A high refractive index polycarbonate resin, its preparation method and application

Abstract

The present invention discloses a high refractive index polycarbonate resin, its preparation method and application. The polycarbonate resin is formed by the reaction of a diol monomer with an ester bond, a fluorene-based or naphthalene-based monomer and a carbonic acid diester compound; preferably, an optical lens with a refractive index of 1.60 - 1.70 and an Abbe number less than 25 at 23 °C and 589 nm can be obtained by injection molding. Its optical transmittance is ≥ 85% in the wavelength range of 450 nm - 1100 nm, and the b value of a 1 mm sample plate injection-molded from the polycarbonate resin is less than 3, having industrialization prospects.

Description

Technical Field

[0001] The present invention relates to the field of polycarbonates, and particularly to a polycarbonate resin having a high refractive index, a low Abbe number, a low b value, and high light transmittance in a wide range of wavelengths, and a preparation method and application thereof. Background Art

[0002] Optical glass or optical resin plays an increasingly important role in people's daily lives. It has a wide range of applications and is crucial in various optical systems such as mobile phone lenses, vehicles, drones, VR (Virtual Reality), AR (Augmented Reality), etc. Optical glass has high transparency, excellent performance in heat resistance and refractive index, but it has high costs, difficult molding and processing, and low production efficiency. Especially the processing of aspherical lenses requires extremely high costs and technical thresholds, which limits its development in the rapidly growing optical material market.

[0003] Correspondingly, optical resin has advantages such as convenient molding, higher production efficiency, and controllable costs, and is currently increasingly favored by the lens market. The annual growth rate of shipments of high refractive index resin lenses is 10 - 15%, with a broad market and high versatility.

[0004] Bisphenol A polycarbonate resin is the most common and commonly used polycarbonate resin. When it was first used for optical lens applications, it was restricted by its own disadvantages such as low refractive index, high birefringence, and low glass transition temperature, and its applications in the market and different scenarios were restricted in many ways and it was difficult to continuously meet the growing needs of lens imaging quality. Developing polycarbonate resins with high refractive index and low birefringence can greatly improve imaging quality. A series of polycarbonate resins obtained by homopolymerization or copolymerization reactions of fluorene-based polyaromatic ring structure diols or diols with carbonic acid diesters have been developed. They have advantages such as high refractive index, small birefringence, and high glass transition temperature, and occupy a dominant position in the optical material market.

[0005] As mentioned above, in patent US5633331A, 9,9-bis-(4-hydroxyphenyl)fluorene and bisphenol A are used as comonomers, and the obtained copolycarbonate / polysulfone resin composition is used as the resin for optical lenses. Its refractive index is 1.627, with relatively large birefringence and poor imaging effect, and it has gradually lost favor in the market and has been replaced by products with higher refractive index and lower birefringence.

[0006] In patent CN201310062561.X, 9,9-bis-(4-(2-hydroxyethoxy)phenyl)fluorene is used as a comonomer, providing a polycarbonate resin that can be used for optical lenses and a manufacturing method thereof. The refractive index of this polycarbonate resin is 1.64 and it is used more in the low-end market of optical materials, but its refractive index still has relatively large limitations in high-end products.

[0007] Patent CN201380057423.0 discloses a polycarbonate resin, which mainly copolymerizes 2,2-bis-(2-hydroxyethoxy)-1,1-binaphthalene with fluorene monomers. The highest refractive index of the polycarbonate obtained in its examples is 1.665, which is applied to the mid- to high-end market and has excellent optical properties. However, although the polycarbonate resin obtained by copolymerizing such monomers has a high light transmittance under the conventional wavelength condition of 589 nm, its light transmittance is low in the low wavelength range (450 nm - 550 nm), often less than 85%, which limits its multi-scenario application, and such materials generally have a problem of yellowish color and a high b value.

