compounds is small. The alkali metal refers to sodium, potassium, and salts and derivatives thereof, and the heavy metal refers to iron, nickel, and chromium.

The content of these impurities is preferably 1000ppm or less as chlorine, 100ppm or less as nitrogen, 10ppm or less as alkali metal, 3ppm or less as iron, 2ppm or less as nickel, and 1ppm or less as chromium in heavy metal.

(3) High molecular weight reaction

The high molecular weight reaction in the high molecular weight step of the method of the present invention is an ester exchange reaction. As the catalyst used in the transesterification reaction (the high molecular weight reaction of the present invention), a basic compound catalyst and a transesterification catalyst which are generally used as a catalyst for producing a polycarbonate can be used.

The basic compound catalyst may include, in particular, an alkali metal compound and/or an alkaline earth metal compound, a nitrogen-containing compound, and the like.

As the alkali metal compound and/or the alkaline earth metal compound, organic acid salts, inorganic salts, oxides, hydroxides, hydrides or alkoxides of alkali metals and alkaline earth metals, ammonium hydroxide and salts thereof, amines, and the like are preferably used, and these compounds may be used alone or in combination.

Specific examples of the alkali metal compound include sodium hydroxide, potassium hydroxide, cesium hydroxide, lithium hydroxide, sodium hydrogen carbonate, sodium carbonate, potassium carbonate, cesium carbonate, lithium carbonate, sodium acetate, potassium acetate, cesium acetate, lithium acetate, sodium stearate, potassium stearate, cesium stearate, lithium stearate, sodium borohydride, sodium phenylboronate, sodium benzoate, potassium benzoate, cesium benzoate, lithium benzoate, disodium hydrogenphosphate, dipotassium hydrogenphosphate, dilithium hydrogenphosphate, disodium phenylphosphate, disodium salt of bisphenol a, dipotassium salt, dicesium salt, dilithium salt, sodium salt, potassium salt, cesium salt, and lithium salt of phenol.

Specific examples of the alkaline earth metal compound include magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, magnesium hydrogencarbonate, calcium hydrogencarbonate, strontium hydrogencarbonate, barium hydrogencarbonate, magnesium carbonate, calcium carbonate, strontium carbonate, barium carbonate, magnesium acetate, calcium acetate, strontium acetate, barium acetate, magnesium stearate, calcium benzoate, magnesium phenylphosphate, and the like.

Specific examples of the nitrogen-containing compound include ammonium hydroxides having an alkyl group and/or an aryl group, such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and trimethylbenzylammonium hydroxide; tertiary amines such as triethylamine, dimethylbenzylamine, and triphenylamine; secondary amines such as diethylamine and dibutylamine; primary amines such as propylamine and butylamine; imidazoles such as 2-methylimidazole, 2-phenylimidazole and benzimidazole; and alkali or basic salts such as ammonia, tetramethylammonium borohydride, tetrabutylammonium tetraphenylborate, and tetraphenylammonium tetraphenylborate.

As the transesterification catalyst, salts of zinc, tin, zirconium and lead are preferably used, and they may be used alone or in combination.

Specific examples of the transesterification catalyst include zinc acetate, zinc benzoate, zinc 2-ethylhexanoate, tin (II) chloride, tin (IV) chloride, tin (II) acetate, tin (IV) acetate, dibutyl tin dilaurate, dibutyl tin oxide, dibutyl tin dimethoxide, zirconium acetylacetonate, zirconium oxyacetate, tetrabutoxyzirconium, lead (II) acetate, and lead (IV) acetate.

These catalysts are used in an amount of 1X 10to 1 mol based on the total amount of dihydroxy compounds^-9～1×10^-3The molar ratio is preferably 1X 10^-7～1×10^-5Molar ratios were used.

The reaction temperature in the reaction for increasing the molecular weight of the aliphatic diol compound (linkage reaction) is preferably in the range of 240 to 320 ℃, more preferably 260 to 310 ℃, and particularly preferably 270 to 300 ℃.

