JP2000302860A - Novel polycarbonate resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polycarbonate resin having a low photoelastic coefficient and well-balanced refractive index and Abbe's number, by making the resin composed of pentacyclopentadecanedimethanol alone or constitutional units derived from pentacyclopentadecanedimethanol and a bisphenol. SOLUTION: Compound(s) represented by formula V and/or formula VI and a carbonic acid diester or compounds represented by formula V and/or formula VI and formula VII and a carbonic acid diester are melt-polymerized in the presence of a basic compound catalyst to obtain a polycarbonate resin composed of constitutional units represented by formula I and/or formula II or constitutional units represented by formula I and/or formula II and formula III. In the formulae, R1 and R2 are each H, a halogen, 1-20C alkyl group, 1-20C alkoxyl group, 6-20C cycloalkyl group, 6-20C aryl group, 6-20C cycloalkoxyl group or 6-20C aryloxy group; (p) and (q) are each 0-4; X is formula IV or the like; and R3 and R4 are each H, a 1-12C alkyl group or 6-20C aryl group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to transparency, heat resistance,
The present invention belongs to a polycarbonate resin having a low balance between photoelastic coefficient, refractive index and Abbe number, and a method for producing the same. This polycarbonate resin can be suitably used as a material for plastic optical products such as optical disk substrates, various lenses, prisms, and optical fibers.

[0002]

2. Description of the Related Art A polycarbonate resin derived from bisphenol A obtained by reacting 2,2-bis (4-hydroxyphenyl) propane (commonly called bisphenol A) with phosgene or a carbonate ester has excellent heat resistance and transparency. Moreover, since it has excellent mechanical properties such as impact resistance, it is widely used as an optical material in optical disc substrates, various lenses, prisms, optical fibers, and the like as well as structural materials.

[0003] However, the polycarbonate resin from bisphenol A is a low-flow material and has a high photoelastic coefficient, and thus has a problem that birefringence due to molecular orientation and residual stress during molding is large. I have. for that reason,
When molding an optical material composed of a polycarbonate resin from bisphenol A, a method is used in which a resin having a relatively low molecular weight is used in order to improve fluidity, and birefringence of the product is reduced by molding at a high temperature. Have been. However, in the case of polycarbonate resin from bisphenol A, there is a limit to the reduction of birefringence even when the above-mentioned means are used. Therefore, there is a strong demand for the development of a material having a lower photoelastic coefficient and a higher fluidity.

As a method for reducing the photoelastic coefficient of a polycarbonate resin, for example, Japanese Patent Application Laid-Open No. 64-66234 discloses a method.
As disclosed in Japanese Patent Application Laid-Open Publication No. H10-260, a method is known in which bisphenol A is copolymerized with tricyclo (5.2.1.0 ^2,6 ) decane dimethanol. Is not sufficiently effective in reducing the amount of

Further, CR-39 (diethylene glycol bisallyl carbonate) is widely used as a lens material, especially as a plastic eyeglass lens material, but has a low refractive index of 1.50 and is produced from a thermosetting resin. There are problems such as poor performance, and a solution to these problems is desired.

[0006]

SUMMARY OF THE INVENTION The present invention aims to solve the problems associated with the prior art as described above, and has a lower photoelastic coefficient than a polycarbonate resin derived from bisphenol A, Another object of the present invention is to provide a polycarbonate resin excellent in the balance between the refractive index and the Abbe number and a method for producing the same.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies on a method for overcoming the above-mentioned problems, and as a result, as a structural unit, the structural formula (1) and / or the structural formula (2)
Polycarbonate resin consisting of structural units represented by
The inventors have found that the above-mentioned problems can be solved, and have reached the present invention.

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[0008] The present inventors have further proposed that the polycarbonate resin comprising the structural unit represented by the structural formula (1) and / or the structural formula (2) and the structural unit represented by the following structural formula (3) is The inventors have found that the problem can be solved, and have reached the present invention.

