Polycarbonate resin and optical member using the same

Abstract

To provide a polycarbonate resin that achieves small orientation birefringence, while exhibiting a high refractive index and a high glass transition temperature.SOLUTION: A polycarbonate resin includes a repeating unit represented by formula (1) and / or formula (2), a repeating unit having a spirofluorene structure, and a repeating unit represented by bisphenol TMC, wherein the polycarbonate resin has a weight-average molecular weight Mw of 10,000 or greater.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a polycarbonate resin and an optical member using the resin. [Background technology]

[0002] Polycarbonate resins derived from bisphenol A, obtained by reacting 2,2-bis(4-hydroxyphenyl)propane (commonly known as bisphenol A) with phosgene or carbonate esters, have excellent heat resistance and transparency, as well as excellent mechanical properties such as impact resistance. Therefore, they are widely used not only as structural materials but also as optical materials, such as optical disk substrates, various lenses, prisms, and optical fibers. However, polycarbonate resins derived from bisphenol A suffer from the problem of high birefringence due to molecular orientation and residual stress during molding. Therefore, with the recent expansion of optical material applications, there is a strong demand for the development of materials with even lower birefringence. As a method for reducing the birefringence of polycarbonate resins, for example, Patent Document 1 describes a polycarbonate resin with a low photoelastic coefficient obtained by copolymerizing bisphenol A with pentacyclopentadecanedimethanol (hereinafter sometimes abbreviated as PCPDM). Patent Document 2 proposes a method for producing a carbonate derivative without using a base by photoreacting halogenated methane with a specific amount of a hydroxyl group-containing compound in the presence of oxygen, and cites, as an example of the production method, a copolymerized polycarbonate of 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene (hereinafter sometimes abbreviated as BPEF) and PCPDM. Patent Documents 3 and 4 describe a polycarbonate resin with low orientation birefringence obtained by copolymerizing BPEF with 3,9-bis(2-hydroxy-1,1-dimethylethyl)-2,4,8,10-tetraoxaspiro(5,5)undecane (hereinafter sometimes abbreviated as SPG) and 4,4'-(3,3,5-trimethylcyclohexylidene)bisphenol (hereinafter sometimes abbreviated as BisTMC). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-302860 [Patent Document 2] WO2020 / 100977 issue [Patent Document 3] WO2019 / 188702 issue [Patent Document 4] WO2022 / 004239 issue Summary of the Invention [Problem to be solved by the invention]

[0004] The polycarbonate resin made from bisphenol A and PCPDM described above had issues such as high orientation birefringence, as well as low refractive index and glass transition temperature. Furthermore, the resulting resin had a high molecular weight, making it unsuitable for injection molding and unable to be used for thin optical components such as imaging lenses. Furthermore, the weight-average molecular weight of the copolymer polycarbonate made from BPEF and PCPDM described above was extremely low at 3,360, making it insufficient for use as a structural or optical material. Furthermore, the polycarbonate resin made from BPEF, SPG, and BisTMC had room for improvement in terms of refractive index and glass transition temperature.

[0005] SUMMARY OF THE INVENTION An object of the present invention is to provide a polycarbonate resin having a small orientation birefringence, a high refractive index and a high glass transition temperature. [Means for solving the problem]

[0006] The present inventors have found that the above problems can be solved by the present invention having the following aspects. That is, the present invention is as follows.

[0007] <<Aspect 1>> A polycarbonate resin comprising a repeating unit represented by formula (1) and / or formula (2), a repeating unit represented by formula (3), and a repeating unit represented by formula (4), wherein the total content of the repeating units represented by formula (1) and / or formula (2) among all the repeating units of the resin is more than 0% but less than 50 mol%, and the polycarbonate resin has a weight average molecular weight Mw of 10,000 or more.

[0008] [ka] [ka] [ka] (In the formula, R 1 ~R 4 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. [ka] (In formula (4), n is a number ranging from 0 to 8, and each R represents an alkyl group having 1 to 3 carbon atoms.)

[0009] <<Aspect 2>> Aspect 2. The polycarbonate resin according to aspect 1, having a weight average molecular weight Mw of 10,000 or more and 60,000 or less. Aspect 3 3. The polycarbonate resin according to aspect 1 or 2, wherein the repeating units represented by formula (3) account for 10 mol % to 95 mol % of all repeating units in the resin. Aspect 4 Aspect 4. The polycarbonate resin according to any one of Aspects 1 to 3, wherein the repeating unit of formula (4) accounts for more than 0 mol % and not more than 45 mol % of all repeating units in the resin. Aspect 5 R in the formula (3) 1 ~R 4 Aspect 5. The polycarbonate resin according to any one of aspects 1 to 4, wherein is a hydrogen atom. Aspect 6 Aspect 6. The polycarbonate resin according to any one of aspects 1 to 5, wherein the repeating unit of formula (4) is a repeating unit derived from bisphenol TMC. Aspect 7 The absolute value of orientation birefringence is 10.0 × 10 -3 Aspect 7. The polycarbonate resin according to any one of aspects 1 to 6, wherein: Aspect 8 Photoelastic coefficient is 40 x 10 -12 The polycarbonate resin according to any one of aspects 1 to 7, having a viscosity of 100 Pa or less. Aspect 9 Aspect 9. The polycarbonate resin according to any one of aspects 1 to 8, having a refractive index nd of 1.550 or greater. Aspect 10 Aspect 10. The polycarbonate resin according to any one of aspects 1 to 9, having a glass transition temperature of 140° C. or higher. Aspect 11 An optical member made of the polycarbonate resin according to any one of aspects 1 to 10. Aspect 12 12. The optical member according to embodiment 11, wherein the optical member is an imaging lens. [Effects of the Invention]

[0010] The polycarbonate resin of the present invention has a small orientation birefringence, a high refractive index and a high glass transition temperature, and therefore has an exceptional industrial effect. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 shows the relationship between the refractive index and the Abbe number of the thermoplastic resin of the present invention and a conventional resin. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will now be described in more detail.

[0013] <Polycarbonate resin> The polycarbonate resin of the present invention is a polycarbonate resin containing repeating units represented by formula (1) and / or formula (2), repeating units represented by formula (3), and repeating units represented by formula (4), and the total content of repeating units represented by formula (1) and / or formula (2) among all repeating units of the resin is more than 0% but less than 50 mol%.

[0014] In the above-mentioned definition of mol%, the total of repeating units represented by formula (1) and / or formula (2) means the total units of formula (1) and formula (2) when the polycarbonate resin contains repeating units represented by formula (1) and formula (2), and means either one of the repeating units represented by formula (1) or formula (2) when the polycarbonate resin contains either one of the units contained.

[0015] [ka]

[0016] [ka]

[0017] [ka] (In the formula, R 1 ~R 4 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms.

[0018] [ka] (In formula (4), n is a number ranging from 0 to 8, and each R represents an alkyl group having 1 to 3 carbon atoms.)

