JP2571586B2 - New polycarbonate copolymer and its production method. - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a novel polycarbonate copolymer and a method for producing the same, and more particularly, to a polycarbonate copolymer excellent in melt fluidity and a method for producing the same. About.

[Conventional technology]

Polycarbonate resins have excellent transparency, heat resistance, and mechanical strength, and are used in various fields such as the optical field, the electric field, the medical field, and the chemical field.

However, the commonly used 2,2-bis (4
-Hydroxyphenyl) propane polycarbonate has a drawback of poor melt fluidity during molding such as injection molding, and is particularly unsuitable for use in ultra-precision molded products. There was a point.

[Problems to be solved by the invention]

The present invention provides a novel polycarbonate-based copolymer having excellent basic properties such as transparency, heat resistance, and mechanical strength, and having significantly improved melt fluidity at the time of molding, and having extremely small stress generated at the time of molding. The purpose is to do.

[Means for solving the problem]

The present inventors have conducted intensive studies and found that a polycarbonate-based copolymer having a repeating unit having a specific structure and having a specific polymer terminal structure satisfies the above object. Based on the above, the present invention has been completed.

That is, the present invention provides the following general formula (I) and general formula (I
I) [However, in the above formula, X ¹ and X ² are a single bond, -O-, -S
_{-, - SO 2 -, -} CO-, (Where R ³ and R ⁴ represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms or a phenyl group, and R ³ and R ⁴
May be the same or different. ), CH _{2 u} (where u represents an integer of 2 to 10), or (Where r represents an integer of 4 to 8), and X ¹ and X ² may be the same or different, and R ¹ and R ² are a halogen atom, a carbon atom having 1 to 6 carbon atoms. Alkyl group, carbon number 4-8
Represents a cycloalkyl group or a phenyl group, R ¹ and R ²
May be the same or different, and n and m are
Represents an integer of 0 to 4; And a polymer terminal is represented by the following formula:
Following general formula ^{(III) -CO-R 5 (} III) [where, R ⁵ represents an alkyl group having 8 to 30 carbon atoms. ],
The following general formula (IV) Wherein R ⁶ represents an alkyl group having 8 to 30 carbon atoms;
Represents a single bond, -O- or -COO-. ], The following general formula (V) [However, X ¹ and R ⁵ each have the same meaning as described above.] ], The following general formula (VI) [However, X ¹ , Y and R ⁶ each have the same meaning as described above.] And the following general formula (VII) [However, R ⁷ and R ⁸ represent the same meanings as R ¹ and R ^2, and k and j represent the same meanings as n and m,
X ² and R ⁵ each have the same meaning as described above. And the following general formula (VIII) [However, R ⁷ , R ⁸ , R ⁶ , X ² , Y, k and j each have the same meaning as described above.] ] It is intended to provide a polycarbonate copolymer having any one of the above structures.

In the polycarbonate-based copolymer of the present invention, the main chain of the copolymer is one of the repeating units represented by the general formula (I).
And / or two or more kinds of repeating units represented by the general formula (II), and the molar percentage of the repeating units represented by the general formula (I) is preferably 50%. In addition, at least one terminal of the polymer, preferably both terminals are each represented by the general formula (II)
It is a terminal-modified polycarbonate copolymer having a structure represented by any of I) to (VIII).

When the molar percentage of the repeating unit represented by the general formula (I) is less than 50%, the photoelastic coefficient increases,
Alternatively, the melt fluidity during molding may not be sufficiently obtained.

The copolymer may be any of a random polymer, an alternating polymer, and a block polymer, and may be a mixture thereof.In general, a random polymer is preferably used in terms of ease of production and the like. Is done.

The polymer has at least one end, preferably both ends, each of which is constituted by at least one of the groups represented by the general formulas (III) to (VIII) as described above. In general, those represented by the general formula (V) or (VI) can be suitably used from the viewpoint of ease of production and the like.

Wherein used as the X ¹ and X ² Specific examples of each of R ³ and R ⁴ include, for example, a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group,
Pentyl group, phenyl group and the like.
Consists of R ³ and R ⁴ Particularly preferred of, for example, And the like.

Said Particularly preferred are, for example, And the like.