Embedded image (Wherein R ₁ and R ₂ are each independently a hydrogen atom,
A halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxyl group having 1 to 20 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a cycloalkoxyl group having 6 to 20 carbon atoms, or Represents an aryloxy group having 6 to 20 carbon atoms. P and q represent the number of substituents, and are integers from 0 to 4. X is R ₃ and R ₄ are each independently a hydrogen atom,
An alkyl group having 1 to 12 carbon atoms and an aryl group having 6 to 20 carbon atoms, and R ₃ and R ₄ may be bonded to form a ring. )

[0009]

DETAILED DESCRIPTION OF THE INVENTION The polycarbonate resin according to the present invention comprises a structural unit derived from an aliphatic dihydroxy compound represented by the general formula (4) and / or (5) and a structural unit derived from a carbonic acid diester. Consists of

[0010]

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The aliphatic dihydroxy compound represented by the general formulas (4) and / or (5) is pentacyclopentadecane dimethanol, and (4) and / or (5) each represent a pure substance even if it is a pure substance. May be a mixture in which the isomers are mixed at an arbitrary ratio.

Further, in the polycarbonate resin according to the present invention, a structural unit derived from the aliphatic dihydroxy compound represented by the above general formula (4) and / or (5) and a structural unit derived from carbonic acid diester In addition to the above, it is preferable from the viewpoint of physical properties balance to introduce a structural unit derived from an aromatic dihydroxy compound represented by the following general formula (6).

[0013]

Embedded image (Wherein R ₁ and R ₂ are each independently a hydrogen atom,
A halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxyl group having 1 to 20 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a cycloalkoxyl group having 6 to 20 carbon atoms, or Represents an aryloxy group having 6 to 20 carbon atoms. P and q represent the number of substituents, and are integers from 0 to 4. X is R ₃ and R ₄ are each independently a hydrogen atom,
An alkyl group having 1 to 12 carbon atoms and an aryl group having 6 to 20 carbon atoms, and R ₃ and R ₄ may be bonded to form a ring. )

The polycarbonate resin according to the present invention is derived from an aromatic dihydroxy compound represented by the general formula (6) and an aliphatic dihydroxy compound represented by the general formula (4) and / or (5). The molar ratio of the structural units (3) / [(1) + (2)] is 0/10
0 to 70/30 or less, more preferably 5/30
/ 95 to 60/40. That is, the molar ratio of the structural units respectively derived from the aromatic dihydroxy compound (6) in the polycarbonate resin (3) / [(1) +
If (2)] is higher than 70/30, the photoelastic coefficient increases, which is not preferable. In addition, the balance between the refractive index and the Abbe number deteriorates, which is not preferable.

In the polycarbonate resin according to the present invention, the impact resistance can be improved by including the structural unit (3) derived from the aromatic dihydroxy compound represented by the general formula (6). is there. That is, the structural units (1) and / or (2) derived from the aliphatic dihydroxy compound represented by the general formula (4) and / or (5), and the aromatic represented by the general formula (6) The molar ratio (3) / [(1) + (2)] is based on the structural unit (3) derived from the dihydroxy compound.
Is preferably 30/70 to 70/30. 3
If the value is smaller than 0/70, the effect of improving the impact resistance is reduced, which is not preferable. If it is larger than 70/30, the photoelastic coefficient increases, and the balance between the refractive index and the Abbe number deteriorates.

As the aromatic dihydroxy compound represented by the general formula (6), specifically, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2 -Bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl)
Octane, bis (4-hydroxyphenyl) phenylmethane, 1,1-bis (4-hydroxyphenyl) -1-
Phenylethane, bis (4-hydroxyphenyl) diphenylmethane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 1,1-bis (4-hydroxy-3-tert-butylphenyl) propane, 2, 2
-Bis (3,5-dimethyl-4-hydroxyphenyl)
Propane, 2,2-bis (4-hydroxy-3-phenylphenyl) propane, 2,2-bis (3-cyclohexyl-4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) )propane,
2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2- Bis (4-hydroxy-3-methoxyphenyl) propane, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene,
4,4′-dihydroxydiphenyl ether, 4,4 ′
-Dihydroxy-3,3'-dimethylphenyl ether, 4,4'-dihydroxyphenyl sulfide, 4,
4'-dihydroxy-3,3'-dimethyldiphenylsulfide, 4,4'-dihydroxydiphenylsulfoxide, 4,4'-dihydroxy-3,3'-dimethyldiphenylsulfoxide, 4,4'-dihydroxydiphenylsulfone, 4, For example, 4'-dihydroxy-3,3'-dimethyldiphenylsulfone is used.

