JP2009108138A - Production method of polycarbonate resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a production method of a polycarbonate resin capable of obtaining a polymer having a high molecular weight and an excellent mechanical strength. <P>SOLUTION: This production method of the polycarbonate resin is characterized in that during the polymerization of a cyclic polycarbonate oligomer, as a polymerization catalyst, a triaryl phosphonium salt having a structure represented by general Formula 1: (wherein R<SP>1</SP>represents a hydrogen atom, an alkyl group, an alkoxy group or a phenyl group; R<SP>2</SP>represents an alkyl group; and X represents a halogen group), is used in an amount of 0.6 mol% or more, based on the amount of a carbonate bond in the cyclic polycarbonate oligomer. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a polycarbonate resin, and more particularly to a method for producing a polycarbonate resin by polymerization of a cyclic polycarbonate oligomer.

Polycarbonate resins have many excellent properties such as extremely high transparency, heat resistance, mechanical strength and impact resistance, and are used in a large amount in a wide range of fields. Specific examples include various machine parts, various electrical insulating materials, automobile parts, information equipment materials such as optical disks, and safety protection materials such as helmets.
Regarding such a polycarbonate resin, Patent Document 1 proposes a method of introducing a flexible chain into a part of the structure of the polycarbonate resin.
Non-Patent Document 1 describes a method for producing a polycarbonate resin in which a cyclic polycarbonate oligomer is polymerized using methyltriphenylphosphonium bromide, butyltriphenylphosphonium bromide, or the like as a polymerization catalyst.

US Pat. No. 4,216,305 Journal of Applied Polymer Science No. 61, 1996, p. 1017-1023

By the way, compared with other thermoplastic resins for injection molding, the polycarbonate resin has a drawback that it has poor meltability because of its high melt viscosity and low fluidity. As a solution to this problem, a method using a polycarbonate having a low degree of polymerization has been proposed, but there is a problem that impact resistance is lowered.
On the other hand, when a flexible chain is introduced into a part of the structure of the polycarbonate resin, although the fluidity is improved to some extent, there is a problem that the heat resistance is lowered.
Moreover, when polymerizing a cyclic polycarbonate oligomer using methyltriphenylphosphonium bromide, butyltriphenylphosphonium bromide or the like as a polymerization catalyst, there is a problem in actual use because stirring is required during the polymerization reaction.

  The present invention has been made to solve the above problems. That is, an object of the present invention is to provide a method for producing a polycarbonate resin from which a polymer having a high molecular weight and excellent mechanical strength can be obtained.

Thus, according to the present invention, there is provided a method for producing a polycarbonate resin using a cyclic polycarbonate oligomer as a raw material. On the other hand, a method for producing a polycarbonate resin characterized by being used in an amount of 0.6 mol% or more is provided.
Here, it is preferable that the triarylphosphonium salt used as a polymerization catalyst in the method for producing a polycarbonate resin to which the present invention is applied has a structure represented by the following general formula 1.

(In General Formula 1, R ¹ represents a hydrogen atom, an alkyl group, an alkoxy group, or a phenyl group, R ² represents an alkyl group, and X represents a halogen atom.)

The polymerization temperature for polymerizing the cyclic polycarbonate oligomer is preferably 150 ° C. or higher.
Furthermore, the viscosity average molecular weight of the polycarbonate resin obtained by polymerization of the cyclic polycarbonate oligomer is preferably 10,000 or more.

  According to the present invention, a polycarbonate resin having a high molecular weight and excellent mechanical strength is obtained by using a triarylphosphonium salt as a polymerization catalyst in an amount of 0.6 mol% or more based on the amount of carbonate bonds in the cyclic polycarbonate oligomer. can get.

  Hereinafter, embodiments of the present invention will be described in detail. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary.

(Cyclic polycarbonate oligomer)
In the method for producing a polycarbonate resin to which the present embodiment is applied, examples of the cyclic polycarbonate oligomer used as a raw material include those having a cyclic structure represented by the following general formula 2.