[0008] Patent KR101743352B1 discloses a polycarbonate resin with a structure of bisphenol A derivative and a structure containing p-aryl diester, containing an ester bond, having excellent weather resistance, processability, and impact resistance. Its monomer composition is relatively single, still limited to ordinary bisphenol A polycarbonate, with limited application and poor optical properties, not belonging to the same category as high refractive index polycarbonate, and the discussion in this patent fails to improve its optical properties such as light transmittance at different wavelengths. Summary of the Invention

[0009] Aiming at the above deficiencies in the prior art, the purpose of the present invention is to provide a high refractive index polycarbonate resin for optical components and its preparation method. The present invention copolymerizes a glycol monomer with an ester bond with fluorene and naphthalene monomers to synthesize a high refractive index polycarbonate. This polycarbonate resin not only has properties such as high refractive index and low Abbe number, but also has a low b value. At the same time, the light transmittance of its injection-molded lens is ≥85% in the wavelength range of 450 - 1100 nm. The optical lens using this material has a high light transmittance in a wider range of wavelengths compared with other high refractive index polycarbonates, increasing its application scenarios and application effects, and the appearance of the lens is better, improving the common problem of its yellowing color. The manufacturing method of this polycarbonate resin is simple and has industrialization prospects.

[0010] To solve the above problems, the present invention provides a polycarbonate resin containing a structural unit represented by general formula (A).

[0011]

[0012] In general formula (A), Z represents a linear or branched alkylene group with 1 - 6 carbon atoms, an aromatic ring with 6 - 20 carbon atoms, an alicyclic ring with 3 - 20 carbon atoms, a heterocyclic ring such as furan, thiophene, pyrrole, thiazole, imidazole, pyridine, pyrazine, pyrimidine, pyridazine, indole, etc., preferably methyl, ethyl, phenyl, cyclopropyl, cyclohexyl, furan, more preferably methyl, ethyl, phenyl; X independently represents an alkylene group with 1 - 10 carbon atoms, preferably an alkylene group with 1 - 6 carbon atoms, more preferably methylene, ethylene, propylene, and further preferably ethylene.

[0013] In the present invention, as a preferred embodiment, the polycarbonate resin further comprises a structural unit represented by the general formula (B).

[0014]

[0015] In the general formula (B), Z1 each independently represents an aryl group having 6 to 24 carbon atoms, preferably a phenyl group, a naphthyl group, a biphenyl group, an anthryl group, or a phenanthryl group; R1 to R4 each independently represent a hydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, a cycloalkoxy group having 5 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aryloxy group having 6 to 20 carbon atoms, preferably a methyl group, an ethyl group, a phenyl group, a naphthyl group, or a biphenyl group; Y each independently represents an alkylene group having 1 to 10 carbon atoms, preferably an alkylene group having 1 to 6 carbon atoms, more preferably a methylene group, an ethylene group, or a propylene group; the value of m is each independently 0 to 10, preferably 0 to 2; the value of n is each independently 0 to 4, preferably 0 to 2.

[0016] Preferably, the polycarbonate resin of the present invention comprises a structural unit represented by the general formula (A) and a structural unit represented by the general formula (B), wherein the molar ratio (A / B) of the structural unit represented by the general formula (A) to the structural unit represented by the general formula (B) is 0.1 / 99.9 to 50 / 50, preferably 1 / 99 to 30 / 70.

[0017] As a preferred embodiment, the polycarbonate resin further comprises a structural unit represented by the general formula (C).

[0018]

[0019] In the general formula (C), W represents an alkylene group having 1 to 10 carbon atoms, preferably an alkylene group having 1 to 3 carbon atoms; R5 to R8 each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, a cycloalkoxy group having 5 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aryloxy group having 6 to 20 carbon atoms, preferably a hydrogen atom, a methyl group, an ethyl group, a phenyl group, a naphthyl group, or a biphenyl group.