In the present invention, the aromatic dihydroxy compound represented by the general formula (6) is preferably 2,2-
Bis (4-hydroxyphenyl) propane (commonly known as bisphenol A) is preferably used. Bisphenol A
Is very useful because it is mass-produced at low cost as a polycarbonate resin raw material, and when bisphenol A is used, the impact resistance can be increased without impairing the heat resistance.

In the present invention, in addition to the dihydroxy compounds represented by the above general formulas (4), (5) and (6), other types of dihydroxy compounds are copolymerized as long as various physical properties are not impaired. No problem. Specifically, tricyclo (5.2.1.0 ^{2, 6)} decane dimethanol, 1,4-cyclohexane dimethanol, 2,6
Decalin dimethanol, norbornane dimethanol, spiro glycol, hydroquinone, resorcinol, 4,4 '
-Dihydroxybiphenyl and the like.

The polycarbonate resin according to the present invention has at least the general formula (4) and / or (5)
And a structural unit derived from an aromatic dihydroxy compound represented by the general formula (6) in a predetermined ratio, and Or an alternating copolymer structure, so that it has a low photoelastic coefficient, excellent balance between refractive index and Abbe number.

As the polycarbonate resin in the present invention, a resin having a photoelastic coefficient of 60 × 10 ⁻¹² m ² / N or less is suitable, and more preferably 50 × 10 ⁻¹² m ² / N.
/ N. If the photoelastic coefficient exceeds 60 × 10 ⁻¹² m ² / N, the birefringence increases, and for example, when used as an optical disk substrate, adverse effects such as an increase in signal reading error occur, which is not preferable.

The polycarbonate resin in the present invention preferably has a refractive index of 1.53 or more and an Abbe number of 35 or more. When the refractive index is less than 1.53, when the plastic lens is used, the lens becomes thick, which is not preferable. On the other hand, if the Abbe number is less than 35, adverse effects such as easy fatigue of the eyes when used as a plastic spectacle lens are likely to occur, which is not preferable.

Examples of the carbonic acid diester used in the present invention include diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, di-m-cresyl carbonate, dinaphthyl carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate and the like. Are listed. Among these, diphenyl carbonate is particularly preferred. Carbonic acid diester is used in an amount of 0.9 to 1 mol of the total of the aromatic dihydroxy compound and the aliphatic dihydroxy compound.
It is preferably used in a ratio of 7 to 1.10 mol,
The ratio is more preferably 0.99 to 1.04 mol.

The polycarbonate resin according to the present invention has a weight average molecular weight in terms of polystyrene of 20,000 to 20.
It is preferably 0.000, more preferably 4
It is between 000 and 130,000. If the weight average molecular weight in terms of polystyrene is less than 20,000, the strength of the molded article becomes insufficient, and if it exceeds 200,000, the fluidity during molding deteriorates, which is not preferable.

In the method for producing a polycarbonate according to the present invention, a basic compound is used as a catalyst. Examples of such a basic compound include an alkali metal compound, an alkaline earth metal compound, a nitrogen-containing compound and a phosphorus-containing compound.

Examples of such basic compounds include organic acid salts such as alkali metal and alkaline earth metal compounds, inorganic salts, oxides, hydroxides, hydrides or alkoxides, quaternary ammonium hydroxides and salts thereof. , Amines and the like are preferably used, and these compounds can be used alone or in combination.

As such an alkali metal compound,
Specifically, 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 borohydride, sodium benzoate, potassium benzoate, cesium benzoate, lithium benzoate, disodium hydrogen phosphate Dipotassium hydrogen phosphate, dilithium hydrogen phosphate, disodium phenylphosphate, sodium tetraphenylborate, disodium salt of bisphenol A, 2 potassium salt, 2 cesium salt, 2 lithium salt, sodium salt of phenol, potassium Salts, cesium salts, lithium salts and the like are used.

Further, as the alkaline earth metal compound,
Specifically, magnesium hydroxide, calcium hydroxide,
Strontium hydroxide, barium hydroxide, magnesium bicarbonate, calcium bicarbonate, strontium bicarbonate, barium bicarbonate, magnesium carbonate, calcium carbonate, strontium carbonate, barium carbonate, magnesium acetate, calcium acetate, strontium acetate, barium acetate, stearic acid Magnesium, calcium stearate, strontium stearate, barium stearate, calcium benzoate, magnesium phenyl phosphate, phenol magnesium salt, calcium salt, strontium salt, barium salt and the like are used.