In General Formula 2, Y represents a single bond or a divalent group, and R ⁵ and R ⁶ each independently represent a hydrogen atom, an alkyl group, an aryl group, a halogen group, or an alkoxy group. a and b each independently represent an integer of 1 to 4; N is an integer of 2 to 1,000.
Here, considering the ease of production of bisphenol used when producing the cyclic polycarbonate oligomer represented by the general formula 2, in R ⁵ and R ⁶ , the alkyl group is an alkyl group having 1 to 10 carbon atoms. More preferably, it is C1-C8, Most preferably, it is C1-C2. A phenyl group and a naphthyl group are preferred as the aryl group. As the halogen group, a fluorine atom, a chlorine atom, a bromine atom and an iodine atom are preferable. As an alkoxy group, a methoxy group, an ethoxy group, and a butoxy group are preferable.
Y represents a single bond, —O—, —S—, —SO—, —SO ₂ —, —CO—, —CH ₂ —, —CH (CH ₃ ) —, —C (CH ₃ ) _2. -And cyclohexylene. Among these, a single bond, —O—, —CH ₂ —, —CH (CH ₃ ) —, —C (CH ₃ ) ₂ —, and cyclohexylene are preferable.

Specific examples of the dihydric phenol component used when producing the cyclic polycarbonate oligomer represented by the general formula 2 include the following.
For example, 4,4′-biphenol, bis (4-hydroxyphenyl) methane, (2-hydroxyphenyl) (4-hydroxyphenyl) methane, bis (2-hydroxyphenyl) methane, 1,1-bis (4-hydroxy) Phenyl) ethane, 2,2-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclohexane, bis (4-hydroxyphenyl) ketone, bis (4-hydroxyphenyl) ether, bis ( 4-hydroxy-3-methylphenyl) methane, 1,1-bis (4-hydroxy-3-methylphenyl) ethane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 1,1-bis (4-hydroxy-3-methylphenyl) cyclohexane, bis (4-hydroxy-3-methylphenyl) ) Ether, bis (4-hydroxy-3,5-dimethylphenyl) methane, 1,1-bis (4-hydroxy-3,5-dimethylphenyl) ethane, 2,2-bis (4-hydroxy-3,5) -Dimethylphenyl) propane, 1,1-bis (4-hydroxy-3,5-dimethylphenyl) cyclohexane, bis (4-hydroxyphenyl) phenylmethane, 1,1-bis (4-hydroxyphenyl) -1-phenyl Ethane and the like can be mentioned.

  Among these, 2,2-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 1,1 -Bis (4-hydroxyphenyl) -1-phenylethane is preferred. It is also possible to use a combination of a plurality of these dihydric phenol components.

(Production of cyclic polycarbonate oligomer)
As a method for producing the cyclic polycarbonate oligomer, a conventionally known method can be adopted and is not particularly limited. Usually, reaction time, reaction temperature, reaction concentration, amine catalyst amount, alkali metal hydroxide amount, water amount, reaction vessel agitation rate, addition concentration and addition rate of raw materials, type of solvent for extracting cyclic polycarbonate oligomer from solution after reaction By adjusting the concentration and the like, the yield of the cyclic polycarbonate oligomer and the molecular weight range of the cyclic polycarbonate oligomer can be variously changed.
As such a known method, for example, a method using 2,2-bis (4-hydroxyphenyl) propane as a raw material (Japanese Patent Publication No. 61-502132, J. Am. Chem. Soc., Vol. 112). , P2399-2402, (1990), Macromolecules vol.24, p3035-3044, (1991)).
Among these methods described above, a method of producing a cyclic polycarbonate oligomer using a polycarbonate oligomer having a phenolic hydroxyl group and a chloroformate group at the terminal (hereinafter referred to as “PCR-OG”) is preferable.

(Synthesis method of PCR-OG)
PCR-OG can be obtained by a conventionally known method. As a conventionally known method, for example, a method of introducing phosgene under these stirring conditions using an alkali metal hydroxide aqueous solution or an alkali metal hydroxide aqueous solution containing a dihydric phenol component and a water immiscible organic solvent described above. Is mentioned. At this time, phosgene is introduced as a gaseous, liquid or water-immiscible organic solvent solution.

Here, the water-immiscible organic solvent is an organic solvent that does not completely dissolve in water but can be separated at least partly from water to form two layers, and is used for the production of a normal polycarbonate resin. Organic solvents that can be used.
Examples of such water-immiscible organic solvents include dichloromethane, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, chloroform, carbon tetrachloride, monochlorobenzene, And halogenated hydrocarbons such as dichlorobenzene. Among these, dichloromethane is particularly preferable.

