Polycarbonate resin and optical member using same

Abstract

Provided is a polycarbonate resin containing repeating units 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 sum of the repeating units represented by formula (1) and / or formula (2) constitutes at least 50 mol% of all repeating units in the resin, and the weight average molecular weight Mw of the polycarbonate resin is at least 10,000, or the sum of the repeating units represented by formula (1) and / or formula (2) constitutes more than 0 mol% and less than 50 mol% of all repeating units in the resin, and the weight average molecular weight Mw of the polycarbonate resin is at least 10,000.　(In the formulas, R1 to R4 each independently represent a hydrogen atom or a C1-10 hydrocarbon group.)　(In formula (4), n is in the range of 0-8, and each R independently represents a C1-3 alkyl group.)

Description

Polycarbonate resin and optical member using said resin

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

[0002] Glass, which has traditionally been used as a material for optical systems, is capable of achieving various required optical properties and has excellent environmental resistance, but has the problem of poor processability. In response to this problem, resins, which are cheaper than glass materials and have excellent processability, have come to be used for optical components.

[0003] In the optical design of optical units, it is known to correct chromatic aberration by combining multiple lenses with different Abbe numbers. For example, chromatic aberration is corrected by combining a lens made of an alicyclic polyolefin resin, which has a low refractive index and a high Abbe number, with a lens made of a polycarbonate resin (nd = 1.59, vd = 31) made from bisphenol A, which has a high refractive index and a low Abbe number. In recent years, there has been active development of resins with high refractive indexes and low Abbe numbers, and as a result, demand for resins with high Abbe numbers has also increased. For example, Patent Document 1 describes a polycarbonate resin that has a high Abbe number but a low photoelastic coefficient, which is obtained by copolymerizing 2,2-bis(4-hydroxyphenyl)propane (commonly known as bisphenol A) and 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 that has a high refractive index and 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).

[0004] Furthermore, polycarbonate resins derived from bisphenol A, obtained by reacting bisphenol A with phosgene or a carbonate ester, 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 and PCPDM. Furthermore, Patent Document 2 proposes a method for producing a carbonate derivative without using a base, by photoreacting halogenated methane and a specific amount of a hydroxyl group-containing compound in the presence of oxygen. One example of the production method is a copolymerized polycarbonate of BPEF and PCPDM. Patent Documents 3 and 4 describe polycarbonate resins with small orientation birefringence obtained by copolymerizing BPEF, SPG, and BisTMC.

[0005] JP 2000-302860 A, WO 2020 / 100977 B, WO 2019 / 188702 B, WO 2022 / 004239 B

[0006] However, the polycarbonate resin made from the above-mentioned bisphenol A and PCPDM has the problem that its photoelastic coefficient leaves room for improvement, and also has a large orientation birefringence. Furthermore, the molecular weight of the resulting resin is high, making it unsuitable for injection molding applications and unable to be used for thin optical components such as imaging lenses. Furthermore, the above-mentioned copolymer polycarbonate of BPEF and PCPDM has an extremely low weight-average molecular weight of 3,360, making it insufficient for use as a structural or optical material. Furthermore, the polycarbonate resin made from BPEF, SPG, and BisTMC has the problem of a low Abbe number relative to its refractive index, and there is also room for improvement in its photoelastic coefficient.

[0007] The first aspect of the present disclosure has been made under the above circumstances, and an object of the first aspect is to provide a polycarbonate resin that has an excellent balance between the refractive index and the Abbe number, and further has small orientation birefringence and a small photoelastic coefficient.

[0008] Furthermore, the polycarbonate resin made from the above-mentioned bisphenol A and PCPDM had problems such as high orientation birefringence, as well as low refractive index and glass transition temperature. Furthermore, the molecular weight of the resulting resin was high, making it unsuitable for injection molding applications and unable to be used for thin optical components such as imaging lenses. Furthermore, the above-mentioned copolymer polycarbonate of BPEF and PCPDM had an extremely low weight-average molecular weight of 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 refractive index and glass transition temperature.

[0009] The second aspect of the present disclosure has been made under the above circumstances, and an object of the second aspect is to provide a polycarbonate resin having small orientation birefringence, a high refractive index, and a high glass transition temperature.

[0010] The present inventors have found that the above problems can be solved by the following aspects.

[0011] The first aspect of the present disclosure includes the following aspects.

[0012] <1> 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), wherein the total amount of repeating units represented by formula (1) and / or formula (2) in all repeating units of the resin is 50 mol % or more, and the polycarbonate resin has a weight average molecular weight Mw of 10,000 or more.

[0013]

[0014]

[0015]

[0016] (In the formula, R １ ~R ４each independently represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms.

[0017] (In formula (4), n is a number ranging from 0 to 8, and each R independently represents an alkyl group having 1 to 3 carbon atoms.)

[0018] <2> The polycarbonate resin according to <1>, having a weight average molecular weight Mw of 10,000 or more and 60,000 or less.

[0019] <3> The polycarbonate resin according to <1> or <2>, wherein the repeating unit represented by the formula (3) accounts for more than 0 mol % and not more than 50 mol % of all repeating units of the resin.

[0020] <4> The polycarbonate resin according to any one of <1> to <3>, wherein the repeating unit of the formula (4) accounts for more than 0 mol % and not more than 40 mol % of all repeating units of the resin.

[0021] <5> R in the formula (3) １ ~R ４ <4> The polycarbonate resin according to any one of <1> to <4>, wherein

[0022] <6> The polycarbonate resin according to any one of <1> to <5>, wherein the repeating unit of the formula (4) is a repeating unit derived from bisphenol TMC.

[0023] <7> The absolute value of orientation birefringence is 10.0 × 10 －３ <6> The polycarbonate resin according to any one of <1> to <6>, which is:

[0024] <8> Photoelastic coefficient is 25×10 －１２ <7> The polycarbonate resin according to any one of <1> to <7>, wherein the viscosity is less than Pa.

[0025] <9> The polycarbonate resin according to any one of <1> to <8>, which has an Abbe number of 25.0 or more.