[0020] As a preferred embodiment, the polycarbonate resin of the present invention comprises structural units represented by the general formula (A), the general formula (B), and the general formula (C), wherein

[0021] the proportion of the structural unit represented by the general formula (A) is 0.1 to 50 mol%, preferably 1 to 30 mol%,

[0022] the proportion of the structural unit represented by the general formula (B) is 0.1 to 99.8 mol%, preferably 20 to 60 mol%,

[0023] The proportion of the structural unit represented by the general formula (C) is 0.1 to 99.8 mol%, preferably 30 to 70 mol%, based on the total amount of the structural units represented by the general formula (A), the general formula (B), and the general formula (C) being 100 mol%.

[0024] Within the range not impairing the effects of the invention, among the structural units of the polycarbonate resin of the present invention, in addition to the structural units represented by the general formula (A), the general formula (B), and the general formula (C), other structural units may also be included, preferably including 15 mol% or less, more preferably 10 mol% or less, and further preferably 5 mol% or less of other structural units.

[0025] There is no particular limitation on the form in which the structural units represented by the general formula (A), the general formula (B), and the general formula (C) of the present invention are contained in the resin. For example, in the present invention, the polycarbonate resin may contain a copolymer containing the structural units represented by the general formula (A), the general formula (B), and the general formula (C), or may be a binary or ternary resin composition containing homopolymers composed of each structural unit; or may also be a blend obtained by blending homopolymers containing the structural units represented by the general formula (A), (B), and (C). The polycarbonate resin of the present invention may include any structure of random, block, and alternating copolymer structures.

[0026] The weight-average molecular weight (Mw) of the polycarbonate resin of the present invention is 10,000 to 300,000, preferably 30,000 to 150,000; when Mw is less than 10,000, the molded body becomes brittle and is not preferred. When Mw is greater than 300,000, the melt viscosity increases, resulting in poor fluidity and difficulty in injection molding in the molten state, so it is also not preferred.

[0027] By copolymerizing a diol monomer with an ester bond with other fluorene-based and naphthalene-based monomers, the present invention can, while ensuring excellent optical properties of the obtained polycarbonate resin, improve the transmittance at low wavelengths (450 nm to 550 nm), so that the transmittance is ≥85% in the wavelength range of 450 to 1100 nm, and can make the b value lower and improve the color. The b value of a 1 mm sample plate injection-molded from the polycarbonate resin is less than 3, and the preferred value can be less than 1. The refractive index of an optical lens injection-molded at 23°C and a wavelength of 589 nm is 1.60 to 1.70, and the Abbe value is less than 25.

[0028] In the polycarbonate resin of the present invention, additives such as antioxidants, mold release agents, ultraviolet absorbers, plasticizers, crystal nucleating agents, reinforcing agents, dyes, antistatic agents, or antibacterial agents may be added.

[0029] The present invention also provides a method for preparing the polycarbonate resin, which can be obtained by reacting a dihydroxy compound having the structure shown in formula (1), and optionally a dihydroxy compound having the structures shown in formula (2) and formula (3) with a carbonic acid diester.

[0030] Preferably, the polycarbonate resin is prepared by reacting the dihydroxy compound shown in formula (1), and optionally the dihydroxy compounds shown in formula (2) and formula (3) with a carbonic acid diester in the presence of a basic compound catalyst, a transesterification catalyst or a mixed catalyst composed of both of them, or under the condition of no catalyst, by melt transesterification polycondensation method.

[0031] In the preparation method of the invention, the structures of the dihydroxy compounds shown in formula (1) to (3) are as follows:

[0032]

[0033] In formula (1), Z represents a linear or branched alkylene group having 1 to 6 carbon atoms, an aromatic ring having 6 to 20 carbon atoms, an alicyclic ring having 3 to 20 carbon atoms, a heterocyclic ring such as furan, thiophene, pyrrole, thiazole, imidazole, pyridine, pyrazine, pyrimidine, pyridazine, indole, etc., preferably methyl, ethyl, phenyl, cyclopropyl, cyclohexyl, furan, more preferably methyl, ethyl, phenyl; X independently represents an alkylene group having 1 to 10 carbon atoms, preferably an alkylene group having 1 to 6 carbon atoms, more preferably methylene, ethylene, propylene, and further preferably ethylene.