Examples of the nitrogen-containing compound and the phosphorus-containing compound include, specifically, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylbenzylammonium hydroxide and the like. Quaternary ammonium hydroxides having alkyl, aryl, araryl groups and the like, tertiary amines such as triethylamine, dimethylbenzylamine and triphenylamine, secondary amines such as diethylamine and dibutylamine, and 1 such as propylamine and butylamine Secondary amines, imidazoles such as 2-methylimidazole and 2-phenylimidazole, or ammonia, tetramethylammonium borohydride,
Basic salts such as tetrabutylammonium borohydride, tetrabutylammonium tetraphenylborate, tetraphenylammonium tetraphenylborate, tetraphenylphosphonium tetraphenylborate and the like are used.

These catalysts are used at a ratio of 10 ^-9 to 10 ^-3 mol, preferably 10 ^-7 to 10 ^-3 mol, per 1 mol of the total of the aliphatic dihydroxy compound and the aromatic dihydroxy compound.
It is used in a proportion of 10 ^-4 mol.

The transesterification according to the present invention can be carried out by a known melt polycondensation method. That is,
Melt polycondensation is carried out using the above-mentioned raw materials and a catalyst while removing by-products by a transesterification reaction under normal pressure or reduced pressure while heating. The reaction is generally carried out in two or more stages.

Specifically, the first-stage reaction is carried out at 120 to 2
0.1 ° C at a temperature of 60 ° C, preferably 180-240 ° C.
The reaction is performed for 5 hours, preferably 0.5 to 3 hours. Next, the reaction temperature is increased while increasing the degree of vacuum of the reaction system, and the reaction of the aromatic dihydroxy compound, the aliphatic dihydroxy compound and the carbonic acid diester is carried out. Finally, the reaction is carried out at a temperature of 200 to 300 ° C. under a reduced pressure of 1 mmHg or less. Perform a condensation reaction.
Such a reaction may be carried out continuously or batchwise. The reactor used for performing the above reaction was a vertical type equipped with an anchor type stirring blade, a max blend stirring blade, a helical ribbon type stirring blade, etc., but also equipped with paddle blades, lattice wings, glasses wings and the like. It may be a horizontal type or an extruder type equipped with a screw,
It is preferable to use a reaction apparatus in which these are appropriately combined.

In the polycarbonate according to the present invention, the catalyst is removed or deactivated in order to maintain heat stability and hydrolysis stability after the completion of the polymerization reaction. In general, a method of deactivating a transesterification catalyst such as an alkali metal or an alkaline earth metal by adding a known acidic substance is suitably performed. Specific examples of these substances include aromatic sulfonic acids such as p-toluenesulfonic acid, aromatic sulfonic esters such as butyl p-toluenesulfonic acid and hexyl p-toluenesulfonic acid, and tetradecylbenzenesulfonic acid. Aromatic phosphonium salts such as butylphosphonium salts, organic halides such as stearic acid chloride, benzoyl chloride, p-toluenesulfonic acid chloride, alkyl sulfates such as dimethyl sulfate, and organic halides such as benzyl chloride are preferably used. Can be

After deactivation of the catalyst, a step of devolatilizing and removing low-boiling compounds in the polymer at a pressure of 0.1 to 1 mmHg and at a temperature of 200 to 300 ° C. may be provided. A horizontal device equipped with a stirring blade having an excellent surface renewing ability, such as a wing or an eyeglass wing, or a thin film evaporator is preferably used.

Further, in the present invention, the above-mentioned heat stabilizer,
In addition to hydrolysis stabilizers, antioxidants, pigments, dyes, reinforcing agents and fillers, ultraviolet absorbers, lubricants, release agents, nucleating agents,
Plasticizers, flow improvers, antistatic agents, antibacterial agents and the like can be added.

The above-mentioned additives may be added while the polycarbonate resin obtained by melt polycondensation is in a molten state immediately after the reaction, or may be added again after pelletizing the polycarbonate resin. Further, a plurality of additives may be added at different addition times.