[0019] The polycarbonate resin of the present invention has a weight-average molecular weight Mw of 10,000 or more, preferably 15,000 or more, and more preferably 20,000 or more. A weight-average molecular weight Mw of 10,000 or more is preferable because it has sufficient mechanical strength for use as a structural material or optical material. Furthermore, the weight-average molecular weight Mw is preferably 60,000 or less, more preferably 50,000 or less, even more preferably 40,000 or less, and even more preferably 30,000 or less. A weight-average molecular weight Mw of 60,000 or less is preferable because it provides excellent fluidity during injection molding. This is particularly preferable when the polycarbonate resin of the present invention is used for thin-walled optical components such as imaging lenses, because it provides excellent fluidity. The weight-average molecular weight Mw can be measured by GPC using polystyrene of known molecular weight as a standard sample and chloroform as a developing solvent.

[0020] The polycarbonate resin of the present invention has an absolute value of orientation birefringence of 10.0 × 10 -3 It is preferable that it is less than 8.5 × 10 -3 It is more preferable that it is 5.5×10 or less. -3 It is even more preferable that it is less than 3.0 x 10 -3 It is more preferable that it is 1.5 × 10 or less. -3 It is even more preferable that it is 1.0×10 or less. -3 It is particularly preferable that it is 0.5 × 10 or less. -3 It is most preferable that the absolute value of orientation birefringence is less than the above range, since it is less likely to cause birefringence due to molecular orientation. Orientation birefringence is measured at a wavelength of 589 nm after cutting a test piece 70 mm long (45 mm between chucks) and 15 mm wide from a 100 μm thick cast film obtained from a polycarbonate resin and stretching it twice at Tg+10°C.

[0021] The polycarbonate resin of the present invention has a photoelastic coefficient of 40×10 -12 Pa or less, preferably 35×10 -12 Pa or less is more preferable, 30×10 -12 Pa or less is more preferable, and 25×10 -12It is more preferable that the photoelastic coefficient is 0.01 Pa or less. When the photoelastic coefficient is in the above range, birefringence due to stress is less likely to occur, which is preferable. The photoelastic coefficient is measured by cutting a test piece 50 mm long and 10 mm wide from a 100 μm thick cast film obtained from a polycarbonate resin, using a Spectroellipsometer M-220 manufactured by JASCO Corporation.

[0022] The polycarbonate resin of the present invention preferably has a refractive index nd measured at a temperature of 20°C and a wavelength of 587.56 nm of 1.550 or more, more preferably 1.575 or more, even more preferably 1.600 or more, even more preferably 1.610 or more, and particularly preferably 1.620 or more. A refractive index nd within the above range is preferred because it allows for the thinning of optical components. Furthermore, the refractive index nd may be 1.650 or less, 1.645 or less, 1.640 or less, or 1.635 or less. A refractive index nd within the above range is preferred because it increases the degree of freedom in optical design when combining and using multiple lenses.

[0023] The polycarbonate resin of the present invention preferably has an Abbe number of 23.0 or more, more preferably 25.0 or more, even more preferably 27.0 or more, even more preferably 30.0 or more, and even more preferably 32.0 or more. An Abbe number within the above range is preferable because it reduces chromatic aberration of optical components. The Abbe number may also be 35.0 or less, or 34.0 or less. An Abbe number within the above range is preferable because it increases the degree of freedom in optical design when combining and using multiple lenses.

[0024] Here, the Abbe number (νd) is calculated using the following formula from the refractive index at a temperature of 20° C. and wavelengths of 486.13 nm, 587.56 nm, and 656.27 nm. νd=(nd-1) / (nF-nC) nd: refractive index at a wavelength of 587.56 nm, nF: refractive index at a wavelength of 486.13 nm, nC: Refractive index at a wavelength of 656.27 nm.

[0025] The refractive index and Abbe number of the polycarbonate resin of the present invention preferably satisfy the following formula (A). nd≧-0.0063×νd+α (A) In formula (A), α is preferably 1.768 or more, more preferably 1.770 or more, even more preferably 1.772 or more, still more preferably 1.775 or more, and most preferably 1.777 or more. It is preferable that nd>1.535.

[0026] The refractive index and Abbe number of the polycarbonate resin of the present invention may satisfy the following mathematical formula (B). nd≦-0.0057×νd+β (B) In formula (B), β may be 1.782 or less, 1.780 or less, 1.778 or less, 1.776 or less, or 1.773 or less. When the refractive index and Abbe number are within the above ranges, the Abbe number relative to the refractive index is high, which is preferable since it broadens the scope of optical design.

[0027] The polycarbonate resin of the present invention preferably has a glass transition temperature of 140°C or higher, more preferably 142°C or higher, even more preferably 144°C or higher, even more preferably 146°C or higher, and even more preferably 148°C or higher. A glass transition temperature within the above range is preferred because it broadens the temperature range in which optical components can be used. The glass transition temperature may also be 160°C or lower, 157°C or lower, or 154°C or lower. A glass transition temperature within the above range is preferred because it provides an excellent balance between heat resistance and moldability.

[0028] The polycarbonate resin of the present invention preferably has a thermal decomposition temperature of 370°C or higher, more preferably 375°C or higher, and even more preferably 380°C or higher. Thermal decomposition temperatures above this level are preferred because the polycarbonate resin of the present invention exhibits excellent processing stability during molding and is less likely to be discolored. The thermal decomposition temperature may also be 420°C or lower, or 400°C or lower. The thermal decomposition temperature can be measured by TGA (thermogravimetric analysis) and is the temperature at which the weight decreases by 5%.

[0029] The specific viscosity of the polycarbonate resin of the present invention is preferably 0.12 to 0.32, and more preferably 0.18 to 0.30. When the specific viscosity is within the above range, an excellent balance between moldability and strength is achieved.

[0030] The specific viscosity is measured by dissolving 0.7 g of polycarbonate resin in 100 ml of methylene chloride, measuring the specific viscosity (ηSP) at 20° C. with an Ostwald viscometer, and calculating from the following formula. ηSP=(t-t0) / t0 [t0 is the number of seconds it takes for methylene chloride to fall, and t is the number of seconds it takes for the sample solution to fall]

[0031] The partial dispersion ratio (θgF) from the g line to the F line of the polycarbonate resin of the present invention is preferably 0.64 or less, more preferably 0.63 or less, even more preferably 0.62 or less, still more preferably 0.61 or less, and most preferably 0.59 or less. θgF of the above or less is preferable because it broadens the scope of optical design.

[0032] Here, the partial dispersion ratio (θgF) from the g-line to the F-line is calculated using the following formula from the refractive indexes at a temperature of 20° C. and wavelengths of 435.83 nm, 587.56 nm, and 656.27 nm. θgF=(ng-nF) / (nF-nC) ng: refractive index at wavelength 435.83 nm, nF: refractive index at a wavelength of 486.13 nm, nC: Refractive index at a wavelength of 656.27 nm.