Particularly preferred examples of the X ¹ include, for example, And the like.

Particularly preferred examples of the X ² include, for example, And the like.

Specific examples of R ¹ and R ² include, for example, a halogen atom such as a fluorine atom and a chlorine atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a hexyl group, an isohexyl group, and a cyclopentyl group. , A cyclohexyl group, a phenyl group and the like, and among them, for example, a fluorine atom, a methyl group, a cyclohexyl group, a phenyl group and the like are preferable.

Each of n and m represents an integer of 0 to 4, and is usually preferably about 0 to 2, particularly preferably 0 or 1.

Specific examples of each of R ⁵ and R ^{6 in} the copolymer terminal group include, for example, a linear or branched octyl group,
Nonyl, decyl, dodecyl, pentadecyl, octadecyl and the like can be mentioned.

X ¹ , X ² , R ¹ and R ² in the copolymer terminal group may be of the same type or different types as those in the repeating unit, Usually, the same type is preferably used. Further, k and j in the general formulas (VII) and (VIII) may be the same as or different from n and m in the general formula (II). It is preferable to use n and m or m and n, respectively, from the viewpoint of ease of manufacturing and the like.

The polycarbonate copolymer of the present invention has a specific polymer main chain structure and a specific polymer terminal structure as described above, and the polycarbonate copolymer has a methylene chloride solvent of 0.5. It is desirable that the solution having a g / dl concentration has a reduced viscosity [η _SP / c] at 20 ° C. of 0.2 dl / g or more, preferably 0.25 to 0.8 dl / g.

If the reduced viscosity is less than 0.2 dl / g, sufficient strength cannot be obtained.

The polycarbonate copolymer of the present invention is usually preferably composed of a straight-chain polycarbonate. However, if desired, a partially branched structure-based one may be used as long as the object of the present invention is not hindered. It is also possible to use a small amount of an unmodified polymer molecule or a compound represented by the general formula (II)
A polymer having a terminal group other than I) to (VIII) may be contained. Further, as long as the object of the present invention is not hindered, the polymer is represented by the general formula (I) or (II). May contain other repeating units. Depending on the purpose of use, various commonly used additives may be added, or the composition may be used as a composition with another polymer such as polycarbonate.

The polycarbonate copolymer of the present invention generally has the following general formula (IX) And a dihydric phenol represented by the formula (X) In the represented dihydric phenol, when reacting a carbonic ester-forming compound to produce a polycarbonate polymer, a molecular weight ^{modifier, R 5 -COOH, R 5 -COX} 3 or Can be produced by using any of the above.

[However, in the above formula, X ¹ , X ² , R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ ,
n, m and Y each have the same meaning as described above, and X ³
Represents a halogen atom. The above-mentioned molecular weight regulator acts as a modifier for the terminal of the polymer, and other molecular weight regulators, for example, monofunctional phenols, naphthalenes, etc., within a range not interfering with the object of the present invention. It is also possible to use a known monofunctional organic compound or the like in combination.

Specific examples of the compound represented by the general formula (IX) include, for example, 3,3'-diphenyl-4,4'-dihydroxybiphenyl, bis (3-phenyl-4-hydroxyphenyl) methane, 1-phenyl- 1,1-bis (3-phenyl-4-hydroxyphenyl) methane, 1,1-bis (3
-Phenyl-4-hydroxyphenyl) ethane, 1,2-
Bis (3-phenyl-4-hydroxyphenyl) ethane, 1-phenyl-1,1-bis (3-phenyl-4-hydroxyphenyl) ethane, 2,2-bis (3-phenyl-4-hydroxyphenyl) propane , 2,2-bis (3
-Phenyl-4-hydroxyphenyl) butane, 1,4-
Bis (3-phenyl-4-hydroxyphenyl) butane, 1,1-bis (3-phenyl-4-hydroxyphenyl) -1-phenylbutane, 2,2-bis (3-phenyl-4-hydroxyphenyl) octane , 1,8-bis (3
-Phenyl-4-hydroxyphenyl) octane, bis (3-phenyl-4-hydroxyphenyl) ether,
Bis (3-phenyl-4-hydroxyphenyl) sulfide, bis (3-phenyl-4-hydroxyphenyl)
Ketone, bis (3-phenyl-4-hydroxyphenyl) sulfone, 1,1-bis (3-phenyl-4-hydroxyphenyl) cyclopentane, 1,1-bis (3-phenyl-4-hydroxyphenyl) cyclohexane, etc. And particularly, among these, 2,2-bis (3-
Phenyl-4-hydroxyphenyl) propane, 1-phenyl-1,1-bis (3-phenyl-4-hydroxyphenyl) ethane and the like are preferred.

