JP2004359932A - Polycarbonate resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new polycarbonate resin with higher rigidity and superior mechanical properties balance than those of conventional aromatic polycarbonate resins. <P>SOLUTION: The polycarbonate resin has a polystyrene converted weight average molecular weight (Mw) of 20,000-200,000 and is prepared by a carbonate binding of several specific dihydroxy compounds and a carbonic acid diester or phosgene. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a novel transparent polycarbonate resin having excellent heat resistance and mechanical properties.

  At present, polycarbonate resins composed of 2,2-bis (4-hydroxyphenyl) propane (commonly known as bisphenol A) are used in a wide range of fields because of their high transparency, good mechanical property balance, and high heat resistance. ing. Specifically, there are a wide variety of applications, from optical materials such as optical discs, prisms, optical lenses, and optical films to transparent structural materials such as glass substitutes for glass, transparent plates for fitting window frames, and transparent roof panels for arcades. .

  However, since the polycarbonate resin composed of bisphenol A has a flexural modulus of 2300 MPa, it has a drawback that it cannot be used in a field requiring higher rigidity. Therefore, in order to increase rigidity, it is widely practiced to mix an inorganic filler such as glass fiber, carbon fiber, and boron nitride. However, the kneading of such an inorganic filler significantly lowers the transparency, so that there is a problem that the inorganic filler cannot be used in a field where transparency is required. For example, there is an example in which a glass having a refractive index difference of 0.01 or less is blended with a polycarbonate resin, but the haze is large and the transparency is completely insufficient (for example, see Patent Document 1). Further, there is an example in which glass and a plasticizer having a refractive index of 1.570 to 1.600 are blended in a polycarbonate resin, but the haze is large and the transparency is completely insufficient (for example, see Patent Document 2).

JP-A-06-184424 JP-A-2002-020610

  An object of the present invention is to solve the above-mentioned problems in the prior art, and to provide a novel polycarbonate resin having high rigidity and excellent balance of mechanical properties.

  The present inventors have conducted intensive studies to solve the above problems, and as a result, a dihydroxy compound represented by the general formula (1) and a dihydroxy compound represented by the general formula (2), A compound (6) comprising at least one compound selected from dihydroxy compounds represented by (4) and (5) is carbonate-bonded with a carbonic acid diester or phosgene, and has a polystyrene equivalent weight average molecular weight (Mw) of 20, The present inventors have found that the above problems can be solved by a polycarbonate resin having a molecular weight of 000 to 200,000, and reached the present invention.

（式中、Ｒ_１およびＲ_２は、それぞれ独立に、水素原子または炭素数１〜８のアルキル基、炭素数５〜２０のシクロアルキル基、炭素数１〜８のアルコキシル基、炭素数６〜１０のアリール基または炭素数６〜１０のアリールオキシ基である。また、Ｘは、単結合、酸素原子、硫黄原子、スルホン基、炭素数２〜１０のアルキリデン基、炭素数５〜１２のシクロアルキリデン基、炭素数７〜１５のアリールアルキリデン基、フルオレニリデン基またはα，α，α’，α’−テトラメチルキシリデン基である。）

(Wherein, R ₁ and R ₂ are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms, X is an aryl group having 10 or an aryloxy group having 6 to 10 carbon atoms, and X is a single bond, an oxygen atom, a sulfur atom, a sulfone group, an alkylidene group having 2 to 10 carbon atoms, or a cycloalkyl having 5 to 12 carbon atoms. An alkylidene group, an arylalkylidene group having 7 to 15 carbon atoms, a fluorenylidene group, or an α, α, α ′, α′-tetramethylxylidene group.)

