JPH06263865A - Production of polycarbonate copolymer - Google Patents

Abstract

PURPOSE:To produce easily and stably a polycarbonate copolymer containing siloxane units and having a high molecular weight. CONSTITUTION:This production process comprises reacting a bisphenol with a carbonic-ester-forming compound to form an oligomer terminated with a chloroformate group and based on oligomer component of a degree of polymerization of 2-4 and subjecting this oligomer and a bisphenol to an interfacial polycondensation reaction in a mixture of a water-insoluble organic solvent and an aqueous alkali solution. In the formulas, R<1> and R<2> are each halogen, alkyl, cycloalkyl or aryl; Y is a single bond, O, CO, S, SO2 or the like; R<5> to R<10> are each H, alkyl or aryl; R<11> and R<12> are each halogen, alkyl or aryl; (a) and (d) are each an integer of 0-4; X is alkylene; (n) is an integer of 1-6; (p) is a natural number; and (q) is 0 or a natural number.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polycarbonate copolymer containing a siloxane unit and having a high molecular weight, which is useful as a material for general industrial materials, particularly for electronic and electric equipment parts.

[0002]

2. Description of the Related Art Polycarbonate is used as an industrial material in various fields of application because it has excellent transparency and heat resistance. In particular, bisphenol A type polycarbonate is known to be useful as a binder resin in the photosensitive layer of an electrophotographic photoreceptor because it has good compatibility with a charge transport substance. However, as the field of use expands, demanded properties having higher performance than those of bisphenol A type polycarbonate which has been conventionally produced from bisphenol A or the like have been demanded. In response to such a demand, for example, in order to improve abrasion resistance, development of a polycarbonate copolymer using a dihydroxy compound containing a silicon atom as a comonomer in addition to bisphenols as a raw material is under way.

Such a polycarbonate copolymer is disclosed in European Patent Application Publication No. 0 500087 (1).
992), a dihydroxy compound having a long chain of dimethylsiloxane units is dissolved in an aqueous sodium hydroxide solution together with a bisphenol such as 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), and triethylamine is used as a catalyst for phosgene gas. Is introduced into a monomer solution and reacted. However, in such a production method, the solubility of the dihydroxy compound having a dimethylsiloxane unit in water is small and a uniform liquid phase cannot be formed, so that a polycarbonate copolymer having a sufficiently high molecular weight cannot be obtained. .

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to solve the problems in the production of the polycarbonate copolymer having a siloxane unit found in the above-mentioned prior art, and to easily and stably prepare a high molecular weight polycarbonate copolymer. The object of the present invention is to provide a manufacturing method that can be manufactured efficiently.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that when copolymerizing a bisphenol with a dihydroxy compound having a siloxane unit, the bisphenol After producing an oligomer, it was found that a high-molecular weight polycarbonate copolymer can be obtained by interfacial polycondensation using the oligomer and a dihydroxy compound having a siloxane unit as a homogeneous mixture, and based on this finding, The invention was completed.

That is, the present invention provides the following general formula (I)

[0007]

[Chemical 3] [Wherein, R ¹ and R ² are each independently a halogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 12 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms. And a and b are each independently an integer of 0 to 4, Y is a single bond, -O-, -CO-, -S-, -SO.
—, —SO ₂ —, —CR ³ R ⁴ — (wherein R ³ and R ⁴ are each independently a hydrogen atom, a trifluoromethyl group, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 5 to 12 carbon atoms. An alkyl group or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms), a 1,1-cycloalkylidene group having 5 to 8 carbon atoms or an α, ω-alkylene group having 2 to 12 carbon atoms. ] The dihydric phenol (I) represented by the following general formula (II)

[0008]

[Chemical 4] (In the formula, R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms. Group, R
¹¹ and R ¹² are each independently a halogen atom or a carbon number of 1 to 6.
Is an alkyl group or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, c and d are each independently an integer of 0 to 4, and X is a substituted or unsubstituted alkylene group having 1 to 6 carbon atoms. , N is an integer of 1 to 6, p is a natural number, q is 0 or a natural number, and p + q is a natural number less than 100. ) Dihydric phenol (I
When a polycarbonate copolymer is produced by reacting I) with an ester-forming compound, the dihydric phenol (I) is reacted with the ester-forming compound in advance to have a terminal chloroformate group. Two
To the dihydric phenol (II) and a solution of the dihydric phenol (II) in a water-insoluble organic solvent. An object of the present invention is to provide a method for producing a polycarbonate copolymer, which comprises performing interfacial polycondensation in a mixed solution with an alkaline aqueous solution.