When adding to the molten resin immediately after the reaction, it is added to the resin extracted from the reaction vessel, fed into a horizontal kneader, uniformly kneaded, and then pelletized as it is. A method is preferably used in which the extracted resin is fed into a horizontal kneader, added by side feed in the middle of the kneader, uniformly kneaded, and then pelletized as it is.

When added to the pelletized resin,
After the pellets and the above additives are dispersed and mixed by a high-speed mixer represented by a turnbull mixer, a Henschel mixer, a ribbon blender, and a super mixer, a method of melt-kneading with a kneader such as an extruder, a Banbury mixer, or a roll is appropriately selected. You.

[0038]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples.

Example 1 52.5 g of pentacyclopentadecane dimethanol
(0.2 mol), 43.3 g of diphenyl carbonate
(0.202 mol), and sodium hydrogen carbonate 5 × 1
0 ^-4 g (6 × 10 ^-6 mol) was placed in a 300 ml four-necked flask equipped with a stirrer and a distilling device, heated to 180 ° C. under a nitrogen atmosphere of 760 mmHg, and stirred for 30 minutes. Thereafter, the degree of decompression was adjusted to 150 mmHg, and at the same time, the temperature was raised to 200 ° C. at a rate of 60 ° C./hr.
The transesterification reaction was performed while maintaining the temperature for 0 minutes. Further, the temperature was raised to 225 ° C. at a rate of 75 ° C./hr, and 40 minutes after the completion of the temperature raising, the pressure was reduced to 1 mmHg or less over 1 hour while maintaining the temperature. Thereafter, 105 ° C /
The temperature was raised to 235 ° C. at a rate of hr and the reaction was carried out under stirring for a total of 6 hours. After the reaction was completed, nitrogen was blown into the reactor to return to normal pressure, and the produced polycarbonate was taken out. Table 1 shows the measurement results of the physical properties of the polycarbonate resin.

Example 2 In Example 1, 26.2 g (0.1 mol) of pentacyclopentadecanedimethanol, 22.8 g (0.1 mol) of 2,2-bis (4-hydroxyphenyl) propane, diphenyl carbonate 43.5 g (0.203
Mol), 5 × 10 ⁻⁴ g of sodium hydrogen carbonate (6 × 10 ⁻⁶⁾
Mol)), except for using the same compound. Table 1 shows the measurement results of physical properties of the obtained polycarbonate resin.

Example 3 In Example 1, 15.7 g (0.06 mol) of pentacyclopentadecanedimethanol, 2,2-bis (4-
(Hydroxyphenyl) propane 32.0 g (0.14 mol), diphenyl carbonate 43.5 g (0.203
Mol), 5 × 10 ⁻⁴ g of sodium hydrogen carbonate (6 × 10 ⁻⁶⁾
Mol)), except for using the same compound. Table 1 shows the measurement results of physical properties of the obtained polycarbonate resin.

Comparative Example 1 In Example 1, 45.7 g (0.2 mol) of 2,2-bis (4-hydroxyphenyl) propane, 44.1 g (0.206 mol) of diphenyl carbonate, 5 × sodium hydrogencarbonate Using 10 ⁻⁵ g (6 × 10 ⁻⁷ mol)
Without using pentacyclopentadecane dimethanol, and after reducing the degree of vacuum to 1 mmHg or less, 105 ° C / hr
The same operation as in Example 1 was performed, except that the temperature was raised to 280 ° C. at a rate of and the reaction was performed under stirring for a total of 7 hours. Table 1 shows the measurement results of physical properties of the obtained polycarbonate resin.

Comparative Example 2 A commercially available polymethyl methacrylate was purchased. Table 1 shows the physical property measurement results.

The physical properties in Table 1 are measured by the following methods. 1) Refractive index (n _D ), Abbe number (ν _D ): Measured with an ATAGO refractometer. 2) a polystyrene equivalent weight average molecular weight (M _W): measured by GPC using chloroform as a developing solvent. 3) Glass transition temperature (T _g ): measured by a differential scanning calorimeter. 4) Thermal decomposition onset temperature (T _d ): 1 in a nitrogen stream with a thermobalance
The temperature at which the% weight loss was measured. Heating rate is 10 ° C / m
in. 5) Photoelastic coefficient: thickness 100 by ellipsometer
μm cast film, laser wavelength 633n
m, and calculated from the measurement of birefringence with respect to the change in load. 6) Falling ball impact strength: A steel ball was naturally dropped from a height of 127 cm on a pressed test piece having a diameter of 40 mm and a thickness of 3 mm, and the result was indicated by the weight of the largest steel ball that did not destroy the test piece.