[0033] In the polycarbonate resin of the present invention, R 1 ~R 4 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and examples of the hydrocarbon group include an alkyl group, a cycloalkyl group, and an aryl group.

[0034] Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, and a t-butyl group, with a methyl group and an ethyl group being preferred.

[0035] Examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a bicyclo[1.1.1]pentanyl group.

[0036] Examples of the aryl group include a phenyl group, a tolyl group, a naphthyl group, and a xylyl group, with a phenyl group being preferred.

[0037] R 1 ~R 4 are each independently preferably a hydrogen atom, a methyl group, or a phenyl group, more preferably a hydrogen atom or a phenyl group, and R 1 and R 2 are each independently a hydrogen atom or a phenyl group, and R 3 and R 4 is more preferably a hydrogen atom, since the volume of the aliphatic ring occupying the space increases and the photoelastic coefficient can be reduced.

[0038] In the above formula (4), n is in the range of 0 to 8, preferably 0 to 5 or 1 to 3, and particularly preferably 3, since the glass transition temperature is high.

[0039] Furthermore, R is selected from alkyl groups having 1 to 3 carbon atoms, and is preferably a methyl group or an ethyl group. In particular, a methyl group is preferred because it has a high glass transition temperature.

[0040] In particular, the repeating unit of the above formula (4) is preferably a repeating unit derived from 4,4'-(3,3,5-trimethylcyclohexylidene)bisphenol (known as bisphenol TMC), 4,4'-cyclohexylidenebisphenol (known as bisphenol Z), or 4,4'-(3-methylcyclohexylidene)bisphenol (known as bisphenol 3MZ), and among these, a repeating unit derived from bisphenol TMC is preferred because it can increase the glass transition temperature.

[0041] The repeating units represented by the above formula (1) and / or formula (2) are repeating units derived from pentacyclopentadecanedimethanol, and the repeating units represented by the above formula (1) and / or formula (2) may be pure substances or mixtures of isomers in any ratio. Pentacyclopentadecanedimethanol includes the following structural formulas:

[0042] [ka]

[0043] [ka]

[0044] The repeating unit represented by the above formula (3) is preferably a repeating unit derived from 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene or 9,9-bis[4-(2-hydroxyethoxy)-3-phenylphenyl]fluorene, and a repeating unit derived from 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene is preferred because it reduces orientation birefringence.

[0045] The polycarbonate resin of the present invention may contain repeating units other than those represented by the above formulas (1) to (4) as long as the advantageous effects of the present invention are obtained. Examples of dihydroxy compounds that result in such repeating units include ethylene glycol, propanediol, butanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, tricyclo[5.2.1.0]diol, and the like. 2,6 ]Decanedimethanol, cyclohexane-1,4-dimethanol, decalin-2,6-dimethanol, norbornane dimethanol, cyclopentane-1,3-dimethanol, isosorbide, isomannide, isoidide, hydroquinone, resorcinol, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, bis(4-hydroxyphenyl)diphenylmethane, 1,3-bis(2-(4-hydroxyphenyl) Examples of such repeating units include 4,4'-(4-hydroxyphenyl)-2-propyl)benzene, 4,4'-(3,3,5-trimethylcyclohexylidene)bisphenol, 4,4'-cyclohexylidenebisphenol, 4,4'-(3-methylcyclohexylidene)bisphenol, bis(4-hydroxyphenyl)sulfone, bis(4-hydroxyphenyl)sulfide, biphenol, bisphenolfluorene, biscresolfluorene, 1,1'-bi-2-naphthol, and 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthalene. The content of such repeating units may be 30 mol % or less of all repeating units.

[0046] In the polycarbonate resin of the present invention, the total amount of repeating units represented by the above formulas (1) to (4) is preferably 70 mol % or more, more preferably 80 mol % or more, and even more preferably 90 mol % or more, of all repeating units.

[0047] The total content of repeating units represented by formula (1) and / or formula (2) in all repeating units of the resin is greater than 0 mol%, and may be 2 mol% or more, 8 mol% or more, 12 mol% or more, 15 mol% or more, 20 mol% or more, 25 mol% or more, 30 mol% or more, 33 mol% or more, 37 mol% or more, 40 mol% or more, 45 mol% or more, or 50 mol% or less, 45 mol% or less, 38 mol% or less, 25 mol% or less, 16 mol% or less, or 10 mol% or less. The content of the repeating units is greater than 0 mol% and 50 mol% or less, and is preferably 2 mol% to 45 mol%, and more preferably 2 mol% to 40 mol% because the Abbe number is high, the photoelastic coefficient is low, and the balance between orientation birefringence, refractive index, and glass transition temperature is excellent.

[0048] The total amount of repeating units represented by formula (3) in all repeating units of the resin may be 10 mol% or more, 15 mol% or more, 20 mol% or more, 30 mol% or more, 35 mol% or more, 40 mol% or more, 45 mol% or more, 50 mol% or more, 60 mol% or more, 70 mol% or more, 80 mol% or more, 90 mol% or more, or 95 mol% or less, 80 mol% or less, 50 mol% or less, 45 mol% or less, 30 mol% or less, 20 mol% or less. The amount of repeating units is preferably 10 mol% to 95 mol%, more preferably 12 mol% to 94 mol%, and even more preferably 15 mol% to 93 mol% because orientation birefringence is low.

[0049] The repeating units represented by formula (4) in all repeating units of the resin may be more than 0 mol%, 2 mol% or more, 3 mol% or more, 5 mol% or more, 8 mol% or more, 10 mol% or more, 15 mol% or more, 20 mol% or more, 25 mol% or more, 30 mol% or more, 35 mol% or more, or may be 45 mol% or less, 40 mol% or less, 30 mol% or less, 25 mol% or less, 20 mol% or less. The repeating units are preferably more than 0 mol% to 45 mol% or less, more preferably 2 mol% to 43 mol%, and even more preferably 3 mol% to 40 mol% because the glass transition temperature is high.

[0050] The polycarbonate resin of the present invention preferably does not have a terminal phenolic hydroxyl group. That is, when a monomer that produces a repeating unit represented by the above formula (4) is polymerized and bonded to the terminal, the terminal group becomes a phenolic hydroxyl group. Therefore, it is preferable to reduce the amount of terminal phenolic hydroxyl groups in the polycarbonate resin by using, for example, an excess amount of a carbonate diester over the starting dihydroxy compound during polymerization to convert the terminal to a phenyl group.

[0051] The ratio of terminal phenolic hydroxyl groups can be determined as follows. Terminal phenolic hydroxyl group ratio = (amount of terminal phenolic hydroxyl groups / total amount of terminals) x 100 All of the terminals consist of a terminal phenolic hydroxyl group, a terminal alcoholic hydroxyl group, and a terminal phenyl group. Although not limited to this example, specifically, the terminal phenolic hydroxyl group ratio can be determined by the following method.