Examples of the dihydric phenol (I) represented by the general formula (I) used in the method of the present invention include bis (4-hydroxyphenyl) methane and 1,1-bis (4).
-Hydroxyphenyl) ethane, 1,2-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (3-methyl-)
4-hydroxyphenyl) butane, 2,2-bis (4-
Hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) octane, 4,4-bis (4-hydroxyphenyl) heptane, 4,4′-dihydroxytetraphenylmethane, 1,1-bis (4-hydroxy) Phenyl) -1-phenylethane, 1,1-bis (4-hydroxyphenyl) -1-phenylmethane, bis (4-hydroxyphenyl) ether, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl)
Sulfone, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis (3-methyl-4-)
Hydroxyphenyl) propane, 2- (3-methyl-4)
-Hydroxyphenyl) -2- (4-hydroxyphenyl) -1-phenylethane, bis (3-methyl-4-hydroxyphenyl) sulfide, bis (3-methyl-4)
-Hydroxyphenyl) sulfone, bis (3-methyl-)
4-hydroxyphenyl) methane, 1,1-bis (3-
Methyl-4-hydroxyphenyl) cyclohexane,
2,2-bis (2-methyl-4-hydroxyphenyl)
Propane, 1,1-bis (2-butyl-4-hydroxy-5-methylphenyl) butane, 1,1-bis (2-t
ert-Butyl-4-hydroxy-3-methylphenyl) ethane, 1,1-bis (2-tert-butyl-4)
-Hydroxy-5-methylphenyl) propane, 1,1
-Bis (2-tert-butyl-4-hydroxy-5-
Methylphenyl) butane, 1,1-bis (2-tert)
-Butyl-4-hydroxy-5-methylphenyl) isobutane, 1,1-bis (2-tert-butyl-4-hydroxy-5-methylphenyl) heptane, 1,1-bis (2-tert-butyl-4) -Hydroxy-5-methylphenyl) -1-phenylmethane, 1,1-bis (2
-Tert-amyl-4-hydroxy-5-methylphenyl) butane, bis (3-chloro-4-hydroxyphenyl) methane, bis (3,5-dibromo-4-hydroxyphenyl) methane, 2,2-bis ( 3-chloro-4-
Hydroxyphenyl) propane, 2,2-bis (3-fluoro-4-hydroxyphenyl) propane, 2,2-
Bis (3-bromo-4-hydroxyphenyl) propane, 2,2-bis (3,5-difluoro-4-hydroxyphenyl) propane, 2,2-bis (3,5-dichloro-4-hydroxyphenyl) propane 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane, 2,2-bis (3-bromo-4-hydroxy-5)
Chlorophenyl) propane, 2,2-bis (3,5-dichloro-4-hydroxyphenyl) butane, 2,2-bis (3,5-dibromo-4-hydroxyphenyl) butane, 1-phenyl-1,1- Bis (3-fluoro-4-
Hydroxyphenyl) ethane, bis (3-fluoro-4)
-Hydroxyphenyl) ether, 1,1-bis (3-
Cyclohexyl-4-hydroxyphenyl) cyclohexane, 4,4'-dihydroxybiphenyl, 4,4'-
Dihydroxy-3,3'-dimethylbiphenyl, 4,
4'-dihydroxy-2,2'-dimethylbiphenyl,
4,4'-dihydroxy-3,3'-dicyclohexylbiphenyl, 3,3'-difluoro-4,4'-dihydroxybiphenyl, 2,2-bis (4-hydroxyphenyl) hexafluoropropane, 2,2-bis (3-phenyl-4-hydroxyphenyl) propane, 1,1-
Examples thereof include bis (3-phenyl-4-hydroxyphenyl) cyclohexane, bis (3-phenyl-4-hydroxyphenyl) sulfone, and 4,4'-dihydroxybenzophenone.