Here, the mixing ratio of water and the water immiscible organic solvent is usually in the range of (5/1) to (1/5) by volume ratio, and (3/1) to (1/3). A range is preferable.
Examples of the alkali metal hydroxide include sodium hydroxide and potassium hydroxide. The amount of alkali metal hydroxide used is preferably in the range of 1.01 to 3 equivalents of the phenolic hydroxyl group contained in the reaction system.

Phosgene is continuously introduced into the aqueous alkali metal hydroxide solution containing the dihydric phenol component for several minutes to several tens of minutes. The temperature of the reaction system at this time is kept in the range of 0 ° C to 40 ° C, preferably 0 ° C to 20 ° C.
In the synthesis of PCR-OG, a catalyst, a molecular weight control agent, a reducing agent, etc. can be used as necessary. By adding a catalyst, the synthesis reaction of PCR-OG is promoted. The molecular weight of PCR-OG is adjusted by adding a molecular weight control agent. Moreover, it is possible to suppress coloring by adding a reducing agent.

  Examples of the catalyst used for the synthesis of PCR-OG include known tertiary amines, quaternary ammonium salts, quaternary phosphonium salts, and the like. Specific examples of the tertiary amine include trimethylamine, triethylamine, tributylamine, tripropylamine, trihexylamine, pyridine, dimethylaniline and the like. Examples of quaternary ammonium salts or quaternary phosphonium salts include tertiary alkylamines such as tributylamine and trioctylamine, such as hydrochloric acid, bromic acid, iodic acid, benzyltriethylammonium chloride, benzyltrimethylammonium chloride, and benzyltributylammonium chloride. Tetraethylammonium chloride, tetrabutylammonium chloride, tetrabutylammonium bromide, trioctylmethylammonium chloride, tetrabutylphosphonium bromide, triethyloctadecylphosphonium bromide, N-laurylpyridinium chloride, laurylpicolinium chloride and the like.

A monohydric phenolic compound is mentioned as a molecular weight control agent used for the synthesis | combination of PCR-OG. Specific examples include, for example, phenol, o, m, p-cresol, o, m, p-ethylphenol, o, m, p-propylphenol, o, m, p-tert-butylphenol, pentylphenol, hexylphenol. Alkylphenols such as octylphenol, nonylphenol, 2,6-dimethylphenol derivatives and 2-methylphenol derivatives; monofunctional phenols such as o, m, p-phenylphenol and the like.
Moreover, as a reducing agent used for the synthesis | combination of PCR-OG, hydrosulfite sodium etc. are mentioned, for example.

  Thus, in the case of the synthesis method of PCR-OG using a dihydric phenol component and phosgene, PCR-OG of about a monomer to a 20-mer is obtained. Furthermore, since PCR-OG is obtained in a solution state of a water-immiscible organic solvent, this solution can be used as it is to produce a cyclic polycarbonate oligomer.

  The structure of the produced cyclic polycarbonate oligomer includes melting point measuring device, nuclear magnetic resonance device (NMR), high performance liquid chromatograph (HPLC), size exclusion chromatograph (SEC), mass spectrometer (MS), matrix assisted laser desorption. Analysis can be performed using a deionization time-of-flight mass spectrometer (MALDI-TOF MS) or the like.

(Polymerization of cyclic polycarbonate oligomer)
In the present embodiment, the above-described cyclic polycarbonate oligomer is used as a raw material, and a polycarbonate resin is produced by polymerizing the cyclic polycarbonate oligomer in the presence of a polymerization catalyst.
Here, examples of the method of mixing the cyclic polycarbonate oligomer and the polymerization catalyst include various methods such as a method of mixing without a solvent, a method of mixing using a solvent, and a method of mixing after heating and melting the cyclic polycarbonate oligomer. Is possible. Among these methods, as a method of mixing using a solvent, it is preferable to use a solvent in which both the cyclic polycarbonate oligomer and the polymerization catalyst are dissolved. Examples of such a solvent include dichloromethane, chloroform, tetrahydrofuran, toluene, xylene and the like.

  Examples of the polymerization method of the cyclic polycarbonate oligomer include a solid phase polymerization method, a solution polymerization method, and a melt polymerization method. Among these, the melt polymerization method is preferable. In the case of the melt polymerization method, the cyclic polycarbonate oligomer is melted and then poured into a mold or the like, polymerized and solidified to obtain a molded body.