The degree of pressure reduction is preferably 13kPaA (100torr) or less, more preferably 1.3kPaA (10torr) or less, and still more preferably 0.67 to 0.013kPaA (5 to 0.1 torr). When the reaction for increasing the molecular weight is carried out under normal pressure, the polymer may be reduced in molecular weight.

By using these aliphatic diol compounds, the weight average molecular weight (Mw) of the aromatic polycarbonate resin after the high molecular weight reaction can be increased by 5,000 or more as compared with the weight average molecular weight (Mw) of the aromatic polycarbonate resin before the high molecular weight reaction. More preferably, it is increased by 10,000 or more, and still more preferably, it is increased by 15,000 or more.

The weight average molecular weight (Mw) of the aromatic polycarbonate resin having a high molecular weight obtained by the method of the present invention is not particularly limited, but is preferably 30,000 to 100,000, more preferably 30,000 to 80,000.

The type of apparatus and the material of the reactor used in the high molecular weight reaction may be any known type and material, and may be carried out continuously or batchwise. The reaction apparatus used for carrying out the reaction may be a vertical reaction apparatus equipped with an anchor-type stirring blade, a maximum mixing (Maxblend) stirring blade, a ribbon-type stirring blade, or the like, a horizontal reaction apparatus equipped with a blade, a lattice blade, a spectacle blade, or the like, an extruder-type reaction apparatus equipped with a screw, and is preferably carried out: a reaction apparatus in which these are appropriately combined in consideration of the viscosity of the polymer is used. Preferably, the apparatus is an apparatus having a screw with good horizontal stirring efficiency and a unit capable of performing under reduced pressure.

It is further preferred to use a twin-screw extruder or a horizontal reactor with a polymer seal, with a curved structure.

As the material of the device, stainless steel such as SUS310, SUS316, and SUS304, nickel, iron nitride, and the like are preferable, which do not affect the color tone of the polymer. Further, the inside of the apparatus (the portion in contact with the polymer) may be subjected to burnishing, electropolishing, or metal plating treatment with chromium or the like.

In the present invention, a deactivator of a catalyst can be used for a polymer having an increased molecular weight in the above-mentioned high molecular weight reaction. In general, a method of deactivating the catalyst by adding a known acidic substance is preferably carried out. As these, specifically, aromatic sulfonic acids such as p-toluenesulfonic acid, aromatic sulfonic esters such as butyl p-toluenesulfonic acid, and the like; organic halides such as stearoyl chloride, butyryl chloride, benzoyl chloride, tosyl chloride; alkyl sulfates such as dimethyl sulfate; such as benzyl chloride and the like.

After the catalyst is deactivated, a step of removing low boiling point compounds in the polymer by devolatilization at a pressure of 0.013 to 0.13kPaA (0.1 to 1torr) and a temperature of 200 to 350 ℃ may be provided, and for this purpose, a horizontal type apparatus or a thin film evaporator having stirring fins excellent in surface renewal performance such as blade fins, lattice fins, and spectacle fins may be preferably used.

Further, in the present invention, in addition to the above heat stabilizer, an antioxidant, a pigment, a dye enhancer, a filler, an ultraviolet absorber, a lubricant, a mold release agent, a crystal nucleating agent, a plasticizer, a fluidity improving material, an antistatic agent, and the like may be added.

These additives can be used in the conventional methods to mix the components in the polycarbonate resin. For example, a method of dispersing and mixing the respective components by a high-speed mixer such as a drum mixer, a henschel mixer, a ribbon mixer, or a super mixer (super mixer), and then melt-kneading the components by an extruder, an internal mixer, or a roll can be suitably selected.

The polycarbonate disclosed by the present invention can be preferably used in applications such as various molded articles, sheets, films and the like obtained by injection molding, blow molding, extrusion molding, injection blow molding, rotational molding, compression molding and the like. When used in these applications, the polycarbonate obtained in the present invention may be used alone or as a blend with other polymers. Processing such as hard coating, lamination, and the like may also be preferably used depending on the use.