Note that these compounds may be used alone.
Two or more kinds may be used in combination.

Specific examples of the compound represented by the general formula (X) include bis (4-hydroxyphenyl) methane,
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) propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-
(Hydroxyphenyl) octane, 4,4-bis (4-hydroxyphenyl) heptane, 1,1-bis (3,5-dibromo-4-hydroxyphenyl) methane, 1,1-bis- (3
-Chloro-4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) -1,1-diphenylmethane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, bis (4-hydroxy Phenyl) ether, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) ketone, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis (3-fluoro-4-hydroxyphenyl) propane, 2,2-bis (3-chloro-4-hydroxyphenyl) propane,
2-bis (3,5-difluoro-4-hydroxyphenyl)
Propane, 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane, 2,2-bis (3-methyl-4-hydroxyphenyl) propane, 2,2-bis (3,5-dimethyl- 4-hydroxyphenyl) propane, 2,2-bis (3-cyclohexyl-4-hydroxyphenyl) propane, 2- (3-methyl-4-hydroxyphenyl)-
2- (4-hydroxyphenyl) propane, 1,1-bis (3-methyl-4-hydroxyphenyl) -1-phenylethane, 1,1-bis (3-fluoro-4-hydroxyphenyl) -1-phenyl Ethane, bis (3-methyl-
4-hydroxyphenyl) ether, bis (3-methyl-4-hydroxyphenyl) sulfide, bis (3-methyl-4-hydroxyphenyl) sulfone, bis (3-
Methyl-4-hydroxyphenyl) ketone, bis (3-
Methyl-4-hydroxyphenyl) methane, 1,1-bis (3-methyl-4-hydroxyphenyl) cyclohexane, 1,1-bis (3-cyclohexyl-4-hydroxyphenyl) cyclohexane, 4,4'-dihydroxybiphenyl , 3,3'-difluoro-4,4'-dihydroxybiphenyl and the like. Among them, 2,2-bis (4-hydroxyphenyl) propane and 1,1-bis (4
-Hydroxyphenyl) -1,1-diphenylmethane, bis (4-hydroxyphenyl) sulfone, 1,1-bis (3-cyclohexyl-4-hydroxyphenyl) cyclohexane and the like are preferred. In addition, these compounds are 1
The species may be used alone, or two or more species may be used in combination.

Examples of the compounds represented by the above general formulas R ⁵ —COOH and R ⁶ —COX ³ include those in which X ³ is a halogen atom, and those having a chlorine atom are preferred. For example, nonanoyl chloride, nonanoyl bromide, decanoyl chloride, decanoyl bromide, undecanoyl chloride, dodecanoyl chloride, pentadecanoyl chloride, hexadecanoyl chloride, octadecanoyl chloride, icosanoyl chloride, nonanoic acid, Decanoic acid, undecanoic acid, dodecanoic acid, pentadecanoic acid, hexadecanoic acid, octadecanoic acid and the like can be mentioned.

These compounds may be used alone.
Two or more kinds may be used in combination.

Examples of the compound represented by the general formula (XI) include p-octylphenol, m-octylphenol, o-octylphenol, p-nonylphenol,
m-nonylphenol, p-decylphenol, p-
(2-methylnonyl) phenol, p-undecylphenol, p-dodecylphenol, p- (2-methyldodecyl) phenol, p-pentadecylphenol, p
-Hexadecylphenol, p-octadecylphenol, m-octadecylphenol, p-octyloxyphenol, m-octyloxyphenol, p-nonyloxyphenol, p-decyloxyphenol, p
-Dodecyloxyphenol, p-hexadecyloxyphenol, p-octadecyloxyphenol, p-
Octyloxycarbonylphenol, m-octyloxycarbonylphenol, p-nonyloxycarbonylphenol, p-decyloxycarbonylphenol (decyl p-hydroxybenzoate), p-dodecyloxycarbonylphenol (dodecyl p-hydroxybenzoate), p -Hexadecyloxycarbonylphenol, p-octadecyloxycarbonylphenol and the like.