[0026] <10> An optical member made of the polycarbonate resin according to any one of <1> to <9>.

[0027] <11> The optical member according to <10>, wherein the optical member is an imaging lens.

[0028] The second aspect of the present disclosure includes the following aspects.

[0029] <1> 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), 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 mol % and less than 50 mol %, and the polycarbonate resin has a weight average molecular weight Mw of 10,000 or more.

[0030]

[0031]

[0032]

[0033] (In the formula, R １ ~R ４ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms.

[0034] (In formula (4), n is a number ranging from 0 to 8, and each R independently represents an alkyl group having 1 to 3 carbon atoms.)

[0035] <2> The polycarbonate resin according to <1>, having a weight average molecular weight Mw of 10,000 or more and 60,000 or less.

[0036] <3> The polycarbonate resin according to <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.

[0037] <4> The polycarbonate resin according to any one of <1> to <3>, wherein the repeating unit of the formula (4) accounts for more than 0 mol % and not more than 45 mol % of all repeating units of the resin.

[0038] <5> R in the formula (3) １ ~R ４ <4> The polycarbonate resin according to any one of <1> to <4>, wherein

[0039] <6> The polycarbonate resin according to any one of <1> to <5>, wherein the repeating unit of the formula (4) is a repeating unit derived from bisphenol TMC.

[0040] <7> The absolute value of orientation birefringence is 10.0 × 10 －３ <6> The polycarbonate resin according to any one of <1> to <6>, which is:

[0041] <8> Photoelastic coefficient is 40 × 10 －１２ <7> The polycarbonate resin according to any one of <1> to <7>, wherein the modulus of elasticity is 100 Pa or less.

[0042] <9> The polycarbonate resin according to any one of <1> to <8>, having a refractive index nd of 1.550 or more.

[0043] <10> The polycarbonate resin according to any one of <1> to <9>, having a glass transition temperature of 140°C or higher.

[0044] <11> An optical member made of the polycarbonate resin according to any one of <1> to <10>.

[0045] <12> The optical member according to <11>, wherein the optical member is an imaging lens.

[0046] The polycarbonate resin of the first embodiment of the present disclosure has an excellent balance between the refractive index and the Abbe number, and further has small orientation birefringence and photoelastic coefficient, and therefore has exceptional industrial effects.

[0047] The polycarbonate resin of the second embodiment of the present disclosure has small orientation birefringence, and a high refractive index and glass transition temperature, and therefore has exceptional industrial effects.

[0048] Fig. 1 shows the relationship between the refractive index and Abbe number of a thermoplastic resin according to a first embodiment of the present disclosure and a conventional resin, while Fig. 2 shows the relationship between the refractive index and Abbe number of a thermoplastic resin according to a second embodiment of the present disclosure and a conventional resin.

[0049] Hereinafter, embodiments of the present disclosure will be described. These descriptions and examples are intended to illustrate the embodiments and are not intended to limit the scope of the embodiments. Unless otherwise specified, matters described as "of the present disclosure" or "in the present disclosure" are common to the first and second embodiments.

[0050] In the present disclosure, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in the present disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in the numerical ranges described in the present disclosure, the upper or lower limit value of that numerical range may be replaced with a value shown in an example.

[0051] <Polycarbonate resin of the present disclosure>

[0052] The polycarbonate resin of the first embodiment of the present disclosure 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), wherein the total amount of repeating units represented by formula (1) and / or formula (2) in all repeating units of the resin is 50 mol % or more.

[0053] The polycarbonate resin of the second embodiment of the present disclosure 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), wherein the total content of repeating units represented by formula (1) and / or formula (2) in all repeating units of the resin is more than 0 mol% and less than 50 mol%.

[0054] In the present disclosure, in the definition of mol % described above, the total of repeating units represented by formula (1) and / or formula (2) refers to the total units of formula (1) and formula (2) when the polycarbonate resin contains units represented by formula (1) and formula (2), and refers to either one of the units represented by formula (1) or formula (2) when the polycarbonate resin contains either one of the units contained.

[0055]

[0056]

[0057]

[0058] (In the formula, R １ ~R ４ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms.

[0059] (In formula (4), n is a number ranging from 0 to 8, and each R independently represents an alkyl group having 1 to 3 carbon atoms.)

[0060] (Weight average molecular weight)

[0061] The polycarbonate resin of the first embodiment of the present disclosure 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 55,000 or less, even more preferably 50,000 or less, and even more preferably 45,000 or less. A weight-average molecular weight Mw of 60,000 or less is preferable because it has excellent fluidity during injection molding. In particular, the polycarbonate resin of the first embodiment of the present disclosure is preferable because it has excellent fluidity when used for thin-walled optical components such as imaging lenses.

[0062] The polycarbonate resin of the second embodiment of the present disclosure 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 has excellent fluidity during injection molding. In particular, the polycarbonate resin of the second embodiment of the present disclosure is preferable because it has excellent fluidity when used for thin-walled optical components such as imaging lenses.

[0063] In the present disclosure, the weight average molecular weight Mw can be measured by GPC using polystyrene with a known molecular weight as a standard sample and chloroform as a developing solvent.

[0064] (Absolute value of orientation birefringence)

[0065] The polycarbonate resin of the first embodiment of the present disclosure has an absolute value of orientation birefringence of 10.0 × 10 －３ It is preferable that the value is 9.0 × 10 or less. －３ More preferably, it is 8.0 × 10 or less. －３ It is even more preferable that the value is 7.0 x 10 or less. －３ More preferably, it is 6.0 × 10 or less. －３ It is particularly preferable that the value is 5.0 × 10 or less. －３ More preferably, it is 4.0 × 10 or less. －３ It is most preferable that the absolute value of the orientation birefringence is not more than the above range, since birefringence due to molecular orientation is unlikely to occur.