In Table 1, the following abbreviations were used as compound names. PCPDM: pentacyclopentadecane dimethanol BPA: 2,2-bis (4-hydroxyphenyl) propane PMMA: polymethyl methacrylate

[0046]

[Table 1]

[0047]

The polycarbonate resin according to the present invention comprises:
Excellent transparency and heat resistance of aliphatic polycarbonate resin,
It is a novel aliphatic polycarbonate resin and aliphatic-aromatic copolymer polycarbonate resin having a low photoelastic coefficient while maintaining properties such as good refractive index-Abbe number balance, and various lenses including an optical disc substrate, a prism,
It is very useful as a material for plastic optical products such as optical fibers.

Continued on the front page F-term (reference) 4J029 AB01 AB04 AC02 AD10 AE04 AE05 BB13A BB13B BD06A BE05A BE05B BF03 BF14A BF14B BG08X BG24X BH02 DB07 DB11 DB13 HA01 HC02 HC03 HC04A HC05A HC05B J091 J121C01 J031J01J031 JF051 JF131 JF141 JF151 JF161 KE05 KH08 LA04 LA05 LA10 5D029 KA08 KC06 KC07

Claims (11)

[Claims] 1. A polycarbonate resin comprising a structural unit represented by structural formula (1) and / or structural formula (2). Embedded image Embedded image 2. A polycarbonate resin comprising a structural unit represented by the structural formula (1) and / or (2) and a structural unit represented by a structural formula (3). Embedded image (Wherein R ₁ and R ₂ are each independently a hydrogen atom,
A halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxyl group having 1 to 20 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a cycloalkoxyl group having 6 to 20 carbon atoms, or Represents an aryloxy group having 6 to 20 carbon atoms. P and q represent the number of substituents, and are integers from 0 to 4. X is R ₃ and R ₄ are each independently a hydrogen atom,
An alkyl group having 1 to 12 carbon atoms or 6 to 20 carbon atoms
And R ₃ and R ₄ may combine with each other to form a ring. ) 3. The structural formulas (1), (2) and (3)
The molar ratio of the structural unit represented by (3) / [(1) +
(2)] is 5 / 95-70 / 30, The polycarbonate resin of Claim 2. 4. The polycarbonate resin according to claim 3, which has a photoelastic coefficient of 60 × 10 ⁻¹² m ² / N or less. 5. The polycarbonate resin according to claim ₃ , wherein R ₃ and R ₄ in the structural formula (3) are a methyl group. 6. The polycarbonate resin according to claim 3, wherein the general formula (4), the general formula (5) and the general formula (6) are melt-polycondensed with a carbonic acid diester in the presence of a basic compound catalyst. Production method. Embedded image Embedded image Embedded image (Wherein R ₁ and R ₂ are each independently a hydrogen atom,
A halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxyl group having 1 to 20 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a cycloalkoxyl group having 6 to 20 carbon atoms, or Represents an aryloxy group having 6 to 20 carbon atoms. P and q represent the number of substituents, and are integers from 0 to 4. X is R ₃ and R ₄ are each independently a hydrogen atom,
An alkyl group having 1 to 12 carbon atoms or 6 to 20 carbon atoms
And R ₃ and R ₄ may combine with each other to form a ring. ) 7. A catalyst comprising 10 ^-9 to 10 ^-3 mol of a basic compound with respect to 1 mol in total of the general formulas (4), (5) and (6). Item 7. A method for producing a polycarbonate resin according to Item 6. 8. The method for producing a polycarbonate resin according to claim 5, wherein R ₅ and R _{6 in} the general formula (6) are methyl groups. 9. The polycarbonate resin according to claim 1, which is used for an optical material. 10. The polycarbonate resin according to claim 9, which is used for an optical disk. 11. The polycarbonate resin according to claim 9, which is used for an eyeglass lens material.