Among them, the p-form is preferable, and particularly, p-nonylphenol, p-decyloxyphenol, p-dodecyloxycarbonylphenol and the like can be suitably used.

In addition, these compounds may be used individually by 1 type, and may use 2 or more types together.

As the carbonate-forming compound, those used in the production of conventional polycarbonates using bisphenol A or the like as a monomer, for example, carbonyl halides, carbonates, haloformates and the like can be used.

Specific examples of the carbonyl halide include, for example, carbonyl dibromide, carbonyl dichloride (phosgene)
Alternatively, a mixture thereof can be mentioned.

Examples of the carbonate include diphenyl carbonate, di (chlorophenyl) carbonate, ditolyl carbonate, dinaphthyl carbonate, and the like, and mixtures thereof.

Examples of the haloformates include a chloroformate of the compound represented by the general formula (IX),
Or a mixture thereof can be used.

The reaction (polymerization reaction) between the monomer and the carbonate-forming compound and the polymer terminal group modification reaction (termination reaction) with the molecular weight regulator can be carried out according to a known polymerization method or terminal group modification reaction method. For example, the following reaction method can be suitably employed.

That is, phosgene is introduced into the compound represented by the general formula (IX) or a mixture of the compound represented by the general formula (X) and the compound represented by the general formula (X) at a predetermined mole percentage to form a terminal-unmodified oligomer or polymer, Next, a method in which an appropriate amount of the molecular weight regulator is added and the termination reaction is performed while continuing the polymerization reaction can be particularly preferably employed. In addition, after obtaining a terminal unmodified polymer having a predetermined molecular weight or a polymer modified with another terminal group, the above-mentioned molecular weight regulator is reacted with the terminal hydroxyl group of the polymer to introduce a desired terminal group, A method of introducing a terminal group of the above by an exchange reaction or the like is also applicable.

In carrying out the above polymerization reaction and polymer terminal group modification reaction, an acid acceptor and a catalyst can be appropriately used.

Examples of the acid acceptor include organic acid acceptors such as tertiary amines such as triethylamine, N, N-dimethylaniline, tripropylamine, tributylamine and pyridine; and alkali metal or alkaline earth metal hydroxides. , Carbonates, bicarbonates, phosphates and other inorganic acid acceptors can be used. Among them, usually, strong alkali compounds such as sodium hydroxide and potassium hydroxide can be suitably used. In addition, these alkali hydroxides can also be used as salts with the monomers represented by the general formulas (IX) and (X).

The polymerization reaction and the terminal group modification reaction can be carried out in the presence of a solvent, if desired.

As the solvent, those used in the production of known polycarbonates having bisphenol A or the like as a monomer,
That is, an aqueous solvent, a non-aqueous polar solvent and the like can be used.

As the catalyst, known catalysts can be used. Specifically, for example, tertiary amines such as triethylamine, tripropylamine, N, N-dimethylaniline, tetraethylammonium chloride, tetraethylammonium bromide, tetramethylammonium chloride And quaternary ammonium compounds such as tetramethylammonium hydroxide, and quaternary phosphonium compounds such as methyltriphenylphosphonium bromide. Of these, tertiary amines such as triethylamine can be preferably used.

In conducting the above polymerization reaction, a polycarbonate having a partially branched structure may be added, if desired, by adding an appropriate amount of a polyfunctional compound such as a known trifunctional compound as long as the object of the present invention is not hindered. System copolymer,
It is also possible to add other known monomers to introduce other repeating units into the main chain of the polymer.

The polycarbonate thus obtained can be subjected to a post-treatment such as a separation operation by a known separation method or the like, a purification operation such as a known washing method, or the like to obtain a desired purity.

The polycarbonate-based copolymer obtained as described above, as it is, or as desired, is blended with a polymer such as an additive or another polycarbonate depending on the purpose of use to form a composition and used for various purposes. be able to.