Particularly preferably, 2,2-bis (4-hydroxyphenyl) propane, 4,4'-dihydroxytetraphenylmethane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, bis (4 -Hydroxyphenyl) sulfone, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis (3-methyl-)
4-hydroxyphenyl) propane, 4,4'-dihydroxybiphenyl and 2,2-bis (3-phenyl-4)
-Hydroxyphenyl) propane is used. These dihydric phenols (I) may be used alone or in combination of two or more.

P + q representing the degree of polymerization of the polysiloxane unit in the dihydric phenol (II) represented by the general formula (II)
Is difficult to unconditionally specify because it relates to the strength, transparency and adhesion of the polycarbonate copolymer, but is generally less than 100, preferably less than 80. When it exceeds 100, the transparency of the polycarbonate copolymer decreases.

As the dihydric phenol (II), for example, the following compounds are preferably used.

[0013]

[Chemical 5] In the method of the present invention, the dihydric phenol (II) may be used alone or in combination of two or more.

The ratio of the dihydric phenol (I) and the dihydric phenol (II) used is not particularly limited, but usually, the molar ratio of the dihydric phenol (I) and the dihydric phenol (II), (II ) / [(I) + (II)], 0.0
The range of 0001 to 0.3, preferably 0.0001 to 0.2 is preferable. When the molar ratio of the dihydric phenol (II) is less than 0.00001, the resulting polycarbonate copolymer may have insufficient mechanical strength. On the other hand, when this molar ratio exceeds 0.3, the surface hardness of the obtained polycarbonate copolymer may be insufficient.

Further, comonomers other than the above dihydric phenols (I) and (II) can be used in combination within the range not hindering the method of the present invention.

In the method of the present invention, the main component is a compound having a terminal chloroformate group and a degree of polymerization of 2 to 4 by first reacting a dihydric phenol (I) with a carbonic acid ester forming compound. An oligomer of dihydric phenol (I) is formed.

In producing the dihydric phenol (I) oligomer, the entire amount of the dihydric phenol (I) used in the method of the present invention may be converted into the oligomer at one time, or a part thereof may be used as a post-added monomer. It may be added as a reaction raw material to the interfacial polycondensation reaction in the latter stage. The post-addition monomer is added in order to accelerate the subsequent polycondensation reaction, and it is not necessary to intentionally add it when it is not necessary.

The method of this oligomer formation reaction is not particularly limited, but it is usually preferable to carry out the reaction in a solvent in the presence of an acid binder.

The proportion of the carbonic acid ester forming compound used is
It may be appropriately adjusted in consideration of the stoichiometric ratio (equivalent amount) of the reaction. When a gaseous carbonic acid ester-forming compound such as phosgene is used, a method of blowing it into the reaction system can be suitably adopted.

Examples of the acid binder include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide,
An alkali metal carbonate such as sodium carbonate or potassium carbonate, an organic base such as pyridine, or a mixture thereof is used.

The ratio of the acid binder used may be appropriately determined in consideration of the stoichiometric ratio (equivalent amount) of the reaction, similarly to the above. Specifically, it is preferable to use 2 equivalents or slightly excess amount of the acid binder with respect to the number of moles of the dihydric phenol (I) used for forming the oligomer (usually 1 mole corresponds to 2 equivalents). .

As the above-mentioned solvent, a solvent inert to various reactions such as those used in the production of known polycarbonates may be used alone or as a mixed solvent. Representative examples include hydrocarbon solvents such as xylene, halogenated hydrocarbon solvents such as methylene chloride and chlorobenzene. Particularly, a halogenated hydrocarbon solvent such as methylene chloride is preferably used. The interfacial polycondensation reaction may be carried out using two kinds of solvents that are immiscible with each other.

The reaction pressure for oligomer formation is not particularly limited and may be normal pressure, elevated pressure or reduced pressure, but it is usually advantageous to carry out the reaction under ordinary pressure. Reaction temperature is -20 to 5
It is selected from the range of 0 ° C., and in many cases, heat is generated with the polymerization, so water cooling or ice cooling is desirable. The reaction time depends on other conditions and cannot be specified unconditionally, but it is usually 0.
It takes 2 to 10 hours.