[0034]

[0035] In formula (2), Z1 independently represents an aryl group having 6 to 24 carbon atoms, preferably phenyl, naphthyl, biphenyl, anthryl, phenanthryl; R1 to R4 independently represent a hydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, a cycloalkoxy group having 5 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms or an aryloxy group having 6 to 20 carbon atoms, preferably methyl, ethyl, phenyl, naphthyl, biphenyl; Y independently represents an alkylene group having 1 to 10 carbon atoms, preferably an alkylene group having 1 to 6 carbon atoms, more preferably methylene, ethylene, propylene; the value of m is independently 0 to 10, preferably 0 to 2; the value of n is independently 0 to 4, preferably 0 to 2.

[0036]

[0037] In formula (3), W represents an alkylene group having 1 to 10 carbon atoms, preferably an alkylene group having 1 to 3 carbon atoms; R5 to R8 each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, a cycloalkoxy group having 5 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aryloxy group having 6 to 20 carbon atoms, preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an aryl group having 6 to 12 carbon atoms; more preferably a hydrogen atom, a methyl group, an ethyl group, a propyl group, a phenyl group, a naphthyl group, or a biphenyl group.

[0038] Preferably, the dihydroxy compound represented by formula (1) is a derivative structure of the following dihydroxy compound:

[0039]

[0040] Preferably, the dihydroxy compound represented by formula (2) is a derivative structure of the following dihydroxy compound:

[0041]

[0042] Preferably, the dihydroxy compound represented by formula (3) is a derivative structure of the following dihydroxy compound:

[0043]

[0044] In the preparation method of the present invention, the carbonic acid diester is one or more of diphenyl carbonate, dimethylxylene carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, etc., preferably diphenyl carbonate.

[0045] In the preparation method of the present invention, the molar ratio of the carbonic acid diester to the total of the dihydroxy compounds represented by formula (1), optionally (2), and (3) added is 0.95 to 1.14:1, preferably 0.98 to 1.12:1.

[0046] In the preparation method of the present invention, the basic compound catalyst is one or several of sodium hydroxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, lithium bicarbonate, sodium bicarbonate, potassium bicarbonate, magnesium bicarbonate, calcium bicarbonate, strontium bicarbonate, barium bicarbonate, sodium carbonate, magnesium carbonate, calcium carbonate, strontium carbonate, barium carbonate, cesium carbonate, calcium chloride, potassium chloride, cesium chloride, strontium chloride, barium chloride, lanthanum acetylacetonate, cerium acetylacetonate, magnesium acetate, calcium acetate, strontium acetate, barium acetate, magnesium stearate, calcium stearate, calcium benzoate, magnesium phenyl phosphate, tetrabutyl titanate, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylbenzylammonium hydroxide, triethylamine, dimethylbenzylamine, triphenylamine, diethylamine, tetrabutylammonium borohydride, tetrabutylammonium borohydride, tetrabutyltetraphenylborate ammonium, and tetraphenyltetraphenylborate ammonium, preferably one or several of sodium hydroxide, sodium bicarbonate, and cesium carbonate.

[0047] In the preparation method of the present invention, the transesterification catalyst is one or more of stannous chloride, stannous acetate, cerium acetylacetonate, zirconium acetylacetonate, zirconium oxyacetate, tetrabutoxy zirconium, zinc acetate, zinc benzoate, zinc 2-ethylhexanoate, stannous chloride, stannous acetate, cerium acetylacetonate, zirconium acetylacetonate, zirconium oxyacetate, tetrabutoxy zirconium, etc., preferably one or more of stannous chloride, cerium acetylacetonate, and zinc acetate.

[0048] In the preparation method of the present invention, the molar ratio of the total amount of the added basic compound catalyst and / or transesterification catalyst to the total amount of the dihydroxy compounds shown in formula (1), formula (2), and formula (3) is 1×10 -7 ~1×10 -2 :1, preferably 1×10 -6 ~1×10 -3 :1.