（式中、Ｒ_３およびＲ_４は、それぞれ独立に、炭素数３〜１０のアルキル基または炭素数５〜２０のシクロアルキル基である。Ｒ_５およびＲ_６は、それぞれ独立に、メチル基またはエチル基である。また、Ｙは、単結合、酸素原子、硫黄原子、スルホン基、炭素数１〜８のアルキリデン基、炭素数５〜１２のシクロアルキリデン基、炭素数７〜１５のアリールアルキリデン基、フルオレニリデン基またはα，α，α’，α’−テトラメチルキシリデン基である。）

(Wherein, R ₃ and R ₄ are each independently an alkyl group having 3 to 10 carbon atoms or a cycloalkyl group having 5 to 20 carbon atoms. R ₅ and R ₆ are each independently a methyl group or And Y represents a single bond, an oxygen atom, a sulfur atom, a sulfone group, an alkylidene group having 1 to 8 carbon atoms, a cycloalkylidene group having 5 to 12 carbon atoms, or an arylalkylidene group having 7 to 15 carbon atoms. , Fluorenylidene group or α, α, α ′, α′-tetramethylxylidene group.)

  According to the present invention, a novel transparent polycarbonate resin having higher rigidity than a conventional polycarbonate resin comprising bisphenol A can be obtained, which is very useful. The polycarbonate resin is very useful because it has a low birefringence and can be used not only for optical materials such as optical discs, prisms, optical lenses, and optical films but also for structural materials such as cups and transparent resin plates.

  The polycarbonate resin used in the present invention comprises a dihydroxy compound represented by the general formula (1) and a dihydroxy compound represented by the general formula (2), and a dihydroxy compound represented by the structural formulas (3), (4) and (5). And a compound (6) composed of at least one selected from dihydroxy compounds to be carbonate-bonded with a carbonic acid diester or phosgene.

  The compound represented by the general formula (1) is specifically, 2,2-bis (4-hydroxyphenyl) propane (commonly known as bisphenol A), 2,2-bis (4-hydroxy-3-methylphenyl) Propane, 2,2-bis (4-hydroxy-3-ethylphenyl) propane, 2,2-bis (4-hydroxy-3-isopropylphenyl) propane, 2,2-bis (4-hydroxy-3- (1 -Methylpropyl) phenyl) propane, 2,2-bis (4-hydroxy-3-tert-butylphenyl) propane, 2,2-bis (4-hydroxy-3-cyclohexylphenyl) propane, 2,2-bis ( 4-hydroxy-3-phenylphenyl) propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl)- -Methylbutane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxy-3-methylphenyl) cyclohexane, 1,1-bis (4-hydroxy-3-ethylphenyl) cyclohexane, 1,1-bis (4-hydroxy-3- (1-methylethyl) phenyl) cyclohexane, 1,1-bis (4-hydroxy-3-tert-butylphenyl) cyclohexane, 1,1-bis (4-hydroxy -3- (1-methylpropyl) phenyl) cyclohexane, 1,1-bis (4-hydroxy-3-cyclohexylphenyl) cyclohexane, 1,1-bis (4-hydroxy-3-phenylphenyl) cyclohexane, 9,9 -Bis (4-hydroxy-3-methylphenyl) fluorene, 4,4 '-(1,3- Phenylene-bis (1-methylethylidene)) bisphenol, 4,4 ′-(1,4-phenylene-bis (1-methylethylidene)) bisphenol, 4,4 ′-(1,3-phenylene-bis (1- Methylethylidene)) bis (2-methylphenol), 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 4,4′-thiodiphenol, bis (4-hydroxyphenyl) sulfone, 1,1-bis (4-hydroxy-3-tert-butylphenyl) -1-phenylethane, 4,4 '-Dihydroxybiphenyl and the like. Among these, bisphenol A is preferably used.

  The compound represented by the general formula (2) is, specifically, 1,1-bis (4-hydroxy-5-tert-butyl-2-methylphenyl) butane (commonly called: 4,4′-butylidenebis (3- Methyl-6-tert-butylphenol)), 1,1-bis (4-hydroxy-5-isopropyl-2-methylphenyl) butane, 1,1-bis (4-hydroxy-5-cyclohexyl-2-methylphenyl) Butane, 1,1-bis (4-hydroxy-5-tert-butyl-2-methylphenyl) cyclohexane, 1,1-bis (4-hydroxy-5-tert-butyl-2-methylphenyl) -1-phenyl Methane, 4,4'-thiobis (3-methyl-6-tert-butylphenol), 4,4 '-(1,3-phenylene-bis (1-methylethylidene) Bis- (2-cyclohexyl-5-methylphenol), 4,4 ′-(1,4-phenylene-bis (1-methylethylidene)) bis- (2-cyclohexyl-5-methylphenol) and the like are exemplified. . Among these, 4,4'-butylidenebis (3-methyl-6-tert-butylphenol) is preferably used.