The material for an optical device of the present invention comprising a polycarbonate-based copolymer that can be obtained in this manner is remarkably excellent in melt fluidity during molding such as injection molding, is easy to mold, and has polycarbonate. Transparency, heat resistance, as well as being excellent in basic properties such as mechanical strength, is a material for excellent optical equipment that can obtain a molded article with significantly reduced optical anisotropy such as birefringence, for example, It can be suitably used as a molded product for various optical devices such as lenses, optical disks, and optical fibers, particularly a molded product for ultra-precision optical devices.

In addition, electric iron water tank, microwave oven supplies,
Liquid crystal display substrates, printed circuit boards, high-frequency circuit boards, electrical fields such as transparent conductive sheets and films, medical equipment such as syringes, pipettes, and animal gauges, chemical fields, camera bodies, various instrument housings, films, sheets, and helmets. And so on in various fields.

〔Example〕

Hereinafter, the present invention will be described in detail based on examples,
The present invention is not limited to this.

Example 1 A flask having a content of 1 was charged with 2,2-bis (3-phenyl-
4-hydroxyphenyl) propane 76 g (0.20 mol) and 2,
11.4 g of 2-bis (4-hydroxyphenyl) propane (0.
05 mol) in 600 ml of a 3N aqueous potassium hydroxide solution and 250 ml of methylene chloride were added, and phosgene was blown in at a rate of 340 ml / min for 30 minutes while maintaining the liquid temperature at around 10 ° C. by external cooling. Then, p-nonylphenol
1 g and 2 ml of a 0.5 M aqueous triethylamine solution were added, and the mixture was stirred for 1 hour to polymerize.

After completion of the polymerization, the organic layer was diluted by adding 500 ml of methylene chloride, washed with water, dilute hydrochloric acid and water in that order, and then poured into methanol to obtain a polycarbonate.

The concentration of this polymer is 0.5 g / dl using methylene chloride as a solvent.
The reduced viscosity [η _sp / c] of the solution at 20 ° C. was 0.58 dl / g.

From the ¹ H-NMR spectrum analysis of this copolymer,
Absorption of the phenyl group (6.7 to 7.6 ppm) and the methylene chain (1.3 ppm) of the nonyl group at the molecular terminal was confirmed, and it was confirmed to be composed of the following repeating unit and terminal structure.

Table 1 shows the physical properties of the obtained polymer.

Example 2 In the same manner as in Example 1 except that 25.2 g of 1,1-diphenyl-1,1-bis (4-hydroxyphenyl) methane was used instead of 2,2-bis (4-hydroxyphenyl) propane. To obtain a copolymer. Repeating units and end structure constituting the copolymer ⁽¹ H-NMR analysis) was as follows.

Example 3 In Example 1, instead of 2,2-bis (3-phenyl-4-hydroxyphenyl) propane, 1-phenyl-
1,1-bis (3-phenyl-4-hydroxyphenyl)
Using 77 g (0.174 mol) of ethane, 16.5 g (0.076 mol) of bis (4-hydroxyphenyl) sulfone was used instead of 2,2-bis (4-hydroxyphenyl) propane, and p-nonylphenol was used instead of p-nonylphenol. A copolymer was obtained in the same manner except that 1.39 g of n-dodecyl hydroxybenzoate was used. Repeating units and end structure constituting the copolymer ⁽¹ H-NMR analysis) was as follows. Table 1 shows the physical properties of the obtained polymer.

Example 4 In Example 1, 21.6 g of 1,1-bis (3-cyclohexyl-4-hydroxyphenyl) cyclohexane was used instead of 2,2-bis (4-hydroxyphenyl) propane.
(0.05 mol), and a copolymer was obtained in the same manner except that 1.26 g of p-dodecyloxyphenol was used instead of p-nonylphenol. Repeating units and end structure constituting the copolymer ⁽¹ H-NMR analysis) was as follows. Table 1 shows the physical properties of the obtained polymer.

Comparative Example 1 In Example 1, instead of 2,2-bis (3-phenyl-4-hydroxyphenyl) propane, 2,2-bis (4
A polymer was obtained in the same manner except that p-tert-butylphenol was used in place of -hydroxyphenyl) propane and p-nonylphenol.