[0066] The polycarbonate resin of the second embodiment of the present disclosure has an absolute value of orientation birefringence of 10.0 × 10 －３ It is preferable that the value is 8.5×10 or less. －３ More preferably, it is 5.5 × 10 or less. －３ It is even more preferable that the value is 3.0 x 10 or less. －３ It is more preferable that the value is 1.5×10 or less. －３It is even more preferable that the value is 1.0 × 10 or less. －３ It is particularly preferable that the value is 0.5 × 10 or less. －３ It is most preferable that the absolute value of the orientation birefringence is not more than the above range, since birefringence due to molecular orientation is unlikely to occur.

[0067] In the present disclosure, orientation birefringence is measured at a wavelength of 589 nm by cutting a test piece 70 mm long (45 mm between chucks) and 15 mm wide from a cast film having a thickness of 100 μm obtained from a polycarbonate resin, stretching the test piece 2 times at Tg+10°C, and then measuring the orientation birefringence at a wavelength of 589 nm.

[0068] (Photoelastic Coefficient)

[0069] The polycarbonate resin of the first embodiment of the present disclosure has a photoelastic coefficient of 25×10 －１２ Pa, and preferably less than 20 × 10 －１２ Pa or less is more preferable, and 16×10 －１２ Pa or less is more preferable, and 12×10 －１２ It is more preferable that the photoelastic coefficient is not more than 100 Pa. When the photoelastic coefficient is in the above range, birefringence due to stress is unlikely to occur, which is preferable.

[0070] The polycarbonate resin of the second embodiment of the present disclosure has a photoelastic coefficient of 40×10 －１２ Pa, and preferably less than 35 × 10 －１２ Pa or less is more preferable, and 30×10 －１２ Pa or less is more preferable, and 25×10 －１２ It is more preferable that the photoelastic coefficient is not more than 100 Pa. When the photoelastic coefficient is in the above range, birefringence due to stress is unlikely to occur, which is preferable.

[0071] In the present disclosure, 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 polycarbonate resin, and using a Spectroellipsometer M-220 manufactured by JASCO Corporation.

[0072] (Refractive Index)

[0073] The polycarbonate resin of the first embodiment of the present disclosure preferably has a refractive index nd measured at a temperature of 20°C and a wavelength of 587.56 nm of 1.540 or more, more preferably 1.550 or more, even more preferably 1.560 or more, even more preferably 1.570 or more, and particularly preferably 1.575 or more. A refractive index of at least the above range is preferred because it allows optical components to be made thinner. Furthermore, the refractive index nd may be 1.610 or less, 1.600 or less, 1.590 or less, or 1.580 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.

[0074] The polycarbonate resin of the second embodiment of the present disclosure 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 optical components to be made thinner. 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.

[0075] In this disclosure, the refractive index nd (587.56 nm) is measured using a Kalnew Precision Refractometer KPR-2000 manufactured by Shimadzu Corporation.

[0076] (Abbe number)

[0077] The polycarbonate resin of the first embodiment of the present disclosure preferably has an Abbe number of 25.0 or more, more preferably 30.0 or more, even more preferably 32.0 or more, even more preferably 37.0 or more, particularly preferably 42.0 or more, and most preferably 46.0 or more. An Abbe number of at least the above ranges is preferable because it reduces chromatic aberration of the optical member. Furthermore, the Abbe number may be 57.0 or less, 55.0 or less, 50.0 or less, or 47.0 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.

[0078] The polycarbonate resin of the second embodiment of the present disclosure 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 the optical member. The Abbe number may also be 35.0 or less, or may be 34.0 or less. An Abbe number within the above range is preferable because it increases the degree of freedom in optical design when using a combination of multiple lenses.

[0079] Here, the Abbe number (νd) in the present disclosure is calculated using the following formula from the refractive indexes at a temperature of 20° C. and wavelengths of 486.13 nm, 587.56 nm, and 656.27 nm.

[0080] νd=(nd−1) / (nF−nC) where nd is the refractive index at a wavelength of 587.56 nm, nF is the refractive index at a wavelength of 486.13 nm, and nC is the refractive index at a wavelength of 656.27 nm.

[0081] The refractive index and Abbe number of the polycarbonate resin of the present disclosure preferably satisfy the following mathematical formula (A):

[0082] nd≧−0.0063×νd+α (A)

[0083] Here, in the first embodiment of the present disclosure, α in formula (A) is preferably 1.767 or more, more preferably 1.770 or more, even more preferably 1.773 or more, still more preferably 1.776 or more, and most preferably 1.779 or more. Preferably, nd>1.535.

[0084] On the other hand, in the second embodiment of the present disclosure, α in formula (A) 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. Preferably, nd>1.535.

[0085] The refractive index and Abbe number of the polycarbonate resin of the first embodiment of the present disclosure may satisfy the following mathematical formula (B):

[0086] nd≦-0.0023×νd+β (B)

[0087] In formula (B), β may be 1.675 or less, 1.673 or less, 1.671 or less, 1.669 or less, or 1.666 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.

[0088] On the other hand, the refractive index and Abbe number of the polycarbonate resin of the second embodiment of the present disclosure may satisfy the following mathematical formula (B').

[0089] nd≦-0.0057×νd+β (B')

[0090] 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 in the above ranges, the Abbe number relative to the refractive index is high, which is preferable since it broadens the scope of optical design.

[0091] (glass transition temperature)

[0092] The polycarbonate resin of the first embodiment of the present disclosure preferably has a glass transition temperature of 130°C or higher, more preferably 133°C or higher, and even more preferably 136°C or higher. A glass transition temperature in the above range is preferred because it broadens the temperature range in which optical components can be used. Furthermore, the glass transition temperature may be 155°C or lower, 150°C or lower, 145°C or lower, or 140°C or lower. A glass transition temperature in the above range is preferred because it provides an excellent balance between heat resistance and moldability.

[0093] The polycarbonate resin of the second embodiment of the present disclosure 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. Furthermore, the glass transition temperature may 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.

[0094] In the present disclosure, the glass transition temperature of a polycarbonate resin is measured using a Discovery DSC 25Auto model manufactured by TA Instruments Japan, Inc., at a temperature rise rate of 20°C / min.