  The compound represented by the structural formula (3) is 2,2'-methylenediphenol (commonly called 2,2'-bisphenol F), and the compound represented by the structural formula (4) is 2,4'-methylenediphenol. (Commonly known as 2,4'-bisphenol F), and the compound represented by the structural formula (5) is 4,4'-methylenediphenol (commonly known as 4,4'-bisphenol F).

  The polycarbonate resin according to the present invention has a random, block or alternating copolymer structure and exhibits excellent mechanical property balance, heat resistance, fluidity, transferability and molding properties. The polycarbonate resin according to the present invention may contain a small amount of another bisphenol as long as the above properties are not impaired. Specifically, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, bis (4-hydroxy-3,5-dimethylphenyl) methane, 3,3 ′, 5,5′-tetra Methyl-4,4'-biphenol and the like are exemplified.

  The preferred glass transition temperature of the polycarbonate resin in the present invention is from 105 ° C to 180 ° C. More preferably, the temperature is 115 ° C to 170 ° C. When the glass transition temperature is lower than 105 ° C., heat resistance deteriorates, and the use environment is limited, which is not preferable. On the other hand, if the glass transition temperature is higher than 180 ° C., the flowability deteriorates, the molding conditions become severe, and silver is generated due to decomposition, which is not preferable. Further, the glass transition temperature is suppressed to a low molecular weight in order to ensure the flowability. Is not preferred because it becomes brittle.

  The polystyrene equivalent weight average molecular weight (Mw) of the polycarbonate resin used in the present invention is from 20,000 to 200,000, more preferably from 30,000 to 120,000, and still more preferably from 35,000 to 80,000. . If the Mw is lower than 20,000, the molded body becomes brittle, and if the Mw is higher than 200,000, the fluidity in a molten state deteriorates and the molding conditions become severe, which is not preferable.

  The molded article made of the polycarbonate resin used in the present invention preferably has a flexural modulus of more than 2400 MPa and a flexural strength of more than 85 MPa. More preferably, the flexural modulus is 2500 to 4000 MPa and the flexural strength is 92 to 150 MPa. If the flexural modulus is not more than 2400 MPa, the molded body is likely to bend, which is not preferable. Further, when the bending strength is 85 MPa or less, the molded body is easily broken, which is not preferable.

  In the present invention, the compound (6) is used in addition to the compound represented by the general formula (1) and the compound represented by the general formula (2). Compound (6) comprises at least one compound selected from dihydroxy compounds represented by structural formulas (3), (4) and (5). However, from the viewpoint of improving the flexural modulus, (3) or (4) is preferably contained. Therefore, the compound (6) is specifically (3), (4), (3) + (4), (3) + (5), (4) + (5) or (3) + (4) ) + (5) is preferably used. Among them, the combination of (3) + (4) or (3) + (4) + (5) is particularly preferable. The ratio of the isomers is not particularly limited, but (5) / (6) is preferably 0.7 or less. As for the ratio of (1), (2) and (6), the molar ratio (1) / [(1) + (2)] is preferably 0.1 to 0.9, more preferably. Is 0.2 to 0.8. Further, the molar ratio (6) / [(1) + (2) + (6)] is preferably from 0.01 to 0.6, and more preferably from 0.1 to 0.4.

  Hereinafter, a method for producing a polycarbonate resin according to the present invention will be described. As one of the production methods, a known melt polycondensation method in which a dihydroxy compound and a carbonic acid diester are reacted in the presence of a basic catalyst is used.

  Examples of the carbonic acid diester include diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, m-cresyl carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, and the like. Of these, diphenyl carbonate is particularly preferred. The carbonic acid diester is preferably used at a ratio of 0.97 to 1.20 mol, more preferably at a ratio of 0.99 to 1.10 mol, based on 1 mol of the total of the dihydroxy compound.