[0049] In some preferred embodiments of the present invention, the preparation method of the polycarbonate includes adding the dihydroxy compounds shown in formula (1) and optionally formula (2) and formula (3), a carbonic acid diester, a catalyst, and optionally an auxiliary agent into a reactor, replacing the air in the reactor with nitrogen 3 to 5 times, and then heating up to melt the materials in the reactor. The melting temperature is 160 to 210°C, preferably 180 to 200°C. The residence time at this stage is 30 to 90 minutes, preferably 40 to 60 minutes. The pressure is 50 kPa to 200 kPa under a nitrogen atmosphere, preferably 90 to 110 kPa. After the materials are melted, start stirring and heat up to the transesterification reaction temperature. The transesterification reaction temperature is 190 to 260°C, preferably 200 to 240°C. Control the pressure to be 0.5 to 50 kPa, preferably 1 to 30 kPa. The residence time at this stage is 60 to 320 minutes, preferably 120 to 240 minutes. Then continue to reduce the pressure and increase the temperature to start the polycondensation reaction. The system pressure at this stage is 10 to 500 Pa, preferably 50 to 100 Pa. The reaction temperature at this stage is 240 to 320°C, preferably 260 to 300°C. The residence time at this stage is 10 to 120 minutes, preferably 20 to 60 minutes. During the reaction, the generated small molecule compounds are immediately removed by distillation, and the polycarbonate resin is finally obtained in the reactor.

[0050] The application of the polycarbonate resin of the present invention in the field of optical devices is particularly suitable for preparing optical lenses, such as in the fields of mobile phone lenses, security lenses, vehicle-mounted lenses, etc.

[0051] The polycarbonate resin of the present invention has a high refractive index, a low Abbe number, good light transmittance, and a low b value, and is suitable for fields such as mobile phone lenses, vehicle-mounted lenses, and outdoor security lenses. The optical lens using the polycarbonate resin of the present invention has a low b value, good appearance, and clear imaging, and has broad application prospects. DETAILED DESCRIPTION

[0052] The present invention is now described as follows in conjunction with specific embodiments. It should be noted that the embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Any non-substantial improvements and adjustments made to the embodiments according to the content of the present invention are protected by the present invention.

[0053] Main raw material sources:

[0054] A-1 Aladdin Biotechnology Co., Ltd.

[0055] B-1, C-1: Sino Lixing Fine Chemical Co., Ltd.;

[0056] DPC: diphenyl carbonate, Sichuan Zhonglan Guosu Material Technology Co., Ltd.;

[0057] Unless otherwise specified, all other raw materials are commercially available.

[0058] Performance testing method:

[0059] 1) Weight average molecular weight (Mw): Gel permeation chromatography (GPC) was used with dichloromethane as the developing solvent and a calibration curve was prepared using standard polystyrenes of known molecular weight (molecular weight distribution = 1). Based on this calibration curve, Mw was calculated from the retention time of GPC.

[0060] 2) Light transmittance: The light transmittance was measured by the method of JIS-K-7361-1 using a turbidity meter for a film having a thickness of 0.1 mm made of the polycarbonate resin produced in the examples.

[0061] 3) Refractive index (nD): For a 1 mm thick film composed of the polycarbonate resin prepared in the example, the refractive index (nD) of the polycarbonate resin of the present invention at 23°C and a wavelength of 589 nm was measured using an Abbe refractometer according to the method of JIS-K-7142.

[0062] 4) Abbe number: The refractive index of a 0.1 mm thick film made of the polycarbonate resin produced in the example at wavelengths of 486 nm, 589 nm and 656 nm at 23° C. was measured using an Abbe refractometer, and the Abbe number ν was calculated using the following formula: ν=(nD-1) / (nF-nC).

[0063] 5) b value: After the obtained polycarbonate resin was vacuum dried at 120°C for 4 hours, it was injection molded using an injection molding machine at a barrel temperature of 270°C and a mold temperature of Tg-10°C to obtain a disc-shaped test sheet with a diameter of 50 mm and a thickness of 1 mm. The b value was measured using this sheet in accordance with JIS K7105.