In this Embodiment, the polymerization temperature of cyclic polycarbonate oligomer is 150 to 350 degreeC normally, Preferably it is 160 to 320 degreeC, More preferably, it is 180 to 300 degreeC. By carrying out the polymerization reaction of the cyclic polycarbonate oligomer in such a temperature range, a rapid polymerization reaction proceeds and a desired polycarbonate resin can be obtained.
When the polymerization temperature is excessively low, the polymerization reaction does not proceed easily, and it tends to be difficult to obtain a desired polycarbonate resin. On the other hand, when the polymerization temperature is excessively high, the decomposition reaction of the polycarbonate resin and the catalyst frequently occurs, and it tends to be difficult to obtain a desired polycarbonate resin.
In the present embodiment, polymerization may be performed under stirring conditions, or polymerization may be performed without stirring. Further, the polymerization time is preferably within 24 hours for the convenience of production.

  In the production method of the polycarbonate resin to which the present embodiment is applied, the viscosity average molecular weight of the polycarbonate resin obtained by polymerization of the cyclic polycarbonate oligomer is usually 10,000 or more, preferably 12,000 or more, more preferably 14, 000 or more. Here, when the viscosity average molecular weight of the polycarbonate resin is excessively low, the mechanical strength is inferior, and it tends to be difficult to obtain a desired polycarbonate resin.

In the polymerization of cyclic polycarbonate oligomers, other cyclic polycarbonate oligomers having different structures, cyclic carbonates, cyclic esters, cyclic amides, cyclic ethers, cyclic acetals, cyclic amines, cyclic sulfides, oxazoline derivatives, cyclic siloxanes, phosphorus-containing cyclic compounds , A ring-opening polymerizable compound such as epoxide, lactam, and lactone may be contained. Furthermore, you may contain the polymeric compound containing a vinyl group. Moreover, in order to introduce a crosslinked structure, a polyfunctional compound may be contained.
Furthermore, in order to improve the performance of the polycarbonate resin obtained by polymerization, the cyclic polycarbonate oligomer or the polycarbonate resin that is a polymer thereof may contain an inorganic substance, an organic substance, a naturally-derived compound, or the like.

(Polymerization catalyst)
Next, the polymerization catalyst will be described.
In the method for producing a polycarbonate resin to which the present embodiment is applied, a triarylphosphonium salt is used as a polymerization catalyst when the cyclic polycarbonate oligomer is polymerized.
Here, the triarylphosphonium salt includes a structure in which three aryl groups are bonded to a phosphorus atom, and further has a substituent such as a hydrogen atom, an alkyl group, an alkoxy group, or an aryl group bonded to the phosphorus atom. . In addition, an alkyl group, an alkoxy group, or a phenyl group may be further bonded to the aryl group bonded to the phosphorus atom.
Examples of the aryl group in the triarylphosphonium salt include a phenyl group, a naphthalene group, and a biphenyl group. Of these, a phenyl group is preferable.

  The phosphorus atom in the triarylphosphonium salt used in this embodiment is a positively charged cation, and also has a negatively charged anion as a counter ion. Here, the carbon number of the alkyl group bonded to the phosphorus atom and the alkyl group bonded to the aryl group bonded to the phosphorus atom is preferably 30 or less, and particularly preferably 20 or less. Similarly, the number of carbon atoms of the alkoxy group is preferably 30 or less, and particularly preferably 20 or less.

  Examples of the triarylphosphonium salt used in the present embodiment include a compound having a structure represented by the general formula 1.

In General Formula 1, R ¹ represents a hydrogen atom, an alkyl group, an alkoxy group, or a phenyl group, R ² represents an alkyl group, and X represents a halogen atom.
The alkyl group for R ¹ may have any structure of a chain structure, a branched structure, or a ring structure. As carbon number of an alkyl group, 30 or less are preferable and 20 or less are especially preferable. The number of carbon atoms of the alkoxy group in R ^1, preferably 30 or less, particularly preferably 20 or less. The carbon number of the alkyl group represented by R ² is preferably 30 or less, and particularly preferably 20 or less. Examples of the halogen atom represented by X include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a chlorine atom, a bromine atom and an iodine atom are preferred.