  Examples of the basic compound catalyst include an alkali metal compound and / or an alkaline earth metal compound and a nitrogen-containing compound.

  Examples of such 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, and amines. These compounds are preferably used, and these compounds can be used alone or in combination.

  Specific examples of the alkali metal compound include sodium hydroxide, potassium hydroxide, cesium hydroxide, lithium hydroxide, sodium hydrogen carbonate, sodium carbonate, potassium carbonate, cesium carbonate, lithium carbonate, sodium acetate, potassium acetate, and acetic acid. Cesium, lithium acetate, sodium stearate, potassium stearate, cesium stearate, lithium stearate, sodium borohydride, sodium borohydride, sodium benzoate, potassium benzoate, cesium benzoate, lithium benzoate, hydrogen phosphate Disodium, dipotassium hydrogen phosphate, dilithium hydrogen phosphate, disodium phenylphosphate, disodium salt of bisphenol A, 2 potassium salt, 2 cesium salt, 2 lithium salt, phenol sodium salt, potassium salt Cesium salt, lithium salt or the like is used.

  Specific examples of the alkaline earth metal compound include magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, magnesium hydrogen carbonate, calcium hydrogen carbonate, strontium hydrogen carbonate, barium hydrogen carbonate, magnesium carbonate, and calcium carbonate. Strontium carbonate, barium carbonate, magnesium acetate, calcium acetate, strontium acetate, barium acetate, magnesium stearate, calcium stearate, calcium benzoate, magnesium phenyl phosphate and the like are used.

  Specific examples of the nitrogen-containing compound include alkyl, aryl, and groups having alkyl, aryl, and groups such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and trimethylbenzylammonium hydroxide. Quaternary ammonium hydroxides; tertiary amines such as triethylamine, dimethylbenzylamine and triphenylamine; secondary amines such as diethylamine and dibutylamine; primary amines such as propylamine and butylamine; 2-methylimidazole; Imidazoles such as phenylimidazole and benzimidazole; or ammonia, tetramethylammonium borohydride, tetrabutylammonium borohydride, Tetrabutylammonium tetraphenylborate, basic or basic salts such as tetraphenyl ammonium tetraphenylborate, or the like is used.

These catalysts are used at a ratio of 10 ⁻⁹ to 10 ⁻³ mol, preferably at a ratio of 10 ⁻⁷ to 10 ⁻⁵ mol, per 1 mol of the total of the dihydroxy compound.

  In the melt polycondensation method according to the present invention, a 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 performed at a temperature of 120 to 260 ° C., preferably 180 to 240 ° C., for 0.1 to 5 hours, preferably 0.5 to 3 hours. Next, the reaction temperature is increased while increasing the degree of pressure reduction of the reaction system to carry out the reaction between the dihydroxy compound and the carbonic acid diester. Finally, the reaction is carried out under a reduced pressure of 1 mmHg or less for 0.3 to 10 hours at a temperature of 200 to 350 ° C. Perform a condensation reaction. Such a reaction may be carried out continuously or batchwise. The reaction apparatus used for performing the above reaction was equipped with paddle wings, lattice wings, glasses wings, and the like, even if the reactor was a vertical type equipped with an anchor type stirring blade, a max blend stirring blade, a helical ribbon type stirring blade, and the like. A horizontal type or an extruder type equipped with a screw may be used, and it is preferable to use a reaction apparatus in which these are appropriately combined in consideration of the viscosity of the polymer.

  After the completion of the polymerization reaction, the polycarbonate resin according to the present invention removes or deactivates the catalyst in order to maintain thermal stability and hydrolysis stability. In general, a known method of deactivating a catalyst by adding an acidic substance is suitably performed. Specific examples of these substances include aromatic sulfonic acids such as p-toluenesulfonic acid and dodecylbenzenesulfonic acid, butyl p-toluenesulfonic acid, hexyl p-toluenesulfonic acid, octyl p-toluenesulfonic acid, Aromatic sulfonic acid esters such as phenyltoluenesulfonic acid phenyl and p-toluenesulfonic acid phenethyl, aromatic sulfonic acid salts such as p-toluenesulfonic acid tetrabutylphosphonium salt, stearic acid chloride, benzoyl chloride, p-toluenesulfonic acid Organic halides such as chloride, alkyl sulfates such as dimethyl sulfate, and organic halides such as benzyl chloride are preferably used.