 Table 1 shows the physical properties of the obtained polymer.

[Effects of the Invention] The polycarbonate-based copolymer of the present invention is excellent in basic properties such as transparency, heat resistance, and mechanical strength of general polycarbonate resins, such as mechanical strength. It has remarkably excellent melt fluidity at the time of molding such as molding, is easy to mold, and has an extremely advantageous effect in practical use, in particular, capable of easily obtaining an ultra-precision molded product.

Claims (2)

(57) [Claims] 1. The following general formula (I) and general formula (II) [However, in the above formula, X ¹ and X ² are a single bond, -O-,-
_{S -, - SO 2 -,} - CO-, (Wherein, R ³ and R ⁴ are a hydrogen atom, a halogen atom, an alkyl group or a phenyl group having 1 to 6 carbon atoms, and R ³
R ⁴ may be the same or different. ), CH _{2 u} (where u represents an integer of 2 to 10), or (Where r represents an integer of 4 to 8), and X ¹ and X ² may be the same or different, and R ¹ and R ² are a halogen atom, a carbon atom having 1 to 6 carbon atoms. Alkyl group, carbon number 4-8
Represents a cycloalkyl group or a phenyl group, R ¹ and R ²
May be the same or different, and n and m are
Represents an integer of 0 to 4; And a polymer terminal is represented by the following formula:
Following general formula ^{(III) -CO-R 5 (} III) [where, R ⁵ represents an alkyl group having 8 to 30 carbon atoms. ],
The following general formula (IV) Wherein R ⁶ represents an alkyl group having 8 to 30 carbon atoms;
Represents a single bond, -O- or -COO-. ], The following general formula (V) [However, X ¹ and R ⁵ each have the same meaning as described above.] ], The following general formula (VI) [However, X ¹ , Y and R ⁶ each have the same meaning as described above.] And the following general formula (VII) [However, R ⁷ and R ⁸ represent the same meanings as R ¹ and R ^2, and k and j represent the same meanings as n and m,
X ² and R ⁵ each have the same meaning as described above. And the following general formula (VIII) [However, R ⁷ , R ⁸ , R ⁶ , X ² , Y, k and j each have the same meaning as described above.] ] The polycarbonate-based copolymer which has any structure of these. 2. The formula (IX) And a dihydric phenol represented by the formula (X) Wherein, in the above formula, X ¹ and X ² are a single bond, -O-,-
_{S -, - SO 2 -,} - CO-, (Wherein, R ³ and R ⁴ are a hydrogen atom, a halogen atom, an alkyl group or a phenyl group having 1 to 6 carbon atoms, and R ³
R ⁴ may be the same or different. ), CH _{2 u} (where u represents an integer of 2 to 10), or (Where r represents an integer of 4 to 8), and X ¹ and X ² may be the same or different, and R ¹ and R ² are a halogen atom, a carbon atom having 1 to 6 carbon atoms. Alkyl group, carbon number 4-8
Represents a cycloalkyl group or a phenyl group, R ¹ and R ²
May be the same or different, and n and m are
Represents an integer of 0 to 4; A], when reacted with carbonic acid ester-forming compound to produce a polycarbonate polymer, a molecular weight ^{modifier, R 5 -COOH, R 5 -COX} 3 or [However, R ⁵ and R ₆ represents an alkyl group having 8 to 30 carbon atoms, X ³ represents a halogen atom, Y represents a single bond, represents -O- or -COO-. Wherein each of the following general formulas (I) and (II) is used. (Provided that X ¹ , X ² , R ¹ ,
R ² , n and m each have the same meaning as described above. ], And polymer end, the following general formula ^{(III) -CO-R 5 (} III), the general formula (IV) And the following general formula (V) And the following general formula (VI) And the following general formula (VII) And the following general formula (VIII) Wherein X ¹ , X ² , R ⁵ , R ⁶ and Y each have the same meaning as described above, R ⁷ and R ⁸ each have the same meaning as R ¹ and R ^2, and k and j Represents the same meaning as n and m described above. ] A method for producing a polycarbonate copolymer having any of the above structures.