  Specific examples of the triarylphosphonium salt having a structure represented by the general formula 1 include, for example, methyltriphenylphosphonium chloride, methyltriphenylphosphonium bromide, methyltriphenylphosphonium iodide; ethyltriphenylphosphonium chloride, ethyltriphenyl. Phosphonium bromide, ethyltriphenylphosphonium iodide; propyltriphenylphosphonium chloride, propyltriphenylphosphonium bromide, propyltriphenylphosphonium iodide, isopropyltriphenylphosphonium iodide; butyltriphenylphosphonium chloride, butyltriphenylphosphonium bromide, butyltri Phenylphosphonium iodide; hexyltriphenylphosphonium chloride, hexyl Phenylphosphonium bromide, hexyltriphenylphosphonium iodide; heptyltriphenylphosphonium chloride, heptyltriphenylphosphonium bromide, heptyltriphenylphosphonium iodide; octyltriphenylphosphonium chloride, octyltriphenylphosphonium bromide, octyltriphenylphosphonium iodide, octyl Examples include triphenylphosphonium chloride, octyltriphenylphosphonium bromide, octyltriphenylphosphonium iodide; tetradecyltriphenylphosphonium chloride, tetradecyltriphenylphosphonium bromide, tetradecyltriphenylphosphonium iodide, and the like.

  Among these, methyltriphenylphosphonium bromide, methyltriphenylphosphonium iodide, ethyltriphenylphosphonium bromide, ethyltriphenylphosphonium iodide, propyltriphenylphosphonium bromide, isopropyltriphenylphosphonium iodide, butyltriphenylphosphonium bromide, hexyl Triphenylphosphonium bromide, heptyltriphenylphosphonium bromide, and tetradecyltriphenylphosphonium bromide are preferred.

In the present embodiment, the amount of the triarylphosphonium salt used as the polymerization catalyst for the cyclic polycarbonate oligomer is usually preferably 0.6 mol% or more, more preferably 0.7 mol% with respect to the carbonate bond amount of the cyclic polycarbonate oligomer. The above is more preferable. However, the amount of triarylphosphonium salt used is usually 50 mol% or less.
If the amount of the triarylphosphonium salt used is less than 0.6 mol%, the polymerization reaction does not proceed sufficiently, and a high-molecular-weight polycarbonate resin cannot be obtained.

  Hereinafter, the present invention will be described in more detail based on examples. In addition, this invention is not limited to an Example, unless contrary to the meaning. Further, “parts” in Examples and the like are in units of weight unless otherwise specified.

(Synthesis of PCR-OG)
According to the following operation, a polycarbonate oligomer (hereinafter referred to as “BPA-PCR-OG”) using 2,2-bis (4-hydroxyphenyl) propane and phosgene as raw materials was synthesized.
2,2-bis (4-hydroxyphenyl) propane 100 parts (0.438 mol), sodium hydroxide 45.6 parts (1.14 mol), water 848 parts, hydrosulfite sodium 0.336 parts and dichloromethane 432 parts ( 328 ml) was charged into a reaction vessel equipped with a stirrer and mixed with stirring. Next, 110 parts (1.111 mol) of phosgene was blown into the reaction vessel maintained at a temperature of 0 ° C. to 10 ° C. in about 6 hours, and 2,2-bis (4-hydroxyphenyl) propane, phosgene and The reaction was performed.

After completion of the reaction, a dichloromethane solution containing BPA-PCR-OG was collected. The analysis result of the obtained BPA-PCR-OG in dichloromethane solution was as follows.
-BPA-PCR-OG concentration: 26.4% by weight
・ Terminal chloroformate group concentration: 0.48 N ・ Terminal phenolic hydroxyl group concentration: 0.2 N In addition, the BPA-PCR-OG concentration was measured by evaporating a dichloromethane solution to dryness. The terminal chloroformate group concentration was measured by neutralizing and titrating aniline hydrochloride obtained by reacting BPA-PCR-OG with aniline with a 0.2 N aqueous sodium hydroxide solution. The terminal phenolic hydroxyl group concentration was colorimetrically determined at 546 nm for the color development of BPA-PCR-OG in dichloromethane, titanium tetrachloride and acetic acid solutions.

(Synthesis of cyclic polycarbonate oligomer)
To a beaker, 8.5 g (0.213 mol) of sodium hydroxide and 42.5 mL of water were added and stirred to prepare an aqueous sodium hydroxide solution. Next, 100 mL of dichloromethane and the above sodium hydroxide aqueous solution were added to the reaction vessel maintained at 30 ° C.
Subsequently, a solution in which 200 mL of dichloromethane was further added to 100 g of a BPA-PCR-OG dichloromethane solution prepared in advance as described above was prepared, and this was put into a dropping funnel. Moreover, the solution which added 40 mL of dichloromethane to 1.9 g (18.8 mmol) of triethylamine was prepared, and this was put into the dropping funnel different from the above.