  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 a temperature of 200 to 350 ° C. may be provided. For this purpose, paddle blades, lattice blades, glasses A horizontal apparatus equipped with a stirring blade having excellent surface renewing ability, such as a blade, or a thin film evaporator is suitably used.

  As a second method for producing a polycarbonate resin according to the present invention, an interfacial polymerization method in which a dihydroxy compound is reacted with phosgene in the presence of a solvent, a terminal stopper and an acid binder is used. Usually, a dihydroxy compound and a terminal stopper are dissolved in an aqueous solution of an acid binder, and the reaction is carried out in the presence of an organic solvent.

  As the acid binding agent, for example, pyridine or an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is preferably used, and as the solvent, for example, methylene chloride, chloroform, chlorobenzene, xylene and the like are preferable. Used for Further, in order to accelerate the polymerization reaction, a tertiary amine such as triethylamine or a quaternary ammonium salt such as tetra-n-butylammonium bromide is used as a catalyst.

  In addition, as a terminal terminator used for controlling the degree of polymerization, a monofunctional hydroxy compound such as phenol, p-tert-butylphenol, p-cumylphenol, or long-chain alkyl-substituted phenol is used.

  Further, if desired, a small amount of an antioxidant such as sodium sulfite and sodium hydrosulfite may be added.

  The reaction is carried out usually at a temperature of 0 to 150 ° C, preferably 5 to 40 ° C. The reaction time depends on the reaction temperature, but is usually 0.5 minutes to 10 hours, preferably 1 minute to 2 hours. During the reaction, the pH of the reaction system is preferably maintained at 10 or more.

  It is preferable to add an antioxidant, an ultraviolet absorber, a release agent, a flow improver, an antistatic agent, a lubricant, a dye, a pigment, an antibacterial agent, and the like to the polycarbonate resin in the present invention.

  Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

[Measuring method]
1) Weight average molecular weight (Mw) in terms of polystyrene: Measured by GPC using chloroform as a developing solvent. The calibration curve was created using polystyrene of known molecular weight and small dispersion.
2) Glass transition temperature (Tg): measured using DSC (differential scanning calorimeter).
3) Photoelastic coefficient: A cast film having a thickness of 100 μm was prepared using methylene chloride as a solvent, and measured with an ellipsometer DVA-36L manufactured by Mizojiri Optical Industrial Co., Ltd.
4) Bending test piece: injection molded by MIN7 manufactured by Niigata Iron Works. The size of the test piece is 89 mm in length, 12.65 mm in width, and 3.23 mm in height.
5) Flexural modulus and flexural strength: measured by Autograph AG-5000B manufactured by Shimadzu Corporation.