[0095] (pyrolysis temperature)

[0096] The polycarbonate resin of the first embodiment of the present disclosure preferably has a thermal decomposition temperature of 370°C or higher, more preferably 374°C or higher. A thermal decomposition temperature of 370°C or higher is preferable because the polycarbonate resin of the first embodiment of the present disclosure has excellent processing stability when molded and is less likely to be discolored. The thermal decomposition temperature may also be 420°C or lower, or 400°C or lower.

[0097] The polycarbonate resin of the second embodiment of the present disclosure 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. A thermal decomposition temperature of 370°C or higher is preferable because the polycarbonate resin of the second embodiment of the present disclosure has excellent processing stability when molded and is less likely to be discolored. The thermal decomposition temperature may also be 420°C or lower, or 400°C or lower.

[0098] In the present disclosure, the thermal decomposition temperature can be measured by TGA (thermogravimetric analysis) and is the temperature at which the weight decreases by 5%.

[0099] (specific viscosity)

[0100] The specific viscosity of the polycarbonate resin of the first embodiment of the present disclosure 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.

[0101] The specific viscosity of the polycarbonate resin of the second embodiment of the present disclosure 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.

[0102] In the present disclosure, the specific viscosity is measured by measuring the specific viscosity (ηSP) at 20°C of a solution in which 0.7 g of polycarbonate resin is dissolved in 100 ml of methylene chloride using an Ostwald viscometer, and calculating the specific viscosity using the following formula.

[0103] ηSP=(t-t0) / t0

[0104] [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]

[0105] (partial dispersion ratio)

[0106] The partial dispersion ratio (θgF) from the g-line to the F-line of the polycarbonate resin of the first embodiment of the present disclosure is preferably 0.62 or less, more preferably 0.61 or less, even more preferably 0.60 or less, still more preferably 0.59 or less, and most preferably 0.58 or less. When θgF is less than the above range, the scope of optical design is broadened, which is preferable.

[0107] The partial dispersion ratio (θgF) from the g-line to the F-line of the polycarbonate resin of the second embodiment of the present disclosure 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. When θgF is less than the above range, the scope of optical design is broadened, which is preferable.

[0108] Here, the partial dispersion ratio (θgF) from the g-line to the F-line in the present disclosure 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.

[0109] θgF=(ng−nF) / (nF−nC) where ng is the refractive index at a wavelength of 435.83 nm, nF is the refractive index at a wavelength of 486.13 nm, and nC is the refractive index at a wavelength of 656.27 nm.

[0110] (Formula (3))

[0111] In the polycarbonate resin of the present disclosure, 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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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 １and 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.

[0116] 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 has low orientation birefringence and photoelastic coefficient, making it more preferable for the polycarbonate resin of the first aspect of the present disclosure. Also, because of its low orientation birefringence, it is more preferable for the polycarbonate resin of the second aspect of the present disclosure.

[0117] (Formula (4))

[0118] In the polycarbonate resin of the present disclosure, n in the above formula (4) is in the range of 0 to 8, preferably 0 to 5 or 1 to 3, and particularly preferably 3, because the glass transition temperature is high.

[0119] Each R is selected from alkyl groups having 1 to 3 carbon atoms, preferably a methyl group or an ethyl group, and in particular, a methyl group is preferred because of its high glass transition temperature.

[0120] 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.

[0121] (Equation (1) and Equation (2))

[0122] In the polycarbonate resin of the present disclosure, the repeating units represented by the above formula (1) and / or the above formula (2) are repeating units derived from pentacyclopentadecanedimethanol, and the above formula (1) and / or the above formula (2) may be pure substances or mixtures of the respective isomers mixed in any ratio. Pentacyclopentadecanedimethanol includes the following structural formula:

[0123]

[0124]

[0125] (Other repeating units)

[0126] The polycarbonate resin of the present disclosure may contain repeating units other than the repeating units represented by the above formulas (1) to (4), as long as the advantageous effects of the present disclosure are obtained. Examples of dihydroxy compounds that provide 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.

[0127] (Repeating unit amount)

[0128] In the polycarbonate resin of the present disclosure, 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.

[0129] In the polycarbonate resin of the first embodiment of the present disclosure, the total content of repeating units represented by the above formula (1) and / or formula (2) in all repeating units of the resin is 50 mol % or more, more preferably 55 mol % or more, and even more preferably 60 mol % or more, in which case the Abbe number is high.

[0130] In the polycarbonate resin of the first embodiment of the present disclosure, the repeating unit represented by the above formula (3) may be more than 0 mol%, 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, or may be 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 repeating unit is preferably more than 0 mol% and 50 mol% or less, more preferably 2 to 45 mol%, and even more preferably 2 to 40 mol% because orientation birefringence is low.

[0131] In the polycarbonate resin of the first embodiment of the present disclosure, the repeating unit represented by the above formula (4) may account for 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, or 25 mol% or more, or may be 40 mol% or less, 35 mol% or less, 30 mol% or less, 25 mol% or less, or 20 mol% or less. The repeating unit is preferably more than 0 mol% and 40 mol% or less, more preferably 2 to 35 mol%, and even more preferably 3 to 30 mol% because the glass transition temperature is high.

[0132] In the polycarbonate resin of the second embodiment of the present disclosure, the total content of the repeating units represented by the above 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 repeating units are greater than 0 mol% and 50 mol% or less, and are 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.

[0133] In the polycarbonate resin of the second embodiment of the present disclosure, the total content of repeating units represented by the above 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 repeating units are preferably 10 mol% to 95 mol%, more preferably 12 mol% to 94 mol%, and even more preferably 15 mol% to 93 mol%, as orientation birefringence is low.

[0134] In the polycarbonate resin of the second embodiment of the present disclosure, the repeating unit represented by the above formula (4) 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, or 35 mol% or more, or may be 45 mol% or less, 40 mol% or less, 30 mol% or less, 25 mol% or less, or 20 mol% or less. The repeating unit is preferably more than 0 mol% and 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.

[0135] (Terminal phenolic hydroxyl group)

[0136] The polycarbonate resin of the present disclosure 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 a 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 into a phenyl group.