Next, under stirring conditions, a dichloromethane solution of triethylamine was added to the reaction vessel in four portions every 10 minutes, and a dichloromethane solution of BPA-PCR-OG was added dropwise over 40 minutes. After completion of the dropwise addition of the BPA-PCR-OG dichloromethane solution, the mixture was stirred as it was for 2 minutes, then the stirring was stopped, and only the organic phase was taken out.
This organic phase was washed twice with 400 mL of 0.1N hydrochloric acid and twice with 400 mL of water, and then the organic phase was taken out. Subsequently, the organic phase was poured into 5 times volume of acetone, and unnecessary. A high molecular weight material, an acyclic product, and the like were deposited.
Next, unnecessary precipitates were filtered off, and the filtrate in which the target cyclic polycarbonate oligomer was dissolved was taken out, and then the solvent was distilled off to obtain 14.5 g of cyclic polycarbonate oligomer (yield 58%, white solid). ) Was isolated.
The structure of the obtained cyclic polycarbonate oligomer was analyzed using a nuclear magnetic resonance apparatus (NMR), a size exclusion chromatograph apparatus (SEC), and a matrix-assisted laser desorption / ionization time-of-flight mass spectrometer (MALDI-TOF MS). . Further, the obtained cyclic polycarbonate oligomer was a compound having a number average molecular weight of 500 to 1,000,000 and having the following structure.

(Polymerization catalyst for cyclic polycarbonate oligomer)
The polymerization catalyst shown below was used for the polymerization of the cyclic polycarbonate oligomer synthesized by the operation described above.
Catalyst A: Methyltriphenylphosphonium bromide catalyst B: n-butyltriphenylphosphonium bromide catalyst C: n-tetradecyltriphenylphosphonium bromide The structures of catalyst A, catalyst B, and catalyst C are shown below.

(Measurement of viscosity average molecular weight (Mv))
Using an Ubbelohde capillary viscometer (dichloromethane flow time t ₀ : 135.40 seconds), the flow time (t) of a polycarbonate resin dichloromethane solution (concentration: 6.00 g / L) at a temperature of 20.0 ° C. The viscosity average molecular weight (Mv) of the polycarbonate resin was calculated based on the following formula.

η _sp = (t / t ₀ ) −1
X = (0.2092 × η _sp ) +1.0734
Y = 100 × η _sp / C
C = 6.00 [g / L]
η = Y / X
Mv = 3207 × (η ^1.205 )

Example 1
The cyclic polycarbonate oligomer was polymerized by the following operation to produce a polycarbonate resin.
Into an Erlenmeyer flask, 0.2824 g (0.791 mmol) of the catalyst A described above and 100 mL of dichloromethane were added to prepare a solution in which the catalyst A was uniformly dissolved (hereinafter referred to as “catalyst A-100 solution”). .
Separately, 0.2 g of cyclic polycarbonate oligomer (carbonate bond amount: 0.791 mmol) was added to the test tube, and then 1 mL of Catalyst A-100 solution was added to the test tube to uniformly dissolve the cyclic polycarbonate oligomer. Here, 7.91 μmol of catalyst A is contained in 1 mL of catalyst A-100 solution. At this time, the amount of catalyst A with respect to the amount of carbonate bonds in the cyclic polycarbonate oligomer is 1 mol%.
Next, dichloromethane in the test tube was distilled off, and a white solid of a cyclic polycarbonate oligomer containing the catalyst A was obtained in the test tube. Subsequently, this test tube was placed in an oil bath maintained at a temperature of 240 ° C. and a temperature of 260 ° C., respectively, and a polymerization reaction was performed for 10 minutes without stirring to produce a polycarbonate resin. The viscosity average molecular weight (Mv) of the obtained polycarbonate resin is shown in Table 1.