Example 1
4.109 kg (18.00 mol) of 2,2-bis (4-hydroxyphenyl) propane, 6.887 kg (18.00 mol) of 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), bisphenol 1.802 kg of F composition (9,000 mol, of which 2,2'-form: 16.6%, 2,4'-form: 48.3%, 4,4'-form: 35.1%) , 10.41 kg (48.60 mol) of diphenyl carbonate and 0.01890 g (2.250 × 10 ⁻⁴ mol) of sodium bicarbonate were placed in a 50 liter reactor equipped with a stirrer and a distilling apparatus, and placed under a nitrogen atmosphere of 760 Torr. Heated to 200 ° C. over 1 hour.
Thereafter, the degree of reduced pressure was adjusted to 100 Torr over 20 minutes, and the mixture was maintained at 200 ° C. and 100 Torr for 50 minutes to perform a transesterification reaction. Further, the temperature was increased to 235 ° C. at a rate of 60 ° C./hr while adjusting the pressure to 15 Torr over 10 minutes, and the transesterification reaction was performed while maintaining the temperature and pressure for 40 minutes. Thereafter, the temperature was adjusted to 1 Torr or less over 20 minutes, and at the same time, the temperature was raised to 265 ° C. at a rate of 90 ° C./hr. After completion of the reaction, nitrogen was blown into the reactor to increase the pressure, and the produced polycarbonate resin was withdrawn while pelletizing. Mw = 52,900, Tg = 145 ° C., and photoelastic coefficient = 52 × 10 ⁻¹² m ² / N of the obtained polycarbonate resin. 10.0 kg of this polycarbonate resin was vacuum-dried at 100 ° C. for 24 hours, and n-hexyl p-toluenesulfonate was kneaded with an extruder by adding 25 ppm of 10 times mol of sodium hydrogencarbonate in the resin to the resin. And pelletized to obtain pellets. The Mw of the pellet was 52,500.
The pellets were vacuum-dried at 120 ° C. for 3 hours, and injection-molded at 270 ° C. cylinder temperature and 92 ° C. mold temperature by MIN7 to obtain bending test pieces. The bending test piece was good in appearance. After the bending test piece was allowed to stand at 25 ° C. and 50% RH for 48 hours, mechanical properties were measured by an autograph. The flexural modulus was 2700 MPa and the flexural strength was 92 MPa (yield), indicating high rigidity.

Example 2
4.109 kg (18.00 mol) of 2,2-bis (4-hydroxyphenyl) propane, 4,4′-butylidenebis (3-methyl-6) were placed in a 110 L reactor having a stirrer, a phosgene blowing device, and a cooling device. 6.887 kg (18.00 mol), 1.802 kg of bisphenol F composition (9,000 mol, of which 2,2′-form: 48.0%, 2,4′-form: 52) 5.0%, 4,4'-form: 0.0%), 50% of 7.2% L aqueous sodium hydroxide solution (90.00 mol of sodium hydroxide) and 22.17 g (0.1267 mol) of sodium hydrosulfite Was dissolved under stirring, and further, with stirring, 28.7 L of methylene chloride and 1.826 L of a 48.5% aqueous sodium hydroxide solution (0.02214 L of sodium hydroxide) were added. ), 356.1 g (2.370 mol) of p-tert-butylphenol as a molecular weight regulator and 327.6 ml (2.353 mol) of triethylamine as a catalyst were added. Under stirring, 5.734 kg (49.90 mol) of phosgene was blown into the mixture over 3 hours while maintaining the temperature of the reaction solution at 25 ° C. After the blowing was completed, the mixture was further stirred at 25 ° C. for 3 hours to terminate the reaction. Was. The stirring was stopped, the methylene chloride layer was separated from the mixed solution, and washing with water was repeated 5 times.N-heptane corresponding to 0.25 parts by weight of the methylene chloride solution was added and mixed, and the mixed solution was dropped into warm water, The temperature was raised to 100 ° C. and the solvent was distilled off to obtain a slurry-like polycarbonate resin powder. This powder was filtered and dried at 110 ° C. for 8 hours. The obtained polycarbonate resin had 13.0 kg, Mw = 53,200, Tg = 140 ° C., and photoelastic coefficient = 49 × 10 ⁻¹² m ² / N. 10.0 kg of this polycarbonate resin was vacuum-dried at 100 ° C. for 24 hours and pelletized into a strand through an extruder to obtain a pellet. The Mw of the pellet was 53,000.
The pellets were vacuum-dried at 120 ° C. for 3 hours and then injection-molded at 270 ° C. cylinder temperature and 82 ° C. mold temperature by MIN7 to obtain bending test pieces. The bending test piece was good in appearance. After the bending test piece was allowed to stand at 25 ° C. and 50% RH for 48 hours, mechanical properties were measured by an autograph. Flexural modulus = 2800 MPa, flexural strength = 97 MPa (yield), indicating high rigidity.