[0137] The ratio of terminal phenolic hydroxyl groups can be determined as follows.

[0138] Terminal phenolic hydroxyl group ratio=(amount of terminal phenolic hydroxyl groups / total amount of terminals)×100

[0139] All of the terminals consist of a terminal phenolic hydroxyl group, a terminal alcoholic hydroxyl group, and a terminal phenyl group.

[0140] Although not limited to this example, specifically, the terminal phenolic hydroxyl group ratio can be determined by the following method.

[0141] (1) The terminal phenolic hydroxyl group of the polycarbonate resin １The terminal phenolic hydroxyl group is observed by H NMR measurement, and the integral of the corresponding peak is taken and set as 1. At the same time, the integral intensity (A) of one proton of the fluorene structure is calculated from the integral intensities of the peaks at positions 4 and 5 of the fluorene structure derived from the above formula (3). When no peak of the terminal phenolic hydroxyl group is observed, the terminal phenolic hydroxyl group ratio is 0.

[0142] (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:

[0143] (B) = (A) × 100 × 2 / ([mol % of the above formula (3)] × average degree of polymerization)

[0144] (3) The terminal phenolic hydroxyl group ratio is calculated as 1 / (B)×100.

[0145] The ratio of terminal phenolic hydroxyl groups to all terminals of the polycarbonate resin of the present disclosure 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 hue change due to wet heat.

[0146] (Total light transmittance)

[0147] The polycarbonate resin of the present disclosure 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 disclosure to injection molding, hot press molding, melt extrusion molding, or the like.

[0148] In the present disclosure, the total light transmittance can be measured using a color and turbidity simultaneous measuring instrument COH 400 (D65 light source, 10° field of view) manufactured by Nippon Denshoku Industries Co., Ltd.

[0149] (saturated water absorption rate)

[0150] The saturated water absorption of the polycarbonate resin of the present disclosure may be 0.10% to 0.70%, 0.20% to 0.70%, or 0.30% to 0.65%.

[0151] In the present disclosure, the saturated water absorption is calculated by measuring the weight change when a test piece of 50 mm × 40 mm × 2 mm is immersed in water at 23°C, and then calculating it using the following formula: Saturated water absorption (%) = (W ｓ -W ０ ) x 100 / W ０ W ０ W: Weight of test piece after drying at 50°C for 48 hours and cooling in a desiccator for 1 hour ｓ : Weight of test piece when the weight change is saturated after immersing the test piece in water

[0152] <Method for producing polycarbonate resin>

[0153] The polycarbonate resin of the present disclosure 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.

[0154] 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.

[0155] Examples of the carbonate diester used in the transesterification reaction include esters of an aryl group or 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.

[0156] 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.

[0157] 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.

[0158] 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.

[0159] 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.

[0160] 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 include bases or basic salts such as tetramethylammonium borohydride, tetrabutylammonium borohydride, tetrabutylammonium tetraphenylborate, and tetraphenylammonium tetraphenylborate.

[0161] 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 (II) chloride, tin (IV) chloride, tin (II) acetate, tin (IV) acetate, dibutyltin dilaurate, dibutyltin oxide, dibutyltin dimethoxide, zirconium acetylacetonate, zirconium oxyacetate, zirconium tetrabutoxide, lead (II) acetate, lead (IV) acetate, titanium tetrabutoxide (IV), etc. The catalysts used in WO 2011 / 010741 and JP 2017-179323 A may also be used.

[0162] Furthermore, a catalyst comprising aluminum or a compound thereof and a phosphorus compound may be used, and in this 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.

[0163] 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.

[0164] 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.

[0165] 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 mol of the dihydroxy component.

[0166] 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.

[0167] 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.

[0168] 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.

[0169] <Optional Additives>

[0170] The polycarbonate resin of the present disclosure 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.

[0171] 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, and 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, relative to 100 parts by weight of the polycarbonate resin.

[0172] Examples of the heat stabilizer include phosphorus-based heat stabilizers, sulfur-based heat stabilizers, and hindered phenol-based heat stabilizers.

[0173] 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.

[0174] 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 per 100 parts by weight of the polycarbonate resin.

[0175] 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.

[0176] The content of the hindered phenol-based heat stabilizer is preferably 0.001 to 0.3 parts by weight per 100 parts by weight of the polycarbonate resin.

[0177] The phosphorus-based heat stabilizer and the hindered phenol-based heat stabilizer can also be used in combination.

[0178] 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.

[0179] 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.

[0180] Benzophenone-based ultraviolet absorbers include 2-hydroxy-4-n-dodecyloxybenzophenone and 2-hydroxy-4-methoxy-2'-carboxybenzophenone.

[0181] 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.

[0182] As the cyclic iminoester-based ultraviolet absorber, 2,2'-p-phenylenebis(3,1-benzoxazin-4-one) is particularly suitable.

[0183] 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.

[0184] The blending amount of the ultraviolet absorber is preferably 0.01 to 3.0 parts by weight per 100 parts by weight of the polycarbonate resin, and within this blending amount range, it is possible to impart sufficient weather resistance to molded articles of the polycarbonate resin depending on the application.

[0185] <Optical components>

[0186] The optical member of the present disclosure contains the polycarbonate resin described above. Examples of such an optical member are not particularly limited as long as they are used for optical applications in which the polycarbonate resin is useful, and include optical disks, transparent conductive substrates, optical cards, sheets, films, optical fibers, lenses, prisms, optical films, substrates, optical filters, and hard coat films.

[0187] Furthermore, the optical member of the present disclosure 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.

[0188] <Optical lenses>

[0189] The optical member of the present disclosure 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, in-vehicle cameras, surveillance cameras, etc., and sensing cameras such as time-of-flight cameras. The optical member of the present disclosure is particularly useful as an imaging lens.

[0190] When the optical lens of the present disclosure is manufactured by injection molding, molding is preferably performed under conditions of a cylinder temperature of 220 to 350°C and a mold temperature of 70 to 180°C. More preferably, molding is performed 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.