In the present invention, an oligomer of dihydric phenol (I) having a terminal chloroformate group and having a degree of polymerization of 2 to 4 as a main component is thus obtained, and then the oligomer A polyvalent phenol (II) is subjected to interfacial polycondensation in a mixed solution of a solution of the oligomer and the dihydric phenol (II) in an organic solvent insoluble in water and an aqueous alkaline solution to obtain a polycarbonate copolymer. .

As the organic solvent used in this interfacial polycondensation reaction, the same ones as those used in the former oligomer formation reaction can be used, and particularly halogenated hydrocarbon solvents such as methylene chloride are preferably used. To be

Examples of the alkaline aqueous solution used in this interfacial polycondensation reaction include aqueous solutions of alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and alkali metal carbonates such as sodium carbonate and potassium carbonate. Of these, an aqueous solution of sodium hydroxide and potassium hydroxide is preferably used, but is not limited thereto.

The proportion of alkali used may be appropriately determined in consideration of the stoichiometric ratio (equivalent) of the reaction. Specifically, when the dihydric phenol (II) to be used or a part of the dihydric phenol (I) is added as a post-added monomer to this reaction step as described above, the post-added amount of the dihydric phenol ( It is preferable to use 2 equivalents or a slight excess of alkali with respect to the total number of moles of I) and the dihydric phenol (II) (usually 1 mole corresponds to 2 equivalents).

The polycondensation by the interfacial polycondensation reaction between the dihydric phenol (I) oligomer and the dihydric phenol (II) is carried out by the above organic solvent solution and the above alkaline aqueous solution in which the oligomer and the dihydric phenol (II) are uniformly dissolved. It is performed by vigorously stirring the mixed solution consisting of.

Further, in order to accelerate the polycondensation reaction, a catalyst such as a tertiary amine such as triethylamine or a quaternary ammonium salt, and in order to adjust the degree of polymerization,
It is desirable to add a monohydric phenol such as p-tert-butylphenol or phenylphenol as a molecular weight modifier to carry out the reaction. If desired, a small amount of an antioxidant such as sodium sulfite and hydrosulfide may be added. The reaction pressure may be any of reduced pressure, normal pressure, and increased pressure, but normally, it can be suitably carried out at normal pressure or the self-pressure of the reaction system. Reaction temperature is -20 to 50
The temperature is selected from the range of ° C, and in many cases, heat is generated with polymerization, so water cooling or ice cooling is desirable. The reaction time varies depending on other conditions such as the reaction temperature and therefore cannot be specified unconditionally, but is usually 0.5 to 10 hours.

In the method of the present invention, the above-mentioned reaction conditions,
The concentration of the obtained polycarbonate copolymer in which methylene chloride is used as a solvent is 0.5 g /
It is preferable to adjust the reduced viscosity [η _sp / c] of the dl solution at 20 ° C. to have a solution viscosity of 0.2 to 2.5 dl / g. If the reduced viscosity of the obtained polycarbonate copolymer is less than 0.2 dl / g, the mechanical strength may be insufficient. For example, when such a polycarbonate copolymer is used as a binder resin for the photosensitive layer of an electrophotographic photosensitive member, the surface hardness of the photosensitive layer is insufficient, so that the photosensitive member is worn and the printing life is shortened in practical use. . The polycarbonate copolymer obtained has a reduced viscosity of 2.5 dl.
If it exceeds / g, the solution viscosity may increase and the molding means may be restricted. For example, when such a polycarbonate copolymer is used as a binder resin for an electrophotographic photoreceptor, it becomes difficult to form a photosensitive layer by a solution coating method.

If desired, the obtained polycarbonate copolymer may be subjected to appropriate physical treatment (mixing, fractionation, etc.) and / or chemical treatment (polymer reaction, crosslinking treatment, partial decomposition treatment, etc.) to obtain a desired composition. It can also be obtained as a polycarbonate copolymer having a reduced viscosity [η _sp / c].