[0052] (1) The terminal phenolic hydroxyl group of the polycarbonate resin 1 Observe by H NMR measurement, take the integral of the relevant peak, and set this to 1. At the same time, calculate the integral intensity (A) of one proton of the fluorene structure from the integral intensity of the peaks at positions 4 and 5 of the fluorene structure derived from the above formula (3). If no peak of the terminal phenolic hydroxyl group is observed, the terminal phenolic hydroxyl group ratio is 0.

[0053] (2) The average degree of polymerization of the polycarbonate resin is calculated from the average molecular weight obtained by GPC measurement of the polycarbonate resin and the molecular weight and molar ratio of each repeating unit, and the terminal 1 The integrated intensity (B) in the H NMR spectrum is calculated using the following formula: (B) = (A) × 100 × 2 / ([mol% of the above formula (3)] × average degree of polymerization)

[0054] (3) The terminal phenolic hydroxyl group ratio is calculated as 1 / (B) × 100.

[0055] The ratio of terminal phenolic hydroxyl groups to all terminals of the polycarbonate resin of the present invention is preferably 30% or less, 20% or less, 15% or less, 10% or less, 5% or less, 3% or less, 1% or less, or 0.5% or less, which is preferable because it suppresses color change due to wet heat.

[0056] The polycarbonate resin of the present invention has a total light transmittance of preferably 80% or more, more preferably 85% or more, and particularly preferably 88% or more when molded into a 1 mm thick article. The 1 mm thick molded article can be obtained by subjecting the polycarbonate resin of the present invention to injection molding, hot press molding, melt extrusion molding, or the like.

[0057] The saturated water absorption of the polycarbonate resin of the present invention may be 0.10% to 0.70%, 0.20% to 0.70%, or 0.30% to 0.65%.

[0058] <Manufacturing method of polycarbonate resin> The polycarbonate resin of the present invention is produced by a reaction means known per se for producing ordinary polycarbonate resins, for example, a method of reacting a dihydroxy compound with a carbonate precursor such as a carbonic acid diester. The basic means for these production methods will now be briefly described.

[0059] The transesterification reaction using a carbonate diester as a carbonate precursor is carried out by stirring a predetermined ratio of dihydroxy component with a carbonate diester under heating in an inert gas atmosphere, and distilling off the resulting alcohol or phenol. The reaction temperature varies depending on the boiling point of the resulting alcohol or phenol, but is usually in the range of 120 to 300°C. The reaction is completed by reducing the pressure from the beginning of the reaction to distill off the resulting alcohol or phenol. If necessary, a terminal capping agent, antioxidant, etc. may also be added.

[0060] The carbonic acid diester used in the transesterification reaction includes esters of an aryl group or an aralkyl group having 6 to 12 carbon atoms, which may be substituted. Specific examples include diphenyl carbonate, ditolyl carbonate, bis(chlorophenyl)carbonate, and m-cresyl carbonate. Of these, diphenyl carbonate is particularly preferred. The amount of diphenyl carbonate used is preferably 0.95 to 1.10 mol, more preferably 0.98 to 1.04 mol, per mol of the total amount of dihydroxy compounds.

[0061] In the melt polymerization method, a polymerization catalyst can be used to increase the polymerization rate. Examples of such a polymerization catalyst include alkali metal compounds, alkaline earth metal compounds, and nitrogen-containing compounds.

[0062] As such compounds, organic acid salts, inorganic salts, oxides, hydroxides, hydrides, alkoxides, quaternary ammonium hydroxides, etc. of alkali metals or alkaline earth metals are preferably used, and these compounds can be used alone or in combination.

[0063] Examples of alkali metal compounds include sodium hydroxide, potassium hydroxide, cesium hydroxide, lithium hydroxide, sodium bicarbonate, 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 benzoate, potassium benzoate, cesium benzoate, lithium benzoate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, dilithium hydrogen phosphate, disodium phenylphosphate, disodium salt, dipotassium salt, dicesium salt, dilithium salt of bisphenol A, sodium salt, potassium salt, cesium salt, and lithium salt of phenol.

[0064] Examples of alkaline earth metal compounds include magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, magnesium carbonate, calcium carbonate, strontium carbonate, barium carbonate, magnesium diacetate, calcium diacetate, strontium diacetate, and barium diacetate.

[0065] Examples of the nitrogen-containing compound include quaternary ammonium hydroxides having an alkyl or aryl group, such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and trimethylbenzylammonium hydroxide. Examples of the nitrogen-containing compound include bases or basic salts, such as tetramethylammonium borohydride, tetrabutylammonium borohydride, tetrabutylammonium tetraphenylborate, and tetraphenylammonium tetraphenylborate.

[0066] Other transesterification catalysts include salts of zinc, tin, zirconium, lead, titanium, germanium, antimony, and osmium, such as zinc acetate, zinc benzoate, zinc 2-ethylhexanoate, tin chloride (II), tin chloride (IV), tin acetate (II), tin acetate (IV), dibutyltin dilaurate, dibutyltin oxide, dibutyltin dimethoxide, zirconium acetylacetonate, zirconium oxyacetate, zirconium tetrabutoxide, lead acetate (II), lead acetate (IV) titanium tetrabutoxide (IV), etc. The catalysts used in WO 2011 / 010741 and JP 2017-179323 A may also be used.

[0067] Furthermore, a catalyst comprising aluminum or a compound thereof and a phosphorus compound may be used, in which case the amount is preferably 80 μmol to 1000 μmol, more preferably 90 μmol to 800 μmol, and even more preferably 100 μmol to 600 μmol per 1 mol of the dihydroxy component.

[0068] Examples of aluminum salts include organic and inorganic aluminum salts. Examples of organic aluminum salts include aluminum carboxylates, specifically aluminum formate, aluminum acetate, aluminum propionate, aluminum oxalate, aluminum acrylate, aluminum laurate, aluminum stearate, aluminum benzoate, aluminum trichloroacetate, aluminum lactate, aluminum citrate, and aluminum salicylate. Examples of inorganic aluminum salts include aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride, aluminum carbonate, aluminum phosphate, and aluminum phosphonate. Examples of aluminum chelate compounds include aluminum acetylacetonate, aluminum acetylacetate, aluminum ethylacetoacetate, and aluminum ethylacetoacetate diisopropoxide.

[0069] Examples of phosphorus compounds include phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phosphonous acid compounds, phosphinous acid compounds, and phosphine compounds. Among these, phosphonic acid compounds, phosphinic acid compounds, and phosphine oxide compounds are particularly preferred, and phosphonic acid compounds are particularly preferred.