[0191] The optical lens of the present disclosure is preferably implemented in the form of an aspherical lens as necessary. Since an aspherical lens can substantially eliminate spherical aberration with a single lens, it is not necessary to eliminate spherical aberration by combining multiple spherical lenses, which enables weight reduction and reduction in molding costs. Therefore, aspherical lenses are particularly useful as camera lenses, among other optical lenses.

[0192] Furthermore, the polycarbonate resin of the present disclosure 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 convex surface and one concave surface.

[0193] Lenses made of the polycarbonate resin of the present disclosure 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 from the standpoint of production costs.

[0194] The polycarbonate resin of the present disclosure will be described in more detail below with reference to examples. The materials, amounts used, ratios, processing procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present disclosure. Therefore, the scope of the polycarbonate resin of the present disclosure should not be interpreted as being limited by the specific examples shown below.

[0195] (Measurement Methods and Evaluation Methods) The measurement methods and evaluation methods applied to the examples and comparative examples are as follows.

[0196] <Copolymerization ratio of polycarbonate resin> JEOL JNM-ECZ400S １ The copolymerization ratio of each polycarbonate resin was calculated by measuring 1 H NMR.

[0197] <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.

[0198] Detector: UV-8420, solvent: chloroform, column: TOSOH TSKgel Supermultipore HZM-M × 3 + TSKgel guard column (4.6 × 200 nm), measurement temperature: 40°C, flow rate: 0.35 ml / min, injection amount: 5 μl, sample concentration: 1 mg / 5 ml, standard sample: TSKstandard Polystyrene

[0199] <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.

[0200] <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.

[0201] νd=(nd−1) / (nF−nC) where nd is the refractive index at a wavelength of 587.56 nm, nF is the refractive index at a wavelength of 486.13 nm, and nC is the refractive index at a wavelength of 656.27 nm.

[0202] <Absolute Value of Orientation Birefringence (|Δn|)> A polycarbonate resin was dissolved in methylene chloride, cast onto a glass petri dish, and thoroughly dried to produce a cast film with a thickness of 100 μm. A test piece with a length of 70 mm (45 mm between chucks) and a width of 15 mm was cut out from the film and stretched twice at Tg+10°C. The retardation (Re) at 589 nm was measured using an Ellipsometer M-220 manufactured by JASCO Corporation, and the absolute value of orientation birefringence (|Δn|) was calculated using the following formula:

[0203] |Δn|=|Re / d| Δn: Orientation birefringence Re: Phase difference (nm) d: Thickness (nm)

[0204] <Photoelastic Coefficient> A polycarbonate resin was dissolved in methylene chloride, cast onto a glass dish, and thoroughly dried to prepare a cast film with a thickness of 100 μm. A test piece with a length of 50 mm and a width of 10 mm was cut out from the film, and the photoelastic coefficient was measured using an Ellipsometer M-220 manufactured by JASCO Corporation.

[0205] <Glass Transition Temperature (Tg)> The glass transition temperature (Tg) of the obtained polycarbonate resin was measured at a temperature rise rate of 20°C / min using a Discovery DSC 25Auto model manufactured by TA Instruments Japan Co., Ltd. The measurement was carried out using a sample weighing 5 to 10 mg.

[0206] <Thermal decomposition temperature (Td-5)> The obtained polycarbonate resin was measured at a temperature increase rate of 20°C / min using an SDT650 model manufactured by TA Instruments Japan Co., Ltd., and the temperature at which the weight decreased by 5% was determined based on the weight at 50°C. The measurement was performed on a sample of 3 to 4 mg.

[0207] <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.

[0208] θgF=(ng−nF) / (nF−nC) where ng is the refractive index at a wavelength of 435.83 nm, nF is the refractive index at a wavelength of 486.13 nm, and nC is the refractive index at a wavelength of 656.27 nm.

[0209] <Proportion of Terminal Phenolic Hydroxyl Groups> The proportion of terminal phenolic hydroxyl groups can be determined as follows.

[0210] Terminal phenolic hydroxyl group ratio=(amount of terminal phenolic hydroxyl groups / total amount of terminals)×100

[0211] Specifically, the terminal phenolic hydroxyl group ratio can be determined by the following method.

[0212] (1) The terminal phenolic hydroxyl group of the polycarbonate resin １ The terminal phenolic hydroxyl group is observed by H NMR measurement, and the integral of the corresponding peak is taken and set as 1. At the same time, the integral intensity (A) of one proton of the fluorene structure is calculated from the integral intensities of the peaks at positions 4 and 5 of the fluorene structure derived from the above formula (3). When no peak of the terminal phenolic hydroxyl group is observed, the terminal phenolic hydroxyl group ratio is 0.

[0213] (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:

[0214] (B) = (A) × 100 × 2 / ([mol % of the above formula (3)] × average degree of polymerization)

[0215] (3) The terminal phenolic hydroxyl group ratio is calculated as 1 / (B)×100.

[0216] (Polycarbonate Resin of First Form) Example 1-1 3.51 g (0.01 mol) of 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene (hereinafter sometimes abbreviated as BPEF), 97.61 g (0.37 mol) of pentacyclopentadecanedimethanol (hereinafter sometimes abbreviated as PCPDM), 6.2 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 sodium hydrogen carbonate solution (sodium hydrogen carbonate 1 μmol) and 22 μL of a 274 mmol / L aqueous tetramethylammonium hydroxide solution (tetramethylammonium hydroxide 6 μmol) as catalysts were heated to 180° C. in a nitrogen atmosphere and melted. Thereafter, the reactor internal pressure was reduced to 20 kPa over 40 minutes, while the temperature was raised to 250°C at a rate of 60°C / hr. After 70% of the theoretical amount of phenol was distilled off, the reactor internal pressure was reduced to 133 Pa or less over 1 hour. The reaction was then terminated by stirring at 260°C for 40 minutes with the reactor internal pressure at 133 Pa or less, and the resin was taken out. 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%.