The obtained reaction product (crude product) can be recovered as a polycarbonate copolymer having a desired purity (purification degree) by subjecting to various post-treatments such as a known separation and purification method.

[0033]

EXAMPLES The present invention will now be described in detail based on examples, but the present invention is not limited thereto.

Example 1 54.7 g (0.2% of 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) was used as a raw material monomer.
24 mol) and an aqueous solution of sodium hydroxide having a concentration of 8% by weight 5
Dissolve in 50 ml, 250 m of this aqueous solution and methylene chloride
1 was introduced into a reactor equipped with a baffle, and phosgene gas was blown therein at a rate of 950 ml / min for 15 minutes while maintaining the temperature at around 10 ° C. and vigorous stirring. After allowing this reaction solution to stand, the organic layer was separated to obtain a methylene chloride solution of an oligomer of bisphenol A having a degree of polymerization of 2 to 4 and a molecular end having a chloroformate group.

30.6 g (0.018 mol) of the following dihydric phenol and 205 methylene chloride were added to this oligomer solution.
ml was introduced into a reactor equipped with a baffle, and the mixture was kept at about 10 ° C. and stirred to obtain a uniform solution. Further, 0.15 g of p-tert-butylphenol as a terminal stopper and 11.2 g (0.05% of bisphenol A) as a post-added monomer.
150 mol of sodium hydroxide aqueous solution having a concentration of 8% by weight
What was mixed with 10 ml of a 10 wt% triethylamine aqueous solution was added, and the mixture was kept at about 10 ° C. and vigorously stirred to carry out a polycondensation reaction.

[0036]

[Chemical 6]

After completion of the reaction, the organic layer was diluted with 1 liter of methylene chloride, washed with water, diluted hydrochloric acid and water in this order, and then poured into methanol to obtain 98 g of a polycarbonate copolymer.

The polycarbonate copolymer thus obtained has a concentration of 0.5 g / d in methylene chloride as a solvent.
The reduced viscosity [η _sp / c] of the solution of 1 is 20 ° C.
78 dl / g, GPC using THF as solvent
As a result of the analysis, a single peak showing a uniform molecular weight distribution is M
w: confirmed around 37,000, Mw / Mn is 1.9
It was 8. It was confirmed by ¹ H-NMR spectrum analysis that this polycarbonate copolymer was composed of the following repeating units.

[0039]

[Chemical 7]

Example 2 72 g (0.25 mol) of 4,4'-dihydroxytetraphenylmethane (bisphenol TP) was used as a raw material monomer, and 550 m of an aqueous potassium hydroxide solution having a concentration of 10% by weight.
The resulting solution was dissolved in 1, and 250 ml of this aqueous solution and methylene chloride were introduced into a reactor equipped with a baffle, and phosgene gas was blown therein at a rate of 950 ml / min for 15 minutes while maintaining vigorous stirring at about 10 ° C. After the reaction solution was allowed to stand, the organic layer was separated to obtain a methylene chloride solution of an oligomer of bisphenol TP having a polymerization degree of 2 to 4 and a terminal of a chloroformate group.

13.0 g (0.01 mol) of the following dihydric phenol and 185 m of methylene chloride were added to this oligomer solution.
1 was introduced into a reactor equipped with a baffle, and the mixture was kept at about 10 ° C. and stirred to obtain a uniform solution. Furthermore, p is used as a terminal stopper.
A mixture of 0.15 g of -tert-butylphenol and 150 ml of an aqueous potassium hydroxide solution was added with 5 ml of a 10 wt% triethylamine aqueous solution, and the mixture was kept at around 10 ° C. and vigorously stirred to carry out a polycondensation reaction.

[0042]

[Chemical 8]

After completion of the reaction, the organic layer was diluted with 1 liter of methylene chloride, washed with water, diluted hydrochloric acid and water in this order, and then poured into methanol to obtain 97 g of a polycarbonate copolymer.

The polycarbonate copolymer thus obtained has a concentration of 0.5 g / d in methylene chloride as a solvent.
The reduced viscosity [η _sp / c] of the solution of 1 is 20 ° C.
75 dl / g, GPC using THF as solvent
As a result of the analysis, a single peak showing a uniform molecular weight distribution is M
w: Confirmed around 36,000. It was confirmed by ¹ H-NMR spectrum analysis that this polycarbonate copolymer was composed of the following repeating units.