Specific examples of the molded article include optical media articles such as a compact disk, a digital versatile disk, a mini disk, and a magneto-optical disk; optical communication media such as optical fibers; optical components such as a headlight lens for a vehicle or the like and a lens body for a camera or the like; optical equipment parts such as a traffic light cover and an illumination light cover; window glass substitutes for electric cars, automobiles, and the like, and window glass substitutes for household use; skylight, roof of greenhouse, etc; goggles, sunglasses, lenses for glasses, and frames; electronic parts such as housings of OA equipment such as copying machines, facsimiles, and personal computers, housings of home electric appliances such as televisions and microwave ovens, connectors, and IC trays; protective devices such as safety helmets, protective gear, protective masks, and the like; tableware such as trays; medical products such as a dialyzer shell and a denture, but the present invention is not limited thereto.

Examples

The present invention will be described below with reference to examples, but the present invention is not limited to these examples. The measurement values in the examples were measured by the following methods and apparatuses.

1) Polystyrene-reduced weight average molecular weight (Mw): a calibration curve was prepared using GPC with tetrahydrofuran as a developing solvent and standard polystyrene of known molecular weight (molecular weight distribution = 1). Based on the calibration curve, the retention time of GPC was calculated.

2) Glass transition temperature (Tg): the measurement was performed by a Differential Scanning Calorimeter (DSC).

3) Total terminal group amount (number of moles) of polymer: 0.25g of the resin sample was dissolved in 5ml of heavy hydrogen-substituted chloroform, and the mixture was analyzed at 23 ℃ using a nuclear magnetic resonance analyzer¹The terminal group was measured by H-NMR (trade name "LA-500" manufactured by Nippon spectral Co., Ltd.) and expressed in terms of the number of moles per 1ton of the polymer.

4) Hydroxyl end concentration (ppm): determined by UV/visible spectroscopy (546nm) of a complex formed from the polymer and titanium tetrachloride in dichloromethane solution.

5) Resin hue (YI value): a resin sample (4 g) was dissolved in 25ml of methylene chloride, and the YI value was measured using a spectroscopic colorimeter (trade name "SE-2000" manufactured by Nippon Denshoku industries Co., Ltd.).

< examples 1 and 2>

Bisphenol A and diphenyl carbonate (1.1 mol of diphenyl carbonate relative to 1 mol of bisphenol A) and sodium hydrogencarbonate (NaHCO) were used₃) The catalyst was prepared by melt polymerization.

That is, 10.00kg (43.8 mol) of 2, 2-bis (4-hydroxyphenyl) propane, 10.56kg (49.3 mol) of diphenyl carbonate and 1. mu. mol/mol of sodium hydrogencarbonate as a catalyst were charged into a 50L reactor equipped with a stirrer and a distillation apparatus and equipped with a heating means for SUS316, heated at 180 ℃ under a nitrogen atmosphere, melted and stirred for 30 minutes.

Then, the pressure was adjusted to 20kPaA (150torr), and the temperature was raised to 200 ℃ at a rate of 60 ℃/hr, and the temperature was maintained for 40 minutes to perform the transesterification reaction. Then, the temperature was raised to 225 ℃ at a rate of 75 ℃/hr, and the temperature was maintained at this temperature for 15 minutes. Subsequently, the temperature was raised to 260 ℃ at a rate of 65 ℃/hr, and the reduced pressure was reduced to 0.13kPaA (1torr) or less for 1 hour to obtain a weight average molecular weight (Mw): 31,000, 256mol of total terminal groups and 400ppm of hydroxyl terminal concentration (10 kg).

Using 200g of the aromatic polycarbonate pellets obtained by the above-mentioned method, it was charged into a1,000 ml SUS316L kneader (equipped with an oil heating jacket) together with the kind and amount of the aliphatic diol compound shown in Table 1. The catalyst for the high molecular weight reaction is a polymerization catalyst (NaHCO) used in the polymerization of the aromatic polycarbonate (before the linking treatment)₃)。

The resulting mixture was kneaded at a jacket temperature of 290 ℃ under a pressure of 0.04kPaA (0.3torr) for 30 minutes. Phenol distilled out of the reaction system was condensed in a condenser tube and removed from the reaction system. The obtained aromatic polycarbonate resin was taken out and the weight average molecular weight was measured. The physical property values of the obtained polymer are shown in table 1.