[0064] Example 1

[0065] Put 2.54 g (0.01 mol) of A-1, 53.1 g (0.09 mol) of B-1, 23.56 g (0.11 mol) of diphenyl carbonate, 0.52 mg (2×10 -6 mol) of tin chloride, and 0.25 mg (3×10 -6 mol) of sodium bicarbonate into a 250 ml four-necked flask equipped with a stirrer and a distillation device. Replace the air with nitrogen 4 times. Heat it to 200 °C under a nitrogen atmosphere of 101 kPa and maintain this temperature for 60 min. After confirming that the raw materials are completely dissolved, start stirring, adjust the pressure to 20 kPa (A), and at the same time, raise the temperature to 240 °C at a rate of 10 °C / hr. At this time, confirm that phenol generated as a by-product starts to distill out. Maintain the reaction at 240 °C for 180 min, then raise the temperature to 280 °C at a rate of 20 °C / hr. After the temperature reaches 280 °C, gradually reduce the pressure to 100 Pa (A) within 120 min, and stir and react under this condition for 60 min to end the reaction. After the reaction is over, fill the four-necked flask with nitrogen to restore to normal pressure, take out the generated polycarbonate resin, and conduct performance evaluation. The physical property parameters of the obtained polycarbonate are shown in Table 1.

[0066] Example 2

[0067] Put 2.54 g (0.01 mol) of A-1, 33.66 g (0.09 mol) of C-1, 23.56 g (0.11 mol) of diphenyl carbonate, 0.52 mg (2×10 -6 mol) of tin chloride, and 0.25 mg (3×10 -6 mol) of sodium bicarbonate into a 250 ml four-necked flask equipped with a stirrer and a distillation device. Except for this, perform the same operations as in Example 1. The physical property parameters of the obtained polycarbonate are shown in Table 1.

[0068] Example 3

[0069] Put 0.25 g (0.001 mol) of A-1, 28.91 g (0.049 mol) of B-1, 18.7 g (0.05 mol) of C-1, 23.56 g (0.11 mol) of diphenyl carbonate, 0.52 mg (2×10 -6 mol) of tin chloride, and 0.25 mg (3×10 -6 mol) of sodium bicarbonate into a 250 ml four-necked flask equipped with a stirrer and a distillation device. Except for this, perform the same operations as in Example 1. The physical property parameters of the obtained polycarbonate are shown in Table 1.

[0070] Example 4

[0071] 7.62 g (0.03 mol) of A-1, 23.6 g (0.04 mol) of B-1, 11.2 g (0.03 mol) of C-1, 23.56 g (0.11 mol) of diphenyl carbonate, 0.52 mg (2×10 -6 mol) of tin chloride, and 0.25 mg (3×10 -6 mol) of sodium bicarbonate were placed in a 250 ml four-necked flask equipped with a stirrer and a distillation apparatus. Otherwise, the same operations as in Example 1 were carried out, and the physical property parameters of the obtained polycarbonate are shown in Table 1.

[0072] Example 5

[0073] 2.54 g (0.01 mol) of A-1, 23.6 g (0.04 mol) of B-1, 18.7 g (0.05 mol) of C-1, 23.56 g (0.11 mol) of diphenyl carbonate, 0.52 mg (2×10 -6 mol) of tin chloride, and 0.25 mg (3×10 -6 mol) of sodium bicarbonate were placed in a 250 ml four-necked flask equipped with a stirrer and a distillation apparatus. Otherwise, the same operations as in Example 1 were carried out, and the physical property parameters of the obtained polycarbonate are shown in Table 1.

[0074] Comparative Example 1

[0075] 29.5 g (0.05 mol) of B-1, 18.7 g (0.05 mol) of C-1, 23.56 g (0.11 mol) of diphenyl carbonate, 0.52 mg (2×10 -6 mol) of tin chloride, and 0.25 mg (3×10 -6 mol) of sodium bicarbonate were placed in a 250 ml four-necked flask equipped with a stirrer and a distillation apparatus. Otherwise, the same operations as in Example 1 were carried out, and the physical property parameters of the obtained polycarbonate are shown in Table 1.