[0070] The amount of these polymerization catalysts used is preferably 0.1 μmol to 500 μmol, more preferably 0.5 μmol to 300 μmol, and even more preferably 1 μmol to 100 μmol, per 1 mol of the dihydroxy component.

[0071] A catalyst deactivator can also be added in the latter stage of the reaction. Known catalyst deactivators are effectively used as the catalyst deactivator, but among these, ammonium salts and phosphonium salts of sulfonic acid are preferred. Salts of dodecylbenzenesulfonic acid, such as tetrabutylphosphonium dodecylbenzenesulfonate, and salts of paratoluenesulfonic acid, such as tetrabutylammonium paratoluenesulfonate, are more preferred.

[0072] Preferred examples of sulfonic acid esters include methyl benzenesulfonate, ethyl benzenesulfonate, butyl benzenesulfonate, octyl benzenesulfonate, phenyl benzenesulfonate, methyl paratoluenesulfonate, ethyl paratoluenesulfonate, butyl paratoluenesulfonate, octyl paratoluenesulfonate, and phenyl paratoluenesulfonate. Of these, tetrabutylphosphonium dodecylbenzenesulfonate is most preferably used.

[0073] When at least one polymerization catalyst selected from alkali metal compounds and / or alkaline earth metal compounds is used, the amount of these catalyst deactivators used is preferably 0.5 to 50 mol, more preferably 0.5 to 10 mol, and even more preferably 0.8 to 5 mol, per mol of the catalyst.

[0074] <Optional additives> The polycarbonate resin of the present invention can be used as a resin composition by appropriately adding additives such as a mold release agent, a heat stabilizer (sometimes also referred to as an antioxidant), an ultraviolet absorber, a bluing agent, an antistatic agent, a flame retardant, a plasticizer, a filler, an antioxidant, a light stabilizer, a polymerized metal deactivator, a lubricant, a surfactant, and an antibacterial agent, as needed. Specific examples of mold release agents and heat stabilizers include those described in WO 2011 / 010741.

[0075] Particularly preferred release agents include stearic acid monoglyceride, stearic acid triglyceride, pentaerythritol tetrastearate, and a mixture of stearic acid triglyceride and stearyl stearate. The amount of the ester in the release agent is preferably 90% by weight or more, more preferably 95% by weight or more, based on 100% by weight of the release agent. The content of the release agent is preferably in the range of 0.005 to 2.0 parts by weight, more preferably 0.01 to 0.6 parts by weight, and even more preferably 0.02 to 0.5 parts by weight, based on 100 parts by weight of the polycarbonate resin.

[0076] Examples of the heat stabilizer include phosphorus-based heat stabilizers, sulfur-based heat stabilizers, and hindered phenol-based heat stabilizers.

[0077] Particularly preferred phosphorus-based heat stabilizers include tris(2,4-di-tert-butylphenyl)phosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene diphosphonite, distearylpentaerythritol diphosphite, bis(2,4-dicumylphenyl)pentaerythritol diphosphite, cyclic neopentanetetraylbis(2,6-di-tert-butyl-4-methylphenyl phosphite), and bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite. The content of the phosphorus-based heat stabilizer is preferably 0.001 to 0.2 parts by weight per 100 parts by weight of the polycarbonate resin.

[0078] A particularly preferred sulfur-based heat stabilizer is pentaerythritol-tetrakis(3-laurylthiopropionate).The content of the sulfur-based heat stabilizer is preferably 0.001 to 0.2 parts by weight based on 100 parts by weight of the polycarbonate resin.

[0079] Further, preferred hindered phenol-based heat stabilizers include octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, pentaerythritol-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,3,5-trimethyl-2,4,6-tris(3 ,5-di-tert-butyl-4-hydroxybenzyl)benzene, N,N-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy-hydrocinnamide), 3,5-di-tert-butyl-4-hydroxy-benzylphosphonate-diethyl ester, tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, 3,9-bis{1,1-dimethyl-2-[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl}-2,4,8,10-tetraoxaspiro(5,5)undecane.

[0080] The content of the hindered phenol-based heat stabilizer is preferably 0.001 to 0.3 parts by weight relative to 100 parts by weight of the polycarbonate resin.

[0081] The phosphorus-based heat stabilizer and the hindered phenol-based heat stabilizer can also be used in combination.

[0082] The ultraviolet absorber is preferably at least one ultraviolet absorber selected from the group consisting of benzotriazole-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, triazine-based ultraviolet absorbers, cyclic iminoester-based ultraviolet absorbers, and cyanoacrylate-based ultraviolet absorbers.

[0083] Of the benzotriazole-based ultraviolet absorbers, 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole and 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol] are more preferred.

[0084] Benzophenone-based ultraviolet absorbers include 2-hydroxy-4-n-dodecyloxybenzophenone and 2-hydroxy-4-methoxy-2'-carboxybenzophenone.

[0085] Examples of triazine-based ultraviolet absorbers include 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]-phenol and 2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl)-5-[(octyl)oxy]-phenol.

[0086] As the cyclic iminoester-based ultraviolet absorber, 2,2'-p-phenylenebis(3,1-benzoxazin-4-one) is particularly suitable.

[0087] Examples of cyanoacrylate ultraviolet absorbers include 1,3-bis-[(2'-cyano-3',3'-diphenylacryloyl)oxy]-2,2-bis[(2-cyano-3,3-diphenylacryloyl)oxy]methyl)propane and 1,3-bis-[(2-cyano-3,3-diphenylacryloyl)oxy]benzene.

[0088] The amount of ultraviolet absorber to be blended is preferably 0.01 to 3.0 parts by weight per 100 parts by weight of polycarbonate resin, and within this blending range, it is possible to impart sufficient weather resistance to molded articles of polycarbonate resin depending on the application.

[0089] <Optical components> The optical member of the present invention contains the polycarbonate resin described above. Such optical members are not particularly limited as long as they are used for optical applications in which the polycarbonate resin is useful, and examples of such optical members include optical disks, transparent conductive substrates, optical cards, sheets, films, optical fibers, lenses, prisms, optical films, substrates, optical filters, and hard coat films.

[0090] The optical member of the present invention may be composed of a resin composition containing the above-mentioned polycarbonate resin, and the resin composition may contain additives such as a heat stabilizer, a plasticizer, a light stabilizer, a polymerized metal deactivator, a flame retardant, a lubricant, an antistatic agent, a surfactant, an antibacterial agent, an ultraviolet absorber, a release agent, a bluing agent, a filler, and an antioxidant, as needed.

[0091] <Optical lenses> The optical member of the present invention can be particularly an optical lens. Examples of such an optical lens include imaging lenses for mobile phones, smartphones, tablet terminals, personal computers, digital cameras, video cameras, vehicle-mounted cameras, surveillance cameras, etc., and sensing cameras such as TOF cameras. The optical member of the present invention is particularly useful as an imaging lens.