Comparative Example 1
In Example 1, 5.137 kg (22.50 mol) of 2,2-bis (4-hydroxyphenyl) propane and 8.608 kg (22.50 kg) of 4,4′-butylidenebis (3-methyl-6-tert-butylphenol). The same operation as in Example 1 was carried out except that the polymerization was carried out under stirring at 265 ° C. and 1 Torr or less for 85 minutes without using the bisphenol F composition. After the reaction, the obtained polycarbonate resin had Mw = 50,900, Tg = 160 ° C., photoelastic coefficient = 52 × 10 ⁻¹² m ² / N, and Mw = 50, after the additives were kneaded and extruded. 700.
The pellets were vacuum-dried at 120 ° C. for 3 hours, and then injection-molded by MIN7 at a cylinder temperature of 280 ° C. and a mold temperature of 100 ° C. to obtain a bending test piece. The bending test piece was good in appearance. After the bending test piece was allowed to stand at 25 ° C. and 50% RH for 48 hours, mechanical properties were measured by an autograph. The stiffness was low, with a flexural modulus of 2200 MPa and a flexural strength of 80 MPa (yield).

Comparative Example 2
In Example 1, 10.27 kg of 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) was used without using the 4,4′-butylidenebis (3-methyl-6-tert-butylphenol) and bisphenol F composition. (45.00 mol) was carried out in the same manner as in Example 1 except that (45.00 mol) was used. After the reaction, the obtained polycarbonate resin had Mw = 51,400, Tg = 151 ° C., photoelastic coefficient = 78 × 10 ⁻¹² m ² / N, and Mw = 51, after the additives were kneaded and extruded. It was 200.
The pellets were vacuum-dried at 120 ° C. for 3 hours, and then injection-molded by MIN7 at a cylinder temperature of 290 ° C. and a mold temperature of 105 ° C. to obtain a bending test piece. The bending test piece was good in appearance. After the bending test piece was allowed to stand at 25 ° C. and 50% RH for 48 hours, mechanical properties were measured by an autograph. The flexural modulus was 2300 MPa and the flexural strength was 85 MPa (yield), and the rigidity was low.

Claims (6)

At least one selected from dihydroxy compounds represented by the general formulas (1) and (2) and dihydroxy compounds represented by the structural formulas (3), (4) and (5) A polycarbonate resin having a weight-average molecular weight (Mw) in terms of polystyrene of 20,000 to 200,000, obtained by binding a compound (6) consisting of:

(Wherein, R ₁ and R ₂ are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms, X is an aryl group having 10 or an aryloxy group having 6 to 10 carbon atoms, and X is a single bond, an oxygen atom, a sulfur atom, a sulfone group, an alkylidene group having 2 to 10 carbon atoms, or a cycloalkyl having 5 to 12 carbon atoms. An alkylidene group, an arylalkylidene group having 7 to 15 carbon atoms, a fluorenylidene group, or an α, α, α ′, α′-tetramethylxylidene group.)

(Wherein, R ₃ and R ₄ are each independently an alkyl group having 3 to 10 carbon atoms or a cycloalkyl group having 5 to 20 carbon atoms. R ₅ and R ₆ are each independently a methyl group or And Y represents a single bond, an oxygen atom, a sulfur atom, a sulfone group, an alkylidene group having 1 to 8 carbon atoms, a cycloalkylidene group having 5 to 12 carbon atoms, or an arylalkylidene group having 7 to 15 carbon atoms. , Fluorenylidene group or α, α, α ′, α′-tetramethylxylidene group.)

The polycarbonate resin according to claim 1, wherein the ratio of the isomer (5) in the compound (6) is 0.7 or less. The polycarbonate resin according to claim 1, wherein in the general formula (1), R ₁ is a hydrogen atom and X is an isopropylidene group. The polycarbonate resin according to claim 1, wherein in the general formula (2), R ₂ is a tert-butyl group, and R ₃ is a methyl group. The polycarbonate resin according to claim 1, wherein in the general formula (2), Y is a butylidene group. The polycarbonate resin according to claim 1, wherein the glass transition temperature (Tg) is 105 to 180 ° C and the flexural modulus is greater than 2400 MPa.