[0076] Comparative Example 2

[0077] 40.65 (0.1 mol) of BPEF, 23.56 g (0.11 mol) of diphenyl carbonate, 0.88 mg (2×10 -6 mol) of cerium acetylacetonate, and 0.06 mg (1.5×10 -6 mol) of sodium hydroxide were placed in a 250 ml four-necked flask equipped with a stirrer and a distillation apparatus. Otherwise, the same operations as in Example 1 were carried out, and the physical property parameters of the obtained polycarbonate are shown in Table 1.

[0078]

[0079] Table 1

[0080]

[0081] Note: The lowest transmittance of the polycarbonate resin in the wavelength range of 450 nm - 1100 nm is at 450 nm. Therefore, it can be considered that the transmittance in the above wavelength range is greater than or equal to the transmittance value at 450 nm.

Claims

1. A high refractive index polycarbonate resin, which simultaneously contains structural units represented by general formula (A), general formula (B), and general formula (C). In general formula (A), Z represents an aromatic ring with 6 - 20 carbon atoms; X each independently represents an alkylene group with 1 - 10 carbon atoms. In general formula (B), Z1 each independently represents an aryl group with 6 - 24 carbon atoms; R1 - R4 each independently represent a hydrogen atom, a halogen atom, a cyano group, an alkyl group with 1 - 20 carbon atoms, an alkoxy group with 1 - 20 carbon atoms, a cycloalkyl group with 5 - 20 carbon atoms, a cycloalkoxy group with 5 - 20 carbon atoms, an aryl group with 6 - 20 carbon atoms, or an aryloxy group with 6 - 20 carbon atoms; Y each independently represents an alkylene group with 1 - 10 carbon atoms; the value of m is each independently 0 - 10; the value of n is each independently 0 - 4. In general formula (C), W represents an alkylene group with 1 - 10 carbon atoms; R5 - R8 each independently represent a hydrogen atom, an alkyl group with 1 - 20 carbon atoms, an alkoxy group with 1 - 20 carbon atoms, a cycloalkyl group with 5 - 20 carbon atoms, a cycloalkoxy group with 5 - 20 carbon atoms, an aryl group with 6 - 20 carbon atoms, or an aryloxy group with 6 - 20 carbon atoms.

2. The polycarbonate resin according to claim 1, characterized in that, In general formula (A), Z represents a phenyl group; X each independently represents an alkylene group with 1 - 6 carbon atoms; in general formula (B), Z1 each independently represents a phenyl group, a naphthyl group, a biphenyl group, an anthracenyl group, a phenanthryl group; R1 - R4 each independently represent a methyl group, an ethyl group, a phenyl group, a naphthyl group, a biphenyl group; Y each independently represents an alkylene group with 1 - 6 carbon atoms; the value of m is each independently 0 - 2; the value of n is each independently 0 - 2; in general formula (C), W represents an alkylene group with 1 - 3 carbon atoms; R5 - R8 each independently represent a hydrogen atom, a methyl group, an ethyl group, a phenyl group, a naphthyl group, a biphenyl group.

3. The polycarbonate resin according to claim 2, wherein In general formula (A), X each independently represents a methylene group, an ethylene group, a propylene group; in general formula (B), Y each independently represents a methylene group, an ethylene group, a propylene group.

4. The polycarbonate resin according to claim 1, wherein In the polycarbonate resin, The proportion of the structural unit represented by general formula (A) is 0.1 - 50 mol%; The proportion of the structural unit represented by general formula (B) is 0.1 - 99.8 mol%; The proportion of the structural unit represented by general formula (C) is 0.1 - 99.8 mol%; Based on the total amount of the structural units represented by general formula (A), general formula (B), and general formula (C) being 100 mol%.