[0092] When the optical lens of the present invention is produced by injection molding, molding is preferably carried out under conditions of a cylinder temperature of 220 to 350°C and a mold temperature of 70 to 180°C. More preferably, molding is carried out under conditions of a cylinder temperature of 240 to 300°C and a mold temperature of 80 to 170°C. If the cylinder temperature is higher than 350°C, the polycarbonate resin will decompose and discolor, and if it is lower than 230°C, the melt viscosity will be high, making molding difficult. Furthermore, if the mold temperature is higher than 180°C, it will be difficult to remove a molded piece made of polycarbonate resin from the mold. On the other hand, if the mold temperature is lower than 70°C, the resin will harden too quickly in the mold during molding, making it difficult to control the shape of the molded piece and making it difficult to sufficiently transfer the shape imprinted on the mold.

[0093] The optical lens of the present invention is preferably implemented as an aspherical lens, if necessary. Since a single aspherical lens can substantially eliminate spherical aberration, it is not necessary to combine multiple spherical lenses to eliminate spherical aberration, which allows for weight reduction and reduced molding costs. Therefore, aspherical lenses are particularly useful as camera lenses, among other optical lenses.

[0094] Furthermore, the polycarbonate resin of the present invention has high molding fluidity and is therefore particularly useful as a material for optical lenses that are thin, small, and have complex shapes. Specific lens sizes include a central thickness of 0.05 to 3.0 mm, more preferably 0.05 to 2.0 mm, and even more preferably 0.1 to 2.0 mm. Furthermore, the diameter is 1.0 mm to 20.0 mm, more preferably 1.0 to 10.0 mm, and even more preferably 3.0 to 10.0 mm. Furthermore, the lens preferably has a meniscus shape, with one side convex and the other concave.

[0095] The lens made of the polycarbonate resin of the present invention can be formed by any method such as mold molding, cutting, polishing, laser processing, electrical discharge processing, etching, etc. Among these, mold molding is more preferred in terms of production costs.

[0096] The present invention will be explained in more detail in the following examples, but the present invention is not limited thereto. [Example]

[0097] The evaluation was carried out by the following method. <Polycarbonate resin composition> JEOL JNM-ECZ400S 1 The copolymerization ratio of each polycarbonate resin was calculated by measuring 1 H NMR.

[0098] <Weight average molecular weight (Mw) The weight average molecular weight Mw was measured using EcoSEC HLC-8320GPC manufactured by TOSOH under the conditions described below. Detector: UV-8420, Solvent: Chloroform, Column: TOSOH TSKgel SupermultiporeHZM-M × 3 + TSKgel guard column (4.6 × 200 nm), Measurement temperature: 40°C, Flow rate: 0.35 ml / min, Injection volume: 5 μl, Sample concentration: 1 mg / 5 ml, Standard sample: TSKstandard Polystyrene

[0099] <Refractive index> A 3 mm thick test piece of each polycarbonate resin was prepared and polished, and then the refractive index nd (587.56 nm) was measured using a Kalnew Precision Refractometer KPR-2000 manufactured by Shimadzu Corporation.

[0100] <Abbe number> The Abbe number (νd) was calculated using the following formula from the refractive index at a temperature of 20° C. and wavelengths of 486.13 nm, 587.56 nm, and 656.27 nm. νd=(nd-1) / (nF-nC) nd: refractive index at a wavelength of 587.56 nm, nF: refractive index at a wavelength of 486.13 nm, nC: Refractive index at a wavelength of 656.27 nm.

[0101] <Absolute value of orientation birefringence> Polycarbonate resin was dissolved in methylene chloride, cast onto a glass dish, and thoroughly dried to prepare a 100 μm thick cast film. Test pieces 70 mm long (45 mm between chucks) and 15 mm wide were cut out from the film and stretched twice at Tg+10°C. The retardation (Re) at 589 nm was measured using a JASCO M-220 ellipsometer, and the absolute value of orientation birefringence (|Δn|) was calculated using the following formula: |Δn|=|Re / d| Δn: Orientation birefringence Re: Phase difference (nm) d: thickness (nm)

[0102] <Photoelastic coefficient> Polycarbonate resin was dissolved in methylene chloride, cast onto a glass dish, and thoroughly dried to prepare a 100 μm thick cast film. Test pieces measuring 50 mm in length and 10 mm in width were cut out from the film, and the photoelastic coefficient was measured using an Ellipsometer M-220 manufactured by JASCO Corporation.

[0103] <Glass transition temperature (Tg)> The obtained polycarbonate resin was measured at a heating rate of 20°C / min using a Discovery DSC 25Auto model manufactured by TA Instruments Japan Co., Ltd. The sample was measured in an amount of 5 to 10 mg.

[0104] <Thermal decomposition temperature (Td-5)> The resulting polycarbonate resin was measured using a TA Instruments Japan SDT650 at a heating rate of 20°C / min, and the temperature at which the weight decreased by 5% was determined based on the weight at 50°C. 3-4 mg of the sample was used for the measurement.

[0105] <θgF> The partial dispersion ratio (θgF) from the g-line to the F-line is calculated using the following formula from the refractive indexes at a temperature of 20°C and wavelengths of 435.83 nm, 587.56 nm, and 656.27 nm. θgF=(ng-nF) / (nF-nC) ng: refractive index at wavelength 435.83 nm, nF: refractive index at a wavelength of 486.13 nm, nC: Refractive index at a wavelength of 656.27 nm.

[0106] <Ratio of terminal phenolic hydroxyl groups> The ratio of terminal phenolic hydroxyl groups can be determined as follows. Terminal phenolic hydroxyl group ratio = (amount of terminal phenolic hydroxyl groups / total amount of terminals) x 100 Specifically, the terminal phenolic hydroxyl group ratio can be determined by the following method.

[0107] (1) The terminal phenolic hydroxyl group of the polycarbonate resin1 Observe by H NMR measurement, take the integral of the relevant peak, and set this to 1. At the same time, calculate the integral intensity (A) of one proton of the fluorene structure from the integral intensity of the peaks at positions 4 and 5 of the fluorene structure derived from the above formula (3). If no peak of the terminal phenolic hydroxyl group is observed, the terminal phenolic hydroxyl group ratio is 0.

[0108] (2) The average degree of polymerization of the polycarbonate resin is calculated from the average molecular weight obtained by GPC measurement of the polycarbonate resin and the molecular weight and molar ratio of each repeating unit, and the terminal 1 The integrated intensity (B) in the H NMR spectrum is calculated using the following formula: (B) = (A) × 100 × 2 / ([mol% of the above formula (3)] × average degree of polymerization)

[0109] (3) The terminal phenolic hydroxyl group ratio is calculated as 1 / (B) × 100.