(Example 2)
To the Erlenmeyer flask, 0.3157 g (0.791 mmol) of the catalyst B described above and 100 mL of dichloromethane were added to prepare a solution in which the catalyst B was uniformly dissolved (hereinafter referred to as “catalyst B-100 solution”). .
Except having used catalyst B-100 liquid instead of catalyst A-100 liquid of Example 1, operation similar to Example 1 was performed, the cyclic polycarbonate oligomer was polymerized, and polycarbonate resin was manufactured.
Here, in 1 mL of the catalyst B-100 solution, 7.91 μmol of catalyst B is contained. At this time, the amount of catalyst B relative to the amount of carbonate bonds in the cyclic polycarbonate oligomer is 1 mol%. The Mv measured for the obtained polycarbonate resin is shown in Table 1.

(Example 3)
Into an Erlenmeyer flask, 0.4266 g (0.791 mmol) of the catalyst C described above and 100 mL of dichloromethane were added to prepare a liquid in which the catalyst C was uniformly dissolved (hereinafter referred to as “catalyst C-100 liquid”). .
Except having used the catalyst C-100 liquid instead of the catalyst A-100 liquid of Example 1, operation similar to Example 1 was performed, the cyclic polycarbonate oligomer was polymerized, and the polycarbonate resin was manufactured.
Here, 7.91 μmol of catalyst C is contained in 1 mL of catalyst C-100 solution. At this time, the amount of catalyst C relative to the amount of carbonate bonds in the cyclic polycarbonate oligomer is 1 mol%. The Mv measured for the obtained polycarbonate resin is shown in Table 1.

(Comparative Example 1)
To the Erlenmeyer flask, 10 mL of the catalyst A-100 solution and 40 mL of dichloromethane were added and mixed uniformly (hereinafter referred to as “catalyst A-500 solution”).
A cyclic polycarbonate oligomer was polymerized to produce a polycarbonate resin, except that the catalyst A-500 solution was used instead of the catalyst A-100 solution of Example 1, and a cyclic polycarbonate oligomer was polymerized.
Here, 1.58 mol of catalyst A is contained in 1 mL of catalyst A-500 liquid. At this time, the amount of catalyst A relative to the amount of carbonate bonds of the cyclic polycarbonate oligomer is 0.2 mol%. The Mv measured for the obtained polycarbonate resin is shown in Table 1.

(Comparative Example 2)
To the Erlenmeyer flask, 10 mL of the catalyst A-100 solution and 10 mL of dichloromethane were added and mixed uniformly (hereinafter referred to as “catalyst A-200 solution”).
A cyclic polycarbonate oligomer was polymerized to produce a polycarbonate resin, except that the catalyst A-200 solution was used instead of the catalyst A-100 solution of Example 1, and a cyclic polycarbonate oligomer was polymerized.
Here, 3.96 μmol of catalyst A is contained in 1 mL of catalyst A-200 solution. At this time, the amount of catalyst A relative to the amount of carbonate bonds of the cyclic polycarbonate oligomer is 0.5 mol%. The Mv measured for the obtained polycarbonate resin is shown in Table 1.

From the results shown in Table 1, when the cyclic polycarbonate oligomer is polymerized, a triarylphosphonium salt is used as a polymerization catalyst in an amount of 0.6 mol% or more based on the carbonate bond amount of the cyclic polycarbonate oligomer (Examples 1 to Examples). 3) It turns out that the polycarbonate resin excellent in high molecular weight and mechanical strength is obtained.
On the other hand, when the triarylphosphonium salt is used as a polymerization catalyst in an amount of less than 0.6 mol% based on the carbonate bond amount of the cyclic polycarbonate oligomer (Comparative Example 1 to Comparative Example 2), the polymerization reaction does not proceed sufficiently, and the high molecular weight. It can be seen that no polymer is obtained.

Claims (4)

A method for producing a polycarbonate resin using a cyclic polycarbonate oligomer as a raw material,
When polymerizing the cyclic polycarbonate oligomer, a triarylphosphonium salt is used as a polymerization catalyst in an amount of 0.6 mol% or more with respect to the amount of carbonate bonds in the cyclic polycarbonate oligomer. . The method for producing a polycarbonate resin according to claim 1, wherein the triarylphosphonium salt has a structure represented by the following general formula 1.

(In General Formula 1, R ¹ represents a hydrogen atom, an alkyl group, an alkoxy group, or a phenyl group, R ² represents an alkyl group, and X represents a halogen atom.)   The method for producing a polycarbonate resin according to claim 1 or 2, wherein the polymerization temperature is 150 ° C or higher.   The method for producing a polycarbonate resin according to any one of claims 1 to 3, wherein the polycarbonate resin has a viscosity average molecular weight of 10,000 or more.