[0217] Example 1-2 A polycarbonate resin was produced in the same manner as in Example 1-1, except that the amount of BPEF charged was 22.80 g (0.5 mol) and the amount of PCPDM charged was 86.06 g (0.33 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%.

[0218] Example 1-3 A polycarbonate resin was produced in the same manner as in Example 1-1, except that the amount of BPEF charged was 31.57 g (0.07 mol) and the amount of PCPDM charged was 80.82 g (0.31 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%.

[0219] Example 1-4 A polycarbonate resin was produced in the same manner as in Example 1-1, except that the amount of BPEF charged was 61.39 g (0.14 mol) and the amount of PCPDM charged was 62.97 g (0.24 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%.

[0220] Example 1-5 A polycarbonate resin was produced in the same manner as in Example 1-1, except that the amount of BPEF charged was 70.16 g (0.16 mol), the amount of PCPDM charged was 52.48 g (0.2 mol), and the amount of BisTMC charged was 12.40 g (0.04 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%.

[0221] Example 1-6 A polycarbonate resin was produced in the same manner as in Example 1-1, except that the amount of BPEF charged was 17.54 g (0.04 mol), the amount of PCPDM charged was 62.97 g (0.24 mol), and the amount of BisTMC charged was 37.2 g (0.12 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%.

[0222] <Comparative Example 1-1> 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. Thereafter, 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 was completed, the pressure inside the reactor was reduced to 133 Pa (1 mmHg) or less over 1 hour while maintaining that temperature. 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 with stirring. After the reaction was completed, nitrogen was blown into the reactor to return the pressure to normal, 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, θgF, glass transition temperature, thermal decomposition temperature, absolute value of orientation birefringence, and photoelastic coefficient of the polycarbonate resin were measured by H NMR.

[0223] Comparative Example 1-2 A polycarbonate resin was produced in the same manner as in Comparative Example 1-1, 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.

[0224] Comparative Example 1-3 A polycarbonate resin was produced in the same manner as in Comparative Example 1-1, except that the amount of BPA charged was 27.40 g (0.12 mol) and the amount of PCPDM charged was 73.47 g (0.28 mol). The copolymerization ratio of BPA and PCPDM in the obtained polycarbonate resin was １The 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.

[0225] Comparative Example 1-4: 103.49 g (0.24 mol) of BPEF, 37.80 g (0.12 mol) of 3,9-bis(2-hydroxy-1,1-dimethylethyl)-2,4,8,10-tetraoxaspiro(5.5)undecane (hereinafter referred to as "SPG"), 12.42 g (0.04 mol) of BisTMC, 89.11 g (0.42 mol) of diphenyl carbonate, and 0.033 mL of a 60 mmol / L aqueous sodium bicarbonate solution (sodium bicarbonate 2.0 μmol) 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 after completion of the reaction, the resin was taken out from the flask. 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.

[0226] Comparative Example 1-5 A polycarbonate resin was produced in the same manner as in Comparative Example 1-4, except that the amount of BPEF charged was 96.47 g (0.22 mol), the amount of SPG charged was 38.96 g (0.13 mol), and the amount of BisTMC charged was 16.12 g (0.05 mol). 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.

[0227] Comparative Example 1-6 A polycarbonate resin was produced in the same manner as in Comparative Example 1-4, except that the amount of BPEF charged was 21.05 g (0.05 mol), the amount of SPG charged was 69.40 g (0.23 mol), and the amount of BisTMC charged was 38.44 g (0.12 mol). 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.

[0228]

[0229] The polycarbonate resins in Examples 1-1 to 1-6 of the first embodiment of the present disclosure exhibited the characteristics of maintaining a high balance between the refractive index (nd) and the Abbe number (νd), while also exhibiting small orientation birefringence (|Δn|) and photoelastic coefficient.

[0230] Compared with Comparative Examples 1-1 and 1-2 corresponding to the examples of Patent Document 1, Examples 1-1 to 1-6 of the first embodiment of the present disclosure are superior in orientation birefringence, and therefore are less likely to suffer from birefringence due to molecular orientation when obtaining an optical member by injection molding or the like. In addition, because the photoelastic coefficient is small, birefringence due to stress is less likely to occur when obtaining an optical member by injection molding or the like. Therefore, these are preferable because the birefringence of the optical member is reduced.

[0231] Example 1-2 of the first embodiment of the present disclosure is preferable because it has a higher glass transition temperature and is superior in heat resistance compared to Comparative Example 1-3.

[0232] Examples 1-1 to 1-3 and 1-6 of the first embodiment of the present disclosure have a higher refractive index while having an Abbe number equal to or greater than that of Comparative Example 1-6, which corresponds to an example of Patent Document 4, and thus enable the optical lens to be made thinner.

[0233] Compared with Comparative Example 1-5 corresponding to the example of Patent Document 3, Example 1-4 of the first embodiment of the present disclosure has a higher Abbe number despite having the same refractive index, thereby enabling a wider range of optical design.

[0234] Compared with Comparative Examples 1-4 and 1-5 corresponding to the examples of Patent Document 3, Examples 1-5 of the first embodiment of the present disclosure have a higher Abbe number despite having the same refractive index, thereby enabling a wider range of optical design.

[0235] 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, whereas the polycarbonate resin of the first embodiment of the present disclosure has an Abbe number of 31.0 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.

[0236] (Polycarbonate Resin of Second Form) Example 2-1 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 sodium hydrogen carbonate solution (sodium hydrogen carbonate 1 μmol) and 22 μL of a 274 mmol / L aqueous tetramethylammonium hydroxide solution (tetramethylammonium hydroxide 6 μmol) as catalysts were heated to 180° C. in a nitrogen atmosphere and melted. Thereafter, the reactor internal pressure was reduced to 20 kPa over 40 minutes, while the temperature was raised to 250°C at a rate of 60°C / hr. After 70% of the theoretical amount of phenol was distilled off, the reactor internal pressure was reduced to 133 Pa or less over 1 hour. The reaction was then terminated by stirring at 260°C for 40 minutes with the reactor internal pressure at 133 Pa or less, and the resin was taken out. 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%.