[0045]

[Chemical 9]

Comparative Example 1 European Patent Application Publication No. 0 500 087 (19)
92), 54.7 g (0.24 mol) of bisphenol A as a raw material monomer and 108 g (0.03 mol) of the following dihydric phenol were added to 550 ml of a sodium hydroxide aqueous solution having a concentration of 8% by weight and stirred vigorously. However, it did not dissolve, a uniform solution was not obtained, and an oily substance dispersion liquid was obtained.

[0047]

[Chemical 10]

This dispersion and p-te as a terminal stopper are used.
rt-Butylphenol 0.15 g, 10 wt% triethylamine aqueous solution 5 ml, and methylene chloride 250 ml
Was introduced into the reactor with a baffle, white crystals were deposited. Phosgene gas was blown into the reaction liquid at a rate of 340 ml / min for 30 minutes while vigorously stirring so that the crystals were finely crushed while keeping the reaction liquid at about 10 ° C. Furthermore, stirring was continued at room temperature for 2 hours to try to complete the polymerization. After that, add 1 liter of methylene chloride to the organic layer to dilute,
After washing with water, diluted hydrochloric acid, and water in this order, the mixture was poured into methanol to obtain a white polycarbonate copolymer.

The polycarbonate copolymer thus obtained has a concentration of 0.5 g / d in methylene chloride as a solvent.
The reduced viscosity [η _sp / c] of the solution of 1 is 20 ° C.
45 dl / g, GPC using THF as solvent
As a result of the analysis, a distribution line having two peaks showing a non-uniform molecular weight distribution was confirmed. It was confirmed by ¹ H-NMR spectrum analysis that this polycarbonate copolymer was composed of the following repeating units.

[0050]

[Chemical 11]

[0051]

According to the method of the present invention, not only excellent transparency and heat resistance but also a polycarbonate copolymer containing a high molecular weight and high strength siloxane unit can be easily and stably obtained. The polycarbonate copolymer obtained by the method of the present invention is extremely useful as a material for industrial materials in general and electronic / electrical equipment parts. Particularly, by utilizing its excellent mechanical strength such as abrasion resistance, electrophotographic photosensitivity is obtained. By using it as a binder resin for the photosensitive layer of the body, it becomes possible to obtain an electrophotographic photoreceptor having excellent printing durability and electrophotographic characteristics.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomohiro Nagao 1280 Kamizumi, Sodegaura-shi, Chiba Idemitsu Kosan Co., Ltd.

Claims (1)

[Claims] 1. The following general formula (I): [Wherein, R ¹ and R ² are each independently a halogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 12 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms. And a and b are each independently an integer of 0 to 4, Y is a single bond, -O-, -CO-, -S-, -SO.
—, —SO ₂ —, —CR ³ R ⁴ — (wherein R ³ and R ⁴ are each independently a hydrogen atom, a trifluoromethyl group, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 5 to 12 carbon atoms. An alkyl group or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms), a 1,1-cycloalkylidene group having 5 to 8 carbon atoms or an α, ω-alkylene group having 2 to 12 carbon atoms. ] The dihydric phenol (I) represented by the following general formula (II) (In the formula, R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms. Group, R
¹¹ and R ¹² are each independently a halogen atom or a carbon number of 1 to 6.
Is an alkyl group or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, c and d are each independently an integer of 0 to 4, and X is a substituted or unsubstituted alkylene group having 1 to 6 carbon atoms. , N is an integer of 1 to 6, p is a natural number, q is 0 or a natural number, and p + q is a natural number less than 100. ) Dihydric phenol (I
When a polycarbonate copolymer is produced by reacting I) with an ester-forming compound, the dihydric phenol (I) is reacted with the ester-forming compound in advance to have a terminal chloroformate group. Two
To the dihydric phenol (II) and a solution of the dihydric phenol (II) in a water-insoluble organic solvent. A method for producing a polycarbonate copolymer, which comprises performing interfacial polycondensation in a mixed solution with an alkaline aqueous solution.