[0110] Example 1 83.32 g (0.19 mol) of 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene (hereinafter sometimes abbreviated as BPEF), 49.85 g (0.19 mol) of pentacyclopentadecanedimethanol (hereinafter sometimes abbreviated as PCPDM), 6.20 g (0.02 mol) of 4,4'-(3,3,5-trimethylcyclohexylidene)bisphenol (hereinafter sometimes abbreviated as BisTMC), 89.12 g (0.42 mol) of diphenyl carbonate, and 17 μL of a 60 mmol / L aqueous solution of sodium bicarbonate (1 μmol of sodium bicarbonate) and 22 μL of a 274 mmol / L aqueous solution of tetramethylammonium hydroxide (6 μmol of tetramethylammonium hydroxide) were heated to 180 °C under a nitrogen atmosphere and melted. The reactor was then heated to 250°C at a rate of 60°C / hr while the pressure inside the reactor was reduced to 20 kPa over 40 minutes. After 70% of the theoretical amount of phenol had been distilled off, the reactor pressure was reduced to 133 Pa or less over 1 hour. The reactor was then stirred at 260°C for 40 minutes with the reactor pressure at 133 Pa or less to terminate the reaction, and the resin was taken out. The copolymerization ratio of BPEF, PCPDM, and BisTMC in the resulting polycarbonate resin was: 1 The polycarbonate resin was measured by H NMR. The weight average molecular weight Mw, refractive index, Abbe number, θgF, glass transition temperature, thermal decomposition temperature, absolute value of orientation birefringence, and photoelastic coefficient were evaluated. The terminal phenolic hydroxyl group ratio of the polycarbonate resin was 0%.

[0111] <Example 2> A polycarbonate resin was produced in the same manner as in Example 1, except that the amount of BPEF charged was 135.06 g (0.31 mol) and the amount of PCPDM charged was 18.89 g (0.07 mol). The copolymerization ratio of BPEF, PCPDM, and BisTMC in the obtained polycarbonate resin was 1 The polycarbonate resin was measured by H NMR. The weight average molecular weight Mw, refractive index, Abbe number, θgF, glass transition temperature, thermal decomposition temperature, absolute value of orientation birefringence, and photoelastic coefficient were evaluated. The terminal phenolic hydroxyl group ratio of the polycarbonate resin was 0%.

[0112] Example 3 A polycarbonate resin was produced in the same manner as in Example 1, except that the amount of BPEF charged was 163.13 g (0.37 mol) and the amount of PCPDM charged was 2.10 g (0.01 mol). The copolymerization ratio of BPEF, PCPDM, and BisTMC in the obtained polycarbonate resin was 1 The polycarbonate resin was measured by H NMR. The weight average molecular weight Mw, refractive index, Abbe number, θgF, glass transition temperature, thermal decomposition temperature, absolute value of orientation birefringence, and photoelastic coefficient were evaluated. The terminal phenolic hydroxyl group ratio of the polycarbonate resin was 0%.

[0113] Example 4 A polycarbonate resin was produced in the same manner as in Example 1, except that the amount of BPEF charged was 70.16 g (0.16 mol), the amount of PCPDM charged was 47.23 g (0.18 mol), and the amount of BisTMC charged was 18.60 g (0.06 mol). The copolymerization ratio of BPEF, PCPDM, and BisTMC in the obtained polycarbonate resin was 1 The polycarbonate resin was measured by H NMR. The weight average molecular weight Mw, refractive index, Abbe number, θgF, glass transition temperature, thermal decomposition temperature, absolute value of orientation birefringence, and photoelastic coefficient were evaluated. The terminal phenolic hydroxyl group ratio of the polycarbonate resin was 0%.

[0114] <Example 5> A polycarbonate resin was produced in the same manner as in Example 1, except that the amount of BPEF charged was 26.31 g (0.06 mol), the amount of PCPDM charged was 47.23 g (0.18 mol), and the amount of BisTMC charged was 49.60 g (0.16 mol). The copolymerization ratio of BPEF, PCPDM, and BisTMC in the obtained polycarbonate resin was 1 The polycarbonate resin was measured by H NMR. The weight average molecular weight Mw, refractive index, Abbe number, θgF, glass transition temperature, thermal decomposition temperature, absolute value of orientation birefringence, and photoelastic coefficient were evaluated. The terminal phenolic hydroxyl group ratio of the polycarbonate resin was 0%.

[0115] Example 6 A polycarbonate resin was produced in the same manner as in Example 1, except that the amount of BPEF charged was 87.70 g (0.20 mol), the amount of PCPDM charged was 26.24 g (0.10 mol), and the amount of BisTMC charged was 31.00 g (0.10 mol). The copolymerization ratio of BPEF, PCPDM, and BisTMC in the obtained polycarbonate resin was 1 The polycarbonate resin was measured by H NMR. The weight average molecular weight Mw, refractive index, Abbe number, θgF, glass transition temperature, thermal decomposition temperature, absolute value of orientation birefringence, and photoelastic coefficient were evaluated. The terminal phenolic hydroxyl group ratio of the polycarbonate resin was 0%.

[0116] <Comparative Example 1> 45.66 g (0.20 mol) of bisphenol A (hereinafter sometimes abbreviated as BPA), 52.48 g (0.20 mol) of PCPDM, 86.97 g (0.406 mol) of diphenyl carbonate, and 1.09 mg (12 μmol) of sodium bicarbonate as a catalyst were heated to 180 ° C under a nitrogen atmosphere and melted. Then, the pressure inside the reactor was set to 20 kPa (150 mmHg) and the temperature was raised to 200 ° C at a rate of 60 ° C / hr, and the reaction was carried out while maintaining that temperature for 40 minutes. Further, the temperature was raised to 225 ° C at a rate of 75 ° C / hr, and 40 minutes after the temperature increase, the pressure inside the reactor was maintained at that temperature for 1 hour while reducing it to 133 Pa (1 mmHg) or less. The temperature was then raised to 235°C at a rate of 105°C / hr, and the reaction was carried out for a total of 6 hours under stirring. After the reaction was completed, nitrogen was blown into the reactor to return it to normal pressure, and the resulting resin was taken out. The copolymerization ratio of BPA and PCPDM in the resulting polycarbonate resin was 1 The weight average molecular weight Mw, refractive index, Abbe number, glass transition temperature, thermal decomposition temperature, absolute value of orientation birefringence, and photoelastic coefficient of the polycarbonate resin were measured by H NMR.

[0117] <Comparative Example 2> A polycarbonate resin was produced in the same manner as in Comparative Example 1, except that the amount of BPA charged was 63.92 g (0.28 mol) and the amount of PCPDM charged was 31.49 g (0.12 mol). The copolymerization ratio of BPA and PCPDM in the obtained polycarbonate resin was 1 The weight average molecular weight Mw, refractive index, Abbe number, θgF, glass transition temperature, thermal decomposition temperature, absolute value of orientation birefringence, and photoelastic coefficient of the polycarbonate resin were measured by H NMR.