< examples 3to 7>

In the same manner as in example 1, bisphenol A and diphenyl carbonate (1.1 mol of diphenyl carbonate was used relative to 1 mol of bisphenol A) were reacted with sodium hydrogencarbonate (NaHCO)₃) Weight average molecular weight (Mw) prepared by melt polymerization using 1. mu. mol/mol as a catalyst: 30g of pellets of 31,000 aromatic polycarbonate having a total terminal group amount of 256mol and a hydroxyl group terminal concentration of 400ppm were charged into a 300cc four-necked flask equipped with a stirrer and a distillation apparatus (equipped with an oil bath). The catalyst for the high molecular weight reaction is a polymerization catalyst (NaHCO) used in the polymerization of the aromatic polycarbonate (before the linking treatment)₃)。

It was heated to melt at an oil bath temperature of 290 ℃ under vacuum. Next, the aliphatic diol compounds of the types and amounts shown in Table 1 were charged, and the mixture was kneaded for 30 minutes under an oil bath temperature of 290 ℃ and a pressure of 0.04kPaA (0.3 torr). Phenol distilled out of the reaction system was condensed by a condenser and removed from the reaction system. The obtained aromatic polycarbonate resin was taken out and the weight average molecular weight was measured. The physical property values of the obtained polymer are shown in table 1.

< examples 8 and 9>

The weight average molecular weight (Mw) prepared from bisphenol A and phosgene by interfacial polymerization method: 32,000, using end-capping reagent: p-tert-butylphenol, total terminal group amount: 253mol, hydroxyl end concentration: 200g of 200ppm aromatic polycarbonate sheet, aliphatic diol compound of the type and amount shown in Table 1, and catalyst (NaHCO)₃) Mu. mol/mol (calculated as moles relative to BPA units) was charged into a1,000 ml SUS316L kneader (equipped with an oil heating jacket).

The resulting mixture was kneaded at a jacket temperature of 290 ℃ under a pressure of 0.04kPaA (0.3torr) for 30 minutes. The p-tert-butylphenol distilled off from the reaction system was condensed by a cooling tube and removed from the reaction system. The obtained aromatic polycarbonate resin was taken out and the weight average molecular weight was measured. The physical property values of the obtained polymer are shown in table 1.

< comparative example 1>

45.6g (0.20 mol) of 2, 2-bis (4-hydroxyphenyl) propane, 43.3g (0.202 mol) of diphenyl carbonate and 1. mu. mol/mol (in terms of the number of moles per BPA unit) of sodium hydrogencarbonate as a catalyst were charged in a 300cc four-necked flask equipped with a stirrer and a distillation apparatus, heated at 180 ℃ under a nitrogen atmosphere and stirred for 30 minutes.

Then, the ester exchange reaction was carried out by adjusting the reduced pressure to 20kPaA (150torr), raising the temperature to 200 ℃ at a rate of 60 ℃/hr, and maintaining the temperature for 40 minutes. Then, the temperature was raised to 225 ℃ at a rate of 75 ℃/hr, and the temperature was maintained at this temperature for 10 minutes. Then, the temperature was raised to 290 ℃ at a rate of 65 ℃/hr, and the reduced pressure was reduced to 0.13kPaA (1torr) or less over 1 hour. The reaction was carried out with stirring for 6 hours in total to carry out polymerization. After the latter half of the polymerization, the viscosity became high, phenol was difficult to remove, and the molecular weight increase became very slow. The molecular weight increase to the same extent takes up to 6 hours, with significant coloration. The physical property values of the obtained polymer are shown in table 2.

< comparative example 2>

The procedure of example 1 was repeated except that the diol compound was not used. The physical property values of the obtained polymer are shown in table 2.

< comparative example 3>

The reaction was carried out in the same manner as in example 1 except that the pressure was changed to normal pressure. The physical property values of the obtained polymer are shown in table 2.