5. The polycarbonate resin according to claim 1, wherein In the polycarbonate resin, The proportion of the structural unit represented by general formula (A) is 1 - 30 mol%; The proportion of the structural unit represented by general formula (B) is 20 - 60 mol%; The proportion of the structural unit represented by general formula (C) is 30 - 70 mol%; based on the total amount of the structural units represented by general formula (A), general formula (B), and general formula (C) being 100 mol%.

6. The polycarbonate resin according to claim 1, wherein The refractive index at 23°C and a wavelength of 589 nm is 1.60 - 1.70, the Abbe number is less than 25, the b value of a 1 mm sample is less than 3; and the light transmittance of its injection - molded lens in the wavelength range of 450 - 1100 nm is ≥85%.

7. A method for preparing the polycarbonate resin according to any one of claims 1-6, which can be prepared by reacting a dihydroxy compound having the structure shown in formula (1), a dihydroxy compound having the structure shown in formula (2), and a dihydroxy compound having the structure shown in formula (3) with a carbonic acid diester. The structures of the dihydroxy compounds shown in formula (1)-(3) are as follows: In formula (1), Z represents an aromatic ring having 6-20 carbon atoms; X independently represents an alkylene group having 1-10 carbon atoms; In formula (2), Z1 independently represents an aryl group having 6-24 carbon atoms; R1-R4 independently represent a hydrogen atom, a halogen atom, a cyano group, an alkyl group having 1-20 carbon atoms, an alkoxy group having 1-20 carbon atoms, a cycloalkyl group having 5-20 carbon atoms, a cycloalkoxy group having 5-20 carbon atoms, an aryl group having 6-20 carbon atoms or an aryloxy group having 6-20 carbon atoms; Y independently represents an alkylene group having 1-10 carbon atoms; the value of m is independently 0-10; the value of n is independently 0-4; In formula (3), W represents an alkylene group having 1-10 carbon atoms; R5-R8 independently represent a hydrogen atom, an alkyl group having 1-20 carbon atoms, an alkoxy group having 1-20 carbon atoms, a cycloalkyl group having 5-20 carbon atoms, a cycloalkoxy group having 5-20 carbon atoms, an aryl group having 6-20 carbon atoms or an aryloxy group having 6-20 carbon atoms.

8. The method according to claim 7, wherein In formula (1), Z represents a phenyl group; X independently represents an alkylene group having 1-6 carbon atoms; in formula (2), Z1 independently represents a phenyl group, a naphthyl group, a biphenyl group, an anthracenyl group, a phenanthryl group; R1-R4 independently represent a methyl group, an ethyl group, a phenyl group, a naphthyl group, a biphenyl group; Y independently represents an alkylene group having 1-6 carbon atoms; the value of m is independently 0-2; the value of n is independently 0-2; in formula (3), W represents an alkylene group having 1-3 carbon atoms; R5-R8 independently represent a hydrogen atom, a methyl group, an ethyl group, a phenyl group, a naphthyl group, a biphenyl group.

9. The method according to claim 8, wherein In formula (1), X independently represents a methylene group, an ethylene group, a propylene group; in formula (2), Y independently represents a methylene group, an ethylene group, a propylene group.

10. According to the method of claim 7, wherein The structural formula of formula (1) is: The structural formula of formula (2) is: The structural formula of formula (3) is as follows:

11. The method according to claim 7, wherein the carbonic acid diester is one or more of diphenyl carbonate, dimethylxylene carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate.

12. The method according to claim 7, wherein The molar ratio of the carbonic acid diester to the total amount of the dihydroxy compounds shown in formula (1), (2), and (3) added is 0.95-1.14:

1.

13. The method according to claim 7, wherein The molar ratio of the carbonic acid diester to the total amount of the dihydroxy compounds shown in formula (1), (2), and (3) added is 0.98-1.12:

1.

14. Application of the polycarbonate resin according to any one of claims 1-6 or the polycarbonate resin prepared by the method according to any one of claims 7-13 in the field of optical devices.

15. The application according to claim 14, characterized in that, Suitable for preparing optical lenses and optical films.

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