[0118] <Comparative Example 3> 42.10 g (0.10 mol) of BPEF, 57.22 g (0.19 mol) of SPG, 35.96 g (0.12 mol) of BisTMC, 89.12 g (0.42 mol) of diphenyl carbonate, and 33 μL of a 60 mmol / L aqueous sodium bicarbonate solution (2 μmol of sodium bicarbonate) as a catalyst were heated to 180 °C under a nitrogen atmosphere and melted. The pressure was then reduced to 20 kPa over 10 minutes. The temperature was raised to 250 °C at a rate of 60 °C / hr, and after the phenol outflow rate reached 70%, the pressure inside the reactor was reduced to 133 Pa or less over 1 hour. The reaction was carried out with stirring for a total of 3.5 hours, and the resin was removed from the flask after the reaction was completed. The copolymerization ratio of BPEF, SPG, and BisTMC in the resulting polycarbonate resin was calculated as follows: 1 The weight average molecular weight Mw, refractive index, Abbe number, θgF, glass transition temperature, thermal decomposition temperature, absolute value of orientation birefringence, and photoelastic coefficient of the polycarbonate resin were measured by H NMR.

[0119] <Comparative Example 4> A polycarbonate resin was produced in the same manner as in Comparative Example 3, except that 103.49 g (0.24 mol) of BPEF, 37.74 g (0.12 mol) of SPG, and 12.40 g (0.04 mol) of BisTMC were used. The copolymerization ratio of BPEF, SPG, and BisTMC in the obtained polycarbonate resin was: 1 The weight average molecular weight Mw, refractive index, Abbe number, θgF, glass transition temperature, thermal decomposition temperature, absolute value of orientation birefringence, and photoelastic coefficient of the polycarbonate resin were measured by H NMR.

[0120] <Comparative Example 5> A polycarbonate resin was produced in the same manner as in Comparative Example 3, except that 26.31 g (0.06 mol) of BPEF, 54.79 g (0.18 mol) of SPG, and 49.60 g (0.16 mol) of BisTMC were used. The copolymerization ratio of BPEF, SPG, and BisTMC in the obtained polycarbonate resin was: 1 The weight average molecular weight Mw, refractive index, Abbe number, θgF, glass transition temperature, thermal decomposition temperature, absolute value of orientation birefringence, and photoelastic coefficient of the polycarbonate resin were measured by H NMR.

[0121] <Comparative Example 6> A polycarbonate resin was produced in the same manner as in Comparative Example 3, except that 87.70 g (0.20 mol) of BPEF, 30.44 g (0.10 mol) of SPG, and 31.00 g (0.10 mol) of BisTMC were used. The copolymerization ratio of BPEF, SPG, and BisTMC in the obtained polycarbonate resin was 1 The weight average molecular weight Mw, refractive index, Abbe number, θgF, glass transition temperature, thermal decomposition temperature, absolute value of orientation birefringence, and photoelastic coefficient of the polycarbonate resin were measured by H NMR.

[0122] [Table 1]

[0123] Examples 1 to 6 of the present invention are superior in orientation birefringence and photoelastic coefficient compared to Comparative Examples 1 and 2, which correspond to the examples of Patent Document 1. Therefore, birefringence due to molecular orientation or stress is unlikely to occur when obtaining optical components by injection molding, etc. Furthermore, the refractive index and glass transition temperature are high, making them preferable as optical components.

[0124] Examples 2 and 3 of the present invention are preferable because they have superior orientation birefringence compared to Comparative Examples 3 to 6, which correspond to the examples of Patent Documents 3 and 4. They are also preferable because they have high glass transition temperatures and excellent heat resistance.

[0125] Example 4 of the present invention has a higher Abbe number than Comparative Example 4, which corresponds to the example of Patent Document 4, and can therefore broaden the scope of optical design, while having the same refractive index. Example 4 is also preferable because it has a higher glass transition temperature and excellent heat resistance.

[0126] In comparison with Comparative Examples 5 and 6, which correspond to the examples in Patent Documents 3 and 4, Examples 5 and 6 of the present invention have the same copolymerization ratio but replace SPG with PCPDM, thereby achieving a higher refractive index and thinner optical lenses while maintaining the same Abbe number. Furthermore, they are preferable because they have a higher glass transition temperature and excellent heat resistance.

[0127] As shown in Figure 1, when the refractive index and Abbe number are plotted, the comparative example has an Abbe number of 27.6 at a high refractive index, while the polycarbonate resin of the present invention has an Abbe number of 30.6 at the same refractive index, which is higher than the range of the prior art. Therefore, the chromatic aberration of the optical element can be reduced. [Industrial Applicability]

[0128] The polycarbonate resin of the present invention is used in optical materials, and can be used for optical members such as lenses, prisms, optical disks, transparent conductive substrates, optical cards, sheets, films, optical fibers, optical films, optical filters, and hard coat films, and is particularly useful for imaging lenses.

Claims

1. A polycarbonate resin comprising a repeating unit represented by formula (1) and / or formula (2), a repeating unit represented by formula (3), and a repeating unit represented by formula (4), wherein the total amount of repeating units represented by formula (1) and / or formula (2) in all repeating units of the resin is more than 0% and less than 50 mol%, and the polycarbonate resin has a weight average molecular weight Mw of 10,000 or more. 【Chemical 1】 【Chemistry 2】 【Chemistry 3】 (In the formula, R １ ~R ４ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. 【Chemistry 4】 (In formula (4), n is a number ranging from 0 to 8, and each R represents an alkyl group having 1 to 3 carbon atoms.)

2. 2. The polycarbonate resin according to claim 1, having a weight average molecular weight Mw of 10,000 or more and 60,000 or less.

3. 3. The polycarbonate resin according to claim 1, wherein the repeating unit represented by formula (3) accounts for 10 mol % to 95 mol % of all repeating units of the resin.

4. 3. The polycarbonate resin according to claim 1, wherein the repeating unit of formula (4) accounts for more than 0 mol % and not more than 45 mol % of all repeating units of the resin.

5. R in the formula (3) １ ~R ４ The polycarbonate resin according to claim 1 or 2, wherein is a hydrogen atom.

6. 3. The polycarbonate resin according to claim 1, wherein the repeating unit of formula (4) is a repeating unit derived from bisphenol TMC.

7. The absolute value of orientation birefringence is 10.0 × 10 －３ 3. The polycarbonate resin according to claim 1, wherein:

8. Photoelastic coefficient is 40 x 10 －１２ The polycarbonate resin according to claim 1 or 2, wherein the viscosity is 100 Pa or less.

9. 3. The polycarbonate resin according to claim 1, which has a refractive index nd of 1.550 or more.

10. 3. The polycarbonate resin according to claim 1, which has a glass transition temperature of 140°C or higher.

11. An optical member made of the polycarbonate resin according to claim 1 or 2.

12. The optical element according to claim 11 , wherein the optical element is an imaging lens.

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