< comparative example 4>

The procedure of example 8 was repeated except that the diol compound was not used. The physical property values of the obtained polymer are shown in table 2.

< comparative example 5>

The reaction was carried out in the same manner as in example 8 except that the pressure was changed to normal pressure. The physical property values of the obtained polymer are shown in table 2.

< comparative example 6>

The procedure of example 1 was repeated except that 2, 2-bis (4-hydroxyphenyl) propane (boiling point: 420 ℃ C., hereinafter abbreviated as "BPA") as an aromatic diol was used as the diol compound. The physical property values of the obtained polymer are shown in table 2.

< comparative example 7>

The procedure of example 8 was repeated except that BPA, which is an aromatic diol, was used as the diol compound. The physical property values of the obtained polymer are shown in table 2.

< comparative example 8>

The procedure of example 1 was repeated except that 1.1g (boiling point: 228 ℃ C., hereinafter abbreviated as "BD") of 1, 4-dibutanol, which is a low boiling aliphatic diol, was used as the diol compound. The physical property values of the obtained polymer are shown in table 2.

< comparative example 9>

The procedure of example 1 was repeated except that 1.3g of neopentyl glycol (boiling point: 211 ℃ C., hereinafter abbreviated as "NPG") as a diol compound, which is a low-boiling aliphatic diol, was used. The physical property values of the obtained polymer are shown in table 2.

< comparative example 10>

The reaction was carried out in the same manner as in example 8 except that npg1.3g was used as the diol compound. The physical property values of the obtained polymer are shown in table 2.

< examples 10 and 11>

The procedure of example 1 was repeated except that the kinds and amounts of the substances shown in table 3 were charged as diol compounds. The physical property values of the obtained polymer are shown in table 3.

< examples 12 and 13>

The procedure of example 3 was repeated except that the kinds and amounts of the materials shown in table 3 were charged as diol compounds. The physical property values of the obtained polymer are shown in table 3.

The diol compounds used are as follows.

And BPEF: 9, 9-bis [4- (2-hydroxyethoxy) phenyl ] fluorene (boiling point: about 625 deg.C)

BP-2 EO: 4, 4' -bis (2-hydroxyethoxy) biphenyl (boiling point: about 430 ℃ C.)

BPA-2 EO: 2, 2' -bis [ (2-hydroxyethoxy) phenyl ] propane (boiling point: about 480 ℃ C.)

FG: fluorene diol (boiling point: about 370 ℃ C.)

PCPDM: pentacyclopentadecane dimethanol (boiling point: about 420 ℃ C.)

CHDM: cyclohexane-1, 4-dimethanol (boiling point: about 280 ℃ C.)

DDM: decahydronaphthalene-2, 6-dimethanol (boiling point: about 341 ℃ C.)

BD: 1, 4-butane diol (boiling point: 228 ℃ C.)

NPG: neopentyl glycol (boiling point: 211 ℃ C.)

FE: fluorene diethanol (boiling point: about 410 ℃ C.)

[ Table 3]

TABLE 3

1) same as in tables 1 and 2

FE: fluorene diethanol (boiling point: about 410 ℃ C.)

As is clear from the above examples, the polycarbonate resin obtained by the method of the present invention has a low YI value and a good hue. In addition, the Tg shows a value almost equivalent to that of a BPA homopolymer having the same degree of molecular weight. This result shows that, by using the method of the present invention, a polycarbonate resin having physical properties equivalent to those of a high-molecular-weight BPA homopolymer, which has been difficult to produce by a conventional melt method, can be easily obtained by a melt method excellent in safety and environmental performance.

Availability on production

The present invention provides a process for producing an aromatic polycarbonate having a high molecular weight under mild conditions and in a short treatment time.