[0237] Example 2-2 A polycarbonate resin was produced in the same manner as in Example 2-1, 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%.

[0238] Example 2-3 A polycarbonate resin was produced in the same manner as in Example 2-1, 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%.

[0239] Example 2-4 A polycarbonate resin was produced in the same manner as in Example 2-1, 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%.

[0240] Example 2-5 A polycarbonate resin was produced in the same manner as in Example 2-1, 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%.

[0241] Example 2-6 A polycarbonate resin was produced in the same manner as in Example 2-1, 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 the resulting polycarbonate resin derived from BPEF, PCPDM, and BisTMC 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%.

[0242] <Comparative Example 2-1> 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. Thereafter, 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 was completed, the pressure inside the reactor was reduced to 133 Pa (1 mmHg) or less over 1 hour while maintaining that temperature. 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 with stirring. After the reaction was completed, nitrogen was blown into the reactor to return the pressure to normal, 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.

[0243] Comparative Example 2-2 A polycarbonate resin was produced in the same manner as in Comparative Example 2-1, 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.

[0244] Comparative Example 2-3: 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 after the reaction was completed, the resin was removed from the flask. The copolymerization ratio of the resulting polycarbonate resin derived from BPEF, SPG, and BisTMC 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.

[0245] Comparative Example 2-4 A polycarbonate resin was produced in the same manner as in Comparative Example 2-3, 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.

[0246] Comparative Example 2-5 A polycarbonate resin was produced in the same manner as in Comparative Example 2-3, 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.

[0247] Comparative Example 2-6 A polycarbonate resin was produced in the same manner as in Comparative Example 2-3, 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.

[0248]

[0249] The polycarbonate resins in Examples 2-1 to 2-6 of the second embodiment of the present disclosure exhibited the characteristics of having a small orientation birefringence (|Δn|) and both a high refractive index (nd) and glass transition temperature (Tg).

[0250] Examples 2-1 to 2-6 of the second embodiment of the present disclosure are superior in orientation birefringence and photoelastic coefficient compared to Comparative Examples 2-1 and 2-2 corresponding to the examples of Patent Document 1, and therefore are less likely to suffer from birefringence due to molecular orientation or stress when obtaining optical components by injection molding, etc. Furthermore, because they have high refractive indices and glass transition temperatures, they are preferable as optical components.

[0251] Examples 2-2 and 2-3 of the second embodiment of the present disclosure are preferable because they have superior orientation birefringence compared to Comparative Examples 2-3 to 2-6, 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.

[0252] Example 2-4 of the second embodiment of the present disclosure has a higher Abbe number than Comparative Example 2-4, which corresponds to the example of Patent Document 4, while having the same refractive index, and thus allows for a wider range of optical design. In addition, Example 2-4 is preferable because it has a higher glass transition temperature and excellent heat resistance.

[0253] In Examples 2-5 and 2-6 of the second embodiment of the present disclosure, by replacing SPG with PCPDM while maintaining the same copolymerization ratio, the refractive index is higher and the optical lens can be made thinner while maintaining the same Abbe number, compared to Comparative Examples 2-5 and 2-6 corresponding to the examples in Patent Documents 3 and 4. Furthermore, these examples are preferable because they have a high glass transition temperature and excellent heat resistance.

[0254] 2, when the refractive index and Abbe number are plotted, the comparative example has an Abbe number of 27.6 at a high refractive index, whereas the polycarbonate resin of the second embodiment of the present disclosure 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.

[0255] The polycarbonate resin of the present disclosure is used in optical materials and can be used for optical components 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.

[0256] The disclosure of Japanese Application No. 2024-013876, filed February 1, 2024, is incorporated herein by reference in its entirety. The disclosure of Japanese Application No. 2024-013878, filed February 1, 2024, is incorporated herein by reference in its entirety.

[0257] All publications, patent applications, and technical standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, or technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. 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), wherein the total amount of repeating units represented by formula (1) and / or formula (2) among all repeating units of the resin is 50 mol% or more, and the weight average molecular weight Mw is 10,000 or more. (In the formula, R １ ~R ４ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. (In formula (4), n is a number ranging from 0 to 8, and each R independently represents an alkyl group having 1 to 3 carbon atoms.) 2. 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), wherein the total amount of repeating units represented by formula (1) and / or formula (2) among all repeating units of the resin is more than 0 mol% and less than 50 mol%, and the weight average molecular weight Mw is 10,000 or more. (In the formula, R １ ~R ４ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. (In formula (4), n is a number ranging from 0 to 8, and each R independently represents an alkyl group having 1 to 3 carbon atoms.) 3. The polycarbonate resin according to claim 1 or 2, wherein the weight average molecular weight Mw is 10,000 or more and 60,000 or less.

4. The polycarbonate resin according to claim 1, wherein the repeating units represented by formula (3) account for more than 0 mol % and not more than 50 mol % of all repeating units in the resin.

5. The polycarbonate resin according to claim 2, wherein the repeating units represented by formula (3) account for 10 mol % to 95 mol % of all repeating units in the resin.

6. The polycarbonate resin according to claim 1, wherein the repeating unit of formula (4) accounts for more than 0 mol % and not more than 40 mol % of all repeating units of the resin.

7. The polycarbonate resin according to claim 2, 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.

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

9. The polycarbonate resin according to claim 1 or 2, wherein the repeating unit of formula (4) is a repeating unit derived from bisphenol TMC.

10. The absolute value of orientation birefringence is 10.0 x 10 －３ 3. The polycarbonate resin according to claim 1 or claim 2, wherein:

11. Photoelastic coefficient is 25 x 10 －１２ 2. The polycarbonate resin of claim 1, wherein the viscosity is less than 100 MPa.

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

13. The polycarbonate resin according to claim 1, having an Abbe number of 25.0 or more.

14. The polycarbonate resin according to claim 2, having a refractive index nd of 1.550 or more.

15. The polycarbonate resin according to claim 2, having a glass transition temperature of 140°C or higher.

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

17. The optical element according to claim 16, wherein the optical element is an imaging lens.

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