Claims (13)

1. A method for producing an aromatic polycarbonate resin having a high molecular weight, comprising the following high molecular weight production step: an aromatic polycarbonate and a diol compound represented by the following general formula (I) having a boiling point of 240 ℃ or higher are linked by an ester interchange reaction in the presence of an ester interchange catalyst under a reduced pressure of 13kPaA to 0.01kPaA at a temperature of 240 ℃ to 320 ℃ to increase the molecular weight,

[ solution 1]

HO-(CH₂)_n-Q-(CH₂)n-OH…(I)

Wherein Q represents a C6-40 hydrocarbon group which may contain an aromatic ring, and n represents an integer of 0-10; wherein n represents an integer of 1to 10 when Q does not contain an aliphatic hydrocarbon group.

2. The production process according to claim 1, wherein the diol compound is a compound represented by any of the following general formulae (II) to (IV),

[ solution 2]

HO-(CH₂)_n1-Q₁-(CH₂)_n1-OH…(II)

HO-(CH₂)_n2-Q₂-(CH₂)_n2-OH…(III)

HO-(CH₂)_n3-Q₃-(CH₂)_n3-OH…(IV)

In the above general formula (II), Q₁A C6-40 hydrocarbon group containing an aromatic ring; n1 represents an integer of 1to 10,

in the above general formula (III), Q₂Represents a straight-chain or branched-chain hydrocarbon group having 6 to 40 carbon atoms which may contain a heterocycle; n2 represents an integer of 1to 10,

in the above general formula (IV), Q₃A cyclic hydrocarbon group having 6 to 40 carbon atoms; n3 represents an integer of 0to 10.

3. The production method according to claim 2, wherein the diol compound is a compound represented by the following general formula (II),

[ solution 3]

HO-(CH₂)_n1-Q_l-(CH₂)_n1-OH…(II)

In the above general formula (II), Q₁A C6-40 hydrocarbon group containing an aromatic ring; n1 represents an integer of 1to 10.

4. The method according to claim 3, wherein the diol compound is selected from the group consisting of 4,4 '-bis (2-hydroxyethoxy) biphenyl, 2' -bis [ (2-hydroxyethoxy) phenyl ] propane, 9-bis [4- (2-hydroxyethoxy) phenyl ] fluorene, fluorenediol, and fluorenyldiethanol.

5. The production process according to claim 1, wherein the amount of the diol compound added is 0.01to 1.0 mol based on 1 mol of the total amount of the terminal ends of the aromatic polycarbonate before the ester interchange reaction in the high molecular weight step.

6. The production method according to claim 1, wherein at least a part of the aromatic polycarbonate before the ester interchange reaction in the step of increasing the molecular weight is end-capped.

7. The production process according to claim 6, wherein the aromatic polycarbonate before the ester interchange reaction is a prepolymer having blocked ends obtained by a reaction of an aromatic dihydroxy compound and a carbonic acid diester.

8. The production method according to claim 6, wherein the concentration of the hydroxyl terminal group of the aromatic polycarbonate before the ester interchange reaction in the step of increasing the molecular weight is 1,500ppm or less.

9. The production method according to claim 1, wherein the weight average molecular weight (Mw) of the aromatic polycarbonate having been subjected to the high molecular weight conversion in the high molecular weight conversion step after the transesterification reaction is higher by 5,000 or more than the weight average molecular weight (Mw) of the aromatic polycarbonate before the transesterification reaction.

10. The production method according to claim 1, wherein the weight average molecular weight (Mw) of the aromatic polycarbonate before the transesterification in the high molecular weight increasing step is 5,000 to 60,000.

11. The manufacturing method according to claim 1, comprising the steps of: a prepolymer production step of producing a prepolymer having a blocked end by reacting an aromatic dihydroxy compound with a carbonic acid diester; and a high molecular weight increasing step of connecting the terminal-blocked prepolymer to a diol compound having a boiling point of 240 ℃ or higher by transesterification in the presence of a transesterification catalyst under reduced pressure to increase the molecular weight.

12. An aromatic polycarbonate resin having a high molecular weight, which is obtained by the production method according to any one of claims 1to 11.

13. The aromatic polycarbonate resin having a high molecular weight according to claim 12, wherein the weight average molecular weight (Mw) is 30,000 to 100,000.